MG132 induces progerin clearance and improves disease phenotypes in fibroblasts of patients affected with Hutchinson-Gilford Progeria-like syndromes

Abstract

Progeroid Syndromes (PS), including Hutchinson-Gilford Progeria Syndrome (HGPS, OMIM #176670), are premature and accelerated aging that clinically resemble some aspects of advancing physiological aging. Most classical HGPS patients carry a de novo point mutation within exon 11 of the LMNA gene encoding A-type Lamins. This mutation activates a cryptic splice site leading to the deletion of 50 amino acids at its carboxy-terminal domain, resulting in a truncated and permanently farnesylated Prelamin A called Prelamin A {Delta}50 or Progerin that accumulates in HGPS cell nuclei and is a hallmark of the disease. Some patients with PS carry other LMNA mutations affecting exon 11 splicing, leading to defects in nuclear A-type Lamins and are named "HGPS-like" patients. They also produce Progerin and/or other truncated Prelamin A isoforms ({Delta}35 and {Delta}90). We recently found that MG132, a proteasome inhibitor, induced progerin clearance in classical HGPS through autophagy activation and splicing regulation. Here, we show that MG132 induces aberrant prelamin A clearance and improves cellular phenotypes in HGPS-like patient cells. These results provide preclinical proof of principle for the use of a promising class of molecules toward a potential therapy for children with HGPS-like, who may therefore be eligible for inclusion in a therapeutic trial based on this approach, together with classical HGPS patients.