White Adipose Tissue Metabolism Research Articles

The Effect of a Sustained High-Fat Diet on the Metabolism of White and Brown Adipose Tissue and Its Impact on Insulin Resistance: A Selected Time Point Cross-Sectional Study.

(1) Background: studies on the long-term dynamic changes in fat depot metabolism in response to a high-fat diet (HFD) on hepatic lipid deposition and insulin resistance are sparse. This study investigated the dynamic changes produced by HFD and the production of dysfunctional fat depots on insulin resistance and liver lipid metabolism. (2) Methods: mice fed a chow or HFD (45% kcal fat) diet had three fat depots, liver, and blood collected at 6, 10, 20, and 30 weeks. Anthropometric changes and gene markers for adipogenesis, thermogenesis, ECM remodeling, inflammation, and tissue insulin resistance were measured. (3) Results: early responses to the HFD were increased body weight, minor deposition of lipid in liver, increased adipocyte size, and adipogenesis. Later changes were dysfunctional adipose depots, increased liver fat, insulin resistance (shown by changes in ITT) accompanied by increased inflammatory markers, increased fibrosis (fibrosis > 2-fold, p < 0.05 from week 6), and the presence of crown cells in white fat depots. Later, changes did not increase thermogenic markers in response to the increased calories and decreased UCP1 and PRDM16 proteins in WAT. (4) Conclusions: HFD feeding initially increased adipocyte diameter and number, but later changes caused adipose depots to become dysfunctional, restricting adipose tissue expansion, changing the brown/beige ratios in adipose depots, and causing ectopic lipid deposition and insulin resistance.

Brain-Restricted Inhibition of IL-6 Trans-Signaling Mildly Affects Metabolic Consequences of Maternal Obesity in Male Offspring.

Maternal obesity greatly affects next generations, elevating obesity risk in the offspring through perinatal programming and flawed maternal and newborn nutrition. The exact underlying mechanisms are poorly understood. Interleukin-6 (IL-6) mediates its effects through a membrane-bound receptor or by trans-signaling (tS), which can be inhibited by the soluble form of the co-receptor gp130 (sgp130). As IL-6 tS mediates western-style diet (WSD) effects via chronic low-grade inflammation (LGI) and LGI is an important mediator in brain–adipose tissue communication, this study aims at determining the effects of maternal obesity in a transgenic mouse model of brain-restricted IL-6tS inhibition (GFAPsgp130) on offspring’s short- and long-term body composition and epigonadal white adipose tissue (egWAT) metabolism. Female wild type (WT) or transgenic mice were fed either standard diet (SD) or WSD pregestationally, during gestation, and lactation. Male offspring received SD from postnatal day (P)21 to P56 and were metabolically challenged with WSD from P56 to P120. At P21, offspring from WT and transgenic dams that were fed WSD displayed increased body weight and egWAT mass, while glucose tolerance testing showed the strongest impairment in GFAPsgp130WSD offspring. Simultaneously, egWAT proteome reveals a characteristic egWAT expression pattern in offspring as a result of maternal conditions. IL-6tS inhibition in transgenic mice was in tendency associated with lower body weight in dams on SD and their respective offspring but blunted by the WSD. In conclusion, maternal nutrition affects offspring’s body weight and egWAT metabolism predominantly independent of IL-6tS inhibition, emphasizing the importance of maternal and newborn nutrition for long-term offspring health.

Protective Effects of Individual and Combined Low Dose Beta-Carotene and Metformin Treatments against High-Fat Diet-Induced Responses in Mice.

Anti-obesity activity has been reported for beta-carotene (BC) supplementation at high doses and metformin (MET). We studied whether BC treatment at a closer to dietary dose and MET treatment at a lower than therapeutic dose are effective in ameliorating unwanted effects of an obesogenic diet and whether their combination is advantageous. Obesity-prone mice were challenged with a high-fat diet (HFD, 45% energy as fat) for 4 weeks while receiving a placebo or being treated orally with BC (3 mg/kg/day), MET (100 mg/kg/day), or their combination (BC+MET); a fifth group received a placebo and was kept on a normal-fat diet (10% energy as fat). HFD-induced increases in body weight gain and inguinal white adipose tissue (WAT) adipocyte size were attenuated maximally or selectively in the BC+MET group, in which a redistribution towards smaller adipocytes was noted. Cumulative energy intake was unaffected, yet results suggested increased systemic energy expenditure and brown adipose tissue activation in the treated groups. Unwanted effects of HFD on glucose control and insulin sensitivity were attenuated in the treated groups, especially BC and BC+MET, in which hepatic lipid content was also decreased. Transcriptional analyses suggested effects on skeletal muscle and WAT metabolism could contribute to better responses to the HFD, especially in the MET and BC+MET groups. The results support the benefits of the BC+MET cotreatment.

