Levels In White Adipose Tissue Research Articles

Role of Spexin in White Adipose Tissue Thermogenesis under Basal and Cold-Stimulated Conditions.

Spexin (SPX) is a novel adipokine that plays an emerging role in metabolic diseases due to its involvement in carbohydrate homeostasis, weight loss, appetite control, and gastrointestinal movement, among others. In obese patients, SPX plasma levels are reduced. Little is known about the relationship between SPX and white adipose tissue (WAT) thermogenesis. Therefore, the aim of the present study was to evaluate the role of SPX in this process. C57BL/6J male mice were treated or not with SPX for ten days. On day 3, mice were randomly divided into two groups: one kept at room temperature and the other kept at cold temperature (4 °C). Caloric intake and body weight were recorded daily. At the end of the protocol, plasma, abdominal (epididymal), subcutaneous (inguinal), and brown AT (EAT, IAT, and BAT, respectively) depots were collected for measurements. We found that SPX treatment reduced Uncoupling protein 1 levels in WAT under both basal and cold conditions. SPX also reduced cox8b and pgc1α mRNA levels and mitochondrial DNA, principally in IAT. SPX did not modulate the number of beige precursors. SPX decreased spx levels in IAT depots and galr2 in WAT depots. No differences were observed in the BAT depots. In conclusion, we showed, for the first time, that SPX treatment in vivo reduced the thermogenic process in subcutaneous and abdominal AT, being more evident under cold stimulation.

Increased cholesterol uptake is associated with the altered gene expression in white adipose tissue of ApoE−/− mice fed a high-fat high-cholesterol diet

Apolipoprotein E knock out (ApoE−/−) mice, the widely used model for atherosclerosis, exhibits anti-obesity characteristics due to the impaired lipoprotein internalization. Since excessive accumulation of triglycerides and cholesterol in white adipose tissue (WAT) is shown to increase the risk of metabolic diseases, we investigated the effects of dietary high-fat high-cholesterol (HFHC) on gene expression profile and the possible role of cholesterol accumulation in WAT of ApoE−/− mice. Control (CON) and HFHC diets were provided to wild-type mice (WC, WH) and ApoE−/− mice (EC, EH) for 10 weeks. Although body and WAT weights were lower in the ApoE−/− group compared to the wild-type group, increases in cholesterol and lipid peroxides in WAT were only observed in the ApoE−/− group. Transcriptome analysis revealed 3660 and 839 differentially expressed genes (DEGs) in the EC/WC and EH/WH comparison, respectively. “Thermogenesis” and “Oxidative phosphorylation” KEGG pathways were found in the EC/WC comparison, but not in the EH/WH comparison. We identified 142 and 2585 DEGs in the WH/WC and EH/EC comparison respectively, indicating a stronger effect of HFHC on WAT of ApoE−/− mice. Gene ontology analysis of DEGs revealed the association of DEGs with “Regulation of inflammatory response” term, in the EH/EC comparison, but not in the WH/WC comparison. Especially, genes encoding scavenger receptors and toll-like receptors were associated with cholesterol and lipid peroxide levels in WAT of ApoE−/− mice, but not in wild-type mice. In conclusion, changes in gene expression profile of WAT were more pronounced in ApoE−/− mice compared to wild-type mice in response to HFHC, and these altered genes were related to inflammatory response. These data suggest that increased cholesterol accumulation in WAT by dietary HFHC may play a pivotal role in the regulation of gene expression in ApoE−/− mice.

Dietary progesterone contributes to intra-tissue levels of progesterone in male mice.

Progesterone serum levels have been identified as a potential predictor for treatment effect in men with advanced prostate cancer, which is an androgen-driven disease. Although progesterone is the most abundant sex steroid in orchiectomized (ORX) male mice, the origins of progesterone in males are unclear. To determine the origins of progesterone and androgens, we first determined the effect of ORX, adrenalectomy (ADX), or both (ORX+ADX) on progesterone levels in multiple male mouse tissues. As expected, intra-tissue androgen levels were mainly testicular-derived. Interestingly, progesterone levels remained high after ORX and ORX+ADX with the highest levels in white adipose tissue (WAT) and in the gastrointestinal tract. High progesterone levels were observed in mouse chow and exceptionally high progesterone levels were observed in food items such as dairy, eggs, and beef, all derived from female animals of reproductive age. To determine if orally ingested progesterone contributes to tissue levels of progesterone in males, we treated ORX+ADX and sham mice with isotope labeled progesterone or vehicle by oral gavage. We observed a significant uptake of labeled progesterone in WAT and prostate, suggesting that dietary progesterone may contribute to tissue levels of progesterone. In conclusion, although adrenal-derived progesterone contributes to intra-tissue progesterone levels in males, non-adrenal progesterone sources also contribute. We propose that dietary progesterone is absorbed and contributes to intra-tissue progesterone levels in male mice. We speculate that food with high progesterone content could be a significant source of progesterone in males, possibly with consequences for men undergoing androgen deprivation therapy for prostate cancer.

