细胞外基质金属蛋白酶诱导因子降解途径的初步研究

A preliminary study of extracellular matrix metalloproteinase inducer's degradation pathway

目的:观察蛋白酶体抑制剂MG-132对细胞外基质金属蛋白酶诱导因子(extracellular matrix metalloproteinase inducer,CD147)表达的影响,探讨CD147的降解途径。方法:在SY5Y细胞中分别加入0,1,2.5和5μmol/L不同浓度剂量的蛋白酶体抑制剂MG-132作用24 h后,通过Western Blot和In-cell Western的方法检测CD147的相对含量;免疫荧光双标检测SY5Y细胞中CD147与泛素(ubiquitin)的表达及共定位情况。结果:在一定时间内,随着MG-132浓度的增大,CD147的含量相对增多;与0μmol/L组比较,5μmol/L组的CD147含量在两种实验方法中分别增加了约151.81%±36.26%(P<0.05)和76.43%±18.02%(P<0.05);CD147与泛素在细胞胞体中存在共定位的特征。结论:蛋白酶体抑制剂MG-132可增加CD147的含量;CD147可被泛素化。提示CD147可能通过泛素-蛋白酶体途径进行降解。

Objective： To investigate the effect of proteasome inhibitor MG-132 on expression of extracellular matrix metalloproteinases factor（CD147） and discuss the degradation pathway of CD147. Methods： Western Blot and In-cell Western techniques were applied to investigate the changes of the relative content of CD147 after exposing to different con- centration of proteasome inhibitor MG-132 （0, 1, 2.5 and 5μmol/L） for 24 h in cultured SY5Y cells; double-labeling immunofluorescence was used to detect the expression and localization of CD147 and ubiquitin in SYSY cells. Results. In a certain period of time, with the increase of concentration of MG-132, the content of CD147 relatively increased; com- pared with 0μmol/L group, the content of CD147 of 5 μmol/L group increased by 151.81± 36.26% （ P 〈 0.05 ） and 76.43±18.02% （P 〈 0.05 ） in these two methods, respectively. CD147 and ubiquitin had co-localized characteristic in the soma. Conclusion： The role of proteasome inhibitor MG-132 can increase the content of CD147; CD147 may be ubiquitination. It suggests that CD147 may degrade through ubiquitin-proteasome pathway.