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Khajavi N, Riçku K, Schreier PCF, Gentz T, Beyerle P, Cruz E, Breit A, Reinach PS, Gudermann T. Chronic Mg 2+ Deficiency Does Not Impair Insulin Secretion in Mice. Cells 2023; 12:1790. [PMID: 37443824 PMCID: PMC10340716 DOI: 10.3390/cells12131790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/28/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023] Open
Abstract
Magnesium is an essential mediator of a vast number of critical enzymatic cellular reactions in the human body. Some clinical epidemiological studies suggest that hypomagnesemia accounts for declines in insulin secretion in patients with type 2 diabetes (T2D); however, the results of various experimental studies do not support this notion. To address this discrepancy, we assessed the short- and long-term effects of hypomagnesemia on β-cell function and insulin secretion in primary mouse islets of Langerhans and in a mouse model of hypomagnesemia known as Trpm6Δ17 /fl;Villin1-Cre mice. We found that lowering the extracellular Mg2+ concentration from 1.2 mM to either 0.6 or 0.1 mM remarkably increased glucose-induced insulin secretion (GIIS) in primary islets isolated from C57BL/6 mice. Similarly, both the plasma insulin levels and GIIS rose in isolated islets of Trpm6Δ17 /fl;Villin1-Cre mice. We attribute these rises to augmented increases in intracellular Ca2+ oscillations in pancreatic β-cells. However, the glycemic metabolic profile was not impaired in Trpm6Δ17 /fl;Villin1-Cre mice, suggesting that chronic hypomagnesemia does not lead to insulin resistance. Collectively, the results of this study suggest that neither acute nor chronic Mg2+ deficiency suppresses glucose-induced rises in insulin secretion. Even though hypomagnesemia can be symptomatic of T2D, such deficiency may not account for declines in insulin release in this disease.
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Affiliation(s)
- Noushafarin Khajavi
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Klea Riçku
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Pascale C. F. Schreier
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Tanja Gentz
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Philipp Beyerle
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Emmanuel Cruz
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Peter S. Reinach
- Ophthalmology Department, Wenzhou Medical University, Wenzhou 325015, China;
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
- German Center for Lung Research, 81377 Munich, Germany
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Liskiewicz D, Zhang Q, Barthem C, Jastroch M, Liskiewicz A, Khajavi N, Grandl G, Coupland C, Kleinert M, Garcia-Caceres C, Novikoff A, Maity G, Boehm U, Tschöp M, Müller T. Neuronal loss of TRPM8 leads to obesity and glucose intolerance in male mice. Mol Metab 2023; 72:101714. [PMID: 36966947 PMCID: PMC10106965 DOI: 10.1016/j.molmet.2023.101714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/13/2023] [Accepted: 03/20/2023] [Indexed: 03/31/2023] Open
Abstract
OBJECTIVE Mice with global deletion of the transient receptor potential channel melastatin family member 8 (TRPM8) are obese, and treatment of diet-induced obese (DIO) mice with TRPM8 agonists decrease body weight. Whether TRPM8 signaling regulates energy metabolism via central or peripheral effects is unknow. Here we assessed the metabolic phenotype of mice with either Nestin Cre-mediated neuronal loss of TRPM8, or with deletion of TRPM8 in Advillin Cre positive sensory neurons of the peripheral nervous system (PNS). METHODS Nestin Cre- and Advillin Cre-Trpm8 knock-out (KO) mice were metabolically phenotyped under chronic exposure to either chow or high-fat diet (HFD), followed by assessment of energy and glucose metabolism. RESULTS At room temperature, chow-fed neuronal Trpm8 KO are obese and show decreased energy expenditure when acutely treated with the TRPM8 selective agonist icilin. But body weight of neuronal Trpm8 KO mice is indistinguishable from wildtype controls at thermoneutrality, or when mice are chronically exposed to HFD-feeding. In contrast to previous studies, we show that the TRPM8 agonist icilin has no direct effect on brown adipocytes, but that icilin stimulates energy expenditure, at least in part, via neuronal TRPM8 signaling. We further show that lack of TRPM8 in sensory neurons of the PNS does not lead to a metabolically relevant phenotype. CONCLUSIONS Our data indicate that obesity in TRPM8-deficient mice is centrally mediated and likely originates from alterations in energy expenditure and/or thermal conductance, but does not depend on TRPM8 signaling in brown adipocytes or sensory neurons of the PVN.
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Khajavi N, Beck A, Riçku K, Beyerle P, Jacob K, Syamsul SF, Belkacemi A, Reinach PS, Schreier PC, Salah H, Popp T, Novikoff A, Breit A, Chubanov V, Müller TD, Zierler S, Gudermann T. TRPM7 kinase is required for insulin production and compensatory islet responses during obesity. JCI Insight 2023; 8:163397. [PMID: 36574297 PMCID: PMC9977431 DOI: 10.1172/jci.insight.163397] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
Most overweight individuals do not develop diabetes due to compensatory islet responses to restore glucose homeostasis. Therefore, regulatory pathways that promote β cell compensation are potential targets for treatment of diabetes. The transient receptor potential cation channel subfamily M member 7 protein (TRPM7), harboring a cation channel and a serine/threonine kinase, has been implicated in controlling cell growth and proliferation. Here, we report that selective deletion of Trpm7 in β cells disrupted insulin secretion and led to progressive glucose intolerance. We indicate that the diminished insulinotropic response in β cell-specific Trpm7-knockout mice was caused by decreased insulin production because of impaired enzymatic activity of this protein. Accordingly, high-fat-fed mice with a genetic loss of TRPM7 kinase activity displayed a marked glucose intolerance accompanied by hyperglycemia. These detrimental glucoregulatory effects were engendered by reduced compensatory β cell responses because of mitigated protein kinase B (AKT)/ERK signaling. Collectively, our data identify TRPM7 kinase as a potentially novel regulator of insulin synthesis, β cell dynamics, and glucose homeostasis under obesogenic diet.
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Affiliation(s)
- Noushafarin Khajavi
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Andreas Beck
- Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | - Klea Riçku
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Philipp Beyerle
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Katharina Jacob
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Sabrina F. Syamsul
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Anouar Belkacemi
- Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | - Peter S. Reinach
- Wenzhou Medical University, Ophthalmology Department, Wenzhou, China
| | - Pascale C.F. Schreier
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Houssein Salah
- Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | - Tanja Popp
- Bundeswehr Institute of Radiobiology, Munich, Germany
| | - Aaron Novikoff
- Institute of Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Vladimir Chubanov
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Timo D. Müller
- Institute of Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Susanna Zierler
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.,Institute of Pharmacology, Medical Faculty, Johannes Kepler University Linz, Linz, Austria
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.,German Center for Lung Research, Munich, Germany
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Jacobi SF, Khajavi N, Kleinau G, Teumer A, Scheerer P, Homuth G, Völzke H, Wiegand S, Kühnen P, Krude H, Gong M, Raile K, Biebermann H. Evaluation of a rare glucose-dependent insulinotropic polypeptide receptor variant in a patient with diabetes. Diabetes Obes Metab 2019; 21:1168-1176. [PMID: 30784161 DOI: 10.1111/dom.13634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 12/23/2018] [Accepted: 01/04/2019] [Indexed: 12/14/2022]
Abstract
AIMS Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone that augments insulin secretion in pancreatic β-cells via its glucose-dependent insulinotropic polypeptide receptor (GIPR). Recent genome-wide association studies identified a single nucleotide variant (SNV) in the GIPR encoding gene (GIPR), rs1800437, that is associated with obesity and insulin resistance. In the present study, we tested whether GIPR variants contribute to obesity and disturb glucose homeostasis or diabetes in specific patient populations. MATERIALS AND METHODS Exon sequencing of GIPR was performed in 164 children with obesity and insulin resistance and in 80 children with paediatric-onset diabetes of unknown origin. The Study of Health in Pomerania (SHIP) cohort, comprising 8320 adults, was screened for the GIPR variant Arg217Leu. GIPR variants were expressed in COS-7 cells and cAMP production was measured upon stimulation with GIP. Cell surface expression was determined by ELISA. Protein homology modelling of the GIPR variants was performed to extract three-dimensional information of the receptor. RESULTS A heterozygous missense GIPR variant Arg217Leu (rs200485112) was identified in a patient of Asian ancestry. Functional characterization of Arg217Leu revealed reduced surface expression and signalling after GIP challenge. The homology model of the GIPR structure supports the observed functional relevance of Arg217Leu. CONCLUSION In vitro functional studies and protein homology modelling indicate a potential relevance of the GIPR variant Arg217Leu in receptor function. The heterozygous variant displayed partial co-segregation with diabetes. Based on these findings, we suggest that GIPR variants may play a role in disturbed glucose homeostasis and may be of clinical relevance in homozygous patients.
