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Methods in Molecular Biology (Clifton,... 2019Adipose tissue regulates metabolic homeostasis by acting as an endocrine organ and energy reservoir. Adipose tissue development and functional maintenance are dependent...
Adipose tissue regulates metabolic homeostasis by acting as an endocrine organ and energy reservoir. Adipose tissue development and functional maintenance are dependent on adipocyte differentiation, in which autophagy plays an important role. It has been shown that autophagy deficiency dampens adipocyte differentiation, compromises adipose tissue development, dysregulates adipocytokine secretion, and even causes sudden death in young animals. Therefore, accurate assessment of autophagy in adipocyte is critical for the study of adipose biology or pathology of metabolic diseases. In this chapter, we described the procedure of autophagy analysis during adipocyte differentiation, and discussed the power of steady-state autophagy protein (e.g., beclin 1, LC3, and p62) levels versus autophagy flux to reflect autophagy activity.
Topics: 3T3-L1 Cells; Adipocytes; Adipokines; Adipose Tissue; Animals; Autophagy; Autophagy-Related Proteins; Cell Differentiation; Cells, Cultured; Mice
PubMed: 28815517
DOI: 10.1007/7651_2017_65 -
The Biochemical Journal Jun 2020Metabolic inflexibility, defined as the inability to respond or adapt to metabolic demand, is now recognised as a driving factor behind many pathologies associated with... (Review)
Review
Metabolic inflexibility, defined as the inability to respond or adapt to metabolic demand, is now recognised as a driving factor behind many pathologies associated with obesity and the metabolic syndrome. Adipose tissue plays a pivotal role in the ability of an organism to sense, adapt to and counteract environmental changes. It provides a buffer in times of nutrient excess, a fuel reserve during starvation and the ability to resist cold-stress through non-shivering thermogenesis. Recent advances in single-cell RNA sequencing combined with lineage tracing, transcriptomic and proteomic analyses have identified novel adipocyte progenitors that give rise to specialised adipocytes with diverse functions, some of which have the potential to be exploited therapeutically. This review will highlight the common and distinct functions of well-known adipocyte populations with respect to their lineage and plasticity, as well as introducing the most recent members of the adipocyte family and their roles in whole organism energy homeostasis. Finally, this article will outline some of the more preliminary findings from large data sets generated by single-cell transcriptomics of mouse and human adipose tissue and their implications for the field, both for discovery and for therapy.
Topics: Adipocytes; Adipose Tissue, Brown; Animals; Humans; Mice; Thermogenesis
PubMed: 32539124
DOI: 10.1042/BCJ20200298 -
Cells Nov 2019Cellular plasticity is a transformation of a terminally differentiated cell into another cell type, which has been long known to occur in disease and regeneration.... (Review)
Review
Cellular plasticity is a transformation of a terminally differentiated cell into another cell type, which has been long known to occur in disease and regeneration. However, white adipocytes (fat cells) have only recently been observed to undergo different types of cellular plasticity. Adipocyte transdifferentiation into myofibroblasts and cancer-associated fibroblasts occurs in fibrosis and cancer, respectively. On the other hand, reversible adipocyte dedifferentiation into adipocyte progenitor cells (preadipocytes) has been demonstrated in mammary gland and in dermal adipose tissue. Here we discuss the research on adipocyte plasticity, including the experimental approaches that allowed to detect and study it, the current state of the knowledge, major research questions which remain to be addressed, and the advances required to stimulate adipocyte plasticity research. In the future, the knowledge of the molecular mechanisms of adipocyte plasticity can be utilized both to prevent adipocyte plasticity in disease and to stimulate it for use in regenerative medicine.
Topics: Adipocytes, White; Adipogenesis; Adipose Tissue, White; Cell Plasticity; Cellular Reprogramming; Humans
PubMed: 31775295
DOI: 10.3390/cells8121507 -
Clinical Calcium 2017Adipose tissues are the major organ that controls systemic energy metabolism and maintain homeostasis by storing lipids, dissipating them as heat, and producing various... (Review)
Review
Adipose tissues are the major organ that controls systemic energy metabolism and maintain homeostasis by storing lipids, dissipating them as heat, and producing various adipokines. There are two major classes of adipocytes: white and brown adipocytes. White adipocytes store and release lipids, while brown adipocytes burn substrates to produce heat. In addition to classical brown adipose tissues consisting of brown adipocytes, cold exposure and β3 stimulation induce development of brown cell-like "beige" adipocytes in white adipose tissues. There appear to be multiple adipocyte progenitor cell populations of different developmental origins. In this article, we overview white and brown/beige adipocyte differentiation in development and obesity. Adipocytes differentiate in complex interplays with various stromal cells, including vascular, immune and neuronal cells. Elucidation of the cellular interplays would lead to identification of novel therapeutic targets for obesity and metabolic syndrome.
