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Massier L, Musat N, Stumvoll M, Tremaroli V, Chakaroun R, Kovacs P. Tissue-resident bacteria in metabolic diseases: emerging evidence and challenges. Nat Metab 2024:10.1038/s42255-024-01065-0. [PMID: 38898236 DOI: 10.1038/s42255-024-01065-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/13/2024] [Indexed: 06/21/2024]
Abstract
Although the impact of the gut microbiome on health and disease is well established, there is controversy regarding the presence of microorganisms such as bacteria and their products in organs and tissues. However, recent contamination-aware findings of tissue-resident microbial signatures provide accumulating evidence in support of bacterial translocation in cardiometabolic disease. The latter provides a distinct paradigm for the link between microbial colonizers of mucosal surfaces and host metabolism. In this Perspective, we re-evaluate the concept of tissue-resident bacteria including their role in metabolic low-grade tissue and systemic inflammation. We examine the limitations and challenges associated with studying low bacterial biomass samples and propose experimental and analytical strategies to overcome these issues. Our Perspective aims to encourage further investigation of the mechanisms linking tissue-resident bacteria to host metabolism and their potentially actionable health implications for prevention and treatment.
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Affiliation(s)
- Lucas Massier
- Department of Medicine (H7), Karolinska Institutet, Stockholm, Sweden
| | - Niculina Musat
- Aarhus University, Department of Biology, Section for Microbiology, Århus, Denmark
| | - Michael Stumvoll
- Medical Department III - Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
| | - Valentina Tremaroli
- Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Rima Chakaroun
- Medical Department III - Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany.
- Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.
| | - Peter Kovacs
- Medical Department III - Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany.
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2
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Luo J, Alkhalidy H, Jia Z, Liu D. Sulforaphane Ameliorates High-Fat-Diet-Induced Metabolic Abnormalities in Young and Middle-Aged Obese Male Mice. Foods 2024; 13:1055. [PMID: 38611359 PMCID: PMC11012181 DOI: 10.3390/foods13071055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 03/23/2024] [Accepted: 03/26/2024] [Indexed: 04/14/2024] Open
Abstract
Type 2 diabetes (T2D) is still a fast-growing health problem globally. It is evident that chronic insulin resistance (IR) and progressive loss of β-cell mass and function are key features of T2D etiology. Obesity is a leading pathogenic factor for developing IR. The aim of the present study was to determine whether sulforaphane (SFN), a natural compound derived from cruciferous vegetables, can prevent (prevention approach) or treat (treatment approach) obesity and IR in mouse models. We show that dietary intake of SFN (0.5 g/kg of HFD) for 20 weeks suppressed high-fat diet (HFD)-induced fat accumulation by 6.04% and improved insulin sensitivity by 23.66% in young male mice. Similarly, dietary provision of SFN (0.25 g/kg) significantly improved blood lipid profile, glucose tolerance, and insulin sensitivity of the middle-aged male mice while it had little effects on body composition as compared with the HFD group. In the treatment study, oral administration of SFN (40 mg/kg) induced weight loss and improved insulin sensitivity and plasma lipid profile in the diet-induced-obesity (DIO) male mice. In all three studies, the metabolic effects of SFN administration were not associated with changes in food intake. In vitro, SFN increased glucose uptake in C2C12 myotubes and increased fatty acid and pyruvate oxidation in primary human skeletal muscle cells. Our results suggest that SFN may be a naturally occurring insulin-sensitizing agent that is capable of improving the metabolic processes in HFD-induced obesity and IR and thereby may be a promising compound for T2D prevention.
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Affiliation(s)
- Jing Luo
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China;
- Department of Human Nutrition, Foods, and Exercise, College of Agricultural and Life Sciences, Virginia Tech, Blacksburg, VA 24060, USA;
| | - Hana Alkhalidy
- Department of Human Nutrition, Foods, and Exercise, College of Agricultural and Life Sciences, Virginia Tech, Blacksburg, VA 24060, USA;
- Department of Nutrition and Food Technology, Faculty of Agriculture, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Zhenquan Jia
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC 27412, USA;
| | - Dongmin Liu
- Department of Human Nutrition, Foods, and Exercise, College of Agricultural and Life Sciences, Virginia Tech, Blacksburg, VA 24060, USA;
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Tincknell JB, Kugler BA, Spicuzza H, Berger N, Yan H, You T, Zou K. High-intensity interval training attenuates impairment in regulatory protein machinery of mitochondrial quality control in skeletal muscle of diet-induced obese mice. Appl Physiol Nutr Metab 2024; 49:236-249. [PMID: 37852013 DOI: 10.1139/apnm-2023-0286] [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: 10/20/2023]
Abstract
Mitochondrial quality control processes are essential in governing mitochondrial integrity and function. The purpose of the study was to examine the effects of 10 weeks of high-intensity interval training (HIIT) on the regulatory protein machinery of skeletal muscle mitochondrial quality control and whole-body glucose homeostasis in diet-induced obese mice. Male C57BL/6 mice were assigned to low-fat diet (LFD) or high-fat diet (HFD) group. After 10 weeks, HFD-fed mice were divided into sedentary and HIIT (HFD + HIIT) groups for another 10 weeks (n = 9/group). Graded exercise test, glucose and insulin tolerance tests, mitochondrial respiration, and protein markers of mitochondrial quality control processes were determined. HFD-fed mice exhibited lower ADP-stimulated mitochondrial respiration (p < 0.05). However, 10 weeks of HIIT prevented this impairment (p < 0.05). Importantly, the ratio of Drp1(Ser616) over Drp1(Ser637) phosphorylation, an indicator of mitochondrial fission, was significantly higher in HFD-fed mice (p < 0.05), but such increase was attenuated in HFD-HIIT compared to HFD (-35.7%, p < 0.05). Regarding autophagy, skeletal muscle p62 content was lower in the HFD group than the LFD group (-35.1%, p < 0.05); however, such reduction was disappeared in the HFD + HIIT group. In addition, LC3B II/I ratio was higher in the HFD group than the LFD group (15.5%, p < 0.05) but was ameliorated in the HFD + HIIT group (-29.9%, p < 0.05). Overall, our study demonstrated that 10 weeks of HIIT was effective in improving skeletal muscle mitochondrial respiration and the regulatory protein machinery of mitochondrial quality control in diet-induced obese mice through the alterations of mitochondrial fission protein Drp1 phosphorylations and p62/LC3B-mediated regulatory machinery of autophagy.
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Affiliation(s)
- James B Tincknell
- Department of Exercise and Health SciencesManning College of Nursing and Health Sciences, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Benjamin A Kugler
- Department of Exercise and Health SciencesManning College of Nursing and Health Sciences, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Haley Spicuzza
- Department of Exercise and Health SciencesManning College of Nursing and Health Sciences, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Nicolas Berger
- Department of Exercise and Health SciencesManning College of Nursing and Health Sciences, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Huimin Yan
- Department of Exercise and Health SciencesManning College of Nursing and Health Sciences, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Tongjian You
- Department of Exercise and Health SciencesManning College of Nursing and Health Sciences, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Kai Zou
- Department of Exercise and Health SciencesManning College of Nursing and Health Sciences, University of Massachusetts Boston, Boston, MA 02125, USA
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4
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Tobin SW, Seneviratne D, Phan L, Seegobin M, Rico AL, Westby B, Kisiala A, Martic S, Brunetti CR, Emery RJN. Profiling of adenine-derived signaling molecules, cytokinins, in myotubes reveals fluctuations in response to lipopolysaccharide-induced cell stress. Physiol Rep 2023; 11:e15870. [PMID: 38040455 PMCID: PMC10691934 DOI: 10.14814/phy2.15870] [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: 10/13/2023] [Revised: 11/03/2023] [Accepted: 11/05/2023] [Indexed: 12/03/2023] Open
Abstract
Cytokinins (CTKs) are a diverse collection of evolutionarily conserved adenine-derived signaling molecules classically studied as phytohormones; however, their roles and production have been less studied in mammalian systems. Skeletal muscles are sensitive to cellular cues such as inflammation and in response, alter their secretome to regulate the muscle stem cell and myofiber niche. Using cultured C2C12 muscle cells, we profiled CTK levels to understand (1) whether CTKs are part of the muscle secretome and (2) whether CTKs are responsive to cellular stress. To induce cellular stress, C2C12 myotubes were treated with lipopolysaccharides (LPS) for 24 h and then media and cell fractions were collected for ultra high-performance liquid chromatography tandem mass spectrometry with electrospray ionization (UHPLC-(ESI+)-HRMS/MS) for metabolomics and CTK profiling. Across LPS-treated and control cells, 11 CTKs were detected in the extracellular space while 6 were detected intracellularly. We found that muscle cells are enriched in isopentenyladenine (iP) species (from free base, riboside to nucleotide forms), and that extracellular levels are increased after LPS treatment. Our study establishes that muscle cells express various forms of CTKs, and that CTK levels are responsive to LPS-induced cell stress, suggesting a role for CTKs in intra- and extracellular signaling of mammalian cells.
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Affiliation(s)
- Stephanie W. Tobin
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughOntarioCanada
| | - Dev Seneviratne
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughOntarioCanada
- Department of Forensic ScienceTrent UniversityPeterboroughCanada
| | - Lorna Phan
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
| | - Mark Seegobin
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughOntarioCanada
| | | | - Beth Westby
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
| | - Anna Kisiala
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
| | - Sanela Martic
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughOntarioCanada
- Department of Forensic ScienceTrent UniversityPeterboroughCanada
| | - Craig R. Brunetti
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughOntarioCanada
| | - R. J. Neil Emery
- Department of BiologyTrent UniversityPeterboroughOntarioCanada
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughOntarioCanada
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5
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Tincknell JB, Kugler B, Spicuzza H, Yan H, You T, Zou K. High-Intensity Interval Training Attenuates Impairment in Regulatory Protein Machinery of Mitochondrial Quality Control in Skeletal Muscle of Diet-Induced Obese Mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.28.546902. [PMID: 37425824 PMCID: PMC10326985 DOI: 10.1101/2023.06.28.546902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Mitochondrial quality control processes are essential in governing mitochondrial integrity and function. The purpose of the study was to examine the effects of 10 weeks of HIIT on the regulatory protein machinery of skeletal muscle mitochondrial quality control and whole-body glucose homeostasis in diet-induced obese mice. Male C57BL/6 mice were randomly assigned to a low-fat diet (LFD) or high-fat diet (HFD) group. After 10 weeks, HFD-fed mice were divided into sedentary and HIIT (HFD+HIIT) groups and remained on HFD for another 10 weeks (n=9/group). Graded exercise test, glucose and insulin tolerance tests, mitochondrial respiration and regulatory protein markers of mitochondrial quality control processes were determined by immunoblots. Ten weeks of HIIT enhanced ADP-stimulated mitochondrial respiration in diet-induced obese mice (P < 0.05) but did not improve whole-body insulin sensitivity. Importantly, the ratio of Drp1(Ser 616 ) over Drp1(Ser 637 ) phosphorylation, an indicator of mitochondrial fission, was attenuated in HFD-HIIT compared to HFD (-35.7%, P < 0.05). Regarding autophagy, skeletal muscle p62 content was lower in HFD group than LFD group (-35.1%, P < 0.05), however, such reduction was disappeared in HFD+HIIT group. In addition, LC3B II/I ratio was higher in HFD than LFD group (15.5%, P < 0.05) but was ameliorated in HFD+HIIT group (-29.9%, P < 0.05). Overall, our study demonstrated that 10 weeks of HIIT was effective in improving skeletal muscle mitochondrial respiration and the regulatory protein machinery of mitochondrial quality control in diet-induced obese mice through the alterations of mitochondrial fission protein Drp1 activity and p62/LC3B-mediated regulatory machinery of autophagy.
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6
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Compound Probiotic Ameliorates Acute Alcoholic Liver Disease in Mice by Modulating Gut Microbiota and Maintaining Intestinal Barrier. Probiotics Antimicrob Proteins 2023; 15:185-201. [PMID: 36456838 DOI: 10.1007/s12602-022-10005-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2022] [Indexed: 12/03/2022]
Abstract
Alcoholic liver disease (ALD) is a worldwide health threaten lack of effective treatment. Gut dysbiosis and concomitant augmented intestinal permeability are strongly implicated in the pathogenesis and progression of ALD. Research on the protective effect of probiotics on ALD is limited, and more effective intestinal microecological regulators and the related mechanisms still need to be further explored. In the present study, the protective effects and mechanisms of a compound probiotic against acute alcohol-induced liver injury in vivo were explod. It was showed that the compound probiotic ameliorated liver injury in acute ALD mice and stabilized the levels of ALT, AST, and TG in serum. The compound probiotic reversed acute alcohol-induced gut dysbiosis and maintained the intestinal barrier integrity by upregulating the production of mucus and the expression of tight junction (TJ) proteins and thus reduced LPS level in liver. Meanwhile, the compound probiotic reduced inflammation level by inhibiting TLR4/NF-κB signaling pathway and suppressed oxidative stress level in liver. Furthermore, the compound probiotic alleviated liver lipid accumulation by regulating fatty acid metabolism-associated genes and AMPK-PPARα signaling pathway. Noteworthy, fecal microbiota transplantation (FMT) realized comparable protective effect with that of compound probiotic. In conclusion, present study demonstrates the beneficial effects and underlying mechanism of the compound probiotic against acute alcohol-induced liver injury. It provides clues for development of novel strategy for treatment of ALD.
