Mitochondrial Stress Links Environmental Triggers with Pro-Inflammatory Signaling in Crohn's Disease.

Inflammatory Bowel Diseases (IBD) are a group of chronic, inflammatory disorders of the gut. The incidence and activity of IBD are determined by both genetic and environmental factors. Among these factors, polymorphisms in genes related to autophagy and the consumption of non-steroidal anti-inflammatory drugs (NSAIDs) have been consistently associated with IBD. We show that NSAIDs induce mitochondrial stress and mitophagy in intestinal epithelial cells. In an altered mitophagy context simulating that observed in IBD patients, NSAID-induced mitochondrial stress leads to the release of mitochondrial components, which act as Danger Associated Molecular Patterns with pro-inflammatory potential. Furthermore, colonic organoids from Crohn's disease patients and healthy donors show activation of the mitochondrial Unfolded Protein Response (UPRmt) upon treatment with ibuprofen. Finally, colon biopsies from Crohn's disease patients in remission or with low-to-moderate activity also show expression of genes involved in UPRmt, while patients with severe activity show no increase compared to healthy donors. Our results suggest the involvement of mitochondria in the mechanisms triggering inflammation in IBD after NSAID use. Moreover, our results highlight the clinical relevance of mitochondrial stress and activation of the UPRmt pathway in the pathophysiology of Crohn's disease.

Membrane Vesicles of Toxigenic Clostridioides difficile Affect the Metabolism of Liver HepG2 Cells.

Clostridioides difficile infection (CDI) appears to be associated with different liver diseases. C. difficile secretes membrane vesicles (MVs), which may be involved in the development of nonalcoholic fatty liver disease (NALFD) and drug-induced liver injury (DILI). In this study, we investigated the presence of C. difficile-derived MVs in patients with and without CDI, and analyzed their effects on pathways related to NAFLD and DILI in HepG2 cells. Fecal extracellular vesicles from CDI patients showed an increase of Clostridioides MVs. C. difficile-derived MVs that were internalized by HepG2 cells. Toxigenic C. difficile-derived MVs decreased mitochondrial membrane potential and increased intracellular ROS compared to non-toxigenic C. difficile-derived MVs. In addition, toxigenic C. difficile-derived MVs upregulated the expression of genes related to mitochondrial fission (FIS1 and DRP1), antioxidant status (GPX1), apoptosis (CASP3), glycolysis (HK2, PDK1, LDHA and PKM2) and ß-oxidation (CPT1A), as well as anti- and pro-inflammatory genes (IL-6 and IL-10). However, non-toxigenic C. difficile-derived MVs did not produce changes in the expression of these genes, except for CPT1A, which was also increased. In conclusion, the metabolic and mitochondrial changes produced by MVs obtained from toxigenic C. difficile present in CDI feces are common pathophysiological features observed in the NAFLD spectrum and DILI.

The Metagenomic Composition and Effects of Fecal-Microbe-Derived Extracellular Vesicles on Intestinal Permeability Depend on the Patient's Disease.

The composition and impact of fecal-microbe-derived extracellular vesicles (EVs) present in different diseases has not been analyzed. We determined the metagenomic profiling of feces and fecal-microbe-derived EVs from healthy subjects and patients with different diseases (diarrhea, morbid obesity and Crohn's disease (CD)) and the effect of these fecal EVs on the cellular permeability of Caco-2 cells. The control group presented higher proportions of Pseudomonas and Rikenellaceae_RC9_gut_group and lower proportions of Phascolarctobacterium, Veillonella and Veillonellaceae_ge in EVs when compared with the feces from which these EVs were isolated. In contrast, there were significant differences in 20 genera between the feces and EV compositions in the disease groups. Bacteroidales and Pseudomonas were increased, and Faecalibacterium, Ruminococcus, Clostridium and Subdoligranum were decreased in EVs from control patients compared with the other three groups of patients. Tyzzerella, Verrucomicrobiaceae, Candidatus_Paracaedibacter and Akkermansia were increased in EVs from the CD group compared with the morbid obesity and diarrhea groups. Fecal EVs from the morbid obesity, CD and, mainly, diarrhea induced a significant increase in the permeability of Caco-2 cells. In conclusion, the metagenomic composition of fecal-microbe-derived EVs changes depending on the disease of the patients. The modification of the permeability of Caco-2 cells produced by fecal EVs depends on the disease of the patients.

