Docosahexaenoic acid inhibits zymogen activation by suppressing vacuolar ATPase activation in cerulein-stimulated pancreatic acinar cells

Multiorgan failure may not be completely resolved among people living with HIV despite HAART use. Although the chances of organ dysfunction may be relatively low, alcohol may potentiate HIV-induced toxic effects in the organs of alcohol-abusing, HIV-infected individuals. The pancreas is one of the most implicated organs, which is manifested as diabetes mellitus or pancreatic cancer. Both alcohol and HIV may trigger pancreatitis, but the combined effects have not been explored. The aim of this review is to explore the literature for understanding the mechanisms of HIV and alcohol-induced pancreatotoxicity. We found that while premature alcohol-inducing zymogen activation is a known trigger of alcoholic pancreatitis, HIV entry through C-C chemokine receptor type 5 (CCR5) into pancreatic acinar cells may also contribute to pancreatitis in people living with HIV (PLWH). HIV proteins induce oxidative and ER stresses, causing necrosis. Furthermore, infiltrative immune cells induce necrosis on HIV-containing acinar cells. When necrotic products interact with pancreatic stellate cells, they become activated, leading to the release of both inflammatory and profibrotic cytokines and resulting in pancreatitis. Effective therapeutic strategies should block CCR5 and ameliorate alcohol’s effects on acinar cells.

Download Full-text

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

Scientific Reports ◽

10.1038/s41598-019-53293-0 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 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.

Download Full-text

Inhibition of phosphatidylinositol 3-kinase inhibits intracellular zymogen activation but not enzyme secretion in pancreatic acinar cells

Journal of the American College of Surgeons ◽

10.1016/j.jamcollsurg.2006.05.029 ◽

2006 ◽

Vol 203 (3) ◽

pp. S13

Author(s):

L. Andy Chen ◽

Hiroki Watanabe ◽

B. Mark Evers

Keyword(s):

Acinar Cells ◽

Enzyme Secretion ◽

Pancreatic Acinar Cells ◽

Zymogen Activation ◽

Phosphatidylinositol 3 Kinase ◽

Phosphatidylinositol 3

Download Full-text

Pharmacological inhibition of PAR2 with the pepducin P2pal-18S protects mice against acute experimental biliary pancreatitis

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00296.2012 ◽

2013 ◽

Vol 304 (5) ◽

pp. G516-G526 ◽

Cited By ~ 21

Author(s):

E. S. Michael ◽

A. Kuliopulos ◽

L. Covic ◽

M. L. Steer ◽

G. Perides

Keyword(s):

Bile Acid ◽

Acinar Cells ◽

Experimental Pancreatitis ◽

In Vivo Studies ◽

Pancreatic Acinar Cells ◽

Biliary Pancreatitis ◽

Zymogen Activation ◽

Injury Death ◽

Acid Infusion ◽

Concentration Changes

Pancreatic acinar cells express proteinase-activated receptor-2 (PAR2) that is activated by trypsin-like serine proteases and has been shown to exert model-specific effects on the severity of experimental pancreatitis, i.e., PAR2−/− mice are protected from experimental acute biliary pancreatitis but develop more severe secretagogue-induced pancreatitis. P2pal-18S is a novel pepducin lipopeptide that targets and inhibits PAR2. In studies monitoring PAR2-stimulated intracellular Ca2+ concentration changes, we show that P2pal-18S is a full PAR2 inhibitor in acinar cells. Our in vivo studies show that P2pal-18S significantly reduces the severity of experimental biliary pancreatitis induced by retrograde intraductal bile acid infusion, which mimics injury induced by endoscopic retrograde cholangiopancreatography (ERCP). This reduction in pancreatitis severity is observed when the pepducin is given before or 2 h after bile acid infusion but not when it is given 5 h after bile acid infusion. Conversely, P2pal-18S increases the severity of secretagogue-induced pancreatitis. In vitro studies indicate that P2pal-18S protects acinar cells against bile acid-induced injury/death, but it does not alter bile acid-induced intracellular zymogen activation. These studies are the first to report the effects of an effective PAR2 pharmacological inhibitor on pancreatic acinar cells and on the severity of experimental pancreatitis. They raise the possibility that a pepducin such as P2pal-18S might prove useful in the clinical management of patients at risk for developing severe biliary pancreatitis such as occurs following ERCP.

