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Proceedings of the National Academy of... Jan 2010The question of whether dedicated progenitor cells exist in adult vertebrate pancreas remains controversial. Centroacinar cells and terminal duct (CA/TD) cells lie at...
The question of whether dedicated progenitor cells exist in adult vertebrate pancreas remains controversial. Centroacinar cells and terminal duct (CA/TD) cells lie at the junction between peripheral acinar cells and the adjacent ductal epithelium, and are frequently included among cell types proposed as candidate pancreatic progenitors. However these cells have not previously been isolated in a manner that allows formal assessment of their progenitor capacities. We have found that a subset of adult CA/TD cells are characterized by high levels of ALDH1 enzymatic activity, related to high-level expression of both Aldh1a1 and Aldh1a7. This allows their isolation by FACS using a fluorogenic ALDH1 substrate. FACS-isolated CA/TD cells are relatively depleted of transcripts associated with differentiated pancreatic cell types. In contrast, they are markedly enriched for transcripts encoding Sca1, Sdf1, c-Met, Nestin, and Sox9, markers previously associated with progenitor populations in embryonic pancreas and other tissues. FACS-sorted CA/TD cells are uniquely able to form self-renewing "pancreatospheres" in suspension culture, even when plated at clonal density. These spheres display a capacity for spontaneous endocrine and exocrine differentiation, as well as glucose-responsive insulin secretion. In addition, when injected into cultured embryonic dorsal pancreatic buds, these adult cells display a unique capacity to contribute to both the embryonic endocrine and exocrine lineages. Finally, these cells demonstrate dramatic expansion in the setting of chronic epithelial injury. These findings suggest that CA/TD cells are indeed capable of progenitor function and may contribute to the maintenance of tissue homeostasis in adult mouse pancreas.
Topics: Aldehyde Dehydrogenase; Aldehyde Dehydrogenase 1 Family; Animals; Biomarkers; Cell Lineage; Cell Separation; Epithelial Cells; Flow Cytometry; Fluorescent Dyes; Gene Expression; Humans; Isoenzymes; Mice; Pancreas; Retinal Dehydrogenase; Stem Cells
PubMed: 20018761
DOI: 10.1073/pnas.0912589107 -
The Journal of Biological Chemistry Jan 1990Pancreatic cholesterol esterase (CEase) regulates dietary cholesterol absorption and is activated in the presence of trihydroxy bile salts while remaining inactive...
Pancreatic cholesterol esterase (CEase) regulates dietary cholesterol absorption and is activated in the presence of trihydroxy bile salts while remaining inactive monohydroxy bile salts. CEase from rat pancreas has been purified by ammonium sulfate precipitation, hydroxylapatite chromatography, and gel filtration on Sephacryl S-200/S-300 columns connected in series, and its homogeneity and Mr (55,418 +/- 288) have been determined by sedimentation equilibrium centrifugation. The effects of tri-, di-, and monohydroxy bile salts on the conformation of the purified enzyme in buffer solution and in an in vitro assay system were studied by circular dichroism spectropolarimetry. The CD spectrum of the enzyme in solution shows a curve shape suggestive of an alpha-helicity, but low mean residue ellipticity (MRE) values may indicate an important beta-turn contribution. Sodium cholate, a trihydroxy bile salt, induces a decrease in the negative MRE values of the enzyme in solution at bile salt concentrations of 70-100 nM, with no further spectral changes at concentrations as high as 1 mM. Sodium cholate concentrations higher than 1 microM also induce an increase in the enzyme's negative MRE values under activity assay conditions, which reverts toward its original value once the reaction reaches equilibrium. These latter changes are interpreted as induced by substrate binding to the enzyme followed by partial substrate depletion after the reaction reaches equilibrium. Sodium deoxycholate, a dihydroxy bile salt, induces unstable transient increases and decreases in the MRE values of CEase in buffer solution and under activity assay conditions. These changes are bile salt concentration-dependent and may reflect self-association of the protein. Sodium taurolithocholate, a monohydroxy bile salt, does not affect the CD spectrum of CEase, and neither the di- or the monohydroxy bile salt activates the enzyme.
Topics: Animals; Carboxylic Ester Hydrolases; Cholic Acid; Cholic Acids; Chromatography; Circular Dichroism; Deoxycholic Acid; Electrophoresis, Polyacrylamide Gel; Enzyme Activation; Molecular Weight; Pancreas; Protein Conformation; Rats; Sterol Esterase; Ultracentrifugation
PubMed: 2294119
DOI: No ID Found -
Gut Mar 1998The mechanisms responsible for the initiation of alcoholic pancreatitis remain elusive. However, there is an increasing body of evidence that reactive oxygen species...
