scholarly journals Impact of Bariatric Surgery on Adipose Tissue Biology

2021 ◽  
Vol 10 (23) ◽  
pp. 5516
Author(s):  
Óscar Osorio-Conles ◽  
Josep Vidal ◽  
Ana de Hollanda
Keyword(s):  
Bariatric Surgery ◽  
Adipose Tissue ◽  
Current Knowledge ◽  
Matrix Remodeling ◽  
Metabolic Complications ◽  
Angiogenic Potential ◽  
Sustained Weight Loss ◽  
Adipocyte Hypertrophy ◽  
Fat Depot ◽  
And Function

Bariatric surgery (BS) procedures are actually the most effective intervention to help subjects with severe obesity achieve significant and sustained weight loss. White adipose tissue (WAT) is increasingly recognized as the largest endocrine organ. Unhealthy WAT expansion through adipocyte hypertrophy has pleiotropic effects on adipocyte function and promotes obesity-associated metabolic complications. WAT dysfunction in obesity encompasses an altered adipokine secretome, unresolved inflammation, dysregulated autophagy, inappropriate extracellular matrix remodeling and insufficient angiogenic potential. In the last 10 years, accumulating evidence suggests that BS can improve the WAT function beyond reducing the fat depot sizes. The causal relationships between improved WAT function and the health benefits of BS merits further investigation. This review summarizes the current knowledge on the short-, medium- and long-term outcomes of BS on the WAT composition and function.

scholarly journals DNMT1 maintains metabolic fitness of adipocytes through acting as an epigenetic safeguard of mitochondrial dynamics

2021 ◽  
Vol 118 (11) ◽  
pp. e2021073118
Author(s):  
Yoon Jeong Park ◽  
Sangseon Lee ◽  
Sangsoo Lim ◽  
Hahn Nahmgoong ◽  
Yul Ji ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Adipose Tissue ◽  
Energy Metabolism ◽  
Mitochondrial Dynamics ◽  
Ctcf Binding ◽  
Mitochondrial Bioenergetics ◽  
Metabolic Complications ◽  
Genetic Ablation ◽  
Adipocyte Hypertrophy ◽  
Metabolic Fitness

White adipose tissue (WAT) is a key regulator of systemic energy metabolism, and impaired WAT plasticity characterized by enlargement of preexisting adipocytes associates with WAT dysfunction, obesity, and metabolic complications. However, the mechanisms that retain proper adipose tissue plasticity required for metabolic fitness are unclear. Here, we comprehensively showed that adipocyte-specific DNA methylation, manifested in enhancers and CTCF sites, directs distal enhancer-mediated transcriptomic features required to conserve metabolic functions of white adipocytes. Particularly, genetic ablation of adipocyte Dnmt1, the major methylation writer, led to increased adiposity characterized by increased adipocyte hypertrophy along with reduced expansion of adipocyte precursors (APs). These effects of Dnmt1 deficiency provoked systemic hyperlipidemia and impaired energy metabolism both in lean and obese mice. Mechanistically, Dnmt1 deficiency abrogated mitochondrial bioenergetics by inhibiting mitochondrial fission and promoted aberrant lipid metabolism in adipocytes, rendering adipocyte hypertrophy and WAT dysfunction. Dnmt1-dependent DNA methylation prevented aberrant CTCF binding and, in turn, sustained the proper chromosome architecture to permit interactions between enhancer and dynamin-1–like protein gene Dnm1l (Drp1) in adipocytes. Also, adipose DNMT1 expression inversely correlated with adiposity and markers of metabolic health but positively correlated with AP-specific markers in obese human subjects. Thus, these findings support strategies utilizing Dnmt1 action on mitochondrial bioenergetics in adipocytes to combat obesity and related metabolic pathology.

scholarly journals Deciphering Adipose Tissue Extracellular Vesicles Protein Cargo and Its Role in Obesity

