Sildenafil reduces respiratory muscle weakness and fibrosis in the mdx mouse model of Duchenne muscular dystrophy.

Autor: Percival JM; Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA. justin.m.percival@gmail.com, Whitehead NP, Adams ME, Adamo CM, Beavo JA, Froehner SC
Jazyk: angličtina
Zdroj: The Journal of pathology [J Pathol] 2012 Sep; Vol. 228 (1), pp. 77-87. Date of Electronic Publication: 2012 Jul 18.
DOI: 10.1002/path.4054
Abstrakt: Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy caused by mutations in the dystrophin gene. Loss of dystrophin initiates a progressive decline in skeletal muscle integrity and contractile capacity which weakens respiratory muscles including the diaphragm, culminating in respiratory failure, the leading cause of morbidity and mortality in DMD patients. At present, corticosteroid treatment is the primary pharmacological intervention in DMD, but has limited efficacy and adverse side effects. Thus, there is an urgent need for new safe, cost-effective, and rapidly implementable treatments that slow disease progression. One promising new approach is the amplification of nitric oxide-cyclic guanosine monophosphate (NO-cGMP) signalling pathways with phosphodiesterase 5 (PDE5) inhibitors. PDE5 inhibitors serve to amplify NO signalling that is attenuated in many neuromuscular diseases including DMD. We report here that a 14-week treatment of the mdx mouse model of DMD with the PDE5 inhibitor sildenafil (Viagra(®), Revatio(®)) significantly reduced mdx diaphragm muscle weakness without impacting fatigue resistance. In addition to enhancing respiratory muscle contractility, sildenafil also promoted normal extracellular matrix organization. PDE5 inhibition slowed the establishment of mdx diaphragm fibrosis and reduced matrix metalloproteinase-13 (MMP-13) expression. Sildenafil also normalized the expression of the pro-fibrotic (and pro-inflammatory) cytokine tumour necrosis factor α (TNFα). Sildenafil-treated mdx diaphragms accumulated significantly less Evans Blue tracer dye than untreated controls, which is also indicative of improved diaphragm muscle health. We conclude that sildenafil-mediated PDE5 inhibition significantly reduces diaphragm respiratory muscle dysfunction and pathology in the mdx mouse model of Duchenne muscular dystrophy. This study provides new insights into the therapeutic utility of targeting defects in NO-cGMP signalling with PDE5 inhibitors in dystrophin-deficient muscle.
(Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)
Databáze: MEDLINE
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