1
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Sugawara Y, Mizuno Y, Oku S, Sawada Y, Goto T. Role of protein kinase D1 in vasoconstriction and haemodynamics in rats. Microvasc Res 2024; 152:104627. [PMID: 37963515 DOI: 10.1016/j.mvr.2023.104627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 10/31/2023] [Accepted: 11/06/2023] [Indexed: 11/16/2023]
Abstract
AIMS Protein kinase D (PKD), once considered an effector of protein kinase C (PKC), now plays many pathophysiological roles in various tissues. However, little is known about role of PKD in vascular function. We investigated the role of PKD in contraction of rat aorta and human aortic smooth muscle cells (HASMCs) and in haemodynamics in rats. METHODS AND RESULTS Isometric tension of rat aortic was measured to examine norepinephrine-induced contraction in the presence of PKD, PKC and Rho-kinase inhibitors. Phosphorylation of PKD1, myosin targeting subunit-1 (MYPT1), myosin light chain (MLC), CPI-17 and heat-shock protein 27 (HSP27), and actin polymerization were measured in the aorta. Phosphorylation of MYPT1 and MLC was also measured in HASMCs knocked down with specific siRNAs of PKD 1, 2 and 3. Intracellular calcium concentrations and cell shortening were measured in HASMCs. Norepinephrine-induced aortic contraction was accompanied by increased phosphorylation of PKD1, MYPT1 and MLC and actin polymerization, all of which were attenuated with PKD inhibitor CRT0066101. PKD1 phosphorylation was not inhibited by PKC inhibitor, chelerythrine or Rho kinase inhibitor, fasudil. In HASMCs, the phosphorylation of MYPT1 and MLC was attenuated by PKD1, but not PKD2, 3 knockdown. In HASMCs, CRT0066101 inhibited norepinephrine-induced cell shortening without affecting calcium concentration. Administration of CRT0066101 decreased systemic vascular resistance and blood pressure without affecting cardiac output in rats. CONCLUSIONS PKD1 may play roles in aorta contraction and haemodynamics via phosphorylation of MYPT1 and actin polymerization in a calcium-independent manner.
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Affiliation(s)
- Yoh Sugawara
- Department of Anaesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yusuke Mizuno
- Department of Anaesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
| | - Shinya Oku
- Department of Anaesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yuri Sawada
- Department of Anaesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Takahisa Goto
- Department of Anaesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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2
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Fleming Martinez AK, Storz P. Protein kinase D1 - A targetable mediator of pancreatic cancer development. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119646. [PMID: 38061566 PMCID: PMC10872883 DOI: 10.1016/j.bbamcr.2023.119646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 10/17/2023] [Accepted: 11/30/2023] [Indexed: 01/14/2024]
Abstract
Members of the Protein kinase D (PKD) kinase family each play important cell-specific roles in the regulation of normal pancreas functions. In pancreatic diseases PKD1 is the most widely characterized isoform with roles in pancreatitis and in induction of pancreatic cancer and its progression. PKD1 expression and activation increases in pancreatic acinar cells through macrophage secreted factors, Kirsten rat sarcoma viral oncogene homolog (KRAS) signaling, and reactive oxygen species (ROS), driving the formation of precancerous lesions. In precancerous lesions PKD1 regulates cell survival, growth, senescence, and generation of doublecortin like kinase 1 (DCLK1)-positive cancer stem cells (CSCs). Within tumors, regulation by PKD1 includes chemoresistance, apoptosis, proliferation, CSC features, and the Warburg effect. Thus, PKD1 plays a critical role throughout pancreatic disease initiation and progression.
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Affiliation(s)
| | - Peter Storz
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, USA.
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3
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Ramos-Alvarez I, Lee L, Jensen RT. Cofilin activation in pancreatic acinar cells plays a pivotal convergent role for mediating CCK-stimulated enzyme secretion and growth. Front Physiol 2023; 14:1147572. [PMID: 37138671 PMCID: PMC10149936 DOI: 10.3389/fphys.2023.1147572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 04/05/2023] [Indexed: 05/05/2023] Open
Abstract
Introduction: The actin regulatory protein, cofilin plays a key signaling role in many cells for numerous cellular responses including in proliferation, development, motility, migration, secretion and growth. In the pancreas it is important in islet insulin secretion, growth of pancreatic cancer cells and in pancreatitis. However, there are no studies on its role or activation in pancreatic acinar cells. Methods: To address this question, we studied the ability of CCK to activate cofilin in pancreatic acinar cells, AR42J cells and CCK1-R transfected Panc-1 cells, the signaling cascades involved and its effect on enzyme secretion and MAPK activation, a key mediator of pancreatic growth. Results: CCK (0.3 and 100 nM), TPA, carbachol, Bombesin, secretin and VIP decreased phospho-cofilin (i.e., activate cofilin) and both phospho-kinetic and inhibitor studies of cofilin, LIM kinase (LIMK) and Slingshot Protein Phosphatase (SSH1) demonstrated these conventional activators of cofilin were not involved. Serine phosphatases inhibitors (calyculin A and okadaic acid), however inhibited CCK/TPA-cofilin activation. Studies of various CCK-activated signaling cascades showed activation of PKC/PKD, Src, PAK4, JNK, ROCK mediated cofilin activation, but not PI3K, p38, or MEK. Furthermore, using both siRNA and cofilin inhibitors, cofilin activation was shown to be essential for CCK-mediated enzyme secretion and MAPK activation. Conclusion: These results support the conclusion that cofilin activation plays a pivotal convergent role for various cell signaling cascades in CCK mediated growth/enzyme secretion in pancreatic acini.
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Affiliation(s)
- Irene Ramos-Alvarez
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Lingaku Lee
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
- National Kyushu Cancer Center, Department of Hepato-Biliary-Pancreatology, Fukuoka, Japan
| | - Robert T. Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
- *Correspondence: Robert T. Jensen,
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4
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Yuan J, Chheda C, Tan G, Elmadbouh O, Pandol SJ. Protein kinase D: A therapeutic target in experimental alcoholic pancreatitis. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166486. [PMID: 35835415 PMCID: PMC9481726 DOI: 10.1016/j.bbadis.2022.166486] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 06/24/2022] [Accepted: 07/06/2022] [Indexed: 12/18/2022]
Abstract
BACKGROUND Alcohol abuse, a main cause of pancreatitis, has been known to augment NF-κB activation and cell necrosis in pancreatitis. However, the underlying mechanisms are unclear. We recently reported that inhibition of protein kinase D (PKD) alleviated NF-κB activation and severity of experimental pancreatitis. Here we investigated whether PKD signaling mediated the modulatory effects of alcohol abuse on pathological responses in alcoholic pancreatitis. METHODS Alcoholic pancreatitis was provoked in two rodent models with pair-feeding control and ethanol-containing Lieber-DeCarli diets for up to 8 weeks followed by up to 7 hourly intraperitoneal injections of cerulein at 1 μg/kg (rats) or 3 μg/kg (mice). Effects of PKD inhibition by PKD inhibitors or genetic deletion of pancreatic PKD isoform (PKD3Δpanc mice) on alcoholic pancreatitis parameters were determined. RESULTS Ethanol administration amplified PKD signaling by promoting expression and activation of pancreatic PKD, resulted in augmented/promoted pancreatitis responses. Pharmacological inhibition of PKD or with PKD3Δpanc mice prevented the augmenting/sensitizing effect of ethanol on NF-κB activation and inflammatory responses, cell necrotic death and the severity of disease in alcoholic pancreatitis. PKD inhibition prevented alcohol-enhanced trypsinogen activation, mRNA expression of multiple inflammatory molecules, the receptor-interacting protein kinase activation, ATP depletion, and downregulation of pro-survival Bcl-2 protein in alcoholic pancreatitis. Furthermore, PKD inhibitor CID755673 or CRT0066101, administrated after the induction of pancreatitis in mouse and rat alcoholic pancreatitis models, significantly mitigated the severity of pancreatitis. CONCLUSION PKD mediates effect of alcohol abuse on pathological process of pancreatitis and constitutes a novel therapeutic target to treat this disease.
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Affiliation(s)
- Jingzhen Yuan
- Cedars-Sinai Medical Center, Los Angeles, CA, USA; Veterans Affairs Greater Los Angeles Healthcare System, University of California at Los Angeles and South California Research Center for Alcoholic Liver and Pancreatic Diseases, California, USA.
| | | | - Grace Tan
- Veterans Affairs Greater Los Angeles Healthcare System, University of California at Los Angeles and South California Research Center for Alcoholic Liver and Pancreatic Diseases, California, USA; Loma Linda Medical School, Los Angeles, CA, USA
| | | | - Stephen J Pandol
- Cedars-Sinai Medical Center, Los Angeles, CA, USA; Veterans Affairs Greater Los Angeles Healthcare System, University of California at Los Angeles and South California Research Center for Alcoholic Liver and Pancreatic Diseases, California, USA
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5
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Yuan J, Chheda C, Piplani H, Geng M, Tan G, Thakur R, Pandol SJ. Pancreas-specific deletion of protein kinase D attenuates inflammation, necrosis, and severity of acute pancreatitis. Biochim Biophys Acta Mol Basis Dis 2020; 1867:165987. [PMID: 33039594 DOI: 10.1016/j.bbadis.2020.165987] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 10/01/2020] [Accepted: 10/05/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Protein kinase D (PKD) family, which includes PKD/PKD1, PKD2, and PKD3, has been increasingly implicated in the regulation of multiple cellular functions and human diseases. We recently reported that pharmacologic inhibition of PKD ameliorated the pathologic responses and severity of pancreatitis. However, to further investigate the importance of PKD family members in pancreatitis, it is necessary to explore the effects of pancreas-specific genetic inhibition of PKD isoform on pathology of pancreatitis. METHODS We generated a mouse model (referred as PKD3Δpanc mice) with pancreas-specific deletion of PKD3, the predominant PKD isoform in mouse pancreatic acinar cells, by crossing Pkd3flox/flox mice with Pdx1-Cre transgenic mice which express Cre recombinase under the control of the mouse Pdx1 promoter. Pancreas-specific deletion of the PKD3 gene and PKD3 protein was confirmed by PCR and Western blot analysis. Experimental pancreatitis was induced in PKD3Δpanc and Pkd3flox/flox (control mice) littermates by intraperitoneal injections of cerulein or L-arginine. RESULTS Compared to the control mice, PKD3Δpanc mice displayed significant attenuation in inflammation, necrosis, and severity of pancreatitis in both experimental models. PKD3Δpanc mice had markedly decreased NF-κB and trypsinogen activation, pancreatic mRNA expression of multiple inflammatory molecules, and the receptor-interacting protein kinase 1 (RIP1) activation in pancreatitis. PKD3Δpanc mice also had less pancreatic ATP depletion, increased pro-survival Bcl-2 family protein expression, and autophagy promotion. CONCLUSION With PKD3Δpanc mouse model, we further demonstrated that PKD plays a critical role in pathobiological process of pancreatitis and PKD constitutes a novel therapeutic target to treat this disorder.
