scholarly journals Loss of intestinal ChREBP impairs absorption of dietary sugars and prevents glycemic excursion curves

2021 ◽  
Author(s):  
Wafa Charifi ◽  
Veronique Fauveau ◽  
Laura Francese ◽  
Alexandra Grosfeld ◽  
Maude Le Gall ◽  
...  
Keyword(s):  
Systemic Circulation ◽  
Oral Glucose ◽  
Peripheral Tissues ◽  
Nonalcoholic Fatty Liver ◽  
Fructose Malabsorption ◽  
The Metabolic Syndrome ◽  
Gut Epithelium ◽  
Dietary Sugar ◽  
Underlying Mechanisms ◽  
Dietary Sugars

Increased sugar consumption is a risk factor for features of the metabolic syndrome including obesity, hypertriglyceridemia, insulin resistance, diabetes, and nonalcoholic fatty liver disease. The gut epithelium, which plays a central role in dietary sugar digestion, absorption and metabolism has emerged a key actor of metabolic disorders. While the transcription factor ChREBP (Carbohydrate response element binding protein) has been established as a key player of the adaptive reprograming of cellular metabolism in various tissues upon glucose or fructose challenge, its specific contribution to the regulation of blood glucose upon dietary sugar intake was not previously addressed. We demonstrate here that ChREBP is abundantly expressed in the proximal gut epithelium, where carbohydrate digestion and absorption primarily occur and in particular L cells, which produce the glucoincretin GLP-1. The inducible deletion of ChREBP specifically in the mouse gut epithelium (ChΔGUT mice) resulted in the reduction of early glycemic excursion upon oral glucose load. Surprisingly, despite being associated with reduced GLP-1 production, loss of gut ChREBP activity significantly dampened glucose transepithelial flux, and thereby delayed glucose distribution to peripheral tissues. Among the underlying mechanisms, we unveil that ChΔGUT mice show an impaired expression of key intestinal hexose (glucose, galactose, fructose) transporters and metabolic enzymes as well as brush border dissacharidases. In agreement, intestinal ChREBP deficiency was accompanied by a precocious intolerance to both high-lactose and high-sucrose diets concomitant with mild galactose and severe fructose malabsorption syndromes. Altogether, our study demonstrates that, by transcriptionally orchestrating local digestion and absorption of dietary sugars, ChREBP activity in the mouse gut epithelium controls glucose appearance rate into systemic circulation and prevents against intolerance to mono- and disaccharides.

scholarly journals Insulin Resistance, the Metabolic Syndrome, and Nonalcoholic Fatty Liver Disease

2005 ◽  
Vol 90 (3) ◽  
pp. 1578-1582 ◽  
Author(s):  
F. Angelico ◽  
M. Del Ben ◽  
R. Conti ◽  
S. Francioso ◽  
K. Feole ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
Oral Glucose ◽  
Nonalcoholic Fatty Liver ◽  
Insulin Resistant ◽  
The Metabolic Syndrome

Background/Aims: An association of nonalcoholic fatty liver disease with the insulin-resistant metabolic syndrome has been suggested. The aim of the study was to assess the association of fatty liver to different degrees of insulin resistance and secretion. Methods and Results: The study was performed in 308 alcohol- and virus-negative consecutive patients attending a metabolic clinic, who underwent a complete clinical and biochemical work-up including oral glucose tolerance test and routine liver ultrasonography. Steatosis was graded as absent/mild, moderate, and severe. In nondiabetic subjects, a progressive (P < 0.05) increase in mean homeostasis model of insulin resistance was recorded from the group without steatosis to the groups with mild/moderate and severe steatosis. Severe steatosis was associated with the clustering of the five clinical and biochemical features proposed for the clinical diagnosis of the metabolic syndrome. Subjects with the metabolic syndrome with a more pronounced insulin resistance had a higher prevalence of severe steatosis (P < 0.01) compared with those with homeostasis model of insulin resistance below the median. Conclusions: The findings stress the heterogeneous presentation of patients with the metabolic syndrome when the diagnosis is based on the broad Adult Treatment Panel III clinical criteria and demonstrate that those who are more insulin resistant have a higher prevalence of severe steatosis.

