scholarly journals Elucidating the Regulatory Role of Melatonin in Brown, White, and Beige Adipocytes

Author(s):  
Ziye Xu ◽  
Wenjing You ◽  
Jiaqi Liu ◽  
Yizhen Wang ◽  
Tizhong Shan

AbstractThe high prevalence of obesity and its associated metabolic diseases has heightened the importance of understanding control of adipose tissue development and energy metabolism. In mammals, 3 types of adipocytes with different characteristics and origins have been identified: white, brown, and beige. Beige and brown adipocytes contain numerous mitochondria and have the capability to burn energy and counteract obesity, while white adipocytes store energy and are closely associated with metabolic disorders and obesity. Thus, regulation of the development and function of different adipocytes is important for controlling energy balance and combating obesity and related metabolic disorders. Melatonin is a neurohormone, which plays multiple roles in regulating inflammation, blood pressure, insulin actions, and energy metabolism. This article summarizes and discusses the role of melatonin in white, beige, and brown adipocytes, especially in affecting adipogenesis, inducing beige formation or white adipose tissue browning, enhancing brown adipose tissue mass and activities, improving anti-inflammatory and antioxidative effects, regulating adipokine secretion, and preventing body weight gain. Based on the current findings, melatonin is a potential therapeutic agent to control energy metabolism, adipogenesis, fat deposition, adiposity, and related metabolic diseases.

2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Craig Porter ◽  
Elisabet Børsheim ◽  
Labros S. Sidossis

The function ascribed to brown adipose tissue in humans has long been confined to thermoregulation in neonates, where this thermogenic capacity was thought lost with maturation. Recently, brown adipose tissue depots have been identified in adult humans. The significant oxidative capacity of brown adipocytes and the ability of their mitochondria to respire independently of ATP production, has led to renewed interest in the role that these adipocytes play in human energy metabolism. In our view, there is a need for robust physiological studies determining the relationship between molecular signatures of brown adipose tissue, adipose tissue mitochondrial function, and whole body energy metabolism, in order to elucidate the significance of thermogenic adipose tissue in humans. Until such information is available, the role of thermogenic adipose tissue in human metabolism and the potential that these adipocytes may prevent or treat obesity and metabolic diseases in humans will remain unknown. In this article, we summarize the recent literature pertaining to brown adipose tissue function with the aims of drawing the readers’ attention to the lack of data concerning the role of brown adipocytes in human physiology, and to the potential limitations of current research strategies.


2019 ◽  
Vol 243 (2) ◽  
pp. R19-R27 ◽  
Author(s):  
Joan Villarroya ◽  
Rubén Cereijo ◽  
Aleix Gavaldà-Navarro ◽  
Marion Peyrou ◽  
Marta Giralt ◽  
...  

In recent years, an important secretory role of brown adipose tissue (BAT) has emerged, which is consistent, to some extent, with the earlier recognition of the important secretory role of white fat. The so-called brown adipokines or ‘batokines’ may play an autocrine role, which may either be positive or negative, in the thermogenic function of brown adipocytes. Additionally, there is a growing recognition of the signalling molecules released by brown adipocytes that target sympathetic nerve endings (such as neuregulin-4 and S100b protein), vascular cells (e.g., bone morphogenetic protein-8b), and immune cells (e.g., C-X-C motif chemokine ligand-14) to promote the tissue remodelling associated with the adaptive BAT recruitment in response to thermogenic stimuli. Moreover, existing indications of an endocrine role of BAT are being confirmed through the release of brown adipokines acting on other distant tissues and organs; a recent example is the recognition that BAT-secreted fibroblast growth factor-21 and myostatin target the heart and skeletal muscle, respectively. The application of proteomics technologies is aiding the identification of new members of the brown adipocyte secretome, such as the extracellular matrix or complement system components. In summary, BAT can no longer be considered a mere producer of heat in response to environment or dietary challenges; it is also an active secretory tissue releasing brown adipokines with a relevant local and systemic action. The identification of the major brown adipokines and their roles is highly important for the discovery of novel candidates useful in formulating intervention strategies for metabolic diseases.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jain Jeong ◽  
Soyoung Jang ◽  
Song Park ◽  
Wookbong Kwon ◽  
Si-Yong Kim ◽  
...  

