pH regulatory mechanisms in rat pancreatic ductal cells

The mechanisms underlying regulation of intracellular pH (pHi) by rat pancreatic duct cells were studied by use of the pH-sensitive, fluorescent, cytoplasmically trapped dye 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF). Cells exhibited a mean pHi of 7.18 +/- 0.14 in bicarbonate-buffered medium, as calculated from the BCECF fluorescence ratio. Removal of extracellular Na (Nao) caused an intracellular acidification that was rapidly reversed by Na replacement and occurred independently of Clo. Amiloride (10(-3) M) reversibly blocked Na-dependent recovery after Na-free-induced acidification. These results demonstrate the presence of a Na+-H+ exchange mechanism in pancreatic duct cells. Replacement of Clo with gluconate caused an intracellular alkalinization that was reversed by replacement of Cl. Application of the disulfonic stilbene derivatives, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) and dihydro-DIDS (2 X 10(-4) M), resulted in block of both Cl-dependent recovery from Na-gluconate and the onset of alkalinization of transition from NaCl to Na-gluconate. Chloride-dependent alteration of pHi occurred independently of Nao. These results demonstrate the presence of an anion exchange mechanism consistent with Cl--HCO3- exchange. Thus pancreatic duct cells contain both Na+-H+ and Cl--HCO3- exchangers.

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Anion selectivity and block of the small-conductance chloride channel on pancreatic duct cells

AJP Cell Physiology ◽

10.1152/ajpcell.1990.259.5.c752 ◽

1990 ◽

Vol 259 (5) ◽

pp. C752-C761 ◽

Cited By ~ 107

Author(s):

M. A. Gray ◽

C. E. Pollard ◽

A. Harris ◽

L. Coleman ◽

J. R. Greenwell ◽

...

Keyword(s):

Pancreatic Duct ◽

Plasma Membranes ◽

Duct Cell ◽

Disulfonic Acid ◽

Patch Clamp Technique ◽

Anion Selectivity ◽

Duct Cells ◽

Anion Permeation ◽

Pancreatic Duct Cells ◽

Small Conductance

Rat and human pancreatic duct cells have small-conductance Cl- channels in their apical plasma membranes. These channels are regulated by secretin and adenosine 3',5'-cyclic monophosphate and may function in parallel with Cl(-)-HCO3- exchangers to allow HCO3- secretion from the duct cell. Using the patch-clamp technique, we have now determined the anion permeability sequence of the channel as NO3- greater than Br- approximately I- approximately Cl- much greater than HCO3- much greater than gluconate. From this we conclude 1) that anion permeation involves a weak interaction with charged sites inside the channel pore, 2) that because of the low HCO3-/Cl- permeability ratio it is unlikely that significant amounts of HCO3- could be secreted directly via the channel, and 3) that channel permeability may determine the anion selectivity of secretion. We also show that 5-nitro-2-(3-phenylpropylamino)benzoic acid blocks the small-conductance Cl- channel, whereas 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid has no effect.

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cAMP-regulated whole cell chloride currents in pancreatic duct cells

AJP Cell Physiology ◽

10.1152/ajpcell.1993.264.3.c591 ◽

1993 ◽

Vol 264 (3) ◽

pp. C591-C602 ◽

Cited By ~ 94

Author(s):

M. A. Gray ◽

S. Plant ◽

B. E. Argent

Keyword(s):

Pancreatic Duct ◽

Single Cells ◽

Duct Cell ◽

Disulfonic Acid ◽

Apical Plasma Membrane ◽

Patch Clamp Technique ◽

Chloride Currents ◽

Whole Cell ◽

Duct Cells ◽

Pancreatic Duct Cells

Using the whole cell configuration of the patch-clamp technique, we have identified an adenosine 3',5'-cyclic monophosphate (cAMP)-regulated chloride conductance in pancreatic duct cells. Basal whole cell currents in single isolated cells were very low (approximately 5 pA/pF) but could be stimulated 17-fold by elevation of intracellular cAMP. The cAMP-activated currents exhibited 1) a high chloride selectivity, 2) a near linear current-voltage relationship, 3) time and voltage independence, 4) block by 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) but not by 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), and 5) an anion selectivity sequence based on permeability ratios of SCN > NO3 > Br > Cl > I > HCO3 > F > ClO4 > gluconate. Currents in single cells ran down within a few minutes; however, stable chloride currents could be recorded from duct cell clusters in which four or five cells were in electrical communication. We present evidence suggesting that these cAMP-regulated currents are carried by cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels. Physiologically, these CFTR channels act in parallel with chloride-bicarbonate exchangers to facilitate bicarbonate secretion across the apical plasma membrane of the duct cell.

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Kras and Lkb1 mutations synergistically induce intraductal papillary mucinous neoplasm derived from pancreatic duct cells

Gut ◽

10.1136/gutjnl-2018-318059 ◽

2019 ◽

Vol 69 (4) ◽

pp. 704-714 ◽

Cited By ~ 8

Author(s):

Louis Collet ◽

Elsa Ghurburrun ◽

Nora Meyers ◽

Mohamad Assi ◽

Boris Pirlot ◽

...

