The effects of intermittent hypobaric hypoxia on myocardial ischemia/reperfusion injury and ZFP580 expression / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To elucidate whether ZFP580 is involved in the cardioprotective effects of intermittent hypobaric hypoxia (IHH) against myocardial ischemia/reperfusion (I/R) injury.</p><p><b>METHODS</b>Thirty two male Wistar rats were randomly divided into 2 groups (n = 16): normoxia control group and IHH preconditioning group. Rats in IHH group were exposed in a hypobaric chamber (equivalent to an altitude of 5 000 m) for a 6 h period each day for 42 d. Plasma was collected and lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) were measured after 2 h of myocardial I/R injury. ZFP580 protein expression in myocardial tissue was assayed by Western blot. Other 8 rats in each group were used to evaluate I/R-induced cardiac infarction by TTC staining. Lentivirus-mediated gene transfection was performed in H9c2 cells 72 h prior to simulated ischemia/reperfusion (SI/R) exposure. The degree of cell apoptosis was determined by annexin V/7-AAD staining and flow cytometry analysis.</p><p><b>RESULTS</b>Compared with normoxia control group, adaptation to IHH attenuated infarct size and plasma leakage of LDH and CK-MB. In addition, ZFP580 expression in the myocardium was up-regulated by IHH. The results of gene transfection showed that ZFP580 overexpression significantly inhibited cells apoptosis induced by SI/R.</p><p><b>CONCLUSION</b>Our findings demonstrate that the cardioprotective effect of IHH against I/R injury is mediated via ZFP580, a novel transcription factor, with anti-apoptotic roles in myocardial cells.</p>

Cycle arrest of prostate carcinoma DU-145 cells induced by pseudolaric acid B / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of pseudolaric acid B (PLAB) on cell proliferation and cycle of human prostate carcinoma DU-145 cells. method: Its inhibitory effect on the cell growth was measured by MTT method. Characteristics of cell death were determined by Hoechest 33342 staining. The cell cycle was detected by flow cytometry. The expressions of cyclin B1, cyclin D1 and CDK1 were detected by Real time-PCR and Western blot, respectively.</p><p><b>RESULT</b>PLAB notably inhibited DU-145 cell growth in a dose- and time dependent manner (P < 0.05). Its IC50 values of PLAB for DU-145 cells for 24, 48 and 72 h were 4.53, 2.39 and 2.08 micromol x L(-1), respectively. Having been treated with 5 micromol x L(-1) PLAB for 24 h, the cells showed such apoptosis characteristics as nuclei chromatin condensation and apoptotic body. With the increase in PLAB concentration, the proportion of G2/M phase cells strikingly increased in a dose- and time dependent manner (P < 0.05), meanwhile cyclin B1 and CDK1 showed over-expressions (P < 0.05), and the cyclin D1 showed under-expression (P < 0.05).</p><p><b>CONCLUSION</b>PLAB can inhibit the growth of DU-145 cells and induce the cell cycle G2/M arrest, accompanied with the over-expression of cyclin B1 and CDK1, which may be related with its regulation cycle-associated protein degradation.</p>

The role of ouabain in cell death of vascular endothelial cells ECV304 and the changes of expression of Na+, K(+)-ATPase alpha1, beta1-subunit / 中国应用生理学杂志

<p><b>AIM</b>To study the effect of Na+, K(+)-ATPase inhibition by ouabain on growth and death of vascular endothelial cells ECV304 and involved mechanisms.</p><p><b>METHODS</b>Growth inhibition of ouabain on ECV304 cells was analyzed using MTT assay. The feature of cell death was studied by Hoechst 33342/PI staining, transmission electron microscopy and DNA agarose gel electrophoresis in ECV304 cells treated with ouabain. The mRNA expression of Na+, K(+)-ATPase alpha1, beta1-subunit was examined by reverse transcription PCR (RT-PCR).</p><p><b>RESULTS</b>Ouabain inhibited the growth of ECV304 cells in a dose and time-dependent manner. 10 micromol/L ouabain treated for 24 hours could stimulate the necrosis of ECV304 cells; When treated with 0.1 micromol/L ouabain for 24-48 hours, the cells showed obviously defluxion, the loss of cell-cell contacts, nuclear chromatin condensation, chromatin margination and DNA fragmentation. Na+, K(+)-ATPase alpha1-subunit mRNA expression was significantly up-regulated in ECV304 cells treated with ouabain while the beta1-subunit expression conversely showed a significant decrease.</p><p><b>CONCLUSION</b>Ouabain could up-regulate Na+, K(+)-ATPase alpha1-Subunit expression and reduce beta1-Subunit expression which mediated signal transduction and decreased cell-cell adhesions and induced ECV304 cells death.</p>