Mitochondria are extremely active organelles that perform a variety of roles in the cell
including energy production, regulation of calcium homeostasis, apoptosis, and population maintenance
through fission and fusion. Mitochondrial dysfunction in the form of oxidative stress and mutations
can contribute to the pathogenesis of various neurodegenerative diseases such as Parkinson’s (PD),
Alzheimer’s (AD), and Huntington’s diseases (HD). Abnormalities of Complex I function in the
electron transport chain have been implicated in some neurodegenerative diseases, inhibiting ATP
production and generating reactive oxygen species that can cause major damage to mitochondria.
Mutations in both nuclear and mitochondrial DNA can contribute to neurodegenerative disease, although the pathogenesis
of these conditions tends to focus on nuclear mutations. In PD, nuclear genome mutations in the PINK1 and parkin genes
have been implicated in neurodegeneration , while mutations in APP, PSEN1 and PSEN2 have been implicated in a
variety of clinical symptoms of AD . Mutant htt protein is known to cause HD . Much progress has been made to
determine some causes of these neurodegenerative diseases, though permanent treatments have yet to be developed. In
this review, we discuss the roles of mitochondrial dysfunction in the pathogenesis of these diseases.