title: PDZRN3 destabilizes endothelial cell-cell junctions through a PKCζ-containing polarity complex to increase vascular permeability.
abstract: Endothelial cells serve as a barrier between blood and tissues. Maintenance of the endothelial cell barrier depends on the integrity of intercellular junctions, which is regulated by a polarity complex that includes the ζ isoform of atypical protein kinase C (PKCζ) and partitioning defective 3 (PAR3). We revealed that the E3 ubiquitin ligase PDZ domain-containing ring finger 3 (PDZRN3) regulated endothelial intercellular junction integrity. Endothelial cell-specific overexpression of Pdzrn3 led to early embryonic lethality with severe hemorrhaging and altered organization of endothelial intercellular junctions. Conversely, endothelial-specific loss of Pdzrn3 prevented vascular leakage in a mouse model of transient ischemic stroke, an effect that was mimicked by pharmacological inhibition of PKCζ. PDZRN3 regulated Wnt signaling and associated with a complex containing PAR3, PKCζ, and the multi-PDZ domain protein MUPP1 (Discs Lost-multi-PDZ domain protein 1) and targeted MUPP1 for proteasomal degradation in transfected cells. Transient ischemic stroke increased the ubiquitination of MUPP1, and deficiency of MUPP1 in endothelial cells was associated with decreased localization of PKCζ and PAR3 at intercellular junctions. In endothelial cells, Pdzrn3 overexpression increased permeability through a PKCζ-dependent pathway. In contrast, Pdzrn3 depletion enhanced PKCζ accumulation at cell-cell contacts and reinforced the cortical actin cytoskeleton under stress conditions. These findings reveal how PDZRN3 regulates vascular permeability through a PKCζ-containing complex.
authors.affiliation: Univ. Bordeaux, INSERM, UMR1034, Biology of Cardiovascular Diseases, F-33600 Pessac, France.|Laboratorium voor Endotheliale Moleculaire Biologie (Vesalius Research Center), 3000 Leuven, Belgium.
authors.forename: Raj N
authors.initials: RN
authors.lastname: Sewduth
authors.affiliation: Univ. Bordeaux, INSERM, UMR1034, Biology of Cardiovascular Diseases, F-33600 Pessac, France.
authors.forename: Héléna
authors.initials: H
authors.lastname: Kovacic
authors.affiliation: Univ. Bordeaux, INSERM, UMR1034, Biology of Cardiovascular Diseases, F-33600 Pessac, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Jaspard-Vinassa
authors.affiliation: CHU de Bordeaux, Service de Neurochirurgie, F-33000 Bordeaux, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Jecko
authors.affiliation: CHU de Bordeaux, Service de Neurochirurgie, F-33000 Bordeaux, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wavasseur
authors.affiliation: Univ. Bordeaux, INSERM, UMR1034, Biology of Cardiovascular Diseases, F-33600 Pessac, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Fritsch
authors.affiliation: Univ. Bordeaux, INSERM, UMR1034, Biology of Cardiovascular Diseases, F-33600 Pessac, France.|CHU de Bordeaux, Service des Maladies Cardiaques et Vasculaires, F-33600 Pessac, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Pernot
authors.affiliation: Univ. Bordeaux, INSERM, UMR1034, Biology of Cardiovascular Diseases, F-33600 Pessac, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Jeaningros
authors.affiliation: Univ. Bordeaux, INSERM, UMR1034, Biology of Cardiovascular Diseases, F-33600 Pessac, France.
authors.forename: Etienne
authors.initials: E
authors.lastname: Roux
authors.affiliation: Univ. Bordeaux, INSERM, UMR1034, Biology of Cardiovascular Diseases, F-33600 Pessac, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: Dufourcq
authors.affiliation: Univ. Bordeaux, INSERM, UMR1034, Biology of Cardiovascular Diseases, F-33600 Pessac, France.|CHU de Bordeaux, Service des Maladies Cardiaques et Vasculaires, F-33600 Pessac, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Couffinhal
authors.affiliation: Univ. Bordeaux, INSERM, UMR1034, Biology of Cardiovascular Diseases, F-33600 Pessac, France. cecile.duplaa@inserm.fr.
authors.forename: Cécile
authors.initials: C
authors.lastname: Duplàa
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001921:Brain / Q000098:blood supply / Q000196:embryology / Q000378:metabolism; D002199:Capillary Permeability; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004622:Embryo, Mammalian / Q000098:blood supply / Q000196:embryology / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000150:complications / Q000235:genetics / Q000378:metabolism; D007365:Intercellular Junctions; D008565:Membrane Proteins; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D020521:Stroke / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D060449:Wnt Signaling Pathway / Q000235:genetics; D000099221:Protein Kinase C zeta
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D015815:Cell Adhesion Molecules; D018797:Cell Cycle Proteins; D008565:Membrane Proteins; D011493:Protein Kinase C; D044767:Ubiquitin-Protein Ligases; D000099221:Protein Kinase C zeta; C491750:Mpdz protein, mouse; C115084:Pard3 protein, mouse; C582444:PDZRN3 protein, mouse