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Moody TW, Ramos-Alvarez I, Jensen RT. Bombesin, endothelin, neurotensin and pituitary adenylate cyclase activating polypeptide cause tyrosine phosphorylation of receptor tyrosine kinases. Peptides 2021; 137:170480. [PMID: 33385499 DOI: 10.1016/j.peptides.2020.170480] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 12/12/2022]
Abstract
Numerous peptides including bombesin (BB), endothelin (ET), neurotensin (NTS) and pituitary adenylate cyclase-activating polypeptide (PACAP) are growth factors for lung cancer cells. The peptides bind to G protein-coupled receptors (GPCRs) resulting in elevated cAMP and/or phosphatidylinositol (PI) turnover. In contrast, growth factors such as epidermal growth factor (EGF) or neuregulin (NRG)-1 bind to receptor tyrosine kinases (RTKs) such as the EGFR or HER3, increasing tyrosine kinase activity, resulting in the phosphorylation of protein substrates such as PI3K or phospholipase (PL)C. Peptide GPCRs can transactivate numerous RTKs, especially members of the EGFR/HER family resulting in increased phosphorylation of ERK, leading to cellular proliferation or increased phosphorylation of AKT, leading to cellular survival. GRCR antagonists and tyrosine kinase inhibitors are useful agents to prevent RTK transactivation and inhibit proliferation of cancer cells.
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Affiliation(s)
- Terry W Moody
- Department of Health and Human Services, National Institutes of Health, National Cancer Institute, Center for Cancer Training, Bethesda, MD, 20892, USA.
| | - Irene Ramos-Alvarez
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, 9000 Rockville Pike, Bethesda, MD, 20892 USA
| | - Robert T Jensen
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, 9000 Rockville Pike, Bethesda, MD, 20892 USA
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2
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Moody TW, Lee L, Jensen RT. The G Protein–Coupled Receptor PAC1 Regulates Transactivation of the Receptor Tyrosine Kinase HER3. J Mol Neurosci 2020; 71:1589-1597. [DOI: 10.1007/s12031-020-01711-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/14/2020] [Indexed: 11/30/2022]
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Moody TW, Lee L, Iordanskaia T, Ramos-Alvarez I, Moreno P, Boudreau HE, Leto TL, Jensen RT. PAC1 regulates receptor tyrosine kinase transactivation in a reactive oxygen species-dependent manner. Peptides 2019; 120:170017. [PMID: 30273693 PMCID: PMC6438776 DOI: 10.1016/j.peptides.2018.09.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/10/2018] [Accepted: 09/19/2018] [Indexed: 11/22/2022]
Abstract
Pituitary adenylate cyclase activating polypeptide (PACAP) is a growth factor for lung cancer cells. PACAP-27 or PACAP-38 binds with high affinity to non-small cell lung cancer (NSCLC) cells, causing elevated cytosolic Ca2+, increased proliferation and increased phosphorylation of extracellular regulated kinase (ERK) and the epidermal growth factor receptor (EGFR). The role of reactive oxygen species (ROS) was investigated in these processes. Addition of PACAP-38 to NCI-H838 or A549 cells increased the tyrosine phosphorylation of the EGFR, HER2 and ERK significantly by 4-, 3-, and 2-fold, respectively. The transactivation of the EGFR and HER2 was inhibited by gefitinib or lapatinib (tyrosine kinase inhibitors), PACAP (6-38) (PAC1 antagonist), N-acetylcysteine (NAC is an anti-oxidant) or dipheyleneiodonium (DPI is an inhibitor of Nox and Duox enzymes). PACAP-38 addition to NSCLC cells increased ROS which was inhibited by PACAP (6-38), NAC or DPI. Nox1, Nox2, Nox3, Nox4, Nox5, Duox1 and Duox2 mRNA was present in many NSCLC cell lines. PACAP-38 stimulated the growth of NSCLC cells whereas PACAP (6-38), gefitinib or DPI inhibited proliferation. The results show that ROS are essential for PAC1 to regulate EGFR and HER2 transactivation as well as proliferation of NSCLC cells.
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Affiliation(s)
- Terry W Moody
- Department of Health and Human Services, National Institutes of Health, National Cancer Institute, Center for Cancer Research, 9609 Medical Center Drive, Room 2W-340, Bethesda, MD, 20892, USA.
| | - Lingaku Lee
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, 9000 Rockville Pike, Bethesda, MD, 20892, USA
| | - Tatiana Iordanskaia
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, 9000 Rockville Pike, Bethesda, MD, 20892, USA
| | - Irene Ramos-Alvarez
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, 9000 Rockville Pike, Bethesda, MD, 20892, USA
| | - Paola Moreno
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, 9000 Rockville Pike, Bethesda, MD, 20892, USA
| | - Howard E Boudreau
- National Institute of Allergy and Infectious Diseases, Lab. Host Defenses, 12441 Parklawn Dr., Rockville, MD, 20852, USA
| | - Thomas L Leto
- National Institute of Allergy and Infectious Diseases, Lab. Host Defenses, 12441 Parklawn Dr., Rockville, MD, 20852, USA
| | - Robert T Jensen
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, 9000 Rockville Pike, Bethesda, MD, 20892, USA
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Moody TW, Osefo N, Nuche-Berenguer B, Ridnour L, Wink D, Jensen RT. Pituitary adenylate cyclase-activating polypeptide causes tyrosine phosphorylation of the epidermal growth factor receptor in lung cancer cells. J Pharmacol Exp Ther 2012; 341:873-81. [PMID: 22389426 DOI: 10.1124/jpet.111.190033] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is an autocrine growth factor for some lung cancer cells. The activated PACAP receptor (PAC1) causes phosphatidylinositol turnover, elevates cAMP, and increases the proliferation of lung cancer cells. PAC1 and epidermal growth factor receptor (EGFR) are present in non-small-cell lung cancer (NSCLC) cells, and the growth of NSCLC cells is inhibited by the PAC1 antagonist PACAP(6-38) and the EGFR tyrosine kinase inhibitor gefitinib. Here, the ability of PACAP to transactivate the EGFR was investigated. Western blot analysis indicated that the addition of PACAP but not the structurally related vasoactive intestinal peptide increased EGFR tyrosine phosphorylation in NCI-H838 or H345 cells. PACAP-27, in a concentration-dependent manner, increased EGFR transactivation 4-fold 2 min after addition to NCI-H838 cells. The ability of 100 nM PACAP-27 to increase EGFR or extracellular signal-regulated kinase tyrosine phosphorylation in NCI-H838 cells was inhibited by PACAP(6-38), gefitinib, 4-amino-5-(4-chlorophenyl)-7-(dimethylethyl)pyrazolo[3,4-d]pyrimidine (PP2; Src inhibitor), (R)-N4-hydroxy-N1-[(S)-2-(1H-indol-3-yl)-1-methylcarbamoyl-ethyl]-2-isobutyl-succinamide (GM6001; matrix metalloprotease inhibitor), or antibody to transforming growth factor α (TGFα). By enzyme-linked immunosorbent assay, PACAP addition to NCI-H838 cells increased TGFα secretion into conditioned media. EGFR transactivation caused by the addition of PACAP to NCI-H838 cells was inhibited by N-acetyl-cysteine (antioxidant), tiron (superoxide scavenger), diphenylene iodonium (NADPH oxidase inhibitor), or 1-[6-[[(17β)-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U73122; phospholipase C inhibitor), but not N-[2-[[3-(4-bromophenyl)-2-propenyl]amino]ethyl]-5-isoquinolinesulfonamide (H89; protein kinase A inhibitor). PACAP addition to NCI-H838 cells significantly increased reactive oxygen species, and the increase was inhibited by tiron. The results indicate that PACAP causes transactivation of the EGFR in NSCLC cells in an oxygen-dependent manner that involves phospholipase C but not protein kinase A.
