MICROVASCULAR ENDOTHELIAL-CELLS FROM E-SELECTIN-DEFICIENT MICE FORM TUBES IN-VITRO

Studies of capillary morphogenesis and angiogenesis in vitro have sugg ested a role for E-selectin (CD62E) in the process of differentiation into tube-like structures. Recent studies by our group and others have demonstrated that mice lacking E-selectin because of germline inactiv ation of the E-selectin gene by gene targeting are viable and fertile, without apparent deficiencies in vascular development. Murine lung en dothelial cells from wild-type and E-selectin-deficient animals were i solated using an activation-dependent sterile sorting method, and diff erentiation into tube-like structures on sparse fibronectin, Matrigel, and collagen gels was compared. Both types of murine lung endothelial cells spontaneously organized to form multicellular tubes and extensi ve anastomotic networks. There were no major differences in either the time course of development or the general appearance of the multicell ular cords or tube-like structures formed by murine lung endothelial c ells from wild-type or E-selectin-deficient mice, although different p atterns were observed on different extracellular matrices. These studi es, thus, demonstrate that E-selectin is not required for morphogenesi s of 3-dimensional vascular structures in vitro.