Chronic pancreatitis

Adipose‑derived mesenchymal stem cells ameliorate dibutyltin dichloride‑induced chronic pancreatitis by inhibiting the PI3K/AKT/mTOR signaling pathway

Adipose-derived mesenchymal stem cells (ASCs) play a positive role in tissue injury repair and regeneration. The aim of this study was to determine whether ASCs could ameliorate chronic pancreatitis (CP) induced by the injection of dibutyltin dichloride (DBTC) and to elucidate its potential mechanisms. Furthermore, this study also explored whether there was a significant difference if the ASCs were injected via the inferior vena cava or the left gastric artery. CP was induced in rats by a single intravenous administration of DBTC, and the accumulation of collagen and apoptotic rates of pancreatic acinar cells were analyzed. According to the results, ASCs markedly reduced DBTC-induced pancreatic damage and collagen deposition in the rat model of CP. Moreover, ASCs significantly decreased pancreatic cell apoptosis by regulating the expression levels of caspase-3, BAX and Bcl-2. These effects were observed regardless of whether the injection was in the inferior vena cava or the left gastric artery. It was also found that the expression levels of phosphorylated PI3K, AKT and mTOR in pancreatic tissues of the DBTC-induced CP model group were significantly increased, while the expression levels of phosphorylated PI3K, AKT and mTOR in the two treatment groups were markedly decreased. ASCs noticeably suppressed the PI3K/AKT/mTOR pathway in the pancreatic tissue of DBTC-induced CP. This study indicated that ASCs protect against pancreatic fibrosis by modulating the PI3K/AKT/mTOR pathway, and have the potential to be a new strategy for the treatment of CP in the future.

Fully covered self-expanding metal stents for refractory pancreatic duct strictures in symptomatic chronic pancreatitis, US experience

Background and study aims  Fully covered self-expanding metal stents (FCSEMS) have been used to treat refractory pancreatic duct strictures. We aimed to evaluate the feasibility, safety, and efficacy of FCSEMS in chronic pancreatitis with refractory pancreatic duct strictures. Patients and methods  This was a retrospective multicenter cases series of patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) with FCSEMS placement in the main pancreatic duct (MPD) at five tertiary care centers between February 2010 and June 2016. Primary endpoints were technical success, clinical success, and procedure-related morbidity. Secondary endpoints were pain relief at the end of follow-up and resolution of the pancreatic stricture on ERCP. Results  Thirty-three patients with previously drained stents, 76 % of whom were male, underwent ERCP with FCSEMS placement. Mean duration of follow-up was 14 months. All of the patients had prior therapy. The technical success rate for FCSEMS placement was 100 % (n = 33) and the clinical success rate was 93 % (was n = 31). Stents were removed after a median duration of 14.4 weeks. After stent removal, the diameter of the narrowest MPD stricture had increased significantly from 1 mm to 4.5 mm ( P  < 0.001). There was a statistically significant improvement on the Visual Analogue Scale (VAS) from a median of 8.5 to 2.5. At the end of the study, (n = 27) 87.1 % of patients reported significant pain reduction with reduced narcotic use. Conclusion  FCSEMS appeared to be a feasible, safe, and potentially effective Intervention in patients who had not responded to endoscopic therapy with plastic stents.

Clube Português do Pâncreas Recommendations for Chronic Pancreatitis: Etiology, Natural History, and Diagnosis (Part I)

