title: Transcriptional Factor PU.1 Regulates Decidual C1q Expression in Early Pregnancy in Human.
abstract: C1q is the first recognition subcomponent of the complement classical pathway, which in addition to being synthesized in the liver, is also expressed by macrophages and dendritic cells (DCs). Trophoblast invasion during early placentation results in accumulation of debris that triggers the complement system. Hence, both early and late components of the classical pathway are widely distributed in the placenta and decidua. In addition, C1q has recently been shown to significantly contribute to feto-maternal tolerance, trophoblast migration, and spiral artery remodeling, although the exact mechanism remains unknown. Pregnancy in mice, genetically deficient in C1q, mirrors symptoms similar to that of human preeclampsia. Thus, regulated complement activation has been proposed as an essential requirement for normal successful pregnancy. Little is known about the molecular pathways that regulate C1q expression in pregnancy. PU.1, an Ets-family transcription factor, is required for the development of hematopoietic myeloid lineage immune cells, and its expression is tissue-specific. Recently, PU.1 has been shown to regulate C1q gene expression in DCs and macrophages. Here, we have examined if PU.1 transcription factor regulates decidual C1q expression. We used immune-histochemical analysis, PCR, and immunostaining to localize and study the gene expression of PU.1 transcription factor in early human decidua. PU.1 was highly expressed at gene and protein level in early human decidual cells including trophoblast and stromal cells. Surprisingly, nuclear as well as cytoplasmic PU.1 expression was observed. Decidual cells with predominantly nuclear PU.1 expression had higher C1q expression. It is likely that nuclear and cytoplasmic PU.1 localization has a role to play in early pregnancy via regulating C1q expression in the decidua during implantation.
authors.affiliation: Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore , Singapore , Singapore ; Centre for Biotechnology and Bioinformatics, School of Life Sciences, Jawaharlal Nehru Institute for Advanced Studies , Secunderabad , India.
authors.forename: Shanmuga Priyaa
authors.initials: SP
authors.lastname: Madhukaran
authors.affiliation: Centre for Infection, Immunity and Disease Mechanisms, College of Health and Life Sciences, Brunel University London , Uxbridge , UK.
authors.forename: Uday
authors.initials: U
authors.lastname: Kishore
authors.affiliation: Centre for Biotechnology and Bioinformatics, School of Life Sciences, Jawaharlal Nehru Institute for Advanced Studies , Secunderabad , India.
authors.forename: Kaiser
authors.initials: K
authors.lastname: Jamil
authors.affiliation: Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore , Singapore , Singapore.
authors.forename: Boon Heng Dennis
authors.initials: BH
authors.lastname: Teo
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System , Singapore , Singapore.
authors.forename: Mahesh
authors.initials: M
authors.lastname: Choolani
authors.affiliation: Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore , Singapore , Singapore.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Lu
keywords: C1q; decidua; implantation; pregnancy; stromal cells; transcription factor; trophoblast