MicroRNA 16 enhances differentiation of human bone marrow mesenchymal stem cells in a cardiac niche toward myogenic phenotypes in vitro.
OBJECTIVE
Upregulation of microRNA 16 (miR-16) contributed to the differentiation of human bone marrow mesenchymal stem cells (hMSCs) toward myogenic phenotypes in a cardiac niche, the present study aimed to determine the role of miR-16 in this process.


METHODS
hMSCs and neonatal rat ventricular myocytes were co-cultured indirectly in two chambers to set up a cardiac microenvironment (niche). miRNA expression profile in cardiac-niche-induced hMSCs was detected by miRNA microarray. Cardiac marker expression and cell cycle analysis were determined in different treatment hMSCs. Quantitative real-time PCR and Western blot were used to identify the expression of mRNA, mature miRNA and protein of interest.


RESULTS
miRNA dysregulation was shown in hMSCs after cardiac niche induction. miR-16 was upregulated in cardiac-niche-induced hMSCs. Overexpression of miR-16 significantly increased G1-phase arrest of the cell cycle in hMSCs and enhanced the expression of cardiac marker genes, including GATA4, NK2-5, MEF2C and TNNI3. Differentiation-inducing factor 3 (DIF-3), a G0/G1 cell cycle arrest compound, was used to induce G1 phase arrest in cardiac-niche-induced hMSCs, and the expression of cardiac marker genes was up-regulated in DIF-3-treated hMSCs. The expression of CCND1, CCND2 and CDK6 was suppressed by miR-16 in hMSCs. CDK6, CCND1 or CCND2 knockdown resulted in G1 phase arrest in hMSCs and upregulation of cardiac marker gene expression in hMSCs in a cardiac niche.


CONCLUSIONS
miR-16 enhances G1 phase arrest in hMSCs, contributing to the differentiation of hMSCs toward myogenic phenotypes when in a cardiac niche. This mechanism provides a novel strategy for pre-modification of hMSCs before hMSC-based transplantation therapy for severe heart diseases.
Research Center of Guangdong General Hospital, Guangdong Provincial Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou 510080, China.
Ju-Li
JL
Liu
Li
L
Jiang
Qiu-Xiong
QX
Lin
Chun-Yu
CY
Deng
Li-Ping
LP
Mai
Jie-Ning
JN
Zhu
Xiao-Hong
XH
Li
Xi-Yong
XY
Yu
Shu-Guang
SG
Lin
Zhi-Xin
ZX
Shan
D000818:Animals; D001854:Bone Marrow Cells / Q000502:physiology*; D059447:Cell Cycle Checkpoints / Q000235:genetics; D002454:Cell Differentiation / Q000502:physiology*; D018920:Coculture Techniques; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D009132:Muscles / Q000166:cytology / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000502:physiology*; D010641:Phenotype; D051381:Rats; D015854:Up-Regulation / Q000235:genetics*; D055815:Young Adult
C505362:MIRN16 microRNA, human; D035683:MicroRNAs