stilbenes and Muscular-Dystrophy--Duchenne

The muscular dystrophies, which cause progressive weakening of the skeletal muscles, are frequently associated with cardiomyopathy. In fact, the leading cause of mortality in patients with Duchenne muscular dystrophy, the most common and most severe type of muscular dystrophy, is heart failure due to cardiomyopathy. Therefore, more effective methods for treating cardiomyopathy are expected to improve long-term outcomes for patients with Duchenne muscular dystrophy. Our recent preclinical data show that treatment with the SIRT1 activator resveratrol is beneficial for dystrophic cardiomyopathy. We examined the effects of resveratrol treatment in two different models of muscular dystrophy: dystrophin-deficient mdx mice and δ-sarcoglycan-deficient TO-2 hamsters. In both models, resveratrol suppressed cardiac hypertrophy, preserved cardiac function, and reduced tissue fibrosis in the diseased heart. Importantly, resveratrol significantly improved survival in TO-2 hamsters. Resveratrol also attenuated skeletal muscle pathology in mdx mice. These promising results indicate resveratrol's potential for clinical translation to treat cardiomyopathy in patients with muscular dystrophies.

Topics: Animals; Cardiomyopathies; Cardiotonic Agents; E1A-Associated p300 Protein; Enzyme Activation; Humans; Muscular Dystrophy, Duchenne; Proteolysis; Resveratrol; Sirtuin 1; Stilbenes; Ubiquitination

Antioxidants have a great potential as adjuvant therapeutics in patients with Duchenne muscular dystrophy, although systematic comparisons at pre-clinical level are limited. The present study is a head-to-head assessment, in the exercised mdx mouse model of DMD, of natural compounds, resveratrol and apocynin, and of the amino acid taurine, in comparison with the gold standard α-methyl prednisolone (PDN). The rationale was to target the overproduction of reactive oxygen species (ROS) via disease-related pathways that are worsened by mechanical-metabolic impairment such as inflammation and over-activity of NADPH oxidase (NOX) (taurine and apocynin, respectively) or the failing ROS detoxification mechanisms via sirtuin-1 (SIRT1)-peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) (resveratrol). Resveratrol (100mg/kg i.p. 5days/week), apocynin (38mg/kg/day per os), taurine (1g/kg/day per os), and PDN (1mg/kg i.p., 5days/week) were administered for 4-5 weeks to mdx mice in parallel with a standard protocol of treadmill exercise and the outcome was evaluated with a multidisciplinary approach in vivo and ex vivo on pathology-related end-points and biomarkers of oxidative stress. Resveratrol≥taurine>apocynin enhanced in vivo mouse force similarly to PDN. All the compounds reduced the production of superoxide anion, assessed by dihydroethidium staining, with apocynin being as effective as PDN, and ameliorated electrophysiological biomarkers of oxidative stress. Resveratrol also significantly reduced plasma levels of creatine kinase and lactate dehydrogenase. Force of isolated muscles was little ameliorated. However, the three compounds improved histopathology of gastrocnemius muscle more than PDN. Taurine>apocynin>PDN significantly decreased activated NF-kB positive myofibers. Thus, compounds targeting NOX-ROS or SIRT1/PGC-1α pathways differently modulate clinically relevant DMD-related endpoints according to their mechanism of action. With the caution needed in translational research, the results show that the parallel assessment can help the identification of best adjuvant therapies.

Topics: Acetophenones; Animals; Antioxidants; Disease Models, Animal; Male; Methylprednisolone; Mice; Mice, Inbred mdx; Muscle, Skeletal; Muscular Dystrophy, Duchenne; NADPH Oxidases; NF-kappa B; Oxidative Stress; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Physical Conditioning, Animal; Reactive Oxygen Species; Resveratrol; Sirtuin 1; Stilbenes; Taurine

Slower, more oxidative muscle fibers are more resistant to the dystrophic pathology in Duchenne muscular dystrophy (DMD) patients as well as in the preclinical mdx mouse model of DMD. Therefore, one therapeutic strategy for DMD focuses on promoting expression of the slow, oxidative myogenic program. In the current study, we explored the therapeutic potential of stimulating the slow, oxidative phenotype in mdx mice by feeding 6-wk-old animals with the natural phenol resveratrol (RSV; ~100 mg·kg(-1)·day(-1)) for 6 wk. Sirtuin 1 (SIRT1) activity and protein levels increased significantly, as well as peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) activity, in the absence of alterations in AMPK signaling. These adaptations occurred concomitant with evidence of a fast, glycolytic, to slower, more oxidative fiber type conversion, including mitochondrial biogenesis and increased expression of slower myosin heavy chain isoforms. These positive findings raised the question of whether increased exposure to RSV would result in greater therapeutic benefits. We discovered that an elevated RSV dose of ~500 mg·kg(-1)·day(-1) across a duration of 12 wk was clearly less effective at muscle remodeling in mdx mice. This treatment protocol failed to influence SIRT1 or AMPK signaling and did not result in a shift towards a slower, more oxidative phenotype. Taken together, this study demonstrates that RSV can stimulate SIRT1 and PGC-1α activation, which in turn may promote expression of the slow, oxidative myogenic program in mdx mouse muscle. The data also highlight the importance of selecting an appropriate dosage regimen of RSV to maximize its potential therapeutic effectiveness for future application in DMD patients.

