Description
Uterine macrophages are thought to play an important regulatory role at the maternal-fetal interface. We report here a unique gene expression pattern intrinsic of first trimester decidual monocytes/macrophages, but not of their blood counterparts. The micro-array data comprises approximately 14,000 genes. Some of the key findings were confirmed by real time PCR or secreted protein measurements. A large number of regulated genes were found to be functionally related to immunomodulation and tissue remodelling, corroborating polarization patterns of differentiated macrophages of M2 phenotype. These include M2 markers such as CCL-18, CD209, insulin-like growth factor (IGF)-1, mannose receptor c type (MRC)-1 and fibronectin-1. Further, the selective up-regulation of triggering receptor expressed on myeloid cells (TREM)-2, alpha-2-macroglobulin (A2M) and prostaglandin D2 synthase (PGDS) provides new insights into the regulatory function of decidual macrophages in pregnancy. In addition, a large number of regulated genes in the micro-array analysis were related to cell cycle regulation. Taken together, molecular characterization of decidual macrophages presents a unique transcriptional profile replete with important components for fetal immunoprotection.