CCK independently activates intracellular trypsinogen and NF-κB in rat pancreatic acinar cells

2001 ◽  
Vol 280 (3) ◽  
pp. C465-C472 ◽  
Author(s):  
Bing Han ◽  
Baoan Ji ◽  
Craig D. Logsdon

In the cholecystokinin (CCK) hyperstimulation model of acute pancreatitis, two early intracellular events, activation of trypsinogen and activation of nuclear factor-κB (NF-κB), are thought to be important in the development of the disease. In this study, the relationship between these two events was investigated. NF-κB activity was monitored by using a DNA binding assay and mob-1 chemokine gene expression. Intracellular trypsin activity was measured by using a fluorogenic substrate. Protease inhibitors including FUT-175, Pefabloc, and E-64d prevented CCK stimulation of intracellular trypsinogen and NF-κB activation. Likewise, the NF-κB inhibitors pyrrolidine dithiocarbamate and N-acetyl-l-cysteine inhibited CCK stimulation of NF-κB and intracellular trypsinogen activation. These results suggested a possible codependency of these two events. However, CCK stimulated NF-κB activation in Chinese hamster ovary-CCKAcells, which do not express trypsinogen, indicating that trypsin is not necessary for CCK activation of NF-κB. Furthermore, adenovirus-mediated expression in acinar cells of active p65 subunits to stimulate NF-κB, or of inhibitory κB-α molecules to inhibit NF-κB, did not affect either basal or CCK-mediated trypsinogen activation. Thus trypsinogen and NF-κB activation are independent events stimulated by CCK.

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ali A. Aghdassi ◽  
Daniel S. John ◽  
Matthias Sendler ◽  
Christian Storck ◽  
Cindy van den Brandt ◽  
...  

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.


1994 ◽  
Vol 267 (2) ◽  
pp. C385-C393 ◽  
Author(s):  
H. Zhao ◽  
X. Xu ◽  
K. Ujiie ◽  
R. A. Star ◽  
S. Muallem

Recently, we showed that NO2- increases gap junction (GJ) permeability and synchronizes intracellular Ca2+ concentration oscillations in pancreatic acini (Loessburg et al., J. Biol. Chem. 268: 19769-19775, 1993). NO2- is also an end product of nitric oxide (NO) production and metabolism. Because of the effect of NO2- on GJ permeability and the possible importance of NO2- in NO metabolism and cytotoxicity, we used pancreatic acinar cells and intracellular pH (pHi) measurements to study the interaction of nitrogen oxides and NO2- with cellular proteins. Exposing cells to NO2- resulted in a concentration-dependent cytosolic acidification. The acidification did not require the transport of NO2- and was not mediated by diffusion of HNO2. Because the acidification was prevented by CO2-HCO3- and inhibition of carbonic anhydrase, it is possible that other nitrogen oxides present in a solution containing NO2- enter the cells by diffusion and interact with OH- or H2O to stably acidify the cytosol. NO2- itself is shown to be transported by the HCO3- transporters present in the plasma membrane. Thus manipulation of the cellular Cl- gradient and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) were used to show Cl-/NO2- exchange, whereas stimulation of external Na(+)-dependent amiloride-insensitive and DIDS-sensitive pHi increase in acidified cells was used to demonstrate a Na(+)-(NO2-)n cotransport. Hence NO2- can be a convenient substitute for HCO3- when studying HCO3- transport in an open system. The studies also show that cellular levels of nitrogen oxides and NO2- can be modulated by the cellular HCO3(-)-buffering system.(ABSTRACT TRUNCATED AT 250 WORDS)


1998 ◽  
Vol 275 (3) ◽  
pp. C810-C817 ◽  
Author(s):  
Antonio González ◽  
Fatima Pfeiffer ◽  
Andreas Schmid ◽  
Irene Schulz

We have used fluo 3-loaded mouse pancreatic acinar cells to investigate the relationship between Ca2+ mobilization and intracellular pH (pHi). The Ca2+-mobilizing agonist ACh (500 nM) induced a Ca2+ release in the luminal cell pole followed by spreading of the Ca2+ signal toward the basolateral side with a mean speed of 16.1 ± 0.3 μm/s. In the presence of an acidic pHi, achieved by blockade of the Na+/H+exchanger or by incubation of the cells in a Na+-free buffer, a slower spreading of ACh-evoked Ca2+ waves was observed (7.2 ± 0.6 μm/s and 7.5 ± 0.3 μm/s, respectively). The effects of cytosolic acidification on the propagation rate of ACh-evoked Ca2+ waves were largely reversible and were not dependent on the presence of extracellular Ca2+. A reduction in the spreading speed of Ca2+ waves could also be observed by inhibition of the vacuolar H+-ATPase with bafilomycin A1 (11.1 ± 0.6 μm/s), which did not lead to cytosolic acidification. In contrast, inhibition of the endoplasmic reticulum Ca2+-ATPase by 2,5-di- tert-butylhydroquinone led to faster spreading of the ACh-evoked Ca2+ signals (25.6 ± 1.8 μm/s), which was also reduced by cytosolic acidification or treatment of the cells with bafilomycin A1. Cytosolic alkalinization had no effect on the spreading speed of the Ca2+ signals. The data suggest that the propagation rate of ACh-induced Ca2+ waves is decreased by inhibition of Ca2+ release from intracellular stores due to cytosolic acidification or to Ca2+ pool alkalinization and/or to a decrease in the proton gradient directed from the inositol 1,4,5-trisphosphate-sensitive Ca2+ pool to the cytosol.


