MG132-induced progerin clearance is mediated by autophagy activation and splicing regulation

Karim Harhouri (1) , Claire L. Navarro (1) , Danielle Depetris (1) , Marie-Genevieve Mattei (1) , Xavier Nissan (2) , Pierre Cau (1) , Annachiara de Sandre-Giovannoli (1, 3) , Nicolas Levy (1, 3)

1 GMGF - Génétique Médicale et Génomique Fonctionnelle
2 I-STEM - Institut des cellules souches pour le traitement et l'étude des maladies monogéniques
3 Département de génétique médicale [Hôpital de la Timone - APHM]

Hutchinson-Gilford progeria syndrome (HGPS) is a lethal premature and accelerated aging disease caused by a de novo point mutation in LMNA encoding A-type lamins. Progerin, a truncated and toxic prelamin A issued from aberrant splicing, accumulates in HGPS cells' nuclei and is a hallmark of the disease. Small amounts of progerin are also produced during normal aging. We show that progerin is sequestered into abnormally shaped promyelocytic nuclear bodies, identified as novel biomarkers in late passage HGPS cell lines. We found that the proteasome inhibitor MG132 induces progerin degradation through macroautophagy and strongly reduces progerin production through downregulation of SRSF-1 and SRSF-5 accumulation, controlling prelamin A mRNA aberrant splicing. MG132 treatment improves cellular HGPS phenotypes. MG132 injection in skeletal muscle of LmnaG609G/G609G mice locally reduces SRSF-1 expression and progerin levels. Altogether, we demonstrate progerin reduction based on MG132 dual action and shed light on a promising class of molecules toward a potential therapy for children with HGPS.

Mots clés: autophagy; MG132; PML-NBs; progerin; splicing

Domaines: Biochimie, Biologie Moléculaire

Karim Harhouri, Claire L. Navarro, Danielle Depetris, Marie-Genevieve Mattei, Xavier Nissan, et al.. MG132-induced progerin clearance is mediated by autophagy activation and splicing regulation. EMBO Molecular Medicine, 2017, 9 (9), pp.1294-1313. ⟨10.15252/emmm.201607315⟩. ⟨hal-01741719⟩