title: Ischemia Increases TREK-2 Channel Expression in Astrocytes: Relevance to Glutamate Clearance.
abstract: The extent of an ischemic insult is less in brain regions enriched in astrocytes suggesting that astrocytes maintain function and buffer glutamate during ischemia. Astrocytes express a wide variety of potassium channels to support their functions including TREK-2 channels which are regulated by polyunsaturated fatty acids, intracellular acidosis and swelling; conditions that pertain to ischemia. The present study investigated the possible involvement of TREK-2 channels in cultured cortical astrocytes during experimental ischemia (anoxia/hypoglycemia) by examining TREK-2 protein levels, channel activity and ability to clear glutamate. We found that TREK-2 protein levels were increased rapidly within 2 hrs of the onset of simulated ischemia. This increase corresponded to an increase in temperature-sensitive TREK-2-like channel conductance and the ability of astrocytes to buffer extracellular glutamate even during ischemia. Together, these data suggest that up-regulation of TREK-2 channels may help rescue astrocyte function and lower extracellular glutamate during ischemia.
authors.affiliation: Department of Biochemistry, Universidad Central del Caribe, Bayamón, Puerto Rico.
authors.forename: Lilia Y
authors.initials: LY
authors.lastname: Kucheryavykh
authors.forename: Yuriy V
authors.initials: YV
authors.lastname: Kucheryavykh
authors.forename: Mikhail
authors.initials: M
authors.lastname: Inyushin
authors.forename: Yaroslav M
authors.initials: YM
authors.lastname: Shuba
authors.forename: Priscila
authors.initials: P
authors.lastname: Sanabria
authors.forename: Luis A
authors.initials: LA
authors.lastname: Cubano
authors.forename: Serguei N
authors.initials: SN
authors.lastname: Skatchkov
authors.forename: Misty J
authors.initials: MJ
authors.lastname: Eaton