2019 ◽  
Vol 39 (7) ◽  
Author(s):  
Juan Xiao ◽  
Houmin Lin ◽  
Binggang Liu ◽  
Junfei Jin

Abstract Premature trypsinogen activation is the early event of acute pancreatitis. Therefore, the studies on the processes of trypsinogen activation induced by compounds are important to understand mechanism underly acute pancreatitis under various conditions. Calcium overload in the early stage of acute pancreatitis was previously found to cause intracellular trypsinogen activation; however, treatment of acute pancreatitis using calcium channel blockers did not produced consistent results. Proteasome activity that could be inhibited by some calcium channel blocker has recently been reported to affect the development of acute pancreatitis; however, the associated mechanism were not fully understood. Here, the roles of nicardipine were investigated in trypsinogen activation in pancreatic acinar cells. The results showed that nicardipine could increase cathepsin B activity that caused trypsinogen activation, but higher concentration of nicardipine or prolonged treatment had an opposite effect. The effects of short time treatment of nicardipine at low concentration were studied here. Proteasome inhibition was observed under nicardipine treatment that contributed to the up-regulation in cytosolic calcium. Increased cytosolic calcium from ER induced by nicardipine resulted in the release and activation of cathepsin B. Meanwhile, calcium chelator inhibited cathepsin B as well as trypsinogen activation. Consistently, proteasome activator protected acinar cells from injury induced by nicardipine. Moreover, proteasome inhibition caused by nicardipine depended on CaMKII. In conclusion, CaMKII down-regulation/proteasome inhibition/cytosolic calcium up-regulation/cathepsin B activation/trypsinogen activation axis was present in pancreatic acinar cells injury under nicardipine treatment.


1985 ◽  
Vol 232 (1) ◽  
pp. 237-243 ◽  
Author(s):  
G M Burgess ◽  
J S McKinney ◽  
R F Irvine ◽  
J W Putney

The inositol trisphosphate liberated on stimulation of guinea-pig hepatocytes, pancreatic acinar cells and dimethyl sulphoxide-differentiated human myelomonocytic HL-60 leukaemia cells is composed of two isomers, the 1,4,5-trisphosphate and the 1,3,4-trisphosphate. Inositol 1,4,5-trisphosphate was released rapidly, with no measurable latency on hormone stimulation, and, consistent with its proposed role as an intracellular messenger for Ca2+ mobilization, there was good temporal correlation between its formation and Ca2+-mediated events in these tissues. There was a definite latency before an increase in the formation of inositol 1,3,4-trisphosphate could be detected. In all of these tissues, however, it formed a substantial proportion of the total inositol trisphosphate by 1 min of stimulation. In guinea-pig hepatocytes, where inositol trisphosphate increases for at least 30 min after hormone application, inositol 1,3,4-trisphosphate made up about 90% of the total inositol trisphosphate by 5-10 min. In pancreatic acinar cells, pretreatment with 20 mM-Li+ caused an increase in hormone-induced inositol trisphosphate accumulation. This increase was accounted for by a rise in inositol 1,3,4-trisphosphate; inositol 1,4,5-trisphosphate was unaffected. This finding is consistent with the observation that Li+ has no effect on Ca2+-mediated responses in these cells. The role, if any, of inositol 1,3,4-trisphosphate in cellular function is unknown.


2013 ◽  
Vol 202 (3) ◽  
pp. 403-405
Author(s):  
Xavier Deschênes-Simard ◽  
Yusuke Mizukami ◽  
Nabeel Bardeesy

Chronic inflammation drives initiation and progression of many malignancies, including pancreatic cancer. In this issue, Liou et al. (2013. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201301001) report that inflammatory macrophages are major players in the earliest stages of pancreatic cancer. They show that paracrine signals from the macrophages activate the nuclear factor κB transcriptional program in normal pancreatic acinar cells, resulting in acinar–ductal metaplasia, a dedifferentiated state that is poised for oncogenic transformation.


Sign in / Sign up

Export Citation Format

Share Document