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Walewska A, Szewczyk A, Krajewska M, Koprowski P. Targeting mitochondrial large-conductance calcium-activated potassium channel by hydrogen sulfide via heme-binding site. J Pharmacol Exp Ther 2022; 381:137-150. [DOI: 10.1124/jpet.121.001017] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/10/2022] [Indexed: 11/22/2022] Open
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Li D, Liu H, Wang H, Jia S, Wang X, Ling S, Chen G, Liu X, Wang YF. Astrocytic Hydrogen Sulfide Regulates Supraoptic Cellular Activity in the Adaptive Response of Lactating Rats to Chronic Social Stress. ASN Neuro 2021; 13:17590914211043087. [PMID: 34579557 PMCID: PMC8642056 DOI: 10.1177/17590914211043087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Maternal social stress among breastfeeding women can be adapted in chronic process.
However, neuroendocrine mechanisms underlying such adaptation remain to be identified.
Here, we report the effects of 2 hr/day unfamiliar male rat invasion (UMI) stress on
maternal behaviors in lactating rats during postpartum day 8 (UMI8) to postpartum day 12
(UMI12). Rat dams at UMI8 presented signs of maternal anxiety, depression, and attacks
toward male intruder. These changes partially reversed at UMI12 except the sign of
anxiety. In the supraoptic nucleus (SON), UMI12 but not UMI8 significantly increased the
expression of c-Fos and phosphorylated extracellular signal-regulated protein kinase 1/2.
At UMI8 but not UMI12, length of glial fibrillary acidic protein (GFAP, astrocytic
cytoskeletal element) filaments around oxytocin (OT) neurons was significantly longer than
that of their controls; the amount of GFAP fragments at UMI12 was significantly less than
that at UMI8. Expression of cystathionine β-synthase (CBS, enzyme for H2S
synthesis) at UMI12 was significantly higher than that at UMI8. CBS expression did not
change significantly in the somatic zone of the SON but decreased significantly at the
ventral glia lamina at UMI8. In brain slices of the SON, aminooxyacetate (a CBS blocker)
significantly increased the expression of GFAP proteins that were molecularly associated
with CBS. Aminooxyacetate also reduced the firing rate of OT neurons whereas
Na2S, a donor of H2S, increased it. The adaptation during chronic
social stress is possibly attributable to the increased production of H2S by
astrocytes and the subsequent retraction of astrocytic processes around OT neurons.
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Affiliation(s)
- Dongyang Li
- Department of Physiology, 12455Hainan Medical University, Haikou, China.,Department of Physiology, School of Basic Medical Sciences, 34707Harbin Medical University, Harbin, China
| | - Haitao Liu
- Department of Physiology, School of Basic Medical Sciences, 34707Harbin Medical University, Harbin, China
| | - Hongyang Wang
- Department of Physiology, School of Basic Medical Sciences, 34707Harbin Medical University, Harbin, China
| | - Shuwei Jia
- Department of Physiology, School of Basic Medical Sciences, 34707Harbin Medical University, Harbin, China
| | - Xiaoran Wang
- Department of Physiology, School of Basic Medical Sciences, 34707Harbin Medical University, Harbin, China
| | - Shuo Ling
- Department of Physiology, School of Basic Medical Sciences, 34707Harbin Medical University, Harbin, China
| | - Guichuan Chen
- Department of Physiology, School of Basic Medical Sciences, 34707Harbin Medical University, Harbin, China
| | - Xiaoyu Liu
- Department of Physiology, School of Basic Medical Sciences, 34707Harbin Medical University, Harbin, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, 34707Harbin Medical University, Harbin, China
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Danger perception and stress response through an olfactory sensor for the bacterial metabolite hydrogen sulfide. Neuron 2021; 109:2469-2484.e7. [PMID: 34186026 DOI: 10.1016/j.neuron.2021.05.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/01/2021] [Accepted: 05/27/2021] [Indexed: 12/11/2022]
Abstract
The olfactory system serves a critical function as a danger detection system to trigger defense responses essential for survival. The cellular and molecular mechanisms that drive such defenses in mammals are incompletely understood. Here, we have discovered an ultrasensitive olfactory sensor for the highly poisonous bacterial metabolite hydrogen sulfide (H2S) in mice. An atypical class of sensory neurons in the main olfactory epithelium, the type B cells, is activated by both H2S and low O2. These two stimuli trigger, respectively, Cnga2- and Trpc2-signaling pathways, which operate in separate subcellular compartments, the cilia and the dendritic knob. This activation drives essential defensive responses: elevation of the stress hormone ACTH, stress-related self-grooming behavior, and conditioned place avoidance. Our findings identify a previously unknown signaling paradigm in mammalian olfaction and define type B cells as chemosensory neurons that integrate distinct danger inputs from the external environment with appropriate defense outputs.
