Effect of Oleuropein on Anti-Obesity and Uncoupling Protein 1 Level in Brown Adipose Tissue in Mild Treadmill Walking Rats with Diet-Induced Obesity.

Oleuropein aglycone (OA), which is the absorbed form of oleuropein, is a major phenolic compound in extra virgin olive oil. We analyzed the anti-obesity effect of OA intake combined with mild treadmill walking (MTW, 4 m/min for 20 min/d, 5-6 d/wk, without electric shocks and slope) in rats under a high-fat diet (HF). Four-week-old male Sprague-Dawley rats (n=28) were equally divided into four groups: control (HF), 0.08% oleuropein-supplemented HF (HFO), HF with MTW (HF+W), and HFO with MTW (HFO+W) groups. After 28 d, the inguinal subcutaneous fat content and weight gain were significantly lower in the HFO+W group than in the control group. The HFO+W group also had significantly higher levels of urinary noradrenaline secretion, interscapular brown adipose tissue, uncoupling protein 1, brain transient receptor potential ankyrin subtype 1 (TRPA1), vanilloid subtype 1 (TRPV1), and brain-derived neurotrophic factor (BDNF) than the control group. Especially, the HFO+W group showed a synergistic effect on noradrenaline secretion. Therefore, OA combined with MTW may accelerate the enhancement of UCP1 and BDNF levels in rats with HF-induced obesity by increasing noradrenaline secretion after TRPA1 and TRPV1 activation.

A modified system using macrophage-conditioned medium revealed that the indirect effects of anti-inflammatory food-derived compounds improve inflammation-induced suppression of UCP-1 mRNA expression in 10T1/2 adipocytes.

Recently, it has been suggested that brown and beige adipocytes may ameliorate obesity because these adipocytes express uncoupling protein-1 (UCP-1), which generates heat by consuming lipid. However, obesity-induced inflammation suppresses the expression of UCP-1. To improve such conditions, food components with anti-inflammatory properties are attracting attention. In this study, we developed a modified system to evaluate only the indirect effects of anti-inflammatory food-derived compounds by optimizing the conventional experimental system using conditioned medium. We validated this new system using 6-shogaol and 6-gingerol, which have been reported to show the anti-inflammatory effects and to increase the basal expression of UCP-1 mRNA. In addition, we found that the acetone extract of Sarcodon aspratus, an edible mushroom, showed anti-inflammatory effects and rescued the inflammation-induced suppression of UCP-1 mRNA expression. These findings indicate that the system with conditioned medium is valuable for evaluation of food-derived compounds with anti-inflammatory effects on the inflammation-induced thermogenic adipocyte dysfunction.

Metabolome analysis reveals that cyclic adenosine diphosphate ribose contributes to the regulation of differentiation in mice adipocyte.

Adipocytes play a key role in energy storage and homeostasis. Although the role of transcription factors in adipocyte differentiation is known, the effect of endogenous metabolites of low molecular weight remains unclear. Here, we analyzed time-dependent changes in the levels of these metabolites throughout adipocyte differentiation, using metabolome analysis, and demonstrated that there is a positive correlation between cyclic adenosine diphosphate ribose (cADPR) and Pparγ mRNA expression used as a marker of differentiation. We also found that the treatment of C3H10T1/2 adipocytes with cADPR increased the mRNA expression of those marker genes and the accumulation of triglycerides. Furthermore, inhibition of ryanodine receptors (RyR), which are activated by cADPR, caused a significant reduction in mRNA expression levels of the marker genes and triglyceride accumulation in adipocytes. Our findings show that cADPR accelerates adipocytic differentiation via RyR pathway.

Inflammation-induced nitric oxide suppresses PPARα expression and function via downregulation of Sp1 transcriptional activity in adipocytes.

