Proliferation and Differentiation of Mouse Embryonic Stem Cells Modified by the Neural Growth Factor (NGF) Gene

The effect of the nerve growth factor (NGF) on the proliferation and differentiation of mouse embryonic stem cells (ESCs) during long-term culturing in vitro was studied using genetically modified cells with stable expression of ngf and gfp (green fluorescent protein) genes (clone R₁^NGF). It was shown that, under standard conditions in vitro with the addition of mouse cytokine LIF, R₁^NGF cells lose their adhesive properties and acquire the ability to form cellular conglomerates or embryoid bodies (EBs) spontaneously. It is noted that, after attachment to the surface of the culture on days 3–5, EBs differentiated towards the neuroectoderm, as evidenced by the appearance of markers of early (nestin) and late (vimentin) neural differentiation. During long-term cultivation up to 22 days, the production of endogenous NGF protein promotes predominant selection and survival of neuroectodermal derivatives.