title: Expression of the high-affinity choline transporter, CHT1, in the neuronal and non-neuronal cholinergic system of human and rat skin.
abstract: Choline is an essential component in acetylcholine biosynthesis, and is involved in cell signaling. It is unable to permeate the cell membrane and requires a transporter to enter the cell. Neurons that synthesize acetylcholine take up choline by a recently cloned high-affinity choline transporter (choline transporter 1) that is Na+-dependent and can be blocked by hemicholinium-3. The aim of this study was to determine the expression and to analyze the distribution of choline transporter 1 in human and rat skin. The mRNA for choline transporter 1 was detected in rat and human skin and in the human keratinocyte cell line HaCaT. A polyclonal anti-serum was developed against the N-terminal region of the human and rat protein. In rat and human skin, choline transporter 1 immunoreactivity was present in nerve fibers. In addition, keratinocytes, HaCaT cells and cells of the internal root sheath of the hair follicle contained choline transporter 1 immunoreactivity. The labeling patterns of nonconfluent vs confluent cultured cells and the distribution of choline transporter 1 along the epidermal layer suggest an association of choline transporter 1 with keratinocyte differentiation. In conclusion, this study shows the presence of the high-affinity choline transporter choline transporter 1 in nerve fibers and epithelial cells in the human and rat skin supporting the pivotal role of this transporter in both the neuronal and non-neuronal cholinergic system of the skin.
authors.affiliation: Institute for Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany. rainer.v.haberberger@anatomie.med.uni-giessen.de
authors.forename: Rainer Viktor
authors.initials: RV
authors.lastname: Haberberger
authors.forename: Uwe
authors.initials: U
authors.lastname: Pfeil
authors.forename: Katrin Susanne
authors.initials: KS
authors.lastname: Lips
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kummer
mesh_terms: D000818:Animals; D002460:Cell Line; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000737:chemistry; D026901:Membrane Transport Proteins / Q000032:analysis* / Q000235:genetics / Q000502:physiology; D009474:Neurons / Q000737:chemistry*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012867:Skin / Q000737:chemistry / Q000294:innervation*
chemical_list: D026901:Membrane Transport Proteins; D012333:RNA, Messenger; C065637:choline transporter