The activation of peroxisome proliferator-activated receptor alpha (PPARα), a ligand-dependent transcription factor that regulates lipid oxidation-related genes, has been employed to treat hyperlipidemia. Emerging evidence indicates that Ppara gene expression decreases in adipose tissue under obese conditions; however, the underlying molecular mechanisms remain elusive. Here, we demonstrate that nitric oxide (NO) suppresses Ppara expression by regulating its promoter activity via suppression of specificity protein 1 (Sp1) transcriptional activity in adipocytes. NO derived from lipopolysaccharide (LPS) -activated macrophages or a NO donor (NOR5) treatment, suppressed Ppara mRNA expression in 10T1/2 adipocytes. In addition, Ppara transcript levels were reduced in the white adipose tissue (WAT) in both acute and chronic inflammation mouse models; however, such suppressive effects were attenuated via a nitric oxide synthase 2 (NOS2) inhibitor. Endoplasmic reticulum (ER) stress inhibitors attenuated the NO-induced repressive effects on Ppara gene expression in 10T1/2 adipocytes. Promoter mutagenesis and chromatin immunoprecipitation assays revealed that NO decreased the Sp1 occupancy in the proximal promoter regions of the Ppara gene, which might partially result from the reduced Sp1 expression levels by NO. This study delineated the molecular mechanism that modulates Ppara gene transcription upon NO stimulation in white adipocytes, suggesting a possible mechanism for the transcriptional downregulation of Ppara in WAT under obese conditions.

8-Prenyl daidzein and 8-prenyl genistein from germinated soybean modulate inflammatory response in activated macrophages.

Soy isoflavones have been shown to have anti-inflammatory properties; however, the anti-inflammatory effects of isoflavone metabolites produced during soybean germination remain unclear. We found that the daidzein and genistein derivatives, 8-prenyl daidzein (8-PD) and 8-prenyl genistein (8-PG), demonstrated a more potent effect than daidzein and genistein on repressing inflammatory responses in macrophages. Although IkB protein levels were unaltered, 8-PD and 8-PG repressed nuclear factor kappa B (NF-κB) activation, which was associated with reduced ERK1/2, JNK, and p38 MAPK activation and suppressed mitogen- and stress-activated kinase 1 phosphorylation. Inflammatory responses induced by the medium containing hypertrophic adipocyte secretions were successfully suppressed by 8-PD and 8-PG treatment. In the ex vivo study, 8-PD and 8-PG significantly inhibited proinflammatory C-C motif chemokine ligand 2 (CCL2) secretion from the adipose tissues of mice fed a long-term high-fat diet. The data suggest that 8-PD and 8-PG could regulate macrophage activation under obesity conditions.

Mevalonate biosynthesis pathway regulates the development and survival of brown adipocytes.

The high thermogenic activity of brown adipose tissue (BAT) has received considerable attention. Here, we demonstrated the role of the mevalonate (MVA) biosynthesis pathway in the regulation of brown adipocyte development and survival. The inhibition of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), the rate-limiting enzyme in the MVA pathway and the molecular target of statins, suppressed brown adipocyte differentiation by suppressing protein geranylgeranylation-mediated mitotic clonal expansion. The development of BAT in neonatal mice exposed to statins during the fetal period was severely impaired. Moreover, statin-induced geranylgeranyl pyrophosphate (GGPP) deficiency led to the apoptosis of mature brown adipocytes. Brown adipocyte-specific Hmgcr knockout induced BAT atrophy and disrupted thermogenesis. Importantly, both genetic and pharmacological inhibition of HMGCR in adult mice induced morphological changes in BAT accompanied by an increase in apoptosis, and statin-treated diabetic mice showed worsened hyperglycemia. These findings revealed that MVA pathway-generated GGPP is indispensable for BAT development and survival.

Combined treatment with teneligliptin and canagliflozin additively suppresses high-fat diet-induced body weight gain in mice with modulation of lipid metabolism-related gene expression.