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Affiliation(s)
- Simon F Jacobi
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Institute of Experimental Pediatric Endocrinology, Berlin, Germany
- University Heart Center Freiburg-Bad Krozingen, Department of Congenital Heart Disease and Pediatric Cardiology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Noushafarin Khajavi
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Institute of Experimental Pediatric Endocrinology, Berlin, Germany
| | - Gunnar Kleinau
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Institute of Experimental Pediatric Endocrinology, Berlin, Germany
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health; Institut für Medizinische Physik und Biophysik, Group Protein X-ray Crystallography and Signal Transduction, Berlin, Germany
| | - Alexander Teumer
- Department SHIP/Clinical-Epidemiological Research, Institute for Community Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Patrick Scheerer
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health; Institut für Medizinische Physik und Biophysik, Group Protein X-ray Crystallography and Signal Transduction, Berlin, Germany
| | - Georg Homuth
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine, University Greifswald, Greifswald, Germany
| | - Henry Völzke
- Department SHIP/Clinical-Epidemiological Research, Institute for Community Medicine, University Medicine Greifswald, Greifswald, Germany
- German Center for Diabetes Research (DZD), Site Greifswald, Greifswald, Germany
| | - Susanna Wiegand
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Institute of Experimental Pediatric Endocrinology, Berlin, Germany
| | - Peter Kühnen
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Institute of Experimental Pediatric Endocrinology, Berlin, Germany
| | - Heiko Krude
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Institute of Experimental Pediatric Endocrinology, Berlin, Germany
| | - Maolian Gong
- Experimental and Clinical Research Center (ECRC), a joint collaboration of Charité and Max-Delbrück-Center of Molecular Medicine, Berlin, Germany
| | - Klemens Raile
- Experimental and Clinical Research Center (ECRC), a joint collaboration of Charité and Max-Delbrück-Center of Molecular Medicine, Berlin, Germany
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Department of Paediatric Endocrinology and Diabetology, Berlin, Germany
| | - Heike Biebermann
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Institute of Experimental Pediatric Endocrinology, Berlin, Germany
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Bräunig J, Mergler S, Jyrch S, Hoefig CS, Rosowski M, Mittag J, Biebermann H, Khajavi N. 3-Iodothyronamine Activates a Set of Membrane Proteins in Murine Hypothalamic Cell Lines. Front Endocrinol (Lausanne) 2018; 9:523. [PMID: 30298050 PMCID: PMC6161562 DOI: 10.3389/fendo.2018.00523] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/21/2018] [Indexed: 01/26/2023] Open
Abstract
3-Iodothyronamine (3-T1AM) is an endogenous thyroid hormone metabolite. The profound pharmacological effects of 3-T1AM on energy metabolism and thermal homeostasis have raised interest to elucidate its signaling properties in tissues that pertain to metabolic regulation and thermogenesis. Previous studies identified G protein-coupled receptors (GPCRs) and transient receptor potential channels (TRPs) as targets of 3-T1AM in different cell types. These two superfamilies of membrane proteins are largely expressed in tissue which influences energy balance and metabolism. As the first indication that 3-T1AM virtually modulates the function of the neurons in hypothalamus, we observed that intraperitoneal administration of 50 mg/kg bodyweight of 3-T1AM significantly increased the c-FOS activation in the paraventricular nucleus (PVN) of C57BL/6 mice. To elucidate the underlying mechanism behind this 3-T1AM-induced signalosome, we used three different murine hypothalamic cell lines, which are all known to express PVN markers, GT1-7, mHypoE-N39 (N39) and mHypoE-N41 (N41). Various aminergic GPCRs, which are the known targets of 3-T1AM, as well as numerous members of TRP channel superfamily, are expressed in these cell lines. Effects of 3-T1AM on activation of GPCRs were tested for the two major signaling pathways, the action of Gαs/adenylyl cyclase and Gi/o. Here, we demonstrated that this thyroid hormone metabolite has no significant effect on Gi/o signaling and only a minor effect on the Gαs/adenylyl cyclase pathway, despite the expression of known GPCR targets of 3-T1AM. Next, to test for other potential mechanisms involved in 3-T1AM-induced c-FOS activation in PVN, we evaluated the effect of 3-T1AM on the intracellular Ca2+ concentration and whole-cell currents. The fluorescence-optic measurements showed a significant increase of intracellular Ca2+ concentration in the three cell lines in the presence of 10 μM 3-T1AM. Furthermore, this thyroid hormone metabolite led to an increase of whole-cell currents in N41 cells. Interestingly, the TRPM8 selective inhibitor (10 μM AMTB) reduced the 3-T1AM stimulatory effects on cytosolic Ca2+ and whole-cell currents. Our results suggest that the profound pharmacological effects of 3-T1AM on selected brain nuclei of murine hypothalamus, which are known to be involved in energy metabolism and thermoregulation, might be partially attributable to TRP channel activation in hypothalamic cells.
