An anonymous reader quotes a report from The Guardian: In a lab just south of San Francisco I am looking at two blown-up images of microscope slides on a computer screen, side by side. The slides are the same cross-sections of mouse knees from a six-month-old and an 18-month-old animal. The older mouse’s image has a splattering of little yellow dots, the younger barely any. That staining indicates the presence of so-called senescent cells — “zombie cells” that are damaged and that, as a defense against cancer, have ceased to divide but are also resistant to dying. They are known to accumulate with age, as the immune system can no longer clear them, and as a result of exposure to cell-damaging agents such as radiation and chemotherapy. And they have been identified as a cause of aging in mice, at least partially responsible for most age-related diseases. Seeing the slides, it makes me worried about my own knees. “Tell us about it,” says Pedro Beltran who heads the biology department at Unity Biotechnology, a 90 person-strong company trying to halt, slow or reverse age-associated diseases in humans by killing senescent cells.

Developing therapies to kill senescent cells is a burgeoning part of the wider quest to defeat aging and keep people healthier longer. Unity, which was founded in 2011, has received more than $385m in funding to date including investment from big tech names such as Amazon’s Jeff Bezos and PayPal co-founder Peter Thiel. It went public this May and is valued at more than $700m. Its first drug entered early clinical trials in June, aimed at treating osteoarthritis. Other startups with zombie cells in their sights include Seattle-based Oisin Biotechnologies which was founded in 2016 and has raised around $4m; Senolytic Therapeutics whose scientific development is based in Spain and which was established last September (it won’t disclose its financing other than to say it has a first round, which will allow it to reach clinical trials); and Cleara Biotech, formed this June backed by $3m in funding and based in the Netherlands. In addition, Scottish company CellAge, also founded in 2016, has raised about $100,000 to date, partly through a crowdfunding campaign. The report goes on to detail Unity’s plan to kill senescent cells. Their method is to target the biological pathways senescent cells use to resist the normal death of aging cells. “The company’s approach is to find small molecules (so called ‘senolytics’) that can do this,” reports The Guardian. “But because small molecules, by their nature, can get everywhere in the body, the approach is prone to unwanted side-effects.” As a result, the company has turned to localized treatment. Meanwhile, Oisin is trying to kill all a person’s zombie cells in one go. “The idea is to load the body with nanoparticles that insert a ‘suicide gene’ into every cell,” reports The Guardian. “It only triggers if a cell has a lot of particular protein (p16) that acts as a marker of zombie cells, albeit imperfectly.” …read more

Source:: Slashdot