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Find video protocols related to scientific articles indexed in Pubmed.
S-allyl cysteine activates the Nrf2-dependent antioxidant response and protects neurons against ischemic injury in vitro and in vivo.
J. Neurochem.
PUBLISHED: 11-14-2014
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Stroke is a devastating clinical condition for which an effective neuroprotective treatment is currently unavailable. S-allyl cysteine (SAC), the most abundant organosulfur compound in aged garlic extract, has been reported to possess neuroprotective effects against stroke. However, the mechanisms underlying its beneficial effects remain poorly defined. The present study tests the hypothesis that SAC attenuates ischemic neuronal injury by activating the nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent antioxidant response in both in vitro and in vivo models. Our findings demonstrate that SAC treatment resulted in an increase in Nrf2 protein levels and subsequent activation of antioxidant response element (ARE) pathway genes in primary cultured neurons and mice. Exposure of primary neurons to SAC provided protection against oxygen and glucose deprivation (OGD)-induced oxidative insults. In wild type (Nrf2(+/+) ) mice, systemic administration of SAC attenuated middle cerebral artery occlusion (MCAO)-induced ischemic damage, a protective effect not observed in Nrf2 knockout (Nrf2(-/-) ) mice. Taken together, these findings provide the first evidence that activation of the Nrf2 antioxidant response by SAC is strongly associated with its neuroprotective effects against experimental stroke and suggest that targeting the Nrf2 pathway may provide therapeutic benefit for the treatment of stroke. This article is protected by copyright. All rights reserved.
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Expression profiles of glyceraldehyde-3-phosphate dehydrogenase from Clonorchis sinensis: a glycolytic enzyme with plasminogen binding capacity.
Parasitol. Res.
PUBLISHED: 08-28-2014
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Globally, 15-20 million people are infected with Clonorchis sinensis (C. sinensis) which results in clonorchiasis. In China, clonorchiasis is considered to be one of the fastest-growing food-borne parasitic diseases. That more key molecules of C. sinensis are characterized will be helpful to understand biology and pathogenesis of the carcinogenic liver fluke. Glyceraldehyde-3-phosphate dehydrogenases (GAPDHs) from many species have functions other than their catalytic role in glycolysis. In the present study, we analyzed the sequence and structure of GAPDH from C. sinensis (CsGAPDH) by using bioinformatics tools and obtained its recombinant protein by prokaryotic expression system, to learn its expression profiles and molecular property. CsGAPDH could bind to human intrahepatic biliary epithelial cell in vivo and in vitro by the method of immunofluorescence assays. CsGAPDH also disturbed in lumen of biliary tract near to the parasite in the liver of infected rat. Western blotting analysis together with immunofluorescence assay indicated that CsGAPDH was a component of excretory/secretory proteins (CsESPs) and a surface-localized protein of C. sinensis. Quantitative real-time PCR (Q-PCR) and Western blotting demonstrated that CsGAPDHs are expressed at the life stages of adult worm, metacercaria, and egg, but the expression levels were different from each other. Recombinant CsGAPDH (rCsGAPDH) was confirmed to have the capacity to catalyze the conversion of glyceraldehyde 3-phosphate to D-glycerate 1,3-bisphosphate which was inhibited by AMP in a dose-dependent manner. In addition, rCsGAPDH was able to interact with human plasminogen in a dose-dependent manner by ELISA. The interaction could be inhibited by lysine. The plasminogen binding capacity of rCsGAPDH along with the distribution of CsGAPDH in vivo and in the liver of C. sinensis-infected rat hinted that surface-localized CsGAPDH might play an important role in host invasion of the worm besides its glycolytic activity. Our work will be a cornerstone for getting more messages about CsGAPDH and its role in biology and parasitism of C. sinensis.
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Identification, immunolocalization, and characterization analyses of an exopeptidase of papain superfamily, (cathepsin C) from Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 08-21-2014
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Cathepsin C is an important exopeptidase of papain superfamily and plays a number of great important roles during the parasitic life cycle. The amino acid sequence of cathepsin C from Clonorchis sinensis (C. sinensis) showed 54, 53, and 49% identities to that of Schistosoma japonicum, Schistosoma mansoni, and Homo sapiens, respectively. Phylogenetic analysis utilizing the sequences of papain superfamily of C. sinensis demonstrated that cathepsin C and cathepsin Bs came from a common ancestry. Cathepsin C of C. sinensis (Cscathepsin C) was identified as an excretory/secretory product by Western blot analysis. The results of transcriptional level and translational level of Cscathepsin C at metacercaria stage were higher than that at adult worms. Immunolocalization analysis indicated that Cscathepsin C was specifically distributed in the suckers (oral sucker and ventral sucker), eggs, vitellarium, intestines, and testis of adult worms. In the metacercaria, it was mainly detected on the cyst wall and excretory bladder. Combining with the results mentioned above, it implies that Cscathepsin C may be an essential proteolytic enzyme for proteins digestion of hosts, nutrition assimilation, and immune invasion of C. sinensis. Furthermore, it may be a potential diagnostic antigen and drug target against C. sinensis infection.
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Synergetic effect of Zn substitution on the electron and phonon transport in Mg2Si0.5Sn0.5-based thermoelectric materials.
Dalton Trans
PUBLISHED: 08-14-2014
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Mg2Si1-xSnx alloys are a prospective material for thermoelectric generators at moderate temperatures. The thermoelectric properties of Mg2Si0.5Sn0.5-based thermoelectric materials with only Zn substitution or Zn/Sb co-doping were investigated. Isoelectronic Zn substitution did not affect the carrier concentration, but improved the carrier mobility. Zn atoms incorporated into a Sb-doped Mg2Si0.5Sn0.5 matrix simultaneously boosted the power factor and suppressed the lattice thermal conductivity, leading to an enhancement of the thermoelectric figure of merit ZT of the resulting bulk materials. The interplay between the electron and phonon transport of Mg2Si0.5Sn0.49Sb0.01 substituted with Zn at Mg sites results in an enhancement of the ZT by 25% at ?730 K, from ZT? 0.8 in Mg2Si0.5Sn0.49Sb0.01 to ZT? 1.0 in Mg1.98Zn0.02Si0.5Sn0.49Sb0.01. Solid solutions in the Mg2Si-Mg2Sn system appear to be more promising for thermoelectric applications.
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Autophagy inhibition sensitizes hepatocellular carcinoma to the multikinase inhibitor linifanib.
Sci Rep
PUBLISHED: 07-07-2014
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Autophagy is a critical survival pathway for cancer cells under conditions of stress. Thus, induction of autophagy has emerged as a drug resistance mechanism. This study is to determine whether autophagy is activated by a novel multikinase inhibitor linifanib, thereby impairing the sensitivity of hepatocellular carcinoma (HCC) cells to this targeted therapy. Here, we found that linifanib induced a high level of autophagy in HCC cells, which was accompanied by suppression of phosphorylation of PDGFR-? and its downstream Akt/mTOR and Mek/Erk signaling pathways. Cell death induced by linifanib was greatly enhanced after autophagy inhibition by the pharmacological inhibitors or siRNAs against autophagy related genes, ATG5 and ATG7, in vitro. Moreover, HCQ, an FDA-approved drug used to inhibit autophagy, could significantly augment the anti-HCC effect of linifanib in a mouse xenograft model. In conclusion, linifanib can induce cytoprotective autophagy by suppression of PDGFR-? activities in HCC cells. Thus, autophagy inhibition represents a promising approach to improve the efficacy of linifanib in the treatment of HCC patients.
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Interaction of autophagy with microRNAs and their potential therapeutic implications in human cancers.
Cancer Lett.
PUBLISHED: 06-27-2014
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Autophagy is a tightly regulated intracellular self-digestive process involving the lysosomal degradation of cytoplasmic organelles and proteins. A number of studies have shown that autophagy is dysregulated in cancer initiation and progression, or cancer cells under various stress conditions. As a catabolic pathway conserved among eukaryotes, autophagy is regulated by the autophagy related genes and pathways. MicroRNAs (miRNAs) are small, non-coding endogenous RNAs that may regulate almost every cellular process including autophagy. And autophagy is also involved in the regulation of miRNAs expression and homeostasis. Here we reviewed some literatures on the interaction of miRNAs with autophagy and the application of miRNAs-mediated autophagic networks as a promising target in pre-clinical cancer models. Furthermore, strategies of miRNAs delivery for miRNAs-based anti-cancer therapy will also be summarized and discussed.
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The intrinsic disorder related alloy scattering in ZrNiSn half-Heusler thermoelectric materials.
Sci Rep
PUBLISHED: 06-23-2014
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The intrinsic structural disorder dramatically affects the thermal and electronic transport in semiconductors. Although normally considered an ordered compound, the half-Heusler ZrNiSn displays many transport characteristics of a disordered alloy. Similar to the (Zr,Hf)NiSn based solid solutions, the unsubstituted ZrNiSn compound also exhibits charge transport dominated by alloy scattering, as demonstrated in this work. The unexpected charge transport, even in ZrNiSn which is normally considered fully ordered, can be explained by the Ni partially filling interstitial sites in this half-Heusler system. The influence of the disordering and defects in crystal structure on the electron transport process has also been quantitatively analyzed in ZrNiSn1-xSbx with carrier concentration nH ranging from 5.0×10(19) to 2.3×10(21)?cm(-3) by changing Sb dopant content. The optimized carrier concentration nH ? 3-4×10(20)?cm(-2) results in ZT ? 0.8 at 875K. This work suggests that MNiSn (M = Hf, Zr, Ti) and perhaps most other half-Heusler thermoelectric materials should be considered highly disordered especially when trying to understand the electronic and phonon structure and transport features.
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Constitutively active chemokine CXC receptors.
Adv. Pharmacol.
PUBLISHED: 06-17-2014
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Chemokines are low-molecular-weight, secreted proteins that act as leukocyte-specific chemoattractants. The chemokine family has more than 40 members. Based on the position of two conserved cysteines in the N-terminal domain, chemokines can be divided into the CXC, C, CC, and CX3C subfamilies. The interaction of chemokines with their receptors mediates signaling pathways that play critical roles in cell migration, differentiation, and proliferation. The receptors for chemokines are G protein-coupled receptors (GPCRs), and thus far, seven CXC receptors have been cloned and are designated CXCR1-7. Constitutively active GPCRs are present in several human immune-mediated diseases and in tumors, and they have provided valuable information in understanding the molecular mechanism of GPCR activation. Several constitutively active CXC chemokine receptors include the V6.40A and V6.40N mutants of CXCR1; the D3.49V variant of CXCR2; the N3.35A, N3.35S, and T2.56P mutants of CXCR3; the N3.35 mutation of CXCR4; and the naturally occurring KSHV-GPCR. Here, we review the regulation of CXC chemokine receptor signaling, with a particular focus on the constitutive activation of these receptors and the implications in physiological conditions and in pathogenesis. Understanding the mechanisms behind the constitutive activation of CXC chemokine receptors may aid in pharmaceutical design and the screening of inverse agonists and allosteric modulators for the treatment of autoimmune diseases and cancers.
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Lovastatin inhibited the growth of gastric cancer cells.
