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Schüß C, Behr V, Beck-Sickinger AG. Illuminating the neuropeptide Y 4 receptor and its ligand pancreatic polypeptide from a structural, functional, and therapeutic perspective. Neuropeptides 2024; 105:102416. [PMID: 38430725 DOI: 10.1016/j.npep.2024.102416] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/12/2024] [Accepted: 02/20/2024] [Indexed: 03/05/2024]
Abstract
The neuropeptide Y4 receptor (Y4R), a rhodopsin-like G protein-coupled receptor (GPCR) and the hormone pancreatic polypeptide (PP) are members of the neuropeptide Y family consisting of four receptors (Y1R, Y2R, Y4R, Y5R) and three highly homologous peptide ligands (neuropeptide Y, peptide YY, PP). In this family, the Y4R is of particular interest as it is the only subtype with high affinity to PP over NPY. The Y4R, as a mediator of PP signaling, has a pivotal role in appetite regulation and energy homeostasis, offering potential avenues for the treatment of metabolic disorders such as obesity. PP as anorexigenic peptide is released postprandial from the pancreas in response to food intake, induces satiety signals and contributes to hamper excessive food intake. Moreover, this system was also described to be associated with different types of cancer: overexpression of Y4R have been found in human adenocarcinoma cells, while elevated levels of PP are related to the development of pancreatic endocrine tumors. The pharmacological relevance of the Y4R advanced the search for potent and selective ligands for this receptor subtype, which will be significantly progressed through the elucidation of the active state PP-Y4R cryo-EM structure. This review summarizes the development of novel PP-derived ligands, like Obinepitide as dual Y2R/Y4R agonist in clinical trials or UR-AK86c as small hexapeptide agonist with picomolar affinity, as well as the first allosteric modulators that selectively target the Y4R, e.g. VU0506013 as potent Y4R positive allosteric modulator or (S)-VU0637120 as allosteric antagonist. Here, we provide valuable insights into the complex physiological functions of the Y4R and PP and the pharmacological relevance of the system in appetite regulation to open up new avenues for the development of tool compounds for targeted therapies with potential applications in metabolic disorders.
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Affiliation(s)
- Corinna Schüß
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Germany.
| | - Victoria Behr
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Germany
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Fukaishi T, Nakagawa Y, Fukunaka A, Sato T, Hara A, Nakao K, Saito M, Kohno K, Miyatsuka T, Tamaki M, Matsuhisa M, Matsuoka TA, Yamada T, Watada H, Fujitani Y. Characterisation of Ppy-lineage cells clarifies the functional heterogeneity of pancreatic beta cells in mice. Diabetologia 2021; 64:2803-2816. [PMID: 34498099 PMCID: PMC8563568 DOI: 10.1007/s00125-021-05560-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 06/28/2021] [Indexed: 12/16/2022]
Abstract
AIMS/HYPOTHESIS Pancreatic polypeptide (PP) cells, which secrete PP (encoded by the Ppy gene), are a minor population of pancreatic endocrine cells. Although it has been reported that the loss of beta cell identity might be associated with beta-to-PP cell-fate conversion, at present, little is known regarding the characteristics of Ppy-lineage cells. METHODS We used Ppy-Cre driver mice and a PP-specific monoclonal antibody to investigate the association between Ppy-lineage cells and beta cells. The molecular profiles of endocrine cells were investigated by single-cell transcriptome analysis and the glucose responsiveness of beta cells was assessed by Ca2+ imaging. Diabetic conditions were experimentally induced in mice by either streptozotocin or diphtheria toxin. RESULTS Ppy-lineage cells were found to contribute to the four major types of endocrine cells, including beta cells. Ppy-lineage beta cells are a minor subpopulation, accounting for 12-15% of total beta cells, and are mostly (81.2%) localised at the islet periphery. Unbiased single-cell analysis with a Ppy-lineage tracer demonstrated that beta cells are composed of seven clusters, which are categorised into two groups (i.e. Ppy-lineage and non-Ppy-lineage beta cells). These subpopulations of beta cells demonstrated distinct characteristics regarding their functionality and gene expression profiles. Ppy-lineage beta cells had a reduced glucose-stimulated Ca2+ signalling response and were increased in number in experimental diabetes models. CONCLUSIONS/INTERPRETATION Our results indicate that an unexpected degree of beta cell heterogeneity is defined by Ppy gene activation, providing valuable insight into the homeostatic regulation of pancreatic islets and future therapeutic strategies against diabetes. DATA AVAILABILITY The single-cell RNA sequence (scRNA-seq) analysis datasets generated in this study have been deposited in the Gene Expression Omnibus (GEO) under the accession number GSE166164 ( www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE166164 ).
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Affiliation(s)
- Takahiro Fukaishi
- Laboratory of Developmental Biology & Metabolism, Institute for Molecular and Cellular Regulation, Gunma University, Gunma, Japan
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yuko Nakagawa
- Laboratory of Developmental Biology & Metabolism, Institute for Molecular and Cellular Regulation, Gunma University, Gunma, Japan
| | - Ayako Fukunaka
- Laboratory of Developmental Biology & Metabolism, Institute for Molecular and Cellular Regulation, Gunma University, Gunma, Japan
| | - Takashi Sato
- Laboratory of Developmental Biology & Metabolism, Institute for Molecular and Cellular Regulation, Gunma University, Gunma, Japan
| | - Akemi Hara
- Department of Metabolism & Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
- Center for Therapeutic Innovations in Diabetes, Juntendo University Graduate School of Medicine, Tokyo, Japan
- Department of Physiology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Keiko Nakao
- Department of Physiology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Michiko Saito
- Institute for Research Initiatives, Nara Institute of Science and Technology (NAIST), Nara, Japan
- Bio-science Research Center, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Kenji Kohno
- Institute for Research Initiatives, Nara Institute of Science and Technology (NAIST), Nara, Japan
| | - Takeshi Miyatsuka
- Department of Metabolism & Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
- Center for Therapeutic Innovations in Diabetes, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Motoyuki Tamaki
- Diabetes Therapeutics and Research Center, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Munehide Matsuhisa
- Diabetes Therapeutics and Research Center, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Taka-Aki Matsuoka
- The First Department of Medicine, Wakayama Medical University, Wakayama, Japan
| | - Tetsuya Yamada
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hirotaka Watada
- Department of Metabolism & Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
- Center for Therapeutic Innovations in Diabetes, Juntendo University Graduate School of Medicine, Tokyo, Japan
- Center for Identification of Diabetic Therapeutic Targets, Juntendo University Graduate School of Medicine, Tokyo, Japan
- Sportology Center, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yoshio Fujitani
- Laboratory of Developmental Biology & Metabolism, Institute for Molecular and Cellular Regulation, Gunma University, Gunma, Japan.
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Buss C, Maranhão PA, de Souza MDGC, Bouskela E, Kraemer-Aguiar LG. Obesity blunts cephalic-phase microvascular responses to food. Physiol Behav 2020; 225:113087. [PMID: 32707159 DOI: 10.1016/j.physbeh.2020.113087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 07/09/2020] [Accepted: 07/17/2020] [Indexed: 11/22/2022]
Abstract
Neurally mediated anticipatory responses, also named cephalic-phase responses, and microcirculatory regulation are two important mechanisms to maintain metabolic homeostasis. Altered cephalic-phase responses in obesity and its metabolic consequences have been proposed. There is, however, a lack of studies focusing on in vivo assessment of the microcirculation during this phase in patients with obesity. In this randomized controlled trial, we selected patients with obesity and healthy subjects after clinical and laboratory assessments. Those with obesity were randomized into two groups: experimental (cephalic-phase microvascular response stimulation - CP group, n = 13) and controls (n = 14). Healthy subjects (n = 17) were also included to form a CP control group. Skin microvascular assessment was used as a model of systemic microcirculation. Resting functional capillary density (FCD) and peak FCD during post-occlusive reactive hyperemia (PORH) were measured by dorsal finger videocapillaroscopy and expressed mainly capillary recruitment capacity. Resting red blood cell velocity (RBCV), peak RBCV during PORH (RBCVmax), and time taken to reach RBCVmax (TRBCVmax) were assessed by dynamic nailfold videocapillaroscopy and expressed the microhemodynamics. Patients with obesity (with or without stimulus) failed to show an increase on FCD during PORH post-stimulus (p = 0.221 and p = 0.307, respectively) depicting lack of capillary recruitment. In contrast, healthy subjects presented an increase in this microvascular outcome (p = 0.004). Changes in all variables of microhemodynamics occurred in both CP groups (healthy and those with obesity). During CP, we originally demonstrated an absence of capillary recruitment in subjects with obesity. These findings might contribute to the literature of microvascular impairment and metabolic conditions.
