1
|
Silke J, O’Reilly LA. NF-κB and Pancreatic Cancer; Chapter and Verse. Cancers (Basel) 2021; 13:4510. [PMID: 34572737 PMCID: PMC8469693 DOI: 10.3390/cancers13184510] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/29/2021] [Accepted: 08/30/2021] [Indexed: 02/07/2023] Open
Abstract
Pancreatic Ductal Adenocarcinoma (PDAC) is one of the world's most lethal cancers. An increase in occurrence, coupled with, presently limited treatment options, necessitates the pursuit of new therapeutic approaches. Many human cancers, including PDAC are initiated by unresolved inflammation. The transcription factor NF-κB coordinates many signals that drive cellular activation and proliferation during immunity but also those involved in inflammation and autophagy which may instigate tumorigenesis. It is not surprising therefore, that activation of canonical and non-canonical NF-κB pathways is increasingly recognized as an important driver of pancreatic injury, progression to tumorigenesis and drug resistance. Paradoxically, NF-κB dysregulation has also been shown to inhibit pancreatic inflammation and pancreatic cancer, depending on the context. A pro-oncogenic or pro-suppressive role for individual components of the NF-κB pathway appears to be cell type, microenvironment and even stage dependent. This review provides an outline of NF-κB signaling, focusing on the role of the various NF-κB family members in the evolving inflammatory PDAC microenvironment. Finally, we discuss pharmacological control of NF-κB to curb inflammation, focussing on novel anti-cancer agents which reinstate the process of cancer cell death, the Smac mimetics and their pre-clinical and early clinical trials.
Collapse
Affiliation(s)
- John Silke
- Inflammation Division, Walter and Eliza Hall Institute of Medical Research (WEHI), Parkville, VIC 3052, Australia;
- Department of Medical Biology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Lorraine Ann O’Reilly
- Inflammation Division, Walter and Eliza Hall Institute of Medical Research (WEHI), Parkville, VIC 3052, Australia;
- Department of Medical Biology, University of Melbourne, Parkville, VIC 3010, Australia
| |
Collapse
|
2
|
Sharma V, Aggarwal A, Jacob J, Sahni D. Myeloid-derived suppressor cells: Bridging the gap between inflammation and pancreatic adenocarcinoma. Scand J Immunol 2021; 93:e13021. [PMID: 33455004 DOI: 10.1111/sji.13021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 01/09/2021] [Accepted: 01/10/2021] [Indexed: 12/29/2022]
Abstract
Pancreatic cancer has been identified as one of the deadliest malignancies because it remains asymptomatic and usually presents in the advanced stage. Tumour immune evasion is a well-known mechanism of tumorigenesis in various forms of human malignancies. Chronic inflammation via complex networking of various inflammatory cytokines in the local tissue microenvironment dysregulates the immune system and support tumour development. Pro-inflammatory mediators present in the tumour microenvironment increase the tumour burden by causing immune suppression through the generation of myeloid-derived suppressor cells (MDSCs) and T regulatory cells. These cells, along-with myofibroblasts, create a highly immunosuppressive and resistant tumour microenvironment and are thus considered as one of the culprits for the failure of anti-cancer chemotherapies in pancreatic adenocarcinoma patients. Targeting these MDSCs using various combinatorial approaches might have the potential for abrogating the resistance and suppressive nature of the pancreatic tumour microenvironment. Therefore, there is more curiosity in studying the crosstalk of MDSCs with other immune cells during pathological conditions and the underlying mechanisms of immunosuppression in the current scenario. In this article, the possible role of MDSCs in inflammation-mediated tumour progression of pancreatic adenocarcinoma has been discussed.
Collapse
Affiliation(s)
- Vinit Sharma
- Department of Anatomy, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Anjali Aggarwal
- Department of Anatomy, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Justin Jacob
- Department of Anatomy, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Daisy Sahni
- Department of Anatomy, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| |
Collapse
|
3
|
Jakkampudi A, Jangala R, Reddy R, Reddy B, Venkat Rao G, Pradeep R, Nageshwar Reddy D, Talukdar R. Fatty acid ethyl ester (FAEE) associated acute pancreatitis: An ex-vivo study using human pancreatic acini. Pancreatology 2020; 20:1620-1630. [PMID: 33077383 DOI: 10.1016/j.pan.2020.10.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 09/09/2020] [Accepted: 10/08/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIM Fatty acid ethyl esters (FAEEs), are produced by non-oxidative alcohol metabolism and can cause acinar cell damage and subsequent acute pancreatitis in rodent models. Even though experimental studies have elucidated the FAEE mediated early intra-acinar events, these mechanisms have not been well studied in humans. In the present study, we evaluate the early intra-acinar events and inflammatory response in human pancreatic acinar tissues and cells in an ex-vivo model. METHODS Experiments were conducted using normal human pancreatic tissues exposed to FAEE. Subcellular fractionation was performed on tissue homogenates and trypsin and cathepsin B activities were estimated in these fractions. Acinar cell injury was evaluated by histology and immunohistochemistry. Cytokine release from exposed acinar cells was evaluated by performing Immuno-fluorescence. Serum was collected from patients with AP within the first 72 h of symptom onset for cytokine estimation using FACS. RESULTS We observed significant trypsin activation and acinar cell injury in FAEE treated tissue. Cathepsin B was redistributed from lysosomal to zymogen compartment at 30 min of FAEE exposure. IHC results indicated the presence of apoptosis in pancreatic tissue at 1 & 2hrs of FAEE exposure. We also observed a time dependent increase in secretion of cytokines IL-6, IL-8, TNF-α from FAEE treated acinar tissue. There was also a significant elevation in plasma cytokines in patents with alcohol associated AP within 72 h of symptom onset. CONCLUSION Our data suggest that alcohol metabolites can cause acute acinar cell damage and subsequent cytokine release which could eventually culminant in SIRS.
Collapse
Affiliation(s)
- Aparna Jakkampudi
- Wellcome-DBT India Alliance Labs., Institute of Basic and Translational Research, Asian Healthcare Foundation, India
| | - Ramaiah Jangala
- Wellcome-DBT India Alliance Labs., Institute of Basic and Translational Research, Asian Healthcare Foundation, India
| | - Ratnakar Reddy
- Wellcome-DBT India Alliance Labs., Institute of Basic and Translational Research, Asian Healthcare Foundation, India
| | - Balkumar Reddy
- Wellcome-DBT India Alliance Labs., Institute of Basic and Translational Research, Asian Healthcare Foundation, India
| | - G Venkat Rao
- Wellcome-DBT India Alliance Labs., Institute of Basic and Translational Research, Asian Healthcare Foundation, India; Dept. of Surgical Gastroenterology, Asian Institute of Gastroenterology, India
| | - Rebala Pradeep
- Wellcome-DBT India Alliance Labs., Institute of Basic and Translational Research, Asian Healthcare Foundation, India; Dept. of Surgical Gastroenterology, Asian Institute of Gastroenterology, India
| | - D Nageshwar Reddy
- Wellcome-DBT India Alliance Labs., Institute of Basic and Translational Research, Asian Healthcare Foundation, India; Dept. of Medical Gastroenterology, Asian Institute of Gastroenterology, India
| | - Rupjyoti Talukdar
- Wellcome-DBT India Alliance Labs., Institute of Basic and Translational Research, Asian Healthcare Foundation, India; Dept. of Medical Gastroenterology, Asian Institute of Gastroenterology, India.
| |
Collapse
|
4
|
Jeong YK, Lee S, Lim JW, Kim H. Docosahexaenoic Acid Inhibits Cerulein-Induced Acute Pancreatitis in Rats. Nutrients 2017; 9:E744. [PMID: 28704954 PMCID: PMC5537858 DOI: 10.3390/nu9070744] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/05/2017] [Accepted: 07/06/2017] [Indexed: 12/11/2022] Open
Abstract
Oxidative stress is an important regulator in the pathogenesis of acute pancreatitis (AP). Reactive oxygen species induce activation of inflammatory cascades, inflammatory cell recruitment, and tissue damage. NF-κB regulates inflammatory cytokine gene expression, which induces an acute, edematous form of pancreatitis. Protein kinase C δ (PKCδ) activates NF-κB as shown in a mouse model of cerulein-induced AP. Docosahexaenoic acid (DHA), an ω-3 fatty acid, exerts anti-inflammatory and antioxidant effects in various cells and tissues. This study investigated whether DHA inhibits cerulein-induced AP in rats by assessing pancreatic edema, myeloperoxidase activity, levels of lipid peroxide and IL-6, activation of NF-κB and PKCδ, and by histologic observation. AP was induced by intraperitoneal injection (i.p.) of cerulein (50 μg/kg) every hour for 7 h. DHA (13 mg/kg) was administered i.p. for three days before AP induction. Pretreatment with DHA reduced cerulein-induced activation of NF-κB, PKCδ, and IL-6 in pancreatic tissues of rats. DHA suppressed pancreatic edema and decreased the abundance of lipid peroxide, myeloperoxidase activity, and inflammatory cell infiltration into the pancreatic tissues of cerulein-stimulated rats. Therefore, DHA may help prevent the development of pancreatitis by suppressing the activation of NF-κB and PKCδ, expression of IL-6, and oxidative damage to the pancreas.
Collapse
Affiliation(s)
- Yoo Kyung Jeong
- Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul 03722, Korea.
| | - Sle Lee
- Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul 03722, Korea.
| | - Joo Weon Lim
- Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul 03722, Korea.
| | - Hyeyoung Kim
- Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul 03722, Korea.
| |
Collapse
|
5
|
Pin CL, Ryan JF, Mehmood R. Acinar cell reprogramming: a clinically important target in pancreatic disease. Epigenomics 2015; 7:267-81. [PMID: 25942535 DOI: 10.2217/epi.14.83] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Acinar cells of the pancreas produce the majority of enzymes required for digestion and make up >90% of the cells within the pancreas. Due to a common developmental origin and the plastic nature of the acinar cell phenotype, these cells have been identified as a possible source of β cells as a therapeutic option for Type I diabetes. However, recent evidence indicates that acinar cells are the main source of pancreatic intraepithelial neoplasias (PanINs), the predecessor of pancreatic ductal adenocarcinoma (PDAC). The conversion of acinar cells to either β cells or precursors to PDAC is dependent on reprogramming of the cells to a more primitive, progenitor-like phenotype, which involves changes in transcription factor expression and activity, and changes in their epigenetic program. This review will focus on the mechanisms that promote acinar cell reprogramming, as well as the factors that may affect these mechanisms.
