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 4

ERl3 mediates estrogen-enhanced differentiation.

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ERl3 mediates estrogen-enhanced differentiation. (A and B) mRNA levels b...
(A and B) mRNA levels by qRT-PCR of ESR1 (encoding ERα) (A) and ESR2 (encoding ERβ) (B) in immortalized cell lines. ESR1 levels in MCF7 (A) and ESR2 levels in A2780 (B) were set to 1 and the levels in myoblast cell lines relatively calculated. (C) Relative luciferase activity in CTL#1 myoblasts transfected with estrogen-responsive element-luciferase vector (ERE-Luc) and/or ERβFLAG as indicated, treated with or without E2 ± tamoxifen. Luminescence signal was normalized to total protein content. Mean ± SD of 2 independent experiments performed in triplicate is shown (n = 6). (D) Western blot analysis of endogenous ER and exogenous ERβFLAG (whose position relative to ER is indicated by the arrows) in CTL#1 myoblasts treated as indicated. See complete unedited blots in the supplemental material. (E) Representative photographs of MHC immunostaining (red) of myoblasts from FSHD#1 patient after 7 days of culture in differentiation medium in the absence or presence of indicated treatments. Scale bar: 75 μm. (F and G) Percentages of MHC+ (F) or fusion index (G) of cells treated as in E. Mean ± SD of 3 independent experiments. Four different fields for each condition were counted (n = 12). ***P < 0.001, 2-tailed Student’s t test.