1
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Fahanik-Babaei J, Bagheri M, Salari S. Characterization of a novel Ca 2+-Activated potassium channel in rat brain rough endoplasmic reticulum. Arch Biochem Biophys 2024; 759:110105. [PMID: 39059600 DOI: 10.1016/j.abb.2024.110105] [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: 03/06/2024] [Revised: 07/23/2024] [Accepted: 07/24/2024] [Indexed: 07/28/2024]
Abstract
OBJECTIVES Potassium channels in the endoplasmic reticulum (ER) are crucial for maintaining calcium balance during calcium fluxes. Disruption in ER calcium balance leads to ER stress, implicated in diseases like diabetes and Alzheimer's disease (AD). However, limited data exists on ER potassium channels in excitable tissues such as the brain. To fill this gap, we aimed to evaluate potassium currents in rat brain rough endoplasmic reticulum (RER). METHODS Rats were euthanized under deep anesthesia and their brains were immediately removed. The brains were then homogenized in ice-cold sucrose buffer, followed by the extraction of RER microsomes through a series of centrifugation processes. Purity of sample was evaluated using western blotting technique. Single channel recordings were done in voltage steps from +50 to -60 mV following incorporation of rat brain RER vesicles into planar bilayers. RESULTS We observed a voltage-dependent potassium channel with an approximate conductance of 188 pS. Channel open probability was low at negative voltages, increasing at positive voltages. The channel was blocked by Charybdotoxin but not by Iberiotoxin. Additionally, TRAM-34, a specific KCa3.1 channel blocker, suppressed channel current amplitude and open probability. Western blot analysis revealed specific bands for anti-KCa3.1 antibody, approximately 50 kDa in brain homogenate and RER fraction. CONCLUSION Our study provides strong evidence for the presence of an KCa3.1 channel on the RER membrane in rat brain, exhibiting distinct electro-pharmacological profile compared to plasma membrane and other organelles.
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Affiliation(s)
- Javad Fahanik-Babaei
- Electrophysiology Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Maryam Bagheri
- Department of Physiology, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran
| | - Sajjad Salari
- Department of Physiology, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran.
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2
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Damir HA, Ali MA, Adem MA, Amir N, Ali OM, Tariq S, Adeghate E, Greenwood MP, Lin P, Alvira-Iraizoz F, Gillard B, Murphy D, Adem A. Effects of long-term dehydration and quick rehydration on the camel kidney: pathological changes and modulation of the expression of solute carrier proteins and aquaporins. BMC Vet Res 2024; 20:367. [PMID: 39148099 PMCID: PMC11328374 DOI: 10.1186/s12917-024-04215-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 07/31/2024] [Indexed: 08/17/2024] Open
Abstract
BACKGROUND Recurrent dehydration causes chronic kidney disease in humans and animal models. The dromedary camel kidney has remarkable capacity to preserve water and solute during long-term dehydration. In this study, we investigated the effects of dehydration and subsequent rehydration in the camel's kidney histology/ultrastructure and changes in aquaporin/solute carrier proteins along with gene expression. RESULTS In light microscopy, dehydration induced few degenerative and necrotic changes in cells of the cortical tubules with unapparent or little effect on medullary cells. The ultrastructural changes encountered in the cortex were infrequent during dehydration and included nuclear chromatin condensation, cytoplasmic vacuolization, mitochondrial swelling, endoplasmic reticulum/ lysosomal degeneration and sometimes cell death. Some mRNA gene expressions involved in cell stability were upregulated by dehydration. Lesions in endothelial capillaries, glomerular membranes and podocyte tertiary processes in dehydrated camels indicated disruption of glomerular filtration barrier which were mostly corrected by rehydration. The changes in proximal tubules brush borders after dehydration, were accompanied by down regulation of ATP1A1 mRNA involved in Na + /K + pump that were corrected by rehydration. The increased serum Na, osmolality and vasopressin were paralleled by modulation in expression level for corresponding SLC genes with net Na retention in cortex which were corrected by rehydration. Medullary collecting ducts and interstitial connective tissue were mostly unaffected during dehydration. CKD, a chronic nephropathy induced by recurrent dehydration in human and animal models and characterized by interstitial fibrosis and glomerular sclerosis, were not observed in the dehydrated/rehydrated camel kidneys. The initiating factors, endogenous fructose, AVP/AVPR2 and uric acid levels were not much affected. TGF-β1 protein and TGF-β1gene expression showed no changes by dehydration in cortex/medulla to mediate fibrosis. KCNN4 gene expression level was hardly detected in the dehydrated camel's kidney; to encode for Ca + + -gated KCa3.1 channel for Ca + + influx to instigate TGF-β1. Modulation of AQP 1, 2, 3, 4, 9 and SLC protein and/or mRNAs expression levels during dehydration/rehydration was reported. CONCLUSIONS Long-term dehydration induces reversible or irreversible ultrastructural changes in kidney cortex with minor effects in medulla. Modulation of AQP channels, SLC and their mRNAs expression levels during dehydration/rehydration have a role in water conservation. Cortex and medulla respond differently to dehydration/rehydration.
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Affiliation(s)
- Hassan Abu Damir
- Department of Pharmacology, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Mahmoud A Ali
- Department of Pharmacology, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Muna A Adem
- Department of Pharmacology, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Naheed Amir
- Department of Pharmacology, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Osman M Ali
- Department of Pharmacology, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Saeed Tariq
- Department of Anatomy, College of Medicine & Health Sciences, Emirates University, Al-Ain, United Arab Emirates
| | - Ernest Adeghate
- Department of Anatomy, College of Medicine & Health Sciences, Emirates University, Al-Ain, United Arab Emirates
| | - Michael P Greenwood
- Molecular Neuroendocrinology Research Group, Bristol Medical School, Translational Health Sciences, University of Bristol, Dorothy Hodgkin Building, Bristol, BS13NY, UK
| | - Panjiao Lin
- Molecular Neuroendocrinology Research Group, Bristol Medical School, Translational Health Sciences, University of Bristol, Dorothy Hodgkin Building, Bristol, BS13NY, UK
| | - Fernando Alvira-Iraizoz
- Molecular Neuroendocrinology Research Group, Bristol Medical School, Translational Health Sciences, University of Bristol, Dorothy Hodgkin Building, Bristol, BS13NY, UK
| | - Benjamin Gillard
- Molecular Neuroendocrinology Research Group, Bristol Medical School, Translational Health Sciences, University of Bristol, Dorothy Hodgkin Building, Bristol, BS13NY, UK
| | - David Murphy
- Molecular Neuroendocrinology Research Group, Bristol Medical School, Translational Health Sciences, University of Bristol, Dorothy Hodgkin Building, Bristol, BS13NY, UK.
| | - Abdu Adem
- Department of Pharmacology, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates.
- Department of Pharmacology, College of Medicine and Health Sciences, Khalifa University, PO. Box 127788, Abu Dhabi, UAE.
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3
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Tao H, Zhu P, Xia W, Chu M, Chen K, Wang Q, Gu Y, Lu X, Bai J, Geng D. The Emerging Role of the Mitochondrial Respiratory Chain in Skeletal Aging. Aging Dis 2024; 15:1784-1812. [PMID: 37815897 PMCID: PMC11272194 DOI: 10.14336/ad.2023.0924] [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: 08/03/2023] [Accepted: 09/24/2023] [Indexed: 10/12/2023] Open
Abstract
Maintenance of mitochondrial homeostasis is crucial for ensuring healthy mitochondria and normal cellular function. This process is primarily responsible for regulating processes that include mitochondrial OXPHOS, which generates ATP, as well as mitochondrial oxidative stress, apoptosis, calcium homeostasis, and mitophagy. Bone mesenchymal stem cells express factors that aid in bone formation and vascular growth. Positive regulation of hematopoietic stem cells in the bone marrow affects the differentiation of osteoclasts. Furthermore, the metabolic regulation of cells that play fundamental roles in various regions of the bone, as well as interactions within the bone microenvironment, actively participates in regulating bone integrity and aging. The maintenance of cellular homeostasis is dependent on the regulation of intracellular organelles, thus understanding the impact of mitochondrial functional changes on overall bone metabolism is crucially important. Recent studies have revealed that mitochondrial homeostasis can lead to morphological and functional abnormalities in senescent cells, particularly in the context of bone diseases. Mitochondrial dysfunction in skeletal diseases results in abnormal metabolism of bone-associated cells and a secondary dysregulated microenvironment within bone tissue. This imbalance in the oxidative system and immune disruption in the bone microenvironment ultimately leads to bone dysplasia. In this review, we examine the latest developments in mitochondrial respiratory chain regulation and its impacts on maintenance of bone health. Specifically, we explored whether enhancing mitochondrial function can reduce the occurrence of bone cell deterioration and improve bone metabolism. These findings offer prospects for developing bone remodeling biology strategies to treat age-related degenerative diseases.
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Affiliation(s)
- Huaqiang Tao
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Jiangsu, China.
| | - Pengfei Zhu
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Jiangsu, China.
| | - Wenyu Xia
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Jiangsu, China.
| | - Miao Chu
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Jiangsu, China.
| | - Kai Chen
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Jiangsu, China.
| | - Qiufei Wang
- Department of Orthopedics, Changshu Hospital Affiliated to Soochow University, First People’s Hospital of Changshu City, Jiangsu, China.
| | - Ye Gu
- Department of Orthopedics, Changshu Hospital Affiliated to Soochow University, First People’s Hospital of Changshu City, Jiangsu, China.
| | - Xiaomin Lu
- Department of Oncology, Affiliated Haian Hospital of Nantong University, Jiangsu, China.
| | - Jiaxiang Bai
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Jiangsu, China.
- Department of Orthopedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Anhui, China.
| | - Dechun Geng
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Jiangsu, China.
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Urrutia J, Arrizabalaga-Iriondo A, Sanchez-del-Rey A, Martinez-Ibargüen A, Gallego M, Casis O, Revuelta M. Therapeutic role of voltage-gated potassium channels in age-related neurodegenerative diseases. Front Cell Neurosci 2024; 18:1406709. [PMID: 38827782 PMCID: PMC11140135 DOI: 10.3389/fncel.2024.1406709] [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: 03/25/2024] [Accepted: 05/02/2024] [Indexed: 06/05/2024] Open
Abstract
Voltage-gated ion channels are essential for membrane potential maintenance, homeostasis, electrical signal production and controlling the Ca2+ flow through the membrane. Among all ion channels, the key regulators of neuronal excitability are the voltage-gated potassium channels (KV), the largest family of K+ channels. Due to the ROS high levels in the aging brain, K+ channels might be affected by oxidative agents and be key in aging and neurodegeneration processes. This review provides new insight about channelopathies in the most studied neurodegenerative disorders, such as Alzheimer Disease, Parkinson's Disease, Huntington Disease or Spinocerebellar Ataxia. The main affected KV channels in these neurodegenerative diseases are the KV1, KV2.1, KV3, KV4 and KV7. Moreover, in order to prevent or repair the development of these neurodegenerative diseases, previous KV channel modulators have been proposed as therapeutic targets.
