UCP1 Protein Research Articles

Effects of alternate-day modified fasting combined exercise on fat reducing and the FNDC5/Irisin-UCP1 pathway

The effects of Alternate-day modified fasting combined exercise on fat mass, muscle mass, and serum Irisin, FNDC5 and UCP1 proteins were investigated in rats with 4 weeks of aerobic exercise and modified alternate-day fasting intervention. Thirty-two healthy 8-week-old SPF male SD rats were randomly divided into control group, exercise group, alternate-day modified fasting and alternate-day modified fasting combined with exercise group, 8 rats in each group. The exercise group performed treadmill exercise with moderate exercise intensity(60 min/d,5 d/w), the alternate-day modified fasting group alternated between fasting and free feeding every other day, and fed 25% basal energy feed on fasting days, and the alternate-day modified fasting combined exercise group received two combined interventions. After 4 weeks of intervention, the body fat rate of rats was measured by apical blood sampling and abdominal aortic blood sampling, and the serum was preserved and centrifuged, and the wet weights of bilateral gastrocnemius, bilateral perirenal fat and brown fat at the scapula were weighed, and samples were collected for paraffin sectioning and HE staining, and the cell areas were counted; serum Irisin levels were measured by ELISA, and FNDC5 protein expression in gastrocnemius and UCP1 protein expression in adipose tissue were detected by Western blot. After 4 weeks of intervention, compared with the Con group, energy intake, body weight and body fat were decreased significantly in the Exer, ADMF and ADMF-Exer groups (P＜0.05), the wet weight/body weight and adipocyte area of white fat were reduced significantly (P＜0.01), and there was no significant difference in scapular fat wet weight/body weight (P＞0.05). Compared with the Con group, the gastrocnemius wet weight/body weight in the ADMF group was reduced significantly (P＜0.05), while that in the ADMF-Exer group was increased significantly (P＜0.05), the muscle cross-sectional areas in the Exer group and the ADMF-Exer group were increased (P＜0.05), and the content of gastrocnemius FNDC5 protein, serum Irisin level and expression of adipose UCP1 protein in the ADMF-Exer group were increased significantly (P＜0.05). After 4 weeks of intervention, energy intake was reduced significantly in both ADMF and ADMF-Exer groups (P＜0.01) and body weight of ADMF-Exer group was decreased (P＜0.05) compared with the Exer group. Compared with the Exer group, there were no significant differences in body fat content, white fat wet weight/body weight and scapular fat wet weight/body weight between ADMF group and ADMF-Exer group (P＞0.05), and adipocyte area in ADMF-Exer group was reduced significantly (P＜0.05). Compared with the Exer group, the gastrocnemius muscle wet weight/body weight was reduced significantly in the ADMF group (P＜0.05), and the expression of FNDC5 protein, serum Irisin and adipose UCP1 protein in the ADMF-Exer group were increased significantly compared with the Exer group (P＜0.05). Alternate-day modified fasting combined with exercise intervention can effectively control body weight and reduce body fat in rats, and the mechanism may be through the FNDC5/Irisin-UCP1 pathway to induce browning of white adipose tissue and increase thermogenesis of brown fat.

Irisin promotes the browning of white adipocytes tissue by AMPKα1 signaling pathway

The development of white adipose tissue (WAT) browning helps to protect animals from cold conditions and prevent obesity. AMPKα1 has been involved in the process of white adipocytes browning. Although Irisin plays a vital role in the browning of WAT, the detailed regulatory mechanism of Irisin inducing the browning of WAT remains unclear. Herein, we firstly investigated the potential roles of differentiation and Irisin in regulating the browning of 3T3-L1 cells. The results found that they could significantly increase the number of lipid droplets and upregulate the expression levels of UCP1, PGC-1α, PRDM16, and p-AMPKα1. Then we proved the effectiveness of the AMPKα1 signaling pathway in the process of Irisin inducing the browning of 3T3-L1 cells. Compared with si-NC, si-AMPKα1 not only decreased the number of Irisin-induced lipid droplets, but also attenuated the expression of Irisin-induced UCP1, PGC-1α, and PRDM16 protein and mRNA levels in 3T3-L1 cells. Furthermore, the results showed that Irisin increased the positive distribution of UCP1 and PGC-1α, and upregulated the expression of UCP1, PGC-1α, and PRDM16 at both protein and mRNA levels in WAT. Once siRNA treated mice, the facilitation of Irisin on UCP1 and PGC-1α in si-AMPKα1-injected mice was lower than that in si-NC-injected mice. Compared with si-NC, si-AMPKα1 significantly downregulated the expression of UCP1, PGC-1α, and PRDM16 in Irisin-injected mice. Taken together, our results demonstrate that Irisin activates the AMPKα1 pathway to promote the browning of WAT by upregulating the mRNA and protein levels of UCP1, PGC-1α, and PRDM16.

