Project description:Although transmissible spongiform encephalopathies are thought to be mediated by the pathogenic isoform of the prion protein PrPSc, the molecular mechanism underlying neurodegeneration is poorly understood. MicroRNAs (miRNAs) have been shown to cause or influence the pathogenesis of several diseases, however, they were not linked to prion disorders yet. We have addressed the regulation of miRNAs in BSE-infected macaques as a model for human Creutzfeldt-Jacob disease. Applying miRNA microarrays and quantitative RT-PCR, we found that two miRNAs, hsa-miR-342 and hsa-miR-494, are upregulated in the brain of BSE-infected monkeys. Predictions of potential target genes revealed functional links to other neurodegenerative disorders with protein aggregation, including Alzheimer’s and Huntington’s disease. Differential miRNA analysis may be a powerful tool to identify common pathways in the pathogenesis of neurodegeneration.
Project description:The study describes miRNA expression in intact duodenum following chronic delta 9 tetrahydrocannabinol (Δ9-THC) administration to SIV-infected rhesus macaques. Chronic Δ9-THC administration to uninfected macaques significantly and positively modulated intestinal miRNA expression by increasing the total number of differentially expressed miRNAs from 14 to 60 days post infection (DPI). At 60DPI, ~28% of miRNAs showed decreased expression in VEH/SIV compared to none in the THC/SIV group. Furthermore, compared to the VEH/SIV group, THC selectively upregulated the expression of miR-10a, miR-24, miR-99b, miR-145, miR-149 and miR-187 previously shown to target proinflammatory molecules. NOX4, a potent reactive oxygen species generator was confirmed as a direct miR-99b target. A significant increase in NOX4+ crypt epithelial cells was detected in VEH/SIV compared to the THC/SIV group. We speculate that miR-99b-mediated NOX4 downregulation may protect the intestinal epithelium from oxidative stress-induced damage.
Project description:Background: Prion diseases such as bovine spongiform encephalopathies (BSE) are transmissible neurodegenerative diseases which are presumably caused by an infectious conformational isoform of the cellular prion protein. Previous work has provided evidence that in murine prion disease the endogenous retrovirus (ERV) expression is altered in the brain. To determine if prion-induced changes in ERV expression are a general phenomenon we used a non-human primate model for prion disease. Results: Cynomolgus macaques (Macaca fasicularis) were infected intracerebrally with BSE-positive brain stem material from cattle and allowed to develop prion disease. Brain tissue from the basis pontis and vermis cerebelli of the six animals and the same regions from four healthy controls were subjected to ERV expression profiling using a retrovirus-specific microarray and quantitative real-time PCR. We could show that Class I gammaretroviruses HERV-E4-1, ERV-9, and MacERV-4 increase expression in BSE-infected macaques. In a second approach, we analysed ERV-K-(HML-2) RNA and protein expression in extracts from the same cynomolgus macaques. Here we found a significant downregulation of both, the macaque ERV-K-(HML-2) Gag protein and RNA in the frontal/parietal cortex of BSE-infected macaques. Conclusions: We provide evidence that dysregulation of ERVs in response to BSE-infection can be detected on both, the RNA and the protein level. To our knowledge, this is the first report on the differential expression of ERV-derived structural proteins in prion disorders. Our findings suggest that endogenous retroviruses may induce or exacerbate the pathological consequences of prion-associated neurodegeneration. Cynomolgus macaques (Macaca fasicularis) were infected intracerebrally with BSE-positive brain stem material from cattle and allowed to develop prion disease. Brain tissue from the basis pontis and vermis cerebelli of the six animals and the same regions from four healthy controls were subjected to ERV expression profiling using a retrovirus-specific microarray and quantitative real-time PCR. In a second approach, ERV-K-(HML-2) RNA and protein expression was analysed in extracts from the same cynomolgus macaques.
