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Frontiers in Endocrinology 2021Adipose tissue (AT) is classified based on its location, physiological and functional characteristics. Although there is a clear demarcation of anatomical and molecular... (Review)
Review
Adipose tissue (AT) is classified based on its location, physiological and functional characteristics. Although there is a clear demarcation of anatomical and molecular features specific to white (WAT) and brown adipose tissue (BAT), the factors that uniquely differentiate beige AT (BeAT) remain to be fully elaborated. The ubiquitous presence of different types of AT and the inability to differentiate brown and beige adipocytes because of similar appearance present a challenge when classifying them one way or another. Here we will provide an overview of the latest advances in BeAT, BAT, and WAT identification based on transcript markers described in the literature. The review paper will highlight some of the difficulties these markers pose and will offer new perspectives on possible transcript-specific identification of BeAT. We hope that this will advance the understanding of the biology of different ATs. In addition, concrete strategies to distinguish different types of AT may be relevant to track the efficacy and mechanisms around interventions aimed to improve metabolic health and thwart excessive weight gain.
Topics: Adipose Tissue, Beige; Adipose Tissue, Brown; Adipose Tissue, White; Animals; Biomarkers; Humans; Species Specificity
PubMed: 33776911
DOI: 10.3389/fendo.2021.599134 -
Nutrients Jul 2022Adipose tissue is the largest and most active endocrine organ, involved in regulating energy balance, glucose and lipid homeostasis and immune function. Adipose tissue... (Review)
Review
Adipose tissue is the largest and most active endocrine organ, involved in regulating energy balance, glucose and lipid homeostasis and immune function. Adipose tissue aging processes are associated with brown adipose tissue whitening, white adipose tissue redistribution and ectopic deposition, resulting in an increase in age-related inflammatory factors, which then trigger a variety of metabolic syndromes, including diabetes and hyperlipidemia. Metabolic syndrome, in turn, is associated with increased inflammatory factors, all-cause mortality and cognitive impairment. There is a growing interest in the role of nutritional interventions in adipose tissue aging. Nowadays, research has confirmed that nutritional interventions, involving caloric restriction and the use of vitamins, resveratrol and other active substances, are effective in managing adipose tissue aging's adverse effects, such as obesity. In this review we summarized age-related physiological characteristics of adipose tissue, and focused on what nutritional interventions can do in improving the retrogradation and how they do this.
Topics: Adipose Tissue; Adipose Tissue, Brown; Adipose Tissue, White; Aging; Caloric Restriction; Humans; Metabolic Diseases; Metabolic Syndrome
PubMed: 35956309
DOI: 10.3390/nu14153134 -
Antioxidants & Redox Signaling Aug 2019Alterations in adipose tissue function have profound consequences on whole body energy homeostasis because this tissue is central for fat accumulation, energy... (Review)
Review
Alterations in adipose tissue function have profound consequences on whole body energy homeostasis because this tissue is central for fat accumulation, energy expenditure, glucose and insulin metabolism, and hormonal regulation. With the obesity reaching epidemic proportions globally, it is important to understand the mechanisms leading to adipose tissue malfunction. Autophagy has originally been viewed as an adaptive response to cellular stress, but in recent years this process was shown to regulate important cellular processes. In adipose tissue, autophagy is a key regulator of white adipose tissue (WAT) and brown adipose tissue (BAT) adipogenesis, and dysregulated autophagy impairs fat accumulation both and Animal studies have also suggested an important role for autophagy and mitophagy during the transition from beige to white fat. Human studies have provided evidence for altered autophagy in WAT, and these alterations correlated with the degree of insulin resistance. Despite these important advances in the study of autophagy in adipose tissue, we still do not understand the physiological role of autophagy in mature white and brown adipocytes. Furthermore, several human studies involving autophagy assessment were performed on whole adipose tissue, which complicates the interpretation of the results considering the cellular heterogeneity of this tissue. Future studies will undoubtedly expand our understanding of the role of autophagy in fully differentiated adipocytes, and uncover novel cross-talks between this tissue and other organs in regulating lipid metabolism, redox signaling, energy homeostasis, and insulin sensitivity.
Topics: Adipose Tissue; Animals; Autophagy; Humans
PubMed: 30234364
DOI: 10.1089/ars.2018.7626 -
Nutrients Jun 2023According to data from the World Health Organization, there were about 3 million deaths caused by alcohol consumption worldwide in 2016, of which about 50% were related... (Review)
Review
According to data from the World Health Organization, there were about 3 million deaths caused by alcohol consumption worldwide in 2016, of which about 50% were related to liver disease. Alcohol consumption interfering with the normal function of adipocytes has an important impact on the pathogenesis of alcoholic liver disease. There has been increasing recognition of the crucial role of adipose tissue in regulating systemic metabolism, far beyond that of an inert energy storage organ in recent years. The endocrine function of adipose tissue is widely recognized, and the significance of the proteins it produces and releases is still being investigated. Alcohol consumption may affect white adipose tissue (WAT) and brown adipose tissue (BAT), which interact with surrounding tissues such as the liver and intestines. This review briefly introduces the basic concept and classification of adipose tissue and summarizes the mechanism of alcohol affecting lipolysis and lipogenesis in WAT and BAT. The adipose tissue-liver axis is crucial in maintaining lipid homeostasis within the body. Therefore, this review also demonstrates the effects of alcohol consumption on the adipose tissue-liver axis to explore the role of alcohol consumption in the crosstalk between adipose tissue and the liver.
