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Shin SY, Shen TC, Wank SA, Summers RM. Fully-automated detection of small bowel carcinoid tumors in CT scans using deep learning. Med Phys 2023; 50:7865-7878. [PMID: 36988164 PMCID: PMC10539477 DOI: 10.1002/mp.16391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 02/20/2023] [Accepted: 03/15/2023] [Indexed: 03/30/2023] Open
Abstract
BACKGROUND Small bowel carcinoid tumor is a rare neoplasm and increasing in incidence. Patients with small bowel carcinoid tumors often experience long delays in diagnosis due to the vague symptoms, slow growth of tumors, and lack of clinician awareness. Computed tomography (CT) is the most common imaging study for diagnosis of small bowel carcinoid tumor. It is often used with positron emission tomography (PET) to capture anatomical and functional aspects of carcinoid tumors and thus to increase the sensitivity. PURPOSE We compared three different kinds of methods for the automatic detection of small bowel carcinoid tumors on CT scans, which is the first to the best of our knowledge. METHODS Thirty-three preoperative CT scans of 33 unique patients with surgically-proven carcinoid tumors within the small bowel were collected. Ground-truth segmentation of tumors was drawn on CT scans by referring to available 18 F-DOPA PET scans and the corresponding radiology report. These scans were split into the trainval set (n = 24) and the test positive set (n= 9). Additionally, 22 CT scans of 22 unique patients who had no evidence of the tumor were collected to comprise the test negative set. We compared three different kinds of detection methods, which are detection network, patch-based classification, and segmentation-based methods. We also investigated the usefulness of small bowel segmentation for reduction of false positives (FPs) for each method. Free-response receiver operating characteristic (FROC) curves and receiver operating characteristic (ROC) curves were used for lesion- and patient-level evaluations, respectively. Statistical analyses comparing the FROC and ROC curves were also performed. RESULTS The detection network method performed the best among the compared methods. For lesion-level detection, the detection network method, without the small bowel segmentation-based filtering, achieved sensitivity values of (60.8%, 81.1%, 82.4%, 86.5%) at per-scan FP rates of (1, 2, 4 ,8), respectively. The use of the small bowel segmentation did not improve the performance (p = 0.742 $p=0.742$ ). For patient-level detection, again the detection network method, but with the small bowel segmentation-based filtering, achieved the highest AUC of 0.86 with a sensitivity of 78% and specificity of 82% at the Youden point. CONCLUSIONS The carcinoid tumors in this patient population were very small and potentially difficult to diagnose. The presented method showed reasonable sensitivity at small numbers of FPs for lesion-level detection. It also achieved a promising AUC for patient-level detection. The method may have clinical application in patients with this rare and difficult to detect disease.
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Affiliation(s)
- Seung Yeon Shin
- Imaging Biomarkers and Computer-Aided Diagnosis Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Thomas C Shen
- Imaging Biomarkers and Computer-Aided Diagnosis Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Stephen A Wank
- Digestive Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Ronald M Summers
- Imaging Biomarkers and Computer-Aided Diagnosis Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
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Li Y, Lu Z, Kirkwood CL, Kirkwood KL, Wank SA, Li AJ, Lopes-Virella MF, Huang Y. GPR40 deficiency worsens metabolic syndrome-associated periodontitis in mice. J Periodontal Res 2023; 58:575-587. [PMID: 36807310 PMCID: PMC10182248 DOI: 10.1111/jre.13107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 01/13/2023] [Accepted: 01/30/2023] [Indexed: 02/20/2023]
Abstract
BACKGROUND AND OBJECTIVE G protein-coupled receptor 40 (GPR40) is a receptor for medium- and long-chain free fatty acids (FFAs). GPR40 activation improves type 2 diabetes mellitus (T2DM), metabolic syndrome (MetS), and the complications of T2DM and MetS. Periodontitis, a common oral inflammatory disease initiated by periodontal pathogens, is another complication of T2DM and MetS. Since FFAs play a key role in the pathogenesis of MetS which exacerbates periodontal inflammation and GPR40 is a FFA receptor with anti-inflammatory properties, it is important to define the role of GPR40 in MetS-associated periodontitis. MATERIALS AND METHODS We induced MetS and periodontitis by high-fat diet and periodontal injection of lipopolysaccharide (LPS), respectively, in wild-type and GPR40-deficient mice and determined alveolar bone loss and periodontal inflammation using micro-computed tomography, histology, and osteoclast staining. We also performed in vitro study to determine the role of GPR40 in the expression of proinflammatory genes. RESULTS The primary outcome of the study is that GPR40 deficiency increased alveolar bone loss and enhanced osteoclastogenesis in control mice and the mice with both MetS and periodontitis. GPR40 deficiency also augmented periodontal inflammation in control mice and the mice with both MetS and periodontitis. Furthermore, GPR40 deficiency led to increased plasma lipids and insulin resistance in control mice but had no effect on the metabolic parameters in mice with MetS alone. For mice with both MetS and periodontitis, GPR40 deficiency increased insulin resistance. Finally, in vitro studies with macrophages showed that deficiency or inhibition of GPR40 upregulated proinflammatory genes while activation of GPR40 downregulated proinflammatory gene expression stimulated synergistically by LPS and palmitic acid. CONCLUSION GPR40 deficiency worsens alveolar bone loss and periodontal inflammation in mice with both periodontitis and MetS, suggesting that GPR40 plays a favorable role in MetS-associated periodontitis. Furthermore, GPR40 deficiency or inhibition in macrophages further upregulated proinflammatory and pro-osteoclastogenic genes induced by LPS and palmitic acid, suggesting that GPR40 has anti-inflammatory and anti-osteoclastogenic properties.
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Affiliation(s)
- Yanchun Li
- Division of Endocrinology, Diabetes and Metabolic Diseases, Department of Medicine, College of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Zhongyang Lu
- Division of Endocrinology, Diabetes and Metabolic Diseases, Department of Medicine, College of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Cameron L. Kirkwood
- Departments of Oral Biology, School of Dental Medicine, University at Buffalo
| | - Keith L. Kirkwood
- Departments of Oral Biology, School of Dental Medicine, University at Buffalo
- Department of Head & Neck/Plastic & Reconstructive Surgery, Roswell Park Comprehensive Cancer Center, Buffalo, New York
| | - Stephen A. Wank
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland
| | - Ai-Jun Li
- Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Maria F. Lopes-Virella
- Division of Endocrinology, Diabetes and Metabolic Diseases, Department of Medicine, College of Medicine, Medical University of South Carolina, Charleston, South Carolina
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina
| | - Yan Huang
- Division of Endocrinology, Diabetes and Metabolic Diseases, Department of Medicine, College of Medicine, Medical University of South Carolina, Charleston, South Carolina
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina
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Reilly L, Semenza ER, Koshkaryan G, Mishra S, Chatterjee S, Abramson E, Mishra P, Sei Y, Wank SA, Donowitz M, Snyder SH, Guha P. Loss of PI3k activity of inositol polyphosphate multikinase impairs PDK1-mediated AKT activation, cell migration, and intestinal homeostasis. iScience 2023; 26:106623. [PMID: 37216099 PMCID: PMC10197106 DOI: 10.1016/j.isci.2023.106623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 02/22/2023] [Accepted: 04/03/2023] [Indexed: 05/24/2023] Open
Abstract
Protein kinase B (AKT) is essential for cell survival, proliferation, and migration and has been associated with several diseases. Here, we demonstrate that inositol polyphosphate multikinase (IPMK's) lipid kinase property drives AKT activation via increasing membrane localization and activation of PDK1 (3-Phosphoinositide-dependent kinase 1), largely independent of class I PI3k (cPI3K). Deletion of IPMK impairs cell migration, which is partially associated with the abolition of PDK1-mediated ROCK1 disinhibition and subsequent myosin light chain (MLC) phosphorylation. IPMK is highly expressed in intestinal epithelial cells (IEC). Deleting IPMK in IEC reduced AKT phosphorylation and diminished the number of Paneth cells. Ablation of IPMK impaired IEC regeneration both basally and after chemotherapy-induced damage, suggesting a broad role for IPMK in activating AKT and intestinal tissue regeneration. In conclusion, the PI3k activity of IPMK is necessary for PDK1-mediated AKT activation and intestinal homeostasis.
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Affiliation(s)
- Luke Reilly
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Evan R. Semenza
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - George Koshkaryan
- Nevada Institute of Personalized Medicine (NIPM), University of Nevada, Las Vegas, NV 89154, USA
| | - Subrata Mishra
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Reference Standard Laboratory, United States Pharmacopeial Convention, Rockville, MD 20852, USA
| | - Sujan Chatterjee
- Nevada Institute of Personalized Medicine (NIPM), University of Nevada, Las Vegas, NV 89154, USA
| | - Efrat Abramson
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Pamela Mishra
- Marie-Josée and Henry R. Kravis Center for Molecular Oncology, Memorial Sloan Kettering Cancer Center, New York City, NY, USA
| | - Yoshitasu Sei
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Stephen A. Wank
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Mark Donowitz
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Baltimore, MD 21205, USA
| | - Solomon H. Snyder
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Prasun Guha
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Nevada Institute of Personalized Medicine (NIPM), University of Nevada, Las Vegas, NV 89154, USA
- School of Life Sciences, University of Nevada, Las Vegas, NV 89154, USA
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Sei Y, Feng J, Zhao X, Dagur P, McCoy JP, Merchant JL, Wank SA. Tissue- and cell-specific properties of enterochromaffin cells affect the fate of tumorigenesis toward nonendocrine adenocarcinoma of the small intestine. Am J Physiol Gastrointest Liver Physiol 2023; 324:G177-G189. [PMID: 36537709 PMCID: PMC9925174 DOI: 10.1152/ajpgi.00205.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 11/16/2022] [Accepted: 12/14/2022] [Indexed: 01/31/2023]
Abstract
Small intestinal neuroendocrine tumors (SI-NETs) are serotonin-secreting well-differentiated neuroendocrine tumors of putative enterochromaffin (EC) cell origin. However, EC cell-derived tumorigenesis remains poorly understood. Here, we examined whether the gain of Myc and the loss of RB1 and Trp53 function in EC cells result in SI-NET using tryptophan hydroxylase 1 (TPH1) Cre-ERT2-driven RB1fl Trp53fl MycLSL (RPM) mice. TPH1-Cre-induced gain of Myc and loss of RB1 and Trp53 function resulted in endocrine or neuronal tumors in pancreas, lung, enteric neurons, and brain. Lineage tracing indicated that the cellular origin for these tumors was TPH1-expressing neuroendocrine, neuronal, or their precursor cells in these organs. However, despite that TPH1 is most highly expressed in EC cells of the small intestine, we observed no incidence of EC cell tumors. Instead, the tumor of epithelial cell origin in the intestine was exclusively nonendocrine adenocarcinoma, suggesting dedifferentiation of EC cells into intestinal stem cells (ISCs) as a cellular mechanism. Furthermore, ex vivo organoid studies indicated that loss of functions of Rb1 and Trp53 accelerated dedifferentiation of EC cells that were susceptible to apoptosis with expression of activated MycT58A, suggesting that the rare dedifferentiating cells escaping cell death went on to develop adenocarcinomas. Lineage tracing demonstrated that EC cells in the small intestine were short-lived compared with neuroendocrine or neuronal cells in other organs. In contrast, EC cell-derived ISCs were long-lasting and actively cycling and thus susceptible to transformation. These results suggest that tissue- and cell-specific properties of EC cells such as rapid cell turnover and homeostatic dedifferentiation, affect the fate and rate of tumorigenesis induced by genetic alterations and provide important insights into EC cell-derived tumorigenesis.NEW & NOTEWORTHY Small intestinal neuroendocrine tumors are of putative enterochromaffin (EC) cell origin and are the most common malignancy in the small intestine, followed by adenocarcinoma. However, the tumorigenesis of these tumor types remains poorly understood. The present lineage tracing studies showed that tissue- and cell-specific properties of EC cells such as rapid cell turnover and homeostatic dedifferentiation affect the fate and rate of tumorigenesis induced by genetic alterations toward a rare occurrence of adenocarcinoma.
