Uncoupling Protein Gene Expression Research Articles

Cell-autonomous Action of the FGF19 Promotes UCP1 Expression and Function in Human Brown Adipocytes

Fibroblast growth factor 19 (FGF19) is an intestine-derived hormone that regulates glucose and energy metabolism. Central and systemic administration of human FGF19 in mice promotes increased energy expenditure and body weight loss through mechanisms that are not fully understood. In this study, we investigated whether FGF19 can activate thermogenesis in brown adipocytes (BA) in a cell-autonomous manner. We differentiated immortalized human brown preadipocytes into mature adipocytes with adipogenic induction media in the presence and absence of FGF19 for 18 days to evaluate the effects of FGF19 on adipogenesis and thermogenesis. Through qPCR and RNA-sequencing analyses, we observed that FGF19 receptors were expressed in both brown preadipocytes and mature BA. However, the obligatory FGF19 co-receptor, β-klotho, was not expressed in preadipocytes, suggesting that the effects of FGF19 must occur preferentially in mature BA. Lipid staining with Oil Red O as well as gene expression of the adipogenic markers fatty acid binding protein (FABP4) and peroxisome proliferator activated receptor-γ (PPAR-γ) showed that adipogenesis was not affected by FGF19. We then treated mature BA with FGF19 (100 ng/mL) acutely and chronically to evaluate FGF19-induced changes in signaling, gene transcription, and thermogenic function. FGF19 signaling was assessed by measuring ERK1/2 phosphorylation levels, which increased within 5 min and remained elevated for at least 30 min after treatment. Using Seahorse assays, we observed that 24-hour FGF19 treatment promoted increased basal respiration, ATP production, and proton leak in human BA, indictive of enhanced mitochondrial function. Since proton leak across the inner membrane through the uncoupling protein 1 (UCP1) generates heat, we assessed the expression of UCP1 and other thermogenic genes. Interestingly, FGF19 treatment specifically increased UCP1 gene expression without affecting other classical adrenergic-mediated thermogenic genes, such as deiodinase 2 (DIO2), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α), PR domain containing 16 (PRDM16), and cell death-inducing DNA fragmentation factor A (CIDEA). These findings suggest that FGF19 regulates UCP1 expression through non-canonical pathways. Future work will elucidate the mechanism by which FGF19 promotes UCP1 gene expression in mature BA. Taken together, FGF19 stimulates ERK1/2 phosphorylation and UCP1 expression in human BA, leading to enhanced mitochondrial respiration. These results provide new mechanistic insights into FGF19’s effects on metabolic regulation. Topic subcategories: Adipocyte biology. Funding sources: Sao Paulo Research Foundation (FAPESP): 2022/15148-2 and NIH R01 DK102898. 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.

The Role of Acetyl-CoA Synthetase Short Chain Family Member-1 on Adipocyte Thermogenic Capacity

Obesity is characterized by an increase in adipose mass and is the leading risk factor for type 2 diabetes. Recent research suggests that activation of brown or beige fat and white adipose tissue browning represent a new therapeutic strategy for metabolic diseases. Fatty acid oxidation is required for the browning of white adipose tissue (WAT) and the induction of uncoupling protein 1 (UCP1) in WAT. The Acyl-CoA Synthetase Short Chain Family Member-1 (ACSS1), an established SIRT3 deacetylation target, is central to fatty acid oxidation (FAO) and mitochondrial bioenergetics by converting acetate and CoA to acetyl-CoA. However, the biological function of ACSS1 acetylation (ACSS1-Ac) in thermogenic adipose tissue and how it contributes to metabolic changes in adipocytes has not been investigated. We have generated a novel acetylation mimic mouse where lysine 635 (K635) was mutated to glutamine (K635Q), representing constitutive ACSS1-K635-Ac. Male mice expressing Acss1 K635Q/K635Q exhibited a reduction in size and body weight. Upon 48-hour fasting, these mice exhibited hypothermia as well as decreased ATP and lactate levels. Interestingly, UCP1 gene expression was upregulated in brown adipose tissue (BAT) of the Acss1 K635Q/K635Q compared to WT and also in WAT from fasted animals. Differentiated beige adipocytes also showed higher UCP1, PGC1a and adiponectin gene expression in cells isolated from Acss1 K635Q/K635Q mice compared to WT cells. Oxygen consumption rate of these cells was lower with lower basal and ATP-coupled respiration. Acss1 K635Q/K635Q beige adipocytes failed to respond to beta-adrenergic stimulation and did not increase their respiration capacity when compared to WT cells. No differences were observed in glucose uptake and lipolysis functional assays. These results suggest that the mutation leads to a disruption of downstream signaling of UCP1. In conclusion, ACSS1-K635-Ac is a novel thermoregulator in adipose tissue that could lead to further development of new therapies for metabolic diseases. 1. Mays Cancer Center CCSG (P30 CA054174); 2. National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health, under Award Number F32-0DK122754 This is the full abstract presented at the American Physiology Summit 2023 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.

