1
|
Qu J, Dang S, Sun YY, Zhang T, Jiang H, Lu HZ. METTL21C mediates autophagy and formation of slow-twitch muscle fibers in mice after exercise. Genes Genet Syst 2024; 99:n/a. [PMID: 38417894 DOI: 10.1266/ggs.23-00320] [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] [Indexed: 03/01/2024] Open
Abstract
Homeostasis is essential for muscle repair and regeneration after skeletal muscle exercise. This study investigated the role of methyltransferase-like 21C (METTL21C) in skeletal muscle of mice after exercise and the potential mechanism. First, muscle samples were collected at 2, 4 and 6 weeks after exercise, and liver glycogen, muscle glycogen, blood lactic acid and triglyceride were assessed. Moreover, the expression levels of autophagy markers and METTL21C in skeletal muscle were analyzed. The results showed that the expression levels of METTL21C and MYH7 in the gastrocnemius muscle of mice in the exercise group were significantly higher after exercise than those in the control group, which suggested that long-term exercise promoted the formation of slow-twitch muscle fibers in mouse skeletal muscle. Likewise, the autophagy capacity was enhanced with the prolongation of exercise in muscles. The findings were confirmed in mouse C2C12 cells. We discovered that knockdown of Mettl21c reduced the expression of MYH7 and the autophagy level in mouse myoblasts. These findings indicate that METTL21C promotes skeletal muscle homeostasis after exercise by enhancing autophagy, and also contributes to myogenic differentiation and the formation of slow muscle fibers.
Collapse
Affiliation(s)
- Jing Qu
- Institute of Physical Education, Shaanxi University of Technology
| | - Shuai Dang
- School of Biological Science and Engineering, Shaanxi University of Technology
- Department of Medical, Xi'an No.3 Hospital, The Affiliated Hospital of Northwest University
| | - Yuan-Yuan Sun
- School of Biological Science and Engineering, Shaanxi University of Technology
| | - Tao Zhang
- School of Biological Science and Engineering, Shaanxi University of Technology
- Qinba State Key Laboratory of Biological Resources and Ecological Environment, Shaanxi University of Technology
| | - Hai Jiang
- Institute of Physical Education, Shaanxi University of Technology
| | - Hong-Zhao Lu
- School of Biological Science and Engineering, Shaanxi University of Technology
- Qinba State Key Laboratory of Biological Resources and Ecological Environment, Shaanxi University of Technology
| |
Collapse
|
2
|
Biogenesis and Function of Extracellular Vesicles in Pathophysiological Processes Skeletal Muscle Atrophy. Biochem Pharmacol 2022; 198:114954. [DOI: 10.1016/j.bcp.2022.114954] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/08/2022] [Accepted: 02/08/2022] [Indexed: 12/13/2022]
|
3
|
Seo DY, Bae JH, Zhang D, Song W, Kwak HB, Heo JW, Jung SJ, Yun HR, Kim TN, Lee SH, Kim AH, Jeong DH, Kim HK, Han J. Effects of cisplatin on mitochondrial function and autophagy-related proteins in skeletal muscle of rats. BMB Rep 2021. [PMID: 34674798 PMCID: PMC8633523 DOI: 10.5483/bmbrep.2021.54.11.132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Cisplatin is widely known as an anti-cancer drug. However, the effects of cisplatin on mitochondrial function and autophagy-related proteins levels in the skeletal muscle are unclear. The purpose of this study was to investigate the effect of different doses of cisplatin on mitochondrial function and autophagy-re-lated protein levels in the skeletal muscle of rats. Eight-week-old male Wistar rats (n = 24) were assigned to one of three groups; the first group was administered a saline placebo (CON, n = 10), and the second and third groups were given 0.1 mg/kg body weight (BW) (n = 6), and 0.5 mg/kg BW (n = 8) of cisplatin, respectively. The group that had been administered 0.5 mg cisplatin exhibited a reduced BW, skeletal muscle tissue weight, and mitochondrial function and upregulated levels of autophagy-related proteins, including LC3II, Beclin 1, and BNIP3. Moreover, this group had a high LC3 II/I ratio in the skeletal muscle; i.e., the administration of a high dose of cisplatin decreased the muscle mass and mitochondrial function and increased the levels of autophagy-related proteins. These results, thus, suggest that reducing mitochondrial dysfunction and autophagy pathways may be important for preventing skeletal muscle atrophy following cisplatin administration.
