Nobiletin Prevents High-Fat Diet-Induced Dysregulation of Intestinal Lipid Metabolism and Attenuates Postprandial Lipemia

Objective: Nobiletin is a dietary flavonoid that improves insulin resistance and atherosclerosis in mice with metabolic dysfunction. Dysregulation of intestinal lipoprotein metabolism contributes to atherogenesis. The objective of the study was to determine if nobiletin targets the intestine to improve metabolic dysregulation in both male and female mice. Approach and Results: Triglyceride-rich lipoprotein (TRL) secretion, intracellular triglyceride kinetics, and intestinal morphology were determined in male and female LDL (low-density lipoprotein) receptor knockout, and male wild-type mice fed a standard laboratory diet or high-fat, high-cholesterol diet ± nobiletin using an olive oil gavage, radiotracers, and electron microscopy. Nobiletin attenuated postprandial TRL levels in plasma and enhanced TRL clearance. Nobiletin reduced fasting jejunal triglyceride accumulation through accelerated TRL secretion and lower jejunal fatty acid synthesis with no impact on fatty acid oxidation. Fasting-refeeding experiments revealed that nobiletin led to higher levels of phosphorylated AKT and FoxO1 (forkhead box O1) and normal Srebf1-c expression indicating increased insulin sensitivity. Intestinal length and weight were diminished by high-fat feeding and restored by nobiletin. Both fasting and postprandial plasma GLP-1 (glucagon-like peptide-1; and likely GLP-2) were elevated in response to nobiletin. Treatment with a GLP-2 receptor antagonist, GLP-2(3-33), reduced villus length in high fat-fed mice but did not impact TRL secretion in any diet group. In contrast to males, nobiletin did not improve postprandial lipid parameters in female mice. Conclusions: Nobiletin opposed the effects of the high-fat diet by normalizing intestinal de novo lipogenesis through improved insulin sensitivity. Nobiletin prevents postprandial lipemia because the enhanced TRL clearance more than compensates for increased TRL secretion.

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Tpcn2 knockout mice have improved insulin sensitivity and are protected against high-fat diet-induced weight gain

Physiological Genomics ◽

10.1152/physiolgenomics.00135.2017 ◽

2018 ◽

Vol 50 (8) ◽

pp. 605-614

Author(s):

Hong He ◽

Katie Holl ◽

Sarah DeBehnke ◽

Chay Teng Yeo ◽

Polly Hansen ◽

...

Keyword(s):

Body Weight ◽

Weight Gain ◽

Insulin Sensitivity ◽

Glucose Tolerance ◽

Knockout Mice ◽

High Fat Diet ◽

Wild Type ◽

High Fat ◽

Male And Female ◽

Female Mice

Type 2 diabetes is a complex disorder affected by multiple genes and the environment. Our laboratory has shown that in response to a glucose challenge, two-pore channel 2 ( Tpcn2) knockout mice exhibit a decreased insulin response but normal glucose clearance, suggesting they have improved insulin sensitivity compared with wild-type mice. We tested the hypothesis that improved insulin sensitivity in Tpcn2 knockout mice would protect against the negative effects of a high fat diet. Male and female Tpcn2 knockout (KO), heterozygous (Het), and wild-type (WT) mice were fed a low-fat (LF) or high-fat (HF) diet for 24 wk. HF diet significantly increases body weight in WT mice relative to those on the LF diet; this HF diet-induced increase in body weight is blunted in the Het and KO mice. Despite the protection against diet-induced weight gain, however, Tpcn2 KO mice are not protected against HF-diet-induced changes in glucose or insulin area under the curve during glucose tolerance tests in female mice, while HF diet has no significant effect on glucose tolerance in the male mice, regardless of genotype. Glucose disappearance during an insulin tolerance test is augmented in male KO mice, consistent with our previous findings suggesting enhanced insulin sensitivity in these mice. Male KO mice exhibit increased fasting plasma total cholesterol and triglyceride concentrations relative to WT mice on the LF diet, but this difference disappears in HF diet-fed mice where there is increased cholesterol and triglycerides across all genotypes. These data demonstrate that knockout of Tpcn2 may increase insulin action in male, but not female, mice. In addition, both male and female KO mice are protected against diet-induced weight gain, but this protection is likely independent from glucose tolerance, insulin sensitivity, and plasma lipid levels.

