Fig. 3.

In MPN patients, the proteasome levels are markedly increased in granulocytes and platelet lysates, while immunofluorescence for UPS reveals PaCSs-like structures in BM cells of MPN patients. a Accumulation of PaCSs in MPN granulocytes and platelets was associated with markedly increased levels of 20S proteasome in cell lysates. Representative example of Western blot analysis of the 20S proteasome in blood granulocytes and platelet lysates from two healthy subjects (HS) or from patient 3, affected by CML, or patient 8, affected by PV. Granulocyte and platelet lysates were separated on a 12 % SDS/polyacrylamide gel and transferred to nitrocellulose. Membranes were probed with an antibody against 20S proteasome (α6 subunit). Beta-actin was used as equal loading control. b Confocal microscopy after immunofluorescence staining for 20S proteasome identifies several cytoplasmic areas with strong 20S signal (green) in the BM biopsy of a CML patient; background BM structure is recognized by phase-contrast microscopy. b1, b2 Two sections from the same specimen show 20S proteasome (b1) and polyubiquitinated proteins (b2) immunoreactive cytoplasmic areas in CML cells under confocal microscopy; note in b1 several 20S-positive cell blebs (arrowheads) and cell detached vesicles (arrows)