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Affiliation(s)
- Janire Urrutia
- Department of Physiology, Faculty of Medicine and Nursery, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Ane Arrizabalaga-Iriondo
- Department of Physiology, Faculty of Medicine and Nursery, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Ana Sanchez-del-Rey
- Department of Otorhinolaryngology, Faculty of Medicine, University of the Basque Country, Bilbao, Spain
| | - Agustín Martinez-Ibargüen
- Department of Otorhinolaryngology, Faculty of Medicine, University of the Basque Country, Bilbao, Spain
| | - Mónica Gallego
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Vitoria-Gasteiz, Spain
| | - Oscar Casis
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Vitoria-Gasteiz, Spain
| | - Miren Revuelta
- Department of Physiology, Faculty of Medicine and Nursery, University of the Basque Country (UPV/EHU), Bilbao, Spain
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5
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Cozzolino M, Panyi G. Intracellular acidity impedes KCa3.1 activation by Riluzole and SKA-31. Front Pharmacol 2024; 15:1380655. [PMID: 38638868 PMCID: PMC11024243 DOI: 10.3389/fphar.2024.1380655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 03/05/2024] [Indexed: 04/20/2024] Open
Abstract
Background The unique microenvironment in tumors inhibits the normal functioning of tumor-infiltrating lymphocytes, leading to immune evasion and cancer progression. Over-activation of KCa3.1 using positive modulators has been proposed to rescue the anti-tumor response. One of the key characteristics of the tumor microenvironment is extracellular acidity. Herein, we analyzed how intra- and extracellular pH affects K+ currents through KCa3.1 and if the potency of two of its positive modulators, Riluzole and SKA-31, is pH sensitive. Methods Whole-cell patch-clamp was used to measure KCa3.1 currents either in activated human peripheral lymphocytes or in CHO cells transiently transfected with either the H192A mutant or wild-type hKCa3.1 in combination with T79D-Calmodulin, or with KCa2.2. Results We found that changes in the intra- and extracellular pH minimally influenced the KCa3.1-mediated K+ current. Extracellular pH, in the range of 6.0-8.0, does not interfere with the capacity of Riluzole and SKA-31 to robustly activate the K+ currents through KCa3.1. Contrariwise, an acidic intracellular solution causes a slow, but irreversible loss of potency of both the activators. Using different protocols of perfusion and depolarization we demonstrated that the loss of potency is strictly time and pH-dependent and that this peculiar effect can be observed with a structurally similar channel KCa2.2. While two different point mutations of both KCa3.1 (H192A) and its associated protein Calmodulin (T79D) do not limit the effect of acidity, increasing the cytosolic Ca2+ concentration to saturating levels eliminated the loss-of-potency phenotype. Conclusion Based on our data we conclude that KCa3.1 currents are not sensitive the either the intracellular or the extracellular pH in the physiological and pathophysiological range. However, intracellular acidosis in T cells residing in the tumor microenvironment could hinder the potentiating effect of KCa3.1 positive modulators administered to boost their activity. Further research is warranted both to clarify the molecular interactions between the modulators and KCa3.1 at different intracellular pH conditions and to define whether this loss of potency can be observed in cancer models as well.
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Affiliation(s)
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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6
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Olivas-Aguirre M, Cruz-Aguilar LH, Pottosin I, Dobrovinskaya O. Reduction of Ca 2+ Entry by a Specific Block of KCa3.1 Channels Optimizes Cytotoxic Activity of NK Cells against T-ALL Jurkat Cells. Cells 2023; 12:2065. [PMID: 37626875 PMCID: PMC10453324 DOI: 10.3390/cells12162065] [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: 06/09/2023] [Revised: 08/08/2023] [Accepted: 08/11/2023] [Indexed: 08/27/2023] Open
Abstract
Degranulation mediated killing mechanism by NK cells is dependent on store-operated Ca2+ entry (SOCE) and has optimum at moderate intracellular Ca2+ elevations so that partial block of SOCE optimizes the killing process. In this study, we tested the effect of the selective blocker of KCa3.1 channel NS6180 on SOCE and the killing efficiency of NK cells from healthy donors and NK-92 cells against T-ALL cell line Jurkat. Patch-clamp analysis showed that only one-quarter of resting NK cells functionally express KCa3.1 current, which increases 3-fold after activation by interleukins 15 and 2. Nevertheless, blockage of KCa3.1 significantly reduced SOCE and intracellular Ca2+ rise induced by IL-15 or target cell recognition. NS6180 (1 μM) decreased NK degranulation at zero time of coculture with Jurkat cells but already after 1 h, the degranulation reached the same level as in the control. Monitoring of target cell death by flow cytometry and confocal microscopy demonstrated that NS6180 significantly improved the killing ability of NK cells after 1 h in coculture with Jurkat cells and increased the Jurkat cell fraction with apoptotic and necrotic markers. Our data evidence a strong dependence of SOCE on KCa3.1 activity in NK cells and that KCa3.1 specific block can improve NK cytotoxicity.
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Affiliation(s)
- Miguel Olivas-Aguirre
- Laboratory of Immunobiology and Ionic Transport Regulation, University Center for Biomedical Research, University of Colima, Colima 28045, Mexico
- Division of Exact, Natural and Technological Sciences, South University Center (CUsur), University of Guadalajara, Guzmán City 49000, Mexico
| | - Laura Hadit Cruz-Aguilar
- Laboratory of Immunobiology and Ionic Transport Regulation, University Center for Biomedical Research, University of Colima, Colima 28045, Mexico
| | - Igor Pottosin
- Laboratory of Immunobiology and Ionic Transport Regulation, University Center for Biomedical Research, University of Colima, Colima 28045, Mexico
| | - Oxana Dobrovinskaya
- Laboratory of Immunobiology and Ionic Transport Regulation, University Center for Biomedical Research, University of Colima, Colima 28045, Mexico
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Wubulikasimu A, He Z, Long Y, Yuan F, Hou W, Liao Q, Chen H, Rong M. Molecular mechanism of HNTX-I activates the intermediate-conductance Ca 2+-activated K + (IK) channels. Int J Biol Macromol 2023:125197. [PMID: 37285887 DOI: 10.1016/j.ijbiomac.2023.125197] [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: 05/01/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 06/09/2023]
Abstract
The IK channel, a potassium ion channel regulated by calcium ions and voltages in a bidirectional manner, has been implicated in a range of diseases. However, there are currently few compounds available that can target the IK channel with high potency and specificity. Hainantoxin-I (HNTX-I) is the first peptide activator of IK channel discovered so far, but its activity is not ideal, and the underlying mechanism interaction between HNTX-I toxin and IK channel remains unclear. Thus, our study aimed to enhance the potency of IK channel activating peptides derived from HNTX-I and elucidate the molecular mechanism underlying the interaction between HNTX-I and the IK channel. By employing virtual alanine scanning mutagenesis, we generated 11 HNTX-I mutants using site-directed mutagenesis to pinpoint specific residues crucial for the HNTX-I and IK channel interaction. Subsequently, we identified key residues on the IK channel that are involved in the interaction with HNTX-I. Additionally, molecular docking was employed to guide the molecular engineering process and clarify the binding interface between HNTX-I and the IK channel. Our results demonstrate that HNTX-I primarily acts on the IK channel via the N-terminal amino acid, and its interaction with the IK channel is mediated by electrostatic and hydrophobic interactions, specifically the amino acid residues at positions 1, 3, 5, and 7 on HNTX-I. This study provides valuable insights into the peptide toxins that may serve as potential templates for the development of activators with enhanced potency and selectivity for the IK channel.
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Affiliation(s)
- Atikan Wubulikasimu
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Ziyan He
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Yanping Long
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Fuchu Yuan
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Wenqian Hou
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Qiong Liao
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Haiyan Chen
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, People's Republic of China.
| | - Mingqiang Rong
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, People's Republic of China.
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8
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Szanto TG, Feher A, Korpos E, Gyöngyösi A, Kállai J, Mészáros B, Ovari K, Lányi Á, Panyi G, Varga Z. 5-Chloro-2-Guanidinobenzimidazole (ClGBI) Is a Non-Selective Inhibitor of the Human H V1 Channel. Pharmaceuticals (Basel) 2023; 16:ph16050656. [PMID: 37242439 DOI: 10.3390/ph16050656] [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: 03/22/2023] [Revised: 04/13/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023] Open
Abstract
5-chloro-2-guanidinobenzimidazole (ClGBI), a small-molecule guanidine derivative, is a known effective inhibitor of the voltage-gated proton (H+) channel (HV1, Kd ≈ 26 μM) and is widely used both in ion channel research and functional biological assays. However, a comprehensive study of its ion channel selectivity determined by electrophysiological methods has not been published yet. The lack of selectivity may lead to incorrect conclusions regarding the role of hHv1 in physiological or pathophysiological responses in vitro and in vivo. We have found that ClGBI inhibits the proliferation of lymphocytes, which absolutely requires the functioning of the KV1.3 channel. We, therefore, tested ClGBI directly on hKV1.3 using a whole-cell patch clamp and found an inhibitory effect similar in magnitude to that seen on hHV1 (Kd ≈ 72 μM). We then further investigated ClGBI selectivity on the hKV1.1, hKV1.4-IR, hKV1.5, hKV10.1, hKV11.1, hKCa3.1, hNaV1.4, and hNaV1.5 channels. Our results show that, besides HV1 and KV1.3, all other off-target channels were inhibited by ClGBI, with Kd values ranging from 12 to 894 μM. Based on our comprehensive data, ClGBI has to be considered a non-selective hHV1 inhibitor; thus, experiments aiming at elucidating the significance of these channels in physiological responses have to be carefully evaluated.
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Affiliation(s)
- Tibor G Szanto
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Adam Feher
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Eva Korpos
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Adrienn Gyöngyösi
- Department of Immunology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Judit Kállai
- ELKH-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- Department of Immunology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Beáta Mészáros
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Krisztian Ovari
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Árpád Lányi
- Department of Immunology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Gyorgy Panyi
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Zoltan Varga
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
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Soret B, Hense J, Lüdtke S, Thale I, Schwab A, Düfer M. Pancreatic K Ca3.1 channels in health and disease. Biol Chem 2023; 404:339-353. [PMID: 36571487 DOI: 10.1515/hsz-2022-0232] [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: 07/15/2022] [Accepted: 11/24/2022] [Indexed: 12/27/2022]
Abstract
Ion channels play an important role for regulation of the exocrine and the endocrine pancreas. This review focuses on the Ca2+-regulated K+ channel KCa3.1, encoded by the KCNN4 gene, which is present in both parts of the pancreas. In the islets of Langerhans, KCa3.1 channels are involved in the regulation of membrane potential oscillations characterizing nutrient-stimulated islet activity. Channel upregulation is induced by gluco- or lipotoxic conditions and might contribute to micro-inflammation and impaired insulin release in type 2 diabetes mellitus as well as to diabetes-associated renal and vascular complications. In the exocrine pancreas KCa3.1 channels are expressed in acinar and ductal cells. They are thought to play a role for anion secretion during digestion but their physiological role has not been fully elucidated yet. Pancreatic carcinoma, especially pancreatic ductal adenocarcinoma (PDAC), is associated with drastic overexpression of KCa3.1. For pharmacological targeting of KCa3.1 channels, we are discussing the possible benefits KCa3.1 channel inhibitors might provide in the context of diabetes mellitus and pancreatic cancer, respectively. We are also giving a perspective for the use of a fluorescently labeled derivative of the KCa3.1 blocker senicapoc as a tool to monitor channel distribution in pancreatic tissue. In summary, modulating KCa3.1 channel activity is a useful strategy for exo-and endocrine pancreatic disease but further studies are needed to evaluate its clinical suitability.
