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Asia Pacific Journal of Clinical... 2020Obesity is caused by excessive fat accumulation or abnormal fat distribution and has become one of the biggest health challenges worldwide. Considering the high... (Review)
Review
BACKGROUND AND OBJECTIVES
Obesity is caused by excessive fat accumulation or abnormal fat distribution and has become one of the biggest health challenges worldwide. Considering the high thermogenic ability of brown fat tissue (BAT) and the plasticity of fat tissue, to induce the browning of white fat tissue (WAT), so increasing BAT activity provides an attractive option for the prevention and resolution of obesity. The aim of the present narrative review was to understand the relationship between diet, BAT, and obesity.
METHODS AND STUDY DESIGN
PubMed and Embase databases were searched to identify eligible studies.
RESULTS
Although cold exposure has long been known to be effective in the browning of WAT and activation of BAT, it is societally impractical for everyday body weight management aside from the tolerance of ambient temperature. An alternative is to identify specific dietary components with similar effects to cold exposure on BAT. Current evidence indicates that capsaicin and capsinoids, catechins, curcumin, quercetin, berberine, lipoic acid, polyunsaturated fatty acids, royal jelly, and some natural sweeteners are effective promoters of WAT browning, increase BAT activity and improve obesity related traits. However, only capsaicin, capsinoids, and catechins have demonstrated efficacy in clinical trials. Evidence for effects of curcumin, quercetin, berberine, lipoic acid, polyunsaturated fatty acids, royal jelly and natural sweeteners on BAT have only been observed in animal or in vitro studies, with clinical trials awaited for verification.
CONCLUSIONS
Several dietary components can induce WAT browning and activate BAT, offering potential targets for obesity prevention and management.
Topics: Adipose Tissue, Beige; Adipose Tissue, Brown; Adipose Tissue, White; Animals; Obesity; Thermogenesis
PubMed: 33377360
DOI: 10.6133/apjcn.202012_29(4).0001 -
Disease Models & Mechanisms Sep 2012The main parenchymal cells of the adipose organ are adipocytes. White adipocytes store energy, whereas brown adipocytes dissipate energy for thermogenesis. These two... (Review)
Review
The main parenchymal cells of the adipose organ are adipocytes. White adipocytes store energy, whereas brown adipocytes dissipate energy for thermogenesis. These two cell types with opposing functions can both originate from endothelial cells, and co-exist in the multiple fat depots of the adipose organ - a feature that I propose is crucial for this organ's plasticity. This poster review provides an overview of the adipose organ, describing its anatomy, cytology, physiological function and histopathology in obesity. It also highlights the remarkable plasticity of the adipose organ, explaining theories of adipocyte transdifferentiation during chronic cold exposure, physical exercise or lactation, as well as in obesity. White-to-brown adipocyte transdifferentiation is of particular medical relevance, because animal data indicate that higher amounts of brown adipose tissue are positively associated with resistance to obesity and its co-morbidities, and that 'browning' of the adipose organ curbs these disorders.
Topics: Adipose Tissue; Adipose Tissue, Brown; Animals; Humans; Organ Specificity
PubMed: 22915020
DOI: 10.1242/dmm.009662 -
Journal of Lipid Research Jun 2007This review focuses on adipose tissue biology and introduces the concept of adipose tissue plasticity and expandability as key determinants of obesity-associated... (Review)
Review
This review focuses on adipose tissue biology and introduces the concept of adipose tissue plasticity and expandability as key determinants of obesity-associated metabolic dysregulation. This concept is fundamental to our understanding of adipose tissue as a dynamic organ at the center of nutritional adaptation. Here, we summarize the current knowledge of the mechanisms by which adipose tissue can affect peripheral energy homeostasis, particularly in the context of overnutrition. Two mechanisms emerge that provide a molecular understanding for obesity-associated insulin resistance. These are a) the dysregulation of adipose tissue expandability and b) the abnormal production of adipokines. This knowledge has the potential to pave the way for novel therapeutic concepts and strategies for managing and/or correcting complications associated with obesity and the metabolic syndrome.
Topics: Adipocytes; Adipose Tissue; Animals; Humans; Insulin Resistance; Lipid Metabolism; Models, Biological; Obesity
PubMed: 17374880
DOI: 10.1194/jlr.R700005-JLR200 -
Alimentary Pharmacology & Therapeutics Sep 2010The lymphatic system plays critical roles in tissue fluid homoeostasis, immune defence and metabolic maintenance. Lymphatic vessels transport lymph, proteins, immune... (Review)
Review
BACKGROUND
The lymphatic system plays critical roles in tissue fluid homoeostasis, immune defence and metabolic maintenance. Lymphatic vessels transport lymph, proteins, immune cells and digested lipids, allowing fluid and proteins to be returned to the blood stream, lipids to be stored and metabolized and antigens to be sampled in lymph nodes. Lymphatic drainage is mainly driven by rhythmic constrictions intrinsic to the vessels and critically modulated by fluid pressure and inflammatory mediators.
AIM
To collect and discuss the compelling available information linking the lymphatic system, adiposity and inflammation.