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Affiliation(s)
- Julia Bräunig
- Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Institute of Experimental Pediatric Endocrinology, Berlin, Germany
| | - Stefan Mergler
- Klinik für Augenheilkunde, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Sabine Jyrch
- Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Institute of Experimental Pediatric Endocrinology, Berlin, Germany
| | - Carolin S. Hoefig
- Institute of Experimental Endocrinology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Department of Cell & Molecular Biology, Karolinska Instituet, Stockholm, Sweden
| | - Mark Rosowski
- Department Medical Biotechnology, Institute of Biotechnology, Technical University of Berlin, Berlin, Germany
| | - Jens Mittag
- Department of Cell & Molecular Biology, Karolinska Instituet, Stockholm, Sweden
- University of Lübeck – Center of Brain Behavior and Metabolism, Lübeck, Germany
| | - Heike Biebermann
- Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Institute of Experimental Pediatric Endocrinology, Berlin, Germany
| | - Noushafarin Khajavi
- Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Institute of Experimental Pediatric Endocrinology, Berlin, Germany
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Türker E, Garreis F, Khajavi N, Reinach PS, Joshi P, Brockmann T, Lucius A, Ljubojevic N, Turan E, Cooper D, Schick F, Reinholz R, Pleyer U, Köhrle J, Mergler S. Vascular Endothelial Growth Factor (VEGF) Induced Downstream Responses to Transient Receptor Potential Vanilloid 1 (TRPV1) and 3-Iodothyronamine (3-T 1AM) in Human Corneal Keratocytes. Front Endocrinol (Lausanne) 2018; 9:670. [PMID: 30524369 PMCID: PMC6262029 DOI: 10.3389/fendo.2018.00670] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [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: 06/12/2018] [Accepted: 10/26/2018] [Indexed: 12/30/2022] Open
Abstract
This study was undertaken to determine if crosstalk among the transient receptor potential (TRP) melastatin 8 (TRPM8), TRP vanilloid 1 (TRPV1), and vascular endothelial growth factor (VEGF) receptor triad modulates VEGF-induced Ca2+ signaling in human corneal keratocytes. Using RT-PCR, qPCR and immunohistochemistry, we determined TRPV1 and TRPM8 gene and protein coexpression in a human corneal keratocyte cell line (HCK) and human corneal cross sections. Fluorescence Ca2+ imaging using both a photomultiplier and a single cell digital imaging system as well as planar patch-clamping measured relative intracellular Ca2+ levels and underlying whole-cell currents. The TRPV1 agonist capsaicin increased both intracellular Ca2+ levels and whole-cell currents, while the antagonist capsazepine (CPZ) inhibited them. VEGF-induced Ca2+ transients and rises in whole-cell currents were suppressed by CPZ, whereas a selective TRPM8 antagonist, AMTB, increased VEGF signaling. In contrast, an endogenous thyroid hormone-derived metabolite 3-Iodothyronamine (3-T1AM) suppressed increases in the VEGF-induced current. The TRPM8 agonist menthol increased the currents, while AMTB suppressed this response. The VEGF-induced increases in Ca2+ influx and their underlying ionic currents stem from crosstalk between VEGFR and TRPV1, which can be impeded by 3-T1AM-induced TRPM8 activation. Such suppression in turn blocks VEGF-induced TRPV1 activation. Therefore, crosstalk between TRPM8 and TRPV1 inhibits VEGFR-induced activation of TRPV1.
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Affiliation(s)
- Ersal Türker
- Klinik für Augenheilkunde, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Fabian Garreis
- Department of Functional and Clinical Anatomy, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Noushafarin Khajavi
- Institut für Experimentelle Pädiatrische Endokrinologie, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Walter Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Peter S. Reinach
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Pooja Joshi
- Klinik für Augenheilkunde, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Tobias Brockmann
- Klinik für Augenheilkunde, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Berlin Institute of Health (BIH), Berlin, Germany
| | - Alexander Lucius
- Klinik für Augenheilkunde, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Nina Ljubojevic
- Klinik für Augenheilkunde, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Elizabeth Turan
- Klinik für Augenheilkunde, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Drew Cooper
- Klinik für Augenheilkunde, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Felix Schick
- Klinik für Augenheilkunde, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Rob Reinholz
- Klinik für Augenheilkunde, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Uwe Pleyer
- Klinik für Augenheilkunde, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Josef Köhrle
- Institut für Experimentelle Endokrinologie, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Stefan Mergler
- Klinik für Augenheilkunde, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- *Correspondence: Stefan Mergler
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7
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Fischer J, Kleinau G, Rutz C, Zwanziger D, Khajavi N, Müller A, Rehders M, Brix K, Worth CL, Führer D, Krude H, Wiesner B, Schülein R, Biebermann H. Evidence of G-protein-coupled receptor and substrate transporter heteromerization at a single molecule level. Cell Mol Life Sci 2017; 75:2227-2239. [PMID: 29290039 DOI: 10.1007/s00018-017-2728-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 11/17/2017] [Accepted: 12/11/2017] [Indexed: 10/18/2022]
Abstract
G-protein-coupled receptors (GPCRs) can constitute complexes with non-GPCR integral membrane proteins, while such interaction has not been demonstrated at a single molecule level so far. We here investigated the potential interaction between the thyrotropin receptor (TSHR) and the monocarboxylate transporter 8 (MCT8), a member of the major facilitator superfamily (MFS), using fluorescence cross-correlation spectroscopy (FCCS). Both the proteins are expressed endogenously on the basolateral plasma membrane of the thyrocytes and are involved in stimulation of thyroid hormone production and release. Indeed, we demonstrate strong interaction between both the proteins which causes a suppressed activation of Gq/11 by TSH-stimulated TSHR. Thus, we provide not only evidence for a novel interaction between the TSHR and MCT8, but could also prove this interaction on a single molecule level. Moreover, this interaction forces biased signaling at the TSHR. These results are of general interest for both the GPCR and the MFS research fields.
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Affiliation(s)
- Jana Fischer
- Institut für Experimentelle Pädiatrische Endokrinologie, Charité - Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Gunnar Kleinau
- Institut für Experimentelle Pädiatrische Endokrinologie, Charité - Universitätsmedizin Berlin, 13353, Berlin, Germany
- Group Protein X-ray Crystallography and Signal Transduction, Institute of Medical Physics and Biophysics, Charité - Universitätsmedizin Berlin, 10117, Berlin, Germany
| | - Claudia Rutz
- Protein Trafficking Group, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany
| | - Denise Zwanziger
- Division of Laboratory Research, Department of Endocrinology, Diabetology and Metabolism, University Hospital Essen, University Duisburg-Essen, 45147, Essen, Germany
| | - Noushafarin Khajavi
- Institut für Experimentelle Pädiatrische Endokrinologie, Charité - Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Anne Müller
- Institut für Experimentelle Pädiatrische Endokrinologie, Charité - Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Maren Rehders
- Department of Life Sciences and Chemistry, Jacobs University Bremen, 28759, Bremen, Germany
| | - Klaudia Brix
- Department of Life Sciences and Chemistry, Jacobs University Bremen, 28759, Bremen, Germany
| | - Catherine L Worth
- Structural Bioinformatics and Protein Design Group, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, 13125, Berlin, Germany
| | - Dagmar Führer
- Division of Laboratory Research, Department of Endocrinology, Diabetology and Metabolism, University Hospital Essen, University Duisburg-Essen, 45147, Essen, Germany
| | - Heiko Krude
- Institut für Experimentelle Pädiatrische Endokrinologie, Charité - Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Burkhard Wiesner
- Protein Trafficking Group, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany
- Cellular Imaging Group, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, 13125, Berlin, Germany
| | - Ralf Schülein
- Protein Trafficking Group, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany.
| | - Heike Biebermann
- Institut für Experimentelle Pädiatrische Endokrinologie, Charité - Universitätsmedizin Berlin, 13353, Berlin, Germany.
