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Mizuno T, Hosoyama T, Tomida M, Yamamoto Y, Nakamichi Y, Kato S, Kawai-Takaishi M, Ishizuka S, Nishita Y, Tange C, Shimokata H, Imagama S, Otsuka R. Influence of vitamin D on sarcopenia pathophysiology: A longitudinal study in humans and basic research in knockout mice. J Cachexia Sarcopenia Muscle 2022; 13:2961-2973. [PMID: 36237134 PMCID: PMC9745482 DOI: 10.1002/jcsm.13102] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 08/10/2022] [Accepted: 09/02/2022] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Vitamin D is an essential nutrient in musculoskeletal function; however, its relationship to sarcopenia remains ambiguous, and the mechanisms and targets of vitamin D activity have not been elucidated. This study aimed to clarify the role of vitamin D in mature skeletal muscle and its relationship with sarcopenia. METHODS This epidemiological study included 1653 community residents who participated in both the fifth and seventh waves of the National Institute for Longevity Sciences, Longitudinal Study of Aging and had complete background data. Participants were classified into two groups: vitamin D-deficient (serum 25-hydroxyvitamin D < 20 ng/mL) and non-deficient (serum 25-hydroxyvitamin D ≥ 20 ng/mL); they underwent propensity-score matching for background factors (age, sex, height, weight, comorbidities, smoker, alcohol intake, energy intake, vitamin D intake, steps, activity, season and sarcopenia). Changes in muscle strength and mass over the 4-year period were compared. For basic analysis, we generated Myf6CreERT2 Vitamin D Receptor (VDR)-floxed (VdrmcKO ) mice with mature muscle fibre-specific vitamin D receptor knockout, injected tamoxifen into 8-week-old mice and analysed various phenotypes at 16 weeks of age. RESULTS Grip strength reduction was significantly greater in the deficient group (-1.55 ± 2.47 kg) than in the non-deficient group (-1.13 ± 2.47 kg; P = 0.019). Appendicular skeletal muscle mass reduction did not differ significantly between deficient (-0.05 ± 0.79 kg) and non-deficient (-0.01 ± 0.74 kg) groups (P = 0.423). The incidence of new cases of sarcopenia was significantly higher in the deficient group (15 vs. 5 cases; P = 0.039). Skeletal muscle phenotyping of VdrmcKO mice showed no significant differences in muscle weight, myofibre percentage or myofibre cross-sectional area; however, both forelimb and four-limb muscle strength were significantly lower in VdrmcKO mice (males: forelimb, P = 0.048; four-limb, P = 0.029; females: forelimb, P < 0.001; four-limb, P < 0.001). Expression profiling revealed a significant decrease in expression of sarcoendoplasmic reticulum Ca2+ -ATPase (SERCA) 1 (P = 0.019) and SERCA2a (P = 0.049) genes in the VdrmcKO mice. In contrast, expression of non-muscle SERCA2b and myoregulin genes showed no changes. CONCLUSIONS Vitamin D deficiency affects muscle strength and may contribute to the onset of sarcopenia. Vitamin D-VDR signalling has minimal influence on the regulation of muscle mass in mature myofibres but has a significant influence on muscle strength.
