An Intestinal FXR Agonist Mitigates Dysbiosis, Intestinal Tight Junctions, and Inflammation in High-Fat Diet-Fed Mice.

SCOPE: To analyze the effects of fexaramine (FEX), as an intestinal FXR agonist, on the modulation of the intestinal microbiota and ileum of mice fed a high-fat (HF) diet. METHODS AND RESULTS: Three-month-old C57Bl/6 male mice are divided into two groups and received a control (C, 10% of energy from lipids) or HF (50% of energy from lipids) diet for 12 weeks. They are subdivided into the C, C + FEX, HF, and HF + FEX groups. FEX is administered (FEX-5 mg kg-1 ) via orogastric gavage for three weeks. Body mass (BM), glucose metabolism, qPCR 16S rRNA gene expression, and ileum gene expression, bile acids (BAs), tight junctions (TJs), and incretin are analyzed. FEX reduces BM and glucose intolerance, reduces plasma lipid concentrations and the Firmicutes/Bacteroidetes ratio, increases the Lactobacillus sp. and Prevotella sp. abundance, and reduces the Escherichia coli abundance. Consequently, the ileal gene expression of Fxr-Fgf15, Tgr5-Glp1, and Cldn-Ocldn-Zo1 is increased, and Tlr4-Il6-Il1beta is decreased. CONCLUSION: FEX stimulates intestinal FXR and improves dysbiosis, intestinal TJs, and the release of incretins, mitigating glucose intolerance and BM increases induced by an HF diet. However, FEX results in glucose intolerance, insulin resistance, and reduces intestinal TJs in a control group, thus demonstrating limitations to this dietary model.

Semaglutide (GLP-1 receptor agonist) stimulates browning on subcutaneous fat adipocytes and mitigates inflammation and endoplasmic reticulum stress in visceral fat adipocytes of obese mice.

Semaglutide (GLP-1 agonist) was approved for treating obesity. Although the effects on weight loss and metabolism are known, the responses of adipocytes to semaglutide are yet limited. C57BL/6 male mice (n = 20/group) were fed a control diet (C) or a high-fat (HF) diet for 16 weeks and then separated into four groups (n = 10/group) for an additional four weeks: C, C diet and semaglutide, HF, and HF diet and semaglutide. Epididymal white adipose tissue (eWAT) and subcutaneous white adipose tissue (sWAT) fat pads were studied with biochemistry, immunohistochemistry/fluorescence, stereology, and reverse transcription-quantitative polymerase chain reaction. In obese mice, semaglutide reduced the fat pad masses (eWAT, -55%; sWAT, -40%), plasmatic cytokines, and proinflammatory gene expressions: tumor necrosis factor-alpha (-60%); interleukin (IL)-6 (-55%); IL-1 beta (-40%); monocyte chemoattractant protein-1 (-90%); and leptin (-80%). Semaglutide also lessened endoplasmic reticulum (ER) stress genes of activating transcription factor-4 (-85%), CCAAT enhancer-binding protein homologous protein (-55%), and growth arrest and DNA damage-inducible gene 45 (-45%). The obese mice's adipocyte hypertrophy and macrophage infiltration were equally reduced by semaglutide. Semaglutide enhanced multiloculation and uncoupled protein 1 (UCP1) labeling in obese mice: peroxisome proliferator-activated receptor-alpha (+560%) and gamma (+150%), fibronectin type III domain-containing protein 5 (+215%), peroxisome proliferator-activated receptor-alpha coactivator (+110%), nuclear respiratory factor 1 (+260%), and mitochondrial transcription factor A (+120%). Semaglutide also increased thermogenetic gene expressions for the browning phenotype maintenance: beta-3 adrenergic receptor (+520%), PR domain containing 16 (+90%), and Ucp1 (+110%). In conclusion, semaglutide showed significant beneficial effects beyond weight loss, directly on fat pads and adipocytes of obese mice, remarkably anti-inflammatory, and reduced adipocyte size and ER stress. Besides, semaglutide activated adipocyte browning, improving UCP1, mitochondrial biogenesis, and thermogenic marker expressions help weight loss.

Empagliflozin Alleviates Left Ventricle Hypertrophy in High-Fat-Fed Mice by Modulating Renin Angiotensin Pathway.