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8
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Buonocore F, Kühnen P, Suntharalingham JP, Del Valle I, Digweed M, Stachelscheid H, Khajavi N, Didi M, Brady AF, Blankenstein O, Procter AM, Dimitri P, Wales JK, Ghirri P, Knöbl D, Strahm B, Erlacher M, Wlodarski MW, Chen W, Kokai GK, Anderson G, Morrogh D, Moulding DA, McKee SA, Niemeyer CM, Grüters A, Achermann JC. Somatic mutations and progressive monosomy modify SAMD9-related phenotypes in humans. J Clin Invest 2017; 127:1700-1713. [PMID: 28346228 PMCID: PMC5409795 DOI: 10.1172/jci91913] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 01/26/2017] [Indexed: 12/24/2022] Open
Abstract
It is well established that somatic genomic changes can influence phenotypes in cancer, but the role of adaptive changes in developmental disorders is less well understood. Here we have used next-generation sequencing approaches to identify de novo heterozygous mutations in sterile α motif domain-containing protein 9 (SAMD9, located on chromosome 7q21.2) in 8 children with a multisystem disorder termed MIRAGE syndrome that is characterized by intrauterine growth restriction (IUGR) with gonadal, adrenal, and bone marrow failure, predisposition to infections, and high mortality. These mutations result in gain of function of the growth repressor product SAMD9. Progressive loss of mutated SAMD9 through the development of monosomy 7 (-7), deletions of 7q (7q-), and secondary somatic loss-of-function (nonsense and frameshift) mutations in SAMD9 rescued the growth-restricting effects of mutant SAMD9 proteins in bone marrow and was associated with increased length of survival. However, 2 patients with -7 and 7q- developed myelodysplastic syndrome, most likely due to haploinsufficiency of related 7q21.2 genes. Taken together, these findings provide strong evidence that progressive somatic changes can occur in specific tissues and can subsequently modify disease phenotype and influence survival. Such tissue-specific adaptability may be a more common mechanism modifying the expression of human genetic conditions than is currently recognized.
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Affiliation(s)
- Federica Buonocore
- Genetics and Genomic Medicine, University College London (UCL) Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Peter Kühnen
- Institute of Experimental Pediatric Endocrinology and Department of Pediatric Endocrinology, Charité, Berlin, Germany
| | - Jenifer P. Suntharalingham
- Genetics and Genomic Medicine, University College London (UCL) Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Ignacio Del Valle
- Genetics and Genomic Medicine, University College London (UCL) Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Martin Digweed
- Department of Human and Medical Genetics, Charité, Berlin, Germany
| | - Harald Stachelscheid
- Berlin Institute of Health, Berlin, Germany, and Berlin-Brandenburg Centrum for Regenerative Therapies, Charité, Berlin, Germany
| | - Noushafarin Khajavi
- Institute of Experimental Pediatric Endocrinology and Department of Pediatric Endocrinology, Charité, Berlin, Germany
| | - Mohammed Didi
- Department of Paediatric Endocrinology, Alder Hey Children’s NHS Foundation Trust, Liverpool, United Kingdom
| | - Angela F. Brady
- North West Thames Regional Genetics Service, Northwick Park Hospital, Harrow, United Kingdom
| | - Oliver Blankenstein
- Institute of Experimental Pediatric Endocrinology and Department of Pediatric Endocrinology, Charité, Berlin, Germany
| | - Annie M. Procter
- Institute of Medical Genetics, University Hospital of Wales, Cardiff, United Kingdom
| | - Paul Dimitri
- Academic Unit of Child Health, University of Sheffield, Sheffield, United Kingdom
| | - Jerry K.H. Wales
- Department of Endocrinology, Children’s Health Queensland Clinical Unit, University of Queensland, Brisbane, Australia
| | - Paolo Ghirri
- Department of Neonatology, University of Pisa, Pisa, Italy
| | | | - Brigitte Strahm
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Miriam Erlacher
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- German Cancer Consortium (DKTK) and German Research Center (DKFZ), Heidelberg, Germany
| | - Marcin W. Wlodarski
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- German Cancer Consortium (DKTK) and German Research Center (DKFZ), Heidelberg, Germany
| | - Wei Chen
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - George K. Kokai
- Department of Paediatric Histopathology, Alder Hey Children’s NHS Foundation Trust, Liverpool, United Kingdom
| | - Glenn Anderson
- Histopathology Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Deborah Morrogh
- North East Thames Regional Genetics Laboratory Service, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Dale A. Moulding
- Developmental Biology and Cancer, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Shane A. McKee
- Department of Genetic Medicine, Belfast City Hospital, Belfast, United Kingdom
| | - Charlotte M. Niemeyer
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- German Cancer Consortium (DKTK) and German Research Center (DKFZ), Heidelberg, Germany
| | - Annette Grüters
- Institute of Experimental Pediatric Endocrinology and Department of Pediatric Endocrinology, Charité, Berlin, Germany
| | - John C. Achermann
- Genetics and Genomic Medicine, University College London (UCL) Great Ormond Street Institute of Child Health, London, United Kingdom
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9
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Skrzypski M, Billert M, Mergler S, Khajavi N, Nowak KW, Strowski MZ. Role of TRPV channels in regulating various pancreatic β-cell functions: Lessons from in vitro studies. Biosci Trends 2017; 11:9-15. [PMID: 28154245 DOI: 10.5582/bst.2016.01226] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Pancreatic β-cell functions are regulated by a variety of endogenous and exogenous factors. Calcium is one of the most potent triggers of β-cell growth, insulin production and exocytosis. Recently, others and we showed that TRPV channels are expressed in insulin producing cell lines and/or primary β-cells. These channels modulate calcium ions, insulin secretion and cell proliferation. Besides the classical roles of TRPV channels in the sensory system, there are also novel functions described in non-excitable cells such as in insulin-producing β-cells. This review summarises the current knowledge about the expression and the role of TRPV channels in controlling β-cell functions based upon studies performed in isolated primary β-cells as well as permanent β-cell models.
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Affiliation(s)
- Marek Skrzypski
- Department of Animal Physiology and Biochemistry, Poznań University of Life Sciences
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10
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Khajavi N, Biebermann H, Tschöp M, DiMarchi R. Treatment of Diabetes and Obesity by Rationally Designed Peptide Agonists Functioning at Multiple Metabolic Receptors. Endocr Dev 2017; 32:165-182. [PMID: 28873389 DOI: 10.1159/000475737] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
Obesity and its comorbidities such as type 2 diabetes constitute major worldwide health threats, and the identification of an effective medical intervention has emerged as a global priority. The limited effectiveness of historical, anti-obesity treatments is commonly attributed to the complexity of the disease and the redundancy of metabolic regulatory mechanisms that sustain body weight. At the forefront of obesity research is the development of combinational drug therapies that simultaneously target multiple regulatory pathways, which promote dysfunctional metabolism. Recently, molecularly crafted unimolecular "multi-agonism" of balanced activity at 3 key receptors involved in metabolism and specifically the glucagon-like peptide (GLP)-1 receptor, glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon receptor was reported as superior to conventional monoagonist therapy. These mixed peptide agonists are designed to pharmacologically integrate the insulinotropic and anorexigenic effects of GLP-1, the thermogenic and lipolytic activities of glucagon, and the insulinotropic and insulin sensitizing properties of GIP. The molecular mechanism of these purposefully promiscuous ligands is not completely understood, however, recent studies in pancreatic beta cells point to the prospect of a complex signaling network that can magnify the signaling of multi-agonist ligands. The activation of this signalosome might explain the additional therapeutic benefit inherent to simultaneous cellular activation through multiple metabolic receptors.