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Affiliation(s)
- Jingzhen Yuan
- Cedars-Sinai Medical Center, Los Angeles, CA, USA; Veterans Affairs Greater Los Angeles Healthcare System, University of California at Los Angeles, South California Research Center for Alcoholic Liver and Pancreatic Diseases, California, USA.
| | | | | | - Meng Geng
- Veterans Affairs Greater Los Angeles Healthcare System, University of California at Los Angeles, South California Research Center for Alcoholic Liver and Pancreatic Diseases, California, USA; Frank Netter H. School of Medicine at Quinnipiac University, CT, USA
| | - Grace Tan
- Veterans Affairs Greater Los Angeles Healthcare System, University of California at Los Angeles, South California Research Center for Alcoholic Liver and Pancreatic Diseases, California, USA; Loma Linda Medical School, Los Angeles, CA, United States of America
| | - Reetu Thakur
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Stephen J Pandol
- Cedars-Sinai Medical Center, Los Angeles, CA, USA; Veterans Affairs Greater Los Angeles Healthcare System, University of California at Los Angeles, South California Research Center for Alcoholic Liver and Pancreatic Diseases, California, USA
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6
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Merzoug-Larabi M, Youssef I, Bui AT, Legay C, Loiodice S, Lognon S, Babajko S, Ricort JM. Protein Kinase D1 (PKD1) Is a New Functional Non-Genomic Target of Bisphenol A in Breast Cancer Cells. Front Pharmacol 2020; 10:1683. [PMID: 32082170 PMCID: PMC7006487 DOI: 10.3389/fphar.2019.01683] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 12/24/2019] [Indexed: 01/01/2023] Open
Abstract
Exposure to bisphenol A (BPA), one of the most widespread endocrine disruptors present in our environment, has been associated with the recent increased prevalence and severity of several diseases such as diabetes, obesity, autism, reproductive and neurological defects, oral diseases, and cancers such as breast tumors. BPA is suspected to act through genomic and non-genomic pathways. However, its precise molecular mechanisms are still largely unknown. Our goal was to identify and characterize a new molecular target of BPA in breast cancer cells in order to better understand how this compound may affect breast tumor growth and development. By using in vitro (MCF-7, T47D, Hs578t, and MDA-MB231 cell lines) and in vivo models, we demonstrated that PKD1 is a functional non-genomic target of BPA. PKD1 specifically mediates BPA-induced cell proliferation, clonogenicity, and anchorage-independent growth of breast tumor cells. Additionally, low-doses of BPA (≤10- 8 M) induced the phosphorylation of PKD1, a key signature of its activation state. Moreover, PKD1 overexpression increased the growth of BPA-exposed breast tumor xenografts in vivo in athymic female Swiss nude (Foxn1nu/nu ) mice. These findings further our understanding of the molecular mechanisms of BPA. By defining PKD1 as a functional target of BPA in breast cancer cell proliferation and tumor development, they provide new insights into the pathogenesis related to the exposure to BPA and other endocrine disruptors acting similarly.
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Affiliation(s)
- Messaouda Merzoug-Larabi
- Centre National de la Recherche Scientifique, CNRS UMR_8113, Laboratoire de Biologie et Pharmacologie Appliquée, Cachan, France.,École Normale Supérieure Paris-Saclay, Université Paris-Saclay, Cachan, France
| | - Ilige Youssef
- Centre National de la Recherche Scientifique, CNRS UMR_8113, Laboratoire de Biologie et Pharmacologie Appliquée, Cachan, France.,École Normale Supérieure Paris-Saclay, Université Paris-Saclay, Cachan, France
| | - Ai Thu Bui
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Laboratoire de Physiopathologie Orale Moléculaire, Paris, France
| | - Christine Legay
- Centre National de la Recherche Scientifique, CNRS UMR_8113, Laboratoire de Biologie et Pharmacologie Appliquée, Cachan, France.,École Normale Supérieure Paris-Saclay, Université Paris-Saclay, Cachan, France
| | - Sophia Loiodice
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Laboratoire de Physiopathologie Orale Moléculaire, Paris, France
| | - Sophie Lognon
- École Normale Supérieure Paris-Saclay, Université Paris-Saclay, Cachan, France
| | - Sylvie Babajko
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Laboratoire de Physiopathologie Orale Moléculaire, Paris, France
| | - Jean-Marc Ricort
- Centre National de la Recherche Scientifique, CNRS UMR_8113, Laboratoire de Biologie et Pharmacologie Appliquée, Cachan, France.,École Normale Supérieure Paris-Saclay, Université Paris-Saclay, Cachan, France
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7
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Youssef I, Ricort JM. Deciphering the Role of Protein Kinase D1 (PKD1) in Cellular Proliferation. Mol Cancer Res 2019; 17:1961-1974. [PMID: 31311827 DOI: 10.1158/1541-7786.mcr-19-0125] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 06/05/2019] [Accepted: 07/11/2019] [Indexed: 11/16/2022]
Abstract
Protein kinase D1 (PKD1) is a serine/threonine kinase that belongs to the calcium/calmodulin-dependent kinase family, and is involved in multiple mechanisms implicated in tumor progression such as cell motility, invasion, proliferation, protein transport, and apoptosis. While it is expressed in most tissues in the normal state, PKD1 expression may increase or decrease during tumorigenesis, and its role in proliferation is context-dependent and poorly understood. In this review, we present and discuss the current landscape of studies investigating the role of PKD1 in the proliferation of both cancerous and normal cells. Indeed, as a potential therapeutic target, deciphering whether PKD1 exerts a pro- or antiproliferative effect, and under what conditions, is of paramount importance.
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Affiliation(s)
- Ilige Youssef
- Centre National de la Recherche Scientifique, CNRS UMR_8113, Laboratoire de Biologie et Pharmacologie Appliquée, Cachan, France.,École Normale Supérieure Paris-Saclay, Université Paris-Saclay, Cachan, France
| | - Jean-Marc Ricort
- Centre National de la Recherche Scientifique, CNRS UMR_8113, Laboratoire de Biologie et Pharmacologie Appliquée, Cachan, France. .,École Normale Supérieure Paris-Saclay, Université Paris-Saclay, Cachan, France.,Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, USPC, Université Paris Descartes, Université Paris Diderot, Paris, France
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8
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Williams JA. Cholecystokinin (CCK) Regulation of Pancreatic Acinar Cells: Physiological Actions and Signal Transduction Mechanisms. Compr Physiol 2019; 9:535-564. [PMID: 30873601 DOI: 10.1002/cphy.c180014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Pancreatic acinar cells synthesize and secrete about 20 digestive enzymes and ancillary proteins with the processes that match the supply of these enzymes to their need in digestion being regulated by a number of hormones (CCK, secretin and insulin), neurotransmitters (acetylcholine and VIP) and growth factors (EGF and IGF). Of these regulators, one of the most important and best studied is the gastrointestinal hormone, cholecystokinin (CCK). Furthermore, the acinar cell has become a model for seven transmembrane, heterotrimeric G protein coupled receptors to regulate multiple processes by distinct signal transduction cascades. In this review, we briefly describe the chemistry and physiology of CCK and then consider the major physiological effects of CCK on pancreatic acinar cells. The majority of the review is devoted to the physiologic signaling pathways activated by CCK receptors and heterotrimeric G proteins and the functions they affect. The pathways covered include the traditional second messenger pathways PLC-IP3-Ca2+ , DAG-PKC, and AC-cAMP-PKA/EPAC that primarily relate to secretion. Then there are the protein-protein interaction pathways Akt-mTOR-S6K, the three major MAPK pathways (ERK, JNK, and p38 MAPK), and Ca2+ -calcineurin-NFAT pathways that primarily regulate non-secretory processes including biosynthesis and growth, and several miscellaneous pathways that include the Rho family small G proteins, PKD, FAK, and Src that may regulate both secretory and nonsecretory processes but are not as well understood. © 2019 American Physiological Society. Compr Physiol 9:535-564, 2019.
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Affiliation(s)
- John A Williams
- University of Michigan, Departments of Molecular & Integrative Physiology and Internal Medicine (Gastroenterology), Ann Arbor, Michigan, USA
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9
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Ramos-Alvarez I, Jensen RT. P21-activated kinase 4 in pancreatic acinar cells is activated by numerous gastrointestinal hormones/neurotransmitters and growth factors by novel signaling, and its activation stimulates secretory/growth cascades. Am J Physiol Gastrointest Liver Physiol 2018; 315:G302-G317. [PMID: 29672153 PMCID: PMC6139648 DOI: 10.1152/ajpgi.00005.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 04/06/2018] [Accepted: 04/12/2018] [Indexed: 01/31/2023]
Abstract
p21-activated kinases (PAKs) are highly conserved serine/threonine protein kinases, which are divided into two groups: group-I (PAKs1-3) and group-II (PAKs4-6). In various tissues, Group-II PAKs play important roles in cytoskeletal dynamics and cell growth as well as neoplastic development/progression. However, little is known about Group-II PAK's role in a number of physiological events, including their ability to be activated by gastrointestinal (GI) hormones/neurotransmitters/growth factors (GFs). We used rat pancreatic acini to explore the ability of GI hormones/neurotransmitters/GFs to activate Group-II-PAKs and the signaling cascades involved. Only PAK4 was detected in pancreatic acini. PAK4 was activated by endothelin, secretagogues-stimulating phospholipase C (bombesin, CCK-8, and carbachol), by pancreatic GFs (insulin, insulin-like growth factor 1, hepatocyte growth factor, epidermal growth factor, basic fibroblast growth factor, and platelet-derived growth factor), and by postreceptor stimulants (12-O-tetradecanoylphobol-13-acetate and A23187 ). CCK-8 activation of PAK4 required both high- and low-affinity CCK1-receptor state activation. It was reduced by PKC-, Src-, p44/42-, or p38-inhibition but not with phosphatidylinositol 3-kinase-inhibitors and only minimally by thapsigargin. A protein kinase D (PKD)-inhibitor completely inhibited CCK-8-stimulated PKD-activation; however, stimulated PAK4 phosphorylation was only inhibited by 60%, demonstrating that it is both PKD-dependent and PKD-independent. PF-3758309 and LCH-7749944, inhibitors of PAK4, decreased CCK-8-stimulated PAK4 activation but not PAK2 activation. Each inhibited ERK1/2 activation and amylase release induced by CCK-8 or bombesin. These results show that PAK4 has an important role in modulating signal cascades activated by a number of GI hormones/neurotransmitters/GFs that have been shown to mediate both physiological/pathological responses in acinar cells. Therefore, in addition to the extensive studies on PAK4 in pancreatic cancer, PAK4 should also be considered an important signaling molecule for pancreatic acinar physiological responses and, in the future, should be investigated for a possible role in pancreatic acinar pathophysiological responses, such as in pancreatitis. NEW & NOTEWORTHY This study demonstrates that the only Group-II p21-activated kinase (PAK) in rat pancreatic acinar cells is PAK4, and thus differs from islets/pancreatic cancer. Both gastrointestinal hormones/neurotransmitters stimulating PLC and pancreatic growth factors activate PAK4. With cholecystokinin (CCK), activation is PKC-dependent/-independent, requires both CCK1-R affinity states, Src, p42/44, and p38 activation. PAK4 activation is required for CCK-mediated p42/44 activation/amylase release. These results show PAK4 plays an important role in mediating CCK physiological signal cascades and suggest it may be a target in pancreatic acinar diseases besides cancer.
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Affiliation(s)
- Irene Ramos-Alvarez
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland
| | - R T Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland
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10
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Yuan J, Tan T, Geng M, Tan G, Chheda C, Pandol SJ. Novel Small Molecule Inhibitors of Protein Kinase D Suppress NF-kappaB Activation and Attenuate the Severity of Rat Cerulein Pancreatitis. Front Physiol 2017; 8:1014. [PMID: 29270134 PMCID: PMC5725929 DOI: 10.3389/fphys.2017.01014] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/22/2017] [Indexed: 01/09/2023] Open
Abstract
Nuclear factor-kappa B (NF-κB) activation is a key early signal regulating inflammatory and cell death responses in acute pancreatitis. Our previous in vitro studies with molecular approaches on AR42J cell showed that protein kinase D (PKD/PKD1) activation was required in NF-κB activation induced by cholecystokinin 8 (CCK) or carbachol (CCh) in pancreatic acinar cells. Recently developed small molecule PKD inhibitors, CID755673 and CRT0066101, provide potentially important pharmacological approaches to further investigate the effect of PKD in pancreatitis therapy. The aim of this study was to explore whether CID755673 and CRT0066101 block NF-κB activation with in vitro and in vivo models of experimental pancreatitis and whether the small molecule PKD inhibitors have therapeutic effects when given before or after the initiation of experimental pancreatitis. Freshly prepared pancreatic acini were incubated with CID755673 or CRT006101, followed by hyperstimulation with CCK or CCh. For in vivo experimental pancreatitis, rats were treated with intraperitoneal injection of CID755673 or CRT0066101 prior to or after administering cerulein or saline. PKD activation and NF-κB-DNA binding activity in nuclear extracts from pancreatic acini and tissue were measured. The effects of PKD inhibitors on pancreatitis responses were evaluated. Our results showed that both CID755673 or CRT0066101 selectively and specifically inhibited PKD without effects on related protein kinase Cs. Inhibition of PKD resulted in significantly attenuation of NF-κB activation in both in vitro and in vivo models of experimental pancreatitis. NF-κB inhibition by CID755673 was associated with decreased inflammatory responses and attenuated severity of the disease, which were indicated by less inflammatory cell infiltration, reduced pancreatic interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1), decreased intrapancreatic trypsin activation, and alleviation in pancreatic necrosis, edema and vacuolization. Furthermore, PKD inhibitor CID755673, given after the initiation of pancreatitis in experimental rat model, significantly attenuated the severity of acute pancreatitis. Therapies for acute pancreatitis are limited. Our results indicate that small chemical PKD inhibitors have significant potential as therapeutic interventions by suppressing NF-κB activation.