Aims. The cardiobenefits of empagliflozin are multidimensional, and some mechanisms are still unclear. The aim of the present study was to evaluate the effect of treatment with empagliflozin on biometric parameters and gene expression in the local cardiac RAS, oxidative stress, and endoplasmic reticulum pathways in a mouse model. Main Methods. Forty male C57BL/6 mice were fed with control (C) or high-fat (HF) diets for 10 weeks. After that, the groups were redistributed according to the treatment with empagliflozin-CE or HFE. The empagliflozin was administered via food for 5 weeks (10 mg/kg/day). We performed biochemical analyses, blood pressure monitoring, oral glucose tolerance test, left ventricle (LV) stereology, RT-qPCR for genes related to classical and counterregulatory local RAS, oxidative stress, and endoplasmic reticulum stress. Key Findings. In comparison to HF, HFE decreased body mass and improved glucose intolerance and insulin resistance. The cardiac parameters were enhanced after treatment as expressed by decrease in plasma cholesterol, plasma uric acid, and systolic blood pressure. In addition, LV analysis showed that empagliflozin reduces cardiomyocyte area and LV thickness. The local RAS had less activity of the classical pathway and positive effects on the counterregulatory pathway. Empagliflozin treatment also decreased oxidative stress and endoplasmic reticulum stress-related genes. Significance. Our results suggests that empagliflozin modulates the local RAS pathway towards alleviation of oxidative stress and ER stress in the LV, which may be a route to its effects on improved cardiac remodeling.

Anti-steatotic linagliptin pleiotropic effects encompasses suppression of de novo lipogenesis and ER stress in high-fat-fed mice.

AIM: To investigate the effects of linagliptin treatment on hepatic energy metabolism and ER stress in high-fat-fed C57BL/6 mice. METHODS: Forty male C57BL/6 mice, three months of age, received a control diet (C, 10% of lipids as energy, n = 20) or high-fat diet (HF, 50% of lipids as energy, n = 20) for 10 weeks. The groups were randomly subdivided into four groups to receive linagliptin, for five weeks, at a dose of 30 mg/kg/day added to the diets: C, C-L, HF, and HF-L groups. RESULTS: The HF group showed higher body mass, total and hepatic cholesterol levels and total and hepatic triacylglycerol levels than the C group, all of which were significantly diminished by linagliptin in the HF-L group. The HF group had higher hepatic steatosis than the C group, whereas linagliptin markedly reduced the hepatic steatosis (less 52%, P < 0.001). The expression of Sirt1 and Pgc1a was more significant in the HF-L group than in the HF group. Linagliptin also elicited enhanced GLP-1 concentrations and a reduction in the expression of the lipogenic genes Fas and Srebp1c. Besides, HF-L showed a reduction in the genes related to endoplasmic reticulum stress Chop, Atf4, and Gadd45 coupled with reduced apoptotic nuclei immunostaining. CONCLUSION: Linagliptin caused a marked reduction in hepatic steatosis as a secondary effect of its glucose-lowering property. NAFLD countering involved reduced lipogenesis, increased beta-oxidation, and relief in endoplasmic reticulum stress, leading to reduced apoptosis and better preservation of the hepatic structure. Therefore, linagliptin may be used, preferably in diabetic patients, to avoid the progression of hepatic steatosis.

Efectos metabólicos del consumo excesivo de fructosa añadida / Metabolic effects of excessive fructose consumption added

El consumo de fructosa ha aumentado en los últimos 50 años por la incorporación a la dieta de jarabe de maíz alto en fructosa (JMAF), presente en productos industrializados, como las bebidas azucaradas. Se puede asociar la ingesta de fructosa en altas concentraciones con el aumento de la obesidad y trastornos metabólicos. La fructosa, un azúcar natural que se encuentra en muchas frutas, se consume en cantidades significativas en las dietas occidentales. En cantidades iguales, es más dulce que la glucosa o la sacarosa y, por lo tanto, se usa comúnmente como edulcorante. Debido al incremento de obesidad entre la población joven y general y a los efectos negativos que puede tener a corto y largo plazo es importante considerar de donde provienen las calorías que se ingieren diariamente. Esta revisión describirá la relación entre el consumo de fructosa en altas concentraciones y el riesgo de desarrollar obesidad, resistencia a la insulina, lipogenesis de novo e inflamación.

The consumption of fructose has increased in the last 50 years due to the incorporation into the diet of high fructose corn syrup (HFCS), present in industrialized products, such as sugary drinks. The intake of fructose in high concentrations can be associated with the increase of obesity and metabolic disorders. Fructose, a natural sugar found in many fruits, is consumed in significant quantities in Western diets. In equal amounts, it is sweeter than glucose or sucrose and, therefore, is commonly used as a sweetener. Due to the increase of obesity among the young and general population and the negative effects that can have in the short and long term it is important to consider where the calories that are ingested daily come from. This review will describe the relationship between fructose consumption in high concentrations and the risk of developing obesity, insulin resistance, de novo lipogenesis, nonalcoholic fatty liver, inflammation and metabolic syndrome.

Empaglifozin mitigates NAFLD in high-fat-fed mice by alleviating insulin resistance, lipogenesis and ER stress.

