1
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Tasca CI, Zuccarini M, Di Iorio P, Ciruela F. Lessons from the physiological role of guanosine in neurodegeneration and cancer: Toward a multimodal mechanism of action? Purinergic Signal 2024:10.1007/s11302-024-10033-y. [PMID: 39004650 DOI: 10.1007/s11302-024-10033-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 06/18/2024] [Indexed: 07/16/2024] Open
Abstract
Neurodegenerative diseases and brain tumours represent important health challenges due to their severe nature and debilitating consequences that require substantial medical care. Interestingly, these conditions share common physiological characteristics, namely increased glutamate, and adenosine transmission, which are often associated with cellular dysregulation and damage. Guanosine, an endogenous nucleoside, is safe and exerts neuroprotective effects in preclinical models of excitotoxicity, along with cytotoxic effects on tumour cells. However, the lack of well-defined mechanisms of action for guanosine hinders a comprehensive understanding of its physiological effects. In fact, the absence of specific receptors for guanosine impedes the development of structure-activity research programs to develop guanosine derivatives for therapeutic purposes. Alternatively, given its apparent interaction with the adenosinergic system, it is plausible that guanosine exerts its neuroprotective and anti-tumorigenic effects by modulating adenosine transmission through undisclosed mechanisms involving adenosine receptors, transporters, and purinergic metabolism. Here, several potential molecular mechanisms behind the protective actions of guanosine will be discussed. First, we explore its potential interaction with adenosine receptors (A1R and A2AR), including the A1R-A2AR heteromer. In addition, we consider the impact of guanosine on extracellular adenosine levels and the role of guanine-based purine-converting enzymes. Collectively, the diverse cellular functions of guanosine as neuroprotective and antiproliferative agent suggest a multimodal and complementary mechanism of action.
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Affiliation(s)
- Carla Inês Tasca
- Department of Biochemistry, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, SC, Brazil.
- Laboratory of Neurochemistry-4, Neuroscience Program/Biochemistry Program, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, SC, Brazil.
| | - Mariachiara Zuccarini
- Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, 66100, Chieti, Italy
- Center for Advanced Studies and Technologies (CAST), University of Chieti-Pescara, 66100, Chieti, Italy
| | - Patrizia Di Iorio
- Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, 66100, Chieti, Italy
- Center for Advanced Studies and Technologies (CAST), University of Chieti-Pescara, 66100, Chieti, Italy
| | - Francisco Ciruela
- Pharmacology Unit, Department of Pathology and Experimental Therapeutics, School of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, 08907 L'Hospitalet de Llobregat, Barcelona, Spain
- Neuropharmacology & Pain Group, Neuroscience Program, Bellvitge Institute for Biomedical Research, 08907L'Hospitalet de Llobregat, Bellvitge, Spain
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2
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Echeverría F, Gonzalez-Sanabria N, Alvarado-Sanchez R, Fernández M, Castillo K, Latorre R. Large conductance voltage-and calcium-activated K + (BK) channel in health and disease. Front Pharmacol 2024; 15:1373507. [PMID: 38584598 PMCID: PMC10995336 DOI: 10.3389/fphar.2024.1373507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/12/2024] [Indexed: 04/09/2024] Open
Abstract
Large Conductance Voltage- and Calcium-activated K+ (BK) channels are transmembrane pore-forming proteins that regulate cell excitability and are also expressed in non-excitable cells. They play a role in regulating vascular tone, neuronal excitability, neurotransmitter release, and muscle contraction. Dysfunction of the BK channel can lead to arterial hypertension, hearing disorders, epilepsy, and ataxia. Here, we provide an overview of BK channel functioning and the implications of its abnormal functioning in various diseases. Understanding the function of BK channels is crucial for comprehending the mechanisms involved in regulating vital physiological processes, both in normal and pathological conditions, controlled by BK. This understanding may lead to the development of therapeutic interventions to address BK channelopathies.
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Affiliation(s)
- Felipe Echeverría
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Naileth Gonzalez-Sanabria
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Rosangelina Alvarado-Sanchez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Miguel Fernández
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Karen Castillo
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Investigación de Estudios Avanzados del Maule, Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca, Chile
| | - Ramon Latorre
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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3
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Van NTH, Kim WK, Nam JH. Challenges in the Therapeutic Targeting of KCa Channels: From Basic Physiology to Clinical Applications. Int J Mol Sci 2024; 25:2965. [PMID: 38474212 PMCID: PMC10932353 DOI: 10.3390/ijms25052965] [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: 12/15/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 03/14/2024] Open
Abstract
Calcium-activated potassium (KCa) channels are ubiquitously expressed throughout the body and are able to regulate membrane potential and intracellular calcium concentrations, thereby playing key roles in cellular physiology and signal transmission. Consequently, it is unsurprising that KCa channels have been implicated in various diseases, making them potential targets for pharmaceutical interventions. Over the past two decades, numerous studies have been conducted to develop KCa channel-targeting drugs, including those for disorders of the central and peripheral nervous, cardiovascular, and urinary systems and for cancer. In this review, we synthesize recent findings regarding the structure and activating mechanisms of KCa channels. We also discuss the role of KCa channel modulators in therapeutic medicine. Finally, we identify the major reasons behind the delay in bringing these modulators to the pharmaceutical market and propose new strategies to promote their application.
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Affiliation(s)
- Nhung Thi Hong Van
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Republic of Korea;
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, Goyang 10326, Republic of Korea
| | - Woo Kyung Kim
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, Goyang 10326, Republic of Korea
- Department of Internal Medicine, Graduate School of Medicine, Dongguk University, Goyang 10326, Republic of Korea
| | - Joo Hyun Nam
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Republic of Korea;
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, Goyang 10326, Republic of Korea
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4
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Feng J, Tian L, Wang W, Yang Y, Li Q, Liu L, Bo H, He C. Effect of RSN1 gene knockout on the adsorption of strontium ions by irradiated Saccharomyces cerevisiae. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2024; 273:107396. [PMID: 38325251 DOI: 10.1016/j.jenvrad.2024.107396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 01/27/2024] [Accepted: 02/02/2024] [Indexed: 02/09/2024]
Abstract
The irradiated Saccharomyces cerevisiae (Y-7) has good biosorption ability for strontium ions. To investigate the mechanism of strontium ion bioaccumulation in Y-7, we employed CRISPR/Cas9 gene editing technology to engineer Saccharomyces cerevisiae Y-7 and knock out the RSN1 gene, successfully constructing a RSN1 gene knockout strain (Y-7-rsn1Δ). When tested for strontium ion adsorption, the Y-7-rsn1Δ strain exhibited decreased capacity for adsorbing strontium ions and increased resistance to strontium ions. The results showed that RSN1 is involved in the transport of Sr2+, and observed significant decreases in intracellular Ca2+ of Y-7-rsn1Δ, indicating a strong correlation between bioaccumulation of Sr2+ and Ca2+. This demonstrated that the adsorption of strontium ions by Y-7 is regulated by the RSN1 gene. The knockout of the RSN1 gene resulted in the shift of the peak positions of carboxyl, amino, amide, hydroxyl, and phosphate groups on the cell surface.
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Affiliation(s)
- Jundong Feng
- Department of Materials Science and Technology, Nanjing University of Aeronautics & Astronautics, Nanjing, 210016, PR China.
| | - Liuxin Tian
- Department of Materials Science and Technology, Nanjing University of Aeronautics & Astronautics, Nanjing, 210016, PR China
| | - Weitai Wang
- Department of Materials Science and Technology, Nanjing University of Aeronautics & Astronautics, Nanjing, 210016, PR China
| | - Yingqing Yang
- Department of Materials Science and Technology, Nanjing University of Aeronautics & Astronautics, Nanjing, 210016, PR China
| | - Qian Li
- Department of Materials Science and Technology, Nanjing University of Aeronautics & Astronautics, Nanjing, 210016, PR China
| | - Liang Liu
- Department of Materials Science and Technology, Nanjing University of Aeronautics & Astronautics, Nanjing, 210016, PR China
| | - Hongyu Bo
- Department of Materials Science and Technology, Nanjing University of Aeronautics & Astronautics, Nanjing, 210016, PR China
| | - Chengyu He
- Department of Materials Science and Technology, Nanjing University of Aeronautics & Astronautics, Nanjing, 210016, PR China
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Chen YC, Shih CL, Wu CL, Fang YH, So EC, Wu SN. Exploring the Impact of BK Ca Channel Function in Cellular Membranes on Cardiac Electrical Activity. Int J Mol Sci 2024; 25:1537. [PMID: 38338830 PMCID: PMC10855144 DOI: 10.3390/ijms25031537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/14/2024] [Accepted: 01/19/2024] [Indexed: 02/12/2024] Open
Abstract
This review paper delves into the current body of evidence, offering a thorough analysis of the impact of large-conductance Ca2+-activated K+ (BKCa or BK) channels on the electrical dynamics of the heart. Alterations in the activity of BKCa channels, responsible for the generation of the overall magnitude of Ca2+-activated K+ current at the whole-cell level, occur through allosteric mechanisms. The collaborative interplay between membrane depolarization and heightened intracellular Ca2+ ion concentrations collectively contribute to the activation of BKCa channels. Although fully developed mammalian cardiac cells do not exhibit functional expression of these ion channels, evidence suggests their presence in cardiac fibroblasts that surround and potentially establish close connections with neighboring cardiac cells. When cardiac cells form close associations with fibroblasts, the high single-ion conductance of these channels, approximately ranging from 150 to 250 pS, can result in the random depolarization of the adjacent cardiac cell membranes. While cardiac fibroblasts are typically electrically non-excitable, their prevalence within heart tissue increases, particularly in the context of aging myocardial infarction or atrial fibrillation. This augmented presence of BKCa channels' conductance holds the potential to amplify the excitability of cardiac cell membranes through effective electrical coupling between fibroblasts and cardiomyocytes. In this scenario, this heightened excitability may contribute to the onset of cardiac arrhythmias. Moreover, it is worth noting that the substances influencing the activity of these BKCa channels might influence cardiac electrical activity as well. Taken together, the BKCa channel activity residing in cardiac fibroblasts may contribute to cardiac electrical function occurring in vivo.
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Affiliation(s)
- Yin-Chia Chen
- Division of Cardiovascular Surgery, Department of Surgery, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 60002, Taiwan
| | - Chia-Lung Shih
- Clinical Research Center, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 60056, Taiwan
| | - Chao-Liang Wu
- Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 60002, Taiwan
| | - Yi-Hsien Fang
- Institute of Clinical Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70403, Taiwan
| | - Edmund Cheung So
- Department of Anesthesia, An Nan Hospital, China Medical University, Tainan 70965, Taiwan
| | - Sheng-Nan Wu
- Department of Research and Education, An Nan Hospital, China Medical University, Tainan 70965, Taiwan
- School of Medicine, College of Medicine, National Sun Yat-sen University, Kaohsiung 80421, Taiwan
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6
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Tran NLH, Lam TQ, Duong PVQ, Doan LH, Vu MP, Nguyen KHP, Nguyen KT. Review on the Significant Interactions between Ultrafine Gas Bubbles and Biological Systems. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:984-996. [PMID: 38153335 DOI: 10.1021/acs.langmuir.3c03223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Having sizes comparable with living cells and high abundance, ultrafine bubbles (UBs) are prone to inevitable interactions with different types of cells and facilitate alterations in physiological properties. The interactions of four typical cell types (e.g., bacterial, fungal, plant, and mammalian cells) with UBs have been studied over recent years. For bacterial cells, UBs have been utilized in creating the capillary force to tear down biofilms. The release of high amounts of heat, pressure, and free radicals during bubble rupture is also found to affect bacterial cell growth. Similarly, the bubble gas core identity plays an important role in the development of fungal cells. By the proposed mechanism of attachment of UBs on hydrophobin proteins in the fungal cell wall, oxygen and ozone gas-filled ultrafine bubbles can either promote or hinder the cell growth rate. On the other hand, reactive oxygen species (ROS) formation and mass transfer facilitation are two means of indirect interactions between UBs and plant cells. Likewise, the use of different gas cores in generating bubbles can produce different physical effects on these cells, for example, hydrogen gas for antioxidation against infections and oxygen for oxidation of toxic metal ions. For mammalian cells, the importance of investigating their interactions with UBs lies in the bubbles' action on cell viability as membrane poration for drug delivery can greatly affect cells' survival. UBs have been utilized and tested in forming the pores by different methods, ranging from bubble oscillation and microstream generation through acoustic cavitation to bubble implosion.