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Affiliation(s)
- Jingzhen Yuan
- Cedars-Sinai Medical Center, Los Angeles, CA, United States.,Veterans Affairs Greater Los Angeles Healthcare System, Department of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Tanya Tan
- Veterans Affairs Greater Los Angeles Healthcare System, Department of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Georgetown University Medical Center, Washington, DC, United States
| | - Meng Geng
- Veterans Affairs Greater Los Angeles Healthcare System, Department of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Frank Netter H. School of Medicine at Quinnipiac University, Hamden, CT, United States
| | - Grace Tan
- Veterans Affairs Greater Los Angeles Healthcare System, Department of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Vanderbilt University, Nashville, TN, United States
| | - Chintan Chheda
- Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Stephen J Pandol
- Cedars-Sinai Medical Center, Los Angeles, CA, United States.,Veterans Affairs Greater Los Angeles Healthcare System, Department of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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11
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Fleming AK, Storz P. Protein kinase C isoforms in the normal pancreas and in pancreatic disease. Cell Signal 2017; 40:1-9. [PMID: 28826907 DOI: 10.1016/j.cellsig.2017.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 08/17/2017] [Indexed: 12/16/2022]
Abstract
Protein Kinase C isoforms have been implicated in regulating multiple processes within the healthy pancreas. Moreover, their dysregulation contributes to all aspects of pancreatic disease. In this review, with a focus on acinar, ductal, and islet cells, we highlight the roles and contributions of the different PKC isoforms to normal pancreas function. We also discuss the contribution of PKC enzymes to pancreatic diseases, including insulin resistance and diabetes mellitus, as well as pancreatitis and the development and progression of pancreatic cancer.
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Affiliation(s)
- Alicia K Fleming
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, USA
| | - Peter Storz
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, USA.
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12
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Coate KC, Hernandez G, Thorne CA, Sun S, Le TDV, Vale K, Kliewer SA, Mangelsdorf DJ. FGF21 Is an Exocrine Pancreas Secretagogue. Cell Metab 2017; 25:472-480. [PMID: 28089565 PMCID: PMC5299054 DOI: 10.1016/j.cmet.2016.12.004] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 10/28/2016] [Accepted: 12/10/2016] [Indexed: 12/21/2022]
Abstract
The metabolic stress hormone FGF21 is highly expressed in exocrine pancreas, where its levels are increased by refeeding and chemically induced pancreatitis. However, its function in the exocrine pancreas remains unknown. Here, we show that FGF21 stimulates digestive enzyme secretion from pancreatic acinar cells through an autocrine/paracrine mechanism that requires signaling through a tyrosine kinase receptor complex composed of an FGF receptor and β-Klotho. Mice lacking FGF21 accumulate zymogen granules and are susceptible to pancreatic ER stress, an effect that is reversed by administration of recombinant FGF21. Mice carrying an acinar cell-specific deletion of β-Klotho also accumulate zymogen granules but are refractory to FGF21-stimulated secretion. Like the classical post-prandial secretagogue, cholecystokinin (CCK), FGF21 triggers intracellular calcium release via PLC-IP3R signaling. However, unlike CCK, FGF21 does not induce protein synthesis, thereby preventing protein accumulation. Thus, pancreatic FGF21 is a digestive enzyme secretagogue whose physiologic function is to maintain acinar cell proteostasis.
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Affiliation(s)
- Katie C Coate
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Genaro Hernandez
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Curtis A Thorne
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Shengyi Sun
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Thao D V Le
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kevin Vale
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Steven A Kliewer
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA.
| | - David J Mangelsdorf
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX 75390, USA.
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Abstract
BACKGROUND Acute pancreatitis is a serious medical disorder with no current therapies directed to the molecular pathogenesis of the disorder. Inflammation, inappropriate intracellular activation of digestive enzymes, and parenchymal acinar cell death by necrosis are the critical pathophysiologic processes of acute pancreatitis. Thus, it is necessary to elucidate the key molecular signals that mediate these pathobiologic processes and develop new therapeutic strategies to attenuate the appropriate signaling pathways in order to improve outcomes for this disease. A novel serine/threonine protein kinase D (PKD) family has emerged as key participants in signal transduction, and this family is increasingly being implicated in the regulation of multiple cellular functions and diseases. METHODS This review summarizes recent findings of our group and others regarding the signaling pathway and the biological roles of the PKD family in pancreatic acinar cells. In particular, we highlight our studies of the functions of PKD in several key pathobiologic processes associated with acute pancreatitis in experimental models. RESULTS Our findings reveal that PKD signaling is required for NF-κB activation/inflammation, intracellular zymogen activation, and acinar cell necrosis in rodent experimental pancreatitis. Novel small-molecule PKD inhibitors attenuate the severity of pancreatitis in both in vitro and in vivo experimental models. Further, this review emphasizes our latest advances in the therapeutic application of PKD inhibitors to experimental pancreatitis after the initiation of pancreatitis. CONCLUSIONS These novel findings suggest that PKD signaling is a necessary modulator in key initiating pathobiologic processes of pancreatitis, and that it constitutes a novel therapeutic target for treatments of this disorder.
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Affiliation(s)
- Jingzhen Yuan
- West Los Angeles VA Healthcare Center, UCLA/VA Greater Los Angeles Healthcare System, 11301 Wilshire Blvd, Bldg 258, Rm 340, Los Angeles, CA, 90073, USA.
| | - Stephen J Pandol
- West Los Angeles VA Healthcare Center, UCLA/VA Greater Los Angeles Healthcare System, 11301 Wilshire Blvd, Bldg 258, Rm 340, Los Angeles, CA, 90073, USA
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
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Nuche-Berenguer B, Ramos-Álvarez I, Jensen RT. The p21-activated kinase, PAK2, is important in the activation of numerous pancreatic acinar cell signaling cascades and in the onset of early pancreatitis events. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1122-36. [PMID: 26912410 DOI: 10.1016/j.bbadis.2016.02.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 02/02/2016] [Accepted: 02/17/2016] [Indexed: 12/30/2022]
Abstract
In a recent study we explored Group-1-p21-activated kinases (GP.1-PAKs) in rat pancreatic acini. Only PAK2 was present; it was activated by gastrointestinal-hormones/neurotransmitters and growth factors in a PKC-, Src- and small-GTPase-mediated manner. PAK2 was required for enzyme-secretion and ERK/1-2-activation. In the present study we examined PAK2's role in CCK and TPA-activation of important distal signaling cascades mediating their physiological/pathophysiological effects and analyzed its role in pathophysiological processes important in early pancreatitis. In rat pancreatic acini, PAK2-inhibition by the specific, GP.1.PAK-inhibitor, IPA-3-suppressed cholecystokinin (CCK)/TPA-stimulated activation of focal-adhesion kinases and mitogen-activated protein-kinases. PAK2-inhibition reversed the dual stimulatory/inhibitory effect of CCK/TPA on the PI3K/Akt/GSK-3β pathway. However, its inhibition did not affect PKC activation. PAK2-inhibition protected acini from CCK-induced ROS-generation; caspase/trypsin-activation, important in early pancreatitis; as well as from cell-necrosis. Furthermore, PAK2-inhibition reduced proteolytic-activation of PAK-2p34, which is involved in programmed-cell-death. To ensure that the study did not only rely in the specificity of IPA-3 as a PAK inhibitor, we used two other approaches for PAK inhibition, FRAX597 a ATP-competitive-GP.1-PAKs-inhibitor and infection with a PAK2-dominant negative(DN)-Advirus. Those two approaches confirmed the results obtained with IPA-3. This study demonstrates that PAK2 is important in mediating CCK's effect on the activation of signaling-pathways known to mediate its physiological/pathophysiological responses including several cellular processes linked to the onset of pancreatitis. Our results suggest that PAK2 could be a new, important therapeutic target to consider for the treatment of diseases involving deregulation of pancreatic acinar cells.
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Affiliation(s)
- Bernardo Nuche-Berenguer
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1804, USA
| | - Irene Ramos-Álvarez
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1804, USA
| | - R T Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1804, USA.
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15
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Nuche-Berenguer B, Moreno P, Jensen RT. Elucidation of the roles of the Src kinases in pancreatic acinar cell signaling. J Cell Biochem 2016; 116:22-36. [PMID: 25079913 DOI: 10.1002/jcb.24895] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Accepted: 07/25/2014] [Indexed: 12/13/2022]
Abstract
Recent studies report the Src-family kinases (SFK's) are important in a number of physiological and pathophysiological responses of pancreatic acinar cells (pancreatitis, growth, apoptosis); however, the role of SFKs in various signaling cascades important in mediating these cell functions is either not investigated or unclear. To address this we investigated the action of SFKs in these signaling cascades in rat pancreatic acini by modulating SFK activity using three methods: adenovirus-induced expression of an inactive dominant-negative CSK (Dn-CSK-Advirus) or wild-type CSK (Wt-CSK-Advirus), which activate or inhibit SFK, respectively, or using the chemical inhibitor, PP2, with its inactive control, PP3. CCK (0.3, 100 nM) and TPA (1 μM) activated SFK and altered the activation of FAK proteins (PYK2, p125(FAK)), adaptor proteins (p130(CAS), paxillin), MAPK (p42/44, JNK, p38), Shc, PKC (PKD, MARCKS), Akt but not GSK3-β. Changes in SFK activity by using the three methods of altering SFK activity affected CCK/TPAs activation of SFK, PYK2, p125(FAK), p130(CAS), Shc, paxillin, Akt but not p42/44, JNK, p38, PKC (PKD, MARCKS) or GSK3-β. With chemical inhibition the active SFK inhibitor, PP2, but not the inactive control analogue, PP3, showed these effects. For all stimulated changes pre-incubation with both adenoviruses showed similar effects to chemical inhibition of SFK activity. In conclusion, using three different approaches to altering Src activity allowed us to define fully for the first time the roles of SFKs in acinar cell signaling. Our results show that in pancreatic acinar cells, SFKs play a much wider role than previously reported in activating a number of important cellular signaling cascades shown to be important in mediating both acinar cell physiological and pathophysiological responses.
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Affiliation(s)
- Bernardo Nuche-Berenguer
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892-1804
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Ramos-Álvarez I, Moreno P, Mantey SA, Nakamura T, Nuche-Berenguer B, Moody TW, Coy DH, Jensen RT. Insights into bombesin receptors and ligands: Highlighting recent advances. Peptides 2015; 72:128-44. [PMID: 25976083 PMCID: PMC4641779 DOI: 10.1016/j.peptides.2015.04.026] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/29/2015] [Accepted: 04/30/2015] [Indexed: 12/22/2022]
Abstract
This following article is written for Prof. Abba Kastin's Festschrift, to add to the tribute to his important role in the advancement of the role of peptides in physiological, as well as pathophysiological processes. There have been many advances during the 35 years of his prominent role in the Peptide field, not only as editor of the journal Peptides, but also as a scientific investigator and editor of two volumes of the Handbook of Biological Active Peptides [146,147]. Similar to the advances with many different peptides, during this 35 year period, there have been much progress made in the understanding of the pharmacology, cell biology and the role of (bombesin) Bn receptors and their ligands in various disease states, since the original isolation of bombesin from skin of the European frog Bombina bombina in 1970 [76]. This paper will briefly review some of these advances over the time period of Prof. Kastin 35 years in the peptide field concentrating on the advances since 2007 when many of the results from earlier studies were summarized [128,129]. It is appropriate to do this because there have been 280 articles published in Peptides during this time on bombesin-related peptides and it accounts for almost 5% of all publications. Furthermore, 22 Bn publications we have been involved in have been published in either Peptides [14,39,55,58,81,92,93,119,152,216,225,226,231,280,302,309,355,361,362] or in Prof. Kastin's Handbook of Biological Active Peptides [137,138,331].
