Alcohols enhance caerulein-induced zymogen activation in pancreatic acinar cells

Lei, Z. H.; Karne, Suresh; Kolodecik, Thomas R.; Gorelick, Fred S.

doi:10.1152/ajpgi.00388.2001

Cited by 66 publications

(55 citation statements)

References 27 publications

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“…Treatment of acinar cells with ethanol alone (100 mM) for 15 min had no effect on protease activity, a result consistent with previous work (18). However, administration of ethanol (100 mM) for 15 min before physiologic carbachol (1 M) stimulation caused a 2-fold increase in both trypsin and chymotrypsin activities above unstimulated controls (p Ͻ 0.02; Fig.…”

Section: Ethanol Enhances Carbachol-induced Protease Activation-supporting

confidence: 91%

“…The findings confirm recent work by Lugea et al (20). Previous studies from Gorelick and colleagues (18,33) demonstrated that ethanol sensitizes the acinar cell to CCK-induced protease activation, but they were not able to detect sensitization of ethanol to carbachol using a carboxypeptidase A1 zymogen conversion assay (33). However, both our study and that of Lugea et al (20) used selective fluorescent protease substrates, which are more sensitive in measuring changes in zymogen activity.…”

Section: Discussioncontrasting

confidence: 58%

“…It is known that ethanol enhances CCK-induced protease activation within acinar cells (18). However, there are conflicting reports as to whether the cholinergic pathways are similarly affected by ethanol (19,20).…”

Section: Ethanol Enhances Carbachol-induced Protease Activation-mentioning

confidence: 99%

“…For these reasons, we examined whether ethanol can modulate intracellular events initiated by stimulation with the ACh analog carbachol. Assays for trypsin and chymotrypsin activity were measured because the generation of these proteases closely follows first order kinetics over a 30 -60-min period of incubation (18).…”

Section: Ethanol Enhances Carbachol-induced Protease Activation-mentioning

confidence: 99%

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Ethanol Enhances Carbachol-induced Protease Activation and Accelerates Ca2+ Waves in Isolated Rat Pancreatic Acini

Orabi¹,

Shah²,

Muili

et al. 2011

Journal of Biological Chemistry

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Alcohol abuse is a leading cause of pancreatitis, accounting for 30% of acute cases and 70 -90% of chronic cases, yet the mechanisms leading to alcohol-associated pancreatic injury are unclear. An early and critical feature of pancreatitis is the aberrant signaling of Ca 2؉ within the pancreatic acinar cell. An important conductor of this Ca 2؉ is the basolaterally localized, intracellular Ca 2؉ channel ryanodine receptor (RYR). In this study, we examined the effect of ethanol on mediating both pathologic intra-acinar protease activation, a precursor to pancreatitis, as well as RYR Ca 2؉ signals. We hypothesized that ethanol sensitizes the acinar cell to protease activation by modulating RYR Ca 2؉ . Acinar cells were freshly isolated from rat, pretreated with ethanol, and stimulated with the muscarinic agonist carbachol (1 M). Ethanol caused a doubling in the carbachol-induced activation of the proteases trypsin and chymotrypsin (p < 0.02). The RYR inhibitor dantrolene abrogated the enhancement of trypsin and chymotrypsin activity by ethanol (p < 0.005 for both proteases). Further, ethanol accelerated the speed of the apical to basolateral Ca 2؉ wave from 9 to 18 m/s (p < 0.0005; n ‫؍‬ 18 -22 cells/group); an increase in Ca 2؉ wave speed was also observed with a change from physiologic concentrations of carbachol (1 M) to a supraphysiologic concentration (1 mM) that leads to protease activation. Dantrolene abrogated the ethanol-induced acceleration of wave speed (p < 0.05; n ‫؍‬ 10 -16 cells/group). Our results suggest that the enhancement of pathologic protease activation by ethanol is dependent on the RYR and that a novel mechanism for this enhancement may involve RYR-mediated acceleration of Ca 2؉ waves.Pancreatitis is a life-threatening inflammatory disorder of the pancreas that leads to more than 30,000 deaths per year (1). Alcohol-associated pancreatitis accounts for 30% of acute cases and 70 -90% of chronic cases. Further, alcoholic pancreatitis carries the highest mortality rate among all etiologies (2). However, the mechanisms by which ethanol mediates pathology are largely unknown.Alcohol can exert diverse effects on the pancreas. Ethanol exposure has been linked to abnormal blood flow, leading to ischemic changes, and increased sphincter of Oddi dysfunction, resulting in pancreatic duct hypertension (2).In addition, ethanol appears to directly predispose the acinar cell to pathological changes including oxidant stress (3), membrane fragility (4), mitochondrial uncoupling (5, 6), and basolateral exocytosis (7). Several lines of evidence also link ethanol to aberrant Ca 2ϩ 3 signaling (6). High amplitude, aberrant, intracellular Ca 2ϩ waves that propagate from the apical to basolateral region of the acinar cell predispose to early features of pancreatitis, particularly intra-acinar protease activation (8, 9). We know that intracellular Ca 2ϩ release is responsible for the onset of this aberrant Ca 2ϩ signal (10). In addition, we have previously shown that the ryanodine receptor (RYR), 4 a major intracel...

