Mitigation of augmented extrasynaptic NMDAR signaling and apoptosis in cortico-striatal co-cultures from Huntington's disease mice
| Autor: | Ainsley Coquinco, Max S. Cynader, Marja D. Sepers, Lynn A. Raymond, Liang Wang, Clare M. Gladding, Lily Y. J. Zhang, Jing Fan, Alexandra M. Kaufman, Austen J. Milnerwood, Hwan Lee, Joy Yi Qiao, Yu Tian Wang |
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| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Huntingtin
Excitotoxicity Apoptosis Mice Transgenic Biology medicine.disease_cause Neuroprotection Receptors N-Methyl-D-Aspartate lcsh:RC321-571 Glutamatergic Mice Huntington's disease Piperidines Memantine mental disorders medicine Animals Neurodegeneration lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry Cerebral Cortex Neurons musculoskeletal neural and ocular physiology Glutamate receptor medicine.disease NMDA receptor Coculture Techniques Corpus Striatum GluN2B Disease Models Animal GluN2A Huntington Disease Neurology nervous system Neuroscience Excitatory Amino Acid Antagonists Striatal medium spiny neuron Signal Transduction |
| Zdroj: | Neurobiology of Disease, Vol 48, Iss 1, Pp 40-51 (2012) |
| Popis: | We recently reported evidence for disturbed synaptic versus extrasynaptic NMDAR transmission in the early pathogenesis of Huntington's disease (HD), a late-onset neurodegenerative disorder caused by CAG repeat expansion in the gene encoding huntingtin. Studies in glutamatergic cells indicate that synaptic NMDAR transmission increases phosphorylated cyclic-AMP response element binding protein (pCREB) levels and drives neuroprotective gene transcription, whereas extrasynaptic NMDAR activation reduces pCREB and promotes cell death. By generating striatal and cortical neuronal co-cultures to investigate the glutamatergic innervation of striatal neurons, we demonstrate that dichotomous synaptic and extrasynaptic NMDAR signaling also occurs in GABAergic striatal medium-sized spiny neurons (MSNs), which are acutely vulnerable in HD. Further, we show that wild-type (WT) and HD transgenic YAC128 MSNs co-cultured with cortical cells have similar levels of glutamatergic synapses, synaptic NMDAR currents and synaptic GluN2B and GluN2A subunit-containing NMDARs. However, NMDAR whole-cell, and especially extrasynaptic, current is elevated in YAC128 MSNs. Moreover, GluN2B subunit-containing NMDAR surface expression is markedly increased, irrespective of whether or not the co-cultured cortical cells express mutant huntingtin. The data suggest that MSN cell-autonomous increases in extrasynaptic NMDARs are driven by the HD mutation. Consistent with these results, we find that extrasynaptic NMDAR-induced pCREB reductions and apoptosis are also augmented in YAC128 MSNs. Moreover, both NMDAR-mediated apoptosis and CREB-off signaling are blocked by co-application of either memantine or the GluN2B subunit-selective antagonist ifenprodil in YAC128 MSNs. GluN2A-subunit-selective concentrations of the antagonist NVP-AAM077 did not reduce cell death in either genotype. Cortico-striatal co-cultures provide an in vitro model system in which to better investigate striatal neuronal dysfunction in disease than mono-cultured striatal cells. Results from the use of this system, which partially recapitulates the cortico-striatal circuit and is amenable to acute genetic and pharmacological manipulations, suggest that pathophysiological NMDAR signaling is an intrinsic frailty in HD MSNs that can be successfully targeted by pharmacological interventions. |
| Databáze: | OpenAIRE |
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