Transcriptome profiles acquired during cell expansion and licensing validate mesenchymal stromal cell lineage genes

Abstract

Background 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. Methods 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. Results 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. Conclusion 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.

Deciphering Tumor Niches: Lessons From Solid and Hematological Malignancies

“…Similar stromal cells with salient features of CAR cells have been identified in human adult BM (10,71). In line with these findings, the CXCL12/CXCR4 axis is key in immunosuppression and metastatic spread in solid tumors, through reciprocal crosstalk between FAP High CAFs and regulatory T cells (Tregs), as well as FAP High CAFs and cancer cells, respectively (24,25,27).…”

“…Similar stromal cells with salient features of CAR cells have been identified in human adult BM ( 10 , 71 ). In line with these findings, the CXCL12/CXCR4 axis is key in immunosuppression and metastatic spread in solid tumors, through reciprocal crosstalk between FAP High CAFs and regulatory T cells (Tregs), as well as FAP High CAFs and cancer cells, respectively ( 24 , 25 , 27 ). In addition to CXCR4 and CXCL12, numerous studies have shown that chemokines act at different levels in the progression of the primary tumor, modulating both tumor cell proliferation, apoptosis, invasion, angiogenesis, recruitment of immune cells and resistance to chemotherapy ( 72 – 76 ).…”

“…Therefore, there are no common MSCs in adult tissues, reflecting the fact that the nature and properties of the globally termed “MSCs” likely represent different cellular entities ( 21 , 22 ). Since their initial definition in the early 1990’s ( 23 ), the properties of MSCs have been largely explored and debated, even with an attempt at establishing a molecular signature ( 24 ). However, a consensus on the definition and use of the term “MSC” is unlikely to be reached.…”

The Multi-Therapeutic Role of MSCs in Diabetic Nephropathy

“…Recently, increasing attention is being focused on mesenchymal stem cell (MSC) therapy. MSCs are specific types of cells under exploration for treatment of human diseases and have been found in tissues including adipose tissue ( 14 ), peripheral blood ( 15 , 16 ), dental pulp ( 17 ), bone marrow ( 18 ), and neonatal tissues, especially in parts of the placenta ( 19 ) and umbilical cord ( 20 , 21 ). The definition of MSCs involves three features: Self-renewal ability; Multi-differentiation potential; Specific surface biomarkers ( 22 , 23 ).…”

Transcriptional Profile of Cytokines, Regulatory Mediators and TLR in Mesenchymal Stromal Cells after Inflammatory Signaling and Cell-Passaging

“…Manufacturing of MSCs for therapeutic purposes often includes extended cell-expansion or inflammatory licensing. Although these cytokines, chemokines, regulatory mediators and TLR candidate genes are known [ 14 ], their profile and modulation under the pressures of cell-expansion and immune activation combination has not been formally investigated. Herein, we have investigated the impact of a combination of inflammation and cell-expansion signals on the transcript profile of genes linked to the immuno-reparative features of AT-MSCs.…”