TY - JOUR
T1 - Endothelial transmigration hotspots limit vascular leakage through heterogeneous expression of ICAM-1
AU - Grönloh, Max L. B.
AU - Arts, Janine J. G.
AU - Palacios Martínez, Sebastián
AU - van der Veen, Amerens A.
AU - Kempers, Lanette
AU - van Steen, Abraham C. I.
AU - Roelofs, Joris J. T. H.
AU - Nolte, Martijn A.
AU - Goedhart, Joachim
AU - van Buul, Jaap D.
N1 - Funding Information: This work was supported by ZonMW NWO Vici grant # 91819632, and Landsteiner Foundation for Blood Transfusion Research (LSBR) 1649 & 1820. Publisher Copyright: © 2022 The Authors. Published under the terms of the CC BY 4.0 license.
PY - 2023/1/9
Y1 - 2023/1/9
N2 - Upon inflammation, leukocytes leave the circulation by crossing the endothelial monolayer at specific transmigration “hotspot” regions. Although these regions support leukocyte transmigration, their functionality is not clear. We found that endothelial hotspots function to limit vascular leakage during transmigration events. Using the photoconvertible probe mEos4b, we traced back and identified original endothelial transmigration hotspots. Using this method, we show that the heterogeneous distribution of ICAM-1 determines the location of the transmigration hotspot. Interestingly, the loss of ICAM-1 heterogeneity either by CRISPR/Cas9-induced knockout of ICAM-1 or equalizing the distribution of ICAM-1 in all endothelial cells results in the loss of TEM hotspots but not necessarily in reduced TEM events. Functionally, the loss of endothelial hotspots results in increased vascular leakage during TEM. Mechanistically, we demonstrate that the 3 extracellular Ig-like domains of ICAM-1 are crucial for hotspot recognition. However, the intracellular tail of ICAM-1 and the 4th Ig-like dimerization domain are not involved, indicating that intracellular signaling or ICAM-1 dimerization is not required for hotspot recognition. Together, we discovered that hotspots function to limit vascular leakage during inflammation-induced extravasation.
AB - Upon inflammation, leukocytes leave the circulation by crossing the endothelial monolayer at specific transmigration “hotspot” regions. Although these regions support leukocyte transmigration, their functionality is not clear. We found that endothelial hotspots function to limit vascular leakage during transmigration events. Using the photoconvertible probe mEos4b, we traced back and identified original endothelial transmigration hotspots. Using this method, we show that the heterogeneous distribution of ICAM-1 determines the location of the transmigration hotspot. Interestingly, the loss of ICAM-1 heterogeneity either by CRISPR/Cas9-induced knockout of ICAM-1 or equalizing the distribution of ICAM-1 in all endothelial cells results in the loss of TEM hotspots but not necessarily in reduced TEM events. Functionally, the loss of endothelial hotspots results in increased vascular leakage during TEM. Mechanistically, we demonstrate that the 3 extracellular Ig-like domains of ICAM-1 are crucial for hotspot recognition. However, the intracellular tail of ICAM-1 and the 4th Ig-like dimerization domain are not involved, indicating that intracellular signaling or ICAM-1 dimerization is not required for hotspot recognition. Together, we discovered that hotspots function to limit vascular leakage during inflammation-induced extravasation.
KW - ICAM-1
KW - inflammation
KW - leakage
KW - transendothelial migration hotspots
UR - http://www.scopus.com/inward/record.url?scp=85142075877&partnerID=8YFLogxK
U2 - https://doi.org/10.15252/embr.202255483
DO - https://doi.org/10.15252/embr.202255483
M3 - Article
C2 - 36382783
SN - 1469-221X
VL - 24
SP - e55483
JO - EMBO reports
JF - EMBO reports
IS - 1
M1 - e55483
ER -