title: Fine-mapping resolves Eae23 into two QTLs and implicates ZEB1 as a candidate gene regulating experimental neuroinflammation in rat.
abstract: BACKGROUND
  To elucidate mechanisms involved in multiple sclerosis (MS), we studied genetic regulation of experimental autoimmune encephalomyelitis (EAE) in rats, assuming a conservation of pathogenic pathways. In this study, we focused on Eae23, originally identified to regulate EAE in a (LEW.1AV1xPVG.1AV1)F2 cross. Our aim was to determine whether one or more genes within the 67 Mb region regulate EAE and to define candidate risk genes.
  
  
  RESULTS
  We used high resolution quantitative trait loci (QTL) analysis in the 10th generation (G10) of an advanced intercross line (AIL) to resolve Eae23 into two QTLs that independently regulate EAE, namely Eae23a and Eae23b. We established a congenic strain to validate the effect of this region on disease. PVG alleles in Eae23 resulted in significant protection from EAE and attenuated CNS inflammation/demyelination. Disease amelioration was accompanied with increased levels of Foxp3(+) cells in the CNS of the congenic strain compared to DA. We then focused on candidate gene investigation in Eae23b, a 9 Mb region linked to all clinical phenotypes. Affymetrix exon arrays were used to study expression of the genes in Eae23b in the parental strains, where none showed differential expression. However, we found lower expression of exon 4 of ZEB1, which is specific for splice-variant Zfhep1. ZEB1 is an interleukin 2 (IL2) repressor involved in T cell development. The splice-specific variance prompted us to next analyze the expression of ZEB1 and its two splice variants, Zfhep1 and Zfhep2, in both lymph node and spleen. We demonstrated that ZEB1 splice-variants are differentially expressed; severity of EAE and higher IL2 levels were associated with down-regulation of Zfhep1 and up-regulation of Zfhep2.
  
  
  CONCLUSIONS
  We speculate that the balance between splice-variants of ZEB1 could influence the regulation of EAE. Further functional studies of ZEB1 and the splice-variants may unravel novel pathways contributing to MS pathogenesis and inflammation in general.
authors.affiliation: Center for Molecular Medicine, Department of Clinical Neuroscience, Neuroimmunology Unit, Karolinska Institutet, Stockholm, Sweden. pernilla.strid@ki.se
authors.forename: Pernilla
authors.initials: P
authors.lastname: Stridh
authors.forename: Melanie
authors.initials: M
authors.lastname: Thessen Hedreul
authors.forename: Amennai Daniel
authors.initials: AD
authors.lastname: Beyeen
authors.forename: Milena Z
authors.initials: MZ
authors.lastname: Adzemovic
authors.forename: Hannes
authors.initials: H
authors.lastname: Laaksonen
authors.forename: Alan
authors.initials: A
authors.lastname: Gillett
authors.forename: Johan
authors.initials: J
authors.lastname: Ockinger
authors.forename: Monica
authors.initials: M
authors.lastname: Marta
authors.forename: Hans
authors.initials: H
authors.lastname: Lassmann
authors.forename: Kristina
authors.initials: K
authors.lastname: Becanovic
authors.forename: Maja
authors.initials: M
authors.lastname: Jagodic
authors.forename: Tomas
authors.initials: T
authors.lastname: Olsson
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000235:genetics* / Q000276:immunology; D005260:Female; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000235:genetics* / Q000276:immunology; D040641:Quantitative Trait Loci; D012326:RNA Splicing; D051381:Rats; D014157:Transcription Factors / Q000235:genetics* / Q000276:immunology; D000071799:Zinc Finger E-box-Binding Homeobox 1
chemical_list: D018398:Homeodomain Proteins; D014157:Transcription Factors; C000630720:ZEB1 protein, rat; D000071799:Zinc Finger E-box-Binding Homeobox 1