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Medlock L, Shute L, Fry M, Standage D, Ferguson AV. Ionic mechanisms underlying tonic and burst firing behavior in subfornical organ neurons: a combined experimental and modeling study. J Neurophysiol 2018; 120:2269-2281. [PMID: 30089060 DOI: 10.1152/jn.00340.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Subfornical organ (SFO) neurons exhibit heterogeneity in current expression and spiking behavior, where the two major spiking phenotypes appear as tonic and burst firing. Insight into the mechanisms behind this heterogeneity is critical for understanding how the SFO, a sensory circumventricular organ, integrates and selectively influences physiological function. To integrate efficient methods for studying this heterogeneity, we built a single-compartment, Hodgkin-Huxley-type model of an SFO neuron that is parameterized by SFO-specific in vitro patch-clamp data. The model accounts for the membrane potential distribution and spike train variability of both tonic and burst firing SFO neurons. Analysis of model dynamics confirms that a persistent Na+ and Ca2+ currents are required for burst initiation and maintenance and suggests that a slow-activating K+ current may be responsible for burst termination in SFO neurons. Additionally, the model suggests that heterogeneity in current expression and subsequent influence on spike afterpotential underlie the behavioral differences between tonic and burst firing SFO neurons. Future use of this model in coordination with single neuron patch-clamp electrophysiology provides a platform for explaining and predicting the response of SFO neurons to various combinations of circulating signals, thus elucidating the mechanisms underlying physiological signal integration within the SFO. NEW & NOTEWORTHY Our understanding of how the subfornical organ (SFO) selectively influences autonomic nervous system function remains incomplete but theoretically results from the electrical responses of SFO neurons to physiologically important signals. We have built a computational model of SFO neurons, derived from and supported by experimental data, which explains how SFO neurons produce different electrical patterns. The model provides an efficient system to theoretically and experimentally explore how changes in the essential features of SFO neurons affect their electrical activity.
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Affiliation(s)
- Laura Medlock
- Center for Neuroscience Studies, Queen's University , Kingston, Ontario , Canada
| | - Lauren Shute
- Department of Biological Sciences, University of Manitoba , Winnipeg, Manitoba , Canada
| | - Mark Fry
- Department of Biological Sciences, University of Manitoba , Winnipeg, Manitoba , Canada
| | - Dominic Standage
- Center for Neuroscience Studies, Queen's University , Kingston, Ontario , Canada
| | - Alastair V Ferguson
- Center for Neuroscience Studies, Queen's University , Kingston, Ontario , Canada
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Kamesh A, Black EAE, Ferguson AV. The subfornical organ: A novel site for prolactin action. J Neuroendocrinol 2018; 30:e12613. [PMID: 29862587 DOI: 10.1111/jne.12613] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 05/27/2018] [Accepted: 05/31/2018] [Indexed: 12/30/2022]
Abstract
Prolactin (PRL) is a peptide hormone that performs over 300 biological functions, including those that require binding to prolactin receptor (PRL-R) in neurones within the central nervous system (CNS). To enter the CNS, circulating PRL must overcome the blood-brain barrier. Accordingly, areas of the brain that do not possess a blood-brain barrier, such as the subfornical organ (SFO), are optimally positioned to interact with systemic PRL. The SFO has been classically implicated in energy and fluid homeostasis but has the potential to influence oestrous cyclicity and gonadotrophin release, which are also functions of PRL. We aimed to confirm and characterise the expression of PRL-R in the SFO, as well as identify the effects of PRL application on membrane excitability of dissociated SFO neurones. Using a quantitative real-time polymerase chain reaction, we found that PRL-R mRNA in the SFO of male and female Sprague Dawley rats did not significantly differ between juvenile and sexually mature rats (P = .34), male and female rats (P = .97) or across the oestrous cycle (P = .54). Patch-clamp recordings were obtained in juvenile male rats to further investigate the actions of PRL at the SFO. Dissociated SFO neurones perfused with 1 μmol L-1 PRL resulted in 2 responsive subpopulations of neurones; 40% depolarised (n = 15/43, 11.3 ± 1.7 mV) and 14% hyperpolarised (n = 6/43, -6.7 ± 1.4 mV) to PRL application. Within the range of 10 pmol L-1 to 1 μmol L-1 , the concentrations of PRL were not significantly different in either the magnitude (P = .53) or proportion (P = .19) of response. Furthermore, PRL application significantly reduced the transient K+ current in 67% of SFO neurones in voltage-clamp configuration (n = 6/9, P = .02). The stability in response to PRL and expression of PRL-R in the SFO suggests that PRL function is conserved across physiological states and circulating PRL concentrations, prompting further investigations aiming to clarify the nature of PRL function in the SFO.
