1
|
Lee E, May H, Kazmierczak K, Liang J, Nguyen N, Hill JA, Gillette TG, Szczesna-Cordary D, Chang AN. The MYPT2-regulated striated muscle-specific myosin light chain phosphatase limits cardiac myosin phosphorylation in vivo. J Biol Chem 2024; 300:105652. [PMID: 38224947 PMCID: PMC10851227 DOI: 10.1016/j.jbc.2024.105652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 01/02/2024] [Accepted: 01/04/2024] [Indexed: 01/17/2024] Open
Abstract
The physiological importance of cardiac myosin regulatory light chain (RLC) phosphorylation by its dedicated cardiac myosin light chain kinase has been established in both humans and mice. Constitutive RLC-phosphorylation, regulated by the balanced activities of cardiac myosin light chain kinase and myosin light chain phosphatase (MLCP), is fundamental to the biochemical and physiological properties of myofilaments. However, limited information is available on cardiac MLCP. In this study, we hypothesized that the striated muscle-specific MLCP regulatory subunit, MYPT2, targets the phosphatase catalytic subunit to cardiac myosin, contributing to the maintenance of cardiac function in vivo through the regulation of RLC-phosphorylation. To test this hypothesis, we generated a floxed-PPP1R12B mouse model crossed with a cardiac-specific Mer-Cre-Mer to conditionally ablate MYPT2 in adult cardiomyocytes. Immunofluorescence microscopy using the gene-ablated tissue as a control confirmed the localization of MYPT2 to regions where it overlaps with a subset of RLC. Biochemical analysis revealed an increase in RLC-phosphorylation in vivo. The loss of MYPT2 demonstrated significant protection against pressure overload-induced hypertrophy, as evidenced by heart weight, qPCR of hypertrophy-associated genes, measurements of myocyte diameters, and expression of β-MHC protein. Furthermore, mantATP chase assays revealed an increased ratio of myosin heads distributed to the interfilament space in MYPT2-ablated heart muscle fibers, confirming that RLC-phosphorylation regulated by MLCP, enhances cardiac performance in vivo. Our findings establish MYPT2 as the regulatory subunit of cardiac MLCP, distinct from the ubiquitously expressed canonical smooth muscle MLCP. Targeting MYPT2 to increase cardiac RLC-phosphorylation in vivo may improve baseline cardiac performance, thereby attenuating pathological hypertrophy.
Collapse
Affiliation(s)
- Eunyoung Lee
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Herman May
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Katarzyna Kazmierczak
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Jingsheng Liang
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Nhu Nguyen
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Joseph A Hill
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Thomas G Gillette
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Danuta Szczesna-Cordary
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Audrey N Chang
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Pak Center for Mineral Metabolism and Clinical Research, UTSW Medical Center, Dallas, Texas, USA.
| |
Collapse
|
2
|
Peyton MP, Yang TY, Higgins L, Markowski TW, Murray K, Vue C, Parker LL, Lowe DA. Natural aging and ovariectomy induces parallel phosphoproteomic alterations in skeletal muscle of female mice. Aging (Albany NY) 2023; 15:7362-7380. [PMID: 37580837 PMCID: PMC10457050 DOI: 10.18632/aging.204959] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 07/24/2023] [Indexed: 08/16/2023]
Abstract
The loss of skeletal muscle strength mid-life in females is associated with the decline of estrogen. Here, we questioned how estrogen deficiency might impact the overall skeletal muscle phosphoproteome after contraction, as force production induces phosphorylation of several muscle proteins. Phosphoproteomic analyses of the tibialis anterior muscle after contraction in two mouse models of estrogen deficiency, ovariectomy (Ovariectomized (Ovx) vs. Sham) and natural aging-induced ovarian senescence (Older Adult (OA) vs. Young Adult (YA)), identified a total of 2,593 and 3,507 phosphopeptides in Ovx/Sham and OA/YA datasets, respectively. Further analysis of estrogen deficiency-associated proteins and phosphosites identified 66 proteins and 21 phosphosites from both datasets. Of these, 4 estrogen deficiency-associated proteins and 4 estrogen deficiency-associated phosphosites were significant and differentially phosphorylated or regulated, respectively. Comparative analyses between Ovx/Sham and OA/YA using Ingenuity Pathway Analysis (IPA) found parallel patterns of inhibition and activation across IPA-defined canonical signaling pathways and physiological functional analysis, which were similarly observed in downstream GO, KEGG, and Reactome pathway overrepresentation analysis pertaining to muscle structural integrity and contraction, including AMPK and calcium signaling. IPA Upstream regulator analysis identified MAPK1 and PRKACA as candidate kinases and calcineurin as a candidate phosphatase sensitive to estrogen. Our findings highlight key molecular signatures and pathways in contracted muscle suggesting that the similarities identified across both datasets could elucidate molecular mechanisms that may contribute to skeletal muscle strength loss due to estrogen deficiency.
Collapse
Affiliation(s)
- Mina P. Peyton
- Department of Rehabilitation Medicine, Division of Rehabilitation Science, University of Minnesota – Twin Cities, Minneapolis, MN 55455, USA
- Department of Computer Science, Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, MN 55455, USA
| | - Tzu-Yi Yang
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota – Twin Cities, Minneapolis, MN 55455, USA
| | - LeeAnn Higgins
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota – Twin Cities, Minneapolis, MN 55455, USA
| | - Todd W. Markowski
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota – Twin Cities, Minneapolis, MN 55455, USA
| | - Kevin Murray
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota – Twin Cities, Minneapolis, MN 55455, USA
| | - Cha Vue
- Department of Rehabilitation Medicine, Division of Rehabilitation Science, University of Minnesota – Twin Cities, Minneapolis, MN 55455, USA
| | - Laurie L. Parker
- Department of Computer Science, Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, MN 55455, USA
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota – Twin Cities, Minneapolis, MN 55455, USA
| | - Dawn A. Lowe
- Department of Rehabilitation Medicine, Division of Rehabilitation Science, University of Minnesota – Twin Cities, Minneapolis, MN 55455, USA
- Department of Rehabilitation Medicine, Division of Physical Therapy, University of Minnesota – Twin Cities, Minneapolis, MN 55455, USA
| |
Collapse
|
3
|
Martin AA, Thompson BR, Hahn D, Angulski ABB, Hosny N, Cohen H, Metzger JM. Cardiac Sarcomere Signaling in Health and Disease. Int J Mol Sci 2022; 23:16223. [PMID: 36555864 PMCID: PMC9782806 DOI: 10.3390/ijms232416223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022] Open
Abstract
The cardiac sarcomere is a triumph of biological evolution wherein myriad contractile and regulatory proteins assemble into a quasi-crystalline lattice to serve as the central point upon which cardiac muscle contraction occurs. This review focuses on the many signaling components and mechanisms of regulation that impact cardiac sarcomere function. We highlight the roles of the thick and thin filament, both as necessary structural and regulatory building blocks of the sarcomere as well as targets of functionally impactful modifications. Currently, a new focus emerging in the field is inter-myofilament signaling, and we discuss here the important mediators of this mechanism, including myosin-binding protein C and titin. As the understanding of sarcomere signaling advances, so do the methods with which it is studied. This is reviewed here through discussion of recent live muscle systems in which the sarcomere can be studied under intact, physiologically relevant conditions.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Joseph M. Metzger
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| |
Collapse
|
4
|
Peyton MP, Yang TY, Higgins L, Markowski TW, Vue C, Parker LL, Lowe DA. Global phosphoproteomic profiling of skeletal muscle in ovarian hormone-deficient mice. Physiol Genomics 2022; 54:417-432. [PMID: 36062884 PMCID: PMC9639773 DOI: 10.1152/physiolgenomics.00104.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/05/2022] [Accepted: 08/30/2022] [Indexed: 11/22/2022] Open
Abstract
Protein phosphorylation is important in skeletal muscle development, growth, regeneration, and contractile function. Alterations in the skeletal muscle phosphoproteome due to aging have been reported in males; however, studies in females are lacking. We have demonstrated that estrogen deficiency decreases muscle force, which correlates with decreased myosin regulatory light chain phosphorylation. Thus, we questioned whether the decline of estrogen in females that occurs with aging might alter the skeletal muscle phosphoproteome. C57BL/6J female mice (6 mo) were randomly assigned to a sham-operated (Sham) or ovariectomy (Ovx) group to investigate the effects of estrogen deficiency on skeletal muscle protein phosphorylation in a resting, noncontracting condition. After 16 wk of estrogen deficiency, the tibialis anterior muscle was dissected and prepped for label-free nano-liquid chromatography-tandem mass spectrometry phosphoproteomic analysis. We identified 4,780 phosphopeptides in tibialis anterior muscles of ovariectomized (Ovx) and Sham-operated (Sham) control mice. Further analysis revealed 647 differentially regulated phosphopeptides (Benjamini-Hochberg adjusted P value < 0.05 and 1.5-fold change ratio) that corresponded to 130 proteins with 22 proteins differentially phosphorylated (3 unique to Ovx, 2 unique to Sham, 6 upregulated, and 11 downregulated). Differentially phosphorylated proteins associated with the sarcomere, cytoplasm, and metabolic and calcium signaling pathways were identified. Our work provides the first global phosphoproteomic analysis in females and how estrogen deficiency impacts the skeletal muscle phosphoproteome.
Collapse
Affiliation(s)
- Mina P Peyton
- Division of Rehabilitation Science, Department of Rehabilitation Medicine, University of Minnesota, Twin Cities, Minneapolis, Minnesota
- Department of Computer Science, Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, Minnesota
| | - Tzu-Yi Yang
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Twin Cities, Minneapolis, Minnesota
| | - LeeAnn Higgins
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Twin Cities, Minneapolis, Minnesota
| | - Todd W Markowski
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Twin Cities, Minneapolis, Minnesota
| | - Cha Vue
- Division of Rehabilitation Science, Department of Rehabilitation Medicine, University of Minnesota, Twin Cities, Minneapolis, Minnesota
| | - Laurie L Parker
- Department of Computer Science, Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, Minnesota
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Twin Cities, Minneapolis, Minnesota
| | - Dawn A Lowe
- Division of Rehabilitation Science, Department of Rehabilitation Medicine, University of Minnesota, Twin Cities, Minneapolis, Minnesota
- Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Twin Cities, Minneapolis, Minnesota
| |
Collapse
|
5
|
Liu Y, Hu YJ, Fan WX, Quan X, Xu B, Li SZ. O-GlcNAcylation: The Underestimated Emerging Regulators of Skeletal Muscle Physiology. Cells 2022; 11:cells11111789. [PMID: 35681484 PMCID: PMC9180116 DOI: 10.3390/cells11111789] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/13/2022] [Accepted: 05/17/2022] [Indexed: 02/04/2023] Open
Abstract
O-GlcNAcylation is a highly dynamic, reversible and atypical glycosylation that regulates the activity, biological function, stability, sublocation and interaction of target proteins. O-GlcNAcylation receives and coordinates different signal inputs as an intracellular integrator similar to the nutrient sensor and stress receptor, which target multiple substrates with spatio-temporal analysis specifically to maintain cellular homeostasis and normal physiological functions. Our review gives a brief description of O-GlcNAcylation and its only two processing enzymes and HBP flux, which will help to better understand its physiological characteristics of sensing nutrition and environmental cues. This nutritional and stress-sensitive properties of O-GlcNAcylation allow it to participate in the precise regulation of skeletal muscle metabolism. This review discusses the mechanism of O-GlcNAcylation to alleviate metabolic disorders and the controversy about the insulin resistance of skeletal muscle. The level of global O-GlcNAcylation is precisely controlled and maintained in the “optimal zone”, and its abnormal changes is a potential factor in the pathogenesis of cancer, neurodegeneration, diabetes and diabetic complications. Although the essential role of O-GlcNAcylation in skeletal muscle physiology has been widely studied and recognized, it still is underestimated and overlooked. This review highlights the latest progress and potential mechanisms of O-GlcNAcylation in the regulation of skeletal muscle contraction and structural properties.
