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Sample records for placental aromatase cytochrome

  1. Placental expression and molecular characterization of aromatase cytochrome P450 in the spotted hyena (Crocuta crocuta).

    PubMed

    Conley, A J; Corbin, C J; Browne, P; Mapes, S M; Place, N J; Hughes, A L; Glickman, S E

    2007-07-01

    At birth, the external genitalia of female spotted hyenas (Crocuta crocuta) are the most masculinized of any known mammal, but are still sexually differentiated. Placental aromatase cytochrome P450 (P450arom) is an important route of androgen metabolism protecting human female fetuses from virilization in utero. Therefore, placental P450arom expression was examined in spotted hyenas to determine levels during genital differentiation, and to compare molecular characteristics between the hyena and human placental enzymes. Hyena placental P450arom activity was determined at gestational days (GD) 31, 35, 45, 65 and 95 (term, 110), and the relative sensitivity of hyena and human placental enzyme to inhibition by the specific inhibitor, Letrozole, was also examined. Expression of hyena P450arom in placenta was localized by immuno-histochemistry, and a full-length cDNA was cloned for phylogenetic analysis. Aromatase activity increased from GD31 to a peak at 45 and 65, apparently decreasing later in gestation. This activity was more sensitive to inhibition by Letrozole than was human placental aromatase activity. Expression of P450arom was localized to syncytiotrophoblast and giant cells of mid-gestation placentas. The coding sequence of hyena P450arom was 94% and 86% identical to the canine and human enzymes respectively, as reflected by phylogenetic analyses. These data demonstrate for the first time that hyena placental aromatase activity is comparable to that of human placentas when genital differentiation is in progress. This suggests that even in female spotted hyenas clitoral differentiation is likely protected from virilization by placental androgen metabolism. Decreased placental aromatase activity in late gestation may be equally important in allowing androgen to program behaviors at birth. Although hyena P450arom is closely related to the canine enzyme, both placental anatomy and P450arom expression differ. Other hyaenids and carnivores must be investigated to

  2. The effect of opiates on the activity of human placental aromatase/CYP19.

    PubMed

    Zharikova, Olga L; Deshmukh, Sujal V; Kumar, Meena; Vargas, Ricardo; Nanovskaya, Tatiana N; Hankins, Gary D V; Ahmed, Mahmoud S

    2007-01-15

    Aromatase, cytochrome P450 19, is a key enzyme in the biosynthesis of estrogens by the human placenta. It is also the major placental enzyme that metabolizes the opiates L-acetylmethadol (LAAM), methadone, and buprenorphine (BUP). Methadone and BUP are used in treatment of the opiate addict and are competitive inhibitors of testosterone conversion to estradiol (E(2)) and 16alpha-hydroxytestosterone (16-OHT) to estriol (E(3)) by aromatase. The aim of this investigation is to determine the effect of 20 opiates, which can be administered to pregnant patients for therapeutic indications or abused, on E(2) and E(3) formation by placental aromatase. Data obtained indicated that the opiates increased, inhibited, or had no effect on aromatase activity. Their effect on E(3) formation was more pronounced than that on E(2) due to the lower affinity of 16-OHT than testosterone to aromatase. The K(i) values for the opiates that inhibited E(3) formation were sufentanil, 7 +/- 1 microM; LAAM, 13 +/- 8 microM; fentanyl, 25 +/- 5 microM; oxycodone, 92 +/- 22 microM; codeine, 218 +/- 69 microM; (+)-pentazocine, 225 +/- 73 microM. The agonists morphine, heroin, hydromorphone, oxymorphone, hydrocodone, propoxyphene, meperidine, levorphanol, dextrorphan, and (-)-pentazocine and the antagonists naloxone and naltrexone caused an increase in E(3) formation by 124-160% of control but had no effect on E(2) formation. Moreover, oxycodone and codeine did not inhibit E(2) formation and the IC(50) values for fentanyl, sufentanil, and (+)-pentazocine were >1000 microM. It is unlikely that the acute administration of the opiates that inhibit estrogen formation would affect maternal and/or neonatal outcome. However, the effects of abusing any of them during the entire pregnancy are unclear at this time. PMID:17118343

  3. Aromatase inhibition by synthetic lactones and flavonoids in human placental microsomes and breast fibroblasts - A comparative study

    SciTech Connect

    Meeuwen, J.A. van Nijmeijer, S.; Mutarapat, T.; Ruchirawat, S.; Jong, P.C. de; Piersma, A.H.; Berg, M. van den

    2008-05-01

    Interference of exogenous chemicals with the aromatase enzyme can be useful as a tool to identify chemicals that could act either chemopreventive for hormone-dependent cancer or adverse endocrine disruptive. Aromatase is the key enzyme in the biosynthesis of steroids, as it converts androgens to estrogens. Certain flavonoids, plant derived chemicals, are known catalytic aromatase inhibitors. Various systems are in use to test aromatase inhibitory properties of compounds. Commonly used are microsomes derived from ovary or placental tissue characterized by high aromatase activity. To a lesser extent whole cell systems are used and specifically cell systems that are potential target tissue in breast cancer development. In this study aromatase inhibitory properties of fadrozole, 8-prenylnaringenin and a synthetic lactone (TM-7) were determined in human placental microsomes and in human primary breast fibroblasts. In addition, apigenin, chrysin, naringenin and two synthetic lactones (TM-8 and TM-9) were tested in human microsomes only. Comparison of the aromatase inhibitory potencies of these compounds between the two test systems showed that the measurement of aromatase inhibition in human placental microsomes is a good predictor of aromatase inhibition in human breast fibroblasts.

  4. Three-dimensional model of cytochrome P450 human aromatase.

    PubMed

    Loge, Cedric; Le Borgne, Marc; Marchand, Pascal; Robert, Jean-Michel; Le Baut, Guillaume; Palzer, Martina; Hartmann, Rolf W

    2005-12-01

    A three-dimensional (3-D) structure of human aromatase (CYP 19) was modeled on the basis of the crystal structure of rabbit CYP2C5, the first solved X-ray structure of an eukaryotic cytochrome P450 and was evaluated by docking S-fadrozole and the steroidal competitive inhibitor (19R)-10-thiiranylestr-4-ene-3,17-dione, into the enzyme active site. According to a previous pharmacophoric hypothesis described in the literature, the cyano group of S-fadrozole partially mimics the steroid backbone C(17) carbonyl group of (19R)-10-thiiranylestr-4-ene-3,17-dione, and was oriented in a favorable position for H-bonding with the newly identified positively charged residues Lys 119 and Arg435. In addition, this model is consistent with the recent combined mutagenesis/modeling studies already published concerning the roles ofAsp309 and His480 in the aromatization of the steroid A ring. PMID:16408794

  5. Genetic studies to characterize the origin of the mutation in placental aromatase deficiency

    SciTech Connect

    Harada, Nobuhiro; Ogawa, Hisamitsu; Yamada, Kazuyo ); Shozu, Makio )

    1992-09-01

    Placental aromatase deficiency has recently been shown to be due to expression of RNA transcripts encoding abnormal aromatase molecules with 29 extra amino acids. To establish whether this aromatase deficiency is a hereditary or sporadic disease, the authors examined the genetic defect of the aromatase gene in the family of a patient. Direct sequencing of fragments of the aromatase gene prepared by PCR revealed that the splicing donor sequence (GT) of intron 6 in controls was mutated to GC in the patient, whereas the parents showed signals of both GT and GC. Subcloning of PCR products of the parents gave two different types of clones with GT and GC sequences in this site. Futhermore, for diagnosis of this deficiency, competitive-oligonucleotide-priming PCR of genomic DNA was performed in the presence of both normal and mutational oligonucleotide primers labeled with two kinds of fluorescent dyes, and the products were separated by agarose gel electrophoresis and were detected fluorometrically in the gel. Genomic DNA of the patient gave a PCR product primed only by the mutational primer, whereas that of controls gave a product primed only by the normal primer. The PCR products of the parents were primed by both primers. The results obtained by this fluorometric method were also confirmed by differential hybridizations with specific oligonucleotide probes. Thus these findings indicate that this deficiency is an autosomal hereditary disease and that the patient is a homozygote, while the parents are heterozygotes, for this mutation. 23 refs., 4 figs.

  6. Inhibition of aromatase activity in human placental microsomes by 13-retro-antiprogestins.

    PubMed

    Shimizu, Y; Yarborough, C P; Elger, W; Chwalisz, K; Osawa, Y

    1995-02-01

    Mifepristone (RU 486), used clinically for the termination of early pregnancy, and its acetyl and 13-retro (13 alpha) analogs show potent antiproliferative effects against estrogen-dependent human breast tumors and endometriosis. However, there has been no report on direct inhibition of aromatase by antiprogesterones. Aromatase inhibitors have been shown to be effective against estrogen-dependent breast cancer. We evaluated the inhibition of aromatase by various antiprogestins (ZK 112.993, ZK 98.734, ZK 114.043, ZK 98.299, and ZK 114.863). Human placental microsomes were incubated with [1 beta-3H,4-14C] androstenedione (3-114 nM) in the presence of NADPH, with or without putative inhibitors (10-200 microM). Aromatase activity was assessed by tritium release to water from the 1 beta-position of the substrate. ZK 112.993 and ZK 98.734 did not show any inhibitory effect. The statistical analysis of the data using standard errors was obtained from replicate experiments. ZK 114.043 showed slight inhibition with a Ki of 54.8 +/- 6.4 microM (m +/- SE, n = 6) against androstenedione aromatization. The two 13-retro-steroids, ZK 98.299 and ZK 114.863, showed aromatase inhibition with Ki values of 19.0 +/- 1.5 microM (n = 7) and 12.7 +/- 0.94 microM (n = 7), respectively, which is weak with respect to some known potent inhibitors, but significant when compared with the other antiprogestins which were tested. The results suggest that the unnatural 13-retro-antiprogestin conformation may have a better fit to the aromatase active site than the natural 13 beta-antiprogestin conformation. (Steroids 60:234-238, 1995).

  7. Inhibition of human placental aromatase activity by hydroxylated polybrominated diphenyl ethers (OH-PBDEs)

    SciTech Connect

    Canton, Rocio F. Scholten, Deborah E.A.; Marsh, Goeran; Jong, Paul C. de; Berg, Martin van den

    2008-02-15

    Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in many different polymers, resins and substrates. Due to their widespread production and use, their high binding affinity to particles, and their lipophilic properties, several PBDE congeners can bioaccumulate in the environment. As a result, PBDEs and their hydroxylated metabolites (OH-PBDEs) have been detected in humans and various wildlife samples, such as birds, seals, and whales. Furthermore, certain OH-PBDEs and their methoxylated derivatives (MeO-PBDEs) are natural products in the marine environment. Recently, our laboratory focused on the possible effects on steroidogenesis of PBDEs and OH-PBDEs, e.g. in the human adrenocortical carcinoma (H295R) cell line indicating that some OH-PBDEs can significantly influence steroidogenic enzymes like CYP19 (aromatase) and CYP17. In the present study, human placental microsomes have been used to study the possible interaction of twenty two OH-PBDEs and MeO-PBDEs with aromatase, the enzyme that mediates the conversion of androgens into estrogens. All OH-PBDE derivates showed significant inhibition of placental aromatase activity with IC{sub 50} values in the low micromolar range, while the MeO-PBDEs did not have any effect on this enzyme activity. Enzyme kinetics studies indicated that two OH-PBDEs, 5-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (5-OH-BDE47) and 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE47), had a mixed-type inhibition of aromatase activity with apparent K{sub i}/K{sub i}' of 7.68/0,02 {mu}M and 5.01/0.04 {mu}M respectively. For comparison, some structurally related compounds, a dihydroxylated polybrominated biphenyl, which is a natural product (2,2'-dihyroxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diOH-BB80)) and its non-bromo derivative were also included in the study. Again inhibition of aromatase activity could be measured, but their potency was significantly less than those observed for the OH-PBDEs. These results show

  8. Cytochrome P450 aromatase expression in canine nervous tissue: an immunohistochemical study.

    PubMed

    Karahan, S; Yarim, M; Harada, N

    2008-01-01

    The enzyme cytochrome P450 aromatase is responsible for conversion of androgens to estrogens. Estrogens have been implicated in neurophysiology and neuropathology. The present study investigated the presence of aromatase immunoreactivity in the temporal, parietal and occipital cortices, olfactory bulb, cerebellum, and choroid plexus of the normal dog. Aromatase immunoreactivity was localized exclusively in neurons in the cortices and olfactory bulb. Immunoreactivity was also present in a small number of astrocytes in the substantia alba of the cerebellum. In the cortical regions, immunoreactive neurons, morphologically identified as pyramidal cells, were found throughout Layer II down to Layer VI, but not all pyramidal neurons were immunoreactive. In the olfactory bulb, immunoreactive neurons were mainly observed in mitral cells and inner granular cell layers. In the cerebellum, immunoreactivity was present in neurons of the deep cerebellar nuclei and in some neurons of the molecular and granular cell layers. Immunoreactivity was also present in endothelial cells of the subarachnoid vessels and those adjacent to ventricles in the cortex. The presence of well defined cytoplasmic aromatase immunoreactivity in neurons, some astrocytes, and endothelial cells suggests estrogen involvement in CNS physiology and function in the dog. The presence of aromatase in ependymal cells lining cerebral ventricles and choroid epithelial cells suggests that these cells may be partially responsible for estrogen concentration in the cerebrospinal fluid.

  9. Differential effects of glyphosate and roundup on human placental cells and aromatase.

    PubMed

    Richard, Sophie; Moslemi, Safa; Sipahutar, Herbert; Benachour, Nora; Seralini, Gilles-Eric

    2005-06-01

    Roundup is a glyphosate-based herbicide used worldwide, including on most genetically modified plants that have been designed to tolerate it. Its residues may thus enter the food chain, and glyphosate is found as a contaminant in rivers. Some agricultural workers using glyphosate have pregnancy problems, but its mechanism of action in mammals is questioned. Here we show that glyphosate is toxic to human placental JEG3 cells within 18 hr with concentrations lower than those found with agricultural use, and this effect increases with concentration and time or in the presence of Roundup adjuvants. Surprisingly, Roundup is always more toxic than its active ingredient. We tested the effects of glyphosate and Roundup at lower nontoxic concentrations on aromatase, the enzyme responsible for estrogen synthesis. The glyphosate-based herbicide disrupts aromatase activity and mRNA levels and interacts with the active site of the purified enzyme, but the effects of glyphosate are facilitated by the Roundup formulation in microsomes or in cell culture. We conclude that endocrine and toxic effects of Roundup, not just glyphosate, can be observed in mammals. We suggest that the presence of Roundup adjuvants enhances glyphosate bioavailability and/or bioaccumulation.

  10. Inhibition of cytochrome p450 brain aromatase reduces two male specific sexual behaviours in the male Endler guppy (Poecilia reticulata).

    PubMed

    Hallgren, Stefan L E; Linderoth, Maria; Olsén, K Håkan

    2006-07-01

    In mammalian and avian vertebrate groups, androgens act as controlling agents on male aggression and courtship behaviour by their conversion to oestrogens by cytochrome P450 aromatase in well-defined brain regions. Despite the fact that bony fishes have exceptionally high brain aromatase activity, little is known about it's possible regulatory effects on the reproductive behaviours of teleosts. In this study, Endler guppy males (Poecilia reticulata) were subjected to 26-29 days of 24-h exposure to two different concentrations (15 and 100 microg/L) of the aromatase inhibitor fadrozole in the water. Compared with the control males, two of three courtship activities in males exposed to the higher concentration were reduced when they were paired with receptive stimulus females. Reduction in brain aromatase activity was confirmed in both exposed groups with the use of the tritiated water assay.

  11. Perfluorinated chemicals: Differential toxicity, inhibition of aromatase activity and alteration of cellular lipids in human placental cells

    SciTech Connect

    Gorrochategui, Eva; Pérez-Albaladejo, Elisabet; Casas, Josefina; Lacorte, Sílvia; Porte, Cinta

    2014-06-01

    The cytotoxicity of eight perfluorinated chemicals (PFCs), namely, perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorododecanoic acid (PFDoA), perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) was assessed in the human placental choriocarcinoma cell line JEG-3. Only the long chain PFCs – PFOS, PFDoA, PFNA, PFOA – showed significant cytotoxicity in JEG-3 cells with EC50 values in the range of 107 to 647 μM. The observed cytotoxicity was to some extent related to a higher uptake of the longer chain PFCs by cells (PFDoA > PFOS ≫ PFNA > PFOA > PFHxA). Moreover, this work evidences a high potential of PFOS, PFOA and PFBS to act as aromatase inhibitors in placental cells with IC50s in the range of 57–80 μM, the inhibitory effect of PFBS being particularly important despite the rather low uptake of the compound by cells. Finally, exposure of JEG-3 cells to a mixture of the eight PFCs (0.6 μM each) led to a relative increase (up to 3.4-fold) of several lipid classes, including phosphatidylcholines (PCs), plasmalogen PC and lyso plasmalogen PC, which suggests an interference of PFCs with membrane lipids. Overall, this work highlights the ability of the PFC mixture to alter cellular lipid pattern at concentrations well below those that generate toxicity, and the potential of the short chain PFBS, often considered a safe substitute of PFOS, to significantly inhibit aromatase activity in placental cells. - Highlights: • Eight perfluorinated chemicals of different chain lengths have been selected. • Long chain ones – PFOS, PFDoA, PFNA, PFOA – were cytotoxic in placenta cells. • The uptake of long chain perfluorinated chemicals by cells was comparatively higher. • PFOS, PFOA and the short chain PFBS significantly inhibited aromatase activity. • A mixture of perfluorinated chemicals significantly altered placenta cell

  12. CYP19 (cytochrome P450 aromatase) gene polymorphism in murrah buffalo heifers of different fertility performance.

    PubMed

    Suneel Kumar, O; Sharma, Deepti; Singh, Dheer; Sharma, M K

    2009-06-01

    The most common cause of infertility in buffaloes is anestrum. During late maturity the ovaries are in a state of true anestrum. One of the predominant causes of true anestrum is a low level of ovarian estrogens. The key enzyme in estrogen biosynthesis is cytochrome P450 aromatase, encoded by CYP19 gene. In the present study, CYP19 gene polymorphism was analyzed by Single Strand Conformational Polymorphism (SSCP) in buffaloes of different fertility performance. The SSCP and sequence analysis revealed 4 allelic variants in coding exons and introns which unaltered the protein sequence. However, a significant polymorphism (T/C heterozygote) was found near TATA binding protein region in regulatory part (a facet of promoter II) at position 23 of CYP19 exon 2, in all late matured and 50% of late maturing animals. Based on these observations and remarks of earlier workers, a hypothesis is proposed for the physiology of late maturity in buffaloes. PMID:19101001

  13. Porcine Hypothalamic Aromatase Cytochrome P450: Isoform Characterization, Sex-Dependent Activity, Regional Expression, and Regulation by Enzyme Inhibition in Neonatal Boars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domestic pigs have three CYP19 genes encoding functional paralogues of the enzyme aromatase cytochrome P450 (P450arom) that are expressed in the gonads, placenta and pre-implantation blastocyst. All catalyze estrogen synthesis, but the “gonadal” type enzyme is unique in also synthesizing a nonaromat...

  14. Novel Aromatase Inhibitors by Structure-Guided Design

    PubMed Central

    Ghosh, Debashis; Lo, Jessica; Morton, Daniel; Valette, Damien; Xi, Jingle; Griswold, Jennifer; Hubbell, Susan; Egbuta, Chinaza; Jiang, Wenhua; An, Jing; Davies, Huw M. L.

    2012-01-01

    Human cytochrome P450 aromatase catalyzes with high specificity the synthesis of estrogens from androgens. Aromatase inhibitors (AIs) such as exemestane, 6-methylideneandrosta-1,4-diene-3,17-dione, are preeminent drugs for the treatment of estrogen-dependent breast cancer. The crystal structure of human placental aromatase has shown an androgen-specific active site. By utilization of the structural data, novel C6-substituted androsta-1,4-diene-3,17-dione inhibitors have been designed. Several of the C6-substituted 2-alkynyloxy compounds inhibit purified placental aromatase with IC50 values in the nanomolar range. Antiproliferation studies in a MCF-7 breast cancer cell line demonstrate that some of these compounds have EC50 values better than 1 nM, exceeding that for exemestane. X-ray structures of aromatase complexes of two potent compounds reveal that, per their design, the novel side groups protrude into the opening to the access channel unoccupied in the enzyme–substrate/exemestane complexes. The observed structure–activity relationship is borne out by the X-ray data. Structure-guided design permits utilization of the aromatase-specific interactions for the development of next generation AIs. PMID:22951074

  15. Isolation and characterization of goat ovarian aromatase cDNA: assessment of the activity using an intact cell system and placental expression.

