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Gnaiger E. Complex II ambiguities-FADH 2 in the electron transfer system. J Biol Chem 2024; 300:105470. [PMID: 38118236 PMCID: PMC10772739 DOI: 10.1016/j.jbc.2023.105470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 11/01/2023] [Accepted: 11/06/2023] [Indexed: 12/22/2023] Open
Abstract
The prevailing notion that reduced cofactors NADH and FADH2 transfer electrons from the tricarboxylic acid cycle to the mitochondrial electron transfer system creates ambiguities regarding respiratory Complex II (CII). CII is the only membrane-bound enzyme in the tricarboxylic acid cycle and is part of the electron transfer system of the mitochondrial inner membrane feeding electrons into the coenzyme Q-junction. The succinate dehydrogenase subunit SDHA of CII oxidizes succinate and reduces the covalently bound prosthetic group FAD to FADH2 in the canonical forward tricarboxylic acid cycle. However, several graphical representations of the electron transfer system depict FADH2 in the mitochondrial matrix as a substrate to be oxidized by CII. This leads to the false conclusion that FADH2 from the β-oxidation cycle in fatty acid oxidation feeds electrons into CII. In reality, dehydrogenases of fatty acid oxidation channel electrons to the Q-junction but not through CII. The ambiguities surrounding Complex II in the literature and educational resources call for quality control, to secure scientific standards in current communications of bioenergetics, and ultimately support adequate clinical applications. This review aims to raise awareness of the inherent ambiguity crisis, complementing efforts to address the well-acknowledged issues of credibility and reproducibility.
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Kushwaha AD, Varshney R, Saraswat D. Effect of hypobaric hypoxia on the fiber type transition of skeletal muscle: a synergistic therapy of exercise preconditioning with a nanocurcumin formulation. J Physiol Biochem 2023:10.1007/s13105-023-00965-1. [PMID: 37147493 DOI: 10.1007/s13105-023-00965-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 04/26/2023] [Indexed: 05/07/2023]
Abstract
Hypobaric hypoxia (HH) leads to various adverse effects on skeletal muscles, including atrophy and reduced oxidative work capacity. However, the effects of HH on muscle fatigue resistance and myofiber remodeling are largely unexplored. Therefore, the present study aimed to explore the impact of HH on slow-oxidative fibers and to evaluate the ameliorative potential of exercise preconditioning and nanocurcumin formulation on muscle anti-fatigue ability. C2C12 cells (murine myoblasts) were used to assess the effect of hypoxia (0.5%, 24 h) with and without the nanocurcumin formulation (NCF) on myofiber phenotypic conversion. To further validate this hypothesis, male Sprague Dawley rats were exposed to a simulated HH (7620 m) for 7 days, along with NCF administration and/or exercise training. Both in vitro and in vivo studies revealed a significant reduction in slow-oxidative fibers (p < 0.01, 61% vs. normoxia control) under hypoxia. There was also a marked decrease in exhaustion time (p < 0.01, 65% vs. normoxia) in hypoxia control rats, indicating a reduced work capacity. Exercise preconditioning along with NCF supplementation significantly increased the slow-oxidative fiber proportion and exhaustion time while maintaining mitochondrial homeostasis. These findings suggest that HH leads to an increased transition of slow-oxidative fibers to fast glycolytic fibers and increased muscular fatigue. Administration of NCF in combination with exercise preconditioning restored this myofiber remodeling and improved muscle anti-fatigue ability.
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Affiliation(s)
- Asha D Kushwaha
- Pathophysiology and Disruptive Technologies, Defense Institute of Physiology and Allied Sciences, Defense Research and Development Organization, Delhi, India, 110054
| | - Rajeev Varshney
- Pathophysiology and Disruptive Technologies, Defense Institute of Physiology and Allied Sciences, Defense Research and Development Organization, Delhi, India, 110054
| | - Deepika Saraswat
- Pathophysiology and Disruptive Technologies, Defense Institute of Physiology and Allied Sciences, Defense Research and Development Organization, Delhi, India, 110054.
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3
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Smith KLM, Swiderska A, Lock MC, Graham L, Iswari W, Choudhary T, Thomas D, Kowash HM, Desforges M, Cottrell EC, Trafford AW, Giussani DA, Galli GLJ. Chronic developmental hypoxia alters mitochondrial oxidative capacity and reactive oxygen species production in the fetal rat heart in a sex-dependent manner. J Pineal Res 2022; 73:e12821. [PMID: 35941749 PMCID: PMC9540814 DOI: 10.1111/jpi.12821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/28/2022] [Accepted: 08/03/2022] [Indexed: 11/29/2022]
Abstract
Insufficient oxygen supply (hypoxia) during fetal development leads to cardiac remodeling and a predisposition to cardiovascular disease in later life. Previous work has shown hypoxia causes oxidative stress in the fetal heart and alters the activity and expression of mitochondrial proteins in a sex-dependent manner. However, the functional effects of these modifications on mitochondrial respiration remain unknown. Furthermore, while maternal antioxidant treatments are emerging as a promising new strategy to protect the hypoxic fetus, whether these treatments convey similar protection to cardiac mitochondria in the male or female fetus has not been investigated. Therefore, using an established rat model, we measured the sex-dependent effects of gestational hypoxia and maternal melatonin treatment on fetal cardiac mitochondrial respiration, reactive oxygen species (ROS) production, and lipid peroxidation. Pregnant Wistar rats were subjected to normoxia or hypoxia (13% oxygen) during gestational days (GDs) 6-20 (term ~22 days) with or without melatonin treatment (5 µg/ml in maternal drinking water). On GD 20, mitochondrial aerobic respiration and H2 O2 production were measured in fetal heart tissue, together with lipid peroxidation and citrate synthase (CS) activity. Gestational hypoxia reduced maternal body weight gain (p < .01) and increased placental weight (p < .05) but had no effect on fetal weight or litter size. Cardiac mitochondria from male but not female fetuses of hypoxic pregnancy had reduced respiratory capacity at Complex II (CII) (p < .05), and an increase in H2 O2 production/O2 consumption (p < .05) without any changes in lipid peroxidation. CS activity was also unchanged in both sexes. Despite maternal melatonin treatment increasing maternal and fetal plasma melatonin concentration (p < .001), melatonin treatment had no effect on any of the mitochondrial parameters investigated. To conclude, we show that gestational hypoxia leads to ROS generation from the mitochondrial electron transport chain and affects fetal cardiac mitochondrial respiration in a sex-dependent manner. We also show that maternal melatonin treatment had no effect on these relationships, which has implications for the development of future therapies for hypoxic pregnancies.
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Affiliation(s)
- Kerri L. M. Smith
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
| | - Agnieszka Swiderska
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
| | - Mitchell C. Lock
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
| | - Lucia Graham
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
| | - Wulan Iswari
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
| | - Tashi Choudhary
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
| | - Donna Thomas
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
| | - Hager M. Kowash
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
| | - Michelle Desforges
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
| | - Elizabeth C. Cottrell
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
| | - Andrew W. Trafford
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
| | - Dino A. Giussani
- Department of Physiology Development and NeuroscienceUniversity of CambridgeCambridgeUK
| | - Gina L. J. Galli
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
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4
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Ağaşcıoğlu E, Çolak R, Çakatay U. Redox status biomarkers in the fast-twitch extensor digitorum longus resulting from the hypoxic exercise. NAGOYA JOURNAL OF MEDICAL SCIENCE 2022; 84:433-447. [PMID: 35967949 PMCID: PMC9350571 DOI: 10.18999/nagjms.84.2.433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 11/01/2021] [Indexed: 11/29/2022]
Abstract
The fast-twitch muscle may be affected from over-produced reactive oxygen species (ROS) during hypoxia/hypoxic exercise. The study aims to investigate redox status biomarkers in the fast-twitch extensor digitorum longus (EDL) muscle after hypoxic exercise. Male Sprague Dawley rats (eight-week-old) were randomly divided into six groups of the experimental "live high train high (LHTH), live high train low (LHTL) and live low train low (LLTL)" and their respective controls. Before the EDLs' extraction, the animals exercised for a 4-week familiarization period, then they exercised for four-weeks at different altitudes. The LHTH group had higher ratios of lipid hydroperoxides (LHPs) than the experimental groups of LHTL (p=0.004) and LLTL (p=0.002), while having no difference than its control 'LH'. Similarly, a higher percentage of advanced oxidation protein products (AOPP) was determined in the LHTH than the LHTL (p=0.041) and LLTL (p=0.048). Furthermore, oxidation of thiol fractions was the lowest in the LHTH and LH. However, redox biomarkers and thiol fractions illustrated no significant change in the LHTL and LLTL that might ensure redox homeostasis due to higher oxygen consumption. The study shows that not hypoxic exercise/exercise, but hypoxia might itself lead to a redox imbalance in the fast-twitch EDL muscle.
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Affiliation(s)
- Eda Ağaşcıoğlu
- Department of Recreation, Faculty of Sports Sciences, Lokman Hekim University, Ankara, Turkey
| | - Rıdvan Çolak
- Department of Physical Education and Sports, Ardahan University, Ardahan, Turkey
| | - Ufuk Çakatay
- Department of Medical Biochemistry, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
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Varghese T, Dasgupta S, Anand G, Rejish Kumar VJ, Sahu NP, Pal AK, Puthiyottil M. Dietary arginine attenuates hypoxia- induced HIF expression, metabolic responses and oxidative stress in Indian Major Carp, Cirrhinus mrigala. Comp Biochem Physiol B Biochem Mol Biol 2022; 259:110714. [PMID: 35026416 DOI: 10.1016/j.cbpb.2022.110714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 12/27/2021] [Accepted: 01/04/2022] [Indexed: 02/07/2023]
Abstract
Hypoxia is a common stressor in aquaculture systems, which causes severe physiological disturbances, ultimately leading to mortality or reduced productivity. Arginine, as a precursor of NO, has a role in enhancing oxygen delivery. Thus, an experiment was conducted to evaluate the effect of dietary arginine (Arg) in Cirrhinus mrigala exposed to hypoxia. The fish were fed with different levels of arginine for 60 days and exposed for 72 h to a sublethal level of hypoxia (0.50 ± 0.16 mg/L dissolved oxygen [DO]). The six treatment groups with three replicates were N0 (0% Arg + Normoxia), H0 (0% Arg + Hypoxia), N0.7 (0.70% Arg + Normoxia), H0.7 (0.70% Arg + Hypoxia), N1.4 (1.40% Arg + Normoxia), H1.4 (1.40% Arg + Hypoxia). Eighteen experimental units with twelve animals (5.8 ± 0.18 g) each were used for the trial.The results indicated that supplementation of arginine at 0.7 and 1.4% enhanced the hypoxia tolerance time, although the high dose (1.4%) did not yield any further increments. The exposure to hypoxia up-regulated Hypoxia Inducible Factor (HIF)-1α mRNA expression and supplementation of arginine significantly decreased hypoxia induced up-regulation of HIF at 1.4%. Arginine supplementation partially or completely normalised the hypoxia induced changes in the metabolic enzymes of C. mrigala. The fish exposed to hypoxic conditions exhibited significantly higher (P < 0.05) lipid peroxidation levels than those maintained under normoxic conditions, while arginine feeding significant in reducing lipid peroxidation. Antioxidant enzyme activities were significantly higher (P < 0.05) in hypoxia-exposed carp, indicating increased oxidative stress during the hypoxic exposure, that was improved in Arg-supplemented groups. However, arginine did not modulate erythrocyte countsalthough itreduced the erythrocyte fragility. We conclude arginine supplementation is effective in ameliorating hypoxia induced metabolic alterations and improving antioxidant defences in fish.
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Affiliation(s)
- Tincy Varghese
- ICAR-Central Institute of Fisheries Education (CIFE), Mumbai 400061, India.
| | - Subrata Dasgupta
- ICAR-Central Institute of Fisheries Education (CIFE), Mumbai 400061, India
| | - Garima Anand
- ICAR-Central Institute of Fisheries Education (CIFE), Mumbai 400061, India
| | - V J Rejish Kumar
- Kerala University of Fisheries and Ocean Studies, Kochi, Kerala 682 506, India
| | | | - Asim Kumar Pal
- ICAR-Central Institute of Fisheries Education (CIFE), Mumbai 400061, India
| | - Mishal Puthiyottil
- ICAR-Central Inland Fisheries Research Institute, Kolkata 700 120, India.
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Parshukova OI, Varlamova NG, Potolitsyna NN, Lyudinina AY, Bojko ER. Features of Metabolic Support of Physical Performance in Highly Trained Cross-Country Skiers of Different Qualifications during Physical Activity at Maximum Load. Cells 2021; 11:cells11010039. [PMID: 35011601 PMCID: PMC8750590 DOI: 10.3390/cells11010039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/17/2021] [Accepted: 12/21/2021] [Indexed: 11/27/2022] Open
Abstract
The purpose of our study was to identify the features of metabolic regulation in highly trained cross-country skiers of different qualifications at different stages of the maximum load test. We examined 124 highly trained cross-country skiers (male, ages 17–24). The group consisted of two subgroups based on their competition performance: 61 nonelite athletes (Group I) and 63 elite athletes (group II), who were current members of the national team of the Komi Republic and Russia. The bicycle ergometer test was performed by using the OxyconPro system (Erich Jaeger, Hoechberg, Germany). All the examined athletes performed the exercise test on a cycle ergometer “until exhaustion”. The results of our research indicate that the studied groups of athletes with high, but different levels of sports qualifications are a convenient model for studying the molecular mechanisms of adaptation to physical loads of maximum intensity. Athletes of higher qualifications reveal additional adaptive mechanisms of metabolic regulation, which is manifested in the independence of serum lactate indicators under conditions of submaximal and maximum power from maximal oxygen uptake, and they have an NO-dependent mechanism for regulating lactate levels during aerobic exercise, including work at the anaerobic threshold.
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Galli GLJ, Ruhr IM, Crossley J, Crossley DA. The Long-Term Effects of Developmental Hypoxia on Cardiac Mitochondrial Function in Snapping Turtles. Front Physiol 2021; 12:689684. [PMID: 34262478 PMCID: PMC8273549 DOI: 10.3389/fphys.2021.689684] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/03/2021] [Indexed: 01/05/2023] Open
Abstract
It is well established that adult vertebrates acclimatizing to hypoxic environments undergo mitochondrial remodeling to enhance oxygen delivery, maintain ATP, and limit oxidative stress. However, many vertebrates also encounter oxygen deprivation during embryonic development. The effects of developmental hypoxia on mitochondrial function are likely to be more profound, because environmental stress during early life can permanently alter cellular physiology and morphology. To this end, we investigated the long-term effects of developmental hypoxia on mitochondrial function in a species that regularly encounters hypoxia during development-the common snapping turtle (Chelydra serpentina). Turtle eggs were incubated in 21% or 10% oxygen from 20% of embryonic development until hatching, and both cohorts were subsequently reared in 21% oxygen for 8 months. Ventricular mitochondria were isolated, and mitochondrial respiration and reactive oxygen species (ROS) production were measured with a microrespirometer. Compared to normoxic controls, juvenile turtles from hypoxic incubations had lower Leak respiration, higher P:O ratios, and reduced rates of ROS production. Interestingly, these same attributes occur in adult vertebrates that acclimatize to hypoxia. We speculate that these adjustments might improve mitochondrial hypoxia tolerance, which would be beneficial for turtles during breath-hold diving and overwintering in anoxic environments.
