Skeletal muscle gene expression profiles in 20–29 year old and 65–71 year old women

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Abstract

Gene expression profiling may provide leads for investigations of the molecular basis of functional declines associated with aging. In this study, high-density oligonucleotide arrays were used to probe the patterns of gene expression in skeletal muscle of seven young women (20–29 years old) and eight healthy older women (65–71 years old). The older subjects had reduced muscle mass, strength, and peak oxygen consumption relative to young women. There were ∼1000 probe sets that suggested differential gene expression in younger and older muscle according to statistical criteria. The most highly overexpressed genes (>3-fold) in older muscle were p21 (cyclin-dependent kinase inhibitor 1A), which might reflect increased DNA damage, perinatal myosin heavy chain, which might reflect increased muscle fiber regeneration, and tomoregulin, which does not have a defined function in muscle. More than 40 genes encoding proteins that bind to pre-mRNAs or mRNAs were expressed at higher levels in older muscle. More than 100 genes involved in energy metabolism were expressed at lower levels in older muscle. In general, these results support previous observations on the differences in gene expression profiles between younger and older men.

Introduction

Sarcopenia, the decline in muscle mass and function associated with aging, limits independence, reduces the quality of life, and increases the probability of falling. Because women have less muscle mass and strength than men, this problem is especially significant in older women. A gradual loss of motor neurons is thought to be an important determinant of muscle fiber loss in old age, even though sprouting of motor nerve axons can re-innervate and rescue many of the denervated fibers (Lexell, 1997, Luff, 1998). Age-related changes in hormone and cytokine levels probably have some role in sarcopenia (Lamberts et al., 1997, Roubenoff, 2003). Oxidative damage to proteins and DNA also might be responsible for cell loss or dysfunction (Mecocci et al., 1999). A reduction in physical activity with aging may contribute to muscle fiber atrophy and altered metabolic activity of muscle in some persons, although muscle mass and function decline with aging even in the most active individuals (references cited in Welle, 2002).

The ultimate effects of denervation, reactive oxygen species, hormonal changes, and behavioral changes on muscle mass and function depend to a large extent on the expression of genes required for tissue homeostasis or adaptation to patterns of contractile activity. Gene expression profiling technology permits the parallel assessment of expression levels of thousands of genes, and may lead to a better understanding of the molecular basis of sarcopenia and other age-related problems. Most previous studies of the effect of aging on muscle gene expression profiles did not include women (Jozsi et al., 2000, Welle et al., 2000, Welle et al., 2002b). Roth et al. (2002) included both men and women in their filter array study of aging in human skeletal muscle (∼1000 genes). However, because individual RNA samples were pooled, they could not determine the statistical significance of the apparent age-related differences in women. Because women and men differ in hormone levels and certain characteristics of muscle (Coggan et al., 1992, Frontera et al., 2000, Hunter and Enoka, 2001, Simoneau and Bouchard, 1989, Staron et al., 2000), it cannot be assumed that they have identical age-related changes in muscle. Thus, the present study was done to determine the effect of aging on muscle gene expression profiles in women.

Section snippets

Methods

The subjects were seven young (20–29 years old) and eight older (65–71 years old) women. All were healthy according to blood tests, history, and physical examination. Subjects signed a consent form after risks were explained. The project was approved by the University of Rochester Research Subjects Review Board.

The subjects were not engaged in any type of regular exercise program involving strenuous activity for more than 2 h per week, nor did they perform any high-resistance exercises

Results

As expected, older women who had less lean tissue mass, were weaker, and had a lower peak rate of oxygen consumption (Table 1). However, isometric knee extension strength per kg leg lean tissue mass was similar in younger and older women. There was no significant effect of age (P>0.20) on patterns of expression of the major adult MyHC isoforms, types 1, 2a, and 2x (data not shown).

