1
|
Li Z, Gaitan-Espitia JD. Temperature-dependent toxicity of fluoxetine alters the thermal plasticity of marine diatoms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:172146. [PMID: 38569963 DOI: 10.1016/j.scitotenv.2024.172146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 03/15/2024] [Accepted: 03/30/2024] [Indexed: 04/05/2024]
Abstract
Anthropogenic activities have led to the emergence of pharmaceutical pollution in marine ecosystems, posing a significant threat to biodiversity in conjunction with global climate change. While the ecotoxicity of human drugs on aquatic organisms is increasingly recognized, their interactions with environmental factors, such as temperature, remain understudied. This research investigates the physiological effects of the selective serotonin reuptake inhibitor (SSRI), fluoxetine, on two diatom species, Phaeodactylum tricornutum and Thalassiosira weissflogii. Results demonstrate that fluoxetine significantly reduces growth rate and biomass production, concurrently affecting pigment contents and the thermal performance curve (TPC) of the diatoms. Fluoxetine reduces the synthesis of chlorophyll a (Chl a) and carotenoid (Car), indicating inhibition of photosynthesis and photoprotection. Furthermore, fluoxetine decreases the maximum growth rate (μmax) while increasing the optimum temperature (Topt) in both species, suggesting an altered thermal plasticity. This shift is attributed to the observed decrease in the inhibition rate of fluoxetine with rising temperatures. These findings emphasize the physiological impacts and ecological implications of fluoxetine on phytoplankton and underscore the significance of considering interactions between multiple environmental drivers when accessing the ecotoxicity of potential pollutants. The present study provides insights into crucial considerations for evaluating the impacts of pharmaceutical pollution on marine primary producers.
Collapse
Affiliation(s)
- Zhenzhen Li
- The SWIRE Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong
| | - Juan Diego Gaitan-Espitia
- The SWIRE Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong.
| |
Collapse
|
2
|
Delgado-Ramírez M, López-Serrano AL, Rodríguez-Menchaca AA. Inhibition of Kv2.1 potassium channels by the antidepressant drug sertraline. Eur J Pharmacol 2024; 970:176487. [PMID: 38458411 DOI: 10.1016/j.ejphar.2024.176487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/07/2024] [Accepted: 03/05/2024] [Indexed: 03/10/2024]
Abstract
Sertraline is a commonly used antidepressant of the selective serotonin reuptake inhibitors (SSRIs) class. In this study, we have used the patch-clamp technique to assess the effects of sertraline on Kv2.1 channels heterologously expressed in HEK-293 cells and on the voltage-gated potassium currents (IKv) of Neuro 2a cells, which are predominantly mediated by Kv2.1 channels. Our results reveal that sertraline inhibits Kv2.1 channels in a concentration-dependent manner. The sertraline-induced inhibition was not voltage-dependent and did not require the channels to be open. The kinetics of activation and deactivation were accelerated and decelerated, respectively, by sertraline. Moreover, the inhibition by this drug was use-dependent. Notably, sertraline significantly modified the inactivation mechanism of Kv2.1 channels; the steady-state inactivation was shifted to hyperpolarized potentials, the closed-state inactivation was enhanced and accelerated, and the recovery from inactivation was slowed, suggesting that this is the main mechanism by which sertraline inhibits Kv2.1 channels. Overall, this study provides novel insights into the pharmacological actions of sertraline on Kv2.1 channels, shedding light on the intricate interaction between SSRIs and ion channel function.
Collapse
Affiliation(s)
- Mayra Delgado-Ramírez
- Departamento de Fisiología y Biofísica, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí, SLP, 78210, Mexico.
| | - Ana Laura López-Serrano
- Departamento de Fisiología y Biofísica, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí, SLP, 78210, Mexico
| | - Aldo A Rodríguez-Menchaca
- Departamento de Fisiología y Biofísica, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí, SLP, 78210, Mexico
| |
Collapse
|
3
|
Matthews LG, Puryear CB, Correia SS, Srinivasan S, Belfort GM, Pan MK, Kuo SH. T-type calcium channels as therapeutic targets in essential tremor and Parkinson's disease. Ann Clin Transl Neurol 2023; 10:462-483. [PMID: 36738196 PMCID: PMC10109288 DOI: 10.1002/acn3.51735] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 02/05/2023] Open
Abstract
Neuronal action potential firing patterns are key components of healthy brain function. Importantly, restoring dysregulated neuronal firing patterns has the potential to be a promising strategy in the development of novel therapeutics for disorders of the central nervous system. Here, we review the pathophysiology of essential tremor and Parkinson's disease, the two most common movement disorders, with a focus on mechanisms underlying the genesis of abnormal firing patterns in the implicated neural circuits. Aberrant burst firing of neurons in the cerebello-thalamo-cortical and basal ganglia-thalamo-cortical circuits contribute to the clinical symptoms of essential tremor and Parkinson's disease, respectively, and T-type calcium channels play a key role in regulating this activity in both the disorders. Accordingly, modulating T-type calcium channel activity has received attention as a potentially promising therapeutic approach to normalize abnormal burst firing in these diseases. In this review, we explore the evidence supporting the theory that T-type calcium channel blockers can ameliorate the pathophysiologic mechanisms underlying essential tremor and Parkinson's disease, furthering the case for clinical investigation of these compounds. We conclude with key considerations for future investigational efforts, providing a critical framework for the development of much needed agents capable of targeting the dysfunctional circuitry underlying movement disorders such as essential tremor, Parkinson's disease, and beyond.
Collapse
Affiliation(s)
| | - Corey B Puryear
- Praxis Precision Medicines, Boston, Massachusetts, 02110, USA
| | | | - Sharan Srinivasan
- Praxis Precision Medicines, Boston, Massachusetts, 02110, USA.,Department of Neurology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | | | - Ming-Kai Pan
- Department and Graduate Institute of Pharmacology, National Taiwan University College of Medicine, Taipei, 10051, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, 10617, Taiwan.,Department of Medical Research, National Taiwan University Hospital, Taipei, 10002, Taiwan.,Cerebellar Research Center, National Taiwan University Hospital, Yun-Lin Branch, Yun-Lin, 64041, Taiwan
| | - Sheng-Han Kuo
- Department of Neurology, Columbia University, New York, New York, 10032, USA.,Initiative for Columbia Ataxia and Tremor, Columbia University, New York, New York, 10032, USA
| |
Collapse
|
4
|
T-Type Calcium Channels: A Mixed Blessing. Int J Mol Sci 2022; 23:ijms23179894. [PMID: 36077291 PMCID: PMC9456242 DOI: 10.3390/ijms23179894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 11/17/2022] Open
Abstract
The role of T-type calcium channels is well established in excitable cells, where they preside over action potential generation, automaticity, and firing. They also contribute to intracellular calcium signaling, cell cycle progression, and cell fate; and, in this sense, they emerge as key regulators also in non-excitable cells. In particular, their expression may be considered a prognostic factor in cancer. Almost all cancer cells express T-type calcium channels to the point that it has been considered a pharmacological target; but, as the drugs used to reduce their expression are not completely selective, several complications develop, especially within the heart. T-type calcium channels are also involved in a specific side effect of several anticancer agents, that act on microtubule transport, increase the expression of the channel, and, thus, the excitability of sensory neurons, and make the patient more sensitive to pain. This review puts into context the relevance of T-type calcium channels in cancer and in chemotherapy side effects, considering also the cardiotoxicity induced by new classes of antineoplastic molecules.
Collapse
|
5
|
Quintin S, Barpujari A, Mehkri Y, Hernandez J, Lucke-Wold B. The glymphatic system and subarachnoid hemorrhage: disruption and recovery. EXPLORATION OF NEUROPROTECTIVE THERAPY 2022; 2:118-130. [PMID: 35756328 PMCID: PMC9221287 DOI: 10.37349/ent.2022.00023] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/09/2022] [Indexed: 01/01/2023]
Abstract
The glymphatic system, or glial-lymphatic system, is a waste clearance system composed of perivascular channels formed by astrocytes that mediate the clearance of proteins and metabolites from the brain. These channels facilitate the movement of cerebrospinal fluid throughout brain parenchyma and are critical for homeostasis. Disruption of the glymphatic system leads to an accumulation of these waste products as well as increased interstitial fluid in the brain. These phenomena are also seen during and after subarachnoid hemorrhages (SAH), contributing to the brain damage seen after rupture of a major blood vessel. Herein this review provides an overview of the glymphatic system, its disruption during SAH, and its function in recovery following SAH. The review also outlines drugs which target the glymphatic system and may have therapeutic applications following SAH.
Collapse
Affiliation(s)
- Stephan Quintin
- Department of Neurosurgery, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Arnav Barpujari
- Department of Neurosurgery, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Yusuf Mehkri
- Department of Neurosurgery, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Jairo Hernandez
- Department of Neurosurgery, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Brandon Lucke-Wold
- Department of Neurosurgery, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| |
Collapse
|
6
|
Khan MS, Shahwan M, Shamsi A, Alhumaydhi FA, Alsagaby SA, Al Abdulmonem W, Abdullaev B, Yadav DK. Elucidating the Interactions of Fluoxetine with Human Transferrin Employing Spectroscopic, Calorimetric, and In Silico Approaches: Implications of a Potent Alzheimer's Drug. ACS OMEGA 2022; 7:9015-9023. [PMID: 35309456 PMCID: PMC8928501 DOI: 10.1021/acsomega.2c00182] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 02/21/2022] [Indexed: 06/12/2023]
Abstract
Neurodegenerative complexities, such as dementia, Alzheimer's disease (AD), and so forth, have been a crucial health concern for ages. Transferrin (Tf) is a chief target to explore in AD management. Fluoxetine (FXT) presents itself as a potent anti-AD drug-like compound and has been explored against several diseases based on the drug repurposing readings. The present study delineates the binding of FXT to Tf employing structure-based docking, molecular dynamics (MD) simulations, and principal component analysis (PCA). Docking results showed the binding of FXT with Tf with an appreciable binding affinity, making various close interactions. MD simulation of FXT with Tf for 100 ns suggested their stable binding without any significant structural alteration. Furthermore, fluorescence-based binding revealed a significant interaction between FXT and Tf. FXT binds to Tf with a binding constant of 5.5 × 105 M-1. Isothermal titration calorimetry (ITC) advocated the binding of FXT to Tf as spontaneous in nature, affirming earlier observations. This work indicated plausible interactions between FXT and Tf, which are worth considering for further studies in the clinical management of neurological disorders, including AD.