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Protective Effects of the Chalcone-Based Derivative AN07 on Inflammation-Associated Myotube Atrophy Induced by Lipopolysaccharide. Int J Mol Sci 2022; 23:ijms232112929. [PMID: 36361718 PMCID: PMC9655064 DOI: 10.3390/ijms232112929] [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: 10/06/2022] [Revised: 10/24/2022] [Accepted: 10/24/2022] [Indexed: 12/02/2022] Open
Abstract
Inflammation is a major cause of skeletal muscle atrophy in various diseases. 2-Hydroxy-4′-methoxychalcone (AN07) is a chalcone-based peroxisome-proliferator-activated receptor gamma (PPARγ) agonist with various effects, such as antiatherosclerosis, anti-inflammation, antioxidative stress, and neuroprotection. In this study, we examined the effects of AN07 on protein homeostasis pathway and mitochondrial function in inflammation-associated myotube atrophy induced by lipopolysaccharides (LPS). We found that AN07 significantly attenuated NF-κB activation, inflammatory factors (TNF-α, IL-1β, COX-2, and PGE2), Nox4 expression, and reactive oxygen species levels in LPS-treated C2C12 myotubes. Moreover, AN07 increased SOD2 expression and improved mitochondrial function, including mitochondrial membrane potential and mitochondrial oxygen consumption rate. We also demonstrated that AN07 attenuated LPS-induced reduction of myotube diameter, MyHC expression, and IGF-1/IGF-1R/p-Akt-mediated protein synthesis signaling. Additionally, AN07 downregulated LPS-induced autophagy–lysosomal protein degradation molecules (LC3-II/LC3-I and degraded p62) and ubiquitin–proteasome protein degradation molecules (n-FoxO1a/MuRF1/atrogin-1). However, the regulatory effects of AN07 on protein synthesis and degradation signaling were inhibited by the IGF-1R inhibitor AG1024 and the PI3K inhibitor wortmannin. In addition, the PPARγ antagonist GW9662 attenuated the effects of AN07 against LPS-induced inflammation, oxidation, and protein catabolism. In conclusion, our findings suggest that AN07 possesses protective effects on inflammation-induced myotube atrophy and mitochondrial dysfunction.
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8
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Coleman CS, Stanley BA, Lang CH. Enrichment of Newly Synthesized Proteins following treatment of C2C12 Myotubes with Endotoxin and Interferon-γ. Inflammation 2022; 45:1313-1331. [PMID: 35028803 PMCID: PMC9106851 DOI: 10.1007/s10753-022-01622-3] [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: 08/31/2021] [Revised: 12/17/2021] [Accepted: 01/04/2022] [Indexed: 11/28/2022]
Abstract
Inflammation in muscle induces the synthesis of mediators that can impair protein synthesis and enhance proteolysis, and when sustained lead to muscle atrophy. Furthermore, muscle-derived mediators that are secreted may participate in disrupting the function of other peripheral organs. Selective identification of newly synthesized proteins can provide insight on biological processes that depend on the continued synthesis of specific proteins to maintain homeostasis as well as those proteins that are up- or down-regulated in response to inflammation. We used puromycin-associated nascent chain proteomics (PUNCH-P) to characterize new protein synthesis in C2C12 myotubes and changes resulting from their exposure to the inflammatory mediators lipopolysaccharide (LPS) and interferon (IFN)-γ for either a short (4 h) or prolonged (16 h) time period. We identified sequences of nascent polypeptide chains belonging to a total of 1523 proteins and report their detection from three independent samples of each condition at each time point. The identified nascent proteins correspond to approximately 15% of presently known proteins in C2C12 myotubes and are enriched in specific cellular components and pathways. A subset of these proteins was identified only in treated samples and has functional characteristics consistent with the synthesis of specific new proteins in response to LPS/IFNγ. Thus, the identification of proteins from their nascent polypeptide chains provides a resource to analyze the role of new synthesis of proteins in both protein homeostasis and in proteome responses to stimuli in C2C12 myotubes. Our results reveal a profile of actively translating proteins for specific cellular components and biological processes in normal C2C12 myotubes and a different enrichment of proteins in response to LPS/IFNγ. Collectively, our data disclose a highly interconnected network that integrates the regulation of cellular proteostasis and reveal a diverse immune response to inflammation in muscle which may underlie the concomitantly observed atrophy and be important in inter-organ communication.
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Affiliation(s)
- Catherine S Coleman
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, 17033, USA
| | - Bruce A Stanley
- Section of Research Resources, Penn State College of Medicine, Hershey, PA, 17033, USA
| | - Charles H Lang
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, 17033, USA.
- Department of Surgery, Penn State College of Medicine, Hershey, PA, 17033, USA.
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Ducharme JB, McKenna ZJ, Deyhle MR. Exercise mitigates the Toll of muscle atrophy: A narrative review of the effects of exercise on Toll-like receptor-4 in leukocytes and skeletal muscle. Am J Physiol Cell Physiol 2022; 322:C581-C589. [PMID: 35171696 DOI: 10.1152/ajpcell.00005.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Conditions characterized by muscle wasting such as cachexia and sarcopenia are devastating at the individual level, and they place a profound burden on public health. Evidence suggests that inflammation is likely a mechanistic contributor to the pathogenesis of these conditions. One specific molecule, lipopolysaccharide, has gained attention due to its role in initiating inflammation. Toll-like receptor-4 is the primary receptor for lipopolysaccharide and has been shown to be implicit in the downstream proinflammatory response associated with lipopolysaccharide. Importantly, Toll-like receptor-4 is expressed on various cell types throughout the human body such as leukocytes and skeletal muscle fibers and may have site-specific effects that contribute to muscle wasting conditions based on the location in which activation occurs. Accordingly, reducing proinflammatory signaling at these locations may be an effective strategy at mitigating muscle wasting. Regular exercise training is believed to elicit anti-inflammatory adaptations, but the mechanisms by which this occurs are yet to be fully understood. Understanding the mechanisms by which Toll-like receptor-4 activation contributes to muscle wasting and how exercise affects this, may allow for the development of a non-pharmacological therapeutic intervention. Therefore, in this review, we summarize the current understanding of the lipopolysaccharide/Toll-like receptor-4 axis in leukocytes and skeletal muscle fibers on the pathogenesis of muscle wasting conditions and we critically examine the current evidence regarding the effects of exercise on this axis.
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Affiliation(s)
- Jeremy B Ducharme
- Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, NM, United States
| | - Zachary J McKenna
- Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, NM, United States
| | - Michael R Deyhle
- Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, NM, United States
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Kugler BA, Deng W, Duguay AL, Garcia JP, Anderson MC, Nguyen PD, Houmard JA, Zou K. Pharmacological inhibition of dynamin-related protein 1 attenuates skeletal muscle insulin resistance in obesity. Physiol Rep 2021; 9:e14808. [PMID: 33904649 PMCID: PMC8077121 DOI: 10.14814/phy2.14808] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 02/13/2021] [Indexed: 01/27/2023] Open
Abstract
Dynamin-related protein-1 (Drp1) is a key regulator in mitochondrial fission. Excessive Drp1-mediated mitochondrial fission in skeletal muscle under the obese condition is associated with impaired insulin action. However, it remains unknown whether pharmacological inhibition of Drp1, using the Drp1-specific inhibitor Mitochondrial Division Inhibitor 1 (Mdivi-1), is effective in alleviating skeletal muscle insulin resistance and improving whole-body metabolic health under the obese and insulin-resistant condition. We subjected C57BL/6J mice to a high-fat diet (HFD) or low-fat diet (LFD) for 5-weeks. HFD-fed mice received Mdivi-1 or saline injections for the last week of the diet intervention. Additionally, myotubes derived from obese insulin-resistant humans were treated with Mdivi-1 or saline for 12 h. We measured glucose area under the curve (AUC) from a glucose tolerance test (GTT), skeletal muscle insulin action, mitochondrial dynamics, respiration, and H2 O2 content. We found that Mdivi-1 attenuated impairments in skeletal muscle insulin signaling and blood glucose AUC from a GTT induced by HFD feeding (p < 0.05). H2 O2 content was elevated in skeletal muscle from the HFD group (vs. LFD, p < 0.05), but was reduced with Mdivi-1 treatment, which may partially explain the improvement in skeletal muscle insulin action. Similarly, Mdivi-1 enhanced the mitochondrial network structure, reduced reactive oxygen species, and improved insulin action in myotubes from obese humans (vs. saline, p < 0.05). In conclusion, inhibiting Drp1 with short-term Mdivi-1 administration attenuates the impairment in skeletal muscle insulin signaling and improves whole-body glucose tolerance in the setting of obesity-induced insulin resistance. Targeting Drp1 may be a viable approach to treat obesity-induced insulin resistance.
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Affiliation(s)
- Benjamin A. Kugler
- Department of Exercise and Health SciencesCollege of Nursing and Health SciencesUniversity of Massachusetts BostonBostonMAUSA
| | - Wenqian Deng
- Department of Exercise and Health SciencesCollege of Nursing and Health SciencesUniversity of Massachusetts BostonBostonMAUSA
- School of Sports Medicine and HealthChengdu Sport InstituteChengduChina
| | - Abigail L. Duguay
- Department of Exercise and Health SciencesCollege of Nursing and Health SciencesUniversity of Massachusetts BostonBostonMAUSA
| | - Jessica P. Garcia
- Department of Exercise and Health SciencesCollege of Nursing and Health SciencesUniversity of Massachusetts BostonBostonMAUSA
| | - Meaghan C. Anderson
- Department of Exercise and Health SciencesCollege of Nursing and Health SciencesUniversity of Massachusetts BostonBostonMAUSA
| | - Paul D. Nguyen
- Department of Exercise and Health SciencesCollege of Nursing and Health SciencesUniversity of Massachusetts BostonBostonMAUSA
| | - Joseph A. Houmard
- Department of KinesiologyEast Carolina UniversityGreenvilleNCUSA
- Human Performance LaboratoryEast Carolina UniversityGreenvilleNCUSA
| | - Kai Zou
- Department of Exercise and Health SciencesCollege of Nursing and Health SciencesUniversity of Massachusetts BostonBostonMAUSA
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11
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Fock EM, Parnova RG. Protective Effect of Mitochondria-Targeted Antioxidants against Inflammatory Response to Lipopolysaccharide Challenge: A Review. Pharmaceutics 2021; 13:pharmaceutics13020144. [PMID: 33499252 PMCID: PMC7910823 DOI: 10.3390/pharmaceutics13020144] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/15/2021] [Accepted: 01/17/2021] [Indexed: 12/16/2022] Open
Abstract
Lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, is the most abundant proinflammatory agent. Considerable evidence indicates that LPS challenge inescapably causes oxidative stress and mitochondrial dysfunction, leading to cell and tissue damage. Increased mitochondrial reactive oxygen species (mtROS) generation triggered by LPS is known to play a key role in the progression of the inflammatory response. mtROS at excessive levels impair electron transport chain functioning, reduce the mitochondrial membrane potential, and initiate lipid peroxidation and oxidative damage of mitochondrial proteins and mtDNA. Over the past 20 years, a large number of mitochondria-targeted antioxidants (mito-AOX) of different structures that can accumulate inside mitochondria and scavenge free radicals have been synthesized. Their protective role based on the prevention of oxidative stress and the restoration of mitochondrial function has been demonstrated in a variety of common diseases and pathological states. This paper reviews the current data on the beneficial application of different mito-AOX in animal endotoxemia models, in either in vivo or in vitro experiments. The results presented in our review demonstrate the promising potential of approaches based on mito-AOX in the development of new treatment strategies against Gram-negative infections and LPS per se.
