Rescue of Defective Electroretinographic Responses in Dp71-Null Mice With AAV-Mediated Reexpression of Dp71

Mirella Telles Salgueiro Barboni (1) , Cyrille Vaillend (2) , Anneka Joachimsthaler (3) , André Maurício Passos Liber (1) , Hanen Khabou (4) , Michel Roux (5) , Ophélie Vacca (2, 4) , Lucile Vignaud (4) , Deniz Dalkara (4) , Xavier Guillonneau (4) , Jan Kremers (3) , Dora Fix Ventura (1) , Alvaro Rendon (4)

1 USP - Universidade de São Paulo = University of São Paulo
2 NeuroPSI - Institut des Neurosciences Paris-Saclay
3 FAU - Friedrich-Alexander Universität Erlangen-Nürnberg = University of Erlangen-Nuremberg
4 Institut de la Vision
5 IGBMC - Institut de Génétique et de Biologie Moléculaire et Cellulaire

Purpose: To study the potential effect of a gene therapy, designed to rescue the expression of dystrophin Dp71 in the retinas of Dp71-null mice, on retinal physiology. Methods: We recorded electroretinograms (ERGs) in Dp71-null and wild-type littermate mice. In dark-adapted eyes, responses to flashes of several strengths were measured. In addition, flash responses on a 25-candela/square meters background were measured. On- and Off-mediated responses to sawtooth stimuli and responses to photopic sine-wave modulation (3-30 Hz) were also recorded. After establishing the ERG phenotype, the ShH10-GFP adeno-associated virus (AAV), which has been previously shown to target specifically Müller glial cells (MGCs), was delivered intravitreously with or without (sham therapy) the Dp71 coding sequence under control of a CBA promoter. ERG recordings were repeated three months after treatment. Real-time quantitative PCR and Western blotting analyses were performed in order to quantify Dp71 expression in the retinas. Results: Dp71-null mice displayed reduced b-waves in dark- and light-adapted flash ERGs and smaller response amplitudes to photopic rapid-on sawtooth modulation and to sine-wave stimuli. Three months after intravitreal injections of the ShH10-GFP-2A-Dp71 AAV vector, ERG responses were completely recovered in treated eyes of Dp71-null mice. The functional rescue was associated with an overexpression of Dp71 in treated retinas. Conclusions: The present results show successful functional recovery accompanying the reexpression of Dp71. In addition, this experimental model sheds light on MGCs influencing ERG components, since previous reports showed that aquaporin 4 and Kir4.1 channels were mislocated in MGCs of Dp71-null mice, while their distribution could be normalized following intravitreal delivery of the same ShH10-GFP-2A-Dp71 vector.

Mots clés: retina; Müller glial cells; electroretinogram; dystrophin; gene therapy

Domaines: Organes des sens; Neurobiologie; Génomique, Transcriptomique et Protéomique [q-bio.GN]; Sciences cognitives

Mirella Telles Salgueiro Barboni, Cyrille Vaillend, Anneka Joachimsthaler, André Maurício Passos Liber, Hanen Khabou, et al.. Rescue of Defective Electroretinographic Responses in Dp71-Null Mice With AAV-Mediated Reexpression of Dp71. Investigative Ophthalmology & Visual Science, 2020, 61 (2), pp.11. ⟨10.1167/iovs.61.2.11⟩. ⟨hal-02520616⟩