Figure 1

Molecular interactions between human pluripotent stem cells (hPSCs) and culture surfaces. A schematic diagram of a single hPSC illustrates molecular interactions with reported hPSC culture surfaces through different ligands and CAM subtypes. Specific ligands and cell adhesion molecules (CAMs) are included if they have been reported in hPSC attachment and/or culture studies. CAMs involved in hPSC adhesion include integrin subtypes α5β1 (green), αvβ5 (red), αvβ3 (purple), α6β1 (blue) and α2β1 (navy blue), E-cadherin (black blocks), heparan sulphate proteoglycans (HSPGs; dashed blue lines) and unidentified CAMs (orange). Ligands are portrayed as coloured ovals and include the SMB domain of vitronectin (yellow/red), GKKQRFRHRNRKG (orange/red), KGGPQVTRGDVFTMP (red/dark red), AG-10 (CGGNRWHSIYITRFG; blue/dark blue), C-16 (CGGKAFDITYVRLKF; purple/navy blue), AG-73 (CGGRKRLQVQLSIRT; yellow/orange), GRGDSP (green) and laminin E8 fragments (light blue/blue). The ligands are presented by ECMPs [represented by curved coloured lines: laminin-511 or −322 (blue), laminin-111 (navy blue), vitronectin (red), fibronectin (green) collagen (yellow)] or synthetic surfaces (thick black lines) including Synthemax^TM, StemAdhere^TM and PMEDSAH. On the left of the image complex extracellular matrix extracts (eg. Matrigel^TM and Geltrex^TM) are illustrated as combinations of ECMPs, and on the right cell-cell adhesion is simplified in the extreme to illustrate homophilic E-cadherin binding. Where specific ECMP ligands are poorly-defined, CAMs are shown to interact with the ECMP line. Where specific CAMs have not been identified the orange CAM is used, and undefined, adsorbed ligands are represented by orange ovals with a white question mark. This figure is a greatly simplified and stylised representation of the cell-surface and cell-cell adhesion interactions important for hPSCs and discussed in this review.