title: Agents that bind annexin A2 suppress ocular neovascularization.
abstract: TM601 is a synthetic polypeptide with sequence derived from the venom of the scorpion Leiurus quinquestriatus that has anti-neoplastic activity. It has recently been demonstrated to bind annexin A2 on cultured tumor and vascular endothelial cells and to suppress blood vessel growth on chick chorioallantoic membrane. In this study, we investigated the effects of TM601 in models of ocular neovascularization (NV). When administered by intraocular injection, intravenous injections, or periocular injections, TM601 significantly suppressed the development of choroidal NV at rupture sites in Bruch's membrane. Treatment of established choroidal NV with TM601 caused apoptosis of endothelial cells and regression of the NV. TM601 suppressed ischemia-induced and vascular endothelial growth factor-induced retinal NV and reduced excess vascular permeability induced by vascular endothelial growth factor. Immunostaining with an antibody directed against TM601 showed that after intraocular or periocular injection, TM601 selectively bound to choroidal or retinal NV and co-localized with annexin A2, which is undetectable in normal retinal and choroidal vessels, but is upregulated in endothelial cells participating in choroidal or retinal NV. Intraocular injection of plasminogen or tissue plasminogen activator, which like TM601 bind to annexin A2, also suppressed retinal NV. This study supports the hypothesis that annexin A2 is an important target for treatment of neovascular diseases and suggests that TM601, through its interaction with annexin A2, causes suppression and regression of ocular NV and reduces vascular leakage and thus may provide a new treatment for blinding diseases such as neovascular age-related macular degeneration and diabetic retinopathy.
authors.affiliation: Department of Ophthalmology and Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-9277, USA.
authors.forename: Raquel
authors.initials: R
authors.lastname: Lima e Silva
authors.forename: Jikui
authors.initials: J
authors.lastname: Shen
authors.forename: Yuan Yuan
authors.initials: YY
authors.lastname: Gong
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Seidel
authors.forename: Sean F
authors.initials: SF
authors.lastname: Hackett
authors.forename: Kamala
authors.initials: K
authors.lastname: Kesavan
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Jacoby
authors.forename: Peter A
authors.initials: PA
authors.lastname: Campochiaro
mesh_terms: D020533:Angiogenesis Inhibitors / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D017306:Annexin A2 / Q000378:metabolism*; D017209:Apoptosis / Q000187:drug effects; D016570:Bruch Membrane / Q000098:blood supply*; D002199:Capillary Permeability / Q000187:drug effects; D020256:Choroidal Neovascularization / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D005260:Female; D005341:Fibrinolysin / Q000008:administration & dosage; D006801:Humans; D007231:Infant, Newborn; D007275:Injections, Intravenous; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D011401:Promoter Regions, Genetic; D015861:Retinal Neovascularization / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D012171:Retinal Vessels / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D012178:Retinopathy of Prematurity / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D012243:Rhodopsin / Q000235:genetics; D012604:Scorpion Venoms / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis / Q000235:genetics
chemical_list: D020533:Angiogenesis Inhibitors; D017306:Annexin A2; D012604:Scorpion Venoms; D042461:Vascular Endothelial Growth Factor A; C091539:Chlorotoxin; D012243:Rhodopsin; D010959:Tissue Plasminogen Activator; D005341:Fibrinolysin