1
|
Delfinis LJ, Ogilvie LM, Khajehzadehshoushtar S, Gandhi S, Garibotti MC, Thuhan AK, Matuszewska K, Pereira M, Jones RG, Cheng AJ, Hawke TJ, Greene NP, Murach KA, Simpson JA, Petrik J, Perry CGR. Muscle weakness and mitochondrial stress occur before severe metastasis in a novel mouse model of ovarian cancer cachexia. Mol Metab 2024; 86:101976. [PMID: 38925248 DOI: 10.1016/j.molmet.2024.101976] [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: 04/11/2024] [Revised: 06/03/2024] [Accepted: 06/21/2024] [Indexed: 06/28/2024] Open
Abstract
OBJECTIVES A high proportion of women with advanced epithelial ovarian cancer (EOC) experience weakness and cachexia. This relationship is associated with increased morbidity and mortality. EOC is the most lethal gynecological cancer, yet no preclinical cachexia model has demonstrated the combined hallmark features of metastasis, ascites development, muscle loss and weakness in adult immunocompetent mice. METHODS Here, we evaluated a new model of ovarian cancer-induced cachexia with the advantages of inducing cancer in adult immunocompetent C57BL/6J mice through orthotopic injections of EOC cells in the ovarian bursa. We characterized the development of metastasis, ascites, muscle atrophy, muscle weakness, markers of inflammation, and mitochondrial stress in the tibialis anterior (TA) and diaphragm ∼45, ∼75 and ∼90 days after EOC injection. RESULTS Primary ovarian tumour sizes were progressively larger at each time point while severe metastasis, ascites development, and reductions in body, fat and muscle weights occurred by 90 Days. There were no changes in certain inflammatory (TNFα), atrogene (MURF1 and Atrogin) or GDF15 markers within both muscles whereas IL-6 was increased at 45 and 90 Day groups in the diaphragm. TA weakness in 45 Day preceded atrophy and metastasis that were observed later (75 and 90 Day, respectively). The diaphragm demonstrated both weakness and atrophy in 45 Day. In both muscles, this pre-severe-metastatic muscle weakness corresponded with considerable reprogramming of gene pathways related to mitochondrial bioenergetics as well as reduced functional measures of mitochondrial pyruvate oxidation and creatine-dependent ADP/ATP cycling as well as increased reactive oxygen species emission (hydrogen peroxide). Remarkably, muscle force per unit mass at 90 days was partially restored in the TA despite the presence of atrophy and severe metastasis. In contrast, the diaphragm demonstrated progressive weakness. At this advanced stage, mitochondrial pyruvate oxidation in both muscles exceeded control mice suggesting an apparent metabolic super-compensation corresponding with restored indices of creatine-dependent adenylate cycling. CONCLUSIONS This mouse model demonstrates the concurrent development of cachexia and metastasis that occurs in women with EOC. The model provides physiologically relevant advantages of inducing tumour development within the ovarian bursa in immunocompetent adult mice. Moreover, the model reveals that muscle weakness in both TA and diaphragm precedes severe metastasis while weakness also precedes atrophy in the TA. An underlying mitochondrial bioenergetic stress corresponded with this early weakness. Collectively, these discoveries can direct new research towards the development of therapies that target pre-atrophy and pre-severe-metastatic weakness during EOC in addition to therapies targeting cachexia.
Collapse
Affiliation(s)
- Luca J Delfinis
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada.
| | - Leslie M Ogilvie
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada.
| | | | - Shivam Gandhi
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada.
| | - Madison C Garibotti
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada.
| | - Arshdeep K Thuhan
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada.
| | - Kathy Matuszewska
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada.
| | - Madison Pereira
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada.
| | - Ronald G Jones
- Exercise Science Research Center, Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, AR, USA.
| | - Arthur J Cheng
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada.
| | - Thomas J Hawke
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada.
| | - Nicholas P Greene
- Exercise Science Research Center, Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, AR, USA.
| | - Kevin A Murach
- Exercise Science Research Center, Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, AR, USA.
| | - Jeremy A Simpson
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada.
| | - Jim Petrik
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada.
| | - Christopher G R Perry
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada.
| |
Collapse
|
2
|
Ye B, Chen B, Guo C, Xiong N, Huang Y, Li M, Lai Y, Li J, Zhou M, Wang S, Wang S, Yang N, Zhang H. C5a-C5aR1 axis controls mitochondrial fission to promote podocyte injury in lupus nephritis. Mol Ther 2024; 32:1540-1560. [PMID: 38449312 PMCID: PMC11081871 DOI: 10.1016/j.ymthe.2024.03.003] [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: 10/19/2023] [Revised: 02/05/2024] [Accepted: 03/04/2024] [Indexed: 03/08/2024] Open
Abstract
Podocytes are essential to maintaining the integrity of the glomerular filtration barrier, but they are frequently affected in lupus nephritis (LN). Here, we show that the significant upregulation of Drp1S616 phosphorylation in podocytes promotes mitochondrial fission, leading to mitochondrial dysfunction and podocyte injury in LN. Inhibition or knockdown of Drp1 promotes mitochondrial fusion and protects podocytes from injury induced by LN serum. In vivo, pharmacological inhibition of Drp1 reduces the phosphorylation of Drp1S616 in podocytes in lupus-prone mice. Podocyte injury is reversed when Drp1 is inhibited, resulting in the alleviation of proteinuria. Mechanistically, complement component C5a (C5a) upregulates the phosphorylation of Drp1S616 and promotes mitochondrial fission in podocytes. Moreover, the expression of C5a receptor 1 (C5aR1) is notably upregulated in podocytes in LN. C5a-C5aR1 axis-controlled phosphorylation of Drp1S616 and mitochondrial fission are substantially suppressed when C5aR1 is knocked down by siRNA. Moreover, lupus-prone mice treated with C5aR inhibitor show reduced phosphorylation of Drp1S616 in podocytes, resulting in significantly less podocyte damage. Together, this study uncovers a novel mechanism by which the C5a-C5aR1 axis promotes podocyte injury by enhancing Drp1-mediated mitochondrial fission, which could have significant implications for the treatment of LN.
Collapse
Affiliation(s)
- Baokui Ye
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Binfeng Chen
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Chaohuan Guo
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Ningjing Xiong
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Yuefang Huang
- Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Mengyuan Li
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Yimei Lai
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Jin Li
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Mianjing Zhou
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Shuang Wang
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Shuyi Wang
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Niansheng Yang
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China.
| | - Hui Zhang
- Department of Rheumatology and Clinical Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China; Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China.
| |
Collapse
|
3
|
Delfinis LJ, Ogilvie LM, Khajehzadehshoushtar S, Gandhi S, Garibotti MC, Thuhan AK, Matuszewska K, Pereira M, Jones RG, Cheng AJ, Hawke TJ, Greene NP, Murach KA, Simpson JA, Petrik J, Perry CG. Muscle weakness and mitochondrial stress occur before metastasis in a novel mouse model of ovarian cancer cachexia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.08.588639. [PMID: 38645227 PMCID: PMC11030380 DOI: 10.1101/2024.04.08.588639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Objectives A high proportion of women with advanced epithelial ovarian cancer (EOC) experience weakness and cachexia. This relationship is associated with increased morbidity and mortality. EOC is the most lethal gynecological cancer, yet no preclinical cachexia model has demonstrated the combined hallmark features of metastasis, ascites development, muscle loss and weakness in adult immunocompetent mice. Methods Here, we evaluated a new model of ovarian cancer-induced cachexia with the advantages of inducing cancer in adult immunocompetent C57BL/6J mice through orthotopic injections of EOC cells in the ovarian bursa. We characterized the development of metastasis, ascites, muscle atrophy, muscle weakness, markers of inflammation, and mitochondrial stress in the tibialis anterior (TA) and diaphragm ~45, ~75 and ~90 days after EOC injection. Results Primary ovarian tumour sizes were progressively larger at each time point while robust metastasis, ascites development, and reductions in body, fat and muscle weights occurred by 90 Days. There were no changes in certain inflammatory (TNFα), atrogene (MURF1 and Atrogin) or GDF15 markers within both muscles whereas IL-6 was increased at 45 and 90 Day groups in the diaphragm. TA weakness in 45 Day preceded atrophy and metastasis that were observed later (75 and 90 Day, respectively). The diaphragm demonstrated both weakness and atrophy in 45 Day. In both muscles, this pre-metastatic muscle weakness corresponded with considerable reprogramming of gene pathways related to mitochondrial bioenergetics as well as reduced functional measures of mitochondrial pyruvate oxidation and creatine-dependent ADP/ATP cycling as well as increased reactive oxygen species emission (hydrogen peroxide). Remarkably, muscle force per unit mass at 90 days was partially restored in the TA despite the presence of atrophy and metastasis. In contrast, the diaphragm demonstrated progressive weakness. At this advanced stage, mitochondrial pyruvate oxidation in both muscles exceeded control mice suggesting an apparent metabolic super-compensation corresponding with restored indices of creatine-dependent adenylate cycling. Conclusion This mouse model demonstrates the concurrent development of cachexia and metastasis that occurs in women with EOC. The model provides physiologically relevant advantages of inducing tumour development within the ovarian bursa in immunocompetent adult mice. Moreover, the model reveals that muscle weakness in both TA and diaphragm precedes metastasis while weakness also precedes atrophy in the TA. An underlying mitochondrial bioenergetic stress corresponded with this early weakness. Collectively, these discoveries can direct new research towards the development of therapies that target pre-atrophy and pre-metastatic weakness during EOC in addition to therapies targeting cachexia.
Collapse
Affiliation(s)
- Luca J. Delfinis
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Leslie M. Ogilvie
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | | | - Shivam Gandhi
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Madison C. Garibotti
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Arshdeep K. Thuhan
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Kathy Matuszewska
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada
| | - Madison Pereira
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada
| | - Ronald G. Jones
- Exercise Science Research Center, Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, AR, USA
| | - Arthur J. Cheng
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Thomas J. Hawke
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Nicholas P. Greene
- Exercise Science Research Center, Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, AR, USA
| | - Kevin A. Murach
- Exercise Science Research Center, Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, AR, USA
| | - Jeremy A. Simpson
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Jim Petrik
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada
| | - Christopher G.R. Perry
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada
| |
Collapse
|
4
|
Bellissimo CA, Gandhi S, Castellani LN, Murugathasan M, Delfinis LJ, Thuhan A, Garibotti MC, Seo Y, Rebalka IA, Hsu HH, Sweeney G, Hawke TJ, Abdul-Sater AA, Perry CGR. The slow-release adiponectin analog ALY688-SR modifies early-stage disease development in the D2. mdx mouse model of Duchenne muscular dystrophy. Am J Physiol Cell Physiol 2024; 326:C1011-C1026. [PMID: 38145301 DOI: 10.1152/ajpcell.00638.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 12/18/2023] [Accepted: 12/18/2023] [Indexed: 12/26/2023]
Abstract
Fibrosis is associated with respiratory and limb muscle atrophy in Duchenne muscular dystrophy (DMD). Current standard of care partially delays the progression of this myopathy but there remains an unmet need to develop additional therapies. Adiponectin receptor agonism has emerged as a possible therapeutic target to lower inflammation and improve metabolism in mdx mouse models of DMD but the degree to which fibrosis and atrophy are prevented remain unknown. Here, we demonstrate that the recently developed slow-release peptidomimetic adiponectin analog, ALY688-SR, remodels the diaphragm of murine model of DMD on DBA background (D2.mdx) mice treated from days 7-28 of age during early stages of disease. ALY688-SR also lowered interleukin-6 (IL-6) mRNA but increased IL-6 and transforming growth factor-β1 (TGF-β1) protein contents in diaphragm, suggesting dynamic inflammatory remodeling. ALY688-SR alleviated mitochondrial redox stress by decreasing complex I-stimulated H2O2 emission. Treatment also attenuated fibrosis, fiber type-specific atrophy, and in vitro diaphragm force production in diaphragm suggesting a complex relationship between adiponectin receptor activity, muscle remodeling, and force-generating properties during the very early stages of disease progression in murine model of DMD on DBA background (D2.mdx) mice. In tibialis anterior, the modest fibrosis at this young age was not altered by treatment, and atrophy was not apparent at this young age. These results demonstrate that short-term treatment of ALY688-SR in young D2.mdx mice partially prevents fibrosis and fiber type-specific atrophy and lowers force production in the more disease-apparent diaphragm in relation to lower mitochondrial redox stress and heterogeneous responses in certain inflammatory markers. These diverse muscle responses to adiponectin receptor agonism in early stages of DMD serve as a foundation for further mechanistic investigations.NEW & NOTEWORTHY There are limited therapies for the treatment of Duchenne muscular dystrophy. As fibrosis involves an accumulation of collagen that replaces muscle fibers, antifibrotics may help preserve muscle function. We report that the novel adiponectin receptor agonist ALY688-SR prevents fibrosis in the diaphragm of D2.mdx mice with short-term treatment early in disease progression. These responses were related to altered inflammation and mitochondrial functions and serve as a foundation for the development of this class of therapy.
Collapse
MESH Headings
- Animals
- Mice
- Mice, Inbred mdx
- Muscular Dystrophy, Duchenne/drug therapy
- Muscular Dystrophy, Duchenne/genetics
- Muscular Dystrophy, Duchenne/pathology
- Adiponectin/genetics
- Disease Models, Animal
- Interleukin-6/metabolism
- Mice, Inbred C57BL
- Hydrogen Peroxide/metabolism
- Receptors, Adiponectin/genetics
- Receptors, Adiponectin/metabolism
- Mice, Inbred DBA
- Muscle, Skeletal/metabolism
- Diaphragm/metabolism
- Fibrosis
- Inflammation/metabolism
- Disease Progression
- Atrophy/metabolism
- Atrophy/pathology
Collapse
Affiliation(s)
- Catherine A Bellissimo
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Shivam Gandhi
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Laura N Castellani
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Mayoorey Murugathasan
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Luca J Delfinis
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Arshdeep Thuhan
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Madison C Garibotti
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Yeji Seo
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Irena A Rebalka
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Henry H Hsu
- Allysta Pharmaceuticals Inc, Bellevue, Washington, United States
| | - Gary Sweeney
- Department of Biology, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Thomas J Hawke
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Ali A Abdul-Sater
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Christopher G R Perry
- School of Kinesiology & Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| |
Collapse
|
5
|
Kramer PA, Coen PM, Cawthon PM, Distefano G, Cummings SR, Goodpaster BH, Hepple RT, Kritchevsky SB, Shankland EG, Marcinek DJ, Toledo FGS, Duchowny KA, Ramos SV, Harrison S, Newman AB, Molina AJA. Skeletal Muscle Energetics Explain the Sex Disparity in Mobility Impairment in the Study of Muscle, Mobility and Aging. J Gerontol A Biol Sci Med Sci 2024; 79:glad283. [PMID: 38150179 PMCID: PMC10960628 DOI: 10.1093/gerona/glad283] [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: 08/11/2023] [Indexed: 12/28/2023] Open
Abstract
The age-related decline in muscle mitochondrial energetics contributes to the loss of mobility in older adults. Women experience a higher prevalence of mobility impairment compared to men, but it is unknown whether sex-specific differences in muscle energetics underlie this disparity. In the Study of Muscle, Mobility and Aging (SOMMA), muscle energetics were characterized using in vivo phosphorus-31 magnetic resonance spectroscopy and high-resolution respirometry of vastus lateralis biopsies in 773 participants (56.4% women, age 70-94 years). A Short Physical Performance Battery (SPPB) score ≤8 was used to define lower-extremity mobility impairment. Muscle mitochondrial energetics were lower in women compared to men (eg, Maximal Complex I&II OXPHOS: Women = 55.06 ± 15.95; Men = 65.80 ± 19.74; p < .001) and in individuals with mobility impairment compared to those without (eg, Maximal Complex I&II OXPHOS in women: SPPB ≥ 9 = 56.59 ± 16.22; SPPB ≤ 8 = 47.37 ± 11.85; p < .001). Muscle energetics were negatively associated with age only in men (eg, Maximal ETS capacity: R = -0.15, p = .02; age/sex interaction, p = .04), resulting in muscle energetics measures that were significantly lower in women than men in the 70-79 age group but not the 80+ age group. Similarly, the odds of mobility impairment were greater in women than men only in the 70-79 age group (70-79 age group, odds ratio [OR]age-adjusted = 1.78, 95% confidence interval [CI] = 1.03, 3.08, p = .038; 80+ age group, ORage-adjusted = 1.05, 95% CI = 0.52, 2.15, p = .89). Accounting for muscle energetics attenuated up to 75% of the greater odds of mobility impairment in women. Women had lower muscle mitochondrial energetics compared to men, which largely explain their greater odds of lower-extremity mobility impairment.
