The visceral adipose tissue bacterial microbiota provides a signature of obesity based on inferred metagenomic functions.

Background: Metabolic inflammation mediated obesity requires bacterial molecules to trigger immune and adipose cells leading to inflammation and adipose depot development. In addition to the well-established gut microbiota dysbiosis, a leaky gut has been identified in patients with obesity and animal models, characterized by the presence of a tissue microbiota in the adipose fat pads.

Methods: To determine its potential role, we sequenced the bacterial 16 S rRNA genes in the visceral adipose depot of patients with obesity.

Endothelial DLL4 Is an Adipose Depot-Specific Fasting Sensor Regulating Fatty Acid Fluxes.

Background: Adaptation of fat depots to change in fuel availability is critical for metabolic flexibility and cardiometabolic health. The mechanisms responsible for fat depot-specific lipid sensing and shuttling remain elusive. Adipose tissue microvascular endothelial cells (AT-EC) regulates bidirectional fatty acid fluxes depending on fed or fasted state.

Notch activation shifts the fate decision of senescent progenitors toward myofibrogenesis in human adipose tissue.

Senescence is a key event in the impairment of adipose tissue (AT) function with obesity and aging but the underlying molecular and cellular players remain to be fully defined, particularly with respect to the human AT progenitors. We have found distinct profiles of senescent progenitors based on AT location between stroma from visceral versus subcutaneous AT. In addition to flow cytometry, we characterized the location differences with transcriptomic and proteomic approaches, uncovering the genes and developmental pathways that are underlying replicative senescence.

Subcutaneous Stromal Cells and Visceral Adipocyte Size Are Determinants of Metabolic Flexibility in Obesity and in Response to Weight Loss Surgery.

Adipose tissue (AT) expansion either through hypertrophy or hyperplasia is determinant in the link between obesity and metabolic alteration. The present study aims to profile the unhealthy subcutaneous and visceral AT (SAT, VAT) expansion in obesity and in the outcomes of bariatric surgery (BS). The repartition of adipocytes according to diameter and the numbers of progenitor subtypes and immune cells of SAT and VAT from 161 obese patients were determined by cell imaging and flow cytometry, respectively.

The Sexual Dimorphism of Human Adipose Depots.

The amount and the distribution of body fat exhibit trajectories that are sex- and human species-specific and both are determinants for health. The enhanced accumulation of fat in the truncal part of the body as a risk factor for cardiovascular and metabolic diseases is well supported by epidemiological studies. In addition, a possible independent protective role of the gluteofemoral fat compartment and of the brown adipose tissue is emerging.

Periprostatic Adipose Tissue Displays a Chronic Hypoxic State that Limits Its Expandability.

White adipose tissue accumulates at various sites throughout the body, some adipose tissue depots exist near organs whose function they influence in a paracrine manner. Prostate gland is surrounded by a poorly characterized adipose depot called periprostatic adipose tissue (PPAT), which plays emerging roles in prostate-related disorders. Unlike all other adipose depots, PPAT secretes proinflammatory cytokines even in lean individuals and does not increase in volume during obesity.

The Impact of Long-term Physical Inactivity on Adipose Tissue Immunometabolism.

Context: Adipose tissue and physical inactivity both influence metabolic health and systemic inflammation, but how adipose tissue responds to chronic physical inactivity is unknown.

Objective: This work aimed to characterize the impact of chronic physical inactivity on adipose tissue in healthy, young males.

Methods: We collected subcutaneous adipose tissue from 20 healthy, young men before and after 60 days of complete bed rest with energy intake reduced to maintain energy balance and fat mass.

Expression of the Adipocyte Progenitor Markers MSCA1 and CD36 is Associated With Adipose Tissue Function in Children.

Context: MSCA1 (mesenchymal stem cell antigen 1) and CD36 (cluster of differentiation 36) have been described as novel adipocyte progenitor markers in adults with a potential relevance for obesity and adipocyte progenitor function.

Objective: With the early manifestation of obesity in children and formation of adipose tissue (AT) dysfunction, children provide the opportunity to characterize the function of MSCA1 and CD36 during physiological AT accumulation and with obesity and related disease.

Methods: We investigated MSCA1 and CD36 expression in adipocytes and stroma vascular fraction (SVF) cells from 133 children of the Leipzig AT Childhood cohort with regard to AT accumulation and biology.

Coordinating Effect of VEGFC and Oleic Acid Participates to Tumor Lymphangiogenesis.

In cancer, the lymphatic system is hijacked by tumor cells that escape from primary tumor and metastasize to the sentinel lymph nodes. Tumor lymphangiogenesis is stimulated by the vascular endothelial growth factors-C (VEGFC) after binding to its receptor VEGFR-3. However, how VEGFC cooperates with other molecules to promote lymphatics growth has not been fully determined.

Divergent immunometabolic changes in adipose tissue and skeletal muscle with ageing in healthy humans.

Key Points: Ageing is associated with increased systemic inflammation and metabolic dysfunction that contributes to the development of age-associated diseases. The role of adipose tissue in immunometabolic alterations that take place with ageing is unknown in humans. We show, in healthy, active and lean older adults, that adipose tissue, but not skeletal muscle, displays considerable pro-inflammatory transcriptomic, cellular and secretory changes, as well as a reduction in insulin signalling proteins compared to younger adults.

Obesity of mice lacking VAP-1/SSAO by Aoc3 gene deletion is reproduced in mice expressing a mutated vascular adhesion protein-1 (VAP-1) devoid of amine oxidase activity.

