Expression And Function Research Of Long Non-coding RNAs In Severe Acne

[Objectives]Acne is a common chronic inflammatory skin disease involving hair-follicles and sebaceous glands.Especially,severe acne has the characteristics of damaging,prolongation,recurrence and hard to treat.Recently,studies have shown that lncRNAs can influence gene expression and participate in the pathogenesis and pathology of multifarious skin diseases.However,the expression and underlying function of lncRNAs in severe acne we still unclear.In this study,we analyzed the differentially expressed IncRNAs to explore the possible mechanism and provide a new direction for the prevention and precise treatment of severe acne.[Materials and Methods]Using high-throughput sequencing technology combined with bioinformation analysis method,the differential expression profiles of lncRNAs,miRNAs and mRNAs were obtained form 5 severe acne patients and 7 healthy volunteers.The lncRNAs were the center of our research.We predicted the target genes of differentially expressed lncRNAs and performed the analysis of GO ontology and KEGG pathway.In addition,we applied TargetScan and miRanda software to predict differential mRNAs and lncRNAs that could bind to miRNAs,then to construct an interaction network.Subsequently,we chose significantly expressed lncRNAs for real-time q-PCR in another 4 pairs of samples to validate the reliable of RNA-seq.Moreover,changes in the expression of target mRNAs were detected by transfection of miRNAs in cultured HaCaT cells to initially explore the functions of lncRNAs.Finally,the expression of lncRNAs induced by Propionibacterium acnes were analyzed in an acne cell model constructed in vitro.[Results]RNA-Sequencing results showed that a total of 1145 lncRNAs were significantly differentially expressed in severe acne cases compared to healthy controls,of which 402 lncRNAs were upregulated and 743 lncRNAs were downregulated(|log2 FC|>0.58,P<0.05).The functions of differentially expressed lncRNAs with relevance in severe acne are major related to inflammatory responses,immune processes,small molecule metabolism and signaling pathways.In addition,based on the principle of target gene sequence complementarity,a ceRNA network of lncRNA-miRNA-mRNA was mapped using 45 miRNAs significantly differentially expressed in severe acne(q<0.01,|log2FC|>2),in which lncRNAs may act as competitive endogenous RNAs binding miRNAs to regulate target gene expression and influence the development of severe acne.Quantitative real-time PCR validated the expression of candidate molecules in independent samples and identified 6 mRNAs which including IFI30,TNFRSF12A,NFAT5,AUTS2,WASL,STMN2 and 5 lncRNAs which including ENST00000492343,ENST00000442293,ENST00000230914 ENST00000595013,ENST00000332858,the expression of which was consistent with the trend of RNA-seq results and statistically significant.Based on expression and functional analysis,lncRNAs targeting IFI30 were screened and found that IFI30 was elevated in severe acne in both mRNA and protein expressional level.LncRNA-MIR4435-2HG,which is up-regulated in severe acne,was positively correlated with the expression of its potential target gene IFI30,and in vitro cell models further revealed that P.acne stimulation induced the expression of MIR4435-2HG,suggesting that the lncRNA-MIR4435-2HG may positively regulate the expression of the target gene IFI30 and participate in the development of severe acne by affecting the microbial immune process induced by P.acne.[Conclusions]In this study,we obtained differential expression profiles of lncRNAs in severe acne,which may regulate gene expression in severe acne involving inflammatory responses,immune processes,small molecule metabolism and signaling pathways.Differentially expressed lncRNAs in severe acne may act as competitive endogenous RNAs binding miRNAs,or as cis/trans acting elements,among other ways,to regulate the expression of target genes.The lncRNA MIR4435-2HG with increased expression in severe acne may positively regulate the expression of the target gene IFI30 and affect the microbial immune process induced by P.acne,which is involved in the pathogenesis of severe acne.