Cell-Based Therapeutic Strategies for Correcting Mitochondrial DNA Mutations and Mitigating Oxidative Stress

Abstract:

Mitochondria are essential structures that produce energy in cells through mitochondrial oxidative phosphorylation and are one of the primary sources of reactive oxygen species (ROS). Mutations in mitochondrial DNA (mtDNA) cause a wide range of hereditary illnesses with multisystem clinical symptoms, poor cellular bioenergetics, and decreased mitochondrial oxidative phosphorylation. Effective treatment approaches have been hampered by the genetic complexity associated with mtDNA disorders, including heteroplasmy and tissue-specific diversity. The relationship between mutations in the mitochondrial DNA and oxidative stress is multidimensional and snowballing, with structural malfunction of the electron transport chain encouraging the development of ROS that causes further damage to mitochondrial DNA, lipids, and proteins. Under carefully regulated experimental conditions, cell-based disease models, in particular induced pluripotent stem cells (iPSCs) and standard transmitochondrial cybrids, have become useful tools for studying disease mechanisms, simulating mutation-specific phenotypes, and assessing possible therapeutic interventions. This review provides the key roles of mutations and oxidative stress in the pathogenesis of the disease in the context of the primary role of the mitochondrial genome, its maternal inheritance, and the most common disorders, i.e., mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) and myoclonic epilepsy with ragged red fibers (MERRF). We outline the use of cell-based models to study mitochondrial pathologies, including patient-derived primary cells and iPSCs, which could be differentiated into cell types of interest to the disease, and cybrid systems, which could isolate the contribution of single mutations in the mitochondrial DNA to an underlying background of controlled nuclear genetic backgrounds. Besides, the review focuses on innovative technologies to mend mutations in mitochondrial DNA, such as allotopic expression, mitoTALENs and mitoZFNs, and the new base-editing systems like DdCBEs. Included are the free cell-based therapies like mitochondrial transfer and nuclear transfer procedures. Finally, we discussed the measures to be taken to minimize oxidative stress, and these actions are standard: mitochondria- targeted antioxidants, mitophagy, and autophagy regulation. The study also looks at the present level of proof supporting these therapy techniques and discusses the advantages and disadvantages of existing experimental models. Although several gene editing and mitochondria replacement technologies have shown promising results in clinical and cellular research, their clinical translation is still restricted and needs more confirmation in terms of long-term therapeutic efficacy, safety, and delivery efficiency.