Chronic pancreatitis (CP) is a heterogeneous disease, with different causes and often a long delay between onset and full classic presentation. Clinical presentation depends on the stage of the disease. In earlier stages, recurrent episodes of acute pancreatitis are the major signs dominating clinical presentation. As the inflammatory process goes on, less acute episodes occur, and pain adopts different aspects or may even disappear. After 10-15 years from onset, functional insufficiency occurs. Then, a classic presentation with pain and pancreatic exocrine and endocrine insufficiency appears. Diagnosis remains challenging in the early stages of the disease, as its initial presentation is usually ill-defined and overlaps with other digestive disorders. Computed tomography and magnetic resonance cholangiopancreatography should be the first choice in patients with suspected CP. If the results are normal or equivocal but still there is a high suspicion of CP, the next option should be endoscopic ultrasound. Endoscopic retrograde cholangiopancreatography is mainly a therapeutic technique, and for the diagnostic purpose should only be used when all other imaging modalities and pancreatic function tests have been exhausted. Indirect tests are used to quantify the degree of insufficiency in already-established late CP. Recommendations on CP were developed by Clube Português do Pâncreas (CPP), based on literature review to answer predefined topics, subsequently discussed and approved by all members of CPP. Recommendations are separated in two parts: "chronic pancreatitis etiology, natural history, and diagnosis," and "chronic pancreatitis medical, endoscopic, and surgical treatment." This abstract pertains to part I.

Efficacy and safety of pancreatic enzyme replacement therapy on exocrine pancreatic insufficiency: a meta-analysis

BACKGROUND

Pancreatic enzyme replacement therapy (PERT) is widely applied to patients with exocrine pancreatic insufficiency (EPI), but its effect and safety has not been quantified. Therefore we performed a meta-analysis to determine the efficacy and tolerance of PERT on patients with EPI.

MATERIALS AND METHODS

PubMed, Medline, Cochrane library database, Evidence-based medicine/clinical trials published before December 2016 were searched by two independent reviewers to identify prospective randomized controlled trials (RCTs).

RESULTS

Seven RCTs, randomizing a total of 282 patients, were filtrated and assessed qualitatively (Jadad score). PERT increased CFA (WMD: 26.56, 20.35 to 32.76, I2= 79.6%, P < 0.001) compared with baseline, and CFA (WMD: 17.97, 12.61 to 23.34, I2 = 76.7%, P < 0.001) vs. placebo. Meanwhile, CNA, SFE, SNE and SW were significantly improved in PERT compared with baseline and placebo, with no statistical differences in adverse events. Subgroup analysis indicated that standard forms of PERT displayed more effectiveness with significantly decreased heterogeneity, and large sample size also reduced the heterogeneity to some degree.

CONCLUSIONS

PERT is demonstrated to be effective and tolerable in patients with EPI, especially using standard administration of PERT. Larger and higher quality studies on EPI are demanded to long-term effect of standard PERT treatment.

Chronic pancreatitis: Multicentre prospective data collection and analysis by the Hungarian Pancreatic Study Group

Introduction

Chronic pancreatitis is an inflammatory disease associated with structural and functional damage to the pancreas, causing pain, maldigestion and weight loss and thus worsening the quality of life.

Aims and methods

Our aim was to find correlations from a multicentre database representing the epidemiological traits, diagnosis and treatment of the disease in Hungary. The Hungarian Pancreatic Study Group collected data prospectively from 2012 to 2014 on patients suffering from chronic pancreatitis. Statistical analysis was performed on different questions.

Results

Data on 229 patients (74% male and 26% female) were uploaded from 14 centres. Daily alcohol consumption was present in the aetiology of 56% of the patients. 66% of the patients were previously treated for acute exacerbation. One third of the patients had had previous endoscopic or surgical interventions. Pain was present in 69% of the cases, endocrine insufficiency in 33%, diarrhoea in 13% and weight loss in 39%. Diagnosis was confirmed with US (80%), CT scan (52%), MRI-MRCP (6%), ERCP (39%), and EUS (7,4%). A functional test was carried out in 5% of the patients. In 31% of the cases, an endoscopic intervention was performed with the need for re-intervention in 5%. Further elective surgical intervention was necessitated in 44% of endoscopies. 20% of the registered patients were primarily treated with surgery. The biliary complication rate for surgery was significantly smaller (2%) than endoscopy (27%); however, pancreatic complications were higher in the patients treated with surgery. Patients who smoked regularly needed significantly more surgical intervention following endoscopy (66.7% vs. 26.9%, p = 0.002) than non-smokers, and the ratio of surgical intervention alone was also significantly higher (27.3% vs. 10.8%, p = 0.004). The ratio of surgery in patients who smoked and drank was significantly higher (30.09% vs. 12.5%, p = 0.012) than in abstinent and non-smoking patients, similarly to the need for further surgical intervention after endoscopic treatment (71.43% vs. 27.78%, p = 0.004).

