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Charvát V, Strnadová A, Myšková A, Sýkora D, Blechová M, Železná B, Kuneš J, Maletínská L, Pačesová A. Lipidized analogues of the anorexigenic CART (cocaine- and amphetamine-regulated transcript) neuropeptide show anorexigenic and neuroprotective potential in mouse model of monosodium-glutamate induced obesity. Eur J Pharmacol 2024:176864. [PMID: 39084452 DOI: 10.1016/j.ejphar.2024.176864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 07/26/2024] [Accepted: 07/29/2024] [Indexed: 08/02/2024]
Abstract
AIMS This study investigates the neuroprotective effects of lipidized analogues of 2-SS-CART(61-102) derived from anorexigenic neuropeptide cocaine- and amphetamine-regulated transcript peptide (CARTp) in light of the link between obesity, its comorbidities, and the development of Alzheimer's disease. METHODS We introduce novel lipidized analogues derived from 2-SS-CART(61-102), a specific analogue of natural CART(61-102), with two disulfide bridges. Using hypothermic PC12 cells, we tested the effect of the most potent analogues on Tau phosphorylation. We further described the anorexigenic and neuroprotective potential of subcutaneously (SC) injected lipidized CARTp analogue in a mouse model with prediabetes and obesity induced by neonatal monosodium glutamate (MSG) administration. RESULTS Compared to the non-lipidized 2-SS-CART(61-102), all lipidized analogues exhibited a potent binding affinity to PC12 cells and enhanced in vitro stability in rat plasma. Two most potent lipidized analogues attenuated hypothermia-induced Tau hyperphosphorylation at multiple epitopes. Subsequently, chronic SC treatment with palm-2-SS-CART(61-102) significantly decreased body weight and food intake, improved metabolic parameters, decreased level of pTau and increased neurogenesis in hippocampi of obese MSG mice CONCLUSION: Our unique CARTp analogue palm-2-SS-CART(61-102) shows promise as a potent anti-obesity and neuroprotective agent.
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Affiliation(s)
- Vilém Charvát
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic; First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Anna Strnadová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Aneta Myšková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic; University of Chemistry and Technology, Prague, Czech Republic
| | - David Sýkora
- University of Chemistry and Technology, Prague, Czech Republic
| | - Miroslava Blechová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Blanka Železná
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Jaroslav Kuneš
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic; Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Lenka Maletínská
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Andrea Pačesová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic.
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2
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Zhao Y, Peng X, Wang Q, Zhang Z, Wang L, Xu Y, Yang H, Bai J, Geng D. Crosstalk Between the Neuroendocrine System and Bone Homeostasis. Endocr Rev 2024; 45:95-124. [PMID: 37459436 DOI: 10.1210/endrev/bnad025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Indexed: 01/05/2024]
Abstract
The homeostasis of bone microenvironment is the foundation of bone health and comprises 2 concerted events: bone formation by osteoblasts and bone resorption by osteoclasts. In the early 21st century, leptin, an adipocytes-derived hormone, was found to affect bone homeostasis through hypothalamic relay and the sympathetic nervous system, involving neurotransmitters like serotonin and norepinephrine. This discovery has provided a new perspective regarding the synergistic effects of endocrine and nervous systems on skeletal homeostasis. Since then, more studies have been conducted, gradually uncovering the complex neuroendocrine regulation underlying bone homeostasis. Intriguingly, bone is also considered as an endocrine organ that can produce regulatory factors that in turn exert effects on neuroendocrine activities. After decades of exploration into bone regulation mechanisms, separate bioactive factors have been extensively investigated, whereas few studies have systematically shown a global view of bone homeostasis regulation. Therefore, we summarized the previously studied regulatory patterns from the nervous system and endocrine system to bone. This review will provide readers with a panoramic view of the intimate relationship between the neuroendocrine system and bone, compensating for the current understanding of the regulation patterns of bone homeostasis, and probably developing new therapeutic strategies for its related disorders.
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Affiliation(s)
- Yuhu Zhao
- Department of Orthopedics, The First Affiliated Hospital of Soochow University; Orthopedics Institute, Medical College, Soochow University, Suzhou, Jiangsu 215006, China
| | - Xiaole Peng
- Department of Orthopedics, The First Affiliated Hospital of Soochow University; Orthopedics Institute, Medical College, Soochow University, Suzhou, Jiangsu 215006, China
| | - Qing Wang
- Department of Orthopedics, The First Affiliated Hospital of Soochow University; Orthopedics Institute, Medical College, Soochow University, Suzhou, Jiangsu 215006, China
| | - Zhiyu Zhang
- Department of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, China
| | - Liangliang Wang
- Department of Orthopedics, The Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University, Changzhou, Jiangsu 213000, China
| | - Yaozeng Xu
- Department of Orthopedics, The First Affiliated Hospital of Soochow University; Orthopedics Institute, Medical College, Soochow University, Suzhou, Jiangsu 215006, China
| | - Huilin Yang
- Department of Orthopedics, The First Affiliated Hospital of Soochow University; Orthopedics Institute, Medical College, Soochow University, Suzhou, Jiangsu 215006, China
| | - Jiaxiang Bai
- Department of Orthopedics, The First Affiliated Hospital of Soochow University; Orthopedics Institute, Medical College, Soochow University, Suzhou, Jiangsu 215006, China
- Department of Orthopedics, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei 230022, China
| | - Dechun Geng
- Department of Orthopedics, The First Affiliated Hospital of Soochow University; Orthopedics Institute, Medical College, Soochow University, Suzhou, Jiangsu 215006, China
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3
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Weaver C, Antony M, Fite J, Murugan P, Nelson AC, Manivel JC. Cocaine and amphetamine regulated transcript (CART): a newly characterized neuropeptide in human prostate. Biotech Histochem 2023; 98:508-522. [PMID: 37615074 DOI: 10.1080/10520295.2023.2245328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2023] Open
Abstract
Cocaine and amphetamine regulated transcript (CART) is a somatostatin-like polypeptide. CART has been localized in the CNS, hypothalamo-pituitary-adrenocortical (HPA) axis, pancreatic islets and enteric nervous system. We investigated the cellular localization of CART in normal human prostate, benign prostatic hyperplasia, prostatic intraepithelial neoplasia and acinar adenocarcinoma. CART was assessed using immunohistochemistry (IHC) and in situ hybridization (ISH), and its gene expression was identified by RTqPCR. We found cellular expression of CART in both normal prostatic luminal secretory epithelial cells neuroendocrine cells (NEC) of both ducts and acini. The cellular appearance indicated a cycle of neuropeptide synthesis and secretion as validated by ISH/IHC concordance. RTqPCR analysis also validated the immunohistochemical data and gene expression, which both indicated low to moderate expression in prostatic tissues. CART expression also was increased in both neuroendocrine and glandular epithelial cell populations from samples of benign prostatic hyperplasia as validated by IHC, ISH and RTqPCR. CART expression was markedly diminished and, in some cases, entirely absent in tissues of prostatic intraepithelial neoplasia and adenocarcinoma. Owing to loss of CART expression in adenocarcinoma and its increase in benign prostatic hyperplasia, CART may prove to be an important prostate marker.
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Affiliation(s)
- Cyprian Weaver
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
- Lillihei Heart Institute, University of Minnesota, Minneapolis, MN, USA
| | - Marie Antony
- Department of Medicine, Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, MN, USA
| | - Jack Fite
- Lillihei Heart Institute, University of Minnesota, Minneapolis, MN, USA
| | - Paari Murugan
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA
| | - Andrew C Nelson
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA
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4
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Hampton RF, Jimenez-Gonzalez M, Stanley SA. Unravelling innervation of pancreatic islets. Diabetologia 2022; 65:1069-1084. [PMID: 35348820 PMCID: PMC9205575 DOI: 10.1007/s00125-022-05691-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/08/2022] [Indexed: 01/05/2023]
Abstract
The central and peripheral nervous systems play critical roles in regulating pancreatic islet function and glucose metabolism. Over the last century, in vitro and in vivo studies along with examination of human pancreas samples have revealed the structure of islet innervation, investigated the contribution of sympathetic, parasympathetic and sensory neural pathways to glucose control, and begun to determine how the structure and function of pancreatic nerves are disrupted in metabolic disease. Now, state-of-the art techniques such as 3D imaging of pancreatic innervation and targeted in vivo neuromodulation provide further insights into the anatomy and physiological roles of islet innervation. Here, we provide a summary of the published work on the anatomy of pancreatic islet innervation, its roles, and evidence for disordered islet innervation in metabolic disease. Finally, we discuss the possibilities offered by new technologies to increase our knowledge of islet innervation and its contributions to metabolic regulation.
