title: Functional consequences of inhibiting exocytosis of Weibel-Palade bodies in acute renal ischemia.
abstract: Exocytosis of Weibel-Palade bodies (WPB) represents a distinct response of endothelial cells to stressors, and local release of WPB contents leads to systemic escalation of this response. We synthesized a glycine-(Nα-Et)lysine-proline-arginine (ITF 1697) peptide that has a potential to inhibit exocytosis of WPB and protect microcirculation. Here, we confirmed an inhibitory effect of ITF 1697 using intravital videoimaging and point-tracking of individual organelles. In an in vivo study, mice were implanted with Alzet osmotic pumps (10 μg ITF 1697·kg(-1)·min(-1) at volume of 1 μl/h) and subjected to renal ischemia (IRI). IRI resulted in marked renal injury and elevation of serum creatinine in mice treated with a vehicle. In contrast, renal injury and elevation of creatinine were significantly ameliorated in mice subjected to IRI and receiving ITF 1697. ITF 1697 prevented a systemic response to IRI: a significant surge in the levels of eotaxin and IL-8 (KC; both components of WPB), IL-1α, IL-1β, and RANTES was all prevented or blunted by the administration of ITF 1697, whereas the levels of an anti-inflammatory, IL-10, and macrophage inflammatory protein-1α were upregulated in ITF 1697-treated animals. En face staining of aortic endothelial cells showed that WPB were depleted after 40-180 min post-IRI, and this was significantly blunted in aortic preparations obtained from mice treated with ITF 1697. WPB exocytosis contributed to IRI-associated mobilization of endothelial progenitor cells and hematopoietic stem cells, and ITF 1697 blunted their mobilization. Unexpectedly, 1 mo after IRI, mice treated with ITF 1697 showed a significantly more pronounced degree of scarring than nontreated animals. In conclusion, 1) application of ITF 1697 inhibits exocytosis of WPB and IRI; 2) the systemic inflammatory response of IRI is in part due to the exocytosis of WPB and its blockade blunts it; and 3) ITF 1697 improves short-term renal function after IRI, but not the long-term fibrotic complications.
authors.affiliation: Dept. of Medicine, Renal Research Institute, New York Medical College, Valhalla, NY, USA. Kaoru_Yasuda@nymc.edu
authors.forename: Kaoru
authors.initials: K
authors.lastname: Yasuda
authors.forename: Radovan
authors.initials: R
authors.lastname: Vasko
authors.forename: Peter
authors.initials: P
authors.lastname: Hayek
authors.forename: Brian
authors.initials: B
authors.lastname: Ratliff
authors.forename: Hasan
authors.initials: H
authors.lastname: Bicer
authors.forename: Jonathan
authors.initials: J
authors.lastname: Mares
authors.forename: Shoichi
authors.initials: S
authors.lastname: Maruyama
authors.forename: Silvia
authors.initials: S
authors.lastname: Bertuglia
authors.forename: Paolo
authors.initials: P
authors.lastname: Mascagni
authors.forename: Michael S
authors.initials: MS
authors.lastname: Goligorsky
mesh_terms: D000208:Acute Disease; D058186:Acute Kidney Injury / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D001011:Aorta; D003404:Creatinine; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D042783:Endothelial Cells; D005089:Exocytosis / Q000502:physiology*; D005786:Gene Expression Regulation; D006801:Humans; D007668:Kidney / Q000293:injuries / Q000473:pathology; D008297:Male; D051379:Mice; D018715:Microscopy, Video; D009842:Oligopeptides / Q000494:pharmacology*; D015427:Reperfusion Injury; D013234:Stem Cells / Q000502:physiology; D020302:Weibel-Palade Bodies; D014841:von Willebrand Factor / Q000378:metabolism
chemical_list: D016207:Cytokines; D009842:Oligopeptides; C487621:glycyl-(ethyl)lysyl-prolyl-arginine; D014841:von Willebrand Factor; D003404:Creatinine