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Yuntao F, Jinjun L, Hua Fen L, Huiyu C, Dishiwen L, Zhen C, Wang Y, Wang X, Ke Y, Yanni C, Kexin G, Zhibin P, Mei Y, Zhao Q. Atrial fibroblast-derived exosomal miR-21 upregulate myocardial KCa3.1 via the PI3K-Akt pathway during rapid pacing. Heliyon 2024; 10:e33059. [PMID: 39040331 PMCID: PMC11260968 DOI: 10.1016/j.heliyon.2024.e33059] [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: 03/03/2024] [Revised: 06/11/2024] [Accepted: 06/13/2024] [Indexed: 07/24/2024] Open
Abstract
Background Fibroblast-derived exosomes can regulate the electrical remodeling of cardiomyocytes, and the intermediate-conductance calcium-activated potassium channel (KCa3.1) is important in atrial electrical remodeling. However, the underlying molecular mechanisms remain unclear. This study aimed to investigate the regulation of cardiac electrophysiology by exosomes linked to KCa3.1. Methods Atrial myocytes (AMs) and atrial fibroblasts were isolated from Sprague-Dawley suckling rats and cultured individually. The cellular atrial fibrillation (AF) model was established via electrical stimulation (1.0 v/cm, 10 Hz), and fibroblast-derived exosomes were isolated via ultracentrifugation. Exosomes were co-cultured with AMs to investigate their influences on KCa3.1 and the underlying mechanisms. Nanoparticle tracking analysis and transmission electron microscopy were used to measure exosome particle sizes and concentrations. Whole-cell patch clamp was applied to record the current density of KCa3.1 and action potential duration (APD). The expression of miR-21-5p was detected by reverse-transcription polymerase chain reaction (RT-PCR). Western blotting or immunofluorescence was used to measure the expression of exosomal markers, Akt phosphorylation, and KCa3.1. Results Rapid pacing promoted the secretion of exosomes from atrial fibroblasts and miR-21-5p expression in atrial fibroblasts and exosomes. KCa3.1 protein expression and current density significantly increased, and APD50 and APD90 were sharply shortened after rapid pacing in AMs. TRAM-34 (KCa3.1 blocker) extended APD and reduced susceptibility to AF. KCa3.1 and P-AKT expressions were amplified after co-culturing AMs with exosomes secreted by atrial fibroblasts. In contrast, the increase in KCa3.1 expression was reversed after the cells were co-cultured with exosomes secreted by atrial fibroblasts that were transfected with miR-21-5p inhibitors or after the use of LY294002, a PI3K/Akt pathway inhibitor. Conclusions Rapid pacing promoted the secretion of exosomes from fibroblasts, and miR-21-5p was upregulated in exosomes. Moreover, the miR-21-5p-enriched exosomes upregulated KCa3.1 expression in AMs via the PI3K/Akt pathway.
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Affiliation(s)
- Fu Yuntao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Liang Jinjun
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Liu Hua Fen
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Chen Huiyu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Liu Dishiwen
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Cao Zhen
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Youcheng Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Xuewen Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Yuanjia Ke
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Cheng Yanni
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Guo Kexin
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | | | - Yang Mei
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Qingyan Zhao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
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Burg S, Levi O, Elyagon S, Shapiro S, Murninkas M, Etzion S, Gradwohl G, Makarovsky D, Lichtenstein A, Gordon Y, Attali B, Etzion Y. The SK4 channel allosteric blocker, BA6b9, reduces atrial fibrillation substrate in rats with reduced ejection fraction. PNAS NEXUS 2024; 3:pgae192. [PMID: 38783894 PMCID: PMC11114471 DOI: 10.1093/pnasnexus/pgae192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 04/30/2024] [Indexed: 05/25/2024]
Abstract
Atrial fibrillation (AF), the most common cardiac arrhythmia, is strongly associated with several comorbidities including heart failure (HF). AF in general, and specifically in the context of HF, is progressive in nature and associated with poor clinical outcomes. Current therapies for AF are limited in number and efficacy and do not target the underlying causes of atrial remodeling such as inflammation or fibrosis. We previously identified the calcium-activated SK4 K+ channels, which are preferentially expressed in the atria relative to the ventricles in both rat and human hearts, as attractive druggable target for AF treatment. Here, we examined the ability of BA6b9, a novel allosteric inhibitor of SK4 channels that targets the specific calmodulin-PIP2 binding domain, to alter AF susceptibility and atrial remodeling in a systolic HF rat postmyocardial infarction (post-MI) model. Daily BA6b9 injection (20 mg/kg/day) for 3 weeks starting 1-week post-MI prolonged the atrial effective refractory period, reduced AF induction and duration, and dramatically prevented atrial structural remodeling. In the post-MI left atrium (LA), pronounced upregulation of the SK4 K+ channel was observed, with corresponding increases in collagen deposition, α-SMA levels, and NLRP3 inflammasome expression. Strikingly, BA6b9 treatment reversed these changes while also significantly reducing the lateralization of the atrial connexin Cx43 in the LA of post-MI rats. Our findings indicate that the blockade of SK4 K+ channels using BA6b9 not only favors rhythm control but also remarkably reduces atrial structural remodeling, a property that is highly desirable for novel AF therapies, particularly in patients with comorbid HF.