309-OR: Adipose RNA N6-Methyladenosine (m6A) Modification Promotes Obesity and Insulin Resistance through Suppressing Lipolysis

Excessive white adipose tissue (WAT) promotes insulin resistance and nonalcoholic fatty liver disease (NAFLD) in obesity; however, the WAT expansion mechanism remains poorly understood. We reported that WAT lipolysis is suppressed in obesity, likely contributing to WAT growth. Adipose triglyceride lipase (Atgl) catalyzes the lipolysis reaction, and its lipolytic activity is increased by phosphorylation and binding to cofactor Cgi58. The sympathetic nervous system activates adipocyte β adrenergic receptor (Adrb)/cAMP/PKA pathway to stimulate lipolysis via Atgl and Cgi58. In this study, we have identified a novel m6A modification of Adrb, Atgl, and Cgi58 transcripts that promotes obesity and metabolic disorders. We found that obesity was associated with increased expression of adipose Mettl3 and Mettl14 and elevated m6A levels in WAT. Mettl14 directly binds to Mettl3 to form a methyltransferase complex that catalyzes m6A on RNA. Insulin also increased Mettl14 expression and m6A levels in adipocytes. We generated adipocyte-specific Mettl14 knockout mice (Mettl14 Δfat) and placed mice on a high fat diet (HFD). Remarkably, Mettl14 Δfat mice, both males and females, were resistant to HFD-induced obesity, insulin resistance, and NAFLD. Adipose Adrb2/3, Atgl, and Cgi58 protein levels were significantly upregulated in Mettl14 Δfat mice and consequently, adipose β adrenergic signaling and lipolysis were significantly higher in Mettl14 Δfat than in Mettl14f/f mice. Mettl14 deficiency dramatically decreased the m6A content of Adrb2/3, Atgl, and Cgi58 transcripts in WAT; strikingly, m6A inhibition markedly increased translational rates of these transcripts in adipocytes. Collectively, these results unravel a previously unrecognized adipose Mettl14/m6A/translation axis that promotes obesity, insulin resistance, and NAFLD by suppressing adipose β adrenergic signaling, lipolysis, and fatty acid oxidation. Disclosure Q.Kang: None. L.Rui: None. D.Ren: None. Funding National Institutes of Health (R01DK130111)

246-LB: Stimulation of Hepatic Lipid Secretion by Glucocorticoid Action in the Nucleus of the Solitary Tract

Dysregulated lipid metabolism is a characteristic of diabetes, insulin resistance, and obesity. Increased glucocorticoid (GC) levels and/or action is associated with elevated levels of circulating triglyceride (TG)-rich very low-density lipoproteins (VLDL-TGs). Lipid metabolism is heavily affected by GCs via its direct actions on peripheral organs, e.g. liver, adipose tissue. However, how GCs modulate hepatic VLDL-TG secretion via their actions in the brain is less known. The nucleus of the solitary tract (NTS) in the hindbrain is responsive to various hormones and is an important region involved in whole-body metabolism. Here, we aimed to assess how GC action in the NTS affects hepatic TG secretion and hypothesized that GC receptor (GR) agonism in the NTS stimulates hepatic TG secretion. Sprague-Dawley rats underwent stereotaxic NTS bilateral cannulation and vascular catheterizations to enable simultaneous direct NTS infusions, intravenous injections, and blood sampling. Hepatic TG secretion rates were measured in 10h-fasted rats after intravenous poloxamer injection with concurrent NTS infusions. NTS GC infusion stimulated TG secretion compared to NTS vehicle controls, but this effect was negated with pharmacological and genetic GR antagonism, suggesting that NTS GCs are mediated via its receptor. The NTS GC-induced increase in VLDL-TG was not associated with changes in liver lipogenic gene expression and protein levels or plasma ApoB48/100. However, plasma FFAs were increased in NTS GC infused rats, and this was associated with increased pHSL:HSL protein levels in white adipose tissue. We herein provide evidence that acute GC action in the NTS stimulates hepatic VLDL-TG secretion and affects adipose tissue lipid metabolism. Increased circulating FFA availability may contribute to the hyperlipidemic effects of NTS GCs. Future studies to assess the role of NTS GC action in diabetic and obesity-related metabolic disease dyslipidemic models are warranted. Disclosure B. Vasilev: None. M. S. Grewal: None. B. Lum: None. J. T. Yue: None. Funding Natural Sciences and Engineering Research Council of Canada (RGPIN-2016-06657); Canada Foundation for Innovation (37267); Canada Research Chairs Tier 2 in Brain Regulation of Metabolism

