1
|
Lingampelly SS, Naviaux JC, Heuer LS, Monk JM, Li K, Wang L, Haapanen L, Kelland CA, Van de Water J, Naviaux RK. Metabolic network analysis of pre-ASD newborns and 5-year-old children with autism spectrum disorder. Commun Biol 2024; 7:536. [PMID: 38729981 DOI: 10.1038/s42003-024-06102-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 03/22/2024] [Indexed: 05/12/2024] Open
Abstract
Classical metabolomic and new metabolic network methods were used to study the developmental features of autism spectrum disorder (ASD) in newborns (n = 205) and 5-year-old children (n = 53). Eighty percent of the metabolic impact in ASD was caused by 14 shared biochemical pathways that led to decreased anti-inflammatory and antioxidant defenses, and to increased physiologic stress molecules like lactate, glycerol, cholesterol, and ceramides. CIRCOS plots and a new metabolic network parameter,V ° net, revealed differences in both the kind and degree of network connectivity. Of 50 biochemical pathways and 450 polar and lipid metabolites examined, the developmental regulation of the purine network was most changed. Purine network hub analysis revealed a 17-fold reversal in typically developing children. This purine network reversal did not occur in ASD. These results revealed previously unknown metabolic phenotypes, identified new developmental states of the metabolic correlation network, and underscored the role of mitochondrial functional changes, purine metabolism, and purinergic signaling in autism spectrum disorder.
Collapse
Affiliation(s)
- Sai Sachin Lingampelly
- The Mitochondrial and Metabolic Disease Center, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA
- Department of Medicine, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA
| | - Jane C Naviaux
- The Mitochondrial and Metabolic Disease Center, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA
- Department of Neuroscience, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA
| | - Luke S Heuer
- The UC Davis MIND Institute, University of California, Davis, Davis, CA, 95616, USA
| | - Jonathan M Monk
- The Mitochondrial and Metabolic Disease Center, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA
- Department of Medicine, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA
| | - Kefeng Li
- The Mitochondrial and Metabolic Disease Center, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA
- Department of Medicine, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA
- Macao Polytechnic University, Macau, China
| | - Lin Wang
- The Mitochondrial and Metabolic Disease Center, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA
- Department of Medicine, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA
| | - Lori Haapanen
- The UC Davis MIND Institute, University of California, Davis, Davis, CA, 95616, USA
| | - Chelsea A Kelland
- The UC Davis MIND Institute, University of California, Davis, Davis, CA, 95616, USA
| | - Judy Van de Water
- The UC Davis MIND Institute, University of California, Davis, Davis, CA, 95616, USA
- Department of Rheumatology and Allergy, School of Veterinary Medicine, University of California, Davis, Davis, CA, 95616, USA
| | - Robert K Naviaux
- The Mitochondrial and Metabolic Disease Center, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA.
- Department of Medicine, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA.
- Department of Pediatrics, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA.
- Department of Pathology, University of California, San Diego School of Medicine, San Diego, CA, 92103-8467, USA.
| |
Collapse
|
2
|
Hu Q, Li G. Role of purinergic receptors in cardiac sympathetic nerve injury in diabetes mellitus. Neuropharmacology 2023; 226:109406. [PMID: 36586475 DOI: 10.1016/j.neuropharm.2022.109406] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 12/13/2022] [Accepted: 12/23/2022] [Indexed: 12/30/2022]
Abstract
Diabetic cardiac autonomic neuropathy is a common and serious chronic complication of diabetes, which can lead to sympathetic and parasympathetic nerve imbalance and a relative excitation of the sympathetic nerve. Purinergic receptors play a crucial role in this process. Diabetic cardiac sympathetic nerve injury affects the expression of purinergic receptors, and activated purinergic receptors affect the phosphorylation of different signaling pathways and the regulation of inflammatory processes. This paper introduces the abnormal changes of sympathetic nerve in diabetes mellitus and summarizes the recently published studies on the role of several purinergic receptor subtypes in diabetic cardiac sympathetic nerve injury. These studies suggest that purinergic receptors as novel drug targets are of great significance for the treatment of diabetic autonomic neuropathy. This article is part of the Special Issue on "Purinergic Signaling: 50 years".
Collapse
Affiliation(s)
- Qixing Hu
- Department of Physiology, Medical School of Nanchang University, 461 Bayi Road, Nanchang, Jiangxi, 330006, PR China.
| | - Guilin Li
- Department of Physiology, Medical School of Nanchang University, 461 Bayi Road, Nanchang, Jiangxi, 330006, PR China.
| |
Collapse
|
3
|
Schubert C, Schulz K, Träger S, Plath AL, Omriouate A, Rosenkranz SC, Morellini F, Friese MA, Hirnet D. Neuronal Adenosine A1 Receptor is Critical for Olfactory Function but Unable to Attenuate Olfactory Dysfunction in Neuroinflammation. Front Cell Neurosci 2022; 16:912030. [PMID: 35846561 PMCID: PMC9279574 DOI: 10.3389/fncel.2022.912030] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 06/08/2022] [Indexed: 11/13/2022] Open
Abstract
Adenine nucleotides, such as adenosine triphosphate (ATP), adenosine diphosphate (ADP), as well as the nucleoside adenosine are important modulators of neuronal function by engaging P1 and P2 purinergic receptors. In mitral cells, signaling of the G protein-coupled P1 receptor adenosine 1 receptor (A1R) affects the olfactory sensory pathway by regulating high voltage-activated calcium channels and two-pore domain potassium (K2P) channels. The inflammation of the central nervous system (CNS) impairs the olfactory function and gives rise to large amounts of extracellular ATP and adenosine, which act as pro-inflammatory and anti-inflammatory mediators, respectively. However, it is unclear whether neuronal A1R in the olfactory bulb modulates the sensory function and how this is impacted by inflammation. Here, we show that signaling via neuronal A1R is important for the physiological olfactory function, while it cannot counteract inflammation-induced hyperexcitability and olfactory deficit. Using neuron-specific A1R-deficient mice in patch-clamp recordings, we found that adenosine modulates spontaneous dendro-dendritic signaling in mitral and granule cells via A1R. Furthermore, neuronal A1R deficiency resulted in olfactory dysfunction in two separate olfactory tests. In mice with experimental autoimmune encephalomyelitis (EAE), we detected immune cell infiltration and microglia activation in the olfactory bulb as well as hyperexcitability of mitral cells and olfactory dysfunction. However, neuron-specific A1R activity was unable to attenuate glutamate excitotoxicity in the primary olfactory bulb neurons in vitro or EAE-induced olfactory dysfunction and disease severity in vivo. Together, we demonstrate that A1R modulates the dendro-dendritic inhibition (DDI) at the site of mitral and granule cells and impacts the processing of the olfactory sensory information, while A1R activity was unable to counteract inflammation-induced hyperexcitability.
Collapse
Affiliation(s)
- Charlotte Schubert
- Institute of Neuroimmunology and Multiple Sclerosis (INIMS), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kristina Schulz
- Division of Neurophysiology, Institute of Cell and Systems Biology of Animals, University of Hamburg, Hamburg, Germany
| | - Simone Träger
- Institute of Neuroimmunology and Multiple Sclerosis (INIMS), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Anna-Lena Plath
- Research Group Behavioral Biology, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Asina Omriouate
- Research Group Behavioral Biology, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sina C. Rosenkranz
- Institute of Neuroimmunology and Multiple Sclerosis (INIMS), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fabio Morellini
- Research Group Behavioral Biology, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Manuel A. Friese
- Institute of Neuroimmunology and Multiple Sclerosis (INIMS), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- *Correspondence: Manuel A. Friese,
| | - Daniela Hirnet
- Division of Neurophysiology, Institute of Cell and Systems Biology of Animals, University of Hamburg, Hamburg, Germany
- Daniela Hirnet,
| |
Collapse
|
4
|
Zou L, Liu S, Li L, Yang R, Xu X, Li G, Zhang C, Li G, Liang S. Implication of P2Y 12 receptor in uc.48+-mediated abnormal sympathoexcitatory reflex via superior cervical ganglia in myocardial ischemic rats. Eur J Pharmacol 2022; 927:175049. [PMID: 35644421 DOI: 10.1016/j.ejphar.2022.175049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 05/19/2022] [Accepted: 05/19/2022] [Indexed: 12/28/2022]
Abstract
Purinergic 2Y12 (P2Y12) receptor antagonists are used as platelet aggregation inhibitors. Long non-coding RNAs (lncRNAs) play an important role in neuropathological events. Satellite glial cells (SGCs) in the superior cervical ganglia (SCGs) encircle the somata of neurons. This study explored if the upregulated P2Y12 receptor in SCGs was relevant to lncRNA uc.48+ during myocardial ischemia (MI). The results showed that upregulation of P2Y12 receptor was accompanied by increased expression of uc.48+ in the SCGs of MI rats which displayed abnormal changes in cervical sympathetic nerve activity, blood pressure, heart rate, electrocardiograms and cardiac tissue structure. The P2Y12 antagonist clopidogrel improved abnormal alterations in cardiac function and tissue structure in MI rats. Short hairpin RNA (shRNA) against uc.48+ significantly inhibited P2Y12 receptor upregulation and its co-expression with glial fibrillary acidic protein (GFAP) in SCGs, and ameliorated the cardiac dysfunction in MI rats. By contrast, overexpression of uc.48+ increased the expression of P2Y12 in SCGs and enhanced cervical sympathetic nerve activity in control rats. Direct interaction between uc.48+ and the P2Y12 receptor was predicted using the bioinformatic tool CatRAPID and confirmed by RNA immunoprecipitation. Moreover, overexpression of the P2Y12 receptor reversed the protective effect of uc.48+ shRNA on cardiac dysfunction in MI rats. Uc.48 shRNA treatment also inhibited the enhanced rise of intracellular free Ca2+ level ([Ca2+]i) evoked by the P2Y12 agonist 2-methylthio-adenosine-5'-diphosphate (2-MeSADP) in SGCs of SCGs after oxygen-glucose deprivation (OGD) treatment. These data demonstrated that uc.48+ shRNA could counteract the P2Y12 upregulation and improve P2Y12-implicated cardiac dysfunction due to MI.
Collapse
Affiliation(s)
- Lifang Zou
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, 330006, PR China; Department of Hematology, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, PR China
| | - Shuangmei Liu
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, 330006, PR China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi, 330006, PR China
| | - Lin Li
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, 330006, PR China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi, 330006, PR China
| | - Runan Yang
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, 330006, PR China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi, 330006, PR China
| | - Xiumei Xu
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, 330006, PR China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi, 330006, PR China
| | - Guilin Li
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, 330006, PR China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi, 330006, PR China
| | - Chunping Zhang
- Department of Cell Biology, Medical School of Nanchang University, Nanchang, 330006, PR China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi, 330006, PR China
| | - Guodong Li
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, 330006, PR China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi, 330006, PR China
| | - Shangdong Liang
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, 330006, PR China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi, 330006, PR China.
| |
Collapse
|
5
|
Cardoso AM, Silvério MNO, de Oliveira Maciel SFV. Purinergic signaling as a new mechanism underlying physical exercise benefits: a narrative review. Purinergic Signal 2021; 17:649-679. [PMID: 34590239 PMCID: PMC8677870 DOI: 10.1007/s11302-021-09816-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 07/21/2021] [Indexed: 11/27/2022] Open
Abstract
In the last years, it has become evident that both acute and chronic physical exercise trigger responses/adaptations in the purinergic signaling and these adaptations can be considered one important mechanism related to the exercise benefits for health improvement. Purinergic system is composed of enzymes (ectonucleotidases), receptors (P1 and P2 families), and molecules (ATP, ADP, adenosine) that are able to activate these receptors. These components are widely distributed in almost all cell types, and they respond/act in a specific manner depending on the exercise types and/or intensities as well as the cell type (organ/tissue analyzed). For example, while acute intense exercise can be associated with tissue damage, inflammation, and platelet aggregation, chronic exercise exerts anti-inflammatory and anti-aggregant effects, promoting health and/or treating diseases. All of these effects are dependent on the purinergic signaling. Thus, this review was designed to cover the aspects related to the relationship between physical exercise and purinergic signaling, with emphasis on the modulation of ectonucleotidases and receptors. Here, we discuss the impact of different exercise protocols as well as the differences between acute and chronic effects of exercise on the extracellular signaling exerted by purinergic system components. We also reinforce the concept that purinergic signaling must be understood/considered as a mechanism by which exercise exerts its effects.
Collapse
Affiliation(s)
- Andréia Machado Cardoso
- Graduate Program in Biomedical Sciences and Medicine Course, Federal University of Fronteira Sul - UFFS, Campus Chapecó, Rodovia SC 484 - Km 02, Fronteira Sul, 89815-899, Brazil.
