Role of chitin and chitinase/chitinase-like proteins in inflammation, tissue remodeling, and injury.
The 18 glycosyl hydrolase family of chitinases is an ancient gene family that is widely expressed from prokaryotes to eukaryotes. In mammals, despite the absence of endogenous chitin, a number of chitinases and chitinase-like proteins (C/CLPs) have been identified. However, their roles have only recently begun to be elucidated. Acidic mammalian chitinase (AMCase) inhibits chitin-induced innate inflammation; augments chitin-free, allergen-induced Th2 inflammation; and mediates effector functions of IL-13. The CLPs BRP-39/YKL-40 (also termed chitinase 3-like 1) inhibit oxidant-induced lung injury, augments adaptive Th2 immunity, regulates apoptosis, stimulates alternative macrophage activation, and contributes to fibrosis and wound healing. In accord with these findings, levels of YKL-40 in the lung and serum are increased in asthma and other inflammatory and remodeling disorders and often correlate with disease severity. Our understanding of the roles of C/CLPs in inflammation, tissue remodeling, and tissue injury in health and disease is reviewed below.
Section of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520-8057, USA.
Chun Geun
CG
Lee
Carla A
CA
Da Silva
Charles S
CS
Dela Cruz
Farida
F
Ahangari
Bing
B
Ma
Min-Jong
MJ
Kang
Chuan-Hua
CH
He
Seyedtaghi
S
Takyar
Jack A
JA
Elias
D054392:Adipokines; D056151:Airway Remodeling / Q000502:physiology*; D000818:Animals; D017209:Apoptosis / Q000276:immunology; D050197:Atherosclerosis / Q000201:enzymology / Q000276:immunology; D002686:Chitin / Q000276:immunology / Q000378:metabolism*; D000071451:Chitinase-3-Like Protein 1; D002688:Chitinases / Q000276:immunology / Q000378:metabolism*; D003920:Diabetes Mellitus / Q000201:enzymology / Q000276:immunology; D013700:Giant Cell Arteritis / Q000201:enzymology / Q000276:immunology; D006023:Glycoproteins / Q000097:blood / Q000502:physiology; D006801:Humans; D007249:Inflammation / Q000201:enzymology*; D037102:Lectins / Q000097:blood / Q000502:physiology; D008171:Lung Diseases / Q000201:enzymology / Q000276:immunology; D051379:Mice; D009369:Neoplasms / Q000201:enzymology / Q000276:immunology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology
D054392:Adipokines; C084533:CHI3L1 protein, human; C509289:Chil1 protein, mouse; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D037102:Lectins; D002686:Chitin; D002688:Chitinases