Endothelial cell responses in sepsis are attenuated by targeting truncated procalcitonin.

Sepsis is associated with hypotension, vascular leakage, vasoplegia and microvascular dysfunction. Therefore, the endothelium is a target for sepsis therapies. Since truncated procalcitonin exerts vascular activity, we here evaluated the efficacy of targeting procalcitonin for vascular integrity and sepsis outcomes. Sepsis up-regulated >2000 genes involved in pro-inflammatory responses while similar numbers of genes involving cell growth and maintenance were down-regulated. Transcriptomic changes in endothelial cells diminished by >50% by anti-procalcitonin antibodies and this was functionally associated with preserved vascular barrier integrity in lungs and intestines, reduced sepsis-induced vasoplegia, preserved endothelial nitric oxide bioavailability, improved organ integrity and reduced sepsis severity in mice. Mechanistically, procalcitonin neutralization was associated with reduced signaling of the interleukin-17 pathway. We here show sepsis induces substantial changes to the endothelial transcriptome and vascular integrity and neutralizing procalcitonin is a suitable means to preserve endothelial homeostasis at a transcriptomic and functional level that could translate into organ protection during sepsis.