Altered pattern of circulating miRNAs in HIV lipodystrophy perturbs key adipose differentiation and inflammation pathways
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE183822 | GEO | 2021/09/22
REPOSITORIES: GEO
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Project description:Adipocytes are the primary sites for fatty acid storage, but the synthesis rate of fatty acids is very low. The physiological significance of this phenomenon remains unclear. Here, we show that surplus fatty acid synthesis in adipocytes induces necroptosis and lipodystrophy. Transcriptional activation of FASN elevates fatty acid synthesis, but decreases NADPH level and increases ROS production, which ultimately leads to adipocyte necroptosis. We identify MED20, a subunit of the Mediator complex, as a negative regulator of FASN transcription. Adipocyte-specific male Med20 knockout mice progressively develop lipodystrophy, which is reversed by scavenging ROS. Further, in a murine model of HIV-associated lipodystrophy and a human patient with acquired lipodystrophy, ROS neutralization significantly improves metabolic disorders, indicating a causal role of ROS in disease onset. Our study well explains the low fatty acid synthesis rate in adipocytes, and sheds light on the management of acquired lipodystrophy.
2023-12-11 | GSE249808 | GEO
Project description:Background and objective: Combination antiretroviral therapy (cART) is associated with lipodystrophy i.e. loss of subcutaneous adipose tissue in abdomen, limbs and face and its accumulation intra-abdominally. No fat is lost dorsocervically and it can even accumulates in this region (“buffalo hump”). It is unknown how preserved dorsocervical fat differs from abdominal subcutaneous fat in HIV-1-infected cART-treated patients with (cART+LD+) and without (cART+LD-) lipodystrophy. Results: Albeit dorsocervical adipose tissue in cART+LD+ seems spared from lipoatrophy, its mitochondrial DNA (mtDNA, copies/cell) content was significantly lower (by 62%) than that of the corresponding tissue in cART+LD-. Expression of CD68 mRNA, a marker of macrophages, and numerous inflammatory genes in microarray were significantly lower in dorsocervical vs. abdominal subcutaneous adipose tissue. Genes with the greatest difference in expression between the two depots were those involved in regulation of transcription and regionalization (homeobox genes), irrespective of lipodystrophy status. There was negligible mRNA expression of uncoupling protein 1, a gene characteristic of brown adipose tissue, in either depot. Conclusions: As mtDNA is depleted even in the non-atrophic dorsocervical adipose tissue, it is unlikely that the cause of lipoatrophy is loss of mtDNA. Dorsocervical adipose tissue is less inflamed than lipoatrophic adipose tissue. It does not resemble brown adipose tissue. The greatest difference in gene expression between dorsocervical and abdominal s.c. adipose tissue is in expression of homeobox genes. We used histology, microarray, polymerase chain reaction and magnetic resonance imaging to compare dorsocervical and abdominal subcutaneous adipose tissue in cART+LD+ (n=21) and cART+LD- (n=11). The study consists of 17 patients on antiretroviral treatment who have developed lipodystrophy and 11 patients that are on similar treatment but have not developped lipodystrophy. All patients are HIV+ and have 2 adipose tissue samples taken from them (dorsocervical+abdominal).
2011-09-14 | E-GEOD-28073 | biostudies-arrayexpress
Project description:In this setup we have used RNA-seq, ChIP-seq, and ATAC-seq to identify how natural mutations in PPARg, which leads to lipodystrophy, cause changes in transcription, chromatin landscape, transcription factor binding and enhancer activity.
2022-10-27 | GSE199426 | GEO
Project description:Purpose: Our single-cell RNAseq data show that LTBP2 is a marker of a cancer associated fibroblast subpopulation in colorectal cancer liver metastases. Moreover, MTT assays of cultured fibroblasts treated with anti-LTBP2 antibodies suggest that LTBP2 is essential for their survival. The goal of this study is to understand the role of LTBP2 in fibroblasts. Methods: Normal olon fibroblasts (CCD18Co) were transfected 48h with siRNA containing an anti-LTBP2 or a non target sequence. Cell monolayer total RNA of 3 biological replicates was then extracted and submitted to Illumina RNAseq using NovaSeq6000. Results: Transcriptomics revealed massive changes in gene expression when LTBP2 is knocked down: 496 genes were differentially expressed between the colon fibroblasts treated with siRNA anti-LTBP2 and NT. Those genes are implicated in diverse biological processes such as extracellular matrix organization, angiogenesis or cell adhesion. Conclusions: Our study explored LTBP2 functions in normal fibroblasts. RNAseq data support its important role. After 48h, LTBP2 silencing induces changes in gene expression of numerous genes involved in fibroblast functions.
2022-11-22 | GSE191323 | GEO
Project description:Genome wide DNA methylation profiling of Congenital Lipodystrophy type 2 patients, mutation carriers , and healthy control samples .The Infinium MethylationEPIC Kit was used to measure genome-wide DNA methylation across > 868,000 CpG sites.
2023-08-08 | GSE214297 | GEO
Project description:Several members from microRNA 17-92 cluster, i.e. miR-19a, miR-19b and miR-20a, were found up-regulated in human epidermal keratinocytes at wound-edges compared to the intact skin; however their biological role in keratinocytes during wound repair has not been studied. To study the genes regulated by miR-19a, miR-19b and miR-20a, we transfected miRNA specific mimics, i.e. pre-miR-19a, pre-miR-19b or pre-miR-20a into human primary epidermal keratinocytes to overexpress them. We performed a global transcriptome analysis of keratinocytes upon overexpression of miR-19a or miR-19b or miR-20a using Affymetrix arrays.