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11
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Schanze N, Jacobi SF, Rijntjes E, Mergler S, Del Olmo M, Hoefig CS, Khajavi N, Lehmphul I, Biebermann H, Mittag J, Köhrle J. 3-Iodothyronamine Decreases Expression of Genes Involved in Iodide Metabolism in Mouse Thyroids and Inhibits Iodide Uptake in PCCL3 Thyrocytes. Thyroid 2017; 27:11-22. [PMID: 27788620 DOI: 10.1089/thy.2016.0182] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND 3-Iodothyronamine (3-T1AM) is an endogenous decarboxylated thyroid hormone (TH) metabolite. Pharmacological doses of 3-T1AM decrease heart rate, body temperature, and metabolic rate in rodents-effects that are contrary to classic TH excess. Furthermore, a single dose of 3-T1AM was shown to suppress the hypothalamic-pituitary-thyroid (HPT) axis in rats. It was hypothesized that 3-T1AM might play a role in the fine-tuning of TH action and might have a direct regulatory effect on the thyroid gland. METHODS This study tested whether repeated 3-T1AM treatment interfered with thyroid function and the HPT axis in mice. Therefore, male C57BL/6 mice were intraperitoneally injected with 5 mg/kg of 3-T1AM or vehicle daily for seven days. Additionally, the effects of 3-T1AM on the differentiated rat thyrocyte cell line PCCL3 were analyzed. RESULTS Repeated administration of 3-T1AM decreased thyroidal mRNA content of the sodium iodide symporter (Nis), thyroglobulin, and pendrin in mice. No interference with the HPT axis was observed, as determined by unaltered pituitary mRNA levels of triiodothyronine-responsive genes, including thyrotropin subunit β. Furthermore, 3-T1AM treatment did not change transcript levels of hepatic triiodothyronine-responsive genes, such as deiodinase 1. In line with this, serum TH concentrations were not changed after the treatment period of seven days. In concordance with the in vivo findings, 3-T1AM decreased the thyrotropin-dependent expression of Nis and functional iodide uptake in PCCL3 cells in vitro. Additionally, uptake and metabolism of 3-T1AM by PCCL3 cells was observed, as well as 3-T1AM-dependent changes in intracellular Ca2+ concentration that might be involved in mediating the reported effects. CONCLUSIONS In conclusion, 3-T1AM application decreased expression of selected TH synthesis genes by acting directly on the thyroid gland, and it might therefore affect TH synthesis without involvement of the HPT axis.
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Affiliation(s)
- Nancy Schanze
- 1 Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin , Berlin, Germany
- 2 Department of Cell and Molecular Biology, Karolinska Institutet , Stockholm, Sweden
| | - Simon Friedrich Jacobi
- 2 Department of Cell and Molecular Biology, Karolinska Institutet , Stockholm, Sweden
- 3 Institut für Experimentelle Pädiatrische Endokrinologie, Charité-Universitätsmedizin Berlin , Berlin, Germany
| | - Eddy Rijntjes
- 1 Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin , Berlin, Germany
| | - Stefan Mergler
- 4 Experimentelle Ophthalmologie, Charité-Universitätsmedizin Berlin , Berlin, Germany
| | - Marta Del Olmo
- 1 Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin , Berlin, Germany
| | - Carolin Stephanie Hoefig
- 1 Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin , Berlin, Germany
- 2 Department of Cell and Molecular Biology, Karolinska Institutet , Stockholm, Sweden
| | - Noushafarin Khajavi
- 3 Institut für Experimentelle Pädiatrische Endokrinologie, Charité-Universitätsmedizin Berlin , Berlin, Germany
| | - Ina Lehmphul
- 1 Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin , Berlin, Germany
| | - Heike Biebermann
- 3 Institut für Experimentelle Pädiatrische Endokrinologie, Charité-Universitätsmedizin Berlin , Berlin, Germany
| | - Jens Mittag
- 2 Department of Cell and Molecular Biology, Karolinska Institutet , Stockholm, Sweden
- 5 Molecular Endocrinology, Universitätsklinikum Schleswig-Holstein , Medizinische Klinik I/CBBM, Lübeck, Germany
| | - Josef Köhrle
- 1 Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin , Berlin, Germany
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12
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Khajavi N, Mergler S, Biebermann H. 3-Iodothyronamine, a Novel Endogenous Modulator of Transient Receptor Potential Melastatin 8? Front Endocrinol (Lausanne) 2017; 8:198. [PMID: 28861042 PMCID: PMC5561014 DOI: 10.3389/fendo.2017.00198] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 07/28/2017] [Indexed: 11/22/2022] Open
Abstract
The decarboxylated and deiodinated thyroid hormone (TH) derivative, 3-iodothyronamine (3-T1AM), is suggested to be involved in energy metabolism and thermoregulation. G protein-coupled receptors (GPCRs) are known as the main targets for 3-T1AM; however, transient receptor potential channels (TRPs) were also recently identified as new targets of 3-T1AM. This article reviews the current knowledge of a putative novel role of 3-T1AM in the modulation of TRPs. Specifically, the TRP melastatin 8 (TRPM8) was identified as a target of 3-T1AM in different cell types including neoplastic cells, whereby 3-T1AM significantly increased cytosolic Ca2+ through TRPM8 activation. Similarly, the β-adrenergic receptor is involved in 3-T1AM-induced Ca2+ influx. Therefore, it has been suggested that 3-T1AM-induced Ca2+ mobilization might be due to β-adrenergic receptor/TRPM8 channel interaction, which adds to the complexity of GPCR regulation by TRPs. It has been revealed that TRPM8 activation leads to a decline in TRPV1 activity, which may be of therapeutic benefit in clinical circumstances such as treatment of TRPV1-mediated inflammatory hyperalgesia, colitis, and dry eye syndrome. This review also summarizes the inverse association between changes in TRPM8 and TRPV1 activity after 3-T1AM stimulation. This finding prompted further detailed investigations of the interplay between 3-T1AM and the GPCR/TRPM8 axis and indicated the probability of additional GPCR/TRP constellations that are modulated by this TH derivative.
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Affiliation(s)
- Noushafarin Khajavi
- Institute for Experimental Pediatric Endocrinology, Charité University of Medicine Berlin, Berlin, Germany
- *Correspondence: Noushafarin Khajavi,
| | - Stefan Mergler
- Department of Ophthalmology, Charité University of Medicine Berlin, Berlin, Germany
| | - Heike Biebermann
- Institute for Experimental Pediatric Endocrinology, Charité University of Medicine Berlin, Berlin, Germany
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13
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Skrzypski M, Khajavi N, Mergler S, Billert M, Szczepankiewicz D, Wojciechowicz T, Nowak KW, Strowski MZ. Orexin A modulates INS-1E cell proliferation and insulin secretion via extracellular signal-regulated kinase and transient receptor potential channels. J Physiol Pharmacol 2016; 67:643-652. [PMID: 28011945] [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] [Received: 05/30/2016] [Accepted: 10/14/2016] [Indexed: 06/06/2023]
Abstract
Orexins A (OXA) and B (OXB) control energy homeostasis by regulating food intake, energy expenditure and sleep-wake cycle. Several studies showed that OXA stimulates insulin secretion and proliferation of beta cells. However, mechanisms of action are still not well understood. Here, we investigated whether ERK and transient receptor potential channels (TRPs) play a role in mediating the effect of OXA on cell growth, insulin production, and secretion using the established INS-1E cell line. Cell proliferation was measured using BrdU assay. Insulin mRNA expression was detected by real-time PCR. Insulin secretion was assessed using ELISA. Intracellular calcium levels were measured using fluorescence calcium imaging (fura-2/AM). Extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation was detected by Western blot. TRP channel activity was blocked by lanthanum (III) chloride (La3+; 100 - 300 μM) or ruthenium red (RuR; 10 μM). OXA (100 nM) stimulated INS-1E cell proliferation, insulin secretion, intracellular Ca2+ concentration and ERK1/2 phosphorylation, without changing insulin mRNA expression. Inhibition of ERK1/2 by 10 μM U0126 attenuated OXA-stimulated INS-1E cell proliferation. Blockade of TRP channel activity by La3+ or RuR rendered OXA ineffective at modulating Ca2+ regulation and insulin release. In contrast, the L-type channel blocker nifedipine (10 μM) failed to affect OXA-stimulated insulin release. Taken together, OXA increases INS-1E cell proliferation via ERK1/2-dependent mechanism. Furthermore, OXA stimulates insulin secretion from INS-1E cells. TRPs are relevant for OXA-stimulated insulin secretion and intracellular calcium regulation.
