Skip to main content
SpringerLink
Log in

Microglial SK3 and SK4 Currents and Activation State are Modulated by the Neuroprotective Drug, Riluzole

  • ORIGINAL ARTICLE
  • Published:
Journal of Neuroimmune Pharmacology Aims and scope Submit manuscript

Abstract

Microglia monitor the CNS for ‘danger’ signals after acute injury, such as stroke and trauma, and then undergo complex activation processes. Classical activation of microglia can produce neurotoxic levels of glutamate and immune mediators (e.g., pro-inflammatory cytokines, reactive oxygen and nitrogen species), while alternative activation up-regulates anti-inflammatory molecules and is thought to resolve inflammation and protect the brain. Thus, pharmacological strategies to decrease classical- and/or promote alternative activation are of interest. Here, we assessed actions of the neuroprotective drug, riluzole, on two Ca2+-activated K+ channels in microglia — SK3 (KCa2.3, KCNN3) and SK4 (KCa3.1, KCNN4) — and on classical versus alternative microglial activation. Riluzole is used to treat amyotrophic lateral sclerosis, and is in clinical trials for several other CNS disorders, where it has been presumed to target neurons and reduce glutamate-mediated toxicity. We show that simply elevating intracellular Ca2+ to micromolar levels in whole-cell recordings does not activate SK channels in a cell line derived from primary rat microglia (MLS-9). In intact cells, riluzole raised cytoplasmic Ca2+, but it was marginal (~200 nM) and transient (2 min). Surprisingly then, in whole cell recordings, riluzole rapidly activated SK3 and SK4 channels for as long as it was present, and did not require elevated intracellular Ca2+. We then used primary rat microglia to analyze expression of several activation markers and inflammatory mediators. Riluzole decreased classical LPS-induced activation, and increased some aspects of IL-4-induced alternative activation. These actions on microglia suggest an additional mechanism underlying the neuroprotective actions of riluzole.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3

Similar content being viewed by others

References

  • Bellingham MC (2011) A review of the neural mechanisms of action and clinical efficiency of riluzole in treating amyotrophic lateral sclerosis: what have we learned in the last decade? CNS Neurosci Ther 17(1):4–31

    Article  PubMed  CAS  Google Scholar 

  • Bensimon G, Ludolph A, Agid Y, Vidailhet M, Payan C, Leigh PN (2009) Riluzole treatment, survival and diagnostic criteria in Parkinson plus disorders: the NNIPPS study. Brain 132(Pt 1):156–171

    PubMed  Google Scholar 

  • Benton DC, Monaghan AS, Hosseini R, Bahia PK, Haylett DG, Moss GW (2003) Small conductance Ca2+-activated K+ channels formed by the expression of rat SK1 and SK2 genes in HEK 293 cells. J Physiol 553(Pt 1):13–19

    Article  PubMed  CAS  Google Scholar 

  • Block ML, Zecca L, Hong JS (2007) Microglia-mediated neurotoxicity: uncovering the molecular mechanisms. Nat Rev 8(1):57–69

    Article  CAS  Google Scholar 

  • Bouhy D, Ghasemlou N, Lively S, Redensek A, Rathore KI, Schlichter LC, David S (2011) Inhibition of the Ca2+-dependent K+ channel, KCNN4/KCa3.1, improves tissue protection and locomotor recovery after spinal cord injury. J Neurosci 31(45):16298–16308

    Article  PubMed  CAS  Google Scholar 

  • Cao YJ, Dreixler JC, Couey JJ, Houamed KM (2002) Modulation of recombinant and native neuronal SK channels by the neuroprotective drug riluzole. Eur J Pharmacol 449(1–2):47–54

    Article  PubMed  CAS  Google Scholar 

  • Cayabyab FS, Khanna R, Jones OT, Schlichter LC (2000) Suppression of the rat microglia Kv1.3 current by src-family tyrosine kinases and oxygen/glucose deprivation. Eur J Neurosci 12(6):1949–1960