Conclusions

According to the data analysed, the epidemiological data and the aetiological factors in our cohort differ little from European trends. The study highlighted the overuse of ERCP as a diagnostic modality and the low ratio of use of endoscopic ultrasonography. The results proved that alcohol consumption and smoking represent risk factors for the increased need for surgical intervention. Chronic pancreatitis should be treated by multidisciplinary consensus grounded in evidence-based medicine.

Pathologic Evaluation and Reporting of Intraductal Papillary Mucinous Neoplasms of the Pancreas and Other Tumoral Intraepithelial Neoplasms of Pancreatobiliary Tract: Recommendations of Verona Consensus Meeting

BACKGROUND

There are no established guidelines for pathologic diagnosis/reporting of intraductal papillary mucinous neoplasms (IPMNs).

DESIGN

An international multidisciplinary group, brought together by the Verona Pancreas Group in Italy-2013, was tasked to devise recommendations.

RESULTS

(1) Crucial to rule out invasive carcinoma with extensive (if not complete) sampling. (2) Invasive component is to be documented in a full synoptic report including its size, type, grade, and stage. (3) The term "minimally invasive" should be avoided; instead, invasion size with stage and substaging of T1 (1a, b, c; ≤ 0.5, > 0.5-≤ 1, > 1 cm) is to be documented. (4) Largest diameter of the invasion, not the distance from the nearest duct, is to be used. (5) A category of "indeterminate/(suspicious) for invasion" is acceptable for rare cases. (6) The term "malignant" IPMN should be avoided. (7) The highest grade of dysplasia in the non-invasive component is to be documented separately. (8) Lesion size is to be correlated with imaging findings in cysts with rupture. (9) The main duct diameter and, if possible, its involvement are to be documented; however, it is not required to provide main versus branch duct classification in the resected tumor. (10) Subtyping as gastric/intestinal/pancreatobiliary/oncocytic/mixed is of value. (11) Frozen section is to be performed highly selectively, with appreciation of its shortcomings. (12) These principles also apply to other similar tumoral intraepithelial neoplasms (mucinous cystic neoplasms, intra-ampullary, and intra-biliary/cholecystic).

CONCLUSIONS

These recommendations will ensure proper communication of salient tumor characteristics to the management teams, accurate comparison of data between analyses, and development of more effective management algorithms.

Total pancreatectomy with islet autotransplantation: summary of an NIDDK workshop

A workshop sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases focused on research gaps and opportunities in total pancreatectomy with islet autotransplantation (TPIAT) for the management of chronic pancreatitis. The session was held on July 23, 2014 and structured into 5 sessions: (1) patient selection, indications, and timing; (2) technical aspects of TPIAT; (3) improving success of islet autotransplantation; (4) improving outcomes after total pancreatectomy; and (5) registry considerations for TPIAT. The current state of knowledge was reviewed; knowledge gaps and research needs were specifically highlighted. Common themes included the need to identify which patients best benefit from and when to intervene with TPIAT, current limitations of the surgical procedure, diabetes remission and the potential for improvement, opportunities to better address pain remission, GI complications in this population, and unique features of children with chronic pancreatitis considered for TPIAT. The need for a multicenter patient registry that specifically addresses the complexities of chronic pancreatitis and total pancreatectomy outcomes and postsurgical diabetes outcomes was repeatedly emphasized.

