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Simon Lees, Ph.D.

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Research Interests

The study of skeletal muscle precursor cells (MPCs, also known as satellite cells), which are a population of adult stem cells required for muscle growth and repair/regeneration. Current projects include:

• Delineating mechanisms, as well as, potential treatments aimed at attenuating MPC-induced skeletal muscle fibrosis. Aging is associated with decreased skeletal muscle mass and a diminished capacity for skeletal muscle regeneration. In place of skeletal muscle, increased fibrotic tissue is observed, which contributes to the overall decrease in skeletal muscle quality. Recent evidence suggests that MPCs may transition from a myogenic to fibrogenic cell lineage.
• Delineating mechanisms of age-associated differences in MPC cytokine sensitivity. The local inflammatory status of aged skeletal muscle has been implicated as a key regulator of sarcopenia and an impaired skeletal muscle regenerative capacity. Currently, I am studying the interaction of various cytokines with MPCs isolated from young and old skeletal muscle.

Education

• Postdoctoral Training, Biomedical Sciences, University of Missouri, Columbia, MO (2003-2008)
• Ph.D., Skeletal Muscle Physiology and Biochemistry, Human, Nutrition, Foods and Exercise, Virginia Tech, VA (2000-2003)
• M.S., Skeletal Muscle Physiology and Biochemistry, Human, Nutrition, Foods and Exercise, Virginia Tech, VA (1998-2000)
• B.H.K., Exercise Science, University of British Columbia, B.C., Canada

Selected Recent Publications

• Steffen, B.T., Lees, S.J., & Booth, F.W. (2008). Anti-TNF Treatment Reduces Skeletal Muscle Wasting in Monocrotaline-Induced Cardiac Cachexia. Journal of Applied Physiology, 105(6), 1950-8.
• Lees, S.J., Childs, T.E., & Booth, F.W. (2008). Age-Dependent FOXO Regulation Of p27Kip1 Expression Via A Conserved Binding Motif In Rat Muscle Precursor Cells. American Journal of Physiology. Cell Physiology, 295(5), C1238-46.
• Rathbone, C.R., Booth, F.W., & Lees, S.J. (2008). Sirt1 increases muscle precursor cell cycle progression. European Journal of Cell Biology, 88(1), 35-44.
• Morris, R.T., Fine, D.M., Lees, S.J., Booth, F.W., Ferrario, C.M., Sowers, J.R., & Stump, C.S. (2008). Exercise training maintains cardiac output and stroke volume in hypertensive TG (mRen-2)27 rats with impaired diastolic function. Journal of the American Society of Hypertension, 1(6), 393-9.
• Lees, S.J., Rathbone, C.R., & Booth,F.W. (2008). p21Cip1 Expression is Increased in Ambient Oxygen, Compared to Estimated Physiological (5%) Levels in Rat Muscle Precursor Cell Culture. Cell Proliferation, 41(2), 193-207.
• Morris, R.T., Laye, M.J., Lees, S.J., Rector, R.S., Thyfault, J.P., & Booth, F.W. (2008). Exercise-induced attenuation of obesity, hyperinsulinemia, and lipid peroxidation in the OLETF rat. Journal of Applied Physiology, 104(3), 708-15.
• Rathbone, C.R., Booth, F.W., & Lees, S.J. (2008). FoxO3a induced p27Kip1 expression impairs muscle precursor cell cycle progression. Muscle and Nerve, 37(1), 84-89.
• Booth, F.W., Laye, M.J., Lees, S.J., Rector, R.S., & Thyfault, J.P. (2008). Reduced physical activity and risk of chronic disease: the biology behind the consequences. European Journal of Applied Physiology 102(4), 381-390.
• Booth, F.W. & Lees, S.J. (2007). Fundamental questions about genes, inactivity, and chronic diseases. Physiological Genomics, 28(2), 146-157.
• Batts, T.W., Spangenburg, E.E., Ward, C.W., Lees, S.J., & Williams, J.H. (2007). Effects of acute epinephrine treatment on skeletal muscle Sarcoplasmic Reticulum Ca2+ ATPase. Basic and Applied Myology, 17, 229-235.
• Otis, J.S., Lees, S.J., & Williams, J.H. (2007) Functional overload attenuates plantaris atrophy in tumor-bearing rats. BMC Cancer, 7, 146.
• Lees, S.J., Rathbone, C.R., & Booth, F.W. (2006). Age-Associated Decrease in Muscle Precursor Cell Differentiation. American Journal of Cell Physiology. Cell Physiology, 290, C609-C615.
• Lees, S.J., & Booth, F.W. (2005). Physical inactivity is a disease. World Reviews of Nutrition and Dietetics, 95, 73-79.
• Lees, S.J., & Booth, F.W. (2004). Sedentary Death Syndrome. Canadian Journal of Applied Physiology, 29(4), 447-460.
• Talmadge, R.J., Otis, J.S., Rittler, M.R., Garcia, N.D., Spencer, S.R., Lees, S.J., Naya, F.J. (2004). Calcineurin activation influences muscle phenotype in a muscle-specific fashion. BMC Cell Biology, 28;5(1), 28.
• Lees, S.J., Chen, Y.T., & Williams, J.H. (2004). Glycogen debranching enzyme is associated with rat skeletal muscle sarcoplasmic reticulum. Acta Physiologica Scandinavica, 181, 239-245.
• Lees, S.J., & Williams, J.H. (2004). Skeletal muscle sarcoplasmic reticulum glycogen status influences Ca2+ uptake supported by endogenously synthesized ATP. American Journal of Cell Physiology. Cell Physiology, 286, C97-104.
• Spangenburg, E.E., Lees, S.J., Otis, J.S., Talmadge, R.J., Musch, T.I., & Williams, J.H. (2002). Effects of moderate heart failure and functional overload on rat plantaris muscle. Journal of Applied Physiology, 92, 18-24.
• Lees, S.J., Franks, P.D., Spangenburg, E.E., & Williams, J.H. (2001). Glycogen and glycogen phosphorylase associated with sarcoplasmic reticulum: effects of fatiguing activity. Journal of Applied Physiology, 91, 1638-44.

Honors and Awards

• Research Recognition Award, National Space Biomedical Research Institute. Year: 2008
• Co-Investigator, NIH National Institute on Aging (RO1 AG18780). Title: Satellite Stem Cell Biology. PI: Frank Booth, Ph.D. Year: 2007-2008
• Young Investigator Award for research presented at the Skeletal Muscle Satellite and Stem Cells conference, Federation of American Societies for Experimental Biology (FASEB). Year: 2005
• Post Graduate Scholarship, Natural Sciences and Engineering Research Council of Canada. Year: 2001-2003
• Outstanding Student Presentation, American Physiological Society, presented at Experimental Biology. Year: 2000