1
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Gazulla J, Berciano J. Potential Benefit of Channel Activators in Loss-of-Function Primary Potassium Channelopathies Causing Heredoataxia. CEREBELLUM (LONDON, ENGLAND) 2024; 23:833-837. [PMID: 37460907 DOI: 10.1007/s12311-023-01584-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/29/2023] [Indexed: 03/20/2024]
Abstract
Potassium channels (KCN) are transmembrane complexes that regulate the resting membrane potential and the duration of action potentials in cells. The opening of KCN brings about an efflux of K+ ions that induces cell repolarization after depolarization, returns the transmembrane potential to its resting state, and enables for continuous spiking ability. The aim of this work was to assess the role of KCN dysfunction in the pathogenesis of hereditary ataxias and the mechanisms of action of KCN opening agents (KCO). In consequence, a review of the ad hoc medical literature was performed. Among hereditary KCN diseases causing ataxia, mutated Kv3.3, Kv4.3, and Kv1.1 channels provoke spinocerebellar ataxia (SCA) type 13, SCA19/22, and episodic ataxia type 1 (EA1), respectively. The K+ efflux was found to be reduced in experimental models of these diseases, resulting in abnormally prolonged depolarization and incomplete repolarization, thereby interfering with repetitive discharges in the cells. Hence, substances able to promote normal spiking activity in the cerebellum could provide symptomatic benefit. Although drugs used in clinical practice do not activate Kv3.3 or Kv4.3 directly, available KCO probably could ameliorate ataxic symptoms in SCA13 and SCA19/22, as verified with acetazolamide in EA1, and retigabine in a mouse model of hypokalemic periodic paralysis. To summarize, ataxia could possibly be improved by non-specific KCO in SCA13 and SCA19/22. The identification of new specific KCO agents will undoubtedly constitute a promising therapeutic strategy for these diseases.
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Affiliation(s)
- José Gazulla
- Department of Neurology, Hospital Universitario Miguel Servet, Isabel la Católica, 1-3, 50009, Saragossa, Spain.
| | - José Berciano
- Department of Neurology, Hospital Universitario Marqués de Valdecilla (IDIVAL), University of Cantabria, CIBERNED, Avenida de Valdecilla S/N, 39008, Santander, Spain
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2
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Jiang L, Li J, Reilly S, Xin H, Guo N, Zhang X. Role of organellar Ca2+-activated K+ channels in disease development. Life Sci 2023; 316:121433. [PMID: 36708987 DOI: 10.1016/j.lfs.2023.121433] [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: 11/09/2022] [Revised: 01/16/2023] [Accepted: 01/19/2023] [Indexed: 01/27/2023]
Abstract
The organellar Ca2+-activated K+ channels share a similar ability to transfer the alteration of Ca2+ concentration to membrane conductance of potassium. Multiple effects of Ca2+-activated K+ channels on cell metabolism and complex signaling pathways during organ development have been explored. The organellar Ca2+-activated K+ channels are able to control the ionic equilibrium and are always associated with oxidative stress in different organelles and the whole cells. Some drugs targeting Ca2+-activated K+ channels have been tested for various diseases in clinical trials. In this review, the known roles of organellar Ca2+-activated K+ channels were described, and their effects on different diseases, particularly on diabetes, cardiovascular diseases, and neurological diseases were discussed. It was attempted to summarize the currently known operational modes with the involvement of organellar Ca2+-activated K+ channels. This review may assist scholars to more comprehensively understand organellar Ca2+-activated K+ channels and related diseases.
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Affiliation(s)
- Lan Jiang
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Jiawei Li
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Svetlana Reilly
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Hong Xin
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Nan Guo
- Department of Pharmacy, Minhang hospital, Fudan University, Shanghai, China.
| | - Xuemei Zhang
- Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China.
