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Adipocyte function is a major determinant of metabolic disease, warranting investigations of regulating mechanisms. We show at single-cell resolution that progenitor cells from four human brown and white adipose depots separate into two main cell fates, an adipogenic and a structural branch, developing from a common progenitor. The adipogenic gene signature contains mitochondrial activity genes, and associates with genome-wide association study traits for fat distribution. Based on an extracellular matrix and developmental gene signature, we name the structural branch of cells structural Wnt-regulated adipose tissue-resident (SWAT) cells. When stripped from adipogenic cells, SWAT cells display a multipotent phenotype by reverting towards progenitor state or differentiating into new adipogenic cells, dependent on media. Label transfer algorithms recapitulate the cell types in human adipose tissue datasets. In conclusion, we provide a differentiation map of human adipocytes and define the multipotent SWAT cell, providing a new perspective on adipose tissue regulation.
Assuntos
Tecido Adiposo Marrom , Estudo de Associação Genômica Ampla , Humanos , Tecido Adiposo Marrom/metabolismo , Adipogenia/genética , Obesidade/metabolismo , Diferenciação Celular/genéticaRESUMO
Activation of thermogenic adipose tissue is linked to improved metabolic outcomes in mice and humans. Dissipation of energy as heat during thermogenesis relies on sufficient innervation of fat by sympathetic nerve fibers, a process recently proposed to be regulated by the adipose-specific calsyntenin3ß (Clstn3ß)-S100b axis. Here we aimed 1) to assess enrichment patterns of CLSTN3ß, S100b as well as the previously annotated neuronal CLSTN3α in perirenal brown and subcutaneous white human fat specimens, and 2) to investigate if the novel Clstn3ß is dynamically regulated by changes in environmental temperatures and nutritional stress in thermogenic adipose tissues in mice. We provide evidence for CLSTN3ß enrichment in multilocular perirenal fat located anatomically in the proximity to both the adrenal gland and sympathetic nerve bundles innervating the kidney in humans. Moreover, transcript levels of CLSTN3ß, but not S100b or CLSTN3α, positively correlate with uncoupling protein 1 (UCP1) expression in human adipose tissue. Our results further show that Clsnt3ß is preferentially expressed in brown adipocytes and is highly responsive to changes in environmental temperature and obesity state in mice. Collectively, this brief communication highlights CLSTN3ß as a hallmark of thermogenic adipose depots in mice and humans.
Assuntos
Tecido Adiposo Marrom/patologia , Proteínas de Ligação ao Cálcio/metabolismo , Dieta Hiperlipídica/efeitos adversos , Resposta ao Choque Térmico , Proteínas de Membrana/metabolismo , Obesidade/fisiopatologia , Termogênese , Tecido Adiposo Marrom/metabolismo , Adulto , Idoso , Animais , Proteínas de Ligação ao Cálcio/genética , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Gordura SubcutâneaRESUMO
Stimulation of brown adipose tissue (BAT) thermogenesis in humans has emerged as an attractive target to improve metabolic health. Pharmacological stimulations targeting the ß3-adrenergic receptor (ß3-AR), the adrenergic receptor believed to mediate BAT thermogenesis, have historically performed poorly in human clinical trials. Here we report that, in contrast to rodents, human BAT thermogenesis is not mediated by the stimulation of ß3-AR. Oral administration of the ß3-AR agonist mirabegron only elicited increases in BAT thermogenesis when ingested at the maximal allowable dose. This led to off-target binding to ß1-AR and ß2-AR, thereby increasing cardiovascular responses and white adipose tissue lipolysis, respectively. ADRB2 was co-expressed with UCP1 in human brown adipocytes. Pharmacological stimulation and inhibition of the ß2-AR as well as knockdown of ADRB1, ADRB2, or ADRB3 in human brown adipocytes all confirmed that BAT lipolysis and thermogenesis occur through ß2-AR signaling in humans (ClinicalTrials.govNCT02811289).