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Affiliation(s)
- Shira Burg
- Department of Physiology & Pharmacology, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Or Levi
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Regenerative Medicine & Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Sigal Elyagon
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Regenerative Medicine & Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Shir Shapiro
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Regenerative Medicine & Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Michael Murninkas
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Regenerative Medicine & Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Sharon Etzion
- Regenerative Medicine & Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Gideon Gradwohl
- Medical Engineering Unit, The Jerusalem College of Technology, Jerusalem 9116001, Israel
| | - Daria Makarovsky
- Inter-Departmental Core Facility, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Alexandra Lichtenstein
- Inter-Departmental Core Facility, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yaara Gordon
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Bernard Attali
- Department of Physiology & Pharmacology, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yoram Etzion
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Regenerative Medicine & Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
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Segura É, Zhao J, Broszczak M, Audet F, Sauvé R, Parent L. Investigating the Impact of Electrostatic Interactions on Calmodulin Binding and Ca 2+-Dependent Activation of the Calcium-Gated Potassium SK4 Channel. Int J Mol Sci 2024; 25:4255. [PMID: 38673845 PMCID: PMC11050286 DOI: 10.3390/ijms25084255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/03/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024] Open
Abstract
Ca2+ binding to the ubiquitous Ca2+ sensing protein calmodulin (CaM) activates the intermediate conductance Ca2+-activated SK4 channel. Potential hydrophilic pockets for CaM binding have been identified at the intracellular HA and HB helices in the C-terminal of SK4 from the three published cryo-EM structures of SK4. Single charge reversal substitutions at either site, significantly weakened the pull-down of SK4 by CaM wild-type (CaM), and decreased the TRAM-34 sensitive outward K+ current densities in native HEK293T cells when compared with SK4 WT measured under the same conditions. Only the doubly substituted SK4 R352D/R355D (HB helix) obliterated the CaM-mediated pull-down and thwarted outward K+ currents. However, overexpression of CaM E84K/E87K, which had been predicted to face the arginine doublet, restored the CaM-mediated pull-down of SK4 R352D/R355D and normalized its whole-cell current density. Virtual analysis of the putative salt bridges supports a unique role for the positively charged arginine doublet at the HB helix into anchoring the interaction with the negatively charged CaM glutamate 84 and 87 CaM. Our findings underscore the unique contribution of electrostatic interactions in carrying CaM binding onto SK4 and support the role of the C-terminal HB helix to the Ca2+-dependent gating process.
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Affiliation(s)
- Émilie Segura
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Centre de Recherche de l’Institut de Cardiologie de Montréal, Université de Montréal, Montréal, QC H1T 1C8, Canada; (É.S.); (F.A.)
| | - Juan Zhao
- Centre de Recherche de l’Institut de Cardiologie de Montréal, Université de Montréal, Montréal, QC H1T 1C8, Canada; (J.Z.); (M.B.)
| | - Marlena Broszczak
- Centre de Recherche de l’Institut de Cardiologie de Montréal, Université de Montréal, Montréal, QC H1T 1C8, Canada; (J.Z.); (M.B.)
| | - Frédéric Audet
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Centre de Recherche de l’Institut de Cardiologie de Montréal, Université de Montréal, Montréal, QC H1T 1C8, Canada; (É.S.); (F.A.)
| | - Rémy Sauvé
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, 2900 Bd Édouard-Montpetit, Montréal, QC H3T 1J4, Canada;
| | - Lucie Parent
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Centre de Recherche de l’Institut de Cardiologie de Montréal, Université de Montréal, Montréal, QC H1T 1C8, Canada; (É.S.); (F.A.)
