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Martin R, Nora M, Anna L, Olivia P, Leif B, Gunilla WT, Ellen T, Anna-Karin LC. Altered hypoxia-induced cellular responses and inflammatory profile in lung fibroblasts from COPD patients compared to control subjects. Respir Res 2024; 25:282. [PMID: 39014439 PMCID: PMC11253402 DOI: 10.1186/s12931-024-02907-x] [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: 03/28/2024] [Accepted: 07/04/2024] [Indexed: 07/18/2024] Open
Abstract
BACKGROUND Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterized by chronic bronchitis, emphysema and vascular remodelling. The disease is associated with hypoxia, inflammation and oxidative stress. Lung fibroblasts are important cells in remodelling processes in COPD, as main producers of extracellular matrix proteins but also in synthesis of growth factors and inflammatory mediators. METHODS In this study we aimed to investigate if there are differences in how primary distal lung fibroblasts obtained from COPD patients and healthy subjects respond to hypoxia (1% O2) and pro-fibrotic stimuli with TGF-β1 (10 ng/mL). Genes and proteins associated with oxidative stress, endoplasmic reticulum stress, remodelling and inflammation were analysed with RT-qPCR and ELISA. RESULTS Hypoxia induced differences in expression of genes involved in oxidative stress (SOD3 and HIF-1α), ER stress (IRE1, PARK and ATF6), apoptosis (c-Jun and Bcl2) and remodelling (5HTR2B, Collagen7 and VEGFR2) in lung fibroblasts from COPD subjects compared to control subjects, where COPD fibroblasts were in general less responsive. The release of VEGF-C was increased after hypoxia, whereas TGF-β significantly reduced the VEGF response to hypoxia and the release of HGF. COPD fibroblasts had a higher release of IL-6, IL-8, MCP-1 and PGE2 compared to lung fibroblasts from control subjects. The release of inflammatory mediators was less affected by hypoxia, whereas TGFβ1 induced differences in inflammatory profile between fibroblasts from COPD and control subjects. CONCLUSION These results suggest that there is an alteration of gene regulation of various stress responses and remodelling associated mediator release that is related to COPD and hypoxia, where fibroblasts from COPD patients have a deficient response.
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Affiliation(s)
- Ryde Martin
- Lung Biology, Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden.
- Respiratory Medicine, Allergology and Palliative Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden.
| | - Marek Nora
- Lung Biology, Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden
| | - Löfdahl Anna
- Lung Biology, Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden
| | - Pekny Olivia
- Lung Biology, Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden
| | - Bjermer Leif
- Respiratory Medicine, Allergology and Palliative Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
| | - Westergren-Thorsson Gunilla
- Lung Biology, Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden
| | - Tufvesson Ellen
- Respiratory Medicine, Allergology and Palliative Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
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Ó Murchú SC, O'Halloran KD. BREATHE DMD: boosting respiratory efficacy after therapeutic hypoxic episodes in Duchenne muscular dystrophy. J Physiol 2024; 602:3255-3272. [PMID: 38837229 DOI: 10.1113/jp280280] [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: 03/08/2024] [Accepted: 05/12/2024] [Indexed: 06/07/2024] Open
Abstract
Duchenne muscular dystrophy (DMD) is a fatal genetic neuromuscular disorder, characterised by progressive decline in skeletal muscle function due to the secondary consequences of dystrophin deficiency. Weakness extends to the respiratory musculature, and cardiorespiratory failure is the leading cause of death in men with DMD. Intermittent hypoxia has emerged as a potential therapy to counteract ventilatory insufficiency by eliciting long-term facilitation of breathing. Mechanisms of sensory and motor facilitation of breathing have been well delineated in animal models. Various paradigms of intermittent hypoxia have been designed and implemented in human trials culminating in clinical trials in people with spinal cord injury and amyotrophic lateral sclerosis. Application of therapeutic intermittent hypoxia to DMD is considered together with discussion of the potential barriers to progression owing to the complexity of this devastating disease. Notwithstanding the considerable challenges and potential pitfalls of intermittent hypoxia-based therapies for DMD, we suggest it is incumbent on the research community to explore the potential benefits in pre-clinical models. Intermittent hypoxia paradigms should be implemented to explore the proclivity to express respiratory plasticity with the longer-term aim of preserving and potentiating ventilation in pre-clinical models and people with DMD.
