Peptide XIB13 reduces capillary leak in a rodent burn model

Edema due to capillary leak is a generalized and life threatening event in sepsis and major burns for which there is no causal treatment. Local burn wounds are an ideal model to investigate the impact of a new therapeutic agent on edema formation. We aimed to identify peptide sequences of cingulin that can attenuate stress-induced endothelial cytoskeleton disarrangement in vitro and which reduce burn-induced edema in vivo. Cingulin-derived peptides were screened in high content cell culture assays monitoring actin displacement and endothelial cell/cell contacts. The ears of male hairless mice (n=44) were inflicted with full thickness burns using a hot air jet. Mice with and without burn injuries were treated with Xib13 or solvent by continuous intraperitoneal application for 3days. Edema, microcirculation, leukocyte-endothelial interactions and angiogenesis – measured as non-perfused area – were investigated over a 12-day period using intravital fluorescence microscopy. Xib13 reduced endothelial stress formation and stabilized endothelial tight junctions in cell-cultures. In the burn model, Xib13 improved angiogenesis compared to controls (non-perfused area on day 12: 5.7±1.5% vs. 12.0±2.1%; p