Collapse
Affiliation(s)
- Christopher L Pin
- Department of Paediatrics, Physiology & Pharmacology, & Oncology, University of Western Ontario, London, ON N6C 2V5, Canada
| | | | | |
Collapse
|
6
|
Jin S, Orabi AI, Le T, Javed TA, Sah S, Eisses JF, Bottino R, Molkentin JD, Husain SZ. Exposure to Radiocontrast Agents Induces Pancreatic Inflammation by Activation of Nuclear Factor-κB, Calcium Signaling, and Calcineurin. Gastroenterology 2015; 149:753-64.e11. [PMID: 25980752 PMCID: PMC4550538 DOI: 10.1053/j.gastro.2015.05.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 05/05/2015] [Accepted: 05/06/2015] [Indexed: 12/26/2022]
Abstract
BACKGROUND & AIMS Radiocontrast agents are required for radiographic procedures, but these agents can injure tissues by unknown mechanisms. We investigated whether exposure of pancreatic tissues to radiocontrast agents during endoscopic retrograde cholangiopancreatography (ERCP) causes pancreatic inflammation, and studied the effects of these agents on human cell lines and in mice. METHODS We exposed mouse and human acinar cells to the radiocontrast agent iohexol (Omnipaque; GE Healthcare, Princeton, NJ) and measured intracellular release of Ca(2+), calcineurin activation (using a luciferase reporter), activation of nuclear factor-κB (NF-κB, using a luciferase reporter), and cell necrosis (via propidium iodide uptake). We infused the radiocontrast agent into the pancreatic ducts of wild-type mice (C57BL/6) to create a mouse model of post-ERCP pancreatitis; some mice were given intraperitoneal injections of the calcineurin inhibitor FK506 before and after infusion of the radiocontrast agent. CnAβ(-/-) mice also were used. This experiment also was performed in mice given infusions of adeno-associated virus 6-NF-κB-luciferase, to assess activation of this transcription factor in vivo. RESULTS Incubation of mouse and human acinar cells, but not HEK293 or COS7 cells, with iohexol led to a peak and then plateau in Ca(2+) signaling, along with activation of the transcription factors NF-κB and nuclear factor of activated T cells. Suppressing Ca(2+) signaling or calcineurin with BAPTA, cyclosporine A, or FK506 prevented activation of NF-κB and acinar cell injury. Calcineurin Aβ-deficient mice were protected against induction of pancreatic inflammation by iohexol. The calcineurin inhibitor FK506 prevented contrast-induced activation of NF-κB in pancreata of mice, this was observed by live imaging of mice given infusions of adeno-associated virus 6-NF-κB-luciferase. CONCLUSIONS Radiocontrast agents cause pancreatic inflammation in mice, via activation of NF-κB, Ca(2+) signaling, and calcineurin. Calcineurin inhibitors might be developed to prevent post-ERCP pancreatitis in patients.
Collapse
Affiliation(s)
- Shunqian Jin
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224
| | - Abrahim I. Orabi
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224
| | - Tianming Le
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224
| | - Tanveer A. Javed
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224
| | - Swati Sah
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224
| | - John F. Eisses
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224
| | - Rita Bottino
- Institute of Cellular Therapeutics, Allegheny General Hospital, Pittsburgh, PA, 15212
| | - Jeffery D. Molkentin
- Department of Pediatrics, University of Cincinnati, Cincinnati Children’s Hospital Medical Center, Howard Hughes Medical Institute, Cincinnati, OH, 45229
| | - Sohail Z. Husain
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15224
| |
Collapse
|
7
|
Kolodecik T, Shugrue C, Ashat M, Thrower EC. Risk factors for pancreatic cancer: underlying mechanisms and potential targets. Front Physiol 2014; 4:415. [PMID: 24474939 PMCID: PMC3893685 DOI: 10.3389/fphys.2013.00415] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 12/30/2013] [Indexed: 12/16/2022] Open
Abstract
PURPOSE OF THE REVIEW Pancreatic cancer is extremely aggressive, forming highly chemo-resistant tumors, and has one of the worst prognoses. The evolution of this cancer is multi-factorial. Repeated acute pancreatic injury and inflammation are important contributing factors in the development of pancreatic cancer. This article attempts to understand the common pathways linking pancreatitis to pancreatic cancer. RECENT FINDINGS Intracellular activation of both pancreatic enzymes and the transcription factor NF-κB are important mechanisms that induce acute pancreatitis (AP). Recurrent pancreatic injury due to genetic susceptibility, environmental factors such as smoking, alcohol intake, and conditions such as obesity lead to increases in oxidative stress, impaired autophagy and constitutive activation of inflammatory pathways. These processes can stimulate pancreatic stellate cells, thereby increasing fibrosis and encouraging chronic disease development. Activation of oncogenic Kras mutations through inflammation, coupled with altered levels of tumor suppressor proteins (p53 and p16) can ultimately lead to development of pancreatic cancer. SUMMARY Although our understanding of pancreatitis and pancreatic cancer has tremendously increased over many years, much remains to be elucidated in terms of common pathways linking these conditions.
Collapse
Affiliation(s)
- Thomas Kolodecik
- Digestive Diseases Section, Department of Internal Medicine, Yale UniversityNew Haven, CT, USA
- VA HealthcareWest Haven, CT, USA
| | - Christine Shugrue
- Digestive Diseases Section, Department of Internal Medicine, Yale UniversityNew Haven, CT, USA
- VA HealthcareWest Haven, CT, USA
| | - Munish Ashat
- Digestive Diseases Section, Department of Internal Medicine, Yale UniversityNew Haven, CT, USA
- VA HealthcareWest Haven, CT, USA
| | - Edwin C. Thrower
- Digestive Diseases Section, Department of Internal Medicine, Yale UniversityNew Haven, CT, USA
- VA HealthcareWest Haven, CT, USA
| |
Collapse
|
8
|
Weber H, Jonas L, Wakileh M, Krüger B. Beneficial effect of the bioflavonoid quercetin on cholecystokinin-induced mitochondrial dysfunction in isolated rat pancreatic acinar cells. Can J Physiol Pharmacol 2013; 92:215-25. [PMID: 24593786 DOI: 10.1139/cjpp-2013-0112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The pathogenesis of acute pancreatitis (AP) is still poorly understood. Thus, a reliable pharmacological therapy is currently lacking. In recent years, an impairment of the energy metabolism of pancreatic acinar cells, caused by Ca(2+)-mediated depolarization of the inner mitochondrial membrane and a decreased ATP supply, has been implicated as an important pathological event. In this study, we investigated whether quercetin exerts protection against mitochondrial dysfunction. Following treatment with or without quercetin, rat pancreatic acinar cells were stimulated with supramaximal cholecystokinin-8 (CCK). CCK caused a decrease in the mitochondrial membrane potential (MMP) and ATP concentration, whereas the mitochondrial dehydrogenase activity was significantly increased. Quercetin treatment before CCK application exerted no protection on MMP but increased ATP to a normal level, leading to a continuous decrease in the dehydrogenase activity. The protective effect of quercetin on mitochondrial function was accompanied by a reduction in CCK-induced changes to the cell membrane. Concerning the molecular mechanism underlying the protective effect of quercetin, an increased AMP/ATP ratio suggests that the AMP-activated protein kinase system may be activated. In addition, quercetin strongly inhibited CCK-induced trypsin activity. The results indicate that the use of quercetin may be a therapeutic strategy for reducing the severity of AP.
Collapse
Affiliation(s)
- Heike Weber
- a Institute of Clinical Chemistry and Laboratory Medicine, University of Rostock, Ernst-Heydemann-Straße 6, 18057 Rostock, Germany
| | | | | | | |
Collapse
|
9
|
Muili KA, Jin S, Orabi AI, Eisses JF, Javed TA, Le T, Bottino R, Jayaraman T, Husain SZ. Pancreatic acinar cell nuclear factor κB activation because of bile acid exposure is dependent on calcineurin. J Biol Chem 2013; 288:21065-21073. [PMID: 23744075 DOI: 10.1074/jbc.m113.471425] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Biliary pancreatitis is the most common etiology of acute pancreatitis, accounting for 30-60% of cases. A dominant theory for the development of biliary pancreatitis is the reflux of bile into the pancreatic duct and subsequent exposure to pancreatic acinar cells. Bile acids are known to induce aberrant Ca(2+) signals in acinar cells as well as nuclear translocation of NF-κB. In this study, we examined the role of the downstream Ca(2+) target calcineurin on NF-κB translocation. Freshly isolated mouse acinar cells were infected for 24 h with an adenovirus expressing an NF-κB luciferase reporter. The bile acid taurolithocholic acid-3-sulfate caused NF-κB activation at concentrations (500 μm) that were associated with cell injury. We show that the NF-κB inhibitor Bay 11-7082 (1 μm) blocked translocation and injury. Pretreatment with the Ca(2+) chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, the calcineurin inhibitors FK506 and cyclosporine A, or use of acinar cells from calcineurin Aβ-deficient mice each led to reduced NF-κB activation with taurolithocholic acid-3-sulfate. Importantly, these manipulations did not affect LPS-induced NF-κB activation. A critical upstream regulator of NF-κB activation is protein kinase C, which translocates to the membranes of various organelles in the active state. We demonstrate that pharmacologic and genetic inhibition of calcineurin blocks translocation of the PKC-δ isoform. In summary, bile-induced NF-κB activation and acinar cell injury are mediated by calcineurin, and a mechanism for this important early inflammatory response appears to be upstream at the level of PKC translocation.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Rita Bottino
- Internal Medicine, Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center and the University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Thotalla Jayaraman
- Internal Medicine, Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center and the University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | | |
Collapse
|
10
|
SHALBUEVA NATALIA, MARENINOVA OLGAA, GERLOFF ANDREAS, YUAN JINGZHEN, WALDRON RICHARDT, PANDOL STEPHENJ, GUKOVSKAYA ANNAS. Effects of oxidative alcohol metabolism on the mitochondrial permeability transition pore and necrosis in a mouse model of alcoholic pancreatitis. Gastroenterology 2013; 144:437-446.e6. [PMID: 23103769 PMCID: PMC3841074 DOI: 10.1053/j.gastro.2012.10.037] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 09/24/2012] [Accepted: 10/17/2012] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Opening of the mitochondrial permeability transition pore (MPTP) causes loss of the mitochondrial membrane potential (ΔΨm) and, ultimately, adenosine triphosphate depletion and necrosis. Cells deficient in cyclophilin D (CypD), a component of the MPTP, are resistant to MPTP opening, loss of ΔΨm, and necrosis. Alcohol abuse is a major risk factor for pancreatitis and is believed to sensitize the pancreas to stressors, by poorly understood mechanisms. We investigated the effects of ethanol on the pancreatic MPTP, the mechanisms of these effects, and their role in pancreatitis. METHODS We measured ΔΨm in mouse pancreatic acinar cells incubated with ethanol alone and in combination with physiologic and pathologic concentrations of cholecystokinin-8 (CCK). To examine the role of MPTP, we used ex vivo and in vivo models of pancreatitis, induced in wild-type and CypD(-/-) mice by a combination of ethanol and CCK. RESULTS Ethanol reduced basal ΔΨm and converted a transient depolarization, induced by physiologic concentrations of CCK, into a sustained decrease in ΔΨm, resulting in reduced cellular adenosine triphosphate and increased necrosis. The effects of ethanol and CCK were mediated by MPTP because they were not observed in CypD(-/-) acinar cells. Ethanol and CCK activated MPTP through different mechanisms-ethanol by reducing the ratio of oxidized nicotinamide adenine dinucleotide to reduced nicotinamide adenine dinucleotide, as a result of oxidative metabolism, and CCK by increasing cytosolic Ca(2+). CypD(-/-) mice developed a less-severe form of pancreatitis after administration of ethanol and CCK. CONCLUSIONS Oxidative metabolism of ethanol sensitizes pancreatic mitochondria to activate MPTP, leading to mitochondrial failure; this makes the pancreas susceptible to necrotizing pancreatitis.