Oleic acid regulates the circadian rhythm of adipose tissue in obesity.

The effect of oleic acid (OA) on the regulation of the circadian rhythm present in human visceral (VAT) and subcutaneous (SAT) adipose tissue from patients with morbid obesity has not been analyzed yet. VAT and SAT explants from patients with morbid obesity were incubated with OA to analyze the circadian regulation of clock and other genes related to lipid metabolism (SREBP-1c, FAS, LPL and CPT1), and their association with baseline variables and the improvement of these patients after bariatric surgery. There were significant differences in amplitude and acrophase in VAT with respect to SAT. In VAT, body weight negatively correlated with BMAL1 and CRY1 amplitude, and REVERBα acrophase; body mass index (BMI) negatively correlated with REVERBα acrophase; and waist circumference negatively correlated with PER3 acrophase. In SAT, BMI negatively correlated with CLOCK amplitude, and CLOCK, REVERBα and CRY2 MESOR; and waist circumference negatively correlated with PER3 amplitude and acrophase. A greater short-term improvement of body weight, BMI and waist circumference in patients with morbid obesity after bariatric surgery was associated with a lower CRY1 and CRY2 amplitude and an earlier PER1 and PER3 acrophase in SAT. OA produced a more relevant circadian rhythm and increased the amplitude of most clock genes and lipid metabolism-related genes. OA regulated the acrophase of most clock genes in VAT and SAT, placing CLOCK/BMAL1 in antiphase with regard to the other genes. OA increased the circadian rhythmicity, although with slight differences between adipose tissues. These differences could determine its different behavior in obesity.

Morbid Obesity in Women Is Associated with an Altered Intestinal Expression of Genes Related to Cancer Risk and Immune, Defensive, and Antimicrobial Response.

BACKGROUND: Little is known about the relation between morbid obesity and duodenal transcriptomic changes. We aimed to identify intestinal genes that may be associated with the development of obesity regardless of the degree of insulin resistance (IR) of patients. MATERIAL AND METHODS: Duodenal samples were assessed by microarray in three groups of women: non-obese women and women with morbid obesity with low and high IR. RESULTS: We identified differentially expressed genes (DEGs) associated with morbid obesity, regardless of IR degree, related to digestion and lipid metabolism, defense response and inflammatory processes, maintenance of the gastrointestinal epithelium, wound healing and homeostasis, and the development of gastrointestinal cancer. However, other DEGs depended on the IR degree. We mainly found an upregulation of genes involved in the response to external organisms, hypoxia, and wound healing functions in women with morbid obesity and low IR. CONCLUSIONS: Regardless of the degree of IR, morbid obesity is associated with an altered expression of genes related to intestinal defenses, antimicrobial and immune responses, and gastrointestinal cancer. Our data also suggest a deficient duodenal immune and antimicrobial response in women with high IR.

An Isolated Dose of Extra-Virgin Olive Oil Produces a Better Postprandial Gut Hormone Response, Lipidic, and Anti-Inflammatory Profile that Sunflower Oil: Effect of Morbid Obesity.