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Affiliation(s)
- Irene Ramos-Álvarez
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Paola Moreno
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Samuel A Mantey
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Taichi Nakamura
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Bernardo Nuche-Berenguer
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Terry W Moody
- Center for Cancer Research, Office of the Director, NCI, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - David H Coy
- Peptide Research Laboratory, Department of Medicine, Tulane University Health Sciences Center, New Orleans, LA 70112-2699, United States
| | - Robert T Jensen
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States.
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González N, Moreno P, Jensen RT. Bombesin receptor subtype 3 as a potential target for obesity and diabetes. Expert Opin Ther Targets 2015; 19:1153-70. [PMID: 26066663 DOI: 10.1517/14728222.2015.1056154] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Diabetes mellitus and obesity are important health issues; increasing in prevalence, both in the USA and globally. There are only limited pharmacological treatments, and although bariatric surgery is effective, new effective pharmacologic treatments would be of great value. This review covers one area of increasing interest that could yield new novel treatments of obesity/diabetes mellitus. It involves recognition of the central role the G-protein-coupled receptor, bombesin receptor subtype 3 (BRS-3) plays in energy/glucose metabolism. AREAS COVERED Since the initial observation that BRS-3 knockout mice develop obesity, hypertension, impaired glucose metabolism and hyperphagia, there have been numerous studies of the mechanisms involved and the development of selective BRS-3 agonists/antagonists, which have marked effects on body weight, feeding and glucose/insulin homeostasis. In this review, each of these areas is briefly reviewed. EXPERT OPINION BRS-3 plays an important role in glucose/energy homeostasis. The development of potent, selective BRS-3 agonists demonstrates promise as a novel approach to treat obesity/diabetic states. One important question that needs to be addressed is whether BRS-3 agonists need to be centrally acting. This is particularly important in light of recent animal and human studies that report transient cardiovascular side effects with centrally acting oral BRS agonists.
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Affiliation(s)
- Nieves González
- The Autonomous University of Madrid, IIS-Jiménez Díaz Foundation, Renal, Vascular and Diabetes Research Laboratory, Spanish Biomedical Research Network in Diabetes and, Associated Metabolic Disorders (CIBERDEM) , Madrid , Spain
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18
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Gastrointestinal hormones/neurotransmitters and growth factors can activate P21 activated kinase 2 in pancreatic acinar cells by novel mechanisms. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:2371-82. [PMID: 25979836 DOI: 10.1016/j.bbamcr.2015.05.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Revised: 04/28/2015] [Accepted: 05/07/2015] [Indexed: 12/15/2022]
Abstract
P-21-activated kinases (PAKs) are serine/threonine kinases comprising six isoforms divided in two groups, group-I (PAK1-3)/group-II (PAK4-6) which play important roles in cell cytoskeletal dynamics, survival, secretion and proliferation and are activated by diverse stimuli. However, little is known about PAKs ability to be activated by gastrointestinal (GI) hormones/neurotransmitters/growth-factors. We used rat pancreatic acini to explore the ability of GI-hormones/neurotransmitters/growth-factors to activate Group-I-PAKs and the signaling cascades involved. Only PAK2 was present in acini. PAK2 was activated by some pancreatic growth-factors [EGF, PDGF, bFGF], by secretagogues activating phospholipase-C (PLC) [CCK, carbachol, bombesin] and by post-receptor stimulants activating PKC [TPA], but not agents only mobilizing cellular calcium or increasing cyclic AMP. CCK-activation of PAK2 required both high- and low-affinity-CCK1-receptor-state activation. It was partially reduced by PKC- or Src-inhibition, but not with PI3K-inhibitors (wortmannin, LY294002) or thapsigargin. IPA-3, which prevents PAK2 binding to small-GTPases partially inhibited PAK2-activation, as well as reduced CCK-induced ERK1/2 activation and amylase release induced by CCK or bombesin. This study demonstrates pancreatic acini, possess only one Group-I-PAK, PAK2. CCK and other GI-hormones/neurotransmitters/growth-factors activate PAK2 via small GTPases (CDC42/Rac1), PKC and SFK but not cytosolic calcium or PI3K. CCK-activation of PAK2 showed several novel features being dependent on both receptor-activation states, having PLC- and PKC-dependent/independent components and small-GTPase-dependent/independent components. These results show that PAK2 is important in signaling cascades activated by numerous pancreatic stimuli which mediate their various physiological/pathophysiological responses and thus could be a promising target for the development of therapies in some pancreatic disorders such as pancreatitis.
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Abstract
OBJECTIVES In this study, we identified the protein kinases that play the most distinct roles in the occurrence of acute pancreatitis (AP). METHODS Gene expression profile data were downloaded from Gene Expression Omnibus database (GSE3644). The sample was from caerulein-induced AP mice. The intersection of the differentially expressed genes in AP mice taken from a protein kinase database was obtained for screening of the protein kinase encoded genes that were differentially expressed. Database for annotation, visualization, and integrated discovery was used for the functional enrichment analysis. Kinase inhibitors that regulated these kinases were retrieved from PubMed through text mining. RESULTS Twenty-nine differentially expressed kinase encoded genes were identified through screening. The functional enrichment analysis demonstrated that the functions of these genes were primarily enriched in "mitogen-activated protein kinase signaling pathway," followed by "extracellular regulated protein kinases pathway," "neurotrophin signaling pathway," "adherens junction," and "gap junction." SRC and epidermal growth factor receptor (EGFR) were related to extracellular regulated protein kinases pathway and also related to adherens junction as well as gap junction. On the basis of the regulated kinases, the kinase inhibitors reported in the literature were classified into multiple groups. CONCLUSIONS EGFR and SRC may be coexpressed in AP. The kinase inhibitors working together in SRC and EGFR may play better efficacy in the treatment of AP.
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Abstract
Pancreatic ductal adenocarcinoma (PDA) is characterized by advanced stage desmoplastic tumors with a high prevalence of genetic abnormalities. Occurrence of PDA is linked to activating Kras mutations and aberrant epidermal growth factor receptor signaling, leading to additional activation of wild-type Kras. As Kras is difficult to target, there is a constant need to identify novel targets acting downstream of this molecule in driving the formation or progression of PDA. Recently, it was shown that protein kinase D enzymes not only are increasingly expressed in PDA but also causatively linked to the development and progression of this cancer. They act downstream of both mutant Kras and growth factors and therefore may represent ideal novel targets.
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Affiliation(s)
| | - Peter Storz
- Correspondence to: Peter Storz, Mayo Clinic, Department of Cancer Biology, 4500 San Pablo Road, Jacksonville, FL 32224, USA. Tel: 904 953-6909, Fax: 904 953-0277,
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Coria AS, Masseroni ML, Díaz Añel AM. Regulation of PKD1-mediated Golgi to cell surface trafficking by Gαq subunits. Biol Cell 2013; 106:30-43. [PMID: 24175919 DOI: 10.1111/boc.201300052] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 10/28/2013] [Indexed: 11/30/2022]
Abstract
BACKGROUND INFORMATION Heterotrimeric GTP-binding proteins play a key role in cell trafficking regulation. Above all, specific Gβγ subunits have been shown to be a major component of a signal transduction pathway, which also involves phospholipases C (PLC), protein kinases C (PKC) and D (PKD), whose main function is to regulate transport between Golgi and plasma membrane. It was the involvement of PLC which led us to study the role of the other member of this G protein family, the α subunits, in the regulation of membrane fission at the Golgi apparatus. RESULTS Among constitutive active (QL) variants of different G protein α subunit sub-families, only GαqQL subunits were able to induce Golgi fragmentation, a phenotype that mainly reflects a membrane fission increase at this organelle. This phenotype was not observed with a GαqQL palmitoylation mutant, showing the need for a membrane-bounded subunit. Besides, GαqQL-dependent Golgi fission was blocked by specific PLC and PKC inhibitors, and in the presence of a PKD1-kinase dead variant. In addition, GαqQL was the only α subunit capable of inducing PKD1 phosphorylation. Finally, Vesicular Stomatitis Virus thermosensitive mutant glycoprotein (VSVG tsO45) transport assays have demonstrated that GαqQL acts directly on Golgi membranes to regulate trafficking between this organelle and plasma membrane. CONCLUSIONS All these results indicate Gαq subunits for the first time as a regulator of PKD-mediated intracellular trafficking between Golgi apparatus and plasma membrane, opening new perspectives in the understanding of internal trafficking regulation by external signals through G protein-coupled receptors.
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Affiliation(s)
- A Soledad Coria
- Laboratory of Neurobiology and Cell Biology, Instituto de Investigación Médica Mercedes y Martín Ferreyra (INIMEC), CONICET and Universidad Nacional de Córdoba. Friuli 2434, Barrio Parque Vélez Sarsfield, Córdoba 5016, Provincia de Córdoba, Argentina
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Moreno P, Mantey SA, Nuche-Berenguer B, Reitman ML, González N, Coy DH, Jensen RT. Comparative pharmacology of bombesin receptor subtype-3, nonpeptide agonist MK-5046, a universal peptide agonist, and peptide antagonist Bantag-1 for human bombesin receptors. J Pharmacol Exp Ther 2013; 347:100-16. [PMID: 23892571 DOI: 10.1124/jpet.113.206896] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Bombesin-receptor-subtype-3 (BRS-3) is an orphan G-protein-coupled receptor of the bombesin (Bn) family whose natural ligand is unknown and which does not bind any natural Bn-peptide with high affinity. It is present in the central nervous system, peripheral tissues, and tumors; however, its role in normal physiology/pathophysiology is largely unknown because of the lack of selective ligands. Recently, MK-5046 [(2S)-1,1,1-trifluoro-2-[4-(1H-pyrazol-1-yl)phenyl]-3-(4-{[1-(trifluoromethyl)cyclopropyl]methyl}-1H-imidazol-2-yl)propan-2-ol] and Bantag-1 [Boc-Phe-His-4-amino-5-cyclohexyl-2,4,5-trideoxypentonyl-Leu-(3-dimethylamino) benzylamide N-methylammonium trifluoroacetate], a nonpeptide agonist and a peptide antagonist, respectively, for BRS-3 have been described, but there have been limited studies on their pharmacology. We studied MK-5046 and Bantag-1 interactions with human Bn-receptors-human bombesin receptor subtype-3 (hBRS-3), gastrin-releasing peptide receptor (GRP-R), and neuromedin B receptor (NMB-R)-and compared them with the nonselective, peptide-agonist [d-Tyr6,βAla11,Phe13,Nle14]Bn-(6-14) (peptide #1). Receptor activation was detected by activation of phospholipase C (PLC), mitogen-activated protein kinase (MAPK), focal adhesion kinase (FAK), paxillin, and Akt. In hBRS-3 cells, the relative affinities were Bantag-1 (1.3 nM) > peptide #1 (2 nM) > MK-5046 (37-160 nM) > GRP, NMB (>10 μM), and the binding-dose-inhibition curves were broad (>4 logs), with Hill coefficients differing significantly from unity. Curve-fitting demonstrated high-affinity (MK-5046, Ki = 0.08 nM) and low-affinity (MK-5046, Ki = 11-29 nM) binding sites. For PLC activation in hBRS-3 cells, the relative potencies were MK-5046 (0.02 nM) > peptide #1 (6 nM) > GRP, NMB, Bantag-1 (>10 μM), and MK-5046 had a biphasic dose response, whereas peptide #1 was monophasic. Bantag-1 was a specific hBRS-3-antagonist. In hBRS-3 cells, MK-5046 was a full agonist for activation of MAPK, FAK, Akt, and paxillin; however, it was a partial agonist for phospholipase A2 (PLA2) activation. The kinetics of activation/duration of action for PLC/MAPK activation of MK-5046 and peptide #1 differed, with peptide #1 causing more rapid stimulation; however, MK-5046 had more prolonged activity. Our study finds that MK-5046 and Bantag-1 have high affinity/selectivity for hBRS-3. The nonpeptide MK-5046 and peptide #1 agonists differ markedly in their receptor coupling, ability to activate different signaling cascades, and kinetics/duration of action. These results show that their hBRS-3 receptor activation is not always concordant and could lead to markedly different cellular responses.
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Affiliation(s)
- Paola Moreno
- Digestive Diseases Branch (P.M., S.M., B.N.-B., R.T.J.) and Diabetes, Endocrinology, and Obesity Branch (M.L.R.), National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; Department of Metabolism, Nutrition and Hormones (N.G.), IIS-Fundación Jiménez Díaz, Madrid, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain; and Peptide Research Laboratories, Department of Medicine, Tulane Health Sciences Center, New Orleans, Louisiana (D.H.C.)