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12
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Zhang Y, Hill GE, Ge Z, Park NR, Taylor HA, Andreasen V, Tardy L, Kavazis AN, Bonneaud C, Hood WR. Effects of a Bacterial Infection on Mitochondrial Function and Oxidative Stress in a Songbird. Physiol Biochem Zool 2021; 94:71-82. [PMID: 33399516 DOI: 10.1086/712639] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractAs a major physiological mechanism involved in cellular renewal and repair, immune function is vital to the body's capacity to support tissue maintenance and organismal survival. Because immune defenses can be energetically expensive, the activities of metabolically active organs, such as the liver, are predicted to increase during infection by most pathogens. However, some pathogens are immunosuppressive, which might reduce the metabolic capacities of select organs to suppress immune response. Mycoplasma gallisepticum (MG) is a well-known immunosuppressive bacterium that infects domestic chickens and turkeys as well as songbirds. In the house finch (Haemorhous mexicanus), which is the primary host for MG among songbird species, MG infects both the respiratory system and the conjunctiva of the eye, causing conspicuous swelling. To study the effect of a systemic bacterial infection on cellular respiration and oxidative damage in the house finch, we measured mitochondrial respiration, mitochondrial membrane potential, reactive oxygen species production, and oxidative damage in the livers of house finches that were wild caught and either infected with MG, as indicated by genetic screening for the pathogen, or free of MG infection. We observed that MG-infected house finches showed significantly lower oxidative lipid and protein damage in liver tissue compared with their uninfected counterparts. Moreover, using complex II substrates, we documented a nonsignificant trend for lower state 3 respiration of liver mitochondria in MG-infected house finches compared with uninfected house finches (P=0.07). These results are consistent with the hypothesis that MG suppresses organ function in susceptible hosts.
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13
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Massier L, Blüher M, Kovacs P, Chakaroun RM. Impaired Intestinal Barrier and Tissue Bacteria: Pathomechanisms for Metabolic Diseases. Front Endocrinol (Lausanne) 2021; 12:616506. [PMID: 33767669 PMCID: PMC7985551 DOI: 10.3389/fendo.2021.616506] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 02/02/2021] [Indexed: 02/06/2023] Open
Abstract
An intact intestinal barrier, representing the interface between inner and outer environments, is an integral regulator of health. Among several factors, bacteria and their products have been evidenced to contribute to gut barrier impairment and its increased permeability. Alterations of tight junction integrity - caused by both external factors and host metabolic state - are important for gut barrier, since they can lead to increased influx of bacteria or bacterial components (endotoxin, bacterial DNA, metabolites) into the host circulation. Increased systemic levels of bacterial endotoxins and DNA have been associated with an impaired metabolic host status, manifested in obesity, insulin resistance, and associated cardiovascular complications. Bacterial components and cells are distributed to peripheral tissues via the blood stream, possibly contributing to metabolic diseases by increasing chronic pro-inflammatory signals at both tissue and systemic levels. This response is, along with other yet unknown mechanisms, mediated by toll like receptor (TLR) transduction and increased expression of pro-inflammatory cytokines, which in turn can further increase intestinal permeability leading to a detrimental positive feedback loop. The modulation of gut barrier function through nutritional and other interventions, including manipulation of gut microbiota, may represent a potential prevention and treatment target for metabolic diseases.
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Affiliation(s)
- Lucas Massier
- Medical Department III – Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
- Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
| | - Matthias Blüher
- Medical Department III – Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München, University Hospital Leipzig, University of Leipzig, Leipzig, Germany
| | - Peter Kovacs
- Medical Department III – Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
| | - Rima M. Chakaroun
- Medical Department III – Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
- *Correspondence: Rima M. Chakaroun,
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14
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Overfeeding and Substrate Availability, But Not Age or BMI, Alter Human Satellite Cell Function. Nutrients 2020; 12:nu12082215. [PMID: 32722351 PMCID: PMC7468931 DOI: 10.3390/nu12082215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/09/2020] [Accepted: 07/21/2020] [Indexed: 12/25/2022] Open
Abstract
Satellite cells (SC) aid skeletal muscle growth and regeneration. SC-mediated skeletal muscle repair can both be influenced by and exacerbate several diseases linked to a fatty diet, obesity, and aging. The purpose of this study was to evaluate the effects of different lifestyle factors on SC function, including body mass index (BMI), age, and high-fat overfeeding. For this study, SCs were isolated from the vastus lateralis of sedentary young (18–30 years) and sedentary older (60–80 years) men with varying BMIs (18–32 kg/m2), as well as young sedentary men before and after four weeks of overfeeding (OVF) (55% fat/ + 1000 kcal, n = 4). The isolated SCs were then treated in vitro with a control (5 mM glucose, 10% fetal bovine serum (FBS)) or a high substrate growth media (HSM) (10% FBS, 25 mM glucose, and 400 μM 2:1 oleate–palmitate). Cells were assessed on their ability to proliferate, differentiate, and fuel substrate oxidation after differentiation. The effect of HSM was measured as the percentage difference between SCs exposed to HSM compared to control media. In vitro SC function was not affected by donor age. OVF reduced SC proliferation rates (–19% p < 0.05) but did not influence differentiation. Cellular proliferation in response to HSM was correlated to the donor’s body mass index (BMI) (r2 = 0.6121, p < 0.01). When exposed to HSM, SCs from normal weight (BMI 18–25 kg/m2) participants exhibited reduced proliferation and fusion rates with increased fatty-acid oxidation (p < 0.05), while SCs from participants with higher BMIs (BMI 25–32 kg/m2) demonstrated enhanced proliferation in HSM. HSM reduced proliferation and fusion (p < 0.05) in SCs isolated from subjects before OVF, whereas HSM exposure accelerated proliferation and fusion in SCs collected following OVF. These results indicated that diet has a greater influence on SC function than age and BMI. Though age and BMI do not influence in vitro SC function when grown in controlled conditions, both factors influenced the response of SCs to substrate challenges, indicating age and BMI may mediate responses to diet.
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15
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Lin HY, Weng SW, Shen FC, Chang YH, Lian WS, Hsieh CH, Chuang JH, Lin TK, Liou CW, Chang CS, Lin CY, Su YJ, Wang PW. Abrogation of Toll-Like Receptor 4 Mitigates Obesity-Induced Oxidative Stress, Proinflammation, and Insulin Resistance Through Metabolic Reprogramming of Mitochondria in Adipose Tissue. Antioxid Redox Signal 2020; 33:66-86. [PMID: 31950846 DOI: 10.1089/ars.2019.7737] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Aims: Obesity-induced excessive visceral fat (VF) accumulation is associated with insulin resistance (IR), systemic oxidative stress, and chronic inflammation. As toll-like receptor 4 (TLR4) plays an important role in innate immunity, we herein investigate the effect of TLR4 knockout (T4KO) in a high-fat high-sucrose diet (HFD)-induced obesity mouse model. Results: C57BL6 wild-type (WT) and T4KO mice were fed with either control diet (CD) or HFD for 12 months, rendering four experimental groups: WT+CD, WT+HFD, T4KO+CD, and T4KO+HFD. Compared with WT+CD, WT+HFD demonstrated significant increase in VF accumulation, oxidative damage, M1/M2 macrophage ratio, chronic inflammation, and development of IR. Compared with WT+HFD, T4KO+HFD presented increased BW and body fat with higher subcutaneous fat (SF)/VF ratio, but lower body temperature, as well as decreased oxidative damage, M1/M2 macrophage ratio, chronic inflammation, and IR. Unlike WT+HFD, T4KO+HFD exhibited an increase in mitochondrial electron transport chain activity but a decrease of uncoupling protein 2 (UCP2) level. While T4KO hindered HFD-induced increasing mitochondrial oxygen consumption rate, a shift toward a higher extracellular acidification rate in VF was observed. Notably, T4KO inhibits HFD-induced mitochondrial translocation of nuclear factor of activated T cells 2 (NFATC2), which contributed to mitochondrial metabolic reprogramming. Both fat distribution shifting from VF to SF and mitochondrial metabolic reprogramming may alleviate systemic oxidative stress and chronic inflammation. Innovation and Conclusion: Abrogation of TLR4 contributes to reduction of oxidative stress through metabolic reprogramming of mitochondria in VF, mitigating obesity-induced IR. The study provides critical insight into associating innate immunity-mitochondria interplay with prevention of diabetes.
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Affiliation(s)
- Hung-Yu Lin
- Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Center for Mitochondrial Research and Medicine; Departments of Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Shao-Wen Weng
- Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Feng-Chih Shen
- Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Yen-Hsiang Chang
- Nuclear Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Wei-Shiung Lian
- Medical Research and Core Laboratory for Phenomics and Diagnostics, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Pediatrics, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Ching-Hua Hsieh
- Plastic and Reconstructive Surgery, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Jiin-Haur Chuang
- Center for Mitochondrial Research and Medicine; Departments of Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Pediatric Surgery, and Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Tsu-Kung Lin
- Center for Mitochondrial Research and Medicine; Departments of Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Chia-Wei Liou
- Center for Mitochondrial Research and Medicine; Departments of Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Chia-Shiang Chang
- Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Center for Mitochondrial Research and Medicine; Departments of Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Ching-Yi Lin
- Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Center for Mitochondrial Research and Medicine; Departments of Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Yu-Jih Su
- Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Pei-Wen Wang
- Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Center for Mitochondrial Research and Medicine; Departments of Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
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16
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El-Houjeiri L, Possik E, Vijayaraghavan T, Paquette M, Martina JA, Kazan JM, Ma EH, Jones R, Blanchette P, Puertollano R, Pause A. The Transcription Factors TFEB and TFE3 Link the FLCN-AMPK Signaling Axis to Innate Immune Response and Pathogen Resistance. Cell Rep 2020; 26:3613-3628.e6. [PMID: 30917316 DOI: 10.1016/j.celrep.2019.02.102] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 10/22/2018] [Accepted: 02/25/2019] [Indexed: 12/11/2022] Open
Abstract
TFEB and TFE3 are transcriptional regulators of the innate immune response, but the mechanisms regulating their activation upon pathogen infection are poorly elucidated. Using C. elegans and mammalian models, we report that the master metabolic modulator 5'-AMP-activated protein kinase (AMPK) and its negative regulator Folliculin (FLCN) act upstream of TFEB/TFE3 in the innate immune response, independently of the mTORC1 signaling pathway. In nematodes, loss of FLCN or overexpression of AMPK confers pathogen resistance via activation of TFEB/TFE3-dependent antimicrobial genes, whereas ablation of total AMPK activity abolishes this phenotype. Similarly, in mammalian cells, loss of FLCN or pharmacological activation of AMPK induces TFEB/TFE3-dependent pro-inflammatory cytokine expression. Importantly, a rapid reduction in cellular ATP levels in murine macrophages is observed upon lipopolysaccharide (LPS) treatment accompanied by an acute AMPK activation and TFEB nuclear localization. These results uncover an ancient, highly conserved, and pharmacologically actionable mechanism coupling energy status with innate immunity.
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Affiliation(s)
- Leeanna El-Houjeiri
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Elite Possik
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Tarika Vijayaraghavan
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Mathieu Paquette
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - José A Martina
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - Jalal M Kazan
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Eric H Ma
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Physiology, McGill University, Montréal, QC, Canada
| | - Russell Jones
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Physiology, McGill University, Montréal, QC, Canada
| | - Paola Blanchette
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Rosa Puertollano
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - Arnim Pause
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada.
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17
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Eskilsson A, Shionoya K, Enerbäck S, Engblom D, Blomqvist A. The generation of immune-induced fever and emotional stress-induced hyperthermia in mice does not involve brown adipose tissue thermogenesis. FASEB J 2020; 34:5863-5876. [PMID: 32144818 DOI: 10.1096/fj.201902945r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 02/19/2020] [Accepted: 02/22/2020] [Indexed: 11/11/2022]
Abstract
We examined the role of brown adipose tissue (BAT) for fever and emotional stress-induced hyperthermia. Wild-type and uncoupling protein-1 (UCP-1) knockout mice were injected with lipopolysaccharide intraperitoneally or intravenously, or subjected to cage exchange, and body temperature monitored by telemetry. Both genotypes showed similar febrile responses to immune challenge and both displayed hyperthermia to emotional stress. Neither procedure resulted in the activation of BAT, such as the induction of UCP-1 or peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) mRNA, or reduced BAT weight and triglyceride content. In contrast, in mice injected with a β3 agonist, UCP-1 and PGC-1α were strongly induced, and BAT weight and triglyceride content reduced. Both lipopolysaccharide and the β3 agonist, and emotional stress, induced UCP-3 mRNA in skeletal muscle. A β3 antagonist did not attenuate lipopolysaccharide-induced fever, but augmented body temperature decrease and inhibited BAT activation when mice were exposed to cold. An α1 /α2b antagonist or a 5HT1A agonist, which inhibit vasoconstriction, abolished lipopolysaccharide-induced fever, but had no effect on emotional stress-induced hyperthermia. These findings demonstrate that in mice, UCP-1-mediated BAT thermogenesis does not take part in inflammation-induced fever, which is dependent on peripheral vasoconstriction, nor in stress-induced hyperthermia. However, both phenomena may involve UCP-3-mediated muscle thermogenesis.