Anti-Inflammatory, Antioxidant, and WAT/BAT-Conversion Stimulation Induced by Novel PPAR Ligands: Results from Ex Vivo and In Vitro Studies.

Activation of peroxisome proliferator-activated receptors (PPARs) not only regulates multiple metabolic pathways, but mediates various biological effects related to inflammation and oxidative stress. We investigated the effects of four new PPAR ligands containing a fibrate scaffold-the PPAR agonists (1a (αEC50 1.0 μM) and 1b (γEC50 0.012 μM)) and antagonists (2a (αIC50 6.5 μM) and 2b (αIC50 0.98 μM, with a weak antagonist activity on γ isoform))-on proinflammatory and oxidative stress biomarkers. The PPAR ligands 1a-b and 2a-b (0.1-10 μM) were tested on isolated liver specimens treated with lipopolysaccharide (LPS), and the levels of lactate dehydrogenase (LDH), prostaglandin (PG) E2, and 8-iso-PGF2α were measured. The effects of these compounds on the gene expression of the adipose tissue markers of browning, PPARα, and PPARγ, in white adipocytes, were evaluated as well. We found a significant reduction in LPS-induced LDH, PGE2, and 8-iso-PGF2α levels after 1a treatment. On the other hand, 1b decreased LPS-induced LDH activity. Compared to the control, 1a stimulated uncoupling protein 1 (UCP1), PR-(PRD1-BF1-RIZ1 homologous) domain containing 16 (PRDM16), deiodinase type II (DIO2), and PPARα and PPARγ gene expression, in 3T3-L1 cells. Similarly, 1b increased UCP1, DIO2, and PPARγ gene expression. 2a-b caused a reduction in the gene expression of UCP1, PRDM16, and DIO2 when tested at 10 μM. In addition, 2a-b significantly decreased PPARα gene expression. A significant reduction in PPARγ gene expression was also found after 2b treatment. The novel PPARα agonist 1a might be a promising lead compound and represents a valuable pharmacological tool for further assessment. The PPARγ agonist 1b could play a minor role in the regulation of inflammatory pathways.

Transplantation of Adipose-Tissue-Engineered Constructs with CRISPR-Mediated UCP1 Activation.

Thermogenic adipocytes have potential utility for the development of approaches to treat type 2 diabetes and obesity-associated diseases. Although several reports have proved the positive effect of beige and brown adipocyte transplantation in obese mice, translation to human cell therapy needs improvement. Here, we describe the application of CRISPR activation (CRISPRa) technology for generating safe and efficient adipose-tissue-engineered constructs with enhanced mitochondrial uncoupling protein 1 (UCP1) expression. We designed the CRISPRa system for the activation of UCP1 gene expression. CRISPRa-UCP1 was delivered into mature adipocytes by a baculovirus vector. Modified adipocytes were transplanted in C57BL/6 mice, followed by analysis of grafts, inflammation and systemic glucose metabolism. Staining of grafts on day 8 after transplantation shows them to contain UCP1-positive adipocytes. Following transplantation, adipocytes remain in grafts and exhibit expression of PGC1α transcription factor and hormone sensitive lipase (HSL). Transplantation of CRISPRa-UCP1-modified adipocytes does not influence glucose metabolism or inflammation in recipient mice. We show the utility and safety of baculovirus vectors for CRISPRa-based thermogenic gene activation. Our findings suggest a means of improving existing cell therapy approaches using baculovirus vectors and CRISPRa for modification and transplantation of non-immunogenic adipocytes.