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Affiliation(s)
- Takafumi Mizuno
- Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Department of Musculoskeletal Disease, Geroscience Research Center, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Tohru Hosoyama
- Department of Musculoskeletal Disease, Geroscience Research Center, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Makiko Tomida
- Department of Epidemiology of Aging, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Yoko Yamamoto
- Department of Surgical Oncology, The University of Tokyo, Tokyo, Japan
| | - Yuko Nakamichi
- Institute for Oral Science, Matsumoto Dental University, Nagano, Japan
| | - Shigeaki Kato
- Graduate School of Life Science and Engineering, Iryo Sosei University, Fukushima, Japan.,Research Institute of Innovative Medicine, Tokiwa Foundation, Fukushima, Japan
| | - Minako Kawai-Takaishi
- Department of Musculoskeletal Disease, Geroscience Research Center, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Shinya Ishizuka
- Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yukiko Nishita
- Department of Epidemiology of Aging, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Chikako Tange
- Department of Epidemiology of Aging, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Hiroshi Shimokata
- Department of Epidemiology of Aging, National Center for Geriatrics and Gerontology, Obu, Japan.,Graduate School of Nutritional Sciences, Nagoya University of Arts and Sciences, Nagoya, Japan
| | - Shiro Imagama
- Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Rei Otsuka
- Department of Epidemiology of Aging, National Center for Geriatrics and Gerontology, Obu, Japan
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Elkes M, Andonovski M, Vidal D, Farago M, Modafferi R, Claypool SM, LeBlanc PJ. The Influence of Supplemental Dietary Linoleic Acid on Skeletal Muscle Contractile Function in a Rodent Model of Barth Syndrome. Front Physiol 2021; 12:731961. [PMID: 34489741 PMCID: PMC8416984 DOI: 10.3389/fphys.2021.731961] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/02/2021] [Indexed: 11/13/2022] Open
Abstract
Barth syndrome is a rare and incurable X-linked (male-specific) genetic disease that affects the protein tafazzin (Taz). Taz is an important enzyme responsible for synthesizing biologically relevant cardiolipin (for heart and skeletal muscle, cardiolipin rich in linoleic acid), a critical phospholipid of mitochondrial form and function. Mutations to Taz cause dysfunctional mitochondria, resulting in exercise intolerance due to skeletal muscle weakness. To date, there has been limited research on improving skeletal muscle function, with interventions focused on endurance and resistance exercise. Previous cell culture research has shown therapeutic potential for the addition of exogenous linoleic acid in improving Taz-deficient mitochondrial function but has not been examined in vivo. The purpose of this study was to examine the influence of supplemental dietary linoleic acid on skeletal muscle function in a rodent model of Barth syndrome, the inducible Taz knockdown (TazKD) mouse. One of the main findings was that TazKD soleus demonstrated an impaired contractile phenotype (slower force development and rates of relaxation) in vitro compared to their WT littermates. Interestingly, this impaired contractile phenotype seen in vitro did not translate to altered muscle function in vivo at the whole-body level. Also, supplemental linoleic acid attenuated, to some degree, in vitro impaired contractile phenotype in TazKD soleus, and these findings appear to be partially mediated by improvements in cardiolipin content and resulting mitochondrial supercomplex formation. Future research will further examine alternative mechanisms of dietary supplemental LA on improving skeletal muscle contractile dysfunction in TazKD mice.
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Affiliation(s)
- Mario Elkes
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Martin Andonovski
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Daislyn Vidal
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Madison Farago
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Ryan Modafferi
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Paul J LeBlanc
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
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Francis MR, Pinniger GJ, Noble PB, Wang KCW. Intrauterine growth restriction affects diaphragm function in adult female and male mice. Pediatr Pulmonol 2020; 55:229-235. [PMID: 31535471 DOI: 10.1002/ppul.24519] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 08/30/2019] [Indexed: 01/10/2023]
Abstract
BACKGROUND In utero diaphragm development is critically important for postnatal respiratory function and any disturbance to fetal development may lead to diaphragm dysfunction and respiratory complications in the postnatal period. Intrauterine growth restriction (IUGR) has been shown to affect respiratory function in a sex-dependent manner; however, the effect of IUGR on diaphragm function is unknown. AIM This study used a maternal hypoxia-induced mouse model of IUGR to investigate the impact of IUGR on diaphragm function and structure in male and female adult offspring. MATERIALS AND METHODS Pregnant BALB/c mice were housed under hypoxic conditions (10.5% O2 ) from gestational days 11 to 17.5 and then returned to normoxic conditions. Control mice were housed under normoxic conditions throughout pregnancy. At 8 weeks of age, offspring were euthanized and diaphragms isolated for functional assessment in organ bath experiments and for histological analysis. RESULTS IUGR offspring were lighter at birth and remained lighter at 8 weeks of age compared to Controls. While diaphragm force (maximal or twitch) was not affected by treatment or sex, the IUGR group exhibited a longer half-relaxation time after twitch contractions compared to Control. Female offspring had a lower maximum rate of force development and higher fatigue resistance compared to males, independent of IUGR. There was no difference in the diaphragm myofibre cross-sectional area between groups or sexes. CONCLUSION Sex and IUGR independently affect diaphragm contraction in adult mice without changes in structure. This study demonstrates that IUGR affects diaphragm contractile function in later life and could impair respiratory function if exacerbated under conditions of increased respiratory load.