Topics: AMP-Activated Protein Kinases; Animals; Antioxidants; Disease Models, Animal; Glycolysis; Male; Mice; Mice, Inbred mdx; Muscle Development; Muscle Fibers, Slow-Twitch; Muscular Dystrophy, Duchenne; Oxidation-Reduction; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Phenotype; Resveratrol; Signal Transduction; Sirtuin 1; Stilbenes; Transcription Factors

Duchenne muscular dystrophy (DMD) is a lethal genetic disease with no cure. Reducing inflammation or increasing utrophin expression can alleviate DMD pathology. Resveratrol can reduce inflammation and activate the utrophin promoter. The aims of this study were to identify an active dose of resveratrol in mdx mice and examine if this dose decreased inflammation and increased utrophin expression.. 5-week old mdx mice were given 0, 10, 100, or 500 mg/kg of resveratrol everyday for 10 days. Sirt1 was measured by qRT-PCR and used to determine the most active dose. Muscle inflammation was measured by H&E staining, CD45 and F4/80 immunohistochemistry. IL-6, TNFα, PGC-1α, and utrophin gene expression were measured by qRT-PCR. Utrophin, Sirt1, and PGC-1α protein were quantified by western blot.. The 100 mg/kg dose of resveratrol, the most active dose, increased Sirt1 mRNA 60 ± 10% (p < 0.01), reduced immune cell infiltration 21 ± 6% (H&E) and 42 ± 8% (CD45 immunohistochemistry (p < 0.05)), reduced macrophage infiltration 48 ± 10% (F4/80 immunohistochemistry (p < 0.05)), and increased IL-6, PGC-1α, and utrophin mRNA 247 ± 77%, 27 ± 17%, and 43 ± 23% respectively (p ≤ 0.05). Utrophin, Sirt1, and PGC-1α protein expression did not change.. Resveratrol may be a therapy for DMD by reducing inflammation.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Body Weight; Dietary Supplements; Disease Models, Animal; Inflammation Mediators; Leukocytes; Macrophages; Male; Mice; Mice, Inbred mdx; Muscle Development; Muscle, Skeletal; Muscular Dystrophy, Duchenne; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Resveratrol; RNA, Messenger; Sirtuin 1; Stilbenes; Trans-Activators; Transcription Factors; Up-Regulation; Utrophin

Muscular dystrophies are inherited myogenic disorders accompanied by progressive skeletal muscle weakness and degeneration. We previously showed that resveratrol (3,5,4'-trihydroxy-trans-stilbene), an antioxidant and activator of the NAD(+)-dependent protein deacetylase SIRT1, delays the progression of heart failure and prolongs the lifespan of δ-sarcoglycan-deficient hamsters. Because a defect of dystroglycan complex causes muscular dystrophies, and δ-sarcoglycan is a component of this complex, we hypothesized that resveratrol might be a new therapeutic tool for muscular dystrophies. Here, we examined resveratrol's effect in mdx mice, an animal model of Duchenne muscular dystrophy. mdx mice that received resveratrol in the diet for 32 weeks (4 g/kg diet) showed significantly less muscle mass loss and nonmuscle interstitial tissue in the biceps femoris compared with mdx mice fed a control diet. In the muscles of these mice, resveratrol significantly decreased oxidative damage shown by the immunostaining of nitrotyrosine and 8-hydroxy-2'-deoxyguanosine and suppressed the up-regulation of NADPH oxidase subunits Nox4, Duox1, and p47(phox). Resveratrol also reduced the number of α-smooth muscle actin (α-SMA)(+) myofibroblast cells and endomysial fibrosis in the biceps femoris, although the infiltration of CD45(+) inflammatory cells and increase in transforming growth factor-β1 (TGF-β1) were still observed. In C2C12 myoblast cells, resveratrol pretreatment suppressed the TGF-β1-induced increase in reactive oxygen species, fibronectin production, and expression of α-SMA, and SIRT1 knockdown blocked these inhibitory effects. SIRT1 small interfering RNA also increased the expression of Nox4, p47(phox), and α-SMA in C2C12 cells. Taken together, these findings indicate that SIRT1 activation may be a useful strategy for treating muscular dystrophies.

Topics: Animals; Antioxidants; Blotting, Western; Cell Differentiation; Cell Line; Creatine Kinase; Electroporation; Fibroblasts; Fibrosis; Histones; Immunohistochemistry; Indicators and Reagents; L-Lactate Dehydrogenase; Mice; Mice, Inbred mdx; Muscle, Skeletal; Muscular Dystrophy, Duchenne; Oxidative Stress; Reactive Oxygen Species; Resveratrol; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering; Sirtuin 1; Stilbenes