Fig. 8
From: Ultrastructural and dynamic studies of the endosomal compartment in Down syndrome
Endocytosis and recycling of transferrin receptors in fibroblasts from individuals with DS and euploid controls. a Quantification of 4 min endocytosis of transferrin-Alexa Fluor 647 in fibroblasts from 3 euploid individuals and 3 individuals with DS. Mean fluorescence intensity of transferrin is not significantly different between 2 N fibroblasts (n = 3 individuals, mean fluorescence intensity = 3970, SEM ± 283.3) and fibroblasts from individuals with DS (n = 3 individuals, mean fluorescence intensity = 4248, SEM ± 405.5) (three independent experiments each including all individuals) (Mann-Whitney test, p-value = 0.53); b Representative z-projected stack images of transferrin receptors recycled to the cell surface (red) and DAPI (blue) in euploid fibroblasts and fibroblasts from individuals with DS; c Quantification of fluorescence intensity of the transferrin receptor surface staining after 15 min of transferrin recycling shows a significant increase in the mean fluorescence intensity in DS fibroblasts as compared to euploid fibroblasts (mixed effects ANOVA, genotype *p-value = 0.012) (two independent experiments each including all individuals); d Quantification of fluorescence intensity of the transferrin receptor surface staining in cultured untreated fibroblasts from euploid fibroblasts and fibroblasts from individuals with DS shows no significant difference between genotypes (mixed effects ANOVA, genotype p-value = 0.67)