title: Pharmacologic and genetic manipulation of MMP-2 and -9 affects retinal neovascularization in rodent models of OIR.
abstract: OBJECTIVE
  The efficacy of three matrix metalloproteinase (MMP) inhibitors with various selectivities (Ro-31-9790, AG3340, and DPC-A37668) was investigated in a rat model of retinopathy of prematurity, to examine the roles of MMP-2 and -9 in retinal neovascularization. The susceptibilities of MMP-2(-/-) and -9(-/-) mice to preretinal neovascularization were investigated in a mouse model of oxygen-induced retinopathy.
  
  
  METHODS
  Sprague-Dawley newborn rats were exposed to alternating episodes of 50% and 10% oxygen (variable oxygen exposure) to induce retinal neovascularization. Three MMP inhibitors with various selectivity profiles were administered to variable oxygen-exposed rats via local or systemic routes. Antineovascular efficacy was determined in drug-treated versus vehicle-treated rat pups by computerized imaging of adenosine diphosphatase (ADPase)-stained retinal flatmounts. Wild-type C57BL/6J and isogenic MMP-2(-/-) and -9(-/-) mice were exposed to 75% oxygen followed by normoxia. The mice were killed immediately before or after the normoxic exposure, and eyes were either harvested for retinal dissection and flatmounting or were paraffin embedded and sectioned. Retinal vascular area and retinal neovascularization were assessed by adenosine diphosphatase staining of retinal flatmounts and by counting preretinal nuclei of hematoxylin and eosin-stained retinal sections, respectively.
  
  
  RESULTS
  Ro-31-9790, AG3340, and DPC-A37668 had no effect on normal development of the rat retinal vasculature, regardless of dose or route of administration. Intravitreal injection of Ro-31-9790 (broad-spectrum) immediately after variable-oxygen exposure and 2 days after exposure resulted in 78% and 82% inhibition of retinal neovascularization, respectively. AG3340 (MMP-2- and -9-selective inhibitor) and DPC-A37668 (MMP-2-selective inhibitor) resulted in 65% and 52% inhibition, respectively, when administered by intravitreal injection immediately after variable-oxygen exposure. Intraperitoneal injection of 5, 15, and 50 mg/mL AG3340 or DPC-A37668 for 6 days after variable oxygen exposure resulted in 22% to 39% and 0% to 31% inhibition of neovascularization, respectively. AG3340 and DPC-A37668 administered by oral gavage at doses of 3, 10, or 30 mg/mL provided up to 42% and 86% inhibition of neovascularization, respectively. The average vascular areas of retinas from MMP-2(-/-) or -9(-/-) mice at postnatal day 12 were not significantly different from the wild-type control. There was a 75% (P < 0.001) and 44% (P < 0.01) reduction in preretinal neovascularization in oxygen-exposed MMP-2(-/-) and -9(-/-) mice at postnatal day 19, respectively, compared with wild-type control mice.
  
  
  CONCLUSIONS
  The results of this study suggest that MMP-2 plays a predominant role in retinal angiogenesis in both the mouse and rat models of oxygen-induced retinopathy. Furthermore, MMP-2 inhibition may be a viable therapeutic approach for ocular diseases characterized by retinal neovascularization.
authors.affiliation: Vanderbilt Eye Institute, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Barnett
authors.forename: Gary W
authors.initials: GW
authors.lastname: McCollum
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Fowler
authors.forename: James J-W
authors.initials: JJ
authors.lastname: Duan
authors.forename: Jesse D
authors.initials: JD
authors.lastname: Kay
authors.forename: Rui-Qin
authors.initials: RQ
authors.lastname: Liu
authors.forename: David P
authors.initials: DP
authors.lastname: Bingaman
authors.forename: John S
authors.initials: JS
authors.lastname: Penn
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001081:Apyrase / Q000378:metabolism; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D020868:Gene Silencing / Q000502:physiology*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D007231:Infant, Newborn; D007267:Injections; D020778:Matrix Metalloproteinase 2 / Q000502:physiology*; D020780:Matrix Metalloproteinase 9 / Q000502:physiology*; D061965:Matrix Metalloproteinase Inhibitors; D051379:Mice; D008810:Mice, Inbred C57BL; D009930:Organic Chemicals / Q000494:pharmacology; D010100:Oxygen / Q000633:toxicity; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000201:enzymology; D015861:Retinal Neovascularization / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D012178:Retinopathy of Prematurity / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D014822:Vitreous Body
chemical_list: C517488:DPC-A37668; D004791:Enzyme Inhibitors; D006877:Hydroxamic Acids; D061965:Matrix Metalloproteinase Inhibitors; D009930:Organic Chemicals; D011725:Pyridines; C097661:Ro 31-9790; C113282:prinomastat; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D001081:Apyrase; D010100:Oxygen