scholarly journals Short-term high fat diet alters genes associated with metabolic and vascular dysfunction during adolescence in rats: a pilot study

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11714
Author(s):  
Alex E. Mohr ◽  
Rebecca A. Reiss ◽  
Monique Beaudet ◽  
Johnny Sena ◽  
Jay S. Naik ◽  
...  
Keyword(s):  
Gene Expression ◽  
High Fat Diet ◽  
Vascular Dysfunction ◽  
Critical Role ◽  
Chow Diet ◽  
Hormone Regulation ◽  
Metabolic Dysfunction ◽  
High Fat ◽  
Network Analyses ◽  
Vascular Regulation

Background Diet-induced metabolic dysfunction precedes multiple disease states including diabetes, heart disease, and vascular dysfunction. The critical role of the vasculature in disease progression is established, yet the details of how gene expression changes in early cardiovascular disease remain an enigma. The objective of the current pilot project was to evaluate whether a quantitative assessment of gene expression within the aorta of six-week old healthy male Sprague-Dawley rats compared to those exhibiting symptoms of metabolic dysfunction could reveal potential mediators of vascular dysfunction. Methods RNA was extracted from the aorta of eight rats from a larger experiment; four animals fed a high-fat diet (HFD) known to induce symptoms of metabolic dysfunction (hypertension, increased adiposity, fasting hyperglycemia) and four age-matched healthy animals fed a standard chow diet (CHOW). The bioinformatic workflow included Gene Ontology (GO) biological process enrichment and network analyses. Results The resulting network contained genes relevant to physiological processes including fat and protein metabolism, oxygen transport, hormone regulation, vascular regulation, thermoregulation, and circadian rhythm. The majority of differentially regulated genes were downregulated, including several associated with circadian clock function. In contrast, leptin and 3-hydroxy-3-methylglutaryl-CoA synthase 2 (Hmgcs2) were notably upregulated. Leptin is involved in several major energy balance signaling pathways and Hmgcs2 is a mitochondrial enzyme that catalyzes the first reaction of ketogenesis. Conclusion Together, these data describe changes in gene expression within the aortic wall of HFD rats with early metabolic dysfunction and highlight potential pathways and signaling intermediates that may impact the development of early vascular dysfunction.

scholarly journals CD44 contributes to hyaluronan-mediated insulin resistance in skeletal muscle of high-fat-fed C57BL/6 mice

2019 ◽  
Vol 317 (6) ◽  
pp. E973-E983 ◽  
Author(s):  
Annie Hasib ◽  
Chandani K. Hennayake ◽  
Deanna P. Bracy ◽  
Aimée R. Bugler-Lamb ◽  
Louise Lantier ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
High Fat Diet ◽  
Critical Role ◽  
Chow Diet ◽  
Wild Type ◽  
High Fat ◽  
Insulin Resistant ◽  
Beneficial Effects

Extracellular matrix hyaluronan is increased in skeletal muscle of high-fat-fed insulin-resistant mice, and reduction of hyaluronan by PEGPH20 hyaluronidase ameliorates diet-induced insulin resistance (IR). CD44, the main hyaluronan receptor, is positively correlated with type 2 diabetes. This study determines the role of CD44 in skeletal muscle IR. Global CD44-deficient ( cd44−/−) mice and wild-type littermates ( cd44+/+) were fed a chow diet or 60% high-fat diet for 16 wk. High-fat-fed cd44−/− mice were also treated with PEGPH20 to evaluate its CD44-dependent action. Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp (ICv). High-fat feeding increased muscle CD44 protein expression. In the absence of differences in body weight and composition, despite lower clamp insulin during ICv, the cd44−/− mice had sustained glucose infusion rate (GIR) regardless of diet. High-fat diet-induced muscle IR as evidenced by decreased muscle glucose uptake (Rg) was exhibited in cd44+/+ mice but absent in cd44−/− mice. Moreover, gastrocnemius Rg remained unchanged between genotypes on chow diet but was increased in high-fat-fed cd44−/− compared with cd44+/+ when normalized to clamp insulin concentrations. Ameliorated muscle IR in high-fat-fed cd44−/− mice was associated with increased vascularization. In contrast to previously observed increases in wild-type mice, PEGPH20 treatment in high-fat-fed cd44−/− mice did not change GIR or muscle Rg during ICv, suggesting a CD44-dependent action. In conclusion, genetic CD44 deletion improves muscle IR, and the beneficial effects of PEGPH20 are CD44-dependent. These results suggest a critical role of CD44 in promoting hyaluronan-mediated muscle IR, therefore representing a potential therapeutic target for diabetes.