Total pancreatectomy with islet autotransplantation: summary of a National Institute of Diabetes and Digestive and Kidney diseases workshop

A workshop sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases focused on research gaps and opportunities in total pancreatectomy with islet autotransplantation (TPIAT) for the management of chronic pancreatitis (CP). The session was held on July 23, 2014, and structured into 5 sessions: (1) patient selection, indications, and timing; (2) technical aspects of TPIAT; (3) improving success of islet autotransplantation; (4) improving outcomes after total pancreatectomy; and (5) registry considerations for TPIAT. The current state of knowledge was reviewed; knowledge gaps and research needs were specifically highlighted. Common themes included the need to identify which patients best benefit from and when to intervene with TPIAT, current limitations of the surgical procedure, diabetes remission and the potential for improvement, opportunities to better address pain remission, gastrointestinal complications in this population, and unique features of children with CP considered for TPIAT. The need for a multicenter patient registry that specifically addresses the complexities of CP and total pancreatectomy outcomes as well as postsurgical diabetes outcomes was repeatedly emphasized.

Pancreatic enzyme replacement therapy for pancreatic exocrine insufficiency in the 21st century

Restitution of normal fat absorption in exocrine pancreatic insufficiency remains an elusive goal. Although many patients achieve satisfactory clinical results with enzyme therapy, few experience normalization of fat absorption, and many, if not most, will require individualized therapy. Increasing the quantity of lipase administered rarely eliminates steatorrhea but increases the cost of therapy. Enteric coated enzyme microbead formulations tend to separate from nutrients in the stomach precluding coordinated emptying of enzymes and nutrients. Unprotected enzymes mix well and empty with nutrients but are inactivated at pH 4 or below. We describe approaches for improving the results of enzyme therapy including changing to, or adding, a different product, adding non-enteric coated enzymes, (e.g., giving unprotected enzymes at the start of the meal and acid-protected formulations later), use of antisecretory drugs and/or antacids, and changing the timing of enzyme administration. Because considerable lipid is emptied in the first postprandial hour, it is prudent to start therapy with enteric coated microbead prior to the meal so that some enzymes are available during that first hour. Patients with hyperacidity may benefit from adjuvant antisecretory therapy to reduce the duodenal acid load and possibly also sodium bicarbonate to prevent duodenal acidity. Comparative studies of clinical effectiveness of different formulations as well as the characteristics of dispersion, emptying, and dissolution of enteric-coated microspheres of different diameter and density are needed; many such studies have been completed but not yet made public. We discuss the history of pancreatic enzyme therapy and describe current use of modern preparations, approaches to overcoming unsatisfactory clinical responses, as well as studies needed to be able to provide reliably effective therapy.

Gene expression profiling and endothelin in acute experimental pancreatitis

AIM: To analyze gene expression profiles in an experimental pancreatitis and provide functional reversal of hypersensitivity with candidate gene endothelin-1 antagonists.

METHODS: Dibutyltin dichloride (DBTC) is a chemical used as a polyvinyl carbonate stabilizer/catalyzer, biocide in agriculture, antifouling agent in paint and fabric. DBTC induces an acute pancreatitis flare through generation of reactive oxygen species. Lewis-inbred rats received a single i.v. injection with either DBTC or vehicle. Spinal cord and dorsal root ganglia (DRG) were taken at the peak of inflammation and processed for transcriptional profiling with a cDNA microarray biased for rat brain-specific genes. In a second study, groups of animals with DBTC-induced pancreatitis were treated with endothelin (ET) receptor antagonists [ET-A (BQ123) and ET-B BQ788)]. Spontaneous pain related mechanical and thermal hypersensitivity were measured. Immunohistochemical analysis was performed using anti-ET-A and ET-B antibodies on sections from pancreatic tissues and DRG of the T10-12 spinal segments.

