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Does Non-Insulin-Dependent Diabetes Mellitus Impact on Monosaccharide Transporter Expression in Human Intestine?
(20.02±5.16) much higher than perilla oil alone did . Other lipids also potentiated GLP-2 secretion significantly when administered with a sweetener. Conclusions : Effect on GLP-2 secretion differs among a variety of lipids. A sweetener may did not have capability to induce GLP-2 secretion alone but has synergistic effect by the combination of dietary lipids and a sweetener on GLP-2 secretion. The potential effects by sugar, sweetener, and lipids may be physiologically important and these information will give us a new strategy for nutritional therapy for intestinal disorders.
Sa1768
BACKGROUND: We have recently found that primary cilia in the stomach are present on ghrelin- and gastrin-expressing cells, suggesting that they might be involved in the regulation of food intake. To test this hypothesis, we analyzed the expression of primary cilia in response to food and gastric distension. METHODS: C57BL/6 mice were either fasted for 16 h or allowed access to food (fed). For the re-feeding experiment, stomachs were taken from fasted mice (0 min), then after free access to food for 30, 60 and 90 min. For ex-vivo distension experiments, stomachs from fasted mice were flushed with PBS, the pylorus ligated, then filled to half (≈0.4 ml) or full gastric capacity (≈0.8 ml) with Krebs (CON), or calciumfree Krebs (EGTA) buffer. The stomachs were then kept in CON buffer or EGTA buffer for calcium-free studies at 37°C for 30 min. Stomach sections were stained with anti-acetylatedα-tubulin and the number of primary cilia per gland (cpg) was determined. Fed and fasted samples were stained for gastrin or ghrelin and quantified as positive cells per field (cpf). RESULTS: The number of cilia observed in the antra of fasted mice was significantly higher than in the fed mice (1.21 vs. 0.93 cpg, N=14, P<0.05.) There were no differences in the corpus. Since gastrin- and ghrelin-expressing cells show cilia, we compared their numbers in the fed and fasted stomachs. In the fasted group, we found a slight increase in the number of gastrin (16.35 vs. 20.29 cpf) and ghrelin (24.99 vs. 25.55 cpf) cells compared to fed, although the numbers did not reach significance. In the refed mice, there was a decrease in the number of cpg in the refed antra over 90 min (N=8, P<0.001.) Interestingly, the corpus showed a peak in cpg numbers only at 30 min (P<0.05.) We then tested whether stomach distension ex-vivo affected cilia numbers. No changes in the antral cilia with half compared to fully distended stomachs in CON (1.10 vs. 1.14 cpg, N=6) were observed. The number of antral cilia decreased with EGTA buffer in full stomachs (1.14 vs. 0.83 cpg, N=6, P<0.05.) In contrast, the number of cilia increased in the corpus of full stomachs (0.65 vs. 0.98 cpg, N=5, P<0.001), and this effect was ablated in the presence of EGTA buffer (0.98 vs. 0.58 cpg, N=5, P<0.001.) EGTA buffer did not affect the basal number of cilia in the corpus of stomachs filled to half capacity. CONCLUSION: Primary cilia in the gastric epithelium respond differentially to feeding. Food ingestion regulated the presence of antral cilia, while distension regulated it in the corpus. Since EGTA buffer blocked the number of cilia in both conditions, we concluded that both effects are calcium-dependent. Therefore primary cilia respond to different luminal signals. In the corpus they respond to mechanical stimuli, e.g. distension; while in the antrum, cilia respond to nutrients present in food.
