Pathogenesis Of Chronic Pancreatitis Research Articles

A small molecule inhibitor of NFκB blocks ER stress and the NLRP3 inflammasome and prevents progression of pancreatitis.

The underlying molecular mechanism that leads to development of chronic pancreatitis remains elusive. The aim of this study is to understand the downstream inflammatory signaling involved in progression of chronic pancreatitis, and to use withaferin A (WA), a small molecule inhibitor of nuclear factor κB (NFκB), to prevent progression of chronic pancreatitis. Two different protocols were used to induce pancreatitis in mice: standard and stringent administration of cerulein. The severity of pancreatitis was assessed by means of pancreatic histology and serum amylase levels. Immunohistochemistry and flow-cytometric analysis was performed to visualize immune cell infiltration into the pancreas. Real-time PCR and Western blot were used to analyze the downstream signaling mechanism involved in the development of chronic pancreatitis. The severity of cerulein-induced pancreatitis was reduced significantly by WA, used as either preventive or curative treatment. Immune cell infiltration into the pancreas and acinar cell death were efficiently reduced by WA treatment. Expression of proinflammatory and proapoptotic genes regulated by NFκB activation was increased by cerulein treatment, and WA suppressed these genes significantly. Sustained endoplasmic reticulum stress activation by cerulein administration was reduced. NLRP3 inflammasome activation in cerulein-induced pancreatitis was identified, and this was also potently blocked by WA. The human pancreatitis tissue gene signature correlated with the mouse model. Our data provide evidence for the role of NFκB in the pathogenesis of chronic pancreatitis, and strongly suggest that WA could be used as a potential therapeutic drug to alleviate some forms of chronic pancreatitis.

Chronic pancreatitis: An international draft consensus proposal for a new mechanistic definition.

A definition of chronic pancreatitis (CP) is needed for diagnosis and distinguishing CP from other disorders. Previous definitions focused on morphology. Advances in epidemiology, genetics, molecular biology, modeling and other disciplines provide new insights into pathogenesis of CP, and allow CP to be better defined. Expert physician-scientists from the United States, India, Europe and Japan reviewed medical and scientific literature and clinical experiences. Competing views and approaches were debated until a new consensus definition was reached. CP has been defined as 'a continuing inflammatory disease of the pancreas, characterized by irreversible morphological change, and typically causing pain and/or permanent loss of function'. Focusing on abnormal morphology makes early diagnosis challenging and excludes inflammation without fibrosis, atrophy, endocrine and exocrine dysfunction, pain syndromes and metaplasia. A new mechanistic definition is proposed--'Chronic pancreatitis is a pathologic fibro-inflammatory syndrome of the pancreas in individuals with genetic, environmental and/or other risk factors who develop persistent pathologic responses to parenchymal injury or stress.' In addition, "Common features of established and advanced CP include pancreatic atrophy, fibrosis, pain syndromes, duct distortion and strictures, calcifications, pancreatic exocrine dysfunction, pancreatic endocrine dysfunction and dysplasia." This definition recognizes the complex nature of CP, separates risk factors from disease activity markers and disease endpoints, and allows for a rational approach to early diagnosis, classification and prognosis. Initial agreement on a mechanistic definition of CP has been reached. This definition should be debated in rebuttals and endorsements, among experts and pancreatic societies until international consensus is reached.

The consequences of cholecystectomy

to analyze the consequences of cholecystectomy. 348 patients were under observation within 10 years after cholecystectomy. Surgery for destructive and chronic cholecystitis was performed in 115 and 233 patients respectively. The consequences of cholecystectomy were assessed using bile acids level in blood plasma, stomach and duodenal pressure, pancreatic and stomach changes. It was established that lithocholic, deoxycholic, taurodeoxycholic acids were increased by 44% within 10 years after surgery. At the same time glycocholic and tauroursodeoxycholic acids were decreased by 21.5% in 5 years after surgery. Bile acids level changes were associated with changes of stomach and duodenal pressure. The most pronounced disorders were observed in distal duodenum. There was more than 2.8-fold excess of normal pressure in this area. Duodenal hypertension was accompanied by pancreatic ducts enlargement in 9.5% of cases and increased echogenicity in 93% of cases. Changes of the level and proportion of blood plasma bile acids and hypertension in upper gastrointestinal tract are the most important in chronic pancreatitis pathogenesis after cholecystectomy. Such conditions occur within first 3 years after surgery.