- Graduate Program in Physical Education, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
| | - Mauro Nicollas Oliveira Silvério
- Medicine Course, Federal University of Fronteira Sul - UFFS, Campus Chapecó, Rodovia SC 484 - Km 02, Fronteira Sul, 89815-899, Brazil
| | - Sarah Franco Vieira de Oliveira Maciel
- Graduate Program in Biomedical Sciences and Medicine Course, Federal University of Fronteira Sul - UFFS, Campus Chapecó, Rodovia SC 484 - Km 02, Fronteira Sul, 89815-899, Brazil
| |
Collapse
|
6
|
Bardsley EN, Pen DK, McBryde FD, Ford AP, Paton JFR. The inevitability of ATP as a transmitter in the carotid body. Auton Neurosci 2021; 234:102815. [PMID: 33993068 DOI: 10.1016/j.autneu.2021.102815] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/10/2021] [Accepted: 05/05/2021] [Indexed: 12/13/2022]
Abstract
Atmospheric oxygen concentrations rose markedly at several points in evolutionary history. Each of these increases was followed by an evolutionary leap in organismal complexity, and thus the cellular adaptions we see today have been shaped by the levels of oxygen within our atmosphere. In eukaryotic cells, oxygen is essential for the production of adenosine 5'-triphosphate (ATP) which is the 'Universal Energy Currency' of life. Aerobic organisms survived by evolving precise mechanisms for converting oxygen within the environment into energy. Higher mammals developed specialised organs for detecting and responding to changes in oxygen content to maintain gaseous homeostasis for survival. Hypoxia is sensed by the carotid bodies, the primary chemoreceptor organs which utilise multiple neurotransmitters one of which is ATP to evoke compensatory reflexes. Yet, a paradox is presented in oxygen sensing cells of the carotid body when during periods of low oxygen, ATP is seemingly released in abundance to transmit this signal although the synthesis of ATP is theoretically halted because of its dependence on oxygen. We propose potential mechanisms to maintain ATP production in hypoxia and summarise recent data revealing elevated sensitivity of purinergic signalling within the carotid body during conditions of sympathetic overactivity and hypertension. We propose the carotid body is hypoxic in numerous chronic cardiovascular and respiratory diseases and highlight the therapeutic potential for modulating purinergic transmission.
Collapse
Affiliation(s)
- Emma N Bardsley
- Auckland University, Department of Physiology, Faculty of Health and Medical Sciences, 85 Park Road, Grafton 1023, New Zealand
| | - Dylan K Pen
- Auckland University, Department of Physiology, Faculty of Health and Medical Sciences, 85 Park Road, Grafton 1023, New Zealand
| | - Fiona D McBryde
- Auckland University, Department of Physiology, Faculty of Health and Medical Sciences, 85 Park Road, Grafton 1023, New Zealand
| | - Anthony P Ford
- CuraSen, 930 Brittan Avenue #306, San Carlos, CA 94070, USA
| | - Julian F R Paton
- Auckland University, Department of Physiology, Faculty of Health and Medical Sciences, 85 Park Road, Grafton 1023, New Zealand.
| |
Collapse
|
7
|
Van Schaik L, Kettle C, Green R, Irving HR, Rathner JA. Effects of Caffeine on Brown Adipose Tissue Thermogenesis and Metabolic Homeostasis: A Review. Front Neurosci 2021; 15:621356. [PMID: 33613184 PMCID: PMC7889509 DOI: 10.3389/fnins.2021.621356] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/11/2021] [Indexed: 12/11/2022] Open
Abstract
The impact of brown adipose tissue (BAT) metabolism on understanding energy balance in humans is a relatively new and exciting field of research. The pathogenesis of obesity can be largely explained by an imbalance between caloric intake and energy expenditure, but the underlying mechanisms are far more complex. Traditional non-selective sympathetic activators have been used to artificially elevate energy utilization, or suppress appetite, however undesirable side effects are apparent with the use of these pharmacological interventions. Understanding the role of BAT, in relation to human energy homeostasis has the potential to dramatically offset the energy imbalance associated with obesity. This review discusses paradoxical effects of caffeine on peripheral adenosine receptors and the possible role of adenosine in increasing metabolism is highlighted, with consideration to the potential of central rather than peripheral mechanisms for caffeine mediated BAT thermogenesis and energy expenditure. Research on the complex physiology of adipose tissue, the embryonic lineage and function of the different types of adipocytes is summarized. In addition, the effect of BAT on overall human metabolism and the extent of the associated increase in energy expenditure are discussed. The controversy surrounding the primary β-adrenoceptor involved in human BAT activation is examined, and suggestions as to the lack of translational findings from animal to human physiology and human in vitro to in vivo models are provided. This review compares and distinguishes human and rodent BAT effects, thus developing an understanding of human BAT thermogenesis to aid lifestyle interventions targeting obesity and metabolic syndrome. The focus of this review is on the effect of BAT thermogenesis on overall metabolism, and the potential therapeutic effects of caffeine in increasing metabolism via its effects on BAT.
Collapse
Affiliation(s)
- Lachlan Van Schaik
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Christine Kettle
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Rodney Green
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Helen R. Irving
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Joseph A. Rathner
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
- Department of Physiology, School of Biomedical Sciences, The University of Melbourne, Melbourne, VIC, Australia
| |
Collapse
|
8
|
Huang CC, Chiu TY, Lee TY, Hsieh HJ, Lin CC, Kao LS. Soluble α-synuclein facilitates priming and fusion by releasing Ca 2+ from the thapsigargin-sensitive Ca 2+ pool in PC12 cells. J Cell Sci 2018; 131:jcs.213017. [PMID: 30404828 DOI: 10.1242/jcs.213017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 10/12/2018] [Indexed: 02/01/2023] Open
Abstract
α-Synuclein is associated with Parkinson's disease, and is mainly localized in presynaptic terminals and regulates exocytosis, but its physiological roles remain controversial. Here, we studied the effects of soluble and aggregated α-synuclein on exocytosis, and explored the molecular mechanism by which α-synuclein interacts with regulatory proteins, including Rab3A, Munc13-1 (also known as Unc13a) and Munc18-1 (also known as STXBP1), in order to regulate exocytosis. Through fluorescence recovery after photobleaching experiments, overexpressed α-synuclein in PC12 cells was found to be in a monomeric form, which promotes exocytosis. In contrast, aggregated α-synuclein induced by lactacystin treatment inhibits exocytosis. Our results show that α-synuclein is involved in vesicle priming and fusion. α-Synuclein and phorbol 12-myristate 13-acetate (PMA), which is known to enhance vesicle priming mediated by Rab3A, Munc13-1 and Munc18-1, act on the same population of vesicles, but regulate priming independently. Furthermore, the results show a novel effects of α-synuclein on mobilizing Ca2+ release from thapsigargin-sensitive Ca2+ pools to enhance the ATP-induced [Ca2+]i increase, which enhances vesicle fusion. Our results provide a detailed understanding of the action of α-synuclein during the final steps of exocytosis.
Collapse
Affiliation(s)
- Chien-Chang Huang
- Brain Research Center, National Yang-Ming University, Taipei 112, Taiwan, Republic of China.,Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan, Republic of China
| | - Tai-Yu Chiu
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan, Republic of China
| | - Tzu-Ying Lee
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan, Republic of China
| | - Hsin-Jui Hsieh
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan, Republic of China
| | - Chung-Chih Lin
- Brain Research Center, National Yang-Ming University, Taipei 112, Taiwan, Republic of China .,Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan, Republic of China.,Biophotonics Interdisciplinary Research Center, National Yang-Ming University, Taipei 112, Taiwan, Republic of China
| | - Lung-Sen Kao
- Brain Research Center, National Yang-Ming University, Taipei 112, Taiwan, Republic of China .,Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan, Republic of China
| |
Collapse
|
9
|
Zhu G, Chen Z, Dai B, Zheng C, Jiang H, Xu Y, Sheng X, Guo J, Dan Y, Liang S, Li G. Chronic lead exposure enhances the sympathoexcitatory response associated with P2X4 receptor in rat stellate ganglia. ENVIRONMENTAL TOXICOLOGY 2018; 33:631-639. [PMID: 29457680 DOI: 10.1002/tox.22547] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 01/25/2018] [Accepted: 02/03/2018] [Indexed: 06/08/2023]
Abstract
Chronic lead exposure causes peripheral sympathetic nerve stimulation, including increased blood pressure and heart rate. Purinergic receptors are involved in the sympathoexcitatory response induced by myocardial ischemia injury. However, whether P2X4 receptor participates in sympathoexcitatory response induced by chronic lead exposure and the possible mechanisms are still unknown. The aim of this study was to explore the change of the sympathoexcitatory response induced by chronic lead exposure via the P2X4 receptor in the stellate ganglion (SG). Rats were given lead acetate through drinking water freely at doses of 0 g/L (control group), 0.5 g/L (low lead group), and 2 g/L (high lead group) for 1 year. Our results demonstrated that lead exposure caused autonomic nervous dysfunction, including blood pressure and heart rate increased and heart rate variability (HRV) decreased. Western blotting results indicated that after lead exposure, the protein expression levels in the SG of P2X4 receptor, IL-1β and Cx43 were up-regulated, the phosphorylation of p38 mitogen-activated protein kinase (MAPK) was activated. Real-time PCR results showed that the mRNA expression of P2X4 receptor in the SG was higher in lead exposure group than that in the control group. Double-labeled immunofluorescence results showed that P2X4 receptor was co-expressed with glutamine synthetase (GS), the marker of satellite glial cells (SGCs). These changes were positively correlated with the dose of lead exposure. The up-regulated expression of P2X4 receptor in SGCs of the SG maybe enhance the sympathoexcitatory response induced by chronic lead exposure.
Collapse
Affiliation(s)
- Gaochun Zhu
- Department of Anatomy, Medical College of Nanchang University, Nanchang, China
| | - Zhenying Chen
- The Fourth Clinical, Medical College of Nanchang University, Nanchang, China
| | - Bo Dai
- The Fourth Clinical, Medical College of Nanchang University, Nanchang, China
| | - Chaoran Zheng
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Huaide Jiang
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Yurong Xu
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Xuan Sheng
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Jingjing Guo
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Yu Dan
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Shangdong Liang
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Guilin Li
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| |
Collapse
|
10
|
Haspula D, Clark MA. Molecular Basis of the Brain Renin Angiotensin System in Cardiovascular and Neurologic Disorders: Uncovering a Key Role for the Astroglial Angiotensin Type 1 Receptor AT1R. J Pharmacol Exp Ther 2018; 366:251-264. [PMID: 29752427 DOI: 10.1124/jpet.118.248831] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/08/2018] [Indexed: 12/13/2022] Open
Abstract
The central renin angiotensin system (RAS) is one of the most widely investigated cardiovascular systems in the brain. It is implicated in a myriad of cardiovascular diseases. However, studies from the last decade have identified its involvement in several neurologic abnormalities. Understanding the molecular functionality of the various RAS components can thus provide considerable insight into the phenotypic differences and mechanistic drivers of not just cardiovascular but also neurologic disorders. Since activation of one of its primary receptors, the angiotensin type 1 receptor (AT1R), results in an augmentation of oxidative stress and inflammatory cytokines, it becomes essential to investigate not just neuronal RAS but glial RAS as well. Glial cells are key homeostatic regulators in the brain and are critical players in the resolution of overt oxidative stress and neuroinflammation. Designing better and effective therapeutic strategies that target the brain RAS could well hinge on understanding the molecular basis of both neuronal and glial RAS. This review provides a comprehensive overview of the major studies that have investigated the mechanisms and regulation of the brain RAS, and it also provides insight into the potential role of glial AT1Rs in the pathophysiology of cardiovascular and neurologic disorders.
Collapse
Affiliation(s)
- Dhanush Haspula
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin (D.H.); and College of Pharmacy, Department of Pharmaceutical Sciences, Nova Southeastern University, Ft. Lauderdale, Florida (M.A.C.)
| | - Michelle A Clark
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin (D.H.); and College of Pharmacy, Department of Pharmaceutical Sciences, Nova Southeastern University, Ft. Lauderdale, Florida (M.A.C.)
| |
Collapse
|
11
|
Goldstein DS, Kopin IJ. Homeostatic systems, biocybernetics, and autonomic neuroscience. Auton Neurosci 2017; 208:15-28. [PMID: 28918243 PMCID: PMC5819891 DOI: 10.1016/j.autneu.2017.09.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 09/02/2017] [Accepted: 09/04/2017] [Indexed: 12/20/2022]
Abstract
In this review we describe a series of major concepts introduced during the past 150years that have contributed to our current understanding about how physiological processes required for well-being and survival are regulated. One can theorize that hierarchical networks involving input-output relationships continuously orchestrate and learn adaptive patterns of observable behaviors, cognition, memory, mood, and autonomic systems. Taken together, these networks function as "good regulators" determining levels of internal variables and act as if there were homeostatic comparators ("homeostats"). The consequences of models with vs. without homeostats remain the same in terms of allostatic load and the eventual switch from stabilizing negative feedback loops to destabilizing, pathogenic positive feedback loops. Understanding this switch seems important for comprehending senescence-related, neurodegenerative disorders that involve the autonomic nervous system. Our general proposal is that disintegration of homeostatic systems causes disorders of regulation in degenerative diseases and that medical cybernetics can inspire and rationalize new approaches to treatment and prevention.
