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Publication Exonic SINE Insertion in STK38L Causes Canine Early Retinal Degeneration (erd)(2010-12-01) Goldstein, Orly; Aguirre, Gustavo D; Kukekova, Anna V; Acland, Gregory MFine mapping followed by candidate gene analysis of erd — a canine hereditary retinal degeneration characterized by aberrant photoreceptor development — established that the disease cosegregates with a SINE insertion in exon 4 of the canine STK38L/NDR2 gene. The mutation removes exon 4 from STK38L transcripts and is predicted to remove much of the N terminus from the translated protein, including binding sites for S100B and Mob proteins, part of the protein kinase domain, and a Thr-75 residue critical for autophosphorylation. Although known to have roles in neuronal cell function, the STK38L pathway has not previously been implicated in normal or abnormal photoreceptor development. Loss of STK38L function in erd provides novel potential insights into the role of the STK38L pathway in neuronal and photoreceptor cell function, and suggests that genes in this pathway need to be considered as candidate genes for hereditary retinal degenerations.Publication Exploring Human/Animal Intersections: Converging Lines of Evidence in Comparative Models of Aging(2008-01-01) Trojanowski, John Q; Aguirre, Gustavo D; Jedrziewski, Kathryn; Johnson, F. Brad; Hess, Rebecka S; Cancro, Michael P; Sleeper, Margaret M; Pignolo, Robert; Lee, Virginia Man-Yee; Hendricks, Joan C; Pack, Allan I; Davies, Peter F; Michel, Kathryn E; Teff, Karen L; Lawler, Dennis FAt a symposium convened on March 8, 2007 by the Institute on Aging at the University of Pennsylvania, researchers from the University’s Schools of Medicine and Veterinary Medicine explored the convergence of aging research emerging from the two schools. Studies in human patients, animal models, and companion animals have revealed different but complementary aspects of the aging process, ranging from fundamental biologic aspects of aging to the treatment of age-related diseases, both experimentally and in clinical practice. Participants concluded that neither animal nor human research alone will provide answers to most questions about the aging process. Instead, an optimal translational research model supports a bidirectional flow of information from animal models to clinical research.Publication Identical Mutation in a Novel Retinal Gene Causes Progressive Rod-Cone Degeneration in Dogs and Retinitis Pigmentosa in Humans(2006-11-01) Zangerl, Barbara; Aguirre, Gustavo D; Goldstein, Orly; Philip, Alisdair R; Lindauer, Sarah J. P; Pearce-Kelling, Susan E; Mullins, Roberts F; Graphodatsky, Alexander S; Ripoll, Daniel; Felix, Jeanette S; Stone, Edwin M; Acland, Gregory MProgressive rod–cone degeneration (prcd) is a late-onset, autosomal recessive photoreceptor degeneration of dogs and a homolog for some forms of human retinitis pigmentosa (RP). Previously, the disease-relevant interval was reduced to a 106-kb region on CFA9, and a common phenotype-specific haplotype was identified in all affected dogs from several different breeds and breed varieties. Screening of a canine retinal EST library identified partial cDNAs for novel candidate genes in the disease-relevant interval. The complete cDNA of one of these, PRCD, was cloned in dog, human, and mouse. The gene codes for a 54-amino-acid (aa) protein in dog and human and a 53-aa protein in the mouse; the first 24 aa, coded for by exon 1, are highly conserved in 14 vertebrate species. A homozygous mutation (TGC → TAC) in the second codon shows complete concordance with the disorder in 18 different dog breeds/breed varieties tested. The same homozygous mutation was identified in a human patient from Bangladesh with autosomal recessive RP. Expression studies support the predominant expression of this gene in the retina, with equal expression in the retinal pigment epithelium, photoreceptor, and ganglion cell layers. This study provides strong evidence that a mutation in the novel gene PRCD is the cause of autosomal recessive retinal degeneration in both dogs and humans.Publication Linkage Disequilibrium Mapping in Domestic Dog Breeds Narrows the Progressive Rod-Cone Degeneration Interval and Identifies Ancestral Disease-Transmitting Chromosome(2006-11-01) Zangerl, Barbara; Aguirre, Gustavo D; Goldstein, Orly; Pearce-Kelling, Sue; Sidjanin, Duska