Role of miR-155 and miR-103 in Oxidative Stress in Cardiovascular Disease: A Narrative Review

Background/Objectives: Oxidative stress is a major contributor to the pathogenesis of cardiovascular diseases, including hypertension, ischemic cardiomyopathy, and heart failure. MicroRNAs (miRNAs) have been extensively investigated in various contexts, and some of them have been identified to play a role in cardiovascular disease. This narrative review focuses on miR-103 and miR-155, two miRNAs implicated in the modulation of oxidative stress and cardiovascular remodeling. Methods: The following queries were used in PubMed since inception until May 2026: (("miR-155" OR "microRNA-155" OR miR155) AND ("oxidative stress" OR ROS OR "reactive oxygen species") AND ("cardiovascular disease" OR cardiovascular OR cardiac OR heart OR vascular)); (("miR-103" OR "microRNA-103" OR miR103) AND ("oxidative stress" OR ROS OR "reactive oxygen species") AND ("cardiovascular disease" OR cardiovascular OR cardiac OR heart OR vascular)). Results: A total of seven citations for miR-103 and 79 citations for miR-155 were identified. Reviews and papers about diseases other than those on cardiac/vascular involvement were excluded. miR-155 emerges as a potential regulator of inflammatory-redox signaling, whereas miR-103 appears more closely linked to cell fate and metabolic pathways. In both cases, available evidence supports a context-dependent role that challenges simplistic classification as pro- or antioxidant miRNAs. Conclusions: Available evidence suggests that both miR-103 and miR-155 are important regulators of oxidative stress-related pathways in cardiovascular disease. Nevertheless, the context-dependent effects observed across different cardiovascular disorders raise concerns regarding the safety of systemic miRNA modulation-based therapeutic strategies. Future studies should clarify the determinants of this context-dependent behavior and identify the specific conditions under which these miRNAs exert protective or harmful effects, which might pave the way for the development of miRNA-based therapeutic strategies targeting oxidative stress and cardiovascular remodeling.