Measuring the endogenous expression of neprilysin and insulin-degrading enzyme (IDE)—proteases involved in Aβ degradation—in human neuroblastoma SH-SY5Y cells, the expression of neprilysin was reduced by CM from HBMVECs with H/R treatment or with Sirt1 siRNA transfection (Fig. 5a). The gene discussed is MME; the disease is neuroblastoma.