Sa1766 Enteroendocrine Cells and Appetite Dysregulation in Crohn's Disease Gordon W. Moran, John McLaughlin Background: Loss of appetite and malnutrition in active Crohn's disease (CD) are important problems. However, the biological mechanisms underpinning appetite loss are unclear. Enteroendocrine cells (EEC) form a pivotal part of the brain-gut axis that controls appetite and satiety. Normally, they secrete gut hormones such as glucagon like peptide-1 (GLP-1) and polypeptide YY (PYY) which act on appetite control centres in the brainstem through an endocrine or paracrine pathway. Recent animal research has suggested that immuneregulated upregulation of proximal CCK-secreting EEC plays a mechanistic role in the appetite and feeding disturbance observed during gut inflammation. We have studied whether distal ileal EEC are perturbed in ileocolonic CD. Methods: Patients with active intestinal inflammation were studied: active small and large bowel (SB and LB respectively) CD and age/sex matched controls. Patient symptoms were assessed using a validated visual analogue score (VAS). At tissue level EEC markers and transcription factors have been studied through immunohistochemistry and quantitative polymerase chain reaction. Gut hormone responses to a test meal (PYY and GLP-1) were studied using a multiplex-ELISA technique Results: CD patients with active inflammation displayed a ~6-fold significant reduction in appetite parameters as measured by VAS (p<0.0001). At the tissue level, the general EEC marker chromogranin A showed a 1.8-fold increase in positive cells (p=0.01), while GLP-1 cells were increased 2.5-fold in SB CD (p=0.04). Phox2b, a neural transcription factor associated with CD in a recent genome wide association study, was co-localised to EEC through dual immunofluorescence and showed a 1.5-fold increase in SB CD compared to controls. At mRNA level, significant increases were noted for Chromogranin A (3.3-fold; p=0.009), GLP1 (2.7-fold p=0.05), and Ubiquitination protein 4a (Ube4a) (2.2-fold p=0.02). Neurogenin 3, a NOTCH transcription factor central to EEC differentiation also showed ~2 fold-upregulation (p=0.04). In plasma, total PYY showed a 2-fold increase in postprandial levels in the SB-CD group compared to controls (p=0.038). It was not elevated in LB-CD. Active GLP1 levels were however not elevated. Conclusion: Measurable changes were observed in distal small intestinal EEC markers in active CD, including elements of both GLP-1 and PYY. These data support a potential role of EEC in appetite dysregulation in intestinal inflammation. Measurements of gut hormones in peripheral blood may not adequately reflect biologically important changes occurring at the epithelial level. Enhanced EEC responses to nutrients may adversely affect appetite through increased gut-brain signalling, and provide novel therapeutic targets. Further work is underway to further dissect the neuroendocrine circuitry in this system.
Sa1769 Does Non-Insulin-Dependent Diabetes Mellitus Impact on Monosaccharide Transporter Expression in Human Intestine? Raphael N. Vuille-dit-Bille, Simone M. Camargo, Luca Emmenegger, Eva E. Kummer, Tom Sasse, Zsofia Forras-Kaufman, Sena Kuyumcu, Mark R. Fox, Werner Schwizer, Oliver Goetze, François Verrey Background: Dietary carbohydrates are absorbed in the small intestine as monosaccharides via three distinct transporters: SGLT1 (sodium/glucose cotransporter; SLC5A1) a secondary active transporter located in the luminal membrane of enterocytes, GLUT5 (glucose/fructose transporter; SLC2A5) and GLUT2 (glucose transporter; SLC2A2), that function as facilitated diffusion pathways in the apical and the basolateral enterocyte-membrane, respectively. Noninsulin-dependent diabetes mellitus (NIDDM; Diabetes mellitus, type II) is a common disease of Glucose metabolism, which can lead to life-threatening complications. Impaired fasting Glucose (IFG) refers to a pre-diabetic condition, usually preceding NIDDM. The longitudinal distribution of monosaccharide transporter expression in the human intestine has never been described. Furthermore, it is unclear whether NIDDM and/or IFG impact on intestinal monosaccharide transporter distribution and/or expression, possibly affecting glucose absorption. Aims: The aims of the present study are (1.) to characterize the distribution of monosaccharide transporters in non-diabetic human intestine and (2.) to test the potential impact that NIDDM and/or IFG have on monosacchride transporter distribution