Structural changes in endocrine pancreas of male Wistar rats due to chronic cola drink consumption. Role of PDX-1

Aim: The objective of this work was to analyze the structural changes of the pancreatic islets in rats, after 6 month consuming regular and light cola for 6 months. Also, we have analyzed the possible role of PDX-1 in that process. Finally, with the available knowledge, we propose a general working hypothesis that explains the succession of phenomena observed. Previously, we reported evidence showing that chronic cola consumption in rats impairs pancreatic metabolism of insulin and glucagon and produces some alterations typically observed in the metabolic syndrome, with an increase in oxidative stress. Of note It is worth mentioning that no apoptosis nor proliferation of islet cells could be demonstrated. In the present study, 36 male Wistar rats were divided into three groups to and given free access to freely drink regular cola (C), light cola (L), or water (W, control). We assessed the impact of the three different beverages in on glucose tolerance, lipid levels, creatinine levels and immunohistochemical changes addressed for the expression of insulin, glucagon, PDX-1 and NGN3 in islet cells, to evaluate the possible participation of PDX-1 in the changes observed in α and β cells after 6 months of treatment. Moreover, we assessed by stereological methods, the mean volume of islets (Vi) and three important variables: the fractional β -cell area, the cross-sectional area of alpha (A α-cell) and beta cells (A β-cell), and the number of β and α cell per body weight. Data were analyzed by two-way ANOVA followed by Bonferroni’s multiple t-test or by Kruskal-Wallis test, then followed by Dunn’s test (depending on distribution). Statistical significance was set at p<0.05. Cola drinking caused impaired glucose tolerance as well as fasting hyperglycemia (mean:148; CI:137–153; p<0.05 vs W) and an increase of in insulin immunolabeling (27.3±19.7; p<0.05 vs W and L). Immunohistochemical expression for PDX-1 was significantly high in C group compared to W (0.79±0.71; p<0.05). In this case, we observed cytoplasmatic and nuclear localization. Likewise, a mild but significant decrease of in Vi was detected after 6 months in C compared to W group (8.2±2.5; p<0.05). Also, we observed a significant decrease of in the fractional β cell area (78.2±30.9; p<0.05) compared to W. Accordingly, a reduced mean value of islet α and β cell number per body weight (0.05±0.02 and 0.08±0.04 respectively; both p<0.05) compared to W was detected. Interestingly, consumption of light cola increased the Vi (10.7±3.6; p<0.05) compared to W. In line with this, a decreased cross-sectional area of β-cells was observed after chronic consumption of both, regular (78.2±30.9; p<0.05) and light cola (110.5±24.3; p<0.05), compared to W. As for, NGN3, it was negative in all three groups. Our results support the idea that PDX-1 plays a key role in the dynamics of the pancreatic islets after chronic consumption of sweetened beverages. In this experimental model, the loss of islets cells might be attributed to autophagy, favored by the local metabolic conditions and oxidative stress.

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Could TDX-1 explain the changes observed in endocrine pancreas due to chronic cola drink consumption in rats? A global point of view

10.1101/2020.11.20.391060 ◽

2020 ◽

Author(s):

Gabriel Cao ◽

Julián González ◽

Juan P. Ortiz Fragola ◽

Angélica Muller ◽

Mariano Tumarkin ◽

...

Keyword(s):

