Mouse study: reviving a cell 'recycling' process helped clear ageing 'zombie cells' and eased lung fibrosis
Einstein researchers report in Nature Aging that a decline in chaperone-mediated autophagy with age lets senescent cells escape immune clearance in mice. An experimental drug, CA77.1, reduced their build-up and lessened lung fibrosis — in animals only, so far.
A team led by Ana Maria Cuervo at Albert Einstein College of Medicine in New York reported in Nature Aging on 5 October 2026 why ageing bodies struggle to clear senescent (“zombie”) cells — cells that stop dividing but linger and fuel inflammation.
The key process
Chaperone-mediated autophagy (CMA) is a cellular recycling system that selectively breaks down damaged or unneeded proteins. Cuervo’s lab had shown earlier that CMA declines with age.
What they found (mostly in mice)
- Mice whose macrophages (immune “clean-up” cells) lacked CMA built up more senescent cells in wounds, and their wounds healed more slowly.
- When cells from young mice became senescent, they boosted CMA; cells from old mice did not. Their undigested proteins were secreted as toxic substances that pushed neighbouring cells into senescence and hindered macrophages from recognising them.
- Macrophages from old mice had lower CMA and were worse at engulfing senescent cells.
- Five months of daily oral CA77.1, a small-molecule CMA activator the group developed earlier, reduced senescent-cell build-up in several organs of aged mice and lowered signs of inflammation and fibrosis. It also restored the engulfing ability of macrophages from old mice to levels comparable with young ones.
- Lung tissue from people with idiopathic pulmonary fibrosis showed markedly reduced CMA, and in a mouse model of the disease, CA77.1 started soon after lung injury reduced fibrosis.
Limitations
Almost all experiments were in mice and isolated cells; the human evidence is limited to analyses of lung tissue samples. CA77.1 has not been shown to be safe or effective in people, and Cuervo says the next challenge is finding out whether the approach can become a safe treatment. The findings also suggest that testing anti-senescence drugs only on cells from young animals may miss how they behave in old bodies. This is laboratory research, not a treatment option — talk to your doctor about any lung or age-related condition.
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