1
|
Yadav A, Dabur R. Skeletal muscle atrophy after sciatic nerve damage: Mechanistic insights. Eur J Pharmacol 2024; 970:176506. [PMID: 38492879 DOI: 10.1016/j.ejphar.2024.176506] [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: 01/08/2024] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 03/18/2024]
Abstract
Sciatic nerve injury leads to molecular events that cause muscular dysfunction advancement in atrophic conditions. Nerve damage renders muscles permanently relaxed which elevates intracellular resting Ca2+ levels. Increased Ca2+ levels are associated with several cellular signaling pathways including AMPK, cGMP, PLC-β, CERB, and calcineurin. Also, multiple enzymes involved in the tricarboxylic acid cycle and oxidative phosphorylation are activated by Ca2+ influx into mitochondria during muscle contraction, to meet increased ATP demand. Nerve damage induces mitophagy and skeletal muscle atrophy through increased sensitivity to Ca2+-induced opening of the permeability transition pore (PTP) in mitochondria attributed to Ca2+, ROS, and AMPK overload in muscle. Activated AMPK interacts negatively with Akt/mTOR is a highly prevalent and well-described central pathway for anabolic processes. Over the decade several reports indicate abnormal behavior of signaling machinery involved in denervation-induced muscle loss but end up with some controversial outcomes. Therefore, understanding how the synthesis and inhibitory stimuli interact with cellular signaling to control muscle mass and morphology may lead to new pharmacological insights toward understanding the underlying mechanism of muscle loss after sciatic nerve damage. Hence, the present review summarizes the existing literature on denervation-induced muscle atrophy to evaluate the regulation and expression of differential regulators during sciatic damage.
Collapse
Affiliation(s)
- Aarti Yadav
- Clinical Biochemistry Laboratory, Department of Biochemistry, Maharshi Dayanand University, Rohtak, 124001, Haryana, India
| | - Rajesh Dabur
- Clinical Biochemistry Laboratory, Department of Biochemistry, Maharshi Dayanand University, Rohtak, 124001, Haryana, India.
| |
Collapse
|
2
|
Muacevic A, Adler JR, Torres R, Maita K, Garcia J, Serrano L, Ho O, Forte AJ. Modulation of Burn Hypermetabolism in Preclinical Models. Cureus 2023; 15:e33518. [PMID: 36779088 PMCID: PMC9904913 DOI: 10.7759/cureus.33518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/08/2023] [Indexed: 01/11/2023] Open
Abstract
Severe burns elicit a state of physiological stress and increased metabolism to help the body compensate for the changes associated with the traumatic injury. However, this hypermetabolic state is associated with increased insulin resistance, cardiovascular dysfunction, skeletal muscle catabolism, impaired wound healing, and delayed recovery. Several interventions were attempted to modulate burn hypermetabolism, including nutritional support, early excision and grafting, and growth hormone application. However, burn hypermetabolism still imposes significant morbidity and mortality in burn patients. Due to the limitations of in vitro models, animal models are indispensable in burn research. Animal models provide researchers with invaluable tools to test the safety and efficacy of novel treatments or advance our knowledge of previously utilized agents. Several animal studies evaluated novel therapies to modulate burn hypermetabolism in the last few years, including recombinant human growth hormone, erythropoietin, acipimox, apelin, anti-interleukin-6 monoclonal antibody, and ghrelin therapies. Results from these studies are promising and may be effectively translated into human studies. In addition, other studies revisited drugs previously used in clinical practice, such as insulin and metformin, to further investigate their underlying mechanisms as modulators of burn hypermetabolism. This review aims to update burn experts with the novel therapies under investigation in burn hypermetabolism with a focus on applicability and translation. Furthermore, we aim to guide researchers in selecting the correct animal model for their experiments by providing a summary of the methodology and the rationale of the latest studies.
Collapse
|
3
|
Antagonization of Ghrelin Suppresses Muscle Protein Deposition by Altering Gut Microbiota and Serum Amino Acid Composition in a Pig Model. BIOLOGY 2022; 11:biology11060840. [PMID: 35741361 PMCID: PMC9220191 DOI: 10.3390/biology11060840] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/23/2022] [Accepted: 05/23/2022] [Indexed: 01/03/2023]
Abstract
Simple Summary This study investigated the effects of the antagonization of ghrelin on muscle protein deposition, eating patterns and gut microbiota in pigs by injecting ghrelin antagonist ([D-Lys3]-GHRP-6) in a short term. We found that the antagonization of ghrelin affected the eating patterns of animals, which resulted in changes in the absorption of amino acids and gut microbiota, and it reduced protein deposition in muscles. We emphasize the important role of ghrelin in promoting muscle protein deposition and provide new clues for future research on improving muscle loss. Abstract Ghrelin is an appetite-stimulating hormone that can increase food intake and has been reported to prevent muscle loss; however, the mechanism is not yet fully understood. In this study, [D-Lys3]-GHRP-6 (GHRP) was used to investigate the effects of the antagonization of ghrelin on muscle protein deposition, eating patterns and gut microbiota in a pig model. We found that the growth performance and muscle fiber cross-sectional area of pigs treated with GHRP were significantly reduced compared with the control (CON) group. Moreover, the levels of serum isoleucine, methionine, arginine and tyrosine in the GHRP group were lower than that of the CON group. The abundance of acetate-producing bacteria (Oscillospiraceae UCG-005, Parabacteroides and Oscillospiraceae NK4A214 group) and acetate concentration in the colons of pigs treated with GHRP were significantly reduced. In addition, the injection of GHRP down-regulated the mRNA expression of MCT-1 and mTOR, and it up-regulated the mRNA expression of HDAC1, FOXO1 and Beclin-1. In summary, the antagonization of ghrelin reduced the concentration of important signal molecules (Arg, Met and Ile) that activate the mTOR pathway, concurrently reduce the concentration of HDAC inhibitors (acetate), promote autophagy and finally reduce protein deposition in muscles.
Collapse
|
4
|
Villarreal D, Pradhan G, Zhou Y, Xue B, Sun Y. Diverse and Complementary Effects of Ghrelin and Obestatin. Biomolecules 2022; 12:biom12040517. [PMID: 35454106 PMCID: PMC9028691 DOI: 10.3390/biom12040517] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/21/2022] [Accepted: 03/25/2022] [Indexed: 02/06/2023] Open
Abstract
Ghrelin and obestatin are two “sibling proteins” encoded by the same preproghrelin gene but possess an array of diverse and complex functions. While there are ample literature documenting ghrelin’s functions, the roles of obestatin are less clear and controversial. Ghrelin and obestatin have been perceived to be antagonistic initially; however, recent studies challenge this dogma. While they have opposing effects in some systems, they function synergistically in other systems, with many functions remaining debatable. In this review, we discuss their functional relationship under three “C” categories, namely complex, complementary, and contradictory. Their functions in food intake, weight regulation, hydration, gastrointestinal motility, inflammation, and insulin secretion are complex. Their functions in pancreatic beta cells, cardiovascular, muscle, neuroprotection, cancer, and digestive system are complementary. Their functions in white adipose tissue, thermogenesis, and sleep regulation are contradictory. Overall, this review accumulates the multifaceted functions of ghrelin and obestatin under both physiological and pathological conditions, with the intent of contributing to a better understanding of these two important gut hormones.
Collapse
Affiliation(s)
- Daniel Villarreal
- Department of Nutrition, Texas A & M University, College Station, TX 77843, USA;
| | - Geetali Pradhan
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA;
- Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yu Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao 266071, China;
| | - Bingzhong Xue
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA;
| | - Yuxiang Sun
- Department of Nutrition, Texas A & M University, College Station, TX 77843, USA;
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA;
- Correspondence: ; Tel.: +1-979-862-9143
| |
Collapse
|
5
|
Peris-Moreno D, Cussonneau L, Combaret L, Polge C, Taillandier D. Ubiquitin Ligases at the Heart of Skeletal Muscle Atrophy Control. Molecules 2021; 26:molecules26020407. [PMID: 33466753 PMCID: PMC7829870 DOI: 10.3390/molecules26020407] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/08/2021] [Accepted: 01/10/2021] [Indexed: 02/07/2023] Open
Abstract
Skeletal muscle loss is a detrimental side-effect of numerous chronic diseases that dramatically increases mortality and morbidity. The alteration of protein homeostasis is generally due to increased protein breakdown while, protein synthesis may also be down-regulated. The ubiquitin proteasome system (UPS) is a master regulator of skeletal muscle that impacts muscle contractile properties and metabolism through multiple levers like signaling pathways, contractile apparatus degradation, etc. Among the different actors of the UPS, the E3 ubiquitin ligases specifically target key proteins for either degradation or activity modulation, thus controlling both pro-anabolic or pro-catabolic factors. The atrogenes MuRF1/TRIM63 and MAFbx/Atrogin-1 encode for key E3 ligases that target contractile proteins and key actors of protein synthesis respectively. However, several other E3 ligases are involved upstream in the atrophy program, from signal transduction control to modulation of energy balance. Controlling E3 ligases activity is thus a tempting approach for preserving muscle mass. While indirect modulation of E3 ligases may prove beneficial in some situations of muscle atrophy, some drugs directly inhibiting their activity have started to appear. This review summarizes the main signaling pathways involved in muscle atrophy and the E3 ligases implicated, but also the molecules potentially usable for future therapies.
