JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Functional Analyses of the Diels-Alderase Gene sol5 of Ascochyta rabiei and Alternaria solani Indicate that the Solanapyrone Phytotoxins Are Not Required for Pathogenicity.
Mol. Plant Microbe Interact.
PUBLISHED: 11-06-2014
Show Abstract
Hide Abstract
Ascochyta rabiei and Alternaria solani, the causal agents of Ascochyta blight of chickpea (Cicer arietinum) and early blight of potato (Solanum tuberosum), respectively, produce a set of phytotoxic compounds including solanapyrones A, B, and C. Although both the phytotoxicity of solanapyrones and their universal production among field isolates have been documented, the role of solanapyrones in pathogenicity is not well understood. Here we report the functional characterization of the sol5 gene, which encodes a Diels-Alderase that catalyzes the final step of solanapyrone biosynthesis. Deletion of sol5 in both A. rabiei and Al. solani completely prevented production of solanapyrones and led to accumulation of the immediate precursor compound prosolanapyrone II-diol, which is not toxic to plants. Deletion of sol5 did not negatively affect growth rate or spore production in vitro, and led to overexpression of the other solanapyrone biosynthesis genes, suggesting a possible feedback regulation mechanism. Phytotoxicity tests showed that solanapyrone A is highly toxic to several legume species and Arabidopsis thaliana. Despite the apparent phytotoxicity of solanapyrone A, pathogenicity tests showed that solanapyrone-minus mutants of A. rabiei and Al. solani were equally virulent as their corresponding wild-type progenitors, suggesting that solanapyrones are not required for pathogenicity.
Related JoVE Video
Development of novel combined anti-calcification protocols including immunologic modification for prolonged durability of cardiac xenograft: Preclinical study using large-animal long-term circulatory models.
ASAIO J.
PUBLISHED: 10-12-2014
Show Abstract
Hide Abstract
Cardiac xenografts are conventionally cross-linked with glutaraldehyde (GA) to impart tissue stability, reduce antigenicity, and maintain tissue sterility. However, GA-fixed xenografts are prone to calcification after long-term implantation in humans, because of phospholipids, free aldehyde groups, and residual antigenicity. We evaluated preclinical safety and efficacy using large-animal long-term circulatory models for our novel combined anti-calcification protocol including immunological modification, which had been proven effective in small animal experiments. Bovine/porcine xenografts were treated with decellularization, immunological modification with ?galactosidase, GA fixation with organic solvent, and detoxification with glycine. Valve conduits made of these xenografts were transplanted into the pulmonary root of goats, and hemodynamic, radiological, immunohistopathological, and biochemical results were obtained for 12 months after implantation. Evaluation of echocardiography and cardiac catheterization demonstrated good hemodynamic status and function of the pulmonary xenograft valves. Durability of the xenografts was well preserved without calcification by specimen radiography and immunohistopathological examination. The calcium concentrations of the explanted xenografts were lower than the control xenografts. This preclinical study using large-animal long-term circulatory models demonstrated that our synergistic and simultaneous employment of multiple anti-calcification therapies and novel tissue treatments, including immunological modifications, has promising safety and efficacy and should be examined further in future clinical studies.
Related JoVE Video
Development of the large-scale oligonucleotide chip for the diagnosis of plant viruses and its practical use.
Plant Pathol. J.
PUBLISHED: 10-08-2014
Show Abstract
Hide Abstract
A large-scale oligonucleotide (LSON) chip was developed for the detection of the plant viruses with known genetic information. The LSON chip contains two sets of 3,978 probes for 538 species of targets including plant viruses, satellite RNAs and viroids. A hundred forty thousand probes, consisting of isolate-, species- and genus-specific probes respectively, are designed from 20,000 of independent nucleotide sequence of plant viruses. Based on the economic importance, the amount of genome information, and the number of strains and/or isolates, one to fifty-one probes for each target virus are selected and spotted on the chip. The standard and field samples for the analysis of the LSON chip have been prepared and tested by RT-PCR. The probe's specific and/or nonspecific reaction patterns by LSON chip allow us to diagnose the unidentified viruses. Thus, the LSON chip in this study could be highly useful for the detection of unexpected plant viruses, the monitoring of emerging viruses and the fluctuation of the population of major viruses in each plant.
Related JoVE Video
Oak tree canker disease supports arthropod diversity in a natural ecosystem.
Plant Pathol. J.
PUBLISHED: 10-08-2014
Show Abstract
Hide Abstract
Microorganisms have many roles in nature. They may act as decomposers that obtain nutrients from dead materials, while some are pathogens that cause diseases in animals, insects, and plants. Some are symbionts that enhance plant growth, such as arbuscular mycorrhizae and nitrogen fixation bacteria. However, roles of plant pathogens and diseases in natural ecosystems are still poorly understood. Thus, the current study addressed this deficiency by investigating possible roles of plant diseases in natural ecosystems, particularly, their positive effects on arthropod diversity. In this study, the model system was the oak tree (Quercus spp.) and the canker disease caused by Annulohypoxylon truncatum, and its effects on arthropod diversity. The oak tree site contained 44 oak trees; 31 had canker disease symptoms while 13 were disease-free. A total of 370 individual arthropods were detected at the site during the survey period. The arthropods belonged to 25 species, 17 families, and seven orders. Interestingly, the cankered trees had significantly higher biodiversity and richness compared with the canker-free trees. This study clearly demonstrated that arthropod diversity was supported by the oak tree canker disease.
Related JoVE Video
In vivo efficacy for novel combined anticalcification treatment of glutaraldehyde-fixed cardiac xenograft using humanized mice.
J Biomater Appl
PUBLISHED: 09-24-2014
Show Abstract
Hide Abstract
The animal immune response against Gal?1,3-Gal?1-4GlcNAc-R(?-Gal) epitopes gives an important cause for the failure of glutaraldehyde(GA)-fixed cardiac xenografts. This study aimed to assess the in vivo effect of our novel combined anticalcification treatment, which includes immunologic modification, using ?1,3-galactosyltransferase knock-out mice to mimic human immunologic environment. Bovine pericardia were cross-linked with GA and treated with decellularization, immunologic modification with ?-galactosidase, space-filler with polyethylene glycol, organic solvent, and detoxification. The bovine pericardia were subcutaneously implanted into humanized and wild type mice, and titers of anti ?-Gal IgM and IgG were evaluated at various time intervals. In vivo calcification and immunohistochemistry staining was assessed for the explanted xenografts several months after implantation. In humanized mice, titers for anti ?-Gal IgM and IgG increased as the period of implantation increased, and reduced with our anticalcification treatments. The humanized mice had more in vivo calcification in GA-fixed xenografts treated with our anticalcification protocol compared with wild type mice. In humanized mice, in vivo calcification reduced with our combined anticalcification treatment, and the immunohistochemistry of the harvested xenografts proved the compatible findings with the results of in vivo immunogenicity and calcification. Humanized mice are effective model for the assessment of in vivo calcification, and our combined anticalcification treatments reduced in vivo calcification as well as in vivo immunogenicity in humanized mice group, suggesting that the animal immune reaction is the cause for calcification. Our novel combined anticalcification strategies of decellularization, immunologic modification, space-filler, organic solvent, and detoxification have possible promise to prolong the lifespan of cardiac xenograft.
Related JoVE Video
The International Xenotransplantation Association consensus statement on conditions for undertaking clinical trials of xenocorneal transplantation.
Xenotransplantation
PUBLISHED: 09-01-2014
Show Abstract
Hide Abstract
To develop an international consensus regarding the appropriate conditions for undertaking clinical trials in xenocorneal transplantation, here we review specific ethical, logistical, scientific, and regulatory issues regarding xenocorneal transplantation, and propose guidelines for conduct of clinical xenocorneal transplantation trials. These proposed guidelines are modeled on the published consensus statement of the International Xenotransplantation Association regarding recommended guidelines for conduct of clinical islet xenotransplantation. It is expected that this initial consensus statement will be revised over time in response to scientific advances in the field, and changes in the regulatory framework based on accumulating clinical experience.
Related JoVE Video
Thiol-activated gem-dithiols: a new class of controllable hydrogen sulfide donors.
Org. Lett.
PUBLISHED: 08-20-2014
Show Abstract
Hide Abstract
A class of novel thiol-activated H2S donors has been developed on the basis of the gem-dithiol template. These donors release H2S in the presence of cysteine or GSH in aqueous solutions as well as in cellular environments.
Related JoVE Video
Trafficking of LAG-3 to the surface on activated T cells via its cytoplasmic domain and protein kinase C signaling.
J. Immunol.
PUBLISHED: 08-08-2014
Show Abstract
Hide Abstract
Lymphocyte activation gene-3 (LAG-3; CD223), a structural homolog of CD4, binds to MHC class II molecules. Recent research indicated that signaling mediated by LAG-3 inhibits T cell proliferation, and LAG-3 serves as a key surface molecule for the function of regulatory T cells. Previous reports demonstrated that the majority of LAG-3 is retained in the intracellular compartments and is rapidly translocated to the cell surface upon stimulation. However, the mechanism by which LAG-3 translocates to the cell surface was unclear. In this study, we examined the trafficking of human LAG-3 under unstimulated as well as stimulated conditions of T cells. Under the unstimulated condition, the majority of LAG-3 did not reach the cell surface, but rather degraded within the lysosomal compartments. After stimulation, the majority of LAG-3 translocated to the cell surface without degradation in the lysosomal compartments. Results indicated that the cytoplasmic domain without Glu-Pro repetitive sequence is critical for the translocation of LAG-3 from lysosomal compartments to the cell surface. Moreover, protein kinase C signaling leads to the translocation of LAG-3 to the cell surface. However, two potential serine phosphorylation sites from the LAG-3 cytoplasmic domain are not involved in the translocation of LAG-3. These results clearly indicate that LAG-3 trafficking from lysosomal compartments to the cell surface is dependent on the cytoplasmic domain through protein kinase C signaling in activated T cells.
