title: Regulation of ethanol-sensitive EAAT2 expression through adenosine A1 receptor in astrocytes.
abstract: Adenosine-regulated glutamate signaling in astrocytes is implicated in many neurological and neuropsychiatric disorders. In this study, we examined whether adenosine A1 receptor regulates EAAT2 expression in astrocytes using pharmacological agents and siRNAs. We found that adenosine A1 receptor-specific antagonist DPCPX or PSB36 decreased EAAT2 expression in a dose-dependent manner. Consistently, knockdown of A1 receptor in astrocytes decreased EAAT2 mRNA expression while overexpression of A1 receptor upregulated EAAT2 expression and function. Since A1 receptor activation is mainly coupled to inhibitory G-proteins and inhibits the activity of adenylate cyclase, we investigated the effect of forskolin, which activates adenylate cyclase activity, on EAAT2 mRNA levels. Interestingly, we found that forskolin reduced EAAT2 expression in dose- and time-dependent manners. In contrast, adenylate cyclase inhibitor SQ22536 increased EAAT2 expression in dose- and time-dependent manners. In addition, forskolin blocked ethanol-induced EAAT2 upregulation. Taken together, these results suggest that A1 receptor-mediated signaling regulates EAAT2 expression in astrocytes.
authors.affiliation: Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Wu
authors.forename: Moonnoh R
authors.initials: MR
authors.lastname: Lee
authors.forename: Taehyun
authors.initials: T
authors.lastname: Kim
authors.forename: Sandy
authors.initials: S
authors.lastname: Johng
authors.forename: Suzanne
authors.initials: S
authors.lastname: Rohrback
authors.forename: Nayoung
authors.initials: N
authors.lastname: Kang
authors.forename: Doo-Sup
authors.initials: DS
authors.lastname: Choi
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000437:Alcoholism / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D005576:Colforsin / Q000494:pharmacology; D033721:Equilibrative Nucleoside Transporter 1 / Q000235:genetics; D000431:Ethanol / Q000633:toxicity*; D027342:Excitatory Amino Acid Transporter 2 / Q000096:biosynthesis* / Q000235:genetics; D055785:Gene Knockdown Techniques; D051379:Mice; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D043682:Receptor, Adenosine A1 / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D033721:Equilibrative Nucleoside Transporter 1; D027342:Excitatory Amino Acid Transporter 2; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D043682:Receptor, Adenosine A1; C498476:SLC29A1 protein, mouse; C493396:Slc1a2 protein, mouse; D005576:Colforsin; D000431:Ethanol; D000262:Adenylyl Cyclases