Collapse
Affiliation(s)
- David S Goldstein
- Clinical Neurocardiology Section, Clinical Neurosciences Program, Division of Intramural Research, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1620, USA.
| | - Irwin J Kopin
- Clinical Neurocardiology Section, Clinical Neurosciences Program, Division of Intramural Research, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1620, USA
| |
Collapse
|
12
|
Zou L, Gong Y, Zhao S, Yi Z, Han X, Wu B, Jia T, Li L, Yuan H, Shi L, Zhang C, Gao Y, Li G, Xu H, Liu H, Liang S, Liu S. Downregulation of P2Y12in the superior cervical ganglia alleviates abnormal sympathetic activity after myocardial ischemia. J Cell Physiol 2017; 233:3375-3383. [DOI: 10.1002/jcp.26184] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 09/14/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Lifang Zou
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
| | - Yingxin Gong
- First Clinical Department; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
| | - Shanhong Zhao
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
| | - Zhihua Yi
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
- Nursing College; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
| | - Xinyao Han
- First Clinical Department; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
| | - Bing Wu
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
| | - Tianyu Jia
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
| | - Lin Li
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
| | - Huilong Yuan
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
| | - Liran Shi
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
| | - Chunping Zhang
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
- Department of Cell Biology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
| | - Yun Gao
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
| | - Guilin Li
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
| | - Hong Xu
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
| | - Hui Liu
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
| | - Shangdong Liang
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
| | - Shuangmei Liu
- Department of Physiology; Medical School of Nanchang University; Nanchang Jiangxi P.R. China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease; Nanchang Jiangxi P.R. China
| |
Collapse
|
13
|
Burnstock G. Short- and long-term (trophic) purinergic signalling. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0422. [PMID: 27377731 DOI: 10.1098/rstb.2015.0422] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2016] [Indexed: 12/26/2022] Open
Abstract
There is long-term (trophic) purinergic signalling involving cell proliferation, differentiation, motility and death in the development and regeneration of most systems of the body, in addition to fast purinergic signalling in neurotransmission, neuromodulation and secretion. It is not always easy to distinguish between short- and long-term signalling. For example, adenosine triphosphate (ATP) can sometimes act as a short-term trigger for long-term trophic events that become evident days or even weeks after the original challenge. Examples of short-term purinergic signalling during sympathetic, parasympathetic and enteric neuromuscular transmission and in synaptic transmission in ganglia and in the central nervous system are described, as well as in neuromodulation and secretion. Long-term trophic signalling is described in the immune/defence system, stratified epithelia in visceral organs and skin, embryological development, bone formation and resorption and in cancer. It is likely that the increase in intracellular Ca(2+) in response to both P2X and P2Y purinoceptor activation participates in many short- and long-term physiological effects.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'.
Collapse
Affiliation(s)
- Geoffrey Burnstock
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Victoria, Australia
| |
Collapse
|
14
|
Burnstock G. Purinergic Signaling in the Cardiovascular System. Circ Res 2017; 120:207-228. [PMID: 28057794 DOI: 10.1161/circresaha.116.309726] [Citation(s) in RCA: 271] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/21/2016] [Accepted: 11/23/2016] [Indexed: 02/07/2023]
Abstract
There is nervous control of the heart by ATP as a cotransmitter in sympathetic, parasympathetic, and sensory-motor nerves, as well as in intracardiac neurons. Centers in the brain control heart activities and vagal cardiovascular reflexes involve purines. Adenine nucleotides and nucleosides act on purinoceptors on cardiomyocytes, AV and SA nodes, cardiac fibroblasts, and coronary blood vessels. Vascular tone is controlled by a dual mechanism. ATP, released from perivascular sympathetic nerves, causes vasoconstriction largely via P2X1 receptors. Endothelial cells release ATP in response to changes in blood flow (via shear stress) or hypoxia, to act on P2 receptors on endothelial cells to produce nitric oxide, endothelium-derived hyperpolarizing factor, or prostaglandins to cause vasodilation. ATP is also released from sensory-motor nerves during antidromic reflex activity, to produce relaxation of some blood vessels. Purinergic signaling is involved in the physiology of erythrocytes, platelets, and leukocytes. ATP is released from erythrocytes and platelets, and purinoceptors and ectonucleotidases are expressed by these cells. P1, P2Y1, P2Y12, and P2X1 receptors are expressed on platelets, which mediate platelet aggregation and shape change. Long-term (trophic) actions of purine and pyrimidine nucleosides and nucleotides promote migration and proliferation of vascular smooth muscle and endothelial cells via P1 and P2Y receptors during angiogenesis, vessel remodeling during restenosis after angioplasty and atherosclerosis. The involvement of purinergic signaling in cardiovascular pathophysiology and its therapeutic potential are discussed, including heart failure, infarction, arrhythmias, syncope, cardiomyopathy, angina, heart transplantation and coronary bypass grafts, coronary artery disease, diabetic cardiomyopathy, hypertension, ischemia, thrombosis, diabetes mellitus, and migraine.
Collapse
Affiliation(s)
- Geoffrey Burnstock
- From the Autonomic Neuroscience Institute, Royal Free and University College Medical School, London, United Kingdom.
| |
Collapse
|
15
|
Huckstepp RTR, Llaudet E, Gourine AV. CO2-Induced ATP-Dependent Release of Acetylcholine on the Ventral Surface of the Medulla Oblongata. PLoS One 2016; 11:e0167861. [PMID: 27936179 PMCID: PMC5148032 DOI: 10.1371/journal.pone.0167861] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 11/21/2016] [Indexed: 12/04/2022] Open
Abstract
Complex mechanisms that detect changes in brainstem parenchymal PCO2/[H+] and trigger adaptive changes in lung ventilation are responsible for central respiratory CO2 chemosensitivity. Previous studies of chemosensory signalling pathways suggest that at the level of the ventral surface of the medulla oblongata (VMS), CO2-induced changes in ventilation are (at least in part) mediated by the release and actions of ATP and/or acetylcholine (ACh). Here we performed simultaneous real-time biosensor recordings of CO2-induced ATP and ACh release from the VMS in vivo and in vitro, to test the hypothesis that central respiratory CO2 chemosensory transduction involves simultaneous recruitment of purinergic and cholinergic signalling pathways. In anaesthetised and artificially ventilated rats, an increase in inspired CO2 triggered ACh release on the VMS with a peak amplitude of ~5 μM. Release of ACh was only detected after the onset of CO2-induced activation of the respiratory activity and was markedly reduced (by ~70%) by ATP receptor blockade. In horizontal slices of the VMS, CO2-induced release of ATP was reliably detected, whereas CO2 or bath application of ATP (100 μM) failed to trigger release of ACh. These results suggest that during hypercapnia locally produced ATP induces or potentiates the release of ACh (likely from the medullary projections of distal groups of cholinergic neurones), which may also contribute to the development and/or maintenance of the ventilatory response to CO2.
Collapse
Affiliation(s)
- Robert T. R. Huckstepp
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Enrique Llaudet
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Alexander V. Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| |
Collapse
|
16
|
Barna BF, Takakura AC, Mulkey DK, Moreira TS. Purinergic receptor blockade in the retrotrapezoid nucleus attenuates the respiratory chemoreflexes in awake rats. Acta Physiol (Oxf) 2016; 217:80-93. [PMID: 26647910 DOI: 10.1111/apha.12637] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 10/06/2015] [Accepted: 11/26/2015] [Indexed: 01/21/2023]
Abstract
AIM Recent evidence suggests that adenosine triphosfate (ATP)-mediated purinergic signalling at the level of the rostral ventrolateral medulla contributes to both central and peripheral chemoreceptor control of breathing and blood pressure: neurones in the retrotrapezoid nucleus (RTN) function as central chemoreceptors in part by responding to CO2 -evoked ATP release by activation of yet unknown P2 receptors, and nearby catecholaminergic C1 neurones regulate blood pressure responses to peripheral chemoreceptor activation by a P2Y1 receptor-dependent mechanism. However, potential contributions of purinergic signalling in the RTN to cardiorespiratory function in conscious animals have not been tested. METHODS Cardiorespiratory activity of unrestrained awake rats was measured in response to RTN injections of ATP, and during exposure to hypercapnia (7% CO2 ) or hypoxia (8% O2 ) under control conditions and after bilateral RTN injections of P2 receptor blockers (PPADS or MRS2179). RESULTS Unilateral injection of ATP into the RTN increased cardiorespiratory output by a P2-receptor-dependent mechanism. We also show that bilateral RTN injections of a non-specific P2 receptor blocker (pyridoxal-phosphate-6-azophenyl-2',4'-disulfonate (PPADS) reduced the ventilatory response to hypercapnia (7% CO2 ) and hypoxia (8% O2 ) in unanesthetized rats. Conversely, bilateral injections of a specific P2Y1 receptor blocker (MRS2179) into the RTN had no measurable effect on ventilatory responses elicited by hypercapnia or hypoxia. CONCLUSION These data exclude P2Y1 receptor involvement in the chemosensory control of breathing at the level of the RTN and show that ATP-mediated purinergic signalling contributes to central and peripheral chemoreflex control of breathing and blood pressure in awake rats.
Collapse
Affiliation(s)
- B. F. Barna
- Department of Physiology and Biophysics; Institute of Biomedical Science; University of São Paulo; São Paulo SP Brazil
| | - A. C. Takakura
- Department of Pharmacology; Institute of Biomedical Science; University of São Paulo; São Paulo SP Brazil
| | - D. K. Mulkey
- Department of Physiology and Neurobiology; University of Connecticut; Storrs CT USA
| | - T. S. Moreira
- Department of Physiology and Biophysics; Institute of Biomedical Science; University of São Paulo; São Paulo SP Brazil
| |
Collapse
|
17
|
The effects of NONRATT021972 lncRNA siRNA on PC12 neuronal injury mediated by P2X7 receptor after exposure to oxygen-glucose deprivation. Purinergic Signal 2016; 12:479-87. [PMID: 27100355 DOI: 10.1007/s11302-016-9513-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 04/14/2016] [Indexed: 12/13/2022] Open
Abstract
Adenosine triphosphate (ATP) participates in signal transmission by acting on P2X receptors, and the P2X7 receptor is involved in the pathophysiological changes of ischemic injury. The PC12 cell line is a popular model system to study sympathetic neuronal function. Long noncoding RNAs (lncRNAs) are highly expressed in the nervous system and serve as regulatory RNAs. In this study, the effects of NONRATT021972 lncRNA siRNA on P2X7-mediated PC12 neuronal injury after exposure to oxygen-glucose deprivation (OGD) were investigated. Our results showed that the viability of PC12 cells cultured with OGD or the P2X7 agonist BzATP was significantly decreased. Treatment with NONRATT021972 siRNA reversed the decreased viability of PC12 cells under OGD conditions. The upregulated P2X7 mRNA and protein levels in PC12 cells under OGD conditions or BzATP treatment were significantly decreased when pretreated with NONRATT021972 siRNA. Moreover, NONRATT021972 siRNA treatment effectively suppressed the increase in [Ca(2+)]i induced by OGD or P2X7 agonists (ATP or BzATP) in PC12 cells. Therefore, treatment with NONRATT021972 siRNA may decrease sympathetic neuronal injury induced by ischemia.
Collapse
|
18
|
Marina N, Teschemacher AG, Kasparov S, Gourine AV. Glia, sympathetic activity and cardiovascular disease. Exp Physiol 2016; 101:565-76. [PMID: 26988631 PMCID: PMC5031202 DOI: 10.1113/ep085713] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 03/10/2016] [Indexed: 12/13/2022]
Abstract
NEW FINDINGS What is the topic of this review? In this review, we discuss recent findings that provide a novel insight into the mechanisms that link glial cell function with the pathogenesis of cardiovascular disease, including systemic arterial hypertension and chronic heart failure. What advances does it highlight? We discuss how glial cells may influence central presympathetic circuits, leading to maladaptive and detrimental increases in sympathetic activity and contributing to the development and progression of cardiovascular disease. Increased activity of the sympathetic nervous system is associated with the development of cardiovascular disease and may contribute to its progression. Vasomotor and cardiac sympathetic activities are generated by the neuronal circuits located in the hypothalamus and the brainstem. These neuronal networks receive multiple inputs from the periphery and other parts of the CNS and, at a local level, may be influenced by their non-neuronal neighbours, in particular glial cells. In this review, we discuss recent experimental evidence suggesting that astrocytes and microglial cells are able to modulate the activity of sympathoexcitatory neural networks in disparate physiological and pathophysiological conditions. We focus on the chemosensory properties of astrocytes residing in the rostral ventrolateral medulla oblongata and discuss signalling mechanisms leading to glial activation during brain hypoxia and inflammation. Alterations in these mechanisms may lead to heightened activity of sympathoexcitatory CNS circuits and contribute to maladaptive and detrimental increases in sympathetic tone associated with systemic arterial hypertension and chronic heart failure.