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Affiliation(s)
- Nguyen Le Hanh Tran
- School of Biotechnology, International University, Vietnam National University, Ho Chi Minh City 700000, Vietnam
| | - Thien Quang Lam
- School of Biotechnology, International University, Vietnam National University, Ho Chi Minh City 700000, Vietnam
| | - Phuong Vu Quynh Duong
- School of Biotechnology, International University, Vietnam National University, Ho Chi Minh City 700000, Vietnam
| | - Linh Hai Doan
- School of Biotechnology, International University, Vietnam National University, Ho Chi Minh City 700000, Vietnam
| | - Mai Phuong Vu
- School of Biotechnology, International University, Vietnam National University, Ho Chi Minh City 700000, Vietnam
| | - Khang Huy Phuc Nguyen
- School of Biotechnology, International University, Vietnam National University, Ho Chi Minh City 700000, Vietnam
| | - Khoi Tan Nguyen
- School of Biotechnology, International University, Vietnam National University, Ho Chi Minh City 700000, Vietnam
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7
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Maliszewska-Olejniczak K, Bednarczyk P. Novel insights into the role of ion channels in cellular DNA damage response. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2024; 793:108488. [PMID: 38266668 DOI: 10.1016/j.mrrev.2024.108488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 01/18/2024] [Accepted: 01/19/2024] [Indexed: 01/26/2024]
Abstract
The DNA damage response (DDR) is a complex and highly regulated cellular process that detects and repairs DNA damage. The integrity of the DNA molecule is crucial for the proper functioning and survival of cells, as DNA damage can lead to mutations, genomic instability, and various diseases, including cancer. The DDR safeguards the genome by coordinating a series of signaling events and repair mechanisms to maintain genomic stability and prevent the propagation of damaged DNA to daughter cells. The study of an ion channels in the context of DDR is a promising avenue in biomedical research. Lately, it has been reported that the movement of ions through channels plays a crucial role in various physiological processes, including nerve signaling, muscle contraction, cell signaling, and maintaining cell membrane potential. Knowledge regarding the involvement of ion channels in the DDR could support refinement of our approach to several pathologies, mainly cancer, and perhaps lead to innovative therapies. In this review, we focused on the ion channel's possible role in the DDR. We present an analysis of the involvement of ion channels in DDR, their role in DNA repair mechanisms, and cellular outcomes. By addressing these areas, we aim to provide a comprehensive perspective on ion channels in the DDR and potentially guide future research in this field. It is worth noting that the interplay between ion channels and the cellular DDR is complex and multifaceted. More research is needed to fully understand the underlying mechanisms and potential therapeutic implications of these interactions.
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Affiliation(s)
- Kamila Maliszewska-Olejniczak
- Department of Physics and Biophysics, Institute of Biology, Warsaw University of Life Sciences - SGGW, Warsaw, Poland.
| | - Piotr Bednarczyk
- Department of Physics and Biophysics, Institute of Biology, Warsaw University of Life Sciences - SGGW, Warsaw, Poland
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8
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Lai H, Gao M, Yang H. The potassium channels: Neurobiology and pharmacology of tinnitus. J Neurosci Res 2024; 102:e25281. [PMID: 38284861 DOI: 10.1002/jnr.25281] [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: 04/23/2023] [Revised: 10/27/2023] [Accepted: 11/16/2023] [Indexed: 01/30/2024]
Abstract
Tinnitus is a widespread public health issue that imposes a significant social burden. The occurrence and maintenance of tinnitus have been shown to be associated with abnormal neuronal activity in the auditory pathway. Based on this view, neurobiological and pharmacological developments in tinnitus focus on ion channels and synaptic neurotransmitter receptors in neurons in the auditory pathway. With major breakthroughs in the pathophysiology and research methodology of tinnitus in recent years, the role of the largest family of ion channels, potassium ion channels, in modulating the excitability of neurons involved in tinnitus has been increasingly demonstrated. More and more potassium channels involved in the neural mechanism of tinnitus have been discovered, and corresponding drugs have been developed. In this article, we review animal (mouse, rat, hamster, and guinea-pig), human, and genetic studies on the different potassium channels involved in tinnitus, analyze the limitations of current clinical research on potassium channels, and propose future prospects. The aim of this review is to promote the understanding of the role of potassium ion channels in tinnitus and to advance the development of drugs targeting potassium ion channels for tinnitus.
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Affiliation(s)
- Haohong Lai
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Minqian Gao
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Department of Hearing and Speech-Language Science, Guangzhou Xinhua University, Guangzhou, China
| | - Haidi Yang
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Department of Hearing and Speech-Language Science, Guangzhou Xinhua University, Guangzhou, China
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9
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Spekker E, Nagy-Grócz G, Vécsei L. Ion Channel Disturbances in Migraine Headache: Exploring the Potential Role of the Kynurenine System in the Context of the Trigeminovascular System. Int J Mol Sci 2023; 24:16574. [PMID: 38068897 PMCID: PMC10706278 DOI: 10.3390/ijms242316574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/13/2023] [Accepted: 11/16/2023] [Indexed: 12/18/2023] Open
Abstract
Migraine is a primary headache disorder, which is an enormous burden to the healthcare system. While some aspects of the pathomechanism of migraines remain unknown, the most accepted theory is that activation and sensitization of the trigeminovascular system are essential during migraine attacks. In recent decades, it has been suggested that ion channels may be important participants in the pathogenesis of migraine. Numerous ion channels are expressed in the peripheral and central nervous systems, including the trigeminovascular system, affecting neuron excitability, synaptic energy homeostasis, inflammatory signaling, and pain sensation. Dysfunction of ion channels could result in neuronal excitability and peripheral or central sensitization. This narrative review covers the current understanding of the biological mechanisms leading to activation and sensitization of the trigeminovascular pain pathway, with a focus on recent findings on ion channel activation and modulation. Furthermore, we focus on the kynurenine pathway since this system contains kynurenic acid, which is an endogenous glutamate receptor antagonist substance, and it has a role in migraine pathophysiology.
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Affiliation(s)
| | - Gábor Nagy-Grócz
- Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, H-6725 Szeged, Hungary;
- Faculty of Health Sciences and Social Studies, University of Szeged, H-6726 Szeged, Hungary
- Preventive Health Sciences Research Group, Incubation Competence Centre of the Centre of Excellence for Interdisciplinary Research, Development and Innovation of the University of Szeged, H-6725 Szeged, Hungary
| | - László Vécsei
- Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, H-6725 Szeged, Hungary;
- HUN-REN-SZTE Neuroscience Research Group, University of Szeged, H-6725 Szeged, Hungary
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10
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Oliveira N, Marcelino H, Azevedo R, Verde I. Effects of bisphenol A on human umbilical arteries. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:27670-27681. [PMID: 36385337 DOI: 10.1007/s11356-022-24069-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/03/2022] [Indexed: 06/16/2023]
Abstract
Bisphenol A (BPA) is an endocrine-disrupting chemical widely used in the plastics industry, including food container, toys, and medical equipment. We analyzed the effect of BPA in human umbilical artery contractility and expression of some proteins modulating this function, such as ionic channels and proteins involved in the cGMP pathway. Using standard organ bath technique, rings of human umbilical arteries without endothelium were contracted by 5-HT (1 μM) and histamine (10 μM) and the effect of different concentrations of BPA (1 nM-100 μM) was analyzed. The results showed that BPA is a vasodilator of these arteries in a concentration-dependent way. Besides, qPCR studies on human umbilical smooth muscle cells (HUSMC) allowed to analyze the effects of BPA on gene expression. Thus, 12-h exposition to BPA induced reduction of expression of L-type calcium channels (LTCC), alpha subunit of BKCa channels, and Kvβ1 and Kvβ3 from Kv channels. BPA also decreased the expression of soluble guanylate cyclase (sGC) and natriuretic peptide receptor type A (NPRA), meanwhile increasing that of PKG, proteins involved in vasodilation of human umbilical arteries (HUA) by cGMP. Further studies will be necessary to increase knowledge about the implications of these changes induced by BPA exposure.
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Affiliation(s)
- Nádia Oliveira
- Faculty of Health Sciences & Health Sciences Research Centre (CICS-UBI; Centro de Investigação em Ciências da Saúde), University of Beira Interior, Av. Infante D. Henrique S/N, 6200-506, Covilhã, Portugal
| | - Helena Marcelino
- Faculty of Health Sciences & Health Sciences Research Centre (CICS-UBI; Centro de Investigação em Ciências da Saúde), University of Beira Interior, Av. Infante D. Henrique S/N, 6200-506, Covilhã, Portugal
| | - Regina Azevedo
- Faculty of Health Sciences & Health Sciences Research Centre (CICS-UBI; Centro de Investigação em Ciências da Saúde), University of Beira Interior, Av. Infante D. Henrique S/N, 6200-506, Covilhã, Portugal
| | - Ignacio Verde
- Faculty of Health Sciences & Health Sciences Research Centre (CICS-UBI; Centro de Investigação em Ciências da Saúde), University of Beira Interior, Av. Infante D. Henrique S/N, 6200-506, Covilhã, Portugal.
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11
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Dickson EJ. Role of Lysosomal Cholesterol in Regulating PI(4,5)P 2-Dependent Ion Channel Function. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1422:193-215. [PMID: 36988882 DOI: 10.1007/978-3-031-21547-6_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Lysosomes are central regulators of cellular growth and signaling. Once considered the acidic garbage can of the cell, their ever-expanding repertoire of functions include the regulation of cell growth, gene regulation, metabolic signaling, cell migration, and cell death. In this chapter, we detail how another of the lysosome's crucial roles, cholesterol transport, plays a vital role in the control of ion channel function and neuronal excitability through its ability to influence the abundance of the plasma membrane signaling lipid phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). This chapter will introduce the biosynthetic pathways of cholesterol and PI(4,5)P2, discuss the molecular mechanisms through which each lipid distinctly regulates ion channels, and consider the interdependence of these lipids in the control of ion channel function.
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Affiliation(s)
- Eamonn J Dickson
- Department of Physiology and Membrane Biology, University of California, Davis, CA, USA.
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12
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Kampa RP, Sęk A, Bednarczyk P, Szewczyk A, Calderone V, Testai L. Flavonoids as new regulators of mitochondrial potassium channels: contribution to cardioprotection. J Pharm Pharmacol 2022; 75:466-481. [PMID: 36508341 DOI: 10.1093/jpp/rgac093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/18/2022] [Indexed: 12/14/2022]
Abstract
Abstract
Objectives
Acute myocardial ischemia is one of the major causes of illness in western society. Reduced coronary blood supply leads to cell death and loss of cardiomyocyte population, resulting in serious and often irreversible consequences on myocardial function. Mitochondrial potassium (mitoK) channels have been identified as fine regulators of mitochondrial function and, consequently, in the metabolism of the whole cell, and in the mechanisms underlying the cardioprotection. Interestingly, mitoK channels represent a novel putative target for treating cardiovascular diseases, particularly myocardial infarction, and their modulators represent an interesting tool for pharmacological intervention. In this review, we took up the challenge of selecting flavonoids that show cardioprotective properties through the activation of mitoK channels.
Key findings
A brief overview of the main information on mitoK channels and their participation in the induction of cytoprotective processes was provided. Then, naringenin, quercetin, morin, theaflavin, baicalein, epigallocatechin gallate, genistein, puerarin, luteolin and proanthocyanidins demonstrated to be effective modulators of mitoK channels activity, mediating many beneficial effects.
Summary
The pathophysiological role of mitoK channels has been investigated as well as the impact of flavonoids on this target with particular attention to their potential role in the prevention of cardiovascular disorders.
