UCP2 mRNA Research Articles

Effects of resveratrol and its derivative pterostilbene on brown adipose tissue thermogenic activation and on white adipose tissue browning process.

The main function of brown adipose tissue (BAT) is thermogenesis, a process mediated by uncoupling protein 1 (UCP1), which is located in the inner mitochondrial membrane and acts uncoupling oxidative phosphorylation from ATP production, thereby dissipating energy as heat. White adipose tissue can also express UCP1 positive cells due to a process known as browning. This phenomenon could also increase the thermogenic effect in the classical brown adipose depots. BAT thermogenesis depends, among other factors on both, nutritional conditions and food availability. Indeed, some studies have found that BAT recruitment and function are enhanced by some food components. The present study focuses on the effects of resveratrol and pterostilbene, two phenolic compounds belonging to the stilbene group, on BAT thermogenic activation and white adipose tissue browning process. The reported studies, carried out in cell cultures and animal models, show that both resveratrol and pterostilbene induce thermogenic capacity in interscapular BAT by increasing mitochondriogenesis, as well as enhancing fatty acid oxidation and glucose disposal. In addition, resveratrol seems to promote browning by activating peroxisome proliferator-activated receptor (PPAR), while the lack of changes in mitochondrial biogenesis suggests that probably the browning process occurs by direct resveratrol-mediated upregulation of ucp1 mRNA expression.

The generation of immune-induced fever and emotional stress-induced hyperthermia in mice does not involve brown adipose tissue thermogenesis.

We examined the role of brown adipose tissue (BAT) for fever and emotional stress-induced hyperthermia. Wild-type and uncoupling protein-1 (UCP-1) knockout mice were injected with lipopolysaccharide intraperitoneally or intravenously, or subjected to cage exchange, and body temperature monitored by telemetry. Both genotypes showed similar febrile responses to immune challenge and both displayed hyperthermia to emotional stress. Neither procedure resulted in the activation of BAT, such as the induction of UCP-1 or peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) mRNA, or reduced BAT weight and triglyceride content. In contrast, in mice injected with a β3 agonist, UCP-1 and PGC-1α were strongly induced, and BAT weight and triglyceride content reduced. Both lipopolysaccharide and the β3 agonist, and emotional stress, induced UCP-3 mRNA in skeletal muscle. A β3 antagonist did not attenuate lipopolysaccharide-induced fever, but augmented body temperature decrease and inhibited BAT activation when mice were exposed to cold. An α1 /α2b antagonist or a 5HT1A agonist, which inhibit vasoconstriction, abolished lipopolysaccharide-induced fever, but had no effect on emotional stress-induced hyperthermia. These findings demonstrate that in mice, UCP-1-mediated BAT thermogenesis does not take part in inflammation-induced fever, which is dependent on peripheral vasoconstriction, nor in stress-induced hyperthermia. However, both phenomena may involve UCP-3-mediated muscle thermogenesis.

Inhibition of Uncoupling Protein 2 Enhances the Radiosensitivity of Cervical Cancer Cells by Promoting the Production of Reactive Oxygen Species.

Objective The mechanism of enhanced radiosensitivity induced by mitochondrial uncoupling protein UCP2 was investigated in HeLa cells to provide a theoretical basis as a novel target for cervical cancer treatment. Methods HeLa cells were irradiated with 4 Gy X-radiation at 1.0 Gy/min. The expression of UCP2 mRNA and protein was assayed by real-time quantitative polymerase chain reaction and western blotting. UCP2 siRNA and negative control siRNA fragments were constructed and transfected into HeLa cells 24 h after irradiation. The effect of UCP2 silencing and irradiation on HeLa cells was determined by colony formation, CCK-8 cell viability, γH2AX immunofluorescence assay of DNA damage, Annexin V-FITC/PI apoptosis assay, and propidium iodide cell cycle assay. The effects on mitochondrial structure and function were investigated with fluorescent probes including dichlorodihydrofluorescein diacetate (DCFH-DA) assay of reactive oxygen species (ROS), rhodamine 123, and MitoTracker Green assay of mitochondrial structure and function. Results Irradiation upregulated UCP2 expression, and UCP2 knockdown decreased the survival of irradiated HeLa cells. UCP2 silencing sensitized HeLa cells to irradiation-induced DNA damage and led to increased apoptosis, cell cycle arrest in G2/M, and increased mitochondrial ROS. Increased radiosensitivity was associated with an activation of P53, decreased Bcl-2, Bcl-xl, cyclin B, CDC2, Ku70, and Rad51 expression, and increased Apaf-1, cytochrome c, caspase-3, and caspase-9 expression. Conclusions UCP2 inhibition augmented the radiosensitivity of cervical cancer cells, and it may be a potential target of radiotherapy of advanced cervical cancer.

