佛波酯处理人胃癌MGC80-3细胞过程中磷酯酶C-γ2的意义

目的 探讨佛波酯(TPA)处理人胃癌MGC80-3细胞过程中磷酯酶C-γ2(PLC-γ2)的意义.方法 通过DAPI染色,荧光显微镜观察分析TPA对胃癌MGC80-3细胞的影响;借助核浆分离手段获得胃癌细胞核浆蛋白,并通过免疫印迹(Western blotting)检测TPA对PLC-γ2蛋白表达水平影响;通过免疫荧光技术处理,激光扫描共焦显微镜观察胃癌细胞内PLC-γ2蛋白的定位和转运;用PLC-γ2的抑制剂(U73122)预处理细胞,免疫印迹和激光扫描共焦显微镜分别检测其对TPA作用胃癌细胞内PLC-γ2的影响;以及荧光显微镜下观察分析U73122是否影响TPA对胃癌细胞的作用.结果 TPA诱导胃癌MGC80-3细胞凋亡;同时TPA提高PLC-γ2蛋白表达水平,并诱导其发生核浆转运;其抑制剂(U73122)可以降低TPA对PLC-γ2蛋白表达水平的作用,但并不能影响TPA诱导胃癌细胞凋亡;而TPA诱导的PLC-γ2核浆转运却没有被PLC-γ2抑制剂(U73122)阻止.结论 尽管TPA提高了胃癌MGC80-3细胞中PLC-γ2表达水平,但PLC-γ2表达水平和TPA诱导的胃癌MGC80-3凋亡没有直接关系,而其核浆转运可能与TPA诱导的胃癌细胞凋亡相关.     

Pramipexole reduces inflammation in the experimental animal models of inflammation

Pramipexole is a dopamine (DA) agonist (D2 subfamily receptors) that widely use in the treatment of Parkinson’s diseases. Some epidemiological and genetic studies propose a role of inflammation in the pathophysiology of Parkinson’s disease. To our knowledge, there is no study regarding the anti-inflammatory activity of pramipexol. Therefore, the aim of the study was to investigate anti-inflammatory effect of pramipexol. Anti-inflammatory effects of pramipexole were studied in three well-characterized animal models of inflammation, including carrageenan- or formalin-induced paw inflammation in rats, and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear edema in mice. The animals received pramipexol (0.25, 0.5 and 1?mg/kg, I.P.) 30?min before subplantar injection of carrageenan or?formalin. Pramipexol (0.5 and 1?mg/kg) was also injected 30?min before topical application of TPA on the ear mice. Serum malondialdehyde (MDA) levels were evaluated in the carrageenan test. Finally, pathological examination of the inflamed tissues was carried out.

Pramipexole significantly inhibited paw inflammation 1, 2, 3 and 4?h after carrageenan challenge compared with the control group (p?p?TPA-induced ear edema was markedly decreased by pramipexol (p?These data clearly indicate that pramipexol possesses significant anti-inflammatory activity. It seems that its antioxidants do not play an important role in these effects.     

Baicalein inhibition of oxidative-stress-induced apoptosis via modulation of ERKs activation and induction of HO-1 gene expression in rat glioma cells C6

In the present study, we examined the protective mechanism of baicalein (BE) and its glycoside, baicalin (BI), on hydrogen-peroxide (H(2)O(2))-induced cell death in rat glioma C6 cells. Results of the MTT assay, LDH release assay, and morphological observation showed that H(2)O(2) addition reduced the viability of C6 cells, and this was prevented by the addition of BE but not BI. Incubation of C6 cells with BE significantly decreased the intracellular peroxide level induced by H(2)O(2) according to flow cytometric analysis using DCHF-DA as a fluorescent substrate. Suppression of H(2)O(2)-induced apoptotic events including DNA ladders, hypodiploid cells, and activation of caspases 3, 8, and, 9 by BE but not BI was identified in C6 cells. The cytotoxicity and phosphorylation of ERK proteins induced by H(2)O(2) were blocked by the ERK inhibitor PD98059. Catalase addition prevented H(2)O(2)-induced ROS production, ERKs protein phosphorylation, and cell death, and BE dose-dependently inhibited H(2)O(2)-induced ERK protein phosphorylation in C6 cells. These data suggest that ROS-scavenging activity is involved in BE prevention of H(2)O(2)-induced cell death via blocking ERKs activation. Additionally, BE but not BI induced heat shock protein 32 (HSP32; HO-1) protein expression in both time- and dose-dependent manners, but not heme oxygenase 2 (HO-2), heat shock protein 70 (HSP70), or heat shock protein 90 (HSP90) protein expression. In the absence of H(2)O(2), BE induces ERKs protein phosphorylation, and HO-1 protein expression induced by BE was blocked by the addition of cycloheximide, actinomycin D, and the ERK inhibitor PD98059. The addition of the HO inhibitor ZnPP inhibited the protective effect of BE against H(2)O(2)-induced cytotoxicity in C6 cells according to the MTT assay and apoptotic morphology under microscopic observation, accompanied by blocking the ROS-scavenging activity of BE in C6 cells. However, BE treatment was unable to protect C6 cells from C2-ceramide-induced cell death. These data indicate that BE possesses abilities to inhibit ROS-mediated cytotoxic effects through modulation of ERKs activation and induction of HO-1 protein expression. The role of HO-1 in ROS-scavenging activity of BE is proposed.