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Affiliation(s)
- A Kamesh
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
| | - E A E Black
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - A V Ferguson
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
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6
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Hydrogen sulphide facilitates exocytosis by regulating the handling of intracellular calcium by chromaffin cells. Pflugers Arch 2018; 470:1255-1270. [DOI: 10.1007/s00424-018-2147-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 04/10/2018] [Accepted: 04/17/2018] [Indexed: 01/09/2023]
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Ha J, Xu Y, Kawano T, Hendon T, Baki L, Garai S, Papapetropoulos A, Thakur GA, Plant LD, Logothetis DE. Hydrogen sulfide inhibits Kir2 and Kir3 channels by decreasing sensitivity to the phospholipid phosphatidylinositol 4,5-bisphosphate (PIP 2). J Biol Chem 2018; 293:3546-3561. [PMID: 29317494 DOI: 10.1074/jbc.ra117.001679] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 01/07/2018] [Indexed: 11/06/2022] Open
Abstract
Inwardly rectifying potassium (Kir) channels establish and regulate the resting membrane potential of excitable cells in the heart, brain, and other peripheral tissues. Phosphatidylinositol 4,5-bisphosphate (PIP2) is a key direct activator of ion channels, including Kir channels. The gasotransmitter carbon monoxide has been shown to regulate Kir channel activity by altering channel-PIP2 interactions. Here, we tested in two cellular models the effects and mechanism of action of another gasotransmitter, hydrogen sulfide (H2S), thought to play a key role in cellular responses under ischemic conditions. Direct administration of sodium hydrogen sulfide as an exogenous H2S source and expression of cystathionine γ-lyase, a key enzyme that produces endogenous H2S in specific brain tissues, resulted in comparable current inhibition of several Kir2 and Kir3 channels. This effect resulted from changes in channel-gating kinetics rather than in conductance or cell-surface localization. The extent of H2S regulation depended on the strength of the channel-PIP2 interactions. H2S regulation was attenuated when channel-PIP2 interactions were strengthened and was increased when channel-PIP2 interactions were weakened by depleting PIP2 levels. These H2S effects required specific cytoplasmic cysteine residues in Kir3.2 channels. Mutation of these residues abolished H2S inhibition, and reintroduction of specific cysteine residues back into the background of the cytoplasmic cysteine-lacking mutant rescued H2S inhibition. Molecular dynamics simulation experiments provided mechanistic insights into how potential sulfhydration of specific cysteine residues could lead to changes in channel-PIP2 interactions and channel gating.
