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Sa1851 Bile Acid-Induced Acute Pancreatitis Is Mediated by Acinar Cell Leukotriene B4 Secretion
AGA Abstracts
baseline (24.01±2.9 umol/L) at 6 (21.72±2.4 umol/L; p=ns) and 12 months after VSG surgery (15.63±2.9 umol/L; RM ANOVA; p,0.05). Serum C4 levels were also reduced from baseline (25.4±2.9ng/ml) in the VSG subjects at 6 (13.4±2.3ng/ml;p=ns) and 12 months after surgery (11.31±2.7ng/ml; RM ANOVA; p,0.05).Conclusion: Mice and humans have suppression of hepatic bile acid production after VSG as evidenced by reduced C4 serum levels. This reduction was independent of weight loss as VSG mice had similar 8 week weight as the SH pair fed mice having higher C4 levels. We speculate that this reduced production maybe due to feedback inhibition from increase in bile acid flux early post-surgery as seen in our animal experiment. This exciting finding needs to be verified in a larger cohort of patients to understand the implications of bile acid signaling on metabolic improvements postVSG surgery.
the prevention of pancreatitis with TRPV1 blockade. Therefore, we sought to determine the source of LTB4 using immunohistochemistry for 5-lipoxygenase (5-LO), the rate-limiting enzyme in LTB4 biosynthesis. Very little 5-LO was observed in normal mouse pancreatic acinar cells. However, retrograde pancreatic ductal infusion of bile acids caused a marked increase in the amount of 5-LO immunostaining in acinar cells and in the number of acinar cells exhibiting 5-LO immunoreactivity. Pancreatic ducts and islets exhibited little if any 5LO immunoreactivity. In bile acid-treated animals, 5-LO immunoreactivity was limited to the basal poles of the acinar cells, consistent with the distribution of rough endoplasmic reticulum (rER). A similar pattern of 5-LO immunoreactivity was seen in human pancreas samples from acute pancreatitis patients. Additional evidence in favor of the concept that acinar cells are the source of bile acid-induced LTB4 was obtained using mouse pancreatic acini in vitro. The bile acid, taurolithocholate acid 3-sulfate (TLCS; 500 μM), stimulated time-dependent LTB4 release from pancreatic acini in vitro. Conclusions: We conclude that bile acids damage the pancreas in part by stimulating increased 5-LO activity in pancreatic acinar cells resulting in release of LTB4 which subsequently activates TRPV1 in primary sensory neurons to cause neurogenic inflammation and acute pancreatitis.
Sa1850 First Results of the Barosense ACE Stapler Procedure for the Treatment of Morbid Obesity: Effect on Food Intake and Satiety Mark van Avesaat, Givan F. Paulus, José M. Conchillo, Nicole D. Bouvy, Ad Masclee
Sa1852
Conventional bariatric surgery is a very effective therapy for weight loss but has several risks and limitations. Recently alternative non-incisional endoscopic procedures have been introduced such as the BaroSense Articulating Circular Endoscopic (ACE) Stapler technique. This trans-oral procedure intends to reduce the capacity of the stomach to expand by endoscopically creating plications in the region of the fundus and greater curvature. In this first explorative study we tried to provide more information about the potential efficacy and mechanism of weight loss of the BaroSense ACE stapler procedure. Methods: This prospective study was performed in 10 morbidly obese patients (4 women, mean age 41±10 years, mean BMI 39.6±2.8 kg/m2) who underwent the BaroSense ACE stapler. Patients were studied prior to and one month after the operation. All procedures went without any complications and patients were discharged one day after the operation. Gastric emptying (by 13C octanoic acid breath test) and satiety (VAS) were measured at different time points before and after the intake of a standardized, fixed breakfast meal (t=0, breakfast consisted of 200kcal and 100mg 13C octanoic acid was added). Food intake was assessed by offering an ad libitum meal at t=240 min. Comparisons of gastric emptying half time and food intake were analyzed using paired samples t-tests whereas all VAS scores were examined by using the repeated measures ANOVA. All results are expressed as mean±S.E.M. Results: The included patients showed loss of 19.9±5.7% excess BMI one month postoperatively. Patients did not report any gastrointestinal complaints, but satiety AUC was significantly increased 1 month after the procedure compared to before (AUC 68.8±8.9 and 48.1±9.4 p ,0.02). Ad libitum food intake decreased significantly from 842.8±45.9 to 441.8±100.1 kcal (preop vs postop, p,0.01). No differences were observed in gastric emptying half time (141.3±5.9 versus 138.7±12.3 minutes, p.0.05) Conclusion: Our data indicate that endoscopic reduction of the stomach volume by the BaroSense ACE stapler procedure results in significant weight loss, increase in satiety and a decrease in food intake one month postoperatively. Although capacity of the stomach for relaxation is impaired, gastric emptying of a standard and fixed test meal was not affected. These first explorative data indicate that the BaroSense ACE stapler is a potentially very promising technique that effectively reduces food intake and affects satiety but does not interfere with gastric emptying. Inclusion of larger numbers of patients and more prolonged follow up of BaroSense ACE stapler procedures is needed.
