Standard Chow Group Research Articles

High-fat diet-induced obesity exacerbated collagenase-induced tendon injury with upregulation of interleukin-1beta and matrix metalloproteinase-1

ABSTRACT Aims Obesity increases tendinopathy’s risk, but its mechanisms remain unclear. This study examined the effect of high-fat diet (HFD)-induced obesity on the outcomes and inflammation of collagenase-induced (CI) tendon injury. Methods Mice were fed with standard chow (SC) or HFD for 12 weeks. Bacterial collagenase I or saline was injected over the patellar tendons of each mouse. At weeks 2 and 8 post-injection, the patellar tendons were harvested for histology, immunohistochemical staining, and gait analysis. The difference (Δ) of limb-idleness index (LII) at the time of post-injury and pre-injury states was calculated. Biomechanical test of tendons was also performed at week 8 post-injection. Results HFD aggravated CI tendon injury with an increase in vascularity and cellularity compared to SC treatment. The histopathological score (week 2: p = 0.025; week 8: p = 0.013) and ΔLII (week 2: p = 0.012; week 8: p = 0.005) were significantly higher in the HFD group compared to those in the SC group after CI tendon injury. Stiffness (saline: p = 0.003; CI: p = 0.010), ultimate stress (saline: p < 0.001; CI: p = 0.006), and Young’s modulus (saline: p = 0.017; CI: p = 0.007) were significantly lower in the HFD group compared to the SC group at week 8 after saline or collagenase injection. HFD induced higher expression of IL-1β (week 2: p = 0.010; week 8: p = 0.025) and MMP-1 (week 2: p = 0.010; week 8: p = 0.004) compared to SC treatment after CI tendon injury at both time points. Conclusions HFD-induced obesity exacerbated histopathological, functional, and biomechanical changes in the CI tendon injury model, which was associated with an upregulation of IL-1β and MMP-1.

A Novel Mouse Model of Physical Inactivity to Study the Role of Mitochondria in Chronic Kidney Disease

Chronic kidney disease (CKD) is a progressive disorder marked by a decline in kidney function. It is thought that a decline in mitochondrial function likely contributes to the pathogenesis of CKD, but the detailed mechanisms remain unclear. This gap in knowledge is contributed by a lack of a murine CKD model that does not rely on injury, toxin, or gene deletion to induce reduced kidney function. In humans, obesity and sedentary behavior strongly contribute to the development of CKD. The aim of the study was to employ small mouse cage (SMC) housing, a novel mouse physical inactivity model that was recently developed in our lab, and test whether it can be used to reliably induce CKD in mice. Wildtype C57BL6J mice were given standard chow or Western high-fat diet (HFD) with or without SMC intervention for 24 weeks to examine the effects of HFD and SMC on glomerular filtration rate (GFR) and respiration on isolated mitochondria from kidney cortex. Although the GFR values of the HFD+SMC group trended higher than other groups, the kidney function was still considered to be normal. Neither HFD nor HFD+SMC group had developed CKD, but mitochondrial respiration of SMC+HFD (1512.64 ± 77.86 pmol·sec−1·mgprotein−1) was significantly greater than that of the HFD-only group (1307.82 ± 79.08 pmol·sec−1·mgprotein−1, p = 0.0017) or the standard chow group (1104.69 ±143.12 pmol·sec−1·mgprotein−1, p = 0.0314. One-way ANOVA followed by Tukey’s test for multiple comparisons). Increased mitochondrial respiration may suggest a hyperfiltration-induced stress response, as commonly observed in the early stages of CKD in humans, and/or an increase in respiration to compensate for reduced effciency of oxidative phosphorylation. We interpret these data to mean that HFD and HFD+SMC are beginning to show adaptations that are in an early phase of CKD development. However, this model requires further optimization to yield the CKD phenotype. Therefore, we intend to further adapt the intervention to induce symptomatic CKD. We envision that developing preclinical models of CKD will help better elucidate its molecular mechanism and identify therapeutic targets for treating CKD in human patients. DK107397, DK127979. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Restricting Branched-Chain Amino Acids within a High-Fat Diet Prevents Obesity.

