Pharmacological activation of SERCA ameliorates dystrophic phenotypes in dystrophin-deficient mdx mice

Abstract Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder characterized by progressive muscular weakness due to the loss of dystrophin. Extracellular Ca2+ flows into the cytoplasm through membrane tears in dystrophin-deficient myofibers, which leads to muscle contracture and necrosis. Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) takes up cytosolic Ca2+ into the sarcoplasmic reticulum (SR), but its activity is decreased in dystrophic muscle. Here, we show that an allosteric SERCA activator, CDN1163, ameliorates dystrophic phenotypes in dystrophin-deficient mdx mice. Administration of CDN1163 prevented exercise-induced muscular damage and restored mitochondrial function. In addition, treatment with CDN1163 for seven weeks enhanced muscular strength and reduced muscular degeneration and fibrosis in mdx mice. Our findings provide preclinical proof-of-concept evidence that pharmacological activation of SERCA could be a promising therapeutic strategy for DMD. Moreover, CDN1163 improved muscular strength surprisingly in wild-type mice, which may pave the new way for the treatment of muscular dysfunction.

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Effects of PDE5 inhibition on dystrophic muscle following an acute bout of downhill running and endurance training

Journal of Applied Physiology ◽

10.1152/japplphysiol.00664.2018 ◽

2019 ◽

Vol 126 (6) ◽

pp. 1737-1745 ◽

Cited By ~ 4

Author(s):

Abhinandan Batra ◽

Ravneet S. Vohra ◽

Steve M. Chrzanowski ◽

David W. Hammers ◽

Donovan J. Lott ◽

...

Keyword(s):

Endurance Training ◽

Muscle Damage ◽

Mdx Mice ◽

Wild Type ◽

Dystrophic Muscle ◽

Acute Bout ◽

Pde5 Inhibition ◽

Downhill Running ◽

Single Bout ◽

Dystrophic Mice

Lack of sarcolemma-localized neuronal nitric oxide synthase mu (nNOSμ) contributes to muscle damage and fatigue in dystrophic muscle. In this study, we examined the effects of compensating for lack of nNOSμ with a phosphodiesterase type 5 (PDE5) inhibitor in mdx mice following downhill running and endurance training. Dystrophic mice ( mdx) were treated with sildenafil citrate and compared with untreated mdx and wild-type mice after an acute bout of downhill running and during a progressive low-intensity treadmill running program (5 days/wk, 4 wk). Magnetic resonance imaging (MRI) and spectroscopy (MRS) transverse relaxation time constant (T2) of hindlimb and forelimb muscles were measured as a marker of muscle damage after downhill running and throughout training. The MRI blood oxygenation level dependence (BOLD) response and 31phosphorus MRS (31P-MRS) data were acquired after stimulated muscle contractions. After downhill running, the increase in T2 was attenuated ( P < 0.05) in treated mdx and wild-type mice compared with untreated mdx. During training, resting T2 values did not change in wild-type and mdx mice from baseline values; however, the running distance completed during training was greater ( P < 0.05) in treated mdx (>90% of target distance) and wild-type (100%) than untreated mdx (60%). The post-contractile BOLD response was greater ( P < 0.05) in treated mdx that trained than untreated mdx, with no differences in muscle oxidative capacity, as measured by 31P-MRS. Our findings indicate that PDE5 inhibition reduces muscle damage after a single bout of downhill running and improves performance during endurance training in dystrophic mice, possibly because of enhanced microvascular function. NEW & NOTEWORTHY This study examined the combined effects of PDE5 inhibition and exercise in dystrophic muscle using high-resolution magnetic resonance imaging and spectroscopy. Our findings demonstrated that sildenafil citrate reduces muscle damage after a single bout of downhill running, improves endurance-training performance, and enhances microvascular function in dystrophic muscle. Collectively, the results support the combination of exercise and PDE5 inhibition as a therapeutic approach in muscular dystrophies lacking nNOSμ.

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Inhibition of gut- and lung-derived serotonin attenuates pulmonary hypertension in mice

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00049.2012 ◽

2012 ◽

Vol 303 (6) ◽

pp. L500-L508 ◽

Cited By ~ 20

Author(s):

Shariq Abid ◽

Amal Houssaini ◽

Caroline Chevarin ◽

Elisabeth Marcos ◽

Claire-Marie Tissot ◽

...

