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Cardaci TD, VanderVeen BN, Huss AR, Bullard BM, Velázquez KT, Frizzell N, Carson JA, Price RL, Murphy EA. Decreased skeletal muscle intramyocellular lipid droplet-mitochondrial contact contributes to myosteatosis in cancer cachexia. Am J Physiol Cell Physiol 2024; 327:C684-C697. [PMID: 39010842 DOI: 10.1152/ajpcell.00345.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/20/2024] [Accepted: 07/08/2024] [Indexed: 07/17/2024]
Abstract
Cancer cachexia, the unintentional loss of lean mass, contributes to functional dependency, poor treatment outcomes, and decreased survival. Although its pathogenicity is multifactorial, metabolic dysfunction remains a hallmark of cachexia. However, significant knowledge gaps exist in understanding the role of skeletal muscle lipid metabolism and dynamics in this condition. We examined skeletal muscle metabolic dysfunction, intramyocellular lipid droplet (LD) content, LD morphology and subcellular distribution, and LD-mitochondrial interactions using the Lewis lung carcinoma (LLC) murine model of cachexia. C57/BL6 male mice (n = 20) were implanted with LLC cells (106) in the right flank or underwent PBS sham injections. Skeletal muscle was excised for transmission electron microscopy (TEM; soleus), oil red O/lipid staining [tibialis anterior (TA)], and protein (gastrocnemius). LLC mice had a greater number (232%; P = 0.006) and size (130%; P = 0.023) of intramyocellular LDs further supported by increased oil-red O positive (87%; P = 0.0109) and "very high" oil-red O positive (178%; P = 0.0002) fibers compared with controls and this was inversely correlated with fiber size (R2 = 0.5294; P < 0.0001). Morphological analyses of LDs show increased elongation and complexity [aspect ratio: intermyofibrillar (IMF) = 9%, P = 0.046) with decreases in circularity [circularity: subsarcolemmal (SS) = 6%, P = 0.042] or roundness (roundness: whole = 10%, P = 0.033; IMF = 8%, P = 0.038) as well as decreased LD-mitochondria touch (-15%; P = 0.006), contact length (-38%; P = 0.036), and relative contact (86%; P = 0.004). Furthermore, dysregulation in lipid metabolism (adiponectin, CPT1b) and LD-associated proteins, perilipin-2 and perilipin-5, in cachectic muscle (P < 0.05) were observed. Collectively, we provide evidence that skeletal muscle myosteatosis, altered LD morphology, and decreased LD-mitochondrial interactions occur in a preclinical model of cancer cachexia.NEW & NOTEWORTHY We sought to advance our understanding of skeletal muscle lipid metabolism and dynamics in cancer cachexia. Cachexia increased the number and size of intramyocellular lipid droplets (LDs). Furthermore, decreases in LD-mitochondrial touch, contact length, and relative contact along with increased LD shape complexity with decreases in circularity and roundness. Dysregulation in lipid metabolism and LD-associated proteins was also documented. Collectively, we show that myosteatosis, altered LD morphology, and decreased LD-mitochondrial interactions occur in cancer cachexia.
