电刺激迷走神经对血管壁c-kit^(+)细胞迁移和分化的影响

Effects of electrical stimulation of vagus nerve on migration and differentiation of c-kit^(+)vascular wall cells

目的观察电刺激迷走神经对颈动脉损伤大鼠血管壁c-kit^(+)细胞迁移和分化的影响。方法将24只SD大鼠随机分为假手术组、模型组、迷走神经刺激组,每组8只。制备SD大鼠左颈总动脉球囊损伤模型后,迷走神经刺激组电刺激左侧迷走神经。通过HE染色及免疫组织化学染色分别观察血管内膜厚度和c-kit^(+)细胞在血管壁中的分布;酶联免疫吸附试验(ELISA)检测大鼠血清中肿瘤坏死因子(TNF)-α和白细胞介素(IL)-6水平。原代培养血管壁c-kit^(+)细胞,分为对照组(不加入乙酰胆碱)、1×10^(-5) mol/L乙酰胆碱组、1×10^(-8) mol/L乙酰胆碱组及1×10^(-5) mol/L乙酰胆碱+α7烟碱样乙酰胆碱受体(α7nAChR)拮抗剂组。Transwell检测细胞迁移能力变化,Western blot检测平滑肌22α(SM22α)蛋白表达。结果(1)与模型组比较,迷走神经刺激组新生内膜厚度变薄,新生内膜中c-kit^(+)细胞数量减少(P<0.05),血清TNF-α和IL-6水平也下降(P<0.01)。(2)乙酰胆碱抑制c-kit^(+)细胞迁移,上调SM22α的表达,α7nAChR拮抗剂可逆转上述效应。结论迷走神经通过抑制c-kit^(+)细胞迁移并促进其向平滑肌细胞分化而抑制新生内膜形成,其作用机制可能与神经末梢释放的递质乙酰胆碱结合α7nAChR,进而激活抗炎系统有关。

Objective To investigate the effect of electrical stimulation of vagus nerve on migration and differentiation of c-kit^(+)vascular wall cells in rats under carotid artery injury.Methods A total of 24 SD rats were randomly divided into three groups:the sham-operation group,the operation group and the vagus nerve stimulation group,with 8 rats in each group.After the common carotid artery balloon injury model was carried out,the left vagus nerve was electrically stimulated in the vagus nerve stimulation group.HE staining and immunohistochemical staining were used to observe the thickness of vascular intima and the distribution of c-kit^(+)vascular wall cells.The serum levels of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)were measured by enzyme-linked immunosorbent assay(ELISA).After isolating c-kit^(+)cells from the vessel wall,the c-kit^(+)cells were divided into three groups:the control group(no acetylcholine),the 10^(-5) mol/L acetylcholine group and the 10^(-5) mol/L acetylcholine group with the+alpha 7 nicotinic acetylcholine receptor(α7nAChR)agonist group.Transwell assay was applied to detect the effect of acetylcholine on c-kit^(+)migration,and the expression of smooth muscle 22 alpha(SM22α)was detected by Western blot assay.Results(1)Compared with operation group,the thickness of vascular neointima was reduced,and the number of c-kit^(+)cells in vascular neointima was decreased in the vagus nerve stimulation group(P<0.05),and the serum levels of TNF-αand IL-6 were also reduced(P<0.01).(2)Acetylcholine inhibited the ckit^(+)migration and increased the expression of SM22α,which could be reversed byα7nAChR agonist.Conclusion Acetylcholine can mitigate the neointimal formation through inhibiting the migration of c-kit^(+)and accelerating the differentiation of c-kit^(+)to vascular smooth muscle cells,the mechanism of which may be related to acetylcholine combined withα7nAChR that activating anti-inflammatory system.