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Mewes M, Lenders M, Stappers F, Scharnetzki D, Nedele J, Fels J, Wedlich-Söldner R, Brand SM, Schmitz B, Brand E. Soluble adenylyl cyclase (sAC) regulates calcium signaling in the vascular endothelium. FASEB J 2019; 33:13762-13774. [PMID: 31585052 DOI: 10.1096/fj.201900724r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The vascular endothelium acts as a selective barrier between the bloodstream and extravascular tissues. Intracellular [Ca2+]i signaling is essential for vasoactive agonist-induced stimulation of endothelial cells (ECs), typically including Ca2+ release from the endoplasmic reticulum (ER). Although it is known that interactions of Ca2+ and cAMP as ubiquitous messengers are involved in this process, the individual contribution of cAMP-generating adenylyl cyclases (ACs), including the only soluble AC (sAC; ADCY10), remains less clear. Using life-cell microscopy and plate reader-based [Ca2+]i measurements, we found that human immortalized ECs, primary aortic and cardiac microvascular ECs, and primary vascular smooth muscle cells treated with sAC-specific inhibitor KH7 or anti-sAC-small interfering RNA did not show endogenous or exogenous ATP-induced [Ca2+]i elevation. Of note, a transmembrane AC (tmAC) inhibitor did not prevent ATP-induced [Ca2+]i elevation in ECs. Moreover, l-phenylephrine-dependent constriction of ex vivo mouse aortic ring segments was also reduced by KH7. Analysis of the inositol-1,4,5-trisphosphate (IP3) pathway revealed reduced IP3 receptor phosphorylation after KH7 application, which also prevented [Ca2+]i elevation induced by IP3 receptor agonist adenophostin A. Our results suggest that sAC rather than tmAC controls the agonist-induced ER-dependent Ca2+ response in ECs and may represent a treatment target in arterial hypertension and heart failure.-Mewes, M., Lenders, M., Stappers, F., Scharnetzki, D., Nedele, J., Fels, J., Wedlich-Söldner, R., Brand, S.-M., Schmitz, B., Brand, E. Soluble adenylyl cyclase (sAC) regulates calcium signaling in the vascular endothelium.
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Affiliation(s)
- Mirja Mewes
- Internal Medicine D, Department of Nephrology, Hypertension, and Rheumatology, University Hospital Muenster, Muenster, Germany
| | - Malte Lenders
- Internal Medicine D, Department of Nephrology, Hypertension, and Rheumatology, University Hospital Muenster, Muenster, Germany
| | - Franciska Stappers
- Internal Medicine D, Department of Nephrology, Hypertension, and Rheumatology, University Hospital Muenster, Muenster, Germany
| | - David Scharnetzki
- Internal Medicine D, Department of Nephrology, Hypertension, and Rheumatology, University Hospital Muenster, Muenster, Germany
| | - Johanna Nedele
- Internal Medicine D, Department of Nephrology, Hypertension, and Rheumatology, University Hospital Muenster, Muenster, Germany
| | - Johannes Fels
- Institute for Cell Dynamics and Imaging, Medical Faculty, University of Muenster, Muenster, Germany.,Department of Physiology, Pathophysiology, and Toxicology and Center for Biomedical Education and Research (ZBAF), University of Witten/Herdecke, Witten, Germany
| | - Roland Wedlich-Söldner
- Institute for Cell Dynamics and Imaging, Medical Faculty, University of Muenster, Muenster, Germany
| | - Stefan-Martin Brand
- Institute of Sports Medicine, Molecular Genetics of Cardiovascular Disease, University Hospital Muenster, Muenster, Germany
| | - Boris Schmitz
- Institute of Sports Medicine, Molecular Genetics of Cardiovascular Disease, University Hospital Muenster, Muenster, Germany
| | - Eva Brand
- Internal Medicine D, Department of Nephrology, Hypertension, and Rheumatology, University Hospital Muenster, Muenster, Germany
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The effects of recurrent hypoglycaemia and opioid antagonists on the adrenal catecholamine synthetic capacity in a rat model of HAAF. Auton Neurosci 2018; 210:76-80. [DOI: 10.1016/j.autneu.2017.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 12/15/2017] [Accepted: 12/15/2017] [Indexed: 01/11/2023]
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Kim JL, La Gamma EF, Estabrook T, Kudrick N, Nankova BB. Whole genome expression profiling associates activation of unfolded protein response with impaired production and release of epinephrine after recurrent hypoglycemia. PLoS One 2017; 12:e0172789. [PMID: 28234964 PMCID: PMC5325535 DOI: 10.1371/journal.pone.0172789] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 02/09/2017] [Indexed: 12/25/2022] Open
Abstract