Garlic Scape (Allium sativum L.) Extract Decreases Adipogenesis by Activating AMK-Activated Protein Kinase During the Differentiation in 3T3-L1 Adipocytes.

Regulating adipogenesis and lipogenesis in white adipose tissue (WAT) is an efficient strategy to reduce obesity. This study investigates whether garlic scape extract (GSE) has anti-adipogenic and anti-lipogenic effects and which stage of adipogenesis is critical for its effect using 3T3-L1 cells. 3T3-L1 cells that were treated with GSE during adipogenesis and differentiation exhibited reduced peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein a (Cebpa) and Cebpb, acetyl-CoA carboxylase, fatty acid synthase, sterol regulatory element binding protein 1c, diacylglycerol acyltransferase 1, and perilipin 1 genes. When the cells were treated with GSE during postdifferentiation or during preadipocytes, they showed less reduction and no change, respectively. Consistent with this, lipid accumulation was strongly reduced in the cells that were treated during adipogenesis and differentiation and to a lesser extent in the cells that were treated during preadipocytes and postdifferentiation. Phosphorylation on AMP-activated protein kinase (AMPK) and its downstream proteins was increased together with increased carnitine palmitoyl transferase 1α and phosphorylation on hormone-sensitive lipase in the cells that were treated with GSE during differentiation. In summary, GSE reduced intracellular lipid accumulation by suppressing adipogenic and lipogenic genes and proteins by possibly the activation of AMPK signaling pathway during adipocyte differentiation. This result indicates that garlic scape may have the potential to prevent obesity by regulating lipid metabolism in WAT.

Peripheral Dopamine Directly Acts on Insulin-Sensitive Tissues to Regulate Insulin Signaling and Metabolic Function

Dopamine is a key regulator of glucose metabolism in the central nervous system. However, dopamine is also present in the periphery and may have direct effects on insulin-sensitive tissues. Dopamine receptor 2 (D2R) agonist bromocriptine is a FDA-approved drug for type 2 diabetes. Herein, we explored the role of peripheral dopamine and its receptors in regulating glucose uptake and metabolism on insulin-sensitive tissues. Peripheral dopamine effect in [3H]2-deoxyglucose uptake in insulin-sensitive tissues was tested in vivo in rats. Direct effects on [3H]2-deoxyglucose uptake, insulin receptor phosphorylation, and regulation of metabolic function were tested ex vivo in the liver, soleus muscle, and white and brown adipose tissues. Bromocriptine and the antagonists domperidone, D2R antagonist, and haloperidol, antagonist of both dopamine receptor 1 (D1R) and D2R, were used to disclose dopamine receptors’ involvement.Peripheral dopamine increases glucose uptake in vivo. Ex vivo, only dopamine increased glucose uptake in the soleus, while bromocriptine increased it in the liver; the effects were reverted by haloperidol and domperidone, respectively. In adipose tissue, domperidone reverted dopamine- and bromocriptine-mediated potentiation of insulin-induced glucose uptake, but in turn increased the insulin receptor, Akt, AMPK, HSL, ACC, and ACL, phosphorylation. In the soleus muscle, AMPK-phosphorylation increased with bromocriptine and dopamine whose effects were suppressed by domperidone and haloperidol.In conclusion, peripheral dopamine stimulates glucose uptake with its receptors being differentially involved in glucose uptake in insulin-sensitive tissues. Dopamine also has a role in lipid metabolism in white adipose tissue. Altogether, these results suggest that peripheral modulation of the dopaminergic system should be further evaluated as a putative therapeutic approach for metabolic disorders.

Polygonum multiflorum Thunb. Hot Water Extract Reverses High-Fat Diet-Induced Lipid Metabolism of White and Brown Adipose Tissues in Obese Mice.

