RESUMO
Brown fat generates heat via the mitochondrial uncoupling protein UCP1, defending against hypothermia and obesity. Recent data suggest that there are two distinct types of brown fat: classical brown fat derived from a myf-5 cellular lineage and UCP1-positive cells that emerge in white fat from a non-myf-5 lineage. Here, we report the isolation of "beige" cells from murine white fat depots. Beige cells resemble white fat cells in having extremely low basal expression of UCP1, but, like classical brown fat, they respond to cyclic AMP stimulation with high UCP1 expression and respiration rates. Beige cells have a gene expression pattern distinct from either white or brown fat and are preferentially sensitive to the polypeptide hormone irisin. Finally, we provide evidence that previously identified brown fat deposits in adult humans are composed of beige adipocytes. These data provide a foundation for studying this mammalian cell type with therapeutic potential. PAPERCLIP:
Assuntos
Adipócitos/classificação , Adipócitos/metabolismo , Adipócitos Brancos/metabolismo , Tecido Adiposo Marrom/metabolismo , Animais , Separação Celular , Perfilação da Expressão Gênica , Humanos , Canais Iônicos/metabolismo , Camundongos , Proteínas Mitocondriais/metabolismo , Proteína Desacopladora 1RESUMO
Cardiovascular disease is the leading cause of death worldwide. Advanced insights into disease mechanisms and therapeutic strategies require a deeper understanding of the molecular processes involved in the healthy heart. Knowledge of the full repertoire of cardiac cells and their gene expression profiles is a fundamental first step in this endeavour. Here, using state-of-the-art analyses of large-scale single-cell and single-nucleus transcriptomes, we characterize six anatomical adult heart regions. Our results highlight the cellular heterogeneity of cardiomyocytes, pericytes and fibroblasts, and reveal distinct atrial and ventricular subsets of cells with diverse developmental origins and specialized properties. We define the complexity of the cardiac vasculature and its changes along the arterio-venous axis. In the immune compartment, we identify cardiac-resident macrophages with inflammatory and protective transcriptional signatures. Furthermore, analyses of cell-to-cell interactions highlight different networks of macrophages, fibroblasts and cardiomyocytes between atria and ventricles that are distinct from those of skeletal muscle. Our human cardiac cell atlas improves our understanding of the human heart and provides a valuable reference for future studies.
Assuntos
Miocárdio/citologia , Análise de Célula Única , Transcriptoma , Adipócitos/classificação , Adipócitos/metabolismo , Adulto , Enzima de Conversão de Angiotensina 2/análise , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/metabolismo , Células Epiteliais/classificação , Células Epiteliais/metabolismo , Epitélio , Feminino , Fibroblastos/classificação , Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Estudo de Associação Genômica Ampla , Átrios do Coração/anatomia & histologia , Átrios do Coração/citologia , Átrios do Coração/inervação , Ventrículos do Coração/anatomia & histologia , Ventrículos do Coração/citologia , Ventrículos do Coração/inervação , Homeostase/imunologia , Humanos , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Músculo Esquelético/citologia , Músculo Esquelético/metabolismo , Miócitos Cardíacos/classificação , Miócitos Cardíacos/metabolismo , Neurônios/classificação , Neurônios/metabolismo , Pericitos/classificação , Pericitos/metabolismo , Receptores de Coronavírus/análise , Receptores de Coronavírus/genética , Receptores de Coronavírus/metabolismo , SARS-CoV-2/metabolismo , SARS-CoV-2/patogenicidade , Células Estromais/classificação , Células Estromais/metabolismoRESUMO
Ceiling culture-derived preadipocytes (ccdPAs) and adipose-derived stem cells (ASCs) can be harvested from human subcutaneous fat tissue using the specific gravity method. Both cell types possess a similar spindle shape without lipid droplets. We previously reported that ccdPAs have a higher adipogenic potential than ASCs, even after a 7-wk culture. We performed a genome-wide epigenetic analysis to examine the mechanisms contributing to the adipogenic potential differences between ccdPAs and ASCs. Methylation analysis of cytosines followed by guanine (CpG) using a 450-K BeadChip was performed on human ccdPAs and ASCs isolated from three metabolically healthy females. Chromatin immunoprecipitation sequencing was performed to evaluate trimethylation at lysine 4 of histone 3 (H3K4me3). Unsupervised machine learning using t-distributed stochastic neighbor embedding to interpret 450,000-dimensional methylation assay data showed that the cells were divided into ASC and ccdPA groups. In Kyoto Encyclopedia of Genes and Genomes pathway analysis of 1,543 genes with differential promoter CpG methylation, the peroxisome proliferator-activated receptor (PPAR) and adipocytokine signaling pathways ranked in the top 10 pathways. In the PPARγ gene, H3K4me3 peak levels were higher in ccdPAs than in ASCs, whereas promoter CpG methylation levels were significantly lower in ccdPAs than in ASCs. Similar differences in promoter CpG methylation were also seen in the fatty acid-binding protein 4 and leptin genes. In conclusion, we analyzed the epigenetic status of adipogenesis-related genes as a potential mechanism underlying the differences in adipogenic differentiation capability between ASCs and ccdPAs.
