UCP2 Gene Expression Research Articles

Sleep deprivation stimulates adaptive thermogenesis by activating AMPK pathway in mice.

Sleep deprivation (SD) can affect the adaptive thermogenesis in laboratory rodents, but the molecular mechanism and the crosstalk with other organs remain largely unknown. In order to investigate the effects and mechanisms of SD on thermoregulation and energy metabolism, here we measured the changes of body weight, body fat mass, body temperature, resting metabolic rate (RMR), and thermogenic gene expression in brown adipose tissue (BAT), white adipose tissue (WAT), skeleton muscle and liver in C57BL/6J mice during 7-day SD with rotating rod sleep deprivation device. Results showed that compared with the control group, the body weight and body fat mass of SD mice were decreased and RMR of SD mice increased. The gene expression of Ampk, Pgc1α and Ucp1 which related to thermogenesis in BAT and WAT were significantly increased, and the expression of Ampk, Serca1, Serca2 and Ucp3 which related to thermogenesis in skeletal muscle were significantly increased in SD mice. Taken together, these data demonstrated that 7-day SD enhanced the adaptive thermogenesis in mice by activating AMPK, including the upregulation of the AMPK - PGC1α - UCP1 pathway in BAT, and the AMPK - UCP3 and SLN - SERCA pathway in skeleton muscle. Our data provide the molecular evidence for SD-stimulated adaptive thermogenesis and energy metabolism in small mammals.

Hypoxia-inducible factor-1α-deficient adipose-tissue macrophages produce the heat to mediate lipolysis of white adipose tissue through uncoupling protein-1

BackgroundUncoupling protein 1 (UCP1) is a proton uncoupler located across the mitochondrial membrane generally involved in thermogenesis of brown adipose tissues. Although UCP1 is known to be strongly expressed in brown adipocytes, recent evidence suggest that white adipocytes can also express UCP1 under certain circumstances such as cold- or β-adrenergic receptor-stimulation, allowing them to acquire brown adipocyte-like features thereby becoming 'beige’ adipocytes.ResultsIn this study, we report that UCP1 can be expressed in adipose-tissue macrophages (ATM) lacking functional hypoxia-inducible factor-1 (HIF-1) and this does not require cold- nor β-adrenergic receptor activation. By using myeloid-specific Hif-1α knockout (KO) mice, we observed that these mice were protected from diet-induced obesity and exhibited an improved thermogenic tolerance upon cold challenge. ATM isolated from white adipose tissues (WAT) of these mice fed with high fat diet exhibited significantly higher M2-polarization, decreased glycolysis, increased mitochondrial functions and acetyl-CoA levels, along with increased expression of Ucp1, peroxisome proliferator activated receptor-gamma co-activator-1a, and others involved in histone acetylation. Consistent with the increased Ucp1 gene expression, these ATM produced a significant amount of heat mediating lipolysis of co-cultured adipocytes liberating free fatty acid. Treating ATM with acetate, a substrate for acetyl-CoA synthesis was able to boost the heat production in wild-type or Hif-1α-deficient but not UCP1-deficient macrophages, indicating that UCP1 was necessary for the heat production in macrophages. Lastly, we observed a significant inverse correlation between the number of UCP1-expressing ATM in WAT and the body mass index of human individuals.ConclusionsUCP1-expressing ATM produce the heat to mediate lipolysis of adipocytes, indicating that this can be a novel strategy to treat and prevent diet-induced obesity.

Role of the sympathetic nervous system in cancer-associated cachexia and tumor progression in tumor-bearing BALB/c mice

BackgroundAdipose and muscle tissue wasting outlines the cachectic process during tumor progression. The sympathetic nervous system (SNS) is known to promote tumor progression and research suggests that it might also contribute to cancer-associated cachexia (CAC) energetic expenditure through fat wasting.MethodsWe sympathectomized L5178Y-R tumor-bearing male BALB/c mice by intraperitoneally administering 6-hydroxydopamine to evaluate morphometric, inflammatory, and molecular indicators of CAC and tumor progression.ResultsTumor burden was associated with cachexia indicators, including a 10.5% body mass index (BMI) decrease, 40.19% interscapular, 54% inguinal, and 37.17% visceral adipose tissue loss, a 12% food intake decrease, and significant (p = 0.038 and p = 0.0037) increases in the plasmatic inflammatory cytokines IL-6 and IFN-γ respectively. Sympathectomy of tumor-bearing mice was associated with attenuated BMI and visceral adipose tissue loss, decreased interscapular Ucp-1 gene expression to basal levels, and 2.6-fold reduction in Mmp-9 relative gene expression, as compared with the unsympathectomized mice control group.ConclusionThe SNS contributes to CAC-associated morphometric and adipose tissue alterations and promotes tumor progression in a murine model.

