Effect of C-reactive protein on Fcgamma receptor II in cultured bovine endothelial cells.
The major CRP (C-reactive protein) receptor on leucocytes has been identified as the low-affinity IgG receptor Fcgamma receptor II (CD32). Our aim was to assess whether inflammation may modify the presence of the CD32 receptor in BAEC (bovine aortic endothelial cells). Confocal microscopy experiments showed a weak expression of the CD32 receptor in control BAEC that was slightly increased by 10 microg/ml CRP. Incubation of BAEC with TNF-alpha (tumour necrosis factor-alpha) did not modify the fluorescence signal of CD32. Addition of CRP to TNF-alpha-incubated BAEC enhanced the fluorescence signal of the CD32 receptors. The CD32 receptors showed a perinuclear cytoplasmic localization in BAEC. An alteration of the NO (nitric oxide)-dependent vasorelaxation has been defined as endothelial dysfunction. Endothelial dysfunction has been associated with the presence of superoxide anion and with a reduction in the expression of the eNOS (endothelial NO synthase). A concentration of CRP similar to that detected in patients with cardiovascular risk (10 microg/ml) failed to modify the generation of superoxide anion stimulated by TNF-alpha. Western blot experiments showed that TNF-alpha decreased the expression of the eNOS protein, which was partially protected by treatment with 10 microg/ml CRP. The protective effect of 10 microg/ml CRP on eNOS expression in TNF-alpha-incubated BAEC was prevented by an antibody against CD32 receptors. In conclusion, the present results suggest that, although CRP has been associated with inflammation, CRP may protect the expression of eNOS protein against pro-inflammatory mediators such as TNF-alpha.
Escribano-Burgos
Marta
M
Cardiovascular Research Laboratory, Hospital Clínico San Carlos, Martín Lagos, s/n, 28040 Madrid, Spain.
López-Farré
Antonio
A
del Mar González
María
M
Macaya
Carlos
C
García-Méndez
Antonio
A
Mateos-Cáceres
Petra J
PJ
Alonso-Orgaz
Sergio
S
Carrasco
Carolina
C
Rico
Luis A
LA
Porres Cubero
Juan Carlos
JC
D000818:Animals; D002097:C-Reactive Protein / Q000494:pharmacology*; D002417:Cattle; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000378:metabolism*; D018613:Microscopy, Confocal; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D011946:Receptors, Antigen / Q000378:metabolism; D017452:Receptors, IgG / Q000032:analysis / Q000378:metabolism*; D018709:Statistics, Nonparametric; D013481:Superoxides / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D011946:Receptors, Antigen; D017452:Receptors, IgG; D014409:Tumor Necrosis Factor-alpha; D013481:Superoxides; D002097:C-Reactive Protein; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III