Roles of the mitogen-activated protein kinase family in macrophage responses to colony stimulating factor-1 addition and withdrawal

Abstract

Colony stimulating factor-1 (CSF-1) (or macrophage CSF) is involved in the survival, proliferation, differentiation, and activation of cells of the monocyte/macrophage lineage. Because the mitogen-activated protein kinase family members extracellular signal-regulated kinases (ERKs), p38, and c-Jun N-terminal kinase are widely implicated in such cellular functions, we measured their activity in growing and growth-arrested cultures of bone marrow-derived macrophages (BMM), as well as their stimulation by saturating concentrations of CSF-1. ERK activity was approximately 2-fold higher in cycling BMM compared with growth-arrested BMM; in addition, CSF-1-stimulated BMM DNA synthesis was partially..