Body Weight ◽

Glucose Tolerance ◽

Islet Cells ◽

Cross Sectional Area ◽

The Other ◽

Cell Area ◽

Sectional Area ◽

Β Cells ◽

Β Cell ◽

Cross Sectional

AbstractIn previous studies, we reported evidence showing that chronic cola consumption in rats impairs pancreatic metabolism of insulin and glucagon and produces some alterations typically observed in the metabolic syndrome (i.e, hyperglycemia, and hypertriglyceridemia) with an increase in oxidative stress. Of note, no apoptosis nor proliferation of islet cells could be demonstrated. In the present study, 36 male Wistar rats were divided in three groups to freely drink regular cola, light cola, or water (controls). We assessed the impact of the three different beverages in glucose tolerance, lipid levels, creatinine levels and immunohistochemical changes addressed for the expression of insulin, glucagon, PDX-1 and NGN3 in islet cells, to evaluate the possible participation of PDX-1 in the changes observed in α and β cells after 6 months of treatment. On the other hand, we assessed by stereological methods, the mean volume of islets (Vi) and three important variables, the fractional β-cell area, the cross-sectional area of alpha (A α-cell) and beta cells (A β-cell), and the number of β and α cell per body weight.Cola drinking caused impaired glucose tolerance as well as fasting hyperglycemia and increase of insulin immunolabeling. Immunohistochemical expression for PDX-1 was significantly high in regular cola consumption group compared to control. In this case, we observed cytoplasmatic and nuclear localization. Likewise, a mild but significant decrease of Vi was detected after 6 months of cola drink consumption compared with control group. Also, we observed a significant decrease of fractional β cell area compared with control rats. Accordingly, a reduced mean value of islet α and β cell number per body weight compared to control was detected. Interestingly, consumption of light cola increased the Vi compared to control. In line with this, a decreased cross-sectional area of β-cells was observed after chronic consumption of both, regular and light cola, compared to controls. On the other hand, NGN3 was negative in all three groups. Our results support for the first time, the idea that TDX-1 plays a key role in the dynamics of the pancreatic islets after chronic consumption of sweetened beverages. The loss of islets cells might be attributed to autophagy, favored by the local metabolic conditions.

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Unraveling the role of the ghrelin gene peptides in the endocrine pancreas

Journal of Molecular Endocrinology ◽

10.1677/jme-10-0019 ◽

2010 ◽

Vol 45 (3) ◽

pp. 107-118 ◽

Cited By ~ 62

Author(s):

Riccarda Granata ◽

Alessandra Baragli ◽

Fabio Settanni ◽

Francesca Scarlatti ◽

Ezio Ghigo

Keyword(s):

Pancreatic Islets ◽

Cell Biology ◽

Islet Cell ◽

Endocrine Pancreas ◽

Islet Cells ◽

Β Cells ◽

Β Cell ◽

Pancreatic Islet Cell ◽

Ghrelin Gene

The ghrelin gene peptides include acylated ghrelin (AG), unacylated ghrelin (UAG), and obestatin (Ob). AG, mainly produced by the stomach, exerts its central and peripheral effects through the GH secretagogue receptor type 1a (GHS-R1a). UAG, although devoid of GHS-R1a-binding affinity, is an active peptide, sharing with AG many effects through an unknown receptor. Ob was discovered as the G-protein-coupled receptor 39 (GPR39) ligand; however, its physiological actions remain unclear. The endocrine pancreas is necessary for glucose homeostasis maintenance. AG, UAG, and Ob are expressed in both human and rodent pancreatic islets from fetal to adult life, and the pancreas is the major source of ghrelin in the perinatal period. GHS-R1a and GPR39 expression has been shown in β-cells and islets, as well as specific binding sites for AG, UAG, and Ob. Ghrelin colocalizes with glucagon in α-islet cells, but is also uniquely expressed in ε-islet cells, suggesting a role in islet function and development. Indeed, AG, UAG, and Ob regulate insulin secretion in β-cells and isolated islets, promote β-cell proliferation and survival, inhibit β-cell and human islet cell apoptosis, and modulate the expression of genes that are essential in pancreatic islet cell biology. They even induce β-cell regeneration and prevent diabetes in streptozotocin-treated neonatal rats. The receptor(s) mediating their effects are not fully characterized, and a signaling crosstalk has been suggested. The present review summarizes the newest findings on AG, UAG, and Ob expression in pancreatic islets and the role of these peptides on β-cell development, survival, and function.

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Soursop (Annona Muricata) Leaf Water Extract (SLWE) Prevent Pancreatic Β-Cell Damage in Male Wistar Rats Induced By High Fat and High Fructose (HFHF) Diet

International Journal of Diabetes & Metabolic Disorders ◽

10.33140/ijdmd.04.06.09 ◽

2019 ◽

Vol 4 (6) ◽

Keyword(s):

