[Homocysteine induces glomerular podocyte apoptosis via up-regulation of miR-488-3p expression in MPC-5 mice].

Objective To explore the role of microRNA-488-3p (miR-488-3p) in podocytes apoptosis induced by homocysteine (Hcy). Methods Flow cytometry was employed to analyze the ratio of podocytes apoptosis after treated with 0 µmol/L Hcy (control group) or 80 µmol/L Hcy (Hcy group) for 48 hours. The expression levels of B-cell lymphoma 2 (Bcl2), Bcl2-related X protein (BAX), and caspase-3 were measured by Western blot analysis in podocytes, after cells were treated with 80 µmol/L Hcy (Hcy group) for 48 hours, and the expression of miR-488-3p was detected by real-time PCR. The transfection and apoptosis ratio of podocytes were also detected after cells were transfected with miR-488-3p inhibitor. Results The apoptosis rate of podocytes increased in cells treated with Hcy, compared with control group. The expression levels of BAX and caspase-3 increased significantly in Hcy group, while Bcl2 expression was suppressed by Hcy. Furthermore, the expression of miR-488-3p increased in Hcy-induced podocyte. On the contrary, podocyte showed an decreased apoptosis rate, expression levels of BAX and caspase-3 decreased after cells were transfected with miR-488-3p inhibitor. However, Bcl2, which was not in this line, showed an increase when the cells transfected with miR-488-3p inhibitor. Conclusion Hcy promotes apoptosis of podocyte by up-regulating the expression of miR-488-3p.

Extracellular-superoxide dismutase DNA methylation promotes oxidative stress in homocysteine-induced atherosclerosis.

In the present study, we investigate the effect of homocysteine (Hcy) on extracellular-superoxide dismutase (EC-SOD) DNA methylation in the aorta of mice, and explore the underlying mechanism in macrophages, trying to identify the key targets of Hcy-induced EC-SOD methylation changes. ApoE -/- mice are fed different diets for 15 weeks, EC-SOD and DNA methyltransferase 1 (DNMT1) expression levels are detected by RT-PCR and western blot analysis. EC-SOD methylation levels are assessed by ntMS-PCR. After EC-SOD overexpression or knockdown in macrophages, following the transfection of macrophages with pEGFP-N1-DNMT1, the methylation levels of EC-SOD are detected. Our data show that the concentrations of Hcy and the area of atherogenic lesions are significantly increased in ApoE -/- mice fed with a high-methionine diet, and have a positive correlation with the levels of superoxide anions, which indicates that Hcy-activated superoxide anions enhance the development of atherogenic lesions. EC-SOD expression is suppressed by Hcy, and the content of superoxide anion is increased when EC-SOD is silenced by RNAi in macrophages, suggesting that EC-SOD plays a major part in oxidative stress induced by Hcy. Furthermore, the promoter activity of EC-SOD is increased following transfection with the -1/-1100 fragment, and EC-SOD methylation level is significantly suppressed by Hcy, and more significantly decreased upon DNMT1 overexpression. In conclusion, Hcy may alter the DNA methylation status and DNMT1 acts as the essential enzyme in the methyl transfer process to disturb the status of EC-SOD DNA methylation, leading to decreased expression of EC-SOD and increased oxidative stress and atherosclerosis.

[Overexpression of ephrin-A receptor 2 (EphA2) in invasive breast cancer tissues and its negative correlation with pyroptosis].

Objective To investigate how ephrin-A receptor 2 (EphA2) involves in pyroptosis in invasive breast cancer tissues. Methods The protein expression levels of EphA2, NLR family pyrin domain containing 3 (NLRP3), caspase-1, interleukin-1ß (IL-1ß), and intercellular adhesion molecule-1 (ICAM-1) in cancer tissues, paracancerous tissues, and normal breast tissues of breast cancer patients were detected by Western blot; the expression of EPHA2 in cancer tissues and paracancerous tissues of 45 patients with breast cancer was detected by immunofluorescence assay; and the correlation between protein expression of EphA2 and NLRP3, caspase-1, and IL-1ß in patients' cancer tissues was analyzed by Pearson correlation coefficient. Results The protein expression levels of NLRP3, caspase-1, IL-1ß, and ICAM-1 were significantly decreased and the protein expression of EphA2 was significantly increased in cancer tissues compared with those in normal breast tissues and paracancerous tissues. EphA2 level was negatively correlated with the levels of NLRP3, caspase-1 and IL-1ß. Conclusion EphA2 is overexpressed in breast cancer tissues and negatively correlated with pyroptosis.