Endothelial cell confluence regulates Weibel-Palade body formation

Gareth J. Howell, Shane P. Herbert, Jennifer M. Smith, Shweta Mittar, Lorna C. Ewan, Mudassir Mohammed, Alison R. Hunter, Nigel Simpson, Anthony J. Turner, Ian Zachary, John H. Walker, Sreenivasan Ponnambalam

    Research output: Contribution to journalArticlepeer-review


    Secretory granules called Weibel-Palade bodies (WPBs) containing Von Willebrand factor (VWF) are characteristic of the mammalian endothelium. We hypothesized that vascular-specific antigens such as VWF are linked to endothelial identity and proliferation in vitro. To test this idea, the cellular accumulation of VWF in WPBs was monitored as a function of cell proliferation, confluence and passage number in human umbilical vein endothelial cells (HUVECs). We found that as passage number increased the percentage of cells containing VWF in WPBs was reduced significantly, whilst the protein was still detected within the secretory pathway at all times. However, the endothelial-specific marker protein, PECAM-1, is present on all cells even when WPBs are absent, indicating partial maintenance of endothelial identity. Biochemical studies show that a significant pool of immature pro-VWF can be detected in sub-confluent HUVECs; however, a larger pool of mature, processed VWF is detected in confluent cells. Newly synthesized VWF must thus be differentially sorted and packaged along the secretory pathway in semi-confluent versus confluent endothelial cells. Our studies thus show that WPB formation is linked to the formation of a confluent endothelial monolayer.
    Original languageEnglish
    Pages (from-to)413-421
    Number of pages8
    JournalMolecular Membrane Biology
    Issue number6
    Publication statusPublished - Nov 2004


    • Endoplasmic reticulum
    • Endothelial
    • Trafficking
    • Von Willebrand Factor
    • Weibel-Palade bodies


    Dive into the research topics of 'Endothelial cell confluence regulates Weibel-Palade body formation'. Together they form a unique fingerprint.

    Cite this