title: Optical imaging of mitochondrial redox state in rodent model of retinitis pigmentosa.
abstract: Oxidative stress (OS) and mitochondrial dysfunction contribute to photoreceptor cell loss in retinal degenerative disorders. The metabolic state of the retina in a rodent model of retinitis pigmentosa (RP) was investigated using a cryo-fluorescence imaging technique. The mitochondrial metabolic coenzymes nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) are autofluorescent and can be monitored without exogenous labels using optical techniques. The cryo-fluorescence redox imaging technique provides a quantitative assessment of the metabolism. More specifically, the ratio of the fluorescence intensity of these fluorophores (NADH/FAD), the NADH redox ratio (RR), is a marker of the metabolic state of the tissue. The NADH RR and retinal function were examined in an established rodent model of RP, the P23H rat compared to that of nondystrophic Sprague-Dawley (SD) rats. The NADH RR mean values were 1.11 ± 0.03 in the SD normal and 0.841 ± 0.01 in the P23H retina, indicating increased OS in the P23H retina. Electroretinographic data revealed a significant reduction in photoreceptor function in P23H animals compared to SD nozrmal rats. Thus, cryo-fluorescence redox imaging was used as a quantitative marker of OS in eyes from transgenic rats and demonstrated that alterations in the oxidative state of eyes occur during the early stages of RP.
authors.affiliation: University of Wisconsin Milwaukee, Biophotonics Lab, Department of Electrical engineering, 3200 N Cramer Street, Milwaukee, Wisconsin 53211, USA.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Maleki
authors.forename: Sandeep
authors.initials: S
authors.lastname: Gopalakrishnan
authors.forename: Zahra
authors.initials: Z
authors.lastname: Ghanian
authors.forename: Reyhaneh
authors.initials: R
authors.lastname: Sepehr
authors.forename: Heather
authors.initials: H
authors.lastname: Schmitt
authors.forename: Janis
authors.initials: J
authors.lastname: Eells
authors.forename: Mahsa
authors.initials: M
authors.lastname: Ranji
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004195:Disease Models, Animal; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008928:Mitochondria / Q000378:metabolism* / Q000473:pathology; D009243:NAD / Q000378:metabolism; D061848:Optical Imaging / Q000379:methods*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D055647:Rats, Transgenic; D012174:Retinitis Pigmentosa / Q000378:metabolism* / Q000473:pathology
chemical_list: D009243:NAD