Reduction of Lipotoxicity by Two Distinct Lipase Inhibitors Improves Local, Systemic, Inflammatory Outcomes and Mortality in a Model of Biliary Severe Acute Pancreatitis (SAP) Without Interfering With the Primary Insult Chandra Durgampudi, Pawan Noel, Krutika Patel, Rachel Cline, Vivek Mishra, James P. DeLany, Ram N. Trivedi, Chathur Acharya, Deepthi Jaligama, Sarah Navina, Vijay Singh BACKGROUND AND AIMS: Our recent studies suggest that lipolysis of intrapancreatic fat, which is increased in obesity may be associated with the worse outcomes of acute pancreatitis (AP). High unsaturated fatty acid (UFA) concentrations are noted in the debridement fluid of SAP patients. To further study this in a model relevant to human biliary AP, we studied the efficacy of 2 lipase inhibitors; Orlistat and Cetelistat on parameters of severity and etiology of AP. METHODS: AP was induced by infusing glyceryl trilinoleate (GTL, 0.1ml )into the pancreatic duct of male Wistar rats (300-400gm) with or without dissolved orlistat or cetelistat. The duct was ligated at the end of the infusion. Animals were followed till 5 days or mortality, whichever came first. A p value of ,0.05 was regarded as significant when comparing two groups. RESULTS: GTL infusion resulted in severe hemorrhagic AP (70-80% necrosis) with 100% mortality in 24 hours and a high serum bilirubin (5.9± 1.0 vs. 0.9±0.2 mg/dl vs. controls) supportive of severe biliary AP. The significant changes compared to controls included hyperlipasemia (6430±3198 U/L vs. 94±17 U/L), hypercytokinemia (IL-1 beta 367±152 vs. 20±4 pg/ml and KC/GRO 13266±2452 vs. 650±40 pg/ml) , elevated non-esterified fatty acids (NEFA; 2578±1227 μM vs. 220±35 μM ), UFA (1561±726μM vs. 94±17μM), linoleic acid (LA; 827±368 μM vs. 54±5 μM) renal failure (blood urea nitrogen [BUN] 88±22 vs. 19±1mg/dl) and Lung injury (8±2.1 TUNEL positive cells/HPF vs. 0.3±0.1). Both lipase orlistat and cetelistat significantly reduced these (IL1beta; 45±24 pg/ml and 66±30 pg/ml, KC/GRO; 1044±137 and 1400±545 pg/ml, serum lipase; 169±24 U/L and 526±515 U/L, NEFA; 548±71μM and 455±57μM, UFA; 312±46μM and 241±57μM, LA; 174±25μM and 112±28μM, BUN; 18.7±1.4 and 18.1±6.0, Lung injury; 0.4±0.1 and 1.6±0.5 TUNEL positive cells/HPF respectively and significantly reduced 5 day mortality (0/10 in the orlistat group and 1/10 in the cetelistat group) with no evidence of hemorrhagic AP except in the one animal which died in the cetelistat group. There was no reduction in the serum bilirubin (6.0±1.2 mg/dl and 5.3±1.8mg/dl) or amylase at day 1 by either orlistat or cetelistat suggestive of ongoing biliary AP. Oil red O staining revealed several areas of red staining in the rats receiving intraductal GTL. CONCLUSIONS: Consistent with their role as lipase inhibitors, both orlistat and cetelistat reduced serum lipase, NEFA, UFA and LA. However the improvement in local injury, inflammatory response, organ failure and survival by the lipase inhibitors without affecting parameters of biliary pancreatitis (serum bilirubin, amylase) and irrespective of the accumulation of intrapancreatic lipid pools suggests that pancreatic lipase inhibition improves the outcomes of SAP in obesity without affecting the primary insult. Sa1853 Ethanol Feeding Down-Regulates Whereas Experimental Alcoholic Pancreatitis Stimulates Autophagy Jinliang Ni, Samuel W. French, Anna S. Gukovskaya, Ilya Gukovsky, Olga A. Mareninova Background & Aims: Alcohol abuse is a major risk factor for pancreatitis, but the mechanism of alcoholic pancreatitis remains elusive. It is not clear how does ethanol predispose to pancreatitis; and at the same time, why ethanol feeding alone does not cause pronounced pancreatic injury (at least, in rodents) and, therefore, must be combined with another stressor to cause disease. Autophagy is activated in non-alcoholic pancreatitis, but defective lysosomal function makes autophagic flux inefficient, underlying key pancreatitis pathologies. Here we investigate the effects of