Dual Blockade of Misfolded Alpha-Sarcoglycan Degradation by Bortezomib and Givinostat Combination.

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. 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. 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. 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. Copyright © 2022 Hoch, Bourg, Degrugillier, Bruge, Benabides, Pellier, Tournois, Mahé, Maignan, Dawe, Georges, Papazian, Subramanian, Simon, Fanen, Delevoye, Richard and Nissan.

Citation

Lucile Hoch, Nathalie Bourg, Fanny Degrugillier, Céline Bruge, Manon Benabides, Emilie Pellier, Johana Tournois, Gurvan Mahé, Nicolas Maignan, Jack Dawe, Maxime Georges, David Papazian, Nik Subramanian, Stéphanie Simon, Pascale Fanen, Cédric Delevoye, Isabelle Richard, Xavier Nissan. Dual Blockade of Misfolded Alpha-Sarcoglycan Degradation by Bortezomib and Givinostat Combination. Frontiers in pharmacology. 2022;13:856804

PMID: 35571097

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