Figure 2.

Serum and tissue glycosaminoglycan levels of MPS IVA mice after a single administration of thermostable keratanase. MPS IVA mice at 8 weeks of age were treated with 2 U/kg of thermostable keratanase intravenously, and PBS was administered in the untreated group. Serum samples were collected from the superficial temporal vein at the time points of 8, 9, 10, 11, 12, and 16 weeks of age. The level of mono-sulfated KS (A) and diHS-0S (B) was measured by LC-MS/MS; n = 4–5. The tissue sample was collected from MPS IVA mice 24 h post-injection of thermostable keratanase, and the levels of mono-sulfated KS in liver (C) and spleen (D) were measured by LC-MS/MS; n = 4. Statistics were analyzed by unpaired t-test. Data are presented as mean ± SD. * p < 0.05 vs. untreated MPS IVA. HS: heparan sulfate, KS: keratan sulfate, TSK: thermostable keratanase.