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Affiliation(s)
- Yoshitatsu Sei
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Jianying Feng
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Xilin Zhao
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Pradeep Dagur
- Flow Cytometry Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - J Philip McCoy
- Flow Cytometry Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Juanita L Merchant
- Department of Internal Medicine-Gastroenterology, University of Arizona, Tuscan, Arizona
| | - Stephen A Wank
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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Shin SY, Shen TC, Wank SA, Summers RM. Improving Small Lesion Segmentation in CT Scans using Intensity Distribution Supervision: Application to Small Bowel Carcinoid Tumor. Proc SPIE Int Soc Opt Eng 2023; 12465:124651S. [PMID: 37124052 PMCID: PMC10139734 DOI: 10.1117/12.2651979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Finding small lesions is very challenging due to lack of noticeable features, severe class imbalance, as well as the size itself. One approach to improve small lesion segmentation is to reduce the region of interest and inspect it at a higher sensitivity rather than performing it for the entire region. It is usually implemented as sequential or joint segmentation of organ and lesion, which requires additional supervision on organ segmentation. Instead, we propose to utilize an intensity distribution of a target lesion at no additional labeling cost to effectively separate regions where the lesions are possibly located from the background. It is incorporated into network training as an auxiliary task. We applied the proposed method to segmentation of small bowel carcinoid tumors in CT scans. We observed improvements for all metrics (33.5% → 38.2%, 41.3% → 47.8%, 30.0% → 35.9% for the global, per case, and per tumor Dice scores, respectively.) compared to the baseline method, which proves the validity of our idea. Our method can be one option for explicitly incorporating intensity distribution information of a target in network training.
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Affiliation(s)
- Seung Yeon Shin
- Imaging Biomarkers and Computer-Aided Diagnosis Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Thomas C. Shen
- Imaging Biomarkers and Computer-Aided Diagnosis Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Stephen A. Wank
- Digestive Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ronald M. Summers
- Imaging Biomarkers and Computer-Aided Diagnosis Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA
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Sei Y, Forbes J, Da B, Chitsaz E, Feng J, Zhao X, Hughes MS, Wank SA. Diagnostic value of whole-mount crypt analysis of ileal biopsy specimens for the patients with familial small intestinal neuroendocrine tumors. Ther Adv Med Oncol 2023; 15:17588359231156871. [PMID: 36936198 PMCID: PMC10014972 DOI: 10.1177/17588359231156871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 01/27/2023] [Indexed: 03/14/2023] Open
Abstract
Background and Aims Early-stage small intestinal neuroendocrine tumors (SI-NETs) are generally asymptomatic and difficult to diagnose. As a result, patients often present with late-stage incurable disease. SI-NETs originate from enterochromaffin (EC) cells, which develop enteroendocrine cell (EEC) clusters consisting of a subset of EC cells at the crypt bottom at an early stage of tumor progression. In a familial form of SI-NET, EEC clusters arise in a multifocal and polyclonal fashion. We sought to determine whether early detection and analysis of cryptal EEC clusters could provide insight into the development of SI-NETs and allow successful pre-symptomatic screening for at risk family members of patients with SI-NETs. Methods Isolated crypts from endoscopic ileal biopsies or surgically removed specimens from 43 patients with familial SI-NET and 20 controls were formalin-fixed, immunostained for chromogranin A, and examined by confocal three-dimensional analysis for the presence of EEC cluster formations. Results Examination of multiple areas of macroscopic tumor-free mucosa in surgically resected specimens from patients with familial SI-NET revealed widely distributed, independent, multifocal EEC micro-tumor formations of varying sizes. Consistent with this finding, randomly sampled ileal biopsy specimens identified aberrant crypt containing endocrine cell clusters (ACECs) in patients. ACECs were found exclusively in patients (23/43, 53%) and not in controls (0/20). Furthermore, analysis of positions and numbers of EECs in crypts and ACECs indicated significant increases in EECs at the crypt bottom, predominantly at positions 0 and 1' (p < 0.0001 compared to controls), suggesting the progression of EEC accumulation below +4 position as the early process of ACEC formation. These findings also suggested that ACECs were precursors in the development of micro-tumors and subsequent macro-tumors. Conclusion This study indicates that SI-NETs develop from deep crypt EC cells to become ACECs, micro-tumors, and ultimately gross tumors. This process occurs widely throughout the distal small intestine in patients with familial SI-NETs consistent with but not exclusively explained by germline disease. Finally, analysis of crypts from ileal biopsies could contribute in part to earlier diagnostic screening processes avoiding late-stage presentation of incurable disease.
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Affiliation(s)
- Yoshitatsu Sei
- Digestive Diseases Branch, National Institute
of Diabetes and Digestive and Kidney Diseases, National Institutes of
Health, Bethesda, MD, USA
| | - Joanne Forbes
- Digestive Diseases Branch, National Institute
of Diabetes and Digestive and Kidney Diseases, National Institutes of
Health, Bethesda, MD, USA
| | - Ben Da
- Digestive Diseases Branch, National Institute
of Diabetes and Digestive and Kidney Diseases, National Institutes of
Health, Bethesda, MD, USA
| | - Ehsan Chitsaz
- Digestive Diseases Branch, National Institute
of Diabetes and Digestive and Kidney Diseases, National Institutes of
Health, Bethesda, MD, USA
| | - Jianying Feng
- Digestive Diseases Branch, National Institute
of Diabetes and Digestive and Kidney Diseases, National Institutes of
Health, Bethesda, MD, USA
| | - Xilin Zhao
- Digestive Diseases Branch, National Institute
of Diabetes and Digestive and Kidney Diseases, National Institutes of
Health, Bethesda, MD, USA
| | - Marybeth S. Hughes
- Surgery Branch, National Cancer Institute,
National Institutes of Health, Bethesda, MD, USA
- Current Address: Surgical Oncology, East
Virginia Medical School, Norfolk, VA
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Lu Z, Li Y, Li AJ, Syn WK, Wank SA, Lopes-Virella MF, Huang Y. Loss of GPR40 in LDL receptor-deficient mice exacerbates high-fat diet-induced hyperlipidemia and nonalcoholic steatohepatitis. PLoS One 2022; 17:e0277251. [PMID: 36331958 PMCID: PMC9635748 DOI: 10.1371/journal.pone.0277251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022] Open
Abstract
GPR40, a G protein-coupled receptor for free fatty acids (FFAs), is considered as a therapeutic target for type 2 diabetes mellitus (T2DM) since GPR40 activation in pancreatic beta cells enhances glucose-stimulated insulin secretion. Nonalcoholic fatty liver disease (NAFLD) is a common complication of T2DM or metabolic syndrome (MetS). However, the role of GPR40 in NAFLD associated with T2DM or MetS has not been well established. Given that it is known that cholesterol and FFAs are critically involved in the pathogenesis of nonalcoholic steatohepatitis (NASH) and LDL receptor (LDLR)-deficient mice are a good animal model for human hyperlipidemia including high cholesterol and FFAs, we generated GPR40 and LDLR double knockout (KO) mice in this study to determine the effect of GPR40 KO on hyperlipidemia-promoted NASH. We showed that GPR40 KO increased plasma levels of cholesterol and FFAs in high-fat diet (HFD)-fed LDLR-deficient mice. We also showed that GPR40 KO exacerbated HFD-induced hepatic steatosis, inflammation and fibrosis. Further study demonstrated that GPR40 KO led to upregulation of hepatic CD36 and genes involved in lipogenesis, fatty acid oxidation, fibrosis and inflammation. Finally, our in vitro mechanistic studies showed that while CD36 was involved in upregulation of proinflammatory molecules in macrophages by palmitic acid (PA) and lipopolysaccharide (LPS), GPR40 activation in macrophages exerts anti-inflammatory effects. Taken together, this study demonstrated for the first time that loss of GPR40 in LDLR-deficient mice exacerbated HFD-induced hyperlipidemia, hepatic steatosis, inflammation and fibrosis potentially through a CD36-dependent mechanism, suggesting that GPR40 may play a beneficial role in hyperlipidemia-associated NASH in LDLR-deficient mice.
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Affiliation(s)
- Zhongyang Lu
- Division of Endocrinology, Diabetes and Metabolic Diseases, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Yanchun Li
- Division of Endocrinology, Diabetes and Metabolic Diseases, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Ai-Jun Li
- Programs in Neuroscience, Washington State University, Pullman, Washington, United States of America
| | - Wing-Kin Syn
- Division of Gastroenterology and Hepatology, Medical University of South Carolina, Charleston, South Carolina, United States of America
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina, United States of America
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country, Euskal Herriko Unibertsitatea/Universidad del País Vasco, Leioa, Spain
| | - Stephen A. Wank
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland, United States of America
| | - Maria F. Lopes-Virella
- Division of Endocrinology, Diabetes and Metabolic Diseases, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina, United States of America
| | - Yan Huang
- Division of Endocrinology, Diabetes and Metabolic Diseases, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina, United States of America
- * E-mail:
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Lu Z, Li Y, Syn WK, Li AJ, Ritter WS, Wank SA, Lopes-Virella MF, Huang Y. GPR40 deficiency is associated with hepatic FAT/CD36 upregulation, steatosis, inflammation, and cell injury in C57BL/6 mice. Am J Physiol Endocrinol Metab 2021; 320:E30-E42. [PMID: 33103454 PMCID: PMC8436599 DOI: 10.1152/ajpendo.00257.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/21/2020] [Accepted: 10/15/2020] [Indexed: 02/07/2023]
Abstract
G-protein-coupled receptor 40 (GPR40) is highly expressed in pancreatic islets, and its activation increases glucose-stimulated insulin secretion from pancreas. Therefore, GPR40 is considered as a target for type 2 diabetes mellitus (T2DM). Since nonalcoholic fatty liver disease (NAFLD) is associated with T2DM and GPR40 is also expressed by hepatocytes and macrophages, it is important to understand the role of GPR40 in NAFLD. However, the role of GPR40 in NAFLD in animal models has not been well defined. In this study, we fed wild-type or GPR40 knockout C57BL/6 mice a high-fat diet (HFD) for 20 wk and then assessed the effect of GPR40 deficiency on HFD-induced NAFLD. Assays on metabolic parameters showed that an HFD increased body weight, glucose, insulin, insulin resistance, cholesterol, and alanine aminotransferase (ALT), and GPR40 deficiency did not mitigate the HFD-induced metabolic abnormalities. In contrast, we found that GPR40 deficiency was associated with increased body weight, insulin, insulin resistance, cholesterol, and ALT in control mice fed a low-fat diet (LFD). Surprisingly, histology and Oil Red O staining showed that GPR40 deficiency in LFD-fed mice was associated with steatosis. Immunohistochemical analysis showed that GPR40 deficiency also increased F4/80, a macrophage biomarker, in LFD-fed mice. Furthermore, results showed that GPR40 deficiency led to a robust upregulation of hepatic fatty acid translocase (FAT)/CD36 expression. Finally, our in vitro studies showed that GPR40 knockdown by siRNA or a GPR40 antagonist increased palmitic acid-induced FAT/CD36 mRNA in hepatocytes. Taken together, this study indicates that GPR40 plays an important role in homeostasis of hepatic metabolism and inflammation and inhibits nonalcoholic steatohepatitis by possible modulation of FAT/CD36 expression.