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Affiliation(s)
- Terry W Moody
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 31, Room 4A48, 31 Center Drive, Bethesda, MD 20892, USA.
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Pituitary adenylate cyclase-activating polypeptide causes increased tyrosine phosphorylation of focal adhesion kinase and paxillin. J Mol Neurosci 2011; 46:68-74. [PMID: 21898124 DOI: 10.1007/s12031-011-9639-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 08/21/2011] [Indexed: 01/04/2023]
Abstract
The effects of pituitary adenylate cyclase-activating polypeptide (PACAP) on tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin were investigated using lung cancer cells. Addition of PACAP-27 or PACAP-38 but not vasoactive intestinal peptide to NCI-H838 or NCI-H1299 human lung cancer cells significantly increased the tyrosine phosphorylation of FAK or paxillin. The increase in FAK or paxillin tyrosine phosphorylation caused by addition of PACAP-27 to NCI-H838 cells was inhibited by PACAP(6-38), a PAC1-receptor (R) antagonist. The increase in FAK or paxillin tyrosine phosphorylation caused by 100 nM PACAP-27 was maximal 2 min after addition to NCI-H838 cells. The effects of PACAP at stimulating FAK and paxillin tyrosine phosphorylation were reversed by cytochalasin D and genistein which inhibit actin polymerization and tyrosine kinase activity, respectively. The effects of PACAP at stimulating FAK and paxillin tyrosine phosphorylation were reversed by U-73122 but not H89 which inhibit phospholipase C and protein kinase A, respectively. The results show that PAC1-R regulates FAK and paxillin tyrosine phosphorylation in lung cancer cells as a result of increased phosphatidylinositol turnover but not adenylyl cylase stimulation.
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Yu SJ, Yu JK, Ge WT, Hu HG, Yuan Y, Zheng S. SPARCL1, Shp2, MSH2, E-cadherin, p53, ADCY-2 and MAPK are prognosis-related in colorectal cancer. World J Gastroenterol 2011; 17:2028-36. [PMID: 21528083 PMCID: PMC3082758 DOI: 10.3748/wjg.v17.i15.2028] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 12/17/2010] [Accepted: 12/24/2010] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the expression of markers that are correlated with the prognosis of colorectal cancer (CRC) patients.
METHODS: One hundred and fifty-six CRC patients were followed up for more than 3 years after radical surgery. Immunohistochemical (IHC) analysis was performed to detect the expression of 14 pathway-related markers (p53, APC, p21ras, E-cadherin, endothelin-B receptor, Shp2, ADCY-2, SPARCL1, neuroligin1, hsp27, mmp-9, MAPK, MSH2 and rho) in specimens from these patients. Bioinformatics analysis involving a Support Vector Machine (SVM) was used to determine the best prognostic model from combinations of these markers.
RESULTS: Seven markers (SPARCL1, Shp2, MSH2, E-cadherin, p53, ADCY-2 and MAPK) were significantly related to the prognosis and clinical pathological features of the CRC patients (P < 0.05). Prognostic models were established through SVM from combinations of these 7 markers and proved able to differentiate patients with dissimilar survival, especially in stage II/III patients. According to the best prognostic model, the p53/SPARCL1 model, patients having high p53 and low SPARCL1 expression had about 50% lower 3-year survival than others (P < 0.001).
CONCLUSION: SPARCL1, Shp2, MSH2, E-cadherin, p53, ADCY-2 and MAPK are potential prognostic markers in CRC. A p53/SPARCL1 bioinformatics model may be used as a supplement to tumor-nodes-metastasis staging.
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Vaudry D, Falluel-Morel A, Bourgault S, Basille M, Burel D, Wurtz O, Fournier A, Chow BKC, Hashimoto H, Galas L, Vaudry H. Pituitary Adenylate Cyclase-Activating Polypeptide and Its Receptors: 20 Years after the Discovery. Pharmacol Rev 2009; 61:283-357. [DOI: 10.1124/pr.109.001370] [Citation(s) in RCA: 829] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Torrisani J, Bournet B, du Rieu MC, Bouisson M, Souque A, Escourrou J, Buscail L, Cordelier P. let-7 MicroRNA Transfer in Pancreatic Cancer-Derived Cells Inhibits In Vitro Cell Proliferation but Fails to Alter Tumor Progression. Hum Gene Ther 2009; 20:831-44. [DOI: 10.1089/hum.2008.134] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Jérôme Torrisani
- Institut National de la Santé et de la Recherche Médicale Unité 858-12MR, Institut de Médecine Moléculaire de Rangueil, Département Cancers Epithéliaux, Angiogénèse et Signalisation, 31432 Toulouse Cedex 4, France
| | - Barbara Bournet
- Institut National de la Santé et de la Recherche Médicale Unité 858-12MR, Institut de Médecine Moléculaire de Rangueil, Département Cancers Epithéliaux, Angiogénèse et Signalisation, 31432 Toulouse Cedex 4, France
- Service de Gastro-Entérologie et de Nutrition Centre Hospitalier Universitaire Rangeuil, 31059 Toulouse, France
| | - Maël Chalret du Rieu
- Institut National de la Santé et de la Recherche Médicale Unité 858-12MR, Institut de Médecine Moléculaire de Rangueil, Département Cancers Epithéliaux, Angiogénèse et Signalisation, 31432 Toulouse Cedex 4, France
| | - Michèle Bouisson
- Institut National de la Santé et de la Recherche Médicale Unité 858-12MR, Institut de Médecine Moléculaire de Rangueil, Département Cancers Epithéliaux, Angiogénèse et Signalisation, 31432 Toulouse Cedex 4, France
| | - Anny Souque
- Institut National de la Santé et de la Recherche Médicale Unité 858-12MR, Institut de Médecine Moléculaire de Rangueil, Département Cancers Epithéliaux, Angiogénèse et Signalisation, 31432 Toulouse Cedex 4, France
| | - Jean Escourrou
- Service de Gastro-Entérologie et de Nutrition Centre Hospitalier Universitaire Rangeuil, 31059 Toulouse, France
| | - Louis Buscail
- Institut National de la Santé et de la Recherche Médicale Unité 858-12MR, Institut de Médecine Moléculaire de Rangueil, Département Cancers Epithéliaux, Angiogénèse et Signalisation, 31432 Toulouse Cedex 4, France
- Service de Gastro-Entérologie et de Nutrition Centre Hospitalier Universitaire Rangeuil, 31059 Toulouse, France
| | - Pierre Cordelier
- Institut National de la Santé et de la Recherche Médicale Unité 858-12MR, Institut de Médecine Moléculaire de Rangueil, Département Cancers Epithéliaux, Angiogénèse et Signalisation, 31432 Toulouse Cedex 4, France
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Abstract
This review article has for major objective to summarize the old and latest developments on the hormonal controls of pancreatic growth. The article deals with hormonal controls during the fetal, neonatal and adult periods of pancreas development, growth and regeneration. During the fetal period, comparisons were made between studies performed with pancreatic explants and those designed in vivo. After birth, the effects of glucocorticoids, thyroxine, gastrin, bombesin, secretin, cholecystokinin alone or with secretin are reported. In the adults, similar studies were reported on hormones with addition of the effects of neuropeptides, the cell types targeted by hormones and the hormonal control after pancreatectomy and pancreatitis.
