ABSTRACT
<p><b>BACKGROUND</b>p120 catenin (p120ctn) is an adheren junction protein that regulates barrier function, but its role has not been explored in alveolar edema induced by ventilation. We measured stretch-induced cell gap formation in MLE 12 cells due to the loss of p120. We hypothesized that alveolar permeability was increased by high lung inflation associated with alveolar epithelia cell tight junctions being destroyed, which resulted from the loss of p120.</p><p><b>METHODS</b>Cultured MLE12 cells were subjected to being stretched or un-stretched (control) and some cells were pretreated with pp2 (c-src inhibitor). After the end of stretching for 0, 1, 2, and 4 hours, the cells were lysed, and p120 expression and c-src activation was determined by Western blotting analysis. In vivo, SD rats were taken to different tidal volumes (Vt 7 ml/kg or 40 ml/kg, PEEP = 0, respiratory rate 30-40 betas/min) for 0, 1, 2, and 4 hour and some were pretreated with pp2, and alveolar edema was calculated.</p><p><b>RESULTS</b>It was found that p120 expression was reduced and c-src activation increased in a time-dependent and strain-dependent manner due to cyclic-stretch of the alveolar epithelial cells. These changes could be reversed by inhibition of c-src. We obtained similar changes in rats when they were subjected to large tidal volumes and the alveolar edema increased more than in rats in the low Vt group. Pretreated the rats with inhibition of c-src had less pulmonary edema induced by the high tidal volume ventilation.</p><p><b>CONCLUSIONS</b>Cyclic stretch MLE 12 cells induced the loss of p120 and may be the same reason by high tidal volume ventilation in rats can aggravate alveolar edema. Maintenance of p120 expression may be a novel therapeutic strategy for the prevention and treatment of ventilation induced lung injury (VILI).</p>
Subject(s)
Animals , Mice , Rats , Blotting, Western , Catenins , Physiology , Cells, Cultured , Pulmonary Alveoli , Pathology , Pulmonary Edema , Pathology , Rats, Sprague-Dawley , Tidal Volume , Ventilator-Induced Lung Injury , PathologyABSTRACT
Objective To investigate the proliferative characteristics of fibroblast-like synovial cells (FLS)in osteoarthritis in vitro and the mechanism of the immunosuppressive effect of total glucusides of paeony(TGP).Methods FLS of OA and non-inflamed synovium(NS)were cultured and identified in vitro in the presence or absence of TGP.After incubation,the survival fraction(SF)of FLS was evaluated by MTI' and the TNF-?,IFN-?and bFGF level in cultured FLS supernatant was measured by ELISA.The expression of FLS c-los mRNA and cell cycle of OA-FLS was observed by RT-PCR and flow eytometry respectively at the same time.Results No statistical significant differences were noted between the OA and NS FLS in pro- liferating double time.High doses of TGP suppressed FLS-SF more evidently in OA patients than in NS(P0.05).Conclusion High dose TGP can inhibit OA-FLS proliferation,modulate cy- tokine secretion and c-fos expression in OA.This suggests that TGP has immunosuppressive effect on OA syn- ovitis,probably by preventing the synovial hypertrophy in OA.
ABSTRACT
Objective To investigate the proliferation and differentiation characteristics of fibroblast like synovial cells(FLS)in rheumatoid arthritis(RA)in vitro and the mechanism of the immunosuppressive effect of differentiation inducers, such as all trans retinoid acid(ATRA), ealcitriol [1,25(OH)_2D_3] and dexamethasone(DEX). Methods FLS of knee synovial tissues from RA patients were cultured and identified in vitro in the presence or absence of ATRA, 1,25(OH)_2D_3 and DEX respectively. Synoviocyte proliferation in RA were measured by MTT colorimetrie assay and the survival fraction(SF)of FLS was evaluated. Cell cycle of FLS was observed using fluorescence-activated cell sorting(FCS)method in RA patients. Results The identified synovial cells in patients with RA were FLS(Vimentin and Fibronectin expression was positive), and hadn't been transformed or differentiated to adipocytes and osteoblasts with the three inducers. The SF of all RA-FLS interfered by ATRA, 1,25(OH)_2D_3 and DEX was much lower than that without drugs vehicle group in RA-FLS(P