Abstract
Purpose: :
A single nucleotide polymorphism (SNP) rs11200638 in the promoter of high temperature requirement factor A (HTRA1) at chromosome 10q26 has been shown to be strongly associated with age-related macular degeneration (AMD). Knockout mouse of Htra1 was characterized to determine whether lack of Htra1 expression can influence retinal function in mice.
Methods: :
Experimental study was performed on 12 month old Htra1deficient (-/-) mice and age matched control (+/+) mice. Fundus images were photographed using gonio lens and slit lamp (SR-D7, Topcon) with digital camera. Histological characterization by HE staining were performed. Full field flash electroretinogram (ERG) responses were recorded. Rod and cone contribution to the ERG responses were studied by analyzing the rod mixed and cone responses; flicker responses were also tested under dark or light adaptation.
Results: :
Fundus observation resulted with no difference between Htra1-/- and control mice retina. Histopathological examination by HE stain of the retina also showed no difference. Scotopic and photopic ERG responses (rod and mixed responses and oscillatory potentials) did not show any differences between Htra1-/- mice and control mice.
Conclusions: :
No significant physiological or histological effect by Htra1 expression deficiency was observed in the mouse retina. These observations are consistent with the previous reports showing increases Htra1 promoter activity by single nucleotide substitution in the promoter region of AMD patients.
Keywords: age-related macular degeneration