Assuntos
Adipócitos/metabolismo , Adipogenia/genética , Adipocinas/genética , Epigênese Genética , Células-Tronco Mesenquimais/metabolismo , PPAR gama/genética , Adipócitos/classificação , Adipócitos/citologia , Adipocinas/metabolismo , Ilhas de CpG , Metilação de DNA , Proteínas de Ligação a Ácido Graxo/genética , Proteínas de Ligação a Ácido Graxo/metabolismo , Feminino , Perfilação da Expressão Gênica , Estudo de Associação Genômica Ampla , Histonas/genética , Histonas/metabolismo , Humanos , Leptina/genética , Leptina/metabolismo , Mamoplastia/métodos , Glândulas Mamárias Humanas/citologia , Glândulas Mamárias Humanas/metabolismo , Glândulas Mamárias Humanas/cirurgia , Células-Tronco Mesenquimais/classificação , Células-Tronco Mesenquimais/citologia , Especificidade de Órgãos , PPAR gama/metabolismo , Cultura Primária de Células , Gordura Subcutânea/citologia , Gordura Subcutânea/metabolismo , Aprendizado de Máquina não SupervisionadoRESUMO
OBJECTIVE: Cell diameter, area, and volume are established quantitative measures of adipocyte size. However, these different adipocyte sizing parameters have not yet been directly compared regarding their distributions. Therefore, the study aimed to investigate how these adipocyte size measures differ in their distribution and assessed their correlation with anthropometry and laboratory chemistry. In addition, we were interested to investigate the relationship between fat cell size and adipocyte mitochondrial respiratory chain capacity. METHODS: Subcutaneous and visceral histology-based adipocyte size estimates from 188 individuals were analyzed by applying a panel of parameters to describe the underlying cell population. Histology-based adipocyte diameter distributions were compared with adipocyte diameter distributions from collagenase digestion. Associations of mean adipocyte size with body mass index (BMI), glucose, HbA1C, blood lipids as well as mature adipocyte mitochondrial respiration were investigated. RESULTS: All adipocyte area estimates derived from adipose tissue histology were not normally distributed, but rather characterized by positive skewness. The shape of the size distribution depends on the adipocyte sizing parameter and on the method used to determine adipocyte size. Despite different distribution shapes histology-derived adipocyte area, diameter, volume, and surface area consistently showed positive correlations with BMI. Furthermore, associations between adipocyte sizing parameters and glucose, HbA1C, or HDL specifically in the visceral adipose depot were revealed. Increasing subcutaneous adipocyte diameter was negatively correlated with adipocyte mitochondrial respiration. CONCLUSIONS: Despite different underlying size distributions, the correlation with obesity-related traits was consistent across adipocyte sizing parameters. Decreased mitochondrial respiratory capacity with increasing subcutaneous adipocyte diameter could display a novel link between adipocyte hypertrophy and adipose tissue function.
Assuntos
Adipócitos/classificação , Obesidade/fisiopatologia , Pesos e Medidas/normas , Adipócitos/fisiologia , Tecido Adiposo/metabolismo , Adulto , Índice de Massa Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/fisiologia , Pesos e Medidas/instrumentaçãoRESUMO
Genetic studies have recently highlighted the importance of fat distribution, as well as overall adiposity, in the pathogenesis of obesity-associated diseases. Using a large study (n = 1,288) from 4 independent cohorts, we aimed to investigate the relationship between mean adipocyte area and obesity-related traits, and identify genetic factors associated with adipocyte cell size. To perform the first large-scale study of automatic adipocyte phenotyping using both histological and genetic data, we developed a deep learning-based method, the Adipocyte U-Net, to rapidly derive mean adipocyte area estimates from histology images. We validate our method using three state-of-the-art approaches; CellProfiler, Adiposoft and floating adipocytes fractions, all run blindly on two external cohorts. We observe high concordance between our method and the state-of-the-art approaches (Adipocyte U-net vs. CellProfiler: R2visceral = 0.94, P < 2.2 × 10-16, R2subcutaneous = 0.91, P < 2.2 × 10-16), and faster run times (10,000 images: 6mins vs 3.5hrs). We applied the Adipocyte U-Net to 4 cohorts with histology, genetic, and phenotypic data (total N = 820). After meta-analysis, we found that mean adipocyte area positively correlated with body mass index (BMI) (Psubq = 8.13 × 10-69, ßsubq = 0.45; Pvisc = 2.5 × 10-55, ßvisc = 0.49; average R2 across cohorts = 0.49) and that adipocytes in subcutaneous depots are larger than their visceral counterparts (Pmeta = 9.8 × 10-7). Lastly, we performed the largest GWAS and subsequent meta-analysis of mean adipocyte area and intra-individual adipocyte variation (N = 820). Despite having twice the number of samples than any similar study, we found no genome-wide significant associations, suggesting that larger sample sizes and a homogenous collection of adipose tissue are likely needed to identify robust genetic associations.