The purpose of the present study was to determine whether an anti-obesity effect of a Polygonum multiflorum Thunb. hot water extract (PW) was involved in the lipid metabolism of white adipose tissue (WAT) and brown adipose tissue (BAT) in high-fat diet (HFD)-induced C57BL/6N obese mice. Mice freely received a normal diet (NCD) or an HFD for 12 weeks; HFD-fed mice were orally given PW (100 or 300 mg/kg) or garcinia cambogia (GC, 200 mg/kg) once a day. After 12 weeks, PW (300 mg/kg) or GC significantly alleviated adiposity by reducing body weight, WAT weights, and food efficiency ratio. PW (300 mg/kg) improved hyperinsulinemia and enhanced insulin sensitivity. In addition, PW (300 mg/kg) significantly down-regulated expression of carbohydrate-responsive element-binding protein (ChREBP) and diacylglycerol O-acyltransferase 2 (DGAT2) genes in WAT compared with the untreated HFD group. HFD increased BAT gene levels such as adrenoceptor beta 3 (ADRB3), peroxisome proliferator-activated receptor γ (PPARγ), hormone-sensitive lipase (HSL), cluster of differentiation 36 (CD36), fatty acid-binding protein 4 (FABP4), PPARγ coactivator 1-α (PGC-1α), PPARα, and carnitine palmitoyltransferase 1B (CPT1B) compared with the NCD group; however, PW or GC effectively reversed those levels. These findings suggest that the anti-obesity activity of PW was mediated via suppression of lipogenesis in WAT, leading to the normalization of lipid metabolism in BAT.

Interactive effects of aging and aerobic capacity on energy metabolism\u2013related metabolites of serum, skeletal muscle, and white adipose tissue

Aerobic capacity is a strong predictor of longevity. With aging, aerobic capacity decreases concomitantly with changes in whole body metabolism leading to increased disease risk. To address the role of aerobic capacity, aging, and their interaction on metabolism, we utilized rat models selectively bred for low and high intrinsic aerobic capacity (LCRs/HCRs) and compared the metabolomics of serum, muscle, and white adipose tissue (WAT) at two time points: Young rats were sacrificed at 9 months of age, and old rats were sacrificed at 21 months of age. Targeted and semi-quantitative metabolomics analysis was performed on the ultra-pressure liquid chromatography tandem mass spectrometry (UPLC-MS) platform. The effects of aerobic capacity, aging, and their interaction were studied via regression analysis. Our results showed that high aerobic capacity is associated with an accumulation of isovalerylcarnitine in muscle and serum at rest, which is likely due to more efficient leucine catabolism in muscle. With aging, several amino acids were downregulated in muscle, indicating more efficient amino acid metabolism, whereas in WAT less efficient amino acid metabolism and decreased mitochondrial β-oxidation were observed. Our results further revealed that high aerobic capacity and aging interactively affect lipid metabolism in muscle and WAT, possibly combating unfavorable aging-related changes in whole body metabolism. Our results highlight the significant role of WAT metabolism for healthy aging.

The confounding effects of sub-thermoneutral housing temperatures on aerobic exercise-induced adaptations in mouse subcutaneous white adipose tissue.

Mice are the most commonly used model organism for human biology, and failure to acknowledge fundamental differences in thermal biology between these species has confounded the study of adipose tissue metabolism in mice and its translational relevance to humans. Here, using exercise biochemistry as an example, we highlight the subtle yet detrimental effects sub-thermoneutral housing temperatures can have on the study of adipose tissue metabolism in mice. We encourage academics and publishers to consider ambient housing temperature as a key determinant in the methodological conception and reporting of all research on rodent white adipose tissue metabolism.

Role of the Endocannabinoid System in the Adipose Tissue with Focus on Energy Metabolism.

