尼古丁对成牙本质细胞凋亡影响的实验研究

Effect of nicotine on the apoptosis of odontoblasts

目的：探讨尼古丁刺激对小鼠成牙本质细胞凋亡的影响。方法：将培养的小鼠成牙本质样细胞系MDPC-23分为4组：0、1、10、100μg/m L不同浓度尼古丁处理组,分别进行Hoechst 33258染色观察细胞形态变化,Western blot检测细胞凋亡相关蛋白Bcl-2、Bax、Caspase-3以及p-JNK等的表达。另设尼古丁和JNK抑制剂SP600125共同作用组,检测Caspase-3表达。结果：0~100μg/m L范围内,随着尼古丁浓度增加,细胞形态逐渐出现凋亡变化,Bcl-2表达下调和Bax、Caspase-3表达上调等趋势均逐渐明显;尼古丁单独作用下p-JNK表达增强,并呈现一定时间依赖性和浓度依赖性;尼古丁和SP600125共同作用下,Caspase-3表达明显降低。结论：尼古丁对小鼠成牙本质细胞有毒性作用,一定程度上可促进细胞的凋亡。

AIM： To investigate the effects of nicotine on the apoptosis of mouse odontoblasts MDPC-23.METHODS： Cultured MDPC-23 cells were treated with nicotine（ μg / m L） at 0（ control group）,1,10 and 100 respectively. After treatment,cell morphology changes were detected by Hoechst staining,and the expression of apoptosis- related proteins of Bcl-2,Bax,Caspase-3 and p-JNK were respectively determined by Western blot. A combination of nicotine and JNK inhibitor SP600125 were also added to MDPC-23 cell culture and the expression of Caspase-3 were examined. RESULTS： With the increase of nicotine concentration（0 ~ 100 μg / m L）,the cell morphology distinctly changed. The expression of Bcl-2 were downregulated and the expression of Bax,Caspase- 3 were upregulated gradually. Meanwhile,the expression of p-JNK were increased by nicotine in a dose- and time-dependent manner.Whereas,SP600125 could inhibit the nicotine- induced expresssion of Caspase- 3. CONCLUSION： Nicotine has toxic effects on MDPC-23 cells,which may promote the apoptosis of odontoblasts to some extent.