AIM: To evaluate the pleiotropic effects of empagliflozin in the liver through lipogenesis, beta-oxidation, and endoplasmic reticulum stress pathways. METHODS: Male C57Bl/6 mice, 3 months of age, received a control diet (C, 10% lipids, n = 20) or high-fat diet (HF, 50% lipids, n = 20) for 10 weeks, after that, the groups were subdivided to receive empagliflozin, during 5 weeks at a dose of 10 mg/kg/day added to the diets, totalizing four groups: C, C-EMPA, HF, and HF-EMPA. We performed biochemical analyzes, oral glucose tolerance test, homeostasis model assessment of insulin resistance (HOMA-IR), indirect calorimetry, liver stereology, western blotting, RT-qPCR for genes related to beta-oxidation, lipogenesis, and endoplasmic reticulum stress. RESULTS: After the treatment with empagliflozin, there was a 4% increase in energy expenditure, a 5% reduction in body mass, improvement in glucose tolerance and insulin sensitivity and insulin resistance. The expression of Ppar alpha was greater in the HF-EMPA group with a concomitant reduction in the expression of the lipogenic genes Fas, Srebp1c and Ppar gamma, according to protein expression. In addition, HF-EMPA showed a reduction in the genes related to endoplasmic reticulum stress Chop, Atf4, and Gadd45. CONCLUSION: Empagliflozin mitigates the development of NAFLD, confirmed through reduced expression of the genes involved in hepatic lipogenesis and genes involved in endoplasmic reticulum stress. Thus, empagliflozin may be an important tool to treat the progression of hepatic steatosis.

Beneficial effects of losartan or telmisartan on the local hepatic renin-angiotensin system to counter obesity in an experimental model.

BACKGROUND: Obesity has been associated with hepatic overexpression of the renin-angiotensin system (RAS). AIM: To evaluate the action of two angiotensin II (ANGII) receptor blockers (losartan or telmisartan) on the modulation of local hepatic RAS and the resulting metabolic effects in a diet-induced obesity murine model. METHODS: Twenty C57BL/6 mice were randomly divided into two nutritional groups for 10 wk: control group (C, n = 5, 10% of energy as fat) or high-fat group (HF, n = 15, 50% of energy as fat). After treatment started, the HF group was randomly divided into three groups: untreated HF group (n = 5), HF treated with losartan (HFL, n = 5) and HF treated with telmisartan (HFT, n = 5). The treatments lasted for 5 wk, and the dose was 10 mg/kg body mass. RESULTS: HF diet induced body mass gain (+28%, P < 0.0001), insulin resistance (+69%, P = 0.0079), high hepatic triacylglycerol (+127%, P = 0.0004), and overexpression of intrahepatic angiotensin-converting enzyme (ACE) 1/ ANGII type 1 receptor (AT1r) (+569.02% and +141.40%, respectively, P < 0.0001). The HFL and HFT groups showed higher ACE2/rMAS gene expression compared to the HF group (ACE2: +465.57%, P = 0.0002 for HFL and +345.17%, P = 0.0049 for HFT; rMAS: +711.39%, P < 0.0001 for HFL and +539.75%, P < 0.0001 for HFT), followed by reduced insulin/glucose ratio (-30% for HFL and -33% for HFT, P = 0.0181), hepatic triacylglycerol levels (-28%, P = 0.0381 for HFL; and -45%, P = 0.0010 for HFT, and Plin2 expression. CONCLUSION: Modulation of the intrahepatic RAS, with favored involvement of the ACE2/rMAS axis over the ACE1/AT1r axis after losartan or telmisartan treatments, caused hepatic and metabolic beneficial effects as demonstrated by reduced hepatic triacylglycerol levels coupled with reduced PLIN 2 expression and improved glycemic control.

Beneficial effects of intermittent fasting on steatosis and inflammation of the liver in mice fed a high-fat or a high-fructose diet.

OBJECTIVE: Intermittent fasting (IF) is a nutritional intervention with significant metabolic effects on the liver that are not yet fully understood. The aim of this study was to investigate the effects of IF on body mass, lipid profile, glucose metabolism, liver lipogenesis, ß-oxidation, and inflammation. METHODS: We used cellular and molecular techniques to investigate the effects of IF on 3-mo-old male C57 BL/6 mice that were fed control (10% kcal fat), high-fat (HF; 50% kcal fat), or high-fructose (HFr; 50% kcal fructose) diets for 8 wk. Half of the animals were submitted to IF (1 d fed, 1 d fast) for an additional 4 wk. RESULTS: Although food intake on the fed day did not differ between the groups, mice in the HF and HFr groups showed diminished body mass, total cholesterol, and triacylglycerol levels. Also, plasma adiponectin increased in the HFr group and leptin decreased in the HF mice. Oral glucose tolerance test and insulin were ameliorated by IF, regardless of the diet consumed (HF or HFr), and decreased hepatic lipogenesis and increased ß-oxidation markers, resulting in a reduction of the hepatic steatosis and inflammation. CONCLUSIONS: There were beneficial effects of IF even with the continuity of the obesogenic diet and proinflammatory diet in mice. It is recommended that based on the beneficial effects of IF on glucose and liver metabolism and inflammation that IF be a coadjutant factor in the treatment of hepatic metabolic issues and steatosis.