Related JoVE Video
[Recurrence of multiple focal nodular hyperplasia in a young male patient].
Korean J Gastroenterol
PUBLISHED: 07-31-2014
Show Abstract
Hide Abstract
Focal nodular hyperplasia (FNH) is the second most common benign hepatic tumor that is usually found in women. Diagnosis of FNH mainly depends on imaging studies such as color Doppler flow imaging, computed tomography, and magnetic resonance imaging. It is characterized by the presence of stellate central scar and is nowadays incidentally diagnosed with increasing frequency due to advances in radiologic imaging technique. FNH typically presents as a single lesion in 70% of cases and generally does not progress to malignancy or recur after resection. Herein, we report a case of a young male patient with recurrent multiple FNH who underwent surgical resection for presumed hepatic adenoma on computed tomography.
Related JoVE Video
The Arabidopsis thaliana RNA-binding protein FCA regulates thermotolerance by modulating the detoxification of reactive oxygen species.
New Phytol.
PUBLISHED: 07-24-2014
Show Abstract
Hide Abstract
Heat stress affects various aspects of plant growth and development by generating reactive oxygen species (ROS) which cause oxidative damage to cellular components. However, the mechanisms by which plants cope with ROS accumulation during their thermotolerance response remain largely unknown. Here, we demonstrate that the RNA-binding protein FCA, a key component of flowering pathways in Arabidopsis thaliana, is required for the acquisition of thermotolerance. Transgenic plants overexpressing the FCA gene (35S:FCA) were resistant to heat stress; the FCA-defective fca-9 mutant was sensitive to heat stress, consistent with induction of the FCA gene by heat. Furthermore, total antioxidant capacity was higher in the 35S:FCA transgenic plants but lower in the fca-9 mutant compared with wild-type controls. FCA interacts with the ABA-INSENSITIVE 5 (ABI5) transcription factor, which regulates the expression of genes encoding antioxidants, including 1-CYSTEINE PEROXIREDOXIN 1 (PER1). We found that FCA is needed for proper expression of the PER1 gene by ABI5. Our observations indicate that FCA plays a role in the induction of thermotolerance by triggering antioxidant accumulation under heat stress conditions, thus providing a novel role for FCA in heat stress responses in plants.
Related JoVE Video
Apelin is transcriptionally regulated by ER stress-induced ATF4 expression via a p38 MAPK-dependent pathway.
Apoptosis
PUBLISHED: 07-24-2014
Show Abstract
Hide Abstract
Apelin, which is an endogenous ligand for the orphan G-protein-coupled receptor APJ, was reported to be up-regulated by hypoxia-inducible factor 1-? (HIF1-?) in hypoxia- and insulin-treated cell systems. However, a negative transcriptional regulator of apelin has not yet been identified. In this study, we showed that apelin is down-regulated by ATF4 via the pro-apoptotic p38 MAPK pathway under endoplasmic reticulum (ER) stress. First, we analyzed the human apelin promoter to characterize the effects of ER stress on apelin expression in hepatocytes. Treatment with thapsigargin, an inducer of ER stress, and over-expression of ATF4 decreased apelin expression in hepatocytes. This work identified an ATF4-responsive region within the apelin promoter. Interestingly, ATF4-mediated repression of apelin was dependent upon the N-terminal domain of ATF4. C/EBP-? knockdown experiments suggest that C/EBP-?, which acts as an ATF4 binding partner, is critical for the ER stress-induced down-regulation of apelin. We also demonstrated that ATF4 regulates apelin gene expression via p38 pathways. Ectopic expression of constitutively active MKK6, an upstream kinase of p38, suggested that activation of the p38 pathway is sufficient to induce ATF4-mediated repression of apelin. Moreover, apelin enhanced cell migration in a wound healing assay in a p38 MAPK-dependent manner. Furthermore, analysis of caspase-3 activation indicated that ATF4 knockdown up-regulated apelin expression, leading to the inability of MKK6 (CA) to exert pro-apoptotic effects. Taken together, our results suggest that ATF4-mediated repression of apelin contributes substantially to the pro-apoptotic effects of p38.
Related JoVE Video
High-sensitivity fluorescence imaging of iron in plant tissues.
Chem. Commun. (Camb.)
PUBLISHED: 06-24-2014
Show Abstract
Hide Abstract
Here, we report a method for high-sensitivity fluorescence imaging of iron, which demonstrates the abundance and distribution of iron in plant tissues more precisely than conventional histochemical staining procedures. The fluorescence turn-on method is rapid (<20 min), inexpensive to set up, and expected to be readily applicable to any plant tissues.
Related JoVE Video
Minimizing immunosuppression in islet xenotransplantation.
Immunotherapy
PUBLISHED: 05-13-2014
Show Abstract
Hide Abstract
Pancreatic islet transplantation is a promising treatment option for Type 1 diabetes, but organ supply shortage limits its wide adoption. Pig islets are the most promising alternative source and many important measures such as donor animal selection, pig islet production release criteria, preclinical data and zoonosis surveillance prior to human clinical trials have been put forward as a consensus through the efforts of the International Xenotransplantation Association. To bring pig islet transplantation to clinical reality, the development of clinically applicable immunosuppression regimens and methods to minimize immunosuppression to reduce side effects should be established. This review encompasses immune rejection mechanisms in islet xenotransplantation, immunosuppression regimens that have enabled long-term graft survival in pig-to-nonhuman primate experiments and strategies for minimizing immunosuppression in islet xenotransplantation. By thoroughly examining the drugs that are currently available and in development and their individual targets within the immune response, the best strategy for enabling clinical trials of pig islets for Type 1 diabetes will be proposed.
Related JoVE Video
Sleep disturbances and predictive factors in caregivers of patients with mild cognitive impairment and dementia.
J Clin Neurol
PUBLISHED: 05-12-2014
Show Abstract
Hide Abstract
We examined the characteristics of sleep disturbances and sleep patterns in the caregivers of patients with amnestic mild cognitive impairment (aMCI) and dementia.
Related JoVE Video
FCA mediates thermal adaptation of stem growth by attenuating auxin action in Arabidopsis.
Nat Commun
PUBLISHED: 04-29-2014
Show Abstract
Hide Abstract
Global warming is predicted to profoundly affect plant distribution and crop yield in the near future. Higher ambient temperature can influence diverse aspects of plant growth and development. In Arabidopsis, the basic helix-loop-helix transcription factor PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) regulates temperature-induced adaptive responses by modulating auxin biosynthesis. At high temperature, PIF4 directly activates expression of YUCCA8 (YUC8), a gene encoding an auxin biosynthetic enzyme, resulting in auxin accumulation. Here we demonstrate that the RNA-binding protein FCA attenuates PIF4 activity by inducing its dissociation from the YUC8 promoter at high temperature. At 28?°C, auxin content is elevated in FCA-deficient mutants that exhibit elongated stems but reduced in FCA-overexpressing plants that exhibit reduced stem growth. We propose that the FCA-mediated regulation of YUC8 expression tunes down PIF4-induced architectural changes to achieve thermal adaptation of stem growth at high ambient temperature.
Related JoVE Video
Molecular cloning and expression analysis of pig CD7.
Vet. Res. Commun.
PUBLISHED: 04-17-2014
Show Abstract
Hide Abstract
CD7 is an integral membrane protein which mediates an important signal to mediate the differentiation, activation, and regulation of some T cells and NK cells. However, only human and mouse CD7 have been identified and studied among mammalian species. In this study, we cloned pig CD7 cDNA and determined its complete cDNA sequence. Pig CD7 cDNA contained an open reading frame (627 bp) encoding 208 amino acids with well conserved motifs involved in signal transduction within cytoplasmic tail among mammalian species. Pig CD7 mRNA was detected by RT-PCR in mainly lymphoid tissues, indicating the conserved functions of CD7 in pigs. Moreover, we generated soluble pig CD7 fusion immunoglobulin (pig CD7Ig) containing extracellular domain of pig CD7 to test whether pig CD7 binds to pig galectin-3. Flow cytometry and immunohistochemistry analyses indicated that soluble pig CD7Ig can bind to galectin-3 expressed in macrophages and epithelial cells of small intestine. These results help to analyze the structural relationship between CD7 and its ligand transferring signal transduction among mammalian species.
Related JoVE Video
The effect of propofol on intravenous glucose tolerance test in rhesus monkey.
J. Med. Primatol.
PUBLISHED: 04-11-2014
Show Abstract
Hide Abstract
Many anesthetics have been shown to impair glucose metabolism and cause hyperglycemia. The aim of this study was to evaluate the effects of propofol on glucose metabolism and insulin secretion during intravenous glucose tolerance test (IVGTT) in rhesus monkey.
Related JoVE Video
Effect of Rivastigmine or Memantine Add-on Therapy Is Affected by Butyrylcholinesterase Genotype in Patients with Probable Alzheimer's Disease.
Eur. Neurol.
