MicroRNA-130a expression is decreased in Xinjiang Uygur patients with type 2 diabetes mellitus

Abstract

Aims: MicroRNAs play important roles in energy metabolism, insulin synthesis, insulin transport and the development of diabetes. This study aims to investigate the expression and effect of microRNA-130a in Uygur patients with type 2 diabetes mellitus (T2DM).

Materials and methods: Peripheral blood and omental adipose tissues were collected from individuals with normal glucose tolerance and patients with T2DM. The microRNA expression profile of peripheral blood was established by microarray analysis. The differentially expressed microRNAs and possible target genes were identified by bioinformatics analysis. MicroRNA-130a mimics and inhibitors were transfected into 3T3-L1 preadipocytes.

Results: Our results showed that microRNA-130a expression level was significantly decreased in peripheral blood and omental adipose tissues of T2DM patients (P < 0.01). Peroxisome proliferator-activated receptors γ (PPARγ) were predicted as target genes of microRNA-130a. This prediction was verified by the results that PPARγ mRNA expression in omental adipose tissues of T2DM patients were significantly increased (P < 0.01). The glucose consumption level after microRNA-130a transfection was significantly decreased (P < 0.05). And, microRNA-130a mimics inhibited PPARγ expression at both mRNA and protein level, further suggesting that PPARγ is a target gene of microRNA-130a. Additionally, adiponectin, lipoprotein lipase, CCAAT enhancer binding protein α, and the downstream genes of PPARγ, were significantly decreased after microRNA-130a mimics transfection.

Conclusions: In conclusion, microRNA-130a is decreased in Uygur patients with T2DM and it may play a role in T2DM through targeting PPARγ.

Keywords: Uygur; microRNAs; microarray; peroxisome proliferator-activated receptors γ; tumor necrosis factor α; type 2 diabetes.

Figure 1

Analysis of miRNA expression in peripheral blood of NGT and T2DM patients. Real-time PCR was performed to analyze the expression levels of miR-130a, 892a, 155, 133a, 421, 10b, 193b, 29a, 143, and 107. β-actin was used as an internal control. Relative expression levels of miRNAs were calculated based on those of β-actin. Compared with NGT, *P < 0.01.

Figure 2

Analysis of miRNA and PPARγ expression in omental adipose tissues of NGT and T2DM patients. Real-time PCR was performed to analyze the expression levels of miRNAs and PPARγ. β-actin was used as an internal control. Relative expression levels were calculated based on those of β-actin. A. Expression levels of miR-130a, 107, 29a, and 143. Compared with NGT, *P < 0.01. B. Expression levels of PPARγ mRNA. Compared with NGT, *P < 0.05.

Figure 3

Analysis of glucose consumption level after miR-130a mimics transfection. At 72 h after transfection with miR-130a mimics, miR-130a inhibitors and control siRNA, cell culture supernatant of 3T3-L1 preadipocytes was collected and the levels of glucose were measured. Compared with control, *P < 0.05.

Figure 4

Analysis of PPARγ protein level after miR-130a mimics transfection. At 72 h after transfection with miR-130a mimics, miR-130a inhibitors and control siRNA, preadipocytes were collected and total proteins were extracted. Western blotting was performed to detect the expression of PPARγ protein. GAPDH was used as an internal control. A. Representative Western blotting results. B. Quantitative Western blotting results. Compared with control, *P < 0.05.

Figure 5

Analysis of APM1, LPL, CEBPα, PPARγ, AP2 and GLUT4 expression at mRNA level after miR-130a mimics transfection. Real-time PCR was carried out at 72 h after miR130a mimics (75 nM) transfection. β-actin was used as an internal control. Relative expression levels were calculated based on those of β-actin. Compared with control, *P < 0.05.