INTRODUCTION: This study evaluates the effects of 25 mL of three types of oils [extra-virgin olive oil (EVOO), olive oil (OO), and sunflower oil (SO)] on postprandial (3 h) satiety markers and variables related to metabolic status and inflammation in non-obese patients (n = 6) and in those with morbid obesity (n = 6), before and 1 year after Roux-en-Y gastric by-pass (RYGB). METHODS AND RESULTS: After EVOO intake, serum acylated ghrelin decreases and GLP1 increases more than with OO and SO. EVOO causes a higher increase of insulin and lower postprandial hypertriglyceridemia and free fatty acid levels than with OO and SO. EVOO decreases TNFα and IL6 expression in peripheral blood mononuclear cells, with OO inducing intermediate effects and SO inducing an increase of these proinflammatory markers. These results are observed in non-obese patients and in those with morbid obesity after RYGB. However, patients with morbid obesity before RYGB show a profound alteration of this response. CONCLUSION: EVOO produces more beneficial effects than OO, which has lower amounts of minor components, and SO, which has PUFA as its main component. RYGB produces an improvement in the metabolic response to all three types of oils in patients with morbid obesity.

Oleic acid restores the rhythmicity of the disrupted circadian rhythm found in gastrointestinal explants from patients with morbid obesity.

BACKGROUND & AIMS: We investigated whether oleic acid (OA), one of the main components of the Mediterranean diet, participates in the regulation of the intestinal circadian rhythm in patients with morbid obesity. METHODS: Stomach and jejunum explants from patients with morbid obesity were incubated with oleic acid to analyze the regulation of clock genes. RESULTS: Stomach explants showed an altered circadian rhythm in CLOCK, BMAL1, REVERBα, CRY1, and CRY2, and an absence in PER1, PER2, PER3 and ghrelin (p > 0.05). OA led to the emergence of rhythmicity in PER1, PER2, PER3 and ghrelin (p < 0.05). Jejunum explants showed an altered circadian rhythm in CLOCK, BMAL1, PER1 and PER3, and an absence in PER2, REVERBα, CRY1, CRY2 and GLP1 (p > 0.05). OA led to the emergence of rhythmicity in PER2, REVERBα, CRY1 and GLP1 (p < 0.05), but not in CRY2 (p > 0.05). OA restored the rhythmicity of acrophase and increased the amplitude for most of the genes studied in stomach and jejunum explants. OA placed PER1, PER2, PER3, REVERBα, CRY1 and CRY2 in antiphase with regard to CLOCK and BMAL1. CONCLUSIONS: There is an alteration in circadian rhythm in stomach and jejunum explants in morbid obesity. OA restored the rhythmicity of the genes related with circadian rhythm, ghrelin and GLP1, although with slight differences between tissues, which could determine a different behaviour of the explants from jejunum and stomach in obesity.

AMPK-Dependent Mechanisms but Not Hypothalamic Lipid Signaling Mediates GH-Secretory Responses to GHRH and Ghrelin.

GH (growth hormone) secretion/action is modulated by alterations in energy homeostasis, such as malnutrition and obesity. Recent data have uncovered the mechanism by which hypothalamic neurons sense nutrient bioavailability, with a relevant contribution of AMPK (AMP-activated protein kinase) and mTOR (mammalian Target of Rapamycin), as sensors of cellular energy status. However, whether central AMPK-mediated lipid signaling and mTOR participate in the regulation of pituitary GH secretion remains unexplored. We provide herein evidence for the involvement of hypothalamic AMPK signaling, but not hypothalamic lipid metabolism or CPT-1 (carnitine palmitoyltransferase I) activity, in the regulation of GH stimulatory responses to the two major elicitors of GH release in vivo, namely GHRH (growth hormone-releasing hormone) and ghrelin. This effect appeared to be GH-specific, as blocking of hypothalamic AMPK failed to influence GnRH (gonadotropin-releasing hormone)-induced LH (luteinizing hormone) secretion. Additionally, central mTOR inactivation did not alter GH responses to GHRH or ghrelin, nor this blockade affected LH responses to GnRH in vivo. In sum, we document here for the first time the indispensable and specific role of preserved central AMPK, but not mTOR, signaling, through a non-canonical lipid signaling pathway, for proper GH responses to GHRH and ghrelin in vivo.