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Winzell MS, Ahrén B. Role of VIP and PACAP in islet function. Peptides 2007; 28:1805-13. [PMID: 17559974 DOI: 10.1016/j.peptides.2007.04.024] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Revised: 04/16/2007] [Accepted: 04/24/2007] [Indexed: 01/09/2023]
Abstract
Vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) are two closely related neuropeptides that are expressed in islets and in islet parasympathetic nerves. Both peptides bind to their common G-protein-coupled receptors, VPAC1 and VPAC2, and PACAP, in addition to the specific receptor PAC1, all three of which are expressed in islets. VIP and PACAP stimulate insulin secretion in a glucose-dependent manner and they both also stimulate glucagon secretion. This action is achieved through increased formation of cAMP after activation of adenylate cyclase and stimulation of extracellular calcium uptake. Deletion of PAC1 receptors or VPAC2 receptors results in glucose intolerance. These peptides may be of importance in mediating prandial insulin secretion and the glucagon response to hypoglycemia. Animal studies have also suggested that activation of the receptors, in particular VPAC2 receptors, may be used as a therapeutic approach for the treatment of type 2 diabetes. This review summarizes the current knowledge of the potential role of VIP and PACAP in islet function.
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Affiliation(s)
- Maria Sörhede Winzell
- Department of Clinical Sciences, Division of Medicine, Lund University, BMC, B11, SE-221 84 Lund, Sweden.
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The Biological Significance of PACAP and PACAP Receptors in Human Tumors: From Cell Lines to Cancers. PITUITARY ADENYLATE CYCLASE-ACTIVATING POLYPEPTIDE 2003. [DOI: 10.1007/978-1-4615-0243-2_17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Le SV, Yamaguchi DJ, McArdle CA, Tachiki K, Pisegna JR, Germano P. PAC1 and PACAP expression, signaling, and effect on the growth of HCT8, human colonic tumor cells. REGULATORY PEPTIDES 2002; 109:115-25. [PMID: 12409223 PMCID: PMC6736540 DOI: 10.1016/s0167-0115(02)00194-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The pituitary adenylate cyclase-activating polypeptide (PACAP) type 1 receptor (PAC1) is a heptahelical, G protein-coupled receptor that has been shown to be expressed by non-squamous lung cancer and breast cancer cell lines, and to be coupled to the growth of these tumors. We have previously shown that PACAP and its receptor, PAC1, are expressed in rat colonic tissue. In this study, we used polyclonal antibodies directed against the COOH terminal of PAC1, as well as fluorescently labeled PACAP, Fluor-PACAP, to demonstrate the expression of PAC1 on HCT8 human colonic tumor cells, using FACS analysis and confocal laser scanning microscopy. Similarly, anti-PACAP polyclonal antibodies were used to confirm the expression of PACAP hormone by this cell line. We then investigated the signal transduction properties of PAC1 in these tumor cells. PACAP-38 elevated intracellular cAMP levels in a dose-dependent manner, with a half-maximal (EC(50)) stimulation of approximately 3 nM. In addition, PACAP-38 stimulation caused an increase in cytosolic Ca(2+) concentration [Ca(2+)](i), which was partially inhibited by the PACAP antagonist, PACAP-(6-38). Finally, we studied the potential role of PACAP upon the growth of these tumor cells. We found that PACAP-38, but not VIP, increased the number of viable HCT8 cells, as measured by MTT activity. We also demonstrated that HCT8 cells expressed the Fas receptor (Fas-R/CD95), which was subsequently down-regulated upon activation with PACAP-38, further suggesting a possible role for PACAP in the growth and survival of these tumor cells. These data indicate that HCT8 human colon tumor cells express PAC1 and produce PACAP hormone. Furthermore, PAC1 activation is coupled to adenylate cyclase, increase cytosolic [Ca(2+)](i), and cellular proliferation. Therefore, PACAP is capable of increasing the number of viable cells and regulating Fas-R expression in a human colonic cancer cell line, suggesting that PACAP might play a role in the regulation of colon cancer growth and modulation of T lymphocyte anti-tumoral response via the Fas-R/Fas-L apoptotic pathway.
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Affiliation(s)
- Sang V. Le
- CURE: Digestive Diseases Research Center, VA Greater Los Angeles Healthcare System, University of California, Los Angeles, Los Angeles, CA 90073, USA
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90073, USA
| | - Dean J. Yamaguchi
- CURE: Digestive Diseases Research Center, VA Greater Los Angeles Healthcare System, University of California, Los Angeles, Los Angeles, CA 90073, USA
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90073, USA
| | - Craig A. McArdle
- Research Centre for Neuroendocrinology, University of Bristol, Marlborough Street, Bristol BS2 8HW, United Kingdom
| | - Ken Tachiki
- CURE: Digestive Diseases Research Center, VA Greater Los Angeles Healthcare System, University of California, Los Angeles, Los Angeles, CA 90073, USA
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90073, USA
| | - Joseph R. Pisegna
- CURE: Digestive Diseases Research Center, VA Greater Los Angeles Healthcare System, University of California, Los Angeles, Los Angeles, CA 90073, USA
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90073, USA
| | - Patrizia Germano
- CURE: Digestive Diseases Research Center, VA Greater Los Angeles Healthcare System, University of California, Los Angeles, Los Angeles, CA 90073, USA
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90073, USA
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13
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Läuffer JM, Tang LH, Zhang T, Hinoue T, Rahbar S, Odo M, Modlin IM, Kidd M. PACAP mediates the neural proliferative pathway of Mastomys enterochromaffin-like cell transformation. REGULATORY PEPTIDES 2001; 102:157-64. [PMID: 11730988 DOI: 10.1016/s0167-0115(01)00314-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND AIM Pituitary adenylate-cyclase activating peptide (PACAP) is a more potent proliferative agent than gastrin for rat enterochromaffin-like (ECL) cell proliferation in vitro. The role of this neurotransmitter during gastrin-mediated ECL cell tumor formation and gastrin-autonomous ECL cell neoplasia is unknown. METHODS AND RESULTS ECL cell transformation was induced in the Mastomys using 16 wk H2 receptor blockade of acid inhibition. Examination of the epithelial fundic mucosa demonstrated that PACAP-immunoreactivity significantly increased in the tumor mucosa compared to the naïve stomach, and was associated with ECL cells. Naïve and tumor ECL cells were then purified (approximately 95%) from Mastomys and the presence of all three PACAP/VPAC receptor subtypes was demonstrated by polymerase chain-reaction amplification. Thereafter, cells were maintained in short-term (48 h) primary cultures. PACAP significantly (p<0.05) increased 24 h bromo-deoxyuridine uptake (approximately 4-fold) in both cell types with estimated EC(50) values of approximately 4x10(-16) M and approximately 2x10(-16) M, respectively. Specific receptor antagonists (PAC1/VPAC1) of PACAP competitively inhibited these proliferative effects in naïve cells. Oligonucleotide antisense directed against PAC1 significantly inhibited PACAP-stimulated DNA synthesis by approximately 85% (p<0.05) in tumor cells. CONCLUSION PACAP is a potent and effective modulator of ECL cell proliferation. The expression of this neuropeptide and its receptors, particularly PAC1, suggest the existence of a neural regulatory pathway of ECL cell proliferation and transformation.
