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Huang X, Choi S, Wu W, Shahi PK, Lee JH, Hong C, Jun JY. 5-Hydroxytryptamine Enhances the Pacemaker Activity of Interstitial Cells of Cajal in Mouse Colon. Int J Mol Sci 2024; 25:3997. [PMID: 38612808 PMCID: PMC11012597 DOI: 10.3390/ijms25073997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/02/2024] [Accepted: 04/02/2024] [Indexed: 04/14/2024] Open
Abstract
We examined the localization of the 5-hydroxytryptamine (5-HT) receptor and its effects on mouse colonic interstitial cells of Cajal (ICCs) using electrophysiological techniques. Treatment with 5-HT increased the pacemaker activity in colonic ICCs with depolarization of membrane potentials in a dose-dependent manner. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channel blockers blocked pacemaker activity and 5-HT-induced effects. Moreover, an adenylate cyclase inhibitor inhibited 5-HT-induced effects, and cell-permeable 8-bromo-cAMP increased the pacemaker activity. Various agonists of the 5-HT receptor subtype were working in colonic ICCs, including the 5-HT4 receptor. In small intestinal ICCs, 5-HT depolarized the membrane potentials transiently. Adenylate cyclase inhibitors or HCN blockers did not show any influence on 5-HT-induced effects. Anoctamin-1 (ANO1) or T-type Ca2+ channel blockers inhibited the pacemaker activity of colonic ICCs and blocked 5-HT-induced effects. A tyrosine protein kinase inhibitor inhibited pacemaker activity in colonic ICCs under controlled conditions but did not show any influence on 5-HT-induced effects. Among mitogen-activated protein kinase (MAPK) inhibitors, a p38 MAPK inhibitor inhibited 5-HT-induced effects on colonic ICCs. Thus, 5-HT's effect on pacemaker activity in small intestinal and colonic ICCs has excitatory but variable patterns. ANO1, T-type Ca2+, and HCN channels are involved in 5-HT-induced effects, and MAPKs are involved in 5-HT effects in colonic ICCs.
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Affiliation(s)
- Xingyou Huang
- Department of Physiology, College of Medicine, Chosun University, Gwangju 61452, Republic of Korea; (X.H.); (S.C.); (W.W.); (P.K.S.); (C.H.)
| | - Seok Choi
- Department of Physiology, College of Medicine, Chosun University, Gwangju 61452, Republic of Korea; (X.H.); (S.C.); (W.W.); (P.K.S.); (C.H.)
| | - Wenhao Wu
- Department of Physiology, College of Medicine, Chosun University, Gwangju 61452, Republic of Korea; (X.H.); (S.C.); (W.W.); (P.K.S.); (C.H.)
| | - Pawan Kumar Shahi
- Department of Physiology, College of Medicine, Chosun University, Gwangju 61452, Republic of Korea; (X.H.); (S.C.); (W.W.); (P.K.S.); (C.H.)
| | - Jun Hyung Lee
- Department of Internal Medicine, College of Medicine, Chosun University, Gwangju 61452, Republic of Korea;
| | - Chansik Hong
- Department of Physiology, College of Medicine, Chosun University, Gwangju 61452, Republic of Korea; (X.H.); (S.C.); (W.W.); (P.K.S.); (C.H.)
| | - Jae Yeoul Jun
- Department of Physiology, College of Medicine, Chosun University, Gwangju 61452, Republic of Korea; (X.H.); (S.C.); (W.W.); (P.K.S.); (C.H.)
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Neumann J, Hofmann B, Dhein S, Gergs U. Glucagon and Its Receptors in the Mammalian Heart. Int J Mol Sci 2023; 24:12829. [PMID: 37629010 PMCID: PMC10454195 DOI: 10.3390/ijms241612829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/25/2023] [Accepted: 08/03/2023] [Indexed: 08/27/2023] Open
Abstract
Glucagon exerts effects on the mammalian heart. These effects include alterations in the force of contraction, beating rate, and changes in the cardiac conduction system axis. The cardiac effects of glucagon vary according to species, region, age, and concomitant disease. Depending on the species and region studied, the contractile effects of glucagon can be robust, modest, or even absent. Glucagon is detected in the mammalian heart and might act with an autocrine or paracrine effect on the cardiac glucagon receptors. The glucagon levels in the blood and glucagon receptor levels in the heart can change with disease or simultaneous drug application. Glucagon might signal via the glucagon receptors but, albeit less potently, glucagon might also signal via glucagon-like-peptide-1-receptors (GLP1-receptors). Glucagon receptors signal in a species- and region-dependent fashion. Small molecules or antibodies act as antagonists to glucagon receptors, which may become an additional treatment option for diabetes mellitus. Hence, a novel review of the role of glucagon and the glucagon receptors in the mammalian heart, with an eye on the mouse and human heart, appears relevant. Mouse hearts are addressed here because they can be easily genetically modified to generate mice that may serve as models for better studying the human glucagon receptor.
