目的 研究白花丹醌对瘦素刺激的体外培养人肝星状细胞（HSC-LX2）细胞周期及周期相关蛋白表达的影响，探讨白花丹醌抗肝纤维化的作用机制。方法 ELISA法检测HSC-LX2细胞培养上清液中自分泌瘦素水平。将HSC-LX2细胞分成对照组，瘦素组，白花丹醌2、8 μmol/L组，秋水仙碱6.25 μg/mL阳性对照组。除对照组外，其余各组细胞用瘦素100 μg/mL刺激24 h、再与药物共同培养24 h后，流式细胞仪检测HSC-LX2细胞周期，Western blotting法检测细胞周期相关蛋白cyclin D1、cyclin E1、p21的表达。结果 HSC-LX2细胞自分泌瘦素的浓度先随着培养时间的延长而递减，24 h达到低谷值，48 h后又升至6 h水平，每个时间点分泌的瘦素量无显著差异（P＞0.05）。与对照组相比，瘦素组HSC-LX2细胞增殖能力显著增强，S期和G₂/M期细胞比例显著增加；而白花丹醌2、8 μmol/L干预后，HSC-LX2细胞G₀/G₁期细胞的比例明显提高，而S期和G₂/M期细胞比例明显降低，且呈明显的浓度相关性。与对照组比较，瘦素组HSC-LX2细胞经瘦素刺激后细胞周期相关蛋白cyclin D1、cyclin E1的量显著增加，p21蛋白的表达受到抑制；白花丹醌2、8 μmol/L和秋水仙碱明显降低cyclin Dl、cyclin E1蛋白水平，增强p21蛋白表达。结论 白花丹醌可明显抑制瘦素诱导的HSC-LX2细胞增殖，该作用主要是通过抑制细胞由G₀/G₁期向S期转变而产生的，作用机制可能与其降低cyclin Dl、cyclin E1蛋白水平，增加p21蛋白表达相关。

Objective To investigate the effects of plumbagin on cell cycle of human hepatic satellite cells (HSC-LX2) stimulated by leptin in vitro and its expression of related proteins, so as to explore the mechanism of anti-hepatic fibrosis of plumbagin. Methods The level of autocrine leptin in culture supernate of HSC-LX2 was measured by ELISA. HSC-LX2 were divided into control, model (leptin), plumbagin low- and high-dose (2 and 8 μmol/L), and colchicines (6.25 μg/mL) groups. In addition to the control group, the other groups were stimulated by leptin (100 μg/mL) for 24 h and treated with plumbagin at different concentration and colchicine for 24 h later. HSC-LX2 cell cycle was detected by flow cytometry (FCM) and the expression of cell cycle-related proteins of cyclin D1, cyclin E1, and p21 were tested by Western blotting. Results The concentration of autocrine leptin in HSC-LX2 decreased with cultural time prolonging, the minimum time was at 24 h and after 48 h the level recovered to original level of 6 h (P < 0.05). There was no significant difference in concentration of autocrine leptin at each time point (P > 0.05). FCM analysis showed that in model group HSC-LX2 cell proliferation and cell number ratio of S and G₂/M phases significantly increased compared with the control group. At 24 h after addition of plumbagin (2 and 8 μmol/L), the percentage of HSC-LX2 at G₀/G₁ phase was apparent increased, while the total percentage of HSC-LX2 cells at S and G₂/M phases was apparent decreased in a dose-dependent manner. Compared with the control group, the stimulation by leptin significantly increased the contents of cyclin D1 and cyclin E1 in HSC-LX2, and inhibited the expression of p21 protein. However, plumbagin (2 and 8 μmol/L) and colchicine significantly decreased the level of cyclin D1 and cyclin E1 and increased the expression of p21 protein. Conclusion Plumbagin could significantly inhibit the proliferation of HSC-LX2 induced by leptin through blocking HSC-LX2 to enter S phase from G₀/G₁ phase. Its mechanism might be related to the decrease of the expressions of cyclin D1 and cyclin E1 and the increase of p21 protein expression.

国家自然科学基金资助项目（30760321）；广西高等学校优秀人才资助项目（J11065）；广西教育厅科研项目（200103YB083）