GLUCOSE-INDUCED CHANGES IN NA+/H+ ANTIPORT ACTIVITY AND GENE-EXPRESSION IN CULTURED VASCULAR SMOOTH-MUSCLE CELLS - ROLE OF PROTEIN-KINASE-C
GLUCOSE-INDUCED CHANGES IN NA+/H+ ANTIPORT ACTIVITY AND GENE-EXPRESSION IN CULTURED VASCULAR SMOOTH-MUSCLE CELLS - ROLE OF PROTEIN-KINASE-C
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DOI：
10.1172/jci117275
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发表时间：
1994-06-01
影响因子：
15.9
通讯作者：
HOWARD, RL
中科院分区：
文献类型：
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作者：
WILLIAMS, B;HOWARD, RL
Na+/H+逆向转运活性增加与高血压和糖尿病血管疾病的发病机制有关。因此，在培养的大鼠血管平滑肌细胞（VSMC）的Na+/H+逆向转运活性的细胞外葡萄糖浓度升高的独立影响进行了研究。与对照培养基（5 mM）相比，暴露于高葡萄糖培养基（20 mM）3和24 h后，VSMC对阿米洛利敏感的Na-22（+）摄取显著增加两倍。直接葡萄糖诱导的Na+/H+反向转运激活通过测量细胞内酸中毒的Na+依赖性细胞内pH恢复来证实。高糖显著增加VSMC中蛋白激酶C（PKC）活性，H-7、星形孢菌素或先前PKC下调抑制PKC活化可防止葡萄糖诱导的VSMC中Na+/H+反向转运活性增加。北方分析显示高糖24 h可诱导VSMC poly A（+）mRNA增加3倍。用放线菌素D抑制NHE-1 mRNA的这种增加可防止葡萄糖诱导的Na+/H+反向转运活性的持续增加。总之，葡萄糖浓度升高通过葡萄糖诱导的PKC依赖性机制显著影响血管Na+/H+逆向转运活性，从而为高血压和糖尿病患者血管组织中Na+/H+逆向转运活性增加提供了生化基础。
Increased Na+/H+ antiport activity has been implicated in the pathogenesis of hypertension and vascular disease in diabetes mellitus. The independent effect of elevated extracellular glucose concentrations on Na+/H+ antiport activity in cultured rat vascular smooth muscle cells(VSMC) was thus examined. Amiloride-sensitive Na-22(+) uptake by VSMC significantly increased twofold after 3 and 24 h of exposure to high glucose medium(20 mM) vs. control medium(5 mM). Direct glucose-induced Na+/H+ antiport activation was confirmed by measuring Naf-dependent intracellular pH recovery from intracellular acidosis. High glucose significantly increased protein kinase C (PKC) activity in VSMC and inhibition of PKC activation with H-7, staurosporine, or prior PKC downregulation prevented glucose-induced increases in Na+/H+ antiport activity in VSMC. Northern analysis of VSMC poly A(+) RNA revealed that high glucose induced a threefold increase in Na+/H+ antiport(NHE-1) mRNA at 24 h. Inhibiting this increase in NHE-1 mRNA with actinomycin D prevented the sustained glucose-induced increase in Na+/H+ antiport activity. In conclusion, elevated glucose concentrations significantly influence vascular Na+/H+ antiport activity via glucose-induced PKC dependent mechanisms, thereby providing a biochemical basis for increased Na+/H+ antiport activity in the vascular tissues of patients with hypertension and diabetes mellitus.