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Affiliation(s)
- Rollie F Hampton
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Maria Jimenez-Gonzalez
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Sarah A Stanley
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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Abels M, Riva M, Shcherbina L, Fischer AHT, Banke E, Degerman E, Lindqvist A, Wierup N. Overexpressed beta cell CART increases insulin secretion in mouse models of insulin resistance and diabetes. Peptides 2022; 151:170747. [PMID: 35065097 DOI: 10.1016/j.peptides.2022.170747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 01/14/2022] [Accepted: 01/14/2022] [Indexed: 12/15/2022]
Abstract
Impaired beta cell function and beta cell death are key features of type 2 diabetes (T2D). Cocaine- and amphetamine-regulated transcript (CART) is necessary for normal islet function in mice. CART increases glucose-stimulated insulin secretion in vivo in mice and in vitro in human islets and CART protects beta cells against glucotoxicity-induced cell death in vitro in rats. Furthermore, beta cell CART is upregulated in T2D patients and in diabetic rodent models as a consequence of hyperglycaemia. The aim of this study was to assess the impact of upregulated beta cell CART on islet hormone secretion and glucose homeostasis in a transgenic mouse model. To this end, mice with beta cell-specific overexpression of CART (CARTtg mice) were generated. CARTtg mice challenged by aging, high fat diet feeding or streptozotocin treatment were phenotyped with respect to in vivo and in vitro insulin and glucagon secretion, glucose homeostasis, and beta cell mass. In addition, the impact of adenoviral overexpression of CART on insulin secretion was studied in INS-1 832/13 cells. CARTtg mice had a normal metabolic phenotype under basal conditions. On the other hand, with age CARTtg mice displayed increased insulin secretion and improved glucose elimination, compared with age-matched WT mice. Furthermore, compared with WT controls, CARTtg mice had increased insulin secretion after feeding a high fat diet, as well as lower glucose levels and higher insulin secretion after streptozotocin treatment. Viral overexpression of CART in INS-1 832/13 cells resulted in increased glucose-stimulated insulin secretion. Together, these results imply that beta cell CART acts to increase insulin secretion when beta cell function is challenged. We propose that the increase in beta cell CART is part of a compensatory mechanisms trying to counteract the hyperglycaemia in T2D.
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Affiliation(s)
- Mia Abels
- Lund University Diabetes Centre, Malmö, Sweden
| | - Matteo Riva
- Lund University Diabetes Centre, Malmö, Sweden
| | | | | | - Elin Banke
- Lund University Diabetes Centre, Malmö, Sweden
| | | | | | - Nils Wierup
- Lund University Diabetes Centre, Malmö, Sweden.
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6
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Wierup N, Abels M, Shcherbina L, Lindqvist A. The role of CART in islet biology. Peptides 2022; 149:170708. [PMID: 34896575 DOI: 10.1016/j.peptides.2021.170708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/03/2021] [Accepted: 12/03/2021] [Indexed: 10/19/2022]
Abstract
Cocaine- and amphetamine-regulated transcript (CART) is mostly known for its appetite regulating effects in the central nervous system. However, CART is also highly expressed in the peripheral nervous system as well as in certain endocrine cells. Our group has dedicated more than 20 years to understand the role of CART in the pancreatic islets and in this review we summarize what is known to date about CART expression and function in the islets. CART is expressed in both islet cells and nerve fibers innervating the islets. Large species differences are at hand and CART expression is highly dynamic and increased during development, as well as in Type 2 Diabetes and certain endocrine tumors. In the human islets CART is expressed in alpha cells and beta cells and the expression is increased in T2D patients. CART increases insulin secretion, reduces glucagon secretion, and protects against beta cell death by reducing apoptosis and increasing proliferation. It is still not fully understood how CART mediates its effects or which receptors that are involved. Nevertheless, CART is endowed with several properties that are beneficial in a T2D perspective. Many of the described effects of CART resemble those of GLP-1, and interestingly CART has been found to potentiate some of the effects of GLP-1, paving the way for CART-based treatments in combination with GLP-1-based drugs.
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Affiliation(s)
- Nils Wierup
- Lund University Diabetes Centre, Malmö, Sweden.
| | - Mia Abels
- Lund University Diabetes Centre, Malmö, Sweden
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7
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Job MO, Kuhar MJ. Commentary: GPR160 De-Orphanization Reveals Critical Roles in Neuropathic Pain in Rodents (Finally, a Receptor for CART Peptide). ADVANCES IN DRUG AND ALCOHOL RESEARCH 2021; 1:10012. [PMID: 38410642 PMCID: PMC10896429 DOI: 10.3389/adar.2021.10012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 08/26/2021] [Indexed: 02/28/2024]
Affiliation(s)
- Martin O Job
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, NJ, United States
| | - Michael J Kuhar
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
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8
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Chriett S, Lindqvist A, Shcherbina L, Edlund A, Abels M, Asplund O, Martínez López JA, Ottosson-Laakso E, Hatem G, Prasad RB, Groop L, Eliasson L, Hansson O, Wierup N. SCRT1 is a novel beta cell transcription factor with insulin regulatory properties. Mol Cell Endocrinol 2021; 521:111107. [PMID: 33309639 DOI: 10.1016/j.mce.2020.111107] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 11/13/2020] [Accepted: 11/30/2020] [Indexed: 01/06/2023]
Abstract
Here we show that scratch family transcriptional repressor 1 (SCRT1), a zinc finger transcriptional regulator, is a novel regulator of beta cell function. SCRT1 was found to be expressed in beta cells in rodent and human islets. In human islets, expression of SCRT1 correlated with insulin secretion capacity and the expression of the insulin (INS) gene. Furthermore, SCRT1 mRNA expression was lower in beta cells from T2D patients. siRNA-mediated Scrt1 silencing in INS-1832/13 cells, mouse- and human islets resulted in impaired glucose-stimulated insulin secretion and decreased expression of the insulin gene. This is most likely due to binding of SCRT1 to E-boxes of the Ins1 gene as shown with ChIP. Scrt1 silencing also reduced the expression of several key beta cell transcription factors. Moreover, Scrt1 mRNA expression was reduced by glucose and SCRT1 protein was found to translocate between the nucleus and the cytosol in a glucose-dependent fashion in INS-1832/13 cells as well as in a rodent model of T2D. SCRT1 was also regulated by a GSK3β-dependent SCRT1-serine phosphorylation. Taken together, SCRT1 is a novel beta cell transcription factor that regulates insulin secretion and is affected in T2D.
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Affiliation(s)
- S Chriett
- Lund University Diabetes Centre, Malmö, Sweden
| | - A Lindqvist
- Lund University Diabetes Centre, Malmö, Sweden
| | | | - A Edlund
- Lund University Diabetes Centre, Malmö, Sweden
| | - M Abels
- Lund University Diabetes Centre, Malmö, Sweden
| | - O Asplund
- Lund University Diabetes Centre, Malmö, Sweden
| | - J A Martínez López
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | | | - G Hatem
- Lund University Diabetes Centre, Malmö, Sweden
| | - R B Prasad
- Lund University Diabetes Centre, Malmö, Sweden
| | - L Groop
- Lund University Diabetes Centre, Malmö, Sweden; Finnish Institute of Molecular Medicine, Helsinki, Finland
| | - L Eliasson
- Lund University Diabetes Centre, Malmö, Sweden
| | - O Hansson
- Lund University Diabetes Centre, Malmö, Sweden; Finnish Institute of Molecular Medicine, Helsinki, Finland
| | - N Wierup
- Lund University Diabetes Centre, Malmö, Sweden.
