|dc.description.abstract||The past recent years have seen a surge of evidence demonstrating the regulation of microRNAs (miRNAs) in a myriad of vascular biology events such as cardiogenesis. Nevertheless, the missing miRNA-link in controlling pluripotent human embryonic stem cell (hESC) fate in differentiation towards the endothelial lineage is currently undiscovered. Main objectives in this project are determining which miRNAs are involved in endothelial lineage differentiation from hESCs and the further delineation in their underlying mechanisms.
Firstly, undifferentiated hESCs were cultured in differentiating conditions to derive endothelial (ECs) and smooth muscle cells (SMCs). hESC-derived ECs express specific EC markers such as PECAM/CD31, eNOS, and vWF, while hESC-derived SMCs express specific SMC markers such as SMA and SMMHC II. Both hESC-derived cells also displayed functional characteristics upon functional analyses.
Next, five potential miRNAs involved in embryonic EC development were determined and selected from the miRNA array expression profile in differentiating hESCs. Using loss- and gain-of-function gene experiments, it was demonstrated that both miR-150 and miR-200c played an important role in EC differentiation from hESCs. However, miR-1915, 141 and 205 did not display such functions. In addition, epithelial-to-mesenchymal transition (EMT)-activator ZEB1/TCF8 was further identified as an important mRNA target for miR-150* and 200c. Importantly, it was also demonstrated that miR-150* and miR-200c were both involved in the vasculogenesis of in vivo chick embryos.
These findings may suggest that during hESCs differentiation, an increase of miR-200c expression contribute to the decline or repression of EMT process. Meanwhile, mir-150* also contributes to the differentiation of hESCs, resulting in the formation of more
differentiated, senescence and less proliferative cells or in this case, mature vascular ECs. These findings illustrate that miR-150* and 200c can regulate the development of ECs from hESCs, providing new targets for modulating vascular formation and creating novel clinical therapies in future cardiovascular disease applications.||en_US