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Affiliation(s)
- Benjamin Soret
- University of Münster, Institute of Physiology II, Robert-Koch-Straße 27b, D-48149 Münster, Germany
| | - Jurek Hense
- University of Münster, Institute of Pharmaceutical and Medicinal Chemistry, Department of Pharmacology, Corrensstraße 48, D-48149 Münster, Germany
| | - Simon Lüdtke
- University of Münster, Institute of Pharmaceutical and Medicinal Chemistry, Department of Pharmacology, Corrensstraße 48, D-48149 Münster, Germany
| | - Insa Thale
- University of Münster, Institute of Pharmaceutical and Medicinal Chemistry, Corrensstraße 48, D-48149 Münster, Germany
| | - Albrecht Schwab
- University of Münster, Institute of Physiology II, Robert-Koch-Straße 27b, D-48149 Münster, Germany
| | - Martina Düfer
- University of Münster, Institute of Pharmaceutical and Medicinal Chemistry, Department of Pharmacology, Corrensstraße 48, D-48149 Münster, Germany
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10
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Development of a Novel KCNN4-Related ceRNA Network and Prognostic Model for Renal Clear Cell Carcinoma. Anal Cell Pathol 2023. [DOI: 10.1155/2023/2533992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Background. Clear cell renal cell carcinoma (ccRCC) accounts for more than 80% of renal cell carcinomas. Yet, it has not been fully understood about the derivation and progression of the tumor, as well as the long-term benefits from multimodality therapy. Therefore, reliable and applicable molecular markers are urgently needed for the prediction of diagnosis and prognosis of ccRCC patients. Methods. Genetic and clinical information of 533 ccRCC patients from The Cancer Genome Atlas database was collected for comprehensive bioinformatic analyses. UALCAN was used to detect gene expression in paired tumor samples. Two data sets from Gene Expression Omnibus database were analyzed to identify differentially expressed genes (DEGs), and Gene Set Enrichment Analysis was applied for the functional enrichment of DEGs. Tumor Immune Single Cell Hub and Tumor IMmune Estimation Resource databases were separately used for analyses of single-immune cell and immune cell infiltration. Encyclopedia of RNA Interactomes database was explored to predict targeted microRNAs (miRNAs) and corresponding long non-coding RNAs (lncRNAs). Cox regression analysis was performed for the construction of risk signature and prognosis model. Finally, quantitative real-time polymerase chain reaction and western blot were conducted for KCNN4 expression detection in cell lines and clinical samples. Small interfering RNA was employed to knock down KCNN4, and corresponding functional experiments were conducted on ccRCC cells as well. Results. KCNN4 showed elevated expression in tumors and prominent clinical correlation in ccRCC. In total, 41 KCNN4-related genes were enriched, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed they were intimately related to immune-related signaling pathways. Spearman’s analysis revealed the significantly positive correlation of KCNN4 with immune cell infiltration. By integrating hub miRNA-let-7e-5p and four critical lncRNA, a competitive endogenous RNA network-based risk signature was constructed. The prognosis model derived from it showed considerable predictive value for survival of ccRCC patients. Finally, in vitro experiments confirmed the remarkable tumor-promoting role of KCNN4 in ccRCC cells. Conclusion. KCNN4 significantly affected the immune status of tumor microenvironment and immunotherapy elements, through which it promoted tumor progression in ccRCC, and it could be a potential biomarker for prognosis and immunotherapy effects of ccRCC patients.
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11
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Numata T, Sato-Numata K, Yoshino M. Intermediate conductance Ca 2+-activated potassium channels are activated by functional coupling with stretch-activated nonselective cation channels in cricket myocytes. FRONTIERS IN INSECT SCIENCE 2023; 2:1100671. [PMID: 38468799 PMCID: PMC10926553 DOI: 10.3389/finsc.2022.1100671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 12/20/2022] [Indexed: 03/13/2024]
Abstract
Cooperative gating of localized ion channels ranges from fine-tuning excitation-contraction coupling in muscle cells to controlling pace-making activity in the heart. Membrane deformation resulting from muscle contraction activates stretch-activated (SA) cation channels. The subsequent Ca2+ influx activates spatially localized Ca2+-sensitive K+ channels to fine-tune spontaneous muscle contraction. To characterize endogenously expressed intermediate conductance Ca2+-activated potassium (IK) channels and assess the functional relevance of the extracellular Ca2+ source leading to IK channel activity, we performed patch-clamp techniques on cricket oviduct myocytes and recorded single-channel data. In this study, we first investigated the identification of IK channels that could be distinguished from endogenously expressed large-conductance Ca2+-activated potassium (BK) channels by adding extracellular Ba2+. The single-channel conductance of the IK channel was 62 pS, and its activity increased with increasing intracellular Ca2+ concentration but was not voltage-dependent. These results indicated that IK channels are endogenously expressed in cricket oviduct myocytes. Second, the Ca2+ influx pathway that activates the IK channel was investigated. The absence of extracellular Ca2+ or the presence of Gd3+ abolished the activity of IK channels. Finally, we investigated the proximity between SA and IK channels. The removal of extracellular Ca2+, administration of Ca2+ to the microscopic region in a pipette, and application of membrane stretching stimulation increased SA channel activity, followed by IK channel activity. Membrane stretch-induced SA and IK channel activity were positively correlated. However, the emergence of IK channel activity and its increase in response to membrane mechanical stretch was not observed without Ca2+ in the pipette. These results strongly suggest that IK channels are endogenously expressed in cricket oviduct myocytes and that IK channel activity is regulated by neighboring SA channel activity. In conclusion, functional coupling between SA and IK channels may underlie the molecular basis of spontaneous rhythmic contractions.
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Affiliation(s)
- Tomohiro Numata
- Department of Integrative Physiology, Graduate School of Medicine, Akita University, Akita, Japan
- Department of Biology, Tokyo Gakugei University, Tokyo, Japan
| | - Kaori Sato-Numata
- Department of Integrative Physiology, Graduate School of Medicine, Akita University, Akita, Japan
- Department of Biology, Tokyo Gakugei University, Tokyo, Japan
| | - Masami Yoshino
- Department of Biology, Tokyo Gakugei University, Tokyo, Japan
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12
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Thale I, Maskri S, Grey L, Todesca LM, Budde T, Maisuls I, Strassert CA, Koch O, Schwab A, Wünsch B. Imaging of K Ca 3.1 Channels in Tumor Cells with PET and Small-Molecule Fluorescent Probes. ChemMedChem 2023; 18:e202200551. [PMID: 36315933 PMCID: PMC10098740 DOI: 10.1002/cmdc.202200551] [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: 10/10/2022] [Revised: 10/31/2022] [Indexed: 01/20/2023]
Abstract
The Ca2+ activated K+ channel KCa 3.1 is overexpressed in several human tumor cell lines, e. g. clear cell renal carcinoma, prostate cancer, non-small cell lung cancer. Highly aggressive cancer cells use this ion channel for key processes of the metastatic cascade such as migration, extravasation and invasion. Therefore, small molecules, which are able to image this KCa 3.1 channel in vitro and in vivo represent valuable diagnostic and prognostic tool compounds. The [18 F]fluoroethyltriazolyl substituted senicapoc was used as positron emission tomography (PET) tracer and showed promising properties for imaging of KCa 3.1 channels in lung adenocarcinoma cells in mice. The novel senicapoc BODIPY conjugates with two F-atoms (9 a) and with a F-atom and a methoxy moiety (9 b) at the B-atom led to the characteristic punctate staining pattern resulting from labeling of single KCa 3.1 channels in A549-3R cells. This punctate pattern was completely removed by preincubation with an excess of senicapoc confirming the high specificity of KCa 3.1 labeling. Due to the methoxy moiety at the B-atom and the additional oxyethylene unit in the spacer, 9 b exhibits higher polarity, which improves solubility and handling without reduction of fluorescence quantum yield. Docking studies using a cryo-electron microscopy (EM) structure of the KCa 3.1 channel confirmed the interaction of 9 a and 9 b with a binding pocket in the channel pore.
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Affiliation(s)
- Insa Thale
- Westfälische Wilhelms-Universität Münster, GRK 2515, Chemical biology of ion channels (Chembion), Corrensstraße 48, 48149, Münster, Germany.,Westfälische Wilhelms-Universität Münster, Institut für Pharmazeutische und Medizinische Chemie, Corrensstraße 48, 48149, Münster, Germany
| | - Sarah Maskri
- Westfälische Wilhelms-Universität Münster, GRK 2515, Chemical biology of ion channels (Chembion), Corrensstraße 48, 48149, Münster, Germany.,Westfälische Wilhelms-Universität Münster, Institut für Pharmazeutische und Medizinische Chemie, Corrensstraße 48, 48149, Münster, Germany
| | - Lucie Grey
- Westfälische Wilhelms-Universität Münster, Institut für Pharmazeutische und Medizinische Chemie, Corrensstraße 48, 48149, Münster, Germany
| | - Luca Matteo Todesca
- Westfälische Wilhelms-Universität Münster, GRK 2515, Chemical biology of ion channels (Chembion), Corrensstraße 48, 48149, Münster, Germany.,Westfälische Wilhelms-Universität Münster, Universitätsklinikum Münster, Institute of Physiology II, Robert-Koch-Straße 27b, 48149, Münster, Germany
| | - Thomas Budde
- Westfälische Wilhelms-Universität Münster, GRK 2515, Chemical biology of ion channels (Chembion), Corrensstraße 48, 48149, Münster, Germany.,Westfälische Wilhelms-Universität Münster, Universitätsklinikum Münster, Institute of Physiology I, Robert-Koch-Straße 27a, 48149, Münster, Germany
| | - Ivan Maisuls
- Westfälische Wilhelms-Universität Münster, Institut für Anorganische und Analytische Chemie CiMIC, SoN, Corrensstraße 28, 48149, Münster, Germany.,Westfälische Wilhelms-Universität Münster, CeNTech, Heisenbergstraße 11, 48149, Münster, Germany
| | - Cristian A Strassert
- Westfälische Wilhelms-Universität Münster, Institut für Anorganische und Analytische Chemie CiMIC, SoN, Corrensstraße 28, 48149, Münster, Germany.,Westfälische Wilhelms-Universität Münster, CeNTech, Heisenbergstraße 11, 48149, Münster, Germany
| | - Oliver Koch
- Westfälische Wilhelms-Universität Münster, GRK 2515, Chemical biology of ion channels (Chembion), Corrensstraße 48, 48149, Münster, Germany.,Westfälische Wilhelms-Universität Münster, Institut für Pharmazeutische und Medizinische Chemie, Corrensstraße 48, 48149, Münster, Germany
| | - Albrecht Schwab
- Westfälische Wilhelms-Universität Münster, GRK 2515, Chemical biology of ion channels (Chembion), Corrensstraße 48, 48149, Münster, Germany.,Westfälische Wilhelms-Universität Münster, Universitätsklinikum Münster, Institute of Physiology II, Robert-Koch-Straße 27b, 48149, Münster, Germany
| | - Bernhard Wünsch
- Westfälische Wilhelms-Universität Münster, GRK 2515, Chemical biology of ion channels (Chembion), Corrensstraße 48, 48149, Münster, Germany.,Westfälische Wilhelms-Universität Münster, Institut für Pharmazeutische und Medizinische Chemie, Corrensstraße 48, 48149, Münster, Germany
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13
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Ca 2+-Activated K + Channels and the Regulation of the Uteroplacental Circulation. Int J Mol Sci 2023; 24:ijms24021349. [PMID: 36674858 PMCID: PMC9867535 DOI: 10.3390/ijms24021349] [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: 12/14/2022] [Revised: 01/06/2023] [Accepted: 01/08/2023] [Indexed: 01/13/2023] Open
Abstract
Adequate uteroplacental blood supply is essential for the development and growth of the placenta and fetus during pregnancy. Aberrant uteroplacental perfusion is associated with pregnancy complications such as preeclampsia, fetal growth restriction (FGR), and gestational diabetes. The regulation of uteroplacental blood flow is thus vital to the well-being of the mother and fetus. Ca2+-activated K+ (KCa) channels of small, intermediate, and large conductance participate in setting and regulating the resting membrane potential of vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) and play a critical role in controlling vascular tone and blood pressure. KCa channels are important mediators of estrogen/pregnancy-induced adaptive changes in the uteroplacental circulation. Activation of the channels hyperpolarizes uteroplacental VSMCs/ECs, leading to attenuated vascular tone, blunted vasopressor responses, and increased uteroplacental blood flow. However, the regulation of uteroplacental vascular function by KCa channels is compromised in pregnancy complications. This review intends to provide a comprehensive overview of roles of KCa channels in the regulation of the uteroplacental circulation under physiological and pathophysiological conditions.