Recurrent hypoglycemia can occur as a major complication of insulin replacement therapy, limiting the long-term health benefits of intense glycemic control in type 1 and advanced type 2 diabetic patients. It impairs the normal counter-regulatory hormonal and behavioral responses to glucose deprivation, a phenomenon known as hypoglycemia associated autonomic failure (HAAF). The molecular mechanisms leading to defective counter-regulation are not completely understood. We hypothesized that both neuronal (excessive cholinergic signaling between the splanchnic nerve fibers and the adrenal medulla) and humoral factors contribute to the impaired epinephrine production and release in HAAF. To gain further insight into the molecular mechanism(s) mediating the blunted epinephrine responses following recurrent hypoglycemia, we utilized a global gene expression profiling approach. We characterized the transcriptomes during recurrent (defective counter-regulation model) and acute hypoglycemia (normal counter-regulation group) in the adrenal medulla of normal Sprague-Dawley rats. Based on comparison analysis of differentially expressed genes, a set of unique genes that are activated only at specific time points after recurrent hypoglycemia were revealed. A complementary bioinformatics analysis of the functional category, pathway, and integrated network indicated activation of the unfolded protein response. Furthermore, at least three additional pathways/interaction networks altered in the adrenal medulla following recurrent hypoglycemia were identified, which may contribute to the impaired epinephrine secretion in HAAF: greatly increased neuropeptide signaling (proenkephalin, neuropeptide Y, galanin); altered ion homeostasis (Na+, K+, Ca2+) and downregulation of genes involved in Ca2+-dependent exocytosis of secretory vesicles. Given the pleiotropic effects of the unfolded protein response in different organs, involved in maintaining glucose homeostasis, these findings uncover broader general mechanisms that arise following recurrent hypoglycemia which may afford clinicians an opportunity to modulate the magnitude of HAAF syndrome.
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Affiliation(s)
- Juhye Lena Kim
- The Regional Neonatal Center, Maria Fareri Children’s Hospital at Westchester Medical Center, Valhalla, New York, United States of America
| | - Edmund F. La Gamma
- The Regional Neonatal Center, Maria Fareri Children’s Hospital at Westchester Medical Center, Valhalla, New York, United States of America
- Departments of Pediatrics, Biochemistry and Molecular Biology, Division of Newborn Medicine, New York Medical College, Valhalla, New York, United States of America
| | - Todd Estabrook
- New York Medical College School of Medicine, Valhalla, New York, United States of America
| | - Necla Kudrick
- The Regional Neonatal Center, Maria Fareri Children’s Hospital at Westchester Medical Center, Valhalla, New York, United States of America
| | - Bistra B. Nankova
- Departments of Pediatrics, Biochemistry and Molecular Biology, Division of Newborn Medicine, New York Medical College, Valhalla, New York, United States of America
- * E-mail:
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Zhao J, Zheng Y, Xue F, Chang Y, Yang H, Zhang J. Molecular basis of reactive oxygen species-induced inactivation of α4β2 nicotinic acetylcholine receptors. Free Radic Biol Med 2016; 97:520-530. [PMID: 27445102 DOI: 10.1016/j.freeradbiomed.2016.07.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 07/03/2016] [Accepted: 07/16/2016] [Indexed: 01/11/2023]
Abstract
The α4β2 neuronal nicotinic acetylcholine receptors (nAChRs) are the most widespread heteromeric nAChR subtype in the brain, mediating fast synaptic transmission. Previous studies showed that α4β2 nAChRs could be inactivated by reactive oxygen species (ROS), but the underlying mechanism is still obscure. We found that H2O2 induced the rundown of ACh-evoked currents in human α4β2 nAChRs and the replacement of the conserved cysteine in the M1-M2 linker of either α4 Cys245 or β2 Cys237 with an alanine residue could prevent the current rundown. Structurally, α4 Cys245 and β2 Cys237 are hypothesized to be in close proximity when the receptor is activated. Western blotting results showed that α4 and β2 subunits were cross-linked when the agonist-bound receptor encountered H2O2, which could be prevented by the substitution of the conserved cysteine in the M1-M2 linker to an alanine. Thus, when agonist bound to the receptor, α4 Cys245 and β2 Cys237 came close to each other and ROS oxidized these conserved cysteines, leading subunits to be cross-linked and trapping α4β2 nAChRs into the inactivation state. In addition, we mimicked an experimental Parkinson's disease (PD) model in PC12 cells and found that ROS, generated by 6-hydroxydopamine (6-OHDA), could cause the current rundown in α4β2 nAChRs, which may play a role in PD.