PUBLISHED: 04-08-2014
Show Abstract
Hide Abstract
Background: The K variant of butyrylcholinesterase (BCHE-K) exhibits a reduced acetylcholine-hydrolyzing capacity; so the clinical response to rivastigmine may differ in Alzheimer's disease (AD) patients with the BCHE-K gene. Objective: To investigate the clinical response to rivastigmine transdermal patch monotherapy or memantine plus rivastigmine transdermal patch therapy in AD patients based on the BCHE-K gene. Methods: A total of 146 probable AD patients consented to genetic testing for butyrylcholinesterase and underwent the final efficacy evaluations. Responders were defined as patients with an equal or better score on the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) at 16 weeks compared to their baseline score. Results: BCHE-K carriers showed a lower responder rate on the ADAS-cog than non-carriers (38.2 vs. 61.7%, p = 0.02), and this trend was evident in AD patients with apolipoprotein E ? 4 (35 vs. 60.7%, p = 0.001). The presence of the BCHE-K allele predicted a worse response on the ADAS-cog (odds ratio 0.35, 95% confidence interval 0.14-0.87), after adjusting for demographic and baseline cognitive and functional variables. Conclusion: The BCHE-K genotype may be related to a poor cognitive response to rivastigmine patch or memantine add-on therapy, especially in the presence of apolipoprotein E ? 4. © 2014 S. Karger AG, Basel.
Related JoVE Video
The role of the alternative complement pathway in early graft loss after intraportal porcine islet xenotransplantation.
Transplantation
PUBLISHED: 04-08-2014
Show Abstract
Hide Abstract
Intraportal islet transplantation (ITx) causes instant blood-mediated inflammatory reaction (IBMIR), resulting in an early loss of transplanted islets. Porcine islets, transplanted intraportally into nonhuman primates (NHPs), induce complement activation, contributing to the development of IBMIR; however, the exact mechanism is not clear.
Related JoVE Video
The Arabidopsis NAC transcription factor NTL4 participates in a positive feedback loop that induces programmed cell death under heat stress conditions.
Plant Sci.
PUBLISHED: 03-31-2014
Show Abstract
Hide Abstract
Programmed cell death (PCD) is an integral component of plant development and adaptation under adverse environmental conditions. Reactive oxygen species (ROS) are one of the most important players that trigger PCD in plants, and ROS-generating machinery is activated in plant cells undergoing PCD. The membrane-bound NAC transcription factor NTL4 has recently been proven to facilitate ROS production in response to drought stress in Arabidopsis. In this work, we show that NTL4 participates in a positive feedback loop that bursts ROS accumulation to modulate PCD under heat stress conditions. Heat stress induces NTL4 gene transcription and NTL4 protein processing. The level of hydrogen peroxide (H2O2) was elevated in 35S:4?C transgenic plants that overexpress a transcriptionally active nuclear NTL4 form but significantly reduced in NTL4-deficient ntl4 mutants under heat stress conditions. In addition, heat stress-induced cell death was accelerated in the 35S:4?C transgenic plants but decreased in the ntl4 mutants. Notably, H2O2 triggers NTL4 gene transcription and NTL4 protein processing under heat stress conditions. On the basis of these findings, we conclude that NTL4 modulates PCD through a ROS-mediated positive feedback control under heat stress conditions, possibly providing an adaptation strategy by which plants ensure their survival under extreme heat stress conditions.
Related JoVE Video
Alternative splicing and nonsense-mediated decay of circadian clock genes under environmental stress conditions in Arabidopsis.
BMC Plant Biol.
PUBLISHED: 02-05-2014
Show Abstract
Hide Abstract
The circadian clock enables living organisms to anticipate recurring daily and seasonal fluctuations in their growth habitats and synchronize their biology to the environmental cycle. The plant circadian clock consists of multiple transcription-translation feedback loops that are entrained by environmental signals, such as light and temperature. In recent years, alternative splicing emerges as an important molecular mechanism that modulates the clock function in plants. Several clock genes are known to undergo alternative splicing in response to changes in environmental conditions, suggesting that the clock function is intimately associated with environmental responses via the alternative splicing of the clock genes. However, the alternative splicing events of the clock genes have not been studied at the molecular level.
Related JoVE Video
Effects of reduction in the alpha-gal antigen on bony union: a model of xenobone graft using GalT knockout mouse.
Xenotransplantation
PUBLISHED: 02-05-2014
Show Abstract
Hide Abstract
Among the bone graft sources used currently, the availability of autografts is limited and allografts are expensive. Therefore, xenobone grafts have drawn attention as a new source of bone grafts, although immunologic rejection issues are unresolved. This study used a GalT knockout mouse model to investigate the effects of reducing the alpha-gal epitope using alpha-galactosidase on the union of porcine xenobone grafts.
Related JoVE Video
Beyond ubiquitination: proteolytic and nonproteolytic roles of HOS1.
Trends Plant Sci.
PUBLISHED: 01-16-2014
Show Abstract
Hide Abstract
The E3 ubiquitin ligase HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES 1 (HOS1) functions as a cold signaling attenuator by degrading the INDUCER OF CBF EXPRESSION 1 transcription factor, which is a key regulator of the cold-induced transcriptome and freezing tolerance in plants. Recent studies demonstrate that HOS1 also plays nonproteolytic roles in gene expression regulation. HOS1 acts as a chromatin remodeling factor that modulates FLOWERING LOCUS C chromatin in cold regulation of flowering time. It associates with the nuclear pore complex to facilitate nucleocytoplasmic mRNA export to maintain circadian periodicity over a range of light and temperature conditions. In this review, we summarize recent advances in molecular mechanisms underlying HOS1 function during plant development in response to fluctuating environmental conditions.
Related JoVE Video
TOP 1 and 2, polysaccharides from Taraxacum officinale, inhibit NF?B-mediated inflammation and accelerate Nrf2-induced antioxidative potential through the modulation of PI3K-Akt signaling pathway in RAW 264.7 cells.
Food Chem. Toxicol.
PUBLISHED: 01-09-2014
Show Abstract
Hide Abstract
Anti-inflammatory and anti-oxidative activities of polysaccharides from Taraxacum officinale (TOP 1 and 2) were analyzed in RAW 264.7 cells. First, lipopolysaccharide (LPS) was applied to identify anti-inflammatory activity of TOPs, which reduced expression of inducible nitric oxide synthase (iNOS) and tumor necrosis factor (TNF)-?. TOPs treatment inhibited phosphorylation of inflammatory transcription factor, nuclear factor (NF)?B, and its upstream signaling molecule, PI3K/Akt. Second, cytoprotective potential of TOPs against oxidative stress was investigated via heme oxygenase (HO)-1 induction. HO-1, one of phase II enzymes shows antioxidative activity, was potently induced by TOPs treatment, which was in accordance with the nuclear translocation of nuclear factor-erythroid 2 p45-related factor 2 (Nrf2). In addition, TOPs treatment phosphorylated PI3K/Akt with slight activation of c-Jun NH2-terminal kinase (JNK). TOPs-mediated HO-1 induction protected macrophage cells from oxidative stress-induced cell death, which was confirmed by SnPP and CoPP (HO-1 inhibitor and inducer, respectively). Consequently, TOPs potently inhibited NF?B-mediated inflammation and accelerated Nrf2-mediated antioxidative potential through the modulation of PI3K/Akt pathway, which would contribute to their promising strategy for novel anti-inflammatory and anti-oxidative agents.
Related JoVE Video
Molecular and functional characterization of cold-responsive C-repeat binding factors from Brachypodium distachyon.
BMC Plant Biol.
PUBLISHED: 01-08-2014
Show Abstract
Hide Abstract
Adverse environmental conditions severely influence various aspects of plant growth and developmental processes, causing worldwide reduction of crop yields. The C-repeat binding factors (CBFs) are critical transcription factors constituting the gene regulatory network that mediates the acclimation process to low temperatures. They regulate a large number of cold-responsive genes, including COLD-REGULATED (COR) genes, via the CBF-COR regulon. Recent studies have shown that the CBF transcription factors also play a role in plant responses to drought and salt stresses. Putative CBF gene homologues and their downstream genes are also present in the genome of Brachypodium distachyon, which is perceived as a monocot model in recent years. However, they have not been functionally characterized at the molecular level.
Related JoVE Video
The miR172 target TOE3 represses AGAMOUS expression during Arabidopsis floral patterning.
Plant Sci.
PUBLISHED: 01-07-2014
Show Abstract
Hide Abstract
microRNA172 (miR172) regulates phase transition and floral patterning in Arabidopsis by repressing targets that encode the APETALA2 (AP2) and AP2-like transcription factors. The miR172-mediated repression of the AP2 gene restricts AGAMOUS (AG) expression. In addition, most miR172 targets, including AP2, redundantly act as floral repressors, and the overexpression of the target genes causes delayed flowering. However, how miR172 targets other than AP2 regulate both of the developmental processes remains unclear. Here, we demonstrate that miR172-mediated repression of the TARGET OF EAT 3 (TOE3) gene is critical for floral patterning in Arabidopsis. Transgenic plants that overexpress a miR172-resistant TOE3 gene (rTOE3-ox) exhibit indeterminate flowers with numerous stamens and carpelloid organs, which is consistent with previous observations in transgenic plants that overexpress a miR172-resistant AP2 gene. TOE3 binds to the second intron of the AG gene. Accordingly, AG expression is significantly reduced in rTOE3-ox plants. TOE3 also interacts with AP2 in the nucleus. Given the major role of AP2 in floral patterning, miR172 likely regulates TOE3 in floral patterning, at least in part via AP2. In addition, a miR156 target SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 3 directly activates TOE3 expression, revealing a novel signaling interaction between miR156 and miR172 in floral patterning.
