The Mechanism Of Pleural Fibrosis And The Research On Its Prevention And Treatment

Objective: 1. To explore the element of the collagen in pleural fibrosis; 2.To explore the function of fibronectin (FN), Iaminin (LN), collagen IV(Col IV), transforming growth factor beta₁ (TGF-beta₁), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and plasminogen activator inhibitor-1(PAI-1) of pleural effusions in pleural fibrosis; 3. To investigate the effects of fibroblasts(FB) and mesothelial cells(MC) from the rat pleura on the secretion of TGF-betai, VEGF, bFGF and PAI-1 and the influence of urokinase (UK) on TGF-betai, VEGF, bFGF and PAI-1; 4.To investigate the effects of urokinase on the proliferation and apoptosis of FB , demonstrate the mechanism of treating pleural fibrosis using UK. Methods: 1. To observe the collagen in human fibrotic pleura by polarization microscopy using the sections stained with Sirius red; 2.Levels of FN, LN, Col IV, TGF-betai, VEGF, bFGF and PAI-1 in exudates and transudates were measured by enzymelinked immunoserbent assay(ELISA). 3. Rat pleural FB and MC were isolated and cultured in vitro, the TGF-betai, VEGF, bFGF and PAI-1 contents in the cultured suspension media were measured by ELISA. After FB and MC were cultured with UK of different concentration (5000, 10000, 20000,30000IU/mL) for 24 h, the TGF-beta₁ ,VEGF, bFGF and PAI-1 contents in the cultured suspension media were measured by ELISA again.4. FB were cultured with UK of different concentration (5000,10000, 20000, 30000IU/mL). The effects of UK on the proliferation of the FB were observed by MTT assays. Light microscopy was used to observed morphological change. Apoptosis bodies were examined after fluorescent staining. Flow cytometry technique was used to detect apoptosis cells.Results: 1. Collagen in pleura consists of Col I and Col III mainly in the late phase of pleural fibrosis; 2. The levels of FN, LN and Col IV in tubercular exudates were markedly higher than those in transudates (P<0.05). 3. The levels of TGF-betai, VEGF and PAI-1 in tubercular exudates were markedly higher than those in transudates (P<0.05), but there were no statistically significant differences in bFGF level in tubercular exudates and transudates (P>0.05). 4.Level of TGF-betai, VEGF, bFGF and PAI-1 secreted by pleural FB were 3035.655 ± 394.975pg/mL; 22.09 ± 7.48ng/mL; 261.975 ± 25.55pg/mL; 1.8775 + 0.39 ng/mL respectively. Level of TGF-betai, VEGF, bFGF and PAI-1 secreted by pleural MC were 888.8 +165pg/mL; 19.12 + 2.84ng/mL; 241.925±23.82 pg/mL; 2.7325+ 0.33ng/mL respectively. UK of different concentration (5000, 10000, 20000, 30000IU/mL) could inhibit TGF-beta₁ VEGF, bFGF and PAI-1 secreting (PO.05). 5.Proliferation of FB was decreased after adding 5000 IU/mL (P<0.05), and with the increase of the dose of UK , the inhibitory effects enhanced, showing a time and dose dependent manner. 6. No apoptosis body was found by light and fluorescent microscopy . No apoptosis cells were detected by flow cytometry. Innovation and Peculiarity: We discover that FB and MC from the pleura could secrete TGF-betai, VEGF, bFGF and PAI-1. The cytokines are involved in the occurrence and development of pleural fibrosis. It enrich biological function of FB and MC. To discover biological function of UK , enrich the mechanism on prevention and treatment of pleural fibrosis. We discover that the collagen consists of Col I and Col III in pleural fibrosis.