2020 ◽  
Vol 21 (24) ◽  
pp. 9366
Author(s):  
Tamara Camino ◽  
Nerea Lago-Baameiro ◽  
Aurelio Martis-Sueiro ◽  
Iván Couto ◽  
Francisco Santos ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Extracellular Vesicles ◽  
Metabolic Disorders ◽  
Current Knowledge ◽  
Local Level ◽  
Functional Roles ◽  
Intracellular Proteins ◽  
Key Players ◽  
Membrane Antigens ◽  
And Function

The extracellular vesicles (EVs) have emerged as key players in metabolic disorders rising as an alternative way of paracrine/endocrine communication. In particular, in relation to adipose tissue (AT) secreted EVs, the current knowledge about its composition and function is still very limited. Nevertheless, those vesicles have been lately suggested as key players in AT communication at local level, and also with other metabolic peripheral and central organs participating in physiological homoeostasis, and also contributing to the metabolic deregulation related to obesity, diabetes, and associated comorbidities. The aim of this review is to summarize the most relevant data around the EVs secreted by adipose tissue, and especially in the context of obesity, focusing in its protein cargo. The description of the most frequent proteins identified in EVs shed by AT and its components, including their changes under pathological status, will give the reader a whole picture about the membrane/antigens, and intracellular proteins known so far, in an attempt to elucidate functional roles, and also suggesting biomarkers and new paths of therapeutic action.

scholarly journals Targeting Abdominal Obesity and Its Complications with Dietary Phytoestrogens

Nutrients ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 582 ◽  
Author(s):  
Alina Kuryłowicz ◽  
Marta Cąkała-Jakimowicz ◽  
Monika Puzianowska-Kuźnicka
Keyword(s):  
Body Composition ◽  
Adipose Tissue ◽  
Hormone Replacement ◽  
Visceral Obesity ◽  
Obese Individual ◽  
Dependent Manner ◽  
Metabolic Complications ◽  
Beneficial Effects ◽  
And Function

In the assessment of the health risk of an obese individual, both the amount of adipose tissue and its distribution and metabolic activity are essential. In adults, the distribution of adipose tissue differs in a gender-dependent manner and is regulated by sex steroids, especially estrogens. Estrogens affect adipocyte differentiation but are also involved in the regulation of the lipid metabolism, insulin resistance, and inflammatory activity of the adipose tissue. Their deficiency results in unfavorable changes in body composition and increases the risk of metabolic complications, which can be partially reversed by hormone replacement therapy. Therefore, the idea of the supplementation of estrogen-like compounds to counteract obesity and related complications is compelling. Phytoestrogens are natural plant-derived dietary compounds that resemble human estrogens in their chemical structure and biological activity. Supplementation with phytoestrogens may confer a range of beneficial effects. However, results of studies on the influence of phytoestrogens on body composition and prevalence of obesity are inconsistent. In this review, we present data from in vitro, animal, and human studies regarding the role of phytoestrogens in adipose tissue development and function in the context of their potential application in the prevention of visceral obesity and related complications.

scholarly journals Role of Subcutaneous Adipose Tissue in the Pathogenesis of Insulin Resistance

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Pavankumar Patel ◽  
Nicola Abate
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
The United States ◽  
Relative Role ◽  
Functional Characteristics ◽  
Metabolic Complications ◽  
Fat Depot ◽  
Subcutaneous Adipose

Burden of obesity has increased significantly in the United States over last few decades. Association of obesity with insulin resistance and related cardiometabolic problems is well established. Traditionally, adipose tissue in visceral fat depot has been considered a major culprit in development of insulin resistance. However, growing body of the literature has suggested that adipose tissue in subcutaneous fat depot, not only due to larger volume but also due to inherent functional characteristics, can have significant impact on development of insulin resistance. There are significant differences in functional characteristics of subcutaneous abdominal/truncal versus gluteofemoral depots. Decreased capacity for adipocyte differentiation and angiogenesis along with adipocyte hypertrophy can trigger vicious cycle of inflammation in subcutaneous adipose tissue and subsequent ectopic fat deposition. It is important to shift focus from fat content to functional heterogeneity in adipose tissue depots to better understand the relative role of subcutaneous adipose tissue in metabolic complications of obesity. Therapeutic lifestyle change continues to be the most important intervention in clinical practice at any level of increased adiposity. Future pharmaceutical interventions aimed at improving adipose tissue function in various subcutaneous depots have potential to help maintain adequate insulin sensitivity and reduce risk for development of insulin resistance complications.