In the treatment of type 2 diabetes mellitus (T2DM), comprehensive management of multiple risk factors, such as blood glucose, body weight, and lipids, is important to prevent disease progression. Although the combination of dipeptidyl peptidase-4 (DPP-4) inhibitor and sodium-glucose co-transporter 2 (SGLT2) inhibitor is often used clinically, the effects of this combination, other than glucose metabolism, have yet to be thoroughly investigated. In this study, we evaluated the effects of combined treatment with a DPP-4 inhibitor, teneligliptin, and an SGLT2 inhibitor, canagliflozin, on the body weight and lipid metabolism in high-fat diet (HFD)-induced obese mice. We found that monotherapy with teneligliptin or canagliflozin showed suppressive effects on high-fat diet-induced body weight gain and reduced inguinal white adipose tissue (iWAT) mass, and combined treatment additively reduced body weight gain and iWAT mass. Teneligliptin significantly increased oxygen consumption during the light phase, and this effect was preserved in the combined treatment. The combined treatment did not alter the mRNA expression levels of thermogenesis-related genes in adipose tissue but showed the tendency to additively induce mRNA of fatty acid oxidation-related genes in brown adipose tissue and tended to additively decrease mRNA of fatty acid synthesis-related genes in iWAT and liver tissues. These results suggest that combined treatment with teneligliptin and canagliflozin additively suppresses HFD-induced body weight gain with increasing oxygen consumption and modulating the expression of lipid metabolism-related genes. This combination therapy may provide effective body weight management for patients with T2DM and obesity.

Methylglyoxal induces multiple serine phosphorylation in insulin receptor substrate 1 via the TAK1-p38-mTORC1 signaling axis in adipocytes.

Certain metabolic intermediates produced during metabolism are known to regulate a wide range of cellular processes. Methylglyoxal (MG), a natural metabolite derived from glycolysis, has been shown to negatively influence systemic metabolism by inducing glucose intolerance, insulin resistance, and diabetic complications. MG plays a functional role as a signaling molecule that initiates signal transduction. However, the specific relationship between MG-induced activation of signal transduction and its negative effects on metabolism remains unclear. Here, we found that MG activated mammalian target of rapamycin complex 1 (mTORC1) signaling via p38 mitogen-activated protein kinase in adipocytes, and that the transforming growth factor-ß-activated kinase 1 (TAK1) is needed to activate p38-mTORC1 signaling following treatment with MG. We also found that MG increased the phosphorylation levels of serine residues in insulin receptor substrate (IRS)-1, which is involved in its negative regulation, thereby attenuating insulin-stimulated tyrosine phosphorylation in IRS-1. The negative effect of MG on insulin-stimulated IRS-1 tyrosine phosphorylation was exerted due to the MG-induced activation of the TAK1-p38-mTORC1 signaling axis. The involvement of the TAK1-p38-mTORC1 signaling axis in the induction of IRS-1 multiple serine phosphorylation was not unique to MG, as the proinflammatory cytokine, tumor necrosis factor-α, also activated the same signaling axis. Therefore, our findings suggest that MG-induced activation of the TAK1-p38-mTORC1 signaling axis caused multiple serine phosphorylation on IRS-1, potentially contributing to insulin resistance.

Metabolomics reveals inosine 5'-monophosphate is increased during mice adipocyte browning.

Adipocyte browning is one of the potential strategies for the prevention of obesity-related metabolic syndromes, but it is a complex process. Although previous studies make it increasingly clear that several transcription factors and enzymes are essential to induce browning, it is unclear what dynamic and metabolic changes occur in induction of browning. Here, we analyzed the effect of a beta-adrenergic receptor agonist (CL316243, accelerator of browning) on metabolic change in mice adipose tissue and plasma using metabolome analysis and speculated that browning is regulated partly by inosine 5'-monophosphate (IMP) metabolism. To test this hypothesis, we investigated whether Ucp-1, a functional marker of browning, mRNA expression is influenced by IMP metabolism using immortalized adipocytes. Our study showed that mycophenolic acid, an IMP dehydrogenase inhibitor, increases the mRNA expression of Ucp-1 in immortalized adipocytes. Furthermore, we performed a single administration of mycophenolate mofetil, a prodrug of mycophenolic acid, to mice and demonstrated that mycophenolate mofetil induces adipocyte browning and miniaturization of adipocyte size, leading to adipose tissue weight loss. These findings showed that IMP metabolism has a significant effect on adipocyte browning, suggesting that the regulator of IMP metabolism has the potential to prevent obesity.

