Stress-induced phosphorylation of c-Jun-N therminal kinases and nuclear translocation of HSP70 in the Wistar rat hippocampus

We followed both JNKs (c-Jun-N-therminal kinases) and Hsp70 signals in the cytoplasmic and nuclear compartments of the hippocampus of Wistar male rats exposed to acute, chronic, and combined stress. The activity of JNK1 was decreased in both compartments by all three types of stress, while the activity of cytoplasmic JNK2/3 was elevated in acute and unaltered or lowered in chronic and combined stress. Under all stress conditions, Hsp70 translocation to the nucleus was markendly increased. The results suggest that neurodegenerative signaling of JNKs may be counteracted by increase of nuclear Hsp70, especially under chronic stress.