Browsing by Subject "ANGIOPOIETIN-2"

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  • Hamm, Alexander; Veschini, Lorenzo; Takeda, Yukiji; Costa, Sandra; Delamarre, Estelle; Squadrito, Mario Leonardo; Henze, Anne-Theres; Wenes, Mathias; Serneels, Jens; Pucci, Ferdinando; Roncal, Carmen; Anisimov, Andrey; Alitalo, Kari; De Palma, Michele; Mazzone, Massimiliano (2013)
  • Hakanpaa, Laura; Kiss, Elina A.; Jacquemet, Guillaume; Miinalainen, Ilkka; Lerche, Martina; Guzman, Camilo; Mervaala, Eero; Eklund, Lauri; Ivaska, Johanna; Saharinen, Pipsa (2018)
    Loss of endothelial integrity promotes capillary leakage in numerous diseases, including sepsis, but there are no effective therapies for preserving endothelial barrier function. Angiopoietin-2 (ANGPT2) is a context-dependent regulator of vascular leakage that signals via both endothelial TEK receptor tyrosine kinase (TIE2) and integrins. Here, we show that antibodies against beta 1-integrin decrease LPS-induced vascular leakage in murine endotoxemia, as either a preventative or an intervention therapy. beta 1-integrin inhibiting antibodies bound to the vascular endotheliumin vivo improved the integrity of endothelial cell-cell junctions and protected mice from endotoxemia-associated cardiac failure, without affecting endothelial inflammation, serum proinflammatory cytokine levels, or TIE receptor signaling. Moreover, conditional deletion of a single allele of endothelial beta 1-integrin protected mice from LPS-induced vascular leakage. In endothelial mono-layers, the inflammatory agents thrombin, lipopolysaccharide (LPS), and IL-1 beta decreased junctional vascular endothelial (VE)-cadherin and induced actin stress fibers via beta 1- and alpha 5-integrins and ANGPT2. Additionally, beta 1-integrin inhibiting antibodies prevented inflammation-induced endothelial cell contractility and monolayer permeability. Mechanistically, the inflammatory agents stimulated ANGPT2-dependent translocation of alpha 5 beta 1-integrin into tensin-1-positive fibrillar adhesions, which destabilized the endothelial monolayer. Thus, beta 1-integrin promotes endothelial barrier disruption during inflammation, and targeting beta 1-integrin signaling could serve as a novel means of blocking pathological vascular leak.