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Affiliation(s)
- Thomas D Cardaci
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, United States
| | - Brandon N VanderVeen
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, United States
| | - Alexander R Huss
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, United States
| | - Brooke M Bullard
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, United States
| | - Kandy T Velázquez
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, United States
- Columbia Department of Veterans Affairs Health Care System, Columbia, South Carolina, United States
| | - Norma Frizzell
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, South Carolina, United States
| | - James A Carson
- Department of Kinesiology and Sports Management, JL Huffines Institute for Sports Medicine & Human Performance, Texas A&M University, College Station, Texas, United States
| | - Robert L Price
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, South Carolina, United States
| | - E Angela Murphy
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, United States
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Shen KC, Collins KH, Ferey JL, Fappi A, McCormick JJ, Mittendorfer B, Guilak F, Meyer GA. Excess Intramyocellular Lipid Does Not Affect Muscle Fiber Biophysical Properties in Mice or People With Metabolically Abnormal Obesity. Diabetes 2024; 73:1266-1277. [PMID: 38701374 PMCID: PMC11262043 DOI: 10.2337/db23-0991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 04/25/2024] [Indexed: 05/05/2024]
Abstract
Observational studies have shown correlations between intramyocellular lipid (IMCL) content and muscle strength and contractile function in people with metabolically abnormal obesity. However, a clear physiologic mechanism for this association is lacking, and causation is debated. We combined immunofluorescent confocal imaging with force measurements on permeabilized muscle fibers from metabolically normal and metabolically abnormal mice and people with metabolically normal (defined as normal fasting plasma glucose and glucose tolerance) and metabolically abnormal (defined as prediabetes and type 2 diabetes) overweight/obesity to evaluate relationships among myocellular lipid droplet characteristics (droplet size and density) and biophysical (active contractile and passive viscoelastic) properties. The fiber type specificity of lipid droplet parameters varied by metabolic status and by species. It was different between mice and people across the board and different between people of different metabolic status. However, despite considerable quantities of IMCL in the metabolically abnormal groups, there were no significant differences in peak active tension or passive viscoelasticity between the metabolically abnormal and control groups in mice or people. Additionally, there were no significant relationships among IMCL parameters and biophysical variables. Thus, we conclude that IMCL accumulation per se does not impact muscle fiber biophysical properties or physically impede contraction. ARTICLE HIGHLIGHTS
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Affiliation(s)
- Karen C. Shen
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO
| | - Kelsey H. Collins
- Department of Orthopedic Surgery, Washington University School of Medicine, St. Louis, MO
- Shriners Hospital for Children, St. Louis, MO
| | - Jeremie L.A. Ferey
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO
| | - Alan Fappi
- Center for Human Nutrition at Washington University School of Medicine, St. Louis, MO
| | - Jeremy J. McCormick
- Department of Orthopedic Surgery, Washington University School of Medicine, St. Louis, MO
| | - Bettina Mittendorfer
- Center for Human Nutrition at Washington University School of Medicine, St. Louis, MO
| | - Farshid Guilak
- Department of Orthopedic Surgery, Washington University School of Medicine, St. Louis, MO
- Shriners Hospital for Children, St. Louis, MO
| | - Gretchen A. Meyer
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO
- Shriners Hospital for Children, St. Louis, MO
- Departments of Neurology and Biomedical Engineering, Washington University School of Medicine, St. Louis, MO
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Fan H, Tan Y. Lipid Droplet-Mitochondria Contacts in Health and Disease. Int J Mol Sci 2024; 25:6878. [PMID: 38999988 PMCID: PMC11240910 DOI: 10.3390/ijms25136878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 06/19/2024] [Accepted: 06/20/2024] [Indexed: 07/14/2024] Open
Abstract
The orchestration of cellular metabolism and redox balance is a complex, multifaceted process crucial for maintaining cellular homeostasis. Lipid droplets (LDs), once considered inert storage depots for neutral lipids, are now recognized as dynamic organelles critical in lipid metabolism and energy regulation. Mitochondria, the powerhouses of the cell, play a central role in energy production, metabolic pathways, and redox signaling. The physical and functional contacts between LDs and mitochondria facilitate a direct transfer of lipids, primarily fatty acids, which are crucial for mitochondrial β-oxidation, thus influencing energy homeostasis and cellular health. This review highlights recent advances in understanding the mechanisms governing LD-mitochondria interactions and their regulation, drawing attention to proteins and pathways that mediate these contacts. We discuss the physiological relevance of these interactions, emphasizing their role in maintaining energy and redox balance within cells, and how these processes are critical in response to metabolic demands and stress conditions. Furthermore, we explore the pathological implications of dysregulated LD-mitochondria interactions, particularly in the context of metabolic diseases such as obesity, diabetes, and non-alcoholic fatty liver disease, and their potential links to cardiovascular and neurodegenerative diseases. Conclusively, this review provides a comprehensive overview of the current understanding of LD-mitochondria interactions, underscoring their significance in cellular metabolism and suggesting future research directions that could unveil novel therapeutic targets for metabolic and degenerative diseases.
