mmu-mir-455: mmu-mir-455 is a microRNA (miRNA) that has been identified in mouse models and is implicated in the regulation of various genes and biological processes [PMC4356433]. Research has shown that mmu-mir-455, when elevated in cardiomyocyte-derived exosomes (CM EXOs), can inhibit the activation of matrix metalloproteinase 9 (MMP9), thereby protecting against fibrosis and myocyte uncoupling in the heart [PMC6406975]. In a study involving mice subjected to destabilization of the medial meniscus (DMM), those injected with mmu-mir-455 agomir exhibited significant alterations in cartilage OARSI grade scores and collagen II content, suggesting a role for mmu-mir-455 in cartilage homeostasis [PMC7658376]. Additionally, mmu-mir-455 was found to be differentially expressed in lung pathology models, indicating its potential involvement in lung disease processes [PMC3030602]. The miRNA has also been associated with regulatory networks involving genes such as motile sperm domain containing 1 (MOSPD1) and reticulon 4 (RTN4), highlighting its role in gene regulation [PMC3742134]. The presence of mmu-mir-455 was first recorded in miRBase v8.1, indicating its recognition as a significant miRNA for further study [PMC3125744]. Quantitative analysis of this miRNA can be performed using specific TaqMan RT-PCR assays, facilitating research into its expression and function [PMC4386824].