WNT5a Mediates Nkx2.1 Expression Through NANCI In Acute Lung Injury Induced By LPS

Background: Long noncoding RNAs(lnc RNAs)have emerged as a new gene regulation in recent years and regulate various biological processes.NANCI,an intergenic lnc RNA,is expressed in the developing lung,thyroid and ventral forebrain with pattern to Nkx2.1.Nkx2.1 plays an important role in the physiology of lung development and maintaining the normal form of the lung.Nkx2.1,as an important transcription factor,is regulated by many pathways,including Wnt pathway.Wnt5 a,a member of the non-canonical Wnt pathway,is essential for the stability of alveolization and epithelia transformation in the lung.Acute lung injury(ALI)is a severe disease with high mortality.The pathology is mainly due to the damage of alveolar and capillaries and is characterized by intractable hypoxemia and non-cardiogenic pulmonary edema.Interstitial thickening and alveolar disorder can be found under microscope.However,the precise mechanism of Wnt5 a,NANCI and Nkx2.1 remain unclear.Methods: 80 mice were randomly divided into model group and control group.The model of acute lung injury(ALI)was contrusted by intratracheal administration of LPS.Lung tissues were collected at post-administration 3h,6h,12 h,24h and 48 h.The lung morphology was observed by microscope.The expression levels of Wnt5 a,Nkx2.1,SPC and AQP5 were measured by real-time PCR,immunoblotting and immunofluorescence.The expression of NANCI was detected by PCR.Cells with low expression of Wnt5 a or NANCI were constructed by lentivirus.The transcription and translation of genes in the cells were tested by PCR,immunoblotting and immunofluorescence.The culture medium was collected to detect the protein levels of selected Wnt5 a by ELISA.Results: In vivo,compared with the control group the morphology of tissues in the model group changed gradually after 6h.The interstitial thickening of the lung appeared at 6h followed by the alveolar structure changed.The expression levels of NANCI,Nkx2.1,SPC and AQP5 in the model group were decreased compared with the control group(p<0.05).The levels of expression were not exactly consistent at different time points.Wnt5 a was inhibited in the m RNA level,but there was a slight upregulated in the protein level at 3h,24 h and 48h(p<0.05).In vitro,when NANCI was knockdown (p<0.05),the expression of Wnt5 a was increased and Nkx2.1 and SPC were decreased(p<0.05).However,when Wnt5 a was knockdown,all of them were decreased(p<0.05).Conclusion: Wnt5 a,NANACI and Nkx2.1 were involved in ALI,especially the pathology of alveolar injury.NANCI modulated the process of epithelia damage through Nkx2.1 in ALI and the mechanism may be regulated by Wnt5 a.There was a feedback regulation between Wnt5 a and NANCI.