Mesenchymal stromal cells (MSCs) are rapidly advancing as commercial therapeutics. However, there are still no adequate tools to validate the identity of MSCs and support standardization of MSC-based products. Currently accepted metrics include cell surface marker profiling and tri-lineage differentiation assays, neither of which is definitive. Transcript profiling represents a cost- and time-effective approach amenable to MSC manufacturing processes. Two independent labs recently reported non-overlapping MSC-specific transcriptomic signatures of 489 and 16 genes. Here, we interrogated our repository of transcriptome data to determine whether routine culture manipulations including cell expansion and immune activation affect expression of the reported MSC lineage genes. These data sets comprise 4 donor populations of human umbilical cord (UC) MSCs serially cultured from cryopreservation thaw through pre-senescence, and 3 donor populations each of naïve UC and bone marrow (BM) MSCs and licensed by 3 different cytokines. Overall, 437 of 456 proposed signature genes assessed in these data sets were reliably expressed, representing an enduring lineage profile in 96% agreement with the previous studies. Serial passaging resulted in the downregulation of 3 signature genes, and one was silenced. Cytokine stimulation downregulated expression of 16 signature genes, and 3 were uniformly silenced in one or the other MSC type. Fifteen additional genes were unreliably detected, independent of culture manipulation. These results validate and refine the proposed transcriptomic tools for reliable identification of MSCs after isolation through cell expansion and after inflammatory activation. We propose a 24-gene signature to support standardized and accessible MSC characterization.

中文翻译：

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在细胞扩增和许可过程中获得的转录组谱证实了间充质基质细胞谱系基因。

间充质基质细胞（MSC）迅速发展为商业疗法。但是，仍然没有足够的工具来验证MSC的身份并支持基于MSC的产品的标准化。目前公认的指标包括细胞表面标志物谱分析和三谱系分化测定法，两者都不是确定的。成绩单分析代表了一种适用于MSC制造过程的经济高效的方法。两家独立实验室最近报告了489和16个基因的非重叠MSC特异性转录组特征。在这里，我们询问了转录组数据存储库，以确定常规的培养操作（包括细胞扩增和免疫激活）是否影响所报道的MSC谱系基因的表达。这些数据集包括从冷冻保存解冻到衰老前连续培养的4个人脐带（UC）MSC供体群体，以及分别由3种不同的细胞因子许可的初次UC和骨髓（BM）MSC的3个供体群体。总体而言，在这些数据集中评估的456个提议的签名基因中有437个被可靠地表达，代表着持久的谱系谱，与以前的研究一致，达96％。连续传代导致3个签名基因的下调，其中一个沉默。细胞因子刺激下调了16个签名基因的表达，其中3个在一种或另一种MSC类型中均被沉默。不可靠地检测到另外15个基因，与培养操作无关。这些结果验证和完善了拟议的转录组学工具，用于通过细胞扩增分离和炎症激活后可靠鉴定MSC。我们提出了24基因签名，以支持标准化和可访问的MSC表征。