Topics: Adipocytes, Brown; Adipocytes, White; Animals; Cell Communication; Cell Differentiation; Humans; Stem Cells
PubMed: 28536316
DOI: No ID Found -
Clinical Interventions in Aging 2017Age-dependent modification of the facial subcutaneous white adipose tissue (sWAT) connected with reduction of its volume, modification of collagen content and adhesion... (Review)
Review
Age-dependent modification of the facial subcutaneous white adipose tissue (sWAT) connected with reduction of its volume, modification of collagen content and adhesion between dermal and adipose layers can significantly influence mechanical stability of the skin and cause the development of aging symptoms such as wrinkles. Typical aging appearance in facial skin is at least partly connected with special phenotypical features of facial preadipocytes and mature adipocytes. In this paper, we have discussed the possible roles of local inflammation, compartmental structure of facial sWAT and trans-differentiation processes such as beiging of white adipocytes and adipocyte-myofibroblast transition in facial skin aging.
Topics: Adipocytes; Adipose Tissue; Adipose Tissue, White; Face; Humans; Phenotype; Skin Aging
PubMed: 29255352
DOI: 10.2147/CIA.S151599 -
Obesity Reviews : An Official Journal... Mar 2018Adipose tissue plays a significant role in whole body energy homeostasis. Obesity-associated diabetes, fatty liver and metabolic syndrome are closely linked to adipose... (Review)
Review
Adipose tissue plays a significant role in whole body energy homeostasis. Obesity-associated diabetes, fatty liver and metabolic syndrome are closely linked to adipose stress and dysfunction. Genetic predisposition, overeating and physical inactivity influence the expansion of adipose tissues. Under conditions of constant energy surplus, adipocytes become hypertrophic and adipose tissues undergo hyperplasia so as to increase their lipid storage capacity, thereby keeping circulating blood glucose and fatty acids below toxic levels. Nonetheless, adipocytes have a saturation point where they lose capacity to store more lipids. At this stage, when adipocytes are fully lipid-engorged, they express stress signals. Adipose depots (particularly visceral compartments) from obese individuals with a severe metabolic phenotype are characterized by the high proportion of hypertrophic adipocytes. This review focuses on the mechanisms of adipocyte enlargement in relation to adipose fatty acid and cholesterol metabolism, and considers how this may be related to adipose dysfunction.
Topics: Adipocytes; Adiposity; Fatty Acids; Humans; Inflammation Mediators; Lipid Metabolism; Obesity; Overnutrition; Stress, Physiological
PubMed: 29243339
DOI: 10.1111/obr.12646 -
Annals of Plastic Surgery Mar 2015Although lipotransfer, or fat grafting, is a commonly used procedure in aesthetic and reconstructive surgery, there is still variability in graft survival and... (Review)
Review
Although lipotransfer, or fat grafting, is a commonly used procedure in aesthetic and reconstructive surgery, there is still variability in graft survival and neoadipogenesis from one procedure to the next. A better understanding of the sequential molecular events occurring with grafting would allow us to strategize methods to improve the regenerative potency of the grafted tissue. These steps begin with an autophagic process, followed by the inclusion of stromal vascular fraction and matrix components. By tailoring and modifying each of these steps for a particular type of aesthetic or reconstructive procedure, strategic sequencing represents a dynamic approach to lipotransfer with the aim of maximizing adipocyte viability and growth. In the implementation of the strategic sequence, it remains important to consider the clinical viability of each step and its compliance with the US Food and Drug Administration regulations. This review highlights the basic science behind clinically translatable approaches to supplementing various fat grafting procedures.
