Aberrant TLR-mediated signal transduction in macrophages from aged mice

Previously, we have reported that macrophages (M Phi s) from aged mice produce lower levels of cytokines than cells from young mice. Here, we examined Toll-like receptor (TLR) signaling pathways in murine M Phi s. LPS-and zymosan-stimulated production of TNF alpha and IL-6 was lower in M Phi s from aged mice when compared to young. These age-related changes were associated with lower activation of p38 MAPK and reduced expression of p38, but not MAPK-APK-2. These data suggest that decreased MAPK expression could be a mechanism responsible for the age-related deterioration of MFs function.