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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.
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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
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Abstract
OBJECTIVES This study aimed to search for protein kinases that play a role in acute pancreatitis and analyze their potential connection with each other. METHODS Information of human protein kinases were collected in protein kinase database, and then a systematic search was performed using PubMed for studies addressing the association between these kinases and acute pancreatitis. Gene Ontology Annotations were used to build interactions network for acute pancreatitis-associated protein kinases. RESULTS A total of 570 human protein kinases were found, in which 28 kinases play a role in acute pancreatitis. Among the 28 kinases, RIPK1, JAK2, SRC, EGFR, FYN, MET, JAK1, TYK2, and MTOR were annotated in Gene Ontology database. A gene ontology interactions network was built to visualize the common biological process these kinases participated in. CONCLUSIONS This study provides observations that protein kinases participate in all the sequential events in the exocrine pancreas in acute pancreatitis and that protein kinases are potential therapeutical target for acute pancreatitis.
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Amin R, Sharma S, Ratakonda S, Hassan HA. Extracellular nucleotides inhibit oxalate transport by human intestinal Caco-2-BBe cells through PKC-δ activation. Am J Physiol Cell Physiol 2013; 305:C78-89. [PMID: 23596171 DOI: 10.1152/ajpcell.00339.2012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Nephrolithiasis remains a major health problem in Western countries. Seventy to 80% of kidney stones are composed of calcium oxalate, and small changes in urinary oxalate affect risk of kidney stone formation. Intestinal oxalate secretion mediated by the anion exchanger SLC26A6 plays an essential role in preventing hyperoxaluria and calcium oxalate nephrolithiasis, indicating that understanding the mechanisms regulating intestinal oxalate transport is critical for management of hyperoxaluria. Purinergic signaling modulates several intestinal processes through pathways including PKC activation, which we previously found to inhibit Slc26a6 activity in mouse duodenal tissue. We therefore examined whether purinergic stimulation with ATP and UTP affects oxalate transport by human intestinal Caco-2-BBe (C2) cells. We measured [¹⁴C]oxalate uptake in the presence of an outward Cl⁻ gradient as an assay of Cl⁻/oxalate exchange activity, ≥50% of which is mediated by SLC26A6. We found that ATP and UTP significantly inhibited oxalate transport by C2 cells, an effect blocked by the PKC inhibitor Gö-6983. Utilizing pharmacological agonists and antagonists, as well as PKC-δ knockdown studies, we observed that ATP inhibits oxalate transport through the P2Y₂ receptor, PLC, and PKC-δ. Biotinylation studies showed that ATP inhibits oxalate transport by lowering SLC26A6 surface expression. These findings are of potential relevance to pathophysiology of inflammatory bowel disease-associated hyperoxaluria, where supraphysiological levels of ATP/UTP are expected and overexpression of the P2Y₂ receptor has been reported. We conclude that ATP and UTP inhibit oxalate transport by lowering SLC26A6 surface expression in C2 cells through signaling pathways including the P2Y₂ purinergic receptor, PLC, and PKC-δ.
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Affiliation(s)
- Ruhul Amin
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA
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Hao F, Wu DD, Xu X, Cui MZ. Histamine induces activation of protein kinase D that mediates tissue factor expression and activity in human aortic smooth muscle cells. Am J Physiol Heart Circ Physiol 2012; 303:H1344-52. [PMID: 23001835 DOI: 10.1152/ajpheart.00500.2011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Histamine, an inflammatory mediator, has been shown to influence the pathogenesis of vascular wall cells. However, the molecular basis of its influence is not well understood. Our data reveal that histamine markedly induces protein kinase D (PKD) activation in human aortic smooth muscle cells. PKD belongs to a family of serine/threonine protein kinases, and its function in vascular disease is largely unknown. Our data show that histamine-induced PKD phosphorylation is dependent on the activation of histamine receptor 1 and protein kinase C (PKC). To determine the role of PKD in the histamine pathway, we employed a small-interfering RNA approach to downregulate PKD expression and found that PKD1 and PKD2 are key mediators for expression of tissue factor (TF), which is the key initiator of blood coagulation and is important for thrombosis. Our results show that PKD2 predominantly mediates histamine-induced TF expression via the p38 mitogen-activated protein kinase (MAPK) pathway, whereas PKD1 mediates histamine-induced TF expression through a p38 MAPK-independent pathway. We demonstrate that histamine induces TF expression via the PKC-dependent PKD activation. Our data provide the first evidence that PKD is a new component in histamine signaling in live cells and that PKD has a novel function in the histamine signaling pathway leading to gene expression, as evidenced by TF expression. Importantly, our data reveal a regulatory link from histamine to PKD and TF, providing new insights into the mechanisms of coagulation and the development of atherothrombosis.
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Affiliation(s)
- Feng Hao
- Department of Biomedical & Diagnostic Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN 37996, USA
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Abstract
PURPOSE OF REVIEW In this article, recent advances in the pathogenesis of acute pancreatitis have been reviewed. RECENT FINDINGS Pathologic intra-acinar trypsinogen activation had been hypothesized to be the central mechanism of pancreatitis for over a century. This hypothesis could be explored for the first time with the development of a novel mouse model lacking pathologic intra-acinar trypsinogen activation. It became clear that intra-acinar trypsinogen activation contributes to early acinar injury, but local and systemic inflammation progress independently during pancreatitis. Early intra-acinar nuclear factor kappa B (NFκB) activation, which occurs parallel to but independent of trypsinogen activation, may be crucial in pancreatitis. Although the mechanism of NFκB and trypsinogen activation is not entirely clear, further insights have been made into key pathogenic cellular events such as calcium signaling, mitochondrial dysfunction, endoplasmic reticulum (ER) stress, autophagy and impaired trafficking, and lysosomal and secretory responses. Cellular intrinsic damage-sensing mechanisms that lead to activation of the inflammatory response aimed at repair, but lead to disease when overwhelmed, are beginning to be understood. SUMMARY New findings necessitate a paradigm shift in our understanding of acute pancreatitis. Intra-acinar trypsinogen activation leads to early pancreatic injury, but the inflammatory response of acute pancreatitis develops independently, driven by early activation of inflammatory pathways.
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Sancho V, Nuche-Berenguer B, Jensen RT. The Src kinase Yes is activated in pancreatic acinar cells by gastrointestinal hormones/neurotransmitters, but not pancreatic growth factors, which stimulate its association with numerous other signaling molecules. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1823:1285-94. [PMID: 22617836 PMCID: PMC3404614 DOI: 10.1016/j.bbamcr.2012.05.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 04/25/2012] [Accepted: 05/14/2012] [Indexed: 12/13/2022]
Abstract
For growth factors, cytokines, G-protein-coupled receptors and numerous other stimuli, the Src Family of kinases (SFK) play a central signaling role. SFKs also play an important role in pancreatic acinar cell function including metabolism, secretion, endocytosis, growth and cytoskeletal integrity, although the specific SFKs involved are not fully known. In the present study we used specific antibodies for the SFK, Yes, to determine its presence, activation by pancreatic secretagogues or growth factors, and interaction with cellular signaling cascades mediated by CCK in which Yes participates in to cause acinar cell responses. Yes was identified in acini and secretagogues known to activate phospholipase C (PLC) [CCK, carbachol, bombesin] as well as post-receptor stimulants activating PKC [TPA] or mobilizing cellular calcium [thapsigargin/calcium ionophore (A23187)] each activated Yes. Secretin, which activates adenylate cyclase did not stimulate Yes, nor did pancreatic growth factors. CCK activation of Yes required both high- and low-affinity CCK(1)-receptor states. TPA-/CCK-stimulated Yes activation was completely inhibited by thapsigargin and the PKC inhibitor, GF109203X. CCK/TPA stimulated the association of Yes with focal adhesion kinases (Pyk2, FAK) and its autophosphorylated forms (pY397FAK, pY402Pyk2). Moreover, CCK/TPA stimulated Yes interacted with a number of other signaling proteins, including Shc, PKD, p130(Cas), PI3K and PTEN. This study demonstrates that in rat pancreatic acini, the SFK member Yes is expressed and activated by CCK and other gastrointestinal hormones/neurotransmitters. Because its activation results in the direct activation of many cellular signaling cascades that have been shown to mediate CCK's effect in acinar cell function our results suggest that it is one of the important pancreatic SFKs mediating these effects.
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Affiliation(s)
- Veronica Sancho
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1804, USA
| | - Bernardo Nuche-Berenguer
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1804, USA
| | - R. T. Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1804, USA
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Szanda G, Rajki A, Spät A. Control mechanisms of mitochondrial Ca(2+) uptake - feed-forward modulation of aldosterone secretion. Mol Cell Endocrinol 2012; 353:101-8. [PMID: 21924321 DOI: 10.1016/j.mce.2011.08.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 08/31/2011] [Accepted: 08/31/2011] [Indexed: 12/23/2022]
Abstract
Mitochondrial Ca(2+) signal activates metabolism by boosting pyridine nucleotide reduction and ATP synthesis or, if Ca(2+) sequestration is supraphysiological, may even lead to apoptosis. Although the molecular background of mitochondrial Ca(2+) uptake has recently been elucidated, the regulation of Ca(2+) handling is still not properly clarified. In human adrenocortical H295R cells we found a regulatory mechanism involving p38 MAPK and novel-type PKC isoforms. Upon stimulation with angiotensin II (AII) these kinases are activated typically prior to the release of Ca(2+) and - most probably by reducing the Ca(2+) permeation through the outer mitochondrial membrane - attenuate mitochondrial Ca(2+) uptake in a feed-forward manner. The biologic significance of the kinase-mediated reduction of mitochondrial Ca(2+) signal is also reflected by the attenuation of AII-mediated aldosterone secretion. As another feed-forward mechanism, we found in HEK-293T and H295R cells that Ca(2+) signal evoked either by IP(3) or by voltage-gated influx is accompanied by a concomitant cytosolic Mg(2+) signal. In permeabilized HEK-293T cells Mg(2+) was found to be a potent inhibitor of mitochondrial Ca(2+) uptake in the physiologic [Mg(2+)] and [Ca(2+)] range. Thus, these inhibitory mechanisms may serve not only as protection against mitochondrial Ca(2+) overload and subsequent apoptosis but also have the potential to substantially alter physiological responses.
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Affiliation(s)
- Gergö Szanda
- Department of Physiology, Semmelweis University, POB 259, H-1444 Budapest, Hungary
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The role of PKC isoforms in the inhibition of NF-κB activation by vitamin K2 in human hepatocellular carcinoma cells. J Nutr Biochem 2012; 23:1668-75. [PMID: 22475810 DOI: 10.1016/j.jnutbio.2011.11.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 11/03/2011] [Accepted: 11/30/2011] [Indexed: 12/31/2022]
Abstract
Vitamin K (VK) has diverse protective effects against osteoporosis, atherosclerosis and carcinogenesis. We recently reported that menatetrenone, a VK2 analogue, suppressed nuclear factor (NF)-κB activation in human hepatoma cells. Although NF-κB is regulated by isoforms of protein kinase C (PKC), the involvement of PKCs in VK2-mediated NF-κB inhibition remains unknown. Therefore, the effects of VK2 on the activation and the kinase activity of each PKC isoform were investigated. The human hepatoma Huh7 cells were treated with PKC isoform-specific inhibitors and/or siRNAs against each PKC isoform with or without 12-O-tetradecanoylphorbol-13-acetate (TPA). VK2 inhibited the TPA-induced NF-κB activation in Huh7 cells. NF-κB activity was inhibited by the pan-PKC inhibitor Ro-31-8425, but not by the PKCα-specific inhibitor Gö6976. The knockdown of individual PKC isoforms including PKCα, δ and ɛ showed only marginal effects on the NF-κB activity. However, the knockdown of both PKCδ and PKCɛ, together with treatment with a PKCα-specific inhibitor, depressed the NF-κB activity. VK2 suppressed the PKCα kinase activity and the phosphorylation of PKCɛ after TPA treatment, but neither the activation nor the enzyme activity of PKCδ was affected. The knockdown of PKCɛ abolished the TPA-induced phosphorylation of PKD1, and the effects of PKD1 knockdown on NF-κB activation were similar to those of PKCɛ knockdown. Collectively, all of the PKCs, including α, δ and ɛ, and PKD1 are involved in the TPA-mediated activation of NF-κB. VK2 inhibited the NF-κB activation through the inhibition of PKCα and ɛ kinase activities, as well as subsequent inhibition of PKD1 activation.
