Comparative Proteomic Analysis of Primary Schwann Cells and a Spontaneously Immortalized Schwann Cell Line RSC 96: A Comprehensive Overview with a Focus on Cell Adhesion and Migration Related Proteins

Schwann cells (SCs) are the principal glial cells of
the peripheral
nervous system (PNS). As a result of tissue heterogeneity and difficulties
in the isolation and culture of primary SCs, a considerable understanding
of SC biology is obtained from SC lines. However, the differences
between the primary SCs and SC lines remain uncertain. In the present
study, quantitative proteomic analysis based on isobaric tags for
relative and absolute quantitation (iTRAQ) labeling was conducted
to obtain an unbiased view of the proteomic profiles of primary rat
SCs and RSC96, a spontaneously immortalized rat SC line. Out of 1757
identified proteins (FDR < 1%), 1702 were quantified, while 61
and 78 were found to be, respectively, up- or down-regulated (90%
confidence interval) in RSC96. Bioinformatics analysis indicated the
unique features of spontaneous immortalization, illustrated the dedifferentiated
state of RSC96, and highlighted a panel of novel proteins associated
with cell adhesion and migration including CADM4, FERMT2, and MCAM.
Selected proteomic data and the requirement of these novel proteins
in SC adhesion and migration were properly validated. Taken together,
our data collectively revealed proteome differences between primary
SCs and RSC96, validated several differentially expressed proteins
with potential biological significance, and generated a database that
may serve as a useful resource for studies of SC biology and pathology.

雪旺细胞（Schwann cells, SCs）是周围神经系统（peripheral nervous system, PNS）的主要胶质细胞。受限于组织异质性以及原代雪旺细胞分离与培养的技术难点，学界对雪旺细胞生物学特性的诸多认知均来源于雪旺细胞系。然而，原代雪旺细胞与雪旺细胞系之间的差异仍未明确。本研究采用基于同量异位素标记相对和绝对定量（isobaric tags for relative and absolute quantitation, iTRAQ）标记的定量蛋白质组学分析策略，以无偏视角解析原代大鼠雪旺细胞与自发永生化大鼠雪旺细胞系RSC96的蛋白质组表达谱。在鉴定得到的1757种蛋白质（错误发现率false discovery rate, FDR < 1%）中，共完成定量的蛋白质为1702种；在RSC96细胞中，分别有61种和78种蛋白质呈现上调或下调表达（置信区间90%）。生物信息学分析揭示了该自发永生化过程的独特分子特征，阐明了RSC96的去分化状态，并重点筛选出一批与细胞黏附及迁移相关的新型蛋白质，包括CADM4、FERMT2与MCAM。研究对选定的蛋白质组学数据以及这些新型蛋白质在雪旺细胞黏附与迁移中的功能需求进行了有效验证。综上，本研究明确了原代雪旺细胞与RSC96之间的蛋白质组差异，验证了一批具备潜在生物学意义的差异表达蛋白质，并构建了可用于雪旺细胞生物学与病理学研究的实用数据库资源。