scholarly journals Angiotensin type 2 receptor activation promotes browning of white adipose tissue and brown adipogenesis

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Aung Than ◽  
Shaohai Xu ◽  
Ru Li ◽  
MelvinKhee-Shing Leow ◽  
Lei Sun ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Receptor Activation ◽  
White Adipocytes ◽  
Brown Adipose ◽  
Beige Adipocytes ◽  
Angiotensin Type 2 Receptor ◽  
Angiotensin Type ◽  
Brown Adipogenesis

Abstract Brown adipose tissue dissipates energy in the form of heat. Recent studies have shown that adult humans possess both classical brown and beige adipocytes (brown-like adipocytes in white adipose tissue, WAT), and stimulating brown and beige adipocyte formation can be a new avenue to treat obesity. Angiotensin II (AngII) is a peptide hormone that plays important roles in energy metabolism via its angiotensin type 1 or type 2 receptors (AT1R and AT2R). Adipose tissue is a major source of AngII and expresses both types of its receptors, implying the autocrine and paracrine role of AngII in regulating adipose functions and self-remodeling. Here, based on the in vitro studies on primary cultures of mouse white adipocytes, we report that, AT2R activation, either by AngII or AT2R agonist (C21), induces white adipocyte browning, by increasing PPARγ expression, at least in part, via ERK1/2, PI3kinase/Akt and AMPK signaling pathways. It is also found that AngII–AT2R enhances brown adipogenesis. In the in vivo studies on mice, administration of AT1R antagonist (ZD7155) or AT2R agonist (C21) leads to the increase of WAT browning, body temperature and serum adiponectin, as well as the decrease of WAT mass and the serum levels of TNFα, triglycerides and free fatty acids. In addition, AT2R-induced browning effect is also observed in human white adipocytes, as evidenced by the increased UCP1 expression and oxygen consumption. Finally, we provide evidence that AT2R plays important roles in hormone T3-induced white adipose browning. This study, for the first time, reveals the browning and brown adipogenic effects of AT2R and suggests a potential therapeutic target to combat obesity and related metabolic disorders.

scholarly journals Hormonal factors in the control of the browning of white adipose tissue

2017 ◽  
Vol 31 (1) ◽  
Author(s):  
Jiamiao Hu ◽  
Mark Christian
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
White Adipose Tissue ◽  
Direct Effects ◽  
Hormonal Factors ◽  
White Adipocytes ◽  
Brown Adipose ◽  
Beige Adipocytes ◽  
Treatment Of Obesity ◽  
The Impact

AbstractAdipose tissue has been historically classified into anabolic white adipose tissue (WAT) and catabolic brown adipose tissue (BAT). Recent studies have revealed the plasticity of WAT, where white adipocytes can be induced into ‘brown-like’ heat-producing adipocytes (BRITE or beige adipocytes). Recruiting and activating BRITE adipocytes in WAT (so-called ‘browning’) is believed to provide new avenues for the treatment of obesity-related diseases. A number of hormonal factors have been found to regulate BRITE adipose development and activity through autocrine, paracrine and systemic mechanisms. In this mini-review we will discuss the impact of these factors on the browning process, especially those hormonal factors identified with direct effects on white adipocytes.

scholarly journals Metformin induces oxidative stress in white adipocytes and raises uncoupling protein 2 levels

2008 ◽  
Vol 199 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Andrea Anedda ◽  
Eduardo Rial ◽  
M Mar González-Barroso
Keyword(s):  
Oxidative Stress ◽  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Uncoupling Protein ◽  
Acid Oxidation ◽  
Protein Levels ◽  
White Adipocytes ◽  
Epididymal White Adipose Tissue ◽  
Amp Activated Protein Kinase

Metformin is a drug widely used to treat type 2 diabetes. It enhances insulin sensitivity by improving glucose utilization in tissues like liver or muscle. Metformin inhibits respiration, and the decrease in cellular energy activates the AMP-activated protein kinase that in turn switches on catabolic pathways. Moreover, metformin increases lipolysis and β-oxidation in white adipose tissue, thereby reducing the triglyceride stores. The uncoupling proteins (UCPs) are transporters that lower the efficiency of mitochondrial oxidative phosphorylation. UCP2 is thought to protect against oxidative stress although, alternatively, it could play an energy dissipation role. The aim of this work was to analyse the involvement of UCP2 on the effects of metformin in white adipocytes. We studied the effect of this drug in differentiating 3T3-L1 adipocytes and found that metformin causes oxidative stress since it increases the levels of reactive oxygen species (ROS) and lowers the aconitase activity. Variations in UCP2 protein levels parallel those of ROS. Metformin also increases lipolysis in these cells although only when the levels of ROS and UCP2 have decreased. Hence, UCP2 does not appear to be needed to facilitate fatty acid oxidation. Furthermore, treatment of C57BL/6 mice with metformin also augmented the levels of UCP2 in epididymal white adipose tissue. We conclude that metformin treatment leads to the overexpression of UCP2 in adipocytes to minimize the oxidative stress that is probably due to the inhibition of respiration caused by the drug.

