Evidence item

Here we show that aging reduces cardiac lymphatic vessel density in humans and mice and induces structural remodeling characterized by tighter, zipper-like endothelial junctions. These changes are associated with immune cell infiltration, fibrinogen and amyloid accumulation, and myocardial edema. Selective reduction of cardiac lymphatics in young mice, through Flt4 (VEGFR3) depletion or soluble Flt4 overexpression, recapitulates key features of cardiac aging, including inflammation and impaired lymphatic integrity. Mechanistically, aging induces selective upregulation of nuclear interleukin-33 (IL-33) in lymphatic endothelial cells... Cardiac Vegfc overexpression or Il33 silencing restores lymphatic density and tissue homeostasis in aged hearts.