Cardiovascular Risk in Children with Nonalcoholic Fatty Liver Disease (NAFLD)

2020 ◽  
Vol 16 ◽  
Author(s):  
Anna Bobrus- Chociej ◽  
Natalia Wasilewska ◽  
Marta Flisiak- Jackiewicz ◽  
Dariusz Lebensztejn
Keyword(s):  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
Current Knowledge ◽  
Scientific Evidence ◽  
Multisystem Disorder ◽  
Nonalcoholic Fatty Liver ◽  
Obesity Epidemic ◽  
The Metabolic Syndrome

: Nonalcoholic fatty liver disease (NAFLD) is a main cause of chronic liver disease in children. With the global obesity epidemic, the prevalence of NAFLD is increasing both in industrialized and developing countries. NAFLD is a multisystem disorder and a hepatic manifestation of the metabolic syndrome. Growing scientific evidence suggests that NAFLD is an independent risk factor for cardiovascular disease. This paper briefly describes the current knowledge concerning the association between NAFLD and cardiac dysfunction in children.

scholarly journals E3 ubiquitin ligase Grail promotes hepatic steatosis through Sirt1 inhibition

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Pei-Yao Liu ◽  
Cheng-Cheung Chen ◽  
Chia-Ying Chin ◽  
Te-Jung Liu ◽  
Wen-Chiuan Tsai ◽  
...  
Keyword(s):  
Hepatic Steatosis ◽  
Lipid Accumulation ◽  
Acid Synthesis ◽  
Sirtuin 1 ◽  
Nonalcoholic Fatty Liver ◽  
Expression Of Genes ◽  
Hepatic Fat ◽  
Underlying Mechanisms

AbstractIn obese adults, nonalcoholic fatty liver disease (NAFLD) is accompanied by multiple metabolic dysfunctions. Although upregulated hepatic fatty acid synthesis has been identified as a crucial mediator of NAFLD development, the underlying mechanisms are yet to be elucidated. In this study, we reported upregulated expression of gene related to anergy in lymphocytes (GRAIL) in the livers of humans and mice with hepatic steatosis. Grail ablation markedly alleviated the high-fat diet-induced hepatic fat accumulation and expression of genes related to the lipid metabolism, in vitro and in vivo. Conversely, overexpression of GRAIL exacerbated lipid accumulation and enhanced the expression of lipid metabolic genes in mice and liver cells. Our results demonstrated that Grail regulated the lipid accumulation in hepatic steatosis via interaction with sirtuin 1. Thus, Grail poses as a significant molecular regulator in the development of NAFLD.

scholarly journals Adipocyte, Immune Cells, and miRNA Crosstalk: A Novel Regulator of Metabolic Dysfunction and Obesity

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1004
Author(s):  
Sonia Kiran ◽  
Vijay Kumar ◽  
Santosh Kumar ◽  
Robert L Price ◽  
Udai P. Singh
Keyword(s):  
Insulin Resistance ◽  
Immune Response ◽  
T Cells ◽  
Immune Cells ◽  
Metabolic Diseases ◽  
Liver Disorder ◽  
Low Grade ◽  
Peripheral Tissues ◽  
Nonalcoholic Fatty Liver ◽  
Cytokines And Chemokines

Obesity is characterized as a complex and multifactorial excess accretion of adipose tissue (AT) accompanied with alterations in the immune response that affects virtually all age and socioeconomic groups around the globe. The abnormal accumulation of AT leads to several metabolic diseases, including nonalcoholic fatty liver disorder (NAFLD), low-grade inflammation, type 2 diabetes mellitus (T2DM), cardiovascular disorders (CVDs), and cancer. AT is an endocrine organ composed of adipocytes and immune cells, including B-Cells, T-cells and macrophages. These immune cells secrete various cytokines and chemokines and crosstalk with adipokines to maintain metabolic homeostasis and low-grade chronic inflammation. A novel form of adipokines, microRNA (miRs), is expressed in many developing peripheral tissues, including ATs, T-cells, and macrophages, and modulates the immune response. miRs are essential for insulin resistance, maintaining the tumor microenvironment, and obesity-associated inflammation (OAI). The abnormal regulation of AT, T-cells, and macrophage miRs may change the function of different organs including the pancreas, heart, liver, and skeletal muscle. Since obesity and inflammation are closely associated, the dysregulated expression of miRs in inflammatory adipocytes, T-cells, and macrophages suggest the importance of miRs in OAI. Therefore, in this review article, we have elaborated the role of miRs as epigenetic regulators affecting adipocyte differentiation, immune response, AT browning, adipogenesis, lipid metabolism, insulin resistance (IR), glucose homeostasis, obesity, and metabolic disorders. Further, we will discuss a set of altered miRs as novel biomarkers for metabolic disease progression and therapeutic targets for obesity.

scholarly journals Green Tea and Epigallocatechin Gallate (EGCG) for the Management of Nonalcoholic Fatty Liver Diseases (NAFLD): Insights into the Role of Oxidative Stress and Antioxidant Mechanism