ethanol feeding and experimental alcoholic pancreatitis on autophagy in pancreas. Methods: Mice received ethanol-containing or control Lieber-DeCarli diet for 6 weeks followed or not by 7 i.p. injections of low-dose (3 μg/kg) cerulein (CR). We measured the effects of ethanol alone and the alcoholic pancreatitis on Atg proteins critical for autophagosome formation: ULK1/Atg1, initiating this process; Atg5 and Beclin1/ Atg6, mediating autophagosome maturation; LC3/Atg8, a protein key for autophagosome closure in the process of which its' cytosolic LC3-I form is lipidated to LC3-II, which selectively localizes to autophagosomes; and Atg4, a protease that mediates delipidation of LC3-II necessary for its recycling. Results: Ethanol feeding markedly activated AMPK, leading to ULK1 phosphorylation that indicates autophagy initiation. By contrast, ethanol greatly down-regulated pancreatic LC3-II, as shown by immunoblotting and immunofluorescence. Accordingly, EM showed fewer autophagic vacuoles in pancreas of ethanol-fed mice. In search of underlying mechanism, we found that ethanol markedly increased both the level and activity of Atg4, indicating that ethanol fails to stimulate autophagosome formation because of excessive LC3-II delipidation. Differently, in ethanol+ low-dose CR pancreatitis, Atg4 dramatically decreased while LC3-II level and autophagic vacuoles increased. Thus, ethanol alone inhibits whereas alcoholic pancreatitis stimulates autophagy. At the same time, ethanol alone and alcoholic pancreatitis both decreased the levels of the lysosomal membrane
Satiety scores 1 month postoperative were significantly increased compared to preoperative scores (# p,0.05, * p,0.01, ** p,0.001) Sa1851 Bile Acid-Induced Acute Pancreatitis Is Mediated by Acinar Cell Leukotriene B4 Secretion Rafiq A. Shahid, Steven R. Vigna, Rodger A. Liddle Background: Retrograde perfusion of the pancreatic duct with bile acids causes acute pancreatitis of the head of the pancreas and is a model of biliary pancreatitis in mice. We have previously shown that bile acid-induced pancreatitis can be reduced by pharmacological blockade of the Transient Receptor Potential Vanilloid 1 receptor (TRPV1) on primary sensory nerves to prevent neurogenic inflammation. However, the endogenous ligand responsible for activation of TRPV1 in pancreatitis is unknown. We proposed that leukotriene B 4 (LTB4),which has been shown to activate TRPV1 in vitro, may be a critical mediator of TRPV1 activation and pancreatitis. Methods and Results: In support of this hypothesis we demonstrated that (1) LTB4 levels in the pancreas are markedly elevated in acute pancreatitis, (2) LTB4 infused into the celiac artery causes acute pancreatitis, (3) inhibition of LTB4 biosynthesis prevents inflammation, and (4) LTB4-induced pancreatitis is prevented by TRPV1 blockade. Because acute pancreatitis is accompanied by neutrophil infiltration and neutrophils are a rich source of LTB4, it was assumed that neutrophils account for the increased LTB4 levels in bile acid-induced pancreatitis. However, this would not explain
AGA Abstracts
S-320
baseline (24.01±2.9 umol/L) at 6 (21.72±2.4 umol/L; p=ns) and 12 months after VSG surgery (15.63±2.9 umol/L; RM ANOVA; p,0.05). Serum C4 levels were also reduced from baseline (25.4±2.9ng/ml) in the VSG subjects at 6 (13.4±2.3ng/ml;p=ns) and 12 months after surgery (11.31±2.7ng/ml; RM ANOVA; p,0.05).Conclusion: Mice and humans have suppression of hepatic bile acid production after VSG as evidenced by reduced C4 serum levels. This reduction was independent of weight loss as VSG mice had similar 8 week weight as the SH pair fed mice having higher C4 levels. We speculate that this reduced production maybe due to feedback inhibition from increase in bile acid flux early post-surgery as seen in our animal experiment. This exciting finding needs to be verified in a larger cohort of patients to understand the implications of bile acid signaling on metabolic improvements postVSG surgery.