Biological targets of berberine hydrochloride and the mechanisms by which it alleviates metabolic-associated fatty liver disease

<p indent="0mm">Metabolic-associated fatty liver disease (MAFLD) is a common disease worldwide and is closely related to cardiovascular disease, obesity, diabetes and other metabolic diseases. However, there is no efficient medication available yet. Researches on potential drugs, including antioxidants, insulin sensitizers and lipid-lowering drugs, have indicated that these drugs are effective in reducing the liver fat content and some histological lesions but have limited effects in alleviating liver fibrosis. Berberine hydrochloride (BBR) is an isoquinoline alkaloid derived from many medicinal plants. It was used as an anti-diarrhoea drug in the early stage. However, a large number of studies have shown that it has rich pharmacological effects in the protection against cardiovascular diseases, cancers and other aspects. Increasing evidence has indicated that BBR can regulate metabolism and has beneficial effects on MAFLD. In the target organ of the liver, BBR can activate AMPK by regulating the phosphorylation of AMPK. This phosphorylation inhibits the expression of downstream genes related to lipid synthesis and metabolism, and thus improves hepatic steatosis. The mitochondrial membrane protein UCP2 is considered to be one of the key proteins in reducing fatty liver that acts by targeting liver mitochondria to improve cellular oxidative stress. Improving insulin resistance may also be one of the important mechanisms by which BBR alleviates MAFLD. This mechanism is mainly related to the glucose transporter and insulin resistance-related protein IRS. However, BBR is absorbed and first eliminated in the small intestine. More than 99% of BBR does not enter the bloodstream. It is speculated that BBR mainly plays a biological role in alleviating hepatic steatosis by acting through the intestinal tract, but the specific mechanism and target of BBR remain unclear. Some studies have indicated that the effect of BBR on the improvement of the intestinal microenvironment and the inhibition of intestinal lipid uptake may be the key mechanism. BBR can alleviate MAFLD by improving intestinal dysregulation, reducing blood lipids and inflammatory cytokines, and restoring bile acids. In addition, BBR, absorbed by intestinal epithelial cells, can regulate intestinal lipid uptake. Soat2 may be an important regulatory target of BBR in the intestine. By regulating Soat2, BBR can inhibit the expression of proteins related to lipid uptake in the intestinal epithelium and inhibit the uptake of free fatty acids and cholesterol in the intestinal tract. Recent studies have found that Soat2 is a target gene of hepatic X receptor (LXRα) transcriptional regulation. If the LXR inverse activator acts only in the gut, it can effectively inhibit Soat2 expression, reduce cholesterol reabsorption, and lower plasma LDL levels. Therefore, the LXR-SOAT2 regulatory mechanism may also be involved in the regulation of fatty acid uptake in the gut by BBR. In this review, we briefly summarize the mechanism by which BBR acts in the direct regulation of liver lipid metabolism, including activating the AMPK pathway and alleviating liver inflammation and oxidative stress. A potential biological target of BBR in the intestinal tract that could ameliorate MAFLD by improving the intestinal microenvironment and inhibiting intestinal lipid uptake was also reviewed.

Overexpression of Pregnancy Zone Protein in Fat Antagonizes Diet-Induced Obesity Under an Intermittent Fasting Regime.

The intermittent fasting regimen (IFR) has been certified as an effective strategy for improving metabolism. But the underlying mechanism is still obscure. Beige induction in white adipose tissue (WAT) by IFR may account for this. It has been demonstrated that the erupting of pregnancy zone protein (PZP) from the liver coincides with membrane translocation of grp78 in brown adipocytes during IFR to activate brown adipose tissue (BAT), which may partly explain the metabolic benefits of IFR. Liver-derived PZP appears to be responsible for all metabolic regulatory functions; the effect of boosting energy expenditure disappeared in liver-deficient mice. To verify whether any liver-specific modification was essential for functional PZP, we used the PZP adipose tissue-specific overexpression mice model (PZP TG). We found that the metabolic disorders induced by high-fat diet were improved in PZP TG mice under IFR. Additionally, in addition to the activation of BAT, UCP1 protein and angiogenesis were increased in WAT, as well as the expression of genes associated with glucose utilization. These results demonstrate that PZP fat-specific TG increased the energy conversion of WAT, indicating that WAT may be another direct target for PZP during IFR.

Obesity in male volcano mice Neotomodon alstoni affects the daily rhythm of metabolism and thermoregulation.

