1
|
Dowling P, Gargan S, Swandulla D, Ohlendieck K. Proteomic profiling of impaired excitation-contraction coupling and abnormal calcium handling in muscular dystrophy. Proteomics 2022; 22:e2200003. [PMID: 35902360 PMCID: PMC10078611 DOI: 10.1002/pmic.202200003] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/19/2022] [Accepted: 07/25/2022] [Indexed: 11/06/2022]
Abstract
The X-linked inherited neuromuscular disorder Duchenne muscular dystrophy is characterised by primary abnormalities in the membrane cytoskeletal component dystrophin. The almost complete absence of the Dp427-M isoform of dystrophin in skeletal muscles renders contractile fibres more susceptible to progressive degeneration and a leaky sarcolemma membrane. This in turn results in abnormal calcium homeostasis, enhanced proteolysis and impaired excitation-contraction coupling. Biochemical and mass spectrometry-based proteomic studies of both patient biopsy specimens and genetic animal models of dystrophinopathy have demonstrated significant changes in the concentration and/or physiological function of essential calcium-regulatory proteins in dystrophin-lacking voluntary muscles. Abnormalities include dystrophinopathy-associated changes in voltage sensing receptors, calcium release channels, calcium pumps and calcium binding proteins. This review article provides an overview of the importance of the sarcolemmal dystrophin-glycoprotein complex and the wider dystrophin complexome in skeletal muscle and its linkage to depolarisation-induced calcium-release mechanisms and the excitation-contraction-relaxation cycle. Besides chronic inflammation, fat substitution and reactive myofibrosis, a major pathobiochemical hallmark of X-linked muscular dystrophy is represented by the chronic influx of calcium ions through the damaged plasmalemma in conjunction with abnormal intracellular calcium fluxes and buffering. Impaired calcium handling proteins should therefore be included in an improved biomarker signature of Duchenne muscular dystrophy.
Collapse
Affiliation(s)
- Paul Dowling
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare, Ireland.,Kathleen Lonsdale Institute for Human Health Research, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Stephen Gargan
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare, Ireland.,Kathleen Lonsdale Institute for Human Health Research, Maynooth University, Maynooth, Co. Kildare, Ireland
| | | | - Kay Ohlendieck
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare, Ireland.,Kathleen Lonsdale Institute for Human Health Research, Maynooth University, Maynooth, Co. Kildare, Ireland
| |
Collapse
|
2
|
Cully TR, Rodney GG. Nox4 - RyR1 - Nox2: Regulators of micro-domain signaling in skeletal muscle. Redox Biol 2020; 36:101557. [PMID: 32506037 PMCID: PMC7283154 DOI: 10.1016/j.redox.2020.101557] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/10/2020] [Accepted: 04/23/2020] [Indexed: 12/22/2022] Open
Abstract
The ability for skeletal muscle to perform optimally can be affected by the regulation of Ca2+ within the triadic junctional space at rest. Reactive oxygen species impact muscle performance due to changes in oxidative stress, damage and redox regulation of signaling cascades. The interplay between ROS and Ca2+ signaling at the triad of skeletal muscle is therefore important to understand as it can impact the performance of healthy and diseased muscle. Here, we aimed to examine how changes in Ca2+ and redox signaling within the junctional space micro-domain of the mouse skeletal muscle fibre alters the homeostasis of these complexes. The dystrophic mdx mouse model displays increased RyR1 Ca2+ leak and increased NAD(P)H Oxidase 2 ROS. These alterations make the mdx mouse an ideal model for understanding how ROS and Ca2+ handling impact each other. We hypothesised that elevated t-tubular Nox2 ROS increases RyR1 Ca2+ leak contributing to an increase in cytoplasmic Ca2+, which could then initiate protein degradation and impaired cellular functions such as autophagy and ER stress. We found that inhibiting Nox2 ROS did not decrease RyR1 Ca2+ leak observed in dystrophin-deficient skeletal muscle. Intriguingly, another NAD(P)H isoform, Nox4, is upregulated in mice unable to produce Nox2 ROS and when inhibited reduced RyR1 Ca2+ leak. Our findings support a model in which Nox4 ROS induces RyR1 Ca2+ leak and the increased junctional space [Ca2+] exacerbates Nox2 ROS; with the cumulative effect of disruption of downstream cellular processes that would ultimately contribute to reduced muscle or cellular performance. Nox2 ROS does not influence RyR1 Ca2+ leak in skeletal muscle. Lack of Nox2 ROS increases Nox4 expression. Nox4 ROS induces RyR1 Ca2+ leak via S-nitrosylation.