Roles of phosphatidylserine and phospholipase C in the activation of TOR complex 2 signaling in Saccharomyces cerevisiae.

Target of rapamycin (TOR) forms two distinct complexes, TORC1 and TORC2, to exert its essential functions in cellular growth and homeostasis. TORC1 signaling is regulated in response to nutrients such as amino acids and glucose; however, the mechanisms underlying the activation of TORC2 signaling are still poorly understood compared to those for TORC1 signaling. In the budding yeast Saccharomyces cerevisiae, TORC2 targets the protein kinases Ypk1 and Ypk2 (hereafter Ypk1/2), and Pkc1 for phosphorylation. Plasma membrane stress is known to activate TORC2-Ypk1/2 signaling. We have previously reported that methylglyoxal (MG), a metabolite derived from glycolysis, activates TORC2-Pkc1 signaling. In this study, we found that MG activates the TORC2-Ypk1/2 and TORC2-Pkc1 signaling, and that phosphatidylserine is involved in the activation of both signaling pathways. We also demonstrated that the Rho family GTPase Cdc42 contributes to the plasma membrane stress-induced activation of TORC2-Ypk1/2 signaling. Furthermore, we revealed that phosphatidylinositol-specific phospholipase C, Plc1, contributes to the activation of both TORC2-Ypk1/2 and TORC2-Pkc1 signaling.

Integration of bioassay and non-target metabolite analysis of tomato reveals that ß-carotene and lycopene activate the adiponectin signaling pathway, including AMPK phosphorylation.

Adiponectin, an adipokine, regulates glucose metabolism and insulin sensitivity through the adiponectin receptor (AdipoR). In this study, we searched for metabolites that activate the adiponectin signaling pathway from tomato (Solanum lycopersicu). Metabolites of mature tomato were separated into 55 fractions by liquid chromatography, and then each fraction was examined using the phosphorylation assay of AMP-protein kinase (AMPK) in C2C12 myotubes and in AdipoR-knockdown cells by small interfering RNA (siRNA). Several fractions showed AMPK phosphorylation in C2C12 myotubes and siRNA-mediated abrogation of the effect. Non-targeted metabolite analysis revealed the presence of 721 diverse metabolites in tomato. By integrating the activity of fractions on AMPK phosphorylation and the 721 metabolites based on their retention times of liquid chromatography, we performed a comprehensive screen for metabolites that possess adiponectin-like activity. As the screening suggested that the active fractions contained four carotenoids, we further analyzed ß-carotene and lycopene, the major carotenoids of food. They induced AMPK phosphorylation via the AdipoR, Ca2+/calmodulin-dependent protein kinase kinase and Ca2+ influx, in addition to activating glucose uptake via AdipoR in C2C12 myotubes. All these events were characteristic adiponectin actions. These results indicated that the food-derived carotenoids, ß-carotene and lycopene, activate the adiponectin signaling pathway, including AMPK phosphorylation.

Screening of flavor compounds using Ucp1-luciferase reporter beige adipocytes identified 5-methylquinoxaline as a novel UCP1-inducing compound.

Uncoupling protein 1 (UCP1) in brown or beige adipocytes is a mitochondrial protein that is expected to enhance whole-body energy expenditure. For the high-throughput screening of UCP1 transcriptional activity regulator, we established a murine inguinal white adipose tissue-derived Ucp1-luciferase reporter preadipocyte line. Using this reporter preadipocyte line, 654 flavor compounds were screened, and a novel Ucp1 expression-inducing compound, 5-methylquinoxaline, was identified. Adipocytes treated with 5-methylquinoxaline showed increased Ucp1 mRNA expression levels and enhanced oxygen consumption. 5-Methylquinoxaline induced Ucp1 expression through peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α), and 5-methylquinoxaline-induced PGC1α activation seemed to be partially regulated by its phosphorylation or deacetylation. Thus, our Ucp1-luciferase reporter preadipocyte line is a useful tool for screening of Ucp1 inductive compounds.

