Molecular Mechanisms of Oxidative Stress in Mitochondrial Dysfunction

Mitochondrial dysfunction is a hallmark of various age-related diseases, neurodegenerative disorders, and metabolic conditions, and is closely linked to oxidative stress. Mitochondria are both the primary sources and targets of reactive oxygen species (ROS), which are byproducts of normal mitochondrial respiration. When oxidative stress exceeds the cell’s antioxidant defense capacity, it leads to cellular damage, impaired mitochondrial function, and the initiation of pathophysiological cascades that contribute to disease progression. This review examines the molecular mechanisms underlying oxidative stress in the context of mitochondrial dysfunction, focusing on how ROS production in the mitochondria can drive cellular injury and accelerate the development of mitochondrial-related diseases. We discuss the sources of ROS within mitochondria, particularly the electron transport chain and the role of complex I and III in generating superoxide and hydrogen peroxide. Additionally, we explore how mitochondrial DNA (mtDNA) damage caused by ROS leads to impaired mitochondrial biogenesis, dysfunctional oxidative phosphorylation, and reduced ATP production, which contribute to cellular energy depletion and apoptotic cell death. The review also highlights the interplay between oxidative stress and mitochondrial autophagy (mitophagy), a process crucial for the turnover of damaged mitochondria, and how defects in mitophagy exacerbate mitochondrial dysfunction and disease. Furthermore, we address the role of oxidative stress in diseases such as Parkinson’s disease, Alzheimer’s disease, and cardiovascular disorders, where mitochondrial dysfunction plays a critical role in disease pathogenesis. Finally, the review explores therapeutic approaches to mitigate oxidative stress and restore mitochondrial function, including the use of antioxidants, mitochondrial-targeted drugs, and gene therapy. Understanding the molecular relationship between oxidative stress and mitochondrial dysfunction provides valuable insights into potential interventions for the treatment of mitochondrial diseases and aging-related disorders.