枸杞多糖对颅内动脉瘤大鼠NF-κB信号通路及血管内皮组织炎性损伤的影响

The effects of lycium barbarum polysaccharide on NF-κB signal pathway and inflammatory injury of vascular endothelial tissue in rats with intracranial aneurysm

目的探讨枸杞多糖(LBP)对颅内动脉瘤(IA)大鼠核蛋白因子-κB(NF-κB)蛋白通路及血管内皮组织炎性损伤的影响。方法取SD雌性大鼠50只,采用切除双侧卵巢并结扎左侧颈总动脉及双侧肾动脉后支以构建IA模型,随机分为IA模型组、LBP低(5 mg/kg)、中(10 mg/kg)、高(20 mg/kg)剂量组,另取10只大鼠,只暴露卵巢、颈总动脉、双侧肾动脉后支,不进行摘除和结扎,作为对照组(Control组);各组均于手术1周后,开始给药,Control组、IA模型组经灌胃给予生理盐水,LBP各剂量组灌胃给予相应剂量药物,1次/d,共给药30 d;末次给药12 h后处死,取大鼠血液用酶联免疫吸附法(ELISA)检测血清炎性因子白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)及血管内皮损伤标志物血管内皮生长因子(VEGF)、血管内皮素(ET)水平;分离取出大鼠脑动脉(Wills)环,在40倍显微镜下检查大脑动脉(Wills)环病理改变,并检测动脉瘤血管壁厚度及动脉瘤体积;取脑动脉瘤血管组织,用苏木精-伊红染色(HE)检测动脉瘤血管组织病理变化;蛋白免疫印迹法(Western blot)检测动脉瘤血管组织NF-κB,Toll样受体-4(TLR4)蛋白表达水平。结果与Control组比较,IA模型组大鼠Willis环上凸起、管壁厚度和肿动脉瘤体积、动脉瘤内皮细胞空泡变性及炎性细胞浸润等病理损伤程度、血清IL-6,TNF-α,VEGF,ET水平、动脉瘤血管组织NF-κB和TLR4蛋白表达水平明显升高(P<0.05);与IA模型组比较,LBP低、中、高剂量组大鼠Willis环上凸起、管壁厚度和动脉瘤体积、动脉瘤内皮细胞空泡变性及炎性细胞浸润等病理损伤程度、血清IL-6,TNF-α,VEGF,ET水平、动脉瘤血管组织NF-κB和TLR4蛋白表达水平明显降低(P<0.05),且LBP各剂量组上述指标水平呈剂量依赖性降低。结论 LBP可能通过抑制TLR4/NF-κB通路激活、降低炎症反应来减轻IA血管内皮组织损伤。

Objective To investigate the effects of lycium barbarum polysaccharide(LBP) on nuclear factor kappa B(NF-κB) protein pathway and inflammatory injury of vascular endothelial tissue in rats with intracranial aneurysm(IA).Methods A total of 50 female SD rats were used to construct IA model by ovariectomy and ligation of left common carotid artery and posterior branches of bilateral renal artery, and they were randomly divided into IA model group, low(5 mg/kg), medium(10 mg/kg), high(20 mg/kg) dose LBP groups, and another 10 rats were exposed to ovaries, common carotid arteries and posterior branches of bilateral renal arteries, without removal and ligation, as control group. Each group was given medicine after one week of operation, control group and IA model group were given normal saline by gavage, and LBP groups were given corresponding doses of medicine by gavage, once a day, for a total of 30 days. After 12 hours of the last administration, the rats were killed, the levels of serum inflammatory factors of interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) and the levels of vascular endothelial injury markers of endothelin(ET) and endothelin(ET) in the rats were measured by enzyme-linked immunosorbent assay(ELISA), the rings of the cerebral arteries were separated, the pathological changes of the rings of the cerebral arteries(Willis) were examined under 40 times microscope, and the thickness of artery wall and the volume of aneurysm were measured, the vascular tissues of cerebral aneurysm were taken, hematoxylin eosin staining(HE) was used to detect the pathological changes of cerebral aneurysm, and the protein expression levels of NF-κB and toll like receptor-4(TLR4) were detected by Western blot.Results Compared with those in the control group, the degree of pathological damage, such as protuberance on Willis ring, thickness of vessel wall and tumor volume, vacuolar degeneration of aneurysm endothelial cells and inflammatory cell infiltration, the levels of serum IL-6, TNF-α, VEGF and ET, the protein expression levels of NF-κB and TLR4 in aneurysm of rats in the IA group were significantly higher(P<0.05), compared with those in the IA group, the degree of pathological damage, such as protuberance on Willis ring, thickness of vessel wall and tumor volume, vacuolar degeneration of aneurysm endothelial cells and inflammatory cell infiltration, the levels of serum IL-6, TNF-α, VEGF and ET, the protein expression levels of NF-κB and TLR4 in aneurysm of rats in the LBP low, middle and high dose groups were significantly lower(P<0.05), and the above parameters of LBP groups decreased in a dose-dependent manner.Conclusion LBP might inhibit the activation of TLR4/NF-κB pathway, reduce the inflammatory response and alleviate the injury of IA vascular endothelial tissue.