虎杖苷调节Shh/Ptch1通路对精神分裂症大鼠神经元损伤及认知障碍的影响

Effect of polydatin on neuronal damage and cognitive impairment in rats with schizophrenia by regulating Shh/Ptch1 pathway

关键词:  虎杖苷  超音速刺猬因子  碎片蛋白1  精神分裂症  神经元损伤  认知障碍

Key words:  polydatin  sonic hedgehog  patched 1  schizophrenia  neuronal damage  cognitive impairment

摘要:

[目的] 探讨虎杖苷（PD）调节超音速刺猬因子（Shh）/碎片蛋白1（Ptch1）通路对精神分裂症（SZ）大鼠神经元损伤及认知障碍的影响。[方法] 采用地卓西平马来酸盐（MK-801）构建SZ模型大鼠。将建模成功的大鼠分为SZ组，PD低剂量组、PD高剂量组（分别腹腔注射50、100 mg/kg的PD），PD+环巴胺（Cyclopamine）组（腹腔注射100 mg/kg的PD+10 mg/kg Cyclopamine）。每组12只，另选择12只大鼠为对照组，对照组和SZ组灌胃和腹腔注射等量生理盐水，每日1次，连续给药14 d。检测各组大鼠刻板行为评分；Morris迷宫评价大鼠认知功能；酶联免疫吸附测定（ELISA）试剂盒检测血清中超氧化物歧化酶（SOD）、丙二醛（MDA）和海马组织中乙酰胆碱酯酶（AchE）、乙酰胆碱转移酶（ChAT）、乙酰胆碱（Ach）的水平；苏木精-伊红（HE）染色检测海马组织病理形态；末端标记法（TUNEL）染色检测海马组织神经元凋亡；蛋白免疫印迹（Western blot）检测海马组织中Shh、Ptch1蛋白的表达。[结果] 与SZ组相比，PD各给药组能依次下调刻板行为评分，减轻海马组织损伤和神经元凋亡（P < 0.05），降低血清中MDA、AchE的表达（P < 0.05），上调逃避潜伏期、跨越平台次数（P < 0.05），升高血清中SOD、ChAT、Ach的表达（P < 0.05）。与SZ组相比PD各给药组能显著增加Shh、Ptch1蛋白表达量（P < 0.05）。而PD+Cyclopamine组则逆转上述PD高剂量组的变化（P < 0.05）。[结论] PD改善SZ大鼠的神经元损伤和认知障碍与激活Shh/Ptch1通路有关。

Abstract:

[Objective]To explore the effects of polydatin(PD)on neuronal damage and cognitive impairment in rats with schizophrenia (SZ)by regulating the sonic hedgehog(Shh)/Patched 1(Ptch1)pathway.[Methods]Dizocilpine Maleate(MK - 801)was used to construct SZ model rats. The rats that were successfully modeled were assigned into SZ group, L-PD group, H-PD group(intraperitoneal injection of 50 and 100 mg/kg of PD respectively), and PD+cyclopamine group(intraperitoneal injection of 100 mg/kg of PD+10 mg/kg of Cyclopamine), with 12 per group. Another 12 rats were served as the NC group. The control(NC)group and the SZ group were injected with the same amount of saline through the stomach and peritoneal cavity, once a day, and continuously administered for 14 days. The stereotypical behavior scores of rats in each group were detected. Morris maze was used to evaluate cognitive function in rats. The enzyme-linked immunosorbent assay(ELISA)kit was used to detect the levels of superoxide dismutase(SOD), malondialdehyde (MDA)in serum, and acetylcholinesterase(AchE), acetylcholinesterase transferase(ChAT), and acetylcholine(Ach)in hippocampal tissue. Hematoxylin-eosin(HE)staining was used to detect the pathological morphology of hippocampal tissue. Terminal deoxynucleotidyl transferase - mediated dUTP nick - end labeling(TUNEL)staining was used to detect neuronal apoptosis in hippocampal tissue. Moreover, Western blot was performed to measure the expression of Shh and Ptch1 proteins in hippocampal tissue.[Results]Compared with the SZ group, each PD administration group could successively reduce the score of stereotyped behavior, alleviate the damage of hippocampal tissue and neuronal apoptosis(P < 0.05), decrease the expression of MDA and AchE in serum(P < 0.05), increase the escape latency and the number of crossing platforms(P < 0.05), and increase the expression of SOD, ChAT and Ach in serum(P < 0.05). Compared with the SZ group, the PD treatment groups significantly increased the protein expression levels of Shh and Ptch1(P < 0.05). However, the PD + Cyclopamine group reversed the changes observed in the high - dose PD group(P < 0.05).[Conclusion]The improvement of neuronal damage and cognitive impairment in SZ rats by PD is related to the activation of the Shh/Ptch1 pathway.