Abstract
Regenerating vascular endothelium under sepsis, trauma, and viral infections is vital for promoting the resolution of inflammatory diseases such as acute lung injury (ALI). Transient receptor potential canonical (TRPC) channels mediated Ca (2+) entry compromises organ functions and survival from lung injury. Through decoding the domain in TRPC6 responsible for vascular injury, we unveiled the intricate molecular mechanisms underlying vascular regeneration in injured tissue. We found that the substitution of isoleucine (111) within the I (st) ankyrin domain of TRPC6 for its isomer (111) leucine (I (111) L-TRPC6) altered channel localization at the membrane, blocked TRPC6-mediated Ca (2+) entry and cation currents without affecting TRPC6 protein expression. Next, we delivered WT-TRPC6 and I (111) L-TRPC6 to the endothelial cells (ECs) of TRPC6 knockout mice using liposomes and found that while WT-TRPC6 induced lung vascular inflammatory injury and EC death these responses were blocked in lungs expressing I (111) L-TRPC6 mutant. Instead, the I (111) L-TRPC6 mutant promoted lung EC proliferation and prevented vascular injury. These responses were recapitulated in a preclinical mouse model of ALI after injection of engineered TRPC6-blocking peptide, suggesting a novel strategy for regenerating anti-inflammatory vascular niche and preventing ALI therapeutically.