Basic and Clinical Myology Laboratory

***NEW***

Click HERE for details on the rapidly approaching Australian Physiological Society (AuPS) meeting to be held at the University of Melbourne.

Click HERE to see photos of lab members at work and at play

Download the full text of our recent article "Role of b-adrenoceptor signaling in skeletal muscle: Implications for muscle wasting and disease" published in Physiological Reviews HERE

Muscle wasting and weakness are common in many disease states and conditions including ageing, cancer cachexia, denervation, disuse, unloading/microgravity, and the muscular dystrophies. Although the maintenance of muscle mass is generally regarded as a simple balance between protein synthesis and protein degradation, these mechanisms are not strictly independent but in fact are coordinated by a number of different and sometimes complementary signalling pathways. Our laboratory is interested in examining these different molecular pathways and their role in the etiology of muscle wasting disorders.

Research from this laboratory has led to the discovery that…

• Sarcopenia can be ameliorated in rats by treatment with b₂-adrenoceptor agonists
• Treatment with the cytokine Interleukin-15 or the growth factor insulin-like growth factor-I, improves the function of muscles from dystrophic mice
• Inhibition of the calcineurin signalling cascade impairs muscle structure and function in young dystrophic mice
• b₂-adrenoceptors are involved in the repair process of muscles after injury and adrenoceptor stimulation via an agonist can speed up recovery from injury

In addition, work from this laboratory has resulted in a fully optimised electroporation protocol for studying gene expression in skeletal muscle.

	Basic and Clinical Myology Laboratory (2008) - [Back, from left] Dr. Jarrod Church (Senior Research Officer), Dr. Chris van der Poel (Research Officer), Mr. Stefan Gehrig (PhD student), Mr. Ben Gleeson (research assistant), Dr. René Koopman (Research Fellow), Mr. Tim Naim (research assistant), Mr. Nic Tirtaatmadja (PhD student), Prof. Gordon Lynch (laboratory head) [Front, from left], Miss. Hui Qing Lim (honours student), Miss. Radhika Sheorey (honours student), Miss. Sarah Snell (honours student), Ms. Fiona Colarossi (laboratory manager), Dr. Kate Murphy (Research Fellow), Miss. Jo Stratton (honours student), Mr. Daniel Ham (PhD student). Absent - Ms. Leah Harcourt (PhD student), Miss. Sarah Turpin (PhD student), Brendan Adams (research assistant), Jennifer Triue (research assistant).

A single muscle fibre isolated from a small bundle of rat EDL muscle fibres. The bundle remains intact with the whole EDL muscle.		A single muscle fibre mechanically skinned under paraffin oil (fibre diameter ~ 50 µm). The sarcolemma is 'peeled' back with fine forceps, forming a 'cuff' as it is removed from the fibre.