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Yuan J, Liu Y, Tan T, Guha S, Gukovsky I, Gukovskaya A, Pandol SJ. Protein kinase d regulates cell death pathways in experimental pancreatitis. Front Physiol 2012; 3:60. [PMID: 22470346 PMCID: PMC3313474 DOI: 10.3389/fphys.2012.00060] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 02/29/2012] [Indexed: 11/13/2022] Open
Abstract
Inflammation and acinar cell necrosis are two major pathological responses of acute pancreatitis, a serious disorder with no current therapies directed to its molecular pathogenesis. Serine/threonine protein kinase D family, which includes PKD/PKD1, PKD2, and PKD3, has been increasingly implicated in the regulation of multiple physiological and pathophysiological effects. We recently reported that PKD/PKD1, the predominant PKD isoform expressed in rat pancreatic acinar cells, mediates early events of pancreatitis including NF-κB activation and inappropriate intracellular digestive enzyme activation. In current studies, we investigated the role and mechanisms of PKD/PKD1 in the regulation of necrosis in pancreatic acinar cells by using two novel small molecule PKD inhibitors CID755673 and CRT0066101 and molecular approaches in in vitro and in vivo experimental models of acute pancreatitis. Our results demonstrated that both CID755673 and CRT0066101 are PKD-specific inhibitors and that PKD/PKD1 inhibition by either the chemical inhibitors or specific PKD/PKD1 siRNAs attenuated necrosis while promoting apoptosis induced by pathological doses of cholecystokinin-octapeptide (CCK) in pancreatic acinar cells. Conversely, up-regulation of PKD expression in pancreatic acinar cells increased necrosis and decreased apoptosis. We further showed that PKD/PKD1 regulated several key cell death signals including inhibitors of apoptotic proteins, caspases, receptor-interacting protein kinase 1 to promote necrosis. PKD/PKD1 inhibition by CID755673 significantly ameliorated necrosis and severity of pancreatitis in an in vivo experimental model of acute pancreatitis. Thus, our studies indicate that PKD/PKD1 is a key mediator of necrosis in acute pancreatitis and that PKD/PKD1 may represent a potential therapeutic target in acute pancreatitis.
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Affiliation(s)
- Jingzhen Yuan
- South California Research Center for Alcoholic Liver and Pancreatic Diseases, Veterans Affairs Greater Los Angeles Healthcare System, University of California at Los Angeles Los Angeles, CA, USA
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Oh YI, Yang EJ, Choi SM, Kang CW. The Effect of Electroacupuncture on Insulin-Like Growth Factor-I and Oxidative Stress in an Animal Model of Renal Failure-Induced Hypertension. ACTA ACUST UNITED AC 2012; 35:634-43. [DOI: 10.1159/000339640] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 05/22/2012] [Indexed: 11/19/2022]
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Hassan HA, Cheng M, Aronson PS. Cholinergic signaling inhibits oxalate transport by human intestinal T84 cells. Am J Physiol Cell Physiol 2011; 302:C46-58. [PMID: 21956166 DOI: 10.1152/ajpcell.00075.2011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Urolithiasis remains a very common disease in Western countries. Seventy to eighty percent of kidney stones are composed of calcium oxalate, and minor changes in urinary oxalate affect stone risk. Intestinal oxalate secretion mediated by anion exchanger SLC26A6 plays a major constitutive role in limiting net absorption of ingested oxalate, thereby preventing hyperoxaluria and calcium oxalate urolithiasis. Using the relatively selective PKC-δ inhibitor rottlerin, we had previously found that PKC-δ activation inhibits Slc26a6 activity in mouse duodenal tissue. To identify a model system to study physiologic agonists upstream of PKC-δ, we characterized the human intestinal cell line T84. Knockdown studies demonstrated that endogenous SLC26A6 mediates most of the oxalate transport by T84 cells. Cholinergic stimulation with carbachol modulates intestinal ion transport through signaling pathways including PKC activation. We therefore examined whether carbachol affects oxalate transport in T84 cells. We found that carbachol significantly inhibited oxalate transport by T84 cells, an effect blocked by rottlerin. Carbachol also led to significant translocation of PKC-δ from the cytosol to the membrane of T84 cells. Using pharmacological inhibitors, we observed that carbachol inhibits oxalate transport through the M(3) muscarinic receptor and phospholipase C. Utilizing the Src inhibitor PP2 and phosphorylation studies, we found that the observed regulation downstream of PKC-δ is partially mediated by c-Src. Biotinylation studies revealed that carbachol inhibits oxalate transport by reducing SLC26A6 surface expression. We conclude that carbachol negatively regulates oxalate transport by reducing SLC26A6 surface expression in T84 cells through signaling pathways including the M(3) muscarinic receptor, phospholipase C, PKC-δ, and c-Src.
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Affiliation(s)
- Hatim A Hassan
- Section of Nephrology, Dept. of Medicine, The Univ. of Chicago, 5841 S. Maryland Ave., MC5100, Chicago, IL 60637, USA.
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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.
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Sancho V, Berna MJ, Thill M, Jensen RT. PKCθ activation in pancreatic acinar cells by gastrointestinal hormones/neurotransmitters and growth factors is needed for stimulation of numerous important cellular signaling cascades. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:2145-56. [PMID: 21810446 DOI: 10.1016/j.bbamcr.2011.07.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 07/12/2011] [Accepted: 07/13/2011] [Indexed: 02/08/2023]
Abstract
The novel PKCθ isoform is highly expressed in T-cells, brain and skeletal muscle and originally thought to have a restricted distribution. It has been extensively studied in T-cells and shown to be important for apoptosis, T-cell activation and proliferation. Recent studies showed its presence in other tissues and importance in insulin signaling, lung surfactant secretion, intestinal barrier permeability, platelet and mast-cell functions. However, little information is available for PKCθ activation by gastrointestinal (GI) hormones/neurotransmitters and growth factors. In the present study we used rat pancreatic acinar cells to explore their ability to activate PKCθ and the possible interactions with important cellular mediators of their actions. Particular attention was paid to cholecystokinin (CCK), a physiological regulator of pancreatic function and important in pathological processes affecting acinar function, like pancreatitis. PKCθ-protein/mRNA was present in the pancreatic acini, and T538-PKCθ phosphorylation/activation was stimulated only by hormones/neurotransmitters activating phospholipase C. PKCθ was activated in time- and dose-related manner by CCK, mediated 30% by high-affinity CCK(A)-receptor activation. CCK stimulated PKCθ translocation from cytosol to membrane. PKCθ inhibition (by pseudostrate-inhibitor or dominant negative) inhibited CCK- and TPA-stimulation of PKD, Src, RafC, PYK2, p125(FAK) and IKKα/β, but not basal/stimulated enzyme secretion. Also CCK- and TPA-induced PKCθ activation produced an increment in PKCθ's direct association with AKT, RafA, RafC and Lyn. These results show for the first time the PKCθ presence in pancreatic acinar cells, its activation by some GI hormones/neurotransmitters and involvement in important cell signaling pathways mediating physiological responses (enzyme secretion, proliferation, apoptosis, cytokine expression, and pathological responses like pancreatitis and cancer growth).
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Affiliation(s)
- Veronica Sancho
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1804, USA
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Thrower EC, Yuan J, Usmani A, Liu Y, Jones C, Minervini SN, Alexandre M, Pandol SJ, Guha S. A novel protein kinase D inhibitor attenuates early events of experimental pancreatitis in isolated rat acini. Am J Physiol Gastrointest Liver Physiol 2011; 300:G120-9. [PMID: 20947701 PMCID: PMC3025506 DOI: 10.1152/ajpgi.00300.2010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Novel protein kinase C isoforms (PKC δ and ε) mediate early events in acute pancreatitis. Protein kinase D (PKD/PKD1) is a convergent point of PKC δ and ε in the signaling pathways triggered through CCK or cholinergic receptors and has been shown to activate the transcription factor NF-κB in acute pancreatitis. For the present study we hypothesized that a newly developed PKD/PKD1 inhibitor, CRT0066101, would prevent the initial events leading to pancreatitis. We pretreated isolated rat pancreatic acinar cells with CRT0066101 and a commercially available inhibitor Gö6976 (10 μM). This was followed by stimulation for 60 min with high concentrations of cholecystokinin (CCK, 0.1 μM), carbachol (CCh, 1 mM), or bombesin (10 μM) to induce initial events of pancreatitis. PKD/PKD1 phosphorylation and activity were measured as well as zymogen activation, amylase secretion, cell injury and NF-κB activation. CRT0066101 dose dependently inhibited secretagogue-induced PKD/PKD1 activation and autophosphorylation at Ser-916 with an IC(50) ∼3.75-5 μM but had no effect on PKC-dependent phosphorylation of the PKD/PKD1 activation loop (Ser-744/748). Furthermore, CRT0066101 reduced secretagogue-induced zymogen activation and amylase secretion. Gö6976 reduced zymogen activation but not amylase secretion. Neither inhibitor affected basal zymogen activation or secretion. CRT0066101 did not affect secretagogue-induced cell injury or changes in cell morphology, but it reduced NF-κB activation by 75% of maximal for CCK- and CCh-stimulated acinar cells. In conclusion, CRT0066101 is a potent and specific PKD family inhibitor. Furthermore, PKD/PKD1 is a potential mediator of zymogen activation, amylase secretion, and NF-κB activation induced by a range of secretagogues in pancreatic acinar cells.
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Affiliation(s)
- Edwin C. Thrower
- 1Department of Internal Medicine, Section of Digestive Diseases, and the Veterans Administration Connecticut Healthcare, West Haven, and Yale University School of Medicine, New Haven, Connecticut;
| | - Jingzhen Yuan
- 2Southern California Research Center for Alcoholic Liver and Pancreatic Diseases, Veterans Affairs Greater Los Angeles Health Care System and University of California, Los Angeles, California; and
| | - Ashar Usmani
- 1Department of Internal Medicine, Section of Digestive Diseases, and the Veterans Administration Connecticut Healthcare, West Haven, and Yale University School of Medicine, New Haven, Connecticut;
| | - Yannan Liu
- 2Southern California Research Center for Alcoholic Liver and Pancreatic Diseases, Veterans Affairs Greater Los Angeles Health Care System and University of California, Los Angeles, California; and
| | - Courtney Jones
- 1Department of Internal Medicine, Section of Digestive Diseases, and the Veterans Administration Connecticut Healthcare, West Haven, and Yale University School of Medicine, New Haven, Connecticut;
| | - Samantha N. Minervini
- 1Department of Internal Medicine, Section of Digestive Diseases, and the Veterans Administration Connecticut Healthcare, West Haven, and Yale University School of Medicine, New Haven, Connecticut;
| | - Martine Alexandre
- 1Department of Internal Medicine, Section of Digestive Diseases, and the Veterans Administration Connecticut Healthcare, West Haven, and Yale University School of Medicine, New Haven, Connecticut;
| | - Stephen J. Pandol
- 2Southern California Research Center for Alcoholic Liver and Pancreatic Diseases, Veterans Affairs Greater Los Angeles Health Care System and University of California, Los Angeles, California; and
| | - Sushovan Guha
- 3University of Texas M.D. Anderson Cancer Center Department of Gastroenterology, Hepatology and Nutrition, Houston, Texas
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Berna MJ, Seiz O, Nast JF, Benten D, Bläker M, Koch J, Lohse AW, Pace A. CCK1 and CCK2 receptors are expressed on pancreatic stellate cells and induce collagen production. J Biol Chem 2010; 285:38905-14. [PMID: 20843811 DOI: 10.1074/jbc.m110.125534] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The gastrointestinal hormone cholecystokinin (CCK) can induce acute pancreatitis in rodents through its action on acinar cells. Treatment with CCK, in combination with other agents, represents the most commonly used model to induce experimental chronic pancreatitis. Pancreatic stellate cells (PSC) are responsible for pancreatic fibrosis and therefore play a predominant role in the genesis of chronic pancreatitis. However, it is not known whether PSC express CCK receptors. Using real time PCR techniques, we demonstrate that CCK1 and CCK2 receptors are expressed on rat PSC. Interestingly both CCK and gastrin significantly induced type I collagen synthesis. Moreover, both inhibit proliferation. These effects are comparable with TGF-β-stimulated PSC. Furthermore, the natural agonists CCK and gastrin induce activation of pro-fibrogenic pathways Akt, ERK, and Src. Using specific CCK1 and CCK2 receptor (CCK2R) inhibitors, we found that Akt activation is mainly mediated by CCK2R. Akt activation by CCK and gastrin could be inhibited by the PI3K inhibitor wortmannin. Activation of ERK and the downstream target Elk-1 could be inhibited by the MEK inhibitor U0126. These data suggest that CCK and gastrin have direct activating effects on PSC, are able to induce collagen synthesis in these cells, and therefore appear to be important regulators of pancreatic fibrogenesis. Furthermore, similar to TGF-β, both CCK and gastrin inhibit proliferation in PSC.
