[Effects of rosuvastatin in homocysteine induced mouse vascular smooth muscle cell dedifferentiation and endoplasmic reticulum stress and its mechanisms].

OBJECTIVE: To investigate the effect of rosuvastatin on homocysteine (Hcy) induced mousevascular smooth muscle cells(VSMCs) dedifferentiation and endoplasmic reticulum stress(ERS). METHODS: VSMCs were co-cultured with Hcy and different concentration of rosuvastatin (0.1, 1.0 and 10 µmol/L). Cytoskeleton remodeling, VSMCs phenotype markers (smooth muscle actin-α, calponin and osteopontin) and ERS marker mRNAs (Herpud1, XBP1s and GRP78) were detected at predicted time. Tunicamycin was used to induce, respectively 4-phenylbutyrate(4-PBA) inhibition, ERS in VSMCs and cellular migration, proliferation and expression of phenotype proteins were analyzed. Mammalian target of rapamycin(mTOR)-P70S6 kinase (P70S6K) signaling agonist phosphatidic acid and inhibitor rapamycin were used in Rsv treated VSMCs. And then mTOR signaling and ERS associated mRNAs were detected. RESULTS: Compared with Hcy group, Hcy+ Rsv group (1.0 and 10 µmol/L) showed enhanced α-SMA and calponin expression (P<0.01), suppressed ERS mRNA levels (P<0.01) and promoted polarity of cytoskeleton. Compared with Hcy group, Hcy+Rsv group and Hcy+4-PBA group showed suppressed proliferation, migration and enhanced contractile protein expression (P<0.01); while tunicamycin could reverse the effect of Rsv on Hcy treated cells. Furthermore, alleviated mTOR-P70S6K phosphorylation and ERS (P<0.01)were observed in Hcy+Rsv group and Hcy+rapamycin group, compared with Hcy group; while phosphatidic acid inhibited the effect of Rsv on mTOR signaling activation and ERS mRNA levels (P<0.01). CONCLUSIONS: Rosuvastatin could inhibit Hcy induced VSMCs dedifferentiation via suppressing ERS, which might be regulated by mTOR-P70S6K signaling.

[Effects of yellow wine polyphenols on cardiomyocyte apoptosis in diabetic cardiomyopathy rats].

OBJECTIVE: To investigate the effects of yellow wine polyphenols on the apoptosis of cardiomyocytes in diabetic cardiomyopathy rats. METHODS: Thirty SD rats were randomly divided into control group (Control), diabetic cardiomyopathy group (DCM) and diabetic cardiomyopathy treated with yellow wine polyphenols group (DCM+YWP). A single intraperitoneal injection of 65 mg/kg streptozotocin (STZ) was utilized to establish a rat model of DCM. The rats in control group were treated with citrate buffer at the same dose of a single intraperitoneal injection. DCM+YWP group were treated with 18 mg/kg Yellow wine polyphenols by ig after modeling. After treated for 12 weeks, the general condition of rats were observed. The cardiac structure and function of the rats were observed by Doppler echocardiography. The ultrastructure of myocardium were observed using electron microscopy. The inflammation index of myocardial tissue was detected by enzyme-linked immunosorbent assay (ELISA). The oxidative stress in myocardial tissues was assessed by oxidative stress detection kits. The expressions of Bax, Bcl-2 and Caspase-3 (cleaved) in myocardial were detected by Western blot. RESULTS: Compared with DCM group, the blood glucose levels and body weight of rats in the DCM+YWP group were not changed significantly. Echocardiography showed that left ventricular end-diastolic diameter, left ventricular end-systolic diameter were decreased (P<0.05), while fractional shortening and E/A ratio and Ea/Aa ratio were elevated (P<0.05). The levels of tumor factor-α(TNF-α), interleukin 1ß(IL-1ß) and interleukin 6(IL-6) in myocardium were decreased (P<0.05). The levels of oxidative stress malondiadehyde(MDA) were decreased and Superoxide dismutase(SOD), glutathione peroxidase(GSH-Px) were increased in myocardial tissue (P<0.05). The expression levels of Bax and Caspase-3 (cleaved) protein in myocardium were decreased (P<0.05), and the expression of Bcl-2 protein was increased (P<0.05). CONCLUSIONS: Yellow wine polyphenols can improve the diabetic cardiomyopathy rat cardiac function, attenuates inflammation and oxidative stress in diabetic rats, inhibit the apoptosis of cardiomyocytes in diabetic cardiomyopathy.

[Exploring the active ingredient of Chinese yellow wine which could inhibit the Hcy induced proliferation and migration of vascular smooth muscle cells].

