title: Expression and localization of aquaporin-4 in sensory ganglia.
abstract: Aquaporin-4 (AQP4) is a water channel protein that is predominantly expressed in astrocytes in the CNS. The rapid water flux through AQP4 may contribute to electrolyte/water homeostasis and may support neuronal activities in the CNS. On the other hand, little is known about the expression of AQP4 in the peripheral nervous system (PNS). Using AQP4(-/-) mice as a negative control, we demonstrated that AQP4 is also expressed in sensory ganglia, such as trigeminal ganglia and dorsal root ganglia in the PNS. Immunohistochemistry revealed that AQP4 is exclusively localized to satellite glial cells (SGCs) surrounding the cell bodies of the primary afferent sensory neurons in the sensory ganglia. Biochemical analyses revealed that the expression levels of AQP4 in sensory ganglia were considerably lower than those in astrocytes in the CNS. Consistently, behavioral analyses did not show any significant difference in terms of mechanical and cold sensitivity between wild type and AQP4(-/-) mice. Overall, although the pathophysiological relevance of AQP4 in somatosensory perception remains unclear, our findings provide new insight into the involvement of water homeostasis in the peripheral sensory system.
authors.affiliation: Department of Pharmacology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Department of Anesthesiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
authors.forename: Jungo
authors.initials: J
authors.lastname: Kato
authors.affiliation: Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-cho, Aoba-ku, Sendai, Miyagi 980-8574, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Takai
authors.affiliation: Department of Pharmacology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
authors.forename: Mariko Kato
authors.initials: MK
authors.lastname: Hayashi
authors.affiliation: Department of Pharmacology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Department of Pharmacology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
authors.forename: Manami
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Department of Pharmacology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Sohma
authors.affiliation: Department of Pharmacology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Abe
authors.affiliation: Department of Pharmacology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan. Electronic address: myasui@a3.keio.jp.
authors.forename: Masato
authors.initials: M
authors.lastname: Yasui
mesh_terms: D000818:Animals; D051401:Aquaporin 4 / Q000096:biosynthesis*; D001253:Astrocytes / Q000378:metabolism; D003080:Cold Temperature; D017950:Ganglia, Sensory / Q000378:metabolism*; D006706:Homeostasis; D051379:Mice; D009457:Neuroglia / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D051401:Aquaporin 4; D014867:Water
keywords: AQP4; Satellite glial cells; Sensory ganglia; The peripheral nervous system; Water homeostasis