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Affiliation(s)
- Gina L. J. Galli
- Faculty of Biology, Medicine, and Health, School of Medical Sciences, The University of Manchester, Manchester, United Kingdom
| | - Ilan M. Ruhr
- Faculty of Biology, Medicine, and Health, School of Medical Sciences, The University of Manchester, Manchester, United Kingdom
| | - Janna Crossley
- Developmental Integrative Biology Research Group, Department of Biological Sciences, University of North Texas, Denton, TX, United States
| | - Dane A. Crossley
- Developmental Integrative Biology Research Group, Department of Biological Sciences, University of North Texas, Denton, TX, United States
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Ma Y, Ga Q, Ge RL, Ma S. Correlations Between Intestinal Microbial Community and Hematological Profile in Native Tibetans and Han Immigrants. Front Microbiol 2021; 12:615416. [PMID: 34234749 PMCID: PMC8257080 DOI: 10.3389/fmicb.2021.615416] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 05/21/2021] [Indexed: 12/27/2022] Open
Abstract
Hematological features are one of the best-known aspects of high-altitude adaptation in Tibetans. However, it is still unclear whether the intestinal microbiota is associated with the hematology profile. In this study, routine blood tests and 16S rRNA gene sequencing were used to investigate the differences in the intestinal microbiota and hematological parameters of native Tibetan herders and Han immigrants sampled at 3,900 m. The blood test results suggested that the platelet counts (PLTs) were significantly higher in native Tibetans than the Han immigrants. The feces of the native Tibetans had significantly greater microbial diversity (more different species: Simpson’s and Shannon’s indices) than that of the Han immigrants. The native Tibetans also had a different fecal microbial community structure than the Han immigrants. A Bray–Curtis distance-based redundancy analysis and envfit function test showed that body mass index (BMI) and PLT were significant explanatory variables that correlated with the fecal microbial community structure in native Tibetans. Spearman’s correlation analysis showed that Megamonas correlated positively with BMI, whereas Bifidobacterium correlated negatively with BMI. Alistipes and Parabacteroides correlated positively with the PLT. Succinivibrio correlated positively with SpO2. Intestinibacter correlated negatively with the red blood cell count, hemoglobin, and hematocrit (HCT). Romboutsia correlated negatively with HCT, whereas Phascolarctobacterium correlated positively with HCT. A functional analysis showed that the functional capacity of the gut microbial community in the native Tibetans was significantly related to carbohydrate metabolism. These findings suggest that the hematological profile is associated with the fecal microbial community, which may influence the high-altitude adaptation/acclimatization of Tibetans.
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Affiliation(s)
- Yan Ma
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China.,Key Laboratory for Application of High Altitude Medicine in Qinghai Province, Qinghai University, Xining, China.,Qinghai-Utah Joint Research Key Lab for High Altitude Medicine, Qinghai University Medical College, Xining, China
| | - Qin Ga
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China.,Key Laboratory for Application of High Altitude Medicine in Qinghai Province, Qinghai University, Xining, China.,Qinghai-Utah Joint Research Key Lab for High Altitude Medicine, Qinghai University Medical College, Xining, China
| | - Ri-Li Ge
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China.,Key Laboratory for Application of High Altitude Medicine in Qinghai Province, Qinghai University, Xining, China.,Qinghai-Utah Joint Research Key Lab for High Altitude Medicine, Qinghai University Medical College, Xining, China
| | - Shuang Ma
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China.,Key Laboratory for Application of High Altitude Medicine in Qinghai Province, Qinghai University, Xining, China.,Qinghai-Utah Joint Research Key Lab for High Altitude Medicine, Qinghai University Medical College, Xining, China
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9
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Targeting the Mild-Hypoxia Driving Force for Metabolic and Muscle Transcriptional Reprogramming of Gilthead Sea Bream ( Sparus aurata) Juveniles. BIOLOGY 2021; 10:biology10050416. [PMID: 34066667 PMCID: PMC8151949 DOI: 10.3390/biology10050416] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/28/2021] [Accepted: 05/04/2021] [Indexed: 01/08/2023]
Abstract
Simple Summary Reduced oxygen availability generates a number of adaptive features across all the animal kingdom, and the goal of this study was targeting the mild-hypoxia driving force for metabolic and muscle transcriptional reprogramming of gilthead sea bream juveniles. Attention was focused on blood metabolic and muscle transcriptomic landmarks before and after exhaustive exercise. Our results after mild-hypoxia conditioning highlighted an increased contribution of lipid metabolism to whole energy supply to preserve the aerobic energy production, a better swimming performance regardless of changes in feed intake, as well as reduced protein turnover and improved anaerobic fitness with the restoration of normoxia. Abstract On-growing juveniles of gilthead sea bream were acclimated for 45 days to mild-hypoxia (M-HYP, 40–60% O2 saturation), whereas normoxic fish (85–90% O2 saturation) constituted two different groups, depending on if they were fed to visual satiety (control fish) or pair-fed to M-HYP fish. Following the hypoxia conditioning period, all fish were maintained in normoxia and continued to be fed until visual satiation for 3 weeks. The time course of hypoxia-induced changes was assessed by changes in blood metabolic landmarks and muscle transcriptomics before and after exhaustive exercise in a swim tunnel respirometer. In M-HYP fish, our results highlighted a higher contribution of aerobic metabolism to whole energy supply, shifting towards a higher anaerobic fitness following normoxia restoration. Despite these changes in substrate preference, M-HYP fish shared a persistent improvement in swimming performance with a higher critical speed at exercise exhaustion. The machinery of muscle contraction and protein synthesis and breakdown was also largely altered by mild-hypoxia conditioning, contributing this metabolic re-adjustment to the positive regulation of locomotion and to the catch-up growth response during the normoxia recovery period. Altogether, these results reinforce the presence of large phenotypic plasticity in gilthead sea bream, and highlights mild-hypoxia as a promising prophylactic measure to prepare these fish for predictable stressful events.
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Margolis LM, Karl JP, Wilson MA, Coleman JL, Ferrando AA, Young AJ, Pasiakos SM. Metabolomic profiles are reflective of hypoxia-induced insulin resistance during exercise in healthy young adult males. Am J Physiol Regul Integr Comp Physiol 2021; 321:R1-R11. [PMID: 33949213 PMCID: PMC8321788 DOI: 10.1152/ajpregu.00076.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Hypoxia-induced insulin resistance appears to suppress exogenous glucose oxidation during metabolically matched aerobic exercise during acute (<8 h) high-altitude (HA) exposure. However, a better understanding of this metabolic dysregulation is needed to identify interventions to mitigate these effects. The objective of this study was to determine if differences in metabolomic profiles during exercise at sea level (SL) and HA are reflective of hypoxia-induced insulin resistance. Native lowlanders (n = 8 males) consumed 145 g (1.8 g/min) of glucose while performing 80-min of metabolically matched treadmill exercise at SL (757 mmHg) and HA (460 mmHg) after 5-h exposure. Exogenous glucose oxidation and glucose turnover were determined using indirect calorimetry and dual tracer technique ([13C]glucose and [6,6-2H2]glucose). Metabolite profiles were analyzed in serum as change (Δ), calculated by subtracting postprandial/exercised state SL (ΔSL) and HA (ΔHA) from fasted, rested conditions at SL. Compared with SL, exogenous glucose oxidation, glucose rate of disappearance, and glucose metabolic clearance rate (MCR) were lower (P < 0.05) during exercise at HA. One hundred and eighteen metabolites differed between ΔSL and ΔHA (P < 0.05, Q < 0.10). Differences in metabolites indicated increased glycolysis, tricarboxylic acid cycle, amino acid catabolism, oxidative stress, and fatty acid storage, and decreased fatty acid mobilization for ΔHA. Branched-chain amino acids and oxidative stress metabolites, Δ3-methyl-2-oxobutyrate (r = -0.738) and Δγ-glutamylalanine (r = -0.810), were inversely associated (P < 0.05) with Δexogenous glucose oxidation. Δ3-Hydroxyisobutyrate (r = -0.762) and Δ2-hydroxybutyrate/2-hydroxyisobutyrate (r = -0.738) were inversely associated (P < 0.05) with glucose MCR. Coupling global metabolomics and glucose kinetic data suggest that the underlying cause for diminished exogenous glucose oxidative capacity during aerobic exercise is acute hypoxia-mediated peripheral insulin resistance.
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Affiliation(s)
- Lee M Margolis
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - J Philip Karl
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Marques A Wilson
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Julie L Coleman
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts.,Oak Ridge Institute of Science and Education, Oak Ridge, Tennessee
| | - Arny A Ferrando
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Andrew J Young
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts.,Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland
| | - Stefan M Pasiakos
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
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11
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Sharma S, Singh Y, Sandhir R, Singh S, Ganju L, Kumar B, Varshney R. Mitochondrial DNA mutations contribute to high altitude pulmonary edema via increased oxidative stress and metabolic reprogramming during hypobaric hypoxia. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148431. [PMID: 33862004 DOI: 10.1016/j.bbabio.2021.148431] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 03/27/2021] [Accepted: 04/07/2021] [Indexed: 10/21/2022]
Abstract
High altitude pulmonary edema (HAPE) is experienced by non-acclimatized sea level individuals on exposure to high altitude hypoxic conditions. Available evidence suggests that genetic factors and perturbed mitochondrial redox status may play an important role in HAPE pathophysiology. However, the precise mechanism has not been fully understood. In the present study, sequencing of mitochondrial DNA (mtDNA) from HAPE subjects and acclimatized controls was performed to identify pathogenic mutations and to determine their role in HAPE. Hypobaric hypoxia induced oxidative stress and metabolic alterations were also assessed in HAPE subjects. mtDNA copy number, mitochondrial oxidative phosphorylation (mtOXPHOS) activity, mitochondrial biogenesis were measured to determine mitochondrial functions. The data revealed that the mutations in Complex I genes affects the secondary structure of protein in HAPE subjects. Further, increased oxidative stress during hypobaric hypoxia, reduced mitochondrial biogenesis and mtOXPHOS activity induced metabolic reprogramming appears to contribute to mitochondrial dysfunctions in HAPE individuals. Haplogroup analysis suggests that mtDNA haplogroup H2a2a1 has potential contribution in the pathobiology of HAPE in lowlanders. This study also suggests contribution of altered mitochondrial functions in HAPE susceptibility.
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Affiliation(s)
- Swati Sharma
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India; Department of Biochemistry, Basic Medical Sciences Block II, Panjab University, Chandigarh 160014, India
| | - Yamini Singh
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India.
| | - Rajat Sandhir
- Department of Biochemistry, Basic Medical Sciences Block II, Panjab University, Chandigarh 160014, India
| | - Sayar Singh
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India
| | - Lilly Ganju
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India
| | - Bhuvnesh Kumar
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India
| | - Rajeev Varshney
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India
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Gaur P, Prasad S, Kumar B, Sharma SK, Vats P. High-altitude hypoxia induced reactive oxygen species generation, signaling, and mitigation approaches. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2021; 65:601-615. [PMID: 33156424 DOI: 10.1007/s00484-020-02037-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 10/05/2020] [Accepted: 10/20/2020] [Indexed: 06/11/2023]
Abstract
Homeostasis between pro-oxidants and anti-oxidants is necessary for aerobic life, which if perturbed and shifted towards pro-oxidants results in oxidative stress. It is generally agreed that reactive oxygen species (ROS) production is accelerated with mountainous elevation, which may play a role in spawning serious health crisis. Exposure to increasing terrestrial altitude leads to a reduction in ambient O2 availability in cells producing a series of hypoxic oxidative stress reactions and altering the redox balance in humans. Enormous literature on redox signaling drove research activity towards understanding the role of oxidative stress under normal and challenging conditions like high-altitude hypoxia which grounds for disturbed redox signaling. Excessive ROS production and accumulation of free radicals in cells and tissues can cause various pulmonary, cardiovascular, and metabolic pathophysiological conditions. In order to counteract this oxidative stress and maintain the balance of pro-oxidants and anti-oxidants, an anti-oxidant system exists in the human body, which, however, gets surpassed by elevated ROS levels, but can be strengthened through the use of anti-oxidant supplements. Such cumulative studies of fundamentals on a global concept like oxidative stress and role of anti-oxidants can act as a foundation to further smoothen for researchers to study over health, disease, and other pathophysiological conditions. This review highlights the interconnection between high altitude and oxidative stress and the role of anti-oxidants to protect cells from oxidative damages and to lower the risk of altitude-associated sickness.
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Affiliation(s)
- Priya Gaur
- Endocrinology & Metabolism Division, Defence Institute of Physiology and Allied Sciences (DIPAS), DRDO, Lucknow Road, Timarpur, Delhi, 110054,, India
| | - Suchita Prasad
- Department of Chemistry, University of Delhi, Delhi, 110007,, India
| | - Bhuvnesh Kumar
- Endocrinology & Metabolism Division, Defence Institute of Physiology and Allied Sciences (DIPAS), DRDO, Lucknow Road, Timarpur, Delhi, 110054,, India
| | - Sunil K Sharma
- Department of Chemistry, University of Delhi, Delhi, 110007,, India.
| | - Praveen Vats
- Endocrinology & Metabolism Division, Defence Institute of Physiology and Allied Sciences (DIPAS), DRDO, Lucknow Road, Timarpur, Delhi, 110054,, India.
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Çolak R, Ağaşcıoğlu E, Çakatay U. "Live High Train Low" Hypoxic Training Enhances Exercise Performance with Efficient Redox Homeostasis in Rats' Soleus Muscle. High Alt Med Biol 2020; 22:77-86. [PMID: 32960081 DOI: 10.1089/ham.2020.0136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Çolak, Rıdvan, Eda Ağaşcıoğlu, and Ufuk Çakatay. "Live high train low" hypoxic training enhances exercise performance with efficient redox homeostasis in rats' soleus muscle. High Alt Med Biol. 22:77-86, 2021. Background: Different types of hypoxic training have been performed to improve exercise performance. Although both "live high train high" and "live high train low" techniques are commonly performed, it is still obscure as to which one is more beneficial. Materials and Methods: Eight-week-old male Sprague-Dawley rats were randomly divided into aforementioned experimental groups. After a familiarization exercise (4-week, ∼15-30 minutes/day) at normoxia, all rats exercised (4-week, ∼35 minutes/day) at hypoxia with their pre-evaluated maximal aerobic velocity test. The soleus was extracted after the test following 2 days of resting. Results: The live high trained low group displayed better performance than the live high trained high (p = 0.031) and the live low trained low (p = 0.017) groups. Redox status biomarkers were higher in the live high trained high group except for thiols, which were illustrated with no difference among the groups. Further, contrary to total and protein thiols (r = 0.57, p = 0.037; r = 0.55, p = 0.042 respectively), other redox status biomarkers were observed to be negatively correlated to exercise performance. Conclusions: The live high trained low group could consume more oxygen during exercise, which might lead to having a better chance to ensure cellular redox homeostasis. Therefore, this group could ensure an optimum exercise performance and anabolic metabolism.