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Affiliation(s)
- Hongjun Fan
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Yanjie Tan
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China
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Lian X, Cheng Y, Kang H. New insights of acylation stimulating protein in modulating the pathological progression of metabolic syndromes. Int Immunopharmacol 2024; 132:112018. [PMID: 38588630 DOI: 10.1016/j.intimp.2024.112018] [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: 02/01/2023] [Revised: 04/01/2024] [Accepted: 04/03/2024] [Indexed: 04/10/2024]
Abstract
Obesity is associated with insulin resistance, hypertension, and coronary artery diseases which are grouped as metabolic syndrome. Rather than being a storage for energy, the adipocytes could synthesis and secret diverse hormones and molecules, named as adipokines. Under obese status, the adipocytes are dysfunctional with excessively producing the inflammatory related cytokines, such as interleukin 1 (IL-1), IL-6, and tumor necrosis factor α (TNF-α). Concerning on the vital role of adipokines, it is proposed that one of the critical pathological factors of obesity is the dysfunctional adipocytic pathways. Among these adipokines, acylation stimulating protein, as an adipokine synthesized by adipocytes during the process of cell differentiation, is shown to activate the metabolism of triglyceride (TG) by regulating the catabolism of glucose and free fatty acid (FFA). Recent attention has paid to explore the underlying mechanism whereby acylation stimulating protein influences the biological function of adipocyte and the pathological development of obesity. In the present review, we summarized the progression of acylation stimulating protein in modulating the physiological and hormonal catabolism which affects fat distribution. Furthermore, the potential mechanisms which acylation stimulating protein regulates the metabolism of adipose tissue and the process of metabolic syndrome were also summarized.
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Affiliation(s)
- Xi Lian
- Department of Anesthesia Surgery, the First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China
| | - Ye Cheng
- Department of Cardiology, the Xiamen Cardiovascular Hospital of Xiamen University, Xiamen, Fujian, China; School of Pharmacy, Health Science Center, Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Huiyuan Kang
- Department of Cardiology, the Xiamen Cardiovascular Hospital of Xiamen University, Xiamen, Fujian, China.
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Parry HA, Willingham TB, Giordano KA, Kim Y, Qazi S, Knutson JR, Combs CA, Glancy B. Impact of capillary and sarcolemmal proximity on mitochondrial structure and energetic function in skeletal muscle. J Physiol 2024; 602:1967-1986. [PMID: 38564214 PMCID: PMC11068488 DOI: 10.1113/jp286246] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 03/08/2024] [Indexed: 04/04/2024] Open
Abstract
Mitochondria within skeletal muscle cells are located either between the muscle contractile apparatus (interfibrillar mitochondria, IFM) or beneath the cell membrane (subsarcolemmal mitochondria, SSM), with several structural and functional differences reported between IFM and SSM. However, recent 3D imaging studies demonstrate that mitochondria are particularly concentrated in the proximity of capillaries embedded in sarcolemmal grooves rather than in proximity to the sarcolemma itself (paravascular mitochondria, PVM). To evaluate the impact of capillary vs. sarcolemmal proximity, we compared the structure and function of skeletal muscle mitochondria located either lateral to embedded capillaries (PVM), adjacent to the sarcolemma but not in PVM pools (SSM) or interspersed between sarcomeres (IFM). Mitochondrial morphology and interactions were assessed by 3D electron microscopy coupled with machine learning segmentation, whereas mitochondrial energy conversion was assessed by two-photon microscopy of mitochondrial membrane potential, content, calcium, NADH redox and flux in live, intact cells. Structurally, although PVM and SSM were similarly larger than IFM, PVM were larger, rounder and had more physical connections to neighbouring mitochondria compared to both IFM and SSM. Functionally, PVM had similar or greater basal NADH flux compared to SSM and IFM, respectively, despite a more oxidized NADH pool and a greater membrane potential, signifying a greater activation of the electron transport chain in PVM. Together, these data indicate that proximity to capillaries has a greater impact on resting mitochondrial energy conversion and distribution in skeletal muscle than the sarcolemma alone. KEY POINTS: Capillaries have a greater impact on mitochondrial energy conversion in skeletal muscle than the sarcolemma. Paravascular mitochondria are larger, and the outer mitochondrial membrane is more connected with neighbouring mitochondria. Interfibrillar mitochondria are longer and have greater contact sites with other organelles (i.e. sarcoplasmic reticulum and lipid droplets). Paravascular mitochondria have greater activation of oxidative phosphorylation than interfibrillar mitochondria at rest, although this is not regulated by calcium.
