title: The use of mammalian cultured cells loaded with a fluorescent dye shows specific membrane penetration of undissociated acetic acid.
abstract: Acetic acid induces unique physiological responses in mammalian cells. Our previous study found that fura-2-loaded human embryonic kidney (HEK) 293T cells showed a robust intracellular fluorescence response immediately after stimulation with acetic acid, and no such response in the case of citric acid. In the present study, we aimed to identify the unique characteristics of acetic acid responsible for this phenomenon. We found that one such feature is its hydrophobicity. We also discovered that acetic acid induces cell responses by intracellular acidification. Of the components of acetic acid in solution (protons, acetate ions, and undissociated acetic acid), undissociated acetic acid might be the functional unit that penetrates the lipid bilayer of cell membranes to acidify the intracellular environment, thereby inducing cell responses. The method used in this study might be convenient in evaluating the intracellular acidification of cultured cells by acids in the external environment.
authors.affiliation: Central Research Institute, Mizkan Group Co., Handa, Aichi, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Ishii
authors.forename: Mikiya
authors.initials: M
authors.lastname: Kishi
authors.forename: Keigo
authors.initials: K
authors.lastname: Yamagami
authors.forename: Shinji
authors.initials: S
authors.lastname: Okada
authors.forename: Keiko
authors.initials: K
authors.lastname: Abe
authors.forename: Takumi
authors.initials: T
authors.lastname: Misaka
mesh_terms: D019342:Acetic Acid / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism*; D016257:Fura-2 / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D042541:Intracellular Space / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D010539:Permeability / Q000187:drug effects
chemical_list: D005456:Fluorescent Dyes; D019342:Acetic Acid; D016257:Fura-2