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Affiliation(s)
- Seán C Ó Murchú
- Department of Physiology, University College Cork, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, University College Cork, Cork, Ireland
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3
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Welch N, Mishra S, Bellar A, Kannan P, Gopan A, Goudarzi M, King J, Luknis M, Musich R, Agrawal V, Bena J, Koch CJ, Li L, Willard B, Shah YM, Dasarathy S. Differential impact of sex on regulation of skeletal muscle mitochondrial function and protein homeostasis by hypoxia-inducible factor-1α in normoxia. J Physiol 2024; 602:2763-2806. [PMID: 38761133 PMCID: PMC11178475 DOI: 10.1113/jp285339] [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: 07/29/2023] [Accepted: 04/19/2024] [Indexed: 05/20/2024] Open
Abstract
Hypoxia-inducible factor (HIF)-1α is continuously synthesized and degraded in normoxia. During hypoxia, HIF1α stabilization restricts cellular/mitochondrial oxygen utilization. Cellular stressors can stabilize HIF1α even during normoxia. However, less is known about HIF1α function(s) and sex-specific effects during normoxia in the basal state. Since skeletal muscle is the largest protein store in mammals and protein homeostasis has high energy demands, we determined HIF1α function at baseline during normoxia in skeletal muscle. Untargeted multiomics data analyses were followed by experimental validation in differentiated murine myotubes with loss/gain of function and skeletal muscle from mice without/with post-natal muscle-specific Hif1a deletion (Hif1amsd). Mitochondrial oxygen consumption studies using substrate, uncoupler, inhibitor, titration protocols; targeted metabolite quantification by gas chromatography-mass spectrometry; and post-mitotic senescence markers using biochemical assays were performed. Multiomics analyses showed enrichment in mitochondrial and cell cycle regulatory pathways in Hif1a deleted cells/tissue. Experimentally, mitochondrial oxidative functions and ATP content were higher with less mitochondrial free radical generation with Hif1a deletion. Deletion of Hif1a also resulted in higher concentrations of TCA cycle intermediates and HIF2α proteins in myotubes. Overall responses to Hif1amsd were similar in male and female mice, but changes in complex II function, maximum respiration, Sirt3 and HIF1β protein expression and muscle fibre diameter were sex-dependent. Adaptive responses to hypoxia are mediated by stabilization of constantly synthesized HIF1α. Despite rapid degradation, the presence of HIF1α during normoxia contributes to lower mitochondrial oxidative efficiency and greater post-mitotic senescence in skeletal muscle. In vivo responses to HIF1α in skeletal muscle were differentially impacted by sex. KEY POINTS: Hypoxia-inducible factor -1α (HIF1α), a critical transcription factor, undergoes continuous synthesis and proteolysis, enabling rapid adaptive responses to hypoxia by reducing mitochondrial oxygen consumption. In mammals, skeletal muscle is the largest protein store which is determined by a balance between protein synthesis and breakdown and is sensitive to mitochondrial oxidative function. To investigate the functional consequences of transient HIF1α expression during normoxia in the basal state, myotubes and skeletal muscle from male and female mice with HIF1α knockout were studied using complementary multiomics, biochemical and metabolite assays. HIF1α knockout altered the electron transport chain, mitochondrial oxidative function, signalling molecules for protein homeostasis, and post-mitotic senescence markers, some of which were differentially impacted by sex. The cost of rapid adaptive responses mediated by HIF1α is lower mitochondrial oxidative efficiency and post-mitotic senescence during normoxia.