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Affiliation(s)
- Marc J Berna
- Universitätsklinikum Eppendorf, Medizinische Klinik I, 20246 Hamburg, Germany
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Sancho V, Moody TW, Mantey SA, Di Florio A, Uehara H, Coy DH, Jensen RT. Pharmacology of putative selective hBRS-3 receptor agonists for human bombesin receptors (BnR): affinities, potencies and selectivity in multiple native and BnR transfected cells. Peptides 2010; 31:1569-78. [PMID: 20438784 PMCID: PMC2905478 DOI: 10.1016/j.peptides.2010.04.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 04/23/2010] [Accepted: 04/23/2010] [Indexed: 11/28/2022]
Abstract
The orphan receptor, bombesin receptor subtype-3(BRS-3) is a G-protein-coupled receptor classified in the bombesin (Bn) receptor family because of its high homology (47-51%) with other members of this family [gastrin-releasing peptide receptor [GRPR] and neuromedin B receptor [NMBR]]. There is increasing interest in BRS-3, because primarily from receptor knockout studies, it seems important in energy metabolism, glucose control, insulin secretion, motility and tumor growth. Pharmacological tools to study the role of BRS-3 in physiology/pathophysiology are limited because the natural ligand is unknown and BRS-3 has low affinity for all naturally occurring Bn-related peptides. However, a few years ago a synthetic high-affinity agonist [dTyr(6),betaAla(11),Phe(13),Nle(14)]Bn-(6-14) was described but was nonselective for BRS-3 over other Bn receptors. Based on this peptide, in various studies a number of putative selective, high-potency hBRS-3 agonists were described, however the results on their selectivity are conflicting in a number of cases. The purpose of the present study was to thoroughly study the pharmacology of four of the most select/potent putative hBRS-3 agonists (#2-4, 16a). Each was studied in multiple well-characterized Bn receptor-transfected cells and native Bn receptor bearing cells, using binding studies, alterations in cellular signaling (PLC, PKD) and changes in cellular function(growth). Two peptides (#2, #3) had nM affinities/potencies for hBRS-3, peptide #4 had low affinity/potency, and peptide #16a very low (>3000 nM). Peptide#3 had the highest selectivity for hBRS-3 (100-fold), whereas #2, 4 had lower selectivity. Peptide #16a's selectivity could not be determined because of its low affinity/potencies for all hBn receptors. These results show that peptide #3 is the preferred hBRS-3 agonist for studies at present, although its selectivity of only 100-fold may limit its utility in some cases. This study underscores the importance of full pharmacological characterization of newly reported selective agonists.
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Affiliation(s)
- Veronica Sancho
- Digestive Diseases Branch, NIDDK, and Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Terry W. Moody
- NCI Office of the Director, CCR, NCI and Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Samuel A. Mantey
- Digestive Diseases Branch, NIDDK, and Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Alessia Di Florio
- Digestive Diseases Branch, NIDDK, and Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Hirotsugu Uehara
- Digestive Diseases Branch, NIDDK, and Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - David H. Coy
- Peptide Research Laboratories, Department of Medicine, Tulane Health Sciences Center, New Orleans, Louisiana 70112-2699
| | - Robert T. Jensen
- Digestive Diseases Branch, NIDDK, and Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland 20892-1804
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Cawston EE, Miller LJ. Therapeutic potential for novel drugs targeting the type 1 cholecystokinin receptor. Br J Pharmacol 2009; 159:1009-21. [PMID: 19922535 DOI: 10.1111/j.1476-5381.2009.00489.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cholecystokinin (CCK) is a physiologically important gastrointestinal and neuronal peptide hormone, with roles in stimulating gallbladder contraction, pancreatic secretion, gastrointestinal motility and satiety. CCK exerts its effects via interactions with two structurally related class I guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs), the CCK(1) receptor and the CCK(2) receptor. Here, we focus on the CCK(1) receptor, with particular relevance to the broad spectrum of signalling initiated by activation with the natural full agonist peptide ligand, CCK. Distinct ligand-binding pockets have been defined for the natural peptide ligand and for some non-peptidyl small molecule ligands. While many CCK(1) receptor ligands have been developed and have had their pharmacology well described, their clinical potential has not yet been fully explored. The case is built for the potential importance of developing more selective partial agonists and allosteric modulators of this receptor that could have important roles in the treatment of common clinical syndromes.
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Affiliation(s)
- Erin E Cawston
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, AZ, USA
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Abstract
OBJECTIVES To define the role of protein kinase C delta (PKC delta) in acinar cell responses to the hormone cholecystokinin-8 (CCK) using isoform-specific inhibitors and a previously unreported genetic deletion model. METHODS Pancreatic acinar cells were isolated from (1) rat, and pretreated with a PKC delta-specific inhibitor or (2) PKC delta-deficient and wild type mice. Isolated cells were stimulated with CCK (0.001-100 nmol/L) and cell responses were measured. RESULTS The PKC delta inhibitor did not affect stimulated amylase secretion from rat pancreatic acinar cells. Cholecystokinin-8 stimulation induced a typical biphasic dose-response curve for amylase secretion in acinar cells isolated from both PKC delta(-/-) and wild type mice, with maximal stimulation at 10-pmol/L CCK. Cholecystokinin-8 (100 nmol/L) induced zymogen and nuclear factor kappaB activation in both PKC delta(-/-) and wild type mice, although it was up to 50% less in PKC delta(-/-). CONCLUSIONS In contrast to previous studies, this study has used specific and complementary approaches to examine PKC delta-mediated acinar cell responses. We could not confirm that it mediates amylase release but corroborated its role in the early stages of acute pancreatitis.
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Amadesi S, Grant AD, Cottrell GS, Vaksman N, Poole DP, Rozengurt E, Bunnett NW. Protein kinase D isoforms are expressed in rat and mouse primary sensory neurons and are activated by agonists of protease-activated receptor 2. J Comp Neurol 2009; 516:141-56. [PMID: 19575452 DOI: 10.1002/cne.22104] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Serine proteases generated during injury and inflammation cleave protease-activated receptor 2 (PAR(2)) on primary sensory neurons to induce neurogenic inflammation and hyperalgesia. Hyperalgesia requires sensitization of transient receptor potential vanilloid (TRPV) ion channels by mechanisms involving phospholipase C and protein kinase C (PKC). The protein kinase D (PKD) serine/threonine kinases are activated by diacylglycerol and PKCs and can phosphorylate TRPV1. Thus, PKDs may participate in novel signal transduction pathways triggered by serine proteases during inflammation and pain. However, it is not known whether PAR(2) activates PKD, and the expression of PKD isoforms by nociceptive neurons is poorly characterized. By using HEK293 cells transfected with PKDs, we found that PAR(2) stimulation promoted plasma membrane translocation and phosphorylation of PKD1, PKD2, and PKD3, indicating activation. This effect was partially dependent on PKCepsilon. By immunofluorescence and confocal microscopy, with antibodies against PKD1/PKD2 and PKD3 and neuronal markers, we found that PKDs were expressed in rat and mouse dorsal root ganglia (DRG) neurons, including nociceptive neurons that expressed TRPV1, PAR(2), and neuropeptides. PAR(2) agonist induced phosphorylation of PKD in cultured DRG neurons, indicating PKD activation. Intraplantar injection of PAR(2) agonist also caused phosphorylation of PKD in neurons of lumbar DRG, confirming activation in vivo. Thus, PKD1, PKD2, and PKD3 are expressed in primary sensory neurons that mediate neurogenic inflammation and pain transmission, and PAR(2) agonists activate PKDs in HEK293 cells and DRG neurons in culture and in intact animals. PKD may be a novel component of a signal transduction pathway for protease-induced activation of nociceptive neurons and an important new target for antiinflammatory and analgesic therapies.
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Affiliation(s)
- Silvia Amadesi
- Center for Neurobiology of Digestive Diseases, University of California, San Francisco, San Francisco, California 94143-0660, USA
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Tan M, Hao F, Xu X, Chisolm GM, Cui MZ. Lysophosphatidylcholine activates a novel PKD2-mediated signaling pathway that controls monocyte migration. Arterioscler Thromb Vasc Biol 2009; 29:1376-82. [PMID: 19520973 PMCID: PMC3073140 DOI: 10.1161/atvbaha.109.191585] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Monocyte activation and migration are crucial events in the development of atherosclerosis and other inflammatory diseases. This study examined the role of protein kinase D (PKD) in monocyte migration. Method and Results- PKD2 is the predominant isoform of PKD expressed in monocytic THP-1 cells and primary human monocytes. Lysophosphatidylcholine (lysoPC), a prominent component of oxidized low-density lipoprotein, induces rapid and marked PKD activation in these cells. Using multiple approaches, including dominant-negative mutants and small interfering RNA knock-down, we found that lysoPC-induced PKD2 activation was required for the activation of both ERK and p38 MAPK. p38 MAPK mediation of lysoPC-induced monocytic cell migration was reported previously; our results reveal that the lysoPC-induced PKD2-p38 pathway controls monocyte migration. CONCLUSIONS This study provides the first evidence that (1) lysoPC activates PKD, (2) PKD2 has a novel role in p38 activation, and (3) the PKD2-activated p38 pathway is responsible for lysoPC-induced migration of THP-1 cells and human monocytes. Thus, PKD is a novel and functional intracellular regulator in both lysoPC signaling and monocyte migration. These results suggest a new role for PKD2 in the development of atherosclerosis and other inflammatory diseases.
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Affiliation(s)
- Mingqi Tan
- Department of Pathobiology, University of Tennessee College of Veterinary Medicine, Knoxville, TN 37996, USA
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Koncz P, Szanda G, Fülöp L, Rajki A, Spät A. Mitochondrial Ca2+ uptake is inhibited by a concerted action of p38 MAPK and protein kinase D. Cell Calcium 2009; 46:122-9. [DOI: 10.1016/j.ceca.2009.06.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Revised: 06/05/2009] [Accepted: 06/20/2009] [Indexed: 10/20/2022]
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Berna MJ, Tapia JA, Sancho V, Thill M, Pace A, Hoffmann KM, Gonzalez-Fernandez L, Jensen RT. Gastrointestinal growth factors and hormones have divergent effects on Akt activation. Cell Signal 2009; 21:622-38. [PMID: 19166928 PMCID: PMC2677382 DOI: 10.1016/j.cellsig.2009.01.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 12/16/2008] [Accepted: 01/02/2009] [Indexed: 12/11/2022]
Abstract
Akt is a central regulator of apoptosis, cell growth and survival. Growth factors and some G-protein-coupled receptors (GPCR) regulate Akt. Whereas growth-factor activation of Akt has been extensively studied, the regulation of Akt by GPCR's, especially gastrointestinal hormones/neurotransmitters, remains unclear. To address this area, in this study the effects of GI growth factors and hormones/neurotransmitters were investigated in rat pancreatic acinar cells which are high responsive to these agents. Pancreatic acini expressed Akt and 5 of 7 known pancreatic growth-factors stimulate Akt phosphorylation (T308, S473) and translocation. These effects are mediated by p85 phosphorylation and activation of PI3K. GI hormones increasing intracellular cAMP had similar effects. However, GI-hormones/neurotransmitters [CCK, bombesin, carbachol] activating phospholipase C (PLC) inhibited basal and growth-factor-stimulated Akt activation. Detailed studies with CCK, which has both physiological and pathophysiological effects on pancreatic acinar cells at different concentrations, demonstrated CCK has a biphasic effect: at low concentrations (pM) stimulating Akt by a Src-dependent mechanism and at higher concentrations (nM) inhibited basal and stimulated Akt translocation, phosphorylation and activation, by de-phosphorylating p85 resulting in decreasing PI3K activity. This effect required activation of both limbs of the PLC-pathway and a protein tyrosine phosphatase, but was not mediated by p44/42 MAPK, Src or activation of a serine phosphatase. Akt inhibition by CCK was also found in vivo and in Panc-1 cancer cells where it inhibited serum-mediated rescue from apoptosis. These results demonstrate that GI growth factors as well as gastrointestinal hormones/neurotransmitters with different cellular basis of action can all regulate Akt phosphorylation in pancreatic acinar cells. This regulation is complex with phospholipase C agents such as CCK, because both stimulatory and inhibitory effects can be seen, which are mediated by different mechanisms.