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Drott CJ, Norman D, Espes D. CART decreases islet blood flow, but has no effect on total pancreatic blood flow and glucose tolerance in anesthetized rats. Peptides 2021; 135:170431. [PMID: 33098940 DOI: 10.1016/j.peptides.2020.170431] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 10/12/2020] [Accepted: 10/12/2020] [Indexed: 01/08/2023]
Abstract
Cocaine- and amphetamine-regulated transcript (CART) is a neurotransmitter and hormone, involved in the regulation of e.g. food intake, body weight, reward and addiction, and stress response. CART has also been found to affect insulin secretion and beta cell morphology, both in vivo and in vitro. Furthermore, CART affects regulation of the cardiovascular system and helps to modulate vascular tone. The present study evaluated the local effect of CART on the pancreatic and islet circulation and function. CART (25 μg/h) or saline, combinations of CART and endothelin-A receptor antagonist (BQ123; 100 μg/kg), and glucose (2 g/kg) were intravenously infused in Sprague Dawley rats followed by blood flow measurements using a microsphere technique. Separately, CART-infused animals underwent an intravenous glucose tolerance test (ivGTT). The direct effect of CART on insulin release was investigated using isolated islets from Sprague Dawley rats. CART reduced islet blood flow, without reduction in total pancreatic blood flow. The normal glucose-induced islet blood flow increase was diminished by CART, albeit still present. Simultaneously, CART had no effect on systemic-, intestinal- or renal blood flow. The endothelin-A receptor antagonist BQ123 together with CART had no pancreatic vascular effects. We found that CART has pronounced vascular constrictive actions restricted to the pancreatic islet circulation but had no effect on insulin release neither in vivo nor in vitro. The mechanisms behind the vascular effects are still unknown, but may reflect a direct action on pancreatic blood vessels.
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Affiliation(s)
- Carl Johan Drott
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden.
| | - Daniel Norman
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Daniel Espes
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden; Department of Medical Sciences, Uppsala University, Uppsala, Sweden
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10
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The relationship of body condition indicators with the level of plasma cocaine and amphetamine regulated transcript and energy metabolism indicators in dairy cows. ACTA VET BRNO 2019. [DOI: 10.2754/avb201988010011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The factors affecting the course of lactation and intensity of milk secretion include the condition and body weight, as well as chewing time. A little researched factor is also the cocaine and amphetamine regulated transcript (CART) which has been suggested to have an anorexigenic function. This study sought to examine the dependent indicators of condition and chewing time on daily milk yield assessment in the context of the concentration of CART, glucose and ß-hydroxybutyrate (BHB) in blood. Higher CART levels contributed to shorter chewing time (min/day), lower body condition and lower body weight. Blood glucose concentration showed a stronger correlation with body weight and condition than with blood BHB concentration. An important practical aspect of the results is the relationship shown between CART and chewing time and the potential relation between daily milk production and chewing time. Importantly, the animals with lower daily milk production had relatively the highest concentration CART. This may suggest that this neuropeptide is indirectly involved in milk production, especially by shortening the chewing time. The obtained results help to better explain the mechanisms involved in milk secretion and the process of rumination and digestion. More research is required, but they also show important functions of other examined neuropeptides.
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Jansson L, Carlsson PO. Pancreatic Blood Flow with Special Emphasis on Blood Perfusion of the Islets of Langerhans. Compr Physiol 2019; 9:799-837. [PMID: 30892693 DOI: 10.1002/cphy.c160050] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The pancreatic islets are more richly vascularized than the exocrine pancreas, and possess a 5- to 10-fold higher basal and stimulated blood flow, which is separately regulated. This is reflected in the vascular anatomy of the pancreas where islets have separate arterioles. There is also an insulo-acinar portal system, where numerous venules connect each islet to the acinar capillaries. Both islets and acini possess strong metabolic regulation of their blood perfusion. Of particular importance, especially in the islets, is adenosine and ATP/ADP. Basal and stimulated blood flow is modified by local endothelial mediators, the nervous system as well as gastrointestinal hormones. Normally the responses to the nervous system, especially the parasympathetic and sympathetic nerves, are fairly similar in endocrine and exocrine parts. The islets seem to be more sensitive to the effects of endothelial mediators, especially nitric oxide, which is a permissive factor to maintain the high basal islet blood flow. The gastrointestinal hormones with pancreatic effects mainly influence the exocrine pancreatic blood flow, whereas islets are less affected. A notable exception is incretin hormones and adipokines, which preferentially affect islet vasculature. Islet hormones can influence both exocrine and endocrine blood vessels, and these complex effects are discussed. Secondary changes in pancreatic and islet blood flow occur during several conditions. To what extent changes in blood perfusion may affect the pathogenesis of pancreatic diseases is discussed. Both type 2 diabetes mellitus and acute pancreatitis are conditions where we think there is evidence that blood flow may contribute to disease manifestations. © 2019 American Physiological Society. Compr Physiol 9:799-837, 2019.
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Affiliation(s)
- Leif Jansson
- Uppsala University, Department of Medical Cell Biology, Uppsala, Sweden
| | - Per-Ola Carlsson
- Uppsala University, Department of Medical Cell Biology, Uppsala, Sweden.,Uppsala University, Department of Medical Sciences, Uppsala, Sweden
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12
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Ahmadian-Moghadam H, Sadat-Shirazi MS, Zarrindast MR. Cocaine- and amphetamine-regulated transcript (CART): A multifaceted neuropeptide. Peptides 2018; 110:56-77. [PMID: 30391426 DOI: 10.1016/j.peptides.2018.10.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 10/15/2018] [Accepted: 10/29/2018] [Indexed: 12/12/2022]
Abstract
Over the last 35 years, the continuous discovery of novel neuropeptides has been the key to the better understanding of how the central nervous system has integrated with neuronal signals and behavioral responses. Cocaine and amphetamine-regulated transcript (CART) was discovered in 1995 in the rat striatum but later was found to be highly expressed in the hypothalamus. The widespread distribution of CART peptide in the brain complicated the understanding of the role played by this neurotransmitter. The main objective of the current compact review is to piece together the fragments of available information about origin, expression, distribution, projection, and function of CART peptides. Accumulative evidence suggests CART as a neurotransmitter and neuroprotective agent that is mainly involved in regulation of feeding, addiction, stress, anxiety, innate fear, neurological disease, neuropathic pain, depression, osteoporosis, insulin secretion, learning, memory, reproduction, vision, sleep, thirst and body temperature. In spite of the vast number of studies about the CART, the overall pictures about the CART functions are sketchy. First, there is a lack of information about cloned receptor, specific agonist and antagonist. Second, CART peptides are detected in discrete sets of neurons that can modulate countless activities and third; CART peptides exist in several fragments due to post-translational processing. For these reasons the overall picture about the CART peptides are sketchy and confounding.
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Affiliation(s)
- Hamid Ahmadian-Moghadam
- Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Mohammad-Reza Zarrindast
- Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Endocrinology and Metabolism Research Institute, Tehran University of Medical Science, Tehran, Iran.
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13
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Shcherbina L, Lindqvist A, Thorén Fischer AH, Ahlqvist E, Zhang E, Falkmer SE, Renström E, Koffert J, Honka H, Wierup N. Intestinal CART is a regulator of GIP and GLP-1 secretion and expression. Mol Cell Endocrinol 2018; 476:8-16. [PMID: 29627317 DOI: 10.1016/j.mce.2018.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 03/26/2018] [Accepted: 04/05/2018] [Indexed: 12/20/2022]
Abstract
Impaired incretin effect is a culprit in Type 2 Diabetes. Cocaine- and amphetamine-regulated transcript (CART) is a regulatory peptide controlling pancreatic islet hormone secretion and beta-cell survival. Here we studied the potential expression of CART in enteroendocrine cells and examined the role of CART as a regulator of incretin secretion and expression. CART expression was found in glucose-dependent insulinotropic polypeptide (GIP)-producing K-cells and glucagon-like peptide-1 (GLP-1)-producing L-cells in human duodenum and jejunum and circulating CART levels were increased 60 min after a meal in humans. CART expression was increased by fatty acids and GIP, but unaffected by glucose in GLUTag and STC-1 cells. Exogenous CART had no effect on GIP and GLP-1 expression and secretion in GLUTag or STC-1 cells, but siRNA-mediated silencing of CART reduced GLP-1 expression and secretion. Furthermore, acute intravenous administration of CART increased GIP and GLP-1 secretion during an oral glucose-tolerance test in mice. We conclude that CART is a novel constituent of human K- and L-cells with stimulatory actions on incretin secretion and that interfering with the CART system may be a therapeutic avenue for T2D.
