Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes
Project description:Mesenchymal stem/stromal cells (MSCs) were harvested from subcutaneous adipose tissue of patients with obesity or healthy controls and expanded for 3-4 passages, and 5hmC profiles were examined through hydroxymethylated DNA immunoprecipitation sequencing (hMeDIP-seq). We hypothesized that obesity and cardiovascular risk factors induce functionally-relevant, locus-specific changes in overall exonic coverage of 5hmC in human adipose-derived MSCs.
Project description:Visceral adiposity is a risk factor for severe COVID-19, and a link between adipose tissue infection and disease progression has been proposed. Here we demonstrate that SARS-CoV-2 infects human adipose tissue and undergoes productive infection in human primary adipose-derived stromal-vascular cells differentiated into adipocytes. However, the permissiveness to infection and the cellular response depends on the anatomical origin of the cells and the viral lineage. Cells of visceral adipose tissue origin express more ACE2 and are more permissive to SARS-CoV-2 infection than their subcutaneous counterpart. SARS-CoV-2 infection leads to inhibition of lipolysis in cells of subcutaneous origin, while in visceral fat cells, it results in higher expression of pro-inflammatory cytokines. Viral load and cellular response are attenuated when visceral adipose tissue cells are infected with the SARS-CoV-2 gamma variant. A similar degree of cell death occurs 4-days after SARS-CoV-2 infection, regardless of the cell origin or viral lineage. Hence, SARS-CoV-2 infects human adipose tissue cells, replicating and altering cell function and viability in a fat depot- and viral lineage-dependent fashion.
Project description:Diabetes and obesity are widespread diseases with signifciant socioeconomic implications. We used three different types of human adipose tissue (epigastric, visceral, and subcutaneous) in order to determine differences in global gene expression between these adipose depots in severely obese patients. In this dataset, we include the expression data obtained from three types of adipose tissue; epigastric, subcutaneous, and visceral all obtained through open gastric bypass surgery. 18 total samples were analyzed. Tissues were paired together to run on one genechip, with three pairs of epigastric, three pairs of subcutaneous, and three pairs of visceral were ran on nine genechips. Comparisons of gene expression in the form of fold changes between pairs of adipose types (i.e., subcutaneous/epigastric, visceral/epigastric, and subcutaneous/visceral) were completed by Spotfire Analysis.