Green tea extract exhibits antidiabetic effects partly through regulating dipeptidyl peptidase-4 expression in adipose tissue

The antidiabetic effects of green tea have been demonstrated in clinical trials and epidemiological studies. This study investigated the antidiabetic effects of green tea extract (GTE) and its underlying molecular mechanisms using a leptin receptor-deficient db/db mouse model (Leprdb/db). Treatment with GTE for 2 weeks improved glucose tolerance and insulin sensitivity in Leprdb/db mice. In addition, GTE treatment reduced the body weight and adiposity of Leprdb/db mice. Furthermore, GTE treatment reduced pro-inflammatory gene expression, including nuclear factor kappa B (NF-κB) in white adipose tissue (WAT), and also reduced dipeptidyl peptidase-4 (DPP4) expression levels in WAT as well as in the serum. The promoter region of Dpp4 contains the NF-κB binding site, and DPP4 was found to be a direct target of NF-κB. Consistently, in vitro treatment of cells with GTE or its main constituent epigallocatechin gallate reduced lipopolysaccharide-induced NF-κB/DPP4 expression in 3T3-L1 adipocytes and RAW264.7 cells. Overall, our data demonstrated that GTE exerts an anti-diabetic effect by regulating the expression levels of NF-κB and DPP4 in WAT.

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

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

Long-term exposure to environmental levels of phenanthrene induces emaciation-thirst disease-like syndromes in female mice

Phenanthrene (Phe) is a polycyclic aromatic hydrocarbon widely present in foods and drinking water. To explore the detrimental effects of Phe on body metabolism, female Kunming mice were treated with Phe in drinking water at concentrations of 0.05, 0.5 and 5 ng/mL. After exposure for 270 d, the animals exhibited dose-dependent reduced body weight and increased water consumption. The dose-dependent accumulation of Phe in the brain decreased hypothalamic neuron numbers, upregulated hypothalamic expression of anaplastic lymphoma kinase, elevated norepinephrine levels in white adipose tissue (WAT) and further activated lipolysis in WAT, leading to a reduction in fat mass. Brown adipose tissue formation was reduced, accompanied by the inhibition of the bone morphogenetic protein signaling pathway. A simultaneous reduced serum levels of antidiuretic hormone (arginine vasopressin) might be one of the reasons for increased water consumption. The present results indicate an environmental etiology and prevention way for the development of emaciation-thirst disease.

208-LB: Sensory Nerve Neuropeptide Calcitonin Gene–Related Peptide (CGRP) in Adipose Tissue Changes According to Metabolic Status

White adipose tissue (WAT) is the chief energy storage site in the body and is densely innervated by sensory and sympathetic nerves that enable bi-directional neural communication with the central nervous system. The sympathetic neurotransmitter norepinephrine is the best-studied nerve product in WAT, and is known to stimulate lipolysis, browning (development of brown adipocytes in WAT) , thermogenesis, and other metabolically favorable processes. Conversely, sensory nerves in WAT secrete neuropeptides such as calcitonin gene related peptide (CGRP) , a vasodilatory neuropeptide that also impacts lipolysis, but has been vastly understudied. Circulating CGRP levels are known to be increased in obese humans, but given the beneficial metabolic effects of CGRP this may be a case of CGRP receptor resistance, similar to the observed leptin and insulin resistance with obesity. Therefore, a more comprehensive investigation into CGRP’s roles in adipose tissue and the importance of the sensory nerve supply for WAT function and insulin sensitivity is warranted. Using intravital calcium imaging in WAT of mice, we have observed activation of tissue nerves after application of lipids such as 13-HODE, which is an agonist of sensory nerves and leads to CGRP release. Thirty minutes after 13-HODE administration to WAT there was a significant increase in CGRP levels in WAT (by tissue ELISA) , which were reduced at 120min post-treatment. This suggests local lipid levels in WAT may trigger release of this sensory neuropeptide as an interoceptive response. With obesity, in both diet-induced and genetic ob/ob mice, we see increased WAT CGRP, which fits with reports in humans and may be due to chronically elevated tissue lipids. Exercise also increases tissue CGRP levels, perhaps due to an acute need for lipid fuels in this negative energy balance state. Taken together, CGRP is a novel factor in adipose that may be relevant for changing energy balance status and likely contributes to metabolic health. Disclosure G. Mishra: None. J. Willows: None.