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Affiliation(s)
| | - A Lindqvist
- Lund University Diabetes Centre, Malmö, Sweden
| | | | - E Ahlqvist
- Lund University Diabetes Centre, Malmö, Sweden
| | - E Zhang
- Lund University Diabetes Centre, Malmö, Sweden
| | - S E Falkmer
- Department of Clinical Pathology, Ryhov Hospital, Jönköping, Sweden
| | - E Renström
- Lund University Diabetes Centre, Malmö, Sweden
| | - J Koffert
- Turku PET Centre, University of Turku, Turku, Finland
| | - H Honka
- Turku PET Centre, University of Turku, Turku, Finland
| | - N Wierup
- Lund University Diabetes Centre, Malmö, Sweden.
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14
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Rakovska A, Baranyi M, Windisch K, Petkova-Kirova P, Gagov H, Kalfin R. Neurochemical evidence that cocaine- and amphetamine-regulated transcript (CART) 55-102 peptide modulates the dopaminergic reward system by decreasing the dopamine release in the mouse nucleus accumbens. Brain Res Bull 2017; 134:246-252. [PMID: 28802898 DOI: 10.1016/j.brainresbull.2017.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 07/05/2017] [Accepted: 08/07/2017] [Indexed: 01/11/2023]
Abstract
CART (Cocaine- and Amphetamine-Regulated Transcript) peptide is a neurotransmitter naturally occurring in the CNS and found mostly in nucleus accumbens, ventrotegmental area, ventral pallidum, amygdalae and striatum, brain regions associated with drug addiction. In the nucleus accumbens, known for its significant role in motivation, pleasure, reward and reinforcement learning, CART peptide inhibits cocaine and amphetamine-induced dopamine-mediated increases in locomotor activity and behavior, suggesting a CART peptide interaction with the dopaminergic system. Thus in the present study, we examined the effect of CART (55-102) peptide on the basal, electrical field stimulation-evoked (EFS-evoked) (30V, 2Hz, 120 shocks) and returning basal dopamine (DA) release and on the release of the DA metabolites 3,4-dihydroxyphenyl acetaldehyde (DOPAL), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 3,4-dihydroxyphenylethanol (DOPET), 3-methoxytyramine (3-MT) as well as on norepinephrine (NE) and dopamine-o-quinone (Daq) in isolated mouse nucleus accumbens, in a preparation, in which any CART peptide effects on the dendrites or soma of ventral tegmental projection neurons have been excluded. We further extended our study to assess the effect of CART (55-102) peptide on basal cocaine-induced release of dopamine and its metabolites DOPAL, DOPAC, HVA, DOPET and 3-MT as well as on NE and Daq. To analyze the amount of [3H]dopamine, dopamine metabolites, Daq and NE in the nucleus accumbens superfusate, a high-pressure liquid chromatography (HPLC), coupled with electrochemical, UV and radiochemical detections was used. CART (55-102) peptide, 0.1μM, added alone, exerted: (i) a significant decrease in the basal and EFS-evoked levels of extracellular dopamine (ii) a significant increase in the EFS-evoked and returning basal levels of the dopamine metabolites DOPAC and HVA, major products of dopamine degradation and (iii) a significant decrease in the returning basal levels of DOPET. At the same concentration, 0.1μM, CART (55-102) peptide did not have any effect on the release of noradrenaline. In the presence of CART (55-102) peptide, 0.1μM, the effect of cocaine, 30μM, on the basal dopamine release was inhibited and the effect on the basal DOPAC release substantially increased. To our knowledge, our findings are the first to show direct neurochemical evidence that CART (55-102) peptide plays a neuromodulatory role on the dopaminergic reward system by decreasing dopamine in the mouse nucleus accumbens and by attenuating cocaine-induced effects on dopamine release.
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Affiliation(s)
- Angelina Rakovska
- Lab. "Neuropeptides", Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 23, 1113, Sofia, Bulgaria.
| | - Maria Baranyi
- Department of Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Szigony u. 43, H-1083, Budapest, Hungary
| | - Katalin Windisch
- Department of Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Szigony u. 43, H-1083, Budapest, Hungary
| | - Polina Petkova-Kirova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str. bl. 21, 1113, Sofia, Bulgaria
| | - Hristo Gagov
- Faculty of Biology, Sofia University St. Kliment Ohridski, Dragan Tsankov Str. 8, 1164, Sofia, Bulgaria
| | - Reni Kalfin
- Lab. "Neuropeptides", Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 23, 1113, Sofia, Bulgaria
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15
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Shcherbina L, Edlund A, Esguerra JLS, Abels M, Zhou Y, Ottosson-Laakso E, Wollheim CB, Hansson O, Eliasson L, Wierup N. Endogenous beta-cell CART regulates insulin secretion and transcription of beta-cell genes. Mol Cell Endocrinol 2017; 447:52-60. [PMID: 28237718 DOI: 10.1016/j.mce.2017.02.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 02/16/2017] [Accepted: 02/16/2017] [Indexed: 01/20/2023]
Abstract
Impaired beta-cell function is key to the development of type 2 diabetes. Cocaine- and amphetamine-regulated transcript (CART) is an islet peptide with insulinotropic and glucagonostatic properties. Here we studied the role of endogenous CART in beta-cell function. CART silencing in INS-1 (832/13) beta-cells reduced insulin secretion and production, ATP levels and beta-cell exocytosis. This was substantiated by reduced expression of several exocytosis genes, as well as reduced expression of genes important for insulin secretion and processing. In addition, CART silencing reduced the expression of a network of transcription factors essential for beta-cell function. Moreover, in RNAseq data from human islet donors, CARTPT expression levels correlated with insulin, exocytosis genes and key beta-cell transcription factors. Thus, endogenous beta-cell CART regulates insulin expression and secretion in INS-1 (832/13) cells, via actions on the exocytotic machinery and a network of beta-cell transcription factors. We conclude that CART is important for maintaining the beta-cell phenotype.
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Affiliation(s)
- L Shcherbina
- Lund University Diabetes Centre, Skåne University Hospital, Jan Waldenströms Gata 35, 214 28 Malmö, Sweden
| | - A Edlund
- Lund University Diabetes Centre, Skåne University Hospital, Jan Waldenströms Gata 35, 214 28 Malmö, Sweden
| | - J L S Esguerra
- Lund University Diabetes Centre, Skåne University Hospital, Jan Waldenströms Gata 35, 214 28 Malmö, Sweden
| | - M Abels
- Lund University Diabetes Centre, Skåne University Hospital, Jan Waldenströms Gata 35, 214 28 Malmö, Sweden
| | - Y Zhou
- Lund University Diabetes Centre, Skåne University Hospital, Jan Waldenströms Gata 35, 214 28 Malmö, Sweden
| | - E Ottosson-Laakso
- Lund University Diabetes Centre, Skåne University Hospital, Jan Waldenströms Gata 35, 214 28 Malmö, Sweden
| | - C B Wollheim
- Lund University Diabetes Centre, Skåne University Hospital, Jan Waldenströms Gata 35, 214 28 Malmö, Sweden; Department of Cell Physiology and Metabolism, University Medical Center, 1 Rue Michel-Servet, CH-1211 Genève 4, Switzerland
| | - O Hansson
- Lund University Diabetes Centre, Skåne University Hospital, Jan Waldenströms Gata 35, 214 28 Malmö, Sweden
| | - L Eliasson
- Lund University Diabetes Centre, Skåne University Hospital, Jan Waldenströms Gata 35, 214 28 Malmö, Sweden
| | - N Wierup
- Lund University Diabetes Centre, Skåne University Hospital, Jan Waldenströms Gata 35, 214 28 Malmö, Sweden.
