Peroxisome Proliferator–Activated Receptor-γ Mediates Bisphenol A Inhibition of FSH-Stimulated IGF-1, Aromatase, and Estradiol in Human Granulosa Cells

BackgroundBisphenol A (BPA), a chemical used as a plasticizer, is a potent endocrine disruptor that, even in low concentrations, disturbs normal development and functions of reproductive organs in different species.ObjectivesWe investigated whether BPA affects human ovarian granulosa cell function.MethodsWe treated KGN granulosa cells and granulosa cells from subjects undergoing in vitro fertilization (IVF) with follicle-stimulating hormone (FSH), BPA, or BPA plus FSH in a dose- and time-dependent manner. We then evaluated expression of insulin-like growth factor 1 (IGF-1), aromatase, and transcription factors known to mediate aromatase induction by FSH [including steroidogenic factor-1 (SF-1), GATA4, cAMP response element binding protein-1 (CREB-1), and peroxisome proliferator-activated receptor-gamma (PPARgamma)], as well as 17beta-estradiol (E2) secretion. KGN cells were transfected with a PPARgamma-containing vector, followed by assessment of aromatase and IGF-I expression.ResultsBPA reduced FSH-induced IGF-1 and aromatase expression and E2 secretion in a dose-dependent fashion. Similar effects on aromatase were observed in IVF granulosa cells. SF-1 and GATA4, but not CREB-1, were reduced after BPA treatment, although PPARgamma, an inhibitor of aromatase, was significantly up-regulated by BPA in a dose-dependent manner, with simultaneous decrease of aromatase. Overexpression of PPARgamma in KGN cells reduced FSH-stimulated aromatase and IGF-1 mRNAs, with increasing concentrations of the transfected expression vector, mimicking BPA action. Also, BPA reduced granulosa cell DNA synthesis without changing DNA fragmentation, suggesting that BPA does not induce apoptosis.ConclusionsOverall, the data demonstrate that BPA induces PPARgamma, which mediates down-regulation of FSH-stimulated IGF-1, SF-1, GATA4, aromatase, and E2 in human granulosa cells. These observations support a potential role of altered steroidogenesis and proliferation within the ovarian follicular compartment due to this endocrine disruptor

Asynchronous Rhythm of Steroidogenic Factor 1 and Period Homolog 2 mRNA Expression in Mouse Y1 Adrenocorticol Tumor Cells

The relationship between the expression of Steroidogenic factor 1 (Sf1) and the circadian-related gene, period homolog 2 (Per2), in the adrenal cortex is still unknown. We show here that in Y1 adrenocortical tumor cells, expression of steroidogenic-related genes such as P450scc mRNA and Sf1 mRNA were asynchronous with Per2 mRNA. SF1 promoter analyses showed that the E-box element functions in a rhythmic pattern. Rhythmic expression of Upstream factor 1 mRNA, correlated well with Sf1 mRNA expression. We propose that tumorigenesis of adrenocortical lesions cause disruption of synchronous expression of steroidogenic-related and circadian-related genes

Numerical study of air-entraining and submerged vortices in a pump sump

Numerical detection of harmful vortices in pump sumps, such as an air-entraining vortex (AEV) and a submerged vortex (SMV), is crucially important to develop the drain pump machinery. We performed numerical simulations of the benchmark experiments of the pump sump conducted by Matsui et al. (2006 and 2016) using the OpenFOAM and compared the simulation results with the experimental data considering the effects of turbulence model, grid density and detection method of the vortices. We studied the threshold of the gas-liquid volume fraction of the VOF method and the second invariant of velocity gradient tensor to identify AEV and SMV. The methods proposed in the present paper were found to be very effective for the detection of the vortices, and the simulation results by RANS with the SST k-omega model successfully reproduced the experimental data. LES with the Smagorinsky model, however, was sensitive to the grid system and difficult to reproduce the experimental data even for the finest grid system having 3.7 million cells in the present study

