Search

Cholesterol sulfate (CS) is a major sterol sulfate in human plasma that is detected in the uterine endometrium. CS plays a role in steroidogenesis, cellular membrane stabilization, and regulation of the skin barrier. We previously reported that CS increased in rabbit endometrium during the implantation period. Recently, CS has been reported to be a ligand of retinoic acid receptor-related orphan receptor alpha (RORA). NR1D1 is one of the genes regulated by RORA. In the present study, we investigated the regulation of RORA and NR1D1 by CS in human endometrium. We determined the association-dissociation curves for the interaction of CS with RORA and the kinetic rates by surface plasmon resonance. Immunohistochemical staining and in situ hybridization revealed that RORA and NR1D1 were expressed in human endometrial stromal and epithelial cells. CS treatment significantly induced the mRNA expression of RORA and NR1D1 mRNA in ESCs. The results of a luciferase assay showed that RORA significantly activated the human NR1D1 promoter regardless of CS. Our results suggest that CS regulates the expression of RORA responsive genes in human endometrial cells but not as a ligand for RORA., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

We demonstrated that cholesterol sulfate (CS) inhibits invasion of a trophoblast cell line and plasmin enzyme activity in a noncompetitive manner by binding to the enzyme itself, suggesting that CS can repress cell invasion by inhibiting proteinases such as those involved in the plasminogen activator/plasmin system. Considering these results, it is possible that CS may act as a signaling molecule between the trophoblast and endometrium, and may regulate the process of implantation., (Copyright © 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: To investigate the hormonal regulation of SULT2B1b in human endometrium., Design: In vitro study with human endometrial tissues and cultured human endometrial cells., Setting: University hospital., Patient(s): Thirty-seven women undergoing hysterectomy for benign disease., Intervention(s): Human endometrial tissues were collected for in situ hybridization. Culture medium of human endometrial epithelial cells (EECs) was collected for determination of secretion of cholesterol sulfate (CS). Total RNAs were extracted from human endometrial tissues and cultured cells for real-time reverse transcriptase-polymerase chain reaction (RT-PCR)., Main Outcome Measure(s): The expression of SULT2B1b mRNA in human endometrial tissues and cultured cells., Result(s): In situ hybridization studies and real-time RT-PCR showed that the amount of SULT2B1b mRNA in human endometrial tissues was significantly higher during the midluteal phase than during other phases of the menstrual cycle. The secretion of CS from EECs was confirmed using [(35)S]-phosphoadenosine phosphosulfate. The expression of SULT2B1b mRNA was induced by cAMP or P in human endometrial stromal cells (ESCs), whereas it was induced by cAMP or relaxin in EECs. The induction of SULT2B1b mRNA by P or relaxin was abolished by the specific protein kinase A (PKA) inhibitor, Rp-adenosine 3',5' cyclic monophosphothioate (Rp-cAMPS)., Conclusion(s): The expression of SULT2B1b mRNA in ESCs is induced by P and that in EECs is induced by relaxin via the cAMP pathway., (Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Matrix metalloproteinases (MMPs) and the plasminogen activator (PA)/plasmin system are two major groups of proteases involved in the matrix degradation required for embryo implantation. We previously showed that the content of cholesterol sulfate (CS) in rabbit endometrium increases characteristically during the implantation period. Furthermore, CS has been reported to inhibit serine proteases. In this study, we investigated whether CS can regulate the activity of proteases in cultured human endometrial stromal cells., Methods and Results: CS (1-30 microM) and plasminogen (precursor of plasmin) were added to the culture media of human endometrial stromal cells and incubated for 24 h. Culture media were collected for analysis of plasmin and MMP-2, -3 and -9 enzyme activities using fluorescence assays. Plasmin and MMP-3 activities were significantly reduced by CS in a dose-dependent manner (P < 0.001). Western blot analysis of the culture media revealed that CS inhibited the conversion by plasmin of MMP-3 from the precursor form to the active form. Fluorescence assay using a common substrate of MMP-2 and MMP-9 showed that enzymatic activity remains at approximately 50%, even at 30 microM CS. Gelatin zymography demonstrated that CS inhibited the activation of MMP-9 but not MMP-2 from the precursor, suggesting that the activation of MMP-2 may be independent of plasmin., Conclusions: CS inhibits not only plasmin activity but also MMP activities indirectly by inhibiting the plasmin-mediated process. These findings suggest that CS may be an important regulator of proteolysis during trophoblast invasion.

Cholesterol sulfate (CS) is a component of cell membranes that plays a role in stabilizing the cell membrane. We previously reported that CS increased in the endometrium during implantation, suggesting that CS plays an important role in reproduction. It has been reported that CS regulates progesterone and pregnenolone production in the placenta, adrenal glands and ovary. The regulatory mechanisms of steroid hormone production by CS, however, are still unknown. In the present study, we investigated the effect of CS on the expression of progesterone production-related genes in KGN cells, derived from human granulosa-like tumor. KGN cells were cultured with CS (10 muM) or cholesterol (10 muM) in the presence of 8-bromo-cAMP (1 mM). Progesterone levels in the culture media were measured by enzyme linked fluorescent assay at 24 h after treatment of CS and cAMP. Total RNAs were extracted for quantitative real time RT-PCR with specific primer of StAR protein, P450scc, HSD3B2, ferredoxin and ferredoxin reductase. Whole cell lysates were extracted for western blot analysis with antibody for StAR protein. Progesterone concentration in the culture medium increased to 38-fold by treatment of cAMP. CS significantly reduced progesterone concentration by 30% compared with those of cAMP treatment (p<0.05), while cholesterol did not change the progesterone concentration. CS treatment down-regulated the expression of StAR mRNA and P450scc mRNA was to 54% and 60%, respectively (p<0.05). Western blot analysis revealed that the amount of StAR protein was also reduced by CS treatment. The expression of HSD3B2 mRNA was up-regulated to 3.4-fold by treatment of cAMP. The expression of ferredoxin and ferredoxin reductase mRNA was not affected by CS treatment. These data implied that CS has an inhibitory effect on progesterone production by regulating the expression of StAR and P450scc gene expression.