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Affiliation(s)
- Anna Eskilsson
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Kiseko Shionoya
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Sven Enerbäck
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - David Engblom
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Anders Blomqvist
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
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18
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Bowser SM, McMillan RP, Boutagy NE, Tarpey MD, Smithson AT, Osterberg KL, Neilson AP, Davy BM, Davy KP, Hulver MW. Serum endotoxin, gut permeability and skeletal muscle metabolic adaptations following a short term high fat diet in humans. Metabolism 2020; 103:154041. [PMID: 31785256 DOI: 10.1016/j.metabol.2019.154041] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 10/24/2019] [Accepted: 11/22/2019] [Indexed: 01/10/2023]
Abstract
BACKGROUND Our previous work demonstrated that a short-term high fat diet (HFD) increased fasting serum endotoxin, altered postprandial excursions of serum endotoxin, and led to metabolic and transcriptional responses in skeletal muscle in young, healthy male humans. PURPOSE The purpose of the present study was to determine if a short-term high fat diet: 1) increases intestinal permeability and, in turn, fasting endotoxin concentrations and 2) decreases postprandial skeletal muscle fat oxidation. METHODS Thirteen normal weight young adult males (BMI 23.1 ± 0.8 kg/m2, age 22.2 ± 0.4 years) were fed a control diet (55% carbohydrate, 30% fat, 9% of which was saturated, 15% protein) for two weeks, followed by 5 days of an isocaloric HFD (30% carbohydrate, 55% fat, 25% of which was saturated, 15% protein, isocaloric to the control diet). Intestinal permeability (via four sugar probe test) was assessed in the fasting state. Both before and after the HFD, a high fat meal challenge (HFM, 820 kcal, 25% carbohydrate, 63% fat, 26% of which was saturated, and 12% protein) was administered. After an overnight fast, blood samples were collected before and every hour for 4 h after the HFM to assess endotoxin, and other serum blood measures. Muscle biopsies were obtained from the vastus lateralis before and 4 h after the HFM in order to assess substrate oxidation (glucose, fatty acid and pyruvate) using radiolabeled techniques. Insulin sensitivity was assessed via intravenous glucose tolerance test. Intestinal permeability, blood samples and muscle biopsies were assessed in the same manner before and following the HFD. MAIN FINDINGS Intestinal permeability was not affected by HFD (p > 0.05), but fasting endotoxin increased two fold following the HFD (p = 0.04). Glucose oxidation and fatty acid oxidation in skeletal muscle homogenates significantly increased after the HFM before the HFD (+97%, and +106% respectively) but declined after the HFM following 5 days of the HFD (-24% and +16% respectively). Fatty acid suppressibility of pyruvate oxidation increased significantly after the HFM (+32%) but this physiological effect was abolished following 5 days of the HFD (+7%). Insulin sensitivity did not change following the HFD. CONCLUSION These findings demonstrate that in healthy young men, consuming an isocaloric HFD for 5 days increases fasting endotoxin, independent of changes in gut permeability. These changes in endotoxin are accompanied by a broad effect on skeletal muscle substrate metabolism including increases in postprandial fat oxidation. Importantly, the latter occurs independent of changes in body weight and whole-body insulin sensitivity.
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Affiliation(s)
- Suzanne M Bowser
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, 338 Wallace Hall, 295 West Campus Drive, Blacksburg, VA 24061, USA.
| | - Ryan P McMillan
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, 338 Wallace Hall, 295 West Campus Drive, Blacksburg, VA 24061, USA; Virginia Tech Metabolic Phenotyping Core Facility, Integrated Life Science Building, 1981 Kraft Drive, Blacksburg, VA 24060, USA.
| | - Nabil E Boutagy
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, 338 Wallace Hall, 295 West Campus Drive, Blacksburg, VA 24061, USA.
| | - Michael D Tarpey
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, 338 Wallace Hall, 295 West Campus Drive, Blacksburg, VA 24061, USA.
| | - Andrew T Smithson
- Department of Food Science and Technology, Virginia Tech, Food Science Building (0418), 360 Duck Pond Drive, Blacksburg, VA 24060, USA.
| | - Kristin L Osterberg
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, 338 Wallace Hall, 295 West Campus Drive, Blacksburg, VA 24061, USA.
| | - Andrew P Neilson
- Department of Food Science and Technology, Virginia Tech, Food Science Building (0418), 360 Duck Pond Drive, Blacksburg, VA 24060, USA.
| | - Brenda M Davy
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, 338 Wallace Hall, 295 West Campus Drive, Blacksburg, VA 24061, USA.
| | - Kevin P Davy
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, 338 Wallace Hall, 295 West Campus Drive, Blacksburg, VA 24061, USA.
| | - Matthew W Hulver
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, 338 Wallace Hall, 295 West Campus Drive, Blacksburg, VA 24061, USA; Virginia Tech Metabolic Phenotyping Core Facility, Integrated Life Science Building, 1981 Kraft Drive, Blacksburg, VA 24060, USA.
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19
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Cadaret CN, Merrick EM, Barnes TL, Beede KA, Posont RJ, Petersen JL, Yates DT. Sustained maternal inflammation during the early third-trimester yields intrauterine growth restriction, impaired skeletal muscle glucose metabolism, and diminished β-cell function in fetal sheep1,2. J Anim Sci 2019; 97:4822-4833. [PMID: 31616931 PMCID: PMC6915216 DOI: 10.1093/jas/skz321] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 10/08/2019] [Indexed: 12/15/2022] Open
Abstract
Maternal inflammation causes fetal intrauterine growth restriction (IUGR), but its impact on fetal metabolism is not known. Thus, our objective was to determine the impact of sustained maternal inflammation in late gestation on fetal inflammation, skeletal muscle glucose metabolism, and insulin secretion. Pregnant ewes were injected every third day from the 100th to 112th day of gestation (term = 150 d) with saline (controls) or lipopolysaccharide (LPS) to induce maternal inflammation and IUGR (MI-IUGR). Fetal femoral blood vessels were catheterized on day 118 to assess β-cell function on day 123, hindlimb glucose metabolic rates on day 124, and daily blood parameters from days 120 to 125. Fetal muscle was isolated on day 125 to assess ex vivo glucose metabolism. Injection of LPS increased (P < 0.05) rectal temperatures, circulating white blood cells, and plasma tumor necrosis factor α (TNFα) concentrations in MI-IUGR ewes. Maternal leukocytes remained elevated (P < 0.05) and TNFα tended to remain elevated (P < 0.10) compared with controls almost 2 wk after the final LPS injection. Total white blood cells, monocytes, granulocytes, and TNFα were also greater (P < 0.05) in MI-IUGR fetuses than controls over this period. MI-IUGR fetuses had reduced (P < 0.05) blood O2 partial pressures and greater (P < 0.05) maternofetal O2 gradients, but blood glucose and maternofetal glucose gradients did not differ from controls. Basal and glucose-stimulated insulin secretion were reduced (P < 0.05) by 32% and 42%, respectively, in MI-IUGR fetuses. In vivo hindlimb glucose oxidation did not differ between groups under resting conditions but was 47% less (P < 0.05) in MI-IUGR fetuses than controls during hyperinsulinemia. Hindlimb glucose utilization did not differ between fetal groups. At day 125, MI-IUGR fetuses were 22% lighter (P < 0.05) than controls and tended to have greater (P < 0.10) brain/BW ratios. Ex vivo skeletal muscle glucose oxidation did not differ between groups in basal media but was less (P < 0.05) for MI-IUGR fetuses in insulin-spiked media. Glucose uptake rates and phosphorylated-to-total Akt ratios were less (P < 0.05) in muscle from MI-IUGR fetuses than controls regardless of media. We conclude that maternal inflammation leads to fetal inflammation, reduced β-cell function, and impaired skeletal muscle glucose metabolism that persists after maternal inflammation ceases. Moreover, fetal inflammation may represent a target for improving metabolic dysfunction in IUGR fetuses.
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Affiliation(s)
- Caitlin N Cadaret
- Department of Animal Science, University of Nebraska–Lincoln, Lincoln, NE
| | - Elena M Merrick
- Department of Animal Science, University of Nebraska–Lincoln, Lincoln, NE
| | - Taylor L Barnes
- Department of Animal Science, University of Nebraska–Lincoln, Lincoln, NE
| | - Kristin A Beede
- Department of Animal Science, University of Nebraska–Lincoln, Lincoln, NE
| | - Robert J Posont
- Department of Animal Science, University of Nebraska–Lincoln, Lincoln, NE
| | - Jessica L Petersen
- Department of Animal Science, University of Nebraska–Lincoln, Lincoln, NE
| | - Dustin T Yates
- Department of Animal Science, University of Nebraska–Lincoln, Lincoln, NE
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20
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Silva KAS, Ghiarone T, Schreiber K, Grant D, White T, Frisard MI, Sukhanov S, Chandrasekar B, Delafontaine P, Yoshida T. Angiotensin II suppresses autophagy and disrupts ultrastructural morphology and function of mitochondria in mouse skeletal muscle. J Appl Physiol (1985) 2019; 126:1550-1562. [PMID: 30946636 DOI: 10.1152/japplphysiol.00898.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Angiotensin II (ANG II)-induced skeletal muscle wasting is characterized by activation of the ubiquitin-proteasome system. However, the potential involvement of proteolytic system macroautophagy/autophagy in this wasting process remains elusive. Autophagy is precisely regulated to maintain cell survival and homeostasis; thus its dysregulation (i.e., overactivation or persistent suppression) could lead to detrimental outcomes in skeletal muscle. Here we show that infusion of ANG II for 7 days in male FVB mice suppressed autophagy in skeletal muscle. ANG II blunted microtubule-associated protein 1 light chain 3B (LC3B)-I-to-LC3B-II conversion (an autophagosome marker), increased p62/SQSTM1 (an autophagy cargo receptor) protein expression, and decreased the number of autophagic vacuoles. ANG II inhibited UNC-51-like kinase 1 via inhibition of 5'-AMP-activated kinase and activation of mechanistic target of rapamycin complex 1, leading to reduced phosphorylation of beclin-1Ser14 and Autophagy-related protein 14Ser29, suggesting that ANG II impairs autophagosome formation in skeletal muscle. In line with ANG II-mediated suppression of autophagy, ANG II promoted accumulation of abnormal/damaged mitochondria, characterized by swelling and disorganized cristae and matrix dissolution, with associated increase in PTEN-induced kinase 1 protein expression. ANG II also reduced mitochondrial respiration, indicative of mitochondrial dysfunction. Together, these results demonstrate that ANG II reduces autophagic activity and disrupts mitochondrial ultrastructure and function, likely contributing to skeletal muscle wasting. Therefore, strategies that activate autophagy in skeletal muscle have the potential to prevent or blunt ANG II-induced skeletal muscle wasting in chronic diseases. NEW & NOTEWORTHY Our study identified a novel mechanism whereby angiotensin II (ANG II) impairs mitochondrial energy metabolism in skeletal muscle. ANG II suppressed autophagosome formation by inhibiting the UNC-51-like kinase 1(ULK1)-beclin-1 axis, resulting in accumulation of abnormal/damaged and dysfunctional mitochondria and reduced mitochondrial respiratory capacity. Therapeutic strategies that activate the ULK1-beclin-1 axis have the potential to delay or reverse skeletal muscle wasting in chronic diseases characterized by increased systemic ANG II levels.
