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Bittner S, Höhn K, Göbel K, Kleinschnitz C, Wiendl H, Meuth SG. [Pregabalin and gabapentin in multiple sclerosis: clinical experiences and therapeutic implications]. DER NERVENARZT 2011; 82:1273-1280. [PMID: 21647743 DOI: 10.1007/s00115-011-3321-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
BACKGROUND Due to a plethora of additional symptoms patients with multiple sclerosis (MS) receive symptomatic treatment besides disease-modifying therapies. Among the substances which are commonly used are ion channel modulators (e. g. pregabalin, gabapentin, carbamazepine). The aim of this study was to investigate the use of these drugs in clinical practice in a larger patient cohort. PATIENTS Data from 533 MS patients [439 without and 94 patients with add-on therapy (treatment group)] were evaluated retrospectively. All patients received a detailed neurological examination including evaluation of EDSS scores. RESULTS Pregabalin and gabapentin are used most commonly. Abnormal sensations are the most frequent reason for therapy initiation. Patients with higher EDSS values and/or under mitoxantrone treatment most frequently receive additional therapy. CONCLUSION So far, it is not known whether the investigated agents exert a beneficial influence on the disease course of MS itself beyond a mere symptomatic treatment. Further research efforts and clinical studies are necessary to address this question.
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Affiliation(s)
- S Bittner
- Abteilung für entzündliche Erkrankungen des Nervensystems und Neuroonkologie, Klinik und Poliklinik für Neurologie, Universitätsklinikum Münster, Domagkstr. 13, 48149 Münster, Deutschland
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102
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Chi V, Pennington MW, Norton RS, Tarcha EJ, Londono LM, Sims-Fahey B, Upadhyay SK, Lakey JT, Iadonato S, Wulff H, Beeton C, Chandy KG. Development of a sea anemone toxin as an immunomodulator for therapy of autoimmune diseases. Toxicon 2011; 59:529-46. [PMID: 21867724 DOI: 10.1016/j.toxicon.2011.07.016] [Citation(s) in RCA: 163] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 06/16/2011] [Accepted: 07/20/2011] [Indexed: 01/05/2023]
Abstract
Electrophysiological and pharmacological studies coupled with molecular identification have revealed a unique network of ion channels--Kv1.3, KCa3.1, CRAC (Orai1 + Stim1), TRPM7, Cl(swell)--in lymphocytes that initiates and maintains the calcium signaling cascade required for activation. The expression pattern of these channels changes during lymphocyte activation and differentiation, allowing the functional network to adapt during an immune response. The Kv1.3 channel is of interest because it plays a critical role in subsets of T and B lymphocytes implicated in autoimmune disorders. The ShK toxin from the sea anemone Stichodactyla helianthus is a potent blocker of Kv1.3. ShK-186, a synthetic analog of ShK, is being developed as a therapeutic for autoimmune diseases, and is scheduled to begin first-in-man phase-1 trials in 2011. This review describes the journey that has led to the development of ShK-186.
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Affiliation(s)
- Victor Chi
- Department of Physiology and Biophysics, UC Irvine, Irvine, CA 92697, USA
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103
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Toldi G, Folyovich A, Simon Z, Zsiga K, Kaposi A, Mészáros G, Tulassay T, Vásárhelyi B. Lymphocyte calcium influx kinetics in multiple sclerosis treated without or with interferon β. J Neuroimmunol 2011; 237:80-6. [PMID: 21764463 DOI: 10.1016/j.jneuroim.2011.06.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Revised: 05/19/2011] [Accepted: 06/16/2011] [Indexed: 01/21/2023]
Abstract
Kv1.3 and IKCa1 potassium channels play an important role in the maintenance of calcium-influx during lymphocyte activation and present a possible target for selective immunomodulation. We investigated the calcium-influx characteristics of Th1, Th2, CD4, CD8 T-lymphocytes isolated from multiple sclerosis patients without or with interferon-beta therapy, and its modulation by Kv1.3 and IKCa1 channel inhibitors using flow cytometry. Specific immunomodulation of the CD8 subset can be reached through inhibition of Kv1.3 channels in multiple sclerosis patients without interferon-beta. However, this effect is not specific enough concerning all lymphocyte subsets influencing the autoimmune response, since it also affects anti-inflammatory Th2 cells.
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Affiliation(s)
- Gergely Toldi
- First Department of Pediatrics, Semmelweis University, Budapest, Bókay u. 53-54, H-1083, Hungary.
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104
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Dalfampridine in multiple sclerosis: from symptomatic treatment to immunomodulation. Clin Immunol 2011; 142:84-92. [PMID: 21742559 DOI: 10.1016/j.clim.2011.06.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 06/16/2011] [Accepted: 06/17/2011] [Indexed: 01/08/2023]
Abstract
Multiple sclerosis (MS) is a neurodegenerative disease that is deemed to affect more than 2.1 million people worldwide, and for which there is no cure. Early symptoms of MS are believed to result from axonal demyelination leading to slowing or blockade of impulse conduction. The blockade of K+ channels has been proven to improve conduction deficiencies secondary to demyelination in patients with MS. Dalfampridine is a K+ channel blocker that was recently approved by FDA for the symptomatic treatment of ambulation hardship in MS. Understanding the mechanisms by which Dalfampridine exerts its therapeutic effects is a complex issue as it blocks a wide variety of K+ channels that are distributed across multiple cell types in the nervous system but also in the immune system, and because of their molecular identities remaining unknown. This review describes Dalfampridine potential roles at the cellular and molecular levels in MS pathogenesis.
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105
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Tegla CA, Cudrici C, Rozycka M, Soloviova K, Ito T, Singh AK, Khan A, Azimzadeh P, Andrian-Albescu M, Khan A, Niculescu F, Rus V, Judge SIV, Rus H. C5b-9-activated, K(v)1.3 channels mediate oligodendrocyte cell cycle activation and dedifferentiation. Exp Mol Pathol 2011; 91:335-45. [PMID: 21540025 DOI: 10.1016/j.yexmp.2011.04.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 04/13/2011] [Indexed: 12/11/2022]
Abstract
Voltage-gated potassium (K(v)) channels play an important role in the regulation of growth factor-induced cell proliferation. We have previously shown that cell cycle activation is induced in oligodendrocytes (OLGs) by complement C5b-9, but the role of K(v) channels in these cells had not been investigated. Differentiated OLGs were found to express K(v)1.4 channels, but little K(v)1.3. Exposure of OLGs to C5b-9 modulated K(v)1.3 functional channels and increased protein expression, whereas C5b6 had no effect. Pretreatment with the recombinant scorpion toxin rOsK-1, a highly selective K(v)1.3 inhibitor, blocked the expression of K(v)1.3 induced by C5b-9. rOsK-1 inhibited Akt phosphorylation and activation by C5b-9 but had no effect on ERK1 activation. These data strongly suggest a role for K(v)1.3 in controlling the Akt activation induced by C5b-9. Since Akt plays a major role in C5b-9-induced cell cycle activation, we also investigated the effect of inhibiting K(v)1.3 channels on DNA synthesis. rOsK-1 significantly inhibited the DNA synthesis induced by C5b-9 in OLG, indicating that K(v)1.3 plays an important role in the C5b-9-induced cell cycle. In addition, C5b-9-mediated myelin basic protein and proteolipid protein mRNA decay was completely abrogated by inhibition of K(v)1.3 expression. In the brains of multiple sclerosis patients, C5b-9 co-localized with NG2(+) OLG progenitor cells that expressed K(v)1.3 channels. Taken together, these data suggest that K(v)1.3 channels play an important role in controlling C5b-9-induced cell cycle activation and OLG dedifferentiation, both in vitro and in vivo.
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Affiliation(s)
- Cosmin A Tegla
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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106
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Ion channels in autoimmune neurodegeneration. FEBS Lett 2011; 585:3836-42. [DOI: 10.1016/j.febslet.2011.03.065] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 03/26/2011] [Accepted: 03/28/2011] [Indexed: 11/23/2022]
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107
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Wulff H. Spiro azepane-oxazolidinones as Kv1.3 potassium channel blockers: WO2010066840. Expert Opin Ther Pat 2010; 20:1759-65. [PMID: 20954790 DOI: 10.1517/13543776.2010.528392] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
This article evaluates a patent application from Solvay Pharmaceuticals, which claims spiro azepane-oxazolidinones as novel blockers of the voltage-gated potassium channel Kv1.3 for the treatment of diabetes, psoriasis, obesity, transplant rejection and T-cell mediated autoimmune diseases such as rheumatoid arthritis and MS. The patent describes a new chemotype of Kv1.3 blockers and thus illustrates the growing interest of the pharmaceutical industry in Kv1.3 as a target of immunosuppression and metabolic disorders. This article briefly summarizes the chemistry and biological data provided in the patent and then compares the new compounds to Kv1.3 blockers previously disclosed by both academia and pharmaceutical companies.
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Affiliation(s)
- Heike Wulff
- University of California, Department of Pharmacology, Davis, Davis, CA 95616, USA.
