title: MicroRNAs and cataracts: correlation among let-7 expression, age and the severity of lens opacity.
abstract: BACKGROUND
  Let-7 microRNA is an important regulator of cellular ageing and tissue senescence. The objective of this study is to evaluate the expression of let-7a/let-7b/let-7c microRNAs in human age-related cataracts.
  
  
  OBJECTIVE
  To evaluate the correlation among the severity of lens opacity, the level of let-7a/let-7b/let-7c microRNA expression and patient age in the context of age-related cataracts.
  
  
  METHODS
  The authors evaluated the mRNA level of let-7a/let-7b/let-7c microRNA in lens epithelia obtained from 174 eyes with age-related cataracts. The authors also recorded the patient age and the severity of lens opacity as classified according to the modified version of the Lens Opacities Classification System version III.
  
  
  RESULTS
  Let-7b microRNA expression was demonstrated to be positively associated with patient age (R=0.472; p<0.001). A positive correlation was also observed between higher N, C and P cataract scores and higher expression of let-7b microRNA in patients with age-related cataracts (p<0.001). However, no significant correlation was observed between the let-7a and let-7c microRNA expression levels and either the severity of lens opacity or the patient age.
  
  
  CONCLUSIONS
  These findings suggest that microRNAs play a role in age-related cataracts. A local let-7b microRNA increase may represent a risk factor in the formation of age-related cataracts.
authors.affiliation: Department of Ophthalmology, Taipei Veterans General Hospital, No.201, Sec. 2, Shih-Pai Rd., Taipei 11217, Taiwan, ROC.
authors.forename: Chi-Hsien
authors.initials: CH
authors.lastname: Peng
authors.forename: Jorn-Hon
authors.initials: JH
authors.lastname: Liu
authors.forename: Lin-Chung
authors.initials: LC
authors.lastname: Woung
authors.forename: Tzu-Jung
authors.initials: TJ
authors.lastname: Lin
authors.forename: Shih-Hwa
authors.initials: SH
authors.lastname: Chiou
authors.forename: Po-Chen
authors.initials: PC
authors.lastname: Tseng
authors.forename: Wen-Yuan
authors.initials: WY
authors.lastname: Du
authors.forename: Cheng-Kuo
authors.initials: CK
authors.lastname: Cheng
authors.forename: Chao-Chien
authors.initials: CC
authors.lastname: Hu
authors.forename: Ke-Hung
authors.initials: KH
authors.lastname: Chien
authors.forename: Shih-Jen
authors.initials: SJ
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D015153:Blotting, Western; D002386:Cataract / Q000235:genetics* / Q000503:physiopathology; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D007908:Lens, Crystalline / Q000378:metabolism*; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D018918:Phacoemulsification; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D012307:Risk Factors
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger; C487931:mirnlet7 microRNA, human