Endothelial TDP-43 controls sprouting angiogenesis and vascular barrier integrity, and its deletion triggers neuroinflammation.

TDP-43 is a DNA/RNA-binding protein that regulates gene expression and its malfunction in neurons has been causally associated with multiple neurodegenerative disorders. Although progress has been made in understanding the functions of TDP-43 in neurons, little is known about its role in endothelial cells (ECs), angiogenesis and vascular function. Using inducible EC-specific TDP-43 knockout mice, we showed that TDP-43 is required for sprouting angiogenesis, vascular barrier integrity and blood vessel stability. Postnatal EC-specific deletion of TDP-43 leaded to retinal hypovascularization due to defects in vessel sprouting associated with reduced EC proliferation and migration. In mature blood vessels, loss of TDP-43 disrupted the blood-brain barrier and triggered vascular degeneration. These vascular defects were associated with an inflammatory response in the central-nervous system with activation of microglia and astrocytes. Mechanistically, deletion of TDP-43 disrupted fibronectin matrix around sprouting vessels and reduced -catenin signaling in ECs. Together, our results indicate that TDP-43 is essential for the formation of a stable and mature vasculature.