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MESH Headings
- Animals
- Cell Division/drug effects
- Cell Transformation, Neoplastic/drug effects
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Cells, Cultured
- DNA/biosynthesis
- Enterochromaffin-like Cells/metabolism
- Enterochromaffin-like Cells/pathology
- Gastric Mucosa/drug effects
- Gastric Mucosa/innervation
- Gastric Mucosa/metabolism
- Gastric Mucosa/pathology
- Humans
- Microscopy, Fluorescence
- Muridae
- Neural Pathways/drug effects
- Neuropeptides/immunology
- Neuropeptides/metabolism
- Neuropeptides/pharmacology
- Pituitary Adenylate Cyclase-Activating Polypeptide
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I
- Receptors, Pituitary Hormone/antagonists & inhibitors
- Receptors, Pituitary Hormone/genetics
- Receptors, Pituitary Hormone/metabolism
- Receptors, Vasoactive Intestinal Polypeptide, Type I
- Reverse Transcriptase Polymerase Chain Reaction
- Stomach Neoplasms/metabolism
- Stomach Neoplasms/pathology
- Tumor Cells, Cultured
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Affiliation(s)
- J M Läuffer
- Surgical Gastric Pathobiology Research Group, Yale University School of Medicine, and West Haven Veterans Administration Medical Center, New Haven, CT 06520-8062, USA
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PISEGNA JOSEPHR, OHNING GORDONV, ATHMANN CHRISTOPHE, ZENG NINGXIN, WALSH JOHNH, SACHS GEORGE. Role of PACAP1 receptor in regulation of ECL cells and gastric acid secretion by pituitary adenylate cyclase activating peptide. Ann N Y Acad Sci 2000; 921:233-41. [PMID: 11193828 PMCID: PMC6736551 DOI: 10.1111/j.1749-6632.2000.tb06971.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We previously reported that PAC1 is expressed on ECL cells resulting in stimulation of [Ca2+]i, histamine and acid secretion. The study reported here characterized the signaling by PAC1 on ECL cells; determined the effects of PACAP on the gastric acid secretion in vivo, and determined the effects of chronic administration of PACAP-27 on ECL cell proliferation. PACAP-27 dose dependently stimulated ECL cell Ca2+ and AC with detectable stimulation at 1 nM and maximal stimulation at 100 nM (six-fold). In rats PACAP-27 administration (10 pmol/kg/h) increased the rate of gastric acid secretion when an antisomatostatin antibody was co-administered. Chronic administration of PACAP (10 pmol/h for seven days) via osmotic pump resulted in a more than twofold increase in BrdU incorporation into ECL cells. PACAP acting at the PAC1 results in dual signaling responses to both [Ca2+]i. AC in ECL cells stimulates gastric acid secretion via the actions of histamine acting at the parietal cell and in whole animals leads to proliferation of ECL cells when administered chronically.
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Affiliation(s)
- JOSEPH R. PISEGNA
- Address for correspondence: Joseph R. Pisegna, Chief, Gastroenterology and Hepatology (111C), VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA. Voice: 310-478-3711 ext. 41940; fax: 310-268-4096.
| | | | | | | | | | - GEORGE SACHS
- Address for correspondence: George Sachs, Wadsworth VA Hospital, Building 113, Room 326, Los Angeles, CA 90073, USA. Voice: 310-268-3923; fax: 310-312-9478.
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Bestervelt L, Barr B, Dethloff L. Divergent proliferative responses to a gastrin receptor ligand in synchronized and unsynchronized rat pancreatic AR42J tumour cells. Cell Signal 2000; 12:53-61. [PMID: 10676848 DOI: 10.1016/s0898-6568(99)00067-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Depending upon experimental model, the CCK-B/gastrin receptor ligand CI-988 exhibits either agonist or antagonist activity. To confirm that CI-988 behaves as an antagonist toward gastrin-stimulated growth, its effects on cell proliferation were investigated in unsynchronized and synchronized AR42J rat pancreatic tumour cells. In unsynchronized cultures CI-988 alone had no effect, but inhibited gastrin-stimulated cell proliferation. In contrast, in synchronized cultures, CI-988 stimulated cell proliferation. Similarly, CI-988 inhibited gastrin-stimulated cAMP production in unsynchronized cells, but stimulated cAMP formation in synchronized cultures. Therefore, CI-988 stimulation of cAMP production and proliferation in AR42J cell cultures appears to be cell cycle-dependent. CI-988 inhibited gastrin-stimulated intracellular calcium ([Ca2+]i) mobilization in both populations and thus acted as an antagonist toward this pathway. Because CCK receptor densities and affinities were similar in both cell populations, the data suggest that CI-988's divergent effects on cell proliferation are governed by postreceptor signalling events which vary with cell cycle.
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Affiliation(s)
- L Bestervelt
- Department of Pathology and Experimental Toxicology, Parke-Davis Pharmaceutical Research, Ann Arbor, MI 48105, USA
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16
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Nardone G, Rocco A, Balzano T, Budillon G. The efficacy of octreotide therapy in chronic bleeding due to vascular abnormalities of the gastrointestinal tract. Aliment Pharmacol Ther 1999; 13:1429-36. [PMID: 10571598 DOI: 10.1046/j.1365-2036.1999.00647.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND The treatment of angiodysplasia and watermelon stomach, vascular abnormalities implicated in gastrointestinal bleeding of obscure origin, is a major clinical problem. AIM To determine the efficacy of octreotide in patients with long-standing gastrointestinal bleeding due to acquired angiodysplasia and watermelon stomach, resistant to previous treatments and not suitable for surgery because of old age and/or concomitant disorders. PATIENTS AND METHODS We treated 17 patients (seven had isolated angiodysplasia, seven had multiple upper and lower gastrointestinal angiodysplasia, and three had watermelon stomach) with octreotide (0. 1 mg subcutaneous t.d.s. for 6 months). Six of the patients had liver cirrhosis, one had Glanzmann-type platelet derangement, two had cardiovascular diseases and one had chronic uraemia. RESULTS Octreotide treatment stopped bleeding in 10 patients. A transient improvement was observed in four, who needed subsequent cyclical retreatment to correct low haemoglobin levels. No effect was observed in three, probably due to the severity of the concomitant disorders. CONCLUSIONS Octreotide is a safe drug that may be useful to control the recurrent gastrointestinal bleeding due to acquired angiodysplasia and watermelon stomach, especially in patients who are not candidates for surgery due to old age and/or concomitant disorders.
