Fig. 4.

LMP7 is activated in the peripheral nerve axons of C57SOD1^G93A mice and ALS patients. a, b LMP7 immunoreactivity (green) is strikingly upregulated in the sciatic nerve of the C57SOD1^G93A mice at the disease onset (G93A) compared to the Ntg littermates (NTG); scale bar, 100 μm. c–e Representative co-localization of LMP7 with SMI-31 (axonal marker; red) in the sciatic nerve of C57SOD1^G93A mice; scale bar, 20 μm. f–i MHCI (green), LMP7 (red), and SMI-31 (blue) co-localization in the sciatic nerve of C57SOD1^G93A mice, highlighting MHCI-LMP7 co-immunoreactivity in motor axons with vacuoles typical of Wallerian degeneration. j–n Transverse section of an obturator nerve biopsy from a sporadic ALS patient (ALSP) and control (CTRL), showing a marked LMP7 activation (green) in ALS patient; DAPI: blue; scale bar, 50 μm; scale bar, 150 μm. o–r Longitudinal section of the obturator nerve biopsy from an ALS patient, showing LMP7 (green) co-localization with neurofilaments (red); scale bar: 50 μm; s–v LMP7 is expressed by terminal motor axons but not at the NMJ of C57SOD1G93A mice; LMP7 (green), α-BTX (red), and MHCI (blue); scale bar, 50 μm