1
|
Jussila A, Zhang B, Kirti S, Atit R. Tissue fibrosis associated depletion of lipid-filled cells. Exp Dermatol 2024; 33:e15054. [PMID: 38519432 PMCID: PMC10977660 DOI: 10.1111/exd.15054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 02/06/2024] [Accepted: 02/29/2024] [Indexed: 03/24/2024]
Abstract
Fibrosis is primarily described as the deposition of excessive extracellular matrix, but in many tissues it also involves a loss of lipid or lipid-filled cells. Lipid-filled cells are critical to tissue function and integrity in many tissues including the skin and lungs. Thus, loss or depletion of lipid-filled cells during fibrogenesis, has implications for tissue function. In some contexts, lipid-filled cells can impact ECM composition and stability, highlighting their importance in fibrotic transformation. Recent papers in fibrosis address this newly recognized fibrotic lipodystrophy phenomenon. Even in disparate tissues, common mechanisms are emerging to explain fibrotic lipodystrophy. These findings have implications for fibrosis in tissues composed of fibroblast and lipid-filled cell populations such as skin, lung, and liver. In this review, we will discuss the roles of lipid-containing cells, their reduction/loss during fibrotic transformation, and the mechanisms of that loss in the skin and lungs.
Collapse
Affiliation(s)
- Anna Jussila
- Department of Biology, College of Arts and Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Brian Zhang
- Department of Biology, College of Arts and Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Sakin Kirti
- Department of Biology, College of Arts and Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Radhika Atit
- Department of Biology, College of Arts and Sciences, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Dermatology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| |
Collapse
|
2
|
Li Y, Long J, Zhang Z, Yin W. Insights into the unique roles of dermal white adipose tissue (dWAT) in wound healing. Front Physiol 2024; 15:1346612. [PMID: 38465261 PMCID: PMC10920283 DOI: 10.3389/fphys.2024.1346612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 01/31/2024] [Indexed: 03/12/2024] Open
Abstract
Dermal white adipose tissue (dWAT) is a newly recognized layer of adipocytes within the reticular dermis of the skin. In many mammals, this layer is clearly separated by panniculus carnosus from subcutaneous adipose tissue (sWAT). While, they concentrated around the hair shaft and follicle, sebaceous gland, and arrector pili muscle, and forms a very specific cone geometry in human. Both the anatomy and the histology indicate that dWAT has distinct development and functions. Different from sWAT, the developmental origin of dWAT shares a common precursor with dermal fibroblasts during embryogenesis. Therefore, when skin injury happens and mature adipocytes in dWAT are exposed, they may undergo lipolysis and dedifferentiate into fibroblasts to participate in wound healing as embryogenetic stage. Studies using genetic strategies to selectively ablate dermal adipocytes observed delayed revascularization and re-epithelialization in wound healing. This review specifically summarizes the hypotheses of the functions of dWAT in wound healing. First, lipolysis of dermal adipocytes could contribute to wound healing by regulating inflammatory macrophage infiltration. Second, loss of dermal adipocytes occurs at the wound edge, and adipocyte-derived cells then become ECM-producing wound bed myofibroblasts during the proliferative phase of repair. Third, mature dermal adipocytes are rich resources for adipokines and cytokines and could release them in response to injury. In addition, the dedifferentiated dermal adipocytes are more sensitive to redifferentiation protocol and could undergo expansion in infected wound. We then briefly introduce the roles of dWAT in protecting the skin from environmental challenges: production of an antimicrobial peptide against infection. In the future, we believe there may be great potential for research in these areas: (1) taking advantage of the plasticity of dermal adipocytes and manipulating them in wound healing; (2) investigating the precise mechanism of dWAT expansion in infected wound healing.
Collapse
Affiliation(s)
| | | | | | - Wen Yin
- *Correspondence: Ziang Zhang, ; Wen Yin,
| |
Collapse
|
3
|
Valenzuela PL, Carrera-Bastos P, Castillo-García A, Lieberman DE, Santos-Lozano A, Lucia A. Obesity and the risk of cardiometabolic diseases. Nat Rev Cardiol 2023; 20:475-494. [PMID: 36927772 DOI: 10.1038/s41569-023-00847-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 59.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/08/2023] [Indexed: 03/18/2023]
Abstract
The prevalence of obesity has reached pandemic proportions, and now approximately 25% of adults in Westernized countries have obesity. Recognized as a major health concern, obesity is associated with multiple comorbidities, particularly cardiometabolic disorders. In this Review, we present obesity as an evolutionarily novel condition, summarize the epidemiological evidence on its detrimental cardiometabolic consequences and discuss the major mechanisms involved in the association between obesity and the risk of cardiometabolic diseases. We also examine the role of potential moderators of this association, with evidence for and against the so-called 'metabolically healthy obesity phenotype', the 'fatness but fitness' paradox or the 'obesity paradox'. Although maintenance of optimal cardiometabolic status should be a primary goal in individuals with obesity, losing body weight and, particularly, excess visceral adiposity seems to be necessary to minimize the risk of cardiometabolic diseases.
Collapse
Affiliation(s)
- Pedro L Valenzuela
- Physical Activity and Health Research Group (PaHerg), Research Institute of Hospital 12 de Octubre ("i + 12"), Madrid, Spain.