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Park JM, Chiu CF, Chen SC, Lee WJ, Chen CY. Changes in post-oral glucose challenge pancreatic polypeptide hormone levels following metabolic surgery: A comparison of gastric bypass and sleeve gastrectomy. Neuropeptides 2020; 81:102032. [PMID: 32169256 DOI: 10.1016/j.npep.2020.102032] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/19/2020] [Accepted: 02/23/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Pancreatic polypeptide (PP) hormone is a 36-amino-acid peptide released from the pancreas, the serum levels of which have been shown to rise upon food intake. The underlying mechanism for metabolic surgery in the treatment of patients with type 2 diabetes mellitus (T2DM) remains intriguing. We compared post-oral glucose challenge PP levels between patients undergoing laparoscopic gastric bypass (GB) and sleeve gastrectomy (SG) at 1 year after surgery. METHODS This hospital-based, prospective study followed up a total of 12 laparoscopic GB and 12 laparoscopic SG patients and evaluated their glucose homeostasis. One year after metabolic surgery, 75-g oral glucose tolerance tests (OGTTs) were performed in the patients in the GB and SG groups and the blood levels of PP were evaluated. RESULTS The laparoscopic GB group had stable serum PP levels within 120 min after OGTT; however, the levels were significantly higher in the laparoscopic SG group at 30 min after OGTT. The patients with complete T2DM remission did not exhibit significantly different PP levels at fasting and post-OGTT than those in patients without remission after GB. Similarly, after SG, patients with T2DM remission did not show significantly different PP levels at fasting and post-OGTT than those in patients without T2DM remission. CONCLUSIONS No significant difference was found in plasma PP levels after OGTT in T2DM patients that received either GB or SG, or in T2DM remitters or non-remitters 1 year after metabolic surgery.
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Affiliation(s)
- Ji Min Park
- School of Nutrition and Health Sciences, College of Nutrition, Taipei Medical University, Taipei, Taiwan; Graduate Institute of Metabolism and Obesity Sciences, Taipei Medical University, Taipei, Taiwan
| | - Ching-Feng Chiu
- Graduate Institute of Metabolism and Obesity Sciences, Taipei Medical University, Taipei, Taiwan; Nutrition Research Center, Taipei Medical University Hospital, Taipei, Taiwan
| | - Shu-Chun Chen
- Department of Nursing, Chang-Gung Institute of Technology, Taoyuan, Taiwan
| | - Wei-Jei Lee
- Department of Surgery, Min-Sheng General Hospital, Taoyuan, Taiwan; Taiwan Society for Metabolic and Bariatric Surgery, Taipei, Taiwan
| | - Chih-Yen Chen
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Bariatric and Metabolic Surgery Center, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine and Institute of Emergency and Critical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan; Taiwan Association for the Study of Small Intestinal Diseases, Guishan, Taiwan; Chinese Taipei Society for the Study of Obesity, Taipei, Taiwan.
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Dai Y, Kurosawa K, Ren K, Miwa Y, Sato I, Liu T, Lu X, Yi SQ. Morphogenesis of the ventral pancreas anlagen is influenced by the SMA branching pattern. Ann Anat 2020; 229:151481. [PMID: 32068017 DOI: 10.1016/j.aanat.2020.151481] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 12/08/2019] [Accepted: 01/25/2020] [Indexed: 11/29/2022]
Abstract
Developmentally, the uncinate process of the pancreas is derived from the ventral pancreatic anlagen, supplied by the superior mesenteric artery (SMA), and contains pancreatic polypeptide (PP)-rich islets of Langerhans. In contrast, the other parts of the pancreas originate from the dorsal anlagen supplied by the celiac system and contain PP-poor islets. This study was performed to investigate whether morphogenesis of the ventral pancreas anlagen is associated with the pattern of SMA branching. SMA branches to the pancreatic body were dissected in 44 cadavers. The cadavers were divided into two groups: the SMA group in which the SMA gave off branches to the pancreatic body and the General group in which it did not. In the SMA group, the ratio of the diameter of the SMA branch supplying the pancreatic body (SMA branch) to that of the SMA itself was calculated. After dissection was completed, tissues were collected from all pancreatic specimens for HE staining and for immunohistochemistry with PP and insulin antibodies. There were 25 cadavers in the General group and 19 in the SMA group. In 10/19 cadavers from the SMA group, PP-rich islets were confirmed in the pancreatic body. The SMA branch diameter ratio was significantly smaller in the SMA group cadavers with PP-poor islets (n = 9) than in cadavers with PP-rich islets (n = 10) (P < 0.001). These findings suggest a relation between the SMA branching pattern and the distribution of PP cells.
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Affiliation(s)
- Yidan Dai
- Department of Frontier Health Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Kazuhiro Kurosawa
- Department of Frontier Health Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Ke Ren
- Project Division for Healthcare Innovation, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Yoko Miwa
- Department of Anatomy, School of Life Dentistry at Tokyo, Nippon Dental University, Tokyo, Japan
| | - Iwao Sato
- Department of Frontier Health Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Tao Liu
- Department of Gastrointestinal Surgery, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoming Lu
- Department of Gastrointestinal Surgery, Huazhong University of Science and Technology, Wuhan, China
| | - Shuang-Qin Yi
- Department of Frontier Health Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan.
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Abstract
Gangliocytic paraganglioma (GP) is rare neuroendocrine tumor (NET) with a good prognosis that commonly arising from duodenum. Although the tumor is characterized by its unique triphasic cells (epithelioid, spindle, and ganglion-like cells), the proportions of these three tumor cells vary widely from case to case, and occasionally, morphological and immunohistochemical similarities are found between GP and NET G1 (carcinoid tumors). Further, GP accounts for a substantial number of duodenal NETs. Therefore, GP continues to be misdiagnosed, most often as NET G1. However, GP has a better prognosis than NET G1, and it is important to differentiate GP from NET G1. In this article, I wish to provide up-to-date clinicopathological information to help oncologists gain better insight into the diagnosis and clinical management of this tumor.
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Affiliation(s)
- Yoichiro Okubo
- Department of Pathology, Kanagawa Cancer Center, Yokohama, Kanagawa 241-8515, Japan
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Abstract
Sterically stabilized micelle (SSM) is a self-assembled nanoparticle ideal for the delivery of therapeutic peptides. The PEGylated phospholipid forming the particle, DSPE-PEG2000, is a safe, biocompatible, and biodegradable ingredient already approved for human use in the marketed product Doxil®. SSM can overcome formulation difficulties such as instability associated with peptide drugs, enabling their development for clinical application. The key advantage of this lipid-based nanocarrier is its simple preparation even at large scales, which allows easy transition to the clinics and the pharmaceutical market. In this chapter, we describe methods for preparation and characterization of peptides self-associated with SSM (peptide-SSM). We also discuss approaches to evaluate the biological activity of the peptide nanomedicines in vitro and in vivo.
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Affiliation(s)
- Karina Esparza
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Dulari Jayawardena
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Hayat Onyuksel
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL, USA.
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Yolsuriyanwong K, Marcotte E, Venu M, Chand B. Impact of vagus nerve integrity testing on surgical management in patients with previous operations with potential risk of vagal injury. Surg Endosc 2019; 33:2620-8. [PMID: 30361970 DOI: 10.1007/s00464-018-6562-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 10/21/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND Thoracic and foregut operations can cause vagal nerve injury resulting in delayed gastric emptying or gastroparesis. However, the cause of gastroparesis in these patients is not always from a vagal injury. We hypothesize that vagal nerve integrity (VNI) testing may better define who has vagal nerve dysfunction. This information may change subsequent operations. The aim of this study was to evaluate the impact of VNI testing in patients with prior thoracic or gastric surgery. METHODS From January 2014 to December 2017, patients who had previous operations with the potential risk of vagal injury and had VNI testing were reviewed. Excluded patients were those with no plan for a second operation or the second operation was only for gastroparesis. The main outcome was the percentage of operations altered due to the results of VNI testing. RESULTS Twelve patients (eight females) were included. Ages ranged from 37 to 77 years. VNI results were compatible with vagal injury in eight patients (67%). VNI test results altered subsequent operative plans in 41.7% (5/12). Pyloroplasty was done in addition to fundoplication in two patients. Plans for hiatal hernia repair with or without redo-fundoplication in three patients were changed by an additional pyloroplasty in one patient and partial gastrectomy with Roux-en-Y reconstruction in two patients. All patients who had secondary surgery had resolution of symptoms and improvement in objective testing. CONCLUSION The addition of VNI testing in patients with a previous potential risk of vagal nerve injury may help the surgeon select the appropriate secondary operation.
