A Comprehensive Stemness Gene Expression Analysis Signifies the Role of ABC Transporters and Molecular Chaperons in...

The major aim of this study was to identify the most common stemness genes across different stem cell types and further validate them in human fetal subventricular zone-derived primary and cultured neural precursor cells (NPCs). This study involved the use of a unique method of stemness meta-analysis (SMA) for investigating comprehensive upregulation and downregulation of differentially expressed genes (DEGs) among different stem cell populations.

A total of 55 mouse and human data sets targeting crucial genes identified in seven different types of stem cells population were screened and subjected to independent DEGs analysis using SMA. Identified 30 meta-gene signatures were subjected to functional enrichment analysis based on their biological processes and molecular functions. Validation of enriched meta-gene signatures was performed using RT-qPCR. Cellular localization of ABCB1 and ABCG2 was identified using immunofluorescence staining, whereas functional assessment was performed using western-blot.

SMA analysis revealed that among 52 commonly expressed genes, 30 genes were either upregulated or downregulated in at least two stem cell populations. Further gene enrichment analysis showed nine genes (ABCB1, ABCG2, HSPA4, HSPA9, HSPA14, Nestin, Sox-2, Oct-4, and Notch-2) with the highest combined scores among 30 meta-gene signatures. RT-qPCR demonstrated that all the enriched gene signatures were significantly upregulated in primary NPCs and further downregulated during NPCs lineage differentiation in culture except HSPA4, HSPA9, and HSPA14 gene transcripts.

The stemness meta-gene signatures were abundantly expressed in human NPCs population which categorically suggest the involvement of these genes/pathways in pluripotency maintenance and molecular switches for lineage differentiation while HSP-70 had a neuroprotective effect.