Intermittent fasting exerts beneficial metabolic effects on blood pressure and cardiac structure by modulating local renin-angiotensin system in the heart of mice fed high-fat or high-fructose diets.

Intermittent fasting (IF) sets the preference for fats as fuel and is linked to beneficial metabolic outcomes; however, the effects in the renin-angiotensin system (RAS) in the heart remains to be determined. We hypothesized that IF improves blood pressure and lipid profiles due to a less activated local RAS in the left ventricle of mice, irrespective of the dietary scheme. This study aimed to evaluate the effects of intermittent fasting on cardiovascular parameters and local RAS in the left ventricle (LV) of mice fed either a high-fat (HF) or high-fructose diet (HFru). Metabolic alterations were induced in C57BL/6 mice by providing them free access to a high-fat or a high-fructose (HFru) diet for 8 weeks. Following the 8-week metabolic alteration period, the mice were subjected to the IF protocol in which mice were deprived of food for 24 hours, every other day, for a period of 4 weeks. The IF protocol caused significant reduction in body weight, systolic blood pressure, blood glucose, total cholesterol, and triacylglycerol levels, in addition to augmenting the plasma and urinary uric acid levels, irrespective of the diet. Post IF protocol, beneficial LV remodeling was observed in animals fed either diet and included reduced LV mass, thickness, and cardiomyocyte cross-sectional area. These results comply with the improved RAS modulation, which favored ACE2/MAS receptor axis over the renin/ACE/AT1 axis. In conclusion, the significant decrease in weight brought about as a result of the IF protocol lead to modulation of the local RAS, with the consequential benefit of LV remodeling and reduction in blood pressure, irrespective of the diet.

High-intensity interval training has beneficial effects on cardiac remodeling through local renin-angiotensin system modulation in mice fed high-fat or high-fructose diets.

AIMS: HIIT (high-intensity interval training) has the potential to reduce cardiometabolic risk factors, but the effects on cardiac remodeling and local RAS (renin-angiotensin system) in mice fed high-fat or high-fructose diets still need to be fully addressed. MAIN METHODS: Sixty male C57BL/6 mice (12weeks old) were randomly divided into three groups, control (C), High-fat (HF), or High-fructose diet (HRU) and were monitored for eight weeks before being submitted to the HIIT. Each group was randomly assigned to 2 subgroups, one subgroup was started on a 12-week HIIT protocol (T=trained group), while the other subgroup remained non-exercised (NT=not-trained group). KEY FINDINGS: HIIT reduced BM and systolic blood pressure in high-fat groups, while enhanced insulin sensitivity after high-fat or high-fructose intake. Moreover, HIIT reduced left ventricular hypertrophy in HF-T and HFRU-T. Notably, HIIT modulated key factors in the local left ventricular renin-angiotensin-system (RAS): reduced protein expression of renin, ACE (Angiotensin-converting enzyme), and (Angiotensin type 2 receptor) AT2R in HF-T and HFRU-T groups but reduced (Angiotensin type 1 receptor) AT1R protein expression only in the high-fat trained group. HIIT modulated ACE2/Ang (1-7)/Mas receptor axis. ACE2 mRNA gene expression was enhanced in HF-T and HFRU-T groups, complying with elevated Mas (Mas proto-oncogene, G protein-coupled receptor) receptor mRNA gene expression after HIIT. SIGNIFICANCE: This study shows the effectiveness of HIIT sessions in producing improvements in insulin sensitivity and mitigating LV hypertrophy, though hypertension was controlled only in the high-fat-fed submitted to HIIT protocol. Local RAS system in the heart mediates these findings and receptor MAS seems to play a pivotal role when it comes to the amelioration of cardiac structural and functional remodeling due to HIIT.

NAFLD e ingesta de fructosa en altas concentraciones: una revisión de la literatura / NAFLD and high fructose intake: a review of literature

Uno de los endulzantes más comúnmente utilizado es la fructosa. La fructosa es directamente metabolizada en el hígado y se puede transformar en glucosa, posteriormente es almacenada como glicógeno constituyéndose en una fuente de energía para los hepatocitos. Todo el exceso de fructosa se convierte en lípidos ejerciendo un efecto tóxico sobre el hígado, similar al producido por el exceso de alcohol, pudiendo provocar hígado graso no alcohólico (NAFLD). El objetivo de esta revisión es reunir hallazgos recientes en relación al efecto de la ingesta de fructosa en altas concentraciones y su relación con el NAFLD.

One of the most commonly used sweeteners is fructose. Fructose is directly metabolized in the liver and can be converted into glucose, later stored as glycogen constituting a source of energy for the hepatocytes. All excess fructose is converted into lipids by exerting a toxic effect on the liver, similar to that produced by excess of alcohol, and can cause nonalcoholic fatty liver (NAFLD). The aim of this review is to gather recent findings regarding the effect of fructose intake at high concentrations and its relationship with NAFLD.