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Spain.
| | - Pedro Carrera-Bastos
- Center for Primary Health Care Research, Department of Clinical Sciences, Lund University, Malmö, Sweden
- Faculty of Sport Sciences, Universidad Europea de Madrid, Madrid, Spain
| | | | - Daniel E Lieberman
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Alejandro Santos-Lozano
- Physical Activity and Health Research Group (PaHerg), Research Institute of Hospital 12 de Octubre ("i + 12"), Madrid, Spain
- Department of Health Sciences, European University Miguel de Cervantes, Valladolid, Spain
| | - Alejandro Lucia
- Faculty of Sport Sciences, Universidad Europea de Madrid, Madrid, Spain.
- CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain.
| |
Collapse
|
4
|
Kruglikov IL, Scherer PE. Pathophysiology of cellulite: Possible involvement of selective endotoxemia. Obes Rev 2023; 24:e13517. [PMID: 36285892 PMCID: PMC9772045 DOI: 10.1111/obr.13517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 09/13/2022] [Accepted: 10/02/2022] [Indexed: 12/27/2022]
Abstract
The most relevant hallmarks of cellulite include a massive protrusion of superficial adipose tissue into the dermis, reduced expression of the extracellular glycoprotein fibulin-3, and an unusually high presence of MUSE cells in gluteofemoral white adipose tissue (gfWAT) that displays cellulite. Also typical for this condition is the hypertrophic nature of the underlying adipose tissue, the interaction of adipocytes with sweat glands, and dysfunctional lymph and blood circulation as well as a low-grade inflammation in the areas of gfWAT affected by cellulite. Here, we propose a new pathophysiology of cellulite, which connects this skin condition with selective accumulation of endogenous lipopolysaccharides (LPS) in gfWAT. The accumulation of LPS within a specific WAT depot has so far not been considered as a possible pathophysiological mechanism triggering localized WAT modifications, but may very well be involved in conditions such as cellulite and, secondary to that, lipedema.
Collapse
Affiliation(s)
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-8549, USA
| |
Collapse
|
5
|
Sun C, Zhu H, Wang Y, Han Y, Zhang D, Cao X, Alip M, Nie M, Xu X, Lv L, Feng X, Sun L, Wang D. Serum metabolite differences detected by HILIC UHPLC-Q-TOF MS in systemic sclerosis. Clin Rheumatol 2023; 42:125-134. [PMID: 36127550 DOI: 10.1007/s10067-022-06372-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 09/01/2022] [Accepted: 09/03/2022] [Indexed: 01/11/2023]
Abstract
BACKGROUND Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by extensive fibrosis and vascular damage. Vasculopathy, activation of the immune system, and diffuse fibrosis are all involved in the fatal pathogenesis of SSc. However, little metabolomic research has been conducted in SSc. METHODS This study included 30 SSc patients and 30 healthy individuals. The metabolite differences in serum samples were analyzed using ultra-high-pressure liquid chromatography and quadrupole-time-of-flight mass spectrometry. Meanwhile, serum metabolites were analyzed in patients with systemic involvement (lung or skin fibrosis). RESULTS A total of 2360 ion peaks were detected, all of which were attributable to 38 metabolites. These metabolites primarily consisted of fatty acids, amino acids, and glycerophospholipids, which were the major metabolic pathways altered in SSc patients. Glutamine metabolism was the main pathway altered in SSc patients with lung involvement, whereas amino acid metabolism and steroid hormone biosynthesis were the main pathways altered in SSc patients with skin involvement. CONCLUSION These findings suggested that metabolic profiles and pathways differed between SSc patients and healthy people, potentially providing new targets for SSc-directed therapeutics and diagnostics. Key Points • Metabolic profiles and pathways differed between SSc patients and healthy people. • The levels of trans-dehydroandrosterone are substantially lower in lcSSc than in dcSSc, potentially providing new targets for SSc patients with skin involvement. • L-glutamine could be used as a serum metabolic marker and a therapeutic target for SSc patients with lung involvement.
Collapse
Affiliation(s)
- Chen Sun
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Huimin Zhu
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Yun Wang
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Yichen Han
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Dongdong Zhang
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Xi Cao
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Mihribangvl Alip
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Min Nie
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Xue Xu
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Liangjing Lv
- Department of Rheumatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Xuebing Feng
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China.
| | - Lingyun Sun
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China.
| | - Dandan Wang
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China.
| |
Collapse
|
6
|
Ahmed BA, Varah N, Ong FJ, Blondin DP, Gunn E, Konyer NB, Singh NP, Noseworthy MD, Haman F, Carpentier AC, Punthakee Z, Steinberg GR, Morrison KM. Impaired Cold-Stimulated Supraclavicular Brown Adipose Tissue Activity in Young Boys With Obesity. Diabetes 2022; 71:1193-1204. [PMID: 35293989 DOI: 10.2337/db21-0799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 02/28/2022] [Indexed: 11/13/2022]
Abstract
Childhood obesity is a growing worldwide problem. In adults, lower cold-induced brown adipose tissue (BAT) activity is linked to obesity and metabolic dysfunction; this relationship remains uncertain in children. In this cross-sectional study, we compared cold-induced supraclavicular (SCV) BAT activity (percent change in proton density fat fraction [PDFF]) within the SCV region after 1 h of whole-body cold exposure (18°C), using MRI in 26 boys aged 8-10 years: 13 with normal BMI and 13 with overweight/obesity. Anthropometry, body composition, hepatic fat, visceral adipose tissue (VAT), and pre- and postcold PDFF of the subcutaneous adipose tissue (SAT) in the posterior neck region and the abdomen were measured. Boys with overweight/obesity had lower cold-induced percent decline in SCV PDFF compared with those with normal BMI (1.6 ± 0.8 vs. 4.7 ± 1.2%, P = 0.044). SCV PDFF declined significantly in boys with normal BMI (2.7 ± 0.7%, P = 0.003) but not in boys with overweight/obesity (1.1 ± 0.5%, P = 0.053). No cold-induced changes in the PDFF of either neck SAT (-0.89 ± 0.7%, P = 0.250, vs. 0.37 ± 0.3%, P = 0.230) or abdominal SAT (-0.39 ± 0.5%, P = 0.409, and 0.25 ± 0.2%, P = 0.139, for normal BMI and overweight/obesity groups, respectively) were seen. The cold-induced percent decline in SCV PDFF was inversely related to BMI (r = -0.39, P = 0.047), waist circumference (r = -0.48, P = 0.014), and VAT (r = -0.47, P = 0.014). Thus, in young boys, as in adults, BAT activity is lower in those with overweight/obesity, suggesting that restoring activity may be important for improving metabolic health.