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Affiliation(s)
- Hailey A. Parry
- National Lung, Blood, and Heart Institute, National Institutes of Health, Bethesda, MD, USA
| | - T. Bradley Willingham
- National Lung, Blood, and Heart Institute, National Institutes of Health, Bethesda, MD, USA
- Shephard Center’s Virginia C. Crawford Research Institute, Atlanta, GA, USA
| | | | - Yuho Kim
- National Lung, Blood, and Heart Institute, National Institutes of Health, Bethesda, MD, USA
- University of Massachusetts, Lowell, MA,USA
| | - Shureed Qazi
- National Lung, Blood, and Heart Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jay R. Knutson
- National Lung, Blood, and Heart Institute, National Institutes of Health, Bethesda, MD, USA
| | - Christian A. Combs
- National Lung, Blood, and Heart Institute, National Institutes of Health, Bethesda, MD, USA
| | - Brian Glancy
- National Lung, Blood, and Heart Institute, National Institutes of Health, Bethesda, MD, USA
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
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Dudka W, Salo VT, Mahamid J. Zooming into lipid droplet biology through the lens of electron microscopy. FEBS Lett 2024; 598:1127-1142. [PMID: 38726814 DOI: 10.1002/1873-3468.14899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/08/2024] [Accepted: 04/24/2024] [Indexed: 05/25/2024]
Abstract
Electron microscopy (EM), in its various flavors, has significantly contributed to our understanding of lipid droplets (LD) as central organelles in cellular metabolism. For example, EM has illuminated that LDs, in contrast to all other cellular organelles, are uniquely enclosed by a single phospholipid monolayer, revealed the architecture of LD contact sites with different organelles, and provided near-atomic resolution maps of key enzymes that regulate neutral lipid biosynthesis and LD biogenesis. In this review, we first provide a brief history of pivotal findings in LD biology unveiled through the lens of an electron microscope. We describe the main EM techniques used in the context of LD research and discuss their current capabilities and limitations, thereby providing a foundation for utilizing suitable EM methodology to address LD-related questions with sufficient level of structural preservation, detail, and resolution. Finally, we highlight examples where EM has recently been and is expected to be instrumental in expanding the frontiers of LD biology.