Assuntos
Adipócitos , Aprendizado de Máquina , Obesidade , Adipócitos/classificação , Adipócitos/citologia , Tecido Adiposo/fisiologia , Adulto , Índice de Massa Corporal , Tamanho Celular , Biologia Computacional/métodos , Feminino , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Redes Neurais de Computação , Obesidade/epidemiologia , Obesidade/genética , Fenótipo , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
Our previous studies showed that microRNA-15a (miR-15a) was closely related to intramuscular fat (IMF) deposition in chickens; however, its regulatory mechanism remains unclear. Here, we evaluated the expression characteristics of miR-15a and its relationship with the expression of acetyl-CoA acyltransferase 1 (ACAA1), acyl-CoA oxidase 1 (ACOX1) and sterol carrier protein 2 (SCP2) by qPCR analysis in Gushi chicken breast muscle at 6, 14, 22, and 30 weeks old, where we performed transfection tests of miR-15a mimics in intramuscular preadipocytes and verified the target gene of miR-15a in chicken fibroblasts (DF1). The miR-15a expression level at 30 weeks increased 13.5, 4.5, and 2.7-fold compared with the expression levels at 6, 14, and 22 weeks, respectively. After 6 days of induction, miR-15a over-expression significantly promoted intramuscular adipogenic differentiation and increased cholesterol and triglyceride accumulation in adipocytes. Meanwhile, 48 h after transfection with miR-15a mimics, the expression levels of ACAA1, ACOX1 and SCP2 genes decreased by 56.52%, 31.18% and 37.14% at the mRNA level in intramuscular preadipocytes. In addition, the co-transfection of miR-15a mimics and ACAA1, ACOX1 and SCP2 3'UTR (untranslated region) dual-luciferase vector significantly inhibited dual-luciferase activity in DF1 cells. Taken together, our data demonstrate that miR-15a can reduce fatty acid oxidation by targeting ACAA1, ACOX1, and SCP2, which subsequently indirectly promotes the differentiation of chicken intramuscular preadipocytes.
Assuntos
Acetil-CoA C-Aciltransferase/metabolismo , Adipócitos/classificação , Adipócitos/metabolismo , Proteínas de Transporte/metabolismo , Diferenciação Celular/fisiologia , MicroRNAs/metabolismo , Acetil-CoA C-Aciltransferase/genética , Animais , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Transporte/genética , Diferenciação Celular/genética , Galinhas , MicroRNAs/genéticaRESUMO
There are three different types of adipose tissue (AT)-brown, white, and beige-that differ with stage of development, species, and anatomical location. Of these, brown AT (BAT) is the least abundant but has the greatest potential impact on energy balance. BAT is capable of rapidly producing large amounts of heat through activation of the unique uncoupling protein 1 (UCP1) located within the inner mitochondrial membrane. White AT is an endocrine organ and site of lipid storage, whereas beige AT is primarily white but contains some cells that possess UCP1. BAT first appears in the fetus around mid-gestation and is then gradually lost through childhood, adolescence, and adulthood. We focus on the interrelationships between adipocyte classification, anatomical location, and impact of diet in early life together with the extent to which fat development differs between the major species examined. Ultimately, novel dietary interventions designed to reactivate BAT could be possible.