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16
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Dimitri P, Rosen C. The Central Nervous System and Bone Metabolism: An Evolving Story. Calcif Tissue Int 2017; 100:476-485. [PMID: 27501818 DOI: 10.1007/s00223-016-0179-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 07/19/2016] [Indexed: 12/21/2022]
Abstract
Our understanding of the control of skeletal metabolism has undergone a dynamic shift in the last two decades, primarily driven by our understanding of energy metabolism. Evidence demonstrating that leptin not only influences bone cells directly, but that it also plays a pivotal role in controlling bone mass centrally, opened up an investigative process that has changed the way in which skeletal metabolism is now perceived. Other central regulators of bone metabolism have since been identified including neuropeptide Y (NPY), serotonin, endocannabinoids, cocaine- and amphetamine-regulated transcript (CART), adiponectin, melatonin and neuromedin U, controlling osteoblast and osteoclast differentiation, proliferation and function. The sympathetic nervous system was originally identified as the predominant efferent pathway mediating central signalling to control skeleton metabolism, in part regulated through circadian genes. More recent evidence points to a role of the parasympathetic nervous system in the control of skeletal metabolism either through muscarinic influence of sympathetic nerves in the brain or directly via nicotinic receptors on osteoclasts, thus providing evidence for broader autonomic skeletal regulation. Sensory innervation of bone has also received focus again widening our understanding of the complex neuronal regulation of bone mass. Whilst scientific advance in this field of bone metabolism has been rapid, progress is still required to understand how these model systems work in relation to the multiple confounders influencing skeletal metabolism, and the relative balance in these neuronal systems required for skeletal growth and development in childhood and maintaining skeletal integrity in adulthood.
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Affiliation(s)
- Paul Dimitri
- The Academic Unit of Child Health, Department of Paediatric Endocrinology, University of Sheffield, Sheffield, UK.
| | - Cliff Rosen
- Maine Medical Center Research Institute Scarborough, Scarborough, ME, 04074, USA
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17
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Xu W, Zhang Y, Bai M, Zhou F, Deng R, Ji X, Zhang J, Liu Y, Zhou L, Wang X. Glucose enhances rat islet function via stimulating CART expression. Biochem Biophys Res Commun 2016; 481:84-89. [PMID: 27823935 DOI: 10.1016/j.bbrc.2016.11.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 11/03/2016] [Indexed: 12/30/2022]
Abstract
Cocaine- and amphetamine-regulated transcript (CART) is an anorexigenic peptide widely expressed in the central and peripheral nervous systems, as well as in endocrine cells. CART is markedly upregulated in the β-cells of several rodent models of type-2 diabetes. The stimulatory effect of exogenous CART peptide on insulin secretion is cAMP dependent. Glucose is the most important regulator of islet function. However, the role of CART in glucose-potentiated insulin secretion remains unclear. Here, our results showed that glucose time- and dose-dependently elicited CART mRNA expression in rat islets. Both the glucokinase agonist GKA50 and the long-acting GLP-1 analogue exendin-4 increased CART mRNA expression. The protein kinase A (PKA) inhibitor H89 and the inactivation of cAMP response element-binding protein (CREB) suppressed forskolin-stimulated CART mRNA expression. Furthermore, CART overexpression amplified insulin secretion from rat islets in response to glucose and forskolin, and ameliorated dexamethasone-impaired insulin secretion. These findings suggest that islet-derived CART is involved, at least in part, in high glucose-potentiated pancreatic β-cell function.
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Affiliation(s)
- Wan Xu
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
| | - Yuqing Zhang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
| | - Mengyao Bai
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
| | - Feiye Zhou
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
| | - Ruyuan Deng
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
| | - Xueying Ji
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
| | - Juan Zhang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
| | - Yun Liu
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
| | - Libin Zhou
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
| | - Xiao Wang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
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18
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Abels M, Riva M, Bennet H, Ahlqvist E, Dyachok O, Nagaraj V, Shcherbina L, Fred RG, Poon W, Sörhede-Winzell M, Fadista J, Lindqvist A, Kask L, Sathanoori R, Dekker-Nitert M, Kuhar MJ, Ahrén B, Wollheim CB, Hansson O, Tengholm A, Fex M, Renström E, Groop L, Lyssenko V, Wierup N. CART is overexpressed in human type 2 diabetic islets and inhibits glucagon secretion and increases insulin secretion. Diabetologia 2016; 59:1928-37. [PMID: 27338624 DOI: 10.1007/s00125-016-4020-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 05/23/2016] [Indexed: 11/30/2022]
Abstract
AIMS/HYPOTHESIS Insufficient insulin release and hyperglucagonaemia are culprits in type 2 diabetes. Cocaine- and amphetamine-regulated transcript (CART, encoded by Cartpt) affects islet hormone secretion and beta cell survival in vitro in rats, and Cart (-/-) mice have diminished insulin secretion. We aimed to test if CART is differentially regulated in human type 2 diabetic islets and if CART affects insulin and glucagon secretion in vitro in humans and in vivo in mice. METHODS CART expression was assessed in human type 2 diabetic and non-diabetic control pancreases and rodent models of diabetes. Insulin and glucagon secretion was examined in isolated islets and in vivo in mice. Ca(2+) oscillation patterns and exocytosis were studied in mouse islets. RESULTS We report an important role of CART in human islet function and glucose homeostasis in mice. CART was found to be expressed in human alpha and beta cells and in a subpopulation of mouse beta cells. Notably, CART expression was several fold higher in islets of type 2 diabetic humans and rodents. CART increased insulin secretion in vivo in mice and in human and mouse islets. Furthermore, CART increased beta cell exocytosis, altered the glucose-induced Ca(2+) signalling pattern in mouse islets from fast to slow oscillations and improved synchronisation of the oscillations between different islet regions. Finally, CART reduced glucagon secretion in human and mouse islets, as well as in vivo in mice via diminished alpha cell exocytosis. CONCLUSIONS/INTERPRETATION We conclude that CART is a regulator of glucose homeostasis and could play an important role in the pathophysiology of type 2 diabetes. Based on the ability of CART to increase insulin secretion and reduce glucagon secretion, CART-based agents could be a therapeutic modality in type 2 diabetes.
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Affiliation(s)
- Mia Abels
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Matteo Riva
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Hedvig Bennet
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Emma Ahlqvist
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Oleg Dyachok
- Department of Medical Cell Biology, Uppsala University Biomedical Centre, Uppsala, Sweden
| | - Vini Nagaraj
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Liliya Shcherbina
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Rikard G Fred
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Wenny Poon
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | | | - Joao Fadista
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Andreas Lindqvist
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Lena Kask
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Ramasri Sathanoori
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | | | - Michael J Kuhar
- The Yerkes Research Center of Emory University, Atlanta, GA, USA
| | - Bo Ahrén
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Claes B Wollheim
- Department of Cell Physiology and Metabolism, University Medical Centre, Geneva, Switzerland
| | - Ola Hansson
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University Biomedical Centre, Uppsala, Sweden
| | - Malin Fex
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Erik Renström
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Leif Groop
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
| | - Valeriya Lyssenko
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden
- Steno Diabetes Center A/S, Gentofte, Denmark
| | - Nils Wierup
- Lund University Diabetes Centre, Skåne University Hospital, Lund and Malmö, Sweden.
- Lund University Diabetes Centre, Skåne University Hospital, Department of Clinical Sciences in Malmö, Unit of Neuroendocrine Cell Biology, Lund University, Clinical Research Centre 91:12, Jan Waldenströms gata 35, 20502, Malmö, Sweden.
