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Xu X, Leforestier R, Xia D, Block KT, Feng L. MRI of GlycoNOE in the human liver using GraspNOE-Dixon. Magn Reson Med 2024. [PMID: 39367632 DOI: 10.1002/mrm.30270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 08/06/2024] [Accepted: 08/07/2024] [Indexed: 10/06/2024]
Abstract
PURPOSE The objective of this study was to develop a new MRI technique for non-invasive, free-breathing imaging of glycogen in the human liver using the nuclear Overhauser effect (NOE). METHODS The proposed method, called GraspNOE-Dixon, uses a novel MRI sequence that combines steady-state saturation-transfer preparation with multi-echo golden-angle radial stack-of-stars sampling. Multi-echo acquisition enables fat/water-separated imaging for quantification of water-specific NOE. Image reconstruction is performed using the improved golden-angle radial sparse parallel imaging (GRASP-Pro) technique to exploit spatiotemporal correlations in dynamic images. To evaluate the proposed technique, imaging experiments were first performed on glycogen phantoms, followed by in vivo studies involving healthy volunteers and patients with fatty liver disease. In addition, a comparative assessment of signal changes before and after a 12-h fasting period was performed. RESULTS Evaluation experiments on glycogen phantoms showed a robust linear correlation between the NOE signal and glycogen concentration. In vivo experiments demonstrated motion-robust NOE-weighted images, with potential for further acceleration. In subjects with varying liver fat content, the fat/water separation approach resulted in distortion-free Z-spectra, enabling the quantification of glycogen NOE. An approximately one-third reduction in the NOE signal was observed following a 12-h fasting period, consistent with a decrease in glycogen level. CONCLUSION This study introduces a clinically feasible imaging technique, GraspNOE-Dixon, for free-breathing volumetric multi-echo imaging of hepatic glycogen at 3 T. The motion robust imaging technique developed here may also have applications in other body areas beyond liver imaging.
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Affiliation(s)
- Xiang Xu
- BioMedical Engineering and Imaging Institute (BMEII), Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Diagnostic, Molecular and Interventional Radiology, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Rodolphe Leforestier
- BioMedical Engineering and Imaging Institute (BMEII), Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Diagnostic, Molecular and Interventional Radiology, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Ding Xia
- BioMedical Engineering and Imaging Institute (BMEII), Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Diagnostic, Molecular and Interventional Radiology, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Kai Tobias Block
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Li Feng
- BioMedical Engineering and Imaging Institute (BMEII), Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Diagnostic, Molecular and Interventional Radiology, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, New York, USA
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Arevalo JA, Leija RG, Osmond AD, Curl CC, Duong JJ, Huie MJ, Masharani U, Brooks GA. Delayed and diminished postprandial lactate shuttling in healthy older men and women. Am J Physiol Endocrinol Metab 2024; 327:E430-E440. [PMID: 39110417 PMCID: PMC11482286 DOI: 10.1152/ajpendo.00183.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 07/22/2024] [Accepted: 07/30/2024] [Indexed: 09/19/2024]
Abstract
Lactate, a product of glycolysis, is formed under aerobic conditions. Extensive work has shown lactate flux in young and exercising humans; however, the effect of age is not known. We tested the hypothesis that postprandial lactate shuttling (PLS) would be diminished in older adults. We used [3-13C]lactate and [6,6-2H]glucose tracers, an oral glucose tolerance test (OGTT), and arterialized blood sampling to determine postprandial lactate rates of appearance (Ra), disappearance (Rd), and oxidation (Rox) in 15 young (28.1 ± 1.4 yr) and 13 older (70.6 ± 2.4 yr) healthy men and women. In young participants, fasting blood [lactate] (≈0.5 mM) rose after the glucose challenge, peaked at 15 min, dipped to a nadir at 30 min, and rose again peaking at 60 min (≈1.0 mM). Initial responses in lactate Ra of older participants were delayed and diminished until 90 min rising by 0.83 mg·kg-1·min-1. Lactate Rox was higher throughout the entire trial in young participants by a difference of ∼0.5 mg·kg-1·min-1. Initial peaks in lactate Ra and concentration in all volunteers demonstrated the presence of an enteric PLS following an OGTT. Notably, in the systemic, but not enteric, PLS phase, lactate Ra correlated highly with glucose Rd (r2 = 0.92). Correspondence of second peaks in lactate Ra and concentration and glucose Rd shows dependence of lactate Ra on glucose Rd. Although results show both enteric and systemic PLS phases in young and older study cohorts, metabolic responses were delayed and diminished in healthy older individuals.NEW & NOTEWORTHY We used isotope tracers, an oral glucose tolerance test, and arterialized blood sampling to determine postprandial lactate flux rates in healthy young and older men and women. Lactate rates of appearance and oxidation and the lactate-pyruvate exchange were delayed and diminished in both enteric and systemic postprandial lactate shuttle phases in older participants.