Hepatogastroenterology
PUBLISHED: 06-05-2014
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Gastric cancer cells required large amount of cholesterol to grow and proliferate. The objective of this study was to examine whether the growth of gastric cancer cells was inhibited in vivo by using lovastatin, an effective cholesterol-lowing drug.
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Cardiac structure and function improvements in coronary artery disease combined with severe obstructive sleep apnea/hypopnea syndrome patients via noninvasive positive pressure ventilation therapy.
Coron. Artery Dis.
PUBLISHED: 05-30-2014
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The aim of this study was to investigate the effects of a noninvasive positive pressure ventilation therapy on cardiac structure and function in patients with coronary heart disease combined with obstructive sleep apnea/hypopnea syndrome (OSAHS).
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Warfarin compared with aspirin for older Chinese patients with stable coronary heart diseases and atrial fibrillation complications.
Int J Clin Pharmacol Ther
PUBLISHED: 05-20-2014
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To compare the therapeutic warfarin and aspirin efficacies for treatments of atrial fibrillation (AF) complicated with stable coronary heart disease particularly in older Chinese patients.
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Comparison of two serpins of Clonorchis sinensis by bioinformatics, expression, and localization in metacercaria.
Pathog Glob Health
PUBLISHED: 05-16-2014
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Clonorchiasis, which has been an important public health problem in China, is caused by ingestion of raw or undercooked fish contaminated by live metacercaria. Therefore, preventing fish from infecting is of great significance for controlling the disease. SERPINs (serine protease inhibitors) are well known as negative regulators of hemostasis, thrombolysis, and innate immune responses. In the present study, two full-length sequences encoding SERPIN were identified from metacercaria cDNA library of Clonorchis sinensis (C. sinensis) and were denominated as CsSERPIN and CsSERPIN3, respectively. Bioinformatics analysis showed that the two sequences shares 35.9% identity to each other. Both of the sequences have SERPIN domain and the greatest difference between the two domains is the reactive centre loop. Transmembrane region was found in CsSERPIN3 while not in CsSERPIN. The expression of the two CsSERPINs was significantly higher at the life stage of metacercaria than that of adult. The transcription levels of CsSERPIN and CsSERPIN3 at metacercaria stage were 3.249- and 11.314-fold of that at adult stage, respectively. Furthermore, the expression of CsSERPIN was 4.32-fold of that of CsSERPIN3 at metacercaria stage. Immunobiochemistry revealed that CsERPIN was dispersed at subtegument and oral sucker of metacercaria, while CsSERPIN3 localized intensely in the tegument of metacercaria of C. sinensis inside of the cyst wall. All these indicated that the CsSERPINs play important roles at metacercaria stage of the parasite. CsSERPIN may take part in regulation of endogenous serine proteinase and CsSERPIN3 may be involved in immune evasion and be a potential candidate for vaccine and drug target for clonorchiasis.
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Therapeutic effects of induced pluripotent stem cells in chimeric mice with ?-thalassemia.
Haematologica
PUBLISHED: 05-09-2014
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Although ?-thalassemia is one of the most common human genetic diseases, there is still no effective treatment other than bone marrow transplantation. Induced pluripotent stem cells have been considered good candidates for the future repair or replacement of malfunctioning organs. As a basis for developing transgenic induced pluripotent stem cell therapies for thalassemia, ?(654) induced pluripotent stem cells from a ?(654) -thalassemia mouse transduced with the normal human ?-globin gene, and the induced pluripotent stem cells with an erythroid-expressing reporter GFP were used to produce chimeric mice. Using these chimera models, we investigated changes in various pathological indices including hematologic parameters and tissue pathology. Our data showed that when the chimerism of ?(654) induced pluripotent stem cells with the normal human ?-globin gene in ?(654) mice is over 30%, the pathology of anemia appeared to be reversed, while chimerism ranging from 8% to 16% provided little improvement in the typical ?-thalassemia phenotype. Effective alleviation of thalassemia-related phenotypes was observed when chimerism with the induced pluripotent stem cells owning the erythroid-expressing reporter GFP in ?(654) mouse was greater than 10%. Thus, 10% or more expression of the exogenous normal ?-globin gene reduces the degree of anemia in our ?-thalassemia mouse model, whereas treatment with ?(654) induced pluripotent stem cells which had the normal human ?-globin gene had stable therapeutic effects but in a more dose-dependent manner.
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Characterization of the secreted cathepsin B cysteine proteases family of the carcinogenic liver fluke Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 05-02-2014
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Clonorchis sinensis excretory/secretory products (ESP) have gained high attentions because of their potential to be vaccine candidates and drug targets in C. sinensis prevention. In this study, we extensively profiled the characteristics of four C. sinensis cathepsin B cysteine proteases (CsCB1, CsCB2, CsCB3, and CsCB4). Bioinformatics analysis showed all CsCBs contained signal peptides at the N-terminal. Functional domains and residues were found in CsCB sequences. We expressed four CsCBs and profiled immune responses followed by vaccine trials. Recombinant CsCBs could induce high IgG titers, indicating high immunogenicity of CsCB family. Additionally, ELISA results showed that both IgG1 and IgG2a levels apparently increased post-immunization with all four CsCBs, showing that combined Th1/Th2 immune responses were triggered by CsCB family. Both Real-time polymerase chain reaction (RT-PCR) and Western blotting confirmed that four CsCBs have distinct expression patterns in C. sinensis life stages. More importantly, we validated our hypothesis that CsCBs were C. sinensis excretory/secretory products. CsCBs could be recognized by C. sinensis-infected sera throughout the infection period, indicating that secreted CsCBs are immune triggers during C. sinensis infection. The protective effect was assessed by comparing the worm burden and egg per gram (EPG) between CsCB group and control group, showing that worm burden (P?
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Molecular and biochemical characterizations of three fructose-1,6-bisphosphate aldolases from Clonorchis sinensis.
Mol. Biochem. Parasitol.
PUBLISHED: 04-13-2014
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Fructose-1,6-bisphosphate aldolase (FbA) is a ubiquitous enzyme in glycolysis. In the present study, we screened out three distinct genes encoding FbA isozymes (CsFbAs, CsFbA-1/2/3) from Clonorchis sinensis (C. sinensis) and characterized their sequences and structures profiles as well as biochemical properties. The amino acid sequences of CsFbAs shared homology with those of Class I FbAs from other species. The putative quaternary structures revealed that CsFbA-2 and CsFbA-3 were tetramers, while CsFbA-1 was dimer. Recombinant CsFbA-2 and CsFbA-3 (rCsFbA-2/3) were confirmed to be Class I FbAs for their stable enzymatic activities in the presence of EDTA or metal ions. However, recombinant CsFbA-1 (rCsFbA-1) did not show the catalytic activity, which might be due to the inappropriate fold and interaction between its subunits. Both rCsFbA-2 and rCsFbA-3 showed similar enzymatic properties such as optimal temperatures and broad pH ranges that similar to human FbA isozymes. They showed relatively higher affinities for fructose-1,6-bisphosphate (FBP) than fructose-1-phosphate (F-1-P). Their kcat ratios of FBP to F-1-P were in accordance with those of human FbA-A or C. In addition, CsFbAs were differentially transcribed in the developmental stages of C. sinensis, suggesting their essential roles throughout the life stages. Extensive distribution of CsFbAs in adult worms indicated that ubiquitous activities of CsFbAs took place in these organs. Collectively, these results suggested that long-term parasitic environment might adapt these isozymes similar to host FbAs for metabolic requirement. Our study will provide new insight into CsFbAs in the glycometabolism of C. sinensis and relationship between the host and the parasite.
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Systemic and local mucosal immune responses induced by orally delivered Bacillus subtilis spore expressing leucine aminopeptidase 2 of Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 04-07-2014
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Human clonorchiasis caused by Clonorchis sinensis (C. sinensis) has been increasingly prevalent in recent years so that an effective measure is essential and urgent to control the infectious disease. Oral delivery of antigens from C. sinensis may be an important approach to effectively induce both systemic and local immune responses to anti-infection of the parasite. In the current study, we used Bacillus subtilis (B. subtilis) spores as a delivery vehicle to introduce leucine aminopeptidase 2 of C. sinensis (CsLAP2), an excretory/secretory antigen with high immunogenicity, expressing on their surface. SDS-PAGE, western blotting, and flow cytometry indicated that CsLAP2 was successfully expressed on the surface of B. subtilis spores (CotC-CsLAP2 spores). BALB/c mice were treated with spores intragastrically. On day 31 after the treatment, we found that mice intragastrically treated with CotC-CsLAP2 spores exhibited higher IgG, IgG1, IgG2a, and IgA level in sera as well as higher sIgA level in bile and intestinal lavage fluid compared to mice orally administrated with spores not expressing CsLAP2 (CotC spores) and naïve mice. The peak titer of IgG/IgA presented on day 31/49 after oral administration. IgG1 level was lower than IgG2a in group administrated with CotC-CsLAP2 spores. sIgA-secreting cells were obviously observed in intestinal epithelium of mice orally treated with CotC-CsLAP2 spores. After incubated with CotC-CsLAP2, the levels of IFN-?, IL-6, IL-10, IL-17A, and TNF significantly increased in the supernatant of splenocytes isolated from mice orally treated with CotC-CsLAP2 spores, while there was no statistically significant difference of IL-4 level representing Th2 response among the groups. Our study demonstrated that oral administration of CsLAP2 delivered by B. subtilis spore elicited obvious systemic and local mucosal immunity. Secretory IgA and Th1-Th17 cellular immunity might involved in mechanisms of the immune response.
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Proteomic identification of potential Clonorchis sinensis excretory/secretory products capable of binding and activating human hepatic stellate cells.
Parasitol. Res.
PUBLISHED: 03-28-2014
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Epidemiological and experimental evidence demonstrated that Clonorchis sinensis is an important risk factor of hepatic fibrosis and cholangiocarcinoma. C. sinensis excretory/secretory products (CsESPs) are protein complex including proteases, antioxidant enzymes, and metabolic enzymes, which may contribute to pathogenesis of liver fluke-associated hepatobiliary diseases. However, potential CsESP candidates involved into hepatic fibrosis and cholangiocarcinoma still remain to be elucidated. In the present study, we performed proteomic identification of CsESP candidates capable of binding and activating human hepatic stellate cell line LX-2. Immunofluorescence analysis confirmed the interaction of CsESPs with LX-2 cell membrane. LX-2 cells could be stimulated by CsESPs from 24 h post incubation (p?
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Preparation of uniform magnetic recoverable catalyst microspheres with hierarchically mesoporous structure by using porous polymer microsphere template.
Nanoscale Res Lett
PUBLISHED: 03-21-2014
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Merging nanoparticles with different functions into a single microsphere can exhibit profound impact on various applications. However, retaining the unique properties of each component after integration has proven to be a significant challenge. Our previous research demonstrated a facile method to incorporate magnetic nanoparticles into porous silica microspheres. Here, we report the fabrication of porous silica microspheres embedded with magnetic and gold nanoparticles as magnetic recoverable catalysts. The as-prepared multifunctional composite microspheres exhibit excellent magnetic and catalytic properties and a well-defined structure such as uniform size, high surface area, and large pore volume. As a result, the very little composite microspheres show high performance in catalytic reduction of 4-nitrophenol, special convenient magnetic separability, long life, and good reusability. The unique nanostructure makes the microspheres a novel stable and highly efficient catalyst system for various catalytic industry processes.