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Affiliation(s)
- Maddison R Francis
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - Gavin J Pinniger
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - Peter B Noble
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - Kimberley C W Wang
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia.,Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia
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Zhang JY, Gong Y, Yang MR, Wu J, Li ST. Effect of acute peritonitis on rocuronium-induced intraperitoneal pressure reduction and the uptake function of the sarcoplasmic reticulum. Exp Ther Med 2017; 13:2707-2714. [PMID: 28587334 PMCID: PMC5450654 DOI: 10.3892/etm.2017.4328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 01/26/2017] [Indexed: 11/09/2022] Open
Abstract
Previous studies have reported the incomplete relaxation effect of neuromuscular blockers on skeletal muscles in acute peritonitis (AP) and other inflammatory processes; however, the underlying mechanisms responsible for this effect have not yet been satisfactorily identified. The impaired removal of cytosolic Ca2+ through sarcoendoplasmic Ca2+-ATPase (SERCA) and defects in sarcoplasmic reticulum (SR) Ca2+ uptake are the major contributing factors to diastolic dysfunction. Previous studies on the effects of neuromuscular blockers have primarily focused on neuromuscular transmission. Because of the reduced calcium uptake in the SR itself, even when neuromuscular transmission is fully blocked, the muscle is not able to relax effectively. In the present study, the impact of AP on rocuronium-induced intraperitoneal pressure reduction and rectus abdominal muscle relaxation, and SERCA uptake function was investigated. AP was induced via gastric perforation and changes in the intraperitoneal pressure before and after the administration of rocuronium were recorded. Muscle contractile properties, uptake and release functions and SERCA activity in the rectus abdominal muscles of AP model rats were measured. The half-relaxation time in the AP group was significantly prolonged compared with that in the control group (P<0.01). The peak rate of SR Ca2+ uptake for whole muscle homogenates was significantly reduced (P<0.05) in AP model rats without reduction of the rate of Ca2+ release evoked through AgNO3. In conclusion, gastric perforation-induced AP attenuates the intraperitoneal pressure-reducing effect of rocuronium, and AP induces diastolic dysfunction of the rectus abdominal muscle. The SR Ca2+-ATPase uptake rate was also reduced by AP.
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Yocum GT, Chen J, Choi CH, Townsend EA, Zhang Y, Xu D, Fu XW, Sanderson MJ, Emala CW. Role of transient receptor potential vanilloid 1 in the modulation of airway smooth muscle tone and calcium handling. Am J Physiol Lung Cell Mol Physiol 2017; 312:L812-L821. [PMID: 28336810 DOI: 10.1152/ajplung.00064.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 03/10/2017] [Accepted: 03/21/2017] [Indexed: 11/22/2022] Open
Abstract
Asthma is a common disorder characterized, in part, by airway smooth muscle (ASM) hyperresponsiveness. Transient receptor potential vanilloid 1 (TRPV1) is a nonselective cation channel expressed on airway nerve fibers that modulates afferent signals, resulting in cough, and potentially bronchoconstriction. In the present study, the TRPV1 transcript was detected by RT-PCR in primary cultured human ASM cells, and the TRPV1 protein was detected in ASM of human trachea by immunohistochemistry. Proximity ligation assays suggest that TRPV1 is expressed in the sarcoplasmic reticulum membrane of human ASM cells in close association with sarco/endoplasmic reticulum Ca2+-ATPase-2. In guinea pig tracheal ring organ bath experiments, the TRPV1 agonist capsaicin led to ASM contraction, but this contraction was significantly attenuated by the sodium channel inhibitor bupivacaine (n = 4, P < 0.05) and the neurokinin-2 receptor antagonist GR-159897 (n = 4, P < 0.05), suggesting that this contraction is neutrally mediated. However, pretreatment of guinea pig and human ASM in organ bath experiments with the TRPV1 antagonist capsazepine inhibited the maintenance phase of an acetylcholine-induced contraction (n = 4, P < 0.01 for both species). Similarly, capsazepine inhibited methacholine-induced contraction of peripheral airways in mouse precision-cut lung slice (PCLS) experiments (n = 4-5, P < 0.05). Although capsazepine did not inhibit store-operated calcium entry in mouse ASM cells in PCLS (n = 4-7, P = nonsignificant), it did inhibit calcium oscillations (n = 3, P < 0.001). These studies suggest that TRPV1 is expressed on ASM, including the SR, but that ASM TRPV1 activation does not play a significant role in initiation of ASM contraction. However, capsazepine does inhibit maintenance of contraction, likely by inhibiting calcium oscillations.