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Affiliation(s)
- Joachim Neumann
- Institute for Pharmacology and Toxicology, Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Straße 4, D-06097 Halle (Saale), Germany;
| | - Britt Hofmann
- Department of Cardiac Surgery, Mid-German Heart Center, University Hospital Halle, Ernst Grube Straße 40, D-06097 Halle (Saale), Germany;
| | - Stefan Dhein
- Rudolf-Boehm Institut für Pharmakologie und Toxikologie, Universität Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany;
| | - Ulrich Gergs
- Institute for Pharmacology and Toxicology, Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Straße 4, D-06097 Halle (Saale), Germany;
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Chen CS, So EC, Wu SN. Modulating Hyperpolarization-Activated Cation Currents through Small Molecule Perturbations: Magnitude and Gating Control. Biomedicines 2023; 11:2177. [PMID: 37626674 PMCID: PMC10452073 DOI: 10.3390/biomedicines11082177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/10/2023] [Accepted: 07/27/2023] [Indexed: 08/27/2023] Open
Abstract
The hyperpolarization-activated cation current (Ih) exhibits a slowly activating time course of the current (Ih) when the cell membrane is hyperpolarized for an extended duration. It is involved in generating electrical activity in various excitable cells. Numerous structurally distinct compounds or herbal drugs have the potential to impact both the magnitude and gating kinetics of this current. Brivaracetam, a chemical analog of levetiracetam known to be a ligand for synaptic vesicle protein 2A, could directly suppress the Ih magnitude. Carisbamate, an anticonvulsant agent, not only inhibited the Ih amplitude but also reduced the strength of voltage-dependent hysteresis (Hys(V)) associated with Ih. Cilobradine, similar to ivabradine, inhibited the amplitude of Ih; however, it also suppressed the amplitude of delayed-rectifier K+ currents. Dexmedetomidine, an agonist of α2-adrenergic receptor, exerted a depressant action on Ih in a concentration-dependent fashion. Suppression of Ih amplitude was observed when GAL-021, a breathing control modulator, was present at a concentration exceeding 30 μM. Lutein, one of the few xanthophyll carotenoids, was able to suppress the Ih amplitude as well as to depress Hys(V)'s strength of Ih. Pirfenidone, a pyridine derivative known to be an anti-fibrotic agent, depressed the Ih magnitude in a concentration- and voltage-dependent fashion. Tramadol, a synthetic centrally active analgesic, was shown to reduce the Ih magnitude, independent of its interaction with opioid receptors. Various herbal drugs, including ent-kaurane-type diterpenoids from Croton tonkinensis, Ganoderma triterpenoids, honokiol, and pterostilbene, demonstrated efficacy in reducing the magnitude of Ih. Conversely, oxaliplatin, a platinum-based chemotherapeutic compound, was observed to effectively increase the Ih amplitude. Collectively, the regulatory effects of these compounds or herbal drugs on cellular function can be partly attributed to their perturbations on Ih.
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Affiliation(s)
- Cheng-Shih Chen
- Department of Anesthesia, An Nan Hospital, China Medical University, Tainan 70965, Taiwan; (C.-S.C.); (E.C.S.)
| | - Edmund Cheung So
- Department of Anesthesia, An Nan Hospital, China Medical University, Tainan 70965, Taiwan; (C.-S.C.); (E.C.S.)
| | - Sheng-Nan Wu
- School of Medicine, National Sun Yat Sen University College of Medicine, Kaohsiung 804, Taiwan
- Department of Medical Education & Research, An Nan Hospital, China Medical University, Tainan 70965, Taiwan
- Department of Physiology, National Cheng Kung University Medical College, Tainan 701, Taiwan
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Wu SN, Wu CL, Cho HY, Chiang CW. Effective Perturbations by Small-Molecule Modulators on Voltage-Dependent Hysteresis of Transmembrane Ionic Currents. Int J Mol Sci 2022; 23:ijms23169453. [PMID: 36012718 PMCID: PMC9408818 DOI: 10.3390/ijms23169453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 11/16/2022] Open
Abstract
The non-linear voltage-dependent hysteresis (Hys(V)) of voltage-gated ionic currents can be robustly activated by the isosceles-triangular ramp voltage (Vramp) through digital-to-analog conversion. Perturbations on this Hys(V) behavior play a role in regulating membrane excitability in different excitable cells. A variety of small molecules may influence the strength of Hys(V) in different types of ionic currents elicited by long-lasting triangular Vramp. Pirfenidone, an anti-fibrotic drug, decreased the magnitude of Ih's Hys(V) activated by triangular Vramp, while dexmedetomidine, an agonist of α2-adrenoceptors, effectively suppressed Ih as well as diminished the Hys(V) strength of Ih. Oxaliplatin, a platinum-based anti-neoplastic drug, was noted to enhance the Ih's Hys(V) strength, which is thought to be linked to the occurrence of neuropathic pain, while honokiol, a hydroxylated biphenyl compound, decreased Ih's Hys(V). Cell exposure to lutein, a xanthophyll carotenoid, resulted in a reduction of Ih's Hys(V) magnitude. Moreover, with cell exposure to UCL-2077, SM-102, isoplumbagin, or plumbagin, the Hys(V) strength of erg-mediated K+ current activated by triangular Vramp was effectively diminished, whereas the presence of either remdesivir or QO-58 respectively decreased or increased Hys(V) magnitude of M-type K+ current. Zingerone, a methoxyphenol, was found to attenuate Hys(V) (with low- and high-threshold loops) of L-type Ca2+ current induced by long-lasting triangular Vramp. The Hys(V) properties of persistent Na+ current (INa(P)) evoked by triangular Vramp were characterized by a figure-of-eight (i.e., ∞) configuration with two distinct loops (i.e., low- and high-threshold loops). The presence of either tefluthrin, a pyrethroid insecticide, or t-butyl hydroperoxide, an oxidant, enhanced the Hys(V) strength of INa(P). However, further addition of dapagliflozin can reverse their augmenting effects in the Hys(V) magnitude of the current. Furthermore, the addition of esaxerenone, mirogabalin, or dapagliflozin was effective in inhibiting the strength of INa(P). Taken together, the observed perturbations by these small-molecule modulators on Hys(V) strength in different types of ionic currents evoked during triangular Vramp are expected to influence the functional activities (e.g., electrical behaviors) of different excitable cells in vitro or in vivo.
