1
|
Franco-Obregón A, Tai YK. Are Aminoglycoside Antibiotics TRPing Your Metabolic Switches? Cells 2024; 13:1273. [PMID: 39120305 PMCID: PMC11311832 DOI: 10.3390/cells13151273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Revised: 07/26/2024] [Accepted: 07/27/2024] [Indexed: 08/10/2024] Open
Abstract
Transient receptor potential (TRP) channels are broadly implicated in the developmental programs of most tissues. Amongst these tissues, skeletal muscle and adipose are noteworthy for being essential in establishing systemic metabolic balance. TRP channels respond to environmental stimuli by supplying intracellular calcium that instigates enzymatic cascades of developmental consequence and often impinge on mitochondrial function and biogenesis. Critically, aminoglycoside antibiotics (AGAs) have been shown to block the capacity of TRP channels to conduct calcium entry into the cell in response to a wide range of developmental stimuli of a biophysical nature, including mechanical, electromagnetic, thermal, and chemical. Paradoxically, in vitro paradigms commonly used to understand organismal muscle and adipose development may have been led astray by the conventional use of streptomycin, an AGA, to help prevent bacterial contamination. Accordingly, streptomycin has been shown to disrupt both in vitro and in vivo myogenesis, as well as the phenotypic switch of white adipose into beige thermogenic status. In vivo, streptomycin has been shown to disrupt TRP-mediated calcium-dependent exercise adaptations of importance to systemic metabolism. Alternatively, streptomycin has also been used to curb detrimental levels of calcium leakage into dystrophic skeletal muscle through aberrantly gated TRPC1 channels that have been shown to be involved in the etiology of X-linked muscular dystrophies. TRP channels susceptible to AGA antagonism are critically involved in modulating the development of muscle and adipose tissues that, if administered to behaving animals, may translate to systemwide metabolic disruption. Regenerative medicine and clinical communities need to be made aware of this caveat of AGA usage and seek viable alternatives, to prevent contamination or infection in in vitro and in vivo paradigms, respectively.
Collapse
Affiliation(s)
- Alfredo Franco-Obregón
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Institute of Health Technology and Innovation (iHealthtech), National University of Singapore, Singapore 117599, Singapore
- BICEPS Lab (Biolonic Currents Electromagnetic Pulsing Systems), National University of Singapore, Singapore 117599, Singapore
- NUS Centre for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore
- Competence Center for Applied Biotechnology and Molecular Medicine, University of Zürich, 8057 Zürich, Switzerland
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore
| | - Yee Kit Tai
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Institute of Health Technology and Innovation (iHealthtech), National University of Singapore, Singapore 117599, Singapore
- BICEPS Lab (Biolonic Currents Electromagnetic Pulsing Systems), National University of Singapore, Singapore 117599, Singapore
- NUS Centre for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore
| |
Collapse
|
2
|
Iversen JN, Fröhlich J, Tai YK, Franco-Obregón A. Synergistic Cellular Responses Conferred by Concurrent Optical and Magnetic Stimulation Are Attenuated by Simultaneous Exposure to Streptomycin: An Antibiotic Dilemma. Bioengineering (Basel) 2024; 11:637. [PMID: 39061719 PMCID: PMC11274164 DOI: 10.3390/bioengineering11070637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 06/18/2024] [Accepted: 06/20/2024] [Indexed: 07/28/2024] Open
Abstract
Concurrent optical and magnetic stimulation (COMS) combines extremely low-frequency electromagnetic and light exposure for enhanced wound healing. We investigated the potential mechanistic synergism between the magnetic and light components of COMS by comparing their individual and combined cellular responses. Lone magnetic field exposure produced greater enhancements in cell proliferation than light alone, yet the combined effects of magnetic fields and light were supra-additive of the individual responses. Reactive oxygen species were incrementally reduced by exposure to light, magnetics fields, and their combination, wherein statistical significance was only achieved by the combined COMS modality. By contrast, ATP production was most greatly enhanced by magnetic exposure in combination with light, indicating that mitochondrial respiratory efficiency was improved by the combination of magnetic fields plus light. Protein expression pertaining to cell proliferation was preferentially enhanced by the COMS modality, as were the protein levels of the TRPC1 cation channel that had been previously implicated as part of a calcium-mitochondrial signaling axis invoked by electromagnetic exposure and necessary for proliferation. These results indicate that light facilitates functional synergism with magnetic fields that ultimately impinge on mitochondria-dependent developmental responses. Aminoglycoside antibiotics (AGAs) have been previously shown to inhibit TRPC1-mediated magnetotransduction, whereas their influence over photomodulation has not been explored. Streptomycin applied during exposure to light, magnetic fields, or COMS reduced their respective proliferation enhancements, whereas streptomycin added after the exposure did not. Magnetic field exposure and the COMS modality were capable of partially overcoming the antagonism of proliferation produced by streptomycin treatment, whereas light alone was not. The antagonism of photon-electromagnetic effects by streptomycin implicates TRPC1-mediated calcium entry in both magnetotransduction and photomodulation. Avoiding the prophylactic use of AGAs during COMS therapy will be crucial for maintaining clinical efficacy and is a common concern in most other electromagnetic regenerative paradigms.
Collapse
Affiliation(s)
- Jan Nikolas Iversen
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore;
- Institute of Health Technology and Innovation (iHealthtech), National University of Singapore, Singapore 117599, Singapore
- BICEPS Lab (Biolonic Currents Electromagnetic Pulsing Systems), National University of Singapore, Singapore 117599, Singapore
| | - Jürg Fröhlich
- Fields at Work GmbH, Hegibachstrasse 41, 8032 Zurich, Switzerland;
- Piomic Medical AG, Reitergasse 6, 8004 Zürich, Switzerland
| | - Yee Kit Tai
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore;
- Institute of Health Technology and Innovation (iHealthtech), National University of Singapore, Singapore 117599, Singapore
- BICEPS Lab (Biolonic Currents Electromagnetic Pulsing Systems), National University of Singapore, Singapore 117599, Singapore
- NUS Centre for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore
| | - Alfredo Franco-Obregón
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore;
- Institute of Health Technology and Innovation (iHealthtech), National University of Singapore, Singapore 117599, Singapore
- BICEPS Lab (Biolonic Currents Electromagnetic Pulsing Systems), National University of Singapore, Singapore 117599, Singapore
- NUS Centre for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore
- Competence Center for Applied Biotechnology and Molecular Medicine, University of Zürich, 8057 Zürich, Switzerland
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore
| |
Collapse
|
3
|
Kiriaev L, Baumann CW, Lindsay A. Eccentric contraction-induced strength loss in dystrophin-deficient muscle: Preparations, protocols, and mechanisms. J Gen Physiol 2023; 155:213810. [PMID: 36651896 PMCID: PMC9856740 DOI: 10.1085/jgp.202213208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/01/2022] [Accepted: 12/28/2022] [Indexed: 01/19/2023] Open
Abstract
The absence of dystrophin hypersensitizes skeletal muscle of lower and higher vertebrates to eccentric contraction (ECC)-induced strength loss. Loss of strength can be accompanied by transient and reversible alterations to sarcolemmal excitability and disruption, triad dysfunction, and aberrations in calcium kinetics and reactive oxygen species production. The degree of ECC-induced strength loss, however, appears dependent on several extrinsic and intrinsic factors such as vertebrate model, skeletal muscle preparation (in vivo, in situ, or ex vivo), skeletal muscle hierarchy (single fiber versus whole muscle and permeabilized versus intact), strength production, fiber branching, age, and genetic background, among others. Consistent findings across research groups show that dystrophin-deficient fast(er)-twitch muscle is hypersensitive to ECCs relative to wildtype muscle, but because preparations are highly variable and sensitivity to ECCs are used repeatedly to determine efficacy of many preclinical treatments, it is critical to evaluate the impact of skeletal muscle preparations on sensitivity to ECC-induced strength loss in dystrophin-deficient skeletal muscle. Here, we review and discuss variations in skeletal muscle preparations to evaluate the factors responsible for variations and discrepancies between research groups. We further highlight that dystrophin-deficiency, or loss of the dystrophin-glycoprotein complex in skeletal muscle, is not a prerequisite for accelerated strength loss-induced by ECCs.
Collapse
Affiliation(s)
- Leonit Kiriaev
- Muscle Research Group, Murdoch Children’s Research Institute, Parkville, Victoria, Australia,School of Medicine, Western Sydney University, Campbelltown, New South Wales, Australia
| | - Cory W. Baumann
- Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens, OH, USA,Department of Biomedical Sciences, Ohio University, Athens, OH, USA
| | - Angus Lindsay
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia,Correspondence to Angus Lindsay:
| |
Collapse
|
4
|
Su Y, Song Y. The new challenge of “exercise + X″ therapy for Duchenne muscular dystrophy—Individualized identification of exercise tolerance and precise implementation of exercise intervention. Front Physiol 2022; 13:947749. [PMID: 35991169 PMCID: PMC9389311 DOI: 10.3389/fphys.2022.947749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/07/2022] [Indexed: 12/05/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked recessive fatal muscular disease. Gene therapy, cell therapy, and drug therapy are currently the most widely used treatments for DMD. However, many experiments on animals and humans suggested that appropriate exercise could improve the effectiveness of such precision medicine treatment, thereby improving patient’s muscle quality and function. Due to the striated muscle damage of DMD individuals, there are still many debates about whether DMD animals or patients can exercise, how to exercise, when to exercise best, and how to exercise effectively. The purpose of this review is to summarize and investigate the scientific basis and efficacy of exercise as an adjuvant therapy for DMD gene therapy, cell therapy and drug therapy, as well as to present the theoretical framework and optional strategies of “exercise + X″″ combination therapy.
Collapse
Affiliation(s)
- Yuhui Su
- Department of Exercise Physiology, Beijing Sport University, Beijing, China
- Institute of Physical Education, Jilin Normal University, Siping, China
| | - Yafeng Song
- China Institute of Sport and Health Science, Beijing Sport University, Beijing, China
- *Correspondence: Yafeng Song,
| |
Collapse
|
5
|
Ashida Y, Himori K, Tokuda N, Naito A, Yamauchi N, Takenaka-Ninagawa N, Aoki Y, Sakurai H, Yamada T. Dissociation of SH3 and cysteine rich domain 3 and junctophilin 1 from dihydropyridine receptor in dystrophin-deficient muscles. Am J Physiol Cell Physiol 2022; 323:C885-C895. [PMID: 35912995 DOI: 10.1152/ajpcell.00163.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The disruption of excitation-contraction (EC) coupling and subsequent reduction in Ca2+ release from the sarcoplasmic reticulum (SR) have been shown to account for muscle weakness seen in patients with Duchenne muscular dystrophy (DMD). Here, we examined the mechanisms underlying EC uncoupling in skeletal muscles from mdx52 and DMD-null/NSG mice, animal models for DMD, focusing on the SH3 and cysteine rich domain 3 (STAC3) and junctophilin 1 (JP1), which link the dihydropyridine receptor (DHPR) in the transverse tubule and the ryanodine receptor 1 in the SR. The isometric plantarflexion torque normalized to muscle weight of whole plantar flexor muscles was depressed in mdx52 and DMD-null/NSG mice compared to their control mice. This was accompanied by increased autolysis of calpain-1, decreased levels of STAC3 and JP1 content, and dissociation of STAC3 and JP1 from DHPR-α1s in gastrocnemius muscles. Moreover, in vitro mechanistic experiments demonstrated that STAC3 and JP1 underwent Ca2+-dependent proteolysis which was less pronounced in dystrophin-deficient muscles where calpastatin, the endogenous calpain inhibitor, was upregulated. Eccentric contractions further enhanced autolysis of calpain-1 and proteolysis of STAC3 and JP1 that were associated with severe torque depression in gastrocnemius muscles from DMD-null/NSG mice. These data suggest that Ca2+-dependent proteolysis of STAC3 and JP1 may be an essential factor causing muscle weakness due to EC coupling failure in dystrophin-deficient muscles.