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Affiliation(s)
- Junjun Zhao
- Department of Neurobiology, Beijing Institute of Brain Disorders, Capital Medical University, Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Beijing Center of Neural Regeneration and Repair, Beijing Key Laboratory of Brain Major Disorders-State Key Lab Incubation Base, Beijing Neuroscience Disciplines, Beijing 100069, China
| | - Yan Zheng
- Department of Neurobiology, Beijing Institute of Brain Disorders, Capital Medical University, Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Beijing Center of Neural Regeneration and Repair, Beijing Key Laboratory of Brain Major Disorders-State Key Lab Incubation Base, Beijing Neuroscience Disciplines, Beijing 100069, China
| | - Fenqin Xue
- Medical Experiment and Test Center, Capital Medical University, Beijing 100069, China
| | - Yongchang Chang
- Division of Neurobiology, Barrow Neurological Institute and St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, USA
| | - Hui Yang
- Department of Neurobiology, Beijing Institute of Brain Disorders, Capital Medical University, Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Beijing Center of Neural Regeneration and Repair, Beijing Key Laboratory of Brain Major Disorders-State Key Lab Incubation Base, Beijing Neuroscience Disciplines, Beijing 100069, China.
| | - Jianliang Zhang
- Department of Neurobiology, Beijing Institute of Brain Disorders, Capital Medical University, Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Beijing Center of Neural Regeneration and Repair, Beijing Key Laboratory of Brain Major Disorders-State Key Lab Incubation Base, Beijing Neuroscience Disciplines, Beijing 100069, China.
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Rawlins F, Johnston C, Wyssusek K. Cardiac and Abdominal Pheochromocytomas: Anesthetic Management for a Combined Cardiac and Hepatobiliary Procedure. J Cardiothorac Vasc Anesth 2015; 29:995-8. [PMID: 25604602 DOI: 10.1053/j.jvca.2013.12.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Indexed: 11/11/2022]
Affiliation(s)
| | - Craig Johnston
- Department of Anesthesiology, Princess Alexandria Hospital
| | - Kerstin Wyssusek
- Department of Anesthesiology, Princess Alexandria Hospital; School of Medicine, University of Queensland, Brisbane, Australia
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Corticotrophin-Releasing Factor (CRF) and the urocortins are potent regulators of the inflammatory phenotype of human and mouse white adipocytes and the differentiation of mouse 3T3L1 pre-adipocytes. PLoS One 2014; 9:e97060. [PMID: 24835211 PMCID: PMC4024041 DOI: 10.1371/journal.pone.0097060] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 04/15/2014] [Indexed: 11/19/2022] Open
Abstract
Chronic activation of innate immunity takes place in obesity and initiated by the hypertrophic adipocytes which obtain a pro-inflammatory phenotype. The corticotrophin-releasing factor (CRF) family of neuropeptides and their receptors (CRF1 and CRF2) affect stress response and innate immunity. Adipose tissue expresses a complete CRF system. The aim of this study was to examine the role of CRF neuropeptides in the immune phenotype of adipocytes assessed by their expression of the toll-like receptor-4 (TLR4), the production of inflammatory cytokines IL-6, TNF-α and IL-1β, chemokines IL-8, monocyte attractant protein-1 (MCP-1) and of the adipokines adiponectin, resistin and leptin. Our data are as follows: (a) CRF, UCN2 and UCN3 are expressed in human white adipocytes as well as CRFR1a, CRFR2a and CRFR2b but not CRFR2c. 3T3L1 pre-adipocytes and differentiated adipocytes expressed both CRF1 and CRF2 receptors and UCN3, while UCN2 was detected only in differentiated adipocytes. CRF2 was up-regulated in mouse mature adipocytes. (b) CRF1 agonists suppressed media- and LPS-induced pre-adipocyte differentiation while CRF2 receptor agonists had no effect. (c) In mouse pre-adipocytes, CRF2 agonists suppressed TLR4 expression and the production of IL-6, CXCL1 and adiponectin while CRF1 agonists had no effect. (d) In mature mouse adipocytes LPS induced IL-6 and CXCL1 production and suppressed leptin. (e) In human visceral adipocytes LPS induced IL-6, TNF-α, IL-8, MCP-1 and leptin production and suppressed adiponectin and resistin. (f) In mouse mature adipocytes CRF1 and CRF2 agonists suppressed basal and LPS-induced production of inflammatory cytokines, TLR4 expression and adiponectin production, while in human visceral adipocytes CRF and UCN1 suppressed basal and LPS-induced IL-6, TNF-α, IL-8 and MCP-1 production. In conclusion, the effects of the activation of CRF1 and CRF2 may be significant in ameliorating the pro-inflammatory activity of adipocytes in obesity.
