title: MicroRNA-328 may influence myopia development by mediating the PAX6 gene.
abstract: OBJECTIVE
  We showed previously that single nucleotide polymorphism (SNP) rs662702 in PAX6 may be located in a microRNA-328 binding site that causes susceptibility to high myopia. Our study was done to elucidate the role of PAX6 and its relationship with microRNA-328 in myopia.
  
  
  METHODS
  A luciferase assay was used to confirm microRNA-328 binding to the PAX6 locus. Clones containing each allele of rs662702 were created and tested for their binding affinity to microRNA-328. Because a low level of PAX6 is a risk factor for myopia, we tested whether knockdown of PAX6 affects retinal pigment epithelial (RPE) cells and scleral cells, as well as expression of myopia-related genes. We also tested for the effect of retinoic acid (RA) on microRNA-328 expression, since RA-responsive elements are predicted to lie in the microRNA-328 promoter.
  
  
  RESULTS
  MicroRNA-328 was shown to bind to the wild-type, but not mutant 3' untranslated region (UTR) of PAX6. The risk C allele of rs644242 had strong response to microRNA-328 but the protective T allele did not respond to microRNA-328. Down-regulation of PAX6 in RPE increased RPE proliferation, but reduced scleral cell proliferation. In addition, transforming growth factor (TGF)-β3 in the RPE and matrix malleoproteinase-2 (MMP2) in the sclera were increased, while collagen I and integrin β1 in the sclera were decreased. RA dose-dependently increased microRNA-328 expression and, in turn, suppressed PAX6 expression.
  
  
  CONCLUSIONS
  We elaborated the relationship among myopia development, SNP rs662702, microRNA-328 and RA. The data imply that reduction of miR-328 and/or RA can be potential strategies for myopia prevention or treatment.
authors.affiliation: Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: Ku-Chung
authors.initials: KC
authors.lastname: Chen
authors.forename: Edward
authors.initials: E
authors.lastname: Hsi
authors.forename: Ching-Yu
authors.initials: CY
authors.lastname: Hu
authors.forename: Wen-Wen
authors.initials: WW
authors.lastname: Chou
authors.forename: Chung-Ling
authors.initials: CL
authors.lastname: Liang
authors.forename: Suh-Hang Hank
authors.initials: SH
authors.lastname: Juo
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D018450:Disease Progression; D015536:Down-Regulation; D005136:Eye Proteins / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D017403:In Situ Hybridization; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D009216:Myopia / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000378:metabolism; D012313:RNA / Q000096:biosynthesis / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D012097:Repressor Proteins / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000378:metabolism / Q000473:pathology; D012590:Sclera / Q000378:metabolism / Q000473:pathology
chemical_list: D005136:Eye Proteins; D018398:Homeodomain Proteins; C548170:MIRN328 microRNA, human; D035683:MicroRNAs; D000071841:PAX6 Transcription Factor; C000605730:PAX6 protein, human; D051761:Paired Box Transcription Factors; C000605732:Pax6 protein, mouse; D012097:Repressor Proteins; D012313:RNA