龙血竭对肺纤维化大鼠肺组织TGF-β/Smads信号通路分子mRNA表达的影响

目的 观察龙血竭对肺纤维化大鼠肺组织 TGF-β信号通路分子TGFβRⅡ及Smad4 mRNA表达的影响,探讨其防治肺纤维化的作用及机制. 方法将30只SD大鼠随机分为3组:肺纤维化模型组,龙血竭治疗组和正常对照组,每组10只,雌雄各半.模型组和治疗组大鼠均以博来霉素(5 mg/kg)气管内滴入诱导肺纤维化;对照组以等量生理盐水气管内滴入.从第2 d起,治疗组大鼠给予龙血竭(180 mg/kg,溶于2 mL生理盐水中)灌胃,对照组和模型组大鼠则以等量生理盐水灌胃.所有大鼠于第29 d早晨处死.HE染色检测肺组织病理改变;原位杂交检测肺组织TGFβRⅡ及Smad4 mRNA表达;免疫组化法(S-P法)检测Ⅰ型胶原纤维. 结果模型组肺组织内炎性细胞计数为22243.60±5011.55,治疗组为12913.78±5640.12,两组比较差异有统计学意义(P＜0.01).经龙血竭治疗后大鼠肺内TGFβRⅡ mRNA表达较模型组降低(P＜0.01).治疗组Smad4 mRNA表达与模型组比较差异无统计学意义.治疗组和模型组比较,Ⅰ型胶原纤维表达减弱(P＜0.01). 结论龙血竭能有效地减轻肺纤维化大鼠的纤维化程度,其机制可能与抑制肺内TGFβRⅡ mRNA的表达,从而阻止Ⅰ型胶原过度沉积有关.

Effect of Dragon's Blood on TGF-β/Smads Signal Transduction Molecule mRNA Expression in the Lung Tissue of Rats with Pulmonary Fibrosis

OBJECTIVE: To investigate the effect of Dragon's Blood on the expression of TGF-beta signal transduction molecule TGFbetaR II or Smad4 mRNA in the lung tissue of rats with pulmonary fibrosis, and to evaluate the effect and its mechanism of Dragon's Blood on pulmonary fibrosis. METHODS: 30 SD rats were randomly divided into three groups: fibrosis model, treatment and normal control groups. In model group and treatment group, the pulmonary fibrous tissues were induced to form with the intratracheal injection of bleomycin (5 mg/kg). In normal control group, saline was given intratracheally. Dragon's Blood was administered intragastricly in treatment group with a dose of 180 mg/kg diluted in 2 mL saline while saline was given intragastricly to other two groups with same volume from day 2 till day 28 after modeling. All rats were sacrificed on the 29th day. The rat lung histopathology was examined with HE staining. In situ hybridization was used to detect the expressions of TGFbetaR II and Smad4 mRNAs in lung tissue, and the expression of collagen fibril I was examined by an immunohistochemical staining. RESULTS: The inflammation cell counting in treatment group (12913.78 +/- 5640.12) was significant lower than that in model group (22243.60 +/- 5011.55, P < 0.01). The expression of pulmonary TGF/betaR II mRNA in treatment group was significant lower than that in model group (P < 0.01). In the Smad4 mRNA expression of lung tissue, there was no significant difference occurring between treatment group and model group (P > 0.05). The expression of collagen fibril I in the lung tissue of rats in treatment group was significant lower than that in model group (P < 0. 01). CONCLUSION: Dragon's Blood can effectively reduce rats' pulmonary fibrosis, of which the mechanisms may be to inhibit the expression of TGFbetaR II mRNA in the lung tissue and thus to have the preventive effect on the excessive deposit of collagen fibril I.