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Affiliation(s)
- Rafał P Kampa
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology PAS , Warsaw , Poland
- Department of Pharmacy, University of Pisa , Italy
| | - Aleksandra Sęk
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology PAS , Warsaw , Poland
- Faculty of Chemistry, University of Warsaw , Warsaw , Poland
| | - Piotr Bednarczyk
- Department of Physics and Biophysics, Institute of Biology, Warsaw University of Life Sciences, SGGW , Warsaw , Poland
| | - Adam Szewczyk
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology PAS , Warsaw , Poland
| | | | - Lara Testai
- Department of Pharmacy, University of Pisa , Italy
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13
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Feng D, Guo YY, Wang W, Yan LF, Sun T, Liu QQ, Cui GB, Nan HY. α-Subunit Tyrosine Phosphorylation Is Required for Activation of the Large Conductance Ca 2+-Activated Potassium Channel in the Rabbit Sphincter of Oddi. THE AMERICAN JOURNAL OF PATHOLOGY 2022; 192:1725-1744. [PMID: 36150507 DOI: 10.1016/j.ajpath.2022.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 08/06/2022] [Accepted: 08/31/2022] [Indexed: 06/16/2023]
Abstract
Large conductance Ca2+-activated potassium (BKCa) channels are regulated by intracellular free Ca2+ concentrations ([Ca2+]i) and channel protein phosphorylation. In hypercholesterolemia (HC), motility impairment of the sphincter of Oddi (SO) is associated with abnormal [Ca2+]i accumulation in smooth muscle cells of the rabbit SO (RSOSMCs), which is closely related to BKCa channel activity. However, the underlying mechanisms regulating channel activity remain unclear. In this study, an HC rabbit model was generated and used to investigate BKCa channel activity of RSOSMCs via SO muscle tone measurement in vitro and manometry in vivo, electrophysiological recording, intracellular calcium measurement, and Western blot analyses. BKCa channel activity was decreased, which correlated with [Ca2+]i overload and reduced tyrosine phosphorylation of the BKCa α-subunit in the HC group. The abnormal [Ca2+]i accumulation and decreased BKCa channel activity were partially restored by Na3VO4 pretreatment but worsened by genistein in RSOSMCs in the HC group. This study suggests that α-subunit tyrosine phosphorylation is required for [Ca2+]i to activate BKCa channels, and there is a negative feedback between the BKCa channel and the L-type voltage-dependent Ca2+ channel that regulates [Ca2+]i. This study provides direct evidence that tyrosine phosphorylation of BKCa α-subunits is required for [Ca2+]i to activate BKCa channels in RSOSMCs, which may be the underlying physiological and pathologic mechanism regulating the activity of BKCa channels in SO cells.
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Affiliation(s)
- Dan Feng
- Department of Radiology and Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Yan-Yan Guo
- Department of Pharmacy, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Wen Wang
- Department of Radiology and Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Lin-Feng Yan
- Department of Radiology and Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Ting Sun
- Department of Pharmacy, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Qing-Qing Liu
- Department of Pharmacy, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Guang-Bin Cui
- Department of Radiology and Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.
| | - Hai-Yan Nan
- Department of Radiology and Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.
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14
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McGahan K, Keener J. Modeling the kinetics of heteromeric potassium channels. Front Cell Neurosci 2022; 16:1036813. [DOI: 10.3389/fncel.2022.1036813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 10/24/2022] [Indexed: 11/11/2022] Open
Abstract
Mechanistic mathematical modeling has long been used as a tool for answering questions in cellular physiology. To mathematically describe cellular processes such as cell excitability, volume regulation, neurotransmitter release, and hormone secretion requires accurate descriptions of ion channel kinetics. One class of ion channels currently lacking a physiological model framework is the class of channels built with multiple different potassium protein subunits called heteromeric voltage gated potassium channels. Here we present a novel mathematical model for heteromeric potassium channels that captures both the number and type of protein subunits present in each channel. Key model assumptions are validated by showing our model is the reduction of a Markov model and through observations about voltage clamp data. We then show our model's success in replicating kinetic properties of concatemeric channels with different numbers of Kv1.1 and Kv1.2 subunits. Finally, through comparisons with multiple expression experiments across multiple voltage gated potassium families, we use the model to make predictions about the importance and effect of genetic mutations in heteromeric channel formation.
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15
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Zhang X, Yang M, Lv D, Xie Y, Sun Y, Zhang Y, He M, Liu H, Li F, Deng D. Effects of KCa channels on biological behavior of trophoblasts. Open Life Sci 2022; 17:1043-1052. [PMID: 36118166 PMCID: PMC9441684 DOI: 10.1515/biol-2022-0462] [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: 01/16/2022] [Revised: 05/12/2022] [Accepted: 06/14/2022] [Indexed: 11/29/2022] Open
Abstract
The Ca2+-activated potassium (KCa) channels are involved in many cellular functions, but their roles in trophoblasts are unclear. This study aimed to clarify the effects of KCa channels on the biological behavior of trophoblasts. The localization and expression of the three types of KCa channels, including large-conductance KCa channels (BKCa), intermediate-conductance KCa channels (IKCa), and small-conductance KCa channels (SKCa), were detected in human chorionic villi taken from pregnant women between 5 and 8 weeks of gestation (n = 15) and HTR-8/SVneo cells. The effects of KCa channels on proliferation, apoptosis, and migration of HTR-8/SVneo cells were examined by using the activators or inhibitors of KCa channels. Results showed that KCa channels were mainly localized on the membrane and in the cytoplasm of trophoblasts in human chorionic villi and HTR-8/SVneo cells. The proliferation and migration of HTR-8/SVneo cells were inhibited by activating KCa channels. Apoptosis of trophoblasts was promoted through activating BKCa channels but was not affected by neither activating nor inhibiting IKCa and SKCa channels. This study substantiated the abovementioned biological roles of KCa channels in trophoblast cells, which is fundamental to further research on whether dysfunction of KCa channels is involved in the pathogenesis of pregnancy-related complications.
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Affiliation(s)
- Xiaolei Zhang
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Meitao Yang
- Department of Gynecology and Obstetrics, Zhongnan Hospital, Wuhan University, Wuhan, 430071, China
| | - Dan Lv
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Yin Xie
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Yanan Sun
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Yanling Zhang
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Mengzhou He
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Haiyi Liu
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Fanfan Li
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Dongrui Deng
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
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16
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Yang H, Hou C, Xiao W, Qiu Y. The role of mechanosensitive ion channels in the gastrointestinal tract. Front Physiol 2022; 13:904203. [PMID: 36060694 PMCID: PMC9437298 DOI: 10.3389/fphys.2022.904203] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
Mechanosensation is essential for normal gastrointestinal (GI) function, and abnormalities in mechanosensation are associated with GI disorders. There are several mechanosensitive ion channels in the GI tract, namely transient receptor potential (TRP) channels, Piezo channels, two-pore domain potassium (K2p) channels, voltage-gated ion channels, large-conductance Ca2+-activated K+ (BKCa) channels, and the cystic fibrosis transmembrane conductance regulator (CFTR). These channels are located in many mechanosensitive intestinal cell types, namely enterochromaffin (EC) cells, interstitial cells of Cajal (ICCs), smooth muscle cells (SMCs), and intrinsic and extrinsic enteric neurons. In these cells, mechanosensitive ion channels can alter transmembrane ion currents in response to mechanical forces, through a process known as mechanoelectrical coupling. Furthermore, mechanosensitive ion channels are often associated with a variety of GI tract disorders, including irritable bowel syndrome (IBS) and GI tumors. Mechanosensitive ion channels could therefore provide a new perspective for the treatment of GI diseases. This review aims to highlight recent research advances regarding the function of mechanosensitive ion channels in the GI tract. Moreover, it outlines the potential role of mechanosensitive ion channels in related diseases, while describing the current understanding of interactions between the GI tract and mechanosensitive ion channels.
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Affiliation(s)
- Haoyu Yang
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing, China
| | - Chaofeng Hou
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing, China
| | - Weidong Xiao
- Department of General Surgery, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Yuan Qiu
- Department of General Surgery, Xinqiao Hospital, Army Medical University, Chongqing, China
- *Correspondence: Yuan Qiu,
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17
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Nikitin ES, Balaban PM, Zaitsev AV. Prospects for Gene Therapy of Epilepsy Using Calcium-Acivated Potassium Channel Vectors. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022040111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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18
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Bae EJ, Jo H, Kim SS, Shin DS, Yang JY, Bae MA, Jeong P, Park CS, Ahn JH. Novel Thioxothiazolo[3,4- a]quinazolin-5(4 H)-one Derivatives as BK Ca Channel Activators for Urinary Incontinence. ACS Med Chem Lett 2022; 13:1052-1061. [DOI: 10.1021/acsmedchemlett.2c00070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Eun Jung Bae
- Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Heeji Jo
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Seong Soon Kim
- Bio & Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea
| | - Dae-Seop Shin
- Bio & Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea
| | - Jung Yoon Yang
- Bio & Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea
| | - Myung Ae Bae
- Bio & Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea
| | - Pyeonghwa Jeong
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Chul-Seung Park
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Jin Hee Ahn
- Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
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19
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Ogishi K, Osaki T, Morimoto Y, Takeuchi S. 3D printed microfluidic devices for lipid bilayer recordings. LAB ON A CHIP 2022; 22:890-898. [PMID: 35133381 DOI: 10.1039/d1lc01077h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
This paper verifies the single-step and monolithic fabrication of 3D structural lipid bilayer devices using stereolithography. Lipid bilayer devices are utilized to host membrane proteins in vitro for biological assays or sensing applications. There is a growing demand to fabricate functional lipid bilayer devices with a short lead-time, and the monolithic fabrication of components by 3D printing is highly anticipated. However, the prerequisites of 3D printing materials which lead to reproducible lipid bilayer formation are still unknown. Here, we examined the feasibility of membrane protein measurement using lipid bilayer devices fabricated by stereolithography. The 3D printing materials were characterized and the surface smoothness and hydrophobicity were found to be the relevant factors for successful lipid bilayer formation. The devices were comparable to the ones fabricated by conventional procedures in terms of measurement performances like the amplitude of noise and the waiting time for lipid bilayer formation. We further demonstrated the extendibility of the technology for the functionalization of devices, such as incorporating microfluidic channels for solution exchangeability and arraying multiple chambers for robust measurement.
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Affiliation(s)
- Kazuto Ogishi
- Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
| | - Toshihisa Osaki
- Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012, Japan
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
| | - Yuya Morimoto
- Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
| | - Shoji Takeuchi
- Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
- Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012, Japan
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
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20
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Shah KR, Guan X, Yan J. Structural and Functional Coupling of Calcium-Activated BK Channels and Calcium-Permeable Channels Within Nanodomain Signaling Complexes. Front Physiol 2022; 12:796540. [PMID: 35095560 PMCID: PMC8795833 DOI: 10.3389/fphys.2021.796540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 12/28/2021] [Indexed: 11/13/2022] Open
Abstract
Biochemical and functional studies of ion channels have shown that many of these integral membrane proteins form macromolecular signaling complexes by physically associating with many other proteins. These macromolecular signaling complexes ensure specificity and proper rates of signal transduction. The large-conductance, Ca2+-activated K+ (BK) channel is dually activated by membrane depolarization and increases in intracellular free Ca2+ ([Ca2+]i). The activation of BK channels results in a large K+ efflux and, consequently, rapid membrane repolarization and closing of the voltage-dependent Ca2+-permeable channels to limit further increases in [Ca2+]i. Therefore, BK channel-mediated K+ signaling is a negative feedback regulator of both membrane potential and [Ca2+]i and plays important roles in many physiological processes and diseases. However, the BK channel formed by the pore-forming and voltage- and Ca2+-sensing α subunit alone requires high [Ca2+]i levels for channel activation under physiological voltage conditions. Thus, most native BK channels are believed to co-localize with Ca2+-permeable channels within nanodomains (a few tens of nanometers in distance) to detect high levels of [Ca2+]i around the open pores of Ca2+-permeable channels. Over the last two decades, advancement in research on the BK channel’s coupling with Ca2+-permeable channels including recent reports involving NMDA receptors demonstrate exemplary models of nanodomain structural and functional coupling among ion channels for efficient signal transduction and negative feedback regulation. We hereby review our current understanding regarding the structural and functional coupling of BK channels with different Ca2+-permeable channels.