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Milman S, Leu J, Shamoon H, Vele S, Gabriely I. Opioid receptor blockade prevents exercise-associated autonomic failure in humans. Diabetes 2012; 61:1609-15. [PMID: 22522612 PMCID: PMC3357274 DOI: 10.2337/db11-1622] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Hypoglycemia and exercise both induce the release of β-endorphin, which plays an important role in the modulation of the autonomic response during subsequent events. Because opioid receptor (OR) blockade during antecedent hypoglycemia has been shown to prevent hypoglycemia-associated autonomic failure, we hypothesized that OR blockade during exercise would prevent exercise-associated autonomic failure (EAAF). We studied 8 healthy subjects on 2 consecutive days, each of whom participated in three different studies in random order. The protocol on day 1 involved one of the following: 1) two 90-min hyperinsulinemic-euglycemic clamps plus naloxone infusion (control); 2) two 90-min hyperinsulinemic-euglycemic clamps with exercise at 60% Vo(2max), plus naloxone infusion (N+); or 3) same protocol as in the N+ group, but with saline infusion only (N-). On day 2, all were studied with stepped hyperinsulinemic-hypoglycemic clamps, using hormone concentrations and glucose turnover as indicators of hypoglycemia counterregulation. Compared with control, N- studies resulted in significantly blunted epinephrine and norepinephrine responses to subsequent hypoglycemia. Conversely, the N+ group exhibited unimpaired hypoglycemia counterregulation, characterized by appropriate increases in epinephrine, norepinephrine, and endogenous glucose production. Thus, OR blockade with naloxone during antecedent exercise prevents the development of acute EAAF by improving the catecholamine responses and by restoring endogenous glucose production.
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Affiliation(s)
- Sofiya Milman
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Albert Einstein College of Medicine, Bronx, New York
| | - James Leu
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Albert Einstein College of Medicine, Bronx, New York
| | - Harry Shamoon
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Albert Einstein College of Medicine, Bronx, New York
- Institute for Clinical and Translational Research, Albert Einstein College of Medicine, Bronx, New York
| | - Septimiu Vele
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Albert Einstein College of Medicine, Bronx, New York
| | - Ilan Gabriely
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Albert Einstein College of Medicine, Bronx, New York
- Corresponding author: Ilan Gabriely,
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Vele S, Milman S, Shamoon H, Gabriely I. Opioid receptor blockade improves hypoglycemia-associated autonomic failure in type 1 diabetes mellitus. J Clin Endocrinol Metab 2011; 96:3424-31. [PMID: 21917871 PMCID: PMC3205891 DOI: 10.1210/jc.2011-1723] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
CONTEXT Recurrent hypoglycemia induces hypoglycemia-associated autonomic failure (HAAF), characterized by deterioration in counterregulatory responses. Endogenous opioids may mediate the development of HAAF, and blockade of opioid receptors with naloxone prevented HAAF in nondiabetic subjects. OBJECTIVE We hypothesized that opioid receptor blockade with naloxone during antecedent hypoglycemia in patients with type 1 diabetes mellitus (T1DM) would prevent the development of HAAF. DESIGN, SETTING, PARTICIPANTS, AND INTERVENTIONS Eight subjects with T1DM (three women, aged 34 ± 7.4 yr, hemoglobin A1c 7.3 ± 1.1%) were studied on 2 consecutive days on three separate occasions. Day 1 consisted of: 1) two 90-min hypoglycemic clamps (60 mg/dl, N-); 2) two 90-min hypoglycemic clamps (60 mg/dl) with concomitant naloxone infusion (N+); or 3) two 90-min euglycemic clamps (90 mg/dl) with concomitant naloxone infusion (control). Day 2 consisted of hyperinsulinemic stepped hypoglycemic clamps (90, 80, 70, and 60 mg/dl plasma glucose steps). MAIN OUTCOME MEASURES Day 2 hypoglycemia counterregulatory hormonal response and glucose turnover [(3-(3)H)-glucose] as indicators of recovery from hypoglycemia. RESULTS Antecedent hypoglycemia in N- group resulted in a markedly decreased epinephrine response and a lower rate of endogenous glucose production (EGP) during subsequent hypoglycemia compared with control (75 ± 17 vs. 187 ± 21 pg/ml, P < 0.05 and 0.8 ± 0.1 vs. 1.4 ± 0.2 mg/kg · min, P < 0.05, respectively). In contrast, in the N+ studies, plasma epinephrine was 164 ± 18 pg/ml and EGP was 1.3 ± 0.2 mg/kg · min during subsequent hypoglycemia, both levels similar to those seen in control studies (P = NS vs. control). Plasma glucagon did not increase with hypoglycemia. CONCLUSIONS Blockade of endogenous opioids with naloxone during antecedent hypoglycemia improves HAAF in patients with T1DM by ameliorating the epinephrine response and restoring EGP.