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Cozzolino M, Panyi G. Intracellular acidity impedes KCa3.1 activation by Riluzole and SKA-31. Front Pharmacol 2024; 15:1380655. [PMID: 38638868 PMCID: PMC11024243 DOI: 10.3389/fphar.2024.1380655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 03/05/2024] [Indexed: 04/20/2024] Open
Abstract
Background The unique microenvironment in tumors inhibits the normal functioning of tumor-infiltrating lymphocytes, leading to immune evasion and cancer progression. Over-activation of KCa3.1 using positive modulators has been proposed to rescue the anti-tumor response. One of the key characteristics of the tumor microenvironment is extracellular acidity. Herein, we analyzed how intra- and extracellular pH affects K+ currents through KCa3.1 and if the potency of two of its positive modulators, Riluzole and SKA-31, is pH sensitive. Methods Whole-cell patch-clamp was used to measure KCa3.1 currents either in activated human peripheral lymphocytes or in CHO cells transiently transfected with either the H192A mutant or wild-type hKCa3.1 in combination with T79D-Calmodulin, or with KCa2.2. Results We found that changes in the intra- and extracellular pH minimally influenced the KCa3.1-mediated K+ current. Extracellular pH, in the range of 6.0-8.0, does not interfere with the capacity of Riluzole and SKA-31 to robustly activate the K+ currents through KCa3.1. Contrariwise, an acidic intracellular solution causes a slow, but irreversible loss of potency of both the activators. Using different protocols of perfusion and depolarization we demonstrated that the loss of potency is strictly time and pH-dependent and that this peculiar effect can be observed with a structurally similar channel KCa2.2. While two different point mutations of both KCa3.1 (H192A) and its associated protein Calmodulin (T79D) do not limit the effect of acidity, increasing the cytosolic Ca2+ concentration to saturating levels eliminated the loss-of-potency phenotype. Conclusion Based on our data we conclude that KCa3.1 currents are not sensitive the either the intracellular or the extracellular pH in the physiological and pathophysiological range. However, intracellular acidosis in T cells residing in the tumor microenvironment could hinder the potentiating effect of KCa3.1 positive modulators administered to boost their activity. Further research is warranted both to clarify the molecular interactions between the modulators and KCa3.1 at different intracellular pH conditions and to define whether this loss of potency can be observed in cancer models as well.
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Affiliation(s)
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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Zuccolini P, Barbieri R, Sbrana F, Picco C, Gavazzo P, Pusch M. IK Channel-Independent Effects of Clotrimazole and Senicapoc on Cancer Cells Viability and Migration. Int J Mol Sci 2023; 24:16285. [PMID: 38003471 PMCID: PMC10671816 DOI: 10.3390/ijms242216285] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 11/10/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023] Open
Abstract
Many studies highlighted the importance of the IK channel for the proliferation and the migration of different types of cancer cells, showing how IK blockers could slow down cancer growth. Based on these data, we wanted to characterize the effects of IK blockers on melanoma metastatic cells and to understand if such effects were exclusively IK-dependent. For this purpose, we employed two different blockers, namely clotrimazole and senicapoc, and two cell lines: metastatic melanoma WM266-4 and pancreatic cancer Panc-1, which is reported to have little or no IK expression. Clotrimazole and senicapoc induced a decrease in viability and the migration of both WM266-4 and Panc-1 cells irrespective of IK expression levels. Patch-clamp experiments on WM266-4 cells revealed Ca2+-dependent, IK-like, clotrimazole- and senicapoc-sensitive currents, which could not be detected in Panc-1 cells. Neither clotrimazole nor senicapoc altered the intracellular Ca2+ concentration. These results suggest that the effects of IK blockers on cancer cells are not strictly dependent on a robust presence of the channel in the plasma membrane, but they might be due to off-target effects on other cellular targets or to the blockade of IK channels localized in intracellular organelles.
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Affiliation(s)
| | | | | | | | | | - Michael Pusch
- Biophysics Institute, National Research Council, 16149 Genova, Italy; (P.Z.); (R.B.); (F.S.); (C.P.); (P.G.)
