RESUMO
A 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 ß 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 10(11)vg ml(-1) were used.
Assuntos
Dependovirus/genética , Terapia Genética/métodos , Regiões Promotoras Genéticas , Células Fotorreceptoras Retinianas Bastonetes/metabolismo , Actinas/genética , Actinas/metabolismo , Animais , Cães , Quinases de Receptores Acoplados a Proteína G/genética , Quinases de Receptores Acoplados a Proteína G/metabolismo , Genes Reporter/genética , Vetores Genéticos/genética , Humanos , Camundongos , TransfecçãoRESUMO
A 24-month-old female pug, which had previously been treated for visual hemifield loss, was referred with generalised seizures and other neurological disorders. A diagnosis of necrotising meningoencephalitis was suggested from the clinical signs together with the results of computed tomography and cerebrospinal fluid examination. This was confirmed seven months later by histological examination of the brain following euthanasia. Typical histopathological lesions of the disease were found in various areas of both cerebral hemispheres, including the visual striated cortex of the right cerebrum.
Assuntos
Encéfalo/patologia , Doenças do Cão/patologia , Meningoencefalite/veterinária , Animais , Doenças do Cão/diagnóstico , Cães , Feminino , Meningoencefalite/diagnóstico , Meningoencefalite/patologia , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVE: To characterize the flash electroretinogram (ERG) in the Golden Retriever muscular dystrophy (GRMD) dog and to compare the results with those from a control group of Golden Retrievers. To investigate whether similar abnormalities of the ERG as those found in a majority of human patients with Duchenne muscular dystrophy (DMD) are also observed in the GRMD dog, the canine model for DMD. Animals Five GRMD dogs and five age-matched clinically normal Golden Retrievers. PROCEDURE: An ophthalmic examination was carried out prior to performing electroretinography under general anesthesia. Rod, combined rod-cone and oscillatory potentials responses were recorded after dark adaptation. Responses to 30-Hz-flicker were recorded after light adaptation. The ERG responses of the GRMD dogs were compared with those of the control dogs by use of a Wilcoxon signed rank test. RESULTS: GRMD dogs had significantly reduced a and b-wave amplitudes after dim white flash stimuli (rod response) and reduced a-wave amplitude after bright white flash stimuli (rod-cone response). CONCLUSION AND CLINICAL RELEVANCE: The ERG abnormalities observed in the GRMD dog suggest a dysfunction in the rod signaling pathway. These ERG alterations are different from those observed in human patients with DMD.
Assuntos
Doenças do Cão/genética , Doenças do Cão/fisiopatologia , Distrofia Muscular Animal/genética , Distrofia Muscular Animal/fisiopatologia , Retina/fisiopatologia , Animais , Cruzamento , Estudos de Casos e Controles , Cães , Eletrorretinografia/veterinária , Predisposição Genética para Doença , Masculino , FenótipoRESUMO
A 7-and-a-half-year-old-dog was presented with progressive unilateral exophthalmos. Computed tomography imaging revealed an orbital mass that was surgically excised by lateral orbitotomy to preserve vision. The tumor was diagnosed histologically as a hemangiopericytoma. Twelve months postoperatively there were no signs of a local recurrence. This is the first case report of a hemangiopericytoma involving the orbit of a dog.