scholarly journals Hyperglycaemia and reduced glucokinase expression in weanling offspring from dams maintained on a high-fat diet

2006 ◽  
Vol 95 (2) ◽  
pp. 391-396 ◽  
Author(s):  
Marlon E. Cerf ◽  
Christo J. Muller ◽  
Don F. Du Toit ◽  
Johan Louw ◽  
Sonia A. Wolfe-Coote
Keyword(s):  
Mrna Expression ◽  
High Fat Diet ◽  
Wistar Rats ◽  
Cell Function ◽  
Glycolytic Enzyme ◽  
High Fat ◽  
Β Cell ◽  
Β Cell Function ◽  
Fat Feeding ◽  
Cell Maintenance

High-fat feeding reduces the expression of GLUT-2 and the glycolytic enzyme glucokinase (GK). The transcription factor, pancreatic duodenal homeobox-1 (Pdx-1), is important for β-cell maintenance. The aim of the present study was to determine, in weanling Wistar rats, the effect of a maternal high-fat diet (HFD) during defined periods of gestation and lactation, on body weight, circulating glucose and insulin concentrations, and the expression of GLUT-2, GK and Pdx-1. At postnatal day 21, weights were recorded and glucose and insulin concentrations were measured. The expression levels for mRNA were quantified by LightCycler PCR. Pancreatic sections, immunostained for GLUT-2, GK or Pdx-1, were assessed by image analysis. Weanlings from dams fed an HFD throughout gestation were lighter, with heavier weanlings produced from dams fed an HFD throughout gestation and lactation. Both these groups of weanlings were normoglycaemic, all the others being hyperglycaemic. Hypoinsulinaemia was evident in weanlings from dams fed an HFD throughout gestation only and also for either the first week of lactation or throughout lactation. GLUT-2 mRNA expression was reduced and GLUT-2 immunoreactivity was increased in most of the weanlings. GK mRNA expression and immunoreactivity was reduced in most of the offspring. Pdx-1 mRNA expression was increased in weanlings from dams fed an HFD throughout both gestation and lactation and reduced in those from dams only fed a lactational HFD. Normal Pdx-1 immunoreactivity was found in all of the weanlings. A maternal HFD induces hyperglycaemia in weanlings concomitant with reduced GK expression which may compromise β-cell function.

scholarly journals MafB Is Important for Pancreatic β-Cell Maintenance under a MafA-Deficient Condition

2019 ◽  
Vol 39 (17) ◽  
Author(s):  
Gulibaikelamu Xiafukaiti ◽  
Shayida Maimaiti ◽  
Kiyohito Ogata ◽  
Akihiro Kuno ◽  
Takashi Kudo ◽  
...  
Keyword(s):  
High Fat Diet ◽  
Cell Function ◽  
Expression Patterns ◽  
High Fat ◽  
Β Cells ◽  
Β Cell ◽  
Double Knockout ◽  
Adult Mice ◽  
Pathological Conditions ◽  
Β Cell Function

ABSTRACT The pancreatic-islet-enriched transcription factors MafA and MafB have unique expression patterns in β cells in rodents. MafA is specifically expressed in β cells and is a key regulatory factor for maintaining adult β-cell function, whereas MafB plays an essential role in β-cell development during embryogenesis, and its expression in β cells gradually decreases and is restricted to α cells after birth in rodents. However, it was previously observed that MafB started to be reexpressed in insulin-positive (insulin+) β cells in MafA-deficient adult mice. To elucidate how MafB functions in the adult β cell under MafA-deficient conditions, we generated MafA and MafB double-knockout (A0B0) mice in which MafB was specifically deleted from β cells. As a result, the A0B0 mice became more vulnerable to diabetes under a high-fat diet (HFD) treatment, with impaired islet formation and a decreased number of insulin+ β cells because of increased β-cell apoptosis, indicating MafB can take part in the maintenance of adult β cells under certain pathological conditions.

scholarly journals Herring Milt and Herring Milt Protein Hydrolysate Are Equally Effective in Improving Insulin Sensitivity and Pancreatic Beta-Cell Function in Diet-Induced Obese- and Insulin-Resistant Mice

