title: Interleukin-6 released in human cerebrospinal fluid following traumatic brain injury may trigger nerve growth factor production in astrocytes.
abstract: Cytokines are involved in nerve regeneration by modulating the synthesis of neurotrophic factors. The role played by interleukin-6 (IL-6) in promoting nerve growth factor (NGF) after brain injury was investigated by monitoring the release of IL-6 and NGF in ventricular cerebrospinal fluid (CSF) of 22 patients with severe traumatic brain injuries. IL-6 was found in the CSF of all individuals and remained elevated for the whole study period. NGF appeared in the CSF if IL-6 levels reached high concentrations and was often detected simultaneously with or following an IL-6 peak. The amounts of NGF correlated with the severity of the injury, as indicated by the clinical outcome of the patients. The functional relationship of IL-6 and NGF was investigated utilizing cultured mouse astrocytes. The CSF of 8 patients containing IL-6 induced NGF production in astrocytes, whereas control CSF without IL-6 had no effect. The induction of NGF was inhibited up to 100% by adding anti-IL-6 antibodies. These results were corroborated when astrocytes were exposed to recombinant IL-6 at different concentrations resulting in NGF production. Thus, the production of IL-6 within the injured brain may likely contribute to the release of neurotrophic factors by astrocytes.
authors.affiliation: Department of Surgery, University Hospital Zurich, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Kossmann
authors.forename: V
authors.initials: V
authors.lastname: Hans
authors.forename: H G
authors.initials: HG
authors.lastname: Imhof
authors.forename: O
authors.initials: O
authors.lastname: Trentz
authors.forename: M C
authors.initials: MC
authors.lastname: Morganti-Kossmann
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D001930:Brain Injuries / Q000378:metabolism*; D002478:Cells, Cultured / Q000378:metabolism; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000134:cerebrospinal fluid*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000096:biosynthesis*; D014947:Wounds and Injuries / Q000378:metabolism
chemical_list: D015850:Interleukin-6; D009414:Nerve Growth Factors