GDNF restores human blood-nerve barrier function via RET tyrosine kinase-mediated cytoskeletal reorganization

► GDNF sufficiently and potently induced human BNB recovery following 48 h of serum withdrawal in vitro. ► Human BNB endothelial cells express GFRα1, enhanced by exogenous GDNF. ► GDNF induced BNB recovery via RET tyrosine-kinase 2nd messenger signaling. ► GDNF relocated F-actin cytoskeletal filaments to endothelial cell membranes. ► GDNF facilitated more continuous barrier-forming intercellular contacts at the BNB.