title: The A2b adenosine receptor protects against vascular injury.
abstract: The A2b adenosine receptor (A2bAR) is highly abundant in bone marrow macrophages and vascular smooth muscle cells (VSMC). To examine the functional significance of this receptor expression, we applied a femoral artery injury model to A2bAR knockout (KO) mice and showed that the A2bAR prevents vascular lesion formation in an injury model that resembles human restenosis after angioplasty. While considering related mechanisms, we noted higher levels of TNF-alpha, an up-regulator of CXCR4, and of VSMC proliferation in the injured KO mice. In accordance, CXCR4, which is known to attract progenitor cells during tissue regeneration, is up-regulated in lesions of the KO mice. In addition, aortic smooth muscle cells derived from A2bAR KO mice display greater proliferation in comparison with controls. Bone marrow transplantation experiments indicated that the majority of the signal for lesion formation in the null mice originates from bone marrow cells. Thus, this study highlights the significance of the A2bAR in regulating CXCR4 expression in vivo and in protecting against vascular lesion formation.
authors.affiliation: Department of Biochemistry and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA.
authors.forename: Dan
authors.initials: D
authors.lastname: Yang
authors.forename: Milka
authors.initials: M
authors.lastname: Koupenova
authors.forename: Donald J
authors.initials: DJ
authors.lastname: McCrann
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Kopeikina
authors.forename: Herbert M
authors.initials: HM
authors.lastname: Kagan
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Schreiber
authors.forename: Katya
authors.initials: K
authors.lastname: Ravid
mesh_terms: D000818:Animals; D001011:Aorta / Q000378:metabolism; D001854:Bone Marrow Cells / Q000378:metabolism; D016026:Bone Marrow Transplantation; D002453:Cell Cycle; D049109:Cell Proliferation; D005786:Gene Expression Regulation; D007249:Inflammation; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000293:injuries / Q000378:metabolism* / Q000473:pathology; D043704:Receptor, Adenosine A2B / Q000378:metabolism / Q000502:physiology*; D019718:Receptors, CXCR4 / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: C514936:CXCR4 protein, mouse; D043704:Receptor, Adenosine A2B; D019718:Receptors, CXCR4; D014409:Tumor Necrosis Factor-alpha