Obesity is a global pandemic, but there is yet no effective measure to control it. Recent metabolomics studies have identified a signature of altered amino acid profiles to be associated with obesity, but it is unclear whether these findings have actionable clinical potential. The aims of this study were to reveal the metabolic alterations of obesity and to explore potential strategies to mitigate obesity. We performed targeted metabolomic profiling of the plasma/serum samples collected from six independent cohorts and conducted an individual data meta-analysis of metabolomics for body mass index (BMI) and obesity. Based on the findings, we hypothesized that restriction of branched-chain amino acids (BCAAs), phenylalanine, or tryptophan may prevent obesity and tested our hypothesis in a dietary restriction trial with eight groups of 4-week-old male C57BL/6J mice (n = 5/group) on eight different types of diets, respectively, for 16 weeks. A total of 3397 individuals were included in the meta-analysis. The mean BMI was 30.7 ± 6.1 kg/m2, and 49% of participants were obese. Fifty-eight metabolites were associated with BMI and obesity (all p ≤ 2.58 × 10−4), linked to alterations of the BCAA, phenylalanine, tryptophan, and phospholipid metabolic pathways. The restriction of BCAAs within a high-fat diet (HFD) maintained the mice’s weight, fat and lean volume, subcutaneous and visceral adipose tissue weight, and serum glucose and insulin at levels similar to those in the standard chow group, and prevented obesity, adipocyte hypertrophy, adipose inflammation, and insulin resistance induced by HFD. Our data suggest that four metabolic pathways, BCAA, phenylalanine, tryptophan, and phospholipid metabolic pathways, are altered in obesity and restriction of BCAAs within a HFD can prevent the development of obesity and insulin resistance in mice, providing a promising strategy to potentially mitigate diet-induced obesity.

Effects of ketogenic and western diets on proliferation, vasculogenesis and oxidative stress in the liver

In this study, it was aimed to investigate the effects of different diets on lipid peroxidation, antioxidants, proliferation and vasculogenesis in liver tissue. BALBC female rats (21) were divided as the group fed with standard chow (SC), the group fed with a ketogenic diet (KD) and the group fed with western diet (WD). The rats were fed with tap water and a rat diet specially prepared according to the determined diets for four weeks. Liver tissue oxidative damage, proliferation and vasculogenesis were evaluated using spectrophotometric and immunohistopathological methods. At the end of the experiment, it was found that the highest weight gain was in the WD group and the least weight gain was in the KD group. The mean body weight of the WD group was statistically significantly higher compared to the SC and KD groups (p&lt;0.05). MDA levels were found to be lower in the KD group compared to the SC and WD groups. GSH and CAT levels were higher in the KD group compared to the SC and WD groups. In IHC evaluation results, it was seen that Ki-67 percentage in the KD group increased compared to the WD and SC groups (p = 0.000), VEGF was close to each other in all three groups and there was no significant difference in the comparisons between groups (p&gt;0.05). These results revealed that ketogenic diet prevents tissue damage by decreasing lipid peroxidation in liver tissue as well as inducing cellular proliferation and vasculogenesis.

Effects of ketogenic and western diets on proliferation, vasculogenesis and oxidative stress in the liver

In this study, it was aimed to investigate the effects of different diets on lipid peroxidation, antioxidants, proliferation and vasculogenesis in liver tissue. BALBC female rats (21) were divided as the group fed with standard chow (SC), the group fed with a ketogenic diet (KD) and the group fed with western diet (WD). The rats were fed with tap water and a rat diet specially prepared according to the determined diets for 4 weeks. Liver tissue oxidative damage, proliferation and vasculogenesis were evaluated using spectrophotometric and immunohistopathological methods. At the end of the experiment, it was found that the highest weight gain was in the WD group and the least weight gain was in the KD group. The mean body weight of the WD group was statistically significantly higher compared to the SC and KD groups (p&lt;0.05). MDA levels were found to be lower in the KD group compared to the SC and WD groups. GSH and CAT levels were higher in the KD group compared to the SC and WD groups. In IHC evaluation results, it was seen that Ki-67 percentage in the KD group increased compared to the WD and SC groups (p = 0.000), VEGF was close to each other in all three groups and there was no significant difference in the comparisons between groups (p&gt;0.05). These results revealed that ketogenic diet prevents tissue damage by decreasing lipid peroxidation in liver tissue as well as inducing cellular proliferation and vasculogenesis.

Diet-Dependent Changes of the DNA Methylome Using a Göttingen Minipig Model for Obesity.

