scholarly journals Adipose Tissue and FoxO1: Bridging Physiology and Mechanisms

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 849 ◽  
Author(s):  
Laura Ioannilli ◽  
Fabio Ciccarone ◽  
Maria Rosa Ciriolo

Forkhead box O class proteins (FoxOs) are expressed nearly in all tissues and are involved in different functions such as energy metabolism, redox homeostasis, differentiation, and cell cycle arrest. The plasticity of FoxOs is demonstrated by post-translational modifications that determine diverse levels of transcriptional regulations also controlled by their subcellular localization. Among the different members of the FoxO family, we will focus on FoxO1 in adipose tissue, where it is abundantly expressed and is involved in differentiation and transdifferentiation processes. The capability of FoxO1 to respond differently in dependence of adipose tissue subtype underlines the specific involvement of the transcription factor in energy metabolism and the “browning” process of adipocytes. FoxO1 can localize to nuclear, cytoplasm, and mitochondrial compartments of adipocytes responding to different availability of nutrients and source of reactive oxygen species (ROS). Specifically, fasted state produced-ROS enhance the nuclear activity of FoxO1, triggering the transcription of lipid catabolism and antioxidant response genes. The enhancement of lipid catabolism, in combination with ROS buffering, allows systemic energetic homeostasis and metabolic adaptation of white/beige adipocytes. On the contrary, a fed state induces FoxO1 to accumulate in the cytoplasm, but also in the mitochondria where it affects mitochondrial DNA gene expression. The importance of ROS-mediated signaling in FoxO1 subcellular localization and retrograde communication will be discussed, highlighting key aspects of FoxO1 multifaceted regulation in adipocytes.

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1090
Author(s):  
Ursula Abou-Rjeileh ◽  
G. Andres Contreras

Lipid mobilization in adipose tissues, which includes lipogenesis and lipolysis, is a paramount process in regulating systemic energy metabolism. Reactive oxygen and nitrogen species (ROS and RNS) are byproducts of cellular metabolism that exert signaling functions in several cellular processes, including lipolysis and lipogenesis. During lipolysis, the adipose tissue generates ROS and RNS and thus requires a robust antioxidant response to maintain tight regulation of redox signaling. This review will discuss the production of ROS and RNS within the adipose tissue, their role in regulating lipolysis and lipogenesis, and the implications of antioxidants on lipid mobilization.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Miroslava Cedikova ◽  
Michaela Kripnerová ◽  
Jana Dvorakova ◽  
Pavel Pitule ◽  
Martina Grundmanova ◽  
...  

Mitochondria play a key role in energy metabolism in many tissues, including cardiac and skeletal muscle, brain, liver, and adipose tissue. Three types of adipose depots can be identified in mammals, commonly classified according to their colour appearance: the white (WAT), the brown (BAT), and the beige/brite/brown-like (bAT) adipose tissues. WAT is mainly involved in the storage and mobilization of energy and BAT is predominantly responsible for nonshivering thermogenesis. Recent data suggest that adipocyte mitochondria might play an important role in the development of obesity through defects in mitochondrial lipogenesis and lipolysis, regulation of adipocyte differentiation, apoptosis, production of oxygen radicals, efficiency of oxidative phosphorylation, and regulation of conversion of white adipocytes into brown-like adipocytes. This review summarizes the main characteristics of each adipose tissue subtype and describes morphological and functional modifications focusing on mitochondria and their activity in healthy and unhealthy adipocytes.


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.


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.


