Intrauterine hyperglycemia impairs endometrial receptivity via up-regulating SGK1 in diabetes

Diabetes is a complex metabolic disorder which can adversely affect reproductive function. SGK1 is found to be up-regulated in multiple tissues of diabetic patients. However, the effects of diabetes on endometrial SGK1 expression and endometrial receptivity remain unknown. In this study, we established a streptozotocin-induced diabetic mouse model and observed reduced implantation sites, retarded development of pinopodes, increased SGK1, and aberrant expression of LIF and MUC1 in the endometrial epithelium. We injected the uterine lumen of normal mice with high-glucose solution and cultured endometrial cells in high-glucose medium to mimic intrauterine hyperglycemia. Both studies provided compelling evidence that hyperglycemia could lead to diminished embryo implantation and dysregulated SGK1, LIF and MUC1. Additionally, through over-expression of SGK1 in vivo and in vitro, we found that enhanced SGK1 also decreased LIF expression, increased MUC1 expression, and attenuated embryo implantation rate. We further identified that hyperglycemia-activated SMAD2/3 might be responsible for the enhancement of SGK1 and verified directly the interaction between SMAD3 and corresponding SMAD binding elements within SGK1 promoter. Taken together, our study confirmed the association between diabetes-related hyperglycemia and endometrial receptivity defects. Hyperglycemia-induced SGK1 has a tremendous role in this pathological process, rendering it as an attractive therapeutic target for diabetes-related reproductive disorders.

An alternative splicing variant of mineralocorticoid receptor discovered in preeclampsia tissues and its effect on endothelial dysfunction

The pathophysiology of preeclampsia(PE)remains unclear.PE spiral artery remodeling dysfunction and PE offspring cardiovascular future development has been a worldwide concern.We collected placental and umbilical artery samples from normotensive and PE pregnancies.Mineralocorticoid receptor(MR)and its alternative splicing variant(ASV)expression and their biological effects on PE were examined.An MR ASV was found to be highly expressed in all PE samples and slightly expressed in about half of the normotensive samples(umbilical artery,~57.58%;placenta,~36.84%).The MR ASV expression was positively associated with blood pressure in both groups.The MR ASV protein changed the aldosterone-induced expression pattern of MR target genes related to ion exchanges and cell signaling pathways.The MR ASV can also impair the proliferation,migration,and tube formation ability of endothelial cells.These findings indicate that MR ASV in PE placenta plays a pathogenic role in PE pathophysiology,especially in endothelial dysfunction,and the existence of the MR ASV in PE umbilical artery provides a new direction in the study of PE offspring with increased risk of cardiovascular diseases.