ABSTRACT
Microcystin-leucine-arginine (MC-LR) is widespread in the water and food, which has suspected to be associated with adverse pregnancy outcomes. In the present study, we aim to assess the interaction between MC-LR exposure and preeclampsia development and elucidate the molecular events involved. After exposure to MC-LR during pregnancy, the mice developed hypertension and proteinuria, the typical symptoms of preeclampsia. This was associated with decreased invasiveness of placental trophoblast and vascular dysplasia caused by MC-LR through down-regulating VEGFA and TGF-ß expression via AKT/m-TOR/HIF-1α pathway. In addition, this conclusion has been confirmed in a case-control study. Significantly, the addition of Deferoxamine (DFM), a phosphorylated serine-threonine protein kinases (p-AKT) specific agonist, can antagonize the inhibitory effect of MC-LR on the expression of related proteins, which further ameliorate the migration and invasion ability of HTR-8/Svneo cells. To sum up, our study revealed the pathologic mechanism by which MC-LR lead to preeclampsia and emphasized the importance of pregnancy management.
Subject(s)
Pre-Eclampsia , Prenatal Exposure Delayed Effects , Animals , Female , Mice , Pregnancy , Case-Control Studies , Microcystins/toxicity , Placenta/metabolism , Pre-Eclampsia/chemically induced , Pre-Eclampsia/metabolism , Prenatal Exposure Delayed Effects/metabolism , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Vascular Endothelial Growth Factor A/metabolism , Transforming Growth Factor beta/antagonists & inhibitors , Transforming Growth Factor beta/metabolismABSTRACT
Microcystin-leucine-arginine (MC-LR) reduces the fertility of female mice, but the mechanism is unknown. We studied the effect of MC-LR on early pregnancy and elucidated its possible mechanism. The number of embryo beds and embryo volume decreased in pregnant mice at 6 or 8 days after fertilization after acute exposure to MC-LR. The corpus luteum secretes estrogen and progesterone, which are involved in embryo implantation and maintenance of early pregnancy. MC-LR exposure reduced luteal blood vessel branches and inhibited hormone synthesis. Functional blood vessels are essential to the maintenance of luteal structure and function. Reduced migration and tube-forming were also detected in human umbilical vascular endothelial cells (HUVECs) treated with MC-LR. MC-LR significantly decreased the expression of vascular endothelial growth factor receptor 2 (VEGFR2) in vivo and in vitro, which was responsible for the inhibited construction of the vascular network. The MEK/ERK/SP1 signal pathway mediated the decrease in VEGFR2 expression, and the agonists of phosphorylated extracellular regulated protein kinases (p-ERK) alleviated the anti-angiogenic effect of MC-LR. In conclusion, we demonstrated the toxicity of MC-LR on construction of vascular network in corpus luteum, which could provide a new perspective on female infertility or miscarriage caused by environmental factors.
