The objective of this article is to investigate the effect of renin-angiotensin system inhibitors (RASIs) on intact parathyroid hormone (iPTH) levels in continuous ambulatory peritoneal dialysis (CAPD) patients.
Single-crystalline tetragonal perovskite lead titanate (PbTiO3) nanosheets with dominant (001) facets have been successfully synthesized by employing layered K2Ti6O13 nanofibers as titanium sources. The as-prepared PbTiO3 nanosheets were characterized by means of X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, and selected-area electron diffraction. In order to understand the formation mechanism of the PbTiO3 nanosheets, a series of time-dependent experiments were performed. Because of the substitution of Pb(2+) ions for K(+) ions, the TiO6 octahedral lamellas exfoliate from the layered K2Ti6O13 crystal structure. Then the exfoliated TiO6 octahedral lamellas as templates transform to lamellar PbTiO3 species by reacting with the dehydrated Pb(2+) ions. With hydrothermal treatment prolongation, the lamellar PbTiO3 species crystallize to single-crystalline PbTiO3 nanosheets. Moreover, the thickness of the synthesized single-crystalline PbTiO3 nanosheets can be tailored in the range of 10-50 nm by controlling the hydrothermal treatment time. In addition, the band gap and the optoelectronic properties of the single-crystalline PbTiO3 nanosheets are investigated by UV-vis absorption and photoluminescence.
The p-n diodes represent the most fundamental device building blocks for diverse optoelectronic functions, but are difficult to achieve in atomically thin transition metal dichalcogenides (TMDs) due to the challenges in selectively doping them into p- or n-type semiconductors. Here, we demonstrate that an atomically thin and sharp heterojunction p-n diode can be created by vertically stacking p-type monolayer tungsten diselenide (WSe2) and n-type few-layer molybdenum disulfide (MoS2). Electrical measurements of the vertically staked WSe2/MoS2 heterojunctions reveal excellent current rectification behavior with an ideality factor of 1.2. Photocurrent mapping shows rapid photoresponse over the entire overlapping region with a highest external quantum efficiency up to 12%. Electroluminescence studies show prominent band edge excitonic emission and strikingly enhanced hot-electron luminescence. A systematic investigation shows distinct layer-number dependent emission characteristics and reveals important insight about the origin of hot-electron luminescence and the nature of electron-orbital interaction in TMDs. We believe that these atomically thin heterojunction p-n diodes represent an interesting system for probing the fundamental electro-optical properties in TMDs and can open up a new pathway to novel optoelectronic devices such as atomically thin photodetectors, photovoltaics, as well as spin- and valley-polarized light emitting diodes, on-chip lasers.
Adipose tissue inflammation and perturbation of adipokine secretion may contribute to the pathogenesis of cardiovascular diseases (CVD). Lipocalin-2 (LCN2), mainly released from adipocytes, has been shown to be positively associated with CVD in cross-sectional studies. We aimed to evaluate the association of LCN2 with CVD involving a population-based cohort recruited from the Shanghai Diabetes Study.
Endoplasmic reticulum (ER) stress activates the adaptive unfolded protein response (UPR) and represents a critical mechanism that underlies metabolic dysfunctions. Fibroblast growth factor 21 (FGF21), a hormone that is predominantly secreted by the liver, exerts a broad range of effects upon the metabolism of carbohydrates and lipids. Although increased circulating levels of FGF21 have been documented in animal models and human subjects with obesity and nonalcoholic fatty liver disease, the functional interconnections between metabolic ER stress and FGF21 are incompletely understood. Here, we report that increased ER stress along with the simultaneous elevation of FGF21 expression were associated with the occurrence of nonalcoholic fatty liver disease both in diet-induced obese mice and human patients. Intraperitoneal administration of the ER stressor tunicamycin in mice resulted in hepatic steatosis, accompanied by activation of the three canonical UPR branches and increased the expression of FGF21. Furthermore, the IRE1?-XBP1 pathway of the UPR could directly activate the transcriptional expression of Fgf21. Administration of recombinant FGF21 in mice alleviated tunicamycin-induced liver steatosis, in parallel with reduced eIF2?-ATF4-CHOP signaling. Taken together, these results suggest that FGF21 is an integral physiological component of the cellular UPR program, which exerts beneficial feedback effects upon lipid metabolism through counteracting ER stress.
This study was purposed to investigate the effect of Notch signaling pathway on VEGF promoting the proliferation of rat mesenchymal stem cells (MSC). Rat MSC were cultured in vitro, and the cells in logarithmic growth phase were used for experiments. The inhibitor DAPT was used to block Notch signaling pathway, and the effect of the pathway on VEGF promoting proliferation of MSC was observed. The experiment was divided into 4 groups: control, VEGF, DAPT and VEGF+DAPT. The CCK-8 was used to assay the cells proliferation of each group, while RT-PCR was used to detect the changes of related genes (Notch1, Notch2, Flk-1, Hes-1) at mRNA levels. The results indicated that the cells survival rate MSC in DAPT group and VEGF+DAPT group was low in each time point (24 h, 48 h, 72 h), the cell number decreased, and the cells became rounded. The survival rate of MSC in VEGF group was the highest; the difference of cell survival rate was statistically significant between the groups (P < 0.01); Compared with the control group, the mRNA expression level of Notch1, Notch2 and Flk-1 in VEGF group was raised, while the expression level of Notch1 and Notch2 in DAPT group and VEGF+DAPT group come down, with statistically significant differences (P < 0.05); whereas the mRNA expression level of Hes-1 in VEGF group was down-regulated, but that in DAPT group and VEGF+DAPT group was up-regulated, and the difference was statistically significant (P < 0.05). Flk-1 mRNA level in DAPT group and VEGF+DAPT group was slightly lower, but the difference was not statistically significant (P > 0.05). It is concluded that Notch signaling pathway plays an important role in promoting the proliferation of rat MSC, treated with VEGF, however, the DAPT can weaken this effect.
A thorough understanding of needle-tissue interaction mechanics is necessary to optimize needle design, achieve robotically needle steering, and establish surgical simulation system. It is obvious that the interaction is influenced by numerous variable parameters, which are divided into three categories: needle geometries, insertion methods, and tissue characteristics. A series of experiments are performed to explore the effect of influence factors (material samples n=5 for each factor) on the insertion force. Data were collected from different biological tissues and a special tissue-equivalent phantom with similar mechanical properties, using a 1-DOF mechanical testing system instrumented with a 6-DOF force/torque (F/T) sensor. The experimental results indicate that three basic phases (deformation, insertion, and extraction phase) are existent during needle penetration. Needle diameter (0.7-3.2mm), needle tip (blunt, diamond, conical, and beveled) and bevel angle (10-85°) are turned out to have a great influence on insertion force, so do the insertion velocity (0.5-10mm/s), drive mode (robot-assisted and hand-held), and the insertion process (interrupted and continuous). Different tissues such as skin, muscle, fat, liver capsule and vessel are proved to generate various force cures, which can contribute to the judgement of the needle position and provide efficient insertion strategy.
It has been suggested that vitamin E alone or combined with other vitamins or minerals can prevent oxidative stress and slow oxidative injury-related diseases, such as cardiovascular disease and cancer. A comprehensive search of PubMed/MEDLINE, EMBASE and the Cochrane Library was performed. Relative risk was used as an effect measure to compare the intervention and control groups. A total of 33 trials were included in the meta-analysis. Neither vitamin E intake alone (RR=1.01; 95% CI, 0.97 to 1.04; p=0.77) nor vitamin E intake combined with other agents (RR=0.97; 95% CI, 0.89 to 1.06; p=0.55) was correlated with all-cause mortality. Subgroup analyses revealed that low-dose vitamin E supplementation combined with other agents is associated with a statistically significant reduction in all-cause mortality (RR=0.92; 95% CI, 0.86 to 0.98; p=0.01), and vitamin E intake combined with other agents is associated with a statistically significant reduction in mortality rates among individuals without probable or confirmed diseases (RR=0.92; 95% CI, 0.86 to 0.99; p=0.02). Neither vitamin E intake alone nor combined with other agents is associated with a reduction in all-cause mortality. But a low dose (<400 IU/d) of vitamin E combined with other agents is correlated with a reduction in all-cause mortality, and vitamin E intake combined with other agents is correlated with a reduction in the mortality rate among individuals without probable or confirmed diseases.