The mouse N. alstoni spontaneously develops the condition of obesity in captivity when fed regular chow. We aim to study the differences in metabolic performance and thermoregulation between adult lean and obese male mice. The experimental approach included indirect calorimetry using metabolic cages for VO2 intake and VCO2 production. In contrast, the body temperature was measured and analyzed using intraperitoneal data loggers. It was correlated with the relative presence of UCP1 protein and its gene expression from interscapular adipose tissue (iBAT). We also explored in this tissue the relative presence of Tyrosine Hydroxylase (TH) protein, the rate-limiting enzyme for catecholamine biosynthesis present in iBAT. Results indicate that obese mice show a daily rhythm persists in estimated parameters but with differences in amplitude and profile. Obese mice presented lower body temperature, and a low caloric expenditure, together with lower VO2 intake and VCO2 than lean mice. Also, obese mice present a reduced thermoregulatory response after a cold pulse. Results are correlated with a low relative presence of TH and UCP1 protein. However, qPCR analysis of Ucp1 presents an increase in gene expression in iBAT. Histology showed a reduced amount of brown adipocytes in BAT. The aforementioned indicates that the daily rhythm in aerobic metabolism, thermoregulation, and body temperature control have reduced amplitude in obese mice Neotomodon alstoni.

Positive Effects of a Mediterranean Diet Supplemented with Almonds on Female Adipose Tissue Biology in Severe Obesity.

It has been suggested that weight-loss-independent Mediterranean diet benefits on cardiometabolic health and diabetes prevention may be mediated, at least in part, through the modulation of white adipose tissue (WAT) biology. This study aimed to evaluate the short-term effects of a dietary intervention based on the Mediterranean diet supplemented with almonds (MDSA) on the main features of obesity-associated WAT dysfunction. A total of 38 women with obesity were randomly assigned to a 3-month intervention with MDSA versus continuation of their usual dietary pattern. Subcutaneous (SAT) and visceral adipose tissue (VAT) biopsies were obtained before and after the dietary intervention, and at the end of the study period, respectively. MDSA favored the abundance of small adipocytes in WAT. In SAT, the expression of angiogenesis genes increased after MDSA intervention. In VAT, the expression of genes implicated in adipogenesis, angiogenesis, autophagy and fatty acid usage was upregulated. In addition, a higher immunofluorescence staining for PPARG, CD31+ cells and M2-like macrophages and increased ADRB1 and UCP2 protein contents were found compared to controls. Changes in WAT correlated with a significant reduction in circulating inflammatory markers and LDL-cholesterol levels. These results support a protective effect of a Mediterranean diet supplemented with almonds on obesity-related WAT dysfunction.

Metformin and vitamin D modulate adipose-derived stem cell differentiation towards the beige phenotype

ABSTRACT Adipose-derived stem cells (ADSCs) represent an ideal stem cell population for regenerative medicine. ADSC adipogenic differentiation is controlled by the activation of a specific transcriptional program, including epigenetic factors and key adipogenic genes. Under certain conditioned media, ADSCs can differentiate into several phenotypes. We previously demonstrated that bioactive molecules could counteract lipid accumulation and regulate adipogenesis, acting on inflammation and vitamin D metabolism. In the present paper, we aimed at evaluating the effect of metformin and vitamin D in targeting ADSC differentiation towards an intermediate phenotype, as beige adipocytes. We exposed ADSCs to different conditioned media and then we evaluated the levels of expression of main markers of adipogenesis, aP2, LPL and ACOT2. We also analysed the gene and protein expression of thermogenic UCP1 protein, and the expression of PARP1 and the beige specific marker TMEM26. Our results showed a novel effect of metformin and vitamin D not only in inhibiting adipogenesis, but also in inducing a specific ‘brown-like’ phenotype. These findings pave the way for their possible application in the control of de novo lipogenesis useful for the prevention of obesity and its related metabolic disorders.

Improved oral nutraceutical-based intervention for themanagement of obesity: pterostilbene-loaded chitosan nanoparticles.

Aim: To formulate and assess the oral anti-obesity effect of polymeric-based pterostilbene (PS)-loaded nanoparticles. Methods: Pterostilbene-hydroxypropyl β-cyclodextrin inclusion complex loaded in chitosan nanoparticles (PS/HPβCD-NPs) were prepared and characterized in vitro. Cytotoxicity, pharmacokinetics and anti-obesity effects were assessed on Caco-2 cell line and high-fat-diet-induced obesity rat model, respectively. In vivo assessment included histological examination, protein and gene expression of obesity biomarkers in adipose tissues. Results: Safe PS/HPβCD-NPs were successfully prepared with improved bioavailability compared with free PS. PS/HPβCD-NPs showed an improved anti-obesity effect, as supported by histological examination, lipid profile, UCP1 gene expression and protein expression of SIRT1, COX2, IL-6 and leptin. Conclusion: Orally administered PS nanoparticles represent a new and promising anti-obesity strategy owing to the sustainable weight loss and minimal side effects; this may be of great socio-economic impact.

Mitochondrial Respiration-Dependent ANT2-UCP2 Interaction.