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108
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Saikali P, Antel JP, Pittet CL, Newcombe J, Arbour N. Contribution of astrocyte-derived IL-15 to CD8 T cell effector functions in multiple sclerosis. THE JOURNAL OF IMMUNOLOGY 2010; 185:5693-703. [PMID: 20926794 DOI: 10.4049/jimmunol.1002188] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The contribution of local factors to the activation of immune cells infiltrating the CNS of patients with multiple sclerosis (MS) remains to be defined. The cytokine IL-15 is pivotal in the maintenance and activation of CD8 T lymphocytes, a prominent lymphocyte population found in MS lesions. We investigated whether astrocytes are a functional source of IL-15 sufficient to enhance CD8 T lymphocyte responses and whether they provide IL-15 in the inflamed CNS of patients with MS. We observed that human astrocytes in primary cultures increased surface IL-15 levels upon activation with combinations of proinflammatory cytokines. Expanded human myelin autoreactive CD8 T lymphocytes cultured with such activated astrocytes displayed elevated lytic enzyme content, NKG2D expression, and Ag-specific cytotoxicity. These functional enhancements were abrogated by anti-IL-15-blocking Abs. Immunohistochemical analysis of brain tissue sections obtained from patients with MS demonstrated colocalization for IL-15 and the astrocyte marker glial fibrillary acidic protein within white matter lesions. The majority of astrocytes (80-90%) present in demyelinating MS lesions expressed IL-15, whereas few astrocytes in normal control brain sections had detectable IL-15. IL-15 could be detected in the majority of Iba-1-expressing microglia in the control sections, albeit in lower numbers when compared with microglia/macrophages in MS lesions. Furthermore, infiltrating CD8 T lymphocytes in MS lesions were in close proximity to IL-15-expressing cells. Astrocyte production of IL-15 resulting in the activation of CD8 T lymphocytes ascribes a role for these cells as contributors to the exacerbation of tissue damage during MS pathogenesis.
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Affiliation(s)
- Philippe Saikali
- Département de Médecine, Université de Montréal, Centre de Recherche du Centre Hospitalier de l'Université de Montréal-Notre-Dame Hospital, Montreal, Quebec, Canada
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109
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A novel role for Kv1.3 blockers: protecting neural progenitor cells from a hostile inflammatory environment. J Neurosci 2010; 30:10609-11. [PMID: 20702693 DOI: 10.1523/jneurosci.2802-10.2010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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110
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Hyodo T, Oda T, Kikuchi Y, Higashi K, Kushiyama T, Yamamoto K, Yamada M, Suzuki S, Hokari R, Kinoshita M, Seki S, Fujinaka H, Yamamoto T, Miura S, Kumagai H. Voltage-gated potassium channel Kv1.3 blocker as a potential treatment for rat anti-glomerular basement membrane glomerulonephritis. Am J Physiol Renal Physiol 2010; 299:F1258-69. [PMID: 20810612 DOI: 10.1152/ajprenal.00374.2010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The voltage-gated potassium channel Kv1.3 has been recently identified as a molecular target that allows the selective pharmacological suppression of effector memory T cells (T(EM)) without affecting the function of naïve T cells (T(N)) and central memory T cells (T(CM)). We found that Kv1.3 was expressed on glomeruli and some tubules in rats with anti-glomerular basement membrane glomerulonephritis (anti-GBM GN). A flow cytometry analysis using kidney cells revealed that most of the CD4(+) T cells and some of the CD8(+) T cells had the T(EM) phenotype (CD45RC(-)CD62L(-)). Double immunofluorescence staining using mononuclear cell suspensions isolated from anti-GBM GN kidney showed that Kv1.3 was expressed on T cells and some macrophages. We therefore investigated whether the Kv1.3 blocker Psora-4 can be used to treat anti-GBM GN. Rats that had been given an injection of rabbit anti-rat GBM antibody were also injected with Psora-4 or the vehicle intraperitoneally. Rats given Psora-4 showed less proteinuria and fewer crescentic glomeruli than rats given the vehicle. These results suggest that T(EM) and some macrophages expressing Kv1.3 channels play a critical role in the pathogenesis of crescentic GN and that Psora-4 will be useful for the treatment of rapidly progressive glomerulonephritis.
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Affiliation(s)
- Toshitake Hyodo
- Dept. of Nephrology, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan.
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111
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The beneficial effect of blocking Kv1.3 in the psoriasiform SCID mouse model. J Invest Dermatol 2010; 131:118-24. [PMID: 20739949 DOI: 10.1038/jid.2010.245] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The Kv1.3 channel is important in the activation and function of effector memory T cells. Recently, specific blockers of the Kv1.3 channel have been developed as a potential therapeutic option for diverse autoimmune diseases. In psoriatic lesions, most lymphocytes are memory effector T cells. The aim of the present study was to detect the expression of Kv1.3 channels in these cells in psoriatic lesions as well as in human psoriasiform skin grafts using the severe combined immunodeficient (SCID) mouse model. Histological and immunohistochemical staining for Kv1.3 expression and various inflammatory markers was performed in sections obtained from six psoriatic patients and 18 beige-SCID mice with psoriasiform human skin grafts. Six grafted mice were treated with Stichodactyla helianthus neurotoxin (ShK), a known Kv1.3 blocker. The results showed an increased number of Kv1.3+ cells in the psoriatic skin as well as in the psoriasiform skin grafts as compared with normal skin and normal skin grafts. Injections of ShK showed a marked therapeutic effect in three of six psoriasiform skin grafts. A significantly decreased number of Kv1.3+ cells was observed in the responders compared with the control grafts. This pilot study, although performed in a small number of mice, reveals the possible beneficial effect of Kv1.3 blockers in psoriasis patients.
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112
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Bittner S, Bobak N, Herrmann AM, Göbel K, Meuth P, Höhn KG, Stenner MP, Budde T, Wiendl H, Meuth SG. Upregulation of K2P5.1 potassium channels in multiple sclerosis. Ann Neurol 2010; 68:58-69. [PMID: 20582984 DOI: 10.1002/ana.22010] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Activation of T cells critically depends on potassium channels. We here characterize the impact of K(2P)5.1 (KCNK5; TASK2), a member of the 2-pore domain family of potassium channels, on T-cell function and demonstrate its putative relevance in a T-cell-mediated autoimmune disorder, multiple sclerosis (MS). METHODS Expression of K(2P)5.1 was investigated on RNA and protein level in different immune cells and in MS patients' biospecimens (peripheral blood mononuclear cells, cerebrospinal fluid cells, brain tissue specimen). Functional consequences of K(2P)5.1 expression were analyzed using pharmacological modulation, small interfering RNA (siRNA), overexpression, electrophysiological recordings, and computer modeling. RESULTS Human T cells constitutively express K(2P)5.1. After T-cell activation, a significant and time-dependent upregulation of K(2P)5.1 channel expression was observed. Pharmacological blockade of K(2P)5.1 or knockdown with siRNA resulted in reduced T-cell functions, whereas overexpression of K(2P)5.1 had the opposite effect. Electrophysiological recordings of T cells clearly dissected K(2P)5.1-mediated effects from other potassium channels. The pathophysiological relevance of these findings was demonstrated by a significant K(2P)5.1 upregulation in CD4(+) and CD8(+) T cells in relapsing/remitting MS (RRMS) patients during acute relapses as well as higher levels on CD8(+) T cells of clinically isolated syndrome, RRMS, and secondary progressive multiple sclerosis patients during clinically stable disease. T cells in the cerebrospinal fluid from MS patients exhibit significantly elevated K(2P)5.1 levels. Furthermore, K(2P)5.1-positive T cells can be found in inflammatory lesions in MS tissue specimens. INTERPRETATION Selective targeting of K(2P)5.1 may hold therapeutic promise for MS and putatively other T-cell-mediated disorders.
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Affiliation(s)
- Stefan Bittner
- Department of Neurology, University of Würzburg, Würzburg, Münster, Germany
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113
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Mars LT, Saikali P, Liblau RS, Arbour N. Contribution of CD8 T lymphocytes to the immuno-pathogenesis of multiple sclerosis and its animal models. Biochim Biophys Acta Mol Basis Dis 2010; 1812:151-61. [PMID: 20637863 DOI: 10.1016/j.bbadis.2010.07.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 06/21/2010] [Accepted: 07/06/2010] [Indexed: 12/17/2022]
Abstract
Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS) characterized by multi-focal demyelination, axonal loss, and immune cell infiltration. Numerous immune mediators are detected within MS lesions, including CD4(+) and CD8(+) T lymphocytes suggesting that they participate in the related pathogenesis. Although CD4(+) T lymphocytes are traditionally considered the main actors in MS immunopathology, multiple lines of evidence suggest that CD8(+) T lymphocytes are also implicated in the pathogenesis. In this review, we outline the recent literature pertaining to the potential roles of CD8(+) T lymphocytes both in MS and its animal models. The CD8(+) T lymphocytes detected in MS lesions demonstrate characteristics of activated and clonally expanded cells supporting the notion that these cells actively contribute to the observed injury. Moreover, several experimental in vivo models mediated by CD8(+) T lymphocytes recapitulate important features of the human disease. Whether the CD8(+) T cells can induce or aggravate tissue destruction in the CNS needs to be fully explored. Strengthening our understanding of the pathogenic potential of CD8(+) T cells in MS should provide promising new avenues for the treatment of this disabling inflammatory disease.
