Increased synthesis and accumulation of heat shock 70 proteins in Alzheimer's disease.

Postmortem cortical tissues from Alzheimer's disease cases were found to contain significantly higher levels of the heat shock proteins hsp 72 and hsp 73 than control cortical tissues. This elevation was associated with the disease pathology in that it was not observed in Alzheimer's disease cerebella and was not correlated with perimortem characteristics such as age or cause of death of the patient or postmortem interval of the brain tissue. Examination of polysome translation products on two dimensional gels and by immunoprecipitation indicated that the syntheses of hsp 72/73 were increased in Alzheimer's disease tissues. In addition, immunoprecipitation of newly synthesized hsp 72 showed that numerous other nascent polypeptides were co-precipitated, which indicates an irreversible cotranslational association with the hsp 72. These results indicate that induction of specific heat shock proteins is associated with Alzheimer's disease and that cotranslational processes are affected by this induction.