Immunohistochemical staining for lysosomes within capillary endothelium in hippocampus of MPS III patients. Similar to immunoexpression of lysosomes in control putamen capillaries, almost no capillary LAMP-1 expression (green) was distinguished in control hippocampus (A, D, arrows). Normal appearance of morphologically determined neural cells with nuclei centered within cell bodies and some lysosomal expression was demonstrated. In MPS III A (B, C) and III D (E), intensive lysosomal LAMP-1 expression was found in numerous capillaries in hippocampus with visible swelling of ECs. (B, C, E) Severe LAMP-1 immunoreactivity (green, arrows) in numerous neural cells with translocation of nuclei was observed. Arrows and arrowheads indicate LAMP-1 (green) and collagen IV (red) immunoexpressions, respectively. Magnification in A-E is 40x. (F) Semi-quantitative analysis of LAMP-1 immunoreactivity showed high lysosomal marker expressions within capillary endothelium in MPS III A and III D hippocampus vs. controls.