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Affiliation(s)
- Zhongyang Lu
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina
| | - Yanchun Li
- Division of Endocrinology, Diabetes, and Medical Genetics, Medical University of South Carolina, Charleston, South Carolina
| | - Wing-Kin Syn
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina
- Division of Gastroenterology and Hepatology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country, Euskal Herriko Unibertsitatea/Universidad del País Vasco, Leioa, Spain
| | - Ai-Jun Li
- Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - W Sue Ritter
- Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Stephen A Wank
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland
| | - Maria F Lopes-Virella
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina
- Division of Endocrinology, Diabetes, and Medical Genetics, Medical University of South Carolina, Charleston, South Carolina
| | - Yan Huang
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina
- Division of Endocrinology, Diabetes, and Medical Genetics, Medical University of South Carolina, Charleston, South Carolina
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Sei Y, Feng J, Zhao X, Wank SA. Role of an active reserve stem cell subset of enteroendocrine cells in intestinal stem cell dynamics and the genesis of small intestinal neuroendocrine tumors. Am J Physiol Gastrointest Liver Physiol 2020; 319:G494-G501. [PMID: 32845170 PMCID: PMC7654644 DOI: 10.1152/ajpgi.00278.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Small intestinal neuroendocrine tumors (SI-NET) are serotonin-secreting well-differentiated neuroendocrine tumors of putative enterochromaffin (EC) cell origin. Recent studies recognize a subset of EC cells that is label-retaining at the +4 position in the crypt and functions as a reserve intestinal stem cell. Importantly, this +4 reserve EC cell subset not only contributes to regeneration of the intestinal epithelium during injury and inflammation but also to basal crypt homeostasis at a constant rate. The latter function suggests that the +4 EC cell subset serves as an active reserve stem cell via a constant rate of dedifferentiation. Characterization of early tumor formation of SI-NET, observed as crypt-based EC cell clusters in many cases of familial SI-NETs, suggests that the +4 active reserve EC cell subset is the cell of origin. This newly discovered active reserve stem cell property of EC cells can account for unique biological mechanisms and processes associated with the genesis and development of SI-NETs. The recognition of this property of the +4 active reserve EC cell subset may provide novel opportunities to explore NETs in the gastrointestinal tract and other organs.
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Affiliation(s)
- Yoshitatsu Sei
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Jianying Feng
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Xilin Zhao
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Stephen A. Wank
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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Affiliation(s)
| | - Jessica Hunt
- MedicineThe George Washington UniversityWashingtonDC
| | - Xiaoyan Wang
- MedicineThe George Washington UniversityWashingtonDC
| | | | | | | | - Dominic Raj
- MedicineThe George Washington UniversityWashingtonDC
| | - Pedro A Jose
- MedicineThe George Washington UniversityWashingtonDC
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Abstract
The normal intestinal epithelium is continuously regenerated at a rapid rate from actively cycling Lgr5-expressing intestinal stem cells (ISCs) that reside at the crypt base. Recent mathematical modeling based on several lineage-tracing studies in mice shows that the symmetric cell division-dominant neutral drift model fits well with the observed in vivo growth of ISC clones and suggests that symmetric divisions are central to ISC homeostasis. However, other studies suggest a critical role for asymmetric cell division in the maintenance of ISC homeostasis in vivo. Here, we show that the stochastic branching and Moran process models with both a symmetric and asymmetric division mode not only simulate the stochastic growth of the ISC clone in silico but also closely fit the in vivo stem cell dynamics observed in lineage-tracing studies. In addition, the proposed model with highest probability for asymmetric division is more consistent with in vivo observations reported here and by others. Our in vivo studies of mitotic spindle orientations and lineage-traced progeny pairs indicate that asymmetric cell division is a dominant mode used by ISCs under normal homeostasis. Therefore, we propose the asymmetric cell division-dominant neutral drift model for normal ISC homeostasis. NEW & NOTEWORTHY The prevailing mathematical model suggests that intestinal stem cells (ISCs) divide symmetrically. The present study provides evidence that asymmetric cell division is the major contributor to ISC maintenance and thus proposes an asymmetric cell division-dominant neutral drift model. Consistent with this model, in vivo studies of mitotic spindle orientation and lineage-traced progeny pairs indicate that asymmetric cell division is the dominant mode used by ISCs under normal homeostasis.
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Affiliation(s)
- Yoshitatsu Sei
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Jianying Feng
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Carson C. Chow
- 2Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Stephen A. Wank
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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Sei Y, Feng J, Samsel L, White A, Zhao X, Yun S, Citrin D, McCoy JP, Sundaresan S, Hayes MM, Merchant JL, Leiter A, Wank SA. Mature enteroendocrine cells contribute to basal and pathological stem cell dynamics in the small intestine. Am J Physiol Gastrointest Liver Physiol 2018; 315:G495-G510. [PMID: 29848020 PMCID: PMC6230697 DOI: 10.1152/ajpgi.00036.2018] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Lgr5-expressing intestinal stem cells (ISCs) maintain continuous and rapid generation of the intestinal epithelium. Here, we present evidence that dedifferentiation of committed enteroendocrine cells (EECs) contributes to maintenance of the epithelium under both basal conditions and in response to injury. Lineage-tracing studies identified a subset of EECs that reside at +4 position for more than 2 wk, most of which were BrdU-label-retaining cells. Under basal conditions, cells derived from these EECs grow from the bottom of the crypt to generate intestinal epithelium according to neutral drift kinetics that is consistent with dedifferentiation of mature EECs to ISCs. The lineage tracing of EECs demonstrated reserve stem cell properties in response to radiation-induced injury with the generation of reparative EEC-derived epithelial patches. Finally, the enterochromaffin (EC) cell was the predominant EEC type participating in these stem cell dynamics. These results provide novel insights into the +4 reserve ISC hypothesis, stem cell dynamics of the intestinal epithelium, and in the development of EC-derived small intestinal tumors. NEW & NOTEWORTHY The current manuscript demonstrating that a subset of mature enteroendocrine cells (EECs), predominantly enterochromaffin cells, dedifferentiates to fully functional intestinal stem cells (ISCs) is novel, timely, and important. These cells dedifferentiate to ISCs not only in response to injury but also under basal homeostatic conditions. These novel findings provide a mechanism in which a specified cell can dedifferentiate and contribute to normal tissue plasticity as well as the development of EEC-derived intestinal tumors under pathologic conditions.
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Affiliation(s)
- Yoshitatsu Sei
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Jianying Feng
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Leigh Samsel
- 2Flow Cytometry Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Ayla White
- 3Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Xilin Zhao
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Sajung Yun
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Deborah Citrin
- 3Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - J. Philip McCoy
- 2Flow Cytometry Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Sinju Sundaresan
- 4Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan
| | - Michael M. Hayes
- 4Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan
| | - Juanita L. Merchant
- 5Department of Molecular and Integrative Physiology, University of Michigan Medical Center, Ann Arbor, Michigan
| | - Andrew Leiter
- 6Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Stephen A. Wank
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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Sei Y, Feng J, Zhao X, Forbes J, Tang D, Nagashima K, Hanson J, Quezado MM, Hughes MS, Wank SA. Polyclonal Crypt Genesis and Development of Familial Small Intestinal Neuroendocrine Tumors. Gastroenterology 2016; 151:140-51. [PMID: 27003604 PMCID: PMC5578471 DOI: 10.1053/j.gastro.2016.03.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 03/10/2016] [Accepted: 03/11/2016] [Indexed: 01/17/2023]
Abstract
BACKGROUND & AIMS Small intestinal neuroendocrine tumors (SI-NETs) are serotonin-secreting well-differentiated neuroendocrine tumors believed to originate from enterochromaffin (EC) cells. Intestinal stem cell (ISC) are believed to contribute to the formation of SI-NETs, although little is known about tumor formation or development. We investigated the relationship between EC cells, ISCs, and SI-NETs. METHODS We analyzed jejuno-ileal tissue specimens from 14 patients with familial SI-NETs enrolled in the Natural History of Familial Carcinoid Tumor study at the National Institutes of Health from January 2009 to December 2014. Frozen and paraffin-embedded tumor tissues of different stages and isolated crypts were analyzed by in situ hybridization and immunohistochemistry. Tumor clonality was assessed by analyses of mitochondrial DNA. RESULTS We identified multifocal aberrant crypt-containing endocrine cell clusters (ACECs) that contain crypt EC cell microtumors in patients with familial SI-NETs. RNA in situ hybridization revealed expression of the EC cell and reserve stem cell genes TPH1, BMI1, HOPX, and LGR5(low), in the ACECs and more advanced extraepithelial tumor nests. This expression pattern resembled that of reserve EC cells that express reserve ISC genes; most reside at the +4 position in normal crypts. The presence of multifocal ACECs from separate tumors and in the macroscopic tumor-free mucosa indicated widespread, independent, multifocal tumorigenesis. Analyses of mitochondrial DNA confirmed the independent origin of the ACECs. CONCLUSIONS Familial SI-NETs originate from a subset of EC cells (reserve EC cells that express reserve ISC genes) via multifocal and polyclonal processes. Increasing our understanding of the role of these reserve EC cells in the genesis of multifocal SI-NETs could improve diagnostic and therapeutic strategies for this otherwise intractable disease.
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Affiliation(s)
- Yoshitatsu Sei
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Jianying Feng
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Xilin Zhao
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Joanne Forbes
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Derek Tang
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Kunio Nagashima
- Electron Microscopy Laboratory, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701
| | - Jeffrey Hanson
- Laboratory of Pathology, National Cancer Institute, National Institutes of Health
| | - Martha M. Quezado
- Laboratory of Pathology, National Cancer Institute, National Institutes of Health
| | - Marybeth S. Hughes
- Surgery Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-1804
| | - Stephen A. Wank
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-1804,To whom correspondence should be addressed. Stephen A. Wank, M.D., Address: DDB/NIDDK/NIH, 10/9C-101, Bethesda, MD 20892, , Phone: (301) 402-3704
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Hughes MS, Azoury SC, Assadipour Y, Straughan DM, Trivedi AN, Lim RM, Joy G, Voellinger MT, Tang DM, Venkatesan AM, Chen CC, Louie A, Quezado MM, Forbes J, Wank SA. Prospective evaluation and treatment of familial carcinoid small intestine neuroendocrine tumors (SI-NETs). Surgery 2015; 159:350-6. [PMID: 26454678 DOI: 10.1016/j.surg.2015.05.041] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 04/22/2015] [Accepted: 05/13/2015] [Indexed: 01/17/2023]
Abstract
BACKGROUND The aim of this study was to prospectively screen patients with a positive family history of carcinoid small intestine neuroendocrine tumors (SI-NETs) to elucidate the benefits of early detection and operative intervention. METHODS A single-center, prospective trial was conducted from 2008 to 2014 that evaluated patients with 2 or more blood relatives with carcinoid SI-NETs. All eligible patients were screened with urine/serum biochemistries and various imaging modalities. Operative intervention was elected in patients found to have at least 1 positive diagnostic study. RESULTS Twenty-nine patients from 13 families had occult carcinoid SI-NETs (15 female, 14 male). Twenty-four of the 29 patients (83%) had multifocal disease found in either the distal jejunum or ileum. On average, 75.9 cm (range, 13-195) of bowel was resected in 1 segment. Three patients were found to have stage IV disease at operation. All stage I-IIIB patients who had R0 resections have remained disease-free, with a median follow-up of 35 months. CONCLUSION Familial carcinoid SI-NETs often are asymptomatic and can be diagnosed with aggressive screening. With early detection, there may be a window of opportunity for operative resection to change the natural history of this disease and even prove to be curative.