Collapse
Affiliation(s)
- Basma A Ahmed
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Nina Varah
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Frank J Ong
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Denis P Blondin
- Division of Neurology, Department of Medicine, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Elizabeth Gunn
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Norman B Konyer
- Imaging Research Centre, St. Joseph's Healthcare Hamilton, Hamilton, Ontario, Canada
| | - Nina P Singh
- Department of Radiology, McMaster University, Hamilton, Ontario, Canada
| | - Michael D Noseworthy
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Imaging Research Centre, St. Joseph's Healthcare Hamilton, Hamilton, Ontario, Canada
- Department of Radiology, McMaster University, Hamilton, Ontario, Canada
- Department of Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada
- School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Francois Haman
- Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Andre C Carpentier
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Zubin Punthakee
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Gregory R Steinberg
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Katherine M Morrison
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| |
Collapse
|
7
|
Phenotypical Conversions of Dermal Adipocytes as Pathophysiological Steps in Inflammatory Cutaneous Disorders. Int J Mol Sci 2022; 23:ijms23073828. [PMID: 35409189 PMCID: PMC8998946 DOI: 10.3390/ijms23073828] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 03/24/2022] [Accepted: 03/25/2022] [Indexed: 02/01/2023] Open
Abstract
Adipocytes from the superficial layer of subcutaneous adipose tissue undergo cyclic de- and re-differentiation, which can significantly influence the development of skin inflammation under different cutaneous conditions. This inflammation can be connected with local loading of the reticular dermis with lipids released due to de-differentiation of adipocytes during the catagen phase of the hair follicle cycle. Alternatively, the inflammation parallels a widespread release of cathelicidin, which typically takes place in the anagen phase (especially in the presence of pathogens). Additionally, trans-differentiation of dermal adipocytes into myofibroblasts, which can occur under some pathological conditions, can be responsible for the development of collateral scarring in acne. Here, we provide an overview of such cellular conversions in the skin and discuss their possible involvement in the pathophysiology of inflammatory skin conditions, such as acne and psoriasis.
Collapse
|
8
|
Chen L, You Q, Liu M, Li S, Wu Z, Hu J, Ma Y, Xia L, Zhou Y, Xu N, Zhang S. Remodeling of dermal adipose tissue alleviates cutaneous toxicity induced by anti-EGFR therapy. eLife 2022; 11:72443. [PMID: 35324426 PMCID: PMC8947768 DOI: 10.7554/elife.72443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 03/14/2022] [Indexed: 12/12/2022] Open
Abstract
Anti-epidermal growth factor receptor (EGFR) therapy–associated cutaneous toxicity is a syndrome characterized by papulopustular rash, local inflammation, folliculitis, and microbial infection, resulting in a decrease in quality of life and dose interruption. However, no effective clinical intervention is available for this adverse effect. Here, we report the atrophy of dermal white adipose tissue (dWAT), a highly plastic adipose tissue with various skin-specific functions, correlates with rash occurrence and exacerbation in a murine model of EGFR inhibitor-induced rash. The reduction in dWAT is due to the inhibition of adipogenic differentiation by defects in peroxisome proliferator-activated receptor γ (PPARγ) signaling, and increased lipolysis by the induced expression of the lipolytic cytokine IL6. The activation of PPARγ by rosiglitazone maintains adipogenic differentiation and represses the transcription of IL6, eventually improving skin functions and ameliorating the severity of rash without altering the antitumor effects. Thus, activation of PPARγ represents a promising approach to ameliorate cutaneous toxicity in patients with cancer who receive anti-EGFR therapy.
