Presence of pancreatic alpha-amylase, trypsinogen, and lipase immunoreactivity in normal human pancreatic ducts

Pancreatic duct-like cell line derived from pig embryonic stem cells: expression of uroplakin genes in pig pancreatic tissue

The isolation of a cell line, PICM-31D, with phenotypic characteristics like pancreatic duct cells is described. The PICM-31D cell line was derived from the previously described pig embryonic stem cell-derived exocrine pancreatic cell line, PICM-31. The PICM-31D cell line was morphologically distinct from the parental cells in growing as a monolayer rather than self-assembling into multicellular acinar-like structures. The PICM-31D cells were propagated for over a year at split ratios of 1:3 to 1:10 at each passage without change in phenotype or growth rate. Electron microscopy showed the cells to be a polarized epithelium of cuboidal cells joined by tight junction-like adhesions at their apical/lateral aspect. The cells contained numerous mucus-like secretory vesicles under their apical cell membrane. Proteomic analysis of the PICM-31D's cellular proteins detected MUC1 and MUC4, consistent with mucus vesicle morphology. Gene expression analysis showed the cells expressed pancreatic ductal cell-related transcription factors such as GATA4, GATA6, HES1, HNF1A, HNF1B, ONECUT1 (HNF6), PDX1, and SOX9, but little or no pancreas progenitor cell markers such as PTF1A, NKX6-1, SOX2, or NGN3. Pancreas ductal cell-associated genes including CA2, CFTR, MUC1, MUC5B, MUC13, SHH, TFF1, KRT8, and KRT19 were expressed by the PICM-31D cells, but the exocrine pancreas marker genes, CPA1 and PLA2G1B, were not expressed by the cells. However, the exocrine marker, AMY2A, was still expressed by the cells. Surprisingly, uroplakin proteins were prominent in the PICM-31D cell proteome, particularly UPK1A. Annexin A1 and A2 proteins were also relatively abundant in the cells. The expression of the uroplakin and annexin genes was detected in the cells, although only UPK1B, UPK3B, ANXA2, and ANXA4 were detected in fetal pig pancreatic duct tissue. In conclusion, the PICM-31D cell line models the mucus-secreting ductal cells of the fetal pig pancreas.

Cannabinoid receptor 2 agonist attenuates pain related behavior in rats with chronic alcohol/high fat diet induced pancreatitis

Background

Chronic Pancreatitis (CP) is a complex and multifactorial syndrome. Many contributing factors result in development of dysfunctional pain in a significant number of patients. Drugs developed to treat a variety of pain states fall short of providing effective analgesia for patients with chronic pancreatitis, often providing minimal to partial pain relief over time with significant side effects. Recently, availability of selective pharmacological tools has enabled great advances in our knowledge of the role of the cannabinoid receptors in pathophysiology. In particular, cannabinoid receptor 2 (CB2) has emerged as an attractive target for management of chronic pain, as demonstrated in several studies with inflammatory and neuropathic preclinical pain models. In this study, the analgesic efficacy of a novel, highly selective CB2 receptor agonist, LY3038404 HCl, is investigated in a chronic pancreatitis pain model, induced with an alcohol/high fat (AHF) diet.

Results

Rats fed the AHF diet developed visceral pain-like behaviors detectable by week 3 and reached a maximum at week 5 that persists as long as the diet is maintained. Rats with AHF induced chronic pancreatitis were treated with LY3038404 HCl (10 mg/kg, orally, twice a day for 9 days). The treated animals demonstrated significantly alleviated pain related behaviors after 3 days of dosing, including increased paw withdrawal thresholds (PWT), prolonged abdominal withdrawal latencies (ABWL), and decreased nocifensive responses to noxious 44°C hotplate stimuli. Terminal histological analysis of pancreatic tissue sections from the AHF chronic pancreatitis animals demonstrated extensive injury, including a global pancreatic gland degeneration (cellular atrophy), vacuolization (fat deposition), and fibrosis. After the LY3038404 HCl treatment, pancreatic tissue was significantly protected from severe damage and fibrosis. LY3038404 HCl affected neither open field exploratory behaviors nor dark/light box preferences as measures of higher brain and motor functions.

Conclusion

LY3038404 HCl, a potent CB2 receptor agonist, possesses tissue protective and analgesic properties without effects on higher brain function. Thus, activation of CB2 receptors is suggested as a potential therapeutic target for visceral inflammation and pain management.