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Affiliation(s)
- G Nardone
- Cattedra di Gastroenterologia, Università degli Studi 'Federico II', Naples, Italy.
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17
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Läuff JM, Modlin IM, Tang LH. Biological relevance of pituitary adenylate cyclase-activating polypeptide (PACAP) in the gastrointestinal tract. REGULATORY PEPTIDES 1999; 84:1-12. [PMID: 10535402 DOI: 10.1016/s0167-0115(99)00024-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Since its initial discovery in 1989, pituitary adenylate cyclase activating peptide (PACAP) has been noted to distribute widely in the brain, the respiratory and the gastrointestinal system. It occurs in two bioactive molecules, PACAP-27 and the C-terminally extended PACAP-38, which evoke activity by binding to three distinct types of high-affinity, G-protein coupled membrane receptors. It is present throughout the entirety of the gut but is rare in certain areas such as the intestinal mucosa and islets of Langerhans. PACAP-induced biological effects are protean and include alterations of motility in the bowel and the gallbladder, stimulation of gastric acid and intestinal secretion, hormone/enzyme release from the exocrine and endocrine pancreas, and the induction as well as inhibition of proliferation in neuroendocrine cells and tumors. Its hepatic activity has to date not been elucidated in detail. One of the interesting features of PACAP is the species and organ dependent variation of its biological effects. Of particular note is its superior potency when compared with other neuropeptides identified in the gut, and the involvement of a number of different second messenger systems upon PACAP receptor activation.
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Affiliation(s)
- J M Läuff
- Gastrointestinal Pathobiology Research Group, Yale University School of Medicine, New Haven, CT 06520-8062, USA
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18
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Läuffer JM, Modlin IM, Hinoue T, Kidd M, Zhang T, Schmid SW, Tang LH. Pituitary adenylate cyclase-activating polypeptide modulates gastric enterochromaffin-like cell proliferation in rats. Gastroenterology 1999; 116:623-35. [PMID: 10029621 DOI: 10.1016/s0016-5085(99)70184-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Gastric carcinoids (types I and II) involve the transformation of naive enterochromaffin-like (ECL) cells to the neoplastic state and are associated primarily with hypergastrinemia. In this study, we evaluated the effects of two related neuropeptides, pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP), on ECL cell proliferation and characterized the receptor subtype(s) and signal transduction pathways that mediate this effect. METHODS Purified rat ECL cells were analyzed in culture for DNA synthesis as measured by 24-hour 5-bromo-2-deoxyuridine (BrdU) uptake. Reverse-transcription polymerase chain reaction (RT-PCR) with gene-specific oligonucleotide primers was performed to characterize the PACAP/VIP receptor subtype(s). RESULTS PACAP/VIP neuropeptide-stimulated BrdU uptake was significantly greater (3.4-3.8-fold greater than control) than that at the maximal dose of gastrin (2.2-fold greater than control). PACAP-stimulated ECL cell proliferation (EC50, approximately 3 x 10(-)14 mol/L) was approximately 100-fold more potent than VIP (EC50, approximately 3x 10(-)12 mol/L). The stimulated BrdU uptake by both PACAP and VIP was competitively inhibited by PACAP-receptor antagonist (IC50, 10(-)9 mol/L, 3 x 10(-)9 mol/L, respectively) and VIP-receptor antagonist (IC50, 3 x 10(-)7 mol/L, 5 x 10(-)7 mol/L, respectively). RT-PCR identified the presence of the PACAP-specific but not PACAP/VIP receptor subtypes. The PACAP-stimulated BrdU uptake was inhibited (70%-80%) by inhibitors of adenosine 3',5'-cyclic monophosphate, phosphatidylinositol 3 kinase, and protein tyrosine kinase as well as mitogen-activated protein kinase. CONCLUSIONS PACAP/VIP-related peptides are more potent modulators of ECL cell proliferation than gastrin, and their effect is mediated by a PACAP-specific receptor whose activation is transduced by multiple intracellular messenger systems.
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Affiliation(s)
- J M Läuffer
- Gastric Pathobiology Research Group, Department of Surgery, Yale University School of Medicine and West Haven Veterans Administration Medical Center, New Haven, Connecticut, USA
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Schäfer H, Zheng J, Morys-Wortmann C, Fölsch UR, Schmidt WE. Structural motifs of pituitary adenylate cyclase-activating polypeptide (PACAP) defining PAC1-receptor selectivity. REGULATORY PEPTIDES 1999; 79:83-92. [PMID: 10100920 DOI: 10.1016/s0167-0115(98)00147-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) interacts with three types of PACAP/VIP-receptors. The PAC1-receptor accepts PACAP as a high affinity ligand but not vasoactive intestinal peptide (VIP) similarly binding to VPAC1- and VPAC2-receptors. To identify those amino acids not present in VIP defining PAC1-receptor selectivity of PACAP, radio receptor binding assays on AR4-2J cells were performed. It could be shown that PACAP(1-27) exhibited a distinct and much higher susceptibility to VIP-amino acid substitutions, compared to PACAP(1-38). Positions 4 and 5 seem to be most important for receptor binding of PACAP(1-27), whereas position 13 was identified to be crucial for maximal affinity of PACAP(1-38). PACAP(29-38) extension analogues of VIP revealed a stabilizing effect of the C-terminus of PACAP(1-38) on the optimal peptide conformation. The substitution analogues were also checked for their capacity to stimulate IP3 and cAMP formation in AR4-2J cells. Compared to PACAP(1-27) and PACAP(1-38), most analogues revealed potencies reduced congruously to their lower binding affinities. However, one of the analogues, PACAP(1-27) substituted in position 5, may represent a weak antagonist since this peptide was less potent in inducing second messengers than in label displacement. Our findings indicate that PACAP(1-27) and PACAP(1-38) differ in terms of their requirement of the amino acids in positions 4, 5, 9, 11 and 13 for maximal interaction with the PAC1-receptor.
