ABSTRACT
Objective To examine the expression of potassium channel mRNA in myocardial tissue of mice with low selenium.Methods Forty C57BL/6 mice were randomly divided into four groups according to body weight(18-22 g),10 mice in each group,half male and half female.The low-selenium treatment groups were fed with low-selenium diet(selenium content was 0.004 mg/kg) for 4,12 and 24 weeks,respectively,and the control group was fed with normal diet(selenium content was 0.256 mg/kg).The mice were killed by cutting neck method,hearts were taken out and RNA was extracted by Trizol method.The expressions of potassium ion channel genes (KCNA4,KCND2,KCND3,KCNE1,KCNE2,KCNJ2,KCNJ12 and KCNQ1) at the mRNA level in heart were determined using real-time polymerase chain reaction.Results In low-selenium 4 weeks group,the mRNA expressions of KCNA4 gene(25.3 ± 0.09) and KCND2 gene(4.85 ± 0.05) were higher than that of the control group (1.00 ± 0.00,1.00 ± 0.00,all P ＜ 0.05); in low-selenium 24 weeks group,the mRNA expression of KCNJ12 gene (22.7 ± 0.10) was higher than that of the control group(1.00 ± 0.00,P ＜ 0.05); the mRNA expressions of KCND3,KCNE1,KCNE2,KCNJ2,KCNQ1 genes were compared with the corresponding control groups,the differences were not statistically significant(all P ＞ 0.05).Conclusions Low selenium can affect the mRNA expression of mouse cardiac potassium ion channel genes.
ABSTRACT
Objective To observe the influence of selenocysteine synthase(SEPSECS) on injury of human umbilical vein endothelial cell line EVC-304 induced by hydrogen peroxide (H2O2). Methods Transfection was conducted to transfect EVC-304 which was maintained in vitro. The cells were divided into four groups: control group, SEPSECS over-expression group, empty vector group and SEPSECS silenced expression group, then Real-time PCR and Western blotting were performed to detected SEPSECS mRNA and protein expression , respectively. Flow cytometry(FCM) was performed to detect cell cycle. Different concentrations of H2O2, which including 0, 200, 400, 600, 800, 1 000 μmol/L, were used to treat EVC-304 . Then malonaldehyde (MDA), superoxide dismutase(SOD) secreted by the cells which were treated with H2O2 for 6 h, were checked by MDA or SOD kit. Results The SEPSECS mRNA expressions of control, SEPSECS silenced expression, empty vector and SEPSECS over-expression groups were 1.03 ± 0.24, 0.43 ± 0.11, 0.98 ± 0.27 and 1.61 ± 0.13, respectively. The protein expressions of control, SEPSECS silenced expression, empty vector and SEPSECS over-expression groups were 1.00 ± 0.26, 0.51 ± 0.10, 1.12 ± 0.38 and 1.51 ± 0.20, respectively. There was a significant difference between control and SEPSECS silenced expression groups (all P 0.05). Meanwhile, MDA of SEPSECS silenced expression groups[(15.8 ± 0.5),(19.6 ± 1.5)μmol/L] were significantly higher than control groups[(12.4 ± 0.1),(17.1 ± 0.5)μmol/L, all P < 0.05], on the other hand, MDA of SEPSECS over-expression groups[(10.8 ± 0.4),(14.2 ± 1.1)μmol/L] were lower than empty vector groups [(12.7 ± 0.7),(16.2 ± 1.1)μmol/L, all P < 0.05], when the H2O2 concentration was 800 or 1 000μmol/L. The level of SOD was decreased along with the H2O2 concentration. SOD of SEPSECS silenced expression groups[(7.7 ± 0.4),(2.4 ± 0.3)μmol/L] were lower than control groups[(10.0 ± 1.0),(6.0 ± 0.6)μmol/L, all P < 0.05], on the contrary, SOD of SEPSECS over-expression groups[(11.3 ± 0.6),(12.7 ± 1.6)μmol/L] were higher than empty vector groups[(9.2 ± 0.6),(6.7 ± 0.2)μmol/L, all P < 0.05], when the H2O2 concentration was 800 or 1 000μmol/L. Conclusion Expression of SEPSECS has a significant protective role on damaged EVC-304 which was induced by H2O2.