PPARγ and PPARα synergize to induce robust browning of white fat in vivo

ObjectivePeroxisome proliferator-activated receptors (PPARs) are key transcription factors that regulate adipose development and function, and the conversion of white into brown-like adipocytes. Here we investigated whether PPARα and PPARγ activation synergize to induce the browning of white fat. MethodsA selection of PPAR activators was tested for their ability to induce the browning of both mouse and human white adipocytes in vitro, and in vivo in lean and obese mice. ResultsAll dual PPARα/γ activators tested robustly increased uncoupling protein 1 (Ucp1) expression in both mouse and human adipocytes in vitro, with tesaglitazar leading to the largest Ucp1 induction. Importantly, dual PPARα/γ activator tesaglitazar strongly induced browning of white fat in vivo in both lean and obese male mice at thermoneutrality, greatly exceeding the increase in Ucp1 observed with the selective PPARγ activator rosiglitazone. While selective PPARγ activation was sufficient for the conversion of white into brown-like adipocytes in vitro, dual PPARα/γ activation was superior to selective PPARγ activation at inducing white fat browning in vivo. Mechanistically, the superiority of dual PPARα/γ activators is mediated at least in part via a PPARα-driven increase in fibroblast growth factor 21 (FGF21). Combined treatment with rosiglitazone and FGF21 resulted in a synergistic increase in Ucp1 mRNA levels both in vitro and in vivo. Tesaglitazar-induced browning was associated with increased energy expenditure, enhanced insulin sensitivity, reduced liver steatosis, and an overall improved metabolic profile compared to rosiglitazone and vehicle control groups. ConclusionsPPARγ and PPARα synergize to induce robust browning of white fat in vivo, via PPARγ activation in adipose, and PPARα-mediated increase in FGF21.

Long non-coding RNA 2310069B03Rik functions as a suppressor of Ucp1 expression under prolonged cold exposure in murine beige adipocytes.

Specific conditions, such as exposure to cold, can induce the production of brown-like adipocytes in white adipose tissue. These adipocytes express high levels of uncoupling protein 1 (UCP1) and energy expended by generating heat. Thus, these are a potential target for the prevention or treatment of obesity. The present study involved a comprehensive analysis of the adipose tissue to understand the relationship between long non-coding RNA (lncRNA) 2310069B03Rik and UCP1. Cold exposure increased both lncRNA 2310069B03Rik and Ucp1 expression in inguinal white adipose tissue (iWAT). However, overexpression of lncRNA 2310069B03Rik suppressed the Ucp1 mRNA expression and the promoter activity of UCP1 in the iWAT primary adipocytes. In addition, compared to the early induction of Ucp1 expression by cold stimulation, the induction of lncRNA 2310069B03Rik expression was later. These results suggest that lncRNA 2310069B03Rik functions as a suppression factor of Ucp1 expression.

Glucose metabolism in brown adipose tissue determined by deuterium metabolic imaging in rats.