Collapse
Affiliation(s)
- Leying Chen
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Qing You
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Min Liu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Shuaihu Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Zhaoyu Wu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Jiajun Hu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yurui Ma
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Liangyong Xia
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Ying Zhou
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Nan Xu
- Department of Dermatology, Shanghai East Hospital, Tongji University, Shanghai, China
| | - Shiyi Zhang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
9
|
Kasza I, Kühn JP, Völzke H, Hernando D, Xu YG, Siebert JW, Gibson ALF, Yen CLE, Nelson DW, MacDougald OA, Richardson NE, Lamming DW, Kern PA, Alexander CM. Contrasting recruitment of skin-associated adipose depots during cold challenge of mouse and human. J Physiol 2022; 600:847-868. [PMID: 33724479 PMCID: PMC8443702 DOI: 10.1113/jp280922] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 03/02/2021] [Indexed: 02/03/2023] Open
Abstract
KEY POINTS Several distinct strategies produce and conserve heat to maintain the body temperature of mammals, each associated with unique physiologies, with consequences for wellness and disease susceptibility Highly regulated properties of skin offset the total requirement for heat production We hypothesize that the adipose component of skin is primarily responsible for modulating heat flux; here we evaluate the relative regulation of adipose depots in mouse and human, to test their recruitment to heat production and conservation We found that insulating mouse dermal white adipose tissue accumulates in response to environmentally and genetically induced cool stress; this layer is one of two adipose depots closely apposed to mouse skin, where the subcutaneous mammary gland fat pads are actively recruited to heat production In contrast, the body-wide adipose depot associated with human skin produces heat directly, potentially creating an alternative to the centrally regulated brown adipose tissue ABSTRACT: Mammalian skin impacts metabolic efficiency system-wide, controlling the rate of heat loss and consequent heat production. Here we compare the unique fat depots associated with mouse and human skin, to determine whether they have corresponding functions and regulation. For humans, we assay a skin-associated fat (SAF) body-wide depot to distinguish it from the subcutaneous fat pads characteristic of the abdomen and upper limbs. We show that the thickness of SAF is not related to general adiposity; it is much thicker (1.6-fold) in women than men, and highly subject-specific. We used molecular and cellular assays of β-adrenergic-induced lipolysis and found that dermal white adipose tissue (dWAT) in mice is resistant to lipolysis; in contrast, the body-wide human SAF depot becomes lipolytic, generating heat in response to β-adrenergic stimulation. In mice challenged to make more heat to maintain body temperature (either environmentally or genetically), there is a compensatory increase in thickness of dWAT: a corresponding β-adrenergic stimulation of human skin adipose (in vivo or in explant) depletes adipocyte lipid content. We summarize the regulation of skin-associated adipocytes by age, sex and adiposity, for both species. We conclude that the body-wide dWAT depot of mice shows unique regulation that enables it to be deployed for heat preservation; combined with the actively lipolytic subcutaneous mammary fat pads they enable thermal defence. The adipose tissue that covers human subjects produces heat directly, providing an alternative to the brown adipose tissues.
Collapse
Affiliation(s)
- Ildiko Kasza
- McArdle Laboratory for Cancer Research, University of
Wisconsin-Madison, Germany
| | - Jens-Peter Kühn
- Institute and Policlinic of Diagnostic and Interventional
Radiology, Medical Faculty Carl Gustav Carus, Technical University Dresden,
Germany
| | - Henry Völzke
- Institute of Community Medicine, University of Greifswald,
Germany
| | - Diego Hernando
- Department of Radiology, University of Wisconsin-School of
Medicine and Public Health,Department of Medical Physics, University of
Wisconsin-School of Medicine and Public Health
| | - Yaohui G. Xu
- Department of Dermatology, University of Wisconsin-School
of Medicine and Public Health
| | - John W. Siebert
- Department of Surgery, University of Wisconsin-School of
Medicine and Public Health
| | - Angela LF Gibson
- Department of Surgery, University of Wisconsin-School of
Medicine and Public Health
| | - C.-L. Eric Yen
- Department of Nutritional Sciences, University of
Wisconsin-Madison
| | - David W. Nelson
- Department of Nutritional Sciences, University of
Wisconsin-Madison
| | | | - Nicole E. Richardson
- Department of Medicine, University of Wisconsin-School of
Medicine and Public Health,William S. Middleton Memorial Veterans Hospital, Madison,
Wisconsin
| | - Dudley W. Lamming
- Department of Medicine, University of Wisconsin-School of
Medicine and Public Health,William S. Middleton Memorial Veterans Hospital, Madison,
Wisconsin
| | - Philip A. Kern
- Department of Internal Medicine, University of Kentucky,
Lexington
| | - CM Alexander
- McArdle Laboratory for Cancer Research, University of
Wisconsin-Madison, Germany,corresponding author: CM Alexander, McArdle
Laboratory for Cancer Research, University of Wisconsin-Madison, 1111 Highland
Ave, Madison WI 53705-2275. Ph: 608-265 5182;
| |
Collapse
|
10
|
Laber S, Forcisi S, Bentley L, Petzold J, Moritz F, Smirnov KS, Al Sadat L, Williamson I, Strobel S, Agnew T, Sengupta S, Nicol T, Grallert H, Heier M, Honecker J, Mianne J, Teboul L, Dumbell R, Long H, Simon M, Lindgren C, Bickmore WA, Hauner H, Schmitt-Kopplin P, Claussnitzer M, Cox RD. Linking the FTO obesity rs1421085 variant circuitry to cellular, metabolic, and organismal phenotypes in vivo. SCIENCE ADVANCES 2021; 7:eabg0108. [PMID: 34290091 PMCID: PMC8294759 DOI: 10.1126/sciadv.abg0108] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 06/04/2021] [Indexed: 05/09/2023]
Abstract
Variants in FTO have the strongest association with obesity; however, it is still unclear how those noncoding variants mechanistically affect whole-body physiology. We engineered a deletion of the rs1421085 conserved cis-regulatory module (CRM) in mice and confirmed in vivo that the CRM modulates Irx3 and Irx5 gene expression and mitochondrial function in adipocytes. The CRM affects molecular and cellular phenotypes in an adipose depot-dependent manner and affects organismal phenotypes that are relevant for obesity, including decreased high-fat diet-induced weight gain, decreased whole-body fat mass, and decreased skin fat thickness. Last, we connected the CRM to a genetically determined effect on steroid patterns in males that was dependent on nutritional challenge and conserved across mice and humans. Together, our data establish cross-species conservation of the rs1421085 regulatory circuitry at the molecular, cellular, metabolic, and organismal level, revealing previously unknown contextual dependence of the variant's action.