BACKGROUND
The mechanisms responsible for the initiation of alcoholic pancreatitis remain elusive. However, there is an increasing body of evidence that reactive oxygen species play a role in both acute and chronic pancreatitis. In the liver, cytochrome P4502E1 (CYP2E1, the inducible ethanol metabolising enzyme) is one of the proposed pathways by which ethanol induces oxidative stress.
AIMS
To determine whether CYP2E1 is present in the pancreas and, if so, whether it is inducible by chronic ethanol feeding.
METHODS
Eighteen male Sprague-Dawley rats were pair fed liquid diets with or without ethanol as 36% of energy for four weeks. CYP2E1 levels were determined by western blotting of microsomal protein from both pancreas and liver. Messenger RNA (mRNA) levels for CYP2E1 were quantified using dot blots of total pancreatic RNA.
RESULTS
CYP2E1 was found in the pancreas. Furthermore, the amount of CYP2E1 was greater in the pancreas of rats fed ethanol compared with controls (mean increase over controls 5.1-fold, 95% confidence intervals 2.4 to 7.7, p < 0.02). In the liver, induction by ethanol of CYP2E1 was similar (mean increase over controls 7.9-fold, 95% confidence intervals 5.2 to 10.6, p < 0.005). Pancreatic mRNA levels for CYP2E1 were similar in ethanol fed and control rats.
CONCLUSIONS
CYP2E1 is present in the rat pancreas and is inducible by chronic ethanol administration. Induction of pancreatic CYP2E1 is not regulated at the mRNA level. The metabolism of ethanol via CYP2E1 may contribute to oxidative stress in the pancreas during chronic ethanol consumption.
Topics: Animals; Autoradiography; Blotting, Northern; Blotting, Western; Cytochrome P-450 CYP2E1; Enzyme Activation; Ethanol; Liver; Male; Pancreas; RNA, Messenger; Rats; Rats, Sprague-Dawley
PubMed: 9577353
DOI: 10.1136/gut.42.3.426 -
British Journal of Pharmacology Oct 19771 Nicotinic acid and alloxanate inhibited water and electrolyte secretion in a dose-dependent fashion when added to the perfusate of the isolated saline-perfused...
1 Nicotinic acid and alloxanate inhibited water and electrolyte secretion in a dose-dependent fashion when added to the perfusate of the isolated saline-perfused pancreas of the cat stimulated by a supramaximal dose of secretin.2 There were no changes in the concentration of sodium or potassium secreted into the juice, but the anions exhibited changes which were related to flow rate. As the flow rate declined the chloride concentration increased with a reciprocal decrease in bicarbonate concentration.3 Nicotinic acid and alloxanate inhibited enzyme secretion stimulated by carbachol.4 Imidazole inhibited pancreatic electrolyte secretion, but stimulated amylase secretion. Atropine (0.14 muM) reduced the secretion of amylase but did not abolish the effect.5 Adenylate cyclase prepared from cat pancreas, was stimulated by the octapeptide of cholecystokinin-pancreozymin, secretin and sodium fluoride.6 Alloxanate strongly inhibited both basal and hormone-stimulated adenylate cyclase activity. Nicotinic acid and imidazole stimulated basal adenylate cyclase activity but had little effect on secretin-stimulated activity.7 Alloxanate, nicotinic acid and imidazole were all without effect on phosphodiesterase when tested in the presence of micromolar concentrations of adenosine 3',5'-monophosphate (cyclic AMP). At higher cyclic AMP concentrations (2 mM) alloxanate and nicotinic acid were without effect, whereas imidazole had a slight stimulatory effect at 10 mM which was more marked at 50 mM.8 Alloxanate (10 mM) strongly inhibited both basal and secretin-stimulated adenylate cyclase activity.9 It is concluded that the effects of nicotinic acid, alloxanate and imidazole on pancreatic secretion are not mediated entirely through their effects on the adenylate cyclase or phosphodiesterase enzyme systems.
