Secretin differentially sensitizes rat pancreatic acini to the effects of supramaximal stimulation with caerulein

2005 ◽  
Vol 289 (4) ◽  
pp. G713-G721 ◽  
Author(s):  
G. Perides ◽  
A. Sharma ◽  
A. Gopal ◽  
X. Tao ◽  
K. Dwyer ◽  
...  
Keyword(s):  
Acinar Cell ◽  
Cell Injury ◽  
Digestive Enzyme ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
High Dose ◽  
Zymogen Activation ◽  
Pancreatic Acini ◽  
Intracellular Ca ◽  
Supramaximal Stimulation

Supramaximal stimulation of the rat pancreas with CCK, or its analog caerulein, triggers acute pancreatitis and a number of pancreatitis-associated acinar cell changes including intracellular activation of digestive enzyme zymogens and acinar cell injury. It is generally believed that some of these various acinar cell responses to supramaximal secretagogue stimulation are interrelated and interdependent. In a recent report, Lu et al. ( 8 ) showed that secretin, by causing generation of cAMP and activation of PKA, sensitizes acinar cells to secretagogue-induced zymogen activation, and, as a result, submaximally stimulating concentrations of caerulein can, in the presence of secretin, trigger intracellular zymogen activation. We found that secretin also sensitizes acinar cells to secretagogue-induced cell injury and to subapical F-actin redistribution but that it did not alter the caerulein concentration dependence of other pancreatitis-associated changes such as the induction of a peak plateau intracellular [Ca2+] rise, inhibition of secretion, activation of ERK1/2, and activation of NF-κB. The finding that secretin sensitizes acinar cells to both intracellular zymogen activation and cell injury is consistent with the concept that these two early events in pancreatitis are closely interrelated and, possibly, interdependent. On the other hand, the finding that, in the presence of secretin, caerulein can trigger subapical F-actin redistribution without inhibiting secretion challenges the concept that disruption of the subapical F-actin web is causally related to high-dose secretagogue-induced inhibition of secretion in pancreatic acinar cells.

Substance P treatment stimulates chemokine synthesis in pancreatic acinar cells via the activation of NF-κB

2006 ◽  
Vol 291 (6) ◽  
pp. G1113-G1119 ◽  
Author(s):  
Raina Devi Ramnath ◽  
Madhav Bhatia
Keyword(s):  
Acute Pancreatitis ◽  
Substance P ◽  
Acinar Cell ◽  
Cell Injury ◽  
Acinar Cells ◽  
Pancreatic Acinar Cell ◽  
Pancreatic Acinar Cells ◽  
Chemokine Production ◽  
Pancreatic Acini ◽  
Monocyte Chemoattractant Protein 1

Acinar cell injury early in acute pancreatitis leads to a local inflammatory reaction and to the subsequent systemic inflammatory response, which may result in multiple organ dysfunction and death. Inflammatory mediators, including chemokines and substance P (SP), are known to play a crucial role in the pathogenesis of acute pancreatitis. It has been shown that pancreatic acinar cells produce the chemokine monocyte chemoattractant protein-1 (MCP-1) in response to caerulein hyperstimulation, demonstrating that acinar-derived MCP-1 is an early mediator of inflammation in acute pancreatitis. Similarly, SP levels in the pancreas and pancreatic acinar cell expression of neurokinin-1 receptor, the primary receptor for SP, are both increased during secretagogue-induced experimental pancreatitis. This study aims to examine the functional consequences of exposing mouse pancreatic acinar cells to SP and to determine whether it leads to proinflammatory signaling, such as production of chemokines. Exposure of mouse pancreatic acini to SP significantly increased synthesis of MCP-1, macrophage inflammatory protein-1α (MIP-1α), as well as MIP-2. Furthermore, SP also increased NF-κB activation. The stimulatory effect of SP was specific to chemokine synthesis through the NF-κB pathway, since the increase in chemokine production was completely attenuated when pancreatic acini were pretreated with the selective NF-κB inhibitor NF-κB essential modulator-binding domain peptide. This study shows that SP-induced chemokine synthesis in mouse pancreatic acinar cells is NF-κB dependent.