Treatment Group ◽

Wistar Rats ◽

Cell Damage ◽

Water Extract ◽

Pancreatic Β Cell ◽

Β Cells ◽

Β Cell ◽

Pancreatic Β Cells ◽

Glucose Levels ◽

Male Wistar Rats

Background: A high-fructose high fat (HFHF) diet induces dyslipidemia, which can interfere with pancreatic function. Soursop leaf (Annona muricata) water extract (SLWE) has ant hyperlipidemia and antioxidants activity. This research aims to assess the activity of SLWE in preventing pancreatic β-cell damage in male Wistar rats induced by the HFHF diet. Method: This study is a post test group control only research design. Twenty-five wistar rats aged 10-12 weeks, weighing 175- 200 g, were randomly divided into five study groups, namely the normal group (N) laboratory standard diet, the positive group (P) HFHF diet, and the treatment group 1 (T1) HFHF diet+SLWE dose 100mg/kgbw, treatment group 2 (T2) HFHF diet+SLWE dose 200mg/kgbw, and treatment group 3 (T3) HFHF diet+SLWE dose 400mg/kgbw. Diet is given for ten weeks. Measurement of fasting blood glucose levels were taken from the tail using a rapid test conducted at the beginning and end of the study. At the end of the study, the rates were sacrificed under anesthesia. The rats pancreatic organs were surgically removed and blood was taken from the ventricular puncture. Pancreatic organs are used to measure the percentage of pancreatic β cells, which expressed FoxO1 protein, by flow cytometry method, and the average area of pancreatic β cells by immunohistochemistry. Blood is centrifuged to obtain blood plasma, which is used to measure insulin levels. Data were analyzed using One Way Anova and Kruskal Wallis with a significance of p <0.05. Result: SLWE did not cause changes in blood glucose levels, but the administration of SLWE at a doses of 200mg/kgBB tended to increase insulin levels (p> 0.05), decreased percentage number of β-cells expressing FoxO1, and decreased the average area of pancreatic β cells compared to P group (p <0.05). Conclusion: SLWE can prevent pancreatic β-cell damage by increase insulin secretion without causing pancreatic β-cell proliferation.

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Cholecystokinin expression in the β-cell leads to increased β-cell area in aged mice and protects from streptozotocin-induced diabetes and apoptosis

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00159.2015 ◽

2015 ◽

Vol 309 (10) ◽

pp. E819-E828 ◽

Cited By ~ 17

Author(s):

Jeremy A. Lavine ◽

Carly R. Kibbe ◽

Mieke Baan ◽

Sirinart Sirinvaravong ◽

Heidi M. Umhoefer ◽

...

Keyword(s):

Growth Hormone ◽

Cell Apoptosis ◽

Cell Mass ◽

Human Growth ◽

Cell Area ◽

Β Cells ◽

Β Cell ◽

Beneficial Effects ◽

Streptozotocin Induced Diabetes

Cholecystokinin (CCK) is a peptide hormone produced in the gut and brain with beneficial effects on digestion, satiety, and insulin secretion. CCK is also expressed in pancreatic β-cells, but only in models of obesity and insulin resistance. Whole body deletion of CCK in obese mice leads to reduced β-cell mass expansion and increased apoptosis. We hypothesized that islet-derived CCK is important in protection from β-cell apoptosis. To determine the specific role of β-cell-derived CCK in β-cell mass dynamics, we generated a transgenic mouse that expresses CCK in the β-cell in the lean state (MIP-CCK). Although this transgene contains the human growth hormone minigene, we saw no expression of human growth hormone protein in transgenic islets. We examined the ability of MIP-CCK mice to maintain β-cell mass when subjected to apoptotic stress, with advanced age, and after streptozotocin treatment. Aged MIP-CCK mice have increased β-cell area. MIP-CCK mice are resistant to streptozotocin-induced diabetes and exhibit reduced β-cell apoptosis. Directed CCK overexpression in cultured β-cells also protects from cytokine-induced apoptosis. We have identified an important new paracrine/autocrine effect of CCK in protection of β-cells from apoptotic stress. Understanding the role of β-cell CCK adds to the emerging knowledge of classic gut peptides in intraislet signaling. CCK receptor agonists are being investigated as therapeutics for obesity and diabetes. While these agonists clearly have beneficial effects on body weight and insulin sensitivity in peripheral tissues, they may also directly protect β-cells from apoptosis.