The endocannabinoid system is involved in a wide range of processes including the control of energy acquisition and expenditure. Endocannabinoids and their receptors are present in the central nervous system but also in peripheral tissues, notably the adipose tissues. The endocannabinoid system interacts with two main hormones regulating appetite, namely leptin and ghrelin. The inhibitory effect of the cannabinoid receptor 1 (CB1) antagonist rimonabant on fat mass suggested that the endocannabinoid system can also have a peripheral action in addition to its effect on appetite reduction. Thus, several investigations have focused on the peripheral role of the endocannabinoid system in the regulation of metabolism. The white adipose tissue stores energy as triglycerides while the brown adipose tissue helps to dissipate energy as heat. The endocannabinoid system regulates several functions of the adipose tissues to favor energy accumulation. In this review we will describe the presence of the endocannabinoid system in the adipose tissue. We will survey the role of the endocannabinoid system in the regulation of white and brown adipose tissue metabolism and how the eCB system participates in obesity and metabolic diseases.

Single-cell sequencing of human white adipose tissue identifies new cell states in health and obesity.

White adipose tissue (WAT) is an essential regulator of energy storage and systemic metabolic homeostasis. Regulatory networks consisting of immune and structural cells are necessary to maintain WAT metabolism, which can become impaired during obesity in mammals. Using single-cell transcriptomics and flow cytometry, we unveil a large-scale comprehensive cellular census of the stromal vascular fraction (SVF) of healthy lean and obese human WAT. We report novel subsets and developmental trajectories of adipose-resident innate lymphoid cells (ILCs), dendritic cells (DCs) and monocyte-derived macrophage populations that accumulate in obese WAT. Analysis of cell-cell ligand receptor interactions and obesity-enriched signaling pathways revealed a switch from immunoregulatory mechanisms in lean WAT to inflammatory networks in obese WAT. These results provide a detailed and unbiased cellular landscape of homeostatic and inflammatory circuits in healthy human WAT.

A fifty percent leucine-restricted diet reduces fat mass and improves glucose regulation

BackgroundLeucine deprivation modulates the dietary amino acid composition, reducing the fat content and improving the glucose tolerance, thus protecting the organism against obesity. However, a complete deprivation of leucine can lead to an extremely rapid fat loss in mice, accompanied by prolonged adverse effects such as weakness and mental fatigue. Therefore, in this study we aimed to seek the optimal concentration of dietary leucine that can reduce fat mass and improve the metabolism without the onset of severe effects.MethodsTo investigate whether there is a better concentration of diet leucine restriction (LR), based on the diet we conducted (A10021B), that can reduce fat mass and improve metabolism status without taking many negative effects, we fed 8 weeks old male C57Bl/6J mice with increasing degrees of leucine restriction diet 0% LR (control group), 25% LR, 50% LR, and 75% LR groups (4–6 mice each group). Fat mass and blood glucose levels were measured. The expression levels of genes involved in lipid metabolism in white adipose tissue (WAT) and liver, and proteins in insulin signaling were assessed in WAT, liver and muscle.ResultsWe found that the 50% LR group is the most proper group here at the lowest leucine effective concentration, which reduced fat mass (p < 0.05) and improved glucose regulation in mice over a 90 days feeding. Further studies revealed that lipid synthesis pathway (Fas, Scd1and Srebp1, p < 0.05) was downregulated and lipolysis (Atgl, p < 0.05) was upregulated in WAT in 50% LR group, compared to that in control group. Furthermore, glucose regulation (glucose tolerance test, p < 0.05) was also improved, and insulin signaling (p < 0.05) in the muscle was enhanced in 50% LR group while in WAT and liver were not changed.ConclusionsCollectively, a 50% LR in mice reduced fat mass and improved glucose regulation, which may function through modulating lipid synthesis and lipolysis pathway in adipose tissue as well as enhancing insulin signaling in muscle. So far, we provide a further consideration for carrying out the diet of leucine restriction to reduce fat and improve metabolism status before clinical study.

Electroconvulsive seizures lead to lipolytic-induced gene expression changes in mediobasal hypothalamus and decreased white adipose tissue mass.