the prevention of pancreatitis with TRPV1 blockade. Therefore, we sought to determine the source of LTB4 using immunohistochemistry for 5-lipoxygenase (5-LO), the rate-limiting enzyme in LTB4 biosynthesis. Very little 5-LO was observed in normal mouse pancreatic acinar cells. However, retrograde pancreatic ductal infusion of bile acids caused a marked increase in the amount of 5-LO immunostaining in acinar cells and in the number of acinar cells exhibiting 5-LO immunoreactivity. Pancreatic ducts and islets exhibited little if any 5LO immunoreactivity. In bile acid-treated animals, 5-LO immunoreactivity was limited to the basal poles of the acinar cells, consistent with the distribution of rough endoplasmic reticulum (rER). A similar pattern of 5-LO immunoreactivity was seen in human pancreas samples from acute pancreatitis patients. Additional evidence in favor of the concept that acinar cells are the source of bile acid-induced LTB4 was obtained using mouse pancreatic acini in vitro. The bile acid, taurolithocholate acid 3-sulfate (TLCS; 500 μM), stimulated time-dependent LTB4 release from pancreatic acini in vitro. Conclusions: We conclude that bile acids damage the pancreas in part by stimulating increased 5-LO activity in pancreatic acinar cells resulting in release of LTB4 which subsequently activates TRPV1 in primary sensory neurons to cause neurogenic inflammation and acute pancreatitis.
Sa1850 First Results of the Barosense ACE Stapler Procedure for the Treatment of Morbid Obesity: Effect on Food Intake and Satiety Mark van Avesaat, Givan F. Paulus, José M. Conchillo, Nicole D. Bouvy, Ad Masclee
Sa1852
Conventional bariatric surgery is a very effective therapy for weight loss but has several risks and limitations. Recently alternative non-incisional endoscopic procedures have been introduced such as the BaroSense Articulating Circular Endoscopic (ACE) Stapler technique. This trans-oral procedure intends to reduce the capacity of the stomach to expand by endoscopically creating plications in the region of the fundus and greater curvature. In this first explorative study we tried to provide more information about the potential efficacy and mechanism of weight loss of the BaroSense ACE stapler procedure. Methods: This prospective study was performed in 10 morbidly obese patients (4 women, mean age 41±10 years, mean BMI 39.6±2.8 kg/m2) who underwent the BaroSense ACE stapler. Patients were studied prior to and one month after the operation. All procedures went without any complications and patients were discharged one day after the operation. Gastric emptying (by 13C octanoic acid breath test) and satiety (VAS) were measured at different time points before and after the intake of a standardized, fixed breakfast meal (t=0, breakfast consisted of 200kcal and 100mg 13C octanoic acid was added). Food intake was assessed by offering an ad libitum meal at t=240 min. Comparisons of gastric emptying half time and food intake were analyzed using paired samples t-tests whereas all VAS scores were examined by using the repeated measures ANOVA. All results are expressed as mean±S.E.M. Results: The included patients showed loss of 19.9±5.7% excess BMI one month postoperatively. Patients did not report any gastrointestinal complaints, but satiety AUC was significantly increased 1 month after the procedure compared to before (AUC 68.8±8.9 and 48.1±9.4 p ,0.02). Ad libitum food intake decreased significantly from 842.8±45.9 to 441.8±100.1 kcal (preop vs postop, p,0.01). No differences were observed in gastric emptying half time (141.3±5.9 versus 138.7±12.3 minutes, p.0.05) Conclusion: Our data indicate that endoscopic reduction of the stomach volume by the BaroSense ACE stapler procedure results in significant weight loss, increase in satiety and a decrease in food intake one month postoperatively. Although capacity of the stomach for relaxation is impaired, gastric emptying of a standard and fixed test meal was not affected. These first explorative data indicate that the BaroSense ACE stapler is a potentially very promising technique that effectively reduces food intake and affects satiety but does not interfere with gastric emptying. Inclusion of larger numbers of patients and more prolonged follow up of BaroSense ACE stapler procedures is needed.