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Cotargeting EGFR and autophagy signaling: A novel therapeutic strategy for non-small-cell lung cancer.
Mol Clin Oncol
PUBLISHED: 03-21-2014
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Epidermal growth factor receptor (EGFR) somatic mutations are found in the majority of non-small-cell lung cancers (NSCLCs) and patients with NSCLC who harbor EGFR mutations have been shown to exhibit increased sensitivity to the small-molecule EGFR-tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib. However, the majority of tumors develop acquired resistance to EGFR-TKIs after a median of 10-16 months, which limits the clinical efficacy of these drugs. Autophagy, an important homeostatic cellular recycling mechanism, has emerged as a potential target for the acquired resistance phenotype. Recently, several studies demonstrated that autophagy may be induced in a dose-dependent manner by treatment of multiple cancer cell lines with EGFR-TKIs in vitro. Furthermore, it was recently reported that autophagy, as a cytoprotective response, may be activated by EGFR-TKIs in lung cancer cells and that the inhibition of autophagy enhanced the cytotoxic effect of EGFR-TKIs. In this review, we aimed to focus on the association between resistance to EGFR-TKIs and autophagy, and assess whether autophagy inhibition represents a promising approach to improve the efficacy of EGFR-TKIs in the treatment of NSCLC patients.
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Biochemical and immunological characterization of annexin B30 from Clonorchis sinensis excretory/secretory products.
Parasitol. Res.
PUBLISHED: 03-19-2014
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Clonorchis sinensis has been classified as group I biological carcinogen for cholangiocarcinoma by the World Health Organization. Biological studies on excretory/secretory products (ESPs) enabled us to understand the pathogenesis mechanism of C. sinensis and develop new strategies for the prevention of clonorchiasis. In this study, sequence analysis showed that annexin B30 from C. sinensis (CsANXB30) is composed of four annexin repeats which were characterized by type II and III Ca(2+)-binding sites or KGD motif with the capability of Ca(2+)-binding. In addition, immunoblot assay revealed that recombinant CsANXB30 (rCsANXB30) could be recognized by the sera from rats infected with C. sinensis and the sera from rats immunized by CsESPs. Real-time PCR showed that its transcriptional level was the highest at the stage of metacercaria. Immunofluorescence assay was employed to confirm that CsANXB30 was distributed in the tegument, intestine, and egg of adult worms, as well as the tegument and vitellarium of metacercaria. rCsANXB30 was able to bind phospholipid in a Ca(2+)-dependent manner and human plasminogen in a dose-dependent manner. Moreover, cytokine and antibody measurements indicated that rats subcutaneously immunized with rCsANXB30 developed a strong IL-10 production in spleen cells and a high level of IgG1 isotype, indicating that rCsANXB30 could trigger specific humoral and cellular immune response in rats. The present results implied that CsANXB30 might be involved in a host-parasite interaction and affected the immune response of the host during C. sinensis infection.
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Reduced graphene oxide-induced recrystallization of NiS nanorods to nanosheets and the improved Na-storage properties.
Inorg Chem
PUBLISHED: 03-19-2014
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Preparation of two-dimensional (2D) graphene-like materials is currently an emerging field in materials science since the discovery of single-atom-thick graphene prepared by mechanical cleavage. In this work, we proposed a new method to prepare 2D NiS, where reduced graphene oxide (rGO) was found to induce the recrystallization of NiS from nanorods to nanosheets in a hydrothermal process. The process and mechanism of recrystallization have been clarified by various characterization techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) mapping, and X-ray photoelectron spectroscopy (XPS). The characterization of ex situ NiS/rGO products by SEM and EDS mapping indicates that the recrystallization of NiS from nanorods to nanosheets is realized actually through an exfoliation process, while the characterization of in situ NiS/rGO products by SEM, TEM, and EDS mapping reveals the exfoliation process. The XPS result demonstrates that hydrothermally assisted chemical bonding occurs between NiS and rGO, which induces the exfoliation of NiS nanorods into nanosheets. The obtained NiS/rGO composite shows promising Na-storage properties.
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Noninvasive positive pressure ventilation therapy can improve cardiac structure and function in patients with coronary artery disease combined with severe obstructive sleep apnea/hypopnea syndrome.
Cardiol J
PUBLISHED: 02-28-2014
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To investigate the effects of a noninvasive positive pressure ventilation therapy on cardiac structure and function in patients with coronary heart disease combined with obstructive sleep apnea/hypopnea syndrome (OSAHS).
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Induction of protection against foot-and-mouth disease virus in cell culture and transgenic suckling mice by miRNA targeting integrin ?v receptor.
J. Biotechnol.
PUBLISHED: 02-24-2014
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Foot-and-mouth disease virus (FMDV) is an RNA virus that causes a highly contagious disease in domestic and wild cloven-hoofed animals. Although vaccination has been used to protect animals against FMDV, there are shortcomings in the efficacy of the available vaccines. RNA interference (RNAi) is triggered by small RNA molecules, including short interfering RNAs and microRNAs (miRNAs), and the use of RNAi-based methods have demonstrated promise as an alternative method of controlling the transmission of FMDV. However, the method of delivery, short duration of siRNA and miRNA in vivo, and the genetic variability of FMDV confound the use of RNAi-based strategies for FMDV control. FMDV has been shown to exploit host-cell integrins as cell-surface receptors to initiate infection. We selected the gene for the integrin ?v subunit as an RNAi target, and constructed three ?v-specific miRNA expression plasmids. The effects of these miRNAs on FMDV infection were examined in PK-15 cells and transgenic suckling mice. In PK-15 cells, the expression of the ?v-specific miRNAs significantly inhibited the expression of integrin ?v receptor and decreased FMDV infection. The transgenic mice were generated by integrating the ?v-specific miRNA expression cassette using pronuclear microinjection. When challenged with a dose of FMDV ten times greater than the LD50, the survival rate of transgenic suckling mice was approximately six-fold higher than that of their non-transgenic littermates, indicating that the interference of the miRNAs significantly reduced FMDV infection in the transgenic mice. This is the first report of limiting FMDV attachment to cellular receptors using miRNA-mediated gene knock down of cell-surface receptors to significantly reduce FMDV infection in cell culture and transgenic suckling mice.
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Molecular characterization of Clonorchis sinensis secretory myoglobin: delineating its role in anti-oxidative survival.
Parasit Vectors
PUBLISHED: 02-22-2014
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Clonorchiasis is a globally important, neglected food-borne disease caused by Clonorchis sinensis (C. sinensis), and it is highly related to cholangiocarcinoma and hepatocellular carcinoma. Increased molecular evidence has strongly suggested that the adult worm of C. sinensis continuously releases excretory-secretory proteins (ESPs), which play important roles in the parasite-host interactions, to establish successful infection and ensure its own survival. Myoglobin, a hemoprotein, is present in high concentrations in trematodes and ESPs. To further understand the biological function of CsMb and its putative roles in the interactions of C. sinensis with its host, we explored the molecular characterization of CsMb in this paper.
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Identification, immunolocalization, and immunological characterization of nitric oxide synthase-interacting protein from Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 02-14-2014
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Recently, accumulating evidences indicate that nitric oxide (NO) is a potent mediator with diverse roles in regulating cellular functions, signaling pathways, and variety of pathological processes. In the present study, using data from the published genomic for Clonorchis sinensis (C. sinensis), we investigated a gene encoding nitric oxide synthase-interacting protein (NOSIP) of C. sinensis. Recombinant CsNOSIP (rCsNOSIP) was expressed and purified from Escherichia coli BL21. The open reading frame of CsNOSIP comprises 867 bp which encodes 289 amino acids and shares 72.9, 45.2, 47, 46.4, and 45.8% identity with NOSIP from Schistosoma mansoni, Xenopus laevis, Rattus norvegicus, Mus musculus, and Homo sapiens, respectively. Bioinformatics analysis suggested that the full-length sequence contains an eNOS-interacting domain and numerous B-cell epitopes. Quantitative RT-PCR indicated that CsNOSIP differentially transcribed throughout the adult worms, metacercariae, and egg stages of C. sinensis, and were highly expressed in the adult worms. Moreover, western blot analysis showed that the rCsNOSIP could be detected by the serum from BALB/c mice infected with C. sinensis and the serum from BALB/c mice immunized with excretory/secretory products (ESPs). Furthermore, immunolocalization assay showed that CsNOSIP was specifically localized in the intestine, vitellarium, and eggs of adult worm. Both immunoblot and immunolocalization results demonstrated that CsNOSIP was one component of ESPs of C. sinensis, which could be supported by SignalP analysis. Moreover, analysis of the antibody subclass and cytokine profile demonstrated that subcutaneously immunized BALB/c mice with rCsNOSIP could significantly enhance serum IgG1 level and up-regulate expression of IL-4 and IL-6 in the splenocytes. Our results suggested that CsNOSIP was an important antigen exposed to host immune system and probably involved in immune regulation of host by inducing Th2-polarized immune response.
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Polarization properties of garnet and groove films on garnet in the transmission and reflection modes.
Opt Express
PUBLISHED: 02-12-2014
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Stokes polarimeters are most commonly used to measure the state of polarization of optical wave. Dependence of Stokes parameters, degree of polarization on external magnetic field are presented for garnet and groove films on garnet in the transmission and reflection modes. The Stokes parameters S1, S2, S3 of different modes show different tendency and asymmetrically change when the external magnetic field change, while the degree of polarization basically unchange.
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p53 suppresses stress-induced cellular senescence via regulation of autophagy under the deprivation of serum.
Mol Med Rep
PUBLISHED: 02-07-2014
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The tumor suppressor p53 is widely known for its ability to induce cell cycle arrest or cell death, therefore preventing neoplastic progression. Previous studies have demonstrated novel roles for p53 in the regulation of autophagy and senescence. p53 can not only exert cell cycle?arresting and senescence?promoting or suppressing functions, but can also induce autophagic ?ux, particularly under conditions of nutrient deprivation. The present study demonstrated that p53 was capable of activating autophagy, which permits cell survival under conditions of serum starvation, and suppresses cellular senescence through inhibition of the mammalian target of rapamycin pathway. These results suggest that active autophagy may be a potential mechanism by which p53 suppresses cellular senescence, in response to serum starvation. The findings of the present study provide a potential mechanism for suppression of senescence by p53.