Extensive molecular analysis suggested the strong genetic heterogeneity of idiopathic chronic pancreatitis.

Rationale: Genetic features of Chronic Pancreatitis (CP) have been extensively investigated mainly testing genes associated to the trypsinogen activation pathway. However, different molecular pathways involving other genes may be implicated in CP pathogenesis. Objectives: 80 patients with Idiopathic CP were investigated using Next Generation Sequencing approach with a panel of 70 genes related to six different pancreatic pathways: premature activation of trypsinogen; modifier genes of Cystic Fibrosis phenotype; pancreatic secretion and ion homeostasis; Calcium signalling and zymogen granules exocytosis; autophagy; autoimmune pancreatitis related genes. Results: We detected mutations in 34 out of 70 genes examined; 64/80 patients (80.0%) were positive for mutations in one or more genes, 16/80 patients (20.0%) had no mutations. Mutations in CFTR were detected in 32/80 patients (40.0%) and 22 of them exhibited at least one mutation in genes of other pancreatic pathways. Of the remaining 48 patients, 13/80 (16.3%) had mutations in genes involved in premature activation of trypsinogen and 19/80 (23.8%) had mutations only in genes of the other pathways: 38/64 patients positive for mutations showed variants in two or more genes (59.3%). Conclusions: Our data, although to be extended with functional analysis of novel mutations, suggest a high rate of genetic heterogeneity in chronic pancreatitis and that trans-heterozygosity may predispose to the idiopathic CP phenotype.

Primary outgrowth cultures are a reliable source of human pancreatic stellate cells

Recent advances demonstrate a critical yet poorly understood role for the pancreatic stellate cell (PSC) in the pathogenesis of chronic pancreatitis (CP) and pancreatic cancer (PC). Progress in this area has been hampered by the availability, fidelity, and/or reliability of in vitro models of PSCs. We examined whether outgrowth cultures from human surgical specimens exhibited reproducible phenotypic and functional characteristics of PSCs. PSCs were cultured from surgical specimens of healthy pancreas, CP and PC. Growth dynamics, phenotypic characteristics, soluble mediator secretion profiles and co-culture with PC cells both in vitro and in vivo were assessed. Forty-seven primary cultures were established from 52 attempts, demonstrating universal α-smooth muscle actin and glial fibrillary acidic protein but negligible epithelial surface antigen expression. Modification of culture conditions consistently led to cytoplasmic lipid accumulation, suggesting induction of a quiescent phenotype. Secretion of growth factors, chemokines and cytokines did not significantly differ between donor pathologies, but did evolve over time in culture. Co-culture of PSCs with established PC cell lines resulted in significant changes in levels of multiple secreted mediators. Primary PSCs co-inoculated with PC cells in a xenograft model led to augmented tumor growth and metastasis. Therefore, regardless of donor pathology, outgrowth cultures produce PSCs that demonstrate consistent growth and protein secretion properties. Primary cultures from pancreatic surgical specimens, including malignancies, may represent a reliable source of human PSCs.

Gremlin1 and chronic pancreatitis: a new clinical target and biomarker?