Methylglyoxal attenuates isoproterenol-induced increase in uncoupling protein 1 expression through activation of JNK signaling pathway in beige adipocytes.

Methylglyoxal (MG) is a metabolite derived from glycolysis whose levels in the blood and tissues of patients with diabetes are higher than those of healthy individuals, suggesting that MG is associated with the development of diabetic complications. However, it remains unknown whether high levels of MG are a cause or consequence of diabetes. Here, we show that MG negatively affects the expression of uncoupling protein 1 (UCP1), which is involved in thermogenesis and the regulation of systemic metabolism. Decreased Ucp1 expression is associated with obesity and type 2 diabetes. We found that MG attenuated the increase in Ucp1 expression following treatment with isoproterenol in beige adipocytes. However, MG did not affect protein kinase A signaling, the core coordinator of isoproterenol-induced Ucp1 expression. Instead, MG activated c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinases. We found that JNK inhibition, but not p38, recovered isoproterenol-stimulated Ucp1 expression under MG treatment. Altogether, these results suggest an inhibitory role of MG on the thermogenic function of beige adipocytes through the JNK signaling pathway.

Metabolome analysis revealed that soybean-Aspergillus oryzae interaction induced dynamic metabolic and daidzein prenylation changes.

Several isoflavonoids are well known for their ability to act as soybean phytoalexins. However, the overall effects of the soybean-Aspergillus oryzae interaction on metabolism remain largely unknown. The aim of this study is to reveal an overview of nutritive and metabolic changes in germinated and A. oryzae-elicited soybeans. The levels of individual nutrients were measured using the ustulation, ashing, Kjeldahl, and Folch methods. The levels of individual amino acids were measured using high-performance liquid chromatography. Low-molecular-weight compounds were measured through metabolome analysis using liquid chromatography-mass spectrometry. Although the levels of individual nutrients and amino acids were strongly influenced by the germination process, the elicitation process had little effect on the change in the contents of individual nutrients and amino acids. However, after analyzing approximately 700 metabolites using metabolome analysis, we found that the levels of many of the metabolites were strongly influenced by soybean-A. oryzae interactions. In particular, the data indicate that steroid, terpenoid, phenylpropanoid, flavonoid, and fatty acid metabolism were influenced by the elicitation process. Furthermore, we demonstrated that not the germination process but the elicitation process induced daidzein prenylation, suggesting that the soybean-A. oryzae interactions produce various phytoalexins that are valuable for health promotion and/or disease prevention.

TOMATOMET: A metabolome database consists of 7118 accurate mass values detected in mature fruits of 25 tomato cultivars.

The total number of low-molecular-weight compounds in the plant kingdom, most of which are secondary metabolites, is hypothesized to be over one million, although only a limited number of plant compounds have been characterized. Untargeted analysis, especially using mass spectrometry (MS), has been useful for understanding the plant metabolome; however, due to the limited availability of authentic compounds for MS-based identification, the identities of most of the ion peaks detected by MS remain unknown. Accurate mass values of peaks obtained by high accuracy mass measurement and, if available, MS/MS fragmentation patterns provide abundant annotation for each peak. Here, we carried out an untargeted analysis of compounds in the mature fruit of 25 tomato cultivars using liquid chromatography-Orbitrap MS for accurate mass measurement, followed by manual curation to construct the metabolome database TOMATOMET (http://metabolites.in/tomato-fruits/). The database contains 7,118 peaks with accurate mass values, in which 1,577 ion peaks are annotated as members of a chemical group. Remarkably, 71% of the mass values are not found in the accurate masses detected previously in Arabidopsis thaliana, Medicago truncatula or Jatropha curcas, indicating significant chemical diversity among plant species that remains to be solved. Interestingly, substantial chemical diversity exists also among tomato cultivars, indicating that chemical profiling from distinct cultivars contributes towards understanding the metabolome, even in a single organ of a species, and can prioritize some desirable metabolic targets for further applications such as breeding.

