Different responses to mechanical injury in neonatal and adult ovine articular cartilage / 中华风湿病学杂志

ABSTRACT

ObjectiveTo investigate the molecular response of adult and neonate ovine articular cartilage to acute mechanical injury.MethodsAn established in vitro model was used to compare gene expression difference of ovine articular cartilage explants at different developmental stages 24 hours after mechanical injury and the gene expression was compared between these models and that of the uninjured controls by microarray analysis.Total RNA was isolated from the tissue samples,linearly amplified,and applied to a 15 208 Ovine probes cDNA microarray(Agilent).Validation for selected genes(PPARγ,GRO TNC and LDHA) was obtained by real-time polymerase chain reaction.Comparisons between groups were performed by variance analysis.ResultsThere was significant difference in gene expression in adult and neonatal ovine articular cartilage after mechanical injury.Eighty-six genes were significantly manipulated at least 2-fold following mechanical injury for neonate sheep and 83 genes for adult sheep (P＜0.05).Conclusion Our findings indicate that mechanical injury to adult and neonatal ovine articular cartilage results in the activation of a series of signaling responses.We could identify four significant genes that are up or downregulated in response to acute mechanical injury.Significant functional clusters including genes associated with wound healing,articular protection,repair integration,and energy metabolism.Of these,PPARG could be specifically identified as novel target molecules and potential chondroprotective agent involved in traumatic cartilage injury and cartilage integrated repair.