The product of Aoc3 gene is known as vascular adhesion protein-1 (VAP-1), a glycoprotein contributing to leukocyte extravasation and exhibiting semicarbazide-sensitive amine oxidase activity (SSAO). Regarding the immune functions of VAP-1/SSAO, it is known that mice bearing Aoc3 gene knock-out (AOC3KO) exhibit defects in leukocyte migration similar to those of mice expressing a mutated VAP-1 lacking functional SSAO activity (knock-in, AOC3KI). However, it has not been reported whether these models differ regarding other disturbances.

Growth and differentiation factor 15 is secreted by skeletal muscle during exercise and promotes lipolysis in humans.

We hypothesized that skeletal muscle contraction produces a cellular stress signal, triggering adipose tissue lipolysis to sustain fuel availability during exercise. The present study aimed at identifying exercise-regulated myokines, also known as exerkines, able to promote lipolysis. Human primary myotubes from lean healthy volunteers were submitted to electrical pulse stimulation (EPS) to mimic either acute intense or chronic moderate exercise.

Effects of the amino acid derivatives, β-hydroxy-β-methylbutyrate, taurine, and N-methyltyramine, on triacylglycerol breakdown in fat cells.

Various amino acid (AA) metabolites are used as supplements to facilitate metabolic control and enhance responsiveness of insulin-sensitive tissues. β-hydroxy-β-methylbutyrate (HMB) is a leucine metabolite proposed to prevent muscle wasting and to mitigate insulin resistance. Taurine, commonly added to energizing drinks, is a metabolite of methionine and cysteine present in bile juice, and proposed to be involved in lipid digestion and to be pro-lipolytic in adipocytes.

Senescence Alters PPARγ (Peroxisome Proliferator-Activated Receptor Gamma)-Dependent Fatty Acid Handling in Human Adipose Tissue Microvascular Endothelial Cells and Favors Inflammation.

Objective: Adipose tissue (AT) dysfunction associated with obesity or aging is a major cause for lipid redistribution and the progression of cardiometabolic disorders. Our goal is to decipher the contribution of human AT microvascular endothelial cells (ECs) in the maintenance of fatty acid (FA) fluxes and the impact of senescence on their function.

Approach And Results: We used freshly isolated primary microvascular ECs from human AT.

Analysis of Lipolysis in Human Subcutaneous Adipose Tissue Explants.

Most studies of human adipose tissue (AT) metabolism and functionality have been performed on isolated mature adipocyte or using the microdialysis technique (Lafontan, 2012). However, these approaches have several limitations. The use of mature isolated adipocytes is limiting as adipocytes are not in their physiological environment and the collagenase digestion process could affect both adipocyte survival and functionality.

CD36 Is a Marker of Human Adipocyte Progenitors with Pronounced Adipogenic and Triglyceride Accumulation Potential.

White adipose tissue (WAT) expands in part through adipogenesis, a process involving fat cell generation and fatty acid (FA) storage into triglycerides (TGs). Several findings suggest that inter-individual and regional variations in adipogenesis are linked to metabolic complications. We aimed to identify cellular markers that define human adipocyte progenitors (APs) with pronounced adipogenic/TG storage ability.

Notch, lipids, and endothelial cells.

Purpose Of Review: Notch signaling is an evolutionary conserved pathway critical for cardiovascular development and angiogenesis. More recently, the contribution of Notch signaling to the homeostasis of the adult vasculature has emerged as an important novel paradigm, but much remains to be understood.

Recent Findings: Recent findings shed light on the impact of Notch in vascular and immune responses to microenvironmental signals as well as on the onset of atherosclerosis.

Multiple Functions of MSCA-1/TNAP in Adult Mesenchymal Progenitor/Stromal Cells.

Our knowledge about mesenchymal stem cells has considerably grown in the last years. Since the proof of concept of the existence of such cells in the 70s by Friedenstein et al., a growing mass of reports were conducted for a better definition of these cells and for the reevaluation from the term "mesenchymal stem cells" to the term "mesenchymal stromal cells (MSCs).

The size of the primary cilium and acetylated tubulin are modulated during adipocyte differentiation: Analysis of HDAC6 functions in these processes.

The primary cilium is an organelle present in most of the cells of the organism. Ciliopathies, such as the Bardet Biedl and the Alstrom syndromes are associated with obesity. We, and others, have shown that the primary cilium undergoes size modifications during adipocyte differentiation of human adipose stromal cells.

Inflammation and the depot-specific secretome of human preadipocytes.

Objective: Visceral white adipose tissue (WAT) expansion and macrophage accumulation are associated with metabolic dysfunction. Visceral WAT typically shows greater macrophage infiltration. Preadipocytes show varying proinflammatory expression profiles among WAT depots.

IER3 Promotes Expansion of Adipose Progenitor Cells in Response to Changes in Distinct Microenvironmental Effectors.

Adipose tissue expansion is well-orchestrated to fulfill the energy demand. It results from adipocyte hypertrophy and hyperplasia due to adipose progenitor cell (APC) expansion and differentiation. Chronic low grade inflammation and hypoxia take place in obese adipose tissue microenvironment.

Interrelationship between lymphocytes and leptin in fat depots of obese mice revealed by changes in nutritional status.

The mechanisms underlying the relationships between nutritional status and immunity remain to be fully characterized. The present study was undertaken to analyze by flow cytometry, in the context of diet-induced obesity, the status of immune cells in subcutaneous, and epididymal fat depots in wild-type and immunodeficient Rag2-/- mice submitted to nutritional challenge, i.e.

Human white and brite adipogenesis is supported by MSCA1 and is impaired by immune cells.

Obesity-associated inflammation contributes to the development of metabolic diseases. Although brite adipocytes have been shown to ameliorate metabolic parameters in rodents, their origin and differentiation remain to be characterized in humans. Native CD45-/CD34+/CD31- cells have been previously described as human adipocyte progenitors.