Healthy Foot Blog/Foot & Ankle Health/Unveiling the Hidden Impact: How Aging Adult Stem Cells can Damage Tissues

Unveiling the Hidden Impact: How Aging Adult Stem Cells can Damage Tissues

Saturday, January 20, 2024

As we age, adult stem cells, which are vital for repairing and maintaining tissues, undergo various changes that can lead to tissue damage. This process is a complex interplay of intrinsic and extrinsic factors. Here are some key aspects of how aging affects adult stem cells and leads to tissue damage:

Reduced Regenerative Capacity: One of the most prominent effects of aging on adult stem cells is a decline in their regenerative abilities. This means they are less efficient in repairing and replacing damaged cells, leading to a gradual accumulation of wear and tear in tissues. In fact, as early as age 30 you have already lost 65% of the functioning adult stem cells.

DNA Damage and Mutations: Over time, adult stem cells accumulate DNA damage and mutations. This damage can impair their function and even lead to the development of cancerous cells if the damage affects oncogenes or tumor suppressor genes. As they lose their function, an adult stem cell can't even repair itself.

Cellular Senescence: As with many other cells in the body, aging can cause adult stem cells to enter a state called senescence, where they stop dividing but do not die. Senescent cells can release inflammatory factors that damage surrounding tissues and impair the function of nearby healthy cells.

Stem Cell Niche Alterations: The microenvironment or "niche" where stem cells reside undergoes changes with age. These changes can affect the signals stem cells receive from their environment, impacting their ability to function properly.

Epigenetic Changes: Due to a change in cellular proliferation needs (you're not growing any more), as stem cells age, they experience alterations in epigenetic markers, which can change gene expression patterns. These epigenetic changes can impair the cells' ability to respond to damage or stress appropriately.

Reduced Responsiveness to Signals: Aging stem cells often show reduced responsiveness to growth factors and other signals that are essential for their activation and proper function. This often happens because certain portions of DNA are deactivated with age. This can also lead to impaired tissue repair and regeneration.

Exhaustion of Stem Cell Pools: In some tissues, the pool of stem cells diminishes with age, leading to a reduced capacity for tissue repair. This depletion can be due to a combination of reduced cell division, increased cell death, and conversion to senescent cells.

Loss of Normal Tissues: With age, there's a tendency to loss elasticity of the tissues, increase fibrotic activity (where scar tissues replace normal tissues) both secondary to impared function of stem cells in the body.

Systemic Factors: Age-related changes in the immune system, hormonal levels, and circulation can also impact the function of adult stem cells, further contributing to decreased tissue repair and regeneration.

Mitochondrial Dysfunction: Mitochondria, the energy-producing organelles in cells, tend to function less efficiently in older stem cells, contributing to decreased cell vitality and regenerative capacity.

Understanding these changes is crucial for developing strategies to mitigate the effects of aging on stem cells and, by extension, on tissue health. Research in this area includes exploring ways to rejuvenate stem cells or enhance their function in older individuals, potentially leading to improved health and longevity.