Collapse
Affiliation(s)
- NATALIA SHALBUEVA
- Veterans Affairs Greater Los Angeles Healthcare System, David Geffen School of Medicine, University of California at Los Angeles, Southern California Research Center for Alcoholic Liver and Pancreatic Disease and Cirrhosis, Los Angeles, California,Institute of General and Experimental Biology, Russian Academy of Sciences, Siberian Branch, Ulan-Ude, Russian Federation
| | - OLGA A. MARENINOVA
- Veterans Affairs Greater Los Angeles Healthcare System, David Geffen School of Medicine, University of California at Los Angeles, Southern California Research Center for Alcoholic Liver and Pancreatic Disease and Cirrhosis, Los Angeles, California
| | - ANDREAS GERLOFF
- Veterans Affairs Greater Los Angeles Healthcare System, David Geffen School of Medicine, University of California at Los Angeles, Southern California Research Center for Alcoholic Liver and Pancreatic Disease and Cirrhosis, Los Angeles, California
| | - JINGZHEN YUAN
- Veterans Affairs Greater Los Angeles Healthcare System, David Geffen School of Medicine, University of California at Los Angeles, Southern California Research Center for Alcoholic Liver and Pancreatic Disease and Cirrhosis, Los Angeles, California
| | - RICHARD T. WALDRON
- Veterans Affairs Greater Los Angeles Healthcare System, David Geffen School of Medicine, University of California at Los Angeles, Southern California Research Center for Alcoholic Liver and Pancreatic Disease and Cirrhosis, Los Angeles, California
| | - STEPHEN J. PANDOL
- Veterans Affairs Greater Los Angeles Healthcare System, David Geffen School of Medicine, University of California at Los Angeles, Southern California Research Center for Alcoholic Liver and Pancreatic Disease and Cirrhosis, Los Angeles, California
| | - ANNA S. GUKOVSKAYA
- Veterans Affairs Greater Los Angeles Healthcare System, David Geffen School of Medicine, University of California at Los Angeles, Southern California Research Center for Alcoholic Liver and Pancreatic Disease and Cirrhosis, Los Angeles, California
| |
Collapse
|
11
|
Muili KA, Wang D, Orabi AI, Sarwar S, Luo Y, Javed TA, Eisses JF, Mahmood SM, Jin S, Singh VP, Ananthanaravanan M, Perides G, Williams JA, Molkentin JD, Husain SZ. Bile acids induce pancreatic acinar cell injury and pancreatitis by activating calcineurin. J Biol Chem 2013; 288:570-80. [PMID: 23148215 PMCID: PMC3537054 DOI: 10.1074/jbc.m112.428896] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 11/08/2012] [Indexed: 12/29/2022] Open
Abstract
Biliary pancreatitis is the leading cause of acute pancreatitis in both children and adults. A proposed mechanism is the reflux of bile into the pancreatic duct. Bile acid exposure causes pancreatic acinar cell injury through a sustained rise in cytosolic Ca(2+). Thus, it would be clinically relevant to know the targets of this aberrant Ca(2+) signal. We hypothesized that the Ca(2+)-activated phosphatase calcineurin is such a Ca(2+) target. To examine calcineurin activation, we infected primary acinar cells from mice with an adenovirus expressing the promoter for a downstream calcineurin effector, nuclear factor of activated T-cells (NFAT). The bile acid taurolithocholic acid-3-sulfate (TLCS) was primarily used to examine bile acid responses. TLCS caused calcineurin activation only at concentrations that cause acinar cell injury. The activation of calcineurin by TLCS was abolished by chelating intracellular Ca(2+). Pretreatment with 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (acetoxymethyl ester) (BAPTA-AM) or the three specific calcineurin inhibitors FK506, cyclosporine A, or calcineurin inhibitory peptide prevented bile acid-induced acinar cell injury as measured by lactate dehydrogenase leakage and propidium iodide uptake. The calcineurin inhibitors reduced the intra-acinar activation of chymotrypsinogen within 30 min of TLCS administration, and they also prevented NF-κB activation. In vivo, mice that received FK506 or were deficient in the calcineurin isoform Aβ (CnAβ) subunit had reduced pancreatitis severity after infusion of TLCS or taurocholic acid into the pancreatic duct. In summary, we demonstrate that acinar cell calcineurin is activated in response to Ca(2+) generated by bile acid exposure, bile acid-induced pancreatic injury is dependent on calcineurin activation, and calcineurin inhibitors may provide an adjunctive therapy for biliary pancreatitis.
Collapse
Affiliation(s)
| | - Dong Wang
- From the Department of Pediatrics and
- the Department of Chemistry, Fudan University, Shanghai 200433, China
- the Institute of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | | | | | | | | | | | | | | | - Vijay P. Singh
- Internal Medicine, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center and the University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Meena Ananthanaravanan
- the Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06519
| | - George Perides
- the Department of Surgery, Tufts University Medical Center, Boston, Massachusetts 02111
| | - John A. Williams
- the Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, and
| | - Jeffery D. Molkentin
- the Department of Pediatrics, University of Cincinnati, Cincinnati Children's Hospital Medical Center, Howard Hughes Medical Institute, Cincinnati, Ohio 45229
| | | |
Collapse
|
12
|
Kim SO, Ives KL, Wang X, Davey RA, Chao C, Hellmich MR. Raf-1 kinase inhibitory protein (RKIP) mediates ethanol-induced sensitization of secretagogue signaling in pancreatic acinar cells. J Biol Chem 2012; 287:33377-88. [PMID: 22859298 DOI: 10.1074/jbc.m112.367656] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Excessive alcohol consumption is associated with most cases of chronic pancreatitis, a progressive necrotizing inflammatory disease that can result in pancreatic insufficiency due to acinar atrophy and fibrosis and an increased risk of pancreatic cancer. At a cellular level acute alcohol exposure can sensitize pancreatic acinar cells to secretagogue stimulation, resulting in dysregulation of intracellular Ca(2+) homeostasis and premature digestive enzyme activation; however, the molecular mechanisms by which ethanol exerts these toxic effects have remained undefined. In this study we identify Raf-1 kinase inhibitory protein as an essential mediator of ethanol-induced sensitization of cholecystokinin- and carbachol-regulated Ca(2+) signaling in pancreatic acinar cells. We show that exposure of rodent acinar cells to ethanol induces protein kinase C-dependent Raf-1 kinase inhibitory protein phosphorylation, sensitization of cholecystokinin-stimulated Ca(2+) signaling, and potentiation of both basal and cholecystokinin-stimulated extracellular signal-regulated kinase activation. Furthermore, we show that either suppression of Raf-1 kinase inhibitory protein expression using short hairpin RNA or gene ablation prevented the sensitizing effects of ethanol on cholecystokinin- and carbachol-stimulated Ca(2+) signaling and intracellular chymotrypsin activation in pancreatic acinar cells, suggesting that the modulation of Raf-1 inhibitory protein expression may have future therapeutic utility in the prevention or treatment of alcohol-associated pancreatitis.
Collapse
Affiliation(s)
- Sung Ok Kim
- Department of Surgery, University of Texas Medical Branch, Galveston, Texas 77555-0722, USA
| | | | | | | | | | | |
Collapse
|
13
|
Gukovsky I, Pandol SJ, Mareninova OA, Shalbueva N, Jia W, Gukovskaya AS. Impaired autophagy and organellar dysfunction in pancreatitis. J Gastroenterol Hepatol 2012; 27 Suppl 2:27-32. [PMID: 22320913 PMCID: PMC3281514 DOI: 10.1111/j.1440-1746.2011.07004.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Recent findings from our group, obtained on experimental in vivo and ex vivo models of pancreatitis, reveal that this disease causes a profound dysfunction of key cellular organelles, lysosomes and mitochondria. We found that autophagy, the main cellular degradative, lysosome-driven process, is activated but also impaired in acute pancreatitis because of its' inefficient progression/resolution (flux) resulting from defective function of lysosomes. One mechanism underlying the lysosomal dysfunction in pancreatitis is abnormal processing (maturation) and activation of cathepsins, major lysosomal hydrolases; another is a decrease in pancreatic levels of key lysosomal membrane proteins LAMP-1 and LAMP-2. Our data indicate that lysosomal dysfunction plays an important initiating role in pancreatitis pathobiology. The impaired autophagy mediates vacuole accumulation in acinar cells; furthermore, the abnormal maturation and activation of cathepsins leads to increase in intra-acinar trypsin, the hallmark of pancreatitis; and LAMP-2 deficiency causes inflammation and acinar cell necrosis. Thus, the autophagic and lysosomal dysfunctions mediate key pathologic responses of pancreatitis. On the other hand, we showed that pancreatitis causes acinar cell mitochondria depolarization, mediated by the permeability transition pore (PTP). Genetic (via deletion of cyclophilin D) inactivation of PTP prevents mitochondrial depolarization and greatly ameliorates the pathologic responses of pancreatitis. Further, our data suggest that mitochondrial damage, by stimulating autophagy, increases the demand for efficient lysosomal degradation and therefore aggravates the pathologic consequences of lysosomal dysfunction. Thus, the combined autophagic, lysosomal and mitochondrial dysfunctions are key to the pathogenesis of pancreatitis.