Collapse
Affiliation(s)
- Mohd Shahnawaz Khan
- Department
of Biochemistry, College of Sciences, King
Saud University, Riyadh 11451, Saudi Arabia
| | - Moyad Shahwan
- College
of Pharmacy & Health Sciences, Ajman
University, Ajman 346, United Arab Emirates
- Centre
of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman 346, United Arab Emirates
| | - Anas Shamsi
- Centre
of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman 346, United Arab Emirates
- Centre
for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Fahad A. Alhumaydhi
- Department
of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah 51452, Saudi Arabia
| | - Suliman A. Alsagaby
- Department
of Medical Laboratories Sciences, College of Applied Medical Sciences, Majmaah University, Majmaah 11932, Saudi Arabia
| | - Waleed Al Abdulmonem
- Department
of Pathology, College of Medicine, Qassim
University, Buraydah 51452, Saudi Arabia
| | | | - Dharmendra Kumar Yadav
- College
of Pharmacy, Gachon University of Medicine
and Science, Hambakmoeiro, Yeonsu-gu, Incheon City 21924, South Korea
| |
Collapse
|
7
|
Cav3.1-driven bursting firing in ventromedial hypothalamic neurons exerts dual control of anxiety-like behavior and energy expenditure. Mol Psychiatry 2022; 27:2901-2913. [PMID: 35318460 PMCID: PMC9156408 DOI: 10.1038/s41380-022-01513-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 02/22/2022] [Accepted: 02/25/2022] [Indexed: 12/22/2022]
Abstract
The central nervous system has evolved to coordinate the regulation of both the behavior response to the external environment and homeostasis of energy expenditure. Recent studies have indicated the dorsomedial ventromedial hypothalamus (dmVMH) as an important hub that regulates both innate behavior and energy homeostasis for coping stress. However, how dmVMH neurons control neuronal firing pattern to regulate chronic stress-induced anxiety and energy expenditure remains poorly understood. Here, we found enhanced neuronal activity in VMH after chronic stress, which is mainly induced by increased proportion of burst firing neurons. This enhancement of VMH burst firing is predominantly mediated by Cav3.1 expression. Optogenetically evoked burst firing of dmVMH neurons induced anxiety-like behavior, shifted the respiratory exchange ratio toward fat oxidation, and decreased food intake, while knockdown of Cav3.1 in the dmVMH had the opposite effects, suggested that Cav 3.1 as a crucial regulator. Interestingly, we found that fluoxetine (anxiolytics) could block the increase of Cav3.1 expression to inhibit the burst firing, and then rescued the anxiety-like behaviors and energy expenditure changes. Collectively, our study first revealed an important role of Cav3.1-driven bursting firing of dmVMH neurons in the control of anxiety-like behavior and energy expenditure, and provided potential therapeutic targets for treating the chronic stress-induced emotional malfunction and metabolism disorders.
Collapse
|
8
|
Perissinotti PP, Martínez-Hernández E, He Y, Koob MD, Piedras-Rentería ES. Genetic Deletion of KLHL1 Leads to Hyperexcitability in Hypothalamic POMC Neurons and Lack of Electrical Responses to Leptin. Front Neurosci 2021; 15:718464. [PMID: 34566565 PMCID: PMC8458657 DOI: 10.3389/fnins.2021.718464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/05/2021] [Indexed: 11/13/2022] Open
Abstract
Kelch-like 1 (KLHL1) is a neuronal actin-binding protein that modulates voltage-gated calcium channels. The KLHL1 knockout (KO) model displays altered calcium channel expression in various brain regions. We analyzed the electrical behavior of hypothalamic POMC (proopiomelanocortin) neurons and their response to leptin. Leptin's effects on POMC neurons include enhanced gene expression, activation of the ERK1/2 pathway and increased electrical excitability. The latter is initiated by activation of the Jak2-PI3K-PLC pathway, which activates TRPC1/5 (Transient Receptor Potential Cation) channels that in turn recruit T-type channel activity resulting in increased excitability. Here we report over-expression of CaV3.1 T-type channels in the hypothalamus of KLHL1 KO mice increased T-type current density and enhanced POMC neuron basal excitability, rendering them electrically unresponsive to leptin. Electrical sensitivity to leptin was restored by partial blockade of T-type channels. The overexpression of hypothalamic T-type channels in POMC neurons may partially contribute to the obese and abnormal feeding phenotypes observed in KLHL1 KO mice.
Collapse
Affiliation(s)
- Paula P Perissinotti
- Cell and Molecular Physiology Department and Neuroscience Division of the Cardiovascular Research Institute, Loyola University Chicago, Maywood, IL, United States
| | - Elizabeth Martínez-Hernández
- Cell and Molecular Physiology Department and Neuroscience Division of the Cardiovascular Research Institute, Loyola University Chicago, Maywood, IL, United States
| | - Yungui He
- Institute for Translational Neuroscience and Department of Lab Medicine & Pathology, University of Minnesota, Minneapolis, MN, United States
| | - Michael D Koob
- Institute for Translational Neuroscience and Department of Lab Medicine & Pathology, University of Minnesota, Minneapolis, MN, United States
| | - Erika S Piedras-Rentería
- Cell and Molecular Physiology Department and Neuroscience Division of the Cardiovascular Research Institute, Loyola University Chicago, Maywood, IL, United States
| |
Collapse
|
9
|
Rahban R, Rehfeld A, Schiffer C, Brenker C, Egeberg Palme DL, Wang T, Lorenz J, Almstrup K, Skakkebaek NE, Strünker T, Nef S. The antidepressant Sertraline inhibits CatSper Ca2+ channels in human sperm. Hum Reprod 2021; 36:2638-2648. [PMID: 34486673 PMCID: PMC8450872 DOI: 10.1093/humrep/deab190] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 06/01/2021] [Indexed: 12/12/2022] Open
Abstract
STUDY QUESTION Do selective serotonin reuptake inhibitor (SSRI) antidepressants affect the function of human sperm? SUMMARY ANSWER The SSRI antidepressant Sertraline (e.g. Zoloft) inhibits the sperm-specific Ca2+ channel CatSper and affects human sperm function in vitro. WHAT IS KNOWN ALREADY In human sperm, CatSper translates changes of the chemical microenvironment into changes of the intracellular Ca2+ concentration ([Ca2+]i) and swimming behavior. CatSper is promiscuously activated by oviductal ligands, but also by synthetic chemicals that might disturb the fertilization process. It is well known that SSRIs have off-target actions on Ca2+, Na+ and K+ channels in somatic cells. Whether SSRIs affect the activity of CatSper is, however, unknown. STUDY DESIGN, SIZE, DURATION We studied the action of the seven drugs belonging to the most commonly prescribed class of antidepressants, SSRIs, on resting [Ca2+]i and Ca2+ influx via CatSper in human sperm. The SSRI Sertraline was selected for in-depth analysis of its action on steroid-, prostaglandin-, pH- and voltage-activation of human CatSper. Moreover, the action of Sertraline on sperm acrosomal exocytosis and penetration into viscous media was evaluated. PARTICIPANTS/MATERIALS, SETTING, METHODS The activity of CatSper was investigated in sperm of healthy volunteers, using kinetic Ca2+ fluorimetry and patch-clamp recordings. Acrosomal exocytosis was investigated using Pisum sativum agglutinin and image cytometry. Sperm penetration in viscous media was evaluated using the Kremer test. MAIN RESULTS AND THE ROLE OF CHANCE Several SSRIs affected [Ca2+]i and attenuated ligand-induced Ca2+ influx via CatSper. In particular, the SSRI Sertraline almost completely suppressed Ca2+ influx via CatSper. Remarkably, the drug was about four-fold more potent to suppress prostaglandin- versus steroid-induced Ca2+ influx. Sertraline also suppressed alkaline- and voltage-activation of CatSper, indicating that the drug directly inhibits the channel. Finally, Sertraline impaired ligand-induced acrosome reaction and sperm penetration into viscous media. LIMITATIONS, REASONS FOR CAUTION This is an in vitro study. Future studies have to assess the physiological relevance in vivo. WIDER IMPLICATIONS OF THE FINDINGS The off-target action of Sertraline on CatSper in human sperm might impair the fertilization process. In a research setting, Sertraline may be used to selectively inhibit prostaglandin-induced Ca2+ influx. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the Swiss Centre for Applied Human Toxicology (SCAHT), the Département de l’Instruction Publique of the State of Geneva, the German Research Foundation (CRU326), the Interdisciplinary Center for Clinical Research, Münster (IZKF; Str/014/21), the Innovation Fund Denmark (grant numbers 14-2013-4) and the EDMaRC research grant from the Kirsten and Freddy Johansen’s Foundation. The authors declare that no conflict of interest could be perceived as prejudicing the impartiality of the research reported. TRIAL REGISTRATION NUMBER NA.
Collapse
Affiliation(s)
- Rita Rahban
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland.,Swiss Centre for Applied Human Toxicology, Basel, Switzerland
| | - Anders Rehfeld
- Department of Growth and Reproduction, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Christian Schiffer
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Christoph Brenker
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | | | - Tao Wang
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany.,Institute of Life Science and School of Life Science, Nanchang University, Nanchang, Jiangxi, PR China
| | - Johannes Lorenz
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Kristian Almstrup
- Department of Growth and Reproduction, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Niels E Skakkebaek
- Department of Growth and Reproduction, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Timo Strünker
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Serge Nef
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland.,Swiss Centre for Applied Human Toxicology, Basel, Switzerland
| |
Collapse
|
10
|
Pereyra AE, Mininni CJ, Zanutto BS. Information capacity and robustness of encoding in the medial prefrontal cortex are modulated by the bioavailability of serotonin and the time elapsed from the cue during a reward-driven task. Sci Rep 2021; 11:13882. [PMID: 34230550 PMCID: PMC8260631 DOI: 10.1038/s41598-021-93313-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/23/2021] [Indexed: 02/06/2023] Open
Abstract
Serotonin (5-HT) is a key neuromodulator of medial prefrontal cortex (mPFC) functions. Pharmacological manipulation of systemic 5-HT bioavailability alters the electrical activity of mPFC neurons. However, 5-HT modulation at the population level is not well characterized. In the present study, we made single neuron extracellular recordings in the mPFC of rats performing an operant conditioning task, and analyzed the effect of systemic administration of fluoxetine (a selective serotonin reuptake inhibitor) on the information encoded in the firing activity of the neural population. Chronic (longer than 15 days), but not acute (less than 15 days), fluoxetine administration reduced the firing rate of mPFC neurons. Moreover, fluoxetine treatment enhanced pairwise entropy but diminished noise correlation and redundancy in the information encoded, thus showing how mPFC differentially encodes information as a function of 5-HT bioavailability. Information about the occurrence of the reward-predictive stimulus was maximized during reward consumption, around 3 to 4 s after the presentation of the cue, and it was higher under chronic fluoxetine treatment. However, the encoded information was less robust to noise corruption when compared to control conditions.
Collapse
Affiliation(s)
- A Ezequiel Pereyra
- Instituto de Biología y Medicina Experimental (IBYME), CONICET, Buenos Aires, Argentina.
| | - Camilo J Mininni
- Instituto de Biología y Medicina Experimental (IBYME), CONICET, Buenos Aires, Argentina
| | - B Silvano Zanutto
- Instituto de Biología y Medicina Experimental (IBYME), CONICET, Buenos Aires, Argentina
- Universidad de Buenos Aires, Facultad de Ingeniería, Instituto de Ingeniería Biomédica, Buenos Aires, Argentina
| |
Collapse
|
11
|
Perissinotti PP, Martínez-Hernández E, Piedras-Rentería ES. TRPC1/5-Ca V 3 Complex Mediates Leptin-Induced Excitability in Hypothalamic Neurons. Front Neurosci 2021; 15:679078. [PMID: 34177455 PMCID: PMC8226082 DOI: 10.3389/fnins.2021.679078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 04/30/2021] [Indexed: 12/17/2022] Open
Abstract
Leptin regulates hypothalamic POMC+ (pro-opiomelanocortin) neurons by inducing TRPC (Transient Receptor Potential Cation) channel-mediate membrane depolarization. The role of TRPC channels in POMC neuron excitability is clearly established; however, it remains unknown whether their activity alone is sufficient to trigger excitability. Here we show that the right-shift voltage induced by the leptin-induced TRPC channel-mediated depolarization of the resting membrane potential brings T-type channels into the active window current range, resulting in an increase of the steady state T-type calcium current from 40 to 70% resulting in increased intrinsic excitability of POMC neurons. We assessed the role and timing of T-type channels on excitability and leptin-induced depolarization in vitro in cultured mouse POMC neurons. The involvement of TRPC channels in the leptin-induced excitability of POMC neurons was corroborated by using the TRPC channel inhibitor 2APB, which precluded the effect of leptin. We demonstrate T-type currents are indispensable for both processes, as treatment with NNC-55-0396 prevented the membrane depolarization and rheobase changes induced by leptin. Furthermore, co-immunoprecipitation experiments suggest that TRPC1/5 channels and CaV3.1 and CaV3.2 channels co-exist in complex. The functional relevance of this complex was corroborated using intracellular Ca2+ chelators; intracellular BAPTA (but not EGTA) application was sufficient to preclude POMC neuron excitability. However, leptin-induced depolarization still occurred in the presence of either BAPTA or EGTA suggesting that the calcium entry necessary to self-activate the TRPC1/5 complex is not blocked by the presence of BAPTA in hypothalamic neurons. Our study establishes T-type channels as integral part of the signaling cascade induced by leptin, modulating POMC neuron excitability. Leptin activation of TRPC channels existing in a macromolecular complex with T-type channels recruits the latter by locally induced membrane depolarization, further depolarizing POMC neurons, triggering action potentials and excitability.
