RANTES/CCL5-induced pro-angiogenic effects depend on CCR1, CCR5 and glycosaminoglycans.

Atherosclerosis involves angiogenesis and inflammation with the ability of endothelial cells and monocytes to respond to chemokines. We addressed here by in vitro and in vivo approaches, the role of the chemokine Regulated on Activation, Normal T Cell Expressed and Secreted (RANTES)/CCL5 on angiogenesis through its receptors CCR1, CCR5, syndecan-1 (SDC-1), syndecan-4 (SDC-4) and CD-44. Our data demonstrate that RANTES/CCL5 is pro-angiogenic in a rat subcutaneous model. This RANTES/CCL5-activity may be related to the in vitro promotion of endothelial cell migration, spreading and neo-vessel formation. RANTES/CCL5-mediated angiogenesis depends at least partly on Vascular Endothelial Growth Factor (VEGF) secretion by endothelial cells, since this effect is decreased when endothelial cells are incubated with anti-VEGF receptor antibodies. RANTES/CCL5-induced chemotaxis is mediated by matrix metalloproteinase-9. We demonstrate that specific receptors of RANTES/CCL5 such as G protein-coupled receptors CCR1 and CCR5, and heparan sulfate proteoglycans, SDC-1, SDC-4 or CD-44, play a major role in RANTES/CCL5-induced angiogenic effects. By the use of two RANTES/CCL5 mutants, [E66A]-RANTES/CCL5 with impaired ability to oligomerize, and [44AANA47]-RANTES/CCL5 mutated in the main RANTES/CCL5-glycosaminoglycan (GAG) binding site, we demonstrate that chemokine oligomerization and binding to GAGs are essential in RANTES/CCL5-induced angiogenic effects. According to these results, new therapeutic strategies based on RANTES/CCL5 can be proposed for neo-angiogenesis after vascular injury. Mutants of RANTES/CCL5 may also represent an innovative approach to prevent the angiogenesis associated with the formation of atherosclerotic plaque.

[Interference of hemoglobin variants on glycated hemoglobin measurement using Architect ci8200 immunoassay (Abbott Diagnostics)]. / Immunodosage de l'hémoglobine glyquée sur ci8200 (Abbott Diagnostics) en présence d'hémoglobines anormales.

The objective of this study was to compare haemoglobin A(1c) (HbA(1c)) levels measured by the immunoturbidimetric assay on ci8200 Architect (Abbott Diagnostics) to those obtained by the high pressure liquid chromatography (HPLC) assay from Tosoh Bioscience. Firstly, we verified correlation between the two methods in 47 subjects without hemoglobin variants: the coefficient of correlation was 0.968 and the regression equation was as follows: y(Abbott) = 0.928x(Tosoh) - 0.081. We then measured HbA(1c) levels by both methods in blood samples of 23 patients with a structural hemoglobin variant (A/S, A/C or S/C). Analysis of these samples revealed significant discrepancies between results of both methods, as indicated by the higher mean value obtained by immunoturbidimetric assay when compared to HPLC assay (7.17 +/- 2.68% vs. 5.86 +/- 1.41%). Classification of patients according to the HAS (French Haute Autorité de Santé) recommendations HbA(1c) was not modified for 68% of patients with abnormal hemoglobin. However, in 32% of cases, discrepancies between the two methods may have clinical importance, which justifies the occurrence of an abnormal hemoglobin when the HbA(1c) assay is performed by the method immunoturbidimetry Abbott Diagnostics.