Collapse
Affiliation(s)
| | | | | | | | - Bin Xu
- Correspondence: (B.X.); (S.-Z.L.)
| | | |
Collapse
|
6
|
Wang T, Spahiu E, Osten J, Behrens F, Grünhagen F, Scholz T, Kraft T, Nayak A, Amrute-Nayak M. Cardiac ventricular myosin and slow skeletal myosin exhibit dissimilar chemomechanical properties despite bearing the same myosin heavy chain isoform. J Biol Chem 2022; 298:102070. [PMID: 35623390 PMCID: PMC9243179 DOI: 10.1016/j.jbc.2022.102070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 05/12/2022] [Accepted: 05/14/2022] [Indexed: 11/29/2022] Open
Abstract
The myosin II motors are ATP-powered force-generating machines driving cardiac and muscle contraction. Myosin II heavy chain isoform-beta (β-MyHC) is primarily expressed in the ventricular myocardium and in slow-twitch muscle fibers, such as M. soleus. M. soleus–derived myosin II (SolM-II) is often used as an alternative to the ventricular β-cardiac myosin (βM-II); however, the direct assessment of biochemical and mechanical features of the native myosins is limited. By employing optical trapping, we examined the mechanochemical properties of native myosins isolated from the rabbit heart ventricle and soleus muscles at the single-molecule level. We found purified motors from the two tissue sources, despite expressing the same MyHC isoform, displayed distinct motile and ATPase kinetic properties. We demonstrate βM-II was approximately threefold faster in the actin filament–gliding assay than SolM-II. The maximum actomyosin (AM) detachment rate derived in single-molecule assays was also approximately threefold higher in βM-II, while the power stroke size and stiffness of the “AM rigor” crossbridge for both myosins were comparable. Our analysis revealed a higher AM detachment rate for βM-II, corresponding to the enhanced ADP release rates from the crossbridge, likely responsible for the observed differences in the motility driven by these myosins. Finally, we observed a distinct myosin light chain 1 isoform (MLC1sa) that associates with SolM-II, which might contribute to the observed kinetics differences between βM-II and SolM-II. These results have important implications for the choice of tissue sources and justify prerequisites for the correct myosin heavy and light chains to study cardiomyopathies.
Collapse
Affiliation(s)
- Tianbang Wang
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Emrulla Spahiu
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Jennifer Osten
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Florentine Behrens
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Fabius Grünhagen
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Tim Scholz
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Theresia Kraft
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Arnab Nayak
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany.
| | - Mamta Amrute-Nayak
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany.
| |
Collapse
|
7
|
Oya R, Tsukamoto O, Hitsumoto T, Nakahara N, Okamoto C, Matsuoka K, Kato H, Inohara H, Takashima S. Gene Transfer of Skeletal Muscle-Type Myosin Light Chain Kinase via Adeno-Associated Virus 6 Improves Muscle Functions in an Amyotrophic Lateral Sclerosis Mouse Model. Int J Mol Sci 2022; 23:1747. [PMID: 35163674 PMCID: PMC8836241 DOI: 10.3390/ijms23031747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/29/2022] [Accepted: 02/01/2022] [Indexed: 12/04/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that shows progressive muscle weakness. A few treatments exist including symptomatic therapies, which can prolong survival or reduce a symptom; however, no fundamental therapies have been found. As a therapeutic strategy, enhancing muscle force is important for patients' quality of life. In this study, we focused on skeletal muscle-specific myosin regulatory light chain kinase (skMLCK), which potentially enhances muscle contraction, as overexpression of skMLCK was thought to improve muscle function. The adeno-associated virus serotype 6 encoding skMLCK (AAV6/skMLCK) and eGFP (control) was produced and injected intramuscularly into the lower limbs of SOD1G37R mice, which are a familial ALS model. AAV6/skMLCK showed the successful expression of skMLCK in the muscle tissues. Although the control did not affect the muscle force in both of the WT and SOD1G37R mice, AAV6/skMLCK enhanced the twitch force of SOD1G37R mice and the tetanic force of WT and SOD1G37R mice. These results indicate that overexpression of skMLCK can enhance the tetanic force of healthy muscle as well as rescue weakened muscle function. In conclusion, the gene transfer of skMLCK has the potential to be a new therapy for ALS as well as for other neuromuscular diseases.
Collapse
Affiliation(s)
- Ryohei Oya
- Department of Medical Biochemistry, Osaka University Graduate School of Medicine/Frontier Biosciences, Osaka 565-0871, Japan; (R.O.); (T.H.); (C.O.); (K.M.); (H.K.); (S.T.)
- Department of Otorhinolaryngology Head and Neck Surgery, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan;
| | - Osamu Tsukamoto
- Department of Medical Biochemistry, Osaka University Graduate School of Medicine/Frontier Biosciences, Osaka 565-0871, Japan; (R.O.); (T.H.); (C.O.); (K.M.); (H.K.); (S.T.)
| | - Tatsuro Hitsumoto
- Department of Medical Biochemistry, Osaka University Graduate School of Medicine/Frontier Biosciences, Osaka 565-0871, Japan; (R.O.); (T.H.); (C.O.); (K.M.); (H.K.); (S.T.)
| | - Naoya Nakahara
- Department of Molecular Physiology, The Jikei University School of Medicine, Tokyo 105-8461, Japan;
| | - Chisato Okamoto
- Department of Medical Biochemistry, Osaka University Graduate School of Medicine/Frontier Biosciences, Osaka 565-0871, Japan; (R.O.); (T.H.); (C.O.); (K.M.); (H.K.); (S.T.)
| | - Ken Matsuoka
- Department of Medical Biochemistry, Osaka University Graduate School of Medicine/Frontier Biosciences, Osaka 565-0871, Japan; (R.O.); (T.H.); (C.O.); (K.M.); (H.K.); (S.T.)
| | - Hisakazu Kato
- Department of Medical Biochemistry, Osaka University Graduate School of Medicine/Frontier Biosciences, Osaka 565-0871, Japan; (R.O.); (T.H.); (C.O.); (K.M.); (H.K.); (S.T.)
| | - Hidenori Inohara
- Department of Otorhinolaryngology Head and Neck Surgery, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan;
| | - Seiji Takashima
- Department of Medical Biochemistry, Osaka University Graduate School of Medicine/Frontier Biosciences, Osaka 565-0871, Japan; (R.O.); (T.H.); (C.O.); (K.M.); (H.K.); (S.T.)
| |
Collapse
|
8
|
Zero AM, Rice CL. Post-activation potentiation induced by concentric contractions at three speeds in humans. Exp Physiol 2021; 106:2489-2501. [PMID: 34569107 DOI: 10.1113/ep089613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 09/23/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Is the degree of in human muscle affected by different shortening velocities, or contraction type? What are the main findings and their importance? The PAP response following maximal concentric contractions was independent of velocity. Slow and moderate velocity maximal contractions produced PAP responses like those from maximal isometric contractions when matched for contraction duration. Despite contraction type differences in cross-bridge and Ca2+ kinetics, maximal contractions, regardless of contraction modality, likely generate sufficient Ca2+ to induce maximal PAP. ABSTRACT Post-activation potentiation (PAP) is the acute enhancement of contractile properties following a brief (<10 s) high-intensity contraction. Compared with isometric contractions, little is known about the PAP response induced by concentric conditioning contractions (CCs) and the effect of velocity. In the dorsiflexors of 11 participants, twitch responses were measured following 5 s of maximal effort concentric CCs at each of 10, 20 and 50°/s. Concentric PAP responses were compared to a maximal isometric voluntary contraction (MVC) matched for contraction time. Additionally, concentric CCs were compared to isometric CCs matched for mean torque, contraction area and time. The PAP response following maximal concentric CCs was independent of velocity and there was no difference in the PAP response between concentric CCs and an isometric MVC. During maximal contractions, regardless of contraction modality, there is likely sufficient Ca2+ to induce a similar full PAP response, and thus there was no difference between speeds or contraction type. Following concentric CCs there was a significantly larger peak twitch torque than following their isometric torque matches (49-58%), and faster maximal rates of torque development at the three speeds (62-77%). However, these responses are likely related to greater EMG in concentric contractions, 125-129% of isometric maximum compared to 38-54%, and not to contraction modality per se. Thus, PAP responses following maximal concentric CCs are not affected by velocity and responses are not different from an isometric MVC. This indicates maximal CCs of 5 s produce a maximal PAP response independent of contraction type (isometric vs. concentric) or shortening velocity.
Collapse
Affiliation(s)
- Alexander M Zero
- School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, ON, Canada
| | - Charles L Rice
- School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, ON, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada
| |
Collapse
|
9
|
Zhu YC, Jin FH, Zhang MY, Qi F. Inhibition of Peripheral ERK Signaling Ameliorates Persistent Muscle Pain Around Trigger Points in Rats. Cell Transplant 2021; 29:963689720960190. [PMID: 33081508 PMCID: PMC7784566 DOI: 10.1177/0963689720960190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The purpose of this study was to investigate whether the ERK signaling pathway was involved in ameliorating chronic myofascial hyperalgesia from contused gastrocnemius muscle in rats. We established an animal model associated with myofascial pain syndrome and described the mechanism of muscle pain in an animal model. Changes in the mechanical pain threshold were observed 0.5, 1, 2, 3, 4, 5, 8, 12, 18, and 24 h after ERK inhibitor injection around myofascial trigger points (MTrPs) of the gastrocnemius muscle in rats. Morphological changes in gastrocnemius muscle cells were observed by hematoxylin and eosin (H&E) staining. ERK signaling pathway activation was detected through immunohistochemistry and Western blotting. The main morphological characteristics of injured muscle fibers around MTrPs include gathered circular or elliptical shapes of different sizes in the cross-section and continuous inflated and tapering fibers in the longitudinal section. After intramuscular injection of U0126 (ERK inhibitor), the mechanical pain threshold significantly increased. The reduction in mechanical hyperalgesia was accompanied by reduced ERK protein phosphorylation, myosin light chain kinase (MLCK) protein, p-MLC protein expression, and the cross-sectional area of skeletal muscle cells around MTrPs. An ERK inhibitor contributed to the attenuation of mechanical hyperalgesia in the rat myofascial pain model, and the increase in pain threshold may be related to MLCK downregulation and other related contraction-associated proteins by ERK.
Collapse
Affiliation(s)
- Yu-Chang Zhu
- Department of Anaesthesiology and Pain Clinic, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China.,Department of Anaesthesiology, Shangdong Provincial Maternal and Child Health Care Hospital, China
| | - Fei-Hong Jin
- Department of Anaesthesiology and Pain Clinic, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Ming-Yang Zhang
- Department of Anaesthesiology, Tengzhou Central People's Hospital, Tengzhou, Shandong, China
| | - Feng Qi
- Department of Anaesthesiology and Pain Clinic, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| |
Collapse
|
10
|
Łochyński D, Kaczmarek D, Grześkowiak M, Majerczak J, Podgórski T, Celichowski J. Motor Unit Force Potentiation and Calcium Handling Protein Concentration in Rat Fast Muscle After Resistance Training. Front Physiol 2021; 12:652299. [PMID: 34054571 PMCID: PMC8160384 DOI: 10.3389/fphys.2021.652299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/01/2021] [Indexed: 11/13/2022] Open
Abstract
Post-tetanic potentiation (PTP) of force depends on intramuscular Ca2+ levels and sensitivity and may be affected by fatigue. The aim of this study was to determine the ability of isolated fast fatigue-resistant (FR) and fast-fatigable (FF) motor units (MUs) to potentiate force evoked with single and 40-Hz electrical stimulation after 5 weeks of voluntary weight-lifting training. Tetanic contractions evoked by gradually increasing (10–150 Hz) stimulation frequency served as conditioning stimulation. Additionally, the concentration of myosin light chain kinase and proteins engaged in calcium handling was measured in rat fast medial gastrocnemius muscle. After the training, the potentiation of twitch force and peak rate of force development was increased in FF but not FR MUs. Force potentiation of 40-Hz tetanic contractions was increased in both fast MU types. After the training, the twitch duration of FR MUs was decreased, and FF MUs were less prone to high-frequency fatigue during conditioning stimulation. Muscle concentration of triadin was increased, whereas concentrations of ryanodine receptor 1, junctin, FKBP12, sarcoplasmic reticulum calcium ATPase 1, parvalbumin, myosin light chain kinase, and actomyosin adenosine triphosphatase content were not modified. After short-term resistance training, the twitch contraction time and twitch:tetanus force ratio of FR MUs are decreased, and PTP ability is not changed. However, PTP capacity is increased in response to submaximal activation. In FF MUs increase in PTP ability coexists with lesser fatigability. Further work is required to find out if the increase in triadin concentration has any impact on the observed contractile response.
Collapse
Affiliation(s)
- Dawid Łochyński
- Department of Neuromuscular Physiotherapy, Poznan University of Physical Education, Poznań, Poland
| | - Dominik Kaczmarek
- Department of Physiology and Biochemistry, Poznan University of Physical Education, Poznań, Poland
| | - Marcin Grześkowiak
- Department of Cardiological and Rheumatological Rehabilitation, Poznan University of Physical Education, Poznań, Poland
| | - Joanna Majerczak
- Department of Neurobiology, Poznan University of Physical Education, Poznań, Poland
| | - Tomasz Podgórski
- Department of Physiology and Biochemistry, Poznan University of Physical Education, Poznań, Poland
| | - Jan Celichowski
- Department of Neurobiology, Poznan University of Physical Education, Poznań, Poland
| |
Collapse
|
11
|
Shenkman BS, Tsaturyan AK, Vikhlyantsev IM, Kozlovskaya IB, Grigoriev AI. Molecular Mechanisms of Muscle Tone Impairment under Conditions of Real and Simulated Space Flight. Acta Naturae 2021; 13:85-97. [PMID: 34377559 PMCID: PMC8327152 DOI: 10.32607/actanaturae.10953] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 08/04/2020] [Indexed: 01/08/2023] Open
Abstract
Kozlovskaya et al. [1] and Grigoriev et al. [2] showed that enormous loss of muscle stiffness (atonia) develops in humans under true (space flight) and simulated microgravity conditions as early as after the first days of exposure. This phenomenon is attributed to the inactivation of slow motor units and called reflectory atonia. However, a lot of evidence indicating that even isolated muscle or a single fiber possesses substantial stiffness was published at the end of the 20th century. This intrinsic stiffness is determined by the active component, i.e. the ability to form actin-myosin cross-bridges during muscle stretch and contraction, as well as by cytoskeletal and extracellular matrix proteins, capable of resisting muscle stretch. The main facts on intrinsic muscle stiffness under conditions of gravitational unloading are considered in this review. The data obtained in studies of humans under dry immersion and rodent hindlimb suspension is analyzed. The results and hypotheses regarding reduced probability of cross-bridge formation in an atrophying muscle due to increased interfilament spacing are described. The evidence of cytoskeletal protein (titin, nebulin, etc.) degradation during gravitational unloading is also discussed. The possible mechanisms underlying structural changes in skeletal muscle collagen and its role in reducing intrinsic muscle stiffness are presented. The molecular mechanisms of changes in intrinsic stiffness during space flight and simulated microgravity are reviewed.