scholarly journals Alcohols enhance caerulein-induced zymogen activation in pancreatic acinar cells

2002 ◽  
Vol 282 (3) ◽  
pp. G501-G507 ◽  
Author(s):  
Zhao Lu ◽  
Suresh Karne ◽  
Thomas Kolodecik ◽  
Fred S. Gorelick
Keyword(s):  
Acinar Cell ◽  
Acinar Cells ◽  
Pancreatic Acinar Cell ◽  
Pancreatic Acinar Cells ◽  
Dependent Manner ◽  
Zymogen Activation ◽  
Concentration Dependent Manner ◽  
Pancreatic Acini ◽  
A Chain ◽  
Peak Value

Activation of zymogens within the pancreatic acinar cell is an early feature of acute pancreatitis. Supraphysiological concentrations of cholecystokinin (CCK) cause zymogen activation and pancreatitis. The effects of the CCK analog, caerulein, and alcohol on trypsin and chymotrypsin activation in isolated pancreatic acini were examined. Caerulein increased markers of zymogen activation in a time- and concentration-dependent manner. Notably, trypsin activity reached a peak value within 30 min, then diminished with time, whereas chymotrypsin activity increased with time. Ethanol (35 mM) sensitized the acinar cells to the effects of caerulein (10−10 to 10−7 M) on zymogen activation but had no effect alone. The effects of ethanol were concentration dependent. Alcohols with a chain length of ≥2 also sensitized the acinar cell to caerulein; the most potent was butanol. Branched alcohols (2-propanol and 2-butanol) were less potent than aliphatic alcohols (1-propanol and 1-butanol). The structure of an alcohol is related to its ability to sensitize acinar cells to the effects of caerulein on zymogen activation.

scholarly journals Cluster of Differentiation 38 (CD38) Mediates Bile Acid-induced Acinar Cell Injury and Pancreatitis through Cyclic ADP-ribose and Intracellular Calcium Release

2013 ◽  
Vol 288 (38) ◽  
pp. 27128-27137 ◽  
Author(s):  
Abrahim I. Orabi ◽  
Kamaldeen A. Muili ◽  
Tanveer A. Javed ◽  
Shunqian Jin ◽  
Thottala Jayaraman ◽  
...  
Keyword(s):  
Bile Acid ◽  
Ryanodine Receptor ◽  
Acinar Cell ◽  
Calcium Release ◽  
Cell Injury ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Iodide Uptake ◽  
Cyclic Adp Ribose ◽  
Intracellular Ca

Aberrant Ca2+ signals within pancreatic acinar cells are an early and critical feature in acute pancreatitis, yet it is unclear how these signals are generated. An important mediator of the aberrant Ca2+ signals due to bile acid exposure is the intracellular Ca2+ channel ryanodine receptor. One putative activator of the ryanodine receptor is the nucleotide second messenger cyclic ADP-ribose (cADPR), which is generated by an ectoenzyme ADP-ribosyl cyclase, CD38. In this study, we examined the role of CD38 and cADPR in acinar cell Ca2+ signals and acinar injury due to bile acids using pharmacologic inhibitors of CD38 and cADPR as well as mice deficient in Cd38 (Cd38−/−). Cytosolic Ca2+ signals were imaged using live time-lapse confocal microscopy in freshly isolated mouse acinar cells during perifusion with the bile acid taurolithocholic acid 3-sulfate (TLCS; 500 μm). To focus on intracellular Ca2+ release and to specifically exclude Ca2+ influx, cells were perifused in Ca2+-free medium. Cell injury was assessed by lactate dehydrogenase leakage and propidium iodide uptake. Pretreatment with either nicotinamide (20 mm) or the cADPR antagonist 8-Br-cADPR (30 μm) abrogated TLCS-induced Ca2+ signals and cell injury. TLCS-induced Ca2+ release and cell injury were reduced by 30 and 95%, respectively, in Cd38-deficient acinar cells compared with wild-type cells (p < 0.05). Cd38-deficient mice were protected against a model of bile acid infusion pancreatitis. In summary, these data indicate that CD38-cADPR mediates bile acid-induced pancreatitis and acinar cell injury through aberrant intracellular Ca2+ signaling.

