A femtomolar-acting neuroprotective peptide induces increased levels of heat shock protein 60 in rat cortical neurons: a potential neuroprotective mechanism.

Activity-dependent neurotrophic factor (ADNF) was recently isolated from conditioned media of astrocytes stimulated with vasoactive intestinal peptide (VIP). ADNF provided neuroprotection at femtomolar concentration against a wide variety of toxic insults. A nine amino acid peptide (ADNF-9) captured with even greater potency the neuroprotective activity exhibited by the parent protein. Utilizing Northern and Western blot analyses, it was now shown that ADNF-9 increased the expression of heat shock protein 60 (hsp60) in rat cerebral cortical cultures. In contrast, treatment with the Alzheimer's toxin, the beta-amyloid peptide, reduced the amount of intracellular hsp60. Treatment with ADNF-9 prevented the reduction in hsp60 produced by the beta-amyloid peptide. The protection against the beta-amyloid peptide-associated cell death provided by ADNF-9 may be mediated in part by intracellular increases in hsp60.