In today's article we are going to explore the exciting world of Mir-199 microRNA precursor, a topic that has captured the attention of millions of people around the world. From its origins to its relevance today, Mir-199 microRNA precursor has generated debate, interest and curiosity in various areas of society. Throughout this article, we will analyze the importance of Mir-199 microRNA precursor in the current context, as well as its influence on different aspects of daily life. In addition, we will delve into its historical, cultural and social implications, offering a detailed perspective that will allow us to better understand the relevance of Mir-199 microRNA precursor in today's world.
The miR-199 microRNA precursor is a short non-coding RNA
gene involved in gene regulation.
miR-199 genes have now been predicted or experimentally confirmed in mouse, human and a further 21 other species.[1][2][3][4]microRNAs are transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give a ~22 nucleotide product. The mature products are thought to have regulatory roles through complementarity to mRNA.[5]
Origin and evolution of miR-199
miR-199 has been shown to be a vertebrate specific miR family that emerge at the origin of the vertebrate lineage.[6] Three paralogs of miR-199 can usually be found in non-teleost vertebrate species and 4 to 5 copies in the teleost species. All miR-199 genes are located on opposite strand of orthologous intron of Dynamin genes. Within Dynamin3 gene (Dnm3), miR-199 is associated with miR-214 and both miRs are transcribed together as a common primary transcript, demonstrated in mouse, human and zebrafish.[7]
Targets and expression of miR-199
miR-199 has been shown to be implicated in a wide variety of cellular and developmental mechanisms such as various cancer development and progression, cardiomyocytes protection or skeletal formation.[8]
Using microarray and immunoblotting analyses it has been shown that miR-199a* targets the Met proto-oncogene.[9]
MicroRNA hsa-miR-199a is a regulator of IκB kinase-β (IKKβ) expression.[10]
Using TaqMan real-time quantitative PCR array methods, miRNA expression has been profiled. miR-199a, one of the most significantly overexpressed in invasive squamous cell carcinomas (ISCCs), was evaluated by transfecting cervical cancer cells (SiHa and ME-180) with anti-miR-199a oligonucleotides and the cell viability assessed.
mirR-199a*, mir199a and mirR-199b were significantly overexpressed in ISCCs.[11]
Implication of miR-199 in skeletogenesis
miR-199, along with its cluster mate MiR-214, has been shown to be implicated in skeleton formation. In mice, miR-199 is expressed in perichondrial cells, periarticular chondrocytes, tracheal cartilage, limb mesenchyme, and most tissues in the upper and lower jaw.[7] In zebrafish, miR-199 is expressed in the developing notochord and in all tissues surrounding developing skeletal elements.[6] Comparative miRNA array led to the isolation of several Bone Morphogenic Protein 2 (BMP2)-responsive miRNAs. Among them, miR-199a* is of particular interest, because it was reported to be specifically expressed in the skeletal system and was shown to inhibit chondrogenesis by down-regulation of Smad1, a major regulator of bone and cartilage formation and development.[12] Also, Twist-1, which is a major actor in skeleton formation, regulates miR-199 and miR-214 cluster expression in mouse.[13] Furthermore, miR199-214 cluster deletion in mouse lead to skeletal development abnormalities including craniofacial defects, neural arch and spinous processes malformations, and osteopenia.[14]
Clinical relevance of miR-199
Alcoholic liver disease is a common medical consequence of long-term excessive alcohol use. Activation of hypoxia-Inducible Factor-1α (HIF-1α) is an indicator of hypoxia. Endothelin-1 (ET-1) is a protein that constricts blood vessels and raises blood pressure. It has been shown that ethanol-induced miR-199 down-regulation may contribute to augmented HIF-1α and ET-1 expression.[15]
^ abDesvignes, T; Postlethwait JH. 2013. Evolution of the miR199-214 cluster and vertebrate skeletal development. Submitted to RNA Biology.[verification needed]
^ abLoebel DA, Tsoi B, Wong N, Tam PP (June 2005). "A conserved noncoding intronic transcript at the mouse Dnm3 locus". Genomics. 85 (6): 782–9. doi:10.1016/j.ygeno.2005.02.001. PMID15885504.
Zhang GL, Li YX, Zheng SQ, Liu M, Li X, Tang H (November 2010). "Suppression of hepatitis B virus replication by microRNA-199a-3p and microRNA-210". Antiviral Research. 88 (2): 169–75. doi:10.1016/j.antiviral.2010.08.008. PMID20728471.