硫辛酸通过激活PI3K/Akt通路保护帕金森小鼠神经元的作用研究

Mechanism of Lipoic Acid Protecting Neurons in Parkinson’s Mice on PI3K/Akt Pathway

目的:明确硫辛酸(lipoic acid,LA)是否通过活化脂酰肌醇3-激酶/蛋白激酶B(Phosphoinositide 3-kinases/Protein kinase B,PI3K/Akt)通路保护小鼠帕金森(Parkinson’s disease,PD)神经元损伤。方法:将130只健康C57BL雄性小鼠随机分为PD模型组(A组)、PD模型自然恢复组(B组)、硫辛酸干预组(C组)、硫辛酸加阻滞剂干预组(D组),对照组(E组)。采用免疫组化方法检测黑质内酪氨酸羟化酶(Tyrosine hydroxylase,TH)阳性细胞数,Western Blot方法检测中脑TH、总Akt和p-Akt蛋白表达,相应试剂盒检测中脑内GSH(Glutathione)和MDA(Malondialdehyde)的含量。结果:(1)与E组比较,A组TH阳性细胞数显著减少(P<0.01),B组、D组明显减少(P<0.05),C组无明显统计学意义(P>0.05)。(2)与E组比较,A组、B组TH蛋白表达显著减少(P<0.01),C组、D组TH表达明显减少(P<0.05);分别与A组、B组比较,C组TH表达显著增多(P<0.01),D组无明显统计学意义(P>0.05)。(3)与E组比较,A组、B组、D组中脑内p-AKT表达显著减少(P<0.01),C组差异无明显统计学意义(P>0.05);分别与A组、B组比较,C组pAkt表达显著增多(P<0.01),D差异无明显统计学意义(P>0.05)。(4)与E组比较,C组中脑GSH水平明显增加(P<0.05),A组、B组明显减少(P<0.05),D组差异无统计学意义(P>0.05;与E组比较,A组、B组MDA表达显著增加(P<0.01),C组、D组差异无统计学意义(P>0.05)。结论:硫辛酸可能通过激活PI3K/Akt通路,减轻氧化应激损伤,进而发挥其保护神经元的作用。

Objective: To determine whether lipoic acid(LA) could protect mouse Parkinson’s disease(PD) neuronal damage by activating the PI3K/Akt pathway. Methods:130 healthy C57BL male mice were randomly divided into 5 groups(n=20): PD model group(group A), PD model natural recovery group(group B), lipoic acid intervention group(group C), Lipoic acid with blocker intervention group(group D), control group(group E). Immunohistochemistry was used to detect the number of tyrosine hydroxylase(TH) positive cells in the substantia nigra;The expression of TH, Total Akt and p-Akt in the middle brain was detected by Western Blot. The corresponding kits were used to detect GSH and MDA in the midbrain. Results:(1)Compared with group E, the number of TH positive cells in group A was significantly decreased(P <0.01);Group B and Group D were significantly decreased(P <0.05);group C was not statistically significant(P>0.05).(2) Compared with group E, the expression of TH protein in group A and B was significantly decreased(P<0.01), and the expression of TH in group C and D was significantly decreased(P <0.05);Compare with group A and group B respectively, the expression of TH was significantly increased in group C(P<0.01), and group D was no significant(P>0.05).(3)Compared with group E,the expression of pAKT in brains of group A, group B and group D was significantly decreased(P<0.01), and there was no significant difference in group C(P>0.05);compared with group A and group B respectively. The expression of pAkt was significantly increased in group C(P<0.01), and there was no significant different in group D(P>0.05).(4) Compared with group E, the level of GSH in the middle brain was increased(P<0.05) in group C, and significantly decreased in group A and group B(P<0.05), group D was no significant difference(P>0.05);Compared with group E, the expression of MDA in group A and group B was significantly increased(P<0.01), there was no significant difference in group C and group D(P >0.05). Conclusions: Lipoic acid may play a role in protecting neurons by activating the PI3K/Akt pathway, reducing oxidative stress damage.