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Affiliation(s)
- Septimiu Vele
- Department of Medicine, Albert Einstein College of Medicine, Belfer 702, 1300 Morris Park Avenue, Bronx, New York 10461, USA
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Evans TG, Somero GN. A microarray-based transcriptomic time-course of hyper- and hypo-osmotic stress signaling events in the euryhaline fish Gillichthys mirabilis: osmosensors to effectors. ACTA ACUST UNITED AC 2009; 211:3636-49. [PMID: 18978229 DOI: 10.1242/jeb.022160] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cells respond to changes in osmolality with compensatory adaptations that re-establish ion homeostasis and repair disturbed aspects of cell structure and function. These physiological processes are highly complex, and require the coordinated activities of osmosensing, signal transducing and effector molecules. Although the critical role of effector proteins such as Na+, K+-ATPases and Na+/K+/Cl(-) co-transporters during osmotic stress are well established, comparatively little information is available regarding the identity or expression of the osmosensing and signal transduction genes that may govern their activities. To better resolve this issue, a cDNA microarray consisting of 9207 cDNA clones was used to monitor gene expression changes in the gill of the euryhaline fish Gillichthys mirabilis exposed to hyper- and hypo-osmotic stress. We successfully annotated 168 transcripts differentially expressed during the first 12 h of osmotic stress exposure. Functional classifications of genes encoding these transcripts reveal that a variety of biological processes are affected. However, genes participating in cell signaling events were the dominant class of genes differentially expressed during both hyper- and hypo-osmotic stress. Many of these genes have had no previously reported role in osmotic stress adaptation. Subsequent analyses used the novel expression patterns generated in this study to place genes within the context of osmotic stress sensing, signaling and effector events. Our data indicate multiple major signaling pathways work in concert to modify diverse effectors, and that these molecules operate within a framework of regulatory proteins.
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Affiliation(s)
- Tyler G Evans
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA.
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Nikolaeva AA, Koroleva SV, Ashmarin IP. Construction of a generalized scheme of inductive connections between norepinephrine and regulatory peptides. NEUROCHEM J+ 2008. [DOI: 10.1134/s1819712408030057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Vassou D, Bakogeorgou E, Kampa M, Dimitriou H, Hatzoglou A, Castanas E. Opioids modulate constitutive B-lymphocyte secretion. Int Immunopharmacol 2008; 8:634-44. [DOI: 10.1016/j.intimp.2008.01.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Revised: 12/17/2007] [Accepted: 01/03/2008] [Indexed: 11/26/2022]
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Dermitzaki E, Tsatsanis C, Minas V, Chatzaki E, Charalampopoulos I, Venihaki M, Androulidaki A, Lambropoulou M, Spiess J, Michalodimitrakis E, Gravanis A, Margioris AN. Corticotropin-releasing factor (CRF) and the urocortins differentially regulate catecholamine secretion in human and rat adrenals, in a CRF receptor type-specific manner. Endocrinology 2007; 148:1524-38. [PMID: 17194738 DOI: 10.1210/en.2006-0967] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Corticotropin-releasing factor (CRF) affects catecholamine production both centrally and peripherally. The aim of the present work was to examine the presence of CRF, its related peptides, and their receptors in the medulla of human and rat adrenals and their direct effect on catecholamine synthesis and secretion. CRF, urocortin I (UCN1), urocortin II (UCN2), and CRF receptor type 1 (CRF1) and 2 (CRF2) were present in human and rat adrenal medulla as well as the PC12 pheochromocytoma cells by immunocytochemistry, immunofluorescence, and RT-PCR. Exposure of dispersed human and rat adrenal chromaffin cells to CRF1 receptor agonists induced catecholamine secretion in a dose-dependent manner, an effect peaking at 30 min, whereas CRF2 receptor agonists suppressed catecholamine secretion. The respective effects were blocked by CRF1 and CRF2 antagonists. CRF peptides affected catecholamine secretion via changes of subplasmaliminal actin filament polymerization. CRF peptides also affected catecholamine synthesis. In rat chromaffin and PC12 cells, CRF1 and CRF2 agonists induced catecholamine synthesis via tyrosine hydroxylase. However, in human chromaffin cells, activation of CRF1 receptors induced tyrosine hydroxylase, whereas activation of CRF2 suppressed it. In conclusion, it appears that a complex intraadrenal CRF-UCN/CRF-receptor system exists in both human and rat adrenals controlling catecholamine secretion and synthesis.