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Affiliation(s)
- Kunal R. Shah
- Department of Anesthesiology & Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Xin Guan
- Department of Anesthesiology & Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Jiusheng Yan
- Department of Anesthesiology & Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
- Neuroscience Program, Graduate School of Biomedical Sciences, UT Health, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
- Biochemistry and Cell Biology Program, Graduate School of Biomedical Sciences, UT Health, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
- *Correspondence: Jiusheng Yan,
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21
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Yang C, Yang Z, Tong K, Wang J, Yang W, Yu R, Jiang F, Ji Y. Homology modeling and molecular docking simulation of martentoxin as a specific inhibitor of the BK channel. ANNALS OF TRANSLATIONAL MEDICINE 2022; 10:71. [PMID: 35282126 PMCID: PMC8848368 DOI: 10.21037/atm-21-6967] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 01/13/2022] [Indexed: 11/18/2022]
Abstract
Background Large conductance calcium-activated potassium channel (BK channel) is gated by both voltage and calcium ions and is widely distributed in excitable and nonexcitable cells. BK channel plays an important role in epilepsy and other diseases, but BK channel subtype-specific drugs are still extremely rare. Martentoxin was previously isolated from the venom of members of Scorpionidae and shown to be composed of 37 amino acids. Research has shown that the pharmacological selectivity of martentoxin to the BK channel is higher than that to other potassium channels. Therefore, it is of great significance to study the mechanism of interaction between martentoxin and BK channels. Methods The three-dimensional structure of BK channel pore region was constructed by homologous modeling method, and the key amino acid sites of BK channel interaction with martentoxin were analyzed by protein-protein docking, molecular dynamic simulation and virtual alanine mutation. Results Based on homologous modeling of BK channel pore structure and protein-protein docking analysis, Phe1, Lys28 and Arg35 of martentoxin were found to be key amino acids in toxin BK channel interaction. Conclusions This study reveals the structural basis of martentoxin interaction with BK channel. These results will contribute to the design of BK channel specific blockers based on the structure of martentoxin.
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Affiliation(s)
- Chao Yang
- Translational Institute for Cancer Pain, Chongming Hospital Affiliated to Shanghai University of Medicine and Health Sciences (Xinhua Hospital Chongming Branch), Shanghai, China
| | - Zihao Yang
- College of Life Sciences and Food Engineering, Huaiyin Institute of Technology, Huai'an, China
| | - Kuiyuan Tong
- College of Life Sciences and Food Engineering, Huaiyin Institute of Technology, Huai'an, China
| | - Jiawei Wang
- School of Life and Medicine Sciences, Shanghai University, Shanghai, China
| | - Wanli Yang
- Translational Institute for Cancer Pain, Chongming Hospital Affiliated to Shanghai University of Medicine and Health Sciences (Xinhua Hospital Chongming Branch), Shanghai, China
| | - Ruihua Yu
- Translational Institute for Cancer Pain, Chongming Hospital Affiliated to Shanghai University of Medicine and Health Sciences (Xinhua Hospital Chongming Branch), Shanghai, China
| | - Feng Jiang
- Translational Institute for Cancer Pain, Chongming Hospital Affiliated to Shanghai University of Medicine and Health Sciences (Xinhua Hospital Chongming Branch), Shanghai, China
| | - Yonghua Ji
- Translational Institute for Cancer Pain, Chongming Hospital Affiliated to Shanghai University of Medicine and Health Sciences (Xinhua Hospital Chongming Branch), Shanghai, China.,School of Life and Medicine Sciences, Shanghai University, Shanghai, China
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22
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Uray IP, Uray K. Mechanotransduction at the Plasma Membrane-Cytoskeleton Interface. Int J Mol Sci 2021; 22:11566. [PMID: 34768998 PMCID: PMC8584042 DOI: 10.3390/ijms222111566] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 02/08/2023] Open
Abstract
Mechanical cues are crucial for survival, adaptation, and normal homeostasis in virtually every cell type. The transduction of mechanical messages into intracellular biochemical messages is termed mechanotransduction. While significant advances in biochemical signaling have been made in the last few decades, the role of mechanotransduction in physiological and pathological processes has been largely overlooked until recently. In this review, the role of interactions between the cytoskeleton and cell-cell/cell-matrix adhesions in transducing mechanical signals is discussed. In addition, mechanosensors that reside in the cell membrane and the transduction of mechanical signals to the nucleus are discussed. Finally, we describe two examples in which mechanotransduction plays a significant role in normal physiology and disease development. The first example is the role of mechanotransduction in the proliferation and metastasis of cancerous cells. In this system, the role of mechanotransduction in cellular processes, including proliferation, differentiation, and motility, is described. In the second example, the role of mechanotransduction in a mechanically active organ, the gastrointestinal tract, is described. In the gut, mechanotransduction contributes to normal physiology and the development of motility disorders.
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Affiliation(s)
- Iván P. Uray
- Department of Clinical Oncology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary;
| | - Karen Uray
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
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23
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He Y, Lin Y, He F, Shao L, Ma W, He F. Role for calcium-activated potassium channels (BK) in migration control of human hepatocellular carcinoma cells. J Cell Mol Med 2021; 25:9685-9696. [PMID: 34514691 PMCID: PMC8505838 DOI: 10.1111/jcmm.16918] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/19/2021] [Accepted: 09/01/2021] [Indexed: 01/21/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is a leading cause of cancer‐related death worldwide. Its high metastasis rate is significantly correlated with poor patient prognosis. Elucidating the molecular mechanism underlying HCC metastasis is essential for HCC treatment. Owing to their high conductance, large‐conductance calcium‐activated potassium channels (BK channels) play a critical role in the control of membrane potential and have repeatedly been proposed as potential targets for cancer therapy. Emerging evidence suggests that BK channels are involved in the progression of cancer malignancies. The present study investigated the role of BK channels in mediating the hypoxia‐stimulated migration of HCC cells both in vitro and in vivo in the absence and presence of various BK channels modulators. We found that BK channels were functionally expressed on the membranes of the SMMC‐7721 and Huh7 HCC cell lines. Furthermore, blockage or activation of BK channels on the surface of HCC cells correspondingly inhibited or promoted HCC cell proliferation, migration and invasion in hypoxia conditions, with altered expression and distribution of cell‐cell adhesion molecule E‐cadherin and typical marker of mesenchymal cells, Vimentin, but not N‐cadherin. Hypoxia conditions did not alter BK channels expression but increased its open probability. Moreover, BK channels blocker IbTX significantly inhibited HCC cell remote colonization in HCC cell xenografted mice. In conclusion, the results of this study suggest that blocking BK channels offers an attractive strategy for treating HCC.
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Affiliation(s)
- Yuan He
- Department of General Surgery, Changzhi Medical College Affiliated Heping Hospital, Changzhi, China
| | - Yingying Lin
- Department of Immunology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Fei He
- Department of Stomatology, The Second Clinical Medical College, Shenzhen People's Hospital, Jinan University, Shenzhen, China
| | - Lijuan Shao
- Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou, China
| | - Wei Ma
- Translational Medicine Collaborative Innovation Center of Shenzhen People's Hospital, The Second Clinical Medical College of Jinan University, The First Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
| | - Fei He
- Translational Medicine Collaborative Innovation Center of Shenzhen People's Hospital, The Second Clinical Medical College of Jinan University, The First Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
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24
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Neonatal Diabetes in Patients Affected by Liang-Wang Syndrome Carrying KCNMA1 Variant p.(Gly375Arg) Suggest a Potential Role of Ca 2+ and Voltage-Activated K + Channel Activity in Human Insulin Secretion. Curr Issues Mol Biol 2021; 43:1036-1042. [PMID: 34563042 PMCID: PMC8928946 DOI: 10.3390/cimb43020073] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/21/2021] [Accepted: 08/23/2021] [Indexed: 12/22/2022] Open
Abstract
Liang-Wang syndrome (LIWAS) is a polymalformative syndrome first described in 2019 caused by heterozygous mutation of the KCNMA1 gene encoding the Ca2+ and voltage-activated K+ channel (BKC). The KCNMA1 variant p.(Gly356Arg) abolishes the function of BKC and blocks the generation of K+ current. The phenotype of this variant includes developmental delay, and visceral and connective tissue malformations. So far, only three cases of LWAS have been described, one of which also had neonatal diabetes (ND). We present the case of a newborn affected by LIWAS carrying the p.(Gly375Arg) variant who manifested diabetes in the first week of life. The description of our case strongly increases the frequency of ND in LIWAS patients and suggests a role of BK inactivation in human insulin secretion. The knowledge on the role of BKC in insulin secretion is very poor. Analyzing the possible mechanisms that could explain the association of LIWAS with ND, we speculate that BK inactivation might impair insulin secretion through the alteration of ion-dependent membrane activities and mitochondrial functions in β-cells, as well as the impaired intra-islet vessel reactivity.
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25
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Mir JM, Maurya RC, Khan MW. NO, CO and H2S based pharmaceuticals in the mission of vision (eye health): a comprehensive review. REV INORG CHEM 2021. [DOI: 10.1515/revic-2021-0009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Abstract
A set of well defined signaling molecules responsible for normal functioning of human physiology including nitric oxide along with carbon monoxide and hydrogen sulphide are referred as “gasotransmitters”. Due to their involvement in almost every system of a human body, the care of highly sensitive organs using these molecules as drugs represents highly fascinating area of research. In connection with these interesting aspects, the applied aspects of these gaseous molecules in maintaining healthy eye and vision have been targeted in this review. Several examples of eye-droppers including NORMs like latanoprost and nipradiol, CORMs like CORM-3 and CORM-A1, and Hydrogen sulfide releasing system like GYY4137 have been discussed in this context. Therefore the relation of these trio-gasotransmitters with the ophthalmic homeostasis on one hand, and de-infecting role on the other hand has been mainly highlighted. Some molecular systems capable of mimicking gasotransmitter action have also been introduced in connection with the titled theme.
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Affiliation(s)
- Jan Mohammad Mir
- Coordination, Bioinorganic and Computational Chemistry Laboratory, Department of P.G. Studies and Research in Chemistry and Pharmacy , Rani Durgavati University , Jabalpur , M.P. , India
- Department of Chemistry , Islamic University of Science and Technology , Awantipora , J&K 192122 , India
| | - Ram Charitra Maurya
- Coordination, Bioinorganic and Computational Chemistry Laboratory, Department of P.G. Studies and Research in Chemistry and Pharmacy , Rani Durgavati University , Jabalpur , M.P. , India
| | - Mohd Washid Khan
- Coordination, Bioinorganic and Computational Chemistry Laboratory, Department of P.G. Studies and Research in Chemistry and Pharmacy , Rani Durgavati University , Jabalpur , M.P. , India
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Yamamoto K, Yamamoto R, Kato N. Amyloid β and Amyloid Precursor Protein Synergistically Suppress Large-Conductance Calcium-Activated Potassium Channel in Cortical Neurons. Front Aging Neurosci 2021; 13:660319. [PMID: 34149396 PMCID: PMC8211014 DOI: 10.3389/fnagi.2021.660319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/20/2021] [Indexed: 12/03/2022] Open
Abstract
Intracellular amyloid β (Aβ) injection suppresses the large-conductance calcium-dependent potassium (BK) channel in cortical pyramidal cells from wild-type (WT) mice. In 3xTg Alzheimer’s disease (AD) model mice, intraneuronal Aβ is genetically programed to accumulate, which suppresses the BK channel. However, the mode of BK channel suppression remained unclarified. The present report revealed that only one (11A1) of the three anti-Aβ-oligomer antibodies that we examined, but not anti-monomer-Aβ-antibodies, was effective in recovering BK channel activity in 3xTg neurons. Antibodies against amyloid precursor protein (APP) were also found to be effective, suggesting that APP plays an essential part in this Aβ-oligomer-induced BK channel suppression in 3xTg neurons. In WT neurons, by contrast, APP suppressed BK channels by itself, which suggests that either APP or Aβ is sufficient to block BK channels, thus pointing to a different co-operativity of Aβ and APP in WT and 3xTg neurons. To clarify this difference, we relied on our previous finding that the scaffold protein Homer1a reverses the BK channel blockade in both WT and 3xTg neurons. In cortical neurons from 3xTg mice that bear Homer1a knockout (4xTg mice), neither anti-APP antibodies nor 11A1, but only the 6E10 antibody that binds both APP and Aβ, rescued the BK channel suppression. Given that Homer1a expression is activity dependent and 3xTg neurons are hyperexcitable, Homer1a is likely to be expressed sufficiently in 3xTg neurons, thereby alleviating the suppressive influence of APP and Aβ on BK channel. A unique way that APP modifies Aβ toxicity is thus proposed.
