title: IL-6-trans-signalling increases rapid-eye-movement sleep in rats.
abstract: Interleukin 6 (IL-6), a cytokine of the gp130-signalling-family, plays an important role in immediate immunological functions, in metabolism and in the central nervous system. IL-6-signalling is mediated by classic-signalling via the membrane bound IL-6 receptor or by IL-6-trans-signalling via the soluble IL-6 receptor. Whereas the receptor subunit gp130 is ubiquitously expressed within the body, IL-6 receptor expression is restricted to distinct cell populations. Within the brain parenchyma the IL-6 receptor is sparsely expressed, and therefore the brain is mostly dependent on IL-6-trans-signalling in its response to IL-6. Recently we have shown that IL-6-trans-signalling but not classic-signalling plays a pivotal role in the establishment and maintenance of chronic inflammation and cancer, whereas its role in sleep regulation has not been studied so far. We reasoned that the IL-6-trans-signalling mimetic Hyper-IL-6 which in contrast to IL-6 alone can activate almost all cells of the brain might have a profound effect on sleep regulation and performed sleep recordings with rats injected with recombinant Hyper-IL-6. In the present study, the i.c.v. administration of the designer cytokine Hyper-IL-6 into rats at dark onset increased the amount of rapid-eye-movement sleep (REM sleep) but did not affect non-rapid-eye-movement sleep (non-REM sleep). Our data define a new role of IL-6-trans-signalling in sleep regulation.
authors.affiliation: Biochemisches Institut, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: May
authors.forename: Thomas
authors.initials: T
authors.lastname: Schiffelholz
authors.forename: Paul Christian
authors.initials: PC
authors.lastname: Baier
authors.forename: James M
authors.initials: JM
authors.lastname: Krueger
authors.forename: Stefan
authors.initials: S
authors.lastname: Rose-John
authors.forename: Jürgen
authors.initials: J
authors.lastname: Scheller
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D032701:Biomimetics; D001921:Brain / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D004569:Electroencephalography; D006801:Humans; D015850:Interleukin-6 / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects*; D012895:Sleep, REM / Q000187:drug effects* / Q000502:physiology; D014851:Wakefulness / Q000187:drug effects / Q000502:physiology
chemical_list: D015850:Interleukin-6; D011993:Recombinant Fusion Proteins