Extracellular microRNAs and oxidative stress in liver injury: a systematic mini review

Recent evidence has suggested that extracellular microRNAs have crucial roles in intercellular communications and are promising as minimally invasive biomarkers for various diseases including cancers. Oxidative stress also plays an essential role in homeostasis and disease development. This systematic review aims to clarify the current evidence on the interaction between oxidative stress and extracellular microRNAs. We identified 32 studies that provided information regarding the association between oxidative stress and extracellular microRNAs: 9 focused on the central nervous system, 11 focused on cardiovascular diseases, and 4 focused on liver injury. Endothelial cell-specific miR-126-3p was the most studied extracellular miRNA associated with oxidative stress. In addition, we highlight some reports that describe the mechanisms of how oxidative stress affects extracellular microRNA profiles in liver injury. In liver injury, the levels of miR-122-5p, miR-192-5p, miR-223-3p, and miR-1224-5p were reported to be elevated in the sera. The release of miR-122-5p, miR-192-5p, and miR-1224-5p from hepatocytes may be attributed to oxidative stress. miR-223-3p could be released from neutrophils and suppress oxidative stress in the liver. Elucidation of the mechanisms of the interaction between extracellular microRNAs and oxidative stress would improve our pathophysiological understanding as well as future medical practice.