Intracerebroventricular Leptin Administration Differentially Alters Cardiac Energy Metabolism in Mice Fed a Low-fat and High-fat Diet

2011 ◽  
Vol 57 (1) ◽  
pp. 103-113 ◽  
Author(s):  
Wendy Keung ◽  
Virgilio J J Cadete ◽  
Arivazhagan Palaniyappan ◽  
Amissa Jablonski ◽  
Melanie Fischer ◽  
...  
2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Krystal M Roggerson ◽  
Sharon Francis

Obesity increases the risk of developing cardiovascular disease through vascular remodeling though the underlying mechanisms are not entirely understood. However, metabolic fuel partitioning and mitochondrial flexibility during energy metabolism may play a critical role. We demonstrated serum and glucocorticoid-inducible kinase 1 (SGK-1) is up-regulated in the vasculature of diet-induced obese mice and that SGK-1 deletion is protective against obesity-induced vascular remodeling by metabolically reprogramming vascular smooth muscle cell (VSMC) energy metabolism towards oxidative phosphorylation (OXPHOS) and away from glycolysis. Mitochondrial substrate availability and utilization of the primary metabolic fuels glucose, long chain fatty acids (LCFAs) and glutamine can drive metabolic reprogramming. Therefore, alterations in fuel utilization may contribute to vascular remodeling during obesity. The purpose of this study was to examine SGK-1’s role in 1) fuel dependency: a cell’s reliance for a specific fuel and 2) fuel capacity: a cell’s ability to oxidize a specific fuel to meet cellular energy demand under low-fat and high-fat diet-induced obesity. Using the MitoXpress Oxygen Consumption assay which measures OXPHOS, primary VSMCs isolated from wildtype (WT) and SMC-specific SGK-1 knockout (smSGK-1 KO) mice fed a 10% kcal low-fat or 45% kcal high-fat diet for eight weeks were seeded in a 96-well plate at a density of 6x10 4 cells/well in culture medium. To assess fuel dependency, cells were treated with fuel pathway inhibitors UK5099, Etomoxir or BPTES to block glucose, LCFA or glutamine oxidation, respectively. To measure fuel capacity, VSMCs were treated with a combination of two pathway inhibitors simultaneously. Next, samples were overlaid with a fluorescent extracellular oxygen consumption reagent, sealed with high-sensitivity mineral oil, then signals were read at 1.5-minute intervals for 2 hours at Ex/Em= 380/650 nm. Our results show WT VSMCs are exclusively glucose-dependent for OXPHOS regardless of dietary conditions. However, SGK-1 deletion induces a dependency for all three fuels for OXPHOS in VSMCs under low- and high-fat conditions. Even though WT and smSGK-1 KO VSMCs preferentially oxidized glucose for OXPHOS under low-fat conditions; SGK-1 deletion resulted in a 2.2-fold increase in glutamine capacity. Alternatively, WT VSMCs exposed to obesogenic conditions preferentially oxidized glutamine whereas SGK-1 deletion induced a nearly equal partitioning of all three fuels during obesity suggesting elevated mitochondrial flexibility. Overall, this study suggests SGK-1 increases glucose dependency for energy metabolism under physiological and obesogenic conditions. Also, increased glutamine utilization for OXPHOS during obesity may be an underlying cause of VSMC dysfunction and subsequent vascular impairment.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Laura K. Cole ◽  
Genevieve C. Sparagna ◽  
Marilyne Vandel ◽  
Bo Xiang ◽  
Vernon W. Dolinsky ◽  
...  

AbstractBerberine (BBR) is an isoquinoline alkaloid from plants known to improve cardiac mitochondrial function in gestational diabetes mellitus (GDM) offspring but the mechanism is poorly understood. We examined the role of the mitochondrial phospholipid cardiolipin (CL) in mediating this cardiac improvement. C57BL/6 female mice were fed either a Lean-inducing low-fat diet or a GDM-inducing high-fat diet for 6 weeks prior to breeding. Lean and GDM-exposed male offspring were randomly assigned a low-fat, high-fat, or high-fat diet containing BBR at weaning for 12 weeks. The content of CL was elevated in the heart of GDM offspring fed a high fat diet containing BBR. The increase in total cardiac CL was due to significant increases in the most abundant and functionally important CL species, tetralinoleoyl-CL and this correlated with an increase in the expression of the CL remodeling enzyme tafazzin. Additionally, BBR treatment increased expression of cardiac enzymes involved in fatty acid uptake and oxidation and electron transport chain subunits in high fat diet fed GDM offspring. Thus, dietary BBR protection from cardiac dysfunction in GDM exposed offspring involves improvement in mitochondrial function mediated through increased synthesis of CL.


2021 ◽  
Vol 22 (10) ◽  
pp. 5390
Author(s):  
Qianhui Zeng ◽  
Nannan Wang ◽  
Yaru Zhang ◽  
Yuxuan Yang ◽  
Shuangshuang Li ◽  
...  

Obesity-induced adipose tissue dysfunction and disorders of glycolipid metabolism have become a worldwide research priority. Zfp217 plays a crucial role in adipogenesis of 3T3-L1 preadipocytes, but about its functions in animal models are not yet clear. To explore the role of Zfp217 in high-fat diet (HFD)-induced obese mice, global Zfp217 heterozygous knockout (Zfp217+/−) mice were constructed. Zfp217+/− mice and Zfp217+/+ mice fed a normal chow diet (NC) did not differ significantly in weight gain, percent body fat mass, glucose tolerance, or insulin sensitivity. When challenged with HFD, Zfp217+/− mice had less weight gain than Zfp217+/+ mice. Histological observations revealed that Zfp217+/− mice fed a high-fat diet had much smaller white adipocytes in inguinal white adipose tissue (iWAT). Zfp217+/− mice had improved metabolic profiles, including improved glucose tolerance, enhanced insulin sensitivity, and increased energy expenditure compared to the Zfp217+/+ mice under HFD. We found that adipogenesis-related genes were increased and metabolic thermogenesis-related genes were decreased in the iWAT of HFD-fed Zfp217+/+ mice compared to Zfp217+/− mice. In addition, adipogenesis was markedly reduced in mouse embryonic fibroblasts (MEFs) from Zfp217-deleted mice. Together, these data indicate that Zfp217 is a regulator of energy metabolism and it is likely to provide novel insight into treatment for obesity.


