scholarly journals Deletion of prolyl carboxypeptidase attenuates the metabolic effects of diet-induced obesity

2012 ◽  
Vol 302 (12) ◽  
pp. E1502-E1510 ◽  
Author(s):  
Jin Kwon Jeong ◽  
Gyorgyi Szabo ◽  
Giuseppina Mattace Raso ◽  
Rosaria Meli ◽  
Sabrina Diano
Keyword(s):  
Liver Weight ◽  
Metabolic Parameters ◽  
Metabolic Effects ◽  
Chow Diet ◽  
Mrna Levels ◽  
Wild Type ◽  
Glucose Levels ◽  
Melanocyte Stimulating Hormone ◽  
Diet Induced Obesity ◽  
Standard Chow Diet

α-Melanocyte-stimulating hormone (α-MSH) is a critical regulator of energy metabolism. Prolyl carboxypeptidase (PRCP) is an enzyme responsible for its degradation and inactivation. PRCP-null mice ( PRCP gt/gt) showed elevated levels of brain α-MSH, reduced food intake, and a leaner phenotype compared with wild-type controls. In addition, they were protected against diet-induced obesity. Here, we show that PRCP gt/gt animals have improved metabolic parameters compared with wild-type controls under a standard chow diet (SD) as well as on a high-fat diet (HFD). Similarly to when they are exposed to SD, PRCP gt/gt mice exposed to HFD for 13 wk showed a leaner phenotype due to decreased fat mass, increased energy expenditure, and locomotor activity. They also showed improved insulin sensitivity and glucose tolerance compared with WT controls and a significant reduction in fasting glucose levels. These improvements occured before changes in body weight and composition were evident, suggesting that the beneficial effect of PRCP ablation is independent of the adiposity levels. In support of a reduced gluconeogenesis, liver PEPCK and G-6-Pase mRNA levels were reduced significantly in PRCPgt/gt compared with WT mice. A significant decrease in liver weight and hepatic triglycerides were also observed in PRCP gt/gt compared with WT mice. Altogether, our data suggest that PRCP is an important regulator of energy and glucose homeostasis since its deletion significantly improves metabolic parameters in mice exposed to both SD and HFD.

scholarly journals Eicosapentaenoic Acid Increases Browning Markers in Subcutaneous Adipose Tissue and Primary Adipocytes from Wild Type and UCP-1 Deficient Mice (P15-007-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Shasika Jayarathne ◽  
Mandana Pahlavani ◽  
Latha Ramalingam ◽  
Shane Scoggin ◽  
Naima Moustaid-Moussa
Keyword(s):  
Adipose Tissue ◽  
Eicosapentaenoic Acid ◽  
Subcutaneous Adipose Tissue ◽  
Uncoupling Protein ◽  
Fibroblast Growth Factor 21 ◽  
Chow Diet ◽  
Mrna Levels ◽  
Wild Type ◽  
Brown Adipose ◽  
Subcutaneous Adipose

