The age-related changes in DNA binding activity of AP-1, NF-κB, and OCT-1 transcription factors in lymphocytes from rats

Abstract

The effect of aging on the induction of the ubiquitous transcription factors AP-1, NF-κB, and OCT-1 by concanavalin A (conA) was studied in nuclear extracts from spleen lymphocytes isolated from young (6 mo) and old (24 mo) male Fischer 344 rats. The induction of AP-1, NF-κB, and OCt-1 DNA binding activities were significantly lower (35 to 60%) in nuclear extracts from spleen lymphocytes isolated from old rats compared to nuclear extracts from spleen lymphocytes isolated from young rats. Because the transcription factor AP-1 consists of heterodimers of Fos and Jun oncoproteins, the induction of c-fos and c-jun expression (mRNA levels) by conA stimulated lymphocytes was measured using 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 arise from alterations in c-fos expression.