Reduction of Shp-2 expression by small interfering RNA reduces murine embryonic stem cell-derived in vitro hematopoietic differentiation.

Shp-2 is a member of a small family of cytoplasmic Src homology 2 (SH2) domain-containing protein tyrosine phosphatases. Although Shp-2 has been shown to be necessary for hematopoiesis using a mouse model expressing a mutant residual protein (Shp-2(delta/delta)), we used small interfering RNA (siRNA) to reduce Shp-2 expression and examined the consequences on embryonic stem cell (ESC)-derived hemangioblast, primitive, and definitive hematopoietic development. We found that at a concentration of 50 nM, Shp-2 siRNA effectively diminished Shp-2 expression in differentiating embryoid bodies. Hemangioblast, primitive, and definitive hematopoietic progenitor formation was decreased significantly after transfection with Shp-2 siRNA but not with scrambled siRNA. Because Shp-2 is involved in signals emanating from the basic fibroblast growth factor (bFGF) receptor, we asked whether Shp-2 functions in bFGF-mediated hemangioblast development. Reduction of Shp-2 expression using siRNA, but not scrambled siRNA, blocked the bFGF-induced increase in hemangioblast development. Using siRNA as an independent method of reducing Shp-2 function, in contrast to the mutant mouse model (Shp-2(delta/delta)) previously used, we demonstrate that Shp-2 is required in hemangioblast, primitive, and definitive progenitor hematopoietic development and that Shp-2 is integrally necessary for bFGF-mediated hemangioblast production.