Fig. 3

YKL-40 expression in experimental models of prion diseases. a RT-qPCR analysis of YKL-40 in the cortex of control and sCJD MM1 inoculated tg340PRNP129MM mice at 120 dpi (pre-clinical), 160 dpi (early clinical), 180 dpi (clinical) and 210 dpi (clinical with 10–1 diluted inoculum). Four animals per group were analyzed. Normalization was performed using Hprt. b Representative Western-blot analyses for YKL-40 immunodetection in the cortex of control and sCJD MM1-inoculated tg340PRNP129MM mice at 120 dpi (pre-clinical) and 180 dpi (clinical). Three animals per group were analyzed. Normalization was based on β-actin levels. Numbers indicate densitometry results from three animals per group. Unpaired t-tests were performed to determine statistical differences. c RT-qPCR analysis of YKL-40 in the whole brain of control and RML scrapie-infected mice at pre-clinical (120 dpi) and clinical disease (180 dpi) stages. GAPDH was used for normalization. Similar results were acquired when normalization was based on Hprt expression levels (not shown). Unpaired t-tests were used for estimation of statistical differences. d Immunohistochemical analysis of YKL-40 expression in the cerebral cortex, hippocampus and thalamus of control and RML scrapie-infected mice at pre-clinical (60 and 90 dpi) and clinical (150 dpi) disease stages. Scale bar = 50 μm. Arrows indicate YKL-40 positive reactive astrocytes. Three animals per time point were used. Two sections were stained per animal (sagittal and coronal sections were used). Brown staining corresponds to YKL-40 staining and light blue to haematoxylin counterstaining. e RT-qPCR analysis of YKL-40 in the cerebral cortex of control and 22 L scrapie-infected mice at pre-clinical (60 dpi) and clinical (140 dpi) disease stages. f RT-qPCR analysis of YKL-40 in the cerebellum of control and 22 L scrapie-infected mice at clinical (140 dpi) disease stages. In all cases GAPDH was used for normalization. Similar results were obtained when Hprt was used for normalization (not shown). Unpaired t-tests were used to determine statistical differences. g Western blot analysis of Vimentin and GFAP in control and 22 L–scrapie infected COCS. β-actin was used for normalization. Graphic representation of densitometry analysis of five cerebellar tissues per condition is shown. Statistical differences were determined with unpaired t-tests. h RT-QuIC analysis of control and 22 L–scrapie infected COCS. A representative graph of three cerebellar tissues per condition is shown. All control tissues were tested negative, while all 22 L–infected tissues were tested positive (left panel); western-blot showing the presence of PrPres in 22 L–infected cells (right panel). i ELISA analysis of YKL-40 levels in control and 22 L–scrapie infected COCS. Statistical differences were determined with unpaired t-tests. Fold changes in the expression of mRNA and protein were determined relative to the control cases. *p < 0.05, **p < 0.01, ***p < 0.001