Collapse
|
6
|
Quintana HT, Baptista VIDA, Lazzarin MC, Antunes HKM, Le Sueur-Maluf L, de Oliveira CAM, de Oliveira F. Insulin Modulates Myogenesis and Muscle Atrophy Resulting From Skin Scald Burn in Young Male Rats. J Surg Res 2020; 257:56-68. [PMID: 32818785 DOI: 10.1016/j.jss.2020.07.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 06/18/2020] [Accepted: 07/07/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Burn injuries (BIs) due to scalding are one of the most common accidents among children. BIs greater than 40% of total body surface area are considered extensive and result in local and systemic response. We sought to assess morphological and myogenic mechanisms through both short- and long-term intensive insulin therapies that affect the skeletal muscle after extensive skin BI in young rats. MATERIALS AND METHODS Wistar rats aged 21 d were distributed into four groups: control (C), control with insulin (C + I), scald burn injury (SI), and SI with insulin (SI + I). The SI groups were submitted to a 45% total body surface area burn, and the C + I and SI + I groups received insulin (5 UI/Kg/d) for 4 or 14 d. Glucose tolerance and the homeostatic model assessment of insulin resistance index were determined. Gastrocnemius muscles were analyzed for histopathological, morphometric, and immunohistochemical myogenic parameters (Pax7, MyoD, and MyoG); in addition, the expression of genes related to muscle atrophy (MuRF1 and MAFbx) and its regulation (IGF-1) were also assessed. RESULTS Short-term treatment with insulin favored muscle regeneration by primary myogenesis and decreased muscle atrophy in animals with BIs, whereas the long-term treatment modulated myogenesis by increasing the MyoD protein. Both treatments improved histopathological parameters and secondary myogenesis by increasing the MyoG protein. CONCLUSIONS Treatment with insulin benefits myogenic parameters during regeneration and modulates MuRF1, an important mediator of muscle atrophy.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Flavia de Oliveira
- Departamento de Biociências, Universidade Federal de São Paulo, Santos, SP, Brazil.
| |
Collapse
|
7
|
Duan K, Gao X, Zhu D. The clinical relevance and mechanism of skeletal muscle wasting. Clin Nutr 2020; 40:27-37. [PMID: 32788088 DOI: 10.1016/j.clnu.2020.07.029] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 06/15/2020] [Accepted: 07/21/2020] [Indexed: 02/08/2023]
Abstract
Skeletal muscle wasting occurs in both chronic and acute diseases. Increasing evidence has shown this debilitating process is associated with short- and long-term outcomes in critical, cancer and surgical patients. Both muscle quantity and quality, as reflected by the area and density of a given range of attenuation in CT scan, impact the patient prognosis. In addition, ultrasound and bioelectrical impedance analysis (BIA) are also widely used in the assessment of body composition due to their bedside viability and no radioactivity. Mechanism researches have revealed complicated pathways are involved in muscle wasting, which include altered IGF1-Akt-FoxO signaling, elevated levels of myostatin and activin A, activation of NF-κB pathway and glucocorticoid effects. Particularly, central nervous system (CNS) has been proven to participate in regulating muscle wasting in various conditions, such as infection and tumor. Several promising therapeutic agents have been under developing in the treatment of muscle atrophy, such as myostatin antagonist, ghrelin analog, non-steroidal selective androgen receptor modulators (SARMs). Notably, nutritional therapy is still the fundamental support in combating muscle wasting. However, the optimizing and tailored nutrition regimen relies on accurate metabolism measurement and large clinical trials in the future. Here, we will discuss the current understanding of muscle wasting and potential treatment in clinical practice.
Collapse
Affiliation(s)
- Kaipeng Duan
- Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006, PR China
| | - Xin Gao
- Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006, PR China
| | - Dongming Zhu
- Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006, PR China.
| |
Collapse
|
8
|
Wu CS, Wei Q, Wang H, Kim DM, Balderas M, Wu G, Lawler J, Safe S, Guo S, Devaraj S, Chen Z, Sun Y. Protective Effects of Ghrelin on Fasting-Induced Muscle Atrophy in Aging Mice. J Gerontol A Biol Sci Med Sci 2020; 75:621-630. [PMID: 30407483 PMCID: PMC7328200 DOI: 10.1093/gerona/gly256] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Indexed: 12/12/2022] Open
Abstract
Sarcopenia is the aging-associated progressive loss of skeletal muscle; however, the pathogenic mechanism of sarcopenia is not clear. The orexigenic hormone ghrelin stimulates growth hormone secretion, increases food intake, and promotes adiposity. Here we showed that fasting-induced muscle loss was exacerbated in old ghrelin-null (Ghrl-/-) mice, exhibiting decreased expression of myogenic regulator MyoD and increased expression of protein degradation marker MuRF1, as well as altered mitochondrial function. Moreover, acylated ghrelin and unacylated ghrelin treatments significantly increased mitochondrial respiration capacity in muscle C2C12 cells. Consistently, acylated ghrelin and unacylated ghrelin treatments effectively increased myogenic genes and decreased degradation genes in the muscle in fasted old Ghrl-/- mice, possibly by stimulating insulin and adenosine monophosphate-activated protein kinase pathways. Furthermore, Ghrl-/- mice showed a profile of pro-inflammatory gut microbiota, exhibiting reduced butyrate-producing bacteria Roseburia and ClostridiumXIVb. Collectively, our results showed that ghrelin has a major role in the maintenance of aging muscle via both muscle-intrinsic and -extrinsic mechanisms. Acylated ghrelin and unacylated ghrelin enhanced muscle anabolism and exerted protective effects for muscle atrophy. Because unacylated ghrelin is devoid of the obesogenic side effect seen with acylated ghrelin, it represents an attractive therapeutic option for sarcopenia.
Collapse
Affiliation(s)
- Chia-Shan Wu
- Department of Nutrition and Food Science, Texas A&M University, College Station
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Qiong Wei
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
- Division of Endocrinology, Zhongda Hospital, Southeast University, Nanjing, Jiangsu Province
| | - Hongying Wang
- Department of Nutrition and Food Science, Texas A&M University, College Station
- Laboratory of Lipid and Glucose Metabolism, The First Affiliated Hospital of Chongqing Medical University, China
| | - Da Mi Kim
- Department of Nutrition and Food Science, Texas A&M University, College Station
| | - Miriam Balderas
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas
| | - Guoyao Wu
- Department of Animal Science, Texas A&M University, College Station
| | - John Lawler
- Department of Health and Kinesiology, Texas A&M University, College Station
| | - Stephen Safe
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station
| | - Shaodong Guo
- Department of Nutrition and Food Science, Texas A&M University, College Station
| | - Sridevi Devaraj
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas
| | - Zheng Chen
- The University of Texas Health Science Center at Houston
| | - Yuxiang Sun
- Department of Nutrition and Food Science, Texas A&M University, College Station
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| |
Collapse
|
9
|
Grannell A, De Vito G, Murphy JC, le Roux CW. The influence of skeletal muscle on appetite regulation. Expert Rev Endocrinol Metab 2019; 14:267-282. [PMID: 31106601 DOI: 10.1080/17446651.2019.1618185] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 05/09/2019] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Fat-free mass, of which skeletal muscle is amajor component, correlates positively with energy intake at energy balance. This is due to the effects of metabolically active tissue on energy expenditure which in itself appears to signal to the brain adrive to eat to ensure cellular energy homeostasis. The mechanisms responsible for this drive to eat are unknown but are likely to be related to energy utilization. Here muscle imparts an indirect influence on hunger. The drive to eat is also enhanced after muscle loss secondary to intentional weight loss. The evidence suggests loss of both fat mass and skeletal muscle mass directly influences the trajectory and magnitude of weight regain highlighting their potential role in long-termappetite control. The mechanisms responsible for the potential direct drive to eat stemming from muscle loss are unknown. AREAS COVERED The literature pertaining to muscle and appetite at energy balance and after weight loss was examined. Aliterature search was conducted to identify studies related to appetite, muscle, exercise, and weight loss. EXPERT OPINION Understanding the mechanisms which link energy expenditure and muscle loss to hunger has the potential to positively impact both the prevention and the treatment of obesity.
Collapse
Affiliation(s)
- Andrew Grannell
- a Diabetes Complications Research Centre, Conway Institute, School of Medicine and Medical Sciences , University College Dublin , Dublin , Ireland
- b MedFit Proactive Healthcare, Blackrock , Dublin , Ireland
| | - Giuseppe De Vito
- c School of Public Health, Physiotherapy and Sports Science , University College Dublin , Dublin , Ireland
| | - John C Murphy
- b MedFit Proactive Healthcare, Blackrock , Dublin , Ireland
| | - Carel W le Roux
- a Diabetes Complications Research Centre, Conway Institute, School of Medicine and Medical Sciences , University College Dublin , Dublin , Ireland
| |
Collapse
|
10
|
Goshadrou F, Arefi Oskouie A, Eslami M, Nobakht Mothlagh Ghoochani BF. Effect of ghrelin on serum metabolites in Alzheimer's disease model rats; a metabolomics studies based on 1H-NMR technique. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2018; 21:1245-1254. [PMID: 30627368 PMCID: PMC6312673 DOI: 10.22038/ijbms.2018.30596.7373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 06/21/2018] [Indexed: 11/06/2022]
Abstract
OBJECTIVES Alzheimer's disease (AD) is dysfunction of the central nervous system and as a neurodegenerative disease. The objective of this work is to investigate metabolic profiling in the serum of animal models of AD compared to healthy controls and then to peruse the role of ghrelin as a therapeutic approach for the AD. MATERIALS AND METHODS Nuclear magnetic resonance (NMR) technique was used for identification of metabolites that are differentially expressed in the serum of a rat model of the AD with or without ghrelin treatment. Using multivariate statistical analysis, models were built and indicated. RESULTS There were significant differences and high predictive power between AD and ghrelin-treated groups. The area under curve (AUC) of receiver operating characteristic (ROC) curve and Q2 were 0.870 and 0.759, respectively. A biomarker panel consisting of 14 metabolites was identified to discriminate the AD from the control group. Another panel of 12 serum metabolites was used to differentiate AD models from treated models. CONCLUSION Both panels had good agreements with clinical diagnosis. Analysis of the results displayed that ghrelin improved memory and cognitive abilities. Affected pathways by ghrelin included oxidative stress, and osteoporosis pathways and vascular risk factors.
Collapse
Affiliation(s)
- Fatemeh Goshadrou
- Faculty of Paramedical Sciences, Department of Basic Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Afsaneh Arefi Oskouie
- Faculty of Paramedical Sciences, Department of Basic Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Eslami
- Department of Physiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | | |
Collapse
|
11
|
Angelino E, Reano S, Bollo A, Ferrara M, De Feudis M, Sustova H, Agosti E, Clerici S, Prodam F, Tomasetto CL, Graziani A, Filigheddu N. Ghrelin knockout mice display defective skeletal muscle regeneration and impaired satellite cell self-renewal. Endocrine 2018; 62:129-135. [PMID: 29846901 DOI: 10.1007/s12020-018-1606-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 04/15/2018] [Indexed: 12/18/2022]
Abstract
PURPOSE Muscle regeneration depends on satellite cells (SCs), quiescent precursors that, in consequence of injury or pathological states such as muscular dystrophies, activate, proliferate, and differentiate to repair the damaged tissue. A subset of SCs undergoes self-renewal, thus preserving the SC pool and its regenerative potential. The peptides produced by the ghrelin gene, i.e., acylated ghrelin (AG), unacylated ghrelin (UnAG), and obestatin (Ob), affect skeletal muscle biology in several ways, not always with overlapping effects. In particular, UnAG and Ob promote SC self-renewal and myoblast differentiation, thus fostering muscle regeneration. METHODS To delineate the endogenous contribution of preproghrelin in muscle regeneration, we evaluated the repair process in Ghrl-/- mice upon CTX-induced injury. RESULTS Although muscles from Ghrl-/- mice do not visibly differ from WT muscles in term of weight, structure, and SCs content, muscle regeneration after CTX-induced injury is impaired in Ghrl-/- mice, indicating that ghrelin-derived peptides actively participate in muscle repair. Remarkably, the lack of ghrelin gene impacts SC self-renewal during regeneration. CONCLUSIONS Although we cannot discern the specific Ghrl-derived peptide responsible for such activities, these data indicate that Ghrl contributes to a proper muscle regeneration.
