1
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Gerstenberg MK, Andersen DB, Torz L, Castorena CM, Bookout AL, Hartmann B, Rehfeld JF, Petersen N, Holst JJ, Kuhre RE. Weight loss by calorie restriction does not alter appetite-regulating gut hormone responses from perfused rat small intestine. Acta Physiol (Oxf) 2023; 238:e13947. [PMID: 36755506 DOI: 10.1111/apha.13947] [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: 07/27/2022] [Revised: 01/27/2023] [Accepted: 02/06/2023] [Indexed: 02/10/2023]
Abstract
AIM Postprandial secretion of the appetite-inhibiting hormones, glucagon-like peptide-1 (GLP-1), and peptide YY are reduced with obesity. It is unclear if the reduced secretion persists following weight loss (WL), if other appetite-inhibiting hormones are also reduced, and if so whether reduced secretion results from intrinsic changes in the gut. METHODS To address whether WL may restore secretion of GLP-1 and other appetite-inhibiting hormones, we performed a gut perfusion study of the small intestine in diet-induced obese (DIO) rats after WL. A 20% weight loss (means ± SEM (g): 916 ± 53 vs. 703 ± 35, p < 0.01, n = 7) was induced by calorie restriction, and maintained stable for ≥7 days prior to gut perfusion to allow for complete renewal of enteroendocrine cells. Age-matched DIO rats were used as comparator. Several gut hormones were analyzed from the venous effluent, and gene expression was performed on gut tissue along the entire length of the intestine. RESULTS Secretion of cholecystokinin, gastrin, glucose-dependent insulinotropic peptide, GLP-1, neurotensin, and somatostatin was not affected by WL during basal conditions (p ≥ 0.25) or in response to macronutrients and bile acids (p ≥ 0.14). Glucose absorption was indistinguishable following WL. The expression of genes encoding the studied peptides, macronutrient transporters (glucose, fructose, and di-/tripeptides) and bile acid receptors did also not differ between DIO and WL groups. CONCLUSIONS These data suggest that the attenuated postprandial responses of GLP-1, as well as reduced responses of other appetite-inhibiting gut hormones, in people living with obesity may persist after weight loss and may contribute to their susceptibility for weight regain.
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Affiliation(s)
| | - Daniel B Andersen
- Department of Biomedical Sciences, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark.,Novo Nordisk Center for Basic Metabolic Research, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
| | - Lola Torz
- Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark
| | | | - Angie L Bookout
- Global Drug Discovery, Novo Nordisk A/S, Seattle, Washington, USA
| | - Bolette Hartmann
- Department of Biomedical Sciences, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark.,Novo Nordisk Center for Basic Metabolic Research, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
| | - Jens F Rehfeld
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | | | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark.,Novo Nordisk Center for Basic Metabolic Research, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
| | - Rune E Kuhre
- Department of Biomedical Sciences, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark.,Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark
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2
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Makki K, Brolin H, Petersen N, Henricsson M, Christensen DP, Khan MT, Wahlström A, Bergh PO, Tremaroli V, Schoonjans K, Marschall HU, Bäckhed F. 6α-hydroxylated bile acids mediate TGR5 signalling to improve glucose metabolism upon dietary fiber supplementation in mice. Gut 2023; 72:314-324. [PMID: 35697422 PMCID: PMC9872241 DOI: 10.1136/gutjnl-2021-326541] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 05/31/2022] [Indexed: 01/27/2023]
Abstract
OBJECTIVE Dietary fibres are essential for maintaining microbial diversity and the gut microbiota can modulate host physiology by metabolising the fibres. Here, we investigated whether the soluble dietary fibre oligofructose improves host metabolism by modulating bacterial transformation of secondary bile acids in mice fed western-style diet. DESIGN To assess the impact of dietary fibre supplementation on bile acid transformation by gut bacteria, we fed conventional wild-type and TGR5 knockout mice western-style diet enriched or not with cellulose or oligofructose. In addition, we used germ-free mice and in vitro cultures to evaluate the activity of bacteria to transform bile acids in the caecal content of mice fed with western-style diet enriched with oligofructose. Finally, we treated wild-type and TGR5 knockout mice orally with hyodeoxycholic acid to assess its antidiabetic effects. RESULTS We show that oligofructose sustains the production of 6α-hydroxylated bile acids from primary bile acids by gut bacteria when fed western-style diet. Mechanistically, we demonstrated that the effects of oligofructose on 6α-hydroxylated bile acids were microbiota dependent and specifically required functional TGR5 signalling to reduce body weight gain and improve glucose metabolism. Furthermore, we show that the 6α-hydroxylated bile acid hyodeoxycholic acid stimulates TGR5 signalling, in vitro and in vivo, and increases GLP-1R activity to improve host glucose metabolism. CONCLUSION Modulation of the gut microbiota with oligofructose enriches bacteria involved in 6α-hydroxylated bile acid production and leads to TGR5-GLP1R axis activation to improve body weight and metabolism under western-style diet feeding in mice.
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Affiliation(s)
- Kassem Makki
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Harald Brolin
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Natalia Petersen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marcus Henricsson
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Dan Ploug Christensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Muhammad Tanweer Khan
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Annika Wahlström
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Per-Olof Bergh
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Valentina Tremaroli
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | | | - Hanns-Ulrich Marschall
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Fredrik Bäckhed
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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3
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Andreoletti M, Lazzaroni C, Petersen N, Segawa S, Leibing A, Schicktanz S, Blasimme A. Optimizing the Aging Brain: The BEAD Study on the Ethics of Dementia Prevention. J Frailty Aging 2023; 12:111-116. [PMID: 36946707 DOI: 10.14283/jfa.2023.6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Dementia has lately undergone a profound reconceptualization. Long conceived of as an unpreventable process of mental deterioration, current evidence shows that it can be prevented in at least one in three cases intervening on a specified set of factors. Issues of justice and equity loom large on the implementation of dementia prevention, from a global health perspective. Our project thus embraces emerging evidence about dementia risk factors and their uneven distribution nationally and globally by specifically focusing on the situated aspects of dementia prevention. The aim of the BEAD study (Optimizing the Aging Brain? Situating Ethical Aspects in Dementia Prevention) is to dissect the ethical and clinical assumptions of this novel understanding of dementia, and to analyze how such new discourse on dementia prevention plays out in three countries: Canada, Germany and Switzerland. This study adopts a multi-perspective, comparative, qualitative approach, combining stakeholder interviews with different kinds of focused ethnographies, elaborating on conceptual, ethical, and social aspects of what we would like to call the "new dementia". By situating the paradigmatic shifts in Alzheimer's and dementia research within current aging cultures and contemporary social policies, we aim to initiate a debate about the often implicit unresolved social, ethical, and political implications and preconditions of the medical understanding and handling of cognitive disorders.
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Affiliation(s)
- M Andreoletti
- Alessandro Blasimme, ETH Zurich, Zurich, Switzerland,
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4
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Offergeld C, Hofauer B, Poxleitner P, Lagrèze W, Schnell O, Petersen N, Lang F, Burkhardt V, Pfeiffer J, Albrecht T. [Traumatology-an interdisciplinary task: exclusively for educational purposes?]. HNO 2023; 71:8-14. [PMID: 36525032 PMCID: PMC9839790 DOI: 10.1007/s00106-022-01255-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2022] [Indexed: 12/23/2022]
Abstract
BACKGROUND Traumatology of the head and neck region is not only a part of otorhinolaryngology, but also has a large overlap with neighboring disciplines of the head and neck region. In Freiburg, an interdisciplinary lecture on "ENT emergencies" was implemented in the 21/22 winter semester. The aim was to provide an even more realistic view on interdisciplinary patient care and to make evident the areas of intersection of four of the major head disciplines (otorhinolaryngology, neurosurgery, ophthalmology, and maxillofacial surgery). MATERIALS AND METHODS A new, special lecture in otorhinolaryngology was implemented as part of the regular online lecture series accompanying the semester. With reference to the clinical care of ENT emergencies, possible overlaps with neighboring disciplines were identified and explained by the discipline representatives or discussed in front of and with the auditorium. At the end of the semester, all participating students (n = 173) were invited to evaluate the seminar using the survey tool "EvaSys" (EvaSys GmbH, Lüneburg, Germany). In total, 78 students participated in the evaluation process. RESULTS The new lecture concept was very well accepted and immediately ranked top among the interdisciplinary lecture titles within the ENT lecture series. The clear communication of the term "interdisciplinarity" in the sense of a complementary clinical cooperation was also very successful and was appreciated accordingly by students during the evaluation process. CONCLUSION Pragmatic presentation of ideal clinical patient care using an interdisciplinary approach is possible within the regular ENT lecture series. This realistic portrayal, beyond any technical and/or professional differences, is of great interest to students and is considered clinically relevant. Thus, interdisciplinary lectures provide a valuable tool to teach the fundamental values of clinical interdisciplinary management for the best possible patient care.
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Affiliation(s)
- C Offergeld
- Univ.-HNO-Klinik, Medizinische Fakultät, Universitätsklinikum Freiburg, Killianstr. 5, 79106, Freiburg, Deutschland.
| | - B Hofauer
- Univ.-HNO-Klinik, Universitätsklinikum TUM München, München, Deutschland
| | - P Poxleitner
- Univ.-Klinik für MKG-Chirurgie, Universitätsklinikum Freiburg, Freiburg, Deutschland
| | - W Lagrèze
- Univ.-Augenklinik, Universitätsklinikum Freiburg, Freiburg, Deutschland
| | - O Schnell
- Neurochirurgische Univ.-Klinik, Universitätsklinikum Freiburg, Freiburg, Deutschland
| | - N Petersen
- Studiendekanat, Universitätsklinikum Freiburg, Freiburg, Deutschland
| | - F Lang
- Univ.-HNO-Klinik, Universitätsklinikum Freiburg, Freiburg, Deutschland
| | - V Burkhardt
- Univ.-HNO-Klinik, Universitätsklinikum Freiburg, Freiburg, Deutschland
| | - J Pfeiffer
- HNO-Praxis am Theater, Freiburg, Deutschland
| | - T Albrecht
- Univ.-HNO-Klinik, Universitätsklinikum Tübingen, Tübingen, Deutschland
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5
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John LM, Petersen N, Gerstenberg MK, Torz L, Pedersen K, Christoffersen BØ, Kuhre RE. Housing-temperature reveals energy intake counter-balances energy expenditure in normal-weight, but not diet-induced obese, male mice. Commun Biol 2022; 5:946. [PMID: 36088386 PMCID: PMC9464191 DOI: 10.1038/s42003-022-03895-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 08/25/2022] [Indexed: 11/16/2022] Open
Abstract
Most metabolic studies on mice are performed at room temperature, although under these conditions mice, unlike humans, spend considerable energy to maintain core temperature. Here, we characterize the impact of housing temperature on energy expenditure (EE), energy homeostasis and plasma concentrations of appetite- and glucoregulatory hormones in normal-weight and diet-induced obese (DIO) C57BL/6J mice fed chow or 45% high-fat-diet, respectively. Mice were housed for 33 days at 22, 25, 27.5, and 30 °C in an indirect-calorimetry-system. We show that energy expenditure increases linearly from 30 °C towards 22 °C and is ~30% higher at 22 °C in both mouse models. In normal-weight mice, food intake counter-balances EE. In contrast, DIO mice do not reduce food intake when EE is lowered. By end of study, mice at 30 °C, therefore, had higher body weight, fat mass and plasma glycerol and triglycerides than mice at 22 °C. Dysregulated counterbalancing in DIO mice may result from increased pleasure-based eating. The impact of ambient housing temperature on the interaction of energy intake, energy expenditure and glycemic control in normal and diet-induced obese mice is examined.
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6
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Xu R, Höß C, Swiercz JM, Brandt DT, Lutz V, Petersen N, Li R, Zhao D, Oleksy A, Creigh-Pulatmen T, Trokter M, Fedorova M, Atzberger A, Strandby RB, Olsen AA, Achiam MP, Matthews D, Huber M, Gröne HJ, Offermanns S, Worzfeld T. A semaphorin-plexin-Rasal1 signaling pathway inhibits gastrin expression and protects against peptic ulcers. Sci Transl Med 2022; 14:eabf1922. [PMID: 35857828 DOI: 10.1126/scitranslmed.abf1922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Peptic ulcer disease is a frequent clinical problem with potentially serious complications such as bleeding or perforation. A decisive factor in the pathogenesis of peptic ulcers is gastric acid, the secretion of which is controlled by the hormone gastrin released from gastric G cells. However, the molecular mechanisms regulating gastrin plasma concentrations are poorly understood. Here, we identified a semaphorin-plexin signaling pathway that operates in gastric G cells to inhibit gastrin expression on a transcriptional level, thereby limiting food-stimulated gastrin release and gastric acid secretion. Using a systematic siRNA screening approach combined with biochemical, cell biology, and in vivo mouse experiments, we found that the RasGAP protein Rasal1 is a central mediator of plexin signal transduction, which suppresses gastrin expression through inactivation of the small GTPase R-Ras. Moreover, we show that Rasal1 is pathophysiologically relevant for the pathogenesis of peptic ulcers induced by nonsteroidal anti-inflammatory drugs (NSAIDs), a main risk factor of peptic ulcers in humans. Last, we show that application of recombinant semaphorin 4D alleviates peptic ulcer disease in mice in vivo, demonstrating that this signaling pathway can be harnessed pharmacologically. This study unravels a mode of G cell regulation that is functionally important in gastric homeostasis and disease.