Project description:We constructed a genome wide target profile of hsa-miR-503, hsa-miR-103, and hsa-miR-494 by sequencing RNA isolated from Ago2 immunoprecipitations and total RNA samples following transfection of the respective miRNA in mature duplex form Examination of mRNA levels in HeLa cells and Ago2 immunoprecipitations from HeLa cells following miR-503, miR-103, or miR-494 mature duplex or control siRNA transfection
Project description:Background: Prion diseases such as bovine spongiform encephalopathies (BSE) are transmissible neurodegenerative diseases which are presumably caused by an infectious conformational isoform of the cellular prion protein. Previous work has provided evidence that in murine prion disease the endogenous retrovirus (ERV) expression is altered in the brain. To determine if prion-induced changes in ERV expression are a general phenomenon we used a non-human primate model for prion disease. Results: Cynomolgus macaques (Macaca fasicularis) were infected intracerebrally with BSE-positive brain stem material from cattle and allowed to develop prion disease. Brain tissue from the basis pontis and vermis cerebelli of the six animals and the same regions from four healthy controls were subjected to ERV expression profiling using a retrovirus-specific microarray and quantitative real-time PCR. We could show that Class I gammaretroviruses HERV-E4-1, ERV-9, and MacERV-4 increase expression in BSE-infected macaques. In a second approach, we analysed ERV-K-(HML-2) RNA and protein expression in extracts from the same cynomolgus macaques. Here we found a significant downregulation of both, the macaque ERV-K-(HML-2) Gag protein and RNA in the frontal/parietal cortex of BSE-infected macaques. Conclusions: We provide evidence that dysregulation of ERVs in response to BSE-infection can be detected on both, the RNA and the protein level. To our knowledge, this is the first report on the differential expression of ERV-derived structural proteins in prion disorders. Our findings suggest that endogenous retroviruses may induce or exacerbate the pathological consequences of prion-associated neurodegeneration.
Project description:We constructed a genome wide target profile of hsa-miR-503, hsa-miR-103, and hsa-miR-494 by sequencing RNA isolated from Ago2 immunoprecipitations and total RNA samples following transfection of the respective miRNA in mature duplex form
Project description:The study describes miRNA expression in colonic epithelium of chronic SIV-infected rhesus macaques. We profiled and characterized miRNA/mRNA expression exclusively in colonic epithelium (CE) of 12 chronically SIV-infected and 8 control rhesus macaques (RMs). About 46 miRNAs were differentially expressed (DE) (20-up and 26-down) in CE during chronic SIV infection. Using TargetScan, we bioinformatically crossed the predicted targets of DE miRNAs to genome-wide transcriptomic data and identified several critical miRNA-mRNA pairings that suggested miRNA-mediated regulation of aberrant epithelial gene expression in CE. Immunofluorescence, luciferase reporter and miRNA overexpression studies confirmed the ability of miR-130a and miR-212 to bind the 3’ UTR and downregulate protein expression of occludin (OCLN) and peroxisome proliferator activator receptor gamma (PPAR), respectively, two proteins with pivotal roles in epithelial barrier function. MiR-130a and miR-212 overexpression in Caco-2 cells significantly reduced transepithelial electrical resistance (TEER). Interestingly, delta-9-tetrahydrocannabinol (9-THC) treatment restored TEER to levels observed with control miRNA mimic. Finally, ex-vivo 9-THC treatment of colon tissue from chronically SIV-infected RMs significantly increased PPAR gene expression. Our findings suggest that dysregulated miR-130a and miR-212 expression in CE during chronic HIV/SIV infection can facilitate epithelial barrier disruption by downregulating OCLN and PPAR protein expression. Most importantly, our results highlight the beneficial effects of cannabinoids on epithelial barrier function in not just HIV/SIV but potentially other chronic intestinal inflammatory diseases.
Project description:This study describes differential miRNA expression in intact colon tissue during acute SIV infection of rhesus macaques. Nine miRNAs were found to be significantly affected by infection, with 5 down-regulated and 4 up-regulated miRNAs. The expression of one upregulated miRNA was further characterized and found to be significantly elevated specifically in response to SIV replication and not immune activation/inflammation accompanying SIV infection.
Project description:Defects in stress responses are important contributors in many chronic conditions including cancer, cardiovascular disease, diabetes, and obesity-driven pathologies like non-alcoholic steatohepatitis (NASH). Specifically, endoplasmic reticulum (ER) stress is linked with these pathologies and control of ER stress can ameliorate tissue damage. MicroRNAs have a critical role in regulating diverse stress responses including ER stress. Here we show that miR-494-3p plays a functional role during ER stress. ER stress inducers (tunicamycin and thapsigargin) robustly increase the expression of miR-494 in vitro in an ATF6 dependent manner. Surprisingly, miR-494 pretreatment dampens the induction and magnitude of ER stress in response to tunicamycin in endothelial cells. Conversely, inhibition of miR-494 increases ER stress de novo and amplifies the effects of ER stress inducers. Using Mass Spectrometry (TMT-MS) we identified many proteins that are downregulated by both tunicamycin and miR-494 in cultured human umbilical vein endothelial cells (HUVECs). Among these, we found 6 transcripts which harbor a putative miR-494 binding site. Our data indicates that ER stress driven miR-494 may act in a feedback inhibitory loop to dampen downstream ER stress signaling. We propose that RNA-based approaches targeting miR-494 or its targets may be attractive candidates for inhibiting ER stress dependent pathologies in human disease.
2021-09-09 | PXD019992 | Pride
Project description:Genome-wide hsa-miR-503, hsa-miR-103, and hsa-miR-494 target profiles