Collapse
Affiliation(s)
- Elia Angelino
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
- Università Vita-Salute San Raffaele, Milano, Italy
| | - Simone Reano
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - Alessandro Bollo
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
- Università Vita-Salute San Raffaele, Milano, Italy
| | - Michele Ferrara
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
- Università Vita-Salute San Raffaele, Milano, Italy
| | - Marilisa De Feudis
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - Hana Sustova
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - Emanuela Agosti
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - Sara Clerici
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
- Università Vita-Salute San Raffaele, Milano, Italy
| | - Flavia Prodam
- Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | - Catherine-Laure Tomasetto
- IGBMC - Institut de Génétique et de Biologie Moléculaire et Cellulaire - Université de Strasbourg, Illkirch, France
| | - Andrea Graziani
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy.
- Università Vita-Salute San Raffaele, Milano, Italy.
| | - Nicoletta Filigheddu
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy.
| |
Collapse
|
12
|
Asprosin: Possible target in connection with ghrelin and cytokine network expression in the post-burn treatment. Med Hypotheses 2018; 118:163-168. [DOI: 10.1016/j.mehy.2018.07.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 05/29/2018] [Accepted: 07/05/2018] [Indexed: 12/14/2022]
|
13
|
Balasubramaniam A, Sheriff S, Friend LA, James JH. Phosphodiesterase 4B knockout prevents skeletal muscle atrophy in rats with burn injury. Am J Physiol Regul Integr Comp Physiol 2018; 315:R429-R433. [PMID: 29693432 DOI: 10.1152/ajpregu.00042.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The phosphodiesterase 4 (PDE4)-cAMP pathway plays a predominant role in mediating skeletal muscle proteolysis in burn injury. The present investigations to determine the PDE4 isoform(s) involved in this action revealed that burn injury increased the expression of rat skeletal muscle PDE4B mRNA by sixfold but had little or no effect on expression of other PDE4 isoforms. These observations led us to study the effects of burn in PDE4B knockout (KO) rats. As reported by us previously, burn injury significantly increased extensor digitorum longus (EDL) muscle total and myofibrillar proteolysis in wild-type (WT) rats, but there were no significant effects on either total or myofibrillar protein breakdown in EDL muscle of PDE4B KO rats with burn injury. Moreover, burn injury increased PDE4 activity in the skeletal muscle of WT rats, but this was reduced by >80% in PDE4B KO rats. Also, burn injury decreased skeletal muscle cAMP concentration in WT rats but had no significant effects in the muscles of PDE4B KO rats. Incubation of the EDL muscle of burn-PDE4B KO rats with an inhibitor of the exchange factor directly activated by cAMP, but not with a protein kinase A inhibitor, eliminated the protective effects of PDE4B KO on EDL muscle proteolysis and increased muscle proteolysis to the same extent as in the EDL of burn-WT rats. These novel findings confirm a major role for PDE4B in skeletal muscle proteolysis in burn injury and suggest that an innovative therapy based on PDE4B-selective inhibitors could be developed to treat skeletal muscle cachexia in burn injury without the fear of causing emesis, which is associated with PDE4D inhibition.
Collapse
Affiliation(s)
- Ambikaipakan Balasubramaniam
- Department of Surgery, University of Cincinnati Medical Center , Cincinnati, Ohio.,Shriner's Hospital for Children , Cincinnati, Ohio
| | - Sulaiman Sheriff
- Department of Surgery, University of Cincinnati Medical Center , Cincinnati, Ohio
| | - Lou Ann Friend
- Department of Surgery, University of Cincinnati Medical Center , Cincinnati, Ohio
| | | |
Collapse
|
14
|
Z-505 hydrochloride, an orally active ghrelin agonist, attenuates the progression of cancer cachexia via anabolic hormones in Colon 26 tumor-bearing mice. Eur J Pharmacol 2017; 811:30-37. [DOI: 10.1016/j.ejphar.2017.05.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 05/12/2017] [Accepted: 05/17/2017] [Indexed: 11/20/2022]
|
15
|
Impact of ghrelin on body composition and muscle function in a long-term rodent model of critical illness. PLoS One 2017; 12:e0182659. [PMID: 28796827 PMCID: PMC5552127 DOI: 10.1371/journal.pone.0182659] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 07/22/2017] [Indexed: 01/14/2023] Open
Abstract
Background Patients with multiple injuries or sepsis requiring intensive care treatment invariably develop a catabolic state with resultant loss of lean body mass, for which there are currently no effective treatments. Recovery can take months and mortality is high. We hypothesise that treatment with the orexigenic and anti-inflammatory gastric hormone, ghrelin may attenuate the loss of body mass following critical illness and improve recovery. Methods Male Wistar rats received an intraperitoneal injection of the fungal cell wall derivative zymosan to induce a prolonged peritonitis and consequent critical illness. Commencing at 48h after zymosan, animals were randomised to receive a continuous infusion of ghrelin or vehicle control using a pre-implanted subcutaneous osmotic mini-pump, and continued for 10 days. Results Zymosan peritonitis induced significant weight loss and reduced food intake with a nadir at Day 2 and gradual recovery thereafter. Supra-physiologic plasma ghrelin levels were achieved in the treated animals. Ghrelin-treated rats ate more food and gained more body mass than controls. Ghrelin increased adiposity and promoted carbohydrate over fat metabolism, but did not alter total body protein, muscle strength nor muscle morphology. Muscle mass and strength remained significantly reduced in all zymosan-treated animals, even at ten days post-insult. Conclusions Continuous infusion of ghrelin increased body mass and food intake, but did not increase muscle mass nor improve muscle function, in a long-term critical illness recovery model. Further studies with pulsatile ghrelin delivery or additional anabolic stimuli may further clarify the utility of ghrelin in survivors of critical illness.
Collapse
|
16
|
Colldén G, Tschöp MH, Müller TD. Therapeutic Potential of Targeting the Ghrelin Pathway. Int J Mol Sci 2017; 18:ijms18040798. [PMID: 28398233 PMCID: PMC5412382 DOI: 10.3390/ijms18040798] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/03/2017] [Accepted: 04/06/2017] [Indexed: 02/07/2023] Open
Abstract
Ghrelin was discovered in 1999 as the endogenous ligand of the growth-hormone secretagogue receptor 1a (GHSR1a). Since then, ghrelin has been found to exert a plethora of physiological effects that go far beyond its initial characterization as a growth hormone (GH) secretagogue. Among the numerous well-established effects of ghrelin are the stimulation of appetite and lipid accumulation, the modulation of immunity and inflammation, the stimulation of gastric motility, the improvement of cardiac performance, the modulation of stress, anxiety, taste sensation and reward-seeking behavior, as well as the regulation of glucose metabolism and thermogenesis. Due to a variety of beneficial effects on systems’ metabolism, pharmacological targeting of the endogenous ghrelin system is widely considered a valuable approach to treat metabolic complications, such as chronic inflammation, gastroparesis or cancer-associated anorexia and cachexia. The aim of this review is to discuss and highlight the broad pharmacological potential of ghrelin pathway modulation for the treatment of anorexia, cachexia, sarcopenia, cardiopathy, neurodegenerative disorders, renal and pulmonary disease, gastrointestinal (GI) disorders, inflammatory disorders and metabolic syndrome.
Collapse
Affiliation(s)
- Gustav Colldén
- Institute for Diabetes and Obesity & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany.
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany.
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, 80333 Munich, Germany.
| | - Timo D Müller
- Institute for Diabetes and Obesity & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany.
- Institute for Diabetes and Obesity (IDO), Business Campus Garching-Hochbrück, Parkring 13, 85748 Garching, Germany.
| |
Collapse
|
17
|
Nakazawa H, Chang K, Shinozaki S, Yasukawa T, Ishimaru K, Yasuhara S, Yu YM, Martyn JAJ, Tompkins RG, Shimokado K, Kaneki M. iNOS as a Driver of Inflammation and Apoptosis in Mouse Skeletal Muscle after Burn Injury: Possible Involvement of Sirt1 S-Nitrosylation-Mediated Acetylation of p65 NF-κB and p53. PLoS One 2017; 12:e0170391. [PMID: 28099528 PMCID: PMC5242494 DOI: 10.1371/journal.pone.0170391] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 01/04/2017] [Indexed: 01/28/2023] Open
Abstract
Inflammation and apoptosis develop in skeletal muscle after major trauma, including burn injury, and play a pivotal role in insulin resistance and muscle wasting. We and others have shown that inducible nitric oxide synthase (iNOS), a major mediator of inflammation, plays an important role in stress (e.g., burn)-induced insulin resistance. However, it remains to be determined how iNOS induces insulin resistance. Moreover, the interrelation between inflammatory response and apoptosis is poorly understood, although they often develop simultaneously. Nuclear factor (NF)-κB and p53 are key regulators of inflammation and apoptosis, respectively. Sirt1 inhibits p65 NF-κB and p53 by deacetylating these transcription factors. Recently, we have shown that iNOS induces S-nitrosylation of Sirt1, which inactivates Sirt1 and thereby increases acetylation and activity of p65 NF-κB and p53 in various cell types, including skeletal muscle cells. Here, we show that iNOS enhances burn-induced inflammatory response and apoptotic change in mouse skeletal muscle along with S-nitrosylation of Sirt1. Burn injury induced robust expression of iNOS in skeletal muscle and gene disruption of iNOS significantly inhibited burn-induced increases in inflammatory gene expression and apoptotic change. In parallel, burn increased Sirt1 S-nitrosylation and acetylation and DNA-binding capacity of p65 NF-κB and p53, all of which were reversed or ameliorated by iNOS deficiency. These results indicate that iNOS functions not only as a downstream effector but also as an upstream enhancer of burn-induced inflammatory response, at least in part, by Sirt1 S-nitrosylation-dependent activation (acetylation) of p65 NF-κB. Our data suggest that Sirt1 S-nitrosylation may play a role in iNOS-mediated enhanced inflammatory response and apoptotic change, which, in turn, contribute to muscle wasting and supposedly to insulin resistance after burn injury.