Adenine nucleotide translocases (ANTs) and uncoupling proteins (UCPs) are known to facilitate proton leak across the inner mitochondrial membrane. However, it remains to be unravelled whether UCP2/3 contribute to significant amount of proton leak in vivo. Reports are indicative of UCP2 dependent proton-coupled efflux of C4 metabolites from the mitochondrial matrix. Previous studies have suggested that UCP2/3 knockdown (KD) contributes to increased ANT-dependent proton leak. Here we investigated the hypothesis that interaction exists between the UCP2 and ANT2 proteins, and that such interaction is regulated by the cellular metabolic demand. Protein-protein interaction was evaluated using reciprocal co-immunoprecipitation and in situ proximity ligation assay. KD of ANT2 and UCP2 was performed by siRNA in human embryonic kidney cells 293A (HEK293A) cells. Mitochondrial and cellular respiration was measured by high-resolution respirometry. ANT2-UCP2 interaction was demonstrated, and this was dependent on cellular metabolism. Inhibition of ATP synthase promoted ANT2-UCP2 interaction whereas high cellular respiration, induced by adding the mitochondrial uncoupler FCCP, prevented interaction. UCP2 KD contributed to increased carboxyatractyloside (CATR) sensitive proton leak, whereas ANT2 and UCP2 double KD reduced CATR sensitive proton leak, compared to UCP2 KD. Furthermore, proton leak was reduced in double KD compared to UCP2 KD. In conclusion, our results show that there is an interaction between ANT2-UCP2, which appears to be dynamically regulated by mitochondrial respiratory activity. This may have implications in the regulation of mitochondrial efficiency or cellular substrate utilization as increased activity of UCP2 may promote a switch from glucose to fatty acid metabolism.

The Effect of Lipolysis Inhibitor Acipimox on Brown Adipose Tissue Bioenergetics and Uncoupling Protein Abundance in Severely Burned Rats

IntroductionUncoupling protein 1 (UCP1) activation in brown adipose tissue (BAT) contributes to the hypermetabolic stress response to burn trauma. Strategies that target BAT UCP1 could be beneficial in controlling burn‐induced hypermetabolism. Acipimox, an inhibitor of adipose tissue lipolysis, has been shown to be effective at blunting burn‐induced lipolysis and expression of UCP1 protein in rodent white adipose tissue. The impact of acipimox on BAT bioenergetics and uncoupling protein abundance is currently unknown. We hypothesized that acipimox would blunt burn‐induced UCP‐1 dependent respiration and UCP‐1 protein levels in BAT.MethodsSixty‐four male Sprague‐Dawley rats received a 60% TBSA scald burn (n=32) or sham procedure (n=32) and were subsequently randomized to receive either acipimox (n=16/group; 50 mg/kg/day i.p.) or vehicle (n=16/group) daily for 7d. BAT was harvested from the interscapular fat pad on day 7 after burn and mitochondrial respiratory function assessed by high‐resolution respirometry. GDP‐sensitive respiration was assayed as a direct measure of UCP1 function. UCP1 and adenine nucleotide translocator (ANT2) protein levels were determined by western blot.ResultsUCP1‐dependent and UCP1‐independent uncoupled respiration in BAT was reduced at 7d after severe burn, independent of treatment (injury effect, P&lt;0.01). Post‐burn, UCP1‐dependent respiration accounted for 65% of total uncoupled respiration compared to 59% in sham rats (injury effect, P&lt;0.05), independent of treatment. Acipimox appeared to exert a lowering effect on UCP1‐dependent respiration (treatment effect, P=0.07) but not on UCP1‐independent respiration. Neither burn nor treatment with acipimox had a significant effect on UCP1 protein levels. Protein levels of ANT2, a carrier protein involved in fatty acid‐induced uncoupling, were greater in response to acipimox (treatment effect, P&lt;0.05).ConclusionBAT UCP1 function than UCP1 protein content is greater in severely burned rats. Acipimox appears to reduce UCP1‐dependent respiration, independent of UCP1 protein levels. The effect of acipimox on BAT ANT2 protein content may partly explain the absence of an effect on UCP1‐independent respiration, but this warrants further investigation.The protocol was approved by the University of Texas Medical Branch IACUC.

Curbing High‐Fat Induced Perturbations in Aortic Perivascular Adipose Tissue in Adolescent Male Sprague‐Dawley Rats: Soil as Therapy?

