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Wang YJ, Yeh CJ, Gao ZH, Hwang E, Chen HH, Wu SN. Inhibitory Perturbations of Fluvastatin on Afterhyperpolarization Current, Erg-mediated K + Current, and Hyperpolarization-activated Cation Current in Both Pituitary GH 3 Cells and Primary Embryonic Mouse Cortical Neurons. Neuroscience 2023; 531:12-23. [PMID: 37661016 DOI: 10.1016/j.neuroscience.2023.08.038] [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: 05/18/2023] [Revised: 08/27/2023] [Accepted: 08/29/2023] [Indexed: 09/05/2023]
Abstract
Fluvastatin (FLV), the first synthetically derived 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, is a potent inhibitor of cholesterol biosynthesis. While its primary mechanism of action is to reduce cholesterol levels, there is some evidence suggesting that it may also have effects on K+ channels. However, the overall effects of fluvastatin on ionic currents are not yet well understood. The whole-cell clamp recordings were applied to evaluate the ionic currents and action potentials of cells. Here, we have demonstrated that FLV can effectively inhibit the amplitude of erg-mediated K+ current (IK(erg)) in pituitary tumor (GH3) cells, with an IC50 of approximately 3.2 µM. In the presence of FLV, the midpoint in the activation curve of IK(erg) was distinctly shifted to a less negative potential by 10 mV, with minimal modification of the gating charge. However, the magnitude of hyperpolarization-activated cation current (Ih) elicited by long-lasting membrane hyperpolarization was progressively decreased, with an IC50 value of 8.7 µM, upon exposure to FLV. More interestingly, we also found that FLV (5 µM) could regulate the action potential and afterhyperpolarization properties in primary embryonic mouse cortical neurons. Our study presents compelling evidence indicating that FLV has the potential to impact both the amplitude and gating of the ion channels IK(erg) and Ih. We also provide credible evidence suggesting that this drug has the potential to modify the properties of action potentials and the afterhyperpolarization current in electrically excitable cells. However, the assumption that these findings translate to similar in-vivo results remains unclear.
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Affiliation(s)
- Ya-Jean Wang
- Department of Senior Services Industry Management, Minghsin University of Science and Technology, Hsinchu, Taiwan.
| | - Che-Jui Yeh
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
| | - Zi-Han Gao
- Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan
| | - Eric Hwang
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan; Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan; Institute of Bioinformatics and Systems Biology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
| | - Hwei-Hisen Chen
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan; Institute of Neuroscience, National Chengchi University, Taipei, Taiwan.
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan; Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan, Taiwan; Department of Medical Research and Education, An Nan Hostpial, China Medical University Hospital, China Medical University, Tainan, Taiwan.
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Salinas-Luypaert C, Sáez-Cortez F, Quintanilla ME, Herrera-Marschitz M, Rivera-Meza M. Gene knockdown of HCN2 ion channels in the ventral tegmental area reduces ethanol consumption in alcohol preferring rats. THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 2022; 48:165-175. [PMID: 35377277 DOI: 10.1080/00952990.2022.2033759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/04/2022] [Accepted: 01/15/2022] [Indexed: 06/14/2023]
Abstract
Background: Hyperpolarization-Activated Cyclic Nucleotide-Gated (HCN) ionic channels are known to play a key role in the control of neuron excitability and have been proposed as a molecular target of ethanol. Previous studies in rats have shown that gene-induced overexpression of the HCN2 channel in the ventral tegmental area (VTA) increases the rewarding effects of ethanol and its intake by the animals.Objective: The aim of this work was to study the effects of VTA HCN2 gene knockdown in the voluntary ethanol consumption of alcohol-preferring UChB rats.Methods: Two lentiviral vectors were generated; LV-siRNA-HCN2, coding for a siRNA that elicited >95% reduction of HCN2 protein levels in vitro, and a control vector coding for a scrambled siRNA sequence. Female UChB naïve rats (n = 14) were microinjected into the VTA with LV-siRNA-HCN2 or the scrambled control vector (n = 11). Four days after, animals were given a daily free access to 10% ethanol and water for 10 days.Results: Rats treated with the LV-siRNA-HCN2 vector showed a ~ 70% reduction (p < .001) in their ethanol preference and ethanol intake compared to control animals. No changes were observed in the total fluid intake of both groups. HCN2 levels in the VTA were measured by Western blot showing a reduction of 40% (p < .05) in the rats injected with LV-siRNA-HCN2, compared to control animals.Conclusion: These results show that knockdown of HCN2 ionic channels in the VTA of UChB rats markedly reduces their voluntary ethanol intake, supporting the idea that HCN2 channels may constitute a therapeutic target for alcohol use disorders.
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Affiliation(s)
- Catalina Salinas-Luypaert
- Department of Pharmacological and Toxicological Chemistry, Faculty of Chemical and Pharmaceutical Sciences Santiago, Chile
| | - Felipe Sáez-Cortez
- Program of Molecular and Clinical Pharmacology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - María Elena Quintanilla
- Program of Molecular and Clinical Pharmacology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Mario Herrera-Marschitz
- Program of Molecular and Clinical Pharmacology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Mario Rivera-Meza
- Department of Pharmacological and Toxicological Chemistry, Faculty of Chemical and Pharmaceutical Sciences Santiago, Chile
- Research Center for the Development of Novel Therapeutic Alternatives for Alcohol Use Disorders, Santiago, Chile
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