加味麻杏石甘汤对放射性肺损伤TGF-β/Smad信号通路调控的研究

摘要

[目的]研究加味麻杏石甘汤对TGF-β/Smad信号通路的调控，阐述其抗放射性肺损伤的机制。[方法](1)清洁级SD大鼠分为中药组和正常对照组，中药组加味麻杏石甘汤灌胃3d后制备含药血清，正常对照组生理盐水灌胃制备大鼠血清；(2)小鼠肺泡Ⅱ型细胞培养，射线照射（频率为3.64Gy/min，总剂量为8Gy）造模，含药血清干预；(3)RNA干扰特异性沉默TGF-β1基因后，PCR检测TGF-β1、PAI-1、CTGFmRNA，Western-blot检测Smad蛋白水平，并行统计学比较。[结果](1)与大鼠血清组比较，10%含药血清组TGF-β1 mRNA、P-Smad2表达下调（P<0.05）；(2)沉默TGF-β1基因后，TGF-β1 mRNA表达及其下游靶基因PAI-1mRNA、CTGF mRNA均出现一致性低表达（P<0.05)，均明显低于未沉默TGF-β1基因的大鼠血清组（P<0.05）；(3)10%含药血清+siRNA组与大鼠血清+siRNA组比较，不论是P-Smad2、P-Smad3，还是下游靶基因PAI-1mRNA、CTGF mRNA表达差异未见统计学意义（P>0.05）；(4)10%含药血清+siRNA组Smad6、Smad7蛋白表达较大鼠血清+siRNA组均上升，差异有统计学意义（P<0.05，P<0.01）。[结论]加味麻杏石甘汤抵抗放射性肺损伤机制可能与干预TGF-β/Smad信号通路有关。%Objective] To prove the modified Maxingshigan Decoction(modified MXSGD) intervening radiation induced lung injury(RILI) through the TGF-β/Smad signaling pathway by selectively silencing the TGF-β1 gene. [Methods] (1)Total of 18 clean SD rats were randomly divided into two groups:Chinese medicine group treated with modified MXSGD and normal control group treated with saline. The serum was made after 3 days of taking drugs to prepare medicated serum. (2) The alveolar typeⅡcells were cultured. The total dose of radiation to cell was 8Gy, frequency 3.64Gy/min. The medicated serum was given to each group respectively. (3) After silencing TGF-β1 gene with RNA interference technology, the level of TGF-β1, PAI-1, CTGFmRNA was analyzed by PCR and the protein expression of Smads was measured by Western-blot. [Results] (1) Compared with rat serum group, the expressions of TGF-β1 mRNA, P-Smad2 in 10%medicated serum group were down-regulation or deceased(P<0.05).(2) Compared with rat serum group, the transcription levels of TGF-β1, and PAI-1 and CTGF were obviously suppressed after silencing TGF-β gene(P<0.05). (3) There was no significance effect on the expression of P-Smad2, P-Smad3, PAI-1mRNA and CTGF mRNA in both 10%medicated serum+siRNA group and rat serum+siRNA group(P>0.05). (4) Compared with rat serum+siRNA, the expression of Smad6 and Smad7 was increased in 10%medicated serum+siRNA group. The differences between the two groups were significant(P<0.05, P<0.01). [Conclusion] Modified MXSGD may intervene the RILI by regulating TGF-β/Smad signaling pathway.