Mitochondrial uncoupling protein 2 (UCP2) gene polymorphism - 866 G/A in the promoter region is associated with type 2 diabetes mellitus among Kashmiri population of Northern India.

The study aimed to evaluate the association of UCP2 gene polymorphism - 866 G/A and its expression with diabetes predisposition in the North Indian population. The study involved 850 subjects, including 425 each T2DM and control subjects. The serum metabolic and clinical parameters were estimated using standard protocols. The PCR-RFLP based genotyping was performed to determine UCP2 gene polymorphism, while the expression was measured by real-time quantitative PCR. The genotypic and allelic frequencies showed a significant difference in cases compared to controls (p < 0.05). The diabetes patients had a 4.2-fold decrease in UCP2 gene expression. The expression was 29.8 and 8.4 fold lower in diabetes patients with homozygous (AA) and heterozygous (GA) mutation at - 866 locus of UCP2 nucleotide sequence, respectively. When categorized according to age and BMI, the T2DM subjects with age ≥ 50 and BMI ≥ 25 had a 5.53 and 8.2-fold decrease in UCP2 expression, respectively. The diabetes subjects with homozygous and heterozygous mutation demonstrated a pathological increase in serum metabolic and clinical parameters, which corroborated with UCP2 gene expression, indicating a strong association between the two. Intriguingly, we did not find any association between - 866 G/A polymorphism of UCP2 with serum insulin levels. Our investigation is the first among the studies conducted in Jammu and Kashmir to work on adipose tissue and UCP2 gene polymorphism. The association of - 866 G/A SNP of the UCP2 gene with its expression in diabetes patients appears to be an important genetic determinant in the progression of T2DM. Moreover, age ≥ 50years and BMI ≥ 25 could be considered risk factors for developing T2DM in the studied population.

Histone deacetylase (HDAC) inhibitor curcumin upregulates mitochondrial uncoupling protein1 (UCP1) and mitochondrial function in brown adipocytes, in-silico study and screening natural drug library

Mitochondrial dysfunction has been associated with diverse pathological conditions globally. Specifically, in adipose tissues, mitochondrial dysfunction is the primary cause of obesity and obesity-related illnesses. An existing drugs such as atorvastatin and other lipid-lowering drugs demonstrated adverse effects and initiated other diseases. Thus, we need to explore new methods to prevent and treat obesity. In this study, we used the cell screening method to identify several natural compounds that increase adipocyte UCP1 gene expression. The identified drug Curcumin was evaluated in cell models and the In-silico model. We found curcumin is an active compound of turmeric belonging to Zingiberaceae (ginger family), which activates the Nrf2 mechanism. Curcumin potentially endorses the expression of UCP1 in the brown adipocyte in vitro cellular model. Curcumin plays an important role that modulating mitochondrial function and improving mitochondrial DNA quantification, ATP production, and cell viability. We have established an efficient in vitro cell experiment system to study the metabolic regulation of UCP1. The in-silico model revealed curcumin-UCP1 interaction. Curcumin, via enhancing mitochondrial activity, could be a helpful therapeutic molecule against metabolic disorders or obesity-related diseases. Curcumin will be the subject of more research in both human and murine models, which will provide novel therapeutic pathways for the treatment of metabolic illnesses by modulating the control of mitochondrial function.

Baicalein modulates mitochondrial function by upregulating mitochondrial uncoupling protein-1 (UCP1) expression in brown adipocytes, cytotoxicity, and computational studies