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Affiliation(s)
- Lennart T Mars
- INSERM, U563, Centre de Physiopathologie de Toulouse Purpan, Hôpital Purpan, Toulouse, F-31300, France; Université Toulouse III, Paul-Sabatier, Toulouse, F-31400, France
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114
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Varga Z, Hajdu P, Panyi G. Ion channels in T lymphocytes: An update on facts, mechanisms and therapeutic targeting in autoimmune diseases. Immunol Lett 2010; 130:19-25. [DOI: 10.1016/j.imlet.2009.12.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 12/08/2009] [Accepted: 12/10/2009] [Indexed: 12/31/2022]
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115
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Rangaraju S, Chi V, Pennington MW, Chandy KG. Kv1.3 potassium channels as a therapeutic target in multiple sclerosis. Expert Opin Ther Targets 2010; 13:909-24. [PMID: 19538097 DOI: 10.1517/14728220903018957] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We discuss the potential use of inhibitors of Kv1.3 potassium channels in T lymphocytes as therapeutics for multiple sclerosis. Current treatment strategies target the immune system in a non-selective manner. The resulting general immunosuppression, toxic side-effects and increased risk of opportunistic infections create the need for more selective therapeutics. Autoreactive effector-memory T (T(EM)) cells, considered to be major mediators of autoimmunity, express large numbers of Kv1.3 channels. Selective blockers of Kv1.3 inhibit calcium signaling, cytokine production and proliferation of T(EM) cells in vitro, and T(EM) cell-motility in vivo. Kv1.3 blockers ameliorate disease in animal models of multiple sclerosis, rheumatoid arthritis, type 1 diabetes mellitus and contact dermatitis without compromising the protective immune response to acute infections. Kv1.3 blockers have a good safety profile in rodents and primates.
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Affiliation(s)
- Srikant Rangaraju
- University of California, Department of Physiology and Biophysics, Irvine, California 92697, USA
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116
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Husseini L, Leussink VI, Kieseier BC, Hartung HP. [4-Aminopyridine (Fampridine). A new attempt for the symptomatic treatment of multiple sclerosis]. DER NERVENARZT 2010; 81:203-211. [PMID: 20112006 DOI: 10.1007/s00115-009-2902-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Mobility limitation is a frequent clinical symptom of multiple sclerosis (MS) that poses a therapeutic challenge. For years results of animal experiments and clinical experience have indicated that the potassium channel blocker 4-aminopyridine improves axonal excitatory circuits and thus muscular strength in demyelinating diseases. A recently conducted randomized, placebo-controlled, multicenter phase 3 clinical trial in MS patients was able to show that an oral sustained-release formulation of 4-aminopyridine (Fampridine-SR) represents a suitable agent for treatment of walking disability in MS patients.This overview presents the study data and discusses the value of 4-aminopyridine for the symptomatic treatment of MS as a neurofunctional modifier of this disabling disease.
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Affiliation(s)
- L Husseini
- Neurologische Klinik, Heinrich-Heine-Universität Düsseldorf, Moorenstrasse 5, Düsseldorf, Germany
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117
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TNF-α inhibits the CD3-mediated upregulation of voltage-gated K+ channel (Kv1.3) in human T cells. Biochem Biophys Res Commun 2010; 391:909-14. [DOI: 10.1016/j.bbrc.2009.11.162] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Accepted: 11/25/2009] [Indexed: 01/15/2023]
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118
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Abstract
The human genome encodes 40 voltage-gated K(+) channels (K(V)), which are involved in diverse physiological processes ranging from repolarization of neuronal and cardiac action potentials, to regulating Ca(2+) signalling and cell volume, to driving cellular proliferation and migration. K(V) channels offer tremendous opportunities for the development of new drugs to treat cancer, autoimmune diseases and metabolic, neurological and cardiovascular disorders. This Review discusses pharmacological strategies for targeting K(V) channels with venom peptides, antibodies and small molecules, and highlights recent progress in the preclinical and clinical development of drugs targeting the K(V)1 subfamily, the K(V)7 subfamily (also known as KCNQ), K(V)10.1 (also known as EAG1 and KCNH1) and K(V)11.1 (also known as HERG and KCNH2) channels.
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119
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Abstract
For more than 25 years, it has been widely appreciated that Ca2+ influx is essential to trigger T-lymphocyte activation. Patch clamp analysis, molecular identification, and functional studies using blockers and genetic manipulation have shown that a unique contingent of ion channels orchestrates the initiation, intensity, and duration of the Ca2+ signal. Five distinct types of ion channels--Kv1.3, KCa3.1, Orai1+ stromal interacting molecule 1 (STIM1) [Ca2+-release activating Ca2+ (CRAC) channel], TRPM7, and Cl(swell)--comprise a network that performs functions vital for ongoing cellular homeostasis and for T-cell activation, offering potential targets for immunomodulation. Most recently, the roles of STIM1 and Orai1 have been revealed in triggering and forming the CRAC channel following T-cell receptor engagement. Kv1.3, KCa3.1, STIM1, and Orai1 have been found to cluster at the immunological synapse following contact with an antigen-presenting cell; we discuss how channels at the synapse might function to modulate local signaling. Immuno-imaging approaches are beginning to shed light on ion channel function in vivo. Importantly, the expression pattern of Ca2+ and K+ channels and hence the functional network can adapt depending upon the state of differentiation and activation, and this allows for different stages of an immune response to be targeted specifically.
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Affiliation(s)
- Michael D Cahalan
- Department of Physiology and Biophysics, and the Institute for Immunology, University of California, Irvine, Irvine, CA 92697-4561, USA.
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120
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Keblesh JP, Dou H, Gendelman HE, Xiong H. 4-Aminopyridine improves spatial memory in a murine model of HIV-1 encephalitis. J Neuroimmune Pharmacol 2009; 4:317-27. [PMID: 19462247 PMCID: PMC3106106 DOI: 10.1007/s11481-009-9161-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Accepted: 05/08/2009] [Indexed: 11/24/2022]
Abstract
HIV-1-associated neurocognitive disorders (HAND) remains a significant source of morbidity in the era of wide spread use of highly active antiretroviral therapy. Disease is precipitated by low levels of viral growth and glial immune activation within the central nervous system. Blood borne macrophage and microglia affect a proinflammatory response and release viral proteins that affects neuronal viability and leads to death of nerve cells. Increasing evidence supports the notion that HAND is functional channelopathy, but proof of this concept remains incomplete. Based on their role in learning and memory processes, we now posit that voltage-gated potassium (K(v)) channels could be a functional substrate for disease. This was tested in the severe combined immunodeficient (SCID) mouse model of HIV-1 encephalitis (HIVE) by examining whether the K(v) channel blocker, 4-aminopyridine (4-AP), could affect behavioral, electrophysiological, and morphological measures of learning and memory. HIVE SCID mice showed impaired spatial memory in radial arm water maze tests. Electrophysiology studies revealed a reduction of long-term potentiation (LTP) in the CA1 region of the hippocampus. Importantly, systemic administration of 4-AP blocked HIV-1-associated reduction of LTP and improved animal performance in the radial arm water maze. These results support the importance of K(v) channel dysfunction in disease but, more importantly, provide a potential target for adjunctive therapies for HAND.
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Affiliation(s)
- James P Keblesh
- Neurophysiology Laboratory, University of Nebraska Medical Center, Omaha, NE 68198-5880, USA
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Kummerow C, Junker C, Kruse K, Rieger H, Quintana A, Hoth M. The immunological synapse controls local and global calcium signals in T lymphocytes. Immunol Rev 2009; 231:132-47. [DOI: 10.1111/j.1600-065x.2009.00811.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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122
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Varga Z, Csepany T, Papp F, Fabian A, Gogolak P, Toth A, Panyi G. Potassium channel expression in human CD4+ regulatory and naïve T cells from healthy subjects and multiple sclerosis patients. Immunol Lett 2009; 124:95-101. [DOI: 10.1016/j.imlet.2009.04.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 04/17/2009] [Accepted: 04/23/2009] [Indexed: 10/20/2022]
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Oguchi T, Watanabe K, Ohkubo K, Abe H, Katoh T. Enantioselective total synthesis of (-)-candelalides A, B and C: potential Kv1.3 blocking immunosuppressive agents. Chemistry 2009; 15:2826-45. [PMID: 19191240 DOI: 10.1002/chem.200802122] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Novel Kv1.3 blocking immunosuppressants, (-)-candelalides A, B and C, were efficiently synthesized for the first time in a convergent and unified manner starting from (+)-5-methyl-Wieland-Miescher ketone. The synthetic method involved the following key steps: i) a strategic [2,3]-Wittig rearrangement of a stannylmethyl ether to install the stereogenic center at C9 and the exo-methylene function at C8 present in the decalin portion; ii) a straightforward coupling of a trans-decalin portion (BC ring) and a gamma-pyrone moiety through the C16-C3' bond to assemble the requisite carbon framework; and iii) a construction of a characteristic di or tetrahydropyran ring (A ring) by internal nucleophilic ring closure of a hydroxy aldehyde or a hydroxy epoxide. The present total synthesis has fully established the absolute configuration of these natural products.
