Protective effect of cyclophilin A against Alzheimer's amyloid beta-peptide (25-35)-induced oxidative stress in PC12 cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>beta-amyloid peptide (Abeta) is considered responsible for the pathogenesis of Alzheimer's disease (AD). Possible mechanisms underlying Abeta-induced neuronal cytotoxicity include excessive production of reactive oxidative species (ROS) and apoptosis. Cyclophilin A (CypA), exhibits antioxidant properties and protects neurons against oxidative stress induced injury. This study was conducted to demonstrate whether CyPA added to cultured PC12 cells could alleviate Abeta-induced oxidative stress and protect them from apoptosis.</p><p><b>METHODS</b>PC12 cells were pre-incubated for 30 minutes with recombinant human cyclophilin A (rhCyPA) in 0.1 nmol/L, 1.0 nmol/L, 10 nmol/L and 100 nmol/L and then incubated with 10 micromol/L Abeta(25-35). In every group, cell viability, apoptotic morphology, apoptotic rate, intracellular ROS accumulation, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of PC12 cells and mitochondrial transmembrane potential were detected. Subsequently, the expression of the active form of caspase-3 was determined by Western blotting.</p><p><b>RESULTS</b>It was shown that cultures treated with 1.0 nmol/L, 10 nmol/L or 100 nmol/L rhCyPA + Abeta(25-35) had significantly higher cell viability and a lower rate of apoptosis compared with the cultures exposed only to Abeta(25-35). In addition, rhCyPA attenuated Abeta(25-35)-induced overproduction of intracellular ROS and Abeta(25-35)-induced a decrease in activity of the key antioxidant enzymes SOD and GSH-Px. Furthermore, rhCyPA also attenuated Abeta(25-35)-induced mitochondrial dysfunction and the activation of caspase-3.</p><p><b>CONCLUSION</b>CyPA may act as an ROS scavenger, and prevent Abeta(25-35)-induced neurotoxicity through attenuating oxidative stress induced by Abeta(25-35).</p>

Study on the influencing factors to cerebral stroke in a region with high prevalence rate of hypertension / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the influencing factors on cerebral stroke in Zhangwu county, Liaoning province, a region with high hypertension prevalence rate.</p><p><b>METHODS</b>By cluster sampling method, 5208 adults ( > 18y. ) from 11 villages of 6 towns were registered. General information, common risk factors of cerebral stroke about these persons was recorded. Blood pressure together with several biochemistry indicators was determined. Data were analyzed by SPSS 10.0 software.</p><p><b>RESULTS</b>Standardized prevalence of cerebral stroke in this region was 3.10%, and the difference between males and females was significant. Prevalence rate was increasing with age. Multiple-factor analysis revealed that the incidence rate of cerebral stroke was related to high blood pressure, high diastolic pressure, pulse pressure, age, high-density lipoprotein cholesterol (HDL-C) and low-DL-C (LDL-C) level with OR values of 95% CI as 2.958 (1.783-4.907), 2.803 (1.934-4.062), 1.154 (1.056-1.261), 1.080 (1.063-1.097), 0.390 (0.235-0.647) and 1.422 (1.008-2.006) respectively.</p><p><b>CONCLUSION</b>High blood pressure, in particular high diastolic pressure, pulse pressure and LDL-C level were main risk factors of cerebral stroke in Zhangwu countryside. However, HDL-C level was a protective factor. No new risk factors were discovered.</p>