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Affiliation(s)
- Nicole Welch
- Departments of Inflammation and Immunity, Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, OH, USA
| | - Saurabh Mishra
- Departments of Inflammation and Immunity, Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, OH, USA
| | - Annette Bellar
- Departments of Inflammation and Immunity, Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, OH, USA
| | - Pugazhendhi Kannan
- Departments of Inflammation and Immunity, Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, OH, USA
| | - Amrit Gopan
- KEM Hospital, Seth GS Medical College, Mumbai, India
| | - Maryam Goudarzi
- Respiratory Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Jasmine King
- Departments of Inflammation and Immunity, Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, OH, USA
| | - Mathew Luknis
- Departments of Inflammation and Immunity, Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, OH, USA
| | - Ryan Musich
- Departments of Inflammation and Immunity, Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, OH, USA
| | - Vandana Agrawal
- Departments of Inflammation and Immunity, Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, OH, USA
| | - James Bena
- Quantitative Health, Cleveland Clinic, Cleveland, Ohio, USA
| | | | - Ling Li
- Proteomics and Metabolomics Core, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Belinda Willard
- Proteomics and Metabolomics Core, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Yatrik M Shah
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Srinivasan Dasarathy
- Departments of Inflammation and Immunity, Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, OH, USA
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Hu Z, Tang L, Zhan Y. Cognition as mediator of pulmonary function and risk of sarcopenia among older adults. BMC Public Health 2024; 24:1347. [PMID: 38762539 PMCID: PMC11102626 DOI: 10.1186/s12889-024-18848-5] [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: 03/21/2024] [Accepted: 05/14/2024] [Indexed: 05/20/2024] Open
Abstract
BACKGROUND The relationship between lung function and sarcopenia remains ambiguous. The primary aim of this study was to investigate the potential association between lung function and sarcopenia in the older adults, as well as to examine the mediating role of cognitive function in this relationship. METHODS The participants were selected from a nationally representative population-based cohort in China. The peak expiratory flow (PEF) measurement was used to evaluate the lung function in older persons. The sarcopenia was diagnosed using the guidelines of the Asian Working Group for Sarcopenia (AWGS) in 2019. The Cox proportional hazard model was utilized to perform primary analyses of the relationship between PEF and sarcopenia. The mediating effect of cognitive function was evaluated using the counterfactual mediation method. RESULTS This cohort study included 4,011 older adults (average age, 66.6 years; 53.3% males). During a follow-up period of 3.86 years, 349 individuals were diagnosed with sarcopenia. After adjusting for potential confounders, each one-standard-deviation increase in PEF was associated with a 28% reduction in the risk of sarcopenia (hazard ratio [HR]: 0.72; 95% confidence interval [CI]: 0.63, 0.80). There was a significant mediation of cognition for the association between PEF and incident sarcopenia, and the proportion mediated was 12.2% (95% CI: 4.5%, 23.1%). CONCLUSIONS Older adults with impaired lung function are more likely to develop sarcopenia. Nevertheless, cognition can explain only a small portion of this association. Thus, other potential pathways between lung function and sarcopenia must be elucidated.
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Affiliation(s)
- Zhao Hu
- Department of Epidemiology, School of Public Health (Shenzhen), Sun Yat-Sen University, Shenzhen, China.
| | - Lu Tang
- The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China
| | - Yiqiang Zhan
- Department of Epidemiology, School of Public Health (Shenzhen), Sun Yat-Sen University, Shenzhen, China.