Oleic Acid Protects Against Insulin Resistance by Regulating the Genes Related to the PI3K Signaling Pathway.

BACKGROUND: The effects of different types of fatty acids on the gene expression of key players in the IRS1/PI3K signaling pathway have been poorly studied. MATERIAL AND METHODS: We analyzed IRS1, p85α, and p110ß mRNA expression and the fatty acid composition of phospholipids in visceral adipose tissue from patients with morbid obesity and from non-obese patients. Moreover, we analyzed the expression of those genes in visceral adipocytes incubated with oleic, linoleic, palmitic and dosahexaenoic acids. RESULTS: We found a reduced IRS1 expression in patients with morbid obesity, independent of insulin resistance, and a reduced p110ß expression in those with lower insulin resistance. A positive correlation was found between p85α and stearic acid, and between IRS1 and p110ß with palmitic and dosahexaenoic acid. In contrast, a negative correlation was found between p85α and oleic acid, and between IRS1 and p110ß with linoleic, arachidonic and adrenic acid. Incubation with palmitic acid decreased IRS1 expression. p85α was down-regulated after incubation with oleic and dosahexaenoic acid and up-regulated with palmitic acid. p110ß expression was increased and decreased after incubation with oleic and palmitic acid, respectively. The ratio p85α/p110ß was decreased by oleic and dosahexaenoic acid and increased by palmitic acid. CONCLUSIONS: Our in vitro results suggest a detrimental role of palmitic acid on the expression of gene related to insulin signaling pathway, with oleic acid being the one with the higher and more beneficial effects. DHA had a slight beneficial effect. Fatty acid-induced regulation of genes related to the IRS1/PI3K pathway may be a novel mechanism by which fatty acids regulate insulin sensitivity in visceral adipocytes.

Different Expression of Duodenal Genes Related to Insulin Resistance Between Nonobese Women and Those with Severe Obesity.

OBJECTIVE: The study aim was to identify changes in duodenal gene expression associated with the development of insulin resistance according to the BMI of women. METHODS: Duodenal samples were assessed by microarray in four groups of women, nonobese women and women with severe obesity, with both low and high insulin resistance. RESULTS: There was a group of shared downregulated differentially expressed genes (DEGs) related to tissue homeostasis and antimicrobial humoral response in women with higher insulin resistance both with severe obesity and without obesity. In the exclusive DEGs found in severe obesity, downregulated DEGs related to the regulation of the defense response to bacterium and cell adhesion, involving pathways related to the immune system, inflammation, and xenobiotic metabolism, were observed. In the exclusive DEGs from nonobese women with higher insulin resistance, upregulated DEGs mainly related to the regulation of lipoprotein lipase activity, very low-density lipoprotein particle remodeling, lipid metabolic process, antigen processing, and the presentation of peptide antigen were found. CONCLUSIONS: Independent of BMI, higher insulin resistance was associated with a downregulation of duodenal DEGs mainly related to the immune system, inflammation, and xenobiotic metabolism. Also, intestinal lipoprotein metabolism may have a certain relevance in the regulation of insulin resistance in nonobese women.

Jejunal Insulin Signalling Is Increased in Morbidly Obese Subjects with High Insulin Resistance and Is Regulated by Insulin and Leptin.