OBJECTIVE: To explore the active ingredients in the Chinese yellow wine could inhibit the proliferation and migration of rat vascular smooth muscle cells induced by homocysteine (Hcy). METHODS: The primary culture and identification of rat vascular smooth muscle cells (VSMCs) was conducted, and the VSMCs in passage 4-7 were used in the following experiments. The VSMCs were divided into 7 groups: control, Hcy (1 mmol/L), Hcy + oligosaccharide, Hcy + polypeptides, Hcy + polyphenols, Hcy + alcohol, Hcy + Chinese yellow wine and were given the corresponding treatment. The proliferation of VSMCs was determined by MTT. Transwell chambers and would healing were employed to test the migratory ability of VSMCs. Wester blot and gelatin zymography were used to investigate the expressions and activities of metal matrix proteinase 2/9 (MMP-2/9) and tissue inhibitor of metalloproteinase 2 (TIMP-2) in VSMCs of each group. RESULTS: Compared with control group, the proliferation, migration and the expression and activity of MMP-2/9 of VSMCs were significantly increased in the VSMCs of Hcy group (P < 0.01). Compared with Hcy group, the proliferation, migration and the expression and activity of MMP-2/9 of VSMCs were significantly decreases in the VSMCs of polypeptides group, polyphenols group and Chinese yellow wine group. However, the expression of TIMP-2 among each group had no significant difference. CONCLUSION: Polypeptides and polyphenols in the Chinese yellow wine could inhibit the proliferation and migration of VSMCs induced by Hcy.

Hyperhomocysteinemia independently causes and promotes atherosclerosis in LDL receptor-deficient mice.

BACKGROUND: Hyperhomocysteine is an independent risk factor of coronary heart disease (CHD). However, whether hyperhomocysteine affects the progression of atherosclerosis is unclear. In the present study, we examined the effect of hyperhomocysteine on the formation of atherosclerosis in low-density lipoprotein receptor-deficient (LDLr(-/-)) mice. METHODS: Forty-eight 7-week-old LDLr(-/-) mice were assigned to the following groups: mice fed a standard rodent diet (control group), mice fed a high-methionine diet (high-methionine group), mice fed a high-fat diet (high-fat group), and mice fed a diet high in both methionine and fat (high-methionine and high-fat group). At the age of 19, 23, and 27 weeks, four mice at each interval in every group were sacrificed. RESULTS: At the end of the study, mice did not show atherosclerotic lesions in the aortic sinus and aortic surface until 27 weeks old in the control group. However, atherosclerotic lesions developed in the other three groups at 19 weeks. The amount of atherosclerotic lesions on the aortic surface was lower in the high-methionine group than in the high-fat group (P < 0.001). Atherosclerotic lesions on the aortic surface in the high-methionine and high-fat group were the most severe. The mean area of atherosclerotic lesions in the aortic sinus compared with atherosclerotic lesions on the aortic surface was lower in the high-methionine group than in the high-fat group (P < 0.001). Atherosclerotic lesions in the aortic sinus in the high-methionine and high-fat group were the most severe. CONCLUSIONS: Homocysteinemia accelerates atherosclerotic lesions and induces early atherosclerosis independently in LDLr(-/-) mice. Reducing the level of homocysteinemia may be beneficial for prevention and treatment of CHD.

Effects of rosuvastatin on the production and activation of matrix metalloproteinase-2 and migration of cultured rat vascular smooth muscle cells induced by homocysteine.

OBJECTIVE: To test the influence of homocysteine on the production and activation of matrix metalloproteinase-2 (MMP-2) and tissue inhibitors of matrix metalloproteinase-2 (TIMP-2) and on cell migration of cultured rat vascular smooth muscle cells (VSMCs). Also, to explore whether rosuvastatin can alter the abnormal secretion and activation of MMP-2 and TIMP-2 and migration of VSMCs induced by homocysteine. METHODS: Rat VSMCs were incubated with different concentrations of homocysteine (50-5000 µmol/L). Western blotting and gelatin zymography were used to investigate the expressions and activities of MMP-2 and TIMP-2 in VSMCs in culture medium when induced with homocysteine for 24, 48, and 72 h. Transwell chambers were employed to test the migratory ability of VSMCs when incubated with homocysteine for 48 h. Different concentrations of rosuvastatin (10(-9)-10(-5) mol/L) were added when VSMCs were induced with 1000 µmol/L homocysteine. The expressions and activities of MMP-2 and TIMP-2 were examined after incubating for 24, 48, and 72 h, and the migration of VSMCs was also examined after incubating for 48 h. RESULTS: Homocysteine (50-1000 µmol/L) increased the production and activation of MMP-2 and expression of TIMP-2 in a dose-dependent manner. However, when incubated with 5000 µmol/L homocysteine, the expression of MMP-2 was up-regulated, but its activity was down-regulated. Increased homocysteine-induced production and activation of MMP-2 were reduced by rosuvastatin in a dose-dependent manner whereas secretion of TIMP-2 was not significantly altered by rosuvastatin. Homocysteine (50-5000 µmol/L) stimulated the migration of VSMCs in a dose-dependent manner, but this effect was eliminated by rosuvastatin. CONCLUSIONS: Homocysteine (50-1000 µmol/L) significantly increased the production and activation of MMP-2, the expression of TIMP-2, and the migration of VSMCs in a dose-dependent manner. Additional extracellular rosuvastatin can decrease the excessive expression and activation of MMP-2 and abnormal migration of VSMCs induced by homocysteine.