BackgroundObesity, fatty liver, type 2 diabetes, and Non-alcoholic fatty liver disease (NAFLD) are all metabolic diseases caused by excess food consumption. Existing drug molecules had negative side effects and caused other diseases to develop (Orlistat causes angioedema, and menstrual irregularities; megestrol acetate causes hypertension, and insomnia). By enhancing lipid consumption and increasing nonshivering thermogenesis, targeting mitochondrial uncoupling protein-1 (UCP1) expression in adipocytes could be an auspicious treatment strategy against obesity or metabolic disorders associated with obesity. MethodsWe used previously produced UCP1-A-GFP reporter cell lines in this investigation to find new pharmacological compounds against obesity or metabolic syndrome, which we then tested in cellular analysis, cytotoxicity, mitochondrial function, mitochondrial DNA quantification, mitochondrial ATP production, and in-silico models. ResultsBaicalein was discovered to play a critical role in obesity prevention via altering mitochondrial function. Baicalein lowers ATP generation while increasing considerable UCP1 gene expression in brown adipocytes. As a result, cellular thermogenesis is boosted. The HEK293T cell line is harmless by baicalein. The investigation by the in-silico study revealed drug-protein interaction and UCP1 binding. Thus, our research clarifies baicalein's therapeutic role in metabolic and obesity-related illnesses via modulating mitochondrial activity (Supplementary Fig. 2). ConclusionsFurther studies are required in both murine and human models to understand the full mechanism of action by mitochondrial modulation. Drug development investigation also requires to development of a precise formulation.

Epigenetic drug (XL019) JAK2 inhibitor increases mitochondrial function in brown adipocytes by upregulating mitochondrial uncoupling protein 1 (UCP1), screening of epigenetic drug libraries, cell viability, and in-silico studies

BackgroundAt present lacking of effective and safe anti-obesity drugs available leads to initiate obesity worldwide that promotes several diseases like cardiovascular diseases, liver diseases, and NASH. The development of new therapeutics is an emergency demand to cure obesity-related diseases. Mitochondrial uncoupling protein 1 (UCP1) gene could be a potential target to develop new drug moieties that can treat obesity-related diseases. MethodsWe used a GFP reporter cell line to screen epigenetic drug libraries to identify UCP1 regulators that could be effective drug candidates to treat obesity-related diseases. In this study, we employed an in-silico study that revealed drug-protein interaction and stability of drugs with protein. ResultsScreening epigenetic drug libraries, we identified XL019 significant TYK2, JAK2, and JAK3, inhibitors that can significantly promote UCP1 gene expression in brown adipocytes. Here, we found that XL019 plays a vital role to modulates mitochondrial function and could be beneficial against obesity. Further analysis shows that XL019 significantly improved mitochondrial ATP production and mitochondrial DNA copy number of adipocytes compared with the control group. The in-silico study demonstrated drug-protein interaction and binding side with UCP1 gene. Thus XL019 improves mitochondrial function that would be effective drug candidate to treat metabolic diseases and obesity-related diseases. ConclusionIn this study, we confirm the potential effect of the XL019 epigenetic drug that modulates mitochondrial function and in-silico study on drug-likeness, stability, and safety profile. Further investigation will reveal the new insight into the mechanism of action against obesity, metabolic diseases ( NASH, Fibrosis, cardiac diseases and so on), by modulation of the mitochondrial UCP1 gene and mitochondrial function.

Plasmalogen Inhibits Body Weight Gain by Activating Brown Adipose Tissue and Improving White Adipose Tissue Metabolism.

Plasmalogen, a phospholipid, exhibits preventive and therapeutic effects on dementia. Phospholipids improve fat metabolism, but it is unknown whether plasmalogen has an effect on fat metabolism. In this study, the effects of plasmalogen were determined by administering plasmalogen to KK-Ay mice. As a result, weight gain was significantly suppressed in the plasmalogen-treated group compared with the control group from 7 wk after the start of administration. In addition, plasmalogen administration increased uncoupling protein 1 (UCP1) expression in brown adipose tissue. The effect is thought to result from liver kinase B1 (LKB1)/AMP-activated protein kinase (AMPK)/PR domain containing 16 (PRDM16)/peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) pathway activation via adrenergic β3 receptors. Furthermore, the expression of the carnitine palmitoyltransferase-1 (CPT-1) gene associated with thermogenic factors and β-oxidation was increased. We investigated the browning of white adipose tissue, but no increase in UCP1 gene expression was observed in perirenal adipose tissue, epididymis adipose tissue, mesenteric adipose tissue and inguinal region white adipose tissue. In contrast, plasmalogen increased the activity of AMPK, which is a central enzyme in lipid metabolism, in perirenal adipose tissue. Furthermore, the activity of the protein kinase A (PKA)/LKB1/AMPK/acetyl-coenzyme A carboxylase (ACC), stearoyl-CoA desaturase-1 (SCD-1), and hormone-sensitive lipase (HSL) pathways was confirmed. Plasmalogen may inhibit weight gain by activating brown fat to increase heat production, inhibiting lipid synthesis, and promoting lipolysis in white fat.