Collapse
Affiliation(s)
- Paula P Perissinotti
- Cell and Molecular Physiology Department and Neuroscience Division of the Cardiovascular Research Institute, Loyola University Chicago, Maywood, IL, United States
| | - Elizabeth Martínez-Hernández
- Cell and Molecular Physiology Department and Neuroscience Division of the Cardiovascular Research Institute, Loyola University Chicago, Maywood, IL, United States
| | - Erika S Piedras-Rentería
- Cell and Molecular Physiology Department and Neuroscience Division of the Cardiovascular Research Institute, Loyola University Chicago, Maywood, IL, United States
| |
Collapse
|
12
|
Inhibition of Fast Nerve Conduction Produced by Analgesics and Analgesic Adjuvants-Possible Involvement in Pain Alleviation. Pharmaceuticals (Basel) 2020; 13:ph13040062. [PMID: 32260535 PMCID: PMC7243109 DOI: 10.3390/ph13040062] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/29/2020] [Accepted: 04/01/2020] [Indexed: 02/07/2023] Open
Abstract
Nociceptive information is transmitted from the periphery to the cerebral cortex mainly by action potential (AP) conduction in nerve fibers and chemical transmission at synapses. Although this nociceptive transmission is largely inhibited at synapses by analgesics and their adjuvants, it is possible that the antinociceptive drugs inhibit nerve AP conduction, contributing to their antinociceptive effects. Many of the drugs are reported to inhibit the nerve conduction of AP and voltage-gated Na+ and K+ channels involved in its production. Compound action potential (CAP) is a useful measure to know whether drugs act on nerve AP conduction. Clinically-used analgesics and analgesic adjuvants (opioids, non-steroidal anti-inflammatory drugs, 2-adrenoceptor agonists, antiepileptics, antidepressants and local anesthetics) were found to inhibit fast-conducting CAPs recorded from the frog sciatic nerve by using the air-gap method. Similar actions were produced by antinociceptive plant-derived chemicals. Their inhibitory actions depended on the concentrations and chemical structures of the drugs. This review article will mention the inhibitory actions of the antinociceptive compounds on CAPs in frog and mammalian peripheral (particularly, sciatic) nerves and on voltage-gated Na+ and K+ channels involved in AP production. Nerve AP conduction inhibition produced by analgesics and analgesic adjuvants is suggested to contribute to at least a part of their antinociceptive effects.
Collapse
|
13
|
Fischer RA, Roux AL, Wareham LK, Sappington RM. Pressure-dependent modulation of inward-rectifying K + channels: implications for cation homeostasis and K + dynamics in glaucoma. Am J Physiol Cell Physiol 2019; 317:C375-C389. [PMID: 31166711 DOI: 10.1152/ajpcell.00444.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Glaucoma is the leading cause of blindness worldwide, resulting from degeneration of retinal ganglion cells (RGCs), which form the optic nerve. Prior to structural degeneration, RGCs exhibit physiological deficits. Müller glia provide homeostatic regulation of ions that supports RGC physiology through a process called K+ siphoning. Recent studies suggest that several retinal conditions, including glaucoma, involve changes in the expression of K+ channels in Müller glia. To clarify whether glaucoma-related stressors directly alter expression and function of K+ channels in Müller glia, we examined changes in the expression of inwardly rectifying K+ (Kir) channels and two-pore domain (K2P) channels in response to elevated intraocular pressure (IOP) in vivo and in vitro in primary cultures of Müller glia exposed to elevated hydrostatic pressure. We then measured outcomes of cell health, cation homeostasis, and cation flux in Müller glia cultures. Transcriptome analysis in a murine model of microbead-induced glaucoma revealed pressure-dependent downregulation of Kir and K2P channels in vivo. Changes in the expression and localization of Kir and K2P channels in response to elevated pressure were also found in Müller glia in vitro. Finally, we found that elevated pressure compromises the plasma membrane of Müller glia and induces cation dyshomeostasis that involves changes in ion flux through cation channels. Pressure-induced changes in cation flux precede both cation dyshomeostasis and membrane compromise. Our findings have implications for Müller glia responses to pressure-related conditions, i.e., glaucoma, and identify cation dyshomeostasis as a potential contributor to electrophysiological impairment observed in RGCs of glaucomatous retina.
Collapse
Affiliation(s)
- Rachel A Fischer
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Abigail L Roux
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Lauren K Wareham
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Rebecca M Sappington
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee.,Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee.,Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee
| |
Collapse
|
14
|
Ungvari Z, Tarantini S, Yabluchanskiy A, Csiszar A. Potential Adverse Cardiovascular Effects of Treatment With Fluoxetine and Other Selective Serotonin Reuptake Inhibitors (SSRIs) in Patients With Geriatric Depression: Implications for Atherogenesis and Cerebromicrovascular Dysregulation. Front Genet 2019; 10:898. [PMID: 31616477 PMCID: PMC6764114 DOI: 10.3389/fgene.2019.00898] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 08/23/2019] [Indexed: 12/12/2022] Open
Abstract
Late life depression is an important public health problem, which associates with increased risk of morbidity and mortality. Selective serotonin reuptake inhibitors (SSRIs), including fluoxetine, are often prescribed to treat geriatric depression. There is increasing evidence that fluoxetine and other SSRIs exert a wide range of cardiovascular side effects. Furthermore, there is evidence that aging may increase plasma level of SSRIs. In this overview, the potential role of side effects of treatment with fluoxetine and other SSRIs in the pathogenesis of age-related cardiovascular diseases, including atherogenesis, cardiac pathologies, and cerebromicrovascular impairment, is discussed.
Collapse
Affiliation(s)
- Zoltan Ungvari
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Translational Geroscience Laboratory, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
- Department of Public Health, Semmelweis University, Budapest, Hungary
- *Correspondence: Zoltan Ungvari,
| | - Stefano Tarantini
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Translational Geroscience Laboratory, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
- Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Andriy Yabluchanskiy
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Translational Geroscience Laboratory, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Anna Csiszar
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Translational Geroscience Laboratory, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| |
Collapse
|
15
|
Alboghobeish S, Naghizadeh B, Kheirollah A, Ghorbanzadeh B, Mansouri MT. Fluoxetine increases analgesic effects of morphine, prevents development of morphine tolerance and dependence through the modulation of L-type calcium channels expression in mice. Behav Brain Res 2018; 361:86-94. [PMID: 30550947 DOI: 10.1016/j.bbr.2018.12.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 12/08/2018] [Accepted: 12/10/2018] [Indexed: 12/14/2022]
Abstract
Here, we aimed to investigate the effects of fluoxetine on morphine-induced analgesia, as well as preventive effects of it on morphine induced tolerance and dependence in mice. We also elucidate the involvement of L-type Ca2+ channels in these phenomena. To induce morphine tolerance, mice were treated with morphine (50 mg/kg) for 3 consecutive days. To evaluate the involvement of the calcium channel in the effects of fluoxetine (5, 20 mg/kg), combination ineffective doses of the two L-type calcium channel blockers, nimodipine (5 mg/kg) or diltiazem (20 mg/kg) with flouxetine were used with each morphine dose. Nociceptive behavior was evaluated using hot-plate test, while physical dependence assessed by naloxone-precipitated withdrawal on the fourth day of experiment. The expression of Cav1.2 and Cav1.3 subunits of the L-type calcium channels in cortex and mesolimbic tissues were measured using western immunoassay. Results showed that co-administration of fluoxetine (20 mg/kg) with morphine increased its acute analgesia effect and prevented the induction of morphine antinociceptive tolerance and physical dependence in mice. Moreover, these effects was potentiated by pre-treatment with diltiazem or nimodipine. Results also showed up-regulation of the Cav1.3 and Cav1.2 expression in the cerebral cortex and mesolimbic regions through the development of morphine dependence. Moreover, chronic administration of fluoxetine with morphine reduced the observed up-regulation of Cav1.3 and Cav1.2 expression in cortex and mesolimbic tissues. Our data indicated that co-administering of fluoxetine with morphine could potentiate the antinociceptive effect of morphine, prevent morphine analgesia tolerance and attenuated the morphine withdrawal signs during induction phases. Moreover, we also pointed out for the first time the role of L-type Ca2+ channel channels in the modulatory effects of fluoxetine on the morphine-related effects.
Collapse
Affiliation(s)
- Soheila Alboghobeish
- Department of Pharmacology, School of Pharmacy, Toxicology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Bahareh Naghizadeh
- Department of Pharmacology, School of Pharmacy, Toxicology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Alireza Kheirollah
- Department of Biochemistry, Cellular &Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Behnam Ghorbanzadeh
- Department of Pharmacology, School of Medicine, Dezful University of Medical Sciences, Dezful, Iran
| | - Mohammad Taghi Mansouri
- Department of Pharmacology, School of Pharmacy, Toxicology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Neuroanesthesia Laboratory, Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA, USA.
| |
Collapse
|
16
|
Sun Y, Sun X, Qu H, Zhao S, Xiao T, Zhao C. Neuroplasticity and behavioral effects of fluoxetine after experimental stroke. Restor Neurol Neurosci 2018; 35:457-468. [PMID: 28854520 DOI: 10.3233/rnn-170725] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The brain can undergo self-repair and has the ability to compensate for functions lost after a stroke. The plasticity of the ischemic brain is influenced by several factors including aging and pharmacotherapy. Fluoxetine is an antidepressant which enhances serotonergic neurotransmission through selective inhibition of neuronal reuptake of serotonin. In clinical practice, fluoxetine alleviates the symptoms of post-stroke depression (PSD), helps motor recovery in stroke patients. In animal experiments, chronic administration of fluoxetine induces increased excitability of mature granule cells (GCs), enhancing axonal and dendritic reorganization, as well as promoting neurogenesis or angiogenesis in the dentate gurus (DG), but the effect of fluoxetine in the subventricular zone (SVZ) remains controversial. Meanwhile, chronic treatment with fluoxetine did not reverse age-dependent suppression of proliferation cells in the DG. Interestingly, although fluoxetine has been found to enhance neurogenesis in the DG in stroke rats, this property is not consistent with the behavioral recovery. More studies into this issue will be required to reveal how to translate enhanced neuronal plasticity into behavioral benefits. This review provides an update of the current knowledge about the neurogenesis and the fate of the newly generated cells after the use of fluoxetine, as well as its ability to promote a behavioral recovery after stroke in clinical and experimental results and attempts to define the therapeutic properties of fluoxetine in regenerative neuroscience.