The aim of this study was to investigate drug release mechanisms from physical mixtures of chitosan-anionic polymers-based matrix tablets and to obtain a comprehensive understanding about release characteristics. Six types of anionic polymers (i.e., Eudragit(®) L100, sodium alginate, carrageenan, carboxymethylcellulose sodium, carbomer and xanthan gum) and two model drugs (i.e., theophylline and metoprolol succinate) with varied solubility were chosen. Texture analyzer, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were applied to better understand drug release mechanisms. In vitro release experiments were conducted in a pH-changing medium to simulate the physiological condition of the gastrointestinal tract. Interestingly, a common phenomenon was observed in all the CS-anionic polymers-based matrix tablets investigated here, that is, the inner layer of the swollen tablets was coated by CS-anionic polymer polyelectrolyte complexes (PEC)-based film formed by self-assembly. Formation of the in situ self-assembled film was further confirmed by texture analysis, DSC, and FTIR. It was further identified that properties of the film were influenced by the characteristics of anionic polymers and the physiological conditions of the gastrointestinal tract. Moreover, this novel structure could alter swelling and erosion-based release mechanisms of the tablets. In addition, drug release characteristics from CS-anionic polymer systems depended on the properties of anionic polymers and the drug solubility. In conclusion, our studies may broaden current views on cationic polymer-anionic polymer-based oral matrix tablets for extended release.
The synthesis of atomically thin transition-metal oxide nanosheets as a conceptually new class of materials is significant for the development of next-generation electronic and magnetic nanodevices but remains a fundamental chemical and physical challenge. Here, based on a "template-assisted oriented growth" strategy, we successfully synthesized half-unit-cell nanosheets of a typical transition-metal oxide ?-Fe2O3 that show robust intrinsic ferromagnetism of 0.6 ?B/atom at 100 K and remain ferromagnetic at room temperature. A unique surface structure distortion, as revealed by X-ray absorption spectroscopy, produces nonidentical Fe ion environments and induces distance fluctuation of Fe ion chains. First-principles calculations reveal that the efficient breaking of the quantum degeneracy of Fe 3d energy states activates ferromagnetic exchange interaction in these Fe(5-co)-O-Fe(6-co) ion chains. These results provide a solid design principle for tailoring the spin-exchange interactions and offer promise for future semiconductor spintronics.
Disulfide-bond A oxidoreductase-like protein (DsbA-L) possesses beneficial effects such as promoting adiponectin multimerization and stability, increasing insulin sensitivity, and enhancing energy metabolism. The expression level of DsbA-L is negatively correlated with obesity in mice and humans, but the underlying mechanisms remain unknown. To address this question, we generated reporter gene constructs containing the promoter sequence of the mouse DsbA-L gene. Deletion analysis showed that the proximal promoter of mouse DsbA-L is located between -186 and -34 bp relative to the transcription start site. In silico analysis identified a putative Sp1 transcription factor binding site in the first intron of the DsbA-L gene. Electrophoretic mobility shift assay and chromatin immunoprecipitation analysis indicated that Sp1 bound to this intron region in vitro and in intact cells. Overexpression of Sp1 or suppressing Sp1 expression by siRNA reduced or increased DsbA-L promoter activity, respectively. The binding activity of Sp1 was gradually decreased during 3T3-L1 cell differentiation and was significantly increased in adipose tissues of obese mice. Our results identify Sp1 as an inhibitor of DsbA-L gene transcription, and the Sp1-mediated inhibition of DsbA-L gene expression may provide a mechanism underlying obesity-induced adiponectin downregulation and insulin resistance.
A brushlike PbTiO3 (PTO)/ZnO nanocomposite with ZnO nanowires (NWs) grown epitaxially on the surface of single-crystal ferroelectric tetragonal PTO NWs is successfully fabricated onto a flexible substrate via a two-step hydrothermal process. In this nanocomposite, a ZnO NW grew along  on the (101) plane of the core PTO NW with a lattice mismatch of 1.06% to form an effective ferroelectric/semiconductor interface. It is found that the ultraviolet photoluminescence emission of the nanocomposite could be easily tuned by its bending curvatures at room temperature. This intriguing phenomenon can be understood by the bending-induced polarization field from the PTO NW, which could reduce the bending degree of the energy band of the ZnO NWs through the interface. Throughthe design of an effective interface, this kind of ferroelectric/semiconductor nanocomposite may find potential applications in sensor and piezophotonic nanodevices.
Forkhead box P3(+) (Foxp3(+)) regulatory T cells (Tregs) are crucial for peripheral tolerance. During inflammation, steady Foxp3 expression in Tregs is essential for maintaining their lineage identity and suppressive function. However, the molecular machinery governing Tregs' resilience to inflammation-induced Foxp3 destabilization remains elusive. Here, we demonstrate that methyl-CpG binding protein 2 (MeCP2), an eminent epigenetic regulator known primarily as the etiological factor of Rett syndrome, is critical to sustain Foxp3 expression in Tregs during inflammation. In response to inflammatory stimuli, MeCP2 is specifically recruited to the Conserved Non-Coding sequence 2 region of the foxp3 locus, where it collaborates with cAMP responsive element binding protein 1 to promote local histone H3 acetylation, thereby counteracting inflammation-induced epigenetic silencing of foxp3. Consequently, Treg-specific deletion of MeCP2 causes spontaneous immune activation in mice and failure in protection against autoimmunity. Furthermore, we demonstrate that Foxp3 expression in MeCP2-deficient Tregs diminishes with time, resulting in their failure to suppress effector T-cell-mediated colitis. Thus, MeCP2 serves as a critical safeguard that confers Tregs with resilience against inflammation.
The goal of this study was to assess the association between endometrial thickness on the chorionic gonadotropin (hCG) day and in vitro fertilization and embryo transfer (IVF-ET) outcome in normal responders after GnRH antagonist administration.
To investigate the effect of oxygen glucose deprivation (OGD) on the glutamate release and the role of connexin 43 (Cx43) hemichannels in the OGD-induced glutamate release in primary cultured astrocytes.
Two-dimensional layered materials, such as molybdenum disulfide, are emerging as an exciting material system for future electronics due to their unique electronic properties and atomically thin geometry. Here we report a systematic investigation of MoS2 transistors with optimized contact and device geometry, to achieve self-aligned devices with performance including an intrinsic gain over 30, an intrinsic cut-off frequency fT up to 42?GHz and a maximum oscillation frequency fMAX up to 50?GHz, exceeding the reported values for MoS2 transistors to date (fT~0.9?GHz, fMAX~1?GHz). Our results show that logic inverters or radio frequency amplifiers can be formed by integrating multiple MoS2 transistors on quartz or flexible substrates with voltage gain in the gigahertz regime. This study demonstrates the potential of two-dimensional layered semiconductors for high-speed flexible electronics.
Airway remodeling contributes to increased mortality in asthma. We have reported that triptolide can inhibit airway remodeling in a mouse asthma model. In this study, we aimed to investigate the effect of triptolide on airway smooth muscle cells (ASMCs) proliferation, migration and the possible mechanism.
There is evidence that astroglial connexin43 (Cx43) in the supraoptic nucleus (SON) is required for the hyperosmolarity?induced increase in Fos protein expression in magnocellular neurosecretory cells (MNCs). In the present study, the role of astroglial Cx43 in the synthesis and release of vasopressin (VP) by MNCs in the SON subjected to hyperosmotic stimulus was examined. The results revealed that the VP levels in the SON and plasma were increased following acute hyperosmotic stimulus. Treatment of MNCs with Cx43?specific antisense oligodeoxynucleotides (ASODN), which temporarily reduced Cx43 protein production, limited the VP synthesis and release induced by a hyperosmotic stimulus. Similarly, the addition of gap junction and Cx43 hemichannel blockers also attenuated the VP synthesis and release induced by an acute hyperosmotic stimulus. A high extracellular [Ca2+]([Ca2+]o) has been demonstrated to reduce the gap junction activity or opening probability of Cx54 hemichannels. Notably, it was identified that high [Ca2+]o attenuated the VP synthesis and release induced by acute hyperosmotic stimulus, while low [Ca2+]o had a weak or no effect. These results suggested that Cx43 participates in the VP synthesis and release induced by hyperosmotic stimulation in the SON.