Topics: Adipocytes; Adipose Tissue; Autophagy; Cosmetic Techniques; Graft Survival; Humans; Plastic Surgery Procedures; Stem Cell Transplantation; Tissue Scaffolds; Transplantation, Autologous
PubMed: 25643185
DOI: 10.1097/SAP.0000000000000416 -
Trends in Cell Biology May 2016The global incidence of obesity and its comorbidities continues to rise along with a demand for novel therapeutic interventions. Brown adipose tissue (BAT) is attracting... (Review)
Review
The global incidence of obesity and its comorbidities continues to rise along with a demand for novel therapeutic interventions. Brown adipose tissue (BAT) is attracting attention as a therapeutic target because of its presence in adult humans and high capacity to dissipate energy as heat, and thus burn excess calories, when stimulated. Another potential avenue for therapeutic intervention is to induce, within white adipose tissue (WAT), the formation of brown-like adipocytes called brite (brown-like-in-white) or beige adipocytes. However, understanding how to harness the potential of these thermogenic cells requires a deep understanding of their developmental origins and regulation. Recent cell-labeling and lineage-tracing experiments are beginning to shed light on this emerging area of adipocyte biology. We review here adipocyte development, giving particular attention to thermogenic adipocytes.
Topics: Adipocytes; Adipose Tissue; Animals; Cell Lineage; Humans; Models, Biological; Organ Specificity; Stem Cells
PubMed: 26874575
DOI: 10.1016/j.tcb.2016.01.004 -
Nature Microbiology Nov 2023Trypanosoma brucei causes African trypanosomiasis, colonizing adipose tissue and inducing weight loss. Here we investigated the molecular mechanisms responsible for...
Trypanosoma brucei causes African trypanosomiasis, colonizing adipose tissue and inducing weight loss. Here we investigated the molecular mechanisms responsible for adipose mass loss and its impact on disease pathology. We found that lipolysis is activated early in infection. Mice lacking B and T lymphocytes fail to upregulate adipocyte lipolysis, resulting in higher fat mass retention. Genetic ablation of the rate-limiting adipose triglyceride lipase specifically from adipocytes (Adipoq-Atgl) prevented the stimulation of adipocyte lipolysis during infection, reducing fat mass loss. Surprisingly, these mice succumbed earlier and presented a higher parasite burden in the gonadal adipose tissue, indicating that host lipolysis limits parasite growth. Consistently, free fatty acids comparable with those of adipose interstitial fluid induced loss of parasite viability. Adipocyte lipolysis emerges as a mechanism controlling local parasite burden and affecting the loss of fat mass in African trypanosomiasis.
Topics: Animals; Mice; Lipolysis; Trypanosoma brucei brucei; Trypanosomiasis, African; Lipase; Adipocytes; Obesity
PubMed: 37828246
DOI: 10.1038/s41564-023-01496-7 -
Frontiers in Endocrinology 2022When compared to adipocytes in other anatomical sites, the interaction of bone marrow resident adipocytes with the other cells in their microenvironment is less well... (Review)
Review
When compared to adipocytes in other anatomical sites, the interaction of bone marrow resident adipocytes with the other cells in their microenvironment is less well understood. Bone marrow adipocytes originate from a resident, self-renewing population of multipotent bone marrow stromal cells which can also give rise to other lineages such as osteoblasts. The differentiation fate of these mesenchymal progenitors can be influenced to favour adipogenesis by several factors, including the administration of thiazolidinediones and increased age. Experimental data suggests that increases in bone marrow adipose tissue volume may make bone both more attractive to metastasis and conducive to cancer cell growth. Bone marrow adipocytes are known to secrete a variety of lipids, cytokines and bioactive signaling molecules known as adipokines, which have been implicated as mediators of the interaction between adipocytes and cancer cells. Recent studies have provided new insight into the impact of bone marrow adipose tissue volume expansion in regard to supporting and exacerbating the effects of bone metastasis from solid tumors, focusing on prostate, breast and lung cancer and blood cancers, focusing on multiple myeloma. In this mini-review, recent research developments pertaining to the role of factors which increase bone marrow adipose tissue volume, as well as the role of adipocyte secreted factors, in the progression of bone metastatic prostate and breast cancer are assessed. In particular, recent findings regarding the complex cross-talk between adipocytes and metastatic cells of both lung and prostate cancer are highlighted.
Topics: Adipocytes; Adipogenesis; Bone Marrow Cells; Cell Communication; Humans; Male; Neoplasms; Tumor Microenvironment
PubMed: 35903271
DOI: 10.3389/fendo.2022.903925