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Xiao CW, Faddoul C, Wood C. Dietary L-lysine supplementation altered the content of pancreatic polypeptide, enzymes involved in glutamine metabolism, and β-actin in rats. Amino Acids 2018; 50:1729-37. [PMID: 30191331 DOI: 10.1007/s00726-018-2648-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 08/29/2018] [Indexed: 10/28/2022]
Abstract
This study investigated the effects of Lys supplementation on serum pancreatic polypeptide (PP), glutamine (Gln) levels and the expression of PP, Gln synthetase (GlnS), glutaminase (Gls) and β-actin in different tissues such as pancreas, skeletal muscle, liver and kidney in rats. Male Sprague-Dawley rats were fed diets containing 7% casein supplemented with either 0% (Control), 1%, 1.5%, 3% Lys or 3% Lys with 1.5% Arg for a week. All rats were necropsied for collection of blood and tissues. Expression of PP, GlnS, Gls, and β-actin in tissues were determined using Western blotting. The results showed that the rats fed 3% supplemental Lys had significantly lower body weight gain (BWG) and food intake than the ≤ 1.5% Lys groups (P < 0.05). Supplementation with ≥ 1% Lys increased serum PP level (P < 0.05), but had no significant effect on pancreatic PP abundance (P > 0.05). GlnS expression was significantly lowered in skeletal muscle by ≥ 1.5% supplemental Lys compared to the Control (P < 0.05). The expression of Gls in the kidney was increased by the addition of 1.5% Arg to 3% Lys diet (P < 0.05). Liver β-actin significantly increased with both Lys and Arg supplementation and muscle β-actin significantly decreased (P < 0.05) with ≥ 1.5% supplemental Lys. Kidney β-actin significantly increased with Arg supplementation vs 3% Lys alone (P < 0.05). These results showed that dietary supplementation with ≥ 1.5% Lys significantly suppressed GlnS expression in the skeletal muscle, which may contribute to the decreased serum Gln levels, and that increased serum PP by Lys may be due to suppressed catabolism rather than increased synthesis of PP. Lys-induced PP may play a role in reducing food intake and BWG.
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Knudsen K, Hartmann B, Fedorova TD, Østergaard K, Krogh K, Møller N, Holst JJ, Borghammer P. Pancreatic Polypeptide in Parkinson's Disease: A Potential Marker of Parasympathetic Denervation. J Parkinsons Dis 2018; 7:645-652. [PMID: 28922171 DOI: 10.3233/jpd-171189] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND AND OBJECTIVES Parkinson's disease (PD) patients experience several non-motor symptoms from the gastrointestinal tract that may partly be caused by parasympathetic deficiency. The pancreas is densely innervated by the vagus nerve, which mediates early meal-induced secretion of pancreatic polypeptide (PP). Early secretion after sham feeding has been validated as a marker of vagal integrity. Thus, the aim was to evaluate the ratio of increased PP plasma levels after sham feeding in PD and correlate findings with gastrointestinal transit time (GITT). METHODS Twenty-five PD patients and 17 controls were included. PP, insulin, and blood glucose levels were measured before, during, and after sham feeding with white bread and chocolate spread. GITT was measured using radiopaque markers. Furthermore, faeces samples were analyzed for pancreatic elastase enzyme as a marker of exocrine pancreatic function. RESULTS PD patients showed significantly lower PP ratio levels after sham feeding, which was most pronounced at 10 minutes. No significant association was seen between attenuated PP response and GITT in PD patients. No between-group differences were seen in glucose or insulin levels over time, but PD patients showed generally lower insulin levels compared to controls. No difference was found in faeces pancreatic elastase. CONCLUSIONS Early-to-moderate stage PD patients demonstrated significantly decreased PP response after sham feeding suggestive of vagal denervation.
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Affiliation(s)
- Karoline Knudsen
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Denmark
| | - Bolette Hartmann
- NNF Center for Basic Metabolic Research and Department of Medical Sciences, University of Copenhagen, Denmark
| | - Tatyana D Fedorova
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Denmark
| | | | - Klaus Krogh
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Denmark
| | - Niels Møller
- Medical Research Laboratory, Department of Clinical Medicine, Health, Aarhus University, Denmark and Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Denmark
| | - Jens J Holst
- NNF Center for Basic Metabolic Research and Department of Medical Sciences, University of Copenhagen, Denmark
| | - Per Borghammer
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Denmark
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Cervantes A, Singh RG, Pendharkar SA, Bharmal SH, Petrov MS. Profile of Gut Hormones, Pancreatic Hormones and Pro-inflammatory Cytokines in New Zealand Maori. Gastroenterology Res 2018; 11:280-289. [PMID: 30116427 PMCID: PMC6089586 DOI: 10.14740/gr1042w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 05/28/2018] [Indexed: 12/11/2022] Open
Abstract
Background Maori, indigenous people of New Zealand, have at least two times higher prevalence of obesity and diabetes in comparison with the general population in the country. Gut and pancreatic hormone profile differences as well as pro-inflammatory milieu may contribute to this disparity. The aim was to investigate the differences in gut hormones, pancreatic hormones and pro-inflammatory cytokines between Maori and non-Maori individuals. Methods This was a cross-sectional study. Fasting blood samples were collected to measure cholecystokinin, ghrelin, gastric inhibitory peptide, glicentin, glucagon-like peptide-1 and -2, oxyntomodulin, secretin, amylin, C-peptide, glucagon, insulin, pancreatic polypeptide, somatostatin, interleukin-6, monocyte chemoattractant protein-1 and tumour necrosis factor-α. Binary logistic regression analysis was conducted in one unadjusted and four adjusted statistical models adjusting for patient-, metabolic- and pancreatitis-related factors. Results A total of 8 Maori and 85 non-Maori individuals were included. Circulating levels of ghrelin, pancreatic polypeptide and interleukin-6 levels were significantly higher in Maori (P = 0.005, P = 0.003 and P = 0.011, respectively) in both unadjusted and all the four adjusted analyses. Other signaling molecules did not show consistently significant associations with ethnicity. Conclusion Profile of gut hormones, pancreatic hormones and pro-inflammatory cytokines appears to differ between Maori and non-Maori individuals, independent of obesity, diabetes and other covariates. This may go some way to explain the increased propensity to obesity and diabetes in the Maori population.
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Affiliation(s)
- Aya Cervantes
- School of Medicine, University of Auckland, Auckland, New Zealand
| | - Ruma G Singh
- School of Medicine, University of Auckland, Auckland, New Zealand
| | | | - Sakina H Bharmal
- School of Medicine, University of Auckland, Auckland, New Zealand
| | - Maxim S Petrov
- School of Medicine, University of Auckland, Auckland, New Zealand
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Reid AMA, Wilson PW, Caughey SD, Dixon LM, D'Eath RB, Sandilands V, Boswell T, Dunn IC. Pancreatic PYY but not PPY expression is responsive to short-term nutritional state and the pancreas constitutes the major site of PYY mRNA expression in chickens. Gen Comp Endocrinol 2017; 252:226-235. [PMID: 28694054 PMCID: PMC5576917 DOI: 10.1016/j.ygcen.2017.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 06/23/2017] [Accepted: 07/05/2017] [Indexed: 12/17/2022]
Abstract
PP-fold peptides such as peptide YY (PYY) and pancreatic polypeptide (PPY) are known to play key roles in vertebrate energy homeostasis. Until recently, no gene sequence was available for avian PYY and therefore a gap in knowledge of regulation of its expression exists in avian species. Here we further evidence the mRNA sequence for chicken PYY and show that the pancreas is the major site of its mRNA expression, with a secondary peak of expression around the distal jejunum, in contrast to mammals where the large intestine is the major site of PYY expression. We also demonstrate that pancreatic PYY expression is responsive to short-term and long-term nutritional state, increasing within hours of feeding, in contrast to intestinal PYY which does not fluctuate to the same extent, and pancreatic PPY which appears to be primarily determined by long-term energy state. Both pancreatic PYY and PPY expression were found to exhibit ontogeny, being evenly distributed throughout the pancreas in young (2wk) chicks but having a decreasing splenic to duodenal gradient by adolescence (12wk).