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Affiliation(s)
- Takamasa Oguchi
- Laboratory of Synthetic Medicinal Chemistry, Department of Chemical Pharmaceutical Science, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, 981-8558, Japan
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124
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Hu X, Gu Y, Wang Y, Cong Y, Qu X, Xu C. Increased CD4+ and CD8+ effector memory T cells in patients with aplastic anemia. Haematologica 2009; 94:428-9. [PMID: 19181780 DOI: 10.3324/haematol.13412] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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125
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Pennington MW, Beeton C, Galea CA, Smith BJ, Chi V, Monaghan KP, Garcia A, Rangaraju S, Giuffrida A, Plank D, Crossley G, Nugent D, Khaytin I, Lefievre Y, Peshenko I, Dixon C, Chauhan S, Orzel A, Inoue T, Hu X, Moore RV, Norton RS, Chandy KG. Engineering a stable and selective peptide blocker of the Kv1.3 channel in T lymphocytes. Mol Pharmacol 2009; 75:762-73. [PMID: 19122005 DOI: 10.1124/mol.108.052704] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Kv1.3 potassium channels maintain the membrane potential of effector memory (T(EM)) T cells that are important mediators of multiple sclerosis, type 1 diabetes mellitus, and rheumatoid arthritis. The polypeptide ShK-170 (ShK-L5), containing an N-terminal phosphotyrosine extension of the Stichodactyla helianthus ShK toxin, is a potent and selective blocker of these channels. However, a stability study of ShK-170 showed minor pH-related hydrolysis and oxidation byproducts that were exacerbated by increasing temperatures. We therefore engineered a series of analogs to minimize the formation of these byproducts. The analog with the greatest stability, ShK-192, contains a nonhydrolyzable phosphotyrosine surrogate, a methionine isostere, and a C-terminal amide. ShK-192 shows the same overall fold as ShK, and there is no evidence of any interaction between the N-terminal adduct and the rest of the peptide. The docking configuration of ShK-192 in Kv1.3 shows the N-terminal para-phosphonophenylalanine group lying at the junction of two channel monomers to form a salt bridge with Lys(411) of the channel. ShK-192 blocks Kv1.3 with an IC(50) of 140 pM and exhibits greater than 100-fold selectivity over closely related channels. After a single subcutaneous injection of 100 microg/kg, approximately 100 to 200 pM concentrations of active peptide is detectable in the blood of Lewis rats 24, 48, and 72 h after the injection. ShK-192 effectively inhibits the proliferation of T(EM) cells and suppresses delayed type hypersensitivity when administered at 10 or 100 microg/kg by subcutaneous injection once daily. ShK-192 has potential as a therapeutic for autoimmune diseases mediated by T(EM) cells.
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Affiliation(s)
- M W Pennington
- Bachem Bioscience Inc., King of Prussia, Pennsylvania, USA
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126
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Ren YR, Pan F, Parvez S, Fleig A, Chong CR, Xu J, Dang Y, Zhang J, Jiang H, Penner R, Liu JO. Clofazimine inhibits human Kv1.3 potassium channel by perturbing calcium oscillation in T lymphocytes. PLoS One 2008; 3:e4009. [PMID: 19104661 PMCID: PMC2602975 DOI: 10.1371/journal.pone.0004009] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2008] [Accepted: 11/08/2008] [Indexed: 01/03/2023] Open
Abstract
The Kv1.3 potassium channel plays an essential role in effector memory T cells and has been implicated in several important autoimmune diseases including multiple sclerosis, psoriasis and type 1 diabetes. A number of potent small molecule inhibitors of Kv1.3 channel have been reported, some of which were found to be effective in various animal models of autoimmune diseases. We report herein the identification of clofazimine, a known anti-mycobacterial drug, as a novel inhibitor of human Kv1.3. Clofazimine was initially identified as an inhibitor of intracellular T cell receptor-mediated signaling leading to the transcriptional activation of human interleukin-2 gene in T cells from a screen of the Johns Hopkins Drug Library. A systematic mechanistic deconvolution revealed that clofazimine selectively blocked the Kv1.3 channel activity, perturbing the oscillation frequency of the calcium-release activated calcium channel, which in turn led to the inhibition of the calcineurin-NFAT signaling pathway. These effects of clofazimine provide the first line of experimental evidence in support of a causal relationship between Kv1.3 and calcium oscillation in human T cells. Furthermore, clofazimine was found to be effective in blocking human T cell-mediated skin graft rejection in an animal model in vivo. Together, these results suggest that clofazimine is a promising immunomodulatory drug candidate for treating a variety of autoimmune disorders.
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Affiliation(s)
- Yunzhao R. Ren
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Program in Biochemistry, Cellular and Molecular Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Fan Pan
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Suhel Parvez
- Center for Biomedical Research at The Queen's Medical Center and John A. Burns School of Medicine at the University of Hawaii, Honolulu, Hawaii, United States of America
| | - Andrea Fleig
- Center for Biomedical Research at The Queen's Medical Center and John A. Burns School of Medicine at the University of Hawaii, Honolulu, Hawaii, United States of America
| | - Curtis R. Chong
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Jing Xu
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Yongjun Dang
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Jin Zhang
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Hongsi Jiang
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Evanston, Illinois, United States of America
| | - Reinhold Penner
- Center for Biomedical Research at The Queen's Medical Center and John A. Burns School of Medicine at the University of Hawaii, Honolulu, Hawaii, United States of America
| | - Jun O. Liu
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Program in Biochemistry, Cellular and Molecular Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
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127
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Monocyte chemotactic protein-1 regulates voltage-gated K+ channels and macrophage transmigration. J Neuroimmune Pharmacol 2008; 4:47-59. [PMID: 19034671 DOI: 10.1007/s11481-008-9135-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Accepted: 10/31/2008] [Indexed: 10/21/2022]
Abstract
Progressive human immunodeficiency virus (HIV)-1 infection and virus-induced neuroinflammatory responses effectuate monocyte-macrophage transmigration across the blood-brain barrier (BBB). A key factor in mediating these events is monocyte chemotactic protein-1 (MCP-1). Upregulated glial-derived MCP-1 in HIV-1-infected brain tissues generates a gradient for monocyte recruitment into the nervous system. We posit that the inter-relationships between MCP-1, voltage-gated ion channels, cell shape and volume, and cell mobility underlie monocyte transmigration across the BBB. In this regard, MCP-1 serves both as a chemoattractant and an inducer of monocyte-macrophage ion flux affecting cell shape and mobility. To address this hypothesis, MCP-1-treated bone marrow-derived macrophages (BMM) were analyzed for gene and protein expression, electrophysiology, and capacity to migrate across a laboratory constructed BBB. MCP-1 enhanced K+ channel gene (KCNA3) and channel protein expression. Electrophysiological studies revealed that MCP-1 increased outward K+ currents in a dose-dependent manner. In vitro studies demonstrated that MCP-1 increased BMM migration across an artificial BBB, and the MCP-1-induced BMM migration was blocked by tetraethylammonium, a voltage-gated K+ channel blocker. Together these data demonstrated that MCP-1 affects macrophage migratory movement through regulation of voltage-gated K+ channels and, as such, provides a novel therapeutic strategy for neuroAIDS.
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128
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Bodendiek SB, Mahieux C, Hänsel W, Wulff H. 4-Phenoxybutoxy-substituted heterocycles--a structure-activity relationship study of blockers of the lymphocyte potassium channel Kv1.3. Eur J Med Chem 2008; 44:1838-52. [PMID: 19056148 DOI: 10.1016/j.ejmech.2008.10.033] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 10/25/2008] [Accepted: 10/30/2008] [Indexed: 10/21/2022]
Abstract
The voltage-gated potassium channel Kv1.3 constitutes an attractive pharmacological target for the treatment of effector memory T cell-mediated autoimmune diseases such as multiple sclerosis and psoriasis. Using 5-methoxypsoralen (5-MOP, 1), a compound isolated from Ruta graveolens, as a template we previously synthesized 5-(4-phenoxybutoxy)psoralen (PAP-1, 2) which inhibits Kv1.3 with an IC(50) of 2nM. Since PAP-1 is more than 1000-fold more potent than 5-MOP, we here investigated whether attaching a 4-phenoxybutoxy side chain to other heterocyclic systems would also produce potent Kv1.3 blockers. While 4-phenoxybutoxy-substituted quinolines, quinazolines and phenanthrenes were inactive, 4-phenoxybutoxy-substituted quinolinones, furoquinolines, coumarins or furochromones inhibited Kv1.3 with IC(50)s of 150 nM to 10 microM in whole-cell patch-clamp experiments. Our most potent new compound is 4-(4-phenoxybutoxy)-7H-furo[3,2-g]chromene-7-thione (73, IC(50) 17 nM), in which the carbonyl oxygen of PAP-1 is replaced by sulfur. Taken together, our results demonstrate that the psoralen system is a crucial part of the pharmacophore of phenoxyalkoxypsoralen-type Kv1.3 blockers.
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Affiliation(s)
- Silke B Bodendiek
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Sciences Facility, 451 Health Sciences Drive, Davis, CA 95616, USA
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129
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Matheu MP, Beeton C, Garcia A, Chi V, Rangaraju S, Safrina O, Monaghan K, Uemura MI, Li D, Pal S, de la Maza LM, Monuki E, Flügel A, Pennington MW, Parker I, Chandy KG, Cahalan MD. Imaging of effector memory T cells during a delayed-type hypersensitivity reaction and suppression by Kv1.3 channel block. Immunity 2008; 29:602-14. [PMID: 18835197 DOI: 10.1016/j.immuni.2008.07.015] [Citation(s) in RCA: 167] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 12/03/2007] [Accepted: 07/09/2008] [Indexed: 01/07/2023]
Abstract
Effector memory T (Tem) cells are essential mediators of autoimmune disease and delayed-type hypersensitivity (DTH), a convenient model for two-photon imaging of Tem cell participation in an inflammatory response. Shortly (3 hr) after entry into antigen-primed ear tissue, Tem cells stably attached to antigen-bearing antigen-presenting cells (APCs). After 24 hr, enlarged Tem cells were highly motile along collagen fibers and continued to migrate rapidly for 18 hr. Tem cells rely on voltage-gated Kv1.3 potassium channels to regulate calcium signaling. ShK-186, a specific Kv1.3 blocker, inhibited DTH and suppressed Tem cell enlargement and motility in inflamed tissue but had no effect on homing to or motility in lymph nodes of naive and central memory T (Tcm) cells. ShK-186 effectively treated disease in a rat model of multiple sclerosis. These results demonstrate a requirement for Kv1.3 channels in Tem cells during an inflammatory immune response in peripheral tissues. Targeting Kv1.3 allows for effector memory responses to be suppressed while central memory responses remain intact.