Objective: Environmental factors can influence obesity by epigenetic mechanisms. The aim of this study was to investigate obesity-related epigenetic changes and the potential for reversal of these changes in the liver of Göttingen minipigs subjected to diet interventions.Methods: High-throughput liquid hybridization capture-based bisulfite sequencing (LHC-BS) was used to quantify the methylation status of gene promotor regions in liver tissue in three groups of male castrated Göttingen minipigs: a standard chow group (SD, N = 7); a group fed high fat/fructose/cholesterol diet (FFC, N = 10) and a group fed high fat/fructose/cholesterol diet during 7 months and reversed to standard diet for 6 months (FFC/SD, N = 12). Expression profiling by qPCR of selected metabolically relevant genes was performed in liver tissue from all pigs.Results: The pigs in the FFC diet group became morbidly obese. The FFC/SD diet did not result in a complete reversal of the body weight to the same weight as in the SD group, but it resulted in reversal of all lipid related metabolic parameters. Here we identified widespread differences in the patterning of cytosine methylation of promoters between the different feeding groups. By combining detection of differentially methylated genes with a rank-based hypergeometric overlap algorithm, we identified 160 genes showing differential methylation in corresponding promoter regions in the FFC diet group when comparing with both the SD and FFC/SD groups. As expected, this differential methylation under FFC diet intervention induced de-regulation of several metabolically-related genes involved in lipid/cholesterol metabolism, inflammatory response and fibrosis generation. Moreover, five genes, of which one is a fibrosis-related gene (MMP9), were still perturbed after diet reversion.Conclusion: Our findings highlight the potential of exploring diet-epigenome interactions for treatment of obesity.

Influence of Omega-3 Fatty Acid-Rich Fish Oils on Hyperlipidemia: Effect of Eel, Sardine, Trout, and Cod Oils on Hyperlipidemic Mice.

Dyslipidemia is one of the most important cardiovascular disease (CVD) risk factors. Polyunsaturated fatty acids (FAs), and especially omega-3 FAs, could significantly contribute to the management of dyslipidemia and the prevention of CVD. The anti-hyperlipidemic effect of selected fish oils (eel, sardine, trout, cod liver) was comparatively evaluated in a high fat diet (HFD)-fed mouse model. At the end of 30 days on the HFD, all animals were hyperlipidemic and were switched to a diet consisting of 90% standard rodent chow plus 10% of oil from eel, sardine, cod liver, or trout. At the end of 60 days on these diets, blood glucose, total blood cholesterol, triglycerides (TGs), and high density lipoprotein (HDL) were quantitated. All diets, except sardine and standard rodent chow, showed statistically significant decreases in blood glucose from day 30 to 90. Total blood cholesterol decreased in all diets except the HFD group, which was continued on this diet until the end of the study. Eel and cod liver oil diets showed significant decreases in TGs. All dietary groups showed a decrease in HDL, but only the trout and standard chow groups exhibited statistically significant decreases. The fish oils tested here for effects on hyperlipidemia vary in per cent of omega-3 FAs and omega-6/-3 FA ratios as determined by gas chromatography Overall, smoked eel was the best source of omega-3 FA, with a balance of omega-6 FA, that ameliorated HFD-induced mixed hyperlipidemia.

Maternal High-Fat Diet Leads to Non-alcoholic Fatty Liver Disease Through Upregulating Hepatic SCD1 Expression in Neonate Rats.

Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of liver disease in children, with evidence that the maternal diet and the early life nutritional environment are potential risk for such disease. This study was aimed to investigate the effects of maternal high-fat diet (HFD) on the occurrence of NAFLD in offspring rats and the underlying mechanisms. In this study, the incidence of NAFLD was compared in F1 offspring rats between the maternal HFD group and standard chow (SC) group. In addition, the expression levels of inflammatory cytokines in the placenta, in the umbilical cord blood, and in the livers of neonate offsprings were compared between two groups. HepG2 cells were treated with recombinant IL6 (rIL6) to assess stearoyl-CoA desaturase 1 (SCD1) expression and lipid synthesis in an inflammatory condition. Lipid accumulation was assayed in both SCD1 overexpression and interference HepG2 cells as well as in neonatal rats. Our results showed that HFD exposure before and throughout the pregnancy induced the elevated hepatic TG content of F1 neonates. The levels of inflammatory cytokines in the placenta, umbilical cord blood, and the livers of HFD F1 neonates were significantly higher than those of the SC group. In addition, rIL6 treatment led to TG accumulation accompanied by the upregulation of SCD1 in HepG2 cell lines. Overexpression of SCD1 led to the accumulation of TG contents in HepG2 cells, whereas Scd1 knockdown attenuated the effects of rIL6 treatment. Overexpression of SCD1 in F1 neonatal rats led to hepatic lipid accumulation. Our study indicated that maternal HFD led to intrauterine inflammation, which subsequently caused transgenerationally abnormal hepatic lipid metabolism of F1 neonates. This modulation might be mediated by upregulating SCD1 expression in hepatic cells.