Reduction of Lipotoxicity by Two Distinct Lipase Inhibitors Improves Local, Systemic, Inflammatory Outcomes and Mortality in a Model of Biliary Severe Acute Pancreatitis (SAP) Without Interfering With the Primary Insult Chandra Durgampudi, Pawan Noel, Krutika Patel, Rachel Cline, Vivek Mishra, James P. DeLany, Ram N. Trivedi, Chathur Acharya, Deepthi Jaligama, Sarah Navina, Vijay Singh BACKGROUND AND AIMS: Our recent studies suggest that lipolysis of intrapancreatic fat, which is increased in obesity may be associated with the worse outcomes of acute pancreatitis (AP). High unsaturated fatty acid (UFA) concentrations are noted in the debridement fluid of SAP patients. To further study this in a model relevant to human biliary AP, we studied the efficacy of 2 lipase inhibitors; Orlistat and Cetelistat on parameters of severity and etiology of AP. METHODS: AP was induced by infusing glyceryl trilinoleate (GTL, 0.1ml )into the pancreatic duct of male Wistar rats (300-400gm) with or without dissolved orlistat or cetelistat. The duct was ligated at the end of the infusion. Animals were followed till 5 days or mortality, whichever came first. A p value of ,0.05 was regarded as significant when comparing two groups. RESULTS: GTL infusion resulted in severe hemorrhagic AP (70-80% necrosis) with 100% mortality in 24 hours and a high serum bilirubin (5.9± 1.0 vs. 0.9±0.2 mg/dl vs. controls) supportive of severe biliary AP. The significant changes compared to controls included hyperlipasemia (6430±3198 U/L vs. 94±17 U/L), hypercytokinemia (IL-1 beta 367±152 vs. 20±4 pg/ml and KC/GRO 13266±2452 vs. 650±40 pg/ml) , elevated non-esterified fatty acids (NEFA; 2578±1227 μM vs. 220±35 μM ), UFA (1561±726μM vs. 94±17μM), linoleic acid (LA; 827±368 μM vs. 54±5 μM) renal failure (blood urea nitrogen [BUN] 88±22 vs. 19±1mg/dl) and Lung injury (8±2.1 TUNEL positive cells/HPF vs. 0.3±0.1). Both lipase orlistat and cetelistat significantly reduced these (IL1beta; 45±24 pg/ml and 66±30 pg/ml, KC/GRO; 1044±137 and 1400±545 pg/ml, serum lipase; 169±24 U/L and 526±515 U/L, NEFA; 548±71μM and 455±57μM, UFA; 312±46μM and 241±57μM, LA; 174±25μM and 112±28μM, BUN; 18.7±1.4 and 18.1±6.0, Lung injury; 0.4±0.1 and 1.6±0.5 TUNEL positive cells/HPF respectively and significantly reduced 5 day mortality (0/10 in the orlistat group and 1/10 in the cetelistat group) with no evidence of hemorrhagic AP except in the one animal which died in the cetelistat group. There was no reduction in the serum bilirubin (6.0±1.2 mg/dl and 5.3±1.8mg/dl) or amylase at day 1 by either orlistat or cetelistat suggestive of ongoing biliary AP. Oil red O staining revealed several areas of red staining in the rats receiving intraductal GTL. CONCLUSIONS: Consistent with their role as lipase inhibitors, both orlistat and cetelistat reduced serum lipase, NEFA, UFA and LA. However the improvement in local injury, inflammatory response, organ failure and survival by the lipase inhibitors without affecting parameters of biliary pancreatitis (serum bilirubin, amylase) and irrespective of the accumulation of intrapancreatic lipid pools suggests that pancreatic lipase inhibition improves the outcomes of SAP in obesity without affecting the primary insult. Sa1853 Ethanol Feeding Down-Regulates Whereas Experimental Alcoholic Pancreatitis Stimulates Autophagy Jinliang Ni, Samuel W. French, Anna S. Gukovskaya, Ilya Gukovsky, Olga A. Mareninova Background & Aims: Alcohol abuse is a major risk factor for pancreatitis, but the mechanism of alcoholic pancreatitis remains elusive. It