Comparative Analysis of the Preventive Effects of Canagliflozin, a Sodium-Glucose Co-Transporter-2 Inhibitor, on Body Weight Gain Between Oral Gavage and Dietary Administration by Focusing on Fatty Acid Metabolism.

PURPOSE: Sodium-glucose co-transporter-2 (SGLT2) inhibitors have various pleiotropic effects, including body weight reduction, and therefore have the potential to be used in various applications. However, such effects have not been fully investigated; thus, non-clinical studies using animal models are needed. In animal experiments, SGLT2 inhibitors are usually administered by oral or dietary methods. However, the detailed characteristics of these dosing methods, especially to induce their pleiotropic effects, have not been reported. Therefore, we compared the preventive effects of canagliflozin, an SGLT2 inhibitor, on body weight gain following oral gavage and dietary administration methods in a mouse model of diet-induced obesity. METHODS: Canagliflozin was dosed by oral gavage or dietary administration for 9 weeks to 6-week-old C57BL/6N mice fed a high-fat diet, and parameters related to obesity were evaluated. RESULTS: The suppression of body weight gain, fat mass, and hepatic lipid content was observed following both dosing methods, whereas the effect on body weight tended to be stronger in the dietary administration group. In adipose tissue, fatty acid synthase expression was significantly decreased in the dietary administration group, and its expression was significantly correlated with fat mass. However, the expression of genes related to fatty acid oxidation was unchanged, indicating that the preventive effect on body weight gain was mediated mainly through the suppression of lipid synthesis rather than the promotion of lipid oxidation. CONCLUSION: Canagliflozin prevented body weight gain through the suppression of lipid synthesis via both dosing methods, although there were some differences in the efficacy. The findings of our study can help to identify new mechanisms of action of SGLT2 inhibitors and potential applications.

Stiffness of the extracellular matrix regulates differentiation into beige adipocytes.

Beige/brite adipocytes, which express high levels of uncoupling protein 1 (UCP1) to generate heat using stored triglycerides, are induced under specific stimuli such as cold exposure in inguinal white adipose tissue (iWAT). Although extracellular microenvironments such as extracellular matrix (ECM) stiffness are known to regulate cell behaviors, including cell differentiation into adipocytes, the effect on iWAT cells is unknown. In this study, we show that rigid ECM promotes the cell spreading of iWAT-derived preadipocytes. Furthermore, the expression of UCP1 and other thermogenic genes in iWAT cells is promoted when the cells are cultured on rigid ECM. The expression of mTOR, a kinase known to regulate the differentiation to beige adipocytes, is decreased on rigid substrates. These results suggest that ECM stiffness plays an important role in the differentiation to beige adipocytes.

Investigating Anti-Obesity Effects by Oral Administration of Aloe vera Gel Extract (AVGE): Possible Involvement in Activation of Brown Adipose Tissue (BAT).