Secretagogue-induced digestive enzyme activation and cell injury in rat pancreatic acini

1999 ◽  
Vol 276 (4) ◽  
pp. G835-G842 ◽  
Author(s):  
A. K. Saluja ◽  
L. Bhagat ◽  
H. S. Lee ◽  
M. Bhatia ◽  
J. L. Frossard ◽  
...  
Keyword(s):  
Acinar Cell ◽  
Cell Activation ◽  
Cell Injury ◽  
Digestive Enzyme ◽  
Enzyme Activation ◽  
Critical Event ◽  
Pancreatic Acini ◽  
Trypsinogen Activation ◽  
Intracellular Ca

The mechanisms responsible for intrapancreatic digestive enzyme activation as well as the relationship between that activation and cell injury during pancreatitis are not understood. We have employed an in vitro system in which freshly prepared pancreatic acini are exposed to a supramaximally stimulating concentration of the CCK analog caerulein to explore these issues. We find that in vitro trypsinogen activation depends on the continued presence of Ca2+in the suspending medium and that it is half-maximal in the presence of 0.3 mM Ca2+. Caerulein-induced trypsinogen activation can be halted by removal of Ca2+from the suspending medium or by chelation of intracellular Ca2+. Increasing intracellular Ca2+with either ionomycin or thapsigargin does not induce trypsinogen activation. We have monitored cell injury by measuring the leakage of lactate dehydrogenase (LDH) from acini and by quantitating intercalation of propidium iodide (PI) into DNA. Leakage of LDH and intercalation of PI in response to supramaximal stimulation with caerulein can be detected only after caerulein-induced trypsinogen activation has already occurred, and these indications of cell injury can be prevented by addition of a cell-permeant protease inhibitor. Our findings indicate that caerulein-induced intra-acinar cell activation of trypsinogen depends on a rise in intracellular Ca2+, which reflects entry of Ca2+from the suspending medium. Intra-acinar cell activation of trypsinogen is an early as well as a critical event in pancreatitis. The subsequent cell injury in this model is mediated by activated proteases.

Ethanol sensitizes NF-κB activation in pancreatic acinar cells through effects on protein kinase C-ε

2006 ◽  
Vol 291 (3) ◽  
pp. G432-G438 ◽  
Author(s):  
Akihiko Satoh ◽  
Anna S. Gukovskaya ◽  
Joseph R. Reeve ◽  
Tooru Shimosegawa ◽  
Stephen J. Pandol
Keyword(s):  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
High Dose ◽  
Pancreatic Acini ◽  
Kinase C ◽  
Pkc Isoforms ◽  
Ethanol Abuse ◽  
Pkc Ζ ◽  
Sensitizing Effect