A Pilot Study of Gene Expression Modulation from Antioxidant System of Killifish Austrolebias charrua After Exposure to Roundup Transorb®.

Roundup Transorb® (RDT) is the most popular glyphosate-based herbicide (GHB) used in agriculture, and its impact extends to non-target organisms. The annual killifish Austrolebias charrua is an endangered species endemic to southern South America and inhabits temporary ponds. This study evaluates the effects of RDT concentrations (0.065 and 5mg/L GAE) on A. charrua exposed for 96h. Gene expression of cat, sod2, gstα, gclc, and ucp1 was evaluated on the liver and gills. Highlighting that even at low concentrations permitted by Brazilian legislation, the RDT can have adverse effects on A. charrua.

Polyelectrolyte nanofilms on cell surface can induce brown adipogenic differentiation of DFATs

Obesity and its related health issues significantly burden public health systems. Brown adipose tissue holds promise for addressing metabolic disorders and balancing the body's energy, making it a key research focus. Stimulating brown adipogenesis from stem cells could advance regenerative medicine and healthcare. In our previous research, we discovered that poly-l-lysine (PLL) significantly stimulates brown adipogenesis in three-dimensional differentiation of dedifferentiated fat cells (DFATs) within fibrin gels. In this study, we evaluated polyelectrolyte (PE) nanofilms made of PLL and dextran sulfate, applied directly to DFAT surfaces to improve brown adipogenic differentiation through an innovative approach. This approach involved coating the DFAT surfaces with PE nanofilms, forming a multilayer structure that not only provided a supportive matrix but also facilitated the adsorption of essential molecules like T3 and insulin for brown adipogenesis. DFATs coated with three PE layers and encapsulated in fibrin gel showed a significant increase in the adipogenic marker UCP1 gene expression and content. This PLL-based PE nanofilm coating on DFAT surfaces can be a novel and crucial technology for promoting brown adipogenesis in regenerative medicine and healthcare.

Cationic polymer effect on brown adipogenic induction of dedifferentiated fat cells

Obesity and its associated comorbidities place a substantial burden on public health. Given the considerable potential of brown adipose tissue in addressing metabolic disorders that contribute to dysregulation of the body's energy balance, this area is an intriguing avenue for research. This study aimed to assess the impact of various polymers, including collagen type I, fibronectin, laminin, gelatin, gellan gum, and poly-l-lysine (PLL), on the in vitro brown adipogenic differentiation of dedifferentiated fat cells within a fibrin gel matrix. The findings, obtained through RT-qPCR, immunofluorescent imaging, ELISA assay, and mitochondria assessment, revealed that PLL exhibited a significant browning-inducing effect. Compared to fibrin-only brown-like drops after two weeks of incubation in brown adipogenic medium, PLL showed 6 (±3) times higher UCP1 gene expression, 5 (±2) times higher UCP1 concentration by ELISA assay, and 2 (±1) times higher mitochondrial content. This effect can be attributed to PLL's electrostatic properties, which potentially facilitate the cellular uptake of crucial brown adipogenic inducers such as the thyroid hormone, triiodothyronine (T3), and insulin from the induction medium.