    PubMed

    Bobes, Raúl José; Miranda, Carolina; Pérez-Martinez, Mario; Luu-The, Van; Romano, Marta C

    2004-08-01

    Goat ovarian follicles produce estrone and estradiol from androgens. The synthesis of C18 estrogens from C19 androgens requires cytochrome P450 aromatase, but little information about this key enzyme is available in the goat. We report here for the first time the cDNA sequence of the goat ovarian aromatase, the activity of the enzyme in a cell system, and its expression in the term goat placenta. A cDNA library from goat ovarian poly(A)+ RNA was constructed. Human aromatase cDNA was selected as probe to screen the library; several clones were isolated, but none was complete. The longest clone was 3.1 kb long, but it lacked the sequence coding for a few amino acids in the NH(2)-terminal. To obtain the missing sequence, we performed reverse amplification of the cDNA end (RACE). Sequence analysis indicated that goat aromatase possessed a very long 3'-untranslated region ( approximately 1790 bp), and a polyadenylation signal (AATAAA) located at position 3320 downstream from the ATG start codon. The coding region of goat cDNA was inserted in an expression vector and transfected into HEK-293 cells that were cultured in presence of [14C]-androstenedione, steroids extracted and further separated by TLC. The transfected cells efficiently transformed [14C]-androstenedione into estrone. This activity was inhibited by 4-hydroxyandrostenedione. We also investigated the presence of mRNA for P450 aromatase in the goat placenta, using reverse transcription-polymerase chain reaction (RT-PCR) and primers derived from the cDNA ovarian sequence and confirmed the expression of the mRNA in term placenta.

  16. Potential effect of Olea europea leaves, Sonchus oleraceus leaves and Mangifera indica peel extracts on aromatase activity in human placental microsomes and CYP19A1 expression in MCF-7 cell line: Comparative study.

    PubMed

    Shaban, N Z; Hegazy, W A; Abdel-Rahman, S M; Awed, O M; Khalil, S A

    2016-01-01

    Aromatase inhibitors (AIs) provide novel approaches to the adjuvant therapy for postmenopausal women with estrogen-receptor-positive (ER+) breast cancers. In this study, different plant extracts from Olea europaea leaves (OLE), Sonchus oleraceus L. (SOE) and Mangifera indica peels (MPE) were prepared to identify phytoconstituents and measure antioxidant capacities. The effects of these three extracts on aromatase activity in human placental microsomes were evaluated. Additionally, the effects of these extracts on tissue-specific promoter expression of CYP19A1 gene in cell culture model (MCF-7) were assessed using qRT-PCR. Results showed a concentration-dependent decrease in aromatase activity after treatment with OLE and MPE, whereas, SOE showed a biphasic effect. The differential effects of OLE, SOE and MPE on aromatase expression showed that OLE seems to be the most potent suppressor followed by SOE and then MPE. These findings indicate that OLE has effective inhibitory action on aromatase at both the enzymatic and expression levels, in addition to its cytotoxic effect against MCF-7 cells. Also, MPE may be has the potential to be used as a tissue-specific aromatase inhibitor (selective aromatase inhibitor) and it may be promising to develop a new therapeutic agent against ER+ breast cancer. PMID:27585256

  17. Kinetic analysis of the three-step steroid aromatase reaction of human cytochrome P450 19A1.

    PubMed

    Sohl, Christal D; Guengerich, F Peter

    2010-06-01

    Cytochrome P450 19A1 (P450 19A1), the aromatase, catalyzes the conversion of androgens to estrogens through a sequential three-step reaction, generating 19-hydroxy and 19-aldehyde intermediates en route to the product estrogen. A procedure for the heterologous expression and purification of P450 19A1 in Escherichia coli was developed (k(cat) of 0.06 s(-1) for the conversion of androstenedione to estrone). Binding of the substrate and intermediates show low micromolar dissociation constants and are at least two-step processes. Rates of reduction of the iron were fast in the presence of substrate, either intermediate, or product. P450 19A1 is a distributive rather than a processive enzyme, with the sequential reaction allowing free dissociation of the intermediates as revealed by pulse-chase experiments. Conversion of androstenedione to estrone (under single turnover conditions) generated a progress curve showing changes in the concentrations of the substrate, intermediates, and product. A minimal kinetic model containing the individual rate constants for the steps in P450 19A1 catalysis was developed to globally fit the time course of the overall reaction, the dissociation constants, the two-step ligand binding, the distributive character, the iron-reduction rates, and the steady-state conversion of the 19-hydroxy androstenedione and 19-aldehyde androstenedione intermediates to estrone. PMID:20385561

  18. Competitive product inhibition of aromatase by natural estrogens.

    PubMed

    Shimizu, Y; Yarborough, C; Osawa, Y

    1993-03-01

    In order to better understand the function of aromatase, we carried out kinetic analyses to assess the ability of natural estrogens, estrone (E1), estradiol (E2), 16 alpha-OHE1, and estriol (E3), to inhibit aromatization. Human placental microsomes (50 micrograms protein) were incubated for 5 min at 37 degrees C with [1 beta-3H]testosterone (1.24 x 10(3) dpm 3H/ng, 35-150 nM) or [1 beta-3H,4-14C]androstenedione (3.05 x 10(3) dpm 3H/ng, 3H/14C = 19.3, 7-65 nM) as substrate in the presence of NADPH, with and without natural estrogens as putative inhibitors. Aromatase activity was assessed by tritium released to water from the 1 beta-position of the substrates. Natural estrogens showed competitive product inhibition against androgen aromatization. The Ki of E1, E2, 16 alpha-OHE1, and E3 for testosterone aromatization was 1.5, 2.2, 95, and 162 microM, respectively, where the Km of aromatase was 61.8 +/- 2.0 nM (n = 5) for testosterone. The Ki of E1, E2, 16 alpha-OHE1, and E3 for androstenedione aromatization was 10.6, 5.5, 252, and 1182 microM, respectively, where the Km of aromatase was 35.4 +/- 4.1 nM (n = 4) for androstenedione. These results show that estrogen inhibit the process of androgen aromatization and indicate that natural estrogens regulate their own synthesis by the product inhibition mechanism in vivo. Since natural estrogen binds to the active site of human placental aromatase P-450 complex as competitive inhibitors, natural estrogens might be further metabolized by aromatase. This suggests that human placental estrogen 2-hydroxylase activity is catalyzed by the active site of aromatase cytochrome P-450 and also agrees with the fact that the level of catecholestrogens in maternal plasma increases during pregnancy. The relative affinities and concentration of androgens and estrogens would control estrogen and catecholestrogen biosynthesis by aromatase.

  19. Structure-activity relationships of phthalates in inhibition of human placental 3β-hydroxysteroid dehydrogenase 1 and aromatase.

    PubMed

    Xu, Ren-Ai; Mao, Baiping; Li, Senlin; Liu, Jianpeng; Li, Xiaojun; Li, Huitao; Su, Ying; Hu, Guoxin; Lian, Qing-Quan; Ge, Ren-Shan

    2016-06-01

    Phthalates are associated with preterm delivery. However, the mechanism is unclear. Progesterone formed by 3β-hydroxysteroid dehydrogenase 1 (HSD3B1) and estradiol by aromatase (CYP19A1) in placenta are critical for maintaining pregnancy. In this study, we compared structure-activity relationships (SAR) of 14 phthalates varied in carbon atoms in alcohol moiety to inhibit human HSD3B1 in COS1 and CYP19A1 in JEG-3 cells. There were responses in that only diphthalates with 4-7 carbon atoms were competitive HSD3B1 inhibitors and diphthalates with 6 carbon atoms were CYP19A1 inhibitors. IC50s of dipentyl (DPP), bis(2-butoxyethyl) (BBOP), dicyclohexyl (DCHP), dibutyl (DBP), and diheptyl phthalate (DHP) were 50.12, 32.41, 31.42, 9.69, and 4.87μM for HSD3B1, respectively. DCHP and BBOP inhibited CYP19A1, with IC50s of 64.70 and 56.47μM. DPP, BBOP, DCHP, DBP, and DHP inhibited progesterone production in JEG-3 cells. In conclusion, our results indicate that there is clear SAR for phthalates in inhibition of HSD3B1 and CYP19A1.

  20. Structural basis for androgen specificity and oestrogen synthesis in human aromatase

    SciTech Connect

    Ghosh, Debashis; Griswold, Jennifer; Erman, Mary; Pangborn, Walter

    2009-03-06

    Aromatase cytochrome P450 is the only enzyme in vertebrates known to catalyse the biosynthesis of all oestrogens from androgens. Aromatase inhibitors therefore constitute a frontline therapy for oestrogen-dependent breast cancer. In a three-step process, each step requiring 1 mol of O{sub 2}, 1 mol of NADPH, and coupling with its redox partner cytochrome P450 reductase, aromatase converts androstenedione, testosterone and 16{alpha}-hydroxytestosterone to oestrone, 17{beta}-oestradiol and 17{beta},16{alpha}-oestriol, respectively. The first two steps are C19-methyl hydroxylation steps, and the third involves the aromatization of the steroid A-ring, unique to aromatase. Whereas most P450s are not highly substrate selective, it is the hallmark androgenic specificity that sets aromatase apart. The structure of this enzyme of the endoplasmic reticulum membrane has remained unknown for decades, hindering elucidation of the biochemical mechanism. Here we present the crystal structure of human placental aromatase, the only natural mammalian, full-length P450 and P450 in hormone biosynthetic pathways to be crystallized so far. Unlike the active sites of many microsomal P450s that metabolize drugs and xenobiotics, aromatase has an androgen-specific cleft that binds the androstenedione molecule snugly. Hydrophobic and polar residues exquisitely complement the steroid backbone. The locations of catalytically important residues shed light on the reaction mechanism. The relative juxtaposition of the hydrophobic amino-terminal region and the opening to the catalytic cleft shows why membrane anchoring is necessary for the lipophilic substrates to gain access to the active site. The molecular basis for the enzyme's androgenic specificity and unique catalytic mechanism can be used for developing next-generation aromatase inhibitors.

  1. The immunoexpression of androgen receptor, estrogen receptors alpha and beta, vanilloid type 1 receptor and cytochrome p450 aromatase in rats testis chronically treated with letrozole, an aromatase inhibitor.

    PubMed

    Pilutin, Anna; Misiakiewicz-Has, Kamila; Kolasa, Agnieszka; Baranowska-Bosiacka, Irena; Marchlewicz, Mariola; Wiszniewska, Barbara

    2014-01-01

    The function of testis is under hormonal control and any disturbance of hormonal homeostasis can lead to morphological and physiological changes. Therefore the aim of the study was to investigate the expression of androgen and estrogen receptors (AR, ERs), vanilloid receptor (TRPV1), cytochrome P450 aromatase (P450arom), as well as apoptosis of cells in testis of adult rats chronically treated with letrozole (LT), a non-steroidal aromatase inhibitor, for 6 months. The testicular tissues were fixed in Bouin's fixative and embedded in paraffin. Immunohistochemistry with monoclonal antibodies (abs) against AR, ERa, P450arom, and polyclonalabs against ERβ, TRPV1, caspase-3 was applied. Long-lasting estradiol deficiency, as an effect of LT treatment, produced changes in the morphology of testis and altered the expression of the studied receptors in cells of the seminiferous tubules and rate of cell apoptosis. The immunostaining for AR was found in the nuclei of Sertoli cells and the cytoplasm of spermatogonia and spermatocytes in III-IV stages of the seminiferous epithelium cycle. The intensity of staining for P450arom was lower in the testis of LT-treated rats as compared to control animals. The immunofluorescence of ERα and ERβ was observed exclusively in the nuclei of Leydig cells of LT-treated rats. There were no changes in localization of TRPV1, however, the intensity of reaction was stronger in germ cells of the seminiferous epithelium after LT treatment. The apoptosis in both groups of animals was observed within the population of spermatocytes and spermatids in II and III stages of the seminiferous epithelium cycle. In testis of LT-treated rats the immunoexpression of caspase-3 was additionally found in the germ cells in I and IV stages, and Sertoli, myoid and Leydig cells. In conclusion, our results underline the important role of letrozole treatment in the proper function of male reproductive system, and additionally demonstrate that hormonal imbalance can

  2. Ontogenic expression patterns of several nuclear receptors and cytochrome P450 aromatases in brain and gonads of the Nile tilapia Oreochromis niloticus suggests their involvement in sex differentiation.

    PubMed

    Sudhakumari, C C; Senthilkumaran, B; Kobayashi, T; Kajiura-Kobayashi, H; Wang, D S; Yoshikuni, M; Nagahama, Y

    2005-04-01

    Using semi-quantitative reverse transcriptase polymerase chain reaction we analyzed the ontogenic expression patterns of several nuclear receptors (estrogen receptors [ERalpha and beta], androgen receptors [ARalpha and beta], Ad4BP/SF-1 and Dax-1) and cytochrome P450 aromatases (brain and ovarian types) in whole brain and gonads of the Nile tilapia. ERalpha and beta transcripts were evident in both sexes with a high expression of ERalpha in females at 0 day after hatching (0 dah). ARalpha appeared early (0 dah) in males and while in females at 25 dah. Among the two types of cytochrome P450 aromatases, the expression of the brain type (bP450arom) but not the ovarian type (oP450arom) was evident from 0 to 90 dah in the whole brain of both males and females. Expression of Ad4BP/SF-1 in female brain began from 0 dah but in male brain at 5 dah. Expression of Dax-1 began at 0 dah and it was higher throughout in male brain than that of the female brain. In gonads, ERalpha and beta transcripts were evident in both sexes with slight variation. In females, both oP450arom and Ad4BP/SF-1 amplicons were evident at 15 dah. In males, although faint expressions of Ad4BP/SF-1 amplicons were evident at early duration of development, oP450arom did not appear until 90 dah. Conversely, expression of bP450arom was observed throughout in the developing testis with varied pattern while in developing ovary it was evident till 15 dah and reappeared only after 90 dah. Taken together, present results suggest that brain acts merely as a synchronizer in the sex differentiation process initiated by gonadal cues/factors in the Nile tilapia.

  3. Brain cytochrome P450 aromatase activity in roach (Rutilus rutilus): seasonal variations and impact of environmental contaminants.

    PubMed

    Geraudie, Perrine; Hinfray, Nathalie; Gerbron, Marie; Porcher, Jean-Marc; Brion, François; Minier, Christophe

    2011-10-01

    P450 aromatase catalyses the conversion of C19 androgens to C18 estrogens which is thought to be essential for the regulation of the reproductive function. In this study, brain aromatase activity (AA) was measured monthly over a reproductive cycle in wild roach (Rutilus rutilus) sampled in a reference site in Normandy. AA peaked during the breeding season, reaching 35 fmol mg(-1)min(-1) in both male and female fish, and was low during the rest of the year except for a significant rise in October. AA was correlated with ovary maturation (measured either as gonado-somatic index or by histological analysis of the gonads) and plasma sex-steroid levels (11-ketotestosterone in males and 17-β-estradiol in females). Measurements of AA in polluted sites showed that activity was significantly upregulated in sites with fish showing high levels of plasma vitellogenin and large proportion of intersexuality (20-50%) thus suggesting the occurrence of estrogenic compounds and their involvement in AA modulation.

  4. Characterization and expression profile of the ovarian cytochrome P-450 aromatase (cyp19A1) gene during thermolabile sex determination in Pejerrey, Odontesthes bonariensis

    USGS Publications Warehouse

    Karube, M.; Fernandino, J.I.; Strobl-Mazzulla, P.; Strussmann, C.A.; Yoshizaki, G.; Somoza, G.M.; Patino, R.

    2007-01-01

    Cytochrome P450 aromatase (cyp19) is an enzyme that catalyzes the conversion of androgens to estrogens and may play a role in temperature- dependent sex determination (TSD) of reptiles, amphibians, and fishes. In this study, the ovarian P450 aromatase form (cyp19A1) of pejerrey Odontesthes bonariensis, a teleost with marked TSD, was cloned and its expression profile evaluated during gonadal differentiation at feminizing (17??C, 100% females), mixed-sex producing (24 and 25??C, 73.3 and 26.7% females, respectively), and masculinizing (29??C, 0% females) temperatures. The deduced cyp19A1 amino acid sequence shared high identity (>77.8%) with that from other teleosts but had low identity (<61.8%) with brain forms (cyp19A2), including that of pejerrey itself. The tissue distribution analysis of cyp19A1 mRNA in adult fish revealed high expression in the ovary. Semi-quantitative reverse transcription polymerase chain reaction analysis of the bodies of larvae revealed that cyp19A1 expression increased before the appearance of the first histological signs of ovarian differentiation at the feminizing temperature but remained low at the masculinizing temperature. The expression levels at mixed-sex producing temperatures were bimodal rather than intermediate, showing low and high modal values similar to those at the feminizing and masculinizing temperatures, respectively. The population percentages of high and low expression levels at intermediate temperatures were proportional to the percentage of females and males, respectively, and high levels were first observed at about the time of sex differentiation of females. These results suggest that cyp19A1 is involved in the process of ovarian formation and possibly also in the TSD of pejerrey. ?? 2007 Wiley-Liss, Inc.

  5. Sex differences, developmental changes, response to injury and cAMP regulation of the mRNA levels of steroidogenic acute regulatory protein, cytochrome p450scc, and aromatase in the olivocerebellar system.

    PubMed

    Lavaque, Esteban; Mayen, Aurora; Azcoitia, Iñigo; Tena-Sempere, Manuel; Garcia-Segura, Luis M

    2006-02-15

    Compelling evidence has now demonstrated direct biological actions of sex steroids at the cerebellum. Likewise, the expression of key steroidogenic factors, such as the steroidogenic acute regulatory protein (StAR), cytochrome P450 side chain cleavage (P450scc), and aromatase, at this neural site has been reported. Little is known, however, about the regulation of their genes in the cerebellum. Assessment of StAR, P450scc, and aromatase mRNAs in the cerebellum of male and female rats revealed that the expression of these genes is developmentally regulated, with the highest levels at early postnatal ages in both sexes and with significantly higher mRNA levels in postnatal males. Expression of these genes in the female remained unaltered after perinatal androgenization and along the estrous cycle. In contrast, damage of cerebellar afferent neurons of the inferior olivary nucleus evoked a significant increase in StAR, P450scc, and aromatase mRNA levels at this site, as well as a transient elevation in StAR mRNA at the cerebellum. Finally, enhancement of cAMP levels in cultured cerebellar neurons induced a significant increase in StAR and aromatase mRNA levels. In summary, we present herein novel evidence for the developmentally regulated and partially sexually dimorphic pattern of expression of StAR, P450scc, and aromatase genes in the rat cerebellum. These observations, together with the finding that the mRNA levels of these steroidogenic molecules are sensitive to injury and are regulated by intracellular cAMP, strongly suggest that local steroidogenesis is likely to play an important role during development and adaptation to neurodegenerative processes in the olivocerebellar system. PMID:16329132

  6. Isolation and characterization of two cytochrome P450 aromatase forms in killifish (Fundulus heteroclitus): differential expression in fish from polluted and unpolluted environments.

    PubMed

    Greytak, Sarah R; Champlin, Denise; Callard, Gloria V

    2005-03-01

    Populations of killifish (Fundulus heteroclitus) persist in many different highly polluted environment indicative of adaptation or tolerance. In this study, we sought to determine whether long term, multigenerational exposures to environmental contaminants has affected reproductively relevant genes and biological processes. A homology cloning strategy was used to isolate the killifish cytochrome P450 aromatase (P450arom, estrogen synthetase) cDNAs. Consistent with previous fish studies, killifish were found to have two P450arom forms, which segregated into A- and B-gene clades and were differentially expressed in brain (B > A) and ovary (A > B). Comparison of killifish from highly polluted (New Bedford Harbor, NBH) and unpolluted (Scorton Creek, SC) environments revealed no site-related differences in P450arom coding sequences or in overall tissue distribution patterns. As measured by real-time quantitative PCR (QPCR) analysis, however, P450arormB (a known marker of estrogen effect) was approximately two-fold higher in the brain of NBH than of SC fish, a difference seen in reproductively active and inactive males and females. Providing further evidence of exposure to estrogen-like pollutants or metabolites in NBH, vitellogenin (vtg) mRNA and protein were elevated in seasonally active and inactive males, and in reproductively inactive females, when compared to SC fish. By contrast, during the period of reproductive activity, NBH females had a lower gonadosomatic index, lower plasma estrogen, a decreased hepatosomatic index, and reduced vtg expression as compared to SC females, indicating that the female hypothalamic-pituitary-gonadal (HPG)-liver axis is impaired in the polluted environment. As measured by a decrease in plasma androgen (but not GSI), the male HPG axis was impaired in reproductively active NBH versus SC fish. In agreement with reports that NBH killifish are resistant to dioxin-like chemicals (DLC) that activate arylhydrocarbon receptor (AhR) signaling

  7. Diverse function of aromatase and the N-terminal sequence deleted form.

    PubMed

    Osawa, Y; Higashiyama, T; Toma, Y; Yarborough, C

    1997-04-01

    The diverse function of human placental aromatase including estradiol 6alpha-hydroxylase and cocaine N-demethylase activity are described, and the mechanism for the simultaneous metabolism of estradiol to 2-hydroxy- and 6alpha-hydroxyestradiol at the same active site of aromatase is postulated. Comparison of aromatase activity is also made among the wild type and N-terminal sequence deleted forms of human aromatase which are recombinantly expressed in Escherichia coli. Aromatase cytochrome P450 was reconstituted and incubated with [6alpha,7alpha-(3)H2,4-(14)C]estradiol, 7-ethoxycoumarin, and [N-methyl-(3)H3]cocaine. 6Alpha-hydroxy[7alpha-(3)H,4-(14)C]estradiol was isolated as the metabolite of estradiol and the 3H-water release method based on the 6alpha-3H label was established. The initial rate kinetics of the 6alpha-hydroxylation gave Km of 4.3 microM, Vmax of 4.02 nmol min(-1) mg(-1), and turnover rate of 0.27 min(-1). Testosterone competed dose-dependently with the 6alpha-hydroxylation and showed the Ki of 0.15 microM, suggesting that they occupy the same binding site of aromatase. The deethylation of 7-ethoxycoumarin showed Km of 200 microM, Vmax of 12.5 nmol min(-1) mg(-1) and turnover rate of 1.06 min(-1). The N-demethylation of cocaine was analysed by the 3H-release method, giving Km of 670 microM, Vmax of 4.76 nmol min(-1) mg(-1), and turnover rate of 0.49 min(-1). All activity was dose-responsively suppressed by anti-aromatase P450 monoclonal antibody MAb3-2C2. The N-terminal 38 amino acid residue deleted form of aromatase P450 was expressed in particularly high yield giving a specific activity of 397 +/- 83 pmol min(-1) mg(-1) (n = 12) of crude membrane-bound particulates with a turnover rate of 2.6 min(-1).

