title: The regulatory roles of apoptosis-inducing factor in the formation and regression processes of ocular neovascularization.
abstract: The role of apoptosis in the formation and regression of neovascularization is largely hypothesized, although the detailed mechanism remains unclear. Inflammatory cells and endothelial cells both participate and interact during neovascularization. During the early stage, these cells may migrate into an angiogenic site and form a pro-angiogenic microenvironment. Some angiogenic vessels appear to regress, whereas some vessels mature and remain. The control mechanisms of these processes, however, remain unknown. Previously, we reported that the prevention of mitochondrial apoptosis contributed to cellular survival via the prevention of the release of proapoptotic factors, such as apoptosis-inducing factor (AIF) and cytochrome c. In this study, we investigated the regulatory role of cellular apoptosis in angiogenesis using two models of ocular neovascularization: laser injury choroidal neovascularization and VEGF-induced corneal neovascularization in AIF-deficient mice. Averting apoptosis in AIF-deficient mice decreased apoptosis of leukocytes and endothelial cells compared to wild-type mice and resulted in the persistence of these cells at angiogenic sites in vitro and in vivo. Consequently, AIF deficiency expanded neovascularization and diminished vessel regression in these two models. We also observed that peritoneal macrophages from AIF-deficient mice showed anti-apoptotic survival compared to wild-type mice under conditions of starvation. Our data suggest that AIF-related apoptosis plays an important role in neovascularization and that mitochondria-regulated apoptosis could offer a new target for the treatment of pathological angiogenesis.
authors.affiliation: Angiogenesis Laboratory, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Toshio
authors.initials: T
authors.lastname: Hisatomi
authors.forename: Shintaro
authors.initials: S
authors.lastname: Nakao
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Murakami
authors.forename: Kousuke
authors.initials: K
authors.lastname: Noda
authors.forename: Toru
authors.initials: T
authors.lastname: Nakazawa
authors.forename: Shoji
authors.initials: S
authors.lastname: Notomi
authors.forename: Edward
authors.initials: E
authors.lastname: Connolly
authors.forename: Haicheng
authors.initials: H
authors.lastname: She
authors.forename: Lama
authors.initials: L
authors.lastname: Almulki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ito
authors.forename: Demetrios G
authors.initials: DG
authors.lastname: Vavvas
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Ishibashi
authors.forename: Joan W
authors.initials: JW
authors.lastname: Miller
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D051033:Apoptosis Inducing Factor / Q000172:deficiency / Q000502:physiology*; D016026:Bone Marrow Transplantation / Q000379:methods; D002829:Choroid / Q000293:injuries / Q000648:ultrastructure; D020256:Choroidal Neovascularization / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D016510:Corneal Neovascularization / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology*; D042783:Endothelial Cells / Q000473:pathology; D004730:Endothelium, Vascular / Q000473:pathology; D005451:Fluorescein Angiography; D007834:Lasers; D007962:Leukocytes / Q000473:pathology; D017737:Macrophages, Peritoneal / Q000473:pathology; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D042461:Vascular Endothelial Growth Factor A
chemical_list: D051033:Apoptosis Inducing Factor; C494830:AIFM1 protein, mouse; D042461:Vascular Endothelial Growth Factor A