Collapse
Affiliation(s)
- Yefei Sun
- Gastrointestinal Surgery, The First Hospital of China Medical University, Shenyang, China
| | - Xiaoyu Sun
- Department of Neurology, The People's Hospital of Liaoning Province, Shenyang, China
| | - Huiling Qu
- Department of Neurology, The People's Hospital of Liaoning Province, Shenyang, China
| | - Shanshan Zhao
- Neurology, The First Hospital of China Medical University, Shenyang, China
| | - Ting Xiao
- Dermatology, The First Hospital of China Medical University, Shenyang, China.,Key Laboratory of Immunodermatology, Ministry of Health, Ministry of Education, Shenyang, China
| | - Chuansheng Zhao
- Neurology, The First Hospital of China Medical University, Shenyang, China
| |
Collapse
|
17
|
Hirao R, Fujita T, Sakai A, Kumamoto E. Compound action potential inhibition produced by various antidepressants in the frog sciatic nerve. Eur J Pharmacol 2018; 819:122-128. [DOI: 10.1016/j.ejphar.2017.11.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/31/2017] [Accepted: 11/30/2017] [Indexed: 11/25/2022]
|
18
|
Modulation of T-type Ca2+ channels by Lavender and Rosemary extracts. PLoS One 2017; 12:e0186864. [PMID: 29073181 PMCID: PMC5658086 DOI: 10.1371/journal.pone.0186864] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 10/09/2017] [Indexed: 12/19/2022] Open
Abstract
Medicinal plants represent a significant reservoir of unexplored substances for early-stage drug discovery. Of interest, two flowering Mediterranean plants have been used for thousands of years for their beneficial effects on nervous disorders, including anxiety and mood. However, the therapeutic potential of these plants regarding their ability to target ion channels and neuronal excitability remains largely unknown. Towards this goal, we have investigated the ability of Lavender and Rosemary to modulate T-type calcium channels (TTCCs). TTCCs play important roles in neuronal excitability, neuroprotection, sensory processes and sleep. These channels are also involved in epilepsy and pain. Using the whole-cell patch-clamp technique, we have characterized how Lavender and Rosemary extracts, as well as their major active compounds Linalool and Rosmarinic acid, modulate the electrophysiological properties of recombinant TTCCs (CaV3.2) expressed in HEK-293T cells. Both the methanolic and essential oil extracts as well as the active compounds of these plants inhibit Cav3.2 current in a concentration-dependent manner. In addition, these products also induce a negative shift of the steady-state inactivation of CaV3.2 current with no change in the activation properties. Taken together, our findings reveal that TTCCs are a molecular target of the Lavender and Rosemary compounds, suggesting that inhibition of TTCCs could contribute to the anxiolytic and the neuroprotective effects of these plants.
Collapse
|
19
|
Rozas JL, Goitia B, Bisagno V, Urbano FJ. Differential alterations of intracellular [Ca 2+] dynamics induced by cocaine and methylphenidate in thalamocortical ventrobasal neurons. ACTA ACUST UNITED AC 2017; 2. [PMID: 28920083 DOI: 10.15761/tbr.1000114] [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: 11/08/2022]
Abstract
The ventrobasal (VB) thalamus relay nucleus processes information from rodents' whiskers, projecting to somatosensory cortex. Cocaine and methylphenidate (MPH) have been described to differentially alter intrinsic properties of, and spontaneous GABAergic input to, VB neurons. Here we studied using bis-fura 2 ratiometric fluorescence the effects of cocaine and MPH on intracellular [Ca2+] dynamics at the soma and dendrites of VB neurons. Cocaine increased baseline fluorescence in VB somatic and dendritic compartments. Peak and areas of fluorescence amplitudes were reduced by cocaine binge treatment in somas and dendrites at different holding potentials. MPH binge treatment did not alter ratiometric fluorescence at either somatic or dendritic levels. These novel cocaine-mediated blunting effects on intracellular [Ca2+] might account for alterations in the capacity of thalamocortical neurons to maintain gamma band oscillations, as well as their ability to integrate synaptic afferents.
Collapse
Affiliation(s)
- José L Rozas
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular "Dr. Héctor Maldonado", Ciudad Autónoma de Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Ciudad Autónoma de Buenos Aires
| | - Belén Goitia
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular "Dr. Héctor Maldonado", Ciudad Autónoma de Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Ciudad Autónoma de Buenos Aires
| | - Verónica Bisagno
- Universidad de Buenos Aires, Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Farmacológicas (ININFA), Ciudad Autónoma de Buenos Aires, Argentina
| | - Francisco J Urbano
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular "Dr. Héctor Maldonado", Ciudad Autónoma de Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Ciudad Autónoma de Buenos Aires
| |
Collapse
|
20
|
Sankhe S, Manousakidi S, Antigny F, Arthur Ataam J, Bentebbal S, Ruchon Y, Lecerf F, Sabourin J, Price L, Fadel E, Dorfmüller P, Eddahibi S, Humbert M, Perros F, Capuano V. T-type Ca 2+ channels elicit pro-proliferative and anti-apoptotic responses through impaired PP2A/Akt1 signaling in PASMCs from patients with pulmonary arterial hypertension. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1631-1641. [PMID: 28655554 DOI: 10.1016/j.bbamcr.2017.06.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 06/13/2017] [Accepted: 06/21/2017] [Indexed: 10/19/2022]
Abstract
Idiopathic pulmonary arterial hypertension (iPAH) is characterized by obstructive hyperproliferation and apoptosis resistance of distal pulmonary artery smooth muscle cells (PASMCs). T-type Ca2+ channel blockers have been shown to reduce experimental pulmonary hypertension, although the impact of T-type channel inhibition remains unexplored in PASMCs from iPAH patients. Here we show that T-type channels Cav3.1 and Cav3.2 are present in the lung and PASMCs from iPAH patients and control subjects. The blockade of T-type channels by the specific blocker, TTA-A2, prevents cell cycle progression and PASMCs growth. In iPAH cells, T-type channel signaling fails to activate phosphatase PP2A, leading to an increase in ERK1/2, P38 activation. Moreover, T-type channel signaling is redirected towards the activation of the kinase Akt1, leading to increased expression of the anti-apoptotic protein survivin, and a decrease in the pro-apoptotic mediator FoxO3A. Finally, in iPAH cells, Akt1 is no longer able to regulate caspase 9 activation, whereas T-type channel overexpression reverses PP2A defect in iPAH cells but reinforces the deleterious effects of Akt1 activation. Altogether, these data highlight T-type channel signaling as a strong trigger of the pathological phenotype of PASMCs from iPAH patients (hyper-proliferation/cells survival and apoptosis resistance), suggesting that both T-type channels and PP2A may be promising therapeutic targets for pulmonary hypertension.
Collapse
Affiliation(s)
- Safietou Sankhe
- INSERM U999, Hôpital Marie Lannelongue, Le Plessis Robinson, France; Univ. Paris-Sud, Faculté de Médecine, Univ. Paris-Saclay, Le Kremlin Bicêtre, France
| | - Sevasti Manousakidi
- INSERM U999, Hôpital Marie Lannelongue, Le Plessis Robinson, France; Univ. Paris-Sud, Faculté de Médecine, Univ. Paris-Saclay, Le Kremlin Bicêtre, France
| | - Fabrice Antigny
- INSERM U999, Hôpital Marie Lannelongue, Le Plessis Robinson, France; Univ. Paris-Sud, Faculté de Médecine, Univ. Paris-Saclay, Le Kremlin Bicêtre, France
| | - Jennifer Arthur Ataam
- INSERM U999, Hôpital Marie Lannelongue, Le Plessis Robinson, France; Univ. Paris-Sud, Faculté de Médecine, Univ. Paris-Saclay, Le Kremlin Bicêtre, France
| | - Sana Bentebbal
- PhyMedExp, Univ. Montpellier, Inserm U1046, cNRS UMR9214.34295 MINSERM U1046, Montpellier, France
| | - Yann Ruchon
- INSERM U999, Hôpital Marie Lannelongue, Le Plessis Robinson, France; Univ. Paris-Sud, Faculté de Médecine, Univ. Paris-Saclay, Le Kremlin Bicêtre, France
| | - Florence Lecerf
- INSERM U999, Hôpital Marie Lannelongue, Le Plessis Robinson, France; Univ. Paris-Sud, Faculté de Médecine, Univ. Paris-Saclay, Le Kremlin Bicêtre, France
| | - Jessica Sabourin
- INSERM UMR-S1180, Univ. Paris-Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France
| | - Laura Price
- National Pulmonary Hypertension Service, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK
| | - Elie Fadel
- INSERM U999, Hôpital Marie Lannelongue, Le Plessis Robinson, France; Univ. Paris-Sud, Faculté de Médecine, Univ. Paris-Saclay, Le Kremlin Bicêtre, France
| | - Peter Dorfmüller
- INSERM U999, Hôpital Marie Lannelongue, Le Plessis Robinson, France; Univ. Paris-Sud, Faculté de Médecine, Univ. Paris-Saclay, Le Kremlin Bicêtre, France
| | - Saadia Eddahibi
- PhyMedExp, Univ. Montpellier, Inserm U1046, cNRS UMR9214.34295 MINSERM U1046, Montpellier, France
| | - Marc Humbert
- INSERM U999, Hôpital Marie Lannelongue, Le Plessis Robinson, France; Univ. Paris-Sud, Faculté de Médecine, Univ. Paris-Saclay, Le Kremlin Bicêtre, France; AP-HP, Service de pneumologie, Hôpital Bicêtre, Le Kremlin Bicêtre, France
| | - Frédéric Perros
- INSERM U999, Hôpital Marie Lannelongue, Le Plessis Robinson, France; Univ. Paris-Sud, Faculté de Médecine, Univ. Paris-Saclay, Le Kremlin Bicêtre, France
| | - Véronique Capuano
- INSERM U999, Hôpital Marie Lannelongue, Le Plessis Robinson, France; Univ. Paris-Sud, Faculté de Médecine, Univ. Paris-Saclay, Le Kremlin Bicêtre, France.
| |
Collapse
|
21
|
Effects of in vitro, acute and chronic treatment with fluoxetine on the sympathetic neurotransmission of rat vas deferens. Auton Neurosci 2017; 203:17-24. [DOI: 10.1016/j.autneu.2016.10.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 09/26/2016] [Accepted: 10/24/2016] [Indexed: 11/24/2022]
|
22
|
Modulatory Action by the Serotonergic System: Behavior and Neurophysiology in Drosophila melanogaster. Neural Plast 2016; 2016:7291438. [PMID: 26989517 PMCID: PMC4773565 DOI: 10.1155/2016/7291438] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Revised: 12/09/2015] [Accepted: 12/13/2015] [Indexed: 01/13/2023] Open
Abstract
Serotonin modulates various physiological processes and behaviors. This study investigates the role of 5-HT in locomotion and feeding behaviors as well as in modulation of sensory-motor circuits. The 5-HT biosynthesis was dysregulated by feeding Drosophila larvae 5-HT, a 5-HT precursor, or an inhibitor of tryptophan hydroxylase during early stages of development. The effects of feeding fluoxetine, a selective serotonin reuptake inhibitor, during early second instars were also examined. 5-HT receptor subtypes were manipulated using RNA interference mediated knockdown and 5-HT receptor insertional mutations. Moreover, synaptic transmission at 5-HT neurons was blocked or enhanced in both larvae and adult flies. The results demonstrate that disruption of components within the 5-HT system significantly impairs locomotion and feeding behaviors in larvae. Acute activation of 5-HT neurons disrupts normal locomotion activity in adult flies. To determine which 5-HT receptor subtype modulates the evoked sensory-motor activity, pharmacological agents were used. In addition, the activity of 5-HT neurons was enhanced by expressing and activating TrpA1 channels or channelrhodopsin-2 while recording the evoked excitatory postsynaptic potentials (EPSPs) in muscle fibers. 5-HT2 receptor activation mediates a modulatory role in a sensory-motor circuit, and the activation of 5-HT neurons can suppress the neural circuit activity, while fluoxetine can significantly decrease the sensory-motor activity.
