| Myopia is already a world-wild health problem.It is said that nearly half of the world’s population will have myopia and nearly one-tenth of the world’ s population will have high myopia(myopia worse than-6.00D)by the year 2050.Myopia is already a major public health concern in many countries in East and South-East Asia,where the prevalence of myopia has rapidly incread over the past few decades with nearly 80-90%of high school graduates having myopia and 10-20%having sight-threatening high myopia.Elsewhere in the world,as in North American,Europe and the Middle East,myopia is also on the rise,albeit slower compared with the prevalence in Asia.Although easily correctable with spectacles,contact lenses or refractive surgery,uncorrected refractive errors of which myopia is the most common still remain a major cause of visual impairment due to the lack of screening and availability and affordability of refractive correction.In addition,progressive myopia is associated with increased risks of retinal detachment,cataracts,glaucoma and even blindness.Effective preventions and treatments of myopia should be based on a full understanding of its pathogenesis.However,although many scholars around the world have done a lot of research over the last decades,myopia’ s specific pathogenesis is still unknown.Generally speaking,there are two ways playing the main roles in form derivation myopia(FDM),namely "scleral remodeling mechanism,and "local retinal mechanism".Both of which consider external stimulations to retina to be the starting,then followed by the retina retinal pigment epithelium choroid signal transduction system and local retinal stimulation signal transformation for signal transduction in scleral remodeling,resulting in abnormal expression induced by extracellular matrix and scleral collagenous fibres changes in scleral remodeling.Finally,the mismatch of axial length and refractive ocurres which results in myopia,visual hypofunction and various complications at last.It is found that miRNAs play an important role in signal transduction and regulation in the process of scleral active remodeling.Micro-RNAs are small non-coding single-stranded RNAs,which serve as key regulators of gene expression at the post-transcriptional level.This regulation is achieved through base pairing with the 3’untranslated region(UTR)of their target mRNAs,resulting in cleaving and degradation of the mRNAs,either by virtue of perfect or nearly perfect pairing(as seen in plants),or by translational repression resulting from imperfect pairing(as seen in mammals).Micro-RNAs may thus serve as nodes in signaling networks,modulating via gene expression changes,many cell activities including cell proliferation,differentiation,metabolism and apoptosis.The potential influence of micro-RNAs already discovered in humans,with roles in both normal and disease states.Micro-RNAs transcriptomes have also already been described for some ocular tissues,including the retina,lens,and cornea,although the roles of ocular micro-RNAs in normal and disease states remain largely unknown,with a few exceptions.It is now recognized that they play crucial roles in normal physiological and pathologic processes,both in nonocular and in ocular tissues.Previous studies that focused on the human ocular sclera implicated miRNAs in normal ocular growth(axial elongation),with samples from very young,rapidly growing eyes,showing differential expression compared to those from adult(assumed)stable eyes.Some of the differentially expressed miRNAs could be linked to extracellular matrix remodeling pathways,making them potential targets for preventing or slowing the progression of myopia,which is largely a product of active scleral extracellular remodeling and thinning.As the first step in exploring the potential of miRNAs as therapeutic targets for myopia control,this study sought to understand their role in the scleral changes underlying myopia.We hypothesized that myopia development,when ocular axial elongation("growth")is exaggerated,is directly linked to differential regulation of scleral miRNAs.In this study,we downloaded miRNA microarray data of the complete good pairing form deprivation myopia(FDM)rat model from the known gene expression database to be the research object.Bioinformatics methods were used to explore the potential important miRNAs highly correlated with form deprivation myopia(FDM),as well as the related genes with the miRNAs through miRDB online tools and predicting the prossible function of miRNAs through DAVID database.The aim of the study is to find out the potential important miRNAs in the regulation of the development and progression of FDM in rats,and to predict its function by bioinformatics methods,which can give us the objectives and directions for the further experimental studies.his study will analyze the biological functions of miRNAs associated with form deprivation myopia(FDM)from the following three parts:Part ⅠBioinformatics analysis of miRNAs in form deprivation myopiaObjective:To explore and search for miRNAs related to the formation of form deprivation myopia(FDM).Methods:The complete data of form deprivation myopia(FDM)expression in model miRNA chip(GSE58124),which was reasonable designed,was selected and downloaded