O-GlcNAc修饰在谷氨酰胺诱导LPS干预的大鼠心肌细胞HSP70表达中的作用

目的 探讨O位-N-乙酰葡萄糖胺(O-GlcNAc)修饰在谷氨酰胺(Gln)诱导LPS干预的大鼠心肌细胞热休克蛋白70(HSP70)表达中的作用.方法 出生48 h的SD大鼠,原代培养心肌细胞,随机分为6组,每组11瓶(1×106个,瓶):对照组(C组)加入双蒸水25 μl;Gln组加入Gln,终浓度5 mmol/L;LPS组加入LPS,终浓度4 μg/ml;Gin+LPS组依次加入Gln和LPS,Gin终浓度5 mmol/L,LPS 终浓度4 μg/ml;Gln+LPS+Alloxan组依次加入Gln、LPS和O位-N-乙酰氨基葡萄糖转移酶抑制剂Alloxan,Gln和LPS终浓度与Gln+LPS组相同,Alloxan终浓度1 mmol/L;Gln+LPS+PUGNAc组依次加入Gln、LPS和O位-N-乙酰氨基葡萄糖苷酶抑制剂PUGNAc,Gln和LPS终浓度与Gln+LPS组相同,PUGNAc终浓度100 μmol/L.各组孵育6 h后测定心肌细胞存活率、O-GlcNAc和HSP70的表达水平.结果 各组大鼠心肌细胞存活率比较差异无统计学意义(P>0.05);与C组比较,其余组心肌细胞0.GlcNAc和HSP70的表达上调(P<0.05);与LPS组比较,Gln+LPS组和Gln+LPS+PUGNAc组心肌细胞O-GlcNAc和HSP70的表达上调(P<0.05);与Gln+LPS组比较,Gin+LPS+Alloxan组心肌细胞0-GlcNAc和HSP70的表达下调,Gln+LPS+PUGNAc组心肌细胞O-GlcNAc和HSP70的表达上调(P<0.05).结论 Gln诱导LPS干预大鼠心肌细胞HSPT0表达上调的机制可能与O-GlcNAc修饰有关.

Effects of O-GIcNAc modification on glutamine-induced heat shock protein 70 expression in LPS-treated rat cardiomyocytes

Objective To investigate the effects of O-GlcNAc modification on gintamine (Glu)-induced heat shock protein 70 (HSP70) expression in LPS-treated rat cardiomyocytes.Methods Primary cultures of neonatal rat cardiomyocytes were randomly divided into 6 groups:group Ⅰ control(group C);group Ⅱ Glu;group Ⅲ LPS;group Ⅳ Glu+LPS;group Ⅴ Glu+LPS+Alloxan and group Ⅵ Gln+LPS+PUGNAc.In group C double distilled water 25 μl was added.In group Ⅱ-Ⅵ the cells were exposed to the sanle concentrations of Glu (5 mmol/L)and LPS(4 μg/ml) except Alloxan (an inhibiter of O-linked β-N-acetyl glucosamine transferase/OGT) (1 mmol/L) and PUGNAc (an inhibitor of O-linked β-N-acetyl glucosaminidase/OGA)(100μmol/L).After being incubated for 6 h,cardiomyocyte viability,O-GlcNAc modification level and HSP70 expression level were measured.Results There was no significant difference in cell viability among the six groups.The levels of O-GlcNAc modification and HSP70 expression were significantly higher in group Ⅱ-Ⅵ than in group Ⅰ,were significantly higher in group Ⅳ and group Ⅵ than in group Ⅲ,were significantly lower in group Ⅴ and higher in group Ⅵ than in group Ⅳ.Conclusion O-GlcNAc modification may be involved in Glu-induced HSPT0 expression in LPS-treated cardiomyocytes.