Endothelial Progenitor Cells in Acute Ischemic Kidney Injury: Strategies for Increasing the Cells' Renoprotective Competence

Table 1

Biological properties of “early outgrowth” as opposed to “late outgrowth” EPCs (see text).

“Early outgrowth” EPCs	“Late outgrowth” EPCs
Proliferate in culture after 5–7 days (fibronectin coated dishes)	Proliferate in culture after 21 days (collagen type 2 coated dishes)
Express endothelial and hematopoietic cell marker molecules (CD133, CD45 and CD14)	Do not express hematopoietic but endothelial cell marker molecules
Capable of differentiating into hematopoietic cells	Do not differentiate into hematopoietic cells
Low proliferative activity	High proliferative activity
Minimal endothelial tube formation in vitro	Significant endothelial tube formation in vitro
Proangiogenic activity in vivo	Proangiogenic activity in vivo
⇒Proangiogenic hematopoietic cells	⇒ “True” (?) progenitors of endothelial cells