Metformin Lowers Plasma Triacylglycerol Levels in Mice with Impaired Carnitine Biosynthesis and Fatty Liver

The antidiabetic drug metformin has a wide range of metabolic effects and may also reduce the risk of obesity-related diseases. The aim of the current study was to investigate if metformin could counteract meldonium-induced fatty liver. Four groups of male C57BL/6J mice were fed a low-fat control diet, or low-fat diets supplemented with metformin, meldonium, or metformin and meldonium for three weeks. Meldonium treatment led to 5.2-fold higher hepatic triacylglycerol (TAG) levels compared to control, and metformin lowered the meldonium-induced lipid accumulation insignificantly by 21%. Mice treated with metformin and meldonium demonstrated significantly lower weight gain, visceral adipose tissue weight and plasma levels of TAG compared to meldonium alone. The hepatic mRNA level of carnitine palmitoyl transferase 1 was increased 2-fold with combined meldonium and metformin treatment compared to meldonium treatment (p < 0.001). Increased hepatic expression of genes involved in fatty acid oxidation and lipid transport was observed in the combination group compared to control, and increased gene expression of the mitochondrial uncoupling protein UCP2 was observed compared to the meldonium group. In addition, the product of fatty acid oxidation, acetylcarnitine, increased in plasma in metformin-treated mice. Altogether, metformin treatment influenced hepatic lipid metabolism and lowered plasma TAG in meldonium-induced fatty liver in mice.

Intracerebroventricular prokineticin 2 infusion may play a role on the hypothalamus-pituitary-thyroid axis and energy metabolism

AimThe hypothesis of this study is to determine the effects of intracerebroventricular (icv) prokineticin 2 infusion on food consumption and body weight and to elucidate whether it has effects on energy expenditure via the hypothalamus-pituitary-thyroid (HPT) axis in adipose tissue. Material and MethodsA total of 40 rats were used in the study and 4 groups were established: Control, Sham, Prokineticin 1.5 and Prokineticin 4.5 (n=10). Except for the Control group, rats were treated intracerebroventricularly via osmotic minipumps, the Sham group was infused with aCSF (vehicle), and the Prokineticin 1.5 and Prokineticin 4.5 groups were infused with 1.5 nMol and 4.5 nMol prokineticin 2, respectively. Food and water consumption and body weight were monitored during 7-day infusion in all groups. At the end of the infusion, the rats were decapitated and serum TSH, fT4 and fT3 levels were determined by ELISA. In addition, PGC-1α and UCP1 gene expression levels in white adipose tissue (WAT) and brown adipose tissue (BAT), TRH from rat hypothalamic tissue were determined by real-time PCR. ResultsIcv prokineticin 2 (4.5 nMol) infusion had no effect on water consumption but reduced daily food consumption and body weight (p<0.05). Icv prokineticin 2 (4.5 nMol) infusion significantly increased serum TSH, fT4 and fT3 levels when compared to Control and Sham groups (p<0.05). Also, icv prokineticin 2 (4.5 nMol) infusion increased the expression of TRH in the hypothalamus tissue and expression of PGC-1α UCP1 in the WAT and BAT (p<0.05). ConclusionIcv prokineticin 2 (4.5 nMol) infusion may suppress food consumption via its receptors in the hypothalamus and reduce body weight by stimulating energy expenditure and thermogenesis in adipose tissue through the HPT axis.

Effects of N-acetylcysteine on the expressions of UCP1 and factors related to thyroid function in visceral adipose tissue of obese adults: a randomized, double-blind clinical trial

BackgroundEvidences have shown that obesity is influenced by various factors, including various hormones such as thyroid hormones and the body’s metabolism rate. It seems that practical solutions such as weight loss diets and common drugs can affect these potential disorders. In this study, we investigate one of these common drugs, N-Acetylcysteine (NAC), on expressions of UCP1 and factors related to thyroid function in adults with obesity.Methods and analysisThe current investigation was carried out as a randomized clinical trial (RCT) including 43 adults with obesity who were potential candidates for bariatric surgery. These individuals were randomly divided into two groups: 600 mg of NAC (n = 22) or placebo (n = 21) for a duration of 8 weeks. Visceral adipose tissue was utilized in the context of bariatric surgery to investigate the gene expression of UCP1 and thyroid function. Polymerase chain reaction (PCR) was performed in duplicate for UCP1, DIO2, DIO3, THRα and β, and 18s RNA (as an internal control) using the provided instructions to investigate the expression of the respective genes.ResultsOur findings revealed that after 8 weeks compared to placebo, NAC caused a significant decrease in the expression of the DIO3 gene as one of the genes related to thyroid function and metabolism. However, regarding other related genes, no statistically significant was found (despite the increase in UCP1, DIO2, and THRα expression and decrease in THRβ expression). In addition, after adjustment of possible confounders, no significant effect was observed on anthropometric factors and serum levels of thyroid hormones.ConclusionThe results of this study indicate that, following an 8-week period, NAC effectively decreases the expression of the DIO3 gene in the visceral fat tissue, in comparison to the placebo.