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3
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Ahmed M, Ganesan A, Barakat K. Leveraging structural and 2D-QSAR to investigate the role of functional group substitutions, conserved surface residues and desolvation in triggering the small molecule-induced dimerization of hPD-L1. BMC Chem 2022; 16:49. [PMID: 35761353 PMCID: PMC9238240 DOI: 10.1186/s13065-022-00842-w] [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: 10/01/2021] [Accepted: 06/21/2022] [Indexed: 12/02/2022] Open
Abstract
Small molecules are rising as a new generation of immune checkpoints’ inhibitors, with compounds targeting the human Programmed death-ligand 1 (hPD-L1) protein are pioneering this area of research. Promising examples include the recently disclosed compounds from Bristol-Myers-Squibb (BMS). These molecules bind specifically to hPD-L1 through a unique mode of action. They induce dimerization between two hPD-L1 monomers through the hPD-1 binding interface in each monomer, thereby inhibiting the PD-1/PD-L1 axis. While the recently reported crystal structures of such small molecules bound to hPD-L1 reveal valuable insights regarding their molecular interactions, there is still limited information about the dynamics driving this unusual complex formation. The current study provides an in-depth computational structural analysis to study the interactions of five small molecule compounds in complex with hPD-L1. By employing a combination of molecular dynamic simulations, binding energy calculations and computational solvent mapping techniques, our analyses quantified the dynamic roles of different hydrophilic and lipophilic residues at the surface of hPD-L1 in mediating these interactions. Furthermore, ligand-based analyses, including Free-Wilson 2D-QSAR was conducted to quantify the impact of R-group substitutions at different sites of the phenoxy-methyl biphenyl core. Our results emphasize the importance of a terminal phenyl ring that must be present in any hPD-L1 small molecule inhibitor. This phenyl moiety overlaps with a very unfavorable hydration site, which can explain the ability of such small molecules to trigger hPD-L1 dimerization.
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Affiliation(s)
- Marawan Ahmed
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Aravindhan Ganesan
- ArGan's Lab, School of Pharmacy, University of Waterloo, Kitchener, ON, Canada
| | - Khaled Barakat
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada. .,Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB, Canada.
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4
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Li Z, Cipolla MJ. Mechanisms of Flow-Mediated Dilation of Pial Collaterals and the Effect of Hypertension. Hypertension 2022; 79:457-467. [PMID: 34856815 PMCID: PMC8755599 DOI: 10.1161/hypertensionaha.121.18602] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/21/2021] [Indexed: 02/03/2023]
Abstract
Leptomeningeal anastomoses are small distal anastomotic vessels also known as pial collaterals in the brain. These vessels redirect blood flow during an occlusion and are important for stroke treatment and outcome. Pial collaterals have unique hemodynamic forces and experience significantly increased luminal flow and shear stress after the onset of ischemic stroke. However, there is limited knowledge of how pial collaterals respond to flow and shear stress, and whether this response is altered in chronic hypertension. Using an in vitro system, pial collaterals from normotensive and hypertensive rats (n=6-8/group) were isolated and luminal flow was induced with intravascular pressure maintained at 40 mm Hg. Collateral lumen diameter was measured following each flow rate in the absence or presence of pharmacological inhibitors and activators. Collaterals from male and female Wistar rats dilated similarly to increased flow (2 µL/minute: 58.4±18.7% versus 67.9±7.4%; P=0.275), and this response was prevented by inhibition of the transient receptor potential vanilloid type 4 channel, as well as inhibitors of nitric oxide and intermediate-conductance calcium-activated potassium channels, suggesting shear stress-induced activation of this pathway was involved. However, the vasodilation was significantly impaired in hypertensive rats (2 µL/minute: 17.7±7.7%), which was restored by inhibitors of reactive oxygen species and mimicked by angiotensin II. Thus, flow- and shear stress-induced vasodilation of pial collaterals appears to be an important stimulus for increasing collateral flow during large vessel occlusion. Impairment of this response during chronic hypertension may be related to poorly engaged pial collaterals during ischemic stroke in hypertensive subjects.