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Affiliation(s)
- Jose A. Arevalo
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, United States
| | - Robert G. Leija
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, United States
| | - Adam D. Osmond
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, United States
| | - Casey C. Curl
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, United States
| | - Justin J. Duong
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, United States
| | - Melvin J. Huie
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, United States
| | - Umesh Masharani
- Department of Medicine, University of California, San Francisco, United States
| | - George A. Brooks
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, United States
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Curl CC, Leija RG, Arevalo JA, Osmond AD, Duong JJ, Huie MJ, Masharani U, Horning MA, Brooks GA. Altered glucose kinetics occurs with aging: a new outlook on metabolic flexibility. Am J Physiol Endocrinol Metab 2024; 327:E217-E228. [PMID: 38895979 PMCID: PMC11427093 DOI: 10.1152/ajpendo.00091.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 06/11/2024] [Accepted: 06/11/2024] [Indexed: 06/21/2024]
Abstract
Our purpose was to determine how age affects metabolic flexibility and underlying glucose kinetics in healthy young and older adults. Therefore, glucose and lactate tracers along with pulmonary gas exchange data were used to determine glucose kinetics and respiratory exchange ratios [RER = carbon dioxide production (V̇co2)/oxygen consumption (V̇o2)] during a 2-h 75-g oral glucose tolerance test (OGTT). After an 12-h overnight fast, 28 participants, 15 young (21-35 yr; 7 men and 8 women) and 13 older (60-80 yr; 7 men and 6 women), received venous primed-continuous infusions of [6,6-2H]glucose and [3-13C]lactate with a [Formula: see text] bolus. After a 90-min metabolic stabilization and tracer equilibration period, volunteers underwent an OGTT. Arterialized glucose concentrations ([glucose]) started to rise 15 min post glucose consumption, peaked at 60 min, and remained elevated. As assessed by rates of appearance (Ra) and disposal (Rd) and metabolic clearance rate (MCR), glucose kinetics were suppressed in older compared to young individuals. As well, unlike in young individuals, fractional gluconeogenesis (fGNG) remained elevated in the older population after the oral glucose challenge. Finally, there were no differences in 12-h fasting baseline or peak RER values following an oral glucose challenge in older compared to young men and women, making RER an incomplete measure of metabolic flexibility in the volunteers we evaluated. Our study revealed that glucose kinetics are significantly altered in a healthy aged population after a glucose challenge. Furthermore, those physiological deficits are not detected from changes in RER during an OGTT.NEW & NOTEWORTHY To determine metabolic flexibility in response to an OGTT, we studied healthy young and older men and women to determine glucose kinetics and changes in RER. Compared to young subjects, glucose kinetics were suppressed in older healthy individuals during an OGTT. Surprisingly, the age-related changes in glucose flux were not reflected in RER measurements; thus, RER measurements do not give a complete view of metabolic flexibility in healthy individuals.
