| ObjectiveBronchial asthma(asthma)is a common chronic respiratory disease with complicated pathogenesis.Recent years,the incidence of asthma is increasing.However,its exact mechanism is still unclear.microRNAs(miRNAs)are a class of endogenous non-coding single-stranded small RNAs of about 22 nt in length.Many studies found that miRNA can control 30%of all genes in the human genome,and plays important roles in various biological processes,including cell proliferation,differentiation and apoptosis,metabolism,tissue repair,biological development.Also,miRNA is regarded to participate in asthma and other diseases.However,the specific types of miRNA and the signal mechanism in asthma are not clear yet.Therefore,the objective of this study is to find the differential expression of miRNA in bronchoalveolar lavage fluid(BALF)in asthmatic children and explore the possible mechanism of action.MethodsA total of 15 children with asthma were enrolled as asthma group and another 12 children with airway foreign removed within 24 hours were enrolled as control group.The levels of miRNAs expression were measured by miRNA microarray and verified by quantitative RT-PCR.The mRNA and protein levels of differentially expressed miRNAs(miR-34 and miR-200 families)target genes(E-cadherin)were detected by qPCR and ELISA,respectively.Results1.Among BALF cells of control group,over 800 miRNAs were found.The most abundant 10 miRNAs were let-7b-5p,miR-191-5p,miR-23a-3p,miR-4454,miR-24-3p,miR-7704,let-7c-5p,let-7a-5p,miR-103a-3p,and miR-3960.2.The levels of 65 miRNAs in the BALF cells of asthma group were different against these of controls,including 43 down-regulated miRNAs and 22 up-regulated miRNAs.It was noted that 6 miRNAs of miR-34/449 family and 7 miRNAs of miR-200 family were decreased,which account for 30.2%(13/43)down-regulated miRNAs in the BALF cells from asthmatic children.3.For miR-34/449 family and miR-200 family of 13 differentially expressed miRNAs,qRT-PCR analysis confirmed that 10 miRNAs were identical to the gene chip,including miR-34b-3p,miR-34b-5p,miR-34c-3p,miR-34c-5p,miR-200a-3p,miR-200a-5p,miR-200b-3p,miR-200b-5p,miR-200c-3p,and miR-141-3p.4.E-cadherin,the predicted target of miR-34 family and miR-200 family,was down-regulated in pediatric asthma(P<0.05).ConclusionmiRNAs,especially the miR-34 and miR-200 families,were involved in the mechanism of childhood asthma,which may regulate E-cadherin expression.These providing a potential therapeutic target or or new direction for the treatment of asthma... |
