Figure 6: The normalized values of the extracellular Aβ42 levels in medium of cells transfected with the siRNA duplexes. Human fibroblasts expressing endogenously the wild type PSEN1 gene (CELMA) and L392V mutant (NOV4) were cultured in the presence of P10, P10-thio, and control nonsilencing siRNA duplexes (150 and 300 nM). After 48-hour incubation, the culturing medium was collected with 1 mM AEBSF, and the level of Aβ42 was measured by sandwich ELISA test. Data are presented as percentage values to control cells treated with lipofectamine only. The results are mean values from two independent experiments. Statistical analysis of differences between two groups of data (Wt-PSEN1 versus Mut-PSEN1) were calculated by the use of Student’s t-test (data with normal distribution). All differences were considered as statistically significant.