MicroRNAs (miRNAs) are family of small, noncoding RNAs that regulate
gene expression in sequence specific manner. Their non perfect pairing of 6-8
nucleotides with target mRNA subsequently forming miRNA Induced Silencing
Complex (miRISC) generally results in translational repression, destabilization of
mRNAs and gene silencing. miRNAs are transcribed as long primary transcripts (primiRNAs),
which are processed in the nucleus to give one or more hairpin precursor
sequences (pre-miRNAs). The hairpin precursor is exported to the cytoplasm where the
mature miRNA is excised by the RNase III-like enzyme named Dicer. The human
genome may encode over 1500 miRNAs (1527 listed in miRBase), which may target
about 60 percent of mammalian genes and are abundant in many human cell types.
Owing to their significant role in regulation of cellular events including the cellular
proliferation and differentiation during tumorigenesis, organ development, cell fate
determination and apoptotic pathways of various organisms, miRNAs have engrossed
huge attention lately in relation to their role in several diseases including infectious,
cardiovascular and neurological disorders alongwith cancer, diabetes and obesity.
miRNAs facilitate profound functional consequences of signaling pathway involved in
the development of diabetes, insulin resistance and obesity that offers novel ways of
identification and validation of new targets of therapeutic intervention. Although, the
understanding of their complex mechanism of gene regulation and expression is in
infancy, analysis of differential miRNA expression holds a promise to add many
clinical chapters in the treatise of ‘prognosis, diagnosis and therapeutics’ of diabetes.
Keywords: Adipose, beta cells, gene expression, gene repression, gene silencing,
Insulin, insulin action, insulin production, insulin secretion, liver, microRNA,
miRNA biogenesis, miRISC, miRNA targets, non-coding RNA, pre-miRNA, primiRNA,
skeletal tissue, type2 diabetes, therapeutic strategies.