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[P187]: Transverse and longitudinal domains in the forebrain of elasmobranch embryos revealed by Pax6, tyrosine hydroxylase, calretinin, and GAD immunostaining
Author(s) -
FerreiroGalve S.,
Carrera I.,
Candal E.,
Anadón R.,
RodríguezMoldes I.
Publication year - 2006
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/j.ijdevneu.2006.09.247
Subject(s) - calretinin , humanities , philosophy , biology , immunohistochemistry , immunology
Introduction: Disruption of myelin causes severe diseases such as multiple sclerosis. Although recent studies demonstrated that oligodendrocyte precursor cell (OPC) expresses immunoglobulin Fc receptors (FcR-gamma) and has a role in triggering Fyn tyrosine kinase signaling in myelination, the ligand for FcR-gamma remain poorly understood. Here, we report a direct interaction between IgG and MBP involved in FcRgamma activation. Methods: The cerebral hemispheres and spinal cords from 4month-old wild type and cuprizone-induced demyelinated mice were homogenized. The samples were immunoprecipitated with anti-IgG Fab fragment or Fc fragment antibody. Western blot (WB) analyses were performed with anti MBP antibody to detect four MBP isoforms, 14.0, 17.0, 18.5 and 21.5 kDa bands. B cell-deficient ( MT), which lack circulating Igs and shiverer mutant mice, which lack MBP in CNS were employed as negative controls for IgG and MBP respectively. To examine the role of MBP in myelination, OPCs were stimulated with either IgG or IgG + MBP and compared to those with PGDF and T3 + T4 stimulations as positive controls. Results: In MT WB, a single band of MBP 14.0 kDa was detected. On the other hand, in shiverer mise, no band was observed. In the cerebral hemispheres of cuprizone fed mice, reduced expressions of four MBP bands were observed in comparison with those in the controls. However, in the spinal cords of cuprizone fed mice, the 21.5 kDa band was significantly more expressed than the other three bands compared with the controls. The OPC stimulation study resulted in more increased expressions of four bands in IgG + MBP stimulation, and morphologies of OPCs were in well-differentiated shapes than those in IgG stimulation. Discussion: Our results suggest that IgG has a high binding affinity with MBP in vivo and that the IgG–MBP immune complex induces OPC differentiation via stimulated Fyn signaling pathway by FcR-gamma cross-linking.