Little is known about the jejunal insulin signalling pathways in insulin resistance/diabetes states and their possible regulation by insulin/leptin. We study in jejunum the relation between insulin signalling and insulin resistance in morbidly obese subjects with low (MO-low-IR) or with high insulin resistance (MO-high-IR), and with type 2 diabetes treated with metformin (MO-metf-T2DM)), and the effect of insulin/leptin on intestinal epithelial cells (IEC). Insulin receptor substrate-1 (IRS1) and the catalytic p110ß subunit (p110ß) of phosphatidylinositol 3-kinase (PI3K) were higher in MO-high-IR than in MO-low-IR. The regulatory p85α subunit of PI3K (p85α)/p110ß ratio was lower in MO-high-IR and MO-metf-T2DM than in MO-low-IR. Akt-phosphorylation in Ser473 was reduced in MO-high-IR compared with MO-low-IR. IRS1 and p110-ß were associated with insulin and leptin levels. The improvement of body mass index (BMI) and HOMA-IR (homeostasis model assessment of insulin resistance index) after bariatric surgery was associated with a higher IRS1 and a lower p85α/p110ß ratio. IEC (intestinal epithelial cells) incubation with a high glucose + insulin dose produced an increase of p85α and p110ß. High dose of leptin produced an increase of IRS1, p85α and p110ß. In conclusion, despite the existence of insulin resistance, the jejunal expression of genes involved in insulin signalling was increased in MO-high-IR. Their expressions were regulated mainly by leptin. IRS1 and p85α/p110ß ratio was associated with the evolution of insulin resistance after bariatric surgery.

Increased PON lactonase activity in morbidly obese patients is associated with impaired lipid profile.

AIMS: The paraoxonase-1 (PON1) enzyme could play an important role in the anti-oxidant capacity of high-density lipoprotein. However, there are no studies which analyse the evolution of the three activities of PON1 (PON arylesterase, PON paraoxonase and PON lactonase) after Roux-en-Y Gastric Bypass (RYGB) in morbidly obese subjects. We analysed the association of PON concentration and activities with the evolution of morbidly obese subjects who underwent RYGB, and its relationship with biochemical variables and different atherogenic indices. METHODS: Twenty-seven non-obese and 82 morbidly obese subjects were studied before and 6 months after RYGB. RESULTS: Before RYGB, morbidly obese subjects had a lower PON1 concentration (P < 0.05) and higher PON lactonase activity (P < 0.001) than non-obese subjects, with no differences in PON arylesterase and PON paraoxonase activities. After RYGB, PON1 concentration (P < 0.05) and PON lactonase activity (P < 0.001) decreased with regard to the presurgery state. PON lactonase activity correlated with the atherogenic index of plasma before (r = 0.19, P = 0.047) and after RYGB (r = 0.27, P = 0.035). In different multiple lineal regression analysis models, presurgery PON lactonase activity was associated with total cholesterol (ß = 0.909, P < 0.001), LDL (ß = 0.632, P = 0.006) and DBP (ß = 0.230, P = 0.030) (R2  = 0.295), postsurgery PON lactonase activity was associated with esterified cholesterol (ß = 0.362, P = 0.011) (R2  = 0.131), and the change (Δ) in PON lactonase activity after RYGB was associated with Δesterified cholesterol (ß = 0.304, P = 0.030) (R2  = 0.093). CONCLUSIONS: PON lactonase activity is associated with the presence of morbid obesity and with an impaired lipid profile. All associations found could indicate the relationship between PON lactonase activity and the development of atherosclerosis.

The changes in the transcriptomic profiling of subcutaneous adipose tissue after bariatric surgery depend on the insulin resistance state.