AimsElectroconvulsive seizure (ECS) therapy is highly effective in the treatment of several psychiatric disorders, including depression. Past studies have shown that the rodent model of ECS reveals the activation of multiple brain regions including the hypothalamus, suggesting that this method of brain stimulation broadly regulates central neuronal function, which results in peripheral function. The ventromedial nucleus of the hypothalamus (VMH) plays an important role in feeding and energy homeostasis. Our previous study showed that ECS increases the expression of anorexigenic factors in the VMH and has an anorexigenic effect in a mouse model. Since the VMH is also suggested to play a critical role in the peripheral lipid metabolism of white adipose tissue (WAT), we hypothesized that ECS alters lipid metabolism via activation of the VMH.Methods and ResultsHere, we demonstrate that repeated ECS suppresses the fat mass of epididymal WAT and significantly increases the expression levels of lipolytic and brown adipose tissue markers such as Adrb3, Hsl/Lipe, and Ppargc1a. In the VMH, ECS increased the expression of multiple genes, notably Bdnf, Adcyap1, and Crhr2, which are not only anorexigenic factors but are also modulators of lipid metabolism. Furthermore, gold‐thioglucose‐induced hypothalamic lesions affecting the VMH abolished the effect of ECS on the WAT, indicating that hypothalamus activation is required for the phenotypic changes seen in the epididymal WAT.ConclusionOur data demonstrates a new effect of ECS on the lipid metabolism of WAT via induction of hypothalamic activity involving the VMH.

A multifunctional ingredient for the management of metabolic syndrome in cafeteria diet-fed rats.

The body weight-lowering properties of a multifunctional ingredient (MIX) based on conjugated linoleic acid at low doses, the flavonoids proanthocyanidins and anthocyanidins and the chicken feet hydrolysate Hpp11 have been previously reported. The aim of this study was to evaluate the effect of long-term administration of MIX on other cardiometabolic risk factors associated with metabolic syndrome (MetS) in rats fed a cafeteria diet (CAF). Male Wistar rats were fed CAF for 11 weeks, and during the last 3 weeks, animals were orally administered MIX or vehicle. Lipid tolerance tests were performed before and after MIX administration. At the end of the experimental period, serum and inguinal white adipose tissue (iWAT) metabolism were analyzed by metabolomics and biochemical approaches. The metabolite signature of serum and iWAT significantly changed after 3 weeks of MIX administration, suggesting an improvement in lipid and glucose homeostasis in these animals. In addition, MIX also exhibited significant antihypertensive properties. These results suggest that MIX could be a good candidate to ameliorate the cardiometabolic risk factors related to MetS.

Additive Effects of Omega-3 Fatty Acids and Thiazolidinediones in Mice Fed a High-Fat Diet: Triacylglycerol/Fatty Acid Cycling in Adipose Tissue.

Long-chain n-3 polyunsaturated fatty acids (Omega-3) and anti-diabetic drugs thiazolidinediones (TZDs) exhibit additive effects in counteraction of dietary obesity and associated metabolic dysfunctions in mice. The underlying mechanisms need to be clarified. Here, we aimed to learn whether the futile cycle based on the hydrolysis of triacylglycerol and re-esterification of fatty acids (TAG/FA cycling) in white adipose tissue (WAT) could be involved. We compared Omega-3 (30 mg/g diet) and two different TZDs—pioglitazone (50 mg/g diet) and a second-generation TZD, MSDC-0602K (330 mg/g diet)—regarding their effects in C57BL/6N mice fed an obesogenic high-fat (HF) diet for 8 weeks. The diet was supplemented or not by the tested compound alone or with the two TZDs combined individually with Omega-3. Activity of TAG/FA cycle in WAT was suppressed by the obesogenic HF diet. Additive effects in partial rescue of TAG/FA cycling in WAT were observed with both combined interventions, with a stronger effect of Omega-3 and MSDC-0602K. Our results (i) supported the role of TAG/FA cycling in WAT in the beneficial additive effects of Omega-3 and TZDs on metabolism of diet-induced obese mice, and (ii) showed differential modulation of WAT gene expression and metabolism by the two TZDs, depending also on Omega-3.

Anti-Adipogenic Effect of Theabrownin Is Mediated by Bile Acid Alternative Synthesis via Gut Microbiota Remodeling.

Theabrownin is one of the most bioactive compounds in Pu-erh tea. Our previous study revealed that the hypocholesterolemic effect of theabrownin was mediated by the modulation of bile salt hydrolase (BSH)-enriched gut microbiota and bile acid metabolism. In this study, we demonstrated that theabrownin ameliorated high-fat-diet (HFD)-induced obesity by modifying gut microbiota, especially those with 7α-dehydroxylation on the species level, and these changed microbes were positively correlated with secondary bile acid (BA) metabolism. Thus, altered intestinal BAs resulted in shifting bile acid biosynthesis from the classic to the alternative pathway. This shift changed the BA pool by increasing non-12α-hydroxylated-BAs (non-12OH-BAs) and decreasing 12α-hydroxylated BAs (12OH-BAs), which improved energy metabolism in white and brown adipose tissue. This study showed that theabrownin was a potential therapeutic modality for obesity and other metabolic disorders via gut microbiota-driven bile acid alternative synthesis.

