Abstract
In the nervous system, the intracellular chloride concentration ([Cl−]i) determines the strength and polarity of γ-aminobutyric acid (GABA)-mediated neurotransmission. [Cl−]i is determined, in part, by the activities of the SLC12 cation–chloride cotransporters (CCCs). These transporters include the Na–K–2Cl cotransporter NKCC1, which mediates chloride influx, and various K–Cl cotransporters—such as KCC2 and KCC3—that extrude chloride. A precise balance between NKCC1 and KCC2 activity is necessary for inhibitory GABAergic signaling in the adult CNS, and for excitatory GABAergic signaling in the developing CNS and the adult PNS. Altered chloride homeostasis, resulting from mutation or dysfunction of NKCC1 and/or KCC2, causes neuronal hypoexcitability or hyperexcitability; such derangements have been implicated in the pathogenesis of seizures and neuropathic pain. [Cl−]i is also regulated to maintain normal cell volume. Dysfunction of NKCC1 or of swelling-activated K–Cl cotransporters has been implicated in the damaging secondary effects of cerebral edema after ischemic and traumatic brain injury, as well as in swelling-related neurodegeneration. CCCs represent attractive therapeutic targets in neurological disorders the pathogenesis of which involves deranged cellular chloride homoestasis.
Key Points
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In mammalian neurons, the strength and polarity of γ-aminobutyric acid (GABA)-mediated neurotransmission is largely determined by the intracellular chloride concentration ([Cl–]i)
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Cation–chloride cotransporters (CCCs) have important roles in determining the [Cl–]i of both neurons and glia; the Na–K–2Cl cotransporter NKCC1 transports chloride into cells, and K–Cl cotransporters, such as KCC2 and KCC3, transport chloride out of cells
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Altered [Cl–]i homeostasis resulting from mutation or dysfunction of NKCC1 and/or KCC2 can cause hypoexcitability or hyperexcitability of neurons; such derangements have been implicated in the pathogenesis of ischemic seizures, neonatal seizures, temporal lobe epilepsy and neuropathic pain
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NKCC1 and the swelling-activated K–Cl cotransporters are important regulators of cell volume
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CCCs are potential targets for novel therapeutic strategies in various neurological disorders that are characterized by deranged cellular chloride homoestasis
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The NKCC1 inhibitor bumetanide has been shown to decrease epileptiform activity in models of neonatal seizures and temporal lobe epilepsy and to decrease cerebral edema after traumatic brain injury or stroke
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References
Delpire E (2000) Cation–chloride cotransporters in neuronal communication. News Physiol Sci 15: 309–312
Payne JA et al. (2003) Cation–chloride co-transporters in neuronal communication, development and trauma. Trends Neurosci 26: 199–206
Gamba G (2005) Molecular physiology and pathophysiology of electroneutral cation–chloride cotransporters. Physiol Rev 85: 423–493
Hebert SC et al. (2004) Molecular physiology of cation-coupled Cl− cotransport: the SLC12 family. Pflugers Arch 447: 580–593
Plotkin MD et al. (1997) Expression of the Na+–K+–2Cl− cotransporter BSC2 in the nervous system. Am J Physiol 272: C173–C183
Payne JA et al. (1996) Molecular characterization of a putative K–Cl cotransporter in rat brain: a neuronal-specific isoform. J Biol Chem 271: 16245–16252
Pearson MM et al. (2001) Localization of the K+–Cl− cotransporter, KCC3, in the central and peripheral nervous systems: expression in the choroid plexus, large neurons and white matter tracts. Neuroscience 103: 481–491
Karadsheh MF et al. (2004) Localization of the KCC4 potassium–chloride cotransporter in the nervous system. Neuroscience 123: 381–391
Adragna NC et al. (2004) Regulation of K–Cl cotransport: from function to genes. J Membr Biol 201: 109–137
Flatman PW (2002) Regulation of Na–K–2Cl cotransport by phosphorylation and protein–protein interactions. Biochim Biophys Acta 1566: 140–151