Polyphenols-Rich Fruit (Euterpe edulis Mart.) Prevents Peripheral Inflammatory Pathway Activation by the Short-Term High-Fat Diet.

Juçara berry is a potential inflammatory modulator, rich in dietary fiber, fatty acids, and anthocyanins. Considering this, we evaluated the high-fat diet (HFD) intake supplemented with different doses of freeze-dried juçara pulp on the TLR4 pathway. Twenty-seven male Wistar rats with ad libitum access to food and water were divided into four experimental groups: control standard chow group (C); high-fat diet control group (HFC); high-fat diet juçara 0.25% group (HFJ0.25%); and high-fat diet juçara 0.5% group (HFJ0.5%). The inflammatory parameters were analyzed by ELISA and Western blotting in liver and retroperitoneal adipose tissue (RET). The HFJ0.25% group had the energy intake, aspartate transaminase (AST) levels, and liver triacylglycerol accumulation reduced; also, the tumor necrosis factor α (TNF-α) and TNF receptor-associated factor 6 (TRAF6) expression in RET were reduced. However, there were no changes in other protein expressions in liver and adipose tissue. Adiposity and pNFκBp50 had a positive correlation in HFC and HFJ0.5%, but not in the C group and HFJ0.25%. The necrosis hepatic score did not change with treatment; however, the serum (AST) levels and the hepatic triacylglycerol were increased in HFC and HFJ0.5%. These results demonstrated that one week of HFD intake triggered pro-inflammatory mechanisms and liver injury. Additionally, 0.25% juçara prevented inflammatory pathway activation, body weight gain, and liver damage

Chronic moderate alcohol consumption relieves high-fat high-cholesterol diet-induced liver fibrosis in a rat model.

Nonalcoholic fatty liver disease is a worldwide health issue and chronic alcohol consumption may have different effects on this disease. This study explored the role of chronic moderate alcohol consumption on high-fat high-cholesterol (HFHC) diet-induced liver fibrosis in a rodent model. Male Sprague-Dawley rats were divided into five groups: standard chow group, standard chow plus Er Guo Tou (EGT, a Chinese spirit made from fermented cereals) group, HFHC group, HFHC plus EGT group, and HFHC plus pure ethanol (EtOH) group. Rats were fed standard chow or HFHC chow for 12weeks. EGT or pure ethanol was administrated at a daily dose of 4g/kg body weight via intra-gastric gavage from week 4. At the end of week 12, hematoxylin and eosin staining, Sirius red and immunohistochemistry of liver sections were examined. The hepatic expression of F4/80, TNF-α, IL-1β, IL-6, CXCL1, CXCL2, α-SMA, Collagen, TGF-β, MMP2, MMP9, and TIMP1 was calculated. Both moderate EGT and pure ethanol did not increase plasma endotoxin in the portal vein comparing with the FHFC group. EGT and pure ethanol did not improve hepatic inflammation, but ameliorated liver fibrosis in histology. Moderate EGT and pure ethanol ameliorated HFHC diet-induced activation of Kupffer cells and hepatic stellate cells. In conclusion, chronic moderate EGT and pure ethanol could ameliorate HFHC diet-induced liver fibrosis.

Impact of Exercise Training and Enalapril, either alone or in Combination, on White Adipose Tissue Renin‐Angiotensin System in a Diet‐Induced Obesity Model