from the public microarray database(Gene Expression Omnibus,GEO).The data included miRNA chips of the whole eye tissue,scleral tissue and retinal tissue respectively.All the right eyes are in the experimental group,on contrast all the left eyes are in the control group.In the total 24 samples,there are 6 normal whole eye tissue compared with 6 form deprivation myopia(FDM)whole tissue,3 normal scleral tissue compared with 3 form deprivation myopia(FDM)scleral tissue and 3 normal retinal tissue compared with 3 deprivation myopia(FDM)retinal tissue.After data preprocessing,the median method was used to standardize the inter chip,and then the normalized matrix of a single data matrix was obtained.In order to screen in form deprivation myopia(FDM)for miRNAs which have significant differences(up or down)with the control groups in retinal tissue,whole eye tissue and the scleral tissue,the three experimental groups were matched with the control groups and the data was analyzed respectively,taking the |logFC(FC,fold change)>1| and p<0.05 as the criteria.The aim was to find out the miRNAs highly correlated with form deprivation myopia(FDM).Results:After data processing and analysis,24 significant different miRNAs were obtained in retinal tissue(all up-regulated),while 20 significant different miRNAs in whole eye tissue(all up-regulated),no significant different miRNAs in scleral tissue.Among the 24 miRNAs in retinal tissue and the 20 miRNAs in whole eye tissue,8 miRNAs were common,while were significantly increased in the retina and the whole eye tissue.Conclusions:There are at least 8 potential important miRNAs(mmu-miR-468,mmu-miR-16-1*mmu-miR-466h-5p,mmu-miR-466j,mmu-miR-669e,mmu-miR-15a*,mmu-miR-466c-5p-v15.0 and mmu-miR-294)involved in the regulation of form deprivation myopia(FDM)forming process.Part ⅡPrediction of miRNA target genes associated with form deprivation myopiaObjective:To predict the downstream target genes of the 8 differentially expressed miRNAs.Methods:The online database software miRDB(miRNA target prediction and functional annotations)was investigated to predict the target genes of 8 differentially expressed miRNAs.Results:After retrieval of miRDB online database,a total of 1805 predicted target genes of the 8 different expressed miRNAs were investigated,2 of which were regulated by 5 miRNAs,while 5 of which were regulated by 4 miRNAs,82 of which were regulated by 3 miRNAs simultaneously.A total of 89 rmiRNAs were regulated by at least three of the 8 common miRNAs.Conclusions:There were 7 target genes regulated by 4 of the 8 common different miRNAs simultaneously,including REEP3,MAPK10,INO80D,D630045J12RIK,FMR1,ARMC8 and BACH2,which may be involved in the regulation of form deprivation myopia(FDM)as the main genes.Part IIIFunctional prediction of miRNAs in form deprivation myopiaObjective:To predict the function of 8 common differentially expressed miRNAs.Methods:Functional enrichment analysis was used to investigate the function of 8 common differentially expressed miRNAs by studying the prediction of miRNA target genes using online database software DAVID(The Database for Annotation Visualization and Integrated Discovery).Results:The target genes of 8 common different miRNAs pathway enrichment analysis showed that at the cellular pathways level,5 miRNAs’ target genes were enriched in the mmu04360:Axon guidance pathway(mmu-miR-16-1*,mmu-miR-294,mmu-miR-466c-5p,mmu-miR-466j and mmu-miR-468),4 miRNAs’ target genes were enriched in mmu04350:TGF-beta signaling pathway(mmu-miR-16-1*,mmu-miR-466j,mmu-miR-669e and mmu-miR-294).On the gene ontology level,GO:0045449-regulation of transcription was enriched by 7 miRNAs’ target genes,while other 4 GO BP entries(GO:0006350～transcription/GO:0006355～regulation of transcription,of RNA metabolic,the target gene DNA-dependent/GO:0051252～regulation process)were enriched by 6 miRNAs’ target genes.The target genes of mmu-miR-466h-5p and mmu-miR-466j had a lot of common enrichment to the GO BP entry,indicating the functional coordination between the two miRNAs.Mmu-miR-294,mmu-miR-16-1*,mmu-miR-669e and mmu-miR-466c-5p also had functional collaboration.Conclusions:8 differentially expressed miRNAs may play an important role in the development of myopia by interfering with the regulation of target genes and interfering with multiple cellular pathways and biological processes.Conclusions1.MiRNAs may not play any important roles in the formation of sclera tissue in form deprivation myopia(FDM)mice.2.8 common significantly up-regulated miRNAs(mmu-miR-468,mmu-miR-16-1*,mmu-miR-466h-5p,mmu-miR-466j,mmu-miR-669e,mmu-miR-15a*5 mmu-miR-466c-5p-v15.0 and mmu-miR-294)were found in the study of whole eye tissue and retinal tissue were.3.MiRNAs are involved in the development of form deprivation myopia(FDIM)by regulating target genes such as REEP3,MAPK10,INO80D,D630045J12RIK,FMR1,ARMC8 and BACH2.4.The miRNA target gene function analysis revealed that "regulation of transcription" was significantly enriched.The pathways "axon guidance"and "TGF-beta signaling pathway" were also enriched.Importantly,mir-466h-5p and mir-466j were significantly enriched in some synaptic transmission-related biological processes. |
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