Collapse
Affiliation(s)
- Harumasa Nakazawa
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
- Shriners Hospitals for Children, Boston, Massachusetts, United States of America
| | - Kyungho Chang
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Shohei Shinozaki
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
- Department of Geriatrics and Vascular Medicine, Tokyo Medical and Dental University Graduate School, Tokyo, Japan
| | - Takashi Yasukawa
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
- Shriners Hospitals for Children, Boston, Massachusetts, United States of America
| | - Kazuhiro Ishimaru
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
- Shriners Hospitals for Children, Boston, Massachusetts, United States of America
| | - Shingo Yasuhara
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
- Shriners Hospitals for Children, Boston, Massachusetts, United States of America
| | - Yong-Ming Yu
- Shriners Hospitals for Children, Boston, Massachusetts, United States of America
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - J. A. Jeevendra Martyn
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
- Shriners Hospitals for Children, Boston, Massachusetts, United States of America
| | - Ronald. G. Tompkins
- Shriners Hospitals for Children, Boston, Massachusetts, United States of America
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kentaro Shimokado
- Department of Geriatrics and Vascular Medicine, Tokyo Medical and Dental University Graduate School, Tokyo, Japan
| | - Masao Kaneki
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
- Shriners Hospitals for Children, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
18
|
Hypothalamic activation is essential for endotoxemia-induced acute muscle wasting. Sci Rep 2016; 6:38544. [PMID: 27922103 PMCID: PMC5138608 DOI: 10.1038/srep38544] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 11/10/2016] [Indexed: 01/04/2023] Open
Abstract
Growing evidence suggests acute skeletal muscle wasting is a key factor affecting nutritional support and prognosis in critical patients. Previously, plenty of studies of muscle wasting focused on the peripheral pathway, little was known about the central role. We tested the hypothesis whether central inflammatory pathway and neuropeptides were involved in the process. In lipopolysaccharide (LPS) treated rats, hypothalamic NF-κB pathway and inflammation were highly activated, which was accompanied with severe muscle wasting. Central inhibition of nuclear factor kappa-B (NF-κB) pathway activation by infusion of an inhibitor (PS1145) can efficiently reduce muscle wasting as well as attenuate hypothalamic neuropeptides alteration. Furthermore, knockdown the expression of anorexigenic neuropeptide proopiomelanocortin (POMC) expression with a lentiviral vector containing shRNA can significantly alleviate LPS-induced muscle wasting, whereas hypothalamic inflammation or NF-κB pathway was barely affected. Taken together, these results suggest activation of hypothalamic POMC is pivotal for acute muscle wasting caused by endotoxemia. Neuropeptide POMC expression may have mediated the contribution of hypothalamic inflammation to peripheral muscle wasting. Pharmaceuticals with the ability of inhibiting hypothalamic NF-κB pathway or POMC activation may have a therapeutic potential for acute muscle wasting and nutritional therapy in septic patients.
Collapse
|
19
|
Ghrelin accelerates wound healing through GHS-R1a-mediated MAPK-NF-κB/GR signaling pathways in combined radiation and burn injury in rats. Sci Rep 2016; 6:27499. [PMID: 27271793 PMCID: PMC4895129 DOI: 10.1038/srep27499] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 05/19/2016] [Indexed: 11/08/2022] Open
Abstract
The therapeutic effect of ghrelin on wound healing was assessed using a rat model of combined radiation and burn injury (CRBI). Rat ghrelin, anti-rat tumor necrosis factor (TNF) α polyclonal antibody (PcAb), or selective antagonists of p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), and growth hormone secretagogue receptor (GHS-R) 1a (SB203580, SP600125, and [D-Lys3]-GHRP-6, respectively), were administered for seven consecutive days. Levels of various signaling molecules were assessed in isolated rat peritoneal macrophages. The results showed that serum ghrelin levels and levels of macrophage glucocorticoid receptor (GR) decreased, while phosphorylation of p38MAPK, JNK, and p65 nuclear factor (NF) κB increased. Ghrelin inhibited the serum induction of proinflammatory mediators, especially TNF-α, and promoted wound healing in a dose-dependent manner. Ghrelin treatment decreased phosphorylation of p38MAPK, JNK, and p65NF-κB, and increased GR levels in the presence of GHS-R1a. SB203580 or co-administration of SB203580 and SP600125 decreased TNF-α level, which may have contributed to the inactivation of p65NF-κB and increase in GR expression, as confirmed by western blotting. In conclusion, ghrelin enhances wound recovery in CRBI rats, possibly by decreasing the induction of TNF-α or other proinflammatory mediators that are involved in the regulation of GHS-R1a-mediated MAPK-NF-κB/GR signaling pathways.
Collapse
|
20
|
Duan K, Yu W, Lin Z, Tan S, Bai X, Gao T, Xi F, Li N. Endotoxemia-induced muscle wasting is associated with the change of hypothalamic neuropeptides in rats. Neuropeptides 2014; 48:379-86. [PMID: 25459520 DOI: 10.1016/j.npep.2014.10.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 10/08/2014] [Accepted: 10/09/2014] [Indexed: 11/21/2022]
Abstract
In critical patients, sepsis-induced muscle wasting is considered to be an important contributor to complications and mortality. Previous work mainly focuses on the peripheral molecular mechanism of muscle degradation, however little evidence exists for the role of central nervous system in the process. In the present study, we, for the first time, characterized the relationship between muscle wasting and central neuropeptide changes in a septic model. Thirty-six adult male Sprague-Dawley rats were intraperitoneally injected with lipopolysaccharide (LPS) or saline. Twelve, 24 and 48 hrs after injection, skeletal muscle and hypothalamus tissues were harvested. Muscle wasting was measured by the mRNA expression of two E3 ubiquitin ligases, muscle ring finger 1 (MuRF-1) and muscle atrophy F-box (MAFbx), as well as 3-methyl-histidine (3-MH) and tyrosine release. Hypothalamic neuropeptides and inflammatory marker expressions were also measured in three time points. LPS injection caused an increase expression of MuRF-1 and MAFbx, and a significant higher release of 3-MH and tyrosine. Hypothalamic neuropeptides, proopiomelanocortin (POMC), cocaine- and amphetamine-regulated transcript (CART), agouti-related protein (AgRP) and neuropeptide Y (NPY) presented a dynamic change after LPS injection. Also, hypothalamic inflammatory markers, interleukin-1 β (IL-1β) and tumor necrosis factor α (TNF-α) increased substantially after LPS administration. Importantly, the expressions of POMC, AgRP and CART were well correlated with muscle atrophy gene, MuRF-1 expression. These findings suggest hypothalamic peptides and inflammation may participate in the sepsis-induced muscle wasting, but the exact mechanism needs further study.
Collapse
Affiliation(s)
- Kaipeng Duan
- Department of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002, China
| | - Wenkui Yu
- Department of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002, China.
| | - Zhiliang Lin
- Department of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002, China
| | - Shanjun Tan
- Department of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002, China
| | - Xiaowu Bai
- Department of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002, China
| | - Tao Gao
- Department of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002, China
| | - Fengchan Xi
- Department of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002, China
| | - Ning Li
- Department of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002, China.
| |
Collapse
|
21
|
Quintana HT, Bortolin JA, da Silva NT, Ribeiro FAP, Liberti EA, Ribeiro DA, de Oliveira F. Temporal study following burn injury in young rats is associated with skeletal muscle atrophy, inflammation and altered myogenic regulatory factors. Inflamm Res 2014; 64:53-62. [PMID: 25413930 DOI: 10.1007/s00011-014-0783-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 09/01/2014] [Accepted: 11/03/2014] [Indexed: 12/17/2022] Open
Abstract
INTRODUCTION Burn injury (BI) greater than 40% has been associated with protein catabolism and it is characterized by a hypermetabolic response followed for muscle loss. OBJECTIVE The purpose of this study was to investigate the temporal effects of extensive experimental BI in the skeletal muscle distant from lesion, through morphological analysis, expression of genes related to muscle atrophy, inflammation and the myogenic regulatory factors. MATERIALS AND METHODS A total of 60 young male wistar rats were distributed into two groups, control (C) and subjected to scald burn injury (SBI). The animals were euthanized 1, 4 and 14 days post-sham or 45% of the total body surface BI. The medial head of gastrocnemii muscles were submitted to histopathological, morphometric (muscle fibers area and density), MyoD and myogenin immunoexpression, and gene expression for TNF-α, iNOS and E3 ubiquitin ligases (MuRF1 and MAFbx). RESULTS Histopathological findings were consistent with increased amount of connective tissue and inflammatory process. Muscle fiber area of SBI groups was smaller than C and no differences were found in fiber muscle density. TNF-α was higher in SBI groups, one and 14 days post-injury; iNOS expression was higher on the first and fourth day post-injury. MuRF-1 was higher on the day four and MAFbx on the day 14. CONCLUSION In conclusion, BI causes inflammation, atrophy and myogenesis stimulation in muscle as a result of systemic host response.
Collapse
Affiliation(s)
- Hananiah Tardivo Quintana
- Department of Biosciences, Federal University of Sao Paulo, UNIFESP, Rua Silva Jardim, 136-Lab 328, Santos, SP, 11015-020, Brazil
| | | | | | | | | | | | | |
Collapse
|
22
|
Sheriff S, Kadeer N, Friend LA, James JH, Alexander JW, Balasubramaniam A. Des-acyl-ghrelin (DAG) normalizes hyperlactacidemia and improves survival in a lethal rat model of burn trauma. Peptides 2014; 60:1-7. [PMID: 25063053 DOI: 10.1016/j.peptides.2014.07.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 07/14/2014] [Accepted: 07/14/2014] [Indexed: 12/17/2022]
Abstract
Critical illness, including burn injury, results in elevated plasma lactate levels. Dysregulation of PI3K/Akt signaling has been shown to play a predominant role in the inactivation of skeletal muscle PDC and, hence, in hyperlactacidemia in rat models of sepsis and endotoxemia. This observation, and our previous finding that DAG can reverse burn-induced skeletal muscle proteolysis through the activation of PI3K/Akt pathway, led us to hypothesize that DAG may also attenuate hyperlactacidemia in burn injury. Our investigations revealed that burn injury significantly elevated both skeletal muscle lactate production and plasma lactate levels. Moreover, this was accompanied in skeletal muscle by a 5-7 fold increase in mRNA expression of pyruvate dehydrogenase kinases (PDK) 2 and 4, and a ∼30% reduction in PDC activity. DAG treatment of burn rats completely normalized not only the mRNA expression of the PDKs and PDC activity, but also hyperlactacidemia within 24h of burn injury. DAG also normalized epinephrine-induced lactate production by isolated skeletal muscles from normal rats. Moreover, DAG also improved survival in a lethal rat model of burn trauma. These findings with DAG may have clinical implications because chances of survival for critically ill patients are greatly improved if plasma lactate levels are normalized within 24h of injury.
