Figure 2.

Reduction of urinary GAGs in mice receiving low doses of gene therapy and/or monthly ERT. Urinary GAGs were measured in treated MPS VI mice (gray bars), in normal (NR, white bars) and affected (AF, black bars) controls. Urinary GAG levels measured were averaged for all animals within the same group of treatment and the resulting value is reported as a percentage (%) of age-matched AF controls, as indicated inside each bar. Results are represented as mean ± SE. Number (n) of animals is: NR, n = 39 at postnatal day 60 and 90, n = 34 at postnatal day 120, n = 31 at postnatal day 150, n = 26 at postnatal day 180 and n = 21 at postnatal day 210; AF, n = 9; ERT, n = 5 except for postnatal day 90, 150, and 180 (n = 4); AAV 2 × 10¹¹, n = 6; AAV 2 × 10¹¹ + ERT, n = 8 except for postnatal day 210 (n = 5); AAV 6 × 10¹¹, n = 5 except for postnatal day 210 (n = 4); AAV 6 × 10¹¹ + ERT, n = 5 except for postnatal day 210 (n = 3). The lower number of values in the later than earlier time points is due to either technical challenges in the collection of samples when too numerous or to animal sacrifice, which varied between days 180 and 210 of age. Statistical comparisons were made using the one-way analysis of variance (ANOVA) and the Tukey post hoc test. The P-value is: *< 0.05 and **< 0.01; the P-value of AF versus all groups is: °° << 0.01. The exact P-values obtained are indicated in the Material and Methods section. Abbreviations: AAV2/8.TBG.hARSB, vector which encodes human ARSB; AAV, adeno-associated viral vector; ARSB, arylsulfatase B;; ERT, monthly ERT; GAGs, glycosaminoglycans; hARSB, human ARSB; MPS, mucopolysaccharidoses; TBG, thyroxine-binding globulin.