Collapse
Affiliation(s)
- Philip A Kramer
- Department of Internal Medicine-Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Paul M Coen
- AdventHealth, Translational Research Institute, Orlando, Florida, USA
| | - Peggy M Cawthon
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, USA
- San Francisco Coordinating Center, California Pacific Medical Center Research Institute, San Francisco, California, USA
| | | | - Steven R Cummings
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, USA
- San Francisco Coordinating Center, California Pacific Medical Center Research Institute, San Francisco, California, USA
| | - Bret H Goodpaster
- AdventHealth, Translational Research Institute, Orlando, Florida, USA
| | - Russell T Hepple
- Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
| | - Stephen B Kritchevsky
- Department of Internal Medicine-Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Eric G Shankland
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | - David J Marcinek
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | - Frederico G S Toledo
- Department of Medicine-Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Kate A Duchowny
- Institute for Social Research, University of Michigan, Ann Arbor, Michigan, USA
| | - Sofhia V Ramos
- AdventHealth, Translational Research Institute, Orlando, Florida, USA
| | - Stephanie Harrison
- San Francisco Coordinating Center, California Pacific Medical Center Research Institute, San Francisco, California, USA
| | - Anne B Newman
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anthony J A Molina
- Department of Medicine-Division of Geriatrics, Gerontology, and Palliative Care, University of California San Diego School of Medicine, La Jolla, California, USA
| |
Collapse
|
6
|
Coulson SZ, Duffy BM, Staples JF. Mitochondrial techniques for physiologists. Comp Biochem Physiol B Biochem Mol Biol 2024; 271:110947. [PMID: 38278207 DOI: 10.1016/j.cbpb.2024.110947] [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: 11/02/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 01/28/2024]
Abstract
Mitochondria serve several important roles in maintaining cellular homeostasis, including adenosine triphosphate (ATP) synthesis, apoptotic signalling, and regulation of both reactive oxygen species (ROS) and calcium. Therefore, mitochondrial studies may reveal insights into metabolism at higher levels of physiological organization. The apparent complexity of mitochondrial function may be daunting to researchers new to mitochondrial physiology. This review is aimed, therefore, at such researchers to provide a brief, yet approachable overview of common techniques used to assess mitochondrial function. Here we discuss the use of high-resolution respirometry in mitochondrial experiments and common analytical platforms used for this technique. Next, we compare the use of common mitochondrial preparation techniques, including adherent cells, tissue homogenate, permeabilized fibers and isolated mitochondria. Finally, we outline additional techniques that can be used in tandem with high-resolution respirometry to assess additional aspects of mitochondrial metabolism, including ATP synthesis, calcium uptake, membrane potential and reactive oxygen species emission. We also include limitations to each of these techniques and outline recommendations for experimental design and interpretation. With a general understanding of methodologies commonly used to study mitochondrial physiology, experimenters may begin contributing to our understanding of this organelle, and how it affects other physiological phenotypes.
Collapse
Affiliation(s)
- Soren Z Coulson
- Department of Biology, University of Western Ontario, 1151 Richmond Street, London, Ontario, Canada.
| | - Brynne M Duffy
- Department of Biology, University of Western Ontario, 1151 Richmond Street, London, Ontario, Canada. https://twitter.com/BrynneDuffy
| | - James F Staples
- Department of Biology, University of Western Ontario, 1151 Richmond Street, London, Ontario, Canada
| |
Collapse
|
7
|
Ciccone C, Kante F, Folkow LP, Hazlerigg DG, West AC, Wood SH. Circadian coupling of mitochondria in a deep-diving mammal. J Exp Biol 2024; 227:jeb246990. [PMID: 38495024 PMCID: PMC11058691 DOI: 10.1242/jeb.246990] [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: 11/06/2023] [Accepted: 03/11/2024] [Indexed: 03/19/2024]
Abstract
Regulation of mitochondrial oxidative phosphorylation is essential to match energy supply to changing cellular energy demands, and to cope with periods of hypoxia. Recent work implicates the circadian molecular clock in control of mitochondrial function and hypoxia sensing. Because diving mammals experience intermittent episodes of severe hypoxia, with diel patterning in dive depth and duration, it is interesting to consider circadian-mitochondrial interaction in this group. Here, we demonstrate that the hooded seal (Cystophora cristata), a deep-diving Arctic pinniped, shows strong daily patterning of diving behaviour in the wild. Cultures of hooded seal skin fibroblasts exhibit robust circadian oscillation of the core clock genes per2 and arntl. In liver tissue collected from captive hooded seals, expression of arntl was some 4-fold higher in the middle of the night than in the middle of the day. To explore the clock-mitochondria relationship, we measured the mitochondrial oxygen consumption in synchronized hooded seal skin fibroblasts and found a circadian variation in mitochondrial activity, with higher coupling efficiency of complex I coinciding with the trough of arntl expression. These results open the way for further studies of circadian-hypoxia interactions in pinnipeds during diving.
Collapse
Affiliation(s)
- Chiara Ciccone
- Arctic Seasonal Timekeeping Initiative (ASTI), Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø NO-9037, Norway
| | - Fayiri Kante
- Arctic Seasonal Timekeeping Initiative (ASTI), Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø NO-9037, Norway
| | - Lars P. Folkow
- Arctic Seasonal Timekeeping Initiative (ASTI), Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø NO-9037, Norway
| | - David G. Hazlerigg
- Arctic Seasonal Timekeeping Initiative (ASTI), Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø NO-9037, Norway
| | - Alexander C. West
- Arctic Seasonal Timekeeping Initiative (ASTI), Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø NO-9037, Norway
| | - Shona H. Wood
- Arctic Seasonal Timekeeping Initiative (ASTI), Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø NO-9037, Norway
| |
Collapse
|
8
|
Hammoud S, Ivanova A, Osaki Y, Funk S, Yang H, Viquez O, Delgado R, Lu D, Phillips Mignemi M, Tonello J, Colon S, Lantier L, Wasserman DH, Humphreys BD, Koenitzer J, Kern J, de Caestecker M, Finkel T, Fogo A, Messias N, Lodhi IJ, Gewin LS. Tubular CPT1A deletion minimally affects aging and chronic kidney injury. JCI Insight 2024; 9:e171961. [PMID: 38516886 PMCID: PMC11063933 DOI: 10.1172/jci.insight.171961] [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: 05/02/2023] [Accepted: 02/14/2024] [Indexed: 03/23/2024] Open
Abstract
Kidney tubules use fatty acid oxidation (FAO) to support their high energetic requirements. Carnitine palmitoyltransferase 1A (CPT1A) is the rate-limiting enzyme for FAO, and it is necessary to transport long-chain fatty acids into mitochondria. To define the role of tubular CPT1A in aging and injury, we generated mice with tubule-specific deletion of Cpt1a (Cpt1aCKO mice), and the mice were either aged for 2 years or injured by aristolochic acid or unilateral ureteral obstruction. Surprisingly, Cpt1aCKO mice had no significant differences in kidney function or fibrosis compared with wild-type mice after aging or chronic injury. Primary tubule cells from aged Cpt1aCKO mice had a modest decrease in palmitate oxidation but retained the ability to metabolize long-chain fatty acids. Very-long-chain fatty acids, exclusively oxidized by peroxisomes, were reduced in kidneys lacking tubular CPT1A, consistent with increased peroxisomal activity. Single-nuclear RNA-Seq showed significantly increased expression of peroxisomal FAO enzymes in proximal tubules of mice lacking tubular CPT1A. These data suggest that peroxisomal FAO may compensate in the absence of CPT1A, and future genetic studies are needed to confirm the role of peroxisomal β-oxidation when mitochondrial FAO is impaired.
Collapse
Affiliation(s)
- Safaa Hammoud
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Alla Ivanova
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Yosuke Osaki
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Steven Funk
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Haichun Yang
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Olga Viquez
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Rachel Delgado
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Dongliang Lu
- Division of Endocrinology, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | | | - Jane Tonello
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Selene Colon
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Louise Lantier
- Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - David H. Wasserman
- Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Benjamin D. Humphreys
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Jeffrey Koenitzer
- Division of Pulmonary Critical Care Medicine, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Justin Kern
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | | | - Toren Finkel
- Aging Institute, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Agnes Fogo
- Division of Nephrology and Hypertension, Department of Medicine, and
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Nidia Messias
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Irfan J. Lodhi
- Division of Endocrinology, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Leslie S. Gewin
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
- Division of Nephrology and Hypertension, Department of Medicine, and
- Department of Medicine, Veterans Affairs Hospital, St. Louis, Missouri, USA
| |
Collapse
|
9
|
Cardaci TD, VanderVeen BN, Bullard BM, McDonald SJ, Unger CA, Enos RT, Fan D, Velázquez KT, Frizzell N, Spangenburg EE, Murphy EA. Obesity worsens mitochondrial quality control and does not protect against skeletal muscle wasting in murine cancer cachexia. J Cachexia Sarcopenia Muscle 2024; 15:124-137. [PMID: 38062911 PMCID: PMC10834333 DOI: 10.1002/jcsm.13391] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 09/15/2023] [Accepted: 11/02/2023] [Indexed: 01/12/2024] Open
Abstract
BACKGROUND More than 650 million people are obese (BMI > 30) worldwide, which increases their risk for several metabolic diseases and cancer. While cachexia and obesity are at opposite ends of the weight spectrum, leading many to suggest a protective effect of obesity against cachexia, mechanistic support for obesity's benefit is lacking. Given that obesity and cachexia are both accompanied by metabolic dysregulation, we sought to investigate the impact of obesity on skeletal muscle mass loss and mitochondrial dysfunction in murine cancer cachexia. METHODS Male C57BL/6 mice were given a purified high fat or standard diet for 16 weeks before being implanted with 106 Lewis lung carcinoma (LLC) cells. Mice were monitored for 25 days, and hindlimb muscles were collected for cachexia indices and mitochondrial assessment via western blotting, high-resolution respirometry and transmission electron microscopy (TEM). RESULTS Obese LLC mice experienced significant tumour-free body weight loss similar to lean (-12.8% vs. -11.8%, P = 0.0001) but had reduced survival (33.3% vs. 6.67%, χ2 = 10.04, P = 0.0182). Obese LLC mice had reduced muscle weights (-24%, P < 0.0354) and mCSA (-16%, P = 0.0004) with similar activation of muscle p65 (P = 0.0337), and p38 (P = 0.0008). ADP-dependent coupled respiration was reduced in both Obese and Obese LLC muscle (-30%, P = 0.0072) consistent with reductions in volitional cage activity (-39%, P < 0.0001) and grip strength (-41%, P < 0.0001). TEM revealed stepwise reductions in intermyofibrillar and subsarcolemmal mitochondrial size with Obese (IMF: -37%, P = 0.0009; SS: -21%, P = 0.0101) and LLC (IMF: -40%, P = 0.0019; SS: -27%, P = 0.0383) mice. Obese LLC mice had increased pAMPK (T172; P = 0.0103) and reduced FIS1 (P = 0.0029) and DRP1 (P < 0.0001) mitochondrial fission proteins, which were each unchanged in Lean LLC. Further, mitochondrial TEM analysis revealed that Obese LLC mice had an accumulation of damaged and dysfunctional mitochondria (IMF: 357%, P = 0.0395; SS: 138%, P = 0.0174) in concert with an accumulation of p62 (P = 0.0328) suggesting impaired autophagy and clearance of damaged mitochondria. Moreover, we observed increases in electron lucent vacuoles only in Obese LLC muscle (IMF: 421%, P = 0.0260; SS: 392%, P = 0.0192), further supporting an accumulation of damaged materials that cannot be properly cleared in the obese cachectic muscle. CONCLUSIONS Taken together, these results demonstrate that obesity is not protective against cachexia and suggest exacerbated impairments to mitochondrial function and quality control with a particular disruption in the removal of damaged mitochondria. Our findings highlight the need for consideration of the severity of obesity and pre-existing metabolic conditions when determining the impact of weight status on cancer-induced cachexia and functional mitochondrial deficits.
Collapse
Affiliation(s)
- Thomas D Cardaci
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Brandon N VanderVeen
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Brooke M Bullard
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Sierra J McDonald
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Christian A Unger
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Reilly T Enos
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Daping Fan
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Kandy T Velázquez
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Norma Frizzell
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Espen E Spangenburg
- Department of Physiology, East Carolina University, Greenville, North Carolina, USA
- Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - E Angela Murphy
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| |
Collapse
|
10
|
Zunica ERM, Heintz EC, Dantas WS, Hebert RC, Tanksley M, Beyl RA, Mader EC, Kirwan JP, Axelrod CL, Singh P. Effects of metformin on glucose metabolism and mitochondrial function in patients with obstructive sleep apnea: A pilot randomized trial. Physiol Rep 2024; 12:e15948. [PMID: 38346816 PMCID: PMC10861357 DOI: 10.14814/phy2.15948] [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: 10/24/2023] [Revised: 01/25/2024] [Accepted: 01/30/2024] [Indexed: 02/15/2024] Open
Abstract
Obstructive sleep apnea (OSA) is associated with increased risk for diabetes, and standard treatment with positive airway pressure (PAP) device shows inconsistent effects on glucose metabolism. Metformin is known to treat and prevent diabetes, but its effects on skeletal muscle mitochondrial function are not completely understood. Here, we evaluate the effects of metformin on glucose metabolism and skeletal muscle mitochondrial function in patients with OSA. Sixteen adults with obesity (50.9 ± 6.7 years, BMI: 36.5 ± 2.9 kg/m2 ) and moderate-to-severe OSA were provided with PAP treatment and randomized to 3 months of placebo (n = 8) or metformin (n = 8) treatment in a double-blind parallel-group design. Whole body glucose metabolism was determined by oral glucose tolerance test. A skeletal muscle biopsy was obtained to evaluate mitochondrial respiratory capacity and expression of proteins related to mitochondrial dynamics and energy metabolism. Whole body insulin-sensitivity (Matsuda index) did not change in metformin or placebo treated groups. However, metformin treatment prevented increases in insulin release relative to placebo during follow-up. Insulin area under the curve (AUC) and insulin to glucose AUC ratio increased in placebo but remained unchanged with metformin. Furthermore, metformin treatment improved skeletal muscle mitochondrial respiratory capacity and dynamics relative to placebo. Metformin treatment prevented the decline in whole body glucose homeostasis and skeletal muscle mitochondrial function in patients with moderate to severe OSA. Patients with OSA may benefit from the addition of metformin to prevent diabetes.