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Affiliation(s)
- Melanie P Matheu
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697-4561, USA
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130
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Han S, Yi H, Yin SJ, Chen ZY, Liu H, Cao ZJ, Wu YL, Li WX. Structural Basis of a Potent Peptide Inhibitor Designed for Kv1.3 Channel, a Therapeutic Target of Autoimmune Disease. J Biol Chem 2008; 283:19058-65. [DOI: 10.1074/jbc.m802054200] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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131
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Estes DJ, Memarsadeghi S, Lundy SK, Marti F, Mikol DD, Fox DA, Mayer M. High-throughput profiling of ion channel activity in primary human lymphocytes. Anal Chem 2008; 80:3728-35. [PMID: 18433147 DOI: 10.1021/ac800164v] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present a high-throughput method to quantify the functional activity of potassium (K (+)) ion channels in primary human lymphocytes. This method is rapid, automated, specific (here for the voltage-gated Kv1.3 ion channel), and capable of measuring, in parallel, the electrical currents of over 200 individual lymphocytes isolated from freshly drawn blood. The statistics afforded by high-throughput measurements allowed direct comparison of Kv1.3 activity in different subsets of lymphocytes, including CD4 (+) and CD8 (+) T cells, gammadelta T cells, and B cells. High-throughput measurements made it possible to quantify the heterogeneous, functional response of Kv1.3 ion channel activity upon stimulation of CD4 (+) and CD8 (+) T cells with mitogen. These experiments enabled elucidation of time-courses of functional Kv1.3 activity upon stimulation as well as studies of the effects of the concentration of mitogenic antibodies on Kv1.3 levels. The results presented here suggest that Kv1.3 ion channel activity can be used as a functional activation marker in T cells and that it correlates to cell size and levels of a surface antigen, CD25. Moreover, this work presents an enabling methodology that can be applied widely, allowing high-throughput screening of specific voltage-gated ion channels in a variety of primary cells.
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Affiliation(s)
- Daniel J Estes
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
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132
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Wulff H, Zhorov BS. K+ channel modulators for the treatment of neurological disorders and autoimmune diseases. Chem Rev 2008; 108:1744-73. [PMID: 18476673 PMCID: PMC2714671 DOI: 10.1021/cr078234p] [Citation(s) in RCA: 168] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Heike Wulff
- Department of Pharmacology, University of California, Davis, California 95616, USA.
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133
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Keblesh JP, Reiner BC, Liu J, Xiong H. Pathogenesis of Human Immunodeficiency Virus Type-1 (HIV-1)-Associated Dementia: Role of Voltage-Gated Potassium Channels. RETROVIROLOGY : RESEARCH AND TREATMENT 2008; 2:1-10. [PMID: 20651955 PMCID: PMC2908044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
HIV-1-associated dementia (HAD) describes the cognitive impairments and behavioral disturbances which afflict many HIV-infected individuals. Although the incidence of HAD has decreased significantly in the era of HAART, it remains a significant complication of HIV-1 infection as patients with acquired immune deficient syndrome (AIDS) live longer, antiretroviral drugs remain unable to effectively cross the blood-brain barrier (BBB), and HIV-1 resistance grows due to viral strain mutation. Although the precise mechanism leading to HAD is incompletely understood, it is commonly accepted its progression involves a critical mass of infected and activated mononuclear phagocytes (MP; brain perivascular macrophages and microglia) releasing immune and viral products in brain. These cellular and viral products induce neuronal dysfunction and injury via various signaling pathways. Emerging evidence indicates that voltage-gated potassium (K(v)) channels, key regulators of cell excitability and animal behavior (learning and memory), are involved in the pathogenesis of HAD/HAND. Here we survey the literature and find HAD related alterations in cellular and viral products can alter MP and neuronal K(v) channel activity, leading to MP and neuronal dysfunction and cognitive deficits. Thus, MP and neuronal K(v) channels may be a new target in the effort to develop therapies for HAD and perhaps other inflammatory neurodegenerative disorders.
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134
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Shumilina E, Zahir N, Xuan NT, Lang F. Phosphoinositide 3-kinase dependent regulation of Kv channels in dendritic cells. Cell Physiol Biochem 2007; 20:801-8. [PMID: 17982262 DOI: 10.1159/000110440] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2007] [Indexed: 12/17/2022] Open
Abstract
The phosphoinositide 3 (PI3) kinase plays a pivotal role in the regulation of dendritic cells (DCs), antigen-presenting cells that are able to initiate primary immune responses and to establish immunological memory. PI3 kinase is an endogenous suppressor of interleukin 12 (IL-12) production in DCs that is triggered by Toll-like receptor signaling. Inhibition of IL-12 production limits T helper 1 (Th1) polarization. On the other hand, PI3 kinase is an important regulator of various ion channels. The present study aimed to explore whether ion channels in DCs are regulated by PI3 kinase and whether they are important for DC function. To this end, DCs were isolated from murine bone marrow and ion channel activity was determined by patch clamp. As a result, DCs express voltage-gated K(+) channels (Kv), which are blocked by Stichodactyla helianthus toxin (ShK, 2.5 nM). A significant upregulation of Kv currents was observed upon maturation of DCs as induced by stimulation of the cells with lipopolysaccharide (LPS, 0.1 microg/ml, 48 h). A dramatic increase of Kv current amplitude was observed following preincubation of the cells with LY294002 (100 nM), a specific inhibitor of PI3 kinase. PI3 kinase inhibitor wortmannin (100 nM) similarly increased Kv current. LY294002 treatment was further followed by a significant increase of IL-12 production. ShK (100 nM) significantly blunted the stimulation of IL-12 release by LPS but not when the cells were first pretreated with LY294002. The observations point to Kv channel sensitive and Kv channel insensitive regulation of DC function.
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135
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Bielecki B, Mazurek A, Wolinski P, Glabinski A. Expression of chemokine receptors CCR7 and CCR8 in the CNS during ChREAE. Scand J Immunol 2007; 66:383-92. [PMID: 17850582 DOI: 10.1111/j.1365-3083.2007.01954.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Chemokines and their receptors are important players in organism homeostasis, development and immune response to inflammatory stimuli. It has been recently confirmed that they are also involved in the development of several autoimmune diseases. In this study, we analysed the expression of two recently identified CC chemokine receptors, CCR7 and CCR8, in the central nervous system (CNS) and in peripheral tissues during chronic relapsing experimental autoimmune encephalomyelitis (ChREAE) -- an animal model of the human demyelinating disease multiple sclerosis (MS). We observed upregulation of both chemokine receptors in the CNS during the first and second attacks of ChREAE, whereas disease remission was characterized by a lower expression of those receptors. An analysis of the kinetics of CCR7 and CCR8 expression in the CNS during the first attack of the disease showed a constant increase in the first few days after the onset of clinical signs. This expression correlated with the clinical severity of ChREAE. CCR7-positive mononuclear cells were detected mostly in perivascular inflammatory cuffs in the CNS. In peripheral tissues (the spleen and kidneys) expression of both receptors was not upregulated during active ChREAE. These findings suggest that CCR7 and CCR8 may play a significant role in the pathogenesis of EAE and probably MS.
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MESH Headings
- Animals
- Brain/immunology
- Central Nervous System/immunology
- Chronic Disease
- Disease Models, Animal
- Encephalomyelitis, Autoimmune, Experimental/genetics
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Female
- Image Processing, Computer-Assisted
- Immunohistochemistry
- Mice
- Multiple Sclerosis/genetics
- Multiple Sclerosis/immunology
- Receptors, CCR7
- Receptors, CCR8
- Receptors, Chemokine/biosynthesis
- Receptors, Chemokine/genetics
- Receptors, Chemokine/immunology
- Spinal Cord/immunology
- Statistics, Nonparametric
- Up-Regulation
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Affiliation(s)
- B Bielecki
- Department of Experimental and Clinical Neurology, Medical University of Lodz, Lodz, Poland
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136
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Hu L, Pennington M, Jiang Q, Whartenby KA, Calabresi PA. Characterization of the functional properties of the voltage-gated potassium channel Kv1.3 in human CD4+ T lymphocytes. THE JOURNAL OF IMMUNOLOGY 2007; 179:4563-70. [PMID: 17878353 DOI: 10.4049/jimmunol.179.7.4563] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Previous studies have shown that central memory T (T(CM)) cells predominantly use the calcium-dependent potassium channel KCa3.1 during acute activation, whereas effector memory T (T(EM)) cells use the voltage-gated potassium channel Kv1.3. Because Kv1.3-specific pharmacological blockade selectively inhibited anti-CD3-mediated proliferation, whereas naive T cells and T(CM) cells escaped inhibition due to up-regulation of KCa3.1, this difference indicated a potential for selective targeting of the T(EM) population. We examined the effects of pharmacological Kv1.3 blockers and a dominant-negative Kv1.x construct on T cell subsets to assess the specific effects of Kv1.3 blockade. Our studies indicated both T(CM) and T(EM) CD4+ T cells stimulated with anti-CD3 were inhibited by charybdotoxin, which can block both KCa3.1 and Kv1.3, whereas margatoxin and Stichodactyla helianthus toxin, which are more selective Kv1.3 inhibitors, inhibited proliferation and IFN-gamma production only in the T(EM) subset. The addition of anti-CD28 enhanced proliferation of freshly isolated cells and rendered them refractory to S. helianthus, whereas chronically activated T(EM) cell lines appeared to be costimulation independent because Kv1.3 blockers effectively inhibited proliferation and IFN-gamma regardless of second signal. Transduction of CD4+ T cells with dominant-negative Kv1.x led to a higher expression of CCR7+ T(CM) phenotype and a corresponding depletion of T(EM). These data provide further support for Kv1.3 as a selective target of chronically activated T(EM) without compromising naive or T(CM) immune functions. Specific Kv1.3 blockers may be beneficial in autoimmune diseases such as multiple sclerosis in which T(EM) are found in the target organ.