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Affiliation(s)
- Angus M A Reid
- Roslin Institute, University of Edinburgh, EH25 9RG, Scotland, United Kingdom.
| | - Peter W Wilson
- Roslin Institute, University of Edinburgh, EH25 9RG, Scotland, United Kingdom
| | - Sarah D Caughey
- Roslin Institute, University of Edinburgh, EH25 9RG, Scotland, United Kingdom
| | - Laura M Dixon
- Scotland's Rural College (SRUC), Edinburgh EH9 3JG, Scotland, United Kingdom
| | - Rick B D'Eath
- Scotland's Rural College (SRUC), Edinburgh EH9 3JG, Scotland, United Kingdom
| | - Victoria Sandilands
- SRUC Avian Science Research Centre, Auchincruive, KA6 5HW, Scotland, United Kingdom
| | - Timothy Boswell
- School of Biology, Newcastle University, NE1 7RU, England, United Kingdom
| | - Ian C Dunn
- Roslin Institute, University of Edinburgh, EH25 9RG, Scotland, United Kingdom
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Krapfenbauer K. Identification of beta cell dysfunction at the pre-symptomatic stage of diabetes mellitus by novel analytical system: liquid biopsy measurements in femtograms. EPMA J 2017; 8:35-41. [PMID: 28228865 PMCID: PMC5306424 DOI: 10.1007/s13167-017-0079-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 12/28/2016] [Indexed: 11/22/2022]
Abstract
Background Diabetes mellitus is produced and progresses as a consequence of complex and gradual processes, in which a variety of alterations of the endocrine pancreas, are involved and which mainly result in beta cell failure. Those molecular alterations can be found in the bloodstream, which suggests that we could quantify specific biomarkers in plasma or serum by very sensitive methods before the onset diabetes mellitus is diagnosed. However, classical methods of protein analysis such as electrophoresis, Western blot, ELISA, and liquid chromatography are generally time-consuming, lab-intensive, and not sensitive enough to detect such alteration in a pre-symptomatic state of the disease. Method A very sensitive and novel analytical detection conjugate system by using the combination of polyfluorophor technology with protein microchip method was developed. Results This innovative system facilitates the use of a very sensitive microchip assays that measure selected biomarkers in a small sample volume (10 μL) with a much higher sensitivity (92%) compare to common immune assay systems. Further advances of the application of this technology combine the power of miniaturization and faster quantification (around 10 min). Conclusion The power of this technology offers great promise for point-of-care clinical testing and monitoring of specific biomarkers for diabetes in femtogram level in serum or plasma. In conclusion, the results indicate that the technical performance of this new technology is valid and that the assay is able to quantified PPY-specific antigens in plasma at femtogram levels which can be used for identification of beta cell dysfunction at the pre-symptomatic stage of diabetes mellitus.
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Affiliation(s)
- Kurt Krapfenbauer
- 0000 0000 9259 8492grid.22937.3dDepartment of Cranio-Maxillofacial and Oral Surgery, Medical University of Vienna, Waehringerguertel 18-20, A-1090 Vienna, Austria
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Khan D, Vasu S, Moffett RC, Irwin N, Flatt PR. Influence of neuropeptide Y and pancreatic polypeptide on islet function and beta-cell survival. Biochim Biophys Acta Gen Subj 2017; 1861:749-758. [PMID: 28069397 DOI: 10.1016/j.bbagen.2017.01.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/03/2017] [Accepted: 01/04/2017] [Indexed: 01/06/2023]
Abstract
BACKGROUND In the present study we assessed the impact of neuropeptide Y receptor (NPYR) modulators, neuropeptide Y (NPY) and pancreatic polypeptide (PP), on islet function and beta-cell survival. METHODS The effects of NPY and PP on beta-cell function were examined in BRIN BD11 and 1.1B4 beta-cells, as well as isolated mouse islets. Involvement of both peptides in pancreatic islet adaptations to streptozotocin and hydrocortisone, as well as effects on beta-cell proliferation and apoptosis was also evaluated. RESULTS Neither NPY nor PP affected in vivo glucose disposal or insulin secretion in mice. However, both peptides inhibited (p<0.05 to p<0.001) glucose stimulated insulin secretion from rat and human beta-cells. NPY exerted similar insulinostatic effects in isolated mouse islets. NPY and PP inhibited alanine-induced changes in BRIN BD11 cell membrane potential and (Ca2+)i. Streptozotocin treatment decreased and hydrocortisone treatment increased beta-cell mass in mice. In addition, streptozotocin, but not hydrocortisone, increased PP cell area. Streptozotocin also shifted the normal co-localisation of NPY with PP, towards more pronounced co-expression with somatostatin in delta-cells. Both streptozotocin and hydrocortisone increased pancreatic exocrine expression of NPY. More detailed in vitro investigations revealed that NPY, but not PP, augmented (p<0.01) BRIN BD11 beta-cell proliferation. In addition, both peptides exerted protective effects against streptozotocin-induced DNA damage in beta-cells. CONCLUSION These data emphasise the involvement of PP, and particularly NPY, in the regulation of beta-cell mass and function. GENERAL SIGNIFICANCE Modulation of PP and NPY signalling is suitable for further evaluation and possible clinical development for the treatment of diabetes.
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Affiliation(s)
- Dawood Khan
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - Srividya Vasu
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - R Charlotte Moffett
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - Nigel Irwin
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK.
| | - Peter R Flatt
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
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15
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Gao S, Zhang J, He C, Meng F, Bu G, Zhu G, Li J, Wang Y. Molecular characterization of neuropeptide Y (NPY) receptors (Y1, Y4 and Y6) and investigation of the tissue expression of their ligands (NPY, PYY and PP) in chickens. Gen Comp Endocrinol 2017; 240:46-60. [PMID: 27641685 DOI: 10.1016/j.ygcen.2016.09.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 08/05/2016] [Accepted: 09/14/2016] [Indexed: 01/06/2023]
Abstract
Neuropeptide Y (NPY) receptors and its ligands, NPY, peptide YY (PYY) and pancreatic polypeptide (PP), are suggested to regulate many physiological processes including food intake in birds. However, our knowledge regarding this avian NPY system remains rather limited. Here, we examined the tissue expression of NPY, PYY and PP and the gene structure, expression and signaling of three NPY receptors (cY1, cY4 and cY6) in chickens. The results showed that 1) NPY is widely expressed in chicken tissues with abundance noted in the hypothalamus via quantitative real-time PCR, whereas PYY is highly expressed in the pancreas, gastrointestinal tract and various brain regions, and PP is expressed almost exclusively in the pancreas; 2) cY1, cY4 and cY6 contain novel non-coding exon(s) at their 5'-UTR; 3) The wide tissue distribution of cY1 and cY4 and cY6 were detected in chickens by quantitative real-time PCR and their expression is controlled by the promoter near exon 1, which displays strong promoter activity in DF-1 cells as demonstrated by Dual-luciferase reporter assay; 4) Monitored by luciferase reporter assays, activation of cY1 and cY4 expressed in HEK293 cells by chicken NPY1-36, PYY1-37, and PP1-36 treatment inhibits cAMP/PKA and activates MAPK/ERK signaling pathways, while cY6-expressing cells show little response to peptide treatment, indicating that cY1 and cY4, and not cY6, can transmit signals in vitro. Taken together, our study offers novel information about the expression and functionality of cY1, cY4, cY6 and their ligands in birds, and helps to decipher their conserved roles in vertebrates.
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Affiliation(s)
- Shunyu Gao
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China; College of Chemistry and Life Sciences, Chuxiong Normal University, Chuxiong 675000, PR China
| | - Jiannan Zhang
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Chen He
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Fengyan Meng
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Guixian Bu
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Guoqiang Zhu
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Juan Li
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Yajun Wang
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China.
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Sørensen H, Thomsen JH, Meyer ASP, Terzic D, Hilsted L, Kjærgaard J, Goetze JP, Barbosa TC, Secher NH. Phenylephrine increases near-infrared spectroscopy determined muscle oxygenation in men. J Clin Monit Comput 2016; 31:1159-1166. [PMID: 27987104 DOI: 10.1007/s10877-016-9965-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 12/07/2016] [Indexed: 01/22/2023]
Abstract
Phenylephrine increases mean arterial pressure (MAP) by enhanced total peripheral resistance (TPR) but near-infrared spectroscopy (NIRS) determined muscle oxygenation (SmO2) increases. We addressed that apparent paradox during supine rest and head-up tilt (HUT). Variables were determined ± phenylephrine in males during supine rest (n = 17) and 40° HUT (n = 7). MAP, stroke volume (SV), heart rate (HR), and TPR were derived by Modelflow® and NIRS determined biceps SmO2 and (tibial) bone oxygenation (StibialO2). For ten subjects, cardiac filling and the diameter of the inferior caval vein (ICV collapsibility index: ((ICVexpiration - ICVinspiration)/ICVexpiration) × 100) were assessed by ultrasound. Pancreatic polypeptide (PP) and atrial natriuretic peptide (proANP) in plasma were determined by immunoassay. Brachial artery blood flow was assessed by ultrasound and skin oxygenation (SskinO2) monitored by white light spectroscopy. Phenylephrine increased MAP by 34% and TPR (62%; P < 0.001) during supine rest. The ICV collapsibility index decreased (24%; P < 0.001) indicating augmented cardiac preload although volume of the left atrium and ventricle did not change. SV increased (18%; P < 0.001) as HR decreased (24%; P < 0.001). ProANP increased by 9% (P = 0.002) with unaffected PP. Brachial artery blood flow tended to decrease while SskinO2 together with StibialO2 decreased by 11% (P = 0.026) and 20% (P < 0.001), respectively. Conversely, phenylephrine increased SmO2 (9%) and restored the HUT elicited decrease in SmO2 (by 19%) along with SV (P = 0.02). Phenylephrine reduces skin and bone oxygenation and tends to reduce arm blood flow, suggesting that the increase in SmO2 reflects veno-constriction with consequent centralization of the blood volume.