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Affiliation(s)
- Casey C Curl
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
| | - Robert G Leija
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
| | - Jose A Arevalo
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
| | - Adam D Osmond
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
| | - Justin J Duong
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
| | - Melvin J Huie
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
| | - Umesh Masharani
- Department of Endocrinology, School of Medicine, University of California, San Francisco, California, United States
| | - Michael A Horning
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
| | - George A Brooks
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
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Leija RG, Curl CC, Arevalo JA, Osmond AD, Duong JJ, Huie MJ, Masharani U, Brooks GA. Enteric and systemic postprandial lactate shuttle phases and dietary carbohydrate carbon flow in humans. Nat Metab 2024; 6:670-677. [PMID: 38388706 PMCID: PMC11052717 DOI: 10.1038/s42255-024-00993-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 01/24/2024] [Indexed: 02/24/2024]
Abstract
Dietary glucose in excess is stored in the liver in the form of glycogen. As opposed to direct conversion of glucose into glycogen, the hypothesis of the postprandial lactate shuttle (PLS) proposes that dietary glucose uptake is metabolized to lactate in the gut, thereby being transferred to the liver for glycogen storage. In the present study, we provide evidence of a PLS in young healthy men and women. Overnight fasted participants underwent an oral glucose tolerance test, and arterialized lactate concentration and rate of appearance were determined. The concentration of lactate in the blood rose before the concentration of glucose, thus providing evidence of an enteric PLS. Secondary increments in the concentration of lactate in the blood and its rate of appearance coincided with those of glucose, which indicates the presence of a larger, secondary, systemic PLS phase driven by hepatic glucose release. The present study challenges the notion that lactate production is the result of hypoxia in skeletal muscles, because our work indicates that glycolysis proceeds to lactate in fully aerobic tissues and dietary carbohydrate is processed via lactate shuttling. Our study proposes that, in humans, lactate is a major vehicle for carbohydrate carbon distribution and metabolism.
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Affiliation(s)
- Robert G Leija
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Casey C Curl
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Jose A Arevalo
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Adam D Osmond
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Justin J Duong
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Melvin J Huie
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Umesh Masharani
- Department of Medicine, University of California, San Francisco, CA, USA
| | - George A Brooks
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, USA.
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Qian Y, Wong VWS, Wang YX, Hou J, Jiang B, Zhang X, Wong GLH, Chan Q, Yu SCH, Chu WCW, Chen W. Dynamic Glucose-Enhanced Imaging of the Liver Using Breath-Hold Black Blood Quantitative T 1ρ MRI at 3.0 T. J Magn Reson Imaging 2024; 59:1107-1109. [PMID: 37317614 DOI: 10.1002/jmri.28829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/15/2023] [Accepted: 05/17/2023] [Indexed: 06/16/2023] Open
Abstract
Evidence Level1Technical Efficacy Stage3
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Affiliation(s)
- Yurui Qian
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong, China
| | - Vincent W S Wong
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China
| | - Yi-Xiang Wang
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong, China
| | - Jian Hou
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong, China
| | - Baiyan Jiang
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong, China
- Illuminatio Medical Technology Limited, Hong Kong, China
| | - Xinrong Zhang
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China
| | - Grace L H Wong
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China
| | | | - Simon C H Yu
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong, China
| | - Winnie C W Chu
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong, China
| | - Weitian Chen
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong, China
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Qi YM, Xiao EH. Advances in application of novel magnetic resonance imaging technologies in liver disease diagnosis. World J Gastroenterol 2023; 29:4384-4396. [PMID: 37576700 PMCID: PMC10415971 DOI: 10.3748/wjg.v29.i28.4384] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 07/03/2023] [Accepted: 07/07/2023] [Indexed: 07/26/2023] Open
Abstract
Liver disease is a major health concern globally, with high morbidity and mor-tality rates. Precise diagnosis and assessment are vital for guiding treatment approaches, predicting outcomes, and improving patient prognosis. Magnetic resonance imaging (MRI) is a non-invasive diagnostic technique that has been widely used for detecting liver disease. Recent advancements in MRI technology, such as diffusion weighted imaging, intravoxel incoherent motion, magnetic resonance elastography, chemical exchange saturation transfer, magnetic resonance spectroscopy, hyperpolarized MR, contrast-enhanced MRI, and ra-diomics, have significantly improved the accuracy and effectiveness of liver disease diagnosis. This review aims to discuss the progress in new MRI technologies for liver diagnosis. By summarizing current research findings, we aim to provide a comprehensive reference for researchers and clinicians to optimize the use of MRI in liver disease diagnosis and improve patient prognosis.