Collapse
Affiliation(s)
- Sulaiman Sheriff
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Nijiati Kadeer
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Lou Ann Friend
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA
| | - J Howard James
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA
| | - J Wesley Alexander
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Ambikaipakan Balasubramaniam
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA; Cincinnati Veterans Affairs Medical Center, 3200 Vine Street, Cincinnati, OH 45220, USA.
| |
Collapse
|
23
|
Abstract
Muscle RING finger 1 (MuRF1) and muscle atrophy F-box (MAFbx)/atrogin-1 were identified more than 10 years ago as two muscle-specific E3 ubiquitin ligases that are increased transcriptionally in skeletal muscle under atrophy-inducing conditions, making them excellent markers of muscle atrophy. In the past 10 years much has been published about MuRF1 and MAFbx with respect to their mRNA expression patterns under atrophy-inducing conditions, their transcriptional regulation, and their putative substrates. However, much remains to be learned about the physiological role of both genes in the regulation of mass and other cellular functions in striated muscle. Although both MuRF1 and MAFbx are enriched in skeletal, cardiac, and smooth muscle, this review will focus on the current understanding of MuRF1 and MAFbx in skeletal muscle, highlighting the critical questions that remain to be answered.
Collapse
Affiliation(s)
- Sue C Bodine
- Departments of Neurobiology, Physiology, and Behavior and Physiology and Membrane Biology, University of California Davis, Davis, California; and Northern California Veterans Affairs Health Systems, Mather, California
| | - Leslie M Baehr
- Membrane Biology, University of California Davis, Davis, California; and
| |
Collapse
|
24
|
Joshi R, Kadeer N, Sheriff S, Friend LA, James JH, Balasubramaniam A. Phosphodiesterase (PDE) inhibitor torbafylline (HWA 448) attenuates burn-induced rat skeletal muscle proteolysis through the PDE4/cAMP/EPAC/PI3K/Akt pathway. Mol Cell Endocrinol 2014; 393:152-63. [PMID: 24973766 DOI: 10.1016/j.mce.2014.06.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 06/02/2014] [Accepted: 06/16/2014] [Indexed: 10/25/2022]
Abstract
Treatment of rats after burn-injury with the cyclic AMP phosphodiesterase (PDE) inhibitor, torbafylline (also known as HWA 448) significantly reversed changes in rat skeletal muscle proteolysis, PDE4 activity, cAMP concentrations and mRNA expression of TNFα, IL-6, ubiquitin and E3 ligases. Torbafylline also attenuated muscle proteolysis during in vitro incubation, and this effect was blocked by the inhibitor Rp-cAMPS. Moreover, torbafylline significantly increased phospho-Akt levels, and normalized downregulated phospho-FOXO1 and phospho-4E-BP1 in muscle of burn rats. Similarly, torbafylline also normalized phosphorylation levels of Akt and its downstream elements in TNFα+IFNγ treated C2C12 myotubes. Torbafylline enhanced protein levels of exchange protein directly activated by cAMP (Epac) both in skeletal muscle of burn rats and in TNFα+IFNγ treated C2C12 myotubes. Pretreatment with a specific antagonist of PI3K or Epac significantly reversed the inhibitory effects of torbafylline on TNFα+IFNγ-induced MAFbx mRNA expression and protein breakdown in C2C12 myotubes. Torbafylline inhibits burn-induced muscle proteolysis by activating multiple pathways through PDE4/cAMP/Epac/PI3K/Akt.
Collapse
Affiliation(s)
- Rashika Joshi
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Nijiati Kadeer
- Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Sulaiman Sheriff
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA
| | - Lou Ann Friend
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA
| | - J Howard James
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Ambikaipakan Balasubramaniam
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA; Cincinnati Veterans Affairs Medical Center, 3200 Vine Street, Cincinnati, OH 45220, USA.
| |
Collapse
|
25
|
Yu AP, Pei XM, Sin TK, Yip SP, Yung BY, Chan LW, Wong CS, Siu PM. Acylated and unacylated ghrelin inhibit doxorubicin-induced apoptosis in skeletal muscle. Acta Physiol (Oxf) 2014; 211:201-13. [PMID: 24581239 DOI: 10.1111/apha.12263] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 01/28/2014] [Accepted: 02/24/2014] [Indexed: 12/28/2022]
Abstract
AIM Doxorubicin, a potent chemotherapeutic drug, has been demonstrated previously as an inducer of apoptosis in muscle cells. Extensive induction of apoptosis may cause excessive loss of muscle cells and subsequent functional decline in skeletal muscle. This study examined the effects of acylated ghrelin, a potential agent for treating cancer cachexia, on inhibiting apoptotic signalling in doxorubicin-treated skeletal muscle. Unacylated ghrelin, a form of ghrelin that does not bind to GHSR-1a, is also employed in this study to examine the GHSR-1a signalling dependency of the effects of ghrelin. METHODS Adult C57BL/6 mice were randomly assigned to saline control (CON), doxorubicin (DOX), doxorubicin with treatment of acylated ghrelin (DOX+Acylated Ghrelin) and doxorubicin with treatment of unacylated ghrelin (DOX+Unacylated Ghrelin). Mice in all groups that involved DOX were intraperitoneally injected with 15 mg of doxorubicin per kg body weight, whereas mice in CON group received saline as placebo. Gastrocnemius muscle tissues were harvested after the experimental period for analysis. RESULTS The elevation of apoptotic DNA fragmentation and number of TUNEL-positive nuclei were accompanied with the upregulation of Bax in muscle after exposure to doxorubicin, but all these changes were neither seen in the muscle treated with acylated ghrelin nor unacylated ghrelin after doxorubicin exposure. Protein abundances of autophagic markers including LC3 II-to-LC3 I ratio, Atg12-5 complex, Atg5 and Beclin-1 were not altered by doxorubicin but were upregulated by the treatment of either acylated or unacyated ghrelin. Histological analysis revealed that the amount of centronucleated myofibres was elevated in doxorubicin-treated muscle while muscle of others groups showed normal histology. CONCLUSIONS Collectively, our data demonstrated that acylated ghrelin administration suppresses the doxorubicin-induced activation of apoptosis and enhances the cellular signalling of autophagy. The treatment of unacylated ghrelin has similar effects as acylated ghrelin on apoptotic and autophagic signalling, suggesting that the effects of ghrelin are probably mediated through a signalling pathway that is independent of GHSR-1a. These findings were consistent with the hypothesis that acylated ghrelin inhibits doxorubicin-induced upregulation of apoptosis in skeletal muscle while treatment of unacylated ghrelin can achieve similar effects as the treatment of acylated ghrelin. The inhibition of apoptosis and enhancement of autophagy induced by acylated and unacylated ghrelin might exert myoprotective effects on doxorubicin-induced toxicity in skeletal muscle.
Collapse
Affiliation(s)
- A. P. Yu
- Department of Health Technology and Informatics; The Hong Kong Polytechnic University; Hong Kong China
| | - X. M. Pei
- Department of Health Technology and Informatics; The Hong Kong Polytechnic University; Hong Kong China
| | - T. K. Sin
- Department of Health Technology and Informatics; The Hong Kong Polytechnic University; Hong Kong China
| | - S. P. Yip
- Department of Health Technology and Informatics; The Hong Kong Polytechnic University; Hong Kong China
| | - B. Y. Yung
- Department of Health Technology and Informatics; The Hong Kong Polytechnic University; Hong Kong China
| | - L. W. Chan
- Department of Health Technology and Informatics; The Hong Kong Polytechnic University; Hong Kong China
| | - C. S. Wong
- Department of Health Technology and Informatics; The Hong Kong Polytechnic University; Hong Kong China
| | - P. M. Siu
- Department of Health Technology and Informatics; The Hong Kong Polytechnic University; Hong Kong China
| |
Collapse
|
26
|
Bonfili L, Cuccioloni M, Cecarini V, Mozzicafreddo M, Palermo FA, Cocci P, Angeletti M, Eleuteri AM. Ghrelin induces apoptosis in colon adenocarcinoma cells via proteasome inhibition and autophagy induction. Apoptosis 2014; 18:1188-200. [PMID: 23632965 DOI: 10.1007/s10495-013-0856-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Ghrelin is a metabolism-regulating hormone recently investigated for its role in cancer survival and progression. Controversially, ghrelin may act as either anti-apoptotic or pro-apoptotic factor in different cancer cells, suggesting that the effects are cell type dependent. Limited data are currently available on the effects exerted by ghrelin on intracellular proteolytic pathways in cancer. Both the lysosomal and the proteasomal systems are fundamental in cellular proliferation and apoptosis regulation. With the aim of exploring if the proteasome and autophagy may be possible targets of ghrelin in cancer, we exposed human colorectal adenocarcinoma cells to ghrelin. Preliminary in vitro fluorimetric assays evidenced for the first time a direct inhibition of 20S proteasomes by ghrelin, particularly evident for the trypsin-like activity. Moreover, 1 μM ghrelin induced apoptosis in colorectal adenocarcinoma cells by inhibiting the ubiquitin-proteasome system and by activating autophagy, with p53 having an "interactive" role.
Collapse
Affiliation(s)
- Laura Bonfili
- School of Biosciences and Biotechnology, University of Camerino, Via Gentile III da Varano, 62032, Camerino, Macerata, Italy,
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Wade CE, Baer LA, Wu X, Silliman DT, Walters TJ, Wolf SE. Severe burn and disuse in the rat independently adversely impact body composition and adipokines. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2013; 17:R225. [PMID: 24099533 PMCID: PMC4057079 DOI: 10.1186/cc13048] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 08/28/2013] [Indexed: 12/26/2022]
Abstract
Introduction Severe trauma is accompanied by a period of hypermetabolism and disuse. In this study, a rat model was used to determine the effects of burn and disuse independently and in combination on body composition, food intake and adipokines. Methods Male rats were assigned to four groups 1) sham ambulatory (SA), 2) sham hindlimb unloaded (SH), 3) 40% total body surface area full thickness scald burn ambulatory (BA) and 4) burn and hindlimb unloaded (BH). Animals designated to the SH and BH groups were placed in a tail traction system and their hindlimbs unloaded. Animals were followed for 14 days. Plasma, urine, fecal and tissue samples were analyzed. Results SA had a progressive increase in body mass (BM), SH and BA no change and BH a reduction. Compared to SA, BM was reduced by 10% in both SH and BA and by 17% when combined in BH. Compared to SA, all groups had reductions in lean and fat body mass with BH being greater. The decrease in lean mass was associated with the rate of urinary corticosterone excretion. The loss in fat mass was associated with decreases in plasma leptin and adiponectin and an increase in ghrelin. Following the acute response to injury, BH had a greater food intake per 100 g BM. Food intake was associated with the levels of leptin, adiponectin and ghrelin. Conclusions The effects of the combination of burn and disuse in this animal model were additive, therefore in assessing metabolic changes with severe trauma both injury and disuse should be considered. Furthermore, the observed changes in adipokines, corticosterone and ghrelin provide insights for interventions to attenuate the hypermetabolic state following injury, possibly reducing catabolism and muscle loss and subsequent adverse effects on recovery and function.