• Dr. Paul Gregorevic (Baker IDI Heart and Diabetes Institute). Gene therapy and skeletal muscle.
• Dr. Craig Harrison (Prince Henry’s Institute of Medical Research, Victoria, Australia). TGF-beta signalling in muscular dystrophy.
• Dr. Aaron Russell (School of Exercise and Nutrition Sciences, Deakin University, Victoria, Australia). Role of Notch signalling in muscle health and disease.
• Prof. João Bizario (Associação de Amigos dos Portadores de Distrofia Muscular, São Paulo, Brazil). Characterisation of the Golden Retriver model of muscular dystrophy.
• Prof. Miranda Grounds (University of Western Australia). Functional regeneration in skeletal muscles during ageing and in muscular dystrophy.
• Prof. Mark Hargreaves (Department of Physiology, The University of Melbourne). Functional and metabolic characteristics of artificial skeletal muscles.
• Dr. Glenn McConnell (Department of Physiology, The University of Melbourne). nNOS signalling in skeletal muscle regeneration.
• Assoc. Prof. Edna Hardeman & Dr. Anthony Kee (Department of Anatomy, School of Medical Sciences, University of New South Wales, Sydney). Role of cytoskeletal proteins in skeletal muscle contraction.
• Prof. David A. Williams (Department of Physiology, The University of Melbourne). In situ and in vitro skeletal muscle calcium imaging.
• Prof. Bruce E. Kemp, Dr. Belinda Michell & Dr. Greg Steinberg (St. Vincent’s Hospital Research Institute, The University of Melbourne). AMP-kinase during intense muscle activity; calcineurin activity in skeletal muscle; aging and skeletal muscle metabolism.
• Prof. Wayne A. Morrison (Bernard O’Brien Institute for Microsurgery, The University of Melbourne). Improving skeletal muscle repair after ischaemia-reperfusion injury.
• Prof. George E. Muscat (Institute for Molecular Bioscience, The University of Queensland). Nuclear hormone receptors and skeletal muscle.
• Prof. Eric Olson & Assoc. Prof. Rhonda Bassel-Duby (University of Texas-Southwestern, U.S.A.). Role of the calcineurin signal transduction pathway in muscle regeneration and muscular dystrophy.
• Prof. Martin N. Sillence (Queensland University of Technology, Qld.). b₂-adrenoceptors, b₂-agonists and skeletal muscle function.
• Prof. Geoff W. Stevens & Dr. Andrea O'Connor (Department of Chemical & Biomolecular Engineering, The University of Melbourne). Interactions between the interfaces of solid-liquid and liquid-liquid systems for the dispersion of novel growth factors.
• Assoc. Prof. Matthew J. Watt (Department of Physiology, Monash University). Molecular and cell biology of lipid metabolism.
• Prof. Michael G. Woods (School of Dentistry, The University of Melbourne). Functional properties of human facial muscles and their relation to clinical dentistry.
• Prof. Jeffrey Zajac & Dr. Helen Maclean (Department of Medicine Austin and Repatriation Hospital). Androgens and skeletal muscle function.
• Assoc. Prof. Luc Gosselin (Exercise and Nutrition Sciences, University at Buffalo, The State University of New York). Ageing, inflammation and muscle repair.
• Prof. Mark Febbraio (Baker IDI Heart and Diabetes Institute). Role of heat shock proteins in muscle damage and repair in muscular dystrophy.

Tibialis anterior muscles of control and IGF-I treated mice stained for laminin and visualised using fluorescence microscopy. Note the increase in fibre size associated with IGF-I treatment in the right panel.

Day 1	Day 2	Day 3	Day 4	Day 5
H & E stained sections from the TA muscles of mice following injury with myotoxic agent Notexin. Note the slow degeneration of muscle fibres during the first 3 days of regeneration, followed by the appearance of centrally nucleated fibres at day 4 and 5.

Click on author to link to abstract (** access to full text available)

Schertzer JD. & Lynch GS. (2008). Plasmid-based gene transfer in mouse skeletal muscle by electroporation. Methods Mol Biol. 433: 115-25.

Gehrig SM, Ryall JG, Schertzer JD, Lynch GS. (2008). IGF-I analogue protects muscles of dystrophic mdx mice from contraction-mediated damage. Exp. Physiol. (in press).

Lynch GS, Faulkner JA, Brooks SV. (2008). Force deficits and breakage rates after single lengthening contractions of single fast fibers from unconditioned and conditioned muscles of young and old rats. Am. J. Physiol. Cell Physiol. 295: C249-C256.

Grounds MD, Radley HG, Lynch GS, Nagaraju K, De Luca A. (2008). Towards developing standard operating procedures for pre-clinical testing in the mdx mouse model of Duchenne muscular dystrophy. Neurobiol Dis. 31: 1-19.

Lynch GS, Schertzer JD, Ryall JG. (2008). Anabolic agents for improving muscle regeneration and function after injury. Clin. Exper. Pharmacol. Physiol. 35: 852-858.

Ryall JG, Schertzer JD, Murphy KT, Allen AM & Lynch GS (2008). Chronic b₂-adrenoceptor stimulation impairs cardiac relaxation via reduced SR Ca²⁺-ATPase activity. Am. J. Physiol. Heart Circ. Physiol.294: H2587-H2595.

