放射性肺损伤早期肺组织重建机制的探讨

目的 探讨Ⅳ型胶原和MMP-9在放射性肺损伤早期肺组织重建中的作用。方法 用噻唑蓝(MTT)检测1～10 Gy ⁶⁰Co γ 射线照射对人肺成纤维细胞(Fb)增殖的影响;用酶联免疫吸附法测定经5和7 Gy照射后Fb中Ⅳ型胶原和MMP-9的变化;从经25 Gy照射后大鼠肺泡灌洗液中分离巨噬细胞,制备条件培养液(CMAM)并刺激肺Fb,用MTT检测对细胞增殖的影响;同时用ELISA测定对Fb合成Ⅳ型胶原和MMP-9的影响;于照射后不同时间取大鼠肺组织进行Ⅳ型胶原和MMP-9免疫组化染色。结果 1～7 Gy照射能促进肺Fb增生;5和7 Gy照射能促进Fb合成MMP-9,但不能促进Ⅳ型胶原合成;CMAM不但能促进Fb增生和MMP-9合成,也能合成和释放Ⅳ型胶原;受照后1周大鼠肺组织出现Ⅳ型胶原沉积。结论 照射能直接刺激肺Fb增生,但不能产生Ⅳ型胶原;Ⅳ型胶原的合成与照射后肺内巨噬细胞和Fb的相互作用有关,并可导致肺损伤重建的发生。

Exploration on remodeling of lung tissue in early radiation pulmonary injury

Objective To investigate the roles of collagen type Ⅳ and Matrix metallopreteinage-9(MMP-9)on remodeling of lung tissue in early radiation pulmonary injury.Methods The proliferation of human lung fibroblast(Fb)was determined by MTT following irradiation with 60Co γ ray of 1-10 Gy;the alteration of collagen type Ⅳ and MMP-9 was meagured by ELISA following Fb was irradiated with 5 and 7 Gy;Macrophage wag isolated from alveolar lavage solution of rat irradiated by 25 Gy of γ ray,and condition medium of alveolar maerophage(CMAM)was prepared for stimulation of pulmonary Fb,and the cellular proliferation was determined by MTT,the synthesis of collagen type Ⅳ and MMP-9 was measured by ELISA.Immunohistochemical staining of collagen type Ⅳ and MMP-9 was performed with rat lung tissue at different times after irradiation.Results Irradiation with 1-7 Gy on pulmonary Fb could promote cellular proliferation and MMP-9 synthesis,but could not promote the collagen type Ⅳ synthesis.However,the CMAM could not only promote Fb proliferation and MMP-9 synthesis.but also promote collagen type Ⅳ synthesis and releage.The deposition of collagen type Ⅳ in lung tissue could be found one week after irradiation.Conclusions Radiation can promote pulmonary Fb proliferation but can't make it produce collagen type Ⅳ.The synthesis of collagen type Ⅳ is related to interaction between pulmonary macrophage and Fb after irradiation,and it is directly involved in pulmonary remodeling after radiation pulmonary injury.