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Affiliation(s)
| | - Thaysa Ghiarone
- Dalton Cardiovascular Research Center, University of Missouri , Columbia, Missouri
| | - Kathy Schreiber
- Cell and Immunobiology Core, University of Missouri , Columbia, Missouri
| | - DeAna Grant
- Electron Microcopy Core Facility, University of Missouri , Columbia, Missouri
| | - Tommi White
- Electron Microcopy Core Facility, University of Missouri , Columbia, Missouri.,Department of Biochemistry, University of Missouri , Columbia, Missouri
| | - Madlyn I Frisard
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia
| | - Sergiy Sukhanov
- Department of Medicine, University of Missouri School of Medicine, Columbia, Missouri.,Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine , Columbia, Missouri
| | - Bysani Chandrasekar
- Department of Medicine, University of Missouri School of Medicine, Columbia, Missouri.,Dalton Cardiovascular Research Center, University of Missouri , Columbia, Missouri.,Research Service, Harry S. Truman Memorial Veterans' Hospital , Columbia, Missouri.,Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine , Columbia, Missouri
| | - Patrice Delafontaine
- Department of Medicine, University of Missouri School of Medicine, Columbia, Missouri.,Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine , Columbia, Missouri
| | - Tadashi Yoshida
- Department of Medicine, University of Missouri School of Medicine, Columbia, Missouri.,Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine , Columbia, Missouri
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21
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Samokhvalov V, Jamieson KL, Darwesh AM, Keshavarz-Bahaghighat H, Lee TYT, Edin M, Lih F, Zeldin DC, Seubert JM. Deficiency of Soluble Epoxide Hydrolase Protects Cardiac Function Impaired by LPS-Induced Acute Inflammation. Front Pharmacol 2019; 9:1572. [PMID: 30692927 PMCID: PMC6339940 DOI: 10.3389/fphar.2018.01572] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 12/24/2018] [Indexed: 12/14/2022] Open
Abstract
Lipopolysaccharide (LPS) is a bacterial wall endotoxin producing many pathophysiological conditions including myocardial inflammation leading to cardiotoxicity. Linoleic acid (18:2n6, LA) is an essential n-6 PUFA which is converted to arachidonic acid (20:4n6, AA) by desaturation and elongation via enzyme systems within the body. Biological transformation of PUFA through CYP-mediated hydroxylation, epoxidation, and allylic oxidation produces lipid mediators, which may be subsequently hydrolyzed to corresponding diol metabolites by soluble epoxide hydrolase (sEH). In the current study, we investigate whether inhibition of sEH, which alters the PUFA metabolite profile, can influence LPS induced cardiotoxicity and mitochondrial function. Our data demonstrate that deletion of soluble epoxide hydrolase provides protective effects against LPS-induced cardiotoxicity by maintaining mitochondrial function. There was a marked alteration in the cardiac metabolite profile with notable increases in sEH-derived vicinal diols, 9,10- and 12,13-dihydroxyoctadecenoic acid (DiHOME) in WT hearts following LPS administration, which was absent in sEH null mice. We found that DiHOMEs triggered pronounced mitochondrial structural abnormalities, which also contributed to the development of extensive mitochondrial dysfunction in cardiac cells. Accumulation of DiHOMEs may represent an intermediate mechanism through which LPS-induced acute inflammation triggers deleterious alterations in the myocardium in vivo and cardiac cells in vitro. This study reveals novel research exploring the contribution of DiHOMEs in the progression of adverse inflammatory responses toward cardiac function in vitro and in vivo.
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Affiliation(s)
- Victor Samokhvalov
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - K Lockhart Jamieson
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Ahmed M Darwesh
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | | | - Tim Y T Lee
- Department of Pharmacology, Faculty of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Matthew Edin
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, United States
| | - Fred Lih
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, United States
| | - Darryl C Zeldin
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, United States
| | - John M Seubert
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Department of Pharmacology, Faculty of Medicine, University of Alberta, Edmonton, AB, Canada
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22
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Nair S, Sobotka KS, Joshi P, Gressens P, Fleiss B, Thornton C, Mallard C, Hagberg H. Lipopolysaccharide-induced alteration of mitochondrial morphology induces a metabolic shift in microglia modulating the inflammatory response in vitro and in vivo. Glia 2019; 67:1047-1061. [PMID: 30637805 DOI: 10.1002/glia.23587] [Citation(s) in RCA: 140] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 12/21/2018] [Accepted: 12/21/2018] [Indexed: 12/18/2022]
Abstract
Accumulating evidence suggests that changes in the metabolic signature of microglia underlie their response to inflammation. We sought to increase our knowledge of how pro-inflammatory stimuli induce metabolic changes. Primary microglia exposed to lipopolysaccharide (LPS)-expressed excessive fission leading to more fragmented mitochondria than tubular mitochondria. LPS-mediated Toll-like receptor 4 (TLR4) activation also resulted in metabolic reprogramming from oxidative phosphorylation to glycolysis. Blockade of mitochondrial fission by Mdivi-1, a putative mitochondrial division inhibitor led to the reversal of the metabolic shift. Mdivi-1 treatment also normalized the changes caused by LPS exposure, namely an increase in mitochondrial reactive oxygen species production and mitochondrial membrane potential as well as accumulation of key metabolic intermediate of TCA cycle succinate. Moreover, Mdivi-1 treatment substantially reduced LPS induced cytokine and chemokine production. Finally, we showed that Mdivi-1 treatment attenuated expression of genes related to cytotoxic, repair, and immunomodulatory microglia phenotypes in an in vivo neuroinflammation paradigm. Collectively, our data show that the activation of microglia to a classically pro-inflammatory state is associated with a switch to glycolysis that is mediated by mitochondrial fission, a process which may be a pharmacological target for immunomodulation.
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Affiliation(s)
- Syam Nair
- Centre of Perinatal Medicine and Health, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Kristina S Sobotka
- Centre of Perinatal Medicine and Health, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Pooja Joshi
- PROTECT, INSERM, Université Paris Diderot, Paris, France
| | - Pierre Gressens
- PROTECT, INSERM, Université Paris Diderot, Paris, France
- Centre for the Developing Brain, Department of Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
| | - Bobbi Fleiss
- PROTECT, INSERM, Université Paris Diderot, Paris, France
- Centre for the Developing Brain, Department of Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Claire Thornton
- Centre for the Developing Brain, Department of Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
| | - Carina Mallard
- Centre of Perinatal Medicine and Health, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Henrik Hagberg
- Centre of Perinatal Medicine and Health, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Centre for the Developing Brain, Department of Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
- Institute of Clinical Sciences, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Khalil R. Ubiquitin-Proteasome Pathway and Muscle Atrophy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1088:235-248. [DOI: 10.1007/978-981-13-1435-3_10] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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24
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Chen Y, Ouyang X, Hoque R, Garcia-Martinez I, Yousaf MN, Tonack S, Offermanns S, Dubuquoy L, Louvet A, Mathurin P, Massey V, Schnabl B, Bataller RA, Mehal WZ. β-Hydroxybutyrate protects from alcohol-induced liver injury via a Hcar2-cAMP dependent pathway. J Hepatol 2018; 69:687-696. [PMID: 29705237 PMCID: PMC6098974 DOI: 10.1016/j.jhep.2018.04.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 04/03/2018] [Accepted: 04/04/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Sterile inflammation resulting in alcoholic hepatitis (AH) occurs unpredictably after many years of excess alcohol intake. The factors responsible for the development of AH are not known but mitochondrial damage with loss of mitochondrial function are common features. Hcar2 is a G-protein coupled receptor which is activated by β-hydroxybutyrate (BHB). We aimed to determine the relevance of the BHB-Hcar2 pathway in alcoholic liver disease. METHODS We tested if loss of BHB production can result in increased liver inflammation. We further tested if BHB supplementation is protective in AH through interaction with Hcar2, and analyzed the immune and cellular basis for protection. RESULTS Humans with AH have reduced hepatic BHB, and inhibition of BHB production in mice aggravated ethanol-induced AH, with higher plasma alanine aminotransferase levels, increased steatosis and greater neutrophil influx. Conversely supplementation of BHB had the opposite effects with reduced alanine aminotransferase levels, reduced steatosis and neutrophil influx. This therapeutic effect of BHB is dependent on the receptor Hcar2. BHB treatment increased liver Il10 transcripts, and promoted the M2 phenotype of intrahepatic macrophages. BHB also increased the transcriptional level of M2 related genes in vitro bone marrow derived macrophages. This skewing towards M2 related genes is dependent on lower mitochondrial membrane potential (Δψ) induced by BHB. CONCLUSIONS Collectively, our data shows that BHB production during excess alcohol consumption has an anti-inflammatory and hepatoprotective role through an Hcar2 dependent pathway. This introduces the concept of metabolite-based therapy for AH. LAY SUMMARY Alcoholic hepatitis is a life-threatening condition with no approved therapy that occurs unexpectedly in people who consume excess alcohol. The liver makes many metabolites, and we demonstrate that loss of one such metabolite β-hydroxybutyrate occurs in patients with alcoholic hepatitis. This loss can increase alcohol-induced liver injury, and β-hydroxybutyrate can protect from alcohol-induced liver injury via a receptor on liver macrophages. This opens the possibility of metabolite-based therapy for alcoholic hepatitis.
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Affiliation(s)
- Yonglin Chen
- Section of Digestive Diseases, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Xinshou Ouyang
- Section of Digestive Diseases, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Rafaz Hoque
- Section of Digestive Diseases, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Irma Garcia-Martinez
- Section of Digestive Diseases, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Muhammad Nadeem Yousaf
- Section of Digestive Diseases, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Sarah Tonack
- Max-Planck-Institute for Heart and Lung Research, Department of Pharmacology, Ludwigstr. 43, 61231 Bad Nauheim, Germany; Medical Faculty, J.W. Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - Stefan Offermanns
- Max-Planck-Institute for Heart and Lung Research, Department of Pharmacology, Ludwigstr. 43, 61231 Bad Nauheim, Germany; Medical Faculty, J.W. Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | | | - Alexandre Louvet
- Service des Maladies de l'appareil digestif, Hôpital Huriez, Lille, France; Unité INSERM 995, Faculté de Médecine, Lille, France
| | - Philippe Mathurin
- Service des Maladies de l'appareil digestif, Hôpital Huriez, Lille, France; Unité INSERM 995, Faculté de Médecine, Lille, France
| | - Veronica Massey
- School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Bernd Schnabl
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Ramon Alberola Bataller
- Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Wajahat Zafar Mehal
- Section of Digestive Diseases, Yale University School of Medicine, New Haven, CT 06520, USA; USA West Haven Veterans Medical Center, West Haven, CT 06516, USA.
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25
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Tian Z, Chen Y, Yao N, Hu C, Wu Y, Guo D, Liu J, Yang Y, Chen T, Zhao Y, He Y. Role of mitophagy regulation by ROS in hepatic stellate cells during acute liver failure. Am J Physiol Gastrointest Liver Physiol 2018; 315:G374-G384. [PMID: 29648877 DOI: 10.1152/ajpgi.00032.2018] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Liver sinusoids serve as the first line of defense against extrahepatic stimuli from the intestinal tract. Hepatic stellate cells (HSCs) are pericytes residing in the perisinusoidal space that integrate cytokine-mediated inflammatory responses in the sinusoids and relay these signals to the liver parenchyma. Oxidative stress has been shown to promote inflammation during acute liver failure (ALF). Whether and how oxidative stress is involved in HSC inflammation during ALF remains unclear. Level of systemic oxidative stress is reflected by superoxide dismutase (SOD). Thus, ALF patients were recruited to investigate the correlation between plasma SOD levels and clinical features. Liver tissues were collected from chronic hepatitis patients by biopsy and from ALF patients who had undergone liver transplantation. SOD2 expression and HSCs activation were investigated by immunohistochemistry. Inflammation, mitophagy, and apoptosis were investigated by immunoblot analysis and flow cytometry in HSCs treated with lipopolysaccharide (LPS) and reactive oxygen species (ROS) donors. The plasma SOD level was significantly increased in patients with ALF compared with those with cirrhosis (444.4 ± 23.58 vs. 170.07 ± 3.52 U/ml, P < 0.01) and was positively correlated with the Model for End-Stage Liver Disease-Na score ( R2 = 0.4720, P < 0.01). In vivo observations revealed that SOD2 immunostaining was increased in ALF patients and mice models, and in vitro experiments demonstrated that LPS/ROS promoted inflammation via inhibiting mitophagy. Moreover, the regulation of inflammation was apoptosis independent in HSCs. LPS-induced increases in oxidative stress promote inflammation through inhibiting mitophagy in HSCs during the process of ALF, providing a novel strategy for the treatment of patients with ALF. NEW & NOTEWORTHY Here we demonstrate that the serum superoxide dismutase (SOD) level is significantly increased in patients with acute liver failure (ALF), and, correlated with the Model for End-Stage Liver Disease-Na score, SOD level dropped in the remission stage of ALF. We identify that, in liver tissue from ALF patients and mice models, manganese-dependent SOD was overexpressed, and show lipopolysaccharide/H2O2 inhibits mitophagy via reactive oxygen species in hepatic stellate cells (HSCs). We show that inhibited mitophagy promotes inflammation in HSCs, whereas mitophagy inducer rescues HSCs from lipopolysaccharide-induced inflammation.
