Identification And Functional Study Of LPS Induced Mouse Liver Specific LncRNA

Backgrounds:Sepsis should be defined as life-threatening organ dysfunction caused by a dysregulated host response to infection.Sepsis,a syndrome of physiologic,pathologic,and biochemical abnormalities induced by infection,is a major public health concern.Sepsis has been called a hidden public health disaster.Long non-coding RNAs(lncRNA)are a large class of non protein-coding transcripts that are greater than 200 bases in length.Circular RNA(circRNA)is one type of noncoding RNA that forms a covalently closed continuous loop.Similar to long noncoding RNA(lncRNA),circRNA can act as microRNA(miRNA)'sponges' to regulate gene expression.So far,there have been no systematic studies on circRNA abundance and expression profiles in mouse liver tissues in sepsis.Aims:Using the latest transcriptomic sequencing analysis method,Baimai Keyun's liver polyA tail RNA enrichment transcriptome of LPS(20 mg/kg bw)induced mouse sepsis at different time points(Oh,2h,8h and 24h)Sequencing data were analyzed for polyA tail IncRNAs,and lncRNA 906 that was specifically elevated in the early stages of sepsis was selected for in-depth study of gene structure,RNA secondary structure,coding potential,tissue localization,and cell expression in different tissues.LncRNA 906 Knockout mice to investigate the effect of lncRNA 906 on LPS-induced mouse death and whole-transcriptome sequencing of LPS-stimulated wild-type mice and lncRNA 906-knockout mouse liver tissues to screen lncRNA 906 potential target genes.Results:1 PolyA tail lncRNA mining analysis of liver transcriptome data at different time points in LPS-induced mouse sepsi.Gene expression profiling data of mRNA in liver of mice with sepsis induced by LPS was obtained via library preparation and sequencing after employment of polyA tails enrichment of RNA in mice liver tissue stimulated by LPS for 2h,8h and 24h.3,056 lncRNAs were identified,499 of which were differentially expressed.2 IncRNA 906 is located on chromosome 15 of mouse genome 103095188-103100906.The genome span is 5719 bp.It consists of 3 exons and the length of the transcript is 2982 nt.Both MFE algorithm and centroid algorithm analysis indicated that the secondary structure of lncRNA 906 is quite complicated.CPC analysis,CNCI analyis,CP AT analysis and Pfam domain analysis of protein structure all suggested that IncRNA 906 do not have coding potential.3 2h after LPS stimulation,IncRNA 906 level in liver elevated significantly.Its expression in heart,kidney,colon were down-regulated,while its expression in brain,spleen,stomach,small intestine and appendix remained same.lncRNA 906 didn't expressed in lung.4 The expression of IncRNA 906 induced by LPS relied on TLR4 receptors.5 Knockout lncRNA 906 has no influence upon immune system of mice.6 Whole liver transcriptome analysis of LPS 4 h and intraperitoneal injection of LPS in WT mice and KO 906 mice:The fold change was greater than 2 and p value was less than 0.05.Compared with WT,there were 5 differentially expressed lncRNAs in the KO 906 group.There were 3 up-regulated and 2 down-regulated lncRNAs.And there were 43 differentially-expressed mRNAs,of which there were 23 up-regulated and 20 down-regulated.There were 6 differentially expressed TUCPs,of which 5 were up-regulated while one down-regulated.There were 44 differentially expressed circRNAs,of which 28 were up-regulated and 16 were down-regulated.There are 2 differentially expressed miRNAs,all of which are down-regulated.7 lncRNA 906 protects mice from endotoxemia induced fatality.Conclusions:1 LPS-induced liver sepsis in mice at different time points through the polyA tail RNA enrichment method can also be analyzed to obtain differentially expressed polyA tail lncRNA,but the difference in the number and expression of abundance is not as good as mRNA.2 Identification and functional study of LPS induced mouse liver specific IncRNA 906.Without LPS stimulation,lncRNA 906 can merely be detected,after LPS stimulation,it was detected both in nucleus and cytoplasm.The expression of lncRNA906 induced by LPS relied on TLR4 receptors.3 Knockout lncRNA906 has no influence upon immune system of mice.4 lncRNA 906 knockout had a certain effect on the liver transcriptome of LPS-induced mouse sepsis for 4 hours,among which 43 differentially expressed mRNAs may be potential target genes of IncRNA 906.5 lncRNA906 knockdown reduced the survival time of LPS-induced sepsis in mice,suggesting that the specific elevation of IncRNA 906 in the early stages of sepsis has a protective effect on endotoxic shock model mice.