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19
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Gilon P. Cocaine- and amphetamine-regulated transcript: a novel regulator of energy homeostasis expressed in a subpopulation of pancreatic islet cells. Diabetologia 2016; 59:1855-9. [PMID: 27421727 DOI: 10.1007/s00125-016-4052-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 06/28/2016] [Indexed: 12/11/2022]
Abstract
Type 2 diabetes is characterised by chronic hyperglycaemia and its incidence is highly increased by exaggerated food consumption. It results from a lack of insulin action/production, but growing evidence suggests that it might also involve hyperglucagonaemia and impaired control of glucose homeostasis by the brain. In recent years, the cocaine and amphetamine-regulated transcript (CART) peptides have generated a lot of interest in the battle against obesity because, via the brain, they exert anorexic effects and they increase energy expenditure. They are also localised, outside the brain, in discrete regions of the body and play a hormonal role in controlling various functions. In this issue of Diabetologia, the Wierup group (doi: 10.1007/s00125-016-4020-6 ) shows that CART peptides are expressed heterogeneously in islet cells of various species, including humans, and that their expression is upregulated in diabetes. The authors also shine a spotlight on some interesting effects of CART peptides on islet function, including stimulation of insulin secretion and inhibition of glucagon release. CART peptides would thus be at the centre of a cooperation between the brain and the endocrine pancreas to control glucose homeostasis. Although the mechanisms of action of CART peptides remain enigmatic because no specific receptor for these peptides has so far been discovered, their potential therapeutic use is evident and represents a new challenge for future research.
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Affiliation(s)
- Patrick Gilon
- Pôle d'endocrinologie, diabète et nutrition, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Avenue Hippocrate 55, B1.55.06, 1200, Brussels, Belgium.
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20
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Expression of Cocaine and Amphetamine Regulated Transcript (CART) in the Porcine Intramural Neurons of Stomach in the Course of Experimentally Induced Diabetes Mellitus. J Mol Neurosci 2015; 57:376-85. [PMID: 26266486 DOI: 10.1007/s12031-015-0618-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 07/07/2015] [Indexed: 10/23/2022]
Abstract
In the present study, the effect of streptozotocin-induced diabetes on the cocaine- and amphetamine-regulated transcript-like immunoreactive (CART-LI) enteric nervous structures was investigated within the porcine stomach. To induce diabetes, the pigs were administered intravenously streptozotocin at a dose of 150 mg/kg of body weight. A significant decrease of the number of CART-LI perikarya was observed in the myenteric plexus of the gastric antrum, corpus, and pylorus in the experimental group. In contrast, submucous plexus was devoid of CART-positive neuronal cells both in control and experimental animals. In the control group, the highest densities of CART-LI nerve fibers were observed in the circular muscle layer of antrum and slightly less nerve fibers were present in the muscle layer of corpus and pylorus. In turn, submucous layer of all studied stomach regions revealed relatively smaller number of CART-positive nerve fibers. Diabetes caused statistically significant decrease in the expression of CART-LI nerve fibers only in the antrum circular muscle layer. Also, no changes in the CART-like immunoreactivity in the intraganglionic nerve fibers were observed. The obtained results suggest that acute hyperglycemia produced significant reduction of the CART expression in enteric perikarya throughout entire stomach as well as decrease of density the CART-LI fibers in circular muscle layer of the antrum. Additionally, we suggest that CART might be involved in the regulation of stomach function especially in the gastric motility.
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21
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Janiuk I, Młynek K. Immunodetection of cocaine- and amphetamine-regulated transcript in bovine pancreas. Acta Histochem 2015; 117:545-50. [PMID: 25953739 DOI: 10.1016/j.acthis.2015.04.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/14/2015] [Accepted: 04/15/2015] [Indexed: 01/02/2023]
Abstract
This study was aimed at identifying and determining the configuration of structures which contain the cocaine- and amphetamine-regulated transcript peptide (CART) in the bovine pancreas. The study material was collected from 20 animals. The distribution of CART in the bovine pancreas was investigated, by an immunohistochemical evaluation. CART peptide in the normal pancreas has been identified in intrapancreatic ganglia, nerve fibres and in endocrine cells of Langerhans islets and exocrine pancreas. CART immunoreactive nerve fibres innervate the exocrine and endocrine regions and the intrapancreatic ganglia, where they form a moderate number of networks, encircling the cell bodies. The few CART-immunoreactive endocrine cells, that appear in the bovine pancreas, are not limited to the islet cells, where they form a subpopulation of CART-containing cells, but are also individually distributed in the exocrine region. Furthermore, CART has been visualized in nerve fibres, innervating pancreatic outlet ducts and blood vessels. CART plays a physiological role in the integrated mechanisms that regulate both endocrine and exocrine pancreatic secretion. These results are consistent with the hypothesis that CART expression in nerve fibres and intrapancreatic ganglia is a common feature of the mammalian pancreas, whereas its expression in endocrine cells appears to be restricted to single cells of the bovine pancreas.
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Abstract
The islets of Langerhans are key regulators of glucose homeostasis and have been known as a structure for almost one and a half centuries. During the twentieth century several different cell types were described in the islets of different species and at different developmental stages. Six cell types with identified hormonal product have been described so far by the use of histochemical staining methods, transmission electron microscopy, and immunohistochemistry. Thus, glucagon-producing α-cells, insulin-producing β-cells, somatostatin-producing δ-cells, pancreatic polypeptide-producing PP-cells, serotonin-producing enterochromaffin-cells, and gastrin-producing G-cells have all been found in the mammalian pancreas at least at some developmental stage. Species differences are at hand and age-related differences are also to be considered. Eleven years ago a novel cell type, the ghrelin cell, was discovered in the human islets. Subsequent studies have shown the presence of islet ghrelin cells in several animals, including mouse, rat, gerbils, and fish. The developmental regulation of ghrelin cells in the islets of mice has gained a lot of interest and several studies have added important pieces to the puzzle of molecular mechanisms and the genetic regulation that lead to differentiation into mature ghrelin cells. A body of evidence has shown that ghrelin is an insulinostatic hormone, and the potential for blockade of ghrelin signalling as a therapeutic avenue for type 2 diabetes is intriguing. Furthermore, ghrelin-expressing pancreatic tumours have been reported and ghrelin needs to be taken into account when diagnosing pancreatic tumours. In this review article, we summarise the knowledge about islet ghrelin cells obtained so far.
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Affiliation(s)
- Nils Wierup
- Unit of Neuroendocrine Cell Biology, Department of Clinical Sciences in Malmö, Lund University Diabetes Centre, Clinical Research Centre, Scania University Hospital, Jan Waldenströms gata 35, SE 205 02 Malmö, Sweden Imaging Team, Novo Nordisk A/S, Novo Nordisk Park, DK2760 Måløv, Denmark
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23
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Bech PR, Martin NM, Ramachandran R, Bloom SR. The biochemical utility of chromogranin A, chromogranin B and cocaine- and amphetamine-regulated transcript for neuroendocrine neoplasia. Ann Clin Biochem 2013; 51:8-21. [DOI: 10.1177/0004563213489670] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Neuroendocrine neoplasia (NEN) is a heterogeneous group of tumours and often represents a therapeutic challenge to clinicians. The peptides chromogranin A (CgA), chromogranin B (CgB) and cocaine- and amphetamine-regulated transcript (CART) are widely distributed throughout the neuroendocrine system. CgA and CgB have been used as general NEN biomarkers for many years, while CART has only recently been identified. Of these biomarkers, CgA is the most commonly used. However, circulating CgA concentrations exhibit considerable intra-individual biological variation, are altered by proton pump inhibitors (PPIs) and somatostatin analogues and are elevated in non-NEN malignancies. Therefore, interpretation of CgA results must be in the context of these confounding factors. The effects of treatment and non-NEN conditions on circulating CgB and CART concentrations are less well understood. CgB is less affected by impaired renal function and PPIs than CgA; while, circulating CART concentrations lack a diurnal variation in humans and are more reliable markers of pancreatic NEN malignancy than CgA. The utility of circulating CgA measurements in NEN prognosis, surveillance and disease recurrence has been widely investigated. However, the utility of CgB and CART in NEN management is yet to be elucidated. Further studies are needed to establish whether CgB and CART are useful alternatives to CgA.