Collapse
Affiliation(s)
- Yuki Ashida
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan.,Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Koichi Himori
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan.,Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Nao Tokuda
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | - Azuma Naito
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | - Nao Yamauchi
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | | | - Yoshitsugu Aoki
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Hidetoshi Sakurai
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Takashi Yamada
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| |
Collapse
|
6
|
Kiriaev L, Kueh S, Morley JW, North KN, Houweling PJ, Head SI. Lifespan Analysis of Dystrophic mdx Fast-Twitch Muscle Morphology and Its Impact on Contractile Function. Front Physiol 2021; 12:771499. [PMID: 34950049 PMCID: PMC8689589 DOI: 10.3389/fphys.2021.771499] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 11/08/2021] [Indexed: 11/13/2022] Open
Abstract
Duchenne muscular dystrophy is caused by the absence of the protein dystrophin from skeletal muscle and is characterized by progressive cycles of necrosis/regeneration. Using the dystrophin deficient mdx mouse model, we studied the morphological and contractile chronology of dystrophic skeletal muscle pathology in fast-twitch Extensor Digitorum Longus muscles from animals 4–22 months of age containing 100% regenerated muscle fibers. Catastrophically, the older age groups lost ∼80% of their maximum force after one eccentric contraction (EC) of 20% strain with the greatest loss of ∼92% recorded in senescent 22-month-old mdx mice. In old age groups, there was minimal force recovery ∼24% after 120 min, correlated with a dramatic increase in the number and complexity of branched fibers. This data supports our two-phase model where a “tipping point” is reached when branched fibers rupture irrevocably on EC. These findings have important implications for pre-clinical drug studies and genetic rescue strategies.
Collapse
Affiliation(s)
- Leonit Kiriaev
- Myogenica Laboratory, School of Medicine, Western Sydney University, Sydney, NSW, Australia
- *Correspondence: Leonit Kiriaev,
| | - Sindy Kueh
- Myogenica Laboratory, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - John W. Morley
- Myogenica Laboratory, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Kathryn N. North
- Muscle Research Group, Murdoch Children’s Research Institute, Melbourne, VIC, Australia
| | - Peter J. Houweling
- Muscle Research Group, Murdoch Children’s Research Institute, Melbourne, VIC, Australia
| | - Stewart I. Head
- Myogenica Laboratory, School of Medicine, Western Sydney University, Sydney, NSW, Australia
- Muscle Research Group, Murdoch Children’s Research Institute, Melbourne, VIC, Australia
| |
Collapse
|
7
|
Baumann CW, Lindsay A, Sidky SR, Ervasti JM, Warren GL, Lowe DA. Contraction-Induced Loss of Plasmalemmal Electrophysiological Function Is Dependent on the Dystrophin Glycoprotein Complex. Front Physiol 2021; 12:757121. [PMID: 34764884 PMCID: PMC8576390 DOI: 10.3389/fphys.2021.757121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 10/05/2021] [Indexed: 02/03/2023] Open
Abstract
Weakness and atrophy are key features of Duchenne muscular dystrophy (DMD). Dystrophin is one of the many proteins within the dystrophin glycoprotein complex (DGC) that maintains plasmalemmal integrity and cellular homeostasis. The dystrophin-deficient mdx mouse is also predisposed to weakness, particularly when subjected to eccentric (ECC) contractions due to electrophysiological dysfunction of the plasmalemma. Here, we determined if maintenance of plasmalemmal excitability during and after a bout of ECC contractions is dependent on intact and functional DGCs rather than, solely, dystrophin expression. Wild-type (WT) and dystrophic mice (mdx, mL172H and Sgcb-/- mimicking Duchenne, Becker and Limb-girdle Type 2E muscular dystrophies, respectively) with varying levels of dystrophin and DGC functionality performed 50 maximal ECC contractions with simultaneous torque and electromyographic measurements (M-wave root-mean-square, M-wave RMS). ECC contractions caused all mouse lines to lose torque (p<0.001); however, deficits were greater in dystrophic mouse lines compared to WT mice (p<0.001). Loss of ECC torque did not correspond to a reduction in M-wave RMS in WT mice (p=0.080), while deficits in M-wave RMS exceeded 50% in all dystrophic mouse lines (p≤0.007). Moreover, reductions in ECC torque and M-wave RMS were greater in mdx mice compared to mL172H mice (p≤0.042). No differences were observed between mdx and Sgcb-/- mice (p≥0.337). Regression analysis revealed ≥98% of the variance in ECC torque loss could be explained by the variance in M-wave RMS in dystrophic mouse lines (p<0.001) but not within WT mice (R 2=0.211; p=0.155). By comparing mouse lines that had varying amounts and functionality of dystrophin and other DGC proteins, we observed that (1) when all DGCs are intact, plasmalemmal action potential generation and conduction is maintained, (2) deficiency of the DGC protein β-sarcoglycan is as disruptive to plasmalemmal excitability as is dystrophin deficiency and, (3) some functionally intact DGCs are better than none. Our results highlight the significant role of the DGC plays in maintaining plasmalemmal excitability and that a collective synergism (via each DGC protein) is required for this complex to function properly during ECC contractions.
Collapse
Affiliation(s)
- Cory W. Baumann
- Department of Biomedical Sciences, Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens, OH, United States
- Divisions of Rehabilitation Science and Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, United States
| | - Angus Lindsay
- Divisions of Rehabilitation Science and Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, United States
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition, Deakin University, Geelong, VIC, Australia
| | - Sylvia R. Sidky
- Divisions of Rehabilitation Science and Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, United States
| | - James M. Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - Gordon L. Warren
- Department of Physical Therapy, Georgia State University, Atlanta, GA, United States
| | - Dawn A. Lowe
- Divisions of Rehabilitation Science and Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, United States
| |
Collapse
|
8
|
Yao S, Chen Z, Yu Y, Zhang N, Jiang H, Zhang G, Zhang Z, Zhang B. Current Pharmacological Strategies for Duchenne Muscular Dystrophy. Front Cell Dev Biol 2021; 9:689533. [PMID: 34490244 PMCID: PMC8417245 DOI: 10.3389/fcell.2021.689533] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 07/23/2021] [Indexed: 12/25/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal, X-linked neuromuscular disorder caused by the absence of dystrophin protein, which is essential for muscle fiber integrity. Loss of dystrophin protein leads to recurrent myofiber damage, chronic inflammation, progressive fibrosis, and dysfunction of muscle stem cells. There is still no cure for DMD so far and the standard of care is principally limited to symptom relief through glucocorticoids treatments. Current therapeutic strategies could be divided into two lines. Dystrophin-targeted therapeutic strategies that aim at restoring the expression and/or function of dystrophin, including gene-based, cell-based and protein replacement therapies. The other line of therapeutic strategies aims to improve muscle function and quality by targeting the downstream pathological changes, including inflammation, fibrosis, and muscle atrophy. This review introduces the important developments in these two lines of strategies, especially those that have entered the clinical phase and/or have great potential for clinical translation. The rationale and efficacy of each agent in pre-clinical or clinical studies are presented. Furthermore, a meta-analysis of gene profiling in DMD patients has been performed to understand the molecular mechanisms of DMD.
Collapse
Affiliation(s)
- Shanshan Yao
- School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Zihao Chen
- School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Yuanyuan Yu
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Kowloon, Hong Kong
| | - Ning Zhang
- School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Hewen Jiang
- School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Ge Zhang
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Kowloon, Hong Kong
| | - Zongkang Zhang
- School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Baoting Zhang
- School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| |
Collapse
|
9
|
Beneficial Role of Exercise in the Modulation of mdx Muscle Plastic Remodeling and Oxidative Stress. Antioxidants (Basel) 2021; 10:antiox10040558. [PMID: 33916762 PMCID: PMC8066278 DOI: 10.3390/antiox10040558] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/02/2021] [Accepted: 03/15/2021] [Indexed: 12/15/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked recessive progressive lethal disorder caused by the lack of dystrophin, which determines myofibers mechanical instability, oxidative stress, inflammation, and susceptibility to contraction-induced injuries. Unfortunately, at present, there is no efficient therapy for DMD. Beyond several promising gene- and stem cells-based strategies under investigation, physical activity may represent a valid noninvasive therapeutic approach to slow down the progression of the pathology. However, ethical issues, the limited number of studies in humans and the lack of consistency of the investigated training interventions generate loss of consensus regarding their efficacy, leaving exercise prescription still questionable. By an accurate analysis of data about the effects of different protocol of exercise on muscles of mdx mice, the most widely-used pre-clinical model for DMD research, we found that low intensity exercise, especially in the form of low speed treadmill running, likely represents the most suitable exercise modality associated to beneficial effects on mdx muscle. This protocol of training reduces muscle oxidative stress, inflammation, and fibrosis process, and enhances muscle functionality, muscle regeneration, and hypertrophy. These conclusions can guide the design of appropriate studies on human, thereby providing new insights to translational therapeutic application of exercise to DMD patients.
Collapse
|
10
|
Bukovec KE, Hu X, Borkowski M, Jeffery D, Blemker SS, Grange RW. A novel ex vivo protocol to mimic human walking gait: implications for Duchenne muscular dystrophy. J Appl Physiol (1985) 2020; 129:779-791. [PMID: 32881620 PMCID: PMC7654698 DOI: 10.1152/japplphysiol.00002.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 08/25/2020] [Accepted: 08/31/2020] [Indexed: 01/16/2023] Open
Abstract
We developed a novel ex vivo mouse protocol to mimic in vivo human soleus muscle function predicted by musculoskeletal simulations to better understand eccentric contractions during gait and ultimately to better understand their effects in Duchenne muscular dystrophy (DMD) muscles. DMD muscles are susceptible to eccentric injury because the protein dystrophin is absent. The mdx mouse, a DMD model that also lacks dystrophin, is often subjected to ex vivo acute but nonphysiological eccentric injury protocols. It is possible these acute protocols either over- or underestimate eccentric stresses and strains compared with those from humans during gait. To explore this possibility, healthy human soleus excitation, force, and length change profiles during a single walking stride (gait cycle) were simulated using OpenSim and then scaled to an ex vivo mouse soleus preparation based on muscle architectural measurements. Aurora Scientific, Inc., software and a 701C electrical stimulator were modified to discretely modulate muscle stimulation voltage at constant frequency and finely control muscle length changes to produce a force pattern that correctly mimicked the gait cycle from simulations. In a proof-of-principle study, wild-type and mdx mice soleus muscles were subjected to 25 gait cycles. Modest fatigue was evident in the muscles at the 25th versus first gait cycle for both genotypes, but both rapidly recovered isometric force within 1 min of the last cycle. These data indicate that the ex vivo gait protocol was well tolerated. More important, this protocol provides a novel assessment tool to determine the effects of physiological eccentric contractions on dystrophic muscle.NEW & NOTEWORTHY A novel ex vivo mouse soleus protocol that mimics scaled length change and excitation profiles predicted by a mathematical model of human soleus during gait is presented. A custom stimulator was developed that enabled an innovative muscle stimulation technique to modulate voltage to closely match the excitation pattern of human soleus during gait. This ex vivo protocol provides assessment of simulated human movement in mouse muscle, including components of eccentric contractions.
Collapse
Affiliation(s)
- Katherine E Bukovec
- Department of Human Nutrition, Foods, and Exercise and Metabolism Core, Virginia Tech, Blacksburg, Virginia
| | - Xiao Hu
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | | | | | - Silvia S Blemker
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
- Department of Orthopedic Surgery, University of Virginia, Charlottesville, Virginia
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia
| | - Robert W Grange
- Department of Human Nutrition, Foods, and Exercise and Metabolism Core, Virginia Tech, Blacksburg, Virginia
| |
Collapse
|
11
|
MRI Quantitative Analysis of Eccentric Exercise-induced Skeletal Muscle Injury in Rats. Acad Radiol 2020; 27:e72-e79. [PMID: 31300358 DOI: 10.1016/j.acra.2019.05.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/13/2019] [Accepted: 05/17/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND The aim of this study was to investigate the value of magnetic resonance (MR) quantitative analysis (MR-T2 mapping technique) for the evaluation of eccentric exercise-induced skeletal muscle injury. MATERIALS AND METHODS We established an animal model of eccentric exercise-induced damage of Sprague Dawley rat skeletal muscle and evaluated the animals by MR imaging, determined the serum levels of fast skeletal troponin (fsTnI), and examined muscle histopathology, at 0, 1, 2, 4, and 7 days after eccentric exercise. The associations between MR imaging findings, and histopathological and laboratory results were evaluated. RESULTS T2-weighted images (WIs) of quadriceps femoris muscles showed obvious high signal intensities after exercise, and the T2 values and serum fsTnI levels continued to increase, peaking at day 2 after exercise, p< 0.05. The histopathological findings in muscle specimens, which included swollen and ruptured cells, enlarged extracellular spaces, inflammation, and regeneration of muscle fibers, showed similar trends. After day 2, muscle specimens began to show evidence of self-repair, the T2WI signals decreased in intensity, and the T2 values and serum fsTnI levels decreased; however, at day 7 post injury, the values remained slightly higher than those in the control animals, p< 0.05. The T2 value was significantly correlated with the serum fsTnI level (r = 0.896, p< 0.01). CONCLUSION T2 mapping technology accurately reflects the histopathological and fsTnI abnormalities and the degree of skeletal muscle damage associated with eccentric exercise followed by recovery. Because T2 mapping technology is noninvasive and can be quantitatively analyzed, it might become the preferred method for performing the diagnosis of eccentric exercise-induced skeletal muscle injury.