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14
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Tiffner A, Hopl V, Derler I. CRAC and SK Channels: Their Molecular Mechanisms Associated with Cancer Cell Development. Cancers (Basel) 2022; 15:cancers15010101. [PMID: 36612099 PMCID: PMC9817886 DOI: 10.3390/cancers15010101] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 12/28/2022] Open
Abstract
Cancer represents a major health burden worldwide. Several molecular targets have been discovered alongside treatments with positive clinical outcomes. However, the reoccurrence of cancer due to therapy resistance remains the primary cause of mortality. Endeavors in pinpointing new markers as molecular targets in cancer therapy are highly desired. The significance of the co-regulation of Ca2+-permeating and Ca2+-regulated ion channels in cancer cell development, proliferation, and migration make them promising molecular targets in cancer therapy. In particular, the co-regulation of the Orai1 and SK3 channels has been well-studied in breast and colon cancer cells, where it finally leads to an invasion-metastasis cascade. Nevertheless, many questions remain unanswered, such as which key molecular components determine and regulate their interplay. To provide a solid foundation for a better understanding of this ion channel co-regulation in cancer, we first shed light on the physiological role of Ca2+ and how this ion is linked to carcinogenesis. Then, we highlight the structure/function relationship of Orai1 and SK3, both individually and in concert, their role in the development of different types of cancer, and aspects that are not yet known in this context.
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15
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Liu J, Li X, Xu N, Han H, Li X. Role of ion channels in the mechanism of proteinuria (Review). Exp Ther Med 2022; 25:27. [PMID: 36561615 PMCID: PMC9748662 DOI: 10.3892/etm.2022.11726] [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: 07/01/2022] [Accepted: 10/10/2022] [Indexed: 11/25/2022] Open
Abstract
Proteinuria is a common clinical manifestation of kidney diseases, such as glomerulonephritis, nephrotic syndrome, immunoglobulin A nephropathy and diabetic nephropathy. Therefore, proteinuria is considered to be a risk factor for renal dysfunction. Furthermore, proteinuria is also significantly associated with the progression of kidney diseases and increased mortality. Its occurrence is closely associated with damage to the structure of the glomerular filtration membrane. An impaired glomerular filtration membrane can affect the selective filtration function of the kidneys; therefore, several macromolecular substances, such as proteins, may pass through the filtration membrane and promote the manifestation of proteinuria. It has been reported that ion channels play a significant role in the mechanisms underlying proteinuria. Ion channel mutations or other dysfunctions have been implicated in several diseases, therefore ion channels could be used as major therapeutic targets. The mechanisms underlying the action of ion channels and ion transporters in proteinuria have been overlooked in the literature, despite their importance in identifying novel targets for treating proteinuria and delaying the progression of kidney diseases. The current review article focused on the four key ion channel groups, namely Na+, Ca2+, Cl- and K+ ion channels and the associated ion transporters.
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Affiliation(s)
- Jie Liu
- Department of Nephrology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261000, P.R. China
| | - Xuewei Li
- Department of Rheumatology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261000, P.R. China
| | - Ning Xu
- Department of Nephrology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261000, P.R. China
| | - Huirong Han
- Department of Anesthesiology, Weifang Medical University, Weifang, Shandong 261000, P.R. China
| | - Xiangling Li
- Department of Nephrology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261000, P.R. China,Correspondence to: Professor Xiangling Li, Department of Nephrology, Affiliated Hospital of Weifang Medical University, 2428 Yu He Road, Weifang, Shandong 261000, P.R. China
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16
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Lin Y, Zhao YJ, Zhang HL, Hao WJ, Zhu RD, Wang Y, Hu W, Zhou RP. Regulatory role of KCa3.1 in immune cell function and its emerging association with rheumatoid arthritis. Front Immunol 2022; 13:997621. [PMID: 36275686 PMCID: PMC9580404 DOI: 10.3389/fimmu.2022.997621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/16/2022] [Indexed: 11/25/2022] Open
Abstract
Rheumatoid arthritis (RA) is a common autoimmune disease characterized by chronic inflammation. Immune dysfunction is an essential mechanism in the pathogenesis of RA and directly linked to synovial inflammation and cartilage/bone destruction. Intermediate conductance Ca2+-activated K+ channel (KCa3.1) is considered a significant regulator of proliferation, differentiation, and migration of immune cells by mediating Ca2+ signal transduction. Earlier studies have demonstrated abnormal activation of KCa3.1 in the peripheral blood and articular synovium of RA patients. Moreover, knockout of KCa3.1 reduced the severity of synovial inflammation and cartilage damage to a significant extent in a mouse collagen antibody-induced arthritis (CAIA) model. Accumulating evidence implicates KCa3.1 as a potential therapeutic target for RA. Here, we provide an overview of the KCa3.1 channel and its pharmacological properties, discuss the significance of KCa3.1 in immune cells and feasibility as a drug target for modulating the immune balance, and highlight its emerging role in pathological progression of RA.
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Affiliation(s)
- Yi Lin
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China
| | - Ying-Jie Zhao
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China
| | - Hai-Lin Zhang
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China
| | - Wen-Juan Hao
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China
| | - Ren-Di Zhu
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China
| | - Yan Wang
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China
| | - Wei Hu
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China
- The Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Anhui Medical University, Hefei, China
- *Correspondence: Wei Hu, ; Ren-Peng Zhou,
| | - Ren-Peng Zhou
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China
- The Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Anhui Medical University, Hefei, China
- *Correspondence: Wei Hu, ; Ren-Peng Zhou,
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17
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Allosteric inhibitors targeting the calmodulin-PIP2 interface of SK4 K + channels for atrial fibrillation treatment. Proc Natl Acad Sci U S A 2022; 119:e2202926119. [PMID: 35969786 PMCID: PMC9407317 DOI: 10.1073/pnas.2202926119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Ca2+-activated SK4 K+ channel is gated by Ca2+-calmodulin (CaM) and is expressed in immune cells, brain, and heart. A cryoelectron microscopy (cryo-EM) structure of the human SK4 K+ channel recently revealed four CaM molecules per channel tetramer, where the apo CaM C-lobe and the holo CaM N-lobe interact with the proximal carboxyl terminus and the linker S4-S5, respectively, to gate the channel. Here, we show that phosphatidylinositol 4-5 bisphosphate (PIP2) potently activates SK4 channels by docking to the boundary of the CaM-binding domain. An allosteric blocker, BA6b9, was designed to act to the CaM-PIP2-binding domain, a previously untargeted region of SK4 channels, at the interface of the proximal carboxyl terminus and the linker S4-S5. Site-directed mutagenesis, molecular docking, and patch-clamp electrophysiology indicate that BA6b9 inhibits SK4 channels by interacting with two specific residues, Arg191 and His192 in the linker S4-S5, not conserved in SK1-SK3 subunits, thereby conferring selectivity and preventing the Ca2+-CaM N-lobe from properly interacting with the channel linker region. Immunohistochemistry of the SK4 channel protein in rat hearts showed a widespread expression in the sarcolemma of atrial myocytes, with a sarcomeric striated Z-band pattern, and a weaker occurrence in the ventricle but a marked incidence at the intercalated discs. BA6b9 significantly prolonged atrial and atrioventricular effective refractory periods in rat isolated hearts and reduced atrial fibrillation induction ex vivo. Our work suggests that inhibition of SK4 K+ channels by targeting drugs to the CaM-PIP2-binding domain provides a promising anti-arrhythmic therapy.
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18
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King DR, Sedovy MW, Eaton X, Dunaway LS, Good ME, Isakson BE, Johnstone SR. Cell-To-Cell Communication in the Resistance Vasculature. Compr Physiol 2022; 12:3833-3867. [PMID: 35959755 DOI: 10.1002/cphy.c210040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The arterial vasculature can be divided into large conduit arteries, intermediate contractile arteries, resistance arteries, arterioles, and capillaries. Resistance arteries and arterioles primarily function to control systemic blood pressure. The resistance arteries are composed of a layer of endothelial cells oriented parallel to the direction of blood flow, which are separated by a matrix layer termed the internal elastic lamina from several layers of smooth muscle cells oriented perpendicular to the direction of blood flow. Cells within the vessel walls communicate in a homocellular and heterocellular fashion to govern luminal diameter, arterial resistance, and blood pressure. At rest, potassium currents govern the basal state of endothelial and smooth muscle cells. Multiple stimuli can elicit rises in intracellular calcium levels in either endothelial cells or smooth muscle cells, sourced from intracellular stores such as the endoplasmic reticulum or the extracellular space. In general, activation of endothelial cells results in the production of a vasodilatory signal, usually in the form of nitric oxide or endothelial-derived hyperpolarization. Conversely, activation of smooth muscle cells results in a vasoconstriction response through smooth muscle cell contraction. © 2022 American Physiological Society. Compr Physiol 12: 1-35, 2022.
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Affiliation(s)
- D Ryan King
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA
| | - Meghan W Sedovy
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA.,Translational Biology, Medicine, and Health Graduate Program, Virginia Tech, Blacksburg, Virginia, USA
| | - Xinyan Eaton
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA
| | - Luke S Dunaway
- Robert M. Berne Cardiovascular Research Centre, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Miranda E Good
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Centre, University of Virginia School of Medicine, Charlottesville, Virginia, USA.,Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Scott R Johnstone
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
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19
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Ma Y, Fu Y, Wang Y, Yang M, Yao Y, He S, Liu D, Cao Z, Wang X, Tang Y, Zhao Q, Huang C. Blocking Intermediate-Conductance Calcium-Activated Potassium Channels in the Macrophages Around Ganglionated Plexi Suppresses Atrial Fibrillation Vulnerability in Canines With Rapid Atrial Pacing. Front Physiol 2022; 13:837412. [PMID: 35431996 PMCID: PMC9010666 DOI: 10.3389/fphys.2022.837412] [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: 12/16/2021] [Accepted: 03/21/2022] [Indexed: 11/13/2022] Open
Abstract
Previous studies have indicated that ganglionated plexi (GP) function influences atrial fibrillation (AF) vulnerability, and intermediate-conductance calcium-activated potassium channels (SK4) have a close relationship with cardiomyocyte automaticity and the induction of AF. However, the effects of the SK4 inhibitor on GP function and AF vulnerability are unknown. Eighteen beagles were randomly divided into a control group (n = 6), rapid atrial pacing (RAP) group (n = 6), and triarylmethane-34 (TRAM-34, an SK4 inhibitor) group (n = 6). TRAM-34 (0.3 ml, 15 mmol/L) and saline were locally injected into GPs in the TRAM-34 group dogs and dogs from the other groups, respectively. After that, dogs in the RAP and TRAM-34 groups were subjected to RAP, and the neural activity of anterior right GP (ARGP) and atrial electrophysiology were measured. The levels of inflammatory cytokines and function of macrophages in the ARGP were measured in the three groups. At 10 min after TRAM-34 injection, ARGP activity and atrial electrophysiology did not significantly change. The atrial pacing shortened effective refractory period (ERP) values at all sites and increased the AF vulnerability and ARGP neural activity, while TRAM-34 reversed these changes. The levels of CD68 + cells, induced nitric oxide synthase (iNOS), interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α in the ARGP tissues were higher in the RAP group and TRAM-34 group than they were in the control group. Furthermore, the levels of the CD68 + cells, iNOS, and inflammatory cytokines in the ARGP tissues were higher in the pacing group than those in the TRAM-34 group. Based on these results, administration of TRAM-34 into the atrial GP can suppress GP activity and AF vulnerability during atrial pacing. The effects of TRAM-34 might be related to macrophage polarization and the inflammatory response of GP.
