环孢素对大鼠牙龈上皮细胞凋亡及Bcl-2、Caspase-3蛋白表达的影响

Apoptosis and expression of Bcl-2 and Caspase-3 in Ciclosporin-induced gingival overgrowth of rats

目的观察环孢素(CsP)对大鼠牙龈上皮细胞凋亡活动、凋亡相关蛋白Bcl-2和Caspase-3表达的影响,探讨CsP致牙龈上皮增厚的可能机制。方法 SPF级7周龄雄性Wistar大鼠80只,随机分为实验组和对照组,每组又分为10、20、30、40 d亚组,实验组胃饲含CsP鲜牛奶,对照组胃饲等量鲜牛奶。经心灌注4%多聚甲醛,固定取材,制作下颌第一磨牙颊舌向石蜡切片,原位缺口末端标记(TUNEL)法检测牙龈上皮细胞原位凋亡,免疫组化PV两步法检测Bcl-2和Caspase-3蛋白的表达。利用图像分析系统计算牙龈上皮细胞凋亡率和Caspase-3蛋白阳性细胞表达率,并测量Bcl-2蛋白平均灰度,行完全随机分组两因素析因设计方差分析。结果实验组大鼠牙龈上皮内细胞凋亡率和Caspase-3蛋白阳性细胞表达率下调,与对照组有显著差异(P<0.05)。实验组大鼠牙龈上皮内Bcl-2蛋白平均灰度上调,与对照组有显著差异(P<0.05)。结论环孢素导致牙龈上皮增厚可能与干扰线粒体凋亡途径、抑制细胞凋亡有关。

Objective To observe the effect of Ciclosporin（CsP） on apoptosis and expression of the associated protein Bcl-2,Caspase-3 in gingival epithelium of rats in order to approach the mechanism of CsP-induced gingival epithelium overgrowth.Methods Eighty SPF grade male 7-week-old Wistar rats were randomly divided into experi-mental group and control group,and each group was divided into 4 subgroups according to the duration of treatment（10,20,30 and 40 days）.The experimental objects were given fresh milk including CsP intragastrically and the control ones were given only fresh milk.After perfusion of 4% paraform for internal fixation,the specimens＇ bucco-lingual paraffin sections at lower first molar were made.Apoptosis was detected using TdT-mediated dUT nick end labeling（TUNEL） and the expression of Bcl-2 and Caspase-3 using immunohistochemisty of PV.The apoptotic index,positive cell rate of Caspase-3 and average gray scale of Bcl-2 was measured with an image analysis system.Data were analyzed by two-way analysis of variance of factorial design.Results The apoptosis index and positive cell rate of Caspase-3 were downregulated in the experimental group,and were significant difference from the control group（P0.05）.The average gray scale of Bcl-2 was up-regulated in the experimental group,and was significant difference from the control group（P0.05）.Conclusion CsP-induced gingival epithelial overgrowth is likely to associated with interference to the path of mito-chondrial apoptosis and inhibition apoptosis.