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Affiliation(s)
- Rui Xu
- Institute of Pharmacology, University of Marburg, Marburg 35043, Germany.,Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim 61231, Germany
| | - Carsten Höß
- Institute of Pharmacology, University of Marburg, Marburg 35043, Germany
| | - Jakub M Swiercz
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim 61231, Germany
| | - Dominique T Brandt
- Institute of Pharmacology, University of Marburg, Marburg 35043, Germany
| | - Veronika Lutz
- Institute for Medical Microbiology and Hospital Hygiene, University of Marburg, Marburg 35043, Germany
| | - Natalia Petersen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Rui Li
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim 61231, Germany
| | - Dandan Zhao
- Institute of Pharmacology, University of Marburg, Marburg 35043, Germany
| | | | | | | | | | - Ann Atzberger
- Flow Cytometry Facility, Max Planck Institute for Heart and Lung Research, Bad Nauheim 61231, Germany
| | - Rune B Strandby
- Department of Surgical Gastroenterology, Rigshospitalet, University of Copenhagen, Copenhagen 2100, Denmark
| | - August A Olsen
- Department of Surgical Gastroenterology, Rigshospitalet, University of Copenhagen, Copenhagen 2100, Denmark
| | - Michael P Achiam
- Department of Surgical Gastroenterology, Rigshospitalet, University of Copenhagen, Copenhagen 2100, Denmark
| | | | - Magdalena Huber
- Institute for Medical Microbiology and Hospital Hygiene, University of Marburg, Marburg 35043, Germany
| | - Hermann-Josef Gröne
- Institute of Pharmacology, University of Marburg, Marburg 35043, Germany.,Medical Faculty, University of Heidelberg, Heidelberg 69120, Germany
| | - Stefan Offermanns
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim 61231, Germany.,Medical Faculty, University of Frankfurt, Frankfurt 60590, Germany
| | - Thomas Worzfeld
- Institute of Pharmacology, University of Marburg, Marburg 35043, Germany.,Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim 61231, Germany
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7
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Petersen N, Greiner TU, Torz L, Bookout A, Gerstenberg MK, Castorena CM, Kuhre RE. Targeting the Gut in Obesity: Signals from the Inner Surface. Metabolites 2022; 12:metabo12010039. [PMID: 35050161 PMCID: PMC8778595 DOI: 10.3390/metabo12010039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 11/13/2021] [Revised: 12/26/2021] [Accepted: 12/31/2021] [Indexed: 12/17/2022] Open
Abstract
Obesity is caused by prolonged energy surplus. Current anti-obesity medications are mostly centralized around the energy input part of the energy balance equation by increasing satiety and reducing appetite. Our gastrointestinal tract is a key organ for regulation of food intake and supplies a tremendous number of circulating signals that modulate the activity of appetite-regulating areas of the brain by either direct interaction or through the vagus nerve. Intestinally derived messengers are manifold and include absorbed nutrients, microbial metabolites, gut hormones and other enterokines, collectively comprising a fine-tuned signalling system to the brain. After a meal, nutrients directly interact with appetite-inhibiting areas of the brain and induce satiety. However, overall feeding behaviour also depends on secretion of gut hormones produced by highly specialized and sensitive enteroendocrine cells. Moreover, circulating microbial metabolites and their interactions with enteroendocrine cells further contribute to the regulation of feeding patterns. Current therapies exploiting the appetite-regulating properties of the gut are based on chemically modified versions of the gut hormone, glucagon-like peptide-1 (GLP-1) or on inhibitors of the primary GLP-1 inactivating enzyme, dipeptidyl peptidase-4 (DPP-4). The effectiveness of these approaches shows that that the gut is a promising target for therapeutic interventions to achieve significant weigh loss. We believe that increasing understanding of the functionality of the intestinal epithelium and new delivery systems will help develop selective and safe gut-based therapeutic strategies for improved obesity treatment in the future. Here, we provide an overview of the major homeostatic appetite-regulating signals generated by the intestinal epithelial cells and how these signals may be harnessed to treat obesity by pharmacological means.
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Affiliation(s)
- Natalia Petersen
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk A/S, Novo Park 1, 2670 Måløv, Denmark; (L.T.); (M.K.G.); (R.E.K.)
- Correspondence:
| | - Thomas U. Greiner
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, 405 30 Gothenburg, Sweden;
| | - Lola Torz
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk A/S, Novo Park 1, 2670 Måløv, Denmark; (L.T.); (M.K.G.); (R.E.K.)
- Department of Veterinary and Animal Science, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Angie Bookout
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk Research Center, Seattle, WA 98109, USA; (A.B.); (C.M.C.)
| | - Marina Kjærgaard Gerstenberg
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk A/S, Novo Park 1, 2670 Måløv, Denmark; (L.T.); (M.K.G.); (R.E.K.)
| | - Carlos M. Castorena
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk Research Center, Seattle, WA 98109, USA; (A.B.); (C.M.C.)
| | - Rune Ehrenreich Kuhre
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk A/S, Novo Park 1, 2670 Måløv, Denmark; (L.T.); (M.K.G.); (R.E.K.)
- Department of Veterinary and Animal Science, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
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8
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Grunddal KV, Diep TA, Petersen N, Tough IR, Skov LJ, Liu L, Buijink JA, Mende F, Jin C, Jepsen SL, Sørensen LME, Achiam MP, Strandby RB, Bach A, Hartmann B, Frimurer TM, Hjorth SA, Bouvier M, Cox H, Holst B. Selective release of gastrointestinal hormones induced by an orally active GPR39 agonist. Mol Metab 2021; 49:101207. [PMID: 33711555 PMCID: PMC8042403 DOI: 10.1016/j.molmet.2021.101207] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 03/03/2021] [Accepted: 03/04/2021] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVES Obesity is a complex disease associated with a high risk of comorbidities. Gastric bypass surgery, an invasive procedure with low patient eligibility, is currently the most effective intervention that achieves sustained weight loss. This beneficial effect is attributed to alterations in gut hormone signaling. An attractive alternative is to pharmacologically mimic the effects of bariatric surgery by targeting several gut hormonal axes. The G protein-coupled receptor 39 (GPR39) expressed in the gastrointestinal tract has been shown to mediate ghrelin signaling and control appetite, food intake, and energy homeostasis, but the broader effect on gut hormones is largely unknown. A potent and efficacious GPR39 agonist (Cpd1324) was recently discovered, but the in vivo function was not addressed. Herein we studied the efficacy of the GPR39 agonist, Cpd1324, on metabolism and gut hormone secretion. METHODS Body weight, food intake, and energy expenditure in GPR39 agonist-treated mice and GPR39 KO mice were studied in calorimetric cages. Plasma ghrelin, glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) levels were measured. Organoids generated from murine and human small intestine and mouse colon were used to study GLP-1 and PYY release. Upon GPR39 agonist administration, dynamic changes in intracellular GLP-1 content were studied via immunostaining and changes in ion transport across colonic mucosa were monitored in Ussing chambers. The G protein activation underlying GPR39-mediated selective release of gut hormones was studied using bioluminescence resonance energy transfer biosensors. RESULTS The GPR39 KO mice displayed a significantly increased food intake without corresponding increases in respiratory exchange ratios or energy expenditure. Oral administration of a GPR39 agonist induced an acute decrease in food intake and subsequent weight loss in high-fat diet (HFD)-fed mice without affecting their energy expenditure. The tool compound, Cpd1324, increased GLP-1 secretion in the mice as well as in mouse and human intestinal organoids, but not in GPR39 KO mouse organoids. In contrast, the GPR39 agonist had no effect on PYY or GIP secretion. Transepithelial ion transport was acutely affected by GPR39 agonism in a GLP-1- and calcitonin gene-related peptide (CGRP)-dependent manner. Analysis of Cpd1324 signaling properties showed activation of Gαq and Gαi/o signaling pathways in L cells, but not Gαs signaling. CONCLUSIONS The GPR39 agonist described in this study can potentially be used by oral administration as a weight-lowering agent due to its stimulatory effect on GLP-1 secretion, which is most likely mediated through a unique activation of Gα subunits. Thus, GPR39 agonism may represent a novel approach to effectively treat obesity through selective modulation of gastrointestinal hormonal axes.
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Affiliation(s)
- Kaare V Grunddal
- Department of Medicine, University of California San Diego, La Jolla, CA 92037, USA
| | - Thi A Diep
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Natalia Petersen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Iain R Tough
- Wolfson Center for Age-Related Diseases, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, SE1 1UL, UK
| | - Louise J Skov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Lingzhi Liu
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Jesse A Buijink
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Franziska Mende
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Chunyu Jin
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Sara L Jepsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Louis M E Sørensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Michael P Achiam
- Department of Surgical Gastroenterology, Rigshospitalet, University of Copenhagen, Denmark
| | - Rune B Strandby
- Department of Surgical Gastroenterology, Rigshospitalet, University of Copenhagen, Denmark
| | - Anders Bach
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Bolette Hartmann
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Thomas M Frimurer
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Siv A Hjorth
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Michel Bouvier
- Department of Biochemistry and Molecular Medicine, Institute for Research in Immunology and Cancer, Molecular Pharmacology Research Unit, University of Montréal, Marcelle-Coutu Bureau Pavilion 1306-3, Montréal, QC H3T 1J4, Canada
| | - Helen Cox
- Wolfson Center for Age-Related Diseases, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, SE1 1UL, UK
| | - Birgitte Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark.
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9
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Kuhre RE, Deacon CF, Holst JJ, Petersen N. What Is an L-Cell and How Do We Study the Secretory Mechanisms of the L-Cell? Front Endocrinol (Lausanne) 2021; 12:694284. [PMID: 34168620 PMCID: PMC8218725 DOI: 10.3389/fendo.2021.694284] [Citation(s) in RCA: 10] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 05/11/2021] [Indexed: 12/14/2022] Open
Abstract
Synthetic glucagon-like peptide-1 (GLP-1) analogues are effective anti-obesity and anti-diabetes drugs. The beneficial actions of GLP-1 go far beyond insulin secretion and appetite, and include cardiovascular benefits and possibly also beneficial effects in neurodegenerative diseases. Considerable reserves of GLP-1 are stored in intestinal endocrine cells that potentially might be mobilized by pharmacological means to improve the body's metabolic state. In recognition of this, the interest in understanding basic L-cell physiology and the mechanisms controlling GLP-1 secretion, has increased considerably. With a view to home in on what an L-cell is, we here present an overview of available data on L-cell development, L-cell peptide expression profiles, peptide production and secretory patterns of L-cells from different parts of the gut. We conclude that L-cells differ markedly depending on their anatomical location, and that the traditional definition of L-cells as a homogeneous population of cells that only produce GLP-1, GLP-2, glicentin and oxyntomodulin is no longer tenable. We suggest to sub-classify L-cells based on their differential peptide contents as well as their differential expression of nutrient sensors, which ultimately determine the secretory responses to different stimuli. A second purpose of this review is to describe and discuss the most frequently used experimental models for functional L-cell studies, highlighting their benefits and limitations. We conclude that no experimental model is perfect and that a comprehensive understanding must be built on results from a combination of models.
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Affiliation(s)
- Rune E. Kuhre
- Department of Obesity Pharmacology, Novo Nordisk, Måløv, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- *Correspondence: Rune E. Kuhre, ;
| | - Carolyn F. Deacon
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
- School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
| | - Jens J. Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
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10
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Konrads C, Petersen N, Histing T, Döbele S. Arthroscopic Minimal Invasive Treatment of Posterolateral Tibial Plateau Impression Fractures. Acta Chir Orthop Traumatol Cech 2021; 88:382-385. [PMID: 34738899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Posterolateral fractures of the tibial plateau are difficult to address. Malunion can lead to early posttraumatic arthritis of the knee due to instability and elevated joint reaction forces. Arthroscopically assisted percutaneous reduction facilitates visualization and avoids open approaches either directly from posterolateral or from lateral with optional extension via a lateral epicondylus osteotomy. We describe and illustrate a minimal invasive technique using an arthroscopic posterolateral viewing portal. Using this technique, we demonstrated very good clinical outcome with excellent patient satisfaction. Key words: Schatzker, tibia head fracture, knee arthroscopy, multiligamentary injury.