Keyword(s):

Pulmonary Hypertension ◽

Therapeutic Strategy ◽

Tryptophan Hydroxylase ◽

Combined Treatment ◽

Systolic Pressure ◽

Adjunctive Treatment ◽

Proof Of Concept ◽

Wild Type ◽

Rate Limiting ◽

The Brain

Decreasing the bioavailability of serotonin (5-HT) by inhibiting its biosynthesis may represent a useful adjunctive treatment of pulmonary hypertension (PH). We assessed this hypothesis using LP533401, which inhibits the rate-limiting enzyme tryptophan hydroxylase 1 (Tph1) expressed in the gut and lung, without inhibiting Tph2 expressed in neurons. Mice treated repeatedly with LP533401 (30–250 mg/kg per day) exhibited marked 5-HT content reductions in the gut, lungs, and blood, but not in the brain. After a single LP533401 dose (250 mg/kg), lung and gut 5-HT contents decreased by 50%, whereas blood 5-HT levels remained unchanged, suggesting gut and lung 5-HT synthesis. Treatment with the 5-HT transporter (5-HTT) inhibitor citalopram decreased 5-HT contents in the blood and lungs but not in the gut. In transgenic SM22-5-HTT+ mice, which overexpress 5-HTT in smooth muscle cells and spontaneously develop PH, 250 mg/kg per day LP533401 or 10 mg/kg per day citalopram for 21 days markedly reduced lung and blood 5-HT levels, right ventricular (RV) systolic pressure, RV hypertrophy, distal pulmonary artery muscularization, and vascular Ki67-positive cells ( P < 0.001). Combined treatment with both drugs was more effective in improving PH-related hemodynamic parameters than either drug alone. LP533401 or citalopram treatment partially prevented PH development in wild-type mice exposed to chronic hypoxia. Lung and blood 5-HT levels were lower in hypoxic than in normoxic mice and decreased further after LP533401 or citalopram treatment. These results provide proof of concept that inhibiting Tph1 may represent a new therapeutic strategy for human PH.

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P4.22 In vivo decrease of elevated protein thiol oxidation and protection of dystrophic muscle from exercise induced damage, using the thiol containing antioxidant N-acetylcysteine in dystrophic mdx mice

Neuromuscular Disorders ◽

10.1016/j.nmd.2011.06.987 ◽

2011 ◽

Vol 21 (9-10) ◽

pp. 710-711

Author(s):

J.R. Terrill ◽

H.G. Radley-Crabb ◽

M.D. Grounds ◽

P.G. Arthur

Keyword(s):

Mdx Mice ◽

Thiol Oxidation ◽

Protein Thiol ◽

Dystrophic Muscle ◽

Elevated Protein ◽

Exercise Induced ◽

Protein Thiol Oxidation

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Wild-type FUS corrects ALS-like disease induced by cytoplasmic mutant FUS through autoregulation

10.1101/2020.12.16.423060 ◽

2020 ◽

Author(s):

Inmaculada Sanjuan-Ruiz ◽

Noé Govea-Perez ◽

Melissa Mcalonis-Downes ◽

Stéphane Dieterle ◽

Salim Megat ◽

...

Keyword(s):

