Yunpi Heluo decoction attenuates insulin resistance by regulating liver miR-29a-3p in Zucker diabetic fatty rats.

BACKGROUND AND OBJECTIVE: Yunpiheluo (YPHL) decoction is a Chinese herbal formula with unique advantages for the treatment of type 2 diabetes mellitus (T2DM). The aim of the present study was to investigate changes in miRNA expression and downstream gene expression in Zucker diabetic fatty (ZDF) rats treated with YPHL to determine whether YPHL could be used as an adjuvant treatment of T2DM. METHODS: Serum and liver total cholesterol (TC) and triglycerides (TG) levels, insulin resistance index (IR) and differentially expressed miRNAs were detected in a T2DM ZDF rat model. miRNA target prediction was based on bioinformatic algorithms and dual luciferase reporter assay. Protein expression of genes in the insulin receptor signaling pathway was detected by Western blot. The IR cell model was established and the effects of lyophilized YPHL powder on the protein expressions were observed by transfecting specific miRNA mimics and inhibitors. RESULTS: The miR-29a-3p expression level was significantly increased in the liver of ZDF rats. Insulin receptor substrate 1 (IRS1) was the target gene of miR-29a-3p. IRS1 mRNA and protein expressions of IRS1, IRS1 (phospho S307), protein kinase B (Akt), Akt (phosphor ser473) and pyruvate dehydrogenase lipoamide kinase isozyme 1 (PDK1) were decreased significantly. miR-29a-3p over-expression decrease IRS1 and the others protein expressions in the HepG2 IR cell model while anti-miR-29a-3p showed the opposite result. The miR-29a-3p level was decreased, and the expressions of IRS1 mRNA and the above proteins were all increased after YPHL treatment. CONCLUSION: miR-29a-3p played a functional role in insulin receptor signaling in the liver of ZDF rats. YPHL decoction attenuated IR in T2DM probably by down-regulating or maintaining the miR-29a-3p level, increasing the expression of IRS1 mRNA and its phosphorylated proteins, and regulating the expression of insulin receptor signaling-related proteins. YPHL may prove to be an alternative treatment for T2DM.

Lipidomics as a tool of predicting progression from non-alcoholic fatty pancreas disease to type 2 diabetes mellitus.

The lipid metabolism relationship between non-alcoholic fatty pancreas disease (NAFPD) and type 2 diabetes mellitus (T2DM) is poorly defined. We aim to identify novel T2DM-related lipid biomarkers in addition to previous studies and provide the evidence for elucidating the relationship between NAFPD and T2DM in a lipid perspective. In this study, multi-dimensional mass spectrometry-based shotgun lipidomics (MDMS-SL) was used to investigate the potential discriminating lipid profile of the fasting plasma of 105 Chinese individuals (39 NAFPD patients, 38 T2DM patients and 30 healthy controls). Then multivariate statistical analysis combined with pathway analysis was performed to identify the lipid biomarker and explore the potential relationship of these two important diseases. The results described a marked reduction of plasmalogen and a significant 4-hydroxynonenal increase in the two diagnostic group, which indicated increased oxidative stress and peroxisomal dysfunction in patients. 60 discriminating metabolites were identified by multivariate statistical analysis of the lipidomics data. In addition, ingenuity pathway analysis (IPA) and a metabolic network constructed by prediction of IPA indicated that lipid metabolism, molecular transport, carbohydrate metabolism and small molecule biochemistry were correlated with disease progression. Our results revealed that the profile of plasma lipid alteration characteristic of NAFPD was similar to that of T2DM, especially during the period prior to the onset of T2DM.