scholarly journals Loss of APJ mediated β-arrestin signalling improves high-fat diet induced metabolic dysfunction but does not alter cardiac function in mice

2020 ◽  
Vol 477 (17) ◽  
pp. 3313-3327
Author(s):  
Na Li ◽  
Xiaochuan Ma ◽  
Ting Ban ◽  
Shaohua Xu ◽  
Yingli Ma ◽  
...  
Keyword(s):  
Cardiac Function ◽  
G Protein ◽  
High Fat Diet ◽  
Pressure Overload ◽  
Receptor Activation ◽  
Chow Diet ◽  
Metabolic Dysfunction ◽  
High Fat ◽  
Protein Activity ◽  
Fat Composition

Apelin receptor (APJ) is a G protein-coupled receptor that contributes to many physiological processes and is emerging as a therapeutic target to treat a variety of diseases. For most disease indications the role of G protein vs β-arrestin signalling in mitigating disease pathophysiology remains poorly understood. This hinders the development of G protein biased APJ agonists, which have been proposed to have several advantages over balanced APJ signalling agonists. To elucidate the contribution of APJ β-arrestin signalling, we generated a transgenic mouse harbouring a point mutation (APJ I107A) that maintains full G protein activity but fails to recruit β-arrestin following receptor activation. APJ I107A mutant mice did not alter cardiac function at rest, following exercise challenge or in response to pressure overload induced cardiac hypertrophy. Additionally, APJ I107A mice have comparable body weights, plasma glucose and lipid levels relative to WT mice when fed a chow diet. However, APJ I107A mice showed significantly lower body weight, blood insulin levels, improved glucose tolerance and greater insulin sensitivity when fed a high-fat diet. Furthermore, loss of APJ β-arrestin signalling also affected fat composition and the expression of lipid metabolism related genes in adipose tissue from high-fat fed mice. Taken together, our results suggest that G protein biased APJ activation may be more effective for certain disease indications given that loss of APJ mediated β-arrestin signalling appears to mitigate several aspects of diet induced metabolic dysfunction.

scholarly journals A Maternal High Fat Diet Leads to Sex-Specific Programming of Mechanical Properties in Supraspinatus Tendons of Adult Rat Offspring

2021 ◽  
Vol 8 ◽  
Author(s):  
Scott M. Bolam ◽  
Vidit V. Satokar ◽  
Subhajit Konar ◽  
Brendan Coleman ◽  
Andrew Paul Monk ◽  
...  
Keyword(s):  
Gene Expression ◽  
High Fat Diet ◽  
Maternal Diet ◽  
Biomechanical Properties ◽  
Female Offspring ◽  
Male Offspring ◽  
Chow Diet ◽  
Adult Offspring ◽  
High Fat ◽  
The Impact

Background: Over half of women of reproductive age are now overweight or obese. The impact of maternal high-fat diet (HFD) is emerging as an important factor in the development and health of musculoskeletal tissues in offspring, however there is a paucity of evidence examining its effects on tendon. Alterations in the early life environment during critical periods of tendon growth therefore have the potential to influence tendon health that cross the lifespan. We hypothesised that a maternal HFD would alter biomechanical, morphological and gene expression profiles of adult offspring rotator cuff tendon.Materials and Methods: Female Sprague-Dawley rats were randomly assigned to either: control diet (CD; 10% kcal or 43 mg/g from fat) or HFD (45% kcal or 235 mg/g from fat) 14 days prior to mating and throughout pregnancy and lactation. Eight female and male offspring from each maternal diet group were weaned onto a standard chow diet and then culled at postnatal day 100 for tissue collection. Supraspinatus tendons were used for mechanical testing and histological assessment (cellularity, fibre organisation, nuclei shape) and tail tendons were collected for gene expression analysis.Results: A maternal HFD increased the elasticity (Young's Modulus) in the supraspinatus tendon of male offspring. Female offspring tendon biomechanical properties were not affected by maternal HFD. Gene expression of SCX and COL1A1 were reduced in male and female offspring of maternal HFD, respectively. Despite this, tendon histological organisation were similar between maternal diet groups in both sexes.Conclusion: An obesogenic diet during pregnancy increased tendon elasticity in male, but not female, offspring. This is the first study to demonstrate that maternal diet can modulate the biomechanical properties of offspring tendon. A maternal HFD may be an important factor in regulating adult offspring tendon homeostasis that may predispose offspring to developing tendinopathies and adverse tendon outcomes in later life.