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Affiliation(s)
- Kenji Yamamoto
- Department of Physiology, Kanazawa Medical University, Ishikawa, Japan.,Department of Neurology and Clinical Research Center, National Hospital Organization Utano National Hospital, Kyoto, Japan
| | - Ryo Yamamoto
- Department of Physiology, Kanazawa Medical University, Ishikawa, Japan
| | - Nobuo Kato
- Department of Physiology, Kanazawa Medical University, Ishikawa, Japan
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Mughal A, Sun C, O'Rourke ST. Apelin Does Not Impair Coronary Artery Relaxation Mediated by Nitric Oxide-Induced Activation of BK Ca Channels. Front Pharmacol 2021; 12:679005. [PMID: 34122102 PMCID: PMC8194342 DOI: 10.3389/fphar.2021.679005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 05/18/2021] [Indexed: 11/13/2022] Open
Abstract
Apelin-APJ receptor signaling regulates vascular tone in cerebral and peripheral arteries. We recently reported that apelin inhibits BKCa channel function in cerebral arteries, resulting in impaired endothelium-dependent relaxations. In contrast, apelin causes endothelium-dependent relaxation of coronary arteries. However, the effects of apelin on BKCa channel function in coronary arterial myocytes have not yet been explored. We hypothesized that apelin-APJ receptor signaling does not have an inhibitory effect on coronary arterial BKCa channels and hence does not alter nitric oxide (NO)-dependent relaxation of coronary arteries. Patch clamp recording was used to measure whole cell K+ currents in freshly isolated coronary smooth muscle cells. Apelin had no effect on the increases in current density in response to membrane depolarization or to NS1619 (a BKCa channel opener). Moreover, apelin did not inhibit NO/cGMP-dependent relaxations that required activation of BKCa channels in isolated coronary arteries. Apelin-APJ receptor signaling caused a marked increase in intracellular Ca2+ levels in coronary arterial smooth muscle cells, but failed to activate PI3-kinase to increase phosphorylation of Akt protein. Collectively, these data provide mechanistic evidence that apelin has no inhibitory effects on BKCa channel function in coronary arteries. The lack of inhibitory effect on BKCa channels makes it unlikely that activation of APJ receptors in coronary arteries would adversely affect coronary flow by creating a vasoconstrictive environment. It can be expected that apelin or other APJ receptor agonists in development will not interfere with the vasodilator effects of endogenous BKCa channel openers.
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Affiliation(s)
- Amreen Mughal
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND, United States
| | - Chengwen Sun
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND, United States
| | - Stephen T O'Rourke
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND, United States
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Sek A, Kampa RP, Kulawiak B, Szewczyk A, Bednarczyk P. Identification of the Large-Conductance Ca 2+-Regulated Potassium Channel in Mitochondria of Human Bronchial Epithelial Cells. Molecules 2021; 26:molecules26113233. [PMID: 34072205 PMCID: PMC8199365 DOI: 10.3390/molecules26113233] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/19/2021] [Accepted: 05/24/2021] [Indexed: 12/18/2022] Open
Abstract
Mitochondria play a key role in energy metabolism within the cell. Potassium channels such as ATP-sensitive, voltage-gated or large-conductance Ca2+-regulated channels have been described in the inner mitochondrial membrane. Several hypotheses have been proposed to describe the important roles of mitochondrial potassium channels in cell survival and death pathways. In the current study, we identified two populations of mitochondrial large-conductance Ca2+-regulated potassium (mitoBKCa) channels in human bronchial epithelial (HBE) cells. The biophysical properties of the channels were characterized using the patch-clamp technique. We observed the activity of the channel with a mean conductance close to 285 pS in symmetric 150/150 mM KCl solution. Channel activity was increased upon application of the potassium channel opener NS11021 in the micromolar concentration range. The channel activity was completely inhibited by 1 µM paxilline and 300 nM iberiotoxin, selective inhibitors of the BKCa channels. Based on calcium and iberiotoxin modulation, we suggest that the C-terminus of the protein is localized to the mitochondrial matrix. Additionally, using RT-PCR, we confirmed the presence of α pore-forming (Slo1) and auxiliary β3-β4 subunits of BKCa channel in HBE cells. Western blot analysis of cellular fractions confirmed the mitochondrial localization of α pore-forming and predominately β3 subunits. Additionally, the regulation of oxygen consumption and membrane potential of human bronchial epithelial mitochondria in the presence of the potassium channel opener NS11021 and inhibitor paxilline were also studied. In summary, for the first time, the electrophysiological and functional properties of the mitoBKCa channel in a bronchial epithelial cell line were described.
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Affiliation(s)
- Aleksandra Sek
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.S.); (R.P.K.); (B.K.); (A.S.)
- Faculty of Chemistry, University of Warsaw, 02-093 Warsaw, Poland
| | - Rafal P. Kampa
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.S.); (R.P.K.); (B.K.); (A.S.)
- Department of Physics and Biophysics, Institute of Biology, Warsaw University of Life Sciences—SGGW, 02-776 Warsaw, Poland
| | - Bogusz Kulawiak
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.S.); (R.P.K.); (B.K.); (A.S.)
| | - Adam Szewczyk
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.S.); (R.P.K.); (B.K.); (A.S.)
| | - Piotr Bednarczyk
- Department of Physics and Biophysics, Institute of Biology, Warsaw University of Life Sciences—SGGW, 02-776 Warsaw, Poland
- Correspondence: ; Tel.: +48-22-593-8620
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Petit-Pedrol M, Groc L. Regulation of membrane NMDA receptors by dynamics and protein interactions. J Cell Biol 2021; 220:211609. [PMID: 33337489 PMCID: PMC7754687 DOI: 10.1083/jcb.202006101] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 12/16/2022] Open
Abstract
Understanding neurotransmitter system crosstalk in the brain is a major challenge in neurobiology. Several intracellular and genomic cascades have been identified in this crosstalk. However, the discovery that neurotransmitter receptors are highly diffusive in the plasma membrane of neurons, where they form heterocomplexes with other proteins, has profoundly changed our view of neurotransmitter signaling. Here, we review new insights into neurotransmitter crosstalk at the plasma membrane. We focus on the membrane organization and interactome of the ionotropic glutamate N-methyl-D-aspartate receptor (NMDAR) that plays a central role in excitatory synaptic and network physiology and is involved in the etiology of several major neuropsychiatric disorders. The nanoscale organization and dynamics of NMDAR is a key regulatory process for glutamate synapse transmission, plasticity, and crosstalk with other neurotransmitter systems, such as the monoaminergic ones. The plasma membrane appears to be a prime regulatory compartment for spatial and temporal crosstalk between neurotransmitter systems in the healthy and diseased brain. Understanding the molecular mechanisms regulating membrane neurotransmitter receptor crosstalk will likely open research avenues for innovative therapeutical strategies.
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Affiliation(s)
- Mar Petit-Pedrol
- Université de Bordeaux, Centre National de la Recherche Scientifique, Interdisciplinary Institute for Neuroscience, Unité Mixte de Recherche 5297, Bordeaux, France
| | - Laurent Groc
- Université de Bordeaux, Centre National de la Recherche Scientifique, Interdisciplinary Institute for Neuroscience, Unité Mixte de Recherche 5297, Bordeaux, France
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Checchetto V, Leanza L, De Stefani D, Rizzuto R, Gulbins E, Szabo I. Mitochondrial K + channels and their implications for disease mechanisms. Pharmacol Ther 2021; 227:107874. [PMID: 33930454 DOI: 10.1016/j.pharmthera.2021.107874] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/12/2021] [Indexed: 02/06/2023]
Abstract
The field of mitochondrial ion channels underwent a rapid development during the last decade, thanks to the molecular identification of some of the nuclear-encoded organelle channels and to advances in strategies allowing specific pharmacological targeting of these proteins. Thereby, genetic tools and specific drugs aided definition of the relevance of several mitochondrial channels both in physiological as well as pathological conditions. Unfortunately, in the case of mitochondrial K+ channels, efforts of genetic manipulation provided only limited results, due to their dual localization to mitochondria and to plasma membrane in most cases. Although the impact of mitochondrial K+ channels on human diseases is still far from being genuinely understood, pre-clinical data strongly argue for their substantial role in the context of several pathologies, including cardiovascular and neurodegenerative diseases as well as cancer. Importantly, these channels are druggable targets, and their in-depth investigation could thus pave the way to the development of innovative small molecules with huge therapeutic potential. In the present review we summarize the available experimental evidence that mechanistically link mitochondrial potassium channels to the above pathologies and underline the possibility of exploiting them for therapy.
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Affiliation(s)
| | - Luigi Leanza
- Department of Biology, University of Padova, Italy
| | | | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Italy
| | - Erich Gulbins
- Department of Molecular Biology, University of Duisburg-Essen, Germany
| | - Ildiko Szabo
- Department of Biology, University of Padova, Italy; CNR Institute of Neurosciences, Italy.
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Sun WT, Xue HM, Hou HT, Chen HX, Wang J, He GW, Yang Q. Homocysteine alters vasoreactivity of human internal mammary artery by affecting the K Ca channel family. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:625. [PMID: 33987323 PMCID: PMC8106027 DOI: 10.21037/atm-20-6821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Background Hyperhomocysteinemia is an independent risk factor for atherosclerotic heart disease. We previously demonstrated that disruption of calcium-activated potassium (KCa) channel activity is involved in homocysteine-induced dilatory dysfunction of porcine coronary arteries. Recently we reported that the KCa channel family, including large-, intermediate-, and small-conductance KCa (BKCa, IKCa, and SKCa) subtypes, are abundantly expressed in human internal mammary artery (IMA). In this study, we further investigated whether homocysteine affects the expression and functionality of the KCa channel family in this commonly used graft for coronary artery bypass surgery (CABG). Methods Residual IMA segments obtained from patients undergoing CABG were studied in a myograph for the role of KCa subtypes in both vasorelaxation and vasoconstriction. The expression and distribution of KCa subtypes were detected by Western blot and immunohistochemistry. Results Both the BKCa channel activator NS1619 and the IKCa/SKCa channel activator NS309 evoked significant IMA relaxation. Homocysteine exposure suppressed NS1619-induced relaxation whereas showed no influence on NS309-induced response. Blockade of BKCa but not IKCa and SKCa subtypes significantly suppressed acetylcholine-induced relaxation and enhanced U46619-induced contraction. Homocysteine compromised the vasodilating activity of the BKCa subtype in IMA, associated with a lowered protein level of the BKCa β1-subunit. Homocysteine potentiated the role of IKCa and SKCa subtypes in mediating endothelium-dependent relaxation without affecting the expression of these channels. Conclusions Homocysteine reduces the expression of BKCa β1-subunit and compromises the vasodilating activity of BKCa channels in IMA. Unlike BKCa, IKCa and SKCa subtypes are unessential for IMA vasoregulation, whereas the loss of BKCa functionality in hyperhomocysteinemia enhances the role of IKCa and SKCa subtypes in mediating endothelial dilator function. Targeting BKCa channels may form a strategy to improve the postoperative graft performance in CABG patients with hyperhomocysteinemia who receive IMA grafting.