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
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Attaway AH, Lopez R, Welch N, Bellar A, Hatipoğlu U, Zein J, Engelen MP, Dasarathy S. Muscle loss phenotype in COPD is associated with adverse outcomes in the UK Biobank. BMC Pulm Med 2024; 24:186. [PMID: 38632546 PMCID: PMC11025247 DOI: 10.1186/s12890-024-02999-7] [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: 12/06/2023] [Accepted: 04/08/2024] [Indexed: 04/19/2024] Open
Abstract
BACKGROUND Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disorder with systemic consequences that can cause a muscle loss phenotype (MLP), which is characterized by the loss of muscle mass, muscle strength, or loss of both muscle and fat mass. There are limited data comparing the individual traits of MLP with clinical outcomes in a large unbiased cohort of COPD patients. Our aim was to determine the proportion of patients who met criteria for MLP in an unbiased sample of COPD patients at the population-level. We also determined if specific MLP features were associated with all-cause and COPD-related mortality. METHODS A retrospective population-based cohort analysis of the UK Biobank was performed. COPD was defined by a FEV1/FVC ratio < 0.7, physician established diagnosis of COPD, or those with a COPD-related hospitalization before baseline assessment. MLP included one or more of the following: 1) Low fat-free mass index (FFMI) on bioelectric impedance analysis (BIA) or 2) Appendicular skeletal muscle index (ASMI) on BIA, 3) Low muscle strength defined by handgrip strength (HGS), or 4) Low muscle and fat mass based on body mass index (BMI). Cox regression was used to determine the association between MLP and all-cause or COPD-related mortality. All models were adjusted for sex, age at assessment, ethnicity, BMI, alcohol use, smoking status, prior cancer diagnosis and FEV1/FVC ratio. RESULTS There were 55,782 subjects (56% male) with COPD followed for a median of 70.1 months with a mean(± SD) age at assessment of 59 ± 7.5 years, and FEV1% of 79.2 ± 18.5. Most subjects had mild (50.4%) or moderate (42.8%) COPD. Many patients had evidence of a MLP, which was present in 53.4% of COPD patients (34% by ASMI, 26% by HGS). Of the 5,608 deaths in patients diagnosed with COPD, 907 were COPD-related. After multivariate adjustment, COPD subjects with MLP had a 30% higher hazard-ratio for all-cause death and 70% higher hazard-ratio for COPD-related death. CONCLUSIONS Evidence of MLP is common in a large population-based cohort of COPD and is associated with higher risk for all-cause and COPD-related mortality.
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Affiliation(s)
- Amy H Attaway
- Departments of Pulmonary Medicine, Cleveland Clinic, Cleveland, OH, USA
| | - Rocio Lopez
- Center for Populations Health Research, Cleveland Clinic, Cleveland, OH, USA
| | - Nicole Welch
- Inflammation and Immunity, Cleveland Clinic, Cleveland, OH, USA
- Gastroenterology and Hepatology, Cleveland Clinic, Cleveland, OH, USA
| | - Annette Bellar
- Inflammation and Immunity, Cleveland Clinic, Cleveland, OH, USA
| | - Umur Hatipoğlu
- Departments of Pulmonary Medicine, Cleveland Clinic, Cleveland, OH, USA
| | - Joe Zein
- Department of Medicine, Mayo Clinic, Scottsdale, AZ, USA
| | | | - Srinivasan Dasarathy
- Inflammation and Immunity, Cleveland Clinic, Cleveland, OH, USA.
- Gastroenterology and Hepatology, Cleveland Clinic, Cleveland, OH, USA.
- Department of Inflammation and Immunity, Lerner Research Institute, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
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Kumar A, Bellar A, Mishra S, Sekar J, Welch N, Dasarathy S. L-Isoleucine reverses hyperammonemia-induced myotube mitochondrial dysfunction and post-mitotic senescence. J Nutr Biochem 2024; 123:109498. [PMID: 37871767 PMCID: PMC10841977 DOI: 10.1016/j.jnutbio.2023.109498] [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: 03/12/2023] [Revised: 10/16/2023] [Accepted: 10/19/2023] [Indexed: 10/25/2023]
Abstract
Perturbations in the metabolism of ammonia, a cytotoxic endogenous metabolite, occur in a number of chronic diseases, with consequent hyperammonemia. Increased skeletal muscle ammonia uptake causes metabolic, molecular, and phenotype alterations including cataplerosis of (loss of tricarboxylic acid cycle (TCA) cycle intermediate) α-ketoglutarate (αKG), mitochondrial oxidative dysfunction, and senescence-associated molecular phenotype (SAMP). L-Isoleucine (Ile) is an essential, branched-chain amino acid (BCAA) that simultaneously provides acetyl-CoA as an oxidative substrate and succinyl-CoA for anaplerosis (providing TCA cycle intermediates). Our multiomics analyses in myotubes and skeletal muscle from hyperammonemic mice and human patients with cirrhosis showed perturbations in BCAA transporters and catabolism. We, therefore, determined if Ile reverses hyperammonemia-induced impaired mitochondrial oxidative function and SAMP. Studies were performed in differentiated murine C2C12 myotubes that were early passage, late passage (senescent), or those depleted of LAT1/SLC7A5 and human induced pluripotent stem cell-derived myotubes (hiPSCM). Ile reverses hyperammonemia-induced reduction in the maximum respiratory capacity, complex I, II, and III functions in early passage murine myotubes and hiPSCM. Consistently, low ATP content and impaired global protein synthesis (high energy requiring cellular process) during hyperammonemia are reversed by Ile in murine myotubes and hiPSCM. Lower abundance of critical regulators of protein synthesis in mTORC1 signaling, and increased phosphorylation of eukaryotic initiation factor 2α are also reversed by Ile. Genetic depletion studies showed that Ile responses are independent of the amino acid transporter LAT1/SLC7A5. Our studies show that Ile reverses the hyperammonemia-induced impaired mitochondrial oxidative function, cataplerosis, and SAMP in a LAT1/SLC7A5 transporter-independent manner.