Related JoVE Video
Clinical and genetic analysis of MAPT, GRN, and C9orf72 genes in Korean patients with frontotemporal dementia.
Neurobiol. Aging
PUBLISHED: 01-07-2014
Show Abstract
Hide Abstract
The hexanucleotide repeat expansion (GGGGCC) in chromosome 9 open-reading frame 72 (C9orf72) and mutations in the microtubule-associated protein tau (MAPT) and progranulin (GRN) genes are known to be associated with the main causes of familial or sporadic amyotrophic lateral sclerosis and frontotemporal dementia (FTD) in Western populations. These genetic abnormalities have rarely been studied in Asian FTD populations. We investigated the frequencies of mutations in MAPT and GRN and the C9orf72 abnormal expansion in 75 Korean FTD patients. Two novel missense variants of unknown significance in the MAPT and GRN were detected in each gene. However, neither abnormal C9orf72 expansion nor pathogenic MAPT or GRN mutation was found. Our findings indicate that MAPT, GRN, and C9orf72 mutations are rare causes of FTD in Korean patients.
Related JoVE Video
The Cold Signaling Attenuator HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE1 Activates FLOWERING LOCUS C Transcription via Chromatin Remodeling under Short-Term Cold Stress in Arabidopsis.
Plant Cell
PUBLISHED: 11-12-2013
Show Abstract
Hide Abstract
Exposure to short-term cold stress delays flowering by activating the floral repressor FLOWERING LOCUS C (FLC) in Arabidopsis thaliana. The cold signaling attenuator HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE1 (HOS1) negatively regulates cold responses. Notably, HOS1-deficient mutants exhibit early flowering, and FLC expression is suppressed in the mutants. However, it remains unknown how HOS1 regulates FLC expression. Here, we show that HOS1 induces FLC expression by antagonizing the actions of FVE and its interacting partner histone deacetylase 6 (HDA6) under short-term cold stress. HOS1 binds to FLC chromatin in an FVE-dependent manner, and FVE is essential for the HOS1-mediated activation of FLC transcription. HOS1 also interacts with HDA6 and inhibits the binding of HDA6 to FLC chromatin. Intermittent cold treatments induce FLC expression by activating HOS1, which attenuates the activity of HDA6 in silencing FLC chromatin, and the effects of intermittent cold are diminished in hos1 and fve mutants. These observations indicate that HOS1 acts as a chromatin remodeling factor for FLC regulation under short-term cold stress.
Related JoVE Video
Application of the multiplex cytokine analysis to monitor xenogeneic immune responses to the porcine islet graft in non-human primate.
J. Korean Med. Sci.
PUBLISHED: 11-04-2013
Show Abstract
Hide Abstract
Non-human primate studies must be conducted prior to the clinical trial of xenotransplantation. In order to develop clinically applicable immune-modulatory regimen through non-human primate studies, close monitoring of xenogeneic immune responses is required. We adopted multiplex cytokine analysis in assessment of the immune status during the course of pig-to-non-human primate islet transplantation. This study aimed to assess the feasibility of this multiplex cytokine assay in the development of immune-modulatory regimen. Using this assay, we were able to detect different cytokines with a minimal usage of blood samples, and this allowed us to detect various immunological situations in the recipients. Detection of TNF-? surge (347.8 pg/mL) guided us to block TNF-? in the early phase of transplantation. Supportive information for in vivo efficacy of cytokine neutralizing antibody could be speculated by in vitro neutralization assay (1,250 pg/mL ? 0 pg/mL). In addition, periodic monitoring of cytokines in peripheral blood allowed the detection of the infection episode prior to other routine assays. These benefits of multiplex cytokine assay may be generally applied to other pre-clinical research, which is a prerequisite for clinical trials.
Related JoVE Video
Role of regulatory T cells in transferable immunological tolerance to bone marrow donor in murine mixed chimerism model.
J. Korean Med. Sci.
PUBLISHED: 11-04-2013
Show Abstract
Hide Abstract
Constructing a bone marrow chimera prior to graft transplantation can induce donor-specific immune tolerance. Mixed chimerism containing hematopoietic cells of both recipient- and donor-origin has advantages attributed from low dose of total body irradiation. In this study, we explored the mechanism of mixed chimerism supplemented with depletion of Natural Killer cells. Mixed chimerism with C57BL/6 bone marrow cells was induced in recipient BALB/c mice which were given 450 cGy of ?-ray irradiation (n = 16). As revealed by reduced proliferation and cytokine production in mixed leukocyte reaction and ELISpot assay (24.6 vs 265.5), the allo-immune response to bone marrow donor was reduced. Furthermore, the induction of transferable immunological tolerance was confirmed by adoptive transfer and subsequent acceptance of C57BL/6 skin graft (n = 4). CD4(+)FoxP3(+) regulatory T cells were increased in the recipient compartment of the mixed chimera (19.2% ? 33.8%). This suggests that regulatory T cells may be therapeutically used for the induction of graft-specific tolerance by mixed chimerism.
Related JoVE Video
Luteolin and luteolin-7-O-glucoside strengthen antioxidative potential through the modulation of Nrf2/MAPK mediated HO-1 signaling cascade in RAW 264.7 cells.
Food Chem. Toxicol.
PUBLISHED: 09-17-2013
Show Abstract
Hide Abstract
It has been understood that glycosidic forms of flavonoids were hydrolyzed by gut bacteria and absorbed as aglycones. However, several reports suggested that glycosides were partly absorbed without hydrolysis and remained biologically active. In this study, we evaluated the antioxidative potential of luteolin and luteolin-7-O-glucoside, glycosidic form of luteolin, against the oxidative damage and compared their antioxidative mechanisms in RAW 264.7 cells. Heme oxygenase-1 (HO-1), one of the phase II enzymes showing an antioxidative activity, was potently induced by luteolin and luteolin-7-O-glucoside treatment, which was in accordance with the translocated nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) into nucleus. Moreover, luteolin and the luteolin-7-O-glucoside activated HO-1 expression by p38 and c-Jun NH2-terminal kinase (JNK) regulation. In order to identify the antioxidation potential by HO-1, tert-butyl hydroperoxide (t-BHP)-induced oxidative damage was applied and ameliorated by luteolin and the luteolin-7-O-glucoside treatment in a dose dependent manner, which was confirmed by HO-1 selective inhibitor and inducer, tin protoporphyrin (SnPP) and cobalt protoporphyrin (CoPP), respectively. Consequently, luteolin and luteolin-7-O-glucoside potently strengthen the HO-1-mediated antioxidative potential through the modulation of the Nrf2/MAPK signaling pathways.
Related JoVE Video
The Arabidopsis Floral Repressor BFT Delays Flowering by Competing with FT for FD Binding under High Salinity.
Mol Plant
PUBLISHED: 08-10-2013
Show Abstract
Hide Abstract
Soil salinity is one of the most serious agricultural problems that significantly reduce crop yields in the arid and semi-arid regions. It influences various phases of plant growth and developmental processes, such as seed germination, leaf and stem growth, and reproductive propagation. Salt stress delays the onset of flowering in many plant species. We have previously reported that the Arabidopsis BROTHER OF FT AND TFL1 (BFT) acts as a floral repressor under salt stress. However, the molecular mechanisms underlying the BFT function in the salt regulation of flowering induction is unknown. In this work, we found that BFT delays flowering under high salinity by competing with FLOWERING LOCUS T (FT) for binding to the FD transcription factor. The flowering time of FD-deficient fd-2 mutant was insensitive to high salinity. BFT interacts with FD in the nucleus via the C-terminal domain of FD, which is also required for the interaction of FD with FT, and interferes with the FT-FD interaction. These observations indicate that BFT constitutes a distinct salt stress signaling pathway that modulates the function of the FT-FD module and possibly provides an adaptation strategy that fine-tunes photoperiodic flowering under high salinity.
Related JoVE Video
Synthesis and evaluation of phosphorodithioate-based hydrogen sulfide donors.
Mol Biosyst
PUBLISHED: 08-07-2013
Show Abstract
Hide Abstract
A series of O-aryl- and alkyl-substituted phosphorodithioates were designed and synthesized as hydrogen sulfide (H2S) donors. H2S releasing capability of these compounds was evaluated using fluorescence methods. O-aryl substituted donors showed slow and sustained H2S release while O-alkylated compounds showed very weak H2S releasing capability. We also evaluated donors protective effects against hydrogen peroxide (H2O2)-induced oxidative damage in myocytes and donors toxicity toward B16BL6 mouse melanoma cells.
Related JoVE Video
Detection of Protein S-Sulfhydration by a Tag-Switch Technique.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 07-06-2013
Show Abstract
Hide Abstract
Protein S-sulfhydration (forming -S-SH adducts from cysteine residues) is a newly defined oxidative posttranslational modification and plays an important role in H2 S-mediated signaling pathways. In this study we report the first selective, "tag-switch" method which can directly label protein S-sulfhydrated residues by forming stable thioether conjugates. Furthermore we demonstrate that H2 S alone cannot lead to S-sulfhydration and that the two possible physiological mechanisms include reaction with protein sulfenic acids (P-SOH) or the involvement of metal centers which would facilitate the oxidation of H2 S to HS(.) .
Related JoVE Video
Comparative analysis of mesenchymal stem cell surface marker expression for human dental mesenchymal stem cells.