Brown adipose tissue (BAT) has gained growing interest as a potential target for treatment of obesity. Currently, the most widely used technique/method for in vivo measurements of BAT activity in humans is 18FDG PET/CT. To supplement these investigations novel radiation-free methods are warranted. Deuterium metabolic imaging (DMI) is a novel modality that combines magnetic resonance spectroscopic (MRS) imaging with deuterium-labelled glucose (2H-glucose). This allows for spatio-temporal and metabolic imaging beyond glucose uptake. We aimed to evaluate if DMI could discriminate glucose metabolism in BAT of cold-acclimatised and thermoneutral rats. Male Sprague-Dawley rats were housed in a cold environment (9 °C, n = 10) or at thermoneutrality (30 °C, n = 11) for 1 week. For imaging rats were anaesthetized, received a 2H-glucose (1 M, 1.95 g/kg) bolus and DMI was acquired at baseline followed by 20 min time intervals up to 2 h. Furthermore, Dixon MRI was performed for anatomical determination of the interscapular BAT (iBAT) depot along with dynamic contrast enhanced (DCE) MRI to evaluate perfusion. 2H-glucose signal was higher in cold-acclimatised rats compared with thermoneutral rats (p ≤ 0.001) indicating an overall increase in glucose uptake and metabolism. This was in line with a lower fat/water threshold, higher perfusion and increased UCP1 mRNA expression in iBAT (ninefold increment) of cold-acclimatised rats compared with thermoneutral rats. We find that DMI can discriminate cold-acclimatised and thermoneutral BAT in rats. This is the first study to evaluate BAT activity by DMI, which may open up for the use of the non-radioactive DMI method for BAT measurements in humans.

STAT5 ablation in AgRP neurons increases female adiposity and blunts food restriction adaptations.

AgRP neurons are important players in the control of energy homeostasis and are responsive to several hormones. In addition, STAT5 signalling in the brain, which is activated by metabolic hormones and growth factors, modulates food intake, body fat and glucose homeostasis. Given that, and the absence of studies that describe STAT5 function in AgRP cells, the present study investigated the metabolic effects of Stat5a/b gene ablation in these neurons. We observed that STAT5 signalling in AgRP neurons regulates body fat in female mice. However, male and female STAT5-knockout mice did not exhibit altered food intake, energy expenditure or glucose homeostasis compared to control mice. The counter-regulatory response or glucoprivic hyperphagia induced by 2-deoxy-d-glucose treatment were also not affected by AgRP-specific STAT5 ablation. However, under 60% food restriction, AgRP STAT5-knockout mice had a blunted upregulation of hypothalamic Agrp mRNA expression and corticosterone serum levels compared to control mice, suggesting a possible role for STAT5 in AgRP neurons for neuroendocrine adaptations to food restriction. Interestingly, ad libitum fed knockout male mice had reduced Pomc and Ucp-1 mRNA expression compared to control group. Taken together, these results suggest that STAT5 signalling in AgRP neurons regulates body adiposity in female mice, as well as some neuroendocrine adaptations to food restriction.

Leptin: Is It Thermogenic?

Animals that lack the hormone leptin become grossly obese, purportedly for 2 reasons: increased food intake and decreased energy expenditure (thermogenesis). This review examines the experimental evidence for the thermogenesis component. Analysis of the data available led us to conclude that the reports indicating hypometabolism in the leptin-deficient ob/ob mice (as well as in the leptin-receptor-deficient db/db mice and fa/fa rats) derive from a misleading calculation artefact resulting from expression of energy expenditure per gram of body weight and not per intact organism. Correspondingly, the body weight-reducing effects of leptin are not augmented by enhanced thermogenesis. Congruent with this, there is no evidence that the ob/ob mouse demonstrates atrophied brown adipose tissue or diminished levels of total UCP1 mRNA or protein when the ob mutation is studied on the inbred C57BL/6 mouse background, but a reduced sympathetic nerve activity is observed. On the outbred “Aston” mouse background, brown adipose tissue atrophy is seen, but whether this is of quantitative significance for the development of obesity has not been demonstrated. We conclude that leptin is not a thermogenic hormone. Rather, leptin has effects on body temperature regulation, by opposing torpor bouts and by shifting thermoregulatory thresholds. The central pathways behind these effects are largely unexplored.

Long-Term Potable Effects of Alkalescent Mineral Water on Intestinal Microbiota Shift and Physical Conditioning.