The renin–angiotensin system (RAS) has emerged as a regulator of metabolic homeostasis with angiotensin (Ang) II acting as an ‘adiposity signal’ and Ang 1–7 promoting counter‐regulatory effects. Chronic endurance training profoundly affects white adipose tissue (WAT) metabolism and causes remarkable changes in its RAS. In this context, the aim of this study was to evaluate the effects of endurance training and the angiotensin converting enzyme (ACE) inhibitor enalapril on WAT RAS and adiposity in a diet‐induced obesity mouse model. C57BL/6 mice were fed either standard chow (SC) or high‐fat (HF) diets for 16 weeks. After 8 weeks, HF‐fed animals were divided into 4 groups (n=8): HF, HF + Enalapril (HF‐E), HF + training (HF‐T) and HF + Enalapril + training (HF‐ET). Endurance training consisted of 60 min/day, 5 days/week moderate‐intensity treadmill running. Enalapril (10 mg/kg/day) was administered in the diet. Both interventions were maintained for 8 weeks. We assessed body mass (BM) and composition by DEXA, systolic blood pressure (SBP), lipid and inflammatory profile, circulating irisin, and WAT histology. WAT RAS components were measured by HPLC‐DAD. In comparison to SC animals, BM significantly increased in HF animals, but not in mice subjected to HF‐E and HF‐T interventions, whereas BM was significantly reduced in the HF‐ET group. SBP, adipocyte hypertrophy, adiposity index, and percentage body fat were all elated in HF compared to SC mice; however, the interventions prevented these elevations. Circulating cholesterol levels increased in the HF and HF‐E groups, whereas in the HF‐T and HF‐ET this variable did not differ from the SC group. IL‐6 and TNF‐α were significantly elevated by HF diet, and all interventions reduced circulating levels of these inflammatory markers to values similar to those of SC mice. Plasma irisin was increased only in endurance‐trained mice. WAT Ang II concentration was higher in the HF than SC group and all interventions reduced it. The HF‐ET group showed the lowest Ang II concentration compared to the other groups. The Ang II/Ang 1–7 WAT ratio in HF‐E and HF‐T was similar to the SC mice, whereas in the HF‐ET this ratio was significantly lower than SC and HF groups. The results of this study suggest that enalapril combined with endurance training has better results than either treatment alone in reducing adiposity and shifting the balance of RAS toward the Ang 1–7 counter‐regulatory axis in WAT. Furthermore, both enalapril and endurance training improved the inflammatory profile, although only endurance training reduced cholesterol and increased irisin levels. These results suggest that targeting WAT RAS could be a new therapeutic approach to treat obesity‐related dysfunctional metabolic alteration.Support or Funding InformationFAPERJ, CAPES and CNPqThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The role of glucokinase and insulin receptor substrate-2 in the proliferation of pancreatic beta cells induced by short-term high-fat diet feeding in mice

ObjectiveWe investigated whether glucokinase and insulin receptor substrate-2 were required for beta cell proliferation induced by short-term high-fat (HF) diet feeding, as has been shown for long-term HF diet. MethodsEight-week-old C57BL/6J mice were exposed to either a standard chow (SC) or HF diet. After 1 week on the diet, histopathological beta cell proliferation and gene expression in isolated islets were examined. Additionally, 8-week-old beta cell-specific glucokinase haploinsufficient (Gck+/−) and Irs2 knockout (Irs2−/−) mice were exposed to either an SC or HF diet. ResultsImmunohistochemical analysis revealed that short-term HF diet feeding resulted in a significant increase in BrdU incorporation rate compared with SC consumption in wild-type mice. Western blot analysis demonstrated that Irs2 expression levels did not differ between the two diets. Moreover, there was a significant increase in the BrdU incorporation rate in the HF diet group compared with the SC group in both Gck+/− and Irs2−/− mice. Gene expression profiling of isolated islets from mice fed an HF diet for 1 week revealed that the expression levels of downstream genes of Foxm1 were coordinately upregulated. One week of HF diet feeding stimulated beta cell proliferation with Foxm1 upregulation in 48-week-old mice as well as in 8-week-old. ConclusionsThe mechanism of pancreatic beta cell proliferation induced by short-term HF diet feeding in mice could involve a glucokinase- and Irs2-independent pathway. Our results suggest that the pathways that induce beta cell proliferation in response to short-term HF diet feeding may differ from those in response to sustained HF diet feeding.

Oral insulin improves metabolic parameters in high fat diet fed rats.

The gut has shown to have a pivotal role on the pathophysiology of metabolic disease. Food stimulation of distal intestinal segments promotes enterohormones secretion influencing insulin metabolism. In diabetic rats, oral insulin has potential to change intestinal epithelium behavior. This macromolecule promotes positive effects on laboratorial metabolic parameters and decreases diabetic intestinal hypertrophy. This study aims to test if oral insulin can influence metabolic parameters and intestinal weight in obese non-diabetic rats. Twelve weeks old Wistar rats were divided in 3 groups: control (CTRL) standard chow group; high fat diet low carbohydrates group (HFD) and HFD plus daily oral 20U insulin gavage (HFD+INS). Weight and food consumption were weekly obtained. After eight weeks, fasting blood samples were collected for laboratorial analysis. After euthanasia gut samples were isolated. Rat oral insulin treatment decreased body weight gain (p<0,001), fasting glucose and triglycerides serum levels (p<0,05) an increased intestinal weight of distal ileum (P<0,05). Animal submitted to high fat diet presented higher levels of HOMA-IR although significant difference to CT was not achieved. HOMA-beta were significantly higher (p<0.05) in HFD+INS. Visceral fat was 10% lower in HFD+INS but the difference was not significant. In non-diabetic obese rats, oral insulin improves metabolic malfunction associated to rescue of beta-cell activity.

