Expression of colony-stimulating factors and inflammatory cytokines in the uterus of CD1 mice during Days 1 to 3 of pregnancy

Abstract

Morphological and immunohistochemical analyses have documented the development of an acute inflammatory response, marked by the early appearance of granulocytes and later infiltration of mononuclear cells, in the uterus immediately after mating in mice. The response peaked on Day 1 and subsided by Day 3. In the present study, RNAs for macrophage colony-stimulating factor (CSF-1) and granulocyte-macrophage colony-stimulating factor (GM-CSF) and for interleukin 1α (IL-1α), IL-1β, interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α) were detected in uterine tissue on Day 1. With the exception of IL-6, which was higher on Day 3 than on Day 1, and IL-1α, which was not reduced on Day 2, concentrations of cytokine mRNA decreased to Day 3. No bioactivity was detected for GM-CSF, granulocyte colony-stimulating factor or IL-3, but CSF-1, IL-1, IL-6 and TNF-α were detected on Day 1 using bioassays. Changes in concentrations approximately paralleled those for mRNA. The concentrations of mRNA for CSF-1, IL-1, IL-6 and TNF-α were higher on Day 1 of pregnancy than in the uteri of cycling mice 24h earlier. The data are consistent with previous morphological observations demonstrating the expression of an acute inflammatory response in the mouse uterus after mating. Further, the data demonstrate the expression of genes for CSF-1, GM-CSF, IL-1α, IL-Iβ, IL-6 and TNF-α is induced in the uterus during mating.