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Affiliation(s)
- Zhaojin Li
- Department of Neurological Sciences, University of Vermont Robert Larner College of Medicine, Burlington, VT
| | - Marilyn J. Cipolla
- Department of Neurological Sciences, University of Vermont Robert Larner College of Medicine, Burlington, VT
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont Robert Larner College of Medicine, Burlington, VT
- Department of Pharmacology, University of Vermont Robert Larner College of Medicine, Burlington, VT
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5
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Wrzosek A, Gałecka S, Żochowska M, Olszewska A, Kulawiak B. Alternative Targets for Modulators of Mitochondrial Potassium Channels. Molecules 2022; 27:299. [PMID: 35011530 PMCID: PMC8746388 DOI: 10.3390/molecules27010299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial potassium channels control potassium influx into the mitochondrial matrix and thus regulate mitochondrial membrane potential, volume, respiration, and synthesis of reactive oxygen species (ROS). It has been found that pharmacological activation of mitochondrial potassium channels during ischemia/reperfusion (I/R) injury activates cytoprotective mechanisms resulting in increased cell survival. In cancer cells, the inhibition of these channels leads to increased cell death. Therefore, mitochondrial potassium channels are intriguing targets for the development of new pharmacological strategies. In most cases, however, the substances that modulate the mitochondrial potassium channels have a few alternative targets in the cell. This may result in unexpected or unwanted effects induced by these compounds. In our review, we briefly present the various classes of mitochondrial potassium (mitoK) channels and describe the chemical compounds that modulate their activity. We also describe examples of the multidirectional activity of the activators and inhibitors of mitochondrial potassium channels.
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Affiliation(s)
- Antoni Wrzosek
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Shur Gałecka
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Monika Żochowska
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Anna Olszewska
- Department of Histology, Medical University of Gdansk, 1a Debinki, 80-211 Gdansk, Poland;
| | - Bogusz Kulawiak
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
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6
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Rayff da Silva P, do Nascimento Gonzaga TKS, Maia RE, Araújo da Silva B. Ionic Channels as Potential Targets for the Treatment of Autism Spectrum Disorder: A Review. Curr Neuropharmacol 2022; 20:1834-1849. [PMID: 34370640 PMCID: PMC9886809 DOI: 10.2174/1570159x19666210809102547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/23/2021] [Accepted: 07/24/2021] [Indexed: 11/22/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurological condition that directly affects brain functions and can culminate in delayed intellectual development, problems in verbal communication, difficulties in social interaction, and stereotyped behaviors. Its etiology reveals a genetic basis that can be strongly influenced by socio-environmental factors. Ion channels controlled by ligand voltage-activated calcium, sodium, and potassium channels may play important roles in modulating sensory and cognitive responses, and their dysfunctions may be closely associated with neurodevelopmental disorders such as ASD. This is due to ionic flow, which is of paramount importance to maintaining physiological conditions in the central nervous system and triggers action potentials, gene expression, and cell signaling. However, since ASD is a multifactorial disease, treatment is directed only to secondary symptoms. Therefore, this research aims to gather evidence concerning the principal pathophysiological mechanisms involving ion channels in order to recognize their importance as therapeutic targets for the treatment of central and secondary ASD symptoms.
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Affiliation(s)
| | | | | | - Bagnólia Araújo da Silva
- Address correspondence to this author at the Postgraduate Program in Natural Synthetic and Bioactive Products, Heath Sciences Center, Federal University of Paraíba - Campus I, 58051-085, Via Ipê Amarelo, S/N, João Pessoa, Paraíba, Brazil; Tel: ++55-83-99352-5595; E-mail:
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7
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Abstract
Potassium channels are the most diverse and ubiquitous family of ion channels found in cells. The Ca2+ and voltage gated members form a subfamily that play a variety of roles in both excitable and non-excitable cells and are further classified on the basis of their single channel conductance to form the small conductance (SK), intermediate conductance (IK) and big conductance (BK) K+ channels.In this chapter, we will focus on the mechanisms underlying the gating of BK channels, whose function is modified in different tissues by different splice variants as well as the expanding array of regulatory accessory subunits including β, γ and LINGO subunits. We will examine how BK channels are modified by these regulatory subunits and describe how the channel gating is altered by voltage and Ca2+ whilst setting this in context with the recently published structures of the BK channel. Finally, we will discuss how BK and other calcium-activated channels are modulated by novel ion channel modulators and describe some of the challenges associated with trying to develop compounds with sufficient efficacy, potency and selectivity to be of therapeutic benefit.