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Molecular characterization and serological reactivity of a vacuolar ATP synthase subunit ?-like protein from Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 01-28-2014
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The vacuolar ATPase enzyme complex (V-ATPase) pumps protons across membranes, energized by hydrolysis of ATP. Extensive investigations on structural and biochemical features of these molecules have implied their importance in the physiological process. In this study, a full-length sequence encoding a vacuolar ATP synthase subunit ?-like protein of Clonorchis sinensis (CsATP-?) was isolated from our cDNA library. The hypothetical 226 amino acid sequence shared 76% identity with ATP-? proteins of Schistosoma japonicum and above 55% identity with ATP-? proteins from human and other eukaryotes. Characteristic Asp??? amino acid residues and seven B-cell epitopes were predicted in this sequence. The complete coding sequence of the gene was expressed in Escherichia coli. Recombinant CsATP-? (rCsATP-?) protein could be probed by anti-rCsATP-? rat serum and C.sinensis-infected human serum in Western blotting experiment, indicating that it is an antigen of strong antigenicity. The high level of antibody titers (1:204,800) showed that CsATP-? has a powerful immunogenicity. Both the increased level and the change trend of IgG1/IgG2a subtypes in serum showed that the rCsATP-? can induce strong combined Th1/Th2 immune responses in rats and stimulate the immune response changes to the dominant Th2 from Th1 along with long time infection. The results of immunoblot and immunolocalization demonstrated that CsATP-? was consecutively expressed at various developmental stages of the parasite, which was supported by real-time PCR analysis. In immunohistochemistry, CsATP-? was localized on the intestine, vitellarium, and testicle of an adult worm and excretory bladder of metacercaria, implying that CsATP-? may relate to energy intake and metabolism. This fundamental study would contribute to further researches that are related to growth and development and immunomodulation of C. sinensis.
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JNK confers 5-fluorouracil resistance in p53-deficient and mutant p53-expressing colon cancer cells by inducing survival autophagy.
Sci Rep
PUBLISHED: 01-24-2014
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Deficiency or mutation in the p53 tumor suppressor gene commonly occurs in human cancer and can contribute to disease progression and chemotherapy resistance. Currently, although the pro-survival or pro-death effect of autophagy remains a controversial issue, increasing data seem to support the idea that autophagy facilitates cancer cell resistance to chemotherapy treatment. Here we report that 5-FU treatment causes aberrant autophagosome accumulation in HCT116 p53(-/-) and HT-29 cancer cells. Specific inhibition of autophagy by 3-MA, CQ or small interfering RNA treatment targeting Atg5 or Beclin 1 can potentiate the re-sensitization of these resistant cancer cells to 5-FU. In further analysis, we show that JNK activation and phosphorylation of Bcl-2 are key determinants in 5-FU-induced autophagy. Inhibition of JNK by the compound SP600125 or JNK siRNA suppressed autophagy and phosphorylation of c-Jun and Bcl-2 but increased 5-FU-induced apoptosis in both HCT116 p53(-/-) and HT29 cells. Taken together, our results suggest that JNK activation confers 5-FU resistance in HCT116 p53(-/-) and HT29 cells by promoting autophagy as a pro-survival effect, likely via inducing Bcl-2 phosphorylation. These results provide a promising strategy to improve the efficacy of 5-FU-based chemotherapy for colorectal cancer patients harboring a p53 gene mutation.
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Expression of human transferrin can be regulated effectively by rabbit transferrin regulatory elements in transgenic mice.
Biotechnol. Lett.
PUBLISHED: 01-24-2014
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Human transferrin (hTF) belongs to the iron-binding glycoprotein family. It plays an important role in iron transport throughout the body. Transgenic mice are a good model to study how to produce functional hTF on a large-scale. We have improved the expression of hTF and investigated its regulatory mechanism in transgenic mice. Three expression constructs were prepared in which hTF expression was controlled by different regulatory cassettes of rabbit transferrin (rTF). hTF was secreted into serum of transgenic mice when its expression was controlled by the rTF promoter and enhancer, whereas the rTF enhancer in tandem with the rTF promoter repressed hTF secretion into milk. A significant inverse relationship between methylation of the rTF promoter and hTF expression was observed in liver, heart, mammary gland, and muscle of transgenic mice. The highest concentration of hTF was 700 ?g/ml in milk.
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Histone deacetylase 4 selectively contributes to podocyte injury in diabetic nephropathy.
Kidney Int.
PUBLISHED: 01-18-2014
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Studies have highlighted the importance of histone deacetylase (HDAC)-mediated epigenetic processes in the development of diabetic complications. Inhibitors of HDAC are a novel class of therapeutic agents in diabetic nephropathy, but currently available inhibitors are mostly nonselective inhibit multiple HDACs, and different HDACs serve very distinct functions. Therefore, it is essential to determine the role of individual HDACs in diabetic nephropathy and develop HDAC inhibitors with improved specificity. First, we identified the expression patterns of HDACs and found that, among zinc-dependent HDACs, HDAC2/4/5 were upregulated in the kidney from streptozotocin-induced diabetic rats, diabetic db/db mice, and in kidney biopsies from diabetic patients. Podocytes treated with high glucose, advanced glycation end products, or transforming growth factor-? (common detrimental factors in diabetic nephropathy) selectively increased HDAC4 expression. The role of HDAC4 was evaluated by in vivo gene silencing by intrarenal lentiviral gene delivery and found to reduce renal injury in diabetic rats. Podocyte injury was associated with suppressing autophagy and exacerbating inflammation by HDAC4-STAT1 signaling in vitro. Thus, HDAC4 contributes to podocyte injury and is one of critical components of a signal transduction pathway that links renal injury to autophagy in diabetic nephropathy.
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NLRP3 deficiency ameliorates neurovascular damage in experimental ischemic stroke.
J. Cereb. Blood Flow Metab.
PUBLISHED: 01-15-2014
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Although the innate immune response to induce postischemic inflammation is considered as an essential step in the progression of cerebral ischemia injury, the role of innate immunity mediator NLRP3 in the pathogenesis of ischemic stroke is unknown. In this study, focal ischemia was induced by middle cerebral artery occlusion in NLRP3(-/-), NOX2(-/-), or wild-type (WT) mice. By magnetic resonance imaging (MRI), Evans blue permeability, and electron microscopic analyses, we found that NLRP3 deficiency ameliorated cerebral injury in mice after ischemic stroke by reducing infarcts and blood-brain barrier (BBB) damage. We further showed that the contribution of NLRP3 to neurovascular damage was associated with an autocrine/paracrine pattern of NLRP3-mediated interleukin-1? (IL-1?) release as evidenced by increased brain microvessel endothelial cell permeability and microglia-mediated neurotoxicity. Finally, we found that NOX2 deficiency improved outcomes after ischemic stroke by mediating NLRP3 signaling. This study for the first time shows the contribution of NLRP3 to neurovascular damage and provides direct evidence that NLRP3 as an important target molecule links NOX2-mediated oxidative stress to neurovascular damage in ischemic stroke. Pharmacological targeting of NLRP3-mediated inflammatory response at multiple levels may help design a new approach to develop therapeutic strategies for prevention of deterioration of cerebral function and for the treatment of stroke.
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Identification, sequence analysis, and characterization of serine/threonine protein kinase 17A from Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 01-12-2014
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This is the first report of a novel protein from Clonorchis sinensis (C. sinensis), serine/threonine protein kinase 17A (CsSTK17A), which belongs to a member of the death-associated protein kinase (DAPK) family known to regulate diverse biological processes. The full-length sequence encoding CsSTK17A was isolated from C. sinensis adult cDNA plasmid library. Two transcribed isoforms of the gene were identified from the genome of C. sinensis. CsSTK17A contains a kinase domain at the N-terminus that shares a degree of conservation with the DAPK families. Besides, the catalytic domain contains 11 subdomains conserved among STKs and shares the highest identity with STK from Schistosoma mansoni (55.9%). Three-dimensional structure of CsSTK17A displays the canonical STK fold, including the helix C, P-loop, and the activation loop. We obtained recombinant CsSTK17A (rCsSTK17A) and anti-rCsSTK17A IgG. The rCsSTK17A could be probed by anti-rCsSTK17A rat serum, C. sinensis-infected rat serum and the sera from rats immunized with C. sinensis excretory-secretory products, indicating that it is a circulating antigen possessing a strong immunocompetence. Moreover, quantitative RT-PCR and western blotting analyses revealed that CsSTK17A exhibited the highest mRNA and protein expression level in eggs, followed by metacercariae and adult worms. Intriguingly, in the immunolocalization assay, CsSTK17A was intensively localized to the operculum region of eggs in uterus, as well as the vitelline gland of both adult worm and metacercaria, implying that the protein was associated with the reproduction and development of C. sinensis. Overall, these fundamental studies might contribute to further researches on signaling systems of the parasite.
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Autophagy: A novel therapeutic target for hepatocarcinoma (Review).
Oncol Lett
PUBLISHED: 01-09-2014
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Autophagy is a highly conserved intracellular degradation process and plays an important role in hepatocarcinogenesis. Available data show that autophagy is involved in anti-hepatocarcinoma (HCC) therapies. Autophagy regulation involves a novel target for overcoming therapeutic resistance and sensitizing HCC to currently therapeutic methods. This is a systematic review on the interface of autophagy and the development of HCC and outlining the role of autophagy in current anti-HCC approaches. Understanding the significance of autophagy in anti-HCC therapy may offer a novel therapeutic target for improving anti-cancer efficacy and prolong survival for HCC patients.
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Tetramethylpyrazine analogue CXC195 protects against cerebral ischemia/reperfusion-induced apoptosis through PI3K/Akt/GSK3? pathway in rats.
Neurochem. Int.
PUBLISHED: 01-09-2014
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CXC195 showed strongest protective effects among the ligustrazine derivatives in cells and prevented apoptosis induced by H2O2 injury. We recently demonstrated that CXC195 protected against cerebral ischemia/reperfusion (I/R) injury by its antioxidant activity. However, whether the anti-apoptotic action of CXC195 is involved in cerebral I/R injury is unknown. Here, we investigated the role of CXC195 in apoptotic processes induced by cerebral I/R and the possible signaling pathways. Male Wistar rats were submitted to transient middle cerebral artery occlusion for 2h, followed by 24h reperfusion. CXC195 was injected intraperitoneally at 2h and 12h after the onset of ischemia. The number of apoptotic cells was measured by TUNEL assay, apoptosis-related protein cleaved caspase-3, Bcl-2, Bax and the phosphorylation levels of Akt and GSK3? in ischemic penumbra were assayed by western blot. The results showed that administration of CXC195 at the doses of 3mg/kg and 10mg/kg significantly inhibited the apoptosis by decreasing the number of apoptotic cells, decreasing the level of cleaved caspase-3 and Bax, and increasing the level of Bcl-2 in rats subjected to I/R injury. Simultaneously, CXC195 treatment markedly increased the phosphorylation of Akt and GSK3?. Blockade of PI3K activity by wortmannin, dramatically abolished its anti-apoptotic effect and lowered both Akt and GSK3? phosphorylation levels. Our study firstly demonstrated that CXC195 protected against cerebral I/R injury by reducing apoptosis in vivo and PI3K/Akt/GSK3? pathway involved in the anti-apoptotic effect.
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Surface display of Clonorchis sinensis enolase on Bacillus subtilis spores potentializes an oral vaccine candidate.
