Laboratory of Microbiology and Immunology and the Global COE Program, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan.
J Biol Chem. 2010 Feb 26;285(9):6750-60. doi: 10.1074/jbc.M109.067082. Epub 2009 Dec 16.
N-Acetylglucosamine 6-O-sulfotransferase-2 (GlcNAc6ST-2) catalyzes the sulfation of mucin-like glycoproteins, which function as ligands for a lymphocyte homing receptor, L-selectin, in the lymph node high endothelial venules (HEVs). We previously showed that GlcNAc6ST-2 is expressed not only in lymph node HEVs but also in the colonic epithelial cells in mice. Here we investigated the regulatory mechanism and physiological significance of colonic expression of GlcNAc6ST-2 in mice. Treatment of a mouse colonic epithelial cell line with butyrate, a short-chain fatty acid produced by anaerobic bacteria, induced GlcNAc6ST-2 expression in the presence of epidermal growth factor. Administration of butyrate in the drinking water stimulated GlcNAc6ST-2 expression in the mouse intestine, indicating that butyrate could serve as a regulatory molecule for the GlcNAc6ST-2 expression in vivo. Immunohistochemical analysis indicated that the sulfation of colonic mucins was greatly diminished in GlcNAc6ST-2-deficient mice. Liquid chromatography coupled to electrospray ionization tandem mass spectrometry of the colonic-mucin O-glycans from wild-type and GlcNAc6ST-2-deficient mice showed that GlcNAc-6-O-sulfation was the predominant sulfate modification of these mucins, and it was exclusively mediated by GlcNAc6ST-2. After colitis induction by dextran sulfate sodium, significantly more leukocyte infiltration was observed in the colon of GlcNAc6ST-2-deficient mice than in that of wild-type mice, indicating that the sulfation of colonic mucins by GlcNAc6ST-2 has a protective function in experimental colitis. These findings indicate that GlcNAc6ST-2, whose expression is regulated by butyrate, is a major sulfotransferase in the biosynthesis of sulfomucins in the mouse colon, where they serve as a mucosal barrier against colonic inflammation.
N-乙酰氨基葡萄糖 6-O-磺基转移酶-2（GlcNAc6ST-2）催化粘蛋白样糖蛋白的磺化，该糖蛋白作为淋巴细胞归巢受体 L-选择素在淋巴结高内皮小静脉（HEV）中的配体。我们之前表明，GlcNAc6ST-2 不仅在淋巴结 HEV 中表达，而且在小鼠的结肠上皮细胞中表达。在这里，我们研究了 GlcNAc6ST-2 在小鼠结肠中的表达的调节机制和生理意义。用短链脂肪酸丁酸盐处理小鼠结肠上皮细胞系，在表皮生长因子存在的情况下诱导 GlcNAc6ST-2 的表达。在饮用水中给予丁酸盐刺激小鼠肠道中 GlcNAc6ST-2 的表达，表明丁酸盐可以作为体内 GlcNAc6ST-2 表达的调节分子。免疫组织化学分析表明，GlcNAc6ST-2 缺陷小鼠结肠粘蛋白的硫酸化大大减少。野生型和 GlcNAc6ST-2 缺陷型小鼠结肠粘蛋白 O-聚糖的液相色谱-电喷雾串联质谱分析表明，GlcNAc-6-O-硫酸化是这些粘蛋白的主要硫酸化修饰，并且完全由 GlcNAc6ST-2 介导。葡聚糖硫酸钠诱导结肠炎后，GlcNAc6ST-2 缺陷型小鼠结肠的白细胞浸润明显多于野生型小鼠，表明 GlcNAc6ST-2 对结肠粘蛋白的硫酸化在实验性结肠炎中具有保护作用。这些发现表明，GlcNAc6ST-2 的表达受丁酸盐调节，是小鼠结肠硫酸粘蛋白生物合成中的主要磺基转移酶，在那里它们作为结肠炎症的粘膜屏障。