    Article  PubMed  CAS  Google Scholar 

  • Cheah BC, Vucic S, Krishnan AV, Kiernan MC (2010) Riluzole, neuroprotection and amyotrophic lateral sclerosis. Curr Med Chem 17(18):1942–1959

    Article  PubMed  CAS  Google Scholar 

  • Chen YJ, Raman G, Bodendiek S, O’Donnell ME, Wulff H (2011) The KCa3.1 blocker TRAM-34 reduces infarction and neurological deficit in a rat model of ischemia/reperfusion stroke. J Cereb Blood Flow Metab

  • Colton CA (2009) Heterogeneity of microglial activation in the innate immune response in the brain. J Neuroimm Pharmacol 4(4):399–418

    Article  Google Scholar 

  • Colton CA, Mott RT, Sharpe H, Xu Q, Van Nostrand WE, Vitek MP (2006) Expression profiles for macrophage alternative activation genes in AD and in mouse models of AD. J Neuroinflamm 3:27

    Article  Google Scholar 

  • D’Hoedt D, Hirzel K, Pedarzani P, Stocker M (2004) Domain analysis of the calcium-activated potassium channel SK1 from rat brain. Functional expression and toxin sensitivity. J Biol Chem 279(13):12088–12092

    Article  PubMed  Google Scholar 

  • Downen M, Amaral TD, Hua LL, Zhao ML, Lee SC (1999) Neuronal death in cytokine-activated primary human brain cell culture: role of tumor necrosis factor-alpha. Glia 28(2):114–127

    Article  PubMed  CAS  Google Scholar 

  • Ducharme G, Newell EW, Pinto C, Schlichter LC (2007) Small-conductance Cl- channels contribute to volume regulation and phagocytosis in microglia. Eur J Neurosci 26(8):2119–2130

    Article  PubMed  Google Scholar 

  • Eder C (2010) Ion channels in monocytes and microglia/brain macrophages: promising therapeutic targets for neurological diseases. J Neuroimmunol 224(1–2):51–55

    Article  PubMed  CAS  Google Scholar 

  • Ehrlich LC, Peterson PK, Hu S (1999) Interleukin (IL)-1beta-mediated apoptosis of human astrocytes. Neuroreport 10(9):1849–1852

    Article  PubMed  CAS  Google Scholar 

  • Fanger CM, Neben AL, Cahalan MD (2000) Differential Ca2+ influx, KCa channel activity, and Ca2+ clearance distinguish Th1 and Th2 lymphocytes. J Immunol 164(3):1153–1160

    PubMed  CAS  Google Scholar 

  • Figiel I (2008) Pro-inflammatory cytokine TNF-alpha as a neuroprotective agent in the brain. Acta Neurobiol Exp 68(4):526–534

    Google Scholar 

  • Fontaine V, Mohand-Said S, Hanoteau N, Fuchs C, Pfizenmaier K, Eisel U (2002) Neurodegenerative and neuroprotective effects of tumor Necrosis factor (TNF) in retinal ischemia: opposite roles of TNF receptor 1 and TNF receptor 2. J Neurosci 22(7):RC216

    PubMed  Google Scholar 

  • Fordyce CB, Jagasia R, Zhu X, Schlichter LC (2005) Microglia Kv1.3 channels contribute to their ability to kill neurons. J Neurosci 25(31):7139–7149

    Article  PubMed  CAS  Google Scholar 

  • Fumagalli E, Bigini P, Barbera S, De Paola M, Mennini T (2006) Riluzole, unlike the AMPA antagonist RPR119990, reduces motor impairment and partially prevents motoneuron death in the wobbler mouse, a model of neurodegenerative disease. Exp Neurol 198(1):114–128

    Article  PubMed  CAS  Google Scholar 

  • Ghosh A, Carnahan J, Greenberg ME (1994) Requirement for BDNF in activity-dependent survival of cortical neurons. Science 263(5153):1618–1623

    Article  PubMed  CAS  Google Scholar 

  • Gordon S (2003) Alternative activation of macrophages. Nat Rev Immunol 3(1):23–35

