Role of plasma cholesterol in determining glucose tolerance

1983 ◽  
Vol 38 (5) ◽  
pp. 817-818
Author(s):  
M Fields ◽  
S Reiser ◽  
J C Smith
Keyword(s):  
Glucose Tolerance ◽  
Plasma Cholesterol

scholarly journals The Aging Vasculature: Glucose Tolerance, Hypoglycemia and the Role of the Serum Response Factor

2021 ◽  
Vol 8 (5) ◽  
pp. 58
Author(s):  
Hazel Aberdeen ◽  
Kaela Battles ◽  
Ariana Taylor ◽  
Jeranae Garner-Donald ◽  
Ana Davis-Wilson ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Molecular Mechanisms ◽  
Serum Response Factor ◽  
Response Factor ◽  
Homeostatic Control ◽  
Older Americans ◽  
The Subject ◽  
Serum Response

The fastest growing demographic in the U.S. at the present time is those aged 65 years and older. Accompanying advancing age are a myriad of physiological changes in which reserve capacity is diminished and homeostatic control attenuates. One facet of homeostatic control lost with advancing age is glucose tolerance. Nowhere is this more accentuated than in the high proportion of older Americans who are diabetic. Coupled with advancing age, diabetes predisposes affected subjects to the onset and progression of cardiovascular disease (CVD). In the treatment of type 2 diabetes, hypoglycemic episodes are a frequent clinical manifestation, which often result in more severe pathological outcomes compared to those observed in cases of insulin resistance, including premature appearance of biomarkers of senescence. Unfortunately, molecular mechanisms of hypoglycemia remain unclear and the subject of much debate. In this review, the molecular basis of the aging vasculature (endothelium) and how glycemic flux drives the appearance of cardiovascular lesions and injury are discussed. Further, we review the potential role of the serum response factor (SRF) in driving glycemic flux-related cellular signaling through its association with various proteins.

scholarly journals Adipocyte PU.1 knockout promotes insulin sensitivity in HFD-fed obese mice

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Denise E. Lackey ◽  
Felipe C. G. Reis ◽  
Roi Isaac ◽  
Rizaldy C. Zapata ◽  
Dalila El Ouarrat ◽  
...  
Keyword(s):  
Gene Expression ◽  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Target Genes ◽  
Obese Mice ◽  
Tissue Macrophage

Abstract Insulin resistance is a key feature of obesity and type 2 diabetes. PU.1 is a master transcription factor predominantly expressed in macrophages but after HFD feeding PU.1 expression is also significantly increased in adipocytes. We generated adipocyte specific PU.1 knockout mice using adiponectin cre to investigate the role of PU.1 in adipocyte biology, insulin and glucose homeostasis. In HFD-fed obese mice systemic glucose tolerance and insulin sensitivity were improved in PU.1 AKO mice and clamp studies indicated improvements in both adipose and liver insulin sensitivity. At the level of adipose tissue, macrophage infiltration and inflammation was decreased and glucose uptake was increased in PU.1 AKO mice compared with controls. While PU.1 deletion in adipocytes did not affect the gene expression of PPARg itself, we observed increased expression of PPARg target genes in eWAT from HFD fed PU.1 AKO mice compared with controls. Furthermore, we observed decreased phosphorylation at serine 273 in PU.1 AKO mice compared with fl/fl controls, indicating that PPARg is more active when PU.1 expression is reduced in adipocytes. Therefore, in obesity the increased expression of PU.1 in adipocytes modifies the adipocyte PPARg cistrome resulting in impaired glucose tolerance and insulin sensitivity.

scholarly journals Deletion of Cardiomyocyte Glycogen Synthase Kinase-3 Beta (GSK-3β) Improves Systemic Glucose Tolerance with Maintained Heart Function in Established Obesity

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1120 ◽  
Author(s):  
Manisha Gupte ◽  
Prachi Umbarkar ◽  
Anand Prakash Singh ◽  
Qinkun Zhang ◽  
Sultan Tousif ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Cardiac Function ◽  
Cardiac Dysfunction ◽  
Glycogen Synthase ◽  
Critical Role ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3 ◽  
Total Period ◽  
Gsk 3Β

