Stem cell exhaustion and its role in healthy aging

Stem cell exhaustion and its role in healthy aging Scientist Sarallah Rezazadeh from the Icahn School of Medicine explores the molecular mechanisms behind adult stem cells as we age. Stem cell exhaustion is the gradual decline in the function and regenerative potential of adult stem cells over time. In various tissues, the upkeep of homeostasis and the capacity to regenerate after injury depend on tissue-specific adult stem cells. These stem cells typically follow tissue-specific differentiation patterns. Their ability to alternate between states of rest (quiescence) and active proliferation is crucial for their survival and for preserving normal physiological function and regenerative capabilities. (1) Adult tissue-specific stem cells exhibit an extraordinary degree of plasticity as they transit through cellular states from a quiescent to an activated stem cell state and then revert to their original quiescent state. (2) To protect against infection and promote healing, the usual homeostatic signals that regulate transition through quiescent and active states – referred to as the ‘milieu intérieur’ by Claude Bernard in 1865 – must be bypassed in ways that are still not fully understood. (2)