Background An alkalescent (pH 8.3) mineral water (AMW) of Hita basin, located in the northwestern part of Kyushu island in Japan, has been recognized for the unique quality of ingredients including highly concentrated silicic acid, sodium, potassium, and hydrogen carbonate. The biological effects of AMW intake were evaluated with a particular focus on its “antiobesity” properties through its modulation of the gut microbiota population. Methods Two groups of C57BL6/J mice (8-week-old male) were maintained with a standard diet and tap water (control: TWC group) or AMW (AMW group) for 6 months and the following outputs were quantitated: (1) food and water intake, (2) body weight (weekly), (3) body fat measurements by CT scan (monthly), (4) sera biochemical values (TG, ALT, AST, and ALP), and (5) UCP-1 mRNA in fat tissues (terminal point). Two groups of ICR mice (7-week-old male) were maintained with the same method and their feces were collected at the 0, 1st, 3rd, and 6th month at which time the population rates of gut microbiota were quantitated using metagenomic sequencing analysis of 16S-rRNA. Results Among all antiobesity testing items, even though a weekly dietary consumption was increased (p=0.012), both ratios of weight gain (p=1.21E − 10) and visceral fat accumulation (p=0.029) were significantly reduced in the AMW group. Other criteria including water intake (p=0.727), the amounts of total (p=0.1602), and subcutaneous fat accumulation (p=0.052) were within the margin of error and UCP-1 gene expression level (p=0.171) in the AMW group was 3.89-fold higher than that of TWC. Among 8 major gut bacteria families, Lactobacillaceae (increased, p=0.029) and Clostridiaceae (decreased, p=0.029) showed significant shift in the whole population. Conclusion We observed significantly reduced (1) weight gaining ratio (average −1.86%, up to −3.3%), (2) visceral fat accumulation ratio (average −4.30%, up to −9.1%), and (3) changes in gut microbiota population. All these consequences could support the “health benefit” functionality of AMW.

Recombinant irisin induces weight loss in high fat DIO mice through increase in energy consumption and thermogenesis

ObjectiveIrisin is known to be an important metabolic regulator of glucose and lipid metabolism. The aims of the present study are to assess the role of mouse Irisin in obesity and energy metabolism and its glucose and lipid-lowering effects in a high-fat diet-induced obesity (DIO) mice model. MethodsDIO mice were treated with recombinant murine Irisin or vehicle, and parameters such as body weight, feed intake, glucose, and lipid levels, obesity, energy consumption, and insulin sensitivity were assessed. mRNA and protein levels of UCP1 and different thermogenesis biomarker were evaluated by quantitative real-time PCR and Western blot, respectively, in tissues and major metabolic organs. ResultsIrisin decreased body weight and whole-body fat mass in DIO mice in a dose dependent manner due to marked increases in total energy expenditure. It also lowered blood glucose, insulin, and lipid levels and possibly reversed hepatic steatosis. Irisin improved hepatic and peripheral insulin sensitivity in DIO mice along with body weight reduction and adiposity. Gene expression of UCP1 in different organs (adipose tissue and major organs, i.e., liver, kidney, heart, brain, and spleen) have suggested the role of irisin is global. Gene expression profile of different biomarkers in spleen suggest a profound role of Irisin in inflammation. Liver tissue have also shown significant increase of UCP1 expression in dose dependent manner which suggest a role of irisin in liver.

Microglial UCP2 Mediates Inflammation and Obesity Induced by High-Fat Feeding

Microglia play a crucial role in immune responses, including inflammation. Diet-induced obesity (DIO) triggers microglia activation and hypothalamic inflammation as early as 3days after high-fat diet (HFD) exposure, before changes in body weight occur. The intracellular mechanism(s) responsible for HFD-induced microglia activation is ill defined. Here, we show that invivo, HFD induced a rapid and transient increase in uncoupling protein 2 (Ucp2) mRNA expression together with changes in mitochondrial dynamics. Selective microglial deletion of Ucp2 prevented changes in mitochondrial dynamics and function, microglia activation, and hypothalamic inflammation. In association with these, male and female mice were protected from HFD-induced obesity, showing decreased feeding and increased energy expenditure that were associated with changes in the synaptic input organization and activation of the anorexigenic hypothalamic POMC neurons and astrogliosis. Together, our data point to a fuel-availability-driven mitochondrial mechanism as a major player of microglia activation in the central regulation of DIO.