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Affiliation(s)
- Lina Hu
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
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137
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Abstract
The classical field of neuroimmunology deals with the immune response in infectious, autoimmune-mediated, ischemic, degenerative, traumatic, and neoplastic diseases of the nervous system with a major focus on immune-mediated demyelination. Recently more and more evidence points to a broader interaction between the immune and nervous systems via morphological connections, shared signal molecules and common mechanisms of signal transduction. Consequently, immune processes affect nervous functions and vice versa under both physiologic and pathologic conditions. This includes neuroendocrine (hormonal) and vegetative (neurotransmitter-mediated) influences on the immune response including conditioned immunostimulation and immunosuppression (neuroimmunomodulation) as well as effects of immune mediators (cytokines) on neuronal and psychic functions (psychoneuroimmunology). These findings have a strong impact on future strategies for the treatment of somatic as well as psychiatric diseases.
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Affiliation(s)
- Eilhard Mix
- University of Rostock, Department of Neurology, Gehlsheimer Str. 20, 18147, Rostock, Germany
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138
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Gill S, Gill R, Wicks D, Liang D. A cell-based Rb(+)-flux assay of the Kv1.3 potassium channel. Assay Drug Dev Technol 2007; 5:373-80. [PMID: 17638537 DOI: 10.1089/adt.2006.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The Kv1.3 channels expressed by human T lymphocytes are emerging as important therapeutic targets. Peptides like agitoxin and margatoxin in scorpion venom and some non-peptide small molecules are known to inhibit this channel. Since such blockers cannot be used as drugs, pharma has a need to discover effective blockers. The major limiting factor for such development has been the lack of a reliable high-throughput screening (HTS) technology. A cell-based HTS assay for this target was developed in 96-well format to facilitate screening of many candidates. The assay incorporates rubidium ion as a tracer for potassium ion, which can be analyzed by the atomic absorption spectroscopy. The assay provided a Z' factor of 0.813 with more than a 4.5-fold window of detection. The two known blockers agitoxin and margatoxin gave a 50% inhibitory concentration (IC(50)) of 1.52 and 2 nM, respectively. These values are about five- and 2.8-fold higher than their IC(50) values obtained from patch clamp. Some non-peptide compounds like tamoxifen, nifedipine, and fluoxetine also inhibited the efflux through these channels, whereas astemizole and pimozide (potent human ether-a-go-go-related gene blockers) did not block Kv1.3 activity.
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139
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Herrero-Herranz E, Pardo LA, Bunt G, Gold R, Stühmer W, Linker RA. Re-expression of a developmentally restricted potassium channel in autoimmune demyelination: Kv1.4 is implicated in oligodendroglial proliferation. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 171:589-98. [PMID: 17600124 PMCID: PMC1934532 DOI: 10.2353/ajpath.2007.061241] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/20/2007] [Indexed: 12/20/2022]
Abstract
Mechanisms of lesion repair in multiple sclerosis are incompletely understood. To some degree, remyelination can occur, associated with an increase of proliferating oligodendroglial cells. Recently, the expression of potassium channels has been implicated in the control of oligodendrocyte precursor cell proliferation in vitro. We investigated the expression of Kv1.4 potassium channels in myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis, a model of multiple sclerosis. Confocal microscopy revealed expression of Kv1.4 in AN2-positive oligodendrocyte precursor cells and premyelinating oligodendrocytes in vitro but neither in mature oligodendrocytes nor in the spinal cords of healthy adult mice. After induction of myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis, Kv1.4 immunoreactivity was detected in or around lesions already during disease onset with a peak early and a subsequent decrease in the late phase of the disease. Kv1.4 expression was confined to 2',3'-cyclic nucleotide 3'-phosphodiesterase-positive oligodendroglial cells, which were actively proliferating and ensheathed naked axons. After a demyelinating episode, the number of Kv1.4 and 2',3'-cyclic nucleotide 3'-phosphodiesterase double-positive cells was greatly reduced in ciliary neurotrophic factor knockout mice, a model with impaired lesion repair. In summary, the re-expression of an oligodendroglial potassium channel may have a functional implication on oligodendroglial cell cycle progression, thus influencing tissue repair in experimental autoimmune encephalomyelitis and multiple sclerosis.
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MESH Headings
- 2',3'-Cyclic-Nucleotide Phosphodiesterases/genetics
- 2',3'-Cyclic-Nucleotide Phosphodiesterases/metabolism
- Animals
- Axons/chemistry
- Axons/metabolism
- Axons/pathology
- Cell Differentiation
- Cell Proliferation
- Cells, Cultured
- Ciliary Neurotrophic Factor/genetics
- Ciliary Neurotrophic Factor/metabolism
- Encephalomyelitis, Autoimmune, Experimental/genetics
- Encephalomyelitis, Autoimmune, Experimental/metabolism
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Female
- Gene Expression
- Immunohistochemistry
- Kv1.4 Potassium Channel/genetics
- Kv1.4 Potassium Channel/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Microscopy, Confocal
- Multiple Sclerosis/genetics
- Multiple Sclerosis/metabolism
- Multiple Sclerosis/pathology
- Oligodendroglia/cytology
- Oligodendroglia/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Time Factors
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140
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Cudrici C, Ito T, Zafranskaia E, Niculescu F, Mullen KM, Vlaicu S, Judge SIV, Calabresi PA, Rus H. Dendritic cells are abundant in non-lesional gray matter in multiple sclerosis. Exp Mol Pathol 2007; 83:198-206. [PMID: 17662270 PMCID: PMC2066192 DOI: 10.1016/j.yexmp.2007.05.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Revised: 05/23/2007] [Accepted: 05/24/2007] [Indexed: 12/25/2022]
Abstract
We have analyzed the localization of dendritic cells (DCs) in non-lesional gray matter (NLGM) in comparison to non-lesional white matter (NLWM) and acute or chronic active multiple sclerosis (MS) lesions. Immunohistochemistry was performed on cryostat sections for DCs markers (CD209, CD205, CD83) and other markers for inflammatory cells (CD68, CD8, CD4, CD3, CCR7, CCR5). We found cells expressing CD209 and containing myelin basic protein in both perivascular and parenchymal areas of NLGM. Our findings showing the expression of CD209(+) cells in NLGM parenchymal areas are surprising relative to the previous literature which reported the presence of CD209(+) DCs only in MS plaque perivascular areas. Although less numerous than CD209(+) cells, NLGM cells expressing mature DCs marker CD205 were consistently detected in perivascular cuffs of most lesions. In double labeling experiments, some but not all of the CD209(+) cells also expressed CD68 and CCR5. We also found CD209(+) cells in close contact with CD3(+) lymphocytes suggesting that DCs might contribute to the local activation of pathogenic T cells in the NLGM. Since injury to the NLGM is one of the key factors associated with disability accumulation, targeting DCs may represent a possible new therapeutic approach in MS to prevent disease progression.
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Affiliation(s)
| | - Takahiro Ito
- Department of Neurology, University of Maryland, Baltimore, MD
| | | | - Florin Niculescu
- Department of Medicine, Division of Rheumatology and Clinical Immunology, University of Maryland, Baltimore, MD
| | | | - Sonia Vlaicu
- Department of Neurology, University of Maryland, Baltimore, MD
| | - Susan I. V. Judge
- Department of Neurology, University of Maryland, Baltimore, MD
- VAMHCS, MS Center of Excellence-East, Baltimore, MD, United States
| | | | - Horea Rus
- Department of Neurology, University of Maryland, Baltimore, MD
- VAMHCS, MS Center of Excellence-East, Baltimore, MD, United States
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141
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Irvine E, Keblesh J, Liu J, Xiong H. Voltage-gated potassium channel modulation of neurotoxic activity in human immunodeficiency virus type-1(HIV-1)-infected macrophages. J Neuroimmune Pharmacol 2007; 2:265-9. [PMID: 18040860 DOI: 10.1007/s11481-007-9072-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Accepted: 03/15/2007] [Indexed: 11/30/2022]
Abstract
Macrophages play an important role in brain immune and inflammatory responses. They are also critical cells in mediating the pathology of neurodegenerative disorders such as HIV-associated dementia. This is largely through their capacity to secrete a variety of bioactive molecules such as cytokines, leading to neuronal dysfunction and/or death. Accumulating evidence indicates that voltage-gated potassium (Kv) channels play a pivotal role in the modulation of macrophage proliferation, activation, and secretion. Blockade of Kv channels by specific antagonists decreases macrophage cytokine production and ameliorates macrophage-associated neuronal injury. These results suggest that Kv channels might become a potential target for the development of new therapeutic strategies for chronic inflammatory diseases.