High Salt Induced Alterations in Substrate Metabolism, Respiratory Activity, and Acidification in Isolated Proximal Tubules from Dahl Salt-Sensitive Rats

Rationale: The renal nephron actively reabsorbs nearly 99% of Na+ from the glomerular filtrate to maintain fluid and solute homeostasis, roughly 70% of which occurs in the proximal tubules (PT), where mitochondria consume a great amount of O2 for ATP production to meet the energy demand. However, the effect of a high salt diet upon the PT substrate metabolism and respiratory activity towards energy production and associated cellular acidification is not well-known. Method: To determine alterations in the PT substrate metabolism, respiratory activity, and acidification with a high salt diet, the PT of adult Dahl salt-sensitive (SS) rats were isolated by collagenase digestion and sieving with the rats fed either a 0.4% (LS) or a 4.0% (HS) NaCl diet for 7, 14 and 21 days (age-matched). Responses of the PT O2 consumption rate (OCR) and extracellular acidification rate (ECAR) were determined using a high-throughput Agilent Seahorse XF96 Extracellular Flux Analyzer and a modified mitochondrial stress test protocol, which combined a substrate addition step to the mitochondrial stress reagent addition steps. Basal OCR and ECAR were assessed with only amino acids (basic Seahorse medium) used as fuel for respiration. Subsequently, OCR and ECAR responses were determined by adding different circulating substrates followed by perturbations to the electron transport chain (ETC) in sequential order with oligomycin to inhibit ATP synthase, FCCP to uncouple oxidative phosphorylation, and rotenone + antimycin A to inhibit complexes I and III of the ETC. From these measurements, different OCR and ECAR parameters were derived for each substrate and each salt load condition. Results: The OCR data show that the PT of SS rats preferred to use lactate, glutamine, and palmitate for ATP production under the LS diet. However, the HS diet resulted in significantly reduced OCR when supplied with the same substrates. Interestingly, the basal OCR which occurred with amino acids as metabolic substrates was increased in the PT obtained from HS fed SS rats starting on day 7. These alterations in substrate metabolism were also apparent from the same parametric analysis of the ECAR data. An increased mitochondrial proton leak induced respiration was also deduced form both OCR and ECAR data under the HS diet. Since it is known that uncoupling proteins (UCP) and ADP/ATP translocase (ANT) enhance proton leak, gene expression was quantified from the isolated PT segments. Increased Ucp2 gene expression was found in response to the HS diet (days 7, 14, 21) compared to the LS fed SS rats but no changes were observed in the expression of Slc25A4 (ANT1) or Slc25A5 (ANT2). Summary: HS diet resulted in significant metabolic changes in the PT segments, including substrate metabolism, respiratory activity, and cellular acidification. HS diet also increased PT basal respiration and proton leak, which was associated with an increase of Ucp2 gene expression. Considering the increased ATP demand in the PT segments with a HS diet, these changes would result in increased O2 consumption and increased reactive oxygen species production. Together with the physiological changes on renal hemodynamics that we have observed, we propose that the observed metabolomic changes on the PT upon HS diet contribute to the onset of associated regional ischemia, tissue inflammation, and renal injury observed in hypertensive SS rats. NIH R01-HL151587. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Network Meta-Analysis: Effect of Cold Stress on the Gene Expression of Swine Adipocytes ATGL, CIDEA, UCP2, and UCP3.

Cold stress significantly affects gene expression in adipocytes; studying this phenomenon can help reveal the pathogeneses of conditions such as obesity and insulin resistance. Adipocyte triglyceride lipase (ATGL); cell death-inducing deoxyribonucleic acid (DNA) fragmentation factor subunit alpha (DFFA)-like effector (CIDEA); and uncoupling protein genes UCP1, UCP2, and UCP3 are the most studied genes in pig adipose tissues under cold stress. However, contradictory results have been observed in gene expression changes to UCP3 and UCP2 when adipose tissues under cold stress were examined. Therefore, we conducted a meta-analysis of 32 publications in total on the effect of cold stress on the expression of ATGL, CIDEA, UCP2, and UCP3. Our results showed that cold stress affected the expression of swine adipocyte genes; specifically, it was positively correlated with the expression of UCP3 in swine adipocytes. Conversely, expression of ATGL was negatively affected under cold stress conditions. In addition, the loss of functional UCP1 in pigs likely triggered a compensatory increase in UCP3 activity. We also simulated the docking results of UCP2 and UCP3. Our results showed that UCP2 could strongly bind to adenosine triphosphate (ATP), meaning that UCP3 played a more significant role in pig adipocytes.