Anti-obesity effect of Yangkyuksanwha-tang in high-fat diet-induced obese mice

BackgroundYangkyuksanwha-tang (YST) is an herbal medicine based on Sasang constitutional medicine (SCM) and is widely used in Korean traditional medicine. The aim of the study was to evaluate the effect of YST on obesity in high-fat diet (HFD)-induced obese mice.MethodsWe induced obesity in C57bl/6 J mice using a HFD, and then orally administered 300 mg/kg YST for 6 weeks. We measured body weight, food efficiency, organ and fat weight, serum biochemical parameters, and obesity-related gene expression, and carried out histological analysis at the end of the experimental period.ResultsYST significantly reduced the absolute body weight and food efficiency ratio. The serum, aminotransferase, glucose, total cholesterol, triglyceride, and low-density lipoprotein-cholesterol levels were significantly lower in the YST-treated group than in the control group, whereas the high-density lipoprotein-cholesterol level in the YST-treated group was significantly higher. The YST-treated group also showed a significant reduction in regional fatty tissues and the absolute weight of various organs. We also observed a significantly reduced expression of AP2/FABP4, C/EBP-β, leptin, and SREBP1c/ADD1 mRNA, and significantly increased expression of UCP-2 and adiponectin mRNA in adipose tissue in the YST-treated group. YST also decreased the lipid droplet size and lipid accumulation in the liver, as well as adipocyte size in epididymal adipose tissue. At the dose tested, YST was non-toxic to the liver and kidneys of the mice.ConclusionThe results imply that YST has anti-obesity effects in obesity-induced mice. Although the number of experimental animals was limited and the drug effects concern mice, rather than humans, which have different constitutions, the study has valuable implications with respect to the general effects of YST.

Antioxidant-upregulated mesenchymal stem cells reduce inflammation and improve fatty liver disease in diet-induced obesity

BackgroundThe incidence of obesity and diabetes is increasing rapidly. Optimal management is still elusive. Obesity associated with type 2 diabetes is known to cause adipose tissue inflammation, increase oxidative stress, and cause white fat hyperplasia and mitochondrial dysfunction. In this study, we investigated whether mitochondrial and cytosolic antioxidant-upregulated mesenchymal stem cell (MSC) delivery reduces oxidative stress and subsequently improves glucose tolerance, reduce systemic inflammation, and improves fatty liver disease in diet-induced obese (DIO) mouse models.MethodsAntioxidant genes Sod2 (mitochondrial) and catalase (cytosolic) or null (control) were upregulated in human adipose tissue-derived MSCs using adenoviral constructs. Modified MSCs were then delivered intraperitoneally into mice that were fed a 45% or 60% high-fat diet (HFD), and animals were followed for 4 weeks.ResultsOver 4 weeks, body weight remained stable; however, we noted a significant reduction in liver fat content by histological analysis and liver triglyceride assay. Triglyceride assay (p < 0.01) confirmed reduced liver fat accumulation in animals that received either Sod2- or Cat-MSCs. There was a lower plasma level of inflammatory marker TNFα, measured in mice that were fed either 45% or 60% HFD and received Sod2- or Cat-MSCs, indicating reduced systemic inflammation. Ucp1 mRNA was upregulated approximately 100–1000-fold for omental fat and 10–100-fold for pericardial fat compared to the Null-MSC-receiving group. Pcgc1a and Prdm16 mRNA upregulation was also noted particularly for pericardial fat. Glucose tolerance showed a positive improvement trend with a lower area under the curve (AUC) values for both Sod2- and Cat-MSCs groups in comparison to control. For mice fed with 60% HFD and that received Sod2-MSCs, glucose levels were significantly lower than control (*p < 0.05) at a time point of 60 min in the glycemic curve during glucose tolerance test.ConclusionReduction of oxidative stress post-antioxidant-upregulated MSC delivery, intraperitoneally, reduces systemic inflammation and fat accumulation in the liver. There is evidence of an increase in browning of white adipose tissue depots with concomitant improvement of glucose tolerance in a weight-independent fashion. Antioxidant-upregulated MSC delivery may be a safe yet effective therapy for obesity and prediabetes and improves related complication such as non-alcoholic fatty liver disease.