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1076
Author(s):  
Guoyi Tang ◽  
Yu Xu ◽  
Cheng Zhang ◽  
Ning Wang ◽  
Huabin Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Fatty Liver ◽  
Green Tea ◽  
Liver Diseases ◽  
Randomized Clinical Trials ◽  
Epigallocatechin Gallate ◽  
Protective Effects ◽  
Nonalcoholic Fatty Liver ◽  
Nonalcoholic Fatty Liver Diseases ◽  
Underlying Mechanisms

Nonalcoholic fatty liver diseases (NAFLD) represent a set of liver disorders progressing from steatosis to steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma, which induce huge burden to human health. Many pathophysiological factors are considered to influence NAFLD in a parallel pattern, involving insulin resistance, oxidative stress, lipotoxicity, mitochondrial dysfunction, endoplasmic reticulum stress, inflammatory cascades, fibrogenic reaction, etc. However, the underlying mechanisms, including those that induce NAFLD development, have not been fully understood. Specifically, oxidative stress, mainly mediated by excessive accumulation of reactive oxygen species, has participated in the multiple NAFLD-related signaling by serving as an accelerator. Ameliorating oxidative stress and maintaining redox homeostasis may be a promising approach for the management of NAFLD. Green tea is one of the most important dietary resources of natural antioxidants, above which epigallocatechin gallate (EGCG) notably contributes to its antioxidative action. Accumulative evidence from randomized clinical trials, systematic reviews, and meta-analysis has revealed the beneficial functions of green tea and EGCG in preventing and managing NAFLD, with acceptable safety in the patients. Abundant animal and cellular studies have demonstrated that green tea and EGCG may protect against NAFLD initiation and development by alleviating oxidative stress and the related metabolism dysfunction, inflammation, fibrosis, and tumorigenesis. The targeted signaling pathways may include, but are not limited to, NRF2, AMPK, SIRT1, NF-κB, TLR4/MYD88, TGF-β/SMAD, and PI3K/Akt/FoxO1, etc. In this review, we thoroughly discuss the oxidative stress-related mechanisms involved in NAFLD development, as well as summarize the protective effects and underlying mechanisms of green tea and EGCG against NAFLD.

scholarly journals Oral Glucose Augments the Counterregulatory Hormone Response during Insulin-Induced Hypoglycemia in Humans1

2001 ◽  
Vol 86 (2) ◽  
pp. 645-648
Author(s):  
Rubina A. Heptulla ◽  
William V. Tamborlane ◽  
Tony Y.-Z. Ma ◽  
Fran Rife ◽  
Robert S. Sherwin.
Keyword(s):  
Plasma Glucose ◽  
Animal Studies ◽  
Healthy Adult ◽  
Systemic Circulation ◽  
Glucose Sensors ◽  
Oral Glucose ◽  
Adult Males ◽  
Hormone Response ◽  
Glucose Levels ◽  
Acute Hypoglycemia

It has been suggested that the counterregulatory hormone (CRH) response to acute hypoglycemia is triggered via glucose sensors situated in either the hypothalamus or the portohepatic area. If the latter were critical during hypoglycemia, one would anticipate that ingestion of glucose, by raising glucose levels in the portal circulation, should attenuate CRH responses previously described in animal studies. To evaluate the effect of raising portal, but not peripheral, glucose levels during insulin-induced hypoglycemia, we performed hypoglycemic clamp studies in five healthy adult males on two occasions. On one occasion, subjects received oral glucose (OG) (25 g) during hypoglycemia; and on one occasion, noncarbohydrate-containing drink of equal volume, while maintaining plasma glucose at 55 ± 2 mg/dL (3.08 mmol/L). As a result, there were no significant differences in systemic plasma glucose levels between the two hypoglycemic clamp studies, and basal CRH concentrations were also similar. As expected, there was a brisk rise in all CRH during the control (hypoglycemia+noncarbohydrate drink) study. In the experimental study, administration of OG (hypoglycemia+OG), to raise intraportal glucose levels during systemic hypoglycemia, did not attenuate CRH responses. Indeed, OG enhanced the rise in epinephrine, glucagon, and GH. Increases in cortisol and norepinephrine did not differ between the two studies. Therefore, our data suggest that increasing the level of glucose in the portal vein above that in the systemic circulation, during hypoglycemia, enhances (rather than suppresses) CRH responses. Thus, ingestion of glucose may reverse hypoglycemia directly by provision of substrate, as well as indirectly by stimulating counteregulatory mechanisms.