Download Full-text

Effect of Docosahexaenoic Acid on Ca2+ Signaling Pathways in Cerulein-Treated Pancreatic Acinar Cells, Determined by RNA-Sequencing Analysis

Nutrients ◽

10.3390/nu11071445 ◽

2019 ◽

Vol 11 (7) ◽

pp. 1445

Author(s):

Kim ◽

Park ◽

Lim ◽

Kim

Keyword(s):

Acute Pancreatitis ◽

Docosahexaenoic Acid ◽

Signaling Pathways ◽

Rna Sequencing ◽

Acinar Cells ◽

Transcriptional Activator ◽

Pancreatic Acinar Cells ◽

Sequencing Analysis ◽

Omega 3 ◽

Activator Complex

Intracellular Ca2+ homeostasis is commonly disrupted in acute pancreatitis. Sustained Ca2+ release from internal stores in pancreatic acinar cells (PACs), mediated by inositol triphosphate receptor (IP3R) and the ryanodine receptor (RyR), plays a key role in the initiation and propagation of acute pancreatitis. Pancreatitis induced by cerulein, an analogue of cholecystokinin, causes premature activation of digestive enzymes and enhanced accumulation of cytokines and Ca2+ in the pancreas and, as such, it is a good model of acute pancreatitis. High concentrations of the omega-3 fatty acid docosahexaenoic acid (DHA) inhibit inflammatory signaling pathways and cytokine expression in PACs treated with cerulein. In the present study, we determined the effect of DHA on key regulators of Ca2+ signaling in cerulein-treated pancreatic acinar AR42 J cells. The results of RNA-Sequencing (RNA-Seq) analysis showed that cerulein up-regulates the expression of IP3R1 and RyR2 genes, and that pretreatment with DHA blocks these effects. The results of real-time PCR confirmed that DHA inhibits cerulein-induced IP3R1 and RyR2 gene expression, and demonstrated that DHA pre-treatment decreases the expression of the Relb gene, which encodes a component of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) transcriptional activator complex, and the c-fos gene, which encodes a component of activator protein-1 (AP-1) transcriptional activator complex. Taken together, DHA inhibits mRNA expression of IP3R1, RyR2, Relb, and c-fos, which is related to Ca2+ network in cerulein-stimulated PACs.

Download Full-text

Docosahexaenoic Acid Induces Expression of NAD(P)H: Quinone Oxidoreductase and Heme Oxygenase-1 through Activation of Nrf2 in Cerulein-Stimulated Pancreatic Acinar Cells

Antioxidants ◽

10.3390/antiox9111084 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1084

Author(s):

Yu Jin Ahn ◽

Joo Weon Lim ◽

Hyeyoung Kim

Keyword(s):