Collapse
|
12
|
Widrick JJ, Kawahara G, Alexander MS, Beggs AH, Kunkel LM. Discovery of Novel Therapeutics for Muscular Dystrophies using Zebrafish Phenotypic Screens. J Neuromuscul Dis 2020; 6:271-287. [PMID: 31282429 PMCID: PMC6961982 DOI: 10.3233/jnd-190389] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The recent availability and development of mutant and transgenic zebrafish strains that model human muscular dystrophies has created new research opportunities for therapeutic development. Not only do these models mimic many pathological aspects of human dystrophies, but their small size, large clutch sizes, rapid ex utero development, body transparency, and genetic tractability enable research approaches that would be inconceivable with mammalian model systems. Here we discuss the use of zebrafish models of muscular dystrophy to rapidly screen hundreds to thousands of bioactive compounds in order to identify novel therapeutic candidates that modulate pathologic phenotypes. We review the justification and rationale behind this unbiased approach, including how zebrafish screens have identified FDA-approved drugs that are candidates for treating Duchenne and limb girdle muscular dystrophies. Not only can these drugs be re-purposed for treating dystrophies in a fraction of the time and cost of new drug development, but their identification has revealed novel, unexpected directions for future therapy development. Phenotype-driven zebrafish drug screens are an important compliment to the more established mammalian, target-based approaches for rapidly developing and validating therapeutics for muscular dystrophies.
Collapse
Affiliation(s)
- Jeffrey J Widrick
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Genri Kawahara
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Matthew S Alexander
- Department of Pediatrics, Division of Neurology at the University of Alabama at Birmingham and Children's of Alabama; University of Alabama at Birmingham Center for Exercise Medicine; University of Alabama at Birmingham Civitan International Research Center; University of Alabama at Birmingham Department of Genetics; Birmingham, Alabama, USA
| | - Alan H Beggs
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Louis M Kunkel
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA.,Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
| |
Collapse
|
13
|
Lindsay A, Baumann CW, Rebbeck RT, Yuen SL, Southern WM, Hodges JS, Cornea RL, Thomas DD, Ervasti JM, Lowe DA. Mechanical factors tune the sensitivity of mdx muscle to eccentric strength loss and its protection by antioxidant and calcium modulators. Skelet Muscle 2020; 10:3. [PMID: 32007101 PMCID: PMC6995146 DOI: 10.1186/s13395-020-0221-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 01/09/2020] [Indexed: 12/17/2022] Open
Abstract
Background Dystrophin deficiency sensitizes skeletal muscle of mice to eccentric contraction (ECC)-induced strength loss. ECC protocols distinguish dystrophin-deficient from healthy, wild type muscle, and test the efficacy of therapeutics for Duchenne muscular dystrophy (DMD). However, given the large lab-to-lab variability in ECC-induced strength loss of dystrophin-deficient mouse skeletal muscle (10–95%), mechanical factors of the contraction likely impact the degree of loss. Therefore, the purpose of this study was to evaluate the extent to which mechanical variables impact sensitivity of dystrophin-deficient mouse skeletal muscle to ECC. Methods We completed ex vivo and in vivo muscle preparations of the dystrophin-deficient mdx mouse and designed ECC protocols within physiological ranges of contractile parameters (length change, velocity, contraction duration, and stimulation frequencies). To determine whether these contractile parameters affected known factors associated with ECC-induced strength loss, we measured sarcolemmal damage after ECC as well as strength loss in the presence of the antioxidant N-acetylcysteine (NAC) and small molecule calcium modulators that increase SERCA activity (DS-11966966 and CDN1163) or lower calcium leak from the ryanodine receptor (Chloroxine and Myricetin). Results The magnitude of length change, work, and stimulation duration ex vivo and in vivo of an ECC were the most important determinants of strength loss in mdx muscle. Passive lengthening and submaximal stimulations did not induce strength loss. We further showed that sarcolemmal permeability was associated with muscle length change, but it only accounted for a minimal fraction (21%) of the total strength loss (70%). The magnitude of length change also significantly influenced the degree to which NAC and small molecule calcium modulators protected against ECC-induced strength loss. Conclusions These results indicate that ECC-induced strength loss of mdx skeletal muscle is dependent on the mechanical properties of the contraction and that mdx muscle is insensitive to ECC at submaximal stimulation frequencies. Rigorous design of ECC protocols is critical for effective use of strength loss as a readout in evaluating potential therapeutics for muscular dystrophy.
Collapse
Affiliation(s)
- Angus Lindsay
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, MMC 388, 420 Delaware Street SE, Minneapolis, 55455, USA.,Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 6-155 Jackson Hall, 321 Church Street SE, Minneapolis, 55455, USA.,Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, 3220, Australia
| | - Cory W Baumann
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, MMC 388, 420 Delaware Street SE, Minneapolis, 55455, USA
| | - Robyn T Rebbeck
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 6-155 Jackson Hall, 321 Church Street SE, Minneapolis, 55455, USA
| | - Samantha L Yuen
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 6-155 Jackson Hall, 321 Church Street SE, Minneapolis, 55455, USA
| | - William M Southern
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 6-155 Jackson Hall, 321 Church Street SE, Minneapolis, 55455, USA
| | - James S Hodges
- Division of Biostatistics, University of Minnesota, A460 Mayo Building, 420 Delaware Street SE, Minneapolis, 55455, USA
| | - Razvan L Cornea
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 6-155 Jackson Hall, 321 Church Street SE, Minneapolis, 55455, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 6-155 Jackson Hall, 321 Church Street SE, Minneapolis, 55455, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 6-155 Jackson Hall, 321 Church Street SE, Minneapolis, 55455, USA
| | - Dawn A Lowe
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, MMC 388, 420 Delaware Street SE, Minneapolis, 55455, USA.
| |
Collapse
|
14
|
Trajanovska S, Ban J, Huang J, Gregorevic P, Morsch M, Allen DG, Phillips WD. Muscle specific kinase protects dystrophic mdx mouse muscles from eccentric contraction-induced loss of force-producing capacity. J Physiol 2019; 597:4831-4850. [PMID: 31340406 DOI: 10.1113/jp277839] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 07/17/2019] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS Adeno-associated viral vector was used to elevate the expression of muscle specific kinase (MuSK) and rapsyn (a cytoplasmic MuSK effector protein) in the tibialis anterior muscle of wild-type and dystrophic (mdx) mice. In mdx mice, enhanced expression of either MuSK or rapsyn ameliorated the acute loss of muscle force associated with strain injury. Increases in sarcolemmal immunolabelling for utrophin and β-dystroglycan suggest a mechanism for the protective effect of MuSK in mdx muscles. MuSK also caused subtle changes to the structure and function of the neuromuscular junction, suggesting novel roles for MuSK in muscle physiology and pathophysiology. ABSTRACT Muscle specific kinase (MuSK) has a well-defined role in stabilizing the developing mammalian neuromuscular junction, but MuSK might also be protective in some neuromuscular diseases. In the dystrophin-deficient mdx mouse model of Duchenne muscular dystrophy, limb muscles are especially fragile. We injected the tibialis anterior muscle of 8-week-old mdx and wild-type (C57BL10) mice with adeno-associated viral vectors encoding either MuSK or rapsyn (a cytoplasmic MuSK effector protein) fused to green fluorescent protein (MuSK-GFP and rapsyn-GFP, respectively). Contralateral muscles injected with empty vector served as controls. One month later mice were anaesthetized with isoflurane and isometric force-producing capacity was recorded from the distal tendon. MuSK-GFP caused an unexpected decay in nerve-evoked tetanic force, both in wild-type and mdx muscles, without affecting contraction elicited by direct electrical stimulation of the muscle. Muscle fragility was probed by challenging muscles with a strain injury protocol consisting of a series of four strain-producing eccentric contractions in vivo. When applied to muscles of mdx mice, eccentric contraction produced an acute 27% reduction in directly evoked muscle force output, affirming the susceptibility of mdx muscles to strain injury. mdx muscles overexpressing MuSK-GFP or rapsyn-GFP exhibited significantly milder force deficits after the eccentric contraction challenge (15% and 14%, respectively). The protective effect of MuSK-GFP in muscles of mdx mice was associated with increased immunolabelling for utrophin and β-dystroglycan in the sarcolemma. Elevating the expression of MuSK or rapsyn revealed several distinct synaptic and extrasynaptic effects, suggesting novel roles for MuSK signalling in muscle physiology and pathophysiology.
Collapse
Affiliation(s)
- S Trajanovska
- Physiology and Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| | - J Ban
- Physiology and Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| | - J Huang
- Physiology and Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| | - P Gregorevic
- Department of Physiology, The University of Melbourne, Melbourne, Victoria, Australia.,Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, Australia.,Department of Neurology, University of Washington School of Medicine, Seattle, WA, USA
| | - M Morsch
- Department of Biomedical Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - D G Allen
- Physiology and Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| | - W D Phillips
- Physiology and Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| |
Collapse
|
15
|
Abstract
INTRODUCTION Duchenne muscular dystrophy (DMD) is a neuromuscular disease caused by a dystrophin protein deficiency. Dystrophin functions to stabilize and protect the muscle fiber during muscle contraction; thus, the absence of functional dystrophin protein leads to muscle injury. DMD patients experience progressive muscle necrosis, loss of function, and ultimately succumb to respiratory failure or cardiomyopathy. Exercise is known to improve muscle health and strength in healthy individuals as well as positively affect other systems. Because of this, exercise has been investigated as a potential therapeutic approach for DMD. METHODS This review aims to provide a concise presentation of the exercise literature with a focus on dystrophin-deficient muscle. Our intent was to identify trends and gaps in knowledge with an appreciation of exercise modality. RESULTS After compiling data from mouse and human studies, it became apparent that endurance exercises such as a swimming and voluntary wheel running have therapeutic potential in limb muscles of mice and respiratory training was beneficial in humans. However, in the comparatively few long-term investigations, the effect of low-intensity training on cardiac and respiratory muscles was contradictory. In addition, the effect of exercise on other systems is largely unknown. CONCLUSIONS To safely prescribe exercise as a therapy to DMD patients, multisystemic investigations are needed including the evaluation of respiratory and cardiac muscle.
Collapse
|
16
|
GsMTx4-D provides protection to the D2.mdx mouse. Neuromuscul Disord 2018; 28:868-877. [PMID: 30174173 DOI: 10.1016/j.nmd.2018.07.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 07/02/2018] [Accepted: 07/17/2018] [Indexed: 12/23/2022]
Abstract
Duchenne muscular dystrophy is a life-limiting muscle disease that has no current effective therapy. Despite mounting evidence that dysregulation of mechanosensitive ion channels is a significant contributor to dystrophy pathogenesis, effective pharmacologic strategies targeting these channels are lacking. GsMTx4, and its enantiomer GsMTx4-D, are peptide inhibitors of mechanosensitive channels with identical activity. In previous studies, acute in vitro application of GsMTx4 to dystrophic murine muscle effectively reduced the excess MSC dependent calcium influx linked to contraction-induced muscle damage. Here we sought to determine if in vivo treatment with GsMTx4-D proffered benefit in the D2.mdx mouse. GsMTx4-D showed a 1-week half-life when administered by subcutaneous injection over four weeks. Informed by these results, D2.mdx mice were then treated by a subcutaneous injection regimen of GsMTx4-D for six weeks followed by determination of muscle mass, muscle susceptibility to eccentric contraction injury and multiple histological indicators of disease progression. The mice showed a reduction in the loss of muscle mass and a decrease in susceptibility to contraction induced injury. These protective effects were realized without reduction in fibrosis, supporting a model where GsMTx4-D acts directly on muscle cells. We propose GsMTx4-D represents a promising new therapy to slow disease progression and may complement other therapies such as anti-inflammatory agents and gene-replacement strategies.