Short Exposure to a High-Sucrose Diet and the First ‘Hit' of Nonalcoholic Fatty Liver Disease in Mice

High-sucrose and high-fat diets induce deregulation in the metabolism of lipids and carbohydrates. This study aimed to detect the initial consequences on lipogenesis, gluconeogenesis and insulin signaling in the livers of rodents fed high-fat and/or high-sucrose diets for a short period of time. Male mice received a standard chow (SC), high-fat (HF), high-sucrose (HSu) or high-fat, high-sucrose (HFHSu) diet for 4 weeks. At euthanasia, blood was collected and the liver was removed for histomorphometrical and molecular analysis. The HF, HSu and HFHSu groups presented glucose intolerance, hepatomegaly, liver steatosis and lipid profile alteration when compared to the SC group (p < 0.0005). Additionally, there was an elevation in protein levels involved in lipogenesis (SREBP-1c), gluconeogenesis (PEPCK and G6Pase) and insulin signaling (IRS-1 and Akt) in the livers from the experimental groups compared to the SC group (p < 0.0005). Thus, we conclude that a short-term HF and/or HSu diet promotes glucose intolerance and liver damage in adult male mice. Surprisingly, the short exposure to excess sucrose in the diet promoted glucose intolerance and liver damage even in the absence of an increase in body mass or changes in serum insulin, cholesterol and triacylglycerol levels.

Diets rich in saturated and polyunsaturated fatty acids induce morphological alterations in the rat ventral prostate.

AimTo evaluate the influence of dietary lipid quality on the body mass, carbohydrate metabolism and morphology of the rat ventral prostate.Materials and MethodsWistar rats were divided into four groups: SC (standard chow), HF-S (high-fat diet rich in saturated fatty acids), HF-P (high-fat diet rich in polyunsaturated fatty acids) and HF-SP (high-fat diet rich in saturated and polyunsaturated fatty acids). We analyzed body mass, fat mass deposits, plasma blood, insulin resistance and the ventral prostate structure.ResultsGroups that received high-fat diets were heavier and presented larger fat deposits than SC group. The HF-S and HF-SP groups had higher glucose, insulin and total cholesterol serum levels and insulin resistance compared with the SC. The acinar area, epithelium height and area density of the lumen were higher in the HF-SP than in the other groups. The epithelium area density and epithelial cell proliferation were greater in the HF-P and HF-SP than in the SC group. All of the groups that received high-fat diets had greater area density of the stroma, area density of smooth muscle cells and stromal cell proliferation compared with the SC group.ConclusionDiets rich in saturated and/or polyunsaturated fatty acids induced overweight. Independently of insulin resistance, polyunsaturated fatty acids increased prostate stromal and epithelial cell proliferation. Saturated fatty acids influenced only stromal cellular proliferation. These structural and morphometric alterations may be considered risk factors for the development of adverse remodeling process in the rat ventral prostate.

Development and evaluation of a high-fat/high-fructose diet-induced nonalcoholic steatohepatitis mouse model