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Affiliation(s)
- E Dermitzaki
- Department of Clinical Chemistry-Biochemistry, School of Medicine, University of Crete, Heraklion GR-710 03, Crete, Greece
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Charalampopoulos I, Dermitzaki E, Vardouli L, Tsatsanis C, Stournaras C, Margioris AN, Gravanis A. Dehydroepiandrosterone sulfate and allopregnanolone directly stimulate catecholamine production via induction of tyrosine hydroxylase and secretion by affecting actin polymerization. Endocrinology 2005; 146:3309-18. [PMID: 15860555 DOI: 10.1210/en.2005-0263] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Adrenal cortical cells of zona reticularis produce the neuroactive steroids dehydroepiandrosterone (DHEA), its sulfate ester dehydroepiandrosterone sulfate (DHEAS), and allopregnanolone (ALLO). An interaction between zona reticularis and adrenal medulla has been postulated based on their close proximity and their interwoven borders. The aim of this paper was to examine in vitro the possible paracrine effects of these steroids on catecholamine production from adrenomedullary chromaffin cells, using an established in vitro model of chromaffin cells, the PC12 rat pheochromocytoma cell line. We have found the following: 1) DHEA, DHEAS, and ALLO increased acutely (peak effect between 10-30 min) and dose-dependently (EC50 in the nanomolar range) catecholamine levels (norepinephrine and dopamine). 2) It appears that the acute effect of these steroids involved actin depolymerization/actin filament disassembly, a fast-response cellular system regulating trafficking of catecholamine vesicles. Specifically, 10(-6) m phallacidin, an actin filament stabilizer, completely prevented steroid-induced catecholamine secretion. 3) DHEAS and ALLO, but not DHEA, also affected catecholamine synthesis. Indeed, DHEAS and ALLO increased catecholamine levels at 24 h, an effect blocked by L-2-methyl-3-(-4-hydroxyphenyl)alanine and 3-(hydrazinomethyl)phenol hydrochloride, inhibitors of tyrosine hydroxylase and L-aromatic amino acid decarboxylase, respectively, suggesting that this effect involved catecholamine synthesis. The latter hypothesis was confirmed by finding that DHEAS and ALLO increased both the mRNA and protein levels of tyrosine hydroxylase. In conclusion, our findings suggest that neuroactive steroids exert a direct tonic effect on adrenal catecholamine synthesis and secretion. These data associate the adrenomedullary malfunction observed in old age and neuroactive steroids.
