Lesions of pancreatitis in obese rats decrease after bariatric surgery

Lesions of pancreatitis in obese rats decrease after bariatric surgery

S14 Abstracts / Pancreatology 15 (2015) S1eS141 Whereas IKK/ NF-kB signaling has been extensively studied in the epithelial compartment of the pancr...

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S14

Abstracts / Pancreatology 15 (2015) S1eS141

Whereas IKK/ NF-kB signaling has been extensively studied in the epithelial compartment of the pancreas, much less is known about its role in the stromal compartment. This is particularly true for pancreatic stellate cells, which are considered to play a prominent role during fibrosis. Aims: To determine the contribution of stromal IKK/ NF-kB signaling, particularly in pancreatic stellate cells, to the pathogenesis of pancreatitis. Patients & methods: Wild type mice and different mouse lines with a targeted deletion of the regulatory IKK subunit NEMO/ IKKg in the stromal compartment of the pancreas (e.g. Col1a2-CreERT or GFAP-Cre / NEMOflox mice) were subjected to mild chronic caerulein pancreatitis. The pancreata were analyzed on the histological and molecular level for inflammation and fibrosis, cell death and proliferation, as well as for cellular differentiation markers. Results: When using a modified protocol of a mild chronic caerulein pancreatitis, wild type mice showed only a small amount of fibrotic tissue and recovered almost fully after the discontinuation of caerulein application. In contrast, pancreata with an ablation of NEMO in mesenchymal cells showed an enhanced expression of chemokines, accumulation of CD45þ infiltrating cells, proliferation of mesenchymal cells, and extensive fibrosis. Conclusion: Our results provide evidence for a protective role of canonical IKK/ NF-kB signaling in the mesenchymal compartment during the pathogenesis of chronic pancreatitis.

1154. Analysis of the structural and sensory innervation in the mouse pancreas Omer Cemil Saricaoglu, Ihsan Ekin Demir, Helmut Friess, Güralp O. Ceyhan Department of Surgery, Klinikum Rechts der Isar, TU München, Germany Introduction: Human pancreatic cancer/PCa and chronic pancreatitis/ CP are characterized by neural hypertrophy, neural sprouting, and reduced sympathetic innervation. However, our knowledge on the innervation of current murine models of PCa and CP and even of normal mouse pancreas is very scarce. Aims: In this study, we aimed to systematically analyze the structure, distribution and quality of nerves in the mouse pancreas. Materials & methods: Whole pancreata derived from 6-8-week-old C57BL/6J mice (n¼10) were paraffin-embedded and entirely sectioned into 3mm consecutive sections from the anterior to the posterior/retroperitoneal plane. All sections were immunostained with the pan-neural-marker PGP 9.5, with the sensory fibre markers substance-P/SP and calcitoningene-related-peptide/CGRP and were subject to systematic morphometric analysis. Results: Nerves enter the mouse pancreas around pericapsular lymphoid structures and penetrate into the tissue along vessels and interlobular septae. The size and the density of nerves in the pancreatic head and corpus were significantly greater than in the pancreatic tail. The majority of nerves were localized in the anterior and posterior surface of the head and the anterior surface of the corpus. The proportion of sensory fibres was ca. 8% of all nerve fibres in the mouse pancreas and did not vary between the head, corpus and tail. 74% of sensory fibres were localized in the pancreatic head, 19% in the corpus and 7% in the tail. Conclusion: Murine pancreatic head has the highest density of pancreatic nerves. Overall, due to its intraperitoneal and perilymphoid localization, the mouse pancreas bears a substantially different structural innervation pattern when compared to the human pancreas.

909. Specific impact of hyperglycaemia on the course of two different forms of chronic pancreatitis Tassilo Müller-Graff 1, Niklas Knapp 1, Brit Fitzner 2, Robert Jaster 2, Brigitte Vollmar 1, Dietmar Zechner 1 1 €tsmedizin Institute for Experimental Surgery Rostock, Universita Rostock, Germany 2 €tsmedizin Rostock, Department for Gastroenterology, Universita Germany

