title: Platelets regulate lymphatic vascular development through CLEC-2-SLP-76 signaling.
abstract: Although platelets appear by embryonic day 10.5 in the developing mouse, an embryonic role for these cells has not been identified. The SYK-SLP-76 signaling pathway is required in blood cells to regulate embryonic blood-lymphatic vascular separation, but the cell type and molecular mechanism underlying this regulatory pathway are not known. In the present study we demonstrate that platelets regulate lymphatic vascular development by directly interacting with lymphatic endothelial cells through C-type lectin-like receptor 2 (CLEC-2) receptors. PODOPLANIN (PDPN), a transmembrane protein expressed on the surface of lymphatic endothelial cells, is required in nonhematopoietic cells for blood-lymphatic separation. Genetic loss of the PDPN receptor CLEC-2 ablates PDPN binding by platelets and confers embryonic lymphatic vascular defects like those seen in animals lacking PDPN or SLP-76. Platelet factor 4-Cre-mediated deletion of Slp-76 is sufficient to confer lymphatic vascular defects, identifying platelets as the cell type in which SLP-76 signaling is required to regulate lymphatic vascular development. Consistent with these genetic findings, we observe SLP-76-dependent platelet aggregate formation on the surface of lymphatic endothelial cells in vivo and ex vivo. These studies identify a nonhemostatic pathway in which platelet CLEC-2 receptors bind lymphatic endothelial PDPN and activate SLP-76 signaling to regulate embryonic vascular development.
authors.affiliation: Department of Medicine and Cardiovascular Institute, University of Pennsylvania, 421 Curie Blvd., Philadelphia, PA 19104, USA.
authors.forename: Cara C
authors.initials: CC
authors.lastname: Bertozzi
authors.forename: Alec A
authors.initials: AA
authors.lastname: Schmaier
authors.forename: Patricia
authors.initials: P
authors.lastname: Mericko
authors.forename: Paul R
authors.initials: PR
authors.lastname: Hess
authors.forename: Zhiying
authors.initials: Z
authors.lastname: Zou
authors.forename: Mei
authors.initials: M
authors.lastname: Chen
authors.forename: Chiu-Yu
authors.initials: CY
authors.lastname: Chen
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.forename: Min-min
authors.initials: MM
authors.lastname: Lu
authors.forename: Diane
authors.initials: D
authors.lastname: Zhou
authors.forename: Eric
authors.initials: E
authors.lastname: Sebzda
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Santore
authors.forename: Demetri J
authors.initials: DJ
authors.lastname: Merianos
authors.forename: Matthias
authors.initials: M
authors.lastname: Stadtfeld
authors.forename: Alan W
authors.initials: AW
authors.lastname: Flake
authors.forename: Thomas
authors.initials: T
authors.lastname: Graf
authors.forename: Radek
authors.initials: R
authors.lastname: Skoda
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Maltzman
authors.forename: Gary A
authors.initials: GA
authors.lastname: Koretzky
authors.forename: Mark L
authors.initials: ML
authors.lastname: Kahn
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D001792:Blood Platelets / Q000378:metabolism / Q000502:physiology*; D001808:Blood Vessels / Q000378:metabolism; D002478:Cells, Cultured; D004622:Embryo, Mammalian; D042783:Endothelial Cells / Q000378:metabolism / Q000502:physiology; D004729:Endothelium, Lymphatic / Q000196:embryology / Q000378:metabolism; D004730:Endothelium, Vascular / Q000196:embryology / Q000378:metabolism; D006801:Humans; D037181:Lectins, C-Type / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D042601:Lymphatic Vessels / Q000196:embryology* / Q000378:metabolism / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000378:metabolism / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D011485:Protein Binding; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D000098853:Podoplanin
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D010750:Phosphoproteins; C529518:CLEC-2 protein, mouse; C490441:Pdpn protein, mouse; D000098853:Podoplanin; C092947:SLP-76 signal Transducing adaptor proteins