Vaccine
PUBLISHED: 01-06-2014
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Clonorchis sinensis (C. sinensis) infections remain the common public health problem in freshwater fish consumption areas. New effective prevention strategies are still the urgent challenges to control this kind of foodborne infectious disease. The biochemical importance and biological relevance render C. sinensis enolase (Csenolase) as a potential vaccine candidate. In the present study, we constructed Escherichia coli/Bacillus subtilis shuttle genetic engineering system and investigated the potential of Csenolase as an oral vaccine candidate for C. sinensis prevention in different immunization routes. Our results showed that, compared with control groups, both recombinant Csenolase protein and nucleic acid could induce a mixed IgG1/IgG2a immune response when administrated subcutaneously (P<0.001), intraperitoneally (P<0.01) and intramuscularly (P<0.001) with worm reduction rate of 56.29%, 15.38% and 37.42%, respectively. More importantly, Csenolase could be successfully expressed as a fusion protein (55kDa) on B. subtilis spore indicated by immunoblot and immunofluorescence assays. Killed spores triggered reactive Th1/Th2 immune response and exhibited protective efficacy against C. sinensis infection. Csenolase derived oral vaccine conferred worm reduction rate and egg reduction rate at 60.07% (P<0.001) and 80.67% (P<0.001), respectively. The shuttle genetic engineering system facilitated the development of oral vaccine with B. subtilis stably overexpressing target protein. Comparably vaccinal trails with Csenolase in different immunization routes potentialize Csenolase an oral vaccine candidate in C. sinensis prevention.
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RNAi-mediated silencing of enolase confirms its biological importance in Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 01-03-2014
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Clonorchis sinensis (C. sinensis) infection is still a common public health problem in freshwater fish consumption areas in Asian countries. More molecular evidence are required to speed up the prevention strategies to control this kind of infectious disease. In the present study, to confirm the biological importance of Csenolase followed by our previous observations of the key metabolic enzyme, we explored the RNA silence effect of the Csenolase-derived RNA interference (RNAi) in C. sinensis. The extramembranous region aa105-226 was selected as the target sequence of RNA silence. Csenolase-derived double strand RNA (dsRNA-Csenolase, 366 bp) was synthetized and delivered into C. sinensis by soaking approach. The penetration of dsRNA into adult worms and metacercariae was tracked using fluorescently labeled RNA. Western blotting and qRT-PCR experiments were performed to determine dsRNA-Csenolase-silencing effect. Our results showed that, after incubating for 120 h, dsRNA-Csenolase could effectively target and downregulate the expression of Csenolase in both adult worms (P < 0.001) and metacercariae (P < 0.01), resulting in a remarkable killing effect on C. sinensis adult worms (P < 0.01). Fluorescent Cy3-labeled dsRNA was mostly deposited in the uterus and vitellarium of adult worm and in the cyst wall of metacercaria. The present study is the first report of RNAi trials in C. sinensis, allowing further applications in identifying functional genes in C. sinensis.
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Sequence analysis and molecular characterization of Clonorchis sinensis hexokinase, an unusual trimeric 50-kDa glucose-6-phosphate-sensitive allosteric enzyme.
PLoS ONE
PUBLISHED: 01-01-2014
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Clonorchiasis, which is induced by the infection of Clonorchis sinensis (C. sinensis), is highly associated with cholangiocarcinoma. Because the available examination, treatment and interrupting transmission provide limited opportunities to prevent infection, it is urgent to develop integrated strategies to prevent and control clonorchiasis. Glycolytic enzymes are crucial molecules for trematode survival and have been targeted for drug development. Hexokinase of C. sinensis (CsHK), the first key regulatory enzyme of the glycolytic pathway, was characterized in this study. The calculated molecular mass (Mr) of CsHK was 50.0 kDa. The obtained recombinant CsHK (rCsHK) was a homotrimer with an Mr of approximately 164 kDa, as determined using native PAGE and gel filtration. The highest activity was obtained with 50 mM glycine-NaOH at pH 10 and 100 mM Tris-HCl at pH 8.5 and 10. The kinetics of rCsHK has a moderate thermal stability. Compared to that of the corresponding negative control, the enzymatic activity was significantly inhibited by praziquantel (PZQ) and anti-rCsHK serum. rCsHK was homotropically and allosterically activated by its substrates, including glucose, mannose, fructose, and ATP. ADP exhibited mixed allosteric effect on rCsHK with respect to ATP, while inorganic pyrophosphate (PPi) displayed net allosteric activation with various allosteric systems. Fructose behaved as a dose-dependent V activator with the substrate glucose. Glucose-6-phosphate (G6P) displayed net allosteric inhibition on rCsHK with respect to ATP or glucose with various allosteric systems in a dose-independent manner. There were differences in both mRNA and protein levels of CsHK among the life stages of adult worm, metacercaria, excysted metacercaria and egg of C. sinensis, suggesting different energy requirements during different development stages. Our study furthers the understanding of the biological functions of CsHK and supports the need to screen for small molecule inhibitors of CsHK to interfere with glycolysis in C. sinensis.
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HIV-derived ssRNA binds to TLR8 to induce inflammation-driven macrophage foam cell formation.
PLoS ONE
PUBLISHED: 01-01-2014
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Even though combined anti-retroviral therapy (cART) dramatically improves patient survival, they remain at a higher risk of being afflicted with non-infectious complications such as cardiovascular disease (CVD). This increased risk is linked to persistent inflammation and chronic immune activation. In this study, we assessed whether this complication is related to HIV-derived ssRNAs inducing in macrophages increases in TNF? release through TLR8 activation leading to foam cell formation. HIV ssRNAs induced foam cell formation in monocyte-derived macrophages (MDMs) in a dose-dependent manner. This response was reduced when either endocytosis or endosomal acidification was inhibited by dynasore or chloroquine, respectively. Using a flow cytometry FRET assay, we demonstrated that ssRNAs bind to TLR8 in HEK cells. In MDMs, ssRNAs triggered a TLR8-mediated inflammatory response that ultimately lead to foam cell formation. Targeted silencing of the TLR8 and MYD88 genes reduced foam cell formation. Furthermore, foam cell formation induced by these ssRNAs was blocked by an anti-TNF? neutralizing antibody. Taken together in MDMs, HIV ssRNAs are internalized; bind TLR8 in the endosome followed by endosomal acidification. TLR8 signaling then triggers TNF? release and ultimately leads to foam cell formation. As this response was inhibited by a blocking anti-TNF? antibody, drug targeting HIV ssRNA-driven TLR8 activation may serve as a potential therapeutic target to reduce chronic immune activation and inflammation leading to CVD in HIV+ patients.
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Enhanced oral absorption and therapeutic effect of acetylpuerarin based on D-?-tocopheryl polyethylene glycol 1000 succinate nanoemulsions.
Int J Nanomedicine
PUBLISHED: 01-01-2014
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Acetylpuerarin (AP), because of its lower water solubility, shows poor absorption that hinders its therapeutic application. Thus, the aim of this study was to prepare nanoemulsions for AP, enhance its oral bioavailability, and thus improve the therapeutic effect.
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Use of metformin alone is not associated with survival outcomes of colorectal cancer cell but AMPK activator AICAR sensitizes anticancer effect of 5-fluorouracil through AMPK activation.
PLoS ONE
PUBLISHED: 01-01-2014
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Colorectal cancer (CRC) is still the third most common cancer and the second most common causes of cancer-related death around the world. Metformin, a biguanide, which is widely used for treating diabetes mellitus, has recently been shown to have a suppressive effect on CRC risk and mortality, but not all laboratory studies suggest that metformin has antineoplastic activity. Here, we investigated the effect of metformin and AMPK activator AICAR on CRC cells proliferation. As a result, metformin did not inhibit cell proliferation or induce apoptosis for CRC cell lines in vitro and in vivo. Different from metformin, AICAR emerged antitumor activity and sensitized anticancer effect of 5-FU on CRC cells in vitro and in vivo. In further analysis, we show that AMPK activation may be a key molecular mechanism for the additive effect of AICAR. Taken together, our results suggest that metformin has not antineoplastic activity for CRC cells as a single agent but AMPK activator AICAR can induce apoptosis and enhance the cytotoxic effect of 5-FU through AMPK activation.
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NOD2 Deficiency Protects against Cardiac Remodeling after Myocardial Infarction in Mice.
Cell. Physiol. Biochem.
PUBLISHED: 12-04-2013
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Background/Aims: Although the pathogenesis of myocardial infarction (MI) is multifactorial, activation of innate immune system to induce inflammation has emerged as a key pathophysiological process in MI. NOD2, one member of the NOD-like receptor (NLR) family, plays an important role in the innate immune response. This study was to examine the role of NOD2 during MI. Methods: MI was induced by permanent ligation of the left coronary artery in wild type and NOD2(-/-) mice and cardiac fibroblasts were isolated. Results: NOD2 expression was significantly increased in myocardium in post-MI mice. NOD2 deficiency improved cardiac dysfunction and remodeling after MI as evidenced by echocardiographic analysis, reduced the levels of cytokines, inflammatory cell infiltration and matrix metalloproteinase-9 (MMP-9) activity. In vitro, we further found that NOD2 activation induced the activation of MAPK signaling pathways, production of proinflammatory mediators and MMP-9 activity in cardiac fibroblasts. Conclusions: Our studies demonstrate that NOD2 is a critical component of a signal transduction pathway that links cardiac injury by exacerbation of inflammation and MMP-9 activity. Pharmacological targeting of NOD2-mediated signaling pathways may provide a novel approach to treatment of cardiovascular diseases. © 2014 S. Karger AG, Basel.
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Molecular Characterization of Severin fromClonorchis sinensis Excretory/Secretory Products and Its Potential Anti-apoptotic Role in Hepatocarcinoma PLC Cells.
PLoS Negl Trop Dis
PUBLISHED: 12-01-2013
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Clonorchiasis, caused by the infection of Clonorchis sinensis (C. sinensis), is a kind of neglected tropical disease, but it is highly related to cholangiocarcinoma and hepatocellular carcinoma (HCC). It has been well known that the excretory/secretory products of C. sinensis (CsESPs) play key roles in clonorchiasis associated carcinoma. From genome and transcriptome of C. sinensis, we identified one component of CsESPs, severin (Csseverin), which had three putative gelsolin domains. Its homologues are supposed to play a vital role in apoptosis resistance of tumour cell.
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An all solid-state high-voltage ns trigger generator based on magnetic pulse compression and transmission line transformer.
Rev Sci Instrum
PUBLISHED: 10-05-2013
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Innovative design of an all solid-state high-voltage ns trigger generator, based on magnetic pulse compression and transmission line transformer, is presented. The repetitive trigger pulse generator was developed to trigger a 700 kV trigatron, which has been used to pulse a repetitive intense electron beam accelerator with Tesla transformer charged double pulse forming lines (PFLs). Experimental results show that the trigger pulse generator could produce 180 kV 65 ns duration pulses with a rise time of 20 ns. The repetitive trigger pulses have nice uniform in the voltage waveform. The control time jitter is less then 3 ns. Owing to its good stability and low time jitter, the high-voltage trigger generator is an excellent candidate to trigger the repetitive accelerator.
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Molecular characterization and immune modulation properties of Clonorchis sinensis-derived RNASET2.
Parasit Vectors
PUBLISHED: 09-04-2013
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Clonorchis sinensis (C. sinensis, Cs) is a trematode parasite that often causes chronic cumulative infections in the hepatobiliary ducts of the host and can lead to pathological changes by continuously released excretory/secretory proteins (ESPs). A T2 ribonuclease in trematode ESPs, has been identified as a potent regulator of dendritic cell (DCs) modulation. We wondered whether there was a counterpart present in CsESPs with similar activity. To gain a better understanding of CsESPs associated immune responses, we identified and characterized RNASET2 of C. sinensis (CsRNASET2) in this paper.