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Affiliation(s)
- Wioleta Dudka
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Veijo T Salo
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Cell Biology and Biophysics Unit, EMBL, Heidelberg, Germany
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7
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Bórquez JC, Díaz-Castro F, La Fuente FPD, Espinoza K, Figueroa AM, Martínez-Ruíz I, Hernández V, López-Soldado I, Ventura R, Domingo JC, Bosch M, Fajardo A, Sebastián D, Espinosa A, Pol A, Zorzano A, Cortés V, Hernández-Alvarez MI, Troncoso R. Mitofusin-2 induced by exercise modifies lipid droplet-mitochondria communication, promoting fatty acid oxidation in male mice with NAFLD. Metabolism 2024; 152:155765. [PMID: 38142958 DOI: 10.1016/j.metabol.2023.155765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/09/2023] [Accepted: 12/16/2023] [Indexed: 12/26/2023]
Abstract
BACKGROUND AND AIM The excessive accumulation of lipid droplets (LDs) is a defining characteristic of nonalcoholic fatty liver disease (NAFLD). The interaction between LDs and mitochondria is functionally important for lipid metabolism homeostasis. Exercise improves NAFLD, but it is not known if it has an effect on hepatic LD-mitochondria interactions. Here, we investigated the influence of exercise on LD-mitochondria interactions and its significance in the context of NAFLD. APPROACH AND RESULTS Mice were fed high-fat diet (HFD) or HFD-0.1 % methionine and choline-deficient diet (MCD) to emulate simple hepatic steatosis or non-alcoholic steatohepatitis, respectively. In both models, aerobic exercise decreased the size of LDs bound to mitochondria and the number of LD-mitochondria contacts. Analysis showed that the effects of exercise on HOMA-IR and liver triglyceride levels were independent of changes in body weight, and a positive correlation was observed between the number of LD-mitochondria contacts and NAFLD severity and with the lipid droplet size bound to mitochondria. Cellular fractionation studies revealed that ATP-coupled respiration and fatty acid oxidation (FAO) were greater in hepatic peridroplet mitochondria (PDM) from HFD-fed exercised mice than from equivalent sedentary mice. Finally, exercise increased FAO and mitofusin-2 abundance exclusively in PDM through a mechanism involving the curvature of mitochondrial membranes and the abundance of saturated lipids. Accordingly, hepatic mitofusin-2 ablation prevented exercise-induced FAO in PDM. CONCLUSIONS This study demonstrates that aerobic exercise has beneficial effects in murine NAFLD models by lessening the interactions between hepatic LDs and mitochondria, and by decreasing LD size, correlating with a reduced severity of NAFLD. Additionally, aerobic exercise increases FAO in PDM and this process is reliant on Mfn-2 enrichment, which modifies LD-mitochondria communication.
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Affiliation(s)
- Juan Carlos Bórquez
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Chile
| | - Francisco Díaz-Castro
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Chile
| | - Francisco Pino-de La Fuente
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Chile
| | - Karla Espinoza
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Chile
| | - Ana María Figueroa
- Department of Nutrition, Diabetes and Metabolism, Pontificia Universidad Católica de Chile, Chile
| | - Inma Martínez-Ruíz
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; Institut de Biomedicina de la Universitat de Barcelona IBUB, Barcelona, Spain
| | - Vanessa Hernández
- Institute for Research in Biomedicine (IRB Barcelona). The Barcelona Institute of Science and Technology, Barcelona (BIST), Spain
| | - Iliana López-Soldado
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; Institut de Biomedicina de la Universitat de Barcelona IBUB, Barcelona, Spain
| | - Raúl Ventura
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; Institut de Biomedicina de la Universitat de Barcelona IBUB, Barcelona, Spain
| | - Joan Carles Domingo
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Marta Bosch
- Cell Compartments and Signaling Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Alba Fajardo
- Cell Compartments and Signaling Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - David Sebastián
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, Barcelona, Spain
| | - Alejandra Espinosa
- Escuela de Medicina, Campus San Felipe, Universidad de Valparaíso, Chile; Department of Medical Technology, Faculty of Medicine, University of Chile, Chile
| | - Albert Pol
- Cell Compartments and Signaling Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Antonio Zorzano
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona). The Barcelona Institute of Science and Technology, Barcelona (BIST), Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Spain
| | - Víctor Cortés
- Department of Nutrition, Diabetes and Metabolism, Pontificia Universidad Católica de Chile, Chile.
| | - María Isabel Hernández-Alvarez
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; Institut de Biomedicina de la Universitat de Barcelona IBUB, Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Spain.
| | - Rodrigo Troncoso
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Chile; Advanced Center for Chronic Diseases (ACCDiS), Universidad de Chile, Chile; Obesity-induced Accelerated Aging (ObAGE), Universidad de Chile, Chile.