Liver and Metformin: Lessons of a fructose diet in mice.

Studies show that the continuous consumption of fructose can lead to nonalcoholic fatty liver disease (NAFLD) and steatohepatitis. We aimed to investigate the role of Metformin in an animal model of liver injury caused by fructose intake, focusing on the molecular markers of lipogenesis, beta-oxidation, and antioxidant defenses. Male three months old C57BL/6 mice were divided into control group (C) and fructose group (F, 47% fructose), maintained for ten weeks. After, the groups received Metformin or vehicle for a further eight weeks: control (C), control + Metformin (CM), fructose (F), and fructose + Metformin (FM). Fructose resulted in hepatic steatosis, insulin resistance and lower insulin sensitivity in association with higher mRNA levels of proteins linked with de novo lipogenesis and increased lipid peroxidation. Fructose diminished mRNA expression of antioxidant enzymes, and of proteins responsible for mitochondrial biogenesis. Metformin reduced de novo lipogenesis and increased the expression of proteins related to mitochondrial biogenesis, thereby increasing beta-oxidation and decreasing lipid peroxidation. Also, Metformin upregulated the expression and activity of antioxidant enzymes, providing a defense against increased reactive oxygen species generation. Therefore, a significant reduction in triglyceride accumulation in the liver, steatosis and lipid peroxidation was observed in the FM group. In conclusion, fructose increases de novo lipogenesis, reduces the antioxidant defenses, and diminishes mitochondrial biogenesis. After an extended period of fructose intake, Metformin treatment, even in continuing the fructose intake, can reverse, at least partially, the liver injury and prevents NAFLD progression to more severe states.

AT1 receptor antagonist induces thermogenic beige adipocytes in the inguinal white adipose tissue of obese mice.

PURPOSE: To evaluate whether losartan is able to induce beige adipocytes formation, focusing on the thermogenic gene expression and adipocyte remodeling in the subcutaneous white adipose tissue of diet-induced obese mice. METHODS: Male C57BL/6 mice received a control diet (10% energy as lipids) or a high-fat diet (50% energy as lipids) for 10 weeks, followed by a 5-week treatment with losartan: control group, control-losartan group (10 mg/Kg/day), high-fat group and high-fat-losartan group (10 mg/Kg/day). Biochemical, morphometrical, stereological and molecular approaches were used to evaluate the outcomes. RESULTS: The high-fat diet elicited overweight, insulin resistance and adipocyte hypertrophy in the high-fat group, all of which losartan rescued in the high-fat-losartan group. These effects comply with the induction of beige adipocytes within the inguinal fat pads in high-fat-losartan group as they exhibited the greatest energy expenditure among the groups along with the presence uncoupling protein 1 positive multilocular adipocytes with enhanced peroxisome proliferator-activated receptor gamma coactivator 1-alpha and PR domain containing 16 mRNA levels, indicating a significant potential for mitochondrial biogenesis and adaptive thermogenesis. CONCLUSIONS: Our results show compelling evidence that losartan countered diet-induced obesity in mice by enhancing energy expenditure through beige adipocytes induction. Reduced body mass, increased insulin sensitivity, decreased adipocyte size and marked expression of uncoupling protein 1 by ectopic multilocular adipocytes support these findings. The use of losartan as a coadjutant medicine to tackle obesity and its related disorders merits further investigation.

Rosuvastatin limits the activation of hepatic stellate cells in diet-induced obese mice.

AIM: The aim of this study was to investigate the effects of rosuvastatin in a model of diet-induced obesity and non-alcoholic fatty liver disease, with attention to the activation of hepatic stellate cells (HSCs). METHOD: Male C57BL/6 mice received a control diet (C; 10% energy as lipids) or a high-fat diet (HF; 50% energy as lipids) for 12 weeks, followed by 7 weeks of treatment. Group CR received control diet + rosuvastatin; group HFR received high-fat diet + rosuvastatin. RESULTS: The HF group showed higher insulin, total cholesterol, triacylglycerol, and leptin levels than the C group, all of which were significantly diminished by rosuvastatin in the HFR group. The HF group had greater steatosis and activated HSCs than the C group, whereas rosuvastatin diminished the steatosis (less 21%, P < 0.001) and significantly inhibited the activation of the HSCs in the HFR group compared to the HF group. The sterol regulatory element-binding protein-1 and the peroxisome proliferator-activated receptor (PPAR)-γ protein expressions were increased in HF animals and reduced after treatment in the HFR group. By contrast, low PPAR-α and carnitine palmitoyltransferase-1 expressions were found in the HF group, and were restored by rosuvastatin treatment in the HFR group. CONCLUSION: Rosuvastatin mitigated hepatic steatosis by modulating PPAR balance, favoring PPAR-α over PPAR-γ downstream effects. The effects were accompanied by a diminishing of insulin resistance, the anti-inflammatory adipokine profile, and HSC activation, avoiding non-alcoholic fatty liver disease progression and non-alcoholic steatohepatitis onset in this model.