Effects of maternal feed intake restriction on the blood parameters, fatty acid profile and lipogenetic genes expression of perirenal fat in offspring kids

Maternal nutritional restriction impacted lipogenic gene expression in adipose tissue of offspring, but the association of this programming with DNA methylation is not yet clear. Therefore, this experiment aimed to investigate the effects of maternal feed intake restriction on offsprings’ blood indexes, lipid metabolism of perirenal adipose tissue (PAT) and DNA methylation of lipogenic genes. Blood and PAT were collected from the fetuses (at d 100 of gestation) and kids (at d 90 after birth). Maternal undernutrition (at d 45 to d 100) decreases heart and kidney weight of kid goats after birth. Maternal undernutrition decreased the content of leptin in the umbilical cord blood of fetuses. The expression of uncoupling protein 1 (UCP1) was decreased in fetal PAT of the restriction group, but fatty acid synthetase (FASN) was increased. Protein abundance of UCP1 and FASN was down-regulated in the fetal PAT from the restriction group. Furthermore, only the methylation level of the CpG site (from −756 to −757 bp) in the promoter region of FASN gene was increased for the fetal PAT from the restriction group. These results revealed that maternal feed intake restriction influenced the leptin secretion, changed the expression of FASN and UCP1 gene of fetal PAT. This alteration was able to recover in the kids after removing intake restriction, but the growth performance and visceral organ mass were still impaired, suggesting abnormal fat metabolism may happen in the future.

Long-term GABA administration improves FNDC5, TFAM, and UCP3 mRNA expressions in the skeletal muscle and serum irisin levels in chronic type 2 diabetic rats.

In this study, we aimed to investigate whether the anti-diabetic effects of γ-aminobutyric acid (GABA) and insulin can be mediated through the regulation of gene expression related to irisin production and mitochondrial biogenesis in type 2 diabetic mellitus (T2DM) rats. Four groups (n = 6) were used in this study: control, T2DM, T2DM + insulin, and T2DM + GABA groups. After T2DM induction for 3months (high-fat diet + 35mg/kg streptozotocin) and treatment with GABA or insulin for 3months, circulating levels of FBG, triglyceride, LDL, Ox-LDL, and insulin as well as hepatic and serum irisin levels were measured. The mRNA expressions of fibronectin type III domain-containing protein 5 (FNDC5), mitochondrialtranscription factor A (TFAM), and mitochondrial uncoupling protein 3 (UCP3) were also evaluated in the skeletal muscle of all groups. GABA therapy improved the FBG and insulin levels in diabetic rats. Insulin treatment significantly reduced FBG and failed to maintain glucose close to the control level. Insulin or GABA therapy significantly decreased the levels of LDL, Ox-LDL, and HOMA-IR index. Circulating irisin levels were markedly decreased in insulin-treated group, while irisin levels did not show significant changes in GABA-treated group compared with control group. GABA or insulin therapy increased mRNA expressions of TFAM and UCP3 in diabetic rats. GABA therapy also led to a significant increase in FNDC5 mRNA. Our findings suggest that the anti-diabetic effect of GABA may be mediated, in part, by a decrease in Ox-LDL levels and an increase in the levels of irisin as well as FNDC5, TFAM, and UCP3 gene expression in T2DM rats.