Collapse
Affiliation(s)
- Dae Yun Seo
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Smart Marine Therapeutics Center, Cardiovascular and Metabolic Disease Center, Inje University, Busan 47392, Korea
| | - Jun Hyun Bae
- Health & Exercise Science Laboratory, Institute of Sports Science, Seoul National University, Seoul 08826, Korea
- Department of Biomedical Science and Engineering, Inha University, Incheon 22212, Korea
| | - Didi Zhang
- School of Physical Education, Xiang Minzu University, Xianyang 712082, China
| | - Wook Song
- Health & Exercise Science Laboratory, Institute of Sports Science, Seoul National University, Seoul 08826, Korea
- Institute of Aging, Seoul National University, Seoul 08826, Korea
| | - Hyo-Bum Kwak
- Department of Biomedical Science and Engineering, Inha University, Incheon 22212, Korea
| | - Jun-Won Heo
- Department of Biomedical Science and Engineering, Inha University, Incheon 22212, Korea
| | - Su-Jeen Jung
- Department of Leisure Sports, Seoil University, Seoul 02192, Korea
| | - Hyeong Rok Yun
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Smart Marine Therapeutics Center, Cardiovascular and Metabolic Disease Center, Inje University, Busan 47392, Korea
| | - Tae Nyun Kim
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Smart Marine Therapeutics Center, Cardiovascular and Metabolic Disease Center, Inje University, Busan 47392, Korea
| | - Sang Ho Lee
- Department of Taekwondo, Dong-A University, Busan 49315, Korea
| | - Amy Hyein Kim
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Smart Marine Therapeutics Center, Cardiovascular and Metabolic Disease Center, Inje University, Busan 47392, Korea
| | - Dae Hoon Jeong
- Department of Obstetrics and Gynecology, Busan Paik Hospital, College of Medicine, Inje University, Busan 47392, Korea
| | - Hyoung Kyu Kim
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Smart Marine Therapeutics Center, Cardiovascular and Metabolic Disease Center, Inje University, Busan 47392, Korea
| | - Jin Han
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Smart Marine Therapeutics Center, Cardiovascular and Metabolic Disease Center, Inje University, Busan 47392, Korea
| |
Collapse
|
4
|
Cachexia as Evidence of the Mechanisms of Resistance and Tolerance during the Evolution of Cancer Disease. Int J Mol Sci 2021; 22:ijms22062890. [PMID: 33809200 PMCID: PMC8001015 DOI: 10.3390/ijms22062890] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 03/06/2021] [Accepted: 03/09/2021] [Indexed: 02/07/2023] Open
Abstract
During its evolution, cancer induces changes in patients’ energy metabolism that strongly affect the overall clinical state and are responsible for cancer-related cachexia syndrome. To better understand the mechanisms underlying cachexia and its metabolic derangements, research efforts should focus on the events that are driven by the immune system activation during the evolution of neoplastic disease and on the phenomena of “resistance” and “tolerance” typically involved in the human body response against stress, pathogens, or cancer. Indeed, in the case where resistance is not able to eliminate the cancer, tolerance mechanisms can utilize the symptoms of cachexia (anemia, anorexia, and fatigue) to counteract unregulated cancer growth. These notions are also sustained by the evidence that cancer cachexia may be reversible if the resistance and tolerance phases are supported by appropriate antineoplastic treatments. Accordingly, there is no doubt that anticachectic therapies have an irreplaceable role in cases of reversible cancer cachexia where, if harmoniously associated with effective antineoplastic therapies, they can contribute to preserve the quality of life and improve prognosis. Such anticachectic treatments should be based on targeting the complex immunological, inflammatory, and metabolic pathways involved in the complex pathogenesis of cachexia. Meanwhile, the role of the anticachectic therapies is very different in the stage of irreversible cachexia when the available antineoplastic treatments are not able to control the disease and the resistance mechanisms fail with the prevalence of the tolerance phenomena. At this stage, they can be useful only to improve the quality of life, allowing the patient and their family to get a better awareness of the final phases of life, thereby opening to the best spiritual remodulation of the final event, death.
Collapse
|
5
|
Cisplatin-Induced Skeletal Muscle Dysfunction: Mechanisms and Counteracting Therapeutic Strategies. Int J Mol Sci 2020; 21:ijms21041242. [PMID: 32069876 PMCID: PMC7072891 DOI: 10.3390/ijms21041242] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/08/2020] [Accepted: 02/09/2020] [Indexed: 12/17/2022] Open
Abstract
Among the severe side effects induced by cisplatin chemotherapy, muscle wasting is the most relevant one. This effect is a major cause for a clinical decline of cancer patients, since it is a negative predictor of treatment outcome and associated to increased mortality. However, despite its toxicity even at low doses, cisplatin remains the first-line therapy for several types of solid tumors. Thus, effective pharmacological treatments counteracting or minimizing cisplatin-induced muscle wasting are urgently needed. The dissection of the molecular pathways responsible for cisplatin-induced muscle dysfunction gives the possibility to identify novel promising therapeutic targets. In this context, the use of animal model of cisplatin-induced cachexia is very useful. Here, we report an update of the most relevant researches on the mechanisms underlying cisplatin-induced muscle wasting and on the most promising potential therapeutic options to preserve muscle mass and function.
Collapse
|
6
|
Nakamura S, Sato Y, Kobayashi T, Oike T, Kaneko Y, Miyamoto K, Funayama A, Oya A, Nishiwaki T, Matsumoto M, Nakamura M, Kanaji A, Miyamoto T. Insulin-like growth factor-I is required to maintain muscle volume in adult mice. J Bone Miner Metab 2019; 37:627-635. [PMID: 30324536 DOI: 10.1007/s00774-018-0964-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 09/25/2018] [Indexed: 12/20/2022]
Abstract
Insulin-like growth factor-I (IGF-I) is a peptide with diverse functions, among them regulation of embryonic development and bone homeostasis. Serum IGF-I levels decline in the elderly; however, IGF-I function in adults has not been clearly defined. Here, we show that IGF-I is required to maintain muscle mass in adults. We crossed Igf-I flox'd and Mx1 Cre mice to yield Mx1 Cre/Igf-Iflox/flox (IGF-I cKO) mice, and deleted Igf-I in adult mice by polyIpolyC injection. We demonstrate that, although serum IGF-I levels significantly decreased after polyIpolyC injection relative to (Igf-Iflox/flox) controls, serum glucose levels were unchanged. However, muscle mass decreased significantly after IGF-I down-regulation, while bone mass remained the same. In IGF-I cKO muscle, expression of anabolic factors such as Eif4e and p70S6K significantly decreased, while expression of catabolic factors MuRF1 and Atrogin-1 was normal and down-regulated, respectively, suggesting that observed muscle mass reduction was due to perturbed muscle metabolism. Our data demonstrate a specific role for IGF-I in maintaining muscle homeostasis in adults.