Collapse
Affiliation(s)
- Samantha Laber
- Mammalian Genetics Unit, MRC Harwell Institute, Oxfordshire OX11 0RD, UK.
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford OX3 7FZ, UK
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Sara Forcisi
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, Neuherberg, Germany.
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Liz Bentley
- Mammalian Genetics Unit, MRC Harwell Institute, Oxfordshire OX11 0RD, UK
| | - Julia Petzold
- Institute of Nutritional Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Franco Moritz
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, Neuherberg, Germany
| | - Kirill S Smirnov
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, Neuherberg, Germany
| | - Loubna Al Sadat
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Else Kröner-Fresenius-Centre for Nutritional Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Iain Williamson
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh, UK
| | - Sophie Strobel
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Institute of Nutritional Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Thomas Agnew
- Mammalian Genetics Unit, MRC Harwell Institute, Oxfordshire OX11 0RD, UK
| | - Shahana Sengupta
- Mammalian Genetics Unit, MRC Harwell Institute, Oxfordshire OX11 0RD, UK
| | - Tom Nicol
- Mammalian Genetics Unit, MRC Harwell Institute, Oxfordshire OX11 0RD, UK
| | - Harald Grallert
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Research Unit of Molecular Epidemiology, Institute of Epidemiology, Helmholtz Center Munich, Germany
| | - Margit Heier
- KORA Study Center Augsburg, University Hospital of Augsburg, Augsburg, Germany
- Institute of Epidemiology, Helmholtz Zentrum München, Munich, Germany
| | - Julius Honecker
- Else Kröner-Fresenius-Centre for Nutritional Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Joffrey Mianne
- Mary Lyon Centre, MRC Harwell Institute, Oxfordshire, UK
| | - Lydia Teboul
- Mary Lyon Centre, MRC Harwell Institute, Oxfordshire, UK
| | - Rebecca Dumbell
- Mammalian Genetics Unit, MRC Harwell Institute, Oxfordshire OX11 0RD, UK
| | - Helen Long
- Mammalian Genetics Unit, MRC Harwell Institute, Oxfordshire OX11 0RD, UK
- Nuffield Department of Medicine, University of Oxford, Henry Wellcome Building for Molecular Physiology, Old Road Campus, Headington, Oxford OX3 7BN, UK
| | - Michelle Simon
- Mammalian Genetics Unit, MRC Harwell Institute, Oxfordshire OX11 0RD, UK
| | - Cecilia Lindgren
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford OX3 7FZ, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
- Program in Medical and Population Genetics, Broad Institute, Cambridge, MA 02142, USA
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Wendy A Bickmore
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh, UK
| | - Hans Hauner
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute of Nutritional Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- Else Kröner-Fresenius-Centre for Nutritional Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Philippe Schmitt-Kopplin
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Analytical Food Chemistry, Technical University of Munich, Freising, Germany
| | - Melina Claussnitzer
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Institute for Aging Research, Hebrew SeniorLife and Harvard Medical School, Boston, MA, USA
| | - Roger D Cox
- Mammalian Genetics Unit, MRC Harwell Institute, Oxfordshire OX11 0RD, UK.
| |
Collapse
|
11
|
Von Bank H, Kirsh C, Simcox J. Aging adipose: Depot location dictates age-associated expansion and dysfunction. Ageing Res Rev 2021; 67:101259. [PMID: 33515751 PMCID: PMC8379680 DOI: 10.1016/j.arr.2021.101259] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 12/09/2020] [Accepted: 01/18/2021] [Indexed: 02/08/2023]
Abstract
Adipose tissue has a variety of diverse functions that maintain energy homeostasis. In conditions of excess energy availability, adipose tissue increases its lipid storage and communicates the nutritional abundance to various organs in the body. In conditions of energy depletion, such as fasting, cold exposure, or prolonged exercise, triglycerides stored in adipose tissue are released as free fatty acids to support the shift to catabolic metabolism. These diverse functions of storage, communication, and energy homeostasis are shared between numerous adipose depots including subcutaneous, visceral, brown, beige, intramuscular, marrow, and dermal adipose tissue. As organisms age, the cellular composition of these depots shifts to facilitate increased inflammatory cell infiltration, decreased vasculature, and increased adipocyte quantity and lipid droplet size. The purpose of this review is to give a comprehensive overview of the molecular and cellular changes that occur in various aged adipose depots and discuss their impact on physiology. The molecular signature of aged adipose leads to higher prevalence of metabolic disease in aged populations including type 2 diabetes, cardiovascular disease, Alzheimer's disease, and certain types of cancer.
Collapse
Affiliation(s)
- Helaina Von Bank
- Department of Biochemistry, University of Wisconsin Madison, USA.
| | - Charlie Kirsh
- Department of Biochemistry, University of Wisconsin Madison, USA.
| | - Judith Simcox
- Department of Biochemistry, University of Wisconsin Madison, USA.
| |
Collapse
|
12
|
Chen W, Wang Q, Zhou B, Zhang L, Zhu H. Lipid Metabolism Profiles in Rheumatic Diseases. Front Pharmacol 2021; 12:643520. [PMID: 33897433 PMCID: PMC8064727 DOI: 10.3389/fphar.2021.643520] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/18/2021] [Indexed: 12/25/2022] Open
Abstract
Rheumatic diseases are a group of chronic autoimmune disorders that involve multiple organs or systems and have high mortality. The mechanisms of these diseases are still ill-defined, and targeted therapeutic strategies are still challenging for physicians. Recent research indicates that cell metabolism plays important roles in the pathogenesis of rheumatic diseases. In this review, we mainly focus on lipid metabolism profiles (dyslipidaemia, fatty acid metabolism) and mechanisms in rheumatic diseases and discuss potential clinical applications based on lipid metabolism profiles.