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 635
Author(s):  
Yanwen Wang ◽  
Sandhya Nair ◽  
Jacques Gagnon
Keyword(s):  
Insulin Resistance ◽  
High Fat Diet ◽  
Cell Function ◽  
Protein Hydrolysate ◽  
High Fat ◽  
Β Cell ◽  
Insulin Resistant ◽  
Β Cell Function ◽  
Casein Protein ◽  
Dietary Casein

Although genetic predisposition influences the onset and progression of insulin resistance and diabetes, dietary nutrients are critical. In general, protein is beneficial relative to carbohydrate and fat but dependent on protein source. Our recent study demonstrated that 70% replacement of dietary casein protein with the equivalent quantity of protein derived from herring milt protein hydrolysate (HMPH; herring milt with proteins being enzymatically hydrolyzed) significantly improved insulin resistance and glucose homeostasis in high-fat diet-induced obese mice. As production of protein hydrolysate increases the cost of the product, it is important to determine whether a simply dried and ground herring milt product possesses similar benefits. Therefore, the current study was conducted to investigate the effect of herring milt dry powder (HMDP) on glucose control and the associated metabolic phenotypes and further to compare its efficacy with HMPH. Male C57BL/6J mice on a high-fat diet for 7 weeks were randomized based on body weight and blood glucose into three groups. One group continued on the high-fat diet and was used as the insulin-resistant/diabetic control and the other two groups were given the high-fat diet modified to have 70% of casein protein being replaced with the same amount of protein from HMDP or HMPH. A group of mice on a low-fat diet all the time was used as the normal control. The results demonstrated that mice on the high-fat diet increased weight gain and showed higher blood concentrations of glucose, insulin, and leptin, as well as impaired glucose tolerance and pancreatic β-cell function relative to those on the normal control diet. In comparison with the high-fat diet, the replacement of 70% dietary casein protein with the same amount of HMDP or HMPH protein decreased weight gain and significantly improved the aforementioned biomarkers, insulin sensitivity or resistance, and β-cell function. The HMDP and HMPH showed similar effects on every parameter except blood lipids where HMDP decreased total cholesterol and non-HDL-cholesterol levels while the effect of HMPH was not significant. The results demonstrate that substituting 70% of dietary casein protein with the equivalent amount of HMDP or HMPH protein protects against obesity and diabetes, and HMDP is also beneficial to cholesterol homeostasis.

scholarly journals The Clock GeneRev-erbα Regulates Pancreatic β-Cell Function: Modulation by Leptin and High-Fat Diet

Endocrinology ◽  
2012 ◽  
Vol 153 (2) ◽  
pp. 592-601 ◽  
Author(s):  
Elaine Vieira ◽  
Laura Marroquí ◽  
Thiago M. Batista ◽  
Ernesto Caballero-Garrido ◽  
Everardo M. Carneiro ◽  
...  
Keyword(s):  
High Fat Diet ◽  
Cell Function ◽  
Pancreatic Β Cell ◽  
High Fat ◽  
Β Cell ◽  
Β Cell Function

scholarly journals Maternal high-fat diet impairs glucose metabolism, β-cell function and proliferation in the second generation of offspring rats

2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Yan-Hong Huang ◽  
Ting-Ting Ye ◽  
Chong-Xiao Liu ◽  
Lei Wang ◽  
Yuan-Wen Chen ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
High Fat Diet ◽  
Second Generation ◽  
Cell Function ◽  
High Fat ◽  
Β Cell ◽  
Β Cell Function

scholarly journals TRPM7 is a critical regulator of pancreatic endocrine development and high-fat diet-induced β-cell proliferation

Development ◽  
2021 ◽  
Author(s):  
Molly K. Altman ◽  
Charles M. Schaub ◽  
Matthew T. Dickerson ◽  
Karolina E. Zaborska ◽  
Prasanna K. Dadi ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Glucose Tolerance ◽  
High Fat Diet ◽  
Transient Receptor Potential ◽  
Cell Function ◽  
Cell Mass ◽  
Transient Receptor Potential Channels ◽  
High Fat ◽  
Β Cell ◽  
Β Cell Function

