scholarly journals Sex Differences in High Fat Diet-Induced Metabolic Alterations Correlate with Changes in the Modulation of GRK2 Levels

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1464 ◽  
Author(s):  
Alba C. Arcones ◽  
Marta Cruces-Sande ◽  
Paula Ramos ◽  
Federico Mayor ◽  
Cristina Murga

A differential sex-related sensitivity has been reported in obesity and insulin resistance-related cardio-metabolic diseases, with a lower incidence of these pathologies being observed in young females when compared to age-matched males. However, such relative protection is lost with age. The mechanisms underlying such sex and age-related changes in the susceptibility to diabetes and obesity are not fully understood. Herein, we report that the relative protection that is displayed by young female mice, as compared to male littermates, against some of the metabolic alterations that are induced by feeding a high fat diet (HFD), correlates with a lower upregulation of the protein levels of G protein-coupled receptor kinase (GRK2), which is a key regulator of both insulin and G protein-coupled receptor signaling, in the liver and adipose tissue. Interestingly, when the HFD is initiated in middle-aged (32 weeks) female mice, these animals are no longer protected and display a more overt obese and insulin-resistant phenotype, along with a more evident increase in the GRK2 protein levels in metabolically relevant tissues in such conditions. Our data suggest that GRK2 dosage might be involved in the sex and age-biased sensitivity to insulin resistance-related pathologies.

2019 ◽  
Vol 8 (3) ◽  
pp. 203-216 ◽  
Author(s):  
Anna C Simcocks ◽  
Kayte A Jenkin ◽  
Lannie O’Keefe ◽  
Chrishan S Samuel ◽  
Michael L Mathai ◽  
...  

Atypical cannabinoid compounds O-1602 and O-1918 are ligands for the putative cannabinoid receptors G protein-coupled receptor 55 and G protein-coupled receptor 18. The role of O-1602 and O-1918 in attenuating obesity and obesity-related pathologies is unknown. Therefore, we aimed to determine the role that either compound had on body weight and body composition, renal and hepatic function in diet-induced obesity. Male Sprague–Dawley rats were fed a high-fat diet (40% digestible energy from lipids) or a standard chow diet for 10 weeks. In a separate cohort, male Sprague–Dawley rats were fed a high-fat diet for 9 weeks and then injected daily with 5 mg/kg O-1602, 1 mg/kg O-1918 or vehicle (0.9% saline/0.75% Tween 80) for a further 6 weeks. Our data demonstrated that high-fat feeding upregulates whole kidney G protein receptor 55 expression. In diet-induced obesity, we also demonstrated O-1602 reduces body weight, body fat and improves albuminuria. Despite this, treatment with O-1602 resulted in gross morphological changes in the liver and kidney. Treatment with O-1918 improved albuminuria, but did not alter body weight or fat composition. In addition, treatment with O-1918 also upregulated circulation of pro-inflammatory cytokines including IL-1α, IL-2, IL-17α, IL-18 and RANTES as well as plasma AST. Thus O-1602 and O-1918 appear not to be suitable treatments for obesity and related comorbidities, due to their effects on organ morphology and pro-inflammatory signaling in obesity.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Can J Kiessling ◽  
Melissa Reichelt ◽  
John Headrick ◽  
Kevin Ashton

Cardioprotection against infarction and dysfunction in the myocardium involves G-protein-coupled receptor signalling orchestrated by specialised membrane microdomains termed caveolae. The caveolin protein family consist of three subtypes: caveolin-1, −2 and −3 (Cav1-3) and are responsible for the formation of caveolae and hypothesized to orchestrate cardioprotective signalling. Caveolin-3 deficiency and overexpression has been shown to attenuate and restore cardioprotection, respectively. Recently, a family of four related proteins known as cavins (Cavin1-4) have been implicated as regulators of caveolae formation and function. The roles and expression distribution of the cavin family is currently unknown in cardiac tissue. In this study hearts were isolated from 8, 16, 32 and 48 week male and female mice and subjected to normoxic perfusion (80 min) or ischemic stress (20 min global ischemia, 60 min reperfusion). RT-qPCR was used to assess differential gene expression of caveolin and cavin subtypes across these ages in both sexes. Decreased post-ischemic pressure development and increased LDH release were observed in 32 and 48 week old relative to 8 week old male hearts hearts, indicative of age-related loss of ischemic tolerance. Females showed greater tolerance to ischemia at 32 and 48 week old hearts when compared to male counterparts. In normoxic male 48 week old hearts, Cav1,-2,-3 and Cavin1 were significantly repressed, whilst post-ischemic male 48 week old hearts demonstrated significant repression of Cav3 and Cavin1 only. Normoxic female hearts showed no significant changes in caveolin and cavin transcript expression over the aging time course. However, post-ischemic female 48 week old hearts showing significant down-regulation of Cav3 only. Taken together, alterations in caveolin and cavin expression may contribute to the age-related loss of ischemic tolerance and G-protein-coupled receptor-mediated protection in aging male and female mice hearts.


Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Hanh T Tran ◽  
John J Gildea ◽  
Robin A Felder

G protein-coupled receptor kinase 4 (GRK4) is known to negatively regulate the dopamine-1 receptor (D 1 R) in human renal proximal tubule cells (RPTC) leading to reduced sodium excretion. c-Myc is a transcription factor involved in positive regulation of G protein-coupled receptor kinase 4 (GRK4). Protein phosphatase 2A (PP2A) inhibits c-Myc by dephosphorylating a residue that normally stabilizes c-Myc. We have previously shown that stimulation of the natriuretic D 1 R in RPTC led to an increased ratio of PP2A/c-Myc binding. Treatment with PMA (protein kinase C inhibitor) led to a decreased PP2A/c-Myc ratio and a lack of cAMP accumulation after stimulation with fenoldopam (FEN, D 1 R agonist). We hypothesized that PP2A plays a key role in regulating natriuresis and that perturbation of PP2A would directly have effects on protein levels of c-Myc, the ratio of PP2A/c-Myc, and the accumulation of cAMP. We used normal RPTCs (nRPTC) and RPTCs that have an uncoupled D 1 R that no longer stimulates adenylyl cyclase (uRPTC). Inhibition of PP2A in uRPTCs with okadaic acid (OA, 100nM, 3 hr) caused an increase in c-Myc protein levels (97.8% ± 18.9 SEM; n=6; p<0.05 (1.44 / 0.73 RFU)), a decrease in the PP2A/c-Myc ratio (-81.8% ± 1.5 SEM; n=6; p<0.05 (1.42 /7.82 RFU)), and a lack of cAMP accumulation upon treatment with SKF38393 (a D 1 R agonist similar to FEN). Activation of PP2A with FTY720 (PP2A activator, 10μM, 3hr) caused a decrease in c-Myc protein levels (- 85.4% ± 2.3 SEM; n=6; p<0.005 (0.11/ 0.73 RFU)), an increase in the PP2A/c-Myc binding ratio by 345.3% ± 90.3 SEM; n=6; p<0.01 (34.82/ 7.82 RFU), and an increase in cAMP accumulation upon stimulation with SKF38393 (94.0% ± 12.4 SEM; n=3; p<0.05 (9.04/4.66 pmole cAMP/mg protein) compared to VEH. In summary, the D 1 R coupling defect found in uRPTCs was restored through activation of PP2A and inhibition of c-Myc. We conclude that PP2A interacts with c-Myc to regulate the natriuretic effect of the D 1 R providing additional insight into the intracellular regulatory events surrounding sodium excretion.


Author(s):  
Vanesa Izquierdo ◽  
Verónica Palomera-Ávalos ◽  
Mercè Pallàs ◽  
Christian Griñán-Ferré

Environmental factors as maternal high-fat diet (HFD) intake can increase the risk of age-related cognitive decline in adult offspring. The epigenetic mechanisms are a possible link between diet effect and neurodegeneration across generations. Here, we found a significant decrease in triglyceride levels in a high-fat diet with resveratrol HFD+RV group and the offspring. Firstly, we obtained better cognitive performance in HFD+RV groups and their offspring. Molecularly, a significant increase in 5-mC levels, as well as increased gene expression of Dnmt1 and Dnmt3a in HFD+RV F1 group, were found. Furthermore, a significantly increased of m6A levels in HFD+RV F1 were found, and there were changes in gene expression of its enzymes (Mettl3 and Fto). Moreover, we found a decrease in gene expression levels of pro-inflammatory markers such as Il1-&beta;, Il-6, Tnf-&alpha;, Cxcl-10, Mcp-1 and Tgf-&beta;1 in HFD+RV and HFD+RV F1 groups. Moreover, there was increased gene expression of neurotrophins such as Ngf and Nt3 and its receptors TrkA and TrkB. Likewise, an increase in protein levels of BDNF and p-Akt in HFD+RV F1 was found. These results suggest that maternal RV supplementation under HFD intake prevents cognitive decline in SAMP8 adult offspring, promoting a reduction in triglycerides and leptin plasma levels, changes in the pro-inflammatory profile, restoring the epigenetic landscape as well as synaptic plasticity.