Topics: Humans; Lipolysis; Lipogenesis; Adipose Tissue, White; Adipose Tissue; Obesity; Adipose Tissue, Brown; Ethanol
PubMed: 37447280
DOI: 10.3390/nu15132953 -
Current Diabetes Reports Jul 2018As the ongoing epidemic of adult and childhood obesity grows, it puts a greater burden on individuals and the healthcare system due to increased prevalence of... (Review)
Review
PURPOSE OF REVIEW
As the ongoing epidemic of adult and childhood obesity grows, it puts a greater burden on individuals and the healthcare system due to increased prevalence of obesity-associated diseases. An important area that has gained much attention recently is the sex and gender difference related to obesity and associated complications. Basic science and clinical studies have now improved our understanding of obesity and have discovered adipose tissue biology to be key in metabolism.
RECENT FINDINGS
There is evidence related to the sex dichotomy in obesity in a variety of areas including adipocyte function, sex hormone effects, genetics, and metabolic inflammation leading to critical differences in adipose tissue biology. The sex and gender difference in adipose tissue is a factor that should be considered when studying an individuals' risk for obesity and metabolic dysfunction. This understanding is important for strategizing treatment and prevention measures.
Topics: Adipose Tissue; Adiposity; Animals; Female; Gene Expression Regulation; Humans; Inflammation; Male; Models, Animal; Sex Characteristics
PubMed: 30058013
DOI: 10.1007/s11892-018-1031-3 -
Frontiers in Endocrinology 2021Obesity is a major public health concern at the origin of many pathologies, including cancers. Among them, the incidence of gastro-intestinal tract cancers is... (Review)
Review
Obesity is a major public health concern at the origin of many pathologies, including cancers. Among them, the incidence of gastro-intestinal tract cancers is significantly increased, as well as the one of hormone-dependent cancers. The metabolic changes caused by overweight mainly with the development of adipose tissue (AT), insulin resistance and chronic inflammation induce hormonal and/or growth factor imbalances, which impact cell proliferation and differentiation. AT is now considered as the main internal source of endocrine disrupting chemicals (EDCs) representing a low level systemic chronic exposure. Some EDCs are non-metabolizable and can accumulate in AT for a long time. We are chronically exposed to low doses of EDCs able to interfere with the endocrine metabolism of the body. Importantly, several EDCs have been involved in the genesis of obesity affecting profoundly the physiology of AT. In parallel, EDCs have been implicated in the development of cancers, in particular hormone-dependent cancers (prostate, testis, breast, endometrium, thyroid). While it is now well established that AT secretes adipocytokines that promote tumor progression, it is less clear whether they can initiate cancer. Therefore, it is important to better understand the effects of EDCs, and to investigate the buffering effect of AT in the context of progression but also initiation of cancer cells using adequate models recommended to uncover and validate these mechanisms for humans. We will review and argument here the potential role of AT as a crosstalk between EDCs and hormone-dependent cancer development, and how to assess it.
Topics: Adipose Tissue; Animals; Endocrine Disruptors; Environmental Pollutants; Humans; Models, Biological; Neoplasms
PubMed: 34354670
DOI: 10.3389/fendo.2021.691658 -
Surgery For Obesity and Related... Nov 2018Adipose tissue dysfunction underlies the pathogenesis of metabolic disease. The metrics used to quantify adiposity and its association with metabolic disease, including... (Review)
Review
Adipose tissue dysfunction underlies the pathogenesis of metabolic disease. The metrics used to quantify adiposity and its association with metabolic disease, including body mass index, have limitations with important clinical implications. An understanding of the molecular and cellular mechanisms by which adipose tissue regulates systemic metabolism and contributes to metabolic disease will lead to next-generation adipose tissue-based therapy.
Topics: Adipose Tissue; Body Mass Index; Cell- and Tissue-Based Therapy; Humans; Metabolic Diseases; Obesity
PubMed: 30193906
DOI: 10.1016/j.soard.2018.07.032 -
Clinical Nutrition (Edinburgh, Scotland) Dec 2022Computed tomography (CT) scans can measure quantity and distribution of adipose tissue, which are associated with breast cancer prognosis. As a novel prognostic marker,...