Collapse
|
17
|
Ismail HM, Dorchies OM, Scapozza L. The potential and benefits of repurposing existing drugs to treat rare muscular dystrophies. Expert Opin Orphan Drugs 2018. [DOI: 10.1080/21678707.2018.1452733] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Hesham M. Ismail
- Pharmaceutical Biochemistry, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, CMU, Geneva, Switzerland
| | - Olivier M. Dorchies
- Pharmaceutical Biochemistry, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, CMU, Geneva, Switzerland
| | - Leonardo Scapozza
- Pharmaceutical Biochemistry, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, CMU, Geneva, Switzerland
| |
Collapse
|
18
|
Transient receptor potential channel 6 regulates abnormal cardiac S-nitrosylation in Duchenne muscular dystrophy. Proc Natl Acad Sci U S A 2017; 114:E10763-E10771. [PMID: 29187535 DOI: 10.1073/pnas.1712623114] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked disorder with dystrophin loss that results in skeletal and cardiac muscle weakening and early death. Loss of the dystrophin-sarcoglycan complex delocalizes nitric oxide synthase (NOS) to alter its signaling, and augments mechanosensitive intracellular Ca2+ influx. The latter has been coupled to hyperactivation of the nonselective cation channel, transient receptor potential canonical channel 6 (Trpc6), in isolated myocytes. As Ca2+ also activates NOS, we hypothesized that Trpc6 would help to mediate nitric oxide (NO) dysregulation and that this would be manifest in increased myocardial S-nitrosylation, a posttranslational modification increasingly implicated in neurodegenerative, inflammatory, and muscle disease. Using a recently developed dual-labeling proteomic strategy, we identified 1,276 S-nitrosylated cysteine residues [S-nitrosothiol (SNO)] on 491 proteins in resting hearts from a mouse model of DMD (dmdmdx:utrn+/-). These largely consisted of mitochondrial proteins, metabolic regulators, and sarcomeric proteins, with 80% of them also modified in wild type (WT). S-nitrosylation levels, however, were increased in DMD. Genetic deletion of Trpc6 in this model (dmdmdx:utrn+/-:trpc6-/-) reversed ∼70% of these changes. Trpc6 deletion also ameliorated left ventricular dilation, improved cardiac function, and tended to reduce fibrosis. Furthermore, under catecholamine stimulation, which also increases NO synthesis and intracellular Ca2+ along with cardiac workload, the hypernitrosylated state remained as it did at baseline. However, the impact of Trpc6 deletion on the SNO proteome became less marked. These findings reveal a role for Trpc6-mediated hypernitrosylation in dmdmdx:utrn+/- mice and support accumulating evidence that implicates nitrosative stress in cardiac and muscle disease.
Collapse
|
19
|
Hu X, Charles JP, Akay T, Hutchinson JR, Blemker SS. Are mice good models for human neuromuscular disease? Comparing muscle excursions in walking between mice and humans. Skelet Muscle 2017; 7:26. [PMID: 29145886 PMCID: PMC5689180 DOI: 10.1186/s13395-017-0143-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 10/26/2017] [Indexed: 11/29/2022] Open
Abstract
Background The mouse is one of the most widely used animal models to study neuromuscular diseases and test new therapeutic strategies. However, findings from successful pre-clinical studies using mouse models frequently fail to translate to humans due to various factors. Differences in muscle function between the two species could be crucial but often have been overlooked. The purpose of this study was to evaluate and compare muscle excursions in walking between mice and humans. Methods Recently published musculoskeletal models of the mouse hindlimb and human lower limb were used to simulate muscle-tendon dynamics during mouse and human walking, a key daily activity. Muscle fiber length changes (fiber excursions) of 25 muscle homologs in the two species were calculated from these simulations and then compared. To understand potential causes of differences in fiber excursions in walking, joint excursions and muscle moment arms were also compared across one gait cycle. Results Most muscles (19 out of 25 muscles) of the mouse hindlimb had much smaller fiber excursions as compared to human lower limb muscles during walking. For these muscles, fiber excursions in mice were only 48 ± 19% of those in humans. The differences in fiber excursion between the two species were primarily due to the reduced joint excursions and smaller muscle moment arms in mice as compared to humans. Conclusions Since progressive neuromuscular diseases, such as Duchenne muscular dystrophy, are known to be accelerated by damage accumulated from active muscle lengthening, these results suggest that biomechanical differences in muscle function during walking between mice and humans may impede the translations of knowledge gained from mouse models to humans. This knowledge would add a fresh perspective on how pre-clinical studies on mice might be better designed to improve translation to human clinical trials. Electronic supplementary material The online version of this article (10.1186/s13395-017-0143-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Xiao Hu
- Department of Biomedical Engineering, University of Virginia, 415 Lane Road, Charlottesville, VA, 22908, USA
| | - James P Charles
- Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Turgay Akay
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - John R Hutchinson
- Comparative Biomedical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, AL9 7TA, UK
| | - Silvia S Blemker
- Department of Biomedical Engineering, University of Virginia, 415 Lane Road, Charlottesville, VA, 22908, USA. .,Department of Orthopaedic Surgery, University of Virginia, Charlottesville, VA, 22903, USA. .,Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, 22903, USA.
| |
Collapse
|
20
|
Maurício AF, de Carvalho SC, Santo Neto H, Marques MJ. Effects of dietary omega-3 on dystrophic cardiac and diaphragm muscles as evaluated by 1 H magnetic resonance spectroscopy: Metabolic profile and calcium-related proteins. Clin Nutr ESPEN 2017; 20:60-67. [DOI: 10.1016/j.clnesp.2017.03.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 03/08/2017] [Indexed: 12/22/2022]
|
21
|
Abstract
PURPOSE OF REVIEW To discuss current knowledge on the role of connexins and pannexins in the musculoskeletal system. RECENT FINDINGS Connexins and pannexins are crucial for the development and maintenance of both bone and skeletal muscle. In bone, the presence of connexin and more recently of pannexin channels in osteoblasts, osteoclasts, and osteocytes has been described and shown to be essential for normal skeletal development and bone adaptation. In skeletal muscles, connexins and pannexins play important roles during development and regeneration through coordinated regulation of metabolic functions via cell-to-cell communication. Further, under pathological conditions, altered expression of these proteins can promote muscle atrophy and degeneration by stimulating inflammasome activity. In this review, we highlight the important roles of connexins and pannexins in the development, maintenance, and regeneration of musculoskeletal tissues, with emphasis on the mechanisms by which these molecules mediate chemical (e.g., ATP and prostaglandin E2) and physical (e.g., mechanical stimulation) stimuli that target the musculoskeletal system and their involvement in the pathophysiological changes in both genetic and acquired diseases.
Collapse
Affiliation(s)
- Lilian I Plotkin
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, 635 Barnhill Drive, MS5045, Indianapolis, IN, 46202, USA.
- Roudebush Veterans Administration Medical Center, Indianapolis, Indiana, USA.
- Indiana Center for Musculoskeletal Health, Indianapolis, Indiana, USA.
| | - Hannah M Davis
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, 635 Barnhill Drive, MS5045, Indianapolis, IN, 46202, USA
| | - Bruno A Cisterna
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Av. Alameda 340, Santiago, Chile
| | - Juan C Sáez
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Av. Alameda 340, Santiago, Chile.
- Centro Interdisciplinario de Neurociencias de Valparaíso, Valparaíso, Chile.
| |
Collapse
|
22
|
Fatouros IG, Jamurtas AZ. Insights into the molecular etiology of exercise-induced inflammation: opportunities for optimizing performance. J Inflamm Res 2016; 9:175-186. [PMID: 27799809 PMCID: PMC5085309 DOI: 10.2147/jir.s114635] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The study of exercise-induced muscle damage (EIMD) is of paramount importance not only because it affects athletic performance but also because it is an excellent model to study the mechanisms governing muscle cachexia under various clinical conditions. Although, a large number of studies have investigated EIMD and its associated inflammatory response, several aspects of skeletal muscles responses remain unclear. In the first section of this article, the mechanisms of EIMD are reviewed in an attempt to follow the events that result in functional and structural alterations of skeletal muscle. In the second section, the inflammatory response associated with EIMD is presented with emphasis in leukocyte accumulation through mechanisms that are largely coordinated by pro- and anti-inflammatory cytokines released either by injured muscle itself or other cells. The practical applications of EIMD and the subsequent inflammatory response are discussed with respect to athletic performance. Specifically, the mechanisms leading to performance deterioration and development of muscle soreness are discussed. Emphasis is given to the factors affecting individual responses to EIMD and the resulting interindividual variability to this phenomenon.
Collapse
Affiliation(s)
- Ioannis G Fatouros
- School of Physical Education and Sport Sciences, University of Thessaly, Karies, Trikala, Greece
| | - Athanasios Z Jamurtas
- School of Physical Education and Sport Sciences, University of Thessaly, Karies, Trikala, Greece
| |
Collapse
|
23
|
Spinazzola JM, Kunkel LM. Pharmacological therapeutics targeting the secondary defects and downstream pathology of Duchenne muscular dystrophy. Expert Opin Orphan Drugs 2016; 4:1179-1194. [PMID: 28670506 DOI: 10.1080/21678707.2016.1240613] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Since the identification of the dystrophin gene in 1986, a cure for Duchenne muscular dystrophy (DMD) has yet to be discovered. Presently, there are a number of genetic-based therapies in development aimed at restoration and/or repair of the primary defect. However, growing understanding of the pathophysiological consequences of dystrophin absence has revealed several promising downstream targets for the development of therapeutics. AREAS COVERED In this review, we discuss various strategies for DMD therapy targeting downstream consequences of dystrophin absence including loss of muscle mass, inflammation, fibrosis, calcium overload, oxidative stress, and ischemia. The rationale of each approach and the efficacy of drugs in preclinical and clinical studies are discussed. EXPERT OPINION For the last 30 years, effective DMD drug therapy has been limited to corticosteroids, which are associated with a number of negative side effects. Our knowledge of the consequences of dystrophin absence that contribute to DMD pathology has revealed several potential therapeutic targets. Some of these approaches may have potential to improve or slow disease progression independently or in combination with genetic-based approaches. The applicability of these pharmacological therapies to DMD patients irrespective of their genetic mutation, as well as the potential benefits even for advanced stage patients warrants their continued investigation.
Collapse
Affiliation(s)
- Janelle M Spinazzola
- Boston Children's Hospital, Division of Genetics and Genomics, Boston, MA 02115.,Harvard Medical School, Departments of Pediatrics and Genetics, Boston, MA 02115
| | - Louis M Kunkel
- Boston Children's Hospital, Division of Genetics and Genomics, Boston, MA 02115.,Harvard Medical School, Departments of Pediatrics and Genetics, Boston, MA 02115.,The Stem Cell Program at Boston Children's Hospital, Boston, MA 02115.,The Manton Center for Orphan Diseases, Boston, MA 02115.,Harvard Stem Cell Institute, Cambridge, MA 02138
| |
Collapse
|
24
|
Role of dystroglycan in limiting contraction-induced injury to the sarcomeric cytoskeleton of mature skeletal muscle. Proc Natl Acad Sci U S A 2016; 113:10992-7. [PMID: 27625424 DOI: 10.1073/pnas.1605265113] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Dystroglycan (DG) is a highly expressed extracellular matrix receptor that is linked to the cytoskeleton in skeletal muscle. DG is critical for the function of skeletal muscle, and muscle with primary defects in the expression and/or function of DG throughout development has many pathological features and a severe muscular dystrophy phenotype. In addition, reduction in DG at the sarcolemma is a common feature in muscle biopsies from patients with various types of muscular dystrophy. However, the consequence of disrupting DG in mature muscle is not known. Here, we investigated muscles of transgenic mice several months after genetic knockdown of DG at maturity. In our study, an increase in susceptibility to contraction-induced injury was the first pathological feature observed after the levels of DG at the sarcolemma were reduced. The contraction-induced injury was not accompanied by increased necrosis, excitation-contraction uncoupling, or fragility of the sarcolemma. Rather, disruption of the sarcomeric cytoskeleton was evident as reduced passive tension and decreased titin immunostaining. These results reveal a role for DG in maintaining the stability of the sarcomeric cytoskeleton during contraction and provide mechanistic insight into the cause of the reduction in strength that occurs in muscular dystrophy after lengthening contractions.
