This project aims at determining whether IVIG influence Schwann cell homeostasis and maturation and could thus be used to promote nerve regeneration in different nerve pathologies. Methods: We performed our investigations on three different primary Schwann cell culture systems: (a) na?ve (immature) Schwann cells, (b) differentiating Schwann cells and (c) myelinating co\cultures of Schwann cells. Results: Our findings show that primary rat Schwann cells respond to IVIG stimulation with altered cell morphologies accompanied by an accelerated growth of cellular protrusions in early stages of the differentiation process. depending on the presence of other transcription factor/co\factors at different stages of the oligodendrogenesis. Method: To further elucidate the function of Nkx2.2 during oligodendrogenesis, primary Nkx2.2 target genes were identified in murine Ol progenitor cells (OPC) and differentiated Ols by chromatin immunoprecipitation combined with DNA sequencing. Furthermore, the transcriptome were investigated in OPC/Ol containing CNS structures of postnatal Nkx2.2 deficient and wild type mice by microarray, qPCR, and in situ hybridization. Results: In total, 14.470 putative primary Nkx2.2 target genes were identified in OPCs and/or Ols of which 51 were significantly lower expressed in Nkx2.2 deficient mice. These genes included Nkx2.2, the known target genes; Mbp, Plp1, and Sirt2, and several genes with known or possible roles AMG 579 in cell division, myelination, myelin compaction, and axonal protection suggesting that Nkx2.2 activates the expression of these genes in OPCs and/or Ols. Since many of these genes appear to be target genes in OPCs and Ols, although they are not expressed by both cell types, the results of this study open the possibility that Nkx2. 2 works as activator and repressor at different stages of the oligodendrogenesis. Higher NG2 and PDGFR mRNA levels and an apparently higher number of NG2 and PDGFR expressing OPCs in the Nkx2.2 deficient mice suggest that Nkx2.2 is important for the terminal Ol differentiation including myelination, but not for the cell fate specification of OPCs in the developing murine CNS. Conclusion: Nkx2.2 has impact on the expression of several genes with known or possible roles in cell division, myelination, myelin compaction, and axonal protection. T01\01B. Influence of ECM substrate and chemotropic molecule interactions on OPC migration and differentiation D.?Harlow, W.?Macklin University of Colorado School of Medicine, Aurora, United States Oligodendrocyte progenitor cells (OPCs) migrate long distances before differentiating and myelinating axons. It is well established that both short AMG 579 and long\range soluble guidance factors, as well as contact with the surrounding extracellular matrix (ECM) and neighboring cells, can modulate OPC FAE migration and differentiation. However, the influence of cell\matrix interactions on OPC responses to guidance molecules is less clear. Previous studies of OPC migration in response to semaphorins and netrin\1 yielded inconsistent results, but these studies were performed on a variety of ECM substrates, i.e., explants, collagen, poly\D\lysine. In the current study, we systematically studied OPC migration in response to guidance AMG 579 factors on several different ECM substrates, to better understand the influence of ECM interactions on OPC responses to chemotropic molecules. Understanding the regulation of OPC migration and differentiation has important implications for the treatment of demyelinating diseases such as Multiple AMG 579 Sclerosis (MS). For example, semaphorins 3A and 3F are expressed in active, but not chronic, MS lesions, and in demyelination/remyelination studies in animal models, semaphorins influence OPC migration into lesions, affecting the rate at which remyelination occurs. In addition, aberrant expression of ECM ligands occurs in and around MS lesions. We performed live imaging experiments of OPC migration on different ECM substrates in response to gradients of chemotropic molecules. These studies are combined with IHC, co\IP, Western blot and RT\PCR analyses to determine the effects of ECM substrates on OPC migration and signaling pathway responses to chemotropic molecules. Our preliminarily results suggest that ECM substrate can regulate both the direction and rate of OPC migration. Semaphorin 3A is repulsive to OPCs on laminin 1, while on fibronectin OPC migration remains uniform in the presence of semaphorin 3A. Since laminin 1 is the ligand for 61 integrin heterodimers, while OPC migration on fibronectin is mediated by V3 integrins, the repulsive effect of semaphorin 3A appears likely to function through 1 AMG 579 integrin. Thus, signaling through the Neuropilin\Plexin receptor complex that underlies the repulsive effects of semaphorin 3A on OPC migration may be modulated by interactions with 1 integrins. T01\02A. Oligodendrocyte precursor cells generate astrocytes after acute cortical injury X.?Bai University of Saarland, Homburg, Germany Secondary injury processes after acute brain trauma involve activation of different cell types like astrocytes, oligodendrocytes and microglia cells. A complex and yet not completely understood sequence of cellular responses initiate functional recovery after the neurodegeneration process. By using double\transgenic mice GCPB (GFAP\EGFP PLP\DsRed1) mice, we were able to identify a particular type of activated glia expressing astro\ AND oligodendroglial properties simultaneously (AO cells) that transiently appeared after three types of acute cortical injuries (stab wound injury, pial vessel disruption and middle.

This project aims at determining whether IVIG influence Schwann cell homeostasis and maturation and could thus be used to promote nerve regeneration in different nerve pathologies