Chronic pancreatitis (CP) is a progressive inflammatory condition triggered by the loss of exocrine pancreatic acini and fibrosis or scarring of pancreas tissue [1]. The exocrine pancreas comprises about 90 % of total pancreas and releases digestive enzymes such as chymotrypsin, amylase and lipase in response to a meal. CP develops in 16 % of patients presenting with acute pancreatitis, a number which increases to 38 % upon second admission. The most common symptom of CP is abdominal pain, which can be both intermittent and persistent. Furthermore, 95 % of CP patients present with alcoholic or idiopathic disease [1]; however, excessive consumption of alcohol alone may not be the cause of CP. Additional causes of CP include gallstones, exposure to volatile hydrocarbons, viral infection and genetic mutations [2]. There are various genetic forms of CP including gain-of-function mutations in genes such as Prss1 which results in a form of trypsin that is resistant to degradation and can lead to an autosomal-dominant hereditary form of CP [1]. In contrast, loss-of-function mutations in genes such as Spink1 and Cftr, which is involved in the inactivation of pancreatic trypsin, are also associated with CP. The overall survival rate for CP patients is only 50 % at 20–25 years from diagnosis [3], and CP patients also have an increased risk of developing pancreatic cancer [4]. Current treatments for CP involve pain management with paracetamol and non-steroid anti-inflammatory drugs as first line, followed by mild opioids such as tramadol. An important clinical feature of CP is steatorrhea, caused by reduced absorption of fat in the intestine. Supplementation of pancreatic enzymes such as lipase, together with H2 histamine antagonists, is used to reduce this malabsorption of lipids [1]. Micronutrient therapy containing antioxidants such as Antox® (containing methyl and thiol moieties, as well as methionine and vitamin C) is now being tested, as it has been shown to control the pain and attacks associated with CP [1]. The pathogenesis of CP is believed to be associated with inappropriate pancreatic enzyme activation and clearance from the acinar cells. Increased pancreatic Ca levels as a result of excessive consumption of alcohol or other causes is common in CP, with calcifying protein deposits implicated in the blockage of the acinar ducts, leading to digestive enzyme accumulation and subsequent inflammation. Other evidence suggests that noxious agents such as alcohol are directly toxic to the acinar cells and may also trigger the activation of pancreatic stellate cells [5]. An important element of the pathogenesis of CP is fibrosis, which can occur via sustained activation of pancreatic stellate cells that migrate to sites of tissue damage and secrete excess extracellular matrix proteins, causing fibrosis or scarring [6]. Factors that drive this fibrotic response include lipid peroxidation products released by acinar cells and TGF-β1 release by reactive oxygen species (ROS)-activated mast cells that infiltrate the pancreas as part of the inflammatory response to CP [1]. Progression of fibrosis in CP is associated with the loss of acinar and islet cells, leading to both exocrine and endocrine pancreas dysfunction. There are currently no effective therapies to prevent or reverse CP [7]. Given the insidious nature of CP, together with the increased mortality rate and pancreas cancer risk, improved treatment options for reversing the progressive fibrosis associated with this disease are urgently needed. To this end, new molecular targets that are involved in the onset and progression of fibrosis associated with CP need to be identified. * Derek P. Brazil d.brazil@qub.ac.uk

Antioxidant therapy for pain reduction in patients with chronic pancreatitis: a systematic review and meta-analysis.

Oxidative stress is strongly implicated in the pathogenesis of chronic pancreatitis (CP); however, clinical studies evaluating antioxidant therapy (AOT) in the management of CP pain have yielded conflicting results. The aim of this meta-analysis was to evaluate the efficacy of AOT in pain reduction in CP patients. Two authors independently conducted a comprehensive literature search from inception to December 2013. Relative risk (RR) and 95% confidence intervals (CIs) were calculated using the Mantel-Haenszel and DerSimonian-Laird methods. Eight studies involving 446 patients (234 in AOT and 212 in control group) were included. Overall, CP patients who received AOT had significant reduction in pain compared with the control group (RR, 0.73; 95% CI, 0.58-0.91; P = 0.006). In the subgroup analysis, studies with predominantly alcoholic CP patients (RR, 0.60; 95% CI, 0.47-0.77; P < 0.0001) and studies with mean age of patients 42 years or older (RR, 0.66; 95% CI, 0.49-0.89; P = 0.006) showed significant benefit of AOT over placebo. This is the first meta-analysis to summarize all the available evidence and show benefit of AOT in pain reduction in CP patients. There is a pressing need for well-designed larger studies with longer follow-up to better define the patient and disease factors favoring response, the optimal formulation, and duration of AOT.

