title: Sarcoplasmic/endoplasmic reticulum Ca2+ ATPase C674 promotes ischemia- and hypoxia-induced angiogenesis via coordinated endothelial cell and macrophage function.
abstract: Ischemia is a complex phenomenon modulated by the concerted action of several cell types. We have identified that sarcoplasmic/endoplasmic reticulum Ca(2+) ATPase 2 (SERCA 2) cysteine 674 (C674) S-glutathiolation is essential for ischemic angiogenesis, vascular endothelial growth factor (VEGF)-mediated endothelial cell (EC) migration and network formation. A heterozygote SERCA 2 C674S knockin (SKI) mouse shows impaired ischemic blood flow recovery after femoral artery ligation, and its ECs show depleted endoplasmic reticulum (ER) Ca(2+) stores and impaired angiogenic behavior. Here we studied the role of SERCA 2 C674 in the interaction between ECs and macrophages in the context of ischemia and discovered the involvement of the ER stress response protein, ER oxidoreductin-1α (ERO1). In wild type (WT) mice, expression of ERO1 was increased in the ischemic hind limb in vivo, as well as in ECs and macrophages exposed to hypoxia in vitro. The increase in ERO1 to ischemia/hypoxia was less in SKI mice. In WT ECs, both vascular cell adhesion molecule 1 (VCAM1) expression and bone marrow-derived macrophage adhesion to ECs were increased by hypoxia, and both were attenuated in SKI ECs. In WT ECs, ERO1 siRNA blocked hypoxia-induced VCAM1 expression and macrophage adhesion. In WT macrophages, hypoxia also stimulated both ERO1 and VEGF expression, and both were less in SKI macrophages. Compared with conditioned media of hypoxic SKI macrophages, conditioned media from WT macrophages had a greater effect on EC angiogenic behavior, and were blocked by VEGF neutralizing antibody. Taken together, under hypoxic conditions, SERCA 2 C674 and ERO1 enable increased VCAM1 expression and macrophage adhesion to ECs, as well as macrophage VEGF production that, in turn, promote angiogenesis. This study highlights the hitherto unrecognized interaction of two ER proteins, SERCA 2 C674 and ERO1, which mediate the EC and macrophage angiogenic response to ischemia/hypoxia.
authors.affiliation: Vascular Biology Section, Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Mei
authors.affiliation: Vascular Biology Section, Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA.
authors.forename: Melissa D
authors.initials: MD
authors.lastname: Thompson
authors.affiliation: Vascular Biology Section, Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA.
authors.forename: Yasunaga
authors.initials: Y
authors.lastname: Shiraishi
authors.affiliation: Vascular Biology Section, Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA. Electronic address: racohen@bu.edu.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Cohen
authors.affiliation: Innovative Drug Research Centre, Chongqing University, Chongqing 401331, China. Electronic address: xy_tong@yahoo.com.
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Tong
mesh_terms: D000818:Animals; D002465:Cell Movement; D049109:Cell Proliferation; D003545:Cysteine / Q000378:metabolism; D042783:Endothelial Cells / Q000502:physiology*; D004730:Endothelium, Vascular / Q000473:pathology; D006023:Glycoproteins / Q000378:metabolism; D006614:Hindlimb / Q000098:blood supply; D007511:Ischemia / Q000378:metabolism / Q000503:physiopathology; D008264:Macrophages / Q000502:physiology*; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D055806:Microvessels / Q000473:pathology; D018919:Neovascularization, Physiologic; D010088:Oxidoreductases; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000502:physiology*; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis
chemical_list: D006023:Glycoproteins; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; C491864:Ero1l protein, mouse; D010088:Oxidoreductases; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; C506947:Atp2a2 protein, mouse; D003545:Cysteine
keywords: Endoplasmic reticulum oxidoreductin-1; Ischemia/hypoxia; Macrophage; Sarcoplasmic/endoplasmic reticulum Ca(2+) ATPase; Vascular endothelialgrowth factor