Collapse
Affiliation(s)
- Satoshi Nakamura
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Yuiko Sato
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
- Department of Advanced Therapy for Musculoskeletal Disorders, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Tami Kobayashi
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
- Department of Musculoskeletal Reconstruction and Regeneration Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Takatsugu Oike
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Yosuke Kaneko
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Kana Miyamoto
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Atsushi Funayama
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Akihito Oya
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Toru Nishiwaki
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Morio Matsumoto
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Masaya Nakamura
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Arihiko Kanaji
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
| | - Takeshi Miyamoto
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
- Department of Musculoskeletal Reconstruction and Regeneration Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
| |
Collapse
|
7
|
Tseng YT, Chang WH, Lin CC, Chang FR, Wu PC, Lo YC. Protective effects of Liuwei dihuang water extracts on diabetic muscle atrophy. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2019; 53:96-106. [PMID: 30668418 DOI: 10.1016/j.phymed.2018.09.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 08/20/2018] [Accepted: 09/03/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Liuwei dihuang (LWDH), a widely used traditional Chinese herbal medicine, has been noticed for its potential on the improvement of diabetic complications including diabetic nephropathy and diabetic encephalopathy. However, whether LWDH can improve the effects of diabetic skeletal muscle atrophy has not yet been reported. PURPOSE The present study aimed to investigate the protective effects and mechanisms of the water extract of Liuwei dihuang (LWDH-WE) on skeletal muscle in cellular and animal models of diabetic muscle atrophy. STUDY DESIGN The muscle protective effects of LWDH-WE on diabetic muscle atrophy and weakness were examined in methylglyoxal (MG)-treated C2C12 myotubes and streptozotocin (STZ)-treated C57BL/6 mice, respectively. METHODS C2C12 myoblasts were differentiated by differentiation medium to form myotube structures. C2C12 myotubes were pre-treated with LWDH-WE 1 h before MG treatment. Diabetic mice were induced by single intraperitoneal injection of STZ (150 mg/kg) in C57BL/6 mice. Cell viability was determined by MTT and LDH assays. Protein expressions were detected by western blots. Morphological changes of cells were observed by an inverted microscope. Mitochondria membrane potential and reactive oxygen species (ROS) production were measured by flow cytometry. Muscle strength was evaluated by measuring grip strength of mice. RESULTS In C2C12 myotubes, LWDH-WE attenuated MG-induced cellular death and oxidative damage accompanied with improving mitochondrial membrane potential, inhibiting NADPH oxidase (Nox) activation, and ROS production. Moreover, LWDH-WE could attenuate MG-induced atrophy of C2C12 myotubes accompanied with regulating protein synthesis (IGF-1R, Akt, mTOR) and protein degradation (FoxO3a, atrogin-1, MuRF-1) signals. In STZ-induced diabetic mice, LWDH-WE improved body weight and skeletal muscle mass of mice. LWDH-WE also enhanced muscle strength of STZ-induced diabetic mice. Furthermore, LWDH-WE enhanced the improvement of insulin on gastrocnemius muscle mass and grip strength in STZ-treated mice. CONCLUSION LWDH-WE possesses skeletal muscle protection via reducing oxidative damage and regulating protein synthesis and degradation pathways in MG-induced atrophy of C2C12 myotubes. We also reveal the novel protection of LWDH-WE against STZ-induced reduction of muscle mass and muscle strength in mice.
Collapse
Affiliation(s)
- Yu-Ting Tseng
- Department of Pharmacology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Wan-Hsuan Chang
- Department of Pharmacology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Chih-Cheng Lin
- Department of Pharmacology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Fang-Rong Chang
- Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Pao-Chu Wu
- School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Ching Lo
- Department of Pharmacology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
| |
Collapse
|
8
|
Sakai H, Kimura M, Tsukimura Y, Yabe S, Isa Y, Kai Y, Sato F, Kon R, Ikarashi N, Narita M, Chiba Y, Kamei J. Dexamethasone exacerbates cisplatin‐induced muscle atrophy. Clin Exp Pharmacol Physiol 2018; 46:19-28. [DOI: 10.1111/1440-1681.13024] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 07/27/2018] [Accepted: 08/20/2018] [Indexed: 12/21/2022]
Affiliation(s)
- Hiroyasu Sakai
- Department of Biomolecular PharmacologySchool of PharmacyHoshi University Shinagawa‐ku, Tokyo Japan
| | - Minami Kimura
- Department of Analytical PathophysiologySchool of PharmacyHoshi University Shinagawa‐ku, Tokyo Japan
| | - Yuka Tsukimura
- Department of Biomolecular PharmacologySchool of PharmacyHoshi University Shinagawa‐ku, Tokyo Japan
| | - Saori Yabe
- Department of Biomolecular PharmacologySchool of PharmacyHoshi University Shinagawa‐ku, Tokyo Japan
| | - Yosuke Isa
- Department of Biomolecular PharmacologySchool of PharmacyHoshi University Shinagawa‐ku, Tokyo Japan
| | - Yuki Kai
- Department of Biomolecular PharmacologySchool of PharmacyHoshi University Shinagawa‐ku, Tokyo Japan
| | - Fumiaki Sato
- Department of Analytical PathophysiologySchool of PharmacyHoshi University Shinagawa‐ku, Tokyo Japan
| | - Risako Kon
- Department of Biomolecular PharmacologySchool of PharmacyHoshi University Shinagawa‐ku, Tokyo Japan
| | - Nobutomo Ikarashi
- Department of Biomolecular PharmacologySchool of PharmacyHoshi University Shinagawa‐ku, Tokyo Japan
| | - Minoru Narita
- Department of PharmacologySchool of PharmacyHoshi University Shinagawa‐ku, Tokyo Japan
| | - Yoshihiko Chiba
- Department of Physiology and Molecular SciencesSchool of PharmacyHoshi University Shinagawa‐ku, Tokyo Japan
| | - Junzo Kamei
- Department of Biomolecular PharmacologySchool of PharmacyHoshi University Shinagawa‐ku, Tokyo Japan
| |
Collapse
|
9
|