Collapse
Affiliation(s)
- B. S. Shenkman
- State Scientific Center of Russian Federation – Institute of Biomedical Problems, Moscow, 123007 Russia
| | - A. K. Tsaturyan
- Lomonosov Moscow State University Research Institute of Mechanics, Moscow, 119192 Russia
| | - I. M. Vikhlyantsev
- Institute of Experimental and Theoretical Biophysics, Moscow Region, Pushchino, 142290 Russia
| | - I. B. Kozlovskaya
- State Scientific Center of Russian Federation – Institute of Biomedical Problems, Moscow, 123007 Russia
| | - A. I. Grigoriev
- State Scientific Center of Russian Federation – Institute of Biomedical Problems, Moscow, 123007 Russia
| |
Collapse
|
12
|
Chen Z, Li B, Zhan RZ, Rao L, Bursac N. Exercise mimetics and JAK inhibition attenuate IFN-γ-induced wasting in engineered human skeletal muscle. SCIENCE ADVANCES 2021; 7:eabd9502. [PMID: 33523949 DOI: 10.1126/sciadv.abd9502] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 12/03/2020] [Indexed: 06/12/2023]
Abstract
Chronic inflammatory diseases often lead to muscle wasting and contractile deficit. While exercise can have anti-inflammatory effects, the underlying mechanisms remain unclear. Here, we used an in vitro tissue-engineered model of human skeletal muscle ("myobundle") to study effects of exercise-mimetic electrical stimulation (E-stim) on interferon-γ (IFN-γ)-induced muscle weakness. Chronic IFN-γ treatment of myobundles derived from multiple donors induced myofiber atrophy and contractile loss. E-stim altered the myobundle secretome, induced myofiber hypertrophy, and attenuated the IFN-γ-induced myobundle wasting and weakness, in part by down-regulating JAK (Janus kinase)/STAT1 (signal transducer and activator of transcription 1) signaling pathway amplified by IFN-γ. JAK/STAT inhibitors fully prevented IFN-γ-induced myopathy, confirming the critical roles of STAT1 activation in proinflammatory action of IFN-γ. Our results reveal a previously unknown mechanism of the cell-autonomous anti-inflammatory effects of muscle exercise and establish the utility of human myobundle platform for studies of inflammatory muscle disease and therapy.
Collapse
Affiliation(s)
- Zhaowei Chen
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Binjie Li
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Ren-Zhi Zhan
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Lingjun Rao
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Nenad Bursac
- Department of Biomedical Engineering, Duke University, Durham, NC, USA.
| |
Collapse
|
13
|
Yegorova S, Yegorov O, Ferreira LF. RNA-sequencing reveals transcriptional signature of pathological remodeling in the diaphragm of rats after myocardial infarction. Gene 2020; 770:145356. [PMID: 33333219 DOI: 10.1016/j.gene.2020.145356] [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: 07/03/2020] [Revised: 11/11/2020] [Accepted: 12/01/2020] [Indexed: 12/21/2022]
Abstract
The diaphragm is the main inspiratory muscle, and the chronic phase post-myocardial infarction (MI) is characterized by diaphragm morphological, contractile, and metabolic abnormalities. However, the mechanisms of diaphragm weakness are not fully understood. In the current study, we aimed to identify the transcriptome changes associated with diaphragm abnormalities in the chronic stage MI. We ligated the left coronary artery to cause MI in rats and performed RNA-sequencing (RNA-Seq) in diaphragm samples 16 weeks post-surgery. The sham group underwent thoracotomy and pericardiotomy but no artery ligation. We identified 112 differentially expressed genes (DEGs) out of a total of 9664 genes. Myocardial infarction upregulated and downregulated 42 and 70 genes, respectively. Analysis of DEGs in the framework of skeletal muscle-specific biological networks suggest remodeling in the neuromuscular junction, extracellular matrix, sarcomere, cytoskeleton, and changes in metabolism and iron homeostasis. Overall, the data are consistent with pathological remodeling of the diaphragm and reveal potential biological targets to prevent diaphragm weakness in the chronic stage MI.
Collapse
Affiliation(s)
- Svetlana Yegorova
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA.
| | - Oleg Yegorov
- Department of Neurosurgery, University of Florida, Gainesville, FL 32611, USA.
| | - Leonardo F Ferreira
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA.
| |
Collapse
|
14
|
Li X, Zhang D, Ren C, Bai Y, Ijaz M, Hou C, Chen L. Effects of protein posttranslational modifications on meat quality: A review. Compr Rev Food Sci Food Saf 2020; 20:289-331. [PMID: 33443799 DOI: 10.1111/1541-4337.12668] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/14/2020] [Accepted: 10/20/2020] [Indexed: 02/06/2023]
Abstract
Meat quality plays an important role in the purchase decision of consumers, affecting producers and retailers. The formation mechanisms determining meat quality are intricate, as several endogenous and exogenous factors contribute during antemortem and postmortem periods. Abundant research has been performed on meat quality; however, unexpected variation in meat quality remains an issue in the meat industry. Protein posttranslational modifications (PTMs) regulate structures and functions of proteins in living tissues, and recent reports confirmed their importance in meat quality. The objective of this review was to provide a summary of the research on the effects of PTMs on meat quality. The effects of four common PTMs, namely, protein phosphorylation, acetylation, S-nitrosylation, and ubiquitination, on meat quality were discussed, with emphasis on the effects of protein phosphorylation on meat tenderness, color, and water holding capacity. The mechanisms and factors that may affect the function of protein phosphorylation are also discussed. The current research confirms that meat quality traits are regulated by multiple PTMs. Cross talk between different PTMs and interactions of PTMs with postmortem biochemical processes need to be explored to improve our understanding on factors affecting meat quality.
Collapse
Affiliation(s)
- Xin Li
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Dequan Zhang
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Chi Ren
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yuqiang Bai
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Muawuz Ijaz
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Chengli Hou
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Li Chen
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| |
Collapse
|
15
|
Yawei Z, Xiuyun G, Jamali MA, Rui F, Zengqi P. Influence of l-histidine and l-lysine on the phosphorylation of myofibrillar and sarcoplasmic proteins from chicken breast in response to salting. Lebensm Wiss Technol 2020. [DOI: 10.1016/j.lwt.2020.110125] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
16
|
Diurnal Differences in Human Muscle Isometric Force In Vivo Are Associated with Differential Phosphorylation of Sarcomeric M-Band Proteins. Proteomes 2020; 8:proteomes8030022. [PMID: 32859009 PMCID: PMC7565642 DOI: 10.3390/proteomes8030022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/06/2020] [Accepted: 08/25/2020] [Indexed: 12/25/2022] Open
Abstract
We investigated whether diurnal differences in muscle force output are associated with the post-translational state of muscle proteins. Ten physically active men (mean ± SD; age 26.7 ± 3.7 y) performed experimental sessions in the morning (08:00 h) and evening (17:00 h), which were counterbalanced in order of administration and separated by at least 72 h. Knee extensor maximal voluntary isometric contraction (MVIC) force and peak rate of force development (RFD) were measured, and samples of vastus lateralis were collected immediately after exercise. MVIC force was greater in the evening (mean difference of 67 N, 10.2%; p < 0.05). Two-dimensional (2D) gel analysis encompassed 122 proteoforms and discovered 6 significant (p < 0.05; false discovery rate [FDR] = 10%) diurnal differences. Phosphopeptide analysis identified 1693 phosphopeptides and detected 140 phosphopeptides from 104 proteins that were more (p < 0.05, FDR = 22%) phosphorylated in the morning. Myomesin 2, muscle creatine kinase, and the C-terminus of titin exhibited the most robust (FDR < 10%) diurnal differences. Exercise in the morning, compared to the evening, coincided with a greater phosphorylation of M-band-associated proteins in human muscle. These protein modifications may alter the M-band structure and disrupt force transmission, thus potentially explaining the lower force output in the morning.
Collapse
|
17
|
Blazevich AJ, Babault N. Post-activation Potentiation Versus Post-activation Performance Enhancement in Humans: Historical Perspective, Underlying Mechanisms, and Current Issues. Front Physiol 2019; 10:1359. [PMID: 31736781 PMCID: PMC6838751 DOI: 10.3389/fphys.2019.01359] [Citation(s) in RCA: 217] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 10/14/2019] [Indexed: 12/31/2022] Open
Abstract
Post-activation potentiation (PAP) is a well-described phenomenon with a short half-life (~28 s) that enhances muscle force production at submaximal levels of calcium saturation (i.e., submaximal levels of muscle activation). It has been largely explained by an increased myosin light chain phosphorylation occurring in type II muscle fibers, and its effects have been quantified in humans by measuring muscle twitch force responses to a bout of muscular activity. However, enhancements in (sometimes maximal) voluntary force production detected several minutes after high-intensity muscle contractions are also observed, which are also most prominent in muscles with a high proportion of type II fibers. This effect has been considered to reflect PAP. Nonetheless, the time course of myosin light chain phosphorylation (underpinning “classic” PAP) rarely matches that of voluntary force enhancement and, unlike PAP, changes in muscle temperature, muscle/cellular water content, and muscle activation may at least partly underpin voluntary force enhancement; this enhancement has thus recently been called post-activation performance enhancement (PAPE) to distinguish it from “classical” PAP. In fact, since PAPE is often undetectable at time points where PAP is maximal (or substantial), some researchers have questioned whether PAP contributes to PAPE under most conditions in vivo in humans. Equally, minimal evidence has been presented that PAP is of significant practical importance in cases where multiple physiological processes have already been upregulated by a preceding, comprehensive, active muscle warm-up. Given that confusion exists with respect to the mechanisms leading to acute enhancement of both electrically evoked (twitch force; PAP) and voluntary (PAPE) muscle function in humans after acute muscle activity, the first purpose of the present narrative review is to recount the history of PAP/PAPE research to locate definitions and determine whether they are the same phenomena. To further investigate the possibility of these phenomena being distinct as well as to better understand their potential functional benefits, possible mechanisms underpinning their effects will be examined in detail. Finally, research design issues will be addressed which might contribute to confusion relating to PAP/PAPE effects, before the contexts in which these phenomena may (or may not) benefit voluntary muscle function are considered.
Collapse
Affiliation(s)
- Anthony J Blazevich
- School of Medical and Health Science, Centre for Exercise and Sports Science Research (CESSR), Edith Cowan University, Joondalup, WA, Australia
| | - Nicolas Babault
- Faculty of Sport Sciences, French National Institute of Health and Medical Research (INSERM), Unit 1093 Cognition, Action and Sensorimotor Plasticity, Centre for Performance Expertise, University of Burgundy and Franche-Comté, Dijon, France
| |
Collapse
|
18
|
Mato A, Rodríguez-Vázquez R, López-Pedrouso M, Bravo S, Franco D, Zapata C. The first evidence of global meat phosphoproteome changes in response to pre-slaughter stress. BMC Genomics 2019; 20:590. [PMID: 31315554 PMCID: PMC6637562 DOI: 10.1186/s12864-019-5943-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 06/27/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Pre-slaughter stress (PSS) impairs animal welfare and meat quality. Dark, firm and dry (DFD) are terms used to designate poor quality meats induced by PSS. Protein phosphorylation can be a potentially significant mechanism to explain rapid and multiple physiological and biochemical changes linked to PSS-dependent muscle-to-meat conversion. However, the role of reversible phosphorylation in the response to PSS is still little known. In this study, we report a comparative phosphoproteomic analysis of DFD and normal meats at 24 h post-mortem from the longissimus thoracis (LT) bovine muscle of male calves of the Rubia Gallega breed. For this purpose, two-dimensional gel electrophoresis (2-DE), in-gel multiplex identification of phosphoproteins with PRO-Q Diamond phosphoprotein-specific stain, tandem (MALDI-TOF/TOF) mass spectrometry (MS), novel quantitative phosphoproteomic statistics and bioinformatic tools were used. RESULTS Noticeable and statistically significant differences in the extent of protein phosphorylation were detected between sample groups at the qualitative and quantitative levels. Overall phosphorylation rates across significantly changed phosphoproteins were about three times higher in DFD than in normal meat. Significantly changed phosphoproteins involved a variable number of isoforms of 13 myofibrillar and sarcoplasmic nonredundant proteins. However, fast skeletal myosin light chain 2 followed by troponin T, F-actin-capping and small heat shock proteins showed the greatest phosphorylation change, and therefore they were the most important phosphoproteins underlying LT muscle conversion to DFD meat in the Rubia Gallega breed. CONCLUSIONS This is the first study reporting global meat phosphoproteome changes in response to PSS. The results show that reversible phosphorylation is a relevant mechanism underlying PSS response and downstream effects on meat quality. This research opens up novel horizons to unravel the complex molecular puzzle underlying muscle-to-meat conversion in response to PSS.
