Hallmarks of Aging
The Hallmarks of Aging are a set of interconnected biological processes that contribute to the aging of all organisms. Simply put, the Hallmarks of Aging are the root causes of why we age. By targeting the underlying biological processes that contribute to aging, it is possible to slow down or even reverse some of the effects of aging and increase healthspan. There are currently nine Hallmarks of Aging, which are described below:
DNA Stability
This hallmark refers to the accumulation of DNA damage that occurs as a result of various factors, including oxidative stress, exposure to radiation, and errors during DNA replication. The accumulation of mutations and genomic rearrangements can result in genetic defects that contribute to aging and age-related diseases.
Telomere Length
Telomeres are the protective caps on the ends of chromosomes that shorten with each cell division. Telomere attrition is thought to contribute to cellular senescence and ultimately to the aging of tissues and organs. Shortened telomeres can also lead to genomic instability and increased risk of cancer.
Epigenetic Alteration
Epigenetic changes involve modifications to the packaging of DNA, which can affect gene expression and contribute to age-related diseases. These changes can be influenced by environmental factors such as diet and lifestyle choices.
Stem Cell Exhaustion
Stem cells are responsible for repairing and regenerating tissues throughout the body. As stem cells become depleted, tissue repair and regeneration become less effective, leading to age-related decline in tissue and organ function.
Cellular Senescence
Senescent cells are no longer able to divide, but they remain active and can secrete inflammatory molecules that contribute to age-related diseases. The accumulation of senescent cells has been implicated in a variety of age-related diseases including osteoarthritis, atherosclerosis, and cancer.
Protein Balance
Also known as Loss of Proteostasis, this hallmark refers to the failure of cells to maintain proper protein folding and degradation, which can lead to the accumulation of damaged and misfolded proteins. This can contribute to cellular dysfunction, inflammation, and aging, and is implicated in a variety of age-related diseases.
Nutrient Sensing
Nutrient sensing pathways, such as insulin/IGF-1 and mTOR, play important roles in regulating metabolism and aging. Dysregulation of these pathways can contribute to aging and age-related diseases such as obesity, type 2 diabetes, and cancer.
Mitochondrial Function
Mitochondria are the powerhouses of the cell, and their dysfunction can lead to cellular damage and contribute to aging and age-related diseases. Mitochondrial dysfunction can be caused by factors such as oxidative stress, genetic mutations, and environmental toxins.
Cellular Communication
Communication between cells is critical for maintaining tissue homeostasis. Alterations in intercellular communication can contribute to aging and age-related diseases such as Alzheimer's, cancer, and cardiovascular disease. Changes in cell signaling pathways can be caused by a variety of factors including environmental toxins, inflammation, and hormonal imbalances.