Differential effects of angiotensin receptor blockers on pancreatic islet remodelling and glucose homeostasis in diet-induced obese mice.

Obesity leads to adverse endocrine pancreas remodelling, reduced islet lifespan and early type 2 diabetes onset. AT1R blockade shows beneficial pleiotropic effects. This study sought to compare the effects of losartan and telmisartan on pancreatic islets remodelling and glucose homeostasis in diet-induced obese mice. High-fat diet yielded overweight, insulin resistance, islet apoptosis and hypertrophy. Suitable insulin levels and preserved endocrine pancreas structure were correlated to adequate AKT-FOXO1 pathway functioning in losartan-treated animals. Conversely, telmisartan yielded enhanced PDX1 and GLP-1 islet expression along with greater GLP-1 levels, with the consequent better islet glucose sensing and uptake. Greater islet vascularisation coupled with reduced apoptosis and macrophage infiltration seems to underlie the beneficial findings in both treatments. In conclusion, these results provide compelling evidence that two antihypertensive drugs (telmisartan and losartan) ameliorate pancreatic islet structure, glucose handling, and vascularisation in obese mice. Although only telmisartan countered overweight, both drugs yielded reduced apoptosis and islet preservation, with translational potential.

Maternal vitamin D-restricted diet has consequences in the formation of pancreatic islet/insulin-signaling in the adult offspring of mice.

The maternal deficiency of vitamin D can act on organogenesis in mice offspring, being a risk factor for chronic diseases in adulthood. This study investigates the effects of maternal deficiency of vitamin D on structural islet remodeling and insulin-signaling pathway in the offspring. We studied male C57Bl/6 offspring at 3-month old (n = 10/group) from mother fed one of the two diets: control diet (C) or vitamin D-restricted diet (VitD-). After weaning, offspring only fed the control diet ad libitum. In the offspring, we studied insulin production, islet remodeling, and islet protein expression of the insulin-signaling pathway (Western blotting, isolated islet, n = 5/group). VitD- offspring showed greater glycemia (P = 0.012), smaller beta-cell mass (P = 0.014), and hypoinsulinemia (P = 0.024) than C offspring. Comparing VitD- offspring with C offspring, we observed lower protein levels in islet of insulin (P = 0.003), insulin receptor substrate-1 (P = 0.025), phosphatidylinositol-3-kinases (P = 0.045), 3-phosphoinositide-dependent protein kinase 1 (P = 0.017), protein kinase B (P = 0.028), with reduced expression of pancreas/duodenum homeobox-1 (PDX-1) (P = 0.016), glucose transporter-2 (P = 0.003), and glucokinase (P = 0.045). The maternal vitamin D-restricted diet modifies the development of the pancreas of the offspring, leading to islet remodeling and altered insulin-signaling pathway. The decrease of PDX-1 is probably significant to the changes in the beta-cell mass and insulin secretion in adulthood.

Both hepatic lipogenesis and beta-oxidation are altered in offspring of mothers fed a high-fat diet in the first two generations (F1 and F2) / La lipogénesis hepática y la beta-oxidación están alteradas en las crías de madres alimentadas con una dieta alta en grasas en las dos primeras generaciones (F1 y F2)

The high fat (HF) fed mothers may program susceptibility in offspring to chronic diseases and affect subsequent generations. The present study evaluated the liver structure in adulthood, focusing on the F1 and F2 generations. Females C57BL/6 (F0) were fed standard chow (SC) or HF diet (8 weeks) prior to mating and during the gestation and lactation to provide the F1 generation (SC-F1 and HF-F1). All other mothers and offspring fed SC. At 3 months old, F1 females were mated to produce the F2 generation (SC-F2 and HF-F2). The liver was kept in several fragments and prepared for histological analysis or frozen for biochemical and molecular analyzes. The F1 and F2 offspring were studied at 3 months old. HF-F1 had higher body mass (BM) compared to SC-F1 (P= 0.001), but not HF-F2 compared to SC-F2. HF-F1 had glucose intolerance when compared to SC-F1, but not HF-F2 compared to SC-F2. HF-F1 (P= 0.009) and HF-F2 (P= 0.03) showed hyperinsulinemia compared to their counterparts. Both groups HF-F1 and HF-F2 showed more steatosis than the SC counterparts (F1 and F2, P<0.0001). HF-F1 showed increased expression of PPAR-gamma and SREBP1-c compared to SC-F1 (P= 0.01). HF-F2 showed increased PPAR-gamma expression compared to SC-F2 (P= 0.04). In conclusion, HF-fed mother impairs both lipogenesis and beta-oxidation pathways in F1 through upregulation of PPAR-gamma and downregulation of PPAR-alpha. In F2, the only lipogenesis is enhanced, but it causes a disrupted PPAR balance, favoring the hepatic lipid accumulation and impaired metabolism in these animals that were not directly exposed to the maternal HF intake.

