Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0030305 (pancreatitis)
 16,014 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pancreatitis complicated with infection often results in the development of multiple organ failure. We investigated the role of altered intracellular calcium as a priming signal for cytokine-induced neutrophil chemoattractant expression in this process. Agents modulating cytosolic Ca2+ were utilized to study the in vivo and in vitro cytokine-induced neutrophil chemoattractant expression for macrophages in rats with cerulein-induced pancreatitis after intraperitoneal administration of lipopolysaccharide as a septic challenge. Pretreatment with the calcium channel blocker verapamil significantly reduced serum cytokine-induced neutrophil chemoattractant concentrations in rats with cerulein-induced pancreatitis after septic challenge. Lipopolysaccharide-stimulated in vitro cytokine-induced neutrophil chemoattractant (CINC) production by peritoneal macrophages was significantly enhanced by pretreatment with thapsigargin (an inhibitor of the endoplasmic reticulum-resident Ca2+-ATPase), but not by A23187 (a calcium-specific ionophore, extracellular Ca2+ influx). Pretreatment with U73122 (a phospholipase C inhibitor) inhibited lipopolysaccharide-stimulated but not basal cytokine-induced neutrophil chemoattractant production, while verapamil (a calcium channel blocker), TMB-8 (an inhibitor of calcium release from endoplasmic reticulum), and W7 (calmodulin antagonist) completely abrogated the chemoattractant production. Altered intracellular calcium, due to Ca2+ efflux from intracellular stores, may be involved in the "priming" of macrophages to release cytokine-induced neutrophil chemoattractant following triggering with lipopolysaccharide during acute cerulein pancreatitis.
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PMID:Intracellular calcium affects neutrophil chemoattractant expression by macrophages in rats with cerulein-induced pancreatitis. 955 45

We investigated the role of platelet-activating factor (PAF) as a priming signal for cytokine-induced neutrophil chemoattractant (CINC) expression by bronchoalveolar macrophages in acute pancreatitis. Pancreatitis was induced by four intramuscular injections of cerulein (50 micrograms/kg at 1-h intervals) in Wistar rats. The animals were injected intraperitoneally with 10 micrograms/kg of lipopolysaccharide (LPS) as a septic challenge. Pancreatitis rats were treated with a bolus intravenous injection of TCV-309 (3 or 30 micrograms/kg) 30 min before the septic challenge. Intense mononuclear cell infiltration and lung hemorrhage occurred in pancreatitis rats complicated with sepsis but were not seen in pancreatitis rats receiving a bolus TCV-309. Pancreatitis rats treated with TCV-309 had lower serum concentrations of CINC after septic challenge and lower levels of CINC messenger RNA (mRNA) in the lung, as well as fewer pulmonary infiltrates immunoreactive for CINC or Mac-1 (CD11b/CD18). In vitro CINC production in response to LPS by bronchoalveolar macrophages obtained from pancreatitis rats 6 h after the first cerulein injection, immediately before septic challenge, was enhanced but was significantly reduced in a TCV-309-sensitive manner. LPS-stimulated in vitro CINC production by naive bronchoalveolar macrophages was significantly enhanced by pretreatment with PAF. TMB-8 (an inhibitor of calcium release from endoplasmic reticulum) or W7 (calmodulin antagonist) completely abrogated the chemoattractant production by bronchoalveolar macrophages pretreated with PAF after LPS stimulation. Altered intracellular calcium, due to Ca2+ efflux from intracellular stores, may be involved in the "priming" of bronchoalveolar macrophages to release CINC after triggering with LPS during acute cerulein-induced pancreatitis. The PAF antagonist TCV-309 effectively prevented hyperactivity of bronchoalveolar macrophages and pancreatitis-associated lung injury after the septic challenge.
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PMID:Platelet-activating factor antagonist (TCV-309) attenuates the priming effects of bronchoalveolar macrophages in cerulein-induced pancreatitis rats. 1023 40

The eukaryotic transcription factor NF-kappaB/Rel is activated by a large variety of stimuli. We have recently shown that NF-kappaB/Rel is induced during the course of caerulein pancreatitis. Here, we show that activation of NF-kappaB/Rel by caerulein, a CCK analog, requires increasing intracellular Ca2+ levels and protein kinase C activation. Caerulein induces a dose-dependent increase of nuclear NF-kappaB/Rel binding activity in pancreatic lobules, which is paralleled by degradation of IkappaBalpha. IkappaBbeta was only slightly affected by caerulein treatment. Consistent with an involvement of Ca2+, the endoplasmic reticulum-resident Ca2+-ATPase inhibitor thapsigargin activated NF-kappaB/Rel in pancreatic lobules. The intracellular Ca2+ chelator TMB-8 prevented IkappaBalpha degradation and subsequent nuclear translocation of NF-kappaB/Rel induced by caerulein. BAPTA-AM was less effective. Cyclosporin A, a Ca2+/calmodulin-dependent protein phosphatase (PP2B) inhibitor, decreased caerulein-induced NF-kappaB/Rel activation and IkappaBalpha degradation. The inhibitory effect of bisindolylmaleimide suggests that protein kinase C activity is also required for caerulein-induced NF-kappaB/Rel activation. These data suggest that Ca2+- as well as protein kinase C-dependent mechanisms are required for caerulein-induced NF-kappaB/Rel activation.
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PMID:Caerulein-induced NF-kappaB/Rel activation requires both Ca2+ and protein kinase C as messengers. 1048 94