Spontaneous development of a pancreatic exocrine disease in CD28-deficient NOD mice

Autoimmune pancreatitis (AIP) is a heterogeneous autoimmune disease in humans characterized by a progressive lymphocytic and plasmacytic infiltrate in the exocrine pancreas. In this study, we report that regulatory T cell-deficient NOD.CD28KO mice spontaneously develop AIP that closely resembles the human disease. NOD mouse AIP was associated with severe periductal and parenchymal inflammation of the exocrine pancreas by CD4(+) T cells, CD8(+) T cells, and B cells. Spleen CD4(+) T cells were found to be both necessary and sufficient for the development of AIP. Autoantibodies and autoreactive T cells from affected mice recognized a approximately 50-kDa protein identified as pancreatic amylase. Importantly, administration of tolerogenic amylase-coupled fixed spleen cells significantly ameliorated disease severity, suggesting that this protein functions as a key autoantigen. The establishment and characterization of this spontaneous pancreatic amylase-specific AIP in regulatory T cell-deficient NOD.CD28KO mice provides an excellent model for the study of disease pathogenesis and development of new therapies for human autoimmune pancreatitis.

Proteins expressed by pancreatic duct cells and their relatives

Significant progress has been made in the characterization of the structure and function of pancreatic ductal cells. Our understanding at this point in time extends to knowledge of specific molecules that provide for the structural composition of the ductal cells, their interactions with the local environment, and the regulation of their growth and properties of differentiation. Knowledge of the molecular composition and structure of the secretory products of epithelial cells in the pancreas also has increased so that we now understand the individual contributions of several secretory products to the overall function of pancreatic juice. Further study of these parameters will give us important insight into the normal function of the ductal cells and into how these processes are altered during the development and progression of diseases of the pancreas such as pancreatitis and cancer.

Expression of pancreatic enzymes (alpha-amylase, trypsinogen, and lipase) during human liver development and maturation

BACKGROUND/AIMS

Although pancreatic enzymes have been found in hilar intrahepatic bile ducts in adult humans, their expression during human liver development is unclear. The aim of this study was to clarify the temporal expression of pancreatic enzymes at various stages of human liver development.

METHODS

We immunohistochemically investigated pancreatic alpha-amylase, trypsinogen, and lipase expression in fetal, neonatal, juvenile, and adult human livers.

RESULTS

In hilar duct development, alpha-amylase but not trypsinogen or lipase was expressed in the ductal plate. These three enzymes were expressed in biliary cells migrating into the mesenchyma, in immature ducts in fetal livers, and in maturing and mature ducts in postnatal livers. Their expression was weak and diffusely cytoplasmic in fetal livers, whereas in postnatal livers their expression was strong, granular, and located in the supranuclear cytoplasm. Expression was not found in developing peripheral ducts. These enzymes were expressed in immature hepatocytes (9-25 weeks' gestation) but disappeared thereafter. Enzyme expression was mild in fetal pancreata and strong in adult pancreata.

CONCLUSIONS

Pancreatic enzymes may be present in primitive hilar bile ducts and hepatocytes in fetal livers; hilar ducts, hepatocytes, and pancreas may have similar fetal enzymatic profiles. Intrahepatic hilar bile ducts, hepatocytes, and exocrine pancreas may have a common cell lineage.

Immunocytochemical localization of elastase 1 in human pancreas

By light and electron microscopic immunocytochemistry the distribution is described of human pancreatic elastase 1 (E1) during ontogenesis, in adults, in cases of acute and chronic pancreatitis, acute pancreatic ischaemia as well as pancreatic tumours. E1-positive cells were first detected in ductal sprouts in the 14th gestational week. Complete acini expressing E1 could be found from the 17th to the 20th week of gestation onwards. Scattered distinct E1-positive epithelia could be found in the ducts of fetal and adult pancreas. By immunoelectron microscopy, E1 was localized in rough endoplasmic reticulum, condensing vacuoles, zymogen granules of acinar epithelia and in acinar lumina. E1 appeared to be distributed homogeneously in zymogen granules. As specific markers of acinar cells, both monoclonal antibodies under study identified heterotopic pancreatic acini in peribiliar glands of the liver and also helped to visualize different damage patterns in pancreatitis. The acinar epithelia surrounding acute lipolytic necroses initially reacted more intensely with the E1-antibodies than undamaged pancreatic tissue. In acute ischaemia, acinar cells which are dissociated from intercalated ducts lost their immunocytochemical reactivity for E1. Pancreatic parenchyma involved in advanced acute pancreatitis as well as in chronic inflammation was detected only weakly by both E1-antibodies. However, atrophic lobules in post-inflammatory scars were stained more intensely by the E1-antibodies than normal parenchyma. Pancreatic tumours (adenomas, adenocarcinomas, solid-cystic tumours and islet cell tumours) were not labelled by these antibodies.