THE AGE-RELATED-CHANGES IN DNA-BINDING ACTIVITY OF AP-1, NF-KAPPA-B, AND OCT-1 TRANSCRIPTION FACTORS IN LYMPHOCYTES FROM RATS

The effect of aging on the induction of the ubiquitous transcription f actors AP-1, NF-kappa B, and OCT-1 by concanavalin A (conA) was studie d in nuclear extracts from spleen lymphocytes isolated from young (6 m o) and old (24 mo) male Fischer 344 rats. The induction of AP-1, NF-ka ppa B, and OCt-1 DNA binding activities were significantly lower (35 t o 60%) in nuclear extracts from spleen lymphocytes isolated from old r ats compared to nuclear extracts from spleen lymphocytes isolated from young rats. Because the transcription factor AP-1 consists of heterod imers of Fos and Jun oncoproteins, the induction of c-fos and c-jun ex pression (mRNA levels) by conA stimulated lymphocytes was measured usi ng northern blot analysis. ConA induction of c-fos mRNA but not c-jun mRNA decreased approximately 70% with age. Therefore, the age-related decrease in the induction of AP-1 transcription factor appears to aris e from alterations in c-fos expression.