Collapse
Affiliation(s)
- Ariadna Mato
- Department of Zoology, Genetics and Physical Anthropology, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Raquel Rodríguez-Vázquez
- Department of Zoology, Genetics and Physical Anthropology, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - María López-Pedrouso
- Department of Zoology, Genetics and Physical Anthropology, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Susana Bravo
- Proteomics Laboratory, CHUS, 15782 Santiago de Compostela, Spain
| | - Daniel Franco
- Meat Technology Center of Galicia, 32900 Ourense, Spain
| | - Carlos Zapata
- Department of Zoology, Genetics and Physical Anthropology, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| |
Collapse
|
19
|
Dillon EL, Soman KV, Wiktorowicz JE, Sur R, Jupiter D, Danesi CP, Randolph KM, Gilkison CR, Durham WJ, Urban RJ, Sheffield-Moore M. Proteomic investigation of human skeletal muscle before and after 70 days of head down bed rest with or without exercise and testosterone countermeasures. PLoS One 2019; 14:e0217690. [PMID: 31194764 PMCID: PMC6563988 DOI: 10.1371/journal.pone.0217690] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 05/09/2019] [Indexed: 11/18/2022] Open
Abstract
Introduction Long-term head-down bed rest (HDBR) results in musculoskeletal losses similar to those observed during long-term space flight. Agents such as testosterone, in addition to regular exercise, are effective countermeasures for reducing loss of skeletal muscle mass and function. Objective We investigated the skeletal muscle proteome of healthy men in response to long term HDBR alone (CON) and to HDBR with exercise (PEX) or exercise plus testosterone (TEX) countermeasures. Method Biopsies were performed on the vastus lateralis before (pre) HDBR and on HDBR days 32 (mid) and 64 (post). Extracted proteins from these skeletal muscle biopsies were subjected to 2-dimensional gel electrophoresis (2DE), stained for phosphoproteins (Pro-Q Diamond dye) and total proteins (Sypro Ruby dye). Proteins showing significant fold differences (t-test p ≤ 0.05) in abundance or phosphorylation state at mid or post were identified by mass spectroscopy (MS). Results From a total of 932 protein spots, 130 spots were identified as potentially altered in terms of total protein or phosphoprotein levels due to HDBR and/or countermeasures, and 59 unique molecules emerged from MS analysis. Top canonical pathways identified through IPA included calcium signaling, actin cytoskeleton signaling, integrin linked kinase (ILK) signaling, and epithelial adherens junction signaling. Data from the pre-HDBR proteome supported the potential for predicting physiological post-HDBR responses such as the individual’s potential for loss vs. maintenance of muscle mass and strength. Conclusions HDBR resulted in alterations to skeletal muscle abundances and phosphorylation of several structural and metabolic proteins. Inclusion of exercise alone or in combination with testosterone treatment modulated the proteomic responses towards cellular reorganization and hypertrophy, respectively. Finally, the baseline proteome may aid in the development of personalized countermeasures to mitigate health risks in astronauts as related to loss of muscle mass and function.
Collapse
Affiliation(s)
- E. Lichar Dillon
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX, United States of America
| | - Kizhake V. Soman
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, United States of America
| | - John E. Wiktorowicz
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, United States of America
| | - Ria Sur
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, United States of America
| | - Daniel Jupiter
- Department of Preventive Medicine and Community Health, The University of Texas Medical Branch, Galveston, TX, United States of America
| | - Christopher P. Danesi
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX, United States of America
| | - Kathleen M. Randolph
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX, United States of America
| | - Charles R. Gilkison
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX, United States of America
| | - William J. Durham
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX, United States of America
| | - Randall J. Urban
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX, United States of America
| | - Melinda Sheffield-Moore
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX, United States of America
- Department of Health and Kinesiology, Texas A&M University, College Station, TX, United States of America
- * E-mail:
| |
Collapse
|
20
|
Kazmierczak K, Liang J, Yuan CC, Yadav S, Sitbon YH, Walz K, Ma W, Irving TC, Cheah JX, Gomes AV, Szczesna-Cordary D. Slow-twitch skeletal muscle defects accompany cardiac dysfunction in transgenic mice with a mutation in the myosin regulatory light chain. FASEB J 2019; 33:3152-3166. [PMID: 30365366 PMCID: PMC6404564 DOI: 10.1096/fj.201801402r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 10/01/2018] [Indexed: 01/06/2023]
Abstract
Myosin light chain 2 ( MYL2) gene encodes the myosin regulatory light chain (RLC) simultaneously in heart ventricles and in slow-twitch skeletal muscle. Using transgenic mice with cardiac-specific expression of the human R58Q-RLC mutant, we sought to determine whether the hypertrophic cardiomyopathy phenotype observed in papillary muscles (PMs) of R58Q mice is also manifested in slow-twitch soleus (SOL) muscles. Skinned SOL muscles and ventricular PMs of R58Q animals exhibited lower contractile force that was not observed in the fast-twitch extensor digitorum longus muscles of R58Q vs. wild-type-RLC mice, but mutant animals did not display gross muscle weakness in vivo. Consistent with SOL muscle abnormalities in R58Q vs. wild-type mice, myosin ATPase staining revealed a decreased proportion of fiber type I/type II only in SOL muscles but not in the extensor digitorum longus muscles. The similarities between SOL muscles and PMs of R58Q mice were further supported by quantitative proteomics. Differential regulation of proteins involved in energy metabolism, cell-cell interactions, and protein-protein signaling was concurrently observed in the hearts and SOL muscles of R58Q mice. In summary, even though R58Q expression was restricted to the heart of mice, functional similarities were clearly observed between the hearts and slow-twitch skeletal muscle, suggesting that MYL2 mutated models of hypertrophic cardiomyopathy may be useful research tools to study the molecular, structural, and energetic mechanisms of cardioskeletal myopathy associated with myosin RLC.-Kazmierczak, K., Liang, J., Yuan, C.-C., Yadav, S., Sitbon, Y. H., Walz, K., Ma, W., Irving, T. C., Cheah, J. X., Gomes, A. V., Szczesna-Cordary, D. Slow-twitch skeletal muscle defects accompany cardiac dysfunction in transgenic mice with a mutation in the myosin regulatory light chain.
Collapse
Affiliation(s)
- Katarzyna Kazmierczak
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Jingsheng Liang
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Chen-Ching Yuan
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Sunil Yadav
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Yoel H. Sitbon
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Katherina Walz
- Dr. John T. Macdonald Foundation Department of Human Genetics, John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Weikang Ma
- Department of Biological Sciences, Illinois Institute of Technology, Chicago, Illinois, USA
| | - Thomas C. Irving
- Department of Biological Sciences, Illinois Institute of Technology, Chicago, Illinois, USA
| | - Jenice X. Cheah
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, California, USA
| | - Aldrin V. Gomes
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, California, USA
| | - Danuta Szczesna-Cordary
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
| |
Collapse
|
21
|
Cao L, Hou C, Shen Q, Zhang D, Wang Z. Phosphorylation of myosin regulatory light chain affects actomyosin dissociation and myosin degradation. Int J Food Sci Technol 2019. [DOI: 10.1111/ijfs.14138] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Lichuang Cao
- Institute of Food Science and Technology Chinese Academy of Agricultural Sciences/Key Laboratory of Agro‐Products Processing Ministry of Agriculture and Rural Affairs Beijing 100193 China
| | - Chengli Hou
- Institute of Food Science and Technology Chinese Academy of Agricultural Sciences/Key Laboratory of Agro‐Products Processing Ministry of Agriculture and Rural Affairs Beijing 100193 China
| | - Qingwu Shen
- College of Food Science and Technology Hunan Agricultural University Changsha Hunan 410128 China
| | - Dequan Zhang
- Institute of Food Science and Technology Chinese Academy of Agricultural Sciences/Key Laboratory of Agro‐Products Processing Ministry of Agriculture and Rural Affairs Beijing 100193 China
| | - Zhenyu Wang
- Institute of Food Science and Technology Chinese Academy of Agricultural Sciences/Key Laboratory of Agro‐Products Processing Ministry of Agriculture and Rural Affairs Beijing 100193 China
| |
Collapse
|
22
|
Chorley A, Lamb KL. The Effects of a Cycling Warm-up Including High-Intensity Heavy-Resistance Conditioning Contractions on Subsequent 4-km Time Trial Performance. J Strength Cond Res 2019; 33:57-65. [DOI: 10.1519/jsc.0000000000001908] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
23
|
Mamchur A, Leman E, Salah S, Avivi A, Shams I, Manov I. Adipose-Derived Stem Cells of Blind Mole Rat Spalax Exhibit Reduced Homing Ability: Molecular Mechanisms and Potential Role in Cancer Suppression. Stem Cells 2018; 36:1630-1642. [PMID: 30004601 DOI: 10.1002/stem.2884] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 06/17/2018] [Accepted: 06/05/2018] [Indexed: 12/18/2022]
Abstract
Adipose-derived stem cells (ADSCs) are recruited by cancer cells from the adjacent tissue, and they become an integral part of the tumor microenvironment. Here, we report that ADSCs from the long-living, tumor-resistant blind mole rat, Spalax, have a low ability to migrate toward cancer cells compared with cells from its Rattus counterpart. Tracking 5-ethynyl-2'-deoxyuridine (EdU)-labeled ADSCs, introduced to tumor-bearing nude mice, toward the xenografts, we found that rat ADSCs intensively migrated and penetrated the tumors, whereas only a few Spalax ADSCs reached the tumors. Moreover, rat ADSCs, but not Spalax ADSCs, acquired endothelial-like phenotype and incorporated in the intratumoral reticular structure resembling a vasculature. Likewise, endothelial-like cells differentiated from Spalax and rat ADSCs could form capillary-like structures; however, the tube densities were higher in rat-derived cells. Using time-lapse microscopy, in vitro wound-healing, and transwell migration assays, we demonstrated the impaired motility and low polarization ability of Spalax ADSCs. To assess whether the phosphorylated status of myosin light chain (MLC) is involved in the decreased motility of Spalax ADSCs, we inhibited MLC phosphorylation by blocking of Rho-kinase (ROCK). Inhibition of ROCK resulted in the suppression of MLC phosphorylation, acquisition of actin polarization, and activation of motility and migration of Spalax ADSCs. We propose that reduced ADSCs migration to cancer and poor intratumoral angiogenesis play a role in Spalax's cancer resistance. Learning more about the molecular strategy of noncancerous cells in Spalax to resist oncogenic stimuli and maintain a nonpermissive tumor milieu may lead us to developing new cancer-preventive strategy in humans. Stem Cells 2018;36:1630-1642.
Collapse
Affiliation(s)
| | - Eva Leman
- Faculty of Natural Sciences, Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Safaa Salah
- Faculty of Natural Sciences, Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Aaron Avivi
- Institute of Evolution, University of Haifa, Haifa, Israel
| | - Imad Shams
- Institute of Evolution, University of Haifa, Haifa, Israel.,Faculty of Natural Sciences, Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Irena Manov
- Institute of Evolution, University of Haifa, Haifa, Israel
| |
Collapse
|
24
|
Morris SR, Gittings W, Vandenboom R. Epinephrine augments posttetanic potentiation in mouse skeletal muscle with and without myosin phosphorylation. Physiol Rep 2018; 6:e13690. [PMID: 29718592 PMCID: PMC5931225 DOI: 10.14814/phy2.13690] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/19/2018] [Accepted: 03/20/2018] [Indexed: 11/24/2022] Open
Abstract
Sympathetic tone may influence force potentiation, that is, the stimulation-induced increase in skeletal muscle mechanical function associated with myosin phosphorylation, although the mechanism for this effect remains unknown. The purpose of this study was to examine the influence of epinephrine on concentric twitch force potentiation of wild-type and skeletal myosin light-chain kinase devoid mouse muscle (skMLCK-/- ). To this end, concentric twitch force was assessed before and after a potentiating stimulus (PS) to determine the peak and the duration of potentiation in the absence (-EPI) and presence (+EPI) of 1 μmol/L epinephrine in both genotypes. Twitch force of wild-type and skMLCK-/- muscles was increased by up to 31 and 35% and 18 and 23% in the -EPI and EPI conditions, respectively (all data n = 8, P < 0.05). In wild-type muscles, the PS increased RLC phosphorylation from 0.14 ± 0.05 (rest) to 0.66 ± 0.08 mol phos mol RLC; by 480 sec RLC phosphorylation had returned to baseline (all data n = 4 each time point, P < 0.05). Neither resting nor peak levels of RLC phosphorylation were altered by +EPI, although the duration of RLC phosphorylation was prolonged. In skMLCK-/- muscles, RLC phosphorylation was not elevated above constituent levels by stimulation in either the -EPI or +EPI condition. Thus, given the similarity in potentiation responses between genotypes our data suggest that the influence of epinephrine on potentiation was independent of skMLCK catalyzed phosphorylation of the RLC, although the clinical significance of this pathway for skeletal muscle function remains to be identified.