β-Cryptoxanthin Induces UCP-1 Expression via a RAR Pathway in Adipose Tissue

While β-cryptoxanthin is hypothesized to have a preventive effect on lifestyle-related diseases, its underlying mechanisms are unknown. We investigated the effect of β-cryptoxanthin on energy metabolism in adipose tissues and its underlying mechanism. C57BL/6J mice were fed a high-fat diet (60% kcal fat) containing 0 or 0.05% β-cryptoxanthin for 12 weeks. β-cryptoxanthin treatment was found to reduce body fat gain and plasma glucose level, while increasing energy expenditure. The expression of uncoupling protein (UCP) 1 was elevated in adipose tissues in the treatment group. Furthermore, the in vivo assays showed that the Ucp1 mRNA expression was higher in the β-cryptoxanthin treatment group, an effect that disappeared upon cotreatment with a retinoic acid receptor (RAR) antagonist. In conclusion, we report that β-cryptoxanthin reduces body fat and body weight gain and that β-cryptoxanthin increases the expression of UCP1 via the RAR pathway.

Physical training, UCP1 expression, mitochondrial density, and coupling in adipose tissue from women with obesity.

Exercise training may improve energy expenditure, thermogenesis, and oxidative capacities. Therefore, we hypothesized that physical training enhances white adipose tissue mitochondrial oxidative capacity from obese women. To evaluate mitochondrial respiratory capacity, mitochondrial content, and UCP1 gene expression in white adipose tissue from women with obesity before and after the physical training program. Women (n=14, BMI 33±3kg/m2 , 35±6years, mean±SD) were submitted to strength and aerobic exercises (75%-90% maximum heart rate and multiple repetitions), 3times/week during 8weeks. All evaluated subjects were paired, before and after training for resting metabolic rate (RMR), substrate oxidation (lipid and carbohydrate) by indirect calorimeter, deuterium oxide body composition, and aerobic maximum velocity (Vmax ) test. At the beginning and at the ending of the protocol, abdominal subcutaneous adipose tissue was collected to measure the mitochondrial respiration by high-resolution respirometry, mitochondrial content by citrate synthase (CS) activity, and UCP1 gene expression by RT-qPCR. Combined physical training increased RMR, lipid oxidation, and Vmax but did not change body weight/composition. In WAT, exercise increased CS activity, decreased mitochondrial uncoupled respiration and mRNA of UCP1. RMR was positively correlated with fat-free mass. Physical training promotes an increase in mitochondrial content without changing tissue respiratory capacity, a reduction in mitochondrial uncoupling degree and UCP1 mRNA expression in WAT. Finally, it improved the resting metabolic rate, lipid oxidation and physical performance, independent of the body changing free, or fat mass in obese women.

ANGIOTENSIN II INDUCES UCP1 IN ADIPOSE TISSUE OF AN EXPERIMENTAL MODEL OF CARDIO-RENAL CACHEXIA

Objective: Cachexia is a severe complication of advanced heart failure and chronic kidney disease. We previously reported that high dose Angiotensin II infusion in rats determined body weight reduction, prevented by an AT-1 receptor blocker treatment and beta-adrenergic non selective antagonism. The possible role of Ang II on UCP1 in white and brown adipose tissue, as a possible mechanism, was investigated in this study. Design and method: Male Sprague-Dawley rats, were implanted subcutaneously in the dorsal region with osmotic minipumps delivering Ang-II at high doses (525 ng/Kg/min) for 12 days to mimic heart failure and the development of cachexia. Five concurrent groups of rats were evaluated: 1) vehicle–infused rats (CTR-rat, n = 9); 2) Ang-II infused rats (n = 7); Ang- II rats receiving by oral gavage 2 days before minipump implantation until the 12th day of Ang-II infusion, either 3) bisoprolol (BIS,β1-adrenergic antagonist, 35 mg/Kg/day, n = 5), or 4) carvedilol (CVD,α1-non-selective-β1,2,3-adrenergic blocker, 90 mg/kg/day, n = 5) or 5) bupranolol (BPR,β3-antagonist, 200 mg/day/kg, n = 4). White adipose tissue (WATs) from retroperitoneal (RWAT), epidydimal (EWAT), dorsal (DWAT) and brown interscapular (IBAT) depot were withdrawn in order to determine UCP1 mRNA expression, norepinephrine tissue level (TNE) and tyrosine hydroxylase activity (THA) Results: THA and TNE were higher in Ang-II infused rats in all the white adipose tissue depots analyzed. CVD prevented TNE increase in all WATs, while BPR and BIS were effective in RWAT and EWAT but not DWAT. All the three beta adrenergic blocker treatments significantly reduced THA increased activity related to Ang-II infusion in all the WATs. UCP1 mRNA was increased in IBAT (+39%, p < 0.05) of Ang II-infused rat, significantly prevented by CVD and BPR but not by BIS. UCP1 was also increased in all the three WATs of Ang-II infused rats, with all the three beta blockers able to reduce the effect in RWAT and DWAT. No effect of beta-blockers treatment was observed in EWAT. Conclusions: High dose angiotensin II infusion determined an increase in UCP1 trascription in brown and white adipose tissue in rats. CVD and BPR were able to prevent UCP1 increase in brown and white adipose tissue more than beta-1 selective antagonist BIS.