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Affiliation(s)
- PR Bech
- Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
| | - NM Martin
- Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
| | - R Ramachandran
- Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
| | - SR Bloom
- Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
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24
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Cocaine- and amphetamine-regulated transcript is expressed in adipocytes and regulate lipid- and glucose homeostasis. ACTA ACUST UNITED AC 2013; 182:35-40. [DOI: 10.1016/j.regpep.2012.12.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 10/12/2012] [Accepted: 12/17/2012] [Indexed: 01/14/2023]
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25
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Kasacka I, Janiuk I, Lewandowska A, Bekisz A, Lebkowski W. Distribution pattern of CART-containing neurons and cells in the human pancreas. Acta Histochem 2012; 114:695-9. [PMID: 22257587 DOI: 10.1016/j.acthis.2011.12.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 11/17/2011] [Accepted: 12/08/2011] [Indexed: 11/19/2022]
Abstract
Cocaine- and amphetamine-regulated transcript (CART) has been shown to play a critical role in appetite suppression, cell survival, thermoregulation, glucose sensing, stimulation of hormone secretion, as well as for the regulatory function of the islets of Langerhans. Although the principal site of CART synthesis has already been reported, our knowledge of the subject is mainly based on and limited to research conducted on animals owing to difficulties in obtaining human samples. Therefore, the primary goal of the reported study was an attempt to identify and localize CART in healthy human pancreas. Nineteen deceased subjects (donors of organs) with normal pancreas and alimentary tract were used in the study. After determination of brain death and confirmation of death by the relevant doctors committee, pancreas samples, about 1cm long, were collected from each corpse (the same part of the pancreas) after the organs were harvested for transplantation. Paraffin sections were made and stained with hematoxylin and eosin and then subjected to CART immunohistochemistry. In the normal pancreas of human adults, CART is mainly present in both nerve fibers and in nerve cell bodies in pancreatic ganglia. In addition to pancreatic neurons, immunoreactivity to CART was also seen in islet endocrine cells. This is the first report on the presence of CART-IR structures in the normal human pancreas. CART should be now added to the numerous regulatory peptides that are involved in the complex regulation of pancreatic endocrine and exocrine processes.
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Affiliation(s)
- Irena Kasacka
- Department of Histology and Cytophysiology, Medical University of Bialystok, Kilińskiego 1 str., 15-089 Białystok, Poland.
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Landerholm K, Shcherbina L, Falkmer SE, Järhult J, Wierup N. Expression of Cocaine- and Amphetamine-Regulated Transcript Is Associated with Worse Survival in Small Bowel Carcinoid Tumors. Clin Cancer Res 2012; 18:3668-76. [DOI: 10.1158/1078-0432.ccr-11-2513] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Forced swim stress elicits region-specific changes in CART expression in the stress axis and stress regulatory brain areas. Brain Res 2012; 1432:56-65. [DOI: 10.1016/j.brainres.2011.11.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 10/28/2011] [Accepted: 11/03/2011] [Indexed: 11/22/2022]
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Landerholm K, Falkmer SE, Järhult J, Sundler F, Wierup N. Cocaine- and amphetamine-regulated transcript in neuroendocrine tumors. Neuroendocrinology 2011; 94:228-36. [PMID: 21832817 DOI: 10.1159/000329044] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Accepted: 05/05/2011] [Indexed: 01/28/2023]
Abstract
BACKGROUND/AIMS Cocaine- and amphetamine-regulated transcript (CART) is an anorexigenic regulatory peptide highly expressed in the brain's appetite control centers, but also in peripheral neurons and in endocrine cells in the adrenal medulla, thyroid, pancreatic islets, and in the gastrointestinal tract. Plasma levels of CART were recently shown to be elevated in patients with neuroendocrine tumors (NETs), but the cellular sources of CART in NETs have remained unknown. The aim of the study was to establish whether CART is expressed in various types of NETs and, if so, to examine the frequency, distribution and phenotype of CART-expressing cells. METHODS Tumor specimens from 133 NETs originating in the stomach, ileum, rectum, pancreas and thyroid were examined with immunohistochemistry and in situ hybridization. The expression of CART was quantified and the CART-expressing cells were phenotyped by double staining for established markers and hormones. RESULTS CART-expressing tumor cells were found in the majority of the examined NETs. The expression pattern of CART was highly heterogeneous not only between tumors, but also within individual tumors. In 14% of the NETs, CART was found in a major population of the tumor cells. CONCLUSION CART is produced in the majority of NETs, regardless of tumor origin. This likely explains the elevated levels of circulating CART in certain NETs patients, as recently described. CART could therefore prove to be a useful tool in the diagnostics of NETs not only in blood samples, but also in histopathological specimens.
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Prokunina-Olsson L, Hall JL. Evidence for neuroendocrine function of a unique splicing form of TCF7L2 in human brain, islets and gut. Diabetologia 2010; 53:712-6. [PMID: 20033802 PMCID: PMC2830605 DOI: 10.1007/s00125-009-1640-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Accepted: 11/30/2009] [Indexed: 11/30/2022]
Abstract
AIMS/HYPOTHESIS Variants in the TCF7L2 gene remain the strongest genetic associations with increased risk of type 2 diabetes. Recently, we identified a unique splicing form of TCF7L2 expressed in pancreatic islets, pancreas and colon and detected by assay 'ex13-13b'. The expression of ex13-13b strongly correlated with proinsulin in glucose-stimulated pancreatic islets, suggesting a potential role for this form in the development of type 2 diabetes. The goal of this study was to further characterise this unique TCF7L2 splicing form in human tissues. METHODS We used a panel of 34 human tissues and 80 human cell lines to measure the expression of assay ex13-13b with use of quantitative RT-PCR. RESULTS The highest expression of assay ex13-13b was detected in several areas of the brain (hypothalamus/thalamus, occipital lobe) and in neuronal cell line SHS5Y5. Low expression was confirmed in pancreatic islets, small intestine, pancreas and colon, while no expression was detected in other human tissues and cell lines. The expression of assay ex13-13b correlated with the gene for cocaine- and amphetamine-regulated transcript (CART, also known as CARTPT) in a panel of human tissues (n = 12, r = 0.85, p = 0.00046), pancreatic islets (n = 23, r = 0.62, p = 0.0016) and colon (n = 98, r = 0.54, p < 0.0001). CONCLUSIONS/INTERPRETATION The significant correlation between expression of a unique splicing form of TCF7L2, named here TCF7L2-NE, and CART, the gene for an anorexigenic neurohormone expressed in the central and peripheral nervous system, suggests that these transcripts may share neuroendocrine functions important for brain, gut and pancreatic islets.
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Affiliation(s)
- L Prokunina-Olsson
- Laboratory of Translational Genomics, National Cancer Institute, National Institutes of Health, 8717 Grovemont Circle, Bethesda, MD 20892-4605, USA.
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Li Y, Liu Q, Yang Y, Lv Y, Chen L, Bai C, Nan X, Wang Y, Pei X. Regulatory role of neuron-restrictive silencing factor in the specific expression of cocaine- and amphetamine-regulated transcript gene. J Neurochem 2008; 106:1314-24. [DOI: 10.1111/j.1471-4159.2008.05487.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Singh MK, Elefteriou F, Karsenty G. Cocaine and amphetamine-regulated transcript may regulate bone remodeling as a circulating molecule. Endocrinology 2008; 149:3933-41. [PMID: 18450969 PMCID: PMC2488246 DOI: 10.1210/en.2008-0109] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cocaine- and amphetamine-regulated transcript (CART) is one of the two known mediators of the leptin regulation of bone mass. Cart is expressed in both the brain and peripheral tissues such as the pituitary gland and the pancreatic islets. Cart(-/-) mice present a low bone mass phenotype due to an isolated increase in osteoclast number. In an effort to rescue their bone phenotype, we delivered recombinant CART in the third ventricle of the mutant mice but never recorded any improvement of the low bone mass, although this procedure could affect fat pad mass. In contrast, transgenic mice harboring a 2-fold increase in CART circulating level display a high bone mass due to an isolated decrease in osteoclast number and could rescue the low bone mass phenotype of the Cart(-/-) mice. Thus, our results suggest that in its capacity of a regulator of bone remodeling, CART may act more as a circulating molecule than a neuropeptide.