Regen Med
PUBLISHED: 07-06-2013
Show Abstract
Hide Abstract
Human dental mesenchymal stem cells (hDMSCs) have been isolated from extracted human teeth and proven to have different proliferation and differentiation abilities among the subtypes. Despite increasing interest in the clinical use of hDMSCs, a well-defined specific marker has been absent for these stem cells. In this study, a comparative analysis with known mesenchymal stem cell surface markers such as STRO-1, CD90, CD146, CD34 and TfR (CD71) was performed.
Related JoVE Video
Light-induced hydrogen sulfide release from "caged" gem-dithiols.
Org. Lett.
PUBLISHED: 05-22-2013
Show Abstract
Hide Abstract
"Caged" gem-dithiol derivatives that release H2S upon light stimulation have been developed. This new class of H2S donors was proven, by various spectroscopic methods, to generate H2S in an aqueous/organic medium as well as in cell culture.
Related JoVE Video
Should lamivudine monotherapy be stopped or continued in patients infected with hepatitis B with favorable responses after more than 5 years of treatment?
J. Med. Virol.
PUBLISHED: 04-18-2013
Show Abstract
Hide Abstract
Regarding the limited evidence for determining the optimal duration of antiviral treatment for hepatitis B, the long-term outcome of patients with favorable responses to over 5 years of lamivudine monotherapy was investigated. Two hundred seventy-one patients who had received lamivudine for at least 5 years were enrolled. Ultimately, 72 patients without YMDD mutations and showing hepatitis B virus (HBV) DNA levels <2.5 pg/ml after 5 years of treatment were analyzed. Mean treatment duration with lamivudine was 9.1 ± 2.6 years. During the treatment, HBeAg and HBsAg loss/seroconversion rates were 95 and 6.9%, respectively. Decompensation and hepatocellular carcinoma (HCC) developed in 2.8 and 6.9% of patients, respectively. Old age and cirrhosis were risk factors for HCC development. Finally, 11.1% of patients developed YMDD mutations after 8.3 ± 2.4 years of treatment. There was no hepatic decompensation among the patients who developed delayed YMDD mutations. Sixteen patients who achieved a complete response stopped lamivudine and four patients showed relapses 10.3 ± 8.5 months after stopping lamivudine. Relapsed patients had more cirrhotic livers and higher rates of HBeAg positivity at 5 years than patients who maintained complete response. The present study suggests that patients who do not develop YMDD mutations over 5 years of treatment with lamivudine may continue lamivudine monotherapy until the loss of HBsAg. However, even for the patients showing favorable response over 5 years of treatment, those in older ages, with cirrhosis or who show poor HBeAg responses should be on careful monitoring to detect the development of viral mutations, relapse and even HCC.
Related JoVE Video
Luteolin and luteolin-7-O-glucoside inhibit lipopolysaccharide-induced inflammatory responses through modulation of NF-?B/AP-1/PI3K-Akt signaling cascades in RAW 264.7 cells.
Nutr Res Pract
PUBLISHED: 04-09-2013
Show Abstract
Hide Abstract
Luteolin is a flavonoid found in abundance in celery, green pepper, and dandelions. Previous studies have shown that luteolin is an anti-inflammatory and anti-oxidative agent. In this study, the anti-inflammatory capacity of luteolin and one of its glycosidic forms, luteolin-7-O-glucoside, were compared and their molecular mechanisms of action were analyzed. In lipopolysaccharide (LPS)-activated RAW 264.7 cells, luteolin more potently inhibited the production of nitric oxide (NO) and prostaglandin E2 as well as the expression of their corresponding enzymes (inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) than luteolin-7-O-glucoside. The molecular mechanisms underlying these effects were investigated to determine whether the inflammatory response was related to the transcription factors, nuclear factor (NF)-?B and activator protein (AP)-1, or their upstream signaling molecules, mitogen-activated protein kinases (MAPKs) and phosphoinositide 3-kinase (PI3K). Luteolin attenuated the activation of both transcription factors, NF-?B and AP-1, while luteolin-7-O-glucoside only impeded NF-?B activation. However, both flavonoids inhibited Akt phosphorylation in a dose-dependent manner. Consequently, luteolin more potently ameliorated LPS-induced inflammation than luteolin-7-O-glucoside, which might be attributed to the differentially activated NF-?B/AP-1/PI3K-Akt pathway in RAW 264.7 cells.
Related JoVE Video
Ethical and regulatory guidelines in clinical trials of xenocorneal transplantation in Korea; the Korean xenocorneal transplantation consensus statement.
Xenotransplantation
PUBLISHED: 04-09-2013
Show Abstract
Hide Abstract
To establish the consensus about the conditions for undertaking clinical trials in xenocorneal transplantation in Korea, specific issues regarding the xenocorneal transplantation on ethical and regulatory aspects are addressed, and the guidelines to conduct clinical trial of the xenocorneal transplantation are proposed.
Related JoVE Video
Controlled turnover of CONSTANS protein by the HOS1 E3 ligase regulates floral transition at low temperatures.
Plant Signal Behav
PUBLISHED: 02-20-2013
Show Abstract
Hide Abstract
The timing of flowering is coordinately regulated by complex gene regulatory networks that integrate developmental and environmental cues. Light and temperature are major environmental determinants in flowering time control. Temperature signals include two major categories: ambient temperature signals and cold nonfreezing temperature signals. Notably, the effects of cold temperatures on flowering timing are profoundly differentiated, depending on the duration of cold exposure. Whereas long-term exposure to cold temperatures, designated vernalization, promotes flowering, short-term cold exposure delays flowering. Genes constituting the vernalization pathway and underlying molecular mechanisms have been extensively studied. However, how cold stress signals delay flowering is largely unknown. We have recently reported that the HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE 1 (HOS1)-CONSTANS (CO) module is at least partly responsible for the daily sensing of cold stress signals in flowering time control. Intermittent cold stress triggers the degradation of CO, a central activator of photoperiodic flowering, via a ubiquitination pathway that involves the HOS1 E3 ubiquitin ligase, leading to suppression of FLOWERING LOCUS T (FT) gene and delayed flowering. It is proposed that CO serves as a molecular knot that integrates photoperiod and temperature signals into the flowering pathways, fine-tuning photoperiodic flowering under short-term temperature fluctuations.
Related JoVE Video
Natural variation in floral nectar proteins of two Nicotiana attenuata accessions.
BMC Plant Biol.
PUBLISHED: 02-19-2013
Show Abstract
Hide Abstract
Floral nectar (FN) contains not only energy-rich compounds to attract pollinators, but also defense chemicals and several proteins. However, proteomic analysis of FN has been hampered by the lack of publically available sequence information from nectar-producing plants. Here we used next-generation sequencing and advanced proteomics to profile FN proteins in the opportunistic outcrossing wild tobacco, Nicotiana attenuata.
Related JoVE Video
Relationship between bone mineral density and moderate to severe chronic kidney disease among general population in Korea.
J. Korean Med. Sci.
PUBLISHED: 01-25-2013
Show Abstract
Hide Abstract
Recent studies in Western countries have reported a significant association between glomerular filtration rate (GFR) and bone mineral density (BMD) in the absence of dialysis among the general population. However, there have been few studies regarding renal function and BMD among Korean or Asian subjects with moderate to severe (stage 3 or 4) chronic kidney disease (MS-CKD). The aim of the present study was to investigate the association between MS-CKD and BMD in the general Korean population. BMD, serum creatinine and other measures were obtained from 3,190 subjects (1,428 males and 1,762 females; the fourth Korean National Health and Nutrition Examination Survey). GFR was estimated using the Cockcroft-Gault formula, with adjustment for body surface area. After adjustment for all variables, multiple regression analysis showed that BMD in the femur neck, total femur and lumbar spine were positively associated with eGFR in both males and females. Additional analysis showed that MS-CKD was also significantly associated with osteoporosis in both males and females (odds ratio [OR] 2.20, 95% confidence interval [CI] 1.15-4.20 in males; and OR 1.96, 95% CI 1.33-2.88 in females). Individuals with MS-CKD may be at higher risk of osteoporosis even among Asians.
Related JoVE Video
A pilot study of autologous CD34-depleted bone marrow mononuclear cell transplantation via the hepatic artery in five patients with liver failure.
Cytotherapy
PUBLISHED: 01-21-2013
Show Abstract
Hide Abstract
Many rodent experiments and human studies on stem cell therapy have shown promising therapeutic approaches to liver diseases. We investigated the clinical outcomes of five patients with liver failure of various causes who received autologous CD34-depleted bone marrow-derived mononuclear cell (BM-MNC) transplantation, including mesenchymal stromal cells, through the hepatic artery.
Related JoVE Video
Functional Characteristics of C-terminal Lysine to Cysteine Mutant Form of CTLA-4Ig.
Immune Netw
PUBLISHED: 01-21-2013
Show Abstract
Hide Abstract
CTLA-4Ig is regarded as an inhibitory agent of the T cell proliferation via blocking the costimulatory signal which is essential for full T cell activation. To improve applicability, we developed the CTLA-4Ig-CTKC in which the c-terminal lysine had been replaced by cysteine through single amino acid change. The single amino acid mutation of c-terminus of CTLA-4Ig was performed by PCR and was checked by in vitro transcription and translation. DNA construct of mutant form was transfected to Chinese hamster ovary (CHO) cells by electroporation. The purified proteins were confirmed by Western blot and B7-1 binding assay for their binding ability. The suppressive capacity of CTLA-4Ig-CTKC was evaluated by the mixed lymphocyte reaction (MLR) and in the allogeneic pancreatic islet transplantation model. CTLA-4Ig-CTKC maintained binding ability to B7-1 molecule and effectively inhibits T cell proliferation in MLR. In the murine allogeneic pancreatic islet transplantation, short-term treatment of CTLA-4Ig-CTKC prolonged the graft survival over 100 days. CTLA-4Ig-CTKC effectively inhibits immune response both in MLR and in allogeneic islet transplantation model, indicating that single amino acid mutation does not affect the inhibitory function of CTLA-4Ig. CTLA-4Ig-CTKC can be used in vehicle-mediated drug delivery system such as liposome conjugation.