To develop and evaluate a mouse model of nonalcoholic steatohepatitis (NASH) induced by a high-fat and high-fructose (HFHFr) diet. Six-week-old C3H mice were randomly divided into groups for HFHFr diet experimental modeling, high fat-only (HF) diet controls, high fructose-only (HFr) diet controls, and standard chow (SC) diet controls. The standard HFHFr diet was modified so that it consisted of 76.5% standard chow, 12% lard, 1% cholesterol, 5% egg yolk powder, 5% whole milk powder, and 0.5% sodium cholate, along with 20% fructose drinking water. At the end of experimental weeks 4, 8, and 16, measurements were taken for the NASH-related parameters of body mass, serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), lipid profile, and wet liver weight (upon sacrifice). In addition, histological changes in the liver were evaluated by hematoxylin-eosin (HE) and oil red O staining. The significance of differences between groups was assessed by statistical analysis, using the of t-test, Wilcoxon rank sum test, x2 test, F test or Fisher's test as appropriate. As compared to the mice in the SC group at the corresponding time points, the mice in the HFHFr and HF groups showed significantly higher body mass and wet liver weight, as well as more extensive and robust lipid disposition in hepatic tissues as evidenced by oil red O staining. However, HE staining indicated that the HFHFr and HF groups had different degrees of macrosteatosis accompanied with intralobular inflammatory foci, with the former showing more remarkable NASH-related histological changes. Analysis at the end of week 16 showed that about 80% of the mice in the HFHFr group had developed NASH [nonalcoholic fatty liver disease (NAFLD) activity score (NAS): less than 5]. The levels of low-and high-density lipoprotein (LDL and HDL) cholesterol, as well as the levels of ALT and AST, were increased from the end of week 4 to the end of week 8 for the HFHFr and HF groups. At the end of week 16, the two groups differed in the extent of increase in total cholesterol and LDL and HDL cholesterol, with only the HFHFr group showing statistically significant changes. Specifically, at the end of week 16, the HFHFr group showed ALT levels of 108.5 +/- 93.34 U/L (F=5.099, P =0.005 vs. HF group: 44.30 +/- 35.71 U/L, HFr group: 46.70 +/- 17.95 U/L, SC group: 24.70 +/- 6.57 U/L), AST levels of 316.30 +/- 208.98 U/L (F=6.654, P=0.001 vs. HF: 132.12 +/- 75.43 U/L, HFr: 143.30 +/- 38.53 U/L, SC: 122.60 +/- 12.76 U/L), total cholesterol levels of 5.18 +/- 0.58 mmol/L (F=72: 470, P =0.000 vs. HF: 3.94 +/- 0.75 mmol/L, HFr: 2.30 +/- 0.50 mmol/L, SC: 2.02 +/- 0.24 mmol/L), HDL cholesterol levels of 3.05 +/- 0.49 mmol/L (F=25.413, P =0.000 vs. HF: 2.65 +/- 0.54 mmol/L HFr: 1.77 +/- 0.47 mmol/L, SC: 1.58 +/- 0.16 mmol/L), LDL cholesterol levels of 1.11 +/- 0.23 mmol/L (F =83.297, P =0.000 vs. HF: 0.72 +/- 0.17 mmol/L, HFr: 0.27 +/- 0.04 mmol/L, SC: 0.20 +/- 0.05 mmol/ L). The present study suggests that a mouse model of NASH can be successfully induced by a 16-week modified HFHFr diet.

The selective orexin receptor 1 antagonist ACT-335827 in a rat model of diet-induced obesity associated with metabolic syndrome

The orexin system regulates feeding, nutrient metabolism and energy homeostasis. Acute pharmacological blockade of orexin receptor 1 (OXR-1) in rodents induces satiety and reduces normal and palatable food intake. Genetic OXR-1 deletion in mice improves hyperglycemia under high-fat (HF) diet conditions. Here we investigated the effects of chronic treatment with the novel selective OXR-1 antagonist ACT-335827 in a rat model of diet-induced obesity (DIO) associated with metabolic syndrome (MetS). Rats were fed either standard chow (SC) or a cafeteria (CAF) diet comprised of intermittent human snacks and a constant free choice between a HF/sweet (HF/S) diet and SC for 13 weeks. Thereafter the SC group was treated with vehicle (for 4 weeks) and the CAF group was divided into a vehicle and an ACT-335827 treatment group. Energy and water intake, food preference, and indicators of MetS (abdominal obesity, glucose homeostasis, plasma lipids, and blood pressure) were monitored. Hippocampus-dependent memory, which can be impaired by DIO, was assessed. CAF diet fed rats treated with ACT-335827 consumed less of the HF/S diet and more of the SC, but did not change their snack or total kcal intake compared to vehicle-treated rats. ACT-335827 increased water intake and the high-density lipoprotein associated cholesterol proportion of total circulating cholesterol. ACT-335827 slightly increased body weight gain (4% vs. controls) and feed efficiency in the absence of hyperphagia. These effects were not associated with significant changes in the elevated fasting glucose and triglyceride (TG) plasma levels, glucose intolerance, elevated blood pressure, and adiposity due to CAF diet consumption. Neither CAF diet consumption alone nor ACT-335827 affected memory. In conclusion, the main metabolic characteristics associated with DIO and MetS in rats remained unaffected by chronic ACT-335827 treatment, suggesting that pharmacological OXR-1 blockade has minimal impact in this model.