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Carbonyl Reductase 1 Overexpression in Adipose Amplifies Local Glucocorticoid Action and Impairs Glucose Tolerance in Lean Mice

Journal of the Endocrine Society ◽

10.1210/jendso/bvab048.1639 ◽

2021 ◽

Vol 5 (Supplement_1) ◽

pp. A806-A806

Author(s):

Rachel Bell ◽

Elisa Villalobos ◽

Mark Nixon ◽

Allende Miguelez-Crespo ◽

Matthew Sharp ◽

...

Keyword(s):

Adipose Tissue ◽

Glucose Tolerance ◽

Fat Mass ◽

High Fat Diet ◽

Fasting Glucose ◽

High Fat ◽

Male And Female ◽

Over Expression ◽

Female Mice ◽

Diet Induced Obesity

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.

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Injury to hypothalamic Sim1 neurons is a common feature of obesity by exposure to high‐fat diet in male and female mice

Journal of Neurochemistry ◽

10.1111/jnc.14662 ◽

2019 ◽

Vol 149 (1) ◽

pp. 73-97 ◽

Cited By ~ 4

Author(s):

Eugene Nyamugenda ◽

Marcus Trentzsch ◽

Susan Russell ◽

Tiffany Miles ◽

Gunnar Boysen ◽

...

Keyword(s):

High Fat Diet ◽

High Fat ◽

Male And Female ◽

Female Mice

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Increased Insulin Sensitivity by High-Altitude Hypoxia in Mice with High-Fat Diet-Induced Obesity Is Associated with Activated AMPK Signaling and Subsequently Enhanced Mitochondrial Biogenesis in Skeletal Muscles

Obesity Facts ◽

10.1159/000508112 ◽

2020 ◽

Vol 13 (5) ◽

pp. 455-472

Author(s):

Kang Song ◽

Yifan Zhang ◽

Qin Ga ◽

Zhenzhong Bai ◽

Ri-Li Ge

Keyword(s):

Fatty Acid ◽

Insulin Sensitivity ◽

Protein Kinase ◽

High Altitude ◽

Mitochondrial Biogenesis ◽

High Fat Diet ◽

Skeletal Muscles ◽

Acid Oxidation ◽

High Fat ◽

Low Altitude

Background: This study aimed to investigate whether and how high altitude-associated ambient hypoxia affects insulin sensitivity in mice fed a high-fat diet (HFD). Methods: Mice were randomly divided into a control group (with normal diet feeding and low-altitude housing), LA/HFD group (with HFD feeding and low-altitude housing), and HA/HFD group (with HFD feeding and high-altitude housing). Results: After 8 weeks, mice in the HA/HFD group showed improved insulin sensitivity-related indices compared with the LA/HFD group. In mice residing in a low-altitude region, HFD significantly impaired mitochondrial respiratory function and mitochondrial DNA content in skeletal muscles, which was partially reversed in mice in the HA/HFD group. In addition, the fatty acid oxidation-related enzyme gene CPT1 (carnitine palmitoyltransferase 1) and genes related to mitochondrial biogenesis such as peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1), and mitochondrial transcription factor A (Tfam) were upregulated in the skeletal muscles of mice housed at high altitude, in comparison to in the LA/HFD group. Furthermore, AMPK (adenosine monophosphate-activated protein kinase) signaling was activated in the skeletal muscles, as evidenced by a higher expression of phosphorylated AMPK (p-AMPK) and protein kinase B (p-AKT) in the HA/HFD group than in the LA/HFD group. Conclusion: Our study suggests that high-altitude hypoxia improves insulin sensitivity in mice fed an HFD, which is associated with AMPK activation in the skeletal muscle and consequently enhanced mitochondrial biogenesis and fatty acid oxidation. This work provides a molecular explanation for why high altitude is associated with a reduced incidence of insulin resistance in the obese population.