Collapse
Affiliation(s)
- Tanya R Cully
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - George G Rodney
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA.
| |
Collapse
|
3
|
Thakur SS, Swiderski K, Ryall JG, Lynch GS. Therapeutic potential of heat shock protein induction for muscular dystrophy and other muscle wasting conditions. Philos Trans R Soc Lond B Biol Sci 2018; 373:rstb.2016.0528. [PMID: 29203713 DOI: 10.1098/rstb.2016.0528] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2017] [Indexed: 02/03/2023] Open
Abstract
Duchenne muscular dystrophy is the most common and severe of the muscular dystrophies, a group of inherited myopathies caused by different genetic mutations leading to aberrant expression or complete absence of cytoskeletal proteins. Dystrophic muscles are prone to injury, and regenerate poorly after damage. Remorseless cycles of muscle fibre breakdown and incomplete repair lead to progressive and severe muscle wasting, weakness and premature death. Many other conditions are similarly characterized by muscle wasting, including sarcopenia, cancer cachexia, sepsis, denervation, burns, and chronic obstructive pulmonary disease. Muscle trauma and loss of mass and physical capacity can significantly compromise quality of life for patients. Exercise and nutritional interventions are unlikely to halt or reverse the conditions, and strategies promoting muscle anabolism have limited clinical acceptance. Heat shock proteins (HSPs) are molecular chaperones that help proteins fold back to their original conformation and restore function. Since many muscle wasting conditions have pathophysiologies where inflammation, atrophy and weakness are indicated, increasing HSP expression in skeletal muscle may have therapeutic potential. This review will provide evidence supporting HSP induction for muscular dystrophy and other muscle wasting conditions.This article is part of the theme issue 'Heat shock proteins as modulators and therapeutic targets of chronic disease: an integrated perspective'.
Collapse
Affiliation(s)
- Savant S Thakur
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
| | - Kristy Swiderski
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
| | - James G Ryall
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
| | - Gordon S Lynch
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
4
|
曾 林, 刘 静. [Mitochondrial calcium overload in the masseter muscle of rats with occlusal interference: ionic changes and regulation by calmodulin kinase II]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2018; 38:755-760. [PMID: 29997101 PMCID: PMC6765715 DOI: 10.3969/j.issn.1673-4254.2018.06.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Indexed: 06/08/2023]
Abstract
OBJECTIVE To investigate the changes in mitochondrial calcium and extracellular sodium concentrations in the masseter muscle of rats with occlusal interference and the regulatory mechanism of mitochondrial Ca2+ overload by calmodulin kinase II (CaMK II). METHODS SD rat models of occlusal interference were established by placing a stainless steel segments (0.8 mm in diameter) to raise the occlusal surface of the upper right first molar. At 3, 7, 14, and 21 days after occlusal interference and at 3 days after removal of occlusal interference, HE staining was used to observe the histomorphological changes of the masseter muscle. Mitochondrial calcium concentration in the masseter muscle was detected using fluorescence spectrophotometry, and direct turbidimetry with potassium pyroantimonate was used to detect the extracellular sodium concentration; the expression levels of masseter muscle p-CaMK II (Thr287) and CaMK II were detected using Western blotting. RESULTS Compared with those in the corresponding control groups, mitochondrial Ca2+ concentration in the masseter muscle on occlusal interference side increased significantly at 3, 7, 14 and 21 days after occlusal interference (P<0.05), but was significantly lowered at 3 days after removal of the interference (P<0.05). The concentration of extracellular Na+ increased progressively with time at 3, 7, 14 and 21 days after occlusal interference (P<0.05), and was significantly decreased at 3 days after interference removal (P<0.05). Occlusal interference for 3, 7 and 14 days resulted in significantly increased expressions of p-CaMK II (Thr287) and CaMK II (P<0.05), which was significantly decreased at 21 days compared with those in the control groups (P<0.05) and further decreased after removal of occlusal interference (P<0.05). Similar changes were also observed on the side without interference, but the changes on the interference side were more obvious (P<0.05). CONCLUSION Occlusal interference causes elevated mitochondrial Ca2+ and extracellular Na+ concentrations in the masseter muscle of rats to lead to calcium overload; the increase in mitochondrial Ca2+ concentration is correlated with the phosphorylation level of CaMK II signaling pathway, suggesting a negative feedback regulation mechanism by the CaMK II signal pathway.