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Affiliation(s)
- C Konrads
- Department for Trauma and Reconstructive Surgery, BG Klinik, University of Tübingen, Tübingen, Germany
| | - N Petersen
- Department for Trauma and Reconstructive Surgery, BG Klinik, University of Tübingen, Tübingen, Germany
| | - T Histing
- Department for Trauma and Reconstructive Surgery, BG Klinik, University of Tübingen, Tübingen, Germany
| | - S Döbele
- Department for Trauma and Reconstructive Surgery, BG Klinik, University of Tübingen, Tübingen, Germany
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11
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Petersen N, Torz L, Jensen KHR, Hjortø GM, Spiess K, Rosenkilde MM. Three-Dimensional Explant Platform for Studies on Choroid Plexus Epithelium. Front Cell Neurosci 2020; 14:108. [PMID: 32431599 PMCID: PMC7214744 DOI: 10.3389/fncel.2020.00108] [Citation(s) in RCA: 3] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 04/08/2020] [Indexed: 12/12/2022] Open
Abstract
The choroid plexus (CP) plays a major role in controlling the entry of substances and immune cells into the brain as it forms the blood-cerebrospinal fluid barrier (BCSFB) in the brain ventricles. Dysregulated immune cell trafficking through the epithelial cell (EC) layer of CP is central for the pathogenesis of infectious diseases in the brain and many neurodegenerative disorders. In vitro studies elucidating the function of the CP have so far been limited to the monolayer culture of CP ECs. To mimic immune cell migration across the CP barrier, a three-dimensional model would be advantageous. Here, we present an in vitro platform for studies of the immune cell trafficking based on CP explants/organoids. The explants were generated from fragments of mouse CPs in Matrigel, where the cells formed luminal spaces and could be maintained in culture for at least 8 weeks. We demonstrate expression of the major CP markers in the explants, including transthyretin and aquaporin 1 as well as ZO1 and ICAM-1, indicating a capacity for secretion of cerebrospinal fluid (CSF) and presence of tight junctions. CP explants displayed CP-like cell polarization and formed an intact EC barrier. We also show that the expression of transthyretin, transferrin, occludin and other genes associated with various functions of CP was maintained in the explants at similar levels as in native CP. By using dendritic cells and neutrophils, we show that the migration activity of immune cells and their interactions with CP epithelium can be monitored by microscopy. Thereby, the three-dimensional CP explant model can be used to study the cellular and molecular mechanisms mediating immune cell migration through CP epithelium and other functions of choroid EC. We propose this platform can potentially be used in the search for therapeutic targets and intervention strategies to improve control of (drug) substances and (immune) cell entry into the central nervous system.
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Affiliation(s)
- Natalia Petersen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lola Torz
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kristian H Reveles Jensen
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gertrud Malene Hjortø
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Katja Spiess
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mette Marie Rosenkilde
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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12
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Torz LJ, Osborne-Lawrence S, Rodriguez J, He Z, Cornejo MP, Mustafá ER, Jin C, Petersen N, Hedegaard MA, Nybo M, Damonte VM, Metzger NP, Mani BK, Williams KW, Raingo J, Perello M, Holst B, Zigman JM. Metabolic insights from a GHSR-A203E mutant mouse model. Mol Metab 2020; 39:101004. [PMID: 32339772 PMCID: PMC7242877 DOI: 10.1016/j.molmet.2020.101004] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 04/13/2020] [Accepted: 04/16/2020] [Indexed: 02/02/2023] Open
Abstract
Objective Binding of ghrelin to its receptor, growth hormone secretagogue receptor (GHSR), stimulates GH release, induces eating, and increases blood glucose. These processes may also be influenced by constitutive (ghrelin-independent) GHSR activity, as suggested by findings in short people with naturally occurring GHSR-A204E mutations and reduced food intake and blood glucose in rodents administered GHSR inverse agonists, both of which impair constitutive GHSR activity. In this study, we aimed to more fully determine the physiologic relevance of constitutive GHSR activity. Methods We generated mice with a GHSR mutation that replaces alanine at position 203 with glutamate (GHSR-A203E), which corresponds to the previously described human GHSR-A204E mutation, and used them to conduct ex vivo neuronal electrophysiology and in vivo metabolic assessments. We also measured signaling within COS-7 and HEK293T cells transfected with wild-type GHSR (GHSR-WT) or GHSR-A203E constructs. Results In COS-7 cells, GHSR-A203E resulted in lower baseline IP3 accumulation than GHSR-WT; ghrelin-induced IP3 accumulation was observed in both constructs. In HEK293T cells co-transfected with voltage-gated CaV2.2 calcium channel complex, GHSR-A203E had no effect on basal CaV2.2 current density while GHSR-WT did; both GHSR-A203E and GHSR-WT inhibited CaV2.2 current in the presence of ghrelin. In cultured hypothalamic neurons from GHSR-A203E and GHSR-deficient mice, native calcium currents were greater than those in neurons from wild-type mice; ghrelin inhibited calcium currents in cultured hypothalamic neurons from both GHSR-A203E and wild-type mice. In brain slices, resting membrane potentials of arcuate NPY neurons from GHSR-A203E mice were hyperpolarized compared to those from wild-type mice; the same percentage of arcuate NPY neurons from GHSR-A203E and wild-type mice depolarized upon ghrelin exposure. The GHSR-A203E mutation did not significantly affect body weight, body length, or femur length in the first ∼6 months of life, yet these parameters were lower in GHSR-A203E mice after 1 year of age. During a 7-d 60% caloric restriction regimen, GHSR-A203E mice lacked the usual marked rise in plasma GH and demonstrated an exaggerated drop in blood glucose. Administered ghrelin also exhibited reduced orexigenic and GH secretagogue efficacies in GHSR-A203E mice. Conclusions Our data suggest that the A203E mutation ablates constitutive GHSR activity and that constitutive GHSR activity contributes to the native depolarizing conductance of GHSR-expressing arcuate NPY neurons. Although the A203E mutation does not block ghrelin-evoked signaling as assessed using in vitro and ex vivo models, GHSR-A203E mice lack the usual acute food intake response to administered ghrelin in vivo. The GHSR-A203E mutation also blunts GH release, and in aged mice leads to reduced body length and femur length, which are consistent with the short stature of human carriers of the GHSR-A204E mutation. We generated mice with a GHSR mutation replacing Ala at position 203 with Glu. The A203E mutation ablates constitutive GHSR activity & hyperpolarizes NPY neurons. GHSR-A203E mice lack the usual orexigenic response to administered ghrelin. The GHSR-A203E mutation blunts GH release and causes reduced body length. This finding is consistent with short stature in human carriers of the GHSR-A204E mutation.
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Affiliation(s)
- Lola J Torz
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Sherri Osborne-Lawrence
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Juan Rodriguez
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Zhenyan He
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | | | - Emilio Román Mustafá
- Laboratory of Electrophysiology of the Multidisciplinary Institute of Cell Biology [Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA)], La Plata, Buenos Aires, Argentina
| | - Chunyu Jin
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Natalia Petersen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten A Hedegaard
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Maja Nybo
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Valentina Martínez Damonte
- Laboratory of Electrophysiology of the Multidisciplinary Institute of Cell Biology [Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA)], La Plata, Buenos Aires, Argentina
| | - Nathan P Metzger
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Bharath K Mani
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Kevin W Williams
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Jesica Raingo
- Laboratory of Electrophysiology of the Multidisciplinary Institute of Cell Biology [Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA)], La Plata, Buenos Aires, Argentina
| | - Mario Perello
- Laboratory of Neurophysiology, La Plata, Buenos Aires, Argentina
| | - Birgitte Holst
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.
| | - Jeffrey M Zigman
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA.
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13
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Lund ML, Sorrentino G, Egerod KL, Kroone C, Mortensen B, Knop FK, Reimann F, Gribble FM, Drucker DJ, de Koning EJP, Schoonjans K, Bäckhed F, Schwartz TW, Petersen N. L-Cell Differentiation Is Induced by Bile Acids Through GPBAR1 and Paracrine GLP-1 and Serotonin Signaling. Diabetes 2020; 69:614-623. [PMID: 32041793 PMCID: PMC7224989 DOI: 10.2337/db19-0764] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 01/22/2020] [Indexed: 12/20/2022]
Abstract
Glucagon-like peptide 1 (GLP-1) mimetics are effective drugs for treatment of type 2 diabetes, and there is consequently extensive interest in increasing endogenous GLP-1 secretion and L-cell abundance. Here we identify G-protein-coupled bile acid receptor 1 (GPBAR1) as a selective regulator of intestinal L-cell differentiation. Lithocholic acid and the synthetic GPBAR1 agonist, L3740, selectively increased L-cell density in mouse and human intestinal organoids and elevated GLP-1 secretory capacity. L3740 induced expression of Gcg and transcription factors Ngn3 and NeuroD1 L3740 also increased the L-cell number and GLP-1 levels and improved glucose tolerance in vivo. Further mechanistic examination revealed that the effect of L3740 on L cells required intact GLP-1 receptor and serotonin 5-hydroxytryptamine receptor 4 (5-HT4) signaling. Importantly, serotonin signaling through 5-HT4 mimicked the effects of L3740, acting downstream of GLP-1. Thus, GPBAR1 agonists and other powerful GLP-1 secretagogues facilitate L-cell differentiation through a paracrine GLP-1-dependent and serotonin-mediated mechanism.
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Affiliation(s)
- Mari Lilith Lund
- Novo Nordisk Foundation Center for Basic Metabolic Research Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Giovanni Sorrentino
- Laboratory of Metabolic Signaling, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Kristoffer Lihme Egerod
- Novo Nordisk Foundation Center for Basic Metabolic Research Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chantal Kroone
- Department of Thrombosis and Hemostasis, Leiden University Medical Centre, Leiden, the Netherlands
| | - Brynjulf Mortensen
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Filip Krag Knop
- Novo Nordisk Foundation Center for Basic Metabolic Research Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
| | - Frank Reimann
- Institute of Metabolic Science and Medical Research Council Metabolic Diseases Unit, University of Cambridge, Addenbrooke's Hospital, Cambridge, U.K
| | - Fiona M Gribble
- Institute of Metabolic Science and Medical Research Council Metabolic Diseases Unit, University of Cambridge, Addenbrooke's Hospital, Cambridge, U.K
| | - Daniel J Drucker
- Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Eelco J P de Koning
- Department of Medicine, Leiden University Medical Centre, Leiden, the Netherlands
- Hubrecht Institute/Koninklijke Nederlandse Akademie van Wetenschappen (KNAW) and University Medical Center Utrecht, Utrecht, the Netherlands
| | - Kristina Schoonjans
- Laboratory of Metabolic Signaling, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Fredrik Bäckhed
- Novo Nordisk Foundation Center for Basic Metabolic Research Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Molecular and Clinical Medicine at Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Thue W Schwartz
- Novo Nordisk Foundation Center for Basic Metabolic Research Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Natalia Petersen
- Novo Nordisk Foundation Center for Basic Metabolic Research Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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14
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Grevengoed TJ, Trammell SAJ, McKinney MK, Petersen N, Cardone RL, Svenningsen JS, Ogasawara D, Nexøe-Larsen CC, Knop FK, Schwartz TW, Kibbey RG, Cravatt BF, Gillum MP. N-acyl taurines are endogenous lipid messengers that improve glucose homeostasis. Proc Natl Acad Sci U S A 2019; 116:24770-24778. [PMID: 31740614 PMCID: PMC6900532 DOI: 10.1073/pnas.1916288116] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Fatty acid amide hydrolase (FAAH) degrades 2 major classes of bioactive fatty acid amides, the N-acylethanolamines (NAEs) and N-acyl taurines (NATs), in central and peripheral tissues. A functional polymorphism in the human FAAH gene is linked to obesity and mice lacking FAAH show altered metabolic states, but whether these phenotypes are caused by elevations in NAEs or NATs is unknown. To overcome the problem of concurrent elevation of NAEs and NATs caused by genetic or pharmacological disruption of FAAH in vivo, we developed an engineered mouse model harboring a single-amino acid substitution in FAAH (S268D) that selectively disrupts NAT, but not NAE, hydrolytic activity. The FAAH-S268D mice accordingly show substantial elevations in NATs without alterations in NAE content, a unique metabolic profile that correlates with heightened insulin sensitivity and GLP-1 secretion. We also show that N-oleoyl taurine (C18:1 NAT), the most abundant NAT in human plasma, decreases food intake, improves glucose tolerance, and stimulates GPR119-dependent GLP-1 and glucagon secretion in mice. Together, these data suggest that NATs act as a class of lipid messengers that improve postprandial glucose regulation and may have potential as investigational metabolites to modify metabolic disease.