Assuntos
Tecido Adiposo Marrom/crescimento & desenvolvimento , Tecido Adiposo Marrom/fisiologia , Adipócitos/classificação , Adipócitos/fisiologia , Tecido Adiposo/embriologia , Tecido Adiposo/crescimento & desenvolvimento , Tecido Adiposo Marrom/embriologia , Tecido Adiposo Branco/fisiologia , Animais , Dieta , Metabolismo Energético/fisiologia , Epigênese Genética , Feminino , Desenvolvimento Fetal , Idade Gestacional , Humanos , Canais Iônicos/fisiologia , Fenômenos Fisiológicos da Nutrição Materna , Proteínas Mitocondriais/fisiologia , Gravidez , Termogênese/fisiologia , Proteína Desacopladora 1RESUMO
Every cell reserves fatty acids in cytozol in drops of lipids in the form of non-polar triglycerides for itself andfor oxidation in mitochondria. The specialized visceral fatty cells ofomentum and adipocytes ofsubcutaneous fat are the cells absorbing saturated and mono unsaturated fatty acids in form of triglycerides in apoB-48 chylomicrons, apoB-100 lipoproteins of low and very low density. They deposit their physiological time and liberate fatty acids in intercellular medium in the form ofpolar unesterified fatty acids bound by albumin. According phylogenetic theory of general pathology, in biological function of trophology (nutrition) fatty cells sequentially implement biological reaction of exotrophy (external nutrition), deposition and endotrophy (internal nutrition). The humoral regulator offeedback in visceral fatty cells is leptin acting in autocrine way, in paracrin cenosises of cells and on the level of organism. The biological role of leptin is in preventing a) deposition of surplus amount of non-polar triglycerides in fatty cells; b) formation of endoplasmic "stress"; c) death of fatty cells in apoptosis way, formation of corpuscles of apoptosis and failure of biological function of endoecology; d) formation of biological reaction of inflammation in visceral fatty tissue; e) high level of unsaturated fatty acids in intercellular medium and f) development of metabolic syndrome. The leptin prevents aphysiological deposit ofnon-polar triglycerides in insulin-dependent cells that are not intended to deposit non-polar triglycerides and also in ß-cells of islands. The main cause of high level ofleptin in blood plasma is overeating offood physiological by content of nutrients.
Assuntos
Adipócitos/metabolismo , Tecido Adiposo Marrom/metabolismo , Hiperfagia/metabolismo , Gordura Intra-Abdominal/metabolismo , Síndrome Metabólica/metabolismo , Adipócitos/classificação , Adipócitos/patologia , Adiponectina/genética , Adiponectina/metabolismo , Tecido Adiposo Marrom/patologia , Quilomícrons/metabolismo , Ácidos Graxos/metabolismo , Regulação da Expressão Gênica , Humanos , Hiperfagia/genética , Hiperfagia/patologia , Gordura Intra-Abdominal/patologia , Leptina/genética , Leptina/metabolismo , Metabolismo dos Lipídeos , Síndrome Metabólica/genética , Síndrome Metabólica/patologia , Mitocôndrias/metabolismo , Transdução de Sinais , Triglicerídeos/metabolismoRESUMO
For billions years, two phylogenetically, functionally and regulatory different pools of fatty cells - visceral fatty acids and adipocytes coexist in vivo. Their becoming occurred at different degrees of phylogenesis. The phylogenetically earlier pool of visceral fatty acids is meant to supply with fatty acids-substrates for gaining energy by those cells which implement biological function of nutrition (trophology), homeostasis, endoecology biological function of adaptation and continuation of species. They have no receptors to phylogenetically later insulin. The adipocytes, later in phylogenesis, implement one biological function - the function of locomotion and they are as insulin-dependent as skeletal myocytes, cardiomyocytes, adipocytes and periportal hepatocytes. The difference in regulation is traced on all levels of "biological perfection " - autocrine (cellular) level, in humoral regulated paracrin cenosises of cells and on the level of organism. In biological function of trophology, paracrin cenosises of visceral fatty acids and adipocytes implement subsequently three biological reactions: exotrophy, deposit of fatty acids and endotrophy. In conditions of humoral regulation of three functionally different biological reactions in paracrin cenosises synthesis of so many humoral mediators is required. The humoral mediators of mechanism of feedback at autocrine level, in paracrin cenosises and at the level of organism are leptin of visceral fatty acids and adiponectin of adipocytes. At the level of organism, phylogenetically earlier paracrin cenosises of fatty cells are regulated by endocrine system. The phylogenetically later paracrin cenosises are regulated by insulin and nuclei of hypothalamus. The metabolic syndrome is a pathology of phylogenetically earlier insulin-independent visceral fatty acids. The obesity is a pathology of phylogenetically later pool of insulin-dependent adipocytes.
