Data_Sheet_2_Retracing Schwann Cell Developmental Transitions in Embryonic Dissociated DRG/Schwann Cell Cocultures in Mice.DOCX

Embryonic Dissociated Dorsal Root Ganglia (DRG) cultures are often used to investigate the role of novel molecular pathways or drugs in Schwann cell development and myelination. These cultures largely recapitulate the order of cellular and molecular events that occur in Schwann cells of embryonic nerves. However, the timing of Schwann cell developmental transitions, notably the transition from Schwann Cell Precursors (SCP) to immature Schwann cells (iSC) and then to myelinating Schwann cells, has not been estimated so far in this culture system. In this study, we determined the expression profiles of Schwann cell developmental genes during the first week of culture and then compared our data to the expression profiles of these genes in developing spinal nerves. This helped in identifying that SCP transition into iSC between the 5th and 7th day in vitro. Furthermore, we also investigated the transition of immature cells into pro-myelinating and myelinating Schwann cells upon the induction of myelination in vitro. Our results suggest that Schwann cell differentiation beyond the immature stage can be observed as early as 4 days post the induction of myelination in cocultures. Finally, we compared the myelinating potential of coculture-derived Schwann cell monocultures to cultures established from neonatal sciatic nerves and found that both these culture systems exhibit similar myelinating phenotypes. In effect, our results allow for a better understanding and interpretation of coculture experiments especially in studies that aim to elucidate the role of a novel actor in Schwann cell development and myelination.

胚胎解离背根神经节（DRG）培养体系常被用于探究新型分子通路或药物在施万细胞（Schwann cell）发育与髓鞘形成过程中的作用。该培养体系可在很大程度上重现胚胎神经内施万细胞所经历的细胞与分子事件的发生顺序。然而，截至目前，该培养体系中施万细胞发育转变的时间节点，尤其是从施万细胞前体细胞（Schwann Cell Precursors, SCP）向未成熟施万细胞（immature Schwann cells, iSC），再向髓鞘形成型施万细胞的转变时序，尚未得到明确估算。本研究首先测定了培养第一周内施万细胞发育相关基因的表达谱，并将所得数据与发育中脊髓神经内的对应基因表达谱进行比对，由此确定施万细胞前体细胞可在体外培养第5至7天转化为未成熟施万细胞。此外，我们还探究了体外诱导髓鞘形成后，未成熟施万细胞向前髓鞘形成型及髓鞘形成型施万细胞的转变过程。研究结果显示，在共培养体系中，施万细胞超越未成熟阶段的分化最早可在髓鞘形成诱导后4天被观测到。最后，我们将共培养来源的施万细胞单培养体系与新生坐骨神经来源的培养体系的髓鞘形成能力进行对比，发现二者展现出相似的髓鞘形成表型。综上，本研究结果有助于更好地理解与解读共培养实验结果，尤其适用于旨在阐明新型调控因子在施万细胞发育与髓鞘形成中作用的相关研究。