title: Loss of Raf-1 kinase inhibitory protein delays early-onset severe retinal ciliopathy in Cep290rd16 mouse.
abstract: OBJECTIVE
  Mutations in the cilia-centrosomal protein of centrosomal protein of 290 kDa (CEP290) result in severe ciliopathies, including autosomal recessive early onset childhood blindness disorder Leber congenital amaurosis (LCA). The Cep290(rd16) (retinal degeneration 16) mouse model of CEP290-LCA exhibits accumulation of CEP290-interacting protein Raf-1 kinase inhibitory protein (RKIP) prior to onset of retinal degeneration (by postnatal day P14). We hypothesized that reducing RKIP levels in the Cep290(rd16) mouse will delay or improve retinal phenotype.
  
  
  METHODS
  We generated double mutant mice by combining the Cep290(rd16) and Rkip(ko) alleles (Cep290(rd16):Rkip(+/ko) and Cep290(rd16):Rkip(ko/ko)). Retinal function was assessed by ERG and retinal morphology and protein trafficking were assessed by histology, transmission electron microscopy (TEM), and immunofluorescence analysis. Cell death was examined by apoptosis.
  
  
  RESULTS
  Prior to testing our hypothesis, we examined ERG and retinal morphology of Rkip(ko/ko) mice and did not find any detectable differences compared with wild-type mice. The Cep290(rd16):Rkip(+/ko) mice exhibited similar retinopathy as Cep290(rd16); however, Cep290(rd16): Rkip(ko/ko) double knockout mice demonstrated a substantial improvement (>9-fold) in photoreceptor function and structure at P18 as of Cep290(rd16) mice. We consistently detected transient preservation of photoreceptors at P18 and polarized trafficking of opsins to sensory cilia in the double mutant mice; however, retinal degeneration ensued by P30.
  
  
  CONCLUSIONS
  Our studies implicate CEP290-RKIP pathway in CEP290-retinal degeneration and suggest that targeting RKIP levels can delay photoreceptor degeneration, assisting in extending the time-window for treating such rapidly progressing blindness disorder.
authors.affiliation: Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts, United States.
authors.forename: Balajikarthick
authors.initials: B
authors.lastname: Subramanian
authors.affiliation: Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts, United States.
authors.forename: Manisha
authors.initials: M
authors.lastname: Anand
authors.affiliation: Department of Ophthalmology & Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States.
authors.forename: Naheed W
authors.initials: NW
authors.lastname: Khan
authors.affiliation: Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts, United States.
authors.forename: Hemant
authors.initials: H
authors.lastname: Khanna
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000951:Antigens, Neoplasm; D017209:Apoptosis / Q000502:physiology; D018797:Cell Cycle Proteins; D002924:Ciliary Body / Q000378:metabolism; D003598:Cytoskeletal Proteins; D004195:Disease Models, Animal; D004596:Electroretinography; D051379:Mice; D018345:Mice, Knockout; D009687:Nuclear Proteins; D055355:Opsins / Q000378:metabolism; D049488:Phosphatidylethanolamine Binding Protein / Q000172:deficiency / Q000502:physiology*; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology; D012162:Retinal Degeneration / Q000473:pathology / Q000503:physiopathology*
chemical_list: D000951:Antigens, Neoplasm; D018797:Cell Cycle Proteins; C513600:Cep290 protein, mouse; D003598:Cytoskeletal Proteins; D009687:Nuclear Proteins; D055355:Opsins; C511482:PEBP1 protein, human; D049488:Phosphatidylethanolamine Binding Protein
keywords: CEP290; RKIP; blindness; photoreceptor degeneration; retina