Cancer stem-like cells/cancer initiating cells (CSCs/CICs) are considered to represent a small population of cancer cells that is resistant to conventional cancer treatments and responsible for tumor recurrence and metastasis. The aim of the present study was to establish CSC/CIC-targeting immunotherapy. In this study, we found that Annexin A3 (ANXA3) was preferentially expressed in CSCs/CICs derived from hepatocellular carcinoma (HCC) cells compared to non-CSCs/CICs. In HCC samples, high levels of ANXA3 correlated with expansion of CD133(+) tumor cells representing CSCs/CICs in HCC; the combination of high levels of ANXA3 and CD133 was associated with progression of HCC. Overexpression of ANXA3 increased the proportion of CD133(+) cells, enhancing their tumorigenicity. On the contrary, knockdown of ANXA3 decreased CD133(+) cells and inhibited tumorigenicity. The mechanistic study revealed that ANXA3-mediated maintenance of HCC CSCs/CICs activity was likely involved with the HIF1A/Notch pathway. Using ANXA3 as a target, ANXA3-transfected dendritic cells (DCs) could induce more functionally active T cells and these effector T cells could superiorly kill CD133(+) HCC CSCs/CICs in vitro and in vivo. Taken together, our findings suggest that ANXA3 plays a role in HCC CSC/CIC maintenance, and that ANXA3 may represent a potential CSC/CIC-specific therapeutic target for improving the treatment of HCC. Stem Cells 2014.
RNA interference (RNAi) is an ancient intra-cellular mechanism that regulates gene expression and cell function. Large-scale gene silencing using RNAi high-throughput screening (HTS) has opened an exciting frontier to systematically study gene function in mammalian cells. This approach enables researchers to identify gene function in a given biological context and will provide considerable novel insight. Here, we review RNAi HTS strategies and applications using case studies in cancer biology and virology.
CD8+ cytotoxic T lymphocytes (CTLs) have potent antitumor activity and therefore are leading candidates for use in tumor immunotherapy. The application of CTLs for clinical use has been limited by the susceptibility of ex vivo-expanded CTLs to become dysfunctional in response to immunosuppressive microenvironments. Here, we developed a microRNA-targeting (miRNA-targeting) approach that augments CTL cytotoxicity and preserves immunocompetence. Specifically, we screened for miRNAs that modulate cytotoxicity and identified miR-23a as a strong functional repressor of the transcription factor BLIMP-1, which promotes CTL cytotoxicity and effector cell differentiation. In a cohort of advanced lung cancer patients, miR-23a was upregulated in tumor-infiltrating CTLs, and expression correlated with impaired antitumor potential of patient CTLs. We determined that tumor-derived TGF-? directly suppresses CTL immune function by elevating miR-23a and downregulating BLIMP-1. Functional blocking of miR-23a in human CTLs enhanced granzyme B expression, and in mice with established tumors, immunotherapy with just a small number of tumor-specific CTLs in which miR-23a was inhibited robustly hindered tumor progression. Together, our findings provide a miRNA-based strategy that subverts the immunosuppression of CTLs that is often observed during adoptive cell transfer tumor immunotherapy and identify a TGF-?-mediated tumor immune-evasion pathway.
In order to enhance its interaction efficiency with biomacromolecules for the usage as a therapeutic agent, we have conjugated morin, an antioxidant activity and anti-tumor drug, with citrate-coated Au nanoparticles (M-C-AuNPs). M-C-AuNPs were prepared by reducing chloroauric acid using trisodium citrate in the boiling condition, and the resulted M-C-AuNPs were characterized by UV-vis absorption spectroscopy, Transmission Electron Microscopy (TEM), X-ray diffraction (XRD) and FTIR analysis. In this article, UV-vis absorption spectroscopy in combination with fluorescence spectroscopy, and circular dichroism (CD) spectroscopy were employed to investigate the interactions between M-C-AuNPs and bovine serum albumin (BSA), C-AuNPs and BSA in a phosphate buffer at pH 7.4. By comparing the quenching constant KSV, effective quenching constant Ka, binding constant Kb and the number of binding sites n, it is clearly suggested that M-C-AuNPs could enhance the binding force of morin with BSA, which would pave the way for the design of nanotherapeutic agents with improved functionality.
Dysfunctional endothelium contributes to more diseases than any other tissue in the body. Small interfering RNAs (siRNAs) can help in the study and treatment of endothelial cells in vivo by durably silencing multiple genes simultaneously, but efficient siRNA delivery has so far remained challenging. Here, we show that polymeric nanoparticles made of low-molecular-weight polyamines and lipids can deliver siRNA to endothelial cells with high efficiency, thereby facilitating the simultaneous silencing of multiple endothelial genes in vivo. Unlike lipid or lipid-like nanoparticles, this formulation does not significantly reduce gene expression in hepatocytes or immune cells even at the dosage necessary for endothelial gene silencing. These nanoparticles mediate the most durable non-liver silencing reported so far and facilitate the delivery of siRNAs that modify endothelial function in mouse models of vascular permeability, emphysema, primary tumour growth and metastasis.
Activating mutations in KRAS are among the most frequent events in diverse human carcinomas and are particularly prominent in human pancreatic ductal adenocarcinoma (PDAC). An inducible Kras(G12D)-driven mouse model of PDAC has established a critical role for sustained Kras(G12D) expression in tumor maintenance, providing a model to determine the potential for and the underlying mechanisms of Kras(G12D)-independent PDAC recurrence. Here, we show that some tumors undergo spontaneous relapse and are devoid of Kras(G12D) expression and downstream canonical MAPK signaling and instead acquire amplification and overexpression of the transcriptional coactivator Yap1. Functional studies established the role of Yap1 and the transcriptional factor Tead2 in driving Kras(G12D)-independent tumor maintenance. The Yap1/Tead2 complex acts cooperatively with E2F transcription factors to activate a cell cycle and DNA replication program. Our studies, along with corroborating evidence from human PDAC models, portend a novel mechanism of escape from oncogenic Kras addiction in PDAC.
The miR-17-92 cluster regulates a broad spectrum of biological processes of T cell immunity. This cluster was found to facilitate T cell proliferation, enhance antitumor activities and promote T cell-dependent antibody responses. However, little is known about the role of this miRNA cluster in the development of autoimmune diseases. Multiple sclerosis is a neuro-destructive autoimmune disease caused by the pathogenicity of TH17 cells, whose differentiation is tightly controlled by a variety of transcriptional and post-transcriptional regulators. Our study unveils the critical role of miR-17-92 in TH17 differentiation: T cell-specific miR-17-92 deficiency reduced TH17 differentiation and ameliorated experimental autoimmune encephalomyelitis (EAE) symptoms. We demonstrated that miR-17 and miR-19b are the two miRNAs in this cluster responsible for promoting TH17 responses. MiR-19b represses the expression of Phosphatase and Tensin Homology (PTEN), thereby augmenting the PI3K-AKT-mTOR axis essential for proper TH17 differentiation. Meanwhile, miR-17 enhances TH17 polarization by inhibiting a novel target, Ikaros Family Zinc Finger 4 (IKZF4). By establishing the miR-17-92 cluster as a key driver of TH17 responses, our data identify this miRNA cluster as a potential therapeutic target for the clinical intervention of multiple sclerosis.