Collapse
Affiliation(s)
- Elizabeth R. M. Zunica
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLouisianaUSA
| | - Elizabeth C. Heintz
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLouisianaUSA
| | - Wagner S. Dantas
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLouisianaUSA
| | - R. Caitlin Hebert
- Translational Physiology LaboratoryPennington Biomedical Research CenterBaton RougeLouisianaUSA
| | - MaKayla Tanksley
- Sleep and Cardiometabolic Health LaboratoryPennington Biomedical Research CenterBaton RougeLouisianaUSA
| | - Robbie A. Beyl
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLouisianaUSA
| | - Edward C. Mader
- Louisiana State University Health Science CenterNew OrleansLouisianaUSA
| | - John P. Kirwan
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLouisianaUSA
| | - Christopher L. Axelrod
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLouisianaUSA
| | - Prachi Singh
- Sleep and Cardiometabolic Health LaboratoryPennington Biomedical Research CenterBaton RougeLouisianaUSA
| |
Collapse
|
11
|
Brisendine MH, Nichenko AS, Bandara AB, Willoughby OS, Amiri N, Weingrad Z, Specht KS, Bond JM, Addington A, Jones RG, Murach KA, Poelzing S, Craige SM, Grange RW, Drake JC. Neuromuscular Dysfunction Precedes Cognitive Impairment in a Mouse Model of Alzheimer's Disease. FUNCTION 2023; 5:zqad066. [PMID: 38111538 PMCID: PMC10727840 DOI: 10.1093/function/zqad066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/17/2023] [Accepted: 11/26/2023] [Indexed: 12/20/2023] Open
Abstract
Alzheimer's disease (AD) develops along a continuum that spans years prior to diagnosis. Decreased muscle function and mitochondrial respiration occur years earlier in those that develop AD; however, it is unknown what causes these peripheral phenotypes in a disease of the brain. Exercise promotes muscle, mitochondria, and cognitive health and is proposed to be a potential therapeutic for AD, but no study has investigated how skeletal muscle adapts to exercise training in an AD-like context. Utilizing 5xFAD mice, an AD model that develops ad-like pathology and cognitive impairments around 6 mo of age, we examined in vivo neuromuscular function and exercise adapations (mitochondrial respiration and RNA sequencing) before the manifestation of overt cognitive impairment. We found 5xFAD mice develop neuromuscular dysfunction beginning as early as 4 mo of age, characterized by impaired nerve-stimulated muscle torque production and compound nerve action potential of the sciatic nerve. Furthermore, skeletal muscle in 5xFAD mice had altered, sex-dependent, adaptive responses (mitochondrial respiration and gene expression) to exercise training in the absence of overt cognitive impairment. Changes in peripheral systems, specifically neural communication to skeletal muscle, may be harbingers for AD and have implications for lifestyle interventions, like exercise, in AD.
Collapse
Affiliation(s)
- Matthew H Brisendine
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061, USA
| | - Anna S Nichenko
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061, USA
| | - Aloka B Bandara
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061, USA
| | - Orion S Willoughby
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061, USA
| | - Niloufar Amiri
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061, USA
| | - Zach Weingrad
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Kalyn S Specht
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061, USA
| | - Jacob M Bond
- Translational Biology, Medicine, and Health Program, Virginia Tech, Roanoke, VA 24016, USA
| | - Adele Addington
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061, USA
| | - Ronald G Jones
- Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, AR 72701, USA
| | - Kevin A Murach
- Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, AR 72701, USA
| | - Steven Poelzing
- Translational Biology, Medicine, and Health Program, Virginia Tech, Roanoke, VA 24016, USA
| | - Siobhan M Craige
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061, USA
- Translational Biology, Medicine, and Health Program, Virginia Tech, Roanoke, VA 24016, USA
| | - Robert W Grange
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061, USA
| | - Joshua C Drake
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061, USA
- Translational Biology, Medicine, and Health Program, Virginia Tech, Roanoke, VA 24016, USA
| |
Collapse
|
12
|
Kramer PA, Coen PM, Cawthon PM, Distefano G, Cummings SR, Goodpaster BH, Hepple RT, Kritchevsky SB, Shankland EG, Marcinek DJ, Toledo FGS, Duchowny KA, Ramos SV, Harrison S, Newman AB, Molina AJA. Skeletal muscle energetics explain the sex disparity in mobility impairment in the Study of Muscle, Mobility and Aging (SOMMA). MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.11.08.23298271. [PMID: 37987007 PMCID: PMC10659490 DOI: 10.1101/2023.11.08.23298271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
The age-related decline in muscle mitochondrial energetics contributes to the loss of mobility in older adults. Women experience a higher prevalence of mobility impairment compared to men, but it is unknown whether sex-specific differences in muscle energetics underlie this disparity. In the Study of Muscle, Mobility and Aging (SOMMA), muscle energetics were characterized using in vivo phosphorus-31 magnetic resonance spectroscopy and high-resolution respirometry of vastus lateralis biopsies in 773 participants (56.4% women, age 70-94 years). A Short Physical Performance Battery score ≤ 8 was used to define lower-extremity mobility impairment. Muscle mitochondrial energetics were lower in women compared to men (e.g. Maximal Complex I&II OXPHOS: Women=55.06 +/- 15.95; Men=65.80 +/- 19.74; p<0.001) and in individuals with mobility impairment compared to those without (e.g., Maximal Complex I&II OXPHOS in women: SPPB≥9=56.59 +/- 16.22; SPPB≤8=47.37 +/- 11.85; p<0.001). Muscle energetics were negatively associated with age only in men (e.g., Maximal ETS capacity: R=-0.15, p=0.02; age/sex interaction, p=0.04), resulting in muscle energetics measures that were significantly lower in women than men in the 70-79 age group but not the 80+ age group. Similarly, the odds of mobility impairment were greater in women than men only in the 70-79 age group (70-79 age group, OR age-adjusted =1.78, 95% CI=1.03, 3.08, p=0.038; 80+ age group, OR age-adjusted =1.05, 95% CI=0.52, 2.15, p=0.89). Accounting for muscle energetics attenuated up to 75% of the greater odds of mobility impairment in women. Women had lower muscle mitochondrial energetics compared to men, which largely explain their greater odds of lower-extremity mobility impairment.
Collapse
|
13
|
Mau T, Lui LY, Distefano G, Kramer PA, Ramos SV, Toledo FGS, Santanasto AJ, Shankland EG, Marcinek DJ, Jurczak MJ, Sipula I, Bello FM, Duchowny KA, Molina AJA, Sparks LM, Goodpaster BH, Hepple RT, Kritchevsky SB, Newman AB, Cawthon PM, Cummings SR, Coen PM. Mitochondrial Energetics in Skeletal Muscle Are Associated With Leg Power and Cardiorespiratory Fitness in the Study of Muscle, Mobility and Aging. J Gerontol A Biol Sci Med Sci 2023; 78:1367-1375. [PMID: 36462195 PMCID: PMC10395564 DOI: 10.1093/gerona/glac238] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Mitochondrial energetics are an important property of aging muscle, as generation of energy is pivotal to the execution of muscle contraction. However, its association with functional outcomes, including leg power and cardiorespiratory fitness, is largely understudied. METHODS In the Study of Muscle, Mobility, and Aging, we collected vastus lateralis biopsies from older adults (n = 879, 70-94 years, 59.2% women). Maximal State 3 respiration (Max OXPHOS) was assessed in permeabilized fiber bundles by high-resolution respirometry. Capacity for maximal adenosine triphosphate production (ATPmax) was measured in vivo by 31P magnetic resonance spectroscopy. Leg extension power was measured with a Keiser press system, and VO2 peak was determined using a standardized cardiopulmonary exercise test. Gender-stratified multivariate linear regression models were adjusted for age, race, technician/site, adiposity, and physical activity with beta coefficients expressed per 1-SD increment in the independent variable. RESULTS Max OXPHOS was associated with leg power for both women (β = 0.12 Watts/kg, p < .001) and men (β = 0.11 Watts/kg, p < .050). ATPmax was associated with leg power for men (β = 0.09 Watts/kg, p < .05) but was not significant for women (β = 0.03 Watts/kg, p = .11). Max OXPHOS and ATPmax were associated with VO2 peak in women and men (Max OXPHOS, β women = 1.03 mL/kg/min, β men = 1.32 mL/kg/min; ATPmax β women = 0.87 mL/kg/min, β men = 1.50 mL/kg/min; all p < .001). CONCLUSIONS Higher muscle mitochondrial energetics measures were associated with both better cardiorespiratory fitness and greater leg power in older adults. Muscle mitochondrial energetics explained a greater degree of variance in VO2 peak compared to leg power.
Collapse
Affiliation(s)
- Theresa Mau
- San Francisco Coordinating Center, California Pacific Medical Center Research Institute, San Francisco, California, USA
- Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA
| | - Li-Yung Lui
- San Francisco Coordinating Center, California Pacific Medical Center Research Institute, San Francisco, California, USA
- Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA
| | | | - Philip A Kramer
- Department of Internal Medicine-Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Sofhia V Ramos
- AdventHealth, Translational Research Institute, Orlando, Florida, USA
| | - Frederico G S Toledo
- Department of Medicine-Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Adam J Santanasto
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Eric G Shankland
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | - David J Marcinek
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | - Michael J Jurczak
- Department of Medicine-Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Ian Sipula
- Department of Medicine-Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Fiona M Bello
- Department of Medicine-Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Kate A Duchowny
- Social Environment and Health, Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, Michigan, USA
| | - Anthony J A Molina
- Department of Internal Medicine-Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
- Department of Medicine-Division of Geriatrics, Gerontology, and Palliative Care, University of California San Diego School of Medicine, La Jolla, California, USA
| | - Lauren M Sparks
- AdventHealth, Translational Research Institute, Orlando, Florida, USA
| | - Bret H Goodpaster
- AdventHealth, Translational Research Institute, Orlando, Florida, USA
| | - Russell T Hepple
- Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
| | - Stephen B Kritchevsky
- Department of Internal Medicine-Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Anne B Newman
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Peggy M Cawthon
- San Francisco Coordinating Center, California Pacific Medical Center Research Institute, San Francisco, California, USA
- Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA
| | - Steven R Cummings
- San Francisco Coordinating Center, California Pacific Medical Center Research Institute, San Francisco, California, USA
- Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA
| | - Paul M Coen
- AdventHealth, Translational Research Institute, Orlando, Florida, USA
| |
Collapse
|
14
|
Bassiouni W, Valencia R, Mahmud Z, Seubert JM, Schulz R. Matrix metalloproteinase-2 proteolyzes mitofusin-2 and impairs mitochondrial function during myocardial ischemia-reperfusion injury. Basic Res Cardiol 2023; 118:29. [PMID: 37495895 DOI: 10.1007/s00395-023-00999-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 07/12/2023] [Accepted: 07/13/2023] [Indexed: 07/28/2023]
Abstract
During myocardial ischemia and reperfusion (IR) injury matrix metalloproteinase-2 (MMP-2) is rapidly activated in response to oxidative stress. MMP-2 is a multifunctional protease that cleaves both extracellular and intracellular proteins. Oxidative stress also impairs mitochondrial function which is regulated by different proteins, including mitofusin-2 (Mfn-2), which is lost in IR injury. Oxidative stress and mitochondrial dysfunction trigger the NLRP3 inflammasome and the innate immune response which invokes the de novo expression of an N-terminal truncated isoform of MMP-2 (NTT-MMP-2) at or near mitochondria. We hypothesized that MMP-2 proteolyzes Mfn-2 during myocardial IR injury, impairing mitochondrial function and enhancing the inflammasome response. Isolated hearts from mice subjected to IR injury (30 min ischemia/40 min reperfusion) showed a significant reduction in left ventricular developed pressure (LVDP) compared to aerobically perfused hearts. IR injury increased MMP-2 activity as observed by gelatin zymography and increased degradation of troponin I, an intracellular MMP-2 target. MMP-2 preferring inhibitors, ARP-100 or ONO-4817, improved post-ischemic recovery of LVDP compared to vehicle perfused IR hearts. In muscle fibers isolated from IR hearts the rates of mitochondrial oxygen consumption and ATP production were impaired compared to those from aerobic hearts, whereas ARP-100 or ONO-4817 attenuated these reductions. IR hearts showed higher levels of NLRP3, cleaved caspase-1 and interleukin-1β in the cytosolic fraction, while the mitochondria-enriched fraction showed reduced levels of Mfn-2, compared to aerobic hearts. ARP-100 or ONO-4817 attenuated these changes. Co-immunoprecipitation showed that MMP-2 is associated with Mfn-2 in aerobic and IR hearts. ARP-100 or ONO-4817 also reduced infarct size and cell death in hearts subjected to 45 min ischemia/120 min reperfusion. Following myocardial IR injury, impaired contractile function and mitochondrial respiration and elevated inflammasome response could be attributed, at least in part, to MMP-2 activation, which targets and cleaves mitochondrial Mfn-2. Inhibition of MMP-2 activity protects against cardiac contractile dysfunction in IR injury in part by preserving Mfn-2 and suppressing inflammation.
Collapse
Affiliation(s)
- Wesam Bassiouni
- Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Robert Valencia
- Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Zabed Mahmud
- Department of Pediatrics, Faculty of Medicine and Dentistry, 4-62 Heritage Medical Research Centre, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - John M Seubert
- Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Richard Schulz
- Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
- Department of Pediatrics, Faculty of Medicine and Dentistry, 4-62 Heritage Medical Research Centre, University of Alberta, Edmonton, AB, T6G 2S2, Canada.
| |
Collapse
|
15
|
Ritou E, Satta S, Petcherski A, Daskou M, Sharma M, Vasilopoulos H, Murakami E, Shirihai OS, Kelesidis T. Blood immune cells from people with HIV on antiviral regimens that contain tenofovir alafenamide (TAF) and tenofovir disoproxil fumarate (TDF) have differential metabolic signatures. Metabolism 2023; 141:155395. [PMID: 36842771 DOI: 10.1016/j.metabol.2022.155395] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 12/09/2022] [Accepted: 12/23/2022] [Indexed: 01/15/2023]
Abstract
BACKGROUND Mitochondria regulate immune and organ function. It is unknown whether higher intracellular drug levels observed in peripheral blood mononuclear cells (PBMCs) treated with tenofovir alafenamide (TAF) compared to tenofovir disoproxil fumarate (TDF) may alter mitochondrial function and energy production in immune cells in HIV(+) patients. METHODS Cellular bioenergetics were determined in PBMCs from HIV-1(-) participants exposed to TAF versus TDF in vitro, at a comparable concentration to a clinically relevant plasma exposure. A decrease in cellular oxygen consumption rate (OCR) at baseline (basal-OCR) and under cellular stress (max-OCR) may suggest mitochondrial dysfunction. We also assessed the in vivo impact of TAF vs TDF on OCR in PBMCs from 26 people with HIV (PWH) interchanged from TDF-based to TAF-based antiretroviral therapy (ART) over a 9-month period in the setting of an open label clinical trial. The Wilcoxon and Mann Whitney tests were used for comparison of continuous variables. RESULTS PBMCs from HIV-1(-) participants exposed in vitro to a concentration of 0.12-3.3 μM for TAF and TDF at 2 and 24 h, reduced basal and maximal OCR compared to vehicle control. Switch studies of antivirals (TAF vs TDF) within the same PWH showed that TAF-based ART was associated with reduced OCR compared to TDF-based ART in PBMCs. We observed that TAF-treated PBMCs selectively relied more on glucose/pyruvate supply rather than fatty acid to fuel their mitochondria. CONCLUSIONS Compared to TDF, TAF may alter bioenergetics in immune cells from PWH in vitro and in vivo. The clinical significance in terms of the differential impact caused by TAF versus TDF on mitochondrial function and energy production in immune cells, a regulator of immune function, requires further studied in HIV, preexposure prophylaxis and hepatitis B.
Collapse
Affiliation(s)
- Eleni Ritou
- Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Sandro Satta
- Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Anton Petcherski
- Department of Medicine, Division of Endocrinology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Maria Daskou
- Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Madhav Sharma
- Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Hariclea Vasilopoulos
- Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Eisuke Murakami
- Gilead Sciences, Inc., 333 Lakeside Drive, Foster City, CA 94404, USA
| | - Orian S Shirihai
- Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Theodoros Kelesidis
- Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
| |
Collapse
|
16
|
Schilloks MC, Giese IM, Hinrichs A, Korbonits L, Hauck SM, Wolf E, Deeg CA. Effects of GHR Deficiency and Juvenile Hypoglycemia on Immune Cells of a Porcine Model for Laron Syndrome. Biomolecules 2023; 13:biom13040597. [PMID: 37189345 DOI: 10.3390/biom13040597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/16/2023] [Accepted: 03/24/2023] [Indexed: 03/29/2023] Open
Abstract
Laron syndrome (LS) is a rare genetic disorder characterized by low levels of insulin-like growth factor 1 (IGF1) and high levels of growth hormone (GH) due to mutations in the growth hormone receptor gene (GHR). A GHR-knockout (GHR-KO) pig was developed as a model for LS, which displays many of the same features as humans with LS-like transient juvenile hypoglycemia. This study aimed to investigate the effects of impaired GHR signaling on immune functions and immunometabolism in GHR-KO pigs. GHR are located on various cell types of the immune system. Therefore, we investigated lymphocyte subsets, proliferative and respiratory capacity of peripheral blood mononuclear cells (PBMCs), proteome profiles of CD4− and CD4+ lymphocytes and IFN-α serum levels between wild-type (WT) controls and GHR-KO pigs, which revealed significant differences in the relative proportion of the CD4+CD8α− subpopulation and in IFN-α levels. We detected no significant difference in the respiratory capacity and the capacity for polyclonal stimulation in PBMCs between the two groups. But proteome analysis of CD4+ and CD4− lymphocyte populations revealed multiple significant protein abundance differences between GHR-KO and WT pigs, involving pathways related to amino acid metabolism, beta-oxidation of fatty acids, insulin secretion signaling, and oxidative phosphorylation. This study highlights the potential use of GHR-KO pigs as a model for studying the effects of impaired GHR signaling on immune functions.
