eprintid: 10082089 rev_number: 22 eprint_status: archive userid: 608 dir: disk0/10/08/20/89 datestamp: 2019-09-24 09:39:40 lastmod: 2021-10-04 01:24:12 status_changed: 2019-09-24 09:39:40 type: article metadata_visibility: show creators_name: McCormack, JJ creators_name: Harrison-Lavoie, K creators_name: Cutler, DF title: Human endothelial cells size-select their secretory granules for exocytosis to modulate their functional output ispublished: pub divisions: UCL divisions: B02 divisions: C08 divisions: D77 keywords: Endothelial Cells, Exocytosis, Organelle Size, Weibel-Palade Bodies, von Willebrand Factor note: This version is the author accepted manuscript . For information on re-use, please refer to the publisher’s terms and conditions. abstract: BACKGROUND: The secretory granules of endothelial cells, Weibel-Palade bodies, are released in response to numerous extracellular signals. Their cargo is critical to many vascular functions including haemostasis and inflammation. This presents a fundamental problem; how can these cells initiate tailor-made responses from the release of a single type of organelle, each with similar cargo? Each cell contains Weibel-Palade bodies in a wide range of sizes, and we have shown that experimentally-shortening these organelles disproportionately reduces their ability to initiate haemostasis in vitro, leaving leukocyte recruitment unaffected. Could the production of this range of sizes underpin differential responses? OBJECTIVES: To determine whether different agonists drive the exocytosis of different sizes of Weibel-Palade bodies. METHODS: We used a high-throughput automated unbiased imaging workflow to analyse the sizes of Weibel-Palade bodies within HUVECs before and after agonist activation to determine changes in organelle size distributions. RESULTS: We found that a subset of agonists differentially evoke the release of the longest, most pro-haemostatic organelles. Inhibiting the release of these longest organelles by just 15% gives a fall of 60% in an assay of secreted VWF function. CONCLUSIONS: The size-selection of granules for exocytosis represents a novel layer of control, allowing endothelial cells to provide diverse responses to different signals via the release of a single type of organelle. date: 2020-01 date_type: published official_url: https://doi.org/10.1111/jth.14634 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1696399 doi: 10.1111/jth.14634 lyricists_name: Cutler, Daniel lyricists_name: McCormack, Jessica lyricists_id: DFCUT81 lyricists_id: JJMCC62 actors_name: Cutler, Daniel actors_id: DFCUT81 actors_role: owner full_text_status: public publication: Journal of Thrombosis and Haemostasis volume: 18 number: 1 pagerange: 243-254 event_location: England issn: 1538-7836 citation: McCormack, JJ; Harrison-Lavoie, K; Cutler, DF; (2020) Human endothelial cells size-select their secretory granules for exocytosis to modulate their functional output. Journal of Thrombosis and Haemostasis , 18 (1) pp. 243-254. 10.1111/jth.14634 <https://doi.org/10.1111/jth.14634>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10082089/1/McCormack%20et%20al.pdf