Oxidative Stress ◽

Acute Pancreatitis ◽

Docosahexaenoic Acid ◽

Heme Oxygenase ◽

Acinar Cells ◽

Pancreatic Acinar Cells ◽

Heme Oxygenase 1 ◽

Omega 3 ◽

Quinone Oxidoreductase ◽

Ar42j Cells

Oxidative stress is a major risk factor for acute pancreatitis. Reactive oxygen species (ROS) mediate expression of inflammatory cytokines such as interleukin-6 (IL-6) which reflects the severity of acute pancreatitis. The nuclear factor erythroid-2-related factor 2 (Nrf2) pathway is activated to induce the expression of antioxidant enzymes such as NAD(P)H: quinone oxidoreductase 1 (NQO1) and heme oxygenase-1 (HO-1) as a cytoprotective response to oxidative stress. In addition, binding of Kelch-like ECH-associated protein 1 (Keap1) to Nrf2 promotes degradation of Nrf2. Docosahexaenoic acid (DHA)—an omega-3 fatty acid—exerts anti-inflammatory and antioxidant effects. Oxidized omega-3 fatty acids react with Keap1 to induce Nrf2-regulated gene expression. In this study, we investigated whether DHA reduces ROS levels and inhibits IL-6 expression via Nrf2 signaling in pancreatic acinar (AR42J) cells stimulated with cerulein, as an in vitro model of acute pancreatitis. The cells were pretreated with or without DHA for 1 h and treated with cerulein (10−8 M) for 1 (ROS levels, protein levels of NQO1, HO-1, pNrf2, Nrf2, and Keap1), 6 (IL-6 mRNA expression), and 24 h (IL-6 protein level in the medium). Our results showed that DHA upregulates the expression of NQO1 and HO-1 in cerulein-stimulated AR42J cells by promoting phosphorylation and nuclear translocation of Nrf2. DHA increased interaction between Keap1 and Nrf2 in AR42J cells, which may increase Nrf2 activity by inhibiting Keap1-mediated sequestration of Nrf2. In addition, DHA-induced expression of NQO1 and HO-1 is related to reduction of ROS and IL-6 levels in cerulein-stimulated AR42J cells. In conclusion, DHA inhibits ROS-mediated IL-6 expression by upregulating Nrf2-mediated expression of NQO1 and HO-1 in cerulein-stimulated pancreatic acinar cells. DHA may exert positive modulatory effects on acute pancreatitis by inhibiting oxidative stress and inflammatory cytokine production by activating Nrf2 signaling in pancreatic acinar cells.

Download Full-text

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

Gastroenterology ◽

10.1016/s0016-5085(09)61259-2 ◽

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

Download Full-text

EFFECTS OF CALCIUM ON ZYMOGEN ACTIVATION IN MOUSE PANCREATIC ACINAR CELLS

Pancreas ◽

10.1097/01.mpa.0000193765.58426.3d ◽

2005 ◽

Vol 31 (4) ◽

pp. 469

Author(s):

R D Smith ◽

M Raraty ◽

D N Criddle ◽

O V Gerasimenko ◽

A V Tepikin ◽

...

Keyword(s):

Acinar Cells ◽

Pancreatic Acinar Cells ◽

Zymogen Activation

Download Full-text

Alcohols enhance caerulein-induced zymogen activation in pancreatic acinar cells

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00388.2001 ◽

2002 ◽

Vol 282 (3) ◽

pp. G501-G507 ◽

Cited By ~ 47

Author(s):

Zhao Lu ◽

Suresh Karne ◽

Thomas Kolodecik ◽

Fred S. Gorelick

Keyword(s):

Acinar Cell ◽

Acinar Cells ◽

Pancreatic Acinar Cell ◽

Pancreatic Acinar Cells ◽

Dependent Manner ◽

Zymogen Activation ◽

Concentration Dependent Manner ◽

Pancreatic Acini ◽

A Chain ◽

Peak Value

Activation of zymogens within the pancreatic acinar cell is an early feature of acute pancreatitis. Supraphysiological concentrations of cholecystokinin (CCK) cause zymogen activation and pancreatitis. The effects of the CCK analog, caerulein, and alcohol on trypsin and chymotrypsin activation in isolated pancreatic acini were examined. Caerulein increased markers of zymogen activation in a time- and concentration-dependent manner. Notably, trypsin activity reached a peak value within 30 min, then diminished with time, whereas chymotrypsin activity increased with time. Ethanol (35 mM) sensitized the acinar cells to the effects of caerulein (10−10 to 10−7 M) on zymogen activation but had no effect alone. The effects of ethanol were concentration dependent. Alcohols with a chain length of ≥2 also sensitized the acinar cell to caerulein; the most potent was butanol. Branched alcohols (2-propanol and 2-butanol) were less potent than aliphatic alcohols (1-propanol and 1-butanol). The structure of an alcohol is related to its ability to sensitize acinar cells to the effects of caerulein on zymogen activation.

Download Full-text