Obesity is an independent risk factor for cardiovascular diseases (CVD), including heart failure. Thus, there is an urgent need to understand the molecular mechanism of obesity-associated cardiac dysfunction. We recently reported the critical role of cardiomyocyte (CM) Glycogen Synthase Kinase-3 beta (GSK-3β) in cardiac dysfunction associated with a developing obesity model (deletion of CM-GSK-3β prior to obesity). In the present study, we investigated the role of CM-GSK-3β in a clinically more relevant model of established obesity (deletion of CM-GSK-3β after established obesity). CM-GSK-3β knockout (GSK-3βfl/flCre+/−) and controls (GSK-3βfl/flCre−/−) mice were subjected to a high-fat diet (HFD) in order to establish obesity. After 12 weeks of HFD treatment, all mice received tamoxifen injections for five consecutive days to delete GSK-3β specifically in CMs and continued on the HFD for a total period of 55 weeks. To our complete surprise, CM-GSK-3β knockout (KO) animals exhibited a globally improved glucose tolerance and maintained normal cardiac function. Mechanistically, in stark contrast to the developing obesity model, deleting CM-GSK-3β in obese animals did not adversely affect the GSK-3αS21 phosphorylation (activity) and maintained canonical β-catenin degradation pathway and cardiac function. As several GSK-3 inhibitors are in the trial to treat various chronic conditions, including metabolic diseases, these findings have important clinical implications. Specifically, our results provide critical pre-clinical data regarding the safety of GSK-3 inhibition in obese patients.

DPP4 deletion in adipose tissue improves hepatic insulin sensitivity in diet-induced obesity

2020 ◽  
Vol 318 (5) ◽  
pp. E590-E599 ◽  
Author(s):  
Tania Romacho ◽  
Henrike Sell ◽  
Ira Indrakusuma ◽  
Diana Roehrborn ◽  
Tamara R. Castañeda ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Hepatic Insulin Sensitivity ◽  
Dipeptidyl Peptidase 4 ◽  
Diet Induced Obesity ◽  
Hepatic Fat ◽  
Igf Binding ◽  
Igf Binding Protein

Besides a therapeutic target for type 2 diabetes, dipeptidyl peptidase 4 (DPP4) is an adipokine potentially upregulated in human obesity. We aimed to explore the role of adipocyte-derived DPP4 in diet-induced obesity and insulin resistance with an adipose tissue-specific knockout (AT-DPP4-KO) mouse. Wild-type and AT-DPP4-KO mice were fed for 24 wk with a high fat diet (HFD) and characterized for body weight, glucose tolerance, insulin sensitivity by hyperinsulinemic-euglycemic clamp, and body composition and hepatic fat content. Image and molecular biology analysis of inflammation, as well as adipokine secretion, was performed in AT by immunohistochemistry, Western blot, real-time-PCR, and ELISA. Incretin levels were determined by Luminex kits. Under HFD, AT-DPP4-KO displayed markedly reduced circulating DPP4 concentrations, proving AT as a relevant source. Independently of glucose-stimulated incretin hormones, AT-DPP4-KO had improved glucose tolerance and hepatic insulin sensitivity. AT-DPP4-KO displayed smaller adipocytes and increased anti-inflammatory markers. IGF binding protein 3 (IGFBP3) levels were lower in AT and serum, whereas free IGF1 was increased. The absence of adipose DPP4 triggers beneficial AT remodeling with decreased production of IGFBP3 during HFD, likely contributing to the observed, improved hepatic insulin sensitivity.

scholarly journals Effects of whole-grain wheat, rye, and lignan supplementation on cardiometabolic risk factors in men with metabolic syndrome: a randomized crossover trial

2020 ◽  
Vol 111 (4) ◽  
pp. 864-876
Author(s):  
Anne K Eriksen ◽  
Carl Brunius ◽  
Mohsen Mazidi ◽  
Per M Hellström ◽  
Ulf Risérus ◽  
...  
Keyword(s):  
Risk Factors ◽  
Metabolic Syndrome ◽  
Glucose Tolerance ◽  
Gut Microbiota ◽  
Ldl Cholesterol ◽  
Oral Glucose ◽  
Microbiota Composition ◽  
Whole Grain ◽  
The Metabolic Syndrome

