Osteopontin Deficiency Accelerates Spontaneous Colitis in Mice with Disrupted Gut Microbiota and Macrophage Phagocytic Activity

• Published in: PloS one Vol. 10; no. 8; p. e0135552
• Main Authors: Toyonaga, Takahiko, Nakase, Hiroshi, Ueno, Satoru, Matsuura, Minoru, Yoshino, Takuya, Honzawa, Yusuke, Itou, Ayako, Namba, Kazuyoshi, Minami, Naoki, Yamada, Satoshi, Koshikawa, Yorimitsu, Uede, Toshimitsu, Chiba, Tsutomu, Okazaki, Kazuichi
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 14.08.2015; Public Library of Science (PLoS)
• Subjects: Abundance; Animal models; Animals; Bacteria; Biocompatibility; Biomedical materials; Clonal deletion; Colitis; Colitis - etiology; Colitis - microbiology; Colon; Comparative analysis; Cytokines; Dendritic cells; Digestive system; Digestive tract; Disease Models, Animal; E coli; Epithelial cells; Fluorescence; Fluorescence in situ hybridization; Gastroenterology; Gastrointestinal diseases; Gastrointestinal Microbiome - genetics; Gastrointestinal tract; Hepatology; Hydroxyapatite; Inflammation; Inflammatory bowel disease; Inflammatory bowel diseases; Inflammatory Bowel Diseases - etiology; Interleukin 10; Interleukin-10 - genetics; Interleukin-10 - metabolism; Intestinal microflora; Intestine; Laboratory animals; Macrophages; Macrophages, Peritoneal - physiology; Medicine; Mice; Mice, Inbred C57BL; Mice, Knockout; Microbiota; Microbiota (Symbiotic organisms); Osteopontin; Osteopontin - deficiency; Osteopontin - metabolism; Phagocytes; Phagocytosis; Polymorphism; Proteins; Restriction fragment length polymorphism; Rodents; Tissues; Tumor necrosis factor-TNF; Japan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0135552

Osteopontin (OPN) is a multifunctional protein expressed in a variety of tissues and cells. Recent studies revealed increased OPN expression in the inflamed intestinal tissues of patients with inflammatory bowel disease (IBD). The role of OPN in the pathophysiology of IBD, however, remains unclear. To investigate the role of OPN in the development of intestinal inflammation using a murine model of IBD, interleukin-10 knock out (IL-10 KO) mice. We compared the development of colitis between IL-10 KO and OPN/IL-10 double KO (DKO) mice. OPN expression in the colonic tissues of IL-10 KO mice was examined by fluorescence in situ hybridization (FISH) analysis. Enteric microbiota were compared between IL-10 KO and OPN/IL-10 DKO mice by terminal restriction fragment length polymorphism analysis. The effect of OPN on macrophage phagocytic function was evaluated by phagocytosis assay. OPN/IL-10 DKO mice had an accelerated onset of colitis compared to IL-10 KO mice. FISH analysis revealed enhanced OPN synthesis in the colonic epithelial cells of IL-10 KO mice. OPN/IL-10 DKO mice had a distinctly different enteric bacterial profile with a significantly lower abundance of Clostridium subcluster XIVa and a greater abundance of Clostridium cluster XVIII compared to IL-10 KO mice. Intracellular OPN deletion in macrophages impaired phagocytosis of fluorescence particle-conjugated Escherichia coli in vitro. Exogenous OPN enhanced phagocytosis by OPN-deleted macrophages when administered at doses of 1 to 100 ng/ml, but not 1000 ng/ml. OPN deficiency accelerated the spontaneous development of colitis in mice with disrupted gut microbiota and macrophage phagocytic activity.