GABA and Fermented Curcuma longa L. Extract Enriched with GABA Ameliorate Obesity through Nox4-IRE1α Sulfonation-RIDD-SIRT1 Decay Axis in High-Fat Diet-Induced Obese Mice.

Gamma-aminobutyric acid (GABA) is a natural amino acid with antioxidant activity and is often considered to have therapeutic potential against obesity. Obesity has long been linked to ROS and ER stress, but the effect of GABA on the ROS-associated ER stress axis has not been thoroughly explored. Thus, in this study, the effect of GABA and fermented Curcuma longa L. extract enriched with GABA (FCLL-GABA) on the ROS-related ER stress axis and inositol-requiring transmembrane kinase/endoribonuclease 1α (IRE1α) sulfonation were examined with the HFD model to determine the underlying anti-obesity mechanism. Here, GABA and FCLL-GABA supplementations significantly inhibited the weight gain in HFD fed mice. The GABA and FCLL-GABA supplementation lowered the expressions of adipogenic transcription factors such as PPAR-γ, C/EBPα, FAS, and SREBP-1c in white adipose tissue (WAT) and liver from HFD-fed mice. The enhanced hyper-nutrient dysmetabolism-based NADPH oxidase (Nox) 4 and the resultant IRE1α sulfonation-RIDD-SIRT1 decay under HFD conditions were controlled with GABA and FCLL-GABA. Notably, GABA and FCLL-GABA administration significantly increased AMPK and sirtuin 1 (SIRT1) levels in WAT of HFD-fed mice. These significant observations indicate that ER-localized Nox4-induced IRE1α sulfonation results in the decay of SIRT1 as a novel mechanism behind the positive implications of GABA on obesity. Moreover, the investigation lays a firm foundation for the development of FCLL-GABA as a functional ingredient.

Comprehensive Sex Steroid Profiling in Multiple Tissues Reveals Novel Insights in Sex Steroid Distribution in Male Mice.

A comprehensive atlas of sex steroid distribution in multiple tissues is currently lacking, and how circulating and tissue sex steroid levels correlate remains unknown. Here, we adapted and validated a gas chromatography tandem mass spectrometry method for simultaneous measurement of testosterone (T), dihydrotestosterone (DHT), androstenedione, progesterone (Prog), estradiol, and estrone in mouse tissues. We then mapped the sex steroid pattern in 10 different endocrine, reproductive, and major body compartment tissues and serum of gonadal intact and orchiectomized (ORX) male mice. In gonadal intact males, high levels of DHT were observed in reproductive tissues, but also in white adipose tissue (WAT). A major part of the total body reservoir of androgens (T and DHT) and Prog was found in WAT. Serum levels of androgens and Prog were strongly correlated with corresponding levels in the brain while only modestly correlated with corresponding levels in WAT. After orchiectomy, the levels of the active androgens T and DHT decreased markedly while Prog levels in male reproductive tissues increased slightly. In ORX mice, Prog was by far the most abundant sex steroid, and, again, WAT constituted the major reservoir of Prog in the body. In conclusion, we present a comprehensive atlas of tissue and serum concentrations of sex hormones in male mice, revealing novel insights in sex steroid distribution. Brain sex steroid levels are well reflected by serum levels and WAT constitutes a large reservoir of sex steroids in male mice. In addition, Prog is the most abundant sex hormone in ORX mice.

