Down-Regulation of miR-34a-5p Potentiates Protective Effect of Adipose-Derived Mesenchymal Stem Cells Against Ischemic Myocardial Infarction by Stimulating the Expression of C1q/Tumor Necrosis Factor-Related Protein-9.

Chi-Feng Weng,Jeen-Chen Chen,Ching-Feng Wu,Hui-Han Lin,Shao-Hsuan Kao

doi:10.3389/fphys.2019.01445

Abstract

Adipose-derived stem cells (ADSCs) have shown great promise for the treatment of myocardial infarction (MI), although their potential therapeutic mechanism remains poorly understood. Growing evidence has implicated microRNAs (miRNAs or miRs) in the biological processes whereby ADSCs could ameliorate cardiovascular disease. In this study, we explored the contribution of miR-34a-5p down-regulation to the protective actions of ADSCs against MI. We initially identified the interaction between miR-34a-5p and C1q/tumor necrosis factor-related protein-9 (CTRP9) through in silico analysis. We next tested the effects of miR-34a-5p and CTRP9 on the expression of extracellular signal-regulated kinase 1 (ERK1), matrix metalloproteinase-9 (MMP-9), nuclear factor (erythroid-derived 2)-like 2 (NRF2), and antioxidant proteins [manganese superoxide dismutase (MnSOD), and heme oxygenase-1 (HO-1)] through gain- and loss-of-function tests. In other experiments, we assessed the proliferation, migration, and apoptosis of ADSCs using the EdU assay, scratch test, Transwell assay, and flow cytometry. Finally, we studied whether miR-34a-5p/CTRP9 axis could modulate the protective effect of ADSCs against MI during stem cell transplantation in MI mouse models. miR-34a-5p could target and down-regulate CTRP9 in cardiomyocytes. Down-regulated miR-34a-5p increased the expression of ERK1, MMP-9, NRF2, MnSOD, and HO-1, whereas down-regulation of miR-34a-5p or up-regulation of CTRP9 in vitro promoted ADSC proliferation and migration and inhibited ADSC apoptosis. Moreover, miR-34a-5p down-regulation or CTRP9 up-regulation promoted the protective role of ADSCs against MI damage in vivo. Thus, inhibition of miR-34a-5p may facilitate ADSC’s protective function against MI damage by stimulating the expression of CTRP9.

Highlights

MATERIALS AND METHODSMyocardial infarction (MI) represents a major health threat, which is associated with severe morbidity and mortality across the world (Fiedler et al, 2011)
A specific binding region existing between 3′untranslated region (3′UTR) of C1q/tumor necrosis factor-related protein-9 (CTRP9) and miR-34a-5p revealed that CTRP9 was a target gene of miR-34a-5p (Figure 1A)
Dual-luciferase reporter gene assay (Figure 1B) showed that luciferase activity of 3′UTR in CTRP9 WT was inhibited by the miR-34a-5p mimic (p < 0.05), while no obvious change was observed in the luciferase activity of 3′UTR in CTRP9 MUT (p > 0.05), indicating that miR-34a-5p could target CTRP9

Summary

Introduction

Myocardial infarction (MI) represents a major health threat, which is associated with severe morbidity and mortality across the world (Fiedler et al, 2011). Adipose-derived stem cells (ADSCs) are important factors in tissue repair, presenting a potentially useful therapeutic effect in translational research on tissue regeneration (Huang et al, 2013). ADSCs show promising effects when delivered by intracoronary and transendocardial techniques after AMI (Rigol et al, 2010). One of the major barriers for cell therapy in the treatment of MI is that the transplanted cells often fail to differentiate into myocardial cells due to the ischemia, hypoxia, and oxidative stress in the target tissue following infarction (Wu et al, 2017). A need exists for new cellular approaches for the treatment of MI

Results

Discussion

Conclusion