Figure 1.

MPS I clone information and functional activity of IDUA and validation of GAG accumulation. (A) The three MPS I patient fibroblasts that were used to generate corresponding iPSC patient lines and clones employed for further studies. (B) IDUA activity in cell lysates from patient-derived NSCs in the presence of serum. For lysates, the nmoles of 4-MU were normalized to a 7-h reaction and equal protein concentrations. Released 4-MU was measured fluorometrically and plotted against a calibration standard. NSCs derived from distinct MPS I subgroups demonstrate varying enzymatic deficiency of IDUA. (C) Immunoblot analysis of MPS I-NSC lysates. The polyclonal IDUA antibody identified a 76 kDa band in control and Scheie lysates but severely reduced protein expression in H/S and H lysates. (D) Quantitative GAG assays to measure overall elevation of GAG in MPS I NSCs. Equal protein concentration was applied in GAG-DMMB assay. Measurements of GAGs plotted against a standard curve prepared using bovine tracheal chondroitin 4-sulfate as a control showed significant increase in GAGs of Hurler cells compared to wild type.