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Affiliation(s)
- Manvendra K Singh
- Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, 701 West 168th Street, New York, New York 10032, USA
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Arciszewski MB, Całka J, Majewski M. Cocaine- and amphetamine-regulated transcript (CART) is expressed in the ovine pancreas. Ann Anat 2008; 190:292-9. [DOI: 10.1016/j.aanat.2007.11.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Revised: 11/26/2007] [Accepted: 11/26/2007] [Indexed: 01/09/2023]
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Bech P, Winstanley V, Murphy KG, Sam AH, Meeran K, Ghatei MA, Bloom SR. Elevated cocaine- and amphetamine-regulated transcript immunoreactivity in the circulation of patients with neuroendocrine malignancy. J Clin Endocrinol Metab 2008; 93:1246-53. [PMID: 18211969 PMCID: PMC2729185 DOI: 10.1210/jc.2007-1946] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Cocaine- and amphetamine-regulated transcript (CART) codes for a peptide widely distributed in nervous and endocrine tissues. CART immunoreactivity (CART-LI) has been detected in human insulinomas. OBJECTIVE The objective of the study was to investigate the measurement of plasma CART-LI as a tumor marker of neuroendocrine malignancy. DESIGN AND SUBJECTS Plasma CART-LI levels were measured in 401 patients with a range of diagnoses: neuroendocrine malignancy (n = 131), after removal of neuroendocrine malignancy (n = 27), without any form of tumor or renal impairment (n = 192), with renal impairment (n = 17) and with nonneuroendocrine tumors (n = 34). Chromatography methods were used to investigate CART-LI circulating in human plasma. RESULTS The upper limit of normal calculated for CART-LI was 150 pmol/liter. Mean circulating plasma CART-LI among neuroendocrine tumor patients was 440 pmol/liter, 56% of subjects having levels greater than 150 pmol/liter. Measuring CART-LI in addition to chromogranin (Cg)-A improved the sensitivity for neuroendocrine malignancy from 85 to 91%, whereas combined use of CgA and CgB had a joint sensitivity of 89%. Of 38 patients with pancreatic neuroendocrine tumors, 71% had plasma CART-LI levels greater than 150 pmol/liter, increasing to 95% in those classified with progressive disease (n = 20, mean CART-LI 625 pmol/liter), compared with 80% for CgA. Chromatographic analysis suggests that circulating CART-LI is present as one major form, which may correspond to CART (62-102) or another unknown form. CONCLUSIONS We demonstrate CART-LI as a specific tumor marker in patients with a range of neuroendocrine tumors. Used in combination with CgA, CART-LI measurement has the potential to improve sensitivity in diagnosis and follow-up of neuroendocrine tumors, in particular progressive pancreatic neuroendocrine tumors.
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Affiliation(s)
- Paul Bech
- Department of Metabolic Medicine, Hammersmith Hospital, Commonwealth Building, 6th Floor, Imperial College London, London W12 0NN, United Kingdom.
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Sen A, Bettegowda A, Jimenez-Krassel F, Ireland JJ, Smith GW. Cocaine- and amphetamine-regulated transcript regulation of follicle-stimulating hormone signal transduction in bovine granulosa cells. Endocrinology 2007; 148:4400-10. [PMID: 17569753 DOI: 10.1210/en.2007-0332] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Regulation of estradiol production, central to ovarian follicular development and reproductive function, is mediated by a complex interaction of pituitary gonadotropins such as FSH with locally produced regulatory molecules. We previously demonstrated a negative association of expression of cocaine-and amphetamine-regulated transcript (CART) with follicle health status and a novel local negative role for CART in regulation of basal estradiol production by bovine granulosa cells. However, effects of CART on FSH-induced estradiol production and the underlying mechanism(s) mediating the physiological actions of CART on granulosa cells are not known. Objectives of the present study were to determine effects of CART on basal and FSH-induced intracellular cAMP levels, aromatase mRNA, estradiol accumulation, calcium signaling, and the intracellular signaling pathways involved using primary cultures of bovine granulosa cells. CART treatment potently inhibits the FSH-induced rise in granulosa cell cAMP levels, estradiol accumulation, and aromatase mRNA. Furthermore, results show that calcium is essential for FSH-induced cAMP and estradiol accumulation, and CART significantly inhibits FSH-induced calcium influx. Select G protein and protein kinase inhibitors were used to elucidate pathways involved in CART actions. The inhibitory actions of CART on FSH signaling and estradiol production are mediated via a G(o/i)-dependent pathway, whereas none of the other signaling inhibitors had any effect on CART actions. Results demonstrate novel potent inhibitory effects of CART on multiple components of the FSH signaling pathway linked to estradiol production and follicular development and shed new insight into the mechanism of action of CART potentially pertinent within and beyond the reproductive system.
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Affiliation(s)
- Aritro Sen
- Laboratory of Mammalian Reproductive Biology and Genomics, Department of Animal Science, Michigan State University, 1230 Anthony Hall, East Lansing, Michigan 48824, USA
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Wierup N, Gunnarsdóttir A, Ekblad E, Sundler F. Characterisation of CART-containing neurons and cells in the porcine pancreas, gastro-intestinal tract, adrenal and thyroid glands. BMC Neurosci 2007; 8:51. [PMID: 17625001 PMCID: PMC1934373 DOI: 10.1186/1471-2202-8-51] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Accepted: 07/11/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The peptide CART is widely expressed in central and peripheral neurons, as well as in endocrine cells. Known peripheral sites of expression include the gastrointestinal (GI) tract, the pancreas, and the adrenal glands. In rodent pancreas CART is expressed both in islet endocrine cells and in nerve fibers, some of which innervate the islets. Recent data show that CART is a regulator of islet hormone secretion, and that CART null mutant mice have islet dysfunction. CART also effects GI motility, mainly via central routes. In addition, CART participates in the regulation of the hypothalamus-pituitary-adrenal-axis. We investigated CART expression in porcine pancreas, GI-tract, adrenal glands, and thyroid gland using immunocytochemistry. RESULTS CART immunoreactive (IR) nerve cell bodies and fibers were numerous in pancreatic and enteric ganglia. The majority of these were also VIP IR. The finding of intrinsic CART containing neurons indicates that pancreatic and GI CART IR nerve fibers have an intrinsic origin. No CART IR endocrine cells were detected in the pancreas or in the GI tract. The adrenal medulla harboured numerous CART IR endocrine cells, most of which were adrenaline producing. In addition CART IR fibers were frequently seen in the adrenal cortex and capsule. The capsule also contained CART IR nerve cell bodies. The majority of the adrenal CART IR neuronal elements were also VIP IR. CART IR was also seen in a substantial proportion of the C-cells in the thyroid gland. The majority of these cells were also somatostatin IR, and/or 5-HT IR, and/or VIP IR. CONCLUSION CART is a major neuropeptide in intrinsic neurons of the porcine GI-tract and pancreas, a major constituent of adrenaline producing adrenomedullary cells, and a novel peptide of the thyroid C-cells. CART is suggested to be a regulatory peptide in the porcine pancreas, GI-tract, adrenal gland and thyroid.
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Affiliation(s)
- Nils Wierup
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Anna Gunnarsdóttir
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Department of Pediatric Surgery, Lund University Hospital, Lund, Sweden
| | - Eva Ekblad
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Frank Sundler
- Department of Experimental Medical Science, Lund University, Lund, Sweden
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Bibliography. Current world literature. Diabetes and the endocrine pancreas. Curr Opin Endocrinol Diabetes Obes 2007; 14:170-96. [PMID: 17940437 DOI: 10.1097/med.0b013e3280d5f7e9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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