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Affiliation(s)
- H Sørensen
- Department of Anesthesia, The Copenhagen Muscle Research Centre, University of Copenhagen, Rigshospitalet 2043, Blegdamsvej 9, DK-2100, Copenhagen Ø, Denmark.
| | - J H Thomsen
- Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - A S P Meyer
- Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - D Terzic
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - L Hilsted
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - J Kjærgaard
- Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - J P Goetze
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - T C Barbosa
- Laboratory of Exercise Sciences, Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, Brazil
| | - N H Secher
- Department of Anesthesia, The Copenhagen Muscle Research Centre, University of Copenhagen, Rigshospitalet 2043, Blegdamsvej 9, DK-2100, Copenhagen Ø, Denmark
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Škrha J, Bušek P, Uhrová J, Hrabal P, Kmochová K, Laclav M, Bunganič B, Frič P. Lower plasma levels of glucose-dependent insulinotropic peptide (GIP) and pancreatic polypeptide (PP) in patients with ductal adenocarcinoma of the pancreas and their relation to the presence of impaired glucoregulation and weight loss. Pancreatology 2017; 17:89-94. [PMID: 28027898 DOI: 10.1016/j.pan.2016.12.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 11/14/2016] [Accepted: 12/15/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND The changes in gastrointestinal hormones associated with pancreatic ductal adenocarcinoma (PDAC) in patients with impaired glucoregulation have yet to be evaluated. The aim of this study was to determine plasma concentrations of selected gastrointestinal hormones in PDAC patients with and without diabetes and to compare them with levels found in Type 2 diabetic patients without cancer. METHODS In this study we examined plasma concentrations of glucose-dependent insulinotropic peptide (GIP), glucagon-like peptide 1 (GLP-1), pancreatic polypeptide (PP), peptide YY (PYY) and neuropeptide Y (NPY), and cytokines leptin and adiponectin in 94 patients with histologically confirmed PDAC. Thirty-nine patients with Type 2 diabetes without PDAC and 29 healthy individuals with no evidence of acute or chronic diseases were examined as controls. RESULTS Significantly lower plasma concentrations of GIP were found in PDAC patients with new-onset diabetes/prediabetes (n = 76), or in those with normal glucose regulation (n = 18), compared to patients with Type 2 diabetes without PDAC and controls (15.5 (3.7-64.5) or 6.5 (1.7-24.5) vs. 39.8 (15.1-104.7) and 28.8 (7.4-112.2) ng/L, p < 0.001); the same relationship was observed for PP (38.9 (10.2-147.9) or 28.1 (7.9-100.0) vs 89.1 (38.0-208.9) and 75.8 (30.1-190.6) ng/L, p < 0.01), respectively. The lowest levels of GIP and PP concentrations were found in PDAC patients with new-onset diabetes/prediabetes and weight loss > 2 kg (p < 0.001). CONCLUSIONS We conclude that GIP and PP plasma concentrations are lower in pancreatic cancer irrespective of the degree of glucose intolerance as compared to Type 2 diabetic patients and healthy controls. In new onset diabetes especially if associated with weight loss, these changes may represent a new clue for the diagnosis of PDAC.
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18
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Shuai H, Xu Y, Yu Q, Gylfe E, Tengholm A. Fluorescent protein vectors for pancreatic islet cell identification in live-cell imaging. Pflugers Arch 2016; 468:1765-77. [PMID: 27539300 PMCID: PMC5026721 DOI: 10.1007/s00424-016-1864-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 08/02/2016] [Accepted: 08/04/2016] [Indexed: 11/25/2022]
Abstract
The islets of Langerhans contain different types of endocrine cells, which are crucial for glucose homeostasis. β- and α-cells that release insulin and glucagon, respectively, are most abundant, whereas somatostatin-producing δ-cells and particularly pancreatic polypeptide-releasing PP-cells are more scarce. Studies of islet cell function are hampered by difficulties to identify the different cell types, especially in live-cell imaging experiments when immunostaining is unsuitable. The aim of the present study was to create a set of vectors for fluorescent protein expression with cell-type-specific promoters and evaluate their applicability in functional islet imaging. We constructed six adenoviral vectors for expression of red and green fluorescent proteins controlled by the insulin, preproglucagon, somatostatin, or pancreatic polypeptide promoters. After transduction of mouse and human islets or dispersed islet cells, a majority of the fluorescent cells also immunostained for the appropriate hormone. Recordings of the sub-plasma membrane Ca(2+) and cAMP concentrations with a fluorescent indicator and a protein biosensor, respectively, showed that labeled cells respond to glucose and other modulators of secretion and revealed a striking variability in Ca(2+) signaling among α-cells. The measurements allowed comparison of the phase relationship of Ca(2+) oscillations between different types of cells within intact islets. We conclude that the fluorescent protein vectors allow easy identification of specific islet cell types and can be used in live-cell imaging together with organic dyes and genetically encoded biosensors. This approach will facilitate studies of normal islet physiology and help to clarify molecular defects and disturbed cell interactions in diabetic islets.
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Affiliation(s)
- Hongyan Shuai
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-751 23, Uppsala, Sweden
| | - Yunjian Xu
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-751 23, Uppsala, Sweden
| | - Qian Yu
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-751 23, Uppsala, Sweden
| | - Erik Gylfe
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-751 23, Uppsala, Sweden
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-751 23, Uppsala, Sweden.
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19
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Ting CH, Chen YC, Liaw WJ, Lin HC, Chen CY. Peripheral injection of pancreatic polypeptide enhances colonic transit without eliciting anxiety or altering colonic secretion in rats. Neuropeptides 2016; 55:67-71. [PMID: 26601891 DOI: 10.1016/j.npep.2015.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 10/10/2015] [Accepted: 10/11/2015] [Indexed: 12/11/2022]
Abstract
Pancreatic polypeptide (PP) is a negative regulator of energy homeostasis that suppresses food intake and lowers body weight. Similar to other gastrointestinal-derived peptides, PP also modulates gastrointestinal motility and may be involved in the regulation of anxiety. Previous studies revealed that PP suppresses gastric emptying but increases colonic motility in mice. In our present study, we assessed the effect of PP on anxiety as well as colonic motility and secretory function. Intracerebroventricular and intravenous routes of PP were administered in conscious rats. Our results showed that intracerebroventricular administration of PP did not affect anxiety in the open field test. Intravenous injection of PP accelerated colonic transit, but did not significantly change fecal amount and fecal fluid composition. On the other hand, intracerebroventricular injection of PP did not alter colonic transit, fecal amount, or fluid composition. In conclusion, peripheral, but not central PP administration enhances colonic motility without eliciting anxiety or altering colonic secretion.
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Affiliation(s)
- Ching-Heng Ting
- Department of Medical Education, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Ying-Chieh Chen
- Division of Digestive Medicine, Taipei City Hospital Yangming Branch, Taipei, Taiwan
| | - Wen-Jinn Liaw
- Department of Anesthesiology, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan; Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan
| | - Han-Chieh Lin
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Chih-Yen Chen
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan.
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20
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Escobar H, Kushnir MM, Rockwood AL, Meikle AW. High Sensitivity Measurement of Pancreatic Polypeptide and Its Variant in Serum and Plasma by LC-MS/MS. Methods Mol Biol 2016; 1378:199-210. [PMID: 26602131 DOI: 10.1007/978-1-4939-3182-8_21] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Aliquots of serum or plasma samples are combined with stable isotope labeled internal standard. Pancreatic polypeptide (PP) and its truncated variant PP3-36 are enriched by incubation with anti-PP antibody conjugated to magnetic beads. Peptides are eluted from beads in acidic buffer and the samples analyzed using liquid chromatography coupled with tandem mass spectrometry. Instrumental analysis of PP and PP3-36 is performed using electrospray ionization ESI in positive ion mode and multiple reaction monitoring (MRM) acquisition.
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Affiliation(s)
- Hernando Escobar
- ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, 200 2nd St. SW, Salt Lake City, UT, 55905, USA
| | - Mark M Kushnir
- ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, 200 2nd St. SW, Salt Lake City, UT, 55905, USA
| | - Alan L Rockwood
- ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, 200 2nd St. SW, Salt Lake City, UT, 55905, USA. .,Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA.
| | - A Wayne Meikle
- ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, 200 2nd St. SW, Salt Lake City, UT, 55905, USA.,Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA.,Department of Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA
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21
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Dumont Y, Bastianetto S, Duranton A, Breton L, Quirion R. Immunohistochemical distribution of neuropeptide Y, peptide YY, pancreatic polypeptide-like immunoreactivity and their receptors in the epidermal skin of healthy women. Peptides 2015; 70:7-16. [PMID: 26002416 DOI: 10.1016/j.peptides.2015.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [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: 12/15/2014] [Revised: 05/07/2015] [Accepted: 05/12/2015] [Indexed: 11/19/2022]
Abstract
Few studies have suggested that neuropeptide Y (NPY) could play an important role in skin functions. However, the expression of NPY, the related peptides, peptide YY (PYY) and pancreatic polypeptide (PP) and their receptors have not been investigated in human skin. Using specific antisera directed against NPY, PYY, PP and the Y1, Y2, Y4 and Y5 receptor subtypes, we investigated here the expression of these markers. NPY-like immunoreactivity (ir) in the epidermal skin could not be detected. For the first time we report the presence of positive PP-like ir immunofluorescent signals in epidermal cells, i.e. keratinocytes of skin from three areas (abdomen, breast and face) obtained as surgical left-overs. The immunofluorescent signal of PP-like ir varies from very low to high level in all three areas. In contrast, PYY-like ir is only expressed in some cells and with varied level of intensity. Furthermore and for the first time we observed specific Y1 and Y4 receptor-like ir in all epidermal layers, while the Y2 and Y5 subtypes were absent. Interestingly, as seen in human epidermis, in Episkin, a reconstituted human epidermal layer, we detected the presence of PP-like as well as Y1-like and Y4-like ir. These data have shown the presence and distribution of PYY, PP and Y1 and Y4 receptors in the human skin and Episkin, suggesting possible novel roles of NPY related peptides and their receptors in skin homeostasis.