Although ethanol abuse is the most common cause of pancreatitis, the mechanism of alcohol's effect on the pancreas is not well understood. Previously, we demonstrated that in vitro ethanol treatment of pancreatic acinar cells augmented the CCK-8-induced activation of NF-κB, a key signaling system involved in the inflammatory response of pancreatitis. In the present study, we determine the role for individual PKC isoforms in the sensitizing effect of ethanol on NF-κB activation. Dispersed rat pancreatic acini were treated with and without ethanol and then stimulated with CCK-8; 100 nM CCK-8 caused both NF-κB and PKC-δ, -ε, and -ζ activation, whereas 0.1 nM CCK-8 did not increase PKC-ε, PKC-ζ, or NF-κB activity. CCK-8 (0.1 nM) did activate PKC-δ. PKC-ε activator alone did not cause NF-κB activation; however, together with 0.1 nM CCK-8, it caused NF-κB activation. Ethanol activated PKC-ε without affecting other PKC isoforms or NF-κB activity. Of note, stimulation of acini with ethanol and 0.1 nM CCK-8 resulted in the activation of PKC-δ, PKC-ε, and NF-κB. The NF-κB activation to 0.1 nM CCK-8 in ethanol-pretreated acini was inhibited by both PKC-δ inhibitor and PKC-ε inhibitor. Taken together, these results demonstrate the different modes of activation of PKC isoforms and NF-κB in acini stimulated with ethanol, high-dose CCK-8, and low-dose CCK-8, and furthermore suggest that activation of both PKC-ε and -δ is required for NF-κB activation. These results suggest that ethanol enhances the CCK-8-induced NF-κB activation at least in part through its effects on PKC-ε.

Crambene induces pancreatic acinar cell apoptosis via the activation of mitochondrial pathway

2006 ◽  
Vol 291 (1) ◽  
pp. G95-G101 ◽  
Author(s):  
Yang Cao ◽  
Sharmila Adhikari ◽  
Abel Damien Ang ◽  
Marie Véronique Clément ◽  
Matthew Wallig ◽  
...  
Keyword(s):  
Acinar Cell ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Fas Ligand ◽  
Annexin V ◽  
Acinar Cells ◽  
Mitochondrial Pathway ◽  
Pancreatic Acinar Cell ◽  
Pancreatic Acinar Cells ◽  
Pancreatic Acini

We investigated the apoptotic pathway activated by crambene (1-cyano-2-hydroxy-3-butene), a plant nitrile, on pancreatic acinar cells. As evidenced by annexin V-FITC staining, crambene treatment for 3 h induced the apoptosis but not necrosis of pancreatic acini. Caspase-3, -8, and -9 activities in acini treated with crambene were significantly higher than in untreated acini. Treatment with caspase-3, -8, and -9 inhibitors inhibited annexin V staining, as well as caspase-3 activity, pointing to an important role of these caspases in crambene-induced acinar cell apoptosis. The mitochondrial membrane potential was collapsed, and cytochrome c was released from the mitochondria in crambene-treated acini. Neither TNF-α nor Fas ligand levels were changed in pancreatic acinar cells after crambene treatment. These results provide evidence for the induction of pancreatic acinar cell apoptosis in vitro by crambene and suggest the involvement of mitochondrial pathway in pancreatic acinar cell apoptosis.

Multiple isoforms of the ryanodine receptor are expressed in rat pancreatic acinar cells

2000 ◽  
Vol 351 (1) ◽  
pp. 265-271 ◽  
Author(s):  
Timothy J. FITZSIMMONS ◽  
Ilya GUKOVSKY ◽  
James A. McROBERTS ◽  
Edward RODRIGUEZ ◽  
F. Anthony LAI ◽  
...  
Keyword(s):  
Western Blot ◽  
Ryanodine Receptor ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Protein Band ◽  
Pancreatic Acinar Cell ◽  
Pancreatic Acinar Cells ◽  
Rt Pcr ◽  
Pancreatic Acini ◽  
Cell Functions

Regulation of cytosolic Ca2+ is important for a variety of cell functions. The ryanodine receptor (RyR) is a Ca2+ channel that conducts Ca2+ from internal pools to the cytoplasm. To demonstrate the presence of the RyR in the pancreatic acinar cell, we performed reverse transcriptase (RT)-PCR, Western blot, immunocytochemistry and microscopic Ca2+-release measurements on these cells. RT-PCR showed the presence of mRNA for RyR isoforms 1, 2 and 3 in both rat pancreas and dispersed pancreatic acini. Furthermore, mRNA expression for RyR isoforms 1 and 2 was demonstrated by RT-PCR in individual pancreatic acinar cells selected under the microscope. Western-blot analysis of acinar cell immunoprecipitates, using antibodies against RyR1 and RyR2, showed a high-molecular-mass (> 250kDa) protein band that was much less intense when immunoprecipitated in the presence of RyR peptide. Functionally, permeablized acinar cells stimulated with the RyR activator, palmitoyl-CoA, released Ca2+ from both basolateral and apical regions. These data show that pancreatic acinar cells express multiple isoforms of the RyR and that there are functional receptors throughout the cell.