Potential Role of Pig UCP3 in Modulating Adipocyte Browning via the Beta-Adrenergic Receptor Signaling Pathway.

Adipose tissue plays an important role in regulating body temperature and metabolism, with white adipocytes serving as storage units for energy. Recent research focused on the browning of white adipocytes (beige adipocytes), causing thermogenesis and lipolysis. The process of browning is linked to the activation of uncoupling protein (UCP) expression, which can be mediated by the β3 adrenergic receptor pathway. Transcriptional factors, such as peroxisome proliferator activated receptor γ (PPARγ) and PPARγ coactivator 1 alpha, play vital roles in cell fate determination for fat cells. Beige adipocytes have metabolic therapeutic potential to combat diseases such as obesity, diabetes mellitus, and dyslipidemia, owing to their significant impact on metabolic functions. However, the molecular mechanisms that cause the induction of browning are unclear. Therefore, research using animal models and primary culture is essential to provide an understanding of browning for further application in human metabolic studies. Pigs have physiological similarities to humans; hence, they are valuable models for research on adipose tissue. This study demonstrates the browning potential of pig white adipocytes through primary culture experiments. The results show that upregulation of UCP3 gene expression and fragmentation of lipid droplets into smaller particles occur due to isoproterenol stimulation, which activates beta-adrenergic receptor signaling. Furthermore, PPARγ and PGC-1α were found to activate the UCP3 promoter region, similar to that of UCP1. These findings suggest that pigs undergo metabolic changes that induce browning in white adipocytes, providing a promising approach for metabolic research with potential implications for human health. This study offers valuable insights into the mechanism of adipocyte browning using pig primary culture that can enhance our understanding of human metabolism, leading to cures for commonly occurring diseases.

Gene Regulation and Mitochondrial Activity During White and Brown Adipogenesis Are Modulated by KDM5 Histone Demethylase.

Body fat accumulation differs between males and females and is influenced by both gonadal sex (ovaries vs testes) and chromosomal sex (XX vs XY). We previously showed that an X chromosome gene, Kdm5c, is expressed at higher levels in females compared to males and correlates with adiposity in mice and humans. Kdm5c encodes a KDM5 histone demethylase that regulates gene expression by modulating histone methylation at gene promoters and enhancers. Here, we use chemical inhibition and genetic knockdown to identify a role for KDM5 activity during early stages of white and brown preadipocyte differentiation, with specific effects on white adipocyte clonal expansion, and white and brown adipocyte gene expression and mitochondrial activity. In white adipogenesis, KDM5 activity modulates H3K4 histone methylation at the Dlk1 gene promoter to repress gene expression and promote progression from preadipocytes to mature adipocytes. In brown adipogenesis, KDM5 activity modulates H3K4 methylation and gene expression of Ucp1, which is required for thermogenesis. Unbiased transcriptome analysis revealed that KDM5 activity regulates genes associated with cell cycle regulation and mitochondrial function, and this was confirmed by functional analyses of cell proliferation and cellular bioenergetics. Using genetic knockdown, we demonstrate that KDM5C is the likely KDM5 family member that is responsible for regulation of white and brown preadipocyte programming. Given that KDM5C levels are higher in females compared to males, our findings suggest that sex differences in white and brown preadipocyte gene regulation may contribute to sex differences in adipose tissue function.

