Figure 1: Derivation of iMSCs and the comparison of molecular signatures.
From: Efficient Generation of Chemically Induced Mesenchymal Stem Cells from Human Dermal Fibroblasts
(A) The experimental scheme for efficient derivation of iMSCs from dermal fibroblasts with 6 chemicals with or without LIF, TGF-β, and bFGF. Expanded iMSCs with clonal expansion ability (clonogenicity) can be further differentiated into different lineages (multipotency) or treat sepsis-induced acute lung injury in the mouse model. (B) The representative flow cytometry analysis of human dermal fibroblasts CRL2097, iMSCs, and BMMSCs with MSC functional markers SSEA-4 and PODXL. SSEA-4 and PODXL were abundantly expressed in iMSCs and BMMSCs, but not in fibroblasts. (C) Clonogenicity of fibroblasts, iMSCs, and BMMSCs. By a 96-well colony formation assay, quantitation of CFU-F in fibroblasts (1 per 112 cells), iMSCs (1 per 7 cells), and BMMSCs (1 per 22 cells) was obtained by the negative linear relationship between the number of seeded cells and the percentage of wells with no colonies. (D) Flow cytometry analysis of OCT4 protein expression in human fibroblasts, iMSCs, BMMSCs, and human embryonic stem cells (hESCs). The pluripotent marker OCT4 was at a basal level in fibroblasts (CRL2097), slightly up-regulated in iMSCs and BMMSCs, and highly expressed in hESCs. (E) The principal component analysis of the expression of stemness genes in three different dermal fibroblasts (CRL2097, DF440547, and DF443480), iMSCs induced from the three different fibroblasts, and two independent sources of BMMSCs (BMMSC_1: primary human bone marrow MSCs used throughout this study; BMMSC_2: publicly available gene expression data for human BMMSCs with accession number GSM1533333). Expression probes were functionally annotated with Gene Ontology (GO) and selected by text-mining for the term “stem cell maintenance” in R (418 probes). Principal component 1 accounts for 40%, principal component 2 accounts for 19%, and principal component 3 accounts for 14% of the variation in the dataset. The clustering of iMSCs derived from three different fibroblast sources between two different BMMSCs suggests the robust efficacy of the cocktail.
