title: Carbohydrate-binding motif in chitinase 3-like 1 (CHI3L1/YKL-40) specifically activates Akt signaling pathway in colonic epithelial cells.
abstract: Host-microbial interactions play a key role during the development of colitis. We have previously shown that chinase 3-like 1 (CHI3L1) is an inducible molecule overexpressed in colonic epithelial cells (CECs) under inflammatory conditions. In this study, we found that chitin-binding motif (CBM) of CHI3L1 is specifically associated with the CHI3L1-mediated activation of the Akt-signaling in CEC by transfecting the CBM-mutant CHI3L1 vectors in SW480 CECs. Downstream, CHI3L1 enhanced the secretion of IL-8 and TNFα in a dose-dependent manner. We previously show that 325 through 339 amino-acids in CBM are crucial for the biological function of CHI3L1. Here we demonstrated that 325th-339th residues of CBM in CHI3L1 is a critical region for the activation of Akt, IL-8 production, and for a specific cellular localization of CHI3L1. In conclusion, CBM region of CHI3L1 is critical in activating Akt signaling in CECs, and the activation may be associated with the development of chronic colitis.
authors.affiliation: Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Chun-Chuan
authors.initials: CC
authors.lastname: Chen
authors.forename: Victoria
authors.initials: V
authors.lastname: Llado
authors.forename: Katrin
authors.initials: K
authors.lastname: Eurich
authors.forename: Hoa T
authors.initials: HT
authors.lastname: Tran
authors.forename: Emiko
authors.initials: E
authors.lastname: Mizoguchi
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D002460:Cell Line; D000071451:Chitinase-3-Like Protein 1; D003106:Colon / Q000201:enzymology*; D004847:Epithelial Cells / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis; D051379:Mice; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: C509289:Chil1 protein, mouse; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D051057:Proto-Oncogene Proteins c-akt