Los madres alimentadas con dieta rica en grasas (HF) pueden programar una susceptibilidad al desarrollo de enfermedades crónicas en su descendencia y de este modo afectar a las generaciones posteriores. El presente estudio evaluó la estructura del hígado en la edad adulta, centrándose en las generaciones F1 y F2. Las hembras C57BL/6 (F0) fueron alimentadas con dieta estándar (CS) o dieta HF (8 semanas) antes del apareamiento y durante la gestación y lactancia para producir la generación F1 (CS-F1 y HF-F1). Todas las demás madres y crías fueron alimentadas con CS. A los 3 meses de edad, las hembras F1 fueron apareadas para producir la generación F2 (CS-F2 y HF-F2). El hígado se conservó en varios fragmentos y se preparó, por un lado, para el análisis histológico, y por otro, se lo congeló para realizar análisis bioquímicos y moleculares. La descendencia F1 y F2 se estudió a los 3 meses de edad. HF-F1 tuvo una mayor masa corporal (BM) en comparación con CS-F1 (P= 0,001), pero no el grupo HF-F2 en comparación con CS-F2. HF-F1 tenía intolerancia a la glucosa en comparación con CS-F1, pero no el grupo HF-F2 en comparación con CS-F2. HF-F1 (P= 0,009) y HF-F2 (P= 0,03) mostraron hiperinsulinemia en comparación con sus homólogos. Ambos grupos HF-F1 y HF-F2 mostraron más esteatosis que las contrapartes CS (F1 y F2, P <0,0001). HF-F1 mostró una mayor expresión de PPAR-gamma y SREBP1-c en comparación con el grupo CS-F1 (P= 0,01). HF-F2 mostró aumento de la expresión de PPAR-gamma en comparación con CS-F2 (P= 0,04). En conclusión, la madre alimentada con HF presenta ambas vías afectadas, de lipogénesis y de la beta-oxidación, en la F1 a través de la regulación positiva de PPAR-gamma y con regulación a la baja de los PPAR-alfa. En F2, solo ha mejorado la vía de lipogénesis, pero causa un desbalance de PPAR, lo que favorece la acumulación de lípidos hepáticos y la alteración del metabolismo en estos animales que no estaban directamente expuestos a la ingesta materna de HF.

Differences and similarities in hepatic lipogenesis, gluconeogenesis and oxidative imbalance in mice fed diets rich in fructose or sucrose.

Changes in feeding habits are the primary environmental factors (though modifiable) commonly correlated with increase in diseases such as obesity and associated comorbidities. Diets rich in fructose and sucrose have been related to the epidemic of obesity. Three groups of mice were studied during 15 weeks of consuming standard chow (SC), a high-fructose diet (HFru) and a high-sucrose diet (HSu). The animals did not present significant differences in food intake, energy intake, or body mass evolution at the end of the experiment. Although the findings in the HFru and HSu animals were not equal in magnitude, in comparison with the SC mice, the HFru and HSu animals showed hyperglycemia, hyperinsulinemia and hyperleptinemia as well as high levels of inflammatory adipokines, low adiponectin, and high levels of total cholesterol, triacylglycerol, and liver enzymes. The liver of HFru (more) and HSu (less) groups showed fatty infiltration and areas of necroinflammation, which are characteristic of the transition from nonalcoholic fatty liver disease to nonalcoholic steatohepatitis. In addition, the HFru and HSu groups showed increased lipogenesis, gluconeogenesis, reduced beta-oxidation and antioxidant imbalance compared with the SC animals. In conclusion, current findings demonstrate comparable adverse effects on carbohydrate metabolism, inflammatory profile, antioxidant imbalance and NAFLD in the mice of the C57BL/6 strain fed a diet rich in sucrose or rich in fructose.

Singular effects of PPAR agonists on nonalcoholic fatty liver disease of diet-induced obese mice.