Assuntos
Adipócitos/metabolismo , Tecido Adiposo Marrom/metabolismo , Gordura Intra-Abdominal/metabolismo , Síndrome Metabólica/metabolismo , Adipócitos/classificação , Adipócitos/patologia , Adiponectina/genética , Adiponectina/metabolismo , Tecido Adiposo Marrom/patologia , Comunicação Autócrina , Ácidos Graxos/metabolismo , Regulação da Expressão Gênica , Humanos , Gordura Intra-Abdominal/patologia , Leptina/genética , Leptina/metabolismo , Metabolismo dos Lipídeos , Síndrome Metabólica/genética , Síndrome Metabólica/patologia , Mitocôndrias/metabolismo , Comunicação Parácrina , Filogenia , Transdução de SinaisRESUMO
The regulation of metabolism in vivo can be comprehended by considering stages of becoming inphylogenesis of humoral, hormonal, vegetative regulators separately: at the level of cells; in paracrin-regulated cenosises of cells; organs and systems under open blood circulation and closed system of blood flow. The levels of regulations formed at different stages of phylogenesis. Their completion occurred at achievement of "relative biological perfection". Only this way need of cells in functional, structural interaction and forming of multicellular developed. The development of organs and systems of organs also completed at the level of "relative biological perfection". From the same level the third stage of becoming of regulation of metabolism at the level of organism started. When three conditions of "relative biological perfection" achieved consequently at level in vivo are considered in species Homo sapiens using system approach it is detected that "relative biological perfection" in vivo is accompanied by different inconsistencies of regulation of metabolism. They are etiologic factors of "metabolic pandemics ". The inconsistencies (etiological factors) are consider as exemplified by local (at the level of paracrin-regulated cenosises of cells) and system (at the level of organism) regulation of biological reaction metabolism-microcirculation that results in dysfunction of target organs and development of pathogenesis of essential metabolic arterial hypertension. The article describes phylogenetic difference between visceral fatty cells and adpocytes, regulation of metabolism by phylogenetically late insulin, reaction of albumin at increasing of content of unesterified fatty acids in blood plasma, difference of function of resident macrophage and monocytes-macrophages in pathogenesis of atherosclerosis, metabolic syndrome, insulin resistance, obesity, under diabetes mellitus and essential metabolic arterial hypertension.
Assuntos
Diabetes Mellitus/epidemiologia , Hipertensão/epidemiologia , Síndrome Metabólica/epidemiologia , Obesidade/epidemiologia , Pandemias , Filogenia , Adipócitos/classificação , Adipócitos/metabolismo , Adipócitos/patologia , Albuminas/metabolismo , Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Diabetes Mellitus/patologia , Hipertensão Essencial , Ácidos Graxos não Esterificados/metabolismo , Humanos , Hipertensão/genética , Hipertensão/metabolismo , Hipertensão/patologia , Insulina/metabolismo , Resistência à Insulina , Macrófagos/metabolismo , Macrófagos/patologia , Redes e Vias Metabólicas/genética , Síndrome Metabólica/genética , Síndrome Metabólica/metabolismo , Síndrome Metabólica/patologia , Microcirculação/genética , Obesidade/genética , Obesidade/metabolismo , Obesidade/patologia , Organogênese/genética , Comunicação Parácrina/genéticaRESUMO
Obesity and related diseases are a major cause of human morbidity and mortality and constitute a substantial economic burden for society. Effective treatment regimens are scarce, and new therapeutic targets are needed. Brown adipose tissue, an energy-expending tissue that produces heat, represents a potential therapeutic target. Its presence is associated with low body mass index, low total adipose tissue content and a lower risk of type 2 diabetes mellitus. Knowledge about the development and function of thermogenic adipocytes in brown adipose tissue has increased substantially in the last decade. Important transcriptional regulators have been identified, and hormones able to modulate the thermogenic capacity of the tissue have been recognized. Intriguingly, it is now clear that humans, like rodents, possess two types of thermogenic adipocytes: the classical brown adipocytes found in the interscapular brown adipose organ and the so-called beige adipocytes primarily found in subcutaneous white adipose tissue after adrenergic stimulation. The presence of two distinct types of energy-expending adipocytes in humans is conceptually important because these cells might be stimulated and recruited by different signals, raising the possibility that they might be separate potential targets for therapeutic intervention. In this review, we will discuss important features of the energy-expending brown adipose tissue and highlight those that may serve as potential targets for pharmacological intervention aimed at expanding the tissue and/or enhancing its function to counteract obesity.
Assuntos
Tecido Adiposo Marrom/fisiologia , Obesidade/fisiopatologia , Obesidade/terapia , Adipócitos/classificação , Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/metabolismo , Animais , Metabolismo Energético , Hormônios/fisiologia , Humanos , Gordura Subcutânea/citologia , TermogêneseRESUMO
Adipose tissue is not to be treated as a homogenous organ of identical functionality. Adipose tissue can be divided into specific regions of different localizations with adipocytes differing in their genetical profile, metabolism, autophagic activity and capacity for multiplication - hyperplasia. Visceral and ectopic regions of adipose tissue are characterized by poor capilarization, hypoxia, and the presence of hypertrophic big adipocytes. Adipocytes of these regions show limited inherent capacity for hyperplasia and when exposed for over nutrition are undergoing disruption with consecutive autophagy and macrophage infiltration leading to development of inflammatory conditions as well as increased fibrosis and remodeling of extracellular matrix. Comparatively smaller numerous adipocytes of gluteo-femoral regions are characterized by better insulin sensitivity and ability to buffer the excess of fatty acids preventing lipotoxemia and to react by hyperplasia when exposed to calorie excess. The differences between these two types of adipocytes with different genetic profile and metabolism are parallel with different localization of these two types of adipocytes and are responsible for the difference in pathophysiology between abdominal and gluteofemoral adiposity. The large body of evidence indicates that hypertrophic and hyperplastic obesity correspond to abdominal and gluteophemoral type of obesity and explain the differences in their pathophysiology and comorbidities.