Maternal Vitamin D Deficiency Delays Glomerular Maturity in F1 and F2 Offspring

BackgroundThere is a high prevalence of vitamin D insufficiency in women of reproductive age.MethodsThis work studied the first two generations of offspring (F1 and F2) of Swiss mice from mothers fed one of two diets: SC (standard chow) or VitD- (vitamin D-deficient). Functional and developmental kidney measurements were taken.ResultsThe first two generations of the VitD- group had higher blood pressure at 6 months of age than the offspring of the SC group as well as an increase in renin and AT1r expression. However, at all ages, both F1 and F2 VitD- mice had shorter glomerular diameters, and diet played a significant role in the total variation. Both the F1 and F2 generations of the VitD- group had more immature glomeruli than offspring from the SC group. Immature glomeruli begin to disappear at 10 days, but at this age, F1-VitD- mice had more immature and mature glomeruli than F1-SC mice. At 6 months of age, F1-VitD- mice exhibited more glomeruli, while F2-VitD- mice exhibited the same number of glomeruli as F2-SC mice, but fewer glomeruli compared to the F1-VitD group. Both diet and generation account for the total variation in the number of glomeruli. Decreases in urine output and podocin expression and increases in urea and creatinine in the urine were observed in F1 offspring.ConclusionThese findings demonstrate that maternal vitamin D deficiency accompanies changes in the renal expression of important factors that may retard the maturation of glomeruli by extending the period of nephrogenesis.

Maternal high-fat diet is associated with altered pancreatic remodelling in mice offspring

To investigate whether a maternal high-fat diet (HF) during pregnancy and/or suckling periods predisposes adult C57BL/6 mice offspring to morphological pancreatic modifications. Male pups were divided into 5 groups: SC (standard chow)-from dams fed SC during gestation and lactation, maintaining an SC diet from postweaning to adulthood; G-from dams fed HF diets during gestation; L-from dams fed HF diets during lactation; GL-from dams fed HF diets during gestation and lactation; and GL/HF-from dams fed HF diets during gestation and lactation, maintaining an HF diet from postweaning to adulthood. We analysed body mass (BM), plasma insulin, pancreas and adipose tissue structures. During the entire experiment, the SC group had the lowest BM. However, GL/HF offspring were heavier than the other groups. This weight gain was also accompanied by adipocyte hypertrophy. At 3 months, G offspring showed an increased insulin levels and impairment in carbohydrates metabolism. Furthermore, pancreatic islets were hypertrophied in G, GL and GL/HF offspring in comparison with SC offspring. HF diet administration during the gestation period is more harmful than during the lactation period, exerting deleterious effects on pancreatic morphology in addition to larger fat deposits in adult mice offspring.

Effects of early life interventions and palatable diet on anxiety and on oxidative stress in young rats

Early life events can change biochemical, endocrine and behavioral aspects throughout the life of an animal. Since there is a strong relationship between stress, neonatal handling and feeding behavior, the aim of this study was to investigate the effects of these three factors on behavioral parameters (anxiety and locomotion), oxidative stress in brain structures (prefrontal cortex and hippocampus) and on plasma glucose. Nests of Wistar rats were handled (10min/day), or not (control groups), on days 1–10 after birth. Males from these groups were divided into 4 subgroups: 1) stressed by isolation in childhood (pre-puberty) and with access to a highly palatable diet 2) stressed by isolation and receiving standard lab chow 3) not isolated and receiving a highly palatable diet and 4) not isolated and receiving standard chow. The animals were kept under these conditions for 7days. Rats receiving the highly palatable diet consumed more food, more calories, gained more weight and had a higher plasma glucose level, but had a lower caloric efficiency than the standard chow groups. Both handling and palatable diet were able to increase food consumption on the first day of isolation. Isolation stress had an anxiogenic effect in the plus maze, which was counteracted by handling. Palatable diet increased time spent in the central area of the open field apparatus and in the open arms of the elevated plus maze, showing an anxiolytic effect. The use of both these conditions, however, does not appear to bring additional protection against the effects of stress during this particular period of life, i.e. pre-puberty. In the prefrontal cortex, handling reduced thiol content and appears to imbalance the antioxidant enzymes system, which is counteracted by a palatable diet. Hippocampus seems to be more sensitive than the prefrontal cortex to early interventions, especially to the highly palatable diet, and both handling and diet appear to imbalance the antioxidant enzyme system. Thus, measurements of antioxidant enzymes activities indicate that handling may endanger some brain structures and that the palatable diet was able to prevent some handling effects on antioxidant enzymes, depending on the brain structure.