  8. Effect of butyrate on aromatase cytochrome P450 levels in HT29, DLD-1 and LoVo colon cancer cells.

    PubMed

    Rawłuszko, Agnieszka Anna; Sławek, Sylwia; Gollogly, Armin; Szkudelska, Katarzyna; Jagodziński, Paweł Piotr

    2012-03-01

    Epidemiological studies suggest that colonic production of butyrate and estrogen may be involved in human susceptibility to colorectal cancer (CRC). Estrone (E1) can be produced by the aromatase pathway during the conversion of androstenedione (A) to E1. Therefore, we studied the effect of sodium butyrate (NaBu) on the CYP19A1 transcript and protein levels and on the conversion of A to E1 in HT29, DLD-1 and LoVo CRC cells. We found that NaBu significantly downregulated CYP19A1 transcript and protein levels, a phenomenon that was associated with reduced conversion of A to E1 in HT29, DLD-1 and LoVo cells. Our studies demonstrated that, although butyrate exhibited a protective role in CRC development, this compound may reduce aromatase activity and the production of E1 in colon cancer cells.

  9. Modelling inhibition of avian aromatase by azole pesticides

    PubMed Central

    Saxena, A.K.; Devillers, J.; Bhunia, S.S.; Bro, E.

    2015-01-01

    The potential effects of pesticides and their metabolites on the endocrine system are of major concern to wildlife and human health. In this context, the azole pesticides have earned special attention due to their cytochrome P450 aromatase inhibition potential. Cytochrome P450 aromatase (CYP19) catalyses the conversion of androstenedione and testosterone into oestrone and oestradiol, respectively. Thus, aromatase modulates the oestrogenic balance essential not only for females, but also for male physiology, including gonadal function. Its inhibition affects reproductive organs, fertility and sexual behaviour in humans and wildlife species. Several studies have shown that azole pesticides are able to inhibit human and fish aromatases but the information on birds is lacking. Consequently, it appeared to be of interest to estimate the aromatase inhibition of azoles in three different avian species, namely Gallus gallus, Coturnix coturnix japonica and Taeniopygia guttata. In the absence of the crystal structure of the aromatase enzyme in these bird species, homology models for the individual avian species were constructed using the crystal structure of human aromatase (hAr) (pdb: 3EQM) that showed high sequence similarity for G. gallus (82.0%), T. guttata (81.9%) and C. japonica (81.2%). A homology model with Oncorhynchus mykiss (81.9%) was also designed for comparison purpose. The homology-modelled aromatase for each avian and fish species and crystal structure of human aromatase were selected for docking 46 structurally diverse azoles and related compounds. We showed that the docking behaviour of the chemicals on the different aromatases was broadly the same. We also demonstrated that there was an acceptable level of correlation between the binding score values and the available aromatase inhibition data. This means that the homology models derived on bird and fish species can be used to approximate the potential inhibitory effects of azoles on their aromatase. PMID

  10. Aromatase and cyclooxygenases: enzymes in breast cancer.

    PubMed

    Brueggemeier, Robert W; Richards, Jeanette A; Petrel, Trevor A

    2003-09-01

    Aromatase (estrogen synthase) is the cytochrome P450 enzyme complex that converts C19 androgens to C18 estrogens. Aromatase activity has been demonstrated in breast tissue in vitro, and expression of aromatase is highest in or near breast tumor sites. Thus, local regulation of aromatase by both endogenous factors as well as exogenous medicinal agents will influence the levels of estrogen available for breast cancer growth. The prostaglandin PGE2 increases intracellular cAMP levels and stimulates estrogen biosynthesis, and previous studies in our laboratories have shown a strong linear association between aromatase (CYP19) expression and expression of the cyclooxygenases (COX-1 and COX-2) in breast cancer specimens. To further investigate the pathways regulating COX and CYP19 gene expression, studies were performed in normal breast stromal cells, in breast cancer cells from patients, and in breast cancer cell lines using selective pharmacological agents. Enhanced COX enzyme levels results in increased production of prostaglandins, such as PGE2. This prostaglandin increased aromatase activity in breast stromal cells, and studies with selective agonists and antagonists showed that this regulation of signaling pathways occurs through the EP1 and EP2 receptor subtypes. COX-2 gene expression was enhanced in breast cancer cell lines by ligands for the various peroxisome proliferator-activated receptors (PPARs), and differential regulation was observed between hormone-dependent and -independent breast cancer cells. Thus, the regulation of both enzymes in breast cancer involves complex paracrine interactions, resulting in significant consequences on the pathogenesis of breast cancer. PMID:14623550

  11. Developmental regulation of aromatase activity in the rat hypothalamus

    SciTech Connect

    Lephart, E.D.

    1989-01-01

    The brain of all mammalian species studied thus far contain an enzymatic activity (aromatase) that catalyzes the conversion of androgens to estrogens. The activity is highest during prenatal development and contributes to the establishment of sex differences which determine adult gonadotropin secretion patterns and reproductive behavior. The studies presented in this dissertation represent a systematic effort to elucidate the mechanism(s) that control the initiation of and contribute to maintaining rat hypothalamic aromatase activity during pre- and postnatal development. Aromatase enzyme activity was measured by the {sup 3}H{sub 2}O release assay or by traditional estrogen product isolation. Brain aromatase mRNA was detected by hybridization to a cDNA encoding rat aromatase cytochrome P-450. In both males and females the time of puberty was associated with a decline in hypothalamic aromatase activity. This decline may represent a factor underlying the peri-pubertal decrease in the sensitivity to gonadal steroid feedback that accompanies completion of puberty. The results also indicate that androgens regulate brain aromatase levels during both the prepubertal and peri-pubertal stages of sexual development and that this regulation is transiently lost in young adults. Utilizing a hypothalamic organotypic culture system, aromatase activity in vitro was maintained for as long as two days. The results of studies of a variety of hormonal and metabolic regulators suggest that prenatal aromatase activity is regulated by factor(s) that function independently from the classical cyclic AMP and protein kinase C trans-membrane signaling pathways.

  12. Effects of aminoglutethiumide and its metabolite, N-acetylaminoglutethimide, on bovine adrenocortical and human placental cytochromes P-450scc.

    PubMed

    Sheets, J J; Vickery, L E

    1982-10-01

    The ability of aminoglutethimide to inhibit cholesterol conversion to pregnenolone was lost upon acetylation of the arylamine nitrogen. This appears to be due to failure of N-acetyl-d-aminoglutethimide to bind to cytochrome P-450scc, since it does not produce the altered low spin form of the enzyme formed upon binding of d-aminoglutethimide. These findings provide further evidence for a role of the free arenamine function in aminoglutethimide and related inhibitors.

  13. Design and Synthesis of Norendoxifen Analogues with Dual Aromatase Inhibitory and Estrogen Receptor Modulatory Activities

    PubMed Central

    Lv, Wei; Liu, Jinzhong; Skaar, Todd C.; Flockhart, David A.; Cushman, Mark

    2015-01-01

    Both selective estrogen receptor modulators and aromatase inhibitors are widely used for the treatment of breast cancer. Compounds with both aromatase inhibitory and estrogen receptor modulatory activities could have special advantages for treatment of breast cancer. Our previous efforts led to the discovery of norendoxifen as the first compound with dual aromatase inhibitory and estrogen receptor binding activities. To optimize its efficacy and aromatase selectivity versus other cytochrome P450 enzymes, a series of structurally related norendoxifen analogues were designed and synthesized. The most potent compound, 4'-hydroxynorendoxifen (10), displayed elevated inhibitory potency against aromatase and enhanced affinity for estrogen receptors when compared to norendoxifen. The selectivity of 10 for aromatase versus other cytochrome P450 enzymes was also superior to norendoxifen. 4'-Hydroxynorendoxifen is therefore an interesting lead for further development to obtain new anticancer agents of potential value for the treatment of breast cancer. PMID:25751283

  14. Effect of low dose exposure to the herbicide atrazine and its metabolite on cytochrome P450 aromatase and steroidogenic factor-1 mRNA levels in the brain of premetamorphic bullfrog tadpoles (Rana catesbeiana)

    PubMed Central

    Gunderson, Mark P.; Veldhoen, Nik; Skirrow, Rachel C.; Macnab, Magnus K.; Ding, Wei; van Aggelen, Graham; Helbing, Caren C.

    2011-01-01

    The transcriptional regulator steroidogenic factor 1 (SF-1) and the enzyme cytochrome P450 aromatase (CYP19) play a central role in modulation of a broad range of tissue-specific developmental processes associated with hormone homeostasis that includes differentiation of the central nervous system. SF-1 and CYP19 expression may be targeted by a variety of endocrine disruptive agents prevalent within the environment. In the present study, we cloned and characterized partial sequences for bullfrog (Rana catesbeiana) SF-1 and CYP19 and examined the effects of a 48 h exposure to 1 and 100 μg/L of the herbicide atrazine (ATZ) and its major metabolite desethylatrazine (DEA), as well as 5 ng/L of the estrogenic chemical, 17α-ethynylestradiol (EE2), and 673 ng/L of the thyroid hormone, 3,5, 3′-triiodothyronine (T3), on SF-1 and CYP19 mRNA abundance in the brains of premetamorphic bullfrog tadpoles. Quantitative RT-PCR analysis showed an increase in CYP19 mRNA following a 48 h exposure to EE2 but not T3 while no significant changes in SF-1 transcript levels occurred. We observed a strong positive correlation between CYP19 and SF-1 transcript abundance in the ATZ-exposed animals which was not evident with DEA- or hormone-exposed tadpoles. Our results are intriguing in light of reported behavioral changes in ATZ-exposed frogs and suggest that further research is warranted to examine the relationship and role of CYP19 and SF-1 in amphibian brain development. PMID:21371610

  15. Effect of low dose exposure to the herbicide atrazine and its metabolite on cytochrome P450 aromatase and steroidogenic factor-1 mRNA levels in the brain of premetamorphic bullfrog tadpoles (Rana catesbeiana).

    PubMed

    Gunderson, Mark P; Veldhoen, Nik; Skirrow, Rachel C; Macnab, Magnus K; Ding, Wei; van Aggelen, Graham; Helbing, Caren C

    2011-03-01

    The transcriptional regulator steroidogenic factor 1 (SF-1) and the enzyme cytochrome P450 aromatase (CYP19) play a central role in modulation of a broad range of tissue-specific developmental processes associated with hormone homeostasis that includes differentiation of the central nervous system. SF-1 and CYP19 expression may be targeted by a variety of endocrine disruptive agents prevalent within the environment. In the present study, we cloned and characterized partial sequences for bullfrog (Rana catesbeiana) SF-1 and CYP19 and examined the effects of a 48h exposure to 1 and 100μg/l of the herbicide atrazine (ATZ) and its major metabolite desethylatrazine (DEA), as well as 5ng/l of the estrogenic chemical, 17α-ethynylestradiol (EE(2)), and 673ng/l of the thyroid hormone, 3,5,3'-triiodothyronine (T(3)), on SF-1 and CYP19 mRNA abundance in the brains of premetamorphic bullfrog tadpoles. Quantitative RT-PCR analysis showed an increase in CYP19 mRNA following a 48h exposure to EE(2) but not T(3) while no significant changes in SF-1 transcript levels occurred. We observed a strong positive correlation between CYP19 and SF-1 transcript abundance in the ATZ-exposed animals which was not evident with DEA- or hormone-exposed tadpoles. Our results are intriguing in light of reported behavioral changes in ATZ-exposed frogs and suggest that further research is warranted to examine the relationship and role of CYP19 and SF-1 in amphibian brain development.

  16. Integrated approach to explore the mechanisms of aromatase inhibition and recovery in fathead minnows (Pimephales promelas)

    EPA Science Inventory

    Aromatase, a member of the cytochrome P450 superfamily, is a key enzyme in estradiol synthesis that catalyzes the aromatization of androgens into estrogens in ovaries. Here, we used an integrated approach to assess the mechanistic basis of the direct effects of aromatase inhibiti...

  17. Mechanism-based Categorization of Aromatase Inhibitors: A Potential Discovery and Screening Tool

    EPA Science Inventory

    Cytochrome P450 aromatase is a key steroidogenic enzyme that converts androgens to estrogens in vertebrates. There is much interest in aromatase inhibitors (AIs) because a number of environmental contaminants can act as AIs, thereby disrupting endocrine function in humans and wil...

  18. Catalytic efficiency of expressed aromatase following site-directed mutagenesis.

    PubMed

    Kadohama, N; Zhou, D; Chen, S; Osawa, Y

    1993-05-13

    Mutant aromatase cytochrome P-450s, expressed in CHO cells after transfection with cDNAs, have been characterized in terms of their catalytic efficiencies. After solubilization from microsomes, specific aromatase P-450 content of wild-type and mutants Pro308Phe, Asp309Asn, Asp309Ala and Phe406Arg was quantitated by a sandwich enzyme-linked immunosorbent assay (ELISA). Microsomal aromatase activity was determined by the 3H-water method using [1 beta-3H]androstenedione as substrate. Estimations of the actual turnover rate (catalytic efficiency) were derived from the combined data. The P-450 content in the mutants varied but was always less than that in the wild type. Hence, the decreases in the Vmax observed in the mutant enzymes did not correlate completely with reductions in catalytic effectiveness. In recent studies on the structure-function relationship of aromatase cytochrome P-450, the observed reduction of enzyme activity in terms of Vmax following site-directed mutagenesis led to the assumption that there was a corresponding loss of catalytic effectiveness. The present study reveals that a lower P-450 content can contribute significantly to decreasing catalytic activity in the mutants. In fact, in mutant Phe406Arg which exhibited virtually no catalytically active aromatase, the specific P-450 content was below the detectable level. Because of its location, the result of this latter mutation could be a major structural perturbation of the heme-binding property. Thus, interpretation of losses and reductions in aromatase activity resulting from single amino-acid replacement should take into account changes in the specific content of aromatase cytochrome P-450.

  19. Presence of aromatase inhibitors in cycads.

    PubMed

    Kowalska, M T; Itzhak, Y; Puett, D

    1995-07-28

    Cycads, the most primitive of the living gymnosperms, have been used and continue to be used for food and medicinal purposes by many cultures, although toxins must be removed before ingestion. In our quest to identify tropical plants that contain inhibitors of the cytochrome P-450 aromatase and thus may be efficacious in treating estrogen-dependent tumors, we have screened extracts from 5 species of cycad folia encompassing 3 genera: Cycas cairnsiana F. Muell., Cycas revoluta Thunb., Cycas rumphii Miq., Dioon spinulosum Dyer and Encephalartos ferox Bertol. All extracts were found to contain inhibitors of the human enzyme.

  20. Effects of a short-term exposure to the aromatase inhibitor fadrozole on steroid production and gene expression in the ovary of female fathead minnows (Pimephales promelas)

    EPA Science Inventory

    Cytochrome P450 aromatase is a steriodogenic enzyme that converts C19 androgens to C18 estrogens and is critical for normal reproduction in females. Fadrozole is a well-studied aromatase inhibitor that has been shown to suppress estrogen production in the ovaries of fish. Howev...

  1. Screening of selected pesticides for inhibition of CYP19 aromatase activity in vitro.

    PubMed

    Vinggaard, A M; Hnida, C; Breinholt, V; Larsen, J C

    2000-06-01

    Many pesticides are able to block or activate the steroid hormone receptors and/or to affect the levels of sex hormones, thereby potentially affecting the development or expression of the male and female reproductive system or both. This emphasizes the relevance of screening pesticides for a wide range of hormone-mimicking effects. Twenty-two pesticides were tested for their ability to affect CYP19 aromatase activity in human placental microsomes using the classical [(3)H](2)O method. Prochloraz, imazalil, propioconazole, fenarimol, triadimenol, triadimefon (all fungicides), and dicofol (an acaricide) gave rise to a statistically significant inhibition of aromatase activity. The IC(50)s of prochloraz, imazalil, propioconazole fenarimol, triadimenol, and triadimefon were calculated from dose-response curves to be 0.04, 0.34, 6.5, 10, 21 and 32 microM, respectively. The IC(50) of dicofol was greater than 50 microM. The positive control 4-hydroxyandrostendione (1 microM) caused an inhibition of aromatase activity by 74%. The compounds, which did not affect the aromatase activity, were bromopropylate, chlorfenvinphos, chlorobenzilate, chlorpyrifos, diuron, heptachlor, iprodion, linuron, pentachlorphenol, procymidon, propyzamide, quintozen, tetrachlorvinphos and tetradifon. With the purpose of comparing the results for fenarimol obtained with the microsomal system with data from an intact cell system, an aromatase assay based on JEG-3 cells was established. 4-Hydroxyandrostendione (1 microM) inhibited the aromatase activity in JEG-3 cells by 94%. The IC(50) for fenarimol in this system was 2 microM, slightly lower than that observed in the microsomal system. For the first time, fenarimol has been demonstrated to inhibit aromatase activity in human tissues and, furthermore, propioconazole, triadimefon, and triadimenol were identified as weak aromatase inhibitors. In conclusion, seven out of 22 tested pesticides turned out to be weak to moderate aromatase inhibitors in

  2. Placental insufficiency

    MedlinePlus

    ... mother is as healthy as possible during the pregnancy. Smoking, alcohol, and other recreational drugs can interfere with the baby's growth. Avoiding these substances may help prevent placental insufficiency and other pregnancy complications.

  3. Modulation of Aromatase by Phytoestrogens

    PubMed Central

    Lephart, Edwin D.

    2015-01-01

    The aromatase enzyme catalyzes the conversion of androgens to estrogens in many human tissues. Estrogens are known to stimulate cellular proliferation associated with certain cancers and protect against adverse symptoms during the peri- and postmenopausal intervals. Phytoestrogens are a group of plant derived naturally occurring compounds that have chemical structures similar to estrogen. Since phytoestrogens are known to be constituents of animal/human food sources, these compounds have received increased research attention. Phytoestrogens may contribute to decreased cancer risk by the inhibition of aromatase enzyme activity and CYP19 gene expression in human tissues. This review covers (a) the aromatase enzyme (historical descriptions on function, activity, and gene characteristics), (b) phytoestrogens in their classifications and applications to human health, and (c) a chronological coverage of aromatase activity modulated by phytoestrogens from the early 1980s to 2015. In general, phytoestrogens act as aromatase inhibitors by (a) decreasing aromatase gene expression, (b) inhibiting the aromatase enzyme itself, or (c) in some cases acting at both levels of regulation. The findings presented herein are consistent with estrogen's impact on health and phytoestrogen's potential as anticancer treatments, but well-controlled, large-scale studies are warranted to determine the effectiveness of phytoestrogens on breast cancer and age-related diseases. PMID:26798508

  4. Aromatase Inhibitors and Other Compounds for Lowering Breast Cancer Risk

    MedlinePlus

    ... References Aromatase inhibitors and other compounds for lowering breast cancer risk Aromatase inhibitors (drugs that lower estrogen levels) ... day. Can aromatase inhibitors lower the risk of breast cancer? Aromatase inhibitors are used mainly to treat hormone ...

  5. Evolution of suiform aromatases: ancestral duplication with conservation of tissue-specific expression in the collared peccary (Pecari tayassu).