Rooks DS, Laurent D, Praestgaard J, Rasmussen S, Bartlett M, Tankó LB. Effect of bimagrumab on thigh muscle volume and composition in men with casting-induced atrophy. J Cachexia Sarcopenia Muscle 2017; 8:727-734. [PMID: 28905498 PMCID: PMC5659065 DOI: 10.1002/jcsm.12205] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 01/30/2017] [Accepted: 03/01/2017] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Patients experiencing disuse atrophy report acute loss of skeletal muscle mass which subsequently leads to loss of strength and physical capacity. In such patients, especially the elderly, complete recovery remains a challenge even with improved nutrition and resistance exercise. This study aimed to explore the clinical potential of bimagrumab, a human monoclonal antibody targeting the activin type II receptor, for the recovery of skeletal muscle volume from disuse atrophy using an experimental model of lower extremity immobilization. METHODS In this double-blind, placebo-controlled trial, healthy young men (n = 24; mean age, 24.1 years) were placed in a full-length cast of one of the lower extremities for 2 weeks to induce disuse atrophy. After cast removal, subjects were randomized to receive a single intravenous (i.v.) dose of either bimagrumab 30 mg/kg (n = 15) or placebo (n = 9) and were followed for 12 weeks. Changes in thigh muscle volume (TMV) and inter-muscular adipose tissue (IMAT) and subcutaneous adipose tissue (SCAT) of the thigh, maximum voluntary knee extension strength, and safety were assessed throughout the 12 week study. RESULTS Casting resulted in an average TMV loss of -4.8% and comparable increases in IMAT and SCAT volumes. Bimagrumab 30 mg/kg i.v. resulted in a rapid increase in TMV at 2 weeks following cast removal and a +5.1% increase above pre-cast levels at 12 weeks. In comparison, TMV returned to pre-cast level at 12 weeks (-0.1%) in the placebo group. The increased adiposity of the casted leg was sustained in the placebo group and decreased substantially in the bimagrumab group at Week 12 (IMAT: -6.6%, SCAT: -3.5%). Knee extension strength decreased by ~25% in the casted leg for all subjects and returned to pre-cast levels within 6 weeks after cast removal in both treatment arms. Bimagrumab was well tolerated with no serious or severe adverse events reported during the study. CONCLUSIONS A single dose of bimagrumab 30 mg/kg i.v. safely accelerated the recovery of TMV and reversal of accumulated IMAT following 2 weeks in a joint-immobilizing cast.
Collapse
Affiliation(s)
- Daniel S Rooks
- Translational Medicine, Novartis Institutes for BioMedical Research, Cambridge, MA, 02139, USA
| | - Didier Laurent
- Translational Medicine, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Jens Praestgaard
- Translational Medicine, Novartis Institutes for BioMedical Research, Cambridge, MA, 02139, USA
| | | | - Michael Bartlett
- Translational Medicine, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | | |
Collapse
|
10
|
Kravchenko IV, Furalyov VA, Popov VO. Specific titin and myomesin domains stimulate myoblast proliferation. Biochem Biophys Rep 2017; 9:226-231. [PMID: 28956009 PMCID: PMC5614584 DOI: 10.1016/j.bbrep.2016.12.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 12/16/2016] [Accepted: 12/28/2016] [Indexed: 12/11/2022] Open
Abstract
Myofibrillar proteins titin and myomesin stimulated myoblast proliferation as determined by MTT-test and labelled thymidine incorporation in the DNA. Specific Fn type III and Ig-like domains of these proteins were able to exert mitogenic effects as well. Proliferative effect of Fn type III domains was highly sensitive to inhibition of Ca2+/calmodulin dependent protein kinase, whereas the effect of Ig-like domains showed greater sensitivity to the inhibition of adenylyl cyclase – cAMP – PKA pathway. IGF-1 autocrine signalling inhibition partially suppressed mitogenic effects revealed by both domain types. Titin and myomesin as well as their domains stimulate myoblast proliferation. Ig-like and Fn type III domains activate proliferation via different pathways. IGF-1 autocrine signalling is partially involved in observed proliferative effects.
Collapse
Affiliation(s)
- Irina V Kravchenko
- Federal Research Centre of Biotechnology, Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskiy prospect 33, 119071 Moscow, Russia
| | - Vladimir A Furalyov
- Federal Research Centre of Biotechnology, Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskiy prospect 33, 119071 Moscow, Russia
| | - Vladimir O Popov
- Federal Research Centre of Biotechnology, Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskiy prospect 33, 119071 Moscow, Russia
| |
Collapse
|
11
|
Liu C, Wang M, Chen M, Zhang K, Gu L, Li Q, Yu Z, Li N, Meng Q. miR-18a induces myotubes atrophy by down-regulating IgfI. Int J Biochem Cell Biol 2017; 90:145-154. [DOI: 10.1016/j.biocel.2017.07.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 07/05/2017] [Accepted: 07/31/2017] [Indexed: 01/21/2023]
|
12
|
Tseng YT, Chen CS, Jong YJ, Chang FR, Lo YC. Loganin possesses neuroprotective properties, restores SMN protein and activates protein synthesis positive regulator Akt/mTOR in experimental models of spinal muscular atrophy. Pharmacol Res 2016; 111:58-75. [DOI: 10.1016/j.phrs.2016.05.023] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 12/21/2022]
|
13
|
Ulbricht A, Gehlert S, Leciejewski B, Schiffer T, Bloch W, Höhfeld J. Induction and adaptation of chaperone-assisted selective autophagy CASA in response to resistance exercise in human skeletal muscle. Autophagy 2016; 11:538-46. [PMID: 25714469 PMCID: PMC4502687 DOI: 10.1080/15548627.2015.1017186] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Chaperone-assisted selective autophagy (CASA) is a tension-induced degradation pathway essential for muscle maintenance. Impairment of CASA causes childhood muscle dystrophy and cardiomyopathy. However, the importance of CASA for muscle function in healthy individuals has remained elusive so far. Here we describe the impact of strength training on CASA in a group of healthy and moderately trained men. We show that strenuous resistance exercise causes an acute induction of CASA in affected muscles to degrade mechanically damaged cytoskeleton proteins. Moreover, repeated resistance exercise during 4 wk of training led to an increased expression of CASA components. In human skeletal muscle, CASA apparently acts as a central adaptation mechanism that responds to acute physical exercise and to repeated mechanical stimulation.