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Affiliation(s)
- M Skrzypski
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland.
| | - N Khajavi
- Institute for Experimental Pediatric Endocrinology, Charite, University-Medicine Berlin, Berlin, Germany
| | - S Mergler
- Department of Ophthalmology, Charite University Medicine Berlin, Berlin, Germany
| | - M Billert
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland
| | - D Szczepankiewicz
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland
| | - T Wojciechowicz
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland
| | - K W Nowak
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland
| | - M Z Strowski
- Department of Hepatology and Gastroenterology and Interdisciplinary Centre of Metabolism-Endocrinology, Diabetes and Metabolism, Charite-University Medicine Berlin, Berlin, Germany
- Department of Internal Medicine-Gastroenterology, Park-Klinik Weissensee, Berlin, Germany
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Garreis F, Schröder A, Reinach PS, Zoll S, Khajavi N, Dhandapani P, Lucius A, Pleyer U, Paulsen F, Mergler S. Upregulation of Transient Receptor Potential Vanilloid Type-1 Channel Activity and Ca2+Influx Dysfunction in Human Pterygial Cells. ACTA ACUST UNITED AC 2016; 57:2564-77. [DOI: 10.1167/iovs.16-19170] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Fabian Garreis
- Department of Anatomy II Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Antje Schröder
- Department of Anatomy II Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Peter S. Reinach
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, People's Republic of China
| | - Stefanie Zoll
- Department of Ophthalmology, Charité–Universitätsmedizin Berlin, Campus Virchow-Hospital, Berlin, Germany
| | - Noushafarin Khajavi
- Department of Ophthalmology, Charité–Universitätsmedizin Berlin, Campus Virchow-Hospital, Berlin, Germany
| | - Priyavathi Dhandapani
- Department of Gastroenterology, Charité–Universitätsmedizin Berlin, Campus Virchow-Hospital, Berlin, Germany
| | - Alexander Lucius
- Department of Ophthalmology, Charité–Universitätsmedizin Berlin, Campus Virchow-Hospital, Berlin, Germany
| | - Uwe Pleyer
- Department of Ophthalmology, Charité–Universitätsmedizin Berlin, Campus Virchow-Hospital, Berlin, Germany
| | - Friedrich Paulsen
- Department of Anatomy II Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Stefan Mergler
- Department of Ophthalmology, Charité–Universitätsmedizin Berlin, Campus Virchow-Hospital, Berlin, Germany
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15
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Lucius A, Khajavi N, Reinach PS, Köhrle J, Dhandapani P, Huimann P, Ljubojevic N, Grötzinger C, Mergler S. 3-Iodothyronamine increases transient receptor potential melastatin channel 8 (TRPM8) activity in immortalized human corneal epithelial cells. Cell Signal 2015; 28:136-147. [PMID: 26689735 DOI: 10.1016/j.cellsig.2015.12.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [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: 07/27/2015] [Revised: 11/25/2015] [Accepted: 12/08/2015] [Indexed: 10/22/2022]
Abstract
3-Iodothyronamine (3T1AM) is an endogenous thyroid hormone metabolite that interacts with the human trace amine-associated receptor 1 (hTAAR1), a G-protein-coupled receptor, to induce numerous physiological responses including dose-dependent body temperature lowering in rodents. 3T1AM also directly activates cold-sensitive transient receptor potential melastatin 8 (TRPM8) channels in human conjunctival epithelial cells (HCjEC) at constant temperature as well as reducing rises in IL-6 release induced by transient receptor potential vanilloid 1 (TRPV1) activation by capsaicin (CAP). Here, we describe that 3T1AM-induced TRPM8 activation suppresses through crosstalk TRPV1 activation in immortalized human corneal epithelial cells (HCEC). RT-PCR and immunofluorescent staining identified TRPM8 gene and protein expression. Increases in Ca(2+) influx induced by the TRPM8 agonists either 3T1AM (0.1-10 μM), menthol (500 μM), icilin (15-60 μM) or temperature lowering (either <17°C or >17°C) were all blocked by 10-20 μM BCTC, a mixed TRPV1/TRPM8 antagonist. BCTC blocked 3T1AM-induced recombinant TRPM8 activation of Ca(2+) transients in an osteosarcoma heterologous expression system. The effects of BCTC in HCEC were attributable to selective TRPM8 inhibition since whole-cell patch-clamp currents underlying Ca(2+) rises induced by 20 μM CAP were BCTC insensitive. On the other hand, Ca(2+) transients induced by activating TRPV1 with either CAP or a hyperosmolar medium were suppressed during exposure to either 1 μM 3T1AM or 15 μM icilin. All of these modulatory effects on intracellular Ca(2+) regulation induced by the aforementioned agents were attributable to changes in underlying inward and outward current. Taken together, TRPM8 activation by 3T1AM markedly attenuates and even eliminates hyperosmolar and CAP induced TRPV1 activation through crosstalk.
