title: Erythropoietin attenuates neurological and histological consequences of toxic demyelination in mice.
abstract: Erythropoietin (EPO) reduces symptoms of experimental autoimmune encephalomyelitis in rodents and shows neuroregenerative effects in chronic progressive multiple sclerosis. The mechanisms of action of EPO in these conditions with shared immunological etiology are still unclear. Therefore, we used a model of toxic demyelination allowing exclusion of T cell-mediated inflammation. In a double-blind (for food/injections), placebo-controlled, longitudinal four-arm design, 8-wk-old C57BL/6 mice (n = 26/group) were assigned to cuprizone-containing (0.2%) or regular food (ground chow) for 6 wks. After 3 wks, mice were injected every other day with placebo or EPO (5,000 IU/kg intraperitoneally) until the end of cuprizone feeding. Half of the mice were exposed to behavioral testing, magnetic resonance imaging (MRI) and histology immediately after treatment cessation, whereas the other half were allowed a 3-wk treatment-free recovery. Immediately after termination of cuprizone feeding, all toxin-exposed mice were compromised regarding vestibulomotor function/coordination, with EPO-treated animals performing better than placebo. Likewise, ventricular enlargement after cuprizone, as documented by MRI, was less pronounced upon EPO. After a 3-wk recovery, remarkable spontaneous improvement was observed in all mice with no measurable further benefit in the EPO group ("ceiling effect"). Histological analysis of the corpus callosum revealed attenuation by EPO of the cuprizone-induced increase in microglial numbers and amyloid precursor protein accumulations as a readout of inflammation and axonal degeneration. To conclude, EPO ameliorates neurological symptoms in the cuprizone model of demyelination, possibly by reduction of inflammation-associated axonal degeneration in white matter tracts. These findings underscore the value of future therapeutic strategies for multiple sclerosis based on EPO or EPO variants.
authors.affiliation: Division of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany.
authors.forename: Nora
authors.initials: N
authors.lastname: Hagemeyer
authors.forename: Susann
authors.initials: S
authors.lastname: Boretius
authors.forename: Christoph
authors.initials: C
authors.lastname: Ott
authors.forename: Axel
authors.initials: A
authors.lastname: Von Streitberg
authors.forename: Henrike
authors.initials: H
authors.lastname: Welpinghus
authors.forename: Swetlana
authors.initials: S
authors.lastname: Sperling
authors.forename: Jens
authors.initials: J
authors.lastname: Frahm
authors.forename: Mikael
authors.initials: M
authors.lastname: Simons
authors.forename: Pietro
authors.initials: P
authors.lastname: Ghezzi
authors.forename: Hannelore
authors.initials: H
authors.lastname: Ehrenreich
mesh_terms: D016564:Amyloid beta-Protein Precursor / Q000378:metabolism; D000818:Animals; D001369:Axons / Q000473:pathology; D002552:Cerebral Ventricles / Q000473:pathology; D003337:Corpus Callosum / Q000187:drug effects / Q000473:pathology; D003471:Cuprizone; D003711:Demyelinating Diseases / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology*; D004921:Erythropoietin / Q000008:administration & dosage / Q000627:therapeutic use*; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000187:drug effects / Q000473:pathology; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004856:Postural Balance; D011597:Psychomotor Performance
chemical_list: D016564:Amyloid beta-Protein Precursor; D018696:Neuroprotective Agents; D004921:Erythropoietin; D003471:Cuprizone