is not clear how does ethanol predispose to pancreatitis; and at the same time, why ethanol feeding alone does not cause pronounced pancreatic injury (at least, in rodents) and, therefore, must be combined with another stressor to cause disease. Autophagy is activated in non-alcoholic pancreatitis, but defective lysosomal function makes autophagic flux inefficient, underlying key pancreatitis pathologies. Here we investigate the effects of ethanol feeding and experimental alcoholic pancreatitis on autophagy in pancreas. Methods: Mice received ethanol-containing or control Lieber-DeCarli diet for 6 weeks followed or not by 7 i.p. injections of low-dose (3 μg/kg) cerulein (CR). We measured the effects of ethanol alone and the alcoholic pancreatitis on Atg proteins critical for autophagosome formation: ULK1/Atg1, initiating this process; Atg5 and Beclin1/ Atg6, mediating autophagosome maturation; LC3/Atg8, a protein key for autophagosome closure in the process of which its' cytosolic LC3-I form is lipidated to LC3-II, which selectively localizes to autophagosomes; and Atg4, a protease that mediates delipidation of LC3-II necessary for its recycling. Results: Ethanol feeding markedly activated AMPK, leading to ULK1 phosphorylation that indicates autophagy initiation. By contrast, ethanol greatly down-regulated pancreatic LC3-II, as shown by immunoblotting and immunofluorescence. Accordingly, EM showed fewer autophagic vacuoles in pancreas of ethanol-fed mice. In search of underlying mechanism, we found that ethanol markedly increased both the level and activity of Atg4, indicating that ethanol fails to stimulate autophagosome formation because of excessive LC3-II delipidation. Differently, in ethanol+ low-dose CR pancreatitis, Atg4 dramatically decreased while LC3-II level and autophagic vacuoles increased. Thus, ethanol alone inhibits whereas alcoholic pancreatitis stimulates autophagy. At the same time, ethanol alone and alcoholic pancreatitis both decreased the levels of the lysosomal membrane
Satiety scores 1 month postoperative were significantly increased compared to preoperative scores (# p,0.05, * p,0.01, ** p,0.001) Sa1851 Bile Acid-Induced Acute Pancreatitis Is Mediated by Acinar Cell Leukotriene B4 Secretion Rafiq A. Shahid, Steven R. Vigna, Rodger A. Liddle Background: Retrograde perfusion of the pancreatic duct with bile acids causes acute pancreatitis of the head of the pancreas and is a model of biliary pancreatitis in mice. We have previously shown that bile acid-induced pancreatitis can be reduced by pharmacological blockade of the Transient Receptor Potential Vanilloid 1 receptor (TRPV1) on primary sensory nerves to prevent neurogenic inflammation. However, the endogenous ligand responsible for activation of TRPV1 in pancreatitis is unknown. We proposed that leukotriene B 4 (LTB4),which has been shown to activate TRPV1 in vitro, may be a critical mediator of TRPV1 activation and pancreatitis. Methods and Results: In support of this hypothesis we demonstrated that (1) LTB4 levels in the pancreas are markedly elevated in acute pancreatitis, (2) LTB4 infused into the celiac artery causes acute pancreatitis, (3) inhibition of LTB4 biosynthesis prevents inflammation, and (4) LTB4-induced pancreatitis is prevented by TRPV1 blockade. Because acute pancreatitis is accompanied by neutrophil infiltration and neutrophils are a rich source of LTB4, it was assumed that neutrophils account for the increased LTB4 levels in bile acid-induced pancreatitis. However, this would not explain
AGA Abstracts
S-320