Therapeutic Strategy ◽

Rna Binding ◽

Rna Binding Protein ◽

Motor Deficit ◽

Proof Of Concept ◽

Wild Type ◽

Age Dependent ◽

Early Lethality ◽

Lateral Sclerosis ◽

Fus Protein

AbstractMutations in FUS, an RNA-binding protein involved in multiple steps of RNA metabolism, are associated with the most severe forms of amyotrophic lateral sclerosis (ALS). Accumulation of cytoplasmic FUS is likely to be a major culprit in the toxicity of FUS mutations. Thus, preventing cytoplasmic mislocalization of the FUS protein may represent a valuable therapeutic strategy. FUS binds to its own pre-mRNA creating an autoregulatory loop efficiently buffering FUS excess through multiple proposed mechanisms including retention of introns 6 and/or 7. Here, we introduced a wild-type FUS gene allele, retaining all intronic sequences, in mice whose heterozygous or homozygous expression of a cytoplasmically retained FUS protein (FusΔNLS) was previously shown to provoke ALS-like disease or postnatal lethality, respectively. Wild-type FUS completely rescued the early lethality caused by the two FusΔNLS alleles, and improved age-dependent motor deficit and reduced lifespan associated with the heterozygous expression of FusΔNLS. Mechanistically, wild-type FUS decreased the load of cytoplasmic FUS, increased exon 7 skipping and retention of introns 6 and 7 in the endogenous mouse Fus mRNA, leading to decreased expression of the mutant mRNA. Thus, the wild-type FUS allele activates the homeostatic autoregulatory loop, maintaining constant FUS levels and decreasing the mutant protein in the cytoplasm. These results provide proof of concept that an autoregulatory competent wild-type FUS expression could protect against this devastating, currently intractable, neurodegenerative disease.

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Resveratrol Promotes Hypertrophy in Wildtype Skeletal Muscle and Reduces Muscle Necrosis and Gene Expression of Inflammatory Markers in Mdx Mice

Molecules ◽

10.3390/molecules26040853 ◽

2021 ◽

Vol 26 (4) ◽

pp. 853

Author(s):

Keryn G. Woodman ◽

Chantal A. Coles ◽

Shireen R. Lamandé ◽

Jason D. White

Keyword(s):

Gene Expression ◽

Skeletal Muscle ◽

Immune Cell ◽

Neuromuscular Disorder ◽

Voluntary Exercise ◽

Mdx Mice ◽

Dystrophic Muscle ◽

Cell Markers ◽

Muscle Necrosis ◽

Exercise Induced

Duchenne muscular dystrophy (DMD) is a progressive fatal neuromuscular disorder with no cure. Therapies to restore dystrophin deficiency have been approved in some jurisdictions but long-term effectiveness is yet to be established. There is a need to develop alternative strategies to treat DMD. Resveratrol is a nutraceutical with anti-inflammatory properties. Previous studies have shown high doses (100–400 mg/kg bodyweight/day) benefit mdx mice. We treated 4-week-old mdx and wildtype mice with a lower dose of resveratrol (5 mg/kg bodyweight/day) for 15 weeks. Voluntary exercise was used to test if a lower dosage than previously tested could reduce exercise-induced damage where a greater inflammatory infiltrate is present. We found resveratrol promoted skeletal muscle hypertrophy in wildtype mice. In dystrophic muscle, resveratrol reduced exercise-induced muscle necrosis. Gene expression of immune cell markers, CD86 and CD163 were reduced; however, signalling targets associated with resveratrol’s mechanism of action including Sirt1 and NF-κB were unchanged. In conclusion, a lower dose of resveratrol compared to the dosage used by other studies reduced necrosis and gene expression of inflammatory cell markers in dystrophic muscle suggesting it as a therapeutic candidate for treating DMD.

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Wild-type FUS corrects ALS-like disease induced by cytoplasmic mutant FUS through autoregulation

Molecular Neurodegeneration ◽

10.1186/s13024-021-00477-w ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Inmaculada Sanjuan-Ruiz ◽

Noé Govea-Perez ◽

Melissa McAlonis-Downes ◽

Stéphane Dieterle ◽

Salim Megat ◽

...

Keyword(s):