Retraction note: Reanalysis of the gene expression profile in chronic pancreatitis via bioinformatics methods.

Diagnosis at an early stage of chronic pancreatitis (CP) is challenging. It has been reported that microRNAs (miRNAs) are increasingly found and applied as targets for the diagnosis and treatment of various cancers. However, to the best of our knowledge, few published papers have described the role of miRNAs in the diagnosis of CP. We downloaded gene expression profile data from the Gene Expression Omnibus and identified differentially expressed genes (DEGs) between CP and normal samples of Harlan mice and Jackson Laboratory mice. Common DEGs were filtered out, and the semantic similarities of gene classes were calculated using the GOSemSim software package. The gene class with the highest functional consistency was selected, and then the Lists2Networks web-based system was used to analyse regulatory relationships between miRNAs and gene classes. The functional enrichment of the gene classes was assessed based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway annotation terms. A total of 405 common upregulated DEGs and 7 common downregulated DEGs were extracted from the two kinds of mice. Gene cluster D was selected from the common upregulated DEGs because it had the highest semantic similarity. miRNA 124a (miR-124a) was found to have a significant regulatory relationship with cluster D, and DEGs such as CHSY1 and ABCC4 were found to be regulated by miR-124a. The GO term of response to DNA damage stimulus and the pathway of Escherichia coli infection were significantly enriched in cluster D. DNA damage and E. coli infection might play important roles in CP pathogenesis. In addition, miR-124a might be a potential target for the diagnosis and treatment of CP.

Extragastric manifestations of Helicobacter pylori infection: Possible role of bacterium in liver and pancreas diseases.

Helicobacter pylori (H. pylori) is an ancient microorganism that has co-evolved with humans for over 60000 years. This bacterium typically colonizes the human stomach and it is currently recognized as the most common infectious pathogen of the gastroduodenal tract. Although its chronic infection is associated with gastritis, peptic ulcer, dysplasia, neoplasia, MALT lymphoma and gastric adenocarcinoma, it has been suggested the possible association of H. pylori infection with several extragastric effects including hepatobiliary and pancreatic diseases. Since a microorganism resembling H. pylori was detected in samples from patients with hepatobiliary disorders, several reports have been discussed the possible role of bacteria in hepatic diseases as hepatocellular carcinoma, cirrhosis and hepatic encephalopathy, nonalcoholic fatty liver disease and fibrosis. Additionally, studies have reported the possible association between H. pylori infection and pancreatic diseases, especially because it has been suggested that this infection could change the pancreatic physiology. Some of them have related a possible association between the microorganism and pancreatic cancer. H. pylori infection has also been suggested to play a role in the acute and chronic pancreatitis pathogenesis, autoimmune pancreatitis, diabetes mellitus and metabolic syndrome. Considering that association of H. pylori to liver and pancreas diseases needs further clarification, our work offers a review about the results of some investigations related to the potential pathogenicity of H. pylori in these extragastric diseases.

Endoplasmic Reticulum Stress Is Chronically Activated in Chronic Pancreatitis

The pathogenesis of chronic pancreatitis (CP) is poorly understood. Endoplasmic reticulum (ER) stress has now been recognized as a pathogenic event in many chronic diseases. However, ER stress has not been studied in CP, although pancreatic acinar cells seem to be especially vulnerable to ER dysfunction because of their dependence on high ER volume and functionality. Here, we aim to investigate ER stress in CP, study its pathogenesis in relation to trypsinogen activation (widely regarded as the key event of pancreatitis), and explore its mechanism, time course, and downstream consequences during pancreatic injury. CP was induced in mice by repeated episodes of acute pancreatitis (AP) based on caerulein hyperstimulation. ER stress leads to activation of unfolded protein response components that were measured in CP and AP. We show sustained up-regulation of unfolded protein response components ATF4, CHOP, GRP78, and XBP1 in CP. Overexpression of GRP78 and ATF4 in human CP confirmed the experimental findings. We used novel trypsinogen-7 knock-out mice (T(-/-)), which lack intra-acinar trypsinogen activation, to clarify the relationship of ER stress to intra-acinar trypsinogen activation in pancreatic injury. Comparable activation of ER stress was seen in wild type and T(-/-) mice. Induction of ER stress occurred through pathologic calcium signaling very early in the course of pancreatic injury. Our results establish that ER stress is chronically activated in CP and is induced early in pancreatic injury through pathologic calcium signaling independent of trypsinogen activation. ER stress may be an important pathogenic mechanism in pancreatitis that needs to be explored in future studies.