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Affiliation(s)
- Wen-Tao Sun
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China.,School of Medicine, Nankai University, Tianjin, China
| | - Hong-Mei Xue
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China.,School of Medicine, Nankai University, Tianjin, China.,Department of Physiology, Hebei Medical University, Shijiazhuang, China
| | - Hai-Tao Hou
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Huan-Xin Chen
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Jun Wang
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Guo-Wei He
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China.,School of Pharmacy, Wannan Medical College, Wuhu, China.,Department of Surgery, Oregon Health and Science University, Portland, Oregon, USA
| | - Qin Yang
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
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Inhibitory Effects of Genistein on Vascular Smooth Muscle Cell Proliferation Induced by Ox-LDL: Role of BKCa Channels. ACTA ACUST UNITED AC 2021; 2020:8895449. [PMID: 33415067 PMCID: PMC7752275 DOI: 10.1155/2020/8895449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 12/04/2020] [Indexed: 11/23/2022]
Abstract
Background Oxidized low-density lipoprotein (Ox-LDL) is a crucial pathogenic factor for vascular diseases, which can induce the proliferation of vascular smooth muscle cells (VSMCs). Genistein is the main component of soybean isoflavone. Genistein has a variety of pharmacological properties in the treatment of vascular diseases and a promising clinical application. Large-conductance calcium-activated potassium (BKCa) channels are the primary type of potassium channels in VSMCs, which regulate various biological functions of VSMCs. However, whether genistein exerts an antiproliferation effect on Ox-LDL-stimulated VSMCs remains unclear. The current study is aimed at elucidating the effect of genistein on the Ox-LDL-stimulated proliferation of VSMCs and its possible molecular mechanism, especially the electrophysiological mechanism related to BKCa channels. Methods Monoculture VSMC was obtained by an acute enzyme-dispersing method. The proliferation of cells was measured by CCK-8, cell cycle, and proliferating cell nuclear antigen (PCNA) expression. The BKCa whole-cell currents were measured by patch-clamp. Results Ox-LDL treatment induced the proliferation of VSMCs, upregulated the BKCa protein expression, and increased the density of BKCa currents, while genistein significantly inhibited these effects caused by Ox-LDL. BKCa channels exerted a regulatory role in the proliferation of VSMCs in response to Ox-LDL. The inhibition of BKCa channels suppressed Ox-LDL-stimulated VSMC proliferation, while the activation of BKCa channels showed the opposite effect. Moreover, genistein suppressed the activity of BKCa, including protein expression and current density in a protein tyrosine kinase- (PTK-) dependent manner. Conclusion This study demonstrated that genistein inhibited the Ox-LDL-mediated proliferation of VSMCs by blocking the cell cycle progression; the possible molecular mechanism may be related to PTK-dependent suppression of BKCa channels. Our results provided novel ideas for the application of genistein in the treatment of vascular diseases and proposed a unique insight into the antiproliferative molecular mechanism of genistein.
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33
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Wu T, Yin N, Chen X, Huang H, Liao Y. Functional coupling between BKCa and SOC channels. Tissue Cell 2020; 66:101394. [DOI: 10.1016/j.tice.2020.101394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 05/31/2020] [Accepted: 05/31/2020] [Indexed: 01/13/2023]
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Xu J, Ma HH, Liu ZM, Zheng W, Lai XY, Zhu H, Liu J, Zhou Y, Zhou XM. Expression and alternative splicing analysis of a large-conductance calcium-activated potassium channel gene in Plutella xylostella. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2020; 105:e21720. [PMID: 32557681 DOI: 10.1002/arch.21720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 06/11/2023]
Abstract
The large-conductance calcium-activated potassium channel (BKCa ) plays an important role in the regulation of insect neural circuits and locomotion, and thus is a potential target of insecticides. In this study, iberiotoxin, an inhibitor of BKCa , was found to prolong the anesthetic time of ethyl acetate on Plutella xylostella larvae. Therefore, the coding sequence of slowpoke gene coding the alpha subunit of BKCa was cloned to investigate the function of this channel in P. xylostella, and the gene expression profile in the developmental stages and tissues was also characterized. The total length of pxslo DNA was more than 19.9 kb, which harbored four alternative splicing sites (ASP-A, ASP-C, ASP-E, and ASP-G), and the coding sequence of pxslo with the highest frequency of splicing (GenBank ID: MN938456) was 3,405 base pair. The characterized PxSlo protein contained conserved domains previously identified in other insects. Quantitative reverse transcription-polymerase chain reaction analysis showed that pxslo was expressed in all the developmental stages of P. xylostella, with the highest level in adults. In the larval stage, pxslo was mainly expressed in the head and epidermis, while a limited protein was expressed in the midgut. In the adult stage, pxslo was highly expressed in the head, followed by in the ovarian tubule, and was not expressed in the testis or wings. These results suggest that BKCa plays an important physiological role in P. xylostella and provides useful information for the functional study and screening of BKCa inhibitors.
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Affiliation(s)
- Jie Xu
- College of Plant Protection, Graduate School of Hunan Agricultural University, Changsha, China
| | - Hai-Hao Ma
- Hunan Agricultural Biotechnology Research Institute, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Zhe-Ming Liu
- Hunan Agricultural Biotechnology Research Institute, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Wei Zheng
- Hunan Agricultural Biotechnology Research Institute, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Xiao-Yi Lai
- Hunan Agricultural Biotechnology Research Institute, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Hang Zhu
- Hunan Agricultural Biotechnology Research Institute, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Jia Liu
- Hunan Agricultural Biotechnology Research Institute, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Yong Zhou
- Hunan Agricultural Biotechnology Research Institute, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Xiao-Mao Zhou
- College of Plant Protection, Graduate School of Hunan Agricultural University, Changsha, China
- Hunan Agricultural Biotechnology Research Institute, Hunan Academy of Agricultural Sciences, Changsha, China
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Clinical Importance of the Human Umbilical Artery Potassium Channels. Cells 2020; 9:cells9091956. [PMID: 32854241 PMCID: PMC7565333 DOI: 10.3390/cells9091956] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/21/2020] [Accepted: 08/24/2020] [Indexed: 02/06/2023] Open
Abstract
Potassium (K+) channels are usually predominant in the membranes of vascular smooth muscle cells (SMCs). These channels play an important role in regulating the membrane potential and vessel contractility-a role that depends on the vascular bed. Thus, the activity of K+ channels represents one of the main mechanisms regulating the vascular tone in physiological and pathophysiological conditions. Briefly, the activation of K+ channels in SMC leads to hyperpolarization and vasorelaxation, while its inhibition induces depolarization and consequent vascular contraction. Currently, there are four different types of K+ channels described in SMCs: voltage-dependent K+ (KV) channels, calcium-activated K+ (KCa) channels, inward rectifier K+ (Kir) channels, and 2-pore domain K+ (K2P) channels. Due to the fundamental role of K+ channels in excitable cells, these channels are promising therapeutic targets in clinical practice. Therefore, this review discusses the basic properties of the various types of K+ channels, including structure, cellular mechanisms that regulate their activity, and new advances in the development of activators and blockers of these channels. The vascular functions of these channels will be discussed with a focus on vascular SMCs of the human umbilical artery. Then, the clinical importance of K+ channels in the treatment and prevention of cardiovascular diseases during pregnancy, such as gestational hypertension and preeclampsia, will be explored.
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Lozano Jiménez YY, Sánchez Mora RM. Canales de calcio como blanco de interés farmacológico. NOVA 2020. [DOI: 10.22490/24629448.3926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Los canales de calcio son proteínas de membrana que constituyen la vía más importante para el ingreso del ion calcio (Ca2+) a la célula. Al abrirse, permiten el ingreso selectivo del ion, iniciando una variedad de procesos como contracción muscular, secreción endocrina y liberación de neurotransmisores, entre otros. Estas proteínas se agrupan en tres categorías de acuerdo con sus propiedades estructurales y funcionales: (i) Canales de Ca2+ operados por interacción receptor-ligando (ROCC), (ii) Canales activados por parámetros físicos (Transient Receptor Potencial, TRP) y (iii) Canales de Calcio dependientes de voltaje (VDCCs), siendo estos últimos los más estudiados debido a su presencia en células excitables. Dada la importancia de Ca2+ en la fisiología celular, los canales de Ca2+ constituyen un punto de acción farmacológica importante para múltiples tratamientos y, por tanto, son objeto de estudio para el desarrollo de nuevos fármacos. El objetivo de esta revisión es explicar la importancia de los canales de Ca2+ desde una proyección farmacológica, a partir de la exploración documental de artículos publicados hasta la fecha teniendo en cuenta temas relacionados con la estructura de los canales Ca2+, sus propiedades biofísicas, localización celular, funcionamiento y su interacción farmacológica.
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The Role of MicroRNA in the Airway Surface Liquid Homeostasis. Int J Mol Sci 2020; 21:ijms21113848. [PMID: 32481719 PMCID: PMC7312818 DOI: 10.3390/ijms21113848] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 05/24/2020] [Accepted: 05/25/2020] [Indexed: 02/06/2023] Open
Abstract
Mucociliary clearance, mediated by a coordinated function of cilia bathing in the airway surface liquid (ASL) on the surface of airway epithelium, protects the host from inhaled pathogens and is an essential component of the innate immunity. ASL is composed of the superficial mucus layer and the deeper periciliary liquid. Ion channels, transporters, and pumps coordinate the transcellular and paracellular movement of ions and water to maintain the ASL volume and mucus hydration. microRNA (miRNA) is a class of non-coding, short single-stranded RNA regulating gene expression by post-transcriptional mechanisms. miRNAs have been increasingly recognized as essential regulators of ion channels and transporters responsible for ASL homeostasis. miRNAs also influence the airway host defense. We summarize the most up-to-date information on the role of miRNAs in ASL homeostasis and host-pathogen interactions in the airway and discuss concepts for miRNA-directed therapy.
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Trombetta-Lima M, Krabbendam IE, Dolga AM. Calcium-activated potassium channels: implications for aging and age-related neurodegeneration. Int J Biochem Cell Biol 2020; 123:105748. [PMID: 32353429 DOI: 10.1016/j.biocel.2020.105748] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/11/2020] [Accepted: 04/14/2020] [Indexed: 12/16/2022]
Abstract
Population aging, as well as the handling of age-associated diseases, is a worldwide increasing concern. Among them, Alzheimer's disease stands out as the major cause of dementia culminating in full dependence on other people for basic functions. However, despite numerous efforts, in the last decades, there was no new approved therapeutic drug for the treatment of the disease. Calcium-activated potassium channels have emerged as a potential tool for neuronal protection by modulating intracellular calcium signaling. Their subcellular localization is determinant of their functional effects. When located on the plasma membrane of neuronal cells, they can modulate synaptic function, while their activation at the inner mitochondrial membrane has a neuroprotective potential via the attenuation of mitochondrial reactive oxygen species in conditions of oxidative stress. Here we review the dual role of these channels in the aging phenotype and Alzheimer's disease pathology and discuss their potential use as a therapeutic tool.
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Affiliation(s)
- Marina Trombetta-Lima
- Faculty of Science and Engineering, Department of Molecular Pharmacology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, 9713 AV Groningen, the Netherlands; Medical School, Neurology Department, University of São Paulo (USP), 01246903 São Paulo, Brazil
| | - Inge E Krabbendam
- Faculty of Science and Engineering, Department of Molecular Pharmacology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, 9713 AV Groningen, the Netherlands
| | - Amalia M Dolga
- Faculty of Science and Engineering, Department of Molecular Pharmacology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, 9713 AV Groningen, the Netherlands.
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Coskun C, Buyuknacar HS, Cicek F, Gunay I. BK channel openers NS1619 and NS11021 reverse hydrogen peroxide-induced membrane potential changes in skeletal muscle. J Recept Signal Transduct Res 2020; 40:449-455. [PMID: 32326798 DOI: 10.1080/10799893.2020.1756324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Large conductance calcium-activated potassium (BK) channels play a crucial role in the repolarization and after-hyperpolarization phases of the cell membrane. The channel openers are also used in treatment of some diseases, including hypo/hyperkalemic periodic paralysis. However, little is known about the effects of BK channels and the channel activators on membrane potentials in skeletal muscle. In addition, the effects of reactive oxygen species (ROS) on BK channels in skeletal muscle are also unknown. Therefore, the aim of this study was to determine the effects of BK channel openers and ROS on membrane potentials in skeletal muscle fibers. For this purpose, resting membrane potentials and action potentials (AP) of frog gastrocnemius muscles were recorded in the presence of commonly used BK channel openers NS1619 and NS11021, H2O2 (a type of ROS), and both using intracellular microelectrode technique. The channel activators significantly and dose-dependently decreased amplitude and increased rise time of AP but did not impact repolarization. The presence of H2O2 plus NS1619 or NS11021 resulted in significant change because the channel openers completely reversed the deleterious effects of hydrogen peroxide on the repolarization phase of AP in skeletal muscle fibers. In the present study, the contributions of BK channel activation and the modulatory role of H2O2 on membrane potentials was demonstrated in skeletal muscle fibers, for the first time. Moreover, it should be noted that BK channel openers should be used in the treatment of reactive oxygen species-induced skeletal muscle diseases.