RESULTS: Animals developed acute pancreatic inflammation persisting 7-10 d as confirmed by pathological studies (edema in parenchyma, loss of pancreatic architecture and islets, infiltration of inflammatory cells, neutrophil and mononuclear cells, degeneration, vacuolization and necrosis of acinar cells) and the pain-related behaviors (cutaneous secondary mechanical and thermal hypersensitivity). Gene expression profile was different in the spinal cord from animals with pancreatitis compared to the vehicle control group. Over 260 up-regulated and 60 down-regulated unique genes could be classified into 8 functional gene families: circulatory/acute phase/immunomodulatory; extracellular matrix; structural; channel/receptor/transporter; signaling transduction; transcription/translation-related; antioxidants/chaperones/heat shock; pancreatic and other enzymes. ET-1 was among the 52 candidate genes up-regulated greater than 2-fold in animals with pancreatic inflammation and visceral pain-related behavior. Treatments with the ET-A (BQ123) and ET-B (BQ-788) antagonists revealed significant protection against inflammatory pain related mechanical and thermal hypersensitivity behaviors in animals with pancreatitis (P < 0.05). Open field spontaneous behavioral activity (at baseline, day 6 and 30 min after drug treatments (BQ123, BQ788) showed overall stable activity levels indicating that the drugs produced no undesirable effects on normal exploratory behaviors, except for a trend toward reduction of the active time and increase in resting time at the highest dose (300 μmol/L). Immunocytochemical localization revealed that expression of ET-A and ET-B receptors increased in DRG from animals with pancreatitis. Endothelin receptor localization was combined in dual staining with neuronal marker NeuN, and glia marker, glial fibrillary acidic protein. ET-A was expressed in the cell bodies and occasional nuclei of DRG neurons in naïve animals. However, phenotypic expression of ET-A receptor was greatly increased in neurons of all sizes in animals with pancreatitis. Similarly, ET-B receptor was localized in neurons and in the satellite glia, as well as in the Schwann cell glial myelin sheaths surrounding the axons passing through the DRG.

CONCLUSION: Endothelin-receptor antagonists protect against inflammatory pain responses without interfering with normal exploratory behaviors. Candidate genes can serve as future biomarkers for diagnosis and/or targeted gene therapy.

Current treatment options for chronic pancreatitis

Chronic pancreatitis (CP) is characterized by progressive and ultimately irreversible pancreatic injury. Alcohol abuse is the most common cause of CP in the Western world. As the pathophysiology of this disorder is better understood, it is probable that the treatment will be more successful. Therapeutic efforts for CP are focused on the treatment of maldigestion, pain, and diabetes. Dosage and timing of enteric-coated pancreatic enzymes are important issues in the treatment of malabsorption due to CP. Non-enteric-coated enzyme preparations along with acid suppression (histamine-2 blockers or proton-pump inhibitors) are of limited to modest effectiveness in treating pain caused by CP but are worth a trial in patients with less advanced disease. Extracorporeal shock wave lithotripsy (ESWL) of calcified stones is sometimes needed to achieve stone fragmentation before endoscopic removal. The role of ESWL alone in relieving calcified CP pain needs further study. Endoscopic therapy is aimed at decompressing the obstructed pancreatic duct and removal of pancreatic stone and is associated with pain relief in many patients. The role of endoscopic ultrasonography-guided celiac plexus block should be limited to treating those patients with CP whose pain has not responded to other modalities. Radiation therapy to the whole pancreas for CP pain relief is a revived treatment option that needs further study to confirm the safety and efficacy. Total pancreatectomy followed by autologous islet cell autotransplantation appears to be a potential therapeutic approach but should be considered as the last option in patients with refractory pain who have failed conventional medical, endoscopic, and surgical options.

A proposal for a new clinical classification of chronic pancreatitis

BACKGROUND

The clinical course of chronic pancreatitis is still unpredictable, which relates to the lack of the availability of a clinical classification. Therefore, patient populations cannot be compared, the course and the outcome of the disease remain undetermined in the individual patient, and treatment is not standardized.

AIM

To establish a clinical classification for chronic pancreatitis which is user friendly, transparent, relevant, prognosis- as well as treatment-related and offers a frame for future disease evaluation.

METHODS

Diagnostic requirements will include one clinical criterion, in combination with well defined imaging or functional abnormalities.

RESULTS

A classification system consisting of three stages (A, B and C) is presented, which fulfils the above-mentioned criteria. Clinical criteria are: pain, recurrent attacks of pancreatitis, complications of chronic pancreatitis (e.g. bile duct stenosis), steatorrhea, and diabetes mellitus. Imaging criteria consist of ductal or parenchymal changes observed by ultrasonography, ERCP, CT, MRI, and/or endosonography.