RETRACTED ARTICLE: Reanalysis of the gene expression profile in chronic pancreatitis via bioinformatics methods

BackgroundDiagnosis at an early stage of chronic pancreatitis (CP) is challenging. It has been reported that microRNAs (miRNAs) are increasingly found and applied as targets for the diagnosis and treatment of various cancers. However, to the best of our knowledge, few published papers have described the role of miRNAs in the diagnosis of CP.MethodWe downloaded gene expression profile data from the Gene Expression Omnibus and identified differentially expressed genes (DEGs) between CP and normal samples of Harlan mice and Jackson Laboratory mice. Common DEGs were filtered out, and the semantic similarities of gene classes were calculated using the GOSemSim software package. The gene class with the highest functional consistency was selected, and then the Lists2Networks web-based system was used to analyse regulatory relationships between miRNAs and gene classes. The functional enrichment of the gene classes was assessed based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway annotation terms.ResultsA total of 405 common upregulated DEGs and 7 common downregulated DEGs were extracted from the two kinds of mice. Gene cluster D was selected from the common upregulated DEGs because it had the highest semantic similarity. miRNA 124a (miR-124a) was found to have a significant regulatory relationship with cluster D, and DEGs such as CHSY1 and ABCC4 were found to be regulated by miR-124a. The GO term of response to DNA damage stimulus and the pathway of Escherichia coli infection were significantly enriched in cluster D.ConclusionDNA damage and E. coli infection might play important roles in CP pathogenesis. In addition, miR-124a might be a potential target for the diagnosis and treatment of CP.

Su1904 Ethanol Feeding Causes Alterations in Disulfide Bonding in Pancreatic Carboxyl Ester Lipase

Background and aim: Alcohol has been associated with activation and survival of activated pancreatic stellate cells (PSC). The effect of ethanol is partly mediated by the generation of oxidative stress within the cells, but other factors are required to induce pancreatic fibrogenesis. Tobacco is recognized as an etiologic factor of chronic pancreatitis (CP) and it is related with fibrogenesis in other tissues such as heart, liver and kidney. However its effect on pancreatic fibrogenesis is still unknown. We hypothesized that tobacco in combination with alcohol stimulates pancreatic fibrogenesis by PSC activation through the generation of oxidative stress within the cells. Our aim was to evaluate the effect of tobacco alone and in combination with alcohol on the activation of PSC and production of extracellular matrix (ECM) proteins and the generation of oxidative stress within the cells. Methods: PSC were isolated from rat pancreas Sprague-Dawley and exposed to tobacco (cigarette smoke condensate) alone (0.01mg/ml) or in combination of increasing concentrations of ethanol (5 to 50mM). PSC activation (α-SMA expression) was measured in both early and primary cell culture by Western blot. Fibronectin-1 (FNT-1) was evaluated by western blot and immunochemistry. Collagen-I was measured by western blot and Masson trichrome. Oxidative stress was examined using 2'-7'-dichlorofluorescin diacetate (DCF-DA) and was detected by flow cytometry. Results are expressed as mean±SEM. Statistical analysis was carried out one-way ANOVA followed by Fisher's LSD post hoc test. Results: Tobacco alone (α-SMA 1.83±0.3; p=0.003 versus negative control) or in combination with 50 mM ethanol (α-SMA 1.53±0.2; p=0.04 versus negative control) induced PSC activation in early culture. Tobacco in combination with 50 mM ethanol increased the expression of collagen-I (3.9±1.2, p<0.001 versus negative control) and FNT-1 (3.6±0.3, p<0.001 versus negative control and ethanol alone). Tobacco also increased the expression of FNT-1 in combination of 10mM alcohol (2.23±0.1, p=0.007 versus negative control). Ethanol (50mM) alone (3.06±0.77, p=0.008 versus negative control) or in combination with tobacco (0.01mg/mL) (2.68±0.49 E50, p=0.027 versus negative control) increased the reactive oxygen species fluorescence emission. Conclusion: Tobacco alone or in combination with alcohol induces the activation of PSC. Tobacco associated with alcohol increases the expression of extracellular matrix proteins and is a potential inducer of oxidative stress. These results support for the first time the synergistic effect of alcohol and tobacco in the pathogenesis of chronic pancreatitis.

