Expression data from the rat knee articular cartilage at different developmental stages

Age as the primary rise factor could be play an important role in incidence and development of osteoarthritis. Several studies have confirmed some tissue specific microRNA were associated with development of osteoarthritis. But if age related microRNA or miRNA cluster would be involved in pivotal post-transcriptional gene regulation in osteoarthritis is unclear. In view of this, we have an idea that several age-related miRNAs would be screened from the rat knee cartilage at different development ages by miRNAs Microarray analysis. We used microarrays to detail the global programme of gene expression underlying the rat knee cartilage and identified distinct classes of age-related miRNAs during this process. The rat knee articular cartilage were selected at successive stages of the rat developmental for RNA extraction and hybridization on Affymetrix microarrays. We sought to obtain homogeneous populations of cartilage at each developmental stage in order to increase the temporal resolution of expression profiles. To that end, we hand-selected cartilage according to the rat developmental stages, i.e. seven time-points: newborn (T0), childhood (T1), youth(T2), adult (T3), middle-aged (T4) early-stage elderly(T5) and latter-stage elderly(T6). The objective of the study is to identify miRNA profile of knee articular cartilage at different developmental ages in rats. Total RNA were extracted from the knee articular cartilage of Sprague-Dawley rats at postnatal day 0(T0), week1(T1), week 4(T2), mon3(T3), mon 6(T4), mon 12(T5), and mon 18(T6). The microRNA profile in the specimens was detected with the Affymetrix GeneChip® miRNA 3.0 Array.