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Affiliation(s)
- Trisha J Grevengoed
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Samuel A J Trammell
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Michele K McKinney
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037
| | - Natalia Petersen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Rebecca L Cardone
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06519
| | - Jens S Svenningsen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Daisuke Ogasawara
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037
| | - Christina C Nexøe-Larsen
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, 2900 Hellerup, Denmark
| | - Filip K Knop
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, 2900 Hellerup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Clinical Metabolic Physiology, Steno Diabetes Center Copenhagen, Gentofte, 2820 Hellerup, Denmark
| | - Thue W Schwartz
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Richard G Kibbey
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06519
| | - Benjamin F Cravatt
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037;
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037
| | - Matthew P Gillum
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark;
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15
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Piccand J, Vagne C, Blot F, Meunier A, Beucher A, Strasser P, Lund ML, Ghimire S, Nivlet L, Lapp C, Petersen N, Engelstoft MS, Thibault-Carpentier C, Keime C, Correa SJ, Schreiber V, Molina N, Schwartz TW, De Arcangelis A, Gradwohl G. Rfx6 promotes the differentiation of peptide-secreting enteroendocrine cells while repressing genetic programs controlling serotonin production. Mol Metab 2019; 29:24-39. [PMID: 31668390 PMCID: PMC6728766 DOI: 10.1016/j.molmet.2019.08.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [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: 07/16/2019] [Revised: 08/01/2019] [Accepted: 08/10/2019] [Indexed: 12/16/2022] Open
Abstract
Objective Enteroendocrine cells (EECs) of the gastro-intestinal tract sense gut luminal factors and release peptide hormones or serotonin (5-HT) to coordinate energy uptake and storage. Our goal is to decipher the gene regulatory networks controlling EECs specification from enteroendocrine progenitors. In this context, we studied the role of the transcription factor Rfx6 which had been identified as the cause of Mitchell–Riley syndrome, characterized by neonatal diabetes and congenital malabsorptive diarrhea. We previously reported that Rfx6 was essential for pancreatic beta cell development and function; however, the role of Rfx6 in EECs differentiation remained to be elucidated. Methods We examined the molecular, cellular, and metabolic consequences of constitutive and conditional deletion of Rfx6 in the embryonic and adult mouse intestine. We performed single cell and bulk RNA-Seq to characterize EECs diversity and identify Rfx6-regulated genes. Results Rfx6 is expressed in the gut endoderm; later, it is turned on in, and restricted to, enteroendocrine progenitors and persists in hormone-positive EECs. In the embryonic intestine, the constitutive lack of Rfx6 leads to gastric heterotopia, suggesting a role in the maintenance of intestinal identity. In the absence of intestinal Rfx6, EECs differentiation is severely impaired both in the embryo and adult. However, the number of serotonin-producing enterochromaffin cells and mucosal 5-HT content are increased. Concomitantly, Neurog3-positive enteroendocrine progenitors accumulate. Combined analysis of single-cell and bulk RNA-Seq data revealed that enteroendocrine progenitors differentiate in two main cell trajectories, the enterochromaffin (EC) cells and the Peptidergic Enteroendocrine (PE) cells, the differentiation programs of which are differentially regulated by Rfx6. Rfx6 operates upstream of Arx, Pax6 and Isl1 to trigger the differentiation of peptidergic EECs such as GIP-, GLP-1-, or CCK-secreting cells. On the contrary, Rfx6 represses Lmx1a and Tph1, two genes essential for serotonin biosynthesis. Finally, we identified transcriptional changes uncovering adaptive responses to the prolonged lack of enteroendocrine hormones and leading to malabsorption and lower food efficiency ratio in Rfx6-deficient mouse intestine. Conclusion These studies identify Rfx6 as an essential transcriptional regulator of EECs specification and shed light on the molecular mechanisms of intestinal failures in human RFX6-deficiencies such as Mitchell–Riley syndrome. The lack of Rfx6 impairs the differentiation of peptide-producing enteroendocrine cells. The number of 5-HT-expressing-cells is increased in Rfx6-deficient intestine. Intestinal inactivation of Rfx6 leads to lipid malabsorption and decreased food efficiency.
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Affiliation(s)
- Julie Piccand
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Constance Vagne
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Florence Blot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Aline Meunier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Anthony Beucher
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Perrine Strasser
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Mari L Lund
- Centre for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health Science, University of Copenhagen, Denmark
| | - Sabitri Ghimire
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Laure Nivlet
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Céline Lapp
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Natalia Petersen
- Centre for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health Science, University of Copenhagen, Denmark
| | - Maja S Engelstoft
- Centre for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health Science, University of Copenhagen, Denmark
| | - Christelle Thibault-Carpentier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Céline Keime
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Sara Jimenez Correa
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Valérie Schreiber
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Nacho Molina
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Thue W Schwartz
- Centre for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health Science, University of Copenhagen, Denmark
| | - Adèle De Arcangelis
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France.
| | - Gérard Gradwohl
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France.
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16
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Petersen N, Knudsen AD, Mocroft A, Kirkegaard-Klitbo D, Arici E, Lundgren J, Benfield T, Oturai P, Nordestgaard BG, Feldt-Rasmussen B, Nielsen SD, Ryom L. Prevalence of impaired renal function in virologically suppressed people living with HIV compared with controls: the Copenhagen Comorbidity in HIV Infection (COCOMO) study. HIV Med 2019; 20:639-647. [PMID: 31359592 DOI: 10.1111/hiv.12778] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2019] [Indexed: 12/19/2022]
Abstract
OBJECTIVES While renal impairment is reported more frequently in people living with HIV (PLWH) than in the general population, the PLWH samples in previous studies have generally been dominated by those at high renal risk. METHODS Caucasian PLWH who were virologically suppressed on antiretroviral treatment and did not have injecting drug use or hepatitis C were recruited from the Copenhagen Comorbidity in HIV Infection (COCOMO) study. Sex- and age-matched controls were recruited 1:4 from the Copenhagen General Population Study up to November 2016. We defined renal impairment as one measurement of estimated glomerular filtration rate ≤ 60 mL/min/1.73 m2 , and assessed associated factors using adjusted logistic regression models. The impact of HIV-related factors was explored in a subanalysis. RESULTS Among 598 PLWH and 2598 controls, the prevalence of renal impairment was 3.7% [95% confidence interval (CI) 2.3-5.5%] and 1.7% (95% CI 1.2-2.2%; P = 0.0014), respectively. After adjustment, HIV status was independently associated with renal impairment [odds ratio (OR) 3.4; 95% CI 1.8-6.3]. In addition, older age [OR 5.4 (95% CI 3.9-7.5) per 10 years], female sex [OR 5.0 (95% CI 2.6-9.8)] and diabetes [OR 2.9 (95% CI 1.3-6.7)] were strongly associated with renal impairment. The association between HIV status and renal impairment became stronger with older age (P = 0.02 for interaction). Current and nadir CD4 counts, duration of HIV infection and previous AIDS-defining diagnosis were not associated with renal impairment among virologically suppressed PLWH. CONCLUSIONS The prevalence of renal impairment is low among low-risk virologically suppressed Caucasian PLWH, but remains significantly higher than in controls. Renal impairment therefore remains a concern in all PLWH and requires ongoing attention.
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Affiliation(s)
- N Petersen
- Department of Infectious Diseases, Viro-immunology Research Unit, Rigshospitalet, Copenhagen, Denmark
| | - A D Knudsen
- Department of Infectious Diseases, Viro-immunology Research Unit, Rigshospitalet, Copenhagen, Denmark
| | - A Mocroft
- Centre for Clinical Research, Epidemiology, Modelling and Evaluation (CREME), Institute for Global Health, UCL, London, UK
| | | | - E Arici
- Department of Infectious Diseases, Viro-immunology Research Unit, Rigshospitalet, Copenhagen, Denmark
| | - J Lundgren
- Department of Infectious Diseases, CHIP, Center of Excellence for Health, Immunity and Infections, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - T Benfield
- Department of Infectious Diseases, Hvidovre Hospital, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - P Oturai
- Department of Clinical Physiology, Nuclear Medicine and PET, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - B G Nordestgaard
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,The Copenhagen General Population Study and Department of Clinical Biochemistry, Herlev and Gentofte Hospital, Copenhagen, Denmark
| | - B Feldt-Rasmussen
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Nephrology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - S D Nielsen
- Department of Infectious Diseases, Viro-immunology Research Unit, Rigshospitalet, Copenhagen, Denmark
| | - L Ryom
- Department of Infectious Diseases, CHIP, Center of Excellence for Health, Immunity and Infections, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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17
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Rudenko O, Shang J, Munk A, Ekberg JP, Petersen N, Engelstoft MS, Egerod KL, Hjorth SA, Wu M, Feng Y, Zhou YP, Mokrosinski J, Thams P, Reimann F, Gribble F, Rehfeld JF, Holst JJ, Treebak JT, Howard AD, Schwartz TW. The aromatic amino acid sensor GPR142 controls metabolism through balanced regulation of pancreatic and gut hormones. Mol Metab 2019; 19:49-64. [PMID: 30472415 PMCID: PMC6323244 DOI: 10.1016/j.molmet.2018.10.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 10/29/2018] [Accepted: 10/31/2018] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES GPR142, which is highly expressed in pancreatic islets, has recently been deorphanized as a receptor for aromatic amino acids; however, its physiological role and pharmacological potential is unclear. METHODS AND RESULTS We find that GPR142 is expressed not only in β- but also in α-cells of the islets as well as in enteroendocrine cells, and we confirm that GPR142 is a highly selective sensor of essential aromatic amino acids, in particular Trp and oligopeptides with N-terminal Trp. GPR142 knock-out mice displayed a very limited metabolic phenotype but demonstrated that L-Trp induced secretion of pancreatic and gut hormones is mediated through GPR142 but that the receptor is not required for protein-induced hormone secretion. A synthetic GPR142 agonist stimulated insulin and glucagon as well as GIP, CCK, and GLP-1 secretion. In particular, GIP secretion was sensitive to oral administration of the GPR142 agonist an effect which in contrast to the other hormones was blocked by protein load. Oral administration of the GPR142 agonist increased [3H]-2-deoxyglucose uptake in muscle and fat depots mediated through insulin action while it lowered liver glycogen conceivably mediated through glucagon, and, consequently, it did not lower total blood glucose. Nevertheless, acute administration of the GPR142 agonist strongly improved oral glucose tolerance in both lean and obese mice as well as Zucker fatty rat. Six weeks in-feed chronic treatment with the GPR142 agonist did not affect body weight in DIO mice, but increased energy expenditure and carbohydrate utilization, lowered basal glucose, and improved insulin sensitivity. CONCLUSIONS GPR142 functions as a sensor of aromatic amino acids, controlling GIP but also CCK and GLP-1 as well as insulin and glucagon in the pancreas. GPR142 agonists could have novel interesting potential in modifying metabolism through a balanced action of gut hormones as well as both insulin and glucagon.
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Affiliation(s)
- Olga Rudenko
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark; Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jin Shang
- Merck Research Laboratories, 2015 Galloping Hills Road, Kenilworth, NJ, USA
| | - Alexander Munk
- Section of Integrative Physiology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Jeppe P Ekberg
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Natalia Petersen
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Maja S Engelstoft
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark; Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kristoffer L Egerod
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark; Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Siv A Hjorth
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Margaret Wu
- Merck Research Laboratories, 2015 Galloping Hills Road, Kenilworth, NJ, USA
| | - Yue Feng
- Merck Research Laboratories, 2015 Galloping Hills Road, Kenilworth, NJ, USA
| | - Yun-Ping Zhou
- Merck Research Laboratories, 2015 Galloping Hills Road, Kenilworth, NJ, USA
| | - Jacek Mokrosinski
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark; Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peter Thams
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Frank Reimann
- Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, United Kingdom
| | - Fiona Gribble
- Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, United Kingdom
| | - Jens F Rehfeld
- Department of Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark
| | - Jens J Holst
- Section of Translational Metabolic Physiology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Jonas T Treebak
- Section of Integrative Physiology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Andrew D Howard
- Merck Research Laboratories, 2015 Galloping Hills Road, Kenilworth, NJ, USA
| | - Thue W Schwartz
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark; Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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18
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Petersen N, Frimurer TM, Terndrup Pedersen M, Egerod KL, Wewer Albrechtsen NJ, Holst JJ, Grapin-Botton A, Jensen KB, Schwartz TW. Inhibiting RHOA Signaling in Mice Increases Glucose Tolerance and Numbers of Enteroendocrine and Other Secretory Cells in the Intestine. Gastroenterology 2018; 155:1164-1176.e2. [PMID: 29935151 DOI: 10.1053/j.gastro.2018.06.039] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [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: 06/15/2017] [Revised: 06/13/2018] [Accepted: 06/14/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Glucagon-like peptide 1 (GLP1) is produced by L cells in the intestine, and agonists of the GLP1 receptor are effective in the treatment of diabetes. Levels of GLP1 increase with numbers of L cells. Therefore, agents that increase numbers of L cell might be developed for treatment of diabetes. Ras homologue family member A (RhoA) signaling through Rho-associated coiled-coil-containing protein kinases 1 and 2 (ROCK1 and ROCK2) controls cell differentiation, but it is not clear whether this pathway regulates enteroendocrine differentiation in the intestinal epithelium. We investigated the effects of Y-27632, an inhibitor of ROCK1 and ROCK2, on L-cell differentiation. METHODS We collected intestinal tissues from GLU-Venus, GPR41-RFP, and Neurog3-RFP mice, in which the endocrine lineage is fluorescently labeled, for in vitro culture and histologic analysis. Small intestine organoids derived from these mice were cultured with Y-27632 and we measured percentages of L cells, expression of intestinal cell-specific markers, and secretion of GLP1 in medium. Mice were fed a normal chow or a high-fat diet and given Y-27632 or saline (control) and blood samples were collected for measurement of GLP1, insulin, and glucose. RESULTS Incubation of intestinal organoids with Y-27632 increased numbers of L cells and secretion of GLP1. These increases were associated with upregulated expression of genes encoding intestinal hormones, neurogenin 3, neurogenic differentiation factor 1, forkhead box A1 and A2, and additional markers of secretory cells. Mice fed the normal chow diet and given Y-27632 had increased numbers of L cells in intestinal tissues, increased plasma levels of GLP1 and insulin, and lower blood levels of glucose compared with mice fed the normal chow diet and given saline. In mice with insulin resistance induced by the high-fat diet, administration of Y-27632 increased secretion of GLP1 and glucose tolerance compared with administration of saline. CONCLUSIONS In mouse intestinal organoids, an inhibitor of RhoA signaling increased the differentiation of the secretory lineage and the development of enteroendocrine cells. Inhibitors of RhoA signaling or other strategies to increase numbers of L cells might be developed for treatment of patients with type 2 diabetes or for increasing glucose tolerance.