Related JoVE Video
Clinical factors predictive of insufficient liver enhancement on the hepatocyte-phase of Gd-EOB-DTPA-enhanced magnetic resonance imaging in patients with liver cirrhosis.
J. Gastroenterol.
PUBLISHED: 01-11-2013
Show Abstract
Hide Abstract
Estimating liver parenchymal enhancement prior to gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) imaging is crucial to accurate detection and characterization of focal hepatic lesions. We aimed to clarify the factors predictive of liver enhancement in a relatively large sample of patients.
Related JoVE Video
Alternative splicing of transcription factors in plant responses to low temperature stress: mechanisms and functions.
Planta
PUBLISHED: 01-08-2013
Show Abstract
Hide Abstract
Transcription factors play a central role in the gene regulatory networks that mediate various aspects of plant developmental processes and responses to environmental changes. Therefore, their activities are elaborately regulated at multiple steps. In particular, accumulating evidence illustrates that post-transcriptional control of mRNA metabolism is a key molecular scheme that modulates the transcription factor activities in plant responses to temperature fluctuations. Transcription factors have a modular structure consisting of distinct protein domains essential for DNA binding, dimerization, and transcriptional regulation. Alternative splicing produces multiple proteins having different structural domain compositions from a single transcription factor gene. Recent studies have shown that alternative splicing of some transcription factor genes generates small interfering peptides (siPEPs) that negatively regulate the target transcription factors via peptide interference (PEPi), constituting self-regulatory circuits in plant cold stress response. A number of splicing factors, which are involved in RNA binding, splice site selection, and spliceosome assembly, are also affected by temperature fluctuations, supporting the close association of alternative splicing of transcription factors with plant responses to low temperatures. In this review, we summarize recent progress on the temperature-responsive alternative splicing of transcription factors in plants with emphasis on the siPEP-mediated PEPi mechanism.
Related JoVE Video
Using the developmental gene bicoid to identify species of forensically important blowflies (Diptera: calliphoridae).
Biomed Res Int
PUBLISHED: 01-07-2013
Show Abstract
Hide Abstract
Identifying species of insects used to estimate postmortem interval (PMI) is a major subject in forensic entomology. Because forensic insect specimens are morphologically uniform and are obtained at various developmental stages, DNA markers are greatly needed. To develop new autosomal DNA markers to identify species, partial genomic sequences of the bicoid (bcd) genes, containing the homeobox and its flanking sequences, from 12 blowfly species (Aldrichina grahami, Calliphora vicina, Calliphora lata, Triceratopyga calliphoroides, Chrysomya megacephala, Chrysomya pinguis, Phormia regina, Lucilia ampullacea, Lucilia caesar, Lucilia illustris, Hemipyrellia ligurriens and Lucilia sericata; Calliphoridae: Diptera) were determined and analyzed. This study first sequenced the ten blowfly species other than C. vicina and L. sericata. Based on the bcd sequences of these 12 blowfly species, a phylogenetic tree was constructed that discriminates the subfamilies of Calliphoridae (Luciliinae, Chrysomyinae, and Calliphorinae) and most blowfly species. Even partial genomic sequences of about 500 bp can distinguish most blowfly species. The short intron 2 and coding sequences downstream of the bcd homeobox in exon 3 could be utilized to develop DNA markers for forensic applications. These gene sequences are important in the evolution of insect developmental biology and are potentially useful for identifying insect species in forensic science.
Related JoVE Video
Islet isolation from adult designated pathogen-free pigs: use of the newer bovine nervous tissue-free enzymes and a revised donor selection strategy would improve the islet graft function.
Xenotransplantation
PUBLISHED: 12-16-2011
Show Abstract
Hide Abstract
In clinical trials using adult porcine islet products, islets should be isolated from the designated pathogen-free (DPF) pigs under the current good manufacturing practice (GMP) regulations. Our previous studies suggested that male DPF pigs are better donors than retired breeder pigs and histomorphometrical parameters of donor pancreas predict the porcine islet quality. We aimed to investigate whether the use of the newer bovine nervous tissue-free enzymes and a revised donor selection strategy could improve the islet graft function in the context of islet isolation with DPF pigs.
Related JoVE Video
Aziridine-mediated ligation and site-specific modification of unprotected peptides.
J. Am. Chem. Soc.
PUBLISHED: 11-23-2011
Show Abstract
Hide Abstract
A synthesis of aziridine-containing peptides via the Cu(II)-promoted coupling of unprotected peptide thioacids and N-H aziridine-2-carbonyl peptides is reported. The unique reactivity of the resulting N-acylated aziridine-2-carbonyl peptides facilitates their subsequent regioselective and stereoselective nucleophilic ring-opening to give unprotected peptides that are specifically modified at the ligation site. The aziridine-mediated peptide ligation concept is exemplified using H(2)O as the nucleophile, producing a Xaa-Thr linkage (where Xaa can be an epimerizable and hindered amino acid). The overall process is compatible with a variety of unprotected amino acid functionality, most notably the N-terminal and Lys side chain amines.
Related JoVE Video
The SOC1-SPL module integrates photoperiod and gibberellic acid signals to control flowering time in Arabidopsis.
Plant J.
PUBLISHED: 11-16-2011
Show Abstract
Hide Abstract
miR156 and its target SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) genes constitute an endogenous flowering pathway in Arabidopsis. The SPL genes are regulated post-transcriptionally by miR156, and incorporate endogenous aging signals into floral gene networks. Intriguingly, the SPL genes are also regulated transcriptionally by FLOWERING LOCUS T (FT)-mediated photoperiod signals. However, it is unknown how photoperiod regulates the SPL genes. Here, we show that SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) and FT regulate the SPL3, SPL4 and SPL5 genes by directly binding to the gene promoters in response to photoperiod signals. Notably, the SOC1 regulation of the SPL genes, termed the SOC1-SPL module, also mediates gibberellic acid (GA) signals to promote flowering under non-inductive short days (SDs). Under SDs, the inductive effects of GA on the SPL genes disappeared in the soc1-2 mutant, and the flowering of SPL3-overexpressing transgenic plants (35S:SPL3) was less sensitive to GA. In addition, the 35S:SPL3 × soc1-2 plants flowered much earlier than the soc1-2 mutant, supporting SOC1 regulation of the SPL genes. Our observations indicate that the SOC1-SPL module serves as a molecular link that integrates photoperiod and GA signals to promote flowering in Arabidopsis.
Related JoVE Video
In situ induction of dendritic cell-based T cell tolerance in humanized mice and nonhuman primates.
J. Exp. Med.
PUBLISHED: 10-24-2011
Show Abstract
Hide Abstract
Induction of antigen-specific T cell tolerance would aid treatment of diverse immunological disorders and help prevent allograft rejection and graft versus host disease. In this study, we establish a method of inducing antigen-specific T cell tolerance in situ in diabetic humanized mice and Rhesus monkeys receiving porcine islet xenografts. Antigen-specific T cell tolerance is induced by administration of an antibody ligating a particular epitope on ICAM-1 (intercellular adhesion molecule 1). Antibody-mediated ligation of ICAM-1 on dendritic cells (DCs) led to the arrest of DCs in a semimature stage in vitro and in vivo. Ablation of DCs from mice completely abrogated anti-ICAM-1-induced antigen-specific T cell tolerance. T cell responses to unrelated antigens remained unaffected. In situ induction of DC-mediated T cell tolerance using this method may represent a potent therapeutic tool for preventing graft rejection.
Related JoVE Video
Synergistic effect of tetrandrine and ethidium bromide against methicillin-resistant Staphylococcus aureus (MRSA).
J Toxicol Sci
PUBLISHED: 10-20-2011
Show Abstract
Hide Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) along with other resistant bacteria have become a significant social and clinical problem. Therefore, there is an urgent need to develop bioactive compounds from natural products as alternatives to the very few antibiotics that remain effective. Recently, the efflux mechanism has been identified as the main contributor to antibiotic resistance in bacteria. This study therefore aimed to evaluate tetrandrine (TET), an efflux pump inhibitor (EPI), as a potential antibiotic against MRSA. We investigated the antimicrobial activity of TET against 17 MRSA strains, of which 3 selected strains were studied in further detail using a time-kill assay. When these bacterial strains (1 × 10(6) colony-forming units (cfu)/ml) were incubated with TET in a time-kill assay, log-scale bactericidal activity was observed, which lasted for 24 hr. In addition, TET exhibits a synergistic effect when combined with the multi-drug resistance (MDR)-efflux pump substrate ethidium bromide (EtBr). Structure-function studies of the antibiotic activity of TET in combination with EtBr may lead to the discovery of more effective efflux pump inhibitors.
Related JoVE Video
Influence of Interferon-? Deficiency in Immune Tolerance Induced by Male Islet Transplantation.