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Affiliation(s)
- Avinash Kumar
- Department of Gastroenterology, Hepatology and Nutrition, All India Institute of Medical Sciences, New Delhi, India
| | - Annette Bellar
- Department of Inflammation and Immunity, Lerner Research Institute, Gastroenterology and Hepatology, Cleveland Clinic, Cleveland, Ohio, USA
| | - Saurabh Mishra
- Department of Inflammation and Immunity, Lerner Research Institute, Gastroenterology and Hepatology, Cleveland Clinic, Cleveland, Ohio, USA
| | - Jinendiran Sekar
- Department of Inflammation and Immunity, Lerner Research Institute, Gastroenterology and Hepatology, Cleveland Clinic, Cleveland, Ohio, USA
| | - Nicole Welch
- Department of Inflammation and Immunity, Lerner Research Institute, Gastroenterology and Hepatology, Cleveland Clinic, Cleveland, Ohio, USA
| | - Srinivasan Dasarathy
- Department of Inflammation and Immunity, Lerner Research Institute, Gastroenterology and Hepatology, Cleveland Clinic, Cleveland, Ohio, USA.
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Sekar J, Attaway AH. The intersection of HIF-1α, O-GlcNAc, and skeletal muscle loss in chronic obstructive pulmonary disease. Glycobiology 2023; 33:873-878. [PMID: 37812446 PMCID: PMC10859630 DOI: 10.1093/glycob/cwad081] [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: 06/15/2023] [Revised: 09/29/2023] [Accepted: 10/04/2023] [Indexed: 10/10/2023] Open
Abstract
Sarcopenia, defined as the loss of muscle mass and strength, is a major cause of morbidity and mortality in COPD (chronic obstructive pulmonary disease) patients. However, the molecular mechanisms that cause sarcopenia remain to be determined. In this review, we will highlight the unique molecular and metabolic perturbations that occur in the skeletal muscle of COPD patients in response to hypoxia, and emphasize important areas of future research. In particular, the mechanisms related to the glycolytic shift that occurs in skeletal muscle in response to hypoxia may occur via a hypoxia-inducible factor 1-alpha (HIF-1α)-mediated mechanism. Upregulated glycolysis in skeletal muscle promotes a unique post-translational glycosylation of proteins known as O-GlcNAcylation, which further shifts metabolism toward glycolysis. Molecular changes in the skeletal muscle of COPD patients are associated with fiber-type shifting from Type I (oxidative) muscle fibers to Type II (glycolytic) muscle fibers. The metabolic shift toward glycolysis caused by HIF-1α and O-GlcNAc modified proteins suggests a potential cause for sarcopenia in COPD, which is an emerging area of future research.
