An Update on Microrna's and Metabolic Regulation with Future Therapeutic Potentials Regarding Diagnosis and Treatment of Obesity, Metabolic Syndrome and Other Related Disorders (original) (raw)

2015, An Update on Microrna’s and Metabolic Regulation with Future Therapeutic PotentialsRegarding Diagnosis and Treatment of Obesity, Metabolic Syndrome and Other Related Disorders. J Health Med Informat 6: 184. doi: 10.4172/2157-7420.1000184

https://doi.org/10.4172/2157-7420.1000184

Micro RNAs is a family of highly conserved, single stranded 19- 23 nucleotide long noncoding endogenous RNAs which negatively regulate gene expression, either by inhibiting translation or by degrading largest mRNAs [1]. Over 2000 unique miRNAs have been identified in humans [2] The miRNAs are initially transcribed as long RNA precursors termed primary miRNAs (pri-miRNAs) that require the RNAse III enzyme Drosha in the nucleus to trim them into premiRNAs The premiRNAs are characterized by a stemloop or hairpin structure of 70-100 nucleotides and are exported to the cytoplasm by the nuclear export factor exportin 5. The pre-miRNAs are subsequently cropped to become mature miRNA by another RNAse enzyme Dicer in the cytoplasm [3]. Although our understanding of the specific roles of miRNAs in cellular function is only beginning, recent studies revealed that miRNAs play a pivotal role in the most critical biological events such as development, proliferation, differentiation, apoptosis, transductionand carcinogenesis [4].The mature miRNA’s are conserved about 2 nucleotides noncoding RNAs that anneal to inexactly complementary sequences in the 3’untranslated regions(3’UTR) of target mRNA of protein coding genes, resulting in silencing of the target gene.While the mechanism of action of miRNAs is yet to be fully understood , the widely known mode of gene regulation by miRNAs occurs at the post transcriptional level by either specific inhibition of translation or induction of mRNACleavage [5,6], resulting in a reduction in protein levels of their targets (Figure1) [7]. Alternatively, if the expression of miRNA’s is inhibited, then increased protein expression may be seen in animal species. miRNAs are also capable of modifying chromatin (Figure1) [6]. dsRNA miRNA complex which is composed of the mature miR and its passenger strand (miR”) is unwound by helicase activities of the Argonaute (Ago) multiprotein complex, globally known as the RNA-induced silencing complex (RISC) [8-10]. Determination of the active (guide) strandis based upon simple energetics between strands at the 5’ ends of the dsRNA complex [11]. The preferred guide strand is subsequently incorporated-Furthermore we detailed role of miR in adipose tissue ,obesity,IR,childhood obesity&in adulthood besides role of specific miR'S