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Affiliation(s)
- Gene T Yocum
- Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, New York; and
| | - Jun Chen
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Christine H Choi
- Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, New York; and
| | - Elizabeth A Townsend
- Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, New York; and
| | - Yi Zhang
- Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, New York; and
| | - Dingbang Xu
- Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, New York; and
| | - Xiao W Fu
- Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, New York; and
| | - Michael J Sanderson
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Charles W Emala
- Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, New York; and
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Wu J, Zhang JY, Gong Y, Li ST. Slowed relaxation of diaphragm in septic rats is associated with reduced expression of sarco-endoplasmic reticulum CA2+-ATPase genesSERCA1andSERCA2. Muscle Nerve 2016; 54:1108-1113. [PMID: 27104787 DOI: 10.1002/mus.25150] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2016] [Indexed: 01/02/2023]
Affiliation(s)
- Jin Wu
- Department of Anesthesiology, First People's Hospital, School of Medicine; Shanghai Jiaotong University; 100 Hai Ning Road Shanghai 20080 China
| | - Jian You Zhang
- Department of Anesthesiology, First People's Hospital, School of Medicine; Shanghai Jiaotong University; 100 Hai Ning Road Shanghai 20080 China
| | - Yuan Gong
- Department of Anesthesiology, First People's Hospital, School of Medicine; Shanghai Jiaotong University; 100 Hai Ning Road Shanghai 20080 China
| | - Shi Tong Li
- Department of Anesthesiology, First People's Hospital, School of Medicine; Shanghai Jiaotong University; 100 Hai Ning Road Shanghai 20080 China
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Olsson K, Cheng AJ, Alam S, Al-Ameri M, Rullman E, Westerblad H, Lanner JT, Bruton JD, Gustafsson T. Intracellular Ca(2+)-handling differs markedly between intact human muscle fibers and myotubes. Skelet Muscle 2015; 5:26. [PMID: 26301072 PMCID: PMC4545874 DOI: 10.1186/s13395-015-0050-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 07/21/2015] [Indexed: 12/14/2022] Open
Abstract
Background In skeletal muscle, intracellular Ca2+ is an important regulator of contraction as well as gene expression and metabolic processes. Because of the difficulties to obtain intact human muscle fibers, human myotubes have been extensively employed for studies of Ca2+-dependent processes in human adult muscle. Despite this, it is unknown whether the Ca2+-handling properties of myotubes adequately represent those of adult muscle fibers. Methods To enable a comparison of the Ca2+-handling properties of human muscle fibers and myotubes, we developed a model of dissected intact single muscle fibers obtained from human intercostal muscle biopsies. The intracellular Ca2+-handling of human muscle fibers was compared with that of myotubes generated by the differentiation of primary human myoblasts obtained from vastus lateralis muscle biopsies. Results The intact single muscle fibers all demonstrated strictly regulated cytosolic free [Ca2+] ([Ca2+]i) transients and force production upon electrical stimulation. In contrast, despite a more mature Ca2+-handling in myotubes than in myoblasts, myotubes lacked fundamental aspects of adult Ca2+-handling and did not contract. These functional differences were explained by discrepancies in the quantity and localization of Ca2+-handling proteins, as well as ultrastructural differences between muscle fibers and myotubes. Conclusions Intact single muscle fibers that display strictly regulated [Ca2+]i transients and force production upon electrical stimulation can be obtained from human intercostal muscle biopsies. In contrast, human myotubes lack important aspects of adult Ca2+-handling and are thus an inappropriate model for human adult muscle when studying Ca2+-dependent processes, such as gene expression and metabolic processes. Electronic supplementary material The online version of this article (doi:10.1186/s13395-015-0050-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Karl Olsson
- Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, 141 86 Sweden ; Department of Physiology and Pharmacology, Karolinska Institutet, von Eulers väg 8, Stockholm, 171 77 Sweden
| | - Arthur J Cheng
- Department of Physiology and Pharmacology, Karolinska Institutet, von Eulers väg 8, Stockholm, 171 77 Sweden
| | - Seher Alam
- Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, 141 86 Sweden
| | - Mamdoh Al-Ameri
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, 171 76 Sweden
| | - Eric Rullman
- Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, 141 86 Sweden
| | - Håkan Westerblad
- Department of Physiology and Pharmacology, Karolinska Institutet, von Eulers väg 8, Stockholm, 171 77 Sweden
| | - Johanna T Lanner
- Department of Physiology and Pharmacology, Karolinska Institutet, von Eulers väg 8, Stockholm, 171 77 Sweden
| | - Joseph D Bruton
- Department of Physiology and Pharmacology, Karolinska Institutet, von Eulers väg 8, Stockholm, 171 77 Sweden
| | - Thomas Gustafsson
- Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, 141 86 Sweden
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Zyryanova T, Schneider R, Adams V, Sittig D, Kerner C, Gebhardt C, Ruffert H, Glasmacher S, Hepp P, Punkt K, Neuhaus J, Hamann J, Aust G. Skeletal muscle expression of the adhesion-GPCR CD97: CD97 deletion induces an abnormal structure of the sarcoplasmatic reticulum but does not impair skeletal muscle function. PLoS One 2014; 9:e100513. [PMID: 24949957 PMCID: PMC4065095 DOI: 10.1371/journal.pone.0100513] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 05/24/2014] [Indexed: 01/09/2023] Open
Abstract
CD97 is a widely expressed adhesion class G-protein-coupled receptor (aGPCR). Here, we investigated the presence of CD97 in normal and malignant human skeletal muscle as well as the ultrastructural and functional consequences of CD97 deficiency in mice. In normal human skeletal muscle, CD97 was expressed at the peripheral sarcolemma of all myofibers, as revealed by immunostaining of tissue sections and surface labeling of single myocytes using flow cytometry. In muscle cross-sections, an intracellular polygonal, honeycomb-like CD97-staining pattern, typical for molecules located in the T-tubule or sarcoplasmatic reticulum (SR), was additionally found. CD97 co-localized with SR Ca2+-ATPase (SERCA), a constituent of the longitudinal SR, but not with the receptors for dihydropyridine (DHPR) or ryanodine (RYR), located in the T-tubule and terminal SR, respectively. Intracellular expression of CD97 was higher in slow-twitch compared to most fast-twitch myofibers. In rhabdomyosarcomas, CD97 was strongly upregulated and in part more N-glycosylated compared to normal skeletal muscle. All tumors were strongly CD97-positive, independent of the underlying histological subtype, suggesting high sensitivity of CD97 for this tumor. Ultrastructural analysis of murine skeletal myofibers confirmed the location of CD97 in the SR. CD97 knock-out mice had a dilated SR, resulting in a partial increase in triad diameter yet not affecting the T-tubule, sarcomeric, and mitochondrial structure. Despite these obvious ultrastructural changes, intracellular Ca2+ release from single myofibers, force generation and fatigability of isolated soleus muscles, and wheel-running capacity of mice were not affected by the lack of CD97. We conclude that CD97 is located in the SR and at the peripheral sarcolemma of human and murine skeletal muscle, where its absence affects the structure of the SR without impairing skeletal muscle function.