Collapse
Affiliation(s)
- Nephtali Marina
- Department of Clinical Pharmacology, University College London, London, WC1E 6JF, UK
| | - Anja G Teschemacher
- School of Physiology and Pharmacology, Medical Sciences Building, Bristol Heart Institute, University of Bristol, Bristol, BS8 1TD, UK
| | - Sergey Kasparov
- School of Physiology and Pharmacology, Medical Sciences Building, Bristol Heart Institute, University of Bristol, Bristol, BS8 1TD, UK
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & Pharmacology, University College London, London, WC1E 6BT, UK
| |
Collapse
|
19
|
Razzoli M, Frontini A, Gurney A, Mondini E, Cubuk C, Katz LS, Cero C, Bolan PJ, Dopazo J, Vidal-Puig A, Cinti S, Bartolomucci A. Stress-induced activation of brown adipose tissue prevents obesity in conditions of low adaptive thermogenesis. Mol Metab 2016; 5:19-33. [PMID: 26844204 PMCID: PMC4703853 DOI: 10.1016/j.molmet.2015.10.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Revised: 10/09/2015] [Accepted: 10/13/2015] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Stress-associated conditions such as psychoemotional reactivity and depression have been paradoxically linked to either weight gain or weight loss. This bi-directional effect of stress is not understood at the functional level. Here we tested the hypothesis that pre-stress level of adaptive thermogenesis and brown adipose tissue (BAT) functions explain the vulnerability or resilience to stress-induced obesity. METHODS We used wt and triple β1,β2,β3-Adrenergic Receptors knockout (β-less) mice exposed to a model of chronic subordination stress (CSS) at either room temperature (22 °C) or murine thermoneutrality (30 °C). A combined behavioral, physiological, molecular, and immunohistochemical analysis was conducted to determine stress-induced modulation of energy balance and BAT structure and function. Immortalized brown adipocytes were used for in vitro assays. RESULTS Departing from our initial observation that βARs are dispensable for cold-induced BAT browning, we demonstrated that under physiological conditions promoting low adaptive thermogenesis and BAT activity (e.g. thermoneutrality or genetic deletion of the βARs), exposure to CSS acted as a stimulus for BAT activation and thermogenesis, resulting in resistance to diet-induced obesity despite the presence of hyperphagia. Conversely, in wt mice acclimatized to room temperature, and therefore characterized by sustained BAT function, exposure to CSS increased vulnerability to obesity. Exposure to CSS enhanced the sympathetic innervation of BAT in wt acclimatized to thermoneutrality and in β-less mice. Despite increased sympathetic innervation suggesting adrenergic-mediated browning, norepinephrine did not promote browning in βARs knockout brown adipocytes, which led us to identify an alternative sympathetic/brown adipocytes purinergic pathway in the BAT. This pathway is downregulated under conditions of low adaptive thermogenesis requirements, is induced by stress, and elicits activation of UCP1 in wt and β-less brown adipocytes. Importantly, this purinergic pathway is conserved in human BAT. CONCLUSION Our findings demonstrate that thermogenesis and BAT function are determinant of the resilience or vulnerability to stress-induced obesity. Our data support a model in which adrenergic and purinergic pathways exert complementary/synergistic functions in BAT, thus suggesting an alternative to βARs agonists for the activation of human BAT.
Collapse
Affiliation(s)
- Maria Razzoli
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Andrea Frontini
- Department of Experimental and Clinical Medicine, Center for Obesity, Università Politecnica delle Marche, Ancona 60020, Italy
| | - Allison Gurney
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Eleonora Mondini
- Department of Experimental and Clinical Medicine, Center for Obesity, Università Politecnica delle Marche, Ancona 60020, Italy
| | - Cankut Cubuk
- Computational Genomics Department, Centro de Investigación Príncipe Felipe, C/ Eduardo Primo Yufera 3, 46012 Valencia, Spain
| | - Liora S. Katz
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Cheryl Cero
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Patrick J. Bolan
- Department of Radiology and Center for Magnetic Resonance Research, University of Minnesota, MN 55455, USA
| | - Joaquin Dopazo
- Computational Genomics Department, Centro de Investigación Príncipe Felipe, C/ Eduardo Primo Yufera 3, 46012 Valencia, Spain
| | - Antonio Vidal-Puig
- University of Cambridge Metabolic Research Laboratories, Cambridge CB2 OQQ, UK
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Saverio Cinti
- Department of Experimental and Clinical Medicine, Center for Obesity, Università Politecnica delle Marche, Ancona 60020, Italy
| | - Alessandro Bartolomucci
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN 55455, USA
| |
Collapse
|
20
|
Burnstock G. Purinergic signalling and the autonomic nervous system in health and disease. Auton Neurosci 2015; 191:1. [DOI: 10.1016/j.autneu.2015.05.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
21
|
Cardoso AM, Schetinger MRC, Correia-de-Sá P, Sévigny J. Impact of ectonucleotidases in autonomic nervous functions. Auton Neurosci 2015; 191:25-38. [PMID: 26008223 DOI: 10.1016/j.autneu.2015.04.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 04/28/2015] [Accepted: 04/29/2015] [Indexed: 01/05/2023]
Abstract
Adenine and uracil nucleotides play key functions in the autonomic nervous system (ANS). For instance, ATP acts as a neurotransmitter, co-transmitter and neuromodulator in the ANS. The purinergic system encompasses (1) receptors that respond to extracellular purines, which are designated as P1 and P2 purinoceptors, (2) purine release and uptake, and (3) a cascade of enzymes that regulate the concentration of purines near the cell surface. Ectonucleotidases and adenosine deaminase (ADA) are enzymes responsible for the hydrolysis of ATP (and other nucleotides such as ADP, UTP, UDP, AMP) and adenosine, respectively. Accordingly, these enzymes are expected to play an important role in the control of neuro-effector transmission in tissues innervated by both the sympathetic and parasympathetic divisions of the ANS. Indeed, ectonucleotidases have the ability to either terminate P2 receptor responses initiated by nucleoside triphosphates (ATP and UTP), and/or to favor the activation of ADP (e.g. P2Y1,12,13) and UDP (e.g. P2Y6) and/or adenosine (P1) specific receptors. In addition, ectonucleotidases can also importantly protect some P2 receptors from desensitization (e.g. P2X1, P2Y1). In this review, we present the (putative) roles of ectonucleotidases and ADA in the ANS with a focus on their regulatory activity at neuro-effector junctions in the following tissues: heart, vas deferens, urinary bladder, salivary glands, blood vessels and the intestine. We also present their implication in nociceptive transmission.
Collapse
Affiliation(s)
- Andréia Machado Cardoso
- Post-Graduation Program in Toxicological Biochemistry, Department of Biochemistry and Molecular Biology of the Center of Natural and Exact Sciences of the Federal University of Santa Maria, Santa Maria Rio Grande do Sul, Brazil; Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec City, Québec G1V 0A6, Canada; Centre de Recherche du CHU de Québec - Université Laval, Québec G1V 4G2, Canada.
| | - Maria Rosa Chitolina Schetinger
- Post-Graduation Program in Toxicological Biochemistry, Department of Biochemistry and Molecular Biology of the Center of Natural and Exact Sciences of the Federal University of Santa Maria, Santa Maria Rio Grande do Sul, Brazil
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia, MedInUP, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), 4050-313 Porto, Portugal
| | - Jean Sévigny
- Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec City, Québec G1V 0A6, Canada; Centre de Recherche du CHU de Québec - Université Laval, Québec G1V 4G2, Canada.
| |
Collapse
|
22
|
Moreira TS, Wenker IC, Sobrinho CR, Barna BF, Takakura AC, Mulkey DK. Independent purinergic mechanisms of central and peripheral chemoreception in the rostral ventrolateral medulla. J Physiol 2015; 593:1067-74. [PMID: 25524282 DOI: 10.1113/jphysiol.2014.284430] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 12/15/2014] [Indexed: 01/02/2023] Open
Abstract
The rostral ventrolateral medulla oblongata (RVLM) contains two functionally distinct types of neurons that control and orchestrate cardiovascular and respiratory responses to hypoxia and hypercapnia. One group is composed of the central chemoreceptor neurons of the retrotrapezoid nucleus, which provides a CO₂/H(+) -dependent drive to breathe and serves as an integration centre and a point of convergence of chemosensory information from other central and peripheral sites, including the carotid bodies. The second cluster of RVLM cells forms a population of neurons belonging to the C1 catecholaminergic group that controls sympathetic vasomotor tone in resting conditions and in conditions of hypoxia and hypercapnia. Recent evidence suggests that ATP-mediated purinergic signalling at the level of the RVLM co-ordinates cardiovascular and respiratory responses triggered by hypoxia and hypercapnia by activating retrotrapezoid nucleus and C1 neurons, respectively. The role of ATP-mediated signalling in the RVLM mechanisms of cardiovascular and respiratory activities is the main subject of this short review.
Collapse
Affiliation(s)
- Thiago S Moreira
- Department of Physiology and Biophysics, University of São Paulo, São Paulo, SP, 05508, Brazil
| | | | | | | | | | | |
Collapse
|
23
|
Naviaux JC, Wang L, Li K, Bright AT, Alaynick WA, Williams KR, Powell SB, Naviaux RK. Antipurinergic therapy corrects the autism-like features in the Fragile X (Fmr1 knockout) mouse model. Mol Autism 2015; 6:1. [PMID: 25705365 PMCID: PMC4334917 DOI: 10.1186/2040-2392-6-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 12/16/2014] [Indexed: 02/07/2023] Open
Abstract
Background This study was designed to test a new approach to drug treatment of autism spectrum disorders (ASDs) in the Fragile X (Fmr1) knockout mouse model. Methods We used behavioral analysis, mass spectrometry, metabolomics, electron microscopy, and western analysis to test the hypothesis that the disturbances in social behavior, novelty preference, metabolism, and synapse structure are treatable with antipurinergic therapy (APT). Results Weekly treatment with the purinergic antagonist suramin (20 mg/kg intraperitoneally), started at 9 weeks of age, restored normal social behavior, and improved metabolism, and brain synaptosomal structure. Abnormalities in synaptosomal glutamate, endocannabinoid, purinergic, and IP3 receptor expression, complement C1q, TDP43, and amyloid β precursor protein (APP) were corrected. Comprehensive metabolomic analysis identified 20 biochemical pathways associated with symptom improvements. Seventeen pathways were shared with human ASD, and 11 were shared with the maternal immune activation (MIA) model of ASD. These metabolic pathways were previously identified as functionally related mediators of the evolutionarily conserved cell danger response (CDR). Conclusions The data show that antipurinergic therapy improves the multisystem, ASD-like features of both the environmental MIA, and the genetic Fragile X models. These abnormalities appeared to be traceable to mitochondria and regulated by purinergic signaling. Electronic supplementary material The online version of this article (doi:10.1186/2040-2392-6-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Jane C Naviaux
- Department of Psychiatry, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA
| | - Lin Wang
- The Mitochondrial and Metabolic Disease Center, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA ; Department of Medicine, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA
| | - Kefeng Li
- The Mitochondrial and Metabolic Disease Center, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA ; Department of Medicine, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA
| | - A Taylor Bright
- The Mitochondrial and Metabolic Disease Center, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA ; Department of Medicine, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA
| | - William A Alaynick
- The Mitochondrial and Metabolic Disease Center, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA ; Department of Medicine, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA
| | - Kenneth R Williams
- The Mitochondrial and Metabolic Disease Center, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA ; Department of Medicine, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA ; General Atomics, Inc, San Diego, CA USA
| | - Susan B Powell
- Department of Psychiatry, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA ; Research Service, VA San Diego Healthcare System, La Jolla, CA USA
| | - Robert K Naviaux
- The Mitochondrial and Metabolic Disease Center, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA ; Department of Medicine, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA ; Department of Pediatrics, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA ; Department of Pathology, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467 USA ; Veterans Affairs Center for Excellence in Stress and Mental Health (CESAMH), La Jolla, CA USA
| |
Collapse
|
24
|
Zhang J, Liu S, Xu B, Li G, Li G, Huang A, Wu B, Peng L, Song M, Xie Q, Lin W, Xie W, Wen S, Zhang Z, Xu X, Liang S. Study of baicalin on sympathoexcitation induced by myocardial ischemia via P2X3 receptor in superior cervical ganglia. Auton Neurosci 2014; 189:8-15. [PMID: 25554221 DOI: 10.1016/j.autneu.2014.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 12/05/2014] [Accepted: 12/09/2014] [Indexed: 10/24/2022]
Abstract
After the myocardial ischemia, injured myocardial tissues released large quantity of ATP, which activated P2X3 receptor in superior cervical ganglia and made the SCG postganglionic neurons excited. Excitatory of sympathetic postganglionic efferent neurons increased the blood pressure and heart rates, which aggravated the myocardial ischemic injury. Baicalin has anti-inflammatory and anti-oxidant properties. Our study showed that baicalin reduced the incremental concentration of serum CK-MB, cTn-T, epinephrine and ATP, decreased the up-regulated expression levels of P2X3 mRNA and protein in SCG after MI, and then inhibited the sympathetic excitatory activity triggered by MI injury. These results indicated that baicalin acted on P2X3 receptor was involved in the transmission of sympathetic excitation after the myocardial ischemic injury. Baicalin might decrease sympathetic activity via inhibiting P2X3 receptor in rat SCG to protect the myocardium.