Collapse
Affiliation(s)
- Weilin Chen
- Department of Rheumatology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, China.,Provincial Clinical Research Center for Rheumatic and Immunologic Diseases, Xiangya Hospital, Changsha, China
| | - Qi Wang
- Department of Radiology, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Bin Zhou
- Department of Nephrology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Lihua Zhang
- Department of Rheumatology, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Honglin Zhu
- Department of Rheumatology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, China.,Provincial Clinical Research Center for Rheumatic and Immunologic Diseases, Xiangya Hospital, Changsha, China
| |
Collapse
|
13
|
Vejmělka F, Okrouhlík J, Lövy M, Šaffa G, Nevo E, Bennett NC, Šumbera R. Heat dissipation in subterranean rodents: the role of body region and social organisation. Sci Rep 2021; 11:2029. [PMID: 33479351 PMCID: PMC7820455 DOI: 10.1038/s41598-021-81404-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 12/30/2020] [Indexed: 01/29/2023] Open
Abstract
The relatively warm and very humid environment of burrows presents a challenge for thermoregulation of its mammalian inhabitants. It was found that African mole-rats dissipate body heat mainly through their venter, and social mole-rats dissipate more body heat compared to solitary species at lower temperatures. In addition, the pattern of the ventral surface temperature was suggested to be homogeneous in social mole-rats compared to a heterogeneous pattern in solitary mole-rats. To investigate this for subterranean rodents generally, we measured the surface temperatures of seven species with different degrees of sociality, phylogeny, and climate using infrared thermography. In all species, heat dissipation occurred mainly through the venter and the feet. Whereas the feet dissipated body heat at higher ambient temperatures and conserved it at lower ambient temperatures, the ventral surface temperature was relatively high in all temperatures indicating that heat dissipation to the environment through this body region is regulated mainly by behavioural means. Solitary species dissipated less heat through their dorsum than social species, and a tendency for this pattern was observed for the venter. The pattern of heterogeneity of surface temperature through the venter was not related to sociality of the various species. Our results demonstrate a general pattern of body heat exchange through the three studied body regions in subterranean rodents. Besides, isolated individuals of social species are less able to defend themselves against low ambient temperatures, which may handicap them if staying alone for a longer period, such as during and after dispersal events.
Collapse
Affiliation(s)
- František Vejmělka
- Department of Zoology, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic
| | - Jan Okrouhlík
- Department of Zoology, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, 0002, South Africa
| | - Matěj Lövy
- Department of Zoology, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic
| | - Gabriel Šaffa
- Department of Zoology, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic
| | - Eviatar Nevo
- Institute of Evolution, University of Haifa, 3498838, Haifa, Israel
| | - Nigel Charles Bennett
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, 0002, South Africa
| | - Radim Šumbera
- Department of Zoology, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic.
| |
Collapse
|
14
|
Walendzik K, Bukowska J, Kopcewicz M, Machcinska S, Gimble JM, Gawronska-Kozak B. Age, Diet and Epidermal Signaling Modulate Dermal Fibroblasts' Adipogenic Potential. Int J Mol Sci 2020; 21:ijms21238955. [PMID: 33255750 PMCID: PMC7728337 DOI: 10.3390/ijms21238955] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/16/2020] [Accepted: 11/23/2020] [Indexed: 12/14/2022] Open
Abstract
The recognition of a distinct fat depot, the dermal white adipose tissue (dWAT), points out the complexity of the interaction among skin resident cells: keratinocytes, dermal fibroblasts (DFs) and adipocytes in response to physiological (diet, age) and pathological (injury) stimulations. dWAT has been recognized as a significant contributor to thermoregulation, hair cycle, immune response, wound healing and scarring. In this study, we examined age- and diet-related changes in dWAT modulation and DFs' adipogenic potential. The data showed that diet modulates dWAT expansion predominantly by hypertrophy, whereas age affects the pool of adipocyte progenitor cells in the skin indicating its role in dWAT hyperplasia. Analysis of DFs' migratory abilities in the model of skin explants isolated from the skin of young, old, low (LFD)- or high (HFD)-fat diet C56BL/6 mice revealed that HFD, regardless of animal age has the most profound stimulatory impact of DF migration. We determined that the adipogenic potential of DFs is comparable to stromal vascular fraction (SVF) of inguinal fat depot and ear mesenchymal stem cells (EMSC). We also showed the stimulatory role of epidermally expressed transcription factor Foxn1 on adipogenic signaling: bone morphogenetic protein 2 (Bmp2) and insulin-like growth factor 2 (Igf2) in keratinocytes.
Collapse
Affiliation(s)
- Katarzyna Walendzik
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-748 Olsztyn, Poland; (K.W.); (J.B.); (M.K.); (S.M.)
| | - Joanna Bukowska
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-748 Olsztyn, Poland; (K.W.); (J.B.); (M.K.); (S.M.)
| | - Marta Kopcewicz
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-748 Olsztyn, Poland; (K.W.); (J.B.); (M.K.); (S.M.)
| | - Sylwia Machcinska
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-748 Olsztyn, Poland; (K.W.); (J.B.); (M.K.); (S.M.)
| | - Jeffrey M. Gimble
- LaCell LLC, New Orleans, LA 70112, USA;
- Obatala Sciences Inc., 2000 Lakeshore Drive, #4020, New Orleans, LA 70148, USA
- Departments of Medicine, Structural and Cellular Biology, and Surgery and Center for Stem Cell Research and Regenerative Medicine, Tulane University School of Medicine, New Orleans, LA 70118, USA
| | - Barbara Gawronska-Kozak
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-748 Olsztyn, Poland; (K.W.); (J.B.); (M.K.); (S.M.)