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Affiliation(s)
- Yvan Dumont
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montréal, QC, Canada H4H 1R3
| | - Stéphane Bastianetto
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montréal, QC, Canada H4H 1R3
| | | | | | - Rémi Quirion
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montréal, QC, Canada H4H 1R3.
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Hart PA, Baichoo E, Bi Y, Hinton A, Kudva YC, Chari ST. Pancreatic polypeptide response to a mixed meal is blunted in pancreatic head cancer associated with diabetes mellitus. Pancreatology 2015; 15:162-6. [PMID: 25766398 DOI: 10.1016/j.pan.2015.02.006] [Citation(s) in RCA: 36] [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] [Received: 12/10/2014] [Revised: 02/03/2015] [Accepted: 02/12/2015] [Indexed: 02/08/2023]
Abstract
INTRODUCTION Pancreatic polypeptide (PP) is a hormone secreted by islet cells of the ventral pancreas. It has been proposed that a blunted PP response to a mixed meal can distinguish diabetes mellitus (DM) secondary to pancreatic disease from other types of DM. We performed a proof of concept study to determine if PP response to a mixed meal discriminates DM secondary to pancreatic cancer (PaCDM) from type 2 DM (T2DM). METHODS We studied 18 subjects with new onset DM (PaCDM (n = 9) and T2DM (n = 9); matched for age and gender). Serum PP levels were measured at 0, 30, and 60 min following a mixed meal. Increases in PP levels from baseline were compared using the Wilcoxon test. RESULTS In PaCDM the PP increase following a mixed meal was less than T2DM at 30 min (median 60.0%, IQR, 33.0-119.8 vs. 134.5%, IQR, 117.5-265.9; p = 0.03), but statistically similar at 60 min (median 55.8%, interquartile range (IQR) 23.7-121.5 vs. 100.0%, IQR, 47.7-202.5; p = 0.17). In PaCDM subjects, the PP increase over baseline was smaller in those with a tumor located in the pancreatic head (n = 6) compared to the body/tail (n = 3) at 30 min (41.3% vs. 158.7%, p = 0.02) and at 60 min (37.4% vs. 167.4%,p = 0.04). CONCLUSIONS Subjects with PaCDM have a blunted PP response to a mixed meal compared to T2DM. However, the blunted PP response is only observed in those PaC subjects with a tumor located in the head of the pancreas. Confirmation in larger studies may suggest this could be used to aid screening for sporadic PaC.
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Affiliation(s)
- Phil A Hart
- Division of Gastroenterology and Hepatology, Mayo Clinic Rochester, MN, USA; Division of Gastroenterology, Hepatology, and Nutrition, The Ohio State University, Columbus, OH, USA
| | - Esha Baichoo
- Division of Gastroenterology and Hepatology, Mayo Clinic Rochester, MN, USA
| | - Yan Bi
- Division of Gastroenterology and Hepatology, Mayo Clinic Rochester, MN, USA
| | - Alice Hinton
- Division of Biostatistics, College of Public Health, The Ohio State University, Columbus, OH, USA
| | - Yogish C Kudva
- Division of Endocrinology, Mayo Clinic Rochester, MN, USA
| | - Suresh T Chari
- Division of Gastroenterology and Hepatology, Mayo Clinic Rochester, MN, USA.
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Sangan CB, Jover R, Heimberg H, Tosh D. In vitro reprogramming of pancreatic alpha cells towards a beta cell phenotype following ectopic HNF4α expression. Mol Cell Endocrinol 2015; 399:50-9. [PMID: 25224487 DOI: 10.1016/j.mce.2014.09.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [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: 10/04/2013] [Revised: 08/21/2014] [Accepted: 09/09/2014] [Indexed: 12/31/2022]
Abstract
There is currently a shortage of organ donors available for pancreatic beta cell transplantation into diabetic patients. An alternative source of beta cells is pre-existing pancreatic cells. While we know that beta cells can arise directly from alpha cells during pancreatic regeneration we do not understand the molecular basis for the switch in phenotype. The aim of the present study was to investigate if hepatocyte nuclear factor 4 alpha (HNF4α), a transcription factor essential for a normal beta cell phenotype, could induce the reprogramming of alpha cells towards potential beta cells. We utilised an in vitro model of pancreatic alpha cells, the murine αTC1-9 cell line. We initially characterised the αTC1-9 cell line before and following adenovirus-mediated ectopic expression of HNF4α. We analysed the phenotype at transcript and protein level and assessed its glucose-responsiveness. Ectopic HNF4α expression in the αTC1-9 cell line induced a change in morphology (1.7-fold increase in size), suppressed glucagon expression, induced key beta cell-specific markers (insulin, C-peptide, glucokinase, GLUT2 and Pax4) and pancreatic polypeptide (PP) and enabled the cells to secrete insulin in a glucose-regulated manner. In conclusion, HNF4α reprograms alpha cells to beta-like cells.
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Affiliation(s)
| | - Ramiro Jover
- Experimental Hepatology Unit. Hosp. La Fe & Dep. Biochemistry, University of Valencia. CIBERehd, Spain
| | - Harry Heimberg
- Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium
| | - David Tosh
- Centre for Regenerative Medicine, University of Bath, Bath, UK.
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Aragón F, Karaca M, Novials A, Maldonado R, Maechler P, Rubí B. Pancreatic polypeptide regulates glucagon release through PPYR1 receptors expressed in mouse and human alpha-cells. Biochim Biophys Acta Gen Subj 2014; 1850:343-51. [PMID: 25445712 DOI: 10.1016/j.bbagen.2014.11.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 11/01/2014] [Accepted: 11/04/2014] [Indexed: 12/24/2022]
Abstract
BACKGROUND Plasma levels of pancreatic polypeptide (PP) rise upon food intake. Although other pancreatic islet hormones, such as insulin and glucagon, have been extensively investigated, PP secretion and actions are still poorly understood. METHODS The release of PP upon glucose stimulation and the effects of PP on glucagon and insulin secretion were analyzed in isolated pancreatic islets. Expression of PP receptor (PPYR1) was investigated by immunoblotting, quantitative RT-PCR on sorted pancreatic islet cells, and immunohistochemistry. RESULTS In isolated mouse pancreatic islets, glucose stimulation increased PP release, while insulin secretion was up and glucagon release was down. Direct exposure of islets to PP inhibited glucagon release. In mouse islets, PPYR1 protein was observed by immunoblotting and quantitative RT-PCR revealed PPYR1 expression in the FACS-enriched glucagon alpha-cell fraction. Immunohistochemistry on pancreatic sections showed the presence of PPYR1 in alpha-cells of both mouse and human islets, while the receptor was absent in other islet cell types and exocrine pancreas. CONCLUSIONS Glucose stimulates PP secretion and PP inhibits glucagon release in mouse pancreatic islets. PP receptors are present in alpha-cells of mouse and human pancreatic islets. GENERAL SIGNIFICANCE These data demonstrate glucose-regulated secretion of PP and its effects on glucagon release through PPYR1 receptors expressed by alpha-cells.
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Affiliation(s)
- F Aragón
- Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona (PRBB), Barcelona, Spain
| | - M Karaca
- Department of Cell Physiology and Metabolism, Geneva University Medical Center, Geneva, Switzerland
| | - A Novials
- Diabetes Research Laboratory. IDIBAPS (Institut Investigacions Biomèdiques August Pi i Sunyer), CIBERDEM, Barcelona, Spain
| | - R Maldonado
- Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona (PRBB), Barcelona, Spain
| | - P Maechler
- Department of Cell Physiology and Metabolism, Geneva University Medical Center, Geneva, Switzerland.
| | - B Rubí
- Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona (PRBB), Barcelona, Spain.