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Affiliation(s)
- Elizabeth Irvine
- Neurophysiology Laboratory, the Center for Neurovirology and Neurodegenerative Disorders, and Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198-5880, USA
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142
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Generation, homeostasis, and regulation of memory T cells in transplantation. Curr Opin Organ Transplant 2007; 12:23-29. [DOI: 10.1097/mot.0b013e328012b293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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143
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Azam P, Sankaranarayanan A, Homerick D, Griffey S, Wulff H. Targeting effector memory T cells with the small molecule Kv1.3 blocker PAP-1 suppresses allergic contact dermatitis. J Invest Dermatol 2007; 127:1419-29. [PMID: 17273162 PMCID: PMC1929164 DOI: 10.1038/sj.jid.5700717] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The voltage-gated potassium channel Kv1.3 has been recently identified as a molecular target that allows for selective pharmacological suppression of effector memory T (T(EM)) cells without affecting the function of naïve and central memory T cells. We here investigated whether PAP-1, a small molecule Kv1.3 blocker (EC50=2 nM), could suppress allergic contact dermatitis (ACD). In a rat model of ACD, we first confirmed that the infiltrating cells in the elicitation phase are indeed CD8+ CD45RC- memory T cells with high Kv1.3 expression. In accordance with its selective effect on T(EM) cells, PAP-1 did not impair sensitization, but potently suppressed oxazolone-induced inflammation by inhibiting the infiltration of CD8+ T cells and reducing the production of the inflammatory cytokines IFN-gamma, IL-2, and IL-17 when administered intraperitoneally or orally during the elicitation phase. PAP-1 was equally effective when applied topically, demonstrating that it effectively penetrates skin. We further show that PAP-1 is not a sensitizer or an irritant and exhibits no toxicity in a 28-day toxicity study. Based on these results we propose that PAP-1 could potentially be developed into a drug for the topical treatment of inflammatory skin diseases such as psoriasis.
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Affiliation(s)
- Philippe Azam
- Department of Medical Pharmacology and Toxicology, University of California, Davis, California, USA
| | | | - Daniel Homerick
- Department of Medical Pharmacology and Toxicology, University of California, Davis, California, USA
| | - Stephen Griffey
- Comparative Pathology Laboratory University of California, Davis, California, USA
| | - Heike Wulff
- Department of Medical Pharmacology and Toxicology, University of California, Davis, California, USA
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144
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Liu GZ, Fang LB, Hjelmström P, Gao XG. Increased CD8+ central memory T cells in patients with multiple sclerosis. Mult Scler 2007; 13:149-55. [PMID: 17439879 DOI: 10.1177/1352458506069246] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A T-cell-mediated autoimmune process against central nervous system myelin is believed to underlie the pathogenesis of multiple sclerosis (MS). Formation of immunological memory is based on the differentiation of naïve T cells to memory T cells after exposure to antigens and specific cytokines. The aim of this study was to analyse peripheral blood mononuclear cells in patients with MS for different T-cell subsets including naïve and memory T cells. Flow cytometry and enzyme-linked immunosorbent assay were used to analyse memory T-cell subsets and plasma concentration of interleukin-15 (IL-15) in peripheral blood of MS patients, patients with other neurological disorders and healthy controls. MS patients had a skewed distribution of T cells with an increased level of CD8+/CCR7+/CD45RA - central memory T cells (TCM) compared to healthy controls. In addition, MS patients showed significantly higher levels of plasma IL-15 than healthy controls did. Upregulated CD8+ TCM in MS patients may reflect a persistent chronic inflammatory response that may have been induced during early stages of the disease. This derangement may be important for maintaining chronic inflammation in MS.
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Affiliation(s)
- Guang-Zhi Liu
- Department of Neurology, Peking University People's Hospital, Beijing, PR China.
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145
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Villalonga N, Escalada A, Vicente R, Sánchez-Tilló E, Celada A, Solsona C, Felipe A. Kv1.3/Kv1.5 heteromeric channels compromise pharmacological responses in macrophages. Biochem Biophys Res Commun 2007; 352:913-8. [PMID: 17157812 DOI: 10.1016/j.bbrc.2006.11.120] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Accepted: 11/21/2006] [Indexed: 12/31/2022]
Abstract
Voltage-dependent K(+) (Kv) channels are involved in the immune response. Kv1.3 is highly expressed in activated macrophages and T-effector memory cells of autoimmune disease patients. Macrophages are actively involved in T-cell activation by cytokine production and antigen presentation. However, unlike T-cells, macrophages express Kv1.5, which is resistant to Kv1.3-drugs. We demonstrate that mononuclear phagocytes express different Kv1.3/Kv1.5 ratios, leading to biophysically and pharmacologically distinct channels. Therefore, Kv1.3-based treatments to alter physiological responses, such as proliferation and activation, are impaired by Kv1.5 expression. The presence of Kv1.5 in the macrophagic lineage should be taken into account when designing Kv1.3-based therapies.
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Affiliation(s)
- Núria Villalonga
- Molecular Physiology Laboratory, Departament de Bioquímica i Biologia Molecular, Universitat de Barcelona, Avda. Diagonal 645, E-08028 Barcelona, Spain
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146
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Beeton C, Wulff H, Standifer NE, Azam P, Mullen KM, Pennington MW, Kolski-Andreaco A, Wei E, Grino A, Counts DR, Wang PH, LeeHealey CJ, S. Andrews B, Sankaranarayanan A, Homerick D, Roeck WW, Tehranzadeh J, Stanhope KL, Zimin P, Havel PJ, Griffey S, Knaus HG, Nepom GT, Gutman GA, Calabresi PA, Chandy KG. Kv1.3 channels are a therapeutic target for T cell-mediated autoimmune diseases. Proc Natl Acad Sci U S A 2006; 103:17414-9. [PMID: 17088564 PMCID: PMC1859943 DOI: 10.1073/pnas.0605136103] [Citation(s) in RCA: 424] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Indexed: 12/25/2022] Open
Abstract
Autoreactive memory T lymphocytes are implicated in the pathogenesis of autoimmune diseases. Here we demonstrate that disease-associated autoreactive T cells from patients with type-1 diabetes mellitus or rheumatoid arthritis (RA) are mainly CD4+ CCR7- CD45RA- effector memory T cells (T(EM) cells) with elevated Kv1.3 potassium channel expression. In contrast, T cells with other antigen specificities from these patients, or autoreactive T cells from healthy individuals and disease controls, express low levels of Kv1.3 and are predominantly naïve or central-memory (T(CM)) cells. In T(EM) cells, Kv1.3 traffics to the immunological synapse during antigen presentation where it colocalizes with Kvbeta2, SAP97, ZIP, p56(lck), and CD4. Although Kv1.3 inhibitors [ShK(L5)-amide (SL5) and PAP1] do not prevent immunological synapse formation, they suppress Ca2+-signaling, cytokine production, and proliferation of autoantigen-specific T(EM) cells at pharmacologically relevant concentrations while sparing other classes of T cells. Kv1.3 inhibitors ameliorate pristane-induced arthritis in rats and reduce the incidence of experimental autoimmune diabetes in diabetes-prone (DP-BB/W) rats. Repeated dosing with Kv1.3 inhibitors in rats has not revealed systemic toxicity. Further development of Kv1.3 blockers for autoimmune disease therapy is warranted.
