title: Ultrafine carbon black induces glutamate and ATP release by activating connexin and pannexin hemichannels in cultured astrocytes.
abstract: Ultrafine particles could enter central nervous system and were associated with brain damage. The underlying mechanisms have not been fully elucidated. Glutamate and ATP are important signaling molecules in brain physiology and pathology. We investigated whether ultrafine carbon black (ufCB) could regulate the release of glutamate and ATP from cultured cortical astrocytes and the involvement of hemichannels in the release mechanism. Our results showed that ufCB dose-dependently increased glutamate and ATP release and activated hemichannels in astrocytes. ufCB-activated hemichannels were attributed to the activation of both connexin 43 (Cx43) and pannexin1 (Panx1) hemichannels, which was based on the finding of increased protein expression and distribution on cell surface of Cx43 and Panx1, and the inhibiting effects of hemichannel inhibitor carbenoxolone, Cx43 hemichannel inhibitor (43)Gap27 and Panx1 hemichannel inhibitor (10)Panx1 on hemichannel activation. Furthermore, ufCB-induced glutamate and ATP release were dependent on Cx43 and Panx1 hemichannels, because carbenoxolone and (43)Gap27 inhibited ufCB-induced glutamate and ATP release, and (10)Panx1 inhibited ufCB-induced ATP release. Taken together, we demonstrated, for the first time, that ufCB could induce glutamate and ATP release by activating Cx43 and Panx1 hemchannels in astrocytes. Our findings suggest a novel mechanism for neurotoxicity caused by ultrafine particles.
authors.affiliation: Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, No. 38 Xueyuan Road, Beijing 100191, China.
authors.forename: Hongying
authors.initials: H
authors.lastname: Wei
authors.affiliation: Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, No. 38 Xueyuan Road, Beijing 100191, China.
authors.forename: Furong
authors.initials: F
authors.lastname: Deng
authors.affiliation: Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, No. 38 Xueyuan Road, Beijing 100191, China.
authors.forename: Yiyong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, No. 38 Xueyuan Road, Beijing 100191, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Qin
authors.affiliation: Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, No. 38 Xueyuan Road, Beijing 100191, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Hao
authors.affiliation: Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, No. 38 Xueyuan Road, Beijing 100191, China. Electronic address: guoxb@bjmu.edu.cn.
authors.forename: Xinbiao
authors.initials: X
authors.lastname: Guo
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D018031:Connexin 43 / Q000378:metabolism; D017630:Connexins / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010316:Particle Size; D017207:Rats, Sprague-Dawley; D053260:Soot / Q000633:toxicity*
chemical_list: D018031:Connexin 43; D017630:Connexins; C580592:Gja1 protein, rat; D009419:Nerve Tissue Proteins; D053260:Soot; C479936:pannexin 1, rat; D018698:Glutamic Acid; D000255:Adenosine Triphosphate
keywords: ATP; Glutamate; Hemichannel; Neurotoxicity; Ultrafine carbon black; Ultrafine particles