紧密连接蛋白claudin-4在子宫内膜异位症患者在位与异位内膜组织中的表达

Expression of claudin-4 in eutopic and ectopic endometrium of women with endometriosis

目的检测紧密连接蛋白claudin-4在正常子宫内膜、子宫内膜异位症（内异症）患者的在位和异位内膜组织中的表达，评价claudin-4在内异症发病中的作用。方法选择35例内异症患者的卵巢异位内膜组织（异位内膜组），其中27例内异症患者的在位子宫内膜（在位内膜组）和35例非内异症良性卵巢、子宫疾病患者（对照组）的子宫内膜组织。透射电镜观察各组内膜组织中紧密连接的形态学变化；免疫组化和免疫印迹法检测claudin-4蛋白的表达量，RT—PCR技术检测claudin-4 mRNA的表达量。结果（1）透射电镜下，异位内膜组内膜组织中紧密连接结构消失，胶原组织丰富；在位内膜组内膜组织中紧密连接的结构与对照组内膜组织相似，未见明显变化。（2）免疫组化检测结果显示，claudin-4蛋白的阳性染色主要定位于子宫内膜腺上皮细胞膜，异位内膜组织中claudin-4的阳性染色很弱甚至缺失；在对照组、在位内膜组和异位内膜组内膜组织中，claudin-4蛋白表达量分别为89±24、84±22、27±14；claudin-4 mRNA表达量分别为14．5±6．8、13．8±9．5、2．6±2．5。异位内膜组内膜组织中claudin-4 mRNA和蛋白的表达量均低于在位内膜组和对照组内膜，差异有统计学意义（P〈0．05）。在位内膜组和对照组内膜组织中claudin-4 mRNA和蛋白的表达量分别比较，差异均无统计学意义（P〉0．05）。结论异位子宫内膜组织中claudin-4的低表达可能参与了内异症的发病。

Objective To investigate the expression of claudin-4 in the eutopic and ectopic endometrium of women with endometriosis and evaluate the role of claudin-4 in the pathogenesis of endometriosis. Methods Thirty-five women with endometriosis and 35 controls were studied. Expression of clandin-4 was investigated using immunohistochemistry, western blot and RT-PCR, respectively. Morphologic change of tight junction was also observed in different kinds of endometria. Results （ 1 ） Glandular epithelial cells of control endometrium and eutopic endometrium showed intact tight junctions in electron micrographs, whereas the morphology of tight junctions in ovarian endometriotic tissue was disrupted and collagen bundles could be easily detected. （2） The immunohistochemical staining of claudin-4 was localized to the glandular epithelial cell membrane. Deficient or weak staining was found in ovarian endometriotic tissues. In control endometrium, eutopic and ectopic endometrium of women with endometriosis, the expression of claudin-4 protein was 89 ± 24, 84 ± 22 and 27 ± 14, respectively. Relative expression of claudin-4 mRNA was 14. 5 ± 6. 8, 13. 8 ± 9. 5 and 2. 6 ± 2. 5, respectively. Expression of claudin-4 was significantly lower in the ectopic endometriotic tissue than in the eutopic endometrium and the control at both mRNA and protein levels （ P 〈 0. 05 ）. No significant difference was found between eutopic endometrium from women with endometriosis and control endometrium from women without endometriosis （P 〉0. 05）. Conclusion Down-regulated expression of claudin-4 might play a pathogenic role in the formation of endometriosis.