Method: Replicative senescence of EDK6, iPDK2 and BJ fibroblasts was induced by serial passaging of these cells over three months. RNA was extracted from early (p8) and late (p19-20) passaged cells and relative levels of gene expression for SASP including IL-8, IL-6, IGF-1, HGF, and VEGF were determined by RT-PCR.
Result: In vitro replicative capacity of EDK6, iPDK2 and BJ fibroblasts was assessed by calculating the number of population doublings (PDs) during serial subculture. While a decline in PDs of EDK6 and iPDK2 was observed at p19, BJ underwent an earlier decrease in PDs (p13). As assessed by RT-PCR, levels of SASP RNA expression increased with passage number in EDK and iPDK, while a decrease in SASP RNA expression was seen with increasing passage of BJ fibroblasts.
Conclusion: These results demonstrate prolonged growth potential and stable secretory profile of EDK6 and iPDK2 when compared to BJ. This indicates that fibroblasts derived from iPSC may acquire replicative properties that exceed those of the somatic cells from which they were derived. The sustained growth potential and secretory microenvironment of iPSC-derived fibroblasts demonstrate that these cells may have applications for future regenerative therapies.
Keywords: Aging, Fibroblasts, Gene expression, Regeneration and Stem Cells