Methyl CpG binding protein 2 (MeCP2) is an X-linked, multifunctional epigenetic regulator that is best known for its role in the neurological disorder Rett syndrome; however, it is also linked to multiple autoimmune disorders. We examined a potential role for MeCP2 in regulating the responses of CD4+ T cells to stimulation with antigen. MeCP2 was indispensable for the differentiation of naïve CD4+ T cells into T helper type 1 (T(H)1) and T(H)17 cells and for T(H)1- or T(H)17-mediated pathologies in vitro and in vivo. Loss of MeCP2 in CD4+ T cells impaired the expression of the microRNA (miR) miR-124 and consequently relieved miR-124-mediated repression of the translation of suppressor of cytokine signaling 5 (Socs5) mRNA. The resulting accumulation of SOCS5 inhibited the cytokine-dependent activation of signal transducer and activator of transcription 1 (STAT1) and STAT3, which are necessary for the differentiation of T(H)1 and T(H)17 cells, respectively. Upon silencing of MeCP2, primary neurons and astrocytes also failed to respond properly to STAT3-dependent signaling stimulated by neurotrophic factors. Together, these findings suggest that the regulation of STAT3 signaling may represent a common etiology underpinning the roles of MeCP2 in both the nervous and immune systems.
Infrasonic noise/infrasound is a type of environmental noise that threatens public health as a nonspecific biological stressor. Glutamate-related excitotoxicity is thought to be responsible for infrasound-induced impairment of learning and memory. In addition to neurons, astrocytes are also capable of releasing glutamate. In the present study, to identify the effect of infrasound on astroglial glutamate release, cultured astrocytes were exposed to infrasound at 16 Hz, 130 dB for different times. We found that infrasound exposure caused a significant increase in glutamate levels in the extracellular fluid. Moreover, blocking the connexin43 (Cx43) hemichannel or gap junction, decreasing the probability of Cx43 being open or inhibiting of Cx43 expression blocked this increase. The results suggest that glutamate release by Cx43 hemichannels/gap junctions is involved in the response of cultured astrocytes to infrasound.
BackgroundGalectin-3, a member of the beta-galactoside-binding lectin family, is a multifunctional protein with various biological functions, including the proliferation and differentiation of tumor cells, angiogenesis, cancer progression, and metastasis. We aimed to clarify if expression of galectin-3 is related to the clinicopathological characteristics and prognosis of hepatocellular carcinoma (HCC) patients, and to explore the possible mechanisms of galectin-3 in hepatocellular carcinoma.MethodsFirst, we investigated galectin-3 mRNA and protein expression by using RT-PCR and Western blotting. Second, tissues from 165 HCC patients were used to evaluate clinicopathological characteristics and prognosis through immunohistochemical analyses. Furthermore, the functions of galectin-3 were analyzed with respect to the proliferation, cell cycle,apoptosis, migration, and invasion of HCC cell lines. Finally, we analyzed galectin-3 expression and micro-vessel density (MVD) by immunohistochemistry (IHC) to find its correlation with angiogenesis in Hepatocellular Carcinoma. Flow cytometer was used to explore apoptosis and Western-blot was used to detect the pathway proteins of apoptosis.ResultsGalectin-3 showed high expression at the mRNA and protein levels in HCC cancer tissues and cell lines. Clinicopathological analyses revealed that increased expression of galectin-3 in tumors was closely associated with a poor prognosis. Galectin-3 knockdown by siRNA significantly inhibited cell growth, migration, and invasion, and induced apoptosis in HCC cells in vitro, whereas galectin-3 overexpression promoted cell growth, migration, and invasion. Correlation analysis of galectin-3 expression and micro-vessel density (MVD) showed that galectin-3 expression in tumor cells stimulates angiogenesis. The observed regulation of cell apoptosis was accompanied by the galectin-3-mediated modulation of caspase3 signaling pathways in HCC cells.ConclusionsThese data suggest that galectin-3 plays an important part in HCC progression and may serve as a prognostic factor for HCC.
Although the mammalian IRE1?-XBP1 branch of the cellular unfolded protein response has been implicated in glucose and lipid metabolism, the exact metabolic role of IRE1? signalling in vivo remains poorly understood. Here we show that hepatic IRE1? functions as a nutrient sensor that regulates the metabolic adaptation to fasting. We find that prolonged deprivation of food or consumption of a ketogenic diet activates the IRE1?-XBP1 pathway in mouse livers. Hepatocyte-specific abrogation of Ire1? results in impairment of fatty acid ?-oxidation and ketogenesis in the liver under chronic fasting or ketogenic conditions, leading to hepatosteatosis; liver-specific restoration of XBP1s reverses the defects in IRE1? null mice. XBP1s directly binds to and activates the promoter of PPAR?, the master regulator of starvation responses. Hence, our results demonstrate that hepatic IRE1? promotes the adaptive shift of fuel utilization during starvation by stimulating mitochondrial ?-oxidation and ketogenesis through the XBP1s-PPAR? axis.
The aim of the present study was to investigate the mutational characteristics of drug?resistant genetic mutations in the katG gene to isoniazid (INH) in multi?drug resistant Mycobacterium tuberculosis (MTB) L?form among patients with pneumoconiosis complicated with tuberculosis (TB), in order to reduce the occurrence of drug resistance in patients, and gain further insight into the mechanisms underlying drug resistance in MDR?TB L?form. A total of 114 clinically isolated strains of MTB L?forms were collected. The MDR?TB L?forms were identified using a conventional antimicrobial susceptibility test (AST). The DNA genomes were extracted, the target genes were amplified by polymerase chain reaction technology and the hotspot mutational regions in the katG gene were analyzed by direct sequencing. The results of AST analysis demonstrated that there were 31 strains of MDR?TB L?forms in 114 clinical isolates. The mutation rate of katG was 61.29% (19/31) in INH?resistant isolates, mainly concentrated in codon 315 (Ser315Thr, 48.39% and Ser315Asn, 9.68%) and 431 (Ala431Val, 3.23%). Base substitutions were identified, however, no multisite mutations were found. No mutations in katG were identified in 10 INH?sensitive strains that were randomly selected. INH?resistance was more severe in MDR?TB L?form isolates among patients with pneumoconiosis complicated with TB. The substitution of highly conserved amino acids encoded by the katG gene resulted in the molecular mechanisms responsible for INH resistance in MDR?TB L?form isolates. It was also verified that the katG gene was in diversiform. The katG Ser315Thr mutation is one of the main causes of resistance to INH in MDR?TB L-form isolates.
Agonist-activated ?-opioid receptor (OPRM1) undergoes robust receptor phosphorylation by G protein-coupled receptor kinases and subsequent ?-arrestin recruitment, triggering receptor internalization and desensitization. Morphine, a widely prescribed opioid, induces receptor phosphorylation inefficiently. Previously we reported that FK506 binding protein 12 (FKBP12) specifically interacts with OPRM1 and such interaction attenuates receptor phosphorylation and facilitates morphine-induced recruitment and activation of protein kinase C. In the current study, we demonstrated that the association of FKBP12 with OPRM1 also affects morphine-induced receptor internalization and G protein-dependent adenylyl cyclase desensitization. Morphine induced faster receptor internalization and adenylyl cyclase desensitization in cells expressing OPRM1 with Pro(353) mutated to Ala (OPRM1P353A), which does not interact with FKBP12, or in the presence of FK506 which dissociates the receptor-FKBP12 interaction. Furthermore, knockdown of cellular FKBP12 level by siRNA accelerated morphine-induced receptor internalization and adenylyl cyclase desensitization. Our study further demonstrated that peptidyl prolyl cis-trans isomerase activity of FKBP12 probably plays a role in inhibition of receptor phosphorylation. In the view that internalized receptor recycles and thus counteracts the development of analgesic tolerance, receptor's association with FKBP12 could also contribute to the development of morphine tolerance through modulation of receptor trafficking.