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Affiliation(s)
- Yazhe Ma
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute of Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Yuntao Fu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute of Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Youcheng Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute of Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Mei Yang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute of Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Yajun Yao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute of Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Shanqing He
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute of Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Dishiwen Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute of Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Zhen Cao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute of Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Xi Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute of Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Yanhong Tang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute of Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Qingyan Zhao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute of Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
- *Correspondence: Qingyan Zhao, ; Congxin Huang,
| | - Congxin Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovascular Research Institute of Wuhan University, Wuhan, China
- Hubei Key Laboratory of Cardiology, Wuhan, China
- *Correspondence: Qingyan Zhao, ; Congxin Huang,
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20
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Wang Y, Yao Y, Ma Y, He S, Yang M, Cao Z, Liudi S, Fu Y, Chen H, Wang X, Huang C, Zhao Q. Blockade of SK4 channels suppresses atrial fibrillation by attenuating atrial fibrosis in canines with prolonged atrial pacing. Int J Med Sci 2022; 19:1995-2007. [PMID: 36483596 PMCID: PMC9724246 DOI: 10.7150/ijms.69626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 10/28/2022] [Indexed: 11/24/2022] Open
Abstract
Background: We previously found that intermediate conductance Ca2+-activated K+ channel (SK4) might be an important target in atrial fibrillation (AF). Objective: To investigate the role of SK4 in AF maintenance. Methods: Twenty beagles were randomly assigned to the sham group (n=6), pacing group (n=7), and pacing+TRAM-34 group (n=7). Rapid atrial pacing continued for 7 days in the pacing and TRAM-34 groups. During the pacing, the TRAM-34 group received TRAM-34 intravenous injection (10 mg/Kg) 3 times per day. Atrial fibroblasts isolated from canines were treated with angiotensin II or adenovirus carrying the SK4 gene (Ad-SK4) to overexpress SK4 channels. Results: TRAM-34 treatment significantly suppressed the increased intra-atrial conducting time (CT) and AF duration in canines after rapid atrial pacing (P<0.05). Compared with the sham group, the expression of SK4 in atria was higher in the pacing group, which was associated with an increased number of myofibroblasts and levels of extracellular matrix in atrium (all P<0.05), and this effect was reversed by TRAM-34 treatment (all P<0.05). In atrial fibroblasts, the increased expression of SK4 induced by angiotensin II stimulation or Ad-SK4 transfection contributed to higher levels of P38, ERK1/2 and their downstream factors c-Jun and c-Fos, leading to the increased expression of α-SMA (all P<0.05), and all these increases were markedly reduced by TRAM-34 treatment. Conclusion: SK4 blockade suppressed AF by attenuating cardiac fibroblast activity and atrial fibrosis, which was realized through not only a decrease in fibrogenic factors but also inhibition of fibrotic signaling pathways.
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Affiliation(s)
- Youcheng Wang
- Xiaogan Hospital Affiliated to Wuhan University of Science and Technology, Xiaogan, China.,Department of Cardiology, Renmin Hospital of Wuhan University Wuhan City, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Yajun Yao
- Department of Cardiology, Renmin Hospital of Wuhan University Wuhan City, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Yazhe Ma
- Department of Cardiology, Renmin Hospital of Wuhan University Wuhan City, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Shanqing He
- Department of Cardiology, Renmin Hospital of Wuhan University Wuhan City, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Mei Yang
- Department of Cardiology, Renmin Hospital of Wuhan University Wuhan City, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Zhen Cao
- Department of Cardiology, Renmin Hospital of Wuhan University Wuhan City, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Shiwen Liudi
- Department of Cardiology, Renmin Hospital of Wuhan University Wuhan City, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Yuntao Fu
- Department of Cardiology, Renmin Hospital of Wuhan University Wuhan City, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Huiyu Chen
- Department of Cardiology, Renmin Hospital of Wuhan University Wuhan City, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Xi Wang
- Department of Cardiology, Renmin Hospital of Wuhan University Wuhan City, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Congxin Huang
- Department of Cardiology, Renmin Hospital of Wuhan University Wuhan City, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Qingyan Zhao
- Department of Cardiology, Renmin Hospital of Wuhan University Wuhan City, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
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21
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Jackson WF. Calcium-Dependent Ion Channels and the Regulation of Arteriolar Myogenic Tone. Front Physiol 2021; 12:770450. [PMID: 34819877 PMCID: PMC8607693 DOI: 10.3389/fphys.2021.770450] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 10/11/2021] [Indexed: 11/25/2022] Open
Abstract
Arterioles in the peripheral microcirculation regulate blood flow to and within tissues and organs, control capillary blood pressure and microvascular fluid exchange, govern peripheral vascular resistance, and contribute to the regulation of blood pressure. These important microvessels display pressure-dependent myogenic tone, the steady state level of contractile activity of vascular smooth muscle cells (VSMCs) that sets resting arteriolar internal diameter such that arterioles can both dilate and constrict to meet the blood flow and pressure needs of the tissues and organs that they perfuse. This perspective will focus on the Ca2+-dependent ion channels in the plasma and endoplasmic reticulum membranes of arteriolar VSMCs and endothelial cells (ECs) that regulate arteriolar tone. In VSMCs, Ca2+-dependent negative feedback regulation of myogenic tone is mediated by Ca2+-activated K+ (BKCa) channels and also Ca2+-dependent inactivation of voltage-gated Ca2+ channels (VGCC). Transient receptor potential subfamily M, member 4 channels (TRPM4); Ca2+-activated Cl− channels (CaCCs; TMEM16A/ANO1), Ca2+-dependent inhibition of voltage-gated K+ (KV) and ATP-sensitive K+ (KATP) channels; and Ca2+-induced-Ca2+ release through inositol 1,4,5-trisphosphate receptors (IP3Rs) participate in Ca2+-dependent positive-feedback regulation of myogenic tone. Calcium release from VSMC ryanodine receptors (RyRs) provide negative-feedback through Ca2+-spark-mediated control of BKCa channel activity, or positive-feedback regulation in cooperation with IP3Rs or CaCCs. In some arterioles, VSMC RyRs are silent. In ECs, transient receptor potential vanilloid subfamily, member 4 (TRPV4) channels produce Ca2+ sparklets that activate IP3Rs and intermediate and small conductance Ca2+ activated K+ (IKCa and sKCa) channels causing membrane hyperpolarization that is conducted to overlying VSMCs producing endothelium-dependent hyperpolarization and vasodilation. Endothelial IP3Rs produce Ca2+ pulsars, Ca2+ wavelets, Ca2+ waves and increased global Ca2+ levels activating EC sKCa and IKCa channels and causing Ca2+-dependent production of endothelial vasodilator autacoids such as NO, prostaglandin I2 and epoxides of arachidonic acid that mediate negative-feedback regulation of myogenic tone. Thus, Ca2+-dependent ion channels importantly contribute to many aspects of the regulation of myogenic tone in arterioles in the microcirculation.
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Affiliation(s)
- William F Jackson
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, United States
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22
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Gawali VS, Chimote AA, Newton HS, Feria-Garzón MG, Chirra M, Janssen EM, Wise-Draper TM, Conforti L. Immune Checkpoint Inhibitors Regulate K + Channel Activity in Cytotoxic T Lymphocytes of Head and Neck Cancer Patients. Front Pharmacol 2021; 12:742862. [PMID: 34512366 PMCID: PMC8429813 DOI: 10.3389/fphar.2021.742862] [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: 07/16/2021] [Accepted: 08/16/2021] [Indexed: 12/27/2022] Open
Abstract
Programmed death receptor-1 (PD-1) and its ligand (PD-L1) interaction negatively regulates T cell function in head and neck squamous cell carcinoma (HNSCC). Overexpression of PD-1 reduces intracellular Ca2+ fluxes, and thereby T cell effector functions. In HNSCC patients, PD-1 blockade increases KCa3.1 and Kv1.3 activity along with Ca2+ signaling and mobility in CD8+ peripheral blood T cells (PBTs). The mechanism by which PD-L1/PD-1 interaction regulates ion channel function is not known. We investigated the effects of blocking PD-1 and PD-L1 on ion channel functions and intracellular Ca2+ signaling in CD8+ PBTs of HNSCC patients and healthy donors (HDs) using single-cell electrophysiology and live microscopy. Anti-PD-1 and anti-PD-L1 antibodies increase KCa3.1 and Kv1.3 function in CD8+ PBTs of HNSCC patients. Anti-PD-1 treatment increases Ca2+ fluxes in a subset of HSNCC patients. In CD8+ PBTs of HDs, exposure to PD-L1 reduces KCa3.1 activity and Ca2+ signaling, which were restored by anti-PD-1 treatment. The PD-L1-induced inhibition of KCa3.1 channels was rescued by the intracellular application of the PI3 kinase modulator phosphatidylinositol 3-phosphate (PI3P) in patch-clamp experiments. In HNSCC CD8+ PBTs, anti-PD-1 treatment did not affect the expression of KCa3.1, Kv1.3, Ca2+ release activated Ca2+ (CRAC) channels, and markers of cell activation (CD69) and exhaustion (LAG-3 and TIM-3). Our data show that immune checkpoint blockade improves T cell function by increasing KCa3.1 and Kv1.3 channel activity in HNSCC patients.
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Affiliation(s)
- Vaibhavkumar S Gawali
- Department of Internal Medicine, Division of Nephrology, University of Cincinnati, Cincinnati, OH, United States
| | - Ameet A Chimote
- Department of Internal Medicine, Division of Nephrology, University of Cincinnati, Cincinnati, OH, United States
| | - Hannah S Newton
- Department of Internal Medicine, Division of Nephrology, University of Cincinnati, Cincinnati, OH, United States
| | - Manuel G Feria-Garzón
- Department of Internal Medicine, Division of Nephrology, University of Cincinnati, Cincinnati, OH, United States
| | - Martina Chirra
- Department of Internal Medicine, Division of Nephrology, University of Cincinnati, Cincinnati, OH, United States
| | - Edith M Janssen
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.,Immunology, Janssen Research and Development, Spring House, PA, United States
| | - Trisha M Wise-Draper
- Department of Internal Medicine, Division of Hematology Oncology, University of Cincinnati, Cincinnati, OH, United States
| | - Laura Conforti
- Department of Internal Medicine, Division of Nephrology, University of Cincinnati, Cincinnati, OH, United States
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23
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Abstract
K+ channels enable potassium to flow across the membrane with great selectivity. There are four K+ channel families: voltage-gated K (Kv), calcium-activated (KCa), inwardly rectifying K (Kir), and two-pore domain potassium (K2P) channels. All four K+ channels are formed by subunits assembling into a classic tetrameric (4x1P = 4P for the Kv, KCa, and Kir channels) or tetramer-like (2x2P = 4P for the K2P channels) architecture. These subunits can either be the same (homomers) or different (heteromers), conferring great diversity to these channels. They share a highly conserved selectivity filter within the pore but show different gating mechanisms adapted for their function. K+ channels play essential roles in controlling neuronal excitability by shaping action potentials, influencing the resting membrane potential, and responding to diverse physicochemical stimuli, such as a voltage change (Kv), intracellular calcium oscillations (KCa), cellular mediators (Kir), or temperature (K2P).
