MicroRNA profiling by array of human pancreatic islets and pancreatic islet derived extracellular vesicles
ABSTRACT: Human pancreatic islets were isolated from pancreas of deceased donors by Ricordi's procedure and cultured in CMRL 1066 medium additioned with human albumin. EVs were isolated from conditioned medium derived from islet culture after isolation. Once isolated, RNA of islets and islet-derived EVs was extracted and analyzed for microRNA expression within 48 hours after isolation.
Project description:Identification of transcriptional profile of several genes involved in diabetes in islet-derived extracellular vesicles (Evs). Recently, EVs are identified as a new mechanism in cell-to-cell communication by transfer of protein and genic information (mRNA, microRNA). Their role is under investigation in immunology, stem cell and cancer, but not in islets and diabetes. The aim of this experiment is to identify mRNA transcripts (in particular, mRNA transcripts involved in diabetes pathophysiology) present in islet Evs.
Project description:Evaluation of microRNA expression profile of microvesicles (MVs) derived from endothelial progenitor cells (EPCs) cultured in different oxygen concentrations (normoxic/hypoxic conditions)
Project description:Tubular endothelial cells were cultured in hypoxic conditions (1% O2) and treated or not with microvesicles derived from endothelial progenitor cells.<br>mRNA profiling of hypoxic cells, treated or not with MVs, was analyzed after nromalization with mRNA profiling of normoxic cells.<br><br>This experiment was updated on 27th Jan 2011 to correct descriptions.
Project description:Endothelial cells derived from freshly purified human islets were incubated with microvesicles collected by ultracentrifugation of supernatants of endothelial progenitor cells (EPCs) isolated from peripheral blood of healthy volunteers.
Project description:HUVECs were cultured in hypoxic conditions for 24 hours and treated or not with 1uM caffeic acid. Then cells were evaluated for expression of different genes involved in angiogenesis
Project description:Purpose: To identify tissue microRNAs predictive of sunitinib activity in patients with metastatic renal-cell carcinoma (MRCC) and to validate them in a cellular model. Selected microRNAs were studied in serum from MRCC patients and healthy individuals. Methods: We screened 673 microRNAs using TaqMan Low-density Arrays (TLDAs) in tumors from MRCC patients with extreme phenotypes of marked efficacy and resistance to sunitinib, selected from an identification cohort (n=41). Differentially expressed microRNAs were selected using bioinformatics-based target prediction analysis and quantified by qRT-PCR in tumors from patients presenting similar phenoytpes selected from an independent cohort (n=117). Results were validated in a cellular model of sunitinib resistance and studied in serum from healthy individuals and MRCC patients. Results: TLDAs identified 64 microRNAs differentially expressed in the identification cohort. Seven candidates were quantified by qRT-PCR in the independent series. MiR-942 was the most accurate predictor of sunitinib efficacy (p=0.0074). High expression of miR-942, miR-133a, miR484, and miR-628-5p was significantly associated with decreased time-to-progression and overall survival. These microRNAs were overexpressed in the sunitinib resistant cell line Caki-2 in comparison with the sensitive parental cell line. Serum levels of miR-942, miR-133a, miR-484, miR-146a-5p, miR-374a and miR-486-5p were significantly reduced in MRCC patients compared to healthy controls. Conclusions: Our strategy identified differentially expressed microRNAs in MRCC patients presenting marked sensitivity and resistance to sunitinib. Mir-942 was the best predictor of efficacy. Results were confirmed in a cellular model of sunitinib resistance. We also identified exosome derived serum microRNAs differentially expressed in MRCC patients and healthy individuals. Taqman Low Density Array for 6 FFPE tissues obtained from extreme phenotype MRCC patients, (n=3 marked resistance to sunitinib treatment patients and n=3 marked sensitivity to sunitinib treatment patients), was performanced to screen 667 microRNAs.