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Wang Y, Wang J, Tao SY, Liang Z, Xie R, Liu NN, Deng R, Zhang Y, Deng D, Jiang G. Mitochondrial damage-associated molecular patterns: A new insight into metabolic inflammation in type 2 diabetes mellitus. Diabetes Metab Res Rev 2024; 40:e3733. [PMID: 37823338 DOI: 10.1002/dmrr.3733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/18/2023] [Accepted: 09/08/2023] [Indexed: 10/13/2023]
Abstract
The pathogenesis of diabetes is accompanied by increased levels of inflammatory factors, also known as "metabolic inflammation", which runs through the whole process of the occurrence and development of the disease. Mitochondria, as the key site of glucose and lipid metabolism, is often accompanied by mitochondrial function damage in type 2 diabetes mellitus (T2DM). Damaged mitochondria release pro-inflammatory factors through damage-related molecular patterns that activate inflammation pathways and reactions to oxidative stress, further aggravate metabolic disorders, and form a vicious circle. Currently, the pathogenesis of diabetes is still unclear, and clinical treatment focuses primarily on symptomatic intervention of the internal environment of disorders of glucose and lipid metabolism with limited clinical efficacy. The proinflammatory effect of mitochondrial damage-associated molecular pattern (mtDAMP) in T2DM provides a new research direction for exploring the pathogenesis and intervention targets of T2DM. Therefore, this review covers the most recent findings on the molecular mechanism and related signalling cascades of inflammation caused by mtDAMP in T2DM and discusses its pathogenic role of it in the pathological process of T2DM to search potential intervention targets.
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Affiliation(s)
- Yan Wang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
- Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Jingwu Wang
- Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Si-Yu Tao
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | | | - Rong Xie
- Xinjiang Medical University, Urumqi, China
| | - Nan-Nan Liu
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Ruxue Deng
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Yuelin Zhang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Deqiang Deng
- Department of Endocrinology, Urumqi Hospital of Traditional Chinese Medicine, Urumqi, China
| | - Guangjian Jiang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
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Larsen JK, Kruse R, Sahebekhtiari N, Moreno-Justicia R, Gomez Jorba G, Petersen MH, de Almeida ME, Ørtenblad N, Deshmukh AS, Højlund K. High-throughput proteomics uncovers exercise training and type 2 diabetes-induced changes in human white adipose tissue. SCIENCE ADVANCES 2023; 9:eadi7548. [PMID: 38019916 PMCID: PMC10686561 DOI: 10.1126/sciadv.adi7548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 10/30/2023] [Indexed: 12/01/2023]
Abstract
White adipose tissue (WAT) is important for metabolic homeostasis. We established the differential proteomic signatures of WAT in glucose-tolerant lean and obese individuals and patients with type 2 diabetes (T2D) and the response to 8 weeks of high-intensity interval training (HIIT). Using a high-throughput and reproducible mass spectrometry-based proteomics pipeline, we identified 3773 proteins and found that most regulated proteins displayed progression in markers of dysfunctional WAT from lean to obese to T2D individuals and were highly associated with clinical measures such as insulin sensitivity and HbA1c. We propose that these distinct markers could serve as potential clinical biomarkers. HIIT induced only minor changes in the WAT proteome. This included an increase in WAT ferritin levels independent of obesity and T2D, and WAT ferritin levels were strongly correlated with individual insulin sensitivity. Together, we report a proteomic signature of WAT related to obesity and T2D and highlight an unrecognized role of human WAT iron metabolism in exercise training adaptations.