2017-02-15 | GSE93110 | GEO
Project description:MicroRNAs are endogenously expressed small non-coding RNAs that regulate gene expression on the posttranscriptional level. The miR-17-92 cluster (encoding miR-17, -18a, -19a/b, -20a and miR-92a) is highly expressed in tumor cells and is up-regulated by ischemia. Whereas miR-92a was recently identified as negative regulator of angiogenesis, the specific functions of the other members of the cluster are less clear. Here we demonstrate that overexpression of miR-17, -18a, -19a and -20a significantly inhibited 3D spheroid sprouting in vitro, whereas inhibition of miR-17, -18a and -20a augmented endothelial cell (EC) sprout formation. Inhibition of miR-17 and miR-20a in vivo using antagomirs significantly increased the number of perfused vessels in matrigel plugs, whereas antagomirs, that specifically target miR-18a and miR-19a were less effective. However, systemic inhibition of miR-17/20 did not affect tumor angiogenesis. Further mechanistic studies showed that miR-17/20 targets several pro-angiogenic genes. Specifically, Janus kinase 1 (Jak1) was shown to be a direct target of miR-17. In summary, we show that miR-17/20 exhibit a cell intrinsic anti-angiogenic activity in ECs. Inhibition of miR-17/20 specifically augmented neovascularization of matrigel plugs, but did not affect tumor angiogenesis indicating a context-dependent regulation of angiogenesis by miR-17/20 in vivo. 6 samples of 3 independent experiments (n=3): per experiment Pre-miR-Co (10 nM, Ambion) and Pre-miR-17 (10 nM, Ambion) transfected HUVEC 24h after transfection
2010-03-23 | E-GEOD-20745 | biostudies-arrayexpress
Project description:The peroxisome proliferator-activated receptor γ (PPARγ) is the master regulator of adipocyte differentiation, and mutations that interfere with PPARγ function cause lipodystrophy. Structural studies indicate that PPARγ domains engage in several intra- and inter-moleuclar interactions; however, how these interactions modulate the ability of PPARγ to activate target genes in a cellular context is currently poorly understood. Here we analysed the transcriptional potential of R212Q and E379K two previously uncharacterised lipodystrophy-associated PPARγ mutants that are located in distinct PPARγ domains but are both predicted to affect intermolecular interactions. Using a combination of biochemical and genome-wide approaches we show that these mutations impair binding to an overlapping subset of enhancers that are less accessible and specifically require PPARγ for chromatin remodeling. Based on these findings we propose a model in which recruitment of PPARγ to chromatin is determined by several intermolecular interfaces. Furthermore, our data exemplify that relatively subtle molecular defects in transcription factors are sufficient to significantly affect enhancer binding and thereby transcriptional output.
2022-09-08 | PXD036589 | Pride
Project description:MicroRNAs are endogenously expressed small non-coding RNAs that regulate gene expression on the posttranscriptional level. The miR-17-92 cluster (encoding miR-17, -18a, -19a/b, -20a and miR-92a) is highly expressed in tumor cells and is up-regulated by ischemia. Whereas miR-92a was recently identified as negative regulator of angiogenesis, the specific functions of the other members of the cluster are less clear. Here we demonstrate that overexpression of miR-17, -18a, -19a and -20a significantly inhibited 3D spheroid sprouting in vitro, whereas inhibition of miR-17, -18a and -20a augmented endothelial cell (EC) sprout formation. Inhibition of miR-17 and miR-20a in vivo using antagomirs significantly increased the number of perfused vessels in matrigel plugs, whereas antagomirs, that specifically target miR-18a and miR-19a were less effective. However, systemic inhibition of miR-17/20 did not affect tumor angiogenesis. Further mechanistic studies showed that miR-17/20 targets several pro-angiogenic genes. Specifically, Janus kinase 1 (Jak1) was shown to be a direct target of miR-17. In summary, we show that miR-17/20 exhibit a cell intrinsic anti-angiogenic activity in ECs. Inhibition of miR-17/20 specifically augmented neovascularization of matrigel plugs, but did not affect tumor angiogenesis indicating a context-dependent regulation of angiogenesis by miR-17/20 in vivo.
2010-03-13 | GSE20745 | GEO
Project description:Objective: To characterize downstream effectors of p300 acetyltransferase in the myocardium. Background: Acetyltransferase p300 is a central driver of the hypertrophic response to increased workload, but its biological targets and downstream effectors are incompletely known. Methods and Results: Mice expressing a myocyte-restricted transgene encoding acetyltransferase p300, previously shown to develop spontaneous hypertrophy, were observed to undergo robust compensatory blood vessel growth together with increased angiogenic gene expression. Chromatin immunoprecipitation demonstrated binding of p300 to the enhancers of the angiogenic regulators Angpt1 and Egln3. Interestingly, p300 overexpression in vivo was also associated with relative upregulation of several members of the anti-angiogenic miR-17~92 cluster in vivo. Confirming this finding, both miR-17-3p and miR-20a were upregulated in neonatal rat ventricular myocytes following adenoviral transduction of p300. Relative expression of most members of the 17~92 cluster was similar in all 4 cardiac chambers and in other organs, however, significant downregulation of miR-17-3p and miR-20a occurred between 1 and 8 months of age in both wt and tg mice. The decline in expression of these microRNAs was associated with increased expression of VEGFA, a validated miR-20a target. In addition, miR-20a was demonstrated to directly repress p300 expression through a consensus binding site in the p300 3’UTR. In vivo transduction of p300 resulted in repression both of p300 and of p300-induced angiogenic transcripts. Conclusion: p300 drives an angiogenic transcription program during hypertrophy that is fine-tuned in part through direct repression of p300 by miR-20a. 4 littermates, 3 transgene-expressing and 1 wild-type were analyzed. Samples were spotted in duplicate.
2013-09-30 | E-GEOD-50843 | biostudies-arrayexpress