The Role Of MicroRNA-92a In Acute Respiratory Distress Syndrome And Its Regulatory Mechanism

Objective : To investigate the role of miR-92 a in acute respiratory distress syndrome and its related molecular mechanisms,and to determine the function of miR-92 a in a cellular model of acute respiratory distress syndrome.Methods: LPS(10ug/ml)was used to stimulate HPMECs to establish an ARDS cell model.Six groups were set up: control group,LPS stimulated for 3h,6h,12 h,24h,and 48 h.And qRT-PCR was used to detect the miR-92 a expression and determined the optimal time for LPS treatment.Then,miR-92 a inhibitor was used to knock down miR-92 a expression,and control group,LPS group,inhibitor NC + LPS group and miR-92 a inhibitor+ LPS were established.Monolayer cell permeability,cell migration and tube formation were measured.ELISA was used to detect the expression of IL-10,IL-6 and TNF-? in the cell supernatant.Western blot and qRT-PCR were used to detect the expression changes of VE-cadherin and ITGA5.What's more,Luciferase reporter assay was used to detect whether ITGA5 is a target gene of miR-92 a.Finally,western blot was used to detect relatedmolecules expression of PI3K/Akt signal pathway.Results: MiR-92 a expression in HPMECs was significantly increased after treatment with LPS,compared with the control group,and 24 h is the optimal time for LPS treatment.And the monolayer permeability was decreased,the cell migration and tube formation were enhanced after transfection with miR-92 a inhibitor,compared with the inhibitor NC group.The mRNA and protein expression of VE-cadherin were increased,and inflammatory response was declined after inhibition miR-92 a,compared with inhibitor NC + LPS group.Meanwhile,ITGA5 had a negative regulation relationship with miR-92 a,and luciferase reporter assay confirmed that ITGA5 is a target gene of miR-92 a.In addition,western blot showed that p-Akt expression was increased after inhibition miR-92 a,compared with the inhibitor NC + LPS group.Conclusion: MiR-92 a expression is increased in LPS-induced HPMEC injury,and miR-92 a may target ITGA5 through PI3K/Akt signaling pathway to promote LPS induced HPMEC endothelial barrier dysfunction and inflammatory response.Inhibition miR-92 a can ameliorate the damage effect of LPS in HPMECs.These suggest that miR-92 a may have potential as a prognostic indicator and a future target for the treatment of acute lung injury(ALI)/ARDS.