Abstract Objectives Brown adipose tissue (BAT) regulates energy balance through thermogenesis, in part via uncoupling protein -1 (UCP-1). White adipose tissue (WAT), namely subcutaneous adipose tissue (SAT) can convert to a beige/brite adipose tissue phenotype (browning) under thermogenic conditions such as cold. We previously reported that eicosapentaenoic acid (EPA) reduced obesity and glucose intolerance, and increased UCP-1 in BAT of B6 mice at ambient temperature (22°C); and these effects were attenuated at thermoneutral environment (28–30°C). We hypothesized that EPA exerts anti-obesity effects on SAT, including increased browning, adipocyte hypotrophy; and these effects require UCP-1. Methods Six-week-old B6 wild type (WT) and UCP-1 knock-out (KO) male mice were maintained at thermoneutral environment and fed high fat diet (HF) with or without 36 g/kg of AlaskOmega EPA-enriched fish oil (800 mg/g) for 14 weeks; and SAT was collected for histological, gene and protein analyses. SAT was also prepared from chow diet-fed WT and KO mice at ambient environment to prepare stroma vascular cells, which were differentiated into adipocytes, treated with 100uM EPA for 48 hours then harvested for mRNA and protein analyses. Results KO mice fed HF diets had the highest body weight (P < 0.05) among all groups. EPA reduced fat cell size in both WT and KO mice fed the EPA diet. mRNA levels of fibroblast growth factor-21 (FGF-21) were higher in SAT of WT mice fed EPA compared to WT mice fed HF (P < 0.05), with no differences between the KO genotype. KO mice fed HF diets had lower levels of UCP-3 in SAT compared to WT mice fed HF (P < 0.05), which was rescued only in the KO mice fed EPA (P < 0.05). UCP-1 protein levels were very low in SAT tissues, and UCP-2 mRNA levels were similar across all groups in SAT. Interestingly, EPA significantly (P < 0.05) increased mRNA expression of UCP-2, UCP-3 and FGF21 in differentiated SAT adipocytes from both WT and KO compared to control. Furthermore, UCP-1 mRNA levels were significantly higher in WT adipocytes treated with EPA, compared to non-treated cells (P < 0.05). Additional mechanistic studies are currently underway to further dissect adipose depot differences in EPA effects in WT vs. KO mice. Conclusions Our data suggest that EPA increases SAT browning, independently of UCP-1. Funding Sources NIH/NCCIH.

LDL receptor but not apolipoprotein E deficiency increases diet-induced obesity and diabetes in mice

2002 ◽  
Vol 282 (1) ◽  
pp. E207-E214 ◽  
Author(s):  
Sandra A. Schreyer ◽  
Cynthia Vick ◽  
Theodore C. Lystig ◽  
Paul Mystkowski ◽  
Renée C. LeBoeuf
Keyword(s):  
Apolipoprotein E ◽  
Low Density Lipoprotein ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Wild Type ◽  
Glucose Levels ◽  
Diet Induced Obesity ◽  
Obesity And Diabetes ◽  
Glucose And Lipid Homeostasis

The aim of this study was to determine whether phenotypes associated with type 2 diabetes are altered in dyslipidemic obese mice. C57BL/6 wild-type, low-density lipoprotein (LDL) receptor-deficient (LDLR−/−), and apolipoprotein E-deficient (apoE−/−) mice were fed a high-fat, high-carbohydrate diet (diabetogenic diet), and the development of obesity, diabetes, and hypertriglyceridemia was examined. Wild-type mice became obese and developed hyperglycemia, but not hypertriglyceridemia, in response to this diet. LDLR−/− mice fed the diabetogenic diet became more obese than wild-type mice and developed severe hypertriglyceridemia and hyperleptinemia. Surprisingly, glucose levels were only modestly higher and insulin levels and insulin-to-glucose ratios were not strikingly different from those of wild-type mice. In contrast, diabetogenic diet-fed apoE−/− mice were resistant to changes in glucose and lipid homeostasis despite becoming obese. These data suggest that modifications in lipoprotein profiles associated with loss of the LDL receptor or apoE function have profound and unique consequences on susceptibility to diet-induced obesity and type 2 diabetic phenotypes.

scholarly journals Sex Differences in the Metabolic Effects of Testosterone in Sheep

Endocrinology ◽  
2012 ◽  
Vol 153 (1) ◽  
pp. 123-131 ◽  
Author(s):  
Scott D. Clarke ◽  
Iain J. Clarke ◽  
Alexandra Rao ◽  
Michael A. Cowley ◽  
Belinda A. Henry
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Uncoupling Protein ◽  
Specific Effect ◽  
Metabolic Effects ◽  
Mrna Levels ◽  
Nonesterified Fatty Acids ◽  
Glucose Levels ◽  
Amp Activated Protein Kinase ◽  
The Brain

