title: Angiotensin II up-regulates CX3CR1 expression in THP-1 monocytes: impact on vascular inflammation and atherogenesis.
abstract: The potential regulatory effect of angiotensins on circulating mononuclear cell activation and migration has not yet been thoroughly evaluated. Using flow cytometry we assessed the possible effect of angiotensin I and II on the expression of CX3CR1 and a single representative of each major chemokine family (CCR5 and CXCR4) in THP-1 monocytes, Jurcat T lymphocytes and primary monocytes-isolated from healthy donors. Fluorescence intensity and the rate of chemokine-positive cells was measured in naïve cells and cells treated with angiotensin I and II. Neither angiotensin I nor angiotensin II exhibited any effect on fluorescence intensity and the rate of CX3CR1-, CCR5- and CXCR4-positive cells in primary peripheral blood mononuclear cells and Jurkat T cells. However, angiotensin II significantly increased the rate of CX3CR1-positive THP-1 cells. This effect was not attenuated by the pre-incubation of THP-1 cells with the AT-1 receptor blocker losartan, suggesting that this was not an AT-1-mediated effect. Angiotensin I and II had no effect on fluorescence intensity and the rate of CCR5- and CXCR4-positive THP-1 cells. In conclusion, angiotensin II increases the rate of CX3CR1-positive THP-1 cells. By extrapolating this in vitro observation to disease mechanisms, we speculate that angiotensin II induces up-regulation of CX3CR1 and promotes firm adhesion of circulation CX3CR1-positive monocytes on CX3CL1 expressing endothelial cells inducing vascular inflammation and atherogenesis.
authors.affiliation: Department of Clinical Virology, Faculty of Medicine, University of Crete, Heraklion, Greece.
authors.forename: Stavros
authors.initials: S
authors.lastname: Apostolakis
authors.forename: Zacharenia
authors.initials: Z
authors.lastname: Vlata
authors.forename: Konstantina
authors.initials: K
authors.lastname: Vogiatzi
authors.forename: Elias
authors.initials: E
authors.lastname: Krambovitis
authors.forename: Demetrios A
authors.initials: DA
authors.lastname: Spandidos
mesh_terms: D000803:Angiotensin I / Q000378:metabolism / Q000494:pharmacology; D000804:Angiotensin II / Q000378:metabolism / Q000494:pharmacology*; D047228:Angiotensin II Type 1 Receptor Blockers; D050197:Atherosclerosis / Q000378:metabolism*; D000073883:CX3C Chemokine Receptor 1; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D054428:Chemokine CX3CL1 / Q000096:biosynthesis; D042783:Endothelial Cells / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D019169:Jurkat Cells; D019808:Losartan / Q000494:pharmacology; D009000:Monocytes / Q000378:metabolism*; D019713:Receptors, CCR5 / Q000096:biosynthesis; D019718:Receptors, CXCR4 / Q000096:biosynthesis; D019707:Receptors, Chemokine / Q000096:biosynthesis*; D014657:Vasculitis / Q000378:metabolism*; D014662:Vasoconstrictor Agents / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D000073883:CX3C Chemokine Receptor 1; C515538:CX3CL1 protein, human; C095235:CX3CR1 protein, human; C527276:CXCR4 protein, human; D054428:Chemokine CX3CL1; D019713:Receptors, CCR5; D019718:Receptors, CXCR4; D019707:Receptors, Chemokine; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; D000803:Angiotensin I; D019808:Losartan