Collapse
|
17
|
Decker ST, Alexandrou-Majaj N, Layec G. Effects of acute cigarette smoke concentrate exposure on mitochondrial energy transfer in fast- and slow-twitch skeletal muscle. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148973. [PMID: 36972770 DOI: 10.1016/j.bbabio.2023.148973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/26/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023]
Abstract
The mechanisms underlying cigarette smoke-induced mitochondrial dysfunction in skeletal muscle are still poorly understood. Accordingly, this study aimed to examine the effects of cigarette smoke on mitochondrial energy transfer in permeabilized muscle fibers from skeletal muscles with differing metabolic characteristics. The electron transport chain (ETC) capacity, ADP transport, and respiratory control by ADP were assessed in fast- and slow-twitch muscle fibers from C57BL/6 mice (n = 11) acutely exposed to cigarette smoke concentrate (CSC) using high-resolution respirometry. CSC decreased complex I-driven respiration in the white gastrocnemius (CONTROL:45.4 ± 11.2 pmolO2.s-1.mg-1 and CSC:27.5 ± 12.0 pmolO2.s-1.mg-1; p = 0.01) and soleus (CONTROL:63.0 ± 23.8 pmolO2.s-1.mg-1 and CSC:44.6 ± 11.1 pmolO2.s-1.mg-1; p = 0.04). In contrast, the effect of CSC on Complex II-linked respiration increased its relative contribution to muscle respiratory capacity in the white gastrocnemius muscle. The maximal respiratory activity of the ETC was significantly inhibited by CSC in both muscles. Furthermore, the respiration rate dependent on the ADP/ATP transport across the mitochondrial membrane was significantly impaired by CSC in the white gastrocnemius (CONTROL:-70 ± 18 %; CSC:-28 ± 10 %; p < 0.001), but not the soleus (CONTROL:47 ± 16 %; CSC:31 ± 7 %; p = 0.08). CSC also significantly impaired mitochondrial thermodynamic coupling in both muscles. Our findings underscore that acute CSC exposure directly inhibits oxidative phosphorylation in permeabilized muscle fibers. This effect was mediated by significant perturbations of the electron transfer in the respiratory complexes, especially at complex I, in both fast and slow twitch muscles. In contrast, CSC-induced inhibition of the exchange of ADP/ATP across the mitochondrial membrane was fiber-type specific, with a large effect on fast-twitch muscles.
Collapse
Affiliation(s)
- Stephen T Decker
- Department of Kinesiology, University of Massachusetts Amherst, USA
| | | | - Gwenael Layec
- Department of Kinesiology, University of Massachusetts Amherst, USA; Institute for Applied Life Science, University of Massachusetts Amherst, USA.
| |
Collapse
|
18
|
Crowder JJ, Zeng Z, Novak AN, Alves NJ, Linnemann AK. Stabilization protects islet integrity during respirometry in the Oroboros Oxygraph-2K analyzer. Islets 2022; 14:128-138. [PMID: 35331085 PMCID: PMC8959522 DOI: 10.1080/19382014.2022.2054251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Metabolic dysfunction of β-cells has been implicated as a contributor to diabetes pathogenesis, and efforts are ongoing to optimize analytical techniques that evaluate islet metabolism. High-resolution respirometry offers sensitive measurements of the respiratory effects of metabolic substrates and customizable manipulation of electron transport chain components, though the delicate nature of islets can pose challenges to conventional analyses. An affordable and reliable option for respirometry is the Oroboros Oxygraph-2 K system, which utilizes a stir bar to circulate reagents around cells. While this technique may be suitable for individual cells or mitochondria, the continual force exerted by the stir bar can have damaging effects on islet integrity. Herein, we demonstrate the protective benefits of a novel 3D-printed islet stabilization device and highlight the destructive effects of conventional Oxygraph analysis on islet integrity. Islet containment did not inhibit cellular responses to metabolic modulatory drugs, as indicated by robust fluctuations in oxygen consumption rates. The average size of wild-type mouse islets was significantly reduced following a standard Mito Stress Test within Oxygraph chambers, with a clear disruption in islet morphology and viability. Alternatively, containment of the islets within the interior chamber of the islet stabilization device yielded preservation of both islet morphology and increased cell viability/survival after respirometry analysis. Collectively, our study introduces a new and easily accessible tool to improve conventional Oxygraph respirometry of pancreatic islets by preserving natural islet structure and function throughout metabolic analysis.
Collapse
Affiliation(s)
- Justin J. Crowder
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ziqian Zeng
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Alissa N. Novak
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Nathan J. Alves
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
- Amelia K. Linnemann Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Amelia K. Linnemann
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
- Indiana Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA
- CONTACT Nathan J. Alves
| |
Collapse
|
19
|
Pilotto AM, Adami A, Mazzolari R, Brocca L, Crea E, Zuccarelli L, Pellegrino MA, Bottinelli R, Grassi B, Rossiter HB, Porcelli S. Near-infrared spectroscopy estimation of combined skeletal muscle oxidative capacity and O 2 diffusion capacity in humans. J Physiol 2022; 600:4153-4168. [PMID: 35930524 PMCID: PMC9481735 DOI: 10.1113/jp283267] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 07/27/2022] [Indexed: 01/05/2023] Open
Abstract
The final steps of the O2 cascade during exercise depend on the product of the microvascular-to-intramyocyteP O 2 ${P}_{{{\rm{O}}}_{\rm{2}}}$ difference and muscle O2 diffusing capacity (D m O 2 $D{{\rm{m}}}_{{{\rm{O}}}_2}$ ). Non-invasive methods to determineD m O 2 $D{{\rm{m}}}_{{{\rm{O}}}_2}$ in humans are currently unavailable. Muscle oxygen uptake (mV ̇ O 2 ${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ ) recovery rate constant (k), measured by near-infrared spectroscopy (NIRS) using intermittent arterial occlusions, is associated with muscle oxidative capacity in vivo. We reasoned that k would be limited byD m O 2 $D{{\rm{m}}}_{{{\rm{O}}}_2}$ when muscle oxygenation is low (kLOW ), and hypothesized that: (i) k in well oxygenated muscle (kHIGH ) is associated with maximal O2 flux in fibre bundles; and (ii) ∆k (kHIGH - kLOW ) is associated with capillary density (CD). Vastus lateralis k was measured in 12 participants using NIRS after moderate exercise. The timing and duration of arterial occlusions were manipulated to maintain tissue saturation index within a 10% range either below (LOW) or above (HIGH) half-maximal desaturation, assessed during sustained arterial occlusion. Maximal O2 flux in phosphorylating state was 37.7 ± 10.6 pmol s-1 mg-1 (∼5.8 ml min-1 100 g-1 ). CD ranged 348 to 586 mm-2 . kHIGH was greater than kLOW (3.15 ± 0.45 vs. 1.56 ± 0.79 min-1 , P < 0.001). Maximal O2 flux was correlated with kHIGH (r = 0.80, P = 0.002) but not kLOW (r = -0.10, P = 0.755). Δk ranged -0.26 to -2.55 min-1 , and correlated with CD (r = -0.68, P = 0.015). mV ̇ O 2 ${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ k reflects muscle oxidative capacity only in well oxygenated muscle. ∆k, the difference in k between well and poorly oxygenated muscle, was associated with CD, a mediator ofD m O 2 $D{{\rm{m}}}_{{{\rm{O}}}_2}$ . Assessment of muscle k and ∆k using NIRS provides a non-invasive window on muscle oxidative and O2 diffusing capacity. KEY POINTS: We determined post-exercise recovery kinetics of quadriceps muscle oxygen uptake (mV ̇ O 2 ${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ ) measured by near-infrared spectroscopy (NIRS) in humans under conditions of both non-limiting (HIGH) and limiting (LOW) O2 availability, for comparison with biopsy variables. The mV ̇ O 2 ${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ recovery rate constant in HIGH O2 availability was hypothesized to reflect muscle oxidative capacity (kHIGH ) and the difference in k between HIGH and LOW O2 availability (∆k) was hypothesized to reflect muscle O2 diffusing capacity. kHIGH was correlated with phosphorylating oxidative capacity of permeabilized muscle fibre bundles (r = 0.80). ∆k was negatively correlated with capillary density (r = -0.68) of biopsy samples. NIRS provides non-invasive means of assessing both muscle oxidative and oxygen diffusing capacity in vivo.
Collapse
Affiliation(s)
- Andrea M. Pilotto
- Department of MedicineUniversity of UdineUdineItaly
- Department of Molecular MedicineInstitute of PhysiologyUniversity of PaviaPaviaItaly
| | - Alessandra Adami
- Department of KinesiologyUniversity of Rhode IslandKingstonRIUSA
| | - Raffaele Mazzolari
- Department of Molecular MedicineInstitute of PhysiologyUniversity of PaviaPaviaItaly
- Department of Physical Education and SportUniversity of the Basque Country (UPV/EHU)Vitoria‐GasteizSpain
| | - Lorenza Brocca
- Department of Molecular MedicineInstitute of PhysiologyUniversity of PaviaPaviaItaly
| | - Emanuela Crea
- Department of Molecular MedicineInstitute of PhysiologyUniversity of PaviaPaviaItaly
| | | | - Maria A. Pellegrino
- Department of Molecular MedicineInstitute of PhysiologyUniversity of PaviaPaviaItaly
- Interdipartimental Centre for Biology and Sport MedicineUniversity of PaviaPaviaItaly
| | - Roberto Bottinelli
- Department of Molecular MedicineInstitute of PhysiologyUniversity of PaviaPaviaItaly
- Interdipartimental Centre for Biology and Sport MedicineUniversity of PaviaPaviaItaly
| | - Bruno Grassi
- Department of MedicineUniversity of UdineUdineItaly
| | - Harry B. Rossiter
- Division of Respiratory and Critical Care Physiology and MedicineThe Lundquist Institute for Biomedical Innovation at Harbor–UCLA Medical CenterTorranceCAUSA
| | - Simone Porcelli
- Department of Molecular MedicineInstitute of PhysiologyUniversity of PaviaPaviaItaly
- Institute of Biomedical TechnologiesNational Research CouncilMilanItaly
| |
Collapse
|
20
|
Avram VF, Merce AP, Hâncu IM, Bătrân AD, Kennedy G, Rosca MG, Muntean DM. Impairment of Mitochondrial Respiration in Metabolic Diseases: An Overview. Int J Mol Sci 2022; 23:ijms23168852. [PMID: 36012137 PMCID: PMC9408127 DOI: 10.3390/ijms23168852] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/05/2022] [Accepted: 08/06/2022] [Indexed: 11/16/2022] Open
Abstract
Mitochondrial dysfunction has emerged as a central pathomechanism in the setting of obesity and diabetes mellitus, linking these intertwined pathologies that share insulin resistance as a common denominator. High-resolution respirometry (HRR) is a state-of-the-art research method currently used to study mitochondrial respiration and its impairment in health and disease. Tissue samples, cells or isolated mitochondria are exposed to various substrate-uncoupler-inhibitor-titration protocols, which allows the measurement and calculation of several parameters of mitochondrial respiration. In this review, we discuss the alterations of mitochondrial bioenergetics in the main dysfunctional organs that contribute to the development of the obese and diabetic phenotypes in both animal models and human subjects. Herein we review data regarding the impairment of oxidative phosphorylation as integrated mitochondrial function assessed by means of HRR. We acknowledge the critical role of this method in determining the alterations in oxidative phosphorylation occurring in the early stages of metabolic pathologies. We conclude that there is a mutual two-way relationship between mitochondrial dysfunction and insulin insensitivity that characterizes these diseases.
Collapse
Affiliation(s)
- Vlad Florian Avram
- Department VII Internal Medicine—Diabetes, Nutrition and Metabolic Diseases, “Victor Babeș” University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041 Timișoara, Romania
- Center for Molecular Research in Nephrology and Vascular Disease, “Victor Babeș” University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041 Timișoara, Romania
| | - Adrian Petru Merce
- Doctoral School Medicine—Pharmacy, “Victor Babeș” University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041 Timișoara, Romania
- Center for Translational Research and Systems Medicine, “Victor Babeș” University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041 Timișoara, Romania
| | - Iasmina Maria Hâncu
- Doctoral School Medicine—Pharmacy, “Victor Babeș” University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041 Timișoara, Romania
- Center for Translational Research and Systems Medicine, “Victor Babeș” University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041 Timișoara, Romania
| | - Alina Doruța Bătrân
- Doctoral School Medicine—Pharmacy, “Victor Babeș” University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041 Timișoara, Romania
- Center for Translational Research and Systems Medicine, “Victor Babeș” University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041 Timișoara, Romania
| | - Gabrielle Kennedy
- Department of Foundational Sciences, Central Michigan University College of Medicine, Mount Pleasant, MI 48858, USA
| | - Mariana Georgeta Rosca
- Department of Foundational Sciences, Central Michigan University College of Medicine, Mount Pleasant, MI 48858, USA
- Correspondence: (M.G.R.); (D.M.M.)
| | - Danina Mirela Muntean
- Center for Translational Research and Systems Medicine, “Victor Babeș” University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041 Timișoara, Romania
- Department III Functional Sciences—Pathophysiology, “Victor Babeș” University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041 Timișoara, Romania
- Correspondence: (M.G.R.); (D.M.M.)
| |
Collapse
|
21
|
Divakaruni AS, Jastroch M. A practical guide for the analysis, standardization and interpretation of oxygen consumption measurements. Nat Metab 2022; 4:978-994. [PMID: 35971004 PMCID: PMC9618452 DOI: 10.1038/s42255-022-00619-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 06/17/2022] [Indexed: 12/14/2022]
Abstract
Measurement of oxygen consumption is a powerful and uniquely informative experimental technique. It can help identify mitochondrial mechanisms of action following pharmacologic and genetic interventions, and characterize energy metabolism in physiology and disease. The conceptual and practical benefits of respirometry have made it a frontline technique to understand how mitochondrial function can interface with-and in some cases control-cell physiology. Nonetheless, an appreciation of the complexity and challenges involved with such measurements is required to avoid common experimental and analytical pitfalls. Here we provide a practical guide to oxygen consumption measurements covering the selection of experimental models and instrumentation, as well as recommendations for the collection, interpretation and normalization of data. These guidelines are provided with the intention of aiding experimental design and enhancing the overall reputability, transparency and reliability of oxygen consumption measurements.
Collapse
Affiliation(s)
- Ajit S Divakaruni
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
| | - Martin Jastroch
- Department of Molecular Biosciences, The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, Stockholm, Sweden
| |
Collapse
|
22
|
Bellissimo CA, Garibotti MC, Perry CGR. Mitochondrial Stress Responses in Duchenne muscular dystrophy: Metabolic Dysfunction or Adaptive Reprogramming? Am J Physiol Cell Physiol 2022; 323:C718-C730. [PMID: 35816642 DOI: 10.1152/ajpcell.00249.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mitochondrial stress may be a secondary contributor to muscle weakness in inherited muscular dystrophies. Duchenne muscular dystrophy has received the majority of attention whereby most discoveries suggest mitochondrial ATP synthesis may be reduced. However, not all studies support this finding. Furthermore, some studies have reported increased mitochondrial reactive oxygen species and propensity for permeability transition pore formation as an inducer of apoptosis, although divergent findings have also been described. A closer examination of the literature suggests the degree and direction of mitochondrial stress responses may depend on the progression of the disease, the muscle type examined, the mouse model employed with regards to pre-clinical research, the precise metabolic pathways in consideration, and in some cases the in vitro technique used to assess a given mitochondrial bioenergetic function. One intent of this review is to provide careful considerations for future experimental designs to resolve the heterogeneous nature of mitochondrial stress during the progression of Duchenne muscular dystrophy. Such considerations have implications for other muscular dystrophies as well which are addressed briefly herein. A renewed perspective of the term 'mitochondrial dysfunction' is presented whereby stress responses might be re-explored in future investigations as direct contributors to myopathy vs an adaptive 'reprogramming' intended to maintain homeostasis in the face of disease stressors themselves. In so doing, the prospective development of mitochondrial enhancement therapies can be driven by advances in perspectives as much as experimental approaches when resolving the precise relationships between mitochondrial remodelling and muscle weakness in Duchenne and, indeed, other muscular dystrophies.