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Yeast Morphology Assessment through Automated Image Analysis during Fermentation

Fermentation ◽

10.3390/fermentation7020044 ◽

2021 ◽

Vol 7 (2) ◽

pp. 44

Author(s):

Mario Guadalupe-Daqui ◽

Mandi Chen ◽

Katherine A. Thompson-Witrick ◽

Andrew J. MacIntosh

Keyword(s):

Image Analysis ◽

High Stress ◽

Cross Sectional Area ◽

Automated Image Analysis ◽

Yeast Cells ◽

Morphological Properties ◽

Cell Area ◽

Sectional Area ◽

Cross Sectional ◽

Industrial Fermentation

The kinetics and success of an industrial fermentation are dependent upon the health of the microorganism(s) responsible. Saccharomyces sp. are the most commonly used organisms in food and beverage production; consequently, many metrics of yeast health and stress have been previously correlated with morphological changes to fermentations kinetics. Many researchers and industries use machine vision to count yeast and assess health through dyes and image analysis. This study assessed known physical differences through automated image analysis taken throughout ongoing high stress fermentations at various temperatures (30 °C and 35 °C). Measured parameters included sugar consumption rate, number of yeast cells in suspension, yeast cross-sectional area, and vacuole cross-sectional area. The cell morphological properties were analyzed automatically using ImageJ software and validated using manual assessment. It was found that there were significant changes in cell area and ratio of vacuole to cell area over the fermentation. These changes were temperature dependent. The changes in morphology have implications for rates of cellular reactions and efficiency within industrial fermentation processes. The use of automated image analysis to quantify these parameters is possible using currently available systems and will provide additional tools to enhance our understanding of the fermentation process.

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The Role of High Fat Diets and Liver Peptidase Activity in the Development of Obesity and Insulin Resistance in Wistar Rats

Nutrients ◽

10.3390/nu12030636 ◽

2020 ◽

Vol 12 (3) ◽

pp. 636

Author(s):

Germán Domínguez-Vías ◽

Ana Belén Segarra ◽

Manuel Ramírez-Sánchez ◽

Isabel Prieto

Keyword(s):

Glucose Metabolism ◽

Wistar Rats ◽

Metabolic Disorders ◽

Peptidase Activity ◽

High Fat ◽

Β Cell ◽

High Fat Diets ◽

Glutamyl Transferase ◽

Fat Diets

High-fat diets (HFD) have been widely associated with an increased risk of metabolic disorders and overweight. However, a high intake of sources that are rich in monounsaturated fatty acids has been suggested as a dietary agent that is able to positively influence energy metabolism and vascular function. The main objective of this study was to analyze the role of dietary fats on hepatic peptidases activities and metabolic disorders. Three diets: standard (S), HFD supplemented with virgin olive oil (VOO), and HFD supplemented with butter plus cholesterol (Bch), were administered over six months to male Wistar rats. Plasma and liver samples were collected for clinical biochemistry and aminopeptidase activities (AP) analysis. The expression of inducible nitric oxide synthase (iNOS) was also determined by Western blot in liver samples. The diet supplement with VOO did not induce obesity, in contrast to the Bch group. Though the VOO diet increased the time that was needed to return to the basal levels of plasma glucose, the fasting insulin/glucose ratio and HOMA2-%B index (a homeostasis model index of insulin secretion and valuation of β-cell usefulness (% β-cell secretion)) were improved. An increase of hepatic membrane-bound dipeptidyl-peptidase 4 (DPP4) activity was found only in VOO rats, even if no differences in fasting plasma glucagon-like peptide 1 (GLP-1) were obtained. Both HFDs induced changes in hepatic pyroglutamyl-AP in the soluble fraction, but only the Bch diet increased the soluble tyrosyl-AP. Angiotensinase activities that are implicated in the metabolism of angiotensin II (AngII) to AngIV increased in the VOO diet, which was in agreement with the higher activity of insulin-regulated-AP (IRAP) in this group. Otherwise, the diet that was enriched with butter increased soluble gamma-glutamyl transferase (GGT) and Leucyl-AP, iNOS expression in the liver, and plasma NO. In summary, VOO increased the hepatic activity of AP that were related to glucose metabolism (DPP4, angiotensinases, and IRAP). However, the Bch diet increased activities that are implicated in the control of food intake (Tyrosine-AP), the index of hepatic damage (Leucine-AP and GGT), and the expression of hepatic iNOS and plasma NO. Taken together, these results support that the source of fat in the diet affects several peptidases activities in the liver, which could be related to alterations in feeding behavior and glucose metabolism.

