P1-157: ESTROGEN LOSS INCREASES AMYLOIDOGENIC PROCESSING, WITH A HIGH FAT DIET EXACERBATING CHANGES IN MARKERS OF AMYLOID DEGRADATION IN C57BL6 FEMALE MICE

2019 ◽  
Vol 15 ◽  
pp. P296-P297
Author(s):  
Grant C. Hayward ◽  
Bradley J. Baranowski ◽  
Danny M. Marko ◽  
Rebecca E.K. MacPherson
2021 ◽  
Vol 137 ◽  
pp. 111370
Author(s):  
Chethan Sampath ◽  
Derek Wilus ◽  
Mohammad Tabatabai ◽  
Michael L. Freeman ◽  
Pandu R. Gangula

2021 ◽  
Vol 22 (8) ◽  
pp. 4277
Author(s):  
Marija Pinterić ◽  
Iva I. Podgorski ◽  
Marijana Popović Hadžija ◽  
Ivana Tartaro Bujak ◽  
Ana Tadijan ◽  
...  

High fat diet (HFD) is an important factor in the development of metabolic diseases, with liver as metabolic center being highly exposed to its influence. However, the effect of HFD-induced metabolic stress with respect to ovary hormone depletion and sirtuin 3 (Sirt3) is not clear. Here we investigated the effect of Sirt3 in liver of ovariectomized and sham female mice upon 10 weeks of feeding with standard-fat diet (SFD) or HFD. Liver was examined by Folch, gas chromatography and lipid hydroperoxide analysis, histology and oil red staining, RT-PCR, Western blot, antioxidative enzyme and oxygen consumption analyses. In SFD-fed WT mice, ovariectomy increased Sirt3 and fatty acids synthesis, maintained mitochondrial function, and decreased levels of lipid hydroperoxides. Combination of ovariectomy and Sirt3 depletion reduced pparα, Scd-1 ratio, MUFA proportions, CII-driven respiration, and increased lipid damage. HFD compromised CII-driven respiration and activated peroxisomal ROS scavenging enzyme catalase in sham mice, whereas in combination with ovariectomy and Sirt3 depletion, increased body weight gain, expression of NAFLD- and oxidative stress-inducing genes, and impaired response of antioxidative system. Overall, this study provides evidence that protection against harmful effects of HFD in female mice is attributed to the combined effect of female sex hormones and Sirt3, thus contributing to preclinical research on possible sex-related therapeutic agents for metabolic syndrome and associated diseases.


2004 ◽  
Vol 287 (1) ◽  
pp. R147-R156 ◽  
Author(s):  
Assim Alfadda ◽  
Rosangela A. DosSantos ◽  
Zaruhi Stepanyan ◽  
Husnia Marrif ◽  
J. Enrique Silva

To define the role of mitochondrial glycerol-3-phosphate dehydrogenase (mGPD; EC 1.1.99.5 ) in energy balance and intermediary metabolism, we studied transgenic mice not expressing mGPD (mGPD−/−). These mice had ≈14% lower blood glucose; ≈50% higher serum glycerol; ≈80% higher serum triglycerides; and at thermoneutrality, their energy expenditure (Qo2) was 15% lower than in wild-type (WT) mice. Glycerol-3-phosphate levels and lactate-to-pyruvate ratios were threefold elevated in muscle, but not in liver, of mGPD−/− mice. WT and mGPD−/− mice were then challenged with a high-fat diet, fasting, or food restriction. The high-fat diet caused more weight gain and adiposity in mGPD−/− than in WT female mice, without the genotype differentially affecting Qo2 or energy intake. After a 30-h fast, WT female lost 60% more weight than mGPD−/− mice but these latter became more hypothermic. When energy intake was restricted to 50–70% of the ad libitum intake for 10 days, mGPD−/− female mice lost less weight than WT controls, but they had lower Qo2 and body temperature. WT and mGPD−/− male mice did not differ significantly in their responses to these challenges. These results show that the lack of mGPD causes significant alterations of intermediary metabolism, which are more pronounced in muscle than liver and lead to a thrifty phenotype that is more marked in females than males. Lower T4-to-T3 conversion in mGPD−/− females and a greater reliance of normal females on mGPD to respond to high-fat diets make the lack of the enzyme more consequential in the female gender.


Diabetes ◽  
2021 ◽  
Vol 70 (Supplement 1) ◽  
pp. 176-OR
Author(s):  
PAUL SOHN ◽  
PREETHI KRISHNAN ◽  
CHIH-CHUN LEE ◽  
TATSUYOSHI KONO ◽  
CARMELLA EVANS-MOLINA

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A806-A806
Author(s):  
Rachel Bell ◽  
Elisa Villalobos ◽  
Mark Nixon ◽  
Allende Miguelez-Crespo ◽  
Matthew Sharp ◽  
...  