Collapse
|
23
|
Kim HJ, Jun I, Yoon JS, Jung J, Kim YK, Kim WK, Kim BJ, Song J, Kim SJ, Nam JH, Lee MG. Selective serotonin reuptake inhibitors facilitate ANO6 (TMEM16F) current activation and phosphatidylserine exposure. Pflugers Arch 2015; 467:2243-56. [PMID: 25630304 DOI: 10.1007/s00424-015-1692-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 01/15/2015] [Accepted: 01/16/2015] [Indexed: 11/30/2022]
Abstract
Anoctamin 6 (ANO6) is a member of the recently identified TMEM16/anoctamin protein family comprising Ca(2+)-activated Cl(-) channels that generate outward-rectifying ionic currents in response to intracellular Ca(2+) increase. ANO6 is also essential for Ca(2+)-dependent phospholipid scrambling required for blood coagulation. Selective serotonin reuptake inhibitors (SSRIs)--fluoxetine, sertraline, and paroxetine-that are used for the treatment of major depressive disorders can increase the risk of upper gastrointestinal bleeding after chronic treatment. However, at the earlier stage of intake, which is 1-7 days after the treatment, the possibility of blood coagulation might also increase, but transiently. Therefore, in this study, we investigated whether therapeutic SSRI concentrations affected the Cl(-) current or phospholipid scrambling activity of ANO6 by assessing ANO6 currents (I ANO6), phosphatidylserine (PS) exposure, and platelet aggregation. In the whole-cell patch mode, SSRIs facilitated Ca(2+)-dependent activation of IANO6 in ANO6-transfected cells, as evidenced by a significant decrease in the delay of IANO6 generation. On the other hand, in the inside-out patch clamp configuration, SSRIs showed an inhibitory effect on ANO6 currents, suggesting that SSRIs activate ANO6 via an indirect mechanism in intact cells. SSRIs also facilitated Ca(2+)-dependent PS exposure and α-thrombin-induced platelet aggregation. These results indicate that SSRIs at clinically relevant concentrations promote Ca(2+)-dependent activation of ANO6, which may have potential clinical implications such as the underlying mechanism of SSRI-induced adverse drug reactions.
Collapse
Affiliation(s)
- Hyun Jong Kim
- Department of Physiology, Dongguk University College of Medicine, 123 Dongdae-ro, Kyungju, 780-714, Republic of Korea
| | - Ikhyun Jun
- Department of Pharmacology, BK21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea
| | - Jae Seok Yoon
- Biochemistry and Molecular Biology, Oregon Health Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Jinsei Jung
- Department of Pharmacology, BK21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea
| | - Yung Kyu Kim
- Department of Physiology, Dongguk University College of Medicine, 123 Dongdae-ro, Kyungju, 780-714, Republic of Korea
| | - Woo Kyung Kim
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, 27 Dongguk-ro, Ilsan Dong-gu, Goyang, 410-773, Republic of Korea
- Department of Internal Medicine Graduate School of Medicine, Dongguk University, 27 Dongguk-ro, Ilsan Dong-gu, Goyang, 410-773, Republic of Korea
| | - Byung Joo Kim
- Division of Longevity and Biofunctional Medicine, Pusan National University School of Korean Medicine, 49 Busandaehak-ro, Yangsan, 626-870, Republic of Korea
| | - Jaewoo Song
- Department of Laboratory Medicine, Yonsei University College of Medicine, 50 Yonsei-ro, Seoul, 120-752, Republic of Korea
| | - Sung Joon Kim
- Department of Physiology, Seoul National University College of Medicine, 28 Yongon-dong, Chongro-gu, Seoul, 110-799, Republic of Korea
| | - Joo Hyun Nam
- Department of Physiology, Dongguk University College of Medicine, 123 Dongdae-ro, Kyungju, 780-714, Republic of Korea.
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, 27 Dongguk-ro, Ilsan Dong-gu, Goyang, 410-773, Republic of Korea.
| | - Min Goo Lee
- Department of Pharmacology, BK21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea
| |
Collapse
|
24
|
Leuchter AF, Hunter AM, Krantz DE, Cook IA. Rhythms and blues: modulation of oscillatory synchrony and the mechanism of action of antidepressant treatments. Ann N Y Acad Sci 2015; 1344:78-91. [PMID: 25809789 DOI: 10.1111/nyas.12742] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Treatments for major depressive disorder (MDD) act at different hierarchical levels of biological complexity, ranging from the individual synapse to the brain as a whole. Theories of antidepressant medication action traditionally have focused on the level of cell-to-cell interaction and synaptic neurotransmission. However, recent evidence suggests that modulation of synchronized electrical activity in neuronal networks is a common effect of antidepressant treatments, including not only medications, but also neuromodulatory treatments such as repetitive transcranial magnetic stimulation. Synchronization of oscillatory network activity in particular frequency bands has been proposed to underlie neurodevelopmental and learning processes, and also may be important in the mechanism of action of antidepressant treatments. Here, we review current research on the relationship between neuroplasticity and oscillatory synchrony, which suggests that oscillatory synchrony may help mediate neuroplastic changes related to neurodevelopment, learning, and memory, as well as medication and neuromodulatory treatment for MDD. We hypothesize that medication and neuromodulation treatments may have related effects on the rate and pattern of neuronal firing, and that these effects underlie antidepressant efficacy. Elucidating the mechanisms through which oscillatory synchrony may be related to neuroplasticity could lead to enhanced treatment strategies for MDD.
Collapse
Affiliation(s)
- Andrew F Leuchter
- Laboratory of Brain, Behavior, and Pharmacology, and the Depression Research and Clinic Program, Semel Institute for Neuroscience and Human Behavior at UCLA, Los Angeles, California; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, California
| | | | | | | |
Collapse
|
25
|
Gangarossa G, Laffray S, Bourinet E, Valjent E. T-type calcium channel Cav3.2 deficient mice show elevated anxiety, impaired memory and reduced sensitivity to psychostimulants. Front Behav Neurosci 2014; 8:92. [PMID: 24672455 PMCID: PMC3957728 DOI: 10.3389/fnbeh.2014.00092] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 03/03/2014] [Indexed: 01/28/2023] Open
Abstract
The fine-tuning of neuronal excitability relies on a tight control of Ca2+ homeostasis. The low voltage-activated (LVA) T-type calcium channels (Cav3.1, Cav3.2 and Cav3.3 isoforms) play a critical role in regulating these processes. Despite their wide expression throughout the central nervous system, the implication of T-type Cav3.2 isoform in brain functions is still poorly characterized. Here, we investigate the effect of genetic ablation of this isoform in affective disorders, including anxiety, cognitive functions as well as sensitivity to drugs of abuse. Using a wide range of behavioral assays we show that genetic ablation of the cacna1h gene results in an anxiety-like phenotype, whereas novelty-induced locomotor activity is unaffected. Deletion of the T-type channel Cav3.2 also triggers impairment of hippocampus-dependent recognition memories. Acute and sensitized hyperlocomotion induced by d-amphetamine and cocaine are dramatically reduced in T-type Cav3.2 deficient mice. In addition, the administration of the T-type blocker TTA-A2 prevented the expression of locomotor sensitization observed in wildtype mice. In conclusion, our data reveal that physiological activity of this specific Ca2+ channel is required for affective and cognitive behaviors. Moreover, our work highlights the interest of T-type channel blockers as therapeutic strategies to reverse drug-associated alterations.
Collapse
Affiliation(s)
- Giuseppe Gangarossa
- Institut de Génomique Fonctionnelle, CNRS UMR-5203, Montpellier, France ; INSERM U661, Montpellier, France ; Universités de Montpellier 1 and 2 UMR-5203, Montpellier, France
| | - Sophie Laffray
- Institut de Génomique Fonctionnelle, CNRS UMR-5203, Montpellier, France ; INSERM U661, Montpellier, France ; Universités de Montpellier 1 and 2 UMR-5203, Montpellier, France ; Laboratories of Excellence, Ion Channel Science and Therapeutics, Institut de Génomique Fonctionnelle Montpellier, France
| | - Emmanuel Bourinet
- Institut de Génomique Fonctionnelle, CNRS UMR-5203, Montpellier, France ; INSERM U661, Montpellier, France ; Universités de Montpellier 1 and 2 UMR-5203, Montpellier, France ; Laboratories of Excellence, Ion Channel Science and Therapeutics, Institut de Génomique Fonctionnelle Montpellier, France
| | - Emmanuel Valjent
- Institut de Génomique Fonctionnelle, CNRS UMR-5203, Montpellier, France ; INSERM U661, Montpellier, France ; Universités de Montpellier 1 and 2 UMR-5203, Montpellier, France
| |
Collapse
|
26
|
Kopecky BJ, Liang R, Bao J. T-type calcium channel blockers as neuroprotective agents. Pflugers Arch 2014; 466:757-65. [PMID: 24563219 DOI: 10.1007/s00424-014-1454-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 01/15/2014] [Accepted: 01/19/2014] [Indexed: 01/12/2023]
Abstract
T-type calcium channels are expressed in many diverse tissues, including neuronal, cardiovascular, and endocrine. T-type calcium channels are known to play roles in the development, maintenance, and repair of these tissues but have also been implicated in disease when not properly regulated. Calcium channel blockers have been developed to treat various diseases and their use clinically is widespread due to both their efficacy as well as their safety. Aside from their established clinical applications, recent studies have suggested neuroprotective effects of T-type calcium channel blockers. Many of the current T-type calcium channel blockers could act on other molecular targets besides T-type calcium channels making it uncertain whether their neuroprotective effects are solely due to blocking of T-type calcium channels. In this review, we discuss these drugs as well as newly developed chemical compounds that are designed to be more selective for T-type calcium channels. We review in vitro and in vivo evidence of neuroprotective effects by these T-type calcium channel blockers. We conclude by discussing possible molecular mechanisms underlying the neuroprotective effects by T-type calcium channel blockers.