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Affiliation(s)
- Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Department of Post-Baccalaureate Medicine, National Sun Yat-sen University, Kaohsiung 804201, Taiwan
- Correspondence: ; Tel.: +886-6-2353535 (ext. 5334); Fax: +886-6-2362780
| | - Chao-Liang Wu
- Department of Medical Research, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 60002, Taiwan
| | - Hsin-Yen Cho
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan
| | - Chi-Wu Chiang
- Institute of Molecular Medicine, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan
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Wang Z, Zhong C, Li H. Histone demethylase KDM5B catalyzed H3K4me3 demethylation to promote differentiation of bone marrow mesenchymal stem cells into cardiomyocytes. Mol Biol Rep 2022; 49:7239-7249. [PMID: 35788877 PMCID: PMC9304058 DOI: 10.1007/s11033-022-07428-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 03/24/2022] [Indexed: 11/24/2022]
Abstract
Background Studies have shown that histone H3 methylation is involved in regulating the differentiation of Bone Marrow Mesenchymal Stem Cells (BMSCs). KDM5B can specifically reduce the level of histone 3 lysine 4 trimethylation (H3K4me3), thereby activating the expression of related genes and participating in biological processes such as cell differentiation, embryonic development and tumor formation. Whether KDM5B is involved in the regulation of BMSCs differentiation into cardiomyocytes through the above manner has not been reported. Objective To investigate the effect of KDM5B on the induction and differentiation of swine BMSCs into myocardial cells in vitro. Methods Swine bone marrow BMSCs were isolated and cultured, and the overexpression, interference expression and blank vector of KMD5B were constructed and transfected by lentivirus. BMSCs was induced to differentiate into cardiomyocytes by 5-azacytidine (5-AZA) in vitro, and the differentiation efficiency was compared by immunofluorescence, RT-PCR, Western Blot and whole-cell patch clamp detection. Result Compared with the control group, the expression levels of histone H3K4me3 and pluripotency gene Nanog in KDM5B overexpression group were significantly decreased, while the expression level of key myocardial gene HCN4 and myocardial marker gene α-Actin and cTNT were significantly increased, and the Na+ current density on the surface of differentiated myocardial cell membrane was significantly increased. Meanwhile, the corresponding results of the KDM5B silent expression group were just opposite. Conclusions It indicated that enhanced KDM5B expression could promote the differentiation of BMSCs into cardiomyocytes and improve the differentiation efficiency by controlling H3K4 methylation levels.
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Affiliation(s)
- Zhen Wang
- Medical College of Yangzhou University, Yangzhou, 225001, Jiangsu, China.,Friendliness Hospital Yangzhou, Jiangsu, 225009, China
| | - Chenlu Zhong
- Medical College of Yangzhou University, Yangzhou, 225001, Jiangsu, China.,Department of Cardiology, Northern Jiangsu People's Hospital, Yangzhou, 225001, Jiangsu, China
| | - Hongxiao Li
- Medical College of Yangzhou University, Yangzhou, 225001, Jiangsu, China. .,Department of Cardiology, Northern Jiangsu People's Hospital, Yangzhou, 225001, Jiangsu, China.
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Oniani T, Vinnenberg L, Chaudhary R, Schreiber JA, Riske K, Williams B, Pape HC, White JA, Junker A, Seebohm G, Meuth SG, Hundehege P, Budde T, Zobeiri M. Effects of Axonal Demyelination, Inflammatory Cytokines and Divalent Cation Chelators on Thalamic HCN Channels and Oscillatory Bursting. Int J Mol Sci 2022; 23:ijms23116285. [PMID: 35682964 PMCID: PMC9181513 DOI: 10.3390/ijms23116285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/31/2022] [Accepted: 05/31/2022] [Indexed: 12/13/2022] Open
Abstract
Multiple sclerosis (MS) is a demyelinating disease of the central nervous system that is characterized by the progressive loss of oligodendrocytes and myelin and is associated with thalamic dysfunction. Cuprizone (CPZ)-induced general demyelination in rodents is a valuable model for studying different aspects of MS pathology. CPZ feeding is associated with the altered distribution and expression of different ion channels along neuronal somata and axons. However, it is largely unknown whether the copper chelator CPZ directly influences ion channels. Therefore, we assessed the effects of different divalent cations (copper; zinc) and trace metal chelators (EDTA; Tricine; the water-soluble derivative of CPZ, BiMPi) on hyperpolarization-activated cyclic nucleotide-gated (HCN) channels that are major mediators of thalamic function and pathology. In addition, alterations of HCN channels induced by CPZ treatment and MS-related proinflammatory cytokines (IL-1β; IL-6; INF-α; INF-β) were characterized in C57Bl/6J mice. Thus, the hyperpolarization-activated inward current (Ih) was recorded in thalamocortical (TC) neurons and heterologous expression systems (mHCN2 expressing HEK cells; hHCN4 expressing oocytes). A number of electrophysiological characteristics of Ih (potential of half-maximal activation (V0.5); current density; activation kinetics) were unchanged following the extracellular application of trace metals and divalent cation chelators to native neurons, cell cultures or oocytes. Mice were fed a diet containing 0.2% CPZ for 35 days, resulting in general demyelination in the brain. Withdrawal of CPZ from the diet resulted in rapid remyelination, the effects of which were assessed at three time points after stopping CPZ feeding (Day1, Day7, Day25). In TC neurons, Ih was decreased on Day1 and Day25 and revealed a transient increased availability on Day7. In addition, we challenged naive TC neurons with INF-α and IL-1β. It was found that Ih parameters were differentially altered by the application of the two cytokines to thalamic cells, while IL-1β increased the availability of HCN channels (depolarized V0.5; increased current density) and the excitability of TC neurons (depolarized resting membrane potential (RMP); increased the number of action potentials (APs); produced a larger voltage sag; promoted higher input resistance; increased the number of burst spikes; hyperpolarized the AP threshold), INF-α mediated contrary effects. The effect of cytokine modulation on thalamic bursting was further assessed in horizontal slices and a computational model of slow thalamic oscillations. Here, IL-1β and INF-α increased and reduced oscillatory bursting, respectively. We conclude that HCN channels are not directly modulated by trace metals and divalent cation chelators but are subject to modulation by different MS-related cytokines.
