赭曲霉毒素A促进PCV2复制的自噬机制研究

Study on Autophagy Mechanism of Ochratoxin A Promoting PCV2 Replication

为研究赭曲霉毒素A(ochratoxin A,OTA)诱导自噬的信号通路机制,通过药物的特异性抑制信号通路中不同激酶的活性,探讨特异性激酶抑制剂在OTA诱导的自噬及猪圆环病毒2型(porcine circovirus type 2,PCV2)复制促进中的作用。结果表明:1)OTA能够抑制PCV2感染猪肾细胞株(PK-15)中的蛋白激酶B(AKT)和雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)的活性,从而增强自噬能力;2)胰岛素能够逆转OTA引起的AKT与mTOR磷酸化水平的降低,能够逆反OTA诱导产生的自噬以及PCV2的复制促进;3)OTA能够激活细胞外信号调节激酶1/2(extracellular regulated protein kinases,ERK1/2)信号通路;4)ERK1/2的抑制剂(U0126)通过降低ERK1/2的磷酸化水平,从而抑制了OTA诱导的自噬及PCV2的复制促进;5)U0126能够减少OTA引起的mTOR磷酸化水平降低的幅度。

To study the signal pathway mechanism of ochratoxin A(OTA)-induced autophagy,the activity of different kinases in the signaling pathway is specifically inhibited by medicine to explore specific kinase inhibitors role in OTA-induced autophagy and PCV2 replication promotion.The results show that OTA can inhibit the activities of AKT and mTOR in PCV2 infected PK-15 cells,thereby enhancing autophagy.Insulin treatment can reverse the decrease of AKT and mTOR phosphorylation induced by OTA,and reverse OTA induced autophagy and PCV2 replication.In the meantime,OTA can activate ERK1/2 signaling pathway,and U0126 can inhibit OTA induced autophagy and PCV2 replication by reducing ERK1/2 phosphorylation.Moreover,U0126 can also reduce the reduction of mTOR phosphorylation level caused by OTA.