    PubMed

    Corbin, C J; Hughes, A L; Heffelfinger, J R; Berger, T; Waltzek, T B; Roser, J F; Santos, T C; Miglino, M A; Oliveira, M F; Braga, F C; Meirelles, F V; Conley, A J

    2007-10-01

    Aromatase cytochrome P450 (P450arom), the enzyme that catalyzes estrogen synthesis, is required for successful reproduction and is encoded by a single copy gene (CYP19) in most mammals. However, pigs and their distant suiform relatives the peccaries experienced CYP19 duplication. Here, the evolutionary origin of CYP19 duplication, and the evolution of the gene paralogs, was explored further in collared peccaries (Pecari tayassu). Exons IV and V, and the intervening intron, representing duplicated CYP19 genes, were cloned and sequenced from collared peccary, pig, and hippopotamus. Sequence alignment and analysis identified a gene conversion in collared peccary with a breakpoint 102 base pairs (bp) upstream of exon V. Phylogenetic analyses of nucleotide and amino acid sequence upstream of the breakpoint supported a tree in which one peccary sequence was orthologous with the porcine gonadal gene. Cloning and sequencing of tissue transcripts, using reverse-transcriptase polymerase chain reaction techniques (RT-PCR), confirmed that the gonadal ortholog was expressed in collared peccary testis. Orthology of the other genomic sequence with the porcine placental gene was not resolved, but its placenta-specific expression in collared peccary was confirmed by similar transcript analysis. Immunoblot and enzyme activity in collared peccary testes demonstrated much lower levels of P450arom than in pig testis. Collared peccary placental P450arom expression also seemed much lower than pigs. Thus, suiform CYP19 genes arose from an ancestral duplication that has maintained gonad- and placenta-specific expression, but at lower levels in peccaries than pigs, perhaps facilitating the emergence of different reproductive strategies as Suiformes diverged and evolved. PMID:17912474

  6. Inhibitory Aromatase Effects of Flavonoids from Ginkgo Biloba Extracts on Estrogen Biosynthesis.

    PubMed

    Park, Yong Joo; Choo, Wun Hak; Kim, Ha Ryong; Chung, Kyu Hyuck; Oh, Seung Min

    2015-01-01

    Ginkgo biloba extract (GBE) is a popular phytomedicine and has been used for disorders of the central nervous system, cardiovascular, renal, respiratory, and circulatory diseases. Although GBE is a complex mixture of over 300 compounds, its major components are 24% flavonoids and 6% terpene lactones. In this study, we tested the inhibitory effects of the three major flavonoids (kaempferol, quercetin, and isorhamnetin) from GBE, independently and as mixtures, on aromatase activity using JEG-3 cells (human placental cells) and recombinant proteins (human placental microsome). In both systems, kaempferol showed the strongest inhibitory effects among the three flavonoids; the flavanoid mixtures exerted increased inhibitory effects. The results of exon I.1-driven luciferase reporter gene assays supported the increased inhibitory effects of flavonoid mixtures, accompanied by suppression of estrogen biosynthesis. In the RT-PCR analysis, decreased patterns of aromatase promoter I.1 mRNA expressions were observed, which were similar to the aromatase inhibition patterns of flavonoids and their mixtures. The present study demonstrated that three flavonoids synergistically inhibit estrogen biosynthesis through aromatase inhibition, decrease CYP19 mRNA, and induce transcriptional suppression. Our results support the usefulness of flavonoids in adjuvant therapy for breast cancer by reducing estrogen levels with reduced adverse effects due to estrogen depletion. PMID:26434836

  7. Neuroprotective Actions of Brain Aromatase

    PubMed Central

    Saldanha, Colin J.; Duncan, Kelli A.; Walters, Bradley J.

    2009-01-01

    The steroidal regulation of vertebrate neuroanatomy and neurophysiology includes a seemingly unending list of brain areas, cellular structures and behaviors modulated by these hormones. Estrogens, in particular have emerged as potent neuromodulators, exerting a range of effects including neuroprotection and perhaps neural repair. In songbirds and mammals, the brain itself appears to be the site of injury-induced estrogen synthesis via the rapid transcription and translation of aromatase (estrogen synthase) in astroglia. This induction seems to occur regardless of the nature and location of primary brain damage. The induced expression of aromatase apparently elevates local estrogen levels enough to interfere with apoptotic pathways, thereby decreasing secondary degeneration and ultimately lessening the extent of damage. There is even evidence suggesting that aromatization may affect injury-induced cytogenesis. Thus, aromatization in the brain appears to confer neuroprotection by an array of mechanisms that involve the deceleration and acceleration of degeneration and repair respectively. We are only beginning to understand the factors responsible for the injury-induced transcription of aromatase in astroglia. In contrast, much of the manner in which local and circulating estrogens may achieve their neuroprotective effects has been elucidated. However, gaps in our knowledge include issues about the cell-specific regulation of aromatase expression, steroidal influences of aromatization distinct from estrogen formation, and questions about the role of constitutive aromatase in neuroprotection. Here we describe the considerable consensus and some interesting differences in knowledge gained from studies conducted on diverse animal models, experimental paradigms and preparations towards understanding the neuroprotective actions of brain aromatase. PMID:19450619

  8. Selective inhibition of aromatase by a dihydroisocoumarin from Xyris pterygoblephara.

    PubMed

    Endringer, Denise C; Guimarães, Keller G; Kondratyuk, Tamara P; Pezzuto, John M; Braga, Fernão C

    2008-06-01

    Aromatase is a well-established target for the chemoprevention of breast cancer. The dihydroisocoumarin (3 R,4 R)-(-)-6-methoxy-1-oxo-3-pentyl-3,4-dihydro-1 H-isochromen-4-yl acetate (1) (IC 50 = 1.6 +/- 0.1 microM), isolated from aerial parts of Xyris pterygoblephara, showed aromatase inhibitory activity. The specificity of 1 was evaluated by inhibition assays with cytochrome P450 enzymes. CYP1A1 was inhibited modestly (IC 50 = 38.0 +/- 2.0 microM), while CYP2C8 and CYP3A4 enzymes were not affected. Dihydroisocoumarin 1 showed weak antiproliferative activity against MCF-7 (IC 50 = 66.9 +/- 2.3 microM) and LNCaP (IC 50 = 57.5 +/- 2.0 microM) cells and was inactive against LU-1 and HepG2 cells in culture. These results demonstrate the potential of dihydroisocoumarin 1 to serve as a selective aromatase inhibitor. PMID:18462007

  9. The genomic environment around the Aromatase gene: evolutionary insights

    PubMed Central

    Castro, L Filipe C; Santos, Miguel M; Reis-Henriques, Maria A

    2005-01-01

    Background The cytochrome P450 aromatase (CYP19), catalyses the aromatisation of androgens to estrogens, a key mechanism in vertebrate reproductive physiology. A current evolutionary hypothesis suggests that CYP19 gene arose at the origin of vertebrates, given that it has not been found outside this clade. The human CYP19 gene is located in one of the proposed MHC-paralogon regions (HSA15q). At present it is unclear whether this genomic location is ancestral (which would suggest an invertebrate origin for CYP19) or derived (genomic location with no evolutionary meaning). The distinction between these possibilities should help to clarify the timing of the CYP19 emergence and which taxa should be investigated. Results Here we determine the "genomic environment" around CYP19 in three vertebrate species Homo sapiens, Tetraodon nigroviridis and Xenopus tropicalis. Paralogy studies and phylogenetic analysis of six gene families suggests that the CYP19 gene region was structured through "en bloc" genomic duplication (as part of the MHC-paralogon formation). Four gene families have specifically duplicated in the vertebrate lineage. Moreover, the mapping location of the different paralogues is consistent with a model of "en bloc" duplication. Furthermore, we also determine that this region has retained the same gene content since the divergence of Actinopterygii and Tetrapods. A single inversion in gene order has taken place, probably in the mammalian lineage. Finally, we describe the first invertebrate CYP19 sequence, from Branchiostoma floridae. Conclusion Contrary to previous suggestions, our data indicates an invertebrate origin for the aromatase gene, given the striking conservation pattern in both gene order and gene content, and the presence of aromatase in amphioxus. We propose that CYP19 duplicated in the vertebrate lineage to yield four paralogues, followed by the subsequent loss of all but one gene in vertebrate evolution. Finally, we suggest that agnathans and

  10. Cytotoxic effects and aromatase inhibition by xenobiotic endocrine disrupters alone and in combination

    SciTech Connect

    Benachour, Nora; Moslemi, Safa; Sipahutar, Herbert; Seralini, Gilles-Eric . E-mail: criigen@unicaen.fr

    2007-07-15

    Xenobiotics may cause long-term adverse effects in humans, especially at the embryonic level, raising questions about their levels of exposure, combined effects, and crucial endpoints. We are interested in the possible interactions between xenobiotic endocrine disrupters, cellular viability and androgen metabolism. Accordingly, we tested aroclor 1254 (A1254), atrazine (AZ), o,p'-DDT, vinclozolin (VZ), p,p'-DDE, bisphenol A (BPA), chlordecone (CD), nonylphenol (NP), tributylin oxide (TBTO), and diethylstilbestrol (DES) for cellular toxicity against human embryonic 293 cells, and activity against cellular aromatase, but also on placental microsomes and on the purified equine enzyme. Cellular viability was affected in 24 h by all the xenobiotics with a threshold at 50 {mu}M (except for TBTO and DES, 10 {mu}M threshold), and aromatase was inhibited at non-toxic doses. In combination synergism was observed reducing the threshold values of toxicity to 4-10 {mu}M, and aromatase activity by 50% in some cases. In placental microsomes the most active xenobiotics rapidly inhibited microsomal aromatase in a manner independent of NADPH metabolism. Prolonged exposures to low doses in cells generally amplified by 50 times aromatase inhibition. These xenobiotics may act by inhibition of the active site or by allosteric effects on the enzyme. Bioaccumulation is a feature of some xenobiotics, especially chlordecone, DDT and DDE, and low level chronic exposures can also affect cell signaling mechanisms. This new information about the mechanism of action of these xenobiotics will assist in improved molecular design with a view to providing safer compounds for use in the (human) environment.

  11. EVALUATION OF THE AROMATASE INHIBITOR FADROZOLE IN A SHORT-TERM REPRODUCTION ASSAY WITH THE FATHEAD MINNOW (PIMEPHALES PROMELAS)

    EPA Science Inventory

    Cytochrome P450 aromatase is a key enzyme in vertebrate steroidogenesis, catalyzing the conversion of C19 androgens to C18 estrogens such a B-estradiol (E2). The objective of this study was to assess effects of the CYP inhibitor fadrozole on fathead minnow reproductive endocrinol...

  12. Anti-aromatase chemicals in red wine.

    PubMed

    Eng, E T; Williams, D; Mandava, U; Kirma, N; Tekmal, R R; Chen, S

    2002-06-01

    Estrogen synthesized in situ plays a more important role in breast cancer cell proliferation than does circulating estrogen. Aromatase is the enzyme that converts androgen to estrogen and is expressed at a higher level in breast cancer tissue than in surrounding noncancer tissue. A promising route of chemoprevention against breast cancer may be through the suppression of in situ estrogen formation using aromatase inhibitors. A diet high in fruits and vegetables may reduce the incidence of breast cancer, because they contain phytochemicals that can act as aromatase inhibitors. In our previous studies, we found that grapes and wine contain potent phytochemicals that can inhibit aromatase. We show that red wine was more effective than white wine in suppressing aromatase activity. Interestingly, our results from white wine studies suggest a weak inductive effect of alcohol on aromatase activity. On the other hand, the potent effect of anti-aromatase chemicals in red wine overcomes the weak inductive effect of alcohol in wine. Several purification procedures were performed on whole red wine to separate active aromatase inhibitors from non-active compounds. These techniques included liquid-liquid extraction, silica gel chromatography, various solid phase extraction (SPE) columns, and high performance liquid chromatography. An active Pinot Noir red wine SPE C18 column fraction (20% acetonitrile:water) was more effective than complete Pinot Noir wine in suppressing aromatase assay. This red wine extract was further analyzed in a transgenic mouse model in which aromatase was over-expressed in mammary tissue. Our gavaged red wine extract completely abrogated aromatase-induced hyperplasia and other neoplastic changes in mammary tissue. These results suggest that red wine or red wine extract may be a chemopreventive diet supplement for postmenopausal women who have a high risk of breast cancer. Further research is underway to purify and characterize the active compounds in red

  13. Natural Products as Aromatase Inhibitors

    PubMed Central

    Balunas, Marcy J.; Su, Bin; Brueggemeier, Robert W.; Kinghorn, A. Douglas

    2010-01-01

    With the clinical success of several synthetic aromatase inhibitors (AIs) in the treatment of postmenopausal estrogen receptor-positive breast cancer, researchers have also been investigating also the potential of natural products as AIs. Natural products from terrestrial and marine organisms provide a chemically diverse array of compounds not always available through current synthetic chemistry techniques. Natural products that have been used traditionally for nutritional or medicinal purposes (e.g., botanical dietary supplements) may also afford AIs with reduced side effects. A thorough review of the literature regarding natural product extracts and secondary metabolites of plant, microbial, and marine origin that have been shown to exhibit aromatase inhibitory activity is presented herein. PMID:18690828

  14. Aromatase Inhibition in a Transcriptional Network Context

    EPA Science Inventory

    A variety of chemicals in the environment have the potential to inhibit aromatase, an enzyme critical to estrogen synthesis. We examined the responses of female fathead minnow ovaries (FHM, Pimephales promelas) to a model aromatase inhibitor, fadrozole, using a transcriptional ne...

  15. Transgenic Chickens Overexpressing Aromatase Have High Estrogen Levels but Maintain a Predominantly Male Phenotype.

    PubMed

    Lambeth, Luke S; Morris, Kirsten R; Wise, Terry G; Cummins, David M; O'Neil, Terri E; Cao, Yu; Sinclair, Andrew H; Doran, Timothy J; Smith, Craig A

    2016-01-01

    Estrogens play a key role in sexual differentiation of both the gonads and external traits in birds. The production of estrogen occurs via a well-characterized steroidogenic pathway, which is a multistep process involving several enzymes, including cytochrome P450 aromatase. In chicken embryos, the aromatase gene (CYP19A1) is expressed female-specifically from the time of gonadal sex differentiation. Ectopic overexpression of aromatase in male chicken embryos induces gonadal sex reversal, and male embryos treated with estradiol become feminized; however, this is not permanent. To test whether a continuous supply of estrogen in adult chickens could induce stable male to female sex reversal, 2 transgenic male chickens overexpressing aromatase were generated using the Tol2/transposase system. These birds had robust ectopic aromatase expression, which resulted in the production of high serum levels of estradiol. Transgenic males had female-like wattle and comb growth and feathering, but they retained male weights, displayed leg spurs, and developed testes. Despite the small sample size, this data strongly suggests that high levels of circulating estrogen are insufficient to maintain a female gonadal phenotype in adult birds. Previous observations of gynandromorph birds and embryos with mixed sex chimeric gonads have highlighted the role of cell autonomous sex identity in chickens. This might imply that in the study described here, direct genetic effects of the male chromosomes largely prevailed over the hormonal profile of the aromatase transgenic birds. This data therefore support the emerging view of at least partial cell autonomous sex development in birds. However, a larger study will confirm this intriguing observation. PMID:26556534

  16. Transgenic Chickens Overexpressing Aromatase Have High Estrogen Levels but Maintain a Predominantly Male Phenotype.

    PubMed

    Lambeth, Luke S; Morris, Kirsten R; Wise, Terry G; Cummins, David M; O'Neil, Terri E; Cao, Yu; Sinclair, Andrew H; Doran, Timothy J; Smith, Craig A

    2016-01-01

    Estrogens play a key role in sexual differentiation of both the gonads and external traits in birds. The production of estrogen occurs via a well-characterized steroidogenic pathway, which is a multistep process involving several enzymes, including cytochrome P450 aromatase. In chicken embryos, the aromatase gene (CYP19A1) is expressed female-specifically from the time of gonadal sex differentiation. Ectopic overexpression of aromatase in male chicken embryos induces gonadal sex reversal, and male embryos treated with estradiol become feminized; however, this is not permanent. To test whether a continuous supply of estrogen in adult chickens could induce stable male to female sex reversal, 2 transgenic male chickens overexpressing aromatase were generated using the Tol2/transposase system. These birds had robust ectopic aromatase expression, which resulted in the production of high serum levels of estradiol. Transgenic males had female-like wattle and comb growth and feathering, but they retained male weights, displayed leg spurs, and developed testes. Despite the small sample size, this data strongly suggests that high levels of circulating estrogen are insufficient to maintain a female gonadal phenotype in adult birds. Previous observations of gynandromorph birds and embryos with mixed sex chimeric gonads have highlighted the role of cell autonomous sex identity in chickens. This might imply that in the study described here, direct genetic effects of the male chromosomes largely prevailed over the hormonal profile of the aromatase transgenic birds. This data therefore support the emerging view of at least partial cell autonomous sex development in birds. However, a larger study will confirm this intriguing observation.

  17. X-ray structure of human aromatase reveals an androgen-specific active site.

    PubMed

    Ghosh, Debashis; Griswold, Jennifer; Erman, Mary; Pangborn, Walter

    2010-02-28

    Aromatase is a unique cytochrome P450 that catalyzes the removal of the 19-methyl group and aromatization of the A-ring of androgens for the synthesis of estrogens. All human estrogens are synthesized via this enzymatic aromatization pathway. Aromatase inhibitors thus constitute a frontline therapy for estrogen-dependent breast cancer. Despite decades of intense investigation, this enzyme of the endoplasmic reticulum membrane has eluded all structure determination efforts. We have determined the crystal structure of the highly active aromatase purified from human placenta, in complex with its natural substrate androstenedione. The structure shows the binding mode of androstenedione in the catalytically active oxidized high-spin ferric state of the enzyme. Hydrogen bond-forming interactions and tight packing hydrophobic side chains that complement the puckering of the steroid backbone provide the molecular basis for the exclusive androgenic specificity of aromatase. Locations of catalytic residues and water molecules shed new light on the mechanism of the aromatization step. The structure also suggests a membrane integration model indicative of the passage of steroids through the lipid bilayer.

  18. Aromatase inhibitors in the treatment of endometriosis

    PubMed Central

    Męczekalski, Błażej

    2016-01-01

    Endometriosis is a chronic inflammatory condition in which foci of endometrial tissue grow outside of the uterine cavity. Endometriosis was estimated to affect 176 million women of childbearing potential all over the world in 2010. The presence of extrauterine endometrial tissue is associated with pain and infertility. Typical symptoms of endometriosis include dysmenorrhoea, dyspareunia, heavy menstrual periods (menorrhagia), pelvic pain that is not related to menstrual cycles, dysuria, and chronic fatigue. Medical treatments for endometriosis include combined oral contraceptive pills, danazol, gestrinone, medroxyprogesterone acetate, and gonadotropin-releasing hormone agonists (aGnRHs). A new class of medications called aromatase inhibitors has been identified in recent years as potential therapeutic agents for endometriosis. This article provides general information about aromatase inhibitors, their use in gynaecology, and their adverse effects. In particular, the paper discusses the use of aromatase inhibitors in the treatment of endometriosis in postmenopausal women. Unlike oral contraceptives, gestagens, aGnRHs, and danazol, which suppress ovarian oestrogen synthesis, aromatase inhibitors inhibit mainly extra-ovarian synthesis of oestrogens. Therefore, the use of aromatase inhibitors seems to be particularly relevant in older patients, as most of the body's oestrogen is produced outside the ovaries after menopause. The paper discusses also the use of aromatase inhibitors in the treatment of pain associated with endometriosis and infertility caused by endometriosis. PMID:27095958

  19. Aromatase inhibitors in the treatment of endometriosis.

    PubMed

    Słopień, Radosław; Męczekalski, Błażej

    2016-03-01

    Endometriosis is a chronic inflammatory condition in which foci of endometrial tissue grow outside of the uterine cavity. Endometriosis was estimated to affect 176 million women of childbearing potential all over the world in 2010. The presence of extrauterine endometrial tissue is associated with pain and infertility. Typical symptoms of endometriosis include dysmenorrhoea, dyspareunia, heavy menstrual periods (menorrhagia), pelvic pain that is not related to menstrual cycles, dysuria, and chronic fatigue. Medical treatments for endometriosis include combined oral contraceptive pills, danazol, gestrinone, medroxyprogesterone acetate, and gonadotropin-releasing hormone agonists (aGnRHs). A new class of medications called aromatase inhibitors has been identified in recent years as potential therapeutic agents for endometriosis. This article provides general information about aromatase inhibitors, their use in gynaecology, and their adverse effects. In particular, the paper discusses the use of aromatase inhibitors in the treatment of endometriosis in postmenopausal women. Unlike oral contraceptives, gestagens, aGnRHs, and danazol, which suppress ovarian oestrogen synthesis, aromatase inhibitors inhibit mainly extra-ovarian synthesis of oestrogens. Therefore, the use of aromatase inhibitors seems to be particularly relevant in older patients, as most of the body's oestrogen is produced outside the ovaries after menopause. The paper discusses also the use of aromatase inhibitors in the treatment of pain associated with endometriosis and infertility caused by endometriosis. PMID:27095958

  20. Signaling pathways regulating aromatase and cyclooxygenases in normal and malignant breast cells.

    PubMed

    Richards, Jeanette A; Petrel, Trevor A; Brueggemeier, Robert W

    2002-02-01

    Aromatase (estrogen synthase) is the cytochrome P450 enzyme complex that converts C(19) androgens to C(18) estrogens. Aromatase activity has been demonstrated in breast tissue in vitro, and expression of aromatase is highest in or near breast tumor sites. Thus, local regulation of aromatase by both endogenous factors as well as exogenous medicinal agents will influence the levels of estrogen available for breast cancer growth. The prostaglandin PGE(2) increases intracellular cAMP levels and stimulates estrogen biosynthesis, and our recent studies have shown a strong linear association between CYP19 expression and the sum of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) expression in breast cancer specimens. Knowledge of the signaling pathways that regulate the expression and enzyme activity of aromatase and cyclooxygenases (COXs) in stromal and epithelial breast cells will aid in understanding the interrelationships of these two enzyme systems and potentially identify novel targets for regulation. The effects of epidermal growth factor (EGF), transforming growth factor-beta (TGFbeta), and tetradecanoyl phorbol acetate (TPA) on aromatase and COXs were studied in primary cultures of normal human adipose stromal cells and in cell cultures of normal immortalized human breast epithelial cells MCF-10F, estrogen-responsive human breast cancer cells MCF-7, and estrogen-unresponsive human breast cancer cells MDA-MB-231. Levels of the constitutive COX isozyme, COX-1, were not altered by the various treatments in the cell systems studied. In breast adenocarcinoma cells, EGF and TGFbeta did not alter COX-2 levels at 24h, while TPA induced COX-2 levels by 75% in MDA-MB-231 cells. EGF and TPA in MCF-7 cells significantly increased aromatase activity while TGFbeta did not. In contrast to MCF-7 cells, TGFbeta and TPA significantly increased activity in MDA-MB-231 cells, while only a modest increase with EGF was observed. Untreated normal adipose stromal cells exhibited

  1. Pharmacophore modeling and in silico screening for new P450 19 (aromatase) inhibitors.

    PubMed

    Schuster, Daniela; Laggner, Christian; Steindl, Theodora M; Palusczak, Anja; Hartmann, Rolf W; Langer, Thierry

    2006-01-01

    Cytochrome P450 19 (P450 19, aromatase) constitutes a successful target for the treatment of breast cancer. This study analyzes chemical features common to P450 19 inhibitors to develop ligand-based, selective pharmacophore models for this enzyme. The HipHop and HypoRefine algorithms implemented in the Catalyst software package were employed to create both common feature and quantitative models. The common feature model for P450 19 includes two ring aromatic features in its core and two hydrogen bond acceptors at the ends. The models were used as database search queries to identify active compounds from the NCI database. PMID:16711749

  2. Pharmacophore modeling and in silico screening for new P450 19 (aromatase) inhibitors.

    PubMed

    Schuster, Daniela; Laggner, Christian; Steindl, Theodora M; Palusczak, Anja; Hartmann, Rolf W; Langer, Thierry

    2006-01-01

    Cytochrome P450 19 (P450 19, aromatase) constitutes a successful target for the treatment of breast cancer. This study analyzes chemical features common to P450 19 inhibitors to develop ligand-based, selective pharmacophore models for this enzyme. The HipHop and HypoRefine algorithms implemented in the Catalyst software package were employed to create both common feature and quantitative models. The common feature model for P450 19 includes two ring aromatic features in its core and two hydrogen bond acceptors at the ends. The models were used as database search queries to identify active compounds from the NCI database.