Collapse
|
25
|
Whitehead NP, Kim MJ, Bible KL, Adams ME, Froehner SC. Simvastatin offers new prospects for the treatment of Duchenne muscular dystrophy. Rare Dis 2016; 4:e1156286. [PMID: 27141415 PMCID: PMC4838314 DOI: 10.1080/21675511.2016.1156286] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 02/12/2016] [Indexed: 12/28/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is the most common and severe inherited neuromuscular disorder. DMD is caused by mutations in the gene encoding the dystrophin protein in muscle fibers. Dystrophin was originally proposed to be a structural protein that protected the sarcolemma from stresses produced during contractions. However, more recently, experimental evidence has revealed a far more complicated picture, with the loss of dystrophin causing dysfunction of multiple muscle signaling pathways, which all contribute to the overall disease pathophysiology. Current gene-based approaches for DMD are conceptually appealing since they offer the potential to restore dystrophin to muscles, albeit a partially functional, truncated form of the protein. However, given the cost and technical challenges facing these genetic approaches, it is important to consider if relatively inexpensive, clinically used drugs may be repurposed for treating DMD. Here, we discuss our recent findings showing the potential of simvastatin as a novel therapy for DMD.
Collapse
Affiliation(s)
- Nicholas P Whitehead
- Department of Physiology and Biophysics, University of Washington , Seattle, WA, USA
| | - Min Jeong Kim
- Department of Physiology and Biophysics, University of Washington , Seattle, WA, USA
| | - Kenneth L Bible
- Department of Physiology and Biophysics, University of Washington , Seattle, WA, USA
| | - Marvin E Adams
- Department of Physiology and Biophysics, University of Washington , Seattle, WA, USA
| | - Stanley C Froehner
- Department of Physiology and Biophysics, University of Washington , Seattle, WA, USA
| |
Collapse
|
26
|
Allen DG, Whitehead NP, Froehner SC. Absence of Dystrophin Disrupts Skeletal Muscle Signaling: Roles of Ca2+, Reactive Oxygen Species, and Nitric Oxide in the Development of Muscular Dystrophy. Physiol Rev 2016; 96:253-305. [PMID: 26676145 DOI: 10.1152/physrev.00007.2015] [Citation(s) in RCA: 272] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Dystrophin is a long rod-shaped protein that connects the subsarcolemmal cytoskeleton to a complex of proteins in the surface membrane (dystrophin protein complex, DPC), with further connections via laminin to other extracellular matrix proteins. Initially considered a structural complex that protected the sarcolemma from mechanical damage, the DPC is now known to serve as a scaffold for numerous signaling proteins. Absence or reduced expression of dystrophin or many of the DPC components cause the muscular dystrophies, a group of inherited diseases in which repeated bouts of muscle damage lead to atrophy and fibrosis, and eventually muscle degeneration. The normal function of dystrophin is poorly defined. In its absence a complex series of changes occur with multiple muscle proteins showing reduced or increased expression or being modified in various ways. In this review, we will consider the various proteins whose expression and function is changed in muscular dystrophies, focusing on Ca(2+)-permeable channels, nitric oxide synthase, NADPH oxidase, and caveolins. Excessive Ca(2+) entry, increased membrane permeability, disordered caveolar function, and increased levels of reactive oxygen species are early changes in the disease, and the hypotheses for these phenomena will be critically considered. The aim of the review is to define the early damage pathways in muscular dystrophy which might be appropriate targets for therapy designed to minimize the muscle degeneration and slow the progression of the disease.
Collapse
Affiliation(s)
- David G Allen
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Nicholas P Whitehead
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Stanley C Froehner
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| |
Collapse
|
27
|
Aguettaz E, Lopez JJ, Krzesiak A, Lipskaia L, Adnot S, Hajjar RJ, Cognard C, Constantin B, Sebille S. Axial stretch-dependent cation entry in dystrophic cardiomyopathy: Involvement of several TRPs channels. Cell Calcium 2016; 59:145-155. [PMID: 26803937 DOI: 10.1016/j.ceca.2016.01.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 12/14/2015] [Accepted: 01/02/2016] [Indexed: 02/07/2023]
Abstract
In Duchenne muscular dystrophy (DMD), deficiency of the cytoskeletal protein dystrophin leads to well-described defects in skeletal muscle but also to dilated cardiomyopathy (DCM). In cardiac cells, the subsarcolemmal localization of dystrophin is thought to protect the membrane from mechanical stress. The dystrophin deficiency leads to membrane instability and a high stress-induced Ca(2+) influx due to dysregulation of sarcolemmal channels such as stretch-activated channels (SACs). In this work divalent cation entry has been explored in isolated ventricular Wild Type (WT) and mdx cardiomyocytes in two different conditions: at rest and during the application of an axial stretch. At rest, our results suggest that activation of TRPV2 channels participates to a constitutive basal cation entry in mdx cardiomyocytes.Using microcarbon fibres technique, an axial stretchwas applied to mimic effects of physiological conditions of ventricular filling and study on cation influx bythe Mn(2+)-quenching techniquedemonstrated a high stretch-dependentcationic influx in dystrophic cells, partially due to SACs. Involvement of TRPs channels in this excessive Ca(2+) influx has been investigated using specific modulators and demonstratedboth sarcolemmal localization and an abnormal activity of TRPV2 channels. In conclusion, TRPV2 channels are demonstrated here to play a key role in cation influx and dysregulation in dystrophin deficient cardiomyocytes, enhanced in stretching conditions.
Collapse
Affiliation(s)
- E Aguettaz
- Laboratoire de Signalisation et Transports Ioniques Membranaires (STIM CNRS ERL 7368), Equipe Transferts Ioniques et Rythmicité Cardiaque (TIRC), Université de Poitiers, 86073 Poitiers Cedex 9, France
| | - J J Lopez
- Laboratoire de Signalisation et Transports Ioniques Membranaires (STIM CNRS ERL 7368), Equipe Calcium et Microenvironnement des Cellules Souches (CMCS), Université de Poitiers, 86073 Poitiers Cedex 9, France
| | - A Krzesiak
- Laboratoire de Signalisation et Transports Ioniques Membranaires (STIM CNRS ERL 7368), Equipe Transferts Ioniques et Rythmicité Cardiaque (TIRC), Université de Poitiers, 86073 Poitiers Cedex 9, France
| | - L Lipskaia
- INSERM U955 and Département de Physiologie, Hôpital Henri Mondor, AP-HP, Université Paris-Est Créteil (UPEC), 94010 Créteil, France.,Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - S Adnot
- INSERM U955 and Département de Physiologie, Hôpital Henri Mondor, AP-HP, Université Paris-Est Créteil (UPEC), 94010 Créteil, France
| | - R J Hajjar
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - C Cognard
- Laboratoire de Signalisation et Transports Ioniques Membranaires (STIM CNRS ERL 7368), Equipe Transferts Ioniques et Rythmicité Cardiaque (TIRC), Université de Poitiers, 86073 Poitiers Cedex 9, France
| | - B Constantin
- Laboratoire de Signalisation et Transports Ioniques Membranaires (STIM CNRS ERL 7368), Equipe Calcium et Microenvironnement des Cellules Souches (CMCS), Université de Poitiers, 86073 Poitiers Cedex 9, France
| | - S Sebille
- Laboratoire de Signalisation et Transports Ioniques Membranaires (STIM CNRS ERL 7368), Equipe Transferts Ioniques et Rythmicité Cardiaque (TIRC), Université de Poitiers, 86073 Poitiers Cedex 9, France
| |
Collapse
|
28
|
Hyzewicz J, Ruegg UT, Takeda S. Comparison of Experimental Protocols of Physical Exercise for mdx Mice and Duchenne Muscular Dystrophy Patients. J Neuromuscul Dis 2015; 2:325-342. [PMID: 27858750 PMCID: PMC5240598 DOI: 10.3233/jnd-150106] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Duchenne Muscular Dystrophy (DMD) is caused by mutations in the gene coding for dystrophin and leads to muscle degeneration, wheelchair dependence and death by cardiac or respiratory failure. Physical exercise has been proposed as a palliative therapy for DMD to maintain muscle strength and prevent contractures for as long as possible. However, its practice remains controversial because the benefits of training may be counteracted by muscle overuse and damage. The effects of physical exercise have been investigated in muscles of dystrophin-deficient mdx mice and in patients with DMD. However, a lack of uniformity among protocols limits comparability between studies and translatability of results from animals to humans. In the present review, we summarize and discuss published protocols used to investigate the effects of physical exercise on mdx mice and DMD patients, with the objectives of improving comparability between studies and identifying future research directions.
Collapse
Affiliation(s)
- Janek Hyzewicz
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | | | - Shin'ichi Takeda
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| |
Collapse
|
29
|
Sachs F. Mechanical transduction by ion channels: A cautionary tale. World J Neurol 2015; 5:74-87. [PMID: 28078202 PMCID: PMC5221657 DOI: 10.5316/wjn.v5.i3.74] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 08/23/2014] [Accepted: 07/17/2015] [Indexed: 02/06/2023] Open
Abstract
Mechanical transduction by ion channels occurs in all cells. The physiological functions of these channels have just begun to be elaborated, but if we focus on the upper animal kingdom, these channels serve the common sensory services such as hearing and touch, provide the central nervous system with information on the force and position of muscles and joints, and they provide the autonomic system with information about the filling of hollow organs such as blood vessels. However, all cells of the body have mechanosensitive channels (MSCs), including red cells. Most of these channels are cation selective and are activated by bilayer tension. There are also K+ selective MSCs found commonly in neurons where they may be responsible for both general anesthesia and knockout punches in the boxing ring by hyperpolarizing neurons to reduce excitability. The cationic MSCs are typically inactive under normal mechanical stress, but open under pathologic stress. The channels are normally inactive because they are shielded from stress by the cytoskeleton. The cationic MSCs are specifically blocked by the externally applied peptide GsMtx4 (aka, AT-300). This is the first drug of its class and provides a new approach to many pathologies since it is nontoxic, non-immunogenic, stable in a biological environment and has a long pharmacokinetic lifetime. Pathologies involving excessive stress are common. They produce cardiac arrhythmias, contraction in stretched dystrophic muscle, xerocytotic and sickled red cells, etc. The channels seem to function primarily as “fire alarms”, providing feedback to the cytoskeleton that a region of the bilayer is under excessive tension and needs reinforcing. The eukaryotic forms of MSCs have only been cloned in recent years and few people have experience working with them. “Newbies” need to become aware of the technology, potential artifacts, and the fundamentals of mechanics. The most difficult problem in studying MSCs is that the actual stimulus, the force applied to the channel, is not known. We don’t have direct access to the channels themselves but only to larger regions of the membrane as seen in patches. Cortical forces are shared by the bilayer, the cytoskeleton and the extracellular matrix. How much of an applied stimulus reaches the channel is unknown. Furthermore, many of these channels exist in spatial domains where the forces within a domain are different from forces outside the domain, although we often hope they are proportional. This review is intended to be a guide for new investigators who want to study mechanosensitive ion channels.