P020 Effects of Anti-TNF Treatment on Browning of Mesenteric Adipose Tissue with Crohn's Disease

Abstract Background Crohn's disease (CD) is characterized by the expansion of mesenteric fat, known as creeping fat (CrF), to the inflamed segments of the intestine. Our group observed that CrF showed a conversion to beige tissue, a phenomenon known as "Browning", characterized by an elevated gene expression of thermogenin (UCP-1), the gene characteristic of browning1. A recent study also showed that when browning was induced in mice in a TNBS colitis model, mesenteric hypertrophy improved and inflammation in adipose tissue was reduced2. The aim of this study is to assess whether the administration of anti-TNF biologic treatment (infliximab) in patients with CD is related to the increase in adipose beige tissue in the CrF. Methods Immunohistochemistry staining of UCP-1 was conducted on CrF samples from CD patients receiving anti-TNF treatment (≥6 months) and anti-TNF-naïve patients. Additionally, we analysed the gene expression of beige adipose markers in CrF from CD patients treated with anti-TNF drugs, comparing them to those untreated. UCP-1 gene expression was also studied in adipose-stem cells isolated from CrF. Ongoing experiments involve treating adipose stem cells with infliximab (10ug/ml) for 24 hours to assess the potential conversion of white to beige adipose tissue. Results The study revealed a significant increase in UCP-1 staining in CrF samples among patients receiving anti-TNF treatment compared to anti-TNF-naïve CD patients (Fig 1.A). This trend was consistently observed in mesenteric CrF tissue. Beige markers TMEM26 and CPTB1 exhibited significant increases in anti-TNF-treated CrF, and other beige tissue markers showed a notable trend (Fig 1.B). Adipose stem cells displayed a significant increase in UCP-1 gene expression in anti-TNF-treated CrF compared to untreated patients (Fig 1.C). Exciting preliminary data suggest that infliximab treatment increases UCP-1 and the anti-inflammatory cytokine IL-4 gene expression in adipose-stem cells from active CD patients (Fig 1.D). This novel data implies a direct relationship between anti-TNF treatment and heightened browning in white adipose tissue of CD patients. Conclusion This study reveals a notable increase in UCP-1 gene expression in adipose tissue CrF of CD patients undergoing anti-TNF treatment. The findings suggest that anti-TNF therapy may trigger the transformation of white adipose tissue into the "beige" type, potentially mitigating inflammation. Browning CrF presents a promising therapeutic avenue for CD management, warranting further investigation. Ref: 1. D. Monfort-Ferré et al. J Crohn Colitis., 2022;16(10):1571–83, 2. Zuo L et al. J Crohn Colitis. 2023 21;17(8):1179-1192.

Differential gene expression of blood-based ABCA9, CNOT8, SESN1, UCP3, MAP2K1 and DDIT4 in Alzheimer’s disease

This study uncovered differential gene expression in blood to distinguish subjects with probable Alzheimer’s disease (AD) from normal elderly participants (non-demented controls, NDC). The participants were recruited via training (Phase 1) and validation cohorts (Phase 2). The changes of gene expression in blood samples from the training cohort (92 AD vs 92 NDC) were assessed using the microarray technology. The Partial Least Square Discrimination Analysis (PLSDA) was then used to develop a disease classifier algorithm (accuracy = 88.3%). Six differentially expressed genes were validated through RT-qPCR using blood samples from the validation cohort [(25 AD, 25 NDC, 12 mild cognitive impairment (MCI) and 12 vascular dementia (VaD) subjects] . The PLSDA model indicated a good separation between AD and NDC [area under the receiver operating characteristic curve (ROC AUC) = 0.88]. ABCA9, CNOT8, SESN1, UCP3, MAP2K1 and DDIT4 were found to be differentially expressed between the two groups. Validation of the panel of six genes gave an overall accuracy of 82.0% (AUC=0.86). The ABCA9 mRNA level, which was significantly (p &lt; 0.05) lower in the AD group, correctly classified 90.9% of all subjects (AUC=0.94). This group of genes may be responsible for dysregulation of pathways related to inflammation, mitochondrial dysfunction, oxidative injury, DNA damage, apoptosis and lipid metabolism. The disease classifier algorithm discriminated probable AD from MCI and VaD at specificity of 83.3% and 75.0%, respectively. These findings warrant further validation of potential blood-based biomarkers in larger samples of clinical AD.

