Sprouty 2 knockdown attenuates the propofol-induced cell death in the human embryonic stem cell (hESC)–derived neurons and increases the expression of pAkt. (A) hESC-derived neurons were transfected with a Sprouty 2 small interfering RNA (siRNA, 20 nm) or a control siRNA for 48 h to knockdown Sprouty 2. Knockdown of Sprouty 2 was assessed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Sprouty 2 expression was significantly reduced in the group treated with the Sprouty 2 siRNA when compared with scramble-transfected cells confirming successful knockdown of Sprouty 2 (a). Knockdown of Sprouty 2 partially attenuated the increase in terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate in situ nick end labeling (TUNEL)–positive cells following exposure of hESC-derived neurons to 6 h of 20 μg/ml propofol (b). (B) hESC-derived neurons were transfected for 48 h with a Sprouty 2 siRNA or a control/scramble siRNA (20 nm). To confirm that Sprouty 2 was indeed acting to suppress the levels of activated Akt, we assessed the expression of pAkt and total Akt after Sprouty 2 knockdown. We found that the expression of pAkt was significantly increased in the group treated with the Sprouty 2 siRNA when compared with the scramble-transfected cells. **P < 0.01 versus Scramble, #P < 0.01 versus all other groups, †P < 0.01 versus all vehicle-control–treated groups and Sprouty 2 siRNA/propofol-treated group, (A-a) and (B): n = 3, A-b: n = 5. pAkt = phosphorylated (Ser 473) protein kinase B.