J; Kijas, James W; Felix, Jeanette; Acland, Gregory MCanine progressive rod–cone degeneration (prcd) is a retinal disease previously mapped to a broad, gene-rich centromeric region of canine chromosome 9. As allelic disorders are present in multiple breeds, we used linkage disequilibrium (LD) to narrow the ∼6.4-Mb interval candidate region. Multiple dog breeds, each representing genetically isolated populations, were typed for SNPs and other polymorphisms identified from BACs. The candidate region was initially localized to a 1.5-Mb zero recombination interval between growth factor receptor-bound protein 2 (GRB2) and SEC14-like 1 (SEC14L). A fine-scale haplotype of the region was developed, which reduced the LD interval to 106 kb and identified a conserved haplotype of 98 polymorphisms present in all prcd-affected chromosomes from 14 different dog breeds. The findings strongly suggest that a common ancestor transmitted the prcd disease allele to many of the modern dog breeds and demonstrate the power of the LD approach in the canine model.Publication rAAV2/5 Gene-Targeting to Rods: Dose-Dependent Efficiency and Complications Associated With Different Promoters(2010-09-01) Beltran, William; Aguirre, Gustavo D; Boye, Sanford L; Boye, Shannon E; Chiodo, Vince A; Lewin, Alfred S; Hauswirth, William WA prerequisite for using corrective gene therapy to treat humans with inherited retinal degenerative diseases that primarily affect rods is to develop viral vectors that target specifically this population of photoreceptors. The delivery of a viral vector with photoreceptor tropism coupled with a rod-specific promoter is likely to be the safest and most efficient approach to target expression of the therapeutic gene to rods. Three promoters that included a fragment of the proximal mouse opsin promoter (mOP), the human G-protein-coupled receptor protein kinase 1 promoter (hGRK1), or the cytomegalovirus immediate early enhancer combined with the chicken β actin proximal promoter CBA were evaluated for their specificity and robustness in driving GFP reporter gene expression in rods, when packaged in a recombinant adeno-associated viral vector of serotype 2/5 (AAV2/5), and delivered via subretinal injection to the normal canine retina. Photoreceptor-specific promoters (mOP, hGRK1) targeted robust GFP expression to rods, whereas the ubiquitously expressed CBA promoter led to transgene expression in the retinal pigment epithelium, rods, cones and rare Müller, horizontal and ganglion cells. Late onset inflammation was frequently observed both clinically and histologically with all three constructs when the highest viral titers were injected. Cone loss in the injected regions of the retinas that received the highest titers occurred with both the hGRK1 and CBA promoters. Efficient and specific rod transduction, together with preservation of retinal structure was achieved with both mOP and hGRK1 promoters when viral titers in the order of 1011 vg ml–1 were used.Publication Long-Term Restoration of Rod and Cone Vision by Single Dose rAAV-Mediated Gene Transfer to the Retina in a Canine Model of Childhood Blindness(2005-12-01) Aguirre, Gustavo D; Acland, Gregory M; Cideciyan, Artur V; Bennett, Jean; Bennicelli, Jeannette; Dejneka, Nadine S; Pearce-Kelling, Susan E; Jacobson, Samuel G; Maguire, Albert M; Palczewski, Krzysztof; Hauswirth, William WThe short- and long-term effects of gene therapy using AAV-mediated RPE65 transfer to canine retinal pigment epithelium were investigated in dogs affected with disease caused by RPE65 deficiency. Results with AAV 2/2, 2/1, and 2/5 vector pseudotypes, human or canine RPE65 cDNA, and constitutive or tissue-specific promoters were similar. Subretinally administered vectors restored retinal function in 23 of 26 eyes, but intravitreal injections consistently did not. Photoreceptoral and postreceptoral function in both rod and cone systems improved with therapy. In dogs followed electroretinographically for 3 years, responses remained stable. Biochemical analysis of retinal retinoids indicates that mutant dogs have no detectable 11-cis-retinal, but markedly elevated retinyl esters. Subretinal AAV-RPE65 treatment resulted in detectable 11-cis-retinal expression, limited to treated areas. RPE65 protein expression was limited to retinal pigment epithelium of treated areas. Subretinal AAV-RPE65 