Researchers discover how tissues adapt cellular waste removal

Researchers from the Centro Nacional de Investigaciones Cardiovasculares Carlos III, Pompeu Fabra University, UCSF, and Yale have identified how high-energy tissues adapt their waste removal capabilities. The study, published in Science Immunology, focuses on how tissues like cardiac muscle, skeletal muscle, and brown fat manage metabolic byproducts.

As cells function, their mitochondria—the organelles responsible for energy production—become damaged and must be discarded. The study found that tissues with higher energy demands recruit larger teams of macrophages, a type of immune cell, to clear these damaged mitochondria.

In mouse models, researchers observed that when macrophages were prevented from removing this cellular waste, tissue function declined significantly: the heart lost pumping capacity, skeletal muscle weakened, and brown fat lost its ability to generate heat. The research also linked the process to fibroblasts, which increase in number alongside mitochondrial activity to help manage the cleaning process.