Abstract
Purpose: :
Usher syndrome is the leading cause of combined deafness and blindness. Patients with Usher I suffer retinitis pigmentosa beginning in early adolescence with congenital deafness and vestibular areflexia. The Ush1c216AA knock-in mice show a similar phenotype with retinal degeneration that begins after deafness. Abnormal electroretinograms in the mutant mice are evident as early as 1 month of age, however, the loss of rod photoreceptors begins between 6 and 12 months of age. Absent auditory-evoked brainstem responses between 3 weeks and 1 month of age indicate deafness at birth. The purpose of this study is to examine the retinal proteome in our knock-in mouse model containing the human USH1C216G>A mutation (216AA) over a one year time course.
Methods: :
Pooled retinas from three 216AA mutant males or females were compared with three pooled, age and sex-matched wild type controls, respectively, using 2-dimensional fluorescence differential gel electrophoresis followed by protein identification by matrix-assisted laser-desorption ionization time-of-flight mass spectrometry.
Results: :
At one year of age, there were 123 mutant protein spots that differed from their wild type age-and sex-matched littermates. All 123 spots were decreased in the mutant mice between 2 and 21 fold. Proteins decreased in the mutant belong to a diverse range of networks including intracellular transport, stress-response, and lipid metabolism. The protein spots with the highest fold changes (14 - 21 fold) are considered to be in the family of molecular chaperones with cell protective functions.
Conclusions: :
Ush1c216AA
Keywords: retinal degenerations: cell biology • proteomics • retina