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Affiliation(s)
- Tengiz Oniani
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
| | - Laura Vinnenberg
- Department of Neurology with Institute of Translational Neurology, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany; (L.V.); (P.H.)
| | - Rahul Chaudhary
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
| | - Julian A. Schreiber
- Institute of Pharmaceutical and Medicinal Chemistry, Westfälische Wilhelms-Universität, Corren-Str. 48, D-48149 Münster, Germany;
- Cellular Electrophysiology and Molecular Biology, Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Robert-Koch-Str. 45, D-48149 Münster, Germany;
| | - Kathrin Riske
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms-Universität, Waldeyer-Str. 15, D-48149 Münster, Germany; (K.R.); (A.J.)
| | - Brandon Williams
- Center for Systems Neuroscience, Neurophotonics Center, Department of Biomedical Engineering, Boston University, 610 Commonwealth Ave., Boston, MA 02215, USA; (B.W.); (J.A.W.)
| | - Hans-Christian Pape
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
| | - John A. White
- Center for Systems Neuroscience, Neurophotonics Center, Department of Biomedical Engineering, Boston University, 610 Commonwealth Ave., Boston, MA 02215, USA; (B.W.); (J.A.W.)
| | - Anna Junker
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms-Universität, Waldeyer-Str. 15, D-48149 Münster, Germany; (K.R.); (A.J.)
| | - Guiscard Seebohm
- Cellular Electrophysiology and Molecular Biology, Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Robert-Koch-Str. 45, D-48149 Münster, Germany;
| | - Sven G. Meuth
- Neurology Clinic, University Clinic Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany;
| | - Petra Hundehege
- Department of Neurology with Institute of Translational Neurology, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany; (L.V.); (P.H.)
| | - Thomas Budde
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
- Correspondence:
| | - Mehrnoush Zobeiri
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
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Abstract
Pacemaker cells are the basis of rhythm in the heart. Cardiovascular diseases, and in particular, arrhythmias are a leading cause of hospital admissions and have been implicated as a cause of sudden death. The prevalence of people with arrhythmias will increase in the next years due to an increase in the ageing population and risk factors. The current therapies are limited, have a lot of side effects, and thus, are not ideal. Pacemaker channels, also called hyperpolarizationactivated cyclic nucleotide-gated (HCN) channels, are the molecular correlate of the hyperpolarization- activated current, called Ih (from hyperpolarization) or If (from funny), that contribute crucially to the pacemaker activity in cardiac nodal cells and impulse generation and transmission in neurons. HCN channels have emerged as interesting targets for the development of drugs, in particular, to lower the heart rate. Nonetheless, their pharmacology is still rather poorly explored in comparison to many other voltage-gated ion channels or ligand-gated ion channels. Ivabradine is the first and currently the only clinically approved compound that specifically targets HCN channels. The therapeutic indication of ivabradine is the symptomatic treatment of chronic stable angina pectoris in patients with coronary artery disease with a normal sinus rhythm. Several other pharmacological agents have been shown to exert an effect on heart rate, although this effect is not always desired. This review is focused on the pacemaking process taking place in the heart and summarizes the current knowledge on HCN channels.
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Affiliation(s)
- Anne-Sophie Depuydt
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, PO Box 922, Herestraat 49, 3000Leuven, Belgium
| | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, PO Box 922, Herestraat 49, 3000Leuven, Belgium
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, PO Box 922, Herestraat 49, 3000Leuven, Belgium
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Abstract
Automated patch clamping (APC) has been used for almost two decades to increase the throughput of electrophysiological measurements, especially in preclinical safety screening of drug compounds. Typically, cells are suctioned onto holes in planar surfaces and a stronger subsequent suction allows access to a whole cell configuration for electrical measurement of ion channel activity. The development of optogenetic tools over a wide range of wavelengths (UV to IR) provides powerful tools for improving spatiotemporal control of in vivo and in vitro experiments and is emerging as a powerful means of investigating cell networks (neuronal), single cell transduction, and subcellular pathways.Combining APC and optogenetic tools paves the way for improved investigation and control of cell kinetics and provides the opportunity for collecting robust data for new and exciting applications and therapeutic areas. Here, we present an APC optogenetics capability on the Qube Opto 384 system including experiments on light activated ion channels and photoactivated ligands.