The gene expression profiles of each individual have been deposited in the National Center for Biotechnology

Discussion

The gene expression profiles of older women suggest that their muscles detect an increased amount of DNA damage relative to young muscles. One of the most highly overexpressed genes (↑ 4-fold) is p21, a cyclin-dependent kinase inhbitor that is overexpressed in response to DNA damage (Hattinger et al., 2002, Kaufmann and Paules, 1996). An age-related increase in p21 expression also was observed in muscle of men (↑ 2.9-fold) (Welle et al., 2003) and monkeys (↑ 4.1-fold) (Kayo et al., 2001). In

Acknowledgements

We thank Don Henderson and Catherine Muzytchuk for technical assistance. SAM software, version 1.12, was provided by Stanford University. The project was supported by grants from the NationaI Institutes of Health, AG-17891, AG-18254, RR-00044, and AR/NS-48143.

References (58)

  • Y.W. Chen et al.

    Expression profiling in the muscular dystrophies: identification of novel aspects of molecular pathophysiology

    J. Cell Biol.

    (2000)
  • A.R. Coggan et al.

    Histochemical and enzymatic comparison of the gastrocnemius muscle of young and elderly men and women

    J. Gerontol. A Biol. Sci. Med. Sci.

    (1992)
  • G. Dreyfuss et al.

    Messenger-RNA-binding proteins and the messages they carry

    Nat. Rev. Mol. Cell Biol.

    (2002)
  • S. Endesfelder et al.

    Elevated p21 mRNA level in skeletal muscle of DMD patients and mdx mice indicates either an exhausted satellite cell pool or a higher p21 expression in dystrophin-deficient cells per se

    J. Mol. Med.

    (2000)
  • N.A. Faustino et al.

    Pre-mRNA splicing and human disease

    Genes Dev.

    (2003)
  • W.R. Frontera et al.

    Skeletal muscle fiber quality in older men and women

    Am. J. Physiol. Cell Physiol.

    (2000)
  • M. Grompe et al.

    Fanconi anemia and DNA repair

    Hum. Mol. Genet.

    (2001)
  • K. Guo et al.

    MyoD-induced expression of p21 inhibits cyclin-dependent kinase activity upon myocyte terminal differentiation

    Mol. Cell Biol.

    (1995)
  • O. Halevy et al.

    Correlation of terminal cell cycle arrest of skeletal muscle with induction of p21 by MyoD

    Science

    (1995)
  • J.N. Haslett et al.

    Gene expression comparison of biopsies from Duchenne muscular dystrophy (DMD) and normal skeletal muscle

    Proc. Natl Acad. Sci. USA

    (2002)
  • C.M. Hattinger et al.

    Induction of p21 mRNA synthesis after short-wavelength UV light visualized in individual cells by RNA FISH

    J. Histochem. Cytochem.

    (2002)
  • J.J. Hill et al.

    Regulation of myostatin in vivo by growth and differentiation factor-associated serum protein-1: a novel protein with protease inhibitor and follistatin domains

    Mol. Endocrinol.

    (2003)
  • S.K. Hunter et al.

    Sex differences in the fatigability of arm muscles depends on absolute force during isometric contractions

    J. Appl. Physiol.

    (2001)
  • W. Jin et al.

    The contributions of sex, genotype and age to transcriptional variance in Drosophila melanogaster

    Nat. Genet.

    (2001)
  • W.K. Kaufmann et al.

    DNA damage and cell cycle checkpoints

    FASEB J.

    (1996)
  • T. Kayo et al.

    Influences of aging and caloric restriction on the transcriptional profile of skeletal muscle from rhesus monkeys

    Proc. Natl Acad. Sci. USA

    (2001)
  • J.M. Kearsey et al.

    Gadd45 is a nuclear cell cycle regulated protein which interacts with p21Cip1

    Oncogene

    (1995)
  • J. Kikuchi et al.

    Identification of novel p53-binding proteins by biomolecular interaction analysis combined with tandem mass spectrometry

    Mol. Biotechnol.

    (2003)
  • G.J. Kops et al.

    Forkhead transcription factor FOXO3a protects quiescent cells from oxidative stress

    Nature

    (2002)
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