Aspergillus tracheobronchitis (ATB) is considered as an unusual form of invasive aspergillosis and has a fatal outcome. There is little current information on several aspects of chronic obstructive pulmonary diseases (COPD) complicated by ATB, the frequency of which is expected to increase in the coming years. In a prospective study of invasive bronchial-pulmonary aspergillosis (IBPA) in a critically ill COPD population, three proven cases of ATB were identified. The three new cases, combined with eight previously reported cases of COPD with ATB over a 30-year period (1983-2013), were analysed. Among 153 critically ill COPD patients admitted to the ICU, eight cases were complicated by ATB [23.5% of IBPA (8 of 34); and 5.2% of COPD (8 of 153)], and three cases were finally diagnosed as proven ATB by histopathological findings. Among the three new cases reported and the eight published cases, the overall mortality rate was 72.7% (8 of 11 cases), with a median of 11.5 days (range, 7-27 days) between admission to death. The mortality rate was significantly higher in patients with invasive pulmonary aspergillosis (IPA) [100% (8 of 8 patients)] than in patients without parenchyma invasion [0% (0 of 3 patient), P = 0.006]. Seven patients (77.8%) received systemic corticosteroid therapy and three patients (33.3%) inhaled corticosteroids before diagnosis with ATB. Dyspnoea resistant to corticosteroids (77.8%) was the most frequent symptom. The radiological manifestations progressed rapidly in three patients (75%) who had normal chest X-rays (CXRs) at admission. Pseudomembranous lesions were the most frequent form (54.5%) observed by bronchoscopy. Aspergillus fumigatus was the most frequently isolated pathogen (40%). ATB is an uncommon cause of exacerbation in approximately 5% of critically ill COPD patients admitted to the ICU, and may progress rapidly to IPA with a high mortality rate. Dyspnoea resistant to corticosteroids and appropriate antibiotics with a negative CXR should raise the suspicion of ATB. Early diagnosis of ATB is based on bronchoscopic examination and proven diagnosis maybe safely established with a bronchial mucous biopsy.
The aim of the present study was to investigate the mutational characteristics of the drug?resistant Mycobacterium tuberculosis L?form of the rpoB gene isolated from patients with pneumoconiosis complicated by tuberculosis, in order to reduce the occurrence of the drug resistance of patients and gain a more complete information on the resistance of the Mycobacterium tuberculosis L?form. A total of 42 clinically isolated strains of Mycobacterium tuberculosis L?form were collected, including 31 drug?resistant strains. The genomic DNA was extracted, then the target genes were amplified by polymerase chain reaction and the hot mutational regions of the rpoB gene were analyzed by direct sequencing. The results revealed that no rpoB gene mutation was present in 11 rifampicin (RFP)?sensitive strains, while conformational changes were identified in 31 RFP?resistant strains. The mutation rate was 93.55% (29/31) in the resistant strains, and was frequently concentrated in codons 531 (51.61%; 16/31) and 526 (32.26%; 10/31), mainly occurring by case substitutions, including 27 unit point mutations and two two?point mutations. The novel mutation identified in codon 516 had not been previously reported. The substitution of highly?conserved amino acids encoded by the rpoB gene resulted in the molecular mechanism responsible for RFP resistance in the Mycobacterium tuberculosis L?form. This also demonstrated that the rpoB gene is diversiform.
This study was conducted was to detect vascular endothelial growth factor (VEGF) levels in peripheral blood of patients with pregnancy-induced hypertension (PIH) syndrome and to investigate VEGF correlation with PIH occurrence.
The integration of multiple synergistic catalytic systems can enable the creation of biocompatible enzymatic mimics for cascading reactions under physiologically relevant conditions. Here we report the design of a graphene-haemin-glucose oxidase conjugate as a tandem catalyst, in which graphene functions as a unique support to integrate molecular catalyst haemin and enzymatic catalyst glucose oxidase for biomimetic generation of antithrombotic species. Monomeric haemin can be conjugated with graphene through ?-? interactions to function as an effective catalyst for the oxidation of endogenous L-arginine by hydrogen peroxide. Furthermore, glucose oxidase can be covalently linked onto graphene for local generation of hydrogen peroxide through the oxidation of blood glucose. Thus, the integrated graphene-haemin-glucose oxidase catalysts can readily enable the continuous generation of nitroxyl, an antithrombotic species, from physiologically abundant glucose and L-arginine. Finally, we demonstrate that the conjugates can be embedded within polyurethane to create a long-lasting antithrombotic coating for blood-contacting biomedical devices.
Some organic cage molecules have structures with protected, internal pore volume that cannot be in-filled, irrespective of the solid-state packing mode: that is, they are intrinsically porous. Amorphous packings can give higher pore volumes than crystalline packings for these materials, but the precise nature of this additional porosity is hard to understand for disordered solids that cannot be characterized by X-ray diffraction. We describe here a computational methodology for generating structural models of amorphous porous organic cages that are consistent with experimental data. Molecular dynamics simulations rationalize the observed gas selectivity in these amorphous solids and lead to insights regarding self-diffusivities, gas diffusion trajectories, and gas hopping mechanisms. These methods might be suitable for the de novo design of new amorphous porous solids for specific applications, where "rigid host" approximations are not applicable.
Both the vibrational and structural properties of coronene have been investigated upon compression up to 30.5 GPa at room temperature by a combination of Raman scattering and synchrotron x-ray diffraction measurements. The spectroscopic and crystallographic results demonstrate that two pressure-induced structural phase transitions take place at 1.5 GPa and 12.2 GPa where the high-pressure phases are identified as monoclinic and orthorhombic crystal structures with space groups of P2/m and Pmmm, respectively. A kink in the slope of the cell parameters as a function of pressure is associated with the disappearance of several internal Raman modes, which suggests the existence of structural distortions or reorganizations at approximately 6.0 GPa. Above 17.1 GPa, almost no evidence of crystallinity can be observed, indicating a possible transformation of coronene into an amorphous phase.
Protein kinase C (PKC) activation plays an important role in morphine-induced ?-opioid receptor (OPRM1) desensitization and tolerance development. It was recently shown that receptor phosphorylation by G protein-coupled receptor kinase regulates agonist-dependent selective signaling and that inefficient phosphorylation of OPRM1 leads to PKC? activation and subsequent responses. Here, we demonstrate that such receptor phosphorylation and PKC? activation can be modulated by FK506-binding protein 12 (FKBP12). Using a yeast two-hybrid screen, FKBP12 was identified as specifically interacting with OPRM1 at the Pro(353) residue. In human embryonic kidney 293 cells expressing OPRM1, the association of FKBP12 with OPRM1 decreased the agonist-induced receptor phosphorylation at Ser(375). The morphine-induced PKC? activation and the recruitment of PKC? to the OPRM1 signaling complex were attenuated both by FKBP12 short interfering RNA (siRNA) treatment and in cells expressing OPRM1 with a P353A mutation (OPRM1P353A), which leads to diminished activation of PKC-dependent extracellular signal-regulated kinases. Meanwhile, the overexpression of FKBP12 enabled etorphine to activate PKC?. Further analysis of the receptor complex demonstrated that morphine treatment enhanced the association of FKBP12 and calcineurin with the receptor. The blockade of the FKBP12 association with the receptor by the siRNA-mediated knockdown of endogenous FKBP12 or the mutation of Pro(353) to Ala resulted in a reduction in PKC? and calcineurin recruitment to the receptor signaling complex. The receptor-associated calcineurin modulates OPRM1 phosphorylation, as demonstrated by the ability of the calcineurin autoinhibitory peptide to increase the receptor phosphorylation. Thus, the association of FKBP12 with OPRM1 attenuates the phosphorylation of the receptor and triggers the recruitment and activation of PKC?.
Coupling CE-based separation techniques to MS creates a powerful platform for analysis of a wide range of biomolecules from complex samples because it combines the high separation efficiency of CE and the sensitivity and selectivity of MS detection. ESI and MALDI, as the most common soft ionization techniques employed for CE and MS coupling, offer distinct advantages for biomolecular characterization. This review is focused primarily on technological advances in combining CE and chip-based CE with ESI and MALDI-MS detection in the past five years. Selected applications in the analyses of metabolites, peptides, and proteins with recently developed CE-MS platforms are also highlighted.