  3. Oestrogen reporter transgenic medaka for non-invasive evaluation of aromatase activity.

    PubMed

    Spirhanzlova, Petra; Leleu, Mathilde; Sébillot, Anthony; Lemkine, Gregory F; Iguchi, Taisen; Demeneix, Barbara A; Tindall, Andrew J

    2016-01-01

    Vertebrate reproduction involves complex steroid hormone interplay and inter-conversion. A critical element in maintaining sex steroid levels is the enzyme aromatase (cytochrome P450 19A1) which converts androgens to oestrogens. In turn oestrogen signalling is targeted by numerous chemicals, from pharmaceuticals to agricultural chemicals, both frequent sources of contamination in waste waters and consequently rivers. Although many models are now available to address disruption of oestrogen signalling, there are currently no published protocols allowing discrimination between alterations in testosterone metabolism and in oestrogenic signalling. It was with this limitation in mind that we optimised this protocol. We show using a 48h protocol that pre-feeding fry of the choriogenin h-gfp (chgh-gfp) medaka line are sensitive to 0.05nM EE2 (15ng/L), within the range of the lowest published observable physiological effect concentrations for medaka. In addition, co-treatment with testosterone can reveal potential effects of test substances on aromatase enzymatic activity. As the measurements are visualised in real-time without affecting embryo viability, repeated measures are possible. We demonstrate the ability of this model to detect oestrogen receptor agonists, aromatisable androgens, P450 aromatase activity modulators and selective oestrogen response modulators. Importantly, the range of this assay is physiologically relevant. PMID:26352216

  4. Diagnosis of placental malaria.

    PubMed

    Mockenhaupt, Frank P; Ulmen, Ulrike; von Gaertner, Christiane; Bedu-Addo, George; Bienzle, Ulrich

    2002-01-01

    In a group of 596 delivering Ghanaian women, the sensitivities of peripheral blood thick film microscopy, ICT Malaria P.f/P.v test, and PCR in detecting microscopically confirmed placental Plasmodium falciparum infection were 42, 80, and 97%, respectively. In addition to the gross underestimation of placental malaria by peripheral blood film microscopy, submicroscopic infections were found to be a risk factor for maternal anemia.

  5. Combination effects of (tri)azole fungicides on hormone production and xenobiotic metabolism in a human placental cell line.

    PubMed

    Rieke, Svenja; Koehn, Sophie; Hirsch-Ernst, Karen; Pfeil, Rudolf; Kneuer, Carsten; Marx-Stoelting, Philip

    2014-09-01

    Consumers are exposed to multiple residues of different pesticides via the diet. Therefore, EU legislation for pesticides requires the evaluation of single active substances as well as the consideration of combination effects. Hence the analysis of combined effects of substances in a broad dose range represents a key challenge to current experimental and regulatory toxicology. Here we report evidence for additive effects for (tri)azole fungicides, a widely used group of antifungal agents, in the human placental cell line Jeg-3. In addition to the triazoles cyproconazole, epoxiconazole, flusilazole and tebuconazole and the azole fungicide prochloraz also pesticides from other chemical classes assumed to act via different modes of action (i.e., the organophosphate chlorpyrifos and the triazinylsulfonylurea herbicide triflusulfuron-methyl) were investigated. Endpoints analysed include synthesis of steroid hormone production (progesterone and estradiol) and gene expression of steroidogenic and non-steroidogenic cytochrome-P-450 (CYP) enzymes. For the triazoles and prochloraz, a dose dependent inhibition of progesterone production was observed and additive effects could be confirmed for several combinations of these substances in vitro. The non-triazoles chlorpyrifos and triflusulfuron-methyl did not affect this endpoint and, in line with this finding, no additivity was observed when these substances were applied in mixtures with prochloraz. While prochloraz slightly increased aromatase expression and estradiol production and triflusulfuron-methyl decreased estradiol production, none of the other substances had effects on the expression levels of steroidogenic CYP-enzymes in Jeg-3 cells. For some triazoles, prochloraz and chlorpyrifos a significant induction of CYP1A1 mRNA expression and potential combination effects for this endpoint were observed. Inhibition of CYP1A1 mRNA induction by the AhR inhibitor CH223191 indicated AhR receptor dependence this effect. PMID

  6. Direct Regulation of Aromatase B Expression by 17β-Estradiol and Dopamine D1 Receptor Agonist in Adult Radial Glial Cells

    PubMed Central

    Xing, Lei; Esau, Crystal; Trudeau, Vance L.

    2016-01-01

    Aromatase cytochrome P450arom (cyp19) is the only enzyme that has the ability to convert androgens into estrogens. Estrogens, which are produced locally in the vertebrate brain play many fundamental roles in neuroendocrine functions, reproductive functions, socio-sexual behaviors, and neurogenesis. Radial glial cells (RGCs) are neuronal progenitor cells that are abundant in fish brains and are the exclusive site of aromatase B expression and neuroestrogen synthesis. Using a novel in vitro RGC culture preparation we studied the regulation of aromatase B by 17β-estradiol (E2) and dopamine (DA). We have established that activation of the dopamine D1 receptor (D1R) by SKF 38393 up-regulates aromatase B gene expression most likely through the phosphorylation of cyclic AMP response element binding protein (CREB). This up-regulation can be enhanced by low concentration of E2 (100 nM) through increasing the expression of D1R and the level of p-CREB protein. However, a high concentration of E2 (1 μM) and D1R agonist together failed to up-regulate aromatase B, potentially due to attenuation of esr2b expression and p-CREB levels. Furthermore, we found the up-regulation of aromatase B by E2 and DA both requires the involvement of esr1 and esr2a. The combined effect of E2 and DA agonist indicates that aromatase B in the adult teleost brain is under tight control by both steroids and neurotransmitters to precisely regulate neuroestrogen levels. PMID:26793050

  7. Effects of chloro-s-triazine herbicides and metabolites on aromatase activity in various human cell lines and on vitellogenin production in male carp hepatocytes.

    PubMed Central

    Sanderson, J T; Letcher, R J; Heneweer, M; Giesy, J P; van den Berg, M

    2001-01-01

    We investigated a potential mechanism for the estrogenic properties of three chloro-s-triazine herbicides and six metabolites in vitro in several cell systems. We determined effects on human aromatase (CYP19), the enzyme that converts androgens to estrogens, in H295R (adrenocortical carcinoma), JEG-3 (placental choriocarcinoma), and MCF-7 (breast cancer) cells; we determined effects on estrogen receptor-mediated induction of vitellogenin in primary hepatocyte cultures of adult male carp (Cyprinus carpio). In addition to atrazine, simazine, and propazine, two metabolites--atrazine-desethyl and atrazine-desisopropyl--induced aromatase activity in H295R cells concentration-dependently (0.3-30 microM) and with potencies similar to those of the parent triazines. After a 24-hr exposure to 30 microM of the triazines, an apparent maximum induction of about 2- to 2.5-fold was achieved. The induction responses were confirmed by similar increases in CYP19 mRNA levels, determined by reverse-transcriptase polymerase chain reaction. In JEG-3 cells, where basal aromatase expression is about 15-fold greater than in H295R cells, the induction responses were similar but less pronounced; aromatase expression in MCF-7 cells was neither detectable nor inducible under our culture conditions. The fully dealkylated metabolite atrazine-desethyl-desisopropyl and the three hydroxylated metabolites (2-OH-atrazine-desethyl, -desisopropyl, and -desethyl-desisopropyl) did not induce aromatase activity. None of the triazine herbicides nor their metabolites induced vitellogenin production in male carp hepatocytes; nor did they antagonize the induction of vitellogenin by 100 nM (EC(50) 17beta-estradiol. These findings together with other reports indicate that the estrogenic effects associated with the triazine herbicides in vivo are not estrogen receptor-mediated, but may be explained partly by their ability to induce aromatase in vitro. PMID:11675267

  8. Aromatase inhibiting and combined estrogenic effects of parabens and estrogenic effects of other additives in cosmetics

    SciTech Connect

    Meeuwen, J.A. van Son, O. van; Piersma, A.H.; Jong, P.C. de; Berg, M. van den

    2008-08-01

    There is concern widely on the increase in human exposure to exogenous (anti)estrogenic compounds. Typical are certain ingredients in cosmetic consumer products such as musks, phthalates and parabens. Monitoring a variety of human samples revealed that these ingredients, including the ones that generally are considered to undergo rapid metabolism, are present at low levels. In this in vitro research individual compounds and combinations of parabens and endogenous estradiol (E{sub 2}) were investigated in the MCF-7 cell proliferation assay. The experimental design applied a concentration addition model (CA). Data were analyzed with the estrogen equivalency (EEQ) and method of isoboles approach. In addition, the catalytic inhibitory properties of parabens on an enzyme involved in a rate limiting step in steroid genesis (aromatase) were studied in human placental microsomes. Our results point to an additive estrogenic effect in a CA model for parabens. In addition, it was found that parabens inhibit aromatase. Noticeably, the effective levels in both our in vitro systems were far higher than the levels detected in human samples. However, estrogenic compounds may contribute in a cumulative way to the circulating estrogen burden. Our calculation for the extra estrogen burden due to exposure to parabens, phthalates and polycyclic musks indicates an insignificant estrogenic load relative to the endogenous or therapeutic estrogen burden.

  9. Aromatase inhibiting and combined estrogenic effects of parabens and estrogenic effects of other additives in cosmetics.

    PubMed

    van Meeuwen, J A; van Son, O; Piersma, A H; de Jong, P C; van den Berg, M

    2008-08-01

    There is concern widely on the increase in human exposure to exogenous (anti)estrogenic compounds. Typical are certain ingredients in cosmetic consumer products such as musks, phthalates and parabens. Monitoring a variety of human samples revealed that these ingredients, including the ones that generally are considered to undergo rapid metabolism, are present at low levels. In this in vitro research individual compounds and combinations of parabens and endogenous estradiol (E(2)) were investigated in the MCF-7 cell proliferation assay. The experimental design applied a concentration addition model (CA). Data were analyzed with the estrogen equivalency (EEQ) and method of isoboles approach. In addition, the catalytic inhibitory properties of parabens on an enzyme involved in a rate limiting step in steroid genesis (aromatase) were studied in human placental microsomes. Our results point to an additive estrogenic effect in a CA model for parabens. In addition, it was found that parabens inhibit aromatase. Noticeably, the effective levels in both our in vitro systems were far higher than the levels detected in human samples. However, estrogenic compounds may contribute in a cumulative way to the circulating estrogen burden. Our calculation for the extra estrogen burden due to exposure to parabens, phthalates and polycyclic musks indicates an insignificant estrogenic load relative to the endogenous or therapeutic estrogen burden.

  10. Aromatase inhibitors in men: effects and therapeutic options

    PubMed Central

    2011-01-01

    Aromatase inhibitors effectively delay epiphysial maturation in boys and improve testosterone levels in adult men Therefore, aromatase inhibitors may be used to increase adult height in boys with gonadotropin-independent precocious puberty, idiopathic short stature and constitutional delay of puberty. Long-term efficacy and safety of the use of aromatase inhibitors has not yet been established in males, however, and their routine use is therefore not yet recommended. PMID:21693046

  11. Paternal Retrieval Behavior Regulated by Brain Estrogen Synthetase (Aromatase) in Mouse Sires that Engage in Communicative Interactions with Pairmates

    PubMed Central

    Akther, Shirin; Huang, Zhiqi; Liang, Mingkun; Zhong, Jing; Fakhrul, Azam A. K. M.; Yuhi, Teruko; Lopatina, Olga; Salmina, Alla B.; Yokoyama, Shigeru; Higashida, Chiharu; Tsuji, Takahiro; Matsuo, Mie; Higashida, Haruhiro

    2015-01-01

    Parental behaviors involve complex social recognition and memory processes and interactive behavior with children that can greatly facilitate healthy human family life. Fathers play a substantial role in child care in a small but significant number of mammals, including humans. However, the brain mechanism that controls male parental behavior is much less understood than that controlling female parental behavior. Fathers of non-monogamous laboratory ICR mice are an interesting model for examining the factors that influence paternal responsiveness because sires can exhibit maternal-like parental care (retrieval of pups) when separated from their pups along with their pairmates because of olfactory and auditory signals from the dams. Here we tested whether paternal behavior is related to femininity by the aromatization of testosterone. For this purpose, we measured the immunoreactivity of aromatase [cytochrome P450 family 19 (CYP19)], which synthesizes estrogen from androgen, in nine brain regions of the sire. We observed higher levels of aromatase expression in these areas of the sire brain when they engaged in communicative interactions with dams in separate cages. Interestingly, the number of nuclei with aromatase immunoreactivity in sires left together with maternal mates in the home cage after pup-removing was significantly larger than that in sires housed with a whole family. The capacity of sires to retrieve pups was increased following a period of 5 days spent with the pups as a whole family after parturition, whereas the acquisition of this ability was suppressed in sires treated daily with an aromatase inhibitor. The results demonstrate that the dam significantly stimulates aromatase in the male brain and that the presence of the pups has an inhibitory effect on this increase. These results also suggest that brain aromatization regulates the initiation, development, and maintenance of paternal behavior in the ICR male mice. PMID:26696812

  12. Synthesis and PET studies of [11C-cyano]letrozole (Femara), an aromatase inhibitor drug

    SciTech Connect

    kil K. E.; Biegon A.; Kil, K.-E.; Biegon, A.; Ding, Y.-S.; Fischer, A.; Ferrieri, R.A.; Kim, S.-W.; Pareto, D.; Schueller, M.J.; Fowler, J.S.

    2008-11-10

    Aromatase, a member of the cytochrome P450 family, converts androgens such as androstenedione and testosterone to estrone and estradiol respectively. Letrozole (1-[bis-(4-cyanophenyl)methyl]-1H-1,2,4-triazole, Femara{reg_sign}) is a high affinity aromatase inhibitor (K{sub i}=11.5 nM) which has FDA approval for breast cancer treatment. Here we report the synthesis of carbon-11 labeled letrozole and its assessment as a radiotracer for brain aromatase in the baboon. Letrozole and its precursor (4-[(4-bromophenyl)-1H-1,2,4-triazol-1-ylmethyl]benzonitrile, 3) were prepared in two-step syntheses from 4-cyanobenzyl bromide and 4-bromobenzyl bromide, respectively. The [{sup 11}C]cyano group was introduced via the tetrakis(triphenylphosphine)palladium(0) catalyzed coupling of [{sup 11}C]cyanide with the bromo-precursor (3). PET studies in the baboon brain were carried out to assess regional distribution and kinetics, reproducibility of repeated measures and saturability. The free fraction of letrozole in the plasma, log D, and the [{sup 11}C-cyano]letrozole fraction in the arterial plasma were also measured. [{sup 11}C-cyano]Letrozole was synthesized in 60 min with a radiochemical yield of 79-80%, with a radiochemical purity greater than 98% and a specific activity of 4.16 {+-} 2.21 Ci/{micro}mol at the end of bombardment (n=4). PET studies in the baboon revealed initial rapid and high uptake and initial rapid clearance followed by slow clearance of carbon-11 from the brain with no difference between brain regions. The brain kinetics was not affected by co-injection of unlabeled letrozole (0.1 mg/kg). The free fraction of letrozole in plasma was 48.9% and log D was 1.84. [{sup 11}C-cyano]Letrozole is readily synthesized via a palladium catalyzed coupling reaction with [{sup 11}C]cyanide. Although it is unsuitable as a PET radiotracer for brain aromatase as revealed by the absence of regional specificity and saturability in brain regions, such as amygdala, which are known

  13. Melatonin modulates aromatase activity and expression in endothelial cells.

    PubMed

    Alvarez-García, Virginia; González, Alicia; Martínez-Campa, Carlos; Alonso-González, Carolina; Cos, Samuel

    2013-05-01

    Melatonin is known to suppress the development of endocrine-responsive breast cancers by interacting with the estrogen signaling pathways. Paracrine interactions between malignant epithelial cells and proximal stromal cells are responsible for local estrogen biosynthesis. In human breast cancer cells and peritumoral adipose tissue, melatonin downregulates aromatase, which transforms androgens into estrogens. The presence of aromatase on endothelial cells indicates that endothelial cells may contribute to tumor growth by producing estrogens. Since human umbilical vein endothelial cells (HUVECs) express both aromatase and melatonin receptors, the aim of the present study was to evaluate the ability of melatonin to regulate the activity and expression of aromatase on endothelial cells, thus, modulating local estrogen biosynthesis. In the present study, we demonstrated that melatonin inhibits the growth of HUVECs and reduces the local biosynthesis of estrogens through the downregulation of aromatase. These results are supported by three lines of evidence. Firstly, 1 mM of melatonin counteracted the testosterone-induced cell proliferation of HUVECs, which is dependent on the local biosynthesis of estrogens from testosterone by the aromatase activity of the cells. Secondly, we found that 1 mM of melatonin reduced the aromatase activity of HUVECs. Finally, by real‑time RT-PCR, we demonstrated that melatonin significantly downregulated the expression of aromatase as well as its endothelial-specific aromatase promoter region I.7. We conclude that melatonin inhibits aromatase activity and expression in HUVECs by regulating gene expression of specific aromatase promoter regions, thereby reducing the local production of estrogens. PMID:23450505

  14. Aromatase deficiency in a Chinese adult man caused by novel compound heterozygous CYP19A1 mutations: Effects of estrogen replacement therapy on the bone, lipid, liver and glucose metabolism

    PubMed Central

    Chen, Zhike; Wang, Ou; Nie, Min; Elison, Kathleen; Zhou, Dujin; Li, Mei; Jiang, Yan; Xia, Weibo; Meng, Xunwu; Chen, Shiuan; Xing, Xiaoping

    2015-01-01

    Objectives Aromatase deficiency is a rare disorder resulting in estrogen insufficiency in humans. It has been reported in remarkably few men with loss-of-function mutations in the CYP19A1 gene encoding the aromatase, a cytochrome P450 enzyme that plays a crucial role in the biosynthesis of estrogens from androgens. We investigated a non-consanguineous family including an adult man with clinical features of aromatase deficiency, and studied the effects of estrogen replacement in the man. Methods We investigated the clinical and biochemical phenotype, performed CYP19A1 mutational analysis in the family and 50 unrelated persons, studied the effects of CYP19A1 mutations on aromatase protein structure, functionally characterized the mutations by cell-based aromatase activity assays, and studied the effects of estrogen replacement on the bone, lipid, liver and glucose metabolism. Results The man with clinical features of aromatase deficiency had novel compound heterozygous CYP19A1 mutations (Y81C and L451P) that were not found in 50 unrelated persons. Three-dimensional modeling predicted that Y81C and L451P mutants disrupted protein structure. Functional studies on the basis of in vitro expression showed that Y81C and L45P mutants significantly decreased the aromatase activity and catalytic efficiency. Estrogen replacement in the man increased bone mineral density, accelerated bone maturation, improved lipid profile and liver steatosis, and improved glucose levels but not insulin resistance. Conclusions We have identified two novel CYP19A1 missense mutations in an aromatase-deficient man. Estrogen replacement in the man shows great impact on recovering the impairments in the bone, lipid, liver and glucose metabolism, but fails to improve insulin resistance. PMID:25301327

  15. Cytochrome P450 differences in normal and imposex-affected female whelk Buccinum undatum from the open North Sea.

    PubMed

    Santos, M M; ten Hallers-Tjabbes, C C; Vieira, N; Boon, J P; Porte, C

    2002-01-01

    Normal and imposex-affected female Buccinum undatum were sampled from the open North Sea at three locations, one with low, and two with high shipping densities. Cytochrome P450 components and P450 aromatase activity were determined in the microsomal fractions isolated from pooled digestive gland/gonads. Cytochrome P450 aromatase activity was significantly higher (P < 0.05) in normal females collected in the low shipping density area (1,325 +/- 295 fmol/h/mg protein) than levels from imposex animals from a high shipping density area (620 +/- 287 fmol/h/mg protein). A negative correlation was found between aromatase activity and organotin body burden (r = -0.99). Levels of CYP450, cytochrome b5 and NADPH cytochrome c reductase activity did not show differences among groups. This is the first field evidence of depressed aromatase activity in imposex affected females, although additional research under laboratory controlled conditions is required to fully understand the mechanisms underlying the development of imposex in this species.

