They modulate gene function through their binding to complementary regions within the 3'-UTRs of target mRNAs, leading to mRNA degradation or repression of translation.
Subsequent cleavage of pre-miRNA by an RNase III, DICER 1, results in mature miRNA, which suppresses translation and enhances degradation of target gene transcripts by binding to complementary regions within the target transcripts [4], [5].
They play important roles in the regulation of target genes by binding to complementary regions of messenger transcripts and repressing their translation or regulating degradation [ 34, 35].
miRNAs are a class of small, non-coding RNAs, from 19-24 nt in length, that post-transcriptionally regulate gene expression by binding to complementary regions in, primarily, the 3' untranslated region (3' UTR) of target messenger RNAs.
The miRNAs are then incorporated into RNA-induced silencing complexes where they function either to inhibit translation or to mediate the degradation of their target mRNAs commonly by binding to complementary regions in the 3' untranslated regions (UTRs) [ 2- 4].
Mature miRs act by binding to complementary regions of mRNAs, inhibiting translation or by destabilising the gene, resulting in down regulation of their target genes (Bohnsack et al., 2004, Chen and Rajewsky, 2007, Kim, 2005, Lee et al., 2003).
All 31 coding exons of EP300, including splice junctions, were amplified from genomic DNA using primers binding to complementary intronic regions (Table 2).
miRNAs are small noncoding RNAs that can silence target mRNAs by binding to complementary sequences in 3' untranslated regions (3'UTR) to induce target mRNA degradation or translational repression [ 16]. miRNAs have been associated with the collagenases and aggrecanase that are stimulated by IL-1β in OA cartilage degradation [ 17- 19].
miRs are small noncoding RNA molecules that regulate posttranscriptional gene expression by binding to complementary sequences in the specific region of gene mRNAs, resulting in downregulation of gene expression.
They regulate the gene expression by repressing it at a post-transcriptional level by binding to complementary sequences usually at the 3' untranslated regions of target mRNAs [ 20, 21].
In addition to DNA methylation and histone modifications, gene expression is also regulated by microRNAs (miRNA); the small noncoding RNAs that regulate gene expression posttranscriptionally by binding to complementary sequences in the 3′ untranslated regions of messenger RNAs [ 43, 44].
