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Cellular Senescence: Difference between revisions
→Exponential Increase and Subsequent Decline
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The senescent state is typically characterized by a halt in cell division, resistance to apoptosis (cell death), and often the secretion of a mix of bioactive molecules known as the senescence-associated secretory phenotype (SASP). The SASP can have both beneficial and detrimental effects, depending on the context. | The senescent state is typically characterized by a halt in cell division, resistance to apoptosis (cell death), and often the secretion of a mix of bioactive molecules known as the senescence-associated secretory phenotype (SASP). The SASP can have both beneficial and detrimental effects, depending on the context. | ||
== | ==Accumulation with Age == | ||
Senescent cells exhibit a unique pattern of accumulation in the human body, marked by an exponential rise during mid-life followed by a | Senescent cells exhibit a unique pattern of accumulation in the human body, marked by an exponential rise during mid-life followed by a reduced growth rate in advanced age. Understanding this pattern offers insights into aging processes and potential interventions. | ||
During early to mid-life, several factors contribute to the exponential accumulation of senescent cells: | During early to mid-life, several factors contribute to the exponential accumulation of senescent cells: | ||
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# '''Environmental and Lifestyle Factors''': Repeated exposure to stressors like ultraviolet radiation, toxins, or an unhealthy lifestyle can further accelerate the accumulation of senescent cells during these years. | # '''Environmental and Lifestyle Factors''': Repeated exposure to stressors like ultraviolet radiation, toxins, or an unhealthy lifestyle can further accelerate the accumulation of senescent cells during these years. | ||
Contrary to the intuitive expectation that senescent cells would continue to accumulate | Contrary to the intuitive expectation that senescent cells would continue to accumulate exponential , research has shown that the growth rate can decline in very advanced age: | ||
# '''Depleted Stem Cell Pools''': With age, the body's pool of stem cells, responsible for tissue regeneration and repair, diminishes. Since there are fewer actively dividing cells in very elderly individuals, there may be fewer cells to enter a senescent state. | # '''Depleted Stem Cell Pools''': With age, the body's pool of stem cells, responsible for tissue regeneration and repair, diminishes. Since there are fewer actively dividing cells in very elderly individuals, there may be fewer cells to enter a senescent state. | ||