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Affiliation(s)
- Rıdvan Çolak
- Department of Physical Education and Sports, Ardahan University, Ardahan, Turkey
| | - Eda Ağaşcıoğlu
- Department of Recreation, Faculty of Sports Sciences, Lokman Hekim University, Ankara, Turkey
| | - Ufuk Çakatay
- Department of Medical Biochemistry, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
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Effects of Dietary Nitrates on Time Trial Performance in Athletes with Different Training Status: Systematic Review. Nutrients 2020; 12:nu12092734. [PMID: 32911636 PMCID: PMC7551808 DOI: 10.3390/nu12092734] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 09/04/2020] [Indexed: 12/14/2022] Open
Abstract
Much research has been done in sports nutrition in recent years as the demand for performance-enhancing substances increases. Higher intake of nitrates from the diet can increase the bioavailability of nitric oxide (NO) via the nitrate-nitrite-NO pathway. Nevertheless, the increased availability of NO does not always lead to improved performance in some individuals. This review aims to evaluate the relationship between the athlete's training status and the change in time trial performance after increased dietary nitrate intake. Articles indexed by Scopus and PubMed published from 2015 to 2019 were reviewed. Thirteen articles met the eligibility criteria: clinical trial studies on healthy participants with different training status (according to VO2max), conducting time trial tests after dietary nitrate supplementation. The PRISMA guidelines were followed to process the review. We found a statistically significant relationship between VO2max and ergogenicity in time trial performance using one-way ANOVA (p = 0.001) in less-trained athletes (VO2 < 55 mL/kg/min). A strong positive correlation was observed in experimental situations using a chronic supplementation protocol but not in acute protocol situations. In the context of our results and recent histological observations of muscle fibres, there might be a fibre-type specific role in nitric oxide production and, therefore, supplement of ergogenicity.
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Hernandez‐Gerez E, Dall’Angelo S, Collinson JM, Fleming IN, Parson SH. Widespread tissue hypoxia dysregulates cell and metabolic pathways in SMA. Ann Clin Transl Neurol 2020; 7:1580-1593. [PMID: 32790171 PMCID: PMC7480929 DOI: 10.1002/acn3.51134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 07/01/2020] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE The purpose of the study was to determine the extent and role of systemic hypoxia in the pathogenesis of spinal muscular atrophy (SMA). METHODS Hypoxia was assayed in vivo in early-symptomatic (postnatal day 5) SMA-model mice by pimonidazole and [18 F]-Fluoroazomycin arabinoside injections, which accumulate in hypoxic cells, followed by immunohistochemistry and tracer biodistribution evaluation. Glucose uptake in hypoxic cells was assayed by [18 F]-Fluorodeoxyglucose labeling. In vitro knockdown of Survival Motor Neuron (SMN) was performed on motor neurons and lactate metabolism measured biochemically, whereas cell cycle progression and cell death were assayed by flow cytometry. RESULTS All assays found significant levels of hypoxia in multiple organ systems in early symptomatic SMA mouse pups, except aerated tissues such as skin and lungs. This was accompanied by significantly increased glucose uptake in many affected organs, consistent with a metabolic hypoxia response. SMN protein levels were shown to vary widely between motor neuron precursors in vitro, and those with lower levels were most susceptible to cell death. In addition, SMA-model motor neurons were particularly sensitive to hypoxia, with reduced ability to transport lactate out of the cell in hypoxic culture, and a failure in normal cell cycle progression. INTERPRETATION Not only is there widespread tissue hypoxia and multi-organ cellular hypoxic response in SMA model mice, but SMA-model motor neurons are especially susceptible to that hypoxia. The data support the hypothesis that vascular defects leading to hypoxia are a significant contributor to disease progression in SMA, and offer a route for combinatorial, non-SMN related therapy.
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Affiliation(s)
- Elena Hernandez‐Gerez
- Institute of Medical SciencesSchool of MedicineMedical Sciences and NutritionUniversity of AberdeenForesterhill, AberdeenAB25 2ZDUK
- Euan Macdonald Centre for Motor Neurone Disease ResearchUniversity of EdinburghChancellor's BuildingEdinburghEH16 4SBUK
| | - Sergio Dall’Angelo
- Institute of Medical SciencesSchool of MedicineMedical Sciences and NutritionUniversity of AberdeenForesterhill, AberdeenAB25 2ZDUK
- John Mallard Scottish PET CentreUniversity of AberdeenForesterhillAB25 2ZDUK
| | - Jon M. Collinson
- Institute of Medical SciencesSchool of MedicineMedical Sciences and NutritionUniversity of AberdeenForesterhill, AberdeenAB25 2ZDUK
| | - Ian N. Fleming
- Institute of Medical SciencesSchool of MedicineMedical Sciences and NutritionUniversity of AberdeenForesterhill, AberdeenAB25 2ZDUK
| | - Simon H. Parson
- Institute of Medical SciencesSchool of MedicineMedical Sciences and NutritionUniversity of AberdeenForesterhill, AberdeenAB25 2ZDUK
- Euan Macdonald Centre for Motor Neurone Disease ResearchUniversity of EdinburghChancellor's BuildingEdinburghEH16 4SBUK
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16
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Feng S, Ma J, Long K, Zhang J, Qiu W, Li Y, Jin L, Wang X, Jiang A, Liu L, Xiao W, Li X, Tang Q, Li M. Comparative microRNA Transcriptomes in Domestic Goats Reveal Acclimatization to High Altitude. Front Genet 2020; 11:809. [PMID: 32849809 PMCID: PMC7411263 DOI: 10.3389/fgene.2020.00809] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 07/06/2020] [Indexed: 01/30/2023] Open
Abstract
High-altitude acclimatization is a representative example of vertebrates' acclimatization to harsh and extreme environments. Previous studies reported sufficient evidence for a molecular genetic basis of high-altitude acclimatization, and genomic patterns of genetic variation among populations and species have been widely elucidated in recent years. However, understanding of the miRNA role in high-altitude acclimatization have lagged behind, especially in non-model species. To investigate miRNA expression alterations of goats that were induced by high-altitude stress, we performed comparative miRNA transcriptome analysis on six hypoxia-sensitive tissues (heart, kidney, liver, lung, skeletal muscle, and spleen) in two goat populations from distinct altitudes (600 and 3000 m). We obtained the expression value of 1391 mature miRNAs and identified 138 differentially expressed (DE) miRNAs between high and low altitudes. Combined with tissue specificity analysis, we illustrated alterations of expression levels among altitudes and tissues, and found that there were coexisting tissue-specific and -conserved mechanisms for hypoxia acclimatization. Notably, the interplay between DE miRNA and DE target genes strongly indicated post-transcriptional regulation in the hypoxia inducible factor 1, insulin, and p53 signaling pathways, which might play significant roles in high-altitude acclimatization in domestic goats. It's also worth noting that we experimentally confirmed miR-106a-5p to have a negative regulation effect on angiogenesis by directly targeting FLT-1. These results provide insight into the complicated miRNA expression patterns and regulatory mechanisms of high-altitude acclimatization in domestic goats.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Qianzi Tang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Mingzhou Li
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
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Varghese T, Rejish Kumar VJ, Anand G, Dasgupta S, Pal AK. Dietary GABA enhances hypoxia tolerance of a bottom-dwelling carp, Cirrhinus mrigala by modulating HIF-1α, thyroid hormones and metabolic responses. FISH PHYSIOLOGY AND BIOCHEMISTRY 2020; 46:199-212. [PMID: 31637540 DOI: 10.1007/s10695-019-00708-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 09/09/2019] [Indexed: 06/10/2023]
Abstract
The Indian major carp, mrigal (Cirrhinus mrigala), is a bottom-dwelling fish that can survive hypoxic episodes in its natural environment. We hypothesise that it can better survive hypoxic conditions by altering metabolic responses through GABA (Gamma-aminobutyric acid) supplementation. In the first experiment, the hypoxia tolerance time of the fishes was evaluated under extreme anoxic conditions after feeding with GABA, which showed that GABA had improved survival time under hypoxia. To study the response of dietary GABA in hypoxia-exposed fish, the branchial HIF-1α expression levels, serum thyroid hormone levels and hepatic metabolic responses were assessed in the subsequent experiment. The treatment groups were fed for 60 days with experimental diets containing 4 levels of GABA (0.00% G, 0.50% G, 0.75% G and 1.0%G) and were subjected to 72-h hypoxia exposure (0.5 ± 0.02 mg L-1 dissolved oxygen (DO)) whereas a control group was maintained under normoxic conditions (6.0 ± 0.21 mg L-1 DO). The five treatment groups with three replicates were C0 (0% G + normoxia), H0 (0% G + hypoxia), H0.5 (0.50% G + hypoxia), H0.75 (0.75% G + hypoxia) and H1.0 (1.00% G + hypoxia). The results indicated that GABA supplementation triggered downregulation of HIF 1 alpha expression. When compared with the control group, decreased thyroxine (T4) and triiodothyronine (T3) levels were observed in the GABA-fed hypoxic groups. However, TSH (thyroid stimulating hormone) level remained unchanged in all the treatments. The LDH (lactate dehydrogenase) level in hypoxia-exposed groups was decreased by GABA supplementation. Our study demonstrated that GABA supplementation restores acute hypoxia-induced HIF-1α expression, thyroid hormone levels and LDH activities. On the other hand, it enhanced the citrate synthase (CS) activities at 0.5-1.00%, which showed a sharp decline in hypoxia. Hypoxia caused increase in the serum metabolites such as glucose, lactate, cholesterol and triglycerides. However, GABA supplementation was partially effective in reducing glucose and lactate level while triglycerides and cholesterol values remained unchanged. Overall, our results suggested a potential role of GABA in suppressing metabolism during hypoxia exposure, which can increase the chances of survival of the species Cirrhinus mrigala during hypoxia.
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Affiliation(s)
- Tincy Varghese
- Fish Physiology and Biochemistry Division, ICAR-Central Institute of Fisheries Education, Off-Yari Road, Versova, Andheri (W), Mumbai, 400061, India.
| | - V J Rejish Kumar
- Department of Aquaculture, Kerala University of Fisheries and Ocean Studies, Kochi, 682 506, India
| | - Garima Anand
- Fish Physiology and Biochemistry Division, ICAR-Central Institute of Fisheries Education, Off-Yari Road, Versova, Andheri (W), Mumbai, 400061, India
| | - Subrata Dasgupta
- Fish Physiology and Biochemistry Division, ICAR-Central Institute of Fisheries Education, Off-Yari Road, Versova, Andheri (W), Mumbai, 400061, India
| | - Asim Kumar Pal
- Fish Physiology and Biochemistry Division, ICAR-Central Institute of Fisheries Education, Off-Yari Road, Versova, Andheri (W), Mumbai, 400061, India
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18
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Rood K, Lopez V, La Frano MR, Fiehn O, Zhang L, Blood AB, Wilson SM. Gestational Hypoxia and Programing of Lung Metabolism. Front Physiol 2019; 10:1453. [PMID: 31849704 PMCID: PMC6895135 DOI: 10.3389/fphys.2019.01453] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 11/11/2019] [Indexed: 12/12/2022] Open
Abstract
Gestational hypoxia is a risk factor in the development of pulmonary hypertension in the newborn and other sequela, however, the mechanisms associated with the disease remain poorly understood. This review highlights disruption of metabolism by antenatal high altitude hypoxia and the impact this has on pulmonary hypertension in the newborn with discussion of model organisms and human populations. There is particular emphasis on modifications in glucose and lipid metabolism along with alterations in mitochondrial function. Additional focus is placed on increases in oxidative stress and the progression of pulmonary vascular disease in the newborn and on the need for further exploration using a combination of contemporary and classical approaches.
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Affiliation(s)
- Kristiana Rood
- Lawrence D. Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Vanessa Lopez
- Lawrence D. Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Michael R La Frano
- Department of Food Science and Nutrition, Center for Health Research, California Polytechnic State University, San Luis Obispo, CA, United States.,Center for Health Research, California Polytechnic State University, San Luis Obispo, CA, United States
| | - Oliver Fiehn
- NIH West Coast Metabolomics Center, University of California, Davis, Davis, CA, United States.,Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, United States
| | - Lubo Zhang
- Lawrence D. Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Arlin B Blood
- Lawrence D. Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Sean M Wilson
- Lawrence D. Longo MD Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
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Bhandari S, Cavalleri GL. Population History and Altitude-Related Adaptation in the Sherpa. Front Physiol 2019; 10:1116. [PMID: 31555147 PMCID: PMC6722185 DOI: 10.3389/fphys.2019.01116] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 08/12/2019] [Indexed: 12/29/2022] Open
Abstract
The first ascent of Mount Everest by Tenzing Norgay and Sir Edmund Hillary in 1953 brought global attention to the Sherpa people and human performance at altitude. The Sherpa inhabit the Khumbu Valley of Nepal, and are descendants of a population that has resided continuously on the Tibetan plateau for the past ∼25,000 to 40,000 years. The long exposure of the Sherpa to an inhospitable environment has driven genetic selection and produced distinct adaptive phenotypes. This review summarizes the population history of the Sherpa and their physiological and genetic adaptation to hypoxia. Genomic studies have identified robust signals of positive selection across EPAS1, EGLN1, and PPARA, that are associated with hemoglobin levels, which likely protect the Sherpa from altitude sickness. However, the biological underpinnings of other adaptive phenotypes such as birth weight and the increased reproductive success of Sherpa women are unknown. Further studies are required to identify additional signatures of selection and refine existing Sherpa-specific adaptive phenotypes to understand how genetic factors have underpinned adaptation in this population. By correlating known and emerging signals of genetic selection with adaptive phenotypes, we can further reveal hypoxia-related biological mechanisms of adaptation. Ultimately this work could provide valuable information regarding treatments of hypoxia-related illnesses including stroke, heart failure, lung disease and cancer.