Collapse
Affiliation(s)
- Catherine A Bellissimo
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Madison C Garibotti
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Christopher G R Perry
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada
| |
Collapse
|
23
|
Effects of Different Types of Chronic Training on Bioenergetic Profile and Reactive Oxygen Species Production in LHCN-M2 Human Myoblast Cells. Int J Mol Sci 2022; 23:ijms23147491. [PMID: 35886840 PMCID: PMC9320149 DOI: 10.3390/ijms23147491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/29/2022] [Accepted: 07/04/2022] [Indexed: 11/17/2022] Open
Abstract
Human skeletal muscle contains three different types of fibers, each with a different metabolism. Exercise differently contributes to differentiation and metabolism in human myoblast cells. The aims of the present study were to investigate the effects of different types of chronic training on the human LHCN-M2 myoblast cell bioenergetic profile during differentiation in real time and on the ROS overproduction consequent to H2O2 injury. We demonstrated that exercise differently affects the myoblast bioenergetics: aerobic exercise induced the most efficient glycolytic and oxidative capacity and proton leak reduction compared to untrained or anaerobic trained sera-treated cells. Similarly, ROS overproduction after H2O2 stress was lower in cells treated with differently trained sera compared to untrained sera, indicating a cytoprotective effect of training on the reduction of oxidative stress, and thus the promotion of longevity. In conclusion, for the first time, this study has provided knowledge regarding the modifications induced by different types of chronic training on human myoblast cell bioenergetics during the differentiation process in real time, and on ROS overproduction due to stress, with positive implications in terms of longevity.
Collapse
|
24
|
Integrative metabolic flux analysis reveals an indispensable dimension of phenotypes. Curr Opin Biotechnol 2022; 75:102701. [DOI: 10.1016/j.copbio.2022.102701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 01/26/2022] [Accepted: 02/04/2022] [Indexed: 02/06/2023]
|
25
|
Stremming J, Chang EI, Knaub LA, Armstrong ML, Baker PR, Wesolowski SR, Reisdorph N, Reusch JEB, Brown LD. Lower citrate synthase activity, mitochondrial complex expression, and fewer oxidative myofibers characterize skeletal muscle from growth-restricted fetal sheep. Am J Physiol Regul Integr Comp Physiol 2022; 322:R228-R240. [PMID: 34907787 PMCID: PMC8858669 DOI: 10.1152/ajpregu.00222.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Skeletal muscle from the late gestation sheep fetus with intrauterine growth restriction (IUGR) has evidence of reduced oxidative metabolism. Using a sheep model of placental insufficiency and IUGR, we tested the hypothesis that by late gestation, IUGR fetal skeletal muscle has reduced capacity for oxidative phosphorylation because of intrinsic deficits in mitochondrial respiration. We measured mitochondrial respiration in permeabilized muscle fibers from biceps femoris (BF) and soleus (SOL) from control and IUGR fetal sheep. Using muscles including BF, SOL, tibialis anterior (TA), and flexor digitorum superficialis (FDS), we measured citrate synthase (CS) activity, mitochondrial complex subunit abundance, fiber type distribution, and gene expression of regulators of mitochondrial biosynthesis. Ex vivo mitochondrial respiration was similar in control and IUGR muscle. However, CS activity was lower in IUGR BF and TA, indicating lower mitochondrial content, and protein expression of individual mitochondrial complex subunits was lower in IUGR TA and BF in a muscle-specific pattern. IUGR TA, BF, and FDS also had lower expression of type I oxidative fibers. Fiber-type shifts that support glycolytic instead of oxidative metabolism may be advantageous for the IUGR fetus in a hypoxic and nutrient-deficient environment, whereas these adaptions may be maladaptive in postnatal life.
Collapse
Affiliation(s)
- Jane Stremming
- 1Department of Pediatrics, University of Colorado, Aurora, Colorado
| | - Eileen I. Chang
- 1Department of Pediatrics, University of Colorado, Aurora, Colorado
| | - Leslie A. Knaub
- 2Division of Endocrinology, University of Colorado, Aurora, Colorado,3Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, Colorado
| | | | - Peter R. Baker
- 1Department of Pediatrics, University of Colorado, Aurora, Colorado
| | | | | | - Jane E. B. Reusch
- 2Division of Endocrinology, University of Colorado, Aurora, Colorado,3Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, Colorado
| | - Laura D. Brown
- 1Department of Pediatrics, University of Colorado, Aurora, Colorado
| |
Collapse
|
26
|
Platelets in Fetal Growth Restriction: Role of Reactive Oxygen Species, Oxygen Metabolism, and Aggregation. Cells 2022; 11:cells11040724. [PMID: 35203373 PMCID: PMC8870240 DOI: 10.3390/cells11040724] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 02/15/2022] [Accepted: 02/17/2022] [Indexed: 12/27/2022] Open
Abstract
Fetal growth restriction (FGR) is mainly caused by failure of the uteroplacental unit. The exact pathogenesis remains unclear. The cause is thought to be related to abnormal platelet activation, which may result in microthrombus formation in the small vessels of the placenta. Reactive oxygen species (ROS) may initiate the pathological process of platelet activation. This study aimed to evaluate selected platelet parameters in pregnancy complicated by FGR and relate them to the severity of hemodynamic abnormalities. A total of 135 women (pregnant with FGR, with an uncomplicated pregnancy, and non-pregnant) were enrolled to study different platelet parameters: count (PLT), mean volume (MPV), ROS levels, intracellular oxygen level, oxygen consumption, and aggregation indices. No abnormalities in PLT and MPV were found in the FGR group, although it revealed increased ROS levels in platelets, lower platelet oxygen consumption, and intraplatelet deprivation. Aggregation parameters were similar as in uncomplicated pregnancy. No significant relationships were observed between hemodynamic abnormalities and the studied parameters. Platelets in pregnancies complicated by FGR may reveal an impaired oxidative metabolism, which may, in turn, lead to oxidative stress and, consequently, to an impaired platelet function. This study adds to the understanding of the role of platelets in the etiology of FGR.
Collapse
|
27
|
Kunz HE, Port JD, Kaufman KR, Jatoi A, Hart CR, Gries KJ, Lanza IR, Kumar R. Skeletal muscle mitochondrial dysfunction and muscle and whole body functional deficits in cancer patients with weight loss. J Appl Physiol (1985) 2022; 132:388-401. [PMID: 34941442 PMCID: PMC8791841 DOI: 10.1152/japplphysiol.00746.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Reductions in skeletal muscle mass and function are often reported in patients with cancer-associated weight loss and are associated with reduced quality of life, impaired treatment tolerance, and increased mortality. Although cellular changes, including altered mitochondrial function, have been reported in animals, such changes have been incompletely characterized in humans with cancer. Whole body and skeletal muscle physical function, skeletal muscle mitochondrial function, and whole body protein turnover were assessed in eight patients with cancer-associated weight loss (10.1 ± 4.2% body weight over 6-12 mo) and 19 age-, sex-, and body mass index (BMI)-matched healthy controls to characterize skeletal muscle changes at the whole body, muscle, and cellular level. Potential pathways involved in cancer-induced alterations in metabolism and mitochondrial function were explored by interrogating skeletal muscle and plasma metabolomes. Despite similar lean mass compared with control participants, patients with cancer exhibited reduced habitual physical activity (57% fewer daily steps), cardiorespiratory fitness [22% lower V̇o2peak (mL/kg/min)] and leg strength (35% lower isokinetic knee extensor strength), and greater leg neuromuscular fatigue (36% greater decline in knee extensor torque). Concomitant with these functional declines, patients with cancer had lower mitochondrial oxidative capacity [25% lower State 3 O2 flux (pmol/s/mg tissue)] and ATP production [23% lower State 3 ATP production (pmol/s/mg tissue)] and alterations in phospholipid metabolite profiles indicative of mitochondrial abnormalities. Whole body protein turnover was unchanged. These findings demonstrate mitochondrial abnormalities concomitant with whole body and skeletal muscle functional derangements associated with human cancer, supporting future work studying the role of mitochondria in the muscle deficits associated with cancer.NEW & NOTEWORTHY To our knowledge, this is the first study to suggest that skeletal muscle mitochondrial deficits are associated with cancer-associated weight loss in humans. Mitochondrial deficits were concurrent with reductions in whole body and skeletal muscle functional capacity. Whether mitochondrial deficits are causal or secondary to cancer-associated weight loss and functional deficits remains to be determined, but this study supports further exploration of mitochondria as a driver of cancer-associated losses in muscle mass and function.
Collapse
Affiliation(s)
- Hawley E. Kunz
- 1Endocrine Research Unit, Division of Endocrinology, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota
| | - John D. Port
- 2Division of Neuroradiology, Department of Radiology, Mayo Clinic, Rochester, Minnesota
| | - Kenton R. Kaufman
- 3Motion Analysis Laboratory, Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota
| | - Aminah Jatoi
- 4Department of Oncology, Mayo Clinic, Rochester, Minnesota
| | - Corey R. Hart
- 1Endocrine Research Unit, Division of Endocrinology, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota
| | - Kevin J. Gries
- 1Endocrine Research Unit, Division of Endocrinology, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota
| | - Ian R. Lanza
- 1Endocrine Research Unit, Division of Endocrinology, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota
| | - Rajiv Kumar
- 5Nephrology and Hypertension Research Unit, Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota,6Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota
| |
Collapse
|
28
|
Kuang J, Saner NJ, Botella J, Lee MJ, Granata C, Wang Z, Yan X, Li J, Genders AJ, Bishop DJ. Assessing mitochondrial respiration in permeabilized fibres and biomarkers for mitochondrial content in human skeletal muscle. Acta Physiol (Oxf) 2022; 234:e13772. [PMID: 34985815 DOI: 10.1111/apha.13772] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/16/2021] [Accepted: 01/01/2022] [Indexed: 12/16/2022]
Abstract
AIM Assessments of mitochondrial respiration and mitochondrial content are common in skeletal muscle research and exercise science. However, many sources of technical and biological variation render these analyses susceptible to error. This study aimed to better quantify the reliability of different experimental designs and/or techniques so as to assist researchers to obtain more reliable data. METHODS We examined the repeatability of maximal mitochondrial oxidative phosphorylation in permeabilized muscle fibres via high-resolution respirometry, and citrate synthase activity (a biomarker for mitochondrial content) in a microplate with spectrophotometery. RESULTS For mitochondrial respiration using permeabilized skeletal muscle fibres, the variability was reduced using three chambers and removing outliers compared to two chambers (CV reduced from 12.7% to 11.0%), and the minimal change that can be detected with 10 participants reduced from 17% to 13% according to modelling. For citrate synthase activity, the within-plate CV (3.5%) increased when the assay was repeated after 4 hours (CV = 10.2%) and 4 weeks (CV = 30.5%). The readings were correlated, but significantly different after 4 hours and 4 weeks. CONCLUSION This research provides evidence for important technical considerations when measuring mitochondrial respiration and content using citrate synthase activity as a biomarker. When assessing mitochondrial respiration in human skeletal muscle, the technical variability of high-resolution respirometry can be reduced by increasing technical repeats and excluding outliers, practices which are not currently common. When analysing citrate synthase activity, our results highlight the importance of analysing all samples from the same study at the same time.
Collapse
Affiliation(s)
- Jujiao Kuang
- Institute for Health and Sport (IHES) Victoria University Melbourne Victoria Australia
- Australia Institute for Musculoskeletal Sciences Melbourne Victoria Australia
| | - Nicholas J. Saner
- Institute for Health and Sport (IHES) Victoria University Melbourne Victoria Australia
- Department of Sports Cardiology Baker Heart and Diabetes Institute Melbourne Victoria Australia
| | - Javier Botella
- Institute for Health and Sport (IHES) Victoria University Melbourne Victoria Australia
| | - Matthew J.‐C. Lee
- Institute for Health and Sport (IHES) Victoria University Melbourne Victoria Australia
| | - Cesare Granata
- Institute for Health and Sport (IHES) Victoria University Melbourne Victoria Australia
- Department of Diabetes Central Clinical School Monash University Melbourne Victoria Australia
- Institute for Clinical Diabetology German Diabetes Center Leibniz Center for Diabetes Research Heinrich Heine University Düsseldorf Germany
| | - Zhenhuan Wang
- Institute for Health and Sport (IHES) Victoria University Melbourne Victoria Australia
- College of Physical Education Southwest University Chongqing China
| | - Xu Yan
- Institute for Health and Sport (IHES) Victoria University Melbourne Victoria Australia
- Australia Institute for Musculoskeletal Sciences Melbourne Victoria Australia
| | - Jia Li
- Institute for Health and Sport (IHES) Victoria University Melbourne Victoria Australia
- College of Physical Education Southwest University Chongqing China
| | - Amanda J. Genders
- Institute for Health and Sport (IHES) Victoria University Melbourne Victoria Australia
| | - David J. Bishop
- Institute for Health and Sport (IHES) Victoria University Melbourne Victoria Australia
| |
Collapse
|
29
|
Tsogtbaatar E, Minter-Dykhouse K, Saarinen A, Folmes CDL. Extracellular Flux Analysis of Mitochondrial Function in Pluripotent Stem Cells. Methods Mol Biol 2022; 2429:85-102. [PMID: 35507157 DOI: 10.1007/978-1-0716-1979-7_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Mitochondrial function and energy metabolism are increasingly recognized not only as regulators of pluripotent stem cell function and fate, but also as critical targets in disease pathogenesis and aging. Therefore across the downstream applications of pluripotent stem cells, including development and disease modeling, drug screening, and cell-based therapies, it is crucial to be able to measure mitochondrial function and metabolism in a high-throughput, real-time and label-free manner. Here we describe the application of Seahorse extracellular flux analysis to measure mitochondrial function in pluripotent stem cells and their derivatives. Specifically, we highlight two assays, the Mitochondrial Stress Test, which quantifies overall mitochondrial function including basal, maximal and ATP-couple oxygen consumption rates, and the Electron Transport Chain Complex Specific assay, that quantifies function of individual complexes within the electron transport chain.
Collapse
Affiliation(s)
- Enkhtuul Tsogtbaatar
- Stem Cell and Regenerative Metabolism Laboratory, Departments of Cardiovascular Medicine, Biochemistry and Molecular Biology, and Center for Regenerative Medicine, Mayo Clinic, Scottsdale, AZ, USA
| | - Katherine Minter-Dykhouse
- Stem Cell and Regenerative Metabolism Laboratory, Departments of Cardiovascular Medicine, Biochemistry and Molecular Biology, and Center for Regenerative Medicine, Mayo Clinic, Scottsdale, AZ, USA
| | - Alicia Saarinen
- Stem Cell and Regenerative Metabolism Laboratory, Departments of Cardiovascular Medicine, Biochemistry and Molecular Biology, and Center for Regenerative Medicine, Mayo Clinic, Scottsdale, AZ, USA
| | - Clifford D L Folmes
- Stem Cell and Regenerative Metabolism Laboratory, Departments of Cardiovascular Medicine, Biochemistry and Molecular Biology, and Center for Regenerative Medicine, Mayo Clinic, Scottsdale, AZ, USA.
| |
Collapse
|
30
|
Caldeira DDAF, de Oliveira DF, Cavalcanti-de-Albuquerque JP, Nascimento JHM, Zin WA, Maciel L. Isolation of Mitochondria From Fresh Mice Lung Tissue. Front Physiol 2021; 12:748261. [PMID: 34916953 PMCID: PMC8670177 DOI: 10.3389/fphys.2021.748261] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/29/2021] [Indexed: 11/13/2022] Open
Abstract
Direct analysis of isolated mitochondria enables a better understanding of lung dysfunction. Despite well-defined mitochondrial isolation protocols applicable to other tissues, such as the brain, kidney, heart, and liver, a robust and reproductive protocol has not yet been advanced for the lung. We describe a protocol for the isolation of mitochondria from lung tissue aiming for functional analyses of mitochondrial O2 consumption, transmembrane potential, reactive oxygen species (ROS) formation, ATP production, and swelling. We compared our protocol to that used for heart mitochondrial function that is well-established in the literature, and achieved similar results.
