Activator protein 1-mediated expression of monocyte chemoattractant protein 1 in cultured rat luteal cells.

We have proposed that luteal cells undergo apoptosis-dependent phagocytosis by invading monocyte-derived macrophages in regressive corpora lutea of the rat. Accumulation of monocytes/macrophages seems to be mediated by monocyte chemoattractant protein 1 (MCP-1) or CCL2, because apoptosis and the production of MCP-1 mRNA occur simultaneously, but in different luteal cells, in a manner dependent on nuclear factor kappaB (NF-kappaB). In this study, we determined the mechanisms underlying the induction of these two events using primary cultures of rat luteal cells.