Background: MicroRNA-145 (miR-145) has been reported to be a tumor-suppressing agent in several studies. It can repress pluripotency and control human embryonic stem cell differentiation by regulating the core pluripotency factor OCT4. However, it is not known whether miR-145 can play a role in inducing tumor cell differentiation and repressing growth of tumors.
View Article and Find Full Text PDFObjective: We wished to investigate the aromatase activity (AA) of granulosa cells (GCs) in women undergoing ovarian follicular stimulation for in vitro fertilization (IVF).
Methods: Granulosa cells were harvested from follicular fluid aspirated at the time of oocyte retrieval in women undergoing IVF. Data related to the follicular stimulation and IVF were collected by chart review.
Curr Pharm Des
January 2008
Environmental toxicants comprise a number of man-made organic chemicals which may resist metabolism or their metabolites may persist in the environment and accumulate in the food chain. Some of these persistent chemicals are carried over long distances via the atmospheric transport and can have biological effects in fish, wildlife and humans. In this review the relationship between structure of these chemicals, their mode of action and their possible roles in adverse developmental and reproductive processes in humans will be discussed.
View Article and Find Full Text PDF1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE, DDE), a metabolite of DDT is a persistent hormonally active environmental toxicant present in human serum and follicular fluid. The objective of this study was to investigate the effects of DDE on the expression of the ovarian vascular endothelial growth factor (VEGF) and insulin-like growth factor (IGF-1) in primary cultures of human granulosa cells and in the rat ovary. Granulosa cells were obtained at the time of oocyte retrieval for in vitro fertilization and cultured with environmentally relevant concentrations of DDE.
View Article and Find Full Text PDFDemasculinization by environmental endocrine-disrupting chemicals (EDCs) is observed in many animal species but less evident in humans. Rodent studies with gestational exposure to either the fungicide vinclozolin or the insecticide methoxychlor demonstrate impaired male fertility with abnormal DNA methylation patterns in spermatozoa. Once established, these epigenetic changes may be permanent and thus paternally passed to subsequent generations.
View Article and Find Full Text PDFJ Steroid Biochem Mol Biol
September 2006
Progesterone is produced by granulosa cells under the influence of luteinizing hormone. Nuclear progesterone receptors have been found in rat granulosa cells. Human granulosa-lutein cells rapidly respond to progesterone with an increase in intracellular calcium suggesting the existence of a nongenomic mechanism.
View Article and Find Full Text PDFJ Assist Reprod Genet
February 2006
Purpose: To validate an expedited method for the removal of erythrocytes when preparing IVF granulosa-luteal cells for culture.
Methods: Granulosa cells were enriched for culturing from follicular aspirates by density gradient centrifugation and by hypo-osmotic lysis treatments.
Results: Cells prepared by either method showed the same cell viability and produced progesterone in similar quantities.
Following our previous demonstration that p,p'-DDE (dichlorodiphenylchloroethylene), at environmentally relevant concentrations, can rapidly increase intracellular calcium [Ca2+]i concentrations in human granulosa-lutein cells, we examined whether other pesticides, such as Kepone, o,p-DDE and methoxychlor, have similar effects. Cultured human granulosa-lutein cells were loaded with Fura-2 AM, and changes in [Ca2+]i concentrations within small areas of single cells were studied with a dynamic digital Ca2+ imaging system. Kepone, at concentrations of 0.
View Article and Find Full Text PDFPersistent metabolites of pesticides such as p,p'-DDE, at environmentally relevant concentrations, have been shown to have a rapid effect on intracellular calcium [Ca2+]i concentrations in human granulosa-lutein cells. Since endocrine disrupting substances can be transferred from the maternal circulation to the fetus the present study examined whether the pesticides, kepone, o,p-DDE, p,p'-DDE and methoxychlor, could alter cytoplasmic calcium [Ca2+]cyt concentrations in human umbilical vein endothelial (HUVE) cells. Cultured HUVE cells were loaded with Fura-2 AM and changes in [Ca2+]cyt of single cells were studied using a dynamic digital Ca2+ imaging system.
View Article and Find Full Text PDFBackground: The present study examined whether the sex steroids, estradiol and progesterone, could alter cytoplasmic calcium concentrations ([Ca(2+)](cyt)) in human granulosa-lutein cells.
Methods: Human granulosa cells were obtained at the time of oocyte retrieval for IVF and cultured for 3-7 days. Cells were loaded with Fura-2 AM and changes in [Ca(2+)](cyt) of single cells were studied using a dynamic digital Ca(2+) imaging system.
Reproductive function has been shown to be sensitive to changes in the physical, psychosocial and chemical environments. Although reproductive effects of occupational exposure to hazardous chemicals have been well documented in the literature, the potential effects of chemical contaminants at levels representative of contemporary exposures in the general population are much less certain. Evidence for adverse effects of exposure to environmental contaminants is more conclusive among the lower animals than for humans where considerable controversy remains.
View Article and Find Full Text PDFBackground: 1,1-Dichloro-2,2-bis(P-chlorophenyl)ethylene (P,P'-DDE, DDE), a metabolite of DDT, is a persistent hormonally active environmental toxicant which has been found in human serum and follicular fluid. The objective of this study was to investigate the interaction between FSH and ppDDE on aromatase activity in primary cultures of human granulosa cells.
Methods: Granulosa cells were obtained at the time of oocyte retrieval for IVF procedures and cultured in defined medium containing FSH and environmentally relevant concentrations of DDE.
