title: Hormone therapy and maximal eccentric exercise alters myostatin-related gene expression in postmenopausal women.
abstract: We sought to evaluate baseline mRNA values and changes in gene expression of myostatin-related factors in postmenopausal women taking hormone therapy (HT) and not taking HT after eccentric exercise. Fourteen postmenopausal women participated including 6 controls not using HT (59 ± 4 years, 63 ± 17 kg) and 8 women using HT (59 ± 4 years, 89 ± 24 kg). The participants performed 10 sets of 10 maximal eccentric repetitions of single-leg extension on a dynamometer. Muscle biopsies from the vastus lateralis were obtained from the exercised leg at baseline and 4 hours after the exercise bout. Gene expression was determined using reverse transcriptase polymerase chain reaction for myostatin, activin receptor IIb (ActRIIb), follistatin, follistatin-related gene (FLRG), follistatin-like-3 (FSTL3), and GDF serum-associated protein-1 (GASP-1). In response to the exercise bout, myostatin and ActRIIb significantly decreased (p < 0.05), and follistatin, FLRG, FSTL3, and GASP-1 significantly increased in both groups (p < 0.05). Significantly greater changes in gene expression of all genes occurred in the HT group than in the control group after the acute eccentric exercise bout (p < 0.05). These data suggest that postmenopausal women using HT express greater myostatin-related gene expression, which may reflect a mechanism by which estrogen influences the preservation of muscle mass. Further, postmenopausal women using HT experienced a profoundly greater myostatin-related response to maximal eccentric exercise.
authors.affiliation: Division of Biokinesiology and Physical Therapy, Clinical Exercise Research Center, University of Southern California, Los Angeles, California, USA. cdieli@usc.edu
authors.forename: Christina M
authors.initials: CM
authors.lastname: Dieli-Conwright
authors.forename: Tanya M
authors.initials: TM
authors.lastname: Spektor
authors.forename: Judd C
authors.initials: JC
authors.lastname: Rice
authors.forename: Fred R
authors.initials: FR
authors.lastname: Sattler
authors.forename: E Todd
authors.initials: ET
authors.lastname: Schroeder
mesh_terms: D030301:Activin Receptors, Type II / Q000235:genetics; D001823:Body Composition; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000627:therapeutic use; D015444:Exercise / Q000502:physiology*; D005260:Female; D038681:Follistatin / Q000235:genetics; D038702:Follistatin-Related Proteins / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D008875:Middle Aged; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000378:metabolism*; D055435:Myostatin / Q000235:genetics*; D017698:Postmenopause / Q000235:genetics* / Q000502:physiology; D011374:Progesterone / Q000627:therapeutic use; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*
chemical_list: D004967:Estrogens; D038681:Follistatin; D038702:Follistatin-Related Proteins; D036341:Intercellular Signaling Peptides and Proteins; D055435:Myostatin; D011506:Proteins; D012333:RNA, Messenger; C424444:WFIKKN2 protein, human; D011374:Progesterone; D030301:Activin Receptors, Type II; C425584:activin receptor type II-B