Flacke Jan-Paul, Kumar Sanjeev, Kostin Sawa, Reusch H Peter, Ladilov Yury
Department of Clinical Pharmacology, Ruhr-University Bochum, Universitätsstr. 150, 44801 Bochum, Germany.
Apoptosis. 2009 Jan;14(1):90-6. doi: 10.1007/s10495-008-0287-5.
To analyze the underlying cellular mechanisms of adaptation to ischemia-induced apoptosis through short acidic pretreatment, i.e. acidic preconditioning (APC), Wistar rat coronary endothelial cells (EC) were exposed for 40 min to acidosis (pH 6.4) followed by a 14 h recovery period (pH 7.4) and finally treated for 2 h with simulated in vitro ischemia (glucose-free anoxia at pH 6.4). APC led to a transient activation of p38 and Akt kinases, but not of JNK and ERK1/2 kinases, which was accompanied by significant reduction of the apoptotic cell number, caspase-12/-3 cleavage and Bcl-xL overexpression. These effects of APC were completely abolished by prevention of Akt- or p38-phosphorylation during APC. Furthermore, knock-down of Bcl-xL by siRNA-transfection also abolished the anti-apoptotic effect of APC. Therefore, APC leads to protection of EC against ischemic apoptosis by activation of Akt and p38 followed by overexpression of Bcl-xL, which is a key anti-apoptotic mechanism of APC.
为了分析通过短期酸性预处理即酸性预处理（APC）适应缺血诱导凋亡的潜在细胞机制，将Wistar大鼠冠状动脉内皮细胞（EC）暴露于酸中毒（pH 6.4）40分钟，随后恢复期14小时（pH 7.4），最后用模拟体外缺血（pH 6.4下无糖缺氧）处理2小时。APC导致p38和Akt激酶短暂激活，但JNK和ERK1/2激酶未激活，同时凋亡细胞数量显著减少，caspase-12/-3裂解和Bcl-xL过表达。在APC期间通过阻止Akt或p38磷酸化，APC的这些作用被完全消除。此外，通过siRNA转染敲低Bcl-xL也消除了APC的抗凋亡作用。因此，APC通过激活Akt和p38，随后Bcl-xL过表达，导致EC对缺血性凋亡的保护，这是APC的关键抗凋亡机制。