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8
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Diniz AFA, Ferreira RC, de Souza ILL, da Silva BA. Ionic Channels as Potential Therapeutic Targets for Erectile Dysfunction: A Review. Front Pharmacol 2020; 11:1120. [PMID: 32848741 PMCID: PMC7396897 DOI: 10.3389/fphar.2020.01120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 07/10/2020] [Indexed: 12/12/2022] Open
Abstract
Erectile dysfunction (ED) is a prevalent condition, especially in men over 40 years old, characterized by the inability to obtain and/or maintain penile erection sufficient for satisfactory sexual intercourse. Several psychological and/or organic factors are involved in the etiopathogenesis of ED. In this context, we gathered evidence of the involvement of Large-conductance, Ca2+-activated K+ channels (BKCa), Small-conductance, Ca2+-activated K+ channels (SKCa), KCNQ-encoded voltage-dependent K+ channels (KV7), Transient Receptor Potential channels (TRP), and Calcium-activated Chloride channels (CaCC) dysfunctions on ED. In addition, the use of modulating agents of these channels are involved in relaxation of the cavernous smooth muscle cell and, consequent penile erection, suggesting that these channels are promising therapeutic targets for the treatment of erectile dysfunction.
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Affiliation(s)
- Anderson Fellyp Avelino Diniz
- Programa de Pós-Graduação em Produtos Naturais e Sintéticos Bioativos, Universidade Federal da Paraíba, João Pessoa, Brazil
| | - Rafael Carlos Ferreira
- Programa de Pós-Graduação em Produtos Naturais e Sintéticos Bioativos, Universidade Federal da Paraíba, João Pessoa, Brazil
| | - Iara Leão Luna de Souza
- Departamento de Ciências Biológicas e da Saúde, Universidade Estadual de Roraima, Boa Vista, Brazil
| | - Bagnólia Araújo da Silva
- Programa de Pós-Graduação em Produtos Naturais e Sintéticos Bioativos, Universidade Federal da Paraíba, João Pessoa, Brazil
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9
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Signaling pathways targeting mitochondrial potassium channels. Int J Biochem Cell Biol 2020; 125:105792. [PMID: 32574707 DOI: 10.1016/j.biocel.2020.105792] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/08/2020] [Accepted: 06/11/2020] [Indexed: 12/11/2022]
Abstract
In this review, we describe key signaling pathways regulating potassium channels present in the inner mitochondrial membrane. The signaling cascades covered here include phosphorylation, redox reactions, modulation by calcium ions and nucleotides. The following types of potassium channels have been identified in the inner mitochondrial membrane of various tissues: ATP-sensitive, Ca2+-activated, voltage-gated and two-pore domain potassium channels. The direct roles of these channels involve regulation of mitochondrial respiration, membrane potential and synthesis of reactive oxygen species (ROS). Changes in channel activity lead to diverse pro-life and pro-death responses in different cell types. Hence, characterizing the signaling pathways regulating mitochondrial potassium channels will facilitate understanding the physiological role of these proteins. Additionally, we describe in this paper certain regulatory mechanisms, which are unique to mitochondrial potassium channels.
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10
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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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11
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Morel C, Montgomery S, Han MH. Small-Conductance, Calcium-Activated Potassium Channels: A Key Circuit Determinant for Stress-Induced Amygdala Dysfunction. Biol Psychiatry 2019; 85:784-786. [PMID: 31046935 PMCID: PMC7595424 DOI: 10.1016/j.biopsych.2019.03.971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 03/11/2019] [Indexed: 11/25/2022]
Affiliation(s)
- Carole Morel
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Center for Affective Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Sarah Montgomery
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Center for Affective Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ming-Hu Han
- Department of Pharmacological Sciences, Nash Family Department of Neuroscience, Friedman Brain Institute, and the Center for Affective Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York.