Adiposity is regulated in a sexually divergent manner. This is partly due to sex steroids, but the differential effects of androgens in males and females are unclear. We investigated effects of testosterone on energy balance in castrated male (n = 6) and female sheep (n = 4), which received 3 × 200 mg testosterone implants for 2 wk or blank implants (controls). Temperature probes were implanted into retroperitoneal fat and skeletal muscle. Blood samples were taken to measure metabolites and insulin. In males, muscle and fat biopsies were collected to measure uncoupling protein (UCP) mRNA and phosphorylation of AMP-activated protein kinase and Akt. Testosterone did not change food intake in either sex. Temperature in muscle was higher in males than females, and testosterone reduced heat production in males only. In fat, however, temperature was higher in the castrate males compared with females, and there was no effect of testosterone treatment in either sex. Preprandial glucose levels were lower, but nonesterified fatty acids were higher in females compared with males, irrespective of testosterone. In males, the onset of feeding increased UCP1 and UCP3 mRNA levels in skeletal muscle, without an effect of testosterone. During feeding, testosterone reduced glucose levels in males only but did not alter the phosphorylation of AMP-activated protein kinase or Akt in muscle. Thus, testosterone maintains lower muscle and fat temperatures in males but not females. The mechanism underlying this sex-specific effect of testosterone is unknown but may be due to sexual differentiation of the brain centers controlling energy expenditure.

scholarly journals Pioglitazone attenuates hepatic inflammation and fibrosis in phosphatidylethanolamine N-methyltransferase-deficient mice

2016 ◽  
Vol 310 (7) ◽  
pp. G526-G538 ◽  
Author(s):  
Jelske N. van der Veen ◽  
Susanne Lingrell ◽  
Xia Gao ◽  
Ariel D. Quiroga ◽  
Abhijit Takawale ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Transforming Growth Factor ◽  
Body Weight Gain ◽  
Smooth Muscle Actin ◽  
Transforming Growth Factor Β ◽  
Liver Weight ◽  
Mrna Levels ◽  
Nonalcoholic Fatty Liver ◽  
Diet Induced Obesity ◽  
Important Enzyme

Phosphatidylethanolamine N-methyltransferase (PEMT) is an important enzyme in hepatic phosphatidylcholine (PC) biosynthesis. Pemt−/− mice are protected against high-fat diet (HFD)-induced obesity and insulin resistance; however, these mice develop nonalcoholic fatty liver disease (NAFLD). We hypothesized that peroxisomal proliferator-activated receptor-γ (PPARγ) activation by pioglitazone might stimulate adipocyte proliferation, thereby directing lipids from the liver toward white adipose tissue. Pioglitazone might also act directly on PPARγ in the liver to improve NAFLD. Pemt+/+ and Pemt−/− mice were fed a HFD with or without pioglitazone (20 mg·kg−1·day−1) for 10 wk. Pemt−/− mice were protected from HFD-induced obesity but developed NAFLD. Treatment with pioglitazone caused an increase in body weight gain in Pemt−/− mice that was mainly due to increased adiposity. Moreover, pioglitazone improved NAFLD in Pemt−/− mice, as indicated by a 35% reduction in liver weight and a 57% decrease in plasma alanine transaminase levels. Livers from HFD-fed Pemt−/− mice were steatotic, inflamed, and fibrotic. Hepatic steatosis was still evident in pioglitazone-treated Pemt−/− mice; however, treatment with pioglitazone reduced hepatic fibrosis, as evidenced by reduced Sirius red staining and lowered mRNA levels of collagen type Iα1 ( Col1a1), tissue inhibitor of metalloproteinases 1 ( Timp1), α-smooth muscle actin ( Acta2), and transforming growth factor-β ( Tgf-β). Similarly, oxidative stress and inflammation were reduced in livers from Pemt−/− mice upon treatment with pioglitazone. Together, these data show that activation of PPARγ in HFD-fed Pemt −/− mice improved liver function, while these mice were still protected against diet-induced obesity and insulin resistance.

scholarly journals Antiobesity Effects of the β-Cell Hormone Amylin in Diet-Induced Obese Rats: Effects on Food Intake, Body Weight, Composition, Energy Expenditure, and Gene Expression

Endocrinology ◽  
2006 ◽  
Vol 147 (12) ◽  
pp. 5855-5864 ◽  
Author(s):  
Jonathan D. Roth ◽  
Heather Hughes ◽  
Eric Kendall ◽  
Alain D. Baron ◽  
Christen M. Anderson
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Energy Expenditure ◽  
Respiratory Quotient ◽  
Metabolic Effects ◽  
Mrna Levels ◽  
Lean Tissue ◽  
Reduced Body ◽  
Diet Induced Obesity ◽  
Cell Hormone

