MIF/HIF-1α互为影响调控微血管周细胞分化对兔系统性硬化症肺动脉高压的作用研究

MIF/HIF-1α reciprocally affects the regulation of microvascular pericyte differentiation in pulmonary hypertension in rabbit systemic sclerosis

摘要:

目的 探讨巨噬细胞移动抑制因子/缺氧诱导因子1α（MIF/HIF-1α）互为影响调控微血管周细胞向肌成纤维细胞分化在兔系统性硬化症肺动脉高压中的病理作用。方法 40只雄性家兔按随机数字表法分为4组：对照组、模型组、MIF抑制剂组及HIF-1α抑制剂组，每组10只。MIF抑制剂组和HIF-1α抑制剂组分别使用异丙肌苷和2-甲氧基雌二醇腹腔注射。记录家兔右心室肥大指数（RVHI）及平均肺动脉压（mPAP）。酶联免疫吸附试验（ELISA）检测各组家兔血清中HIF-1α、MIF含量；通过苏木精-伊红（HE）染色观察家兔皮肤和肺组织切片病理改变，免疫组织化学染色观察各组肺组织中MIF、HIF-1α的表达；Western blotting检测周细胞MIF、HIF-1α、α-SMA、Col1A1的表达。结果 与对照组比较，模型组、MIF抑制剂组及HIF-1α抑制剂组mPAP和RVHI均升高（P <0.05）；与模型组比较，MIF抑制剂组和HIF-1α抑制剂组兔mPAP和RVHI均降低（P <0.05）。与对照组比较，模型组、MIF抑制剂组及HIF-1α抑制剂组MIF、HIF-1α含量均上升（P <0.05）；与模型组比较，MIF抑制剂组和HIF-1α抑制剂组MIF、HIF-1αF含量均下降（P <0.05）。HIF-1α与MIF呈正相关（r =0.853，P =0.026）。HE染色结果显示，模型组表皮层增厚，毛囊过度角化，真皮纤维组织增生，血管壁增厚，皮肤附属器减少；HIF-1α抑制剂和MIF抑制剂组皮肤表皮、真皮层及血管壁较对照组增厚，皮肤附属器减少；模型组肺组织可见肺小动脉管壁增生，管腔狭窄，HIF-1α抑制剂和MIF抑制剂可见肺小动脉管壁增生，部分管腔狭窄。免疫组织化学染色结果显示，与对照组比较，MIF抑制剂组及HIF-1α抑制剂组MIF和HIF-1α表达均升高（P <0.05）；与模型组比较，MIF抑制剂组及HIF-1α抑制剂组的MIF和HIF-1α表达均降低（P <0.05）。模型组兔肺组织中肺动脉壁内皮细胞的细胞浆及细胞核中MIF和HIF-1α均呈高表达。Western blotting结果显示，与对照组相比，模型组和HIF-1α抑制剂组的周细胞α-SMA和Col1A表达均升高（P <0.05）；与模型组相比，HIF-1α抑制剂组的周细胞α-SMA和Col1A表达均降低（P <0.05）。结论 MIF与HIF-1α可能互为影响并通过促进微血管周细胞向成纤维细胞分化参与系统性硬化肺动脉高压的病理过程。

Abstract:

Objective To investigate the pathological role of MIF/HIF-1α reciprocal effects in regulating the differentiation of pericytes to myofibroblasts in SSc-PAH.Methods Forty male rabbits were divided into four groups (n =10) by random number method: control group, model group, MIF inhibitor group and HIF-1α inhibitor group. the MIF inhibitor group and HIF-1α group were injected intraperitoneally using ISO and 2-ME2. The right ventricular hypertrophy index (RVHI) and mean pulmonary artery pressure (mPAP) were recorded in rabbits. ELISA was performed to detect the levels of HIF-1α and MIF in the serum of rabbits in each group; the pathological changes of rabbit skin and lung tissue sections were observed by HE staining, and the expression of MIF and HIF-1α in lung tissues of each group was observed by IHC staining; the expression of MIF and HIF-1α in pericytes was detected by Western blot. The expression changes of MIF, HIF-1α, α-SMA and Col1A1 were detected by Western blot in pericytes.Results Compared with the control group, the RVHI and mPAP of rabbits in the MIF inhibitor group and the HIF-1α inhibitor group were increased; compared with the model group, the RVHI and mPAP of rabbits in the MIF inhibitor group and the HIF-1α inhibitor group were decreased; compared with the control group, the serum levels of HIF-1α and MIF were increased in rabbits; compared with the model group, the expression of MIF and HIF-1α decreased in the MIF inhibitor group and HIF-1α inhibitor group; there was a positive correlation between HIF-1α and MIF (r = 0.853, P = 0.026); compared with the control group, the thickening of skin and blood vessel wall in rabbits in the MIF/HIF-1α inhibitor group was less than that in the model group, which had thickened skin dermis, fewer subcutaneous appendages, and significantly increased lung tissue lumen narrowing, irregular small pulmonary artery walls and interstitial lung mass; compared with the control group, the expression of both MIF and HIF-1α was increased in the inhibitor group, and compared with the model group, the expression of MIF and HIF-1α expression was decreased in the inhibitor group compared with the model group; HIF-1α was highly expressed in the lung tissue of rabbits in the model group. The expression of pericyte α-SMA and Col1A was elevated in the MIF/HIF-1α inhibitor group compared with the control group (P < 0.05); the expression of pericyte α-SMA and Col1A was decreased in the MIF/HIF-1α inhibitor group compared with the model group (P < 0.05).Conclusions MIF and HIF-1α may interact and participate in the pathological process of systemic sclerosis pulmonary hypertension by promoting the differentiation of microvascular pericytes to fibroblasts.