Estrogenic regulation of skeletal muscle proteome: a study of premenopausal women and postmenopausal MZ cotwins discordant for hormonal therapy.

Eija K Laakkonen,Vuokko Kovanen,Urho M Kujala,Marc Baumann,Sarianna Sipilä,Rabah Soliymani,Sira Karvinen,Maciej Lalowski,Jaakko Kaprio

doi:10.1111/acel.12661

Eija K Laakkonen, Vuokko Kovanen + Show 7 more

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https://doi.org/10.1111/acel.12661

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Abstract

SummaryFemale middle age is characterized by a decline in skeletal muscle mass and performance, predisposing women to sarcopenia, functional limitations, and metabolic dysfunction as they age. Menopausal loss of ovarian function leading to low circulating level of 17β‐estradiol has been suggested as a contributing factor to aging‐related muscle deterioration. However, the underlying molecular mechanisms remain largely unknown and thus far androgens have been considered as a major anabolic hormone for skeletal muscle. We utilized muscle samples from 24 pre‐ and postmenopausal women to establish proteome‐wide profiles, associated with the difference in age (30–34 years old vs. 54–62 years old), menopausal status (premenopausal vs. postmenopausal), and use of hormone replacement therapy (HRT; user vs. nonuser). None of the premenopausal women used hormonal medication while the postmenopausal women were monozygotic (MZ) cotwin pairs of whom the other sister was current HRT user or the other had never used HRT. Label‐free proteomic analyses resulted in the quantification of 797 muscle proteins of which 145 proteins were for the first time associated with female aging using proteomics. Furthermore, we identified 17β‐estradiol as a potential upstream regulator of the observed differences in muscle energy pathways. These findings pinpoint the underlying molecular mechanisms of the metabolic dysfunction accruing upon menopause, thus having implications for understanding the complex functional interactions between female reproductive hormones and health.

Highlights

Skeletal muscle aging is characterized by progressive decline in muscle mass and function predisposing to sarcopenia, functional limitation, and metabolic dysfunction (Cruz-Jentoft et al, 2010)
Sex differences in skeletal muscle metabolism and the role of ovarian hormones and benefits of postmenopausal hormone replacement therapy (HRT) in combating aging-related decrements of muscle properties have gained a significant interest in last decades (e.g., Greising et al, 2009; Velders & Diel, 2013; Sipilaet al., 2015; Gheller et al, 2016), current knowledge base is overwhelmingly contributed by male studies with fewer input coming from studies concentrating on female-specific aspects of aging
Using nano-LC-HD-MSE, we identified in total 1583 proteins of which 797 were quantified (Table S1, Supporting information) and subjected to further analysis by applying the following scheme: (i) Postmenopausal nonhormone users were compared to premenopausal women (PRE; n = 6), in order to identify hormonal aging-associated differences at low E2 background; (ii) postmenopausal E2-HRT users (n = 6) were compared to PRE (n = 6), in order to identify hormonal aging-associated differences at E2-supplemented background; and (iii) to identify HRT-use-associated differences at genetically controlled, same age background, two separate comparisons were made: (iii-a) Postmenopausal E2-HRT women (n = 6) were compared to their nonusing cotwins (n = 6); and (iii-b) postmenopausal Tib-HRT users (n = 3) were compared to their nonusing cotwins (n = 3). Using this strategy and applying stringent filtering (│fold change (FC) > 1.5│, P < 0.05, ≥ 2 unique peptides observed by nano-LC-HD-MSE) to identify differentially expressed proteins (DEPs, Table S2, Supporting information), we identified hormonal aging-associated differences in the Premenop

Summary

Female middle age is characterized by a decline in skeletal muscle mass and performance, predisposing women to sarcopenia, functional limitations, and metabolic dysfunction as they age. We utilized muscle samples from 24 pre- and postmenopausal women to establish proteome-wide profiles, associated with the difference in age (30–34 years old vs 54– 62 years old), menopausal status (premenopausal vs postmenopausal), and use of hormone replacement therapy (HRT; user vs nonuser). We identified 17b-estradiol as a potential upstream regulator of the observed differences in muscle energy pathways. These findings pinpoint the underlying molecular mechanisms of the metabolic dysfunction accruing upon menopause, having implications for understanding the complex functional interactions between female reproductive hormones and health.

Introduction

Results and discussion

Testosterone

Concluding remarks

Experimental procedures