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Affiliation(s)
- Junghoon Ha
- From the Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298
| | - Yu Xu
- Department of Pharmaceutical Sciences in the School of Pharmacy, Northeastern University Bouvé College of Health Sciences, Boston, Massachusetts 02115
| | - Takeharu Kawano
- Department of Pharmaceutical Sciences in the School of Pharmacy, Northeastern University Bouvé College of Health Sciences, Boston, Massachusetts 02115
| | - Tyler Hendon
- From the Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298
| | - Lia Baki
- Department of Pharmaceutical Sciences in the School of Pharmacy, Northeastern University Bouvé College of Health Sciences, Boston, Massachusetts 02115
| | - Sumanta Garai
- Department of Pharmaceutical Sciences in the School of Pharmacy, Northeastern University Bouvé College of Health Sciences, Boston, Massachusetts 02115
| | - Andreas Papapetropoulos
- the Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens 157 71, Greece, and.,the Center of Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, Athens 11527, Greece
| | - Ganesh A Thakur
- Department of Pharmaceutical Sciences in the School of Pharmacy, Northeastern University Bouvé College of Health Sciences, Boston, Massachusetts 02115
| | - Leigh D Plant
- Department of Pharmaceutical Sciences in the School of Pharmacy, Northeastern University Bouvé College of Health Sciences, Boston, Massachusetts 02115
| | - Diomedes E Logothetis
- From the Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298, .,Department of Pharmaceutical Sciences in the School of Pharmacy, Northeastern University Bouvé College of Health Sciences, Boston, Massachusetts 02115
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Yakovlev AV, Kurmasheva ED, Ishchenko Y, Giniatullin R, Sitdikova GF. Age-Dependent, Subunit Specific Action of Hydrogen Sulfide on GluN1/2A and GluN1/2B NMDA Receptors. Front Cell Neurosci 2017; 11:375. [PMID: 29225568 PMCID: PMC5705612 DOI: 10.3389/fncel.2017.00375] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 11/10/2017] [Indexed: 11/13/2022] Open
Abstract
Hydrogen sulfide (H2S) is an endogenously produced neuroactive gas implicated in many key processes in the peripheral and central nervous system. Whereas the neuroprotective role of H2S has been shown in adult brain, the action of this messenger in newborns remains unclear. One of the known targets of H2S in the nervous system is the N-methyl-D-aspartate (NMDA) glutamate receptor which can be composed of different subunits with distinct functional properties. In the present study, using patch clamp technique, we compared the effects of the H2S donor sodium hydrosulfide (NaHS, 100 μM) on hippocampal NMDA receptor mediated currents in rats of the first and third postnatal weeks. This was supplemented by testing effects of NaHS on recombinant GluN1/2A and GluN1/2B NMDA receptors expressed in HEK293T cells. The main finding is that NaHS action on NMDA currents is age-dependent. Currents were reduced in newborns but increased in older juvenile rats. Consistent with an age-dependent switch in NMDA receptor composition, in HEK239T cells expressing GluN1/2A receptors, NaHS increased NMDA activated currents associated with acceleration of desensitization and decrease of the deactivation rate. In contrast, in GluN1/2B NMDA receptors, which are prevalent in newborns, NaHS decreased currents and reduced receptor deactivation without effect on the desensitization rate. Adenylate cyclase inhibitor MDL-12330A (10 μM) did not prevent the age-dependent effects of NaHS on NMDA evoked currents in pyramidal neurons of hippocampus. The reducing agent dithiothreitol (DTT, 2 mM) applied on HEK293T cells prevented facilitation induced by NaHS on GluN1/2A NMDA receptors, however in GluN1/2B NMDA receptors the inhibitory effect of NaHS was still observed. Our data indicate age-dependent effect of H2S on NMDA receptor mediated currents determined by glutamate receptor subunit composition. While the inhibitory action of H2 on GluN1/2B receptors could limit the excessive activation in early age, the enhanced functionality of GluN1/2A receptor in the presence of this gasotransmitter can enlarge synaptic efficacy and promote synaptic plasticity in adults.
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Affiliation(s)
- Aleksey V Yakovlev
- Department of Human and Animal Physiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Evgeniya D Kurmasheva
- Department of Human and Animal Physiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Yevheniia Ishchenko
- Laboratory of Molecular Pain Research, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Rashid Giniatullin
- Laboratory of Molecular Pain Research, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.,Laboratory of Neurobiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Guzel F Sitdikova
- Department of Human and Animal Physiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
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Teicher C, De Col R, Messlinger K. Hydrogen Sulfide Mediating both Excitatory and Inhibitory Effects in a Rat Model of Meningeal Nociception and Headache Generation. Front Neurol 2017; 8:336. [PMID: 28769868 PMCID: PMC5509793 DOI: 10.3389/fneur.2017.00336] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 06/27/2017] [Indexed: 01/18/2023] Open
