TITLE:
Glucocorticoid-induced alterations in titin, nebulin, myosin heavy chain isoform content and viscoelastic properties of rat skeletal muscle
AUTHORS:
Maire Aru, Karin Alev, Helena Gapeyeva, Arved Vain, Raivo Puhke, Ando Pehme, Priit Kaasik, Anne Selart, Teet Seene
KEYWORDS:
Viscoelastic Properties; Skeletal Muscle Atrophy; Myotonometry; Cytoskeletal Proteins; Glucocorticoids
JOURNAL NAME:
Advances in Biological Chemistry,
Vol.3 No.1,
February
26,
2013
ABSTRACT: Viscoelastic properties of
skeletal muscle are associated with a complex network of cytoskeletal proteins
where titin and nebulin play a substantial role. The need for evaluation of
muscle viscoelastic properties is widely accepted in clinical use to evaluate
the effect of treatment or progression of muscle pathology (atrophy). We
tested the hypothesis that the viscoelastic properties (elasticity, tone and
stiffness) change in atrophied muscles with concomitant changes in cytoskeletal
proteins (titin, nebulin) and contractile protein (myosin heavy chain)
proportion. Sixteen 24- week-old male rats
of the Wistar strain were randomly allocated to two groups: dexamethasone
group treated each day for 10 consecutive days with dexamethasone in order to
induce atrophy and control group. Skeletal muscle viscoelastic properties
(elasticity, tone and stiffness) were determined using a myotonometer. Titin,
nebulin and myosin heavy chain content were quantified using SDS-PAGE electrophoresis.
We found that glucocorticoid-induced muscle atrophy is accompanied by reduced
elasticity and increased tone and stiffness, with concomitant changes in titin,
nebulin and myosin heavy chain con- tent. The elasticity decreased by
10.9% (P P P dance for
rehabilitation practices and help to find rational therapeutic intervention in
the future.