Collapse
Affiliation(s)
- Jun Zhang
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Shuangmei Liu
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Baohua Xu
- Department of Laboratory Animal, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Guodong Li
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Guilin Li
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - An Huang
- Jiangxi University of Finance and Economics, Nanchang, Jiangxi 330006, PR China
| | - Bing Wu
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Lichao Peng
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Miaomiao Song
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Qiuyu Xie
- 2012 Grade of Department of Clinical Medicine of Nanchang University, Nanchang 330006, PR China
| | - Weijian Lin
- 2012 Grade of Department of Clinical Medicine of Nanchang University, Nanchang 330006, PR China
| | - Wei Xie
- 2012 Grade of Department of Clinical Medicine of Nanchang University, Nanchang 330006, PR China
| | - Shiyao Wen
- 2012 Grade of Department of Clinical Medicine of Nanchang University, Nanchang 330006, PR China
| | - Zhedong Zhang
- 2012 Grade of Department of Clinical Medicine of Nanchang University, Nanchang 330006, PR China
| | - Xiaoling Xu
- Department of Biomedical Engineering, Information Engineering College of Nanchang University, Nanchang 330006, PR China
| | - Shangdong Liang
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China; Institute of Life Science of Nanchang University, Nanchang 330006, PR China.
| |
Collapse
|
25
|
Gnad T, Scheibler S, von Kügelgen I, Scheele C, Kilić A, Glöde A, Hoffmann LS, Reverte-Salisa L, Horn P, Mutlu S, El-Tayeb A, Kranz M, Deuther-Conrad W, Brust P, Lidell ME, Betz MJ, Enerbäck S, Schrader J, Yegutkin GG, Müller CE, Pfeifer A. Adenosine activates brown adipose tissue and recruits beige adipocytes via A2A receptors. Nature 2014; 516:395-9. [DOI: 10.1038/nature13816] [Citation(s) in RCA: 263] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 09/01/2014] [Indexed: 02/06/2023]
|
26
|
Weng Z, Wu L, Lu Y, Wang L, Tan L, Dong M, Xin Y. Electroacupuncture diminishes P2X2 and P2X3 purinergic receptor expression in dorsal root ganglia of rats with visceral hypersensitivity. Neural Regen Res 2014; 8:802-8. [PMID: 25206727 PMCID: PMC4146084 DOI: 10.3969/j.issn.1673-5374.2013.09.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 02/22/2013] [Indexed: 02/06/2023] Open
Abstract
Electroacupuncture at Shangjuxu (ST37) and Tianshu (ST25) can improve visceral hypersensitivity in rats. Colorectal distension was used to establish a rat model of chronic visceral hypersensitivity. Immunohistochemistry was used to detect P2X2 and P2X3 receptor expression in dorsal root ganglia from rats with chronic visceral hypersensitivity. Results demonstrated that abdominal withdrawal reflex scores obviously increased following establishment of the model, indicating visceral hypersensitivity. Simultaneously, P2X2 and P2X3 receptor expression increased in dorsal root ganglia. After bilateral electroacupuncture at Shangjuxu and Tianshu, abdominal withdrawal reflex scores and P2X2 and P2X3 receptor expression decreased in rats with visceral hypersensitivity. These results indicated that electroacupuncture treatment improved visceral hypersensitivity in rats with irritable bowel syndrome by reducing P2X2 and P2X3 receptor expression in dorsal root ganglia.
Collapse
Affiliation(s)
- Zhijun Weng
- Shanghai Academy of Traditional Chinese Medicine, Shanghai 201203, China
| | - Luyi Wu
- Shanghai Academy of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yuan Lu
- Shanghai Academy of Traditional Chinese Medicine, Shanghai 201203, China
| | - Lidong Wang
- Shanghai Academy of Traditional Chinese Medicine, Shanghai 201203, China
| | - Linying Tan
- Shanghai Academy of Traditional Chinese Medicine, Shanghai 201203, China
| | - Ming Dong
- Shanghai Academy of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yuhu Xin
- Fudan University Shanghai Cancer Center, Shanghai 200032, China
| |
Collapse
|
27
|
Fan B, Liu S, Xu C, Liu J, Kong F, Li G, Zhang C, Gao Y, Xu H, Yu S, Zheng C, Peng L, Song M, Wu B, Lv Q, Zou L, Ying M, Zhang X, Liang S. The role of P2X7 receptor in PC12 cells after exposure to oxygen-glucose deprivation. Auton Neurosci 2014; 185:36-42. [PMID: 24746144 DOI: 10.1016/j.autneu.2014.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 03/10/2014] [Accepted: 03/24/2014] [Indexed: 12/13/2022]
Abstract
Adenosine triphosphate (ATP) plays an important role in signal transmission via acting on P2X receptors. P2X7 receptor is involved in pathophysiological changes of ischemic diseases. The PC12 cell line is a popular model system to study sympathetic neuronal function. In this study, the effects of P2X7 on the viability or [Ca(2+)]i in PC12 cells after exposure to oxygen-glucose deprivation (OGD) were investigated. The results showed that the viability of PC12 cells was decreased under the condition of OGD. BzATP, a P2X7 agonist, decreased the viability, while P2X7 antagonist oxATP or P2X7 siRNA reversed the viability of PC12 cells under the condition of OGD. The expression levels of P2X7 mRNA and protein in PC12 cells were up-regulated under the condition of OGD or BzATP treatment. The expression levels of P2X7 mRNA and protein were significantly decreased in OGD PC12 cells, which were pretreated with oxATP or P2X7 siRNA. It was also found that oxATP or P2X7 siRNA effectively suppressed the increase of [Ca(2+)]i induced by OGD. P2X7 agonist ATP or BzATP enhanced the [Ca(2+)]i rise induced by OGD in PC12 cells. The [Ca(2+)]i peak induced by ATP or BzATP in OGD group was decreased by ERK inhibitor U0126. Therefore, P2X7 antagonists or P2X7 siRNA could depress the sympathetic neuronal damage induced by ischemia.
Collapse
Affiliation(s)
- Bo Fan
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Shuangmei Liu
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Changshui Xu
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Jun Liu
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Fanjun Kong
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Guilin Li
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Chunping Zhang
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Yun Gao
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Hong Xu
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Shicheng Yu
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Chaoran Zheng
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Lichao Peng
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Miaomiao Song
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Bing Wu
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Qiulan Lv
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Lifang Zou
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Mofeng Ying
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Xi Zhang
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China
| | - Shangdong Liang
- Department of Physiology, Medical School of Nanchang University, Nanchang 330006, PR China.
| |
Collapse
|
28
|
Voss U, Turesson MF, Robaye B, Boeynaems JM, Olde B, Erlinge D, Ekblad E. The enteric nervous system of P2Y13 receptor null mice is resistant against high-fat-diet- and palmitic-acid-induced neuronal loss. Purinergic Signal 2014; 10:455-64. [PMID: 24510452 DOI: 10.1007/s11302-014-9408-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 01/21/2014] [Indexed: 12/20/2022] Open
Abstract
Gastrointestinal symptoms have a major impact on the quality of life and are becoming more prevalent in the western population. The enteric nervous system (ENS) is pivotal in regulating gastrointestinal functions. Purinergic neurotransmission conveys a range of short and long-term cellular effects. This study investigated the role of the ADP-sensitive P2Y13 receptor in lipid-induced enteric neuropathy. Littermate P2Y13 (+/+) and P2Y13 (-/-) mice were fed with either a normal diet (ND) or high-fat diet (HFD) for 6 months. The intestines were analysed for morphological changes as well as neuronal numbers and relative numbers of vasoactive intestinal peptide (VIP)- and neuronal nitric oxide synthase (nNOS)-containing neurons. Primary cultures of myenteric neurons from the small intestine of P2Y13 (+/+) or P2Y13 (-/-) mice were exposed to palmitic acid (PA), the P2Y13 receptor agonist 2meSADP and the antagonist MRS2211. Neuronal survival and relative number of VIP-containing neurons were analysed. In P2Y13 (+/+), but not in P2Y13 (-/-) mice, HFD caused a significant loss of myenteric neurons in both ileum and colon. In colon, the relative numbers of VIP-containing submucous neurons were significantly lower in the P2Y13 (-/-) mice compared with P2Y13 (+/+) mice. The relative numbers of nNOS-containing submucous colonic neurons increased in P2Y13 (+/+) HFD mice. HFD also caused ileal mucosal thinning in P2Y13 (+/+) and P2Y13 (-/-) mice, compared to ND fed mice. In vitro PA exposure caused loss of myenteric neurons from P2Y13 (+/+) mice while neurons from P2Y13 (-/-) mice were unaffected. Presence of MRS2211 prevented PA-induced neuronal loss in cultures from P2Y13 (+/+) mice. 2meSADP caused no change in survival of cultured neurons. P2Y13 receptor activation is of crucial importance in mediating the HFD- and PA-induced myenteric neuronal loss in mice. In addition, the results indicate a constitutive activation of enteric neuronal apoptosis by way of P2Y13 receptor stimulation.
Collapse
Affiliation(s)
- Ulrikke Voss
- Department of Experimental Medical Science, Lund University, Sölvegatan 19, Lund, BMC B11, SE-22184, Sweden,
| | | | | | | | | | | | | |
Collapse
|
29
|
Burnstock G, Ralevic V. Purinergic signaling and blood vessels in health and disease. Pharmacol Rev 2013; 66:102-92. [PMID: 24335194 DOI: 10.1124/pr.113.008029] [Citation(s) in RCA: 227] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Purinergic signaling plays important roles in control of vascular tone and remodeling. There is dual control of vascular tone by ATP released as a cotransmitter with noradrenaline from perivascular sympathetic nerves to cause vasoconstriction via P2X1 receptors, whereas ATP released from endothelial cells in response to changes in blood flow (producing shear stress) or hypoxia acts on P2X and P2Y receptors on endothelial cells to produce nitric oxide and endothelium-derived hyperpolarizing factor, which dilates vessels. ATP is also released from sensory-motor nerves during antidromic reflex activity to produce relaxation of some blood vessels. In this review, we stress the differences in neural and endothelial factors in purinergic control of different blood vessels. The long-term (trophic) actions of purine and pyrimidine nucleosides and nucleotides in promoting migration and proliferation of both vascular smooth muscle and endothelial cells via P1 and P2Y receptors during angiogenesis and vessel remodeling during restenosis after angioplasty are described. The pathophysiology of blood vessels and therapeutic potential of purinergic agents in diseases, including hypertension, atherosclerosis, ischemia, thrombosis and stroke, diabetes, and migraine, is discussed.
Collapse
Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London NW3 2PF, UK; and Department of Pharmacology, The University of Melbourne, Australia.
| | | |
Collapse
|
30
|
Potthoff SA, Stegbauer J, Becker J, Wagenhaeuser PJ, Duvnjak B, Rump LC, Vonend O. P2Y2 receptor deficiency aggravates chronic kidney disease progression. Front Physiol 2013; 4:234. [PMID: 24065922 PMCID: PMC3776930 DOI: 10.3389/fphys.2013.00234] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Accepted: 08/11/2013] [Indexed: 12/31/2022] Open
Abstract
Purinergic signaling is involved in a variety of physiological states. P2 receptors are mainly activated by adenosine triphosphate (ATP). Activation of specific P2Y receptor subtypes might influence progression of kidney disease. To investigate the in vivo effect of a particular P2 receptor subtype on chronic kidney disease progression, subtotal nephrectomy was performed on wild type (WT) and P2Y2 receptor knockout (KO) mice. During the observational period of 56 ± 2 days, survival of KO mice was inferior compared to WT mice after SNX. Subtotal nephrectomy reduced creatinine clearance in both groups of mice, but the decrease was significantly more pronounced in KO compared to WT mice (53.9 ± 7.7 vs. 84.3 ± 8.7μl/min at day 56). The KO mice also sustained a greater increase in systolic blood pressure after SNX compared to WT mice (177 ± 2 vs. 156 ± 7 mmHg) and a 2.5-fold increase in albuminuria compared to WT. In addition, WT kidneys showed a significant increase in remnant kidney mass 56 days after SNX, but significant attenuation of hypertrophy in KO mice was observed. In line with the observed hypertrophy in WT SNX mice, a significant dose-dependent increase in DNA synthesis, a marker of proliferation, was present in cultured WT glomerular epithelial cells upon ATP stimulation. Markers for tissue damage (TGF-β 1, PAI-1) and proinflammatory target genes (MCP1) were significantly upregulated in KO mice after SNX compared to WT SNX mice. In summary, deletion of the P2Y2 receptor leads to greater renal injury after SNX compared to WT mice. Higher systolic blood pressure and inability of compensatory hypertrophy in KO mice are likely causes for the accelerated progression of chronic kidney disease.
