他克莫司通过下调NFATc2抑制大鼠球囊损伤后颈总动脉内膜增生

Tacrolimus suppressed intimal hyperplasia of carotid artery induced by balloon injury in rats through reducing NFATc2 expression

目的观察他克莫司对大鼠球囊损伤后血管壁内膜增生的干预作用并探讨其机制。方法将27只健康雄性SD大鼠随机分成假手术组、球囊损伤模型组及他克莫司组(n=9),除假手术组外,其余大鼠建立颈总动脉球囊损伤模型。他克莫司组大鼠灌胃给予他克莫司(1 mg·kg^(-1)),假手术组和球囊损伤模型组大鼠灌胃给予相同体积的双蒸水,每日1次,连续给药14 d。最后一次给药后24 h,取损伤侧血管行HE染色,计算管腔面积、血管内膜面积(NIA)及内膜面积/中膜面积(NIA/MA);real-time PCR法检测肿瘤坏死因子(TNF)-α和白细胞介素(IL)^(-1)βm RNA表达,免疫组化法检测增殖细胞核抗原(PCNA)、活化T细胞核因子(NFAT)c2蛋白在血管壁中的表达。结果与假手术组相比,球囊损伤模型组管腔面积明显减小,NIA、NIA/MA增加,TNF-α和IL^(-1)βm RNA表达增高,PCNA、NFATc2蛋白表达增高(P<0.01)。与球囊损伤模型组相比,他克莫司组管腔面积增加,NIA增厚程度减轻,NIA/MA减小,TNF-α和IL^(-1)βm RNA的表达降低,PCNA、NFATc2蛋白的表达降低(P<0.05或P<0.01)。结论他克莫司可明显抑制血管内膜过度增生,其机制可能与其下调血管壁NFATc2蛋白和TNF-α、IL^(-1)βm RNA表达有关。

AIM To observe the effects of tacrolimus on the intimal hyperplasia of carotid artery induced by balloon injury in rats and to explore its mechanisms. METHODS Twenty-seven healthy male SD rats were randomly divided into 3 groups： sham group, balloon injury model group and tacrolimus group （n = 9）. Except the sham group, the balloon injury model were established in other rats. Tacrolimus （1 mg·kg^-1） was administered by gavage once a day for 14 days in the tacrolimus group. The same volume distilled water was administered in the sham group and model group for 14 days. Twenty- four hour after the last dose, the neointimal hyperplasia level was observed in the injured side of the vessel with HE staining. The lumen area, neointimal area （NIA） and NIA/medial area （MA） were calculated. The mRNA expression of TNF-α and IL- 1β in vascular wall was examined by real-time PCR. The protein expression of proliferating cell nuclear antigen （PCNA） and nuclear factor of activated T-cells （NFAT）c2 in vascular wall were examined by immunohisto- chemistry method. RESULTS Compared with the sham group, the lumen area was reduced, and the NIA and NIA/MA were increased, and the mRNA level of TNF-α, IL- 1 β, and the positive expression rate of PCNA and NFATc2 protein were increased in the balloon injury model group （P 〈 0.01）. Compared with the balloon injury model group, the NIA and NIA/MA were remarkably alleviated, and the mRNA levels of TNF-α and IL- 1β, and the positive expression of PCNA and NFATc2 protein were significantly lowered in the tacrolimus group （P 〈 0.05 or P 〈 0.01） . CONCLUSION Tacrolimus can attenuate the intimal hyperplasia of carotid artery induced by balloon injury in rats, which may be related to a down-regulation of the protein expression of NFATc2 and the mRNA level of TNF-α and IL-1β in the vascular wall.