scholarly journals Neuronal Modulation of Brown Adipose Activity Through Perturbation of White Adipocyte Lipogenesis

2018 ◽  
Author(s):  
Adilson Guilherme ◽  
David J Pedersen ◽  
Felipe Henriques ◽  
Alexander H. Bedard ◽  
Elizabeth Henchey ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Fatty Acid Synthase ◽  
Sympathetic Neurons ◽  
Sympathetic Innervation ◽  
Long Distance ◽  
Brown Adipocytes ◽  
White Adipocyte ◽  
Brown Adipose ◽  
Beige Adipocytes

ABSTRACTWhite adipose tissue (WAT) secretes factors to communicate with other metabolic organs to maintain energy homeostasis. We previously reported that perturbation of adipocyte de novo lipogenesis (DNL) by deletion of fatty acid synthase (FASN) causes expansion of sympathetic neurons within white adipose tissue (WAT) and the appearance of “beige” adipocytes. Here we report evidence that white adipocyte DNL activity is also coupled to neuronal regulation and thermogenesis in brown adipose tissue (BAT). Induced deletion of FASN in all adipocytes in mature mice (iAdFASNKO) enhanced sympathetic innervation and neuronal activity as well as UCP1 expression in both WAT and BAT. In contrast, selective ablation of FASN in brown adipocytes of mice (iUCP1FASNKO) failed to modulate sympathetic innervation and the thermogenic program in BAT. Surprisingly, DNL in brown adipocytes was also dispensable in maintaining euthermia when UCP1FASNKO mice were cold-exposed. These results indicate that DNL in white adipocytes influences long distance signaling to BAT, which can modify BAT sympathetic innervation and expression of genes involved in thermogenesis.

scholarly journals Comparative analyses of chromatin landscape in white adipose tissue suggest humans may have less beigeing potential than other primates

2019 ◽  
Author(s):  
Devjanee Swain-Lenz ◽  
Alejandro Berrio ◽  
Alexias Safi ◽  
Gregory E. Crawford ◽  
Gregory A. Wray
Keyword(s):  
Adipose Tissue ◽  
Body Fat ◽  
White Adipose Tissue ◽  
Sequence Motif ◽  
Primary Role ◽  
Regulatory Regions ◽  
Comparative Analyses ◽  
White Adipocytes ◽  
Beige Adipocytes

AbstractHumans carry a much larger percentage of body fat than other primates. Despite the central role of adipose tissue in metabolism, little is known about the evolution of white adipose tissue in primates. Phenotypic divergence is often caused by genetic divergence in cis-regulatory regions. We examined the cis-regulatory landscape of fat during human origins by performing comparative analyses of chromatin accessibility in human and chimpanzee adipose tissue using macaque as an outgroup. We find that many cis-regulatory regions that are specifically closed in humans are under positive selection, located near genes involved with lipid metabolism, and contain a short sequence motif involved in the beigeing of fat, the process in which white adipocytes are transdifferentiated into beige adipocytes. While the primary role of white adipocytes is to store lipids, beige adipocytes are thermogeneic. The collective closing of many putative regulatory regions associated with beiging of fat suggests an adaptive mechanism that increases body fat in humans.

scholarly journals CD137 negatively affects “browning” of white adipose tissue during cold exposure

2020 ◽  
Vol 295 (7) ◽  
pp. 2034-2042 ◽  
Author(s):  
Raj Kamal Srivastava ◽  
Annalena Moliner ◽  
Ee-Soo Lee ◽  
Emily Nickles ◽  
Eunice Sim ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Cold Exposure ◽  
Uncoupling Protein ◽  
Surface Protein ◽  
Negative Regulator ◽  
Subcutaneous White Adipose Tissue ◽  
Brown Adipose ◽  
Beige Adipocytes ◽  
A Cell

Prolonged cold exposure stimulates the formation of brownlike adipocytes expressing UCP1 (uncoupling-protein-1) in subcutaneous white adipose tissue which, together with classical brown adipose tissue, contributes to maintaining body temperature in mammals through nonshivering thermogenesis. The mechanisms that regulate the formation of these cells, alternatively called beige or brite adipocytes, are incompletely understood. Here we report that mice lacking CD137, a cell surface protein used in several studies as a marker for beige adipocytes, showed elevated levels of thermogenic markers, including UCP1, increased numbers of beige adipocyte precursors, and expanded UCP1-expressing cell clusters in inguinal white adipose tissue after chronic cold exposure. CD137 knockout mice also showed enhanced cold resistance. These results indicate that CD137 functions as a negative regulator of “browning” in white adipose tissue and call into question the use of this protein as a functional marker for beige adipocytes.