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Affiliation(s)
- I Charalampopoulos
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion GR-711 10, Crete, Greece
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Kim OM, Lim GH, Lim DY. Influence of naloxone on catecholamine release evoked by nicotinic receptor stimulation in the isolated rat adrenal gland. Arch Pharm Res 2005; 28:699-708. [PMID: 16042080 DOI: 10.1007/bf02969361] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The present study was designed to investigate the effect of naloxone, a well known opioid antagonist, on the secretion of catecholamines (CA) evoked by cholinergic stimulation and membrane-depolarization in the isolated perfused rat adrenal glands, and to establish its mechanism of action. Naloxone (10(-6) approximately 10(-5) M), perfused into an adrenal vein for 60 min, produced dose- and time-dependent inhibition of CA secretory responses evoked by ACh (5.32 x 10(-3) M), high K+ (5.6 x 10(-2) M), DMPP (10(-4) M) and McN-A-343 (10(-4) M). Naloxone itself also failed to affect the basal CA output. In adrenal glands loaded with naloxone (3 x 10(-6) M), the CA secretory responses evoked by Bay-K-8644, an activator of L-type Ca2+ channels, and cyclopiazonic acid, an inhibitor of cytoplasmic Ca(2+)-ATPase, were also inhibited. In the presence of met-enkephalin (5 x 10(-6) M), a well known opioid agonist, the CA secretory responses evoked by ACh, high K+, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were also significantly inhibited. Taken together, these results suggest that naloxone greatly inhibits the CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as that by membrane depolarization. It seems that these inhibitory effects of naloxone does not involve opioid receptors, but might be mediated by blocking both the calcium influx into the rat adrenal medullary chromaffin cells and the uptake of Ca2+ into the cytoplasmic calcium store, which are at least partly relevant to the direct interaction with the nicotinic receptor itself.
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MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/antagonists & inhibitors
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Acetylcholine/antagonists & inhibitors
- Acetylcholine/pharmacology
- Adrenal Glands/drug effects
- Adrenal Glands/metabolism
- Animals
- Catecholamines/antagonists & inhibitors
- Catecholamines/metabolism
- Dimethylphenylpiperazinium Iodide/antagonists & inhibitors
- Dimethylphenylpiperazinium Iodide/pharmacology
- Dose-Response Relationship, Drug
- Enkephalin, Methionine/administration & dosage
- Enkephalin, Methionine/pharmacology
- Indoles/antagonists & inhibitors
- Indoles/pharmacology
- Male
- Naloxone/administration & dosage
- Naloxone/pharmacology
- Perfusion
- Potassium/antagonists & inhibitors
- Potassium/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptors, Nicotinic/drug effects
- Receptors, Nicotinic/metabolism
- Stimulation, Chemical
- Time Factors
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Affiliation(s)
- Ok-Min Kim
- Department of Pharmacology, College of Medicine, Chosun University, Gwangju 501-759, Korea
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15
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Dermitzaki E, Tsatsanis C, Charalampopoulos I, Androulidaki A, Alexaki VI, Castanas E, Gravanis A, Margioris AN. Corticotropin-releasing hormone activates protein kinase C in an isoenzyme-specific manner. Biochem Biophys Res Commun 2005; 327:828-36. [PMID: 15649420 DOI: 10.1016/j.bbrc.2004.12.078] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2004] [Indexed: 11/26/2022]
Abstract
Protein kinase C (PKC) has recently emerged as mediator of corticotropin-releasing hormone (CRH) effects. Aim of the present study was to study the effects of CRH on each PKC isoenzyme. As a model we have used the PC12 rat pheochromocytoma cell line, expressing the CRH type 1 receptor (CRHR1). Our data were as follows: (a) CRH-induced rapid phosphorylation of conventional PKCalpha and PKCbeta, accompanied by parallel increase of their concentration within nucleus. (b) CRH suppressed the phosphorylation of novel PKCdelta and PKCtheta;, which remained in the cytosol. (c) CRH-induced transient phosphorylation of atypical PKClambda and had no effect on PKCmu. (d) The effect of CRH on each PKC isoenzyme was blocked by a CRHR1 antagonist. (e) Blockade of conventional PKC phosphorylation inhibited CRH-induced calcium ion mobilization from intracellular stores as well as the CRH-induced apoptosis and Fas ligand production. In conclusion, our findings suggest that CRH via its CRHR1 receptor differentially regulates PKC-isoenzyme phosphorylation, an apparently physiologically relevant effect since blockade of conventional PKC phosphorylation abolished the biological effect of CRH.