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Affiliation(s)
- Sushil Bhandari
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Gianpiero L Cavalleri
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
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Impaired redox homeostasis in the heart left ventricles of aged rats experiencing fast-developing severe hypobaric hypoxia. Biogerontology 2019; 20:711-722. [DOI: 10.1007/s10522-019-09826-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 07/25/2019] [Indexed: 01/17/2023]
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Rahar B, Chawla S, Tulswani R, Saxena S. Acute Hypobaric Hypoxia-Mediated Biochemical/Metabolic Shuffling and Differential Modulation of S1PR-SphK in Cardiac and Skeletal Muscles. High Alt Med Biol 2019; 20:78-88. [PMID: 30892968 DOI: 10.1089/ham.2018.0046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
AIM High altitude exposure alters biochemical, metabolic, and physiological features of heart and skeletal muscles, and hence has pathological consequences in these tissues. Central to these hypoxia-associated biochemical/metabolic shuffling are energy deficit accumulation of free radicals and ensuing oxidative damage in the tissue. Recent preclinical/clinical studies indicate sphingosine-1-phosphate (S1P) axis, comprising S1P G protein coupled receptors (S1PR1-5) and its synthesizing enzyme-sphingosine kinase (SphK) to have key regulatory roles in homeostatic cardiac and skeletal muscle biology. In view of this, the aim of the present study was to chart the initiation and progression of biochemical/metabolic shuffling and assess the coincident differential modulation of S1PR(1-5) expression and total SphK activity in cardiac and skeletal muscles from rats exposed to progressive hypobaric hypoxia (HH; 21,000 feet for 12, 24, and 48 hours). RESULTS HH-associated responses were evident as raised damage markers in plasma, oxidative stress, decreased total tissue protein, imbalance of intermediate metabolites, and aerobic/anaerobic enzyme activities in cardiac and skeletal muscles (gastrocnemius and soleus) culminating as energy deficit. CONCLUSION Cardiac and gastrocnemius muscles were more susceptible to hypoxic environment than soleus muscle. These differential responses were directly and indirectly coincident with temporal expression of S1PR(1-5) and SphK activity.
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Affiliation(s)
- Babita Rahar
- 1 Experimental Biology Division, Defense Institute of Physiology and Allied Sciences, Defense Research and Development Organization, Delhi, India
| | - Sonam Chawla
- 1 Experimental Biology Division, Defense Institute of Physiology and Allied Sciences, Defense Research and Development Organization, Delhi, India
| | - Rajkumar Tulswani
- 2 PACT Division, Defense Institute of Physiology and Allied Sciences, Defense Research and Development Organization, Delhi, India
| | - Shweta Saxena
- 3 Medicinal and Aromatic Plant Division, Defense Institute of High Altitude Research (DIHAR), Defense Research and Development Organization, Jammu and Kashmir, India
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22
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Uncovering mechanisms of global ocean change effects on the Dungeness crab (Cancer magister) through metabolomics analysis. Sci Rep 2019; 9:10717. [PMID: 31341175 PMCID: PMC6656712 DOI: 10.1038/s41598-019-46947-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 07/04/2019] [Indexed: 01/22/2023] Open
Abstract
The Dungeness crab is an economically and ecologically important species distributed along the North American Pacific coast. To predict how Dungeness crab may physiologically respond to future global ocean change on a molecular level, we performed untargeted metabolomic approaches on individual Dungeness crab juveniles reared in treatments that mimicked current and projected future pH and dissolved oxygen conditions. We found 94 metabolites and 127 lipids responded in a condition-specific manner, with a greater number of known compounds more strongly responding to low oxygen than low pH exposure. Pathway analysis of these compounds revealed that juveniles may respond to low oxygen through evolutionarily conserved processes including downregulating glutathione biosynthesis and upregulating glycogen storage, and may respond to low pH by increasing ATP production. Most interestingly, we found that the response of juveniles to combined low pH and low oxygen exposure was most similar to the low oxygen exposure response, indicating low oxygen may drive the physiology of juvenile crabs more than pH. Our study elucidates metabolic dynamics that expand our overall understanding of how the species might respond to future ocean conditions and provides a comprehensive dataset that could be used in future ocean acidification response studies.
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Martos-Sitcha JA, Simó-Mirabet P, de Las Heras V, Calduch-Giner JÀ, Pérez-Sánchez J. Tissue-Specific Orchestration of Gilthead Sea Bream Resilience to Hypoxia and High Stocking Density. Front Physiol 2019; 10:840. [PMID: 31354511 PMCID: PMC6635561 DOI: 10.3389/fphys.2019.00840] [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: 01/01/2019] [Accepted: 06/19/2019] [Indexed: 12/20/2022] Open
Abstract
Two different O2 levels (normoxia: 75–85% O2 saturation; moderate hypoxia: 42–43% O2 saturation) and stocking densities (LD: 9.5, and HD: 19 kg/m3) were assessed on gilthead sea bream (Sparus aurata) in a 3-week feeding trial. Reduced O2 availability had a negative impact on feed intake and growth rates, which was exacerbated by HD despite of the improvement in feed efficiency. Blood physiological hallmarks disclosed the enhancement in O2-carrying capacity in fish maintained under moderate hypoxia. This feature was related to a hypo-metabolic state to cope with a chronic and widespread environmental O2 reduction, which was accompanied by a differential regulation of circulating cortisol and growth hormone levels. Customized PCR-arrays were used for the simultaneous gene expression profiling of 34–44 selected stress and metabolic markers in liver, white skeletal muscle, heart, and blood cells. The number of differentially expressed genes ranged between 22 and 19 in liver, heart, and white skeletal muscle to 5 in total blood cells. Partial Least-Squares Discriminant Analysis (PLS-DA) explained [R2Y(cum)] and predicted [Q2Y(cum)] up to 95 and 65% of total variance, respectively. The first component (R2Y = 0.2889) gathered fish on the basis of O2 availability, and liver and cardiac genes on the category of energy sensing and oxidative metabolism (cs, hif-1α, pgc1α, pgc1β, sirts 1-2-4-5-6-7), antioxidant defense and tissue repair (prdx5, sod2, mortalin, gpx4, gr, grp-170, and prdx3) and oxidative phosphorylation (nd2, nd5, and coxi) highly contributed to this separation. The second component (R2Y = 0.2927) differentiated normoxic fish at different stocking densities, and the white muscle clearly promoted this separation by a high over-representation of genes related to GH/IGF system (ghr-i, igfbp6b, igfbp5b, insr, igfbp3, and igf-i). The third component (R2Y = 0.2542) discriminated the effect of stocking density in fish exposed to moderate hypoxia by means of hepatic fatty acid desaturases (fads2, scd1a, and scd1b) and muscle markers of fatty acid oxidation (cpt1a). All these findings disclose the different contribution of analyzed tissues (liver ≥ heart > muscle > blood) and specific genes to the hypoxic- and crowding stress-mediated responses. This study will contribute to better explain and understand the different stress resilience of farmed fish across individuals and species.
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Affiliation(s)
- Juan Antonio Martos-Sitcha
- Nutrigenomics and Fish Growth Endocrinology, Institute of Aquaculture Torre de la Sal (IATS-CSIC), Castellón, Spain
| | - Paula Simó-Mirabet
- Nutrigenomics and Fish Growth Endocrinology, Institute of Aquaculture Torre de la Sal (IATS-CSIC), Castellón, Spain
| | - Verónica de Las Heras
- Nutrigenomics and Fish Growth Endocrinology, Institute of Aquaculture Torre de la Sal (IATS-CSIC), Castellón, Spain
| | - Josep Àlvar Calduch-Giner
- Nutrigenomics and Fish Growth Endocrinology, Institute of Aquaculture Torre de la Sal (IATS-CSIC), Castellón, Spain
| | - Jaume Pérez-Sánchez
- Nutrigenomics and Fish Growth Endocrinology, Institute of Aquaculture Torre de la Sal (IATS-CSIC), Castellón, Spain
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Dünnwald T, Gatterer H, Faulhaber M, Arvandi M, Schobersberger W. Body Composition and Body Weight Changes at Different Altitude Levels: A Systematic Review and Meta-Analysis. Front Physiol 2019; 10:430. [PMID: 31057421 PMCID: PMC6477059 DOI: 10.3389/fphys.2019.00430] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 03/28/2019] [Indexed: 12/12/2022] Open
Abstract
Changes in body composition and weight loss frequently occur when humans are exposed to hypoxic environments. The mechanisms thought to be responsible for these changes are increased energy expenditure resulting from increased basal metabolic rate and/or high levels of physical activity, inadequate energy intake, fluid loss as well as gastrointestinal malabsorption. The severity of hypoxia, the duration of exposure as well as the level of physical activity also seem to play crucial roles in the final outcome. On one hand, excessive weight loss in mountaineers exercising at high altitudes may affect performance and climbing success. On the other, hypoxic conditioning is presumed to have an important therapeutic potential in weight management programs in overweight/obese people, especially in combination with exercise. In this regard, it is important to define the hypoxia effect on both body composition and weight change. The purpose of this study is to define, through the use of meta-analysis, the extent of bodyweight -and body composition changes within the three internationally classified altitude levels (moderate altitude: 1500–3500 m; high altitude: 3500–5300 m; extreme altitude: >5300 m), with emphasis on physical activity, nutrition, duration of stay and type of exposure.
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Affiliation(s)
- Tobias Dünnwald
- Institute for Sports Medicine, Alpine Medicine & Health Tourism, UMIT - University for Health Sciences, Medical Informatics and Technology, Hall in Tirol, Austria
| | - Hannes Gatterer
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Martin Faulhaber
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Marjan Arvandi
- Institute of Public Health, Medical Decision Making and HTA, Department for Public Health, Medical Decision Making and Health Technology Assessment, UMIT - University for Health Sciences, Medical Informatics and Technology, Hall in Tirol, Austria
| | - Wolfgang Schobersberger
- Institute for Sports Medicine, Alpine Medicine & Health Tourism, UMIT - University for Health Sciences, Medical Informatics and Technology, Hall in Tirol, Austria.,Tirol Kliniken GmbH Innsbruck, Innsbruck, Austria
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Chen TH, Ma GC, Lin WH, Lee DJ, Wu SH, Liao BY, Chen M, Lin LK. Genome-Wide Microarray Analysis Suggests Transcriptomic Response May Not Play a Major Role in High- to Low-Altitude Acclimation in Harvest Mouse ( Micromys minutus). Animals (Basel) 2019; 9:ani9030092. [PMID: 30871279 PMCID: PMC6466072 DOI: 10.3390/ani9030092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 03/09/2019] [Accepted: 03/10/2019] [Indexed: 11/29/2022] Open
Abstract
Simple Summary Micromys minutus is a small rodent species that has a wide range of vertical distribution in Taiwan. By comparing the gene expression profile of the skeletal muscle tissues taken from individuals native to the high-altitude environment and those transferred to the low-altitude captive site, the Tnfrsf12a gene was demonstrated to have a differential expression pattern. Although this finding may be correlated with the altitude acclimation, the observation of only one gene transcript with significant alteration leads us to suggest that genetic response may not play a major role in altitude acclimation in M. minutus. Future comparative functional genomics studies involving other organ systems (in addition to skeletal muscles) and alarger sample size are warranted for better insight into the altitude acclimation of this small rodent species. Abstract The harvest mouse (Micromys minutus) is a small rodent species with a wide range of vertical distribution in Taiwan, extending from the sea level to 3100 m altitude. This species has recently suffered from habitat loss in high-altitude areas due to orchard cultivation, which may have resulted in mouse migration from high to low altitude. To investigate whether there is any physiological mechanism involved in altitude acclimation, rat cDNA microarray was used to compare transcriptomic patterns of the skeletal muscle tissues taken from individuals native to the high-altitude environment and those transferred to the low-altitude captive site. Of the 23,188 genes being analyzed, 47 (33 up-regulated and 14 down-regulated) were found to have differential expression (fold change > 4 or < −4, ANOVA p < 0.05). However, after multiple testing correction with a false discovery rate (FDR), only the result for Tnfrsf12a was found to be statistically significant (fold change = 13, FDR p < 0.05). The result was confirmed by quantitative polymerase chain reaction (q-PCR). The expression of Tnfrsf12a possibly relates to the skeletal muscle biology and thus can be correlated with altitude acclimation. However, finding only one gene transcript with significant alteration suggests that transcriptomic response may not play a major role in high- to low-altitude acclimation in harvest mouse.
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Affiliation(s)
- Tze-Ho Chen
- Department of Life Science, Tunghai University, Taichung 40704, Taiwan.
- Department of Obstetrics and Gynecology, Changhua Christian Hospital, Changhua 50006, Taiwan.
| | - Gwo-Chin Ma
- Department of Genomic Medicine and Center for Medical Genetics, Changhua Christian Hospital, Changhua 50046, Taiwan.
- Department of Genomic Science and Technology, Changhua Christian Hospital Healthcare System,Changhua Christian Hospital, Changhua 50046, Taiwan.
- Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung 40601, Taiwan.
| | - Wen-Hsiang Lin
- Department of Genomic Medicine and Center for Medical Genetics, Changhua Christian Hospital, Changhua 50046, Taiwan.
- Department of Genomic Science and Technology, Changhua Christian Hospital Healthcare System,Changhua Christian Hospital, Changhua 50046, Taiwan.
| | - Dong-Jay Lee
- Department of Genomic Medicine and Center for Medical Genetics, Changhua Christian Hospital, Changhua 50046, Taiwan.
- Department of Genomic Science and Technology, Changhua Christian Hospital Healthcare System,Changhua Christian Hospital, Changhua 50046, Taiwan.
| | - Sheng-Hai Wu
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan.
| | - Ben-Yang Liao
- Division of Biostatistics & Bioinformatics, Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan.
| | - Ming Chen
- Department of Life Science, Tunghai University, Taichung 40704, Taiwan.
- Department of Genomic Medicine and Center for Medical Genetics, Changhua Christian Hospital, Changhua 50046, Taiwan.
- Department of Genomic Science and Technology, Changhua Christian Hospital Healthcare System,Changhua Christian Hospital, Changhua 50046, Taiwan.
- Department of Obstetrics and Gynecology, College of Medicine, National Taiwan University, Taipei 10041, Taiwan.
- Department of Medical Genetics, National Taiwan University Hospital, Taipei 10041, Taiwan.
- Department of Molecular Biotechnology, Da-Yeh University, Changhua 51591, Taiwan.
| | - Liang-Kong Lin
- Department of Life Science, Tunghai University, Taichung 40704, Taiwan.
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26
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O'Brien KA, Atkinson RA, Richardson L, Koulman A, Murray AJ, Harridge SDR, Martin DS, Levett DZH, Mitchell K, Mythen MG, Montgomery HE, Grocott MPW, Griffin JL, Edwards LM. Metabolomic and lipidomic plasma profile changes in human participants ascending to Everest Base Camp. Sci Rep 2019; 9:2297. [PMID: 30783167 PMCID: PMC6381113 DOI: 10.1038/s41598-019-38832-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 01/10/2019] [Indexed: 12/19/2022] Open
Abstract
At high altitude oxygen delivery to the tissues is impaired leading to oxygen insufficiency (hypoxia). Acclimatisation requires adjustment to tissue metabolism, the details of which remain incompletely understood. Here, metabolic responses to progressive environmental hypoxia were assessed through metabolomic and lipidomic profiling of human plasma taken from 198 human participants before and during an ascent to Everest Base Camp (5,300 m). Aqueous and lipid fractions of plasma were separated and analysed using proton (1H)-nuclear magnetic resonance spectroscopy and direct infusion mass spectrometry, respectively. Bayesian robust hierarchical regression revealed decreasing isoleucine with ascent alongside increasing lactate and decreasing glucose, which may point towards increased glycolytic rate. Changes in the lipid profile with ascent included a decrease in triglycerides (48-50 carbons) associated with de novo lipogenesis, alongside increases in circulating levels of the most abundant free fatty acids (palmitic, linoleic and oleic acids). Together, this may be indicative of fat store mobilisation. This study provides the first broad metabolomic account of progressive exposure to environmental hypobaric hypoxia in healthy humans. Decreased isoleucine is of particular interest as a potential contributor to muscle catabolism observed with exposure to hypoxia at altitude. Substantial changes in lipid metabolism may represent important metabolic responses to sub-acute exposure to environmental hypoxia.
