Effects of substrate stiffness on the biological behavior of human umbilical vein endothelial cells

Background: The biophysical attributes of a substrate can directly influence endothelial cell behaviors. Here, we explored substrate stiffness and its biological impact on human umbilical vein endothelial cell (HUVEC) behavior, representing different anatomical sites and differentiation states in vivo. Material and Methods: HUVECs were cultured on both stiff substrate (25 kPa hydrogel GEL) and tissue culture plastic (TCP). Cell cytoskeleton and proliferation were detected by immunofluorescence and BrdU assays, respectively. The protein and gene expression levels of connexin 40 (CX40) were ascertained via Western blotting analysis and quantitative real-time polymerase chain reaction. Glycosaminoglycan (GAG) content was determined using a sulfated GAG detection kit. Results: Results showed that actin stress fiber density and HUVEC proliferation both decreased, whereas CX40 expression and GAG content both increased in the cells grown on the stiff substrate compared to cells grown on the TCP. Conclusions: Following culture on the stiff substrate, the biological behavior of the HUVECs differed obviously to those cultured on the TCP. Our results suggest that the state of the cells cultured on the stiff substrate may be similar to their phenotypic state in vivo.