Collapse
Affiliation(s)
- Ilya Gukovsky
- Southern California Research Centers for Alcoholic Liver and Pancreatic Diseases and Cirrhosis, VA Greater Los Angeles Healthcare System, and University of California at Los Angeles, California 90073, USA
| | | | | | | | | | | |
Collapse
|
14
|
Booth DM, Mukherjee R, Sutton R, Criddle DN. Calcium and reactive oxygen species in acute pancreatitis: friend or foe? Antioxid Redox Signal 2011; 15:2683-98. [PMID: 21861696 PMCID: PMC3183657 DOI: 10.1089/ars.2011.3983] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
SIGNIFICANCE Acute pancreatitis (AP) is a debilitating and, at times, lethal inflammatory disease, the causes and progression of which are incompletely understood. Disruption of Ca(2+) homeostasis in response to precipitants of AP leads to loss of mitochondrial integrity and cellular necrosis. RECENT ADVANCES While oxidative stress has been implicated as a major player in the pathogenesis of this disease, its precise roles remain to be defined. Recent developments are challenging the perception of reactive oxygen species (ROS) as nonspecific cytotoxic agents, suggesting that ROS promote apoptosis that may play a vital protective role in cellular stress since necrosis is avoided. CRITICAL ISSUES Fresh clinical findings have indicated that antioxidant treatment does not ameliorate AP and may actually worsen the outcome. This review explores the complex links between cellular Ca(2+) signaling and the intracellular redox environment, with particular relevance to AP. FUTURE DIRECTIONS Recent publications have underlined the importance of both Ca(2+) and ROS within the pathogenesis of AP, particularly in the determination of cell fate. Future research should elucidate the subtle interplay between Ca(2+) and redox mechanisms that operate to modulate mitochondrial function, with a view to devising strategies for the preservation of organellar function.
Collapse
Affiliation(s)
- David M Booth
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, United Kingdom
| | | | | | | |
Collapse
|
15
|
Abstract
PURPOSE OF REVIEW Despite being a subject of much scientific scrutiny, the pathogenesis of acute pancreatitis is still not well understood. This article reviews recent advances in our understanding of acute pancreatitis. RECENT FINDINGS Zymogen activation, observed within acini early during acute pancreatitis for a long time, was shown to be sufficient to induce acute pancreatitis. Another key early event, NFκB activation, has previously been shown to induce acute pancreatitis. The relationship between these two key early steps is beginning to be clarified. Mechanisms of zymogen activation - pathologic calcium signaling, pH changes, colocalization and autophagy, and of NFκB activation have been investigated intensively along with potential therapeutic targets both upstream and downstream of these key events. Additional key findings have been elucidation of the role of bioenergetics and the dual role of oxidative stress in acute pancreatitis, recognition of endoplasmic reticulum stress as an early step and the status of duct cells as important entities in pancreatic injury. SUMMARY Current findings have provided further insight into the roles and mechanisms of zymogen activation and inflammatory pathways in pancreatic injury. Future studies, which will be of great importance in identifying therapeutic targets, are being undertaken to establish the relative contributions of these pathways during acute pancreatitis.
Collapse
|
16
|
Zhang H, Cai CZ, Zhang XQ, Li T, Jia XY, Li BL, Song L, Ma XJ. Breviscapine attenuates acute pancreatitis by inhibiting expression of PKCα and NF-κB in pancreas. World J Gastroenterol 2011; 17:1825-30. [PMID: 21528054 PMCID: PMC3080716 DOI: 10.3748/wjg.v17.i14.1825] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 01/11/2011] [Accepted: 01/18/2011] [Indexed: 02/06/2023] Open
Abstract
AIM: To study the effect of breviscapine (Bre) on activity of protein kinase Cα (PKCα) and nuclear factor (NF)-κB in pancreas, and the mechanism of Bre attenuating acute pancreatitis (AP).
METHODS: One hundred and eight rats were randomly divided into acute necrotizing pancreatitis (ANP) group, Bre group (ANP + Bre group) and sham operation (SO) group, 36 rats in each group. ANP model was induced by a retrograde injection of 4% sodium deoxycholate into the bilio-pancreatic duct. Fifteen minutes after the ANP model was induced, the rats in Bre group were intraperitoneally injected with Bre (0.4 mg/100 g body weight or 0.1 mL/100 g body weight). Survival time and mortality of rats were calculated. Serum amylase and malondialdehyde levels were measured, volume of ascites was recorded and morphology of pancreas and lung was evaluated at 1, 5 and 10 h, after the ANP model was induced, respectively. Expressions of PKCα and subunit p65 of NF-κB in pancreas were detected by immunohistochemistry and Western blotting.
RESULTS: The life span of rats was longer and the mortality was lower in Bre group than in ANP group 13.51 ±5.46 vs 25.36 ± 8.11 (P < 0.05). The amylase and MDA levels as well as the volume of ascites were lower and the pathological changes in pancreas and lung were less in Bre group than ANP group (P < 0.05), indicating that the pancreatitis is less severe in Bre group than ANP group. The activation of PKCα and NF-κB p65 in pancreas was induced rapidly and reached their peak at 1 h or 5 h after ANP, but their activity in Bre group was significantly inhibited.
CONCLUSION: Bre exerts its therapeutic effect on AP by inhibiting the activation of PKCα and NF-κB p65 in pancreas.
Collapse
|
17
|
Ethanol impairs the assembly and disassembly of actin cytoskeleton and cell adhesion via the RhoA signaling pathway, catenin p120 and E-cadherin in CCK-stimulated pancreatic acini. Biochem Biophys Res Commun 2011; 405:558-63. [PMID: 21262198 DOI: 10.1016/j.bbrc.2011.01.067] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Accepted: 01/19/2011] [Indexed: 11/23/2022]
Abstract
The purpose of the present study was to evaluate the effects of EtOH on RhoA, actin cytoskeleton, catenin p120 and E-cadherin and their interactions in CCK-stimulated rat pancreatic acini. In isolated rat pancreatic acinar cells, CCK stimulation enhanced protein expression and association of RhoA, G(α13), Vav-2, catenin p120 and E-cadherin. CCK induced translocation and activation of RhoA and actin-filamentous assembly and disassembly. RhoA was diffusely localized throughout the acinar cell in the resting state and redistributed to the apical site in response to submaximal CCK stimulation and to a lesser extent in response to supramaximal CCK stimulation. Ethanol and subsequent submaximal CCK stimulation mimicked the effect of supramaximal CCK stimulation in terms of amylase secretion and morphologic effects. However, inhibition of RhoA translocation and activation were observed only with ethanol pretreatment. Ethanol followed by supramaximal CCK stimulation disrupted the well-defined localization of catenin p120 and E-cadherin around the lateral plasma membrane. These data suggest that ethanol impaired the assembly and disassembly of actin cytoskeleton and impaired cell-cell adhesion via the RhoA signaling pathways, catenin p120 and E-cadherin in CCK-stimulated pancreatic acini.
Collapse
|
18
|
Binker MG, Binker-Cosen AA, Richards D, Gaisano HY, de Cosen RH, Cosen-Binker LI. Chronic stress sensitizes rats to pancreatitis induced by cerulein: Role of TNF-α. World J Gastroenterol 2010; 16:5565-81. [PMID: 21105189 PMCID: PMC2992674 DOI: 10.3748/wjg.v16.i44.5565] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate chronic stress as a susceptibility factor for developing pancreatitis, as well as tumor necrosis factor-α (TNF-α) as a putative sensitizer.
METHODS: Rat pancreatic acini were used to analyze the influence of TNF-α on submaximal (50 pmol/L) cholecystokinin (CCK) stimulation. Chronic restraint (4 h every day for 21 d) was used to evaluate the effects of submaximal (0.2 μg/kg per hour) cerulein stimulation on chronically stressed rats.
RESULTS: In vitro exposure of pancreatic acini to TNF-α disorganized the actin cytoskeleton. This was further increased by TNF-α/CCK treatment, which additionally reduced amylase secretion, and increased trypsin and nuclear factor-κB activities in a protein-kinase-C δ and ε-dependent manner. TNF-α/CCK also enhanced caspases’ activity and lactate dehydrogenase release, induced ATP loss, and augmented the ADP/ATP ratio. In vivo, rats under chronic restraint exhibited elevated serum and pancreatic TNF-α levels. Serum, pancreatic, and lung inflammatory parameters, as well as caspases’activity in pancreatic and lung tissue, were substantially enhanced in stressed/cerulein-treated rats, which also experienced tissues’ ATP loss and greater ADP/ATP ratios. Histological examination revealed that stressed/cerulein-treated animals developed abundant pancreatic and lung edema, hemorrhage and leukocyte infiltrate, and pancreatic necrosis. Pancreatitis severity was greatly decreased by treating animals with an anti-TNF-α-antibody, which diminished all inflammatory parameters, histopathological scores, and apoptotic/necrotic markers in stressed/cerulein-treated rats.
CONCLUSION: In rats, chronic stress increases susceptibility for developing pancreatitis, which involves TNF-α sensitization of pancreatic acinar cells to undergo injury by physiological cerulein stimulation.
Collapse
|
19
|
Lugea A, Gong J, Nguyen J, Nieto J, French SW, Pandol SJ. Cholinergic mediation of alcohol-induced experimental pancreatitis. Alcohol Clin Exp Res 2010; 34:1768-81. [PMID: 20626730 DOI: 10.1111/j.1530-0277.2010.01264.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVES The mechanisms initiating pancreatitis in patients with chronic alcohol abuse are poorly understood. Although alcohol feeding has been previously suggested to alter cholinergic pathways, the effects of these cholinergic alterations in promoting pancreatitis have not been characterized. For this study, we determined the role of the cholinergic system in ethanol-induced sensitizing effects on cerulein pancreatitis. METHODS Rats were pair-fed control and ethanol-containing Lieber-DeCarli diets for 6 weeks followed by parenteral administration of 4 hourly intraperitoneal injections of the cholecystokinin analog, cerulein at 0.5 μg/kg. This dose of cerulein was selected because it caused pancreatic injury in ethanol-fed but not in control-fed rats. Pancreatitis was preceded by treatment with the muscarinic receptor antagonist atropine or by bilateral subdiaphragmatic vagotomy. Measurement of pancreatic pathology included serum lipase activity, pancreatic trypsin, and caspase-3 activities, and markers of pancreatic necrosis, apoptosis, and autophagy. In addition, we measured the effects of ethanol feeding on pancreatic acetylcholinesterase activity and pancreatic levels of the muscarinic acetylcholine receptors m1 and m3. Finally, we examined the synergistic effects of ethanol and carbachol on inducing acinar cell damage. RESULTS We found that atropine blocked almost completely pancreatic pathology caused by cerulein administration in ethanol-fed rats, while vagotomy was less effective. Ethanol feeding did not alter expression levels of cholinergic muscarinic receptors in the pancreas but significantly decreased pancreatic acetylcholinesterase activity, suggesting that acetylcholine levels and cholinergic input within the pancreas can be higher in ethanol-fed rats. We further found that ethanol treatment of pancreatic acinar cells augmented pancreatic injury responses caused by the cholinergic agonist, carbachol. CONCLUSION These results demonstrate key roles for the cholinergic system in the mechanisms of alcoholic pancreatitis.