Collapse
Affiliation(s)
- Sebastian A Potthoff
- Department of Nephrology, Medical Faculty, University Duesseldorf Duesseldorf, Germany
| | | | | | | | | | | | | |
Collapse
|
31
|
Liu J, Li G, Peng H, Tu G, Kong F, Liu S, Gao Y, Xu H, Qiu S, Fan B, Zhu Q, Yu S, Zheng C, Wu B, Peng L, Song M, Wu Q, Li G, Liang S. Sensory-sympathetic coupling in superior cervical ganglia after myocardial ischemic injury facilitates sympathoexcitatory action via P2X7 receptor. Purinergic Signal 2013; 9:463-79. [PMID: 23754120 PMCID: PMC3757147 DOI: 10.1007/s11302-013-9367-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 05/13/2013] [Indexed: 12/17/2022] Open
Abstract
P2X receptors participate in cardiovascular regulation and disease. After myocardial ischemic injury, sensory-sympathetic coupling between rat cervical DRG nerves and superior cervical ganglia (SCG) facilitated sympathoexcitatory action via P2X7 receptor. The results showed that after myocardial ischemic injury, the systolic blood pressure, heart rate, serum cardiac enzymes, IL-6, and TNF-α were increased, while the levels of P2X7 mRNA and protein in SCG were also upregulated. However, these alterations diminished after treatment of myocardial ischemic (MI) rats with the P2X7 antagonist oxATP. After siRNA P2X7 in MI rats, the systolic blood pressure, heart rate, serum cardiac enzymes, the expression levels of the satellite glial cell (SGC) or P2X7 were significantly lower than those in MI group. The phosphorylation of ERK 1/2 in SCG participated in the molecular mechanism of the sympathoexcitatory action induced by the myocardial ischemic injury. Retrograde tracing test revealed the sprouting of CGRP or SP sensory nerves (the markers of sensory afferent fibers) from DRG to SCG neurons. The upregulated P2X7 receptor promoted the activation of SGCs in SCG, resulting in the formation of sensory-sympathetic coupling which facilitated the sympathoexcitatory action. P2X7 antagonist oxATP could inhibit the activation of SGCs and interrupt the formation of sensory-sympathetic coupling in SCG after the myocardial ischemic injury. Our findings may benefit the treatment of coronary heart disease and other cardiovascular diseases.
Collapse
Affiliation(s)
- Jun Liu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Guilin Li
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Haiying Peng
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Guihua Tu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Fanjun Kong
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Shuangmei Liu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Yun Gao
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Hong Xu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Shuyi Qiu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Bo Fan
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Qicheng Zhu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Shicheng Yu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Chaoran Zheng
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Bing Wu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Lichao Peng
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Miaomiao Song
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Qin Wu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Guodong Li
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Shangdong Liang
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
- />Key Laboratory of Basic Medicine, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| |
Collapse
|
32
|
Kong F, Liu S, Xu C, Liu J, Li G, Li G, Gao Y, Lin H, Tu G, Peng H, Qiu S, Fan B, Zhu Q, Yu S, Zheng C, Liang S. Electrophysiological studies of upregulated P2X7 receptors in rat superior cervical ganglia after myocardial ischemic injury. Neurochem Int 2013; 63:230-7. [DOI: 10.1016/j.neuint.2013.06.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2012] [Revised: 06/02/2013] [Accepted: 06/06/2013] [Indexed: 01/07/2023]
|
33
|
Fei G, Fang X, Wang GD, Liu S, Wang XY, Xia Y, Wood JD. Neurogenic mucosal bicarbonate secretion in guinea pig duodenum. Br J Pharmacol 2013; 168:880-90. [PMID: 22994306 DOI: 10.1111/j.1476-5381.2012.02218.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 08/24/2012] [Accepted: 08/31/2012] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE To test a hypothesis that: (i) duodenal pH and osmolarity are individually controlled at constant set points by negative feedback control centred in the enteric nervous system (ENS); (ii) the purinergic P2Y(1) receptor subtype is expressed by non-cholinergic secretomotor/vasodilator neurons, which represent the final common excitatory pathway from the ENS to the bicarbonate secretory glands. EXPERIMENTAL APPROACH Ussing chamber and pH-stat methods investigated involvement of the P2Y(1) receptor in neurogenic stimulation of mucosal bicarbonate (HCO(3)(-)) secretion in guinea pig duodenum. KEY RESULTS ATP increased HCO(3)(-) secretion with an EC(50) of 160 nM. MRS2179, a selective P2Y(1) purinergic receptor antagonist, suppressed ATP-evoked HCO(3)(-) secretion by 47% and Cl(-) secretion by 63%. Enteric neuronal blockade by tetrodotoxin or exposure to a selective vasoactive intestinal peptide (VIP, VPAC(1)) receptor antagonist suppressed ATP-evoked HCO(3)(-) secretion by 61 and 41%, respectively, and Cl- by 97 and 70% respectively. Pretreatment with the muscarinic antagonist, scopolamine did not alter ATP-evoked HCO3(-) or Cl(-) secretion. CONCLUSION AND IMPLICATIONS Whereas acid directly stimulates the mucosa to release ATP and stimulate HCO(3)(-) secretion in a cytoprotective manner, neurogenically evoked HCO(3)(-) secretion accounts for feedback control of optimal luminal pH for digestion. ATP stimulates duodenal HCO(3)(-) secretion through an excitatory action at purinergic P2Y(1) receptors on neurons in the submucosal division of the ENS. Stimulation of the VIPergic non-cholinergic secretomotor/vasodilator neurons, which are one of three classes of secretomotor neurons, accounts for most, if not all, of the neurogenic secretory response evoked by ATP.
Collapse
Affiliation(s)
- G Fei
- Department of Physiology and Cell Biology, Ohio State University College of Medicine, Columbus, OH, USA
| | | | | | | | | | | | | |
Collapse
|
34
|
Florian V, Caroline F, Francis C, Camille S, Fabielle A. Leptin modulates enteric neurotransmission in the rat proximal colon: an in vitro study. ACTA ACUST UNITED AC 2013; 185:73-8. [PMID: 23816465 DOI: 10.1016/j.regpep.2013.06.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 03/21/2013] [Accepted: 06/20/2013] [Indexed: 12/13/2022]
Abstract
Leptin has been shown to modulate gastrointestinal functions including nutrient absorption, growth, and inflammation and to display complex effects on gut motility. Leptin receptors have also been identified within the enteric nervous system (ENS), which plays a crucial role in digestive functions. Although leptin has recently been shown to activate neurons in the ENS, the precise mechanisms involved are so far unknown. Therefore, the aim of the present study was to determine the effects of leptin on rat proximal colon smooth muscle and enteric neuron activities. The effects of exogenous leptin on tone and on responses to transmural nerve stimulation (TNS) of isolated circular smooth muscle of proximal colon in rats were investigated using an organ bath technique. The effects of a physiological concentration (0.1 μM) of leptin were also studied on tone and TNS-induced relaxation in the presence of atropine, hexamethonium, L-N(G)-nitroarginine methyl ester (L-NAME) and capsazepine. Leptin caused a slight but significant decrease in tone, TNS-induced relaxation and contraction in a concentration-dependent manner in colonic preparations. Cholinergic antagonists abolished the effects of 0.1 μM leptin on TNS-induced relaxation. This concentration of leptin had no further effect on relaxation in the presence of L-NAME. In the presence of capsazepine, leptin had no further effect either on tone or relaxation compared to the drug alone. In conclusion, leptin modulates the activity of enteric inhibitory and excitatory neurons in proximal colon. These effects may be mediated through nitrergic neurons. Intrinsic primary afferent neurons may be involved.
Collapse
Affiliation(s)
- Voinot Florian
- Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, 23 rue Becquerel, 67087 Strasbourg, France; CNRS, UMR7178, 67037 Strasbourg, France
| | | | | | | | | |
Collapse
|
35
|
Lester S, Stokes L, Skarratt KK, Gu BJ, Sivils KL, Lessard CJ, Wiley JS, Rischmueller M. Epistasis with HLA DR3 implicates the P2X7 receptor in the pathogenesis of primary Sjögren's syndrome. Arthritis Res Ther 2013; 15:R71. [PMID: 23819992 PMCID: PMC3979150 DOI: 10.1186/ar4248] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 05/02/2013] [Accepted: 06/02/2013] [Indexed: 01/05/2023] Open
Abstract
INTRODUCTION The aim of this study was to examine the association between functional polymorphisms in the pro-inflammatory P2X7 receptor and the Ro/La autoantibody response in primary Sjögren's syndrome (pSS). METHODS Twelve functional P2RX7 polymorphisms were genotyped in 114 pSS patients fulfilling the Revised American-European Consensus Criteria for pSS, and 136 controls. Genotyping of the A1405G (rs2230912) polymorphism was performed on a replication cohort consisting of 281 pSS patients and 534 controls. P2X7 receptor function in lymphocytes and monocytes was assessed by measurement of ATP-induced ethidium+ uptake. Serum IL-18 levels were determined by ELISA. RESULTS The minor allele of P2RX7 A1405G is a tag for a common haplotype associated with gain in receptor function, as assessed by ATP-induced ethidium+ uptake. A positive association between 1405G and anti-Ro±La seropositive pSS patients was observed in Cohort 1. Although not replicated in Cohort 2, there was a consistent, significant, negative epistatic interaction effect with HLA-DR3 in seropositive pSS patients from both cohorts, thereby implicating this gain of function variant in the pathogenesis of pSS. Serum IL-18 was elevated in seropositive pSS patients, but was not influenced by P2RX7 A1405G. CONCLUSIONS The P2RX7 1405G gain-of-function haplotype may be a risk factor for seropositive pSS in a subset of subjects who do not carry HLA risk alleles, but has no effect in subjects who do (epistasis). Potential mechanisms relate to autoantigen exposure and inflammatory cytokine expression. The observed elevation of IL-18 levels is consistent with P2X7 receptor activation in seropositive pSS patients. Collectively these findings implicate P2X7 receptor function in the pathogenesis of pSS.
Collapse
Affiliation(s)
- Susan Lester
- Department of Rheumatology, The Queen Elizabeth Hospital, Woodville South, South Australia, Australia
| | - Leanne Stokes
- Sydney Medical School Nepean, University of Sydney, Nepean Hospital, Penrith, NSW, Australia
- Health Innovations Research Institute, School of Medical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Kristen K Skarratt
- Sydney Medical School Nepean, University of Sydney, Nepean Hospital, Penrith, NSW, Australia
| | - Ben J Gu
- Sydney Medical School Nepean, University of Sydney, Nepean Hospital, Penrith, NSW, Australia
- Florey Neuroscience Institutes, University of Melbourne, Parkville, Victoria, Australia
| | - Kathy L Sivils
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Christopher J Lessard
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - James S Wiley
- Sydney Medical School Nepean, University of Sydney, Nepean Hospital, Penrith, NSW, Australia
- Florey Neuroscience Institutes, University of Melbourne, Parkville, Victoria, Australia
| | - Maureen Rischmueller
- Department of Rheumatology, The Queen Elizabeth Hospital, Woodville South, South Australia, Australia
- Discipline of Medicine, University of Adelaide, South Australia, Australia
| |
Collapse
|
36
|
Tu G, Li G, Peng H, Hu J, Liu J, Kong F, Liu S, Gao Y, Xu C, Xu X, Qiu S, Fan B, Zhu Q, Yu S, Zheng C, Wu B, Peng L, Song M, Wu Q, Liang S. P2X(7) inhibition in stellate ganglia prevents the increased sympathoexcitatory reflex via sensory-sympathetic coupling induced by myocardial ischemic injury. Brain Res Bull 2013; 96:71-85. [PMID: 23688519 DOI: 10.1016/j.brainresbull.2013.05.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 05/08/2013] [Accepted: 05/09/2013] [Indexed: 12/11/2022]
Abstract
Purinergic signaling has been found to participate in the regulation of cardiovascular function. In this study, using a rat myocardial ischemic injury model, the sympathoexcitatory reflex mediated by P2X7 receptor via sensory-sympathetic coupling between cervical dorsal root ganglia (DRG) nerves and stellate ganglia (SG) nerves was explored. Our results showed that the systolic blood pressure, heart rate, serum cardiac enzymes concentrations, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) concentrations were increased, and the expression levels of P2X7 mRNA and protein in DRG and SG were up-regulated after myocardial ischemic injury. Administration of brilliant blue G (BBG), a selective P2X7 antagonist, decreased the elevation of systolic blood pressure, heart rate, serum cardiac enzyme, IL-6 and TNF-α, and inhibited the up-regulated expression of P2X7 mRNA and protein in DRG and SG after myocardial ischemic injury. Retrograde tracing test showed that there were calcitonin gene-related peptide sensory nerves and substance P sensory nerves sprouting from DRG to SG, which played an important role in the development of myocardial ischemic injury. The up-regulated P2X7 receptor expression levels on the surface membrane of satellite glial cells contributed to the activation of sensory-sympathetic coupling, which in turn facilitated the sympathoexcitatory reflex. BBG can inhibit the activation of satellite glial cells and interrupt the generation of sensory-sympathetic coupling in the cervical sympathetic ganglia after the myocardial ischemic injury. Taken together, these findings may provide a new therapeutic approach for treating coronary heart disease, hypertension and other cardiovascular diseases.
