PFK-1关键位点磷酸化改变干扰葡萄糖代谢在博尔纳病毒引起5-HT紊乱和学习记忆障碍中的机制研究

Borna disease virus (BDV) infection is closely related to human mental illness and induces cognitive impairment. It is known that BDV infection disturbs serotonin(5-HT) and other neurotransmitters which in turn lead to learning and memory impairment in infected animals. Our early study found BDV infection interfere with energy metabolism of host cell. However, the mechanism of BDV infection disturbing energy metabolism remains elusive. Post-translational modifications of specific proteinic sites play a key role in regulating protein activity. We recently found the decreased enzyme activity and decreased phosphorylation of PFK-1, the key enzyme of glucose metabolism, with its unchanging PFK-1protein expression in BDV infected cells. Therefore, we propose BDV infection disturbs neurotransmitter uptake and release , animal's learning and memory impairment through reducing the phosphorylation on key PFK-1 sites which will down regulate the PFK-1 activity. In this study, first, we will identify the PFK-1 sites with significantly changed phosphorylation in BDV infected cells, from which we will test and select the sites which can reduce PFK-1 activity and disturb glucose metabolism. Second, we will verify the key phosphorylated sites of PFK-1 by checking glucose metabolism, 5-HT uptake or release and animal behavior study in BDV infected animals. In the present study , the pathogenesis of BDV infection through BDV interfering energy metabolism will be discussed from the perspective of protein post-translational modification and the novel targets for the prevention of the disease will be provide.

博尔纳病毒(BDV)感染和人类精神疾病密切相关，引起认知障碍。已知BDV感染引起5羟色胺(5-HT)等神经递质紊乱，导致感染动物的学习记忆障碍。课题组前期研究证实BDV感染干扰宿主细胞能量代谢。但是，BDV导致能量代谢紊乱的机制不清。 我们近期实验发现BDV感染后糖代谢关键酶PFK-1表达无改变但磷酸化修饰水平下降、酶活性降低，为此提出BDV通过抑制PFK-1关键位点磷酸化，下调了PFK-1活性，引起葡萄糖代谢紊乱，导致感染动物5羟色胺紊乱和学习记忆障碍的假说。拟进行：在细胞水平全面鉴定BDV感染后PFK-1出现显著磷酸化改变的位点，验证出导致酶活性下降和糖代谢紊乱的特定位点，然后在动物水平通过葡萄糖代谢检测、5-HT产量和传递检测、动物行为学观察，鉴定出PFK-1的关键磷酸化修饰位点。本研究在蛋白质翻译后修饰水平对BDV干扰能量代谢而致病进行探讨，并为该病的防治提供新靶点。

博尔纳病毒（BDV）感染和人类精神疾病密切相关，引起认知障碍。已知BDV感染引起5羟色胺（5-HT）等神经递质紊乱，但是BDV导致能量代谢紊乱的机制不清。本项目研究证实BDV感染细胞后细胞的糖酵解，乳酸合成水平，ATP合成水平均升高，而对感染细胞进行PFK1-211突变后其糖酵解，乳酸合成水平，ATP合成水平均下降。随着BDV感染时间的延长，BDV感染细胞的凋亡水平下降，其凋亡水平最高阶段为7-14天，之后凋亡水平逐渐下降。BDV可能通过调节Akt信号通路（BAD-S134, Caspase9-S196 和FOXO3A-S253 磷酸化）的水平抑制细胞的凋亡水平。本研究首次从Akt信号通路及能量代谢通路两方面为BDV长期与宿主细胞共存提供理论基础。