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Affiliation(s)
- Katie A O'Brien
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK.
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, UK.
| | - R Andrew Atkinson
- Centre for Biomolecular Spectroscopy and Randall Division of Cell and Molecular Biophysics King's College London Guy's Campus London, London, UK
| | - Larissa Richardson
- NIHR BRC Nutritional Biomarker Laboratory, University of Cambridge, Pathology building level 4, Addenbrooke's Hospital, Cambridge, UK
| | - Albert Koulman
- NIHR BRC Nutritional Biomarker Laboratory, University of Cambridge, Pathology building level 4, Addenbrooke's Hospital, Cambridge, UK
| | - Andrew J Murray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, UK
| | - Stephen D R Harridge
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK
| | - Daniel S Martin
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, First Floor, 170 Tottenham Court Road, London, W1T 7HA, UK
- Critical Care Unit, Royal Free Hospital, Pond Street, London, NW3 2QG, UK
| | - Denny Z H Levett
- Southampton NIHR Biomedical Research Centre, University Hospital Southampton, Southampton, UK
- Integrative Physiological and Critical Illness Group, Division of Clinical and Experimental Science, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Kay Mitchell
- Southampton NIHR Biomedical Research Centre, University Hospital Southampton, Southampton, UK
- Integrative Physiological and Critical Illness Group, Division of Clinical and Experimental Science, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Monty G Mythen
- University College London Hospitals National Institute of Health Research Biomedical Research Centre, London, UK
| | - Hugh E Montgomery
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, First Floor, 170 Tottenham Court Road, London, W1T 7HA, UK
- Centre for Human Health and Performance, Department of Medicine, University College London, London, UK
| | - Michael P W Grocott
- Southampton NIHR Biomedical Research Centre, University Hospital Southampton, Southampton, UK
- Integrative Physiological and Critical Illness Group, Division of Clinical and Experimental Science, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Julian L Griffin
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, Tennis Court Road, Cambridge, UK
| | - Lindsay M Edwards
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK.
- Respiratory Data Sciences Group, Respiratory TAU, GlaxoSmithKline Medicines Research, Stevenage, UK.
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Carriker CR, Rombach P, Stevens BM, Vaughan RA, Gibson AL. Acute dietary nitrate supplementation does not attenuate oxidative stress or the hemodynamic response during submaximal exercise in hypobaric hypoxia. Appl Physiol Nutr Metab 2018; 43:1268-1274. [DOI: 10.1139/apnm-2017-0813] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The purpose of this study was to investigate changes in oxidative stress, arterial oxygen saturation (SaO2), blood pressure (BP), and heart rate (HR) during exercise in hypobaric hypoxia following acute dietary nitrate supplementation. Nine well-trained (maximal oxygen consumption, 60.8 ± 7.8 mL·kg−1·min−1) males (age, 29 ± 7 years) visited the laboratory on 3 occasions, each separated by 1 week. Visit 1 included a maximal aerobic cycling test and five 5-min increasing-intensity exercise bouts in a normobaric environment (1600 m). A single dose of either a nitrate-depleted placebo (PL) or a nitrate-rich beverage (NR; 12.8 mmol nitrate) was consumed 2.5 h prior to exercise during visits 2 and 3 (3500 m) in a double-blind, placebo-controlled, crossover study consisting of a 5-min cycling warm-up and 4 bouts, each 5 min in duration, separated by 4-min periods of passive rest. Exercise wattages were determined during visit 1 and corresponded to 25%, 40%, 50%, 60%, and 70% of normobaric maximal oxygen consumption. Catalase and 8-isoprostane were measured before and after exercise (immediately before and 1 h postexercise, respectively). NR increased plasma nitrite (1.53 ± 0.83 μmol·L−1) compared with PL (0.88 ± 0.56 μmol·L−1) (p < 0.05). In both conditions, postexercise (3500 m) 8-isoprostane (PL, 23.49 ± 3.38 to 60.90 ± 14.95 pg·mL−1; NR, 23.23 ± 4.12 to 52.11 ± 19.76 pg·mL−1) and catalase (PL, 63.89 ± 25.69 to 128.15 ± 41.80 mmol·min−1·mL−1; NR, 78.89 ± 30.95 to 109.96 ± 35.05 mmol·min−1·mL−1) were elevated compared with baseline resting values (p < 0.05). However, both 8-isoprostane and catalase were similar in the 2 groups (PL and NR) (p = 0.217 and p = 0.080, respectively). We concluded that an acute, pre-exercise dose of dietary nitrate yielded no beneficial changes in oxidative stress, SaO2, BP, or HR in healthy, aerobically fit men exercising at 3500 m.
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Affiliation(s)
- Colin R. Carriker
- Department of Exercise Science, High Point University, High Point, NC 27268, USA
- Department of Health, Exercise and Sports Sciences, University of New Mexico, Albuquerque, NM 87131, USA
| | - Paige Rombach
- Department of Exercise Science, High Point University, High Point, NC 27268, USA
| | - Brooke M. Stevens
- Department of Exercise Science, High Point University, High Point, NC 27268, USA
| | - Roger A. Vaughan
- Department of Exercise Science, High Point University, High Point, NC 27268, USA
| | - Ann L. Gibson
- Department of Health, Exercise and Sports Sciences, University of New Mexico, Albuquerque, NM 87131, USA
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Davison G, Vinaixa M, McGovern R, Beltran A, Novials A, Correig X, McClean C. Metabolomic Response to Acute Hypoxic Exercise and Recovery in Adult Males. Front Physiol 2018; 9:1682. [PMID: 30534085 PMCID: PMC6275205 DOI: 10.3389/fphys.2018.01682] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 11/08/2018] [Indexed: 12/28/2022] Open
Abstract
Metabolomics is a relatively new “omics” approach used to characterize metabolites in a biological system at baseline and following a diversity of stimuli. However, the metabolomic response to exercise in hypoxia currently remains unknown. To examine this, 24 male participants completed 1 h of exercise at a workload corresponding to 75% of pre-determined O2max in hypoxia (Fio2 = 0.16%), and repeated in normoxia (Fio2 = 0.21%), while pre- and post-exercise and 3 h post-exercise metabolites were analyzed using a LC ESI-qTOF-MS untargeted metabolomics approach in serum samples. Exercise in hypoxia and in normoxia independently increased metabolism as shown by a change in a combination of twenty-two metabolites associated with lipid metabolism (p < 0.05, pre vs. post-exercise), though hypoxia per se did not induce a greater metabolic change when compared with normoxia (p > 0.05). Recovery from exercise in hypoxia independently decreased seventeen metabolites associated with lipid metabolism (p < 0.05, post vs. 3 h post-exercise), compared with twenty-two metabolites in normoxia (p < 0.05, post vs. 3 h post-exercise). Twenty-six metabolites were identified as responders to exercise and recovery (pooled hypoxia and normoxia pre vs. recovery, p < 0.05), including metabolites associated with purine metabolism (adenine, adenosine and hypoxanthine), the amino acid phenylalanine, and several acylcarnitine molecules. Our novel data provides preliminary evidence of subtle metabolic differences to exercise and recovery in hypoxia and normoxia. Specifically, exercise in hypoxia activates metabolic pathways aligned to purine and lipid metabolism, but this effect is not selectively different from exercise in normoxia. We also show that exercise per se can activate pathways associated with lipid, protein and purine nucleotide metabolism.
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Affiliation(s)
- Gareth Davison
- Sport and Exercise Science Research Institute, Ulster University, Antrim, United Kingdom
| | - Maria Vinaixa
- Metabolomics Platform of the Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders, IISPV - Rovira i Virgili University, Tarragona, Spain
| | - Rose McGovern
- Sport and Exercise Science Research Institute, Ulster University, Antrim, United Kingdom
| | - Antoni Beltran
- Metabolomics Platform of the Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders, IISPV - Rovira i Virgili University, Tarragona, Spain
| | - Anna Novials
- Department of Endocrinology, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain
| | - Xavier Correig
- Metabolomics Platform of the Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders, IISPV - Rovira i Virgili University, Tarragona, Spain
| | - Conor McClean
- Sport and Exercise Science Research Institute, Ulster University, Antrim, United Kingdom
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29
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Li Y, Liu Z, Zhang Y, Zhao Q, Wang X, Lu P, Zhang H, Wang Z, Dong H, Zhang Z. PEDF protects cardiomyocytes by promoting FUNDC1‑mediated mitophagy via PEDF-R under hypoxic condition. Int J Mol Med 2018; 41:3394-3404. [PMID: 29512692 PMCID: PMC5881750 DOI: 10.3892/ijmm.2018.3536] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 02/15/2018] [Indexed: 01/15/2023] Open
Abstract
Pigment epithelial-derived factor (PEDF) is known to exert diverse physiological activities. Previous studies suggest that hypoxia could induce mitophagy. Astoundingly, under hypoxic condition, we found that PEDF decreased the mitochondrial density of cardiomyocytes. In this study, we evaluated whether PEDF could decrease the mitochondrial density and play a protective role in hypoxic cardiomyocytes via promoting mitophagy. Immunostaining and western blotting were used to analyze mitochondrial density and mitophagy of hypoxic cardiomyocytes. Gas chromatography-mass spectrometry and ELISA were used to analyze levels of palmitic acid and diacylglycerol. Transmission Electron Microscopy was used to detect mitophagy and the mitochondrial density in adult male Sprague-Dawley rat model of acute myocardial infarction. Compared to the control group, we observed that PEDF decreased mitochondrial density through promoting hypoxic cardiomyocyte mitophagy. PEDF increased the levels of palmitic acid and diacylglycerol, and then upregulated the levels of protein kinase Cα (PKC-α) and its activation. Furthermore, inhibition of PKC-α by Go6976 could effectively suppress PEDF-induced mitophagy. Besides, we found that PEDF promoted FUNDC1-mediated cardiomyocyte mitophagy via ULK1, which depended on the activation of PKC-α. Finally, we discovered that mitophagy was increased and mitochondrial density was reduced in adult male Sprague-Dawley rat model of acute myocardial infarction. We concluded that PEDF promotes mitophagy to protect hypoxic cardiomyocytes, through PEDF/PEDF-R/PA/DAG/PKC-α/ULK1/FUNDC1 pathway.
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Affiliation(s)
- Yufeng Li
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Zhiwei Liu
- Research Facility Center for Morphology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Yiqian Zhang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Qixiang Zhao
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Xiaoyu Wang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Peng Lu
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Hao Zhang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Zhu Wang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
| | - Hongyan Dong
- Research Facility Center for Morphology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Zhongming Zhang
- Department of Thoracic Cardiovascular Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221006, P.R. China
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Rahar B, Chawla S, Pandey S, Bhatt AN, Saxena S. Sphingosine-1-phosphate pretreatment amends hypoxia-induced metabolic dysfunction and impairment of myogenic potential in differentiating C2C12 myoblasts by stimulating viability, calcium homeostasis and energy generation. J Physiol Sci 2018; 68:137-151. [PMID: 28070865 PMCID: PMC10717551 DOI: 10.1007/s12576-016-0518-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 12/26/2016] [Indexed: 12/19/2022]
Abstract
Sphingosine-1-phosphate (S1P) has a role in transpiration in patho-physiological signaling in skeletal muscles. The present study evaluated the pre-conditioning efficacy of S1P in facilitating differentiation of C2C12 myoblasts under a normoxic/hypoxic cell culture environment. Under normoxia, exogenous S1P significantly promoted C2C12 differentiation as evident from morphometric descriptors and differentiation markers of the mature myotubes, but it could facilitate only partial recovery from hypoxia-induced compromised differentiation. Pretreatment of S1P optimized the myokine secretion, intracellular calcium release and energy generation by boosting the aerobic/anaerobic metabolism and mitochondrial mass. In the hypoxia-exposed cells, there was derangement of the S1PR1-3 expression patterns, while the same could be largely restored with S1P pretreatment. This is being proposed as a plausible underlying mechanism for the observed pro-myogenic efficacy of exogenous S1P preconditioning. The present findings are an invaluable addition to the existing knowledge on the pro-myogenic potential of S1P and may prove beneficial in the field of hypoxia-related myo-pathologies.
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Affiliation(s)
- Babita Rahar
- Experimental Biology Division, Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi, 110054, India
| | - Sonam Chawla
- Experimental Biology Division, Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi, 110054, India
| | - Sanjay Pandey
- Division of Metabolic and Cell Signaling Research, Institute of Nuclear Medicine and Allied Sciences (INMAS), Defence Research and Development Organization (DRDO), Brig. S.K. Mazumdar Road, Delhi, 110054, India
| | - Anant Narayan Bhatt
- Division of Metabolic and Cell Signaling Research, Institute of Nuclear Medicine and Allied Sciences (INMAS), Defence Research and Development Organization (DRDO), Brig. S.K. Mazumdar Road, Delhi, 110054, India
| | - Shweta Saxena
- Medicinal and Aromatic Plant Division, Defence Institute of High Altitude Research (DIHAR), Defence Research and Development Organization (DRDO), Ministry of Defence, Leh-Ladakh, 194101, Jammu and Kashmir, India.
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Avellanas Chavala ML. A journey between high altitude hypoxia and critical patient hypoxia: What can it teach us about compression and the management of critical disease? Med Intensiva 2017; 42:380-390. [PMID: 28919307 DOI: 10.1016/j.medin.2017.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 08/15/2017] [Indexed: 01/02/2023]
Abstract
High altitude sickness (hypobaric hypoxia) is a form of cellular hypoxia similar to that suffered by critically ill patients. The study of mountaineers exposed to extreme hypoxia offers the advantage of involving a relatively homogeneous and healthy population compared to those typically found in Intensive Care Units (ICUs), which are heterogeneous and generally less healthy. Knowledge of altitude physiology and pathology allows us to understanding how hypoxia affects critical patients. Comparable changes in mitochondrial biogenesis between both groups may reflect similar adaptive responses and suggest therapeutic interventions based on the protection or stimulation of such mitochondrial biogenesis. Predominance of the homozygous insertion (II) allele of the angiotensin-converting enzyme gene is present in both individuals who perform successful ascensions without oxygen above 8000 m and in critical patients who overcome certain disease conditions.