Collapse
Affiliation(s)
- Aurelia Lugea
- USC-UCLA Research Center for Alcoholic Liver and Pancreatic Diseases, Veterans Affairs Greater Los Angeles Healthcare System and University of California, Los Angeles, California 90073, USA.
| | | | | | | | | | | |
Collapse
|
20
|
Relationship of strain-dependent susceptibility to experimentally induced acute pancreatitis with regulation of Prss1 and Spink3 expression. J Transl Med 2010; 90:654-64. [PMID: 20157294 DOI: 10.1038/labinvest.2010.44] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
To analyze susceptibility to acute pancreatitis, five mouse strains including Japanese Fancy Mouse 1 (JF1), C57BL/6J, BALB/c, CBA/J, and C3H/HeJ were treated with either a cholecystokinin analog, cerulein, or a choline-deficient, ethionine-supplemented (CDE) diet. The severity of acute pancreatitis induced by cerulein was highest in C3H/HeJ and CBA/J, moderate in BALB/c, and mildest in C57BL/6J and JF1. Basal protein expression levels of the serine protease inhibitor, Kazal type 3 (Spink3) were higher in JF1 and C57BL/6J mice than those of the other three strains under normal feeding conditions. After treatment with cerulein, expression level of Spink3 increased remarkably in JF1 and mildly in C57BL/6J, BALB/c, CBA/J, and C3H/HeJ strains. Increased proteinase, serine, 1 (Prss1) protein expression accompanied by increased trypsin activity with cerulein treatment was observed in susceptible strains such as CBA/J and C3H/HeJ. Similar results were obtained with a CDE diet. In the 3 kb Spink3 promoter region, 92 or 8 nucleotide changes were found in JF1 or C3H vs C57BL/6J, respectively, whereas in the Prss1 promoter region 39 or 46 nucleotide changes were found in JF1 or C3H vs C57BL/6J, respectively. These results suggest that regulation of Prss1 and Spink3 expression is involved in the susceptibility to experimentally induced pancreatitis. The JF1 strain, which is derived from the Japanese wild mouse, will be useful to examine new mechanisms that may not be found in other laboratory mouse strains.
Collapse
|
21
|
Masamune A, Satoh A, Watanabe T, Kikuta K, Satoh M, Suzuki N, Satoh K, Shimosegawa T. Effects of ethanol and its metabolites on human pancreatic stellate cells. Dig Dis Sci 2010; 55:204-11. [PMID: 19165599 DOI: 10.1007/s10620-008-0695-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Accepted: 12/29/2008] [Indexed: 01/03/2023]
Abstract
Pancreatic stellate cells (PSCs) play a pivotal role in pancreatic inflammation and fibrosis. In the pancreas, in addition to oxidative metabolism, ethanol can be metabolized by esterification with fatty acids to form fatty acid ethyl esters such as palmitic acid ethyl ester (PAEE). We here examined the effects of ethanol (at 20 or 50 mM), acetaldehyde (at 200 microM), or PAEE (at 100 microM), on PSCs functions. PSCs did not express mRNAs for pancreatic triglyceride lipase and carboxyl ester lipase. Ethanol and acetaldehyde, but not PAEE, induced production of procollagen type I C-peptide. Ethanol, but not acetaldehyde or PAEE, induced interleukin-8 production. PAEE activated activator protein-1, but not nuclear factor kappaB. In addition, PAEE activated extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38 mitogen-activated protein kinase. Specific activation of signal transduction pathways and cell functions by ethanol and its metabolites may play a role in alcohol-induced pancreatic injury.
Collapse
Affiliation(s)
- Atsushi Masamune
- Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Shah AU, Sarwar A, Orabi AI, Gautam S, Grant WM, Park AJ, Shah AU, Liu J, Mistry PK, Jain D, Husain SZ. Protease activation during in vivo pancreatitis is dependent on calcineurin activation. Am J Physiol Gastrointest Liver Physiol 2009; 297:G967-73. [PMID: 20501444 PMCID: PMC2777459 DOI: 10.1152/ajpgi.00181.2009] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
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.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Jun Liu
- Departments of 1Pediatrics and
| | | | - Dhanpat Jain
- 2Pathology, Yale University School of Medicine, New Haven, Connecticut
| | | |
Collapse
|
23
|
Shi C, Wang X, Zhao X, Andersson R. Cellular and molecular events in acute pancreatitis. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/17471060600776858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
24
|
Wang Y, Yang H, Liu H, Huang J, Song X. Effect of staurosporine on the mobility and invasiveness of lung adenocarcinoma A549 cells: an in vitro study. BMC Cancer 2009; 9:174. [PMID: 19500428 PMCID: PMC2702389 DOI: 10.1186/1471-2407-9-174] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Accepted: 06/08/2009] [Indexed: 12/15/2022] Open
Abstract
Background Lung cancer is one of the most malignant tumors, representing a significant threat to human health. Lung cancer patients often exhibit tumor cell invasion and metastasis before diagnosis which often render current treatments ineffective. Here, we investigated the effect of staurosporine, a potent protein kinase C (PKC) inhibitor on the mobility and invasiveness of human lung adenocarcinoma A549 cells. Methods All experiments were conducted using human lung adenocarcinoma A549 cells that were either untreated or treated with 1 nmol/L, 10 nmol/L, or 100 nmol/L staurosporine. Electron microscopy analyses were performed to study ultrastructural differences between untreated A549 cells and A549 cells treated with staurosporine. The effect of staurosporine on the mobility and invasiveness of A549 was tested using Transwell chambers. Western blot analyses were performed to study the effect of staurosporine on the levels of PKC-α, integrin β1, E-cadherin, and LnR. Changes in MMP-9 and uPA levels were identified by fluorescence microscopy. Results We demonstrated that treatment of A549 cells with staurosporine caused alterations in the cell shape and morphology. Untreated cells were primarily short spindle- and triangle-shaped in contrast to staurosporine treated cells which were retracted and round-shaped. The latter showed signs of apoptosis, including vacuole fragmentation, chromatin degeneration, and a decrease in the number of microvilli at the surface of the cells. The A549 cell adhesion, mobility, and invasiveness significantly decreased with higher staurosporine concentrations. E-cadherin, integrin β1, and LnR levels changed by a factor of 1.5, 0.74, and 0.73, respectively compared to untreated cells. In addition, the levels of MMP-9 and uPA decreased in cells treated with staurosporine. Conclusion In summary, this study demonstrates that staurosporine inhibits cell adhesion, mobility, and invasion of A549 cells. The staurosporine-mediated inhibition of PKC-α, induction of E-Cad expression, and decreased integrin β1, LnR, MMP-9, and uPA levels could all possibly contribute to this biological process. These results represent a significant step forward in the ongoing effort to understand the development of lung carcinoma and to design novel strategies to inhibit metastasis of the tumor by targeting the cell-adhesion, mobility and invasion of tumor cells.
Collapse
Affiliation(s)
- Yanyan Wang
- Department of Pharmacology, The First College of Clinical Medical Science, China Three Gorges University, Yichang, PR China.
| | | | | | | | | |
Collapse
|
25
|
Gerloff A, Singer MV, Feick P. Beer but not wine, hard liquors, or pure ethanol stimulates amylase secretion of rat pancreatic acinar cells in vitro. Alcohol Clin Exp Res 2009; 33:1545-54. [PMID: 19485972 DOI: 10.1111/j.1530-0277.2009.00983.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND In contrast to pure ethanol, the effect of alcoholic beverages on the exocrine pancreas is greatly unknown. Besides ethanol, alcoholic beverages contain numerous nonalcoholic constituents which might have pathophysiological effects on the pancreas. The aim of the present study was to investigate whether some commonly used alcoholic beverages and pure ethanol influence the main function of rat pancreatic acinar cells, i.e., enzyme output in vitro. METHODS Rat pancreatic AR4-2J cells were differentiated by dexamethasone treatment for 72 hours and freshly isolated pancreatic acini were prepared from Sprague-Dawley rats using collagenase digestion. After incubation of cells in the absence or presence of 1 to 10% (v/v) beer (containing 4.7% v/v ethanol), 10% (v/v) wine (containing 10.5 to 12.5% v/v ethanol), 10% (v/v) hard liquor (such as whisky, rum, and gin), or of the corresponding ethanol concentrations (4.03 to 80.6 mM) for 60 minutes, protein secretion was measured using amylase activity assay. RESULTS Incubation of AR4-2J cells with beer caused a dose-dependent stimulation of basal amylase secretion that was significant at doses of beer above 0.5% (v/v). Stimulation with 10% (v/v) beer induced 92.7 +/- 25.2% of maximal amylase release in response to the most effective cholecystokinin (CCK) concentration (100 nM). In contrast, ethanol (up to 80.6 mM) did neither stimulate nor inhibit basal amylase release. Lactate dehydrogenase measurement after treatment of AR4-2J cells with beer for 24 hours indicated that the increase of amylase release was not due to cell membrane damage. Wine and hard liquor had no effect on basal amylase secretion neither diluted to the ethanol concentration of beer nor undiluted. In freshly isolated rat pancreatic acinar cells beer dose-dependently stimulated amylase secretion in a similar manner as in AR4-2J cells. CONCLUSIONS Our data demonstrate that beer dose-dependently increases amylase output. Since neither ethanol nor the other alcoholic beverages tested caused stimulation of amylase release, our findings indicate that nonalcoholic constituents specific for beer are responsible for this increase. These as yet unknown compounds have to be identified and considered in further studies of ethanol-induced pathological and functional changes of the pancreas.
Collapse
Affiliation(s)
- Andreas Gerloff
- Department of Medicine II (Gastroenterology, Hepatology and Infectious Diseases), University Hospital of Heidelberg at Mannheim, Mannheim, Germany
| | | | | |
Collapse
|
26
|
Abstract
Pancreatitis and Calcium Signalling was an international research workshop organized by the authors and held at the Liverpool Medical Institution, Liverpool, United Kingdom, from Sunday 12th to Tuesday 14th November 2006. The overall goal of the workshop was to review progress and explore new opportunities for understanding the mechanisms of acute pancreatitis with an emphasis on the role of pathological calcium signaling. The participants included those with significant interest and expertise in pancreatitis research and others who are in fields outside gastroenterology but with significant expertise in areas of cell biology relevant to pancreatitis. The workshop was designed to enhance interchange of ideas and collaborations, to engage and encourage younger researchers in the field, and promote biomedical research through the participating and supporting organizations and societies. The workshop was divided into 8 topic-oriented sessions. The sessions were: (1) Physiology and pathophysiology of calcium signaling; (2) Interacting signaling mechanisms; (3) Premature digestive enzyme activation; (4) Physiology Society Lecture: Aberrant Ca2+ signaling, bicarbonate secretion, and pancreatitis; (5) NFkappaB, cytokines, and immune mechanisms; (6) Mitochondrial injury; (7) Cell death pathways; and (8) Overview of areas for future research. In each session, speakers presented work appropriate to the topic followed by discussion of the material presented by the group. The publication of these proceedings is intended to provide a platform for enhancing research and therapeutic development for acute pancreatitis.