Nonalcoholic Fatty Liver Disease and Cardiovascular Disease: Overlapping Mechanisms

2021 ◽  
Author(s):  
Søren Møller ◽  
Nina Kimer ◽  
Thit Kronborg ◽  
Josephine Grandt ◽  
Jens Dahlgaard Hove ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
Severe Form ◽  
Nonalcoholic Fatty Liver ◽  
The Metabolic Syndrome ◽  
Increased Risk ◽  
Near Future

AbstractNonalcoholic fatty liver disease (NAFLD) denotes a condition with excess fat in the liver. The prevalence of NAFLD is increasing, averaging > 25% of the Western population. In 25% of the patients, NAFLD progresses to its more severe form: nonalcoholic steatohepatitis and >25% of these progress to cirrhosis following activation of inflammatory and fibrotic processes. NAFLD is associated with obesity, type 2 diabetes, and the metabolic syndrome and represents a considerable and increasing health burden. In the near future, NAFLD cirrhosis is expected to be the most common cause for liver transplantation. NAFLD patients have an increased risk of developing cardiovascular disease as well as liver-related morbidity. In addition, hepatic steatosis itself appears to represent an independent cardiovascular risk factor. In the present review, we provide an overview of the overlapping mechanisms and prevalence of NAFLD and cardiovascular disease.

scholarly journals Histologic and Metabolic Derangement in High-Fat, High-Fructose, and Combination Diet Animal Models

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jai Sun Lee ◽  
Dae Won Jun ◽  
Eun Kyung Kim ◽  
Hye Joon Jeon ◽  
Ho Hyun Nam ◽  
...  
Keyword(s):  
Animal Model ◽  
Body Weight Gain ◽  
Tolerance Test ◽  
Combination Group ◽  
Oral Glucose ◽  
High Fat ◽  
Metabolic Derangement ◽  
Fat Accumulation ◽  
Nonalcoholic Fatty Liver ◽  
High Fructose

Background. We used high-fat (HF), high-fructose (HFr), and combination diets to create a dietary animal model of nonalcoholic fatty liver disease (NAFLD). Comparison of both clinical phenotypes has not been well defined. The purpose of this study was to compare histologic and metabolic characteristics between diets in an animal model of NAFLD.Methods. NAFLD was induced in rats by feeding them HF, HFr, and combination (HF + HFr) diets for 20 weeks. The degree of intrahepatic fat accumulation, inflammation, and oxidative stress was evaluated. Metabolic derangements were assessed by the oral glucose tolerance test and the intrahepatic insulin signal pathway.Results. Body weight gain and intrahepatic fat accumulation were more prominent in the HF feeding group than in the HFr group. The expressions of NOX-4 and TLR-4 were higher in the HF and HFr combination groups than in the HF-only group. Other intrahepatic inflammatory markers, MCP-1, TNF-α, and endoplasmic reticulum stress markers, were the highest in the HF + HFr combination group. Although intrahepatic fat deposition was less prominent in the HFr diet model, intrahepatic inflammation was noted.Conclusions. Intrahepatic inflammation and metabolic derangements were more prominent in the HF and HFr combination model than in the HF monodiet model.

scholarly journals Investigation of possible underlying mechanisms behind water-induced glucose reduction in adults with high copeptin

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sofia Enhörning ◽  
Tiphaine Vanhaecke ◽  
Alberto Dolci ◽  
Erica T. Perrier ◽  
Olle Melander
Keyword(s):  
Urine Volume ◽  
Surrogate Marker ◽  
Oral Glucose ◽  
Glucose Lowering ◽  
Glucose Lowering Effect ◽  
Urine Cortisol ◽  
Underlying Mechanisms ◽  
Glucose Reduction ◽  
Water Supplementation ◽  
Pituitary Adrenal Axis

AbstractElevated copeptin, a surrogate marker of vasopressin, is linked to low water intake and increased diabetes risk. Water supplementation in habitual low-drinkers with high copeptin significantly lowers both fasting plasma (fp) copeptin and glucose. This study aims at investigating possible underlying mechanisms. Thirty-one healthy adults with high copeptin (> 10.7 pmol·L−1 (men), > 6.1 pmol−1 (women)) and 24-h urine volume of < 1.5L and osmolality of > 600 mOsm·kg−1 were included. The intervention consisted of addition of 1.5 L water daily for 6 weeks. Fp-adrenocorticotropic hormone (ACTH), fp-cortisol, 24-h urine cortisol, fasting and 2 h (post oral glucose) insulin and glucagon were not significantly affected by the water intervention. However, decreased (Δ baseline-6 weeks) fp-copeptin was significantly associated with Δfp-ACTH (r = 0.76, p < 0.001) and Δfp-glucagon (r = 0.39, p = 0.03), respectively. When dividing our participants according to baseline copeptin, median fp-ACTH was reduced from 13.0 (interquartile range 9.2–34.5) to 7.7 (5.3–9.9) pmol L−1, p = 0.007 in the top tertile of copeptin, while no reduction was observed in the other tertiles. The glucose lowering effect from water may partly be attributable to decreased activity in the hypothalamic–pituitary–adrenal axis.ClinicalTrials.gov: NCT03574688.

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