Islet β-cell-produced NUCB2/nesfatin-1 maintains insulin secretion and glycemia along with suppressing UCP-2 in β-cells.

Nesfatin-1 is a hypothalamic anorexigenic peptide processed from nucleobindin 2 (NUCB2). Central and peripheral administration of NUCB2/nesfatin-1 enhances glucose metabolism and insulin release. NUCB2/nesfatin-1 is also localized in pancreatic islets, while its function remains unknown. To explore the role of pancreatic β-cell-produced NUCB2/nesfatin-1, we developed pancreatic β-cell-specific NUCB2 knockout (βNUCB2 KO) mice and NUCB2 gene knockdown (shNUCB2) MIN6 β-cell line. In βNUCB2 KO mice, casual blood glucose was elevated from 12weeks of age. In a glucose tolerance test at 12weeks, insulin secretion at 15min was reduced and blood glucose at 2h increased in βNUCB2 KO mice fasted 8h. In islets isolated from βNUCB2 KO mice, high glucose-stimulated insulin secretion (GSIS) was impaired. In shNUCB2 MIN6 cells, GSIS was reduced and UCP-2 mRNA expression was elevated. These results show impaired GSIS possibly associated with UCP-2 overexpression in NUCB2-silenced β-cells, suggesting that β-cell-produced NUCB2/nesfatin-1 maintains GSIS and thereby glycemia.

Interaction between the amount of dietary protein and the environmental temperature on the expression of browning markers in adipose tissue of rats

BackgroundA low-protein diet increases the expression and circulating concentration of FGF21. FGF21 stimulates the browning process of WAT by enhancing the expression of UCP1 coupled with an increase in PGC1α. Interestingly, the consumption of a low-protein diet could stimulate WAT differentiation into beige/brite cells by increasing FGF21 expression and Ucp1 mRNA abundance. However, whether the stimulus of a low-protein diet on WAT browning can synergistically interact with another browning stimulus, such as cold exposure, remains elusive.ResultsIn the present study, rats were fed 6% (low), 20% (adequate), or 50% (high) dietary protein for 10 days and subsequently exposed to 4 °C for 72 h. Body weight, food intake, and energy expenditure were measured, as well as WAT browning and BAT thermogenesis markers and FGF21 circulating levels. The results showed that during cold exposure, the consumption of a high-protein diet reduced UCP1, TBX1, Cidea, Cd137, and Prdm16 in WAT when compared with the consumption of a low-protein diet. In contrast, at room temperature, a low-protein diet increased the expression of UCP1, Cidea, and Prdm16 associated with an increase in FGF21 expression and circulating levels when compared with a consumption of a high-protein diet. Consequently, the consumption of a low-protein diet increased energy expenditure.ConclusionsThese results indicate that in addition to the environmental temperature, WAT browning is nutritionally modulated by dietary protein, affecting whole-body energy expenditure.Graphical abstract