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Affiliation(s)
- Kim Boddum
- Sophion Bioscience A/S, Ballerup, Denmark
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Lu TL, Lu TJ, Wu SN. Effectiveness in Block by Dexmedetomidine of Hyperpolarization-Activated Cation Current, Independent of Its Agonistic Effect on α 2-Adrenergic Receptors. Int J Mol Sci 2020; 21:E9110. [PMID: 33266068 DOI: 10.3390/ijms21239110] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/24/2020] [Accepted: 11/28/2020] [Indexed: 12/25/2022] Open
Abstract
Dexmedetomidine (DEX), a highly selective agonist of α2-adrenergic receptors, has been tailored for sedation without risk of respiratory depression. Our hypothesis is that DEX produces any direct perturbations on ionic currents (e.g., hyperpolarization-activated cation current, Ih). In this study, addition of DEX to pituitary GH3 cells caused a time- and concentration-dependent reduction in the amplitude of Ih with an IC50 value of 1.21 μM and a KD value of 1.97 μM. A hyperpolarizing shift in the activation curve of Ih by 10 mV was observed in the presence of DEX. The voltage-dependent hysteresis of Ih elicited by long-lasting triangular ramp pulse was also dose-dependently reduced during its presence. In continued presence of DEX (1 μM), further addition of OXAL (10 μM) or replacement with high K+ could reverse DEX-mediated inhibition of Ih, while subsequent addition of yohimbine (10 μM) did not attenuate the inhibitory effect on Ih amplitude. The addition of 3 μM DEX mildly suppressed the amplitude of erg-mediated K+ current. Under current-clamp potential recordings, the exposure to DEX could diminish the firing frequency of spontaneous action potentials. In pheochromocytoma PC12 cells, DEX was effective at suppressing Ih together with a slowing in activation time course of the current. Taken together, findings from this study strongly suggest that during cell exposure to DEX used at clinically relevant concentrations, the DEX-mediated block of Ih appears to be direct and would particularly be one of the ionic mechanisms underlying reduced membrane excitability in the in vivo endocrine or neuroendocrine cells.
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Chan MH, Chen HH, Lo YC, Wu SN. Effectiveness in the Block by Honokiol, a Dimerized Allylphenol from Magnolia Officinalis, of Hyperpolarization-Activated Cation Current and Delayed-Rectifier K + Current. Int J Mol Sci 2020; 21:ijms21124260. [PMID: 32549398 PMCID: PMC7352210 DOI: 10.3390/ijms21124260] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/03/2020] [Accepted: 06/09/2020] [Indexed: 12/22/2022] Open
Abstract
Background: Honokiol (HNK), a dimer of allylphenol obtained from the bark of Magnolia officinalis was demonstrated to exert an array of biological actions in different excitable cell types. However, whether or how this compound can lead to any perturbations on surface-membrane ionic currents remains largely unknown. Methods: We used the patch clamp method and found that addition of HNK effectively depressed the density of macroscopic hyperpolarization-activated cation currents (Ih) in pituitary GH3 cells in a concentration-, time- and voltage-dependent manner. By the use of a two-step voltage protocol, the presence of HNK (10 μM) shifted the steady-state activation curve of Ih density along the voltage axis to a more negative potential by approximately 11 mV, together with no noteworthy modification in the gating charge of the current. Results: The voltage-dependent hysteresis of Ih density elicited by long-lasting triangular ramp pulse was attenuated by the presence of HNK. The HNK addition also diminished the magnitude of deactivating Ih density elicited by ramp-up depolarization with varying durations. The effective half-maximal concentration (IC50) value needed to inhibit the density of Ih or delayed rectifier K+ current identified in GH3 cells was estimated to be 2.1 or 6.8 μM, respectively. In cell-attached current recordings, HNK decreased the frequency of spontaneous action currents. In Rolf B1.T olfactory sensory neurons, HNK was also observed to decrease Ih density in a concentration-dependent manner. Conclusions: The present study highlights the evidence revealing that HNK has the propensity to perturb these ionic currents and that the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel is proposed to be a potential target for the in vivo actions of HNK and its structurally similar compounds.
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Affiliation(s)
- Ming-Huan Chan
- Institute of Neuroscience, National Chengchi University, Taipei 11605, Taiwan; (M.-H.C.); (H.-H.C.)
| | - Hwei-Hsien Chen
- Institute of Neuroscience, National Chengchi University, Taipei 11605, Taiwan; (M.-H.C.); (H.-H.C.)
- Center of Neuropsychiatric Research, National Health Research Institutes, Miaoli County 35053, Taiwan
| | - Yi-Ching Lo
- Department of Pharmacology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan
- Correspondence:
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11
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Rivolta I, Binda A, Masi A, DiFrancesco JC. Cardiac and neuronal HCN channelopathies. Pflugers Arch 2020; 472:931-951. [PMID: 32424620 DOI: 10.1007/s00424-020-02384-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 12/31/2022]
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are expressed as four different isoforms (HCN1-4) in the heart and in the central and peripheral nervous systems. In the voltage range of activation, HCN channels carry an inward current mediated by Na+ and K+, termed If in the heart and Ih in neurons. Altered function of HCN channels, mainly HCN4, is associated with sinus node dysfunction and other arrhythmias such as atrial fibrillation, ventricular tachycardia, and atrioventricular block. In recent years, several data have also shown that dysfunctional HCN channels, in particular HCN1, but also HCN2 and HCN4, can play a pathogenic role in epilepsy; these include experimental data from animal models, and data collected over genetic mutations of the channels identified and characterized in epileptic patients. In the central nervous system, alteration of the Ih current could predispose to the development of neurodegenerative diseases such as Parkinson's disease; since HCN channels are widely expressed in the peripheral nervous system, their dysfunctional behavior could also be associated with the pathogenesis of neuropathic pain. Given the fundamental role played by the HCN channels in the regulation of the discharge activity of cardiac and neuronal cells, the modulation of their function for therapeutic purposes is under study since it could be useful in various pathological conditions. Here we review the present knowledge of the HCN-related channelopathies in cardiac and neurological diseases, including clinical, genetic, therapeutic, and physiopathological aspects.