Collapse
|
27
|
Abstract
Pathological activation of selective signaling molecules within the pancreatic acinar cell mediates the development of acute pancreatitis. Some of the key early acinar cell events include activation of proteases, inhibition of apical secretion, and elaboration of inflammatory mediators. Previous studies have shown that supraphysiological concentrations of cholecystokinin (CCK) that can cause pancreatitis in vivo, also initiate these pathological responses in dispersed groups of acinar cells (acini). Protein kinase C (PKC) regulates many cellular events and a role for this family of signaling molecules has been described in some of the pathological responses of pancreatitis. Notably, ethanol can activate specific PKC isoforms and sensitize the acinar cells to the pathological effects of CCK. Our preliminary studies in isolated pancreatic acini and a cell-free reconstitution system suggest that PKC can mediate protease activation in the acinar cell. These findings may be relevant to the pathogenesis of pancreatitis from alcohol and other etiologies.
Collapse
Affiliation(s)
- Fred Gorelick
- Department of Internal Medicine, Connecticut VA Healthcare, Yale University, West Haven, Connecticut 06516, USA
| | | | | |
Collapse
|
28
|
|
29
|
Husain SZ, Grant WM, Gorelick FS, Nathanson MH, Shah AU. Caerulein-induced intracellular pancreatic zymogen activation is dependent on calcineurin. Am J Physiol Gastrointest Liver Physiol 2007; 292:G1594-9. [PMID: 17332472 DOI: 10.1152/ajpgi.00500.2006] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Aberrant cytosolic Ca(2+) flux in pancreatic acinar cells is critical to the pathological pancreatic zymogen activation observed in acute pancreatitis, but the downstream effectors are not known. In this study, we examined the role of Ca(2+)-activated protein phosphatase 2B (or calcineurin) in zymogen activation. Isolated pancreatic acinar cells were stimulated with supraphysiological caerulein (100 nM) with or without the calcineurin inhibitors FK506 or cell-permeable calcineurin inhibitory peptide (CiP). Chymotrypsin activity was measured as a marker of zymogen activation, and the percent amylase secretion was used as a measure of enzyme secretion. Cytosolic Ca(2+) changes were recorded in acinar cells loaded with the intermediate Ca(2+)-affinity dye fluo-5F using a scanning confocal microscope. A 50% reduction in chymotrypsin activity was observed after pretreatment with 1 microM FK506 or 10 microM CiP. These pretreatments did not affect amylase secretion or the rise in cytosolic Ca(2+) after caerulein stimulation. These findings suggest that calcineurin mediates caerulein-induced intra-acinar zymogen activation but not enzyme secretion or the initial caerulein-induced cytosolic Ca(2+) signal.
Collapse
Affiliation(s)
- Sohail Z Husain
- Dept. of Pediatrics, 333 Cedar St., FMP408, PO Box 208064, New Haven, CT 06520, USA.
| | | | | | | | | |
Collapse
|
30
|
Baumann B, Wagner M, Aleksic T, von Wichert G, Weber CK, Adler G, Wirth T. Constitutive IKK2 activation in acinar cells is sufficient to induce pancreatitis in vivo. J Clin Invest 2007; 117:1502-13. [PMID: 17525799 PMCID: PMC1868787 DOI: 10.1172/jci30876] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Accepted: 03/20/2007] [Indexed: 01/01/2023] Open
Abstract
Activation of the inhibitor of NF-kappaB kinase/NF-kappaB (IKK/NF-kappaB) system and expression of proinflammatory mediators are major events in acute pancreatitis. However, the in vivo consequences of IKK activation on the onset and progression of acute pancreatitis remain unclear. Therefore, we modulated IKK activity conditionally in pancreatic acinar cells. Transgenic mice expressing the reverse tetracycline-responsive transactivator (rtTA) gene under the control of the rat elastase promoter were generated to mediate acinar cell-specific expression of IKK2 alleles. Expression of dominant-negative IKK2 ameliorated cerulein-induced pancreatitis but did not affect activation of trypsin, an initial event in experimental pancreatitis. Notably, expression of constitutively active IKK2 was sufficient to induce acute pancreatitis. This acinar cell-specific phenotype included edema, cellular infiltrates, necrosis, and elevation of serum lipase levels as well as pancreatic fibrosis. IKK2 activation caused increased expression of known NF-kappaB target genes, including mediators of the inflammatory response such as TNF-alpha and ICAM-1. Indeed, inhibition of TNF-alpha activity identified this cytokine as an important effector of IKK2-induced pancreatitis. Our data identify the IKK/NF-kappaB pathway in acinar cells as being key to the development of experimental pancreatitis and the major factor in the inflammatory response typical of this disease.
Collapse
Affiliation(s)
- Bernd Baumann
- Institute of Physiological Chemistry and
Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Martin Wagner
- Institute of Physiological Chemistry and
Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Tamara Aleksic
- Institute of Physiological Chemistry and
Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Götz von Wichert
- Institute of Physiological Chemistry and
Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Christoph K. Weber
- Institute of Physiological Chemistry and
Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Guido Adler
- Institute of Physiological Chemistry and
Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Thomas Wirth
- Institute of Physiological Chemistry and
Department of Internal Medicine I, University of Ulm, Ulm, Germany
| |
Collapse
|
31
|
Cosen-Binker LI, Gaisano HY. Recent insights into the cellular mechanisms of acute pancreatitis. CANADIAN JOURNAL OF GASTROENTEROLOGY = JOURNAL CANADIEN DE GASTROENTEROLOGIE 2007; 21:19-24. [PMID: 17225878 PMCID: PMC2656626 DOI: 10.1155/2007/930424] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In acute pancreatitis, initiating cellular events causing acinar cell injury includes co-localization of zymogens with lysosomal hydrolases, leading to premature enzyme activation and pathological exocytosis of zymogens into the interstitial space. This is followed by processes that accentuate cell injury; triggering acute inflammatory mediators, intensifying oxidative stress, compromising the microcirculation and activating a neurogenic feedback. Such localized events then progress to a systemic inflammatory response leading to multiorgan dysfunction syndrome with resulting high morbidity and mortality. The present review discusses some of the most recent insights into each of these cellular processes postulated to cause or propagate the process of acute pancreatitis, and also the role of alcohol and genetics.
Collapse
Affiliation(s)
| | - Herbert Y Gaisano
- Correspondence: Dr Herbert Y Gaisano, University of Toronto, Room 7226, Medical Science Building, 1 King’s College Circle, Toronto, Ontario M5S 1A8. Telephone 416-978-1526, fax 416-978-8765, e-mail
| |
Collapse
|
32
|
Cosen-Binker LI, Lam PPL, Binker MG, Gaisano HY. Alcohol-induced protein kinase Calpha phosphorylation of Munc18c in carbachol-stimulated acini causes basolateral exocytosis. Gastroenterology 2007; 132:1527-45. [PMID: 17408632 DOI: 10.1053/j.gastro.2007.01.042] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Accepted: 01/04/2007] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Acute or chronic alcohol treatment does little to the exocrine pancreas but predisposes the pancreas to postprandial cholinergic stimulation that triggers cellular events leading to pancreatitis. This alcohol-induced susceptibility mechanism of pancreatitis is unknown. METHODS We employed alcohol-treated dispersed rat pancreatic acini and alcohol diet-fed rats to examine the effects of submaximal carbachol-induced changes in exocytosis (FM1-43 epifluorescence imaging and electron microscopy), Munc18c cellular translocation (confocal microscopy and subcellular fractionation), and protein kinase C (PKC) alpha-induced phosphorylation in relation to pancreatitis. RESULTS Acute low-dose alcohol (20 mmol/L) in vitro exposure or chronic alcohol diet reduces postprandial cholinergic-stimulated amylase secretion from rat pancreatic acinar cells by blocking apical exocytosis and redirecting exocytosis to less efficient basolateral plasma membrane sites. This ectopic exocytosis is mediated by PKCalpha-induced phosphorylation of Munc18c, causing Munc18c displacement from the basolateral plasma membrane into the cytosol in which it undergoes proteolytic degradation; these processes can be blocked by PKCalpha inhibition. CONCLUSIONS We conclude that sequential low-dose alcohol and postprandial cholinergic stimulation can induce PKCalpha-mediated Munc18c plasma membrane displacement. This relieves cognate SNARE proteins on zymogen granules and basolateral membrane to complex and consummate pathologic ectopic exocytosis at the basolateral surface. This change in vesicle trafficking may be related to the pathogenesis of pancreatitis.
Collapse
Affiliation(s)
- Laura I Cosen-Binker
- Department of Medicine, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | | | | | | |
Collapse
|
33
|
Affiliation(s)
- Stephen J Pandol
- Department of Medicine, Department of Veterans Affairs and University of California, Los Angeles, California, USA.
| | | | | | | |
Collapse
|
34
|
Cosen-Binker LI, Lam PPL, Binker MG, Reeve J, Pandol S, Gaisano HY. Alcohol/cholecystokinin-evoked pancreatic acinar basolateral exocytosis is mediated by protein kinase C alpha phosphorylation of Munc18c. J Biol Chem 2007; 282:13047-58. [PMID: 17324928 DOI: 10.1074/jbc.m611132200] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The pancreatic acinus is the functional unit of the exocrine pancreas whose role is to secrete zymogens into the gut lumen for food digestion via apical exocytosis. We previously reported that supramaximal CCK induced apical blockade and redirected exocytosis to ectopic sites on the basolateral plasma membrane (BPM) of this polarized cell, leading to pancreatitis. Basolateral exocytosis was mediated by protein kinase C phosphorylation of BPM Munc18c, causing its displacement into the cytosol and activation of BPM-bound Syntaxin-4 to form a SNARE complex. To mimic the conditions of alcoholic pancreatitis, we now examined whether 20 mm alcohol followed by submaximal CCK might mimic supramaximal CCK in inducing these pathologic exocytotic events. We show that a non-secretory but clinically relevant alcohol concentration (20 mm) inhibited submaximal CCK (50 pM)-stimulated amylase secretion by blocking apical exocytosis and redirecting exocytosis to less efficient BPM, indeed mimicking supramaximal CCK (10 nM) stimulation. We further demonstrate that basolateral exocytosis caused by both stimulation protocols is mediated by PKC alpha-induced phosphorylation of Munc18c: 1) PKC alpha is activated, which binds and induces phosphorylation of PM-Munc18c at a Thr site, and these events can be inhibited by PKC alpha blockade; 2) PKC alpha inhibition blocks Munc18c displacement from the BPM; 3) PKC alpha inhibition prevents basolateral exocytosis but does not rescue apical exocytosis. We conclude that 20 mm alcohol/submaximal CCK as well supramaximal CCK stimulation can trigger pathologic basolateral exocytosis in pancreatic acinar cells via PKC alpha-mediated activation of Munc18c, which enables Syntaxin-4 to become receptive in forming a SNARE complex in the BPM; and we further postulate this to be an underlying mechanism contributing to alcoholic pancreatitis.