Assuntos
Adipócitos Marrons/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Termogênese , Adolescente , Adulto , Animais , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Adulto JovemRESUMO
OBJECTIVE: The primary objective was to test the hypothesis that increased frequency of interruptions in prolonged sitting reduces postprandial glycemia independent of energy intake and expenditure. MATERIALS/METHODS: Healthy, sedentary, centrally obese men (nâ¯=â¯14; age*, 28.2 (23.4; 38.3) years; BMI, 31.9⯱â¯6.7â¯kg/m2; VO2max*, 39.5 (38.8; 40.9) ml/min/kg; HbA1c, 5.3⯱â¯0.4% (34.1⯱â¯4.2â¯mmol/mol); mean⯱â¯SD (*median (25th; 75th percentile)) completed four 8-h interventions in randomized order: 1) uninterrupted sitting (SIT), 2) sitting interrupted by 2â¯min of walking (~30% of VO2max) every 20th minute (INT20), 3) sitting interrupted by 6â¯min of walking every hour (INT60), and 4) sitting interrupted by 12â¯min of walking every second hour (INT120). A standardized test drink was served at the beginning of and 4â¯h into the intervention (total of 2310⯱â¯247â¯kcal; 50% energy from carbohydrate, 50% energy from fat). Outcomes included the difference in the 8-h total area under the curve (tAUC) for primarily plasma glucose, and secondarily plasma insulin and C-peptide during INT20, INT60, and INT120 compared to SIT. RESULTS: No difference [95% CI] was observed in the primary outcome, the 8-h tAUC for the plasma glucose, during INT20, INT60, and INT120 compared to SIT (-65.3â¯mmol/l∗min [-256.3; 125.7], +53.8â¯mmol/l∗min [-143.1; 250.8], and +18.6â¯mmol/l∗min [-172.4; 209.6], respectively). CONCLUSIONS: Interrupting sitting with increasing frequency did not reduce the postprandial plasma glucose response to prolonged sitting in healthy, sedentary, centrally obese men.
Assuntos
Glicemia/metabolismo , Exercício Físico/fisiologia , Postura Sentada , Adulto , Limiar Anaeróbio , Índice de Massa Corporal , Peptídeo C/sangue , Estudos Cross-Over , Hemoglobinas Glicadas/análise , Humanos , Insulina/sangue , Masculino , Pessoa de Meia-Idade , Obesidade Abdominal/fisiopatologia , Período Pós-Prandial , Comportamento Sedentário , Caminhada , Adulto JovemRESUMO
OBJECTIVE: Increasing the amounts of functionally competent brown adipose tissue (BAT) in adult humans has the potential to restore dysfunctional metabolism and counteract obesity. In this study, we aimed to characterize the human perirenal fat depot, and we hypothesized that there would be regional, within-depot differences in the adipose signature depending on local sympathetic activity. METHODS: We characterized fat specimens from four different perirenal regions of adult kidney donors, through a combination of qPCR mapping, immunohistochemical staining, RNA-sequencing, and pre-adipocyte isolation. Candidate gene signatures, separated by adipocyte morphology, were recapitulated in a murine model of unilocular brown fat induced by thermoneutrality and high fat diet. RESULTS: We identified widespread amounts of dormant brown adipose tissue throughout the perirenal depot, which was contrasted by multilocular BAT, primarily found near the adrenal gland. Dormant BAT was characterized by a unilocular morphology and a distinct gene expression profile, which partly overlapped with that of subcutaneous white adipose tissue (WAT). Brown fat precursor cells, which differentiated into functional brown adipocytes were present in the entire perirenal fat depot, regardless of state. We identified SPARC as a candidate adipokine contributing to a dormant BAT state, and CLSTN3 as a novel marker for multilocular BAT. CONCLUSIONS: We propose that perirenal adipose tissue in adult humans consists mainly of dormant BAT and provide a data set for future research on factors which can reactivate dormant BAT into active BAT, a potential strategy for combatting obesity and metabolic disease.
