Upper Small Intestinal Fatty Acid Sensing Improves Glucose Tolerance Through Suppression of Hepatic Glucose Production

2015 ◽  
Vol 39 (6) ◽  
pp. 547
Author(s):  
Paige V. Bauer ◽  
Sophie C. Hamr ◽  
Frank A. Duca ◽  
Brittany A. Rasmussen ◽  
Tony K.T. Lam
2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Yueh-Hsiung Kuo ◽  
Cheng-Hsiu Lin ◽  
Chun-Ching Shih

This study was to investigate the antidiabetic and antihyperlipidemic effects of (E)-3-[3, 4-dihydroxyphenyl-1-(piperidin-1-yl)prop-2-en-1-one] (36-13) (TS), one of caffeic acid amide derivatives, on high-fat (HF-) fed mice. The C57BL/6J mice were randomly divided into the control (CON) group and the experimental group, which was firstly fed a HF diet for 8 weeks. Then, the HF group was subdivided into four groups and was given TS orally (including two doses) or rosiglitazone (Rosi) or vehicle for 4 weeks. Blood, skeletal muscle, and tissues were examined by measuring glycaemia and dyslipidemia-associated events. TS effectively prevented HF diet-induced increases in the levels of blood glucose, triglyceride, insulin, leptin, and free fatty acid (FFA) and weights of visceral fa; moreover, adipocytes in the visceral depots showed a reduction in size. TS treatment significantly increased the protein contents of glucose transporter 4 (GLUT4) in skeletal muscle; TS also significantly enhanced Akt phosphorylation in liver, whereas it reduced the expressions of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase). Moreover, TS enhanced phosphorylation of AMP-activated protein kinase (phospho-AMPK) both in skeletal muscle and liver tissue. Therefore, it is possible that the activation of AMPK by TS resulted in enhanced glucose uptake in skeletal muscle, contrasting with diminished gluconeogenesis in liver. TS exhibits hypolipidemic effect by decreasing the expressions of fatty acid synthase (FAS). Thus, antidiabetic properties of TS occurred as a result of decreased hepatic glucose production by PEPCK and G6Pase downregulation and improved insulin sensitization. Thus, amelioration of diabetic and dyslipidemic state by TS in HF-fed mice occurred by regulation of GLUT4, G6Pase, and FAS and phosphorylation of AMPK.


Endocrinology ◽  
2013 ◽  
Vol 154 (1) ◽  
pp. 102-113 ◽  
Author(s):  
Meena Garg ◽  
Manikkavasagar Thamotharan ◽  
Yun Dai ◽  
Venu Lagishetty ◽  
Aleksey V. Matveyenko ◽  
...  

Enhanced de novo lipogenesis (DNL), an adult hepatic adaption, is seen with high carbohydrate or low-fat diets. We hypothesized that ad libitum intake after prenatal calorie restriction will result in adult-onset glucose intolerance and enhanced DNL with modified lipid metabolic gene expression profile. Stable isotopes were used in 15-month-old adult male rat offspring exposed to prenatal (IUGR), pre- and postnatal (IPGR), or postnatal (PNGR) caloric restriction vs. controls (CON). IUGR vs. CON were heavier with hepatomegaly but unchanged visceral white adipose tissue (WAT), glucose intolerant with reduced glucose-stimulated insulin secretion (GSIS), pancreatic β-cell mass, and total glucose clearance rate but unsuppressed hepatic glucose production. Liver glucose transporter (Glut) 1 and DNL increased with decreased hepatic acetyl-CoA carboxylase (ACC) and fatty acid synthase but increased WAT fatty acid transport protein-1 and peroxisomal proliferator-activated receptor-γ, resistin, and visfatin gene expression. In contrast, PNGR and IPGR were lighter, had reduced visceral WAT, and were glucose tolerant with unchanged hepatic glucose production but with increased GSIS, β-cell mass, glucose clearance rate, and WAT insulin receptor. Hepatic Glut1 and DNL were also increased in lean IPGR and PNGR with increased hepatic ACC, phosphorylated ACC, and pAMPK and reduced WAT fatty acid transport protein-1, peroxisomal proliferator-activated receptor-γ, and ACCα. We conclude the following: 1) the heavy, glucose-intolerant and insulin-resistant IUGR adult phenotype is ameliorated by postnatal caloric restriction; 2) increased DNL paralleling hepatic Glut1 is a biomarker of exposure to early caloric restriction rather than the adult metabolic status; 3) hepatic lipid enzyme expression reflects GSIS rather than DNL; and 4) WAT gene expression reflects an obesogenic vs. lean phenotype.