    Article  PubMed  CAS  Google Scholar 

  • Gordon S, Martinez FO (2010) Alternative activation of macrophages: mechanism and functions. Immunity 32(5):593–604

    Article  PubMed  CAS  Google Scholar 

  • Grunnet M, Jespersen T, Angelo K, Frokjaer-Jensen C, Klaerke DA, Olesen SP, Jensen BS (2001) Pharmacological modulation of SK3 channels. Neuropharmacology 40(7):879–887

    Article  PubMed  CAS  Google Scholar 

  • Grynkiewicz G, Poenie M, Tsien RY (1985) A new generation of Ca2+ indicators with greatly improved fluorescence properties. J Biol Chem 260(6):3440–3450

    PubMed  CAS  Google Scholar 

  • Hailer NP (2008) Immunosuppression after traumatic or ischemic CNS damage: it is neuroprotective and illuminates the role of microglial cells. Prog Neurobiol 84(3):211–233

    Article  PubMed  CAS  Google Scholar 

  • He BP, Wen W, Strong MJ (2002) Activated microglia (BV-2) facilitation of TNF-alpha-mediated motor neuron death in vitro. J Neuroimmunol 128(1–2):31–38

    Article  PubMed  CAS  Google Scholar 

  • Hung SI, Chang AC, Kato I, Chang NC (2002) Transient expression of Ym1, a heparin-binding lectin, during developmental hematopoiesis and inflammation. J Leuk Biol 72(1):72–82

    CAS  Google Scholar 

  • Jensen BS, Strobaek D, Olesen SP, Christophersen P (2001) The Ca2+-activated K+ channel of intermediate conductance: a molecular target for novel treatments? Curr Drug Targets 2(4):401–422

    Article  PubMed  CAS  Google Scholar 

  • Jiang X, Newell EW, Schlichter LC (2003) Regulation of a TRPM7-like current in rat brain microglia. J Biol Chem 278(44):42867–42876

    Article  PubMed  CAS  Google Scholar 

  • Katoh-Semba R, Asano T, Ueda H, Morishita R, Takeuchi IK, Inaguma Y, Kato K (2002) Riluzole enhances expression of brain-derived neurotrophic factor with consequent proliferation of granule precursor cells in the rat hippocampus. Faseb J 16(10):1328–1330

    PubMed  CAS  Google Scholar 

  • Kaushal V, Schlichter LC (2008) Mechanisms of microglia-mediated neurotoxicity in a new model of the stroke penumbra. J Neurosci 28(9):2221–2230

    Article  PubMed  CAS  Google Scholar 

  • Kaushal V, Koeberle PD, Wang Y, Schlichter LC (2007) The Ca2+-activated K+ channel KCNN4/KCa3.1 contributes to microglia activation and nitric oxide-dependent neurodegeneration. J Neurosci 27(1):234–244

    Article  PubMed  CAS  Google Scholar 

  • Kettenmann H, Hanisch UK, Noda M, Verkhratsky A (2011) Physiology of microglia. Physiol Rev 91(2):461–553

    Article  PubMed  CAS  Google Scholar 

  • Khanna R, Chang MC, Joiner WJ, Kaczmarek LK, Schlichter LC (1999) hSK4/hIK1, a calmodulin-binding KCa channel in human T lymphocytes. Roles in proliferation and volume regulation. J Biol Chem 274(21):14838–14849

    Article  PubMed  CAS  Google Scholar 

  • Khanna R, Roy L, Zhu X, Schlichter LC (2001) K+ channels and the microglial respiratory burst. Am J Physiol 280(4):C796–C806

    CAS  Google Scholar 

  • Landwehrmeyer GB, Dubois B, de Yebenes JG, Kremer B, Gaus W, Kraus PH, Przuntek H, Dib M, Doble A, Fischer W, Ludolph AC (2007) Riluzole in Huntington’s disease: a 3-year, randomized controlled study. Ann Neurol 62(3):262–272

    Article  PubMed  CAS  Google Scholar 

  • Martinez FO, Helming L, Gordon S (2009) Alternative activation of macrophages: an immunologic functional perspective. Ann Rev Immunol 27:451–483