Collapse
Affiliation(s)
| | - William Gittings
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
| | - Rene Vandenboom
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
| |
Collapse
|
25
|
Yalcin S, Şahin K, Tuzcu M, Bilgen G, Özkan S, Izzetoğlu GT, Işik R. Muscle structure and gene expression in pectoralis major muscle in response to deep pectoral myopathy induction in fast- and slow-growing commercial broilers. Br Poult Sci 2018; 60:195-201. [PMID: 29355388 DOI: 10.1080/00071668.2018.1430351] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
1. The objective of this study was to determine muscle structure and gene expression in pectoralis major (p. major) muscle of broilers in response to deep pectoral myopathy (DPM) induction. 2. A total of 160 chickens from slow- and fast-growing broilers were raised under same conditions. Half of the broilers from each strain were encouraged to wing flap when they reached 2800 g body weight. Pectoralis minor (p. minor) muscle of the broilers was inspected for the occurrence of DPM and p. major samples were collected from broilers with or without DPM. The muscle fibre area and number, capillary number and the signalling pathways of vascular development (vascular endothelial growth factor A, VEGFA) and muscle contraction regulation (actin alpha 1, ACTA1; myosin light chain kinase 2, MYLK2 and ATPase Ca+2 transporting gene 1, ATP2A1) were studied in p. major muscle. 3. DPM induction increased fibre area of p. major muscle with a greater rate in the slow-growing strain compared with fast-growing line. Although the capillary number was higher in slow-growing compared with fast-growing broilers, in the case of DPM induction, the number of capillaries was similar between strains. 4. Expression of VEGFA, MYLK2 and ATP2A1 was greater in slow- than in fast-growing broilers. DPM induction increased expression of ACTA1, VEGFA and ATP2A1 in p. major muscle of broilers from both strains; however, MYLK2 expression was downregulated. 5. Changes in capillary density and expression of VEGFA found in the p. major muscle of broilers with DPM suggest increased blood flow to increase oxygen availability. The upregulation of ATP2A1 by DPM induction could be attributable to alterations in calcium ion transportation from the cytoplasm into the sarcoplasmic reticulum. 6. The results are evidence of changes in muscle structure and gene expression pathways in p. major muscle of broilers with DPM.
Collapse
Affiliation(s)
- S Yalcin
- a Faculty of Agriculture, Department of Animal Science , Ege University , İzmir , Turkey
| | - K Şahin
- b Veterinary Faculty, Department of Animal Nutrition , Fırat University , Elazig , Turkey
| | - M Tuzcu
- c Faculty of Science, Department of Biology , Fırat University , Elazig , Turkey
| | - G Bilgen
- a Faculty of Agriculture, Department of Animal Science , Ege University , İzmir , Turkey
| | - S Özkan
- a Faculty of Agriculture, Department of Animal Science , Ege University , İzmir , Turkey
| | - G T Izzetoğlu
- d Faculty of Science, Department of Biology , Ege University , İzmir , Turkey
| | - R Işik
- e Faculty of Agriculture, Department of Agricultural Biotechnology , Namık Kemal University , Tekirdağ , Turkey
| |
Collapse
|
26
|
Bunda J, Gittings W, Vandenboom R. Myosin phosphorylation improves contractile economy of mouse fast skeletal muscle during staircase potentiation. ACTA ACUST UNITED AC 2018; 221:jeb.167718. [PMID: 29361581 DOI: 10.1242/jeb.167718] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 12/31/2017] [Indexed: 01/12/2023]
Abstract
Phosphorylation of the myosin regulatory light chain (RLC) by skeletal myosin light chain kinase (skMLCK) potentiates rodent fast twitch muscle but is an ATP-requiring process. Our objective was to investigate the effect of skMLCK-catalyzed RLC phosphorylation on the energetic cost of contraction and the contractile economy (ratio of mechanical output to metabolic input) of mouse fast twitch muscle in vitro (25°C). To this end, extensor digitorum longus (EDL) muscles from wild-type (WT) and from skMLCK-devoid (skMLCK-/-) mice were subjected to repetitive low-frequency stimulation (10 Hz for 15 s) to produce staircase potentiation of isometric twitch force, after which muscles were quick frozen for determination of high-energy phosphate consumption (HEPC). During stimulation, WT muscles displayed significant potentiation of isometric twitch force while skMLCK-/- muscles did not (i.e. 23% versus 5% change, respectively). Consistent with this, RLC phosphorylation was increased ∼3.5-fold from the unstimulated control value in WT but not in skMLCK-/- muscles. Despite these differences, the HEPC of WT muscles was not greater than that of skMLCK-/- muscles. As a result of the increased contractile output relative to HEPC, the calculated contractile economy of WT muscles was greater than that of skMLCK-/- muscles. Thus, our results suggest that skMLCK-catalyzed phosphorylation of the myosin RLC increases the contractile economy of WT mouse EDL muscle compared with skMLCK-/- muscles without RLC phosphorylation.
Collapse
Affiliation(s)
- Jordan Bunda
- Centre for Bone and Muscle Health, Faculty of Applied Health Sciences, Brock University, St Catharines, ON L2S 3A1, Canada
| | - William Gittings
- Centre for Bone and Muscle Health, Faculty of Applied Health Sciences, Brock University, St Catharines, ON L2S 3A1, Canada
| | - Rene Vandenboom
- Centre for Bone and Muscle Health, Faculty of Applied Health Sciences, Brock University, St Catharines, ON L2S 3A1, Canada
| |
Collapse
|
27
|
Gao N, Tsai MH, Chang AN, He W, Chen CP, Zhu M, Kamm KE, Stull JT. Physiological vs. pharmacological signalling to myosin phosphorylation in airway smooth muscle. J Physiol 2017; 595:6231-6247. [PMID: 28749013 PMCID: PMC5621497 DOI: 10.1113/jp274715] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/25/2017] [Indexed: 01/05/2023] Open
Abstract
KEY POINTS Smooth muscle myosin regulatory light chain (RLC) is phosphorylated by Ca2+ /calmodulin-dependent myosin light chain kinase and dephosphorylated by myosin light chain phosphatase (MLCP). Tracheal smooth muscle contains significant amounts of myosin binding subunit 85 (MBS85), another myosin phosphatase targeting subunit (MYPT) family member, in addition to MLCP regulatory subunit MYPT1. Concentration/temporal responses to carbachol demonstrated similar sensitivities for bovine tracheal force development and phosphorylation of RLC, MYPT1, MBS85 and paxillin. Electrical field stimulation releases ACh from nerves to increase RLC phosphorylation but not MYPT1 or MBS85 phosphorylation. Thus, nerve-mediated muscarinic responses in signalling modules acting on RLC phosphorylation are different from pharmacological responses with bath added agonist. The conditional knockout of MYPT1 or the knock-in mutation T853A in mice had no effect on muscarinic force responses in isolated tracheal tissues. MLCP activity may arise from functionally shared roles between MYPT1 and MBS85, resulting in minimal effects of MYPT1 knockout on contraction. ABSTRACT Ca2+ /calmodulin activation of myosin light chain kinase (MLCK) initiates myosin regulatory light chain (RLC) phosphorylation for smooth muscle contraction with subsequent dephosphorylation for relaxation by myosin light chain phosphatase (MLCP) containing regulatory (MYPT1) and catalytic (PP1cδ) subunits. RLC phosphorylation-dependent force development is regulated by distinct signalling modules involving protein phosphorylations. We investigated responses to cholinergic agonist treatment vs. neurostimulation by electric field stimulation (EFS) in bovine tracheal smooth muscle. Concentration/temporal responses to carbachol demonstrated tight coupling between force development and RLC phosphorylation but sensitivity differences in MLCK, MYPT1 T853, MYPT1 T696, myosin binding subunit 85 (MBS85), paxillin and CPI-17 (PKC-potentiated protein phosphatase 1 inhibitor protein of 17 kDa) phosphorylations. EFS increased force and phosphorylation of RLC, CPI-17 and MLCK. In the presence of the cholinesterase inhibitor neostigmine, EFS led to an additional increase in phosphorylation of MYPT1 T853, MYPT1 T696, MBS85 and paxillin. Thus, there were distinct pharmacological vs. physiological responses in signalling modules acting on RLC phosphorylation and force responses, probably related to degenerate G protein signalling networks. Studies with genetically modified mice were performed. Expression of another MYPT1 family member, MBS85, was enriched in mouse, as well as bovine tracheal smooth muscle. Carbachol concentration/temporal-force responses were similar in trachea from MYPT1SM+/+ , MYPT1SM-/- and the knock-in mutant mice containing nonphosphorylatable MYPT1 T853A with no differences in RLC phosphorylation. Thus, MYPT1 T853 phosphorylation was not necessary for regulation of RLC phosphorylation in tonic airway smooth muscle. Furthermore, MLCP activity may arise from functionally shared roles between MYPT1 and MBS85, resulting in minimal effects of MYPT1 knockout on contraction.
Collapse
Affiliation(s)
- Ning Gao
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ming-Ho Tsai
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Present address: Graduate Institute of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Rd, San Ming District, Kaohsiung, Taiwan
| | - Audrey N Chang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Weiqi He
- Model Animal Research Center and MOE Key Laboratory of Model Animal for Disease Study, Nanjing University, Nanjing, China.,Present address: Cambridge-Suda (CAM-SU) Genomic Resource Center, Soochow University, Suzhou, China
| | - Cai-Ping Chen
- Model Animal Research Center and MOE Key Laboratory of Model Animal for Disease Study, Nanjing University, Nanjing, China.,Present address: Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease, China Pharmaceutical University, Nanjing, PR China
| | - Minsheng Zhu
- Model Animal Research Center and MOE Key Laboratory of Model Animal for Disease Study, Nanjing University, Nanjing, China
| | - Kristine E Kamm
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - James T Stull
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| |
Collapse
|
28
|
Gao X, Li X, Li Z, Du M, Zhang D. Dephosphorylation of myosin regulatory light chain modulates actin-myosin interaction adverse to meat tenderness. Int J Food Sci Technol 2017. [DOI: 10.1111/ijfs.13343] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xing Gao
- Institute of Food Science and Technology; Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing; Ministry of Agriculture; Beijing 100193 China
- College of Food Science and Technology; Northwest Agricultural & Forestry University; Yangling Shaanxi 712100 China
| | - Xin Li
- Institute of Food Science and Technology; Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing; Ministry of Agriculture; Beijing 100193 China
| | - Zheng Li
- Institute of Food Science and Technology; Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing; Ministry of Agriculture; Beijing 100193 China
| | - Manting Du
- Institute of Food Science and Technology; Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing; Ministry of Agriculture; Beijing 100193 China
| | - Dequan Zhang
- Institute of Food Science and Technology; Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing; Ministry of Agriculture; Beijing 100193 China
| |
Collapse
|
29
|
Gittings W, Bunda J, Vandenboom R. Shortening speed dependent force potentiation is attenuated but not eliminated in skeletal muscles without myosin phosphorylation. J Muscle Res Cell Motil 2017; 38:157-162. [PMID: 28251466 DOI: 10.1007/s10974-017-9465-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 02/02/2017] [Indexed: 01/08/2023]
Abstract
We investigated the influence of shortening speed on concentric force potentiation at different frequencies in muscles devoid of skeletal myosin light chain kinase (skMLCK-/-) and unable to phosphorylate myosin. EDL muscles from skMLCK-/- mice were activated in vitro (25 °C) across a range of stimulation frequencies (10-100 Hz) during shortening ramps at 0.10, 0.30, or 0.50 of maximum shortening velocity (Vmax) before and after a potentiating stimulus (PS). When collapsed across all frequencies, the PS increased relative (post/pre) concentric force to 1.27 ± 0.02 and 1.17 ± 0.02 of pre-PS values at 0.50 and 0.30 Vmax, respectively (n = 4, P < 0.05 for all speeds). In addition, potentiation was significantly greater at low and intermediate-than at high stimulus frequencies at both speeds. In contrast, during shortening at 0.10 Vmax, a posttetanic depression was observed as mean concentric forces were reduced to 0.85 ± 0.02 of pre-PS values. Thus, although reduced compared to published values for wildtype muscles (Gittings et al., J Muscle Res Cell Motil 33:359-368, 2012), skMLCK-/- muscles displayed a speed dependent potentiation of concentric force during moderate and fast shortening speed at all frequencies tested. Our data support the presence of a myosin phosphorylation-independent mechanism(s) for concentric force potentiation at moderate speeds of shortening, and also suggests that myosin phosphorylation may be necessary to prevent the concentric force depression that may be present at slow speeds of shortening. Although additive in nature, further work is needed to parse out the relative influence of myosin phosphorylation-independent and dependent potentiation mechanisms on wildtype contractile function during dynamic conditions.