AIMS: To assess the effects of peroxisome proliferator-activated receptor (PPAR) agonists on glucose tolerance and hepatic lipid metabolism in diet-induced obese mice. MAIN METHODS: Male C57BL/6 mice received a standard chow diet (SC, 10% energy as lipids) or high-fat diet (HF, 50% energy as lipids) for 10 weeks, after which treatment was initiated, forming the groups: SC group, HF group, HF-BZ group (HF + bezafibrate, pan-PPAR agonist), HF-WY group (HF + WY-14643, PPARalpha agonist) and HF-GW group (HF + GW1929, PPARgamma agonist). Treatments lasted for four weeks. Insulin resistance and liver remodeling were evaluated by biochemical and molecular approaches. KEY FINDINGS: The HF and HF-GW mice were overweight. Conversely, the HF-BZ and HF-WY mice presented with body masses equal to those of the SC mice. All treatments restored insulin sensitivity and blood lipid and adiponectin levels. Hepatic steatosis was prevented in the HF-WY and HF-BZ mice as shown by the elevated mRNA levels of PPARalpha and Carnitine palmitoyl transferase-1a in both groups, which favored enhanced beta-oxidation. Marked decreases in liver triacylglycerol levels confirmed these findings. In contrast, the HF-GW mice exhibited increased PPARgamma and fatty acid translocase/CD136 mRNA levels, contributing to enhanced hepatic lipogenesis. SIGNIFICANCE: The WY14643 and bezafibrate treatments most effectively improved the adverse metabolic and hepatic effects caused by obesity and IR. The results reinforce the central role of PPARalpha, as well as its contrary relationship to PPARgamma in the regulation of metabolic homeostasis and lipolytic pathways in the liver.

Animal models of nutritional induction of type 2 diabetes mellitus / Modelos animales de inducción nutricional para diabetes mellitus tipo 2

Type 2 diabetes mellitus (DM2) is the most common chronic metabolic disease, affecting approximately 6% of the adult population in the Western world. This condition is a major cause of cardiovascular disease, blindness, renal failure, and amputations, with increasing prevalence worldwide. The inuence of obesity on type 2 diabetes risk is determined by the degree of obesity and by body fat localization, with insulin resistance (IR) being the main link between these metabolic diseases. Experimental studies have shown that dietary factors, and particularly lipids, are strongly positively associated with body mass (BM) gain; IR; and, consequently, type 2 diabetes. Similarly, excessive consumption of energy-dense carbohydrate-rich foods can trigger the onset of type 2 diabetes. Additionally, maternal dietary inadequacies at conception and/or during the gestational period have been proposed to lead to developmental programming of excessive BM gain and metabolic disturbances in offspring, such as abnormal glucose homeostasis, reduced whole-body insulin sensitivity, impaired beta-cell insulin secretion and changes in the structure of the pancreas. Metabolic disruption is strongly associated with deleterious effects on beta-cell development and function. However, alterations in the amount and quality of dietary fat can modify glucose metabolism and insulin sensitivity. In this way, certain oils have gained attention in experimental research for their beneficial effects. Olive oil, a source of monounsaturated fatty acids (MUFAs), got attention in the past for its capacity to prevent cardiovascular diseases. Nevertheless, it is currently known that this oil also improves insulin sensitivity and glycemic control. Canola oil, flaxseed oil and especially fish oil (rich in n-3 polyunsaturated fatty acids) were first described as effective dietary nutrients against hypertriglyceridemia but now are known to have positive effects on glucose metabolism as well.

La diabetes mellitus tipo 2 (DM2) es la enfermedad metabólica crónica más común, afectando aproximadamente al 6% de la población adulta en el mundo occidental. Esta condición es una causa importante de las enfermedades cardiovasculares, la ceguera, la insuficiencia renal, y las amputaciones, con un aumento de su prevalencia en todo el mundo. El riesgo de obesidad en la diabetes tipo 2 está determinado por el grado de obesidad y localización de la grasa corporal, siendo la resistencia a la insulina (RI) la principal relación entre estas enfermedades metabólicas. Los estudios experimentales han demostrado que los factores dietéticos, y en particular los lípidos, se asocian de manera importante con la masa corporal (MC), la IR y la diabetes tipo 2. Asimismo, el consumo excesivo de alimentos ricos en carbohidratos de alto contenido energético pueden provocar la diabetes tipo 2. Además, se ha sugerido que una dieta materna inadecuada al momento de concebir o durante el período de gestación daría lugar al desarrollo de la excesiva MC y de trastornos metabólicos en los hijos, tales como la homeostasis anormal de la glucosa, reducción de la sensibilidad a la insulina en todo el cuerpo, el deterioro en la función de células beta, resistencia a la insulina y cambios en la estructura del páncreas. La alteración metabólica está asociada de forma importante con los efectos dañinos sobre el desarrollo y función de las células beta. Sin embargo, las alteraciones en la cantidad y la calidad de la grasa dietética pueden modificar el metabolismo de la glucosa como también la sensibilidad a la insulina. De esta manera, la investigación experimental ha enfocado la atención en algunos aceites debido a sus efectos beneficiosos. El aceite de oliva, es una fuente de monoinsaturados y actualmente se sabe que este aceite también mejora la sensibilidad a la insulina y el control glucémico El aceite de canola, el aceite de linaza y especialmente el aceite de pescado (rico en omega-3 los ácidos grasos poliinsaturados (PUFAs)) fueron descritos por primera vez como nutrientes de la dieta eficaces contra la hipertrigliceridemia, sin embargo, es sabido que además tienen efectos positivos sobre el metabolismo de la glucosa.