Collapse
Affiliation(s)
- Benjamin J Kopecky
- Department of Otolaryngology, Center for Aging, Washington University School of Medicine, 4560 Clayton Avenue, St. Louis, MO, 63110, USA
| | | | | |
Collapse
|
27
|
Jung J, Loy K, Schilling EM, Röther M, Brauner JM, Huth T, Schlötzer-Schrehardt U, Alzheimer C, Kornhuber J, Welzel O, Groemer TW. The Antidepressant Fluoxetine Mobilizes Vesicles to the Recycling Pool of Rat Hippocampal Synapses During High Activity. Mol Neurobiol 2013; 49:916-30. [DOI: 10.1007/s12035-013-8569-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 10/03/2013] [Indexed: 11/29/2022]
|
28
|
Choi KH. The design and discovery of T-type calcium channel inhibitors for the treatment of central nervous system disorders. Expert Opin Drug Discov 2013; 8:919-31. [DOI: 10.1517/17460441.2013.796926] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
29
|
Caiati MD, Cherubini E. Fluoxetine impairs GABAergic signaling in hippocampal slices from neonatal rats. Front Cell Neurosci 2013; 7:63. [PMID: 23641199 PMCID: PMC3640196 DOI: 10.3389/fncel.2013.00063] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 04/16/2013] [Indexed: 01/30/2023] Open
Abstract
Fluoxetine (Prozac), an antidepressant known to selectively inhibit serotonin reuptake, is widely used to treat mood disorders in women suffering from depression during pregnancy and postpartum period. Several lines of evidence suggest that this drug, which crosses the human placenta and is secreted into milk during lactation, exerts its action not only by interfering with serotoninergic but also with GABAergic transmission. GABA is known to play a crucial role in the construction of neuronal circuits early in postnatal development. The immature hippocampus is characterized by an early type of network activity, the so-called Giant Depolarizing Potentials (GDPs), generated by the synergistic action of glutamate and GABA, both depolarizing and excitatory. Here we tested the hypothesis that fluoxetine may interfere with GABAergic signaling during the first postnatal week, thus producing harmful effects on brain development. At micromolar concentrations fluoxetine severely depressed GDPs frequency (IC50 22 μM) in a reversible manner and independently of its action on serotonin reuptake. This effect was dependent on a reduced GABAergic (but not glutamatergic) drive to principal cells most probably from parvalbumin-positive fast spiking neurons. Cholecystokinin-positive GABAergic interneurons were not involved since the effects of the drug persisted when cannabinoid receptors were occluded with WIN55,212-2, a CB1/CB2 receptor agonist. Fluoxetine effects on GABAergic transmission were associated with a reduced firing rate of both principal cells and interneurons further suggesting that changes in network excitability account for GDPs disruption. This may have critical consequences on the functional organization and stabilization of neuronal circuits early in postnatal development.
Collapse
Affiliation(s)
- Maddalena D Caiati
- Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati Trieste, Italy
| | | |
Collapse
|
30
|
Chae YJ, Choi JS, Hahn SJ. Inhibition of Kv4.3 potassium channels by trazodone. Naunyn Schmiedebergs Arch Pharmacol 2013; 386:711-9. [DOI: 10.1007/s00210-013-0870-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 04/08/2013] [Indexed: 11/28/2022]
|
31
|
Cardamone L, Salzberg MR, O'Brien TJ, Jones NC. Antidepressant therapy in epilepsy: can treating the comorbidities affect the underlying disorder? Br J Pharmacol 2013; 168:1531-54. [PMID: 23146067 PMCID: PMC3605864 DOI: 10.1111/bph.12052] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 10/24/2012] [Accepted: 10/29/2012] [Indexed: 12/20/2022] Open
Abstract
There is a high incidence of psychiatric comorbidity in people with epilepsy (PWE), particularly depression. The manifold adverse consequences of comorbid depression have been more clearly mapped in recent years. Accordingly, considerable efforts have been made to improve detection and diagnosis, with the result that many PWE are treated with antidepressant drugs, medications with the potential to influence both epilepsy and depression. Exposure to older generations of antidepressants (notably tricyclic antidepressants and bupropion) can increase seizure frequency. However, a growing body of evidence suggests that newer ('second generation') antidepressants, such as selective serotonin reuptake inhibitors or serotonin-noradrenaline reuptake inhibitors, have markedly less effect on excitability and may lead to improvements in epilepsy severity. Although a great deal is known about how antidepressants affect excitability on short time scales in experimental models, little is known about the effects of chronic antidepressant exposure on the underlying processes subsumed under the term 'epileptogenesis': the progressive neurobiological processes by which the non-epileptic brain changes so that it generates spontaneous, recurrent seizures. This paper reviews the literature concerning the influences of antidepressants in PWE and in animal models. The second section describes neurobiological mechanisms implicated in both antidepressant actions and in epileptogenesis, highlighting potential substrates that may mediate any effects of antidepressants on the development and progression of epilepsy. Although much indirect evidence suggests the overall clinical effects of antidepressants on epilepsy itself are beneficial, there are reasons for caution and the need for further research, discussed in the concluding section.
Collapse
Affiliation(s)
- L Cardamone
- Department of Medicine (RMH), University of Melbourne, Melbourne, Victoria, Australia
| | | | | | | |
Collapse
|
32
|
|
33
|
Changes of cytosolic calcium and contractility of young rat vas deferens by acute treatment with amphetamine, fluoxetine or sibutramine. Eur J Pharmacol 2012; 691:52-60. [DOI: 10.1016/j.ejphar.2012.07.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 07/02/2012] [Accepted: 07/07/2012] [Indexed: 01/12/2023]
|
34
|
Receptor targets for antidepressant therapy in bipolar disorder: an overview. J Affect Disord 2012; 138:222-38. [PMID: 21601292 DOI: 10.1016/j.jad.2011.04.043] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Accepted: 04/27/2011] [Indexed: 11/20/2022]
Abstract
The treatment of bipolar depression is one of the most challenging issues in contemporary psychiatry. Currently only quetiapine and the olanzapine-fluoxetine combination are officially approved by the FDA against this condition. The neurobiology of bipolar depression and the possible targets of bipolar antidepressant therapy remain relatively elusive. We performed a complete and systematic review to identify agents with definite positive or negative results concerning efficacy followed by a second systematic review to identify the pharmacodynamic properties of these agents. The comparison of properties suggests that the stronger predictors for antidepressant efficacy in bipolar depression were norepinephrine alpha-1, dopamine D1 and histamine antagonism, followed by 5-HT2A, muscarinic and dopamine D2 and D3 antagonism and eventually by norepinephrine reuptake inhibition and 5HT-1A agonism. Serotonin reuptake which constitutes the cornerstone in unipolar depression treatment does not seem to play a significant role for bipolar depression. Our exhaustive review is compatible with a complex model with multiple levels of interaction between the major neurotransmitter systems without a single target being either necessary or sufficient to elicit the antidepressant effect in bipolar depression.
Collapse
|
35
|
Ferron L, Ruchon Y, Renaud JF, Capuano V. T-type Ca²+ signalling regulates aldosterone-induced CREB activation and cell death through PP2A activation in neonatal cardiomyocytes. Cardiovasc Res 2011; 90:105-12. [PMID: 21123217 PMCID: PMC3058735 DOI: 10.1093/cvr/cvq379] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 11/08/2010] [Accepted: 11/25/2010] [Indexed: 01/10/2023] Open
Abstract
AIMS We have investigated Ca²(+) signalling generated by aldosterone-induced T-type current (I(CaT)), the effects of I(CaT) in neonatal cardiomyocytes, and a putative role for I(CaT) in cardiomyocytes during cardiac pathology induced by stenosis in an adult rat. METHODS AND RESULTS Neonatal rat cardiomyocytes treated with aldosterone showed an increase in I(CaT) density, principally due to the upregulation of the T-type channel Ca(v)3.1 (by 80%). Aldosterone activated cAMP-response element-binding protein (CREB), and this activation was enhanced by blocking I(CaT) or by inhibiting protein phosphatase 2A (PP2A) activity. Aldosterone induced PP2A activity, an induction that was prevented upon I(CaT) blockade. I(CaT) exerted a negative feedback regulation on the transcription of the Ca(v)3.1 gene, and the activation of PP2A by I(CaT) led to increased levels of the pro-apoptotic markers caspase 9 and Bcl-x(S) and decreased levels of the anti-apoptotic marker Bcl-2. These findings were corroborated by flow cytometry analysis for apoptosis and necrosis. Similarly, in a rat model of cardiac disease, I(CaT) re-emergence was associated with a decrease in CREB activation and was correlated with increases in caspase 9 and Bcl-x(S) and a decrease in Bcl-2 levels. CONCLUSION Our findings establish PP2A/CREB as targets of I(CaT)-generated Ca²(+) signalling and identify an important role for I(CaT) in cardiomyocyte cell death.
Collapse
MESH Headings
- Aldosterone/metabolism
- Animals
- Animals, Newborn
- Apoptosis
- Calcium Channels, T-Type/genetics
- Calcium Channels, T-Type/metabolism
- Calcium Signaling
- Cardiomegaly/enzymology
- Cardiomegaly/pathology
- Caspase 9/metabolism
- Cells, Cultured
- Cyclic AMP Response Element-Binding Protein/metabolism
- Disease Models, Animal
- Enzyme Activation
- Flow Cytometry
- Male
- Membrane Potentials
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/pathology
- Necrosis
- Protein Phosphatase 2/metabolism
- Proto-Oncogene Proteins c-bcl-2/metabolism
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Receptors, Glucocorticoid/metabolism
- Time Factors
- Transcription, Genetic
- bcl-X Protein/metabolism
Collapse
Affiliation(s)
- Laurent Ferron
- Département de Recherche Médicale, Remodelage tissulaire et fonctionnel: signalisation et physiopathologieCNRS-UMR8162, Le Plessis Robinson, France
| | - Yann Ruchon
- Département de Recherche Médicale, Remodelage tissulaire et fonctionnel: signalisation et physiopathologieCNRS-UMR8162, Le Plessis Robinson, France
- INSERM-U999, Université Paris-Sud XI, Hôpital Marie Lannelongue, 133 ave de la Résistance, 9230 Le Plessis Robinson, France
| | - Jean-François Renaud
- Département de Recherche Médicale, Remodelage tissulaire et fonctionnel: signalisation et physiopathologieCNRS-UMR8162, Le Plessis Robinson, France
- INSERM-U999, Université Paris-Sud XI, Hôpital Marie Lannelongue, 133 ave de la Résistance, 9230 Le Plessis Robinson, France
| | - Véronique Capuano
- Département de Recherche Médicale, Remodelage tissulaire et fonctionnel: signalisation et physiopathologieCNRS-UMR8162, Le Plessis Robinson, France
- INSERM-U999, Université Paris-Sud XI, Hôpital Marie Lannelongue, 133 ave de la Résistance, 9230 Le Plessis Robinson, France
| |
Collapse
|
36
|
Zhong P, Yan Z. Differential regulation of the excitability of prefrontal cortical fast-spiking interneurons and pyramidal neurons by serotonin and fluoxetine. PLoS One 2011; 6:e16970. [PMID: 21383986 PMCID: PMC3044712 DOI: 10.1371/journal.pone.0016970] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 01/11/2011] [Indexed: 11/19/2022] Open
Abstract
Serotonin exerts a powerful influence on neuronal excitability. In this study, we investigated the effects of serotonin on different neuronal populations in prefrontal cortex (PFC), a major area controlling emotion and cognition. Using whole-cell recordings in PFC slices, we found that bath application of 5-HT dose-dependently increased the firing of FS (fast spiking) interneurons, and decreased the firing of pyramidal neurons. The enhancing effect of 5-HT in FS interneurons was mediated by 5-HT2 receptors, while the reducing effect of 5-HT in pyramidal neurons was mediated by 5-HT1 receptors. Fluoxetine, the selective serotonin reuptake inhibitor, also induced a concentration-dependent increase in the excitability of FS interneurons, but had little effect on pyramidal neurons. In rats with chronic fluoxetine treatment, the excitability of FS interneurons was significantly increased, while pyramidal neurons remained unchanged. Fluoxetine injection largely occluded the enhancing effect of 5-HT in FS interneurons, but did not alter the reducing effect of 5-HT in pyramidal neurons. These data suggest that the excitability of PFC interneurons and pyramidal neurons is regulated by exogenous 5-HT in an opposing manner, and FS interneurons are the major target of Fluoxetine. It provides a framework for understanding the action of 5-HT and antidepressants in altering PFC network activity.