scholarly journals Adipocyte Utx Deficiency Promotes High-Fat Diet-Induced Metabolic Dysfunction in Mice

Cells ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 181
Author(s):  
Fenfen Li ◽  
Shirong Wang ◽  
Xin Cui ◽  
Jia Jing ◽  
Liqing Yu ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
High Fat Diet ◽  
Whole Body ◽  
Brown Adipocyte ◽  
Chow Diet ◽  
Main Function ◽  
Metabolic Dysfunction ◽  
High Fat ◽  
Brown Adipose

While the main function of white adipose tissue (WAT) is to store surplus of energy as triacylglycerol, that of brown adipose tissue (BAT) is to burn energy as heat. Epigenetic mechanisms participate prominently in both WAT and BAT energy metabolism. We previously reported that the histone demethylase ubiquitously transcribed tetratricopeptide (Utx) is a positive regulator of brown adipocyte thermogenesis. Here, we aimed to investigate whether Utx also regulates WAT metabolism in vivo. We generated a mouse model with Utx deficiency in adipocytes (AUTXKO). AUTXKO animals fed a chow diet had higher body weight, more fat mass and impaired glucose tolerance. AUTXKO mice also exhibited cold intolerance with an impaired brown fat thermogenic program. When challenged with high-fat diet (HFD), AUTXKO mice displayed adipose dysfunction featured by suppressed lipogenic pathways, exacerbated inflammation and fibrosis with less fat storage in adipose tissues and more lipid storage in the liver; as a result, AUTXKO mice showed a disturbance in whole body glucose homeostasis and hepatic steatosis. Our data demonstrate that Utx deficiency in adipocytes limits adipose tissue expansion under HFD challenge and induces metabolic dysfunction via adipose tissue remodeling. We conclude that adipocyte Utx is a key regulator of systemic metabolic homeostasis.

scholarly journals Long-term high-fat diet induces hippocampal microvascular insulin resistance and cognitive dysfunction

2017 ◽  
Vol 312 (2) ◽  
pp. E89-E97 ◽  
Author(s):  
Zhuo Fu ◽  
Jing Wu ◽  
Tanseli Nesil ◽  
Ming D. Li ◽  
Kevin W. Aylor ◽  
...  
Keyword(s):  
Cognitive Function ◽  
High Fat Diet ◽  
Critical Role ◽  
Capillary Density ◽  
Chow Diet ◽  
High Fat ◽  
Insulin Resistant ◽  
Old Rats ◽  
Insulin Responses

Insulin action on hippocampus improves cognitive function, and obesity and type 2 diabetes are associated with decreased cognitive function. Cerebral microvasculature plays a critical role in maintaining cerebral vitality and function by supplying nutrients, oxygen, and hormones such as insulin to cerebral parenchyma, including hippocampus. In skeletal muscle, insulin actively regulates microvascular opening and closure, and this action is impaired in the insulin-resistant states. To examine insulin’s action on hippocampal microvasculature and parenchyma and the impact of diet-induced obesity, we determined cognitive function and microvascular insulin responses, parenchyma insulin responses, and capillary density in the hippocampus in 2- and 8-mo-old rats on chow diet and 8-mo-old rats on a long-term high-fat diet (6 mo). Insulin infusion increased hippocampal microvascular perfusion in rats on chow diet by ~80–90%. High-fat diet feeding completely abolished insulin-mediated microvascular responses and protein kinase B phosphorylation but did not alter the capillary density in the hippocampus. This was associated with a significantly decreased cognitive function assessed using both the two-trial spontaneous alternation behavior test and the novel object recognition test. As the microvasculature provides the needed endothelial surface area for delivery of nutrients, oxygen, and insulin to hippocampal parenchyma, we conclude that hippocampal microvascular insulin resistance may play a critical role in the development of cognitive impairment seen in obesity and diabetes. Our results suggest that improvement in hippocampal microvascular insulin sensitivity might help improve or reverse cognitive function in the insulin-resistant states.