Polar fraction from Parkinsonia aculeata aerial parts extract improves imbalanced metabolic profile and reduces proinflammatory interleukin levels in white adipose tissue in obese rats induced by western diet

Ethnopharmacological relevanceParkinsonia aculeata L. (Cesalpineaceae) is a medium tree found in the Xingó region (semi-arid area) in Northeast of Brazil, recognised by local population as an antidiabetic agent. According information from local community, the commonly traditional preparation is prepared as an infusion of the aerial part of the plant and consumed over the day to manage diabetes-related complications. Previous studies have described Parkinsonia aculeate as a product with both hypoglycemic and hypotriglyceridemic effects. Aim of the studyThe objective of this study was to evaluate the effects of polar fraction obtained from the hydroethanolic extract of Parkinsonia aculeata (PfrHEPA) on the lipid profile of animals that consumed a westernized diet. Materials and methodsThirty-six Wistar rats (45–55 g) were fed either with standard control(C) or westernized diet(W) for 120 days. The food intake, body weight evolution and body size were also analyzed. From 120 to 150 days, they were orally treated according to their group with vehicle (distillated water, 10 mL/kg), PfrHEPA at three doses (35, 70 and 140 mg/kg/day) or Gemfibrozil (140 mg/kg/day) for 30 days. ResultsThe animals fed with westernized diet showed dyslipidemia when compared to animals receiving a standard diet. Treatment with PfrHEPA (140 mg/kg), even with the continued consumption of westernized diet by animals (from 120 to 150 days) promoted a significant reduction in total cholesterol, LDL and triglyceride levels, in relation to untreated W group. PfrHEPA 140 mg/kg reduced the key serum lipids and glycaemia as well as inflammatory cytokines known as important risk factors of cardiovascular diseases. ConclusionsThe observed evidence may contribute to the control of metabolic parameters as dyslipidemia corroborating the ethnopharmacological information concerning the antihyperlipidemic and hypoglycemic activities of P. aculeata.

Atractylodes chinensis Water Extract Ameliorates Obesity via Promotion of the SIRT1/AMPK Expression in High-Fat Diet-Induced Obese Mice.

Obesity remains a continuing global health concern, as it is associated with an increased risk of many chronic diseases. Atractylodes chinensis Koidz. (Ac) is traditionally used in the treatment of inflammatory diseases, such as arthritis, hepatitis, and gastric ulcers. Despite the diverse pharmacological activities of Ac, scientific evidence for the use of Ac in obesity is still limited. Therefore, the present study aimed to determine the anti-obesity effects of Ac. C57BL/6N mice were divided into five groups as follows: chow diet group (CON), 45% HFD group, HFD + oral administration of orlistat group, and HFD + oral administration of Ac groups. RT-PCR and western blotting were used to examine the expression of molecules relating to obesity progression. Ac-administered mice showed dramatically decreased body weight and weight gain compared to the high-fat diet (HFD)-fed mice. In addition, Ac administration attenuated the protein expression levels of adipogenic transcription factors in the white adipose tissue (WAT) and livers of HFD-fed mice. Furthermore, Ac administration declined the expression levels of lipogenic genes, while enhancing those of the fatty acid oxidation genes in the WAT of HFD-fed mice. Importantly, Ac administration highly upregulated the AMP-activated kinase (AMPK) and sirtuin 1 (SIRT1) expression levels in WAT of the HFD-induced obese mouse model. Our results provide evidence that Ac can effectively ameliorate weight gain and adipose tissue expansion.

MiR-21 mimic blocks obesity in mice: A novel therapeutic option

MicroRNAs (miRNAs) are promising drug targets for obesity and metabolic disorders. Recently, miRNA mimics are providing a unique mechanism of action that guides the process for drug development and sets out the context of their therapeutic application. miRNA (miR)-21 expression in white adipose tissue (WAT) has been associated with obesity. We aimed to analyze miR-21 expression levels in relation to diabetes and obesity to determine the effect that miR-21 mimic has on processes involved in WAT functionality, to dissect the underlying molecular mechanisms, and to study the potential therapeutic application of the miR-21 mimic against obesity. We found higher miR-21 levels in WAT from non-diabetic obese compared to normoweight humans and mice. Moreover, in 3T3-L1 adipocytes, miR-21 mimic affect genes involved in WAT functionality regulation and significantly increase the expression of genes involved in browning and thermogenesis. Interestingly, in vivo treatment with the miR-21 mimic blocked weight gain induced by a high-fat diet in obese mice, without modifying food intake or physical activity. This was associated with metabolic enhancement, WAT browning, and brown adipose tissue (AT) thermogenic programming through vascular endothelial growth factor A (VEGF-A), p53, and transforming growth factor β1 (TGF-β1) signaling pathways. Our findings suggest that miR-21 mimic-based therapy may provide a new opportunity to therapeutically manage obesity and consequently, its associated alterations.

