Yiqi Huazhuo decoction increases insulin secretion in type 2 diabetic rats by regulating the pancreatic GPR40-IP3R-1 signaling pathway.

Objective: Yiqi Huazhuo Decoction (YD) reduces blood glucose, glycated hemoglobin, body weight, and insulin resistance in patients with type 2 diabetes mellitus (T2DM), but its exact mechanisms are unknown. This study investigated the therapeutic effects and mechanisms of YD on impaired insulin secretion in T2DM rats. Methods: T2DM rats were randomized to the model, YD-lo (15 mg/kg/d YD, 10 weeks), YD-hi (30 mg/kg/d YD, 10 weeks), positive drug (TAK-875), and healthy control groups. The rats underwent an oral glucose tolerance test (OGTT), glucose-stimulated insulin secretion (GSIS) test, and serum lipid measurements. High-fat and high-glucose-injured RIN-m5f cells were treated with YD (30 or 150 mg/mL) for 48 h. GPR40 and IP3R-1 expression levels were determined by immunofluorescence, qRT-PCR, and western blot. Results: Compared with the model group, the OGTT area under the curve (AUC) in the YD-hi group was decreased by 26.7%, the insulin release test (IRT) AUC in the YD-hi group was increased by 45.9%, and the GSIS AUC was increased by 33.9% (p < 0.05). Compared with the model cells, the insulin secretion after glucose stimulation in the YD-hi group was increased by 24.5%, similar to the TAK-875 group (23.1%) (p > 0.05). GPR40 and IP3R-1 mRNA in the model cells were decreased by 49.5% and 51.2% compared with the control cells (p < 0.05). In the YD-hi group, GPR40 and IP3R-1 mRNA levels were increased by 58.1% and 39.3% (p < 0.05), similar to the TAK-875 group. The changes in protein expression were similar to mRNA. Conclusion: YD promotes insulin secretion from pancreatic islet ß-cell in T2DM rats by regulating the GPR40-IP3R-1 pathway, thereby reducing blood glucose.

Yunpi Heluo decoction reduces ectopic deposition of lipids by regulating the SIRT1-FoxO1 autophagy pathway in diabetic rats.

CONTEXT: Yunpi Heluo (YPHL) decoction is a Chinese herbal formula with particular advantages for treating type 2 diabetes. Yet, its exact mechanism of action is not fully understood. OBJECTIVE: To examine the therapeutic effect of YPHL on ectopic lipid deposition (EDL) in Zucker diabetic fatty (ZDF) rats and the underlying mechanism. MATERIALS AND METHODS: The ZDF Rats were randomized into five groups, including model, YPHL (200 mg/kg/d for 10 weeks), SIRT1-overexpression (injected with HBAAV2/9-r-SIRT1-3'-flag-GFP), NC (injected with HBAAV2/9-CMV-GFP as blank control) and control group. Pancreatic ß-cells obtained from high-lipid-high-glucose fed rats were treated with YPHL (10 mg/mL) for 48 h. Lipid deposition and autophagosomes were analyzed by transmission electron microscopy. Intracellular H2O2 and ROS concentrations were measured by flow cytometry. SIRT1, FOXO1, LC3 and P62 mRNA and protein levels were analyzed using qRT-PCR and Western blots. RESULTS: Compared with the model group, blood glucose levels in YPHL and si-SIRT1 groups were reduced by 19.3% and 27.9%, respectively. In high-lipid-high-glucose cells treated with YPHL, lipid droplets were reduced and decrease in apoptosis rate (38.6%), H2O2 (31.2%) and ROS (44.5%) levels were observed. After YPHL intervention or SIRT1 overexpression, LC3 and p62 expression increased. Protein expression of SIRT1 and LC3 in model, si-SIRT1, si-NC and si-SIRT1 + YPHL groups was lower than those in control group, while FoxO1 expression was increased. All of these protein level alterations were reversed in the si-NC + YPHL group. DISCUSSION AND CONCLUSIONS: YPHL reduced EDL by regulating the SIRT1-FoxO1 autophagy pathway in diabetic rats, which could lead to future perspectives for the treatment of diabetes.

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.

Prevalence and factors associated with nonalcoholic fatty pancreas disease and its severity in China.

Pancreatic lipidosis (nonalcoholic fatty pancreas disease, NAFPD) causes insulin resistance and dysfunction of pancreatic ß-cells, with the risk of type 2 diabetes mellitus (T2DM). However, the prevalence and pathogenic factors associated with NAFPD are not clear. The aim of the study was to explore the prevalence of NAFPD in a Chinese adult population, and investigate factors associated with NAFPD aggravation.This was a cross-sectional study; 4419 subjects were enrolled for NAFPD screening and were divided into NAFPD (n = 488) and without NAFPD (n = 3930) groups. The sex, age, related concomitant diseases, general physical parameters, and serum glucose and lipid metabolism were compared between the 2 groups.The overall NAFPD prevalence was 11.05%, but increased with age. In those <55 years NAFPD prevalence was lower in females than males (P < .05), but prevalence was similar >55 years. Nonalcoholic fatty liver disease (NAFLD), T2DM, homeostasis model assessment-insulin resistance index, total cholesterol, triglyceride, lipoprotein, adiponectin, and glucagon-like peptide 1 (GLP-1) were the independent risk factors for NAFPD (P < .05). Analaysis of mild NAFPD (MN) and severe NAFPD (SN) subgroups, according to the extent of fat deposition, suggested that NAFLD, triglyceride, lipoprotein, and adiponectin were independent risk factors for NAFPD aggravation (P < .05).The NAFPD prevalence was about 11% in Chinese adults. Its development and progression was related to NAFLD, T2DM, insulin resistance, dyslipidemia, and GLP-1 levels. Severe NAFPD was associated with NAFLD and dyslipidemia.

Mechanism of Astragalus polysaccharides in attenuating insulin resistance in Rats with type 2 diabetes mellitus via the regulation of liver microRNA­203a­3p.

Insulin resistance (IR) is a common feature of type 2 diabetes mellitus (T2DM). Astragalus polysaccharides (APS) is a natural medicine that is used to treat T2DM. However, the mechanism by which APS regulates micro (mi)RNA in the treatment of IR has not been investigated. The purpose of the present study was to investigate differential miRNA expression between normal, T2DM model and APS treatment rats, as well as changes in miRNA and its downstream gene expression levels after APS treatment in T2DM Goto Kakizaki (GK) rats. Results suggested that miRNA (miR)­203a­3p expression level was significantly decreased in the liver of T2DM GK rats. Furthermore, it was identified that glucose­regulated protein (GRP)78 was the target gene of miR­203a­3p. GRP78 mRNA and protein expression levels of GRP78, CAAT­enhancer­binding protein homologous protein (CHOP), phosphorylated­c­Jun N­terminal kinase (pJNK)1, and caspase­12 were significantly increased in the liver of T2DM GK rats. Furthermore, miR­203a­3p was upregulated following APS treatment, and the protein expression levels of GRP78, CHOP, pJNK1 and caspase­12 were significantly decreased. In addition, miR­203a­3p overexpression in IR cells decreased the protein expression levels of these factors and anti­miR­203a­3p produced the opposite result. These findings provided evidence that miR­203a­3p may have a functional role in endoplasmic reticulum stress (ERS) signaling in the liver of T2DM GK rats. In addition, APS attenuated IR in T2DM, likely through upregulating or maintaining the miR­203a­3p expression levels, decreasing GRP78 mRNA and protein expression levels and regulating the protein expression of the ERS signaling pathway.