Increased expression level of ANGPTL8 in white adipose tissue under acute and chronic cold treatment

BackgroundAngiopoietin-like proteins (ANGPTL), primarily 3, 4, and 8, play a major role in maintaining energy homeostasis by regulating triglyceride metabolism. This study evaluated the level of ANGPTL3, 4, and 8 in the liver, brown adipose tissue (BAT), and subcutaneous white adipose tissue (SAT) of mice maintained under acute and chronic cold conditions.MethodsC57BL/6J mice were exposed to cold temperature (4 °C) for 10 days with food provided ad libitum. Animal tissues were harvested at Day 0 (Control group, n = 5) and Days 1, 3, 5, and 10 (cold treatment groups, n = 10 per group). The expression levels of various genes were measured in the liver, SAT, and BAT. ANGPTL3, 4, and 8 expressions were measured in the liver. ANGPTL4, 8, and genes involved in browning and lipid metabolism [uncoupling protein 1 (UCP1), lipoprotein lipase (LPL), and adipose triglyceride lipase (ATGL)] were measured in SAT and BAT. Western blotting (WB) analysis and immunohistochemistry (IHC) were performed to confirm ANGPTL8 expression in these tissues.ResultsThe expressions of ANGPTL3 and 8 mRNA were significantly reduced in mouse liver tissues after cold treatment (P < 0.05); however, the expression of ANGPTL4 was not significantly altered. In BAT, ANGPTL8 expression was unchanged after cold treatment, whereas ANGPTL4 expression was significantly reduced (P < 0.05). ANGPTL4 levels were also significantly reduced in SAT, whereas ANGPTL8 gene expression exhibited over a 5-fold increase. Similarly, UCP1 gene expression was also significantly increased in SAT. The mRNA levels of LPL and ATGL showed an initial increase followed by a gradual decrease with an increase in the days of cold exposure. ANGPTL8 protein overexpression was further confirmed by WB and IHC.ConclusionsThis study shows that exposure to acute and chronic cold treatment results in the differential expression of ANGPTL proteins in the liver and adipose tissues (SAT and BAT). The results show a significant reduction in ANGPTL4 in BAT, which is linked to improved thermogenesis in response to acute cold exposure. ANGPTL8 was activated under acute and chronic cold conditions in SAT, suggesting that it is involved in regulating lipolysis and enhancing SAT browning.

Glucocorticoid maturation of mitochondrial respiratory capacity in skeletal muscle before birth.

In adults, glucocorticoids act to match the supply and demand for energy during physiological challenges, partly through actions on tissue mitochondrial oxidative phosphorylation (OXPHOS) capacity. However, little is known about the role of the natural prepartum rise in fetal glucocorticoid concentrations in preparing tissues for the increased postnatal energy demands. This study examined the effect of manipulating cortisol concentrations in fetal sheep during late gestation on mitochondrial OXPHOS capacity of two skeletal muscles with different postnatal locomotive functions. Mitochondrial content, biogenesis markers, respiratory rates and expression of proteins and genes involved in the electron transfer system (ETS) and OXPHOS efficiency were measured in the biceps femoris (BF) and superficial digital flexor (SDF) of fetuses either infused with cortisol before the prepartum rise or adrenalectomised to prevent this increment. Cortisol infusion increased mitochondrial content, biogenesis markers, substrate-specific respiration rates and abundance of ETS complex I and adenine nucleotide translocator (ANT1) in a muscle-specific manner that was more pronounced in the SDF than BF. Adrenalectomy reduced mitochondrial content and expression of PGC1α and ANT1 in both muscles, and ETS complex IV abundance in the SDF near term. Uncoupling protein gene expression was unaffected by cortisol manipulations in both muscles. Gene expression of the myosin heavy chain isoform, MHCIIx, was increased by cortisol infusion and reduced by adrenalectomy in the BF alone. These findings show that cortisol has a muscle-specific role in prepartum maturation of mitochondrial OXPHOS capacity with important implications for the health of neonates born pre-term or after intrauterine glucocorticoid overexposure.

Effect of white tea consumption on serum leptin, TNF-α and UCP1 gene expression in ovariectomized rats