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12
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Chimote AA, Balajthy A, Arnold MJ, Newton HS, Hajdu P, Qualtieri J, Wise-Draper T, Conforti L. A defect in KCa3.1 channel activity limits the ability of CD8 + T cells from cancer patients to infiltrate an adenosine-rich microenvironment. Sci Signal 2018; 11:11/527/eaaq1616. [PMID: 29692361 DOI: 10.1126/scisignal.aaq1616] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The limited ability of cytotoxic T cells to infiltrate solid tumors hampers immune surveillance and the efficacy of immunotherapies in cancer. Adenosine accumulates in solid tumors and inhibits tumor-specific T cells. Adenosine inhibits T cell motility through the A2A receptor (A2AR) and suppression of KCa3.1 channels. We conducted three-dimensional chemotaxis experiments to elucidate the effect of adenosine on the migration of peripheral blood CD8+ T cells from head and neck squamous cell carcinoma (HNSCC) patients. The chemotaxis of HNSCC CD8+ T cells was reduced in the presence of adenosine, and the effect was greater on HNSCC CD8+ T cells than on healthy donor (HD) CD8+ T cells. This response correlated with the inability of CD8+ T cells to infiltrate tumors. The effect of adenosine was mimicked by an A2AR agonist and prevented by an A2AR antagonist. We found no differences in A2AR expression, 3',5'-cyclic adenosine monophosphate abundance, or protein kinase A type 1 activity between HNSCC and HD CD8+ T cells. We instead detected a decrease in KCa3.1 channel activity, but not expression, in HNSCC CD8+ T cells. Activation of KCa3.1 channels by 1-EBIO restored the ability of HNSCC CD8+ T cells to chemotax in the presence of adenosine. Our data highlight the mechanism underlying the increased sensitivity of HNSCC CD8+ T cells to adenosine and the potential therapeutic benefit of KCa3.1 channel activators, which could increase infiltration of these T cells into tumors.
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Affiliation(s)
- Ameet A Chimote
- Division of Nephrology, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Andras Balajthy
- Division of Nephrology, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Michael J Arnold
- Division of Nephrology, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Hannah S Newton
- Division of Nephrology, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Peter Hajdu
- Division of Nephrology, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Julianne Qualtieri
- Department of Pathology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Trisha Wise-Draper
- Division of Hematology Oncology, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Laura Conforti
- Division of Nephrology, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA.
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13
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Hunziker M, O'Donnell AM, Puri P. Platelet-derived growth factor receptor alpha-positive cells: a new cell type in the human ureteropelvic junction. Pediatr Res 2017; 82:1080-1087. [PMID: 28902181 DOI: 10.1038/pr.2017.193] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 07/31/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND Ureteropelvic junction (UPJ) obstruction is the most common cause of congenital hydronephrosis. Normal ureteral motility requires coordinated interaction between neurons, smooth muscle cells (SMCs), and interstitial Cajal-like cells (IC-LCs). Recently, a new type of interstitial cell, platelet-derived growth factor receptor α-positive (PDGFRα+) cells, was discovered in the gastrointestinal tract and bladder.MethodsWe used immunohistochemistry to study PDGFRα protein distribution in normal human UPJ and congenital UPJ obstruction. Western blot and real-time PCR (RT-PCR) were used to study PDGFRα protein and gene expression levels. In addition, closely associated cells and small conductance Ca2+-activated K+ (SK) channels were investigated.ResultsPDGFRα+ cells were distinct from IC-LCs and SMCs and were in close proximity to nerve fibers. PDGFRα+ cells expressed SK3 channels, which are thought to mediate purinergic inhibitory neurotransmission in SMCs. The distribution of PDGFRα+ cells was similar in UPJ obstruction vs. CONTROLS However, the expression of SK3 channels in PDGFRα+ cells was decreased in UPJ obstruction vs. CONTROLS ConclusionThis study shows, for the first time, the PDGFRα+ cell expression in the human UPJ. Altered SK3 channel expression observed in PDGFRα+ cells in UPJ obstruction suggests that the impairment of SK3 activity across the UPJ may perturb upper urinary tract peristalsis in this urological condition.