Collapse
|
28
|
Amitani M, Asakawa A, Amitani H, Inui A. Control of food intake and muscle wasting in cachexia. Int J Biochem Cell Biol 2013; 45:2179-85. [DOI: 10.1016/j.biocel.2013.07.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 07/16/2013] [Accepted: 07/16/2013] [Indexed: 12/14/2022]
|
29
|
Liantonio A, Gramegna G, Carbonara G, Sblendorio VT, Pierno S, Fraysse B, Giannuzzi V, Rizzi L, Torsello A, Camerino DC. Growth hormone secretagogues exert differential effects on skeletal muscle calcium homeostasis in male rats depending on the peptidyl/nonpeptidyl structure. Endocrinology 2013; 154:3764-75. [PMID: 23836033 DOI: 10.1210/en.2013-1334] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The orexigenic and anabolic effects induced by ghrelin and the synthetic GH secretagogues (GHSs) are thought to positively contribute to therapeutic approaches and the adjunct treatment of a number of diseases associated with muscle wasting such as cachexia and sarcopenia. However, many questions about the potential utility and safety of GHSs in both therapy and skeletal muscle function remain unanswered. By using fura-2 cytofluorimetric technique, we determined the acute effects of ghrelin, as well as of peptidyl and nonpeptidyl synthetic GHSs on calcium homeostasis, a critical biomarker of muscle function, in isolated tendon-to-tendon male rat skeletal muscle fibers. The synthetic nonpeptidyl GHSs, but not peptidyl ghrelin and hexarelin, were able to significantly increase resting cytosolic calcium [Ca²⁺]i. The nonpeptidyl GHS-induced [Ca²⁺]i increase was independent of GHS-receptor 1a but was antagonized by both thapsigargin/caffeine and cyclosporine A, indicating the involvement of the sarcoplasmic reticulum and mitochondria. Evaluation of the effects of a pseudopeptidyl GHS and a nonpeptidyl antagonist of the GHS-receptor 1a together with a drug-modeling study suggest the conclusion that the lipophilic nonpeptidyl structure of the tested compounds is the key chemical feature crucial for the GHS-induced calcium alterations in the skeletal muscle. Thus, synthetic GHSs can have different effects on skeletal muscle fibers depending on their molecular structures. The calcium homeostasis dysregulation specifically induced by the nonpeptidyl GHSs used in this study could potentially counteract the beneficial effects associated with these drugs in the treatment of muscle wasting of cachexia- or other age-related disorders.
Collapse
MESH Headings
- Animals
- Appetite Stimulants/adverse effects
- Appetite Stimulants/pharmacology
- Calcium Signaling/drug effects
- Cell Line
- Cell Membrane Permeability/drug effects
- Cell Survival/drug effects
- Cytosol/drug effects
- Cytosol/metabolism
- Ghrelin/analogs & derivatives
- Ghrelin/metabolism
- Growth Hormone/metabolism
- Male
- Mitochondria, Muscle/drug effects
- Mitochondria, Muscle/metabolism
- Muscle Fibers, Skeletal/drug effects
- Muscle Fibers, Skeletal/metabolism
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Oligopeptides/adverse effects
- Oligopeptides/pharmacology
- Piperidines/adverse effects
- Piperidines/pharmacology
- Pituitary Gland, Anterior/drug effects
- Pituitary Gland, Anterior/metabolism
- Rats
- Rats, Wistar
- Receptors, Ghrelin/agonists
- Receptors, Ghrelin/antagonists & inhibitors
- Receptors, Ghrelin/metabolism
- Sarcolemma/drug effects
- Sarcolemma/metabolism
- Sarcoplasmic Reticulum/drug effects
- Sarcoplasmic Reticulum/metabolism
- Spiro Compounds/adverse effects
- Spiro Compounds/pharmacology
- Structure-Activity Relationship
Collapse
Affiliation(s)
- Antonella Liantonio
- Section of Pharmacology, Department of Pharmacy-Drug Sciences, University of Bari, Via Orabona, 4, Campus, I-70125 Bari, Italy.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Temporal development of muscle atrophy in murine model of arthritis is related to disease severity. J Cachexia Sarcopenia Muscle 2013; 4:231-8. [PMID: 23389765 PMCID: PMC3774915 DOI: 10.1007/s13539-013-0102-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 01/13/2013] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Rheumatoid arthritis (RA) is an inflammatory autoimmune disease of unknown etiology, affecting mainly the joint but also other tissues. RA patients usually present weakness and muscle atrophy, nonarticular manifestations of the disease. Although causing great impact, the understanding of muscle atrophy, its development, and the mechanisms involved is still very limited. The objective of this study is to evaluate the development of muscle atrophy in skeletal muscle of a murine model of arthritis. METHODS The experimental murine model of collagen-induced arthritis (CIA) was used. DBA/1J mice were randomly divided into three groups: control (CO, n = 25), sham arthritis (SA, n = 25), and arthritis (CIA, n = 28), analyzed in different time points: 25, 35, and 45 days after the induction of arthritis. The arthritis development was followed by clinical scores and hind paw edema three times a week. The spontaneous exploratory locomotion and weight were evaluated weekly. In all time points, serum was collected before the death of the animals for cytokine analysis, and myofiber cross-sectional areas (CSA) of gastrocnemius (GA) and tibialis anterior (TA) skeletal muscles were evaluated. RESULTS The clinical parameters of arthritis progressively increased in CIA in all experimental times, demonstrating the greatest difference from other groups at 45 days after induction (clinical score: CO, 00 ± 00; SA, 1.00 ± 0.14; CIA, 3.28 ± 0.41 p > 0.05). The CIA animals had lower weights during all the experimentation periods with a difference of 6 % from CO at 45 days (p > 0.05). CIA animals also demonstrated progressive decrease in distance walked, with a reduction of 54 % in 35 and 74 % at 45 days. Cytokine analysis identified significant increase in IL-6 serum levels in CIA than CO and SA in all experimental times. CSA of the myofiber of GA and TA was decreased 26 and 31 % (p > 0.05) in CIA in 45 days after the induction of disease, respectively. There was significant and inverse correlation between the disease clinical score and myofiber CSA in 45 days (GA: r = -0.71; p = 0.021). CONCLUSION Our results point to a progressive development of muscle wasting, with premature onset arthritis. These observations are relevant to understand the development of muscle loss, as well as for the design of future studies trying to understand the mechanisms involved in muscle wasting. As far as we are concerned, this is the first study to evaluate the relation between disease score and muscle atrophy in a model of arthritis.
Collapse
|
31
|
Suzuki H, Asakawa A, Amitani H, Nakamura N, Inui A. Cancer cachexia--pathophysiology and management. J Gastroenterol 2013; 48:574-94. [PMID: 23512346 PMCID: PMC3698426 DOI: 10.1007/s00535-013-0787-0] [Citation(s) in RCA: 176] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 02/20/2013] [Indexed: 02/04/2023]
Abstract
About half of all cancer patients show a syndrome of cachexia, characterized by anorexia and loss of adipose tissue and skeletal muscle mass. Cachexia can have a profound impact on quality of life, symptom burden, and a patient's sense of dignity. It is a very serious complication, as weight loss during cancer treatment is associated with more chemotherapy-related side effects, fewer completed cycles of chemotherapy, and decreased survival rates. Numerous cytokines have been postulated to play a role in the etiology of cancer cachexia. Cytokines can elicit effects that mimic leptin signaling and suppress orexigenic ghrelin and neuropeptide Y (NPY) signaling, inducing sustained anorexia and cachexia not accompanied by the usual compensatory response. Furthermore, cytokines have been implicated in the induction of cancer-related muscle wasting. Cytokine-induced skeletal muscle wasting is probably a multifactorial process, which involves a protein synthesis inhibition, an increase in protein degradation, or a combination of both. The best treatment of the cachectic syndrome is a multifactorial approach. Many drugs including appetite stimulants, thalidomide, cytokine inhibitors, steroids, nonsteroidal anti-inflammatory drugs, branched-chain amino acids, eicosapentaenoic acid, and antiserotoninergic drugs have been proposed and used in clinical trials, while others are still under investigation using experimental animals. There is a growing awareness of the positive impact of supportive care measures and development of promising novel pharmaceutical agents for cachexia. While there has been great progress in understanding the underlying biological mechanisms of cachexia, health care providers must also recognize the psychosocial and biomedical impact cachexia can have.
Collapse
Affiliation(s)
- Hajime Suzuki
- />Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima, 890-8520 Japan
- />Department of Oral and Maxillofacial Surgery, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, 890-8520 Japan
| | - Akihiro Asakawa
- />Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima, 890-8520 Japan
| | - Haruka Amitani
- />Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima, 890-8520 Japan
| | - Norifumi Nakamura
- />Department of Oral and Maxillofacial Surgery, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, 890-8520 Japan
| | - Akio Inui
- />Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima, 890-8520 Japan
| |
Collapse
|
32
|
Porporato PE, Filigheddu N, Reano S, Ferrara M, Angelino E, Gnocchi VF, Prodam F, Ronchi G, Fagoonee S, Fornaro M, Chianale F, Baldanzi G, Surico N, Sinigaglia F, Perroteau I, Smith RG, Sun Y, Geuna S, Graziani A. Acylated and unacylated ghrelin impair skeletal muscle atrophy in mice. J Clin Invest 2013; 123:611-22. [PMID: 23281394 DOI: 10.1172/jci39920] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 11/01/2012] [Indexed: 01/30/2023] Open
Abstract
Cachexia is a wasting syndrome associated with cancer, AIDS, multiple sclerosis, and several other disease states. It is characterized by weight loss, fatigue, loss of appetite, and skeletal muscle atrophy and is associated with poor patient prognosis, making it an important treatment target. Ghrelin is a peptide hormone that stimulates growth hormone (GH) release and positive energy balance through binding to the receptor GHSR-1a. Only acylated ghrelin (AG), but not the unacylated form (UnAG), can bind GHSR-1a; however, UnAG and AG share several GHSR-1a-independent biological activities. Here we investigated whether UnAG and AG could protect against skeletal muscle atrophy in a GHSR-1a-independent manner. We found that both AG and UnAG inhibited dexamethasone-induced skeletal muscle atrophy and atrogene expression through PI3Kβ-, mTORC2-, and p38-mediated pathways in myotubes. Upregulation of circulating UnAG in mice impaired skeletal muscle atrophy induced by either fasting or denervation without stimulating muscle hypertrophy and GHSR-1a-mediated activation of the GH/IGF-1 axis. In Ghsr-deficient mice, both AG and UnAG induced phosphorylation of Akt in skeletal muscle and impaired fasting-induced atrophy. These results demonstrate that AG and UnAG act on a common, unidentified receptor to block skeletal muscle atrophy in a GH-independent manner.
