RT Journal Article SR Electronic T1 Plakoglobin and HMGB1 mediate intestinal epithelial cell apoptosis induced by Clostridioides difficile TcdB JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.07.02.450318 DO 10.1101/2021.07.02.450318 A1 Yingxue Li A1 Wei Xu A1 Yutian Ren A1 Hung-Chi Cheung A1 Panpan Huang A1 Guneet Kaur A1 Chih-Jung Kuo A1 Sean P. McDonough A1 Susan L. Fubini A1 Stephen M. Lipkin A1 Xin Deng A1 Yung-Fu Chang A1 Linfeng Huang YR 2021 UL http://biorxiv.org/content/early/2021/07/03/2021.07.02.450318.abstract AB 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 γ-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.Competing Interest StatementL.H. is a founder of Xiaomo Biotech Limited (Hong Kong SAR, China), which has commercialized the pro-siRNA technology. Other authors declare no competing interests.