Icariin Improves Lipid Metabolism via PGC1-α/FNDC5/UCP1 Pathway

Recently, more and more studies have confirmed that icariin prevent diet-induced obesity and insulin resistance to improve lipid metabolism. FNDC5/Irisin also elicit anti-obesity effects by inducing browning of white adipose tissue(WAT) stimulating uncoupling protein 1(UCP1) expression. In female FNDC5 knockout(FNDC5-KO) mice, we found that FNDC5 deficiency worsened the age-induced obesity. Therefore, The purpose of this study was to investigate the therapeutic effect and mechanism of icariin in middle-aged mice with FNDC5 knockout-induced obesity. FNDC5-KO mice were used to determine the roles of FNDC5 in lipid metabolism by qPCR, H&E and their body weights and serum cholesterol(TC), triglyceride(TG) were detected. The therapeutic efficacy of icariin on lipid metabolism were further investigated in icariin-treated mice aged 50-52weeks. FNDC5-KO reduced the browning of WAT and worsened the age-induced fat accumulation and weight gain only in female mice. Icariin ruduced body weight and increased FNDC5, PGC1-α, and UCP1 expression levels in WAT, suggesting that icariin improves lipid metabolism via the PGC1-α/FNDC5/UCP1 pathway, but the effect was blocked by FNDC5-KO only in female. Taken together, icariin effectively reduce body weight and adipose content by promoting the browning of WAT via the PGC1-α/FNDC5/UCP1 pathway. FNDC5 is essential for the effect of icariin only in female mice, indicating the sex differences of icariin are accounted for the differences on FNDC5. Funding: This study was funded by the project of the Natural Science Foundation of Guangdong Province (2018A030313632); the project of the Traditional Chinese Medicine Bureau of Guangdong Province (20211118) to Fuping Ding. Declaration of Interest: None to declare. Ethical Approval: All experimental procedures were performed in accordance with the Guidelines of Animal Experiments from the Committee of Medical Ethics, National Health Department of China. Animal experiments were approved by the Animal Research Center of Guangzhou University of Chinese Medicine. All efforts were made to reduce animal discomfort and the number of animals used.

Genetic Ablation of Transmembrane Prolyl 4-Hydroxylase Reduces Atherosclerotic Plaques in Mice.

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Adipose tissue lipolysis is regulated by PAQR11 via altering protein stability of phosphodiesterase 4D

Fat storage and mobilization in adipose tissue play a central role in energy metabolism and are directly linked to the development of obesity. Upon starvation, fat is mobilized from adipose tissue by lipolysis, a process by which triglycerides are hydrolyzed to free fatty acids to be used as an energy source in skeletal muscles and other tissues. However, how lipolysis is activated by starvation is not fully known. In this study, we demonstrate that PAQR11, a member of the progesterone and AdipoQ receptor family, regulates starvation-mediated lipolysis. Paqr11-deleted mice are resistant to high-fat diet-induced obesity. Paqr11 deletion promotes lipolysis in white adipose tissue, characterized by increased phosphorylations of hormone-sensitive lipase (HSL) and perilipin 1 (PLIN1) and elevated serum levels of glycerol and free fatty acids. PKA activity and cAMP levels in white adipose tissue are also increased by Paqr11 deletion, accompanied by accelerated protein degradation of phosphodiesterase 4D (PDE4D). Mechanistically, PAQR11 decreases the interaction of PDE4D with SKP1-CUL1-FBXO2 E3 ligase complex, thus modulating the polyubiquitination/degradation of PDE4D. Fasting decreases the expression of the Paqr11 gene, and starvation-induced lipolysis in white adipose tissue is enhanced by Paqr11 deletion, while insulin-mediated suppression of lipolysis is not affected. Collectively, these results reveal that PAQR11 regulates lipolysis of adipose tissue and affects high-fat diet-induced obesity.