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Affiliation(s)
- Zhen Tian
- Department of Infectious Diseases, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China.,Institution of Hepatology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Yi Chen
- Department of Infectious Diseases, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China.,Institution of Hepatology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Naijuan Yao
- Department of Infectious Diseases, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China.,Institution of Hepatology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Chunhua Hu
- Department of Infectious Diseases, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China.,Institution of Hepatology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Yuchao Wu
- Department of Infectious Diseases, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China.,Institution of Hepatology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Dandan Guo
- Department of Infectious Diseases, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China.,Institution of Hepatology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Jinfeng Liu
- Department of Infectious Diseases, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China.,Institution of Hepatology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Yuan Yang
- Department of Infectious Diseases, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China.,Institution of Hepatology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Tianyan Chen
- Department of Infectious Diseases, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China.,Institution of Hepatology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Yingren Zhao
- Department of Infectious Diseases, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China.,Institution of Hepatology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Yingli He
- Department of Infectious Diseases, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China.,Institution of Hepatology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
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Nieman DC, Gillitt ND, Sha W, Esposito D, Ramamoorthy S. Metabolic recovery from heavy exertion following banana compared to sugar beverage or water only ingestion: A randomized, crossover trial. PLoS One 2018; 13:e0194843. [PMID: 29566095 PMCID: PMC5864065 DOI: 10.1371/journal.pone.0194843] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 02/21/2018] [Indexed: 11/18/2022] Open
Abstract
Objectives and methods Using a randomized, crossover, counterbalanced approach, cyclists (N = 20, overnight fasted state) engaged in the four 75-km time trials (2-week washout) while ingesting two types of bananas with similar carbohydrate (CHO) but different phenolic content (Cavendish, CAV; mini-yellow, MIY, 63% higher polyphenols), a 6% sugar beverage (SUG), and water only (WAT). CHO intake was set at 0.2 g/kg every 15 minutes. Blood samples were collected pre-exercise and 0 h-, 0.75 h-,1.5 h-, 3 h-, 4.5 h-, 21 h-, 45 h-post-exercise. Results Each of the CHO trials (CAV, MIY, SUG) compared to water was associated with higher post-exercise plasma glucose and fructose, and lower leukocyte counts, plasma 9+13 HODES, and IL-6, IL-10, and IL-1ra. OPLS-DA analysis showed that metabolic perturbation (N = 1,605 metabolites) for WAT (86.8±4.0 arbitrary units) was significantly greater and sustained than for CAV (70.4±3.9, P = 0.006), MIY (68.3±4.0, P = 0.002), and SUG (68.1±4.2, P = 0.002). VIP ranking (<3.0, N = 25 metabolites) showed that both CAV and MIY were associated with significant fold changes in metabolites including those from amino acid and xenobiotics pathways. OPLS-DA analysis of immediate post-exercise metabolite shifts showed a significant separation of CAV and MIY from both WAT and SUG (R2Y = 0.848, Q2Y = 0.409). COX-2 mRNA expression was lower in both CAV and MIY, but not SUG, versus WAT at 21-h post-exercise in THP-1 monocytes cultured in plasma samples. Analysis of immediate post-exercise samples showed a decrease in LPS-stimulated THP-1 monocyte extracellular acidification rate (ECAR) in CAV and MIY, but not SUG, compared to WAT. Conclusions CHO ingestion from bananas or a sugar beverage had a comparable influence in attenuating metabolic perturbation and inflammation following 75-km cycling. Ex-vivo analysis with THP-1 monocytes supported a decrease in COX-2 mRNA expression and reduced reliance on glycolysis for ATP production following ingestion of bananas but not sugar water when compared to water alone. Trial registration ClinicalTrials.gov, U.S. National Institutes of Health, identifier: NCT02994628
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Affiliation(s)
- David C. Nieman
- Human Performance Laboratory, Appalachian State University, North Carolina Research Campus, Kannapolis, North Carolina, United States of America
- * E-mail:
| | - Nicholas D. Gillitt
- Dole Nutrition Research Laboratory, North Carolina Research Campus, Kannapolis, North Carolina, United States of America
| | - Wei Sha
- Bioinformatics Services Division, University of North Carolina at Charlotte, North Carolina Research Campus, Kannapolis, North Carolina, United States of America
| | - Debora Esposito
- Plants for Human Health Institute, North Carolina State University, North Carolina Research Campus, Kannapolis, North Carolina, United States of America
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Sepsis-Induced Cardiomyopathy: Oxidative Implications in the Initiation and Resolution of the Damage. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:7393525. [PMID: 29057035 PMCID: PMC5625757 DOI: 10.1155/2017/7393525] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 07/14/2017] [Accepted: 08/23/2017] [Indexed: 12/13/2022]
Abstract
Cardiac dysfunction may complicate the course of severe sepsis and septic shock with significant implications for patient's survival. The basic pathophysiologic mechanisms leading to septic cardiomyopathy have not been fully clarified until now. Disease-specific treatment is lacking, and care is still based on supportive modalities. Septic state causes destruction of redox balance in many cell types, cardiomyocytes included. The production of reactive oxygen and nitrogen species is increased, and natural antioxidant systems fail to counterbalance the overwhelming generation of free radicals. Reactive species interfere with many basic cell functions, mainly through destruction of protein, lipid, and nucleic acid integrity, compromising enzyme function, mitochondrial structure and performance, and intracellular signaling, all leading to cardiac contractile failure. Takotsubo cardiomyopathy may result from oxidative imbalance. This review will address the multiple aspects of cardiomyocyte bioenergetic failure in sepsis and discuss potential therapeutic interventions.
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28
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Glutamate alleviates muscle protein loss by modulating TLR4, NODs, Akt/FOXO and mTOR signaling pathways in LPS-challenged piglets. PLoS One 2017; 12:e0182246. [PMID: 28783736 PMCID: PMC5544224 DOI: 10.1371/journal.pone.0182246] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 07/14/2017] [Indexed: 12/25/2022] Open
Abstract
The experiment was conducted to study the effect of the glutamate (Glu) on muscle protein loss through toll-like receptor 4 (TLR4), nucleotide-binding oligomerization domain proteins (NODs), Akt/Forkhead Box O (Akt/FOXO) and mammalian target of rapamycin (mTOR) signaling pathways in LPS-challenged piglets. Twenty-four weaned piglets were assigned into four treatments: (1) Control; (2) LPS+0% Glu; (3) LPS + 1.0% Glu; (4) LPS + 2.0% Glu. The experiment was lasted for 28 days. On d 28, the piglets in the LPS challenged groups were injected with LPS on 100 μg/kg body weight (BW), and the piglets in the control group were injected with the same volume of 0.9% NaCl solution. After 4 h LPS or saline injection, the piglets were slaughtered and the muscle samples were collected. Glu supplementation increased the protein/DNA ratio in gastrocnemius muscle, and the protein content in longissimus dorsi (LD) muscle after LPS challenge (P<0.05). In addition, Glu supplementation decreased TLR4, IL-1 receptor-associated kinase (IRAK) 1, receptor-interacting serine/threonine-protein kinase (RIPK) 2, and nuclear factor-κB (NF-κB) mRNA expression in gastrocnemius muscle (P<0.05), MyD88 mRNA expression in LD muscle, and FOXO1 mRNA expression in LD muscle (P<0.05). Moreover, Glu supplementation increased p-Akt/t-Akt ratio (P<0.05) in gastrocnemius muscle, and p-4EBP1/t-4EBP1 ratio in both gastrocnemius and LD muscles (P<0.05). Glu supplementation in the piglets' diets might be an effective strategy to alleviate LPS-induced muscle protein loss, which might be due to suppressing the mRNA expression of TLR4 and NODs signaling-related genes, and modulating Akt/FOXO and mTOR signaling pathways.
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29
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Mitochondrial Function, Obesity, and Personalized Lifestyle Medicine. Integr Med (Encinitas) 2017; 16:14-18. [PMID: 30881251 PMCID: PMC6415631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The future for designing specific interventions targeting improvement in mitochondrial function employing personalized lifestyle intervention is bright given the significant progress that has been made in the field since early investigations in the mid-1980s. This progress is exemplified by the 2017 publication of a controlled exercise and diet intervention trial in obese adults that demonstrated significant improvement in energy, strength, peak oxygen consumption, quality of life, and bone mineral density after the tailored aerobic and resistance exercise program and calorie controlled diet. Being a part of this evolving field of mitochondrial function has been a wonderful experience-one that I have come to more fully appreciate as I look back with a historical perspective on my 30 years of involvement in personalized lifestyle medicine.
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30
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Pillon NJ, Krook A. Innate immune receptors in skeletal muscle metabolism. Exp Cell Res 2017; 360:47-54. [PMID: 28232117 DOI: 10.1016/j.yexcr.2017.02.035] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 02/20/2017] [Indexed: 12/14/2022]
Abstract
Recent decades have seen increasing evidence for a role for both innate and adaptive immunity in response to changes in and in the modulation of metabolic status. This new field of immunometabolism builds on evidence for activation of immune-derived signals in metabolically relevant tissues such as adipose tissue, liver, hypothalamus and skeletal muscle. Skeletal muscle is the primary site of dietary glucose disposal and therefore a key player in the development of diabetes, but studies on the role of inflammation in modulating skeletal muscle metabolism and its possible impact on whole body insulin sensitivity are scarce. This review describes the baseline mRNA expression of innate immune receptors (Toll- and NOD-like receptors) in human skeletal muscle and summarizes studies on putative role of these receptors in skeletal muscle in the context of diabetes, obesity and whole body metabolism.
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Affiliation(s)
- Nicolas J Pillon
- Department of Physiology and Pharmacology, Integrative Physiology, Karolinska Institutet, Stockholm, Sweden.
| | - Anna Krook
- Department of Physiology and Pharmacology, Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
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31
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Meira WV, Heinrich TA, Cadena SMSC, Martinez GR. Melanogenesis inhibits respiration in B16-F10 melanoma cells whereas enhances mitochondrial cell content. Exp Cell Res 2016; 350:62-72. [PMID: 27864061 DOI: 10.1016/j.yexcr.2016.11.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 10/24/2016] [Accepted: 11/02/2016] [Indexed: 11/29/2022]
Abstract
Melanoma is a rare and aggressive skin tumor; the survival of patients diagnosed late is fairly low. This high mortality rate is due to the characteristics of the cells that allow them to be resistant to radiotherapy and conventional chemotherapy, besides of being able to evade the immune system. Melanin, the pigment responsible for skin, hair and eye color, seems to be involved in this resistance. The main function of melanin is to protect the cells against ultraviolet (UV) light by absorbing this radiation and reactive oxygen species (ROS) scavenging. But this pigment may have also a role as photosensitizer, because when it is irradiated with UVA light (320-400 nm), the generation of ROS was detected. Besides, the melanogenesis stimulation on B16-F10 cells resulted in cell cycle arrest, induction of a quiescent state, change in the expression of several proteins and alterations on ADP/ATP ratio. The present study aimed to investigate the influence of melanogenesis stimulation in mitochondrial function of B16-F10 melanoma cells. Therefore, we analyzed cells respiration, mitochondrial membrane potential (Δψm) and mitochondria mass in B16-F10 melanoma cells stimulated with 0.4mML-tyrosine and 10mM NH4Cl. Our results showed that the induction of melanin synthesis was able to reduce significantly the oxygen consumption after 48h of stimulation, without changes of mitochondrial membrane potential when compared to non-stimulated cells. Despite of respiration inhibition, the mitochondria mass was higher in cells with melanogenesis stimulation. We suggest that the stimulation in the melanin synthesis might be promoting the inhibition of electrons transport chain by some intermediate compound from the synthesis of the pigment and this effect could contribute to explain the entry in the quiescent state.
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Affiliation(s)
- Willian Vanderlei Meira
- Department of Biochemistry and Molecular Biology, Federal University of Paraná, Curitiba, PR, Brazil
| | - Tassiele Andréa Heinrich
- Department of Biochemistry and Molecular Biology, Federal University of Paraná, Curitiba, PR, Brazil
| | | | - Glaucia Regina Martinez
- Department of Biochemistry and Molecular Biology, Federal University of Paraná, Curitiba, PR, Brazil.
