miRNAs through β-ARR2/p-ERK1/2 pathway regulate the VSMC proliferation and migration

Background: miRNAs are involved in plaque formation of atherosclerosis and vessel restenosis. In this study, we investigated the effects of miR-599, miR-204, and miR-181b on VSMC proliferation, and migration through TGFβ receptor 2 (TGFβR2), β-arrestin 2 (β-ARR2), SMAD2/p-SMAD2, and ERK1/2/p-ERK1/2. Materials & methods: Genes and miRNAs were predicted by bioinformatics tools and were transfected by PEI-miRNAs (miR-599, miR-204, and miR-181b) complexes into VSMCs. The gene and protein expression levels were evaluated by real-time RT-PCR and western blotting techniques, respectively. The VSMC proliferation and migration were studied by MTT and scratch assay, respectively. Results: The miR-181b and miR-204 downregulated significantly β-ARR2 gene and protein expression levels and p-ERK1/2 values. Moreover, TGFβR2 gene and protein expression levels and p-SMAD2 values were not significantly affected by miR-181b and miR-204. The VSMC proliferation (p = 0.0019, p = 0.0054, respectively) and migration (p < 0.0001, p < 0.0001, respectively) were inhibited by the miR-181b and miR-204. The miR-599 inhibited VSMC proliferation (p = 0.044) and migration (p = 0.0055) but it did not affect significantly the β-ARR2 and TGFβR2 gene and protein expression levels. Conclusion: The results suggested that the inhibitory effects of miR-181b and miR-204 on VSMC proliferation and migration are mediated by the β-ARR2/p-ERK1/2 pathway. Since VSMC proliferation and migration are involved in plaque growth, therefore this pathway can be a therapeutic target for atherosclerosis. © 202

Combination of metformin and chlorogenic acid attenuates hepatic steatosis and inflammation in high-fat diet fed mice

Non-alcoholic fatty liver disease (NAFLD) has become an important health problem in the world. Natural products, with anti-inflammatory properties, are potential candidates for alleviating NAFLD. Metformin (MET) and chlorogenic acid (CGA) have been reported to be effective in the improvement of NAFLD. Here, we aimed to evaluate the efficacy of MET and CGA combination in ameliorating NAFLD in high-fat diet (HFD) fed mice. Fifty C57BL/6 male mice were divided into two groups, one fed a standard chow diet (n = 10) and the other was fed an HFD (n = 40) for 10 weeks. Animals in the HFD group were then randomly divided into a four groups (HFD, HFD + MET (0.25), HFD + CGA (0.02) and HFD + MET + CGA (0.25 + 0.02). MET and CGA combination decreases fasting blood glucose and improves glucose intolerance. Decreased hepatic triglyceride level was associated with lower expression levels of fatty acid synthase and sterol regulatory element-binding protein-1c in MET+CGA treated mice. MET and CGA combination treatment resulted in the polarization of macrophages to the M2 phenotype, reduction of the expression of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), and decreasing protein level of NF-kB p65. It was found that the lowering effect of combined MET and CGA on the expression of gluconeogenic genes was accompanied by increasing phosphorylation of glycogen synthase kinase 3β. Treatment of HFD mice with the combination of MET and CGA was found to be more effective at alleviating inflammation and lipid accumulation by increasing phosphorylation of AMP-activated protein kinase. In conclusion, these findings suggest that the MET + CGA combination might exert therapeutic effects against NAFLD. © 2020 International Union of Biochemistry and Molecular Biolog

miR-181b and miR-204 suppress the VSMC proliferation and migration by downregulation of HCK

Background: VSMC proliferation and migration pathways play important roles in plaque formation in the vessel stenosis and re-stenosis processes. The microRNAs affect the expression of many genes that regulate these cellular processes. The aim of this study was to investigate the effects of miR-181b, miR-204, and miR-599 on the gene and protein expression levels of hematopoietic cell kinase (HCK) in VSMCs. Methods: miR-181b, miR-204 were predicted for the suppression of HCK in the chemokine signaling pathway using bioinformatics tools. Then, the VSMCs were transfected by PEI-containing microRNAs. The HCK gene and protein expression levels were evaluated using RT-qPCR and Western blotting techniques, respectively. Moreover, the cellular proliferation and migration were evaluated by MTT and scratch assay methods. Results: The miR-181b and miR-204 decreased significantly the HCK gene and (total and phosphorylated) protein expression levels. Also, the miR-599 did not show any significant effects on the HCK gene and protein levels. The data also showed that miR-181b, miR-204, and miR-599 prevent significantly the proliferation and migration of VSMCs. Conclusion: The downregulation of HCK by miR-181b and miR-204 suppressed the VSMC proliferation and migration. © 202