Neutrophil interaction with inflamed postcapillary venule endothelium alters annexin 1 expression.
Annexin 1 (ANX-A1) exerts antimigratory actions in several models of acute and chronic inflammation. This is related to its ability to mimic the effect of endogenous ANX-A1 that is externalized on neutrophil adhesion to the postcapillary endothelium. In the present study we monitored ANX-A1 expression and localization in intravascular and emigrated neutrophils, using a classical model of rat peritonitis. For this purpose, a pair of antibodies raised against the ANX-A1 N-terminus (ie, able to recognize intact ANX-A1) or the whole protein (ie, able to interact with all ANX-A1 isoforms) was used by immunofluorescence and immunocytochemistry analyses. The majority ( approximately 50%) of ANX-A1 on the plasma membrane of intravascular neutrophils was intact. Extravasation into the subendothelial matrix caused loss of this pool of intact protein (to approximately 6%), concomitant with an increase in total amount of the protein; only approximately 25% of the total protein was now recognized by the antibody raised against the N-terminus (ie, it was intact). In the cytoplasm of these cells, ANX-A1 was predominantly associated with large vacuoles, possibly endosomes. In situ hybridization confirmed de novo synthesis of ANX-A1 in the extravasated cells. In conclusion, biochemical pathways leading to the externalization, proteolysis, and synthesis of ANX-A1 are activated during the process of neutrophil extravasation.
Oliani
S M
SM
William Harvey Research Institute, London, United Kingdom.
Paul-Clark
M J
MJ
Christian
H C
HC
Flower
R J
RJ
Perretti
M
M
D000818:Animals; D017305:Annexin A1 / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D002351:Carrageenan / Q000008:administration & dosage; D002448:Cell Adhesion; D002465:Cell Movement; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D005786:Gene Expression Regulation / Q000187:drug effects; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007249:Inflammation / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008297:Male; D008643:Mesentery / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008854:Microscopy, Electron; D009504:Neutrophils / Q000187:drug effects / Q000473:pathology*; D010538:Peritonitis / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D017305:Annexin A1; D012333:RNA, Messenger; D002351:Carrageenan