1
|
Activated Brown Adipose Tissue Releases Exosomes Containing Mitochondrial Methylene Tetrahydrofolate Dehydrogenase (NADP-dependent) 1-Like Protein (MTHFD1L). Biosci Rep 2022; 42:231255. [PMID: 35502767 PMCID: PMC9142831 DOI: 10.1042/bsr20212543] [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: 11/13/2021] [Revised: 04/05/2022] [Accepted: 04/29/2022] [Indexed: 11/29/2022] Open
Abstract
Brown adipose tissue (BAT) is a promising weapon to combat obesity and metabolic disease. BAT is thermogenic and consumes substantial amounts of glucose and fatty acids as fuel for thermogenesis and energy expenditure. To study BAT function in large human longitudinal cohorts, safe and precise detection methodologies are needed. Although regarded a gold standard, the foray of PET-CT into BAT research and clinical applications is limited by its high ionizing radiation doses. Here, we show that brown adipocytes release exosomes in blood plasma that can be utilized to assess BAT activity. In the present study, we investigated circulating protein biomarkers that can accurately and reliably reflect BAT activation triggered by cold exposure, capsinoids ingestion and thyroid hormone excess in humans. We discovered an exosomal protein, methylene tetrahydrofolate dehydrogenase (NADP+ dependent) 1-like (MTHFD1L), to be overexpressed and detectable in plasma for all three modes of BAT activation in human subjects. This mitochondrial protein is packaged as a cargo within multivesicular bodies of the endosomal compartment and secreted as exosomes via exocytosis from activated brown adipocytes into the circulation. To support MTHFD1L as a conserved BAT activation response in other vertebrates, we examined a rodent model and also proved its presence in blood of rats following BAT activation by cold exposure. Plasma concentration of exosomal MTHFD1L correlated with human BAT activity as confirmed by PET-MR in humans and supported by data from rats. Thus, we deduce that MTHFD1L appears to be overexpressed in activated BAT compared to BAT in the basal nonstimulated state.
Collapse
|
2
|
Niwayama M, Unno N. Tissue Oximeter with Selectable Measurement Depth Using Spatially Resolved Near-Infrared Spectroscopy. SENSORS 2021; 21:s21165573. [PMID: 34451015 PMCID: PMC8402253 DOI: 10.3390/s21165573] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/14/2021] [Accepted: 08/16/2021] [Indexed: 12/19/2022]
Abstract
Tissue oxygenation sensing at a few millimeters deep is useful for surgical and postoperative management. However, the measurement sensitivity at each depth and the proper sensor combination have not been clarified. Here, the measurement characteristics of oximetry by spatially resolved near-infrared spectroscopy were analyzed using Monte Carlo simulation and phantom experiment. From summing the sensitivities of each depth, it was quantitatively found that the measurement sensitivity curve had a peak, and the measurement depth can be adjusted by combining the two distances between the light source and the detector. Furthermore, the gastric tissue was 10–20% smaller in terms of measurement depth than the skin-subcutaneous tissue. A miniaturized oximeter was prototyped so that it could be used in combination with an endoscope or laparoscope. The optical probes consisted of light emitting diodes with wavelengths of 770 nm and 830 nm and photodetectors located 3 to 30 mm from the light source. Phantom experiments using the probes demonstrated the tendency of theoretical analysis. These results suggest the possibility of measuring tissue oxygen saturation with a selectable measurement depth. This selectable method will be useful for obtaining oxygenation information at a depth of 2–5 mm, which is difficult to measure using only laparoscopic surface imaging.
Collapse
Affiliation(s)
- Masatsugu Niwayama
- Graduate School of Medical Photonics, Shizuoka University, Hamamatsu 432-8561, Japan
- Correspondence: ; Tel.: +81-534781615
| | - Naoki Unno
- Division of Vascular Surgery, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan;
| |
Collapse
|
3
|
Santhanam P, Rowe SP, Solnes LB, Quainoo B, Ahima RS. A systematic review of imaging studies of human brown adipose tissue. Ann N Y Acad Sci 2021; 1495:5-23. [PMID: 33604891 DOI: 10.1111/nyas.14579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 01/25/2021] [Accepted: 01/31/2021] [Indexed: 02/06/2023]
Abstract
Brown adipose tissue (BAT) is involved in energy dissipation and has been linked to weight loss, insulin sensitivity, and reduced risk of atherosclerotic disease. BAT is found most often in the supraclavicular region, as well as mediastinal and paravertebral areas, and it is predominantly seen in young persons. BAT is activated by cold temperature and the sympathetic nervous system. In humans, BAT was initially detected via 2-deoxy-2-[18 F]fluoro-d-glucose (FDG) positron emission tomography/computed tomography (PET/CT), a high-resolution molecular imaging modality used to identify and stage malignancies. Recent studies have shown that BAT can be localized using conventional imaging modalities, such as CT or magnetic resonance imaging, as well as radiotracers used for single-photon emission CT. In this systematic review, we have summarized the evidence for BAT detection in humans using various imaging techniques.