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Affiliation(s)
- Jinendiran Sekar
- Division of Infectious Diseases, Harbor-UCLA Medical Center, 1000 West Carson Street, MRL Building, Box 466; Torrance, CA 90502, United States
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, 1124 W Carson St, Torrance, CA 90502, United States
| | - Amy H Attaway
- Respiratory Institute, Cleveland Clinic, Cleveland Clinic Main Campus, Mail Code A90, 9500 Euclid Avenue, Cleveland, OH 44195, United States
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Attaway AH, Bellar A, Welch N, Sekar J, Kumar A, Mishra S, Hatipoğlu U, McDonald M, Regan EA, Smith JD, Washko G, Estépar RSJ, Bazeley P, Zein J, Dasarathy S. Gene polymorphisms associated with heterogeneity and senescence characteristics of sarcopenia in chronic obstructive pulmonary disease. J Cachexia Sarcopenia Muscle 2023; 14:1083-1095. [PMID: 36856146 PMCID: PMC10067501 DOI: 10.1002/jcsm.13198] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 01/16/2023] [Accepted: 01/22/2023] [Indexed: 03/02/2023] Open
Abstract
BACKGROUND Sarcopenia, or loss of skeletal muscle mass and decreased contractile strength, contributes to morbidity and mortality in patients with chronic obstructive pulmonary disease (COPD). The severity of sarcopenia in COPD is variable, and there are limited data to explain phenotype heterogeneity. Others have shown that COPD patients with sarcopenia have several hallmarks of cellular senescence, a potential mechanism of primary (age-related) sarcopenia. We tested if genetic contributors explain the variability in sarcopenic phenotype and accelerated senescence in COPD. METHODS To identify gene variants [single nucleotide polymorphisms (SNPs)] associated with sarcopenia in COPD, we performed a genome-wide association study (GWAS) of fat free mass index (FFMI) in 32 426 non-Hispanic White (NHW) UK Biobank participants with COPD. Several SNPs within the fat mass and obesity-associated (FTO) gene were associated with sarcopenia that were validated in an independent COPDGene cohort (n = 3656). Leucocyte telomere length quantified in the UK Biobank cohort was used as a marker of senescence. Experimental validation was done by genetic depletion of FTO in murine skeletal myotubes exposed to prolonged intermittent hypoxia or chronic hypoxia because hypoxia contributes to sarcopenia in COPD. Molecular biomarkers for senescence were also quantified with FTO depletion in murine myotubes. RESULTS Multiple SNPs located in the FTO gene were associated with sarcopenia in addition to novel SNPs both within and in proximity to the gene AC090771.2, which transcribes long non-coding RNA (lncRNA). To replicate our findings, we performed a GWAS of FFMI in NHW subjects from COPDGene. The SNP most significantly associated with FFMI was on chromosome (chr) 16, rs1558902A > T in the FTO gene (β = 0.151, SE = 0.021, P = 1.40 × 10-12 for UK Biobank |β= 0.220, SE = 0.041, P = 9.99 × 10-8 for COPDGene) and chr 18 SNP rs11664369C > T nearest to the AC090771.2 gene (β = 0.129, SE = 0.024, P = 4.64 × 10-8 for UK Biobank |β = 0.203, SE = 0.045, P = 6.38 × 10-6 for COPDGene). Lower handgrip strength, a measure of muscle strength, but not FFMI was associated with reduced telomere length in the UK Biobank. Experimentally, in vitro knockdown of FTO lowered myotube diameter and induced a senescence-associated molecular phenotype, which was worsened by prolonged intermittent hypoxia and chronic hypoxia. CONCLUSIONS Genetic polymorphisms of FTO and AC090771.2 were associated with sarcopenia in COPD in independent cohorts. Knockdown of FTO in murine myotubes caused a molecular phenotype consistent with senescence that was exacerbated by hypoxia, a common condition in COPD. Genetic variation may interact with hypoxia and contribute to variable severity of sarcopenia and skeletal muscle molecular senescence phenotype in COPD.