Su1903 MicroRNA-196a As a Prognostic Marker in Pancreatic Neuroendocrine Tumor

Background and aim: Alcohol has been associated with activation and survival of activated pancreatic stellate cells (PSC). The effect of ethanol is partly mediated by the generation of oxidative stress within the cells, but other factors are required to induce pancreatic fibrogenesis. Tobacco is recognized as an etiologic factor of chronic pancreatitis (CP) and it is related with fibrogenesis in other tissues such as heart, liver and kidney. However its effect on pancreatic fibrogenesis is still unknown. We hypothesized that tobacco in combination with alcohol stimulates pancreatic fibrogenesis by PSC activation through the generation of oxidative stress within the cells. Our aim was to evaluate the effect of tobacco alone and in combination with alcohol on the activation of PSC and production of extracellular matrix (ECM) proteins and the generation of oxidative stress within the cells. Methods: PSC were isolated from rat pancreas Sprague-Dawley and exposed to tobacco (cigarette smoke condensate) alone (0.01mg/ml) or in combination of increasing concentrations of ethanol (5 to 50mM). PSC activation (α-SMA expression) was measured in both early and primary cell culture by Western blot. Fibronectin-1 (FNT-1) was evaluated by western blot and immunochemistry. Collagen-I was measured by western blot and Masson trichrome. Oxidative stress was examined using 2'-7'-dichlorofluorescin diacetate (DCF-DA) and was detected by flow cytometry. Results are expressed as mean±SEM. Statistical analysis was carried out one-way ANOVA followed by Fisher's LSD post hoc test. Results: Tobacco alone (α-SMA 1.83±0.3; p=0.003 versus negative control) or in combination with 50 mM ethanol (α-SMA 1.53±0.2; p=0.04 versus negative control) induced PSC activation in early culture. Tobacco in combination with 50 mM ethanol increased the expression of collagen-I (3.9±1.2, p<0.001 versus negative control) and FNT-1 (3.6±0.3, p<0.001 versus negative control and ethanol alone). Tobacco also increased the expression of FNT-1 in combination of 10mM alcohol (2.23±0.1, p=0.007 versus negative control). Ethanol (50mM) alone (3.06±0.77, p=0.008 versus negative control) or in combination with tobacco (0.01mg/mL) (2.68±0.49 E50, p=0.027 versus negative control) increased the reactive oxygen species fluorescence emission. Conclusion: Tobacco alone or in combination with alcohol induces the activation of PSC. Tobacco associated with alcohol increases the expression of extracellular matrix proteins and is a potential inducer of oxidative stress. These results support for the first time the synergistic effect of alcohol and tobacco in the pathogenesis of chronic pancreatitis.

High-resolution magic angle spinning1H magnetic resonance spectroscopy detects choline as a biomarker in a swine obstructive chronic pancreatitis model at an early stage

Chronic pancreatitis (CP) is a progressive inflammatory and fibrotic disease of the pancreas which encompasses a variety of clinical syndromes ranging from mild to life-threatening complications. Metabolomics has increasingly been applied to identify biomarkers for disease diagnosis with particular interest in diseases at an early stage. In this study, we tested a swine obstructive CP model by subtotal ligation of the main pancreatic duct, and the metabolic profiles of the Bama miniature swine pancreas were investigated using high-resolution magic angle spinning proton magnetic resonance spectroscopy (HR MAS (1)H MRS) combined with principal components analysis (PCA). Increases in lactate and choline for mild CP and decreases in glycerophosphocholine, phosphocholine, betaine and glycine were observed from normal pancreas to mild, moderate and severe CP. PCA results showed visual separations among the groups. The increase of choline at an early stage of CP and the decrease of glycerophosphocholine, phosphocholine, betaine and glycine reveal the pathogenesis of CP at a molecular level. The MRS results presented here demonstrate the potential of metabolic profiles in discriminating a normal pancreas from different stages of CP, which may be used to achieve CP early diagnosis and timely intervention to prevent irreversible destruction of the pancreas.

