Skip to main content
. Author manuscript; available in PMC: 2022 Jan 27.
Published in final edited form as: Nat Neurosci. 2020 Dec 16;24(3):368–378. doi: 10.1038/s41593-020-00771-8

Figure 4. WGA treatment enhances I-S1 uptake by brain, lung, spleen, and kidney and heparin blocks uptake by liver.

Figure 4.

Panels a-f show serum levels and tissue uptake of radioiodinated S1 from either RayBiotech or AMSBIO 10 min after intravenous injection in which WGA, a stimulator of adsorptive transcytosis, was included in the injections to half the mice. a. Serum I-S1 levels expressed as the percent of the injected dose per ml of serum. There was a main effect of S1 source (F (1, 25) = 49.79, p<0.0001) and treatment (F (1, 25) = 20.57, p<0.0001), as well as a significant effect of their interaction (F (1, 25) = 40.93, p<0.0001). WGA treatment decreased I-S1 (RayBiotech) levels in serum (p<0.0001), indicating increased clearance from blood. b. Brain I-S1 levels expressed as delta brain/serum ratios, showing significant effects (all p<0.0001) of S1 source (F (1, 25) = 92.98), treatment (F (1, 25) = 252.2), and their interaction (F (1, 25) = 91.41). These results show that WGA stimulated I-S1 uptake from both RayBiotech and AMSBIO and that WGA stimulated uptake of S1 from AMSBIO more than from RayBiotech. c. Lung I-S1 levels show an effect of treatment (F (1, 25) = 204.6, p<0.0001). d. Spleen I-S1 levels show effects of S1 source (F (1, 25) = 43.06, p<0.0001) and treatment (F (1, 25) = 30.42, p<0.0001), and a trend for interaction (F (1, 25) = 3.657, p = 0.08). e. Kidney I-S1 levels show effects of source (F (1, 25) = 33.45, P<0.0001) and treatment (F (1, 25) = 40.77, p<0.0001). f. Liver I-S1 levels show effects of source of S1 (F (1, 25) = 55.87), treatment (F (1, 25) = 52.16) and their interaction (F (1, 25) = 32.08), all at p<0.0001. For a-f data were analyzed using two-way ANOVA with S1 source (RayBiotech vs AMSBIO) and treatment (with or without WGA) as main factors, followed by Tukey’s multiple comparisons tests; figures show mean and standard deviation. *p<0.05, **p<0.01, and ***p<0.001 indicating comparisons of treatments within I-S1 group (RayBiotech or AMSBIO); #p<0.05, ##p<0.01, ###p<0.001 indicating comparisons of I-S1 groups within treatments. N = 7/group, except for Raybio S1-WGA mice (n-=8).

Panels g-h show serum levels and liver uptake of radioiodinated S1 from RayBiotech 10 min after intravenous injection with or without co-injection of WGA, heparin or both. g. Heparin increased serum levels of I-S1 (p = 0.016), but did not block the effect of WGA on I-S1 serum levels. h. In comparison to vehicle, uptake of I-S1 was decreased by heparin (p = 0.0015), WGA (p<0.0001), and WGA + heparin (p<0.001). Liver uptake of I-S1 was lower after WGA + heparin vs heparin alone (p = 0.0034) but not vs WGA alone. *p<0.05, **<0.01, ***<0.001. For g-h, data were analyzed by one-way ANOVA and Sidak’s multiple comparisons test, and n=10 for each group, with the exception of liver vehicle in panel h, where one outlier was identified using a Grubbs test (77.6 ul/g) and excluded, leaving n=9 mice.