Topics: 3',5'-Cyclic-AMP Phosphodiesterases; Adenylyl Cyclases; Alloxan; Animals; Cats; Female; Imidazoles; In Vitro Techniques; Male; Nicotinic Acids; Pancreas; Sodium Chloride
PubMed: 200297
DOI: 10.1111/j.1476-5381.1977.tb08411.x -
The Yale Journal of Biology and Medicine 1992This paper reviews the relationships between the effects of glucocorticoids on rat pancreatic acinar AR42J cell polyamine levels and cellular growth and differentiation.... (Review)
Review
This paper reviews the relationships between the effects of glucocorticoids on rat pancreatic acinar AR42J cell polyamine levels and cellular growth and differentiation. Glucocorticoids inhibit the growth of AR42J cells. Glucocorticoids either stimulate or inhibit the formation of polyamines in a variety of cell types. Cells require polyamines for normal growth. Therefore, we tested the hypothesis that polyamines mediate the effects of glucocorticoids on AR42J cells. First, to confirm that AR42J cells required polyamines for growth we examined the effects of inhibiting ornithine decarboxylase (ODC). ODC is the most important and generally rate-limiting enzyme in the synthesis of the polyamines. As expected, the ODC inhibitor difluoromethylornithine (DFMO) inhibited AR42J cell DNA synthesis, and the addition of exogenous putrescine reversed this effect. The levels of growth inhibition by glucocorticoids and DFMO treatment were similar. Second, we examined the effects of glucocorticoids on ODC. Surprisingly, glucocorticoids increased levels of AR42J cell ODC mRNA, ODC activity, and putrescine. Glucocorticoids increased these parameters over a similar time-course as they decreased DNA synthesis. Analog specificity studies indicated that a glucocorticoid receptor mediated both the growth inhibitory and ODC stimulatory effects. Dose-response studies indicated, however, that growth inhibition was more sensitive to dexamethasone (DEX) than were ODC levels. Therefore, polyamines do not account for the effects of glucocorticoids on AR42J cell growth. In these cells, glucocorticoids have opposite and independent effects on ODC and growth.
Topics: Animals; Cell Division; Dexamethasone; Ornithine Decarboxylase; Pancreas; Rats; Tumor Cells, Cultured
PubMed: 1340062
DOI: No ID Found -
Pancreas Jul 2019Pancreatic cancer (PC) and its treatments can result in pancreatic exocrine insufficiency that requires pancreatic enzyme replacement therapy (PERT). Appropriate PERT...
OBJECTIVES
Pancreatic cancer (PC) and its treatments can result in pancreatic exocrine insufficiency that requires pancreatic enzyme replacement therapy (PERT). Appropriate PERT usage is during meals and snacks. The aim was to determine the frequency of appropriate use of PERT and its impact on symptom alleviation in PC through a patient-reported outcomes online platform.
METHODS
Users in the Pancreatic Cancer Action Network's Patient Registry were prompted to answer a standalone questionnaire about their experience with PERT.
RESULTS
Two hundred sixty-two users completed the PERT questionnaire (January 2016-January 2018). Patients who reported taking PERT with meals had higher alleviation of symptoms compared with those taking PERT prior to or after meals. Specifically, "feeling of indigestion," "light-colored or orange stools," and "visible food particles in stool" were significantly decreased. Patients taking PERT with meals reported weight gain and less weight loss.
CONCLUSIONS
Of the 89% of PC patients prescribed PERT, 65% were prescribed PERT appropriately with all meals and snacks. Overall compliance with PERT administration guidelines was low (50% [105/208]). Improvement in symptoms significantly correlated with appropriate use of PERT. Increase in PC patient and provider education about appropriate PERT usage and administration is warranted.
Topics: Adult; Aged; Aged, 80 and over; Enzyme Replacement Therapy; Exocrine Pancreatic Insufficiency; Female; Humans; Male; Middle Aged; Pancreas; Pancreatic Neoplasms; Pancrelipase; Retrospective Studies; Surveys and Questionnaires; Treatment Outcome; Young Adult
PubMed: 31210656
DOI: 10.1097/MPA.0000000000001330 -
The Journal of Biological Chemistry Feb 1961
Topics: Enzyme Activation; Enzyme Activators; Enzymes; Pancreas; Serine
PubMed: 13783661
DOI: No ID Found -
Journal of Agricultural and Food... May 2011This study determined the in vitro inhibitory effects of cocoa extracts and procyanidins against pancreatic α-amylase (PA), pancreatic lipase (PL), and secreted...
This study determined the in vitro inhibitory effects of cocoa extracts and procyanidins against pancreatic α-amylase (PA), pancreatic lipase (PL), and secreted phospholipase A(2) (PLA(2)) and characterized the kinetics of such inhibition. Lavado, regular, and Dutch-processed cocoa extracts as well as cocoa procyanidins (degree of polymerization (DP) = 2-10) were examined. Cocoa extracts and procyanidins dose-dependently inhibited PA, PL, and PLA(2). Lavado cocoa extract was the most potent inhibitor (IC(50) = 8.5-47 μg/mL). An inverse correlation between log IC(50) and DP (R(2) > 0.93) was observed. Kinetic analysis suggested that regular cocoa extract, the pentamer, and decamer inhibited PL activity in a mixed mode. The pentamer and decamer noncompetitively inhibited PLA(2) activity, whereas regular cocoa extract inhibited PLA(2) competitively. This study demonstrates that cocoa polyphenols can inhibit digestive enzymes in vitro and may, in conjunction with a low-calorie diet, play a role in body weight management.