High Fiber Diets Enhance Gene Expression and Il-10 Level on Hyperlipidemic Rats Model

Hyperlipidemia induces inflammation by increasing proinflammatory cytokines and reducing anti-inflammatory cytokines. Short chain fatty acids from fiber fermented by intestinal bacteria can reduce inflammation. The aim of this study is to evaluate the benefits of high fiber diet on IL-10 gene expression and IL-10 levels in white adipose tissue in rats with high fat and fructose diet. Twenty-five male Wistar rats, were divided into 5 groups: 1) normal (N); 2) Hyperlipidemia (HL); 3) Hyperlipidemia with fiber 1.04 g/rat/day (HL1); 4) Hyperlipidemia with fiber 2.07 g/rat/day (HL2), and 5) Hyperlipidemia with fiber 3.11 g/rat/day (HL3). The rats were considered hyperlipidemia, if their plasma triglyceride levels were > 70.79 mg/dL. High fat and fructose diet contain high fructose and trans-fat, while intervention diet for T1, T2, and T3 contain a total fiber of 6.88%, 13.77% and 20.65%, respectively. Serum IL-10 analysis using ELISA method was done before and after intervention, and IL-10 gene expression was analyzed using qPCR method after intervention. High trans-fat and fructose diet decrease IL-10 levels, while high-fiber diet can significantly increase the gene expression and levels of IL-10 in hyperlipidemia rats (p<0.05). High-fiber diet can improve inflammation through increase the gene expression and levels of IL-10.

Metabolic benefits of annatto-extracted tocotrienol on glucose homeostasis, inflammation, and gut microbiome

Emerging evidence suggests that the gut microbiome plays an important role in the pathophysiology of both obesity and type 2 diabetes mellitus. We previously reported that dietary annatto-extracted tocotrienol exerts beneficial effects by modulating inflammatory responses in mice fed a high-fat diet (HFD). The purpose of this study was to test the hypothesis that tocotrienol supplementation when combined with an HFD would result in an altered gut microbiota composition. For 14 weeks, forty-eight male C57BL/6J mice were assigned to 4 groups—low-fat diet, HFD, HFD supplemented with annatto-extracted tocotrienol at 800 mg/kg diet (AT), and HFD supplemented with metformin at 200 mg/kg diet. Glucose homeostasis was assessed by glucose and insulin tolerance tests, serum and pancreas insulin levels, and histological assessments of insulin and glucagon in pancreatic tissue. The concentrations of adipokines were measured in white adipose tissues. For the gut microbiome analysis, cecal content was collected, DNA was extracted, and 16S rRNA gene sequencing was performed. AT supplementation improved glucose homeostasis and lowered resistin, leptin, and interleukin-6 levels in white adipose tissue. Relative to the HFD group, AT-supplemented mice showed a decrease in the Firmicutes to Bacteroidetes ratio and had a lower abundance of Ruminococcus lactaris, Dorea longicatena, and Lachnospiraceae family. The relative abundance of Akkermansia muciniphila was increased in the AT group compared to the low-fat diet group. The association between the metabolic improvements and the identified bacterial taxa suggests a potential metabolic modulation caused by AT supplementation through the gut microbiota composition in mice fed an HFD.

Selenoprotein S regulates adipogenesis through IRE1α-XBP1 pathway.

The induction of endoplasmic reticulum (ER) stress is associated with adipogenesis, during which the inositol-requiring enzyme 1 alpha (IRE1α)-X-box-binding protein 1 (XBP1) pathway is involved. Selenoprotein S (SelS), which is an ER resident selenoprotein, is involved in ER homeostasis regulation; however, little is known about the role of SelS in regulating adipogenesis. In vivo studies showed that SelS protein levels in white adipose tissue were increased in obese subjects and high-fat diet (HFD)-fed mice. Moreover, we identified that SelS protein levels increased in the early phase of adipogenesis and then decreased in the late phase during adipogenesis. Overexpression of SelS promoted adipogenesis. Conversely, knockdown (KD) of SelS resulted in the inhibition of adipogenesis, which was related to increasing cell death, decreased mitotic clonal expansion, and cell cycle G1 arrest. In vivo studies also showed that ER stress markers (p-IRE1α/IRE1α, XBP1s, and Grp78) were significantly increased with upregulating of SelS expression in subcutaneous and visceral adipose tissues in the obese subjects and HFD-fed mice. Furthermore, in SelS KD cells, the levels of Grp78 were increased and the levels of p-IRE1α/IRE1α were unchanged , but mRNA levels of spliced XBP1 (XBP1s) produced by IRE1α-mediated splicing were decreased, suggesting a role of SelS in the modulation of IRE1α-XBP1 pathway. Moreover, inhibition of adipogenesis by SelS suppression can be rescued by overexpression of XBP1s. Thus, SelS appears to function as a novel regulator of adipogenesis through the IRE1α-XBP1 signaling pathway.