Collapse
Affiliation(s)
- Paolo E Porporato
- Department of Translational Medicine, Interdisciplinary Research Center of Autoimmune Diseases (IRCAD), and Biotechnology Center for Applied Medical Research (BRMA), Università del Piemonte Orientale "Amedeo Avogadro" — Alessandria, Novara, Vercelli, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Raimondo S, Ronchi G, Geuna S, Pascal D, Reano S, Filigheddu N, Graziani A. Ghrelin: a novel neuromuscular recovery promoting factor? INTERNATIONAL REVIEW OF NEUROBIOLOGY 2013; 108:207-21. [PMID: 24083436 DOI: 10.1016/b978-0-12-410499-0.00008-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Promoting neuromuscular recovery after neural injury is a major clinical issue. While techniques for nerve reconstruction are continuously improving and most peripheral nerve lesions can be repaired today, recovery of the lost function is usually unsatisfactory. This evidence claims for innovative nonsurgical therapeutic strategies that can implement the outcome after neural repair. Although no pharmacological approach for improving posttraumatic neuromuscular recovery has still entered clinical practice, various molecules are explored in experimental models of neural repair. One of such molecules is the circulating peptide hormone ghrelin. This hormone has proved to have a positive effect on neural repair after central nervous system lesion, and very recently its effectiveness has also been demonstrated in preventing posttraumatic skeletal muscle atrophy. By contrast, no information is still available about its effectiveness on peripheral nerve regeneration although preliminary data from our laboratory suggest that this molecule can have an effect also in promoting axonal regeneration after nerve injury and repair. Should this be confirmed, ghrelin might represent an ideal candidate as a therapeutic agent for improving posttraumatic neuromuscular recovery because of its putative effects at all the various structural levels involved in this regeneration process, namely, the central nervous system, the peripheral nerve, and the target skeletal muscle.
Collapse
Affiliation(s)
- Stefania Raimondo
- Department of Clinical and Biological Sciences, University of Turin & Neuroscience Institute Cavalieri Ottolenghi, Turin, Italy
| | | | | | | | | | | | | |
Collapse
|
34
|
Steinman J, DeBoer MD. Treatment of cachexia: melanocortin and ghrelin interventions. VITAMINS AND HORMONES 2013; 92:197-242. [PMID: 23601426 DOI: 10.1016/b978-0-12-410473-0.00008-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cachexia is a condition typified by wasting of fat and LBM caused by anorexia and further endocrinological modulation of energy stores. Diseases known to cause cachectic symptoms include cancer, chronic kidney disease, and chronic heart failure; these conditions are associated with increased levels of proinflammatory cytokines and increased resting energy expenditure. Early studies have suggested the central melanocortin system as one of the main mediators of the symptoms of cachexia. Pharmacological and genetic antagonism of these pathways attenuates cachectic symptoms in laboratory models; effects have yet to be studied in humans. In addition, ghrelin, an endogenous orexigenic hormone with receptors on melanocortinergic neurons, has been shown to ameliorate symptoms of cachexia, at least in part, by an increase in appetite via melanocortin modulation, in addition to its anticatabolic and anti-inflammatory effects. These effects of ghrelin have been confirmed in multiple types of cachexia in both laboratory and human studies, suggesting a positive future for cachexia treatments.
Collapse
Affiliation(s)
- Jeremy Steinman
- Division of Pediatric Endocrinology, Department of Pediatrics, P.O. Box 800386, University of Virginia, Charlottesville, Virginia, USA
| | | |
Collapse
|
35
|
Guillory B, Splenser A, Garcia J. The Role of Ghrelin in Anorexia–Cachexia Syndromes. ANOREXIA 2013; 92:61-106. [DOI: 10.1016/b978-0-12-410473-0.00003-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
36
|
Ghrelin improves body weight loss and skeletal muscle catabolism associated with angiotensin II-induced cachexia in mice. ACTA ACUST UNITED AC 2012; 178:21-8. [PMID: 22750276 DOI: 10.1016/j.regpep.2012.06.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 05/25/2012] [Accepted: 06/20/2012] [Indexed: 12/20/2022]
Abstract
Ghrelin is a gastric peptide that regulates energy homeostasis. Angiotensin II (Ang II) is known to induce body weight loss and skeletal muscle catabolism through the ubiquitin-proteasome pathway. In this study, we investigated the effects of ghrelin on body weight and muscle catabolism in mice treated with Ang II. The continuous subcutaneous administration of Ang II to mice for 6 days resulted in cardiac hypertrophy and significant decreases in body weight gain, food intake, food efficiency, lean mass, and fat mass. In the gastrocnemius muscles of Ang II-treated mice, the levels of insulin-like growth factor 1 (IGF-1) were decreased, and the levels of mRNA expression of catabolic factors were increased. Although the repeated subcutaneous injections of ghrelin (1.0mg/kg, twice daily for 5 days) did not affect cardiac hypertrophy, they resulted in significant body weight gains and improved food efficiencies and tended to increase both lean and fat mass in Ang II-treated mice. Ghrelin also ameliorated the decreased IGF-1 levels and the increased mRNA expression levels of catabolic factors in the skeletal muscle. IGF-1 mRNA levels in the skeletal muscle significantly decreased 24h after Ang II infusion, and this was reversed by two subcutaneous injections of ghrelin. In C2C12-derived myocytes, the dexamethasone-induced mRNA expression of atrogin-1 was decreased by IGF-1 but not by ghrelin. In conclusion, we demonstrated that ghrelin improved body weight loss and skeletal muscle catabolism in mice treated with Ang II, possibly through the early restoration of IGF-1 mRNA in the skeletal muscle and the amelioration of nutritional status.
Collapse
|
37
|
Abstract
PURPOSE OF REVIEW Recovery and rehabilitation after critical illness is a vital part of intensive care management. The role of feeding and nutritional intervention is the subject of many recent studies. The gastric hormone ghrelin has effects on appetite and food intake and on immunomodulatory functions. Here we review the interactions between critical illness, appetite regulation, nutrition and ghrelin. RECENT FINDINGS Critical illness results in significant loss of lean body mass; strategies to prevent this have so far proven unsuccessful. Ghrelin has been shown to reduce catabolic protein loss in animal models of critical illness and improve body composition in chronic cachectic illnesses in humans. SUMMARY Enhancing recovery from critical illness will improve both short-term and long-term outcomes. Ghrelin may offer an important means of improving appetite, muscle mass and rehabilitation in the period after critical illness, although studies are needed to see whether this potential is realized.
Collapse
|
38
|
Sheriff S, Kadeer N, Joshi R, Friend LA, James JH, Balasubramaniam A. Des-acyl ghrelin exhibits pro-anabolic and anti-catabolic effects on C2C12 myotubes exposed to cytokines and reduces burn-induced muscle proteolysis in rats. Mol Cell Endocrinol 2012; 351:286-95. [PMID: 22266196 DOI: 10.1016/j.mce.2011.12.021] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 12/16/2011] [Accepted: 12/30/2011] [Indexed: 01/22/2023]
Abstract
Although ghrelin and GHRP-2 have been shown to inhibit skeletal muscle proteolysis in rats with burn injury, the effects of des-acyl ghrelin (DAG) have not been reported. In this paper, we demonstrate that continuous 24h administration of DAG attenuated burn-induced EDL muscle proteolysis, and normalized elevated TNFα mRNA. Combined treatment of cultured C2C12 myotubes with TNFα and IFN-γ (TNF+IFN) inhibited protein synthesis and increased protein breakdown; DAG abolished both effects. PI3 kinase inhibition by LY294002 and mTOR inhibition by rapamycin blocked the reversal of the anti-anabolic effects of TNF+IFN-treated myotubes by DAG. DAG also reversed or attenuated the TNF+IFN-induced reduction in phosphorylation of Akt, FOXO1, 4E-BP-1, and GSK-3β in myotubes. Furthermore, DAG attenuated the atrophy signal, phospho-NF-κB, and the mRNA expression of MAFbx and MuRF1, upregulated by TNF+IFN in C2C12 myotubes. We conclude that DAG reduces muscle cachexia produced by injury and proinflammatory cytokines, and that DAG or DAG-based compounds may be useful in treating wasting disorders.
Collapse
Affiliation(s)
- Sulaiman Sheriff
- Department of Surgery, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | | | | | | | | | | |
Collapse
|
39
|
Akamizu T, Kangawa K. The physiological significance and potential clinical applications of ghrelin. Eur J Intern Med 2012; 23:197-202. [PMID: 22385874 DOI: 10.1016/j.ejim.2011.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 11/30/2011] [Accepted: 12/06/2011] [Indexed: 12/24/2022]
Abstract
Ghrelin, a natural ligand for the growth hormone (GH)-secretagogue receptor (GHS-R), is now known to play a role in a number of different physiological processes. For example, ghrelin increases GH secretion, feeding, and body weight when administered centrally or peripherally. These unique effects of ghrelin should be invaluable for the development of novel treatments and disease diagnostic techniques. Clinical trials have already been performed to assess the utility of ghrelin for the treatment of several disorders including anorexia, cachexia, and GH-related disorders. This review summarizes the recent advances in this area of research.
Collapse
Affiliation(s)
- Takashi Akamizu
- Ghrelin Research Project, Department of Experimental Therapeutics, Translational Research Center, Kyoto University Hospital, Kyoto University School of Medicine, Kyoto 606-8507, Japan.
| | | |
Collapse
|
40
|
Merritt EK, Cross JM, Bamman MM. Inflammatory and protein metabolism signaling responses in human skeletal muscle after burn injury. J Burn Care Res 2012; 33:291-7. [PMID: 22079905 PMCID: PMC3292697 DOI: 10.1097/bcr.0b013e3182331e4b] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Severe burn injuries lead to a prolonged hypercatabolic state resulting in dramatic loss of skeletal muscle mass. Postburn muscle loss is well documented but the molecular signaling cascade preceding atrophy is not. The purpose of this study is to determine the response to burn injury of signaling pathways driving muscle inflammation and protein metabolism. Muscle biopsies were collected in the early flow phase after burn injury from the vastus lateralis of a noninjured leg in patients with 20 to 60% TBSA burns and compared with uninjured, matched controls. Circulating levels of proinflammatory cytokines were also compared. Immunoblotting was performed to determine the protein levels of key signaling components for translation initiation, proteolysis, and tumor necrosis factor/nuclear factor kappa B (NFκB)and interleukin (IL)-6/STAT3 signaling. Burn subjects had significantly higher levels of circulating proinflammatory cytokines, with no difference in muscle STAT3 activity and lower NFκB activity. No differences were found in any translational signaling components. Regarding proteolytic signaling in burn, calpain-2 was 47% higher, calpastatin tended to be lower, and total ubiquitination was substantially higher. Surprisingly, a systemic proinflammatory response 3 to 10 days postburn did not lead to elevated muscle STAT3 or NFκB signaling. Signaling molecules governing translation initiation were unaffected, whereas indices of calcium-mediated proteolysis and ubiquitin-proteasome activity were upregulated. These novel findings are the first in humans to suggest that the net catabolic effect of burn injury in skeletal muscle (ie, atrophy) may be mediated, at least during the early flow phase, almost entirely by an increased proteolytic activity in the absence of suppressed protein synthesis signaling.
