Targeting zombie cells

When most cells become unable to reproduce any longer, they are ‘zombies’. Companies such as Barcelona-based Senolytx are developing ways to slow the aging process by removing zombie cells from tissues.

Scientists have long known that an accumulation of senescent cells is linked to conditions such as arthritis, Parkinson’s disease, and Alzheimer’s disease.

Despite the potential shown in this recent research, Dr. James Kirkland, a professor of physiology and medicine at the Mayo Clinic in Rochester, Minnesota and senior study author, emphasized that the process isn’t a magic bullet.

“It’s a very preliminary study and we should plan other trials,” Dr. Kirkland told Healthline. “The biggest risk factor for most people is still their chronological age.”

“When we’re young, we get senescent cells constantly,” Timothy Cash, CSO of Senolytx told me. “When we get a wound, senescent cells will form, but they will be removed after their job is done. When we get older, for some reason, senescent cells show up throughout the body but they’re not removed.”

The company is developing small molecule drugs that help to clear the zombie cells from tissues in age-related diseases such as idiopathic pulmonary fibrosis. Currently in the preclinical stage, Senolytx is also developing these drugs for combination therapies in cancer, removing senescent cells left by chemotherapy.

Senolytx also has other treatments in the discovery stage. One approach the company is investigating is to stop senescent cells from harming the tissue around them instead of killing them. Another is triggering the immune system to remove senescent cells. The immune system of young people is normally efficient at doing this, but gets worse over time.

“This might happen because the immune system isn’t as good as it was at training immune cells,” Cash told me. “But I think it’s even more likely that the senescent cells have become sneaky and tricky, and have blocked the immune system from clearing them.”