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Affiliation(s)
- Alexander Lucius
- Klinik für Augenheilkunde, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Noushafarin Khajavi
- Klinik für Augenheilkunde, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Peter S Reinach
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou 325027, PR China
| | - Josef Köhrle
- Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Priyavathi Dhandapani
- Gastroenterology, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Philipp Huimann
- Klinik für Augenheilkunde, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Nina Ljubojevic
- Klinik für Augenheilkunde, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Carsten Grötzinger
- Gastroenterology, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Stefan Mergler
- Klinik für Augenheilkunde, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
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Mergler S, Khajavi N, Pleyer U. TRP-Kanäle an der Augenoberfläche – therapeutische Relevanz? Klin Monbl Augenheilkd 2015. [DOI: 10.1055/s-0035-1569174] [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: 10/22/2022]
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17
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Dinter J, Khajavi N, Mühlhaus J, Wienchol CL, Cöster M, Hermsdorf T, Stäubert C, Köhrle J, Schöneberg T, Kleinau G, Mergler S, Biebermann H. The Multitarget Ligand 3-Iodothyronamine Modulates β-Adrenergic Receptor 2 Signaling. Eur Thyroid J 2015; 4:21-9. [PMID: 26601070 PMCID: PMC4640289 DOI: 10.1159/000381801] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 03/19/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND 3-Iodothyronamine (3-T1AM), a signaling molecule with structural similarities to thyroid hormones, induces numerous physiological responses including reversible body temperature decline. One target of 3-T1AM is the trace amine-associated receptor 1 (TAAR1), which is a member of the rhodopsin-like family of G protein-coupled receptors (GPCRs). Interestingly, the effects of 3-T1AM remain detectable in TAAR1 knockout mice, suggesting further targets for 3-T1AM such as adrenergic receptors. Therefore, we evaluated whether β-adrenergic receptor 1 (ADRB1) and 2 (ADRB2) signaling is affected by 3-T1AM in HEK293 cells and in human conjunctival epithelial cells (IOBA-NHC), where these receptors are highly expressed endogenously. METHODS A label-free EPIC system for prescreening the 3-T1AM-induced effects on ADRB1 and ADRB2 in transfected HEK293 cells was used. In addition, ADRB1 and ADRB2 activation was analyzed using a cyclic AMP assay and a MAPK reporter gene assay. Finally, fluorescence Ca(2+) imaging was utilized to delineate 3-T1AM-induced Ca(2+) signaling. RESULTS 3-T1AM (10(-5)-10(-10)M) enhanced isoprenaline-induced ADRB2-mediated Gs signaling but not that of ADRB1-mediated signaling. MAPK signaling remained unaffected for both receptors. In IOBA-NHC cells, norepinephrine-induced Ca(2+) influxes were blocked by the nonselective ADRB blocker timolol (10 µM), indicating that ADRBs are most likely linked with Ca(2+) channels. Notably, timolol was also found to block 3-T1AM (10(-5)M)-induced Ca(2+) influx. CONCLUSIONS The presented data support that 3-T1AM directly modulates β-adrenergic receptor signaling. The relationship between 3-T1AM and β-adrenergic signaling also reveals a potential therapeutic value for suppressing Ca(2+) channel-mediated inflammation processes, occurring in eye diseases such as conjunctivitis.
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Affiliation(s)
- Juliane Dinter
- Institut für Experimentelle Pädiatrische Endokrinologie, Berlin, Germany
| | - Noushafarin Khajavi
- Department of Ophthalmology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Jessica Mühlhaus
- Institut für Experimentelle Pädiatrische Endokrinologie, Berlin, Germany
| | | | - Maxi Cöster
- Institut für Biochemie, Molekulare Biochemie, Medizinische Fakultät, University of Leipzig, Leipzig, Germany
| | - Thomas Hermsdorf
- Institut für Biochemie, Molekulare Biochemie, Medizinische Fakultät, University of Leipzig, Leipzig, Germany
| | - Claudia Stäubert
- Institut für Biochemie, Molekulare Biochemie, Medizinische Fakultät, University of Leipzig, Leipzig, Germany
| | - Josef Köhrle
- Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Torsten Schöneberg
- Institut für Biochemie, Molekulare Biochemie, Medizinische Fakultät, University of Leipzig, Leipzig, Germany
| | - Gunnar Kleinau
- Institut für Experimentelle Pädiatrische Endokrinologie, Berlin, Germany
| | - Stefan Mergler
- Department of Ophthalmology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Heike Biebermann
- Institut für Experimentelle Pädiatrische Endokrinologie, Berlin, Germany
- *Heike Biebermann, Institut für Experimentelle Pädiatrische Endokrinologie, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, DE-13353 Berlin (Germany), E-Mail , Stefan Mergler, Department of Ophthalmology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, DE-13353 Berlin (Germany), E-Mail
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Khajavi N, Reinach PS, Slavi N, Skrzypski M, Lucius A, Strauß O, Köhrle J, Mergler S. Thyronamine induces TRPM8 channel activation in human conjunctival epithelial cells. Cell Signal 2014; 27:315-25. [PMID: 25460045 DOI: 10.1016/j.cellsig.2014.11.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 10/31/2014] [Accepted: 11/12/2014] [Indexed: 11/16/2022]
Abstract
3-Iodothyronamine (T1AM), an endogenous thyroid hormone (TH) metabolite, induces numerous responses including a spontaneously reversible body temperature decline. As such an effect is associated in the eye with increases in basal tear flow and thermosensitive transient receptor potential melastatin 8 (TRPM8) channel activation, we determined in human conjunctival epithelial cells (IOBA-NHC) if T1AM also acts as a cooling agent to directly affect TRPM8 activation at a constant temperature. RT-PCR and quantitative real-time PCR (qPCR) along with immunocytochemistry probed for TRPM8 gene and protein expression whereas functional activity was evaluated by comparing the effects of T1AM with those of TRPM8 mediators on intracellular Ca(2+) ([Ca(2+)]i) and whole-cell currents. TRPM8 gene and protein expression was evident and icilin (20μM), a TRPM8 agonist, increased Ca(2+) influx as well as whole-cell currents whereas BCTC (10μM), a TRPM8 antagonist, suppressed these effects. Similarly, either temperature lowering below 23°C or T1AM (1μM) induced Ca(2+) transients that were blocked by this antagonist. TRPM8 activation by both 1µM T1AM and 20μM icilin prevented capsaicin (CAP) (20μM) from inducing increases in Ca(2+) influx through TRP vanilloid 1 (TRPV1) activation, whereas BCTC did not block this response. CAP (20μM) induced a 2.5-fold increase in IL-6 release whereas during exposure to 20μM capsazepine this rise was completely blocked. Similarly, T1AM (1μM) prevented this response. Taken together, T1AM like icilin is a cooling agent since they both directly elicit TRPM8 activation at a constant temperature. Moreover, there is an inverse association between changes in TRPM8 and TRPV1 activity since these cooling agents blocked both CAP-induced TRPV1 activation and downstream rises in IL-6 release.
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Affiliation(s)
- Noushafarin Khajavi
- Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Klinik für Augenheilkunde, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Peter S Reinach
- Biological Sciences, SUNY College of Optometry, New York, NY 10036, USA; School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou 325027, PR China
| | - Nefeli Slavi
- Biological Sciences, SUNY College of Optometry, New York, NY 10036, USA
| | - Marek Skrzypski
- Department of Animal Physiology and Biochemistry, Poznań University of Life Sciences, 60-637 Poznań, Poland
| | - Alexander Lucius
- Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Klinik für Augenheilkunde, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Olaf Strauß
- Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Klinik für Augenheilkunde, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Josef Köhrle
- Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Stefan Mergler
- Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Klinik für Augenheilkunde, Augustenburger Platz 1, D-13353 Berlin, Germany.
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Khajavi N, Reinach PS, Skrzypski M, Lude A, Mergler S. L-carnitine reduces in human conjunctival epithelial cells hypertonic-induced shrinkage through interacting with TRPV1 channels. Cell Physiol Biochem 2014; 34:790-803. [PMID: 25170901 DOI: 10.1159/000363043] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Ocular surface health depends on conjunctival epithelial (HCjE) layer integrity since it protects against pathogenic infiltration and contributes to tissue hydration maintenance. As the same increases in tear film hyperosmolarity described in dry eye disease can increase corneal epithelial transient receptor potential vanilloid type-1 (TRPV1) channel activity, we evaluated its involvement in mediating an osmoprotective effect by L-carnitine against such stress. METHODS Using siRNA gene silencing, Ca(2+) imaging, planar patch-clamping and relative cell volume measurements, we determined if the protective effects of this osmolyte stem from its interaction with TRPV1. RESULTS TRPV1 activation by capsaicin (CAP) and an increase in osmolarity to ≈ 450 mOsM both induced increases in Ca(2+) levels. In contrast, blocking TRPV1 activation with capsazepine (CPZ) fully reversed this response. Similarly, L-carnitine (1 mM) also reduced underlying whole-cell currents. In calcein-AM loaded cells, hypertonic-induced relative cell volume shrinkage was fully blocked during exposure to L-carnitine. On the other hand, in TRPV1 gene-silenced cells, this protective effect by L-carnitine was obviated. CONCLUSION The described L-carnitine osmoprotective effect is elicited through suppression of hypertonic-induced TRPV1 activation leading to increases in L-carnitine uptake through a described Na(+)-dependent L-carnitine transporter.