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Stengel A, Goebel-Stengel M, Teuffel P, Hofmann T, Buße P, Kobelt P, Rose M, Klapp BF. Obese patients have higher circulating protein levels of dipeptidyl peptidase IV. Peptides 2014; 61:75-82. [PMID: 25219943 DOI: 10.1016/j.peptides.2014.09.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 09/01/2014] [Accepted: 09/01/2014] [Indexed: 12/21/2022]
Abstract
Dipeptidyl peptidase IV (DPPIV) is a protease with broad distribution involved in various homeostatic processes such as immune defense, psychoneuroendocrine functions and nutrition. While DPPIV protein levels were investigated in patients with hyporectic disorders, less is known under conditions of obesity. Therefore, we investigated DPPIV across a broad range of body mass index (BMI). Blood samples from hospitalized patients with normal weight (BMI 18.5-25 kg/m(2)), anorexia nervosa (BMI <17.5 kg/m(2)) and obesity (BMI 30-40, 40-50 and >50 kg/m(2), n = 15/group) were tested cross-sectionally and DPPIV concentration and total enzyme activity and the DPPIV targets, pancreatic polypeptide (PP) and glucagon-like peptide (GLP-1) were measured. DPPIV protein expression was detected in human plasma indicated by a strong band at the expected size of 110 kDa and another major band at 50 kDa, likely representing a fragment comprised of two heavy chains. Obese patients had higher DPPIV protein levels compared to normal weight and anorexics (+50%, p<0.05) resulting in a positive correlation with BMI (r = 0.34, p = 0.004). DPPIV serum activity was similar in all groups (p>0.05), while the concentration/activity ratio was higher in obese patients (p<0.05). Plasma PP levels were highest in anorexic patients (∼ 2-fold increase compared to other groups, p<0.05), whereas GLP-1 did not differ among groups (p<0.05). Taken together, circulating DPPIV protein levels depend on body weight with increased levels in obese resulting in an increased concentration/activity ratio. Since DPPIV deactivates food intake-inhibitory hormones like PP, an increased DPPIV concentration/activity ratio might contribute to reduced food intake-inhibitory signaling under conditions of obesity.
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Affiliation(s)
- Andreas Stengel
- Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
| | - Miriam Goebel-Stengel
- Department of Internal Medicine, Institute of Neurogastroenterology and Motility, Martin-Luther Hospital, Academic Teaching Institution of Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Pauline Teuffel
- Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Tobias Hofmann
- Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Petra Buße
- Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Peter Kobelt
- Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Matthias Rose
- Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Burghard F Klapp
- Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
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26
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Holler JPN, Schmitz J, Roehrig R, Wilker S, Hecker A, Padberg W, Grau V. Expression of peptide YY by human blood leukocytes. Peptides 2014; 58:78-82. [PMID: 24969624 DOI: 10.1016/j.peptides.2014.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 05/19/2014] [Accepted: 05/20/2014] [Indexed: 01/17/2023]
Abstract
Peptide YY is produced by L cells in the mucosa of the distal ileum, colon, and rectum and may have systemic and paracrine functions. We hypothesized that peptide YY is expressed by peripheral blood mononuclear cells. The purpose of the present study was to evaluate the expression of peptide YY mRNA and peptide by peripheral blood mononuclear cells and differentiated THP-1 cells after lipopolysaccharide treatment as an in vitro model of inflammation. Blood was drawn by venipuncture from 18- to 63-year-old healthy male blood donors (n=63); peptide YY mRNA expression levels were detected in peripheral blood mononuclear cells from all healthy male subjects. In 3 subjects, peripheral blood mononuclear cells were cultured for 3 and 24h and peptide YY was detected in the cell culture supernatant. In human monocytic THP-1 cells treated with phorbol-12-myristate-13-acetate to induce differentiation to macrophages, treatment with lipopolysaccharide caused down-regulation of peptide YY mRNA levels. In summary, freshly isolated peripheral blood mononuclear cells from healthy humans expressed peptide YY. In vitro data suggested that peptide YY expression is down-regulated by differentiation of monocytes to macrophages and proinflammatory stimuli.
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Affiliation(s)
- Julia Pia Natascha Holler
- Laboratory of Experimental Surgery, Department of General and Thoracic Surgery, Justus-Liebig-University, Feulgen-Str. 10-12, D-35385 Giessen, Germany.
| | - Jessica Schmitz
- Laboratory of Experimental Surgery, Department of General and Thoracic Surgery, Justus-Liebig-University, Feulgen-Str. 10-12, D-35385 Giessen, Germany.
| | - Rainer Roehrig
- Department of Anesthesiology, Intensive Care and Pain Medicine, Justus-Liebig-University of Giessen and Marburg, Campus Giessen, Rudolf-Bucheim-Straße 7, 35392 Giessen, Germany.
| | - Sigrid Wilker
- Laboratory of Experimental Surgery, Department of General and Thoracic Surgery, Justus-Liebig-University, Feulgen-Str. 10-12, D-35385 Giessen, Germany.
| | - Andreas Hecker
- Laboratory of Experimental Surgery, Department of General and Thoracic Surgery, Justus-Liebig-University, Feulgen-Str. 10-12, D-35385 Giessen, Germany.
| | - Winfried Padberg
- Laboratory of Experimental Surgery, Department of General and Thoracic Surgery, Justus-Liebig-University, Feulgen-Str. 10-12, D-35385 Giessen, Germany.
| | - Veronika Grau
- Laboratory of Experimental Surgery, Department of General and Thoracic Surgery, Justus-Liebig-University, Feulgen-Str. 10-12, D-35385 Giessen, Germany.
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27
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Kim W, Fiori JL, Shin YK, Okun E, Kim JS, Rapp PR, Egan JM. Pancreatic polypeptide inhibits somatostatin secretion. FEBS Lett 2014; 588:3233-9. [PMID: 25019573 DOI: 10.1016/j.febslet.2014.07.005] [Citation(s) in RCA: 20] [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] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 05/14/2014] [Accepted: 07/03/2014] [Indexed: 01/30/2023]
Abstract
Pancreatic polypeptide (PP) is a major agonist for neuropeptide Y4 receptors (NPY4R). While NPY4R has been identified in various tissues, the cells on which it is expressed and its function in those cells has not been clearly delineated. Here we report that NPY4R is present in all somatostatin-containing cells of tissues that we tested, including pancreatic islets, duodenum, hippocampus, and hypothalamus. Its agonism by PP decreases somatostatin secretion from human islets. Mouse embryonic hippocampal (mHippo E18) cells expressed NPY4Rs and their activation by PP consistently decreased somatostatin secretion. Furthermore, central injection of PP in mice induced c-Fos immunoreactivity in somatostatin-containing cells in the hippocampus compared with PBS-injected mice. In sum, our results identify PP as a pivotal modulator of somatostatin secretion.
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Affiliation(s)
- Wook Kim
- Department of Molecular Science and Technology, Ajou University, Suwon 443-749, South Korea
| | - Jennifer L Fiori
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Yu-Kyong Shin
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Eitan Okun
- The Mina and Everard Goodman Faculty of Life Sciences, The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Jung Seok Kim
- Department of Molecular Science and Technology, Ajou University, Suwon 443-749, South Korea
| | - Peter R Rapp
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Josephine M Egan
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
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28
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Chowdhury S, Wang S, Patterson BW, Reeds DN, Wice BM. The combination of GIP plus xenin-25 indirectly increases pancreatic polypeptide release in humans with and without type 2 diabetes mellitus. ACTA ACUST UNITED AC 2013; 187:42-50. [PMID: 24183983 DOI: 10.1016/j.regpep.2013.10.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [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: 06/28/2013] [Revised: 10/07/2013] [Accepted: 10/23/2013] [Indexed: 12/25/2022]
Abstract
Xenin-25 (Xen) is a 25-amino acid neurotensin-related peptide that activates neurotensin receptor-1 (NTSR1). We previously showed that Xen increases the effect of glucose-dependent insulinotropic polypeptide (GIP) on insulin release 1) in hyperglycemic mice via a cholinergic relay in the periphery independent from the central nervous system and 2) in humans with normal or impaired glucose tolerance, but not type 2 diabetes mellitus (T2DM). Since this blunted response to Xen defines a novel defect in T2DM, it is important to understand how Xen regulates islet physiology. On separate visits, subjects received intravenous graded glucose infusions with vehicle, GIP, Xen, or GIP plus Xen. The pancreatic polypeptide response was used as an indirect measure of cholinergic input to islets. The graded glucose infusion itself had little effect on the pancreatic polypeptide response whereas administration of Xen equally increased the pancreatic polypeptide response in humans with normal glucose tolerance, impaired glucose tolerance, and T2DM. The pancreatic polypeptide response to Xen was similarly amplified by GIP in all 3 groups. Antibody staining of human pancreas showed that NTSR1 is not detectable on islet endocrine cells, sympathetic neurons, blood vessels, or endothelial cells but is expressed at high levels on PGP9.5-positive axons in the exocrine tissue and at low levels on ductal epithelial cells. PGP9.5 positive nerve fibers contacting beta cells in the islet periphery were also observed. Thus, a neural relay, potentially involving muscarinic acetylcholine receptors, indirectly increases the effects of Xen on pancreatic polypeptide release in humans.
