ABSTRACT
Objective@#To investigate the impact of homocysteine inducible endoplasmic reticulum(ER) protein with ubiquitin like domain 1 protein (Herpud1) in the homocysteine (Hcy) -induced phenotypic switching of vascular smooth muscle cells (VSMCs).@*Methods@#VSMCs were derived from thoracic aortic artery of male Sprague Dawley rats and cultured VSMCs (4-7 passage) were treated with various concentrations of Hcy (0, 100, 500 and 1 000 μmol/L) and applied to immunofluorescence to observe the morphological changes of VSMCs via SM-actin staining. Western blot was used to detect the expression of VSMCs phenotypic markers, including Osteopontin, Calponin and smooth muscle myosin heavy chain (SM-MHC) and the expression of endoplasmic reticulum stress (ERS) related proteins, including C/EBP-homologous protein (CHOP), inositol-requiring kinase 1 (IRE-1) and glucose regulating protein 78 (GRP78) in the absence and presence of non-selective inhibitor of ERS, 4-phenylbutyric acid (4-PBA, 2 mg/ml). The Herpud1 mRNA and protein levels were determined in Hcy-stimulated VSMCs treated with 4-PBA or transfected with specific siRNA targeting Herpud1.@*Results@#Compared with the control group, SM-actin staining results showed that the shape of VSMCs treated with different concentrations of Hcy for 24 hours changed from long fusiform into round form, arrangement of myofilament became irregular and the most significant alteration was found in the 500 μmol/L Hcy group. After intervention of 24 hours, various concentration of Hcy increased protein expression of Osteopontin, and reduced Calponin and SM-MHC protein expressions in VSMCs (all P<0.05). In addition, the results showed that Hcy increased the expression of CHOP, IRE-1 and GRP78 in a dose-dependent manner, which could be reversed by 4-PBA treatment (all P<0.05). However, 4-PBA inhibited Hcy induced upregulation of Osteopontin and downregulation of Calponin and SM-MHC, suggesting that ERS was involved in Hcy-induced phenotypic switching of VSMCs. Herpud1 protein was mostly expressed in the cytoplasm and was also expressed in the nucli, both in the control, Hcy and Hcy+4-PBA groups. Moreover, Hcy increased mRNA and protein levels of Herpud1 (P<0.05), whereas treatment with 4-PBA could significantly reduce Hcy-induced upregulation of Herpud1 (P<0.05). Furthermore, knockdown of Herpud1 abrogated the effects of Hcy on VSMCs phenotype markers.@*Conclusion@#Herpud1 plays an important role in Hcy-induced phenotypic switching of VSMCs.
ABSTRACT
AIM: To study the possibility that yellow wine improves the pathological changes of atherosclerosis in vivo. METHODS: Six weeks old LDL receptor knockout mice (n=48) on a high-fat and L-methionine diet developed plasma hyperhomocysteinemia and atherosclerosis. The animals were randomly divided into yellow wine group, red wine group, ethanol group and control group (n=12 in each group) and were sacrificed after 14 weeks. The levels of plasma lipids and homocysteine in serum were examined. The morphological changes of aorta artery and the atherosclerosis of aorta sinus were observed under microscope. The expression and activation of matrix metalloproteinase-2 (MMP-2) were determined by the method of immunohistochemistry. RESULTS: No significant difference of plasma total cholesterol, triglyceride or high density lipoprotein cholesterol among groups was observed. Plasma homocysteine was significantly decreased in yellow wine group as compared to other three groups (P<0.01). Compared to ethanol and control groups, use of yellow wine and red wine significantly reduced the atherosclerosis lesion area (P<0.01). However, no significant discrepancy between the yellow wine group and red wine group was found. Compared to control group, the expression of MMP-2 in yellow wine group, red wine group and ethanol group decreased by 26.3%, 27.6% (P<0.01) and 5.7% (P>0.05), respectively. The activity of MMP-2 in yellow wine group, red wine group and ethanol group decreased by 31.7%, 32.5% (P<0.01) and 6.7% (P>0.05), respectively. CONCLUSION: Yellow wine and red wine inhibit the expression of MMP-2 and improve the pathologic changes of atherosclerosis, indicating that they have benefic effects on cardiovascular system.