1,1-Dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), a metabolite of DDT (1,1-dichlorodiphenyltrichloroethane), is a persistent hormonally active environmental toxicant that has been found in human serum and follicular fluid. The objective of this study was to determine whether DDE can alter free calcium ion concentrations in the cytosol ([Ca(2+)](cyt)) of human granulosa cells. Changes in [Ca(2+)](cyt) in single cells loaded with Fura-2 were studied using a dynamic digital Ca(2+) imaging system.
View Article and Find Full Text PDFIn a related reproductive toxicology study designed to investigate the effects of in utero exposure to environmental toxicants and potential interaction with postnatal genistein, gross enlargement of thoracic mammary glands was observed in female offspring at 200 days of age. Therefore, the objective of this study was to analyze the effect of in utero exposure to a mixture of toxicants on mammary gland morphology. Time-mated Sprague-Dawley rats were treated on days 9-16 of gestation with vehicle or a mixture of environmental toxicants at 1x the acceptable daily intake.
View Article and Find Full Text PDFBenzo[a]pyrene (BaP) is an agonistic ligand for the aryl hydrocarbon receptor (AhR) and a major environmental carcinogen implicated in the aetiology of lung cancer through the induction of benzo[a]pyrene diol epoxidation (BPDE) and BPDE-DNA adducts. Because BaP metabolization requires cytochrome P-450 1A1 (CYP1A1) induction through activation of the AhR, we hypothesized that resveratrol, a natural competitive inhibitor of AhR, could prevent these adverse effects of BaP on the lung. Balb-C mice were injected for 5 weeks with corn oil, BaP (5 mg kg(-1) week(-1)), resveratrol (50 mg kg(-1) week(-1)) or BaP + resveratrol.
View Article and Find Full Text PDFEnvironmental chemicals are thought to adversely affect human reproductive function, however there are no studies that have explored the association between failed fertilization and exposure of both partners to environmental contaminants. Therefore, we collected blood and follicular fluid from the female partner and seminal plasma from the male partner of 21 couples attending an in vitro fertilization (IVF) program, in order to determine the extent of the existence of environmental chemicals in these fluids. Any relationship to the outcome of IVF was also considered.
View Article and Find Full Text PDFThe human population in the industrialized world is ubiquitously exposed to complex mixtures of persistent pollutants that contaminate food, water, and air. A large number of these contaminants have been shown to cause significant toxicity to the hypothalamic-pituitary-thyroid (HPT) axis in laboratory animal studies, through a variety of mechanisms, although these effects occur at levels of exposure greatly in excess of common human exposure. While many of the mechanisms of thyroid toxicity of these substances are potentially complementary, little is known of the degree of interaction of common persistent contaminants on responses of the HPT axis.
View Article and Find Full Text PDFHuman populations throughout the world are exposed daily to low levels of environmental contaminants. The consequences of potential interactions of these compounds to human endocrine, reproductive, and immune function remain unknown. The current study examines the effects of subchronic oral exposure to a complex mixture of ubiquitous persistent environmental contaminants that have been quantified in human reproductive tissues.
View Article and Find Full Text PDFBenzo(a)pyrene (BaP), an aryl hydrocarbon receptor (AhR) ligand present in cigarette smoke and car exhaust, is thought to have negative effects on male reproduction. We hypothesized that BaP damages sperm through AhR activation, phase I enzyme induction, DNA adduct formation, and increased germ cell apoptosis in the testis, and that resveratrol, a natural competitive inhibitor of the AhR found in some red wines, could prevent the adverse effects of BaP on sperm. Male Balb C mice were injected subcutaneously (s.
View Article and Find Full Text PDFBackground: Swim-up techniques for sperm separation may have detrimental effects on sperm DNA. We wished to determine whether the normal swim-up method with centrifugation used in our laboratory, which involves a centrifugation step, was harmful to sperm compared with swim-up without centrifugation.
Methods: Semen samples were obtained from patients undergoing IVF or andrology assessment.
The objective of this study was to investigate the relationship between oocyte morphology and follicular fluid steroid concentrations in patients being treated with intracytoplasmic sperm injection. A total of 82 IVF cycles were evaluated in patients aged 24-40 years. Oocytes at metaphase II were graded into four groups according to the status of the first polar body and the size of the perivitelline space.
View Article and Find Full Text PDFWe have shown that the melatonin receptor agonist, 2-[125I] iodomelatonin, binds to high-affinity guanine nucleotide-sensitive sites on human granulosa (HG) cell membranes. In order to confirm the presence of melatonin receptors in HG cells, we have now used a reverse transcriptase-polymerase chain reaction (RT-PCR) procedure to examine receptor subtype expression. RT-PCR studies revealed the presence of the mt1 (Mel1alpha) melatonin receptor subtype in ten single or pooled HG cell samples which were obtained from 14 patients.
View Article and Find Full Text PDFEur J Appl Physiol Occup Physiol
January 1999
Our purposes were (1) to examine resting arterial blood pressure following an acute bout of resistance exercise and submaximal dynamic exercise, (2) to examine the effects of these exercises on the plasma concentrations of atrial natriuretic peptide ([ANP]), and (3) to evaluate the potential relationship between [ANP] and post-exercise blood pressure. Thirteen males [24.3+/-(2.
View Article and Find Full Text PDFDuring follicular development, a co-ordinated gonadotrophin and endocrine environment is believed to be essential for normal function of the resulting corpus luteum. Whether differences in the gonadotrophins used to promote follicular development can have lasting effects on granulosa cells after they have undergone luteinization and culture, remains to be studied. We measured steroid production under basal and human chorionic gonadotrophin (HCG) stimulation in short and long term cultures of luteinizing granulosa cells obtained from normal ovulatory women undergoing assisted folliculogenesis with either human menopausal gonadotrophin (HMG) or follicle stimulating hormone (FSH).
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