Abstract
Background/purpose Hydrogen sulfide (H2S) is a neuromodulator acting through nitroxyl (HNO) when it reacts with nitric oxide (NO). HNO activates transient receptor potential channels of the ankyrin type 1 (TRPA1) causing release of calcitonin gene-related peptide from primary afferents. Activation of meningeal nociceptors projecting to the human spinal trigeminal nucleus (STN) may lead to headaches. In a rat model of meningeal nociception, the activity of spinal trigeminal neurons was used as read-out for the interaction between H2S and NO. Methods In anesthetized rats extracellular recordings from single neurons in the STN were made. Sodium sulfide (Na2S) producing H2S in the tissue and the NO donor diethylamine-NONOate (DEA-NONOate) were infused intravenously. H2S was also locally applied onto the exposed cranial dura mater or the medulla. Endogenous production of H2S was inhibited by oxamic acid, and NO production was inhibited by nitro-l-arginine methyl ester hydrochloride (l-NAME) to manipulate endogenous HNO formation. Key results Systemic administration of Na2S was followed either by increased ongoing activity (in 73%) or decreased activity (in 27% of units). Topical application of Na2S onto the cranial dura mater caused a short-lasting activation followed by a long-lasting decrease in activity in the majority of units (70%). Systemic administration of DEA-NONOate increased neuronal activity, subsequent infusion of Na2S added to this effect, whereas DEA-NONOate did not augment the activity after Na2S. The stimulating effect of DEA-NONOate was inhibited by oxamic acid in 75% of units, and l-NAME following Na2S administration returned the activity to baseline. Conclusion Individual spinal trigeminal neurons may be activated or (less frequently) inhibited by the TRPA1 agonist HNO, presumably formed by H2S and NO in the STN, whereby endogenous H2S production seems to be rate-limiting. Activation of meningeal afferents by HNO may induce decreased spinal trigeminal activity, consistent with the elevation of the electrical threshold caused by TRPA1 activation in afferent fibers. Thus, the effects of H2S–NO–TRPA1 signaling depend on the site of action and the type of central neurons. The role of H2S–NO–TRPA1 in headache generation seems to be ambiguous.
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Affiliation(s)
- Christiane Teicher
- Institute of Physiology and Pathophysiology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Roberto De Col
- Institute of Physiology and Pathophysiology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Karl Messlinger
- Institute of Physiology and Pathophysiology, University of Erlangen-Nürnberg, Erlangen, Germany
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10
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Simpson NJ, Ferguson AV. The proinflammatory cytokine tumor necrosis factor-α excites subfornical organ neurons. J Neurophysiol 2017. [PMID: 28637815 DOI: 10.1152/jn.00238.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Tumor necrosis factor-α (TNF-α) is a proinflammatory cytokine implicated in cardiovascular and autonomic regulation via actions in the central nervous system. TNF-α-/- mice do not develop angiotensin II (ANG II)-induced hypertension, and administration of TNF-α into the bloodstream of rats increases blood pressure and sympathetic tone. Recent studies have shown that lesion of the subfornical organ (SFO) attenuates the hypertensive and autonomic effects of TNF-α, while direct administration of TNF-α into the SFO increases blood pressure, suggesting the SFO to be a key site for the actions of TNF-α. Therefore, we used patch-clamp techniques to examine both acute and long-term effects of TNF-α on the excitability of Sprague-Dawley rat SFO neurons. It was observed that acute bath application of TNF-α depolarized SFO neurons and subsequently increased action potential firing rate. Furthermore, the magnitude of depolarization and the proportion of depolarized SFO neurons were concentration dependent. Interestingly, following 24-h incubation with TNF-α, the basal firing rate of the SFO neurons was increased and the rheobase was decreased, suggesting that TNF-α elevates SFO neuron excitability. This effect was likely mediated by the transient sodium current, as TNF-α increased the magnitude of the current and lowered its threshold of activation. In contrast, TNF-α did not appear to modulate either the delayed rectifier potassium current or the transient potassium current. These data suggest that acute and long-term TNF-α exposure elevates SFO neuron activity, providing a basis for TNF-α hypertensive and sympathetic effects.NEW & NOTEWORTHY Considerable recent evidence has suggested important links between inflammation and the pathological mechanisms underlying hypertension. The present study describes cellular mechanisms through which acute and long-term exposure of tumor necrosis factor-α (TNF-α) influences the activity of subfornical organ neurons by modulating the voltage-gated transient Na+ current. This provides critical new information regarding the specific pathological mechanisms through which inflammation and TNF-α in particular may result in the development of hypertension.
