Mir22, an endogenous microRNA, is involved in post-transcriptional regulation of gene expression, playing a role in diverse biological processes. Its dysregulation is associated with various diseases. It participates in epigenetic pathways and is part of gene regulatory axes, highlighting its biological importance [1,2]. Genetic models, such as gene knockout mice, are valuable for studying Mir22's functions.

In a study on rheumatoid arthritis (RA), Mir22-/-mice were used to establish a collagen antibody-induced arthritis (CAIA) model. Results showed that MIR22 inhibits inflammation in fibroblast-like synoviocytes (FLSs) of RA patients by directly inhibiting the translation of TET3, which in turn affects the pro-inflammatory effect on MTRNR2L2 through 5-hydroxymethylcytosine production. This reveals the key role of the MIR22-TET3-MTRNR2L2 pathway in RA-FLSs [1]. In another study, in a mouse model of dopaminergic neuron-related disease, dysregulation of the SATB1-MIR22-GBA axis led to glucocerebroside accumulation, causing a cellular senescence-like phenotype in dopaminergic neurons [2].

In conclusion, Mir22 is crucial in regulating gene expression and has a significant impact on biological processes related to diseases like rheumatoid arthritis and Parkinson's disease-related dopaminergic neuron phenotypes. Gene knockout mouse models have been instrumental in uncovering these functions, providing insights into disease pathogenesis and potential therapeutic targets.

References:

1. Fang, Yilong, Huang, Wei, Zhu, Xiangling, Tu, Jiajie, Zhu, Chen. 2024. Epigenetic Regulatory Axis MIR22-TET3-MTRNR2L2 Represses Fibroblast-Like Synoviocyte-Mediated Inflammation in Rheumatoid Arthritis. In Arthritis & rheumatology (Hoboken, N.J.), 76, 845-856. doi:10.1002/art.42795. https://pubmed.ncbi.nlm.nih.gov/38221658/

2. Russo, Taylor, Kolisnyk, Benjamin, B S, Aswathy, Studer, Lorenz, Riessland, Markus. 2024. The SATB1-MIR22-GBA axis mediates glucocerebroside accumulation inducing a cellular senescence-like phenotype in dopaminergic neurons. In Aging cell, 23, e14077. doi:10.1111/acel.14077. https://pubmed.ncbi.nlm.nih.gov/38303548/