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Affiliation(s)
- Tatiana Zyryanova
- Department of Surgery, Research Laboratories, University of Leipzig, Leipzig, Germany
| | - Rick Schneider
- Department of Surgery, Research Laboratories, University of Leipzig, Leipzig, Germany
| | - Volker Adams
- Heart Center Leipzig, University of Leipzig, Leipzig, Germany
| | - Doreen Sittig
- Department of Surgery, Research Laboratories, University of Leipzig, Leipzig, Germany
| | - Christiane Kerner
- Department of Surgery, Research Laboratories, University of Leipzig, Leipzig, Germany
| | - Claudia Gebhardt
- Department of Surgery, Research Laboratories, University of Leipzig, Leipzig, Germany
| | - Henrik Ruffert
- Department of Anaesthesiology and Intensive Care Medicine, University of Leipzig, Leipzig, Germany
| | - Stefan Glasmacher
- Clinic for Trauma and Reconstructive Surgery, University of Leipzig, Leipzig, Germany
| | - Pierre Hepp
- Clinic for Trauma and Reconstructive Surgery, University of Leipzig, Leipzig, Germany
| | - Karla Punkt
- Institute of Anatomy, University of Leipzig, Leipzig, Germany
| | - Jochen Neuhaus
- Clinic of Urology, Research Laboratories, University of Leipzig, Leipzig, Germany
| | - Jörg Hamann
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Gabriela Aust
- Department of Surgery, Research Laboratories, University of Leipzig, Leipzig, Germany
- * E-mail:
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Seebacher F, Pollard SR, James RS. How well do muscle biomechanics predict whole-animal locomotor performance? The role of Ca2+ handling. J Exp Biol 2012; 215:1847-53. [DOI: 10.1242/jeb.067918] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
SUMMARY
It is important to determine the enabling mechanisms that underlie locomotor performance to explain the evolutionary patterns and ecological success of animals. Our aim was to determine the extent to which calcium (Ca2+) handling dynamics modulate the contractile properties of isolated skeletal muscle, and whether the effects of changing Ca2+ handling dynamics in skeletal muscle are paralleled by changes in whole-animal sprint and sustained swimming performance. Carp (Cyprinus carpio) increased swimming speed by concomitant increases in tail-beat amplitude and frequency. Reducing Ca2+ release from the sarcoplasmic reticulum (SR) by blocking ryanodine receptors with dantrolene decreased isolated peak muscle force and was paralleled by a decrease in tail-beat frequency and whole-animal sprint performance. An increase in fatigue resistance following dantrolene treatment may reflect the reduced depletion of Ca2+ stores in the SR associated with lower ryanodine receptor (RyR) activity. Blocking RyRs may be detrimental by reducing force production and beneficial by reducing SR Ca2+ depletion so that there was no net effect on critical sustained swimming speed (Ucrit). In isolated muscle, there was no negative effect on force production of blocking Ca2+ release via dihydropyridine receptors (DHPRs) with nifedipine. Nifedipine decreased fatigue resistance of isolated muscle, which was paralleled by decreases in tail-beat frequency and Ucrit. However, sprint performance also decreased with DHPR inhibition, which may indicate a role in muscle contraction of the Ca2+ released by DHPR into the myocyte. Inhibiting sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) activity with thapsigargin decreased fatigue resistance, suggesting that SERCA activity is important in avoiding Ca2+ store depletion and fatigue. We have shown that different molecular mechanisms modulate the same muscle and whole-animal traits, which provides an explanatory model for the observed variations in locomotor performance within and between species.
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Affiliation(s)
- Frank Seebacher
- Integrative Physiology, School of Biological Sciences A08, University of Sydney, NSW 2006, Australia
| | - Samuel R. Pollard
- Department of Biomolecular and Sport Sciences, Coventry University, Coventry CV1 5FB, UK
| | - Rob S. James
- Department of Biomolecular and Sport Sciences, Coventry University, Coventry CV1 5FB, UK
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