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Hypoglycemic effects and mechanisms of electroacupuncture on insulin resistance

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00465.2013 ◽

2014 ◽

Vol 307 (3) ◽

pp. R332-R339 ◽

Cited By ~ 8

Author(s):

Jieyun Yin ◽

Jian Kuang ◽

Manisha Chandalia ◽

Demidmaa Tuvdendorj ◽

Batbayar Tumurbaatar ◽

...

Keyword(s):

Insulin Resistance ◽

Fatty Acid ◽

Blood Glucose ◽

Insulin Sensitivity ◽

Free Fatty Acid ◽

Glucose Tolerance ◽

High Fat Diet ◽

Postprandial Glucose ◽

Tolerance Test ◽

High Fat

The aim of this study was to investigate effects and mechanisms of electroacupuncture (EA) on blood glucose and insulin sensitivity in mice fed a high-fat diet. Both wild-type (WT) and adipose ectonucleotide pyrophosphate phosphodiesterase (ENPP1) transgenic (TG) mice were fed a high-fat diet for 12 wk; for each mouse, an intraperitoneal glucose tolerance test (IPGTT) and insulin tolerance test (ITT) were performed with or without EA at abdomen or auricular areas. A high-fat diet-induced insulin resistance in both WT and TG mice. In the WT mice, EA at 3 Hz and 15 Hz, but not at 1 Hz or 100 Hz, via CV4+CV12 significantly reduced postprandial glucose levels; EA at 3 Hz was most potent. The glucose level was reduced by 61.7% at 60 min and 74.5% at 120 min with EA at 3 Hz (all P < 0.001 vs. control). Similar hypoglycemic effect was noted in the TG mice. On the contrary, EA at auricular points increased postprandial glucose level ( P < 0.03). 4). EA at 3 Hz via CV4+CV12 significantly enhanced the decrease of blood glucose after insulin injection, suggesting improvement of insulin sensitivity. Plasma free fatty acid was significantly suppressed by 42.5% at 15 min and 50.8% at 30 min with EA ( P < 0.01) in both WT and TG mice. EA improves glucose tolerance in both WT and TG mice fed a high-fat diet, and the effect is associated with stimulation parameters and acupoints and is probably attributed to the reduction of free fatty acid.

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P4-066: METABOLIC AND COGNITIVE EFFECTS OF HIGH FAT DIET IN MALE AND FEMALE MICE

Alzheimer s & Dementia ◽

10.1016/j.jalz.2018.06.2469 ◽

2006 ◽

Vol 14 (7S_Part_27) ◽

pp. P1458-P1458

Author(s):

Abigail E. Salinero ◽

Lisa S. Robison ◽

Brian M. Anderson ◽

David Riccio ◽

Kristen L. Zuloaga

Keyword(s):

High Fat Diet ◽

Cognitive Effects ◽

High Fat ◽

Male And Female ◽

Female Mice

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Modulation of Gr1low monocyte subset impacts insulin sensitivity and weight gain upon high-fat diet in female mice

International Journal of Obesity ◽

10.1038/ijo.2017.179 ◽

2017 ◽

Vol 41 (12) ◽

pp. 1805-1814 ◽

Cited By ~ 6

Author(s):

S Béliard ◽

W Le Goff ◽

F Saint-Charles ◽

L Poupel ◽

V Deswaerte ◽

...

Keyword(s):

Weight Gain ◽

Insulin Sensitivity ◽

High Fat Diet ◽

Monocyte Subset ◽

High Fat ◽

Female Mice

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Container-aided Integrative QTL and RNA-seq Analysis of Collaborative Cross Mice Supports Distinct Sex-Oriented Molecular Modes of Response in Obesity

10.21203/rs.2.13505/v1 ◽

2019 ◽

Author(s):

Ilona Binenbaum ◽

Hanifa Abu-Toamih Atamni ◽

Georgios Fotakis ◽

Georgia Kontogianni ◽

Theodoros Koutsandreas ◽

...

