scholarly journals Impact of a Long-Term High Fat Diet on Bone Microarchitecture and Muscle Structure in Adult Male and Female Normal Mice

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Weston He ◽  
Trupti Trivedi ◽  
Gabriel Pagnotti ◽  
Sreemala Murthy ◽  
Yun She ◽  
...  

Background and Hypothesis: Hyperglycemia is a major source of disease and morbidity among the adult population. Prior studies correlate long-term high fat diet (HFD) mediated hyperglycemia with bone fragility and muscle weakness. Furthermore, the mechanism driving hyperglycemia between sexes are unknown. Our group previously showed that HFDs induced insulin resistance in male mice and glucose intolerance in female mice. This establishes the need to study the impact of long-term HFDs on the bones and muscles using an older cohort of both male and female mice. For that, we hypothesized a long-term HFD mediated hyperglycemia will change bone and muscle structures and impair their functions in adult male and female mice. Experimental Design or Project Methods: 22-week C57Bl6 mice were fed either a HFD or low fat diet (LFD) for 25 weeks. After euthanasia, bones and muscles were harvested and evaluated using MicroCT, histology, and mechanical testing. Statistical analysis was performed using GraphPad Prism with p<0.05 considered significant. Results: MicoCT data saw significant reductions to cortical thickness (p<0.05), bone mineral density (p<0.001), and increases to medullary area (p<0.05) among HFD males and females compared to LFD. HFD-males also experienced significant increase in cortical porosity (P<0.001) whereas no changes were noted in HFDfemales. Trabecular bone volume was relatively unchanged. HFD increased cortical osteoclast surface (p<0.001) for both sexes. Bone histology saw increased marrow adiposity among HFD-females (p<0.05). Muscle histology exhibited HFD-related reductions in myofiber diameter (p<0.001) for both sexes. Mechanical testing demonstrated reduced young’s modulus (p<0.05) and yield stress (p<0.05) among HFD mice, despite non-significant differences in ultimate strength. Conclusion and Potential Impact: The changes associated with a long-term HFD differed between sexes but still led to functional impairments of bone and muscle for both sexes, emphasizing the importance of looking further into the mechanisms responsible for these changes. This can potentially translate to the clinic in the treatment of musculoskeletal complications associated with HFDs.

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1999-P ◽  
Author(s):  
HYE LIM NOH ◽  
SUJIN SUK ◽  
RANDALL H. FRIEDLINE ◽  
KUNIKAZU INASHIMA ◽  
DUY A. TRAN ◽  
...  

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.


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

Hepatology ◽  
2009 ◽  
Vol 51 (6) ◽  
pp. 2234-2235 ◽  
Author(s):  
Adriana L. Burgueño ◽  
Julieta Carabelli ◽  
Silvia Sookoian ◽  
Carlos J. Pirola

2018 ◽  
Vol 315 (6) ◽  
pp. H1713-H1723 ◽  
Author(s):  
Lia E. Taylor ◽  
Ellen E. Gillis ◽  
Jacqueline B. Musall ◽  
Babak Baban ◽  
Jennifer C. Sullivan

Evidence supports a sex difference in the impact of a high-fat diet (HFD) on cardiovascular outcomes, with male experimental animals exhibiting greater increases in blood pressure (BP) than female experimental animals. The immune system has been implicated in HFD-induced increases in BP, and there is a sex difference in T-cell activation in hypertension. The goal of this study was to determine the impact of HFD on BP and aortic and renal T cell profiles in male and female Dahl salt-sensitive (DSS) rats. We hypothesized that male DSS rats would have greater increases in BP and T cell infiltration in response to a HFD compared with female DSS rats. BP was measured by tail-cuff plethysmography, and aortic and renal T cells were assessed by flow cytometric analysis in male and female DSS rats on a normal-fat diet (NFD) or HFD from 12 to 16 wk of age. Four weeks of HFD increased BP in male and female DSS rats to a similar degree. Increases in BP were accompanied by increased percentages of CD4+ T cells and T helper (Th)17 cells in both sexes, although male rats had more proinflammatory T cells. Percentages of renal CD3+ and CD4+ T cells as well as Th17 cells were increased in both sexes by the HFD, although the increase in CD3+ T cells was greater in male rats. HFD also decreased the percentage of aortic and renal regulatory T cells in both sexes, although female rats maintained more regulatory T cells than male rats regardless of diet. In conclusion, both male and female DSS rats exhibit BP sensitivity to a HFD; however, the mechanisms mediating HFD-induced increases in BP may be distinct as male rats exhibit greater increases in the percentage of proinflammatory T cells than female rats. NEW & NOTEWORTHY Our study demonstrates that male and female Dahl salt-sensitive rats exhibit similar increases in blood pressure to a high-fat diet and an increase in aortic and renal T cells. These results are in contrast to studies showing that female rats remain normotensive and/or upregulate regulatory T cells in response to hypertensive stimuli compared with male rats. Our data suggest that a 4-wk high-fat diet has sex-specific effects on the T cell profile in Dahl salt-sensitive rats.


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

2010 ◽  
Vol 26 (3) ◽  
pp. 291-302 ◽  
Author(s):  
Antònia Nadal-Casellas ◽  
Emilia Amengual-Cladera ◽  
Ana María Proenza ◽  
Isabel Lladó ◽  
Magdalena Gianotti

2018 ◽  
Vol 50 (8) ◽  
pp. 605-614
Author(s):  
Hong He ◽  
Katie Holl ◽  
Sarah DeBehnke ◽  
Chay Teng Yeo ◽  
Polly Hansen ◽  
...  

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.


2007 ◽  
Vol 293 (1) ◽  
pp. E121-E131 ◽  
Author(s):  
Michelle Lee ◽  
Andrea Kim ◽  
Streamson C. Chua ◽  
Silvana Obici ◽  
Sharon L. Wardlaw

To determine whether long-term melanocortinergic activation can attenuate the metabolic effects of a high fat diet, mice overexpressing an NH2-terminal POMC transgene that includes α- and γ3-MSH were studied on either a 10% low-fat diet (LFD) or 45% high-fat diet (HFD). Weight gain was modestly reduced in transgenic (Tg-MSH) male and female mice vs. wild type (WT) on HFD ( P < 0.05) but not LFD. Substantial reductions in body fat percentage were found in both male and female Tg-MSH mice on LFD ( P < 0.05) and were more pronounced on HFD ( P < 0.001). These changes occurred in the absence of significant feeding differences in most groups, consistent with effects of Tg-MSH on energy expenditure and partitioning. This is supported by indirect calorimetry studies demonstrating higher resting oxygen consumption and lower RQ in Tg-MSH mice on the HFD. Tg-MSH mice had lower fasting insulin levels and improved glucose tolerance on both diets. Histological and biochemical analyses revealed that hepatic fat accumulation was markedly reduced in Tg-MSH mice on the HFD. Tg-MSH also attenuated the increase in corticosterone induced by the HFD. Higher levels of Agrp mRNA, which might counteract effects of the transgene, were measured in Tg-MSH mice on LFD ( P = 0.02) but not HFD. These data show that long-term melanocortin activation reduces body weight, adiposity, and hepatic fat accumulation and improves glucose metabolism, particularly in the setting of diet-induced obesity. Our results suggest that long-term melanocortinergic activation could serve as a potential strategy for the treatment of obesity and its deleterious metabolic consequences.


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