Gene expression changes with differentiation of cord blood stem cells to respiratory epithelial cells: a preliminary observation

Control and experimental cells were cultured in maintenance medium (mesenchymal stem cell growth medium) or differentiation medium (small airway growth medium (SAGM)), respectively, for 8 days. Total RNA was isolated from control and experimental groups for gene expression profiling and real-time polymerase chain reaction assay.Analysis of only mixed cell lines (n = 2) with parameters including a P value of 0.01 and an intergroup gap of 2.0 yielded a set of 373 differentially expressed genes. Prominently upregulated genes included several genes associated with ATII cells and also lung cancers: ALDH3A1, VDR and CHKA. Several upregulated genes have been shown to be integral or related to ATII functioning: SGK1, HSD17B11 and LEPR. Finally, several upregulated genes appear to play a role in lung cancers, including FDXR and GP96. Downregulated genes appear to be associated with bone, muscle and central nervous system tissues as well as other widespread tissues.To the best of our knowledge, this accounting of the gene expression changes associated with the differentiation of a human UCB-derived stem cell toward an ATII cell represents the first such effort. Dissecting which components of SAGM affect specific gene regulation events is warranted.Boyse first proposed the use of human umbilical cord blood (UCB) for therapeutic reconstitution (Boyse EA et al., unpublished), and later Broxmeyer et al. [1] showed that the frequency of hematopoietic progenitor cells in this graft source surpassed that found in bone marrow. Researchers now commonly utilize UCB as a source of mesenchymal stromal cells (MSCs) [2], and several investigators have reported success in isolating pluripotent stem cells [3,4]. Owing to wide availability, low cost and avoidance of ethical problems, UCB provides an attractive source of stem cells for investigational and therapeutic uses, including cell therapy approaches to treating lung diseases [5,6].Recently, some of the molecular and cell biological feat