BACKGROUND & AIMS
Computed tomography (CT) scans can measure quantity and distribution of adipose tissue, which are associated with breast cancer prognosis. As a novel prognostic marker, radiodensity of adipose tissue has been examined in multiple cancer types, but never in breast cancer. Lower density indicates larger adipocytes with greater lipid content, whereas higher density can reflect inflammation, fibrosis, vascularity, or even metabolic changes; and both may impact breast cancer prognosis.
METHODS
We included 2868 nonmetastatic patients with breast cancer diagnosed between January 2005 and December 2013 at Kaiser Permanente Northern California, an integrated healthcare system. From CT scans at diagnosis, we assessed the radiodensity of subcutaneous (SAT) and visceral adipose tissue (VAT) at the third lumbar vertebra and categorized their radiodensity into three levels: low (<1 standard deviation [SD] below the mean), middle (mean ± 1 SD), and high (>1 SD above the mean). Using multivariable Cox proportional hazards regression with adjustment for clinicopathological characteristics including body mass index, we calculated hazard ratios (HRs [95% confidence intervals]) for the associations of adipose tissue radiodensity with overall mortality and breast-cancer-specific mortality.
RESULTS
Median age at diagnosis of breast cancer was 56.0 years, most (63.3%) were non-Hispanic White and nearly half (45.6%) were stage II. Compared to middle SAT radiodensity, high SAT radiodensity was significantly associated with increased risk of overall mortality (HR: 1.45 [1.15-1.81]), non-significantly with breast-cancer-specific mortality (HR: 1.32 [0.95-1.84]). Neither low SAT radiodensity nor high or low VAT radiodensity was significantly associated with overall or breast-cancer-specific mortality.
CONCLUSIONS
High radiodensity of SAT at diagnosis of nonmetastatic breast cancer was associated with increased risk of overall mortality, independent of adiposity and other prognostic factors. Considering both radiodensity and quantity of adipose tissue at different locations could deepen understanding of the role of adiposity in breast cancer survival.
Topics: Humans; Female; Breast Neoplasms; Adiposity; Adipose Tissue; Intra-Abdominal Fat; Prognosis; Obesity
PubMed: 36306565
DOI: 10.1016/j.clnu.2022.09.016 -
Annals of the New York Academy of... Jan 2018Obesity is an excess accumulation of adipose tissue mass, and, together with its sequelae, in particular type II diabetes and metabolic syndrome, obesity presents a... (Review)
Review
Obesity is an excess accumulation of adipose tissue mass, and, together with its sequelae, in particular type II diabetes and metabolic syndrome, obesity presents a major health crisis. Although obesity is simply caused by increased adipose mass, the heterogeneity of adipose tissue in humans means that the response to increased energy balance is highly complex. Individual subjects with similar phenotypes may respond very differently to the same treatments; therefore, obesity may benefit from a personalized precision medicine approach. The variability in the development of obesity is indeed driven by differences in sex, genetics, and environment, but also by the various types of adipose tissue as well as the different cell types that compose it. By describing the distinct cell populations that reside in different fat depots, we can interpret the complex effect of these various players in the maintenance of whole-body energy homeostasis. To further understand adipose tissue, adipogenic differentiation and the transcriptional program of lipid accumulation must be investigated. As the cell- and depot-specific functions are described, they can be placed in the context of energy excess to understand how the heterogeneity of adipose tissue shapes individual metabolic status and condition.
Topics: Adipocytes; Adipogenesis; Adipose Tissue; Animals; Endothelial Cells; Energy Metabolism; Female; Humans; Lipolysis; Macrophages; Male; Mice; Myocytes, Smooth Muscle; Neurons; Obesity; Sex Characteristics
PubMed: 28763833
DOI: 10.1111/nyas.13398 -
Journal of Molecular Cell Biology Oct 2020The obesity epidemic continues to rise as a global health challenge. Thermogenic brown and beige adipocytes dissipate chemical energy as heat, providing an opportunity... (Review)
Review
The obesity epidemic continues to rise as a global health challenge. Thermogenic brown and beige adipocytes dissipate chemical energy as heat, providing an opportunity for developing new therapeutics for obesity and related metabolic diseases. Anatomically, brown adipose tissue is distributed as discrete depots, while beige adipocytes exist within certain depots of white adipose tissue. Developmentally, brown and beige adipocytes arise from multiple embryonic progenitor populations that are distinct and overlapping. Functionally, they respond to a plethora of stimuli to engage uncoupling protein 1-dependent and independent thermogenic programs, thus improving systemic glucose homeostasis, lipid metabolism, and the clearance of branched-chain amino acids. In this review, we highlight recent advances in our understanding of the molecular and cellular mechanisms that contribute to the developmental and functional heterogeneity of thermogenic adipose tissue.
Topics: Adipocytes; Adipose Tissue; Aging; Animals; Cell Lineage; Humans; Models, Biological; Thermogenesis
PubMed: 32569352
DOI: 10.1093/jmcb/mjaa029