Abstract
Purpose: :
We recently reported adiponectin (APN) peptide (NH2- KDKAVLFTYDQYQEKNVD-COOH) inhibits laser induced choroidal neovascularization (CNV) and decreases VEGF expression in mouse model of CNV. The aim of this study was to test an effect of APN peptide on CNV in Brown Norway rats and to investigate expression of VEGF, VEGF receptor 1 and 2 in choroid and retina.
Methods: :
CNV was induced in male Brown Norway rats with Argon laser. APN peptide was injected intraperitoneally. We used tissue samples of choroids and retinas at 3rd, 7th and 10th day after laser. Choroid-scleral flat mounts were investigated after animal FITC-dextran perfusion with laser confocal microscope. Histological and immunohistochemical studies for VEGF, VEGFR1 and VEGFR2 were performed. Vessels in CNV were detected and counted by histological examination and after immunohistochemical staining for Von Willebrand Factor VIII (vWF). VEGF, VEGFR1 and VEGFR2 RNA expression in choroids and retinas was investigated by RT-PCR.
Results: :
APN peptide decreased CNV area and number of vWF positive vessels in area of CNV by 50%. VEGF expression in retina and choroid increased slightly at day 3 then started decreasing from day 7 and dramatically decreased on day 10 after laser. VEGF receptors 1 and 2 had different dynamics of changes. VEGFR1 and 2 increased slightly on day 3 in some retinal structures. However, the expression of VEGFR1 decreased from day 7 to day 10 after laser. At the same time VEGFR2 expression did not change on day 7 but decreased in retina and choroid on day 10.
Conclusions: :
APN peptide (NH2- KDKAVLFTYDQYQEKNVD-COOH) inhibits CNV formation in rat model of CNV. Decreasing of VEGF ant its receptors 1 and 2 expression in retina and choroid plays a central role in CNV inhibition. APN peptide may have therapeutic use for AMD treatment however further investigations will be needed for clinical application of this peptide.
Keywords: age-related macular degeneration • pathology: experimental