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Affiliation(s)
- Marybeth S Hughes
- Thoracic and Gastrointestinal Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD.
| | - Saïd C Azoury
- Thoracic and Gastrointestinal Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Yasmine Assadipour
- Thoracic and Gastrointestinal Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - David M Straughan
- Thoracic and Gastrointestinal Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Apurva N Trivedi
- Digestive Diseases Branch, National Institute of Diabetes, Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD
| | - Ramona M Lim
- Digestive Diseases Branch, National Institute of Diabetes, Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD
| | - Grishma Joy
- Digestive Diseases Branch, National Institute of Diabetes, Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD
| | - Mark T Voellinger
- Digestive Diseases Branch, National Institute of Diabetes, Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD
| | - Derek M Tang
- Digestive Diseases Branch, National Institute of Diabetes, Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD
| | | | - Clara C Chen
- Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD
| | - Adeline Louie
- Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD
| | - Martha M Quezado
- Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Joanne Forbes
- Digestive Diseases Branch, National Institute of Diabetes, Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD
| | - Stephen A Wank
- Digestive Diseases Branch, National Institute of Diabetes, Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD
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15
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Sei Y, Zhao X, Forbes J, Szymczak S, Li Q, Trivedi A, Voellinger M, Joy G, Feng J, Whatley M, Jones MS, Harper UL, Marx SJ, Venkatesan AM, Chandrasekharappa SC, Raffeld M, Quezado MM, Louie A, Chen CC, Lim RM, Agarwala R, Schäffer AA, Hughes MS, Bailey-Wilson JE, Wank SA. A Hereditary Form of Small Intestinal Carcinoid Associated With a Germline Mutation in Inositol Polyphosphate Multikinase. Gastroenterology 2015; 149:67-78. [PMID: 25865046 PMCID: PMC4858647 DOI: 10.1053/j.gastro.2015.04.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 03/26/2015] [Accepted: 04/02/2015] [Indexed: 01/07/2023]
Abstract
BACKGROUND & AIMS Small intestinal carcinoids are rare and difficult to diagnose and patients often present with advanced incurable disease. Although the disease occurs sporadically, there have been reports of family clusters. Hereditary small intestinal carcinoid has not been recognized and genetic factors have not been identified. We performed a genetic analysis of families with small intestinal carcinoids to establish a hereditary basis and find genes that might cause this cancer. METHODS We performed a prospective study of 33 families with at least 2 cases of small intestinal carcinoids. Affected members were characterized clinically and asymptomatic relatives were screened and underwent exploratory laparotomy for suspected tumors. Disease-associated mutations were sought using linkage analysis, whole-exome sequencing, and copy number analyses of germline and tumor DNA collected from members of a single large family. We assessed expression of mutant protein, protein activity, and regulation of apoptosis and senescence in lymphoblasts derived from the cases. RESULTS Familial and sporadic carcinoids are clinically indistinguishable except for the multiple synchronous primary tumors observed in most familial cases. Nearly 34% of asymptomatic relatives older than age 50 were found to have occult tumors; the tumors were cleared surgically from 87% of these individuals (20 of 23). Linkage analysis and whole-exome sequencing identified a germline 4-bp deletion in the gene inositol polyphosphate multikinase (IPMK), which truncates the protein. This mutation was detected in all 11 individuals with small intestinal carcinoids and in 17 of 35 family members whose carcinoid status was unknown. Mutant IPMK had reduced kinase activity and nuclear localization, compared with the full-length protein. This reduced activation of p53 and increased cell survival. CONCLUSIONS We found that small intestinal carcinoids can occur as an inherited autosomal-dominant disease. The familial form is characterized by multiple synchronous primary tumors, which might account for 22%-35% of cases previously considered sporadic. Relatives of patients with familial carcinoids should be screened to detect curable early stage disease. IPMK haploinsufficiency promotes carcinoid tumorigenesis.
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Affiliation(s)
- Yoshitatsu Sei
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD, USA
| | - Xilin Zhao
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD, USA
| | - Joanne Forbes
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD, USA
| | - Silke Szymczak
- Computational and Statistical Genomics Branch, NHGRI, National Institutes of Health, Bethesda, MD, USA
| | - Qing Li
- Computational and Statistical Genomics Branch, NHGRI, National Institutes of Health, Bethesda, MD, USA
| | - Apurva Trivedi
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD, USA
| | - Mark Voellinger
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD, USA
| | - Grishma Joy
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD, USA
| | - Jianying Feng
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD, USA
| | - Millie Whatley
- Nuclear Medicine Division, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - MaryPat Sussex Jones
- Genomics Core/Genome Technology Branch, NHGRI, National Institutes of Health, Bethesda, MD, USA
| | - Ursula L. Harper
- Genomics Core/Genome Technology Branch, NHGRI, National Institutes of Health, Bethesda, MD, USA
| | - Stephen J. Marx
- Metabolic Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD, USA
| | - Aradhana M. Venkatesan
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | | | - Mark Raffeld
- Laboratory of Pathology, NCI, National Institutes of Health, Bethesda, MD, USA
| | - Martha M. Quezado
- Laboratory of Pathology, NCI, National Institutes of Health, Bethesda, MD, USA
| | - Adeline Louie
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Clara C. Chen
- Nuclear Medicine Division, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Ramona M. Lim
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD, USA
| | - Richa Agarwala
- Information Engineering Branch, NCBI, NLM, National Institutes of Health, Bethesda, MD, USA
| | - Alejandro A. Schäffer
- Computational Biology Branch, NCBI, NLM, National Institutes of Health, Bethesda, MD, USA
| | | | - Joan E. Bailey-Wilson
- Computational and Statistical Genomics Branch, NHGRI, National Institutes of Health, Bethesda, MD, USA
| | - Stephen A. Wank
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD, USA,To whom correspondence should be addressed: Stephen A. Wank, M.D., Address: DDB/NIDDK/NIH, 10/9C-101, Bethesda, MD 20892, , Phone: (301) 402-3704, Fax: (301) 480-7476
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Yang Y, Evans S, Escano C, Asico L, Zhang Y, Gonzalez SC, Villar VA, Wang X, Pisegna JR, Wank SA, Armando I, Jose P. Expression of gastrin in the thin descending limb of Henle's loop in the mouse kidney: a molecular, localization, and functional study. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.688.4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yu Yang
- Center for Molecular Physiology ResearchChildren's National Medical CenterGeorge Washington UniversityWashingtonDC
| | - Sarah Evans
- Center for Molecular Physiology ResearchChildren's National Medical CenterGeorge Washington UniversityWashingtonDC
| | - Crisanto Escano
- Center for Molecular Physiology ResearchChildren's National Medical CenterGeorge Washington UniversityWashingtonDC
| | - Laureano Asico
- Center for Molecular Physiology ResearchChildren's National Medical CenterGeorge Washington UniversityWashingtonDC
| | - Yanrong Zhang
- Center for Molecular Physiology ResearchChildren's National Medical CenterGeorge Washington UniversityWashingtonDC
| | - Santiago Cuevas Gonzalez
- Center for Molecular Physiology ResearchChildren's National Medical CenterGeorge Washington UniversityWashingtonDC
| | - Van Anthony Villar
- Center for Molecular Physiology ResearchChildren's National Medical CenterGeorge Washington UniversityWashingtonDC
| | - Xiaoyan Wang
- Center for Molecular Physiology ResearchChildren's National Medical CenterGeorge Washington UniversityWashingtonDC
| | | | - Stephen A. Wank
- Gastrointestinal Cell Biology SectionNIDDKNational Institutes of HealthBethesdaMD
| | - Ines Armando
- Center for Molecular Physiology ResearchChildren's National Medical CenterGeorge Washington UniversityWashingtonDC
| | - Pedro Jose
- Center for Molecular Physiology ResearchChildren's National Medical CenterGeorge Washington UniversityWashingtonDC
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Liou AP, Chavez DI, Espero E, Hao S, Wank SA, Raybould HE. Protein hydrolysate-induced cholecystokinin secretion from enteroendocrine cells is indirectly mediated by the intestinal oligopeptide transporter PepT1. Am J Physiol Gastrointest Liver Physiol 2011; 300:G895-902. [PMID: 21311026 PMCID: PMC3094145 DOI: 10.1152/ajpgi.00521.2010] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Dietary protein is a major stimulant for cholecystokinin (CCK) secretion by the intestinal I cell, however, the mechanism by which protein is detected is unknown. Indirect functional evidence suggests that PepT1 may play a role in CCK-mediated changes in gastric motor function. However, it is unclear whether this oligopeptide transporter directly or indirectly activates the I cell. Using both the CCK-expressing enteroendocrine STC-1 cell and acutely isolated native I cells from CCK-enhanced green fluorescent protein (eGFP) mice, we aimed to determine whether PepT1 directly activates the enteroendocrine cell to elicit CCK secretion in response to oligopeptides. Both STC-1 cells and isolated CCK-eGFP cells expressed PepT1 transcripts. STC-1 cells were activated, as measured by ERK(1/2) phosphorylation, by both peptone and the PepT1 substrate Cefaclor; however, the PepT1 inhibitor 4-aminomethyl benzoic acid (AMBA) had no effect on STC-1 cell activity. The PepT1-transportable substrate glycyl-sarcosine dose-dependently decreased gastric motility in anesthetized rats but had no affect on activation of STC-1 cells or on CCK secretion by CCK-eGFP cells. CCK secretion was significantly increased in response to peptone but not to Cefaclor, cephalexin, or Phe-Ala in CCK-eGFP cells. Taken together, the data suggest that PepT1 does not directly mediate CCK secretion in response to PepT1 specific substrates. PepT1, instead, may have an indirect role in protein sensing in the intestine.
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Affiliation(s)
- Alice P. Liou
- 1Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, California; and ,2Digestive Diseases Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Diana I. Chavez
- 1Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, California; and
| | - Elvis Espero
- 1Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, California; and
| | - Shuzhen Hao
- 1Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, California; and
| | - Stephen A. Wank
- 2Digestive Diseases Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Helen E. Raybould
- 1Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, California; and
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Liou AP, Sei Y, Zhao X, Feng J, Lu X, Thomas C, Pechhold S, Raybould HE, Wank SA. The extracellular calcium-sensing receptor is required for cholecystokinin secretion in response to L-phenylalanine in acutely isolated intestinal I cells. Am J Physiol Gastrointest Liver Physiol 2011; 300:G538-46. [PMID: 21252045 PMCID: PMC3074990 DOI: 10.1152/ajpgi.00342.2010] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The extracellular calcium-sensing receptor (CaSR) has recently been recognized as an L-amino acid sensor and has been implicated in mediating cholecystokinin (CCK) secretion in response to aromatic amino acids. We investigated whether direct detection of L-phenylalanine (L-Phe) by CaSR results in CCK secretion in the native I cell. Fluorescence-activated cell sorting of duodenal I cells from CCK-enhanced green fluorescent protein (eGFP) transgenic mice demonstrated CaSR gene expression. Immunostaining of fixed and fresh duodenal tissue sections confirmed CaSR protein expression. Intracellular calcium fluxes were CaSR dependent, stereoselective for L-Phe over D-Phe, and responsive to type II calcimimetic cinacalcet in CCK-eGFP cells. Additionally, CCK secretion by an isolated I cell population was increased by 30 and 62% in response to L-Phe in the presence of physiological (1.26 mM) and superphysiological (2.5 mM) extracellular calcium concentrations, respectively. While the deletion of CaSR from CCK-eGFP cells did not affect basal CCK secretion, the effect of L-Phe or cinacalcet on intracellular calcium flux was lost. In fact, both secretagogues, as well as superphysiological Ca(2+), evoked an unexpected 20-30% decrease in CCK secretion compared with basal secretion in CaSR(-/-) CCK-eGFP cells. CCK secretion in response to KCl or tryptone was unaffected by the absence of CaSR. The present data suggest that CaSR is required for hormone secretion in the specific response to L-Phe by the native I cell, and that a receptor-mediated mechanism may inhibit hormone secretion in the absence of a fully functional CaSR.
