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Endothelial cell morphology creates preferred regions for leukocyte transmigration at venular convergences
Author(s) -
Sumagin Ronen,
Sarelius Ingrid H
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.949.9
Subject(s) - confocal , intravital microscopy , confocal microscopy , cremaster muscle , cell junction , chemistry , morphology (biology) , biophysics , tight junction , anatomy , microbiology and biotechnology , cell , biology , geometry , in vivo , biochemistry , mathematics , genetics
Leukocyte transmigration (TEM) occurs mainly via endothelial cell (EC) junctions, but whether there is a preference for two‐ or tri‐cellular junctions is not clear. Using intravital confocal microscopy of anesthetized mouse cremaster muscle in combination with immunofluorescence labeling we showed that leukocyte TEM in venular convergences was 8‐fold higher than in straight venular regions. Interestingly, due to the difference in EC size, shape and orientation, the number of tri‐cellular junctions in converging venules is significantly higher than in straight regions (20.7±1.2 vs 12.43±1.1/6000μm 2 respectively). The majority (55±1.8%) of adhered leukocytes in venular convergences were found at the tri‐cellular junctions, compared to only 21±2.8% in straight regions. Importantly, 45.1±4% of leukocytes in these straight regions and 59.3±2% in venular convergences used the tri‐cellular junctions for TEM, suggesting tri‐cellular junctions as the preferred route. Leukocyte crawling distances were shorter (17.8±2.4μm vs 26.2±2.6μm) and the TEM efficiency was higher in venular convergences (32.8±6.1 %/total adhered) compared to straight venular regions (14.6±6.1, %/total adhered). We also found that 42.2±4% of the tri‐cellular junctions in both regions were surrounded by ICAM‐1 enriched areas, supporting their role as portals for leukocyte TEM. Supported by NIH HL 18208, HL 75186 and AHA 0615677T