CONCLUSION

A new classification of chronic pancreatitis, based on combination of clinical signs, morphology and function, is presented. It is easy to handle and an instrument to study and to compare the natural course, the prognosis and treatment of patients with chronic pancreatitis.

Mechanisms of primary operative failure and results of remedial operation in patients with chronic pancreatitis

INTRODUCTION

Resection and drainage operations achieve long-term pain relief in approximately 85% of patients with chronic pancreatitis (CP). In patients who develop recurrent pain, a few data exist on the long-term results of remedial operations.

MATERIALS AND METHODS

Over an 18-year period (1988-2006), 316 patients with CP had primary resection or drainage operations at our institution. Thirty-nine developed recurrent pain and were treated by a remedial resection or drainage operation. Patient demographics, time to symptom recurrence, radiographic anatomic abnormalities, type of remedial operation, postoperative morbidity, and long-term outcomes were analyzed.

RESULTS

Thirty-nine patients, 56% female with a mean age of 41 years (range 16-61 years) had either remedial resection: total pancreatectomy (TP; N = 8), pancreaticoduodenectomy (PD; N = 6), distal pancreatectomy (DP; N = 5), or drainage operation: duodenal preserving pancreatic head resection (DPPHR; N = 8), revision of pancreaticojejunostomy (N = 12). TP achieved pain relief in 88% with postoperative complications greater than or equal to grade III in 38% and diabetes in 100%. Drainage operations achieved pain relief in 67% of patients with postoperative complications greater than or equal to grade III in only 8%. Partial parenchymal resections (DPPHR, PD, DP) as a remedial procedure achieved pain relief <50% of the time.

CONCLUSION

Drainage procedures, when anatomically feasible, are the preferred reoperation to treat patients with recurrent pain after failed primary operation for chronic pancreatitis.

Reduction of inflammation and chronic tissue damage by omega-3 fatty acids in fat-1 transgenic mice with pancreatitis

Pancreatitis is a severe debilitating disease with high morbidity and mortality. Treatment is mostly supportive, and until now there are no clinically useful strategies for anti-inflammatory therapy. Although omega-3 polyunsaturated fatty acids (n-3 PUFA) are known to have anti-inflammatory effects, the utility of these fatty acids in the alleviation of pancreatitis remained to be investigated. The aim of this study was to examine the effect of n-3 PUFA on both acute and chronic pancreatitis in a well-controlled experimental system. We used the fat-1 transgenic mouse model, characterized by endogenously increased tissue levels of n-3 PUFA, and their wild-type littermates to examine the effect of n-3 PUFA on both acute and chronic cerulein-induced pancreatitis. Disease activity and inflammatory status were assessed by both histology and molecular methods. In acute pancreatitis, fat-1 mice showed a trend towards decreased necrosis and significantly reduced levels of plasma IL-6 levels as well as reduced neutrophil infiltration in the lung. In chronic pancreatitis there was less pancreatic fibrosis and collagen content accompanied by decreased pancreatic stellate cell activation in the fat-1 animals with increased n-3 PUFA tissue levels as compared to wild-type littermates with high levels of omega-6 (n-6) PUFA in their tissues. Our data provide evidence for a reduction of systemic inflammation in acute pancreatitis and of tissue fibrosis in chronic pancreatitis by increasing the tissue content of omega-3 polyunsaturated fatty acids. These results suggest a beneficial potential for n-3 PUFA supplementation in acute and particularly chronic pancreatitis.

Critical roles for macrophages in islet angiogenesis and maintenance during pancreatic degeneration

OBJECTIVE

Chronic pancreatitis, characterized by pancreatic exocrine tissue destruction with initial maintenance of islets, eventually leads to insulin-dependent diabetes in most patients. Mice deficient for the transcription factors E2F1 and E2F2 suffer from a chronic pancreatitis-like syndrome and become diabetic. Surprisingly, onset of diabetes can be prevented through bone marrow transplantation. The goal of the described studies was to determine the hematopoietic cell type responsible for maintaining islets and the associated mechanism of this protection.