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Affiliation(s)
- Alice P. Liou
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; ,2School of Veterinary Medicine, Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, Davis, California; and
| | - Yoshitatsu Sei
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Xilin Zhao
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Jianying Feng
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Xinping Lu
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Craig Thomas
- 3Chemical Genomics Center, National Human Genome Research Institute, and
| | - Susanne Pechhold
- 4Diabetes Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Helen E. Raybould
- 2School of Veterinary Medicine, Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, Davis, California; and
| | - Stephen A. Wank
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
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19
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Sei Y, Lu X, Liou A, Zhao X, Wank SA. A stem cell marker-expressing subset of enteroendocrine cells resides at the crypt base in the small intestine. Am J Physiol Gastrointest Liver Physiol 2011; 300:G345-56. [PMID: 21088235 PMCID: PMC3043655 DOI: 10.1152/ajpgi.00278.2010] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The spatial orientation of the enteroendocrine cells along the crypt-villus axis is closely associated with their differentiation in the intestine. Here we studied this relationship using primary duodenal crypts and an ex vivo organoid system established from cholecystokinin-green fluorescent protein (CCK-GFP) transgenic mice. In the primary duodenal crypts, GFP+ cells were found not only in the upper crypt but also at the crypt base, where the stem cells reside. Many GFP+ cells below +4 position were positive for the putative intestinal stem cell markers, leucine-rich repeat-containing G protein-coupled receptor 5, CD133, and doublecortin and CaM kinase-like-1, and also for the neuroendocrine transcription factor neurogenin 3. However, these cells were neither stem nor transient amplifying precursor cells because they were negative for both Ki-67 and phospho-Histone H3 and positive for the mature endocrine marker chromogranin A. Furthermore, these cells expressed multiple endocrine hormones. Tracking of GFP+ cells in the organoids from CCK-GFP mice indicated that GFP+ cells were first observed around the +4 position, some of which localized to the crypt base later in the culture period. These results suggest that a subset of enteroendocrine cells migrates down to the crypt base or stays localized at the crypt base, where they express stem and postmitotic endocrine markers. Further investigation of the function of this subset may provide novel insights into the genesis and development of enteroendocrine cells as well as enteroendocrine tumorigenesis.
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Affiliation(s)
- Yoshitatsu Sei
- Gastroenterology Section, DDB, National Institute of Diabetes, Digestive & Kidney Diseases, 10 Center Dr., Bldg 10, Rm. 9C-112, MSC1804, Bethesda, MD 20892-1385, USA.
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20
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Parkhurst MR, Yang JC, Langan RC, Dudley ME, Nathan DAN, Feldman SA, Davis JL, Morgan RA, Merino MJ, Sherry RM, Hughes MS, Kammula US, Phan GQ, Lim RM, Wank SA, Restifo NP, Robbins PF, Laurencot CM, Rosenberg SA. T cells targeting carcinoembryonic antigen can mediate regression of metastatic colorectal cancer but induce severe transient colitis. Mol Ther 2010; 19:620-6. [PMID: 21157437 DOI: 10.1038/mt.2010.272] [Citation(s) in RCA: 731] [Impact Index Per Article: 52.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Autologous T lymphocytes genetically engineered to express a murine T cell receptor (TCR) against human carcinoembryonic antigen (CEA) were administered to three patients with metastatic colorectal cancer refractory to standard treatments. All patients experienced profound decreases in serum CEA levels (74-99%), and one patient had an objective regression of cancer metastatic to the lung and liver. However, a severe transient inflammatory colitis that represented a dose limiting toxicity was induced in all three patients. This report represents the first example of objective regression of metastatic colorectal cancer mediated by adoptive T cell transfer and illustrates the successful use of a TCR, raised in human leukocyte antigen (HLA) transgenic mice, against a human tumor associated antigen. It also emphasizes the destructive power of small numbers of highly avid T cells and the limitations of using CEA as a target for cancer immunotherapy.
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Affiliation(s)
- Maria R Parkhurst
- Surgery Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
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21
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von Rosenvinge EC, Wank SA, Lim RM. Gastric masses in multiple endocrine neoplasia type I-associated Zollinger-Ellison syndrome. Gastroenterology 2009; 137:1222, 537. [PMID: 19723598 DOI: 10.1053/j.gastro.2009.03.050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 03/09/2009] [Accepted: 03/19/2009] [Indexed: 12/20/2022]
Affiliation(s)
- Erik C von Rosenvinge
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
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22
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Fitzsimmons TJ, Zhao X, Wank SA. The extracellular domain of receptor activity-modifying protein 1 is sufficient for calcitonin receptor-like receptor function. J Biol Chem 2003; 278:14313-20. [PMID: 12574158 DOI: 10.1074/jbc.m211946200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A functional calcitonin gene-related peptide (CGRP) receptor requires dimerization of calcitonin receptor-like receptor (CRLR) with receptor activity-modifying protein 1 (RAMP 1). To determine the function of the three domains (extracellular, ECD; transmembrane, TM; and tail domains) of human RAMP 1, three mutants were constructed: RAMP 1 without the cytoplasmic tail, a chimera consisting of the ECD of RAMP 1 and the TM and tail of the platelet-derived growth factor receptor, and the ECD of RAMP 1 alone. These RAMP 1 mutants were examined for their ability to associate with CRLR to effect CGRP-stimulated cAMP accumulation, CGRP binding, CRLR trafficking, and cell surface expression. All RAMP 1 mutants were able to associate with CRLR with full efficacy for CGRP-stimulated cAMP accumulation. However, the RAMP 1/platelet-derived growth factor receptor chimera demonstrated a 10-fold decrease in potency for CGRP signaling and binding, and the RAMP 1-ECD mutant had a 4000-fold decrease in potency. In conclusion, the ECD of RAMP 1 is sufficient for normal CRLR association and efficacy. The presence of a TM domain and the specific sequence of the RAMP 1 TM domain contribute to CGRP affinity and potency. The C-terminal tail of RAMP 1 is unnecessary for CRLR function.
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Affiliation(s)
- Timothy J Fitzsimmons
- Digestive Diseases Branch, National Institute Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-1804, USA
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23
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Wank SA. PACAP upsets stomach theory. J Clin Invest 1999. [DOI: 10.1172/jci8732e1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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24
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Noble F, Wank SA, Crawley JN, Bradwejn J, Seroogy KB, Hamon M, Roques BP. International Union of Pharmacology. XXI. Structure, distribution, and functions of cholecystokinin receptors. Pharmacol Rev 1999; 51:745-81. [PMID: 10581329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Affiliation(s)
- F Noble
- Institut National de la Santé et de la Recherche Médicale U266, Centre National de la Recherche Scientifique UMR 8600, Université René Descartes, Paris, France
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25
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Affiliation(s)
- S A Wank
- Digestive Diseases Branch, National Institute of Diabetes, Kidney and Digestive Diseases, National Institutes of Health, Building 10, Room 9C-103, 9000 Rockville Pike, Bethesda, Maryland 20892-1804, USA.
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26
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Silvente-Poirot S, Escrieut C, Galès C, Fehrentz JA, Escherich A, Wank SA, Martinez J, Moroder L, Maigret B, Bouisson M, Vaysse N, Fourmy D. Evidence for a direct interaction between the penultimate aspartic acid of cholecystokinin and histidine 207, located in the second extracellular loop of the cholecystokinin B receptor. J Biol Chem 1999; 274:23191-7. [PMID: 10438490 DOI: 10.1074/jbc.274.33.23191] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recently, we reported that the mutation of His(207) to Phe located in the second extracellular loop of the cholecystokinin B receptor strongly affected cholecystokinin (CCK) binding (Silvente-Poirot, S., Escrieut, C., and Wank, S. A. (1998) Mol. Pharmacol. 54, 364-371). To characterize the functional group in CCK that interacts with His(207), we first substituted His(207) to Ala. This mutation decreased the affinity and the potency of CCK to produce total inositol phosphates 302-fold and 456-fold without affecting the expression of the mutant receptor. The screening of L-alanine-modified CCK peptides to bind and activate the wild type and mutant receptors allowed the identification of the interaction of the C-terminal Asp(8) of CCK with His(207). The H207A-CCKBR mutant, unlike the wild type receptor, was insensitive to substitution of Asp(8) of CCK to other amino acid residues. This interaction was further confirmed by mutating His(207) to Asp. The affinity of CCK for the H207D-CCKBR mutant was 100-fold lower than for the H207A-CCKBR mutant, consistent with an electrostatic repulsion between the negative charges of the two interacting aspartic acids. Peptides with neutral amino acids in position eight of CCK reversed this effect and displayed a gain of affinity for the H207D mutant compared with CCK. To date, this is the first report concerning the identification of a direct contact point between the CCKB receptor and CCK.
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Affiliation(s)
- S Silvente-Poirot
- INSERM U 151, Institute Louis Bugnart, CHU Rangueil, Bat L3, 31403 Toulouse Cedex, France.
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27
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Arudchandran R, Brown MJ, Song JS, Wank SA, Haleem-Smith H, Rivera J. Polyethylene glycol-mediated infection of non-permissive mammalian cells with semliki forest virus: application to signal transduction studies. J Immunol Methods 1999; 222:197-208. [PMID: 10022386 DOI: 10.1016/s0022-1759(98)00161-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Semliki Forest Virus (SFV) vectors allow the subcloning of a gene of interest directly in the expression vector, thus avoiding the need to select and purify viral recombinants, making this viral expression system attractive over many others for mammalian protein expression. We now describe a novel and generally applicable method for infection of non-permissive mammalian cells with SFV, that greatly enhances the utility of this expression system. We demonstrate that the hygroscopic polymer poly (ethylene glycol), PEG, promotes the infectivity of cells by SFV under conditions that did not promote cell-cell fusion. We also found that the PEG-induced infection and expression of an exogenous protein (green fluorescent protein, GFP) did not elevate the basal tyrosine kinase activity, induce a stress-activated responses, or result in aberrant cell responses. Expression of GFP tagged-Vav, an activator of stress-activated protein kinase (SAPK/JNK), resulted in the expected induction of JNK activity and in the normal redistribution of Vav in response to engagement of the high affinity receptor for IgE (FcepsilonRI). Thus, our findings that PEG allows the infection of non-permissive cells by SFV makes this system extremely attractive for expression of proteins in mammalian cells, and studies on signal transduction and cellular localization in immune and non-immune cells.
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Affiliation(s)
- R Arudchandran
- Section on Chemical Immunology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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28
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Abstract
The cholecystokinin (CCK) receptor types A and B (CCKAR and CCKBR) are G protein-coupled receptors with approximately 50% amino acid identity; both have high affinity for the sulfated CCK octapeptide (CCK-8), whereas only the CCKBR has high affinity for gastrin. Previously, we identified five amino acids in the second extracellular loop (ECL) of the CCKBR that were essential for gastrin selectivity. Subsequent mutagenesis of one of these five amino acids (H207F) resulted in the loss of radiolabeled CCK-8 binding. CCK-8 stimulated total inositol phosphate accumulation in COS-1 cells transiently expressing the CCKBR-H207F with full efficacy and a 3044-fold reduced potency, which suggests that the loss of radioligand binding was caused by a loss in affinity. Alanine scanning mutagenesis was performed on the amino terminus near the top of transmembrane domain I (TMI) and on ECL1, two extracellular domains implicated in ligand binding by previous mutagenesis studies. 125I-Bolton-Hunter-CCK-8 binding to mutant receptors transiently expressed in COS-1 identified one nonconserved amino acid, R57A, at the top of TMI that caused a 21-fold reduction in CCK-8 affinity and four conserved amino acids, N115A, L116A, F120A and F122A, in the ECL1 that caused a 15.6-, 6-, 440-, and 8-fold reduction in affinity or efficacy. Alanine substitution of the equivalent amino acids in the CCKAR corresponding to each of the five amino acids in ECL1 and ECL2 affecting CCK-8 affinity for the CCKBR revealed only two mutations, L103A and F107A, that decreased CCK-8 affinity (68- and 2885-fold, respectively). These data suggest that CCK-8 interacts at multiple contact points in the extracellular domains of CCK receptors and that the CCKAR and CCKBR have distinct binding sites despite their shared high affinity for CCK-8.