The melastatin subfamily of the transient receptor potential channels (TRPM) are regulators of pancreatic β-cell function. TRPM7 is the most abundant islet TRPM channel; however, the role of TRPM7 in β-cell function has not been determined. Here, we utilized various spatiotemporal transgenic mouse models to investigate how TRPM7 knockout influences pancreatic endocrine development, proliferation, and function. Ablation of TRPM7 within pancreatic progenitors reduced pancreatic size, α-cell and β-cell mass. This resulted in modestly impaired glucose tolerance. However, TRPM7 ablation following endocrine specification or in adult mice did not impact endocrine expansion or glucose tolerance. As TRPM7 regulates cell proliferation, we assessed how TRPM7 influences β-cell hyperplasia under insulin resistant conditions. β-cell proliferation induced by high-fat diet was significantly decreased in TRPM7-deficient β-cells. The endocrine roles of TRPM7 may be influenced by cation flux through the channel, and indeed we find that TRPM7 ablation alters β-cell Mg2+ and reduces the magnitude of elevation in β-cell Mg2+ during proliferation. Together, these findings reveal that TRPM7 controls pancreatic development and β-cell proliferation, which is likely due to regulation of Mg2+ homeostasis.

GLP-1 preserves β cell function via improvement on islet insulin signaling in high fat diet feeding mice

Neuropeptides ◽  
2021 ◽  
Vol 85 ◽  
pp. 102110
Author(s):  
Heng Yang ◽  
Shuo Wang ◽  
Yingchun Ye ◽  
Min Xie ◽  
Yubin Li ◽  
...  
Keyword(s):  
Insulin Signaling ◽  
High Fat Diet ◽  
Cell Function ◽  
High Fat ◽  
Β Cell ◽  
Β Cell Function

scholarly journals Inactivation of the dual Bmp/Wnt inhibitor Sostdc1 enhances pancreatic islet function

2012 ◽  
Vol 303 (6) ◽  
pp. E752-E761 ◽  
Author(s):  
Kathryn D. Henley ◽  
Kimberly A. Gooding ◽  
Aris N. Economides ◽  
Maureen Gannon
Keyword(s):  
Insulin Secretion ◽  
Glucose Homeostasis ◽  
High Fat Diet ◽  
Cell Function ◽  
Metabolic Stress ◽  
Islet Function ◽  
High Fat ◽  
Β Cell ◽  
Β Cell Function ◽  
Bmp Pathway

Current endeavors in the type 2 diabetes (T2D) field include gaining a better understanding of extracellular signaling pathways that regulate pancreatic islet function. Recent data suggest that both Bmp and Wnt pathways are operative in pancreatic islets and play a positive role in insulin secretion and glucose homeostasis. Our laboratory found the dual Bmp and Wnt antagonist Sostdc1 to be upregulated in a mouse model of islet dysmorphogenesis and nonimmune-mediated lean diabetes. Because Bmp signaling has been proposed to enhance β-cell function, we evaluated the role of Sostdc1 in adult islet function using animals in which Sostdc1 was globally deleted. While Sostdc1-null animals exhibited no pancreas development phenotype, a subset of mutants exhibited enhanced insulin secretion and improved glucose homeostasis compared with control animals after 12-wk exposure to high-fat diet. Loss of Sostdc1 in the setting of metabolic stress results in altered expression of Bmp-responsive genes in islets but did not affect expression of Wnt target genes, suggesting that Sostdc1 primarily regulates the Bmp pathway in the murine pancreas. Furthermore, our data indicate that removal of Sostdc1 enhances the downregulation of the closely related Bmp inhibitors Ctgf and Gremlin in islets after 8-wk exposure to high-fat diet. These data imply that Sostdc1 regulates expression of these inhibitors and provide a means by which Sostdc1-null animals show enhanced insulin secretion and glucose homeostasis. Our studies provide insights into Bmp pathway regulation in the endocrine pancreas and reveal new avenues for improving β-cell function under metabolic stress.

scholarly journals Leptin restores the insulinotropic effect of exenatide in a mouse model of type 2 diabetes with increased adiposity induced by streptozotocin and high-fat diet