Directly attached to the outer wall of blood vessels, perivascular adipose tissue (PVAT) is a unique variant of fat that is an important paracrine modulator of vascular physiology. Due to the proximity and endocrine‐like characteristics of this tissue, PVAT can contribute to the regulation vascular contractility and endothelial function. PVAT can also assume several properties of brown adipose tissue, including increased vascularization, small lipid droplet formation, mitochondrial density, and production of cardiometabolic signaling intermediates. Importantly, these properties promote the metabolic activity of this tissue which appear to be associated with improved vascular health. However, such properties may be diminished by chronic deleterious stimuli such as a high‐fat diet (HFD) and disease conditions like metabolic syndrome. Under such pressures, PVAT may serve a more insidious role in vascular dysfunction and promote the development of cardiovascular disease. Chronic diet‐induced changes in the vasculature and associated tissues like PVAT may be occurring early in the life cycle, promoting degeneration and disease‐associated remodeling. Currently, examination of these tissues early in life remain relatively unexplored and may offer important insight into the identification of prevention strategies and therapeutic targets. Previously, our lab identified increased expression of genes in the aorta of HFD fed adolescent Sprague‐Dawley rats, highlighting potential pathways and signaling intermediates that may impact the development of early vascular dysfunction. Moreover, we have demonstrated that an organic mineral complex (OMC) derived from plant and soil fractions prevented symptoms of metabolic syndrome in these animals. OMC is a complex of minerals, trace elements, organic acids (particularly fulvic acid), nitrates, and various microbial degradation products from plant and animal origins. The objective of the current study is to investigate the effects of a HFD and OMC on the expression of key proteins in aortic PVAT that play a role in adipose beiging, metabolism, and mitochondrial biogenesis, and are thus expected to provide critical insight into early mitigation of vascular disease progression. Six‐week‐old male Sprague‐Dawley rats (n = 36) were divided into two dietary groups: Chow or HFD fed for 10 weeks. Animals were further divided (n = 6/group) and administered 0, 0.6, or 3.0 mg/mL OMC in their drinking water. After the 10‐week intervention PVAT surrounding the aorta was extracted from the animals and Western blot analyses were performed using antibodies for the proteins UCP1, SDHA, PI3K, GLUT4, and b‐actin (as a loading control). Overall, we hypothesize that OMC supplementation will minimize decreases in these key proteins involved in health associated PVAT metabolism and function.

Skinny people serum factors promote the differentiation of multipotent stem cells into brown adipose tissue.

The original study by Alessio et al reported that skinny people (SP) serum can promote the formation of brown adipocytes, but not the differentiation of white adipocytes. This finding may explain why SP do not often become obese, despite consuming more calories than the body needs. More importantly, they demonstrated that circulating factors in SP serum can promote the expression of UCP-1 protein, thereby reducing fat accumulation. In this study, only male serum samples were evaluated to avoid the interference of sex hormones in experiments, but adult males also synthesize estrogen, which is produced by the cells of the testes. At the same time, adult females secrete androgens, and females synthesize androgens that are mainly produced by the adrenal cortex. We believe that the approach of excluding sex hormone interference by sex selection alone may be flawed, so we comment on the article and debate the statistical analysis of the article.

RMR-Related DNAJC6 Expression Suppresses Adipogenesis in 3T3-L1 Cells.

Obesity causes various complications such as type 2 diabetes, hypertension, fatty liver, cardiovascular diseases, and cancer. In a pilot GWAS study, we screened the DNAJC6 gene which is significantly related to the resting metabolic rate (RMR) in childhood obesity. With DNAJC6-overexpressed 3T3-L1 cells (TgHsp), we investigated the new obesity mechanism caused by an energy imbalance. After differentiation, lipid droplets (Oil red O staining) were not formed in TgHsp cells compared to the control. TgHsp preadipocyte fibroblast morphology was also not clearly observed in the cell morphology assay (DAPI/BODIPY). In TgHsp cells, the expression of PPARγ, C/EBPα, and aP2 (adipogenesis-related biomarkers) decreased 3-, 39-, and 200-fold, respectively. The expression of the adipokines leptin and adiponectin from adipose tissues also decreased 2.4- and 840-fold, respectively. In addition, the levels of pHSL(Ser563) and free glycerol, which are involved in lipolysis, were significantly lower in TgHsp cells than in the control. The reduction in insulin receptor expression in TgHsp cells suppressed insulin signaling systems such as AKT phosphorylation, and GLUT4 expression. Degradation of IRS-1 in 3T3-L1 adipocytes was caused by chronic exposure to insulin, but not TgHsp. Mitochondrial functions such as oxygen consumption and ATP production, as well as proton leak and UCP1 protein expression, decreased in TgHsp cells compared to the control. Moreover, autophagy was observed by increasing autophagosomal proteins, LC3, on Day 8 of differentiation in TgHsp cells. Through our first report on the DNAJC6 gene related to RMR, we found a new mechanism related to energy metabolism in obesity. DNAJC6 expression positively suppressed adipogenesis, leading to the subsequent resistance of lipolysis, adipokine expression, insulin signaling, and mitochondrial functions.