Assuntos
Adipócitos Marrons/citologia , Tecido Adiposo Marrom/citologia , Rim/citologia , Células-Tronco Mesenquimais/citologia , Adipócitos Marrons/metabolismo , Adulto , Idoso , Animais , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Células Cultivadas , Feminino , Humanos , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos , Pessoa de Meia-Idade , Osteonectina/genética , Osteonectina/metabolismoRESUMO
Mesenchymal (stromal) stem cells (MSCs) constitute populations of mesodermal multipotent cells involved in tissue regeneration and homeostasis in many different organs. Here we performed comprehensive characterization of the transcriptional and epigenomic changes associated with osteoblast and adipocyte differentiation of human MSCs. We demonstrate that adipogenesis is driven by considerable remodeling of the chromatin landscape and de novo activation of enhancers, whereas osteogenesis involves activation of preestablished enhancers. Using machine learning algorithms for in silico modeling of transcriptional regulation, we identify a large and diverse transcriptional network of pro-osteogenic and antiadipogenic transcription factors. Intriguingly, binding motifs for these factors overlap with SNPs related to bone and fat formation in humans, and knockdown of single members of this network is sufficient to modulate differentiation in both directions, thus indicating that lineage determination is a delicate balance between the activities of many different transcription factors.
Assuntos
Adipogenia/genética , Osteogênese/genética , Fator de Células-Tronco/genética , Fatores de Transcrição/genética , Células A549 , Adipócitos/fisiologia , Diferenciação Celular/genética , Linhagem Celular Tumoral , Células Cultivadas , Células HEK293 , Humanos , Células-Tronco Mesenquimais/fisiologia , Osteoblastos/fisiologia , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
Human and rodent brown adipose tissues (BAT) appear morphologically and molecularly different. Here we compare human BAT with both classical brown and brite/beige adipose tissues of 'physiologically humanized' mice: middle-aged mice living under conditions approaching human thermal and nutritional conditions, that is, prolonged exposure to thermoneutral temperature (approximately 30 °C) and to an energy-rich (high-fat, high-sugar) diet. We find that the morphological, cellular and molecular characteristics (both marker and adipose-selective gene expression) of classical brown fat, but not of brite/beige fat, of these physiologically humanized mice are notably similar to human BAT. We also demonstrate, both in silico and experimentally, that in physiologically humanized mice only classical BAT possesses a high thermogenic potential. These observations suggest that classical rodent BAT is the tissue of choice for translational studies aimed at recruiting human BAT to counteract the development of obesity and its comorbidities.
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Tecido Adiposo Marrom/fisiologia , Animais , Humanos , Camundongos , TermogêneseRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
In the version of this article initially published, in the graph keys in Fig. 1i, the colors indicating 'Ob' and 'Ad' were red and blue, respectively, but should have been blue and red, respectively; the shapes indicating 'MUS' and 'BM' were a triangle and a square, respectively, but should have been a square and a triangle, respectively. The errors have been corrected in the HTML and PDF versions of the article.
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Adipokines secreted from white adipose tissue play a role in metabolic crosstalk and homeostasis, whereas the brown adipose secretome is less explored. We performed high-sensitivity mass-spectrometry-based proteomics on the cell media of human adipocytes derived from the supraclavicular brown adipose and from the subcutaneous white adipose depots of adult humans. We identified 471 potentially secreted proteins covering interesting categories such as hormones, growth factors, extracellular matrix proteins, and proteins of the complement system, which were differentially regulated between brown and white adipocytes. A total of 101 proteins were exclusively quantified in brown adipocytes, and among these was ependymin-related protein 1 (EPDR1). EPDR1 was detected in human plasma, and functional studies suggested a role for EPDR1 in thermogenic determination during adipogenesis. In conclusion, we report substantial differences between the secretomes of brown and white human adipocytes and identify novel candidate batokines that can be important regulators of human metabolism.
