The properties of heat shock proteins (HSPs) and especially HSP70 draw attention for a number of reasons. HSP70 is an endogenous intracellular protein that has a variety of functions. HSP70 protects cells from cell death induced by various noxious stimuli and inhibits various cellular death pathways, decreases the infarction area after ischemia, (Klettner, 2004), and significantly increases the lifespan in drosophila and nematodes. A similar effect of HSP70 in mammals has not been described so far. However it has been shown both that an HSP70 level decreases with age in olfactory receptor neurons of older subjects (Getchell et al., 1995) and that higher HSP70 levels were detected in long-living humans.
Here we show that a long-term intranasal injection of human recombinant HSP70 (2 µg/animal) significantly increases a life span in NMRI old males (1000 ± 41 days) whereas this effect was not found in females (793 ± 19 days) as compared to a life span of control males (839 ± 48). These results indicate HSP70 efficiency as a means for life extension in mice. The availability of highly purified human HSP70 and its efficacy in low doses that reduces a possibility of detrimental side effects let assume that HSP70 may appear an effective medical preparation for human life extension.