Collapse
Affiliation(s)
- 林 曾
- 暨南大学 口腔医学院,广东 广州 510632College of Stomatology, Jinan University, Guangzhou 510632, China
- 华侨医院口腔科,广东 广州 510630Department of Stomatology, First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - 静 刘
- 暨南大学 口腔医学院修复学教研室,广东 广州 510632Department of Prosthodontics, College of Stomatology, Jinan University, Guangzhou 510632, China
| |
Collapse
|
5
|
Abstract
PURPOSE OF REVIEW Nuclear envelope links to a wide range of disorders, including several myopathies and neuropathies over the past 2 decades, has spurred research leading to a completely changed view of this important cellular structure and its functions. However, the many functions now assigned to the nuclear envelope make it increasingly hard to determine which functions underlie these disorders. RECENT FINDINGS New nuclear envelope functions in genome organization, regulation and repair, signaling, and nuclear and cellular mechanics have been added to its classical barrier function. Arguments can be made for any of these functions mediating abnormality in nuclear envelope disorders and data exist supporting many. Moreover, transient and/or distal nuclear envelope connections to other cellular proteins and structures may increase the complexity of these disorders. SUMMARY Although the increased understanding of nuclear envelope functions has made it harder to distinguish specific causes of nuclear envelope disorders, this is because it has greatly expanded the spectrum of possible mechanisms underlying them. This change in perspective applies well beyond the known nuclear envelope disorders, potentially implicating the nuclear envelope in a much wider range of myopathies and neuropathies.
Collapse
|
6
|
Lukyanenko V, Muriel JM, Bloch RJ. Coupling of excitation to Ca 2+ release is modulated by dysferlin. J Physiol 2017; 595:5191-5207. [PMID: 28568606 DOI: 10.1113/jp274515] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 05/16/2017] [Indexed: 12/16/2022] Open
Abstract
KEY POINTS Dysferlin, the protein missing in limb girdle muscular dystrophy 2B and Miyoshi myopathy, concentrates in transverse tubules of skeletal muscle, where it stabilizes voltage-induced Ca2+ transients against loss after osmotic shock injury (OSI). Local expression of dysferlin in dysferlin-null myofibres increases transient amplitude to control levels and protects them from loss after OSI. Inhibitors of ryanodine receptors (RyR1) and L-type Ca2+ channels protect voltage-induced Ca2+ transients from loss; thus both proteins play a role in injury in dysferlin's absence. Effects of Ca2+ -free medium and S107, which inhibits SR Ca2+ leak, suggest the SR as the primary source of Ca2+ responsible for the loss of the Ca2+ transient upon injury. Ca2+ waves were induced by OSI and suppressed by exogenous dysferlin. We conclude that dysferlin prevents injury-induced SR Ca2+ leak. ABSTRACT Dysferlin concentrates in the transverse tubules of skeletal muscle and stabilizes Ca2+ transients when muscle fibres are subjected to osmotic shock injury (OSI). We show here that voltage-induced Ca2+ transients elicited in dysferlin-null A/J myofibres were smaller than control A/WySnJ fibres. Regional expression of Venus-dysferlin chimeras in A/J fibres restored the full amplitude of the Ca2+ transients and protected against OSI. We also show that drugs that target ryanodine receptors (RyR1: dantrolene, tetracaine, S107) and L-type Ca2+ channels (LTCCs: nifedipine, verapamil, diltiazem) prevented the decrease