and/or expression. Methods: Three groups of patients referred for duodenoscopy and/or coloscopy were investigated. Group 1 (NIDDM; n=11: Patients with history of NIDDM; Group 2 (Control; n=5): Patients without history of NIDDM or IFG and with fasting Glucose levels below 5.6 [mmol/l] (=100 [mg/dl]); Group 3 (IFG; n=6): Patients without history of NIDDM, with fasting Glucose concentrations from 5.6 [mmol/l] (=100 [mg/dl]) to 6.9 [mmol/l] (= 125 [mg/dl]). In all groups, mRNA levels of SGLT1, GLUT2 and GLUT5 are tested by quantitative real time PCR (qPCR) at four different intestinal localizations: Duodenum, parts II and III, Terminal Ileum and Ascending Colon. Fasting Glucose levels and Glycosylated Hemoglobin (HbA1c) are assessed in all patients by routine laboratory analysis. Results: Preliminary results consistently demonstrate proximal to distal an axial decrease of SGLT1, GLUT2 and GLUT5 mRNA expression along the human intestine in non-diabetic patients. Comparing gene expression levels of SGLT1, GLUT2 and GLUT5 in NIDDM-patients vs. IFG-patients vs. Control-patiens, shows no difference between the investigated groups. Conclusion: Our results show a decreasing monosaccharide transporter expression gradient from proximal to distal along the human gastrointestinal tract, suggesting that most of the carbohydrate absorption occurs in the proximal small intestine. Neither transporter distribution, nor their expression levels are affected by NIDDM or IFG, indicating that intestinal Glucose absorption is similar in patients suffering from NIDDM or IFG and in non-diabetic patients.
Sa1767 Plasma Ghrelin Paradoxically Rises Upon Feeding in Active Crohn's Disease Gordon W. Moran, John McLaughlin Aims: Ghrelin is an orexigenic hormone. Ghrelin may also be a signal to prime the gut for nutrient absorption. An anti-inflammatory role has also been proposed. A single previous report has suggested an increase in plasma fasting acylated ghrelin expression in active inflammatory bowel disease (IBD), with levels returning to normal once the disease is in remission. The postprandial response of ghrelin in intestinal inflammation has never been described. Methods: Twenty-one patients with active Crohn's disease (CD) and 12 healthy controls were recruited. Disease activity was classified through independent histopathological/ endoscopic assessments, validated patient questionnaires and biochemical scores. Gut hormone responses to a mixed nutrient test meal (Heinz Cream of Chicken Soup, 300g) were studied using a multiplex ELISA technique (Luminex). Patient symptoms were assessed using a validated visual analogue score (VAS). A subgroup of patients who achieved remission (without surgery or anti-TNFα treatment) was also re-studied later. Results: CD patients with active inflammation displayed a ~6-fold significant reduction in basal appetite parameters as measured by VAS (p<0.0001). The pattern of the postprandial ghrelin response was paradoxically altered in the CD group with a rise noted postprandially. In the control group ghrelin levels displayed the expected drop after the test meal. Consequently, acylated ghrelin levels were higher in the CD group with a 3-fold increase noted in the total ghrelin level after the test meal. A significant correlation (p=0.019) was noted between the total acetylated ghrelin secreted and the Crohn's Disease Activity Index. A significant correlation also existed between ghrelin secretion and stool frequency (p=0.01), more so in the SB CD group (p= 0.004). There was a significant negative correlation noted between the abdominal pain scores in the visual analogue score specifically in the SB CD group (p=0.0008). After treatment of CD, the VAS reverted to those of normal controls and ghrelin responses to the test meal now showed a postprandial fall, as expected physiologically. Discussion: Ghrelin levels show an unexpected rise in response to a test meal in ileal CD. Ghrelin is not expressed in the healthy distal small bowel. It is now necessary to explore whether inflammation induces its expression there, or whether gastric secretion ghrelin is somehow amplified at a distance. In intestinal inflammation, it may be that ghrelin assumes more its secondary role, that of an anti-inflammatory peptide. This plays a protective role when the antigen load of a meal is presented to the inflamed gut. The changes noted after treatment tend to corroborate this. Its postprandial response may also present a useful novel biomarker of disease activity.