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Comparing the effect of biosurfactant and chemical surfactant on bubble hydrodynamics in a flotation column.
Water Sci. Technol.
PUBLISHED: 08-30-2013
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Bubble hydrodynamics is fundamental to the performance of the flotation process widely used in the separation industry. To compare the effect of biosurfactants and chemical synthetic surfactants on bubble hydrodynamics in the flotation process, the motion of a single bubble and the size distribution of bubble swarms in various surfactants (rhamnolipid, tea saponin and Triton X-100) solutions were observed directly using a high-speed video camera in a laboratory scale flotation column. Bubble trajectory, dimensions, velocity and size distribution were then determined through image analysis. The results indicated that the addition of biosurfactants had the same significant effects on bubble motion and size distribution as chemosynthetic surfactants. The biosurfactant effect on bubble behavior was also found to depend on their type and concentration. In general, the effect of tea saponin was stronger than another biosurfactant (rhamnolipid) used in the present study. The present findings implied that some biosurfactants like tea saponin can replace chemosynthetic surfactants in controlling bubble behavior in flotation operation. This will contribute to promoting the use of green environmentally friendly flotation agents in the separation industry.
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p38 and JNK MAPK pathways control the balance of apoptosis and autophagy in response to chemotherapeutic agents.
Cancer Lett.
PUBLISHED: 08-26-2013
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The Mitogen Activated Protein Kinase (MAPK) signaling plays a critical role in the outcome and the sensitivity to anticancer therapies. Activated MAPK can transmit extracellular signals to regulate cell growth, proliferation, differentiation, migration, apoptosis and so on. Apoptosis as well as macroautophagy (hereafter referred to as autophagy) can be induced by extracellular stimuli such the treatment of chemotherapeutic agents, resulting in different cell response to these drugs. However, the molecular mechanisms mediating these two cellular processes remain largely unknown. Recently, several studies provide new insights into p38 and JNK MAPK pathways function in the control of the balance of autophagy and apoptosis in response to genotoxic stress. Our increased understanding of the role of p38 and JNK MAPK pathways in regulating the balance of autophagy and apoptosis will hopefully provide prospective strategies for cancer therapy.
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Naringenin protects against 6-OHDA-induced neurotoxicity via activation of the Nrf2/ARE signaling pathway.
Neuropharmacology
PUBLISHED: 08-07-2013
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There is increasing evidence that oxidative stress is critically involved in the pathogenesis of Parkinsons disease (PD), suggesting that pharmacological targeting of the antioxidant machinery may have therapeutic value. Naringenin, a natural flavonoid compound, has been reported to possess neuroprotective effect against PD related pathology; however the mechanisms underlying its beneficial effects are poorly defined. Thus, the purpose of the present study was to investigate the potential neuroprotective role of naringenin and to delineate its mechanism of action against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in models of PD both in vitro and in vivo. Naringenin treatment resulted in an increase in nuclear factor E2-related factor 2 (Nrf2) protein levels and subsequent activation of antioxidant response element (ARE) pathway genes in SH-SY5Y cells and in mice. Exposure of SH-SY5Y cells to naringenin provided protection against 6-OHDA-induced oxidative insults that was dependent on Nrf2, since treatment with Nrf2 siRNA failed to block against 6-OHDA neurotoxicity or induce Nrf2-dependent cytoprotective genes in SH-SY5Y cells. In mice, oral administration of naringenin resulted in significant protection against 6-OHDA-induced nigrostriatal dopaminergic neurodegeneration and oxidative damage. Our results indicate that activation of Nrf2/ARE signaling by naringenin is strongly associated with its neuroprotective effects against 6-OHDA neurotoxicity and suggest that targeting the Nrf2/ARE pathway may be a promising approach for therapeutic intervention in PD.
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Anti-inflammatory Effect of Acetylpuerarin on Eicosanoid Signaling Pathway in Primary Rat Astrocytes.
J. Mol. Neurosci.
PUBLISHED: 07-26-2013
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Astrocytes activation has been implicated in the inflammatory responses underlying brain injury and neurodegenerative diseases including bacterial infections, cerebral ischemia, and Parkinsons diseases. Acetylpuerarin is a newly modified isoflavone based on puerarin that has neuroprotective and antioxidant effects. In this study, we investigated the anti-inflammatory action of acetylpuerarin in regulating the eicosanoids generation and its underlying molecular mechanisms in lipopolysaccharide (LPS)-induced production of arachidonic acid (AA) metabolites in primary rat astrocytes. The results showed that acetylpuerarin concentration dependently inhibited the LPS-induced production of AA metabolites such as prostaglandin E2 (PGE2) and leukotriene C4 (LTC4), and acetylpuerarin significantly attenuated the expression and immunoreactivity of group V secretory phospholipase A2 (sPLA2) protein induced by LPS in astrocytes. Furthermore, in astrocytes pretreated with acetylpuerarin, the time course of phosphorylation of extracellular signal-regulated kinase (ERK)1/2 and of cytosolic PLA2 alpha (cPLA2?) and expression of transcription factors, nuclear factor kappa B (NF-?B), was markedly truncated. Acetylpuerarin concentration dependently abolished the LPS-induced expressions of AA-metabolizing enzymes including cyclooxygenase-2 (COX-2) and lipooxygenase-5 (LOX-5). This study indicates that acetylpuerarin inhibited LPS-induced AA-metabolizing enzymes and AA metabolites in astrocytes via downregulation expression of group V sPLA2 and phosphorylation of ERK1/2, cPLA2?, and NF-?B. These findings reveal, in part, the molecular basis underlying the anti-inflammatory properties of acetylpuerarin.
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Novel role of NOD2 in mediating Ca2+ signaling: evidence from NOD2-regulated podocyte TRPC6 channels in hyperhomocysteinemia.
Hypertension
PUBLISHED: 07-15-2013
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Although hyperhomocysteinemia (hHcys) has been recognized as an important independent risk factor in the progression of end-stage renal disease and in the development of cardiovascular complications related to end-stage renal disease, the mechanisms triggering the pathogenic actions of hHcys are not yet fully understood. The present study was designed to investigate the contribution of nucleotide-binding oligomerization domain containing 2 (NOD2), an intracellular innate immunity mediator, to the development of glomerulosclerosis in hHcys. Our results showed that NOD2 deficiency ameliorated renal injury in mice with hHcys. We further discovered the novel role of NOD2 in mediating Ca(2+) signaling and found that homocysteine-induced NOD2 expression enhanced transient receptor potential cation channel 6 (TRPC6) expression and TRPC6-mediated calcium influx and currents, leading to intracellular Ca(2+) release, ultimately resulting in podocyte cytoskeleton rearrangement and apoptosis. Moreover, we found that nephrin expression was downregulated dependently by NOD2, and overexpression of nephrin attenuated homocysteine-induced TRPC6 expression in podocytes. The results add evidence to support the essential role of nephrin in mediating NOD2-induced TRPC6 expression in hHcys. In conclusion, our results for the first time establish a previously unknown function of NOD2 for the regulation of TRPC6 channels, suggesting that TRPC6-dependent Ca(2+) signaling is one of the critical signal transduction pathways that links innate immunity mediator NOD2 to podocyte injury. Pharmacological targeting of NOD2 signaling pathways at multiple levels may help design a new approach to develop therapeutic strategies for treatment of hHcys-associated end-stage renal disease.
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NOX2 deficiency ameliorates cerebral injury through reduction of complexin II-mediated glutamate excitotoxicity in experimental stroke.
Free Radic. Biol. Med.
PUBLISHED: 06-29-2013
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Although NADPH oxidase (NOX)-mediated oxidative stress is considered one of the major mechanisms triggering the pathogenic actions of ischemic stroke and very recent studies have indicated that NADPH oxidase is a major source of reactive oxygen species (ROS) production controlling glutamate release, how neuronal NADPH oxidase activation is coupled to glutamate release is not well understood. Therefore, in this study, we used an in vivo transient middle cerebral artery occlusion model and in vitro primary cell cultures to test whether complexins, the regulators of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes necessary for vesicle fusion, are associated with NOX2-derived ROS and contribute to glutamate-mediated excitotoxicity in ischemic stroke. In this study, we first identified the upregulation of complexin II in the ischemic brain and evaluated its potential role in ischemic stroke showing that gene silencing of complexin II ameliorated cerebral injury as evidenced by reduced infarction volume, neurological deficit, and neuron necrosis accompanied by decreased glutamate levels, consistent with the results from NOX2(-/-) mice with ischemic stroke. We further demonstrated that complexin II expression was mediated by NOX2 in primary cultured neurons subjected to oxygen-glucose deprivation (OGD) and contributed to OGD-induced glutamate release and neuron necrosis via SNARE signaling. Taken together, these findings for the first time provide evidence that complexin II is a central target molecule that links NADPH oxidase-derived ROS to glutamate-mediated neuronal excitotoxicity in ischemic stroke.
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Tetramethylpyrazine analogue CXC195 protects against cerebral ischemia/reperfusion injury in the rat by an antioxidant action via inhibition of NADPH oxidase and iNOS expression.
Pharmacology
PUBLISHED: 06-03-2013
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This study was conducted to investigate the protective effects of CXC195, a tetramethylpyrazine analogue, in acute focal cerebral ischemia/reperfusion (I/R) injury in rats and to elucidate the potential mechanism.
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Spatial-division-multiplexing addressed fiber laser hydrophone array.
Opt Lett
PUBLISHED: 06-01-2013
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The fiber laser hydrophone is compact, and it is easy to construct an array by using the multiplexing technique. However, the number of hydrophones multiplexed in the array through wavelength-division-multiplexing (WDM) technology is limited. In order to expand the array, a spatial division multiplexing (SDM) method for addressing a fiber laser hydrophone array is researched. An optical switch is used in such array, and four distributed feedback (DFB) fiber laser hydrophones are addressed by switch channels. Experimental results show that the switch channels crosstalk crucially influences the hydrophone signals signal-to-noise ratio (SNR). In order to get good SNR, the crosstalk of the switch channels should be lower than -20 dB. Each DFB laser in the SDM-addressed array may be replaced with a WDM-addressed array, so a DFB fiber laser hydrophone array with more than 64 elements can be constructed.
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Hydroxysafflor yellow A protects against cerebral ischemia-reperfusion injury by anti-apoptotic effect through PI3K/Akt/GSK3? pathway in rat.
Neurochem. Res.
PUBLISHED: 05-28-2013
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Hydroxysafflor yellow A (HSYA) is the major active chemical component of the flower of the safflower plant, Carthamus tinctorius L. Previously, its neuroprotection against cerebral ischemia-reperfusion (I/R) injury was reported by anti-oxidant action and suppression of thrombin generation. Here, we investigate the role of HSYA in cerebral I/R-mediated apoptosis and possible signaling pathways. Male Wistar rats were subjected to transient middle cerebral artery occlusion for 2 h, followed by 24 h reperfusion. HSYA was administered via tail-vein injection just 15 min after occlusion. The number of apoptotic cells was measured by TUNEL assay, apoptosis-related proteins Bcl-2, Bax and the phosphorylation levels of Akt and GSK3? in ischemic penumbra were assayed by western blot. The results showed that administration of HSYA at the doses of 4 and 8 mg/kg significantly inhibited the apoptosis by decreasing the number of apoptotic cells and increasing the Bcl-2/Bax ratio in rats subjected to I/R injury. Simultaneously, HSYA treatment markedly increased the phosphorylations of Akt and GSK3?. Blockade of PI3K activity by wortmannin dramatically abolished its anti-apoptotic effect and lowered both Akt and GSK3? phosphorylation levels. Taken together, these results suggest that HSYA protects against cerebral I/R injury partly by reducing apoptosis via PI3K/Akt/GSK3? signaling pathway.