Mild-cold water swimming does not exacerbate white adipose tissue browning and brown adipose tissue activation in mice.

The present study investigated the effects of swimming physical training either thermoneutral or below thermoneutral water temperature on white (WAT) and brown (BAT) adipose tissue metabolism, morphology, and function. C57BL/6J male mice (n = 40; weight 25.3 ± 0.1g) were divided into control (CT30), cold control (CT20), trained (TR30), and cold trained (TR20) groups. Swimming training consisted of 30-min exercise at 30°C (control) or 20°C (cold) water temperature. After 8-week training, adipose tissues were excised and inguinal (ingWAT) and BAT were processed for histology, lipolysis, and protein contents of total OXPHOS, PGC1α, and UCP1 by western blotting analysis. Swimming training reduced body weight gain independently of water temperature (P < 0.05). ingWAT mass was decreased for TR30 in comparison to other groups (P < 0.05), while for BAT, there was a significant increase in CT20 in relation to CT30, and both trained groups were significantly increased in relation to control groups (P < 0.05). ingWAT mean adipocyte area was smaller for trained groups, and seemed to present multilocular adipocytes. Lipolytic activity and protein content of UCP1, PGC1α, and mitochondrial markers were increased in trained groups for ingWAT (P < 0.05), independent of water temperature (P > 0.05), and these patterns were not observed for BAT (P > 0.05). Our findings suggest that mild-cold water exposure and swimming physical exercise seem to, independently, promote browning in ingWAT with no effects on BAT; however, the association of exercise and mild-cold water did not exacerbate these effects.

CD38 downregulation modulates NAD+ and NADP(H) levels in thermogenic adipose tissues

Different strategies to boost NAD+ levels are considered promising means to promote healthy aging and ameliorate dysfunctional metabolism. CD38 is a NAD+-dependent enzyme involved in the regulation of different cell functions. In the context of systemic energy metabolism, it has been demonstrated that brown adipocytes, the parenchymal cells of brown adipose tissue (BAT) as well as beige adipocytes that emerge in white adipose tissue (WAT) depots in response to catabolic conditions, are important to maintain metabolic homeostasis. In this study we aim to understand the functional relevance of CD38 for NAD+ and energy metabolism in BAT and WAT, also using a CD38−/− mouse model.During cold exposure, an increase in NAD+ levels occurred in BAT of wild type mice, together with a marked downregulation of CD38, as detected at the mRNA and protein level. CD38 downregulation was observed also in WAT of cold-exposed mice, where it was accompanied by a strong increase in NADP(H) levels. Accordingly, NAD kinase and glucose-6-phosphate dehydrogenase activities were enhanced in WAT (but not in BAT). Increased NAD+ levels were observed in BAT/WAT from CD38−/− compared with wild type mice, in line with CD38 being a major NAD+-consumer in AT. CD38−/− mice kept at 6 °C had higher levels of Ucp1 and Pgc-1α in BAT and WAT, and increased levels of phosphorylated hormone-sensitive lipase in BAT, compared with wild type mice.These results demonstrate that CD38, by modulating cellular NAD(P)+ levels, is involved in the regulation of thermogenic responses in cold-activated BAT and WAT.