Keyword(s):

Gene Expression ◽

High Fat Diet ◽

Complex Traits ◽

Hepatic Gene Expression ◽

High Fat ◽

Mouse Population ◽

Male And Female ◽

Female Mice ◽

Diet Induced Obesity ◽

Genetic Mechanisms

Abstract Background: The CC mouse population is a valuable resource to study the genetic basis of complex traits, such as obesity. Although the development of obesity is influenced by environmental factors, the underlying genetic mechanisms play a crucial role in the response to these factors. The interplay between the genetic background and the gene expression pattern can provide further insight into this response, but we lack robust and easily reproducible workflows to integrate genomic and transcriptomic information in the CC mouse population. Results: We established an automated and reproducible integrative workﬂow to analyse complex traits in the CC mouse genetic reference panel at the genomic and transcriptomic levels. We implemented the analytical workﬂow to assess the underlying genetic mechanisms of host susceptibility to diet induced obesity and integrate these results with diet induced changes in the hepatic gene expression of susceptible and resistant mice. Hepatic gene expression diﬀers signiﬁcantly between obese and non-obese mice, with a signiﬁcant sex eﬀect, where male and female mice exhibit diﬀerent responses and coping mechanisms. Conclusion: Integration of the data showed that diﬀerent genes but similar pathways are involved in the genetic susceptibility and disturbed in diet induced obesity. Genetic mechanisms underlying susceptibility to high-fat diet induced obesity diﬀer in female and male mice. The clear distinction we observe in the systemic response to the high-fat diet challenge and to obesity between male and female mice points to the need for further research into distinct sex-related mechanisms in metabolic disease.

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Prolonged low-dose dioxin exposure impairs metabolic adaptability to high-fat diet feeding in female but not male mice

10.1101/2020.09.12.294587 ◽

2020 ◽

Author(s):

Geronimo Matteo ◽

Myriam P Hoyeck ◽

Hannah L Blair ◽

Julia Zebarth ◽

Kayleigh RC Rick ◽

...

Keyword(s):

Glucose Homeostasis ◽

High Fat Diet ◽

Plasma Insulin ◽

Low Dose ◽

Dependent Manner ◽

High Fat ◽

Male And Female ◽

Female Mice ◽

Insulin Levels ◽

Plasma Insulin Levels

AbstractObjectiveHuman studies consistently show an association between exposure to persistent organic pollutants, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, aka “dioxin”), and increased diabetes risk. We previously showed that acute high-dose TCDD exposure (20 μg/kg) decreased plasma insulin levels in both male and female mice in vivo; however, effects on glucose homeostasis were sex-dependent. The purpose of this study was to determine whether prolonged exposure to a physiologically relevant dose of TCDD impairs beta cell function and/or glucose homeostasis in a sex-dependent manner in either chow-fed or HFD-fed mice.MethodsMale and female mice were exposed to 20 ng/kg/d TCDD 2x/week for 12 weeks, and simultaneously fed a chow or 45% high-fat diet (HFD). Glucose metabolism was assessed by glucose and insulin tolerance tests throughout the study. Islets were isolated from females at 12 weeks for Tempo-Seq® analysis.ResultsLow-dose TCDD exposure did not lead to adverse metabolic consequences in chow-fed male or female mice, or in HFD-fed males. However, TCDD accelerated the onset of HFD-induced hyperglycemia and impaired glucose-induced plasma insulin levels in female mice. In addition, islet TempO-Seq® analysis showed that TCDD exposure promoted abnormal changes to endocrine and metabolic pathways in HFD-fed females.ConclusionsOur data suggest that TCDD exposure is more deleterious when combined with HFD-feeding in female mice, and that low-dose TCDD exposure increases diabetes susceptibility in females.

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