Collapse
Affiliation(s)
- Prasanna Santhanam
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Asthma and Allergy Center, Baltimore, Maryland
| | - Steven P Rowe
- Division of Nuclear Medicine, Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Lilja B Solnes
- Division of Nuclear Medicine, Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Brittany Quainoo
- Columbian College of Arts and Sciences, George Washington University, Washington, DC
| | - Rexford S Ahima
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Asthma and Allergy Center, Baltimore, Maryland
| |
Collapse
|
4
|
Functional characterization of human brown adipose tissue metabolism. Biochem J 2020; 477:1261-1286. [PMID: 32271883 DOI: 10.1042/bcj20190464] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 02/07/2023]
Abstract
Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.
Collapse
|
5
|
Brasil S, Renck AC, de Meneck F, Brioschi ML, Costa EF, Teixeira MJ. A systematic review on the role of infrared thermography in the Brown adipose tissue assessment. Rev Endocr Metab Disord 2020; 21:37-44. [PMID: 31965434 DOI: 10.1007/s11154-020-09539-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Brown adipose tissue (BAT) is an endocrine adipose tissue with attributes to dissipate energy as heat in response to changes in temperature and diet. Infrared thermography (IRT) has been studied in recent years in the assessment of BAT thermogenesis, as an option to positron emission tomography - computed tomography (PET-CT), because of several advantages. We performed a systematic review on the use of IRT in BAT assessment. Comprehensive online search was performed in different databases. The QUADAS 2 tool was used to evaluate studies' quality. 12 studies fit the inclusion criteria, whereas only one of these was considered of low risk of bias. 10 studies were favorable to IRT appliance in BAT evaluation, observing elevation of supraclavicular skin temperature correlated with BAT activity. Studies were heterogeneous in design, and a meta-analysis was precluded. Further studies with similar methodologies are needed. Conclusion: Despite the large number of published methodologies, IRT is a promising method for detecting BAT activation. Current knowledge already allows a better understanding of thermography to improve and standardize the technique.
Collapse
Affiliation(s)
- Sérgio Brasil
- Division of Neurological Surgery. Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil.
| | - Alessandra C Renck
- Department of Endocrinology, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Franciele de Meneck
- Department of Nephrology, School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Marcos L Brioschi
- Division of Neurological Surgery. Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Elaine F Costa
- Department of Endocrinology, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Manoel J Teixeira
- Division of Neurological Surgery. Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| |
Collapse
|
6
|
Hamaoka T, Nirengi S, Fuse S, Amagasa S, Kime R, Kuroiwa M, Endo T, Sakane N, Matsushita M, Saito M, Yoneshiro T, Kurosawa Y. Near-Infrared Time-Resolved Spectroscopy for Assessing Brown Adipose Tissue Density in Humans: A Review. Front Endocrinol (Lausanne) 2020; 11:261. [PMID: 32508746 PMCID: PMC7249345 DOI: 10.3389/fendo.2020.00261] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 04/08/2020] [Indexed: 01/24/2023] Open
Abstract
Brown adipose tissue (BAT) mediates adaptive thermogenesis upon food intake and cold exposure, thus potentially contributing to the prevention of lifestyle-related diseases. 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) with computed tomography (CT) (18FDG-PET/CT) is a standard method for assessing BAT activity and volume in humans. 18FDG-PET/CT has several limitations, including high device cost and ionizing radiation and acute cold exposure necessary to maximally stimulate BAT activity. In contrast, near-infrared spectroscopy (NIRS) has been used for measuring changes in O2-dependent light absorption in the tissue in a non-invasive manner, without using radiation. Among NIRS, time-resolved NIRS (NIRTRS) can quantify the concentrations of oxygenated and deoxygenated hemoglobin ([oxy-Hb] and [deoxy-Hb], respectively) by emitting ultrashort (100 ps) light pulses and counts photons, which are scattered and absorbed in the tissue. The basis for assessing BAT density (BAT-d) using NIRTRS is that the vascular density in the supraclavicular region, as estimated using Hb concentration, is higher in BAT than in white adipose tissue. In contrast, relatively low-cost continuous wavelength NIRS (NIRCWS) is employed for measuring relative changes in oxygenation in tissues. In this review, we provide evidence for the validity of NIRTRS and NIRCWS in estimating human BAT characteristics. The indicators (IndNIRS) examined were [oxy-Hb]sup, [deoxy-Hb]sup, total hemoglobin [total-Hb]sup, Hb O2 saturation (StO2sup), and reduced scattering coefficient ( μs sup' ) in the supraclavicular region, as determined by NIRTRS, and relative changes in corresponding parameters, as determined by NIRCWS. The evidence comprises the relationships between the IndNIRS investigated and those determined by 18FDG-PET/CT; the correlation between the IndNIRS and cold-induced thermogenesis; the relationship of the IndNIRS to parameters measured by 18FDG-PET/CT, which responded to seasonal temperature fluctuations; the relationship of the IndNIRS and plasma lipid metabolites; the analogy of the IndNIRS to chronological and anthropometric data; and changes in the IndNIRS following thermogenic food supplementation. The [total-Hb]sup and [oxy-Hb]sup determined by NIRTRS, but not parameters determined by NIRCWS, exhibited significant correlations with cold-induced thermogenesis parameters and plasma androgens in men in winter or analogies to 18FDG-PET. We conclude that NIRTRS can provide useful information for assessing BAT-d in a simple, rapid, non-invasive way, although further validation study is still needed.
