蝎毒抗帕金森病小鼠多巴胺能神经元凋亡

研究蝎毒对帕金森病 (PD)小鼠脑内多巴胺能神经元的抗凋亡作用及其机制。用C5 7BL/ 6 品系小鼠 ,每日于颈部皮下注入 1 甲基 4 苯基 1,2 ,3,6 四氢吡啶 (MPTP ,2 0mg/kg)复制帕金森病模型 ,随机分为模型组及蝎毒 (SV)提取液高 (2 0 0mg/kg)、低剂量 (2 0mg/kg)治疗组 ;另设对照组 (NS)和空白给SV高、低剂量组。各组均为 8只。采用爬杆、游泳行为学检测小鼠的运动功能障碍 ;应用DNA断裂点标记法 (TUNEL)检测黑质致密部 (SNc)多巴胺 (DA)能神经元的凋亡 ;利用免疫细胞化学法检测Bcl 2 /Bax基因的表达。结果表明 :SV能改善PD小鼠运动功能障碍 ;模型组SNc部可见大量TUNEL阳性细胞 (P <0 0 1) ,治疗组TUNEL阳性细胞数均明显减少 (P <0 0 1) ;模型组SNcBcl 2免疫反应活性 (IR)阳性神经元数明显减少 (P <0 0 1) ,Bax IR阳性神经元数明显增多 (P <0 0 1) ,治疗药组未见Bcl 2 IR阳性神经元数明显减少或Bax IR阳性神经元数明显增多。提示 :SV可能通过上调Bcl 2、下调Bax基因表达抑制DA能神经元凋亡。

Effect of scorpion venom on the expression of Bcl-2/Bax in dopaminergic neurons of PD mice

To study the anti-apoptosis effect and its mechanism of Scorpion Venom (SV) on dopaminergic neurons of PD Mice. C57BL/6 mice were injected with 1- methyl -4- phenyl -1, 2, 3, 6 tetrahydropyridine (MPTP, 20 mg/kg ) to make PD model, then were randomly designed into model group and treatment groups which were treated with higher dose ( 200 mg/kg ) and lower dose ( 20 mg/kg ) of SV respectively; other control groups were prepared with injection of normal saline (NS) or treatment of SV with higher and lower doses. Eight mice were caged in one group. Mice were examined behaviorally with Pole test and Swimming test consecutively for the dyskinesia; the dopaminergic(DAergic) neurons in substantia nigra compacta (SNc) were detected for apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling (TUNEL); the gene expression of Bcl-2 / Bax was investigated by immunocytochemistry (ICC). The results demonstrated that SV can improve dyskinesia for PD mice; More TUNEL-positive cells appeared in SNc of model group (P<0.01), while apparently less TUNEL-positive cells presented in SV treated groups (P<0.01); the number of Bcl-2 immunoreactivity (IR) positive neurons in SNc of model group was significantly decreased (P<0.01 ), but increased in the number of Bax-IR positive cells (P<0.01 ). Neither decreased Bcl-2-IR nor increased Bax-IR was observed in SV treated groups (P<0.05 for lower and P<0.01 for higher dose of SV). Results indicate that SV can prevent DAergic neurons from apoptosis by up-regulating the expression of Bcl-2 and down-regulating the Bax.