Therapeutic Strategy ◽

Rna Binding ◽

Rna Binding Protein ◽

Motor Deficits ◽

Proof Of Concept ◽

Wild Type ◽

Age Dependent ◽

Early Lethality ◽

Lateral Sclerosis ◽

Fus Protein

AbstractMutations in FUS, an RNA-binding protein involved in multiple steps of RNA metabolism, are associated with the most severe forms of amyotrophic lateral sclerosis (ALS). Accumulation of cytoplasmic FUS is likely to be a major culprit in the toxicity of FUS mutations. Thus, preventing cytoplasmic mislocalization of the FUS protein may represent a valuable therapeutic strategy. FUS binds to its own pre-mRNA creating an autoregulatory loop efficiently buffering FUS excess through multiple proposed mechanisms including retention of introns 6 and/or 7. Here, we introduced a wild-type FUS gene allele, retaining all intronic sequences, in mice whose heterozygous or homozygous expression of a cytoplasmically retained FUS protein (Fus∆NLS) was previously shown to provoke ALS-like disease or postnatal lethality, respectively. Wild-type FUS completely rescued the early lethality caused by the two Fus∆NLS alleles, and improved the age-dependent motor deficits and reduced lifespan caused by heterozygous expression of mutant FUS∆NLS. Mechanistically, wild-type FUS decreased the load of cytoplasmic FUS, increased retention of introns 6 and 7 in the endogenous mouse Fus mRNA, and decreased expression of the mutant mRNA. Thus, the wild-type FUS allele activates the homeostatic autoregulatory loop, maintaining constant FUS levels and decreasing the mutant protein in the cytoplasm. These results provide proof of concept that an autoregulatory competent wild-type FUS expression could protect against this devastating, currently intractable, neurodegenerative disease.

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Twenty-one days of low-intensity eccentric training improve morphological characteristics and function of soleus muscles of mdx mice

Scientific Reports ◽

10.1038/s41598-020-79168-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Paulo S. Pedrazzani ◽

Tatiana O. P. Araújo ◽

Emilly Sigoli ◽

Isabella R. da Silva ◽

Daiane Leite da Roza ◽

...

Keyword(s):

Soleus Muscle ◽

Morphological Characteristics ◽

Training Group ◽

Mdx Mice ◽

Eccentric Training ◽

Active Force ◽

Wild Type ◽

Low Intensity ◽

Sedentary Group ◽

Group 3

AbstractDuchene muscular dystrophy (DMD) is caused by the absence of the protein dystrophin, which leads to muscle weakness, progressive degeneration, and eventually death due to respiratory failure. Low-intensity eccentric training (LIET) has been used as a rehabilitation method in skeletal muscles after disuse. Recently, LIET has also been used for rehabilitating dystrophic muscles, but its effects are still unclear. The purpose of this study was to investigate the effects of 21 days of LIET in dystrophic soleus muscle. Thirty-six male mdx mice were randomized into six groups (n = 6/each): mdx sedentary group; mdx training group-3 days; mdx training group-21 days; wild-type sedentary group; wild-type training group-3 days and wild-type training group-21 days. After the training sessions, animals were euthanized, and fragments of soleus muscles were removed for immunofluorescence and histological analyses, and measurements of active force and Ca2+ sensitivity of the contractile apparatus. Muscles of the mdx training group-21 days showed an improvement in morphological characteristics and an increase of active force when compared to the sedentary mdx group. The results show that LIET can improve the functionality of dystrophic soleus muscle in mice.

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Apohemoglobin-haptoglobin complex attenuates the pathobiology of circulating acellular hemoglobin and heme

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00136.2020 ◽

2020 ◽

Vol 318 (5) ◽

pp. H1296-H1307 ◽

Cited By ~ 2

Author(s):

Carlos J. Munoz ◽

Ivan S. Pires ◽

Jin Hyen Baek ◽

Paul W. Buehler ◽

Andre F. Palmer ◽

...

Keyword(s):

Therapeutic Strategy ◽

Capillary Density ◽

Microvascular Blood Flow ◽

Systemic Hypertension ◽

Proof Of Concept ◽

Heme Transfer ◽

Ligand Transfer ◽

Novel Therapeutic

This study highlights the apoHb-Hp complex as a novel therapeutic strategy to attenuate the adverse systemic and microvascular responses to intravascular Hb and heme exposure. In vitro and in vivo Hb exchange and heme transfer experiments demonstrated proof-of-concept Hb/heme ligand transfer to apoHb-Hp. The apoHb-Hp complex reverses Hb- and heme-induced systemic hypertension and microvascular vasoconstriction, preserves microvascular blood flow, and functional capillary density. In summary, the unique properties of the apoHb-Hp complex prevent adverse systemic and microvascular responses to Hb and heme-albumin exposure and introduce a novel therapeutic approach to facilitate simultaneous removal of extracellular Hb and heme.

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