scholarly journals Bile acids induce calcium signals in mouse pancreatic acinar cells: implications for bile‐induced pancreatic pathology

2002 ◽  
Vol 540 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Svetlana Voronina ◽  
Rebecca Longbottom ◽  
Robert Sutton ◽  
Ole H. Petersen ◽  
Alexei Tepikin
2004 ◽  
Vol 280 (3) ◽  
pp. 1764-1770 ◽  
Author(s):  
Svetlana G. Voronina ◽  
Olexyi V. Gryshchenko ◽  
Oleg V. Gerasimenko ◽  
Anne K. Green ◽  
Ole H. Petersen ◽  
...  

2010 ◽  
Vol 138 (5) ◽  
pp. S-149
Author(s):  
Abrahim I. Orabi ◽  
Ahsan U. Shah ◽  
Zahir M. Mannan ◽  
Mahwish U. Ahmad ◽  
Xingtie Nie ◽  
...  

2020 ◽  
Author(s):  
Júlia Fanczal

Acute biliary pancreatitis poses a significant clinical challenge as currently no specific pharmaceutical treatment exists. Disturbed intracellular Ca2+ signalling caused by bile acids is a hallmark of the disease, which induces increased reactive oxygen species (ROS) production, mitochondrial damage, intra-acinar digestive enzyme activation and cell death. Because of this mechanism of action, prevention of toxic cellular Ca2+ overload is a promising therapeutic target. Transient receptor potential melastatin 2 (TRPM2) is a non-selective cation channel that has recently emerged as an important contributor to oxidative-stress-induced cellular Ca2+ overload across different diseases. However, the expression and possible functions of TRPM2 in the exocrine pancreas remain unknown. Here we found that TRPM2 is expressed in the plasma membrane of mouse pancreatic acinar, which can be activated by increased oxidative stress induced by H2O2 treatment. TRPM2 activity was found to contribute to bile acid-induced extracellular Ca2+ influx in acinar cells. The generation of intracellular ROS in response to bile acids was remarkably higher in pancreatic acinar cells. This activity promoted acinar cell necrosis in vitro independently from mitochondrial damage or mitochondrial fragmentation. In addition, bile-acid-induced experimental pancreatitis was less severe in TRPM2 knockout mice, whereas the lack of TRPM2 had no protective effect in cerulein-induced acute pancreatitis. Our results suggest that the inhibition of TRPM2 may be a potential treatment option for biliary pancreatitis.


2007 ◽  
Vol 292 (3) ◽  
pp. G875-G886 ◽  
Author(s):  
L. Fischer ◽  
A. S. Gukovskaya ◽  
J. M. Penninger ◽  
O. A. Mareninova ◽  
H. Friess ◽  
...  

Bile acids are known to induce Ca2+ signals in pancreatic acinar cells. We have recently shown that phosphatidylinositol 3-kinase (PI3K) regulates changes in free cytosolic Ca2+ concentration ([Ca2+]i) elicited by CCK by inhibiting sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA). The present study sought to determine whether PI3K regulates bile acid-induced [Ca2+]i responses. In pancreatic acinar cells, pharmacological inhibition of PI3K with LY-294002 or wortmannin inhibited [Ca2+]i responses to taurolithocholic acid 3-sulfate (TLC-S) and taurochenodeoxycholate (TCDC). Furthermore, genetic deletion of the PI3K γ-isoform also decreased [Ca2+]i responses to bile acids. Depletion of CCK-sensitive intracellular Ca2+ pools or application of caffeine inhibited bile acid-induced [Ca2+]i signals, indicating that bile acids release Ca2+ from agonist-sensitive endoplasmic reticulum (ER) stores via an inositol ( 1 , 4 , 5 )-trisphosphate-dependent mechanism. PI3K inhibitors increased the amount of Ca2+ in intracellular stores during the exposure of acinar cells to bile acids, suggesting that PI3K negatively regulates SERCA-dependent Ca2+ reloading into the ER. Bile acids inhibited Ca2+ reloading into ER in permeabilized acinar cells. This effect was augmented by phosphatidylinositol ( 3 , 4 , 5 )-trisphosphate (PIP3), suggesting that both bile acids and PI3K act synergistically to inhibit SERCA. Furthermore, inhibition of PI3K by LY-294002 completely inhibited trypsinogen activation caused by the bile acid TLC-S. Our results indicate that PI3K and its product, PIP3, facilitate bile acid-induced [Ca2+]i responses in pancreatic acinar cells through inhibition of SERCA-dependent Ca2+ reloading into the ER and that bile acid-induced trypsinogen activation is mediated by PI3K. The findings have important implications for the mechanism of acute pancreatitis since [Ca2+]i increases and trypsinogen activation mediate key pathological processes in this disorder.


2004 ◽  
Vol 279 (26) ◽  
pp. 27327-27338 ◽  
Author(s):  
Svetlana G. Voronina ◽  
Stephanie L. Barrow ◽  
Oleg V. Gerasimenko ◽  
Ole H. Petersen ◽  
Alexei V. Tepikin

Cell Calcium ◽  
2015 ◽  
Vol 58 (2) ◽  
pp. 160-170 ◽  
Author(s):  
Nikolett Geyer ◽  
Gyula Diszházi ◽  
László Csernoch ◽  
István Jóna ◽  
János Almássy

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