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Zhu K, Yan T, Qin C, Pan Y, Li J, Lai H, Xu D, Wang C, Hu N. Three-Dimensional Cardiomyocyte-Nanobiosensing System for Specific Recognition of Drug Subgroups. ACS Sens 2023; 8:2197-2206. [PMID: 37303111 DOI: 10.1021/acssensors.3c00070] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Abnormal cardiac electrophysiological activities significantly contribute to the incidence of cardiovascular diseases. Therefore, it is crucial to recognize effective drugs, which require an accurate, stable, and sensitive platform. Although conventional extracellular recordings offer a non-invasive and label-free manner to monitor the electrophysiological state of cardiomyocytes, the misrepresented and low-quality extracellular action potentials are difficult to provide accurate and high-content information for drug screening. This study presents the development of a three-dimensional cardiomyocyte-nanobiosensing system that can specifically recognize drug subgroups. The nanopillar-based electrode is manufactured by template synthesis and standard microfabrication technology on a porous polyethylene terephthalate membrane. Based on the cardiomyocyte-nanopillar interface, high-quality intracellular action potentials can be recorded by the minimally invasive electroporation. We validate the performance of a cardiomyocyte-nanopillar-based intracellular electrophysiological biosensing platform by two subclasses of sodium channel blockers, quinidine and lidocaine. The recorded intracellular action potentials accurately reveal the subtle differences between these drugs. Our study indicates that high-content intracellular recordings utilizing nanopillar-based biosensing can provide a promising platform for the electrophysiological and pharmacological investigation of cardiovascular diseases.
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Affiliation(s)
- Kai Zhu
- Department of Cardiac Surgery and Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital Fudan University, Shanghai 200032, China
| | - Tao Yan
- Department of Cardiac Surgery and Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital Fudan University, Shanghai 200032, China
| | - Chunlian Qin
- Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, China
| | - Yuxiang Pan
- Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, China
| | - Jun Li
- Department of Cardiac Surgery and Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital Fudan University, Shanghai 200032, China
| | - Hao Lai
- Department of Cardiac Surgery and Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital Fudan University, Shanghai 200032, China
| | - Dongxin Xu
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Chunsheng Wang
- Department of Cardiac Surgery and Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital Fudan University, Shanghai 200032, China
| | - Ning Hu
- Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, China
- Department of Chemistry, Zhejiang University, Hangzhou 310058, China
- State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai 200050, China
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7
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Naseem MU, Gurrola-Briones G, Romero-Imbachi MR, Borrego J, Carcamo-Noriega E, Beltrán-Vidal J, Zamudio FZ, Shakeel K, Possani LD, Panyi G. Characterization and Chemical Synthesis of Cm39 (α-KTx 4.8): A Scorpion Toxin That Inhibits Voltage-Gated K + Channel K V1.2 and Small- and Intermediate-Conductance Ca 2+-Activated K + Channels K Ca2.2 and K Ca3.1. Toxins (Basel) 2023; 15:41. [PMID: 36668861 PMCID: PMC9866218 DOI: 10.3390/toxins15010041] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/22/2022] [Accepted: 12/27/2022] [Indexed: 01/06/2023] Open
Abstract
A novel peptide, Cm39, was identified in the venom of the scorpion Centruroides margaritatus. Its primary structure was determined. It consists of 37 amino acid residues with a MW of 3980.2 Da. The full chemical synthesis and proper folding of Cm39 was obtained. Based on amino acid sequence alignment with different K+ channel inhibitor scorpion toxin (KTx) families and phylogenetic analysis, Cm39 belongs to the α-KTx 4 family and was registered with the systematic number of α-KTx 4.8. Synthetic Cm39 inhibits the voltage-gated K+ channel hKV1.2 with high affinity (Kd = 65 nM). The conductance-voltage relationship of KV1.2 was not altered in the presence of Cm39, and the analysis of the toxin binding kinetics was consistent with a bimolecular interaction between the peptide and the channel; therefore, the pore blocking mechanism is proposed for the toxin-channel interaction. Cm39 also inhibits the Ca2+-activated KCa2.2 and KCa3.1 channels, with Kd = 502 nM, and Kd = 58 nM, respectively. However, the peptide does not inhibit hKV1.1, hKV1.3, hKV1.4, hKV1.5, hKV1.6, hKV11.1, mKCa1.1 K+ channels or the hNaV1.5 and hNaV1.4 Na+ channels at 1 μM concentrations. Understanding the unusual selectivity profile of Cm39 motivates further experiments to reveal novel interactions with the vestibule of toxin-sensitive channels.
