Hs chi3l1

Human postmortem brain tissue were supplied by the UK Multiple Sclerosis Tissue Bank (UK Multicentre Research Ethics Committee, MREC/02/2/39), funded by the Multiple Sclerosis Society of Great Britain and Northern Ireland (registered charity 207,495). Fresh-frozen blocks containing chronic active lesion from progressive MS patients were sectioned (10-μm), PFA-fixed, blocked in PBS with 10% normal horse serum (NHS) and immunostained with rabbit CHI3L1 (monoclonal antibody) 1:200 (Abcam) followed by biotinylated secondary antibody (Jackson Immunoresearch Laboratories, Cambridgeshire, UK), avidin/biotin staining (Vector Laboratories, Burlingame, CA) and 3,3′-diaminobenzidine (DAB) staining (Vector Laboratories, Burlingame, CA). The RNAscope 2.5 Duplex Assay (ACD Biosystems) was performed according to the ACD protocol for fresh-frozen tissue. Chronic active lesions were hybridized with two mRNA probes per experiment. Hs-GFAP (Cat No. 311801) was used as the astrocyte marker together with Hs-CHI3L1 (Cat No. 408121). The probes were amplified according to manufacturer’s instructions and labeled with the following red or green color for each experiment. The Hs-CHI3L1 probe was also combined with immunohistochemistry (anti-GFAP and anti-MHCII, Abcam) as described above.