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Affiliation(s)
- Natalia Petersen
- Section of Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Thomas M Frimurer
- Section of Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Kristoffer L Egerod
- Section of Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences and the Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Translational Metabolic Physiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences and the Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Translational Metabolic Physiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anne Grapin-Botton
- Novo Nordisk Foundation Center for Stem Cell Research, Faculty of Medical and Health, University of Copenhagen, Copenhagen, Denmark
| | - Kim B Jensen
- Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Stem Cell Research, Faculty of Medical and Health, University of Copenhagen, Copenhagen, Denmark
| | - Thue W Schwartz
- Section of Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
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19
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Egerod KL, Petersen N, Timshel PN, Rekling JC, Wang Y, Liu Q, Schwartz TW, Gautron L. Profiling of G protein-coupled receptors in vagal afferents reveals novel gut-to-brain sensing mechanisms. Mol Metab 2018; 12:62-75. [PMID: 29673577 PMCID: PMC6001940 DOI: 10.1016/j.molmet.2018.03.016] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [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: 02/27/2018] [Revised: 03/24/2018] [Accepted: 03/29/2018] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES G protein-coupled receptors (GPCRs) act as transmembrane molecular sensors of neurotransmitters, hormones, nutrients, and metabolites. Because unmyelinated vagal afferents richly innervate the gastrointestinal mucosa, gut-derived molecules may directly modulate the activity of vagal afferents through GPCRs. However, the types of GPCRs expressed in vagal afferents are largely unknown. Here, we determined the expression profile of all GPCRs expressed in vagal afferents of the mouse, with a special emphasis on those innervating the gastrointestinal tract. METHODS Using a combination of high-throughput quantitative PCR, RNA sequencing, and in situ hybridization, we systematically quantified GPCRs expressed in vagal unmyelinated Nav1.8-expressing afferents. RESULTS GPCRs for gut hormones that were the most enriched in Nav1.8-expressing vagal unmyelinated afferents included NTSR1, NPY2R, CCK1R, and to a lesser extent, GLP1R, but not GHSR and GIPR. Interestingly, both GLP1R and NPY2R were coexpressed with CCK1R. In contrast, NTSR1 was coexpressed with GPR65, a marker preferentially enriched in intestinal mucosal afferents. Only few microbiome-derived metabolite sensors such as GPR35 and, to a lesser extent, GPR119 and CaSR were identified in the Nav1.8-expressing vagal afferents. GPCRs involved in lipid sensing and inflammation (e.g. CB1R, CYSLTR2, PTGER4), and neurotransmitters signaling (CHRM4, DRD2, CRHR2) were also highly enriched in Nav1.8-expressing neurons. Finally, we identified 21 orphan GPCRs with unknown functions in vagal afferents. CONCLUSION Overall, this study provides a comprehensive description of GPCR-dependent sensing mechanisms in vagal afferents, including novel coexpression patterns, and conceivably coaction of key receptors for gut-derived molecules involved in gut-brain communication.
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Affiliation(s)
- Kristoffer L Egerod
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, and Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Nørre Allé 14, 2200, Copenhagen, Denmark.
| | - Natalia Petersen
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, and Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Nørre Allé 14, 2200, Copenhagen, Denmark
| | - Pascal N Timshel
- Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genomics, Faculty of Health and Medical Sciences, University of Copenhagen, Nørre Allé 14, 2200, Copenhagen, Denmark
| | - Jens C Rekling
- Department of Neuroscience, University of Copenhagen, Nørre Allé 14, 2200, Copenhagen, Denmark
| | - Yibing Wang
- Department of Biochemistry, UT Southwestern Medical Center at Dallas, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA
| | - Qinghua Liu
- Department of Biochemistry, UT Southwestern Medical Center at Dallas, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA
| | - Thue W Schwartz
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, and Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Nørre Allé 14, 2200, Copenhagen, Denmark
| | - Laurent Gautron
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA.
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20
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Witvliet MJ, Petersen N, Ekkerman E, Sleeboom C, van Heurn E, van der Steeg AFW. Transitional health care for patients with Hirschsprung disease and anorectal malformations. Tech Coloproctol 2017; 21:547-554. [PMID: 28674948 PMCID: PMC5550547 DOI: 10.1007/s10151-017-1656-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 03/21/2017] [Indexed: 12/27/2022]
Abstract
Background
Hirschsprung disease (HD) and anorectal malformations (ARM) are congenital disorders with potentially lifelong consequences. Although follow-up is performed in most pediatric patients, transfer to adult health care is often problematic. This study assesses transitional care with the help of questionnaires in consultation with adult patients. Methods This study was conducted in an outpatient clinic of a pediatric surgical center in the Netherlands. All patients born and treated for ARM or HD before 1992 were invited to visit our clinic. Patients completed questionnaires concerning disease-specific functioning and quality of life at an initial visit to in response to which individual treatment plans were modified. Patients were reviewed 1 year later. Results
Twenty-seven patients (17 ARM and 10 HD), mean age 27.9 years (range 17–64 years) of the 168 invited visited the transitional clinic (17%). Passive fecal incontinence was reported by 7/27, other defecatory problems, including urge incontinence and incomplete evacuation in 17/27 and anal or abdominal pain reported by 9/27. Quality of life was lower than a matched population. Only 13/27 returned for repeat assessment at 1 year; however, a further 8 reported that that their problems had resolved. In those attending follow-up, negative thoughts and feelings about their condition had decreased and one more patient was fully continent. There was no change in quality of life, bowel function or pain recorded. Twelve out of thirteen patients reported that they had found the transitional clinic satisfactory. Conclusions The transitional outpatient clinic provides care adapted to the needs and wishes of adult HD and ARM patients. It is a novel addition to quality of care of patients with complex congenital disorders.
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Affiliation(s)
- M J Witvliet
- Pediatric Surgical Center of Amsterdam, Emma Children's Hospital AMC and VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands. .,Wilhelmina Children's Hospital, Utrecht, The Netherlands.
| | - N Petersen
- Academic Medical Center, Amsterdam, The Netherlands
| | - E Ekkerman
- Pediatric Surgical Center of Amsterdam, Emma Children's Hospital AMC and VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - C Sleeboom
- Pediatric Surgical Center of Amsterdam, Emma Children's Hospital AMC and VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - E van Heurn
- Pediatric Surgical Center of Amsterdam, Emma Children's Hospital AMC and VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - A F W van der Steeg
- Pediatric Surgical Center of Amsterdam, Emma Children's Hospital AMC and VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.,Department of Medical Psychology, Center of Research on Psychology in Somatic Diseases (CoRPS), Tilburg University, Tilburg, The Netherlands
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21
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Egerod KL, Engelstoft MS, Lund ML, Grunddal KV, Zhao M, Barir-Jensen D, Nygaard EB, Petersen N, Holst JJ, Schwartz TW. Transcriptional and Functional Characterization of the G Protein-Coupled Receptor Repertoire of Gastric Somatostatin Cells. Endocrinology 2015; 156:3909-23. [PMID: 26181106 DOI: 10.1210/en.2015-1388] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In the stomach, somatostatin (SST) acts as a general paracrine negative regulator of exocrine secretion of gastric acid and pepsinogen and endocrine secretion of gastrin, ghrelin, and histamine. Using reporter mice expressing red fluorescent protein (RFP) under control of the SST promotor, we have characterized the G protein-coupled receptors expressed in gastric Sst-RFP-positive cells and probed their effects on SST secretion in primary cell cultures. Surprisingly, besides SST, amylin and PYY were also highly enriched in the SST cells. Several receptors found to regulate SST secretion were highly expressed and/or enriched. 1) The metabolite receptors calcium-sensing receptor and free fatty acid receptor 4 (GPR120) functioned as positive and negative regulators, respectively. 2) Among the neurotransmitter receptors, adrenergic receptors α1a, α2a, α2b, and β1 were all highly expressed, with norepinephrine and isoproterenol acting as positive regulators. The muscarinic receptor M3 acted as a positive regulator, whereas M4 was conceivably a negative regulator. 3) Of the hormone receptors, the GLP-1 and GIP receptors, CCKb (stimulated by both CCK and gastrin) and surprisingly the melanocortin MC1 receptor were all positive regulators. 4) The neuropeptide receptors for calcitonin gene-related peptide, adrenomedullin, and vasoactive intestinal peptide acted as positive regulators, no effect was observed using galanin and nociceptin although transcripts for the corresponding receptors appeared highly expressed. 5) The SST receptors 1 and 2 functioned in an autocrine negative feedback loop. Thus, the article provides a comprehensive map of receptors through which SST secretion is regulated by hormones, neurotransmitters, neuropeptides and metabolites that act directly on the SST cells in the gastric mucosa.
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MESH Headings
- Animals
- Cells, Cultured
- Gastric Mucosa/cytology
- Gastric Mucosa/metabolism
- Glucagon-Like Peptide-1 Receptor/genetics
- Glucagon-Like Peptide-1 Receptor/metabolism
- Humans
- In Situ Hybridization
- Islet Amyloid Polypeptide/genetics
- Islet Amyloid Polypeptide/metabolism
- Luminescent Proteins/genetics
- Luminescent Proteins/metabolism
- Male
- Mice, Knockout
- Mice, Transgenic
- Microscopy, Confocal
- Peptide YY/genetics
- Peptide YY/metabolism
- Receptors, Adrenergic/genetics
- Receptors, Adrenergic/metabolism
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Muscarinic/genetics
- Receptors, Muscarinic/metabolism
- Receptors, Neuropeptide/genetics
- Receptors, Neuropeptide/metabolism
- Receptors, Somatostatin/genetics
- Receptors, Somatostatin/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Somatostatin/genetics
- Somatostatin/metabolism
- Somatostatin-Secreting Cells/metabolism
- Stomach/cytology
- Transcriptome
- Red Fluorescent Protein
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Affiliation(s)
- Kristoffer L Egerod
- Novo Nordisk Foundation Center for Basic Metabolic Research (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., J.J.H., T.W.S.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., T.W.S.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Danish Diabetes Academy (M.S.E.), 5000 Odense, Denmark; and Department of Biomedical Sciences (J.J.H.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Maja S Engelstoft
- Novo Nordisk Foundation Center for Basic Metabolic Research (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., J.J.H., T.W.S.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., T.W.S.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Danish Diabetes Academy (M.S.E.), 5000 Odense, Denmark; and Department of Biomedical Sciences (J.J.H.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Mari L Lund
- Novo Nordisk Foundation Center for Basic Metabolic Research (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., J.J.H., T.W.S.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., T.W.S.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Danish Diabetes Academy (M.S.E.), 5000 Odense, Denmark; and Department of Biomedical Sciences (J.J.H.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Kaare V Grunddal
- Novo Nordisk Foundation Center for Basic Metabolic Research (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., J.J.H., T.W.S.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., T.W.S.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Danish Diabetes Academy (M.S.E.), 5000 Odense, Denmark; and Department of Biomedical Sciences (J.J.H.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Mirabella Zhao
- Novo Nordisk Foundation Center for Basic Metabolic Research (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., J.J.H., T.W.S.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., T.W.S.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Danish Diabetes Academy (M.S.E.), 5000 Odense, Denmark; and Department of Biomedical Sciences (J.J.H.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Dominique Barir-Jensen
- Novo Nordisk Foundation Center for Basic Metabolic Research (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., J.J.H., T.W.S.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., T.W.S.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Danish Diabetes Academy (M.S.E.), 5000 Odense, Denmark; and Department of Biomedical Sciences (J.J.H.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Eva B Nygaard
- Novo Nordisk Foundation Center for Basic Metabolic Research (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., J.J.H., T.W.S.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., T.W.S.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Danish Diabetes Academy (M.S.E.), 5000 Odense, Denmark; and Department of Biomedical Sciences (J.J.H.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Natalia Petersen
- Novo Nordisk Foundation Center for Basic Metabolic Research (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., J.J.H., T.W.S.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., T.W.S.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Danish Diabetes Academy (M.S.E.), 5000 Odense, Denmark; and Department of Biomedical Sciences (J.J.H.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Jens J Holst
- Novo Nordisk Foundation Center for Basic Metabolic Research (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., J.J.H., T.W.S.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., T.W.S.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Danish Diabetes Academy (M.S.E.), 5000 Odense, Denmark; and Department of Biomedical Sciences (J.J.H.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Thue W Schwartz
- Novo Nordisk Foundation Center for Basic Metabolic Research (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., J.J.H., T.W.S.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Laboratory for Molecular Pharmacology (K.L.E., M.S.E., M.L.L., K.V.G., M.Z., D.B.-J., E.B.N., N.P., T.W.S.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; Danish Diabetes Academy (M.S.E.), 5000 Odense, Denmark; and Department of Biomedical Sciences (J.J.H.), Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
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22
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Knudsen LA, Petersen N, Schwartz TW, Egerod KL. The MicroRNA Repertoire in Enteroendocrine Cells: Identification of miR-375 as a Potential Regulator of the Enteroendocrine Lineage. Endocrinology 2015; 156:3971-83. [PMID: 26322371 DOI: 10.1210/en.2015-1088] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Micro-RNAs (miRNAs) are crucial for many biological processes, but their role in the enteroendocrine development and differentiation has been neglected due to the elusive nature of the enteroendocrine cells. However, transgenic mice expressing fluorescent reporter proteins under the control of promoters for Cck, Gpr41, and Lgr5, ie, two different enteroendocrine markers and a marker for the stem cells, now enables identification and FACS purification of enteroendocrine cells at different stages of their differentiation along the crypt-villus axis. Surprisingly few of the 746 analyzed miRNAs differed in their expression pattern between enteroendocrine and nonenteroendocrine cells of the gut mucosa and between enteroendocrine cells of the crypt versus the villus. Thus, only let-7g-3p, miR-7b-5p (miR-7b), and miR-375-3p (miR-375) were up-regulated in the enteroendocrine cells of both the crypt and villus compared with nonenteroendocrine cells, and in situ hybridization confirmed colocalization of miR-375 with the enteroendocrine cells. Finally, functional assays using miR-375 inhibitor and mimetic in organoid cultures revealed miR-375 as a potential regulator of the enteroendocrine lineage. Overexpression of miR-375 inhibited enteroendocrine lineage development, whereas inhibition of miR-375 stimulated the development of enteroendocrine cells in vitro. Thus, through an unbiased expression screening of all miRNA, we find very few miRNAs that are differentially expressed in the gastrointestinal mucosa. Of these, miR-375 is found to be both highly expressed and enriched in the enteroendocrine cells. Additionally, miR-375 appears to negatively regulate the development of enteroendocrine cells. Consequently, miR-375 emerges as a potential target to modulate the function of the enteroendocrine system.