    Article  CAS  Google Scholar 

  • Meininger V, Lacomblez L, Salachas F (2000) What has changed with riluzole? J Neurol 247:19–22

    Article  PubMed  CAS  Google Scholar 

  • Monaghan AS, Benton DC, Bahia PK, Hosseini R, Shah YA, Haylett DG, Moss GW (2004) The SK3 subunit of small conductance Ca2+-activated K+ channels interacts with both SK1 and SK2 subunits in a heterologous expression system. J Biol Chem 279(2):1003–1009

    Article  PubMed  CAS  Google Scholar 

  • Nakazawa T, Kayama M, Ryu M, Kunikata H, Watanabe R, Yasuda M, Kinugawa J, Vavvas D, Miller JW (2011) Tumor necrosis factor-alpha mediates photoreceptor death in a rodent model of retinal detachment. Invest Ophthalmol Vis Sci 52(3):1384–1391

    Article  PubMed  CAS  Google Scholar 

  • Newell EW, Schlichter LC (2005) Integration of K+ and Cl- currents regulate steady-state and dynamic membrane potentials in cultured rat microglia. J Physiol 567(Pt 3):869–890

    Article  PubMed  CAS  Google Scholar 

  • Ohana L, Newell EW, Stanley EF, Schlichter LC (2009) The Ca2+ release-activated Ca2+ current (I(CRAC)) mediates store-operated Ca2+ entry in rat microglia. Channels (Austin, Tex 3(2):129–139

    Google Scholar 

  • Pedarzani P, Stocker M (2008) Molecular and cellular basis of small–and intermediate-conductance, calcium-activated potassium channel function in the brain. Cell Mol Life Sci 65(20):3196–3217

    Article  PubMed  CAS  Google Scholar 

  • Ransohoff RM, Perry VH (2009) Microglial physiology: unique stimuli, specialized responses. Ann Rev Immunol 27:119–145

    Article  CAS  Google Scholar 

  • Sailer CA, Hu H, Kaufmann WA, Trieb M, Schwarzer C, Storm JF, Knaus HG (2002) Regional differences in distribution and functional expression of small-conductance Ca2+-activated K+ channels in rat brain. J Neurosci 22(22):9698–9707

    PubMed  CAS  Google Scholar 

  • Sankaranarayanan A, Raman G, Busch C, Schultz T, Zimin PI, Hoyer J, Kohler R, Wulff H (2009) Naphtho[1,2-d]thiazol-2-ylamine (SKA-31), a new activator of KCa2 and KCa3.1 potassium channels, potentiates the endothelium-derived hyperpolarizing factor response and lowers blood pressure. Mol Pharmacol 75(2):281–295

    Article  PubMed  CAS  Google Scholar 

  • Schilling T, Stock C, Schwab A, Eder C (2004) Functional importance of Ca2+-activated K+ channels for lysophosphatidic acid-induced microglial migration. Eur J Neurosci 19(6):1469–1474

    Article  PubMed  Google Scholar 

  • Schlichter LC, Sakellaropoulos G, Ballyk B, Pennefather PS, Phipps DJ (1996) Properties of K+ and Cl- channels and their involvement in proliferation of rat microglial cells. Glia 17(3):225–236

    Article  PubMed  CAS  Google Scholar 

  • Schlichter LC, Kaushal V, Moxon-Emre I, Sivagnanam V, Vincent C (2010) The Ca2+ activated SK3 channel is expressed in microglia in the rat striatum and contributes to microglia-mediated neurotoxicity in vitro. J Neuroinflamm 7:4

    Article  Google Scholar 

  • Schlichter LC, Mertens T, Liu B (2011) Swelling activated Cl- channels in microglia: Biophysics, pharmacology and role in glutamate release. Channels (Austin, Tex 5 (2):128–137

    Google Scholar 

  • Sivagnanam V, Zhu X, Schlichter LC (2010) Dominance of E. coli phagocytosis over LPS in the inflammatory response of microglia. J Neuroimmunol 227(1–2):111–119