Effects of amylin and pair feeding (PF) on body weight and metabolic parameters were characterized in diet-induced obesity-prone rats. Peripherally administered rat amylin (300 μg/kg·d, 22d) reduced food intake and slowed weight gain: approximately 10% (P &lt; 0.05), similar to PF. Fat loss was 3-fold greater in amylin-treated rats vs. PF (P &lt; 0.05). Whereas PF decreased lean tissue (P &lt; 0.05 vs. vehicle controls; VEH), amylin did not. During wk 1, amylin and PF reduced 24-h respiratory quotient (mean ± se, 0.82 ± 0.0, 0.81 ± 0.0, respectively; P &lt; 0.05) similar to VEH (0.84 ± 0.01). Energy expenditure (EE mean ± se) tended to be reduced by PF (5.67 ± 0.1 kcal/h·kg) and maintained by amylin (5.86 ± 0.1 kcal/h·kg) relative to VEH (5.77 ± 0.0 kcal/h·kg). By wk 3, respiratory quotient no longer differed; however, EE increased with amylin treatment (5.74 ± 0.09 kcal/·kg; P &lt; 0.05) relative to VEH (5.49 ± 0.06) and PF (5.38 ± 0.07 kcal/h·kg). Differences in EE, attributed to differences in lean mass, argued against specific amylin-induced thermogenesis. Weight loss in amylin and pair-fed rats was accompanied by similar increases arcuate neuropeptide Y mRNA (P &lt; 0.05). Amylin treatment, but not PF, increased proopiomelanocortin mRNA levels (P &lt; 0.05 vs. VEH). In a rodent model of obesity, amylin reduced body weight and body fat, with relative preservation of lean tissue, through anorexigenic and specific metabolic effects.

scholarly journals Effects of food pattern change and physical exercise on cafeteria diet-induced obesity in female rats

2012 ◽  
Vol 108 (8) ◽  
pp. 1511-1518 ◽  
Author(s):  
Jéferson F. Goularte ◽  
Maria B. C. Ferreira ◽  
Gilberto L. Sanvitto
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Physical Exercise ◽  
Energy Intake ◽  
Liver Weight ◽  
Cafeteria Diet ◽  
Chow Diet ◽  
Diet Induced Obesity ◽  
Visceral Adipose

Obesity affects a large number of people around the world and appears to be the result of changes in food intake, eating habits and physical activity levels. Changes in dietary patterns and physical exercise are therefore strongly recommended to treat obesity and its complications. The present study tested the hypothesis that obesity and metabolic changes produced by a cafeteria diet can be prevented with dietary changes and/or physical exercise. A total of fifty-six female Wistar rats underwent one of five treatments: chow diet; cafeteria diet; cafeteria diet followed by a chow diet; cafeteria diet plus exercise; cafeteria diet followed by a chow diet plus exercise. The duration of the experiment was 34 weeks. The cafeteria diet resulted in higher energy intake, weight gain, increased visceral adipose tissue and liver weight, and insulin resistance. The cafeteria diet followed by the chow diet resulted in energy intake, body weight, visceral adipose tissue and liver weight and insulin sensitivity equal to that of the controls. Exercise increased total energy intake at week 34, but produced no changes in the animals' body weight or adipose tissue mass. However, insulin sensitivity in animals subjected to exercise and the diet was similar to that of the controls. The present study found that exposure to palatable food caused obesity and insulin resistance and a diet change was sufficient to prevent cafeteria diet-induced obesity and to maintain insulin sensitivity at normal levels. In addition, exercise resulted in normal insulin sensitivity in obese rats. These results may help to develop new approaches for the treatment of obesity and type 2 diabetes mellitus.