scholarly journals Adipogenesis and lipotoxicity: role of peroxisome proliferator-activated receptor γ (PPARγ) and PPARγcoactivator-1 (PGC1)

2007 ◽  
Vol 10 (10A) ◽  
pp. 1132-1137 ◽  
Author(s):  
Gema Medina-Gomez ◽  
Sarah Gray ◽  
Antonio Vidal-Puig
Keyword(s):  
Insulin Resistance ◽  
Fatty Acids ◽  
Adipose Tissue ◽  
Peroxisome Proliferator ◽  
Metabolic Complications ◽  
Peroxisome Proliferator Activated Receptor ◽  
Toxic Response ◽  
Increased Risk ◽  
And Function

AbstractObesity is characterised by an increase in the adipose deposits, resulting from an imbalance between food intake and energy expenditure. When expansion of the adipose tissue reaches its maximum limit, as in obesity, fat accumulates in non-adipose tissues such as liver, heart, muscle and pancreas, developing a toxic response known as lipotoxicity, a condition that promotes the development of insulin resistance and other metabolic complications. Thus, the lipotoxic state may contribute to the increased risk of insulin resistance, diabetes, fatty liver and cardiovascular complications associated with obesity.We are interested in studying adipose tissue, specifically how mechanisms of adipogenesis and remodelling of adipose tissue, in terms of size and function of the adipocytes, could be considered a strategy to increase the capacity for lipid storage and prevent lipotoxicity. The peroxisome proliferator-activated receptors (PPARs) are a family of transcription factors that regulate energy balance by promoting either energy deposition or energy dissipation. Under normal physiological conditions, PPARγ is mainly expressed in adipose tissue and regulates diverse functions such as the development of fat cells and their capacity to store lipids. The generation of PPARγ knockout mice, either tissue specific or isoform specific, has provided new models to study PPARγ’s role in adipose tissue differentiation and function and have highlighted the essential role of PPARγ in adipogenesis and lipogenesis.A second strategy to prevent lipotoxicity is to increase the capacity of tissues to oxidise fatty acids. PPARγcoactivator-1α is a coactivator of PPARγ that induces the expression of genes that promote the differentiation of preadipocytes to brown adipocytes. Recently, it has been implicated in increasing the oxidation of fatty acids via increasing mitochondrial capacity and function, making this co-factor a key candidate for the treatment of lipotoxicity.

scholarly journals Adipocyte hypertrophy is associated with lysosomal permeability both in vivo and in vitro: role in adipose tissue inflammation

2012 ◽  
Vol 303 (5) ◽  
pp. E597-E606 ◽  
Author(s):  
Agnieszka Gornicka ◽  
Jade Fettig ◽  
Akiko Eguchi ◽  
Michael P. Berk ◽  
Samjhana Thapaliya ◽  
...  
Keyword(s):  
Cell Death ◽  
Adipose Tissue ◽  
Saturated Fatty Acids ◽  
Macrophage Infiltration ◽  
Early Event ◽  
Metabolic Complications ◽  
Adipocyte Cell ◽  
Adipocyte Hypertrophy

Obesity in both humans and rodents is characterized by adipocyte hypertrophy and the presence of death adipocytes surrounded by macrophages forming “crown-like structures.” However, the biochemical pathways involved in triggering adipocyte death as well as the role of death adipocytes in adipose tissue remodeling and macrophage infiltration remain poorly understood. We now show that induction of adipocyte hypertrophy by incubation of mature adipocytes with saturated fatty acids results in lysosomal destabilization and cathepsin B (ctsb), a key lysosomal cysteine protease, activation and redistribution into the cytosol. ctsb activation was required for the lysosomal permeabilization, and its inhibition protected cells against mitochondrial dysfunction. With the use of a dietary murine model of obesity, ctsb activation was detected in adipose tissue of these mice. This is an early event during weight gain that correlates with the presence of death adipocytes, and precedes macrophage infiltration of adipose tissue. Moreover, ctsb-deficient mice showed decreased lysosomal permeabilization in adipocytes and were protected against adipocyte cell death and macrophage infiltration to adipose tissue independent of body weight. These data strongly suggest that ctsb activation and lysosomal permeabilization in adipocytes are key initial events that contribute to the adipocyte cell death and macrophage infiltration into adipose tissue associated with obesity. Inhibition of ctsb activation may be a new therapeutic strategy for the treatment of obesity-associated metabolic complications.