ABSTRACT Background A whole-grain (WG)–rich diet has shown to have potential for both prevention and treatment of the metabolic syndrome (MetS), which is a cluster of risk factors that increase the risk of type 2 diabetes and cardiovascular disease. Different WGs may have different health effects. WG rye, in particular, may improve glucose homeostasis and blood lipids, possibly mediated through fermentable dietary fiber and lignans. Recent studies have also suggested a crucial role of the gut microbiota in response to WG. Objectives The aim was to investigate WG rye, alone and with lignan supplements [secoisolariciresinol diglucoside (SDG)], and WG wheat diets on glucose tolerance [oral-glucose-tolerance test (OGTT)], other cardiometabolic outcomes, enterolignans, and microbiota composition. Moreover, we exploratively evaluated the role of gut microbiota enterotypes in response to intervention diets. Methods Forty men with MetS risk profile were randomly assigned to WG diets in an 8-wk crossover study. The rye diet was supplemented with 280 mg SDG at weeks 4–8. Effects of treatment were evaluated by mixed-effects modeling, and effects on microbiota composition and the role of gut microbiota as a predictor of response to treatment were analyzed by random forest plots. Results The WG rye diet (± SDG supplements) did not affect the OGTT compared with WG wheat. Total and LDL cholesterol were lowered (−0.06 and −0.09 mmol/L, respectively; P < 0.05) after WG rye compared with WG wheat after 4 wk but not after 8 wk. WG rye resulted in higher abundance of Bifidobacterium [fold-change (FC) = 2.58, P < 0.001] compared with baseline and lower abundance of Clostridium genus compared with WG wheat (FC = 0.54, P = 0.02). The explorative analyses suggest that baseline enterotype is associated with total and LDL-cholesterol response to diet. Conclusions WG rye, alone or with SDG supplementation, compared with WG wheat did not affect glucose metabolism but caused transient LDL-cholesterol reduction. The effect of WG diets appeared to differ according to enterotype. This trial was registered at www.clinicaltrials.gov as NCT02987595.

scholarly journals The PACAP-Regulated Gene Selenoprotein T Is Abundantly Expressed in Mouse and Human β-Cells and Its Targeted Inactivation Impairs Glucose Tolerance

Endocrinology ◽  
2013 ◽  
Vol 154 (10) ◽  
pp. 3796-3806 ◽  
Author(s):  
Gaëtan Prevost ◽  
Arnaud Arabo ◽  
Long Jian ◽  
Eddy Quelennec ◽  
Dorthe Cartier ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Redox Status ◽  
Human Islets ◽  
Mutant Mice ◽  
Wild Type ◽  
Β Cells ◽  
Cellular Processes ◽  
Insulin Promoter ◽  
Selenoprotein T

Selenoproteins are involved in the regulation of redox status, which affects several cellular processes, including cell survival and homeostasis. Considerable interest has arisen recently concerning the role of selenoproteins in the regulation of glucose metabolism. Here, we found that selenoprotein T (SelT), a new thioredoxin-like protein of the endoplasmic reticulum, is present at high levels in human and mouse pancreas as revealed by immunofluorescence and quantitative PCR. Confocal immunohistochemistry studies revealed that SelT is mostly confined to insulin- and somatostatin-producing cells in mouse and human islets. To elucidate the role of SelT in β-cells, we generated, using a Cre-Lox strategy, a conditional pancreatic β-cell SelT-knockout C57BL/6J mice (SelT-insKO) in which SelT gene disruption is under the control of the rat insulin promoter Cre gene. Glucose administration revealed that male SelT-insKO mice display impaired glucose tolerance. Although insulin sensitivity was not modified in the mutant mice, the ratio of glucose to insulin was significantly higher in the SelT-insKO mice compared with wild-type littermates, pointing to a deficit in insulin production/secretion in mutant mice. In addition, morphometric analysis showed that islets from SelT-insKO mice were smaller and that their number was significantly increased compared with islets from their wild-type littermates. Finally, we found that SelT is up-regulated by pituitary adenylate cyclase-activating polypeptide (PACAP) in β-pancreatic cells and that SelT could act by facilitating a feed-forward mechanism to potentiate insulin secretion induced by the neuropeptide. Our findings are the first to show that the PACAP-regulated SelT is localized in pancreatic β- and δ-cells and is involved in the control of glucose homeostasis.

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