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Affiliation(s)
- H Schäfer
- Laboratory of Molecular Gastroenterology and Hepatology, 1st Department of Internal Medicine, Christian-Albrechts-University of Kiel, Germany
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20
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Arimura A. Perspectives on pituitary adenylate cyclase activating polypeptide (PACAP) in the neuroendocrine, endocrine, and nervous systems. THE JAPANESE JOURNAL OF PHYSIOLOGY 1998; 48:301-31. [PMID: 9852340 DOI: 10.2170/jjphysiol.48.301] [Citation(s) in RCA: 421] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
PACAP is a pleiotropic neuropeptide that belongs to the secretin/glucagon/VIP family. PACAP functions as a hypothalamic hormone, neurotransmitter, neuromodulator, vasodilator, and neurotrophic factor. Its structure has been remarkably conserved during evolution. The PACAP receptor is G protein-coupled with seven transmembrane domains and also belongs to the VIP receptor family. PACAP, but not VIP, binds to PAC1-R, whereas PACAP and VIP bind to VPAC1-R and VPAC2-R with a similar affinity. Despite the sizable homology of the structures of PACAP and VIP and their receptors, the distribution of these peptides and receptors is quite different. At least eight subtypes of PACAP specific, or PAC1-R, result from alternate splicing. Each subtype is coupled with specific signaling pathways, and its expression is tissue or cell specific. Although PACAP fulfills most requirements for a physiological hypothalamic hypophysiotropic hormone, it does not consistently stimulate secretion of the adenohypophysial hormones, except for stimulation of IL-6 release from the FS cells of the pituitary. The major regulatory role of PACAP in pituitary cells appears to be the regulation of gene expression of pituitary hormones and/or regulatory proteins that control growth and differentiation of the pituitary glandular cells. These effects appear to be exhibited directly and indirectly through a paracrine or autocrine action. Although PACAP stimulates the release of AVP, the physiological role of neurohypophysial PACAP remains unknown. One important action of PACAP in the endocrine system is its role as a potent secretagogue for adrenaline from the adrenal medulla through activation of TH. PACAP also stimulates the release of insulin and increases [Ca2+]i from pancreatic beta-cells at an extremely small concentration. The stage-specific expression of PACAP in testicular germ cells during spermatogenesis suggests its regulatory role in the maturation of germ cells. In the ovary, PACAP is transiently expressed in the granulosa cells of the preovulatory follicles and appears to be involved in the LH-induced cellular events in the ovary, including prevention of follicular apoptosis. In the central nervous system, PACAP acts as a neurotransmitter or neuromodulator, which has been supported by IHC and electrophysiological methods. More important, PACAP is a neurotrophic factor that may play an important role during the development of the brain. In the adult brain, PACAP appears to function as a neuroprotective factor that attenuates the neuronal damage resulting from various insults.
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MESH Headings
- Adult
- Amino Acid Sequence
- Animals
- Endocrine Glands/drug effects
- Endocrine Glands/physiology
- Female
- Humans
- Male
- Molecular Sequence Data
- Nervous System/drug effects
- Nervous System Physiological Phenomena
- Neuropeptides/genetics
- Neuropeptides/pharmacology
- Neuropeptides/physiology
- Neurosecretory Systems/drug effects
- Neurosecretory Systems/physiology
- Ovary/drug effects
- Ovary/physiology
- Pituitary Adenylate Cyclase-Activating Polypeptide
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I
- Receptors, Pituitary Hormone/chemistry
- Receptors, Pituitary Hormone/genetics
- Receptors, Pituitary Hormone/physiology
- Receptors, Vasoactive Intestinal Peptide, Type II
- Receptors, Vasoactive Intestinal Polypeptide, Type I
- Sequence Homology, Amino Acid
- Signal Transduction
- Testis/drug effects
- Testis/physiology
- Tissue Distribution
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Affiliation(s)
- A Arimura
- Department of Medicine, Tulane University School of Medicine, New Orleans, LA, USA
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21
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Martinez C, Delgado M, Pozo D, Leceta J, Calvo JR, Ganea D, Gomariz RP. VIP and PACAP enhance IL-6 release and mRNA levels in resting peritoneal macrophages: in vitro and in vivo studies. J Neuroimmunol 1998; 85:155-67. [PMID: 9630164 DOI: 10.1016/s0165-5728(98)00018-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Vasoactive intestinal peptide (VIP), a neuropeptide produced by lymphocytes has been previously reported to modulate cytokine expression in T lymphocytes. In this study, we investigated the effects of VIP and of the structurally related neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP38) on the production of IL-6 in unstimulated murine peritoneal macrophages. Both neuropeptides stimulate rapidly, specifically, and similarly the production of IL-6, exerting their action through two different receptor/signal transduction systems, i.e., primarily through the binding to VIP1/PACAP receptor followed by adenylate cyclase activation, and partially through the activation of protein kinase C following binding to PACAP-R. VIP and PACAP38 regulate the production of IL-6 at a transcriptional level, affecting the de novo synthesis of this cytokine. The stimulatory in vitro effect correlates with the stimulation of IL-6 expression and release in vivo. These studies suggest that VIP/PACAP play a role in immune system homeostasis, participating in the intricate cytokine network and controlling local immune responses. In addition, the understanding of the factors that regulate the expression and release of IL-6 by macrophages is important for the elucidation of the role of IL-6 in health and disease.
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Affiliation(s)
- C Martinez
- Department of Cellular Biology, Faculty of Biology, Complutense University, Madrid, Spain
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22
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Lelièvre V, Meunier AC, Caigneaux E, Falcon J, Muller JM. Differential expression and function of PACAP and VIP receptors in four human colonic adenocarcinoma cell lines. Cell Signal 1998; 10:13-26. [PMID: 9502113 DOI: 10.1016/s0898-6568(97)00067-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Human colonic adenocarcinoma cell lines have conserved several features of the native tissue. Among these is the expression of cell surface receptors for hormones and neurotransmitters that may be involved in the regulation of proliferation and differentiation processes in these cancer cells. Here, we confirm that high-affinity binding sites for the Vasoactive Intestinal Polypeptide (VIP) and for the VIP analogue Pituitary Adenylate-Cyclase Activating Polypeptide (PACAP), were expressed in 4 human colonic adenocarcinoma cell lines, HT29, SW403, DLD-1 and Caco-2, that spontaneously displayed variable phenotypic properties in culture. We demonstrated that after long-term treatments, VIP and PACAP significantly reduced cell proliferation in the 4 cell lines and modulated intracellular cAMP and cGMP levels. Furthermore, conspicuous differences were observed from one cell type to another concerning expression of the receptor subsets or the effects of the neuropeptides on cell growth and on cyclic nucleotides production.
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Affiliation(s)
- V Lelièvre
- Laboratoire de Biologie des Interactions Cellulaires, CNRS UMR 6558, Université de Poitiers, Faculté des Sciences, France
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23
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Barnhart DC, Sarosi GA, Mulholland MW. PACAP-38 causes phospholipase C-dependent calcium signaling in rat acinar cell line. Surgery 1997; 122:465-74; discussion 474-5. [PMID: 9288154 DOI: 10.1016/s0039-6060(97)90040-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Pituitary adenylate cyclase activating peptide (PACAP-38), a neuropeptide of the vasoactive intestinal peptide/secretin family, localizes to intrapancreatic neurons and stimulates exocrine secretion from the pancreas. PACAP-38 stimulates calcium signaling in the rat pancreatic cell line AR42J. The purpose of this study was to elucidate the mechanisms of PACAP-evoked calcium signaling in these cells. METHODS Continuous measurements of intracellular calcium were taken by fluorescent digital microscopy with the dye fura-2. Mechanisms of PACAP-38-evoked calcium signals were determined by a panel of inhibitors. Inositol phosphates production in response to PACAP-38 was measured. The ability of PACAP-38 to stimulate amylase release was used to determine a relevant dose range for these studies. RESULTS We have shown that (1) AR42J cells respond to PACAP-38 with biphasic increases in [Ca2+]i in a dose-dependent fashion; (2) PACAP-38 acts through phospholipase C to release inositol triphosphate (IP3)-sensitive Ca2+ stores with (3) a subsequent influx of extracellular Ca2+. CONCLUSIONS PACAP-38 activates calcium signaling through phospholipase C at concentrations that stimulate amylase release in AR42J cells.