Collapse
Affiliation(s)
- Anna Ulbricht
- a Institute for Cell Biology; Rheinische Friedrich-Wilhelms-University Bonn ; Bonn , Germany
| | | | | | | | | | | |
Collapse
|
14
|
Negative regulation of initial steps in skeletal myogenesis by mTOR and other kinases. Sci Rep 2016; 6:20376. [PMID: 26847534 PMCID: PMC4742887 DOI: 10.1038/srep20376] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Accepted: 12/31/2015] [Indexed: 11/08/2022] Open
Abstract
The transition from a committed progenitor cell to one that is actively differentiating represents a process that is fundamentally important in skeletal myogenesis. Although the expression and functional activation of myogenic regulatory transcription factors (MRFs) are well known to govern lineage commitment and differentiation, exactly how the first steps in differentiation are suppressed in a proliferating myoblast is much less clear. We used cultured mammalian myoblasts and an RNA interference library targeting 571 kinases to identify those that may repress muscle differentiation in proliferating myoblasts in the presence or absence of a sensitizing agent directed toward CDK4/6, a kinase previously established to impede muscle gene expression. We identified 55 kinases whose knockdown promoted myoblast differentiation, either independently or in conjunction with the sensitizer. A number of the hit kinases could be connected to known MRFs, directly or through one interaction node. Focusing on one hit, Mtor, we validated its role to impede differentiation in proliferating myoblasts and carried out mechanistic studies to show that it acts, in part, by a rapamycin-sensitive complex that involves Raptor. Our findings inform our understanding of kinases that can block the transition from lineage commitment to a differentiating state in myoblasts and offer a useful resource for others studying myogenic differentiation.
Collapse
|
15
|
Anorexia-cachexia and obesity treatment may be two sides of the same coin: role of the TGF-b superfamily cytokine MIC-1/GDF15. Int J Obes (Lond) 2015; 40:193-7. [PMID: 26620888 DOI: 10.1038/ijo.2015.242] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 06/17/2015] [Accepted: 08/12/2015] [Indexed: 12/21/2022]
Abstract
Anorexia-cachexia associated with cancer and other diseases is a common and often fatal condition representing a large area of unmet medical need. It occurs most commonly in advanced cancer and is probably a consequence of molecules released by tumour cells, or tumour-associated interstitial or immune cells. These may then act directly on muscle to cause atrophy and/or may cause anorexia, which then leads to loss of both fat and lean mass. Although the aetiological triggers for this syndrome are not well characterized, recent data suggest that MIC-1/GDF15, a transforming growth factor-beta superfamily cytokine produced in large amounts by cancer cells and as a part of other disease processes, may be an important trigger. This cytokine acts on feeding centres in the hypothalamus and brainstem to cause anorexia leading to loss of lean and fat mass and eventually cachexia. In animal studies, the circulating concentrations of MIC-1/GDF15 required to cause this syndrome are similar to those seen in patients with advanced cancer, and at least some epidemiological studies support an association between MIC-1/GDF15 serum levels and measures of nutrition. This article will discuss its mechanisms of central appetite regulation, and the available data linking this action to anorexia-cachexia syndromes that suggest it is a potential target for therapy of cancer anorexia-cachexia and conversely may also be useful for the treatment of severe obesity.
Collapse
|
16
|
Madeddu C, Mantovani G, Gramignano G, Astara G, Macciò A. Muscle wasting as main evidence of energy impairment in cancer cachexia: future therapeutic approaches. Future Oncol 2015; 11:2697-2710. [PMID: 26376740 DOI: 10.2217/fon.15.195] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The present review aimed at discussing the impact, pathogenesis and therapeutic approaches of muscle wasting, which is a major clinical feature of cancer-related cachexia syndrome. The pathogenesis of muscle wasting in cancer cachexia lies in a discrepancy between anabolic and catabolic pathways mediated by chronic inflammation. Effective interventions specifically aimed at hampering muscle loss and enhancing muscle function are still lacking. Promising agents include anti-inflammatory, orexigenic and anabolic drugs, alongside with nutritional supplements that influence the STAT3 and PI3K/Akt/mTOR pathways involved in muscle wasting. Personalized physical activity combined with pharmacological and nutritional support hold promise. A greater understanding of the pathogenetic processes of cancer cachexia-related muscle wasting will enable the development of an early and effective targeted mechanism-based multimodal approach.
Collapse
Affiliation(s)
- Clelia Madeddu
- Department of Medical Sciences M Aresu, AOU Cagliari, University of Cagliari, Italy
| | - Giovanni Mantovani
- Department of Medical Sciences M Aresu, AOU Cagliari, University of Cagliari, Italy
| | | | - Giorgio Astara
- Department of Medical Sciences M Aresu, AOU Cagliari, University of Cagliari, Italy
| | - Antonio Macciò
- Department of Gynecologic Oncology, A Businco Hospital, Regional Referral Center for Cancer Diseases, Cagliari, Italy
| |
Collapse
|
17
|
White JR, Confides AL, Moore-Reed S, Hoch JM, Dupont-Versteegden EE. Regrowth after skeletal muscle atrophy is impaired in aged rats, despite similar responses in signaling pathways. Exp Gerontol 2015; 64:17-32. [PMID: 25681639 DOI: 10.1016/j.exger.2015.02.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/14/2015] [Accepted: 02/10/2015] [Indexed: 01/07/2023]
Abstract
Skeletal muscle regrowth after atrophy is impaired in the aged and in this study we hypothesized that this can be explained by a blunted response of signaling pathways and cellular processes during reloading after hind limb suspension in muscles from old rats. Male Brown Norway Fisher 344 rats at 6 (young) and 32 (old) months of age were subjected to normal ambulatory conditions (amb), hind limb suspension for 14 days (HS), and HS followed by reloading through normal ambulation for 14 days (RE); soleus muscles were used for analysis of intracellular signaling pathways and cellular processes. Soleus muscle regrowth was blunted in old compared to young rats which coincided with a recovery of serum IGF-1 and IGFBP-3 levels in young but not old. However, the response to reloading for p-Akt, p-p70s6k and p-GSK3β protein abundance was similar between muscles from young and old rats, even though main effects for age indicate an increase in activation of this protein synthesis pathway in the aged. Similarly, MAFbx mRNA levels in soleus muscle from old rats recovered to the same extent as in the young, while Murf-1 was unchanged. mRNA abundance of autophagy markers Atg5 and Atg7 showed an identical response in muscle from old compared to young rats, but beclin did not. Autophagic flux was not changed at either age at the measured time point. Apoptosis was elevated in soleus muscle from old rats particularly with HS, but recovered in HSRE and these changes were not associated with differences in caspase-3, -8 or -9 activity in any group. Protein abundance of apoptosis repressor with caspase-recruitment domain (ARC), cytosolic EndoG, as well as cytosolic and nuclear apoptosis inducing factor (AIF) were lower in muscle from old rats, and there was no age-related difference in the response to atrophy or regrowth. Soleus muscles from old rats had a higher number of ED2 positive macrophages in all groups and these decreased with HS, but recovered in HSRE in the old, while no changes were observed in the young. Pro-inflammatory cytokines in serum did not show a differential response with age to different loading conditions. Results indicate that at the measured time point the impaired skeletal muscle regrowth after atrophy in aged animals is not associated with a general lack of responsiveness to changes in loading conditions.
