【摘要】 目的了解微囊藻毒素(MC)LR对L-02细胞的毒性机制。方法以L-02细胞为材料,用不同浓度的MCLR处理该细胞,观察了细胞增殖能力、细胞形态改变、乳酸脱氢酶(LDH)泄漏、细胞凋亡率及凋亡相关基因等一系列指标的变化。结果 MTT细胞增殖实验可知,MCLR在24 h内对L-02细胞有轻微的抑制作用,随后却促进细胞增殖。48 h处理对 LDH泄漏没有显著影响,延时处理导致LDH泄漏发生,且MCLR浓度越高,LDH泄漏越严重,此结果显示发生了细胞氧化损伤。光镜下50μg/ml的毒素浓度在60 h处理后可造成明显的细胞形态改变,如细胞变圆、不贴壁、萎缩、膜发泡,这些都是典型的细胞凋亡形态变化。36 h不同浓度MCLR处理的细胞凋亡率较低,约为22％～29％．延长处理时间至60 h,高浓度(50μg／ml)处理的L-02细胞的凋亡率可达80％。经高浓度MCLR处理60 h的L-02细胞中,p53和 Bcl-2基因产物大量表达。结论微囊藻毒素LR可诱导L-02发生凋亡并上调凋亡相关基因p53和bcl-2的表达。更多还原

【Abstract】 Objective To investigate the toxicological mechanism of microcystin-LR (MCLR) on L-02 cells. Methods L-02 cells was treated with MCLR at different concentrations and the subsequent changes such as cell proliferation (MTT assay), morphology, lactate dehydrogenase (LDH) leakage, apoptosis rate and apoptosis-related gene expression were examined. Results MTT assay showed that MCLR mildly inhibited the cell growth within the initial 24 h of treatment but enhanced the cell viability after that till 60 h in a time- and dose-dependent manner. LDH leakage underwent no marked changes in response to 48-hour MCLR treatment but increased upon prolonged treatment for 60 h, indicating the presence of oxidative damage. After a 48-h treatment with MCLR at 50 μg/ml, obvious apoptosis of L-02 cells occurred as manifested by cell rounding, detachment from the substrate, cell shrinkage and membrane blebbing. The apoptosis rates were rather low (between 22%and 29%) after treatment with MCLR at different concentrations for 36 h, and increased to as much as 80% after a 60-h treatment with 50 μg/ml MCLR. The expressions of p53 and bcl-2 increased in the cells after treatment with high-concentration MCLR, suggesting that MCLR up-regulated the expression levels of the two proteins. Conclusion MCLR can induce apoptosis and up-regulate p53 and bcl-2 expressions in human normal liver cell line L-02.更多还原