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Affiliation(s)
- D C Barnhart
- Department of Surgery, University of Michigan, Ann Arbor, USA
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24
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Canonico PL, Copani A, D'Agata V, Musco S, Petralia S, Travali S, Stivala F, Cavallaro S. Activation of pituitary adenylate cyclase-activating polypeptide receptors prevents apoptotic cell death in cultured cerebellar granule cells. Ann N Y Acad Sci 1996; 805:470-2. [PMID: 8993425 DOI: 10.1111/j.1749-6632.1996.tb17505.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- P L Canonico
- Chair of Pharmacology, School of Dentistry, University of Pavìa, Italy
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25
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Gonzalez BJ, Basille M, Mei YA, Vaudry D, Fournier A, Cazin L, Vaudry H. Ontogeny of PACAP and PACAP receptors in the rat brain: role of PACAP in the cerebellum during development. Ann N Y Acad Sci 1996; 805:302-13; discussion 313-4. [PMID: 8993412 DOI: 10.1111/j.1749-6632.1996.tb17492.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- B J Gonzalez
- European Institute for Peptide Research (IFRMP No. 23), Laboratory of Cellular and Molecular Neuroendocrinology, INSERM U413, UA CNRS, University of Rouen, Mont-Saint-Aignan, France
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26
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Schäfer H, Trauzold A, Fölsch UR, Schmidt WE. Identification of novel growth-related genes linked to the mitogenic effect of PACAP on the rat pancreatic acinar cell line, AR4-2J. Ann N Y Acad Sci 1996; 805:760-7. [PMID: 8993474 DOI: 10.1111/j.1749-6632.1996.tb17554.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The mRNA differential display technique was employed in order to identify novel growth-related genes linked to the mitogenic effect of PACAP on AR4-2J cells. Hereby, three differentially expressed and PACAP-inducible genes were found, one of these being homologous to a recently discovered putative growth-related early response gene in mice. In AR4-2J cells, mRNA levels of this novel rat gene are increased by PACAP in a rapid and transient fashion. This effect was enhanced by cycloheximide, whereas actinomycin D prevented the stimulatory effect of PACAP.
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Affiliation(s)
- H Schäfer
- 1st Department of Medicine, Christian-Albrechts-University of Kiel, Germany
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27
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Schäfer H, Zheng J, Gundlach F, Günther R, Siegel EG, Fölsch UR, Schmidt WE. Pituitary adenylate-cyclase-activating polypeptide stimulates proto-oncogene expression and activates the AP-1 (c-Fos/c-Jun) transcription factor in AR4-2J pancreatic carcinoma cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 242:467-76. [PMID: 9022670 DOI: 10.1111/j.1432-1033.1996.467rr.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Pituitary adenylate-cyclase-activating polypeptide (PACAP) has been shown to possess mitogenic activity in various tumor cells. The present study was designed to investigate signal transduction mechanisms and expression of the proto-oncogenes c-fos and c-jun linked to the mitogenic effect of PACAP in the pancreatic carcinoma cell line AR4-2J. PACAP-(1-27)-peptide and PACAP-(1-38)-peptide, but not the structurally related vasoactive intestinal polypeptide (VIP), potently stimulated [3H]thymidine incorporation and cell number at doses of 0.1-10 nM. Both molecular forms of PACAP strongly increased formation of cAMP and inositol trisphosphate, elevated cytosolic Ca2+ levels and induced mitogen-activated protein (MAP) kinase activity. Quantitative reverse-transcription PCR revealed that PACAP-(1-27)-peptide and PACAP-(1-38)-peptide elevated c-fos mRNA levels 50-100-fold, whereas c-jun mRNA levels increased only moderately (2-3-fold). The effect of PACAP on c-fos and c-jun expression in AR4-2J cells was rapid (20 min), transient (1-2 h), dose-dependent IC50, 0.5 nM) and was abolished by the specific PACAP receptor antagonist PACAP-(6-38)-peptide or inhibitors of protein kinase C or tyrosine kinases. Compared with PACAP, epidermal growth factor and gastrin equipotently stimulated c-fos transcription whereas VIP, secretin, forskolin or phorbolester showed only marginal effects. Both PACAP (1-27)-peptide and PACAP-(1-38)-peptide strongly increased the DNA binding activity of the c-fos/ c-jun heterodimer transcription factor AP-1 at 10 nM and also stimulated AP-1 transcriptional activity up to 20-fold in AR4-2J cells. These findings indicate that the mitogenic effect of PACAP mediated via activation of the GTP-binding protein coupled PACAP/VIP-1 (PV1) receptor is linked to the MAP kinase cascade, increased expression of the proto-oncogenes c-fos and c-jun and activation of the heterodimeric transcription factor AP-1.
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Affiliation(s)
- H Schäfer
- 1st Department of Medicine, Christian-Albrechts University, Kiel, Germany
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28
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Morisset J, Douziech N, Rydzewska G, Buscail L, Rivard N. Cell signalling pathway involved in PACAP-induced AR4-2J cell proliferation. Cell Signal 1995; 7:195-205. [PMID: 7662508 DOI: 10.1016/0898-6568(94)00081-l] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The novel 38-amino acid neuropeptide PACAP (pituitary adenylate activating peptide) has recently been shown to induce the pancreatic acinar tumour AR4-2J cell growth. This growth promoting effect of PACAP was, however, independent of adenylate cyclase activation but suppressed by pertussis toxin and the somatostatin analog SMS 201-995. This study was undertaken to search for potential cell signalling pathways involved in the growth promoting effect of PACAP on AR4-2J cells. The AR4-2J cells were grown in Dulbecco's Modified Eagle's Medium containing 10% foetal calf serum. For studies on cell signalling pathways, all experiments were carried out on cells which have reached 50 to 75% confluency. At that point, they were transferred to serum free medium overnight with or without 1 microCi/ml myristic acid. The next morning, cells were harvested, washed and used for tyrosine kinase and phospholipase D (PLD) activities. For studies on growth, cells were grown for 2 days in the presence of 1 nM PACAP +/- the different inhibitors of tyrosine kinase and PLD. PACAP-38 and -27 caused a dose-dependent and parallel activation of tyrosine kinase and PLD an effect prevented by the antagonist PACAP 7-38. PACAP-38-stimulated tyrosine kinase and PLD activation are both dose-dependently inhibited by SMS 201-995. Finally, PACAP-stimulated tyrosine kinase and PLD activities are both inhibited by cell's preincubation with genistein and pertussis toxin. After 2 days, the PACAP-induced increase in AR4-2J cell growth was significantly inhibited by increasing concentrations of genistein and wortmannin, inhibitors of tyrosine kinase, PLD and phosphatidylinositol 3-kinase, respectively. PACAP can induce concomitant activation of tyrosine kinase and PLD; this finding and the observation that inhibition of these two enzymes inhibited PACAP-induced AR4-2J cell growth strongly suggests that they are intimately involved in the overall process of PACAP-induced AR4-2J cell proliferation.