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24
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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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25
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Pinilla E, Sánchez A, Martínez MP, Muñoz M, García‐Sacristán A, Köhler R, Prieto D, Rivera L. Endothelial K Ca 1.1 and K Ca 3.1 channels mediate rat intrarenal artery endothelium-derived hyperpolarization response. Acta Physiol (Oxf) 2021; 231:e13598. [PMID: 33314681 DOI: 10.1111/apha.13598] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/30/2022]
Abstract
AIM Endothelium-derived hyperpolarization (EDH)-mediated response plays an essential role in the control of kidney preglomerular circulation, but the identity of the K+ channels involved in this response is still controversial. We hypothesized that large- (KCa 1.1), intermediate- (KCa 3.1) and small (KCa 2.3) -conductance Ca2+ -activated K+ (KCa ) channels are expressed in the endothelium of the preglomerular circulation and participate in the EDH-mediated response. METHODS We study the functional expression of different K+ channels in non-cultured, freshly isolated native endothelial cells (ECs) of rat intrarenal arteries using immunofluorescence and the patch-clamp technique. We correlate this with vasorelaxant responses ex vivo using wire myography. RESULTS Immunofluorescence revealed the expression of KCa 1.1, KCa 3.1 and KCa 2.3 channels in ECs. Under voltage-clamp conditions, acetylcholine induced a marked increase in the outward currents in these cells, sensitive to the blockade of KCa 1.1, KCa 3.1 and KCa 2.3 channels respectively. Isometric myography experiments, under conditions of endothelial nitric oxide synthase and cyclooxygenase inhibition, showed that blockade either of KCa 1.1 or KCa 3.1 channels was able to reduce the endothelium-derived vasorelaxation of isolated interlobar arteries, while their combined blockade completely abolished it. In contrast, blockade of KCa 2.3 channels did not reduce this vasorelaxant response, despite being functionally expressed in the endothelial cells. CONCLUSION This study shows that KCa 1.1 and KCa 3.1 channels are functionally expressed at the renal vascular endothelium and play a central role in the EDH-mediated relaxation of kidney preglomerular arteries, which is important in the control of renal blood flow and glomerular filtration rate.
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Affiliation(s)
- Estéfano Pinilla
- Departament of Physiology, Faculty of Pharmacy Complutense University of Madrid Madrid Spain
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology Aarhus University Aarhus Denmark
| | - Ana Sánchez
- Departament of Physiology, Faculty of Pharmacy Complutense University of Madrid Madrid Spain
| | - María P. Martínez
- Department of Compared Anatomy and Pathological Anatomy, Faculty of Veterinary Complutense University of Madrid Madrid Spain
| | - Mercedes Muñoz
- Departament of Physiology, Faculty of Pharmacy Complutense University of Madrid Madrid Spain
| | - Albino García‐Sacristán
- Departament of Physiology, Faculty of Pharmacy Complutense University of Madrid Madrid Spain
| | - Ralf Köhler
- Aragonese Agency for Investigation and Development & IACS/IIS Translational ResearchMiguel Servet Hospital Zaragoza Spain
| | - Dolores Prieto
- Departament of Physiology, Faculty of Pharmacy Complutense University of Madrid Madrid Spain
| | - Luis Rivera
- Departament of Physiology, Faculty of Pharmacy Complutense University of Madrid Madrid Spain
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26
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Zheng F, Tao Y, Liu J, Geng Z, Wang Y, Wang Y, Fu S, Wang W, Xie C, Zhang Y, Gong F. KCa3.1 Inhibition of Macrophages Suppresses Inflammatory Response Leading to Endothelial Damage in a Cell Model of Kawasaki Disease. J Inflamm Res 2021; 14:719-735. [PMID: 33727847 PMCID: PMC7954440 DOI: 10.2147/jir.s297131] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 02/10/2021] [Indexed: 12/18/2022] Open
Abstract
Purpose Macrophages-mediated inflammation is linked with endothelial damage of Kawasaki disease (KD). KCa3.1, a calcium-activated potassium channel, modulates inflammation of macrophages. However, little is known about the role of KCa3.1 in inflammation by macrophages involved in KD. Hence, this study is aimed to explore the potential role of KCa3.1 in regulating inflammatory response by macrophages and subsequent vascular injury in an in vitro model of KD. Methods RAW264.7 cells were stimulated with Lactobacillus casei cell wall extract (LCWE) with or without TRAM-34 or PDTC or AG490. Subsequently, mouse coronary artery endothelial cells (MCAECs) were incubated with RAW264.7 cells-conditioned medium to mimic local inflammatory lesions in KD. CCKi8 assay was used to evaluate cell viability. The mRNA levels of inflammatory mediators were detected by qRT-PCR. Expressions of KCa3.1, MCAECs injury-associated molecules, proteins involved in signal pathways of nuclear factor-κB (NF-κB), signal transducers and activators of transcription (STAT) 3 and p38 were evaluated by Western blot. Results Our study showed that LCWE increased KCa3.1 protein level in RAW264.7 macrophages and KCa3.1 inhibition by TRAM-34 notably suppressed the expression of pro-inflammatory molecules in LCWE-treated macrophages via blocking the activation of NF-κB and STAT3 pathways. Besides, the inflammation and damage of MCAECs were attenuated in the TRAM-34-treated group compared with the KD model group. This vascular protective role was dependent on the down-regulation of NF-κB and STAT3 signal pathways, which was confirmed by using inhibitors of NF-κB and STAT3. Conclusion This study demonstrates that KCa3.1 blockade of macrophages suppresses inflammatory reaction leading to mouse coronary artery endothelial cell injury in a cell model of KD by hampering the activation of NF-κB and STAT3 signaling pathway. These findings imply that KCa3.1 may be a potential therapeutic target for KD.
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Affiliation(s)
- Fenglei Zheng
- Department of Cardiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, People's Republic of China
| | - Yijing Tao
- Department of Cardiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, People's Republic of China
| | - Jingjing Liu
- Department of Cardiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, People's Republic of China
| | - Zhimin Geng
- Department of Cardiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, People's Republic of China
| | - Ying Wang
- Department of Cardiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, People's Republic of China
| | - Yujia Wang
- Department of Cardiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, People's Republic of China
| | - Songling Fu
- Department of Cardiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, People's Republic of China
| | - Wei Wang
- Department of Cardiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, People's Republic of China
| | - Chunhong Xie
- Department of Cardiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, People's Republic of China
| | - Yiying Zhang
- Department of Cardiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, People's Republic of China
| | - Fangqi Gong
- Department of Cardiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, People's Republic of China
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27
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Palomba NP, Martinello K, Cocozza G, Casciato S, Mascia A, Di Gennaro G, Morace R, Esposito V, Wulff H, Limatola C, Fucile S. ATP-evoked intracellular Ca 2+ transients shape the ionic permeability of human microglia from epileptic temporal cortex. J Neuroinflammation 2021; 18:44. [PMID: 33588880 PMCID: PMC7883449 DOI: 10.1186/s12974-021-02096-0] [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: 09/15/2020] [Accepted: 02/02/2021] [Indexed: 12/18/2022] Open
Abstract
Background Intracellular Ca2+ modulates several microglial activities, such as proliferation, migration, phagocytosis, and inflammatory mediator secretion. Extracellular ATP, the levels of which significantly change during epileptic seizures, activates specific receptors leading to an increase of intracellular free Ca2+ concentration ([Ca2+]i). Here, we aimed to functionally characterize human microglia obtained from cortices of subjects with temporal lobe epilepsy, focusing on the Ca2+-mediated response triggered by purinergic signaling. Methods Fura-2 based fluorescence microscopy was used to measure [Ca2+]i in primary cultures of human microglial cells obtained from surgical specimens. The perforated patch-clamp technique, which preserves the cytoplasmic milieu, was used to measure ATP-evoked Ca2+-dependent whole-cell currents. Results In human microglia extracellular ATP evoked [Ca2+]i increases depend on Ca2+ entry from the extracellular space and on Ca2+ mobilization from intracellular compartments. Extracellular ATP also induced a transient fivefold potentiation of the total transmembrane current, which was completely abolished when [Ca2+]i increases were prevented by removing external Ca2+ and using an intracellular Ca2+ chelator. TRAM-34, a selective KCa3.1 blocker, significantly reduced the ATP-induced current potentiation but did not abolish it. The removal of external Cl− in the presence of TRAM-34 further lowered the ATP-evoked effect. A direct comparison between the ATP-evoked mean current potentiation and mean Ca2+ transient amplitude revealed a linear correlation. Treatment of microglial cells with LPS for 48 h did not prevent the ATP-induced Ca2+ mobilization but completely abolished the ATP-mediated current potentiation. The absence of the Ca2+-evoked K+ current led to a less sustained ATP-evoked Ca2+ entry, as shown by the faster Ca2+ transient kinetics observed in LPS-treated microglia. Conclusions Our study confirms a functional role for KCa3.1 channels in human microglia, linking ATP-evoked Ca2+ transients to changes in membrane conductance, with an inflammation-dependent mechanism, and suggests that during brain inflammation the KCa3.1-mediated microglial response to purinergic signaling may be reduced. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02096-0.
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Affiliation(s)
| | | | | | | | | | | | | | - Vincenzo Esposito
- IRCCS Neuromed, Pozzilli, IS, Italy.,Department of Human Neurosciences, Sapienza Rome University, Rome, Italy
| | - Heike Wulff
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Cristina Limatola
- IRCCS Neuromed, Pozzilli, IS, Italy.,Department of Physiology and Pharmacology "V. Erspamer", Sapienza Rome University, Rome, Italy
| | - Sergio Fucile
- IRCCS Neuromed, Pozzilli, IS, Italy.,Department of Physiology and Pharmacology "V. Erspamer", Sapienza Rome University, Rome, Italy
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28
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Brömmel K, Maskri S, Bulk E, Pethő Z, Rieke M, Budde T, Koch O, Schwab A, Wünsch B. Co-staining of K Ca 3.1 Channels in NSCLC Cells with a Small-Molecule Fluorescent Probe and Antibody-Based Indirect Immunofluorescence. ChemMedChem 2020; 15:2462-2469. [PMID: 33043595 PMCID: PMC7756743 DOI: 10.1002/cmdc.202000652] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/21/2020] [Indexed: 01/01/2023]
Abstract
The Ca2+ activated potassium channel 3.1 (KCa 3.1) is involved in critical steps of the metastatic cascade, such as proliferation, migration, invasion and extravasation. Therefore, a fast and efficient protocol for imaging of KCa 3.1 channels was envisaged. The novel fluorescently labeled small molecule imaging probes 1 and 2 were synthesized by connecting a dimethylpyrrole-based BODIPY dye with a derivative of the KCa 3.1 channel inhibitor senicapoc via linkers of different length. Patch-clamp experiments revealed the inhibition of KCa 3.1 channels by the probes confirming interaction with the channel. Both probes 1 and 2 were able to stain KCa 3.1 channels in non-small-cell lung cancer (NSCLC) cells following a simple, fast and efficient protocol. Pre-incubation with unlabeled senicapoc removed the punctate staining pattern showing the specificity of the new probes 1 and 2. Staining of the channel with the fluorescently labeled senicapoc derivatives 1 or 2 or with antibody-based indirect immunofluorescence yielded identical or very similar densities of stained KCa 3.1 channels. However, co-staining using both methods did not lead to the expected overlapping punctate staining pattern. This observation was explained by docking studies showing that the antibody used for indirect immunofluorescence and the probes 1 and 2 label different channel populations. Whereas the antibody binds at the closed channel conformation, the probes 1 and 2 bind within the open channel.
