Objective: To investigate the molecular protective mechanisms of Huangqi decoction inhibiting the apoptosis of renal cells in the 12C6+ radiation brain model rats. Methods: Fifty Wistar rats were randomly divided into five groups: normal control group, radiation alone model group, Huangqi decoction (high-dose, middle-dose and low-dose ) groups. The normal control group and the radiation alone group were treated with saline10 ml/(kg·d) by gavage, the Huangqi decoction treatment groups were treated with Huangqi decoction at the doses of 4.5, 9 and 18 g/(kg·d) by gavage respectively. After 7 d, except mice in normal control group, the brain of the rats in radiation alone model group, high-dose, middle-dose and low-dose Huangqi decoction group were radiated by 4 Gy 12C6+ ion once. The rats were killed by the femoral artery after irradiation 7 d. The pathomorphism changes of renal tissue were observed by HE, the IL-6 level in serum was detected by ELISA, the gene expressions of Bcl-2, Bax and caspase-3 in renal tissue were assessed by RT-PCR, and the protein expressions of Bcl-2, Bax, caspase-3 and NF-κB in renal tissue were analyzed by immunehistochemical staining. Results: Compared with normal control group, the body weight and kidney index were decreased significantly, the expression of Bcl-2 in renal tissue was decreased significantly, the serum content of IL-6 was increased obviously, and the expressions of Bax, caspase-3 and NF-κB in renal tissue were increased significantly in the radiation alone model group (P＜0.01). The mesangial cells proliferated obviously, interstitial vessels of renal tubules were dilated and congested obviously, the lumen of renal tubules was narrow and irregular in the radiation alone model group. As compared with the radiation alone model group, the body weight and the kidney index were increased obviously in high-dose Huangqi decoction group, the gene and protein expressions of Bcl-2 in renal tissue were increased significantly in Huangqi decoction intervention group(P＜0.05 or P＜0.01). whereas, the protein expressions of Bax and caspase-3 in renal tissue were decreased significantly in middle-dose and high-dose Huangqi decoction group, the serum content of IL-6 was decreased obviously, the gene expressions of Bax and caspase-3 in renal tissue were decreased significantly and the protein expression of NF-κB in renal tissue was decreased significantly in Huangqi decoction intervention group(P＜0.05 or P＜0.01). The proliferation of mesangial cells was improved and the contour of renal tubules was clear in high-dose huangqi decoction group. Conclusion: High-dose of huangqi decoction has protective effect on kidney in rats induced by 12C6+ radiation brain, the mechanism may be related to the regulation of Bcl-2/NF-κB signal pathway.
目的: 探讨黄芪汤抑制12C6+离子辐射脑模型鼠肾组织细胞凋亡的分子保护机制。方法: 50只SPF级Wistar大鼠随机分为正常对照组,单纯辐射模型组,黄芪汤(高、中、低剂量)组。正常对照组和单纯辐射模型组给予等体积生理盐水灌胃10 ml/(kg·d),黄芪汤治疗组分别灌胃给予黄芪汤18、9、4.5 g/(kg·d),连续给药2周。7 d后除正常对照组外,其余各组大鼠脑组织给予4Gy 12C6+离子束单次照射,辐射后第7日处死各组大鼠。HE染色法观察大鼠肾脏的病理形态变化,ELISA法检测大鼠血清IL-6的含量,实时荧光定量PCR法测定大鼠肾脏Bcl-2、Bax和Caspase-3的基因表达,免疫组化法检测大鼠肾脏Bcl-2、Bax、Caspase-3和NF-κB的蛋白表达。结果: 与正常对照组比较,单纯辐射模型组体重和肾脏指数均显著降低,血清IL-6的含量显著升高,肾脏Bcl-2的基因表达和蛋白表达均显著降低,Bax和Caspase-3的基因表达和蛋白表达均显著升高,NF-κB的蛋白表达也显著升高(P＜ 0.01),单纯辐射组肾小球系膜细胞明显增生,肾小管间质血管明显扩张充血,肾小管管腔狭窄、不规则。与单纯辐射模型组相比,黄芪汤高剂量组体重和肾脏指数均明显升高,黄芪汤各干预组肾脏Bcl-2的基因表达和蛋白表达均显著升高(P＜0.05或P＜0.01);而黄芪汤中、高剂量组Bax和Caspase-3的蛋白表达均显著降低,各干预组血清IL-6的含量显著降低,肾脏Bax和Caspase-3的基因表达均显著降低,肾脏NF-κB的蛋白表达显著下降(P＜0.05或P＜0.01),黄芪汤高剂量组可见肾小球系膜细胞增生情况明显改善,肾小管轮廓清晰。结论: 黄芪汤对12C6+离子辐射脑模型鼠的肾损伤具有一定的防护作用,其作用机制可能与调控Bcl-2/NF-κB信号通路有关。.
Keywords: Bcl-2/NF-κB signal pathway; heavy ion radiation; kidney apoptosis; rat; huangqi decoction.