Assuntos
Adipócitos Marrons/metabolismo , Adipócitos Brancos/metabolismo , Tecido Adiposo Marrom/metabolismo , Proteínas de Neoplasias/sangue , Proteômica/métodos , Adulto , Idoso , Animais , Estudos de Coortes , Feminino , Técnicas de Silenciamento de Genes , Bócio/sangue , Bócio/patologia , Bócio/cirurgia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Proteínas do Tecido Nervoso , Via Secretória/genética , Transdução de Sinais/genética , Transfecção , Adulto JovemRESUMO
Activation of energy expenditure in thermogenic fat is a promising strategy to improve metabolic health, yet the dynamic processes that evoke this response are poorly understood. Here we show that synthesis of the mitochondrial phospholipid cardiolipin is indispensable for stimulating and sustaining thermogenic fat function. Cardiolipin biosynthesis is robustly induced in brown and beige adipose upon cold exposure. Mimicking this response through overexpression of cardiolipin synthase (Crls1) enhances energy consumption in mouse and human adipocytes. Crls1 deficiency in thermogenic adipocytes diminishes inducible mitochondrial uncoupling and elicits a nuclear transcriptional response through endoplasmic reticulum stress-mediated retrograde communication. Cardiolipin depletion in brown and beige fat abolishes adipose thermogenesis and glucose uptake, which renders animals insulin resistant. We further identify a rare human CRLS1 variant associated with insulin resistance and show that adipose CRLS1 levels positively correlate with insulin sensitivity. Thus, adipose cardiolipin has a powerful impact on organismal energy homeostasis through thermogenic fat bioenergetics.
Assuntos
Adipócitos/metabolismo , Tecido Adiposo Bege/metabolismo , Tecido Adiposo Marrom/metabolismo , Cardiolipinas/biossíntese , Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Transferases (Outros Grupos de Fosfato Substituídos)/metabolismo , Animais , Células Cultivadas , Metabolismo Energético , Humanos , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Termogênese , Transferases (Outros Grupos de Fosfato Substituídos)/genéticaRESUMO
The liking and selective ingestion of palatable foods-including sweets-is biologically controlled, and dysfunction of this regulation may promote unhealthy eating, obesity, and disease. The hepatokine fibroblast growth factor 21 (FGF21) reduces sweet consumption in rodents and primates, whereas knockout of Fgf21 increases sugar consumption in mice. To investigate the relevance of these findings in humans, we genotyped variants in the FGF21 locus in participants from the Danish Inter99 cohort (n = 6,514) and examined their relationship with a detailed range of food and ingestive behaviors. This revealed statistically significant associations between FGF21 rs838133 and increased consumption of candy, as well as nominal associations with increased alcohol intake and daily smoking. Moreover, in a separate clinical study, plasma FGF21 levels increased acutely after oral sucrose ingestion and were elevated in fasted sweet-disliking individuals. These data suggest the liver may secrete hormones that influence eating behavior.
Assuntos
Doces , Fatores de Crescimento de Fibroblastos/genética , Preferências Alimentares , Polimorfismo Genético , Açúcares/metabolismo , Adulto , Apetite , Regulação do Apetite , Estudos de Coortes , Feminino , Fatores de Crescimento de Fibroblastos/sangue , Fatores de Crescimento de Fibroblastos/metabolismo , Genótipo , Humanos , Masculino , Obesidade/genética , Obesidade/metabolismo , Paladar , Adulto JovemRESUMO
Brown fat dissipates energy as heat and protects against obesity. Here, we identified nuclear factor I-A (NFIA) as a transcriptional regulator of brown fat by a genome-wide open chromatin analysis of murine brown and white fat followed by motif analysis of brown-fat-specific open chromatin regions. NFIA and the master transcriptional regulator of adipogenesis, PPARγ, co-localize at the brown-fat-specific enhancers. Moreover, the binding of NFIA precedes and facilitates the binding of PPARγ, leading to increased chromatin accessibility and active transcription. Introduction of NFIA into myoblasts results in brown adipocyte differentiation. Conversely, the brown fat of NFIA-knockout mice displays impaired expression of the brown-fat-specific genes and reciprocal elevation of muscle genes. Finally, expression of NFIA and the brown-fat-specific genes is positively correlated in human brown fat. These results indicate that NFIA activates the cell-type-specific enhancers and facilitates the binding of PPARγ to control the brown fat gene program.