Molecular basis for RGD-containing peptides supporting adhesion and self-renewal of human pluripotent stem cells on synthetic surface

The ability to obtain a large number of human pluripotent stem cells (hPSCs) under chemically defined conditions plays a key role in clinical application of hPSCs. Chemically defined, economical and effective synthetic peptide displaying surfaces should be the optimal choice for clinical applications involving hPSCs. However, synthetic peptide displaying surfaces are worse than Matrigel surface in supporting cell adhesion and self-renewal. Moreover, the correlations between peptide amino acid sequences and the ability of peptides to support cell survival has never been investigated in hPSCs. In this study, we focused on the Arg-Gly-Asp (RGD) sequence and integrin receptors, which constitute the major recognition system for cell adhesion. Several new RGD-containing peptides were designed by altering the amino acids surrounding the RGD sequence. We investigated the ability of these peptides to sustain hPSC survival, and identified the Ac-KGGPQVTRGDTYRAY sequence, which was capable of supporting cell reprogramming, long-term self-renewal and lineage differentiation. In addition, this report demonstrates that the introduction of mutations in the amino acids surrounding the RGD sequence is a good strategy to design peptides that display excellent adhesion properties and promote hPSC self-renewal. Our results will help improve the current understanding of the mechanisms by which RGD-containing peptides exhibit different abilities in sustaining hPSC culture, and will promote clinical application of both peptide displaying surfaces and hPSCs.