METHODS
A literature search was performed through PubMed focusing on lymphatic system, inflammation, immune cells and fat transport and function in the context of IBD.
RESULTS
Evidence collected allows us to propose the following working model. Compromised lymph drainage, reported in IBD, leads to oedema, lymphangiogenesis, impaired immune cell trafficking and lymph leakage. Lymph factor(s) stimulate adipose tissue to proliferate and produce cytokines, which affect immune cell functions and exacerbate inflammation.
CONCLUSIONS
Understanding the lymphatic system's role in immune cell trafficking and immune responses, contribution to fat transport, distribution, metabolism and implication in the pathogenesis of chronic intestinal inflammation may provide the basis for new therapeutic strategies and improved quality-of life.
Topics: Adipose Tissue; Humans; Inflammatory Bowel Diseases; Lymphatic System; Models, Biological
PubMed: 20636483
DOI: 10.1111/j.1365-2036.2010.04407.x -
Tissue Engineering. Part B, Reviews Aug 2010Current treatment modalities for soft tissue defects caused by various pathologies and trauma include autologous grafting and commercially available fillers. However,... (Review)
Review
Current treatment modalities for soft tissue defects caused by various pathologies and trauma include autologous grafting and commercially available fillers. However, these treatment methods present a number of challenges and limitations, such as donor-site morbidity and volume loss over time. As such, improved therapeutic modalities need to be developed. Tissue engineering techniques offer novel solutions to these problems through development of bioactive tissue constructs that can regenerate adipose tissue in both structure and function. Recently, a number of studies have been designed to explore various methods to engineer human adipose tissue. This review will focus on these developments in the area of adipose tissue engineering for soft tissue replacement. The physiology of adipose tissue and current surgical therapies used to replace lost tissue volume, specifically in breast tissue, are introduced, and current biomaterials, cell sources, and tissue culture strategies are discussed. We discuss future areas of study in adipose tissue engineering.
Topics: Adipose Tissue; Animals; Biocompatible Materials; Regeneration; Tissue Culture Techniques; Tissue Engineering
PubMed: 20166810
DOI: 10.1089/ten.TEB.2009.0544 -
JCI Insight Jun 2021BACKGROUNDAdipocytes were long considered inert components of the bone marrow niche, but mouse and human models suggest bone marrow adipose tissue (BMAT) is dynamic and...
BACKGROUNDAdipocytes were long considered inert components of the bone marrow niche, but mouse and human models suggest bone marrow adipose tissue (BMAT) is dynamic and responsive to hormonal and nutrient cues.METHODSIn this study of healthy volunteers, we investigated how BMAT responds to acute nutrient changes, including analyses of endocrine determinants and paracrine factors from marrow aspirates. Study participants underwent a 10-day high-calorie protocol, followed by a 10-day fast.RESULTSWe demonstrate (a) vertebral BMAT increased significantly during high-calorie feeding and fasting, suggesting BMAT may have different functions in states of caloric excess compared with caloric deprivation; (b) ghrelin, which decreased in response to high-calorie feeding and fasting, was inversely associated with changes in BMAT; and (c) in response to high-calorie feeding, resistin levels in the marrow sera, but not the circulation, rose significantly. In addition, TNF-α expression in marrow adipocytes increased with high-calorie feeding and decreased upon fasting.CONCLUSIONHigh-calorie feeding, but not fasting, induces an immune response in bone marrow similar to what has been reported in peripheral adipose tissue. Understanding the immunomodulatory regulators in the marrow may provide further insight into the homeostatic function of this unique adipose tissue depot.FUNDINGNIH grant R24 DK084970, Harvard Catalyst/The Harvard Clinical and Translational Science Center (National Center for Advancing Translational Sciences, NIH, award UL 1TR002541), and NIH grants P30 DK040561 and U19 AG060917S1.
Topics: Adipose Tissue; Adult; Bone Marrow; Fasting; Female; Humans; Male
PubMed: 33974568
DOI: 10.1172/jci.insight.138636 -
Annals of Biomedical Engineering Mar 2016Adipose tissue engineering is a diverse area of research where the developed tissues can be used to study normal adipose tissue functions, create disease models in... (Review)
Review
Adipose tissue engineering is a diverse area of research where the developed tissues can be used to study normal adipose tissue functions, create disease models in vitro, and replace soft tissue defects in vivo. Increasing attention has been focused on the highly specialized metabolic pathways that regulate energy storage and release in adipose tissues which affect local and systemic outcomes. Non-invasive, dynamic measurement systems are useful to track these metabolic pathways in the same tissue model over time to evaluate long term cell growth, differentiation, and development within tissue engineering constructs. This approach reduces costs and time in comparison to more traditional destructive methods such as biochemical and immunochemistry assays and proteomics assessments. Towards this goal, this review will focus on important metabolic functions of adipose tissues and strategies to evaluate them with non-invasive in vitro methods. Current non-invasive methods, such as measuring key metabolic markers and endogenous contrast imaging will be explored.
