MicroRNA-9 inhibits high glucose-induced proliferation, differentiation and collagen accumulation of cardiac fibroblasts by down-regulation of TGFBR2.

Jiaxin Li,Guoqian Wei,Yingnan Dai,Zhendong Su

doi:10.1042/bsr20160346

Jiaxin Li, Guoqian Wei + Show 2 more

Open Access

https://doi.org/10.1042/bsr20160346

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Abstract

To investigate the effects of miR-9 on high glucose (HG)-induced cardiac fibrosis in human cardiac fibroblasts (HCFs), and to establish the mechanism underlying these effects. HCFs were transfected with miR-9 inhibitor or mimic, and then treated with normal or HG. Cell viability and proliferation were detected by using the Cell Counting Kit-8 (CCK-8) assay and Brdu-ELISA assay. Cell differentiation and collagen accumulation of HCFs were detected by qRT-PCR and Western blot assays respectively. The mRNA and protein expressions of transforming growth factor-β receptor type II (TGFBR2) were determined by qRT-PCR and Western blotting. Up-regulation of miR-9 dramatically improved HG-induced increases in cell proliferation, differentiation and collagen accumulation of HCFs. Moreover, bioinformatics analysis predicted that the TGFBR2 was a potential target gene of miR-9. Luciferase reporter assay demonstrated that miR-9 could directly target TGFBR2. Inhibition of TGFBR2 had the similar effect as miR-9 overexpression. Down-regulation of TGFBR2 in HCFs transfected with miR-9 inhibitor partially reversed the protective effect of miR-9 overexpression on HG-induced cardiac fibrosis in HCFs. Up-regulation of miR-9 ameliorates HG-induced proliferation, differentiation and collagen accumulation of HCFs by down-regulation of TGFBR2. These results provide further evidence for protective effect of miR-9 overexpression on HG-induced cardiac fibrosis.

Highlights

Long-term diabetes can lead to the development of cardiovascular complications such as cardiac fibrosis [1,2]
Effect of miR-9 on high glucose (HG)-induced proliferation of human cardiac fibroblasts (HCFs) To investigate the effect of miR-9 on HG-induced cell proliferation of HCFs, HCFs were transfected with miR-9 mimic at 0, 25, 50 or 100 nM for h before stimulation with 5.5 or mM glucose for 24 h, after which cell viability and proliferation were detected
We found that messenger RNA (mRNA) level of TGFBR2 was remarkably decreased after upregulation of miR-9 (Figure 4A), but was increased after down-regulation of miR-9 compared with HG-treated HCFs (Figure 4A)

Summary

Introduction

Long-term diabetes can lead to the development of cardiovascular complications such as cardiac fibrosis [1,2]. Up-regulation of miR-9 had the protective effect on HG-induced proliferation, differentiation and collagen accumulation of human cardiac fibroblasts (HCFs). Up-regulation of miR9 inhibited the increase in HG-induced α-SMA expression at mRNA and protein levels (Figure 2A).

Results

Conclusion