MiR-146 explained

miR-146
Symbol:	miR-146
Altsymbols:	MIR146
Rfam:	RF00691
Mirbase:	MI0000477
Mirbase Family:	MIPF0000103
Rna Type:	miRNA
Tax Domain:	Mammalia
Go:	0035195
So:	0001244
Entrezgene:	406938
Hgncid:	31533
Omim:	610566
Refseq:	NR_029897
Chromosome:	5
Arm:	q
Band:	34

miR-146 is a family of microRNA precursors found in mammals, including humans. The ~22 nucleotide mature miRNA sequence is excised from the precursor hairpin by the enzyme Dicer.^[1] This sequence then associates with RISC which effects RNA interference.^[2]

miR-146 is primarily involved in the regulation of inflammation^[3] and other process that function in the innate immune system.^[4] Loss of functional miR-146 (and mir-145) could predispose an individual to suffer from chromosome 5q deletion syndrome.^[5] miR-146 has also been reported to be highly upregulated in osteoarthritis cartilage, and could be involved in its pathogenesis.^[6] mir-146 expression is associated with survival in triple negative breast cancer.^[7]

Function

miR-146 is thought to be a mediator of inflammation along with another microRNA, mir-155. The expression of miR-146 is upregulated by inflammatory factors such as interleukin 1 and tumor necrosis factor-alpha.^[8] miR-146 dysregulates a number of targets which are mostly involved in toll-like receptor pathways that bring about a cytokine response as part of the innate immune system. miR-146 operates in a feedback system or "negative regulatory loop"^[9] to finely tune inflammatory responses.

Applications

miR-146 could be used as a biomarker for sepsis.^[10] In addition it was found to be absent from the exosomes of prion infected cells suggesting it could be used as a biomarker for prion infection.^[11] miR-146a could be targeted therapeutically as its depletion has implication in the hyperactive response to infection.^[12]

Further reading

• Okada H, Kohanbash G, Lotze MT . MicroRNAs in immune regulation--opportunities for cancer immunotherapy . The International Journal of Biochemistry & Cell Biology . 42 . 8 . 1256–61 . Aug 2010 . 20144731 . 2889234 . 10.1016/j.biocel.2010.02.002 .
• Jädersten M, Hellström-Lindberg E . New clues to the molecular pathogenesis of myelodysplastic syndromes . Experimental Cell Research . 316 . 8 . 1390–6 . May 2010 . 20211165 . 10.1016/j.yexcr.2010.02.043 .
• Chan EK, Ceribelli A, Satoh M . MicroRNA-146a in autoimmunity and innate immune responses . Annals of the Rheumatic Diseases . 72 . ii90-5 . Apr 2013 . Suppl 2 . 23253933 . 10.1136/annrheumdis-2012-202203 . 35063994 . 7664460 .

See also

• microRNA (miRNA)

Notes and References

1. Ambros V . microRNAs: tiny regulators with great potential . Cell . 107 . 7 . 823–6 . Dec 2001 . 11779458 . 10.1016/S0092-8674(01)00616-X . 14574186 . free .
2. Gregory RI, Chendrimada TP, Cooch N, Shiekhattar R . Human RISC couples microRNA biogenesis and posttranscriptional gene silencing . Cell . 123 . 4 . 631–40 . Nov 2005 . 16271387 . 10.1016/j.cell.2005.10.022 . 16973870 . free .
3. Baechle JJ, Chen N, Winer DA . Chronic inflammation and the hallmarks of aging . . 74 . 101755 . 2023 . 10.1016/j.molmet.2023.101755 . 10359950 . 37329949.
4. Sonkoly E, Ståhle M, Pivarcsi A . MicroRNAs and immunity: novel players in the regulation of normal immune function and inflammation . Seminars in Cancer Biology . 18 . 2 . 131–40 . Apr 2008 . 18291670 . 10.1016/j.semcancer.2008.01.005 .
5. Quinn SR, O'Neill LA . A trio of microRNAs that control Toll-like receptor signalling . . 23 . 7 . 421–5 . Jul 2011 . 21652514 . 10.1093/intimm/dxr034 . free .
6. Yamasaki K, Nakasa T, Miyaki S, Ishikawa M, Deie M, Adachi N, Yasunaga Y, Asahara H, Ochi M . Expression of MicroRNA-146a in osteoarthritis cartilage . Arthritis and Rheumatism . 60 . 4 . 1035–41 . Apr 2009 . 19333945 . 2670476 . 10.1002/art.24404 .
7. Lánczky. András. Nagy. Ádám. Bottai. Giulia. Munkácsy. Gyöngyi. Szabó. András. Santarpia. Libero. Győrffy. Balázs. 2016-12-01. miRpower: a web-tool to validate survival-associated miRNAs utilizing expression data from 2178 breast cancer patients. Breast Cancer Research and Treatment. 160. 3. 439–446. 10.1007/s10549-016-4013-7. 1573-7217. 27744485. 11165696.
8. Sheedy FJ, O'Neill LA . Adding fuel to fire: microRNAs as a new class of mediators of inflammation . Annals of the Rheumatic Diseases . 67 . iii50-5 . Dec 2008 . Suppl 3 . 19022814 . 10.1136/ard.2008.100289 . 20802154 .
9. Ma X, Becker Buscaglia LE, Barker JR, Li Y . MicroRNAs in NF-kappaB signaling . Journal of Molecular Cell Biology . 3 . 3 . 159–66 . Jun 2011 . 21502305 . 3104013 . 10.1093/jmcb/mjr007 .
10. Gîză DE, Vasilescu C . [MicroRNA's role in sepsis and endotoxin tolerance. More players on the stage] . Chirurgia (Bucur.). 105 . 5 . 625–30 . Sep–Oct 2010 . 21141085 .
11. Bellingham SA, Coleman BM, Hill AF . Small RNA deep sequencing reveals a distinct miRNA signature released in exosomes from prion-infected neuronal cells . Nucleic Acids Research . 40 . 21 . 10937–49 . Nov 2012 . 22965126 . 3505968 . 10.1093/nar/gks832 .
12. O'Connell RM, Rao DS, Baltimore D . microRNA regulation of inflammatory responses . Annual Review of Immunology . 30 . 295–312 . 2012 . 22224773 . 10.1146/annurev-immunol-020711-075013 .