Plakoglobin and HMGB1 mediate intestinal epithelial cell apoptosis induced by Clostridioides difficile TcdB

Li, Y.; Xu, W.; Ren, Y.; Cheung, H.-C.; Huang, P.; Kaur, G.; Kuo, C.-J.; McDonough, S. P.; Fubini, S. L.; Lipkin, S. M.; Deng, X.; Chang, Y.-F.; Huang, L.

doi:10.1101/2021.07.02.450318

bioRxiv · 10.1101/2021.07.02.450318

Plakoglobin and HMGB1 mediate intestinal epithelial cell apoptosis induced by Clostridioides difficile TcdB

Li, Y.·Xu, W.·Ren, Y.·Cheung, H.-C.·Huang, P.·Kaur, G.·Kuo, C.-J.·McDonough, S. P.·Fubini, S. L.·Lipkin, S. M.·Deng, X.·Chang, Y.-F.·Huang, L.

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Abstract

Clostridioides difficile infection (CDI) is the leading cause of antibiotic-associated intestinal disease, resulting in severe diarrhea and fatal pseudomembranous colitis. TcdB, one of the essential virulence factors secreted by this bacterium, induces host cell apoptosis through a poorly understood mechanism. Here, we performed an RNAi screen customized to Caco-2 cells, a cell line model of the intestinal epithelium, to discover host factors involved in TcdB-induced apoptosis. We identified plakoglobin, also known as junction plakoglobin (JUP) or {gamma}-catenin, a member of the catenin family, as a novel host factor, and a previously known cell death-related chromatin factor, high mobility group box 1 (HMGB1). Disruption of those host factors by RNAi and CRISPR resulted in resistance of cells to TcdB-mediated and mitochondria-dependent apoptosis. JUP was redistributed from adherens junctions to the mitochondria and colocalized with Bcl-XL after stimulation by TcdB, suggesting a role of JUP in cell death signaling through mitochondria. Treatment with glycyrrhizin, an HMGB1 inhibitor, resulted in significantly increased resistance to TcdB-induced epithelial damage in cultured cells and a mouse ligated colon loop model. These findings demonstrate the critical roles of JUP and HMGB1 in TcdB-induced epithelial cell apoptosis.

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Li, Y., Xu, W., Ren, Y., Cheung, H.-C., Huang, P., Kaur, G., Kuo, C.-J., McDonough, S. P., Fubini, S. L., Lipkin, S. M., Deng, X., Chang, Y.-F., Huang, L.. 2021-07-03. Plakoglobin and HMGB1 mediate intestinal epithelial cell apoptosis induced by Clostridioides difficile TcdB. https://doi.org/10.1101/2021.07.02.450318

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