Song L et al. (2002) Molecular, functional, and genomic characterization of human KCC2, the neuronal K–Cl cotransporter. Brain Res Mol Brain Res 103: 91–105
Mercado A et al. (2006) A C-terminal domain in KCC2 confers constitutive K+–Cl− cotransport. J Biol Chem 281: 1016–1026
Kahle KT et al. (2008) Molecular physiology of the WNK kinases. Annu Rev Physiol 70: 329–355
Kahle KT et al. (2006) WNK protein kinases modulate cellular Cl− flux by altering the phosphorylation state of the Na–K–Cl and K–Cl cotransporters. Physiology (Bethesda) 21: 326–335
Delpire E and Gagnon KB (2008) SPAK and OSR1: STE20 kinases involved in the regulation of ion homoeostasis and volume control in mammalian cells. Biochem J 409: 321–331
Ben-Ari Y (2001) Developing networks play a similar melody. Trends Neurosci 24: 353–360
Ben-Ari Y (2002) Excitatory actions of GABA during development: the nature of the nurture. Nat Rev Neurosci 3: 728–739
Dzhala VI and Staley KJ (2003) Excitatory actions of endogenously released GABA contribute to initiation of ictal epileptiform activity in the developing hippocampus. J Neurosci 23: 1840–1846
Wang C et al. (2002) Developmental changes in KCC1, KCC2, and NKCC1 mRNA expressions in the rat brain. Brain Res Dev Brain Res 139: 59–66
Clayton GH et al. (1998) Ontogeny of cation–Cl− cotransporter expression in rat neocortex. Brain Res Dev Brain Res 109: 281–292
Plotkin MD et al. (1997) Expression of the Na–K–2Cl cotransporter is developmentally regulated in postnatal rat brains: a possible mechanism underlying GABA's excitatory role in immature brain. J Neurobiol 33: 781–795
Ge S et al. (2006) GABA regulates synaptic integration of newly generated neurons in the adult brain. Nature 439: 589–593
Cancedda L et al. (2007) Excitatory GABA action is essential for morphological maturation of cortical neurons in vivo. J Neurosci 27: 5224–5235
Reynolds A et al. (2008) Neurogenic role of the depolarizing chloride gradient revealed by global overexpression of KCC2 from the onset of development. J Neurosci 28: 1588–1597
Stein V et al. (2004) Expression of the KCl cotransporter KCC2 parallels neuronal maturation and the emergence of low intracellular chloride. J Comp Neurol 468: 57–64
Rivera C et al. (1999) The K+/Cl− co-transporter KCC2 renders GABA hyperpolarizing during neuronal maturation. Nature 397: 251–255
Dzhala VI et al. (2005) NKCC1 transporter facilitates seizures in the developing brain. Nat Med 11: 1205–1213
Hubner CA et al. (2001) Disruption of KCC2 reveals an essential role of K–Cl cotransport already in early synaptic inhibition. Neuron 30: 515–524
Li H et al. (2007) KCC2 interacts with the dendritic cytoskeleton to promote spine development. Neuron 56: 1019–1033
Ganguly K et al. (2001) GABA itself promotes the developmental switch of neuronal GABAergic responses from excitation to inhibition. Cell 105: 521–532
Titz S et al. (2003) Hyperpolarizing inhibition develops without trophic support by GABA in cultured rat midbrain neurons. J Physiol 550: 719–730
Liu Z et al. (2006) Sequential interplay of nicotinic and GABAergic signaling guides neuronal development. Science 314: 1610–1613
Kelsch W et al. (2001) Insulin-like growth factor 1 and a cytosolic tyrosine kinase activate chloride outward transport during maturation of hippocampal neurons. J Neurosci 21: 8339–8347
Aguado F et al. (2003) BDNF regulates spontaneous correlated activity at early developmental stages by increasing synaptogenesis and expression of the K+/Cl− co-transporter KCC2. Development 130: 1267–1280
Scher MS and Painter MJ (1989) Controversies concerning neonatal seizures. Pediatr Clin North Am 36: 281–310
Lee DS et al. (1994) Myoclonus associated with lorazepam therapy in very-low-birth-weight infants. Biol Neonate 66: 311–315
Staley K (1992) Enhancement of the excitatory actions of GABA by barbiturates and benzodiazepines. Neurosci Lett 146: 105–107
Dzhala VI et al. (2008) Bumetanide enhances phenobarbital efficacy in a neonatal seizure model. Ann Neurol 63: 222–235
Scher MS et al. (2003) Uncoupling of EEG-clinical neonatal seizures after antiepileptic drug use. Pediatr Neurol 28: 277–280
Connell J et al. (1989) Clinical and EEG response to anticonvulsants in neonatal seizures. Arch Dis Child 64: 459–464
