up-regulation of muc2 and il-1β expression in human colonic epithelial cells by shigella and its interaction with mucins老年病muc2和il-1β表达在人类结肠上皮细胞与黏蛋白由志贺氏杆菌及其交互.pdf

Up-Regulation of MUC2 and IL-1b Expression in Human Colonic Epithelial Cells by Shigella and Its Interaction with Mucins 1 1 2 Radhakrishnan Prakash , Subramaniya Bharathi Raja , Halagowder Devaraj , Sivasitambaram Niranjali Devaraj1* 1 Department of Biochemistry, University of Madras, Guindy Campus, Chennai, Tamilnadu, India, 2 Unit of Biochemistry, Department of Zoology, University of Madras, Guindy Campus, Chennai, Tamilnadu, India Abstract Background: The entire gastrointestinal tract is protected by a mucous layer, which contains complex glycoproteins called mucins. MUC2 is one such mucin that protects the colonic mucosa from invading microbes. The initial interaction between microbes and mucins is an important step for microbial pathogenesis. Hence, it was of interest to investigate the relationship between host (mucin) and pathogen interaction, including Shigella induced expression of MUC2 and IL-1b during shigellosis. Methods: The mucin-Shigella interaction was revealed by an in vitro mucin-binding assay. Invasion of Shigella dysenteriae into HT-29 cells was analyzed by Transmission electron microscopy. Shigella induced mucin and IL-1b expression were analyzed by RT-PCR and Immunofluorescence. Results: The clinical isolates of Shigella were found to be virulent by a congo-red binding assay. The in vitro mucin-binding assay revealed both Shigella dysenteriae and Shigella flexneri have binding affinity in the increasing order of: guinea pig small intestinal mucin,guinea pig colonic mucin, Human colonic mucin. Invasion of Shigella dysenteriae into HT-29 cells occurs within 2 hours. Interestingly, in Shigella dysenteriae infected conditions, significant increases in mRNA expression of MUC2 and IL