Inhibitor of apoptosis proteins are potential targets for treatment of granulosa cell tumors - implications from studies in KGN

BACKGROUND: Granulosa cell tumors (GCTs) are derived from proliferating granulosa cells of the ovarian follicle. They are known for their late recurrence and most patients with an aggressive form die from their disease. There are no treatment options for this slowly proliferating tumor besides surgery and chemotherapy. In a number of tumors, analogs of the second mitochondria-derived activator of caspases (SMAC), alone or in combination with other molecules, such as TNFα, are evolving as new treatment options. SMAC mimetics block inhibitor of apoptosis proteins (IAPs), which bind caspases (e.g. XIAP), or activate the pro-survival NF-κB pathway (e.g. cIAP1/2). Expression of IAPs by GCTs is yet not fully elucidated but recently XIAP and its inhibition by SMAC mimetics in a combination therapy was described to induce apoptosis in a GCT cell line, KGN. We evaluated the expression of cIAP1 in GCTs and elucidated the effects of the SMAC mimetic BV-6 using KGN as a model. RESULTS: Employing immunohistochemistry, we observed cIAP1 expression in a tissue microarray (TMA) of 42 GCT samples. RT-PCR confirmed expression of cIAP1/2, as well as XIAP, in primary, patient-derived GCTs and in KGN. We therefore tested the ability of the bivalent SMAC mimetic BV-6, which is known to inhibit cIAP1/2 and XIAP, to induce cell death in KGN. A dose response study indicated an EC50 ≈ 8 μM for both, early ( 80) passages, which differ in growth rate and presumably aggressiveness. Quantitative RT-PCR showed upregulation of NF-κB regulated genes in BV-6 stimulated cells. Blocking experiments with the pan-caspase inhibitor Z-VAD-FMK indicated caspase-dependence. A concentration of 20 μM Z-VAD-FMK was sufficient to significantly reduce apoptosis. This cell death was further substantiated by results of Western Blot studies. Cleaved caspase 3 and cleaved PARP became evident in the BV-6 treated group. CONCLUSIONS: Taken together, the results show that BV-6 is able to induce apoptosis in KGN cells. This approach may therefore offer a promising therapeutic avenue to treat GCTs

The efficacy of incretin therapy in patients with type 2 diabetes undergoing hemodialysis

BACKGROUND: Although incretin therapy is clinically available in patients with type 2 diabetes undergoing hemodialysis, no study has yet examined whether incretin therapy is capable of maintaining glycemic control in this group of patients when switched from insulin therapy. In this study, we examined the efficacy of incretin therapy in patients with insulin-treated type 2 diabetes undergoing hemodialysis. METHODS: Ten type 2 diabetic patients undergoing hemodialysis received daily 0.3 mg liraglutide, 50 mg vildagliptin, and 6.25 mg alogliptin switched from insulin therapy on both the day of hemodialysis and the non-hemodialysis day. Blood glucose level was monitored by continuous glucose monitoring. After blood glucose control by insulin, patients were treated with three types of incretin therapy in a randomized crossover manner, with continuous glucose monitoring performed for each treatment. RESULTS: During treatment with incretin therapies, severe hyperglycemia and ketosis were not observed in any patients. Maximum blood glucose and mean blood glucose on the day of hemodialysis were significantly lower after treatment with liraglutide compared with treatment with alogliptin (p < 0.05), but not with vildagliptin. The standard deviation value, a marker of glucose fluctuation, on the non-hemodialysis day was significantly lower after treatment with liraglutide compared with treatment with insulin and alogliptin (p < 0.05), but not with vildagliptin. Furthermore, the duration of hyperglycemia was significantly shorter after treatment with liraglutide on both the hemodialysis and non-hemodialysis days compared with treatment with alogliptin (p < 0.05), but not with vildagliptin. CONCLUSIONS: The data presented here suggest that patients with type 2 diabetes undergoing hemodialysis and insulin therapy could be treated with incretin therapy in some cases