- Correspondence: ; Tel.: +48-89-5234634; Fax: +48-89-5240124
| |
Collapse
|
15
|
Zhang Z, Shao M, Hepler C, Zi Z, Zhao S, An YA, Zhu Y, Ghaben AL, Wang MY, Li N, Onodera T, Joffin N, Crewe C, Zhu Q, Vishvanath L, Kumar A, Xing C, Wang QA, Gautron L, Deng Y, Gordillo R, Kruglikov I, Kusminski CM, Gupta RK, Scherer PE. Dermal adipose tissue has high plasticity and undergoes reversible dedifferentiation in mice. J Clin Invest 2020; 129:5327-5342. [PMID: 31503545 DOI: 10.1172/jci130239] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/29/2019] [Indexed: 12/19/2022] Open
Abstract
Dermal adipose tissue (also known as dermal white adipose tissue and herein referred to as dWAT) has been the focus of much discussion in recent years. However, dWAT remains poorly characterized. The fate of the mature dermal adipocytes and the origin of the rapidly reappearing dermal adipocytes at different stages remain unclear. Here, we isolated dermal adipocytes and characterized dermal fat at the cellular and molecular level. Together with dWAT's dynamic responses to external stimuli, we established that dermal adipocytes are a distinct class of white adipocytes with high plasticity. By combining pulse-chase lineage tracing and single-cell RNA sequencing, we observed that mature dermal adipocytes undergo dedifferentiation and redifferentiation under physiological and pathophysiological conditions. Upon various challenges, the dedifferentiated cells proliferate and redifferentiate into adipocytes. In addition, manipulation of dWAT highlighted an important role for mature dermal adipocytes for hair cycling and wound healing. Altogether, these observations unravel a surprising plasticity of dermal adipocytes and provide an explanation for the dynamic changes in dWAT mass that occur under physiological and pathophysiological conditions, and highlight the important contributions of dWAT toward maintaining skin homeostasis.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Yi Zhu
- Touchstone Diabetes Center
| | | | | | - Na Li
- Touchstone Diabetes Center
| | | | | | | | | | | | - Ashwani Kumar
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Chao Xing
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Qiong A Wang
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute, City of Hope/Beckman Research Institute, Duarte, California, USA
| | - Laurent Gautron
- Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | | | | | - Ilja Kruglikov
- Scientific Department, Wellcomet GmbH, Karlsruhe, Germany
| | | | | | | |
Collapse
|
16
|
Pleštilová L, Okrouhlík J, Burda H, Sehadová H, Valesky EM, Šumbera R. Functional histology of the skin in the subterranean African giant mole-rat: thermal windows are determined solely by pelage characteristics. PeerJ 2020; 8:e8883. [PMID: 32296606 PMCID: PMC7150539 DOI: 10.7717/peerj.8883] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 03/10/2020] [Indexed: 11/29/2022] Open
Abstract
Excavation of burrows is an extremely physically demanding activity producing a large amount of metabolic heat. Dissipation of its surplus is crucial to avoid the risk of overheating, but in subterranean mammals it is complicated due to the absence of notable body extremities and high humidity in their burrows. IR-thermography in a previous study on two species of African mole-rats revealed that body heat was dissipated mainly through the ventral body part, which is notably less furred. Here, we analyzed the dorsal and ventral skin morphology, to test if dermal characteristics could contribute to higher heat dissipation through the ventral body part. The thickness of the epidermis and dermis and the presence, extent and connectivity of fat tissue in the dermis were examined using routine histological methods, while vascular density was evaluated using fluorescent dye and confocal microscopy in the giant mole-rat Fukomys mechowii. As in other hitherto studied subterranean mammals, no subcutaneous adipose tissue was found. All examined skin characteristics were very similar for both dorsal and ventral regions: relative content of adipose tissue in the dermis (14.4 ± 3.7% dorsally and 11.0 ± 4.0% ventrally), connectivity of dermal fat (98.5 ± 2.8% and 95.5 ± 6.8%), vascular density (26.5 ± 3.3% and 22.7 ± 2.3%). Absence of large differences in measured characteristics between particular body regions indicates that the thermal windows are determined mainly by the pelage characteristics.
