title: Intravitreal inhibition of complement C5a reduces choroidal neovascularization in mice.
abstract: OBJECTIVE
  To investigate the influence of complement component C5a inhibition on laser-induced choroidal neovascularization (CNV) in mice using a C5a specific L-aptamer.
  
  
  METHODS
  In C57BL/6 J mice CNV was induced by argon-laser, C5a-inhibitor (NOX-D20) was intravitreally injected in three concentrations: 0.3, 3.0, and 30 mg/ml. The unPEGylated derivate (NOX-D20001) was applied at 3.0 mg/ml; the vehicle (5 % glucose) was injected in controls. Vascular leakage was evaluated using fluorescence angiography, CNV area was examined immunohistochemically. Activated immune cells surrounding the CNV lesion and potential cytotoxicity were analyzed.
  
  
  RESULTS
  Compared to controls, CNV areas were significantly reduced after NOX-D20 injection at a concentration of 0.3 and 3.0 mg/ml (p = 0.042; p = 0.016). NOX-D20001 significantly decreased CNV leakage but not the area (p = 0.007; p = 0.276). At a concentration of 30 mg/ml, NOX-D20 did not reveal significant effects on vascular leakage or CNV area (p = 0.624; p = 0.121). The amount of CD11b positive cells was significantly reduced after treatment with 0.3 and 3.0 mg/ml NOX-D20 (p = 0.027; p = 0.002). No adverse glial cell proliferation or increased apoptosis were observed at effective dosages.
  
  
  CONCLUSIONS
  Our findings demonstrate that the targeted inhibition of complement component C5a reduces vascular leakage and neovascular area in laser-induced CNV in mice. NOX-D20 was proven to be an effective and safe agent that might be considered as a therapeutic candidate for CNV treatment. The deficiency of activated immune cells highlights promising new aspects in the pathology of choroidal neovascularization, and warrants further investigations.
authors.affiliation: Department of Ophthalmology, Charité - University Medicine Berlin, Augustenburger Platz 1, 13353, Berlin, Germany. claudia.brockmann@charite.de.
authors.forename: Claudia
authors.initials: C
authors.lastname: Brockmann
authors.affiliation: Department of Ophthalmology, Charité - University Medicine Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Brockmann
authors.affiliation: Department of Ophthalmology, Charité - University Medicine Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Dege
authors.affiliation: Department of Ophthalmology, Charité - University Medicine Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Catharina
authors.initials: C
authors.lastname: Busch
authors.affiliation: Department of Ophthalmology, Charité - University Medicine Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Kociok
authors.affiliation: NOXXON Pharma AG, Max-Dohrn-Strasse 8-10, 10589, Berlin, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Vater
authors.affiliation: NOXXON Pharma AG, Max-Dohrn-Strasse 8-10, 10589, Berlin, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Klussmann
authors.affiliation: Department of Ophthalmology, Charité - University Medicine Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Olaf
authors.initials: O
authors.lastname: Strauß
authors.affiliation: Department of Ophthalmology, Charité - University Medicine Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Joussen
mesh_terms: D000818:Animals; D017209:Apoptosis; D052157:Aptamers, Nucleotide / Q000009:adverse effects / Q000627:therapeutic use*; D002199:Capillary Permeability / Q000187:drug effects; D020256:Choroidal Neovascularization / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D015936:Complement C5a / Q000037:antagonists & inhibitors*; D004195:Disease Models, Animal; D005451:Fluorescein Angiography; D015726:Giant Cells / Q000473:pathology; D007150:Immunohistochemistry; D058449:Intravitreal Injections; D007962:Leukocytes / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D012697:Serine Endopeptidases / Q000009:adverse effects / Q000627:therapeutic use*; D014822:Vitreous Body / Q000378:metabolism
chemical_list: D052157:Aptamers, Nucleotide; C000589815:NOX-D20; C041833:complement C5a-inhibitors; D015936:Complement C5a; D012697:Serine Endopeptidases
keywords: C5a inhibition; Complement component C5a; Complement system; Intravitreal injection; L-aptamer; Laser-induced neovascularization; Spiegelmer