Introduction: A temporary or sustained hyperglycaemia can be observed in about 83% of patients with chronic pancreatitis. However, it is unknown to what extent hyperglycaemia has an influence on the course of different forms of chronic pancreatitis. Aims: The purpose of this study is to evaluate the influence of hyperglycaemia on the progression of a cerulein-induced chronic pancreatitis and on an autoimmune pancreatitis. Materials & methods: We induced hyperglycaemia by repetitive i.p.injection of 50mg/kg streptozotocin in C57BL/6J mice and initiated chronic pancreatitis by redundant administration of caerulein. We also induced hyperglycaemia in MRL/Mp mice, which develop autoimmune pancreatitis due to a genetic predisposition. We compared tissue damage (atrophy, cell death, fibrosis) and the extent of inflammation (granulocytes, T-lymphocytes) in hyperglycaemic and normoglycaemic mice in these two mouse models of chronic pancreatitis. Results: Hyperglycaemia lead to increased inflammation in the pancreas during caerulein-induced pancreatitis. Furthermore the pancreas of these mice compared to normoglycaemic animals was characterized by significantly increased cell death, reinforced atrophy and extensive collagen deposition. This massive deterioration during the course of pancreatitis is reflected by the histological findings. In contrast to this animal model, hyperglycaemia did not lead to an aggravation of autoimmune pancreatitis but even to a marginal decrease of the histological score and therefore to an improvement of the disease progress. Conclusion: Based on these results, we conclude that hyperglycaemia aggravates caerulein-induced chronic pancreatitis, but surprisingly leads rather to an improvement of autoimmune pancreatitis.

923. Lesions of pancreatitis in obese rats decrease after bariatric surgery Vinciane Rebours 1, Jean-Baptiste Cavin 2, Konstantinos Arapis 3, e Bado 2, V eronique Albano 4, Jean Marmuse 3, Andr Philippe Ruszniewski 1, Maude Le Gall 2, Anne Couvelard 4 1

Pancreatology Unit Beaujon Hospital Clichy France, France  Paris 7 France, France Inserm UMR1149, CRI, Universite 3 Surgery Unit, Bichat Hospital, Paris, France 4 Pathology Unit, Bichat Hospital, Paris, France 2

Introduction: Obesity is a risk factor for pancreatitis: pro-inflammatory cytokines induced by the adipose tissue, insulin resistance, hyperinsulinism. Bariatric surgery is one of the more efficient treatments of morbid obesity. Aims: To assess pancreatic endocrine and exocrine lesions in obese rats (high fat diet, HFD) and to analyze consequences of bariatric surgery on these lesions. Materials & methods: 30 male Wistar rats were included: obese ( HFD) or non obese (ND, normal diet). A part of HFD rats underwent bariatric surgery: by pass (BP) or sleeve gastrectomy (SG). Four groups were constituted: Gr1, HFD (n¼8); Gr2, HFD-BP (n¼11); Gr3 HFD-SG (n¼5); Gr4,

Abstracts / Pancreatology 15 (2015) S1eS141

ND (n¼8). After sacrifice, weight, % of weight loss, glycoregulation and pathological exam were assessed: adipocytes islets, fibrosis, acino-ductal metaplasia, abnormality of Langerhans islets (HHF: hypertrophy, hypervascularisation, fibrosis), and hemosiderin deposition. Results: A comparison between HFD and ND rats showed an increase of HHF and hemosiderin deposition in HFD (p¼0,0012 and p¼0,0078). The increase of the weight in HFD was associated with abnormal glycoregulation (r¼ 0,44, p¼0,08). In all groups, HHF lesions were associated with hemosiderin deposition (r¼0,88, p<0,0001). After bariatric surgery , it was observed in HFD rats a decrease of 1/ HHF lesions (p¼0,001), 2/ hemosiderin deposition (p¼0,0006) 3/ amount of adipocytes (p¼0,01). In HFD-BP, HHF lesions and hemosiderin deposition were associated with acino-ductal metaplasia (p¼0,08 et p¼0,02). The number of acino-ductal metaplasia was higher in rats with higher weight before sacrifice (p¼0,03). Conclusion: Pancreas specimens of obese rats show pancreatitis lesions (acino-ductal metaplasia, fibrosis) in acinar location and in the endocrine-exocrine interface.

1186. Imbalance of mucus homeostasis in chronic pancreatitis zs 1, Julia Duerr 2, Zhe Zhou-Shuckow 2, Jolanthe Schatterny 2, Anita Bala Laszlo Tiszlavicz 3, Istvan Balazs Nemeth 4, Balazs Kui 1, Zoltan Rakonczay, Jr. 1, Marcus Mall 2, Peter Hegyi 1, 5 1

First Department of Medicine, University of Szeged, Szeged, Hungary Department of Translational Pulmonology, Translational Lung Research Center, University of Heidelberg, Heidelberg, Germany 3 Department of Pathology University of Szeged, Szeged, Hungary 4 Department of Dermatology and Allergology, Hungary 5 MTA-SZTE Translational Gastroenterology Research Group, Szeged, Hungary 2