Cajanolactone A, a stilbenoid from cajanus cajan, prevents ovariectomy-induced obesity and liver steatosis in mice fed a regular diet

BackgroundVisceral obesity and fatty liver are prevalent in postmenopausal women. The stilbene-rich extract of Cajanus cajan (L.) Millsp. has been reported to prevent ovariectomy-induced and diet-induced weight gain in animal models, and stilbenoids from C. cajan are thought to have the potential to prevent postmenopausal obesity and fatty liver. PurposeCajanolactone A (CLA) is the main stilbenoid from C. cajan with osteoblastogenic promoting activity. This study investigated the potential of CLA to prevent postmenopausal obesity and fatty liver. Underlying mechanisms were also investigated. MethodOvariectomized C57BL/6 mice fed a regular diet were used as mimics of postmenopausal women and given 10, 20, or 40 mg/kg/d of CLA, 0.1 mg/kg/d of estradiol valerate (EV, positive control), or vehicle (OVX) orally for 16 weeks. Mice of the same age subjected to a sham operation were used as control (Sham). Body weights were recorded every 2 weeks for 16 weeks. Body compositions were analyzed via micro-CT. Serum levels of lipids, adipocytokines and aminotransferases were measured using the relevant kits. mRNA levels of genes of interest were detected by RT-qPCR. Proteomic study of perigonadal white adipose tissue (pWAT) was performed using tandem-mass-tags-based proteomic technology combined with Parallel-Reaction-Monitoring (PRM) validation. ResultsCLA showed potential equivalent to that of EV to prevent ovariectomy-induced overweight, obesity, dyslipidemia, liver steatosis and liver dysfunction, but did not prevent uterine atrophy. In the liver, CLA significantly inhibited ovariectomy-induced upregulation in expression of lipogenic genes SREBP-1c and ChREBP, and stimulated the mRNA expression of apolipoprotein B gene ApoB. In pWAT, CLA reversed, or partially reversed ovariectomy-induced downregulation in the expression of a number of metabolism- and mitochondrial-function-related proteins, including Ndufa3, Pcx, Pdhb, Acly, Acaca, Aldh2, Aacs and Echs1. In addition, ovariectomy-inhibited mRNA expression of Pdhb, Aacs, Acsm5, Echs1, and Aldh2 genes in pWAT was also reversed. ConclusionCLA was demonstrated to be a potential non-estrogen-like drug candidate for prevention of postmenopausal obesity and fatty liver. The underlying mechanism might involve the inhibition of lipogenesis and promotion of triglycerides output in the liver, and the promotion of metabolism and mitochondrial functions of visceral white adipose tissue.

Relationship between white tea and adipose tissue metabolism: The importance and necessity of future research on the effect of white tea on fat oxidation compared to other teas: Letter to the Editor

Obesity is a complex multifactorial disease. The worldwide prevalence of overweight and obesity has doubled since 1980 to an extent that nearly a third of the worldchr('39')s population is now classified as overweight or obese. On the other hand, sports scientists have suggested exercise to prevent further spread of this epidemic. In addition to exercise, the use of natural fat-burning supplements such as green tea was able to attract a lot of people. But recently, white tea in some domestic and foreign research was able to show that like green tea and even better, it will have the potential to burn fat. Therefore, it can be suggested that researchers fill the scientific gap by conducting more research on the comparison of green and white tea and its effects on obesity-related indicators.

The autocrine role of FGF21 in cultured adipocytes.

Exposure to cold alters glucose and lipid metabolism of white and brown adipose tissue via activation of β-adrenergic receptor (ADRB). Fibroblast growth factor 21 (FGF21) has been shown to be locally released from adipose tissue upon activation of ADRBs and FGF21 increases glucose uptake in adipocytes. Therefore, FGF21 may play an autocrine role in inducing glucose uptake after β-adrenergic stimulation. To determine the putative autocrine role of FGF21, we stimulated three different types of adipocytes in vitro with Isoprenaline (Iso), an ADRB agonist, in the presence or absence of the FGF receptor (FGFR) inhibitor PD 173074. The three cell lines represent white (3T3-L1), beige (ME3) and brown (WT-1) adipocyte phenotypes, respectively. All three cells systems expressed β-klotho (KLB) and FGFR1 after differentiation and treatment with recombinant FGF21 increased glucose uptake in 3T3-L1 and WT-1 adipocytes, while no significant effect was observed in ME3. Oppositely, all three cell lines responded to Iso treatment and an increase in glucose uptake and lipolysis were observed. Interestingly, in response to the Iso treatment only the WT-1 adipocytes showed an increase in FGF21 in the medium. This was consistent with the observation that PD 173074 decreased Iso-induced glucose uptake in the WT-1 adipocytes. This suggests that FGF21 plays an autocrine role and increases glucose uptake after β-adrenergic stimulation of cultured brown WT-1 adipocytes.