Collapse
Affiliation(s)
- Guihua Tu
- Department of Physiology, Information Engineering College of Nanchang University, Nanchang, Jiangxi 330006, PR China
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Furuya S, Furuya K. Roles of substance P and ATP in the subepithelial fibroblasts of rat intestinal villi. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 304:133-89. [PMID: 23809436 DOI: 10.1016/b978-0-12-407696-9.00003-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The ingestion of food and water induces chemical and mechanical signals that trigger peristaltic reflexes and also villous movement in the gut. In the intestinal villi, subepithelial fibroblasts under the epithelium form contractile cellular networks and closely contact to the varicosities of substance P and nonsubstance P afferent neurons. Subepithelial fibroblasts of the duodenal villi possess purinergic receptor P2Y1 and tachykinin receptor NK1. ATP and substance P induce increase in intracellular Ca(2+) and cell contraction in subepithelial fibroblasts. They are highly mechanosensitive and release ATP by mechanical stimuli. Released ATP spreads to form an ATP "cloud" with nearly 1μM concentration and activates the surroundings via P2Y1 and afferent neurons via P2X receptors. These findings suggest that villous subepithelial fibroblasts and afferent neurons interact via ATP and substance P. This mutual interaction may play important roles in the signal transduction of mechano reflex pathways including a coordinate villous movement and also in the maturation of the structure and function of the intestinal villi.
Collapse
Affiliation(s)
- Sonoko Furuya
- Section of Brain Structure Information, Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Japan.
| | | |
Collapse
|
38
|
Conde SV, Monteiro EC, Rigual R, Obeso A, Gonzalez C. Hypoxic intensity: a determinant for the contribution of ATP and adenosine to the genesis of carotid body chemosensory activity. J Appl Physiol (1985) 2012; 112:2002-10. [PMID: 22500005 DOI: 10.1152/japplphysiol.01617.2011] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Excitatory effects of adenosine and ATP on carotid body (CB) chemoreception have been previously described. Our hypothesis is that both ATP and adenosine are the key neurotransmitters responsible for the hypoxic chemotransmission in the CB sensory synapse, their relative contribution depending on the intensity of hypoxic challenge. To test this hypothesis we measured carotid sinus nerve (CSN) activity in response to moderate and intense hypoxic stimuli (7 and 0% O(2)) in the absence and in the presence of adenosine and ATP receptor antagonists. Additionally, we quantified the release of adenosine and ATP in normoxia (21% O(2)) and in response to hypoxias of different intensities (10, 5, and 2% O(2)) to study the release pathways. We found that ZM241385, an A(2) antagonist, decreased the CSN discharges evoked by 0 and 7% O(2) by 30.8 and 72.5%, respectively. Suramin, a P(2)X antagonist, decreased the CSN discharges evoked by 0 and 7% O(2) by 64.3 and 17.1%, respectively. Simultaneous application of both antagonists strongly inhibited CSN discharges elicited by both hypoxic intensities. ATP release by CB increased in parallel to hypoxia intensity while adenosine release increased preferably in response to mild hypoxia. We have also found that the lower the O(2) levels are, the higher is the percentage of adenosine produced from extracellular catabolism of ATP. Our results demonstrate that ATP and adenosine are key neurotransmitters involved in hypoxic CB chemotransduction, with a more relevant contribution of adenosine during mild hypoxia, while vesicular ATP release constitutes the preferential origin of extracellular adenosine in high-intensity hypoxia.
Collapse
Affiliation(s)
- S V Conde
- CEDOC, Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.
| | | | | | | | | |
Collapse
|
39
|
Abstract
OBJECTIVES Pulsatile insulin release into the portal vein is critically dependent on entrainment of the islets in the pancreas into a common oscillatory phase. Because the pulses reflect periodic variations of the cytoplasmic Ca concentration ([Ca]i), we studied whether the neurotransmitters adenosine triphosphate (ATP) and acetylcholine promote synchronization of [Ca]i oscillations between islets lacking contact. METHODS Medium-sized and small mouse islets and cell aggregates were used for measuring [Ca]i with the indicator fura-2. RESULTS Exposure to acetylcholine resulted in an initial [Ca]i peak followed by disappearance of the [Ca]i oscillations induced by 11-mmol/L glucose. The effect of ATP was often restricted to an elusive [Ca]i peak. The incidence of distinct [Ca]i responses to ATP increased under conditions (accelerated superfusion, small islets, or cell aggregates) intended to counteract purinoceptor desensitization owing to intercellular accumulation of ATP. Attempts to imitate neural activity by brief (15 seconds) exposure to ATP or acetylcholine resulted in temporary synchronization of the glucose-induced [Ca]i oscillations between islets lacking contact. CONCLUSIONS The data support the idea that purinergic signaling has a key role for coordinating the oscillatory activity of the islets in the pancreas, reinforcing previous arguments for the involvement of nonadrenergic, noncholinergic neurons.
Collapse
|
40
|
Abstract
Central chemoreception traditionally refers to a change in ventilation attributable to changes in CO2/H(+) detected within the brain. Interest in central chemoreception has grown substantially since the previous Handbook of Physiology published in 1986. Initially, central chemoreception was localized to areas on the ventral medullary surface, a hypothesis complemented by the recent identification of neurons with specific phenotypes near one of these areas as putative chemoreceptor cells. However, there is substantial evidence that many sites participate in central chemoreception some located at a distance from the ventral medulla. Functionally, central chemoreception, via the sensing of brain interstitial fluid H(+), serves to detect and integrate information on (i) alveolar ventilation (arterial PCO2), (ii) brain blood flow and metabolism, and (iii) acid-base balance, and, in response, can affect breathing, airway resistance, blood pressure (sympathetic tone), and arousal. In addition, central chemoreception provides a tonic "drive" (source of excitation) at the normal, baseline PCO2 level that maintains a degree of functional connectivity among brainstem respiratory neurons necessary to produce eupneic breathing. Central chemoreception responds to small variations in PCO2 to regulate normal gas exchange and to large changes in PCO2 to minimize acid-base changes. Central chemoreceptor sites vary in function with sex and with development. From an evolutionary perspective, central chemoreception grew out of the demands posed by air versus water breathing, homeothermy, sleep, optimization of the work of breathing with the "ideal" arterial PCO2, and the maintenance of the appropriate pH at 37°C for optimal protein structure and function.
Collapse
Affiliation(s)
- Eugene Nattie
- Dartmouth Medical School, Department of Physiology, Lebanon, New Hampshire, USA.
| | | |
Collapse
|
41
|
Harrison-Woolrych M, Maggo S, Tan M, Savage R, Ashton J. Cardiovascular Events in Patients taking Varenicline. Drug Saf 2012; 35:33-43. [DOI: 10.2165/11597690-000000000-00000] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
|
42
|
Abstract
Central chemoreception traditionally refers to a change in ventilation attributable to changes in CO2/H(+) detected within the brain. Interest in central chemoreception has grown substantially since the previous Handbook of Physiology published in 1986. Initially, central chemoreception was localized to areas on the ventral medullary surface, a hypothesis complemented by the recent identification of neurons with specific phenotypes near one of these areas as putative chemoreceptor cells. However, there is substantial evidence that many sites participate in central chemoreception some located at a distance from the ventral medulla. Functionally, central chemoreception, via the sensing of brain interstitial fluid H(+), serves to detect and integrate information on (i) alveolar ventilation (arterial PCO2), (ii) brain blood flow and metabolism, and (iii) acid-base balance, and, in response, can affect breathing, airway resistance, blood pressure (sympathetic tone), and arousal. In addition, central chemoreception provides a tonic "drive" (source of excitation) at the normal, baseline PCO2 level that maintains a degree of functional connectivity among brainstem respiratory neurons necessary to produce eupneic breathing. Central chemoreception responds to small variations in PCO2 to regulate normal gas exchange and to large changes in PCO2 to minimize acid-base changes. Central chemoreceptor sites vary in function with sex and with development. From an evolutionary perspective, central chemoreception grew out of the demands posed by air versus water breathing, homeothermy, sleep, optimization of the work of breathing with the "ideal" arterial PCO2, and the maintenance of the appropriate pH at 37°C for optimal protein structure and function.
Collapse
Affiliation(s)
- Eugene Nattie
- Dartmouth Medical School, Department of Physiology, Lebanon, New Hampshire, USA.
| | | |
Collapse
|
43
|
Beyder A, Farrugia G. Targeting ion channels for the treatment of gastrointestinal motility disorders. Therap Adv Gastroenterol 2012; 5:5-21. [PMID: 22282704 PMCID: PMC3263980 DOI: 10.1177/1756283x11415892] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Gastrointestinal (GI) functional and motility disorders are highly prevalent and responsible for long-term morbidity and sometimes mortality in the affected patients. It is estimated that one in three persons has a GI functional or motility disorder. However, diagnosis and treatment of these widespread conditions remains challenging. This partly stems from the multisystem pathophysiology, including processing abnormalities in the central and peripheral (enteric) nervous systems and motor dysfunction in the GI wall. Interstitial cells of Cajal (ICCs) are central to the generation and propagation of the cyclical electrical activity and smooth muscle cells (SMCs) are responsible for electromechanical coupling. In these and other excitable cells voltage-sensitive ion channels (VSICs) are the main molecular units that generate and regulate electrical activity. Thus, VSICs are potential targets for intervention in GI motility disorders. Research in this area has flourished with advances in the experimental methods in molecular and structural biology and electrophysiology. However, our understanding of the molecular mechanisms responsible for the complex and variable electrical behavior of ICCs and SMCs remains incomplete. In this review, we focus on the slow waves and action potentials in ICCs and SMCs. We describe the constituent VSICs, which include voltage-gated sodium (Na(V)), calcium (Ca(V)), potassium (K(V), K(Ca)), chloride (Cl(-)) and nonselective ion channels (transient receptor potentials [TRPs]). VSICs have significant structural homology and common functional mechanisms. We outline the approaches and limitations and provide examples of targeting VSICs at the pores, voltage sensors and alternatively spliced sites. Rational drug design can come from an integrated view of the structure and mechanisms of gating and activation by voltage or mechanical stress.
Collapse
Affiliation(s)
- Arthur Beyder
- Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN, USA
| | | |
Collapse
|
44
|
Ohtomo K, Shatos MA, Vrouvlianis J, Li D, Hodges RR, Dartt DA. Increase of intracellular Ca2+ by purinergic receptors in cultured rat lacrimal gland myoepithelial cells. Invest Ophthalmol Vis Sci 2011; 52:9503-15. [PMID: 22039237 DOI: 10.1167/iovs.11-7809] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
PURPOSE To isolate and characterize cultured myoepithelial cells (MECs) from rat lacrimal gland and determine which purinergic receptor subtypes are present and functional in MECs. METHODS Rat lacrimal glands were subjected to collagenase digestion, and MECs were grown. RT-PCR was performed for the purinergic receptors P2X(7), P2Y(1), P2Y(11), and P2Y(13) on RNA isolated from the MECs. Immunofluorescence experiments were performed with antibodies against MEC markers and P2X(7), P2Y(1), P2Y(11), and P2Y(13) purinergic receptors. Proteins from MECs were separated using Western blot analysis techniques. In addition, cells were incubated with Fura 2 tetra acetoxymethyl ester, and intracellular [Ca(2+)] ([Ca(2+)](i)) was determined in response to P2 purinergic agonists. RESULTS MECs expressed the MEC proteins α-smooth muscle actin, vimentin, α-actinin, and adenylyl cyclase II. RT-PCR, Western blot, and immunofluorescence techniques demonstrated the presence of the purinergic receptors P2X(7), P2Y(1), P2Y(11), and P2Y(13). The purinergic agonists ATP, benzoylbenzoyl ATP (BzATP), α,β methylene ATP, UTP, 2-methylthioATP (MeSATP), and ATPγS increased [Ca(2+)](i). As BzATP binds to the P2X(7) receptor, specific characteristics of this receptor were investigated. Neither inhibitors of P2X(7) receptors nor removal of extracellular Mg(2+) or Ca(2+) had an effect on the BzATP-stimulated increase in [Ca(2+)](i). Repeated applications of BzATP desensitized this response. Inhibitors for P2Y(1), P2Y(11), and P2Y(13) each decreased the BzATP-stimulated increase in [Ca(2+)](i) with the P2Y(1) inhibitor most effective. CONCLUSIONS MECs can be isolated from rat lacrimal glands, and they express P2X(7), P2Y(1), P2Y(11), and P2Y(13) purinergic receptors. Surprisingly, BzATP binds the P2Y(1) receptor, which is primarily responsible for the BzATP-stimulated increase in [Ca(2+)](i).