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Affiliation(s)
- S Silvente-Poirot
- Institut National de la Santé et de la Recherche Médicale U 151, CHU Rangueil, Bat L3, 31403 Toulouse Cedex, France
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Harmar AJ, Arimura A, Gozes I, Journot L, Laburthe M, Pisegna JR, Rawlings SR, Robberecht P, Said SI, Sreedharan SP, Wank SA, Waschek JA. International Union of Pharmacology. XVIII. Nomenclature of receptors for vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide. Pharmacol Rev 1998; 50:265-70. [PMID: 9647867 PMCID: PMC6721840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Affiliation(s)
- A J Harmar
- MRC Brain Metabolism Unit, Royal Edinburgh Hospital, Scotland, UK.
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30
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Pohl M, Wank SA. Molecular cloning of the helodermin and exendin-4 cDNAs in the lizard. Relationship to vasoactive intestinal polypeptide/pituitary adenylate cyclase activating polypeptide and glucagon-like peptide 1 and evidence against the existence of mammalian homologues. J Biol Chem 1998; 273:9778-84. [PMID: 9545315 DOI: 10.1074/jbc.273.16.9778] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Helodermin and exendin-4, two peptides isolated from the salivary gland of the Gila monster, Heloderma suspectum, are approximately 50% homologous to vasoactive intestinal peptide (VIP) and glucagon-like peptide-1 (GLP-1), respectively, and interact with the mammalian receptors for VIP and GLP-1 with equal or higher affinity and efficacy. Immunohistochemical studies suggested the presence of helodermin-like peptides in mammals. To determine whether helodermin and exendin-4 are present in mammals and their evolutionary relationship to VIP and GLP-1, their cDNAs were first cloned from Gila monster salivary gland. Northern blots and reverse transcription-polymerase chain reaction of multiple Gila monster tissues identified approximately 500-base pair transcripts only from salivary gland. Both helodermin and exendin-4 full-length cDNAs were approximately 500 base pairs long, and they encoded precursor proteins containing the entire amino acid sequence of helodermin and exendin-4, as well as a 44- or 45-amino acid N-terminal extension peptide, respectively, having approximately 60% homology. The size and structural organization of these cDNAs indicated that they were closely related to one another but markedly different from known cDNAs for the VIP/GLP-1 peptide family previously identified in both lower and higher evolved species. Cloning of the Gila monster VIP/peptide histidine isoleucine, pituitary adenylate cyclase activating polypeptide, and glucagon/GLP-1 cDNAs and Southern blotting of Gila monster DNA demonstrate the coexistence of separate genes for these peptides and suggests, along with the restricted salivary gland expression, that helodermin and exendin-4 coevolved to serve a separate specialized function. Probing of a variety of rat and human tissues on Northern blots, human and rat Southern blots, and genomic and cDNA libraries with either helodermin- or exendin-4-specific cDNAs failed to identify evidence for mammalian homologues. These data indicate that helodermin and exendin-4 are not the precursors to VIP and GLP-1 and that they belong to a separate peptide family encoded by separate genes. Furthermore, the existence of as yet undiscovered mammalian homologues to helodermin and exendin-4 seems unlikely.
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Affiliation(s)
- M Pohl
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892, USA
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31
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Abstract
The CCK and gastrin families of peptides act as hormones and neuropeptides on central and peripheral receptors to mediate secretion and motility in the gastrointestinal tract in the physiological response to a normal meal. Thus far, two CCK receptors have been molecularly identified to mediate the actions of CCK and gastrin, CCK-A and CCK-B receptors (CCK-AR and CCK-BR, respectively). The regulation of CCK-AR and CCK-BR affinity by guanine nucleotides and the receptor activation of G protein-dependent stimulation of phospholipase C and adenylyl cyclase suggested that they were guanine nucleotide-binding protein-coupled receptors [G protein-coupled receptors (GPCRs)]; however, the eventual cloning of their cDNAs revealed their heptahelical structure and confirmed their membership in the GPCR superfamily. The gastrointestinal system is a rich source of neuroendocrine hormones that interact with a large number of GPCRs to regulate the complex tasks of digestion, absorption, and excretion of a meal. This article focuses on the CCK family of GPCRs, and its activities in the gastrointestinal system.
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Affiliation(s)
- S A Wank
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-1804, USA
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32
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Pohl M, Silvente-Poirot S, Pisegna JR, Tarasova NI, Wank SA. Ligand-induced internalization of cholecystokinin receptors. Demonstration of the importance of the carboxyl terminus for ligand-induced internalization of the rat cholecystokinin type B receptor but not the type A receptor. J Biol Chem 1997; 272:18179-84. [PMID: 9218453 PMCID: PMC6721839 DOI: 10.1074/jbc.272.29.18179] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Internalization of a variety of different heptahelical G protein-coupled receptors has been shown to be influenced by a number of different structural determinants of the receptors, including the carboxyl terminus. To investigate the role of the carboxyl terminus of cholecystokinin (CCK) receptors in receptor internalization, the rat wild type (WT) CCK-A receptor (WT CCKAR) and the rat WT CCK-B receptor (WT CCKBR) were truncated after amino acid residue 399 (CCKAR Tr399) and 408 (CCKBR Tr408), thereby deleting the carboxyl-terminal 45 and 44 residues, respectively. All WT and mutant CCK receptors were stably expressed in NIH/3T3 cells. Internalization of the CCKAR Tr399 was not significantly different from the WT CCKAR. In contrast, internalization of the CCKBR Tr408 was decreased to 26% compared with the WT CCKBR internalization of 92%. The mutation of all 10 serine and threonine residues (as potential phosphorylation sites) in the carboxyl terminus of the CCKBR to alanines (mutant CCKBR DeltaS/T) could account for the majority of this effect (39% internalization). All mutant receptors displayed similar ligand binding characteristics, G protein coupling, and signal transduction as their respective WT receptors, indicating that the carboxyl termini are not necessary for these processes. Thus, internalization of the CCKBR, unlike that of the CCKAR, depends on the carboxyl terminus of the receptor. These results suggest that, despite the high degree of homology between CCKAR and CCKBR, the structural determinants that mediate the interaction with the endocytic pathway reside in different regions of the receptors.
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Affiliation(s)
- M Pohl
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892, USA
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33
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Tarasova NI, Stauber RH, Choi JK, Hudson EA, Czerwinski G, Miller JL, Pavlakis GN, Michejda CJ, Wank SA. Visualization of G protein-coupled receptor trafficking with the aid of the green fluorescent protein. Endocytosis and recycling of cholecystokinin receptor type A. J Biol Chem 1997; 272:14817-24. [PMID: 9169450 DOI: 10.1074/jbc.272.23.14817] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A chimeric protein consisting of the cholecystokinin receptor type A (CCKAR) and the green fluorescent protein (GFP) was used for studying receptor localization, internalization, and recycling in live cells in real time in four different cell lines. Fusion of the C terminus of the CCKAR to the N terminus of the GFP did not alter receptor ligand binding affinity, signal transduction, or the pattern of receptor surface expression and receptor-mediated cholecystokinin (CCK) internalization. The use of a new GFP mutant with increased fluorescence allowed the continuous observation of CCKAR-GFP in stably expressing cell lines. Newly obtained biologically active fluorescent derivatives of CCK were used for simultaneous observation of receptor and ligand trafficking in CHO, NIH/3T3, and HeLa cells stably expressing the fluorescent CCKAR and in transiently transfected COS-1 cells. Receptor internalization was predominantly ligand dependent in HeLa, COS-1, and CHO cells, but was mostly constitutive in NIH/3T3 cells, suggesting the existence of cell-specific regulation of receptor internalization. The CCKAR antagonists, L-364,718 and CCK 27-32 amide potently inhibited spontaneous internalization of the receptor. The average sorting time of CCK and the receptor in the endosomes was about 25 min. The receptor recycled back to the cell membrane with an average time of 60 min. While the ligands sorted to lysosomes, no receptor molecules could be detected there, and no receptor degradation was observed during recycling. These results demonstrate the usefulness of GFP tagging for real time imaging of G protein-coupled receptor trafficking in living cells and suggest that this technique may be successfully applied to the study of the regulation and trafficking mechanisms of other receptors.
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Affiliation(s)
- N I Tarasova
- Molecular Aspects of Drug Design Section, ABL-Basic Research Program, NCI-Frederick Cancer Research and Development Center, Frederick, Maryland 21702, USA
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34
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Tarasova NI, Wank SA, Hudson EA, Romanov VI, Czerwinski G, Resau JH, Michejda CJ. Endocytosis of gastrin in cancer cells expressing gastrin/CCK-B receptor. Cell Tissue Res 1997; 287:325-33. [PMID: 8995203 DOI: 10.1007/s004410050757] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Endocytosis of gastrin was studied in a number of gastrin-receptor-expressing cell lines by confocal laser scanning microscopy (CLSM) with the aid of a biologically active fluorescent derivative, rhodamine green heptagastrin. Rapid clustering (within 4-7 min) and internalization of fluorescent ligand upon binding at room temperature and 37 degrees C were observed in the rat pancreatic acinar carcinoma cell line AR42J, human gastric carcinomas AGS-P and SIIA, human colon carcinomas HCT116 and HT29, and in NIH/3T3 cells transfected with human and rat gastrin/cholecystokinin-B receptor cDNA. Internalization was inhibited by hypertonic medium. Fluorescent heptagastrin and transferrin colocalized in the same endocytic vesicles at different stages of internalization suggesting that endocytosis occurred predominantly through a clathrin-dependent mechanism. At 37 degrees C partial colocalization with the lysosomal marker neutral red was detected by CLSM, implying that internalized gastrin accumulated in the lysosomes. Immunoelectron microscopy studies with antibodies against gastrin revealed the presence of the internalized hormone in multivesicular vesicles and endosomes. Almost no hormone was detected in lysosomes with the antibodies to gastrin, suggesting that the degradation of the peptide is rapid in those vesicles. Continuous accumulation of fluorescent label was observed by CLSM in the presence of the protein synthesis inhibitor cycloheximide, suggesting that the gastrin receptor is recycled back to the cell membrane after hormone delivery to intracellular compartments. An estimated average recycling time for the receptor molecules was 1 h in NIH/3T3 cells.
