Defects in the intracellular degradation and recycling of cellular components — a process called autophagy — have been linked to several diseases, including cancer. Now two research groups show a link between defective autophagy and heart disease in mice.

Clay Semenkovich at Washington University in St Louis, Missouri, and his colleagues fed a fat-rich 'Western' diet to mice that are genetically susceptible to atherosclerosis, which is marked by the formation of fatty plaques in arterial walls.

They found dysfunctional autophagy in a type of immune cell called a macrophage, which is abundant in the plaques. Other mice engineered to have autophagy-deficient macrophages and fed a fatty diet had more plaques than those with normal autophagy. Moreover, autophagy dysfunction seems to be associated with activation of inflammasomes — protein complexes that trigger inflammation — in the macrophages.

A team led by Ira Tabas at Columbia University in New York has found that mice that had defective macrophage autophagy and ate a fatty diet showed more signs of advanced atherosclerosis, including plaque necrosis, which has been linked to heart attacks and stroke in humans.

Cell Metab. http://dx.doi.org/10.1016/j.cmet.2012.02.011; http://dx.doi.org/10.1016/j.cmet.2012.01.022 (2012)