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Affiliation(s)
- Amy H. Attaway
- Department of Pulmonary MedicineCleveland ClinicClevelandOhioUSA
| | - Annette Bellar
- Department of Inflammation and ImmunityCleveland ClinicClevelandOhioUSA
| | - Nicole Welch
- Department of Inflammation and ImmunityCleveland ClinicClevelandOhioUSA
- Department of Gastroenterology and HepatologyCleveland ClinicClevelandOhioUSA
| | - Jinendiran Sekar
- Department of Gastroenterology and HepatologyCleveland ClinicClevelandOhioUSA
| | - Avinash Kumar
- Department of Gastroenterology and HepatologyCleveland ClinicClevelandOhioUSA
| | - Saurabh Mishra
- Department of Gastroenterology and HepatologyCleveland ClinicClevelandOhioUSA
| | - Umur Hatipoğlu
- Department of Pulmonary MedicineCleveland ClinicClevelandOhioUSA
| | - Merry‐Lynn McDonald
- Department of Medicine, Division of Pulmonary, Allergy, & Critical Care MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Elizabeth A. Regan
- Department of Medicine, Division of RheumatologyNational Jewish HealthDenverColoradoUSA
| | - Jonathan D. Smith
- Cardiovascular and Metabolic SciencesCleveland ClinicClevelandOhioUSA
| | - George Washko
- Department of PulmonaryBrigham and Women's HospitalBostonMassachusettsUSA
| | | | - Peter Bazeley
- Quantitative Health SciencesCleveland ClinicClevelandOhioUSA
| | - Joe Zein
- Department of Pulmonary MedicineCleveland ClinicClevelandOhioUSA
- Department of Inflammation and ImmunityCleveland ClinicClevelandOhioUSA
| | - Srinivasan Dasarathy
- Department of Inflammation and ImmunityCleveland ClinicClevelandOhioUSA
- Department of Gastroenterology and HepatologyCleveland ClinicClevelandOhioUSA
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9
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Henrot P, Dupin I, Schilfarth P, Esteves P, Blervaque L, Zysman M, Gouzi F, Hayot M, Pomiès P, Berger P. Main Pathogenic Mechanisms and Recent Advances in COPD Peripheral Skeletal Muscle Wasting. Int J Mol Sci 2023; 24:ijms24076454. [PMID: 37047427 PMCID: PMC10095391 DOI: 10.3390/ijms24076454] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 03/27/2023] [Accepted: 03/28/2023] [Indexed: 04/14/2023] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a worldwide prevalent respiratory disease mainly caused by tobacco smoke exposure. COPD is now considered as a systemic disease with several comorbidities. Among them, skeletal muscle dysfunction affects around 20% of COPD patients and is associated with higher morbidity and mortality. Although the histological alterations are well characterized, including myofiber atrophy, a decreased proportion of slow-twitch myofibers, and a decreased capillarization and oxidative phosphorylation capacity, the molecular basis for muscle atrophy is complex and remains partly unknown. Major difficulties lie in patient heterogeneity, accessing patients' samples, and complex multifactorial process including extrinsic mechanisms, such as tobacco smoke or disuse, and intrinsic mechanisms, such as oxidative stress, hypoxia, or systemic inflammation. Muscle wasting is also a highly dynamic process whose investigation is hampered by the differential protein regulation according to the stage of atrophy. In this review, we report and discuss recent data regarding the molecular alterations in COPD leading to impaired muscle mass, including inflammation, hypoxia and hypercapnia, mitochondrial dysfunction, diverse metabolic changes such as oxidative and nitrosative stress and genetic and epigenetic modifications, all leading to an impaired anabolic/catabolic balance in the myocyte. We recapitulate data concerning skeletal muscle dysfunction obtained in the different rodent models of COPD. Finally, we propose several pathways that should be investigated in COPD skeletal muscle dysfunction in the future.