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Affiliation(s)
- Manuela Hunziker
- National Children's Research Centre, Department of Pediatric Surgery, Our Lady's Children's Hospital, Dublin, Ireland
| | - Anne-Marie O'Donnell
- National Children's Research Centre, Department of Pediatric Surgery, Our Lady's Children's Hospital, Dublin, Ireland
| | - Prem Puri
- National Children's Research Centre, Department of Pediatric Surgery, Our Lady's Children's Hospital, Dublin, Ireland
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14
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Honrath B, Matschke L, Meyer T, Magerhans L, Perocchi F, Ganjam GK, Zischka H, Krasel C, Gerding A, Bakker BM, Bünemann M, Strack S, Decher N, Culmsee C, Dolga AM. SK2 channels regulate mitochondrial respiration and mitochondrial Ca 2+ uptake. Cell Death Differ 2017; 24:761-773. [PMID: 28282037 DOI: 10.1038/cdd.2017.2] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 11/29/2016] [Accepted: 12/14/2016] [Indexed: 02/06/2023] Open
Abstract
Mitochondrial calcium ([Ca2+]m) overload and changes in mitochondrial metabolism are key players in neuronal death. Small conductance calcium-activated potassium (SK) channels provide protection in different paradigms of neuronal cell death. Recently, SK channels were identified at the inner mitochondrial membrane, however, their particular role in the observed neuroprotection remains unclear. Here, we show a potential neuroprotective mechanism that involves attenuation of [Ca2+]m uptake upon SK channel activation as detected by time lapse mitochondrial Ca2+ measurements with the Ca2+-binding mitochondria-targeted aequorin and FRET-based [Ca2+]m probes. High-resolution respirometry revealed a reduction in mitochondrial respiration and complex I activity upon pharmacological activation and overexpression of mitochondrial SK2 channels resulting in reduced mitochondrial ROS formation. Overexpression of mitochondria-targeted SK2 channels enhanced mitochondrial resilience against neuronal death, and this effect was inhibited by overexpression of a mitochondria-targeted dominant-negative SK2 channel. These findings suggest that SK channels provide neuroprotection by reducing [Ca2+]m uptake and mitochondrial respiration in conditions, where sustained mitochondrial damage determines progressive neuronal death.
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Affiliation(s)
- Birgit Honrath
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany.,Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Behavioural and Cognitive Neurosciences (BCN), Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands
| | - Lina Matschke
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - Tammo Meyer
- Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Behavioural and Cognitive Neurosciences (BCN), Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands
| | - Lena Magerhans
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany
| | - Fabiana Perocchi
- Gene Center/Department of Biochemistry, Ludwig-Maximilians Universität München, Munich, Germany.,Institute for Obesity and Diabetes, Helmholtz Zentrum München, Neuherberg, Germany
| | - Goutham K Ganjam
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany
| | - Hans Zischka
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health GmbH, Neuherberg, Germany
| | - Cornelius Krasel
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany
| | - Albert Gerding
- Center for Liver, Digestive and Metabolic Diseases, Department of Pediatrics & Systems Biology Center for Energy Metabolism and Ageing, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Barbara M Bakker
- Center for Liver, Digestive and Metabolic Diseases, Department of Pediatrics & Systems Biology Center for Energy Metabolism and Ageing, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Moritz Bünemann
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany
| | - Stefan Strack
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - Carsten Culmsee
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany
| | - Amalia M Dolga
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany.,Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Behavioural and Cognitive Neurosciences (BCN), Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands
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15
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Zhang M, Meng XY, Zhang JF, Cui M, Logothetis DE. Molecular overlap in the regulation of SK channels by small molecules and phosphoinositides. SCIENCE ADVANCES 2015; 1:e1500008. [PMID: 26366439 PMCID: PMC4563807 DOI: 10.1126/sciadv.1500008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 05/29/2015] [Indexed: 06/05/2023]
Abstract
Phosphatidylinositol 4,5-bisphosphate (PIP2) directly interacts with the small-conductance Ca2+-activated K+ 2-a (SK2-a) channel/calmodulin complex, serving as a critical element in the regulation of channel activity. We report that changes of protein conformation in close proximity to the PIP2 binding site induced by a small-molecule SK channel modulator, NS309, can effectively enhance the interaction between the protein and PIP2 to potentiate channel activity. This novel modulation of PIP2 sensitivity by small-molecule drugs is likely not to be limited in its application to SK channels, representing an intriguing strategy to develop drugs controlling the activity of the large number of PIP2-dependent proteins.
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Affiliation(s)
- Miao Zhang
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, 1101 East Marshall Street, Richmond, VA 23298, USA
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, 9401 Jeronimo Road, Irvine, CA 92618, USA
| | - Xuan-Yu Meng
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, 1101 East Marshall Street, Richmond, VA 23298, USA
| | - Ji-fang Zhang
- Department of Molecular Physiology and Biophysics, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
- Farber Institute for Neurosciences and Graduate Program in Neuroscience, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Meng Cui
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, 1101 East Marshall Street, Richmond, VA 23298, USA
| | - Diomedes E. Logothetis
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, 1101 East Marshall Street, Richmond, VA 23298, USA
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