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Coinfection with Clonorchis sinensis modulates murine host response against Trichinella spiralis infection.
Parasitol. Res.
PUBLISHED: 04-18-2013
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Concomitant infections of different species of parasites are common in the field. Infection with one parasite species likely triggers host responses that may influence the subsequent infection of another species and alter disease outcomes. So far, the majority of studies have focused on single species parasite infection, and the mechanisms of protection induced by the first parasite infection against the secondary infection remain poorly defined. In this study, we assess the impact of trematode Clonorchis sinensis infection on the course of another tissue nematode Trichinella spiralis challenge. We observed that mice with preexisting C. sinensis infection had lower worm burden of intestinal T. spiralis than those infected with T. spiralis alone; mice with preexisting C. sinensis also had severe enteric histopathological changes and higher counts of intestinal Paneth cells in responses to T. spiralis challenge. The mRNA levels of interleukin (IL)-4, IL-10, IL-13, and tumor necrosis factor (TNF)-? from the small intestine and spleen of the different groups were analyzed using quantitative real-time polymerase chain reaction. Compared with that in mice infected with T. spiralis alone, the mRNA expression of IL-13 was significantly increased in the small intestine tissues and IL-4, IL-13, and TNF-? were significantly increased in the spleen tissues in the dually infected mice. Our findings suggest that a "preexisting" trematode infection of C. sinensis is a factor which contributes to reducing the establishment of T. spiralis adult worms in the small intestine.
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Cyclic thiourea/urea functionalized triphenylamine-based dyes for high-performance dye-sensitized solar cells.
Org. Lett.
PUBLISHED: 03-18-2013
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Six cyclic thiourea/urea functionalized triphenylamine-based dyes (AZ1-AZ6) containing 2-cyanoacrylic acid as an acceptor and various linkers (phenyl, biphenyl, and bithiophene) were synthesized. They exhibited high photovoltaic performance owing to an improved short-circuit photocurrent density (J(sc)) and open-circuit voltage (V(oc)). Among them, AZ6 bearing a cyclic thiourea group and bithiophene linker showed the highest power conversion efficiency (PCE) up to 7.29%, which was comparable to that of N719 (PCE = 7.36%).
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Molecular characterization and expression of Rab7 from Clonorchis sinensis and its potential role in autophagy.
Parasitol. Res.
PUBLISHED: 03-15-2013
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Accumulating evidences suggest that Rab7 GTPase is important for the normal progression of autophagy. However, the role of Rab7 GTPase in regulation of autophagy in Clonorchis sinensis is not known. In this study, a gene encoding Rab7 was isolated from C. sinensis adult cDNA. Recombinant CsRab7 was expressed and purified from Escherichia coli. CsRab7 transcripts were detected in the cDNA of adult worm, metacercaria, cercaria, and egg of C. sinensis, and were highly expressed in the metacercaria. Immunohistochemical localization results revealed that CsRab7 was specifically deposited on the vitellarium and eggs of adult worm. Furthermore, EGFP signal of CsRab7WT and the active mutant CsRab7Q67L were associated with autophagic vesicles in transiently transfected 293T cells. It is concluded from the present study that CsRab7 GTPase possibly contributes to the development of C. sinensis and that the autophagy pathway could be an important site of action with respect to the developmental role of CsRab7 in C. sinensis.
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Chitinase inhibition promotes atherosclerosis in hyperlipidemic mice.
Am. J. Pathol.
PUBLISHED: 03-12-2013
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Chitinase 1 (CHIT1) is secreted by activated macrophages. Chitinase activity is raised in atherosclerotic patient sera and is present in atherosclerotic plaque. However, the role of CHIT1 in atherosclerosis is unknown. Preliminary studies of atherosclerosis in cynomolgous monkeys revealed CHIT1 to be closely correlated with areas of macrophage infiltration. Thus, we investigated the effects of a chitinase inhibitor, allosamidin, on macrophage function in vitro and on atherosclerotic development in vivo. In RAW264.7 cells, allosamidin elevated monocyte chemoattractant protein 1 and tumor necrosis factor alpha expression, and increased activator protein 1 and nuclear factor-?B transcriptional activity. Although inducible nitric oxide synthase, IL-6, and IL-1? expression were increased, Arg1 expression was decreased by chitinase inhibition, suggesting that suppression of CHIT1 activity polarizes macrophages into a M1 phenotype. Allosamidin decreased scavenger receptor AI, CD36, ABCA1, and ABCG1 expression which led to suppression of cholesterol uptake and apolipoprotein AI-mediated cholesterol efflux in macrophages. These effects were confirmed with CHIT1 siRNA transfection and CHIT1 plasmid transfection experiments in primary macrophages. Apolipoprotein E-deficient hyperlipidemic mice treated for 6 weeks with constant administration of allosamidin and fed an atherogenic diet showed aggravated atherosclerotic lesion formation. These data suggest that CHIT1 exerts protective effects against atherosclerosis by suppressing inflammatory responses and polarizing macrophages toward an M2 phenotype, and promoting lipid uptake and cholesterol efflux in macrophages.
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Directed neuronal differentiation of mouse embryonic and induced pluripotent stem cells and their gene expression profiles.
Int. J. Mol. Med.
PUBLISHED: 03-08-2013
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Embryonic stem cells (ESCs) may be useful as a therapeutic source of cells for the production of healthy tissue; however, they are associated with certain challenges including immunorejection as well as ethical issues. Induced pluripotent stem cells (iPSCs) are a promising substitute since a patients own adult cells would serve as tissue precursors. Ethical concerns prevent a full evaluation of the developmental potency of human ESCs and iPSCs, therefore, mouse iPSC models are required for protocol development and safety assessments. We used a modified culturing protocol to differentiate pluripotent cells from a mouse iPS cell line and two mouse ES cell lines into neurons. Our results indicated that all three pluripotent stem cell lines underwent nearly the same differentiation process when induced to form neurons in vitro. Genomic expression microarray profiling and single-cell RT-qPCR were used to analyze the neural lineage differentiation process, and more than one thousand differentially expressed genes involved in multiple molecular processes relevant to neural development were identified.
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The serological diagnosis of human clonorchiasis by time-resolved fluoroimmunoassay based on GST2-specific IgG4 detection.
Parasitol. Res.
PUBLISHED: 03-01-2013
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Due to its delayed fluorescence of a lanthanide chelate, high accuracy and low background the broad linear range, long fluorescent life-time and large Stokes shift of europium chelates, the time-resolved fluorescence has been developed for higher sensitive immunoassay. In this article, a simple, sensitive and specific method-time-resolved fluoroimmunoassay (TRFIA) was adopted for immunoassay of clonorchiasis, and recombinant glutathione transferases 2 of Clonorchis sinensis (rCsGST2) was used as a diagnostic antigen. To evaluate this novel assay for clinical applications, 409 serum samples were investigated. The diagnostic accuracy of the antigen was evaluated by receiver-operating characteristic (ROC) analysis. The area under the ROC curve (AUC) was 0.965, 95 % confidence interval (CI, 0.946, 0.985). To eliminate the random influence of ambient temperature, test parameters, photometric instruments and so on, the cut-off value was expressed as ratios between the fluorescence of sample and that of a well-defined negative control serum, and the deduced cut-off value was 9.3605. At the optimum cut-off criteria, the technique has a sensitivity of 95.80 %, specificity of 93.60 %. And the cross reactivity revealed that its cross reactivity with Schistosoma japonicum, round worm, hook worm, whip worm, and Toxoplasma gondii was 9.3, 8.3, 7.6, 9.8, and 5.0 %, respectively. Kappa score of agreement between TRFIA and microscopic examination of stools was 0.892, P?
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Expression, immunolocalization, and serological reactivity of a novel sphingomyelin phosphodiesterase-like protein, an excretory/secretory antigen from Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 03-01-2013
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Clonorchiasis, caused by Clonorchis sinensis infection, is a zoonotic parasitic disease of hepatobiliary system in which the proteins released by adult are major pathogenetic factors. In this study, we first characterized a putative sphingomyelin phosphodiesterase (CsSMPase) A-like secretory protein, which was highly expressed in the adult worm. The full-length gene was cloned. The putative protein is of relatively low homology comparing with SMPase from other species, and of rich T cell and B cell epitopes, suggesting that it is an antigen of strong antigenicity. The complete coding sequence of the gene was expressed in the Escherichia coli. The recombinant CsSMPase (rCsSMPase) can be recognized by C. sinensis-infected serum, and the protein immunoserum can recognize a specific band in excretory/secretory products (ESPs) of C. sinensis adult by western blotting. Immunolocalization revealed that CsSMPase was not only localized on tegument, ventral sucker of metacercaria, and the intestine of adult but also on the nearby epithelium of bile duct of the infected Sprague-Dawley rats, implying that CsSMPase was mainly secreted and excreted through adult intestine and directly interacted with bile duct epithelium. Although immunized rats evoked high level antibody response, the antigen level was low in clonorchiasis patients. And the sensitivity and specificity of rCsSMPase were 50.0 % (12/24) and 88.4 % (61/69), in sera IgG-ELISA, respectively. It is likely due to the fact that CsSMPase binding to the plasma membrane of biliary epithelium decreases the antigen immune stimulation.
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Preferential c-axis orientation of ultrathin SnS2 nanoplates on graphene as high-performance anode for Li-ion batteries.
ACS Appl Mater Interfaces
PUBLISHED: 02-28-2013
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A SnS2/graphene (SnS2/G) hybrid was synthesized by a facile one-step solvothermal route using graphite oxide, sodium sulfide, and SnCl4·5H2O as the starting materials. The formation of SnS2 and the reduction of graphite oxide occur simultaneously. Ultrathin SnS2 nanoplates with a lateral size of 5-10 nm are anchored on graphene nanosheets with a preferential (001) orientation, forming a unique plate-on-sheet structure. The electrochemical tests showed that the nanohybrid exhibits a remarkably enhanced cycling stability and rate capability compared with bare SnS2. The excellent electrochemical properties of SnS2/G could be ascribed to the in situ introduced graphene matrix which offers two-dimensional conductive networks, disperses and immobilizes SnS2 nanoplates, buffers the volume changes during cycling, and directs the growth of SnS2 nanoplates with a favorable orientation.
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Protocadherin 17 acts as a tumour suppressor inducing tumour cell apoptosis and autophagy, and is frequently methylated in gastric and colorectal cancers.