The premature activation of digestive proenzymes, specifically proteases, within the pancreatic acinar cell is an early and critical event during acute pancreatitis. Our previous studies demonstrate that this activation requires a distinct pathological rise in cytosolic Ca(2+). Furthermore, we have shown that a target of aberrant Ca(2+) in acinar cells is the Ca(2+)/calmodulin-dependent phosphatase calcineurin (PP2B). In this study, we hypothesized that PP2B mediates in vivo protease activation and pancreatitis severity. To test this, pancreatitis was induced in mice over 8 h by administering hourly intraperitoneal injections of the cholecystokinin analog caerulein (50 microg/kg). Treatment with the PP2B inhibitor FK506 at 1 and 8 h after pancreatitis induction reduced trypsin activities by greater than 50% (P < 0.005). Serum amylase and IL-6 was reduced by 86 and 84% relative to baseline (P < 0.0005) at 8 h, respectively. Histological severity of pancreatitis, graded on the basis of pancreatic edema, acinar cell vacuolization, inflammation, and apoptosis, was reduced early in the course of pancreatitis. Myeloperoxidase activity from both pancreas and lung was reduced by 93 and 83% relative to baseline, respectively (P < 0.05). These data suggest that PP2B is an important target of the aberrant acinar cell Ca(2+) rise associated with pathological protease activation and pancreatitis.
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PMID:Protease activation during in vivo pancreatitis is dependent on calcineurin activation. 2050 44

Alcohol abuse is a major global health problem, but there is still much uncertainty about the mechanisms of action. So far, the effects of ethanol on ion channels in the plasma membrane have received the most attention. We have now investigated actions on intracellular calcium channels in pancreatic acinar cells. Our aim was to discover the mechanism by which alcohol influences calcium homeostasis and thereby understand how alcohol can trigger premature intracellular trypsinogen activation, which is the initiating step for alcohol-induced pancreatitis. We used intact or two-photon permeabilized acinar cells isolated from wild-type mice or mice in which inositol trisphosphate receptors of type 2 or types 2 and 3 were knocked out. In permeabilized pancreatic acinar cells even a relatively low ethanol concentration elicited calcium release from intracellular stores and intracellular trypsinogen activation. The calcium sensor calmodulin (at a normal intracellular concentration) markedly reduced ethanol-induced calcium release and trypsinogen activation in permeabilized cells, effects prevented by the calmodulin inhibitor peptide. A calmodulin activator virtually abolished the modest ethanol effects in intact cells. Both ethanol-elicited calcium liberation and trypsinogen activation were significantly reduced in cells from type 2 inositol trisphosphate receptor knockout mice. More profound reductions were seen in cells from double inositol trisphosphate receptor (types 2 and 3) knockout mice. The inositol trisphosphate receptors, required for normal pancreatic stimulus-secretion coupling, are also responsible for the toxic ethanol action. Calmodulin protects by reducing calcium release sensitivity.
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PMID:Calmodulin protects against alcohol-induced pancreatic trypsinogen activation elicited via Ca2+ release through IP3 receptors. 2143 55

There is growing evidence that intracellular calcium plays a primary role in the pathophysiology of the pancreas in addition to its crucial importance in major physiological functions. Pancreatic acinar cells have a remarkably large amount of Ca(2+) stored in both the endoplasmic reticulum (ER) and the acidic stores. The vast majority of the classical ER Ca(2+) store is located in the basal part of the acinar cells with extensions protruding into the apical area, however, the acidic stores are exclusively located in the secretory granular area of the cells. Both types of Ca(2+) store respond to all three intracellular Ca(2+) messengers - inositol trisphosphate (InsP3), cyclic-ADP-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate (NAADP). The two stores interact with each other via calcium-induced calcium release; however, they can be separated using pharmacological tools. The ER relies on sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) that can be blocked by the specific inhibitor thapsigargin. The acidic store requires a low pH that can be modified by blocking vacuolar H(+)-ATPase. The acidic store is particularly important for pathological processes in the pancreas. Acute pancreatitis is initiated as a result of calcium overload in the apical pole, which leads to trypsinogen activation; two major causes are gall bladder stones and excessive alcohol consumption. Excessive Ca(2+) release from the acidic stores plays a major role in both scenarios; however NAADP-induced calcium release from acidic stores is particularly important for bile-induced pancreatitis. Cell-permeable calmodulin (CaM) activators such as CALP3 boost the natural protective effect of CaM by inhibiting excessive calcium release from the internal stores through inositol trisphosphate (InsP3R) and ryanodine receptors (RyR). Alternatively calcium overload can be dramatically reduced by inhibiting Ca(2+)-release-activated Ca(2+) (CRAC) currents that are required to reload the internal stores and therefore provide effective protection against the major triggers of acute pancreatitis.
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PMID:Role of acidic stores in secretory epithelia. 2483 5