Collapse
Affiliation(s)
- William Gittings
- Centre for Bone and Muscle Health, Brock University, 274 Walker Complex, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada
| | - Jordan Bunda
- Centre for Bone and Muscle Health, Brock University, 274 Walker Complex, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada
| | - Rene Vandenboom
- Centre for Bone and Muscle Health, Brock University, 274 Walker Complex, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada.
| |
Collapse
|
30
|
Differences in Beef Quality between Angus (Bos taurus taurus) and Nellore (Bos taurus indicus) Cattle through a Proteomic and Phosphoproteomic Approach. PLoS One 2017; 12:e0170294. [PMID: 28103301 PMCID: PMC5245812 DOI: 10.1371/journal.pone.0170294] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 01/03/2017] [Indexed: 12/19/2022] Open
Abstract
Proteins are the major constituents of muscle and are key molecules regulating the metabolic changes during conversion of muscle to meat. Brazil is one of the largest exporters of beef and most Brazilian cattle are composed by zebu (Nellore) genotype. Bos indicus beef is generally leaner and tougher than Bos taurus such as Angus. The aim of this study was to compare the muscle proteomic and phosphoproteomic profile of Angus and Nellore. Seven animals of each breed previously subjected the same growth management were confined for 84 days. Proteins were extracted from Longissimus lumborum samples collected immediately after slaughter and separated by two-dimensional electrophoresis. Pro-Q Diamond stain was used in phosphoproteomics. Proteins identification was performed using matrix assisted laser desorption/ionization time-of-flight mass spectrometry. Tropomyosin alpha-1 chain, troponin-T, myosin light chain-1 fragment, cytoplasmic malate dehydrogenase, alpha-enolase and 78 kDa glucose-regulated protein were more abundant in Nellore, while myosin light chain 3, prohibitin, mitochondrial stress-70 protein and heat shock 70 kDa protein 6 were more abundant in Angus (P<0.05). Nellore had higher phosphorylation of myosin regulatory light chain-2, alpha actin-1, triosephosphate isomerase and 14-3-3 protein epsilon. However, Angus had greater phosphorylation of phosphoglucomutase-1 and troponin-T (P<0.05). Therefore, proteins involved in contraction and muscle organization, myofilaments expressed in fast or slow-twitch fibers and heat shock proteins localized in mitochondria or sarcoplasmic reticulum and involved in cell flux of calcium and apoptosis might be associated with differences in beef quality between Angus and Nellore. Furthermore, prohibitin appears to be a potential biomarker of intramuscular fat in cattle. Additionally, differences in phosphorylation of myofilaments and glycolytic enzymes could be involved with differences in muscle contraction force, susceptibility to calpain, apoptosis and postmortem glycolysis, which might also be related to differences in beef quality among Angus and Nellore.
Collapse
|
31
|
Vandenboom R. Modulation of Skeletal Muscle Contraction by Myosin Phosphorylation. Compr Physiol 2016; 7:171-212. [PMID: 28135003 DOI: 10.1002/cphy.c150044] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The striated muscle sarcomere is a highly organized and complex enzymatic and structural organelle. Evolutionary pressures have played a vital role in determining the structure-function relationship of each protein within the sarcomere. A key part of this multimeric assembly is the light chain-binding domain (LCBD) of the myosin II motor molecule. This elongated "beam" functions as a biological lever, amplifying small interdomain movements within the myosin head into piconewton forces and nanometer displacements against the thin filament during the cross-bridge cycle. The LCBD contains two subunits known as the essential and regulatory myosin light chains (ELC and RLC, respectively). Isoformic differences in these respective species provide molecular diversity and, in addition, sites for phosphorylation of serine residues, a highly conserved feature of striated muscle systems. Work on permeabilized skeletal fibers and thick filament systems shows that the skeletal myosin light chain kinase catalyzed phosphorylation of the RLC alters the "interacting head motif" of myosin motor heads on the thick filament surface, with myriad consequences for muscle biology. At rest, structure-function changes may upregulate actomyosin ATPase activity of phosphorylated cross-bridges. During activation, these same changes may increase the Ca2+ sensitivity of force development to enhance force, work, and power output, outcomes known as "potentiation." Thus, although other mechanisms may contribute, RLC phosphorylation may represent a form of thick filament activation that provides a "molecular memory" of contraction. The clinical significance of these RLC phosphorylation mediated alterations to contractile performance of various striated muscle systems are just beginning to be understood. © 2017 American Physiological Society. Compr Physiol 7:171-212, 2017.
Collapse
Affiliation(s)
- Rene Vandenboom
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, Ontario, Canada
| |
Collapse
|
32
|
Myosin light chain phosphorylation is required for peak power output of mouse fast skeletal muscle in vitro. Pflugers Arch 2016; 468:2007-2016. [DOI: 10.1007/s00424-016-1897-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 10/13/2016] [Accepted: 10/18/2016] [Indexed: 10/20/2022]
|
33
|
Hering T, Braubach P, Landwehrmeyer GB, Lindenberg KS, Melzer W. Fast-to-Slow Transition of Skeletal Muscle Contractile Function and Corresponding Changes in Myosin Heavy and Light Chain Formation in the R6/2 Mouse Model of Huntington's Disease. PLoS One 2016; 11:e0166106. [PMID: 27820862 PMCID: PMC5098792 DOI: 10.1371/journal.pone.0166106] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 10/24/2016] [Indexed: 11/18/2022] Open
Abstract
Huntington´s disease (HD) is a hereditary neurodegenerative disease resulting from an expanded polyglutamine sequence (poly-Q) in the protein huntingtin (HTT). Various studies report atrophy and metabolic pathology of skeletal muscle in HD and suggest as part of the process a fast-to-slow fiber type transition that may be caused by the pathological changes in central motor control or/and by mutant HTT in the muscle tissue itself. To investigate muscle pathology in HD, we used R6/2 mice, a common animal model for a rapidly progressing variant of the disease expressing exon 1 of the mutant human gene. We investigated alterations in the extensor digitorum longus (EDL), a typical fast-twitch muscle, and the soleus (SOL), a slow-twitch muscle. We focussed on mechanographic measurements of excised muscles using single and repetitive electrical stimulation and on the expression of the various myosin isoforms (heavy and light chains) using dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of whole muscle and single fiber preparations. In EDL of R6/2, the functional tests showed a left shift of the force-frequency relation and decrease in specific force. Moreover, the estimated relative contribution of the fastest myosin isoform MyHC IIb decreased, whereas the contribution of the slower MyHC IIx isoform increased. An additional change occurred in the alkali MyLC forms showing a decrease in 3f and an increase in 1f level. In SOL, a shift from fast MyHC IIa to the slow isoform I was detectable in male R6/2 mice only, and there was no evidence of isoform interconversion in the MyLC pattern. These alterations point to a partial remodeling of the contractile apparatus of R6/2 mice towards a slower contractile phenotype, predominantly in fast glycolytic fibers.
Collapse
Affiliation(s)
- Tanja Hering
- Institute of Applied Physiology, Ulm University, Ulm, Germany
- Department of Neurology, Ulm University, Ulm, Germany
| | - Peter Braubach
- Institute of Applied Physiology, Ulm University, Ulm, Germany
- Institute of Pathology, Hannover Medical School, Hannover, Germany
| | | | | | - Werner Melzer
- Institute of Applied Physiology, Ulm University, Ulm, Germany
- * E-mail:
| |
Collapse
|
34
|
Chang AN, Kamm KE, Stull JT. Role of myosin light chain phosphatase in cardiac physiology and pathophysiology. J Mol Cell Cardiol 2016; 101:35-43. [PMID: 27742556 DOI: 10.1016/j.yjmcc.2016.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/07/2016] [Accepted: 10/10/2016] [Indexed: 11/18/2022]
Abstract
Maintenance of contractile performance of the heart is achieved in part by the constitutive 40% phosphorylation of myosin regulatory light chain (RLC) in sarcomeres. The importance of this extent of RLC phosphorylation for optimal cardiac performance becomes apparent when various mouse models and resultant phenotypes are compared. The absence or attenuation of RLC phosphorylation results in poor performance leading to heart failure, whereas increased RLC phosphorylation is associated with cardiac protection from stresses. Although information is limited, RLC phosphorylation appears compromised in human heart failure which is consistent with data from mouse studies. The extent of cardiac RLC phosphorylation is determined by the balanced activities of cardiac myosin light chain kinases and phosphatases, the regulatory mechanisms of which are now emerging. This review thusly focuses on kinases that may participate in phosphorylating RLC to make the substrate for cardiac myosin light chain phosphatases, in addition to providing perspectives on the family of myosin light chain phosphatases and involved signaling mechanisms. Because biochemical and physiological information about cardiac myosin light chain phosphatase is sparse, such studies represent an emerging area of investigation in health and disease.
Collapse
Affiliation(s)
- Audrey N Chang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Kristine E Kamm
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - James T Stull
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| |
Collapse
|
35
|
Cardiac myosin light chain is phosphorylated by Ca2+/calmodulin-dependent and -independent kinase activities. Proc Natl Acad Sci U S A 2016; 113:E3824-33. [PMID: 27325775 DOI: 10.1073/pnas.1600633113] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The well-known, muscle-specific smooth muscle myosin light chain kinase (MLCK) (smMLCK) and skeletal muscle MLCK (skMLCK) are dedicated protein kinases regulated by an autoregulatory segment C terminus of the catalytic core that blocks myosin regulatory light chain (RLC) binding and phosphorylation in the absence of Ca(2+)/calmodulin (CaM). Although it is known that a more recently discovered cardiac MLCK (cMLCK) is necessary for normal RLC phosphorylation in vivo and physiological cardiac performance, information on cMLCK biochemical properties are limited. We find that a fourth uncharacterized MLCK, MLCK4, is also expressed in cardiac muscle with high catalytic domain sequence similarity with other MLCKs but lacking an autoinhibitory segment. Its crystal structure shows the catalytic domain in its active conformation with a short C-terminal "pseudoregulatory helix" that cannot inhibit catalysis as a result of missing linker regions. MLCK4 has only Ca(2+)/CaM-independent activity with comparable Vmax and Km values for different RLCs. In contrast, the Vmax value of cMLCK is orders of magnitude lower than those of the other three MLCK family members, whereas its Km (RLC and ATP) and KCaM values are similar. In contrast to smMLCK and skMLCK, which lack activity in the absence of Ca(2+)/CaM, cMLCK has constitutive activity that is stimulated by Ca(2+)/CaM. Potential contributions of autoregulatory segment to cMLCK activity were analyzed with chimeras of skMLCK and cMLCK. The constitutive, low activity of cMLCK appears to be intrinsic to its catalytic core structure rather than an autoinhibitory segment. Thus, RLC phosphorylation in cardiac muscle may be regulated by two different protein kinases with distinct biochemical regulatory properties.
Collapse
|
36
|
Hasnain AU, Saleem R, Ahmad R. Biochemical Variations in Salt Soluble Fractions of Ultrasonicated Actomyosin Isolated from Broiler Breast-Muscle. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2016. [DOI: 10.1080/10942912.2015.1130722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Absar-ul Hasnain
- Section of Genetics, Department of Zoology, Aligarh Muslim University, Aligarh, India
| | - Rashid Saleem
- Section of Genetics, Department of Zoology, Aligarh Muslim University, Aligarh, India
| | - Riaz Ahmad
- Section of Genetics, Department of Zoology, Aligarh Muslim University, Aligarh, India
| |
Collapse
|
37
|
Lai S, Collins BC, Colson BA, Kararigas G, Lowe DA. Estradiol modulates myosin regulatory light chain phosphorylation and contractility in skeletal muscle of female mice. Am J Physiol Endocrinol Metab 2016; 310:E724-33. [PMID: 26956186 PMCID: PMC4867308 DOI: 10.1152/ajpendo.00439.2015] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 03/02/2016] [Indexed: 11/22/2022]
Abstract
Impairment of skeletal muscle function has been associated with changes in ovarian hormones, especially estradiol. To elucidate mechanisms of estradiol on skeletal muscle strength, the hormone's effects on phosphorylation of the myosin regulatory light chain (pRLC) and muscle contractility were investigated, hypothesizing an estradiol-specific beneficial impact. In a skeletal muscle cell line, C2C12, pRLC was increased by 17β-estradiol (E2) in a concentration-dependent manner. In skeletal muscles of C57BL/6 mice that were E2 deficient via ovariectomy (OVX), pRLC was lower than that from ovary-intact, sham-operated mice (Sham). The reduced pRLC in OVX muscle was reversed by in vivo E2 treatment. Posttetanic potentiation (PTP) of muscle from OVX mice was low compared with that from Sham mice, and this decrement was reversed by acute E2 treatment, demonstrating physiological consequence. Western blot of those muscles revealed that low PTP corresponded with low pRLC and higher PTP with greater pRLC. We aimed to elucidate signaling pathways affecting E2-mediated pRLC using a kinase inhibitor library and C2C12 cells as well as a specific myosin light chain kinase inhibitor in muscles. PI3K/Akt, MAPK, and CamKII were identified as candidate kinases sensitive to E2 in terms of phosphorylating RLC. Applying siRNA strategy in C2C12 cells, pRLC triggered by E2 was found to be mediated by estrogen receptor-β and the G protein-coupled estrogen receptor. Together, these results provide evidence that E2 modulates myosin pRLC in skeletal muscle and is one mechanism by which this hormone can affect muscle contractility in females.
