Mitochondria are the power plants of the cell. Although long-studied, the molecular processes of mitochondrial function are still not well understood. Mitochondria have recently gained recognition for their essential role in longevity and health, which has encouraged scientists to view them as vital targets for therapeutic intervention.
A recent paper by researchers at Newcastle University, which appeared in the EMBO journal, reported, for the first time, that there is now proof that mitochondria are essential for cell aging.
Mitochondria are sub-cellular structures, called organelles, which are found in almost all human cells. They are responsible for oxygen-dependent metabolism, which leads to energy production in the form of adenosine triphosphate (ATP). Additionally, they play a role in metabolic processes such as the oxidation of fatty acids; amino acid metabolism; apoptosis or cellular suicide; signal transduction (transmission of molecular signals from outside the cell to the inside); and autophagy, otherwise known as mitophagy, which means literally to eat oneself (which generally occurs if there's been any damage or stress to the mitochondria).
The respiratory chain (RC) is the area of the mitochondria where the chemical energy for cells (ATP) is generated, and decreasing the RC function is associated with aging. The aging process, at the level of cells, accumulate various types of damage that increase factors associated with inflammation, until they die or enter senescence (no longer replicate but remain metabolically active).
By inducing autophagy, the research team effectively eliminated all the mitochondria from within the cells they studied. They subsequently observed that the population of older cells displayed more youthful characteristics once their mitochondria was gone such as reduced levels of inflammatory molecules, oxygen-free radicals and expression of age-related genes all the conditions observed in younger cells.
Dr. Joao Passos of the Institute for Ageing (U.K. spelling), and lead investigator of the study said, This is a very exciting and surprising discovery. We already had some clues that mitochondria played a role in the ageing of cells, but scientists around the world have struggled to understand exactly how and to what extent these were involved. Continuing, Dr. Joao said, These new findings highlight that mitochondria are actually essential to the ageing of cells.
Prior to this study, it was recognized that mitochondria were involved with regulation of lifespan, however, when damage had occurred to the mitochondria, it increased the lifespan of the cells. This had confounded researchers in the past because ageing had been associated with a decline in mitochondrial function. And now we know that it is the mitochondria themselves, that are essential for aging.
The results of this study will hopefully provide future therapeutic value to counteract the ageing of cells utilizing mitochondria as a target.