UCLA Researchers Identify and Clear Senescent Macrophages to Reverse Fatty Liver Disease in Mice

Thu, 16 Apr 2026 18:58:00 +0200

UCLA scientists have discovered a population of senescent “zombie” immune cells, specifically macrophages marked by p21 and TREM2 proteins, that accumulate in aging livers and drive chronic inflammation and fatty liver disease. In older mice, these dysfunctional cells can make up 60-80% of liver macrophages, compared to just 5% in young mice. The study found that excess cholesterol from high-fat diets accelerates this senescence process, turning normally protective macrophages into inflammatory drivers that worsen metabolic dysfunction-associated steatotic liver disease. When researchers used the senolytic drug ABT-263 to selectively eliminate these senescent macrophages, the results were striking: liver size normalized, inflammation dropped sharply, and fatty liver damage reversed dramatically even while the mice continued eating an unhealthy diet. Body weight also decreased by about 25%. Analysis of human liver biopsy data showed the same senescent macrophage signature is elevated in