Our Powerhouse Gone Awry - Part 1
Dear Longevity Insider,
Mitochondria serve as the powerhouses of our cells for which a delicate balance of energy flow is needed to generate energy production. Mitochondrial function has a substantial impact on the aging process and its dysfunction can accelerate aging.
The biological definition of aging is the many processes of cellular damage accumulation in the body. These are known in the scientific literature as the Nine Hallmarks of Aging. We’ve covered the first four, or primary, hallmarks: genomic instability, telomere attrition, epigenetic alterations, and loss of proteostasis, as well as the first of the antagonistic: deregulated nutrient-sensing.
The role of the antagonistic hallmarks is to respond to and block the damage caused by the primary hallmarks. Yet, when bodily conditions become chronic and/or aggravated, they end up contributing to cellular damage and can accelerate aging. The sixth hallmark, and second of the antagonistic, is mitochondrial dysfunction. It is implicated in numerous age-related pathologies including neurodegenerative and cardiovascular disorders, diabetes, obesity and cancer.
Our source of cellular energy
You may remember from biology class that mitochondria are membrane-bound organelles, or specialized structures, within the cytoplasm our cells. Their main role is to metabolize, or break down carbohydrates and fatty acids, which creates energy-harvesting chemical reactions that result in adenosine triphosphate (ATP), often referred to as the energy currency of our cells. Mitochondria generate over 80% of our ATP through a process called cellular respiration, which requires oxygen. It does this via the oxidation of glucose.
Division, fusion and quality control
Mitochondria are highly dynamic and continually fuse and divide. Many cellular pathways allow this to happen, and these roles are critical, especially when cells encounter stress.
Mitochondrial fission, or division, is crucial to create new mitochondria for growing cells. Fission also contributes to quality control by enabling the removal of damaged mitochondria and can facilitate apoptosis (controlled cell death) during high levels of cellular stress. Mitochondrial fusion helps mitigate stress by mixing the contents of partially damaged mitochondria.
A 2017 research article in the journal, Genes, states that, “The maintenance of mitochondrial and cellular homeostasis requires a tight regulation and coordination between generation of new and removal of damaged mitochondria.” When these mechanisms are disrupted, it affects normal development, which can lead to neurodegenerative diseases.
Mitochondria contain their own DNA (called mtDNA), separate from the rest of the genes in the nucleus of our cells. It is for this reason that some researchers believe that mitochondria evolved from primitive bacteria that developed a symbiotic relationship with our cells over 1.45 billion years ago!
One of the causes of mitochondrial dysfunction is mutations in mtDNA, which occur mostly due to spontaneous errors during the replication process and damage repair. As we age, these mutations have been shown to increase in the human brain, heart, skeletal muscles and liver tissues.
More on Thursday!
To your longevity,
Anil Bajnath MD
CEO/Founder, Institute for Human Optimization
Chief Medical Officer, ABMD Health