Collapse
Affiliation(s)
- Lucie Pleštilová
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Jan Okrouhlík
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Hynek Burda
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic
| | - Hana Sehadová
- Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
- Institute of Entomology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Eva M. Valesky
- Department of Dermatology, Venereology and Allergology, University Hospital, Johann Wolfgang Goethe Universität Frankfurt am Main, Frankfurt am Main, Germany
| | - Radim Šumbera
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| |
Collapse
|
17
|
Kasza I, Adler D, Nelson DW, Eric Yen CL, Dumas S, Ntambi JM, MacDougald OA, Hernando D, Porter WP, Best FA, Alexander CM. Evaporative cooling provides a major metabolic energy sink. Mol Metab 2019; 27:47-61. [PMID: 31302039 PMCID: PMC6717770 DOI: 10.1016/j.molmet.2019.06.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/08/2019] [Accepted: 06/27/2019] [Indexed: 11/30/2022] Open
Abstract
Objective Elimination of food calories as heat could help redress the excess accumulation of metabolic energy exhibited as obesity. Prior studies have focused on the induction of thermogenesis in beige and brown adipose tissues as the application of this principle, particularly because the β-adrenergic environment associated with thermogenic activation has been shown to have positive health implications. The counterpoint to this strategy is the regulation of heat loss; we propose that mammals with inefficient heat conservation will require more thermogenesis to maintain body temperature. Methods Surface temperature thermography and rates of trans-epidermal water loss were integrated to profile the total heat transfer of genetically-engineered and genetically variable mice. Results These data were incorporated with energy expenditure data to generate a biophysical profile to test the significance of increased rates of evaporative cooling. Conclusions We show that mouse skins vary considerably in their heat retention properties, whether because of naturally occurring variation (SKH-1 mice), or genetic modification of the heat-retaining lipid lamellae (SCD1, DGAT1 or Agouti Ay obese mice). In particular, we turn attention to widely different rates of evaporative cooling as the result of trans-epidermal water loss; higher rates of heat loss by evaporative cooling leads to increased demand for thermogenesis. We speculate that this physiology could be harnessed to create an energy sink to assist with strategies aimed at treating metabolic diseases.
Collapse
Affiliation(s)
- Ildiko Kasza
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, United States
| | - Doug Adler
- Space Science and Engineering Center, University of Wisconsin-Madison, United States
| | - David W Nelson
- Department of Nutritional Sciences, University of Wisconsin-Madison, United States
| | - C-L Eric Yen
- Department of Nutritional Sciences, University of Wisconsin-Madison, United States
| | - Sabrina Dumas
- Department of Nutritional Sciences, University of Wisconsin-Madison, United States
| | - James M Ntambi
- Department of Nutritional Sciences, University of Wisconsin-Madison, United States; Department of Biochemistry, University of Wisconsin-Madison, United States
| | - Ormond A MacDougald
- Department of Molecular and Integrative Physiology, University of Michigan, United States
| | - Diego Hernando
- Department of Radiology, University of Wisconsin-Madison, United States
| | - Warren P Porter
- Department of Zoology, University of Wisconsin-Madison, United States
| | - Fred A Best
- Space Science and Engineering Center, University of Wisconsin-Madison, United States
| | - C M Alexander
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, United States.
| |
Collapse
|
18
|
Zhu H, Chen W, Liu D, Luo H. The role of metabolism in the pathogenesis of systemic sclerosis. Metabolism 2019; 93:44-51. [PMID: 30586574 DOI: 10.1016/j.metabol.2018.12.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 12/09/2018] [Accepted: 12/14/2018] [Indexed: 12/31/2022]
Abstract
Systemic sclerosis (SSc) is an immune-mediated autoimmune disease characterized by fibrosis and vascular abnormalities. The cellular and molecular mechanisms remain unclear, and current therapies are limited. Cell metabolism has been shown to play an essential role in cancer survival and tumour invasion as well as in rheumatic diseases such as systemic lupus erythematosus, rheumatoid arthritis and osteoarthritis. Although little is known about SSc, cell metabolism may provide new clues for understanding its pathogenesis. In this review, we summarize recent studies of metabolism in SSc and fibrotic disease, specifically focusing on glycolysis, fatty acid metabolism and oxidative stress. We highlight the role of metabolism in fibroblast differentiation and emphasize its potential therapeutic prospects in SSc.
Collapse
Affiliation(s)
- Honglin Zhu
- Department of Rheumatology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Weilin Chen
- Department of Rheumatology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Di Liu
- Department of Rheumatology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Hui Luo
- Department of Rheumatology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China.
| |
Collapse
|
19
|
Nicu C, Pople J, Bonsell L, Bhogal R, Ansell DM, Paus R. A guide to studying human dermal adipocytes in situ. Exp Dermatol 2018; 27:589-602. [DOI: 10.1111/exd.13549] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Carina Nicu
- Centre for Dermatology Research; The University of Manchester; Manchester UK
- NIHR Manchester Biomedical Research Centre; Manchester Academic Health Science Centre; Manchester UK
| | | | - Laura Bonsell
- Centre for Dermatology Research; The University of Manchester; Manchester UK
- NIHR Manchester Biomedical Research Centre; Manchester Academic Health Science Centre; Manchester UK
| | | | - David M. Ansell
- Centre for Dermatology Research; The University of Manchester; Manchester UK
- NIHR Manchester Biomedical Research Centre; Manchester Academic Health Science Centre; Manchester UK
| | - Ralf Paus
- Centre for Dermatology Research; The University of Manchester; Manchester UK
- NIHR Manchester Biomedical Research Centre; Manchester Academic Health Science Centre; Manchester UK
- Department of Dermatology and Cutaneous Surgery; Miller School of Medicine; University of Miami; Miami FL USA
| |
Collapse
|
20
|
Varga J, Marangoni RG. Systemic sclerosis in 2016: Dermal white adipose tissue implicated in SSc pathogenesis. Nat Rev Rheumatol 2017; 13:71-72. [PMID: 28077865 DOI: 10.1038/nrrheum.2016.223] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- John Varga
- Division of Rheumatology and Northwestern Scleroderma Program, Northwestern University Feinberg School of Medicine, 240 East Huron Street, Chicago, Illinois 60657, USA
| | - Roberta G Marangoni
- Division of Rheumatology and Northwestern Scleroderma Program, Northwestern University Feinberg School of Medicine, 240 East Huron Street, Chicago, Illinois 60657, USA
| |
Collapse
|