S-323
AGA Abstracts
AGA Abstracts
Differential Response of Primary Cilia to Food and Distension in the Gastric Corpus and Antrum Milena Saqui-Salces, Juanita L. Merchant
Sa1768
BACKGROUND: We have recently found that primary cilia in the stomach are present on ghrelin- and gastrin-expressing cells, suggesting that they might be involved in the regulation of food intake. To test this hypothesis, we analyzed the expression of primary cilia in response to food and gastric distension. METHODS: C57BL/6 mice were either fasted for 16 h or allowed access to food (fed). For the re-feeding experiment, stomachs were taken from fasted mice (0 min), then after free access to food for 30, 60 and 90 min. For ex-vivo distension experiments, stomachs from fasted mice were flushed with PBS, the pylorus ligated, then filled to half (≈0.4 ml) or full gastric capacity (≈0.8 ml) with Krebs (CON), or calciumfree Krebs (EGTA) buffer. The stomachs were then kept in CON buffer or EGTA buffer for calcium-free studies at 37°C for 30 min. Stomach sections were stained with anti-acetylatedα-tubulin and the number of primary cilia per gland (cpg) was determined. Fed and fasted samples were stained for gastrin or ghrelin and quantified as positive cells per field (cpf). RESULTS: The number of cilia observed in the antra of fasted mice was significantly higher than in the fed mice (1.21 vs. 0.93 cpg, N=14, P<0.05.) There were no differences in the corpus. Since gastrin- and ghrelin-expressing cells show cilia, we compared their numbers in the fed and fasted stomachs. In the fasted group, we found a slight increase in the number of gastrin (16.35 vs. 20.29 cpf) and ghrelin (24.99 vs. 25.55 cpf) cells compared to fed, although the numbers did not reach significance. In the refed mice, there was a decrease in the number of cpg in the refed antra over 90 min (N=8, P<0.001.) Interestingly, the corpus showed a peak in cpg numbers only at 30 min (P<0.05.) We then tested whether stomach distension ex-vivo affected cilia numbers. No changes in the antral cilia with half compared to fully distended stomachs in CON (1.10 vs. 1.14 cpg, N=6) were observed. The number of antral cilia decreased with EGTA buffer in full stomachs (1.14 vs. 0.83 cpg, N=6, P<0.05.) In contrast, the number of cilia increased in the corpus of full stomachs (0.65 vs. 0.98 cpg, N=5, P<0.001), and this effect was ablated in the presence of EGTA buffer (0.98 vs. 0.58 cpg, N=5, P<0.001.) EGTA buffer did not affect the basal number of cilia in the corpus of stomachs filled to half capacity. CONCLUSION: Primary cilia in the gastric epithelium respond differentially to feeding. Food ingestion regulated the presence of antral cilia, while distension regulated it in the corpus. Since EGTA buffer blocked the number of cilia in both conditions, we concluded that both effects are calcium-dependent. Therefore primary cilia respond to different luminal signals. In the corpus they respond to mechanical stimuli, e.g. distension; while in the antrum, cilia respond to nutrients present in food.