Obesity and dyslipidemia due to estrogen deficiency are among the important health problems in menopausal women. Increasing evidence reports the anti-obesity and anti-hyperlipidemic properties of tea polyphenols. However, the effect of white tea (WT) with high polyphenol content on overweight and lipid profile is uncertain. Here, we aimed to examine the effects of long-term WT consumption on serum leptin, tumor necrosis factor- alpha (TNF-α) and uncoupling protein 1 (UCP1) mRNA gene expression in ovariectomized (OVX) rats. Adult rats were divided into four groups (n = 8): (i) sham, (ii) OVX, (iii) WT and (iv) OVX + WT. WT was given at a dose of 0.5% w/v for 12 weeks. In the study, body weight, serum leptin, TNF, estradiol (E2) levels, lipid profile and UCP1 mRNA gene expression in brown adipose tissue (BAT) were evaluated. There was a significant increase in body weight of OVX rats, which was decreased following WT consumption. While leptin and E2 levels decreased in the OVX group, TNF levels increased. There was no difference between the NF-kB levels of the groups. In addition, BAT UCP1 mRNA expression was significantly decreased in OVX groups, while WT treatment stimulated UCP1 activity. We explain the stimulatory effect of WT on weight loss mainly by the induction of UCP1 gene-mediated thermogenesis and suppression of inflammation. Therefore, we suggest that prolonged WT consumption may have beneficial effects in limiting excess weight gain caused by estrogen deficiency.

Uncoupling Protein 2 Expression Modulates Obesity in Chronic Kidney Disease Patients.

Obesity is a multifactorial metabolic disease resulting from behavioral and genetic factors. Obesity is linked to diabetes mellitus and hypertension, which are considered as major risk factors for chronic kidney disease (CKD); moreover, it has a direct effect on developing CKD and end stage renal disease (ESRD). Here was aimed to examine the association between uncoupling protein 2 (UCP2) gene expression and obesity in CKD patients. UCP2 gene expression was analyzed by real time polymerase chain reaction (RT-PCR) in 93 participants divided into three groups. The groups included 31 non-obese CKD patients, 31 obese CKD patients, and 31 healthy, age-matched, unrelated volunteers as a control group. UCP2 gene expression was significantly relevant when comparing the non-obese CKD and obese CKD groups to the control group (p< 0.001). No significant association was found when the groups were compared by gender; Chi-square (X2) was 2.38 and p= 0.304. A significant negative correlation was found between UCP2 gene expression and BMI in CKD (p< 0.05). These results indicate that UCP2 gene expression plays a significant role as a risk factor for obesity in CKD patients.

Parathyroid hormone receptor stimulation induces human adipocyte lipolysis and browning.

Activation of brown adipose tissue is a promising strategy to treat and prevent obesity and obesity-related disorders. Activation of uncoupling protein 1 (UCP1) leads to uncoupled respiration and dissipation of stored energy as heat. Induction of UCP1-rich adipocytes in white adipose tissue, a process known as 'browning', serves as an alternative strategy to increase whole body uncoupling capacity. Here, we aim to assess the association between parathyroid hormone (PTH) receptor expression and UCP1 expression in human adipose tissues and to study PTH effects on human white and brown adipocyte lipolysis and UCP1 expression. A descriptive study of human neck adipose tissue biopsies substantiated by an interventional study on human neck-derived adipose tissue cell models. Thermogenic markers and PTH receptor gene expression are assessed in human neck adipose tissue biopsies and are related to individual health records. PTH-initiated lipolysis and thermogenic gene induction are assessed in cultured human white and brown adipocyte cell models. PTH receptor involvement is investigated by PTH receptor silencing. PTH receptor gene expression correlates with UCP1 gene expression in the deep-neck adipose tissue in humans. In cell models, PTH receptor stimulation increases lipolysis and stimulates gene transcription of multiple thermogenic markers. Silencing of the PTH receptor attenuates the effects of PTH indicating a direct PTH effect via this receptor. PTH 1 receptor stimulation by PTH may play a role in human adipose tissue metabolism by affecting lipolysis and thermogenic capacity.

In vivo emergence of beige-like fat in chickens as physiological adaptation to cold environments

While it has been hypothesized that brown adipocytes responsible for mammalian thermogenesis are absent in birds, the existence of beige fat has yet to be studied directly. The present study tests the hypothesis that beige fat emerges in birds as a mechanism of physiological adaptation to cold environments. Subcutaneous neck adipose tissue from cold-acclimated or triiodothyronine (T3)-treated chickens exhibited increases in the expression of avian uncoupling protein (avUCP, an ortholog of mammalian UCP2 and UCP3) gene and some known mammalian beige adipocyte-specific markers. Morphological characteristics of white adipose tissues of treated chickens showed increased numbers of both small and larger clusters of multilocular fat cells within the tissues. Increases in protein levels of avUCP and mitochondrial marker protein, voltage-dependent anion channel, and immunohistochemical analysis for subcutaneous neck fat revealed the presence of potentially thermogenic mitochondria-rich cells. This is the first evidence that the capacity for thermogenesis may be acquired by differentiating adipose tissue into beige-like fat for maintaining temperature homeostasis in the subcutaneous fat ‘neck warmer’ in chickens exposed to a cold environment.