Evaluation of Browning Markers in Subcutaneous Adipose Tissue of Newly Diagnosed Gastrointestinal Cancer Patients with and without Cachexia.

Simple SummaryCachexia occurs frequently in cancer patients with deep metabolic derangements. The browning of adipose tissue promotes thermogenesis and energy expenditure and, in cancer, has been considered a major determinant of adipose tissue atrophy. We evaluated the molecular phenotype of this phenomenon in the subcutaneous adipose tissue (SAT) of newly diagnosed gastrointestinal cancer patients compared to controls. We observed that the modulation of different markers of the browning of SAT in gastrointestinal cancer and, in particular, pancreatic cancer showed significant changes in UCP1 and PGC1α; PGC1α was highly expressed in cachectic patients. Our study highlights the relevance of browning in patients with cancer, in particular in those with pancreatic cancer. Understanding the browning phenomenon may allow us to counteract these metabolic alterations before the development of severe cachexia, which is characterized by deep adipose and muscle depletion, negatively affecting survival and quality of life.We assessed the molecular phenotype of the browning of white adipose tissue in newly diagnosed cancer patients and controls undergoing surgery for gastrointestinal tumors and for non-malignant diseases, respectively. We collected subcutaneous adipose tissue (SAT) samples and using RT-PCR, we analyzed the expression of markers of browning and using Western blot the protein levels of UCP1 and PGC1α. The Ucp1 mRNA levels were lower in cancer patients vs. controls (p = 0.01), whereas Cidea and Tmem26 mRNA levels were higher in cancer patients. We found higher PGC1α protein levels in patients vs. controls, while no differences were seen for UCP1. The Ucp1 expression was lower in cachectic and non-cachectic patients vs. controls, whereas Cidea expression was higher in cachectic and non-cachectic patients vs. controls. Pgc1α mRNA levels were higher in cachectic vs. non-cachectic patients (p = 0.03) vs. controls (p = 0.016). According to type of tumors, we did not observe differences in Cidea expression, whereas Pgc1α was higher in pancreatic cancer vs. colorectal and vs. controls. We observed the lower expression of Ucp1 in pancreatic and colorectal cancer vs. controls. We documented higher UCP1 protein levels in pancreatic cancer patients vs. colorectal (p = 0.002) and vs. controls (p = 0.031). PGC1α protein levels were higher in pancreatic cancer patients vs. controls. Different markers of the browning of SAT are modulated, and pancreatic cancer showed changes in UCP1 and PGC1α; PGC1α was highly expressed in cachectic patients, with clinical implications that should be further clarified.

Effects of meteorin-like hormone on endocrine function of hypothalamo-hypophysial system and peripheral uncoupling proteins in rats.

Meteorin-like hormone (Metrnl) is a peptide secreted from the adipose tissue and modulates the whole-body energy metabolism. Metrnl release into the circulation is influenced by obesity, cold exposure, and exercise. Thyroid hormones also exert many of their effects on metabolism through uncoupling proteins (UCPs). This study aimed to determine effect of Metrnl on hypothalamo-hypophysier-thyroid axis and energy metabolism and reveal the possible involvement of UCPs in this process. Fourty male Sprague-Dawley rats were divided into 4 groups with 10 animals in each group: control, sham, 10 and 100nM Metrnl. Hypothalamus, muscle, white adipose tissue (WAT) and brown adipose tissue (BAT) samples were collected to detect thyrotropin-releasing hormone (TRH), and UCP1 and UCP3 protein levels by western blot analysis. Serum thyroid-stimulating hormone (TSH), triiodothyronine (T3) and thyroxine (T4) hormone levels were determined by enzyme-linked immunosorbent assay. Central infusion of Metrnl caused significant increase in serum TSH, T3 and T4 levels compared to control (p < 0.05). After Metrnl treatment, there were significant increases in TRH in hypothalamus tissue, UCP1 in WAT and BAT; and UCP3 protein in the muscle tissue (p < 0.05). The findings that Metrnl induced increases in the peripheral UCPs and hypothalamus-pituitary-thyroid axis hormones implicate a role for this hormone in body energy homeostasis through UCP-mediated mechanisms.