RESEARCH DESIGN AND METHODS

Mouse models of acute and chronic pancreatitis, together with mice genetically deficient for macrophage production, were used to determine roles for macrophages in islet angiogenesis and maintenance.

RESULTS

We demonstrate that macrophages are essential for preventing endocrine cell loss and diabetes. Macrophages expressing matrix metalloproteinase-9 migrate to the deteriorating pancreas. E2f1/E2f2 mutant mice transplanted with wild-type, but not macrophage-deficient colony stimulating factor 1 receptor mutant (Csf1r(-/-)), bone marrow exhibit increased angiogenesis and proliferation within islets, coinciding with increased islet mass. A similar macrophage dependency for islet and islet vasculature maintenance is observed during caerulein-induced pancreatitis.

CONCLUSIONS

These findings demonstrate that macrophages promote islet angiogenesis and protect against islet loss during exocrine degeneration, could explain why most patients with chronic pancreatitis develop diabetes, and suggest an avenue for preventing pancreatitis-associated diabetes.

Cannabinoids reduce markers of inflammation and fibrosis in pancreatic stellate cells

Background

While cannabinoids have been shown to ameliorate liver fibrosis, their effects in chronic pancreatitis and on pancreatic stellate cells (PSC) are unknown.

Methodology/Principal Findings

The activity of the endocannabinoid system was evaluated in human chronic pancreatitis (CP) tissues. In vitro, effects of blockade and activation of cannabinoid receptors on pancreatic stellate cells were characterized. In CP, cannabinoid receptors were detected predominantly in areas with inflammatory changes, stellate cells and nerves. Levels of endocannabinoids were decreased compared with normal pancreas. Cannabinoid-receptor-1 antagonism effectuated a small PSC phenotype and a trend toward increased invasiveness. Activation of cannabinoid receptors, however, induced de-activation of PSC and dose-dependently inhibited growth and decreased IL-6 and MCP-1 secretion as well as fibronectin, collagen1 and alphaSMA levels. De-activation of PSC was partially reversible using a combination of cannabinoid-receptor-1 and -2 antagonists. Concomitantly, cannabinoid receptor activation specifically decreased invasiveness of PSC, MMP-2 secretion and led to changes in PSC phenotype accompanied by a reduction of intracellular stress fibres.

Conclusions/Significance

Augmentation of the endocannabinoid system via exogenously administered cannabinoid receptor agonists specifically induces a functionally and metabolically quiescent pancreatic stellate cell phenotype and may thus constitute an option to treat inflammation and fibrosis in chronic pancreatitis.

Review of idiopathic pancreatitis

Recent advances in understanding of pancreatitis and advances in technology have uncovered the veils of idiopathic pancreatitis to a point where a thorough history and judicious use of diagnostic techniques elucidate the cause in over 80% of cases. This review examines the multitude of etiologies of what were once labeled idiopathic pancreatitis and provides the current evidence on each. This review begins with a background review of the current epidemiology of idiopathic pancreatitis prior to discussion of various etiologies. Etiologies of medications, infections, toxins, autoimmune disorders, vascular causes, and anatomic and functional causes are explored in detail. We conclude with management of true idiopathic pancreatitis and a summary of the various etiologic agents. Throughout this review, areas of controversies are highlighted.

The pancreatic stellate cell: a star on the rise in pancreatic diseases

Pancreatic stellate cells (PaSCs) are myofibroblast-like cells found in the areas of the pancreas that have exocrine function. PaSCs are regulated by autocrine and paracrine stimuli and share many features with their hepatic counterparts, studies of which have helped further our understanding of PaSC biology. Activation of PaSCs induces them to proliferate, to migrate to sites of tissue damage, to contract and possibly phagocytose, and to synthesize ECM components to promote tissue repair. Sustained activation of PaSCs has an increasingly appreciated role in the fibrosis that is associated with chronic pancreatitis and with pancreatic cancer. Therefore, understanding the biology of PaSCs offers potential therapeutic targets for the treatment and prevention of these diseases.