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Riley CL, Dao C, Kenaston MA, Muto L, Kohno S, Nowinski SM, Solmonson AD, Pfeiffer M, Sack MN, Lu Z, Fiermonte G, Sprague JE, Mills EM. The complementary and divergent roles of uncoupling proteins 1 and 3 in thermoregulation. J Physiol 2016; 594:7455-7464. [PMID: 27647490 DOI: 10.1113/jp272971] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 09/15/2016] [Indexed: 01/23/2023] Open
Abstract
KEY POINTS Both uncoupling protein 1 (UCP1) and UCP3 are important for mammalian thermoregulation. UCP1 and UCP3 in brown adipose tissue mediate early and late phases of sympathomimetic thermogenesis, respectively. Lipopolysaccharide thermogenesis requires skeletal muscle UCP3 but not UCP1. Acute noradrenaline-induced hyperthermia requires UCP1 but not UCP3. Loss of both UCP1 and UCP3 accelerate the loss of body temperature compared to UCP1KO alone during acute cold exposure. ABSTRACT Uncoupling protein 1 (UCP1) is the established mediator of brown adipose tissue-dependent thermogenesis. In contrast, the role of UCP3, expressed in both skeletal muscle and brown adipose tissue, in thermoregulatory physiology is less well understood. Here, we show that mice lacking UCP3 (UCP3KO) have impaired sympathomimetic (methamphetamine) and completely abrogated lipopolysaccharide (LPS) thermogenesis, but a normal response to noradrenaline. By comparison, UCP1 knockout (UCP1KO) mice exhibit blunted methamphetamine and fully inhibited noradrenaline thermogenesis, but an increased febrile response to LPS. We further establish that mice lacking both UCP1 and 3 (UCPDK) fail to show methamphetamine-induced hyperthermia, and have a markedly accelerated loss of body temperature and survival after cold exposure compared to UCP1KO mice. Finally, we show that skeletal muscle-specific human UCP3 expression is able to significantly rescue LPS, but not sympathomimetic thermogenesis blunted in UCP3KO mice. These studies identify UCP3 as an important mediator of physiological thermogenesis and support a renewed focus on targeting UCP3 in metabolic physiology.
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Affiliation(s)
- Christopher L Riley
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Christine Dao
- Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, 78712, USA
| | - M Alexander Kenaston
- Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Luigina Muto
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Cosenza, Italy
| | - Shohei Kohno
- Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Sara M Nowinski
- Department of Biochemistry, The University of Utah, Salt Lake City, UT, 84112, USA
| | - Ashley D Solmonson
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, TX, 78712, USA.,Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Matthew Pfeiffer
- Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Michael N Sack
- National Heart, Lung, and Blood Institute, Laboratory of Mitochondrial Biology and Metabolism, NIH, Bethesda, MD, 20892, USA
| | - Zhongping Lu
- Cardiovascular and Pulmonary Branch and the Department of Biochemistry and Molecular Medicine, George Washington University, and the Veterans Affairs Medical Center, Washington, DC, 20422, 20052, USA
| | - Giuseppe Fiermonte
- Department of Biosciences, Biotechnologies, and Biopharmaceutics and Center of Excellence in Comparative Genomics, University of Bari, 70125, Bari, Italy
| | - Jon E Sprague
- The Ohio Attorney General's Center for the Future of Forensic Science, Bowling Green State University, Bowling Green, OH, 43403, USA
| | - Edward M Mills
- Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, 78712, USA
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High-molecular-weight cocoa procyanidins possess enhanced insulin-enhancing and insulin mimetic activities in human primary skeletal muscle cells compared to smaller procyanidins. J Nutr Biochem 2016; 39:48-58. [PMID: 27816760 DOI: 10.1016/j.jnutbio.2016.10.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 10/01/2016] [Accepted: 10/03/2016] [Indexed: 11/23/2022]
Abstract
Dysregulation of glucose metabolism is a primary hallmark of metabolic disease (i.e., diabetes, obesity, etc.). Complementary nonpharmaceutical strategies are needed to prevent and/or ameliorate dysregulation of glucose metabolism and prevent progression from normoglycemia to prediabetes and type 2 diabetes across the lifespan. Cocoa compounds, particularly the procyanidins, have shown promise for improving insulin sensitivity and blood glucose homeostasis. However, the molecular mechanisms by which cocoa procyanidins exert these functions remain poorly understood. Furthermore, cocoa procyanidins exhibit size diversity, and evidence suggests that procyanidin bioactivity and size may be related. Here, we show that a procyanidin-rich cocoa extract elicits an antidiabetic effect by stimulating glycogen synthesis and glucose uptake, independent of insulin. Cocoa procyanidins did not appear to act via stimulation of AMPK or CaMKII activities. Additionally, in the presence of insulin, glycogen synthesis and AKT phosphorylation were affected. These mechanisms of action are most pronounced in response to oligomeric and polymeric procyanidins. These results demonstrate (1) specific mechanisms by which cocoa procyanidins improve glucose utilization in skeletal muscle and (2) that larger procyanidins appear to possess enhanced activities. These mechanistic insights suggest specific strategies and biological contexts that may be exploited to maximize the antidiabetic benefits of cocoa procyanidins.
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Martin L, Peters C, Heinbockel L, Moellmann J, Martincuks A, Brandenburg K, Lehrke M, Müller-Newen G, Marx G, Schuerholz T. The synthetic antimicrobial peptide 19-2.5 attenuates mitochondrial dysfunction in cardiomyocytes stimulated with human sepsis serum. Innate Immun 2016; 22:612-619. [DOI: 10.1177/1753425916667474] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Septic cardiomyopathy affects up to 70% of patients with septic shock and the derangement of cardiac mitochondrial function contributes to the likelihood of death. However, at present, there is no specific therapeutic drug available. The peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1α (PGC-1α) and coactivator-1β (PGC-1β) modulate members of the PPARs, which regulate mitochondrial energy metabolism and the production of mitochondrial reactive oxygen species in the heart. This study investigated the potential of the newly developed synthetic antimicrobial peptide 19-2.5 (Pep2.5) to attenuate mitochondrial dysfunction in murine cardiomyocytes stimulated with serum from septic shock patients. Pep2.5 treatment attenuated the suppression of PPAR-α, PPAR-γ ( P = 0.0004 and P = 0.0001, respectively) and PGC-1α/β ( P = 0.0008 and P = 0.0147, respectively) in cardiomyocytes stimulated with serum from septic shock patients compared with untreated cells. Pep2.5 treatment enhanced the mitochondrial maximum respiration ( P < 0.0001), increased cellular ATP levels ( P < 0.0001) and reduced the production of mitochondrial reactive oxygen species. Thus, the administration of Pep2.5 may have the potential as a promising therapeutic approach in septic cardiomyopathy by attenuating mitochondrial dysfunction in the septic heart.
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Affiliation(s)
- Lukas Martin
- Department of Intensive Care and Intermediate Care, University Hospital Aachen, Aachen, Germany
| | - Carsten Peters
- Department of Intensive Care and Intermediate Care, University Hospital Aachen, Aachen, Germany
| | - Lena Heinbockel
- Clinical and Experimental Pathology, Forschungszentrum Borstel, Borstel, Germany
| | - Julia Moellmann
- Department of Cardiology, Pneumology, Angiology and Intensive Care, University Hospital Aachen, Aachen, Germany
| | - Antons Martincuks
- Institute of Biochemistry and Molecular Biology, RWTH Aachen University, Aachen, Germany
| | | | - Michael Lehrke
- Institute of Biochemistry and Molecular Biology, RWTH Aachen University, Aachen, Germany
| | - Gerhard Müller-Newen
- Institute of Biochemistry and Molecular Biology, RWTH Aachen University, Aachen, Germany
| | - Gernot Marx
- Department of Intensive Care and Intermediate Care, University Hospital Aachen, Aachen, Germany
| | - Tobias Schuerholz
- Department of Intensive Care and Intermediate Care, University Hospital Aachen, Aachen, Germany
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Kwon OS, Nelson DS, Barrows KM, O'Connell RM, Drummond MJ. Intramyocellular ceramides and skeletal muscle mitochondrial respiration are partially regulated by Toll-like receptor 4 during hindlimb unloading. Am J Physiol Regul Integr Comp Physiol 2016; 311:R879-R887. [PMID: 27581814 DOI: 10.1152/ajpregu.00253.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 08/22/2016] [Indexed: 12/22/2022]
Abstract
Physical inactivity and disuse result in skeletal muscle metabolic disruption, including insulin resistance and mitochondrial dysfunction. The role of the Toll-like receptor 4 (TLR4) signaling pathway in contributing to metabolic decline with muscle disuse is unknown. Therefore, our goal was to determine whether TLR4 is an underlying mechanism of insulin resistance, mitochondrial dysfunction, and skeletal muscle ceramide accumulation following muscle disuse in mice. To address this hypothesis, we subjected (n = 6-8/group) male WT and TLR4-/- mice to 2 wk of hindlimb unloading (HU), while a second group of mice served as ambulatory wild-type controls (WT CON, TLR4-/- CON). Mice were assessed for insulin resistance [homeostatic model assessment-insulin resistance (HOMA-IR), glucose tolerance], and hindlimb muscles (soleus and gastrocnemius) were used to assess muscle sphingolipid abundance, mitochondrial respiration [respiratory control ratio (RCR)], and NF-κB signaling. The primary finding was that HU resulted in insulin resistance, increased total ceramides, specifically Cer18:0 and Cer20:0, and decreased skeletal muscle mitochondrial respiration. Importantly, TLR4-/- HU mice were protected from insulin resistance and altered NF-κB signaling and were partly resistant to muscle atrophy, ceramide accumulation, and decreased RCR. Skeletal muscle ceramides and RCR were correlated with insulin resistance. We conclude that TLR4 is an upstream regulator of insulin sensitivity, while partly upregulating muscle ceramides and worsening mitochondrial respiration during 2 wk of HU.
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Affiliation(s)
- Oh Sung Kwon
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Daniel S Nelson
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | | | - Ryan M O'Connell
- Department of Pathology, University of Utah, Salt Lake City, Utah; and
| | - Micah J Drummond
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah; .,Department of Physical Therapy, University of Utah, Salt Lake City, Utah.,Department of Pathology, University of Utah, Salt Lake City, Utah; and.,Division of Diabetes, Metabolism and Endocrinology, University of Utah, Salt Lake City, Utah
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36
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Boutagy NE, McMillan RP, Frisard MI, Hulver MW. Metabolic endotoxemia with obesity: Is it real and is it relevant? Biochimie 2016; 124:11-20. [PMID: 26133659 PMCID: PMC4695328 DOI: 10.1016/j.biochi.2015.06.020] [Citation(s) in RCA: 251] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 06/23/2015] [Indexed: 02/06/2023]
Abstract
Obesity is associated with metabolic derangements in multiple tissues, which contribute to the progression of insulin resistance and the metabolic syndrome. The underlying stimulus for these metabolic derangements in obesity are not fully elucidated, however recent evidence in rodents and humans suggests that systemic, low level elevations of gut derived endotoxin (lipopolysaccharide, LPS) may play an important role in obesity related, whole-body and tissue specific metabolic perturbations. LPS initiates a well-characterized signaling cascade that elicits many pro- and anti-inflammatory pathways when bound to its receptor, Toll-Like Receptor 4 (TLR4). Low-grade elevation in plasma LPS has been termed "metabolic endotoxemia" and this state is associated with a heightened pro-inflammatory and oxidant environment often observed in obesity. Given the role of inflammatory and oxidative stress in the etiology of obesity related cardio-metabolic disease risk, it has been suggested that metabolic endotoxemia may serve a key mediator of metabolic derangements observed in obesity. This review provides supporting evidence of mechanistic associations with cell and animal models, and provides complimentary evidence of the clinical relevance of metabolic endotoxemia in obesity as it relates to inflammation and metabolic derangements in humans. Discrepancies with endotoxin detection are considered, and an alternate method of reporting metabolic endotoxemia is recommended until a standardized measurement protocol is set forth.
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Affiliation(s)
- Nabil E Boutagy
- The Department of Human Nutrition, Foods, and Exercise, 295 West Campus Drive, Virginia Tech, Blacksburg, VA 24061, USA; The Fralin Translational Obesity Research Center, 1981 Kraft Drive, Virginia Tech, Blacksburg, VA 24061, USA; The Metabolic Phenotyping Core, 1981 Kraft Drive, Virginia Tech, Blacksburg, VA 24061, USA.
| | - Ryan P McMillan
- The Department of Human Nutrition, Foods, and Exercise, 295 West Campus Drive, Virginia Tech, Blacksburg, VA 24061, USA; The Fralin Translational Obesity Research Center, 1981 Kraft Drive, Virginia Tech, Blacksburg, VA 24061, USA; The Metabolic Phenotyping Core, 1981 Kraft Drive, Virginia Tech, Blacksburg, VA 24061, USA.
| | - Madlyn I Frisard
- The Department of Human Nutrition, Foods, and Exercise, 295 West Campus Drive, Virginia Tech, Blacksburg, VA 24061, USA; The Fralin Translational Obesity Research Center, 1981 Kraft Drive, Virginia Tech, Blacksburg, VA 24061, USA; The Metabolic Phenotyping Core, 1981 Kraft Drive, Virginia Tech, Blacksburg, VA 24061, USA.
| | - Matthew W Hulver
- The Department of Human Nutrition, Foods, and Exercise, 295 West Campus Drive, Virginia Tech, Blacksburg, VA 24061, USA; The Fralin Translational Obesity Research Center, 1981 Kraft Drive, Virginia Tech, Blacksburg, VA 24061, USA; The Metabolic Phenotyping Core, 1981 Kraft Drive, Virginia Tech, Blacksburg, VA 24061, USA.