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Regulation of Insulin Secretion and β-Cell Mass by Activating Signal Cointegrator 2

Molecular and Cellular Biology ◽

10.1128/mcb.01412-05 ◽

2006 ◽

Vol 26 (12) ◽

pp. 4553-4563 ◽

Cited By ~ 15

Author(s):

Seon-Yong Yeom ◽

Geun Hyang Kim ◽

Chan Hee Kim ◽

Heun Don Jung ◽

So-Yeon Kim ◽

...

Keyword(s):

Insulin Secretion ◽

Endocrine Cells ◽

Potential Role ◽

Cell Mass ◽

Dominant Negative ◽

Transcriptional Coactivator ◽

Β Cells ◽

Β Cell ◽

Islet Mass

ABSTRACT Activating signal cointegrator 2 (ASC-2) is a transcriptional coactivator of many nuclear receptors (NRs) and other transcription factors and contains two NR-interacting LXXLL motifs (NR boxes). In the pancreas, ASC-2 is expressed only in the endocrine cells of the islets of Langerhans, but not in the exocrine cells. Thus, we examined the potential role of ASC-2 in insulin secretion from pancreatic β-cells. Overexpressed ASC-2 increased glucose-elicited insulin secretion, whereas insulin secretion was decreased in islets from ASC-2+/− mice. DN1 and DN2 are two dominant-negative fragments of ASC-2 that contain NR boxes 1 and 2, respectively, and block the interactions of cognate NRs with the endogenous ASC-2. Primary rat islets ectopically expressing DN1 or DN2 exhibited decreased insulin secretion. Furthermore, relative to the wild type, ASC-2+/− mice showed reduced islet mass and number, which correlated with increased apoptosis and decreased proliferation of ASC-2+/− islets. These results suggest that ASC-2 regulates insulin secretion and β-cell survival and that the regulatory role of ASC-2 in insulin secretion appears to involve, at least in part, its interaction with NRs via its two NR boxes.

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Duodenal-jejunal bypass protects GK rats from β-cell loss and aggravation of hyperglycemia and increases enteroendocrine cells coexpressing GIP and GLP-1

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00422.2010 ◽

2011 ◽

Vol 300 (5) ◽

pp. E923-E932 ◽

Cited By ~ 74

Author(s):

Madeleine Speck ◽

Young Min Cho ◽

Ali Asadi ◽

Francesco Rubino ◽

Timothy J. Kieffer

Keyword(s):

Glucose Tolerance ◽

Glucose Homeostasis ◽

Wistar Rats ◽

Enteroendocrine Cells ◽

Cell Populations ◽

Cell Area ◽

Β Cell ◽

Enteroendocrine Cell ◽

Gk Rats ◽

Jejunal Bypass

Dramatic improvement of type 2 diabetes is commonly observed after bariatric surgery. However, the mechanisms behind the alterations in glucose homeostasis are still elusive. We examined the effect of duodenal-jejunal bypass (DJB), which maintains the gastric volume intact while bypassing the entire duodenum and the proximal jejunum, on glycemic control, β-cell mass, islet morphology, and changes in enteroendocrine cell populations in nonobese diabetic Goto-Kakizaki (GK) rats and nondiabetic control Wistar rats. We performed DJB or sham surgery in GK and Wistar rats. Blood glucose levels and glucose tolerance were monitored, and the plasma insulin, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) levels were measured. β-Cell area, islet fibrosis, intestinal morphology, and the density of enteroendocrine cells expressing GLP-1 and/or GIP were quantified. Improved postprandial glycemia was observed from 3 mo after DJB in diabetic GK rats, persisting until 12 mo after surgery. Compared with the sham-GK rats, the DJB-GK rats had an increased β-cell area and a decreased islet fibrosis, increased insulin secretion with increased GLP-1 secretion in response to a mixed meal, and an increased population of cells coexpressing GIP and GLP-1 in the jejunum anastomosed to the stomach. In contrast, DJB impaired glucose tolerance in nondiabetic Wistar rats. In conclusion, although DJB worsens glucose homeostasis in normal nondiabetic Wistar rats, it can prevent long-term aggravation of glucose homeostasis in diabetic GK rats in association with changes in intestinal enteroendocrine cell populations, increased GLP-1 production, and reduced β-cell deterioration.

