AIM: To evaluate the effects of NS-398, a cyclooxygenase-2 (COX-2) inhibitor, on the proliferation and apoptosis of HepG2 cells. METHODS: The effects of NS-398 on the proliferation of HepG2 cells were evaluated by MTT...AIM: To evaluate the effects of NS-398, a cyclooxygenase-2 (COX-2) inhibitor, on the proliferation and apoptosis of HepG2 cells. METHODS: The effects of NS-398 on the proliferation of HepG2 cells were evaluated by MTT. DNA fragmentation gel analysis was used to analyze the apoptotic cells. DNA ploidy and apoptotic cell percentage were calculated by flow cytornetry. The expression of COX-2 and Bcl-2 mRNA was identified by competitive RT-PCR. Furthermore, expression level of Bcl-2 was detected using Western blot in HepG2 after treated with NS-398. RESULTS: NS-398 inhibited cell proliferation and induced apoptosis of HepG2 cells in a concentration-dependent manner. DNA ploidy analysis showed that S phase cells were significantly decreased with increase of NS-398 concentration. The quiescent GO/G1 phase was accumulated with decrease of Bcl-2 mRNA. Whereas NS-398 had no effect on the expression of COX-2 mRNA, and no correlations were found between COX-2 mRNA and HepG2 cell proliferation and apoptosis induced by NS-398 (r=0.056 and r=0.119, respectively). Bcl-2 protein level was inhibited after treated with NS-398. CONCLUSION: NS-398 significantly inhibits the proliferation and induces apoptosis of HepG2 cells. Mechanisms involved may be accumulation of quiescent GO/G1 phase and decrease of Bcl-2 expression.展开更多
文摘目的探讨黄酮类化合物芹菜素对大鼠实验性心肌缺血/再灌注(ischemia/reperfusion,I/R)时心肌细胞凋亡与Bcl-2、Bax、Caspase-3蛋白表达的影响,并分析心肌组织病理学损伤程度。方法采用结扎左冠状动脉前降支,心肌缺血45 min,再灌注2 h制作缺血/再灌注模型。将大鼠随机分为8组,即正常组(normal group,Normal)、假手术组(sham oper-ation group,Sham)、生理盐水缺血/再灌注组(saline ischemi-a-reperfusion group,NS)、溶剂对照组(solvent control group,Sol)、美托洛尔对照组(metoprolol control group,Meto)、芹菜素低、中、高剂量(1、2、4 mg.kg-1)用药组(apigenin low,medium and high dose treatment group,Api1,Api2,Api4)。再灌注2 h后迅速取出心脏,TUNEL法原位标记凋亡的心肌细胞;免疫组化法测Bcl-2、Bax和Caspase-3蛋白表达;做病理组织切片检查心肌损伤情况。结果芹菜素各剂量组心肌细胞凋亡率明显低于NS组(P<0.05),Api1,Api2,Api4能剂量依赖性地降低大鼠缺血/再灌注心肌细胞凋亡率;芹菜素各剂量组剂量依赖性地提高大鼠心肌缺血/再灌注的Bcl-2蛋白表达量(P<0.05)、降低大鼠心肌缺血/再灌注的Bax、Caspase-3蛋白表达量(P<0.05);芹菜素各剂量组与NS组比较,心肌组织损伤的病理学变化明显减轻(P<0.05)。结论芹菜素对缺血/再灌注心肌的保护效应可能与其抑制缺血/再灌注心肌细胞凋亡有关;芹菜素抗心肌凋亡作用的机制可能与其上调Bcl-2蛋白表达和下调Bax、Caspase-3蛋白表达有关;芹菜素能明显减轻心肌组织损伤。
文摘AIM: To evaluate the effects of NS-398, a cyclooxygenase-2 (COX-2) inhibitor, on the proliferation and apoptosis of HepG2 cells. METHODS: The effects of NS-398 on the proliferation of HepG2 cells were evaluated by MTT. DNA fragmentation gel analysis was used to analyze the apoptotic cells. DNA ploidy and apoptotic cell percentage were calculated by flow cytornetry. The expression of COX-2 and Bcl-2 mRNA was identified by competitive RT-PCR. Furthermore, expression level of Bcl-2 was detected using Western blot in HepG2 after treated with NS-398. RESULTS: NS-398 inhibited cell proliferation and induced apoptosis of HepG2 cells in a concentration-dependent manner. DNA ploidy analysis showed that S phase cells were significantly decreased with increase of NS-398 concentration. The quiescent GO/G1 phase was accumulated with decrease of Bcl-2 mRNA. Whereas NS-398 had no effect on the expression of COX-2 mRNA, and no correlations were found between COX-2 mRNA and HepG2 cell proliferation and apoptosis induced by NS-398 (r=0.056 and r=0.119, respectively). Bcl-2 protein level was inhibited after treated with NS-398. CONCLUSION: NS-398 significantly inhibits the proliferation and induces apoptosis of HepG2 cells. Mechanisms involved may be accumulation of quiescent GO/G1 phase and decrease of Bcl-2 expression.
