Paez Pablo M, García Corina I, Campagnoni Anthony T, Soto Eduardo F, Pasquini Juana M
Instituto de Química y Fisicoquímica Biológica (IQUIFIB), UBA-CONICET, and Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
Glia. 2005 Oct;52(1):1-15. doi: 10.1002/glia.20214.
We have previously demonstrated that the addition of apotransferrin (aTf) to oligodendroglial cell (OLGc) primary cultures accelerates their maturation. Cells treated with aTf developed a multipolar morphology and displayed increased expression of mature OLGc markers. In this work, we studied the effect of Tf overexpression in two OLGc lines, N19 and N20.1. The former cells exhibit characteristics of OLGc precursors (O2A), while N20.1 cells express markers of more mature OLGcs. Using the complete cDNA of the human Tf gene, we obtained clones overexpressing Tf in both cell lines. These clones were evaluated for the expression of OLGc differentiation markers. In agreement with our previous results, we found that in the cells overexpressing Tf, there was an increased O(4), GC, and MBP immunoreactivity. To study the myelinogenic potential of these cells, we co-cultured N19 and N20.1 Tf-transfected cells together with cortical neurons. There was a dramatic increase in the morphological differentiation of the OLGcs accompanied by enhanced GC and MBP expression. The OLGcs appeared to establish contact with neurites and extend their processes along them. Only two MBP isoforms were detected in Tf-overexpressing clones, while all the isoforms were present in the co-cultures, suggesting that there was a modulation of MBP expression by neurons. Concomitantly, we found an increase in several proteins involved in axon-glia interaction, such as MAG, N-CAM, and F3/Contactin. This co-culture system represents a potentially powerful tool to study neuron-glia interactions that occur during myelinogenesis and the role of Tf in this process.
我们先前已证明，向少突胶质细胞（OLGc）原代培养物中添加脱铁转铁蛋白（aTf）可加速其成熟。用aTf处理的细胞呈现多极形态，并显示成熟OLGc标志物的表达增加。在这项研究中，我们研究了转铁蛋白（Tf）过表达在两种OLGc细胞系N19和N20.1中的作用。前一种细胞表现出少突胶质细胞前体（O2A）的特征，而N20.1细胞表达更成熟的OLGc标志物。利用人Tf基因的完整cDNA，我们在两种细胞系中获得了过表达Tf的克隆。对这些克隆进行了少突胶质细胞分化标志物表达的评估。与我们先前的结果一致，我们发现，在过表达Tf的细胞中，O(4)、GC和髓鞘碱性蛋白（MBP）的免疫反应性增加。为了研究这些细胞的髓鞘形成潜力，我们将N19和N20.1 Tf转染细胞与皮质神经元共培养。少突胶质细胞的形态分化显著增加，同时GC和MBP的表达增强。少突胶质细胞似乎与神经突建立了接触，并沿着神经突延伸其突起。在过表达Tf的克隆中仅检测到两种MBP异构体，而在共培养物中所有异构体均存在，这表明神经元对MBP表达有调节作用。同时，我们发现几种参与轴突-胶质细胞相互作用的蛋白质增加，如髓鞘相关糖蛋白（MAG）、神经细胞黏附分子（N-CAM）和F3/接触蛋白（Contactin）。这种共培养系统是研究髓鞘形成过程中发生的神经元-胶质细胞相互作用以及Tf在此过程中作用的潜在有力工具。
