Louie Ye1, Amy Gratton1, Natalie J Hannan1, Ping Cannon1, Minh Deo1, Kirsten R Palmer2, Stephen Tong1, Tu'uhevaha J Kaitu'u-Lino3, Fiona C Brownfoot1. 1. Translational Obstetrics Group, The Department of Obstetrics and Gynaecology, Mercy Hospital for Women, University of Melbourne, 163 Studley Rd, Heidelberg, 3084, Victoria, Australia. 2. Department of Obstetrics and Gynaecology, Monash University, Monash Medical Centre, 246 Clayton Rd, Clayton, 3168, Victoria, Australia. 3. Translational Obstetrics Group, The Department of Obstetrics and Gynaecology, Mercy Hospital for Women, University of Melbourne, 163 Studley Rd, Heidelberg, 3084, Victoria, Australia. Electronic address: t.klino@unimelb.edu.au.
Abstract
INTRODUCTION: Preeclampsia is a serious complication affecting 5-8% of pregnancies. Central to its pathogenesis is placental hypoxia and inflammation which leads to secretion of soluble fms-like tyrosine kinase 1 (sFlt-1). sFlt-1 causes widespread endothelial dysfunction. The molecular mechanisms regulating sFlt-1 production remain poorly understood. Recently, a binding site for the nuclear factor activated T cells (NFAT) transcription factor has been found on fms-like tyrosine kinase 1 (FLT-1) promoter. METHODS: We assessed whether inhibiting NFAT impacts FLT-1, sFlt-1 and cytokine expression, as well as sFlt-1 secretion in primary cytotrophoblasts, placental explants and human umbilical vein endothelial cells (HUVECs). We investigated whether NFAT is regulated by hypoxia in primary cytotrophoblasts. We characterised the expression of NFAT1-4 in preterm preeclamptic compared to gestationally matched placentas. RESULTS: Inhibiting NFAT reduced FLT-1 and sFlt-1 splice variant e15a transcription, concordant with reduced total sFlt-1 and sFlt-1 e15a secretion from primary human cytotrophoblasts. This effect appeared tissue specific as inhibiting NFAT did not change sFlt-1 secretion from endothelial cells. Inhibiting NFAT also reduced transcription of inflammatory cytokines IL-1β and IL-10 in primary cytotrophoblasts. NFAT1 and NFAT3 mRNA expression were significantly increased under hypoxia (1% O2). Inhibiting NFAT under hypoxia significantly reduced FLT-1 and sFlt-1 e15a transcription, but did not reduce sFlt-1 secretion. NFAT mRNA and protein localisation was not different in preeclamptic compared to gestationally matched placenta. DISCUSSION: NFAT positively regulates placental FLT-1 and sFlt-1 e15a, secretion of sFlt-1 and inflammatory cytokine expression. It may be involved in the pathophysiology of preeclampsia.
INTRODUCTION: Preeclampsia is a serious complication affecting 5-8% of pregnancies. Central to its pathogenesis is placental hypoxia and inflammation which leads to secretion of soluble fms-like tyrosine kinase 1 (sFlt-1). sFlt-1 causes widespread endothelial dysfunction. The molecular mechanisms regulating sFlt-1 production remain poorly understood. Recently, a binding site for the nuclear factor activated T cells (NFAT) transcription factor has been found on fms-like tyrosine kinase 1 (FLT-1) promoter. METHODS: We assessed whether inhibiting NFAT impacts FLT-1, sFlt-1 and cytokine expression, as well as sFlt-1 secretion in primary cytotrophoblasts, placental explants and human umbilical vein endothelial cells (HUVECs). We investigated whether NFAT is regulated by hypoxia in primary cytotrophoblasts. We characterised the expression of NFAT1-4 in preterm preeclamptic compared to gestationally matched placentas. RESULTS: Inhibiting NFAT reduced FLT-1 and sFlt-1 splice variant e15a transcription, concordant with reduced total sFlt-1 and sFlt-1 e15a secretion from primary human cytotrophoblasts. This effect appeared tissue specific as inhibiting NFAT did not change sFlt-1 secretion from endothelial cells. Inhibiting NFAT also reduced transcription of inflammatory cytokines IL-1β and IL-10 in primary cytotrophoblasts. NFAT1 and NFAT3 mRNA expression were significantly increased under hypoxia (1% O2). Inhibiting NFAT under hypoxia significantly reduced FLT-1 and sFlt-1 e15a transcription, but did not reduce sFlt-1 secretion. NFAT mRNA and protein localisation was not different in preeclamptic compared to gestationally matched placenta. DISCUSSION: NFAT positively regulates placental FLT-1 and sFlt-1 e15a, secretion of sFlt-1 and inflammatory cytokine expression. It may be involved in the pathophysiology of preeclampsia.
Authors: Theresa M Wewers; Annika Schulz; Ingo Nolte; Hermann Pavenstädt; Marcus Brand; Giovana S Di Marco Journal: J Am Soc Nephrol Date: 2021-06-21 Impact factor: 14.978