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Martos-Sitcha JA, Bermejo-Nogales A, Calduch-Giner JA, Pérez-Sánchez J. Gene expression profiling of whole blood cells supports a more efficient mitochondrial respiration in hypoxia-challenged gilthead sea bream ( Sparus aurata). Front Zool 2017; 14:34. [PMID: 28694839 PMCID: PMC5501551 DOI: 10.1186/s12983-017-0220-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 06/28/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Acclimation to abiotic challenges, including decreases in O2 availability, requires physiological and anatomical phenotyping to accommodate the organism to the environmental conditions. The retention of a nucleus and functional mitochondria in mature fish red blood cells makes blood a promising tissue to analyse the transcriptome and metabolic responses of hypoxia-challenged fish in an integrative and non-invasive manner. METHODS Juvenile gilthead sea bream (Sparus aurata) were reared at 20-21 °C under normoxic conditions (> 85% O2 saturation) followed by exposure to a gradual decrease in water O2 concentration to 3.0 ppm (41-42% O2 saturation) for 24 h or 1.3 ppm (18-19% O2 saturation) for up to 4 h. Blood samples were collected at three different sampling points for haematological, biochemical and transcriptomic analysis. RESULTS Blood physiological hallmarks remained almost unaltered at 3.0 ppm, but the haematocrit and circulating levels of haemoglobin, glucose and lactate were consistently increased when fish were maintained below the limiting oxygen saturation at 1.3 ppm. These findings were concurrent with an increase in total plasma antioxidant activity and plasma cortisol levels, whereas the opposite trend was observed for growth-promoting factors, such as insulin-like growth factor I. Additionally, gene expression profiling of whole blood cells revealed changes in upstream master regulators of mitochondria (pgcβ and nrf1), antioxidant enzymes (gpx1, gst3, and sod2), outer and inner membrane translocases (tom70, tom22, tim44, tim10, and tim9), components of the mitochondrial dynamics system (mfn2, miffb, miro1a, and miro2), apoptotic factors (aifm1), uncoupling proteins (ucp2) and oxidative enzymes of fatty acid β-oxidation (acca2, ech, and hadh), the tricarboxylic acid cycle (cs) and the oxidative phosphorylation pathway. The overall response is an extensive reduction in gene expression of almost all respiratory chain enzyme subunits of the five complexes, although mitochondrial-encoded catalytic subunits and nuclear-encoded regulatory subunits of Complex IV were primarily increased in hypoxic fish. CONCLUSIONS Our results demonstrate the re-adjustment of mitochondrial machinery at transcriptional level to cope with a decreased basal metabolic rate, consistent with a low risk of oxidative stress, diminished aerobic ATP production and higher O2-carrying capacity. Taken together, these results suggest that whole blood cells can be used as a highly informative target tissue of metabolic condition.
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Affiliation(s)
- Juan Antonio Martos-Sitcha
- Nutrigenomics and Fish Growth Endocrinology Group, Institute of Aquaculture Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Ribera de Cabanes, E-12595 Castellón, Spain
| | - Azucena Bermejo-Nogales
- Nutrigenomics and Fish Growth Endocrinology Group, Institute of Aquaculture Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Ribera de Cabanes, E-12595 Castellón, Spain
- Present address: Endocrine Disruption and Toxicity of Contaminants, Department of Environment, INIA, Madrid, Spain
| | - Josep Alvar Calduch-Giner
- Nutrigenomics and Fish Growth Endocrinology Group, Institute of Aquaculture Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Ribera de Cabanes, E-12595 Castellón, Spain
| | - Jaume Pérez-Sánchez
- Nutrigenomics and Fish Growth Endocrinology Group, Institute of Aquaculture Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Ribera de Cabanes, E-12595 Castellón, Spain
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Abstract
The Himalayan Sherpas, a human population of Tibetan descent, are highly adapted to life in the hypobaric hypoxia of high altitude. Mechanisms involving enhanced tissue oxygen delivery in comparison to Lowlander populations have been postulated to play a role in such adaptation. Whether differences in tissue oxygen utilization (i.e., metabolic adaptation) underpin this adaptation is not known, however. We sought to address this issue, applying parallel molecular, biochemical, physiological, and genetic approaches to the study of Sherpas and native Lowlanders, studied before and during exposure to hypobaric hypoxia on a gradual ascent to Mount Everest Base Camp (5,300 m). Compared with Lowlanders, Sherpas demonstrated a lower capacity for fatty acid oxidation in skeletal muscle biopsies, along with enhanced efficiency of oxygen utilization, improved muscle energetics, and protection against oxidative stress. This adaptation appeared to be related, in part, to a putatively advantageous allele for the peroxisome proliferator-activated receptor A (PPARA) gene, which was enriched in the Sherpas compared with the Lowlanders. Our findings suggest that metabolic adaptations underpin human evolution to life at high altitude, and could have an impact upon our understanding of human diseases in which hypoxia is a feature.
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Wandrag L, Siervo M, Riley HL, Khosravi M, Fernandez BO, Leckstrom CA, Martin DS, Mitchell K, Levett DZH, Montgomery HE, Mythen MG, Stroud MA, Grocott MPW, Feelisch M. Does hypoxia play a role in the development of sarcopenia in humans? Mechanistic insights from the Caudwell Xtreme Everest Expedition. Redox Biol 2017; 13:60-68. [PMID: 28570949 PMCID: PMC5451185 DOI: 10.1016/j.redox.2017.05.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 04/25/2017] [Accepted: 05/05/2017] [Indexed: 12/24/2022] Open
Abstract
Objectives Sarcopenia refers to the involuntary loss of skeletal muscle and is a predictor of physical disability/mortality. Its pathogenesis is poorly understood, although roles for altered hypoxic signaling, oxidative stress, adipokines and inflammatory mediators have been suggested. Sarcopenia also occurs upon exposure to the hypoxia of high altitude. Using data from the Caudwell Xtreme Everest expedition we therefore sought to analyze the extent of hypoxia-induced body composition changes and identify putative pathways associated with fat-free mass (FFM) and fat mass (FM) loss. Methods After baseline testing in London (75 m), 24 investigators ascended from Kathmandu (1300 m) to Everest base camp (EBC 5300 m) over 13 days. Fourteen investigators climbed above EBC, eight of whom reached the summit (8848 m). Assessments were conducted at baseline, during ascent and after one, six and eight week(s) of arrival at EBC. Changes in body composition (FM, FFM, total body water, intra- and extra-cellular water) were measured by bioelectrical impedance. Biomarkers of nitric oxide and oxidative stress were measured together with adipokines, inflammatory, metabolic and vascular markers. Results Participants lost a substantial, but variable, amount of body weight (7.3±4.9 kg by expedition end; p<0.001). A progressive loss of both FM and FFM was observed, and after eight weeks, the proportion of FFM loss was 48% greater than FM loss (p<0.008). Changes in protein carbonyls (p<0.001) were associated with a decline in FM whereas 4-hydroxynonenal (p<0.001) and IL-6 (p<0.001) correlated with FFM loss. GLP-1 (r=−0.45, p<0.001) and nitrite (r=−0.29, p<0.001) concentration changes were associated with FFM loss. In a multivariate model, GLP-1, insulin and nitrite were significant predictors of FFM loss while protein carbonyls were predicted FM loss. Conclusions The putative role of GLP-1 and nitrite as mediators of the effects of hypoxia on FFM is an intriguing finding. If confirmed, nutritional and pharmacological interventions targeting these pathways may offer new avenues for prevention and treatment of sarcopenia.
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Affiliation(s)
- Liesl Wandrag
- Nutrition and Dietetic Research Group, Department of Investigative Medicine, Imperial College London, UK; University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London W1T 7HA, UK
| | - Mario Siervo
- Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Campus for Ageing and Vitality, Newcastle on Tyne NE4 5PL, UK
| | - Heather L Riley
- Warwick Systems Biology Centre and Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Maryam Khosravi
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London W1T 7HA, UK; Department of Cell and Developmental Biology, Division of Biosciences, University College London, WC1B 6BT, UK
| | - Bernadette O Fernandez
- Warwick Systems Biology Centre and Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK; Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - Carl A Leckstrom
- Warwick Systems Biology Centre and Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Daniel S Martin
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London W1T 7HA, UK; Division of Surgery and Interventional Science, University College London, 9th Floor, Royal Free Hospital, London NW3 2QG, UK
| | - Kay Mitchell
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London W1T 7HA, UK; University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Denny Z H Levett
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London W1T 7HA, UK; University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton SO16 6YD, UK; Southampton NIHR Respiratory Biomedical Research Unit, UK
| | - Hugh E Montgomery
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London W1T 7HA, UK
| | - Monty G Mythen
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London W1T 7HA, UK
| | - Michael A Stroud
- University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Michael P W Grocott
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London W1T 7HA, UK; Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK; University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton SO16 6YD, UK; Southampton NIHR Respiratory Biomedical Research Unit, UK
| | - Martin Feelisch
- Warwick Systems Biology Centre and Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK; Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK; University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton SO16 6YD, UK; Southampton NIHR Respiratory Biomedical Research Unit, UK.
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Matu J, Deighton K, Ispoglou T, Duckworth L. The effect of moderate versus severe simulated altitude on appetite, gut hormones, energy intake and substrate oxidation in men. Appetite 2017; 113:284-292. [PMID: 28257941 DOI: 10.1016/j.appet.2017.02.041] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 02/21/2017] [Accepted: 02/27/2017] [Indexed: 11/17/2022]
Abstract
Acute exposure to high altitude (>3500 m) is associated with marked changes in appetite regulation and substrate oxidation but the effects of lower altitudes are unclear. This study examined appetite, gut hormone, energy intake and substrate oxidation responses to breakfast ingestion and exercise at simulated moderate and severe altitudes compared with sea-level. Twelve healthy males (mean ± SD; age 30 ± 9years, body mass index 24.4 ± 2.7 kg·m-2) completed in a randomised crossover order three, 305 min experimental trials at a simulated altitude of 0 m, 2150 m (∼15.8% O2) and 4300 m (∼11.7% O2) in a normobaric chamber. Participants entered the chamber at 8am following a 12 h fast. A standardised breakfast was consumed inside the chamber at 1 h. One hour after breakfast, participants performed a 60 min treadmill walk at 50% of relative V˙O2max. An ad-libitum buffet meal was consumed 1.5 h after exercise. Blood samples were collected prior to altitude exposure and at 60, 135, 195, 240 and 285 min. No trial based differences were observed in any appetite related measure before exercise. Post-exercise area under the curve values for acylated ghrelin, pancreatic polypeptide and composite appetite score were lower (all P < 0.05) at 4300 m compared with sea-level and 2150 m. There were no differences in glucagon-like peptide-1 between conditions (P = 0.895). Mean energy intake was lower at 4300 m (3728 ± 3179 kJ) compared with sea-level (7358 ± 1789 kJ; P = 0.007) and 2150 m (7390 ± 1226 kJ; P = 0.004). Proportional reliance on carbohydrate as a fuel was higher (P = 0.01) before breakfast but lower during (P = 0.02) and after exercise (P = 0.01) at 4300 m compared with sea-level. This study suggests that altitude-induced anorexia and a subsequent reduction in energy intake occurs after exercise during exposure to severe but not moderate simulated altitude. Acylated ghrelin concentrations may contribute to this effect.
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Affiliation(s)
- Jamie Matu
- Institute for Sport Physical Activity & Leisure, Leeds Beckett University, Leeds, United Kingdom.
| | - Kevin Deighton
- Institute for Sport Physical Activity & Leisure, Leeds Beckett University, Leeds, United Kingdom
| | - Theocharis Ispoglou
- Institute for Sport Physical Activity & Leisure, Leeds Beckett University, Leeds, United Kingdom
| | - Lauren Duckworth
- Institute for Sport Physical Activity & Leisure, Leeds Beckett University, Leeds, United Kingdom
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Gonzalez-Freire M, Semba RD, Ubaida-Mohien C, Fabbri E, Scalzo P, Højlund K, Dufresne C, Lyashkov A, Ferrucci L. The Human Skeletal Muscle Proteome Project: a reappraisal of the current literature. J Cachexia Sarcopenia Muscle 2017; 8:5-18. [PMID: 27897395 PMCID: PMC5326819 DOI: 10.1002/jcsm.12121] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/11/2016] [Accepted: 04/05/2016] [Indexed: 12/14/2022] Open
Abstract
Skeletal muscle is a large organ that accounts for up to half the total mass of the human body. A progressive decline in muscle mass and strength occurs with ageing and in some individuals configures the syndrome of 'sarcopenia', a condition that impairs mobility, challenges autonomy, and is a risk factor for mortality. The mechanisms leading to sarcopenia as well as myopathies are still little understood. The Human Skeletal Muscle Proteome Project was initiated with the aim to characterize muscle proteins and how they change with ageing and disease. We conducted an extensive review of the literature and analysed publically available protein databases. A systematic search of peer-reviewed studies was performed using PubMed. Search terms included 'human', 'skeletal muscle', 'proteome', 'proteomic(s)', and 'mass spectrometry', 'liquid chromatography-mass spectrometry (LC-MS/MS)'. A catalogue of 5431 non-redundant muscle proteins identified by mass spectrometry-based proteomics from 38 peer-reviewed scientific publications from 2002 to November 2015 was created. We also developed a nosology system for the classification of muscle proteins based on localization and function. Such inventory of proteins should serve as a useful background reference for future research on changes in muscle proteome assessed by quantitative mass spectrometry-based proteomic approaches that occur with ageing and diseases. This classification and compilation of the human skeletal muscle proteome can be used for the identification and quantification of proteins in skeletal muscle to discover new mechanisms for sarcopenia and specific muscle diseases that can be targeted for the prevention and treatment.
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Affiliation(s)
| | - Richard D Semba
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Elisa Fabbri
- National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Paul Scalzo
- National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Kurt Højlund
- Department of Endocrinology, Odense University Hospital, Odense, Denmark.,Institute of Clinical Research and Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | | | - Alexey Lyashkov
- National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Luigi Ferrucci
- National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
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Van Thienen R, Masschelein E, D'Hulst G, Thomis M, Hespel P. Twin Resemblance in Muscle HIF-1α Responses to Hypoxia and Exercise. Front Physiol 2017; 7:676. [PMID: 28149279 PMCID: PMC5241297 DOI: 10.3389/fphys.2016.00676] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 12/20/2016] [Indexed: 12/21/2022] Open
Abstract
Hypoxia-inducible factor-1 (HIF-1) is a master regulator of myocellular adaptation to exercise and hypoxia. However, the role of genetic factors in regulation of HIF-1 responses to exercise and hypoxia is unknown. We hypothesized that hypoxia at rest and during exercise stimulates the HIF-1 pathway and its downstream targets in energy metabolism regulation in a genotype-dependent manner. Eleven monozygotic twin (MZ) pairs performed an experimental trial in both normoxia and hypoxia (FiO2 10.7%). Biopsies were taken from m. vastus lateralis before and after a 20-min submaximal cycling bout @~30% of sea-level VO2max. Key-markers of the HIF-1 pathway and glycolytic and oxidative metabolism were analyzed using real-time PCR and Western Blot. Hypoxia increased HIF-1α protein expression by ~120% at rest vs. +150% during exercise (p < 0.05). Furthermore, hypoxia but not exercise increased muscle mRNA content of HIF-1α (+50%), PHD2 (+45%), pVHL (+45%; p < 0.05), PDK4 (+1200%), as well as PFK-M (+20%) and PPAR-γ1 (+60%; p < 0.05). Neither hypoxia nor exercise altered PHD1, LDH-A, PDH-A1, COX-4, and CS mRNA expressions. The hypoxic, but not normoxic exercise-induced increment of muscle HIF-1α mRNA content was about 10-fold more similar within MZ twins than between the twins (p < 0.05). Furthermore, in resting muscle the hypoxia-induced increments of muscle HIF-1α protein content, and HIF-1α and PDK4 mRNA content were about 3-4-fold more homogeneous within than between the twins pairs (p < 0.05). The present observations in monozygotic twins for the first time clearly indicate that the HIF-1α protein as well as mRNA responses to submaximal exercise in acute hypoxia are at least partly regulated by genetic factors.