Collapse
Affiliation(s)
| | | | | | | | - Walter Araujo Zin
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Leonardo Maciel
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Professor Geraldo Cidade Campus, Federal University of Rio de Janeiro, Duque de Caxias, Brazil
| |
Collapse
|
31
|
Anoar S, Woodling NS, Niccoli T. Mitochondria Dysfunction in Frontotemporal Dementia/Amyotrophic Lateral Sclerosis: Lessons From Drosophila Models. Front Neurosci 2021; 15:786076. [PMID: 34899176 PMCID: PMC8652125 DOI: 10.3389/fnins.2021.786076] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 11/03/2021] [Indexed: 12/16/2022] Open
Abstract
Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are neurodegenerative disorders characterized by declining motor and cognitive functions. Even though these diseases present with distinct sets of symptoms, FTD and ALS are two extremes of the same disease spectrum, as they show considerable overlap in genetic, clinical and neuropathological features. Among these overlapping features, mitochondrial dysfunction is associated with both FTD and ALS. Recent studies have shown that cells derived from patients' induced pluripotent stem cells (iPSC)s display mitochondrial abnormalities, and similar abnormalities have been observed in a number of animal disease models. Drosophila models have been widely used to study FTD and ALS because of their rapid generation time and extensive set of genetic tools. A wide array of fly models have been developed to elucidate the molecular mechanisms of toxicity for mutations associated with FTD/ALS. Fly models have been often instrumental in understanding the role of disease associated mutations in mitochondria biology. In this review, we discuss how mutations associated with FTD/ALS disrupt mitochondrial function, and we review how the use of Drosophila models has been pivotal to our current knowledge in this field.
Collapse
Affiliation(s)
- Sharifah Anoar
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Nathaniel S Woodling
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Teresa Niccoli
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| |
Collapse
|
32
|
Lei XH, Bochner BR. Optimization of cell permeabilization in electron flow based mitochondrial function assays. Free Radic Biol Med 2021; 177:48-57. [PMID: 34656699 DOI: 10.1016/j.freeradbiomed.2021.10.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/05/2021] [Accepted: 10/13/2021] [Indexed: 12/21/2022]
Abstract
Permeable cell models have contributed much to the progress in mitochondrial research. Optimization of permeabilization is required to make the cell's plasma membrane permeable to small molecules while keeping the intracellular organelles and their membranes intact and fully functional. Here we report our assessment and optimization of commonly used permeabilizing agents including different saponin preparations, digitonin, and recombinant perfringolysin O employing a new electron flow based mitochondrial assay technology that utilizes a colorimetric redox dye. The results of this study provide guidance in optimizing the conditions for mitochondrial function assays with permeabilized cells using the novel redox dye-based format.
Collapse
Affiliation(s)
- Xiang-He Lei
- Biolog, Inc., 21124 Cabot Blvd., Hayward, CA, 94545, USA
| | | |
Collapse
|
33
|
Pilmark NS, Oberholzer L, Halling JF, Kristensen JM, Bønding CP, Elkjær I, Lyngbæk M, Elster G, Siebenmann C, Holm NF, Birk JBB, Larsen EL, Meinild-Lundby AK, Wojtaszewski JF, Pilegaard H, Poulsen H, Pedersen BK, Hansen KB, Karstoft K. Skeletal muscle adaptations to exercise are not influenced by metformin treatment in humans: secondary analyses of two randomised, clinical trials. Appl Physiol Nutr Metab 2021; 47:309-320. [PMID: 34784247 DOI: 10.1139/apnm-2021-0194] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Metformin and exercise both improve glycemic control, but in vitro studies have indicated that an interaction between metformin and exercise occurs in skeletal muscle, suggesting a blunting effect of metformin on exercise training adaptations. Two studies (a double-blind, parallel-group, randomized clinical trial conducted in 29 glucose-intolerant individuals and a double-blind, cross-over trial conducted in 15 healthy lean males) were included in this paper. In both studies, the effect of acute exercise +/- metformin treatment on different skeletal muscle variables, previously suggested to be involved in a pharmaco-physiological interaction between metformin and exercise, was assessed. Furthermore, in the parallel-group trial, the effect of 12 weeks of exercise training was assessed. Skeletal muscle biopsies were obtained before and after acute exercise and 12 weeks of exercise training, and mitochondrial respiration, oxidative stress and AMPK activation was determined. Metformin did not significantly affect the effects of acute exercise or exercise training on mitochondrial respiration, oxidative stress or AMPK activation, indicating that the response to acute exercise and exercise training adaptations in skeletal muscle is not affected by metformin treatment. Further studies are needed to investigate whether an interaction between metformin and exercise is present in other tissues, e.g. the gut. Trial registration: ClinicalTrials.gov (NCT03316690 and NCT02951260). Novelty bullets • Metformin does not affect exercise-induced alterations in mitochondrial respiratory capacity in human skeletal muscle • Metformin does not affect exercise-induced alterations in systemic levels of oxidative stress nor emission of reactive oxygen species from human skeletal muscle • Metformin does not affect exercise-induced AMPK activation in human skeletal muscle.
Collapse
Affiliation(s)
- Nanna Skytt Pilmark
- Rigshospitalet, 53146, Centre for Physical Activity Research (CFAS), Copenhagen, Denmark;
| | - Laura Oberholzer
- Center for Physical Activity Research, University Hospital of Copenhagen, Blegdamsvej 9, Copenhagen, Denmark, 2100;
| | - Jens Frey Halling
- university of copenhagen, department of biology, , copenhagen, Denmark;
| | - Jonas M Kristensen
- University of Copenhagen, Denmark, Department of Nutrition, Exercise and Sports,, copenhagen, Denmark;
| | | | - Ida Elkjær
- Center for Physical Activity Research, University Hospital of Copenhagen, Copenhagen, Denmark;
| | - Mark Lyngbæk
- Center for Physical Activity Research, University Hospital of Copenhagen, Copenhagen, Denmark;
| | - Grit Elster
- Center for Physical Activity Research, University Hospital of Copenhagen, Copenhagen, Denmark;
| | - Christoph Siebenmann
- Institute of Mountain Emergency Medicine,, EURAC Research, Bolzano, Italy, bolzano, Italy;
| | - Niels Frederich Holm
- Center for Physical Activity Research, University Hospital of Copenhagen, Copenhagen, Denmark;
| | - Jesper Bratz Bratz Birk
- University of Copenhagen, Denmark, Department of Nutrition, Exercise and Sports,, copenhagen, Denmark;
| | - Emil List Larsen
- Copenhagen University Hospital, 53146, Department of Clinical Pharmacology, Bispebjerg and Frederiksberg Hospital, Kobenhavn, Denmark;
| | | | - J F Wojtaszewski
- University of Copenhagen, Denmark, Department of Nutrition, Exercise and Sports,, copenhagen, Denmark;
| | | | - Henrik Poulsen
- Copenhagen University Hospital, 53146, Department of Clinical Pharmacology, Bispebjerg and Frederiksberg Hospital, Kobenhavn, Denmark;
| | - Bente Klarlund Pedersen
- Rigshospitalet, 53146, Centre of Inflammation and Metabolism / Centre for Physical Activity Research (CIM/CFAS), København, Denmark;
| | - Katrine Bagge Hansen
- Steno Diabetes Center Copenhagen, 53138, Steno Diabetes Center Copenhagen, Gentofte, Denmark, Gentofte, Denmark;
| | - Kristian Karstoft
- Rigshospitalet, 53146, Centre for Physical Activity Research (CFAS), Blegdamsvej 9, Copenhagen, Denmark, 2100.,Bispebjerg Hospital, 53166, Department of Clinical Pharmacology, Copenhagen, Denmark, 2400;
| |
Collapse
|
34
|
Lim Y, Cho IT, Rennke HG, Cho G. β2-adrenergic receptor regulates ER-mitochondria contacts. Sci Rep 2021; 11:21477. [PMID: 34728663 PMCID: PMC8563895 DOI: 10.1038/s41598-021-00801-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 10/07/2021] [Indexed: 12/05/2022] Open
Abstract
Interactions between the endoplasmic reticulum (ER) and mitochondria (Mito) are crucial for many cellular functions, and their interaction levels change dynamically depending on the cellular environment. Little is known about how the interactions between these organelles are regulated within the cell. Here we screened a compound library to identify chemical modulators for ER-Mito contacts in HEK293T cells. Multiple agonists of G-protein coupled receptors (GPCRs), beta-adrenergic receptors (β-ARs) in particular, scored in this screen. Analyses in multiple orthogonal assays validated that β2-AR activation promotes physical and functional interactions between the two organelles. Furthermore, we have elucidated potential downstream effectors mediating β2-AR-induced ER-Mito contacts. Together our study identifies β2-AR signaling as an important regulatory pathway for ER-Mito coupling and highlights the role of these contacts in responding to physiological demands or stresses.
Collapse
Affiliation(s)
- Youngshin Lim
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA
| | - Il-Taeg Cho
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Helmut G Rennke
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Ginam Cho
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
- Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA.
| |
Collapse
|
35
|
Nederveen JP, Manta K, Bujak AL, Simone AC, Fuda MR, Nilsson MI, Hettinga BP, Hughes MC, Perry CGR, Tarnopolsky MA. A Novel Multi-Ingredient Supplement Activates a Browning Program in White Adipose Tissue and Mitigates Weight Gain in High-Fat Diet-Fed Mice. Nutrients 2021; 13:3726. [PMID: 34835983 PMCID: PMC8623014 DOI: 10.3390/nu13113726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 10/11/2021] [Accepted: 10/14/2021] [Indexed: 12/15/2022] Open
Abstract
We investigated the effects of a novel multi-ingredient supplement comprised of polyphenol antioxidants and compounds known to facilitate mitochondrial function and metabolic enhancement (ME) in a mouse model of obesity. In this study, 6-week-old male C57/BL6J mice were placed on a high-fat diet (HFD; ~60% fat) for 6 weeks, with subsequent allocation into experimentalgroups for 4 weeks: HFD control, HFD + ME10 (10 components), HFD + ME7 (7 components), HFD + ME10 + EX, HFD + EX (where '+EX' animals exercised 3 days/week), and chow-fed control. After the intervention, HFD control animals had significantly greater body weight and fat mass. Despite the continuation of HFD, animals supplemented with multi-ingredient ME or who performed exercise training showed an attenuation of fat mass and preservation of lean body mass, which was further enhanced when combined (ME+EX). ME supplementation stimulated the upregulation of white and brown adipose tissue mRNA transcripts associated with mitochondrial biogenesis, browning, fatty acid transport, and fat metabolism. In WAT depots, this was mirrored by mitochodrial oxidative phosphorylation (OXPHOS) protein expression, and increased in vivo fat oxidation measured via CLAMS. ME supplementation also decreased systemic and local inflammation markers. Herein, we demonstrated that novel multi-ingredient nutritional supplements induced significant fat loss independent of physical activity while preserving muscle mass in obese mice. Mechanistically, these MEs appear to act by inducing a browning program in white adipose tissue and decreasing other pathophysiological impairments associated with obesity, including mitochondrial respiration alterations induced by HFD.
Collapse
Affiliation(s)
- Joshua P. Nederveen
- Department of Pediatrics, Faculty of Health Sciences, McMaster University Medical Centre (MUMC), 1200 Main St. W, Hamilton, ON L8N 3Z5, Canada; (J.P.N.); (K.M.); (A.C.S.); (M.R.F.)
| | - Katherine Manta
- Department of Pediatrics, Faculty of Health Sciences, McMaster University Medical Centre (MUMC), 1200 Main St. W, Hamilton, ON L8N 3Z5, Canada; (J.P.N.); (K.M.); (A.C.S.); (M.R.F.)
| | - Adam L. Bujak
- Exerkine Corporation, McMaster University Medical Centre (MUMC), 1200 Main St. W, Hamilton, ON L8N 3Z5, Canada; (A.L.B.); (M.I.N.); (B.P.H.)
| | - Alexander C. Simone
- Department of Pediatrics, Faculty of Health Sciences, McMaster University Medical Centre (MUMC), 1200 Main St. W, Hamilton, ON L8N 3Z5, Canada; (J.P.N.); (K.M.); (A.C.S.); (M.R.F.)
| | - Matthew R. Fuda
- Department of Pediatrics, Faculty of Health Sciences, McMaster University Medical Centre (MUMC), 1200 Main St. W, Hamilton, ON L8N 3Z5, Canada; (J.P.N.); (K.M.); (A.C.S.); (M.R.F.)
| | - Mats I. Nilsson
- Exerkine Corporation, McMaster University Medical Centre (MUMC), 1200 Main St. W, Hamilton, ON L8N 3Z5, Canada; (A.L.B.); (M.I.N.); (B.P.H.)
| | - Bart P. Hettinga
- Exerkine Corporation, McMaster University Medical Centre (MUMC), 1200 Main St. W, Hamilton, ON L8N 3Z5, Canada; (A.L.B.); (M.I.N.); (B.P.H.)
| | - Meghan C. Hughes
- Muscle Health Research Centre (MHRC), School of Kinesiology & Health Science, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada; (M.C.H.); (C.G.R.P.)
| | - Christopher G. R. Perry
- Muscle Health Research Centre (MHRC), School of Kinesiology & Health Science, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada; (M.C.H.); (C.G.R.P.)
| | - Mark A. Tarnopolsky
- Department of Pediatrics, Faculty of Health Sciences, McMaster University Medical Centre (MUMC), 1200 Main St. W, Hamilton, ON L8N 3Z5, Canada; (J.P.N.); (K.M.); (A.C.S.); (M.R.F.)
- Exerkine Corporation, McMaster University Medical Centre (MUMC), 1200 Main St. W, Hamilton, ON L8N 3Z5, Canada; (A.L.B.); (M.I.N.); (B.P.H.)
| |
Collapse
|
36
|
Schmidt CA, Fisher-Wellman KH, Neufer PD. From OCR and ECAR to energy: Perspectives on the design and interpretation of bioenergetics studies. J Biol Chem 2021; 297:101140. [PMID: 34461088 PMCID: PMC8479256 DOI: 10.1016/j.jbc.2021.101140] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 12/12/2022] Open
Abstract
Biological energy transduction underlies all physiological phenomena in cells. The metabolic systems that support energy transduction have been of great interest due to their association with numerous pathologies including diabetes, cancer, rare genetic diseases, and aberrant cell death. Commercially available bioenergetics technologies (e.g., extracellular flux analysis, high-resolution respirometry, fluorescent dye kits, etc.) have made practical assessment of metabolic parameters widely accessible. This has facilitated an explosion in the number of studies exploring, in particular, the biological implications of oxygen consumption rate (OCR) and substrate level phosphorylation via glycolysis (i.e., via extracellular acidification rate (ECAR)). Though these technologies have demonstrated substantial utility and broad applicability to cell biology research, they are also susceptible to historical assumptions, experimental limitations, and other caveats that have led to premature and/or erroneous interpretations. This review enumerates various important considerations for designing and interpreting cellular and mitochondrial bioenergetics experiments, some common challenges and pitfalls in data interpretation, and some potential "next steps" to be taken that can address these highlighted challenges.
Collapse
Affiliation(s)
- Cameron A Schmidt
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina, USA; Departments of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Kelsey H Fisher-Wellman
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina, USA; Departments of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
| | - P Darrell Neufer
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina, USA; Departments of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA; Departments of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
| |
Collapse
|
37
|
Mitochondria-localized AMPK responds to local energetics and contributes to exercise and energetic stress-induced mitophagy. Proc Natl Acad Sci U S A 2021; 118:2025932118. [PMID: 34493662 PMCID: PMC8449344 DOI: 10.1073/pnas.2025932118] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 08/05/2021] [Indexed: 12/25/2022] Open
Abstract
Mitochondria form a complex, interconnected reticulum that is maintained through coordination among biogenesis, dynamic fission, and fusion and mitophagy, which are initiated in response to various cues to maintain energetic homeostasis. These cellular events, which make up mitochondrial quality control, act with remarkable spatial precision, but what governs such spatial specificity is poorly understood. Herein, we demonstrate that specific isoforms of the cellular bioenergetic sensor, 5' AMP-activated protein kinase (AMPKα1/α2/β2/γ1), are localized on the outer mitochondrial membrane, referred to as mitoAMPK, in various tissues in mice and humans. Activation of mitoAMPK varies across the reticulum in response to energetic stress, and inhibition of mitoAMPK activity attenuates exercise-induced mitophagy in skeletal muscle in vivo. Discovery of a mitochondrial pool of AMPK and its local importance for mitochondrial quality control underscores the complexity of sensing cellular energetics in vivo that has implications for targeting mitochondrial energetics for disease treatment.
