A Broad Spectrum Drug To Kill Senescent Cells

Hass et al. Cell Communication and Signaling 2011 9:12

Senescent cells no longer divide and stick around causing damage around the body. They are a key target in any rejuvenation strategy, and in the search for a solution a new drug has emerged that may selectively kill these old cells.

Getting rid of old cells

Cellular senescence is a curious mechanism that occurs in response to genotoxic damage, replicative exhaustion or mitochondrial defects. While it may have some benefit in youth and help wound repair, these cells accumulate with age and begin to drive systemic inflammation, corrupt stem cells and disrupt healthy tissue function across the body. They're therefore an important hallmark of an aging body. 

There have been various proposed strategies to deal with the old, senescent cells that appear in larger number in elderly tissue. Some involve genetic engineering and nanotechnology, but previous work has also demonstrated the feasibility of drugs that selectively target senescent cells across the body. 

There are a number of different potential strategies for dealing with senescent cells

An anti-senescence drug

In an addition to this developing field, researchers have demonstrated that an anti-cancer drug ABT-263 can also destroy senescent cells. When given orally to aging mice and mice that had been irradiated to induce premature aging of their hematopoetic (blood producing) system, ABT-263 was able to significantly deplete senescent cells and even senescent stem cells in the bone marrow and muscle. This treatment then had a rejuvenative effect on stem cell activity in these mice. 

"Our results demonstrate that clearance of senescent cells by a pharmacological agent is beneficial in part by rejuvenating aged tissue stem cells. Because a decline in tissue stem cell function is associated with exposure to radiation and aging, we believe clearing senescent cells and rejuvenation of tissue stem cells could have a major impact on mitigation of radiation injury and treatment of diseases of aging"

A warning

While the drug shows promising data, ABT-263 has toxic side effects that make it an undesirable treatment option. A further understanding of the structure of the drug and greater exploration of more small molecule alternatives could lead to a treatment that eliminates aged cells without causing excess harm. 

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