TY - JOUR
T1 - Gender and estrogen supplementation increases severity of experimental choroidal neovascularization
AU - Espinosa-Heidmann, Diego G.
AU - Marin-Castano, Maria E.
AU - Pereira-Simon, Simone
AU - Hernandez, Eleut P.
AU - Elliot, Sharon
AU - Cousins, Scott W.
N1 - Funding Information:
Supported by NIH grants EY/AI 13318 and RO1 EY 14477, and an unrestricted grant to prevent blindness, Inc.
PY - 2005/3
Y1 - 2005/3
N2 - Observational clinical studies suggest that post-menopausal women may be at risk for more severe age-related macular degeneration, and that estrogen loss due to menopause may contribute. We sought to determine the effect of gender and estrogen status on the severity of choroidal neovascularization (CNV) in a mouse model for experimental choroidal neovascularization. Laser-induced CNV was performed in mice with or without estrogen supplementation. At various times, eyes were removed for analysis of severity of CNV lesions or for extraction of choroidal mRNA to evaluate iNOS, TNF-α, MMP-9, and ER-α expression, which are molecules relevant to angiogenic processes. Also, splenic macrophages were analysed for iNOS to determine the effect of estrogen treatment in vitro. Finally, laser-induced CNV was performed in iNOS -/- mice. Our result showed that aged female mice had significantly larger CNV than age-matched males. Ovariectomy in adult mice did not increase severity, but paradoxically estrogen supplementation after ovariectomy did increase CNV severity. More severe CNV were associated with a significant decrease in choroidal iNOS mRNA. Splenic macrophages from estrogen supplemented mice showed a significant increased in TNF-α mRNA expression (eight fold difference compared to the control) but only a mild change in iNOS mRNA levels (2-3 fold difference). In vitro data further showed that nitric oxide production in splenic macrophages at different estrogen levels was not different from controls. Finally, CNV severity was significantly more severe in iNOS -/- mice, compared to iNOS +/+ mice after laser treatment. In conclusion, aged female mice developed more severe CNV than do males. Estrogen replacement seems to increase severity, possibly by suppressing the upregulation of choroidal iNOS and activating macrophages. The putative beneficial or detrimental role of estrogen biology in age-related macular degeneration must be more carefully evaluated and may vary with the stage of age-related macular degeneration (atrophic or neovascular) as well as with the specific target cell type (monocytes vs. endothelial cell or vascular smooth muscle cell).
AB - Observational clinical studies suggest that post-menopausal women may be at risk for more severe age-related macular degeneration, and that estrogen loss due to menopause may contribute. We sought to determine the effect of gender and estrogen status on the severity of choroidal neovascularization (CNV) in a mouse model for experimental choroidal neovascularization. Laser-induced CNV was performed in mice with or without estrogen supplementation. At various times, eyes were removed for analysis of severity of CNV lesions or for extraction of choroidal mRNA to evaluate iNOS, TNF-α, MMP-9, and ER-α expression, which are molecules relevant to angiogenic processes. Also, splenic macrophages were analysed for iNOS to determine the effect of estrogen treatment in vitro. Finally, laser-induced CNV was performed in iNOS -/- mice. Our result showed that aged female mice had significantly larger CNV than age-matched males. Ovariectomy in adult mice did not increase severity, but paradoxically estrogen supplementation after ovariectomy did increase CNV severity. More severe CNV were associated with a significant decrease in choroidal iNOS mRNA. Splenic macrophages from estrogen supplemented mice showed a significant increased in TNF-α mRNA expression (eight fold difference compared to the control) but only a mild change in iNOS mRNA levels (2-3 fold difference). In vitro data further showed that nitric oxide production in splenic macrophages at different estrogen levels was not different from controls. Finally, CNV severity was significantly more severe in iNOS -/- mice, compared to iNOS +/+ mice after laser treatment. In conclusion, aged female mice developed more severe CNV than do males. Estrogen replacement seems to increase severity, possibly by suppressing the upregulation of choroidal iNOS and activating macrophages. The putative beneficial or detrimental role of estrogen biology in age-related macular degeneration must be more carefully evaluated and may vary with the stage of age-related macular degeneration (atrophic or neovascular) as well as with the specific target cell type (monocytes vs. endothelial cell or vascular smooth muscle cell).
KW - Age-related macular degeneration (AMD)
KW - Animal model
KW - Choroidal neovascularisation (CNV)
KW - Estrogen
KW - Laser photocoagulation
KW - Macrophage activation
KW - iNOS
UR - http://www.scopus.com/inward/record.url?scp=13844266176&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=13844266176&partnerID=8YFLogxK
U2 - 10.1016/j.exer.2004.10.008
DO - 10.1016/j.exer.2004.10.008
M3 - Article
C2 - 15721623
AN - SCOPUS:13844266176
SN - 0014-4835
VL - 80
SP - 413
EP - 423
JO - Experimental Eye Research
JF - Experimental Eye Research
IS - 3
ER -