Collapse
Affiliation(s)
- Laura I Cosen-Binker
- Department of Medicine, University Health Network, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | | | | | | | | | | |
Collapse
|
35
|
Shi C, Zhao X, Wang X, Zhao L, Andersson R. Potential effects of PKC or protease inhibitors on acute pancreatitis-induced tissue injury in rats. Vascul Pharmacol 2007; 46:406-11. [PMID: 17347056 DOI: 10.1016/j.vph.2007.01.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Accepted: 04/20/2006] [Indexed: 12/20/2022]
Abstract
BACKGROUND Acute pancreatitis (AP) is still one of the severe diseases, that cause the development of multiple organ dysfunction with a high mortality. Effective therapies for AP are still limited, mainly due to unclear mechanisms by which AP initiates both pancreatic and extrapancreatic organ injury. METHODS Protease inhibitors (aprotinin, pefabloc, trypsin inhibitor) and PKC inhibitors (polymyxin B, staurosporine) were administrated 30 min before induction of AP in rats. To investigate the pancreatic, systemic and lung inflammatory response and injury, plasma IL-6 and IL-10, pancreatic and pulmonary myeloperoxidase (MPO) levels, pancreatic protease activity and phospholipase A(2) (PLA(2)) activity in ascites were measured 3 and 6 h after AP induction. RESULTS Pretreatment with protease inhibitors significantly prevented from AP-increased plasma levels of IL-10, pancreatic and pulmonary levels of MPO, pancreatic protease activity and the catalytic activity of PLA(2) in ascites. PKC inhibitors significantly reduced pancreatic and pulmonary levels of MPO and pancreatic protease activity. CONCLUSION Inhibition of proteases in AP may be helpful in ameliorating the inflammatory reaction in both pancreatic and extrapancreatic tissues, where neutrophil involvement may be regulated by PKC and proteases.
Collapse
Affiliation(s)
- Changbin Shi
- Department of Surgery, Clinical Sciences, Lund University Hospital, SE-221 85 Lund, Sweden
| | | | | | | | | |
Collapse
|
36
|
Fortunato F, Berger I, Gross ML, Rieger P, Buechler MW, Werner J. Immune-compromised state in the rat pancreas after chronic alcohol exposure: the role of peroxisome proliferator-activated receptor γ. J Pathol 2007; 213:441-52. [DOI: 10.1002/path.2243] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
37
|
Chowdhury P, Gupta P. Pathophysiology of alcoholic pancreatitis: an overview. World J Gastroenterol 2006; 12:7421-7. [PMID: 17167828 PMCID: PMC4087585 DOI: 10.3748/wjg.v12.i46.7421] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2006] [Revised: 08/16/2006] [Accepted: 08/22/2006] [Indexed: 02/06/2023] Open
Abstract
Use of alcohol is a worldwide habit regardless of socio-economic background. Heavy alcohol consumption is a potential risk factor for induction of pancreatitis. The current review cites the updated literature on the alcohol metabolism, its effects on gastrointestinal and pancreatic function and in causing pancreatic injury, genetic predisposition of alcohol induced pancreatitis. Reports describing prospective mechanisms of action of alcohol activating the signal transduction pathways, induction of oxidative stress parameters through the development of animal models are being presented.
Collapse
Affiliation(s)
- Parimal Chowdhury
- Department of Physiology and Biophysics, College of Medicine, University of Arkansas for Medical Sciences, 4301 W Markham Street, Little Rock, Arkansas 72205, United States.
| | | |
Collapse
|
38
|
Bagby GJ, Zhang P, Purcell JE, Didier PJ, Nelson S. Chronic binge ethanol consumption accelerates progression of simian immunodeficiency virus disease. Alcohol Clin Exp Res 2006; 30:1781-90. [PMID: 17010145 DOI: 10.1111/j.1530-0277.2006.00211.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND While alcohol consumption is known to increase the incidence and severity of infections, the impact of alcohol consumption on human immunodeficiency virus (HIV) disease progression has been difficult to assess. Therefore, we examined the effect of ethanol on simian immunodeficiency virus (SIV) disease progression in a well-defined model utilizing rhesus macaques. METHODS Alcohol was administered for 5 hours via an indwelling intragastric catheter to achieve an alcohol concentration of 50 to 60 mM for 4 consecutive days per week for the duration of the study. Control animals received isocaloric sucrose. After 3 months, animals were inoculated intravenously with 10,000 times the ID(50) of SIV(DeltaB670) and followed to end-stage disease. RESULTS Plasma SIV ribonucleic acid (RNA) was higher in alcohol-consuming animals compared with sucrose-treated animals during the early asymptomatic stage of disease but not at later time points. This increase in viral set point was associated with more rapid progression to end-stage disease in macaques administered alcohol (median=374 days) compared with sucrose (median=900 days). The decline in blood CD4+ cells was similar in both groups of animals. CONCLUSIONS This study indicates that frequent episodes of alcohol intoxication in SIV+ macaques increase viral set point in association with more rapid development of end-stage disease.
Collapse
Affiliation(s)
- Gregory J Bagby
- Department of Physiology, LSU Health Sciences Center, New Orleans, Louisiana 70112-1393, USA.
| | | | | | | | | |
Collapse
|
39
|
Abstract
Alcohol-associated acute and chronic pancreatitis occur in a minority of alcohol users, suggesting that most drinkers are protected from pancreatic diseases while a subset is susceptible. Ongoing studies suggest that the pathophysiology is complex and can involve multiple genetic and environmental pathways and stochastic events. Both rat models and human genetic epidemiology studies have been used to understand susceptibility and modifying factors in humans. Rat studies suggest that different types of altered pancreatic physiology occur depending on dose, they occur rapidly and that alcohol changes the immune response to recurrent pancreatic injury. Human studies suggest that PRSS1 and SPINK1 mutation increase the pancreas' susceptibility to alcohol-associated pancreatitis, and that tobacco smoking, and some factors, affect disease progression.
Collapse
Affiliation(s)
- David C Whitcomb
- Division of Gastroenterology, Department of Medicine, University of Pittsburgh, and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15213, USA.
| |
Collapse
|
40
|
Satoh A, Gukovskaya AS, Reeve JR, Shimosegawa T, Pandol SJ. Ethanol sensitizes NF-kappaB activation in pancreatic acinar cells through effects on protein kinase C-epsilon. Am J Physiol Gastrointest Liver Physiol 2006; 291:G432-8. [PMID: 16574982 DOI: 10.1152/ajpgi.00579.2005] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Although ethanol abuse is the most common cause of pancreatitis, the mechanism of alcohol's effect on the pancreas is not well understood. Previously, we demonstrated that in vitro ethanol treatment of pancreatic acinar cells augmented the CCK-8-induced activation of NF-kappaB, a key signaling system involved in the inflammatory response of pancreatitis. In the present study, we determine the role for individual PKC isoforms in the sensitizing effect of ethanol on NF-kappaB activation. Dispersed rat pancreatic acini were treated with and without ethanol and then stimulated with CCK-8; 100 nM CCK-8 caused both NF-kappaB and PKC-delta, -epsilon, and -zeta activation, whereas 0.1 nM CCK-8 did not increase PKC-epsilon, PKC-zeta, or NF-kappaB activity. CCK-8 (0.1 nM) did activate PKC-delta. PKC-epsilon activator alone did not cause NF-kappaB activation; however, together with 0.1 nM CCK-8, it caused NF-kappaB activation. Ethanol activated PKC-epsilon without affecting other PKC isoforms or NF-kappaB activity. Of note, stimulation of acini with ethanol and 0.1 nM CCK-8 resulted in the activation of PKC-delta, PKC-epsilon, and NF-kappaB. The NF-kappaB activation to 0.1 nM CCK-8 in ethanol-pretreated acini was inhibited by both PKC-delta inhibitor and PKC-epsilon inhibitor. Taken together, these results demonstrate the different modes of activation of PKC isoforms and NF-kappaB in acini stimulated with ethanol, high-dose CCK-8, and low-dose CCK-8, and furthermore suggest that activation of both PKC-epsilon and -delta is required for NF-kappaB activation. These results suggest that ethanol enhances the CCK-8-induced NF-kappaB activation at least in part through its effects on PKC-epsilon.
Collapse
Affiliation(s)
- Akihiko Satoh
- VA Greater L.A. Healthcare System, West L.A. Healthcare Center, Bldg. 258, Rm. 340, 11301 Wilshire Blvd., Los Angeles, CA 90073, USA.
| | | | | | | | | |
Collapse
|
41
|
Saluja A, Dudeja V, Phillips P. Inflammation and pain in pancreatic disorders: summary of the symposium sponsored by the American Pancreatic Association and the National Pancreas Foundation (Chicago, November 4-5, 2005). Pancreas 2006; 33:184-91. [PMID: 16868485 DOI: 10.1097/01.mpa.0000233122.22016.e0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Affiliation(s)
- Ashok Saluja
- University of Massachusetts Medical School, Department of Surgery, Worcester, MA 01605, USA.
| | | | | |
Collapse
|
42
|
Abstract
OBJECTIVES Alcohol abuse is a major cause of pancreatitis, which is associated with death of parenchymal cells. The goal of this study was to explore the effects of ethanol on cell death pathways in the pancreas. METHODS Adult male Wistar rats were fed with ethanol diets using the Lieber-DeCarli method. Caspase-8, caspase-3, and cathepsin B expression and activity in the pancreas of these animals as well as the signals that regulate their expression were studied using Western blot analysis and specific assays for biochemical enzyme activity. RESULTS In the pancreas from rats fed with ethanol, the protein expression and activity of caspase-8 decreased by 48% and 45%, respectively, and caspase-3 activity decreased by 39%. In contrast, cathepsin B protein expression and activity increased with ethanol feeding by 189% and 143%, respectively. Evaluation of the transcriptional regulatory system for caspase-8 and cathepsin B showed that the ethanol effects on these pathways were largely transcriptional. CONCLUSIONS Our findings show effects of ethanol on the expression of several signals involved in cell death in the pancreas through alteration of transcriptional regulators. The decrease in caspase expression and increase in cathepsin B expression indicate that ethanol feeding may prevent apoptosis and promote necrosis of pancreatic tissue with stresses that cause pancreatitis.
