LPS促进舌苔形成相关细胞凋亡的分子机制

Mechanism of lipopolysaccharide influencing apoptosis related to the formation of tongue coating

目的探讨脂多糖影响舌苔形成相关细胞凋亡的分子机制。方法 LPS作用于撤血清舌鳞癌TCA-8113细胞,MTT法检测细胞增殖活性,Transwell研究细胞迁移,电镜观察细胞超微结构,ELISA检测PGE2含量,流式细胞术检测细胞周期和凋亡,免疫印迹检测蛋白表达。结果 12.5~100mg/L LPS可显著抑制撤血清舌鳞癌TCA-8113细胞增殖活性和细胞迁移,呈剂量依赖性。100 mg/L LPS导致细胞表面微绒毛消失、细胞线粒体肿胀空泡化、细胞内出现白色脂质样空泡结构。LPS可以改变撤血清舌鳞癌TCA-8113细胞周期分布,促进细胞凋亡,25 mg/L和50 mg/L LPS可以上调NF-κB p65、Bax、COX-2表达水平,下调NF-κB p50、Bcl-2表达水平,促进PGE2分泌,抵抗细胞快速凋亡。结论 LPS可以促进舌苔形成相关细胞凋亡,与Cox-2信号通路可能存在交互作用。

Objective To investigate the mechanism of lipopolysaccharide（ LPS） on inducing apoptosis related to the formation of tongue coating. Methods The squamous carcinoma cell line（ TCA- 8113） cultured with serum withdrawal simulated apoptosis environment of tongue coating form in vitro. TCA- 8113 cells with serum withdrawal were treated by LPS in the different doses for12,24 and 36 hours,respectively. The proliferative activity was detected by using MTT method. The effect LPS on TCA- 8113 cells with serum withdrawal migration were examined by Transwell. Inside the cell ultrastructure and cell surface ultrastructure of TCA- 8113 cells with serum withdrawal treated by LPS were detected by Transmission Electron Microscope and Scanning Electron Microscope. The level of the prostaglandin E2（ PGE2） in the cell culture supernatant was detected by enzyme- linked immunosorbent assay（ ELISA）. The flow cytometric analysis was conducted to analyze the cell cycle distribution and apoptosis. TCA- 8113 cells with serum withdrawal were treated by LPS（ 25 mg / L、50 mg / L） and the expressions of NF- κB p50,NF- κB p65,COX-2,Bcl- 2 and Bax were analyzed by Western blotting. Results To be compared with the control group,LPS obviously inhibited the proliferative activity of TCA- 8113 cells with serum withdrawal,inhibited cell migration in a dose- dependent manner,and changed internal tongue squamous cell surface ultrastructure and cell ultrastructure of TCA- 8113 cells with serum withdrawal.LPS promoted high level of PGE2 in TCA- 8113 cells with serum withdrawal culture supernatant. LPS had influence on the distribution of cell cycle and promoted apoptosis of TCA- 8113 cells with serum withdrawal. LPS significantly regulated upward the expressions of NF- κB p65,Bax,COX- 2,but regulated downward the expression of NF- κB p50,Bcl- 2. Conclusion The distinct expression of NF- κB,Bcl- 2,Bax,COX- 2,and level of PGE2 may be play roles on apoptosis related to the formation of tongue coating LPS promoted.