Topics: Animals; Cacao; Enzyme Inhibitors; Lipase; Pancreas; Phospholipase A2 Inhibitors; Plant Extracts; Proanthocyanidins; alpha-Amylases
PubMed: 21495725
DOI: 10.1021/jf200180n -
World Journal of Gastroenterology Mar 2004To investigate effects of non-starch polysaccharides(NSP) enzymes on pancreatic and small intestinal digestive enzyme activities in piglet fed diets containing high...
AIM
To investigate effects of non-starch polysaccharides(NSP) enzymes on pancreatic and small intestinal digestive enzyme activities in piglet fed diets containing high amounts of barley.
METHODS
Sixty crossbred piglets averaging 13.5 kg were randomly assigned to two treatment groups with three replications (pens) based on sex and mass. Each group was fed on the diet based on barley with or without added NSP enzymes (0.15%) for a 40-d period. At the end of the experiment the pigs were weighed. Three piglets of each group were chosen and slaughtered. Pancreas, digesta from the distal end of the duodenum and jejunal mucosa were collected for determination. Activities of the digestive enzymes trypsin, chymotrypsin, amylase and lipase were determined in the small intestinal sections as well as in homogenates of pancreatic tissue. Maltase, sucrase, lactase and gamma-glutamyl transpeptidase (gamma-GT) activities were analyzed in jejunal mucosa.
RESULTS
Supplementation with NSP enzymes improved growth performance of piglets. It showed that NSP enzymes had no effect on digestive enzyme activities in pancreas, but decreased the activities of proteolytic enzyme, trypsin, amylase and lipase in duodenal contents by 57.56%, 76.08%, 69.03% and 40.22%(P<0.05) compared with control, and increased gamma-GT activities in jejunal mucosa by 118.75%(P<0.05).
CONCLUSION
Supplementation with NSP enzymes in barley based diets could improve piglets' growth performance, decrease activities of proteolytic enzyme, trypsin, amylase and lipase in duodenal contents and increase gamma-GT activities in jejunal mucosa.
Topics: Animals; Animals, Newborn; Diet; Digestion; Enzymes; Hordeum; Intestine, Small; Pancreas; Polysaccharides; Swine
PubMed: 15040032
DOI: 10.3748/wjg.v10.i6.856 -
Gut Mar 1997In human acute pancreatitis two different types of secretory phospholipase A2 (PLA2) have been found. (Comparative Study)
Comparative Study
BACKGROUND
In human acute pancreatitis two different types of secretory phospholipase A2 (PLA2) have been found.
AIM
To analyse the specific pattern of distribution of these PLA2 activities and their pathophysiological role in experimental acute pancreatitis.
SUBJECTS AND METHODS
Catalytic activities of secretory type I (pancreatic) and type II (non-pancreatic) PLA2 and the protein concentration of immunoreactive pancreatic PLA2 (IR-PLA2) in serum and pancreatic tissue of rats with cerulein (mild form) and sodium taurocholate (severe form) induced acute pancreatitis were determined.
RESULTS
Cerulein infusion caused a significant increase in type I PLA2 activity (p < 0.01) and IR-PLA2 protein concentration (p < 0.01) in serum and pancreas, whereas type II PLA2 activity remained unchanged during the 12 hour observation period. Histology showed no significant tissue destruction. In sodium taurocholate induced acute pancreatitis type II PLA2 activity significantly increased, reaching values over 10-fold higher than controls (p < 0.01), whereas IR-PLA2 protein concentration and type I PLA2 activity were only marginally increased. In this severe model of acute pancreatitis significantly lower values were detected than in the control pancreas (p < 0.002) for PLA2 activity and IR-PLA2 protein concentration. Histology showed parenchymal and fat necroses with haemorrhage, oedema, and inflammatory cell infiltration.
CONCLUSIONS
Type I PLA2 activity is dependent on the IR-PLA2 protein concentration in serum and pancreatic tissue. The type II PLA2 activity is not stimulated by cerulein, which indicates an extra-acinar origin of this enzyme. Type II PLA2 activity is significantly increased in sodium taurocholate induced acute pancreatitis indicating its role in the local necrotising process and involvement in the systemic effects in severe acute pancreatitis.
Topics: Acute Disease; Animals; Catalysis; Ceruletide; Female; Pancreas; Pancreatitis; Phospholipases A; Phospholipases A2; Rats; Rats, Wistar; Taurocholic Acid
PubMed: 9135530
DOI: 10.1136/gut.40.3.386