Role and molecular mechanism of RGS6 in regulation of cardiomyocyte hypertrophy / 中国药理学通报

Aim To explore the regulatory effect and mechanism of Regulators of G-protein Signaling 6 (RGS6) in Ang H-induced hypertrophy. Methods RGS6 expression was up-and down-regulated respectively by AdRGS6 and AdshRGSó lentivirus. Each group was treated with Ang II /PBS. Cell size and changes of hypertrophic markers(ANP and BNP) were evaluated. Then ROS levels and the total protein and phosphorylated protein of E R K 1 / 2, p38, JNK1/2 in each group were detected. When the altered signaling was clarified, a reversal experiment of hypertrophic cardiomyocytes was conducted to further verify the signaling pathway. The RGS6 up-regulated cardiomyocytes of hypertrophy treated with ROS inhibitor (DPI) were experimental group. Results (Î) After stimulated with Ang II for 48 h, the size of AdRGS6-infected cell increased compared with AdGFP infection group. In addition, the mRNA levels of ANP and BNP also i n - creased. After stimulated with Ang II , the ROS levels and p - J N K l / 2 proteins of AdRGS6-infected cells all increased compared with AdGFP infection group. (2) After stimulated with Ang II for 48 h, the size of A d - shRGS6-infected cell decreased compared with AdshRNA infection group and the mRNA levels of ANP and BNP also decreased. The ROS levels and p - J N K l / 2 proteins of AdshRGS6-infected cell all decreased compared with AdshRNA infection group. (3) In the reversal experiments, compared with AdRGS6 + Ang 1 1 / DMSO group, the size of AdRGS6 + Ang H / D P I cardiomyocytes significantly decreased, and the downstream signaling of p - J N K l / 2 was improved. Conclusions RGS6 may be a key factor to cardiac hypertrophy. RGS6 aggravates Ang II -induced cardiomyocyte hypertrophy via activating R 0 S - K N K 1 / 2 signaling pathway.

Enterovirus 71 activates the JNK1/2 signaling pathway in human rhabdosarcoma cells / 临床检验杂志

Objective To investigate the role of c-Jun N-terminal kinase (JNK1/2) signaling pathway in enterovims 71 (EV71) infection.Methods The effects of different concentrations of SP600125 on the activity of human rhabdosarcoma (RD) cells were detected by trypanbalu staining.The levels of VP1 mRNA and protein in EV71-infected RD cells were detected by real time Q-PCR and western blot,respectively.The levels of total and phosphorylated JNK1/2,c-Fos and c-Jun protein were determined by western blot.Last,the effects of.JNK1/2 inhibitor SP600125 on EV71 replication and JNK1/2 signaling pathway were analyzed.Results The results of trypanbalu staining showed that 5 and 10 μmol/L of SP600125 didn't influence on the activity of RD cells (P ＞ 0.05),while 20 μmol/L of SP600125 decreased the survival of RD cells significantly (P ＜ 0.05).Compared with the control,the expression levels of VP1 mRNA and protein in EV71-infected RD cells decreased obviously at 8 hours post-infection (P ＜0.01).In addition,after RD cells were infected EV71,the levels of phosphorylated JNK1/2,c-Fos and c-Jun increased significantly (P ＜ 0.05).However,the pretreatment of SP600125 decreased the phosphorylation levels of JNK1/2,c-Fos and c-Jun protein obviously (P ＜ 0.05).Conclusion EV71 infection may effectively activate the JNK1/2 signaling pathway in RD cells,which may be related to EV71 replication.

Effects of losartan on expression of matrix metalloproteinase-2,JNK1/2 and proliferation in cardiac fibroblast / 中国临床药理学与治疗学

AIM: To elucidate the effects of losartan on the expression ofmatrix metalloproteinases-2, JNK1/2 and proliferation in cardiac fibroblast. METHODS: Neonatal rat cardiac fibroblasts were cultured. The cells proliferation was determined by MTT. To determine effects of AngⅡ on JNK1/2 activity, cells were incubated (for 0, 2, 5, 10, 30, 60, 120 min) in serum-freemedia with AngⅡ, and the other group fibroblasts were exposed to serum-free media with or without AngⅡ and losartan (AngⅡ 100 nmol/L, AngⅡ 100 nmol/L+losartan 100 nmol/L, losartan100 nmol/L, losartan for 45 min before). Cells protein was collected with MBST buffer. The relative abundance of MMP-2, JNK1/2 and p-JNK1/2 in cells was determined by immunoblotting. The secretion of MMP-2 in media of cell culture was determined by ELISA. RESULTS: AngⅡ increased the proliferation of CFB in a dose-dependent manner, whereas losartan decreased the proliferation of CFB stimulated by AngⅡ in a dose-dependant manner, too (P＜0.05). The relative abundance of JNK1/2 was highest in AngⅡ of the 2-min-stimulated group. AngⅡincreased expression of JNK1/2 and MMP-2 protein (P＜0.05), on the contrary, losartan inhibited JNK1/2 and MMP-2 protein expression.CONCLUSION: AngⅡ induce the increase of proliferation of CFB, expression of JNK1/2 and MMP-2 in CFB, and losartan inhibits these effects of AngⅡ.