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Affiliation(s)
- Jeppe Kjærgaard Larsen
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Rikke Kruse
- Steno Diabetes Center Odense, Odense University Hospital, Odense C, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense C, Denmark
| | - Navid Sahebekhtiari
- Steno Diabetes Center Odense, Odense University Hospital, Odense C, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense C, Denmark
| | - Roger Moreno-Justicia
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Gerard Gomez Jorba
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Maria H. Petersen
- Steno Diabetes Center Odense, Odense University Hospital, Odense C, Denmark
| | - Martin E. de Almeida
- Steno Diabetes Center Odense, Odense University Hospital, Odense C, Denmark
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Niels Ørtenblad
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Atul S. Deshmukh
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Kurt Højlund
- Steno Diabetes Center Odense, Odense University Hospital, Odense C, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense C, Denmark
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Knudsen CB, Nielsen J, Ørtenblad N, Mohr M, Overgaard K, Vigh-Larsen JF. No net utilization of intramuscular lipid droplets during repeated high-intensity intermittent exercise. Am J Physiol Endocrinol Metab 2023; 325:E700-E710. [PMID: 37877795 DOI: 10.1152/ajpendo.00298.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 10/19/2023] [Accepted: 10/20/2023] [Indexed: 10/26/2023]
Abstract
Intramuscular lipids are stored as subsarcolemmal or intramyofibrillar droplets with potential diverse roles in energy metabolism. We examined intramuscular lipid utilization through transmission electron microscopy during repeated high-intensity intermittent exercise, an aspect that is hitherto unexplored. Seventeen moderately to well-trained males underwent three periods (EX1-EX3) of 10 × 45-s high-intensity cycling [∼100%-120% Wattmax (Wmax)] combined with maximal repeated sprints (∼250%-300% Wmax). M. vastus lateralis biopsies were obtained at baseline, after EX1, and EX3. During the complete exercise session, no net decline in either subsarcolemmal or intermyofibrillar lipid volume density occurred. However, a temporal relationship emerged for subsarcolemmal lipids with an ∼11% increase in droplet size after EX1 (P = 0.024), which reverted to baseline levels after EX3 accompanied by an ∼30% reduction in the numerical density of subsarcolemmal lipid droplets compared with both baseline (P = 0.019) and after EX1 (P = 0.018). Baseline distinctions were demonstrated with an approximately twofold higher intermyofibrillar lipid volume in type 1 versus type 2 fibers (P = 0.008), mediated solely by a higher number rather than the size of lipid droplets (P < 0.001). No fiber-type-specific differences were observed in subsarcolemmal lipid volume although type 2 fibers exhibited ∼17% larger droplets (P = 0.034) but a lower numerical density (main effect; P = 0.010) including 3% less droplets at baseline. Collectively, these findings suggest that intramuscular lipids do not serve as an important substrate during high-intensity intermittent exercise; however, the repeated exercise pattern mediated a temporal remodeling of the subsarcolemmal lipid pool. Furthermore, fiber-type- and compartment-specific differences were found at baseline underscoring the heterogeneity in lipid droplet deposition.NEW & NOTEWORTHY Undertaking a severe repeated high-intensity intermittent exercise protocol led to no net decline in neither subsarcolemmal nor intermyofibrillar lipid content in the thigh muscle of young moderately to well-trained participants. However, a temporal remodeling of the subsarcolemmal pool of lipid droplets did occur indicative of potential transient lipid accumulation. Moreover, baseline fiber-type distinctions in subcellular lipid droplet deposition were present underscoring the diversity in lipid droplet storage among fiber types and subcellular regions.
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Affiliation(s)
- Christian B Knudsen
- Department of Public Health, Research Unit for Exercise Biology, Aarhus University, Aarhus, Denmark
| | - Joachim Nielsen
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Niels Ørtenblad
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Magni Mohr
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
- Centre of Health Science, University of the Faroe Islands, Tórshavn, Faroe Islands
| | - Kristian Overgaard
- Department of Public Health, Research Unit for Exercise Biology, Aarhus University, Aarhus, Denmark
| | - Jeppe F Vigh-Larsen
- Department of Public Health, Research Unit for Exercise Biology, Aarhus University, Aarhus, Denmark
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
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Smith JAB, Murach KA, Dyar KA, Zierath JR. Exercise metabolism and adaptation in skeletal muscle. Nat Rev Mol Cell Biol 2023; 24:607-632. [PMID: 37225892 PMCID: PMC10527431 DOI: 10.1038/s41580-023-00606-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2023] [Indexed: 05/26/2023]
Abstract
Viewing metabolism through the lens of exercise biology has proven an accessible and practical strategy to gain new insights into local and systemic metabolic regulation. Recent methodological developments have advanced understanding of the central role of skeletal muscle in many exercise-associated health benefits and have uncovered the molecular underpinnings driving adaptive responses to training regimens. In this Review, we provide a contemporary view of the metabolic flexibility and functional plasticity of skeletal muscle in response to exercise. First, we provide background on the macrostructure and ultrastructure of skeletal muscle fibres, highlighting the current understanding of sarcomeric networks and mitochondrial subpopulations. Next, we discuss acute exercise skeletal muscle metabolism and the signalling, transcriptional and epigenetic regulation of adaptations to exercise training. We address knowledge gaps throughout and propose future directions for the field. This Review contextualizes recent research of skeletal muscle exercise metabolism, framing further advances and translation into practice.