BACKGROUND: The changes that are produced in the gene expression of subcutaneous adipose tissue after Roux-en-Y gastric bypass are not yet fully known. OBJECTIVE: To identify the changes in the subcutaneous adipose tissue gene expression of morbidly obese women with low insulin resistance (MO-low-IR) and high insulin resistance (MO-high-IR) to find a relationship with measured obesity-related co-morbidities. SETTING: A university hospital. METHODS: Subcutaneous adipose tissue samples were assessed by microarray analysis before and 2 years after Roux-en-Y gastric bypass in MO-low-IR and MO-high-IR patients. RESULTS: There is a group of shared differentially expressed genes (DEG) in both MO-low-IR and MO-high-IR, also there is a group of exclusive DEG in MO-low-IR and another group in MO-high-IR. In MO-high-IR, the downexpressed DEG are related to the regulation of transcription and are involved in the pathways related to cytokine-cytokine receptor interaction, cancer, phosphatidylinositol 3-kinase-protein kinase B signaling, human T-lymphotropic virus I infection, chemokine signaling, and Janus kinase/signal transducers and activators of transcription signaling. In MO-low-IR, the overexpressed DEG are related to carbohydrate metabolic processes, the downexpressed DEG to the glycosaminoglycan metabolic process and regulation of translation, and the pathways are related to phosphatidylinositol 3-kinase-protein kinase B signaling and metabolic pathways. The fold change of DEG mainly correlates with the percentage of change (Δ) of waist, Δhip, Δglucose, and Δtriglycerides. These DEG were mainly related to cancer, inflammation/immune regulation, metabolic pathways, ribonucleic acid/deoxyribonucleic acid regulation, virus infection, and regulation of cellular proliferation. CONCLUSIONS: This study suggests a potential association between high insulin resistance and the expression of genes related to cancer and chronic immune activation/inflammation.

Tissue-Specific Phenotype and Activation of iNKT Cells in Morbidly Obese Subjects: Interaction with Adipocytes and Effect of Bariatric Surgery.

BACKGROUND: The immune response of visceral adipose tissue (VAT) in obesity, in particular the role of invariant natural killer T (iNKT) cells, has not yet been fully elucidated. OBJECTIVE: To characterize iNKT cells and its activation status in VAT and peripheral blood mononuclear cells (PBMC) in morbidly obese subjects (MO), and to analyze their association with metabolic parameters. SUBJECTS AND METHODS: Twenty non-obese and 20 MO subjects underwent Roux-en-Y gastric bypass (RYGB) and were studied before and 6 months after RYGB. VAT and PBMC were obtained. RESULTS: A decrease in VAT iNKT cells from MO was found, however, not in PBMC. Visceral adipocytes from MO presented increased CD1d expression (p = 0.032). MO presented an increase in early activated CD69+ iNKT cells in PBMC before RYGB (p < 0.001), but not after RYGB nor in VAT, and an increase in later activated CD25+ iNKT in VAT (p = 0.046), without differences in PBMC. The co-expression of early and later markers (CD69+CD25+) in iNKT cells was increased in MO in VAT (p = 0.050) and PBMC (p = 0.006), decreasing after RYGB (p = 0.050). CD69+ iNKT and CD69+CD25+ iNKT cells in PBMC after RYGB correlated negatively with glucose, insulin, and insulin resistance levels. CONCLUSIONS: There is a tissue-specific phenotype and activation of iNKT cells in VAT in morbid obesity, which could be involved in VAT immunometabolism dysregulation. Also, the increase in CD1d expression could be to offset the lack of VAT iNKT cells.

Dietary fatty acids modulate adipocyte TNFa production via regulation of its DNA promoter methylation levels.

The factors regulating TNF alpha (TNFa) levels could be considered therapeutic targets against metabolic syndrome development. DNA methylation is a potent regulator of gene expression and may be associated with protein levels. In this study we investigate whether the effect of dietary fatty acids on TNFa released from adipocytes might be associated with modifications of the TNFa promoter DNA methylation status. A group of rats was assigned to three diets with a different composition of saturated, monounsaturated and polyunsaturated fatty acids. Samples of visceral adipose tissues were taken for adipocyte isolation, in which released TNFa levels were measured, and for methylation and expression studies. In addition, 3 T3-L1 cells were treated with palmitic, oleic and linoleic acids, with and without 5-Azacitydine (5-AZA). After treatments, cells and supernatants were included in the same analyses as rat samples. TNFa promoter methylation levels, gene expression and secretion were different according to the diets and fatty acid treatments associated with them. Cells treated with 5-AZA displayed higher TNFa levels than in the absence of 5-AZA, without differences between fatty acids. According to our results, dietary fatty acid regulation of adipocyte TNFa levels may be mediated by epigenetic modifications of the TNFa promoter DNA methylation levels.

