miR-146

miR-146, also known as microRNA-146, refers to a family of small non-coding RNA molecules, typically around 22 nucleotides in length, that play a regulatory role in gene expression. They are evolutionarily conserved and found in a wide range of organisms, including humans. MicroRNAs, including miR-146, function by binding to messenger RNA (mRNA) molecules, typically in the 3' untranslated region (3'UTR), which can lead to either degradation of the mRNA or repression of its translation into protein.

The miR-146 family primarily consists of two members: miR-146a and miR-146b. These two microRNAs share a highly similar seed sequence (the region most critical for target recognition) but differ slightly in their overall sequence and expression patterns. This allows them to target overlapping but also distinct sets of mRNA transcripts.

Functionally, miR-146 is frequently implicated in the regulation of the immune system and inflammatory responses. It is often described as a negative regulator of these processes. Specifically, miR-146a and miR-146b are known to target genes involved in the NF-κB signaling pathway, a central regulator of inflammation and immunity. By downregulating components of this pathway, such as IRAK1 (interleukin-1 receptor-associated kinase 1) and TRAF6 (TNF receptor-associated factor 6), miR-146 helps to limit excessive inflammatory responses.

Aberrant expression of miR-146 has been linked to various diseases, including autoimmune disorders, cancer, and neurodegenerative diseases. In some cancers, miR-146 can act as a tumor suppressor, inhibiting cell proliferation and metastasis. However, in other contexts, it may promote tumor growth or contribute to drug resistance. Understanding the specific role of miR-146 in different disease states is an active area of research with the potential to identify novel therapeutic targets and biomarkers.