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Section: Ethanol Enhances Carbachol-induced Protease Activation-supporting

confidence: 91%

Section: Discussioncontrasting

confidence: 58%

Section: Ethanol Enhances Carbachol-induced Protease Activation-mentioning

confidence: 99%

Section: Ethanol Enhances Carbachol-induced Protease Activation-mentioning

confidence: 99%

See 2 more Smart Citations

Ethanol Enhances Carbachol-induced Protease Activation and Accelerates Ca2+ Waves in Isolated Rat Pancreatic Acini

Orabi¹,

Shah²,

Muili

et al. 2011

Journal of Biological Chemistry

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“…8e12 These high UFAs seem pathogenically relevant because several studies show UFAs can cause pancreatic acinar injury or can worsen AP. 11e14 Ethanol may play a role in AP by distinct mechanisms, 3 including a worse inflammatory response to cholecystokinin, 4 increased zymogen activation, 15 basolateral enzyme release, 16 sensitization to stress, 7 FA ethyl esters (FAEEs), 17 cytosolic calcium, 18 and cell death. 19 Because the nonoxidative ethanol metabolite of fatty acids (FAs), FAEEs, were first noted to be elevated in the pancreata of dying alcoholics, they have been thought to play a role in AP.…”

mentioning

confidence: 99%

Fatty Acid Ethyl Esters Are Less Toxic Than Their Parent Fatty Acids Generated during Acute Pancreatitis

Patel

Durgampudi

Noel

et al. 2016

The American Journal of Pathology

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Although ethanol causes acute pancreatitis (AP) and lipolytic fatty acid (FA) generation worsens AP, the contribution of ethanol metabolites of FAs, ie, FA ethyl esters (FAEEs), to AP outcomes is unclear. Previously, pancreata of dying alcoholics and pancreatic necrosis in severe AP, respectively, showed high FAEEs and FAs, with oleic acid (OA) and its ethyl esters being the most abundant. We thus compared the toxicities of FAEEs and their parent FAs in severe AP. Pancreatic acini and peripheral blood mononuclear cells were exposed to FAs or FAEEs in vitro. The triglyceride of OA (i.e., glyceryl tri-oleate) or OAEE was injected into the pancreatic ducts of rats, and local and systemic severities were studied. Unsaturated FAs at equimolar concentrations to FAEEs induced a larger increase in cytosolic calcium, mitochondrial depolarization, and necro-apoptotic cell death. Glyceryl tri-oleate but not OAEE resulted in 70% mortality with increased serum OA, a severe inflammatory response, worse pancreatic necrosis, and multisystem organ failure. Our data show that FAs are more likely to worsen AP than FAEEs. Our observations correlate well with the high pancreatic FAEE concentrations in alcoholics without pancreatitis and high FA concentrations in pancreatic necrosis. Thus, conversion of FAs to FAEE may ameliorate AP in alcoholics. (Am J Pathol 2016, 186: 874e884; http://dx.doi.org/10.1016/j.ajpath.2015 Although fat necrosis has been associated with severe cases of pancreatitis for more than a century, 1,2 and alcohol consumption is a well-known risk factor for acute pancreatitis (AP), 3 only recently have we started understanding the mechanistic basis of these observations. 4e7 High amounts of unsaturated fatty acids (UFAs) have been noted in the pancreatic necrosis and sera of severe AP (SAP) patients by multiple groups. 8e12 These high UFAs seem pathogenically relevant because several studies show UFAs can cause pancreatic acinar injury or can worsen AP. 11e14 Ethanol may play a role in AP by distinct mechanisms, 3 including a worse inflammatory response to cholecystokinin, 4 increased zymogen activation, 15 basolateral enzyme release, 16 sensitization to stress, 7 FA ethyl esters (FAEEs), 17 cytosolic calcium, 18 and cell death. 19 Because the nonoxidative ethanol metabolite of fatty acids (FAs), FAEEs, were first noted to be elevated in the pancreata of dying alcoholics, they have been thought to play a role in AP. 17,19À22 Conclusive proof of the role of FAEEs in AP in comparison with their parent UFAs is lacking. Uncontrolled release of lipases into fat, whether in the pancreas or in the peritoneal cavity, may result in fat necrosis, UFA generation, which has been associated with SAP. 11,12 Pancreatic homogenates were also noted to have an ability to synthesize FAEEs from FAs and ethanol,20,23 and the putative enzyme for this was thought to be a lipase. 24,25 It has been shown that the FAEE synthase activity of the putative enzyme exceeds its lipolytic capacity by several fold. 25 Triglyceride (TG) forms >80% ...

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Epidemiology and pathophysiology: genetic insights into pathogenesis

Whitcomb

2017

Pancreatitis

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Alcohols enhance caerulein-induced zymogen activation in pancreatic acinar cells

Cited by 66 publications

References 27 publications

Ethanol Enhances Carbachol-induced Protease Activation and Accelerates Ca2+ Waves in Isolated Rat Pancreatic Acini

Ethanol Enhances Carbachol-induced Protease Activation and Accelerates Ca2+ Waves in Isolated Rat Pancreatic Acini

Fatty Acid Ethyl Esters Are Less Toxic Than Their Parent Fatty Acids Generated during Acute Pancreatitis

Epidemiology and pathophysiology: genetic insights into pathogenesis

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