The objective of this research is to investigate the potential role of lipoxin A4 in preventing paracetamol (PCM)-induced hepatic injury. One hundred male New Zealand white rabbits were randomly divided into control group, PCM group, N-acetylcysteine (NAC) group, lipoxin A4 (LXA4) group, and LXA4 + NAC group. The rabbits were assigned to receive 300 mg/kg weight PCM in 0.9 % saline or equivalent volume of saline via gastric lavage. LXA4 (1.5 ?g/kg) and equivalent volume of 2 % ethanol were separately given to the rabbits in LXA4-treated and PCM groups 24 h after PCM administration. Meanwhile, the rabbits in the NAC-treated groups received a loading dose of 140 mg/kg of N-acetylcysteine. The blood samples and liver tissue were collected for biochemical and histological evaluation 36 h after paracetamol administration. The administration of LXA4 24 h after paracetamol poisoning resulted in significant improvement in hepatic injury as represented by decrease of hepatocellular enzyme release and attenuation of hepatocyte apoptosis and necrosis. In LXA4-treated groups, the expression of TNF-? was significantly lower than those in PCM and NAC groups (p < 0.05). In contrast, the level of IL-10 was significantly higher than PCM and NAC groups (p < 0.05). Moreover, the expressions of NF-?B p65 in PCM and NAC groups were significantly increased compared with those of LXA4-treated groups and control group (respectively, p < 0.05 and p < 0.01). LXA4-treated groups also showed significantly higher survival rates. Lipoxin A4 significantly mitigates paracetamol-induced hepatic injury, in which anti-inflammation effect may play an important role, leading to hepatic apoptosis and necrosis.
A glucose-responsive closed-loop insulin delivery system represents the ideal treatment of type 1 diabetes mellitus. In this study, we develop uniform injectable microgels for controlled glucose-responsive release of insulin. Monodisperse microgels (256 ± 18 ?m), consisting of a pH-responsive chitosan matrix, enzyme nanocapsules, and recombinant human insulin, were fabricated through a one-step electrospray procedure. Glucose-specific enzymes were covalently encapsulated into the nanocapsules to improve enzymatic stability by protecting from denaturation and immunogenicity as well as to minimize loss due to diffusion from the matrix. The microgel system swelled when subjected to hyperglycemic conditions, as a result of the enzymatic conversion of glucose into gluconic acid and protonation of the chitosan network. Acting as a self-regulating valve system, microgels were adjusted to release insulin at basal release rates under normoglycemic conditions and at higher rates under hyperglycemic conditions. Finally, we demonstrated that these microgels with enzyme nanocapsules facilitate insulin release and result in a reduction of blood glucose levels in a mouse model of type 1 diabetes.
Mumps commonly affects children 5-9 yr of age, and can lead to permanent adult sterility in certain cases. However, the etiology of this long-term effect remains unclear. Mumps infection results in progressive degeneration of the seminiferous epithelium and, occasionally, Sertoli cell-only syndrome. Thus, the remaining Sertoli cells may be critical to spermatogenesis recovery after orchitis healing. Here, we report that the protein farnesylation/geranylgeranylation balance is critical for patients fertility. The expression of geranylgeranyl diphosphate synthase 1 (GGPPS) was decreased due to elevated promoter methylation in the testes of infertile patients with mumps infection history. When we deleted GGPPS in mouse Sertoli cells, these cells remained intact, whereas the adjacent spermatogonia significantly decreased after the fifth postnatal day. The proinflammatory MAPK and NF-?B signaling pathways were constitutively activated in GGPPS(-/-) Sertoli cells due to the enhanced farnesylation of H-Ras. GGPPS(-/-) Sertoli cells secreted an array of cytokines to stimulate spermatogonia apoptosis, and chemokines to induce macrophage invasion into the seminiferous tubules. Invaded macrophages further blocked spermatogonia development, resulting in a long-term effect through to adulthood. Notably, this defect could be rescued by GGPP administration in EMCV-challenged mice. Our results suggest a novel mechanism by which mumps infection during childhood results in adult sterility.
Maintaining active growth and effective immune responses is often costly for a living organism to survive. Fine-tuning the shared cross-regulators is crucial for metazoans and plants to make a trade-off between growth and immunity. The Arabidopsis regulatory receptor-like kinase BAK1 complexes with the receptor kinases FLS2 in bacterial flagellin-triggered immunity and BRI1 in brassinosteroid (BR)-mediated growth. BR homeostasis and signaling unidirectionally modulate FLS2-mediated immune responses at multiple levels. We have shown previously that BIK1, a receptor-like cytoplasmic kinase, is directly phosphorylated by BAK1 and associates with FLS2/BAK1 complex in transducing flagellin signaling. In contrast to its positive role in plant immunity, we report here that BIK1 acts as a negative regulator in BR signaling. The bik1 mutant displays various BR hypersensitive phenotypes accompanied with increased accumulation of de-phosphorylated BES1 proteins and transcriptional regulation of BZR1 and BES1 target genes. BIK1 associates with BRI1, and is released from BRI1 receptor upon BR treatment, which is reminiscent of FLS2-BIK1 complex dynamics in flagellin signaling. The ligand-induced release of BIK1 from receptor complexes is associated with BIK1 phosphorylation. However, in contrast to BAK1-dependent FLS2-BIK1 dissociation, BAK1 is dispensable for BRI1-BIK1 dissociation. Unlike FLS2 signaling which depends on BAK1 to phosphorylate BIK1, BRI1 directly phosphorylates BIK1 to transduce BR signaling. Thus, BIK1 relays the signaling in plant immunity and BR-mediated growth via distinct phosphorylation by BAK1 and BRI1, respectively. Our studies indicate that BIK1 mediates inverse functions in plant immunity and development via dynamic association with specific receptor complexes and differential phosphorylation events.
Magnetic resonance imaging (MRI) combined with robotic assistance has the potential to improve on clinical outcomes of biopsy and local treatment of prostate cancer. This paper introduces a pneumatically actuated surgical robotic system for prostatic interventions under MRI guidance.
Previous research has established that people can implicitly learn chunks, which (in terms of formal language theory) do not require a memory buffer to process. The present study explores the implicit learning of nonlocal dependencies generated by higher than finite-state grammars, specifically, Chinese tonal retrogrades (i.e. centre embeddings generated from a context-free grammar) and inversions (i.e. cross-serial dependencies generated from a mildly context-sensitive grammar), which do require buffers (for example, last in-first out and first in-first out, respectively). People were asked to listen to and memorize artificial poetry instantiating one of the two grammars; after this training phase, people were informed of the existence of rules and asked to classify new poems, while providing attributions of the basis of their judgments. People acquired unconscious structural knowledge of both tonal retrogrades and inversions. Moreover, inversions were implicitly learnt more easily than retrogrades constraining the nature of the memory buffer in computational models of implicit learning.
The essential oil from Gaillardia pulchella Foug. flowers was obtained by hydrodistillation and its chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS). Twenty-eight compounds representing 92.63% of the essential oil were identified, of which the most prominent were n-Hexadecanoic acid (26.90%), Phytol (7.58%) and Cyclopropaneoctanoic acid, 2-[[2-[(2-ethylcyclopropyl) methyl] cyclopropyl] methyl]-, methyl ester (6.73%). Meanwhile, antioxidant activity of the essential oil was tested. The essential oil showed certain antioxidant activity in 1,1-diphenyl-2-picrylhydrazyl (DPPH) with an EC?? of 70.95 ?g/ml. This is the first report on the essential oil of this particular species. Its bioactivities warrant further studies.
By inhibiting target gene expression, microRNAs (miRNAs) play major roles in various physiological and pathological processes. miR-146a, a miRNA induced upon lipopolysaccharide (LPS) stimulation and virus infection, is also highly expressed in patients with immune disorders such as rheumatoid arthritis, Sjögrens syndrome, and psoriasis. Whether the high level of miR-146a contributes to any of these pathogenesis-related processes remains unknown. To elucidate the function of miR-146a in vivo, we generated a transgenic (TG) mouse line overexpressing miR-146a. Starting at an early age, these TG mice developed spontaneous immune disorders that mimicked human autoimmune lymphoproliferative syndrome (ALPS) with distinct manifestations, including enlarged spleens and lymph nodes, inflammatory infiltration in the livers and lungs, increased levels of double-negative T cells in peripheral blood, and increased serum immunoglobulin G levels. Moreover, with the adoptive transfer approach, we found that the B-cell population was the major etiological factor and that the expression of Fas, a direct target of miR-146a, was significantly dampened in TG germinal center B cells. These results indicate that miR-146a may be involved in the pathogenesis of ALPS by targeting Fas and may therefore serve as a novel therapeutic target.