RNA-Seq reveals miRNA role in thermogenic regulation in brown adipose tissues of goats

BackgroundMicroRNAs (miRNAs) are a family of short non-coding RNA molecules and play important roles in various biological processes. However, knowledge of the expression profiles and function of miRNAs on the regulation of brown adipose tissue (BAT) thermogenesis remains largely unknown.ResultsIn this study, we found that brown adipose tissue (BAT) existed within the perirenal fat at 1 day after birth (D1) and transferred into white adipose tissue (WAT) at 30 days after birth (D30) by UCP1 protein expression and immunohistochemistry analysis. After that, we performed RNA sequencing on six libraries of goat BAT and WAT. A total of 238 known miRNAs and 1834 goat novel miRNAs were identified. Moreover, 395 differentially expressed miRNAs including 167 up-regulated and 228 down-regulated miRNAs were obtained in BAT. For the known BAT enriched miRNA, 30 miRNAs were enriched in goat BAT but not in mouse BAT. In addition, miR-433 was enriched in goat BAT but not in mouse BAT. Gain- and loss-of-function experiments reveal that miR-433 reduced the lipid accumulation of brown adipocytes and decreased the expression of BAT marker and mitochondrial related genes. However, miR-433 had no effect on lipid accumulation and thermogenesis in white adipocytes. In addition, miR-433 inhibited the expression of MAPK8 by targeting to the 3’UTR of MAPK8 gene. These data demonstrate that miR-433 acts as a negative regulator in controlling brown adipocytes differentiation and thermogenesis.ConclusionThe present study provides a detailed miRNAs expression landscape in BAT and WAT. Furthermore, we found that miR-433, which was highly expressed on BAT had a negative regulatory function on the thermogenesis and adipogenesis in goat brown adipocytes. This study provides evidence for understanding the role of miRNAs in regulating BAT thermogenesis and energy expenditure in goats.

Honokiol Ameliorates Post-Myocardial Infarction Heart Failure Through Ucp3-Mediated Reactive Oxygen Species Inhibition.

Post-myocardial infarction heart failure (post-MI HF) is one of the leading global causes of death, and current prevention and treatment methods still cannot avoid the increasing incidence. Honokiol (HK) has previously been reported to improve myocardial ischemia/reperfusion injury and reverse myocardial hypertrophy by activating Sirt1 and Sirt3. We suspect that HK may also have a therapeutic effect on post-MI HF. In this study, we aimed to investigate the efficacy and mechanism of HK in the treatment of post-MI HF. We found that HK inhibited myocardial reactive oxygen species (ROS) production, reduced myocardial fibrosis, and improved cardiac function in mice after MI. HK also reduced the abnormality of mitochondrial membrane potential (MMP) and apoptosis of cardiomyocytes caused by peroxide in neonatal cardiomyocytes. RNAseq results revealed that HK restored the transcriptome changes to a certain extent and significantly enhanced the expression of mitochondrial inner membrane uncoupling protein isoform 3 (Ucp3), a protein that inhibits the production of mitochondrial ROS, protects cardiomyocytes, and relieves heart failure after myocardial infarction (MI). In cardiomyocytes with impaired Ucp3 expression, HK cannot protect against the damage caused by peroxide. More importantly, in Ucp3 knockout mice, HK did not change the increase in the ROS level and cardiac function damage after MI. Taken together, our results suggest that HK can increase the expression of the cardioprotective protein Ucp3 and maintain MMP, thereby inhibiting the production of ROS after MI and ameliorating heart failure.

Whole Body Ip6k1 Deletion Protects Mice from Age-Induced Weight Gain, Insulin Resistance and Metabolic Dysfunction.

(1) Background: We previously demonstrated that disruption of IP6K1 improves metabolism, protecting mice from high-fat diet-induced obesity, insulin resistance, and non-alcoholic fatty liver disease and steatohepatitis. Age-induced metabolic dysfunction is a major risk factor for metabolic diseases. The involvement of IP6K1 in this process is unknown. (2) Methods: Here, we compared body and fat mass, insulin sensitivity, energy expenditure and serum-, adipose tissue- and liver-metabolic parameters of chow-fed, aged, wild type (aWT) and whole body Ip6k1 knockout (aKO) mice. (3) Results: IP6K1 was upregulated in the adipose tissue and liver of aWT mice compared to young WT mice. Moreover, Ip6k1 deletion blocked age-induced increase in body- and fat-weight and insulin resistance in mice. aKO mice oxidized carbohydrates more efficiently. The knockouts displayed reduced levels of serum insulin, triglycerides, and non-esterified fatty acids. Ip6k1 deletion partly protected age-induced decline of the thermogenic uncoupling protein UCP1 in inguinal white adipose tissue. Targets inhibited by IP6K1 activity such as the insulin sensitivity- and energy expenditure-inducing protein kinases, protein kinase B (PKB/Akt) and AMP-activated protein kinase (AMPK), were activated in the adipose tissue and liver of aKO mice. (4) Conclusions: Ip6k1 deletion maintains healthy metabolism in aging and thus, targeting this kinase may delay the development of age-induced metabolic dysfunction.

