2型糖尿病肺纤维化病理特征的实验研究

Experimental study on pathological features of pulmonary fibrosis in type 2 diabetes mellitus

目的探讨2型糖尿病患者肺纤维化的病理特征。方法选取2020年6月至2021年10月武汉大学人民医院胸外科肺部手术合并2型糖尿病患者27例作糖尿病组(DM组),另选同期肺部手术未合并2型糖尿病患者17例作对照组(Control组),收集完整病例信息及肺组织手术标本分析两组患者的肺纤维化特征,计数资料采用χ^(2)检验,计量资料采用t检验。结果DM组空腹血糖(FPG)高于Control组[(7.16±1.74)mmol/L比(4.88±0.51)mmol/L,t=5.006,P<0.01],其余指标差异均无统计学意义(P>0.05);肺功能示DM组第1秒用力呼气容积/用力肺活量(FEV1/FVC)高于Control组[(80.05±5.77)%比(74.23±3.93)%,t=3.092,P<0.05],用力肺活量占预计值的百分比(FVC%pred)、第1秒用力呼气容积占预计值的百分比(FEV1%pred)、最大通气量占预计值的百分比(MVV%pred)、一氧化碳弥散量(DLco)等低于Control组[(96.65±12.71)%比(108.85±10.35)%,(88.20±9.78)%比(99.08±8.03)%,(85.24±14.21)%比(97.11±10.42)%,(17.61±3.47)ml/(mmHg·min)比(20.74±3.70)ml/(mmHg·min),t=2.867、3.241、2.125、2.215,P<0.05,1 mmHg=0.133 kPa],且其肺功能指标改变与限制性通气功能障碍相符;病理染色结果示DM组较Control组有明显的肺泡间隔增厚、肺血管基底膜增厚、大量炎性细胞浸润及特征性纤维化改变,且DM组纤维化阳性率高于Control组[85.19%(23/27)比17.65%(3/17),χ^(2)=19.680,P<0.01];分子水平检测到DM组肺间质纤维化的蛋白标志物波形蛋白(Vimentin)、胶原蛋白1(Collagen1)和相关基因α-肌动蛋白(α-SMA)、Vimentin、Collagen1、胶原蛋白3(Collagen3)的mRNA表达水平明显高于Control组(t=12.520、6.304,P<0.01)和(t=6.017、32.710、13.740、8.110,P<0.01);免疫荧光染色结果示DM组肺组织纤维化标志物在肺血管周累积明显增加。结论2型糖尿病患者在长期高血糖刺激下可诱发肺纤维化,且纤维化标志物主要累积于肺血管周。

Objective To investigate the pathological features of pulmonary fibrosis in patients with type 2 diabetes mellitus(T2DM).Methods Totally,27 cases patients with T2DM 2 diabetes mellitus were selected as the DM group,and 17 patients without T2DM in the same period served as the control group(control group)at the Department of Thoracic Surgery,Renmin Hospital of Wuhan University from June 2020 to October 2021.Then the pathological features of pulmonary fibrosis in the two groups were analyzed after the complete cases information and lung surgical tissue were collected.Chi-square test was used for count data and t test was used for measurement data for statistical analysis.Results The fasting plasma glucose(FPG)in the DM group was higher than in the control group[(7.16±1.74)vs.(4.88±0.51)mmol/L,t=5.006,P<0.01],and there was no significant difference in the rest parameters.Pulmonary function showed that the forced expiratory volume in one second to the forced vital capacity(FEV1/FVC)in the DM group was higher than in the control group[(80.05±5.77)%vs.(74.23±3.93)%,t=3.092,P<0.05].The percentage of predicted value in the forced vital capacity(FVC%pred),percentage of predicted value in the forced expiratory volume in one second(FEV1%pred),percentage of predicted value in maximal ventilation volume(MVV%pred),and diffusing capacity for carbon monoxide(DLco)in the DM group were lower than in the control group[(96.65±12.71)%vs.(108.85±10.35)%,(88.20±9.78)%vs.(99.08±8.03)%,(85.24±14.21)%vs.(97.11±10.42)%,(17.61±3.47)ml/(mmHg·min)vs.(20.74±3.70)ml/(mmHg·min);t=2.867,3.241,2.125,2.215,P<0.05,1 mmHg=0.133 kPa],and the changes in lung function indexes were consistent with restrictive ventilatory dysfunction.The pathological staining showed that the DM group had obvious alveolar septum thickening,pulmonary vascular basement lamina thickening,a large number of inflammatory cell infiltration and characteristic fibrotic changes compared to the control group,and the positive rate of fibrosis in the DM group was significantly higher than in the control group[85.19%(23/27)vs.17.65%(3/17),χ^(2)=19.68,P<0.01].The protein markers of Vimentin,Collagen1,and the mRNA expression levels of alpha-smooth muscle actin(α-SMA),Vimentin,Collagen1,Collagen3 of pulmonary fibrosis in the DM group were significantly higher than in the control group(t=12.520,6.304,P<0.01;t=6.017,32.710,13.740,8.110,P<0.01).The immunofluorescence staining showed that the accumulation of pulmonary fibrosis markers in the DM group increased significantly around the pulmonary vessels.Conclusion Patients with T2DM can induce pulmonary fibrosis under long-term hyperglycemia stimulation,and fibrosis markers mainly accumulate around the pulmonary vessels.