The precision of orientation to target placement during invasive therapy is mainly influenced by tool-tissue interaction. In this study, we aim to investigate a transparent Poly (vinyl alcohol) (PVA) hydrogel as tissue-equivalent material which is used in accurate surgical insertion research. The PVA hydrogel with specified formula was prepared by means of physical and chemical crosslink. The effects of chemical composition and synthesis technique on the biomechanical property, density and micro-structure morphology of PVA materials have been investigated in detail. It can be concluded that when PVA concentration is 8 g/dl, the NaCl concentration is 4 wt.%, with mix water/DMSO solvent, prepared under 7 freeze/thaw cycles, the material has the most similar properties with kidney tissue. Experimental results demonstrate that this tissue-equivalent material could be used in the ex vivo insertion accuracy test for robot-assisted percutaneous intervention and surgical training in minimally invasive surgery (MIS).
Amniotic fluid-derived mesenchymal stem cells (AF-MSC) are newly described, excellent seed cells that have good differentiation capability and are convenient to obtain. However, it is important to develop a method to isolate and culture AF-MSC efficiently. Amniotic fluid samples were obtained from rabbits and the adherence method was used for AF-MSC culture. Flow cytometry, western blot, and immunofluorescence studies were used to analyze the phenotypic characteristics of the cultured AF-MSC. Amniotic fluid-derived mesenchymal stem cells were successfully isolated and cultured from amniotic fluid. Flow cytometric analysis demonstrated that these cells expressed CD29 and CD44, while they did not express CD34. The expression of transcription factor Oct-4 was confirmed by western blot and immunofluorescence analysis. Using the adherence method, we developed a successful, reproducible protocol for the isolation of AF-MSC from amniotic fluid. The results of our phenotypic analysis revealed that the AF-MSC isolated in the present study were multipotent cells.
A semi-automated analytical platform featuring the coupling of monolithic reversed-phase liquid chromatography (RPLC) to matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI MSI) has been developed and evaluated. This is the first time that LC separation is readily coupled to MS imaging detection for the analysis of complex peptide mixtures both qualitatively and quantitatively. Methacrylate-based monolithic column with C12 functional groups is fabricated for fast RPLC separation. The LC flow and matrix flow are collected on a commercially available MALDI plate which is mechanically controlled and analyzed with MALDI MSI subsequently. Both tryptic peptides digested from bovine serum albumin (BSA) and endogenous neuropeptides extracted from the blue crab Callinectes sapidus are analyzed with this novel LC-MSI platform. Compared with regular offline LC fractionation coupled with MALDI MS detection, LC-MSI exhibits significantly increased MS signal intensity due to retaining of temporal resolution from separation dimension via continuous sampling, which results in increased number of peptides detected and accurate quantitation. In addition, imaging signals enable improved data analysis based on either mass-to-charge ratio or retention time, which is extremely beneficial for the analysis of complex analytes. These findings have demonstrated the potential of employing LC-MSI platform for enhanced proteomics and peptidomics studies.
A general method for constructing both 2-acylindoles and 2-acylindolines via I2-mediated intramolecular C-N bond formation is presented, and the selective formation of either 2-acylindoles or 2-acylindolines just depends on the nitrogen protecting groups used in the same substrate skeletons.
In this article, the very recent progress of various functional inorganic nanomaterials is reviewed including their unique properties, surface functionalization strategies, and applications in biosensing and imaging-guided therapeutics. The proper surface functionalization renders them with stability, biocompatibility and functionality in physiological environments, and further enables their targeted use in bioapplications after bioconjugation via selective and specific recognition. The surface-functionalized nanoprobes using the most actively studied nanoparticles (i.e., gold nanoparticles, quantum dots, upconversion nanoparticles, and magnetic nanoparticles) make them an excellent platform for a wide range of bioapplications. With more efforts in recent years, they have been widely developed as labeling probes to detect various biological species such as proteins, nucleic acids and ions, and extensively employed as imaging probes to guide therapeutics such as drug/gene delivery and photothermal/photodynamic therapy.
Real-time monitoring of nitric oxide concentrations is of central importance for probing the diverse roles of nitric oxide in neurotransmission, cardiovascular systems and immune responses. Here we report a new design of nitric oxide sensors based on hemin-functionalized graphene field-effect transistors. With its single atom thickness and the highest carrier mobility among all materials, graphene holds the promise for unprecedented sensitivity for molecular sensing. The non-covalent functionalization through ?-? stacking interaction allows reliable immobilization of hemin molecules on graphene without damaging the graphene lattice to ensure the highly sensitive and specific detection of nitric oxide. Our studies demonstrate that the graphene-hemin sensors can respond rapidly to nitric oxide in physiological environments with a sub-nanomolar sensitivity. Furthermore, in vitro studies show that the graphene-hemin sensors can be used for the detection of nitric oxide released from macrophage cells and endothelial cells, demonstrating their practical functionality in complex biological systems.
Multifunctional polymeric nano- and microparticles are engineered as theranostic carriers and their selective size-dependent cellular uptake is demonstrated. It is found that effective uptake and accumulation of nanoparticles occurs in both normal and cancer cells, whereas, that of microparticles occurs in cancer cells but not in normal cells, allowing cancer cells to be specifically targeted for local drug delivery.
Apoptosis in murine dermal cells is retarded by ultraviolet B (UVB) irradiation-induced autophagic intervention while simultaneously epidermal cells commit apoptosis, during which inflammatory cytokines released from the lost epidermal cells promote immune responses of dermal inflammatory cells, forming morphological symptoms of acute cutaneous diseases. Autophagy is involved in prevention or provocation of apoptosis of dermal or epidermal cells of UVB-irradiated mice via modulation of intracellular metabolism, intervening the balance between cell death and survival in dermis and epidermis. p53 expressed in immune system affects autophagy function through activating or inactivating genes encoding apoptotic factors and inflammatory cytokines. Silibinin protects dermal and epidermal cells of UVB irradiated skin against abnormally autophagy-mediated apoptosis adjustments. In this study, how UVB irradiation intervenes autophagy in dermal and epidermal cells as well as how silibinin protects UVB irradiated skin through physiological recovering of autophagy function in dermis and epidermis are focused and elucidated preliminarily. Silibinin treatment (50 mg/kg/day for 4 days) reversed dermal and epidermal autophagy levels from UVB irradiation-induced improper autophagy intervention, repaired the balance between cell survival and death in dermis and epidermis, and protected skin against damage through mediation of p53 activation in dermal and epidermal cells.
The safe, targeted and effective delivery of gene therapeutics remains a significant barrier to their broad clinical application. Here we develop a magnetic nucleic acid delivery system composed of iron oxide nanoparticles and cationic lipid-like materials termed lipidoids. Coated nanoparticles are capable of delivering DNA and siRNA to cells in culture. The mean hydrodynamic size of these nanoparticles was systematically varied and optimized for delivery. While nanoparticles of different sizes showed similar siRNA delivery efficiency, nanoparticles of 50-100 nm displayed optimal DNA delivery activity. The application of an external magnetic field significantly enhanced the efficiency of nucleic acid delivery, with performance exceeding that of the commercially available lipid-based reagent, Lipofectamine 2000. The iron oxide nanoparticle delivery platform developed here offers the potential for magnetically guided targeting, as well as an opportunity to combine gene therapy with MRI imaging and magnetic hyperthermia.