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Deficiency of VCP-Interacting Membrane Selenoprotein (VIMP) Leads to G1 Cell Cycle Arrest and Cell Death in MIN6 Insulinoma Cells

Cellular Physiology and Biochemistry ◽

10.1159/000495865 ◽

2018 ◽

Vol 51 (5) ◽

pp. 2185-2197 ◽

Cited By ~ 1

Author(s):

Lili Men ◽

Juan Sun ◽

Decheng Ren

Keyword(s):

Cell Cycle ◽

Cell Death ◽

Insulin Secretion ◽

Cell Apoptosis ◽

Β Cells ◽

Β Cell ◽

Cycle Arrest ◽

G1 Cell Cycle Arrest ◽

Insulinoma Cells

Background/Aims: VCP-interacting membrane selenoprotein (VIMP), an ER resident selenoprotein, is highly expressed in β-cells, however, the role of VIMP in β-cells has not been characterized. In this study, we studied the relationship between VIMP deficiency and β-cell survival in MIN6 insulinoma cells. Methods: To determine the role of VIMP in β-cells, lentiviral VIMP shRNAs were used to knock down (KD) expression of VIMP in MIN6 cells. Cell death was quantified by propidium iodide (PI) staining followed by flow cytometric analyses using a FACS Caliber and FlowJo software. Cell apoptosis and proliferation were determined by TUNEL assay and Ki67 staining, respectively. Cell cycle was analyzed after PI staining. Results: The results show that 1) VIMP suppression induces β-cell apoptosis, which is associated with a decrease in Bcl-xL, and the β-cell apoptosis induced by VIMP suppression can be inhibited by overexpression of Bcl-xL; 2) VIMP knockdown (KD) decreases cell proliferation and G1 cell cycle arrest by accumulating p27 and decreasing E2F1; 3) VIMP KD suppresses unfolded protein response (UPR) activation by regulating the IRE1α and PERK pathways; 4) VIMP KD increases insulin secretion. Conclusion: These results suggest that VIMP may function as a novel regulator to modulate β-cell survival, proliferation, cell cycle, UPR and insulin secretion in MIN6 cells.

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Non-Coding RNA in Pancreas and β-Cell Development

Non-Coding RNA ◽

10.3390/ncrna4040041 ◽

2018 ◽

Vol 4 (4) ◽

pp. 41 ◽

Cited By ~ 7

Author(s):

Wilson K. M. Wong ◽

Anja E. Sørensen ◽

Mugdha V. Joglekar ◽

Anand A. Hardikar ◽

Louise T. Dalgaard

Keyword(s):

Cell Function ◽

Islet Cells ◽

Current Knowledge ◽

Cell Development ◽

Pancreas Development ◽

Β Cell ◽

Neighboring Gene ◽

Non Coding Rnas ◽

And Function

In this review, we provide an overview of the current knowledge on the role of different classes of non-coding RNAs for islet and β-cell development, maturation and function. MicroRNAs (miRNAs), a prominent class of small RNAs, have been investigated for more than two decades and patterns of the roles of different miRNAs in pancreatic fetal development, islet and β-cell maturation and function are now emerging. Specific miRNAs are dynamically regulated throughout the period of pancreas development, during islet and β-cell differentiation as well as in the perinatal period, where a burst of β-cell replication takes place. The role of long non-coding RNAs (lncRNA) in islet and β-cells is less investigated than for miRNAs, but knowledge is increasing rapidly. The advent of ultra-deep RNA sequencing has enabled the identification of highly islet- or β-cell-selective lncRNA transcripts expressed at low levels. Their roles in islet cells are currently only characterized for a few of these lncRNAs, and these are often associated with β-cell super-enhancers and regulate neighboring gene activity. Moreover, ncRNAs present in imprinted regions are involved in pancreas development and β-cell function. Altogether, these observations support significant and important actions of ncRNAs in β-cell development and function.

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