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Affiliation(s)
- Sara Chowdhury
- Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, Saint Louis, MO, United States
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29
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Ozeki J, Choi M, Endo-Umeda K, Sakurai K, Amano S, Makishima M. Enhanced transcription of pancreatic peptide YY by 1α-hydroxyvitamin D3 administration in streptozotocin-induced diabetic mice. Neuropeptides 2013; 47:329-32. [PMID: 23899497 DOI: 10.1016/j.npep.2013.07.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 06/29/2013] [Accepted: 07/05/2013] [Indexed: 12/17/2022]
Abstract
Peptide YY (PYY) is a peptide hormone secreted from L cells in the intestine in response to food intake that regulates appetite and gastrointestinal function. PYY is also produced in the pancreatic islets. The vitamin D receptor (VDR) is a nuclear receptor for the active form of vitamin D3 that regulates numerous physiological processes. VDR is expressed in the pancreatic islets and pharmacological VDR activation increases PYY expression in mouse peripheral islet cells. Although VDR is present in insulin-producing β cells as well as non-β cells, the role of β cell VDR in Pyy transcription remains unknown. We treated mice with streptozotocin to ablate β cells in the pancreas. Pancreatic Vdr mRNA expression was decreased in streptozotocin-induced diabetic mice. Interestingly, streptozotocin-treated mice exhibited increased basal Pyy expression and 1α-hydroxyvitamin D3 treatment further increased expression. Moreover, 1α-hydroxyvitamin D3 increased mRNA expression of pancreatic polypeptide and decreased that of neuropeptide Y in streptozotocin-induced diabetic mice but not in control mice. 1α-Hydroxyvitamin D3 slightly increased mRNA expression of insulin but transcript levels were nearly undetectable in the pancreas of streptozotocin-treated mice. Thus, VDR in non-β islet cells is involved in Pyy expression in the mouse pancreas. The findings from this β cell ablation study suggest a hormone transcription regulatory network composed of β cells and non-β cells.
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Affiliation(s)
- Jun Ozeki
- Division of Biochemistry, Department of Biomedical Sciences, Nihon University School of Medicine, 30-1 Oyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan; Division of Breast and Endocrine Surgery, Department of Surgery, Nihon University School of Medicine, 30-1 Oyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan
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30
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Patching SG. Surface plasmon resonance spectroscopy for characterisation of membrane protein-ligand interactions and its potential for drug discovery. Biochim Biophys Acta 2014; 1838:43-55. [PMID: 23665295 DOI: 10.1016/j.bbamem.2013.04.028] [Citation(s) in RCA: 257] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 04/25/2013] [Accepted: 04/29/2013] [Indexed: 11/22/2022]
Abstract
Surface plasmon resonance (SPR) spectroscopy is a rapidly developing technique for the study of ligand binding interactions with membrane proteins, which are the major molecular targets for validated drugs and for current and foreseeable drug discovery. SPR is label-free and capable of measuring real-time quantitative binding affinities and kinetics for membrane proteins interacting with ligand molecules using relatively small quantities of materials and has potential to be medium-throughput. The conventional SPR technique requires one binding component to be immobilised on a sensor chip whilst the other binding component in solution is flowed over the sensor surface; a binding interaction is detected using an optical method that measures small changes in refractive index at the sensor surface. This review first describes the basic SPR experiment and the challenges that have to be considered for performing SPR experiments that measure membrane protein-ligand binding interactions, most importantly having the membrane protein in a lipid or detergent environment that retains its native structure and activity. It then describes a wide-range of membrane protein systems for which ligand binding interactions have been characterised using SPR, including the major drug targets G protein-coupled receptors, and how challenges have been overcome for achieving this. Finally it describes some recent advances in SPR-based technology and future potential of the technique to screen ligand binding in the discovery of drugs. This article is part of a Special Issue entitled: Structural and biophysical characterisation of membrane protein-ligand binding.
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31
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Banerjee A, Onyuksel H. A novel peptide nanomedicine for treatment of pancreatogenic diabetes. Nanomedicine 2013; 9:722-8. [PMID: 23347897 DOI: 10.1016/j.nano.2012.12.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 12/26/2012] [Accepted: 12/31/2012] [Indexed: 01/25/2023]
Abstract
UNLABELLED Pancreatogenic diabetes (PD) is a potentially fatal disease that occurs secondary to pancreatic disorders. The current anti-diabetic therapy for PD is fraught with adverse effects that can increase morbidity. Here we investigated the efficacy of novel peptide nanomedicine: pancreatic polypeptide (PP) in sterically stabilized micelles (SSM) for management of PD. PP exhibits significant anti-diabetic efficacy but its short plasma half-life curtails its therapeutic application. To prolong and improve activity of PP in vivo, we evaluated the delivery of PP in SSM. PP-SSM administered to rats with PD, significantly improved glucose tolerance, insulin sensitivity and hepatic glycogen content compared to peptide in buffer. The studies established the importance of micellar nanocarriers in protecting enzyme-labile peptides in vivo and delivering them to target site, thereby enhancing their therapeutic efficacy. In summary, this study demonstrated that PP-SSM is a promising novel anti-diabetic nanomedicine and therefore should be further developed for management of PD. FROM THE CLINICAL EDITOR Pancreatic peptide was earlier demonstrated to address pancreatogenic diabetes, but its short half-life represented major difficulties in further development for therapeutic use. PP-SSM (pancreatic polypeptide in sterically stabilized micelles) is a promising novel anti-diabetic nanomedicine that enables prolonged half-life and increased bioactivity of PP, as shown in this novel study, paving the way toward clinical studies in the near future.
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Rickels MR, Bellin M, Toledo FG, Robertson RP, Andersen DK, Chari ST, Brand R, Frulloni L, Anderson MA, Whitcomb DC; PancreasFest Recommendation Conference Participants. Detection, evaluation and treatment of diabetes mellitus in chronic pancreatitis: recommendations from PancreasFest 2012. Pancreatology 2013; 13:336-42. [PMID: 23890130 DOI: 10.1016/j.pan.2013.05.002] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Revised: 05/06/2013] [Accepted: 05/07/2013] [Indexed: 02/07/2023]
Abstract
DESCRIPTION Diabetes and glucose intolerance are common complications of chronic pancreatitis, yet clinical guidance on their detection, classification, and management is lacking. METHODS A working group reviewed the medical problems, diagnostic methods, and treatment options for chronic pancreatitis-associated diabetes for a consensus meeting at PancreasFest 2012. RESULTS Guidance Statement 1.1: Diabetes mellitus is common in chronic pancreatitis. While any patient with chronic pancreatitis should be monitored for development of diabetes, those with long-standing duration of disease, prior partial pancreatectomy, and early onset of calcific disease may be at higher risk. Those patients developing diabetes mellitus are likely to have co-existing pancreatic exocrine insufficiency. Guidance Statement 1.2: Diabetes occurring secondary to chronic pancreatitis should be recognized as pancreatogenic diabetes (type 3c diabetes). Guidance Statement 2.1: The initial evaluation should include fasting glucose and HbA1c. These tests should be repeated annually. Impairment in either fasting glucose or HbA1c requires further evaluation. Guidance Statement 2.2: Impairment in either fasting glucose or HbA1c should be further evaluated by a standard 75 g oral glucose tolerance test. Guidance Statement 2.3: An absent pancreatic polypeptide response to mixed-nutrient ingestion is a specific indicator of type 3c diabetes. Guidance Statement 2.4: Assessment of pancreatic endocrine reserve, and importantly that of functional beta-cell mass, should be performed as part of the evaluation and follow-up for total pancreatectomy with islet autotransplantation (TPIAT). Guidance Statement 3: Patients with pancreatic diabetes shall be treated with specifically tailored medical nutrition and pharmacologic therapies. CONCLUSIONS Physicians should evaluate and treat glucose intolerance in patients with pancreatitis.
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Abstract
We report the case of a 46-year-old female patient with WDHA (watery diarrhea/hypokalemia/achlorhydria) syndrome caused by a pancreatic polypeptide-producing tumor in the head of the pancreas. Whereas VIP and other pancreatic endocrine hormones were in the normal range, only serum levels of pancreatic polypeptide were elevated. Imaging studies identified a pancreatic tumor in the head of the gland. After laparotomy, the tumor of 3 cm in size was enucleated. Final pathology documented a pancreatic endocrine tumor with immunohistochemical staining demonstrating the presence of pancreatic polypeptide. The patient remained cured after a follow-up of more than three years. The present case illustrates that, although rare, WDHA syndrome may be associated with a pancreatic polypeptide-secreting endocrine tumor of the pancreas.
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Affiliation(s)
- Vera Amrilleva
- Department of Surgery, Philipps University Marburg, Marburg, Germany
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