Stathmin (p19), a 19-kDa cytosolic phosphoprotein, plays a key role in
converting extracellular signals into intracellular biochemical chang
es. Antibodies and cDNA specific for stathmin were used to study its l
evels and localization in normal and Alzheimer's disease (AD) brain ti
ssue. The stathmin protein concentration was reduced in AD neocortex a
s assessed by Western blotting, whereas the concentration of its mRNA
detected by both in situ hybridization and slot blot were increased in
AD. The alteration of the stathmin protein concentration was negative
ly correlated with neurofibrillary tangle numbers but not with plaque
numbers. Immunoreactivity was evenly localized to the cytoplasm of neu
rons in control cortical sections, whereas in AD it was preferentially
localized to some of the neurofibrillary tangle-bearing neurons. Numb
ers of stathmin-positive neurons were inversely correlated with tangle
numbers but not with plaque numbers in the frontal cortex of AD patie
nts.