Collapse
Affiliation(s)
- Takafumi Hamaoka
- Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo, Japan
- *Correspondence: Takafumi Hamaoka
| | - Shinsuke Nirengi
- Division of Preventive Medicine, National Hospital Organization Kyoto Medical Center, Clinical Research Institute, Kyoto, Japan
- Dorothy M. Davis Heart and Lung Research Institute, Wexner Medical Center, Columbus, OH, United States
| | - Sayuri Fuse
- Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo, Japan
| | - Shiho Amagasa
- Department of Preventive Medicine and Public Health, Tokyo Medical University, Tokyo, Japan
| | - Ryotaro Kime
- Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo, Japan
| | - Miyuki Kuroiwa
- Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo, Japan
| | - Tasuki Endo
- Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo, Japan
| | - Naoki Sakane
- Division of Preventive Medicine, National Hospital Organization Kyoto Medical Center, Clinical Research Institute, Kyoto, Japan
| | | | - Masayuki Saito
- Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Takeshi Yoneshiro
- Diabetes Center, University of California San Francisco, San Francisco, CA, United States
| | - Yuko Kurosawa
- Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo, Japan
| |
Collapse
|
7
|
Nirengi S, Fuse S, Amagasa S, Homma T, Kime R, Kuroiwa M, Endo T, Sakane N, Matsushita M, Saito M, Kurosawa Y, Hamaoka T. Applicability of Supraclavicular Oxygenated and Total Hemoglobin Evaluated by Near-Infrared Time-Resolved Spectroscopy as Indicators of Brown Adipose Tissue Density in Humans. Int J Mol Sci 2019; 20:ijms20092214. [PMID: 31064052 PMCID: PMC6539985 DOI: 10.3390/ijms20092214] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 04/26/2019] [Accepted: 05/04/2019] [Indexed: 01/13/2023] Open
Abstract
Brown adipose tissue (BAT) may potentially be used in strategies for preventing lifestyle-related diseases. We examine evidence that near-infrared time-resolved spectroscopy (NIRTRS) is capable of estimating human BAT density (BAT-d). The parameters examined in this study are total hemoglobin [total-Hb]sup, oxygenated Hb [oxy-Hb]sup, deoxygenated Hb [deoxy-Hb]sup, Hb O2 saturation (StO2sup), and the reduced scattering coefficient in the supraclavicular region (μs’sup), where BAT deposits can be located; corresponding parameters in the control deltoid region are obtained as controls. Among the NIRTRS parameters, [total-Hb]sup and [oxy-Hb]sup show region-specific increases in winter, compared to summer. Further, [total-Hb]sup and [oxy-Hb]sup are correlated with cold-induced thermogenesis in the supraclavicular region. We conclude that NIRTRS-determined [total-Hb]sup and [oxy-Hb]sup are useful parameters for evaluating BAT-d in a simple, rapid, non-invasive manner.
Collapse
Affiliation(s)
- Shinsuke Nirengi
- Division of Preventive Medicine, National Hospital Organization Kyoto Medical Center, Clinical Research Institute, Kyoto 612-8555, Japan.
| | - Sayuri Fuse
- Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo 160-8402, Japan.
| | - Shiho Amagasa
- Department of Preventive Medicine and Public Health, Tokyo Medical University, Tokyo 160-8402, Japan.
| | - Toshiyuki Homma
- Faculty of Sports and Health Science, Daito Bunka University, Higashimatsuyama-shi, Saitama 355-8501, Japan.
| | - Ryotaro Kime
- Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo 160-8402, Japan.
| | - Miyuki Kuroiwa
- Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo 160-8402, Japan.
| | - Tasuki Endo
- Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo 160-8402, Japan.
| | - Naoki Sakane
- Division of Preventive Medicine, National Hospital Organization Kyoto Medical Center, Clinical Research Institute, Kyoto 612-8555, Japan.
| | - Mami Matsushita
- Department of Nutrition, Tenshi College, Sapporo 065-0013, Japan.
| | | | - Yuko Kurosawa
- Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo 160-8402, Japan.
| | - Takafumi Hamaoka
- Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo 160-8402, Japan.
| |
Collapse
|