Introduction
Heterochromatin and its known role in energy production and management of the cells make it vital in the body, hence mtDNA. Therefore, unlike nuclear DNA, mitochondrial DNA, or mtDNA, is inherited in a maternal mode, and it is duplicated and located within the mitochondrion in virtually all the body’s cells. As for the mtDNA mutations or variations, the correlation between them and neurodegenerative diseases has drawn more attention in recent research. Such diseases as Alzheimer’s, Parkinson’s, and Leigh syndrome indicate a gradual degeneration of neurons and subsequent diminished mental and motor function, as well as the manifestation of many other symptoms. By defining the role of mtDNA in these diseases, people not only have an idea about how these diseases occur but also could find ways to diagnose, prevent, or cure these diseases. Therefore, this article aims to focus on the connection between mtDNA and neurodegenerative diseases, the latest investigations, and their potential for further advancement in the field and management of discs.
Mitochondrial DNA: Structure and Function
Mitochondria, sometimes called the energy factories of the cell, are in charge of creating energy that is necessary for various cellular activities. They do this through oxidative phosphorylation, which is a series of enzymes and protein complexes situated in the inner mitochondrial membrane with their codes from both nuclear and mitochondrial DNA. In the same way that it differs from the nuclear genome, which is a parental blend of both the mother and the father, mtDNA can only be inherited from the mother. This circular DNA measuring 16,569 base pairs contains 37 genes, which code for proteins involved in the synthesis of the components of the respiratory chain and other mitochondrial tRNAs and rRNAs.
The primary reason why mtDNA usually acquires more mutations than nuclear DNA is the fact that mtDNA is iteratively duplicated and is located adjacent to the source of oxidative stress, ROS. These mutations can add up over time and also lead to dysfunctions of the cell, particularly if the cell is in a tissue that has high energy requirements, like the brain tissue. Besides, there is the coexistence of different populations of mtDNA called heteroplasmy that makes its involvement in disease even more complex. The degree of heteroplasmy is capable of impacting the progression and the age of onset of mtDNA-associated disorders, such as neurodegenerative diseases.