Topics: Adipose Tissue; Biomarkers; Cell Differentiation; Cell Movement; Energy Metabolism; Humans; Models, Biological; Tissue Engineering
PubMed: 26399988
DOI: 10.1007/s10439-015-1438-9 -
Cardiovascular Diabetology Oct 2018Perivascular adipose tissue (PVAT), the adipose tissue that surrounds most of the vasculature, has emerged as an active component of the blood vessel wall regulating... (Review)
Review
Perivascular adipose tissue (PVAT), the adipose tissue that surrounds most of the vasculature, has emerged as an active component of the blood vessel wall regulating vascular homeostasis and affecting the pathogenesis of atherosclerosis. Although PVAT characteristics resemble both brown and white adipose tissues, recent evidence suggests that PVAT develops from its own distinct precursors implying a closer link between PVAT and vascular system. Under physiological conditions, PVAT has potent anti-atherogenic properties mediated by its ability to secrete various biologically active factors that induce non-shivering thermogenesis and metabolize fatty acids. In contrast, under pathological conditions (mainly obesity), PVAT becomes dysfunctional, loses its thermogenic capacity and secretes pro-inflammatory adipokines that induce endothelial dysfunction and infiltration of inflammatory cells, promoting atherosclerosis development. Since PVAT plays crucial roles in regulating key steps of atherosclerosis development, it may constitute a novel therapeutic target for the prevention and treatment of atherosclerosis. Here, we review the current literature regarding the roles of PVAT in the pathogenesis of atherosclerosis.
Topics: Adipokines; Adipose Tissue; Adiposity; Animals; Anti-Inflammatory Agents; Atherosclerosis; Blood Vessels; Cardiovascular Agents; Energy Metabolism; Humans; Inflammation Mediators; Protective Factors; Risk Factors; Signal Transduction; Thermogenesis
PubMed: 30305178
DOI: 10.1186/s12933-018-0777-x -
Urology Journal Oct 2019To evaluate whether maternal body mass index (BMI), visceral adipose tissue (VAT) thickness, and sub-cutaneous adipose tissue (SAT) thickness have effects on maternal... (Observational Study)
Observational Study
PURPOSE
To evaluate whether maternal body mass index (BMI), visceral adipose tissue (VAT) thickness, and sub-cutaneous adipose tissue (SAT) thickness have effects on maternal pelvicalyceal system dilatation, which develops during pregnancy.
MATERIALS AND METHODS
Between April 2018 and November 2018, a total of 120 pregnant women aged between 18-35 years in their third trimester were included in this prospective observational study. For each pregnant wom-an, SAT and VAT thicknesses were measured and renal sonography was performed by the same radiologist and obstetric ultrasound was performed by the same obstetrician. Nine patients were excluded from the study because their maximal caliceal diameters were less than 5 mm. Ultimately, 111 patients were divided into three groups according to the maximal calyceal diameter (MCD).
RESULTS
Asymptomatic hydronephrosis was diagnosed in 108/111 (97.3%) of the patients. There were 53 patients in group 1 (MCD of 5-10 mm), 39 patients in group 2 (MCD of 10-15 mm), and 19 patients in group 3 (MCD of >15 mm). There were statistically significant differences in terms of maternal SAT and VAT thickness between the groups (P = .001). There were also statistically significant differences between the groups for the estimated fetal weight and birth weight (P = .024, P = .003, respectively). In the correlation analysis, there was a negative correlation between maternal SAT thickness, VAT thicknesses, BMI, and maximal calyceal diameter (P = .001).
CONCLUSION
In this study, relationships between maternal BMI, VAS thickness, SAT thickness, the estimated fetal weight, birth weight, and renal pelvicalyceal dilatation have been shown. Increasing maternal adipose tissue may have a protective effect of mechanical pressure of growing uterus on the ureters.
Topics: Adipose Tissue; Adolescent; Adult; Female; Humans; Kidney Pelvis; Pregnancy; Prospective Studies; Young Adult
PubMed: 31478185
DOI: 10.22037/uj.v0i0.5039 -
Cell Reports Jan 2024Severe burns induce a chronic hypermetabolic state that persists well past wound closure, indicating that additional internal mechanisms must be involved. Adipose tissue...
Severe burns induce a chronic hypermetabolic state that persists well past wound closure, indicating that additional internal mechanisms must be involved. Adipose tissue is suggested to be a central regulator in perpetuating hypermetabolism, although this has not been directly tested. Here, we show that thermogenic adipose tissues are activated in parallel to increases in hypermetabolism independent of cold stress. Using an adipose tissue transplantation model, we discover that burn-derived subcutaneous white adipose tissue alone is sufficient to invoke a hypermetabolic response in a healthy recipient mouse. Concomitantly, transplantation of healthy adipose tissue alleviates metabolic dysfunction in a burn recipient. We further show that the nicotinic acetylcholine receptor signaling pathway may mediate an immune-adipose crosstalk to regulate adipose tissue remodeling post-injury. Targeting this pathway could lead to innovative therapeutic interventions to counteract hypermetabolic pathologies.
Topics: Animals; Mice; Subcutaneous Fat; Adipose Tissue, White; Obesity; Energy Metabolism; Burns; Adipose Tissue, Brown; Adipose Tissue
PubMed: 38117653
DOI: 10.1016/j.celrep.2023.113584