in Ca2+ transients in A/J fibres following OSI. Diltiazem specifically increased transients by ∼20% in uninjured A/J fibres, restoring them to control values. The fact that both RyR1s and LTCCs were involved in OSI-induced damage suggests that damage is mediated by increased Ca2+ leak from the sarcoplasmic reticulum (SR) through the RyR1. Congruent with this, injured A/J fibres produced Ca2+ sparks and Ca2+ waves. S107 (a stabilizer of RyR1-FK506 binding protein coupling that reduces Ca2+ leak) or local expression of Venus-dysferlin prevented OSI-induced Ca2+ waves. Our data suggest that dysferlin modulates SR Ca2+ release in skeletal muscle, and that in its absence OSI causes increased RyR1-mediated Ca2+ leak from the SR into the cytoplasm.
Collapse
Affiliation(s)
- Valeriy Lukyanenko
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Joaquin M Muriel
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Robert J Bloch
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| |
Collapse
|
7
|
Dulhunty AF, Board PG, Beard NA, Casarotto MG. Physiology and Pharmacology of Ryanodine Receptor Calcium Release Channels. ADVANCES IN PHARMACOLOGY 2017; 79:287-324. [DOI: 10.1016/bs.apha.2016.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
8
|
Rebbeck RT, Essawy MM, Nitu FR, Grant BD, Gillispie GD, Thomas DD, Bers DM, Cornea RL. High-Throughput Screens to Discover Small-Molecule Modulators of Ryanodine Receptor Calcium Release Channels. SLAS DISCOVERY 2016; 22:176-186. [PMID: 27760856 DOI: 10.1177/1087057116674312] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Using time-resolved fluorescence resonance energy transfer (FRET), we have developed and validated the first high-throughput screening (HTS) method to discover compounds that modulate an intracellular Ca2+ channel, the ryanodine receptor (RyR), for therapeutic applications. Intracellular Ca2+ regulation is critical for striated muscle function, and RyR is a central player. At resting [Ca2+], an increased propensity of channel opening due to RyR dysregulation is associated with severe cardiac and skeletal myopathies, diabetes, and neurological disorders. This leaky state of the RyR is an attractive target for pharmacological agents to treat such pathologies. Our FRET-based HTS detects RyR binding of accessory proteins calmodulin (CaM) or FKBP12.6. Under conditions that mimic a pathological state, we carried out a screen of the 727-compound NIH Clinical Collection, which yielded six compounds that reproducibly changed FRET by >3 SD. Dose-response of FRET and [3H]ryanodine binding readouts reveal that five hits reproducibly alter RyR1 structure and activity. One compound increased FRET and inhibited RyR1, which was only significant at nM [Ca2+], and accentuated without CaM present. These properties characterize a compound that could mitigate RyR1 leak. An excellent Z' factor and the tight correlation between structural and functional readouts validate this first HTS method to identify RyR modulators.
Collapse
Affiliation(s)
- Robyn T Rebbeck
- 1 Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Maram M Essawy
- 1 Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Florentin R Nitu
- 1 Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | | | | | - David D Thomas
- 1 Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Donald M Bers
- 3 Department of Pharmacology, University of California, Davis, CA, USA
| | - Razvan L Cornea
- 1 Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|