Assuntos
Adipócitos/classificação , Tecido Adiposo/metabolismo , Obesidade/classificação , Obesidade/metabolismo , Adipócitos/metabolismo , Tecido Adiposo/patologia , Ácidos Graxos/metabolismo , Fibrose , Humanos , Hiperplasia , Resistência à Insulina , Substâncias Protetoras/metabolismoRESUMO
Adipocyte progenitor cells (APCs) provide the reservoir of regenerative cells to produce new adipocytes, although their identity in humans remains elusive. Using FACS analysis, gene expression profiling, and metabolic and proteomic analyses, we identified three APC subtypes in human white adipose tissues. The APC subtypes are molecularly distinct but possess similar proliferative and adipogenic capacities. Adipocytes derived from APCs with high CD34 expression exhibit exceedingly high rates of lipid flux compared with APCs with low or no CD34 expression, while adipocytes produced from CD34- APCs display beige-like adipocyte properties and a unique endocrine profile. APCs were more abundant in gluteofemoral compared with abdominal subcutaneous and omental adipose tissues, and the distribution of APC subtypes varies between depots and in patients with type 2 diabetes. These findings provide a mechanistic explanation for the heterogeneity of human white adipose tissue and a potential basis for dysregulated adipocyte function in type 2 diabetes.
Assuntos
Gordura Abdominal/citologia , Adipócitos/metabolismo , Diabetes Mellitus Tipo 2/patologia , Células-Tronco Mesenquimais/metabolismo , Gordura Subcutânea/citologia , Gordura Abdominal/patologia , Adipócitos/classificação , Adipócitos/fisiologia , Adiposidade , Adulto , Animais , Antígenos CD34/genética , Antígenos CD34/metabolismo , Proliferação de Células , Células Cultivadas , Feminino , Humanos , Masculino , Células-Tronco Mesenquimais/classificação , Células-Tronco Mesenquimais/fisiologia , Camundongos , Camundongos SCID , Pessoa de Meia-Idade , Proteoma , Gordura Subcutânea/patologia , TranscriptomaRESUMO
Evidence from preclinical research and clinical trials demonstrates the use of the stromal vascular fraction (SVF) as therapy for numerous indications. These results demonstrate that autologous SVF is not only safe and effective but provides robust anti-inflammatory, immunomodulatory, and reparative effects in vivo. The potency of the SVF is attributed to the cellular composition which includes adipose-derived stem cells (ASCs), adipocytes, endothelial cells, and various immune cells. As the name would suggest, these SVF cells are derived from the stromal compartment of adipose, or fat. Once digested, the cells that constitute adipose are released and collected as the SVF. The cellular frequencies within the SVF can then be assessed using a fluorescent antibody-based technique known as flow cytometry. The following chapter provides a standard operating protocol that describes the procedures from harvesting the fat tissue from experimental mice to isolating and characterizing the SVF.
Assuntos
Tecido Adiposo Branco/citologia , Fracionamento Celular , Separação Celular , Adipócitos/classificação , Animais , Biomarcadores/análise , Células Endoteliais/classificação , Citometria de Fluxo , Imunofluorescência , Humanos , Imunofenotipagem , Células-Tronco Mesenquimais/classificação , Camundongos , Camundongos Endogâmicos C57BLRESUMO
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.
Assuntos
Tecido Adiposo/patologia , Obesidade/patologia , Adipócitos/classificação , Adipócitos/patologia , Adipogenia , Tecido Adiposo/irrigação sanguínea , Tecido Adiposo/imunologia , Tecido Adiposo/inervação , Animais , Células Endoteliais/patologia , Metabolismo Energético , Feminino , Humanos , Lipólise , Macrófagos/classificação , Macrófagos/patologia , Masculino , Camundongos , Miócitos de Músculo Liso/patologia , Neurônios/fisiologia , Obesidade/epidemiologia , Obesidade/genética , Caracteres SexuaisRESUMO
Cold temperatures induce formation of beige adipocytes, which convert glucose and fatty acids to heat, and may increase energy expenditure, reduce adiposity and lower blood glucose. This therapeutic potential is unrealized, hindered by a dearth of genetic tools to fate map, track and manipulate beige progenitors and 'beiging'. Here we examined 12 Cre/inducible Cre mouse strains that mark adipocyte, muscle and mural lineages, three proposed beige origins. Among these mouse strains, only those that marked perivascular mural cells tracked the cold-induced beige lineage. Two SMA-based strains, SMA-Cre(ERT2) and SMA-rtTA, fate mapped into the majority of cold-induced beige adipocytes and SMA-marked progenitors appeared essential for beiging. Disruption of the potential of the SMA-tracked progenitors to form beige adipocytes was accompanied by an inability to maintain body temperature and by hyperglycaemia. Thus, SMA-engineered mice may be useful to track and manipulate beige progenitors, beige adipocyte formation and function.