Keyword(s):

Pancreatic Duct ◽

Suppressor Gene ◽

Tumour Suppressor Gene ◽

Tumour Suppressor ◽

Pancreatic Ducts ◽

Ductal Cells ◽

Duct Cells ◽

Gastric Type ◽

Pancreatic Duct Cells ◽

Papillary Lesions

ObjectivePancreatic cancer can arise from precursor lesions called intraductal papillary mucinous neoplasms (IPMN), which are characterised by cysts containing papillae and mucus-producing cells. The high frequency of KRAS mutations in IPMN and histological analyses suggest that oncogenic KRAS drives IPMN development from pancreatic duct cells. However, induction of Kras mutation in ductal cells is not sufficient to generate IPMN, and formal proof of a ductal origin of IPMN is still missing. Here we explore whether combining oncogenic KrasG12D mutation with an additional gene mutation known to occur in human IPMN can induce IPMN from pancreatic duct cells.DesignWe created and phenotyped mouse models in which mutations in Kras and in the tumour suppressor gene liver kinase B1 (Lkb1/Stk11) are conditionally induced in pancreatic ducts using Cre-mediated gene recombination. We also tested the effect of β-catenin inhibition during formation of the lesions.ResultsActivating KrasG12D mutation and Lkb1 inactivation synergised to induce IPMN, mainly of gastric type and with malignant potential. The mouse lesions shared several features with human IPMN. Time course analysis suggested that IPMN developed from intraductal papillae and glandular neoplasms, which both derived from the epithelium lining large pancreatic ducts. β-catenin was required for the development of glandular neoplasms and subsequent development of the mucinous cells in IPMN. Instead, the lack of β-catenin did not impede formation of intraductal papillae and their progression to papillary lesions in IPMN.ConclusionOur work demonstrates that IPMN can result from synergy between KrasG12D mutation and inactivation of a tumour suppressor gene. The ductal epithelium can give rise to glandular neoplasms and papillary lesions, which probably both contribute to IPMN formation.

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Synergism between a dietary flavonoid and butyric acid derivative in correcting chloride secretory defect in cystic fibrosis pancreatic duct cells

Gastroenterology ◽

10.1016/s0016-5085(01)81676-0 ◽

2001 ◽

Vol 120 (5) ◽

pp. A337-A337

Author(s):

T NGUYEN ◽

S PERRINE ◽

U KIM

Keyword(s):

Cystic Fibrosis ◽

Pancreatic Duct ◽

Acid Derivative ◽

Butyric Acid ◽

Duct Cells ◽

Pancreatic Duct Cells ◽

Dietary Flavonoid

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Bile Acids Selectively Activate Iberiotoxin-sensitive Potassium Channels In Native Pancreatic Duct Cells

Biophysical Journal ◽

10.1016/j.bpj.2008.12.2769 ◽

2009 ◽

Vol 96 (3) ◽

pp. 536a-537a

Author(s):

Viktoria Venglovecz ◽

Peter Hegyi ◽

Zoltan Rakonczay ◽

Barry Argent ◽

Michael A. Gray

Keyword(s):

Potassium Channels ◽

Pancreatic Duct ◽

Bile Acids ◽

Duct Cells ◽

Pancreatic Duct Cells

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Recapitulation of embryonic neuroendocrine differentiation in adult human pancreatic duct cells expressing neurogenin 3

The Journal of Cell Biology ◽

10.1083/jcb.200203074 ◽

2002 ◽

Vol 159 (2) ◽

pp. 303-312 ◽

Cited By ~ 199

Author(s):

Yves Heremans ◽

Mark Van De Casteele ◽

Peter in't Veld ◽

Gerard Gradwohl ◽

Palle Serup ◽

...

Keyword(s):

Embryonic Development ◽

Pancreatic Duct ◽

Endocrine Pancreas ◽

Notch Pathway ◽

Neuroendocrine Differentiation ◽

Β Cell ◽

Neurogenin 3 ◽

Adult Human ◽

Duct Cells ◽

Pancreatic Duct Cells

Regulatory proteins have been identified in embryonic development of the endocrine pancreas. It is unknown whether these factors can also play a role in the formation of pancreatic endocrine cells from postnatal nonendocrine cells. The present study demonstrates that adult human pancreatic duct cells can be converted into insulin-expressing cells after ectopic, adenovirus-mediated expression of the class B basic helix-loop-helix factor neurogenin 3 (ngn3), which is a critical factor in embryogenesis of the mouse endocrine pancreas. Infection with adenovirus ngn3 (Adngn3) induced gene and/or protein expression of NeuroD/β2, Pax4, Nkx2.2, Pax6, and Nkx6.1, all known to be essential for β-cell differentiation in mouse embryos. Expression of ngn3 in adult human duct cells induced Notch ligands Dll1 and Dll4 and neuroendocrine- and β-cell–specific markers: it increased the percentage of synaptophysin- and insulin-positive cells 15-fold in ngn3-infected versus control cells. Infection with NeuroD/β2 (a downstream target of ngn3) induced similar effects. These data indicate that the Delta-Notch pathway, which controls embryonic development of the mouse endocrine pancreas, can also operate in adult human duct cells driving them to a neuroendocrine phenotype with the formation of insulin-expressing cells.

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