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The differences in endothelial function between Tibetan and Han nationality population have not been fully investigated. The aim of this work is to investigate the differences in endothelial function and plasma endothelin 1 (ET-1) concentration between Tibetan and Han male population.Totally 272 Tibetan male subjects aged 42.9 ± 9.4 years were enrolled in this study to stand for Tibetan population. All of them were native residents in Lhasa City. And 580 Qinghai-Tibet Railway constructors with Han nationality aged 41.8 ± 11.1 years were enrolled in this study to stand for Han nationality population. All of them were male subjects and lived in Lhasa City for at least 1 year. All subjects lived in the same high-altitude area (the altitude of Lhasa is 3658 m). Height, weight, waist circumference, hip circumference, systolic blood pressure, diastolic blood pressure were evaluated. Body mass index (BMI) was calculated. Brachial artery flow-mediated dilation (FMD) was measured in the fasting state using high-resolution B-mode ultrasound. Computer-assisted analysis software was used to calculate brachial artery diameters. Venous blood was sampled for the measurement of total cholesterol (CH), triglyceride (TG), high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL) and HbA1c. Plasma ET-1 was quantitated using a commercially available ELISA kits.Totally 272 Tibetan subjects and 580 Han nationality subjects were enrolled in this study. BMI and waist-hip ratio in Tibetan subjects were much higher than those in Han subjects (p0.01). LDL cholesterol level and plasma ET-1 concentration in Tibetan subjects were significantly higher than Han subjects (p0.01). The baseline brachial artery diameter in Tibetan group was much higher than that of Han group (p0.01). The absolute and percent changes in brachial artery diameter were lower in Tibetan population compared with Han population (p0.01). The linear regression analysis showed that LDL cholesterol, and plasma ET-1 were correlated with FMD (p0.01).Endothelial function and plasma ET-1 concentration were different between Tibetan and Han male populations.

In this study, we investigated the regulation of resveratrol (RV) on miR-34a alteration due to ARI and further studied the involvement of miR-34a/Sirt1 signaling pathway in ROS generation and cell survival after ARI.In-vitro anoxia and reoxygenation injury (ARI) model based on rat heart-derived H9c2 cells was established. The expression of miR-34a and Sirt1 in H9c2 cells with or without RV pretreatment was measured. Flow cytometric analysis of intracellular reactive oxygen species (ROS) generation, CCK-8 assay of cell viability and Western blot analysis of active caspase-3 expression were performed to study the role of miR-34a/Sirt1 signaling pathway in RV modulated ARI injury protection.Pretreatment with RV substantially restored Sirt1 expression in cardiomyocytes in a dose-dependent manner in the in-vitro ARI model. MiR-34a level was significantly increased due to ARI. But pretreatment with RV significantly suppressed its upregulation. MiR-34a overexpression significantly reduced the effect of RV on restoring Sirt1 expression in ARI. Both miR-34a overexpression and Sirt1 knockdown significantly reduced the effect of RV on reducing ROS generation and also abrogated the effect of RV on enhancing cell viability and reducing cell apoptosis.The present study demonstrated that RV has a suppressive effect on miR-34a upregulation in ARI and the miR-34a/Sirt1 axis is an important signaling pathway modulating the protective effect of RV on cardiomyocytes in ARI. Nonetheless, future in vivo studies are required to validate this mechanism.

Polycystic ovary syndrome (PCOS) is a disorder characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovaries. In Tibet population, little is known about the correlation between PCOS and endothelial function and insulin resistance. In this study, we investigated the efficacy of simvastatin on ameliorating endothelial dysfunction and insulin resistance in Tibet patients with PCOS.A group of 21 PCOS women was compared with 21 age-paired controls for blood pressure, body mass index (BMI), lipids, glucose and insulin levels. Plasma ET-1 was quantitated using a commercially available ELISA kits. The invasive vascular endothelial function was evaluated through the measurement of brachial artery flow-mediated dilation (FMD) in the fasting state using high-resolution B-mode ultrasound and ankle-brachial index (ABI) by using a blood pressure cuff and a Doppler instrument.PCOS women had higher BMI (p0.05), blood pressure (p0.05), cholesterol (p0.05), triglyceride (p0.05), LDL cholesterol (p0.05) and lower HDL cholesterol (p0.05). Fasting insulin (p0.001) and 2-hour plasma glucose (p0.001) of PCOS were also found to be higher than that of controls. HOMA-IR of PCOS was calculated to be much higher than that of the control group (p0.001). ET-1 levels were significantly higher in the PCOS women compared with the control group (p0.001). FMD and ABI were impaired in the PCOS group when compared with the controls (p0.001). After simvastatin intervention for 6 months, FMD, ABI, HOMA-IR, lipid profile, BMI were ameliorated in PCOS women. Also, FMD, ABI, HOMA-IR, lipid profile were nearly normalized in PCOS women after statin treatment compared with the control women. Tibet PCOS patients present a clustering of atherosclerosis risk factors (obesity, adverse lipid profile, hypertension and hyperglycemia) and more prevalent in insulin resistance and endothelial dysfunction than non-PCOS women.The endothelial function and insulin resistance of PCOS patients were amelioratedThe endothelial function and insulin resistance of PCOS patients were ameliorated after statin administration.