Collapse
|
30
|
Burr AR, Molkentin JD. Genetic evidence in the mouse solidifies the calcium hypothesis of myofiber death in muscular dystrophy. Cell Death Differ 2015; 22:1402-12. [PMID: 26088163 PMCID: PMC4532779 DOI: 10.1038/cdd.2015.65] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 04/03/2015] [Accepted: 04/17/2015] [Indexed: 01/19/2023] Open
Abstract
Muscular dystrophy (MD) refers to a clinically and genetically heterogeneous group of degenerative muscle disorders characterized by progressive muscle wasting and often premature death. Although the primary defect underlying most forms of MD typically results from a loss of sarcolemmal integrity, the secondary molecular mechanisms leading to muscle degeneration and myofiber necrosis is debated. One hypothesis suggests that elevated or dysregulated cytosolic calcium is the common transducing event, resulting in myofiber necrosis in MD. Previous measurements of resting calcium levels in myofibers from dystrophic animal models or humans produced equivocal results. However, recent studies in genetically altered mouse models have largely solidified the calcium hypothesis of MD, such that models with artificially elevated calcium in skeletal muscle manifest fulminant dystrophic-like disease, whereas models with enhanced calcium clearance or inhibited calcium influx are resistant to myofiber death and MD. Here, we will review the field and the recent cadre of data from genetically altered mouse models, which we propose have collectively mostly proven the hypothesis that calcium is the primary effector of myofiber necrosis in MD. This new consensus on calcium should guide future selection of drugs to be evaluated in clinical trials as well as gene therapy-based approaches.
Collapse
Affiliation(s)
- A R Burr
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, 240 Albert Sabin Way, Cincinnati, OH, USA
| | - J D Molkentin
- 1] Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, 240 Albert Sabin Way, Cincinnati, OH, USA [2] Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Howard Hughes Medical Institute, Molecular Cardiovascular Biology, 240 Albert Sabin Way, Cincinnati, OH, USA
| |
Collapse
|
31
|
Mázala DAG, Pratt SJP, Chen D, Molkentin JD, Lovering RM, Chin ER. SERCA1 overexpression minimizes skeletal muscle damage in dystrophic mouse models. Am J Physiol Cell Physiol 2015; 308:C699-709. [PMID: 25652448 DOI: 10.1152/ajpcell.00341.2014] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 02/01/2015] [Indexed: 02/04/2023]
Abstract
Duchenne muscular dystrophy (DMD) is characterized by progressive muscle wasting secondary to repeated muscle damage and inadequate repair. Elevations in intracellular free Ca²⁺ have been implicated in disease progression, and sarcoplasmic/endoplasmic reticulum Ca²⁺-ATPase 1 (SERCA1) overexpression has been shown to ameliorate the dystrophic phenotype in mdx mice. The purpose of this study was to assess the effects of SERCA1 overexpression in the more severe mdx/Utr(-/-) mouse model of DMD. Mice overexpressing SERCA1 were crossed with mdx/Utr ± mice to generate mdx/Utr(-/-)/+SERCA1 mice and compared with wild-type (WT), WT/+SERCA1, mdx/+SERCA1, and genotype controls. Mice were assessed at ∼12 wk of age for changes in Ca²⁺ handling, muscle mass, quadriceps torque, markers of muscle damage, and response to repeated eccentric contractions. SERCA1-overexpressing mice had a two- to threefold increase in maximal sarcoplasmic reticulum Ca²⁺-ATPase activity compared with WT which was associated with normalization in body mass for both mdx/+SERCA1 and mdx/Utr(-/-)/+SERCA1. Torque deficit in the quadriceps after eccentric injury was 2.7-fold greater in mdx/Utr(-/-) vs. WT mice, but only 1.5-fold greater in mdx/Utr(-/-)/+SERCA1 vs. WT mice, an attenuation of 44%. Markers of muscle damage (% centrally nucleated fibers, necrotic area, and serum creatine kinase levels) were higher in both mdx and mdx/Utr(-/-) vs. WT, and all were attenuated by overexpression of SERCA1. These data indicate that SERCA1 overexpression ameliorates functional impairments and cellular markers of damage in a more severe mouse model of DMD. These findings support targeting intracellular Ca²⁺ control as a therapeutic approach for DMD.
Collapse
Affiliation(s)
- Davi A G Mázala
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryand
| | - Stephen J P Pratt
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryand; and
| | - Dapeng Chen
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryand
| | - Jeffery D Molkentin
- Department of Pediatrics, University of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Richard M Lovering
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryand; and
| | - Eva R Chin
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryand; Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryand; and Department of Pediatrics, University of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| |
Collapse
|
32
|
Michielin F, Serena E, Pavan P, Elvassore N. Microfluidic-assisted cyclic mechanical stimulation affects cellular membrane integrity in a human muscular dystrophy in vitro model. RSC Adv 2015. [DOI: 10.1039/c5ra16957g] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The development of a microfluidic-based cell stretching device allows to investigate membrane permeability during cyclic mechanical stimulation in a human Duchenne Muscular Dystrophy skeletal musclein vitromodel.
Collapse
Affiliation(s)
- F. Michielin
- Department of Industrial Engineering (DII)
- University of Padova
- 35131 Padova
- Italy
- Venetian Institute of Molecular Medicine (VIMM)
| | - E. Serena
- Department of Industrial Engineering (DII)
- University of Padova
- 35131 Padova
- Italy
- Venetian Institute of Molecular Medicine (VIMM)
| | - P. Pavan
- Department of Industrial Engineering (DII)
- University of Padova
- 35131 Padova
- Italy
- Centre for Mechanics of Biological Materials (CMBM)
| | - N. Elvassore
- Department of Industrial Engineering (DII)
- University of Padova
- 35131 Padova
- Italy
- Venetian Institute of Molecular Medicine (VIMM)
| |
Collapse
|
33
|
Abstract
Muscle cells have an elaborate plasma membrane and t-tubule system that has been evolutionarily refined to maximize electrical conductivity for synchronous muscle contraction. However, this elaborate plasma membrane network has intrinsic vulnerabilities to stretch-induced membrane injury, and thus requires ongoing maintenance and repair. Herein we discuss the types of membrane injuries encountered by myofibers in healthy muscle and in muscular dystrophy. We review the different mechanisms by which muscle fibers in patients with muscular dystrophy are rendered more susceptible to injury, and we summarize the latest developments in our understanding of how the muscular dystrophy protein dysferlin mediates satellite-cell independent membrane repair.
Collapse
Affiliation(s)
- Sandra T Cooper
- Institute for Neuroscience and Muscle Research, Kids Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales, Australia Discipline of Paediatrics and Child Health, Faculty of Medicine, University of Sydney, New South Wales, Australia
| | - Stewart I Head
- School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| |
Collapse
|
34
|
Ismail HM, Dorchies OM, Perozzo R, Strosova MK, Scapozza L, Ruegg UT. Inhibition of iPLA2 β and of stretch-activated channels by doxorubicin alters dystrophic muscle function. Br J Pharmacol 2014; 169:1537-50. [PMID: 23849042 DOI: 10.1111/bph.12188] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 02/28/2013] [Accepted: 03/15/2013] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Chronic elevation in intracellular Ca(2+) concentration participates in death of skeletal muscle from mdx mice, a model for Duchenne muscular dystrophy (DMD). Candidate pathways mediating this Ca(2+) overload involve store-operated channels (SOCs) and stretch-activated channels (SACs), which are modulated by the Ca(2+) -independent form of PL A2 (iPLA2 ). We investigated the effect of doxorubicin (Dox), a chemotherapeutic agent reported to inhibit iPLA2 in other systems, on the activity of this enzyme and on the consequences on Ca(2+) handling and muscle function in mdx mice. EXPERIMENTAL APPROACH Effects of Dox on iPLA2 activity, reactive oxygen species production and on Ca(2+) influx were investigated in C2C12 and mdx myotubes. The mechanism of Dox-mediated iPLA2 inhibition was evaluated using purified 6x histidine-tagged enzyme. Aequorin technology was used to assess Ca(2+) concentrations underneath the plasma membrane. Isolated muscles were exposed to fatigue protocols and eccentric contractions to evaluate the effects of Dox on muscle function. KEY RESULTS Dox at 1-30 μM inhibited iPLA2 activity in cells and in the purified enzyme. Dox also inhibited SAC- but not SOC-mediated Ca(2+) influx in myotubes. Stimulated elevations of Ca(2+) concentrations below the plasmalemma were also blocked. Exposure of excised muscle to Dox was not deleterious to force production and promoted recovery from eccentric contractions. CONCLUSIONS AND IMPLICATIONS Dox showed efficacy against targets known to play a role in the pathology of DMD, namely iPLA2 and SAC. The potent SAC inhibitory effect of Dox is a novel finding that can explain partly the cardiomyopathy seen in chronic anthracycline treatment.
Collapse
Affiliation(s)
- H M Ismail
- Pharmacology, Geneva-Lausanne School of Pharmaceutical Sciences, University of Geneva and University of Lausanne, Geneva, Switzerland
| | | | | | | | | | | |
Collapse
|
35
|
Diapocynin, a dimer of the NADPH oxidase inhibitor apocynin, reduces ROS production and prevents force loss in eccentrically contracting dystrophic muscle. PLoS One 2014; 9:e110708. [PMID: 25329652 PMCID: PMC4201587 DOI: 10.1371/journal.pone.0110708] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 09/24/2014] [Indexed: 11/19/2022] Open
Abstract
Elevation of intracellular Ca2+, excessive ROS production and increased phospholipase A2 activity contribute to the pathology in dystrophin-deficient muscle. Moreover, Ca2+, ROS and phospholipase A2, in particular iPLA2, are thought to potentiate each other in positive feedback loops. NADPH oxidases (NOX) have been considered as a major source of ROS in muscle and have been reported to be overexpressed in muscles of mdx mice. We report here on our investigations regarding the effect of diapocynin, a dimer of the commonly used NOX inhibitor apocynin, on the activity of iPLA2, Ca2+ handling and ROS generation in dystrophic myotubes. We also examined the effects of diapocynin on force production and recovery ability of isolated EDL muscles exposed to eccentric contractions in vitro, a damaging procedure to which dystrophic muscle is extremely sensitive. In dystrophic myotubes, diapocynin inhibited ROS production, abolished iPLA2 activity and reduced Ca2+ influx through stretch-activated and store-operated channels, two major pathways responsible for excessive Ca2+ entry in dystrophic muscle. Diapocynin also prevented force loss induced by eccentric contractions of mdx muscle close to the value of wild-type muscle and reduced membrane damage as seen by Procion orange dye uptake. These findings support the central role played by NOX-ROS in the pathogenic cascade leading to muscular dystrophy and suggest diapocynin as an effective NOX inhibitor that might be helpful for future therapeutic approaches.
Collapse
|
36
|
ROS and RNS signaling in skeletal muscle: critical signals and therapeutic targets. ANNUAL REVIEW OF NURSING RESEARCH 2014; 31:367-87. [PMID: 24894146 DOI: 10.1891/0739-6686.31.367] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The health of skeletal muscle is promoted by optimal nutrition and activity/exercise through the activation of molecular signaling pathways. Reactive oxygen species (ROS) or reactive nitrogen species (RNS) have been shown to modulate numerous biochemical processes including glucose uptake, gene expression, calcium signaling, and contractility. In pathological conditions, ROS/RNS signaling excess or dysfunction contributes to contractile dysfunction and myopathy in skeletal muscle. Here we provide a brief review of ROS/RNS chemistry and discuss concepts of ROS/RNS signaling and its role in physiological and pathophysiological processes within striated muscle.
Collapse
|
37
|
Tan N, Lansman JB. Utrophin regulates modal gating of mechanosensitive ion channels in dystrophic skeletal muscle. J Physiol 2014; 592:3303-23. [PMID: 24879867 DOI: 10.1113/jphysiol.2014.274332] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Dystrophin is a large, submembrane cytoskeletal protein, absence of which causes Duchenne muscular dystrophy. Utrophin is a dystrophin homologue found in both muscle and brain whose physiological function is unknown. Recordings of single-channel activity were made from membrane patches on skeletal muscle from mdx, mdx/utrn(+/-) heterozygotes and mdx/utrn(-/-) double knockout mice to investigate the role of these cytoskeletal proteins in mechanosensitive (MS) channel gating. We find complex, gene dose-dependent effects of utrophin depletion in dystrophin-deficient mdx muscle: (1) increased MS channel open probability, (2) a shift of MS channel gating to larger pressures, (3) appearance of modal gating of MS channels and small conductance channels and (4) expression of large conductance MS channels. We suggest a physical model in which utrophin acts as a scaffolding protein that stabilizes lipid microdomains and clusters MS channel subunits. Depletion of utrophin disrupts domain composition in a manner that favours open channel area expansion, as well as allowing diffusion and aggregation of additional MS channel subunits.