Collapse
Affiliation(s)
- Jena R White
- Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, 900 S Limestone, Lexington, KY 40536-0200, USA
| | - Amy L Confides
- Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, 900 S Limestone, Lexington, KY 40536-0200, USA
| | - Stephanie Moore-Reed
- Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, 900 S Limestone, Lexington, KY 40536-0200, USA
| | - Johanna M Hoch
- Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, 900 S Limestone, Lexington, KY 40536-0200, USA
| | - Esther E Dupont-Versteegden
- Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, 900 S Limestone, Lexington, KY 40536-0200, USA.
| |
Collapse
|
18
|
Sakai H, Sagara A, Arakawa K, Sugiyama R, Hirosaki A, Takase K, Jo A, Sato K, Chiba Y, Yamazaki M, Matoba M, Narita M. Mechanisms of cisplatin-induced muscle atrophy. Toxicol Appl Pharmacol 2014; 278:190-9. [DOI: 10.1016/j.taap.2014.05.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 04/23/2014] [Accepted: 05/01/2014] [Indexed: 12/12/2022]
|
19
|
Alcohol consumption and hormonal alterations related to muscle hypertrophy: a review. Nutr Metab (Lond) 2014; 11:26. [PMID: 24932207 PMCID: PMC4056249 DOI: 10.1186/1743-7075-11-26] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 05/24/2014] [Indexed: 01/07/2023] Open
Abstract
Detrimental effects of acute and chronic alcohol (ethanol) consumption on human physiology are well documented in the literature. These adversely influence neural, metabolic, cardiovascular, and thermoregulatory functions. However, the side effects of ethanol consumption on hormonal fluctuations and subsequent related skeletal muscle alterations have received less attention and as such are not entirely understood. The focus of this review is to identify the side effects of ethanol consumption on the major hormones related to muscle metabolism and clarify how the hormonal profiles are altered by such consumption.
Collapse
|
20
|
Gupta VA, Beggs AH. Kelch proteins: emerging roles in skeletal muscle development and diseases. Skelet Muscle 2014; 4:11. [PMID: 24959344 PMCID: PMC4067060 DOI: 10.1186/2044-5040-4-11] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 05/06/2014] [Indexed: 12/11/2022] Open
Abstract
Our understanding of genes that cause skeletal muscle disease has increased tremendously over the past three decades. Advances in approaches to genetics and genomics have aided in the identification of new pathogenic mechanisms in rare genetic disorders and have opened up new avenues for therapeutic interventions by identification of new molecular pathways in muscle disease. Recent studies have identified mutations of several Kelch proteins in skeletal muscle disorders. The Kelch superfamily is one of the largest evolutionary conserved gene families. The 66 known family members all possess a Kelch-repeat containing domain and are implicated in diverse biological functions. In skeletal muscle development, several Kelch family members regulate the processes of proliferation and/or differentiation resulting in normal functioning of mature muscles. Importantly, many Kelch proteins function as substrate-specific adaptors for Cullin E3 ubiquitin ligase (Cul3), a core component of the ubiquitin-proteasome system to regulate the protein turnover. This review discusses the emerging roles of Kelch proteins in skeletal muscle function and disease.
Collapse
Affiliation(s)
- Vandana A Gupta
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave., Boston, MA 02115, USA
| | - Alan H Beggs
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave., Boston, MA 02115, USA
| |
Collapse
|
21
|
Cui Z, Scruggs SB, Gilda JE, Ping P, Gomes AV. Regulation of cardiac proteasomes by ubiquitination, SUMOylation, and beyond. J Mol Cell Cardiol 2014; 71:32-42. [PMID: 24140722 PMCID: PMC3990655 DOI: 10.1016/j.yjmcc.2013.10.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 09/21/2013] [Accepted: 10/10/2013] [Indexed: 10/26/2022]
Abstract
The ubiquitin-proteasome system (UPS) is the major intracellular degradation system, and its proper function is critical to the health and function of cardiac cells. Alterations in cardiac proteasomes have been linked to several pathological phenotypes, including cardiomyopathies, ischemia-reperfusion injury, heart failure, and hypertrophy. Defects in proteasome-dependent cellular protein homeostasis can be causal for the initiation and progression of certain cardiovascular diseases. Emerging evidence suggests that the UPS can specifically target proteins that govern pathological signaling pathways for degradation, thus altering downstream effectors and disease outcomes. Alterations in UPS-substrate interactions in disease occur, in part, due to direct modifications of 19S, 11S or 20S proteasome subunits. Post-translational modifications (PTMs) are one facet of this proteasomal regulation, with over 400 known phosphorylation sites, over 500 ubiquitination sites and 83 internal lysine acetylation sites, as well as multiple sites for caspase cleavage, glycosylation (such as O-GlcNAc modification), methylation, nitrosylation, oxidation, and SUMOylation. Changes in cardiac proteasome PTMs, which occur in ischemia and cardiomyopathies, are associated with changes in proteasome activity and proteasome assembly; however several features of this regulation remain to be explored. In this review, we focus on how some of the less common PTMs affect proteasome function and alter cellular protein homeostasis. This article is part of a Special Issue entitled "Protein Quality Control, the Ubiquitin Proteasome System, and Autophagy".