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Affiliation(s)
- Ilaria Rivolta
- School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy
| | - Anna Binda
- School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy
| | - Alessio Masi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Jacopo C DiFrancesco
- School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy. .,Department of Neurology, ASST San Gerardo Hospital, University of Milano-Bicocca, Via Pergolesi, 33, 20900, Monza, MB, Italy.
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Lu TL, Lu TJ, Wu SN. Inhibitory Effective Perturbations of Cilobradine (DK-AH269), A Blocker of HCN Channels, on the Amplitude and Gating of Both Hyperpolarization-Activated Cation and Delayed-Rectifier Potassium Currents. Int J Mol Sci 2020; 21:ijms21072416. [PMID: 32244431 PMCID: PMC7177279 DOI: 10.3390/ijms21072416] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/17/2020] [Accepted: 03/28/2020] [Indexed: 12/19/2022] Open
Abstract
Cilobradine (CIL, DK-AH269), an inhibitor of hyperpolarization-activated cation current (Ih), has been observed to possess pro-arrhythmic properties. Whether and how CIL is capable of perturbing different types of membrane ionic currents existing in electrically excitable cells, however, is incompletely understood. In this study, we intended to examine possible modifications by it or other structurally similar compounds of ionic currents in pituitary tumor (GH3) cells and in heart-derived H9c2 cells. The standard whole-cell voltage-clamp technique was performed to examine the effect of CIL on ionic currents. GH3-cell exposure to CIL suppressed the density of hyperpolarization-evoked Ih in a concentration-dependent manner with an effective IC50 of 3.38 μM. Apart from its increase in the activation time constant of Ih during long-lasting hyperpolarization, the presence of CIL (3 μM) distinctly shifted the steady-state activation curve of Ih triggered by a 2-s conditioning pulse to a hyperpolarizing direction by 10 mV. As the impedance-frequency relation of Ih was studied, its presence raised the impedance magnitude at the resonance frequency induced by chirp voltage. CIL also suppressed delayed-rectifier K+ current (IK(DR)) followed by the accelerated inactivation time course of this current, with effective IC50 (measured at late IK(DR)) or KD value of 3.54 or 3.77 μM, respectively. As the CIL concentration increased 1 to 3 μM, the inactivation curve of IK(DR) elicited by 1- or 10-s conditioning pulses was shifted to a hyperpolarizing potential by approximately 10 mV, and the recovery of IK(DR) inactivation during its presence was prolonged. The peak Na+ current (INa) during brief depolarization was resistant to being sensitive to the presence of CIL, yet to be either decreased by subsequent addition of A-803467 or enhanced by that of tefluthrin. In cardiac H9c2 cells, unlike the CIL effect, the addition of either ivabradine or zatebradine mildly led to a lowering in IK(DR) amplitude with no conceivable change in the inactivation time course of the current. Taken together, the compound like CIL, which was tailored to block hyperpolarization-activated cation (HCN) channels effectively, was also capable of altering the amplitude and gating of IK(DR), thereby influencing the functional activities of electrically excitable cells, such as GH3 cells.
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Affiliation(s)
- Te-Ling Lu
- School of Pharmacy, China Medical University, Taichung 40402, Taiwan;
| | - Te-Jung Lu
- Department of Medical Laboratory Science and Biotechnology, Chung Hwa University of Medical Technology, Tainan 71703, Taiwan;
| | - Sheng-Nan Wu
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan
- Correspondence:
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Kuo PC, Liu YC, Lo YC, Wu SN. Characterization of Inhibitory Effectiveness in Hyperpolarization-Activated Cation Currents by a Group of ent-Kaurane-Type Diterpenoids from Croton tonkinensis. Int J Mol Sci 2020; 21:E1268. [PMID: 32070065 DOI: 10.3390/ijms21041268] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/07/2020] [Accepted: 02/09/2020] [Indexed: 12/24/2022] Open
Abstract
Croton is an extensive flowering plant genus in the spurge family, Euphorbiaceae. Three croton compounds with the common ent-kaurane skeleton have been purified from Croton tonkinensis. Methods: We examined any modifications of croton components (i.e., croton-01 [ent-18-acetoxy-7α-hydroxykaur-16-en-15-one], croton-02 [ent-7α,14β-dihydroxykaur-16-en-15-one] and croton-03 [ent-1β-acetoxy-7α,14β-dihydroxykaur-16-en-15-one] on either hyperpolarization-activated cation current (Ih) or erg-mediated K+ current identified in pituitary tumor (GH3) cells and in rat insulin-secreting (INS-1) cells via patch-clamp methods. Results: Addition of croton-01, croton-02, or croton-03 effectively and differentially depressed Ih amplitude. Croton-03 (3 μM) shifted the activation curve of Ih to a more negative potential by approximately 11 mV. The voltage-dependent hysteresis of Ih was also diminished by croton-03 administration. Croton-03-induced depression of Ih could not be attenuated by SQ-22536 (10 μM), an inhibitor of adenylate cyclase, but indeed reversed by oxaliplatin (10 μM). The Ih in INS-1 cells was also depressed effectively by croton-03. Conclusion: Our study highlights the evidence that these ent-kaurane diterpenoids might conceivably perturb these ionic currents through which they have high influence on the functional activities of endocrine or neuroendocrine cells.
