Experimental angiogenesis: strategy for the functional study of the transcription factors of the Ets family during morphogenesis of the vascular tree

During morphogenesis of the vascular tree, the massive outgrowth of primiti ve capillaries is followed by the development and the maturation of some ca pillary branches whereas others regress. The direct observation and the man ipulation of in vivo models, including a series of recent knock-out experim ents, allow to delineate the mechanisms controlling this process, and to id entify factors involved in the formation of a mature capillary, surrounded with a basal lamina and pericytes. The expression of several members of the Ets family of transcription factors, Ets1, Erg and Fli, correlates with th e occurrence of invasive processes, such as angiogenesis during normal and pathological development. The description of the phenotype of cultured endo thelial cells expressing the DNA binding domain of Ets1 suggests that membe rs of the Ets family take part in the morphogenesis of the vascular tree. A lthough transient transfection experiments allowed the identification of pu tative targets genes for Ets1 during angiogenesis, deciphering the Ets1 reg ulation networks remains a major goal for the future.