Study The Effect Of Osteopontin On Acute Lung Injury Of Rats Induced By Hpopolysaccharide

Objective:1. To investigate the expression and function of osteopontin (OPN) in lung tissue bomogenatein establishing a actue lung injury (ALI) model of rats induced by Hpopolysaccharide injected through tail vein.2. To investigate the effect of OPN on the expression of interleukin-10 (IL-10), tumor necrosis factor-a (TNF-a), interleukin-4 (IL-4) and interferon-y (IFN-y) in the serum of the ALI models of rats.3. To explore the mechanism of OPN regulating the ALI models of rats induced by LPS.Methods:1.3 approaches in establishing the acute lung injury model in rats:56 male SD (Sprague Dawley) rats of SPF(Specific pathogen Free) class were randomized into 3 groups; (1) control group,n=8; (2)ALI group, n=24;(3) treated group, n=24. ALI group and treated group were subdivided into 3 subgroups respectively, e. g.2 hours group,4 hours group,8 hours group. n=8. Control group were injected with lml normal sodium and normal sodium 0.5ml/kg 5 minutes later through tail vein. LPS 6mg/kg adding normal sodium to 1ml and normal sodium 0.5ml/kg 5 minutes later injected through tail vein established ALI Group, n=24;LPS 6mg/kg add normal sodium to 1ml injection and Anti-OPN-Ab (1:32) 0.5ml/kg 5 minutes later injected through tail vein established Anti-OPN-Ab treatment group, n=24;every 8 rats of ALI group and Anti-OPN-Ab treatment group were randomized to sacrifice at the time 2 hours,4 hours and 8 hours after all the treatment.At the same time keeping the specimenes to measure.2. Comparing the degree of acute lung injury in each group and evaluating ALI models with the PaO2,the low right lungs wet/dry (W/D), the pathology examination of the low left lungs by HE staining and scoring acute lung injury by two and more experienced pathologists according to the hemorrhage, pulmonary atelectasis, pneumonedema.3. Expression of TNF-a, IL-10, IFN-y and IL-4 in the serum segregated by 2000 rolls in a minute were assessed by ELISA.4. Expression of OPN in lung tissue bomogenatein was analysised by western blotting,and the results were expressed by OPN/β-actin, Reinhoit Zahl after the measurment of protein by BCA.Results:l.The lung W/D proportionality, acute lung injury scores, expression of TNF-a, expression of IFN-y, IL-10 and IL-4 in serum, TNF-a/IL-10 and IFN-y/IL-4 proportionality, and expression of OPN in lung tissue bomogenatein:ALI group and treated group had significantly increased as compared with NC groups (all P<0.05), but PaO2 had significantly decreased.2. The lung W/D proportionality, lung injury scores, expression of IFN-y, IL-10 and IL-4 in serum, TNF-a/IL-10 and IFN-y/IL-4 proportionality, and expression of OPN in lung tissue bomogenatein:the 4th ALI group had significantly increased as compared with the 2th and 8th ALI groups (all P <0.05),but the expression of TNF-αin the 2th ALI group had significantly increased as compared with the 4th and 8th ALI groups (all P<0.05)3.After receiving Anti-OPN-Ab treatment, The lung W/D proportionality, lung injury scores, expression of.IFN-y and TNF-αin serum, TNF-a/IL-10 and IFN-y/IL-4 proportionality of the treated group had significantly decreased as compared with the ALI group (all P<0.05),but the PaO2,the expression of IL-10 and IL-4 significantly increased (all P<0.05) and the expression of OPN in lung tissue bomogenatein not significantly decreased (all P>0.05)Conclusion:1.The ALI model of rats can be successfully established by Hpopolysaccharide injecting in tail vein. The various changes of lung injury were remarkable and typical at the time of 4th hour.So this kind of ALI model of rats should be utilized as an preferable model for the research on human ALI induced by various severe infection, especially by G- bacillus.2. The OPN in lung tissue bomogenatein of ALI induced by LPS was greatly increased.3. The up-regulation of OPN might aggravate greatly the pathology changes and play an important role in genesis and development of ALI model in rat induced by LPS injecting in tail vein..4. OPN might aggravate greatly the pathology changes of ALI induced by LPS, which be related to up-regulating expression of TNF-a and IFN-y and down-regulating expression of IL-10 and IL-4 in serum.