Painter MJ et al. (1999) Phenobarbital compared with phenytoin for the treatment of neonatal seizures. N Engl J Med 341: 485–489
Brumback AC and Staley KJ (2008) Thermodynamic regulation of NKCC1-mediated Cl− cotransport underlies plasticity of GABAA signaling in neonatal neurons. J Neurosci 28: 1301–1312
Jean-Xavier C et al. (2007) Dual personality of GABA/glycine-mediated depolarizations in immature spinal cord. Proc Natl Acad Sci USA 104: 11477–11482
Sullivan JE et al. (1996) Pharmacokinetics of bumetanide in critically ill infants. Clin Pharmacol Ther 60: 405–413
Cohen I et al. (2002) On the origin of interictal activity in human temporal lobe epilepsy in vitro. Science 298: 1418–1421
Hochman DW et al. (1995) Dissociation of synchronization and excitability in furosemide blockade of epileptiform activity. Science 270: 99–102
Hochman DW and Schwartzkroin PA (2000) Chloride-cotransport blockade desynchronizes neuronal discharge in the “epileptic” hippocampal slice. J Neurophysiol 83: 406–417
Haglund MM and Hochman DW (2005) Furosemide and mannitol suppression of epileptic activity in the human brain. J Neurophysiol 94: 907–918
Hesdorffer DC et al. (2001) Are certain diuretics also anticonvulsants. Ann Neurol 50: 458–462
Hekmat-Scafe DS et al. (2006) Mutations in the K+/Cl− cotransporter gene kazachoc (kcc) increase seizure susceptibility in Drosophila. J Neurosci 26: 8943–8954
Woo NS et al. (2002) Hyperexcitability and epilepsy associated with disruption of the mouse neuronal-specific K–Cl cotransporter gene. Hippocampus 12: 258–268
Huberfeld G et al. (2007) Perturbed chloride homeostasis and GABAergic signaling in human temporal lobe epilepsy. J Neurosci 27: 9866–9873
Palma E et al. (2006) Anomalous levels of Cl− transporters in the hippocampal subiculum from temporal lobe epilepsy patients make GABA excitatory. Proc Natl Acad Sci USA 103: 8465–8468
Munoz A et al. (2007) Cation–chloride cotransporters and GABA-ergic innervation in the human epileptic hippocampus. Epilepsia 48: 663–673
Pathak HR et al. (2007) Disrupted dentate granule cell chloride regulation enhances synaptic excitability during development of temporal lobe epilepsy. J Neurosci 27: 14012–14022
Sen A et al. (2007) Increased NKCC1 expression in refractory human epilepsy. Epilepsy Res 74: 220–227
Aronica E et al. (2007) Differential expression patterns of chloride transporters, Na+–K+–2Cl−-cotransporter and K+–Cl−-cotransporter, in epilepsy-associated malformations of cortical development. Neuroscience 145: 185–196
Munakata M et al. (2007) Altered distribution of KCC2 in cortical dysplasia in patients with intractable epilepsy. Epilepsia 48: 837–844
Shimizu-Okabe C et al. (2007) Changes in the expression of cation–Cl− cotransporters, NKCC1 and KCC2, during cortical malformation induced by neonatal freeze-lesion. Neurosci Res 59: 288–295
Young GB et al. (1990) The significance of myoclonic status epilepticus in postanoxic coma. Neurology 40: 1843–1848
Inglefield JR and Schwartz-Bloom RD (1998) Activation of excitatory amino acid receptors in the rat hippocampal slice increases intracellular Cl− and cell volume. J Neurochem 71: 1396–1404
Galeffi F et al. (2004) Changes in intracellular chloride after oxygen-glucose deprivation of the adult hippocampal slice: effect of diazepam. J Neurosci 24: 4478–4488
Pond BB et al. (2006) The chloride transporter Na+–K+–Cl− cotransporter isoform-1 contributes to intracellular chloride increases after in vitro ischemia. J Neurosci 26: 1396–1406
Beck J et al. (2003) Na–K–Cl cotransporter contributes to glutamate-mediated excitotoxicity. J Neurosci 23: 5061–5068
Su G et al. (2002) Astrocytes from Na+–K+–Cl− cotransporter-null mice exhibit absence of swelling and decrease in EAA release. Am J Physiol Cell Physiol 282: C1147–C1160
Su G et al. (2002) Contribution of Na+–K+–Cl− cotransporter to high-[K+]o-induced swelling and EAA release in astrocytes. Am J Physiol Cell Physiol 282: C1136–C1146
Schomberg SL et al. (2001) Stimulation of Na–K–2Cl cotransporter in neurons by activation of non-NMDA ionotropic receptor and group-I mGluRs. J Neurophysiol 85: 2563–2575
Yan Y et al. (2003) Inhibition of Na+–K+–Cl− cotransporter during focal cerebral ischemia decreases edema and neuronal damage. Brain Res 961: 22–31