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Affiliation(s)
- Noushafarin Khajavi
- Charité - Universitätsmedizin Berlin, Campus Virchow-Clinic, Department of Ophthalmology, Berlin, Germany
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Khajavi N, Akbari M, Abolhassani F, Dehpour AR, Koruji M, Habibi Roudkenar M. Role of Somatic Testicular Cells during Mouse Spermatogenesis in Three-Dimensional Collagen Gel Culture System. Cell J 2014; 16:79-90. [PMID: 24518977 PMCID: PMC3933442] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Accepted: 04/11/2013] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Spermatogonial stem cells (SSCs) are the only cell type that can restore fertility to an infertile recipient following transplantation. Much effort has been made to develop a protocol for differentiating isolated SSCs in vitro. Recently, three-dimensional (3D) culture system has been introduced as an appropriate microenvironment for clonal expansion and differentiation of SSCs. This system provides structural support and multiple options for several manipulation such as addition of different cells. Somatic cells have a critical role in stimulating spermatogenesis. They provide complex cell to cell interaction, transport proteins and produce enzymes and regulatory factors. This study aimed to optimize the culture condition by adding somatic testicular cells to the collagen gel culture system in order to induce spermatogenesis progression. MATERIALS AND METHODS In this experimental study, the disassociation of SSCs was performed by using a two-step enzymatic digestion of type I collagenase, hyaluronidase and DNase. Somatic testicular cells including Sertoli cells and peritubular cells were obtained after the second digestion. SSCs were isolated by Magnetic Activated Cell Sorting (MACS) using GDNF family receptor alpha-1 (Gfrα-1) antibody. Two experimental designs were investigated. 1. Gfrα-1 positive SSCs were cultured in a collagen solution. 2. Somatic testicular cells were added to the Gfrα-1 positive SSCs in a collagen solution. Spermatogenesis progression was determined after three weeks by staining of synaptonemal complex protein 3 (SCP3)-positive cells. Semi-quantitative Reverse Transcription PCR was undertaken for SCP3 as a meiotic marker and, Crem and Thyroid transcription factor-1 (TTF1) as post meiotic markers. For statistical analysis student t test was performed. RESULTS Testicular supporter cells increased the expression of meiotic and post meiotic markers and had a positive effect on extensive colony formation. CONCLUSION Collagen gel culture system supported by somatic testicular cells provides a microenvironment that mimics seminiferous epithelium and induces spermatogenesis in vitro.
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Affiliation(s)
- Noushafarin Khajavi
- Department of Anatomical Sciences, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Akbari
- Department of Anatomical Sciences, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran,
*Corresponding Address:
P.O.Box: 1417614411Department of Anatomical SciencesSchool of MedicineTehran University of Medical SciencesTehranIran
| | - Farid Abolhassani
- Department of Anatomical Sciences, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Reza Dehpour
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Morteza Koruji
- Department of Anatomical Sciences, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
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Mergler S, Derckx R, Reinach PS, Garreis F, Böhm A, Schmelzer L, Skosyrski S, Ramesh N, Abdelmessih S, Polat OK, Khajavi N, Riechardt AI. Calcium regulation by temperature-sensitive transient receptor potential channels in human uveal melanoma cells. Cell Signal 2013; 26:56-69. [PMID: 24084605 DOI: 10.1016/j.cellsig.2013.09.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 09/25/2013] [Accepted: 09/25/2013] [Indexed: 11/16/2022]
Abstract
Uveal melanoma (UM) is both the most common and fatal intraocular cancer among adults worldwide. As with all types of neoplasia, changes in Ca(2+) channel regulation can contribute to the onset and progression of this pathological condition. Transient receptor potential channels (TRPs) and cannabinoid receptor type 1 (CB1) are two different types of Ca(2+) permeation pathways that can be dysregulated during neoplasia. We determined in malignant human UM and healthy uvea and four different UM cell lines whether there is gene and functional expression of TRP subtypes and CB1 since they could serve as drug targets to either prevent or inhibit initiation and progression of UM. RT-PCR, Ca(2+) transients, immunohistochemistry and planar patch-clamp analysis probed for their gene expression and functional activity, respectively. In UM cells, TRPV1 and TRPM8 gene expression was identified. Capsaicin (CAP), menthol or icilin induced Ca(2+) transients as well as changes in ion current behavior characteristic of TRPV1 and TRPM8 expression. Such effects were blocked with either La(3+), capsazepine (CPZ) or BCTC. TRPA1 and CB1 are highly expressed in human uvea, but TRPA1 is not expressed in all UM cell lines. In UM cells, the CB1 agonist, WIN 55,212-2, induced Ca(2+) transients, which were suppressed by La(3+) and CPZ whereas CAP-induced Ca(2+) transients could also be suppressed by CB1 activation. Identification of functional TRPV1, TRPM8, TRPA1 and CB1 expression in these tissues may provide novel drug targets for treatment of this aggressive neoplastic disease.
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Affiliation(s)
- Stefan Mergler
- Charité - Universitätsmedizin Berlin, Campus Virchow-Clinic, Department of Ophthalmology, Augustenburger Platz 1, 13353 Berlin, Germany.
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Skrzypski M, Kakkassery M, Mergler S, Grötzinger C, Khajavi N, Sassek M, Szczepankiewicz D, Wiedenmann B, Nowak KW, Strowski MZ. Activation of TRPV4 channel in pancreatic INS-1E beta cells enhances glucose-stimulated insulin secretion via calcium-dependent mechanisms. FEBS Lett 2013; 587:3281-7. [PMID: 23999312 DOI: 10.1016/j.febslet.2013.08.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Revised: 07/16/2013] [Accepted: 08/20/2013] [Indexed: 01/13/2023]
Abstract
Transient receptor potential channel vanilloid type 4 (TRPV4) is a Ca(2+)- and Mg(2+)-permeable cation channel that influences oxidative metabolism and insulin sensitivity. The role of TRPV4 in pancreatic beta cells is largely unknown. Here, we characterize the role of TRPV4 in controlling intracellular Ca(2+) and insulin secretion in INS-1E beta cells. Osmotic, thermal or pharmacological activation of TRPV4 caused a rapid rise of intracellular Ca(2+) and enhanced glucose-stimulated insulin secretion. In the presence of the TRPV channel blocker ruthenium red (RuR) or after suppression of TRPV4 protein production, TRPV4 activators failed to increase [Ca(2+)]i and insulin secretion in INS-1E cells.
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Affiliation(s)
- M Skrzypski
- Department of Hepatology and Gastroenterology, The Interdisciplinary Centre of Metabolism: Endocrinology, Diabetes and Metabolism, Charité-University Medicine Berlin, 13353 Berlin, Germany; Department of Animal Physiology and Biochemistry, Poznań University of Life Sciences, 60-637 Poznań, Poland
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