Global role for CPA1 variants in the pathogenesis of chronic pancreatitis

Global role for CPA1 variants in the pathogenesis of chronic pancreatitis

A Conservative Assessment of the Major Genetic Causes of Idiopathic Chronic Pancreatitis: Data from a Comprehensive Analysis of PRSS1, SPINK1, CTRC and CFTR Genes in 253 Young French Patients

Idiopathic chronic pancreatitis (ICP) has traditionally been defined as chronic pancreatitis in the absence of any obvious precipitating factors (e.g. alcohol abuse) and family history of the disease. Studies over the past 15 years have revealed that ICP has a highly complex genetic architecture involving multiple gene loci. Here, we have attempted to provide a conservative assessment of the major genetic causes of ICP in a sample of 253 young French ICP patients. For the first time, conventional types of mutation (comprising coding sequence variants and variants at intron/exon boundaries) and gross genomic rearrangements were screened for in all four major pancreatitis genes, PRSS1, SPINK1, CTRC and CFTR. For the purposes of the study, synonymous, intronic and 5'- or 3'-untranslated region variants were excluded from the analysis except where there was persuasive evidence of functional consequences. The remaining sequence variants/genotypes were classified into causative, contributory or neutral categories by consideration of (i) their allele frequencies in patient and normal control populations, (ii) their presumed or experimentally confirmed functional effects, (iii) the relative importance of their associated genes in the pathogenesis of chronic pancreatitis and (iv) gene-gene interactions wherever applicable. Adoption of this strategy allowed us to assess the pathogenic relevance of specific variants/genotypes to their respective carriers to an unprecedented degree. The genetic cause of ICP could be assigned in 23.7% of individuals in the study group. A strong genetic susceptibility factor was also present in an additional 24.5% of cases. Taken together, up to 48.2% of the studied ICP patients were found to display evidence of a genetic basis for their pancreatitis. Whereas these particular proportions may not be extrapolable to all ICP patients, the approach employed should serve as a useful framework for acquiring a better understanding of the role of genetic factors in causing this oligogenic disease.

Differences in the Degree of Cerulein-Induced Chronic Pancreatitis in C57BL/6 Mouse Substrains Lead to New Insights in Identification of Potential Risk Factors in the Development of Chronic Pancreatitis

A frequently used experimental model of chronic pancreatitis (CP) recapitulating human disease is repeated injection of cerulein into mice. C57BL/6 is the most commonly used inbred mouse strain for biomedical research, but widespread demand has led to generation of several substrains with subtly different phenotypes. In this study, two common substrains, C57BL/6J and C57BL/6NHsd, exhibited different degrees of CP, with C57BL/6J being more susceptible to repetitive cerulein-induced CP as assessed by pancreatic atrophy, pancreatic morphological changes, and fibrosis. We hypothesized that the deficiency of nicotinamide nucleotide transhydrogenase (NNT) protein in C57BL/6J is responsible for the more severe C57BL/6J phenotype but the parameters of CP in NNT-expressing transgenic mice generated on a C57BL6/J background do not differ with those of wild-type C57BL/6J. The highly similar genetic backgrounds but different CP phenotypes of these two substrains presents a unique opportunity to discover genes important in pathogenesis of CP. We therefore performed whole mouse genome Affymetrix microarray analysis of pancreatic gene expression of C57BL/6J and C57BL/6NHsd before and after induction of CP. Genes with differentially regulated expression between the two substrains that might be candidates in CP progression included Mmp7, Pcolce2, Itih4, Wdfy1, and Vtn. We also identified several genes associated with development of CP in both substrains, including RIKEN cDNA 1810009J06 gene (trypsinogen 5), Ccl8, and Ccl6.

