title: Intracellular chloride ion concentration in differentiating neuronal cell and its role in growing neurite.
abstract: Chloride ion (Cl-) is one of the most abundant anions in our body. Increasing evidence suggests that Cl-plays fundamental roles in various cellular functions. We have previously reported that electroneutral cation-chloride cotransporters, such as Na+-K+-2Cl-cotransporter 1 (NKCC1) and K+-Cl-cotransporter 1 (KCC1), are involved in neurite outgrowth during neuronal differentiation. In the present study, we studied if there is correlation between intracellular Cl-concentrations ([Cl-]i) and the length of growing neurites. We measured [Cl-]iin the cell body and growing neurite tips using halide-sensitive fluorescent dye N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide (MQAE), revealing that [Cl-]iin the tip of growing neurite was higher than that in cell body in a single cell. Importantly, there was a significant positive correlation between the length of growing neurite and [Cl-]iin neurite tip. Bumtanide (BMT), an inhibitor of NKCC1, significantly inhibited neurite outgrowth and decreased [Cl-]iin neurite tip. The results obtained in the present study and our previous studies together strongly suggest that high [Cl-]iin neurite tip region is crucial for efficient neurite outgrowth.
authors.affiliation: Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto 602-8566, Japan. Electronic address: k-nakaji@koto.kpu-m.ac.jp.
authors.forename: Ken-Ichi
authors.initials: KI
authors.lastname: Nakajima
authors.affiliation: Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto 602-8566, Japan; Department of Bio-Ionomics, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto 602-8566, Japan. Electronic address: marunaka@koto.kpu-m.ac.jp.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Marunaka
mesh_terms: D000818:Animals; D002034:Bumetanide / Q000737:chemistry; D049109:Cell Proliferation; D002712:Chlorides / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D049990:Membrane Transport Modulators / Q000737:chemistry; D016501:Neurites / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D016716:PC12 Cells; D011806:Quinolinium Compounds / Q000737:chemistry; D051381:Rats; D064506:Solute Carrier Family 12, Member 2 / Q000378:metabolism; D012997:Solvents / Q000737:chemistry
chemical_list: D002712:Chlorides; D049990:Membrane Transport Modulators; D011806:Quinolinium Compounds; C578879:Slc12a2 protein, rat; D064506:Solute Carrier Family 12, Member 2; D012997:Solvents; D002034:Bumetanide; C085493:N-(ethoxycarbonylmethyl)-6-methoxyquinolinium; D004121:Dimethyl Sulfoxide
keywords: Intracellular chloride ion concentration; Neurite; PC12 cell