Collapse
Affiliation(s)
- Edward K Merritt
- Department of Physiology and Biophysics, University of Alabama at Birmingham, Alabama 35294-0005, USA
| | | | | |
Collapse
|
41
|
Akamizu T, Kangawa K. Therapeutic applications of ghrelin to cachexia utilizing its appetite-stimulating effect. Peptides 2011; 32:2295-300. [PMID: 21635929 DOI: 10.1016/j.peptides.2011.05.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 05/13/2011] [Accepted: 05/16/2011] [Indexed: 02/07/2023]
Abstract
Ghrelin, which is a natural ligand for the growth hormone (GH)-secretagogue receptor (GHS-R), stimulates food intake in both animals and humans. Ghrelin is the only circulating hormone known to stimulate appetite in humans. Ghrelin also stimulates GH secretion and inhibits the production of anorectic proinflammatory cytokines. As GH is an anabolic hormone, protein stores are spared at the expense of fat during conditions of caloric restriction. Thus, ghrelin exhibits anti-cachectic actions via both GH-dependent and -independent mechanisms. Several studies are evaluating the efficacy of ghrelin in the treatment of cachexia caused by a variety of diseases, including congestive heart failure, chronic obstructive pulmonary disease, cancer, and end-stage renal disease. These studies will hopefully lead to the development of novel therapeutic applications for ghrelin in the future. This review summarizes the recent advances in this area of research.
Collapse
Affiliation(s)
- Takashi Akamizu
- The First Department of Medicine, Wakayama Medical University, Wakayama 641-8509, Japan.
| | | |
Collapse
|
42
|
Watanabe M, Sheriff S, Ramelot TA, Kadeer N, Cho J, Lewis KB, Balasubramaniam A, Kennedy MA. NMR Based Metabonomics Study of DAG Treatment in a C2C12 Mouse Skeletal Muscle Cell Line Myotube Model of Burn-Injury. Int J Pept Res Ther 2011. [DOI: 10.1007/s10989-011-9264-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
43
|
Koshinaka K, Toshinai K, Mohammad A, Noma K, Oshikawa M, Ueno H, Yamaguchi H, Nakazato M. Therapeutic potential of ghrelin treatment for unloading-induced muscle atrophy in mice. Biochem Biophys Res Commun 2011; 412:296-301. [DOI: 10.1016/j.bbrc.2011.07.086] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 07/20/2011] [Indexed: 01/06/2023]
|
44
|
Baatar D, Patel K, Taub DD. The effects of ghrelin on inflammation and the immune system. Mol Cell Endocrinol 2011; 340:44-58. [PMID: 21565248 DOI: 10.1016/j.mce.2011.04.019] [Citation(s) in RCA: 185] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 04/15/2011] [Accepted: 04/22/2011] [Indexed: 12/25/2022]
Abstract
A number of hormones and metabolic mediators signal the brain of changes in the body's energy status and when an imbalance occurs; the brain coordinates the appropriate changes in energy intake and utilization via the control of appetite and food consumption. Under conditions of chronic inflammation and immune activation, there is often a significant loss of body mass and appetite suggesting the presence of shared ligands and signaling pathways mediating "crosstalk" between the immune and neuroendocrine systems. Ghrelin, the endogenous ligand for growth hormone secretagogue receptor (GHS-R), is produced primarily by cells in the stomach and serves as a potent circulating orexigenic hormone controlling food intake, energy expenditure, adiposity and GH secretion. The functional roles of ghrelin and other growth hormone secretagogues (GHS) within the immune system and under states of inflammatory stress and injury are only now coming to light. A number of reports over the past decade have described ghrelin to be a potent anti-inflammatory mediator both in vitro and in vivo and a promising therapeutic agent in the treatment of inflammatory diseases and injury. Moreover, ghrelin has also been shown to promote lymphocyte development in the primary lymphoid organs (bone marrow and thymus) and to ablate age-associated thymic involution. In the current report, we review the literature supporting a role for ghrelin as an anti-inflammatory agent and immunoregulatory hormone/cytokine and its potential use in the treatment of inflammatory diseases and injury.
Collapse
Affiliation(s)
- Dolgor Baatar
- Laboratory of Molecular Biology and Immunology, NIA-IRP, NIH, Biomedical Research Center, Baltimore, MD 21224, USA
| | | | | |
Collapse
|
45
|
Abstract
Research in burn care for the calendar year 2009 was robust and diverse with >1400 research articles published on a wide range of topics. In this review, the authors highlight some innovative and potentially impactful research related to the overall care of burn- injured patients. The authors grouped articles according to the following categories: critical care, infection, inhalation injury, epidemiology, psychology, wound characterization and treatment, nutrition and metabolism, pain and itch management, burn reconstruction, and rehabilitation. They found that the holistic nature of burn care is reflected in the diverse research performed in 2009 throughout the world and that this research has provided important evidence that has improved or will improve burn care overall.
Collapse
|
46
|
Abstract
Ghrelin, a natural ligand for the growth hormone (GH)-secretagogue receptor, is primarily produced in the stomach. Administration of ghrelin stimulates food intake and GH secretion in both animals and humans. Ghrelin is the only circulating hormone known to stimulate appetite in humans. As GH is an anabolic hormone, protein stores are spared at the expense of fat during conditions of caloric restriction. Ghrelin also inhibits the production of anorectic proinflammatory cytokines. Thus, ghrelin exhibits anti-cachectic actions via both GH-dependent and -independent mechanisms. Several studies are evaluating the efficacy of ghrelin in the treatment of cachexia caused by a variety of diseases, including congestive heart failure, chronic obstructive pulmonary disease, cancer, and end-stage renal disease. These studies will hopefully lead to the development of novel clinical applications for ghrelin in the future. These studies have also facilitated a better understanding of the molecular basis of the anti-catabolic effects of ghrelin. This review summarizes the recent advances in this area of research.
Collapse
|
47
|
Current World Literature. Curr Opin Support Palliat Care 2009; 3:305-12. [DOI: 10.1097/spc.0b013e3283339c93] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
48
|
Sheriff S, Joshi R, Friend LA, James JH, Balasubramaniam A. Ghrelin receptor agonist, GHRP-2, attenuates burn injury-induced MuRF-1 and MAFbx expression and muscle proteolysis in rats. Peptides 2009; 30:1909-13. [PMID: 19577604 DOI: 10.1016/j.peptides.2009.06.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Revised: 06/24/2009] [Accepted: 06/24/2009] [Indexed: 10/20/2022]
Abstract
Thermal injury results in hypermetabolism, loss of body weight, and skeletal muscle wasting in mice and rats. Our earlier studies have demonstrated that ghrelin injection stimulates food intake and growth hormone release and inhibits skeletal muscle proteolysis in rats with thermal injury. We sought to develop a lower molecular weight, stable and longer acting peptide to combat the catabolic responses caused by thermal injury. Towards this goal, we examined the role of the hexapeptide mimetic of ghrelin, growth hormone-releasing peptide-2 (GHRP-2), on expression of E3 ubiquitin ligases and breakdown of muscle protein in rats with thermal injury. Slow in vivo release of GHRP-2 through minipump for 24h attenuated the thermal injury-induced increase in mRNA expression of IL-6 and of the E3 ubiquitin ligases, MuRF-1 and MAFbx, in rat skeletal muscle. Furthermore, burn-induced increases in total and myofibrillar protein breakdown from rat EDL muscle were attenuated by GHRP-2. These findings suggest that catabolic responses resulting from thermal injury can be attenuated by GHRP-2.
Collapse
Affiliation(s)
- Sulaiman Sheriff
- Department of Surgery, University of Cincinnati College of Medicine, and Shriners Hospital for Children, 231 Albert Sabin Way, Cincinnati, OH 45267-0558, USA
| | | | | | | | | |
Collapse
|
49
|
Otis JS, Guidot DM. Procysteine stimulates expression of key anabolic factors and reduces plantaris atrophy in alcohol-fed rats. Alcohol Clin Exp Res 2009; 33:1450-9. [PMID: 19426167 DOI: 10.1111/j.1530-0277.2009.00975.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Long-term alcohol ingestion may produce severe oxidant stress and lead to skeletal muscle dysfunction. Emerging evidence has suggested that members of the interleukin-6 (IL-6) family of cytokines play diverse roles in the regulation of skeletal muscle mass. Thus, our goals were (i) to minimize the degree of oxidant stress and attenuate atrophy by supplementing the diets of alcohol-fed rats with the glutathione precursor, procysteine, and (ii) to identify the roles of IL-6 family members in alcoholic myopathy. METHODS Age- and gender-matched Sprague-Dawley rats were fed the Lieber-DeCarli liquid diet containing either alcohol or an isocaloric substitution (control diet) for 35 weeks. Subgroups of alcohol-fed rats received procysteine (0.35%, w/v) for the final 12 weeks. Plantaris morphology was assessed by hematoxylin and eosin staining. Major components of glutathione metabolism were determined using assay kits. Real-time PCR was used to determine expression levels of several genes. RESULTS Plantaris muscles from alcohol-fed rats displayed extensive atrophy, as well as decreased glutathione levels, decreased activities of glutathione reductase and glutathione peroxidase, decreased superoxide dismutase (SOD)-2 (Mn-SOD2), and increased NADPH oxidase-1 gene expression-each indicative of significant oxidant stress. Alcohol also induced gene expression of catabolic factors including IL-6, oncostatin M, atrogin-1, muscle ring finger protein-1, and IGFBP-1. Procysteine treatment attenuated plantaris atrophy, restored glutathione levels, and increased catalase, Cu/Zn-SOD1, and Mn-SOD2 mRNA expression, but did not reduce other markers of oxidant stress or levels of these catabolic factors. Instead, procysteine stimulated gene expression of anabolic factors such as insulin-like growth factor-1, ciliary neurotrophic factor, and cardiotrophin-1. CONCLUSIONS Procysteine significantly attenuated, but did not completely abrogate, alcohol-induced oxidant stress or catabolic factors. Rather, procysteine minimized the extent of plantaris atrophy by inducing components of several anabolic pathways. Therefore, anti-oxidant treatments such as procysteine supplementation may benefit individuals with alcoholic myopathy.
Collapse
Affiliation(s)
- Jeffrey S Otis
- Center for Emory University School of Medicine-Pulmonary, Allergy and Critical Care Medicine and Atlanta VA Medical Center, Decatur, Georgia 30002, USA.
| | | |
Collapse
|