TY - JOUR
T1 - Targeting a potassium channel/syntaxin interaction ameliorates cell death in ischemic stroke
AU - Yeh, Chung Yang
AU - Bulas, Ashlyn M.
AU - Moutal, Aubin
AU - Saloman, Jami L.
AU - Hartnett, Karen A.
AU - Anderson, Charles T.
AU - Tzounopoulos, Thanos
AU - Sun, Dandan
AU - Khanna, Rajesh
AU - Aizenman, Elias
N1 - Publisher Copyright:
© 2017 the authors.
PY - 2017/6/7
Y1 - 2017/6/7
N2 - The voltage-gated K+ channel Kv2.1 has been intimately linked with neuronal apoptosis. After ischemic, oxidative, or inflammatory insults, Kv2.1 mediates a pronounced, delayed enhancement of K+ efflux, generating an optimal intracellular environment for caspase and nuclease activity, key components of programmed cell death. This apoptosis-enabling mechanism is initiated via Zn2--dependent dual phosphorylation of Kv2.1, increasing the interaction between the channel’s intracellular C-terminus domain and the SNARE(soluble N-ethylmaleimide-sensitive factor activating protein receptor) protein syntaxin 1A. Subsequently, an upregulation of de novo channel insertion into the plasma membrane leads to the critical enhancement of K+ efflux in damaged neurons. Here, we investigated whether a strategy designed to interfere with the cell death-facilitating properties of Kv2.1, specifically its interaction with syntaxin 1A, could lead to neuroprotection following ischemic injury in vivo. The minimal syntaxin 1A-binding sequence of Kv2.1 C terminus (C1aB) was first identified via a far-Western peptide screen and used to create a protherapeutic product by conjugating C1aB to a cell-penetrating domain. The resulting peptide (TAT-C1aB) suppressed enhanced whole-cell K+ currents produced by a mutated form of Kv2.1 mimicking apoptosis in a mammalian expression system, and protected cortical neurons from slow excitotoxic injury in vitro, without influencing NMDA-induced intracellular calcium responses. Importantly, intraperitoneal administration of TAT-C1aB in mice following transient middle cerebral artery occlusion significantly reduced ischemic stroke damage and improved neurological outcome. These results provide strong evidence that targeting the proapoptotic function of Kv2.1 is an effective and highly promising neuroprotective strategy.
AB - The voltage-gated K+ channel Kv2.1 has been intimately linked with neuronal apoptosis. After ischemic, oxidative, or inflammatory insults, Kv2.1 mediates a pronounced, delayed enhancement of K+ efflux, generating an optimal intracellular environment for caspase and nuclease activity, key components of programmed cell death. This apoptosis-enabling mechanism is initiated via Zn2--dependent dual phosphorylation of Kv2.1, increasing the interaction between the channel’s intracellular C-terminus domain and the SNARE(soluble N-ethylmaleimide-sensitive factor activating protein receptor) protein syntaxin 1A. Subsequently, an upregulation of de novo channel insertion into the plasma membrane leads to the critical enhancement of K+ efflux in damaged neurons. Here, we investigated whether a strategy designed to interfere with the cell death-facilitating properties of Kv2.1, specifically its interaction with syntaxin 1A, could lead to neuroprotection following ischemic injury in vivo. The minimal syntaxin 1A-binding sequence of Kv2.1 C terminus (C1aB) was first identified via a far-Western peptide screen and used to create a protherapeutic product by conjugating C1aB to a cell-penetrating domain. The resulting peptide (TAT-C1aB) suppressed enhanced whole-cell K+ currents produced by a mutated form of Kv2.1 mimicking apoptosis in a mammalian expression system, and protected cortical neurons from slow excitotoxic injury in vitro, without influencing NMDA-induced intracellular calcium responses. Importantly, intraperitoneal administration of TAT-C1aB in mice following transient middle cerebral artery occlusion significantly reduced ischemic stroke damage and improved neurological outcome. These results provide strong evidence that targeting the proapoptotic function of Kv2.1 is an effective and highly promising neuroprotective strategy.
KW - Apoptosis
KW - Ischemia
KW - Neuroprotection
KW - Potassium channel
KW - Syntaxin
KW - Zinc
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UR - http://www.scopus.com/inward/citedby.url?scp=85020404245&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.3811-16.2017
DO - 10.1523/JNEUROSCI.3811-16.2017
M3 - Article
C2 - 28483976
AN - SCOPUS:85020404245
SN - 0270-6474
VL - 37
SP - 5648
EP - 5658
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 23
ER -