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Affiliation(s)
- Ruud Van Thienen
- Exercise Physiology Research Group, Department of Kinesiology, KU Leuven Leuven, Belgium
| | - Evi Masschelein
- Exercise Physiology Research Group, Department of Kinesiology, KU Leuven Leuven, Belgium
| | - Gommaar D'Hulst
- Exercise Physiology Research Group, Department of Kinesiology, KU Leuven Leuven, Belgium
| | - Martine Thomis
- Physical Activity, Sports and Health Research Group, Department of Kinesiology, KU Leuven Leuven, Belgium
| | - Peter Hespel
- Exercise Physiology Research Group, Department of Kinesiology, KU Leuven Leuven, Belgium
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Lewis P, O'Halloran KD. Diaphragm Muscle Adaptation to Sustained Hypoxia: Lessons from Animal Models with Relevance to High Altitude and Chronic Respiratory Diseases. Front Physiol 2016; 7:623. [PMID: 28018247 PMCID: PMC5149537 DOI: 10.3389/fphys.2016.00623] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 11/28/2016] [Indexed: 12/13/2022] Open
Abstract
The diaphragm is the primary inspiratory pump muscle of breathing. Notwithstanding its critical role in pulmonary ventilation, the diaphragm like other striated muscles is malleable in response to physiological and pathophysiological stressors, with potential implications for the maintenance of respiratory homeostasis. This review considers hypoxic adaptation of the diaphragm muscle, with a focus on functional, structural, and metabolic remodeling relevant to conditions such as high altitude and chronic respiratory disease. On the basis of emerging data in animal models, we posit that hypoxia is a significant driver of respiratory muscle plasticity, with evidence suggestive of both compensatory and deleterious adaptations in conditions of sustained exposure to low oxygen. Cellular strategies driving diaphragm remodeling during exposure to sustained hypoxia appear to confer hypoxic tolerance at the expense of peak force-generating capacity, a key functional parameter that correlates with patient morbidity and mortality. Changes include, but are not limited to: redox-dependent activation of hypoxia-inducible factor (HIF) and MAP kinases; time-dependent carbonylation of key metabolic and functional proteins; decreased mitochondrial respiration; activation of atrophic signaling and increased proteolysis; and altered functional performance. Diaphragm muscle weakness may be a signature effect of sustained hypoxic exposure. We discuss the putative role of reactive oxygen species as mediators of both advantageous and disadvantageous adaptations of diaphragm muscle to sustained hypoxia, and the role of antioxidants in mitigating adverse effects of chronic hypoxic stress on respiratory muscle function.
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Affiliation(s)
- Philip Lewis
- Department of Physiology, School of Medicine, University College CorkCork, Ireland; Environmental Medicine and Preventative Research, Institute and Policlinic for Occupational Medicine, University of CologneCologne, Germany
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, University College Cork Cork, Ireland
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Galli GLJ, Crossley J, Elsey RM, Dzialowski EM, Shiels HA, Crossley DA. Developmental plasticity of mitochondrial function in American alligators, Alligator mississippiensis. Am J Physiol Regul Integr Comp Physiol 2016; 311:R1164-R1172. [PMID: 27707718 PMCID: PMC5256979 DOI: 10.1152/ajpregu.00107.2016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 10/03/2016] [Accepted: 10/03/2016] [Indexed: 12/22/2022]
Abstract
The effect of hypoxia on cellular metabolism is well documented in adult vertebrates, but information is entirely lacking for embryonic organisms. The effect of hypoxia on embryonic physiology is particularly interesting, as metabolic responses during development may have life-long consequences, due to developmental plasticity. To this end, we investigated the effects of chronic developmental hypoxia on cardiac mitochondrial function in embryonic and juvenile American alligators (Alligator mississippiensis). Alligator eggs were incubated in 21% or 10% oxygen from 20 to 90% of embryonic development. Embryos were either harvested at 90% development or allowed to hatch and then reared in 21% oxygen for 3 yr. Ventricular mitochondria were isolated from embryonic/juvenile alligator hearts. Mitochondrial respiration and enzymatic activities of electron transport chain complexes were measured with a microrespirometer and spectrophotometer, respectively. Developmental hypoxia induced growth restriction and increased relative heart mass, and this phenotype persisted into juvenile life. Embryonic mitochondrial function was not affected by developmental hypoxia, but at the juvenile life stage, animals from hypoxic incubations had lower levels of Leak respiration and higher respiratory control ratios, which is indicative of enhanced mitochondrial efficiency. Our results suggest developmental hypoxia can have life-long consequences for alligator morphology and metabolic function. Further investigations are necessary to reveal the adaptive significance of the enhanced mitochondrial efficiency in the hypoxic phenotype.
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Affiliation(s)
- Gina L J Galli
- Faculty of Medical and Human Sciences, University of Manchester, Manchester, United Kingdom;
| | - Janna Crossley
- Developmental Integrative Biology Research Group, Department of Biological Sciences, University of North Texas, Denton, Texas; and
| | - Ruth M Elsey
- Rockefeller Wildlife Refuge, Grand Chenier, Louisiana
| | - Edward M Dzialowski
- Developmental Integrative Biology Research Group, Department of Biological Sciences, University of North Texas, Denton, Texas; and
| | - Holly A Shiels
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Dane A Crossley
- Developmental Integrative Biology Research Group, Department of Biological Sciences, University of North Texas, Denton, Texas; and
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Faramoushi M, Amir Sasan R, Sari Sarraf V, Karimi P. Cardiac fibrosis and down regulation of GLUT4 in experimental diabetic cardiomyopathy are ameliorated by chronic exposures to intermittent altitude. J Cardiovasc Thorac Res 2016; 8:26-33. [PMID: 27069564 PMCID: PMC4827136 DOI: 10.15171/jcvtr.2016.05] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 03/03/2016] [Indexed: 12/15/2022] Open
Abstract
Introduction: Chronic intermittent hypoxia is considered as a preconditioning status in cardiovascular health to inducing resistance to the low oxygen supply. Diabetic cardiomyopathy leads to inability of the heart to effective circulation of blood preventing of consequent tissue damages so; the aim of this study was elucidation of effect of chronic exposure to hypoxia on Cardiac fibrosis and expression of GLUT4 in experimental diabetic cardiomyopathy.
Methods: A total number of 30 rats were randomly divided into three groups; 1: Normoxia control group (NN, n = 10). 2: Normoxia diabetic group (ND, n = 10) that took fat diet for 2 weeks then were injected by streptozotocin (37 mg/kg) and 3: Hypoxia diabetic group (HD, n = 10): that were exposed to chronic intermittent hypoxia (CIH) (altitude ≈3400 m, 14% oxygen for 8 weeks). After hypoxia challenge, plasma metabolic parameters including: fasting blood glucose (FBS), triglyceride (TG) and total cholesterol (TC) were measured by colorimetric assay. Cardiac expression of GLUT4 protein and cardiac collagen accumulation were determined in the excised left ventricle by western blotting, and Masson trichrome staining respectively.
Results: Based on resultant data, FBS, TG and TC were significantly (P < 0.05) decreased in HD vs. ND. Homeostasis Model Assessment (HOMA) were also significantly attenuated after exposed to CIH in HD group compared to ND group (P < 0.05). Significant increase in packed cell volume and hemoglobin concentration was observed in HD group compared to ND group (P < 0.05). Comparison of heart wet weight between three groups showed a significant difference (P < 0.05) with lower amount in HD and ND versus NN. Myocardial fibrosis was significantly more pronounced in ND when compared to NN. Eight weeks exposure to hypoxia ameliorated this increase in HD group. Intermittent hypoxia significantly increased GLUT4 protein expression in HD compared to ND group (P < 0.05).
Conclusion: Data suggested that CIH might potentiate to improve glucose homeostasis and cardiac tissue structural damages created in type 2 diabetes (T2D).
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Affiliation(s)
- Mahdi Faramoushi
- Department of Physical Education and Sport, Tabriz Islamic Art University, Tabriz, Iran
| | - Ramin Amir Sasan
- Faculty of Physical Education and Sport Sciences, University of Tabriz, Tabriz, Iran
| | - Vahid Sari Sarraf
- Faculty of Physical Education and Sport Sciences, University of Tabriz, Tabriz, Iran
| | - Pouran Karimi
- Neuroscience Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
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Ashmore T, Roberts LD, Morash AJ, Kotwica AO, Finnerty J, West JA, Murfitt SA, Fernandez BO, Branco C, Cowburn AS, Clarke K, Johnson RS, Feelisch M, Griffin JL, Murray AJ. Nitrate enhances skeletal muscle fatty acid oxidation via a nitric oxide-cGMP-PPAR-mediated mechanism. BMC Biol 2015; 13:110. [PMID: 26694920 PMCID: PMC4688964 DOI: 10.1186/s12915-015-0221-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 12/10/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Insulin sensitivity in skeletal muscle is associated with metabolic flexibility, including a high capacity to increase fatty acid (FA) oxidation in response to increased lipid supply. Lipid overload, however, can result in incomplete FA oxidation and accumulation of potentially harmful intermediates where mitochondrial tricarboxylic acid cycle capacity cannot keep pace with rates of β-oxidation. Enhancement of muscle FA oxidation in combination with mitochondrial biogenesis is therefore emerging as a strategy to treat metabolic disease. Dietary inorganic nitrate was recently shown to reverse aspects of the metabolic syndrome in rodents by as yet incompletely defined mechanisms. RESULTS Herein, we report that nitrate enhances skeletal muscle FA oxidation in rodents in a dose-dependent manner. We show that nitrate induces FA oxidation through a soluble guanylate cyclase (sGC)/cGMP-mediated PPARβ/δ- and PPARα-dependent mechanism. Enhanced PPARβ/δ and PPARα expression and DNA binding induces expression of FA oxidation enzymes, increasing muscle carnitine and lowering tissue malonyl-CoA concentrations, thereby supporting intra-mitochondrial pathways of FA oxidation and enhancing mitochondrial respiration. At higher doses, nitrate induces mitochondrial biogenesis, further increasing FA oxidation and lowering long-chain FA concentrations. Meanwhile, nitrate did not affect mitochondrial FA oxidation in PPARα(-/-) mice. In C2C12 myotubes, nitrate increased expression of the PPARα targets Cpt1b, Acadl, Hadh and Ucp3, and enhanced oxidative phosphorylation rates with palmitoyl-carnitine; however, these changes in gene expression and respiration were prevented by inhibition of either sGC or protein kinase G. Elevation of cGMP, via the inhibition of phosphodiesterase 5 by sildenafil, also increased expression of Cpt1b, Acadl and Ucp3, as well as CPT1B protein levels, and further enhanced the effect of nitrate supplementation. CONCLUSIONS Nitrate may therefore be effective in the treatment of metabolic disease by inducing FA oxidation in muscle.
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Affiliation(s)
- Tom Ashmore
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Lee D Roberts
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- MRC-Human Nutrition Research, University of Cambridge, Cambridge, UK
| | - Andrea J Morash
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - Aleksandra O Kotwica
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - John Finnerty
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - James A West
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Steven A Murfitt
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Bernadette O Fernandez
- Faculty of Medicine, Clinical & Experimental Sciences, University of Southampton, Southampton, UK
| | - Cristina Branco
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - Andrew S Cowburn
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - Kieran Clarke
- Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, UK
| | - Randall S Johnson
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - Martin Feelisch
- Faculty of Medicine, Clinical & Experimental Sciences, University of Southampton, Southampton, UK
| | - Julian L Griffin
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- MRC-Human Nutrition Research, University of Cambridge, Cambridge, UK
| | - Andrew J Murray
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK.
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Murray AJ. Energy metabolism and the high-altitude environment. Exp Physiol 2015; 101:23-7. [PMID: 26315373 DOI: 10.1113/ep085317] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 08/20/2015] [Indexed: 01/08/2023]
Abstract
At high altitude the barometric pressure falls, challenging oxygen delivery to the tissues. Thus, whilst hypoxia is not the only physiological stress encountered at high altitude, low arterial P(O2) is a sustained feature, even after allowing adequate time for acclimatization. Cardiac and skeletal muscle energy metabolism is altered in subjects at, or returning from, high altitude. In the heart, energetic reserve falls, as indicated by lower phosphocreatine-to-ATP ratios. The underlying mechanism is unknown, but in the hypoxic rat heart fatty acid oxidation and respiratory capacity are decreased, whilst pyruvate oxidation is also lower after sustained hypoxic exposure. In skeletal muscle, there is not a consensus. With prolonged exposure to extreme high altitude (>5500 m) a loss of muscle mitochondrial density is seen, but this was not observed in a simulated ascent of Everest in hypobaric chambers. At more moderate high altitude, decreased respiratory capacity may occur without changes in mitochondrial volume density, and fat oxidation may be downregulated, although this is not seen in all studies. The underlying mechanisms, including the possible role of hypoxia-signalling pathways, remain to be resolved, particularly in light of confounding factors in the high-altitude environment. In high-altitude-adapted Tibetan natives, however, there is evidence of natural selection centred around the hypoxia-inducible factor pathway, and metabolic features in this population (e.g. low cardiac phosphocreatine-to-ATP ratios, increased cardiac glucose uptake and lower muscle mitochondrial densities) share similarities with those in acclimatized lowlanders, supporting a possible role for the hypoxia-inducible factor pathway in the metabolic response of cardiac and skeletal muscle energy metabolism to high altitude.
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Affiliation(s)
- Andrew J Murray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
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Holloway CJ, Murray AJ, Mitchell K, Martin DS, Johnson AW, Cochlin LE, Codreanu I, Dhillon S, Rodway GW, Ashmore T, Levett DZH, Neubauer S, Montgomery HE, Grocott MPW, Clarke K. Oral Coenzyme Q10 supplementation does not prevent cardiac alterations during a high altitude trek to everest base cAMP. High Alt Med Biol 2015; 15:459-67. [PMID: 24661196 DOI: 10.1089/ham.2013.1053] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Exposure to high altitude is associated with sustained, but reversible, changes in cardiac mass, diastolic function, and high-energy phosphate metabolism. Whilst the underlying mechanisms remain elusive, tissue hypoxia increases generation of reactive oxygen species (ROS), which can stabilize hypoxia-inducible factor (HIF) transcription factors, bringing about transcriptional changes that suppress oxidative phosphorylation and activate autophagy. We therefore investigated whether oral supplementation with an antioxidant, Coenzyme Q10, prevented the cardiac perturbations associated with altitude exposure. Twenty-three volunteers (10 male, 13 female, 46±3 years) were recruited from the 2009 Caudwell Xtreme Everest Research Treks and studied before, and within 48 h of return from, a 17-day trek to Everest Base Camp, with subjects receiving either no intervention (controls) or 300 mg Coenzyme Q10 per day throughout altitude exposure. Cardiac magnetic resonance imaging and echocardiography were used to assess cardiac morphology and function. Following altitude exposure, body mass fell by 3 kg in all subjects (p<0.001), associated with a loss of body fat and a fall in BMI. Post-trek, left ventricular mass had decreased by 11% in controls (p<0.05) and by 16% in Coenzyme Q10-treated subjects (p<0.001), whereas mitral inflow E/A had decreased by 18% in controls (p<0.05) and by 21% in Coenzyme Q10-treated subjects (p<0.05). Coenzyme Q10 supplementation did not, therefore, prevent the loss of left ventricular mass or change in diastolic function that occurred following a trek to Everest Base Camp.
