Figure 4

CHI3L1 mRNA in neurological diseases. Six-micrometer-thick paraffin-embedded sections from SIV encephalitis, SIV without encephalitis, AD, ALS, MS, Pick's disease, infarct and schizophrenia cases were hybridized with ³⁵S-labeled RNA probe for CHI3L1 as described in Methods, scale bar = 100 μm (A). CHI3L1 ISH co-localized with GFAP in AD, scale bar = 20 μm (B) and brain infarction, scale bar = 50 μm (D). Higher magnification show co-localization in a single cell, scale bar = 10 μm (E). The panels to the right and on the top depict reconstructions from a confocal z-stack in xz and yz direction to confirm that CHI3L1 (green) co-localizes with GFAP (red) staining as seen in yellow (F). Five random fields from each case were captured by confocal microscopy and analyzed for CHI3L1 and GFAP pixels per field (C). Linear regression showed a positive correlation between CHI3L1 pixel count and GFAP pixel count (r² = 0.5637; black circle SIVE, white circle SIV, black star MS, white triangle infarct, black diamond ALS, crossed square AD, gray circle Pick's disease, white circle Schizophrenia).