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Affiliation(s)
- Erini Dermitzaki
- Department of Clinical Chemistry-Biochemistry, School of Medicine, University of Crete, Heraklion, Crete GR-710 03, Greece
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16
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Chudapongse N, Kim SY, Sasaki K, Kramer RE, Ho IK. Nonopioid receptor-mediated effects of U-50,488H on [Ca2+]i and extracellular dopamine in PC12 cells. J Neurosci Res 2003; 74:598-604. [PMID: 14598304 DOI: 10.1002/jnr.10801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The present studies were carried out to determine the effects of a kappa-opioid receptor agonist on cytosolic Ca(2+) concentration, [Ca(2+)](i), and extracellular dopamine in undifferentiated PC12 cells. The kappa-opioid receptor agonist U-50,488H caused concentration-dependent increases in [Ca(2+)](i) and extracellular dopamine. Neither effect was blocked by the selective kappa-opioid receptor antagonist nor-binaltorphimine. Increases in extracellular dopamine content and [Ca(2+)](i) caused by U-50,488H were correlated positively in the presence of extracellular Ca(2+); however, reduction of extracellular Ca(2+) abolished the increase in [Ca(2+)](i), but not that in dopamine. The latter observation suggests that stimulation of exocytotic release is not the primary mechanism involved in the increase in extracellular dopamine caused by U-50,488H. Effects on dopamine synthesis or catabolism also seem unlikely because the enhancement of extracellular dopamine occurred rapidly, and the amount of a major metabolite of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), was not affected. In any event, neither the increase in [Ca(2+)](i) nor the increase in extracellular dopamine caused by U-50,488H is mediated by the kappa-opioid receptor.
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Affiliation(s)
- Nuannoi Chudapongse
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216-4505, USA
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17
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Washburn CL, Bean JE, Silverman MA, Pellegrino MJ, Yates PA, Allen RG. Regulation of peptidergic vesicle mobility by secretagogues. Traffic 2002; 3:801-9. [PMID: 12383346 DOI: 10.1034/j.1600-0854.2002.31105.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Neuropeptides are released into the extracellular space from large secretory granules. In order to reach their release sites, these granules are translocated on microtubules and thought to interact with filamentous actin as they approach the cell membrane. We have used a green fluorescent protein-tagged neuropeptide prohormone (prepro-orphanin FQ) to visualize vesicle trafficking dynamics in NS20Y cells and cultures of primary hippocampal neurons. We found that the majority of secretory granules were mobile and accumulated at both the tips of neurites as well as other apparently specialized cellular sites. We also used live-cell imaging to test the notion that peptidergic vesicle mobility was regulated by secretagogues. We show that treatment with forskolin appeared to increase vesicle rates of speed, while depolarization with high K+ had no effect, even though both treatments stimulated neuropeptide secretion. In cultured hippocampal neurons the green fluorescent protein-tagged secretory vesicles were routed to both dendrites and axons, indicating that peptidergic vesicle transport was not polarized. Basal peptidergic vesicle mobility rates in hippocampal neurons were the same as those in NS20Y cells. Taken together, these studies suggest that secretory vesicle mobility is regulated by specific classes of secretagogues and that neuropeptide containing secretory vesicles may be released from dendritic structures.
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Affiliation(s)
- C L Washburn
- Center for Research on Occupational and Environmental Toxicology, The Vollum Institute Portland, OR 97201, USA
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18
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Kampa M, Papakonstanti EA, Hatzoglou A, Stathopoulos EN, Stournaras C, Castanas E. The human prostate cancer cell line LNCaP bears functional membrane testosterone receptors that increase PSA secretion and modify actin cytoskeleton. FASEB J 2002; 16:1429-31. [PMID: 12205037 DOI: 10.1096/fj.02-0131fje] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Recent findings have shown that, in addition to the genomic action of steroids, through intracellular receptors, short-time effects could be mediated through binding to membrane sites. In the present study of prostate cancer LNCaP cells, we report that dihydrotestosterone and the non-internalizable analog testosterone-BSA increase rapidly the release of prostate-specific antigen (PSA) in the culture medium. Membrane testosterone binding sites were identified through ligand binding on membrane preparations, flow cytometry, and confocal laser microscopy of the non-internalizable fluorescent analog testosterone-BSA-FITC, on whole cells. Binding on these sites is time- and concentration-dependent and specific for testosterone, presenting a KD of 10.9 nM and a number of 144 sites/mg protein (approximately 13000 sites/cell). Membrane sites differ immunologically for intracellular androgen receptors. The secretion of PSA after membrane testosterone receptor stimulation was inhibited after pretreatment with the actin cytoskeleton disrupting agent cytochalasin B. In addition, membrane testosterone binding modifies the intracellular dynamic equilibrium of monomeric to filamentous actin and remodels profoundly the actin cytoskeleton organization. These results are discussed in the context of a possible involvement of these sites in cancer chemotherapy.
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Affiliation(s)
- Maeilena Kampa
- Laboratories of, Experimental Endocrinology, University of Crete, School of Medicine, Heraklion, GR-71110, Greece
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