Sa1766 Enteroendocrine Cells and Appetite Dysregulation in Crohn's Disease Gordon W. Moran, John McLaughlin Background: Loss of appetite and malnutrition in active Crohn's disease (CD) are important problems. However, the biological mechanisms underpinning appetite loss are unclear. Enteroendocrine cells (EEC) form a pivotal part of the brain-gut axis that controls appetite and satiety. Normally, they secrete gut hormones such as glucagon like peptide-1 (GLP-1) and polypeptide YY (PYY) which act on appetite control centres in the brainstem through an endocrine or paracrine pathway. Recent animal research has suggested that immuneregulated upregulation of proximal CCK-secreting EEC plays a mechanistic role in the appetite and feeding disturbance observed during gut inflammation. We have studied whether distal ileal EEC are perturbed in ileocolonic CD. Methods: Patients with active intestinal inflammation were studied: active small and large bowel (SB and LB respectively) CD and age/sex matched controls. Patient symptoms were assessed using a validated visual analogue score (VAS). At tissue level EEC markers and transcription factors have been studied through immunohistochemistry and quantitative polymerase chain reaction. Gut hormone responses to a test meal (PYY and GLP-1) were studied using a multiplex-ELISA technique Results: CD patients with active inflammation displayed a ~6-fold significant reduction in appetite parameters as measured by VAS (p<0.0001). At the tissue level, the general EEC marker chromogranin A showed a 1.8-fold increase in positive cells (p=0.01), while GLP-1 cells were increased 2.5-fold in SB CD (p=0.04). Phox2b, a neural transcription factor associated with CD in a recent genome wide association study, was co-localised to EEC through dual immunofluorescence and showed a 1.5-fold increase in SB CD compared to controls. At mRNA level, significant increases were noted for Chromogranin A (3.3-fold; p=0.009), GLP1 (2.7-fold p=0.05), and Ubiquitination protein 4a (Ube4a) (2.2-fold p=0.02). Neurogenin 3, a NOTCH transcription factor central to EEC differentiation also showed ~2 fold-upregulation (p=0.04). In plasma, total PYY showed a 2-fold increase in postprandial levels in the SB-CD group compared to controls (p=0.038). It was not elevated in LB-CD. Active GLP1 levels were however not elevated. Conclusion: Measurable changes were observed in distal small intestinal EEC markers in active CD, including elements of both GLP-1 and PYY. These data support a potential role of EEC in appetite dysregulation in intestinal inflammation. Measurements of gut hormones in peripheral blood may not adequately reflect biologically important changes occurring at the epithelial level. Enhanced EEC responses to nutrients may adversely affect appetite through increased gut-brain signalling, and provide novel therapeutic targets. Further work is underway to further dissect the neuroendocrine circuitry in this system.
Sa1769 Does Non-Insulin-Dependent Diabetes Mellitus Impact on Monosaccharide Transporter Expression in Human Intestine? Raphael N. Vuille-dit-Bille, Simone M. Camargo, Luca Emmenegger, Eva E. Kummer, Tom Sasse, Zsofia Forras-Kaufman, Sena Kuyumcu, Mark R. Fox, Werner Schwizer, Oliver Goetze, François Verrey Background: Dietary carbohydrates are absorbed in the small intestine as monosaccharides via three distinct transporters: SGLT1 (sodium/glucose cotransporter; SLC5A1) a secondary active transporter located in the luminal membrane of enterocytes, GLUT5 (glucose/fructose transporter; SLC2A5) and GLUT2 (glucose transporter; SLC2A2), that function as facilitated diffusion pathways in the apical and the basolateral enterocyte-membrane, respectively. Noninsulin-dependent diabetes mellitus (NIDDM; Diabetes mellitus, type II) is a common disease of Glucose metabolism, which can lead to life-threatening complications. Impaired fasting Glucose (IFG) refers to a pre-diabetic condition, usually preceding NIDDM. The longitudinal distribution of monosaccharide transporter expression in the human intestine has never been described. Furthermore, it is unclear whether NIDDM and/or IFG impact on intestinal monosaccharide transporter distribution and/or expression, possibly affecting glucose absorption. Aims: The aims of the present study are (1.) to characterize the distribution of monosaccharide transporters in non-diabetic human intestine and (2.) to test the potential impact that NIDDM and/or IFG have on monosacchride transporter distribution and/or expression. Methods: Three groups of patients referred for duodenoscopy and/or