Transforming growth factor-α activates pancreatic stellate cells and may be involved in matrix metalloproteinase-1 upregulation

The role that transforming growth factor-α (TGF-α) has in chronic pancreatitis and pancreatic cancer has not been fully elucidated. We evaluated the effects of TGF-α on the human pancreatic stellate cell (PSC) line RLT-PSC and primary human PSCs, and the expression levels of TGF-α and metalloproteinase-1 (MMP-1) in human chronic pancreatitis and pancreatic cancer tissues. TGF-α stimulated the proliferation and migration of PSCs. Although the mRNA expression levels of tissue inhibitor of metalloproteinase-1 and α1(I) collagen were unchanged, the mRNA expression levels of MMP-1 increased concomitant with increases in MMP-1 protein levels and collagenase activity. TGF-α-stimulated migration of RLT-PSC cells was partially blocked by tissue inhibitor of metalloproteinase-1 protein and MMP-1 small interfering RNA. MMP-1 was also observed to stimulate the migration of PSCs. TGF-α-induced MMP-1 expression was completely blocked by gefitinib in PSCs. The Ras-ERK and PI3/Akt pathways appear to be involved in the activation of MMP-1 in PSCs. Immunohistochemical analyses showed that MMP-1 expression was significantly increased in the pancreatic interstitial tissues in case of chronic pancreatitis or pancreatic cancer compared with those in case of normal pancreas. In conclusion, TGF-α increased proliferation and migration of PSCs. TGF-α-induced migration of cells may be partly due to upregulation of MMP-1. TGF-α and MMP-1 upregulation may contribute to the pathogenesis of chronic pancreatitis and pancreatic cancer.

The role of the metabolic syndrome in the development of chronic pancreatitis

A bibliographical review deals with modern concepts of the pathogenesis of chronic pancreatitis combined with the metabolic syndrome whose knowledge and generalization is an indispensable component for etiopathogenetic treatment of this particular pathology.

Antioxidant Status and Oxidative Stress Markers in Pancreatic Cancer and Chronic Pancreatitis

Oxidative stress has been implicated in the pathogenesis of chronic pancreatitis (CP) and pancreatic cancer (PC). The study aim was to assess the oxidative stress markers and antioxidant defense system in patients with CP and those with PC. Activities of superoxide dismutase 1 (SOD1), catalase (CAT), glutathione peroxidase 1 (GPX1), glutathione reductase (GR), arylesterase (PON1-A) and lactonase (PON1-L) activities of paraoxonase 1 (PON1) and concentrations of reduced glutathione, conjugated dienes in low-density lipoprotein (CD/LDL) and oxidized LDL (ox-LDL/LDL) were assessed in 50 PC and 50 CP patients and 50 age and sex-matched controls. Comparison of PC and CP groups to controls found the following changes: glutathione peroxidase 1 (GPX1) (-20.2%, -25.5%; P < 0.001), glutathione reductase (GR) (-9.5%, -11.9%; P < 0.05), SOD1 (+22.9%; P < 0.01), CAT (-10.6%; P < 0.05), PON1-A (-34.3%, -16.0%; P < 0.001), PON1-L (-44.2%; -17.0%; P < 0.01), conjugated dienes in LDL (CD/LDL) (+20%, +33.3%; P < 0.05) and ox-LDL/LDL (+42.2%, +14.4%; P < 0.05). The patients with PC had changed activities and levels of SOD1 (+24.2%), CAT (-10.4); P < 0.01), PON1-A (-21.7%), PON1-L (-32.9%), and ox-LDL/LDL (+24.3%); (all P < 0.01) compared with the patients with CP. Reduced antioxidant defense system capacity and increased markers of oxidative stress were found in PC and CP. PON1-L and CAT activities, along with ox-LDL/LDL levels, were the independent factors differentiating the patients with PC from the patients with CP.