Collapse
Affiliation(s)
- Ziyou Cui
- Department of Neurobiology, Physiology and Behavior, University of California, Davis CA 95616, USA
| | - Sarah B Scruggs
- Department of Physiology, University of California, Los Angeles, CA 90095, USA
| | - Jennifer E Gilda
- Department of Neurobiology, Physiology and Behavior, University of California, Davis CA 95616, USA
| | - Peipei Ping
- Department of Physiology, University of California, Los Angeles, CA 90095, USA
| | - Aldrin V Gomes
- Department of Neurobiology, Physiology and Behavior, University of California, Davis CA 95616, USA; Department of Physiology and Membrane Biology, University of California, Davis, CA 95616, USA.
| |
Collapse
|
22
|
Jee H, Sakurai T, Lim JY, Hatta H. Changes in αB-crystallin, tubulin, and MHC isoforms by hindlimb unloading show different expression patterns in various hindlimb muscles. J Exerc Nutrition Biochem 2014; 18:161-8. [PMID: 25566451 PMCID: PMC4241918 DOI: 10.5717/jenb.2014.18.2.161] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 05/01/2014] [Accepted: 05/12/2014] [Indexed: 11/09/2022] Open
Abstract
[Purpose] αB-crystallin is a small heat shock protein that acts as a molecular chaperone under various stress conditions. Microtubules, which consist of tubulin, are related to maintain the intracellular organelles and cellular morphology. These two proteins have been shown to be related to the properties of different types of myofibers based on their contractile properties. The response of these proteins during muscular atrophy, which induces a myofibril component change, is not clearly understood. [Methods] We performed 15 days of hindlimb unloading on rats to investigate the transitions of these proteins by analyzing their absolute quantities. Protein contents were analyzed in the soleus, plantaris, and gastrocnemius muscles of the unloading and control groups (N = 6). [Results] All three muscles were significantly atrophied by hindlimb unloading (P < 0.01): soleus (47.5%), plantaris (16.3%), and gastrocnemius (21.3%) compared to each control group. αB-crystallin was significantly reduced in all three examined unloaded hindlimb muscles compared to controls (P < 0.01) during the transition of the myosin heavy chain to fast twitch muscles. α-Tubulin responded only in the unloaded soleus muscle. Muscle atrophy induced the reduction of αB-crystallin and α-tubulin expressions in plantar flexor muscles with a shift to the fast muscle fiber compared to the control. [Conclusion] The novel finding of this study is that both proteins, αB-crystallin and α-tubulin, were downregulated in slow muscles (P < 0.01); However, α-tubulin was not significantly reduced compared to the control in fast muscles (P < 0.01).
Collapse
Affiliation(s)
- Hyunseok Jee
- Seoul National University Bundang Hospital, Gyeonggi-do, Korea ; The University of Tokyo, Tokyo, Japan
| | | | - Jae-Young Lim
- Seoul National University Bundang Hospital, Gyeonggi-do, Korea
| | | |
Collapse
|
23
|
Suryawan A, Davis TA. Regulation of protein degradation pathways by amino acids and insulin in skeletal muscle of neonatal pigs. J Anim Sci Biotechnol 2014; 5:8. [PMID: 24438646 PMCID: PMC3901752 DOI: 10.1186/2049-1891-5-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 01/14/2014] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND The rapid gain in lean mass in neonates requires greater rates of protein synthesis than degradation. We previously delineated the molecular mechanisms by which insulin and amino acids, especially leucine, modulate skeletal muscle protein synthesis and how this changes with development. In the current study, we identified mechanisms involved in protein degradation regulation. In experiment 1, 6- and 26-d-old pigs were studied during 1) euinsulinemic-euglycemic-euaminoacidemic, 2) euinsulinemic-euglycemic-hyperaminoacidemic, and 3) hyperinsulinemic-euglycemic-euaminoacidemic clamps for 2 h. In experiment 2, 5-d-old pigs were studied during 1) euinsulinemic-euglycemic-euaminoacidemic-euleucinemic, 2) euinsulinemic-euglycemic-hypoaminoacidemic-hyperleucinemic, and 3) euinsulinemic-euglycemic-euaminoacidemic-hyperleucinemic clamps for 24 h. We determined in muscle indices of ubiquitin-proteasome, i.e., atrogin-1 (MAFbx) and muscle RING-finger protein-1 (MuRF1) and autophagy-lysosome systems, i.e., unc51-like kinase 1 (UKL1), microtubule-associated protein light chain 3 (LC3), and lysosomal-associated membrane protein 2 (Lamp-2). For comparison, we measured ribosomal protein S6 (rpS6) and eukaryotic initiation factor 4E (eIF4E) activation, components of translation initiation. RESULTS Abundance of atrogin-1, but not MuRF1, was greater in 26- than 6-d-old pigs and was not affected by insulin, amino acids, or leucine. Abundance of ULK1 and LC3 was higher in younger pigs and not affected by treatment. The LC3-II/LC3-I ratio was reduced and ULK1 phosphorylation increased by insulin, amino acids, and leucine. These responses were more profound in younger pigs. Abundance of Lamp-2 was not affected by treatment or development. Abundance of eIF4E, but not rpS6, was higher in 6- than 26-d-old-pigs but unaffected by treatment. Phosphorylation of eIF4E was not affected by treatment, however, insulin, amino acids, and leucine stimulated rpS6 phosphorylation, and the responses decreased with development. CONCLUSIONS The rapid growth of neonatal muscle is in part due to the positive balance between the activation of protein synthesis and degradation signaling. Insulin, amino acids, and, particularly, leucine, act as signals to modulate muscle protein synthesis and degradation in neonates.