Collapse
|
38
|
Depletion of mitochondrial inorganic polyphosphate (polyP) in mammalian cells causes metabolic shift from oxidative phosphorylation to glycolysis. Biochem J 2021; 478:1631-1646. [PMID: 33843973 DOI: 10.1042/bcj20200975] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 04/08/2021] [Accepted: 04/12/2021] [Indexed: 12/11/2022]
Abstract
Inorganic polyphosphate (polyP) is a linear polymer composed of up to a few hundred orthophosphates linked together by high-energy phosphoanhydride bonds, identical with those found in ATP. In mammalian mitochondria, polyP has been implicated in multiple processes, including energy metabolism, ion channels function, and the regulation of calcium signaling. However, the specific mechanisms of all these effects of polyP within the organelle remain poorly understood. The central goal of this study was to investigate how mitochondrial polyP participates in the regulation of the mammalian cellular energy metabolism. To accomplish this, we created HEK293 cells depleted of mitochondrial polyP, through the stable expression of the polyP hydrolyzing enzyme (scPPX). We found that these cells have significantly reduced rates of oxidative phosphorylation (OXPHOS), while their rates of glycolysis were elevated. Consistent with this, metabolomics assays confirmed increased levels of metabolites involved in glycolysis in these cells, compared with the wild-type samples. At the same time, key respiratory parameters of the isolated mitochondria were unchanged, suggesting that respiratory chain activity is not affected by the lack of mitochondrial polyP. However, we detected that mitochondria from cells that lack mitochondrial polyP are more fragmented when compared with those from wild-type cells. Based on these results, we propose that mitochondrial polyP plays an important role as a regulator of the metabolic switch between OXPHOS and glycolysis.
Collapse
|
39
|
Willis W, Willis E, Kuzmiak-Glancy S, Kras K, Hudgens J, Barakati N, Stern J, Mandarino L. Oxidative phosphorylation K 0.5ADP in vitro depends on substrate oxidative capacity: Insights from a luciferase-based assay to evaluate ADP kinetic parameters. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148430. [PMID: 33887230 DOI: 10.1016/j.bbabio.2021.148430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/30/2021] [Accepted: 04/07/2021] [Indexed: 12/21/2022]
Abstract
The K0.5ADP of oxidative phosphorylation (OxPhos) identifies the cytosolic ADP concentration which elicits one-half the maximum OxPhos rate. This kinetic parameter is commonly measured to assess mitochondrial metabolic control sensitivity. Here we describe a luciferase-based assay to evaluate the ADP kinetic parameters of mitochondrial ATP production from OxPhos, adenylate kinase (AK), and creatine kinase (CK). The high sensitivity, reproducibility, and throughput of the microplate-based assay enabled a comprehensive kinetic assessment of all three pathways in mitochondria isolated from mouse liver, kidney, heart, and skeletal muscle. Carboxyatractyloside titrations were also performed with the assay to estimate the flux control strength of the adenine nucleotide translocase (ANT) over OxPhos in human skeletal muscle mitochondria. ANT flux control coefficients were 0.91 ± 0.07, 0.83 ± 0.06, and 0.51 ± 0.07 at ADP concentrations of 6.25, 12.5, and 25 μM, respectively, an [ADP] range which spanned the K0.5ADP. The oxidative capacity of substrate combinations added to drive OxPhos was found to dramatically influence ADP kinetics in mitochondria from several tissues. In mouse skeletal muscle ten different substrate combinations elicited a 7-fold range of OxPhos Vmax, which correlated positively (R2 = 0.963) with K0.5ADP values ranging from 2.3 ± 0.2 μM to 11.9 ± 0.6 μM. We propose that substrate-enhanced capacity to generate the protonmotive force increases the OxPhos K0.5ADP because flux control at ANT increases, thus K0.5ADP rises toward the dissociation constant, KdADP, of ADP-ANT binding. The findings are discussed in the context of top-down metabolic control analysis.
Collapse
Affiliation(s)
- Wayne Willis
- Department of Medicine, Division of Endocrinology, University of Arizona, Tucson, AZ, United States; Center for Disparities in Diabetes, Obesity, and Metabolism, University of Arizona, Tucson, AZ, United States.
| | - Elizabeth Willis
- College of Medicine, University of Kentucky, Lexington, KY, United States
| | - Sarah Kuzmiak-Glancy
- Department of Kinesiology, University of Maryland, College Park, MD, United States
| | - Katon Kras
- Department of Medicine, Division of Endocrinology, University of Arizona, Tucson, AZ, United States
| | - Jamie Hudgens
- College of Pharmacy, Midwestern University, Glendale, AZ, United States
| | - Neusha Barakati
- Department of Medicine, Division of Endocrinology, University of Arizona, Tucson, AZ, United States
| | - Jennifer Stern
- Department of Medicine, Division of Endocrinology, University of Arizona, Tucson, AZ, United States; Center for Disparities in Diabetes, Obesity, and Metabolism, University of Arizona, Tucson, AZ, United States
| | - Lawrence Mandarino
- Department of Medicine, Division of Endocrinology, University of Arizona, Tucson, AZ, United States; Center for Disparities in Diabetes, Obesity, and Metabolism, University of Arizona, Tucson, AZ, United States
| |
Collapse
|
40
|
Jacobs RA, Lundby C. Contextualizing the biological relevance of standardized high-resolution respirometry to assess mitochondrial function in permeabilized human skeletal muscle. Acta Physiol (Oxf) 2021; 231:e13625. [PMID: 33570804 PMCID: PMC8047922 DOI: 10.1111/apha.13625] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 12/16/2022]
Abstract
Aim This study sought to provide a statistically robust reference for measures of mitochondrial function from standardized high‐resolution respirometry with permeabilized human skeletal muscle (ex vivo), compare analogous values obtained via indirect calorimetry, arterial‐venous O2 differences and 31P magnetic resonance spectroscopy (in vivo) and attempt to resolve differences across complementary methodologies as necessary. Methods Data derived from 831 study participants across research published throughout March 2009 to November 2019 were amassed to examine the biological relevance of ex vivo assessments under standard conditions, ie physiological temperatures of 37°C and respiratory chamber oxygen concentrations of ~250 to 500 μmol/L. Results Standard ex vivo‐derived measures are lower (Z ≥ 3.01, P ≤ .0258) en masse than corresponding in vivo‐derived values. Correcting respiratory values to account for mitochondrial temperatures 10°C higher than skeletal muscle temperatures at maximal exercise (~50°C): (i) transforms data to resemble (Z ≤ 0.8, P > .9999) analogous yet context‐specific in vivo measures, eg data collected during maximal 1‐leg knee extension exercise; and (ii) supports the position that maximal skeletal muscle respiratory rates exceed (Z ≥ 13.2, P < .0001) those achieved during maximal whole‐body exercise, e.g. maximal cycling efforts. Conclusion This study outlines and demonstrates necessary considerations when actualizing the biological relevance of human skeletal muscle respiratory control, metabolic flexibility and bioenergetics from standard ex vivo‐derived assessments using permeabilized human muscle. These findings detail how cross‐procedural comparisons of human skeletal muscle mitochondrial function may be collectively scrutinized in their relationship to human health and lifespan.
Collapse
Affiliation(s)
- Robert A. Jacobs
- Department of Human Physiology & Nutrition University of Colorado Colorado Springs (UCCS) Colorado Springs CO USA
| | - Carsten Lundby
- Innland University of Applied Sciences Lillehammer Norway
| |
Collapse
|
41
|
Søndergård SD, Cintin I, Kuhlman AB, Morville TH, Bergmann ML, Kjær LK, Poulsen HE, Giustarini D, Rossi R, Dela F, Helge JW, Larsen S. The effects of 3 weeks of oral glutathione supplementation on whole body insulin sensitivity in obese males with and without type 2 diabetes: a randomized trial. Appl Physiol Nutr Metab 2021; 46:1133-1142. [PMID: 33740389 DOI: 10.1139/apnm-2020-1099] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effect of oral glutathione (GSH) supplementation was studied in obese subjects with and without type 2 diabetes (T2DM) on measures of glucose homeostasis and markers of oxidative stress. Twenty subjects (10 patients with T2DM and 10 obese subjects) were recruited for the study, and randomized in a double-blinded placebo-controlled manner to consume either 1000 mg GSH per day or placebo for 3 weeks. Before and after the 3 weeks insulin sensitivity was measured with the hyperinsulinemic-euglycemic clamp and a muscle biopsy was obtained to measure GSH and skeletal muscle mitochondrial hydrogen peroxide (H2O2) emission rate. Whole body insulin sensitivity increased significantly in the GSH group. Skeletal muscle GSH was numerically increased (∼19%) in the GSH group; no change was seen in GSH to glutathione disulfide ratio. Skeletal muscle mitochondrial H2O2 emission rate did not change in response to the intervention and neither did the urinary excretion of the RNA oxidation product 8-oxo-7,8-dihydroguanosine or the DNA oxidation product 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), although 8-oxodG decreased as a main effect of time. Oral GSH supplementation improves insulin sensitivity in obese subjects with and without T2DM, although it does not alter markers of oxidative stress. The study has been registered in clinicaltrials.gov (NCT02948673). Novelty: Reduced glutathione supplementation increases insulin sensitivity in obese subjects with and without T2DM. H2O2 emission rate from skeletal muscle mitochondria was not affected by GSH supplementation.
Collapse
Affiliation(s)
- Stine D Søndergård
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ida Cintin
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anja B Kuhlman
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas H Morville
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Marie Louise Bergmann
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Laura K Kjær
- Laboratory of Clinical Pharmacology, Department of Clinical Pharmacology, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Henrik E Poulsen
- Laboratory of Clinical Pharmacology, Department of Clinical Pharmacology, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Daniela Giustarini
- Department of Biotechnology Chemistry and Pharmacy, University of Siena, Siena, Italy
| | - Ranieri Rossi
- Department of Biotechnology Chemistry and Pharmacy, University of Siena, Siena, Italy
| | - Flemming Dela
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Geriatrics, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Jørn W Helge
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Steen Larsen
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.,Clinical Research Centre, Medical University of Bialystok, Bialystok, Poland
| |
Collapse
|
42
|
Santos CS, Macedo F, Kowaltowski AJ, Bertotti M, Unwin PR, Marques da Cunha F, Meloni GN. Unveiling the contribution of the reproductive system of individual Caenorhabditis elegans on oxygen consumption by single-point scanning electrochemical microscopy measurements. Anal Chim Acta 2021; 1146:88-97. [PMID: 33461723 PMCID: PMC7836392 DOI: 10.1016/j.aca.2020.12.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/11/2020] [Accepted: 12/17/2020] [Indexed: 01/03/2023]
Abstract
Metabolic analysis in animals is usually either evaluated as whole-body measurements or in isolated tissue samples. To reveal tissue specificities in vivo, this study uses scanning electrochemical microscopy (SECM) to provide localized oxygen consumption rates (OCRs) in different regions of single adult Caenorhabditis elegans individuals. This is achieved by measuring the oxygen reduction current at the SECM tip electrode and using a finite element method model of the experiment that defines oxygen concentration and flux at the surface of the organism. SECM mapping measurements uncover a marked heterogeneity of OCR along the worm, with high respiration rates at the reproductive system region. To enable sensitive and quantitative measurements, a self-referencing approach is adopted, whereby the oxygen reduction current at the SECM tip is measured at a selected point on the worm and in bulk solution (calibration). Using genetic and pharmacological approaches, our SECM measurements indicate that viable eggs in the reproductive system are the main contributors in the total oxygen consumption of adult Caenorhabditis elegans. The finding that large regional differences in OCR exist within the animal provides a new understanding of oxygen consumption and metabolic measurements, paving the way for tissue-specific metabolic analyses and toxicity evaluation within single organisms.
Collapse
Affiliation(s)
- Carla S Santos
- Departamento de Química Fundamental, Av. Professor Lineu Prestes, 748, 05508-000, São Paulo, SP, Brazil.
| | - Felipe Macedo
- Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua três de Maio, 100, 04044-020, São Paulo, Brazil
| | - Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av. Professor Lineu Prestes, 748, 05508-000, São Paulo, SP, Brazil
| | - Mauro Bertotti
- Departamento de Química Fundamental, Av. Professor Lineu Prestes, 748, 05508-000, São Paulo, SP, Brazil
| | - Patrick R Unwin
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom; Bio-Electrical Engineering Innovation Hub, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Fernanda Marques da Cunha
- Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua três de Maio, 100, 04044-020, São Paulo, Brazil
| | - Gabriel N Meloni
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom; Bio-Electrical Engineering Innovation Hub, University of Warwick, Coventry, CV4 7AL, United Kingdom.
| |
Collapse
|
43
|
Tyrrell DJ, Blin MG, Song J, Wood SC, Goldstein DR. Aging Impairs Mitochondrial Function and Mitophagy and Elevates Interleukin 6 Within the Cerebral Vasculature. J Am Heart Assoc 2020; 9:e017820. [PMID: 33225820 PMCID: PMC7763766 DOI: 10.1161/jaha.120.017820] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Background The blood-brain barrier (BBB) is critical for cerebrovascular health. Although aging impairs the integrity of the BBB, the mechanisms behind this phenomenon are not clear. As mitochondrial components activate inflammation as mitochondria become dysfunctional, we examined how aging impacts cerebrovascular mitochondrial function, mitophagy, and inflammatory signaling; and whether any alterations correlate with BBB function. Methods and Results We isolated cerebral vessels from young (2-3 months of age) and aged (18-19 months of age) mice and found that aging led to increases in the cyclin-dependent kinase inhibitor 1 senescence marker with impaired mitochondrial function, which correlated with aged mice exhibiting increased BBB leak compared with young mice. Cerebral vessels also exhibited increased expression of mitophagy proteins Parkin and Nix with aging. Using mitophagy reporter (mtKeima) mice, we found that the capacity to increase mitophagy from baseline within the cerebral vessels on rotenone treatment was reduced with aging. Aging within the cerebral vessels also led to the upregulation of the stimulator of interferon genes and increased interleukin 6 (IL-6), a cytokine that alters mitochondrial function. Importantly, exogenous IL-6 treatment of young cerebral vessels upregulated mitophagy and Parkin and impaired mitochondrial function; whereas inhibiting IL-6 in aged cerebral vessels reduced Parkin expression and increased mitochondrial function. Furthermore, treating cerebral vessels of young mice with mitochondrial N-formyl peptides upregulated IL-6, increased Parkin, and reduced Claudin-5, a tight junction protein integral to BBB integrity. Conclusions Aging alters the cerebral vasculature to impair mitochondrial function and mitophagy and increase IL-6 levels. These alterations may impair BBB integrity and potentially reduce cerebrovascular health with aging.
Collapse
Affiliation(s)
| | - Muriel G. Blin
- Department of Internal MedicineUniversity of MichiganAnn ArborMI
| | - Jianrui Song
- Department of Internal MedicineUniversity of MichiganAnn ArborMI
| | - Sherri C. Wood
- Department of Internal MedicineUniversity of MichiganAnn ArborMI
| | - Daniel R. Goldstein
- Department of Internal MedicineUniversity of MichiganAnn ArborMI,Department of Microbiology and ImmunologyUniversity of MichiganAnn ArborMI,Institute of GerontologyUniversity of MichiganAnn ArborMI
| |
Collapse
|
44
|
Jones AE, Sheng L, Acevedo A, Veliova M, Shirihai OS, Stiles L, Divakaruni AS. Forces, fluxes, and fuels: tracking mitochondrial metabolism by integrating measurements of membrane potential, respiration, and metabolites. Am J Physiol Cell Physiol 2020; 320:C80-C91. [PMID: 33147057 DOI: 10.1152/ajpcell.00235.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Assessing mitochondrial function in cell-based systems is a central component of metabolism research. However, the selection of an initial measurement technique may be complicated given the range of parameters that can be studied and the need to define the mitochondrial (dys)function of interest. This methods-focused review compares and contrasts the use of mitochondrial membrane potential measurements, plate-based respirometry, and metabolomics and stable isotope tracing. We demonstrate how measurements of 1) cellular substrate preference, 2) respiratory chain activity, 3) cell activation, and 4) mitochondrial biogenesis are enriched by integrating information from multiple methods. This manuscript is meant to serve as a perspective to help choose which technique might be an appropriate initial method to answer a given question, as well as provide a broad "roadmap" for designing follow-up assays to enrich datasets or resolve ambiguous results.