Immune Netw
PUBLISHED: 10-04-2011
Show Abstract
Hide Abstract
Traditionally, interferon-? (IFN-?) was regarded as a pro-inflammatory cytokine, however, recent reports suggested role of IFN-? in immune tolerance. In our previous report, we could induce tolerance to male antigen (HY) just by male islet transplantation in wild type C57BL/6 mice without any immunological intervention. We tried to investigate the influence of IFN-? deficiency on tolerance induction by male islet transplantation.
Related JoVE Video
Signaling linkage between environmental stress resistance and leaf senescence in Arabidopsis.
Plant Signal Behav
PUBLISHED: 10-01-2011
Show Abstract
Hide Abstract
Plants possess versatile strategies that permit efficient use of limited nutrient resources during senescing process. This metabolic adjustment is critical for prevention of diverse cellular damage and thus for reproductive success and offspring production, particularly under environmental stress conditions. However, it is largely unknown how age-dependent resistance to cellular damages is established and how it is influenced by environmental stress signals during senescing process. We found that the VNI2 (VND-INTERACTING 2) transcription factor, which belongs to the NAC (NAM/ATAF1, 2/CUC2) transcription factor family, plays a role in the age-dependent induction of stress resistance. The VNI2 transcription factor is transcriptionally induced during senescing process and regulates COR/RD genes by binding directly to their promoters. The COR/RD proteins play a role in the protection from diverse cellular damages during senescing process. Notably, the transcriptional activation activity of VNI2 is further elevated under high salinity. These results indicate that plants increase environmental stress resistance by inducing the VNI2 gene to assure their reproductive success, supporting signaling crosstalk between stress resistance response and senescing process. 
Related JoVE Video
Murine mesenchymal stem cells suppress T lymphocyte activation through IL-2 receptor ? (CD25) cleavage by producing matrix metalloproteinases.
Stem Cell Rev
PUBLISHED: 10-01-2011
Show Abstract
Hide Abstract
Mesenchymal stem cells (MSCs) are multipotent, non-hematopoietic stem cells that exhibit the capacity to inhibit the proliferation of a variety of immune cells. However, the underlying mechanisms of the immunosuppressive effects of MSCs are still obscure. Therefore, we attempted to identify the mechanisms underlying immunosuppression toward the activated T lymphocytes by MSCs in a murine model. In particular, we aimed to find possible factors derived from MSCs that drive this phenomenon. We found that T lymphocytes incubated with conditioned media of MSCs (MSC CM) entered into apoptosis and were subjected to cell cycle arrest during the course of activation, and these phenomena were accompanied by the reduction of IL-2 production. Specifically, matrix metalloproteinases (MMPs) derived from MSCs caused cleavage of IL-2 receptor ? (CD25) from the surface of activated T cells, and as a consequence, IL-2 signaling in response to engagement of the IL-2 receptor (IL-2R) was downregulated. The inhibition of MMP activity in the MSC CM by GM6001 abrogated CD25 cleavage and restored IL-2 production from the activated splenocytes. However, the blockade of MMP activity could not fully restore the proliferative response and apoptosis of T cells altered by MSC CM. In conclusion, MSC-derived MMPs have a significant role in the suppression of IL-2 production through induction of CD25 cleavage and have a partial role in the suppression of T cell proliferation.
Related JoVE Video
RPL36 as a prognostic marker in hepatocellular carcinoma.
Pathol. Int.
PUBLISHED: 09-23-2011
Show Abstract
Hide Abstract
Ribosomal proteins (RP) play key roles in the regulation of apoptosis, multidrug resistance and carcinogenesis. The aim of this study was to investigate the expression of ribosomal protein L36 (RPL36) in hepatocellular carcinoma (HCC) and to correlate it with clinicopathological parameters and clinical outcome. Liver specimens were obtained from 60 HCC patients who had undergone a partial hepatectomy. Expression of RPL36 in tumor tissue and surrounding non-tumorous tissues was evaluated on a tissue microarray by immunohistochemistry. RPL36 was expressed in 45 of 60 (75%) HCC by immunohistochemistry, but was not detected in corresponding non-tumors. RPL36 expression correlated significantly with serum levels of albumin (P= 0.044) and prothrombin time (P= 0.026), which reflect liver synthetic function. Moreover, expression of RPL36 was found to be higher in patients with early tumor stages (I/II) (P= 0.038) or without portal vein thrombosis (P= 0.005). In univariate analysis, patients with RPL36 expression revealed better overall survival (P= 0.037). By multivariate survival analysis, RPL36 expression was found to be an independent prognostic factor for overall survival (P= 0.026). Our data suggest that RPL36 may be involved in the early stage of hepatocarcinogenesis, and it can be used as an independent and potential prognostic marker for resected HCC.
Related JoVE Video
Shigella flexneri infection in a newly acquired rhesus macaque (Macaca mulatta).
Lab Anim Res
PUBLISHED: 09-19-2011
Show Abstract
Hide Abstract
A 3.4 year-old rhesus macaque weighing 4.5 kg, was suffering from anorexia, acute mucous and bloody diarrhea. On physical examination, the monkey showed a loss of activity, hunched posture, abdominal pain, dehydration, mild gingivitis and unclean anus with discharge. Whole blood was collected for the examination of electrolytes, hematology and serum chemistry; fresh stool was also collected for bacterial culture. Blood profiles showed leukocytosis (14.5 K/µL) and neutrophilia (11.0 K/µL) on complete blood cell count and imbalanced electrolytes associated with diarrhea. As a result of bacterial culture, Shigella flexneri was identified through Mac/SS, IMVIC test, TCBS and VITEK II. Based on these results, this monkey was diagnosed as having acute enteritis caused by Shigella flexneri. Treatment was performed with enrofloxacin prior to the isolation of Shigella flexneri to prevent the transmission of disease. Fortunately, mucus and bloody diarrhea did not persist and general conditions fully recovered. Our results show that the use of enrofloxacin is effective in controlling Shigella flexneri infection in newly acquired rhesus monkeys.
Related JoVE Video
Activation of a flavin monooxygenase gene YUCCA7 enhances drought resistance in Arabidopsis.
Planta
PUBLISHED: 08-23-2011
Show Abstract
Hide Abstract
Auxin regulates diverse molecular and physiological events at the cellular and organismal levels during plant growth and development in response to environmental stimuli. It acts either through distinct signaling pathways or in concert with other growth hormones. Its biological functions are adjusted by modulating biosynthesis, conjugate formation, and polar transport and distribution. Several tryptophan-dependent and -independent auxin biosynthetic pathways have been proposed. Recent studies have shown that a few flavin monooxygenase enzymes contribute to the tryptophan-dependent auxin biosynthesis. Here, we show that activation of a flavin monooxygenase gene YUCCA7 (YUC7), which belongs to the tryptophan-dependent auxin biosynthetic pathway, enhances drought resistance. An Arabidopsis activation-tagged mutant yuc7-1D exhibited phenotypic changes similar to those observed in auxin-overproducing mutants, such as tall, slender stems and curled, narrow leaves. Accordingly, endogenous levels of total auxin were elevated in the mutant. The YUC7 gene was induced by drought, primarily in the roots, in an abscisic acid (ABA)-dependent manner. The yuc7-1D mutant was resistant to drought, and drought-responsive genes, such as RESPONSIVE TO DESSICATION 29A (RD29A) and COLD-REGULATED 15A (COR15A), were up-regulated in the mutant. Interestingly, whereas stomatal aperture and production of osmoprotectants were not discernibly altered, lateral root growth was significantly promoted in the yuc7-1D mutant when grown under drought conditions. These observations support that elevation of auxin levels in the roots enhances drought resistance possibly by promoting root growth.
Related JoVE Video
Auxin modulation of salt stress signaling in Arabidopsis seed germination.
Plant Signal Behav
PUBLISHED: 08-01-2011
Show Abstract
Hide Abstract
Seed germination is an elaborate developmental process that is regulated through intricate signaling networks integrating diverse environmental cues into endogenous hormonal signaling pathways. Accumulating evidence in recent years supports the role of auxin in seed germination. Whereas the roles of gibberellic acid (GA) and abscisic acid (ABA) in the germination process have been studied extensively, how auxin modulates seed germination is largely unknown. We found that a membrane-bound NAC transcription factor NTM2 mediates the signaling crosstalk between auxin and salt stress via the IAA30 gene during seed germination in Arabidopsis. Germination of the NTM2-deficient ntm2-1 mutant seeds exhibited enhanced resistance to high salinity. However, the salt resistance was reduced in the ntm2-1 mutant overexpressing the IAA30 gene, which was induced by high salinity in a NTM2-dependent manner. Exogenous auxin treatment further suppressed the reduced germination rate of control seeds under high salinity. In contrast, the auxin effects disappeared in the ntm2-1 mutant. These observations indicate that NTM2 is a molecular link that incorporates auxin signal into salt stress signaling during seed germination, providing a role of auxin in modulating seed germination under high salinity.
Related JoVE Video
Aurintricarboxylic acid promotes the conversion of naive CD4+CD25- T cells into Foxp3-expressing regulatory T cells.
Int. Immunol.