Collapse
Affiliation(s)
- Yan-Ling Wang
- USC-UCLA Research Center for Alcohol Liver and Pancreatic Diseases, University of California, Los Angeles, USA
| | | | | | | | | | | | | |
Collapse
|
43
|
Felderbauer P, Müller C, Bulut K, Belyaev O, Schmitz F, Uhl W, Schmidt WE. Pathophysiology and treatment of acute pancreatitis: new therapeutic targets--a ray of hope? Basic Clin Pharmacol Toxicol 2006; 97:342-50. [PMID: 16364048 DOI: 10.1111/j.1742-7843.2005.pto_274.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Acute pancreatitis is a life-threatening disease with putatively high mortality rates, particularly in the setting of systemic inflammatory response and multiple organ failure when superinfection of necrosis occurs. Although the APACHE II and Ranson score are widely accepted as clinical scores to predict the prognosis, current medical treatment is still based upon state of the art intensive care treatment largely unrelated to the pathogenesis of the disease. The mechanisms by which premature enzyme activation and autodigestion of the pancreatic gland is triggered and maintained are still ill-defined. It is well known that activation of chemokines, cytokines and pancreatic enzymes characterize the cause of the disease, but disease-phase specific treatment attempts have thus far not resulted in successful molecular based medical treatments. The current summary describes the novel understanding in the pathophysiology of acute pancreatitis with special emphasis on specific disease phases. It outlines promising and novel experimental and medical therapeutic approaches which might become clinical targets and successful strategies to significantly reduce pancreatitis-associated mortality rates.
Collapse
Affiliation(s)
- Peter Felderbauer
- Department of Internal Medicine I, St. Josef-Hospital, Ruhr University, Bochum, Germany.
| | | | | | | | | | | | | |
Collapse
|
44
|
Apte MV, Zima T, Dooley S, Siegmund SV, Pandol SJ, Singer MV. Signal transduction in alcohol-related diseases. Alcohol Clin Exp Res 2006; 29:1299-1309. [PMID: 16088992 DOI: 10.1097/01.alc.0000171893.14163.07] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Minoti V Apte
- Pancreatic Research Group, The University of New South Wales, Sydney, Australia
| | | | | | | | | | | |
Collapse
|
45
|
Petersen OH, Sutton R. Ca2+ signalling and pancreatitis: effects of alcohol, bile and coffee. Trends Pharmacol Sci 2006; 27:113-20. [PMID: 16406087 DOI: 10.1016/j.tips.2005.12.006] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2005] [Revised: 11/09/2005] [Accepted: 12/15/2005] [Indexed: 01/11/2023]
Abstract
Ca2+ is a universal intracellular messenger that controls a wide range of cellular processes. In pancreatic acinar cells, acetylcholine and cholecystokinin regulate secretion via generation of repetitive local cytosolic Ca2+ signals in the apical pole. Bile acids and non-oxidative alcohol metabolites can elicit abnormal cytosolic Ca2+ signals that are global and sustained and result in necrosis. Necrosis results from excessive loss of Ca2+ from the endoplasmic reticulum, which is mediated by Ca2+ release through specific channels and inhibition of Ca2+ pumps in intracellular stores, followed by entry of extracellular Ca2+. Reduction of the cellular ATP level has a major role in this process. These abnormal Ca2+ signals, which can be inhibited by caffeine, explain how excessive alcohol intake and biliary disease cause acute pancreatitis, an often-fatal human disease in which the pancreas digests itself and its surroundings.
Collapse
Affiliation(s)
- Ole H Petersen
- MRC Group, Physiological Laboratory and Division of Surgery and Oncology, University of Liverpool, Liverpool L69 3BX, UK.
| | | |
Collapse
|
46
|
Abstract
PURPOSE OF REVIEW As in our previous reviews, we endeavor to review important new observations in chronic pancreatitis made in the past year. We included articles, including review articles, only if they contained new observations or readdressed old questions and provided new insights into old and new concepts. RECENT FINDINGS Important observations include the following: (1) Strong association between cystic fibrosis transmembrane regulator dysfunction/mutations and 'recurrent acute pancreatitis', particularly in patients with pancreas divisum (2) Pancreas divisum may be incidental finding in recurrent acute pancreatitis (3) Smoking increases risk of chronic pancreatitis (4) Coxsackie B virus may increase severity of alcoholic chronic pancreatitis (5) CD4+ T cells and an immune reaction against amylase may play a role in pathogenesis of autoimmune pancreatitis (6) 2-(18F)-Fluro-2-deoxy-D-glucose positron emission tomography might be useful to detect pancreatic cancer in chronic pancreatitis patients at risk for developing pancreatic cancer, but contrast-enhanced Doppler ultrasound or endosonography may be as sensitive and better than contrast enhanced computed tomography (7) Superiority of surgery vs endotherapy for long term pain relief and weight gain in painful chronic pancreatitis (8) Early treatment of pain and malabsorption may improve life quality (9) Antifibrogenesis and fibrolytic agents as potential therapies. SUMMARY Ongoing basic and clinical research this past year has further characterized genetic, molecular and clinical aspects of chronic pancreatitis. The advent of predictable and lasting treatments of chronic pancreatitis is most likely to appear on the wings of carefully conducted studies targeting genetic and molecular mechanisms of chronic pancreatitis, particularly pancreatic fibrogenesis.
Collapse
Affiliation(s)
- Matthew J DiMagno
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109-0362, USA.
| | | |
Collapse
|
47
|
Affiliation(s)
- John F Di Mari
- Department of Internal Medicine, University of Texas Medical Branch, Galveston 77555-1064, USA.
| | | | | |
Collapse
|
48
|
Go VLW, Gukovskaya A, Pandol SJ. Alcohol and pancreatic cancer. Alcohol 2005; 35:205-11. [PMID: 16054982 DOI: 10.1016/j.alcohol.2005.03.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2005] [Revised: 03/18/2005] [Accepted: 03/25/2005] [Indexed: 12/13/2022]
Abstract
Findings obtained from numerous prospective cohort and case-control studies on alcohol consumption and pancreatic cancer risk have been inconsistent, with many confounding variables present in various investigations. However, heavy alcohol consumption has been known to be a major cause of chronic pancreatitis and a risk factor for type 2 diabetes mellitus, both of which are linked to pancreatic cancer. It has been established that an extensive normal interaction exists between the exocrine and endocrine pancreas, as well as in inflammatory processes and carcinogenesis. Alcohol and its metabolites (acetaldehyde and fatty acid ethyl esters) can alter metabolic pathways involved in the inflammatory response and carcinogenesis, and they are mediated by one or more of the following mechanisms: (1) premature activation of zymogens; (2) induction of the inflammatory response through activation of nuclear transcription factors, including nuclear factor-kappa and activation protein 1; (3) increased production of reactive oxygen species, resulting in oxidative DNA damage and altered effect of dietary antioxidants; (4) activation of pancreatic stellate cells, which leads to fibrosis; (5) gene mutation in enzymes related to cytochrome P450, glutathione S-transferase, aldehyde dehydrogenase, cationic trypsinogen, and pancreatic secretory trypsin inhibitor; (6) synergistic effects of ethanol and tobacco carcinogen on NNK [nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone] metabolism; and (7) dysregulation of proliferation and apoptosis. These various metabolic effects of alcohol can lead to or interact with other risk factors (genetic, dietary, environmental, and lifestyle factors) that result in acute and chronic pancreatitis and diabetes mellitus and, ultimately, affect the multistep process of carcinogenesis toward the development of pancreatic cancer.
Collapse
Affiliation(s)
- Vay Liang W Go
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | | | | |
Collapse
|
49
|
Abstract
Alcoholic pancreatitis is a major complication of alcohol abuse. Since only a minority of alcoholics develop pancreatitis, there has been a keen interest in identifying the factors that may confer individual susceptibility to the disease. Numerous possibilities have been evaluated including diet, drinking patterns and a range of inherited factors. However, at the present time, no susceptibility factor has been unequivocally identified. In contrast, considerable progress has been made with respect to the constant effects of alcohol on the pancreas. The molecular mechanisms of alcohol-induced pancreatic injury are being increasingly defined with an emphasis, in recent years, on the acinar cell itself as the principal site on ethanol-related damage. It has now been established that the acinar cell is capable of metabolizing alcohol and that the direct toxic effects of alcohol and/or its metabolites on acinar cells may predispose the gland to autodigestive injury in the presence of an appropriate triggering factor. A significant recent development relates to the characterization of pancreatic stellate cells, increasingly implicated in alcoholic pancreatic fibrosis. Here the current concepts regarding the mechanisms/pathways mediating alcohol-induced pancreatic injury are outlined.
Collapse
Affiliation(s)
- M V Apte
- Pancreatic Research Group, University of New South Wales, Sydney, Australia.
| | | | | |
Collapse
|
50
|
Fischer L, Gukovskaya AS, Young SH, Gukovsky I, Lugea A, Buechler P, Penninger JM, Friess H, Pandol SJ. Phosphatidylinositol 3-kinase regulates Ca2+ signaling in pancreatic acinar cells through inhibition of sarco(endo)plasmic reticulum Ca2+-ATPase. Am J Physiol Gastrointest Liver Physiol 2004; 287:G1200-12. [PMID: 15271649 DOI: 10.1152/ajpgi.00212.2004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Calcium is a key mediator of hormone-induced enzyme secretion in pancreatic acinar cells. At the same time, abnormal Ca(2+) responses are associated with pancreatitis. We have recently shown that inhibition of phosphatidylinositol 3-kinase (PI3-kinase) by LY-294002 and wortmannin, as well as genetic deletion of PI3-kinase-gamma, regulates Ca(2+) responses and the Ca(2+)-sensitive trypsinogen activation in pancreatic acinar cells. The present study sought to determine the mechanisms of PI3-kinase involvement in Ca(2+) responses induced in these cells by CCK and carbachol. The PI3-kinase inhibitors inhibited both Ca(2+) influx and mobilization from intracellular stores induced by stimulation of acini with physiological and pathological concentrations of CCK, as well as with carbachol. PI3-kinase inhibition facilitated the decay of cytosolic free Ca(2+) concentration ([Ca(2+)](i)) oscillations observed in individual acinar cells. The PI3-kinase inhibitors decreased neither CCK-induced inositol 1,4,5-trisphosphate [Ins(1,4,5)P(3)] production nor Ins(1,4,5)P(3)-induced Ca(2+) mobilization, suggesting that the effect of PI3-kinase inhibition is not through Ins(1,4,5)P(3) or Ins(1,4,5)P(3) receptors. PI3-kinase inhibition did not affect Ca(2+) mobilization induced by thapsigargin, a specific inhibitor of sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA). Moreover, SERCA blockade with thapsigargin abolished the effects of pharmacological and genetic PI3-kinase inhibition on [Ca(2+)](i) signals, suggesting SERCA as a downstream target of PI3-kinase. Both pharmacological PI3-kinase inhibition and genetic deletion of PI3-kinase-gamma increased the amount of Ca(2+) in intracellular stores during CCK stimulation. Finally, addition of the PI3-kinase product phosphatidylinositol 3,4,5-trisphosphate to permeabilized acini significantly attenuated Ca(2+) reloading into the endoplasmic reticulum. The results indicate that PI3-kinase regulates Ca(2+) signaling in pancreatic acinar cells through its inhibitory effect on SERCA.
Collapse
Affiliation(s)
- L Fischer
- Veterans Affairs Greater Los Angeles Healthcare System, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90073, USA
| | | | | | | | | | | | | | | | | |
Collapse
|