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Affiliation(s)
- Pauline Henrot
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33604 Pessac, France
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, CIC 1401, F-33604 Pessac, France
- CHU de Bordeaux, Service d'Exploration Fonctionnelle Respiratoire, CIC 1401, Service de Pneumologie, F-33604 Pessac, France
| | - Isabelle Dupin
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33604 Pessac, France
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, CIC 1401, F-33604 Pessac, France
| | - Pierre Schilfarth
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33604 Pessac, France
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, CIC 1401, F-33604 Pessac, France
- CHU de Bordeaux, Service d'Exploration Fonctionnelle Respiratoire, CIC 1401, Service de Pneumologie, F-33604 Pessac, France
| | - Pauline Esteves
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33604 Pessac, France
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, CIC 1401, F-33604 Pessac, France
| | - Léo Blervaque
- PhyMedExp, INSERM-CNRS-Montpellier University, F-34090 Montpellier, France
| | - Maéva Zysman
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33604 Pessac, France
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, CIC 1401, F-33604 Pessac, France
- CHU de Bordeaux, Service d'Exploration Fonctionnelle Respiratoire, CIC 1401, Service de Pneumologie, F-33604 Pessac, France
| | - Fares Gouzi
- PhyMedExp, INSERM-CNRS-Montpellier University, CHRU Montpellier, F-34090 Montpellier, France
| | - Maurice Hayot
- PhyMedExp, INSERM-CNRS-Montpellier University, CHRU Montpellier, F-34090 Montpellier, France
| | - Pascal Pomiès
- PhyMedExp, INSERM-CNRS-Montpellier University, F-34090 Montpellier, France
| | - Patrick Berger
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33604 Pessac, France
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, CIC 1401, F-33604 Pessac, France
- CHU de Bordeaux, Service d'Exploration Fonctionnelle Respiratoire, CIC 1401, Service de Pneumologie, F-33604 Pessac, France
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Johansen VBI. Sarcopenia in chronic obstructive pulmonary disease: skeletal muscle gasping for air? J Physiol 2023; 601:883-885. [PMID: 36692139 DOI: 10.1113/jp284297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 01/19/2023] [Indexed: 01/25/2023] Open
Affiliation(s)
- Valdemar Brimnes Ingemann Johansen
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark.,Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen N, Denmark
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11
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Figueiredo VC. Muscle cells on a tight budget: cutting expenses during hypoxia. J Physiol 2023; 601:395-396. [PMID: 36627842 DOI: 10.1113/jp284240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 01/09/2023] [Indexed: 01/12/2023] Open
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12
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Bordoni B, Escher A, Compalati E, Mapelli L, Toccafondi A. The Importance of the Diaphragm in Neuromotor Function in the Patient with Chronic Obstructive Pulmonary Disease. Int J Chron Obstruct Pulmon Dis 2023; 18:837-848. [PMID: 37197600 PMCID: PMC10184771 DOI: 10.2147/copd.s404190] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 04/13/2023] [Indexed: 05/19/2023] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a constant and chronic narrowing of the respiratory airways, with numerous associated symptoms, not always related to the pathological adaptation of the lungs. Statistical projections show that COPD could become the third leading cause of death globally by 2030, with a significant increase in deaths by 2060. Skeletal muscle dysfunction, including the diaphragm, is one of the causes linked to the increase in mortality and hospitalization. Little emphasis is given by the scientific literature to the importance of the diaphragm towards functional neuromotor pathological expressions. The article reviews the adaptation of the skeletal muscles, with greater attention to the adaptations of the diaphragm, thereby highlighting the non-physiological variations that the main respiratory muscle undergoes and the neuromotor impairment found in COPD. The text could be an important reflection from a clinical and rehabilitation point of view, to direct greater attention to the function and adaptation of the diaphragm muscle.
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Affiliation(s)
- Bruno Bordoni
- Department of Cardiology, Institute of Hospitalization and Care with Scientific Address, Foundation Don Carlo Gnocchi IRCCS S Maria Nascente, Milano, Italy
- Correspondence: Bruno Bordoni, Email
| | - Allan Escher
- Anesthesiology/Pain Medicine, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Elena Compalati
- Department of Cardiology, Institute of Hospitalization and Care with Scientific Address, Foundation Don Carlo Gnocchi IRCCS S Maria Nascente, Milano, Italy
| | - Luca Mapelli
- Department of Cardiology, Institute of Hospitalization and Care with Scientific Address, Foundation Don Carlo Gnocchi IRCCS S Maria Nascente, Milano, Italy
| | - Anastasia Toccafondi
- Department of Cardiology, Institute of Hospitalization and Care with Scientific Address, Foundation Don Carlo Gnocchi IRCCS S Maria Nascente, Milano, Italy
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