title: Homocysteine causes disruptions in spinal cord morphology and changes the expression of Pax 1/9 and Sox 9 gene products in the axial mesenchyme.
abstract: BACKGROUND
  Neural tube defects (NTD) involve disruptions in the axial mesenchyme, and are related to an imbalance between folic acid (FA) and homocysteine (Hcy). This study evaluated the effects of FA/Hcy imbalance on cell proliferation and expression of the Pax 1/9 and Sox 9 gene products in the axial mesenchyme of chickens.
  
  
  METHODS
  Embryos were incubated (38°C) and pretreated at 24 h and treated at 46 h of incubation. The experimental groups were: FA-pretreated with saline and treated with 0.5 μg FA/saline; Hcy-pretreated with 50 μl saline and treated with 20 μmol D,L-Hcy/50 μl saline; FA+Hcy-pretreated with 0.5 μg FA/50 μl saline and treated with 20 μmol D,L-Hcy/50 μl saline; and the control embryos were pretreated and treated with saline. Embryos were analyzed at E4 and E6. Immunohistochemistry was performed to identify proliferating cells and the expression of the gene products of Pax 1/9 and Sox 9. Total RNA of the E4 embryos was extracted and a RT-qPCR assay was performed to quantify Pax 1/9 mRNA expression.
  
  
  RESULTS
  Hcy treatment caused spinal NTD and abnormalities in axial mesenchyme development, affecting the distribution of sclerotomal cells and chondrification. Hcy also reduced cell proliferation and changed the expression of Pax 1/9 and Sox 9 in the mesenchyme.
  
  
  CONCLUSIONS
  Our data clarified the relationship between spinal NTD genesis and disruptions of Pax 1/9 and Sox 9 gene products in the axial mesenchyme caused by the FA/Hcy imbalance.
authors.affiliation: Departamento de Biologia Celular, Embriologia e Genética, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Florianópolis, SC, 88040-900, Brazil.
authors.forename: Karoline
authors.initials: K
authors.lastname: Kobus
authors.forename: Dib
authors.initials: D
authors.lastname: Ammar
authors.forename: Evelise Maria
authors.initials: EM
authors.lastname: Nazari
authors.forename: Yara Maria Rauh
authors.initials: YM
authors.lastname: Müller
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects*; D002642:Chick Embryo; D017931:DNA Primers / Q000235:genetics; D005494:Folic Acid Deficiency / Q000097:blood*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology*; D006710:Homocysteine / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology; D007150:Immunohistochemistry; D008648:Mesoderm / Q000378:metabolism*; D009436:Neural Tube Defects / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D051764:PAX9 Transcription Factor / Q000378:metabolism; D051761:Paired Box Transcription Factors / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D051764:PAX9 Transcription Factor; D051761:Paired Box Transcription Factors; D006710:Homocysteine; C070835:PAX1 transcription factor