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Chang WT, Gao ZH, Li SW, Liu PY, Lo YC, Wu SN. Characterization in Dual Activation by Oxaliplatin, a Platinum-Based Chemotherapeutic Agent of Hyperpolarization-Activated Cation and Electroporation-Induced Currents. Int J Mol Sci 2020; 21:ijms21020396. [PMID: 31936301 PMCID: PMC7014111 DOI: 10.3390/ijms21020396] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 12/30/2019] [Accepted: 01/04/2020] [Indexed: 12/17/2022] Open
Abstract
Oxaliplatin (OXAL) is regarded as a platinum-based anti-neoplastic agent. However, its perturbations on membrane ionic currents in neurons and neuroendocrine or endocrine cells are largely unclear, though peripheral neuropathy has been noted during its long-term administration. In this study, we investigated how the presence of OXAL and other related compounds can interact with two types of inward currents; namely, hyperpolarization-activated cation current (Ih) and membrane electroporation-induced current (IMEP). OXAL increased the amplitude or activation rate constant of Ih in a concentration-dependent manner with effective EC50 or KD values of 3.2 or 6.4 μM, respectively, in pituitary GH3 cells. The stimulation by this agent of Ih could be attenuated by subsequent addition of ivabradine, protopine, or dexmedetomidine. Cell exposure to OXAL (3 μM) resulted in an approximately 11 mV rightward shift in Ih activation along the voltage axis with minimal changes in the gating charge of the curve. The exposure to OXAL also effected an elevation in area of the voltage-dependent hysteresis elicited by long-lasting triangular ramp. Additionally, its application resulted in an increase in the amplitude of IMEP elicited by large hyperpolarization in GH3 cells with an EC50 value of 1.3 μM. However, in the continued presence of OXAL, further addition of ivabradine, protopine, or dexmedetomidine always resulted in failure to attenuate the OXAL-induced increase of IMEP amplitude effectively. Averaged current-voltage relation of membrane electroporation-induced current (IMEP) was altered in the presence of OXAL. In pituitary R1220 cells, OXAL-stimulated Ih remained effective. In Rolf B1.T olfactory sensory neurons, this agent was also observed to increase IMEP in a concentration-dependent manner. In light of the findings from this study, OXAL-mediated increases of Ih and IMEP may coincide and then synergistically act to increase the amplitude of inward currents, raising the membrane excitability of electrically excitable cells, if similar in vivo findings occur.
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Affiliation(s)
- Wei-Ting Chang
- Division of Cardiovascular Medicine, Chi-Mei Medical Center, Tainan 71004, Taiwan;
- Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan 71004, Taiwan
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan;
| | - Zi-Han Gao
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan; (Z.-H.G.); (S.-W.L.)
| | - Shih-Wei Li
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan; (Z.-H.G.); (S.-W.L.)
| | - Ping-Yen Liu
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan;
- Division of Cardiovascular Medicine, Internal Medicine, College of Medicine, National Cheng Kung University Hospital, Tainan 70401, Taiwan
| | - Yi-Ching Lo
- Department of Pharmacology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan; (Z.-H.G.); (S.-W.L.)
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan
- Correspondence:
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So EC, Gao ZH, Ko SY, Wu SN. Characterization of Effectiveness in Concerted Ih Inhibition and IK(Ca) Stimulation by Pterostilbene (Trans-3,5-dimethoxy-4'-hydroxystilbene), a Stilbenoid. Int J Mol Sci 2020; 21:E357. [PMID: 31948124 DOI: 10.3390/ijms21010357] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 12/31/2019] [Accepted: 01/02/2020] [Indexed: 12/13/2022] Open
Abstract
Pterostilbene (PTER), a natural dimethylated analog of resveratrol, has been demonstrated to produce anti-neoplastic or neuroprotective actions. However, how and whether this compound can entail any perturbations on ionic currents in electrically excitable cells remains unknown. In whole-cell current recordings, addition of PTER decreased the amplitude of macroscopic Ih during long-lasting hyperpolarization in GH3 cells in a concentration-dependent manner, with an effective IC50 value of 0.84 μM. Its presence also shifted the activation curve of Ih along the voltage axis to a more hyperpolarized potential, by 11 mV. PTER at a concentration greater than 10 μM could also suppress l-type Ca2+ and transient outward K+ currents in GH3 cells. With the addition of PTER, IK(Ca) amplitude was increased, with an EC50 value of 2.23 μM. This increase in IK(Ca) amplitude was attenuated by further addition of verruculogen, but not by tolbutamide or TRAM-39. Neither atropine nor nicotine, in the continued presence of PTER, modified the PTER-stimulated IK(Ca). PTER (10 μM) slightly suppressed the amplitude of l-type Ca2+ current and transient outward K+ current. The presence of PTER (3 μM) was also effective at increasing the open-state probability of large-conductance Ca2+-activated K+ (BKCa) channels identified in hippocampal mHippoE-14 neurons; however, its inability to alter single-channel conductance was detected. Our study highlights evidence to show that PTER has the propensity to perturb ionic currents (e.g., Ih and IK(Ca)), thereby influencing the functional activities of neurons, and neuroendocrine or endocrine cells.