vector is well tolerated and does not elicit high antibody levels to the vector or the protein in ocular fluids or serum. In long-term studies, wild-type cDNA is expressed only in target cells. Successful, stable restoration of rod and cone photoreceptor function in these dogs has important implications for treatment of human patients affected with Leber congenital amaurosis caused by RPE65 mutations.Publication Targeting Gene Expression to Cones With Human Cone Opsin Promoters in Recombinant AAV(2008-07-01) Komáromy, András M; Aguirre, Gustavo D; Alexander, John J; Cooper, Anne E; Chodo, Vince A; Acland, Gregory M; Hauswirth, William WSpecific cone-directed therapy is of high priority in the treatment of human hereditary retinal diseases. However, not much information exists about the specific targeting of photoreceptor subclasses. Three versions of the human red cone opsin promoter (PR0.5, 3LCR-PR0.5 and PR2.1), and the human blue cone opsin promoter HB569, were evaluated for their specificity and robustness in targeting green fluorescent protein (GFP) gene expression to subclasses of cones in the canine retina when used in recombinant adeno-associated viral vectors of serotype 5. The vectors were administered by subretinal injection. The promoter PR2.1 led to most effective and specific expression of GFP in the long- and medium-wavelength-absorbing cones (L/M cones) of normal and diseased retinas. The PR0.5 promoter was not effective. Adding three copies of the 35-bp LCR in front of PR0.5 lead to weak GFP expression in L/M cones. The HB569 promoter was not specific, and GFP was expressed in a few L/M cones, some rods and the retinal pigment epithelium. These results suggest that L/M cones, the predominant class of cone photoreceptors in the retinas of dogs and most mammalian species can be successfully targeted using the human red cone opsin promoter.Publication Blinded by the Light: Retinal Phototoxicity in the Context of Safety Studies(2013-08-01) De Vera Mudry, Maria Cristina; Aguirre, Gustavo D; Kronenberg, Sven; Komatsu, Shun-ichiroPublication Overexpression of SERCA1a in the mdx Diaphragm Reduces Susceptibility to Contraction-Induced Damage(2010-12-10) Sleeper, Margaret M; Barton, Elisabeth R; Morine, Kevin J; Sweeney, H. LeeAlthough the precise pathophysiological mechanism of muscle damage in dystrophin-deficient muscle remains disputed, calcium appears to be a critical mediator of the dystrophic process. Duchenne muscular dystrophy patients and mouse models of dystrophin deficiency exhibit extensive abnormalities of calcium homeostasis, which we hypothesized would be mitigated by increased expression of the sarcoplasmic reticulum calcium pump. Neonatal adeno-associated virus gene transfer of sarcoplasmic reticulum ATPase 1a to the mdx diaphragm decreased centrally located nuclei and resulted in reduced susceptibility to eccentric contraction-induced damage at 6 months of age. As the diaphragm is the mouse muscle most representative of human disease, these results provide impetus for further investigation of therapeutic strategies aimed at enhanced cytosolic calcium removal.Publication Canine RD3 Mutation Establishes Rod-Cone Dysplasia Type 2 (rcd2) as Ortholog of Human and Murine rd3(2009-02-01) Kukekova, Anna V; Aguirre, Gustavo D; Goldstein, Orly; Johnson, Jennifer L; Richardson, Malcolm A; Pearce-Kelling, Susan E; Swaroop, Anand; Friedman, James S; Acland, Gregory MRod-cone dysplasia type 2 (rcd2) is an autosomal recessive disorder that segregates in collie dogs. Linkage disequilibrium and meiotic linkage mapping were combined to take advantage of population structure within this breed and to fine map rcd2 to a 230-kb candidate region that included the gene C1orf36 responsible for human and murine rd3, and within which all affected dogs were homozygous for one haplotype. In one of three identified canine retinal RD3 splice variants, an insertion was found that cosegregates with rcd2 and is predicted to alter the last 61 codons of the normal open reading frame and further extend the open reading frame. Thus, combined meiotic linkage and LD mapping within a single canine breed can yield critical reduction of the disease interval when appropriate advantage is taken of within-breed population structure. This should permit a similar approach to tackle other hereditary traits that segregate in single closed populations.