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Affiliation(s)
- Kathrin Brömmel
- Institute for Pharmaceutical and Medicinal ChemistryWestphalian Wilhelms-University MünsterCorrensstraße 4848149MünsterGermany
- Cells-in-Motion Interfaculty CenterWestphalian Wilhelms-University MünsterWaldeyerstraße 1584149MünsterGermany
| | - Sarah Maskri
- Institute for Pharmaceutical and Medicinal ChemistryWestphalian Wilhelms-University MünsterCorrensstraße 4848149MünsterGermany
| | - Etmar Bulk
- Institute for Physiology IIUniversity Hospital MünsterRobert-Koch-Straße 27b48149MünsterGermany
| | - Zoltan Pethő
- Institute for Physiology IIUniversity Hospital MünsterRobert-Koch-Straße 27b48149MünsterGermany
| | - Marius Rieke
- Institute for Physiology IIUniversity Hospital MünsterRobert-Koch-Straße 27b48149MünsterGermany
| | - Thomas Budde
- Institute for Physiology IUniversity Hospital MünsterRobert-Koch-Straße 27a48149MünsterGermany
- Cells-in-Motion Interfaculty CenterWestphalian Wilhelms-University MünsterWaldeyerstraße 1584149MünsterGermany
| | - Oliver Koch
- Institute for Pharmaceutical and Medicinal ChemistryWestphalian Wilhelms-University MünsterCorrensstraße 4848149MünsterGermany
| | - Albrecht Schwab
- Institute for Physiology IIUniversity Hospital MünsterRobert-Koch-Straße 27b48149MünsterGermany
- Cells-in-Motion Interfaculty CenterWestphalian Wilhelms-University MünsterWaldeyerstraße 1584149MünsterGermany
| | - Bernhard Wünsch
- Institute for Pharmaceutical and Medicinal ChemistryWestphalian Wilhelms-University MünsterCorrensstraße 4848149MünsterGermany
- Cells-in-Motion Interfaculty CenterWestphalian Wilhelms-University MünsterWaldeyerstraße 1584149MünsterGermany
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Luo L, Song S, Ezenwukwa CC, Jalali S, Sun B, Sun D. Ion channels and transporters in microglial function in physiology and brain diseases. Neurochem Int 2020; 142:104925. [PMID: 33248207 DOI: 10.1016/j.neuint.2020.104925] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 12/19/2022]
Abstract
Microglial cells interact with all components of the central nervous system (CNS) and are increasingly recognized to play essential roles during brain development, homeostasis and disease pathologies. Functions of microglia include maintaining tissue integrity, clearing cellular debris and dead neurons through the process of phagocytosis, and providing tissue repair by releasing anti-inflammatory cytokines and neurotrophic factors. Changes of microglial ionic homeostasis (Na+, Ca2+, K+, H+, Cl-) are important for microglial activation, including proliferation, migration, cytokine release and reactive oxygen species production, etc. These are mediated by ion channels and ion transporters in microglial cells. Here, we review the current knowledge about the role of major microglial ion channels and transporters, including several types of Ca2+ channels (store-operated Ca2+ entry (SOCE) channels, transient receptor potential (TRP) channels and voltage-gated Ca2+ channels (VGCCs)) and Na+ channels (voltage-gated Na+ channels (Nav) and acid-sensing ion channels (ASICs)), K+ channels (inward rectifier K+ channels (Kir), voltage-gated K+ channels (KV) and calcium-activated K+ channels (KCa)), proton channels (voltage-gated proton channel (Hv1)), and Cl- channels (volume (or swelling)-regulated Cl- channels (VRCCs) and chloride intracellular channels (CLICs)). In addition, ion transporter proteins such as Na+/Ca2+ exchanger (NCX), Na+-K+-Cl- cotransporter (NKCC1), and Na+/H+ exchanger (NHE1) are also involved in microglial function in physiology and brain diseases. We discussed microglial activation and neuroinflammation in relation to the ion channel/transporter stimulation under brain disease conditions and therapeutic aspects of targeting microglial ion channels/transporters for neurodegenerative disease, ischemic stroke, traumatic brain injury and neuropathic pain.
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Affiliation(s)
- Lanxin Luo
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Shanshan Song
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | | | - Shayan Jalali
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Baoshan Sun
- Pólo DoisPortos, Instituto National de InvestigaçãoAgrária e Veterinária, I.P., Quinta da Almoinha, DoisPortos, 2565-191, Portugal.
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Veterans Affairs Pittsburgh Health Care System, Geriatric Research, Educational and Clinical Center, Pittsburgh, PA, 15213, USA.
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30
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Chimote AA, Gawali VS, Newton HS, Wise-Draper TM, Conforti L. A Compartmentalized Reduction in Membrane-Proximal Calmodulin Reduces the Immune Surveillance Capabilities of CD8 + T Cells in Head and Neck Cancer. Front Pharmacol 2020; 11:143. [PMID: 32184726 PMCID: PMC7059094 DOI: 10.3389/fphar.2020.00143] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 02/04/2020] [Indexed: 01/28/2023] Open
Abstract
The limited ability of cytotoxic CD8+ T cells to infiltrate solid tumors and function within the tumor microenvironment presents a major roadblock to effective immunotherapy. Ion channels and Ca2+-dependent signaling events control the activity of T cells and are implicated in the failure of immune surveillance in cancer. Reduced KCa3.1 channel activity mediates the heightened inhibitory effect of adenosine on the chemotaxis of circulating T cells from head and neck squamous cell carcinoma (HNSCC) patients. Herein, we conducted experiments that elucidate the mechanisms of KCa3.1 dysfunction and impaired chemotaxis in HNSCC CD8+ T cells. The Ca2+ sensor calmodulin (CaM) controls multiple cellular functions including KCa3.1 activation. Our data showed that CaM expression is lower in HNSCC than healthy donor (HD) T cells. This reduction was due to an intrinsic decrease in the genes encoding CaM combined to the failure of HNSCC T cells to upregulate CaM upon activation. Furthermore, the reduction in CaM was confined to the plasma membrane and resulted in decreased CaM-KCa3.1 association and KCa3.1 activity (which was rescued by the delivery of CaM). IFNγ production, also Ca2+- and CaM-dependent, was instead not reduced in HNSCC T cells, which maintained intact cytoplasmic CaM and Ca2+ fluxing ability. Knockdown of CaM in HD T cells decreased KCa3.1 activity, but not IFNγ production, and reduced their chemotaxis in the presence of adenosine, thus recapitulating HNSCC T cell dysfunction. Activation of KCa3.1 with 1-EBIO restored the ability of CaM knockdown HD T cells to chemotax in the presence of adenosine. Additionally, 1-EBIO enhanced INFγ production. Our data showed a localized downregulation of membrane-proximal CaM that suppressed KCa3.1 activity in HNSCC circulating T cells and limited their ability to infiltrate adenosine-rich tumor-like microenvironments. Furthermore, they indicate that KCa3.1 activators could be used as positive CD8+ T cell modulators in cancers.
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Affiliation(s)
- Ameet A. Chimote
- Division of Nephrology, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, United States
| | - Vaibhavkumar S. Gawali
- Division of Nephrology, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, United States
| | - Hannah S. Newton
- Division of Nephrology, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, United States
| | - Trisha M. Wise-Draper
- Division of Hematology Oncology, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, United States
| | - Laura Conforti
- Division of Nephrology, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, United States
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31
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Jia X, Su H, Chen X, Huang Y, Zheng Y, Ji P, Gao C, Gong X, Huang Y, Jiang LH, Fan Y. A critical role of the K Ca 3.1 channel in mechanical stretch-induced proliferation of rat bone marrow-derived mesenchymal stem cells. J Cell Mol Med 2020; 24:3739-3744. [PMID: 32065503 PMCID: PMC7131943 DOI: 10.1111/jcmm.15014] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 01/02/2020] [Accepted: 01/06/2020] [Indexed: 12/11/2022] Open
Abstract
Mechanical stimulation is an important factor regulating mesenchymal stem cell (MSC) functions such as proliferation. The Ca2+ -activated K+ channel, KCa 3.1, is critically engaged in MSC proliferation but its role in mechanical regulation of MSC proliferation remains unknown. Here, we examined the KCa 3.1 channel expression and its role in rat bone marrow-derived MSC (BMSC) proliferation in response to mechanical stretch. Application of mechanical stretch stimulated BMSC proliferation via promoting cell cycle progression. Such mechanical stimulation up-regulated the KCa 3.1 channel expression and pharmacological or genetic inhibition of the KCa 3.1 channel strongly suppressed stretch-induced increase in cell proliferation and cell cycle progression. These results support that the KCa 3.1 channel plays an important role in transducing mechanical forces to MSC proliferation. Our finding provides new mechanistic insights into how mechanical stimuli regulate MSC proliferation and also a viable bioengineering approach to improve MSC proliferation.
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Affiliation(s)
- Xiaoling Jia
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China.,Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing, China.,School of Biomedical Science, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Hao Su
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Xinlan Chen
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yangbi Huang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yufan Zheng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Pei Ji
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Chao Gao
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Xianghui Gong
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yan Huang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Lin-Hua Jiang
- School of Biomedical Science, Faculty of Biological Sciences, University of Leeds, Leeds, UK.,Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, China
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China.,Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing, China.,Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age Disability, National Research Center for Rehabilitation Technical Aids, Beijing, China
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32
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Barrera P, Skorka C, Boktor M, Dave N, Jimenez V. A Novel Calcium-Activated Potassium Channel Controls Membrane Potential and Intracellular pH in Trypanosoma cruzi. Front Cell Infect Microbiol 2020; 9:464. [PMID: 32010643 PMCID: PMC6974456 DOI: 10.3389/fcimb.2019.00464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 12/16/2019] [Indexed: 12/13/2022] Open
Abstract
Trypanosoma cruzi develops in environments where nutrient availability, osmolarity, ionic concentrations, and pH undergo significant changes. The ability to adapt and respond to such conditions determines the survival and successful transmission of T. cruzi. Ion channels play fundamental roles in controlling physiological parameters that ensure cell homeostasis by rapidly triggering compensatory mechanisms. Combining molecular, cellular and electrophysiological approaches we have identified and characterized the expression and function of a novel calcium-activated potassium channel (TcCAKC). This channel resides in the plasma membrane of all 3 life stages of T. cruzi and shares structural features with other potassium channels. We expressed TcCAKC in Xenopus laevis oocytes and established its biophysical properties by two-electrode voltage clamp. Oocytes expressing TcCAKC showed a significant increase in inward currents after addition of calcium ionophore ionomycin or thapsigargin. These responses were abolished by EGTA suggesting that TcCAKC activation is dependent of extracellular calcium. This activation causes an increase in current and a negative shift in reversal potential that is blocked by barium. As predicted, a single point mutation in the selectivity filter (Y313A) completely abolished the activity of the channels, confirming its potassium selective nature. We have generated knockout parasites deleting one or both alleles of TcCAKC. These parasite strains showed impaired growth, decreased production of trypomastigotes and slower intracellular replication, pointing to an important role of TcCAKC in regulating infectivity. To understand the cellular mechanisms underlying these phenotypic defects, we used fluorescent probes to evaluate intracellular membrane potential, pH, and intracellular calcium. Epimastigotes lacking the channel had significantly lower cytosolic calcium, hyperpolarization, changes in intracellular pH, and increased rate of proton extrusion. These results are in agreement with previous reports indicating that, in trypanosomatids, membrane potential and intracellular pH maintenance are linked. Our work shows TcCAKC is a novel potassium channel that contributes to homeostatic regulation of important physiological processes in T. cruzi and provides new avenues to explore the potential of ion channels as targets for drug development against protozoan parasites.