J. Pathol.
PUBLISHED: 02-15-2013
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Gastric and colorectal cancers are among the most common cancers worldwide and cause serious cancer mortality. Both epigenetic and genetic disruptions of tumour suppressor genes (TSGs) are frequently involved in their pathogenesis. Here, we studied the epigenetic and genetic alterations of a novel TSG-PCDH17 and its functions in the pathogenesis of these tumours. We found that PCDH17 was frequently silenced and methylated in almost all gastric and colorectal tumour cell lines as well as in ?95% of primary tumours, but not in normal gastric and colonic mucosa. Moreover, its deletion was detected in only 18% of gastric and 12% of colorectal cancer tissues, suggesting that epigenetic and genetic inactivation of PCDH17 are both involved in gastric and colorectal tumourigenesis. PCDH17 protein expression was significantly correlated with low tumour stage and less lymph node metastasis of gastric and colorectal cancer patients, indicating its potential as a tumour marker. Restoring PCDH17 expression inhibited tumour cell growth in vitro and in vivo through promoting apoptosis, as evidenced by increased TUNEL staining and caspase-3 activation. Furthermore, PCDH17-induced autophagy, along with increased numbers of autophagic vacuoles and up-regulated autophagic proteins Atg-5, Atg-12 and LC3B II. Thus, PCDH17 acts as a tumour suppressor, exerting its anti-proliferative activity through inducing apoptosis and autophagy, and is frequently silenced in gastric and colorectal cancers. PCDH17 methylation is a tumour-specific event that could serve as an epigenetic biomarker for these tumours.
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The carcinogenic liver fluke, Clonorchis sinensis: new assembly, reannotation and analysis of the genome and characterization of tissue transcriptomes.
PLoS ONE
PUBLISHED: 01-30-2013
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Clonorchis sinensis (C. sinensis), an important food-borne parasite that inhabits the intrahepatic bile duct and causes clonorchiasis, is of interest to both the public health field and the scientific research community. To learn more about the migration, parasitism and pathogenesis of C. sinensis at the molecular level, the present study developed an upgraded genomic assembly and annotation by sequencing paired-end and mate-paired libraries. We also performed transcriptome sequence analyses on multiple C. sinensis tissues (sucker, muscle, ovary and testis). Genes encoding molecules involved in responses to stimuli and muscle-related development were abundantly expressed in the oral sucker. Compared with other species, genes encoding molecules that facilitate the recognition and transport of cholesterol were observed in high copy numbers in the genome and were highly expressed in the oral sucker. Genes encoding transporters for fatty acids, glucose, amino acids and oxygen were also highly expressed, along with other molecules involved in metabolizing these substrates. All genes involved in energy metabolism pathways, including the ?-oxidation of fatty acids, the citrate cycle, oxidative phosphorylation, and fumarate reduction, were expressed in the adults. Finally, we also provide valuable insights into the mechanism underlying the process of pathogenesis by characterizing the secretome of C. sinensis. The characterization and elaborate analysis of the upgraded genome and the tissue transcriptomes not only form a detailed and fundamental C. sinensis resource but also provide novel insights into the physiology and pathogenesis of C. sinensis. We anticipate that this work will aid the development of innovative strategies for the prevention and control of clonorchiasis.
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Identification and biochemical characterization of adenylate kinase 1 from Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 01-29-2013
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Adenylate kinase 1 is responsible for the conversion of AMP into ADP involved in purine metabolism. In the present study, adenylate kinase 1 gene (CsADK1) was isolated from an adult cDNA library of Clonorchis sinensis, and the recombinant protein was expressed in Escherichia coli. Bioinformatics analysis implied that the putative protein contained 197 amino acids, and some residues in conservative binding sites of CsADK1 were substituted. The structure modeling analysis showed that CsADK1 was composed of a core domain, an NMP-binding domain, and a LID domain, which was just a small loop. It demonstrated that CsADK1 was a short isoform of ADKs. Moreover, CsADK1 was identified as an excretory/secretory product by western blot analysis. Real-time quantitative PCR showed that expression level of CsADK1 at the stage of excysted metacercaria was higher than those of adult worm (18.8-folds, P<0.01), metacercariae (1.5-folds, P<0.01), and eggs (5.6-folds, P<0.01). In addition, histochemistry analysis showed that CsADK1 was extensively distributed in metacercariae and in the vitellaria and eggs of adult worms. The Km and Vmax value for substrate ADP were 2.2 mM and 0.9 mM/min, respectively. The optimal temperature and pH value were 37 °C and from 7.5 to 8.0, respectively. The enzyme activity was highly dependent on Mg2+, and the optimal concentration of Mg2+ was 2 mM. However, the enzyme activity was slightly activated by Ca2+, and Mn2+ has no effect on activity. For monovalent ions, activity was highly activated by K+ and NH4+, but slightly by Li+. Taken together, CsADK1 was a metal ion-dependent enzyme involved in purine metabolism, which was important for development and reproduction, and might be a potential candidate for drug target for clonorchiasis.
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Molecular identification, immunolocalization, and characterization of Clonorchis sinensis calmodulin.
Parasitol. Res.
PUBLISHED: 01-29-2013
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One cDNA clone (Cs18h09) encoding Clonorchis sinensis calmodulin (CsCaM) was isolated from our adult cDNA plasmid library. The open reading frame of CsCaM contains 450 bp which encodes 149 amino acids. CsCaM protein comprises four calcium-binding EF-hand motifs. The amino acid sequence of CsCaM shares very high homology with other species. Quantitative RT-polymerase chain reaction (PCR) revealed that CsCaM mRNA was constitutively transcribed in development cycle stages of the parasite, including adult worm, metacercaria, excysted metacercaria, and egg. In addition, recombinant CsCaM (rCsCaM) was expressed as a soluble protein and anti-rCsCaM rat serum could detect CsCaM in the C. sinensis somatic extracts but not in the C. sinensis excretory-secretory products (ESPs). Moreover, immunolocalization assay showed that CsCaM was located in tegument, intestine, pharynx, and eggs. Furthermore, rCsCaM was found to bind calcium ion (Ca2+) and magnesium (Mg2+) in electrophoretic mobility shift assay. Ca2+ binding increased the ability of rCsCaM to bind the hydrophobic fluorescent probe 8-anilinonaphthalene-1-sulphonate, causing a blue shift in the fluorescence emission from 540 to 515 nm with an excitation wavelength of 380 nm and substantial increase in fluorescence intensity but not Mg2+. Collectively, here we showed the basic characterization of CsCaM and inferred that CsCaM could be a Ca2+ sensor protein, and CsCaM may possibly participate in growth and development of adult worm and egg of C. sinensis through binding Ca2+.
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Identification and immunological characterization of thioredoxin transmembrane-related protein from Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 01-29-2013
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Thioredoxin transmembrane related protein (TMX), a member of thioredoxin superfamily, is localized to the endoplasmic reticulum and possesses a thioredoxin-like domain that plays an important role as an oxidoreductase. The functions of TMX in Clonorchis sinensis remain to be elucidated. In this study, we cloned and characterized a novel TMX of C. sinensis (CsTMX). The CsTMX cDNA sequence contained a 414-nucleotide open-reading frame encoding a protein of 137 amino acids. A thioredoxin domain was found in the position of aa21-117 and contained the putative active-site motif Cys-Pro-Ala-Cys. BLASTx analysis showed that CsTMX shared 39-57% amino acid identities with TMX of other organisms. Quantitative RT-PCR analysis demonstrated that CsTMX was differentially transcribed, with the highest level of expression in the adult worm stage and the lowest expression in egg stage. In addition, immunofluorescence assay showed CsTMX was localized in the tegument, vitelline gland, intestine, and intrauterine eggs of adult worm. Besides, immunoblot assay revealed that the recombinant CsTMX (rCsTMX) could be recognized by the sera from rats infected with C. sinensis and the sera from rats immunized by excretory-secretory products. Furthermore, analysis of the antibody isotype profile revealed that rats subcutaneously immunized with rCsTMX developed rCsTMX-specific antibody, which is dominance of IgG2a in sera. Meanwhile, production of IFN-? was elevated strongly in the supernatants of spleen cell. The results collectively indicated that CsTMX might play an important role in the host-parasite interaction, as well as CsTMX probably involved in immunoregulation of host by inducing Th1-type dominated immune response in rats.
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Transgenically mediated shRNAs targeting conserved regions of foot-and-mouth disease virus provide heritable resistance in porcine cell lines and suckling mice.
Vet. Res.
PUBLISHED: 01-16-2013
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Foot-and-mouth disease virus (FMDV) is responsible for substantial economic losses in livestock breeding each year, and the development of new strategies is needed to overcome the limitations of existing vaccines and antiviral drugs. In this study, we evaluated the antiviral potential of transgenic porcine cells and suckling mice that simultaneously expressed two short-hairpin RNA (shRNAs) targeting the conserved regions of the viral polymerase protein 3D and the non-structural protein 2B. First, two recombinant shRNA-expressing plasmids, PB-EN3D2B and PB-N3D2B, were constructed and the efficiency of the constructs for suppressing an artificial target was demonstrated in BHK-21 cells. We then integrated PB-EN3D2B into the genome of the porcine cell line IBRS-2 using the piggyBac transposon system, and stable monoclonal transgenic cell lines (MTCL) were selected. Of the 6 MTCL that were used in the antiviral assay, 3 exhibited significant resistance with suppressing ratios of more than 94% at 48 hours post-challenge (hpc) to both serotype O and serotype Asia 1 FMDV. MTCL IB-3D2B-6 displayed the strongest antiviral activity, which resulted in 100% inhibition of FMDV replication until 72 hpc. Moreover, the shRNA-expressing fragment of PB-N3D2B was integrated into the mouse genome by DNA microinjection to produce transgenic mice. When challenged with serotype O FMDV, the offspring of the transgenic mouse lines N3D2B-18 and N3D2B-81 exhibited higher survival rates of 19% to 27% relative to their non-transgenic littermates. The results suggest that these heritable shRNAs were able to suppress FMDV replication in the transgenic cell lines and suckling mice.
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NOD2 promotes renal injury by exacerbating inflammation and podocyte insulin resistance in diabetic nephropathy.
Kidney Int.
PUBLISHED: 01-16-2013
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An increasing number of clinical and animal model studies indicate that activation of the innate immune system and inflammatory mechanisms are important in the pathogenesis of diabetic nephropathy. Nucleotide-binding oligomerization domain containing 2 (NOD2), a member of the NOD-like receptor family, plays an important role in innate immune response. Here we explore the contribution of NOD2 to the pathogenesis of diabetic nephropathy and found that it was upregulated in kidney biopsies from diabetic patients and high-fat diet/streptozotocin-induced diabetic mice. Further, NOD2 deficiency ameliorated renal injury in diabetic mice. In vitro, NOD2 induced proinflammatory response and impaired insulin signaling and insulin-induced glucose uptake in podocytes. Moreover, podocytes treated with high glucose, advanced glycation end-products, tumor necrosis factor-?, or transforming growth factor-? (common detrimental factors in diabetic nephropathy) significantly increased NOD2 expression. NOD2 knockout diabetic mice were protected from the hyperglycemia-induced reduction in nephrin expression. Further, knockdown of NOD2 expression attenuated high glucose-induced nephrin downregulation in vitro, supporting an essential role of NOD2 in mediating hyperglycemia-induced podocyte dysfunction. Thus, NOD2 is one of the critical components of a signal transduction pathway that links renal injury to inflammation and podocyte insulin resistance in diabetic nephropathy.
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