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Affiliation(s)
- Yi-Ming Qi
- Department of Radiology, The Second Xiangya Hospital of Central South University, Changsha 410000, Hunan Province, China
| | - En-Hua Xiao
- Department of Radiology, The Second Xiangya Hospital of Central South University, Changsha 410000, Hunan Province, China
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7
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Brooks GA. What the Lactate Shuttle Means for Sports Nutrition. Nutrients 2023; 15:2178. [PMID: 37432330 DOI: 10.3390/nu15092178] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/29/2023] [Accepted: 04/30/2023] [Indexed: 07/12/2023] Open
Abstract
The discovery of the lactate shuttle (LS) mechanism may have two opposite perceptions, It may mean very little, because the body normally and inexorably uses the LS mechanism. On the contrary, one may support the viewpoint that understanding the LS mechanism offers immense opportunities for understanding nutrition and metabolism in general, as well as in a sports nutrition supplementation setting. In fact, regardless of the specific form of the carbohydrate (CHO) nutrient taken, the bodily CHO energy flux is from a hexose sugar glucose or glucose polymer (glycogen and starches) to lactate with subsequent somatic tissue oxidation or storage as liver glycogen. In fact, because oxygen and lactate flow together through the circulation to sites of utilization, the bodily carbon energy flow is essentially the lactate disposal rate. Consequently, one can consume glucose or glucose polymers in various forms (glycogen, maltodextrin, potato, corn starch, and fructose or high-fructose corn syrup), and the intestinal wall, liver, integument, and active and inactive muscles make lactate which is the chief energy fuel for red skeletal muscle, heart, brain, erythrocytes, and kidneys. Therefore, if one wants to hasten the delivery of CHO energy delivery, instead of providing CHO foods, supplementation with lactate nutrient compounds can augment body energy flow.
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Affiliation(s)
- George A Brooks
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
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Shestov AA, Nath K, Nelson DS, Wasik MA, Glickson JD. Bonded cumomer analysis of tumor metabolism based on 13 C magnetic resonance spectroscopy. NMR IN BIOMEDICINE 2023; 36:e4716. [PMID: 35196744 DOI: 10.1002/nbm.4716] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 02/09/2022] [Accepted: 02/21/2022] [Indexed: 06/14/2023]
Abstract
Bonded cumomers are sets of isotopomers of 13 C-labeled metabolites containing a particular sequence of contiguously or singly labeled carbon atoms. Only these isotopomers contribute to multiplet structure in the 13 C NMR spectrum. We discuss the application of this technique to the study of quantitative tumor metabolism, bioenergetics, and the Warburg effect. The advantages and sensitivity of bonded cumomer analysis over positional enrichment analysis are discussed. When sensitivity requirements are met, bonded cumomer analysis enables the extraction of fluxes through specific metabolic pathways with higher precision. In conjunction with isotopomer control analysis, we evaluate the sensitivity of experimentally measurable metabolite multiplets to determine the robustness of flux analysis in 13 C spectra of tumors. This review examines the role of glycolytic and tricarboxylic acid cycle metabolism with special emphasis on flux through the pentose phosphate pathway (PPP). The impact of reversibility of the nonoxidative branch of the PPP with various 13 C glucose tracers on fine-structure multiplets is analyzed.
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Affiliation(s)
- Alexander A Shestov
- Perelman School of Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kavindra Nath
- Perelman School of Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - David S Nelson
- Perelman School of Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mariusz A Wasik
- Department of Pathology, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA
| | - Jerry D Glickson
- Perelman School of Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Perelman School of Medicine, Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Brooks GA, Osmond AD, Arevalo JA, Duong JJ, Curl CC, Moreno-Santillan DD, Leija RG. Lactate as a myokine and exerkine: drivers and signals of physiology and metabolism. J Appl Physiol (1985) 2023; 134:529-548. [PMID: 36633863 PMCID: PMC9970662 DOI: 10.1152/japplphysiol.00497.2022] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
No longer viewed as a metabolic waste product and cause of muscle fatigue, a contemporary view incorporates the roles of lactate in metabolism, sensing and signaling in normal as well as pathophysiological conditions. Lactate exists in millimolar concentrations in muscle, blood, and other tissues and can rise more than an order of magnitude as the result of increased production and clearance limitations. Lactate exerts its powerful driver-like influence by mass action, redox change, allosteric binding, and other mechanisms described in this article. Depending on the condition, such as during rest and exercise, following carbohydrate nutrition, injury, or pathology, lactate can serve as a myokine or exerkine with autocrine-, paracrine-, and endocrine-like functions that have important basic and translational implications. For instance, lactate signaling is: involved in reproductive biology, fueling the heart, muscle adaptation, and brain executive function, growth and development, and a treatment for inflammatory conditions. Lactate also works with many other mechanisms and factors in controlling cardiac output and pulmonary ventilation during exercise. Ironically, lactate can be disruptive of normal processes such as insulin secretion when insertion of lactate transporters into pancreatic β-cell membranes is not suppressed, and in carcinogenesis when factors that suppress carcinogenesis are inhibited, whereas factors that promote carcinogenesis are upregulated. Lactate signaling is important in areas of intermediary metabolism, redox biology, mitochondrial biogenesis, neurobiology, gut physiology, appetite regulation, nutrition, and overall health and vigor. The various roles of lactate as a myokine and exerkine are reviewed.NEW & NOTEWORTHY Lactate sensing and signaling is a relatively new and rapidly changing field. As a physiological signal lactate works both independently and in concert with other signals. Lactate operates via covalent binding and canonical signaling, redox change, and lactylation of DNA. Lactate can also serve as an element of feedback loops in cardiopulmonary regulation. From conception through aging lactate is not the only a myokine or exerkine, but it certainly deserves consideration as a physiological signal.