Collapse
Affiliation(s)
- Ping Zhong
- Department of Physiology and Biophysics, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, United States of America
| | - Zhen Yan
- Department of Physiology and Biophysics, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, United States of America
- * E-mail:
| |
Collapse
|
37
|
Casamassima F, Hay AC, Benedetti A, Lattanzi L, Cassano GB, Perlis RH. L-type calcium channels and psychiatric disorders: A brief review. Am J Med Genet B Neuropsychiatr Genet 2010; 153B:1373-90. [PMID: 20886543 DOI: 10.1002/ajmg.b.31122] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Accepted: 07/28/2010] [Indexed: 01/11/2023]
Abstract
Emerging evidence from genome-wide association studies (GWAS) support the association of polymorphisms in the alpha 1C subunit of the L-type voltage-gated calcium channel gene (CACNA1C) with bipolar disorder. These studies extend a rich prior literature implicating dysfunction of L-type calcium channels (LTCCs) in the pathophysiology of neuropsychiatric disorders. Moreover, calcium channel blockers reduce Ca(2+) flux by binding to the α1 subunit of the LTCC and are used extensively for treating hypertension, preventing angina, cardiac arrhythmias and stroke. Calcium channel blockers have also been studied clinically in psychiatric conditions such as mood disorders and substance abuse/dependence, yielding conflicting results. In this review, we begin with a summary of LTCC pharmacology. For each category of disorder, this article then provides a review of animal and human data. In particular, we extensively focus on animal models of depression and clinical trials in mood disorders and substance abuse/dependence. Through examining rationale and study design of published clinical trials, we provide some of the possible reasons why we still do not have definitive evidence of efficacy of calcium-channel antagonists for mood disorders. Refinement of genetic results and target phenotypes, enrollment of adequate sample sizes in clinical trials and progress in physiologic and pharmacologic studies to synthesize tissue and isoform specific calcium channel antagonists, are all future challenges of research in this promising field. © 2010 Wiley-Liss, Inc.
Collapse
|
38
|
Giordanetto F, Knerr L, Wållberg A. T-type calcium channels inhibitors: a patent review. Expert Opin Ther Pat 2010; 21:85-101. [PMID: 21087200 DOI: 10.1517/13543776.2011.536532] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD T-type calcium channels are transmembrane proteins that regulate calcium entry in the cell in a voltage-dependent manner. Intracellular calcium levels are the key to many physiological processes, ranging from neuron firing to cardiac pacemaking. Inhibition of T-type calcium channels is heralded as a potential treatment to peripheral and CNS disorders, including hypertension, heart failure, sleep, epilepsy, drug addiction and neuropathic pain. AREAS COVERED IN THIS REVIEW A comprehensive summary of patent literature disclosing T-type calcium channels inhibitors is provided. WHAT THE READER WILL GAIN In all, 46 patent applications including 15 chemical structure classes are reviewed. Available in vitro, in vivo and clinical results are also discussed. TAKE HOME MESSAGE Several selective T-type calcium channels inhibitors with demonstrated in vitro and in vivo effects, including one Phase I clinical candidate, are now available. While future clinical results will be paramount to assess target validity in patients, these novel inhibitors represent excellent tools to further investigate the role of T-type channels in pathophysiological conditions.
Collapse
|
39
|
Determinants of synaptic integration and heterogeneity in rebound firing explored with data-driven models of deep cerebellar nucleus cells. J Comput Neurosci 2010; 30:633-58. [PMID: 21052805 PMCID: PMC3108018 DOI: 10.1007/s10827-010-0282-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 09/07/2010] [Accepted: 09/21/2010] [Indexed: 12/19/2022]
Abstract
Significant inroads have been made to understand cerebellar cortical processing but neural coding at the output stage of the cerebellum in the deep cerebellar nuclei (DCN) remains poorly understood. The DCN are unlikely to just present a relay nucleus because Purkinje cell inhibition has to be turned into an excitatory output signal, and DCN neurons exhibit complex intrinsic properties. In particular, DCN neurons exhibit a range of rebound spiking properties following hyperpolarizing current injection, raising the question how this could contribute to signal processing in behaving animals. Computer modeling presents an ideal tool to investigate how intrinsic voltage-gated conductances in DCN neurons could generate the heterogeneous firing behavior observed, and what input conditions could result in rebound responses. To enable such an investigation we built a compartmental DCN neuron model with a full dendritic morphology and appropriate active conductances. We generated a good match of our simulations with DCN current clamp data we recorded in acute slices, including the heterogeneity in the rebound responses. We then examined how inhibitory and excitatory synaptic input interacted with these intrinsic conductances to control DCN firing. We found that the output spiking of the model reflected the ongoing balance of excitatory and inhibitory input rates and that changing the level of inhibition performed an additive operation. Rebound firing following strong Purkinje cell input bursts was also possible, but only if the chloride reversal potential was more negative than −70 mV to allow de-inactivation of rebound currents. Fast rebound bursts due to T-type calcium current and slow rebounds due to persistent sodium current could be differentially regulated by synaptic input, and the pattern of these rebounds was further influenced by HCN current. Our findings suggest that active properties of DCN neurons could play a crucial role for signal processing in the cerebellum.
Collapse
|
40
|
P/Q and N channels control baseline and spike-triggered calcium levels in neocortical axons and synaptic boutons. J Neurosci 2010; 30:11858-69. [PMID: 20810905 DOI: 10.1523/jneurosci.2651-10.2010] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cortical axons contain a diverse range of voltage-activated ion channels, including Ca(2+) currents. Interestingly, Ca(2+) channels are not only located at presynaptic terminals, but also in the axon initial segment (AIS), suggesting a potentially important role in the regulation of action potential generation and neuronal excitability. Here, using two-photon microscopy and whole-cell patch-clamp recording, we examined the properties and role of calcium channels located in the AIS and presynaptic terminals of ferret layer 5 prefrontal cortical pyramidal cells in vitro. Subthreshold depolarization of the soma resulted in an increase in baseline and spike-triggered calcium concentration in both the AIS and nearby synaptic terminals. The increase in baseline calcium concentration rose with depolarization and fell with hyperpolarization with a time constant of approximately 1 s and was blocked by removal of Ca(2+) from the bathing medium. The increases in calcium concentration at the AIS evoked by subthreshold or suprathreshold depolarization of the soma were blocked by the P/Q-channel antagonist omega-agatoxin IVA or the N-channel antagonist omega-conotoxin GVIA or both. The presence of these channels in the AIS pyramidal cells was confirmed with immunochemistry. Block of these channels slowed axonal action potential repolarization, apparently from reduction of the activation of a Ca(2+)-activated K(+) current, and increased neuronal excitability. These results demonstrate novel mechanisms by which calcium currents may control the electrophysiological properties of axonal spike generation and neurotransmitter release in the neocortex.
Collapse
|
41
|
Kraus RL, Li Y, Gregan Y, Gotter AL, Uebele VN, Fox SV, Doran SM, Barrow JC, Yang ZQ, Reger TS, Koblan KS, Renger JJ. In vitro characterization of T-type calcium channel antagonist TTA-A2 and in vivo effects on arousal in mice. J Pharmacol Exp Ther 2010; 335:409-17. [PMID: 20682849 DOI: 10.1124/jpet.110.171058] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
T-type calcium channels have been implicated in many behaviorally important neurophysiological processes, and altered channel activity has been linked to the pathophysiology of neurological disorders such as insomnia, epilepsy, Parkinson's disease, depression, schizophrenia, and pain. We have previously identified a number of potent and selective T-type channel antagonists (Barrow et al., 2007; Shipe et al., 2008; Yang et al., 2008). Here we describe the properties of the antagonist TTA-A2 [2-(4-cyclopropylphenyl)-N-((1R)-1-{5-[(2,2,2-trifluoroethyl)oxo]-pyridin-2-yl}ethyl)acetamide], assessed in patch-clamp experiments. TTA-A2 blocks T-type channels (Ca(v)3.1, 3.2, 3.3) voltage dependently and with high potency (IC(50) ∼100 nM). Stimulation at 3 Hz revealed additional use dependence of inhibition. A hyperpolarized shift of the channel availability curve and delayed channel recovery from inactivation suggest that the compound preferentially interacts with and stabilizes inactivated channels. The compound showed a ∼300-fold selectivity for Ca(v)3 channels over high-voltage activated calcium channels. Inhibitory effects on native T-type currents were confirmed in brain slice recordings from the dorsal lateral geniculate nucleus and the subthalamic nucleus. Furthermore, we demonstrate that in vivo T-type channel inhibition by TTA-A2 suppresses active wake and promotes slow-wave sleep in wild-type mice but not in mice lacking both Ca(v)3.1 and Ca(v)3.3, suggesting the selective effect of TTA-A2 on recurrent thalamocortical network activity. The discovery of the potent and selective T-type channel antagonist TTA-A2 has enabled us to study the in vivo effects of pharmacological T-channel inhibition on arousal in mice, and it will help to explore the validity of these channels as potential drug targets for sleep-related and other neurological diseases.
Collapse
Affiliation(s)
- Richard L Kraus
- Department of Neuroscience, Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Henkel AW, Welzel O, Groemer TW, Tripal P, Rotter A, Kornhuber J. Fluoxetine prevents stimulation-dependent fatigue of synaptic vesicle exocytosis in hippocampal neurons. J Neurochem 2010; 114:697-705. [DOI: 10.1111/j.1471-4159.2010.06795.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
43
|
Xu F, Luk C, Richard MP, Zaidi W, Farkas S, Getz A, Lee A, van Minnen J, Syed NI. Antidepressant fluoxetine suppresses neuronal growth from both vertebrate and invertebrate neurons and perturbs synapse formation betweenLymnaeaneurons. Eur J Neurosci 2010; 31:994-1005. [DOI: 10.1111/j.1460-9568.2010.07129.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
44
|
Fluoxetine blocks myotonic runs and reverts abnormal surface electromyogram pattern in patients with myotonic dystrophy type 1. Clin Neuropharmacol 2010; 32:330-4. [PMID: 19667977 DOI: 10.1097/wnf.0b013e3181ae5546] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To verify the effects of a muscular injection of fluoxetine both on needle electromyogram (EMG) "myotonic runs" and on the surface EMG pattern in patients affected by myotonic dystrophy type 1. METHODS Needle EMG recording: We performed needle EMG recordings on the tibialis anterior or opponent thumb muscle in 3 patients. The resting electrical activity and the myotonic discharge were detected before and after the local injection of 100 microL of fluoxetine. Surface EMG recording: A motor point stimulation protocol was carried out on the tibialis anterior of 3 patients. Stimulation consisted of 10-second, 15-Hz pulse train, 0.1 ms in duration. A supramaximal stimulation was applied, and the surface myoelectric signal was recorded. The averaged rectified value (ARV) of the amplitude was evaluated before and after the intramuscular injection of 300 microL of fluoxetine. RESULTS Needle EMG: The injection of fluoxetine induced a clear-cut reduction of the basal electrical activity and made it impossible to evoke "myotonic runs" in all the patients tested. The reversibility of the effect of the drug was checked in 2 patients who exhibited a partial recovery of myotonic EMG activity 40 minutes after the administration. Surface EMG: The patients showed the typical decreasing ARV pattern before the drug administration; the fluoxetine injection consistently provoked a clear and complete recovery of the normal increasing ARV curve. CONCLUSIONS We showed, for the first time, that the local application of fluoxetine produces functional modifications in myotonic dystrophy type 1 muscle electrical properties. The relevance of this study consists in the introduction of fluoxetine, a well-known and largely used drug, as a tool for investigating further therapeutical approaches in this disease.