2021 ◽  
Author(s):  
Justine Lallement ◽  
Ilyès Raho ◽  
Gregory Merlen ◽  
Dominique Rainteau ◽  
Mikael Croyal ◽  
...  

Objectives: Ceramides have been shown as lipotoxic inducers, which can trigger apoptosis, inflammation and disturb numerous cell signalling pathways leading to metabolic disorders such as type 2 diabetes (T2D). In this study, we aimed to determine the role of de novo hepatic ceramide synthesis on energy and liver homeostasis in mice. Methods: In order to investigate hepatic role of de novo ceramides synthesis, we generated mice lacking serine palmitoyltransferase 2 (Sptlc2) in hepatocytes using the cre-lox system. SPTLC2 allows condensation of serine and palmitoylCoA and is the rate limiting-enzyme necessary for ceramide de novo synthesis. Sptlc2ΔHep and their littermate controls were fed with high fat diet (HFD) to induce metabolic disorders. Liver ceramides content and metabolic parameters as glucose tolerance, insulin sensitivity, and hepatic glucose production were assessed. As ceramides may have impact on bile acids (BA), we investigated BA pool composition, synthesis and transport. Finally, inflammation and apoptosis were measured in the liver using western blot analysis, pro-inflammatory cytokines expression level and immunohistochemistry. Results: Despite lower expression of hepatic Sptlc2, we observed an increased concentration of hepatic ceramides, especially C16:0-ceramide. Hepatic deletion of Sptlc2 in mice was also associated with an increased neutral sphingomyelinase 2 (nSmase2) expression, and a decreased sphingomyelin content in the liver. We showed that Sptlc2ΔHep mice are protected against body mass gain normally induced by HFD and displayed a decreased body fat mass. BA hydrophobicity was drastically decreased in Sptlc2ΔHep mice, and was associated with a defect in lipid absorption. In addition, an important increase of tauro-murocholic acid T-MCA in BA pool composition of Sptlc2ΔHep mice was associated with a downregulation of the nuclear bile acid receptor FXR target genes in ileum and liver. Sptlc2 deficiency also enhanced glucose tolerance and attenuated hepatic glucose production in an insulin-independent manner. Finally, Sptlc2 disruption promoted progressive development of hepatic fibrosis, apoptosis and inflammation in an age-related manner. Conclusion: Our data demonstrate for the first time a potential compensatory mechanism to regulate hepatic ceramides content from sphingomyelin hydrolysis. In addition, our results highlight the role of hepatic sphingolipid modulation on hepatic glucose production through bile acid composition changes.


2008 ◽  
Vol 56 (3) ◽  
pp. 567-573 ◽  
Author(s):  
Dana S. Hardin ◽  
Chul Ahn ◽  
Julie Rice ◽  
Mark Rice ◽  
Randall Rosenblatt

The incidence of diabetes is high in cystic fibrosis (CF) and is an important cause of morbidity and mortality. Understanding the pathophysiology is imperative. Studies have documented increased endogenous (mostly hepatic) glucose production (HGP) but have not distinguished the relative contribution of gluconeogenesis (GNG). The purpose of this study was to quantitate GNG, to determine its contribution to high HGP, and to measure insulin's suppression of GNG.We recruited 31 adult CF subjects (age, 26.2 ± 7.9 years; 12 female subjects) and quantified GNG by measuring the incorporation of 2H into the second and fifth carbons of glucose. Hepatic glucose production was measured using [6,6-2H2]glucose. Protein breakdown was measured using [1-13C]leucine. Data were compared with that from 11 healthy volunteers (age, 27.5 ± 7.0 years) who underwent both GNG and clamp studies. Thirteen CF subjects and all controls had a hyperinsulinemic euglycemic clamp during measures of GNG. Other measures included glucose tolerance and glucagon and cortisol levels.Rate of GNG was higher in CF subjects than controls and comprised a greater percentage of fasting HGP (GNG as percent of HGP: CF = 68%; controls = 44%; P = 0.034). Suppression of GNG by insulin was significantly lower in CF than in controls and was lower in CF subjects with abnormal glucose tolerance than in those with normal glucose tolerance. Gluconeogenesis correlated with protein breakdown.These studies suggest that high HGP in CF is mostly from elevated rates of GNG and that resistance to insulin's suppression of GNG may contribute to abnormal glucose tolerance in CF.