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Affiliation(s)
- J Morisset
- Départment de Biologie, Faculté des Sciences, Université de Sherbrooke, Québec, Canada
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29
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Schwarzhoff R, Schwörer H, Fornefeld H, Morys-Wortmann C, Katsoulis S, Creutzfeldt W, Fölsch UR, Schmidt WE. Specific monoclonal antibodies neutralize the action of PACAP 1-27 or PACAP 1-38 on intestinal muscle strips in vitro. REGULATORY PEPTIDES 1995; 55:57-66. [PMID: 7724828 DOI: 10.1016/0167-0115(94)00092-c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The gut-brain neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP) is a novel highly conserved member of the secretin-glucagon-VIP peptide family comprising 38 or 27 amino acid residues. In this study, we investigate the actions of PACAP 1-27 or PACAP 1-38 on jejunal and caecal muscle strips from pig or guinea pig and demonstrate the neutralizing effect of two PACAP-specific monoclonal antibodies of the IgG1 subtype, RSP27II and RSP38. These antibodies were used to set up assay systems specific for PACAP 1-27 or PACAP 1-38. Monoclonal antibody RSP27II recognizes exclusively PACAP 1-27, whereas RSP38 binds only PACAP 1-38. PACAP 1-27 and PACAP 1-38 relax taenia caeci dose-dependently in the presence of guanethidine and scopolamine. Both peptides inhibit the spontaneous contractions of porcine jejunal muscle strips equipotently. Monoclonal antibodies RSP27II and RSP38 specifically neutralize the actions of either exogenously applied or endogenously released PACAP. Thus, they represent processing-specific tools to examine the physiological role of both molecular forms of PACAP in the gastrointestinal tract.
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Affiliation(s)
- R Schwarzhoff
- I. Department of Medicine, Christian-Albrechts-University of Kiel, Germany
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30
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Basille M, Gonzalez BJ, Fournier A, Vaudry H. Ontogeny of pituitary adenylate cyclase-activating polypeptide (PACAP) receptors in the rat cerebellum: a quantitative autoradiographic study. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1994; 82:81-9. [PMID: 7842522 DOI: 10.1016/0165-3806(94)90150-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide and PACAP receptors are both present in the rat cerebellar cortex, suggesting that PACAP may play an important role in the cerebellum. In the present study, the variation of the concentration of PACAP binding sites in the rat cerebellum was investigated during postnatal development by means of quantitative autoradiography, using [125I]PACAP27 as a radioligand. In the external granule cell layer and the medulla, the density of PACAP binding sites was high at birth, markedly decreased from postnatal day 8 (P8) to P25 and finally vanished at the end of the third postnatal week. In the internal granule cell layer and molecular layer, PACAP binding sites were first detected at P8. In the internal granule cell layer, the density of binding sites slightly decreased during development but remained elevated in adults. Conversely, in the molecular layer, PACAP binding sites rapidly decreased during the second and third postnatal weeks and virtually disappeared after P25. In all four layers of the cerebellar cortex, the autoradiographic labeling was displaced by PACAP27 (IC50 close to 10(-8) M), but was not affected by VIP. No significant changes in IC50 and Hill coefficient were noticed in the various layers throughout development. The present study shows that all four layers of the cerebellar cortex express PACAP binding sites during development. The evolution of the receptor concentration exhibited differential profiles in the various layers but the specificity characteristics of the recognition sites were identical in all four structures.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M Basille
- Institut Fédératif de Recherches Multidisciplinaires sur les Peptides, Unité INSERM U 413, Unité affilieé au CNRS, Faculté des Sciences, Université de Rouen, Mont-Saint-Aignan, France
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Affiliation(s)
- S R Rawlings
- Fondation pour Recherches Médicales, University of Geneva, Switzerland
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Fabre C, el Battari A, Bellan C, Pasqualini E, Marvaldi J, Lombardo D, Luis J. Characterization of the oligosaccharide moiety of VIP receptor from the human pancreatic cell line BxPC-3. Peptides 1993; 14:1331-8. [PMID: 8134315 DOI: 10.1016/0196-9781(93)90194-l] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The human pancreatic cell line BxPC-3 displays two classes of binding sites with high and low affinity for VIP. The order of potency of VIP-related peptides in inhibiting either [125I]VIP or [125I]N-AcPACAP27 binding and in stimulating cAMP production was typical of the human VIP receptor. By combining affinity labeling with glycosidase treatments, we have characterized the VIP receptor as a M(r) = 68,200 glycoprotein, consisting of a M(r) = 39,300 polypeptide core with at least three N-linked oligosaccharide chains. In addition, our results revealed the presence of a low amount of sialic acid residues in the carbohydrate moiety of receptor.
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Affiliation(s)
- C Fabre
- Institut de Chimie Biologique, CNRS URA 202, Université de Provence, Marseille, France
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Christophe J. Type I receptors for PACAP (a neuropeptide even more important than VIP?). BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1154:183-99. [PMID: 8218337 DOI: 10.1016/0304-4157(93)90011-c] [Citation(s) in RCA: 147] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Among vertebrates, there is an extreme conservation in amino acid sequence for the neuropeptide PACAP-38 and its C-terminal shortened derivative PACAP-27. The PACAP gene is assigned to chromosome 18 in man and its organization has been characterized. PACAP-38 and its minor derivative PACAP-27 are widely distributed in the central nervous system. PACAP-38 is particularly abundant in hypothalamus. The mapping of the afferentation and efferentation of PACAP systems are progressively delineated, including a search for the colocalization with other neurotransmitters. In several peripheral organs positive neuronal perikarya and fibers are also seen. PACAP acts through two types of receptors: (1) the highly selective type I that displays a 500 to 2000 selectivity for PACAP-38 and PACAP-27 as compared to VIP; (2) type II is the so-called VIP receptor showing similar high affinity for PACAP-38, PACAP-27 and VIP. It is less selective, therefore, than previously thought. This is why this second receptor, qualifying as an unspecific VIP-PACAP receptor, is hardly considered here. Type I receptors can stimulate two enzymes: the adenylate cyclase and phospholipase C (whose activation leads to the inositol phosphate-cytosolic Ca2+ cascade). This dual coupling may have several distal consequences including on gene expression, cell growth and differentiation. Although a relatively comprehensive spectrum of pharmacological activities has already been established we still need to limit the physiological roles of PACAP as neurotransmitter and/or neuromodulator. Concerning the hypothalamo-pituitary axis, PACAP reduces food intake in mice and raises plasma arginine vasopressin in rat, probably through PACAP-ir neurons in paraventricular and supraoptic nuclei projecting to the neurohypophysis. PACAP originating in the hypothalamus may also be transported to the anterior pituitary through portal vessels. Data on the antehypophysis suggest a role on i.a. reproduction and growth. PACAP stimulates adenylate cyclase and increases [Ca2+] in gonadotropes, somatotropes, and folliculo-stellate cells. It elevates the secretion of alpha-MSH from melanotropes, and that of interleukin-6 from pituitary folliculo-stellate cells. PACAP potentiates the effects of LHRH on LH and FSH secretion. More clearly perhaps, PACAP increases the synthesis of LH, GH, PRL and ACTH after 1-2 days. In human pathology, PACAP-27 and PACAP-38 stimulate adenylate cyclase activity in membranes from 'null'-, gonadotropin-, GH-, and ACTH-producing pituitary adenomas but are inactive in prolactinomas.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- J Christophe
- Department of Biochemistry and Nutrition, Medical School, Université Libre de Bruxelles, Belgium
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