Survivin is essential for thermogenic program and metabolic homeostasis in mice

ObjectiveSurvivin is a member of the inhibitor of apoptosis family. Our previous study showed that survivin expression could be strongly induced by long-term, high-fat diet (HFD) exposure in vivo. It could also be induced by insulin through the PI3K/mTOR signaling pathway in vitro. Therefore, we hypothesized that under certain conditions, survivin expression might be required for adipocyte function. In the current study, we aim to further investigate the regulation of survivin expression in mature adipocytes upon various nutritional stimuli and the role of survivin using adipocyte-specific survivin knockout (SKO) mice. MethodsSKO mice were obtained by crossing survivinflox/flox mice with Adiponectin-Cre+/- mice. The overall metabolic phenotype was observed under chow diet (CD) and HFD feeding conditions. The thermogenic program of mice was detected upon cold exposure. The inguinal white adipose tissue (iWAT) and brown adipose tissue (BAT) stromal vascular fraction cells were isolated and differentiated into mature adipocytes, and the effects of survivin deletion on mature adipocyte function were detected in vitro. ResultsSurvivin expression in adipose tissue and adipocytes was regulated by short-term nutritional stress both in vivo and in vitro. The postnatal development of BAT was impaired in SKO mice, which resulted in drastically reduced BAT mass and decreased expression of the thermogenic protein Ucp1 in 24-week-old mice fed with CD. After HFD feeding, the iWAT and BAT mass of SKO mice were significantly decreased, causing ectopic lipid accumulation in the liver, which was associated with insulin resistance and glucose intolerance. Upon cold exposure, the expression of thermogenic genes and proteins was markedly reduced in BAT and iWAT of SKO mice, accompanied by abnormal mitochondrial structure and induced autophagy. Consistently, thermogenic program and mitochondrial oxidative phosphorylation were reduced in survivin-depleted brown and beige adipocytes in vitro. ConclusionsOur findings showed that survivin could be regulated by nutritional stress in adipocytes and revealed a new role of survivin in maintaining normal BAT mass and positively regulating the thermogenic program and mitochondrial oxidative phosphorylation.

Whole-body and adipose tissue metabolic phenotype in cancer patients.

BackgroundAltered adipose tissue (AT) metabolism in cancer‐associated weight loss via inflammation, lipolysis, and white adipose tissue (WAT) browning is primarily implicated from rodent models; their contribution to AT wasting in cancer patients is unclear.MethodsEnergy expenditure (EE), plasma, and abdominal subcutaneous WAT were obtained from men (aged 65 ± 8 years) with cancer, with (CWL, n = 27) or without (CWS, n = 47) weight loss, and weight‐stable non‐cancer patients (CON, n = 26). Clinical images were assessed for adipose and muscle area while plasma and WAT were assessed for inflammatory, lipolytic, and browning markers.ResultsCWL displayed smaller subcutaneous AT (SAT; P = 0.05) and visceral AT (VAT; P = 0.034) than CWS, and displayed higher circulating interleukin (IL)‐6 (P = 0.01) and WAT transcript levels of IL‐6 (P = 0.029), IL‐1β (P = 0.042), adipose triglyceride lipase (P = 0.026), and browning markers (Dio2, P = 0.03; PGC‐1a, P = 0.016) than CWS and CON. There was no difference across groups in absolute REE (P = 0.061), %predicted REE (P = 0.18), circulating free fatty acids (FFA, P = 0.13) or parathyroid hormone‐related peptide (PTHrP; P = 0.88), or WAT protein expression of inflammation (IL‐6, P = 0.51; IL‐1β, P = 0.29; monocyte chemoattractant protein‐1, P = 0.23) or WAT protein or gene expression of browning (uncoupling protein‐1, UCP‐1; P = 0.13, UCP‐1, P = 0.14). In patients with cancer, FFA was moderately correlated with WAT hormone‐sensitive lipase transcript (r = 0.38, P = 0.018, n = 39); circulating cytokines were not correlated with expression of WAT inflammatory markers and circulating PTHrP was not correlated with expression of WAT browning markers. In multivariate regression using cancer patients only, body mass index (BMI) directly predicted SAT (N = 25, R 2 = 0.72, P < 0.001), VAT (N = 28, R 2 = 0.64, P < 0.001), and absolute REE (N = 22, R 2 = 0.43, P = 0.001), while BMI and WAT UCP‐1 protein were indirectly associated with %predicted REE (N = 22, R 2 = 0.45, P = 0.02), and FFA was indirectly associated with RQ (N = 22, R 2 = 0.52, P < 0.001).ConclusionsCancer‐related weight loss was associated with elevated circulating IL‐6 and elevations in some WAT inflammatory, lipolytic and browning marker transcripts. BMI, not weight loss, was associated with increased energy expenditure. The contribution of inflammation and lipolysis, and lack thereof for WAT browning, will need to be clarified in other tumour types to increase generalizability. Future studies should consider variability in fat mass when exploring the relationship between cancer and adipose metabolism and should observe the trajectory of lipolysis and energy expenditure over time to establish the clinical significance of these associations and to inform more mechanistic interpretation of causation.