scholarly journals Identification and localization of cholecystokinin-binding sites on rat pancreatic plasma membranes and acinar cells: a biochemical and autoradiographic study.

1983 ◽  
Vol 96 (5) ◽  
pp. 1288-1297 ◽  
Author(s):  
S A Rosenzweig ◽  
L J Miller ◽  
J D Jamieson
Keyword(s):  
Acinar Cell ◽  
Binding Sites ◽  
Plasma Membranes ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Cross Linking ◽  
Dependent Manner ◽  
Electron Microscopic ◽  
Electron Microscopic Autoradiography ◽  
Pancreatic Acini

Using the combined approaches of affinity labeling and light and electron microscopic autoradiography, we investigated the identification and localization of cholecystokinin (CCK)-binding sites on rat pancreatic acinar cells. To define the molecular properties of the CCK-binding site, we incubated rat pancreatic plasma membranes with 125-I-CCK-33 for 15 min at 23 degrees C followed by washing and cross-linking with disuccinimidyl suberate. Specific labeling of a major Mr 85,000 component was revealed as assessed by SDS PAGE under reducing conditions and autoradiography of the dried gels. Components of Mr greater than 200,000, Mr 130,000-140,000, and, Mr 55,000 were labeled under maximal cross-linking conditions. The labeling of all components was specifically inhibited by CCK-8 in a dose-dependent manner (Kd approximately 9 nM). The Mr 85,000 component had identical electrophoretic mobilities under reducing and nonreducing conditions indicating that it likely does not contain intramolecular disulfide bonds. The larger labeled species may be cross-linked oligomers of this binding protein or complexes between it and neighboring polypeptides. For studies on the distribution of CCK-binding sites, pancreatic acini were incubated with 125I-CCK-33 (0.1 nM) in the absence or presence of CCK-8 (1 microM) for 2 or 15 min at 37 degrees C, washed, and fixed in 2% glutaraldehyde. Quantitative autoradiographic analysis indicated that approximately 60% of the total grains were located within +/- 1 HD (1 HD = 100 nm) of the lateral and basal plasmalemma with little or no labeling of the apical plasmalemma. From these data, it was estimated that each acinar cell possesses at least 5,000-10,000 CCK-binding sites on its basolateral plasmalemma. The remaining grains showed no preferential concentration over the cytoplasm or nucleus. Together, these data indicate that CCK interacts with a Mr 85,000 protein located on the basolateral plasmalemma of the pancreatic acinar cell.

Spatiotemporal analysis of exocytosis in mouse parotid acinar cells

2005 ◽  
Vol 289 (5) ◽  
pp. C1209-C1219 ◽  
Author(s):  
Ying Chen ◽  
Jennifer D. Warner ◽  
David I. Yule ◽  
David R. Giovannucci
Keyword(s):  
Acinar Cell ◽  
Digestive Enzyme ◽  
Acinar Cells ◽  
Optical Measurements ◽  
Pancreatic Acinar Cells ◽  
Second Phase ◽  
Zymogen Granule ◽  
Exocrine Cells ◽  
Parotid Acinar Cells ◽  
Camp Elevation

Exocrine cells of the digestive system are specialized to secrete protein and fluid in response to neuronal and/or hormonal input. Although morphologically similar, parotid and pancreatic acinar cells exhibit important functional divergence in Ca2+ signaling properties. To address whether there are fundamental differences in exocytotic release of digestive enzyme from exocrine cells of salivary gland versus pancreas, we applied electrophysiological and optical methods to investigate spatial and temporal characteristics of zymogen-containing secretory granule fusion at the single-acinar cell level by direct or agonist-induced Ca2+ and cAMP elevation. Temporally resolved membrane capacitance measurements revealed that two apparent phases of exocytosis were induced by Ca2+ elevation: a rapidly activated initial phase that could not be resolved as individual fusion events and a second phase that was activated after a delay, increased in a staircaselike fashion, was augmented by cAMP elevation, and likely reflected both sequential compound and multivesicular fusion of zymogen-containing granules. Optical measurements of exocytosis with time-differential imaging analysis revealed that zymogen granule fusion was induced after a minimum delay of ∼200 ms, occurred initially at apical and basolateral borders of acinar cells, and under strong stimulation proceeded from apical pole to deeper regions of the cell interior. Zymogen granule fusions appeared to coordinate subsequent fusions and produced persistent structures that generally lasted several minutes. In addition, parotid gland slices were used to assess secretory dynamics in a more physiological context. Parotid acinar cells were shown to exhibit both similar and divergent properties compared with the better-studied pancreatic acinar cell regarding spatial organization and kinetics of exocytotic fusion of zymogen granules.

scholarly journals Pharmacological and genetic inhibition of calcineurin protects against carbachol-induced pathological zymogen activation and acinar cell injury

2012 ◽  
Vol 302 (8) ◽  
pp. G898-G905 ◽  
Author(s):  
Kamaldeen A. Muili ◽  
Mahwish Ahmad ◽  
Abrahim I. Orabi ◽  
Syeda M. Mahmood ◽  
Ahsan U. Shah ◽  
...  
Keyword(s):  
Acinar Cell ◽  
Cell Injury ◽  
Acinar Cells ◽  
High Amplitude ◽  
Pancreatic Acinar Cell ◽  
Critical Event ◽  
Amylase Secretion ◽  
Zymogen Activation ◽  
Inhibitory Peptide ◽  
A Subunit

Acute pancreatitis is a major health burden for which there are currently no targeted therapies. Premature activation of digestive proenzymes, or zymogens, within the pancreatic acinar cell is an early and critical event in this disease. A high-amplitude, sustained rise in acinar cell Ca2+ is required for zymogen activation. We previously showed in a cholecystokinin-induced pancreatitis model that a potential target of this aberrant Ca2+ signaling is the Ca2+-activated phosphatase calcineurin (Cn). However, in this study, we examined the role of Cn on both zymogen activation and injury, in the clinically relevant condition of neurogenic stimulation (by giving the acetylcholine analog carbachol) using three different Cn inhibitors or Cn-deficient acinar cells. In freshly isolated mouse acinar cells, pretreatment with FK506, calcineurin inhibitory peptide (CiP), or cyclosporine (CsA) blocked intra-acinar zymogen activation ( n = 3; P < 0.05). The Cn inhibitors also reduced leakage of lactate dehydrogenase (LDH) by 79%, 62%, and 63%, respectively ( n = 3; P < 0.05). Of the various Cn isoforms, the β-isoform of the catalytic A subunit (CnAβ) was strongly expressed in mouse acinar cells. For this reason, we obtained acinar cells from CnAβ-deficient mice (CnAβ−/−) and observed an 84% and 50% reduction in trypsin and chymotrypsin activation, respectively, compared with wild-type controls ( n = 3; P < 0.05). LDH release in the CnAβ-deficient cells was reduced by 50% ( n = 2; P < 0.05). The CnAβ-deficient cells were also protected against zymogen activation and cell injury induced by the cholecystokinin analog caerulein. Importantly, amylase secretion was generally not affected by either the Cn inhibitors or Cn deficiency. These data provide both pharmacological and genetic evidence that implicates Cn in intra-acinar zymogen activation and cell injury during pancreatitis.

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