coloscopy were investigated. Group 1 (NIDDM; n=11: Patients with history of NIDDM; Group 2 (Control; n=5): Patients without history of NIDDM or IFG and with fasting Glucose levels below 5.6 [mmol/l] (=100 [mg/dl]); Group 3 (IFG; n=6): Patients without history of NIDDM, with fasting Glucose concentrations from 5.6 [mmol/l] (=100 [mg/dl]) to 6.9 [mmol/l] (= 125 [mg/dl]). In all groups, mRNA levels of SGLT1, GLUT2 and GLUT5 are tested by quantitative real time PCR (qPCR) at four different intestinal localizations: Duodenum, parts II and III, Terminal Ileum and Ascending Colon. Fasting Glucose levels and Glycosylated Hemoglobin (HbA1c) are assessed in all patients by routine laboratory analysis. Results: Preliminary results consistently demonstrate proximal to distal an axial decrease of SGLT1, GLUT2 and GLUT5 mRNA expression along the human intestine in non-diabetic patients. Comparing gene expression levels of SGLT1, GLUT2 and GLUT5 in NIDDM-patients vs. IFG-patients vs. Control-patiens, shows no difference between the investigated groups. Conclusion: Our results show a decreasing monosaccharide transporter expression gradient from proximal to distal along the human gastrointestinal tract, suggesting that most of the carbohydrate absorption occurs in the proximal small intestine. Neither transporter distribution, nor their expression levels are affected by NIDDM or IFG, indicating that intestinal Glucose absorption is similar in patients suffering from NIDDM or IFG and in non-diabetic patients.
Sa1767 Plasma Ghrelin Paradoxically Rises Upon Feeding in Active Crohn's Disease Gordon W. Moran, John McLaughlin Aims: Ghrelin is an orexigenic hormone. Ghrelin may also be a signal to prime the gut for nutrient absorption. An anti-inflammatory role has also been proposed. A single previous report has suggested an increase in plasma fasting acylated ghrelin expression in active inflammatory bowel disease (IBD), with levels returning to normal once the disease is in remission. The postprandial response of ghrelin in intestinal inflammation has never been described. Methods: Twenty-one patients with active Crohn's disease (CD) and 12 healthy controls were recruited. Disease activity was classified through independent histopathological/ endoscopic assessments, validated patient questionnaires and biochemical scores. Gut hormone responses to a mixed nutrient test meal (Heinz Cream of Chicken Soup, 300g) were studied using a multiplex ELISA technique (Luminex). Patient symptoms were assessed using a validated visual analogue score (VAS). A subgroup of patients who achieved remission (without surgery or anti-TNFα treatment) was also re-studied later. Results: CD patients with active inflammation displayed a ~6-fold significant reduction in basal appetite parameters as measured by VAS (p<0.0001). The pattern of the postprandial ghrelin response was paradoxically altered in the CD group with a rise noted postprandially. In the control group ghrelin levels displayed the expected drop after the test meal. Consequently, acylated ghrelin levels were higher in the CD group with a 3-fold increase noted in the total ghrelin level after the test meal. A significant correlation (p=0.019) was noted between the total acetylated ghrelin secreted and the Crohn's Disease Activity Index. A significant correlation also existed between ghrelin secretion and stool frequency (p=0.01), more so in the SB CD group (p= 0.004). There was a significant negative correlation noted between the abdominal pain scores in the visual analogue score specifically in the SB CD group (p=0.0008). After treatment of CD, the VAS reverted to those of normal controls and ghrelin responses to the test meal now showed a postprandial fall, as expected physiologically. Discussion: Ghrelin levels show an unexpected rise in response to a test meal in ileal CD. Ghrelin is not expressed in the healthy distal small bowel. It is now necessary to explore whether inflammation induces its expression there, or whether gastric secretion ghrelin is somehow amplified at a distance. In intestinal inflammation, it may be that ghrelin assumes more its secondary role, that of an anti-inflammatory peptide. This plays a protective role when the antigen load of a meal is presented to the inflamed gut. The changes noted after treatment tend to corroborate this. Its postprandial response may also present a useful novel biomarker of disease activity.
S-323
AGA Abstracts
AGA Abstracts
Differential Response of Primary Cilia to Food and Distension in the Gastric Corpus and Antrum Milena Saqui-Salces, Juanita L. Merchant