Collapse
|
45
|
Choi KH, Rhim H. Inhibition of recombinant Ca(v)3.1 (alpha(1G)) T-type calcium channels by the antipsychotic drug clozapine. Eur J Pharmacol 2009; 626:123-30. [PMID: 19782679 DOI: 10.1016/j.ejphar.2009.09.035] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 09/03/2009] [Accepted: 09/14/2009] [Indexed: 12/12/2022]
Abstract
Low voltage-activated T-type calcium channels are involved in the regulation of the neuronal excitability, and could be subject to many antipsychotic drugs. The effects of clozapine, an atypical antipsychotic drug, on recombinant Ca(v)3.1 T-type calcium channels heterologously expressed in human embryonic kidney 293 cells were examined using whole-cell patch-clamp recordings. At a standard holding potential of -100 mV, clozapine inhibited Ca(v)3.1 currents with an IC(50) value of 23.7+/-1.3 microM in a use-dependent manner. However, 10 microM clozapine inhibited more than 50% of the Ca(v)3.1 currents in recordings at a more physiologically relevant holding potential of -75 mV. Clozapine caused a significant hyperpolarizing shift in the steady-state inactivation curve of the Ca(v)3.1 channels, which is presumably the main mechanism accounting for the inhibition of the Ca(v)3.1 currents. In addition, clozapine slowed Ca(v)3.1 deactivation and inactivation kinetics but not activation kinetics. Clozapine-induced changes in deactivation and inactivation rates of the Ca(v)3.1 channel gating would likely facilitate calcium influx via Ca(v)3.1 T-type calcium channels. Thus, clozapine may exert its therapeutic and/or side effects by altering cell's excitability and firing properties through actions on T-type calcium channels.
Collapse
Affiliation(s)
- Kee-Hyun Choi
- Life Sciences Research Division, Korea Institute of Science and Technology, 39-1 Hawolgok-Dong, Seongbuk-Gu, Seoul, 136-791, Republic of Korea
| | | |
Collapse
|
46
|
Lanni C, Govoni S, Lucchelli A, Boselli C. Depression and antidepressants: molecular and cellular aspects. Cell Mol Life Sci 2009; 66:2985-3008. [PMID: 19521663 PMCID: PMC11115917 DOI: 10.1007/s00018-009-0055-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 04/28/2009] [Accepted: 05/20/2009] [Indexed: 01/05/2023]
Abstract
Clinical depression is viewed as a physical and psychic disease process having a neuropathological basis, although a clear understanding of its ethiopathology is still missing. The observation that depressive symptoms are influenced by pharmacological manipulation of monoamines led to the hypothesis that depression results from reduced availability or functional deficiency of monoaminergic transmitters in some cerebral regions. However, there are limitations to current monoamine theories related to mood disorders. Recently, a growing body of experimental data has showed that other classes of endogenous compounds, such as neuropeptides and amino acids, may play a significant role in the pathophysiology of affective disorders. With the development of neuroscience, neuronal networks and intracellular pathways have been identified and characterized, describing the existence of the interaction between monoamines and receptors in turn able to modulate the expression of intracellular proteins and neurotrophic factors, suggesting that depression/antidepressants may be intermingled with neurogenesis/neurodegenerative processes.
Collapse
Affiliation(s)
- Cristina Lanni
- Department of Experimental and Applied Pharmacology, Centre of Excellence in Applied Biology, University of Pavia, Viale Taramelli 14, 27100 Pavia, Italy
| | - Stefano Govoni
- Department of Experimental and Applied Pharmacology, Centre of Excellence in Applied Biology, University of Pavia, Viale Taramelli 14, 27100 Pavia, Italy
| | - Adele Lucchelli
- Department of Experimental and Applied Pharmacology, Centre of Excellence in Applied Biology, University of Pavia, Viale Taramelli 14, 27100 Pavia, Italy
| | - Cinzia Boselli
- Department of Experimental and Applied Pharmacology, Centre of Excellence in Applied Biology, University of Pavia, Viale Taramelli 14, 27100 Pavia, Italy
| |
Collapse
|
47
|
Neuwoehner J, Fenner K, Escher BI. Physiological modes of action of fluoxetine and its human metabolites in algae. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:6830-6837. [PMID: 19764256 DOI: 10.1021/es9005493] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Fluoxetine, the active ingredient of many antidepressants, was identified as specifically toxic toward algae in a quantitative structure-activity relationship (QSAR) analysis with literature data for algae, daphnia, and fish. The goal of this study was to elucidate the mode of action in algae and to evaluate the toxicity of the major human metabolites of fluoxetine using two different algae tests. The time dependence and sensitivity of thedifferenteffectendpointsyield information on the physiological mode of action. Baseline toxicity was predicted with QSARs based on measured liposome-water partition coefficients. The ratio of predicted baseline toxicity to experimental toxicity (toxic ratio TR) gives information on the intrinsic potency (extent of specificity of effect). The metabolite p-trifluoromethylphenol was classified to act as baseline toxicant Fluoxetine (TR 60-150) and its pharmacologically active metabolite norfluoxetine (TR 10-80) exhibited specific toxicity. By comparison with reference compounds we conclude that fluoxetine and norfluoxetine have an effect on the energy budget of algal cells since the time pattern of these two compounds is most similar to that observed for norflurazon, but they act less specifically as indicated by lower TR values and the similarity of the effect pattern to baseline toxicants. The mixture toxicity of fluoxetine and its human metabolites norfluoxetine and p-TFMP can be predicted using the model of concentration addition for practical purposes of risk assessment despite small deviations from this model for the specific endpoints like PSII inhibition because the integrative endpoints like growth rate and reproduction in all cases gave agreement with the predictions for concentration addition.
Collapse
Affiliation(s)
- Judith Neuwoehner
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | | | | |
Collapse
|
48
|
Calcium alters monoamine oxidase-A parameters in human cerebellar and rat glial C6 cell extracts: possible influence by distinct signalling pathways. Life Sci 2009; 85:262-8. [PMID: 19539632 DOI: 10.1016/j.lfs.2009.06.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 05/15/2009] [Accepted: 06/09/2009] [Indexed: 01/24/2023]
Abstract
AIMS Calcium (Ca(2+)) is known to augment monoamine oxidase-A (MAO-A) activity in cell cultures as well as in brain extracts from several species. This association between Ca(2+) and MAO-A could contribute to their respective roles in cytotoxicity. However, the effect of Ca(2+) on MAO-A function in human brain has as yet to be examined as does the contribution of specific signalling cascades. MAIN METHODS We examined the effects of Ca(2+) on MAO-A activity and on [(3)H]Ro 41-1049 binding to MAO-A in human cerebellar extracts, and compared this to its effects on MAO-A activity in glial C6 cells following the targeting of signalling pathways using specific chemical inhibitors. KEY FINDINGS Ca(2+) enhances MAO-A activity as well as the association of [(3)H]Ro 41-1049 to MAO-A in human cerebellar extracts. The screening of neuronal and glial cell cultures reveals that MAO-A activity does not always correlate with the expression of either mao-A mRNA or MAO-A protein. Inhibition of the individual PI3K/Akt, ERK and p38(MAPK) signalling pathways in glial C6 cells all augment basal MAO-A activity. Inhibition of the p38(MAPK) pathway also augments Ca(2+)-sensitive MAO-A activity. We also observe the inverse relation between p38(MAPK) activation and MAO-A function in C6 cultures grown to full confluence. SIGNIFICANCE The Ca(2+)-sensitive component to MAO-A activity is present in human brain and in vitro studies link it to the p38(MAPK) pathway. This means of influencing MAO-A function could explain its role in pathologies as diverse as neurodegeneration and cancers.
Collapse
|
49
|
Nagata K, Imai T, Yamashita T, Tsuda M, Tozaki-Saitoh H, Inoue K. Antidepressants inhibit P2X4 receptor function: a possible involvement in neuropathic pain relief. Mol Pain 2009; 5:20. [PMID: 19389225 PMCID: PMC2680826 DOI: 10.1186/1744-8069-5-20] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Accepted: 04/23/2009] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Neuropathic pain is characterized by pain hypersensitivity to innocuous stimuli (tactile allodynia) that is nearly always resistant to known treatments such as non-steroidal anti-inflammatory drugs or even opioids. It has been reported that some antidepressants are effective for treating neuropathic pain. However, the underlying molecular mechanisms are not well understood. We have recently demonstrated that blocking P2X4 receptors in the spinal cord reverses tactile allodynia after peripheral nerve injury in rats, implying that P2X4 receptors are a key molecule in neuropathic pain. We investigated a possible role of antidepressants as inhibitors of P2X4 receptors and analysed their analgesic mechanism using an animal model of neuropathic pain. RESULTS Antidepressants strongly inhibited ATP-mediated Ca2+ responses in P2X4 receptor-expressing 1321N1 cells, which are known to have no endogenous ATP receptors. Paroxetine exhibited the most powerful inhibition of calcium influx via rat and human P2X4 receptors, with IC50 values of 2.45 microM and 1.87 microM, respectively. Intrathecal administration of paroxetine produced a striking antiallodynic effect in an animal model of neuropathic pain. Co-administration of WAY100635, ketanserin or ondansetron with paroxetine induced no significant change in the antiallodynic effect of paroxetine. Furthermore, the antiallodynic effect of paroxetine was observed even in rats that had received intrathecal pretreatment with 5,7-dihydroxytryptamine, which dramatically depletes spinal 5-hydroxytryptamine. CONCLUSION These results suggest that paroxetine acts as a potent analgesic in the spinal cord via a mechanism independent of its inhibitory effect on serotonin transporters. Powerful inhibition on P2X4 receptors may underlie the analgesic effect of paroxetine, and it is possible that some antidepressants clinically used in patients with neuropathic pain show antiallodynic effects, at least in part via their inhibitory effects on P2X4 receptors.
Collapse
Affiliation(s)
- Kenichiro Nagata
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
| | | | | | | | | | | |
Collapse
|
50
|
Sala M, Lazzaretti M, De Vidovich G, Caverzasi E, Barale F, d'Allio G, Brambilla P. Electrophysiological changes of cardiac function during antidepressant treatment. Ther Adv Cardiovasc Dis 2008; 3:29-43. [PMID: 19124389 DOI: 10.1177/1753944708096282] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Some antidepressant agents can cause electrophysiological changes of cardiac function leading to ventricular arrhythmias and sudden death. However, antidepressants have also protective effects on the heart through their capacity to modulate cardiac autonomic-mediated physiological responses. Heart rate variability and QTc length are two strictly linked parameters that allow us to appreciate the effects of different drugs on cardiac physiology. Heart rate variability reflects functioning of the autonomic nervous system and possibly also regulation by the limbic system. Autonomic regulation of cardiac activity influences also cardiac repolarization and QT length, both directly and via its effects on heart rate. In this review we present the methodologies adopted to study the effect of antidepressant drugs on QT length and heart rate variability and we summarize data on electrophysiological changes related to antidepressant treatment. Clinical implications for the choice of different antidepressants in different clinical populations are discussed.
Collapse
Affiliation(s)
- Michela Sala
- Azienda Sanitaria Locale di Alessandria, Presidio di Casale Monferrato, Department of Mental Health, Italy.
| | | | | | | | | | | | | |
Collapse
|