Collapse
Affiliation(s)
- Nhi Tan
- Department of Cellular and Molecular Pharmacology, School of Medicine, University of California, San Francisco, San Francisco, CA, 94143-0450, USA
| | - Jeffry B Lansman
- Department of Cellular and Molecular Pharmacology, School of Medicine, University of California, San Francisco, San Francisco, CA, 94143-0450, USA
| |
Collapse
|
38
|
Yokota T, Miyagoe-Suzuki Y, Ikemoto T, Matsuda R, Takeda S. α1-Syntrophin-deficient mice exhibit impaired muscle force recovery after osmotic shock. Muscle Nerve 2014; 49:728-35. [DOI: 10.1002/mus.23990] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Revised: 07/29/2013] [Accepted: 08/05/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Toshifumi Yokota
- Department of Medical Genetics, School of Human Development, Faculty of Medicine and Dentistry; University of Alberta; Edmonton Alberta Canada
- Department of Molecular Therapy; National Institute of Neuroscience; National Center of Neurology and Psychiatry, 4-1-1, Ogawa-higashi, Kodaira Tokyo 187-8502 Japan
| | - Yuko Miyagoe-Suzuki
- Department of Molecular Therapy; National Institute of Neuroscience; National Center of Neurology and Psychiatry, 4-1-1, Ogawa-higashi, Kodaira Tokyo 187-8502 Japan
| | - Takaaki Ikemoto
- Department of Molecular Therapy; National Institute of Neuroscience; National Center of Neurology and Psychiatry, 4-1-1, Ogawa-higashi, Kodaira Tokyo 187-8502 Japan
| | - Ryoichi Matsuda
- Department of Life Sciences, Graduate School of Arts and Sciences; University of Tokyo; Tokyo Japan
| | - Shin'ichi Takeda
- Department of Molecular Therapy; National Institute of Neuroscience; National Center of Neurology and Psychiatry, 4-1-1, Ogawa-higashi, Kodaira Tokyo 187-8502 Japan
| |
Collapse
|
39
|
Crocetti S, Beyer C, Unternährer S, Benavides Damm T, Schade-Kampmann G, Hebeisen M, Di Berardino M, Fröhlich J, Franco-Obregón A. Impedance flow cytometry gauges proliferative capacity by detecting TRPC1 expression. Cytometry A 2014; 85:525-36. [DOI: 10.1002/cyto.a.22461] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 12/10/2013] [Accepted: 03/03/2014] [Indexed: 01/13/2023]
Affiliation(s)
| | - Christian Beyer
- Electromagnetics in Medicine and Biology Group, Laboratory for Electromagnetic Fields and Microwave Electronics; ETH Zürich Switzerland
| | | | - Tatiana Benavides Damm
- Institute for Biomechanics; ETH Zürich Switzerland
- CC Aerospace Biomedical Science & Technology, Space Biology Group, Luzern University of Applied Sciences and Arts; Hergiswil Switzerland
| | | | - Monika Hebeisen
- Leister Process Technologies; Axetris Division; Kaegiswil Switzerland
| | | | - Jürg Fröhlich
- Electromagnetics in Medicine and Biology Group, Laboratory for Electromagnetic Fields and Microwave Electronics; ETH Zürich Switzerland
| | - Alfredo Franco-Obregón
- Institute for Biomechanics; ETH Zürich Switzerland
- Department of Surgery; Yong Loo Lin School of Medicine, National University of Singapore; Singapore
| |
Collapse
|
40
|
Goonasekera SA, Davis J, Kwong JQ, Accornero F, Wei-LaPierre L, Sargent MA, Dirksen RT, Molkentin JD. Enhanced Ca²⁺ influx from STIM1-Orai1 induces muscle pathology in mouse models of muscular dystrophy. Hum Mol Genet 2014; 23:3706-15. [PMID: 24556214 DOI: 10.1093/hmg/ddu079] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Muscular dystrophy is a progressive muscle wasting disease that is thought to be initiated by unregulated Ca(2+) influx into myofibers leading to their death. Store-operated Ca(2+) entry (SOCE) through sarcolemmal Ca(2+) selective Orai1 channels in complex with STIM1 in the sarcoplasmic reticulum is one such potential disease mechanism for pathologic Ca(2+) entry. Here, we generated a mouse model of STIM1 overexpression in skeletal muscle to determine whether this type of Ca(2+) entry could induce muscular dystrophy. Myofibers from muscle-specific STIM1 transgenic mice showed a significant increase in SOCE in skeletal muscle, modeling an observed increase in the same current in dystrophic myofibers. Histological and biochemical analysis of STIM1 transgenic mice showed fulminant muscle disease characterized by myofiber necrosis, swollen mitochondria, infiltration of inflammatory cells, enhanced interstitial fibrosis and elevated serum creatine kinase levels. This dystrophic-like disease in STIM1 transgenic mice was abrogated by crossing in a transgene expressing a dominant-negative Orai1 (dnOrai1) mutant. The dnOrai1 transgene also significantly reduced the severity of muscular dystrophy in both mdx (dystrophin mutant mice) and δ-sarcoglycan-deficient (Sgcd(-/-)) mouse models of disease. Hence, Ca(2+) influx across an unstable sarcolemma due to increased activity of a STIM1-Orai1 complex is a disease determinant in muscular dystrophy, and hence, SOCE represents a potential therapeutic target.
Collapse
Affiliation(s)
| | | | | | | | - Lan Wei-LaPierre
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA
| | | | - Robert T Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA
| | - Jeffery D Molkentin
- Department of Pediatrics, University of Cincinnati and Howard Hughes Medical Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA and
| |
Collapse
|
41
|
Ward CW, Prosser BL, Lederer WJ. Mechanical stretch-induced activation of ROS/RNS signaling in striated muscle. Antioxid Redox Signal 2014; 20:929-36. [PMID: 23971496 PMCID: PMC3924793 DOI: 10.1089/ars.2013.5517] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
SIGNIFICANCE Mechanical activation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) occurs in striated muscle and affects Ca(2+) signaling and contractile function. ROS/RNS signaling is tightly controlled, spatially compartmentalized, and source specific. RECENT ADVANCES Here, we review the evidence that within the contracting myocyte, the trans-membrane protein NADPH oxidase 2 (Nox2) is the primary source of ROS generated during contraction. We also review a newly characterized signaling cascade in cardiac and skeletal muscle in which the microtubule network acts as a mechanotransduction element that activates Nox2-dependent ROS generation during mechanical stretch, a pathway termed X-ROS signaling. CRITICAL ISSUES In the heart, X-ROS acts locally and affects the sarcoplasmic reticulum (SR) Ca(2+) release channels (ryanodine receptors) and tunes Ca(2+) signaling during physiological behavior, but excessive X-ROS can promote Ca(2+)-dependent arrhythmias in pathology. In skeletal muscle, X-ROS sensitizes Ca(2+)-permeable sarcolemmal "transient receptor potential" channels, a pathway that is critical for sustaining SR load during repetitive contractions, but when in excess, it is maladaptive in diseases such as Duchenne Musclar dystrophy. FUTURE DIRECTIONS New advances in ROS/RNS detection as well as molecular manipulation of signaling pathways will provide critical new mechanistic insights into the details of X-ROS signaling. These efforts will undoubtedly reveal new avenues for therapeutic intervention in the numerous diseases of striated muscle in which altered mechanoactivation of ROS/RNS production has been identified.
Collapse
|
42
|
Seo K, Rainer PP, Lee DI, Hao S, Bedja D, Birnbaumer L, Cingolani OH, Kass DA. Hyperactive adverse mechanical stress responses in dystrophic heart are coupled to transient receptor potential canonical 6 and blocked by cGMP-protein kinase G modulation. Circ Res 2014; 114:823-32. [PMID: 24449818 DOI: 10.1161/circresaha.114.302614] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
RATIONALE The heart is exquisitely sensitive to mechanical stimuli to adapt rapidly to physiological demands. In muscle lacking dystrophin, such as Duchenne muscular dystrophy, increased load during contraction triggers pathological responses thought to worsen the disease. The relevant mechanotransducers and therapies to target them remain unclear. OBJECTIVES We tested the role of transient receptor potential canonical (TRPC) channels TRPC3 and TRPC6 and their modulation by protein kinase G (PKG) in controlling cardiac systolic mechanosensing and determined their pathophysiological relevance in an experimental model of Duchenne muscular dystrophy. METHODS AND RESULTS Contracting isolated papillary muscles and cardiomyocytes from controls and mice genetically lacking either TRPC3 or TRPC6 were subjected to auxotonic load to induce stress-stimulated contractility (SSC, gradual rise in force and intracellular Ca(2+)). Incubation with cGMP (PKG activator) markedly blunted SSC in controls and Trpc3(-/-); whereas in Trpc6(-/-), the resting SSC response was diminished and cGMP had no effect. In Duchenne muscular dystrophy myocytes (mdx/utrophin deficient), the SSC was excessive and arrhythmogenic. Gene deletion or selective drug blockade of TRPC6 or cGMP/PKG activation reversed this phenotype. Chronic phosphodiesterase 5A inhibition also normalized abnormal mechanosensing while blunting progressive chamber hypertrophy in Duchenne muscular dystrophy mice. CONCLUSIONS PKG is a potent negative modulator of cardiac systolic mechanosignaling that requires TRPC6 as the target effector. In dystrophic hearts, excess SSC and arrhythmia are coupled to TRPC6 and are ameliorated by its targeted suppression or PKG activation. These results highlight novel therapeutic targets for this disease.
Collapse
Affiliation(s)
- Kinya Seo
- From the Division of Cardiology, Department of Medicine (K.S., P.P.R., D.-i.L., S.H., D.B., O.H.C., D.A.K.) and Department of Biomedical Engineering (D.A.K.), The Johns Hopkins Medical Institutions, Baltimore, MD; Division of Cardiology, Medical University of Graz, Graz, Austria (P.P.R.); and National Institute of Environmental Health Science, Research Triangle Park, NC (L.B.)
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Barnabei MS, Martindale JM, Townsend D, Metzger JM. Exercise and muscular dystrophy: implications and analysis of effects on musculoskeletal and cardiovascular systems. Compr Physiol 2013; 1:1353-63. [PMID: 23733645 DOI: 10.1002/cphy.c100062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The muscular dystrophies are a heterogeneous collection of progressive, inherited diseases of muscle weakness and degeneration. Although these diseases can vary widely in their etiology and presentation, nearly all muscular dystrophies cause exercise intolerance to some degree. Here, we focus on Duchenne muscular dystrophy (DMD), the most common form of muscular dystrophy, as a paradigm for the effects of muscle disease on exercise capacity. First described in the mid-1800s, DMD is a rapidly progressive and lethal muscular dystrophy caused by mutations in the dystrophin gene. Dystrophin is a membrane-associated cytoskeletal protein, the loss of which causes numerous cellular defects including mechanical instability of the sarcolemma, increased influx of extracellular calcium, and cell signaling defects. Here, we discuss the physiological basis for exercise intolerance in DMD, focusing on the molecular and cellular defects caused by loss of dystrophin and how these manifest as organ-level dysfunction and reduced exercise capacity. The main focus of this article is the defects present in dystrophin-deficient striated muscle. However, discussion regarding the effects of dystrophin loss on other tissues, including vascular smooth muscle is also included. Collectively, the goal of this article is to summarize the current state of knowledge regarding the mechanistic basis for exercise intolerance in DMD, which may serve as an archetype for other muscular dystrophies and diseases of muscle wasting.