Collapse
Affiliation(s)
- Kaori Ohtomo
- Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | | | | | | | | | | |
Collapse
|
45
|
Long-term (trophic) purinergic signalling: purinoceptors control cell proliferation, differentiation and death. Cell Death Dis 2011; 1:e9. [PMID: 21364628 PMCID: PMC3032501 DOI: 10.1038/cddis.2009.11] [Citation(s) in RCA: 157] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The purinergic signalling system, which uses purines and pyrimidines as chemical transmitters, and purinoceptors as effectors, is deeply rooted in evolution and development and is a pivotal factor in cell communication. The ATP and its derivatives function as a 'danger signal' in the most primitive forms of life. Purinoceptors are extraordinarily widely distributed in all cell types and tissues and they are involved in the regulation of an even more extraordinary number of biological processes. In addition to fast purinergic signalling in neurotransmission, neuromodulation and secretion, there is long-term (trophic) purinergic signalling involving cell proliferation, differentiation, motility and death in the development and regeneration of most systems of the body. In this article, we focus on the latter in the immune/defence system, in stratified epithelia in visceral organs and skin, embryological development, bone formation and resorption, as well as in cancer.
Collapse
|
46
|
Hodges RR, Vrouvlianis J, Scott R, Dartt DA. Identification of P2X₃ and P2X₇ purinergic receptors activated by ATP in rat lacrimal gland. Invest Ophthalmol Vis Sci 2011; 52:3254-63. [PMID: 21421865 DOI: 10.1167/iovs.10-7042] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
PURPOSE. To identify the type of purinergic receptors activated by adenosine triphosphate (ATP) in rat lacrimal gland and to determine their role in protein secretion. METHODS. Purinergic receptors were identified by RT-PCR, Western blot analysis, and immunofluorescence techniques. Acini from rat lacrimal gland were isolated by collagenase digestion. Acini were incubated with the fluorescence indicator fura-2 tetra-acetoxylmethyl ester, and intracellular [Ca(2+)] ([Ca(2+)](i)) was determined. Protein secretion was measured by fluorescence assay. RESULTS. The authors previously showed that P2X(7)receptors were functional in the lacrimal gland. In this study, they show that P2X(1-4) and P2X(6)receptors were identified in the lacrimal gland by RT-PCR, Western blot, and immunofluorescence analyses. P2X(5) receptors were not detected. ATP increased [Ca(2+)](i) and protein secretion in a concentration-dependent manner. Removal of extracellular Ca(2+) significantly reduced the ATP-stimulated increase in [Ca(2+)](i). Repeated applications of ATP caused desensitization of the [Ca(2+)](i) response. Incubation with the P2X(1) receptor inhibitor NF023 did not alter ATP-stimulated [Ca(2+)](i). Incubation with zinc, which potentiates P2X(2) and P2X(4) receptor responses, or lowering the pH to 6.8, which potentiates P2X(2) receptor responses, did not alter the ATP-stimulated [Ca(2+)](i). P2X(3) receptor inhibitors A-317491 and TNP-ATP significantly decreased ATP-stimulated [Ca(2+)](i) and protein secretion, whereas the P2X(3) receptor agonist α,β methylene ATP significantly increased them. The P2X(7) receptor inhibitor A438079 had no effect on ATP-stimulated [Ca(2+)](i) at 10(-6) M but did have an effect at 10(-4) M. CONCLUSIONS. Purinergic receptors P2X(1-4) and P2X(6) are present in the lacrimal gland. ATP uses P2X(3) and P2X(7) receptors to stimulate an increase in [Ca(2+)](i) and protein secretion.
Collapse
Affiliation(s)
- Robin R Hodges
- Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114, USA.
| | | | | | | |
Collapse
|
47
|
Nattie E. Julius H. Comroe, Jr., distinguished lecture: central chemoreception: then ... and now. J Appl Physiol (1985) 2011; 110:1-8. [PMID: 21071595 PMCID: PMC3252999 DOI: 10.1152/japplphysiol.01061.2010] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 11/05/2010] [Indexed: 12/19/2022] Open
Abstract
The 2010 Julius H. Comroe, Jr., Lecture of the American Physiological Society focuses on evolving ideas in chemoreception for CO₂/pH in terms of what is "sensed," where it is sensed, and how the sensed information is used physiologically. Chemoreception is viewed as involving neurons (and glia) at many sites within the hindbrain, including, but not limited to, the retrotrapezoid nucleus, the medullary raphe, the locus ceruleus, the nucleus tractus solitarius, the lateral hypothalamus (orexin neurons), and the caudal ventrolateral medulla. Central chemoreception also has an important nonadditive interaction with afferent information arising at the carotid body. While ventilation has been viewed as the primary output variable, it appears that airway resistance, arousal, and blood pressure can also be significantly affected. Emphasis is placed on the importance of data derived from studies performed in the absence of anesthesia.
Collapse
Affiliation(s)
- Eugene Nattie
- Department of Physiology, Dartmouth Medical School, Lebanon New Hampshire 03756-0001, USA.
| |
Collapse
|
48
|
Passamani LM, Pedrosa DF, Mauad H, Schenberg LC, Paton JFR, Sampaio KN. Involvement of the purinergic system in central cardiovascular modulation at the level of the nucleus ambiguus of anaesthetized rats. Exp Physiol 2010; 96:262-74. [PMID: 21148626 DOI: 10.1113/expphysiol.2010.054882] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Anatomical studies have demonstrated the existence of purinergic P2 receptors in the nucleus ambiguus (NA), a site containing cardiac vagal motoneurons. However, very little is known about the functional role of these receptors in central cardiac vagal regulation. The aims of our study were to evaluate the following: (1) the blood pressure and heart rate responses following purinoceptor activation within the NA; (2) the role of purinoceptors and excitatory amino acid (EAA) receptors in mediating the cardiovascular responses evoked by ATP and L-glutamate stimulation of NA; and (3) the role of NA purinoceptors in mediating the cardiovascular responses of the Bezold-Jarisch reflex. In anaesthetized rats, microinjection of L-glutamate (5.0 nmol/50 nl) into the NA induced a marked and immediate onset bradycardia with minimal change in arterial pressure. Microinjection of ATP into the NA induced a dose-dependent (0.31-6.0 nmol/50 nl) bradycardia and pressor responses. It is noteworthy that the bradycardia occurred either before or simultaneously with a pressor response (when present), indicating that it was not a baroreceptor reflex mediated response due to the rise in arterial pressure. The pressor response was prevented by α(1)-adrenergic blockade with prazosin, whereas muscarinic blockade with methyl-atropine abolished the evoked bradycardia. Ipsilateral microinjection of PPADS (a P2 receptor antagonist; 500 pmol/100 nl) into the NA significantly attenuated the ATP-induced bradycardia but spared the pressor response. In contrast, PPADS in the NA had no effect on the L-glutamate-evoked bradycardic response. Ipsilateral injection of kynurenic acid (a non-selective EAA receptor antagonist; 10 nmol/50 nl) into the NA totally blocked the bradycardia induced by l-glutamate and partly attenuated the ATP induced bradycardia. Finally, both the depressor and the bradycardic responses of the Bezold-Jarisch reflex were attenuated significantly (P < 0.01 and P < 0.05, respectively) following bilateral microinjection of PPADS into the NA. These results identify ATP and purinergic P2 receptors within the ventrolateral medulla as excitatory to cardiovagal neurons. Additionally, our data show that P2 receptors within the ventrolateral medulla are integral to the cardiovascular responses of the Bezold-Jarisch reflex.
Collapse
Affiliation(s)
- Luciana M Passamani
- Physiological Sciences, Health Sciences Center, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
| | | | | | | | | | | |
Collapse
|
49
|
McClure JM, O'Leary DS, Scislo TJ. Neural and humoral control of regional vascular beds via A1 adenosine receptors located in the nucleus tractus solitarii. Am J Physiol Regul Integr Comp Physiol 2010; 300:R744-55. [PMID: 21148476 DOI: 10.1152/ajpregu.00565.2010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Our previous studies showed that stimulation of adenosine A(1) receptors located in the nucleus of the solitary tract (NTS) exerts counteracting effects on the iliac vascular bed: activation of the adrenal medulla and β-adrenergic vasodilation vs. sympathetic and vasopressinergic vasoconstriction. Because NTS A(1) adenosine receptors inhibit baroreflex transmission in the NTS and contribute to the pressor component of the HDR, we hypothesized that these receptors also contribute to the redistribution of blood from the visceral to the muscle vasculature via prevailing sympathetic and vasopressinergic vasoconstriction in the visceral (renal and mesenteric) vascular beds and prevailing β-adrenergic vasodilation in the somatic (iliac) vasculature. To test this hypothesis, we compared the A(1) adenosine-receptor-mediated effects of each vasoactive factor triggered by NTS A(1) adenosine receptor stimulation [N(6)-cyclopentyladenosine (CPA), 330 pmol in 50 nl] on the regional vascular responses in urethane/chloralose-anesthetized rats. The single-factor effects were separated using adrenalectomy, β-adrenergic blockade, V(1) vasopressin receptor blockade, and sinoaortic denervation. In intact animals, initial vasodilation was followed by large, sustained vasoconstriction with smaller responses observed in renal vs. mesenteric and iliac vascular beds. The initial β-adrenergic vasodilation prevailed in the iliac vs. mesenteric and renal vasculature. The large and sustained vasopressinergic vasoconstriction was similar in all vascular beds. Small sympathetic vasoconstriction was observed only in the iliac vasculature in this setting. We conclude that, although A(1) adenosine-receptor-mediated β-adrenergic vasodilation may contribute to the redistribution of blood from the visceral to the muscle vasculature, this effect is overridden by sympathetic and vasopressinergic vasoconstriction.
Collapse
Affiliation(s)
- Joseph M McClure
- Dept. of Physiology, Wayne State Univ. School of Medicine, Detroit, MI 48201, USA
| | | | | |
Collapse
|
50
|
Niane LM, Donnelly DF, Joseph V, Bairam A. Ventilatory and carotid body chemoreceptor responses to purinergic P2X receptor antagonists in newborn rats. J Appl Physiol (1985) 2010; 110:83-94. [PMID: 21051571 DOI: 10.1152/japplphysiol.00871.2010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adenosine triphosphate, acting through purinergic P2X receptors, has been shown to stimulate ventilation and increase carotid body chemoreceptor activity in adult rats. However, its role during postnatal development of the ventilatory response to hypoxia is yet unknown. Using whole body plethysmography, we measured ventilation in normoxia and in moderate hypoxia (12% fraction of inspired O₂, 20 min) before and after intraperitoneal injection of suramin (P2X₂ and P2X₃ receptor antagonist, 40 mg/kg) in 4-, 7-, 12-, and 21-day-old rats. Suramin reduced baseline breathing (∼20%) and the response to hypoxia (∼30%) in all rats, with a relatively constant effect across ages. We then tested the effect of the specific P2X₃ antagonist, A-317491 (150 mg/kg), in rats aged 4, 7, and 21 days. As with suramin, A-317491 reduced baseline ventilation (∼55%) and the hypoxic response (∼40%) at all ages studied. Single-unit carotid body chemoreceptor activity was recorded in vitro in 4-, 7-, and 21-day-old rats. Suramin (100 μM) and A-317491 (10 μM) significantly depressed the sinus nerve chemosensory discharge rate (∼80%) in normoxia (Po₂ ∼150 Torr) and hypoxia (Po₂ ∼60 Torr), and this decrease was constant across ages. We conclude that, in newborn rats, P2X purinergic receptors are involved in the regulation of breathing under basal and hypoxic condition, and P2X₃-containing receptors play a major role in carotid body function. However, these effects are not age dependent within the age range studied.
Collapse
Affiliation(s)
- Lalah M Niane
- Unité de Recherche en Périnatologie, Centre Hospitalier Universitaire de Québec, Hôpital Saint-François d’Assise, Département de Pédiatrie, Université Laval, Québec, Canada
| | | | | | | |
Collapse
|