2020 ◽  
Vol 134 (5) ◽  
pp. 473-512 ◽  
Author(s):  
Ryan P. Ceddia ◽  
Sheila Collins

Abstract With the ever-increasing burden of obesity and Type 2 diabetes, it is generally acknowledged that there remains a need for developing new therapeutics. One potential mechanism to combat obesity is to raise energy expenditure via increasing the amount of uncoupled respiration from the mitochondria-rich brown and beige adipocytes. With the recent appreciation of thermogenic adipocytes in humans, much effort is being made to elucidate the signaling pathways that regulate the browning of adipose tissue. In this review, we focus on the ligand–receptor signaling pathways that influence the cyclic nucleotides, cAMP and cGMP, in adipocytes. We chose to focus on G-protein–coupled receptor (GPCR), guanylyl cyclase and phosphodiesterase regulation of adipocytes because they are the targets of a large proportion of all currently available therapeutics. Furthermore, there is a large overlap in their signaling pathways, as signaling events that raise cAMP or cGMP generally increase adipocyte lipolysis and cause changes that are commonly referred to as browning: increasing mitochondrial biogenesis, uncoupling protein 1 (UCP1) expression and respiration.


2018 ◽  
Vol 15 (4) ◽  
pp. 345-354 ◽  
Author(s):  
Barbara D'Orio ◽  
Anna Fracassi ◽  
Maria Paola Cerù ◽  
Sandra Moreno

Background: The molecular mechanisms underlying Alzheimer's disease (AD) are yet to be fully elucidated. The so-called “amyloid cascade hypothesis” has long been the prevailing paradigm for causation of disease, and is today being revisited in relation to other pathogenic pathways, such as oxidative stress, neuroinflammation and energy dysmetabolism. The peroxisome proliferator-activated receptors (PPARs) are expressed in the central nervous system (CNS) and regulate many physiological processes, such as energy metabolism, neurotransmission, redox homeostasis, autophagy and cell cycle. Among the three isotypes (α, β/δ, γ), PPARγ role is the most extensively studied, while information on α and β/δ are still scanty. However, recent in vitro and in vivo evidence point to PPARα as a promising therapeutic target in AD. Conclusion: This review provides an update on this topic, focussing on the effects of natural or synthetic agonists in modulating pathogenetic mechanisms at AD onset and during its progression. Ligandactivated PPARα inihibits amyloidogenic pathway, Tau hyperphosphorylation and neuroinflammation. Concomitantly, the receptor elicits an enzymatic antioxidant response to oxidative stress, ameliorates glucose and lipid dysmetabolism, and stimulates autophagy.


2021 ◽  
Vol 22 (10) ◽  
pp. 5390
Author(s):  
Qianhui Zeng ◽  
Nannan Wang ◽  
Yaru Zhang ◽  
Yuxuan Yang ◽  
Shuangshuang Li ◽  
...  

Obesity-induced adipose tissue dysfunction and disorders of glycolipid metabolism have become a worldwide research priority. Zfp217 plays a crucial role in adipogenesis of 3T3-L1 preadipocytes, but about its functions in animal models are not yet clear. To explore the role of Zfp217 in high-fat diet (HFD)-induced obese mice, global Zfp217 heterozygous knockout (Zfp217+/−) mice were constructed. Zfp217+/− mice and Zfp217+/+ mice fed a normal chow diet (NC) did not differ significantly in weight gain, percent body fat mass, glucose tolerance, or insulin sensitivity. When challenged with HFD, Zfp217+/− mice had less weight gain than Zfp217+/+ mice. Histological observations revealed that Zfp217+/− mice fed a high-fat diet had much smaller white adipocytes in inguinal white adipose tissue (iWAT). Zfp217+/− mice had improved metabolic profiles, including improved glucose tolerance, enhanced insulin sensitivity, and increased energy expenditure compared to the Zfp217+/+ mice under HFD. We found that adipogenesis-related genes were increased and metabolic thermogenesis-related genes were decreased in the iWAT of HFD-fed Zfp217+/+ mice compared to Zfp217+/− mice. In addition, adipogenesis was markedly reduced in mouse embryonic fibroblasts (MEFs) from Zfp217-deleted mice. Together, these data indicate that Zfp217 is a regulator of energy metabolism and it is likely to provide novel insight into treatment for obesity.


2021 ◽  
pp. 101276
Author(s):  
Robert Hauffe ◽  
Michaela Rath ◽  
Mareike Schell ◽  
Katrin Ritter ◽  
Kai Kappert ◽  
...  

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