Assuntos
Adipócitos/classificação , Adipócitos/metabolismo , Temperatura Baixa , Animais , Vasos Sanguíneos/citologia , Vasos Sanguíneos/metabolismo , Células Cultivadas , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Camundongos , Camundongos Endogâmicos , Músculo Esquelético/citologia , Músculo Esquelético/metabolismoRESUMO
Adipose-derived stem cells (AdSCs) have recently been shown to differentiate into cardiovascular lineage cells. However, little is known about the fat tissue origin-dependent differences in AdSC function and differentiation potential. AdSC-rich cells were isolated from subcutaneous, visceral, cardiac (CA), and subscapular adipose tissue from mice and their characteristics analyzed. After four different AdSC types were cultured with specific differentiation medium, immunocytochemical analysis was performed for the assessment of differentiation into cardiovascular cells. We then examined the in vitro differentiation capacity and therapeutic potential of AdSCs in ischemic myocardium using a mouse myocardial infarction model. The cell density and proliferation activity of CA-derived AdSCs were significantly increased compared with the other adipose tissue-derived AdSCs. Immunocytochemistry showed that CA-derived AdSCs had the highest appearance rates of markers for endothelial cells, vascular smooth muscle cells, and cardiomyocytes among the AdSCs. Systemic transfusion of CA-derived AdSCs exhibited the highest cardiac functional recovery after myocardial infarction and the high frequency of the recruitment to ischemic myocardium. Moreover, long-term follow-up of the recruited CA-derived AdSCs frequently expressed cardiovascular cell markers compared with the other adipose tissue-derived AdSCs. Cardiac adipose tissue could be an ideal source for isolation of therapeutically effective AdSCs for cardiac regeneration in ischemic heart diseases. Significance: The present study found that cardiac adipose-derived stem cells have a high potential to differentiate into cardiovascular lineage cells (i.e., cardiomyocytes, endothelial cells, and vascular smooth muscle cells) compared with stem cells derived from other adipose tissue such as subcutaneous, visceral, and subscapular adipose tissue. Notably, only a small number of supracardiac adipose-derived stem cells that were systemically transplanted sufficiently improved cardiac functional recovery after myocardial infarction, differentiating into cardiovascular cells in the ischemic myocardium. These findings suggest a new autologous stem cell therapy for patients with myocardial ischemia, especially those with secondary myocardial ischemia after cardiovascular open chest surgery.
Assuntos
Adipócitos/citologia , Infarto do Miocárdio/terapia , Miocárdio/citologia , Miócitos Cardíacos/citologia , Transplante de Células-Tronco , Células-Tronco/citologia , Gordura Abdominal/citologia , Gordura Abdominal/metabolismo , Adipócitos/classificação , Adipócitos/metabolismo , Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/metabolismo , Animais , Biomarcadores/metabolismo , Procedimentos Cirúrgicos Cardíacos , Contagem de Células , Diferenciação Celular , Separação Celular , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Especificidade de Órgãos , Células-Tronco/metabolismo , Gordura Subcutânea/citologia , Gordura Subcutânea/metabolismo , Transplante AutólogoRESUMO
Inflammatory signaling may play a role in high-fat diet (HFD)-related circadian clock disturbances that contribute to systemic metabolic dysregulation. Therefore, palmitate, the prevalent proinflammatory saturated fatty acid (SFA) in HFD and the anti-inflammatory, poly-unsaturated fatty acid (PUFA), docosahexaenoic acid (DHA), were analyzed for effects on circadian timekeeping and inflammatory responses in peripheral clocks. Prolonged palmitate, but not DHA, exposure increased the period of fibroblast Bmal1-dLuc rhythms. Acute palmitate treatment produced phase shifts of the Bmal1-dLuc rhythm that were larger in amplitude as compared to DHA. These phase-shifting effects were time-dependent and contemporaneous with rhythmic changes in palmitate-induced inflammatory responses. Fibroblast and differentiated adipocyte clocks exhibited cell-specific differences in the time-dependent nature of palmitate-induced shifts and inflammation. DHA and other inhibitors of inflammatory signaling (AICAR, cardamonin) repressed palmitate-induced proinflammatory responses and phase shifts of the fibroblast clock, suggesting that SFA-mediated inflammatory signaling may feed back to modulate circadian timekeeping in peripheral clocks.