Changes in SCD gene DNA methylation after bariatric surgery in morbidly obese patients are associated with free fatty acids.

Stearoyl CoA Desaturase-1 (SCD) is considered as playing an important role in the explanation of obesity. The aim of this study was to evaluate whether the DNA methylation SCD gene promoter is associated with the metabolic improvement in morbidly obese patients after bariatric surgery. The study included 120 subjects with morbid obesity who underwent a laparoscopic Roux-en Y gastric by-pass (RYGB) and a control group of 30 obese subjects with a similar body mass index (BMI) to that found in morbidly obese subjects six months after RYGB. Fasting blood samples were obtained before and at six months after RYGB. DNA methylation was measured by pyrosequencing technology. DNA methylation levels of the SCD gene promoter were lower in morbidly obese subjects before bariatric surgery but increased after RYGB to levels similar to those found in the control group. Changes of DNA methylation SCD gene were associated with the changes of free fatty acids levels (r = -0.442, p = 0.006) and HOMA-IR (r = -0.249, p = 0.035) after surgery. RYGB produces an increase in the low SCD methylation promoter levels found in morbidly obese subjects. This change of SCD methylation levels is associated with changes in FFA and HOMA-IR.

Jejunal gluconeogenesis associated with insulin resistance level and its evolution after Roux-en-Y gastric bypass.

BACKGROUND: Intestinal gluconeogenesis (GNG) may play an important role in glucose homeostasis, but there is little information about the condition in humans. OBJECTIVES: To study the relationship between intestinal GNG and insulin resistance, its association with the evolution of morbidly obese patients after bariatric surgery, and the effect of insulin and or leptin. SETTING: Regional university hospital, Malaga (Spain). METHODS: Jejunal mRNA expression of genes involved in GNG was analyzed in 3 groups of morbidly obese patients who underwent Roux-en-Y gastric bypass: with low insulin resistance (MO-low-IR), with high insulin resistance (MO-high-IR), and with type 2 diabetes treated with metformin (MO-metf-T2D). Also, intestinal epithelial cells (IEC) from MO-low-IR were incubated with different doses of insulin and or leptin. RESULTS: In MO-high-IR, glutaminase, phosphoenolpyruvate carboxykinase (PEPCK), glucose 6-phosphatase (G6 Pase), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1 α), and sterol regulatory element-binding proteins 1 c (SREBP-1 c) expressions were significantly higher than in MO-low-IR. In MO-metf-T2 D, only PEPCK was significantly lower than in MO-high-IR. In IEC, an incubation with a high glucose and insulin dose produced an increase of PEPCK and SREBP-1 c, and a decrease of glutaminase, fructose 1,6-bisphosphatase (FBPase), and PGC-1 α expression. At high doses of leptin, G6 Pase and FBPase were significantly increased. The improvement of insulin resistance 3 months after bariatric surgery was positively associated with high G6 Pase and FBPase expression. CONCLUSION: mRNA expression of genes involved in GNG is increased in the jejunum of MO-high-IR, and regulated by insulin and or leptin. High mRNA expression of genes involved in GNG is associated with a better evolution of insulin resistance after bariatric surgery.

Methylation patterns of Vegfb promoter are associated with gene and protein expression levels: the effects of dietary fatty acids.