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MESH Headings
- Animals
- Arthritis, Rheumatoid/drug therapy
- Arthritis, Rheumatoid/immunology
- Arthritis, Rheumatoid/metabolism
- Arthritis, Rheumatoid/pathology
- Diabetes Mellitus, Type 1/drug therapy
- Diabetes Mellitus, Type 1/immunology
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/pathology
- Disease Models, Animal
- Electrophysiology
- Female
- Humans
- Kv1.3 Potassium Channel/antagonists & inhibitors
- Kv1.3 Potassium Channel/metabolism
- Pancreatitis-Associated Proteins
- Patch-Clamp Techniques
- Potassium Channel Blockers/pharmacology
- Rats
- Receptors, CCR7
- Receptors, Chemokine/metabolism
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- T-Lymphocytes/pathology
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Affiliation(s)
- Christine Beeton
- *Departments of Physiology and Biophysics, Microbiology and Molecular Genetics, Medicine, and Radiological Sciences, University of California, Irvine, CA 92697
| | - Heike Wulff
- Department of Medical Pharmacology and Toxicology, Department of Nutrition, and Comparative Pathology Laboratory, University of California, Davis, CA 95616
| | | | - Philippe Azam
- Department of Medical Pharmacology and Toxicology, Department of Nutrition, and Comparative Pathology Laboratory, University of California, Davis, CA 95616
| | | | | | - Aaron Kolski-Andreaco
- *Departments of Physiology and Biophysics, Microbiology and Molecular Genetics, Medicine, and Radiological Sciences, University of California, Irvine, CA 92697
| | - Eric Wei
- *Departments of Physiology and Biophysics, Microbiology and Molecular Genetics, Medicine, and Radiological Sciences, University of California, Irvine, CA 92697
| | - Alexandra Grino
- *Departments of Physiology and Biophysics, Microbiology and Molecular Genetics, Medicine, and Radiological Sciences, University of California, Irvine, CA 92697
| | - Debra R. Counts
- Department of Pediatrics, University of Maryland, Baltimore, MD 21201; and
| | - Ping H. Wang
- *Departments of Physiology and Biophysics, Microbiology and Molecular Genetics, Medicine, and Radiological Sciences, University of California, Irvine, CA 92697
| | - Christine J. LeeHealey
- *Departments of Physiology and Biophysics, Microbiology and Molecular Genetics, Medicine, and Radiological Sciences, University of California, Irvine, CA 92697
| | - Brian S. Andrews
- *Departments of Physiology and Biophysics, Microbiology and Molecular Genetics, Medicine, and Radiological Sciences, University of California, Irvine, CA 92697
| | - Ananthakrishnan Sankaranarayanan
- Department of Medical Pharmacology and Toxicology, Department of Nutrition, and Comparative Pathology Laboratory, University of California, Davis, CA 95616
| | - Daniel Homerick
- Department of Medical Pharmacology and Toxicology, Department of Nutrition, and Comparative Pathology Laboratory, University of California, Davis, CA 95616
| | - Werner W. Roeck
- *Departments of Physiology and Biophysics, Microbiology and Molecular Genetics, Medicine, and Radiological Sciences, University of California, Irvine, CA 92697
| | - Jamshid Tehranzadeh
- *Departments of Physiology and Biophysics, Microbiology and Molecular Genetics, Medicine, and Radiological Sciences, University of California, Irvine, CA 92697
| | - Kimber L. Stanhope
- Department of Medical Pharmacology and Toxicology, Department of Nutrition, and Comparative Pathology Laboratory, University of California, Davis, CA 95616
| | - Pavel Zimin
- Department of Medical Pharmacology and Toxicology, Department of Nutrition, and Comparative Pathology Laboratory, University of California, Davis, CA 95616
| | - Peter J. Havel
- Department of Medical Pharmacology and Toxicology, Department of Nutrition, and Comparative Pathology Laboratory, University of California, Davis, CA 95616
| | - Stephen Griffey
- Department of Medical Pharmacology and Toxicology, Department of Nutrition, and Comparative Pathology Laboratory, University of California, Davis, CA 95616
| | - Hans-Guenther Knaus
- **Division for Molecular and Cellular Pharmacology, Innsbruck Medical University, 6020 Innsbruck, Austria
| | - Gerald T. Nepom
- Benaroya Research Institute at Virginia Mason, Seattle, WA 98101
| | - George A. Gutman
- *Departments of Physiology and Biophysics, Microbiology and Molecular Genetics, Medicine, and Radiological Sciences, University of California, Irvine, CA 92697
| | | | - K. George Chandy
- *Departments of Physiology and Biophysics, Microbiology and Molecular Genetics, Medicine, and Radiological Sciences, University of California, Irvine, CA 92697
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147
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Beraud E, Viola A, Regaya I, Confort-Gouny S, Siaud P, Ibarrola D, Le Fur Y, Barbaria J, Pellissier JF, Sabatier JM, Medina I, Cozzone PJ. Block of neural Kv1.1 potassium channels for neuroinflammatory disease therapy. Ann Neurol 2006; 60:586-596. [PMID: 17044011 DOI: 10.1002/ana.21007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE We asked whether blockade of voltage-gated K+ channel Kv1.1, whose altered axonal localization during myelin insult and remyelination may disturb nerve conduction, treats experimental autoimmune encephalomyelitis (EAE). METHODS Electrophysiological, cell proliferation, cytokine secretion, immunohistochemical, clinical, brain magnetic resonance imaging, and spectroscopy studies assessed the effects of a selective blocker of Kv1.1, BgK-F6A, on neurons and immune cells in vitro and on EAE-induced neurological deficits and brain lesions in Lewis rats. RESULTS BgK-F6A increased the frequency of miniature excitatory postsynaptic currents in neurons and did not affect T-cell activation. EAE was characterized by ventriculomegaly, decreased apparent diffusion coefficient, and decreased (phosphocreatine + beta-adenosine triphosphate)/inorganic phosphate ratio. Reduced apparent diffusion coefficient and impaired energy metabolism indicate astrocytic edema. Intracerebroventricularly BgK-F6A-treated rats showed attenuated clinical EAE with unexpectedly reduced ventriculomegaly and preserved apparent diffusion coefficient values and (phosphocreatine + beta-adenosine triphosphate)/inorganic phosphate ratio. Thus, under BgK-F6A treatment, brain damage was dramatically reduced and energy metabolism maintained. INTERPRETATION Kv1.1 blockade may target neurons and astrocytes, and modulate neuronal activity and neural cell volume, which may partly account for the attenuation of the neurological deficits. We propose that Kv1.1 blockade has a broad therapeutic potential in neuroinflammatory diseases (multiple sclerosis, stroke, and trauma).
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Affiliation(s)
- Evelyne Beraud
- Service d'Immunologie, Faculté de Médecine, Université de la Méditerranée, Marseille, France.
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148
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Ndejembi MP, Tang AL, Farber DL. Reshaping the past: Strategies for modulating T-cell memory immune responses. Clin Immunol 2006; 122:1-12. [PMID: 16916619 DOI: 10.1016/j.clim.2006.06.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Accepted: 06/26/2006] [Indexed: 02/08/2023]
Abstract
Memory T cells are generated following an initial encounter with antigen, persist over the lifetime of an individual, and mediate rapid and robust functional responses upon antigenic recall. While immune memory is generally associated with protective immune response to pathogens, memory T cells can be generated to diverse types of antigens including autoantigens and alloantigens through homologous or crossreactive priming and comprise the majority of circulating T cells during adulthood. Memory T cells can therefore play critical roles in propagating and perpetuating autoimmune disease and in mediating allograft rejection, although the precise pathways for regulation of memory immune responses remain largely undefined. Moreover, evaluating and designing strategies to modulate memory T-cell responses are challenging given the remarkable heterogeneity of memory T cells, with different subsets predominating in lymphoid versus non-lymphoid tissue sites. In this review, we discuss what is presently known regarding the effect of current immunomodulation strategies on the memory T-cell compartment and potential strategies for controlling immunological recall.
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Affiliation(s)
- Modesta P Ndejembi
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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149
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Mullen KM, Rozycka M, Rus H, Hu L, Cudrici C, Zafranskaia E, Pennington MW, Johns DC, Judge SIV, Calabresi PA. Potassium channels Kv1.3 and Kv1.5 are expressed on blood-derived dendritic cells in the central nervous system. Ann Neurol 2006; 60:118-27. [PMID: 16729292 DOI: 10.1002/ana.20884] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Potassium (K(+)) channels on immune cells have gained attention recently as promising targets of therapy for immune-mediated neurological diseases such as multiple sclerosis (MS). We examined K(+) channels on dendritic cells (DCs), which infiltrate the brain in MS and may impact disease course. METHODS We identified K(+) channels on blood-derived DCs by whole-cell patch-clamp analysis, confirmed by immunofluorescent staining. We also stained K(+) channels in brain sections from MS patients and control subjects. To test functionality, we blocked K(v)1.3 and K(v)1.5 in stimulated DCs with pharmacological blockers or with an inducible dominant-negative K(v)1.x adenovirus construct and analyzed changes in costimulatory molecule upregulation. RESULTS Electrophysiological analysis of DCs showed an inward-rectifying K(+) current early after stimulation, replaced by a mix of voltage-gated K(v)1.3- and K(v)1.5-like channels at later stages of maturation. K(v)1.3 and K(v)1.5 were also highly expressed on DCs infiltrating MS brain tissue. Of note, we found that CD83, CD80, CD86, CD40, and interleukin-12 upregulation were significantly impaired on K(v)1.3 and K(v)1.5 blockade. INTERPRETATION These data support a functional role of K(v)1.5 and K(v)1.3 on activated human DCs and further define the mechanisms by which K(+) channel blockade may act to suppress immune-mediated neurological diseases.
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Affiliation(s)
- Katherine M Mullen
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21287, USA
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150
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Judge SIV, Bever CT. Potassium channel blockers in multiple sclerosis: Neuronal Kv channels and effects of symptomatic treatment. Pharmacol Ther 2006; 111:224-59. [PMID: 16472864 DOI: 10.1016/j.pharmthera.2005.10.006] [Citation(s) in RCA: 200] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2005] [Accepted: 10/12/2005] [Indexed: 02/07/2023]
Abstract
Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS) characterized by demyelination, with a relative sparing of axons. In MS patients, many neurologic signs and symptoms have been attributed to the underlying conduction deficits. The idea that neurologic function might be improved if conduction could be restored in CNS demyelinated axons led to the testing of potassium (K(+)) channel blockers as a symptomatic treatment. To date, only 2 broad-spectrum K(+) channel blockers, 4-aminopyridine (4-AP) and 3,4-diaminopyridine (3,4-DAP), have been tested in MS patients. Although both 4-AP and 3,4-DAP produce clear neurologic benefits, their use has been limited by toxicity. Here we review the current status of basic science and clinical research related to the therapeutic targeting of voltage-gated K(+) channels (K(v)) in MS. By bringing together 3 distinct but interrelated disciplines, we aim to provide perspective on a vast body of work highlighting the lengthy and ongoing process entailed in translating fundamental K(v) channel knowledge into new clinical treatments for patients with MS and other demyelinating diseases. Covered are (1) K(v) channel nomenclature, structure, function, and pharmacology; (2) classic and current experimental morphology and neurophysiology studies of demyelination and conduction deficits; and (3) a comprehensive overview of clinical trials utilizing 4-AP and 3,4-DAP in MS patients.
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Affiliation(s)
- Susan I V Judge
- MS Center of Excellence-East, Research and Neurology Services, VA Maryland Health Care System, USA.
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