title: Transient downregulation of microRNA-206 protects alkali burn injury in mouse cornea by regulating connexin 43.
abstract: OBJECTIVE
  Chemical burn in cornea may cause permanent visual problem or complete blindness. In the present study, we investigated the role of microRNA 206 (miR-206) in relieving chemical burn in mouse cornea.
  
  
  METHODS
  An alkali burn model was established in C57BL/6 mice to induce chemical corneal injury. Within 72 hours, the transient inflammatory responses in alkali-treated corneas were measured by opacity and corneal neovascularization (CNV) levels, and the gene expression profile of miR-206 was measured by quantitative real-time PCR (qPCR). Inhibitory oligonucleotides of miR-206, miR-206-I, were intrastromally injected into alkali-burned corneas. The possible protective effects of down-regulating miR-206 were assessed by both in vivo measurements of inflammatory responses and in vitro histochemical examinations of corneal epithelium sections. The possible binding of miR-206 on its molecular target, connexin43 (Cx43), was assessed by luciferase reporter (LR) and western blot (WB) assays. Cx43 was silenced by siRNA to examine its effect on regulating miR-206 modulation in alkali-burned cornea.
  
  
  RESULTS
  Opacity and CNV levels, along with gene expression of miR-206, were all transiently elevated within 72 hours of alkali-burned mouse cornea. Intrastromal injection of miR-206-I into alkali-burned cornea down-regulated miR-206 and ameliorated inflammatory responses both in vivo and in vitro. LR and WB assays confirmed that Cx43 was directly targeted by miR-206 in mouse cornea. Genetic silencing of Cx43 reversed the protective effect of miR-206 down-regulation in alkali-burned cornea.
  
  
  CONCLUSIONS
  miR-206, associated with Cx43, is a novel molecular modulator in alkali burn in mouse cornea.
authors.affiliation: Department of Ophthalmology, The First Hospital Affiliated to PLA General Hospital 51 Fucheng Road, Haidian District, Beijing 100048, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Ophthalmology, The First Hospital Affiliated to PLA General Hospital 51 Fucheng Road, Haidian District, Beijing 100048, China.
authors.forename: Huanfen
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Department of Ophthalmology, The First Hospital Affiliated to PLA General Hospital 51 Fucheng Road, Haidian District, Beijing 100048, China.
authors.forename: Weiqiang
authors.initials: W
authors.lastname: Tang
authors.affiliation: Department of Ophthalmology, The First Hospital Affiliated to PLA General Hospital 51 Fucheng Road, Haidian District, Beijing 100048, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Department of Ophthalmology, The First Hospital Affiliated to PLA General Hospital 51 Fucheng Road, Haidian District, Beijing 100048, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002057:Burns, Chemical / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D018031:Connexin 43 / Q000235:genetics / Q000378:metabolism*; D003315:Cornea / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D065306:Corneal Injuries / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D016510:Corneal Neovascularization / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D003318:Corneal Opacity / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control; D004195:Disease Models, Animal; D015536:Down-Regulation; D057809:HEK293 Cells; D006801:Humans; D056965:Injections, Intraocular; D007634:Keratitis / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control; D008297:Male; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009841:Oligonucleotides / Q000008:administration & dosage* / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D012972:Sodium Hydroxide; D013997:Time Factors; D014162:Transfection; D014945:Wound Healing
chemical_list: D018031:Connexin 43; C543076:GJA1 protein, mouse; D035683:MicroRNAs; C540669:Mirn206 microRNA, mouse; D009841:Oligonucleotides; D034741:RNA, Small Interfering; D012972:Sodium Hydroxide
keywords: Cornea; Cx43; alkali; miR-206