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37
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Li DJ, Fu H, Zhao T, Ni M, Shen FM. Exercise-stimulated FGF23 promotes exercise performance via controlling the excess reactive oxygen species production and enhancing mitochondrial function in skeletal muscle. Metabolism 2016; 65:747-756. [PMID: 27085781 DOI: 10.1016/j.metabol.2016.02.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Revised: 02/02/2016] [Accepted: 02/16/2016] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Physical exercise induces many adaptive changes in skeletal muscle and the whole body and improves metabolic characteristics. Fibroblast growth-factor 23 (FGF23) is a unique member of the FGF family that acts as a hormone regulating phosphate metabolism, calcitriol concentration, and kidney functions. The role of FGF23 in exercise and skeletal muscle is largely unknown yet. MATERIALS AND METHODS C57BL/6J mice were exercised on a motor treadmill. Mice serum FGF23 levels; FGF23 mRNA expression in various organs including the liver, heart, skeletal muscle tissue, and thyroid; and FGF23 receptor Klotho mRNA expression were examined using enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and immunoblotting, respectively, after a single bout of acute exercise (60min), exhaustive exercise, and chronic prolonged exercise (60min every day for one week). C57BL/6J mice were injected with recombinant FGF23 (100mg/kg, twice per day, i.p.) or vehicle control (saline) for 3days, and then the exercise performance, reactive oxygen species (ROS), H2O2 production, and mitochondrial functional biomarkers in muscle (gene expression of sirtuin 1, PPAR-δ, PGC-1α and mitochondrial transcription factor A [TFAM], and citrate synthase activity) were assayed. RESULTS Three forms of exercise, acute exercise, exhaustive exercise, and chronic exercise, increased serum FGF23 levels. However, only chronic exercise upregulated FGF23 mRNA and protein expression in skeletal muscle. FGF23 mRNA expression in the heart, liver, and thyroid was not affected. FGF23 protein was mainly located in the cytoplasm in skeletal muscle tissue and the localization of FGF23 was not altered by exercise. Exogenous FGF23 treatment significantly extended the time to exhaustion and reduced the exercise-induced ROS and H2O2 production. FGF23 treatment increased the mRNA level of PPAR-δ and citrate synthase activity, but did not influence the mRNA expression of sirtuin 1, PGC-1α, and TFAM in skeletal muscle. CONCLUSION These results demonstrate that exercise-stimulated FGF23 promotes exercise performance via controlling the excess ROS production and enhancing mitochondrial function in skeletal muscle, which reveals an entirely novel role of FGF23 in skeletal muscle.
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Affiliation(s)
- Dong-Jie Li
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University, Shanghai, 200072, China
| | - Hui Fu
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University, Shanghai, 200072, China
| | - Ting Zhao
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University, Shanghai, 200072, China
| | - Min Ni
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University, Shanghai, 200072, China
| | - Fu-Ming Shen
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University, Shanghai, 200072, China.
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38
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Bloise FF, van der Spek AH, Surovtseva OV, Ortiga-Carvalho TM, Fliers E, Boelen A. Differential Effects of Sepsis and Chronic Inflammation on Diaphragm Muscle Fiber Type, Thyroid Hormone Metabolism, and Mitochondrial Function. Thyroid 2016; 26:600-9. [PMID: 26892873 DOI: 10.1089/thy.2015.0536] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND The diaphragm is the main respiratory muscle, and its function is compromised during severe illness. Altered local thyroid hormone (TH) metabolism may be a determinant of impaired muscle function during illness. METHODS This study investigates the effects of bacterial sepsis and chronic inflammation on muscle fiber type, local TH metabolism, and mitochondrial function in the diaphragm. Two mouse models were used: sepsis induced by S. pneumoniae infection or chronic inflammation induced by subcutaneous turpentine injection. In vitro, the effect of bacterial endotoxin (LPS) on mitochondrial function in C2C12 myotubes was studied. RESULTS Sepsis induced a transient increase in the fiber type I profile and increased Dio3 expression while decreasing Dio2, Thra1, and Slc16a2 expression. Triiodothyronine positively regulated genes Tnni2 and Myog were decreased, indicating reduced TH signaling in the diaphragm. In contrast, chronic inflammation increased the fiber type II profile in the diaphragm as well as Thra1, Thrb1, and Myog expression while decreasing Dio3 expression, suggesting increased TH responsiveness during chronic inflammation. LPS-stimulated C2C12 myotubes showed decreased Dio2 expression and reduced basal oxygen consumption as well as non-mitochondrial respiration. The same respiratory profile was induced by Dio2 knockdown in myotubes. CONCLUSIONS The in vivo results show differential effects of sepsis and chronic inflammation on diaphragm muscle fiber type, TH metabolism, and mitochondrial function, while the in vitro results point to a causal role for altered TH metabolism in functional muscle impairment. These findings may be relevant for the pathogenesis of impaired respiratory function in critical illness.
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Affiliation(s)
- Flavia F Bloise
- 1 Department of Endocrinology and Metabolism, Academic Medical Centre, University of Amsterdam , Amsterdam, The Netherlands
- 2 Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro , Rio de Janeiro, Brazil
| | - Anne H van der Spek
- 1 Department of Endocrinology and Metabolism, Academic Medical Centre, University of Amsterdam , Amsterdam, The Netherlands
| | - Olga V Surovtseva
- 1 Department of Endocrinology and Metabolism, Academic Medical Centre, University of Amsterdam , Amsterdam, The Netherlands
| | - Tania Maria Ortiga-Carvalho
- 2 Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro , Rio de Janeiro, Brazil
| | - Eric Fliers
- 1 Department of Endocrinology and Metabolism, Academic Medical Centre, University of Amsterdam , Amsterdam, The Netherlands
| | - Anita Boelen
- 1 Department of Endocrinology and Metabolism, Academic Medical Centre, University of Amsterdam , Amsterdam, The Netherlands
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Mechanisms by which cocoa flavanols improve metabolic syndrome and related disorders. J Nutr Biochem 2016; 35:1-21. [PMID: 27560446 DOI: 10.1016/j.jnutbio.2015.12.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 12/17/2015] [Accepted: 12/18/2015] [Indexed: 12/24/2022]
Abstract
Dietary administration of cocoa flavanols may be an effective complementary strategy for alleviation or prevention of metabolic syndrome, particularly glucose intolerance. The complex flavanol composition of cocoa provides the ability to interact with a variety of molecules, thus allowing numerous opportunities to ameliorate metabolic diseases. These interactions likely occur primarily in the gastrointestinal tract, where native cocoa flavanol concentration is high. Flavanols may antagonize digestive enzymes and glucose transporters, causing a reduction in glucose excursion, which helps patients with metabolic disorders maintain glucose homeostasis. Unabsorbed flavanols, and ones that undergo enterohepatic recycling, will proceed to the colon where they can exert prebiotic effects on the gut microbiota. Interactions with the gut microbiota may improve gut barrier function, resulting in attenuated endotoxin absorption. Cocoa may also positively influence insulin signaling, possibly by relieving insulin-signaling pathways from oxidative stress and inflammation and/or via a heightened incretin response. The purpose of this review is to explore the mechanisms that underlie these outcomes, critically review the current body of literature related to those mechanisms, explore the implications of these mechanisms for therapeutic utility, and identify emerging or needed areas of research that could advance our understanding of the mechanisms of action and therapeutic potential of cocoa flavanols.
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40
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Boutagy NE, Rogers GW, Pyne ES, Ali MM, Hulver MW, Frisard MI. Using Isolated Mitochondria from Minimal Quantities of Mouse Skeletal Muscle for High throughput Microplate Respiratory Measurements. J Vis Exp 2015:e53216. [PMID: 26555567 PMCID: PMC4692683 DOI: 10.3791/53216] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Skeletal muscle mitochondria play a specific role in many disease pathologies. As such, the measurement of oxygen consumption as an indicator of mitochondrial function in this tissue has become more prevalent. Although many technologies and assays exist that measure mitochondrial respiratory pathways in a variety of cells, tissue and species, there is currently a void in the literature in regards to the compilation of these assays using isolated mitochondria from mouse skeletal muscle for use in microplate based technologies. Importantly, the use of microplate based respirometric assays is growing among mitochondrial biologists as it allows for high throughput measurements using minimal quantities of isolated mitochondria. Therefore, a collection of microplate based respirometric assays were developed that are able to assess mechanistic changes/adaptations in oxygen consumption in a commonly used animal model. The methods presented herein provide step-by-step instructions to perform these assays with an optimal amount of mitochondrial protein and reagents, and high precision as evidenced by the minimal variance across the dynamic range of each assay.
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Affiliation(s)
- Nabil E Boutagy
- The Department of Human Nutrition, Foods, and Exercise, Virginia Tech; The Metabolic Phenotyping Core, Virginia Tech;
| | | | - Emily S Pyne
- The Department of Human Nutrition, Foods, and Exercise, Virginia Tech
| | - Mostafa M Ali
- The Department of Human Nutrition, Foods, and Exercise, Virginia Tech
| | - Matthew W Hulver
- The Department of Human Nutrition, Foods, and Exercise, Virginia Tech; The Metabolic Phenotyping Core, Virginia Tech
| | - Madlyn I Frisard
- The Department of Human Nutrition, Foods, and Exercise, Virginia Tech; The Metabolic Phenotyping Core, Virginia Tech
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McMillan RP, Wu Y, Voelker K, Fundaro G, Kavanaugh J, Stevens JR, Shabrokh E, Ali M, Harvey M, Anderson AS, Boutagy NE, Mynatt RL, Frisard MI, Hulver MW. Selective overexpression of Toll-like receptor-4 in skeletal muscle impairs metabolic adaptation to high-fat feeding. Am J Physiol Regul Integr Comp Physiol 2015; 309:R304-13. [PMID: 26084695 DOI: 10.1152/ajpregu.00139.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 06/11/2015] [Indexed: 12/22/2022]
Abstract
Toll-like receptor-4 (TLR-4) is elevated in skeletal muscle of obese humans, and data from our laboratory have shown that activation of TLR-4 in skeletal muscle via LPS results in decreased fatty acid oxidation (FAO). The purpose of this study was to determine whether overexpression of TLR-4 in skeletal muscle alters mitochondrial function and whole body metabolism in the context of a chow and high-fat diet. C57BL/6J mice (males, 6-8 mo of age) with skeletal muscle-specific overexpression of the TLR-4 (mTLR-4) gene were created and used for this study. Isolated mitochondria and whole muscle homogenates from rodent skeletal muscle (gastrocnemius and quadriceps) were investigated. TLR-4 overexpression resulted in a significant reduction in FAO in muscle homogenates; however, mitochondrial respiration and reactive oxygen species (ROS) production did not appear to be affected on a standard chow diet. To determine the role of TLR-4 overexpression in skeletal muscle in response to high-fat feeding, mTLR-4 mice and WT control mice were fed low- and high-fat diets for 16 wk. The high-fat diet significantly decreased FAO in mTLR-4 mice, which was observed in concert with elevated body weight and fat, greater glucose intolerance, and increase in production of ROS and cellular oxidative damage compared with WT littermates. These findings suggest that TLR-4 plays an important role in the metabolic response in skeletal muscle to high-fat feeding.
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Affiliation(s)
- Ryan P McMillan
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia; Metabolic Phenotyping Core, Virginia Tech, Blacksburg, Virginia; Fralin Translational Obesity Research Center, Virginia Tech, Blacksburg, Virginia
| | - Yaru Wu
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia
| | - Kevin Voelker
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia
| | - Gabrielle Fundaro
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia
| | - John Kavanaugh
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia
| | - Joseph R Stevens
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia; Fralin Translational Obesity Research Center, Virginia Tech, Blacksburg, Virginia
| | - Elika Shabrokh
- Department of Surgery, University of Michigan Medical School, Ann Arbor, Michigan; and
| | - Mostafa Ali
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia
| | - Mordecai Harvey
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia
| | - Angela S Anderson
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia
| | - Nabil E Boutagy
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia; Fralin Translational Obesity Research Center, Virginia Tech, Blacksburg, Virginia
| | - Randall L Mynatt
- Gene Nutrient Interactions, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Madlyn I Frisard
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia; Metabolic Phenotyping Core, Virginia Tech, Blacksburg, Virginia; Fralin Translational Obesity Research Center, Virginia Tech, Blacksburg, Virginia
| | - Matthew W Hulver
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia; Metabolic Phenotyping Core, Virginia Tech, Blacksburg, Virginia; Fralin Translational Obesity Research Center, Virginia Tech, Blacksburg, Virginia;
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