Abstract Background Juxtaposed with another zinc finger protein 1 (JAZF1) is associated with metabolic disorders, including type 2 diabetes mellitus (T2DM). Several studies showed that JAZF1 and body fat mass are closely related. We attempted to elucidate the JAZF1 functions on adipose development and related metabolism using in vitro and in vivo models. Results The JAZF1 expression was precisely regulated during adipocyte differentiation of 3T3-L1 preadipocyte and mouse embryonic fibroblasts (MEFs). Homozygous JAZF1 deletion (JAZF1-KO) resulted in impaired adipocyte differentiation in MEF. The JAZF1 role in adipocyte differentiation was demonstrated by the regulation of PPARγ—a key regulator of adipocyte differentiation. Heterozygous JAZF1 deletion (JAZF1-Het) mice fed a normal diet (ND) or a high-fat diet (HFD) had less adipose tissue mass and impaired glucose homeostasis than the control (JAZF1-Cont) mice. However, other metabolic organs, such as brown adipose tissue and liver, were negligible effect on JAZF1 deficiency. Conclusion Our findings emphasized the JAZF1 role in adipocyte differentiation and related metabolism through the heterozygous knockout mice. This study provides new insights into the JAZF1 function in adipose development and metabolism, informing strategies for treating obesity and related metabolic disorders.


2020 ◽  
Vol 117 (26) ◽  
pp. 15055-15065 ◽  
Author(s):  
Mengxi Jiang ◽  
Tony E. Chavarria ◽  
Bingbing Yuan ◽  
Harvey F. Lodish ◽  
Nai-Jia Huang

Phosphocholine phosphatase-1 (PHOSPHO1) is a phosphocholine phosphatase that catalyzes the hydrolysis of phosphocholine (PC) to choline. Here we demonstrate that the PHOSPHO1 transcript is highly enriched in mature brown adipose tissue (BAT) and is further induced by cold and isoproterenol treatments of BAT and primary brown adipocytes. In defining the functional relevance of PHOPSPHO1 in BAT thermogenesis and energy metabolism, we show that PHOSPHO1 knockout mice are cold-tolerant, with higher expression of thermogenic genes in BAT, and are protected from high-fat diet-induced obesity and development of insulin resistance. Treatment of mice with the PHOSPHO1 substrate phosphocholine is sufficient to induce cold tolerance, thermogenic gene expression, and allied metabolic benefits. Our results reveal a role of PHOSPHO1 as a negative regulator of BAT thermogenesis, and inhibition of PHOSPHO1 or enhancement of phosphocholine represent innovative approaches to manage the metabolic syndrome.


2018 ◽  
Author(s):  
Adilson Guilherme ◽  
David J Pedersen ◽  
Felipe Henriques ◽  
Alexander H. Bedard ◽  
Elizabeth Henchey ◽  
...  

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.


2021 ◽  
Vol 12 ◽  
Author(s):  
Carolin Muley ◽  
Stefan Kotschi ◽  
Alexander Bartelt

The acclimatization of brown adipose tissue (BAT) to sustained cold exposure requires an adaptive increase in proteasomal protein quality control. Ubiquilins represent a recently identified family of shuttle proteins with versatile functions in protein degradation, such as facilitating substrate targeting and proteasomal degradation. However, whether ubiquilins participate in brown adipocyte function has not been investigated so far. Here, we determine the role of ubiquilins for proteostasis and non-shivering thermogenesis in brown adipocytes. We found that Ubqln1, 2 and 4 are highly expressed in BAT and their expression was induced by cold and proteasomal inhibition. Surprisingly, silencing of ubiquilin gene expression (one or multiple in combinations) did not lead to aggravated ER stress or inflammation. Moreover, ubiquitin level and proteasomal activity under basal conditions were not impacted by loss of ubiquilins. Also, non-shivering thermogenesis measured by norepinephrine-induced respiration remained intact after loss of ubiquilins. In conclusion, ubiquilin proteins are highly abundant in BAT and regulated by cold, but they are dispensable for brown adipocyte proteostasis and thermogenesis.


Endocrinology ◽  
2018 ◽  
Vol 159 (7) ◽  
pp. 2545-2553 ◽  
Author(s):  
Carlos Henrique Sponton ◽  
Shingo Kajimura

Abstract Beige adipocytes are an inducible form of thermogenic adipose cells that emerge within the white adipose tissue in response to a variety of environmental stimuli, such as chronic cold acclimation. Similar to brown adipocytes that reside in brown adipose tissue depots, beige adipocytes are also thermogenic; however, beige adipocytes possess unique, distinguishing characteristics in their developmental regulation and biological function. This review highlights recent advances in our understanding of beige adipocytes, focusing on the diverse roles of beige fat in the regulation of energy homeostasis that are independent of the canonical thermogenic pathway via uncoupling protein 1.