  16. Aromatase Inhibitors in the Treatment of Short Stature.

    PubMed

    Hero, Matti

    2016-01-01

    Reports published in the 1990s of men with estrogen deficiency caused by defective aromatase or estrogen resistance due to a defective estrogen receptor α confirmed the crucial role of estrogen in bone maturation, closure of the epiphyses and cessation of statural growth. Based on these findings, it became reasonable to postulate that selective inhibition of estrogen synthesis with aromatase inhibitors could increase adult height by delaying bone maturation and prolonging the period of growth in males. To date, aromatase inhibitors have been employed in rare pediatric conditions associated with sex steroid excess, and in randomized controlled trials involving boys with short stature and/or constitutional delay of puberty. Findings from these randomized trials suggest that potent aromatase inhibitors increase predicted height, but final adult height data are scarce. Moreover, several safety issues remain inadequately studied. In this paper, published findings on the use of aromatase inhibitors in growth indications are reviewed with emphasis on treatment efficacy and safety.

  17. Natural Product Compounds with Aromatase Inhibitory Activity: An Update

    PubMed Central

    Balunas, Marcy J.; Kinghorn, A. Douglas

    2010-01-01

    Several synthetic aromatase inhibitors are currently in clinical use for the treatment of postmenopausal women with hormone-receptor positive breast cancer. However, these treatments may lead to untoward side effects and so a search for new aromatase inhibitors continues, especially those for which the activity is promoter-specific, targeting the breast-specific promoters I.3 and II. Recently, numerous natural product compounds have been found to inhibit aromatase in non-cellular, cellular, and in vivo studies. These investigations, covering the last two years, as well as additional studies that have focused on the evaluation of natural product compounds as promoter-specific aromatase inhibitors or as aromatase inducers, are described in this review. PMID:20635310

  18. Direct Effects, Compensation, and Recovery in Female Fathead Minnows Exposed to a Model Aromatase Inhibitor

    PubMed Central

    Villeneuve, Daniel L.; Mueller, Nathaniel D.; Martinović, Dalma; Makynen, Elizabeth A.; Kahl, Michael D.; Jensen, Kathleen M.; Durhan, Elizabeth J.; Cavallin, Jenna E.; Bencic, David; Ankley, Gerald T.

    2009-01-01

    Background Several chemicals in the environment have the potential to inhibit aromatase, an enzyme critical to estrogen synthesis. Objectives The objective of this study was to provide a detailed characterization of molecular and biochemical responses of female fathead minnows to a model aromatase inhibitor, fadrozole (FAD). Methods Fish were exposed via water to 0, 3, or 30 μg FAD/L for 8 days and then held in clean water for 8 days, with samples collected at four time points during each 8-day period. We quantified ex vivo steroid production, plasma steroids, and plasma vitellogenin (Vtg) concentrations and analyzed relative transcript abundance of 10 key regulatory genes in ovaries and 3 in pituitary tissue by real-time polymerase chain reaction. Results Ex vivo 17β-estradiol (E2) production and plasma E2 and Vtg concentrations were significantly reduced after a single day of exposure to 3 μg or 30 μg FAD/L. However, plasma E2 concentrations recovered by the eighth day of exposure in the 3-μg/L group and within 1 day of cessation of exposure in the 30-μg/L group, indicating concentration- and time-dependent physiologic compensation and recovery. Concentration-dependent increases in transcripts coding for aromatase (A isoform), cytochrome P450 side-chain cleavage, steroidogenic acute regulatory protein, and follicle-stimulating hormone receptor all coincided with increased E2 production and recovery of plasma E2 concentrations. Conclusions Results of this research highlight the need to consider compensation/adaptation and recovery when developing and interpreting short-term bioassays or biomarkers or when trying to predict the effects of chemical exposures based on mode of action. PMID:19440503

  19. Origin of aromatase inhibitory activity via proteochemometric modeling.

    PubMed

    Simeon, Saw; Spjuth, Ola; Lapins, Maris; Nabu, Sunanta; Anuwongcharoen, Nuttapat; Prachayasittikul, Virapong; Wikberg, Jarl E S; Nantasenamat, Chanin

    2016-01-01

    Aromatase, the rate-limiting enzyme that catalyzes the conversion of androgen to estrogen, plays an essential role in the development of estrogen-dependent breast cancer. Side effects due to aromatase inhibitors (AIs) necessitate the pursuit of novel inhibitor candidates with high selectivity, lower toxicity and increased potency. Designing a novel therapeutic agent against aromatase could be achieved computationally by means of ligand-based and structure-based methods. For over a decade, we have utilized both approaches to design potential AIs for which quantitative structure-activity relationships and molecular docking were used to explore inhibitory mechanisms of AIs towards aromatase. However, such approaches do not consider the effects that aromatase variants have on different AIs. In this study, proteochemometrics modeling was applied to analyze the interaction space between AIs and aromatase variants as a function of their substructural and amino acid features. Good predictive performance was achieved, as rigorously verified by 10-fold cross-validation, external validation, leave-one-compound-out cross-validation, leave-one-protein-out cross-validation and Y-scrambling tests. The investigations presented herein provide important insights into the mechanisms of aromatase inhibitory activity that could aid in the design of novel potent AIs as breast cancer therapeutic agents. PMID:27190705

  20. Weight gain increases human aromatase expression in mammary gland.

    PubMed

    Chen, Dong; Zhao, Hong; Coon, John S; Ono, Masanori; Pearson, Elizabeth K; Bulun, Serdar E

    2012-05-15

    Adulthood weight gain predicts estrogen receptor-positive breast cancer. Because local estrogen excess in the breast likely contributes to cancer development, and aromatase is the key enzyme in estrogen biosynthesis, we investigated the role of local aromatase expression in weight gain-associated breast cancer risk in a humanized aromatase (Arom(hum)) mouse model containing the coding region and the 5'-regulatory region of the human aromatase gene. Compared with littermates on normal chow, female Arom(hum) mice on a high fat diet gained more weight, and had a larger mammary gland mass with elevated total human aromatase mRNA levels via promoters I.4 and II associated with increased levels of their regulators TNFα and C/EBPβ. There was no difference in total human aromatase mRNA levels in gonadal white adipose tissue. Our data suggest that diet-induced weight gain preferentially stimulates local aromatase expression in the breast, which may lead to local estrogen excess and breast cancer risk.

  1. Origin of aromatase inhibitory activity via proteochemometric modeling

    PubMed Central

    Simeon, Saw; Spjuth, Ola; Lapins, Maris; Nabu, Sunanta; Anuwongcharoen, Nuttapat; Prachayasittikul, Virapong; Wikberg, Jarl E.S.

    2016-01-01

    Aromatase, the rate-limiting enzyme that catalyzes the conversion of androgen to estrogen, plays an essential role in the development of estrogen-dependent breast cancer. Side effects due to aromatase inhibitors (AIs) necessitate the pursuit of novel inhibitor candidates with high selectivity, lower toxicity and increased potency. Designing a novel therapeutic agent against aromatase could be achieved computationally by means of ligand-based and structure-based methods. For over a decade, we have utilized both approaches to design potential AIs for which quantitative structure–activity relationships and molecular docking were used to explore inhibitory mechanisms of AIs towards aromatase. However, such approaches do not consider the effects that aromatase variants have on different AIs. In this study, proteochemometrics modeling was applied to analyze the interaction space between AIs and aromatase variants as a function of their substructural and amino acid features. Good predictive performance was achieved, as rigorously verified by 10-fold cross-validation, external validation, leave-one-compound-out cross-validation, leave-one-protein-out cross-validation and Y-scrambling tests. The investigations presented herein provide important insights into the mechanisms of aromatase inhibitory activity that could aid in the design of novel potent AIs as breast cancer therapeutic agents. PMID:27190705

  2. Origin of aromatase inhibitory activity via proteochemometric modeling.

    PubMed

    Simeon, Saw; Spjuth, Ola; Lapins, Maris; Nabu, Sunanta; Anuwongcharoen, Nuttapat; Prachayasittikul, Virapong; Wikberg, Jarl E S; Nantasenamat, Chanin

    2016-01-01

    Aromatase, the rate-limiting enzyme that catalyzes the conversion of androgen to estrogen, plays an essential role in the development of estrogen-dependent breast cancer. Side effects due to aromatase inhibitors (AIs) necessitate the pursuit of novel inhibitor candidates with high selectivity, lower toxicity and increased potency. Designing a novel therapeutic agent against aromatase could be achieved computationally by means of ligand-based and structure-based methods. For over a decade, we have utilized both approaches to design potential AIs for which quantitative structure-activity relationships and molecular docking were used to explore inhibitory mechanisms of AIs towards aromatase. However, such approaches do not consider the effects that aromatase variants have on different AIs. In this study, proteochemometrics modeling was applied to analyze the interaction space between AIs and aromatase variants as a function of their substructural and amino acid features. Good predictive performance was achieved, as rigorously verified by 10-fold cross-validation, external validation, leave-one-compound-out cross-validation, leave-one-protein-out cross-validation and Y-scrambling tests. The investigations presented herein provide important insights into the mechanisms of aromatase inhibitory activity that could aid in the design of novel potent AIs as breast cancer therapeutic agents.

  3. Malignant cancer and invasive placentation

    PubMed Central

    D'Souza, Alaric W.; Wagner, Günter P.

    2014-01-01

    Cancer metastasis is an invasive process that involves the transplantation of cells into new environments. Since human placentation is also invasive, hypotheses about a relationship between invasive placentation in eutherian mammals and metastasis have been proposed. The relationship between metastatic cancer and invasive placentation is usually presented in terms of antagonistic pleiotropy. According to this hypothesis, evolution of invasive placentation also established the mechanisms for cancer metastasis. Here, in contrast, we argue that the secondary evolution of less invasive placentation in some mammalian lineages may have resulted in positive pleiotropic effects on cancer survival by lowering malignancy rates. These positive pleiotropic effects would manifest themselves as resistance to cancer cell invasion. To provide a preliminary test of this proposal, we re-analyze data from Priester and Mantel (Occurrence of tumors in domestic animals. Data from 12 United States and Canadian colleges of veterinary medicine. J Natl Cancer Inst 1971;47:1333-44) about malignancy rates in cows, horses, cats and dogs. From our analysis we found that equines and bovines, animals with less invasive placentation, have lower rates of metastatic cancer than felines and canines in skin and glandular epithelial cancers as well as connective tissue sarcomas. We conclude that a link between type of placentation and species-specific malignancy rates is more likely related to derived mechanisms that suppress invasion rather than different degrees of fetal placental aggressiveness. PMID:25324490

  4. Committee Opinion No. 663 Summary: Aromatase Inhibitors in Gynecologic Practice.

    PubMed

    2016-06-01

    Aromatase inhibitors have been used for the treatment of breast cancer, ovulation induction, endometriosis, and other estrogen-modulated conditions. For women with breast cancer, bone mineral density screening is recommended with long-term aromatase inhibitor use because of risk of osteoporosis due to estrogen deficiency. Based on long-term adverse effects and complication safety data, when compared with tamoxifen, aromatase inhibitors are associated with a reduced incidence of thrombosis, endometrial cancer, and vaginal bleeding. For women with polycystic ovary syndrome and a body mass index greater than 30, letrozole should be considered as first-line therapy for ovulation induction because of the increased live birth rate compared with clomiphene citrate. Lifestyle changes that result in weight loss should be strongly encouraged. Aromatase inhibitors are a promising therapeutic option that may be helpful for the management of endometriosis-associated pain in combination therapy with progestins. PMID:27214185

  5. Committee Opinion No. 663: Aromatase Inhibitors in Gynecologic Practice.

    PubMed

    2016-06-01

    Aromatase inhibitors have been used for the treatment of breast cancer, ovulation induction, endometriosis, and other estrogen-modulated conditions. For women with breast cancer, bone mineral density screening is recommended with long-term aromatase inhibitor use because of risk of osteoporosis due to estrogen deficiency. Based on long-term adverse effects and complication safety data, when compared with tamoxifen, aromatase inhibitors are associated with a reduced incidence of thrombosis, endometrial cancer, and vaginal bleeding. For women with polycystic ovary syndrome and a body mass index greater than 30, letrozole should be considered as first-line therapy for ovulation induction because of the increased live birth rate compared with clomiphene citrate. Lifestyle changes that result in weight loss should be strongly encouraged. Aromatase inhibitors are a promising therapeutic option that may be helpful for the management of endometriosis-associated pain in combination therapy with progestins. PMID:27214191

  6. Medial amygdalar aromatase neurons regulate aggression in both sexes

    PubMed Central

    Unger, Elizabeth K.; Burke, Kenneth J.; Yang, Cindy F.; Bender, Kevin J.; Fuller, Patrick M.; Shah, Nirao M.

    2014-01-01

    SUMMARY Aromatase-expressing neuroendocrine neurons in the vertebrate male brain synthesize estradiol from circulating testosterone. This locally produced estradiol controls neural circuits underlying courtship vocalization, mating, aggression, and territory marking in male mice. How aromatase-expressing neuronal populations control these diverse estrogen-dependent male behaviors is poorly understood, and the function, if any, of aromatase-expressing neurons in females is unclear. Using targeted genetic approaches, we show that aromatase-expressing neurons within the male posterodorsal medial amygdala (MeApd) regulate components of aggression but not other estrogen-dependent male-typical behaviors. Remarkably, aromatase-expressing MeApd neurons in females are specifically required for components of maternal aggression, which we show is distinct from intermale aggression in pattern and execution. Thus, aromatase-expressing MeApd neurons control distinct forms of aggression in the two sexes. Moreover, our findings indicate that complex social behaviors are separable in a modular manner at the level of genetically identified neuronal populations. PMID:25620703

  7. Medial amygdalar aromatase neurons regulate aggression in both sexes.

    PubMed

    Unger, Elizabeth K; Burke, Kenneth J; Yang, Cindy F; Bender, Kevin J; Fuller, Patrick M; Shah, Nirao M

    2015-02-01

    Aromatase-expressing neuroendocrine neurons in the vertebrate male brain synthesize estradiol from circulating testosterone. This locally produced estradiol controls neural circuits underlying courtship vocalization, mating, aggression, and territory marking in male mice. How aromatase-expressing neuronal populations control these diverse estrogen-dependent male behaviors is poorly understood, and the function, if any, of aromatase-expressing neurons in females is unclear. Using targeted genetic approaches, we show that aromatase-expressing neurons within the male posterodorsal medial amygdala (MeApd) regulate components of aggression, but not other estrogen-dependent male-typical behaviors. Remarkably, aromatase-expressing MeApd neurons in females are specifically required for components of maternal aggression, which we show is distinct from intermale aggression in pattern and execution. Thus, aromatase-expressing MeApd neurons control distinct forms of aggression in the two sexes. Moreover, our findings indicate that complex social behaviors are separable in a modular manner at the level of genetically identified neuronal populations.

  8. Aromatase: Contributions to Physiology and Disease in Women and Men.

    PubMed

    Blakemore, Jennifer; Naftolin, Fredrick

    2016-07-01

    Aromatase (estrogen synthetase; EC 1.14.14.1) catalyzes the demethylation of androgens' carbon 19, producing phenolic 18-carbon estrogens. Aromatase is most widely known for its roles in reproduction and reproductive system diseases, and as a target for inhibitor therapy in estrogen-sensitive diseases including cancer, endometriosis, and leiomyoma (141, 143). However, all tissues contain estrogen receptor-expressing cells, the majority of genes have a complete or partial estrogen response element that regulates their expression (61), and there are plentiful nonreceptor effects of estrogens (79); therefore, the effect of aromatase through the provision of estrogen is almost universal in terms of health and disease. This review will provide a brief but comprehensive overview of the enzyme, its role in steroidogenesis, the problems that arise with its functional mutations and mishaps, the roles in human physiology of aromatase and its product estrogens, its current clinical roles, and the effects of aromatase inhibitors. While much of the story is that of the consequences of the formation of its product estrogens, we also will address alternative enzymatic roles of aromatase as a demethylase or nonenzymatic actions of this versatile molecule. Although this short review is meant to be thorough, it is by no means exhaustive; rather, it is meant to reflect the cutting-edge, exciting properties and possibilities of this ancient enzyme and its products. PMID:27252161

  9. The effects of the standardized extracts of Ginkgo biloba on steroidogenesis pathways and aromatase activity in H295R human adrenocortical carcinoma cells

    PubMed Central

    2016-01-01

    Objectives Aromatase inhibitors that block estrogen synthesis are a proven first-line hormonal therapy for postmenopausal breast cancer. Although it is known that standardized extract of Ginkgo biloba (EGb761) induces anti-carcinogenic effects like the aromatase inhibitors, the effects of EGb761 on steroidogenesis have not been studied yet. Therefore, the effects of EGb761 on steroidogenesis and aromatase activity was studied using a H295R cell model, which was a good in vitro model to predict effects on human adrenal steroidogenesis. Methods Cortisol, aldosterone, testosterone, and 17β-estradiol were evaluated in the H295R cells by competitive enzyme-linked immunospecific assay after exposure to EGb761. Real-time polymerase chain reaction were performed to evaluate effects on critical genes in steroid hormone production, specifically cytochrome P450 (CYP11/ 17/19/21) and the hydroxysteroid dehydrogenases (3β-HSD2 and 17β-HSD1/4). Finally, aromatase activities were measured with a tritiated water-release assay and by western blotting analysis. Results H295R cells exposed to EGb761 (10 and 100 μg/mL) showed a significant decrease in 17β-estradiol and testosterone, but no change in aldosterone or cortisol. Genes (CYP19 and 17β-HSD1) related to the estrogen steroidogenesis were significantly decreased by EGb761. EGb761 treatment of H295R cells resulted in a significant decrease of aromatase activity as measured by the direct and indirect assays. The coding sequence/ Exon PII of CYP19 gene transcript and protein level of CYP19 were significantly decreased by EGb761. Conclusions These results suggest that EGb761 could regulate steroidogenesis-related genes such as CYP19 and 17β-HSD1, and lead to a decrease in 17β-estradiol and testosterone. The present study provides good information on potential therapeutic effects of EGb761 on estrogen dependent breast cancer. PMID:27188280

  10. Synthesis and PET studies of [11C-cyano]letrozole (Femara®), an aromatase inhibitor drug

    PubMed Central

    Kil, Kun-Eek; Biegon, Anat; Ding, Yu-Shin; Fischer, Andre; Ferrieri, Richard A.; Kim, Sung Won; Pareto, Deborah; Schueller, Michael J.; Fowler, Joanna S.

    2011-01-01

    Introduction Aromatase, a member of the cytochrome P450 family, converts androgens such as androstenedione and testosterone to estrone and estradiol respectively. Letrozole (1-[bis-(4-cyanophenyl)methyl]-1H-1,2,4-triazole, Femara®) is a high affinity aromatase inhibitor (Ki=11.5 nM) which has FDA approval for breast cancer treatment. Here we report the synthesis of carbon-11 labeled letrozole and its assessment as a radiotracer for brain aromatase in the baboon. Methods Letrozole and its precursor (4-[(4-bromophenyl)-1H-1,2,4-triazol-1-ylmethyl]benzonitrile, 3) were prepared in two-step syntheses from 4-cyanobenzyl bromide and 4-bromobenzyl bromide, respectively. The [11C]cyano group was introduced via the tetrakis(triphenylphosphine)palladium(0) catalyzed coupling of [11C]cyanide with the bromo-precursor (3). PET studies in the baboon brain were carried out to assess regional distribution and kinetics, reproducibility of repeated measures and saturability. The free fraction of letrozole in the plasma, log D, and the [11C-cyano]letrozole fraction in the arterial plasma were also measured. Results [11C-cyano]Letrozole was synthesized in 60 min with a radiochemical yield of 79–80%, with a radiochemical purity greater than 98% and a specific activity of 4.16±2.21 Ci/μmol at the end of bombardment (n=4). PET studies in the baboon revealed initial rapid and high uptake and initial rapid clearance followed by slow clearance of carbon-11 from the brain with no difference between brain regions. The brain kinetics was not affected by co-injection of unlabeled letrozole (0.1 mg/kg). The free fraction of letrozole in plasma was 48.9% and log D was 1.84. Conclusion [11C-cyano]Letrozole is readily synthesized via a palladium catalyzed coupling reaction with [11C]cyanide. Although it is unsuitable as a PET radiotracer for brain aromatase as revealed by the absence of regional specificity and saturability in brain regions, such as amygdala, which are known to contain

  11. [Morphological variability and placental function].

