Overexpression of hsp70i facilitates reactivation of intracellular proteins in neurones and protects them from denaturing stress.

Transfection of neurones with an adenoviral vector (Ad) expressing high levels of hsp70i was shown to protect primary hippocampal cultures from heat stress. To investigate one of the molecular mechanisms which may underlie hsp70i's neuroprotective effects we measured luciferase activity in the presence and absence of hsp70i following heat or chemical inactivation. Luciferase activity was recovered to 80% of control levels in the presence of recombinant hsp70i in vitro. Luciferase activity was also maintained in primary hippocampal neurones exposed to a denaturing stress if transfected with Ad-hsp70i. These results support the hypothesis that hsp70i protects neurones from stress by interacting with cytosolic proteins and thereby protecting them from inactivation.