scholarly journals Deciphering White Adipose Tissue Heterogeneity

Biology ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 23 ◽  
Author(s):  
Quyen Luong ◽  
Jun Huang ◽  
Kevin Y. Lee
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Lineage Tracing ◽  
The Body ◽  
Functional Heterogeneity ◽  
Tissue Heterogeneity ◽  
Adipose Tissue Depots ◽  
White Adipocytes ◽  
Increased Risk ◽  
Beige Adipocytes

Adipose tissue not only stores energy, but also controls metabolism through secretion of hormones, cytokines, proteins, and microRNAs that affect the function of cells and tissues throughout the body. Adipose tissue is organized into discrete depots throughout the body, and these depots are differentially associated with insulin resistance and increased risk of metabolic disease. In addition to energy-dissipating brown and beige adipocytes, recent lineage tracing studies have demonstrated that individual adipose depots are composed of white adipocytes that are derived from distinct precursor populations, giving rise to distinct subpopulations of energy-storing white adipocytes. In this review, we discuss this developmental and functional heterogeneity of white adipocytes both between and within adipose depots. In particular, we will highlight findings from our recent manuscript in which we find and characterize three major subtypes of white adipocytes. We will discuss these data relating to the differences between subcutaneous and visceral white adipose tissue and in relationship to previous work deciphering adipocyte heterogeneity within adipose tissue depots. Finally, we will discuss the possible implications of adipocyte heterogeneity may have for the understanding of lipodystrophies.

Physiological regulation and metabolic role of browning in white adipose tissue

2017 ◽  
Vol 31 (1) ◽  
Author(s):  
Aleksandra Jankovic ◽  
Vesna Otasevic ◽  
Ana Stancic ◽  
Biljana Buzadzic ◽  
Aleksandra Korac ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Diabetes Type 2 ◽  
Cellular Mechanisms ◽  
Physiological Regulation ◽  
Metabolic Role ◽  
Brown Adipose ◽  
Beige Adipose Tissue

AbstractGreat progress has been made in our understanding of the browning process in white adipose tissue (WAT) in rodents. The recognition that i) adult humans have physiologically inducible brown adipose tissue (BAT) that may facilitate resistance to obesity and ii) that adult human BAT molecularly and functionally resembles beige adipose tissue in rodents, reignited optimism that obesity and obesity-related diabetes type 2 can be battled by controlling the browning of WAT. In this review the main cellular mechanisms and molecular mediators of browning of WAT in different physiological states are summarized. The relevance of browning of WAT in metabolic health is considered primarily through a modulation of biological role of fat tissue in overall metabolic homeostasis.

scholarly journals Brown and Beige Fat: Therapeutic Potential in Obesity

2014 ◽  
Vol 6 (2) ◽  
pp. 65
Author(s):  
Anna Meiliana ◽  
Andi Wijaya
Keyword(s):  
Metabolic Disease ◽  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Therapeutic Effects ◽  
Brown Adipocytes ◽  
Brown Adipose ◽  
Beige Adipocytes ◽  
Beige Fat ◽  
Adipose Organ

BACKGROUND: The epidemic of obesity and type 2 diabetes presents a serious challenge to scientific and biomedical communities worldwide. There has been an upsurge of interest in the adipocyte coincident with the onset of the obesity epidemic and the realization that adipose tissue plays a major role in the regulation of metabolic function.CONTENT: Adipose tissue, best known for its role in fat storage, can also suppress weight gain and metabolic disease through the action of specialized, heat-producing adipocytes. Brown adipocytes are located in dedicated depots and express constitutively high levels of thermogenic genes, whereas inducible ‘brown-like’ adipocytes, also known as beige cells, develop in white fat in response to various activators. The activities of brown and beige fat cells reduce metabolic disease, including obesity, in mice and correlate with leanness in humans. Many genes and pathways that regulate brown and beige adipocyte biology have now been identified, providing a variety of promising therapeutic targets for metabolic disease.SUMMARY: The complexity of adipose tissue presents numerous challenges but also several opportunities for therapeutic intervention. There is persuasive evidence from animal models that enhancement of the function of brown adipocytes, beige adipocytes or both in humans could be very effective for treating type 2 diabetes and obesity. Moreover, there are now an extensive variety of factors and pathways that could potentially be targeted for therapeutic effects. In particular, the discoveries of circulating factors, such as irisin, fibroblast growth factor (FGF)21 and natriuretic peptides, that enhance brown and beige fat function in mice have garnered tremendous interest. Certainly, the next decade will see massive efforts to use beige and brown fat to ameliorate human metabolic disease.KEYWORDS: obesity, white adipose tissue, brown adipose tissue, beige adipose tissue, adipose organ, thermogenesis, energy expenditure

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