Defined MicroRNAs Induces Aspects of Maturation in Mouse and Human Embryonic-Stem-Cell Derived Cardiomyocytes

摘要

Advances in our ability to differentiate pluripotent stem cells into somatic cells of many lineages provide us with a platform for drug screening disease modeling and regenerative medicine Due to the high prevalence of cardiovascular disease cardiac cells are of particular interest Several outstanding groups have developed reproducible and efficient systems to differentiate pluripotent cells into cardiac cells However these pluripotent stem cell-derived cardiomyocytes often display the structural and functional attributes of fetal cardiomyocytes rather than adult cardiomyocytes This significantly limits the use of these cells for applications such as drug screening or regenerative medicine Thus a method for increasing the maturity of pluripotent stem cell-derived cardiomyocytes is highly desirable Studies of anatomy and developmental biology suggest that the function of heart is considerably dependent on endothelial cells We have shown that endothelial cells play a role in enhancing the maturation of murine ES-derived cardiomyocytes We have identified a cluster of miRNAs (miR-125b-5p miR-199a-5p miR-221 and miR-222) that are upregulated in cardiomyocytes upon their coculture with endothelial cells Exogenous addition of this combination of miRNAs was able to significantly increase the molecular structural and functional maturation of ES-derived CMs Bioinformatics revealed ErbB4 as the target of these four miRNAs and a luciferase reporter assay confirmed that these four miRNAs together targeted ErbB4 This finding was further confirmed by siRNA-induced downregulation of ErbB4 resulting in the enhanced maturation of ES-CMs To apply these findings to human cardiomyocyte maturation we tested the same miR combination in human ES-derived cardiomyocytes The enforced expression of this miR-combo was able to increase maturation of ES-derived cardiomyocytes into a more adult-like state evidenced by an increased binucleation ratio lower ANF expression improved respiratory capacity more negative resting membrane potential and polarized Connexin-43 In conclusion we present a novel approach for improving the maturity of cardiomyocytes differentiated from pluripotent stem cells This is a significant step towards realizing the full potential of iPS and ES-derived cardiomyocytes as platforms for drug screening and disease modeling

獎項日期	2016 1月 21
原文	English
監督員	Po-Min Chiang (Supervisor)