Ryall JG, Schertzer JD, Alabakis TM, Gehrig SM, Plant DR & Lynch GS (2008). Intramuscular b₂-agonist administration enhances regeneration and functional repair after myotoxic injury in rat skeletal muscle. J. Appl. Physiol.105: 165-172.

**Ryall JG, Schertzer JD & Lynch GS (2008). Cellular and molecular mechanisms underlying age-related skeletal muscle wasting and weakness. Biogerontol.9: 213-228.

Stupka N, Schertzer JD, Bassel-Duby R, Olson EN & Lynch GS (2008). Stimulation of calcineurin-Aa activity attenuates muscle pathophysiology in mdx dystrophic mice. Am. J. Physiol. Reg. Int. Comp. Physiol. 294: R983-R992.

Schertzer JD*, van der Poel C*, Shavlakadze T, Grounds MD & Lynch GS (2008). Muscle specific overexpression of IGF-I improves E-C coupling in skeletal muscle fibers from dystrophic mdx mice. Am. J. Physiol. Cell. Physiol. 294:C161-168. [*- these authors contributed equally to this manuscript]

**Lynch GS & Ryall JG (2008). Role of b-adrenoceptor signaling in skeletal muscle: Implications for muscle wasting and disease. Physiol. Rev. 88:729-767.

Book Chapters

Schertzer JD, & Lynch GS (2008). Methods for optimising non-viral ectopic gene expression in normal and regenerating muscle. In (ed) Le Doux JM Gene Therapy Protocols Humana Press, 115-125.

2007

Beitzel F, Sillence MN & Lynch GS (2007). b-adrenoceptor signaling in regenerating skeletal muscle after b-agonist administraion. Am. J. Physiol. Endocrinol. Metab. 293: E932-E940.

Schertzer JD*, Gehrig SM*, Ryall JG & Lynch GS (2007). Modulation of IGF-I and IGFBP interactions enhances skeletal muscle regeneration and ameliorates the dystrophic pathology in mdx mice. Am. J. Pathol. 171: 1180-1188. [*- these authors contributed equally to this manuscript]

Ryall JG, Schertzer JD & Lynch GS (2007). Attenuation of age-related muscle wasting and weakness in rats after formoterol treatment: therapeutic implications for sarcopenia. J. Gerontol. Series A. 62: 813-823.

Stupka N, Schertzer JD, Bassel-Duby R, Olson EN & Lynch GS (2007). Calcineurin-Aa activation enhances the structure and function of regenerating muscles after myotoxic injury. Am. J. Physiol. Reg. Int. Comp. Physiol. 293: R686-R694.

Lynch GS, Schertzer JD & Ryall JG (2007). Therapeutic approaches for muscle wasting disorders. Pharmacol. Ther. 113: 461-487.

**Harcourt LJ, Schertzer JD, Ryall JG & Lynch GS (2007). Low dose formoterol administration improves muscle function in dystrophic mdx mice without increasing fatigue. Neuromusc. Disord. 17: 47-55.

Intact skeletal muscles – We examine the contractile properties of different muscles of rats or mice using in situ (with an intact nerve and blood supply) or in vitro methods. The muscles most commonly assessed are the extensor digitorum longus (EDL) representative of a fast-twitch muscle and the soleus muscle which is representative of a slow-twitch muscle. We typically assess the tibialis anterior muscle using an in situ approach and study the contractile properties of isolated diaphragm muscle strips in vitro.

Single muscle fibres (cells) – Segments of single muscle cells (i.e. muscle fibres) can be carefully dissected from intact muscles (of rats and mice) or from open- or needle-biopsies from animals or humans. We attach these isolated muscle fibre segments to sensitive force transducers and servomotors to assess the contractile properties of skeletal muscle at the cellular level.