Epigenomes ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 3
Author(s):  
Ravikanth Nanduri

Adipocytes play an essential role in maintaining energy homeostasis in mammals. The primary function of white adipose tissue (WAT) is to store energy; for brown adipose tissue (BAT), primary function is to release fats in the form of heat. Dysfunctional or excess WAT can induce metabolic disorders such as dyslipidemia, obesity, and diabetes. Preadipocytes or adipocytes from WAT possess sufficient plasticity as they can transdifferentiate into brown-like beige adipocytes. Studies in both humans and rodents showed that brown and beige adipocytes could improve metabolic health and protect from metabolic disorders. Brown fat requires activation via exposure to cold or β-adrenergic receptor (β-AR) agonists to protect from hypothermia. Considering the fact that the usage of β-AR agonists is still in question with their associated side effects, selective induction of WAT browning is therapeutically important instead of activating of BAT. Hence, a better understanding of the molecular mechanisms governing white adipocyte browning is vital. At the same time, it is also essential to understand the factors that define white adipocyte identity and inhibit white adipocyte browning. This literature review is a comprehensive and focused update on the epigenetic regulators crucial for differentiation and browning of white adipocytes.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Jie Li ◽  
Ran An ◽  
Simin Liu ◽  
Haiyan Xu

Abstract Objectives Sucrose Non-Fermenting Related Kinase (SNRK), a serine/threonine kinase, is a novel member of the AMPK/SNF1 family. We previously reported that adipose specific SNRK deficiency induced systemic inflammation and insulin resistance. In this study, we aimed to dissect the role of SNRK in white versus brown adipose tissue in insulin signaling and glucose homeostasis. Methods The SNRKloxp/loxp mice were mated with adiponectin-Cre (A-Cre) transgenic mice to generate the adipose tissue specific knockout model (SNRK−/−, A-Cre), and with UCP1-Cre (U-Cre) mice to generate the brown adipose tissue (BAT) specific knockout model (SNRK−/−, U-Cre). RNA sequencing and phosphoproteomics analysis were applied to identify the signaling pathways affected by SNRK deficiency and the potential substrate of SNRK. Results SNRK deletion exclusively in BAT is sufficient to impair insulin signaling and glucose uptake without inducing local and systemic inflammation. Phosphoproteomic study identified PPP2R5D as the potential substrate of SNRK that regulates insulin signaling through controlling PP2A activity. Dephosphorylated PPP2R5D promotes constitutive assembly of PP2A-Akt complex in SNRK deficient primary brown adipocytes and BAT, therefore reduces insulin stimulated Akt phosphorylation and subsequent glucose uptake. RNA sequencing data provided further evidence to show that the PI3K/AKT signaling pathway is suppressed by SNRK deletion in primary brown adipocytes. Conclusions Insulin resistance in BAT alone is not sufficient to impact whole body glucose homeostasis, indicating that the role of SNRK in WAT and inflammation might be critical for observed systemic insulin resistance in SNRK−/−, A-Cre mice. Funding Sources National Institute of Diabetes and Digestive and Kidney Diseases (R01 DK103699).


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Dammah Otieno ◽  
Ya Pei ◽  
Inah Gu ◽  
Sun-Ok Lee ◽  
Hye Won Kang

Abstract Objectives Activation of non-shivering thermogenesis in adipose tissues and alteration in intestinal microbiome have been linked with improved obese condition. With emerging evidences of dietary compounds to prevent obesity, the objective of this study was to examine whether quercetin activates non-shivering thermogenesis in adipose tissues and influences intestinal microbiome, which eventually improves obese condition. Methods Four-week-old C57BL/6 male mice were fed either a low-fat diet (LFD) or a high-fat diet (HFD) with or without 1% quercetin (Q) for 16 weeks. On the completion of the feeding study, brown adipose tissue (BAT), white adipose tissue (WAT), and cecum were collected. Total RNA was extracted from BAT and WAT, and then cDNA was synthesized. The expression of genes that are involved in the regulation of non-shivering thermogenesis such as uncoupling protein 1 (ucp1), cell death-inducing DFFA-like effector A (cidea), peroxisome proliferator-activated receptor gamma (pparγ), pparγ-coactivator 1 alpha (pgc1α), fibroblast growth factor 21 (fgf21), positive regulatory domain containing 16 (prdm16), and T-box protein 1 (tbx1) were determined by a real-time PCR. The expression of the proteins such as UCP1 and AMP-activated protein kinase (AMPK) was assessed by western blot analysis. Microbial populations in cecum were analyzed via the Illumnia MiSeq sequencing platform and QIIME (Quantitative Insights Into Microbial Ecology) Software. Results Mice fed HFDQ showed reduced body weight and retroperitoneal (R) WAT weight compared to mice fed HFD. Quercetin supplementation increased the expression of ucp1, prdm16, pgc1α, cidea, and tbx1 genes in BAT and RWAT of mice fed HFD. The expression of UCP1 protein and phosphorylation of AMPK were increased. However, browning effect was not observed in other WATs. Mice fed LFDQ and HFDQ exhibited higher relative abundance of Bacteroidetes than mice fed LFD and HFD whereas the relative abundance of Firmicutes was decreased. Conclusions Quercetin may be a potential dietary compound that increases energy metabolism by activating BAT and attracting beige adipocytes in RWAT. In addition, quercetin-induced energy metabolism may have a correlation with changes of microbial populations in intestine. Funding Sources The work was supported by USDA.


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