    Article  PubMed  CAS  Google Scholar 

  • Skaper SD (2010) Ion channels on microglia: therapeutic targets for neuroprotection. CNS Neurol Disorders Drug Targets 10(1):44–56

    Article  Google Scholar 

  • Takahashi JL, Giuliani F, Power C, Imai Y, Yong VW (2003) Interleukin-1beta promotes oligodendrocyte death through glutamate excitotoxicity. Ann Neurol 53(5):588–595

    Article  PubMed  CAS  Google Scholar 

  • Takeuchi H, Jin S, Wang J, Zhang G, Kawanokuchi J, Kuno R, Sonobe Y, Mizuno T, Suzumura A (2006) Tumor necrosis factor-alpha induces neurotoxicity via glutamate release from hemichannels of activated microglia in an autocrine manner. J Biol Chem 281(30):21362–21368

    Article  PubMed  CAS  Google Scholar 

  • Varin A, Gordon S (2009) Alternative activation of macrophages: immune function and cellular biology. Immunobiology 214(7):630–641

    Article  PubMed  CAS  Google Scholar 

  • Venters HD, Dantzer R, Kelley KW (2000) Tumor necrosis factor-alpha induces neuronal death by silencing survival signals generated by the type I insulin-like growth factor receptor. Ann N Y Acad Sci 917:210–220

    Article  PubMed  CAS  Google Scholar 

  • Viviani B, Corsini E, Galli CL, Marinovich M (1998) Glia increase degeneration of hippocampal neurons through release of tumor necrosis factor-alpha. Toxicol Appl Pharmacol 150(2):271–276

    Article  PubMed  CAS  Google Scholar 

  • Wahl SM, Wen J, Moutsopoulos N (2006) TGF-beta: a mobile purveyor of immune privilege. Immunol Rev 213:213–227

    Article  PubMed  CAS  Google Scholar 

  • Wang XJ, Kong KM, Qi WL, Ye WL, Song PS (2005) Interleukin-1 beta induction of neuron apoptosis depends on p38 mitogen-activated protein kinase activity after spinal cord injury. Acta Pharmacol Sinica 26(8):934–942

    Article  Google Scholar 

  • Wulff H, Zhorov BS (2008) K+ channel modulators for the treatment of neurological disorders and autoimmune diseases. Chem Rev 108(5):1744–1773

    Article  PubMed  CAS  Google Scholar 

  • Xia XM, Fakler B, Rivard A, Wayman G, Johnson-Pais T, Keen JE, Ishii T, Hirschberg B, Bond CT, Lutsenko S, Maylie J, Adelman JP (1998) Mechanism of calcium gating in small-conductance calcium-activated potassium channels. Nature 395(6701):503–507

    Article  PubMed  CAS  Google Scholar 

Download references

Acknowledgments

This research was funded by a Heart and Stroke Foundation of Canada (HSF) grant to LCS (#T6766), a postdoctoral fellowship to SL from the Canadian Institutes for Health Research (CIHR), and graduate scholarships to RF from HSF and the Natural Sciences and Engineering Research Council (NSERC). We thank X-P Zhu for excellent technical assistance.

Conflict of interest

The authors declare that they have no conflict of interest.

Author information

Authors and Affiliations

  1. Toronto Western Research Institute, University Health Network, MC9-417, 399 Bathurst Street, Toronto, Ontario, M5T 2S8, Canada

    B.-S. Liu, R. Ferreira, S. Lively & L. C. Schlichter

  2. Department of Physiology, University of Toronto, Toronto, Ontario, Canada

    R. Ferreira & L. C. Schlichter

Authors
  1. B.-S. Liu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. R. Ferreira
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. S. Lively
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. L. C. Schlichter
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to L. C. Schlichter.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Liu, BS., Ferreira, R., Lively, S. et al. Microglial SK3 and SK4 Currents and Activation State are Modulated by the Neuroprotective Drug, Riluzole. J Neuroimmune Pharmacol 8, 227–237 (2013). https://doi.org/10.1007/s11481-012-9365-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11481-012-9365-0

Keywords

Search

Navigation