| Acute respiratory distress syndrome(ARDS)is a common clinical critically ill,is the acute respiratory failure caused by the lung inflammation.ALI / ARDS is mainly caused by severe pulmonary inflammation which destroyed alveolar cell barrier,then a large number of inflammatory cells such as neutrophils and other large influx into the alveoli,and these inflammatory cells can release a large number of inflammatory mediators and cytotoxic substances.They caused the aggregation of protein-rich liquid in alveolar and alveolar surface active material was damaged,so lung ventilation is dysfunction.Because ARDS is a clinically high incidence of morbidity and mortality,so the study of acute respiratory distress syndrome has been popular.Although after years of research,but the pathogenesis of ARDS is still not clear and the effective treatment is deficiency,ARDS still has a lot of problems to be solved.miRNA as one of non-coding RNAs,plays an important role in the regulation of genes.The miRNAs can regulate the process of cells differentiation and multiple signaling pathways.Therefore,it is closely related to many normal and abnormal pathophysiological processes and is involved in many diseases.A large number of studies have found that multiple miRNAs(miR-146 a,miR-155,miR-16,etc.)are closely related to the progress and outcome of ARDS.HMGB1 is a hot factor in the study of inflammation.It increases lately in the inflammatory response than other inflammatory factors,but the duration is long.It play an important role in the inflammatory response.HMGB1 can participate in inflammatory response through a variety of cellular signaling pathways(such as TLRs,RAGE,cPKC and other pathways),and miRNAs can participate in the regulation of multiple signaling pathways.Therefore,we investigated this study to investigate the effect of miR-142-3p on the inflammatory response of lipopolysaccharide-induced rat alveolar macrophages.It may further improve the biological markers and provide a new direction for treatment of ARDS.Part ? Study on the expression of miR-142-3P and HMGB1 in alveolar macrophage inflammation stimulated with LPSObjective To observe the effects of miR-142-3P and HMGB1 in alveolar macrophage inflammation stimulated with LPS.Methods NR8383 cells were cultured in vitro.The cells were stimulated with different concentrations of LPS(0,100,1000,10000 mg / mL)for 0h,6h,24 h and 48 h.The supernatants and cells were collected at different concentrations for 0h,6h,24 h and 48 h respectively.The expression of HMGB1 protein in the supernatant was detected by RT-PCR and the expression of miR-142-3p and inflammatory factor was detected by RT-qPCR.The expression of HMGB1 in the supernatant was detected by enzyme-linked immunosorbent assay.Results The expression of TNF-?,IL-6 and IL-1? in rat alveolar macrophages NR8383 stimulated with different concentrations of LPS(100,1000,10000 mg / mL)for 24 h was significantly higher than that in cells treated with LPS(0 ng / mL)(P<0.05).The effective concentrantion of LPS was 100 ng/ml,which can stimulate the expression of various inflammatory factors.The expression of miR-142-3p in NR8383 cells stimulated with LPS was significantly increased(P<0.05),which reached the peak at 48 h,and the concentration of HMGB1 in cells supernate was also significantly increased(P<0.05),but which reached the peak at 24 h and then decreased to a certain level.Conclusions The effective concentrantion of LPS was 100 ng/ml,which can stimulate the expression of various inflammatory factors.Both miR-142-3p and HMGB1 were involved in the inflammatory response of LPS-induced alveolar macrophages,and there may be regulatory relationships between them.Part ? miR-142-3p negatively regulates alveolar macrophage inflammation stimulated with LPS by HMGB1Objective To explore effect of miRNA-142-3p on the expression of HMGB1 in alveolar macrophage inflammation induced by LPS.Methods NR8383 cells were cultured in vitro.The rat alveolar macrophages were transfected with different concentrations of miRNA-142-3p minics for 24 hours.The cells were collected at different concentrations of transfected cells.RT-qPCR was used to detect the expression of miR-142-3p in the cells.The remaining cells were stimulated with 100 ng/mL LPS for 0h,6h,24 h and 48 h.The supernatants and cells were collected at different concentrations and times.The expression of HMGB1 protein in the supernatant was detected by RT-PCR and the expression of miR-142-3p and inflammatory factor was detected by RT-qPCR.The expression of HMGB1 in the supernatant was detected by ELISA.Results The expression of miR-142-3p in rat AM NR8383 cells transfected with miR-142-3p mimics was detected.The results showed that the expression of miR-142-3p,compared with untransfected group,was significantly increased in the NR8383 cells transfected with miR-142-3p mimic(P<0.05).The expression of HMGB1 mRNA in NR8383 cells and the expression of HMGB1 protein in cell culture medium and cells were detected.The the expression of miR-142-3p,compared with untransfected group,was significantly increased in the NR8383 cells transfected with miR-142-3p mimic(P<0.05),while the expression of HMGB1 mRNA and protein was significantly decreased(P<0.05).The expression of HMGB1 in the supernatant of the transfected group and the untransfected group stimulated with LPS was detected by ELISA at 0h,6h,24 h and 48 h.The results showed that the content of HMGB1 in miR-142-3p mimic transfection group,compared with untransfected group,was significantly decreased at 0,6 and 24 h(P<0.05).The expression of inflammatory factor(TNF-??IL-6?IL-1? and MIP-2? mRNA)in the cells of the transfected group and the untransfected group stimulated with LPS was detected by RT-qPCR at 0h,6h,24 h and 48 h.The results showed that the content of inflammatory factor in miR-142-3p mimic transfection group,compared with untransfected group,was significantly decreased at 0,6,24 and 48 h(P<0.05).Conclusions miRNA-142-3p could regulate the expression of inflammatory factors through down-regulating HMGB1. |
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