The association between Uncoupling proteins (UCP2) gene expression and obesity.

The association between Uncoupling proteins (UCP2) gene expression and obesity.

Reproductive toxicity of iron oxide nanoparticles, silver nanoparticles and their mixture in male rats: Effects on testicular gene expression

Iron oxide nanoparticles (Fe2O3NPs) have shown wide biological applications in magnetic resonance imaging (MRI), drug delivery, gene therapy, cancer treatments, in vitro diagnostics (IVD), and vaccine and antibody production. Although Fe2O3NPs have a variety of applications, few studies have demonstrated that exposure to Fe2O3NPs may lead to adverse effects, such as reproductive toxicity. Silver nanoparticles (AgNPs) are widely used in products across industries; they are often used for their antimicrobial activity in medicine and are also often found in detergents. Few studies have demonstrated that exposure to AgNPs may lead to adverse effects, such as reproductive toxicity. There is no enough results on the reproductive toxicity induced by Fe2O3NPs and AgNPs, especially in combination. Therefore, the present study aimed to investigate the reproductive toxicity of iron oxide nanoparticles, silver nanoparticles and their combination in male rats. In the present study Wistar male rats were used. Animals were divided into 4 equal groups, 10 rats each. Group 1 served as control, group 2 was administered orally with Fe2O3NPs (5 mg/kg BW; >50 nm), group 3 was treated intraperitoneally with AgNPs (50 mg/kg BW; >100 nm) and group 4 was administered with the mixture of Fe2O3NPs with AgNPs. Animals were treated with doses every day for 79 days. Treatment with Fe2O3NPs, AgNPs and their combination caused significant (P < 0.05) changed in gene expression of mitochondrial transcription factor-A (mtTFA) and uncoupling protein 2 (UCP 2) in testes compared to control group.

β-hydroxy-β-methylbutyrate supplementation benefits the effects of resistance training on body fat reduction via increased irisin expression in white adipose tissue.

The effects of resistance training (RT) associated with calcium β-hydroxyβ-methylbutyrate (CaHMB) supplementation on the body composition and gene expression of cytokines related to skeletal muscle hypertrophy and adipose tissue metabolism were studied in rats. Male Wistar rats were divided into four groups of 12 animals: sedentary control (SC); sedentary supplemented (SS); resistance training control (RTC) and resistance training supplemented (RTS). Rats from RTC and RTS groups were submitted to an RT programme and those from SS and RTS groups received 1 mL of CaHMB (320 mg kg-1 day-1) by gavage, for 8 weeks. We evaluated: body composition; plasma lipid profile; the gene expression of interleukin (IL)-6, IL-10, IL-15 and fibronectin type III domain-containing protein 5 (FNDC-5) in skeletal muscle, and IL-6, mitochondrial uncoupling protein 1 (UCP-1) in white adipose tissue (WAT); and the concentration of irisin in WAT. Compared to RTC alone, the combination of CaHMB with RT (RTS) further reduced abdominal circumference (5.3%), Lee index (2.4%), fat percentage (24.4%), plasma VLDL cholesterol (16.8%) and triglycerides (17%) and increased the gene expression of FNDC-5 (78.9%) and IL-6 (47.4%) in skeletal muscle and irisin concentration (26.9%) in WAT. Neither RT nor CaHMB affected the protein percentage or the gene expression of IL-6 and UCP-1 in WAT and IL-10, IL-15 in skeletal muscle. In conclusion, CaHMB supplementation increased the beneficial effects of RT on body fat reduction and was associated with muscular genic expression of IL-6 and FNDC-5 and irisin concentration in WAT, despite the lack of change in protein mass and maximal strength.