PURPOSE: We have investigated the epigenetic regulation by dietary fatty acids of Vegfb levels in rats' white adipose tissue and 3T3-L1 cells. METHODS: A group of rats were assigned to three diets, each one with a different composition of saturated, monounsaturated and polyunsaturated fatty acids. Samples of white adipose tissues were taken for the methylation and expression studies. Additionally, 3T3-L1 cells were treated with palmitic, oleic, and linoleic fatty acids. After treatment, cells were harvested and genetic material was extracted for the analysis of Vegfb levels. RESULTS: We report evidence of changes in the methylation levels of the CpG island at the Vegfb promoter and in the Vegfb expression levels in vivo and in vitro by dietary fatty acid, with the main contribution of the linoleic fatty acid. Vegfb promoter methylation levels were closely related to the Vegfb gene expression. CONCLUSION: According to our results, the regulation of Vegfb gene expression by dietary fatty acids may be mediated, at least in part, by epigenetic modifications on Vegfb promoter methylation. Considering the deep association between angiogenesis and tissue growth, we suggest the nutriepigenetic regulation of Vegfb as a key target in the control of the adipose tissue expansion.

The pro-/anti-inflammatory effects of different fatty acids on visceral adipocytes are partially mediated by GPR120.

PURPOSE: This study examines whether G-protein coupled receptor 120 (GPR120) is involved in the pro-/anti-inflammatory effects of different types of fatty acids (FAs) in human visceral adipocytes, and whether these effects may be altered in obesity, a state with a chronic inflammation. METHODS: Pro-/anti-inflammatory effects of palmitic, oleic, linoleic and docosahexaenoic acids on human visceral adipocytes were tested in mature adipocytes from non-obese and morbidly obese (MO) subjects. Also, the effects of these FAs were tested when the GPR120 gene was silenced. RESULTS: In adipocytes from non-obese subjects, palmitic and linoleic acids increased TNF-α and IL-6 mRNA expression (p < 0.05), and decreased IL-10 and adiponectin expression (p < 0.05). However, oleic and docosahexaenoic acids (DHA) produced the opposite effect (p < 0.05). In adipocytes from MO subjects, all FAs used increased TNF-α and IL-6 expression (p < 0.05). Palmitic and linoleic acids decreased IL-10 and adiponectin expression (p < 0.05), but oleic acid and DHA did not have significant effects. Only oleic acid increased adiponectin expression (p < 0.05). The effects of FAs on TNF-α, IL-6, IL-10 and adiponectin expression in non-obese and MO subjects were significantly annulled when the GPR120 gene was silenced in visceral adipocytes differentiated from human mesenchymal stem cells. CONCLUSIONS: FAs are capable of directly acting on visceral adipocytes to modulate differently TNF-α, IL-6, IL-10 and adiponectin expression, with a different and greater effect in MO subjects. These effects are largely annulled when GPR120 expression was silenced, which suggests that they could be mediated by GPR120.

GLP-1 and estrogen conjugate acts in the supramammillary nucleus to reduce food-reward and body weight.

The obesity epidemic continues unabated and currently available pharmacological treatments are not sufficiently effective. Combining gut/brain peptide, GLP-1, with estrogen into a conjugate may represent a novel, safe and potent, strategy to treat diabesity. Here we demonstrate that the central administration of GLP-1-estrogen conjugate reduced food reward, food intake, and body weight in rats. In order to determine the brain location of the interaction of GLP-1 with estrogen, we avail of single-photon emission computed tomography imaging of regional cerebral blood flow and pinpoint a brain site unexplored for its role in feeding and reward, the supramammillary nucleus (SUM) as a potential target of the conjugated GLP-1-estrogen. We confirm that conjugated GLP-1 and estrogen directly target the SUM with site-specific microinjections. Additional microinjections of GLP-1-estrogen into classic energy balance controlling nuclei, the lateral hypothalamus (LH) and the nucleus of the solitary tract (NTS) revealed that the metabolic benefits resulting from GLP-1-estrogen injections are mediated through the LH and to some extent by the NTS. In contrast, no additional benefit of the conjugate was noted on food reward when the compound was microinjected into the LH or the NTS, identifying the SUM as the only neural substrate identified here to underlie the reward reducing benefits of GLP-1 and estrogen conjugate. Collectively we discover a surprising neural substrate underlying food intake and reward effects of GLP-1 and estrogen and uncover a new brain area capable of regulating energy balance and reward.