2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S8-S9
Author(s):  
Julia Fritsch ◽  
Alejandra Quintero ◽  
Judith Pignac-Kobinger ◽  
Luis Garces ◽  
Ana Santander ◽  
...  

Abstract Background and Aims There is a lack of evidence-based dietary interventions in ulcerative colitis (UC) management. A diet high in fat and animal meat has been linked to an increased risk of UC. The aim of our study was to use a multilayered, multi-omic approach to comprehensively characterize the effect of a low fat, high fiber diet or a high fat diet in UC patients. Methods We enrolled patients with UC who were in remission or had mild disease with a flare within the last 18 months. We used a cross-over design in which patients received two dietary interventions: a low fat diet (LFD), containing 10% total calories from fat with an omega 6 to 3 ratio of below 3:1, and an idealized standard American diet (SAD), containing 35–40% total calories from fat with an omega 6 to 3 ratio of 20–30:1. Each diet was four weeks long with a two-week wash-out in between. The diet was catered and delivered to patients’ homes. Clinical symptoms, quality of life, and biochemical data were collected. Stool was collected for microbiome and metabolomic analyses. The primary endpoint was to determine adherence to a specified diet using catered meals; the secondary endpoint was to determine the clinical and subclinical effects of a low fat, high fiber diet or high fat diet in UC. Results Baseline diets varied widely but were generally lower in fiber as well as fruits and vegetables and higher in saturated fat than either of the study diets. There was a high rate of adherence to catered meals (SAD=86.68%, LFD=84.8%) with a 96.8% and 94.33% adherence to fat for SAD and LFD respectively. Patients that started in remission remained in remission (partial Mayo and sIBDQ). Following a LFD, patients saw a 20% improvement in their quality of life as measured by sIBDQ compared to their baseline. The effect of diet intervention on microbial diversity was reflected in the beta diversity with a significant increase in Faecalibacterium prausnitzii after LFD. CRP, sIBDQ, IL-6, and IL1β had a significant effect on overall gut microbiota composition as measured by Bray Curtis beta diversity (PERMANOVA)(P<0.007, P<0.001, P<0.021, P<0.048 respectively). The top taxa that contributes the most to this microbial variation from these clinical parameters was Faecalibacterium prausnitzii. Patients following a SAD had an increase in lauric acid, myristic acid, and N-oleoyl-L-phenylalanine with an increase in omega-6 metabolism pathways. Patients following a LFD had higher glycine, alanine, and phenyllactic acid with omega 3 metabolism pathways increased after LFD. Conclusions A low fat, high fiber diet is well tolerated and did not increase biochemical markers of inflammation. Catered meals and collection of microbiome, metabolome and biochemical data may allow early stratification of diet responders.


2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Megha Murali ◽  
Carla Taylor ◽  
Peter Zahradka ◽  
Jeffrey Wigle

Background and Objective: Arterial stiffness is recognized as being an independent predictor of incipient vascular disease associated with obesity and metabolic syndrome. In obese subjects, the decrease in the plasma level of adiponectin, an anti-diabetic and anti-atherogenic adipokine, is well known. Hence the aim of our study was to examine the effect of loss of adiponectin on the development of arterial stiffness in response to a high fat diet. Methods and Results: Male 8-week old adiponectin knockout (APN KO) and C57BL/6 (control) mice were fed a high fat diet (60% Calories from fat) for 12 weeks to induce obesity and insulin resistance (n=10/group). APN KO and C57BL/6 mice were fed a low fat diet (10% Calories from fat) and used as lean controls (n=10/group). After 12 weeks on the high fat diet, the APN KO mice weighed significantly more than the C57BL/6 mice (45.1±1.3 g vs 40.1±1.1 g, p=0.0008) but there was no difference in the final weights between genotypes fed the low fat diet. APN KO mice on both high and low fat diets for 12 weeks developed insulin resistance as measured by oral glucose tolerance test (Area under curve (AUC) mmol/L х min = 437±70 and 438±57) as compared to the C57BL/6 mice fed low or high fat diets (AUC mmol/L х min = 251±27 and 245±43). Arterial stiffness was determined by Doppler pulse wave velocity analysis of the femoral artery. Pulse wave velocity was increased in APN KO mice fed a high fat diet relative to those fed the low fat diet (12.56±0.78 cm/s vs 9.47±0.95 cm/s, p=0.0035; n=8-10). Pulse wave velocity was not different between C57BL/6 control mice on the low or high fat diets (10.63±0.73 cm/s and 10.86±0.50 cm/s), thus revealing that only mice deficient in adiponectin developed arterial stiffness in response to high fat diet. Conclusions: Potentiation of the vascular stiffness in diet-induced obese APN KO mice indicates that adiponectin has a role in modulating vascular structure and the APN KO mouse models the vascular changes that occur in human obesity and metabolic disorders. Morphometric analysis of the aortic tissues for vessel thickness and expression of extracellular proteins will further validate the potential role of adiponectin on the maintenance of arterial elasticity in addition to its known effect on eNOS mediated vasoprotection.


Sign in / Sign up

Export Citation Format

Share Document