Mitochondria - the powerhouses that provide energy for our cells - are of growing significance in aging research. It was recently convincingly demonstrated that mitochondrial mutations lead to age-related degeneration. Biogerontologist Aubrey de Grey has proposed a strategy for dealing with these mutations as a part of his SENS initiative.
As you might recall from Kip Werking's report on TransVision 2004, biologist Rafal Smigrodski has been working on the tools needed to manipulate mitochondrial DNA. Here is one of the first reports on work he assisted:
Many "classic" mitochondrial diseases have been described that arise from single homoplasmic mutations in mitochondrial DNA (mtDNA). These diseases typically affect nonmitotic tissues (brain, retina, muscle), present with variable phenotypes, can appear sporadically, and are untreatable. Evolving evidence implicates mtDNA abnormalities in diseases such as Alzheimer's, Parkinson's, and type II diabetes, but specific causal mutations for these conditions remain to be defined. Understanding the mtDNA genotype-phenotype relationships and developing specific treatment for mtDNA-based diseases is hampered by inability to manipulate the mitochondrial genome. We present a novel protein transduction technology ("protofection") that allows insertion and expression of the human mitochondrial genome into mitochondria of living cells. With protofection, the mitochondrial genotype can be altered, or exogenous genes can be introduced to be expressed and either retained in mitochondria or be directed to other organelles. Protofection also delivers mtDNA in vivo, opening the way to rational development of mitochondrial gene replacement therapy of mtDNA-based diseases.
This is an important step forward - reliable, low cost manipulation or replacement of mitochondrial genes opens the door to all sorts of new strategies aimed at further understanding and intervening in the aging process.