Investigating the Odontogenic Potential of Human Induced Pluripotent Stem Cells-derived Mesenchymal Progenitor Cells in Comparison to Stem Cells of the Apical Papilla

Introduction Over the past 2 decades, numerous researchers have focused on identifying cell populations capable of regenerating the pulp-dentin complex. Most research focused on dental tissue-derived mesenchymal stromal cells (dMSCs), which possess multipotent differentiation potential and can be isolated from various dental tissues. However, these dMSCs have limitations, prompting researchers to explore alternative cell sources that offer greater scalability and sustained regenerative potential while preserving the unique expression and functional profile of dMSCs. This study aimed to test the odontogenic properties of mesenchymal progenitor cells derived from human induced pluripotent stem cells (i-MPCs) as a promising alternative to dMSCs. Methods Patient-specific human-induced pluripotent stem cells were differentiated to generate mesenchymal progenitors via a cranial neural crest intermediate, replicating embryonic tooth development. The expression profile of the i-MPCs was assessed and compared to stem cells of the apical papilla (SCAPs) through a panel of cell surface markers: CD90, CD73, CD105, CD13, CD14, CD271, CD57, and CD146, using flow cytometry, differentiation potential through trilineage differentiation assays, and average gene expression through bulk RNA sequencing. The odontogenic differentiation (OD) potential of the cell types was determined and compared after odontogenic induction using RNA sequencing and proteomics analysis, Alizarin red staining, and alkaline phosphatase quantification. Results The i-MPCs demonstrated CD90⁺, CD73⁺, CD105⁺, CD13⁺, CD14⁻, CD271⁻, CD57⁻, and CD146⁺ and their trilineage differentiation capabilities were comparable to SCAPs. The average gene expression revealed a clear distinction, with the highest expression of neural and embryonic markers in i-MPCs and odontogenic markers in SCAPs. The proteomics analysis revealed a higher baseline expression of proteins involved in OD and mineralization in SCAPs. In contrast, the differentiated cells revealed enrichment in more common pathways responsible for OD in i-MPCs. The Alizarin red staining and quantification confirmed the OD of both cell types through mineralization and calcification at 7 and 14 days. Alkaline phosphatase activity of the OD cells significantly increased on days 7 and 14 in the i-MPCs, compared to SCAPs. Conclusions i-MPCs and SCAPs demonstrated comparable phenotypic characteristics, with distinct transcriptomic profiles and expressions associated with their origin. Proteomics analysis of the odontogenically induced cells revealed more significant enrichment of OD pathways in i-MPCs compared to SCAPs, indicating a stronger response to differentiation cues.