Collapse
Affiliation(s)
- Shaojuan Lai
- Programs in Rehabilitation Sciences and Physical Therapy, Department of Physical Medicine and Rehabilitation, Medical School, University of Minnesota, Minneapolis, Minnesota; College of Biological Engineering, Henan University of Technology, Zhengzhou, Henan, China; and
| | - Brittany C Collins
- Programs in Rehabilitation Sciences and Physical Therapy, Department of Physical Medicine and Rehabilitation, Medical School, University of Minnesota, Minneapolis, Minnesota
| | - Brett A Colson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota
| | - Georgios Kararigas
- Institute of Gender in Medicine, Charite University Hospital, and German Centre for Cardiovascular Research (DZHK), Partner Site, Berlin, Germany
| | - Dawn A Lowe
- Programs in Rehabilitation Sciences and Physical Therapy, Department of Physical Medicine and Rehabilitation, Medical School, University of Minnesota, Minneapolis, Minnesota;
| |
Collapse
|
38
|
Yu H, Chakravorty S, Song W, Ferenczi MA. Phosphorylation of the regulatory light chain of myosin in striated muscle: methodological perspectives. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2016; 45:779-805. [PMID: 27084718 PMCID: PMC5101276 DOI: 10.1007/s00249-016-1128-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/10/2016] [Accepted: 03/23/2016] [Indexed: 12/18/2022]
Abstract
Phosphorylation of the regulatory light chain (RLC) of myosin modulates cellular functions such as muscle contraction, mitosis, and cytokinesis. Phosphorylation defects are implicated in a number of diseases. Here we focus on striated muscle where changes in RLC phosphorylation relate to diseases such as hypertrophic cardiomyopathy and muscular dystrophy, or age-related changes. RLC phosphorylation in smooth muscle and non-muscle cells are covered briefly where relevant. There is much scientific interest in controlling the phosphorylation levels of RLC in vivo and in vitro in order to understand its physiological function in striated muscles. A summary of available and emerging in vivo and in vitro methods is presented. The physiological role of RLC phosphorylation and novel pathways are discussed to highlight the differences between muscle types and to gain insights into disease processes.
Collapse
Affiliation(s)
- Haiyang Yu
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Level 3, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Samya Chakravorty
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Level 3, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Weihua Song
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Level 3, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Michael A Ferenczi
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Level 3, 59 Nanyang Drive, Singapore, 636921, Singapore.
| |
Collapse
|
39
|
Chen L, Li X, Ni N, Liu Y, Chen L, Wang Z, Shen QW, Zhang D. Phosphorylation of myofibrillar proteins in post-mortem ovine muscle with different tenderness. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2016; 96:1474-83. [PMID: 25950868 DOI: 10.1002/jsfa.7244] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 02/13/2015] [Accepted: 04/28/2015] [Indexed: 05/23/2023]
Abstract
BACKGROUND Tenderness is one of the most important quality attributes especially for beef and lamb. As protein phosphorylation and dephosphorylation regulate glycolysis, muscle contraction and turnover of proteins within living cells, it may contribute to the conversion of muscle to meat. The changes of myofibrillar protein phosphorylation in post-mortem ovine muscle with different levels of tenderness were investigated in this study. RESULTS The protein phosphorylation level (P/T ratio) of the tender group increased from 0.5 to 12 h post mortem and then decreased. The P/T ratio of tough group increased during 24 h post mortem, increasing faster from 0.5 to 4 h post mortem than from 4 to 24 h post mortem.The global phosphorylation level of tough meat was significantly higher than tender meat at 4, 12 and 24 h post mortem (P < 0.05). Protein identification revealed that most of the phosphoproteins were proteins with sarcomeric function; the others were involved in glycometabolism, stress response, etc. The phosphorylation levels of myofibrillar proteins, e.g. myosin light chain 2 and actin, were significantly different among groups of different tenderness and at different post-mortem time points (P < 0.05). CONCLUSION Protein phosphorylation may influence meat rigor mortis through contractile machinery and glycolysis, which in turn affect meat tenderness.
Collapse
Affiliation(s)
- Lijuan Chen
- Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, People's Republic of China
| | - Xin Li
- Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, People's Republic of China
| | - Na Ni
- Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, People's Republic of China
| | - Yue Liu
- Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, People's Republic of China
| | - Li Chen
- Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, People's Republic of China
| | - Zhenyu Wang
- Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, People's Republic of China
| | - Qingwu W Shen
- Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, People's Republic of China
| | - Dequan Zhang
- Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, People's Republic of China
- Synergetic Innovation Center of Food Safety and Nutrition, Beijing 100193, People's Republic of China
| |
Collapse
|
40
|
|
41
|
Chang AN, Battiprolu PK, Cowley PM, Chen G, Gerard RD, Pinto JR, Hill JA, Baker AJ, Kamm KE, Stull JT. Constitutive phosphorylation of cardiac myosin regulatory light chain in vivo. J Biol Chem 2015; 290:10703-16. [PMID: 25733667 DOI: 10.1074/jbc.m115.642165] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Indexed: 01/03/2023] Open
Abstract
In beating hearts, phosphorylation of myosin regulatory light chain (RLC) at a single site to 0.45 mol of phosphate/mol by cardiac myosin light chain kinase (cMLCK) increases Ca(2+) sensitivity of myofilament contraction necessary for normal cardiac performance. Reduction of RLC phosphorylation in conditional cMLCK knock-out mice caused cardiac dilation and loss of cardiac performance by 1 week, as shown by increased left ventricular internal diameter at end-diastole and decreased fractional shortening. Decreased RLC phosphorylation by conventional or conditional cMLCK gene ablation did not affect troponin-I or myosin-binding protein-C phosphorylation in vivo. The extent of RLC phosphorylation was not changed by prolonged infusion of dobutamine or treatment with a β-adrenergic antagonist, suggesting that RLC is constitutively phosphorylated to maintain cardiac performance. Biochemical studies with myofilaments showed that RLC phosphorylation up to 90% was a random process. RLC is slowly dephosphorylated in both noncontracting hearts and isolated cardiac myocytes from adult mice. Electrically paced ventricular trabeculae restored RLC phosphorylation, which was increased to 0.91 mol of phosphate/mol of RLC with inhibition of myosin light chain phosphatase (MLCP). The two RLCs in each myosin appear to be readily available for phosphorylation by a soluble cMLCK, but MLCP activity limits the amount of constitutive RLC phosphorylation. MLCP with its regulatory subunit MYPT2 bound tightly to myofilaments was constitutively phosphorylated in beating hearts at a site that inhibits MLCP activity. Thus, the constitutive RLC phosphorylation is limited physiologically by low cMLCK activity in balance with low MLCP activity.
Collapse
Affiliation(s)
| | | | - Patrick M Cowley
- the Veterans Affairs Medical Center, San Francisco, California 94143, the University of California, San Francisco, California 94143, and
| | | | - Robert D Gerard
- Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Jose R Pinto
- the Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida 32306
| | - Joseph A Hill
- Internal Medicine (Cardiology), and Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Anthony J Baker
- the Veterans Affairs Medical Center, San Francisco, California 94143, the University of California, San Francisco, California 94143, and
| | | | | |
Collapse
|
42
|
Hortemo KH, Aronsen JM, Lunde IG, Sjaastad I, Lunde PK, Sejersted OM. Exhausting treadmill running causes dephosphorylation of sMLC2 and reduced level of myofilament MLCK2 in slow twitch rat soleus muscle. Physiol Rep 2015; 3:3/2/e12285. [PMID: 25713325 PMCID: PMC4393194 DOI: 10.14814/phy2.12285] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Myosin light chain 2 (MLC2) is a small protein in the myosin complex, regulating muscle contractile function by modulating Ca2+ sensitivity of myofilaments. MLC2 can be modified by phosphorylation and O-GlcNAcylation, two reversible and dynamic posttranslational modifications. The slow isoform of MLC2 (sMLC2) is dephosphorylated in soleus muscle during in situ loaded shortening contractions, which correlates with reduction in shortening capacity. Here, we hypothesize that exhausting in vivo treadmill running induces dephosphorylation of MLC2 in slow twitch soleus, but not in fast twitch EDL muscle, and that there are reciprocal changes in MLC2 O-GlcNAcylation. At rest, both phosphorylation and O-GlcNAcylation of MLC2 were lower in slow than fast twitch muscles. One bout of exhausting treadmill running induced dephosphorylation of sMLC2 in soleus, paralleled by reduced levels of the kinase MLCK2 associated to myofilaments, suggesting that the acute reduction in phosphorylation is mediated by dissociation of MLCK2 from myofilaments. O-GlcNAcylation of MLC2 did not change significantly, and seems of limited importance in the regulation of MLC2 phosphorylation during in vivo running. After 6 weeks of treadmill running, the dephosphorylation of sMLC2 persisted in soleus along with reduction in MLCK2 both in myofilament- and total protein fraction. In EDL on the contrary, phosphorylation of MLC2 was not altered after one exercise bout or after 6 weeks of treadmill running. Thus, in contrast to fast twitch muscle, MLC2 dephosphorylation occurs in slow twitch muscle during in vivo exercise and may be linked to reduced myofilament-associated MLCK2 and reduced shortening capacity.
Collapse
Affiliation(s)
- Kristin Halvorsen Hortemo
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Jan Magnus Aronsen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway Bjørknes College, Oslo, Norway
| | - Ida G Lunde
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway Department of Genetics, Harvard Medical School, Boston, Massachusetts
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Per Kristian Lunde
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Ole M Sejersted
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| |
Collapse
|
43
|
Ca2+-dependent regulations and signaling in skeletal muscle: from electro-mechanical coupling to adaptation. Int J Mol Sci 2015; 16:1066-95. [PMID: 25569087 PMCID: PMC4307291 DOI: 10.3390/ijms16011066] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 12/22/2014] [Indexed: 01/07/2023] Open
Abstract
Calcium (Ca2+) plays a pivotal role in almost all cellular processes and ensures the functionality of an organism. In skeletal muscle fibers, Ca(2+) is critically involved in the innervation of skeletal muscle fibers that results in the exertion of an action potential along the muscle fiber membrane, the prerequisite for skeletal muscle contraction. Furthermore and among others, Ca(2+) regulates also intracellular processes, such as myosin-actin cross bridging, protein synthesis, protein degradation and fiber type shifting by the control of Ca(2+)-sensitive proteases and transcription factors, as well as mitochondrial adaptations, plasticity and respiration. These data highlight the overwhelming significance of Ca(2+) ions for the integrity of skeletal muscle tissue. In this review, we address the major functions of Ca(2+) ions in adult muscle but also highlight recent findings of critical Ca(2+)-dependent mechanisms essential for skeletal muscle-regulation and maintenance.
Collapse
|
44
|
Gittings W, Aggarwal H, Stull JT, Vandenboom R. The force dependence of isometric and concentric potentiation in mouse muscle with and without skeletal myosin light chain kinase. Can J Physiol Pharmacol 2015; 93:23-32. [DOI: 10.1139/cjpp-2014-0118] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The isometric potentiation associated with myosin phosphorylation is force dependent. The purpose of this study was to assess the influence of a pre-existing period of isometric force on the concentric force potentiation displayed by mouse muscles with and without the ability to phosphorylate myosin. We tested isometric (ISO) and concentric (CON) potentiation, as well as concentric potentiation after isometric force (ISO-CON), in muscles from wild-type (WT) and skeletal myosin light chain kinase-deficient (skMLCK−/−) mice. A conditioning stimulus increased (i.e., potentiated) mean concentric force in the ISO-CON and CON conditions to 1.31 ± 0.02 and 1.35 ± 0.02 (WT) and to 1.19 ± 0.02 and 1.21 ± 0.01 (skMLCK−/−) of prestimulus levels, respectively (data n = 6–8, p < 0.05). No potentiation of mean isometric force was observed in either genotype. The potentiation of mean concentric force was inversely related to relative tetanic force level (P/Po) in both genotypes. Moreover, concentric potentiation varied greatly within each contraction type and was negatively correlated with unpotentiated force in both genotypes. Thus, although no effect of pre-existing force was observed, strong and inverse relationships between concentric force potentiation and unpotentiated concentric force may suggest an influence of attached and force-generating crossbridges on potentiation magnitude in both WT and skMLCK−/− muscles.