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Affiliation(s)
- Lina A Knudsen
- Novo Nordisk Foundation Center for Basic Metabolic Research (L.A.K., N.P., T.W.S., K.L.E.) and Laboratory for Molecular Pharmacology (L.A.K., N.P., T.W.S., K.L.E.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Natalia Petersen
- Novo Nordisk Foundation Center for Basic Metabolic Research (L.A.K., N.P., T.W.S., K.L.E.) and Laboratory for Molecular Pharmacology (L.A.K., N.P., T.W.S., K.L.E.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Thue W Schwartz
- Novo Nordisk Foundation Center for Basic Metabolic Research (L.A.K., N.P., T.W.S., K.L.E.) and Laboratory for Molecular Pharmacology (L.A.K., N.P., T.W.S., K.L.E.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Kristoffer L Egerod
- Novo Nordisk Foundation Center for Basic Metabolic Research (L.A.K., N.P., T.W.S., K.L.E.) and Laboratory for Molecular Pharmacology (L.A.K., N.P., T.W.S., K.L.E.), Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen DK-2200, Denmark
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23
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Petersen N, Reimann F, van Es JH, van den Berg BM, Kroone C, Pais R, Jansen E, Clevers H, Gribble FM, de Koning EJP. Targeting development of incretin-producing cells increases insulin secretion. J Clin Invest 2014; 125:379-85. [PMID: 25500886 DOI: 10.1172/jci75838] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 11/06/2014] [Indexed: 12/27/2022] Open
Abstract
Glucagon-like peptide-1-based (GLP-1-based) therapies improve glycemic control in patients with type 2 diabetes. While these agents augment insulin secretion, they do not mimic the physiological meal-related rise and fall of GLP-1 concentrations. Here, we tested the hypothesis that increasing the number of intestinal L cells, which produce GLP-1, is an alternative strategy to augment insulin responses and improve glucose tolerance. Blocking the NOTCH signaling pathway with the γ-secretase inhibitor dibenzazepine increased the number of L cells in intestinal organoid-based mouse and human culture systems and augmented glucose-stimulated GLP-1 secretion. In a high-fat diet-fed mouse model of impaired glucose tolerance and type 2 diabetes, dibenzazepine administration increased L cell numbers in the intestine, improved the early insulin response to glucose, and restored glucose tolerance. Dibenzazepine also increased K cell numbers, resulting in increased gastric inhibitory polypeptide (GIP) secretion. Using a GLP-1 receptor antagonist, we determined that the insulinotropic effect of dibenzazepine was mediated through an increase in GLP-1 signaling. Together, our data indicate that modulation of the development of incretin-producing cells in the intestine has potential as a therapeutic strategy to improve glycemic control.
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24
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Smith GC, Zhang ZY, Mulvey T, Petersen N, Lach S, Xiu P, Phillips A, Han W, Wang MW, Shepherd PR. Clozapine directly increases insulin and glucagon secretion from islets: implications for impairment of glucose tolerance. Schizophr Res 2014; 157:128-33. [PMID: 24906220 DOI: 10.1016/j.schres.2014.05.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 04/04/2014] [Accepted: 05/03/2014] [Indexed: 01/31/2023]
Abstract
Second generation antipsychotics cause derangements in glucose metabolism that are often interpreted as insulin resistance. In previous studies we have shown that this is not classical insulin resistance but the drugs were actually inducing a hyperglycaemic state associated with elevated hepatic glucose output (HGO) and increased levels of glucagon and insulin. However, it remains unclear whether these effects are directly elicited by drug actions in the liver and pancreas, or whether they are indirectly mediated. Here we investigated if clozapine is capable of inducing insulin resistance in the liver or enhancing insulin and glucagon secretion from the pancreas. It was observed that insulin signalling was elevated in livers from animals treated with clozapine indicating there was no insulin resistance in the early steps of insulin signalling. To explore whether the defects arise at later stages of insulin action we used an isolated perfused liver system. In this model, clozapine had no direct effect on insulin's counter regulatory effect on epinephrine-induced HGO. In isolated mouse islets clozapine significantly increased glucose-stimulated insulin secretion while simultaneously blocking glucose-induced reductions in glucagon secretion. We also show that the non-peptidic glucagon receptor like peptide-1 (GLP-1) receptor agonist Boc5 was able to overcome the inhibitory effects of clozapine on glucose metabolism. Taken together these results suggest that clozapine does not have any direct effect on glucose metabolism in the liver but it simultaneously stimulates insulin and glucagon secretion, a situation that would allow for the concurrent presence of high glucose and high insulin levels in treated animals.
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Affiliation(s)
- G C Smith
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand; Department of Pharmacology, University of New South Wales, NSW, Australia
| | - Z Y Zhang
- The National Centre for Drug Screening and the CAS Key Laboratory of Receptor Research, Shanghai, Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - T Mulvey
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - N Petersen
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), Singapore; Hubrecht Institute for Development Biology and Stem Cell Research, Utrecht, The Netherlands
| | - S Lach
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - P Xiu
- Department of General Surgery, Qianfoshan Hospital, Shandong University, Jinan 250014, China
| | - A Phillips
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - W Han
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), Singapore
| | - M-W Wang
- The National Centre for Drug Screening and the CAS Key Laboratory of Receptor Research, Shanghai, Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
| | - P R Shepherd
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand; The Maurice Wilkins Centre, Auckland, New Zealand.
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25
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Petersen N, Reimann F, Bartfeld S, Farin HF, Ringnalda FC, Vries RGJ, van den Brink S, Clevers H, Gribble FM, de Koning EJP. Generation of L cells in mouse and human small intestine organoids. Diabetes 2014; 63:410-20. [PMID: 24130334 PMCID: PMC4306716 DOI: 10.2337/db13-0991] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Upon a nutrient challenge, L cells produce glucagon-like peptide 1 (GLP-1), a powerful stimulant of insulin release. Strategies to augment endogenous GLP-1 production include promoting L-cell differentiation and increasing L-cell number. Here we present a novel in vitro platform to generate functional L cells from three-dimensional cultures of mouse and human intestinal crypts. We show that short-chain fatty acids selectively increase the number of L cells, resulting in an elevation of GLP-1 release. This is accompanied by the upregulation of transcription factors associated with the endocrine lineage of intestinal stem cell development. Thus, our platform allows us to study and modulate the development of L cells in mouse and human crypts as a potential basis for novel therapeutic strategies in patients with type 2 diabetes.
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Affiliation(s)
- Natalia Petersen
- Hubrecht Institute for Development Biology and Stem Cell Research, Utrecht, Netherlands
| | - Frank Reimann
- Cambridge Institute for Medical Research, Department of Clinical Biochemistry, Addenbrooke’s Hospital, Cambridge, UK
| | - Sina Bartfeld
- Hubrecht Institute for Development Biology and Stem Cell Research, Utrecht, Netherlands
| | - Henner F. Farin
- Hubrecht Institute for Development Biology and Stem Cell Research, Utrecht, Netherlands
| | - Femke C. Ringnalda
- Hubrecht Institute for Development Biology and Stem Cell Research, Utrecht, Netherlands
| | - Robert G. J. Vries
- Hubrecht Institute for Development Biology and Stem Cell Research, Utrecht, Netherlands
| | | | - Hans Clevers
- Hubrecht Institute for Development Biology and Stem Cell Research, Utrecht, Netherlands
- Utrecht University Medical Center, Utrecht, Netherlands
| | - Fiona M. Gribble
- Cambridge Institute for Medical Research, Department of Clinical Biochemistry, Addenbrooke’s Hospital, Cambridge, UK
| | - Eelco J. P. de Koning
- Hubrecht Institute for Development Biology and Stem Cell Research, Utrecht, Netherlands
- Department of Nephrology, Leiden University Medical Center, Leiden, Netherlands
- Department of Endocrinology, Leiden University Medical Center, Leiden, Netherlands
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26
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Böhlke JK, Honnorez J, Honnorez-Guerstein BM, Muehlenbachs K, Petersen N. Heterogeneous alteration of the upper oceanic crust: Correlation of rock chemistry, magnetic properties, and O isotope ratios with alteration patterns in basalts from site 396B, DSDP. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jb086ib09p07935] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Ortega-Gutierrez S, Petersen N, Reccius A, Huang A, Linares-Tapia G, Marshall R, Badjatia N. Changes on Dynamic Cerebral Autoregulation Are Associated with Delayed Cerebral Ischemia in Patients with Aneurysmal Subarachnoid Hemorrhage (P06.257). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p06.257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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28
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Petersen N, Ortega-Gutierrez S, Reccius A, Huang A, Masurkar A, Marshall R. Dynamic Cerebral Autoregulation Is Transiently Impaired after Large-Vessel Acute Ischemic Stroke (S19.002). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.s19.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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29
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Hsü KJ, He Q, McKenzie JA, Weissert H, Perch-Nielsen K, Oberhänsli H, Kelts K, Labrecque J, Tauxe L, Krähenbühl U, Percival SF, Wright R, Karpoff AM, Petersen N, Tucker P, Poore RZ, Gombos AM, Pisciotto K, Carman MF, Schreiber E. Mass mortality and its environmental and evolutionary consequences. Science 2010; 216:249-56. [PMID: 17832725 DOI: 10.1126/science.216.4543.249] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The latest Mesozoic and earliest Tertiary sediments at Deep Sea Drilling Project site 524 provide an amplified record of environmental and biostratographic changes at the end of Cretaceous. Closely spaced samples, representing time intervals as short as 10(2) or 10(3) years, were analyzed for their bulk carbonate and trace-metal compositions, and for oxygen and carbon isotopic compositions. The data indicate that at the end of Cretaceous, when a high proportion of the ocean's planktic organisms were eliminated, an associated reduction in productivity led to a partial transfer of dissolved carbon dioxide from the oceans to the atmosphere. This resulted in a large increase of the atmospheric carbon dioxide during the next 50,000 years, which is believed to have caused a temperature rise revealed by the oxygen-isotope data. The lowermost Tertiary sediments at site 524 include fossils with Cretaceous affinities, which may include both reworked individuals and some forms that survived for a while after the catastrophe. Our data indicate that many of the Cretaceous pelagic organisms became extinct over a period of a few tens of thousands of years, and do not contradict the scenario of cometary impact as a cause of mass mortality in the oceans, as suggested by an iridium anomaly at the Cretaceous-Tertiary boundary.
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30
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Giannone L, Cerna M, Cole R, Fitzek M, Kallenbach A, Lüddecke K, McCarthy P, Scarabosio A, Schneider W, Sips A, Treutterer W, Vrancic A, Wenzel L, Yi H, Behler K, Eich T, Eixenberger H, Fuchs J, Haas G, Lexa G, Marquardt M, Mlynek A, Neu G, Raupp G, Reich M, Sachtleben J, Schuhbeck K, Zehetbauer T, Concezzi S, Debelle T, Marker B, Munroe M, Petersen N, Schmidt D. Data acquisition and real-time signal processing of plasma diagnostics on ASDEX Upgrade using LabVIEW RT. Fusion Engineering and Design 2010. [DOI: 10.1016/j.fusengdes.2010.03.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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31
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Spring S, Amann R, Ludwig W, Schleifer KH, van Gemerden H, Petersen N. Dominating role of an unusual magnetotactic bacterium in the microaerobic zone of a freshwater sediment. Appl Environ Microbiol 2010; 59:2397-403. [PMID: 16349008 PMCID: PMC182297 DOI: 10.1128/aem.59.8.2397-2403.1993] [Citation(s) in RCA: 211] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A combination of polymerase chain reaction-assisted rRNA sequence retrieval and fluorescent oligonucleotide probing was used to identify in situ a hitherto unculturable, big, magnetotactic, rod-shaped organism in freshwater sediment samples collected from Lake Chiemsee. Tentatively named "Magnetobacterium bavaricum," this bacterium is evolutionarily distant from all other phylogenetically characterized magnetotactic bacteria and contains unusually high numbers of magnetosomes (up to 1,000 magnetosomes per cell). The spatial distribution in the sediment was studied, and up to 7 x 10 active cells per cm were found in the microaerobic zone. Considering its average volume (25.8 +/- 4.1 mum) and relative abundance (0.64 +/- 0.17%), "M. bavaricum" may account for approximately 30% of the microbial biovolume and may therefore be a dominant fraction of the microbial community in this layer. Its microhabitat and its high content of sulfur globules and magnetosomes suggest that this organism has an iron-dependent way of energy conservation which depends on balanced gradients of oxygen and sulfide.