Assuntos
Relógios Circadianos/efeitos dos fármacos , Ácidos Graxos Insaturados/farmacologia , Ácidos Graxos/farmacologia , Interleucina-6/genética , NF-kappa B/metabolismo , Adipócitos/classificação , Adipócitos/efeitos dos fármacos , Adipócitos/imunologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Ritmo Circadiano/efeitos dos fármacos , Ácidos Docosa-Hexaenoicos/farmacologia , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/imunologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Ácido Palmítico/farmacologia , Fosforilação , Transdução de Sinais/efeitos dos fármacosRESUMO
BACKGROUND AND OBJECTIVES: We previously found that human fetal lung is a rich source of mesenchymal stem cells (MSC). Here we characterize and analyze the frequency and function of MSC in other second-trimester fetal tissues. DESIGN AND METHODS: Single cell suspensions of fetal bone marrow (BM), liver, lung, and spleen were made and analyzed by flow cytometry for the expression of CD90, CD105, CD166, SH3, SH4, HLA-ABC, HLA-DR, CD34 and CD45. We assessed the frequency of MSC by limiting dilution assay. RESULTS: The frequency of MSC in BM was significantly higher than in liver, lung, and spleen (p<0.05). On primary non-expanded cells from fetal liver, lung and spleen the number of cells positive for mesenchymal markers was significantly higher within the CD34 positive population than within the CD34 negative population. The phenotype of the culture-expanded MSC was similar for all fetal tissues, i.e. CD90, CD105, CD166, SH3, SH4 and HLA-ABC positive and CD34, CD45 and HLA-DR negative. Culture-expanded cells from all tissues were able to differentiate along adipogenic and osteogenic pathways. However, adipogenic differentiation was less in MSC derived from spleen, and osteogenic differentiation was reduced in liver-derived MSC (p<0.05). INTERPRETATION AND CONCLUSIONS: Our results indicate that culture-expanded MSC derived from second-trimester fetal tissues, although phenotypically similar, exhibit heterogeneity in differentiating potential. We speculate that these differences may be relevant for the clinical application of MSC.
Assuntos
Células da Medula Óssea/citologia , Diferenciação Celular/fisiologia , Imunofenotipagem , Fígado/citologia , Pulmão/citologia , Mesoderma/citologia , Células-Tronco Multipotentes/citologia , Baço/citologia , Aborto Legal , Adipócitos/química , Adipócitos/classificação , Adipócitos/citologia , Adipócitos/metabolismo , Antígenos CD34/análise , Antígenos CD34/imunologia , Células Cultivadas , Feminino , Feto/citologia , Granulócitos/química , Granulócitos/citologia , Granulócitos/metabolismo , Humanos , Imunofenotipagem/métodos , Fígado/embriologia , Pulmão/embriologia , Linfócitos/química , Linfócitos/citologia , Linfócitos/metabolismo , Mesoderma/classificação , Monócitos/química , Monócitos/citologia , Monócitos/metabolismo , Células-Tronco Multipotentes/classificação , Osteócitos/química , Osteócitos/classificação , Osteócitos/citologia , Osteócitos/metabolismo , Gravidez , Segundo Trimestre da Gravidez , Baço/embriologiaRESUMO
Several methods are available for estimating size distributions of spherical objects in tissue sections. In this article a comparative study of four stereological techniques applied to human bone marrow adipocytes was carried out. In the first part, four stereological methods (Giger-Riedwyl, Saltykov, Wicksell, and Cruz-Orive) were used for the evaluation of adipocyte size in a set of 50 human bone marrow specimens (20 normal controls, 10 aplastic, 10 hyperplastic and 10 dysplastic bone marrows). In the second part, a computer simulation model was employed for generating both control and test populations. The latter were analyzed by means of the four stereological methods and compared to the control. When applied to bone marrow specimens, no statistically significant differences were seen among the four methods. Results were very close between the Giger-Riedwyl and Saltykov methods, and between the Wicksell and Cruz-Orive methods. In the simulation model, Saltykov's method was the most accurate stereological technique for the studied conditions. Additional advantages of this method are that the assumption of Gaussian distribution is not required, and that a higher relative weight is assigned to the largest classes, in which accurate definition is easier in the microphotographs. However, since the differences among the four methods are very small, they may all be considered as valid for the stereological study of human bone marrow adipocytes.