FIGURE 6.

EZH2 inhibition corrects electrophysiological abnormalities in cultured FXS neurons and reactivates FMR1 expression in human FXS NPCs engrafted within the brains of mice. (A) MEA showing firing frequency of FXS 848-neurons expressing an EZH2 shRNA or treated with EPZ6438. The firing frequency of normal neurons is shown as a control. (B) qRT-PCR analysis monitoring FMR1 expression in cultured FXS 848-neurons treated with a control or EZH2 ASO. qRT-PCR analysis monitoring expression of REST (C) or DCC, ROBO3, and SLIT1. (D) in cultured FXS 848-neurons treated with an EZH2 ASO. (E) Immunoblot analysis showing DGKK levels in cultured FXS 848-neurons treated with an EZH2 ASO. The DGKK signal was quantified relative to that obtained in normal neurons. (F) MEA showing firing frequency of cultured FXS 848-neurons treated with an EZH2 ASO. The firing frequency of normal neurons is shown. (G) qRT-PCR analysis monitoring FMR1 expression in FXS 848-NPC grafts in mice (n = 4) treated with an EZH2 or control ASO by ICV injection. (H) Representative immunohistochemical images of mouse brain sections (subventricular zone) showing staining for human FMRP (green), human mitochondria (red) and DAPI (blue, total cells from both mouse and human) following treatment with an EZH2 or control ASO. The merged image is shown. Data are generally represented as mean ± SD (n = 3 biological replicates), with the exception of (G), for which n = 4 biological replicates). *P < 0.05, **P < 0.01.