Hepatology ◽  
2020 ◽  
Vol 72 (6) ◽  
pp. 2077-2089 ◽  
Author(s):  
Helen H. Wang ◽  
Ornella Bari ◽  
Christopher K. Arnatt ◽  
Min Liu ◽  
Piero Portincasa ◽  
...  

2016 ◽  
Vol 118 (7) ◽  
pp. 1116-1124 ◽  
Author(s):  
Giuseppe Rengo ◽  
Gennaro Pagano ◽  
Pasquale Perrone Filardi ◽  
Grazia Daniela Femminella ◽  
Valentina Parisi ◽  
...  

2005 ◽  
Vol 64 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Claire J. Stocker ◽  
Jonathan R. S. Arch ◽  
Michael A. Cawthorne

A number of epidemiological studies worldwide have demonstrated a relationship between poor early growth and an increased susceptibility to insulin resistance, visceral obesity, type 2 diabetes and other features of the metabolic syndrome in adulthood. However, the mechanistic basis of this relationship and the relative roles of genes and the environment remain a subject of debate. The ‘thrifty phenotype’ hypothesis proposes that poor fetal nutrition leads to programming of metabolism and an adult phenotype that is adapted to poor but not plentiful nutrition. The maternal reduced-protein rat model has been used to examine the importance of the maternal environment in determining susceptibility to adult disease. Pregnant and lactating rat dams are fed a diet containing 80 g protein/kg as compared with 200 g protein/kg, which leads to growth restriction in utero. Offspring of low-protein dams have increased susceptibility to diabetes, insulin resistance and hypertension when fed a palatable high-fat diet that promotes obesity. Administration of leptin during pregnancy and lactation to these protein-restricted dams produces offspring that have increased metabolic rate and do not become obese or insulin resistant when fed on a high-fat diet. Increased glucocorticoid exposure, particularly during late gestation, has been linked with insulin resistance in adulthood. High levels of fetal glucocorticoids may result from a decreased activity of placental 11β-hydroxysteroid dehydrogenase (11β-HSD) type 2, which normally protects the fetus from high maternal glucocorticoid levels. Leptin administration to protein-restricted dams inhibits the suppression of 11β-HSD-2 and may be one mechanism by which the metabolic syndrome is prevented.


2017 ◽  
Vol 232 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Dawn E W Livingstone ◽  
Emma M Di Rollo ◽  
Tracy C-S Mak ◽  
Karen Sooy ◽  
Brian R Walker ◽  
...  

5α-Reductases irreversibly catalyse A-ring reduction of pregnene steroids, including glucocorticoids and androgens. Genetic disruption of 5α-reductase 1 in male mice impairs glucocorticoid clearance and predisposes to glucose intolerance and hepatic steatosis upon metabolic challenge. However, it is unclear whether this is driven by changes in androgen and/or glucocorticoid action. Female mice with transgenic disruption of 5α-reductase 1 (5αR1-KO) were studied, representing a ‘low androgen’ state. Glucocorticoid clearance and stress responses were studied in mice aged 6 months. Metabolism was assessed in mice on normal chow (aged 6 and 12 m) and also in a separate cohort following 1-month high-fat diet (aged 3 m). Female 5αR1-KO mice had adrenal suppression (44% lower AUC corticosterone after stress), and upon corticosterone infusion, accumulated hepatic glucocorticoids (~27% increased corticosterone). Female 5αR1-KO mice aged 6 m fed normal chow demonstrated insulin resistance (~35% increased area under curve (AUC) for insulin upon glucose tolerance testing) and hepatic steatosis (~33% increased hepatic triglycerides) compared with controls. This progressed to obesity (~12% increased body weight) and sustained insulin resistance (~38% increased AUC insulin) by age 12 m. Hepatic transcript profiles supported impaired lipid β-oxidation and increased triglyceride storage. Female 5αR1-KO mice were also predisposed to develop high-fat diet-induced insulin resistance. Exaggerated predisposition to metabolic disorders in female mice, compared with that seen in male mice, after disruption of 5αR1 suggests phenotypic changes may be underpinned by altered metabolism of glucocorticoids rather than androgens.


Sign in / Sign up

Export Citation Format

Share Document