Propionate hampers differentiation and modifies histone propionylation and acetylation in skeletal muscle cells

Bart Lagerwaard,Marjanne D Van Der Hoek,Joris Hoeks,Lotte Grevendonk,Arie G Nieuwenhuizen,Jaap Keijer,Vincent C.J De Boer

doi:10.1016/j.mad.2021.111495

Abstract

Protein acylation via metabolic acyl-CoA intermediates provides a link between cellular metabolism and protein functionality. A process in which acetyl-CoA and acetylation are fine-tuned is during myogenic differentiation. However, the roles of other protein acylations remain unknown. Protein propionylation could be functionally relevant because propionyl-CoA can be derived from the catabolism of amino acids and fatty acids and was shown to decrease during muscle differentiation. We aimed to explore the potential role of protein propionylation in muscle differentiation, by mimicking a pathophysiological situation with high extracellular propionate which increases propionyl-CoA and protein propionylation, rendering it a model to study increased protein propionylation. Exposure to extracellular propionate, but not acetate, impaired myogenic differentiation in C2C12 cells and propionate exposure impaired myogenic differentiation in primary human muscle cells. Impaired differentiation was accompanied by an increase in histone propionylation as well as histone acetylation. Furthermore, chromatin immunoprecipitation showed increased histone propionylation at specific regulatory myogenic differentiation sites of the Myod gene. Intramuscular propionylcarnitine levels are higher in old compared to young males and females, possibly indicating increased propionyl-CoA levels with age. The findings suggest a role for propionylation and propionyl-CoA in regulation of muscle cell differentiation and ageing, possibly via alterations in histone acylation.

Highlights

Post translational modifications of proteins by intermediates of metabolism offers the cell a rapid and integrated mechanism to respond to changes in nutrient availability and adjust consequent cellular de cisions
To analyse whether propionyl-CoA-derived protein propionylation could play a role in muscle physiology, we first exposed C2C12 myo blasts to 4 mM extracellular propionate, an exposure that is comparable to patients in propionic acidaemia, which was previously shown to induce intracellular protein propionylation (Hommes et al, 1968; Lagerwaard et al, 2020)
Immunofluorescence analysis of skeletal myosin heavy chain (MHC), a protein marker exclusively expressed in differentiated myotubes, demonstrated that MHC signals were almost absent in the propionate condition compared to the control and the acetate condition (Fig. 1C), indicating that pro pionate, but not acetate, inhibited differentiation of myoblasts into myotubes

Summary

Introduction

Post translational modifications of proteins by intermediates of metabolism offers the cell a rapid and integrated mechanism to respond to changes in nutrient availability and adjust consequent cellular de cisions. Acetylation of histone proteins serves an important cause as it regulates gene transcription by remodelling of chromatin structure (Sabari et al, 2016). In this way, protein acetylation functions as a metabolic sensor, as it was shown that acetyl-CoA levels are directly linked to acetylation of histone proteins associated with cell growth and proliferation genes (Cai et al, 2011; Wellen et al, 2009). Depleting acetyl-CoA as substrate for acetylation by silencing of the ATP-citrate lyase (ACL) enzyme, resulted in a failed response to upregulate MYOD expression and impaired myogenic differentiation, demonstrating the central role of acetylation in this process (Das et al, 2017)

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