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Disrupting proteasomal and autophagic degradation systems of misfolded alpha-sarcoglycan protein by bortezomib and givinostat combination
  • +15
  • Lucile Hoch,
  • Nathalie Bourg,
  • Fanny Degrugillier,
  • Céline Bruge,
  • Manon Benabides,
  • Emilie Pellier,
  • Johana Tournois,
  • Gurvan Mahe,
  • Nicolas Maignan,
  • Jack Dawe,
  • Maxime Georges,
  • David Papazian,
  • Nik Subramanian,
  • Stéphanie Simon,
  • Pascale Fanen,
  • Cédric Delevoye,
  • Isabelle Richard,
  • Xavier Nissan
Lucile Hoch
I-Stem
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Nathalie Bourg
Genethon
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Fanny Degrugillier
University Paris-Est Créteil Val de Marne
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Céline Bruge
I-Stem
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Manon Benabides
I-Stem
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Emilie Pellier
I-Stem
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Johana Tournois
I-Stem
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Gurvan Mahe
I-Stem
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Nicolas Maignan
Kantify
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Jack Dawe
Kantify
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Maxime Georges
Kantify
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David Papazian
Kantify
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Nik Subramanian
Kantify
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Stéphanie Simon
University Paris-Est Créteil Val de Marne
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Pascale Fanen
INSERM
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Cédric Delevoye
Institut Curie
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Isabelle Richard
Genethon
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Xavier Nissan
I-Stem
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Abstract

Background and Purpose: Limb-girdle muscular dystrophy type R3 (LGMD R3) is a rare genetic disorder characterized by a progressive proximal muscle weakness and caused by mutations in the SGCA gene encoding alpha-sarcoglycan (α-SG). Here, we report the results of a mechanistic screening ascertaining the molecular mechanisms involved in the degradation of the most prevalent misfolded R77C-α-SG protein. Experimental Approach: We performed a combinatorial study to identify drugs potentializing the effect of a low dose of the proteasome inhibitor bortezomib on the R77C-α-SG degradation inhibition. Key Results: Analysis of the screening associated to artificial intelligence-based predictive ADMET characterization of the hits led to identification of the HDAC inhibitor givinostat as potential therapeutical candidate. Functional characterization revealed that givinostat effect was related to autophagic pathway inhibition, unveiling new theories concerning degradation pathways of misfolded SG proteins. Conclusion and Implications: Beyond the identification of a new therapeutic option for LGMD R3 patients, our results shed light on the potential repurposing of givinostat for the treatment of other genetic diseases sharing similar protein degradation defects such as LGMD R5 and cystic fibrosis.