Endocrinology ◽  
2007 ◽  
Vol 148 (5) ◽  
pp. 2075-2084 ◽  
Author(s):  
Toshinori Aoyagi ◽  
Jun-ichi Birumachi ◽  
Masami Hiroyama ◽  
Yoko Fujiwara ◽  
Atsushi Sanbe ◽  
...  

Arginine-vasopressin (AVP) is known to be involved in maintaining glucose homeostasis, and AVP-resistance is observed in poorly controlled non-insulin-dependent diabetes mellitus subjects, resulting in a lowered plasma volume. Recently we reported that V1a vasopressin receptor-deficient (V1aR−/−) mice exhibited a decreased circulating blood volume and hypermetabolism of fat accompanied with impaired insulin-signaling. Here we further investigated the roles of the AVP/V1a receptor in regulating glucose homeostasis and plasma volume using V1aR−/− mice. The plasma glucose levels at the baseline or during a glucose tolerance test were higher in V1aR−/− than wild-type (WT) mice. Moreover, a hyperinsulinemic-euglycemic clamp revealed that the glucose infusion rate was significantly lower in V1aR−/− mice than in WT mice and that hepatic glucose production was higher in V1aR−/− mice than WT mice. In contrast to the increased hepatic glucose production, the liver glycogen content was decreased in the mutant mice. These results indicated that the mutant mice had impaired glucose tolerance. Furthermore, feeding V1aR−/− mice a high-fat diet accompanied by increased calorie intake resulted in significantly overt obesity in comparison with WT mice. In addition, we found that the circulating plasma volume and aldosterone level were decreased in V1aR−/− mice, although the plasma AVP level was increased. These results suggested that the effect of AVP on water recruitment was disturbed in V1aR−/− mice. Thus, we demonstrated that one of the AVP-resistance conditions resulting from deficiency of the V1a receptor leads to decreased plasma volume as well as impaired glucose homeostasis, which can progress to obesity under conditions of increased calorie intake.


2005 ◽  
Vol 98 (3) ◽  
pp. 930-939 ◽  
Author(s):  
Michael J. Christopher ◽  
Christian Rantzau ◽  
Glenn McConell ◽  
Bruce E. Kemp ◽  
Frank P. Alford

The separate impacts of the chronic diabetic state and the prevailing hyperglycemia on plasma substrates and hormones, in vivo glucose turnover, and ex vivo skeletal muscle (SkM) during exercise were examined in the same six dogs before alloxan-induced diabetes (prealloxan) and after 4–5 wk of poorly controlled hyperglycemic diabetes (HGD) in the absence and presence of ∼300-min phlorizin-induced (glycosuria mediated) normoglycemia (NGD). For each treatment state, the ∼15-h-fasted dog underwent a primed continuous 150-min infusion of [3-3H]glucose, followed by a 30-min treadmill exercise test (∼65% maximal oxygen capacity), with SkM biopsies taken from the thigh (vastus lateralis) before and after exercise. In the HGD and NGD states, preexercise hepatic glucose production rose by 130 and 160%, and the metabolic clearance rate of glucose (MCRg) fell by 70 and 37%, respectively, compared with the corresponding prealloxan state, but the rates of glucose uptake into peripheral tissues (Rdtissue) and total glycolysis (GF) were unchanged, despite an increased availability of plasma free fatty acid in the NGD state. Exercise-induced increments in hepatic glucose production, Rdtissue, and plasma-derived GF were severely blunted by ∼30–50% in the NGD state, but increments in MCRg remained markedly reduced by ∼70–75% in both diabetic states. SkM intracellular glucose concentrations were significantly elevated only in the HGD state. Although Rdtissue during exercise in the diabetic states correlated positively with preexercise plasma glucose and insulin and GF and negatively with preexercise plasma free fatty acid, stepwise regression analysis revealed that an individual's preexercise glucose and GF accounted for 88% of Rdtissue during exercise. In conclusion, the prevailing hyperglycemia in poorly controlled diabetes is critical in maintaining a sufficient supply of plasma glucose for SkM glucose uptake during exercise. During phlorizin-induced NGD, increments in both Rdtissue and GF are impaired due to a diminished fuel supply from plasma glucose and a sustained reduction in increments of MCRg.