Collapse
Affiliation(s)
| | - Teresa A Davis
- United States Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA.
| |
Collapse
|
24
|
Smith RC, Lin BK. Myostatin inhibitors as therapies for muscle wasting associated with cancer and other disorders. Curr Opin Support Palliat Care 2013; 7:352-60. [PMID: 24157714 PMCID: PMC3819341 DOI: 10.1097/spc.0000000000000013] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW This review summarizes recent progress in the development of myostatin inhibitors for the treatment of muscle wasting disorders. It also focuses on findings in myostatin biology that may have implications for the development of antimyostatin therapies. RECENT FINDINGS There has been progress in evaluating antimyostatin therapies in animal models of muscle wasting disorders. Some programs have progressed into clinical development with initial results showing positive impact on muscle volume.In normal mice myostatin deficiency results in enlarged muscles with increased total force but decreased specific force (total force/total mass). An increase in myofibrillar protein synthesis without concomitant satellite cell proliferation and fusion leads to muscle hypertrophy with unchanged myonuclear number. A specific force reduction is not observed when atrophied muscle, the predominant therapeutic target of myostatin inhibitor therapy, is made myostatindeficient.Myostatin has been shown to be expressed by a number of tumor cell lines in mice and man. SUMMARY Myostatin inhibition remains a promising therapeutic strategy for a range of muscle wasting disorders.
Collapse
Affiliation(s)
- Rosamund C Smith
- aBiotechnology Discovery Research bOncology Business Unit, Eli Lilly and Company
| | | |
Collapse
|
25
|
Abstract
Age-related muscle loss impacts on whole-body metabolism and leads to frailty and sarcopenia, which are risk factors for fractures and mortality. Although nutrients are integral to muscle metabolism the relationship between nutrition and muscle loss has only been extensively investigated for protein and amino acids. The objective of the present paper is to describe other aspects of nutrition and their association with skeletal muscle mass. Mechanisms for muscle loss relate to imbalance in protein turnover with a number of anabolic pathways of which the mechanistic TOR pathway and the IGF-1–Akt–FoxO pathways are the most characterised. In terms of catabolism the ubiquitin proteasome system, apoptosis, autophagy, inflammation, oxidation and insulin resistance are among the major mechanisms proposed. The limited research associating vitamin D, alcohol, dietary acid–base load, dietary fat and anti-oxidant nutrients with age-related muscle loss is described. Vitamin D may be protective for muscle loss; a more alkalinogenic diet and diets higher in the anti-oxidant nutrients vitamin C and vitamin E may also prevent muscle loss. Although present recommendations for prevention of sarcopenia focus on protein, and to some extent on vitamin D, other aspects of the diet including fruits and vegetables should be considered. Clearly, more research into other aspects of nutrition and their role in prevention of muscle loss is required.
Collapse
|
26
|
Op den Kamp CM, Langen RC, Snepvangers FJ, de Theije CC, Schellekens JM, Laugs F, Dingemans AMC, Schols AM. Nuclear transcription factor κ B activation and protein turnover adaptations in skeletal muscle of patients with progressive stages of lung cancer cachexia. Am J Clin Nutr 2013; 98:738-48. [PMID: 23902785 DOI: 10.3945/ajcn.113.058388] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Experimental models of cancer cachexia have indicated that systemic inflammation induces muscle-protein breakdown and wasting via muscular nuclear transcription factor κB (NF-κB) activation. This process may limit the efficacy of nutritional intervention. OBJECTIVES We assessed muscle NF-κB activity and protein turnover signaling in progressive stages of clinical lung cancer cachexia and assessed whether circulating factors can induce muscular NF-κB activity. DESIGN Patients with lung cancer precachexia (n = 10) and cachexia (n = 16) were cross-sectionally compared with 22 healthy control subjects. mRNA transcripts of muscle proteolytic (ubiquitin proteasome system and autophagy lysosomal pathway) and myogenic markers and protein expression of PI3K/Akt, myostatin, and autophagy signaling were measured. A multiplex analysis showed the systemic inflammatory status, whereas plasma exposure to stable NF-κB-luciferase-reporter muscle cells revealed NF-κB inducibility. RESULTS Compared with healthy control subjects, cachectic patients had reduced (appendicular) muscle mass (-10%), muscle fiber atrophy (-27%), and decreased quadriceps strength (-31%). Subtle alterations in the muscle morphology were also detectable in precachectic patients, without changes in body composition. Despite increased Akt phosphorylation, downstream phosphosubstrates glycogen synthase kinase 3β, mammalian target of rapamycin, and Forkhead box protein were unaltered. The expression of autophagy effectors B cell lymphoma 2/adenovirus E1B 19-kDa protein-interacting protein 3 and microtubule-associated proteins 1A/1B light chain 3B gradually increased from precachectic to cachectic patients, without differences in E3 ubiquitin ligases. Systemic and local inflammation was evident in cachexia and intermediate in precachexia, but the plasma of both patients groups caused ex vivo muscle NF-κB activation. CONCLUSIONS In lung cancer, muscular NF-κB activity is induced by factors contained within the circulation. Autophagy may contribute to increased muscle proteolysis in lung cancer cachexia, whereas the absence of downstream changes in phosphosubstrates despite increased Akt phosphorylation suggests impaired anabolic signaling that may require targeted nutritional intervention.
Collapse
Affiliation(s)
- Céline M Op den Kamp
- Department of Respiratory Medicine, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, Maastricht, Netherlands.
| | | | | | | | | | | | | | | |
Collapse
|