Maternal and postweaning diet interaction alters hypothalamic gene expression and modulates response to a high-fat diet in male offspring

2009 ◽  
Vol 297 (4) ◽  
pp. R1049-R1057 ◽  
Author(s):  
Kathleen C. Page ◽  
Raleigh E. Malik ◽  
Joshua A. Ripple ◽  
Endla K. Anday
Keyword(s):  
Body Weight ◽  
High Fat Diet ◽  
Saturated Fat ◽  
Male Offspring ◽  
Regulatory Subunit ◽  
Cytokine Signaling ◽  
Chow Diet ◽  
Metabolic Dysfunction ◽  
High Fat ◽  
Pregnancy And Lactation

Epidemiological data and results from animal studies indicate that imbalances in maternal nutrition impact the expression of metabolic disorders in the offspring. We tested the hypothesis that consumption of excess saturated fats during pregnancy and lactation contributes to adult metabolic dysfunction and that these disturbances can be further influenced by the postweaning diet. Adult male offspring from chow-fed dams were compared with males from dams fed a diet high in saturated fat (45 kcal/100 kcal) before mating, pregnancy, and lactation. Offspring were weaned to a standard chow diet or high fat diet. Animals were killed at 120 days after a 24-h fast. Body weight, energy intake, fat deposition, serum leptin, and insulin were significantly higher in offspring from control or high-fat dams if fed a high-fat diet from weaning to adulthood. Only fat-fed offspring from fat-fed dams were hyperglycemic. Leptin receptor, proopiomelanocortin, and neuropeptide Y (NPY) were also significantly increased in offspring exposed to excess saturated fat during gestation and into adulthood, whereas NPY1 receptor was downregulated. Signal transducer and activator of transcription 3 mRNA level was significantly higher in offspring from high-fat-fed dams compared with controls; however, no change was detected in cocaine and amphetamine-regulated transcript or suppressor of cytokine signaling 3. An increase in agouti-related protein expression did not reach significance. A significant reduction in phosphatidylinositol 3-kinase regulatory subunit (p85α) coupled to an upregulation of protein kinase B was observed in offspring from high-fat-fed dams transitioned to chow food, whereas p85α expression was significantly increased in high-fat offspring weaned to the high-fat diet. These data support the hypothesis that early life exposure to excess fat is associated with changes in hypothalamic regulation of body weight and energy homeostasis and that postweaning diet influences development of metabolic dysfunction and obesity.

Obesity induced by a high-fat diet downregulates apolipoprotein A-IV gene expression in rat hypothalamus

2004 ◽  
Vol 287 (2) ◽  
pp. E366-E370 ◽  
Author(s):  
Min Liu ◽  
Ling Shen ◽  
Yin Liu ◽  
Stephen C. Woods ◽  
Randy J. Seeley ◽  
...  
Keyword(s):  
Gene Expression ◽  
High Fat Diet ◽  
Lipid Emulsion ◽  
Dietary Lipids ◽  
Chow Diet ◽  
Mrna Levels ◽  
High Fat ◽  
Diet Induced Obesity ◽  
Apolipoprotein A ◽  
Body Weights

Apolipoprotein A-IV (apo A-IV) is an anorectic protein produced in the intestine and brain that has been proposed as a satiety signal. To determine whether diet-induced obesity alters apo A-IV gene expression in the intestine and hypothalamus, rats were fed a high-fat (HF), low-fat (LF), or standard chow (CHOW) diet for 2, 4, 6, 8, or 10 wk. Rats fed the HF diet had significantly greater body weights than rats given the LF and CHOW diets. Intestinal and plasma apo A-IV levels were comparable across dietary groups and time. LF and CHOW rats had comparable hypothalamic apo A-IV mRNA across the course of the experiment. However, HF rats had a slow and progressive diminution in hypothalamic apo A-IV mRNA over time that became significantly lower than that of LF or CHOW rats by 10 wk. Intragastric infusion of lipid emulsion to animals that were fasted overnight significantly stimulated hypothalamic apo A-IV mRNA in LF and CHOW rats but had no effect in HF rats. These results demonstrate that chronic consumption of a HF diet significantly reduces apo A-IV mRNA levels and the response of apo A-IV gene expression to dietary lipids in the hypothalamus. This raises the possibility that dysregulation of hypothalamic apo A-IV could contribute to diet-induced obesity.