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Affiliation(s)
- Patricia Barrera
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, United States
| | - Christopher Skorka
- Departmento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Histologia y Embriologia IHEM-CONICET, Facultad de Medicina, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Michael Boktor
- Departmento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Histologia y Embriologia IHEM-CONICET, Facultad de Medicina, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Noopur Dave
- Departmento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Histologia y Embriologia IHEM-CONICET, Facultad de Medicina, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Veronica Jimenez
- Departmento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Histologia y Embriologia IHEM-CONICET, Facultad de Medicina, Universidad Nacional de Cuyo, Mendoza, Argentina
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33
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Van Hook MJ, Nawy S, Thoreson WB. Voltage- and calcium-gated ion channels of neurons in the vertebrate retina. Prog Retin Eye Res 2019; 72:100760. [PMID: 31078724 PMCID: PMC6739185 DOI: 10.1016/j.preteyeres.2019.05.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/25/2019] [Accepted: 05/01/2019] [Indexed: 02/06/2023]
Abstract
In this review, we summarize studies investigating the types and distribution of voltage- and calcium-gated ion channels in the different classes of retinal neurons: rods, cones, horizontal cells, bipolar cells, amacrine cells, interplexiform cells, and ganglion cells. We discuss differences among cell subtypes within these major cell classes, as well as differences among species, and consider how different ion channels shape the responses of different neurons. For example, even though second-order bipolar and horizontal cells do not typically generate fast sodium-dependent action potentials, many of these cells nevertheless possess fast sodium currents that can enhance their kinetic response capabilities. Ca2+ channel activity can also shape response kinetics as well as regulating synaptic release. The L-type Ca2+ channel subtype, CaV1.4, expressed in photoreceptor cells exhibits specific properties matching the particular needs of these cells such as limited inactivation which allows sustained channel activity and maintained synaptic release in darkness. The particular properties of K+ and Cl- channels in different retinal neurons shape resting membrane potentials, response kinetics and spiking behavior. A remaining challenge is to characterize the specific distributions of ion channels in the more than 100 individual cell types that have been identified in the retina and to describe how these particular ion channels sculpt neuronal responses to assist in the processing of visual information by the retina.
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Affiliation(s)
- Matthew J Van Hook
- Truhlsen Eye Institute, Department of Ophthalmology & Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA
| | - Scott Nawy
- Truhlsen Eye Institute, Department of Ophthalmology & Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA; Department Pharmacology & Experimental Neuroscience(2), University of Nebraska Medical Center, Omaha, NE, USA
| | - Wallace B Thoreson
- Truhlsen Eye Institute, Department of Ophthalmology & Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA; Department Pharmacology & Experimental Neuroscience(2), University of Nebraska Medical Center, Omaha, NE, USA.
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34
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Critical regulation of atherosclerosis by the KCa3.1 channel and the retargeting of this therapeutic target in in-stent neoatherosclerosis. J Mol Med (Berl) 2019; 97:1219-1229. [DOI: 10.1007/s00109-019-01814-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 05/07/2019] [Accepted: 06/18/2019] [Indexed: 01/09/2023]
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35
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Leanza L, Checchetto V, Biasutto L, Rossa A, Costa R, Bachmann M, Zoratti M, Szabo I. Pharmacological modulation of mitochondrial ion channels. Br J Pharmacol 2019; 176:4258-4283. [PMID: 30440086 DOI: 10.1111/bph.14544] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 10/15/2018] [Accepted: 10/22/2018] [Indexed: 12/17/2022] Open
Abstract
The field of mitochondrial ion channels has undergone a rapid development during the last three decades, due to the molecular identification of some of the channels residing in the outer and inner membranes. Relevant information about the function of these channels in physiological and pathological settings was gained thanks to genetic models for a few, mitochondria-specific channels. However, many ion channels have multiple localizations within the cell, hampering a clear-cut determination of their function by pharmacological means. The present review summarizes our current knowledge about the ins and outs of mitochondrial ion channels, with special focus on the channels that have received much attention in recent years, namely, the voltage-dependent anion channels, the permeability transition pore (also called mitochondrial megachannel), the mitochondrial calcium uniporter and some of the inner membrane-located potassium channels. In addition, possible strategies to overcome the difficulties of specifically targeting mitochondrial channels versus their counterparts active in other membranes are discussed, as well as the possibilities of modulating channel function by small peptides that compete for binding with protein interacting partners. Altogether, these promising tools along with large-scale chemical screenings set up to identify new, specific channel modulators will hopefully allow us to pinpoint the actual function of most mitochondrial ion channels in the near future and to pharmacologically affect important pathologies in which they are involved, such as neurodegeneration, ischaemic damage and cancer. LINKED ARTICLES: This article is part of a themed section on Mitochondrial Pharmacology: Featured Mechanisms and Approaches for Therapy Translation. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.22/issuetoc.
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Affiliation(s)
- Luigi Leanza
- Department of Biology, University of Padova, Padova, Italy
| | | | - Lucia Biasutto
- CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Andrea Rossa
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Roberto Costa
- Department of Biology, University of Padova, Padova, Italy
| | | | - Mario Zoratti
- CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Ildiko Szabo
- Department of Biology, University of Padova, Padova, Italy.,CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Padova, Italy
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Liu H, Kabrah A, Ahuja M, Muallem S. CRAC channels in secretory epithelial cell function and disease. Cell Calcium 2018; 78:48-55. [PMID: 30641249 DOI: 10.1016/j.ceca.2018.12.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 12/28/2018] [Accepted: 12/29/2018] [Indexed: 02/08/2023]
Abstract
The receptor-evoked Ca2+ signal in secretory epithelia mediate many cellular functions essential for cell survival and their most fundamental functions of secretory granules exocytosis and fluid and electrolyte secretion. Ca2+ influx is a key component of the receptor-evoked Ca2+ signal in secretory cell and is mediated by both TRPC and the STIM1-activated Orai1 channels that mediates the Ca2+ release-activated current (CRAC) Icrac. The core components of the receptor-evoked Ca2+ signal are assembled at the ER/PM junctions where exchange of materials between the plasma membrane and internal organelles take place, including transfer of lipids and Ca2+. The Ca2+ signal generated at the confined space of the ER/PM junctions is necessary for activation of the Ca2+-regulated proteins and ion channels that mediate exocytosis with high fidelity and tight control. In this review we discuss the general properties of Ca2+ signaling, PI(4,5)P2 and other lipids at the ER/PM junctions with regard to secretory cells function and disease caused by uncontrolled Ca2+ influx.
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Affiliation(s)
- Haiping Liu
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Ahmed Kabrah
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Malini Ahuja
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, 20892, United States.
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Role of KCa3.1 Channels in Modulating Ca 2+ Oscillations during Glioblastoma Cell Migration and Invasion. Int J Mol Sci 2018; 19:ijms19102970. [PMID: 30274242 PMCID: PMC6213908 DOI: 10.3390/ijms19102970] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 09/21/2018] [Accepted: 09/25/2018] [Indexed: 01/29/2023] Open
Abstract
Cell migration and invasion in glioblastoma (GBM), the most lethal form of primary brain tumors, are critically dependent on Ca2+ signaling. Increases of [Ca2+]i in GBM cells often result from Ca2+ release from the endoplasmic reticulum (ER), promoted by a variety of agents present in the tumor microenvironment and able to activate the phospholipase C/inositol 1,4,5-trisphosphate PLC/IP3 pathway. The Ca2+ signaling is further strengthened by the Ca2+ influx from the extracellular space through Ca2+ release-activated Ca2+ (CRAC) currents sustained by Orai/STIM channels, meant to replenish the partially depleted ER. Notably, the elevated cytosolic [Ca2+]i activates the intermediate conductance Ca2+-activated K (KCa3.1) channels highly expressed in the plasma membrane of GBM cells, and the resulting K+ efflux hyperpolarizes the cell membrane. This translates to an enhancement of Ca2+ entry through Orai/STIM channels as a result of the increased electromotive (driving) force on Ca2+ influx, ending with the establishment of a recurrent cycle reinforcing the Ca2+ signal. Ca2+ signaling in migrating GBM cells often emerges in the form of intracellular Ca2+ oscillations, instrumental to promote key processes in the migratory cycle. This has suggested that KCa3.1 channels may promote GBM cell migration by inducing or modulating the shape of Ca2+ oscillations. In accordance, we recently built a theoretical model of Ca2+ oscillations incorporating the KCa3.1 channel-dependent dynamics of the membrane potential, and found that the KCa3.1 channel activity could significantly affect the IP3 driven Ca2+ oscillations. Here we review our new theoretical model of Ca2+ oscillations in GBM, upgraded in the light of better knowledge of the KCa3.1 channel kinetics and Ca2+ sensitivity, the dynamics of the Orai/STIM channel modulation, the migration and invasion mechanisms of GBM cells, and their regulation by Ca2+ signals.
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Klumpp L, Sezgin EC, Skardelly M, Eckert F, Huber SM. KCa3.1 Channels and Glioblastoma: In Vitro Studies. Curr Neuropharmacol 2018; 16:627-635. [PMID: 28786347 PMCID: PMC5997865 DOI: 10.2174/1570159x15666170808115821] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 06/29/2017] [Accepted: 07/12/2017] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Several tumor entities including brain tumors aberrantly overexpress intermediate conductance Ca2+ activated KCa3.1 K+ channels. These channels contribute significantly to the transformed phenotype of the tumor cells. METHOD PubMed was searched in order to summarize our current knowledge on the molecular signaling upstream and downstream and the effector functions of KCa3.1 channel activity in tumor cells in general and in glioblastoma cells in particular. In addition, KCa3.1 expression and function for repair of DNA double strand breaks was determined experimentally in primary glioblastoma cultures in dependence on the abundance of proneural and mesenchymal stem cell markers. RESULTS By modulating membrane potential, cell volume, Ca2+ signals and the respiratory chain, KCa3.1 channels in both, plasma and inner mitochondrial membrane, have been demonstrated to regulate many cellular processes such as migration and tissue invasion, metastasis, cell cycle progression, oxygen consumption and metabolism, DNA damage response and cell death of cancer cells. Moreover, KCa3.1 channels have been shown to crucially contribute to resistance against radiotherapy. Futhermore, the original in vitro data on KCa3.1 channel expression in subtypes of glioblastoma stem(-like) cells propose KCa3.1 as marker for the mesenchymal subgroup of cancer stem cells and suggest that KCa3.1 contributes to the therapy resistance of mesenchymal glioblastoma stem cells. CONCLUSION The data suggest KCa3.1 channel targeting in combination with radiotherapy as promising new tool to eradicate therapy-resistant mesenchymal glioblastoma stem cells.
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Affiliation(s)
| | | | | | | | - Stephan M. Huber
- Address correspondence to this author at the Department of Radiation Oncology, University of Tübingen, Tübingen, Germany; Tel: +49-(0)7071-29-82183; E-mail:
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