Pond BB et al. (2004) Chloride transport inhibitors influence recovery from oxygen-glucose deprivation-induced cellular injury in adult hippocampus. Neuropharmacology 47: 253–262
Chen H and Sun D (2005) The role of Na–K–Cl co-transporter in cerebral ischemia. Neurol Res 27: 280–286
Nabekura J et al. (2002) Reduction of KCC2 expression and GABAA receptor-mediated excitation after in vivo axonal injury. J Neurosci 22: 4412–4417
Toyoda H et al. (2003) Induction of NMDA and GABAA receptor-mediated Ca2+ oscillations with KCC2 mRNA downregulation in injured facial motoneurons. J Neurophysiol 89: 1353–1362
Buhl EH et al. (1996) Zinc-induced collapse of augmented inhibition by GABA in a temporal lobe epilepsy model. Science 271: 369–373
Cohen I et al. (2003) Mesial temporal lobe epilepsy: a pathological replay of developmental mechanisms. Biol Cell 95: 329–333
Binder DK et al. (2001) BDNF and epilepsy: too much of a good thing. Trends Neurosci 24: 47–53
Huang EJ and Reichardt LF (2003) Trk receptors: roles in neuronal signal transduction. Annu Rev Biochem 72: 609–642
Rivera C et al. (2002) BDNF-induced TrkB activation down-regulates the K+–Cl− cotransporter KCC2 and impairs neuronal Cl− extrusion. J Cell Biol 159: 747–752
Rivera C et al. (2004) Mechanism of activity-dependent downregulation of the neuron-specific K–Cl cotransporter KCC2. J Neurosci 24: 4683–4691
Wake H et al. (2007) Early changes in KCC2 phosphorylation in response to neuronal stress result in functional downregulation. J Neurosci 27: 1642–1650
Price TJ et al. (2005) Role of cation–chloride-cotransporters (CCC) in pain and hyperalgesia. Curr Top Med Chem 5: 547–555
Coull JA et al. (2003) Trans-synaptic shift in anion gradient in spinal lamina I neurons as a mechanism of neuropathic pain. Nature 424: 938–942
Tornberg J et al. (2005) Behavioural phenotypes of hypomorphic KCC2-deficient mice. Eur J Neurosci 21: 1327–1337
Coull JA et al. (2005) BDNF from microglia causes the shift in neuronal anion gradient underlying neuropathic pain. Nature 438: 1017–1021
Nomura H et al. (2006) Expression changes of cation chloride cotransporters in the rat spinal cord following intraplantar formalin. Neurosci Res 56: 435–440
Sung KW et al. (2000) Abnormal GABAA receptor-mediated currents in dorsal root ganglion neurons isolated from Na–K–2Cl cotransporter null mice. J Neurosci 20: 7531–7538
Rohrbough J and Spitzer NC (1996) Regulation of intracellular Cl− levels by Na+-dependent Cl− cotransport distinguishes depolarizing from hyperpolarizing GABAA receptor-mediated responses in spinal neurons. J Neurosci 16: 82–91
Valeyev AY et al. (1999) GABA-induced Cl− current in cultured embryonic human dorsal root ganglion neurons. J Neurophysiol 82: 1–9
Laird JM et al. (2004) Presynaptic inhibition and spinal pain processing in mice: a possible role of the NKCC1 cation–chloride co-transporter in hyperalgesia. Neurosci Lett 361: 200–203
Morales-Aza BM et al. (2004) Inflammation alters cation chloride cotransporter expression in sensory neurons. Neurobiol Dis 17: 62–69
Galan A and Cervero F (2005) Painful stimuli induce in vivo phosphorylation and membrane mobilization of mouse spinal cord NKCC1 co-transporter. Neuroscience 133: 245–252
Lang F et al. (1998) Functional significance of cell volume regulatory mechanisms. Physiol Rev 78: 247–306
Strange K (2004) Cellular volume homeostasis. Adv Physiol Educ 28: 155–159
McManus ML and Churchwell KB (1994) Clinical significance of cellular osmoregulation. In Cellular and Molecular Physiology of Cell Volume Regulation, 63–77 (Ed Strange K) Boca Raton, FL: CRC Press
McManus ML et al. (1995) Regulation of cell volume in health and disease. N Engl J Med 333: 1260–1266
Mercado A et al. (2004) Electroneutral cation–chloride cotransporters in the central nervous system. Neurochem Res 29: 17–25
Staley KJ and and Proctor WR (1999) Modulation of mammalian dendritic GABAA receptor function by the kinetics of Cl− and HCO3− transport. J Physiol 519: 693–712
Strange K et al. (2006) Ste20-type kinases: evolutionarily conserved regulators of ion transport and cell volume. Physiology (Bethesda) 21: 61–68