The aim of this study is to investigate the mechanism of anti-obesity effects of Aloe vera gel extract (AVGE) containing Aloe sterols. Previously, we reported that oral intake of Aloe vera components has an anti-diabetic and anti-obesity effect. This study was designed to assess the role of brown adipose tissue (BAT) in the anti-obesity effect of AVGE. Six-week-old male mice were divided into three groups; STD (standard diet), HFD (60% high fat diet) and AVGE (60% high fat diet with AVGE treatment). During 11 wk of AVGE administration, body weight has been monitored. Tissue samples were obtained to be measured the weight and evaluated the gene expressions. Mice treated with AVGE had suppressed body weight, and liver and fat weight gain. To investigate BAT activation, we measured the expression of mRNA related to BAT thermogenesis. Mice in the AVGE group had higher expression of Ucp1, Adrb3, and Cidea in BAT compared to HFD. Next, to investigate the possibility that AVGE induced hepatic FGF21, which is an important factor for nutrient and energy homeostasis including BAT regulation, in vitro study was conducted. HepG2 cell stimulated by AVGE were highly expressed FGF21. These results suggested that BAT activation partially contributes to mechanism of anti-obesity effect of Aloe sterols in diet-induced obesity (DIO) models. However, further study is needed to determine the predominant mechanism.

Glycerol kinase stimulates uncoupling protein 1 expression by regulating fatty acid metabolism in beige adipocytes.

Browning of adipose tissue is induced by specific stimuli such as cold exposure and consists of up-regulation of thermogenesis in white adipose tissue. Recently, it has emerged as an attractive target for managing obesity in humans. Here, we performed a comprehensive analysis to identify genes associated with browning in murine adipose tissue. We focused on glycerol kinase (GYK) because its mRNA expression pattern is highly correlated with that of uncoupling protein 1 (UCP1), which regulates the thermogenic capacity of adipocytes. Cold exposure-induced Ucp1 up-regulation in inguinal white adipose tissue (iWAT) was partially abolished by Gyk knockdown (KD) in vivo Consistently, the Gyk KD inhibited Ucp1 expression induced by treatment with the ß-adrenergic receptors (ßAR) agonist isoproterenol (Iso) in vitro and resulted in impaired uncoupled respiration. Gyk KD also suppressed Iso- and adenylate cyclase activator-induced transcriptional activation and phosphorylation of the cAMP response element-binding protein (CREB). However, we did not observe these effects with a cAMP analog. Therefore Gyk KD related to Iso-induced cAMP products. In Iso-treated Gyk KD adipocytes, stearoyl-CoA desaturase 1 (SCD1) was up-regulated, and monounsaturated fatty acids such as palmitoleic acid (POA) accumulated. Moreover, a SCD1 inhibitor treatment recovered the Gyk KD-induced Ucp1 down-regulation and POA treatment down-regulated Iso-activated Ucp1 Our findings suggest that Gyk stimulates Ucp1 expression via a mechanism that partially depends on the ßAR-cAMP-CREB pathway and Gyk-mediated regulation of fatty acid metabolism.

Anti-Inflammatory and Antioxidative Properties of Isoflavones Provide Renal Protective Effects Distinct from Those of Dietary Soy Proteins against Diabetic Nephropathy.

SCOPE: Dietary soy reportedly protects from diabetic nephropathy (DN), but its active components and mechanism of action remain unknown. METHODS AND RESULTS: In this study, KKAy mice are fed three types of diet: Dietary soy isoflavones with soy protein (Soy-IP) diet, reduced isoflavones soy protein (RisoP), and oral administration of isoflavones aglycones (IsoAgc). Albuminuria and glycosuria are decreased only in the soy-IP group. The risoP group show reduced expansion of mesangial matrix and renal fibrosis, the IsoAgc group show renal anti-fibrotic and anti-inflammatory effects; however, these renal pathological changes are repressed in the soy-IP group, suggesting the distinct protective roles of soy protein or isoflavones in DN. The isoflavone genistein has a better inhibitory effect on the inflammatory response and cellular interactions in both mouse tubular cells and macrophages when exposed to high glucose and albumin (HGA). Genistein also represses HGA-induced activator protein 1 activation and reactive oxidases stress generation, accompanied by reduced NADPH oxidase (NOX) gene expression. Finally, diabetic mice show a decrease in lipid peroxidation levels in both plasma and urine, along with lower NOXs gene expression. CONCLUSION: The data elucidate the detailed mechanism by which isoflavones inhibit renal inflammation and provide a potential practical adjunct therapy to restrict DN progression.