Collapse
Affiliation(s)
- Anthony E Jones
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California
| | - Li Sheng
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California
| | - Aracely Acevedo
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California
| | - Michaela Veliova
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California.,Department of Medicine, University of California, Los Angeles, California
| | - Orian S Shirihai
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California.,Department of Medicine, University of California, Los Angeles, California
| | - Linsey Stiles
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California.,Department of Medicine, University of California, Los Angeles, California
| | - Ajit S Divakaruni
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California
| |
Collapse
|
45
|
Rickard AG, Zhuang M, DeRosa CA, Zhang X, Dewhirst MW, Fraser CL, Palmer GM. Dual-emissive, oxygen-sensing boron nanoparticles quantify oxygen consumption rate in breast cancer cells. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:JBO-200174RR. [PMID: 33231018 PMCID: PMC7682476 DOI: 10.1117/1.jbo.25.11.116504] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/30/2020] [Indexed: 06/11/2023]
Abstract
SIGNIFICANCE Decreasing the oxygen consumption rate (OCR) of tumor cells is a powerful method for ameliorating tumor hypoxia. However, quantifying the change in OCR is challenging in complex experimental systems. AIM We present a method for quantifying the OCR of two tumor cell lines using oxygen-sensitive dual-emissive boron nanoparticles (BNPs). We hypothesize that our BNP results are equivalent to the standard Seahorse assay. APPROACH We quantified the spectral emissions of the BNP and accounted for external oxygen diffusion to quantify OCR over 24 h. The BNP-computed OCR of two breast cancer cell lines, E0771 and 4T07, were compared with their respective Seahorse assays. Both cell lines were also irradiated to quantify radiation-induced changes in the OCR. RESULTS Using a Bland-Altman analysis, our BNPs OCR was equivalent to the standard Seahorse assay. Moreover, in an additional experiment in which we irradiated the cells at their 50% survival fraction, the BNPs were sensitive enough to quantify 24% reduction in OCR after irradiation. CONCLUSIONS Our results conclude that the BNPs are a viable alternative to the Seahorse assay for quantifying the OCR in cells. The Bland-Altman analysis showed that these two methods result in equivalent OCR measurements. Future studies will extend the OCR measurements to complex systems including 3D cultures and in vivo models, in which OCR measurements cannot currently be made.
Collapse
Affiliation(s)
- Ashlyn G. Rickard
- Duke University, Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States
| | - Meng Zhuang
- University of Virginia, Department of Chemistry, Charlottesville, Virginia, United States
| | - Christopher A. DeRosa
- University of Virginia, Department of Chemistry, Charlottesville, Virginia, United States
| | - Xiaojie Zhang
- Duke University, Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States
| | - Mark W. Dewhirst
- Duke University, Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States
| | - Cassandra L. Fraser
- University of Virginia, Department of Chemistry, Charlottesville, Virginia, United States
| | - Gregory M. Palmer
- Duke University, Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States
| |
Collapse
|
46
|
Ramos SV, Hughes MC, Delfinis LJ, Bellissimo CA, Perry CGR. Mitochondrial bioenergetic dysfunction in the D2.mdx model of Duchenne muscular dystrophy is associated with microtubule disorganization in skeletal muscle. PLoS One 2020; 15:e0237138. [PMID: 33002037 PMCID: PMC7529311 DOI: 10.1371/journal.pone.0237138] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Accepted: 07/21/2020] [Indexed: 11/25/2022] Open
Abstract
In Duchenne muscular dystrophy, a lack of dystrophin leads to extensive muscle weakness and atrophy that is linked to cellular metabolic dysfunction and oxidative stress. This dystrophinopathy results in a loss of tethering between microtubules and the sarcolemma. Microtubules are also believed to regulate mitochondrial bioenergetics potentially by binding the outer mitochondrial membrane voltage dependent anion channel (VDAC) and influencing permeability to ADP/ATP cycling. The objective of this investigation was to determine if a lack of dystrophin causes microtubule disorganization concurrent with mitochondrial dysfunction in skeletal muscle, and whether this relationship is linked to altered binding of tubulin to VDAC. In extensor digitorum longus (EDL) muscle from 4-week old D2.mdx mice, microtubule disorganization was observed when probing for α-tubulin. This cytoskeletal disorder was associated with a reduced ability of ADP to stimulate respiration and attenuate H2O2 emission relative to wildtype controls. However, this was not associated with altered α-tubulin-VDAC2 interactions. These findings reveal that microtubule disorganization in dystrophin-deficient EDL is associated with impaired ADP control of mitochondrial bioenergetics, and suggests that mechanisms alternative to α-tubulin’s regulation of VDAC2 should be examined to understand how cytoskeletal disruption in the absence of dystrophin may cause metabolic dysfunctions in skeletal muscle.
Collapse
Affiliation(s)
- Sofhia V. Ramos
- School of Kinesiology and Health Sciences, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Meghan C. Hughes
- School of Kinesiology and Health Sciences, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Luca J. Delfinis
- School of Kinesiology and Health Sciences, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Catherine A. Bellissimo
- School of Kinesiology and Health Sciences, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Christopher G. R. Perry
- School of Kinesiology and Health Sciences, Muscle Health Research Centre, York University, Toronto, Ontario, Canada
- * E-mail:
| |
Collapse
|
47
|
Impaired mitochondrial function of alveolar macrophages in carbon nanotube-induced chronic pulmonary granulomatous disease. Toxicology 2020; 445:152598. [PMID: 32976959 DOI: 10.1016/j.tox.2020.152598] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 09/15/2020] [Accepted: 09/18/2020] [Indexed: 12/18/2022]
Abstract
Human exposure to carbon nanotubes (CNT) has been associated with the development of pulmonary sarcoid-like granulomatous disease. Our previous studies demonstrated that multi-walled carbon nanotubes (MWCNT) induced chronic pulmonary granulomatous inflammation in mice. Granuloma formation was accompanied by decreased peroxisome proliferator-activated receptor gamma (PPARγ) and disrupted intracellular lipid homeostasis in alveolar macrophages. Others have shown that PPARγ activation increases mitochondrial fatty acid oxidation (FAO) to reduce free fatty acid accumulation. Hence, we hypothesized that the disrupted lipid metabolism suppresses mitochondrial FAO. To test our hypothesis, C57BL/6 J mice were instilled by an oropharyngeal route with 100 μg MWCNT freshly suspended in 35 % Infasurf. Control sham mice received vehicle alone. Sixty days following instillation, mitochondrial FAO was measured in permeabilized bronchoalveolar lavage (BAL) cells. MWCNT instillation reduced the mitochondrial oxygen consumption rate of BAL cells in the presence of palmitoyl-carnitine as mitochondrial fuel. MWCNT also reduced mRNA expression of mitochondrial genes regulating FAO, carnitine palmitoyl transferase-1 (CPT1), carnitine palmitoyl transferase-2 (CPT2), hydroxyacyl-CoA dehydrogenase subunit beta (HADHB), and PPARγ coactivator 1 alpha (PPARGC1A). Importantly, both oxidative stress and apoptosis in alveolar macrophages and lung tissues of MWCNT-instilled mice were increased. Because macrophage PPARγ expression has been reported to be controlled by miR-27b which is known to induce oxidative stress and apoptosis, we measured the expression of miR-27b. Results indicated elevated levels in alveolar macrophages from MWCNT-instilled mice compared to controls. Given that inhibition of FAO and apoptosis are linked to M1 and M2 macrophage activation, respectively, the expression of both M1 and M2 key indicator genes were measured. Interestingly, results showed that both M1 and M2 phenotypes of alveolar macrophages were activated in MWCNT-instilled mice. In conclusion, alveolar macrophages of MWCNT-instilled mice had increased miR-27b expression, which may reduce the expression of PPARγ resulting in attenuation of FAO. This reduction in FAO may lead to activation of M1 macrophages. The upregulation of miR-27b may also induce apoptosis, which in turn can cause M2 activation of alveolar macrophages. These observations indicate a possible role of miR-27b in impaired mitochondrial function in the chronic activation of alveolar macrophages by MWCNT and the development of chronic pulmonary granulomatous inflammation.
Collapse
|
48
|
Caspi T, Straw S, Cheng C, Garnham JO, Scragg JL, Smith J, Koshy AO, Levelt E, Sukumar P, Gierula J, Beech DJ, Kearney MT, Cubbon RM, Wheatcroft SB, Witte KK, Roberts LD, Bowen TS. Unique Transcriptome Signature Distinguishes Patients With Heart Failure With Myopathy. J Am Heart Assoc 2020; 9:e017091. [PMID: 32892688 PMCID: PMC7727001 DOI: 10.1161/jaha.120.017091] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Background People with chronic heart failure (CHF) experience severe skeletal muscle dysfunction, characterized by mitochondrial abnormalities, which exacerbates the primary symptom of exercise intolerance. However, the molecular triggers and characteristics underlying mitochondrial abnormalities caused by CHF remain poorly understood. Methods and Results We recruited 28 patients with CHF caused by reduced ejection fraction and 9 controls. We simultaneously biopsied skeletal muscle from the pectoralis major in the upper limb and from the vastus lateralis in the lower limb. We phenotyped mitochondrial function in permeabilized myofibers from both sites and followed this by complete RNA sequencing to identify novel molecular abnormalities in CHF skeletal muscle. Patients with CHF presented with upper and lower limb skeletal muscle impairments to mitochondrial function that were of a similar deficit and indicative of a myopathy. Mitochondrial abnormalities were strongly correlated to symptoms. Further RNA sequencing revealed a unique transcriptome signature in CHF skeletal muscle characterized by a novel triad of differentially expressed genes related to deficits in energy metabolism including adenosine monophosphate deaminase 3, pyridine nucleotide-disulphide oxidoreductase domain 2, and lactate dehydrogenase C. Conclusions Our data suggest an upper and lower limb metabolic myopathy that is characterized by a unique transcriptome signature in skeletal muscle of humans with CHF.
Collapse
Affiliation(s)
- Talia Caspi
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - Sam Straw
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - Chew Cheng
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - Jack O Garnham
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - Jason L Scragg
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - Jessica Smith
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - Aaron O Koshy
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - Eylem Levelt
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - Piruthivi Sukumar
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - John Gierula
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - David J Beech
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - Mark T Kearney
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - Richard M Cubbon
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - Stephen B Wheatcroft
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - Klaus K Witte
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - Lee D Roberts
- Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds United Kingdom
| | - T Scott Bowen
- School of Biomedical Sciences Faculty of Biological Sciences University of Leeds United Kingdom
| |
Collapse
|
49
|
Kruse R, Sahebekhtiari N, Højlund K. The Mitochondrial Proteomic Signatures of Human Skeletal Muscle Linked to Insulin Resistance. Int J Mol Sci 2020; 21:ijms21155374. [PMID: 32731645 PMCID: PMC7432338 DOI: 10.3390/ijms21155374] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/20/2020] [Accepted: 07/26/2020] [Indexed: 12/12/2022] Open
Abstract
Introduction: Mitochondria are essential in energy metabolism and cellular survival, and there is growing evidence that insulin resistance in chronic metabolic disorders, such as obesity, type 2 diabetes (T2D), and aging, is linked to mitochondrial dysfunction in skeletal muscle. Protein profiling by proteomics is a powerful tool to investigate mechanisms underlying complex disorders. However, despite significant advances in proteomics within the past two decades, the technologies have not yet been fully exploited in the field of skeletal muscle proteome. Area covered: Here, we review the currently available studies characterizing the mitochondrial proteome in human skeletal muscle in insulin-resistant conditions, such as obesity, T2D, and aging, as well as exercise-mediated changes in the mitochondrial proteome. Furthermore, we outline technical challenges and limitations and methodological aspects that should be considered when planning future large-scale proteomics studies of mitochondria from human skeletal muscle. Authors’ view: At present, most proteomic studies of skeletal muscle or isolated muscle mitochondria have demonstrated a reduced abundance of proteins in several mitochondrial biological processes in obesity, T2D, and aging, whereas the beneficial effects of exercise involve an increased content of muscle proteins involved in mitochondrial metabolism. Powerful mass-spectrometry-based proteomics now provides unprecedented opportunities to perform in-depth proteomics of muscle mitochondria, which in the near future is expected to increase our understanding of the complex molecular mechanisms underlying the link between mitochondrial dysfunction and insulin resistance in chronic metabolic disorders.
Collapse
Affiliation(s)
- Rikke Kruse
- Steno Diabetes Center Odense, Odense University Hospital, DK-5000 Odense C, Denmark; (R.K.); (N.S.)
- Department of Clinical Research & Department of Molecular Medicine, University of Southern Denmark, DK-5000 Odense C, Denmark
| | - Navid Sahebekhtiari
- Steno Diabetes Center Odense, Odense University Hospital, DK-5000 Odense C, Denmark; (R.K.); (N.S.)
- Department of Clinical Research & Department of Molecular Medicine, University of Southern Denmark, DK-5000 Odense C, Denmark
| | - Kurt Højlund
- Steno Diabetes Center Odense, Odense University Hospital, DK-5000 Odense C, Denmark; (R.K.); (N.S.)
- Department of Clinical Research & Department of Molecular Medicine, University of Southern Denmark, DK-5000 Odense C, Denmark
- Correspondence: ; Tel.: +45-2532-06-48
| |
Collapse
|
50
|
Li Puma LC, Hedges M, Heckman JM, Mathias AB, Engstrom MR, Brown AB, Chicco AJ. Experimental oxygen concentration influences rates of mitochondrial hydrogen peroxide release from cardiac and skeletal muscle preparations. Am J Physiol Regul Integr Comp Physiol 2020; 318:R972-R980. [PMID: 32233925 DOI: 10.1152/ajpregu.00227.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mitochondria utilize the majority of oxygen (O2) consumed by aerobic organisms as the final electron acceptor for oxidative phosphorylation (OXPHOS) but also to generate reactive oxygen species (mtROS) that participate in cell signaling, physiological hormesis, and disease pathogenesis. Simultaneous monitoring of mtROS production and oxygen consumption (Jo2) from tissue mitochondrial preparations is an attractive investigative approach, but it introduces dynamic changes in media O2 concentration ([O2]) that can confound experimental results and interpretation. We utilized high-resolution fluorespirometry to evaluate Jo2 and hydrogen peroxide release (Jh2o2) from isolated mitochondria (Mt), permeabilized fibers (Pf), and tissue homogenates (Hm) prepared from murine heart and skeletal muscle across a range of experimental [O2]s typically encountered during respirometry protocols (400-50 µM). Results demonstrate notable variations in Jh2o2 across tissues and sample preparations during nonphosphorylating (LEAK) and OXPHOS-linked respiration states at 250 µM [O2] but a linear decline in Jh2o2 of 5-15% per 50-µM decrease in chamber [O2] in all samples. Jo2 was generally stable in Mt and Hm across [O2]s above 50 µM but tended to decline below 250 µM in Pf, leading to wide variations in assayed rates of Jh2o2/O2 across chamber [O2]s and sample preparations. Development of chemical background fluorescence from the H2O2 probe (Amplex Red) was also O2 sensitive, emphasizing relevant calibration considerations. This study highlights the importance of monitoring and reporting the chamber [O2] at which Jo2 and Jh2o2 are recorded during fluorespirometry experiments and provides a basis for selecting sample preparations for studies addressing the role of mtROS in physiology and disease.
Collapse
Affiliation(s)
- Lance C Li Puma
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Michael Hedges
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado
| | - Joseph M Heckman
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Alissa B Mathias
- Program in Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado
| | - Madison R Engstrom
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Abigail B Brown
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Adam J Chicco
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado.,Program in Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado
| |
Collapse
|