scholarly journals Administration of hydro-alcoholic extract of spinach improves oxidative stress and inflammation in high-fat diet-induced NAFLD rats

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ali Amirinejad ◽  
Ali Saneei Totmaj ◽  
Farzaneh Mardali ◽  
Azita Hekmatdoost ◽  
Hadi Emamat ◽  
...  
Keyword(s):  
Gene Expression ◽  
Enzyme Activity ◽  
Liver Disease ◽  
High Fat Diet ◽  
Treatment Phase ◽  
Chow Diet ◽  
Alcoholic Extract ◽  
Sprague Dawley ◽  
High Fat ◽  
Prevention And Treatment

Abstract Background Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. The aim of this study was to evaluate the effects of hydro-alcoholic extract of spinach (HES) on hepatic and serum measurements of NAFLD in a rat model. Methods In the prevention phase, 18 Sprague–Dawley rats were fed a high-fat diet, a high-fat diet plus 400 mg/kg HES, or a chow diet for seven weeks. For the treatment phase, after the induction of NAFLD, they were fed a high-fat diet, a high-fat diet plus 400 mg/kg HES, a chow diet, or a chow diet plus 400 mg/kg HES for four weeks (n = 6). Results Administration of HES combined with high-fat diet in rats was associated with decreased food intake (P < 0.01), weight loss (P = 0.01), and increased superoxide dismutase (SOD) (P = 0.02) enzyme activity in the liver, at the end of the prevention phase. hs-CRP (P < 0.05), PTX-3 (P < 0.05), and TNF-α (P < 0.05) gene expression in the liver were decreased and PPAR-γ (P < 0.05) gene expression in the liver was increased by spinach intake, both in the prevention and treatment phases. Furthermore, administration of spinach in the treatment phase increased serum TAC (P = 0.03) and hepatic GPX (P = 0.01) enzyme activity. Conclusion Taking into account the potential beneficial effects of HES on prevention and treatment of NAFLD in the present study, to confirm these findings, we propose that further clinical trials be conducted on human subjects with NAFLD.

scholarly journals Acute vs chronic exposure to high fat diet leads to distinct regulation of PKA

2017 ◽  
Vol 59 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Edra London ◽  
Maria Nesterova ◽  
Constantine A Stratakis
Keyword(s):  
High Fat Diet ◽  
Energy Homeostasis ◽  
Critical Role ◽  
Metabolic Dysfunction ◽  
High Fat ◽  
Diet Induced Obesity ◽  
Subunit Expression ◽  
Peripheral Effect ◽  
Dependent Protein ◽  
The Impact

The cAMP-dependent protein kinase (PKA) is an essential regulator of lipid and glucose metabolism that plays a critical role in energy homeostasis. The impact of diet on PKA signaling has not been defined, although perturbations in individual PKA subunits are associated with changes in adiposity, physical activity and energy intake in mice and humans. We hypothesized that a high fat diet (HFD) would elicit peripheral and central alterations in the PKA system that would differ depending on length of exposure to HFD; these differences could protect against or promote diet-induced obesity (DIO). 12-week-old C57Bl/6J mice were randomly assigned to a regular diet or HFD and weighed weekly throughout the feeding studies (4 days, 14 weeks; respectively), and during killing. PKA activity and subunit expression were measured in liver, gonadal adipose tissue (AT) and brain. Acute HFD-feeding suppressed basal hepatic PKA activity. In contrast, hepatic and hypothalamic PKA activities were significantly increased after chronic HFD-feeding. Changes in AT were more subtle, and overall, altered PKA regulation in response to chronic HFD exposure was more profound in female mice. The suppression of hepatic PKA activity after 4 day HFD-feeding was indicative of a protective peripheral effect against obesity in the context of overnutrition. In response to chronic HFD-feeding, and with the development of DIO, dysregulated hepatic and hypothalamic PKA signaling was a signature of obesity that is likely to promote further metabolic dysfunction in mice.

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