低温胁迫对鱼类PI3K/AKT/GSK-3β信号通路的影响

Effect of cold stress on PI3K/AKT/GSK-3β signal pathway in fishes

为探讨PI3K/AKT/GSK-3β信号通路在鱼类低温胁迫中的分子机制,利用3种抗寒能力不同的鱼类:斑马鱼(Danio rerio)、罗非鱼(Oreochromis niloticus)和草鱼(Ctenopharyngodon idellus),对其进行低温胁迫(8℃),监测这3种鱼鱼鳃中PI3K/AKT/GSK-3β信号通路中蛋白表达情况。结果表明:1)在相同低温胁迫下,3种鱼运动能力为:草鱼>斑马鱼>罗非鱼;2)Western blot结果表明:在罗非鱼中,低温抑制了p-PTEN蛋白的表达;诱导了AKT、p-AKT(Ser 473)和p-GSK-3β(Ser 9)蛋白的表达。在斑马鱼和草鱼中,低温都抑制了AKT和p-AKT(Ser473)蛋白的表达;诱导了p-GSK-3β(Ser 9)蛋白的表达。尽管低温一致性诱导p-GSK-3β(Ser 9)在3种鱼中的表达,但其呈现不同的变化倍数:罗非鱼中p-GSK-3β蛋白的上升倍数显著高于其他两种鱼。低温诱导了PI3K/AKT/GSK-3β信号通路,在不同低温耐受能力的鱼中呈现出不同的表达模式,这些物种特异性的表达模式可能会影响鱼类低温下不同的耐受能力。

To investigate the PI3K/AKT/GSK -3β signaling pathway in fish cold regulatory mechanism, three fish species, including tilapia （Oreochromis niloticus） , zebrafish （Danio rerio） and grass carp （Ctenopharyngodon-idellus）, were exposed to the cold temper- ature （8℃）. They were reared at a common temperature （28℃） hut had different cold tolerance （grass carp 〉 zebrafish 〉 tilapia）. The expression of protein in the PI3K/AKT/GSK -3β pathway were examined. Results showed that the swimming performance de- creased in turn ： grass carp, zebrafish and tilapia. In tilapia, the expression of p-PTEN was decreased at cold temperature, whereas the expression of AKT, p-AKT（Ser 473） and p-GSK -3β（Ser 9） was increased at 8℃. Both in zebrafish and in grass carp, the expres- sion of AKT, p-AKT （ Ser 473 ） was repressed at 8 ℃ , whereas the expression of p-GSK - 3 β （ Ser 9 ） was induced at 8 ℃. Although the expression of p-GSK - 3 β（ Ser 9 ） was commonly induced at cold temperature, and the increased abundance varied in the three fish species. The induction of p-GSK -3β （Ser 9 ） at 8 ℃ in tilapia was more significantly than that in other two fishes. PI3 K/AKT/GSK - 3β signaling pathway is involved in cold response and whose regulation vary in the fish species, which may contribute to the various cold tolerance of fishes.