Pedersen SF et al. (2006) Physiology and pathophysiology of Na+/H+ exchange and Na+–K+–2Cl− cotransport in the heart, brain, and blood. Am J Physiol Regul Integr Comp Physiol 291: R1–R25
Lenart B et al. (2004) Na–K–Cl cotransporter-mediated intracellular Na+ accumulation affects Ca2+ signaling in astrocytes in an in vitro ischemic model. J Neurosci 24: 9585–9597
Foroutan S et al. (2005) Moderate-to-severe ischemic conditions increase activity and phosphorylation of the cerebral microvascular endothelial cell Na+–K+–Cl− cotransporter. Am J Physiol Cell Physiol 289: C1492–C1501
Sun D et al. (1997) IL-6 secreted by astroglial cells regulates Na–K–Cl cotransport in brain microvessel endothelial cells. Am J Physiol 272: C1829–C1835
Zawadzka M and Kaminska B (2005) A novel mechanism of FK506-mediated neuroprotection: downregulation of cytokine expression in glial cells. Glia 49: 36–51
O'Donnell ME et al. (2004) Bumetanide inhibition of the blood-brain barrier Na–K–Cl cotransporter reduces edema formation in the rat middle cerebral artery occlusion model of stroke. J Cereb Blood Flow Metab 24: 1046–1056
Tran L et al. (2005) Reduction of cerebral edema by bumetanide administered after initiation of permanent middle cerebral artery occlusion [abstract]. FASEB J 19: A808
Tran LQ et al. (2004) HOE-642 and bumetanide reduce edema formation and infarct following permanent rat middle cerebral artery occlusion [abstract]. FASEB J 18: A1069
Thomas R et al. (2004) Acute ischemic injury of astrocytes is mediated by Na–K–Cl cotransport and not Ca2+ influx at a key point in white matter development. J Neuropathol Exp Neurol 63: 856–871
Rutledge EM et al. (1998) Pharmacological characterization of swelling-induced D-[3H]aspartate release from primary astrocyte cultures. Am J Physiol 274: C1511–C1520
O'Neill WC (1999) Physiological significance of volume-regulatory transporters. Am J Physiol 276: C995–C1011
Race JE et al. (1999) Molecular cloning and functional characterization of KCC3, a new K-Cl cotransporter. Am J Physiol 277: C1210–C1219
Boettger T et al. (2003) Loss of K–Cl co-transporter KCC3 causes deafness, neurodegeneration and reduced seizure threshold. EMBO J 22: 5422–5434
Byun N and Delpire E (2007) Axonal and periaxonal swelling precede peripheral neurodegeneration in KCC3 knockout mice. Neurobiol Dis 28: 39–51
Howard HC et al. (2002) The K–Cl cotransporter KCC3 is mutant in a severe peripheral neuropathy associated with agenesis of the corpus callosum. Nat Genet 32: 384–392
Citizens United for Research in Epilepsy: Current Grant Recipients [http://www.cureepilepsy.org/research/current.asp]
Maa E et al. (2007) Oral bumetanide add-on therapy in refractory temporal lobe epilepsy [abstract #3.222]. Epilepsia 48: S6
van der Vorst MM et al. (2006) Diuretics in pediatrics: current knowledge and future prospects. Paediatr Drugs 8: 245–264
Lopez-Samblas AM et al. (1997) The pharmacokinetics of bumetanide in the newborn infant. Biol Neonate 72: 265–272
Bittigau P et al. (2003) Antiepileptic drugs and apoptosis in the developing brain. Ann N Y Acad Sci 993: 103–114
Rivera C et al. (2005) Two developmental switches in GABAergic signalling: the K+–Cl− cotransporter KCC2 and carbonic anhydrase CAVII. J Physiol 562: 27–36
Cordero-Erausquin M et al. (2005) Differential maturation of GABA action and anion reversal potential in spinal lamina I neurons: impact of chloride extrusion capacity. J Neurosci 25: 9613–9623
De Koninck Y (2007) Altered chloride homeostasis in neurological disorders: a new target. Curr Opin Pharmacol 7: 93–99
Parsons CG (2001) NMDA receptors as targets for drug action in neuropathic pain. Eur J Pharmacol 429: 71–78
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This article has been written in the memory of Steven C Hebert, who passed away during the final months of its preparation. He will be remembered for his keen intelligence, scientific integrity, and, above all, friendship.
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Kahle, K., Staley, K., Nahed, B. et al. Roles of the cation–chloride cotransporters in neurological disease. Nat Rev Neurol 4, 490–503 (2008). https://doi.org/10.1038/ncpneuro0883
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DOI: https://doi.org/10.1038/ncpneuro0883
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