N-糖链合成抑制剂对NIH3T3细胞粘附作用和整合蛋白表达的影响

研究了Ｎ－糖链合成抑制剂——Ｄｅｏｘｙｍａｎｎｏｊｉｒｉｍｙｃｉｎ（ＤＭＭ）和衣霉素（ＴＭ）对ＮＩＨ３Ｔ３细胞粘附作用和细胞表面α５β１整合蛋白含量的影响．研究结果发现甘露糖苷酶Ⅰ抑制剂－ＤＭＭ处理ＮＩＨ３Ｔ３细胞后，３Ｈ－甘露糖（３Ｈ－Ｍａｎ）参入ＮＩＨ３Ｔ３细胞较对照细胞增加一倍，多天线复杂型糖链增加１８％，而细胞表面α５β１整合蛋白与纤连蛋白粘附能力却下降１７％，但对膜整合蛋白α５和β１亚基表达量无明显影响，提示不成熟的糖链对整合蛋白参与的细胞粘附功能有一定影响，但不影响糖蛋白运输及整合到膜上．十四糖二磷酸长萜醇合成抑制剂——ＴＭ为０．５μｇ／ｍｌ时，Ｎ－糖链合成显著抑制，３Ｈ－Ｍａｎ参入减少了５２％，细胞粘附能力下降了３７％，细胞表面膜整合蛋白α５亚基下降了２２％，而β１亚基无明显变化，提示ＴＭ的脱糖基化作用可引起α５亚基转运至细胞膜表面下降，以至影响了细胞的粘附能力．此外，脱糖整合蛋白与纤连蛋白（ｆｉｂｒｏｎｅｃｔｉｎ，Ｆｎ）的结合力下降也是原因之一．

The Effects of Inhibitor of N Oligosaccharide Chains on Adhesions of NIH3T3 Cells and Expressions of Integrins

To study the effects of Deoxymannojirimycin (DMM) and Tunicamycin (TM) on the ability of NIH3T3 cell adhesion and α 5β 1 integrin content on the cell surface were studied. Having investigate the adhesion of NIH3T3 cells to Fn and α 5β 1 integrin content on the cell surface after using the inhibtors of synthesis of oligosacharides chain, it was found that 3H mannose incorpora tion increased 100%, tri tetraantenny complex type of N oligosaccharides increased 18%, the ability of NIH3T3 cell adhesion fibronectin (Fn) decrease 17% and the α 5β 1 integrin content remains the same after DMM treated to NIH3T3 cell. And after TM (0.5 μg/ml)treatment, the 3H mannose incorporation decrease 52%, the cell adhesion ability decreased 37%, and so did 22% of α 5 integrin content. But it had no influence on β 1 content. It suggests the immature oligosaccharides may influence the ability of cell adhesion and may not affect the transport of glycoprotein to membrane. It seens that deglycolytion caused by TM treated may influence the α 5 subunit transportion to cell surface, resulting in the decline of cell adhesive ability. Besides, deglycosylated integrin may also decrease the cell adhesive ability.