MiR-146

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
Conserved secondary structure of miR-146 microRNA precursor
Identifiers
Symbol	miR-146
Alt. Symbols	MIR146
Rfam	RF00691
miRBase	MI0000477
miRBase family	MIPF0000103
NCBI Gene	406938
HGNC	31533
OMIM	610566
RefSeq	NR_029897
Other data
RNA type	miRNA
Domain	Mammalia
GO	0035195
SO	0001244
Locus	Chr. 5 q34
PDB structures	PDBe

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.^[4][8] miR-146 operates in a feedback system or "negative regulatory loop"^[9] to finely tune inflammatory responses.^[5]

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]