Activation of Bax in three models of retinitis pigmentosa.
Invest Ophthalmol Vis Sci
; 55(6): 3555-62, 2014 May 13.
Article
em En
| MEDLINE
| ID: mdl-24825107
ABSTRACT
PURPOSE:
The process of photoreceptor cell death in retinitis pigmentosa is still not well characterized, and identification of common mechanisms will be instrumental for development of therapeutic strategies. Here we investigated activation of Bax in rd1, P23H transgenic, and Rho knockout retinas.METHODS:
Bax activation was evaluated by immunofluorescence using anti-activated Bax-specific antibodies and by Western blotting on mitochondrial protein extracts. Knockdown of cathepsin D, calpain 1, and calpain 2 was achieved by short hairpin RNA (shRNA) delivery in rd1 mutant photoreceptors cells differentiated from retinal neurospheres. The mechanism of Bax activation through calpains was evaluated in vivo by intravitreal injection of calpastatin.RESULTS:
We defined activation and mitochondrial localization of Bax as well as activation of calpains and cathepsin D in the three models of retinitis pigmentosa. Taking advantage of an in vitro culture system for rd1 mutant photoreceptors, we unraveled the mechanism of Bax activation. We demonstrated that calpain 1 and cathepsin D contributed to activation of Bax and to apoptosis-inducing factor (Aif) nuclear translocation. In vivo interference with calpain activity blocks Bax activation in the rd1 and Rho knockout retinas and reduces activation in the P23H transgenic retina.CONCLUSIONS:
Activation of Bax was observed in all three models of retinitis pigmentosa and leads to neurodamage by localization at the mitochondrion. Our data suggest that Bax can be envisaged as one of the promising target molecules for restraining photoreceptor degeneration.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Ligação ao Cálcio
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RNA
/
Ativação Transcricional
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Retinose Pigmentar
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Células Fotorreceptoras de Vertebrados
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Proteína X Associada a bcl-2
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Invest Ophthalmol Vis Sci
Ano de publicação:
2014
Tipo de documento:
Article