The splicing factor SF3B1 is involved in brown adipocyte thermogenic activation

The ability of alternative splicing mechanisms to control gene expression is increasingly being recognized as relevant for adipose tissue function. The expression of SF3B1, a key component of the SF3B complex directly involved in spliceosome formation, was previously reported to be significantly induced in brown adipose tissue under cold-induced thermogenic activation. Here, we identify that noradrenergic cAMP-mediated thermogenic stimulation increases SF3B1 expression in brown and beige adipocytes. We further show that pladienolide-B, a drug that binds SF3B1 to inhibit pre-mRNA splicing by targeting the SF3B complex, down-regulates key components of the thermogenic machinery (e.g., UCP1 gene expression), differentially alters the expression of alternative splicing-regulated transcripts encoding molecular actors involved in the oxidative metabolism of brown adipocytes (e.g., peroxisome proliferator-activated receptor-gamma co-activator-alpha [PGC-1α] and cytochrome oxidase subunit 7a genes), and impairs the respiratory activity of brown adipocytes. Similar alterations were found in brown adipocytes with siRNA-mediated knockdown of SF3B1 protein levels. Our findings collectively indicate that SF3B1 is a key factor in the appropriate thermogenic activation of differentiated brown adipocytes. This work exemplifies the importance of splicing processes in adaptive thermogenesis and suggests that pharmacological tools, such as pladienolide-B, may be used to modulate brown adipocyte thermogenic activity.

The effect of endurance training combined with adenosine on the gene expression of UCP-1 and MAPK p38 in subcutaneous adipose tissue of male Wistar rats fed a high -fat diet

Background: Strategies to increase energy expenditure are an attractive approach to reduce excess fat storage and body weight to improve metabolic health. The aim of the present study was to investigate the effects of endurance training combined with adenosine injection on the gene expression of UCP-1 and MAPK p38 in the subcutaneous adipose tissue of male rats fed a high-fat diet. Materials and Methods: Forty rats were randomly divided into 4 groups: 1. normal control, 2. high-fat diet (HFD) control, 3. HFD + adenosine, and 4. HFD + endurance training + adenosine. After 13 weeks of HFD, 12 weeks of endurance training on a moderate-intensity treadmill was performed. UCP-1 and MAPK p38 mRNA levels were measured by RT-PCR. Results: A significant increase in UCP-1 was observed with in HFD + endurance training + adenosine and HFD + adenosine compared to normal and HFD controls. A significant decrease in MAPK p38 was also observed with HFD + endurance training + adenosine and HFD + adenosine compared to HFD. Conclusion: Endurance training and adenosine are likely activators of UCP-1 gene expression and can be used as effective lipolytic agents in obesity. The MAPK p38 pathway increases glucose uptake by insulin and also induces oxidative phosphorylation in mitochondria following a healthy diet and aerobic activity.

Crosstalk between corepressor NRIP1 and cAMP signaling on adipocyte thermogenic programming

ObjectivesNuclear receptor interacting protein 1 (NRIP1) suppresses energy expenditure via repression of nuclear receptors, and its depletion markedly elevates uncoupled respiration in mouse and human adipocytes. We tested whether NRIP1 deficient adipocytes implanted into obese mice would enhance whole body metabolism. Since β-adrenergic signaling through cAMP strongly promotes adipocyte thermogenesis, we tested whether the effects of NRIP1 knock-out (NRIP1KO) require the cAMP pathway. MethodsNRIP1KO adipocytes were implanted in recipient high-fat diet (HFD) fed mice and metabolic cage studies conducted. The Nrip1 gene was disrupted by CRISPR in primary preadipocytes isolated from control vs adipose selective GsαKO (cAdGsαKO) mice prior to differentiation to adipocytes. Protein kinase A inhibitor was also used. ResultsImplanting NRIP1KO adipocytes into HFD fed mice enhanced whole-body glucose tolerance by increasing insulin sensitivity, reducing adiposity, and enhancing energy expenditure in the recipients. NRIP1 depletion in both control and GsαKO adipocytes was equally effective in upregulating uncoupling protein 1 (UCP1) and adipocyte beiging, while β-adrenergic signaling by CL 316,243 was abolished in GsαKO adipocytes. Combining NRIP1KO with CL 316,243 treatment synergistically increased Ucp1 gene expression and increased the adipocyte subpopulation responsive to beiging. Estrogen-related receptor α (ERRα) was dispensable for UCP1 upregulation by NRIPKO. ConclusionsThe thermogenic effect of NRIP1 depletion in adipocytes causes systemic enhancement of energy expenditure when such adipocytes are implanted into obese mice. Furthermore, NRIP1KO acts independently but cooperatively with the cAMP pathway in mediating its effect on adipocyte beiging.