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Affiliation(s)
- Nick J Simpson
- Department of Biomedical and Molecular Sciences and Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada
| | - Alastair V Ferguson
- Department of Biomedical and Molecular Sciences and Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada
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Zeng M, Jiang W, Tian Y, Hao J, Cao Z, Liu Z, Fu C, Zhang P, Ma J. Andrographolide inhibits arrhythmias and is cardioprotective in rabbits. Oncotarget 2017; 8:61226-61238. [PMID: 28977859 PMCID: PMC5617419 DOI: 10.18632/oncotarget.18051] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/21/2017] [Indexed: 01/01/2023] Open
Abstract
Andrographolide has a protective effect on the cardiovascular system. To study its cardic-electrophysiological effects, action potentials and voltage-gated Na+ (INa), Ca2+ (ICaL), and K+ (IK1, IKr, Ito and IKur) currents were recorded using whole-cell patch clamp and current clamp techniques. Additionally, the effects of andrographolide on aconitine-induced arrhythmias were assessed on electrocardiograms in vivo. We found that andrographolide shortened action potential duration and reduced maximum upstroke velocity in rabbit left ventricular and left atrial myocytes. Andrographolide attenuated rate-dependence of action potential duration, and reduced or abolished delayed afterdepolarizations and triggered activities induced by isoproterenol (1 μM) and high calcium ([Ca2+]o=3.6 mM) in left ventricular myocytes. Andrographolide also concentration-dependently inhibited INa and ICaL, but had no effect on Ito, IKur, IK1, or IKr in rabbit left ventricular and left atrial myocytes. Andrographolide treatment increased the time and dosage thresholds of aconitine-induced arrhythmias, and reduced arrhythmia incidence and mortality in rabbits. Our results indicate that andrographolide inhibits cellular arrhythmias (delayed afterdepolarizations and triggered activities) and aconitine-induced arrhythmias in vivo, and these effects result from INa and ICaL inhibition. Andrographolide may be useful as a class I and IV antiarrhythmic therapeutic.
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Affiliation(s)
- Mengliu Zeng
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Wanzhen Jiang
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Youjia Tian
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Jie Hao
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Zhenzhen Cao
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Zhipei Liu
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Chen Fu
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Peihua Zhang
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Jihua Ma
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
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Hydrogen sulfide inhibits giant depolarizing potentials and abolishes epileptiform activity of neonatal rat hippocampal slices. Neuroscience 2017; 340:153-165. [DOI: 10.1016/j.neuroscience.2016.10.051] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 10/12/2016] [Accepted: 10/21/2016] [Indexed: 11/20/2022]
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13
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Elies J, Scragg JL, Boyle JP, Gamper N, Peers C. Regulation of the T-type Ca(2+) channel Cav3.2 by hydrogen sulfide: emerging controversies concerning the role of H2 S in nociception. J Physiol 2016; 594:4119-29. [PMID: 26804000 DOI: 10.1113/jp270963] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 12/26/2015] [Indexed: 12/22/2022] Open
Abstract
Ion channels represent a large and growing family of target proteins regulated by gasotransmitters such as nitric oxide, carbon monoxide and, as described more recently, hydrogen sulfide. Indeed, many of the biological actions of these gases can be accounted for by their ability to modulate ion channel activity. Here, we report recent evidence that H2 S is a modulator of low voltage-activated T-type Ca(2+) channels, and discriminates between the different subtypes of T-type Ca(2+) channel in that it selectively modulates Cav3.2, whilst Cav3.1 and Cav3.3 are unaffected. At high concentrations, H2 S augments Cav3.2 currents, an observation which has led to the suggestion that H2 S exerts its pro-nociceptive effects via this channel, since Cav3.2 plays a central role in sensory nerve excitability. However, at more physiological concentrations, H2 S is seen to inhibit Cav3.2. This inhibitory action requires the presence of the redox-sensitive, extracellular region of the channel which is responsible for tonic metal ion binding and which particularly distinguishes this channel isoform from Cav3.1 and 3.3. Further studies indicate that H2 S may act in a novel manner to alter channel activity by potentiating the zinc sensitivity/affinity of this binding site. This review discusses the different reports of H2 S modulation of T-type Ca(2+) channels, and how such varying effects may impact on nociception given the role of this channel in sensory activity. This subject remains controversial, and future studies are required before the impact of T-type Ca(2+) channel modulation by H2 S might be exploited as a novel approach to pain management.
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Affiliation(s)
- Jacobo Elies
- Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Jason L Scragg
- Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - John P Boyle
- Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Nikita Gamper
- Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, UK.,Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Chris Peers
- Faculty of Medicine and Health, University of Leeds, Leeds, UK
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