The role of scavenger receptor class A in the adhesion of cells is dependent on cell type and cellular activation state.
Scavenger receptor class A (SR-A) facilitates the development of atherosclerosis, which might be due to its role in the uptake of modified low-density lipoproteins. However, the receptor is also suggested to be important for cell adhesion, thereby potentially influencing the residence time of cells in vivo. Using SR-A-deficient mice, we investigated the role of SR-A in the adhesion of peritoneal macrophages (PM) and tissue macrophages (Kupffer cells). In resident PM no effect of the absence or presence of SR-A on cell adhesion was observed, either in the presence or in the absence of serum. However, in thioglycollate-induced PM, SR-A is important for adhesion both in the presence and in the absence of serum and more than 85% of the divalent-cation-independent adhesion in the presence of serum is mediated by SR-A. In unactivated Kupffer cells, like in resident PM, adhesion is not influenced by the absence or presence of SR-A. In vivo administration of phorbol 12-myristate 13-acetate leads to the activation of Kupffer cells, and it appears that under these conditions SR-A does contribute to adhesion, since both in the absence and in the presence of serum SR-A is responsible for about 35% of cell adhesion. It is concluded that SR-A is important for the divalent-cation-independent adhesion of activated PM and Kupffer cells, suggesting that SR-A may influence the residence time of cells at sites of cellular activation, e.g., in atherosclerotic plaques and during liver infection.
van Velzen
A G
AG
Leiden-Amsterdam Center for Drug Research, Sylvius Laboratories, Leiden, 2300 RA, The Netherlands. a.velzen@lacdr.leidenuniv.nl
Suzuki
H
H
Kodama
T
T
van Berkel
T J
TJ
D000818:Animals; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000502:physiology*; D007728:Kupffer Cells / Q000187:drug effects / Q000502:physiology*; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D011971:Receptors, Immunologic / Q000235:genetics / Q000502:physiology*; D051116:Receptors, Scavenger; D051117:Scavenger Receptors, Class A; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013864:Thioglycolates / Q000494:pharmacology
D015815:Cell Adhesion Molecules; C495140:Msr1 protein, mouse; D011971:Receptors, Immunologic; D051116:Receptors, Scavenger; D051117:Scavenger Receptors, Class A; D013864:Thioglycolates; D013755:Tetradecanoylphorbol Acetate