Estrogens enhance myoblast differentiation in facioscapulohumeral muscular dystrophy by antagonizing DUX4 activity
Emanuela Teveroni, … , Giancarlo Deidda, Fabiola Moretti
Emanuela Teveroni, … , Giancarlo Deidda, Fabiola Moretti
Published March 6, 2017
Citation Information: J Clin Invest. 2017;127(4):1531-1545. https://doi.org/10.1172/JCI89401.
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Research Article Endocrinology Muscle biology Article has an altmetric score of 15

Estrogens enhance myoblast differentiation in facioscapulohumeral muscular dystrophy by antagonizing DUX4 activity

Abstract

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant neuromuscular disorder that is characterized by extreme variability in symptoms, with females being less severely affected than males and presenting a higher proportion of asymptomatic carriers. The sex-related factors involved in the disease are not known. Here, we have utilized myoblasts isolated from FSHD patients (FSHD myoblasts) to investigate the effect of estrogens on muscle properties. Our results demonstrated that estrogens counteract the differentiation impairment of FSHD myoblasts without affecting cell proliferation or survival. Estrogen effects are mediated by estrogen receptor β (ERβ), which reduces chromatin occupancy and transcriptional activity of double homeobox 4 (DUX4), a protein whose aberrant expression has been implicated in FSHD pathogenesis. During myoblast differentiation, we observed that the levels and activity of DUX4 increased progressively and were associated with its enhanced recruitment in the nucleus. ERβ interfered with this recruitment by relocalizing DUX4 in the cytoplasm. This work identifies estrogens as a potential disease modifier that underlie sex-related differences in FSHD by protecting against myoblast differentiation impairments in this disease.

Authors

Emanuela Teveroni, Marsha Pellegrino, Sabrina Sacconi, Patrizia Calandra, Isabella Cascino, Stefano Farioli-Vecchioli, Angela Puma, Matteo Garibaldi, Roberta Morosetti, Giorgio Tasca, Enzo Ricci, Carlo Pietro Trevisan, Giuliana Galluzzi, Alfredo Pontecorvi, Marco Crescenzi, Giancarlo Deidda, Fabiola Moretti

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Figure 9

Estrogens change intracellular localization of DUX4.

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Estrogens change intracellular localization of DUX4. (A) Western blot an...
(A) Western blot analysis of indicated proteins in the cytoplasmic (Cito) or chromatin-enriched fraction (chromatin) of immortalized control myoblasts overexpressing DUX4-V5 cultured in differentiation medium for 3 days (Diff. Myo) or in proliferation medium (Prol. Myo) in the absence (etOH) or presence of E2. See complete unedited blots in the supplemental material. (B) Quantification of DUX levels analyzed as in A. The signal of DUX4 in the absence of E2 was arbitrarily set to 1. Mean ± SD of 3 independent experiments is shown (n = 3). **P < 0.01, 1-sample t test. (C) Representative photographs of V5 immunostaining (green) in CTL#1 myoblasts overexpressing DUX-V5 during proliferation or differentiation at the indicated time points upon etOH or E2 treatment. Cytoplasm is marked by F-actin signal (red). DAPI counterstains nuclei (blue). Scale bar: 25 μm. (D) Percentages of DUX4 nuclear positive myoblasts treated as in C. Mean ± SD of 3 independent experiments is shown. Eight different fields/condition were counted (n = 24). ***P < 0.001, 2-tailed Student’s t test. (E) Representative photographs of endogenous DUX4 (green) and MHC (red) in primary FSHD#3 and FSHD#4 myoblasts cultured in differentiation medium for 4 days in the presence of etOH (FSHD#4) or E2 (middle panels, FSHD#4; lower panels, FSHD#3). DAPI counterstains nuclei (blue). Scale bar: 25 μm.