2034-P: The Role of 14-3-3zeta in the “Beiging” of White Adipose Tissue

Adipocyte hypertrophy and hyperplasia is a hallmark of obesity, and treatments that induce the oxidation of lipid stores may represent a potential therapy. When stimulated by cold or beta-adrenergic agonists, adipocytes in inguinal white adipose tissue (iWAT) can convert to beige cells, which resemble brown adipocytes. This process can reduce body weight in rodents and improve glucose homeostasis through increased Ucp1-dependent lipid oxidation. 14-3-3?, a molecular scaffold we found to be essential for adipogenesis, regulates the enzymatic activities of tryptophan and tyrosine hydroxylases, both of which influence beiging. Thus, the aim of the current study is to investigate whether 14-3-3? influences the beiging process. Compared to control mice, acute (3 hr) and chronic (72 hr) cold (4 C) exposure in male transgenic mice over-expressing 14-3-3? led to improved cold tolerance due to significantly increased Ucp1 mRNA and protein in iWAT. Following chronic exposure, they were also able to maintain their body weight by increasing their food intake. Consistent with these data, analysis of adipocyte area revealed a decrease in the size of inguinal adipocytes in transgenic mice, suggesting increased lipid oxidation. In contrast, gonadal adipocytes were larger in transgenic mice, which may explain their ability to maintain their body weight. Systemic 14-3-3? knockout mice had significantly lower levels of Ucp1 mRNA in iWAT and BAT but did not display differences in tolerance to acute cold. Depletion of 14-3-3? by siRNA in brown adipocytes did not impair isoproterenol-mediated induction of Ucp1 mRNA, suggesting that 14-3-3? is not required for Ucp1 expression in this cell type. In future studies, we will examine if 14-3-3? influences the responsiveness of iWAT to chronic β-adrenergic stimuli and assess the impact of 14-3-3? overexpression in brown adipocyte function. Collectively, our results point to a novel role of 14-3-3? in the beiging of inguinal adipocytes and increase our understanding of how beiging is regulated. Disclosure K. Diallo: None. G.E. Lim: None. Funding Canadian Institutes of Health Research; Fonds de la recherche en santé du Québec; Centre de recherche du CHUM; Montreal Diabetes Research Center

1857-P: Modified Mesenchymal Stromal Cells: A Novel and Safe Therapy for Treating Nonalcoholic Fatty Liver Disease (NAFLD) in Obesity and Diabetes

Background: Mesenchymal stromal cells (MSCs) can home-in to inflamed fat depots to deliver antioxidants locally and help reduce oxidative stress, inflammation and improve NAFLD in high-fat diet (HFD) induced obese (DIO) diabetic mice. Methods: Antioxidants Sod2 (mitochondrial), Catalase (cytosolic) or Null (control) genes were upregulated individually, or in combination in adipose-derived MSCs. Modified MSCs were examined in-vitro in presence of adipogenic media to mimic DIO milieu. Next, modified MSCs were delivered intraperitoneally (IP) in mice that received 45% or 60% HFD for 8 to16 weeks. Results: In-vitro, we noted reduced MSC lipid droplets with SOD2, Catalase and combination compared to Null. Inflammatory marker IL6 mRNA, was down-regulated in SOD2, Cat and combination MSCs vs. Null-MSCs. In-vivo, n=4, Glucose tolerance test (GTT) improved with SOD2 MSC delivery in (p=0.07) at week-4. Plasma inflammatory marker TNFa, was reduced in both SOD2 and Catalase MSC groups (p&amp;lt;0.05) vs. Null-MSCs group. Analysis of omental and pericardial fat showed significant up-regulation in mRNA expression of brown fat marker, Ucp1 (∼1000 and 100-fold, respectively) and PGC1A mRNA was upregulated. Increased Ucp1 was confirmed by staining. There was a reduction in liver fat content by histology and liver triglyceride assay (p&amp;lt;0.05). Outcome measures of SOD2+Catalase combination MSC delivery in-vivo is pending. Conclusion: Upregulation of SOD2 plus Catalase, in-vitro, reduced inflammation in adipogenic media more so than individual gene upregulation. In-vivo, delivery of Sod2 and Catalase upregulated individually in MSCs, reduced inflammation and improved GTT with concomitant increased browning of white fat and reduced liver fat. Our results indicate that antioxidant upregulated modified MSC delivery IP, to target inflamed fat depots helps reduce oxidative stress and inflammation and can be an efficient tool for treating obesity, diabetes and NAFLD. Disclosure C.C. Domingues: None. N. Kundu: None. Y. Kropotova: None. S. Sen: None. Funding Clinical and Translational Science Institute at Children's National