Fig. 5

BRCA1 is Upregulated in Human ALS Brain. a BRCA1 antibody validation by western blotting after siRNA knockdown in the human cortical neuron cell line HCN1. Ponceau staining of membrane shows protein loading. b Western blot for BRCA1 in motor cortex homogenates of ALS and age-match controls. Ponceau staining of membrane shows protein loading. Graph shows quantification of BRCA1 immunoreactivity in (n = 8) and ALS (n = 12) cases. Values are mean ± SD. *p < 0.01. c Immunohistochemical staining for BRCA1 (brown, cresyl violet counterstained) in aged control motor cortex. Betz cells (open arrows) are rich in Nissl substance (blue, cresyl violet counterstaining) and have low BRCA1 immunoreactivity (brown). d Immunohistochemical staining for BRCA1 in ALS motor cortex. Betz cells (open arrows) are enriched in BRCA1 immunoreactivity (brown, cresyl violet counterstaining). e In ALS motor cortex layer five pre-attritional pyramidal neurons with distinct Nissl bodies (blue, cresyl violet counterstaining), BRCA1 immunoreactivity (brown) was localized in large cytoplasmic inclusions and was present only faintly in the nucleus (asterisk). f In layer five attritional pyramidal neurons in ALS motor cortex, Nissl substance was dispersed and attenuated (blue, cresyl violet counterstaining) and BRCA1 immunoreactivity (brown) was enriched in the nucleus (asterisk) and cytoplasm. g In aged control spinal cord dorsolateral funiculus corticospinal tract, BRCA1 immunoreactivity (brown) was very sparse. h In ALS spinal cord corticospinal tract (laterodorsal funiculus), numerous large axonal swellings (hatched arrows) positive for BRCA1 were present. Inset shows a BRCA1-positive axonal swelling (hatched arrow) and a negative profile (solid arrow). Scale bars (in μm) = 60 (A, same for B), 8 (E), 4 (F), 5 (G, same for H), 1.5 (H inset)