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Affiliation(s)
- Marc J. Berna
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1804, USA
- Universitätsklinikum Eppendorf, Medizinische Klinik I, 20246 Hamburg, Germany
| | - Jose A. Tapia
- Departamento de Fisiologia, Universidad de Extremadura, Cáceres 10071, Spain
| | - Veronica Sancho
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1804, USA
| | - Michelle Thill
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892
- Universitätsklinikum Eppendorf, Klinik und Poliklinik für Augenheilkunde, 20246 Hamburg, Germany
| | - Andrea Pace
- Universitätsklinikum Eppendorf, Medizinische Klinik I, 20246 Hamburg, Germany
| | - K. Martin Hoffmann
- Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Auenbruggerplatz 30, A-8036 Graz, Austria
| | | | - Robert T. Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1804, USA
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Chen LA, Li J, Silva SR, Jackson LN, Zhou Y, Watanabe H, Ives KL, Hellmich MR, Evers BM. PKD3 is the predominant protein kinase D isoform in mouse exocrine pancreas and promotes hormone-induced amylase secretion. J Biol Chem 2009; 284:2459-71. [PMID: 19028687 PMCID: PMC2629096 DOI: 10.1074/jbc.m801697200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Revised: 10/14/2008] [Indexed: 11/06/2022] Open
Abstract
The protein kinase D (PKD) family of serine/threonine kinases, which can be activated by gastrointestinal hormones, consists of three distinct isoforms that modulate a variety of cellular processes including intracellular protein transport as well as constitutive and regulated secretion. Although isoform-specific functions have been identified in a variety of cell lines, the expression and function of PKD isoforms in normal, differentiated secretory tissues is unknown. Here, we demonstrate that PKD isoforms are differentially expressed in the exocrine and endocrine cells of the pancreas. Specifically, PKD3 is the predominant isoform expressed in exocrine cells of the mouse and human pancreas, whereas PKD1 and PKD2 are more abundantly expressed in the pancreatic islets. Within isolated mouse pancreatic acinar cells, PKD3 undergoes rapid membrane translocation, trans-activating phosphorylation, and kinase activation after gastrointestinal hormone or cholinergic stimulation. PKD phosphorylation in pancreatic acinar cells occurs viaaCa2+-independent, diacylglycerol- and protein kinase C-dependent mechanism. PKD phosphorylation can also be induced by physiologic concentrations of secretagogues and by in vivo stimulation of the pancreas. Furthermore, activation of PKD3 potentiates MEK/ERK/RSK (RSK, ribosomal S6 kinase) signaling and significantly enhances cholecystokinin-mediated pancreatic amylase secretion. These findings reveal a novel distinction between the exocrine and endocrine cells of the pancreas and further identify PKD3 as a signaling molecule that promotes hormone-stimulated amylase secretion.
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Affiliation(s)
- L Andy Chen
- Department of Surgery and Sealy Center for Cancer Cell Biology, The University of Texas Medical Branch, Galveston, Texas 77555-0536, USA
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Yuan J, Lugea A, Zheng L, Gukovsky I, Edderkaoui M, Rozengurt E, Pandol SJ. Protein kinase D1 mediates NF-kappaB activation induced by cholecystokinin and cholinergic signaling in pancreatic acinar cells. Am J Physiol Gastrointest Liver Physiol 2008; 295:G1190-201. [PMID: 18845574 PMCID: PMC2604803 DOI: 10.1152/ajpgi.90452.2008] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Accepted: 10/05/2008] [Indexed: 02/07/2023]
Abstract
The transcription factor NF-kappaB plays a critical role in inflammatory and cell death responses during acute pancreatitis. Previous studies in our laboratory demonstrated that protein kinase C (PKC) isoforms PKCdelta and epsilon are key regulators of NF-kappaB activation induced by cholecystokinin-8 (CCK-8), tumor necrosis factor-alpha, and ethanol. However, the downstream participants in regulating NF-kappaB activation in exocrine pancreas remain poorly understood. Here, we demonstrate that protein kinase D1 (PKD1) is a key downstream target of PKCdelta and PKCepsilon in pancreatic acinar cells stimulated by two major secretagogues, CCK-8 and the cholinergic agonist carbachol (CCh), and that PKD1 is necessary for NF-kappaB activation induced by CCK-8 and CCh. Both CCK-8 and CCh dose dependently induced a rapid and striking activation of PKD1 in rat pancreatic acinar cells, as measured by in vitro kinase assay and by phosphorylation at PKD1 activation loop (Ser744/748) or autophosphorylation site (Ser916). The phosphorylation and activation of PKD1 correlated with NF-kappaB activity stimulated by CCK-8 or CCh, as measured by NF-kappaB DNA binding. Either inhibition of PKCdelta or epsilon by isoform-specific inhibitory peptides, genetic deletion of PKCdelta and epsilon in pancreatic acinar cells, or knockdown of PKD1 by using small interfering RNAs in AR42J cells resulted in a marked decrease in PKD1 and NF-kappaB activation stimulated by CCK-8 or CCh. Conversely, overexpression of PKD1 resulted in augmentation of CCK-8- and CCh-stimulated NF-kappaB activation. Finally, the kinetics of PKD1 and NF-kappaB activation during cerulein-induced rat pancreatitis showed that both PKD1 and NF-kappaB activation were early events during acute pancreatitis and that their time courses of response were similar. Our results identify PKD1 as a novel early convergent point for PKCdelta and epsilon in the signaling pathways mediating NF-kappaB activation in pancreatitis.
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Affiliation(s)
- Jingzhen Yuan
- Veterans Affairs Greater Los Angeles Healthcare System, West Los Angeles VA Healthcare Center, Los Angeles, CA 90073, USA.
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Receptor-mediated signal transduction pathways and the regulation of pancreatic acinar cell function. Curr Opin Gastroenterol 2008; 24:573-9. [PMID: 19122497 DOI: 10.1097/mog.0b013e32830b110c] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Recent studies on pancreatic acinar cell function have led to a more detailed understanding of the signal transduction mechanisms regulating digestive enzyme synthesis and secretion as well as pancreatic growth. This review identifies and puts into context these recent studies, which further understanding in these areas. RECENT FINDINGS Receptors present on acinar cells, particularly those for cholecystokinin and secretin, have been better characterized as to the molecular nature of the ligand-receptor interaction. Other reports have described the receptors for natriuretic peptides and fibroblast growth factor on acini. Intracellular Ca(2+) signaling remains at the center of stimulus secretion coupling and its regulation by inositol 1,4,5-trisphosphate, nicotinic acid adenine dinucleotide phosphate and cyclic ADP-ribose has been further defined. Work downstream of intracellular mediators has focused on molecular mechanisms of exocytosis particularly involving small G proteins, soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and cytoskeletal proteins. Considerable progress has been made defining the complex in acinar cells and its regulation. In addition to secretion, recent studies have further defined the regulation of pancreatic growth both in adaptive regulation to diet and hormones, particularly cholecystokinin, and in the regeneration that occurs after pancreatitis or partial pancreatectomy. This regulation involves calcineurin-nuclear factor of activated T cells, mammalian target of rapamycin, mitogen-activated protein kinase, Notch signaling pathways as well as various tyrosine kinases. SUMMARY Understanding the mechanisms that regulate pancreatic acinar cell function is contributing to our knowledge of normal pancreatic function and alterations in diseases such as pancreatitis and pancreatic cancer.
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Thrower EC, Osgood S, Shugrue CA, Kolodecik TR, Chaudhuri AM, Reeve JR, Pandol SJ, Gorelick FS. The novel protein kinase C isoforms -delta and -epsilon modulate caerulein-induced zymogen activation in pancreatic acinar cells. Am J Physiol Gastrointest Liver Physiol 2008; 294:G1344-53. [PMID: 18388183 PMCID: PMC2975015 DOI: 10.1152/ajpgi.00020.2008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Isoforms of protein kinase C (PKC) have been shown to modulate some cellular responses such as pathological secretion and generation of inflammatory mediators during acute pancreatitis (AP). We propose that PKC also participates in premature zymogen activation within the pancreatic acinar cell, a key event in the initiation of AP. This hypothesis was examined in in vivo and cellular models of caerulein-induced AP using PKC activators and inhibitors. Phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA, 200 nM), a known activator of PKC, enhanced zymogen activation at both 0.1 nM and 100 nM caerulein, concentrations which mimic physiological and supraphysiological effects of the hormone cholecystokinin, respectively, in preparations of pancreatic acinar cells. Isoform-specific PKC inhibitors for PKC-delta and PKC-epsilon reduced supraphysiological caerulein-induced zymogen activation. Using a cell-free reconstitution system, we showed that inhibition of PKC-delta and -epsilon, reduced zymogen activation in both zymogen granule-enriched and microsomal fractions. In dispersed acinar cells, 100 nM caerulein stimulation caused PKC-delta and -epsilon isoform translocation to microsomal membranes using cell fractionation and immunoblot analysis. PKC translocation was confirmed with in vivo studies and immunofluorescence microscopy in pancreatic tissues from rats treated with or without 100 nM caerulein. PKC-epsilon redistributed from an apical to a supranuclear region following caerulein administration. The signal for PKC-epsilon overlapped with granule membrane protein, GRAMP-92, an endosomal/lysosomal marker, in a supranuclear region where zymogen activation takes place. These results indicate that PKC-delta and -epsilon isoforms translocate to specific acinar cell compartments and modulate zymogen activation.
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Affiliation(s)
- Edwin C Thrower
- Department of Internal Medicine, Section of Digestive Diseases, Veterans Affairs Connecticut Healthcare of West Haven, West Haven, CT 06516, USA.
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Bibliography. Current world literature. Growth and development. Curr Opin Endocrinol Diabetes Obes 2008; 15:79-101. [PMID: 18185067 DOI: 10.1097/med.0b013e3282f4f084] [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: 11/25/2022]
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50
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Meyerholz DK, Samuel I. Morphologic characterization of early ligation-induced acute pancreatitis in rats. Am J Surg 2007; 194:652-8. [PMID: 17936429 PMCID: PMC2128702 DOI: 10.1016/j.amjsurg.2007.07.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Revised: 07/30/2007] [Accepted: 07/30/2007] [Indexed: 01/03/2023]
Abstract
BACKGROUND Bile-pancreatic duct ligation in rats causes acute pancreatic inflammation. We performed serial morphologic evaluation of the exocrine pancreas after duct ligation to facilitate further investigations using the model. METHODS The pancreas was excised from 74 rats after 0, 1, 3, 5, 24 or 48 hours of duct ligation or sham surgery. A pathologist evaluated 1 hematoxylin- and eosin-stained slide from each rat. Confirmatory immunostaining was performed with markers for apoptosis (activated caspase-3), proliferation (cyclin D3), neutrophils (myeloperoxidase), and macrophages (CD68). RESULTS Interstitial edema and white blood cell infiltration were apparent at 24 hours and increased at 48 hours. Progressive periods of duct ligation were characterized by ductular ectasia (1 to 3 hours), acinar vacuolization (5 to 48 hours), leukocytic margination and neutrophil exocytosis (5 to 48 hours), ductule epithelium hypertrophy and proliferation (24 to 48 hours), and discernible loss of zymogen granules (48 hours). CONCLUSIONS Ligation-induced acute pancreatitis in rats is a useful model to investigate early events in disease pathogenesis.
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Affiliation(s)
- David K Meyerholz
- Department of Pathology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA 52242, USA
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