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Affiliation(s)
- N I Tarasova
- Molecular Aspects of Drug Design Section, ABL-Basic Research Program, National Cancer Institute, Frederick Cancer Research and Development Center, P.O. Box B, Frederick, MD 21702, USA
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35
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Pisegna JR, Moody TW, Wank SA. Differential signaling and immediate-early gene activation by four splice variants of the human pituitary adenylate cyclase-activating polypeptide receptor (hPACAP-R). Ann N Y Acad Sci 1996; 805:54-64; discussion 64-6. [PMID: 8993393 PMCID: PMC6736521 DOI: 10.1111/j.1749-6632.1996.tb17473.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP), a neuropeptide belonging to the VIP/secretin/glucagon family, is present in the hypothalamus, anterior pituitary, and adrenal gland where it regulates hormone release, in the GI tract where it modulates motility, and in human tumoral cell lines where it shows a growth-promoting effect. It is now appreciated that alternative splicing of two exons of the rat PACAP-R gene generate four major rPACAP-R splice variants that are differentially expressed in tissues and variably coupled to intracellular second messengers. Because of the potential implications of these findings in human physiology, we cloned the hPACAP-R gene. Similar to the rat, two exons (SV-1 and SV-2) are alternatively spliced to account for four major hPACAP-R receptor splice variants. These splice variants (hPACAP-R-null, hPACAP-R-SV1, hPACAP-R-SV2, hPACAP-R-SV-3) were cloned from a human frontal cortex cDNA library, stably transfected in NIH/ 3T3 cells and each characterized for ligand affinity, stimulation of adenylate cyclase (AC) and phospholipase C (PLC), and ligand-induced expression of the proto-oncogenes, c-fos, and c-myc. Stably transfected NIH/3T3 cells expressing similar numbers of receptors of the four splice variants showed nearly identical responses for ligand affinity and potency for P-38- and P-27-stimulated increases in cAMP and total inositol phosphates. However, each receptor splice variant differed in their ligand-stimulated efficacy for total inositol phosphate stimulation. The hPACAP-R-SV2 showed the greatest efficacy for stimulating phospholipase C that was approximately seven-fold greater than the hPACAP-R-SV1, twofold greater than the hPACAP-R-Null, and 1.5-fold greater than the hPACAP-R-SV-3 splice variants. To determine whether the splice variants also differ in their ability to stimulate immediate early gene expression, c-fos and c-myc transcripts were assayed by Northern blot and quantified by densitometry. PACAP-38 increased c-fos and c-myc expression for all four of the receptor splice variants that paralleled the efficacy for PLC stimulation, with the the SV-2 splice variant showing the greatest stimulation. These results show that the hPACAP-R-SV2 exhibits enhanced efficacy for coupling to both PLC and activation of the protooncogenes, c-fos and c-myc suggesting a novel and potentially important mechanism for differentially activating signal transduction pathways that influence cellular growth and differentiation.
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Affiliation(s)
- J R Pisegna
- Digestive Diseases Branch, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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36
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Pisegna JR, Wank SA. Cloning and characterization of the signal transduction of four splice variants of the human pituitary adenylate cyclase activating polypeptide receptor. Evidence for dual coupling to adenylate cyclase and phospholipase C. J Biol Chem 1996; 271:17267-74. [PMID: 8663363 PMCID: PMC6721843 DOI: 10.1074/jbc.271.29.17267] [Citation(s) in RCA: 161] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Alternative splicing of two exons of the rat pituitary adenylate cyclase activating polypeptide (PACAP) receptor gene generates four major splice variants that are differentially expressed in specific tissues and variably coupled to intracellular second messengers. To evaluate the potential implications of these findings in human physiology, the human PACAP receptor gene was cloned. Alternative splicing about two exons of the gene allowed for four major splice variants that were subsequently identified on cDNA cloning. Each of the four splice variant cDNAs (null, SV-1, SV-2, and SV-3) was stably expressed in NIH/3T3 cells at similar receptor densities. For each splice variant, PACAP (both PACAP-38 and PACAP-27) had similar affinity and potency for stimulating either adenylate cyclase or phospholipase C. However, each receptor splice variant differed in their ligand-stimulated maximal response (efficacy) for total inositol phosphate accumulation with the SV-2 showing the greatest efficacy, followed by the null, SV-1, and SV-3 splice variants. Therefore, unlike the rat, PACAP binds and stimulates signal transduction with nearly equal affinity and potency for each of the receptor splice variants although with varying efficacy for the stimulation of phospholipase C. These results suggest a novel and potentially important mechanism for a single hormone to not only couple to dual signal transduction cascades but also elicit tissue-specific differential activation of phospholipase C in humans.
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Affiliation(s)
- J R Pisegna
- Digestive Diseases Branch, National Institute of Diabetes, and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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37
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Silvente-Poirot S, Wank SA. A segment of five amino acids in the second extracellular loop of the cholecystokinin-B receptor is essential for selectivity of the peptide agonist gastrin. J Biol Chem 1996; 271:14698-706. [PMID: 8663021 DOI: 10.1074/jbc.271.25.14698] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The two known receptors mediating the actions of cholecystokinin (CCK) and gastrin, CCK type A (CCKAR) and CCK type B (CCKBR) receptors, are G protein-coupled receptors having approximately 50% amino acid homology. Both the CCKAR and CCKBR have high affinity for sulfated CCK peptides, while only the CCKBR has high affinity for gastrin peptides. To determine the structural basis for the selectivity of the CCKBR for gastrin, we first constructed a series of CCKB/AR chimeras in which restriction endonuclease-defined segments of the CCKBR were replaced with the corresponding segments of the CCKAR. Chimeras transiently expressed in COS-1 cells were screened for the selective loss of gastrin affinity according to the displacement of 125I-labeled Bolton-Hunter-CCK-8 binding by gastrin-17-I and CCK-8. The sequence spanning from transmembrane domain III (TM III) to TM V was the only segment that resulted in the selective loss of gastrin affinity. This segment could account for 100 of the expected 300-fold lower affinity of gastrin-17-I observed for the control CCKAR compared to the control CCKBR. Using site-directed mutagenesis in this segment of the CCKBR, we identified a sequence of 5 amino acids in the second extracellular loop responsible for this 100-fold selective loss in gastrin affinity. 125I-labeled Bolton-Hunter-CCK-8 binding displacement by L365,260 (a CCKBR selective antagonist) was unaffected by the changes in these 5 amino acids. These results present for the first time the identification of the amino acid sequence of the CCKBR conferring the majority of the selectivity for gastrin.
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Affiliation(s)
- S Silvente-Poirot
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892-1804, USA
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38
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Abstract
The cholecystokinin (CCK) and gastrin families of peptides act as hormones and neuropeptides on central and peripheral CCK receptors to mediate secretion and motility in the gastrointestinal (GI) tract in the physiological response to a normal meal. CCK and its receptors are also widely distributed in the central nervous system (CNS) and contribute to the regulation of satiety, anxiety, analgesia, and dopamine-mediated behavior. Although the wide distribution, myriad number of functions, and reported pharmacological heterogeneity of CCK receptors would suggest a large number of receptor subtypes, the application of modern molecular biological techniques has identified two CCK receptors, CCK-A receptor (CCK-AR) and CCK-B receptor (CCK-BR), that mediate the actions of CCK and gastrin; gastrin receptors have been found to be identical to CCK-BR. CCK-AR, found predominantly in the GI system and select areas of the CNS, have high affinity for CCK and the nonpeptide antagonist L-364,718, whereas CCK-BR, found predominantly in the CNS and select areas of the GI system, have high affinity for CCK and gastrin and the nonpeptide antagonist L-365,260. Both CCK-AR and CCK-BR are highly conserved between species, although there is some tissue-specific variation in expression. Recombinant receptor expression faithfully reproduces the native receptor pharmacology and signal transduction pathways, allowing direct comparisons of receptor function between species as well as serving as a convenient source of receptor. Our present knowledge of the chromosomal localization, receptor gene structure, and primary sequence will allow further studies in disease association, receptor regulation, and structure-function analysis.
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Zia F, Fagarasan M, Bitar K, Coy DH, Pisegna JR, Wank SA, Moody TW. Pituitary adenylate cyclase activating peptide receptors regulate the growth of non-small cell lung cancer cells. Cancer Res 1995; 55:4886-91. [PMID: 7585525 PMCID: PMC6719695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have identified pituitary adenylate cyclase activating peptide (PACAP) receptors on small cell lung cancer cell line NCI-N417 in a previous study. In this study, the role of PACAP in the growth and signal transduction of non-small cell lung cancer cells was investigated. Northern blot analysis with a full-length human PACAP receptor cDNA probe revealed a major 7.5-kb hybridizing transcript when total RNA extracted from NCI-H838 cells was used. PACAP bound with high affinity (Kd = 1 nM) to a single class of sites (Bmax = 14,000/cell) when NCI-H838 cells were used. Specific 125I-labeled PACAP binding was inhibited with high affinity by PACAP-27 and PACAP-38, with moderate affinity by PACAP(6-38), and with low affinity by vasoactive intestinal polypeptide, PACAP(28-38), and PACAP(16-38). PACAP-27 elevated cAMP in a dose-dependent manner, and the increase in cAMP caused by PACAP was reversed by PACAP(6-38). PACAP-27, but not vasoactive intestinal polypeptide, elevated cytosolic Ca2+ in individual NCI-H838 cells. PACAP-27 stimulated arachidonic acid release, and the increase caused by PACAP was reversed by PACAP(6-38). PACAP-27 stimulated colony formation in NCI-H838 cells, whereas the PACAP antagonist PACAP(6-38) reduced colony formation in the absence or presence of exogenous PACAP-27. In nude mice bearing NCI-H838 xenografts, PACAP(6-38) slowed tumor growth significantly. These data suggest that biologically active type 1 PACAP receptors are present on human non-small cell lung cancer cells, which exhibit dual signal transduction pathways and regulate cell proliferation.
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MESH Headings
- Animals
- Antineoplastic Agents/pharmacology
- Arachidonic Acid/metabolism
- Binding Sites
- Blotting, Northern
- Calcium/metabolism
- Carcinoma, Non-Small-Cell Lung/drug therapy
- Carcinoma, Non-Small-Cell Lung/metabolism
- Carcinoma, Non-Small-Cell Lung/pathology
- Cell Division/physiology
- Cyclic AMP/metabolism
- Female
- Humans
- Intracellular Fluid/metabolism
- Iodine Radioisotopes
- Lung Neoplasms/drug therapy
- Lung Neoplasms/metabolism
- Lung Neoplasms/pathology
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Nude
- Neoplasm Transplantation
- Neuropeptides/metabolism
- Neuropeptides/pharmacology
- Pituitary Adenylate Cyclase-Activating Polypeptide
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I
- Receptors, Pituitary Hormone/metabolism
- Receptors, Pituitary Hormone/physiology
- Sensitivity and Specificity
- Transplantation, Heterologous
- Tumor Cells, Cultured
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Affiliation(s)
- F Zia
- Department of Microbiology, George Washington University Medical Center, Washington, District of Columbia 20037, USA
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40
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Czerwinski G, Wank SA, Tarasova NI, Hudson EA, Resau JH, Michejda CJ. Synthesis and properties of three fluorescent derivatives of gastrin. ACTA ACUST UNITED AC 1995. [DOI: 10.1007/bf00127270] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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41
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Huang SC, Fortune KP, Wank SA, Kopin AS, Gardner JD. Multiple affinity states of different cholecystokinin receptors. J Biol Chem 1994; 269:26121-6. [PMID: 7929324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We transfected COS cells with cDNA for rat cholecystokinin-A (CCK-A) and different CCK-B receptors and measured binding of 125I-CCK-8, [3H]L-364,718 and [3H]L-365,260 to characterize the different affinity states for each type of CCK receptor. Rat CCK-A and CCK-B receptors, canine CCK-B receptors and canine mutant CCK-B (M-CCK-B) receptors in which the leucine in position 355 was replaced by valine each existed in three different affinity states for CCK-8, high affinity, low affinity, and very low affinity. In rat CCK-A and probably CCK-B receptors, most were in the very low affinity state, whereas with canine CCK-B and M-CCK-B receptors, most were in the low affinity state. Studies with CCK receptor agonists, CCK-8, gastrin, and CCK-JMV-180, in conjunction with CCK receptor antagonists, L-364,718 and L-365,260, showed a different pattern of affinities for these ligands at the different CCK receptors. Thus, each transfected CCK receptor can exist in three different affinity states for CCK-8 and has a characteristic pattern of interaction with different ligands. This ability to exist in multiple affinity states is an intrinsic property of the CCK receptor molecule itself.
