Deacetylation Inhibition Reverses PABPN1-Dependent Muscle Wasting

Cyriel S Olie; Muhammad Riaz; Rebecca Konietzny; Philip D Charles; Adan Pinto-Fernandez; Szymon M Kiełbasa; A Aartsma-Rus; Jelle J Goeman; Benedikt M Kessler; Vered Raz

doi:10.1016/j.isci.2019.01.024

Deacetylation Inhibition Reverses PABPN1-Dependent Muscle Wasting

iScience. 2019 Feb 22:12:318-332. doi: 10.1016/j.isci.2019.01.024. Epub 2019 Jan 22.

Affiliations

¹ Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
² Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7FZ, UK.
³ Medical Statistics and Bioinformatics, Leiden University Medical Center, Leiden, The Netherlands.
⁴ Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: v.raz@lumc.nl.

Abstract

Reduced poly(A)-binding protein nuclear 1 (PABPN1) levels cause aging-associated muscle wasting. PABPN1 is a multifunctional regulator of mRNA processing. To elucidate the molecular mechanisms causing PABPN1-mediated muscle wasting, we compared the transcriptome with the proteome in mouse muscles expressing short hairpin RNA to PABPN1 (shPab). We found greater variations in the proteome than in mRNA expression profiles. Protein accumulation in the shPab proteome was concomitant with reduced proteasomal activity. Notably, protein acetylation appeared to be decreased in shPab versus control proteomes (63%). Acetylome profiling in shPab muscles revealed prominent peptide deacetylation associated with elevated sirtuin-1 (SIRT1) deacetylase. We show that SIRT1 mRNA levels are controlled by PABPN1 via alternative polyadenylation site utilization. Most importantly, SIRT1 deacetylase inhibition by sirtinol increased PABPN1 levels and reversed muscle wasting. We suggest that perturbation of a multifactorial regulatory loop involving PABPN1 and SIRT1 plays an imperative role in aging-associated muscle wasting. VIDEO ABSTRACT.

Keywords: Biological Sciences; Molecular Biology; Physiology.