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Affiliation(s)
- Cagil Coskun
- Department of Biophysics, Faculty of Medicine, Cukurova University, Adana, Turkey
| | | | - Figen Cicek
- Department of Biophysics, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Ismail Gunay
- Department of Biophysics, Faculty of Medicine, Cukurova University, Adana, Turkey
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40
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Shi R, Xu JW, Xiao ZT, Chen RF, Zhang YL, Lin JB, Cheng KL, Wei GY, Li PB, Zhou WL, Su WW. Naringin and Naringenin Relax Rat Tracheal Smooth by Regulating BK Ca Activation. J Med Food 2019; 22:963-970. [PMID: 31259654 DOI: 10.1089/jmf.2018.4364] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Naringin and its aglycone, naringenin, occur naturally in our regular diet and traditional Chinese medicines. This study aimed to detect an effective therapeutic approach for cough variant asthma (CVA) through evaluating the relaxant effect of these two bioactive herbal monomers as antitussive and antiasthmatic on rat tracheal smooth muscle. The relaxant effect was determined by measuring muscular tension with a mechanical recording system in rat tracheal rings. Cytosolic Ca2+ concentration was measured using a confocal imaging system in primary cultured tracheal smooth muscle cells. In rat tracheal rings, addition of both naringin and naringenin could concentration dependently relax carbachol (CCh)-evoked tonic contraction. This epithelium-independent relaxation could be suppressed by BaCl2, tetraethylammonium, and iberiotoxin (IbTX), but not by glibenclamide. After stimulating primary cultured tracheal smooth muscle cells by CCh or high KCl, the intracellular Ca2+ increase could be inhibited by both naringin and naringenin, respectively. This reaction was also suppressed by IbTX. These results demonstrate that both naringin and naringenin can relax tracheal smooth muscle through opening big conductance Ca2+-activated K+ channel, which mediates plasma membrane hyperpolarization and reduces Ca2+ influx. Our data indicate a potentially effective therapeutic approach of naringin and naringenin for CVA.
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Affiliation(s)
- Rui Shi
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jia-Wen Xu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zi-Ting Xiao
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Ruo-Fei Chen
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yi-Lin Zhang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jia-Bi Lin
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Ke-Ling Cheng
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Gu-Yi Wei
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Pei-Bo Li
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wen-Liang Zhou
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wei-Wei Su
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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41
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24S-hydroxycholesterol alters activity of large-conductance Ca 2+-dependent K + (slo1 BK) channel through intercalation into plasma membrane. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:1525-1535. [PMID: 31136842 DOI: 10.1016/j.bbalip.2019.05.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 05/11/2019] [Accepted: 05/20/2019] [Indexed: 11/24/2022]
Abstract
Oxysterols, oxidization products of cholesterol, are regarded as bioactive lipids affecting various physiological functions. However, little is known of their effects on ion channels. Using inside-out patch clamp recording, we found that naturally occurring side-chain oxidized oxysterols, 20S‑hydroxycholesterol, 22R‑hydroxycholesterol, 24S‑hydroxycholestero, 25‑hydroxycholesterol, and 27‑hydroxycholesterol, induced current reduction of large-conductance Ca2+- and voltage-activated K+ (slo1 BK) channels heterologously expressed in HEK293T cells. In contrast with side-chain oxidized oxysterols, naturally occurring ring oxidized ones, 7α‑hydroxycholesterol and 7‑ketocholesterol were without effect. By using 24S‑hydroxycholesterol (24S‑HC), the major brain oxysterol, we explored the inhibition mechanism. 24S‑HC inhibited Slo1 BK channels with an IC50 of ~2 μM, and decreased macroscopic current by ~60%. This marked current decrease was accompanied by a rightward shift in the conductance-voltage relationship and a slowed activation kinetics, with the deactivation kinetics unaltered. Furthermore, the membrane sterol scavenger γ‑cyclodextrin was found to rescue slo1 BK channels from the inhibition, implicating that 24S-HC may be intercalated into the plasma membrane to affect the channel. These findings unveil a novel physiological importance of oxysterols from a new angle that involves ion channel regulation.
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42
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Gupta S, Manchanda R. A computational model of large conductance voltage and calcium activated potassium channels: implications for calcium dynamics and electrophysiology in detrusor smooth muscle cells. J Comput Neurosci 2019; 46:233-256. [PMID: 31025235 DOI: 10.1007/s10827-019-00713-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 02/14/2019] [Accepted: 02/19/2019] [Indexed: 11/25/2022]
Abstract
The large conductance voltage and calcium activated potassium (BK) channels play a crucial role in regulating the excitability of detrusor smooth muscle, which lines the wall of the urinary bladder. These channels have been widely characterized in terms of their molecular structure, pharmacology and electrophysiology. They control the repolarising and hyperpolarising phases of the action potential, thereby regulating the firing frequency and contraction profiles of the smooth muscle. Several groups have reported varied profiles of BK currents and I-V curves under similar experimental conditions. However, no single computational model has been able to reconcile these apparent discrepancies. In view of the channels' physiological importance, it is imperative to understand their mechanistic underpinnings so that a realistic model can be created. This paper presents a computational model of the BK channel, based on the Hodgkin-Huxley formalism, constructed by utilising three activation processes - membrane potential, calcium inflow from voltage-gated calcium channels on the membrane and calcium released from the ryanodine receptors present on the sarcoplasmic reticulum. In our model, we attribute the discrepant profiles to the underlying cytosolic calcium received by the channel during its activation. The model enables us to make heuristic predictions regarding the nature of the sub-membrane calcium dynamics underlying the BK channel's activation. We have employed the model to reproduce various physiological characteristics of the channel and found the simulated responses to be in accordance with the experimental findings. Additionally, we have used the model to investigate the role of this channel in electrophysiological signals, such as the action potential and spontaneous transient hyperpolarisations. Furthermore, the clinical effects of BK channel openers, mallotoxin and NS19504, were simulated for the detrusor smooth muscle cells. Our findings support the proposed application of these drugs for amelioration of the condition of overactive bladder. We thus propose a physiologically realistic BK channel model which can be integrated with other biophysical mechanisms such as ion channels, pumps and exchangers to further elucidate its micro-domain interaction with the intracellular calcium environment.
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Affiliation(s)
- Suranjana Gupta
- Computational NeuroPhysiology Lab, Department of Biosciences and Bioengineering, IIT Bombay, Powai, Mumbai, 400076, India
| | - Rohit Manchanda
- Computational NeuroPhysiology Lab, Department of Biosciences and Bioengineering, IIT Bombay, Powai, Mumbai, 400076, India.
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43
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Wen J, Li P, Cheng J, Wang N, Mao L, Tan X, Zeng X, Xia D, Zhou Y, Yang Q, Yang Y. Downregulation of AT 2R decreases the responsiveness of BK Ca channels to angiotensin II in patients with hypertension. J Mol Cell Cardiol 2019; 131:20-28. [PMID: 30998981 DOI: 10.1016/j.yjmcc.2019.04.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/27/2019] [Accepted: 04/12/2019] [Indexed: 01/23/2023]
Abstract
Angiotensin II (Ang II) modulates blood pressure via Ang II type 1 receptor (AT1R) and type 2 receptor (AT2R). The activation of AT2R relaxes vascular tone through opening large-conductance Ca2+-activated potassium (BKCa) channels in vascular smooth muscle cells (SMCs). In the present study, we studied the role of the AT2R-BKCa pathway in patients with hypertension. The mesenteric arterial SMCs (MSMCs) were obtained from normotensive patients (NP) and hypertensive patients (HP). BKCa currents were recorded with patch clamp and the expressions of mRNAs and proteins of AT1R/AT2R were analyzed by RT-PCR and Western blotting, respectively. Ang II significantly increased the macroscopic BKCa currents at the whole cell level, while increased the open probability and decreased the mean close time of BKCa channels at the single channel level with AT1R blockade by valsartan in NP. However, Ang II had no effect on the BKCa currents at the same condition in HP. Furthermore, the expressions of mRNA and protein of AT2R but not AT1R were markedly decreased in the MSMCs of HP compared to that of NP. The data suggest that AT2R is well functioned in the MSMCs in NP but not in HP and deficiency in the AT2R-BKCa pathway may contribute to the development of hypertension.
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Affiliation(s)
- Jing Wen
- Key Lab of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Lab of Sichuan Province, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Pengyun Li
- Key Lab of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Lab of Sichuan Province, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Jun Cheng
- Key Lab of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Lab of Sichuan Province, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Na Wang
- Key Lab of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Lab of Sichuan Province, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Liang Mao
- Key Lab of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Lab of Sichuan Province, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Xiaoqiu Tan
- Key Lab of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Lab of Sichuan Province, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Xiaorong Zeng
- Key Lab of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Lab of Sichuan Province, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Dong Xia
- The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Yejiang Zhou
- The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Qingqiang Yang
- The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Yan Yang
- Key Lab of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Lab of Sichuan Province, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan 646000, China.
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44
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Calcium oscillations coordinate feather mesenchymal cell movement by SHH dependent modulation of gap junction networks. Nat Commun 2018; 9:5377. [PMID: 30560870 PMCID: PMC6299091 DOI: 10.1038/s41467-018-07661-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 11/14/2018] [Indexed: 12/30/2022] Open
Abstract
Collective cell migration mediates multiple tissue morphogenesis processes. Yet how multi-dimensional mesenchymal cell movements are coordinated remains mostly unknown. Here we report that coordinated mesenchymal cell migration during chicken feather elongation is accompanied by dynamic changes of bioelectric currents. Transcriptome profiling and functional assays implicate contributions from functional voltage-gated Ca2+ channels (VGCCs), Connexin-43 based gap junctions, and Ca2+ release activated Ca2+ (CRAC) channels. 4-Dimensional Ca2+ imaging reveals that the Sonic hedgehog-responsive mesenchymal cells display synchronized Ca2+ oscillations, which expand progressively in area during feather elongation. Inhibiting VGCCs, gap junctions, or Sonic hedgehog signaling alters the mesenchymal Ca2+ landscape, cell movement patterns and feather bud elongation. Ca2+ oscillations induced by cyclic activation of opto-cCRAC channels enhance feather bud elongation. Functional disruption experiments and promoter analysis implicate synergistic Hedgehog and WNT/β-Catenin signaling in activating Connexin-43 expression, establishing gap junction networks synchronizing the Ca2+ profile among cells, thereby coordinating cell movement patterns. The molecular mechanisms regulating mesenchymal cell movements are unclear. Here, the authors show in chicken feather elongation that SHH/WNT signalling establishes gap-junctions, enabling synchronized Ca2 + oscillations to emerge for and in turn coordinating directed cell migration.
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45
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Soloviev AI, Kizub IV. Mechanisms of vascular dysfunction evoked by ionizing radiation and possible targets for its pharmacological correction. Biochem Pharmacol 2018; 159:121-139. [PMID: 30508525 DOI: 10.1016/j.bcp.2018.11.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/28/2018] [Indexed: 12/20/2022]
Abstract
Ionizing radiation (IR) leads to a variety of the cardiovascular diseases, including the arterial hypertension. A number of studies have demonstrated that blood vessels represent important target for IR, and the endothelium is one of the most vulnerable components of the vascular wall. IR causes an inhibition of nitric oxide (NO)-mediated endothelium-dependent vasodilatation and generation of reactive oxygen (ROS) and nitrogen (RNS) species trigger this process. Inhibition of NO-mediated vasodilatation could be due to endothelial NO synthase (eNOS) down-regulation, inactivation of endothelium-derived NO, and abnormalities in diffusion of NO from the endothelial cells (ECs) leading to a decrease in NO bioavailability. Beside this, IR suppresses endothelial large conductance Ca2+-activated K+ channels (BKCa) activity, which control NO synthesis. IR also leads to inhibition of the BKCa current in vascular smooth muscle cells (SMCs) which is mediated by protein kinase C (PKC). On the other hand, IR-evoked enhanced vascular contractility may result from PKC-mediated increase in SMCs myofilament Ca2+ sensitivity. Also, IR evokes vascular wall inflammation and atherosclerosis development. Vascular function damaged by IR can be effectively restored by quercetin-filled phosphatidylcholine liposomes and mesenchymal stem cells injection. Using RNA-interference technique targeted to different PKC isoforms can also be a perspective approach for pharmacological treatment of IR-induced vascular dysfunction.
