Stiffness of the Extracellular Matrix Has Opposite Effects on Angiogenesis and Vasculogenesis In Vitro

摘要

Neovascularization occurs primarily via two mechanisms: angiogenesis and vasculogenesis. Angiogenesis is the formation of new blood vessels from preexisting capillaries, and vasculogenesis is the construction of new vessels from precursor cells. We used cell culture models of neovascularization with model ECM to investigate the effects of tissue stiffness on sprouting angiogenesis and vasculogenesis. Gel stiffness was modified by addition of a thrombin crosslinker to the ECM. Vasculogenesis was significantly decreased on the crosslinked (stiff) gels relative to the noncrosslinked (soft) gels. While en-dothelial cells (ECs) invaded every type of ECM in angiogenesis assay, only on stiff gels, the ECs arranged into capillary-like structures. Our results suggest that ECM stiffness has opposite effects on angiogenesis and vasculogenesis in vitro.