二氧化硅刺激肺成纤维细胞间隙连接功能下调的研究

目的　探索矽肺发病过程中二氧化硅(SiO

Study on silicon dioxide induced-downregulation of gap junct ional intercellular communication of the pulmonary fibroblasts

Objective　To explore the relationships betw een pulmonary fibrosis and downregulation of gap junctional intercellular comm unication(GJIC) of the fibroblasts after stimulation by SiO2. Metho ds　The pulmonary alveolar macrophage(PAM) and the phorbol 12-myrist ate 13-acetate(PMA or TPA) primed THP-1(pTHP-1),a monocyte-like cell line wi th the properties of PAM,were incubated in the serum-free RPMI?1640 containing SiO2 at various concentrations.The proliferation of Chinese hamster lung(CHL) fibroblast induced by cultured PAM or pTHP supernatant was detected by using MT T assay(to show as the a bsorbency,A570 nm),and GJIC between those cells was measured by using the fluorescence redis tribution after photobleaching(FRAP) assay(to show as the transfer rate of the f luorescence,K×10-3/s) performed with a laser scanning confocal micr oscope(LSCM,Carl Zeiss LSM 510,release 2.01). Results　Bot h SiO2 exposed PAM and pTHP-1 supern atants could induce the proliferation(PAM:F=3.205,P<0.05;pTHP-1:F=1 3.779,P<0.01) and the downregulation of GJIC(PAM:F=19.948,P<0. 01;pTHP-1:F=9.365,P<0.01) of the CHL cells.In the range of 0,50,1 00,200 and 500 μg/ml SiO2 concentrations,the proliferation(A570 nm values) and GJIC(the transfer rate,K)were fitted well in the dose-effect re lationship(PAM:r=-0.803,P<0.05;pTHP-1：r=-0.914,P<0.01). Compared with the blank control,both PAM and pTHP-1 supernatants could upregu late GJIC(K:21.24×10-3/s,18.92×10-3/s vs. 7.81×10 -3/s,7.81×10-3/s respectively,P<0.05) and inh ibit the proliferation of CHL cell(A570 nm:0.506,0.218 vs. 0.5 39,0.388 respectively,P<0.05). Conclusion　T hrough the way of stimulating PAM,SiO2 could inhibit GJIC of fibroblasts,and induce fibroblast proliferation.In the pathoge nesis of silicotic fibrosis,the downregulation of GJIC of the pulmonary fibrobla sts may play an important role.