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Affiliation(s)
- George A Brooks
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
| | - Adam D Osmond
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
| | - Jose A Arevalo
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
| | - Justin J Duong
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
| | - Casey C Curl
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
| | - Diana D Moreno-Santillan
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
| | - Robert G Leija
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, California, United States
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Magnetic Resonance Imaging and Spectroscopy Methods to Study Hepatic Glucose Metabolism and Their Applications in the Healthy and Diabetic Liver. Metabolites 2022; 12:metabo12121223. [PMID: 36557261 PMCID: PMC9788351 DOI: 10.3390/metabo12121223] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
The liver plays an important role in whole-body glucose homeostasis by taking up glucose from and releasing glucose into the blood circulation. In the postprandial state, excess glucose in the blood circulation is stored in hepatocytes as glycogen. In the postabsorptive state, the liver produces glucose by breaking down glycogen and from noncarbohydrate precursors such as lactate. In metabolic diseases such as diabetes, these processes are dysregulated, resulting in abnormal blood glucose levels. Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) are noninvasive techniques that give unique insight into different aspects of glucose metabolism, such as glycogenesis, glycogenolysis, and gluconeogenesis, in the liver in vivo. Using these techniques, liver glucose metabolism has been studied in regard to a variety of interventions, such as fasting, meal intake, and exercise. Moreover, deviations from normal hepatic glucose metabolism have been investigated in both patients with type 1 and 2 diabetes, as well as the effects of antidiabetic medications. This review provides an overview of current MR techniques to measure hepatic glucose metabolism and the insights obtained by the application of these techniques in the healthy and diabetic liver.
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11
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Non-Invasive Analysis of Human Liver Metabolism by Magnetic Resonance Spectroscopy. Metabolites 2021; 11:metabo11110751. [PMID: 34822409 PMCID: PMC8623827 DOI: 10.3390/metabo11110751] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 10/26/2021] [Accepted: 10/26/2021] [Indexed: 11/16/2022] Open
Abstract
The liver is a key node of whole-body nutrient and fuel metabolism and is also the principal site for detoxification of xenobiotic compounds. As such, hepatic metabolite concentrations and/or turnover rates inform on the status of both hepatic and systemic metabolic diseases as well as the disposition of medications. As a tool to better understand liver metabolism in these settings, in vivo magnetic resonance spectroscopy (MRS) offers a non-invasive means of monitoring hepatic metabolic activity in real time both by direct observation of concentrations and dynamics of specific metabolites as well as by observation of their enrichment by stable isotope tracers. This review summarizes the applications and advances in human liver metabolic studies by in vivo MRS over the past 35 years and discusses future directions and opportunities that will be opened by the development of ultra-high field MR systems and by hyperpolarized stable isotope tracers.
