Matrix metalloproteinase (MMP) expression in experimental choroidal neovascularization.
OBJECTIVE
Matrix metalloproteinases (MMP) are a family of proteolytic enzymes that degrade basement membrane and extracellular matrix proteins. To gain information on the possible role of MMPs in choroidal neovascularization (CNV), we have analyzed the mRNA expression of MMP-2 and MMP-9, two forms of MMPs implicated in ocular neovascularization, in a rat model.


METHODS
Choroidal neovascularization was induced in pigmented rats by krypton laser photocoagulation of the fundus whereafter eyes were enucleated at 1, 3, 5, 7, 10 and 60 days. Antisense and sense riboprobes were generated using DNA complementary to MMP-2 and MMP-9, and mRNA expression was analyzed using in situ hybridization.


RESULTS
In the untreated eyes MMP-2 mRNA expression was weakly detected in cells within the choroid. In laser-treated eyes MMP-2 mRNA expression was markedly increased and mainly localized to macrophage-like and retinal pigment epithelial (RPE)-like cells invading the choroid, subretinal space and inner retina. This increase in MMP-2 mRNA expression peaked at day 10 whereafter a decline was detected. MMP-9 mRNA expression was low in untreated eyes and did not increase following laser treatment.


CONCLUSIONS
The results show that MMP-2 mRNA expression is increased in experimental CNV, and support of a role for MMP-2 in the development of CNV in age-related macular degeneration.
Kvanta
A
A
Department of Ophthalmology, St. Erik's Eye Hospital, Karolinska Institutet, Stockholm, Sweden. ankvanta@swipnet.se
Shen
W Y
WY
Sarman
S
S
Seregard
S
S
Steen
B
B
Rakoczy
E
E
D000818:Animals; D020256:Choroidal Neovascularization / Q000201:enzymology* / Q000473:pathology; D015342:DNA Probes; D004195:Disease Models, Animal; D005654:Fundus Oculi; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D017075:Laser Coagulation; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis / Q000235:genetics*; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D013997:Time Factors
D015342:DNA Probes; D012333:RNA, Messenger; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9