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Affiliation(s)
- Jonathon A B Smith
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Kevin A Murach
- Molecular Mass Regulation Laboratory, Exercise Science Research Center, Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR, USA
| | - Kenneth A Dyar
- Metabolic Physiology, Institute for Diabetes and Cancer, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Juleen R Zierath
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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Ispoglou T, Wilson O, McCullough D, Aldrich L, Ferentinos P, Lyall G, Stavropoulos-Kalinoglou A, Duckworth L, Brown MA, Sutton L, Potts AJ, Archbold V, Hargreaves J, McKenna J. A Narrative Review of Non-Pharmacological Strategies for Managing Sarcopenia in Older Adults with Cardiovascular and Metabolic Diseases. BIOLOGY 2023; 12:892. [PMID: 37508325 PMCID: PMC10376679 DOI: 10.3390/biology12070892] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 07/30/2023]
Abstract
This narrative review examines the mechanisms underlying the development of cardiovascular disease (CVD) and metabolic diseases (MDs), along with their association with sarcopenia. Furthermore, non-pharmacological interventions to address sarcopenia in patients with these conditions are suggested. The significance of combined training in managing metabolic disease and secondary sarcopenia in type II diabetes mellitus is emphasized. Additionally, the potential benefits of resistance and aerobic training are explored. This review emphasises the role of nutrition in addressing sarcopenia in patients with CVD or MDs, focusing on strategies such as optimising protein intake, promoting plant-based protein sources, incorporating antioxidant-rich foods and omega-3 fatty acids and ensuring sufficient vitamin D levels. Moreover, the potential benefits of targeting gut microbiota through probiotics and prebiotic fibres in sarcopenic individuals are considered. Multidisciplinary approaches that integrate behavioural science are explored to enhance the uptake and sustainability of behaviour-based sarcopenia interventions. Future research should prioritise high-quality randomized controlled trials to refine exercise and nutritional interventions and investigate the incorporation of behavioural science into routine practices. Ultimately, a comprehensive and multifaceted approach is essential to improve health outcomes, well-being and quality of life in older adults with sarcopenia and coexisting cardiovascular and metabolic diseases.
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Affiliation(s)
| | - Oliver Wilson
- Carnegie School of Sport, Leeds Beckett University, Leeds LS6 3QQ, UK
| | | | - Luke Aldrich
- Carnegie School of Sport, Leeds Beckett University, Leeds LS6 3QQ, UK
| | | | - Gemma Lyall
- Carnegie School of Sport, Leeds Beckett University, Leeds LS6 3QQ, UK
| | | | - Lauren Duckworth
- Carnegie School of Sport, Leeds Beckett University, Leeds LS6 3QQ, UK
| | - Meghan A Brown
- Carnegie School of Sport, Leeds Beckett University, Leeds LS6 3QQ, UK
| | - Louise Sutton
- Carnegie School of Sport, Leeds Beckett University, Leeds LS6 3QQ, UK
| | - Alexandra J Potts
- Carnegie School of Sport, Leeds Beckett University, Leeds LS6 3QQ, UK
| | - Victoria Archbold
- Carnegie School of Sport, Leeds Beckett University, Leeds LS6 3QQ, UK
| | - Jackie Hargreaves
- Carnegie School of Sport, Leeds Beckett University, Leeds LS6 3QQ, UK
| | - Jim McKenna
- Carnegie School of Sport, Leeds Beckett University, Leeds LS6 3QQ, UK
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