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Affiliation(s)
- S Spring
- Lehrstuhl für Mikrobiologie, Technische Universität München, Arcisstrasse 21, and Institut für Geophysik, Ludwig-Maximilians-Universität München, 8000 Munich 2, Germany, and Department of Microbiology, University of Groningen, 9751 NN Haren, The Netherlands
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32
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Kang J, Kang N, Yu Y, Zhang J, Petersen N, Tian GF, Nedergaard M. Sulforhodamine 101 induces long-term potentiation of intrinsic excitability and synaptic efficacy in hippocampal CA1 pyramidal neurons. Neuroscience 2010; 169:1601-9. [PMID: 20600669 DOI: 10.1016/j.neuroscience.2010.06.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 05/21/2010] [Accepted: 06/10/2010] [Indexed: 10/19/2022]
Abstract
Sulforhodamine 101 (SR101) has been extensively used for investigation as a specific marker for astroglia in vivo and activity-dependent dye for monitoring regulated exocytosis. Here, we report that SR101 has bioactive effects on neuronal activity. Perfusion of slices with SR101 (1 microM) for 10 min induced long-term potentiation of intrinsic neuronal excitability (LTP-IE) and a long-lasting increase in evoked EPSCs (eEPSCs) in CA1 pyramidal neurons in hippocampal slices. The increase in intrinsic neuronal excitability was a result of negative shifts in the action potential (AP) threshold. The N-methyl D-aspartate receptor (NMDAR) antagonist, AP-5 (50 microM), blocked SR101-induced LTP-IE, but glutamate receptor blockers, AP-5 (50 microM), MCPG (200 microM), and MSOP (100 microM), only partially blocked SR101-induced potentiation of eEPSCs. SR101 induced an enhancement of evoked synaptic NMDAR currents, suggesting that SR101 enhances activation of synaptic NMDARs. SR101-induced LTP-IE and potentiation of synaptic transmission triggered spontaneous neuronal firing in slices and in vivo epileptic seizures. Our results suggest that SR101 is an epileptogenic agent that long-lastingly lowers the AP threshold to increase intrinsic neuronal excitability and enhances the synaptic efficacy to increase synaptic inputs. As such, SR101 can be used as an experimental tool to induce epileptic seizures.
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Affiliation(s)
- J Kang
- Department of Cell Biology and Anatomy, New York Medical College, Basic Science Building, Valhalla, NY 10595, USA.
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33
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Jogler C, Niebler M, Lin W, Kube M, Wanner G, Kolinko S, Stief P, Beck AJ, de Beer D, Petersen N, Pan Y, Amann R, Reinhardt R, Schüler D. Cultivation-independent characterization of ‘Candidatus Magnetobacterium bavaricum’ via ultrastructural, geochemical, ecological and metagenomic methods. Environ Microbiol 2010; 12:2466-78. [DOI: 10.1111/j.1462-2920.2010.02220.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Shah A, Petersen N, Soto-Wright V. Prospective Analysis of 125 Consecutive Cases Comparing the Implementation of Total Laparoscopic Hysterectomy and Robotic Hysterectomy for Benign Disease. J Minim Invasive Gynecol 2009. [DOI: 10.1016/j.jmig.2009.08.357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Petersen N, Ödman P, Cervera A, Stocks S, Lantz AE, Gernaey K. Monitoring of glucose and ammonium concentration in Streptomyces coelicolor fermentations using in situ Nir. N Biotechnol 2009. [DOI: 10.1016/j.nbt.2009.06.152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Crone C, Petersen N, Nielsen J, Gimenez-Roldan S. FC15.3 Impaired corticospinal transmission and reciprocal inhibition in the leg but not the arm in patients with neurolathyrism. Clin Neurophysiol 2006. [DOI: 10.1016/j.clinph.2006.06.052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Hansen NL, Hansen S, Crone C, Christensen LO, Petersen N, Nielsen JE, Biering-Sørensen F, Nielsen JB. Synchronization of lower limb motor units in spastic patients. Suppl Clin Neurophysiol 2003; 53:178-86. [PMID: 12740993 DOI: 10.1016/s1567-424x(09)70154-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Affiliation(s)
- N L Hansen
- Department of Medical Physiology, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
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Davila JA, Petersen N, El-Serag HB. #5 Birth cohort effect and the incidence of hepatocellular carcinoma. Ann Epidemiol 2002. [DOI: 10.1016/s1047-2797(02)00293-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Enríquez-Denton M, Morita H, Christensen LOD, Petersen N, Sinkjaer T, Nielsen JB. Interaction between peripheral afferent activity and presynaptic inhibition of ia afferents in the cat. J Neurophysiol 2002; 88:1664-74. [PMID: 12364496 DOI: 10.1152/jn.2002.88.4.1664] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It has been demonstrated in man that the H-reflex is more depressed by presynaptic inhibition than the stretch reflex. Here we investigated this finding further in the alpha-chloralose-anesthetized cat. Soleus monosynaptic reflexes were evoked by electrical stimulation of the tibial nerve or by stretch of the triceps surae muscle. Conditioning stimulation of the posterior biceps and semitendinosus nerve (PBSt) produced a significantly stronger depression of the electrically than the mechanically evoked reflexes. The depression of the reflexes has been shown to be caused by presynaptic inhibition of triceps surae Ia afferents. We investigated the hypothesis that repetitive activation of peripheral afferents may reduce their sensitivity to presynaptic inhibition. In triceps surae motoneurones, we measured the effect of presynaptic inhibition on excitatory postsynaptic potentials (EPSPs) produced by repetitive activation of the peripheral afferents or by fast and slow muscle stretch. EPSPs evoked by single electrical stimulation of the tibial nerve or by fast muscle stretch were significantly depressed by PBSt stimulation. However, the last EPSP in a series of EPSPs evoked by a train of electrical stimuli (5-6 shocks, 150-200 Hz) was significantly less depressed by the conditioning stimulation than the first EPSP. In addition, the last part of the long-lasting EPSPs evoked by a slow muscle stretch was also less depressed than the first part. A single EPSP evoked by stimulation of the medial gastrocnemius nerve was less depressed when preceded by a train of stimuli applied to the same nerve than when the same train of stimuli was applied to a synergistic nerve. The decreased sensitivity of the test EPSP to presynaptic inhibition was maximal when it was evoked within 20 ms after the train of EPSPs. It was not observed at intervals longer than 30 ms. These findings suggest that afferent activity may decrease the efficiency of presynaptic inhibition. We propose that the described interaction between afferent nerve activity and presynaptic inhibition may partly explain why electrically and mechanically evoked reflexes are differently sensitive to presynaptic inhibition.
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Affiliation(s)
- M Enríquez-Denton
- Division of Neurophysiology, Department of Medical Physiology, The Panum Institute. University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark.
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Abstract
BACKGROUND AND AIMS It has been suggested that gastric cardia adenocarcinoma (GCA) is a distinct entity from oesophageal adenocarcinoma (OA). We examined several epidemiological features of GCA and OA in the USA to elucidate differences/similarities between these malignancies. METHODS Using the database of Surveillance, Epidemiology, and End Results (SEER) program, we examined incidence rates for temporal changes, and ethnic and age distributions, and performed birth cohort analyses for cases with morphologically and histologically confirmed OA or GCA. RESULTS The age adjusted incidence rates of OA rose progressively, reaching 1.8 per 100 000 (95% confidence interval 1.7-1.9) during 1987-1991 and 2.5 per 100 000 (2.3-2.6) during 1992-1996. In 1992-1996, Whites were affected five times more than Blacks, and men eight times more than women. A significant increase in incidence occurred among younger persons aged 45-65 years. Irrespective of age, OA was characterised by higher incidence rates among more recent birth cohorts: a 40% increase in incidence for each five year increase in the date of birth--a "birth cohort effect". On the other hand, the incidence rates of GCA reached their highest level of 3.3 per 100 000 (3.2-3.4) in 1987-1991 and subsequently declined during 1992-1996 to 3.1 per 100 000 (3.0-3.3). Whites were affected twice more than blacks and men five times more than women. Most patients with GCA were older than 60 years with no increase among younger persons and no birth cohort effect (p=0.99). CONCLUSION Several significant epidemiological differences exist between OA and GCA. These differences suggest that these two malignancies are separate entities with different risk factors.
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Affiliation(s)
- H B El-Serag
- Section of Gastroenterology, Houston Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas77030, USA.
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Dreier J, Götting C, Wolff C, Petersen N, Kleesiek K. Recent experience with human immunodeficiency virus transmission by cellular blood products in Germany: antibody screening is not sufficient to prevent transmission. Vox Sang 2002; 82:80-3. [PMID: 11906672 DOI: 10.1046/j.0042-9007.2001.00144.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVES A case of transfusion-related human immunodeficiency virus-1 (HIV-1) transmission was not detected by standard HIV antibody screening. MATERIALS AND METHODS In a look-back procedure, the preceding donations were extensively analyzed by nucleic acid amplification technology (NAT) screening and alternative serological tests. RESULTS The chain of infection could be demonstrated by the analysis of HIV-specific amplicon sequences from the donor and the recipient. CONCLUSION This case report clearly indicates that the remaining risk of transfusion-related transmission of HIV could be severely reduced, not only by the use of NAT screening but even by HIV antigen screening or more sensitive HIV antibody assays.
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Affiliation(s)
- J Dreier
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
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Crone C, Nielsen J, Petersen N, Tijssen MA, van Dijk JG. Patients with the major and minor form of hyperekplexia differ with regards to disynaptic reciprocal inhibition between ankle flexor and extensor muscles. Exp Brain Res 2001; 140:190-7. [PMID: 11521151 DOI: 10.1007/s002210100808] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2000] [Accepted: 04/20/2001] [Indexed: 10/27/2022]
Abstract
The aim of the present study was to investigate the contribution of reciprocal inhibition to muscle tone by examining the transmission in the reciprocal inhibitory pathway in patients with a known defect in the glycine receptor. The study was performed in eight patients with hereditary hyperekplexia, six with the major form and two with the minor form of the disease. A mutation in the alpha1-subunit of the glycine receptor had been demonstrated in the patients with the major form, whereas no mutation was seen in the patients with the minor form. Disynaptic reciprocal inhibition, which is presumed to be mediated by glycine, was not seen in the patients with the major form of the disease, while it could be evoked in the patients with the minor form of the disease. Presynaptic inhibition, which is presumed to be mediated by GABA, was seen in both types of patients. It is concluded that the major form of hereditary hyperekplexia is associated with impaired transmission in glycinergic reciprocal inhibitory pathways. The findings demonstrate the importance of reciprocal inhibition for the muscle tone in man, and it is suggested that the impaired reciprocal inhibition seen in patients with a defect in the glycine receptor may contribute to the increased muscle stiffness that is observed in these patients.
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Affiliation(s)
- C Crone
- Department of Clinical Neurophysiology, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark.
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Mogensen KB, Friis P, Hübner J, Petersen N, Jørgensen AM, Telleman P, Kutter JP. Ultraviolet transparent silicon oxynitride waveguides for biochemical microsystems. Opt Lett 2001; 26:716-718. [PMID: 18040430 DOI: 10.1364/ol.26.000716] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The UV wavelength region is of great interest in absorption spectroscopy, which is employed for chemical analysis, since many organic compounds absorb in only this region. Germanium-doped silica, which is often preferred as the waveguide core material in optical devices for telecommunication, cannot accommodate guidance below 400 nm, owing to the presence of UV-absorbing centers. We show that silicon oxynitride (SiO(x) N(y)) waveguides exhibit very good UV performance. The propagation loss for 24-microm -wide SiO(x)N (y) waveguides was found to be ~1.0dB/cm in the wavelength range 220-550 nm. The applicability of these waveguides was demonstrated in a biochemical microsystem consisting of multimode buried-channel SiO(x)N (y) waveguides that were monolithically integrated with microfluidic channels. Absorption measurements of a beta -blocking agent, propranolol, at 212-215 nm were performed. The detection limit was reached at a concentration of 13microM , with an optical path length of 500microm (signal/noise ratio, 2).