    PubMed

    Malassiné, A

    2001-01-01

    In mammals, the blastocyst defines with the maternal organism, a structure which allows embryonic development during gestation: the placenta. The structure of this organ varies remarkably across species. In this review the different type of placentation have been described in a comparative manner using terms of classification such as: placental materno-fetal interdigitation, matemofetal blood flow interrelationships, layers of the placental interhemal barrier, trophoblast invasiveness and decidual cell reaction, formation of syncytiotrophoblast. The human hemomonochorial placenta is characterized by a strong decidualization of the uterus and a major invasiveness of the extravillous trophoblast. Furthermore, there is a spectrum of placental endocrine activities across species. In some mammals (e.g., mouse and rat) the placenta eclipses the pituitary in the maintenance of ovarian function. In the human and in the sheep, horse, cat and guinea pig, the placenta acquires the ability to substitute for the ovaries in the maintenance of gestation at various time during pregnancy. The human placenta is characterized by a high rate of steroïdogenesis (progesterone and estrogens) and by the production of a primate specific trophoblastic hormone: human chorionic gonadotropin (hCG). Recently, it was demonstrated that mutation of many genes in mice results in embryonic mortality or fetal growth restriction, due to defects in placental development. Furthermore, distinct molecular pathways regulate the differentiation of various trophoblast cell subtype of the mouse placenta. An important question is whether or not placental differentiation in other mammals is regulated by the same molecular mechanisms. Due to the striking diversity in placental structure, endocrine function and gene expression, caution must be exercised in extrapolating findings regarding placental function and development from one species to another. PMID:11575143

  12. Synthesis and biological characterization of 3-(imidazol-1-ylmethyl)piperidine sulfonamides as aromatase inhibitors.

    PubMed

    Di Matteo, Mauro; Ammazzalorso, Alessandra; Andreoli, Federico; Caffa, Irene; De Filippis, Barbara; Fantacuzzi, Marialuigia; Giampietro, Letizia; Maccallini, Cristina; Nencioni, Alessio; Parenti, Marco Daniele; Soncini, Debora; Del Rio, Alberto; Amoroso, Rosa

    2016-07-01

    The most frequently used treatment for hormone receptor positive breast cancer in post-menopausal women are aromatase inhibitors. In order to develop new aromatase inhibitors, we designed and synthesized new imidazolylmethylpiperidine sulfonamides using the structure of the previously identified aromatase inhibitor SYN 20028567 as starting lead. By this approach, three new aromatase inhibitors with IC50 values that are similar to that of letrozole and SYN 20028567 were identified. PMID:27161804

  13. Aromatase inhibitors in stimulated IVF cycles

    PubMed Central

    2011-01-01

    Aromatase inhibitors have been introduced as a new treatment modality that could challenge clomiphene citrate as an ovulation induction regiment in patients with PCOS. Although several randomized trials have been conducted regarding their use as ovulation induction agents, only few trials are available regarding their efficacy in IVF stimulated cycles. Current available evidence support that letrozole may have a promising role in stimulated IVF cycles, either when administered during the follicular phase for ovarian stimulation. Especially for women with poor ovarian response, letrozole appears to have the potential to increase clinical pregnancy rates when combined with gonadotropins, whereas at the same time reduces the total gonadotropin dose required for ovarian stimulation. However, given that in all of the trials letrozole has been administered in GnRH antagonist cycles, it is intriguing to test in the future how it may perform when used in GnRH agonist cycles. Finally administration of letrozole during luteal phase in IVF cycles offers another treatment modality for patients at high risk for OHSS taking into account that it drastically reduces estradiol levels PMID:21693033

  14. Placental Growth Factor Administration Abolishes Placental Ischemia-Induced Hypertension.

    PubMed

    Spradley, Frank T; Tan, Adelene Y; Joo, Woo S; Daniels, Garrett; Kussie, Paul; Karumanchi, S Ananth; Granger, Joey P

    2016-04-01

    Preeclampsia is a pregnancy-specific disorder of new-onset hypertension. Unfortunately, the most effective treatment is early delivery of the fetus and placenta. Placental ischemia appears central to the pathogenesis of preeclampsia because placental ischemia/hypoxia induced in animals by reduced uterine perfusion pressure (RUPP) or in humans stimulates release of hypertensive placental factors into the maternal circulation. The anti-angiogenic factor soluble fms-like tyrosine kinase-1 (sFlt-1), which antagonizes and reduces bioavailable vascular endothelial growth factor and placental growth factor (PlGF), is elevated in RUPP rats and preeclampsia. Although PlGF and vascular endothelial growth factor are both natural ligands for sFlt-1, vascular endothelial growth factor also has high affinity to VEGFR2 (Flk-1) causing side effects like edema. PlGF is specific for sFlt-1. We tested the hypothesis that PlGF treatment reduces placental ischemia-induced hypertension by antagonizing sFlt-1 without adverse consequences to the mother or fetus. On gestational day 14, rats were randomized to 4 groups: normal pregnant or RUPP±infusion of recombinant human PlGF (180 μg/kg per day; AG31, a purified, recombinant human form of PlGF) for 5 days via intraperitoneal osmotic minipumps. On day 19, mean arterial blood pressure and plasma sFlt-1 were higher and glomerular filtration rate lower in RUPP than normal pregnant rats. Infusion of recombinant human PlGF abolished these changes seen with RUPP along with reducing oxidative stress. These data indicate that the increased sFlt-1 and reduced PlGF resulting from placental ischemia contribute to maternal hypertension. Our novel finding that recombinant human PlGF abolishes placental ischemia-induced hypertension, without major adverse consequences, suggests a strong therapeutic potential for this growth factor in preeclampsia. PMID:26831193

  15. Exploring new chemical functionalities to improve aromatase inhibition of steroids.

    PubMed

    Varela, Carla L; Amaral, Cristina; Correia-da-Silva, Georgina; Costa, Saul C; Carvalho, Rui A; Costa, Giosuè; Alcaro, Stefano; Teixeira, Natércia A A; Tavares-da-Silva, Elisiário J; Roleira, Fernanda M F

    2016-06-15

    In this work, new potent steroidal aromatase inhibitors both in microsomes and in breast cancer cells have been found. The synthesis of the 3,4-(ethylenedioxy)androsta-3,5-dien-17-one (12), a new steroid containing a heterocycle dioxene fused in the A-ring, led to the discovery of a new reaction for which a mechanism is proposed. New structure-activity relationships were established. Some 5β-steroids, such as compound 4β,5β-epoxyandrostan-17-one (9), showed aromatase inhibitory activity, because they adopt a similar A-ring conformation as those of androstenedione, the natural substrate of aromatase. Moreover, new chemical features to increase planarity were disclosed, specifically the 3α,4α-cyclopropane ring, as in 3α,4α-methylen-5α-androstan-17-one (5) (IC50=0.11μM), and the Δ(9-11) double bond in the C-ring, as in androsta-4,9(11)-diene-3,17-dione (13) (IC50=0.25μM). In addition, induced-fit docking (IFD) simulations and site of metabolism (SoM) predictions helped to explain the recognition of new potent steroidal aromatase inhibitors within the enzyme. These insights can be valuable tools for the understanding of the molecular recognition process by the aromatase and for the future design of new steroidal inhibitors. PMID:27160054

  16. Differential Regulation of Aromatase Isoforms and Tissue Responses to Environmental Chemicals in Fish

    EPA Science Inventory

    As in mammals, aromatase plays a basic role in fish reproduction. Unlike most mammals, with only one form of aromatase, fish have two distinct forms. One isoform, P450aromA, predominates in ovaries. Ovarian aromatase activity controls circulating levels of estrogens and is critic...

  17. Human placental calcitonin receptors.

    PubMed Central

    Nicholson, G C; D'Santos, C S; Evans, T; Moseley, J M; Kemp, B E; Michelangeli, V P; Martin, T J

    1988-01-01

    Receptors for the hypocalcaemic hormone, calcitonin (CT), have been identified in a membrane fraction prepared from term human placentae. Binding of 125I-labelled salmon CT (125I-sCT) to the membranes was time- and temperature-dependent, saturable (Bmax. 58 +/- 11 fmol/mg of protein), of high affinity (Kd 80 +/- 21 pM) and poorly reversible. Species-specific CTs and CT analogues competed for 125I-sCT binding with potencies proportional to their known biological potencies. Various unrelated peptide hormones did not compete, indicating that receptor binding was specific for CT. Photoaffinity labelling using a derivatized biologically active sCT analogue, [Arg11,18,3-nitrophenylazide-Lys14]sCT, identified a receptor component of Mr approximately 85,000, comparable with findings in osteoclasts and other target cells. The presence of CT receptors in the human placenta supports other evidence that CT may have a role in the regulation of placental function. PMID:2839149

  18. Developing predictive approaches to characterize adaptive responses of the reproductive endocrine axis to aromatase inhibition: II. Computational modeling.

    PubMed

    Breen, Miyuki; Villeneuve, Daniel L; Ankley, Gerald T; Bencic, David C; Breen, Michael S; Watanabe, Karen H; Lloyd, Alun L; Conolly, Rory B

    2013-06-01

    Endocrine-disrupting chemicals can affect reproduction and development in humans and wildlife. We developed a computational model of the hypothalamic-pituitary-gonadal (HPG) axis in female fathead minnows to predict dose-response and time-course (DRTC) behaviors for endocrine effects of the aromatase inhibitor, fadrozole (FAD). The model describes adaptive responses to endocrine stress involving regulated secretion of a generic gonadotropin (LH/FSH) from the hypothalamic-pituitary complex. For model development, we used plasma 17β-estradiol (E2) concentrations and ovarian cytochrome P450 (CYP) 19A aromatase mRNA data from two time-course experiments, each of which included both an exposure and a depuration phase, and plasma E2 data from a third 4-day study. Model parameters were estimated using E2 concentrations for 0, 0.5, and 3 µg/l FAD exposure concentrations, and good fits to these data were obtained. The model accurately predicted CYP19A mRNA fold changes for controls and three FAD doses (0, 0.5, and 3 µg/l) and plasma E2 dose response from the 4-day study. Comparing the model-predicted DRTC with experimental data provided insight into how the feedback control mechanisms in the HPG axis mediate these changes: specifically, adaptive changes in plasma E2 levels occurring during exposure and "overshoot" occurring postexposure. This study demonstrates the value of mechanistic modeling to examine and predict dynamic behaviors in perturbed systems. As this work progresses, we will obtain a refined understanding of how adaptive responses within the vertebrate HPG axis affect DRTC behaviors for aromatase inhibitors and other types of endocrine-active chemicals and apply that knowledge in support of risk assessments.

  19. Bisphenol A differentially activates protein kinase C isoforms in murine placental tissue.

    PubMed

    Tan, Wenjuan; Huang, Hui; Wang, Yanfei; Wong, Tsz Yan; Wang, C C; Leung, Lai K

    2013-06-01

    Bisphenol A is utilized to make polycarbonate plastics and is an environmental pollutant. Recent research has indicated that it is an endocrine disruptor and may interfere with reproductive processes. Our lab has previously shown that bisphenol A could regulate corticotrophin releasing hormone and aromatase in cultured placental cells. In the present study, the effect of bisphenol A on these two genes in the placenta was investigated in mice. Pregnant ICR mice were gavaged with bisphenol A at 2, 20 and 200mg/kg body weight/day from E13 to E16 and were euthanized at E17. Compared to the control mice, increased plasma estrogen and corticotrophin releasing hormone were observed in bisphenol A-treated mice. Messenger RNA quantification indicated that placental crh but not cyp19 was induced in mice treated with bisphenol A. Tracking the related signaling pathway, we found that protein kinase C ζ/λ and δ were activated in the placentas of bisphenol A-treated mice. As the gene promoter of crh contains CRE and the half site of ERE, either phospho-PKC or estrogen could stimulate the gene transactivation. These results indicate that bisphenol A might increase plasma concentrations of estradiol, testosterone, corticotrophin releasing hormone and placental phospho-PKC ζ/λ and δ in mice. Ultimately, the incidence of premature birth in these mice could increase.

  20. Programming placental nutrient transport capacity

    PubMed Central

    Fowden, A L; Ward, J W; Wooding, F P B; Forhead, A J; Constancia, M

    2006-01-01

    Many animal studies and human epidemiological findings have shown that impaired growth in utero is associated with physiological abnormalities in later life and have linked this to tissue programming during suboptimal intrauterine conditions at critical periods of development. However, few of these studies have considered the contribution of the placenta to the ensuing adult phenotype. In mammals, the major determinant of intrauterine growth is the placental nutrient supply, which, in turn, depends on the size, morphology, blood supply and transporter abundance of the placenta and on synthesis and metabolism of nutrients and hormones by the uteroplacental tissues. This review examines the regulation of placental nutrient transfer capacity and the potential programming effects of nutrition and glucocorticoid over-exposure on placental phenotype with particular emphasis on the role of the Igf2 gene in these processes. PMID:16439433

  1. Potential utility of natural products as regulators of breast cancer-associated aromatase promoters

    PubMed Central

    2011-01-01

    Aromatase, the key enzyme in estrogen biosynthesis, converts androstenedione to estrone and testosterone to estradiol. The enzyme is expressed in various tissues such as ovary, placenta, bone, brain, skin, and adipose tissue. Aromatase enzyme is encoded by a single gene CYP 19A1 and its expression is controlled by tissue-specific promoters. Aromatase mRNA is primarily transcribed from promoter I.4 in normal breast tissue and physiological levels of aromatase are found in breast adipose stromal fibroblasts. Under the conditions of breast cancer, as a result of the activation of a distinct set of aromatase promoters (I.3, II, and I.7) aromatase expression is enhanced leading to local overproduction of estrogen that promotes breast cancer. Aromatase is considered as a potential target for endocrine treatment of breast cancer but due to nonspecific reduction of aromatase activity in other tissues, aromatase inhibitors (AIs) are associated with undesirable side effects such as bone loss, and abnormal lipid metabolism. Inhibition of aromatase expression by inactivating breast tumor-specific aromatase promoters can selectively block estrogen production at the tumor site. Although several synthetic chemical compounds and nuclear receptor ligands are known to inhibit the activity of the tumor-specific aromatase promoters, further development of more specific and efficacious drugs without adverse effects is still warranted. Plants are rich in chemopreventive agents that have a great potential to be used in chemotherapy for hormone dependent breast cancer which could serve as a source for natural AIs. In this brief review, we summarize the studies on phytochemicals such as biochanin A, genistein, quercetin, isoliquiritigenin, resveratrol, and grape seed extracts related to their effect on the activation of breast cancer-associated aromatase promoters and discuss their aromatase inhibitory potential to be used as safer chemotherapeutic agents for specific hormone

  2. Caught in a Network: Recovery from Aromatase Inhibition

    EPA Science Inventory

    Fadrozole is an inhibitor of aromatase, an enzyme critical to estrogen synthesis. We exposed female fathead minnows (Pimephales promelas, FHM) to 0 or 30 ug/L fadrozole for 8 days, and fish were then held in clean water for 8 extra days. We analyzed ex vivo steroid production, pl...

  3. AOP description: Aromatase inhibition leading to reproductive dysfunction (in fish)

    EPA Science Inventory

    This adverse outcome pathway details the linkage between inhibition of gonadal aromatase activity in females and the adverse effect of reduced cumulative fecundity in repeat-spawning fish species. Cumulative fecundity is the most apical endpoint considered in the OECD 229 Fish Sh...

  4. Aromatase Is Required for Female Abdominal Aortic Aneurysm Protection

    PubMed Central

    Johnston, William F.; Salmon, Morgan; Su, Gang; Lu, Guanyi; Ailawadi, Gorav; Upchurch, Gilbert R.

    2014-01-01

    Objective The protective effects of female gender on the development of abdominal aortic aneurysms (AAAs) have been attributed to anti-inflammatory effects of estrogen. All estrogen synthesis is dependent upon the enzyme aromatase, which is located both centrally in the ovaries and peripherally in adipose tissue, bone, and vascular smooth muscle cells. It is hypothesized that deletion of aromatase in both ovaries and peripheral tissues would diminish the protective effect of female gender and would be associated with increased aortic diameter in female mice. Methods Male and female 8–10 week-old mice with aromatase (wild type: WT) and without aromatase (ArKO) underwent elastase aortic perfusion with aortic harvest 14 days following. To evaluate the contribution of central and peripheral estrogen conversion, female WT mice were compared to female WT and ArKO mice that had undergone ovariectomy (ovx) at 6 weeks followed by elastase perfusion at 8–10 weeks. At aortic harvest, maximal aortic dilation was measured and samples were collected for immunohistochemistry and protein analysis. Serum was collected for serum estradiol concentrations. Groups were compared with analysis of variance (ANOVA). Human and mouse AAA cross-sections were analyzed with confocal immunohistochemistry for aromatase, smooth muscle markers, and macrophage markers. Results Female WT mice had significant reduction in aortic dilation compared to male WT mice (F WT: 51.5±15.1% vs. M WT: 78.7±14.9%, p<0.005). The protective effects of female gender were completely eliminated with deletion of aromatase (F ArKO: 82.6±13.8%, p<0.05 vs. F WT). Ovariectomy increased aortic dilation in WT mice (F WT ovx: 70.6±11.7%, p<0.05 vs. F WT). Aromatase deletion with ovariectomy further increased aortic dilation compared to WT ovx mice (F ArKO ovx: 87.3±14.7%, p<0.001 vs. F WT and p<0.05 vs. F WT ovx). Accordingly, female ArKO ovx mice had significantly higher levels of proinflammatory cytokines MCP-1 and

  5. Aromatase, estrogen receptors and brain development in fish and amphibians.

    PubMed

    Coumailleau, Pascal; Pellegrini, Elisabeth; Adrio, Fátima; Diotel, Nicolas; Cano-Nicolau, Joel; Nasri, Ahmed; Vaillant, Colette; Kah, Olivier

    2015-02-01

    Estrogens affect brain development of vertebrates, not only by impacting activity and morphology of existing circuits, but also by modulating embryonic and adult neurogenesis. The issue is complex as estrogens can not only originate from peripheral tissues, but also be locally produced within the brain itself due to local aromatization of androgens. In this respect, teleost fishes are quite unique because aromatase is expressed exclusively in radial glial cells, which represent pluripotent cells in the brain of all vertebrates. Expression of aromatase in the brain of fish is also strongly stimulated by estrogens and some androgens. This creates a very intriguing positive auto-regulatory loop leading to dramatic aromatase expression in sexually mature fish with elevated levels of circulating steroids. Looking at the effects of estrogens or anti-estrogens in the brain of adult zebrafish showed that estrogens inhibit rather than stimulate cell proliferation and newborn cell migration. The functional meaning of these observations is still unclear, but these data suggest that the brain of fish is experiencing constant remodeling under the influence of circulating steroids and brain-derived neurosteroids, possibly permitting a diversification of sexual strategies, notably hermaphroditism. Recent data in frogs indicate that aromatase expression is limited to neurons and do not concern radial glial cells. Thus, until now, there is no other example of vertebrates in which radial progenitors express aromatase. This raises the question of when and why these new features were gained and what are their adaptive benefits. This article is part of a Special Issue entitled: Nuclear receptors in animal development.

  6. Aromatase, estrogen receptors and brain development in fish and amphibians.

    PubMed

    Coumailleau, Pascal; Pellegrini, Elisabeth; Adrio, Fátima; Diotel, Nicolas; Cano-Nicolau, Joel; Nasri, Ahmed; Vaillant, Colette; Kah, Olivier

    2015-02-01

    Estrogens affect brain development of vertebrates, not only by impacting activity and morphology of existing circuits, but also by modulating embryonic and adult neurogenesis. The issue is complex as estrogens can not only originate from peripheral tissues, but also be locally produced within the brain itself due to local aromatization of androgens. In this respect, teleost fishes are quite unique because aromatase is expressed exclusively in radial glial cells, which represent pluripotent cells in the brain of all vertebrates. Expression of aromatase in the brain of fish is also strongly stimulated by estrogens and some androgens. This creates a very intriguing positive auto-regulatory loop leading to dramatic aromatase expression in sexually mature fish with elevated levels of circulating steroids. Looking at the effects of estrogens or anti-estrogens in the brain of adult zebrafish showed that estrogens inhibit rather than stimulate cell proliferation and newborn cell migration. The functional meaning of these observations is still unclear, but these data suggest that the brain of fish is experiencing constant remodeling under the influence of circulating steroids and brain-derived neurosteroids, possibly permitting a diversification of sexual strategies, notably hermaphroditism. Recent data in frogs indicate that aromatase expression is limited to neurons and do not concern radial glial cells. Thus, until now, there is no other example of vertebrates in which radial progenitors express aromatase. This raises the question of when and why these new features were gained and what are their adaptive benefits. This article is part of a Special Issue entitled: Nuclear receptors in animal development. PMID:25038582

  7. Placental Adaptations in Growth Restriction

    PubMed Central

    Zhang, Song; Regnault, Timothy R.H.; Barker, Paige L.; Botting, Kimberley J.; McMillen, Isabella C.; McMillan, Christine M.; Roberts, Claire T.; Morrison, Janna L.

