Activation of necroptosis in a rat model of acute respiratory distress syndrome induced by oleic acid / 生理学报

The present study was aimed to investigate the role of necroptosis in the pathogenesis of acute respiratory distress syndrome (ARDS). The rat model of ARDS was induced by intravenous injection of oleic acid (OA), and observed for 4 h. The lung injury was evaluated by arterial blood gas, lung wet-dry weight ratio (W/D) and histological analyses. Simultaneously, bronchoalveolar lavage fluid (BALF) was collected for total and differential cell analysis and total protein determination. Tumor necrosis factor alpha (TNF-α) level in BALF was determined with a rat TNF-α ELISA kit. Expressions of receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like protein (MLKL) in lung tissue were determined by Western blot and immunohistochemical staining. The interaction between RIPK1 and RIPK3 was explored by immunoprecipitation. The results showed that, compared with those in control group, total white blood cells count (WBC), polymorphonuclear percentage (PMN%), total protein concentration, TNF-α level in BALF, W/D, and the alveolar-arterial oxygen tension difference (P(A-a)O) in OA group were significantly increased at 4 h after OA injection. Western blot and immunostaining further showed remarkably increased expressions of RIPK1, RIPK3 and MLKL in lung tissue from OA group. Additionally, immunoprecipitation results indicated an enforced interaction between RIPK1 and RIPK3 in OA group. Collectively, the TNF-α level in BALF and the RIPK1-RIPK3-MLKL signaling pathway in lung tissue were found to be upregulated and activated with the process of ARDS. These findings implicate that RIPK1/RIPK3-mediated necroptosis plays a possible role in the pathogenesis of ARDS, which may provide a new idea to develop novel drugs for the therapy of ARDS.

Evaluation of bFGF effect on corneal collagen and nerve recovery following LASIK with confocal microscopy / 中华实验眼科杂志

Background Basic fibroblast growth factor(bFGF)secreted by cornea after injury is important to cytothesis,collagen fibers reconstruction and axons recovery.However,the local bFGF is not enough for the reparation process.Objective This study aimed to observe the findings of corneal collagen and nerve recovery under the confocal microscopy through focusing(CMTF) in the eyes with intervene of exogenous recombinant bFGF(rbFGF) after excimer laser in situ keratomileusis(LASIK).Methods LASIK rabbit models were binocularly created in 34 clean New Zealand white rabbits.The tobramycin combined with dexamethasone were dropped after operation for 10 days in bilateral eyes.rbFGF was topically administered in the right eyes of rabbits from 1 day through 3 months after LASIK,and lubricant was used in the left eyes at the same way.The corneal collagen and nerve recovery,keratocyte and endothelial cell counting were observed with CMTF at the 1st week,2nd week,2nd month,3rd month and 5th month after LASIK.Results Total 19 rabbits were meted the request of LASIK models.The keratocyte densities in anterior stroma of both groups reached the lowest level at the 2nd week and the highest level at the 3rd month.Otherwise,haze changed on the contrary.No statistically significant differences were found in anterior stroma keratocyte densities,haze grade,grey value between rbFGF group and lubricant group at various time points after operation(P＞0.05).The nerve cord densities of both groups were increased gradually,and those under the epithelial basement membrane were more dominant.The nerve density of the anterior stroma of rbFGF group was significant higher than the lubricant one in the 2nd group(P=0.038).The considerably elevated the subepithelial nerve density value was also seen in rbFGF group compared with lubricant at 5 months after operation(Z=-2.060,P=0.039).No any corneal neovascularization occurred in both groups through experiment duration.The positive correlation was found between grey value with haze grade in rbFGF group(b=22.687,F=37.975,P=0.000) and lubricant group(b=20.410,F=18.516,P=0.000).However,haze grade was not significant correlated with stromal keratocyte density(rbFGF group:b=0.001,F=0.164,P=0.668;lubricant group:b=-0.002,F=1.896,P=0.178).Conclusion Exogenous bFGF can improve the recovery of corneal nerve and regeneration of keratocyte after LASIK.No evidence of bFGF promoting corneal neovascularization is found in this experiment.