BioProject

MicroRNAs (miRNAs) are non-coding RNAs that play a fundamental role in regulation of gene expression affecting differentiation and development. More...

MicroRNAs (miRNAs) are non-coding RNAs that play a fundamental role in regulation of gene expression affecting differentiation and development. In particular, miRNAs have been described to regulate genes important for pancreatic development and islet function. The aim of this work was to determine the miRNA expression signature in human pancreatic alpha and beta cells. miRNA stability to fixation allowed the study of microRNA in pure populations of human alpha and beta cells sorted by FACS after intracellular staining with glucagon and insulin, respectively. The determination of the specific group of miRNAs expressed in the human pancreatic alpha and beta cells may further the understanding of gene expression regulation of the islet differentiation process. Overall design: The alpha and beta cells come from 6 different preparations of human pancreatic islets from donors. In this study we define expression profiles of a total of 665 miRNAs for pancreatic alpha and beta cells. For this purpose, cells were fixed with paraformaldehyde, 7AAD was applied to exclude dead cells. Then, cells were sorted after intracellular staining with C peptide to detect beta cells and glucagon to detect alpha cells. After sorting, we confirmed enriched beta cells have a purity of on average over 98%. Enriched alpha cells have a purity of on average over 98%. To determine the miRNA expression profiles, we used human miRNA TLDAs version 2. For each sample card A and card B were run after cDNA synthesis and 12 cycles of preamplification according to the manufacturer protocol. Each TLDA card A contains 1 probe for the endogenous control RNU48 while each TLDA card B contains 4 replicates of the RNU48 probe. Analysis of these controls allows calculating the intra- and inter-assay variation. Quantitative values (RQ) were calculated measuring the ddCt between the Ct values of each miRNA and the Ct value of the small nucleolar RNU48 RNA comparing the target sample and the control sample. Less...