Localization of beta<sub>2</sub>-glycoprotein 1 in late endosomes of human endothelial cells

Article Article scientifique Article Localization of beta<sub>2</sub>-glycoprotein 1 in late endosomes of human endothelial cells eng 2001-05 author Geindre Sylvie Françoise Division of Angiology and Haemostasis, University Hospital of Geneva, Switzerland. 133391 author Kruithof Egbert 117791 author De Rochemonteix Béatrice Marie Henriette 30663 author Rosnoblet Corinne 23428 author Gruenberg Jean 29661 Département de biochimie (CHIBI) author Reber Guido 99164 author De Moerloose Philippe 26335 903-907 11372686 0340-6245 Antiphospholipid antibodies (APLA) are associated with thrombophilia and recurrent pregnancy loss. Different mechanisms have been proposed to explain their pathogenic effects and among them, we have previously shown that APLA accumulate in late endosomes of human umbilical vein endothelial cells (HUVEC) leading to a redistribution of the cation-independent mannose-6-phosphate receptor (CI-M6PR). Because many APLA are directed towards beta2-glycoprotein 1 (beta2GP1)phospholipid complexes, we investigated the localisation of beta2GP1 in HUVEC. By immunofluorescence analysis, using monoclonal and polyclonal anti-beta2GP1 antibodies, we detected beta2GP1 at the cell surface and in late endosomes. Incubation of HUVEC with anti-beta2GP1 antibodies resulted in antibody accumulation at the cell surface and within late endosomes and in a redistribution of the CI-M6PR from the Golgi apparatus to late endosomes. The anti-beta2GP1 antibodies remained detectable in late endosomes even after several days of incubation in antibody-free medium. The accumulation of anti-beta2GP1 antibodies in late endosomes of endothelial cells and the resulting modification of intracellular protein trafficking may contribute to the pathogenic effects of these antibodies. Antibodies / metabolism Antibodies / pharmacology Antibodies, Antiphospholipid Anticoagulants / immunology Anticoagulants / metabolism Antiphospholipid Syndrome / etiology Endosomes / chemistry Endothelium, Vascular / cytology Endothelium, Vascular / ultrastructure Glycoproteins / immunology Glycoproteins / metabolism Humans Microscopy, Fluorescence Receptor, IGF Type 2 / drug effects Receptor, IGF Type 2 / metabolism Umbilical Veins / cytology Beta 2-Glycoprotein I Dewey 540 39 Département de biochimie 144 false Thrombosis and haemostasis 85 5 61173274-3eeb-4fcc-902b-8a8238b60609 Article (Published version) Restricted Dunoyer-Geindre_TH_200185903.pdf 3187467 application/pdf 23763362af6d0eca17cd3fb9f140b312648d231f495f357eb2917644bab3a126 restrictedAccess Faculté des sciences / Section de chimie et biochimie / Département de biochimie

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Localization of beta₂-glycoprotein 1 in late endosomes of human endothelial cells	Thrombosis and haemostasis			2001	103	0

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