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Chang WT, Gao ZH, Lo YC, Wu SN. Evidence for Effective Inhibitory Actions on Hyperpolarization-Activated Cation Current Caused by Ganoderma Triterpenoids, the Main Active Constitutents of Ganoderma Spores. Molecules 2019; 24:molecules24234256. [PMID: 31766737 PMCID: PMC6930560 DOI: 10.3390/molecules24234256] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/14/2019] [Accepted: 11/20/2019] [Indexed: 01/05/2023] Open
Abstract
The triterpenoid fraction of Ganoderma (Ganoderma triterpenoids, GTs) has been increasingly demonstrated to provide effective antioxidant, neuroprotective or cardioprotective activities. However, whether GTs is capable of perturbing the transmembrane ionic currents existing in electrically excitable cells is not thoroughly investigated. In this study, an attempt was made to study whether GTs could modify hyperpolarization-activated cation currents (Ih) in pituitary tumor (GH3) cells and in HL-1 atrial cardiomyocytes. In whole-cell current recordings, the addition of GTs produced a dose-dependent reduction in the amplitude of Ih in GH3 cells with an IC50 value of 11.7 µg/mL, in combination with a lengthening in activation time constant of the current. GTs (10 µg/mL) also caused a conceivable shift in the steady-state activation curve of Ih along the voltage axis to a more negative potential by approximately 11 mV. Subsequent addition of neither 8-cyclopentyl-1,3-dipropylxanthine nor 8-(p-sulfophenyl)theophylline, still in the presence of GTs, could attenuate GTs-mediated inhibition of Ih. In current-clamp voltage recordings, GTs diminished the firing frequency of spontaneous action potentials in GH3 cells, and it also decreased the amplitude of sag potential in response to hyperpolarizing current stimuli. In murine HL-1 cardiomyocytes, the GTs addition also suppressed the amplitude of Ih effectively. In DPCPX (1 µM)-treated HL-1 cells, the inhibitory effect of GTs on Ih remained efficacious. Collectively, the inhibition of Ih caused by GTs is independent of its possible binding to adenosine receptors and it might have profound influence in electrical behaviors of different types of electrically excitable cells (e.g., pituitary and heart cells) if similar in vitro or in vivo findings occur.
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Affiliation(s)
- Wei-Ting Chang
- Division of Cardiovascular Medicine, Chi-Mei Medical Center, Tainan 71004, Taiwan;
- Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan 71004, Taiwan
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan
| | - Zi-Han Gao
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan;
| | - Yi-Ching Lo
- Department of Pharmacology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan;
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan
- Correspondence: ; Tel.: +88-662-353-535-5334; Fax: +88-662-362-780
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Román-Anguiano NG, Correa F, Cano-Martínez A, de la Peña-Díaz A, Zazueta C. Cardioprotective effects of Prolame and SNAP are related with nitric oxide production and with diminution of caspases and calpain-1 activities in reperfused rat hearts. PeerJ 2019; 7:e7348. [PMID: 31392096 PMCID: PMC6673759 DOI: 10.7717/peerj.7348] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 06/25/2019] [Indexed: 01/26/2023] Open
Abstract
Cardiac tissue undergoes changes during ischemia-reperfusion (I-R) that compromise its normal function. Cell death is one of the consequences of such damage, as well as diminution in nitric oxide (NO) content. This signaling molecule regulates the function of the cardiovascular system through dependent and independent effects of cyclic guanosine monophosphate (cGMP). The independent cGMP pathway involves post-translational modification of proteins by S-nitrosylation. Studies in vitro have shown that NO inhibits the activity of caspases and calpains through S-nitrosylation of a cysteine located in their catalytic site, so we propose to elucidate if the regulatory mechanisms of NO are related with changes in S-nitrosylation of cell death proteins in the ischemic-reperfused myocardium. We used two compounds that increase the levels of NO by different mechanisms: Prolame, an amino-estrogenic compound with antiplatelet and anticoagulant effects that induces the increase of NO levels in vivo by activating the endothelial nitric oxide synthase (eNOS) and that has not been tested as a potential inhibitor of apoptosis. On the other hand, S-Nitroso-N-acetylpenicillamine (SNAP), a synthetic NO donor that has been shown to decrease cell death after inducing hypoxia-reoxygenation in cell cultures. Main experimental groups were Control, I-R, I-R+Prolame and I-R+SNAP. Additional groups were used to evaluate the NO action pathways. Contractile function represented as heart rate and ventricular pressure was evaluated in a Langendorff system. Infarct size was measured with 2,3,5-triphenyltetrazolium chloride stain. NO content was determined indirectly by measuring nitrite levels with the Griess reaction and cGMP content was measured by Enzyme-Linked ImmunoSorbent Assay. DNA integrity was evaluated by DNA laddering visualized on an agarose gel and by Terminal deoxynucleotidyl transferase dUTP Nick-End Labeling assay. Activities of caspase-3, caspase-8, caspase-9 and calpain-1 were evaluated spectrophotometrically and the content of caspase-3 and calpain-1 by western blot. S-nitrosylation of caspase-3 and calpain-1 was evaluated by labeling S-nitrosylated cysteines. Our results show that both Prolame and SNAP increased NO content and improved functional recovery in post-ischemic hearts. cGMP-dependent and S-nitrosylation pathways were activated in both groups, but the cGMP-independent pathway was preferentially activated by SNAP, which induced higher levels of NO than Prolame. Although SNAP effectively diminished the activity of all the proteases, a correlative link between the activity of these proteases and S-nitrosylation was not fully established.
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Affiliation(s)
| | - Francisco Correa
- Departamento de Biomedicina Cardiovascular, Instituto Nacional de Cardiologia Ignacio Chávez, México, México
| | - Agustina Cano-Martínez
- Departamento de Fisiología, Instituto Nacional de Cardiologia Ignacio Chávez, México, México
| | - Aurora de la Peña-Díaz
- Departamento de Biología Molecular, Instituto Nacional de Cardiologia Ignacio Chávez, México, México.,Departamento de Farmacología, Universidad Nacional Autónoma de México, México, Mexico
| | - Cecilia Zazueta
- Departamento de Biomedicina Cardiovascular, Instituto Nacional de Cardiologia Ignacio Chávez, México, México
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