scholarly journals Targeting White Adipose Tissue with Exercise or Bariatric Surgery as Therapeutic Strategies in Obesity

Biology ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 16 ◽  
Author(s):  
Flávia Giolo De Carvalho ◽  
Lauren Sparks
Keyword(s):  
Bariatric Surgery ◽  
Adipose Tissue ◽  
Resistance Exercise ◽  
Treatment Strategies ◽  
Whole Body ◽  
Metabolic Complications ◽  
Bona Fide ◽  
Treatment Of Obesity ◽  
Exercise Induced ◽  
The Impact

Adipose tissue is critical to whole-body energy metabolism and has become recognized as a bona fide endocrine organ rather than an inert lipid reservoir. As such, adipose tissue is dynamic in its ability to secrete cytokines, free fatty acids, lipokines, hormones and other factors in response to changes in environmental stimuli such as feeding, fasting and exercise. While excess adipose tissue, as in the case of obesity, is associated with metabolic complications, mass itself is not the only culprit in obesity-driven metabolic abnormalities, highlighting the importance of healthy and metabolically adaptable adipose tissue. In this review, we discuss the fundamental cellular processes of adipose tissue that become perturbed in obesity and the impact of exercise on these processes. While both endurance and resistance exercise can promote positive physiological adaptations in adipose tissue, endurance exercise has a more documented role in remodeling adipocytes, increasing adipokine secretion and fatty acid mobilization and oxidation during post-exercise compared with resistance exercise. Exercise is considered a viable therapeutic strategy for the treatment of obesity to optimize body composition, in particular as an adjuvant therapy to bariatric surgery; however, there is a gap in knowledge of the molecular underpinnings of these exercise-induced adaptations, which could provide more insight and opportunity for precision-based treatment strategies.

scholarly journals Relevance of Leptin and Other Adipokines in Obesity-Associated Cardiovascular Risk

Nutrients ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2664 ◽  
Author(s):  
Manuel F. Landecho ◽  
Carlota Tuero ◽  
Víctor Valentí ◽  
Idoia Bilbao ◽  
Magdalena de la Higuera ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Adipose Tissue ◽  
The Body ◽  
Matrix Remodeling ◽  
Nonalcoholic Fatty Liver ◽  
Visceral Fat Accumulation ◽  
Vasoactive Factors ◽  
Increased Risk ◽  
Endocrine Organs ◽  
Adipocyte Hypertrophy

Obesity, which is a worldwide epidemic, confers increased risk for multiple serious conditions including type 2 diabetes, nonalcoholic fatty liver disease, and cardiovascular diseases. Adipose tissue is considered one of the largest endocrine organs in the body as well as an active tissue for cellular reactions and metabolic homeostasis rather than an inert tissue only for energy storage. The functional pleiotropism of adipose tissue relies on its ability to synthesize and release a large number of hormones, cytokines, extracellular matrix proteins, and growth and vasoactive factors, which are collectively called adipokines known to influence a variety of physiological and pathophysiological processes. In the obese state, excessive visceral fat accumulation causes adipose tissue dysfunctionality that strongly contributes to the onset of obesity-related comorbidities. The mechanisms underlying adipose tissue dysfunction include adipocyte hypertrophy and hyperplasia, increased inflammation, impaired extracellular matrix remodeling, and fibrosis together with an altered secretion of adipokines. This review describes the relevance of specific adipokines in the obesity-associated cardiovascular disease.

scholarly journals Shedding Light on the Role of Extracellular Vesicles in HIV Infection and Wound Healing

Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 584 ◽  
Author(s):  
Aseel Alqatawni ◽  
Adhikarimayum Lakhikumar Sharma ◽  
Beatrice Attilus ◽  
Mudit Tyagi ◽  
Rene Daniel
Keyword(s):  
Wound Healing ◽  
Hiv Infection ◽  
Extracellular Vesicles ◽  
Inflammatory Responses ◽  
Current Knowledge ◽  
Matrix Remodeling ◽  
Ongoing Research ◽  
Post Entry ◽  
And Function

Extracellular vesicles (EVs) play an important role in intercellular communication. They are naturally released from cells into the extracellular environment. Based on their biogenesis, release pathways, size, content, and function, EVs are classified into exosomes, microvesicles (MVs), and apoptotic bodies (ApoBDs). Previous research has documented that EVs, specifically exosomes and MVs, play an important role in HIV infection, either by promoting HIV infection and pathogenesis or by inhibiting HIV-1 to a certain extent. We have also previously reported that EVs (particularly exosomes) from vaginal fluids inhibit HIV at the post-entry step (i.e., reverse transcription, integration). Besides the role that EVs play in HIV, they are also known to regulate the process of wound healing by regulating both the immune and inflammatory responses. It is noted that during the advanced stages of HIV infection, patients are at greater risk of wound-healing and wound-related complications. Despite ongoing research, the data on the actual effects of EVs in HIV infection and wound healing are still premature. This review aimed to update the current knowledge about the roles of EVs in regulating HIV pathogenesis and wound healing. Additionally, we highlighted several avenues of EV involvement in the process of wound healing, including coagulation, inflammation, proliferation, and extracellular matrix remodeling. Understanding the role of EVs in HIV infection and wound healing could significantly contribute to the development of new and potent antiviral therapeutic strategies and approaches to resolve impaired wounds in HIV patients.

scholarly journals Human Bone Marrow Adipose Tissue is a Metabolically Active and Insulin-Sensitive Distinct Fat Depot

2020 ◽  
Vol 105 (7) ◽  
pp. 2300-2310 ◽  
Author(s):  
Tam T Pham ◽  
Kaisa K Ivaska ◽  
Jarna C Hannukainen ◽  
Kirsi A Virtanen ◽  
Martin E Lidell ◽  
...  
Keyword(s):  
Bariatric Surgery ◽  
Bone Marrow ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Whole Body ◽  
Morbidly Obese ◽  
Bone Marrow Adipose Tissue ◽  
Marrow Adipose Tissue ◽  
Obese Subjects ◽  
Fat Depot

Abstract Context Bone marrow (BM) in adult long bones is rich in adipose tissue, but the functions of BM adipocytes are largely unknown. We set out to elucidate the metabolic and molecular characteristics of BM adipose tissue (BMAT) in humans. Objective Our aim was to determine if BMAT is an insulin-sensitive tissue, and whether the insulin sensitivity is altered in obesity or type 2 diabetes (T2DM). Design This was a cross-sectional and longitudinal study. Setting The study was conducted in a clinical research center. Patients or Other Participants Bone marrow adipose tissue glucose uptake (GU) was assessed in 23 morbidly obese subjects (9 with T2DM) and 9 healthy controls with normal body weight. In addition, GU was assessed in another 11 controls during cold exposure. Bone marrow adipose tissue samples for molecular analyses were collected from non-DM patients undergoing knee arthroplasty. Intervention(s) Obese subjects were assessed before and 6 months after bariatric surgery and controls at 1 time point. Main Outcome Measure We used positron emission tomography imaging with 2-[18F]fluoro-2-deoxy-D-glucose tracer to characterize GU in femoral and vertebral BMAT. Bone marrow adipose tissue molecular profile was assessed using quantitative RT-PCR. Results Insulin enhances GU in human BMAT. Femoral BMAT insulin sensitivity was impaired in obese patients with T2DM compared to controls, but it improved after bariatric surgery. Furthermore, gene expression analysis revealed that BMAT was distinct from brown and white adipose tissue. Conclusions Bone marrow adipose tissue is a metabolically active, insulin-sensitive and molecularly distinct fat depot that may play a role in whole body energy metabolism.

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