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12
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Nuñez-Peralta C, Montesinos P, Alonso-Jiménez A, Alonso-Pérez J, Reyes-Leiva D, Sánchez-González J, Llauger-Roselló J, Segovia S, Belmonte I, Pedrosa I, Martínez-Noguera A, Matellini-Mosca B, Walter G, Díaz-Manera J. Magnetization Transfer Ratio in Lower Limbs of Late Onset Pompe Patients Correlates With Intramuscular Fat Fraction and Muscle Function Tests. Front Neurol 2021; 12:634766. [PMID: 33796064 PMCID: PMC8009135 DOI: 10.3389/fneur.2021.634766] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 02/01/2021] [Indexed: 11/23/2022] Open
Abstract
Objectives: Magnetization transfer (MT) imaging exploits the interaction between bulk water protons and protons contained in macromolecules to induce signal changes through a special radiofrequency pulse. MT detects muscle damage in patients with neuromuscular conditions, such as limb-girdle muscular dystrophies or Charcot-Marie-Tooth disease, which are characterized by progressive fiber loss and replacement by fatty tissue. In Pompe disease, in which there is, in addition, an accumulation of glycogen inside the muscle fibers, MT has not been tested yet. Our aim is to estimate MT ratio (MTR) in the skeletal muscle of these patients and correlate it with intramuscular fat fraction (FF) and results of muscle function tests. Methods: We obtained two-point axial Dixon and Dixon-MT sequences of the right thigh on a 1.5 Teslas MRI scanner in 60 individuals, including 29 late onset Pompe disease patients, 2 patients with McArdle disease, and 29 age and sex matched healthy controls. FF and MTR were estimated. Muscle function using several muscle function tests, including quantification of muscle strength, timed test quality of life scales, conventional spirometry obtaining forced vital capacity while sitting and in the supine position, were assessed in all patients. Results: MTR was significantly lower in Pompe patients compared with controls (45.5 ± 8.5 vs. 51.7 ± 2.3, Student T-test, p < 0.05). There was a negative correlation between the MTR and FF muscles studied (correlation coefficient: −0.65, Spearman test: p < 0.05). MTR correlated with most of the muscle function test results. We analyzed if there was any difference in MTR values between Pompe patients and healthy controls in those muscles that did not have an increase in fat, a measure that could be related to the presence of glycogen in skeletal muscles, but we did not identify significant differences except in the adductor magnus muscle (48.4 ± 3.6 in Pompe vs. 51 ± 1.3 in healthy controls, Student T-test = 0.023). Conclusions: MTR is a sensitive tool to identify muscle loss in patients with Pompe disease and shows a good correlation with muscle function tests. Therefore, the MT technique can be useful in monitoring muscle degeneration in Pompe disease in clinical trials or natural history studies.
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Affiliation(s)
| | | | - Alicia Alonso-Jiménez
- Neuromuscular Reference Center, Neurology Department, University Hospital of Antwerp, Edegem, Belgium
| | - Jorge Alonso-Pérez
- Neuromuscular Disorders Unit, Neurology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - David Reyes-Leiva
- Neuromuscular Disorders Unit, Neurology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | | | | | - Sonia Segovia
- Neuromuscular Disorders Unit, Neurology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Izaskun Belmonte
- Rehabilitation Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Irene Pedrosa
- Rehabilitation Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | | | | | - Glenn Walter
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States
| | - Jordi Díaz-Manera
- Neuromuscular Disorders Unit, Neurology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain.,John Walton Muscular Dystrophy Research Center, Newcastle University, Newcastle upon Tyne, United Kingdom
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13
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Brooks GA, Arevalo JA, Osmond AD, Leija RG, Curl CC, Tovar AP. Lactate in contemporary biology: a phoenix risen. J Physiol 2021; 600:1229-1251. [PMID: 33566386 PMCID: PMC9188361 DOI: 10.1113/jp280955] [Citation(s) in RCA: 90] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 01/21/2021] [Indexed: 12/13/2022] Open
Abstract
After a century, it's time to turn the page on understanding of lactate metabolism and appreciate that lactate shuttling is an important component of intermediary metabolism in vivo. Cell‐cell and intracellular lactate shuttles fulfil purposes of energy substrate production and distribution, as well as cell signalling under fully aerobic conditions. Recognition of lactate shuttling came first in studies of physical exercise where the roles of driver (producer) and recipient (consumer) cells and tissues were obvious. Moreover, the presence of lactate shuttling as part of postprandial glucose disposal and satiety signalling has been recognized. Mitochondrial respiration creates the physiological sink for lactate disposal in vivo. Repeated lactate exposure from regular exercise results in adaptive processes such as mitochondrial biogenesis and other healthful circulatory and neurological characteristics such as improved physical work capacity, metabolic flexibility, learning, and memory. The importance of lactate and lactate shuttling in healthful living is further emphasized when lactate signalling and shuttling are dysregulated as occurs in particular illnesses and injuries. Like a phoenix, lactate has risen to major importance in 21st century biology.
