在血清饥饿条件下CHP2调节NHE1活性减少细胞死亡

CHP2 Regulates the Activity of NHE1 Reducing Cell Death upon to Serum Depletion

钠氢离子交换蛋白(NHE)是维持细胞内pH值等内环境稳定的重要蛋白;钙调磷酸酶B同源蛋白(CHP)是NHE的一个活性调节亚单位。研究CHP2对NHE1的调节作用时发现,在血清饥饿的条件下,PS120细胞依赖于CHP2的表达来调节外源性NHE1的活性,使细胞维持必要的钠氢交换生理活性和较高水平的细胞内pH值(pHi7.4),明显减少细胞因自身的胞浆酸性化而死亡,延长细胞存活时间(70%以上的细胞存活时间超过7天)。实验结果提示,通过研究减少CHP2表达或抑制其活性,可望找到加速细胞死亡的新方法。

The Na^＋/H^＋ exchanger （NHE） is a main protein to maintain the intraceUular pH （pHi）. Calcineurin B homologous protein （CHP） is an essential regulation cofactor for NHE. Under the condition of serum depletion in PS 120 cells, CHP2 can regulate the activity of NHE1, maintain the essential physiology activity of NHE1, promote the intracellular pH to a high level （pHi 7.4）. CHP2 also can reduce the cell death caused by self-acidification of cytoplasm and prolong time of cell survival after long serum starvation （70% cells can survive more than 7 days）. The results indicated that by means of reducing the expression of CHP2 or repressing its activity, we may get new methods to promote cell death.