Transcriptomic Analysis Reveals Fibroblast Growth Factor 11 (FGF11) Role in Brown Adipocytes in Thermogenic Regulation of Goats.

Brown adipose tissue (BAT) is the main site of adaptive thermogenesis, generates heat to maintain body temperature upon cold exposure, and protects against obesity by promoting energy expenditure. RNA-seq analysis revealed that FGF11 is enriched in BAT. However, the functions and regulatory mechanisms of FGF11 in BAT thermogenesis are still limited. In this study, we found that FGF11 was significantly enriched in goat BAT compared with white adipose tissue (WAT). Gain- and loss-of-function experiments revealed that FGF11 promoted differentiation and thermogenesis in brown adipocytes. However, FGF11 had no effect on white adipocyte differentiation. Furthermore, FGF11 promoted the expression of the UCP1 protein and an EBF2 element was responsible for UCP1 promoter activity. Additionally, FGF11 induced UCP1 gene expression through promoting EBF2 binding to the UCP1 promoter. These results revealed that FGF11 promotes differentiation and thermogenesis in brown adipocytes but not in white adipocytes of goats. These findings provide evidence for FGF11 and transcription factor regulatory functions in controlling brown adipose thermogenesis of goats.

Effects of aerobic training and vitamin D supplementation on glycemic indices and adipose tissue gene expression in type 2 diabetic rats

Type 2 diabetes mellitus (T2DM) is a progressive metabolic disorder mainly caused by overweight and obesity that accumulates pro-inflammatory factors in adipose tissue. Studies have confirmed the efficacy of exercise and vitamin D supplementation in preventing, controlling, and treating diabetes. While, reduced physical activity and vitamin D deficiency are related to increased adiposity, blood glucose level, insulin concentration, and insulin resistance. This study purposed to investigate the effect of 8-week aerobic training with vitamin D supplementation on the expression of AMPK, PGC-1α, and UCP-1 genes expression in the visceral adipose tissue of obese rats with T2DM. In this experimental study, fifty male Wistar rats were divided into 5 groups (n = 10): aerobic training and vitamin D supplementation (AT + Vit D), aerobic training (5 days/week for 8 weeks; AT), vitamin D supplementation (Vit D), diabetic control (C) and NC (Non-Diabetic Control). AT + Vit D and AT groups practiced an 8-week aerobic training, 5 days a week. Vit D and AT + Vit D groups receive 5000 IU of vitamin D by injection once a week while AT and C received sesame oil. After blood sampling, visceral fat was taken to measure AMPK, PGC-1α, and UCP1 gene expression. Data were statistically analyzed by One-way ANOVA and paired sample t-test at a significance level of p < 0.05. Based on our results BW, BMI, WC, visceral fat, insulin, glucose, and HOMA-IR were significantly lower in the AT + Vit D, AT, and Vit D groups compared with the C group (p < 0.01). Furthermore, AT + Vit D, AT, and Vit D upregulated AMPK, PGC-1α, and UCP1 gene expression compared to the C. Based on the results compared to AT and Vit D, AT + Vit D significantly upregulated AMPK (p = 0.004; p = 0.001), PGC-1α (p = 0.010; p = 0.001), and UCP1 (p = 0.032; p = 0.001) gene expression, respectively. Also, AT induced more significant upregulations in the AMPK (p = 0.001), PGC-1α (p = 0.001), and UCP1 gene expression (p = 0.001) than Vit D. Vitamin D supplementation enhanced the beneficial effects of aerobic training on BW, BMI, WC, visceral fat, insulin, glucose, and HOMA-IR in diabetic rats. We also observed that separate AT or Vit D upregulated the gene expression of AMPK, PGC-1α, and UCP1 however, combined AT + Vit D upregulated AMPK, PGC-1α, and UCP1 more significantly. These results suggested that combining aerobic training and vitamin D supplementation exerted incremental effects on the gene expressions related to adipose tissue in animal models of diabetes.