A Global Transcriptome Analysis of BMSC Senescence. Homo sapiens

Bone marrow stromal cells (BMSCs) can be expanded by serial passage, but expansion is limited by cell senescence. The nature of changes associated with BMSC serial passages was assessed. Transcriptome analysis of 10 early and 15 late passage samples from 5 subjects revealed 2193 differentially expressed genes; those highly expressed in early passage cells were overrepresented in skeletal system development, embryonic morphogenesis, tube morphogenesis, etc, while those highly expressed in the late passage BMSCs were overrepresented in nucleosome assembly; chromatin assembly, DNA packaging, etc. 57 BMSC samples from 7 donors were further analyzed for the transition from an early to late passage; 155 genes were highly correlated with BMSC senescence and a set of 24 genes was predictive of BMSCs lifespan. The change from an early to a late passage molecular signature occurred between passage 3 and 5. In contrast, senescence associated beta-galactosidase staining began to increase after passage 6 or 7 and colony formation efficiency began to fall after passage 7. These data indicated that the onset of molecular changes associated with BMSC passage varied among individuals and preceded changes in commonly used indicators of BMSC senescence. The set of 24 BMSC lifespan predictive genes will be useful in assessing the quality of clinical BMSC products. Overall design: We performed gene expression profiling on serial passages of BMSCs from 7 healthy donors (09FC20, 09FC37, 09FC43, 09FC44, 09FC45, 09FC49, and W10003).

骨髓基质细胞（Bone marrow stromal cells, BMSCs）可通过连续传代实现体外扩增，但扩增能力会受到细胞衰老的限制。本研究针对BMSCs连续传代过程中相关变化的本质进行了解析。对来自5名受试者的10份早期传代样本与15份晚期传代样本开展转录组分析（transcriptome analysis），共鉴定出2193个差异表达基因（differentially expressed genes）；早期传代细胞中高表达的基因在骨骼系统发育、胚胎形态发生、管形态发生等生物学过程中显著富集，而晚期传代BMSCs中高表达的基因则显著富集于核小体组装（nucleosome assembly）、染色质组装（chromatin assembly）、DNA包装（DNA packaging）等生物学过程。
本研究进一步对7名供体来源的57份BMSCs样本进行分析，以探究BMSCs从早期到晚期传代的转变历程；最终筛选出155个与BMSCs衰老高度相关的基因，并构建了由24个基因组成的BMSCs寿命预测特征集。BMSCs从早期到晚期传代的分子特征谱转变发生在第3代至第5代之间。与之相对，衰老相关β-半乳糖苷酶染色（senescence associated beta-galactosidase staining）信号在第6或7代后开始增强，而集落形成效率（colony formation efficiency）则在第7代后出现显著下降。上述数据表明，与BMSCs传代相关的分子变化的启动时机存在个体差异，且早于当前常用的BMSCs衰老检测指标的变化。这套24个BMSCs寿命预测基因可有效用于临床BMSCs产品的质量评估。
研究整体设计：本研究对7名健康供体（09FC20、09FC37、09FC43、09FC44、09FC45、09FC49及W10003）的BMSCs连续传代样本进行了基因表达谱分析（gene expression profiling）。