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Affiliation(s)
- Muhammad Umair Naseem
- Department of Biophysics and Cell Biology, Faculty of Medicine, Research Center for Molecular Medicine, University of Debrecen, Egyetem ter. 1, 4032 Debrecen, Hungary
| | - Georgina Gurrola-Briones
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca 62210, Morelos, Mexico
| | - Margarita R. Romero-Imbachi
- Grupo de Investigaciones Herpetológicas y Toxinológicas, Centro de Investigaciones Biomédicas, Departamento de Biología, Facultad de Ciencias Naturales, Exactas y de la Educación, Universidad del Cauca, Sector Tulcan, Calle 2 N 3N-100, Popayán 190002, Cauca, Colombia
| | - Jesus Borrego
- Department of Biophysics and Cell Biology, Faculty of Medicine, Research Center for Molecular Medicine, University of Debrecen, Egyetem ter. 1, 4032 Debrecen, Hungary
| | - Edson Carcamo-Noriega
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca 62210, Morelos, Mexico
| | - José Beltrán-Vidal
- Grupo de Investigaciones Herpetológicas y Toxinológicas, Centro de Investigaciones Biomédicas, Departamento de Biología, Facultad de Ciencias Naturales, Exactas y de la Educación, Universidad del Cauca, Sector Tulcan, Calle 2 N 3N-100, Popayán 190002, Cauca, Colombia
| | - Fernando Z. Zamudio
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca 62210, Morelos, Mexico
| | - Kashmala Shakeel
- Department of Biophysics and Cell Biology, Faculty of Medicine, Research Center for Molecular Medicine, University of Debrecen, Egyetem ter. 1, 4032 Debrecen, Hungary
| | - Lourival Domingos Possani
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca 62210, Morelos, Mexico
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, Research Center for Molecular Medicine, University of Debrecen, Egyetem ter. 1, 4032 Debrecen, Hungary
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8
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Liu D, Chen H, Fu Y, Yao Y, He S, Wang Y, Cao Z, Wang X, Yang M, Zhao Q. KCa3.1 Promotes Proinflammatory Exosome Secretion by Activating AKT/Rab27a in Atrial Myocytes during Rapid Pacing. Cardiovasc Ther 2023; 2023:3939360. [PMID: 37035755 PMCID: PMC10079387 DOI: 10.1155/2023/3939360] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 03/04/2023] [Accepted: 03/07/2023] [Indexed: 04/11/2023] Open
Abstract
Purpose The aim of this study was to investigate the role of the medium-conductance calcium-activated potassium channel (KCNN4, KCa3.1) in the secretion of proinflammatory exosomes by atrial myocytes. Methods Eighteen beagles were randomly divided into the sham group (n = 6), pacing group (n = 6), and pacing+TRAM-34 group (n = 6). Electrophysiological data, such as the effective refractory period, atrial fibrillation (AF) induction, and AF duration, were collected by programmed stimulation. Atrial tissues were subjected to hematoxylin and eosin, Masson's trichrome, and immunofluorescence staining. The expression of KCa3.1 and Rab27a was assessed by immunohistochemistry and western blotting. The downstream signaling pathways involved in KCa3.1 were examined by rapid pacing or overexpressing KCNN4 in HL-1 cells. Results Atrial rapid pacing significantly induced electrical remodeling, inflammation, fibrosis, and exosome secretion in the canine atrium, while TRAM-34 (KCa3.1 blocker) inhibited these changes. Compared with those in control HL-1 cells, the levels of exosome markers and inflammatory factors were increased in pacing HL-1 cells. Furthermore, the levels of CD68 and iNOS in macrophages incubated with exosomes derived from HL-1 cells were higher in the pacing-exo group than in the control group. More importantly, KCa3.1 regulated exosome secretion through the AKT/Rab27a signaling pathway. Similarly, inhibiting the downstream signaling pathway of KCa3.1 significantly inhibited exosome secretion. Conclusions KCa3.1 promotes proinflammatory exosome secretion through the AKT/Rab27a signaling pathway. Inhibiting the KCa3.1/AKT/Rab27a signaling pathway reduces myocardial tissue structural remodeling in AF.
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Affiliation(s)
- Dishiwen Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
| | - Huiyu Chen
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
| | - Yuntao Fu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
| | - Yajun Yao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
| | - Shanqing He
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
| | - Youcheng Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
| | - Zhen Cao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
| | - Xuewen Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
| | - Mei Yang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
| | - Qingyan Zhao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
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