PUBLISHED: 07-12-2011
Show Abstract
Hide Abstract
Naive peripheral CD4(+)CD25(-) T cells can be converted into Foxp3-expressing regulatory T cells under appropriate stimulation conditions. Considering that continuous exposure to antigens is one of the prerequisites for the differentiation and maintenance of Treg cells, we investigated whether preventing activation-induced cell death while providing continuous TCR stimulation could promote the expression of Foxp3 in murine naive CD4(+) T cells. Among the several anti-apoptotic agents tested, aurintricarboxylic acid (ATA) was found to induce the in vitro conversion of naive CD4(+) T cells into Foxp3(+) Treg cells with suppressive activity. Neutralizing studies with an antibody against transforming growth factor (TGF)-? revealed that ATA requires the presence of TGF-? to induce Foxp3 expression in naive CD4(+)CD25(-) T cells. Although ATA itself did not activate the Smad signaling pathway, it down-regulated the extracellular signal-regulated kinase and mammalian target of rapamycin signaling cascade in activated T cells. Lastly, combined exposure to ATA and TGF-? had a synergistic effect on the rate of induction and maintenance of Foxp3 expression. These results indicate that ATA could be exploited to efficiently prepare inducible regulatory T cells in vitro and may aid in more precisely identifying the specific signaling pathways that drive Foxp3 expression in T cells.
Related JoVE Video
A rapid LC/MS/MS method for the analysis of nonvolatile antiinflammatory agents from Mentha?spp.
J. Food Sci.
PUBLISHED: 07-05-2011
Show Abstract
Hide Abstract
Mints (Mentha?spp.), aromatic crops grown largely for their essential oils, also are rich sources of nonvolatile antiinflammatory agents. Identification and quantitation of the constituents responsible for their antiinflammatory activity is challenging owing to the lack of suitable chromatographic methodology. In the present research, the simultaneous quantitation of antiinflammatory constituents rosmarinic acid, oleanolic acid, and ursolic acid in mints was attained by using a unique tandem HPLC column system coupled with an electrospray ionization mass detection (MRM mode). The ion mode optimization for rosmarinic acid under negative and triterpenoid acids under positive was achieved by setting 2 time segments in a single run where the polarity mode was switched from negative (0 to 10 min) to positive (10 to 40 min). For the investigated concentration ranges of antiinflammatory agents in mints, good linearities (r² ? 0.998) were obtained for each calibration curve. Validation of precision and accuracy for this method showed that intra- and inter-day repeatabilities for all analytes were less than 5.51%, and the recoveries varied from 97.8% to 99.3%. The developed LC/MS/MS assay provides a suitable quality control method for the determination of antiinflammatory constituents in?Mentha?spp. There is a wide range of diversity in the natural product composition for these acids across the?Mentha?germplasm collection evaluated. The presence of these antiinflammatory acids in post-distilled mints shows that value-added nutraceutical enriched products can be developed with proper processing and recovery systems in addition to the distillation and capture of the valuable volatile essential oils.
Related JoVE Video
Plaque rupture is a determinant of vascular events in carotid artery atherosclerotic disease: involvement of matrix metalloproteinases 2 and 9.
J Clin Neurol
PUBLISHED: 06-28-2011
Show Abstract
Hide Abstract
Unstable carotid atherosclerotic plaques are characterized by cap rupture, leading to thromboembolism and stroke. Matrix metalloproteinases (MMPs) have been implicated in the progression of atherosclerosis and plaque rupture. The aim of this study was to assess the relationship between the expressions of MMP-2 and MMP-9 and carotid plaque instability.
Related JoVE Video
Effect of ?Gal on corneal xenotransplantation in a mouse model.
Xenotransplantation
PUBLISHED: 06-24-2011
Show Abstract
Hide Abstract
It has been reported that hyperacute rejection (HAR) does not occur after pig-to-nonhuman corneal xenotransplantation. However, considering that immune privilege is already disrupted in most human corneal recipients, and the expression of ?Gal can be gradually reduced after pig-to-rat corneal transplantation, the long-term survival of corneal grafts from wild-type pigs cannot be guaranteed. Accordingly, we aimed to investigate the effect of ?Gal on the change in anti-Gal antibodies, using sensitized ?1,3-galactosyltransferase gene-knockout (GTKO) mice recipients.
Related JoVE Video
Frequency of killer cell immunoglobulin-like receptors (KIRs) in Korean patients with chronic HCV infection.
J. Korean Med. Sci.
PUBLISHED: 06-16-2011
Show Abstract
Hide Abstract
Natural killer (NK) cells play an important role in innate immunity, especially in the response to viral infections, such as hepatitis C virus (HCV). Killer cell immunoglobulin-like receptors (KIRs) are the primary receptors of NK cells that mediate innate immunity. KIRs are also involved in acquired immunity, because some KIRs are expressed on the surface of certain subsets of T cells. In this study, the frequency of KIR genes, HLA-C allotypes, and combinations of KIR genes with their HLA-C ligands were evaluated in two different groups of the Korean population: controls and patients with chronic HCV infection. The study population consisted of 147 Korean patients with chronic HCV infection. The frequency of KIR2DS2 in patients with chronic HCV infection was 9.5% which was significantly lower than 19.5% of the control (P < 0.01). However, there were no significant differences in the frequency of other KIR genes, HLA-C allotypes or different combinations of KIR genes with their HLA-C ligands. This study can contribute to the further prospective study with a larger scale, suggesting the assumption that KIR2DS2 might aid in HCV clearance by enhancing both the innate and acquired immune responses of people in Korea.
Related JoVE Video
The Arabidopsis NAC transcription factor VNI2 integrates abscisic acid signals into leaf senescence via the COR/RD genes.
Plant Cell
PUBLISHED: 06-14-2011
Show Abstract
Hide Abstract
Leaf aging is a highly regulated developmental process, which is also influenced profoundly by diverse environmental conditions. Accumulating evidence in recent years supports that plant responsiveness to abiotic stress is intimately related with leaf longevity. However, molecular mechanisms underlying the signaling crosstalks and regulatory schemes are yet unknown. In this work, we demonstrate that an abscisic acid (ABA)-responsive NAC transcription factor VND-INTERACTING2 (VNI2) integrates ABA-mediated abiotic stress signals into leaf aging by regulating a subset of COLD-REGULATED (COR) and RESPONSIVE TO DEHYDRATION (RD) genes. The VNI2 gene was induced by high salinity in an ABA-dependent manner. In addition, spatial and temporal expression patterns of the VNI2 gene are correlated with leaf aging and senescence. Accordingly, leaf aging was delayed in transgenic plants overexpressing the VNI2 gene but significantly accelerated in a VNI2-deficient mutant. The VNI2 transcription factor regulates the COR and RD genes by binding directly to their promoters. Notably, transgenic plants overexpressing the COR or RD genes exhibited prolonged leaf longevity. These observations indicate that the VNI2 transcription factor serves as a molecular link that integrates plant responses to environmental stresses into modulation of leaf longevity.
Related JoVE Video
Endoscopic submucosal dissection of gastric neoplasia involving the pyloric channel by retroflexion in the duodenum.
Dig. Dis. Sci.
PUBLISHED: 06-10-2011
Show Abstract
Hide Abstract
Tumors involving the pyloric channel have been considered as difficult lesions for successful endoscopic resection. We studied the feasibility of endoscopic submucosal dissection (ESD) using retroflexion in the duodenum to resect the gastric neoplasia involving the pyloric channel.
Related JoVE Video
The mechanism of action of sanguinarine against methicillin-resistant Staphylococcus aureus.
J Toxicol Sci
PUBLISHED: 06-02-2011
Show Abstract
Hide Abstract
Sanguinarine is a benzophenanthridine alkaloid derived from the root of Sanguinaria canadensis. It is known to perform a wide spectrum of biological activities. The aim of this study is to examine the antimicrobial actions of sanguinarine against methicillin-resistant Staphylococcus aureus (MRSA). Sanguinarine antimicrobial activity was assessed by broth dilution method; its mechanism of action was investigated by bacteriolysis, detergent or ATPase inhibitors and transmission electron microscopy were used to monitor the survival characteristics and the changes in bacteria morphology. The activity of sanguinarine against MRSA strains ranged from 3.12 to 6.25 µg/ml, while the minimum inhibitory concentrations of the two reference strains are 3.12 µg/ml and 1.56 µg/ml. The treatment of the cells with sanguinarine induced the release of membrane-bound cell wall autolytic enzymes, which eventually resulted in lysis of the cell. The OD(600s) of the suspensions treated with the combination of Tris-(hydroxymethyl) aminomethane and Triton X-100 with sanguinarine were reduced to 40% and 8%, respectively. Transmission electron microsco-py of MRSA treated with sanguinarine showed alterations in septa formation. The predisposition of lysis and the altered morphology seen by transmission electron microscopy suggest that sanguinarine compromises the cytoplasmic membrane.
Related JoVE Video
Sclerodermatous chronic graft-versus-host disease induced by host T-cell-mediated autoimmunity.
Immunol. Cell Biol.
PUBLISHED: 05-31-2011
Show Abstract
Hide Abstract
Despite a long-standing hypothesis that chronic graft-versus-host disease (cGVHD) is an autoimmune disorder, most mouse models of cGVHD have been developed on the assumption that donor T cells are essential for its development. Here we show that cGVHD may be caused by autoreactive host T cells in mice that have been lethally irradiated and grafted with T-cell-depleted allogeneic bone marrow cells. In this chimera, host T cells derived from radioresistant intrathymic T-cell precursors caused dermal fibrosis and periportal inflammation, without the requirement for donor T cells. The lack of host DCs within the thymus after high-dose irradiation allowed autoreactive host T cells to escape thymic negative selection. Moreover, the homeostatic expansion of these T cells may augment their autoreactivity. These findings indicate that host T-cell-mediated cGVHD is an autoimmune process that occurs following the grafting of T-cell-depleted BM cells into hosts with functioning thymuses. We propose, based on the present data, that host T-cell-dependent autoimmunity is a potential mechanism by which cGVHD is induced.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.