Collapse
Affiliation(s)
- Matthew S Barnabei
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | | | | | | |
Collapse
|
44
|
Hyldahl RD, Hubal MJ. Lengthening our perspective: Morphological, cellular, and molecular responses to eccentric exercise. Muscle Nerve 2013; 49:155-70. [DOI: 10.1002/mus.24077] [Citation(s) in RCA: 180] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 08/23/2013] [Accepted: 08/26/2013] [Indexed: 12/25/2022]
Affiliation(s)
- Robert D. Hyldahl
- Department of Exercise Science; 106 Smith Fieldhouse; Brigham Young University; Provo Utah 84003 USA
| | - Monica J. Hubal
- Research Center for Genetic Medicine; Children's National Medical Center; Washington DC USA
| |
Collapse
|
45
|
Vinsant S, Mansfield C, Jimenez-Moreno R, Del Gaizo Moore V, Yoshikawa M, Hampton TG, Prevette D, Caress J, Oppenheim RW, Milligan C. Characterization of early pathogenesis in the SOD1(G93A) mouse model of ALS: part I, background and methods. Brain Behav 2013; 3:335-50. [PMID: 24381807 PMCID: PMC3869677 DOI: 10.1002/brb3.143] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 03/21/2013] [Accepted: 03/22/2013] [Indexed: 11/10/2022] Open
Abstract
Charcot first described amyotrophic lateral sclerosis (ALS) in 1869; however, its causes remain largely unknown and effective, long-term treatment strategies are not available. The first mouse model of ALS was developed after the identification of mutations in the superoxide dismutase 1 (SOD1) gene in 1993, and accordingly most of our knowledge of the etiology and pathogenesis of the disease comes from studies carried out using this animal model. Although numerous preclinical trials have been conducted in the mutant SOD1 mouse models, the results have been disappointing because they did not positively translate to clinical trials. One explanation may be that current understanding of when and where pathogenesis begins is insufficient to accurately guide preclinical trials. Further characterization of these early events may provide insight into disease onset, help in the discovery of presymptomatic diagnostic disease markers, and identify novel therapeutic targets. Here, we describe the rationale, approach, and methods for our extensive analysis of early changes that included an ultrastructural examination of central and peripheral components of the neuromuscular system in the SOD1(G93A) mouse and correlated these alterations with early muscle denervation, motor dysfunction, and motoneuron death. We also provide a discussion of published work to review what is known regarding early pathology in the SOD1 mouse model of ALS. The significance of this work is that we have examined early pathology simultaneously in both the spinal cord and peripheral neuromuscular system, and the results are presented in the companion paper (Part II, Results and Discussion). Our results provide evidence as to why a thorough characterization of animal models throughout the life span is critical for a strong foundation to design preclinical trials that may produce meaningful results.
Collapse
Affiliation(s)
- Sharon Vinsant
- Department of Neurobiology and Anatomy, The Neuroscience Program and The ALS Center Winston-Salem, North Carolina
| | - Carol Mansfield
- Department of Neurobiology and Anatomy, The Neuroscience Program and The ALS Center Winston-Salem, North Carolina
| | - Ramon Jimenez-Moreno
- Department of Neurobiology and Anatomy, The Neuroscience Program and The ALS Center Winston-Salem, North Carolina
| | | | - Masaaki Yoshikawa
- Department of Neurobiology and Anatomy, The Neuroscience Program and The ALS Center Winston-Salem, North Carolina
| | | | - David Prevette
- Department of Neurobiology and Anatomy, The Neuroscience Program and The ALS Center Winston-Salem, North Carolina
| | - James Caress
- Department of Neurology and the ALS Center, Wake Forest University School of Medicine Winston-Salem, North Carolina
| | - Ronald W Oppenheim
- Department of Neurobiology and Anatomy, The Neuroscience Program and The ALS Center Winston-Salem, North Carolina
| | - Carol Milligan
- Department of Neurobiology and Anatomy, The Neuroscience Program and The ALS Center Winston-Salem, North Carolina
| |
Collapse
|
46
|
Call JA, Warren GL, Verma M, Lowe DA. Acute failure of action potential conduction in mdx muscle reveals new mechanism of contraction-induced force loss. J Physiol 2013; 591:3765-76. [PMID: 23753524 DOI: 10.1113/jphysiol.2013.254656] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
A primary feature of skeletal muscle lacking the protein dystrophin, as occurring in Duchenne muscular dystrophy, is a hypersensitivity to contraction-induced strength loss. We tested the hypothesis that the extensive strength loss results from an impairment in the electrophysiological function of the plasmalemma specifically impaired action potential development. Anterior crural muscles from mdx and wildtype mice performed a single bout of 100 electrically stimulated eccentric contractions in vivo. Electromyography, specifically the M-wave, was analysed during muscle contraction to assess the ability of the tibialis anterior muscle plasmalemma to generate and conduct action potentials. During eccentric contractions, wildtype mice exhibited a 36% loss in torque about the ankle but mdx mice exhibited a greater torque loss of 73% (P < 0.001). Despite the loss of torque, there was no reduction in M-wave root mean square (RMS) for wildtype mice, which was in stark contrast to mdx mice that had a 55% reduction in M-wave RMS (P < 0.001). This impairment resolved within 24 h and coincided with a significant improvement in strength and membrane integrity. Intracellular measurements of resting membrane potential (RMP) in uninjured and injured extensor digitorum longus muscles were made to determine if a chronic depolarization had occurred, which could lead to impaired fibre excitability and/or altered action potential conduction properties. The distributions of RMP were not different between wildtype uninjured and injured muscle cells (median: -73.2 mV vs. -72.7 mV, P = 0.46) whereas there was a significant difference between mdx uninjured and injured cells (median: -71.5 mV vs. -56.6 mV, P < 0.001). These data show that mdx muscle fibres are depolarized after an injurious bout of eccentric contractions. These findings (i) suggest a major plasmalemma-based mechanism of strength loss underlying contraction-induced injury in Duchenne muscular dystrophy distinctly different from that for healthy muscle, and (ii) demonstrate dystrophin is critical for maintaining action potential generation and conduction after eccentric contractions.
Collapse
Affiliation(s)
- Jarrod A Call
- Programs in Rehabilitation Science and Physical Therapy, School of Medicine, University of Minnesota, Minneapolis, MN, USA.
| | | | | | | |
Collapse
|
47
|
Prosser BL, Khairallah RJ, Ziman AP, Ward CW, Lederer WJ. X-ROS signaling in the heart and skeletal muscle: stretch-dependent local ROS regulates [Ca²⁺]i. J Mol Cell Cardiol 2012; 58:172-81. [PMID: 23220288 DOI: 10.1016/j.yjmcc.2012.11.011] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 10/23/2012] [Accepted: 11/22/2012] [Indexed: 02/02/2023]
Abstract
X-ROS signaling is a novel redox signaling pathway that links mechanical stress to changes in [Ca(2+)]i. This pathway is activated rapidly and locally within a muscle cell under physiological conditions, but can also contribute to Ca(2+)-dependent arrhythmia in the heart and to the dystrophic phenotype in the heart and skeletal muscle. Upon physiologic cellular stretch, microtubules serve as mechanotransducers to activate NADPH oxidase 2 in the transverse tubules and sarcolemmal membranes to produce reactive oxygen species (ROS). In the heart, the ROS acts locally to activate ryanodine receptor Ca(2+) release channels in the junctional sarcoplasmic reticulum, increasing the Ca(2+) spark rate and "tuning" excitation-contraction coupling. In the skeletal muscle, where Ca(2+) sparks are not normally observed, the X-ROS signaling process is muted. However in muscular dystrophies, such as Duchenne Muscular Dystrophy and dysferlinopathy, X-ROS signaling operates at a high level and contributes to myopathy. Importantly, Ca(2+) permeable stretch-activated channels are activated by X-ROS and contribute to skeletal muscle pathology. Here we review X-ROS signaling and mechanotransduction in striated muscle, and highlight important questions to drive future work on stretch-dependent signaling. We conclude that X-ROS provides an exciting mechanism for the mechanical control of redox and Ca(2+) signaling, but much work is needed to establish its contribution to physiologic and pathophysiologic processes in diverse cell systems.
Collapse
Affiliation(s)
- Benjamin L Prosser
- Department of Physiology, Center for Biomedical Engineering and Technology (BioMET), University of Maryland School of Medicine, Baltimore, MD, USA
| | | | | | | | | |
Collapse
|
48
|
Vasquez I, Tan N, Boonyasampant M, Koppitch KA, Lansman JB. Partial opening and subconductance gating of mechanosensitive ion channels in dystrophic skeletal muscle. J Physiol 2012; 590:6167-85. [PMID: 22966155 PMCID: PMC3530124 DOI: 10.1113/jphysiol.2012.240044] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 09/03/2012] [Indexed: 12/31/2022] Open
Abstract
We recorded the activity of single mechanosensitive (MS) ion channels in skeletal muscle from the mdx mouse, a deletion mutant that lacks the cytoskeletal protein, dystrophin. Experiments were designed to examine the influence of dystrophin, a major component of skeletal muscle costameres, on the behaviour of single MS channels. In the majority of recordings from cell-attached patches, MS channels have a conductance of ∼23 pS. Recordings from some patches, however, showed a smaller conductance channel of ∼7-14 pS. Large and small conductance channels were detected in a single patch and showed serial, non-random gating, suggesting different opening levels of a single channel. Analysis of the distribution of current amplitudes within the open channel showed MS channels fluctuate between subconductance levels. MS channels in dystrophic muscle spend ∼60% of the time at smaller subconductance levels, often failing to reach the fully open level. Applying pressure to the membrane of mdx fibres increases in a graded manner occupancy of the fully open state, while reducing occupancy of subconductance levels. Recordings also show partial openings of MS channels in both wild-type and mdx muscle that fail to reach the fully open state. Partial openings occur at a higher frequency in mdx muscle and reflect occupancy of subconductance levels seen during complete activations. In muscle from mdx/utrn(-/-) double knockout mice, MS channels also spend more time at subconductance levels than the fully open state. Conductance variability of MS channels may represent gating of a heteromeric protein composed of different channel subunits. The results also show that partial opening and prolonged burst duration are distinct mechanisms that contribute to excess Ca(2+) entry in dystrophic muscle.
Collapse
Affiliation(s)
- Ivan Vasquez
- Department of Cellular & Molecular Pharmacology, School of Medicine, University of California, San Francisco, CA 94143-0450, USA
| | | | | | | | | |
Collapse
|
49
|
Eltit JM, Ding X, Pessah IN, Allen PD, Lopez JR. Nonspecific sarcolemmal cation channels are critical for the pathogenesis of malignant hyperthermia. FASEB J 2012; 27:991-1000. [PMID: 23159934 DOI: 10.1096/fj.12-218354] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Malignant hyperthermia (MH) susceptibility has been attributed to a leaky sarcoplasmic reticulum (SR) caused by missense mutations in RYR1 or CACNA1S, and the MH crisis has been attributed solely to massive self-sustaining release of Ca(2+) from SR stores elicited by triggering agents. Here, we show in muscle cells from MH-RyR1(R163C) knock-in mice that increased passive SR Ca(2+) leak causes an enlarged basal influx of sarcolemmal Ca(2+) that results in chronically elevated myoplasmic free Ca(2+) concentration ([Ca(2+)]i) at rest. We discovered that Gd(+3) and GsMTx-4 were more effective than BTP2 or expression of the dominant-negative Orai1(E190Q) in reducing both Ca(2+) entry and [Ca(2+)]i, implicating a non-STIM1/Orai1 SOCE pathway in resetting resting [Ca(2+)]i. Indeed, two nonselective cationic channels, TRPC3 and TRPC6, are overexpressed, and [Na]i is chronically elevated in MH-RyR1(R163C) muscle cells. [Ca(2+)]i and [Na(+)]i are persistently elevated in vivo and further increased by halothane in MH-RyR1(R163C/WT) muscle. These increases are markedly attenuated by local perfusion of Gd(+3) or GsMTx-4 and completely suppressed by dantrolene. These results contribute a new paradigm for understanding MH pathophysiology by demonstrating that nonselective sarcolemmal cation channel activity plays a critical role in causing myoplasmic Ca(2+) and Na(+) overload both at rest and during the MH crisis.-Eltit, J. M., Ding, X., Pessah, I. N., Allen, P. D., Lopez, J. R. Nonspecific sarcolemmal cation channels are critical for the pathogenesis of malignant hyperthermia.
Collapse
Affiliation(s)
- José M Eltit
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
| | | | | | | | | |
Collapse
|
50
|
Contribution of oxidative stress to pathology in diaphragm and limb muscles with Duchenne muscular dystrophy. J Muscle Res Cell Motil 2012; 34:1-13. [DOI: 10.1007/s10974-012-9330-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 10/18/2012] [Indexed: 11/27/2022]
|