TRPV4 deficiency increases skeletal muscle metabolic capacity and resistance against diet-induced obesity

2012 ◽  
Vol 112 (7) ◽  
pp. 1223-1232 ◽  
Author(s):  
Tatsuya Kusudo ◽  
Zhonghua Wang ◽  
Atsuko Mizuno ◽  
Makoto Suzuki ◽  
Hitoshi Yamashita
Keyword(s):  
Skeletal Muscle ◽  
Energy Metabolism ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Transient Receptor Potential ◽  
Thermal Sensation ◽  
Chow Diet ◽  
Type I ◽  
Wild Type ◽  
Diet Induced Obesity ◽  
Obesity In Mice

Transient receptor potential channel V4 (TRPV4) functions as a nonselective cation channel in various cells and plays physiological roles in osmotic and thermal sensation. However, the function of TRPV4 in energy metabolism is unknown. Here, we report that TRPV4 deficiency results in increased muscle oxidative capacity and resistance to diet-induced obesity in mice. Although no difference in body weight was observed between wild-type and Trpv4−/− mice when fed a standard chow diet, obesity phenotypes induced by a high-fat diet were significantly improved in Trpv4−/− mice, without any change in food intake. Quantitative analysis of mRNA revealed the constitutive upregulation of many genes, including those for transcription factors such as peroxisome proliferator-activated receptor α and for metabolic enzymes such as phosphoenolpyruvate carboxykinase. These upregulated genes were especially prominent in oxidative skeletal muscle, in which the activity of Ca2+-dependent phosphatase calcineurin was elevated, suggesting that other Ca2+ channels function in the skeletal muscle of Trpv4−/− mice. Indeed, gene expressions for TRPC3 and TRPC6 increased in the muscles of Trpv4−/− mice compared with those of wild-type mice. The number of oxidative type I fiber also increased in the mutant muscles following myogenin gene induction. These results strongly suggested that inactivation of Trpv4 induces compensatory increases in TRPC3 and TRPC6 production, and elevation of calcineurin activity, affecting energy metabolism through increased expression of genes involved in fuel oxidation in skeletal muscle and thereby contributing to increased energy expenditure and protection from diet-induced obesity in mice.

scholarly journals ChREBP-Knockout Mice Show Sucrose Intolerance and Fructose Malabsorption

2018 ◽  
Author(s):  
Takehiro Kato ◽  
Katsumi Iizuka ◽  
Ken Takao ◽  
Yukio Horikawa ◽  
Tadahiro Kitamura ◽  
...  
Keyword(s):  
Plasma Glucose ◽  
Knockout Mice ◽  
Gene Deletion ◽  
Body Weight Loss ◽  
Mrna Levels ◽  
Wild Type ◽  
Glucose Levels ◽  
Fructose Malabsorption ◽  
Sucrose Diet ◽  
Alpha Glucosidase

We have previously reported that 60% sucrose diet-fed ChREBP knockout mice (KO) showed body weight loss resulting in lethality. We aimed to elucidate whether sucrose and fructose metabolism are impaired in KO. Wild type mice (WT) and KO were fed a diet containing 30% sucrose with/without 0.08% miglitol, an &alpha;-glucosidase inhibitor, and these effects on phenotypes were tested. Furthermore, we compared metabolic changes of oral and peritoneal fructose injection. Thirty percent sucrose diet feeding did not affect phenotypes in KO. However, miglitol induced lethality in 30% sucrose-fed KO. Thirty percent sucrose plus miglitol diet-fed KO showed increased cecal contents, increased fecal lactate contents, increased growth of lactobacillales and Bifidobacterium and decreased growth of clostridium cluster XIVa. ChREBP gene deletion suppressed the mRNA levels of sucrose and fructose related genes. Next, oral fructose injection did not affect plasma glucose levels and liver fructose contents; however, intestinal sucrose and fructose related mRNA levels were increased only in WT. In contrast, peritoneal fructose injection increased plasma glucose levels in both mice; however, the hepatic fructose content in KO was much higher owing to decreased hepatic Khk mRNA expression. Taken together, KO showed sucrose intolerance and fructose malabsorption owing to decreased gene expression.