Nutrients ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 120
Author(s):  
Hussein Herz ◽  
Yang Song ◽  
Yuanchao Ye ◽  
Liping Tian ◽  
Benjamin Linden ◽  
...  

Background/Aim: Given their widespread use and their notorious effects on the lining of gut cells, including the enteroendocrine cells, we explored if chronic exposure to non-steroidal anti-inflammatory drugs (NSAIDs) affects metabolic balance in a mouse model of NSAID-induced enteropathy. Method: We administered variable NSAIDs to C57Blk/6J mice through intragastric gavage and measured their energy balance, glucose hemostasis, and GLP-1 levels. We treated them with Exendin-9 and Exendin-4 and ran a euglycemic-hyperinsulinemic clamp. Results: Chronic administration of multiple NSAIDs to C57Blk/6J mice induces ileal ulcerations and weight loss in animals consuming a high-fat diet. Despite losing weight, NSAID-treated mice exhibit no improvement in their glucose tolerance. Furthermore, glucose-stimulated (glucagon-like peptide -1) GLP-1 is significantly attenuated in the NSAID-treated groups. In addition, Exendin-9—a GLP-1 receptor antagonist—worsens glucose tolerance in the control group but not in the NSAID-treated group. Finally, the hyper-insulinemic euglycemic clamp study shows that endogenous glucose production, total glucose disposal, and their associated insulin levels were similar among an ibuprofen-treated group and its control. Exendin-4, a GLP-1 receptor agonist, reduces insulin levels in the ibuprofen group compared to their controls for the same glucose exchange rates. Conclusions: Chronic NSAID use can induce small intestinal ulcerations, which can affect intestinal GLP-1 production, hepatic insulin sensitivity, and consequently, hepatic glucose production.


1989 ◽  
Vol 256 (5) ◽  
pp. E676-E681 ◽  
Author(s):  
N. L. Bodkin ◽  
B. L. Metzger ◽  
B. C. Hansen

The purpose of this study was to identify the relationship between basal hepatic glucose production (HGP) and peripheral insulin sensitivity as assessed by the hyperinsulinemic euglycemic clamp prior to and during the development of non-insulin-dependent (type 2) diabetes mellitus in rhesus monkeys. Twenty-six male monkeys (Macaca mulatta), including normal animals and monkeys in various phases of the development of spontaneous obesity-associated type 2 diabetes were studied. Fasting plasma glucose (FPG) and insulin (FIRI), basal HGP using a [3H]glucose infusion, and peripheral insulin sensitivity (as determined by the euglycemic clamp technique) were examined. The earliest change that could be detected was a significant reduction in peripheral insulin sensitivity accompanied by increased FIRI. These changes preceded a significant deterioration of glucose tolerance. Basal HGP changed in parallel with FPG (r = 0.90, P less than 0.001), becoming significantly elevated only when FPG rose to levels diagnostic of diabetes (greater than 140 mg/dl). Thus basal HGP and fasting glucose levels showed no significant changes early in the development of type 2 diabetes. We conclude that the early serial decreases in insulin sensitivity and progressive increases in FIRI, with or without decreased glucose tolerance, are prognostic of the future development of diabetes in obese monkeys, a longitudinal process that is also likely to be observed in most if not all obese humans progressing to diabetes.


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