Table 1.
Summary of Clinical and Demographic Values from FRDA Patients at the Children’s Hospital of Philadelphia (Cohort 1).
Figure 1.
Frataxin protein and mRNA level is stable from day-to-day in whole blood.
(A) Frataxin protein levels measured by dipstick assay in FRDA patient subjects over the course of 4 weeks (Cohort 1; n = 31). (B) Frataxin protein levels measured by dipstick assay in whole blood collected from 5 FRDA patients (red) and 5 related carriers (blue) weekly for 15 weeks (Cohort 2). (C) Frataxin mRNA levels measured by RT-qPCR in blood collected in PAXgene tubes from Cohort 2. Frataxin mRNA level is expressed relative to control donor levels and is normalized to the endogenous control gene GAPDH.
Figure 2.
Frataxin protein and mRNA levels strongly correlated when measured in different cellular compartments (Cohort 3).
(A) Frataxin mRNA in PBMCs and whole blood (R2 = 0.84, p<0.0001). (B) Frataxin protein in PBMCs and whole blood (R2 = 0.63, p<0.0001). (C) Frataxin mRNA and protein in whole blood (R2 = 0.55, p<0.0001). (D) Frataxin mRNA and protein in PBMCs (R2 = 0.58, p<0.0001). (E) Frataxin protein in PBMCs and cheek swabs (R2 = 0.67, p<0.0001). (F) Frataxin protein in whole blood and cheek swabs (R2 = 0.58, p<0.0001). Frataxin mRNA level in PBMCs and whole blood is expressed relative to control donor levels and is normalized to the endogenous control gene GAPDH.
Figure 3.
Effect of HDAC inhibitor RG2833 on frataxin level in PBMCs (Cohort 3).
(A) The effect of RG2833 on frataxin mRNA level relative to vehicle control in PBMCs following 48 hour treatment (n = 49 at 1, 2.5, 5, and 10 µM; n = 2 at 0.1 and 0.5 µM). The relative quantity of frataxin mRNA in HDACi–treated PBMCs is normalized to cell number and RNA input. (B) The effect of RG2833 on FXN protein level relative to vehicle control in PBMCs following 72 hour treatment (n = 27). (C) The fold-change increase in FXN mRNA in PBMC in response to HDACi does not correlate with repeat length (GAA1, R2 = 0.015, p = 0.451). (D) The fold-change increase in FXN protein in response to HDACi does not correlate with repeat length (GAA1, R2 = 0.006, p = 0.686).
Table 2.
Response Rate for RG2833 in PBMC Isolated From FRDA Patients in Cohort 3 and Treated Ex Vivo.
Table 3.
Summary of Clinical Information and FRDA Disease Parameters by Frataxin Quartile.