Comprehensive Analysis of LncRNA-mRNA Expression Profiles and the ceRNA Network Associated with Pyroptosis in LPS-Induced Acute Lung Injury.

PURPOSE

To explore the molecular mechanism and search for candidate lncRNA and mRNA associated with pyroptosis in the gene expression profile of LPS-induced acute lung injury (ALI).

METHODS

We investigated lncRNA and mRNA expression in lipopolysaccharide (LPS)-induced ALI at an early stage. RNA sequencing (RNA-Seq) was carried out to analyze lncRNA and mRNA expression profiles between the LPS-induced and control groups. We used bioinformatics analysis to predict target genes of early differential lncRNAs among obtained the differential mRNAs.

RESULTS

A total of 78 lncRNAs and 248 mRNAs were upregulated at 2 hours and downregulated at 9 hours, and 21 lncRNAs and 107 mRNAs were downregulated at 2 and upregulated at 9 hours in early ALI models. We predicted 7 cis-and trans-regulated target genes of the top 20 lncRNAs. Gene Ontology (GO) analysis indicated that the target genes for the screened lncRNAs were most enriched in three-terms: regulation of protein serine/threonine kinase activity, pertussis, and cellular response to LPS. Additionally, target genes of lncRNAs were the top three enriched in pertussis, osteoclast differentiation, and cAMP signaling pathways with Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. We also identified vital mRNAs and lncRNAs. Protein-protein interaction (PPI) network analysis suggested that Tnf, Jun, and Atf3 were the top three key genes. Hub lncRNA4344 (NONRATT004344.2) and cis-regulated target mRNA (NLRP3) were validated in vitro. Finally, luciferase assay results confirmed that lncRNA4344 sponged miR-138-5p to promote pyroptosis in inflammatory responses to LPS-induced acute lung injury by targeting NLRP3.

CONCLUSION

Based on analysis of lncRNA and mRNA expression profiles by RNA-Seq and experimental verification, this study is the first to reveal that lncRNA4344 sponged miR-138-5p to promote pyroptosis in inflammatory responses of LPS-induced acute lung injury by targeting NLRP3. These newly identified lncRNA, miRNA, and mRNA might be novel potential targets for early treatment and prevention in early ALI.