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Affiliation(s)
- George A Brooks
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Jose A Arevalo
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Adam D Osmond
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Robert G Leija
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Casey C Curl
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Ashley P Tovar
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, USA
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14
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Topping GJ, Heid I, Trajkovic-Arsic M, Kritzner L, Grashei M, Hundshammer C, Aigner M, Skinner JG, Braren R, Schilling F. Hyperpolarized 13C Spectroscopy with Simple Slice-and-Frequency-Selective Excitation. Biomedicines 2021; 9:biomedicines9020121. [PMID: 33513763 PMCID: PMC7911979 DOI: 10.3390/biomedicines9020121] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/16/2021] [Accepted: 01/23/2021] [Indexed: 01/01/2023] Open
Abstract
Hyperpolarized 13C nuclear magnetic resonance spectroscopy can characterize in vivo tissue metabolism, including preclinical models of cancer and inflammatory disease. Broad bandwidth radiofrequency excitation is often paired with free induction decay readout for spectral separation, but quantification of low-signal downstream metabolites using this method can be impeded by spectral peak overlap or when frequency separation of the detected peaks exceeds the excitation bandwidth. In this work, alternating frequency narrow bandwidth (250 Hz) slice-selective excitation was used for 13C spectroscopy at 7 T in a subcutaneous xenograft rat model of human pancreatic cancer (PSN1) to improve quantification while measuring the dynamics of injected hyperpolarized [1-13C]lactate and its metabolite [1-13C]pyruvate. This method does not require sophisticated pulse sequences or specialized radiofrequency and gradient pulses, but rather uses nominally spatially offset slices to produce alternating frequency excitation with simpler slice-selective radiofrequency pulses. Additionally, point-resolved spectroscopy was used to calibrate the 13C frequency from the thermal proton signal in the target region. This excitation scheme isolates the small [1-13C]pyruvate peak from the similar-magnitude tail of the much larger injected [1-13C]lactate peak, facilitates quantification of the [1-13C]pyruvate signal, simplifies data processing, and could be employed for other substrates and preclinical models.
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Affiliation(s)
- Geoffrey J. Topping
- Department of Nuclear Medicine, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (G.J.T.); (M.G.); (C.H.); (M.A.); (J.G.S.)
| | - Irina Heid
- Institute of Diagnostic and Interventional Radiology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (I.H.); (L.K.); (R.B.)
| | - Marija Trajkovic-Arsic
- Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK, Partner Site Essen), 45147 Essen, Germany;
- German Cancer Research Center, DKFZ, 69120 Heidelberg, Germany
- Institute of Developmental Cancer Therapeutics, West German Cancer Center, University Hospital Essen, 45147 Essen, Germany
| | - Lukas Kritzner
- Institute of Diagnostic and Interventional Radiology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (I.H.); (L.K.); (R.B.)
| | - Martin Grashei
- Department of Nuclear Medicine, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (G.J.T.); (M.G.); (C.H.); (M.A.); (J.G.S.)
| | - Christian Hundshammer
- Department of Nuclear Medicine, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (G.J.T.); (M.G.); (C.H.); (M.A.); (J.G.S.)
| | - Maximilian Aigner
- Department of Nuclear Medicine, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (G.J.T.); (M.G.); (C.H.); (M.A.); (J.G.S.)
| | - Jason G. Skinner
- Department of Nuclear Medicine, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (G.J.T.); (M.G.); (C.H.); (M.A.); (J.G.S.)
| | - Rickmer Braren
- Institute of Diagnostic and Interventional Radiology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (I.H.); (L.K.); (R.B.)
- German Cancer Consortium (DKTK, Partner Site Munich), 81675 Munich, Germany
| | - Franz Schilling
- Department of Nuclear Medicine, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (G.J.T.); (M.G.); (C.H.); (M.A.); (J.G.S.)
- Correspondence:
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