Collapse
Affiliation(s)
- William Gittings
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, 500 Glenridge Avenue, St. Catharines, ON L2S 3A1, Canada
| | - Harish Aggarwal
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, 500 Glenridge Avenue, St. Catharines, ON L2S 3A1, Canada
| | - James T. Stull
- Department of Physiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Rene Vandenboom
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, 500 Glenridge Avenue, St. Catharines, ON L2S 3A1, Canada
| |
Collapse
|
45
|
Smith IC, Vandenboom R, Tupling AR. Juxtaposition of the changes in intracellular calcium and force during staircase potentiation at 30 and 37°C. J Gen Physiol 2014; 144:561-70. [PMID: 25422504 PMCID: PMC4242813 DOI: 10.1085/jgp.201411257] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Temperature-dependent changes in basal calcium and in the calcium transient contribute to force potentiation during repetitive stimulation. Ca2+ entry during the action potential stimulates muscle contraction. During repetitive low frequency stimulation, skeletal muscle undergoes staircase potentiation (SP), a progressive increase in the peak twitch force induced by each successive stimulus. Multiple mechanisms, including myosin regulatory light chain phosphorylation, likely contribute to SP, a temperature-dependent process. Here, we used the Ca2+-sensitive fluorescence indicators acetoxymethyl (AM)-furaptra and AM-fura-2 to examine the intracellular Ca2+ transient (ICT) and the baseline Ca2+ level at the onset of each ICT during SP at 30 and 37°C in mouse lumbrical muscle. The stimulation protocol, 8 Hz for 8 s, resulted in a 27 ± 3% increase in twitch force at 37°C and a 7 ± 2% decrease in twitch force at 30°C (P < 0.05). Regardless of temperature, the peak rate of force production (+df/dt) was higher in all twitches relative to the first twitch (P < 0.05). Consistent with the differential effects of stimulation on twitch force at the two temperatures, raw ICT amplitude decreased during repetitive stimulation at 30°C (P < 0.05) but not at 37°C. Cytosolic Ca2+ accumulated during SP such that baseline Ca2+ at the onset of ICTs occurring late in the train was higher (P < 0.05) than that of those occurring early in the train. ICT duration increased progressively at both temperatures. This effect was not entirely proportional to the changes in twitch duration, as twitch duration characteristically decreased before increasing late in the protocol. This is the first study identifying a changing ICT as an important, and temperature-sensitive, modulator of muscle force during repetitive stimulation. Moreover, we extend previous observations by demonstrating that contraction-induced increases in baseline Ca2+ coincide with greater +df/dt but not necessarily with higher twitch force.
Collapse
Affiliation(s)
- Ian C Smith
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Rene Vandenboom
- Department of Kinesiology, Brock University, St. Catharines, Ontario L2S 3A1, Canada
| | - A Russell Tupling
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| |
Collapse
|
46
|
Huang H, Larsen MR, Palmisano G, Dai J, Lametsch R. Quantitative phosphoproteomic analysis of porcine muscle within 24 h postmortem. J Proteomics 2014; 106:125-39. [PMID: 24769528 DOI: 10.1016/j.jprot.2014.04.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Revised: 04/07/2014] [Accepted: 04/12/2014] [Indexed: 01/20/2023]
Abstract
UNLABELLED Protein phosphorylation can regulate most of the important processes in muscle, such as metabolism and contraction. The postmortem (PM) metabolism and rigor mortis have essential effects on meat quality. In order to identify and characterize the protein phosphorylation events involved in meat quality development, a quantitative mass spectrometry-based phosphoproteomic study was performed to analyze the porcine muscle within 24h PM using dimethyl labeling combined with the TiSH phosphopeptide enrichment strategy. In total 305 unique proteins were identified, including 160 phosphoproteins with 784 phosphorylation sites. Among these, 184 phosphorylation sites on 93 proteins had their phosphorylation levels significantly changed. The proteins involved in glucose metabolism and muscle contraction were the two largest clusters of phosphoproteins with significantly changed phosphorylation levels in muscle within 24 h PM. The high phosphorylation level of heat shock proteins (HSPs) in early PM may be an adaptive response to slaughter stress and protect muscle cell from apoptosis, as observed in the serine 84 of HSP27. This work indicated that PM muscle proteins underwent significant changes at the phosphorylation level but were relatively stable at the total protein level, suggesting that protein phosphorylation may have important roles in meat quality development through the regulation of proteins involved in glucose metabolism and muscle contraction, thereby affecting glycolysis and rigor mortis development in PM muscle. BIOLOGICAL SIGNIFICANCE The manuscript describes the characterization of postmortem (PM) porcine muscle within 24 h postmortem from the perspective of protein phosphorylation using advanced phosphoproteomic techniques. In the study, the authors employed the dimethyl labeling combined with the TiSH phosphopeptide enrichment and LC-MS/MS strategy. This was the first high-throughput quantitative phosphoproteomic study in PM muscle of farm animals. In the work, both the proteome and phosphoproteome were analyzed, and the large number of identified peptides, phosphopeptides and phosphorylation sites can greatly enrich the current farm animal protein database. The proteins involved in glycometabolism, muscle contraction and heat shock proteins (HSPs) showed significantly changed phosphorylation levels during PM meat development. This work indicated that PM muscle proteins underwent significant changes at phosphorylation level but were relatively stable at the total protein level, suggesting that protein phosphorylation may have important roles in meat development through the regulation of proteins involved in metabolism and muscle contraction, thereby affecting glycolysis and rigor mortis development in PM muscle. The work can promote the understanding of PM muscle metabolism and meat quality development, and be helpful for future meat quality control.
Collapse
Affiliation(s)
- Honggang Huang
- Department of Food Science, Faculty of Science, University of Copenhagen, DK-1958 Frederiksberg, Denmark; Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark; The Danish Diabetes Academy, Denmark.
| | - Martin R Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Giuseppe Palmisano
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark; Institute of Biomedical Sciences, Department of Parasitology, USP, São Paulo, Brazil
| | - Jie Dai
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - René Lametsch
- Department of Food Science, Faculty of Science, University of Copenhagen, DK-1958 Frederiksberg, Denmark.
| |
Collapse
|
47
|
Myosin phosphorylation and force potentiation in skeletal muscle: evidence from animal models. J Muscle Res Cell Motil 2013; 34:317-32. [PMID: 24162313 DOI: 10.1007/s10974-013-9363-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 10/04/2013] [Indexed: 01/21/2023]
Abstract
The contractile performance of mammalian fast twitch skeletal muscle is history dependent. The effect of previous or ongoing contractile activity to potentiate force, i.e. increase isometric twitch force, is a fundamental property of fast skeletal muscle. The precise manifestation of force potentiation is dependent upon a variety of factors with two general types being identified; staircase potentiation referring to the progressive increase in isometric twitch force observed during low frequency stimulation while posttetanic potentiation refers to the step-like increase in isometric twitch force observed following a brief higher frequency (i.e. tetanic) stimulation. Classic studies established that the magnitude and duration of potentiation depends on a number of factors including muscle fiber type, species, temperature, sarcomere length and stimulation paradigm. In addition to isometric twitch force, more recent work has shown that potentiation also influences dynamic (i.e. concentric and/or isotonic) force, work and power at a range of stimulus frequencies in situ or in vitro, an effect that may translate to enhanced physiological function in vivo. Early studies performed on both intact and permeabilized models established that the primary mechanism for this modulation of performance was phosphorylation of myosin, a modification that increased the Ca(2+) sensitivity of contraction. More recent work from a variety of muscle models indicates, however, the presence of a secondary mechanism for potentiation that may involve altered Ca(2+) handling. The primary purpose of this review is to highlight these recent findings relative to the physiological utility of force potentiation in vivo.
Collapse
|
48
|
Smith CB, Allen MD, Rice CL. Voluntary rate of torque development is impaired after a voluntary versus tetanic conditioning contraction. Muscle Nerve 2013; 49:218-24. [DOI: 10.1002/mus.23888] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Cameron B. Smith
- School of Kinesiology, Arthur and Sonia Labatt Health Sciences Building; University of Western Ontario; London Ontario N6A 5B9 Canada
| | - Matti D. Allen
- School of Kinesiology, Arthur and Sonia Labatt Health Sciences Building; University of Western Ontario; London Ontario N6A 5B9 Canada
| | - Charles L. Rice
- School of Kinesiology, Arthur and Sonia Labatt Health Sciences Building; University of Western Ontario; London Ontario N6A 5B9 Canada
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry; University of Western Ontario; London Ontario Canada
| |
Collapse
|
49
|
Cheng AJ, Place N, Bruton JD, Holmberg HC, Westerblad H. Doublet discharge stimulation increases sarcoplasmic reticulum Ca2+ release and improves performance during fatiguing contractions in mouse muscle fibres. J Physiol 2013; 591:3739-48. [PMID: 23690559 DOI: 10.1113/jphysiol.2013.257188] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Double discharges (doublets) of motor neurones at the onset of contractions increase both force and rate of force development during voluntary submaximal contractions. The purpose of this study was to examine the role of doublet discharges on force and myoplasmic free [Ca(2+)] ([Ca(2+)]i) during repeated fatiguing contractions, using a stimulation protocol mimicking the in vivo activation pattern during running. Individual intact fibres from the flexor digitorum brevis muscle of mice were stimulated at 33°C to undergo 150 constant-frequency (five pulses at 70 Hz) or doublet (an initial, extra pulse at 200 Hz) contractions at 300 ms intervals. In the unfatigued state, doublet stimulation resulted in a transient (∼10 ms) approximate doubling of [Ca(2+)]i, which was accompanied by a greater force-time integral (∼70%) and peak force (∼40%) compared to constant frequency contractions. Moreover, doublets markedly increased force-time integral and peak force during the first 25 contractions of the fatiguing stimulation. In later stages of fatigue, addition of doublets increased force production but the increase in force production corresponded to only a minor portion of the fatigue-induced reduction in force. In conclusion, double discharges at the onset of contractions effectively increase force production, especially in early stages of fatigue. This beneficial effect occurs without additional force loss in later stages of fatigue, indicating that the additional energy cost induced by doublet discharges to skeletal muscle is limited.
Collapse
Affiliation(s)
- Arthur J Cheng
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden, 171 77.
| | | | | | | | | |
Collapse
|
50
|
Smith IC, Gittings W, Huang J, McMillan EM, Quadrilatero J, Tupling AR, Vandenboom R. Potentiation in mouse lumbrical muscle without myosin light chain phosphorylation: is resting calcium responsible? ACTA ACUST UNITED AC 2013; 141:297-308. [PMID: 23401574 PMCID: PMC3581688 DOI: 10.1085/jgp.201210918] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The increase in isometric twitch force observed in fast-twitch rodent muscles during or after activity, known universally as potentiation, is normally associated with myosin regulatory light chain (RLC) phosphorylation. Interestingly, fast muscles from mice devoid of detectable skeletal myosin light chain kinase (skMLCK) retain a reduced ability to potentiate twitch force, indicating the presence of a secondary origin for this characteristic feature of the fast muscle phenotype. The purpose of this study was to assess changes in intracellular cytosolic free Ca2+ concentration ([Ca2+]i) after a potentiating stimulus in mouse lumbrical muscle (37°C). Lumbricals were loaded with the Ca2+-sensitive fluorescent indicators fura-2 or furaptra to detect changes in resting and peak, respectively, intracellular Ca2+ levels caused by 2.5 s of 20-Hz stimulation. Although this protocol produced an immediate increase in twitch force of 17 ± 3% (all data are n = 10) (P < 0.01), this potentiation dissipated quickly and was absent 30 s afterward. Fura-2 fluorescence signals at rest were increased by 11.1 ± 1.3% (P < 0.01) during potentiation, indicating a significant increase in resting [Ca2+]i. Interestingly, furaptra signals showed no change to either the amplitude or the duration of the intracellular Ca2+ transients (ICTs) that triggered potentiated twitches during this time (P < 0.50). Immunofluorescence work showed that 77% of lumbrical fibers expressed myosin heavy chain isoform IIx and/or IIb, but with low expression of skMLCK and high expression of myosin phosphatase targeting subunit 2. As a result, lumbrical muscles displayed no detectable RLC phosphorylation either at rest or after stimulation. We conclude that stimulation-induced elevations in resting [Ca2+]i, in the absence of change in the ICT, are responsible for a small-magnitude, short-lived potentiation of isometric twitch force. If operative in other fast-twitch muscles, this mechanism may complement the potentiating influence of myosin RLC phosphorylation.
Collapse
Affiliation(s)
- Ian C Smith
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | | | | | | | | | | | | |
Collapse
|