Abstract Glucocorticoids play a critical role in metabolic homeostasis. Chronic or excessive activation of the glucocorticoid receptor (GR) in adipose tissue contributes to metabolic disorders such as glucose intolerance and insulin resistance. Steroid-metabolising enzymes in adipose, such as 11β-HSD1 or 5α-reductase, modulate the activation of GR by converting primary glucocorticoids into more or less potent ligands. Carbonyl reductase 1 (CBR1) is a novel regulator of glucocorticoid metabolism, converting corticosterone/cortisol to 20β-dihydrocorticosterone/cortisol (20β-DHB/F); a metabolite which retains GR activity. CBR1 is abundant in adipose tissue and increased in obese adipose of mice and humans1 and increased Cbr1 expression is associated with increased fasting glucose1. We hypothesised that increased Cbr1/20β-DHB in obese adipose contributes to excessive GR activation and worsens glucose tolerance. We generated a novel murine model of adipose-specific Cbr1 over-expression (R26-Cbr1Adpq) by crossing conditional knock-in mice with Adiponectin-Cre mice. CBR1 protein and activity were doubled in subcutaneous adipose tissue of male and female R26-Cbr1Adpq mice compared with floxed controls; corresponding to a two-fold increase 20β-DHB (1.6 vs. 4.2ng/g adipose; P=0.0003; n=5-7/group). There were no differences in plasma 20β-DHB or corticosterone. Bodyweight, lean or fat mass, did not differ between male or female R26-Cbr1Adpq mice and floxed controls. Lean male R26-Cbr1Adpq mice had higher fasting glucose (9.5±0.3 vs. 8.4±0.3mmol/L; P=0.04) and worsened glucose tolerance (AUC 1819±66 vs. 1392±14; P=0.03). Female R26-Cbr1Adpq mice also had a worsened glucose tolerance but fasting glucose was not altered with genotype. There were no differences in fasting insulin or non-esterified fatty acid between genotypes in either sex. Expression of GR-induced genes Pnpla2, Gilz and Per1, were increased in adipose of R26-Cbr1Adpq mice. Following high-fat diet induced obesity, no differences in bodyweight, lean or fat mass, with genotype were observed in male and female mice, and genotype differences in fasting glucose and glucose tolerance were abolished. In conclusion, adipose-specific over-expression of Cbr1 in lean male and female mice led to increased levels of 20β-DHB in adipose but not plasma, and both sexes having worsened glucose tolerance. The influence of adipose CBR1/20β-DHB on glucose tolerance was not associated with altered fat mass or bodyweight and was attenuated by high-fat diet-induced obesity. These metabolic consequences of Cbr1 manipulation require careful consideration given the wide variation in CBR1 expression in the human population, the presence of inhibitors and enhancers in many foodstuffs and the proposed use of inhibitors as an adjunct for cancer treatment regimens. Reference: Morgan et al., Scientific Reports. 2017; 7.


Author(s):  
Kelly N. Z. Fuller ◽  
Colin S. McCoin ◽  
Alex T. Von Schulze ◽  
Claire J. Houchen ◽  
Michael A. Choi ◽  
...  

We recently reported that compared to males, female mice have increased hepatic mitochondrial respiratory capacity and are protected against high-fat diet-induced steatosis. Here we sought to determine the role of estrogen in hepatic mitochondrial function, steatosis, and bile acid metabolism in female mice, as well as investigate potential benefits of exercise in the absence or presence of estrogen via ovariectomy (OVX). Female C57BL mice (n=6 per group) were randomly assigned to sham surgery (Sham), ovariectomy (OVX), or OVX plus estradiol replacement therapy (OVX+Est). Half of the mice in each treatment group were sedentary (SED) or had access to voluntary wheel running (VWR). All mice were fed a high-fat diet (HFD) and were housed at thermoneutral temperatures. We assessed isolated hepatic mitochondrial respiratory capacity using the Oroboros O2k with both pyruvate and palmitoylcarnitine as substrates. As expected, OVX mice presented with greater hepatic steatosis, weight gain, and fat mass gain compared to Sham and OVX+Est animals. Hepatic mitochondrial coupling (Basal/State 3 respiration) with pyruvate was impaired following OVX, but both VWR and estradiol treatment rescued coupling to levels greater than or equal to Sham animals. Estradiol and exercise also had different effects on liver electron transport chain protein expression depending on OVX status. Markers of bile acid metabolism and excretion were also impaired by ovariectomy but rescued with estradiol add-back. Together our data suggest that estrogen depletion impairs hepatic mitochondrial function and liver health, and that estradiol replacement and modest exercise can aid in rescuing this phenotype.


2019 ◽  
Vol 30 (1) ◽  
pp. 1271-1285 ◽  
Author(s):  
Wentao Qi ◽  
Yong Wang ◽  
Jinli Yao ◽  
Hui Sun ◽  
Xiaoliang Duan ◽  
...  

2019 ◽  
Vol 149 (1) ◽  
pp. 73-97 ◽  
Author(s):  
Eugene Nyamugenda ◽  
Marcus Trentzsch ◽  
Susan Russell ◽  
Tiffany Miles ◽  
Gunnar Boysen ◽  
...  

2020 ◽  
Vol 128 (5) ◽  
pp. 1251-1261
Author(s):  
Kelly N. Z. Fuller ◽  
Colin S. McCoin ◽  
Julie Allen ◽  
Shelby Bell-Glenn ◽  
Devin C. Koestler ◽  
...  

This is the first study focusing on hepatic mitochondrial respiratory outcomes in response to lipid overload via a high-fat diet (HFD) combined with intralipid injection. Novel findings include no effect of intralipid injection on mitochondrial outcomes of interest, despite increased circulating lipid concentrations. However, we report pronounced differences in hepatic mitochondrial respiration, complex protein expression, and H2O2 production by sex and BCL-2/adenovirus EIB 19-kDa interacting protein (BNIP3) genotype. Specifically, female mice had lower H2O2 emission globally and on an acute HFD, females had greater hepatic mitochondrial respiration than males, whereas BNIP3 knockout (KO) animals had greater mitochondrial coupling and complex protein expression than wild-type (WT) animals.


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