H & E stained sections from the tibialis anterior (TA) muscles of control, and mdx mice. Note the irregular sized fibres in the TA muscle of the mdx mouse and the centrally located nuclei, which is indicative of regenerating skeletal muscle fibres.

24 hours	48 hours		72 hours	96 hours
Myoblasts differentiating into myotubes in culture. To form new muscle, myoblasts (muscle precursor cells) proliferate and then fuse together to form multinucleated muscle fibres. We can examine the ability of various therapeutic compounds to enhance either myoblast proliferation or myoblast fusion.

The laboratory utilises a number of animal models to study muscular dystrophy and ageing, including;

• mdx - the mdx mouse arose from a spontaneous mutation in the gene encoding the dystrophin gene (located on the X chromosome) in the C57Bl10 mouse. The mdx mouse is the most commonly studied model of Duchene muscular dystrophy (DMD).
• Adrb null - we have recently acquired mice that are gentically null for the β₁-adrenoceptor (Adrb1-/-), the β₂-adrenoceptor (Adrb2-/-), or both (Adrb1/2-/-)
• dko - the utrophin null dystrophic mdx mouse (mdx/utrn^-/-) known as the double knock out (dko) mouse. dko mice lack both dystrophin and utrophin (structural/signalling proteins linked to the muscle membrane) which causes muscular dystrophy similar to humans suffering DMD.
• F344 - the Fischer 344 (F344) rat is traditionally used in studies investigating the effect of ageing on skeletal muscle. The F344 rat is generally considered ‘old’ after the age of 24 months, and shows severe age related muscle wasting and weakness (termed ‘sarcopenia’) after the age of 28 months.

Contractile traces from extensor digitorum longus (EDL) muscles from young (12 week old) and old (28 month old) F344 rats. Note the reduced maximum force in the old muscle, and the prolongation of relaxation.

Postdoctoral Researchers:

• Dr. Paul Gregorevic (Pfizer Australia Senior Research Fellow, Laboratory for Muscle Research and Therapeutics Development, The Baker Heart Research Institute, Melbourne, VIC, Australia)
• Dr. David R. Plant (Senior Regulatory Affairs Associate, CSL Limited, Melbourne, VIC, Australia)
• Dr. Jonathan D. Schertzer (NSERC Research Fellow, The Hospital for Sick Children, Ontario, Canada)
• Dr. James G. Ryall (CJ Martin Fellow, The Laboratory of Muscle Stem Cells and Gene Regulation, NIH, MD, USA)

Ph.D. students:

• Dr. Noel D. Duncan (Executive Director, Health1st Pty. Ltd. T/A Fitness2live, London, UK)
• Dr. Siun P. O'Sullivan (Lecturer, Biomedical Sciences, Victoria University of Technology, Melbourne, VIC, Australia)
• Dr. Paul Gregorevic (Pfizer Australia Senior Research Fellow, Laboratory for Muscle Research and Therapeutics Development, The Baker Heart Research Institute, Melbourne, VIC, Australia)
• Dr. David R. Plant (Senior Regulatory Affairs Associate, CSL Limited, Melbourne, VIC, Australia)
• Dr. James G. Ryall (CJ Martin Fellow, The Laboratory of Muscle Stem Cells and Gene Regulation, NIH, MD, USA)
• Dr. Nicole Stupka (Peter Doherty Fellow, Deakin University, Melbourne, VIC, Australia)
• Dr. Jonathan D. Schertzer (Postdoctoral Researcher, The Hospital for Sick Children, Ontario, Canada)
• Dr. Felice Beitzel (training for the Winter Olympics in Bend, Oregon)

B.Sc. (Honours) students:

Visitors/Sabbaticals

November-April 2000: Prof. Bartley R. Frueh, Kellogg Eye Center, Department of Ophthalmology, The University of Michigan.

November-April 2006: A/Prof. Luc Gosselin, Department of Exercise and Nutrition Sciences, University at Buffalo The State University of New York.

For more information about potential opportunities to work/study in the Basic and Clinical Myology Laboratory, please contact: