scholarly journals A novel protein kinase D inhibitor attenuates early events of experimental pancreatitis in isolated rat acini

2011 ◽  
Vol 300 (1) ◽  
pp. G120-G129 ◽  
Author(s):  
Edwin C. Thrower ◽  
Jingzhen Yuan ◽  
Ashar Usmani ◽  
Yannan Liu ◽  
Courtney Jones ◽  
...  
Keyword(s):  
Acute Pancreatitis ◽  
Protein Kinase ◽  
Cell Injury ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Protein Kinase D ◽  
Amylase Secretion ◽  
Zymogen Activation ◽  
Isolated Rat ◽  
Novel Protein

Novel protein kinase C isoforms (PKC δ and ε) mediate early events in acute pancreatitis. Protein kinase D (PKD/PKD1) is a convergent point of PKC δ and ε in the signaling pathways triggered through CCK or cholinergic receptors and has been shown to activate the transcription factor NF-κB in acute pancreatitis. For the present study we hypothesized that a newly developed PKD/PKD1 inhibitor, CRT0066101, would prevent the initial events leading to pancreatitis. We pretreated isolated rat pancreatic acinar cells with CRT0066101 and a commercially available inhibitor Gö6976 (10 μM). This was followed by stimulation for 60 min with high concentrations of cholecystokinin (CCK, 0.1 μM), carbachol (CCh, 1 mM), or bombesin (10 μM) to induce initial events of pancreatitis. PKD/PKD1 phosphorylation and activity were measured as well as zymogen activation, amylase secretion, cell injury and NF-κB activation. CRT0066101 dose dependently inhibited secretagogue-induced PKD/PKD1 activation and autophosphorylation at Ser-916 with an IC50 ∼3.75–5 μM but had no effect on PKC-dependent phosphorylation of the PKD/PKD1 activation loop (Ser-744/748). Furthermore, CRT0066101 reduced secretagogue-induced zymogen activation and amylase secretion. Gö6976 reduced zymogen activation but not amylase secretion. Neither inhibitor affected basal zymogen activation or secretion. CRT0066101 did not affect secretagogue-induced cell injury or changes in cell morphology, but it reduced NF-κB activation by 75% of maximal for CCK- and CCh-stimulated acinar cells. In conclusion, CRT0066101 is a potent and specific PKD family inhibitor. Furthermore, PKD/PKD1 is a potential mediator of zymogen activation, amylase secretion, and NF-κB activation induced by a range of secretagogues in pancreatic acinar cells.

S1817 Protein Kinase D Modulates Secretagogue-Induced Zymogen Activation and Amylase Secretion in Rat Pancreatic Acinar Cells

2009 ◽  
Vol 136 (5) ◽  
pp. A-276
Author(s):  
Edwin C. Thrower ◽  
Jingzhen Yuan ◽  
Courtney Jones ◽  
Ashar Usmani ◽  
Meghan K. Kelly ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Protein Kinase D ◽  
Amylase Secretion ◽  
Zymogen Activation

scholarly journals Absence of the neutrophil serine protease cathepsin G decreases neutrophil granulocyte infiltration but does not change the severity of acute pancreatitis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ali A. Aghdassi ◽  
Daniel S. John ◽  
Matthias Sendler ◽  
Christian Storck ◽  
Cindy van den Brandt ◽  
...  
Keyword(s):  
Acute Pancreatitis ◽  
Serine Protease ◽  
Acinar Cells ◽  
Neutrophil Infiltration ◽  
Cathepsin G ◽  
Pancreatic Acinar Cells ◽  
Neutrophil Granulocyte ◽  
Zymogen Activation ◽  
Trypsinogen Activation ◽  
Extracellular Matrix Components

AbstractAcute pancreatitis is characterized by an early intracellular protease activation and invasion of leukocytes into the pancreas. Cathepsins constitute a large group of lysosomal enzymes, that have been shown to modulate trypsinogen activation and neutrophil infiltration. Cathepsin G (CTSG) is a neutrophil serine protease of the chymotrypsin C family known to degrade extracellular matrix components and to have regulatory functions in inflammatory disorders. The aim of this study was to investigate the role of CTSG in pancreatitis. Isolated acinar cells were exposed to recombinant CTSG and supramaximal cholezystokinin stimulation. In CTSG−/− mice and corresponding controls acute experimental pancreatitis was induced by serial caerulein injections. Severity was assessed by histology, serum enzyme levels and zymogen activation. Neutrophil infiltration was quantified by chloro-acetate ersterase staining and myeloperoxidase measurement. CTSG was expessed in inflammatory cells but not in pancreatic acinar cells. CTSG had no effect on intra-acinar-cell trypsinogen activation. In CTSG−/− mice a transient decrease of neutrophil infiltration into the pancreas and lungs was found during acute pancreatitis while the disease severity remained largely unchanged. CTSG is involved in pancreatic neutrophil infiltration during pancreatitis, albeit to a lesser degree than the related neutrophil (PMN) elastase. Its absence therefore leaves pancreatitis severity essentially unaffected.

scholarly journals Free radicals and the pancreatic acinar cells: role in physiology and pathology

2005 ◽  
Vol 360 (1464) ◽  
pp. 2273-2284 ◽  
Author(s):  
M Chvanov ◽  
O.H Petersen ◽  
A Tepikin
Keyword(s):  
Nitric Oxide ◽  
Signal Transduction ◽  
Acute Pancreatitis ◽  
Vascular Endothelium ◽  
Cell Injury ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Nitrogen Species ◽  
Key Enzyme ◽  
Oxide Synthase

Reactive oxygen and nitrogen species (ROS and RNS) play an important role in signal transduction and cell injury processes. Nitric oxide synthase (NOS)—the key enzyme producing nitric oxide (NO)—is found in neuronal structures, vascular endothelium and, possibly, in acinar and ductal epithelial cells in the pancreas. NO is known to regulate cell homeostasis, and its effects on the acinar cells are reviewed here. ROS are implicated in the early events within the acinar cells, leading to the development of acute pancreatitis. The available data on ROS/RNS involvement in the apoptotic and necrotic death of pancreatic acinar cells will be discussed.

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.

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 Genetic inhibition of protein kinase Cε attenuates necrosis in experimental pancreatitis

2014 ◽  
Vol 307 (5) ◽  
pp. G550-G563 ◽  
Author(s):  
Yannan Liu ◽  
Jingzhen Yuan ◽  
Tanya Tan ◽  
Wenzhuo Jia ◽  
Aurelia Lugea ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Inflammatory Responses ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Caspase Activation ◽  
Zymogen Activation ◽  
Cytochrome C Release ◽  
Interacting Protein ◽  
Regulated Necrosis

Understanding the regulation of death pathways, necrosis and apoptosis, in pancreatitis is important for developing therapies directed to the molecular pathogenesis of the disease. Protein kinase Cε (PKCε) has been previously shown to regulate inflammatory responses and zymogen activation in pancreatitis. Furthermore, we demonstrated that ethanol specifically activated PKCε in pancreatic acinar cells and that PKCε mediated the sensitizing effects of ethanol on inflammatory response in pancreatitis. Here we investigated the role of PKCε in the regulation of death pathways in pancreatitis. We found that genetic deletion of PKCε resulted in decreased necrosis and severity in the in vivo cerulein-induced pancreatitis and that inhibition of PKCε protected the acinar cells from CCK-8 hyperstimulation-induced necrosis and ATP reduction. These findings were associated with upregulation of mitochondrial Bak and Bcl-2/Bcl-xL, proapoptotic and prosurvival members in the Bcl-2 family, respectively, as well as increased mitochondrial cytochrome c release, caspase activation, and apoptosis in pancreatitis in PKCε knockout mice. We further confirmed that cerulein pancreatitis induced a dramatic mitochondrial translocation of PKCε, suggesting that PKCε regulated necrosis in pancreatitis via mechanisms involving mitochondria. Finally, we showed that PKCε deletion downregulated inhibitors of apoptosis proteins, c-IAP2, survivin, and c-FLIPs while promoting cleavage/inactivation of receptor-interacting protein kinase (RIP). Taken together, our findings provide evidence that PKCε activation during pancreatitis promotes necrosis through mechanisms involving mitochondrial proapoptotic and prosurvival Bcl-2 family proteins and upregulation of nonmitochondrial pathways that inhibit caspase activation and RIP cleavage/inactivation. Thus PKCε is a potential target for prevention and/or treatment of acute pancreatitis.

W1821 Protein Kinase D Mediates Nf-κB Activation Induced By Cholecystokinin and Cholinergic Signaling in Pancreatic Acinar Cells

2008 ◽  
Vol 134 (4) ◽  
pp. A-722
Author(s):  
Jingzhen Yuan ◽  
Aurelia Lugea ◽  
Ling Zheng ◽  
Ilya Gukovsky ◽  
Mouad Edderkaoui ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Protein Kinase D ◽  
Cholinergic Signaling

scholarly journals The novel protein kinase C isoforms -δ and -ε modulate caerulein-induced zymogen activation in pancreatic acinar cells

2008 ◽  
Vol 294 (6) ◽  
pp. G1344-G1353 ◽  
Author(s):  
Edwin C. Thrower ◽  
Sara Osgood ◽  
Christine A. Shugrue ◽  
Thomas R. Kolodecik ◽  
Anamika M. Chaudhuri ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Cell Fractionation ◽  
Zymogen Activation ◽  
Cellular Models ◽  
Kinase C

Isoforms of protein kinase C (PKC) have been shown to modulate some cellular responses such as pathological secretion and generation of inflammatory mediators during acute pancreatitis (AP). We propose that PKC also participates in premature zymogen activation within the pancreatic acinar cell, a key event in the initiation of AP. This hypothesis was examined in in vivo and cellular models of caerulein-induced AP using PKC activators and inhibitors. Phorbol ester, 12- O-tetradecanoylphorbol-13-acetate (TPA, 200 nM), a known activator of PKC, enhanced zymogen activation at both 0.1 nM and 100 nM caerulein, concentrations which mimic physiological and supraphysiological effects of the hormone cholecystokinin, respectively, in preparations of pancreatic acinar cells. Isoform-specific PKC inhibitors for PKC-δ and PKC-ε reduced supraphysiological caerulein-induced zymogen activation. Using a cell-free reconstitution system, we showed that inhibition of PKC-δ and -ε, reduced zymogen activation in both zymogen granule-enriched and microsomal fractions. In dispersed acinar cells, 100 nM caerulein stimulation caused PKC-δ and -ε isoform translocation to microsomal membranes using cell fractionation and immunoblot analysis. PKC translocation was confirmed with in vivo studies and immunofluorescence microscopy in pancreatic tissues from rats treated with or without 100 nM caerulein. PKC-ε redistributed from an apical to a supranuclear region following caerulein administration. The signal for PKC-ε overlapped with granule membrane protein, GRAMP-92, an endosomal/lysosomal marker, in a supranuclear region where zymogen activation takes place. These results indicate that PKC-δ and -ε isoforms translocate to specific acinar cell compartments and modulate zymogen activation.

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