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Affiliation(s)
- Anatoly I Soloviev
- Department of Pharmacology of Cellular Signaling Systems and Experimental Therapy, Institute of Pharmacology and Toxicology, National Academy of Medical Sciences of Ukraine, 14 Eugene Pottier Street, Kiev 03068, Ukraine
| | - Igor V Kizub
- Department of Pharmacology, New York Medical College, 15 Dana Road, Valhalla 10595, NY, United States.
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46
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Abstract
The large-conductance calcium- and voltage-activated K+ (BK) channel has a requirement of high intracellular free Ca2+ concentrations for its activation in neurons under physiological conditions. The Ca2+ sources for BK channel activation are not well understood. In this study, we showed by coimmunopurification and colocalization analyses that BK channels form complexes with NMDA receptors (NMDARs) in both rodent brains and a heterologous expression system. The BK-NMDAR complexes are broadly present in different brain regions. The complex formation occurs between the obligatory BKα and GluN1 subunits likely via a direct physical interaction of the former's intracellular S0-S1 loop with the latter's cytosolic regions. By patch-clamp recording on mouse brain slices, we observed BK channel activation by NMDAR-mediated Ca2+ influx in dentate gyrus granule cells. BK channels modulate excitatory synaptic transmission via functional coupling with NMDARs at postsynaptic sites of medial perforant path-dentate gyrus granule cell synapses. A synthesized peptide of the BKα S0-S1 loop region, when loaded intracellularly via recording pipette, abolished the NMDAR-mediated BK channel activation and effect on synaptic transmission. These findings reveal the broad expression of the BK-NMDAR complexes in brain, the potential mechanism underlying the complex formation, and the NMDAR-mediated activation and function of postsynaptic BK channels in neurons.
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47
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Xiang R, McNally J, Bond J, Tucker D, Cameron M, Donaldson AJ, Austin KL, Rowe S, Jonker A, Pinares-Patino CS, McEwan JC, Vercoe PE, Oddy VH, Dalrymple BP. Across-Experiment Transcriptomics of Sheep Rumen Identifies Expression of Lipid/Oxo-Acid Metabolism and Muscle Cell Junction Genes Associated With Variation in Methane-Related Phenotypes. Front Genet 2018; 9:330. [PMID: 30177952 PMCID: PMC6109778 DOI: 10.3389/fgene.2018.00330] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Accepted: 07/31/2018] [Indexed: 01/03/2023] Open
Abstract
Ruminants are significant contributors to the livestock generated component of the greenhouse gas, methane (CH4). The CH4 is primarily produced by the rumen microbes. Although the composition of the diet and animal intake amount have the largest effect on CH4 production and yield (CH4 production/dry matter intake, DMI), the host also influences CH4 yield. Shorter rumen feed mean retention time (MRT) is associated with higher dry matter intake and lower CH4 yield, but the molecular mechanism(s) by which the host affects CH4 production remain unclear. We integrated rumen wall transcriptome data and CH4 phenotypes from two independent experiments conducted with sheep in Australia (AUS, n = 62) and New Zealand (NZ, n = 24). The inclusion of the AUS data validated the previously identified clusters and gene sets representing rumen epithelial, metabolic and muscular functions. In addition, the expression of the cell cycle genes as a group was consistently positively correlated with acetate and butyrate concentrations (p < 0.05, based on AUS and NZ data together). The expression of a group of metabolic genes showed positive correlations in both AUS and NZ datasets with CH4 production (p < 0.05) and yield (p < 0.01). These genes encode key enzymes in the ketone body synthesis pathway and included members of the poorly characterized aldo-keto reductase 1C (AKR1C) family. Several AKR1C family genes appear to have ruminant specific evolution patterns, supporting their specialized roles in the ruminants. Combining differential gene expression in the rumen wall muscle of the shortest and longest MRT AUS animals (no data available for the NZ animals) with correlation and network analysis, we identified a set of rumen muscle genes involved in cell junctions as potential regulators of MRT, presumably by influencing contraction rates of the smooth muscle component of the rumen wall. Higher rumen expression of these genes, including SYNPO (synaptopodin, p < 0.01) and NEXN (nexilin, p < 0.05), was associated with lower CH4 yield in both AUS and NZ datasets. Unlike the metabolic genes, the variations in the expression of which may reflect the availability of rumen metabolites, the muscle genes are currently our best candidates for causal genes that influence CH4 yield.
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Affiliation(s)
- Ruidong Xiang
- CSIRO Agriculture & Food, Queensland Bioscience Precinct, St Lucia, QLD, Australia.,Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia.,Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC, Australia
| | - Jody McNally
- F. D. McMaster Laboratory, CSIRO Agriculture & Food, Armidale, NSW, Australia
| | - Jude Bond
- NSW Department of Primary Industries, Extensive Livestock Industries Centre, University of New England, Armidale, NSW, Australia
| | - David Tucker
- NSW Department of Primary Industries, Extensive Livestock Industries Centre, University of New England, Armidale, NSW, Australia
| | - Margaret Cameron
- NSW Department of Primary Industries, Extensive Livestock Industries Centre, University of New England, Armidale, NSW, Australia
| | - Alistair J Donaldson
- NSW Department of Primary Industries, Extensive Livestock Industries Centre, University of New England, Armidale, NSW, Australia
| | - Katie L Austin
- NSW Department of Primary Industries, Extensive Livestock Industries Centre, University of New England, Armidale, NSW, Australia
| | - Suzanne Rowe
- Invermay Agricultural Centre, AgResearch Limited, Mosgiel, New Zealand
| | - Arjan Jonker
- Grasslands Research Centre, AgResearch Limited, Palmerston North, New Zealand
| | - Cesar S Pinares-Patino
- Grasslands Research Centre, AgResearch Limited, Palmerston North, New Zealand.,New Zealand-Peru Dairy Support Project, MINAGRI, Lima, Peru
| | - John C McEwan
- Invermay Agricultural Centre, AgResearch Limited, Mosgiel, New Zealand
| | - Phil E Vercoe
- School of Animal Biology, The University of Western Australia, Crawley, WA, Australia.,Institute of Agriculture, The University of Western Australia, Crawley, WA, Australia
| | - V H Oddy
- NSW Department of Primary Industries, Extensive Livestock Industries Centre, University of New England, Armidale, NSW, Australia
| | - Brian P Dalrymple
- CSIRO Agriculture & Food, Queensland Bioscience Precinct, St Lucia, QLD, Australia.,Institute of Agriculture, The University of Western Australia, Crawley, WA, Australia
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48
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Cellular function given parametric variation in the Hodgkin and Huxley model of excitability. Proc Natl Acad Sci U S A 2018; 115:E8211-E8218. [PMID: 30111538 PMCID: PMC6126753 DOI: 10.1073/pnas.1808552115] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
How is reliable physiological function maintained in cells despite considerable variability in the values of key parameters of multiple interacting processes that govern that function? Here, we use the classic Hodgkin-Huxley formulation of the squid giant axon action potential to propose a possible approach to this problem. Although the full Hodgkin-Huxley model is very sensitive to fluctuations that independently occur in its many parameters, the outcome is in fact determined by simple combinations of these parameters along two physiological dimensions: structural and kinetic (denoted S and K, respectively). Structural parameters describe the properties of the cell, including its capacitance and the densities of its ion channels. Kinetic parameters are those that describe the opening and closing of the voltage-dependent conductances. The impacts of parametric fluctuations on the dynamics of the system-seemingly complex in the high-dimensional representation of the Hodgkin-Huxley model-are tractable when examined within the S-K plane. We demonstrate that slow inactivation, a ubiquitous activity-dependent feature of ionic channels, is a powerful local homeostatic control mechanism that stabilizes excitability amid changes in structural and kinetic parameters.
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49
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Bussey CE, Withers SB, Saxton SN, Bodagh N, Aldous RG, Heagerty AM. β 3 -Adrenoceptor stimulation of perivascular adipocytes leads to increased fat cell-derived NO and vascular relaxation in small arteries. Br J Pharmacol 2018; 175:3685-3698. [PMID: 29980164 PMCID: PMC6109217 DOI: 10.1111/bph.14433] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 05/04/2018] [Accepted: 06/19/2018] [Indexed: 01/13/2023] Open
Abstract
Background and Purpose In response to noradrenaline, healthy perivascular adipose tissue (PVAT) exerts an anticontractile effect on adjacent small arterial tissue. Organ bath solution transfer experiments have demonstrated the release of PVAT‐derived relaxing factors that mediate this function. The present studies were designed to investigate the mechanism responsible for the noradrenaline‐induced PVAT anticontractile effect. Experimental Approach In vitro rat small arterial contractile function was assessed using wire myography in the presence and absence of PVAT and the effects of sympathomimetic stimulation on the PVAT environment explored using Western blotting and assays of organ bath buffer. Key Results PVAT elicited an anticontractile effect in response to noradrenaline but not phenylephrine stimulation. In arteries surrounded by intact PVAT, the β3‐adrenoceptor agonist, CL‐316243, reduced the vasoconstrictor effect of phenylephrine but not noradrenaline. Kv7 channel inhibition using XE 991 reversed the noradrenaline‐induced anticontractile effect in exogenously applied PVAT studies. Adrenergic stimulation of PVAT with noradrenaline and CL‐316243, but not phenylephrine, was associated with increased adipocyte‐derived NO production, and the contractile response to noradrenaline was augmented following incubation of exogenous PVAT with L‐NMMA. PVAT from eNOS−/− mice had no anticontractile effect. Assays of adipocyte cAMP demonstrated an increase with noradrenaline stimulation implicating Gαs signalling in this process. Conclusions and Implications We have shown that adipocyte‐located β3‐adrenoceptor stimulation leads to activation of Gαs signalling pathways with increased cAMP and the release of adipocyte‐derived NO. This process is dependent upon Kv7 channel function. We conclude that adipocyte‐derived NO plays a central role in anticontractile activity when rodent PVAT is stimulated by noradrenaline.
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Affiliation(s)
- Charlotte E Bussey
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Sarah B Withers
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK.,Environment and Life Sciences, University of Salford, Salford, UK
| | - Sophie N Saxton
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Neil Bodagh
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Robert G Aldous
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Anthony M Heagerty
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
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Shi W, Zeng Y, Zhou L, Xiao Y, Cummins TR, Baker LA. Membrane patches as ion channel probes for scanning ion conductance microscopy. Faraday Discuss 2018; 193:81-97. [PMID: 27711908 DOI: 10.1039/c6fd00133e] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
We describe dual-barrel ion channel probes (ICPs), which consist of an open barrel and a barrel with a membrane patch directly excised from a donor cell. When incorporated with scanning ion conductance microscopy (SICM), the open barrel (SICM barrel) serves to measure the distance-dependent ion current for non-invasive imaging and positioning of the probe in the same fashion of traditional SICM. The second barrel with the membrane patch supports ion channels of interest and was used to investigate ion channel activities. To demonstrate robust probe control with the dual-barrel ICP-SICM probe and verify that the two barrels are independently addressable, current-distance characteristics (approach curves) were obtained with the SICM barrel and simultaneous, current-time (I-T) traces were recorded with the ICP barrel. To study the influence that the distance between ligand-gated ion channels (i.e., large conductance Ca2+-activated K+ channels/BK channels) and the ligand source (i.e., Ca2+ source) has on channel activations, ion channel activities were recorded at two fixed probe-substrate distances (Dps) with the ICP barrel. The two fixed positions were determined from approach curves acquired with the SICM barrel. One position was defined as the "In-control" position, where the probe was in close proximity to the ligand source; the second position was defined as the "Far" position, where the probe was retracted far away from the ligand source. Our results confirm that channel activities increased dramatically with respect to both open channel probability and single channel current when the probe was near the ligand source, as opposed to when the probe was far away from the ligand source.
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Affiliation(s)
- Wenqing Shi
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana 47405, USA.
| | - Yuhan Zeng
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana 47405, USA.
| | - Lushan Zhou
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana 47405, USA.
| | - Yucheng Xiao
- Department of Pharmacology and Toxicology, Indiana University-Purdue University Indianapolis, Stark Neurosciences Research Institute, 320 W. 15th St., Indianapolis, IN 46202, USA.
| | - Theodore R Cummins
- Department of Pharmacology and Toxicology, Indiana University-Purdue University Indianapolis, Stark Neurosciences Research Institute, 320 W. 15th St., Indianapolis, IN 46202, USA.
| | - Lane A Baker
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana 47405, USA.
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