title: Acid-sensing ion channels contribute to the increase in vesicular release from SH-SY5Y cells stimulated by extracellular protons.
abstract: Acid-sensing ion channels (ASICs) have been reported to play a role in the neuronal dopamine pathway, but the exact role in neurotransmitter release remains elusive. Human neuroblastoma SH-SY5Y is a dopaminergic neuronal cell line, which can release monoamine neurotransmitters. In this study, the expression of ASICs was identified in SH-SY5Y cells to further explore the role of ASICs in vesicular release stimulated by acid. We gathered evidence that ASICs could be detected in SH-SY5Y cells. In whole cell patch-clamp recording, a rapid decrease in extracellular pH evoked inward currents, which were reversibly inhibited by 100 μM amiloride. The currents were pH dependent, with a pH of half-maximal activation (pH(0.5)) of 6.01 ± 0.04. Furthermore, in calcium imaging and FM 1-43 dye labeling, it was shown that extracellular protons increased intracellular calcium levels and vesicular release in SH-SY5Y cells, which was attenuated by PcTx1 and amiloride. Interestingly, N-type calcium channel blockers inhibited the vesicular release induced by acidification. In conclusion, ASICs are functionally expressed in SH-SY5Y cells and involved in vesicular release stimulated by acidification. N-type calcium channels may be involved in the increase in vesicular release induced by acid. Our results provide a preliminary study on ASICs in SH-SY5Y cells and neurotransmitter release, which helps to further investigate the relationship between ASICs and dopaminergic neurons.
authors.affiliation: Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Qiu-Ju
authors.initials: QJ
authors.lastname: Xiong
authors.forename: Zhuang-Li
authors.initials: ZL
authors.lastname: Hu
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Wu
authors.forename: Lan
authors.initials: L
authors.lastname: Ni
authors.forename: Zhi-Fang
authors.initials: ZF
authors.lastname: Deng
authors.forename: Wen-Ning
authors.initials: WN
authors.lastname: Wu
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Chen
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
mesh_terms: D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D045744:Cell Line, Tumor; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015640:Ion Channel Gating / Q000502:physiology*; D007473:Ion Channels / Q000502:physiology*; D018408:Patch-Clamp Techniques; D010539:Permeability; D011188:Potassium / Q000378:metabolism; D011522:Protons; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D007473:Ion Channels; D011522:Protons; D011188:Potassium; D002118:Calcium