Selective breeding for diet-induced obesity and resistance in Sprague-Dawley rats

1997 ◽  
Vol 273 (2) ◽  
pp. R725-R730 ◽  
Author(s):  
B. E. Levin ◽  
A. A. Dunn-Meynell ◽  
B. Balkan ◽  
R. E. Keesey
Keyword(s):  
Glucose Tolerance ◽  
Tolerance Test ◽  
Male Rats ◽  
Oral Glucose ◽  
Chow Diet ◽  
Sprague Dawley ◽  
Fed State ◽  
Glucose Levels ◽  
Diet Induced Obesity ◽  
Sprague Dawley Rats

In outbred Sprague-Dawley rats, about one-half develop diet-induced obesity (DIO) on a diet relatively high in fat and energy (HE diet). The rest are diet resistant (DR), gaining weight and fat at the same rate as chow-fed controls. Here we selectively bred for high (DIO) and low (DR) weight gainers after 2 wk on HE diet. By the F5 generation, both male and female inbred DIO rats gained > 90% more weight than inbred DR rats on HE diets. Even on low-fat chow diet, DIO males were 31% and females were 22% heavier than their respective DR rats. Full metabolic characterization in male rats showed that weight-matched, chow-fed DIO-prone rats had similar energy intakes and feed efficiency [body weight (kg0.75)/energy intake (kcal)] but 44% more carcass fat than comparable DR-prone rats. Their basal plasma insulin and glucose levels in the fed state were 70 and 14% higher, respectively. But, when fasted, DIO-prone oral glucose tolerance results were comparable to DR-prone rats. Chow-fed DIO-prone males also had 42% greater 24-h urine norepinephrine levels than DR-prone males. During 2 wk on HE diet, DIO rats ate 25% more, gained 115% more weight, had 36% more carcass fat, and were 42% more feed efficient than comparable DR rats. Fasted HE diet-fed DIO rats developed frank glucose intolerance during a glucose tolerance test with 55 and 158% greater insulin and glucose areas under the curve, respectively. Thus the DIO and DR traits in the outbred Sprague-Dawley population appear to be due to a polygenic pattern of inheritance.

scholarly journals Strain-specific steroidal control of pituitary function

2007 ◽  
Vol 192 (3) ◽  
pp. 515-525 ◽  
Author(s):  
Sang-Nam Lee ◽  
Bonnie Peng ◽  
Roxane Desjardins ◽  
John E Pintar ◽  
Robert Day ◽  
...  
Keyword(s):  
Genetic Background ◽  
Mouse Strains ◽  
Wild Type ◽  
Glucose Levels ◽  
Melanocyte Stimulating Hormone ◽  
Profound Influence ◽  
Dopamine Content ◽  
Steroid Sensitivity ◽  
Inhibitory Transmitter ◽  
Strain Dependent

We have previously shown that 7B2 null mice on the 129/SvEvTac (129) genetic background die at 5 weeks of age with hypercorticosteronemia due to a Cushing’s-like disease unless they are rescued by adrenalectomy; however, 7B2 nulls on the C57BL/6NTac (B6) background remain healthy, with normal steroid levels. Since background exerts such a profound influence on the phenotype of this mutation, we have evaluated whether these two different mouse strains respond differently to high circulating steroids by chronically treating wild-type 129 and B6 mice with the synthetic steroid dexamethasone (Dex). Dex treatment decreased the dopamine content of the neurointermediate lobes (NIL) of 129 mice, leading to NIL enlargement and increased total D2R mRNA in the 129, but not the B6, NIL. Despite the decrease in this inhibitory transmitter, Dex-treated 129 mice exhibited reduced circulating α-melanocyte-stimulating hormone (α-MSH) along with reduced POMC-derived peptides compared with controls, possibly due to reduced POMC content in the NIL. In contrast, Dex-treated B6 mice showed lowered cellular ACTH, unchanged α-MSH and β-endorphin, and increased circulating α-MSH, most likely due to increased cleavage of NIL ACTH by increased PC2. Dex-treated 129 mice exhibited hyperinsulinemia and lowered blood glucose, whereas Dex-treated B6 mice showed slightly increased glucose levels despite their considerably increased insulin levels. Taken together, our results suggest that the endocrinological response of 129 mice to chronic Dex treatment is very different from that of B6 mice. These strain-dependent differences in steroid sensitivity must be taken into account when comparing different lines of transgenic or knockout mice.

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