Introduction: Qualitative and/or quantitative changes of mucus in the pancreas are important factors both in the initiation and progression of chronic pancreatitis (CP), however, the underlying defective mucus phenotype is poorly understood. Aims: Our objectives were to investigate the mucus content both in human CP and experimental pancreatitis models and to correlate the mucus changes with ductal fluid secretion and pancreatic fibrosis. Materials & methods: Human CP tissue samples were collected from surgically resected pancreata, whereas murine CP was induced by administration of 6x50mg/kg cerulein 3 series/week for 4 weeks. Morphometric analysis of mucus and fibrosis was carried out. Gene expression of mucin subtypes was investigated. Fluid secretion into the closed luminal space of the cultured pancreatic ducts was analysed using swelling method. Results: The mucus volume density (Vdmuc) of human PDEC was significantly higher in CP than in controls, in case of smaller ducts (ductal diameter<100mm: 1.21±0.13nl/mm2 and 0.37±0.05nl/mm2, respectively). Similarily, mouse PDEC showed significantly higher Vdmuc in CP than in controls, especially in ducts with smaller diameter (ductal diameter<80mm: 0.72±0.06nl/mm2 vs. 0.005±0.0002nl/mm2). Gene expression of muc6 was ~1000-fold upregulated in mouse and 17-fold upregulated in human CP. Ductal fluid seretion of cerulein treated mice was impaired after 3 weeks of treatment. Analysis of time course changes showed association between tissue damage and impaired epithelial mucus and fluid secretion. Conclusion: There is a clear imbalance of mucus homeostasis during development of CP. Our data suggest that these changes are in association with decreased fluid secretion and increased fibrosis, however, the causeand-effect relationship needs to be determined.

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1239. Cigarette smoke extract inhibits fluid and HCOe3 secretion and CFTR activity in guinea pig pancreatic ductal cells l 1, Krisztina To ria Venglovecz 2, Eleono ra Ga th 1, Petra Pallagi 1, Vikto n Rakonczay 1, zsef Mal eth 1, Dezs Csupor 3, Zolta Andrea Schnúr 1, Jo P eter Hegyi 1, 4 1

University of Szeged, First Department of Medicine, Hungary University of Szeged, Department of Pharmacology and Pharmacotherapy, Hungary 3 University of Szeged, Department of Pharmacognosy, Hungary 4 MTA-SZTE Translational Gastroenterology Research Group, Szeged, Hungary 2

Introduction: Smoking represents an independent risk factor for the development of chronic pancreatitis (CP). It is well documented that secretion of pancreatic ductal alkaline fluid (which is regulated mostly by the anion exchanger and CFTR) is diminished in CP. Aims: In this study we would like to understand whether smoking has any effects on pancreatic ductal fluid and HCO-3 secretion. Materials & methods: Intra/interlobular pancreatic ducts were isolated from guinea pig pancreas. Cigarette smoke extract (CSE) was prepared by smoking of 3 cigarettes into 40ml distilled water by a smoking machine. Three different doses (20, 40 and 80mg/ml) were diluted using the stock solution. Basal and forskolin-stimulated fluid secretion was measured by video microscopy. Intracellular pH and Ca2þ concentration were evaluated by microfluorometry. Luminal anion exchange activity was determined by the chloride withdrawal technique using microperfusion. CFTR currents were detected by whole cell configuration of patch clamp technique. Results: CSE dose dependently decreased forskolin-stimulated fluid secretion in guinea pig pancreatic ducts, bicarbonate secretion (20mg/ml by 17.3%, 40mg/ml by 40.5%) and forskolin-stimulated Cl- current of CFTR Cl- channel (20mg/ml by 44.5 %, 40mg/ml by 69.3 % and 80mg/ml by 81.3%). Moreover, CSE induced dose-dependent intracellular calcium elevation suggesting that some of the inhibitory effects may be regulated by calcium signalling. Conclusion: CSE inhibits pancreatic ductal fluid and HCO-3 secretion and the activity of the CFTR which may play role in the smoke-induced pancreatic damage. This study was supported by OTKA, MTA and NFÜ/  TAMOP.

1258. Functional significance of SPINK1 promoter variants in chronic pancreatitis  Kereszturi, Miklo s Sahin-To th Andrea Geisz, Monique H.M. Derikx, Eva Boston University, Department of Molecular and Cell Biology, United States Introduction: The serine protease inhibitor Kazal type 1 (SPINK1) gene encodes a trypsin inhibitor responsible for protecting the pancreas from premature trypsinogen activation and pancreatitis. Recent genetic and functional studies indicated that promoter variants in the SPINK1 gene might contribute to chronic pancreatitis. Aims: Our aim was to investigate the functional effects of 17 SPINK1 promoter variants using luciferase reporter gene expression assay in four different cell lines, including three pancreatic acinar cell lines (rat AR42J with or without dexamethasone-induced differentiation and mouse 2666) and HEK 293T cells.