UCLA Identifies Senescent Immune Cells Driving Fatty Liver, Reverses Disease in Mice

Overview

• The UCLA study, published Thursday in Nature Aging, ties a buildup of senescent macrophages to fatty liver disease and shows that removing them in mice reverses liver damage.
• Researchers defined a two‑protein marker, p21 and TREM2, that flags truly senescent macrophages rather than normal, active ones.
• Lab tests showed excess LDL cholesterol pushed healthy macrophages into this senescent, inflammatory state marked by the p21‑TREM2 signature.
• In mouse models of fatty liver, the senolytic drug ABT‑263 cleared these cells and cut liver burden, dropping liver weight from about 7% of body weight to roughly 4–5% and reducing body weight by about 25%.
• Analysis of human liver biopsy data found the same signature higher in diseased tissue, and because ABT‑263 is too toxic for people, the team will screen for safer drugs that target these cells.