title: CC chemokine receptor 5 influences late-stage atherosclerosis.
abstract: Members of the chemokine system, play a central role in inflammatory processes that underlie the pathogenesis of atherosclerosis and possibly, aortic valve sclerosis. Here we show that genetic inactivation of CC chemokine receptor 5 (CCR5) in the atherosclerosis-prone Apoe-/- mice (Apoe-/- Ccr5-/-) fed a normal chow or a high-fat diet (HFD) are protected against advanced atherosclerosis as well as age-associated aortic valve thickening (AAAVT)--a murine correlate of aortic valve sclerosis. Notably, human sclerotic valves contained CCR5+ cells. We confirm that Apoe-/- Ccr5-/- mice does not influence early-atherosclerotic stage. Adoptive transfer studies showed that the atheroprotective effect of CCR5 inactivation resided in the bone marrow compartment, but was not dependent on T-cells. The CCR5-null state was associated with phenotypes postulated to be atheroprotective such as reduced macrophage accumulation in the plaque, and lower circulating levels of IL-6 and MCP-5. The lack of CCR5 expression in Apoe-/- mice was also associated with higher numbers of endothelial progenitor cells (EPCs)--another postulated athero-protective factor. Compared with controls, carriers of a polymorphism in the Ccr5 gene that leads to the lack of CCR5 in the cell surface had an increased mean percentage of EPCs, but this difference did not reach statistical significance. Collectively, these findings underscore a critical role of CCR5 in age-associated cardiovascular diseases, and highlight that the effects of the chemokine system can be temporally constrained to distinct stages of these disease processes.
authors.affiliation: South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, TX, United States.
authors.forename: Marlon P
authors.initials: MP
authors.lastname: Quinones
authors.forename: Hernan G
authors.initials: HG
authors.lastname: Martinez
authors.forename: Fabio
authors.initials: F
authors.lastname: Jimenez
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Estrada
authors.forename: Molly
authors.initials: M
authors.lastname: Dudley
authors.forename: Opal
authors.initials: O
authors.lastname: Willmon
authors.forename: Hemant
authors.initials: H
authors.lastname: Kulkarni
authors.forename: Robert L
authors.initials: RL
authors.lastname: Reddick
authors.forename: Gabriel
authors.initials: G
authors.lastname: Fernandes
authors.forename: William A
authors.initials: WA
authors.lastname: Kuziel
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Ahuja
authors.forename: Seema S
authors.initials: SS
authors.lastname: Ahuja
mesh_terms: D000367:Age Factors; D000818:Animals; D001021:Aortic Valve / Q000378:metabolism; D050197:Atherosclerosis / Q000378:metabolism*; D001854:Bone Marrow Cells / Q000378:metabolism; D016026:Bone Marrow Transplantation; D005786:Gene Expression Regulation; D006801:Humans; D007249:Inflammation; D015850:Interleukin-6 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D019713:Receptors, CCR5 / Q000378:metabolism* / Q000502:physiology*; D013234:Stem Cells / Q000378:metabolism
chemical_list: D015850:Interleukin-6; D019713:Receptors, CCR5