2014 ◽  
Vol 307 (8) ◽  
pp. E712-E719 ◽  
Author(s):  
Takeru Sakai ◽  
Toru Kusakabe ◽  
Ken Ebihara ◽  
Daisuke Aotani ◽  
Sachiko Yamamoto-Kataoka ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Triglyceride Level ◽  
High Fat Diet ◽  
Receptor Agonist ◽  
Cell Function ◽  
High Fat ◽  
Β Cell ◽  
Β Cell Function ◽  
Insulinotropic Effect

Leptin may reduce pancreatic lipid deposition, which increases with progression of obesity and can impair β-cell function. The insulinotropic effect of glucagon-like peptide-1 (GLP-1) and the efficacy of GLP-1 receptor agonist are reduced associated with impaired β-cell function. In this study, we examined whether leptin could restore the efficacy of exenatide, a GLP-1 receptor agonist, in type 2 diabetes with increased adiposity. We chronically administered leptin (500 μg·kg−1·day−1) and/or exenatide (20 μg·kg−1·day−1) for 2 wk in a mouse model of type 2 diabetes with increased adiposity induced by streptozotocin and high-fat diet (STZ/HFD mice). The STZ/HFD mice exhibited hyperglycemia, overweight, increased pancreatic triglyceride level, and reduced glucose-stimulated insulin secretion (GSIS); moreover, the insulinotropic effect of exenatide was reduced. However, leptin significantly reduced pancreatic triglyceride level, and adding leptin to exenatide (LEP/EX) remarkably enhanced GSIS. These results suggested that the leptin treatment restored the insulinotropic effect of exenatide in the mice. In addition, LEP/EX reduced food intake, body weight, and triglyceride levels in the skeletal muscle and liver, and corrected hyperglycemia to a greater extent than either monotherapy. The pair-feeding experiment indicated that the marked reduction of pancreatic triglyceride level and enhancement of GSIS by LEP/EX occurred via mechanisms other than calorie restriction. These results suggest that leptin treatment may restore the insulinotropic effect of exenatide associated with the reduction of pancreatic lipid deposition in type 2 diabetes with increased adiposity. Combination therapy with leptin and exenatide could be an effective treatment for patients with type 2 diabetes with increased adiposity.

Exercise improves glucose homeostasis that has been impaired by a high-fat diet by potentiating pancreatic β-cell function and mass through IRS2 in diabetic rats

2007 ◽  
Vol 103 (5) ◽  
pp. 1764-1771 ◽  
Author(s):  
Sunmin Park ◽  
Sang Mee Hong ◽  
Ji Eun Lee ◽  
So Ra Sung
Keyword(s):  
Cell Proliferation ◽  
High Fat Diet ◽  
Cell Function ◽  
Cell Mass ◽  
Diabetic Rats ◽  
Pancreatic Β Cell ◽  
High Fat ◽  
Β Cell ◽  
Igf I ◽  
Β Cell Function

In this study, we investigated the effects of a high-fat diet and exercise on pancreatic β-cell function and mass and its molecular mechanism in 90% pancreatectomized male rats. The pancreatectomized diabetic rats were given control diets (20% energy) or a high-fat (HF) diet (45% energy) for 12 wk. Half of each group was given regular exercise on an uphill treadmill at 20 m/min for 30 min 5 days/wk. HF diet lowered first-phase insulin secretion with glucose loading, whereas exercise training reversed this decrease. However, second-phase insulin secretion did not differ among the groups. Exercise increased pancreatic β-cell mass. This resulted from stimulated β-cell proliferation and reduced apoptosis, which is associated with potentiated insulin or IGF-I signaling through insulin receptor substrate-2 (IRS2) induction. Although the HF diet resulted in decreased proliferation and accelerated apoptosis by weakened insulin and IGF-I signaling from reduction of IRS2 protein, β-cell mass was maintained in HF rats just as much as in control rats via increased individual β-cell size and neogenesis from precursor cells. Consistent with the results of β-cell proliferation, pancreas duodenal homeobox-1 expression increased in the islets of rats in the exercise groups, and it was reduced the most in rats fed the HF diet. In conclusion, exercise combined with a moderate fat diet is a good way to maximize β-cell function and mass through IRS2 induction to alleviate the diabetic condition. This study suggests that dietary fat contents and exercise modulate β-cell function and mass to overcome insulin resistance in two different pathways.

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