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Affiliation(s)
- S C Huang
- Department of Internal Medicine, St. Louis University Health Sciences Center, Missouri 63104
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42
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Pandya PK, Huang SC, Talkad VD, Wank SA, Gardner JD. Biochemical regulation of the three different states of the cholecystokinin (CCK) receptor in pancreatic acini. Biochim Biophys Acta 1994; 1224:117-26. [PMID: 7948036 DOI: 10.1016/0167-4889(94)90119-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We used rat pancreatic acini and measured binding of [125I]CCK-8 and [3H]L-364,718 to the three different states of the CCK receptor to examine potential biochemical regulation of ligand binding for each receptor state. Binding of [125I]CCK-8 to the high affinity state of the receptor was measured as carbachol-inhibitable binding of [125I]CCK-8, whereas binding of [125I]CCK-8 to the low affinity state was measured as carbachol-resistant binding of [125I]CCK-8. Interaction of CCK-8 with the very low affinity state of the CCK receptor was measured as CCK-8-inhibitable binding of [3H]L-364,718. [125I]CCK-8 that was bound to the high affinity state dissociated slowly at a rate of 0.20%/min and this dissociation was not altered by 30 mM NaF. Dissociation of [125I]CCK-8 bound to the low affinity state was biphasic--22% of the bound radioactivity dissociated completely within 3 min and the remaining 78% dissociated slowly at a rate of 0.19%/min. Dissociation of [125I]CCK-8 from the low affinity state was not altered by 30 mM NaF. The pattern of dissociation of bound [125I]CCK-8 from the pancreatic CCK receptor expressed in COS cells was also biphasic and closely resembled that observed in pancreatic acini. CCK-8 that was bound to the very low affinity state dissociated completely during a 20-min period of washing and resuspension of acini that had been first incubated with CCK-8. We found extensive biochemical regulation of the different states of the CCK receptor in pancreatic acini. Bombesin, TPA, NaF, CCCP and trifluoperazine each altered binding of [125I]CCK-8 to the high affinity state and to the low affinity state, and except for bombesin each agent was more potent in affecting the high affinity state than the low affinity state. No agent tested affected the low affinity state but not the high affinity state. In contrast, a number of agents affected the high affinity state but not the low affinity state. These included receptor-mediated agonists (carbachol, secretin, VIP), 8Br-cAMP, NEM, agents that affect microtubules or microfilaments (cytochalasin B, vinblastine), calmodulin inhibitors (W-7, chlorpromazine) and genistein. Experiments with EGTA, A23187 and thapsigargin indicated that none of the three receptor states was influenced by intracellular or extracellular calcium. No agent tested altered the interaction of CCK-8 with the very low affinity state of the CCK receptor.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- P K Pandya
- Department of Internal Medicine, Saint Louis University Health Sciences Center, MO 63104
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43
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44
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Pisegna JR, de Weerth A, Huppi K, Wank SA. Molecular cloning, functional expression, and chromosomal localization of the human cholecystokinin type A receptor. Ann N Y Acad Sci 1994; 713:338-42. [PMID: 8185181 DOI: 10.1111/j.1749-6632.1994.tb44086.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The results presented here describe for the first time the molecular cloning of the human CCKA-R. Expression of the recombinant receptor shows the expected subtype pharmacology and coupling to phosphoinositide hydrolysis reported for the native human CCKA-R. This knowledge will enhance our understanding of its distribution, pharmacology, and structure and will improve our understanding of its physiological role in the gastrointestinal and nervous systems in humans. Ultimately, this should hasten the understanding and therapy of gastrointestinal and neuropsychiatric disorders.
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Affiliation(s)
- J R Pisegna
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
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45
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Abstract
A review of the literature encompassing numerous pharmacological, physiological, and biochemical studies indicates the presence of at least four CCK receptor types, CCKA, CCKB, gastrin, and CG-4 receptors. Multiple subtypes of the CCKAR have been postulated to account for the differences in pharmacology or affinity cross-linking of CCKARs between pancreas and gallbladder and the presence of high and low affinity CCKARs on pancreatic acini. Multiple subtypes of the CCKBR have been postulated to explain the differences in pharmacology and physiology between gastric and gallbladder smooth muscle CCKBRs. We recently cloned and functionally expressed both the CCKAR and the CCKBR from rat, guinea pig, and human. The CCKAR and CCKBR are 48% homologous and constitute a family of receptors within the guanine nucleotide-binding regulatory protein-coupled superfamily of receptors. Each receptor is highly conserved between species. A single cDNA encoding a single protein is present in both pancreas and gallbladder and can account for both high and low affinity CCKARs found on pancreatic acini when transfected into COS-7 cells. A single cDNA encoding a single CCKBR protein is present in both the central nervous system and the periphery including the gastrointestinal system. Therefore, the gastrin receptor is actually a CCKBR present on parietal cells. Genomic and cDNA library hybridization as well as Northern and Southern hybridization studies among rat, guinea pig, and human species identifies only two members of the CCK receptor family, CCKAR and CCKBR. Although these studies do not identify other closely related members of the CCK receptor family, they do not rule out the existence of other less closely related members. Furthermore, differences in tissue and species-specific posttranslational processing, receptor coupling, and associated membrane protein and lipid heterogeneity may be among some of the other factors that may account for the phenotypic expression of more receptor subtypes than molecular studies would predict.
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Affiliation(s)
- S A Wank
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
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46
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Jensen RT, Qian JM, Lin JT, Mantey SA, Pisegna JR, Wank SA. Distinguishing multiple CCK receptor subtypes. Studies with guinea pig chief cells and transfected human CCK receptors. Ann N Y Acad Sci 1994; 713:88-106. [PMID: 8185217 PMCID: PMC6736542 DOI: 10.1111/j.1749-6632.1994.tb44055.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- R T Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
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47
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Nilsson O, Kölby L, Wängberg B, Wank SA, Ahlman H. Expression of CCK-A and CCK-B/gastrin receptors in enterochromaffin-like cell carcinoids of Mastomys natalensis. Ann N Y Acad Sci 1994; 713:435-8. [PMID: 7910444 DOI: 10.1111/j.1749-6632.1994.tb44119.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- O Nilsson
- Department of Pathology, Sahlgrenska Hospital, Göteborg, Sweden
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48
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Talkad VD, Fortune KP, Pollo DA, Shah GN, Wank SA, Gardner JD. Direct demonstration of three different states of the pancreatic cholecystokinin receptor. Proc Natl Acad Sci U S A 1994; 91:1868-72. [PMID: 8127897 PMCID: PMC43265 DOI: 10.1073/pnas.91.5.1868] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We used rat pancreatic acini as well as COS-7 cells transfected with the cloned pancreatic cholecystokinin (CCK) receptor and measured the abilities of CCK octapeptide (CCK-8) and L-364,718 (a CCK receptor antagonist) to inhibit binding of 125I-labeled CCK-8 (125I-CCK-8) and [3H]L-364,718. With pancreatic acini 125I-CCK-8 bound to two different states of the CCK receptor. The high-affinity state (1% of the receptors) had a Kd for CCK-8 of 985 pM and the low-affinity state (19% of the receptors) had a Kd for CCK-8 of 30 nM. [3H]L-364,718 bound to low-affinity receptors and to a previously unrecognized very-low-affinity state (80% of the receptors) having a Kd for CCK-8 of 13 microM. L-364,718 had the same affinity (Kd 3 nM) for each of the three different states of the CCK receptor. Similar measurements using transfected COS cells also identified three different states of the CCK receptor, with the very-low-affinity state being the most abundant. Thus, the ability of the CCK receptor to exist in three different states is an intrinsic property of the CCK receptor molecule itself.
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Affiliation(s)
- V D Talkad
- Department of Internal Medicine, Saint Louis University Medical Center, MO 63104
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De Weerth A, Pisegna JR, Wank SA. Guinea pig gallbladder and pancreas possess identical CCK-A receptor subtypes: receptor cloning and expression. Am J Physiol 1993; 265:G1116-21. [PMID: 7916580 PMCID: PMC6736548 DOI: 10.1152/ajpgi.1993.265.6.g1116] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cholecystokinin (CCK) receptors mediate pancreatic acinar secretion and gallbladder contraction. Pharmacological and functional studies in pancreas and gallbladder demonstrate a CCK-A receptor subtype in both tissues. However, some pharmacological studies and affinity cross-linking studies of CCK receptors on pancreatic acini and gallbladder suggest that these two tissues possess two different subtypes of the CCK-A receptor. We cloned these receptors in guinea pig using a cDNA clone of the CCK-A receptor from rat pancreas. The guinea pig gallbladder CCK-A receptor was cloned by hybridization screening of a gallbladder cDNA library using a cDNA probe from the rat CCK-A receptor coding region. The guinea pig pancreas CCK-A receptor cDNA was cloned via the polymerase chain reaction using primers corresponding to the guinea pig gallbladder CCK-A receptor 5'- and 3'-noncoding regions. CCK-A receptor clones from guinea pig pancreas and gallbladder had identical nucleotide sequences, which were 80% homologous to the rat CCK-A receptor cDNA sequence. The deduced amino acid sequence from guinea pig CCK-A receptors was 89% homologous to the rat CCK-A receptor sequence. Dose-inhibition binding studies of transiently expressed receptors by CCK agonists and antagonists exhibited a CCK-A receptor pharmacologically similar to the rat CCK-A receptor. These studies indicate that the CCK-A receptors in guinea pig pancreas and gallbladder are identical and do not support previous proposals that they may represent different receptor subtypes.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Blotting, Northern
- Cell Line
- Cloning, Molecular
- DNA Primers
- DNA, Complementary/isolation & purification
- DNA, Complementary/metabolism
- Gallbladder/metabolism
- Gene Expression
- Gene Library
- Guinea Pigs
- Liver/metabolism
- Male
- Molecular Sequence Data
- Muscles/metabolism
- Organ Specificity
- Pancreas/metabolism
- Polymerase Chain Reaction
- RNA, Messenger/biosynthesis
- RNA, Messenger/isolation & purification
- RNA, Messenger/metabolism
- Rats
- Receptor, Cholecystokinin A
- Receptors, Cholecystokinin/biosynthesis
- Receptors, Cholecystokinin/metabolism
- Recombinant Proteins/biosynthesis
- Recombinant Proteins/metabolism
- Sequence Homology, Amino Acid
- Sincalide/analogs & derivatives
- Sincalide/metabolism
- Succinimides/metabolism
- Transfection
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Affiliation(s)
- A De Weerth
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
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50
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de Weerth A, Pisegna JR, Huppi K, Wank SA. Molecular cloning, functional expression and chromosomal localization of the human cholecystokinin type A receptor. Biochem Biophys Res Commun 1993; 194:811-8. [PMID: 8343165 DOI: 10.1006/bbrc.1993.1894] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The cholecystokinin (CCK) family of peptides and receptors are present throughout the brain and gastrointestinal tract and can be pharmacologically subdivided into two subtypes: CCKA and CCKB. Little is known about the localization, pharmacology and function of CCKA receptors (CCKAR) in humans. We used the rat CCKAR cDNA to isolate the human CCK receptor cDNA homologue from human gallbladder which encodes a unique 428 amino acid protein having > 90% homology to the rat and guinea pig CCKAR. Expression of the recombinant CCKAR in COS-7 cells displayed a pharmacological profile characteristic of a CCKAR subtype and mediated agonist stimulated increase in total inositol phosphates. Northern hybridization identified a transcript measuring 6 Kb. The human CCKAR gene maps to chromosome 4. These results describe for the first time the molecular cloning, expression and chromosomal localization of the human CCKA receptor.
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Affiliation(s)
- A de Weerth
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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