The CdTe quantum dots (QDs), graphene nanocomposite (CdTe-G) and dextran-Fe3O4 magnetic nanoparticles have been synthesized for developing an ultrasensitive electrochemiluminescence (ECL) immunoassay for Carcinoembryonic antigen 19-9 (CA 19-9) in serums. Firstly, the capture probes (CA 19-9 Ab1/Fe3O4) for enriching CA 19-9 were synthesized by immobilizing the CA 19-9s first antibody (CA 19-9 Ab1) on magnetic nanoparticles (dextran-Fe3O4). Secondly, the signal probes (CA 19-9 Ab2/CdTe-G), which can emit an ECL signal, were formed by attaching the secondary CA 19-9 antibody (CA 19-9 Ab2) to the surface of the CdTe-G. Thirdly, the above two probes were used for conjugating with a serial of CA 19-9 concentrations. Graphene can immobilize dozens of CdTe QDs on their surface, which can emit stronger ECL intensity than CdTe QDs. Based on the amplified signal, ultrasensitive antigen detection can be realized. Under the optimal conditions, the ECL signal depended linearly on the logarithm of CA 19-9 concentration from 0.005 to 100 pg/mL, and the detection limit was 0.002 pg/mL. Finally, five samples of human serum were tested, and the results were compared with a time-resolved fluorescence assay (TRFA). The novel immunoassay provides a stable, specific and highly sensitive immunoassay protocol for tumor marker detection at very low levels, which can be applied in early diagnosis of tumor.
MicroRNAs (miRNAs) participate in the regulation of cardiac hypertrophy. However, it remains largely unknown as to how miRNAs are integrated into the hypertrophic program. Ca/calmodulin-dependent protein kinase II (CaMKII) is a hypertrophic signaling marker. It is not yet clear which miRNAs can regulate CaMKII?.
Exfoliation of layered materials such as graphite and transition metal dichalcogenides into mono- or few-layers is of significant interest for both the fundamental studies and potential applications. Here we report a systematic investigation of the fundamental factors governing the liquid exfoliation process and the rational design of a cosolvent approach for the exfoliation of layered materials. We show that Youngs equation can be used to predict the optimal cosolvent concentration for the effective exfoliation of graphite and molybdenum disulphide in water mixtures with methanol, ethanol, isopropanol and t-butyl alcohol. Moreover, we find that the cosolvent molecular size has an important role in the exfoliation yield, attributed to the larger steric repulsion provided by the larger cosolvent molecules. Our study provides critical insight into the exfoliation of layered materials, and defines a rational strategy for the design of an environmentally friendly pathway to the high yield exfoliation of layered materials.
Nerve cell injury associated with apoptosis plays an important role in the development of diabetic peripheral neuropathy (DPN). However, it remains unclear whether preexisting or potential neurocyte damage induced by hyperglycemia increases sensitivity to local anesthetics. SH-SY5Y cells were pretreated with a high concentration of glucose in vitro, to imitate DPN prior to administration of bupivacaine or placebo. Cell viability and apoptosis were investigated with a CCK-8 assay and flow cytometry, respectively. In addition, mitochondrial membrane potential, reactive oxygen species (ROS), mitochondrially generated ROS, and activity of mitochondrial complexes I and III were studied to explore the molecular mechanism of bupivacaine-induced mitochondrial injury. Grp78 and caspase-12 expression were measured by qRT-PCR and Western blot, representing endoplasmic reticulum (ER) stress. Cell structure was also assessed via transmission electron microscopy. Incubation with bupivacaine decreased the activity of mitochondrial complexes I and III; increased ROS production at cell and mitochondrial levels, mitochondrial potential depolarization, and Grp78 and caspase-12 expression at both transcription and translation levels; and affected cell structure, which could be enhanced by glucose pretreatment. These findings indicate that mitochondrial dysfunction and ER stress related to ROS are involved in bupivacaine-induced apoptosis and may be enhanced by glucose administration.
We demonstrated unconscious learning of task-irrelevant perceptual regularities in a Serial Reaction Time (SRT) task in both visual and auditory domains. Participants were required to respond to different letters (F or J, experiment 1) or syllables (can or you, experiment 2) which occurred in random order. Unbeknownst to participants, the color (red, green, blue or yellow) of the two letters or the tone (1-4) of the syllables varied according to certain rules. Reaction times indicated that people indeed learnt both the color and tonal regularities indicating that task-irrelevant sequence structure can be learned perceptually. In a subsequent prediction test of knowledge of the color or tonal cues using subjective measures, we showed that people could acquire task irrelevant knowledge unconsciously.
The transcription factor zinc-finger protein Miz1 represses TNF-?-induced JNK activation and the repression is relieved upon TNF-? stimulation. However, the underlying mechanism is incompletely understood. Here we report that Miz1 interferes with the ubiquitin conjugating enzyme (E2) Ubc13 for binding to the RING domain of TNF-receptor associated factor 2 (TRAF2), thereby inhibiting the ubiquitin ligase (E3) activity of TRAF2 and suppressing TNF-?-induced JNK activation. Upon TNF-? stimulation, Miz1 rapidly undergoes K48-linked polyubiquitination at Lys388 and Lys472 residues and subsequent proteasomal degradation in a TRAF2-dependent manner. Replacement of Lysine 388 and Lysine 472 by arginines generates a nondegradable Miz1 mutant, which significantly suppresses TNF-?-induced JNK1 activation and inflammation. Thus, our results reveal a molecular mechanism by which the repression of TNF-?-induced JNK activation by Miz1 is de-repressed by its own site-specific ubiquitination and degradation, which may account for the temporal control of TNF-?-JNK signaling.
Icariin had been reported as a potential agent for osteogenesis, but the dose-effect relationship needed further research to realize the clinical application of icariin. We isolated and purified human bone mesenchymal stem cells (hBMSCs) and stimulated them with different concentrations of icariin. The cytotoxicity of icariin was evaluated by the methylthiazolytetrazolium (MTT) assay method. The proliferation and osteogenic differentiation of such hBMSCs were investigated for different concentrations of icariin. We found that icariin had a dose-dependent effect on the proliferation and osteogenic differentiation of hBMSCs in a suitable concentration range from 10(-9) M to 10(-6) M, but at concentrations above 10(-5) M, the cytotoxicity limited its use. The extremely low cost of icariin and its high abundance make it appealing for bone regeneration.
OBJECTIVE To explore the role of runt-related transcription factor 3(RUNX3) in the tumorgenesis and progression of cervical carcinoma. METHODS The immunohistochemical staining technique was used to detect the expression of RUNX3 protein in 25 cases of normal cervix, 34 intraepithelia neoplasia (CIN), and 48 cervical carcinomas. SYBR Green I chimeric fluorescence Real-time PCR was applied to detect the expression of RUNX3 mRNA in 10 cases of normal cervix, 24 CIN, and 30 cervical carcinomas. RESULTS The expressions of RUNX3 protein and mRNA in normal cervix, CINI,CINII-III, and cervical carcinoma tissues tended to be down-regulated. There was significant difference among these groups (P<0.05). The expressions of RUNX3 protein and mRNA in the cervical carcinoma tissues were correlated with the histological differentiation, clinical stage, and lymphatic metastasis (P<0.05), but had no relationship with the age, high-risk human papillomavirus infection, and histological classification (P> 0.05). CONCLUSION RUNX3 may function as a tumor suppressor gene in the occurrence and progression of cervical carcinoma.
Mir-17-92 encodes 6 miRNAs inside a single polycistronic transcript, the proper expression of which is critical for early B-cell development and lymphocyte homeostasis. However, during the T-cell antigen response, the physiologic function of endogenous miR-17-92 and the roles of the individual miRNAs remain elusive. In the present study, we functionally dissected the miR-17-92 cluster and revealed that miR-17 and miR-19b are the key players controlling Th1 responses through multiple coordinated biologic processes. These include: promoting proliferation, protecting cells from activation-induced cell death, supporting IFN-? production, and suppressing inducible regulatory T-cell differentiation. Mechanistically, we identified Pten (phosphatase and tensin homolog) as the functionally important target of miR-19b, whereas the function of miR-17 is mediated by TGF?RII and the novel target CREB1. Because of its vigorous control over the Th1 cell-inducible regulatory T cell balance, the loss of miR-17-92 in CD4 T cells results in tumor evasion. Our results suggest that miR-19b and miR-17 could be harnessed to enhance the efficacy of T cell-based tumor therapy.
Dendritic cells (DCs) can inhibit immune response by clonal anergy when immature. Recent studies have shown that immature DCs (iDCs) may serve as a live cell vaccine after specific antigen pulse based on its potential of blocking antibody production. In this study, we aimed to investigate the effects of nuclear antigen-pulsed iDCs in the treatment of lupus-like renal damages induced by anti-dsDNA antibodies.
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