Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico.
Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico.
Cell Microbiol. 2017 Nov;19(11). doi: 10.1111/cmi.12761. Epub 2017 Jul 18.
Entamoeba histolytica trophozoites adhere to epithelium at the cell-cell contact and perturb tight junctions disturbing the transepithelial electrical resistance. Behind tight junctions are the adherens junctions (AJs) that reinforce them and the desmosomes (DSMs) that maintain the epithelium integrity. The damage produced to AJs and DMSs by this parasite is unknown. Here, we studied the effect of the trophozoites, the EhCPADH complex, and the EhCP112 recombinant enzyme (rEhCP112) on AJ and DSM proteins. We found that trophozoites degraded β-cat, E-cad, Dsp l/ll, and Dsg-2 with the participation of EhCPADH and EhCP112. After contact of epithelial cells with trophozoites, immunofluorescence and transmission electron microscopy assays revealed EhCPADH and rEhCP112 at the intercellular space where they colocalised with β-cat, E-cad, Dsp l/ll, and Dsg-2. Moreover, our results suggested that rEhCP112 could be internalised by caveolae and clathrin-coated vesicles. Immunoprecipitation assays showed the interaction of EhCPADH with β-cat and Dsp l/ll. Besides, in vivo assays demonstrated that rEhCP112 concentrates at the cellular borders of the mouse intestine degrading E-cad and Dsp I/II. Our research gives the first clues on the trophozoite attack to AJs and DSMs and point out the role of the EhCPADH and EhCP112 in the multifactorial event of trophozoites virulence.
溶组织内阿米巴滋养体在细胞-细胞接触处黏附在上皮细胞上，并扰乱紧密连接，破坏上皮细胞间的电阻。在紧密连接后面是黏附连接（AJs），它加强了紧密连接，桥粒（DSMs）则维持了上皮细胞的完整性。这种寄生虫对 AJs 和 DSMs 的破坏程度尚不清楚。在这里，我们研究了滋养体、EhCPADH 复合物和 EhCP112 重组酶（rEhCP112）对 AJ 和 DSM 蛋白的影响。我们发现滋养体在 EhCPADH 和 EhCP112 的参与下降解了β-cat、E-cad、Dsp l/ll 和 Dsg-2。上皮细胞与滋养体接触后，免疫荧光和透射电子显微镜检测显示 EhCPADH 和 rEhCP112 位于细胞间隙，与β-cat、E-cad、Dsp l/ll 和 Dsg-2 共定位。此外，我们的结果表明 rEhCP112 可以被小窝和网格蛋白包被囊泡内化。免疫沉淀检测显示 EhCPADH 与β-cat 和 Dsp l/ll 的相互作用。此外，体内实验表明 rEhCP112 集中在小鼠肠道的细胞边界，降解 E-cad 和 Dsp I/II。我们的研究首次揭示了滋养体对 AJs 和 DSMs 的攻击，并指出了 EhCPADH 和 EhCP112 在滋养体毒力这一多因素事件中的作用。
