Figure 1: Effects of IFG on GCase activity and trafficking in primary N370S GCase fibroblasts.

(a) Schematic of the reaction performed by GCase and the chemical structure of IFG. (b) Inhibition curve for IFG with imiglucerase. Error bars are s.d. (c) Dose response for N370S GCase fibroblasts treated with IFG for 5 d, reported as arbitrary fluorescence units (F460) per microgram of protein per hour. We compared values from lysates of IFG-treated cells to those of untreated control cells using a two-tailed Student's t-test assuming equal variances. ^*P < 0.05. Error bars are s.e.m. (d) Fluorescence intensities (grayscale) from untreated and IFG-treated wild-type (WT) and N370S GCase primary fibroblasts labeled with anti-GCase (top panels; scale bar 53 μm for all top panels) and dual labeling of fibroblasts with antibodies against GCase (green) and the lysosomal marker Lamp1 (red). Overlap (yellow) indicates colocalization of GCase and Lamp1 (bottom panels; scale bars from left to right are 30 μm, 26 μm, 53 μm and 53 μm). Proliferation of Lamp1-positive structures evident here in N370S fibroblasts has been previously observed in cells from GD-afflicted individuals³⁰. (e) Comparison of IFG and CBE treatment on GCase localization in the lysosomes in primary fibroblasts. Immunofluorescence of IFG (100 μM; 5 d) or CBE (100 μM; 5 d) treated and untreated wild-type and GCase N370S fibroblasts with anti-GCase (green) and Lamp1 (red). Overlap (yellow) indicates colocalization of GCase and Lamp1. Scale bars from left to right are 27 μm, 26 μm, 30 μm and 53 μm.