title: Transcriptome-wide analysis of messenger RNA decay in normal and osteoarthritic human articular chondrocytes.
abstract: OBJECTIVE
  Messenger RNA (mRNA) decay rates control not only gene expression levels, but also responsiveness to altered transcriptional input. We undertook this study to examine transcriptome-wide posttranscriptional regulation in both normal and osteoarthritic (OA) human articular chondrocytes.
  
  
  METHODS
  Human articular chondrocytes were isolated from normal or OA tissue. Equine articular chondrocytes were isolated from young or old horses at a commercial abattoir. RNA decay was measured across the transcriptome in human cells by microarray analysis following an actinomycin D chase. Messenger RNA levels in samples were confirmed using quantitative reverse transcription-polymerase chain reaction.
  
  
  RESULTS
  Examination of total mRNA expression levels demonstrated significant differences in the expression of transcripts between normal and OA chondrocytes. Interestingly, almost no difference was observed in total mRNA expression between chondrocytes from intact OA cartilage and those from fibrillated OA cartilage. Decay analysis revealed a set of rapidly turned over transcripts associated with transcriptional control and programmed cell death that were common to all chondrocytes and contained binding sites for abundant cartilage microRNAs. Many transcripts exhibited altered mRNA half-lives in human OA chondrocytes compared to normal cells. Specific transcripts whose decay rates were altered were generally less stable in these pathologic cells. Examination of selected genes in chondrocytes from young and old healthy horses did not identify any change in mRNA turnover.
  
  
  CONCLUSIONS
  This is the first investigation into the "posttranscriptome" of the chondrocyte. It identifies a set of short-lived chondrocyte mRNAs likely to be highly responsive to altered transcriptional input as well as mRNAs whose decay rates are affected in OA chondrocytes.
authors.affiliation: University of Liverpool, Leahurst Campus, Neston, Cheshire, UK.
authors.forename: Simon R
authors.initials: SR
authors.lastname: Tew
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: McDermott
authors.forename: Rory B
authors.initials: RB
authors.lastname: Fentem
authors.forename: Mandy J
authors.initials: MJ
authors.lastname: Peffers
authors.forename: Peter D
authors.initials: PD
authors.lastname: Clegg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism; D000818:Animals; D002358:Cartilage, Articular / Q000378:metabolism* / Q000473:pathology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism* / Q000473:pathology; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006736:Horses; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D023421:Models, Animal; D020370:Osteoarthritis, Knee / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology*; D020871:RNA Stability / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism*; D055815:Young Adult
chemical_list: D012333:RNA, Messenger