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Affiliation(s)
- Cameron J Holloway
- 1 Department of Physiology, Anatomy and Genetics, University of Oxford , United Kingdom
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44
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Murray AJ, Horscroft JA. Mitochondrial function at extreme high altitude. J Physiol 2015; 594:1137-49. [PMID: 26033622 DOI: 10.1113/jp270079] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/21/2015] [Indexed: 01/01/2023] Open
Abstract
At high altitude, barometric pressure falls and with it inspired P(O2), potentially compromising O2 delivery to the tissues. With sufficient acclimatisation, the erythropoietic response increases red cell mass such that arterial O2 content (C(aO2)) is restored; however arterial P(O2)(P(aO2)) remains low, and the diffusion of O2 from capillary to mitochondrion is impaired. Mitochondrial respiration and aerobic capacity are thus limited, whilst reactive oxygen species (ROS) production increases. Restoration of P(aO2) with supplementary O2 does not fully restore aerobic capacity in acclimatised individuals, possibly indicating a peripheral impairment. With prolonged exposure to extreme high altitude (>5500 m), muscle mitochondrial volume density falls, with a particular loss of the subsarcolemmal population. It is not clear whether this represents acclimatisation or deterioration, but it does appear to be regulated, with levels of the mitochondrial biogenesis factor PGC-1α falling, and shows similarities to adapted Tibetan highlanders. Qualitative changes in mitochondrial function also occur, and do so at more moderate high altitudes with shorter periods of exposure. Electron transport chain complexes are downregulated, possibly mitigating the increase in ROS production. Fatty acid oxidation capacity is decreased and there may be improvements in biochemical coupling at the mitochondrial inner membrane that enhance O2 efficiency. Creatine kinase expression falls, possibly impairing high-energy phosphate transfer from the mitochondria to myofibrils. In climbers returning from the summit of Everest, cardiac energetic reserve (phosphocreatine/ATP) falls, but skeletal muscle energetics are well preserved, possibly supporting the notion that mitochondrial remodelling is a core feature of acclimatisation to extreme high altitude.
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Affiliation(s)
- Andrew J Murray
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - James A Horscroft
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
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O'Brien KA, Griffin JL, Murray AJ, Edwards LM. Mitochondrial responses to extreme environments: insights from metabolomics. EXTREME PHYSIOLOGY & MEDICINE 2015; 4:7. [PMID: 25949809 PMCID: PMC4422479 DOI: 10.1186/s13728-015-0026-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 04/07/2015] [Indexed: 12/12/2022]
Abstract
Humans are capable of survival in a remarkable range of environments, including the extremes of temperature and altitude as well as zero gravity. Investigation into physiological function in response to such environmental stresses may help further our understanding of human (patho-) physiology both at a systems level and in certain disease states, making it a highly relevant field of study. This review focuses on the application of metabolomics in assessing acclimatisation to these states, particularly the insights this approach can provide into mitochondrial function. It includes an overview of metabolomics and the associated analytical tools and also suggests future avenues of research.
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Affiliation(s)
- Katie A O'Brien
- Centre of Human & Aerospace Physiological Sciences, King's College London, London, UK
| | - Julian L Griffin
- MRC Human Nutrition Research Unit, Elsie Widdowson Laboratory, Fulbourn Road, Cambridge, England ; Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, UK
| | - Andrew J Murray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, UK
| | - Lindsay M Edwards
- Centre of Human & Aerospace Physiological Sciences, King's College London, London, UK ; Fibrosis Drug Performance Unit, GlaxoSmithKline Medicines Research Centre, Stevenage, UK
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46
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Lewis P, Sheehan D, Soares R, Varela Coelho A, O'Halloran KD. Chronic sustained hypoxia-induced redox remodeling causes contractile dysfunction in mouse sternohyoid muscle. Front Physiol 2015; 6:122. [PMID: 25941492 PMCID: PMC4403307 DOI: 10.3389/fphys.2015.00122] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 04/02/2015] [Indexed: 12/21/2022] Open
Abstract
Chronic sustained hypoxia (CH) induces structural and functional adaptations in respiratory muscles of animal models, however the underlying molecular mechanisms are unclear. This study explores the putative role of CH-induced redox remodeling in a translational mouse model, with a focus on the sternohyoid—a representative upper airway dilator muscle involved in the control of pharyngeal airway caliber. We hypothesized that exposure to CH induces redox disturbance in mouse sternohyoid muscle in a time-dependent manner affecting metabolic capacity and contractile performance. C57Bl6/J mice were exposed to normoxia or normobaric CH (FiO2 = 0.1) for 1, 3, or 6 weeks. A second cohort of animals was exposed to CH for 6 weeks with and without antioxidant supplementation (tempol or N-acetyl cysteine in the drinking water). Following CH exposure, we performed 2D redox proteomics with mass spectrometry, metabolic enzyme activity assays, and cell-signaling assays. Additionally, we assessed isotonic contractile and endurance properties ex vivo. Temporal changes in protein oxidation and glycolytic enzyme activities were observed. Redox modulation of sternohyoid muscle proteins key to contraction, metabolism and cellular homeostasis was identified. There was no change in redox-sensitive proteasome activity or HIF-1α content, but CH decreased phospho-JNK content independent of antioxidant supplementation. CH was detrimental to sternohyoid force- and power-generating capacity and this was prevented by chronic antioxidant supplementation. We conclude that CH causes upper airway dilator muscle dysfunction due to redox modulation of proteins key to function and homeostasis. Such changes could serve to further disrupt respiratory homeostasis in diseases characterized by CH such as chronic obstructive pulmonary disease. Antioxidants may have potential use as an adjunctive therapy in hypoxic respiratory disease.
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Affiliation(s)
- Philip Lewis
- Department of Physiology, School of Medicine, University College Cork Cork, Ireland
| | - David Sheehan
- School of Biochemistry and Cell Biology, University College Cork Cork, Ireland
| | - Renata Soares
- Instituto de Tecnologia Química e Biológica António Xavier, New University of Lisbon Lisbon, Portugal
| | - Ana Varela Coelho
- Instituto de Tecnologia Química e Biológica António Xavier, New University of Lisbon Lisbon, Portugal
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, University College Cork Cork, Ireland
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Woolcott OO, Ader M, Bergman RN. Glucose homeostasis during short-term and prolonged exposure to high altitudes. Endocr Rev 2015; 36:149-73. [PMID: 25675133 PMCID: PMC4399271 DOI: 10.1210/er.2014-1063] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Most of the literature related to high altitude medicine is devoted to the short-term effects of high-altitude exposure on human physiology. However, long-term effects of living at high altitudes may be more important in relation to human disease because more than 400 million people worldwide reside above 1500 m. Interestingly, individuals living at higher altitudes have a lower fasting glycemia and better glucose tolerance compared with those who live near sea level. There is also emerging evidence of the lower prevalence of both obesity and diabetes at higher altitudes. The mechanisms underlying improved glucose control at higher altitudes remain unclear. In this review, we present the most current evidence about glucose homeostasis in residents living above 1500 m and discuss possible mechanisms that could explain the lower fasting glycemia and lower prevalence of obesity and diabetes in this population. Understanding the mechanisms that regulate and maintain the lower fasting glycemia in individuals who live at higher altitudes could lead to new therapeutics for impaired glucose homeostasis.
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Affiliation(s)
- Orison O Woolcott
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048
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Horscroft JA, Murray AJ. Skeletal muscle energy metabolism in environmental hypoxia: climbing towards consensus. EXTREME PHYSIOLOGY & MEDICINE 2014; 3:19. [PMID: 25473486 PMCID: PMC4253994 DOI: 10.1186/2046-7648-3-19] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 11/03/2014] [Indexed: 01/09/2023]
Abstract
Skeletal muscle undergoes metabolic remodelling in response to environmental hypoxia, yet aspects of this process remain controversial. Broadly, environmental hypoxia has been suggested to induce: (i) a loss of mitochondrial density; (ii) a substrate switch away from fatty acids and towards other substrates such as glucose, amino acids and ketone bodies; and (iii) a shift from aerobic to anaerobic metabolism. There remains a lack of a consensus in these areas, most likely as a consequence of the variations in degree and duration of hypoxic exposure, as well as the broad range of experimental parameters used as markers of metabolic processes. To attempt to resolve some of the controversies, we performed a comprehensive review of the literature pertaining to hypoxia-induced changes in skeletal muscle energy metabolism. We found evidence that mass-specific mitochondrial function is decreased prior to mass-specific mitochondrial density, implicating intra-mitochondrial changes in the response to environmental hypoxia. This loss of oxidative capacity does not appear to be matched by a loss of glycolytic capacity, which on the whole is not altered by environmental hypoxia. Environmental hypoxia does however induce a selective attenuation of fatty acid oxidation, whilst glucose uptake is maintained or increased, perhaps to support glycolysis in the face of a downregulation of oxidative metabolism, optimising the pathways of ATP synthesis for the hypoxic environment.
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Affiliation(s)
- James A Horscroft
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, CB2 3EG Cambridge, UK
| | - Andrew J Murray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, CB2 3EG Cambridge, UK
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Gilbert-Kawai ET, Milledge JS, Grocott MP, Martin DS. King of the Mountains: Tibetan and Sherpa Physiological Adaptations for Life at High Altitude. Physiology (Bethesda) 2014; 29:388-402. [DOI: 10.1152/physiol.00018.2014] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Anecdotal evidence surrounding Tibetans' and Sherpas' exceptional tolerance to hypobaric hypoxia has been recorded since the beginning of high-altitude exploration. These populations have successfully lived and reproduced at high altitude for hundreds of generations with hypoxia as a constant evolutionary pressure. Consequently, they are likely to have undergone natural selection toward a genotype (and phenotype) tending to offer beneficial adaptation to sustained hypoxia. With the advent of translational human hypoxic research, in which genotype/phenotype studies of healthy individuals at high altitude may be of benefit to hypoxemic critically ill patients in a hospital setting, high-altitude natives may provide a valuable and intriguing model. The aim of this review is to provide a comprehensive summary of the scientific literature encompassing Tibetan and Sherpa physiological adaptations to a high-altitude residence. The review demonstrates the extent to which evolutionary pressure has refined the physiology of this high-altitude population. Furthermore, although many physiological differences between highlanders and lowlanders have been found, it also suggests many more potential avenues of investigation.
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Affiliation(s)
- Edward T. Gilbert-Kawai
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, United Kingdom
- University College London Division of Surgery and Interventional Science, Royal Free Hospital, London, United Kingdom
- University College Hospital London NIHR Biomedical Research Centre, London, United Kingdom
| | - James S. Milledge
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, United Kingdom
| | - Michael P.W. Grocott
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, United Kingdom
- University College Hospital London NIHR Biomedical Research Centre, London, United Kingdom
- Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, University of Southampton, Southampton, United Kingdom
- Anaesthesia and Critical Care Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom; and
- Southampton NIHR Respiratory Biomedical Research Unit, Southampton, United Kingdom
| | - Daniel S. Martin
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, United Kingdom
- University College London Division of Surgery and Interventional Science, Royal Free Hospital, London, United Kingdom
- University College Hospital London NIHR Biomedical Research Centre, London, United Kingdom
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Ashmore T, Fernandez BO, Branco-Price C, West JA, Cowburn AS, Heather LC, Griffin JL, Johnson RS, Feelisch M, Murray AJ. Dietary nitrate increases arginine availability and protects mitochondrial complex I and energetics in the hypoxic rat heart. J Physiol 2014; 592:4715-31. [PMID: 25172947 PMCID: PMC4253472 DOI: 10.1113/jphysiol.2014.275263] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 08/18/2014] [Indexed: 12/31/2022] Open
Abstract
Hypoxic exposure is associated with impaired cardiac energetics in humans and altered mitochondrial function, with suppressed complex I-supported respiration, in rat heart. This response might limit reactive oxygen species generation, but at the cost of impaired electron transport chain (ETC) activity. Dietary nitrate supplementation improves mitochondrial efficiency and can promote tissue oxygenation by enhancing blood flow. We therefore hypothesised that ETC dysfunction, impaired energetics and oxidative damage in the hearts of rats exposed to chronic hypoxia could be alleviated by sustained administration of a moderate dose of dietary nitrate. Male Wistar rats (n = 40) were given water supplemented with 0.7 mmol l(-1) NaCl (as control) or 0.7 mmol l(-1) NaNO3, elevating plasma nitrate levels by 80%, and were exposed to 13% O2 (hypoxia) or normoxia (n = 10 per group) for 14 days. Respiration rates, ETC protein levels, mitochondrial density, ATP content and protein carbonylation were measured in cardiac muscle. Complex I respiration rates and protein levels were 33% lower in hypoxic/NaCl rats compared with normoxic/NaCl controls. Protein carbonylation was 65% higher in hearts of hypoxic rats compared with controls, indicating increased oxidative stress, whilst ATP levels were 62% lower. Respiration rates, complex I protein and activity, protein carbonylation and ATP levels were all fully protected in the hearts of nitrate-supplemented hypoxic rats. Both in normoxia and hypoxia, dietary nitrate suppressed cardiac arginase expression and activity and markedly elevated cardiac l-arginine concentrations, unmasking a novel mechanism of action by which nitrate enhances tissue NO bioavailability. Dietary nitrate therefore alleviates metabolic abnormalities in the hypoxic heart, improving myocardial energetics.
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Affiliation(s)
- Tom Ashmore
- Department of Physiology, Development & Neuroscience, University of Cambridge, UK Department of Biochemistry, University of Cambridge, UK
| | | | | | - James A West
- Department of Biochemistry, University of Cambridge, UK MRC-Human Nutrition Research, Elsie Widdowson Laboratory, Cambridge, UK
| | - Andrew S Cowburn
- Department of Physiology, Development & Neuroscience, University of Cambridge, UK
| | - Lisa C Heather
- Department of Physiology, Anatomy & Genetics, University of Oxford, UK
| | - Julian L Griffin
- Department of Biochemistry, University of Cambridge, UK MRC-Human Nutrition Research, Elsie Widdowson Laboratory, Cambridge, UK
| | - Randall S Johnson
- Department of Physiology, Development & Neuroscience, University of Cambridge, UK
| | - Martin Feelisch
- Faculty of Medicine, Clinical & Experimental Sciences, University of Southampton, UK
| | - Andrew J Murray
- Department of Physiology, Development & Neuroscience, University of Cambridge, UK
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