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Sallmann S, Jüttler E, Prinz S, Petersen N, Knopf U, Weiser T, Schwaninger M. Induction of interleukin-6 by depolarization of neurons. J Neurosci 2000; 20:8637-42. [PMID: 11102468 PMCID: PMC6773078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2000] [Revised: 08/31/2000] [Accepted: 09/15/2000] [Indexed: 02/18/2023] Open
Abstract
Interleukin-6 (IL-6) has neuromodulatory and neuroprotective effects in vivo. It is expressed in glial cells and neurons both under physiological conditions and in various neurological diseases. Although the expression of IL-6 in glia has been intensely investigated, little is known about the regulation of IL-6 production by neurons. Therefore, we investigated the regulation of IL-6 expression in neurons. Membrane depolarization raised IL-6 mRNA accumulation in primary cortical cells and the PC-12 cell line. In vivo, IL-6 mRNA in the brain increased significantly after epileptic seizures. To investigate IL-6 gene transcription, PC-12 cells were transfected with reporter gene constructs containing the human IL-6 promoter. Membrane depolarization raised IL-6 transcription twofold to fourfold. This increase could be blocked by lowering extracellular Ca(2+) levels or by inhibiting L-type Ca(2+) channels or Ca(2+)/calmodulin-dependent protein kinases. Internal mutations in various elements of the IL-6 promoter revealed the glucocorticoid response element (GRE) 2 to be a depolarization-responsive element. Although the GRE2 bound the glucocorticoid receptor (GR) and was stimulated by dexamethasone, the GR was not responsible for the effect of membrane depolarization because a consensus GRE did not mediate stimulation by membrane depolarization. Instead, another yet undefined factor that binds to the IL-6 GRE2 may mediate the response to membrane depolarization. These data demonstrate that the expression of IL-6 in neurons is regulated by membrane depolarization and suggest a novel Ca(2+)-responsive promoter element. Through this mechanism, IL-6 may function as a neuromodulator induced by neuronal activity.
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MESH Headings
- Animals
- Calcium/metabolism
- Calcium Channel Blockers/pharmacology
- Calcium Channels, L-Type/metabolism
- Calcium-Calmodulin-Dependent Protein Kinases/metabolism
- Cell Membrane/drug effects
- Cell Membrane/metabolism
- Cells, Cultured
- Dexamethasone/pharmacology
- Extracellular Space/metabolism
- Gene Expression Regulation/physiology
- Genes, Reporter
- Interleukin-6/genetics
- Interleukin-6/metabolism
- Male
- Mice
- Mutagenesis, Site-Directed
- Neurons/cytology
- Neurons/metabolism
- PC12 Cells
- Potassium/metabolism
- Potassium/pharmacology
- Promoter Regions, Genetic/genetics
- RNA, Messenger/metabolism
- Rats
- Receptors, Glucocorticoid/metabolism
- Regulatory Sequences, Nucleic Acid/drug effects
- Regulatory Sequences, Nucleic Acid/genetics
- Transcription, Genetic/drug effects
- Transfection
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Affiliation(s)
- S Sallmann
- Department of Neurology, University of Heidelberg, 69120 Heidelberg, Germany
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Hanzlik M, Heunemann C, Holtkamp-Rötzler E, Winklhofer M, Petersen N, Fleissner G. Superparamagnetic magnetite in the upper beak tissue of homing pigeons. Biometals 2000; 13:325-31. [PMID: 11247039 DOI: 10.1023/a:1009214526685] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Homing pigeons have been subject of various studies trying to detect magnetic material which might be involved in magnetic field perception. Here we focus on the upper-beak skin of homing pigeons, a region that has previously been shown to contain nerves sensitive to changes of the ambient magnetic field. We localized Fe3+ concentrations in the subcutis and identified the material by transmission electronmicroscopy (TEM) as aggregates of magnetite nanocrystals (with grain sizes between 1 and 5 nm). The particles form clusters of 1-3 microm diameter, which are arranged in distinct coherent elongated structures, associated with nervous tissue and located between fat cells. Complementary low-temperature magnetic measurements confirm the microscopic observations of fine-grained superparamagnetic particles in the tissue. Neither electron-microscopic nor magnetic measurements revealed any single-domain magnetite in the upper-beak skin tissue.
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Affiliation(s)
- M Hanzlik
- Institut für Allgemeine und Angewandte Geophysik, Ludwig-Maximilians-Universität, Munich, Germany
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Abstract
The cerebral activation during bicycle movements was investigated by oxygen-15-labelled H2O positron emission tomography (PET) in seven healthy human subjects. Compared to rest active bicycling significantly activated sites bilaterally in the primary sensory cortex, primary motor cortex (M1) and supplementary motor cortex (SMA) as well as the anterior part of cerebellum. Comparing passive bicycling movements with rest, an almost equal activation was observed. Subtracting passive from active bicycle movements, significant activation was only observed in the leg area of the primary motor cortex and the precuneus, but not in the primary sensory cortex (S1). The M1 activation was positively correlated (alpha=0.75-0.85, t=6.4, P<10(-5)) with the rate of the active bicycle movements. Imagination of bicycle movements compared to rest activated bilaterally sites in the SMA. It is suggested that the higher motor centres, including the primary and supplementary motor cortices as well as the cerebellum, take an active part in the generation and control of rhythmic motor tasks such as bicycling.
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Affiliation(s)
- L O Christensen
- Department of Medical Physiology, University of Copenhagen, Denmark
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Abstract
The existence of transcortical reflex pathways in the control of distal arm and hand muscles in man is now widely accepted. Much more controversy exists regarding a possible contribution of such reflexes to the control of leg muscles. It is often assumed that transcortical reflex pathways play no, or only a minor, role in the control of leg muscles. Transcortical reflex pathways according to this view are reserved for the control of the distal upper limb and are seen in close relation to the evolution of the primate hand. Here we review data, which provide evidence that transcortical reflexes do exist for lower limb muscles and may play a significant role in the control of at least some of these muscles. This evidence is based on animal research, recent experiments combining transcranial magnetic stimulation with peripheral electrical and mechanical stimulation in healthy subjects and neurological patients. We propose that afferent activity from muscle and skin may play a role in the regulation of bipedal gait through transcortical pathways.
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Affiliation(s)
- L O Christensen
- Department of Medical Physiology, University of Copenhagen, Copenhagen, Denmark
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Marchand-Pauvert V, Mazevet D, Nielsen J, Petersen N, Pierrot-Deseilligny E. Distribution of non-monosynaptic excitation to early and late recruited units in human forearm muscles. Exp Brain Res 2000; 134:274-8. [PMID: 11037296 DOI: 10.1007/s002210000498] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The distribution of monosynaptic and nonmonosynaptic excitation was investigated within flexor carpi radialis (FCR) and extensor carpi radialis (ECR) motoneurone (MN) pools. FCR H reflexes of different size were conditioned by various conditioning stimuli eliciting different effects: (1) musculocutaneous-induced non-monosynaptic excitation of FCR MNs at the onset of biceps contraction, (2) heteronymous monosynaptic Ia facilitation, (3) reciprocal Ia inhibition, and (4) presynaptic inhibition of Ia terminals. Musculocutaneous-induced non-monosynaptic excitation increased continuously with the size of the unconditioned reflex. In contrast, heteronymous monosynaptic Ia excitation first increased and then decreased, with increases in the unconditioned reflex size, reciprocal inhibition and presynaptic inhibition showing an approximately similar tendency. This suggests that the non-monosynaptic excitation is distributed more evenly to early and late recruited MNs than monosynaptic Ia excitation, reciprocal inhibition and presynaptic inhibition. A different pattern of homonymous radial-induced monosynaptic and non-monosynaptic excitation was also found for individual ECR MNs investigated with the poststimulus time histogram (PSTH) method. Whereas the monosynaptic Ia excitation tended to be most marked in lower threshold MUs, the nonmonosynaptic excitation was evenly distributed to lower and higher threshold MUs. We propose that the even distribution of the non-monosynaptic excitation in the motoneuronal pool may be of significance when it is necessary to activate a wide range of MNs more or less simultaneously.
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Affiliation(s)
- V Marchand-Pauvert
- Neurophysiologie Clinique, Rééducation, Hôpital de la Salpétrière, Paris, France
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Orsnes G, Crone C, Krarup C, Petersen N, Nielsen J. The effect of baclofen on the transmission in spinal pathways in spastic multiple sclerosis patients. Clin Neurophysiol 2000; 111:1372-9. [PMID: 10904217 DOI: 10.1016/s1388-2457(00)00352-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES To measure the effect of baclofen on the transmission in different spinal pathways to soleus motoneurones in spastic multiple sclerosis patients. METHODS Baclofen was administered orally in 14 and intrathecally in 8 patients. H(max)/M(max), presynaptic inhibition by biceps femoris tendon tap of femoral nerve stimulation, depression of the soleus H-reflex following previous activation of the Ia afferents from the soleus muscle (i.e. postactivation depression), disynaptic reciprocal Ia inhibition of the soleus H-reflex and the number of backpropagating action potentials in primary afferents, which may be a sign of presynaptic inhibition, were examined. RESULTS Baclofen depressed the soleus H(max)/M(max) ratio significantly following oral and intrathecal baclofen. None of the two tests of presynaptic inhibition, or the postactivation depression or the disynaptic reciprocal Ia inhibition of the soleus H-reflex were affected by baclofen administration. Also the action potentials of the primary afferents were unchanged during baclofen administration. CONCLUSIONS The antispastic effect of baclofen is not caused by an effect on the transmitter release from Ia afferents or on disynaptic reciprocal Ia inhibition. One possible explanation of the depression of the H-reflex by baclofen is suggested to be a direct depression of motoneuronal excitability.
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Affiliation(s)
- G Orsnes
- Department of Neurology, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen O., Denmark.
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Enríquez-Denton M, Nielsen J, Perreault MC, Morita H, Petersen N, Hultborn H. Presynaptic control of transmission along the pathway mediating disynaptic reciprocal inhibition in the cat. J Physiol 2000; 526 Pt 3:623-37. [PMID: 10922013 PMCID: PMC2270037 DOI: 10.1111/j.1469-7793.2000.t01-1-00623.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
In cat lumbar motoneurones, disynaptic inhibitory postsynaptic potentials (IPSPs) evoked by stimulation of antagonist motor nerves were depressed for at least 150 ms following conditioning stimulation of flexor (1.7-2 times threshold (T)) and ankle extensor (5T) nerves. The aim of the present study was to investigate the possibility that this depression is caused by presynaptic inhibitory mechanisms acting at the terminals of group I afferent fibres projecting to the Ia inhibitory interneurones and/or the terminals of these interneurones to the target motoneurones. Conditioning stimulation of flexor, but not ankle extensor, nerves evoked a depression of the monosynaptic Ia excitatory postsynaptic potentials (EPSPs) recorded intracellularly in Ia inhibitory interneurones. This depression lasted between 200 and 700 ms and was not accompanied by a depression of the monosynaptic EPSPs evoked by stimulation of descending pathways. These results suggest that flexor, but not ankle extensor, group I afferent fibres can modulate sensory transmission at the synapse between Ia afferent fibres and Ia inhibitory interneurones. Conditioning stimulation of flexor muscle nerves, extensor muscle nerves and cutaneous nerves produced a long-lasting increase in excitability of the terminals of the Ia inhibitory interneurones. The increase in the excitability of the terminals was not secondary to an electrotonic spread of synaptic excitation at the soma. Indeed, concomitant with the excitability increase of the terminals there were signs of synaptic inhibition in the soma. The unitary IPSPs induced in target motoneurones following the spike activity of single Ia inhibitory interneurones were depressed by conditioning stimulation of muscle and cutaneous nerves. Since the conditioning stimulation also evoked compound IPSPs in those motoneurones, a firm conclusion as to whether unitary IPSP depression involved presynaptic inhibitory mechanism of the terminals of the interneurones could not be reached. The possibility that the changes in excitability of the Ia interneuronal terminals reflect the presence of a presynaptic inhibitory mechanism similar to that operating at the terminals of the afferent fibres (presynaptic inhibition) is discussed.1. In cat lumbar motoneurones, disynaptic inhibitory postsynaptic potentials (IPSPs) evoked by stimulation of antagonist motor nerves were depressed for at least 150 ms following conditioning stimulation of flexor (1.7-2 times threshold (T)) and ankle extensor (5T) nerves. The aim of the present study was to investigate the possibility that this depression is caused by presynaptic inhibitory mechanisms acting at the terminals of group I afferent fibres projecting to the Ia inhibitory interneurones and/or the terminals of these interneurones to the target motoneurones. Conditioning stimulation of flexor, but not ankle extensor, nerves evoked a depression of the monosynaptic Ia excitatory postsynaptic potentials (EPSPs) recorded intracellularly in Ia inhibitory interneurones. This depression lasted between 200 and 700 ms and was not accompanied by a depression of the monosynaptic EPSPs evoked by stimulation of descending pathways. These results suggest that flexor, but not ankle extensor, group I afferent fibres can modulate sensory transmission at the synapse between Ia afferent fibres and Ia inhibitory interneurones. Conditioning stimulation of flexor muscle nerves, extensor muscle nerves and cutaneous nerves produced a long-lasting increase in excitability of the terminals of the Ia inhibitory interneurones. The increase in the excitability of the terminals was not secondary to an electrotonic spread of synaptic excitation at the soma. Indeed, concomitant with the excitability increase of the terminals there were signs of synaptic inhibition in the soma. The unitary IPSPs induced in target motoneurones following the spike activity of single Ia inhibitory interneurones were depressed by conditioning stimulation
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Affiliation(s)
- M Enríquez-Denton
- Department of Medical Physiology, The Panum Institute, Blegdamsvej 3, 2200 Copenhagen N, Denmark
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