Bioinformatics Analysis And Clinical Research Of MicroRNAs In Chronic Periodontitis

Backgrounds:Disorders of micro RNAs(mi RNAs)have been reported to be characteristic of multiple diseases,including periodontal disease,and have been confirmed in cell and animal models.Although there have been studies on the expression of mi RNA in gingival tissue,the sample size is relatively small and the types of mi RNA are emerging in endlessly.The aim of this study was to investigate the target genes,biological functions and signal transduction pathways of differentially expressed mi RNAs in chronic periodontitis(CP)by bioinformatics analysis,and verify their differential expression further in gingival tissue to analyze the correlation between the mi RNAs of differential expression and periodontal clinical indicators,and to explore the mechanism of mi RNAs in periodontitis.Methods:1.Search the Gene Expression Omnibus(GEO)for mi RNAs expression profiles of periodontitis gingival tissue GEO2 R was used to screen the obtained data.The target genes of the mi RNAs that have been experimentally verified were screened in the online database of mi RWalk and mi RTar Base,and the related functions and pathways of the target genes were enriched and analyzed through the DAVID database.2.Differential expression of selected mi RNAs was detected by real-time polymerase chain reaction(q PCR).According to P<0.05,the difference was statistically significant.Pearson correlation coefficient was used to analyze the intensity of the association in CP group between mi RNAs and periodontal clinical parameters including plaque index(PI),gingival index(GI),probing depth(PD),oral health index(OHI)and attachment loss(AL).Results:1.We got a microarray dataset numbered GSE54710.9 mi RNAs with significant difference expression were obtained by screening database.mi R-451,mi R-486-5p,mi R-223,mi R-671-5p,mi R-3917,mi R-483-5p up regulated,and mi R-1246,mi R-203,mi R-1260 down regulated.A total of 176 predicted genes were obtained which include 18 of mi R-486-5p,14 of mi R-223,50 of mi R-671-5p,3 of mi R-3917 3,35 of mi R-483-5p,4 of mi R-1246,4 of mi R-203a-5p and 48 of mi R-1260.The GO analyze of target genes of up regulated mi RNAs revealed 41 of biological process(BP),12 of cellular component(CC),15 of molecular function(FC)and KEGG enrichment of 40 signaling pathways.The GO analyze of target genes of down regulated mi RNAs revealed 3 of BP,3 of CC,4 of FC and KEGG enrichment of 1signaling pathways.A total of 30 clinical samples of gingival tissue were collected for q PCR,including 15 cases in CP group and 15 cases in control group of healthy people.2.The age and gender difference between experimental group and control group were not statistically significant P>0.05.The two groups were comparable.The clinical parameters were significantly increased in the experimental group,P<0.05.The expression of mi R-451?mi R-223 and mi R-671-5p in the experimental group was relatively increased,P<0.05.Compared with the control group,the expression levels of mi R-486-5p and mi R-3917 were increased,but the difference was not statistically significant,P>0.05.The expression levels of mi R-1246 and mi R-203 decreased significantly,P<0.05.The expression level of mi R-1260 decreased slightly,but the difference was not statistically significant,P>0.05.The results of Pearson correlation analysis showed that the expression level of mi R-486-5p was positively correlated with PD value.But there was no significant correlation between other mi RNAs and periodontal clinical indices.Conclusions:1.Bioinformatics analysis reveals a range of target genes and pathways associated with differentially expressed mi RNAs in CP.For example,neurotrophic protein signaling pathways may play a role in periodontal tissue regeneration and the ability of mi RNAs to regulate chemokine signaling pathways to enhance inflammatory response may have profound implications for CP progression;2.Compared with the healthy population,the expression of mi RNAs in gingival tissue of CP patients changed.The relative expression of mi R-451,mi R-223 and mi R-671-5p increased,and the relative expression of mi R-1246 and mi R-203 decreased,which was consistent with the result of expression spectrum.There was no significant correlation between the mi RNAs of differential expression and periodontal clinical indices.Therefore,we speculated that the expression level of the detected mi RNAs was not significantly related to the degree of periodontal inflammation.In the future,we can continue to verify it based on a larger sample size.