    2015-01-01

    The placenta is the primary interface between the fetus and mother and plays an important role in maintaining fetal development and growth by facilitating the transfer of substrates and participating in modulating the maternal immune response to prevent immunological rejection of the conceptus. The major substrates required for fetal growth include oxygen, glucose, amino acids and fatty acids, and their transport processes depend on morphological characteristics of the placenta, such as placental size, morphology, blood flow and vascularity. Other factors including insulin-like growth factors, apoptosis, autophagy and glucocorticoid exposure also affect placental growth and substrate transport capacity. Intrauterine growth restriction (IUGR) is often a consequence of insufficiency, and is associated with a high incidence of perinatal morbidity and mortality, as well as increased risk of cardiovascular and metabolic diseases in later life. Several different experimental methods have been used to induce placental insufficiency and IUGR in animal models and a range of factors that regulate placental growth and substrate transport capacity have been demonstrated. While no model system completely recapitulates human IUGR, these animal models allow us to carefully dissect cellular and molecular mechanisms to improve our understanding and facilitate development of therapeutic interventions. PMID:25580812

  8. Ovarian and placental morphology and endocrine functions in the pregnant giraffe (Giraffa camelopardalis).

    PubMed

    Wilsher, S; Stansfield, F; Greenwood, R E S; Trethowan, P D; Anderson, R A; Wooding, F B W; Allen, W R

    2013-06-01

    Gross, histological and immunocytochemical examinations carried out on maternal and fetal reproductive tissues from two pregnant giraffes at an estimated 8 and 13.5 months of gestation (term=15 months) revealed a typically ruminant macrocotyledonary placenta with binucleate trophoblast cells scattered sparsely in the placentome where they stained intensely with a prolactin antiserum. Binucleate cells were present in greater numbers in the intercotyledonary allantochorion where they did not stain for prolactin whereas the uninucleate trophoblast still did. A single large corpus luteum of pregnancy and several small luteinised follicles were present in the maternal ovaries while the fetal ovaries at 13.5 months gestation showed an assortment of enlarging antral follicles and partially and completely lutenised follicles, the granulosa and luteal cells of which stained positively for 3β-hydroxysteroid dehydrogenase (3β-HSD), 17,20 lyase, prolactin, progesterone receptor and androgen receptor, but negatively for aromatase. The uninucleate trophoblast of the placentome and intercotyledonary allantochorion, the epithelium of the maternal endometrial glands, the seminiferous epithelium in the fetal testis at 8 months of gestation and the zonae fasciculata and reticularis of the fetal adrenal at 13.5 months also stained positively for 3β-HSD and negatively for aromatase. Endocrinologically, it appears that the giraffe placenta is more similar to that of the sheep than the cow with a placental lactogen as the likely driver of the considerable degree of luteinisation seen in both the maternal and the fetal ovaries. PMID:23550169

  9. RELATIONSHIP BETWEEN BRAIN AND OVARY AROMATASE ACTIVITY AND ISOFORM-SPECIFIC AROMATASE MRNA EXPRESSION IN THE FATHEAD MINNOW (PIMEPHALES PROMELAS) - JOURNAL ARTICLE

    EPA Science Inventory

    There is growing evidence that some chemicals present in the environment have the capacity to inhibit, or potentially induce, aromatase activity. This study compared aromatase activities and isoform-specific mRNA expression in brain and ovary tissue from non-exposed fathead minn...

  10. Immunohistochemical analysis of aromatase in metastatic lymph nodes of breast cancer.

    PubMed

    Shibahara, Yukiko; Miki, Yasuhiro; Ishida, Takanori; Nakamura, Yasuhiro; Suzuki, Takashi; Ohuchi, Noriaki; Sasano, Hironobu

    2013-01-01

    Aromatase is the key enzyme in intratumoral estrogen production in postmenopausal breast cancer and third generation aromatase inhibitors suppress this enzymatic reaction effectively. Aromatase inhibitor is administered to metastatic breast cancer patients customarily in which estrogen receptor had been demonstrated only in the primary tumor, not the metastatic sites. The status of aromatase in metastatic sites has not been well-characterized to date. We immunolocalized aromatase in 46 estrogen receptor positive primary breast cancers and paired metastatic lymph nodes, using immunohistochemistry. Immunoreactivity was detected in 44/46 primary tumors and 40/46 metastatic lymph nodes. A significant correlation was detected between the status of aromatase in primary and metastatic sites. Aromatase immunoreactivity was correlated with age, size of primary tumor and Ki-67 index. Aromatase immunoreactivity was also detected in adipose tissue surrounding the lymph nodes. In conclusion, aromatase status in primary tumors generally represents its status in metastatic lymph nodes. This indicates that the endocrine environment of estrogen receptor positive tumors remain stable during the metastatic process. PMID:23356222

  11. Placental Origins of Chronic Disease.

    PubMed

    Burton, Graham J; Fowden, Abigail L; Thornburg, Kent L

    2016-10-01

    Epidemiological evidence links an individual's susceptibility to chronic disease in adult life to events during their intrauterine phase of development. Biologically this should not be unexpected, for organ systems are at their most plastic when progenitor cells are proliferating and differentiating. Influences operating at this time can permanently affect their structure and functional capacity, and the activity of enzyme systems and endocrine axes. It is now appreciated that such effects lay the foundations for a diverse array of diseases that become manifest many years later, often in response to secondary environmental stressors. Fetal development is underpinned by the placenta, the organ that forms the interface between the fetus and its mother. All nutrients and oxygen reaching the fetus must pass through this organ. The placenta also has major endocrine functions, orchestrating maternal adaptations to pregnancy and mobilizing resources for fetal use. In addition, it acts as a selective barrier, creating a protective milieu by minimizing exposure of the fetus to maternal hormones, such as glucocorticoids, xenobiotics, pathogens, and parasites. The placenta shows a remarkable capacity to adapt to adverse environmental cues and lessen their impact on the fetus. However, if placental function is impaired, or its capacity to adapt is exceeded, then fetal development may be compromised. Here, we explore the complex relationships between the placental phenotype and developmental programming of chronic disease in the offspring. Ensuring optimal placentation offers a new approach to the prevention of disorders such as cardiovascular disease, diabetes, and obesity, which are reaching epidemic proportions. PMID:27604528

  12. Placental oxygen transport estimated by the hyperoxic placental BOLD MRI response.

    PubMed

    Sørensen, Anne; Sinding, Marianne; Peters, David A; Petersen, Astrid; Frøkjær, Jens B; Christiansen, Ole B; Uldbjerg, Niels

    2015-10-01

    Estimating placental oxygen transport capacity is highly desirable, as impaired placental function is associated with fetal growth restriction (FGR) and poor neonatal outcome. In clinical obstetrics, a noninvasive method to estimate the placental oxygen transport is not available, and the current methods focus on fetal well-being rather than on direct assessment of placental function. In this article, we aim to estimate the placental oxygen transport using the hyperoxic placental blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) response. In 21 normal pregnancies and in four cases of severe early onset FGR, placental BOLD MRI was performed in a 1.5 Tesla MRI system (TR:8000 msec, TE:50 msec, Flip angle:90). Placental histological examination was performed in the FGR cases. In normal pregnancies, the average hyperoxic placental BOLD response was 12.6 ± 5.4% (mean ± SD). In the FGR cases, the hyperoxic BOLD response was abnormal only in cases with histological signs of maternal hypoperfusion of the placenta. The hyperoxic placental BOLD response is mainly derived from an increase in the saturation of maternal venous blood. In the normal placenta, the pO2 of the umbilical vein is closely related to the pO2 of the uterine vein. Therefore, the hyperoxic placental BOLD response may reflect the placental oxygen supply to the fetus. In early onset FGR, the placental oxygen transport is reduced mainly because of the maternal hypoperfusion, and in these cases the placental BOLD response might be altered. Thus, the placental BOLD MRI might provide direct noninvasive assessment of placental oxygen transport. PMID:26471757

  13. Placental oxygen transport estimated by the hyperoxic placental BOLD MRI response.

    PubMed

    Sørensen, Anne; Sinding, Marianne; Peters, David A; Petersen, Astrid; Frøkjær, Jens B; Christiansen, Ole B; Uldbjerg, Niels

    2015-10-01

    Estimating placental oxygen transport capacity is highly desirable, as impaired placental function is associated with fetal growth restriction (FGR) and poor neonatal outcome. In clinical obstetrics, a noninvasive method to estimate the placental oxygen transport is not available, and the current methods focus on fetal well-being rather than on direct assessment of placental function. In this article, we aim to estimate the placental oxygen transport using the hyperoxic placental blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) response. In 21 normal pregnancies and in four cases of severe early onset FGR, placental BOLD MRI was performed in a 1.5 Tesla MRI system (TR:8000 msec, TE:50 msec, Flip angle:90). Placental histological examination was performed in the FGR cases. In normal pregnancies, the average hyperoxic placental BOLD response was 12.6 ± 5.4% (mean ± SD). In the FGR cases, the hyperoxic BOLD response was abnormal only in cases with histological signs of maternal hypoperfusion of the placenta. The hyperoxic placental BOLD response is mainly derived from an increase in the saturation of maternal venous blood. In the normal placenta, the pO2 of the umbilical vein is closely related to the pO2 of the uterine vein. Therefore, the hyperoxic placental BOLD response may reflect the placental oxygen supply to the fetus. In early onset FGR, the placental oxygen transport is reduced mainly because of the maternal hypoperfusion, and in these cases the placental BOLD response might be altered. Thus, the placental BOLD MRI might provide direct noninvasive assessment of placental oxygen transport.

  14. Placental oxygen transport estimated by the hyperoxic placental BOLD MRI response

    PubMed Central

    Sørensen, Anne; Sinding, Marianne; Peters, David A; Petersen, Astrid; Frøkjær, Jens B; Christiansen, Ole B; Uldbjerg, Niels

    2015-01-01

    Estimating placental oxygen transport capacity is highly desirable, as impaired placental function is associated with fetal growth restriction (FGR) and poor neonatal outcome. In clinical obstetrics, a noninvasive method to estimate the placental oxygen transport is not available, and the current methods focus on fetal well-being rather than on direct assessment of placental function. In this article, we aim to estimate the placental oxygen transport using the hyperoxic placental blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) response. In 21 normal pregnancies and in four cases of severe early onset FGR, placental BOLD MRI was performed in a 1.5 Tesla MRI system (TR:8000 msec, TE:50 msec, Flip angle:90). Placental histological examination was performed in the FGR cases. In normal pregnancies, the average hyperoxic placental BOLD response was 12.6 ± 5.4% (mean ± SD). In the FGR cases, the hyperoxic BOLD response was abnormal only in cases with histological signs of maternal hypoperfusion of the placenta. The hyperoxic placental BOLD response is mainly derived from an increase in the saturation of maternal venous blood. In the normal placenta, the pO2 of the umbilical vein is closely related to the pO2 of the uterine vein. Therefore, the hyperoxic placental BOLD response may reflect the placental oxygen supply to the fetus. In early onset FGR, the placental oxygen transport is reduced mainly because of the maternal hypoperfusion, and in these cases the placental BOLD response might be altered. Thus, the placental BOLD MRI might provide direct noninvasive assessment of placental oxygen transport. PMID:26471757

  15. Effect of dioxin exposure on aromatase expression in ovariectomized rats

    SciTech Connect

    Ye Lan; Leung, Lai K.

    2008-05-15

    Because of their persistence in the environment dioxins are one of the most concerned classes of carcinogens. Displaying both pro- and anti-agonistic properties to some hormone receptors, the pollutants are also known to be endocrine disruptors. Humans can be exposed to this pollutant through contaminated food, air, drinking water, etc. The female hormone estrogen may initiate various physiological functions, and excessive exposure to this hormone is a documented risk factor for carcinogenesis. Cyp19 (aromatase) catalyses the last step of estrogen biosynthesis, while cyp1a1 can hydroxylate and deactivate the hormone. In the present study, we investigated the effect of 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD) on aromatase expression in the brain and adipose tissue in ovariectomized Sprague Dawley rats. Female rats were given 2.5 {mu}g/kg TCDD p.o. before and after ovariectomy. Real-time PCR and western blot analysis indicated that pre-ovariectomy administration of TCDD could significantly reduce aromatase expression in the brain but increase the expression in the adipose tissue. In addition, increased plasma estrogen level and uterine weight were observed in these rats. These parameters did not change in rats with post-ovariectomy TCDD treatment. Our results suggested that the timing of exposure to the toxicant could determine the estrogenicity of TCDD. No correlation between cyp1a1 and cyp19 expression was observed.

  16. Placental Findings in Singleton Stillbirths

    PubMed Central

    Pinar, Halit; Goldenberg, Robert L.; Koch, Matthew A.; Heim-Hall, Josefine; Hawkins, Hal K.; Shehata, Bahig; Abramowsky, Carlos; Parker, Corette B.; Dudley, Donald J.; Silver, Robert M.; Stoll, Barbara; Carpenter, Marshall; Saade, George; Moore, Janet; Conway, Deborah; Varner, Michael W.; Hogue, Carol J.R.; Coustan, Donald R.; Sbrana, Elena; Thorsten, Vanessa; Willinger, Marian; Reddy, Uma M.

    2014-01-01

    Objective To compare placental lesions for stillbirth cases and live birth controls in a population-based study. Methods Pathological examinations were performed on placentas from singleton pregnancies using a standard protocol. Data were analyzed overall and within gestational age groups at delivery. Results Placentas from 518 stillbirths and 1,200 live births were studied. Single umbilical artery was present in 7.7% of stillbirths and 1.7% of live births, velamentous cord insertion was present in 5% of stillbirths and 1.1% of live births, diffuse terminal villous immaturity was present in 10.3% of stillbirths and 2.3% of live births, inflammation (eg, acute chorioamnionitis of placental membranes) was present in 30.4% of stillbirths and 12% of live births, vascular degenerative changes in chorionic plate was present in 55.7% of stillbirths and 0.5% of live births, retroplacental hematoma was present in 23.8% of stillbirths and 4.2% of live births, intraparenchymal thrombi was present in 19.7% of stillbirths and 13.3% of live births, parenchymal infarction was present in 10.9% of stillbirths and 4.4% of live births, fibrin deposition was present in 9.2% of stillbirths and 1.5% of live births, fetal vascular thrombi was present in 23% of stillbirths and 7% of live births, avascular villi was present in 7.6% of stillbirths and 2.0% of live births, and hydrops was present in 6.4% of stillbirths and 1.0% of live births. Among stillbirths, inflammation and retroplacental hematoma were more common in placentas from early deliveries, while thrombotic lesions were more common in later gestation. Inflammatory lesions were especially common in early live births. Conclusion Placental lesions were highly associated with stillbirth compared to live births. All lesions associated with stillbirth were found in live births but often with variations by gestational age at delivery. Knowledge of lesion prevalence within gestational age groups in both stillbirths and live birth

  17. Dynamics and Flexibility of Human Aromatase Probed by FTIR and Time Resolved Fluorescence Spectroscopy

    PubMed Central

    Sadeghi, Sheila J.; Castrignanò, Silvia; Mei, Giampiero; Di Venere, Almerinda; Nicolai, Eleonora; Allegra, Paola; Gilardi, Gianfranco

    2013-01-01

    Human aromatase (CYP19A1) is a steroidogenic cytochrome P450 converting androgens into estrogens. No ligand-free crystal structure of the enzyme is available to date. The crystal structure in complex with the substrate androstenedione and the steroidal inhibitor exemestane shows a very compact conformation of the enzyme, leaving unanswered questions on the conformational changes that must occur to allow access of the ligand to the active site. As H/D exchange kinetics followed by FTIR spectroscopy can provide information on the conformational changes in proteins where solvent accessibility is affected, here the amide I region was used to measure the exchange rates of the different elements of the secondary structure for aromatase in the ligand-free form and in the presence of the substrate androstenedione and the inhibitor anastrozole. Biphasic exponential functions were found to fit the H/D exchange data collected as a function of time. Two exchange rates were assigned to two populations of protons present in different flexible regions of the protein. The addition of the substrate androstenedione and the inhibitor anastrozole lowers the H/D exchange rates of the α-helices of the enzyme when compared to the ligand-free form. Furthermore, the presence of the inhibitor anastrozole lowers exchange rate constant (k1) for β-sheets from 0.22±0.06 min−1 for the inhibitor-bound enzyme to 0.12±0.02 min−1 for the free protein. Dynamics effects localised in helix F were studied by time resolved fluorescence. The data demonstrate that the fluorescence lifetime component associated to Trp224 emission undergoes a shift toward longer lifetimes (from ≈5.0 to ≈5.5 ns) when the substrate or the inhibitor are present, suggesting slower dynamics in the presence of ligands. Together the results are consistent with different degrees of flexibility of the access channel and therefore different conformations adopted by the enzyme in the free, substrate- and inhibitor

  18. Computational Modeling to Evaluate Alternative Hypotheses for the Linkage of Aromatase Inhibition to Vitellogenin Levels in Fathead Minnows

    EPA Science Inventory

    Aromatase converts testosterone to estradiol (E2). In fish, E2 concentrations control hepatic synthesis of the glycolipoprotein vitellogenin (VTG), an egg yolk precursor protein essential to oocyte development and larval survival. Fathead minnows were exposed to the aromatase in...

  19. Modulation of Aromatase Activity as a Mode of Action for Endocrine Disrupting Chemicals in a Marine Fish

    EPA Science Inventory

    The steroidogenic enzyme aromatase catalyzes the conversion of androgens (androstenedione and testosterone) to estrogens (estrone and estradiol) and therefore plays a central role in reproduction. In contrast to most vertebrates, teleost fish have two distinct forms of aromatase....

  20. Inhibition of human placental progesterone and estrogen synthesis in early human gestation by aminoglutethimide in vivo.

    PubMed

    Rabe, T; Mösch, R; Franke, C; Nobakht, N; Runnebaum, B

    1983-03-01

    The inhibitory effect of d,l-aminoglutethimide (AG) on the synthesis of progesterone and estradiol in early human pregnancy (8th-12th week of gestation) was investigated in volunteers; control group (n = 11), AG group [1000 mg AG orally at test begin (n = 6)]. Venous blood samples were taken at the beginning of the test and 0.5, 1, 2, 4, 8 and 24 h thereafter. In controls, no significant changes in serum progesterone and estradiol could be observed during 24 h. In the AG group, a decrease in progesterone and estradiol could be observed within 1 h after the test began; lowest serum steroid concentrations were reached after 4 h. Relative to the initial values taken as 100%, the greatest decrease in progesterone ranged between 37 and 83%, 62 +/- 15% (means +/- SD)(n = 6); the greatest decrease in estradiol ranged between 32 and 78%, 51 +/- 17% (means +/- SD)(n = 6). Twenty four hours after AG treatment, both steroids reached similar concentrations to those found at test begin. No clinical signs (e.g. uterine bleeding, contractions) for the abortifacient action of AG were observed. In conclusion, a single dose of AG (1000 mg given orally) cannot induce a therapeutic abortion in early pregnancy. In accordance with in vitro studies, the inhibitory effect of AG on placental progesterone formation is due to an inhibition of mitochondrial cholesterol side chain cleavage. The decrease in estradiol is thought to be related to an inhibition of placental aromatase.

  1. Time- and dose-dependent effects of roundup on human embryonic and placental cells.

    PubMed

    Benachour, N; Sipahutar, H; Moslemi, S; Gasnier, C; Travert, C; Séralini, G E

    2007-07-01

    Roundup is the major herbicide used worldwide, in particular on genetically modified plants that have been designed to tolerate it. We have tested the toxicity and endocrine disruption potential of Roundup (Bioforce on human embryonic 293 and placental-derived JEG3 cells, but also on normal human placenta and equine testis. The cell lines have proven to be suitable to estimate hormonal activity and toxicity of pollutants. The median lethal dose (LD(50)) of Roundup with embryonic cells is 0.3% within 1 h in serum-free medium, and it decreases to reach 0.06% (containing among other compounds 1.27 mM glyphosate) after 72 h in the presence of serum. In these conditions, the embryonic cells appear to be 2-4 times more sensitive than the placental ones. In all instances, Roundup (generally used in agriculture at 1-2%, i.e., with 21-42 mM glyphosate) is more efficient than its active ingredient, glyphosate, suggesting a synergistic effect provoked by the adjuvants present in Roundup. We demonstrated that serum-free cultures, even on a short-term basis (1 h), reveal the xenobiotic impacts that are visible 1-2 days later in serum. We also document at lower non-overtly toxic doses, from 0.01% (with 210 microM glyphosate) in 24 h, that Roundup is an aromatase disruptor. The direct inhibition is temperature-dependent and is confirmed in different tissues and species (cell lines from placenta or embryonic kidney, equine testicular, or human fresh placental extracts). Furthermore, glyphosate acts directly as a partial inactivator on microsomal aromatase, independently of its acidity, and in a dose-dependent manner. The cytotoxic, and potentially endocrine-disrupting effects of Roundup are thus amplified with time. Taken together, these data suggest that Roundup exposure may affect human reproduction and fetal development in case of contamination. Chemical mixtures in formulations appear to be underestimated regarding their toxic or hormonal impact.

  2. Aromatase Expression in the Hippocampus of AD Patients and 5xFAD Mice

    PubMed Central

    Prange-Kiel, Janine; Dudzinski, Danuta A.; Pröls, Felicitas; Glatzel, Markus; Matschke, Jakob; Rune, Gabriele M.

    2016-01-01

    Numerous studies show that 17β-estradiol (E2) protects against Alzheimer's disease (AD) induced neurodegeneration. The E2-synthesizing enzyme aromatase is expressed in healthy hippocampi, but although the hippocampus is severely affected in AD, little is known about the expression of hippocampal aromatase in AD. To better understand the role of hippocampal aromatase in AD, we studied its expression in postmortem material from patients with AD and in a mouse model for AD (5xFAD mice). In human hippocampi, aromatase-immunoreactivity was observed in the vast majority of principal neurons and signal quantification revealed higher expression of aromatase protein in AD patients compared to age- and sex-matched controls. The tissue-specific first exons of aromatase I.f, PII, I.3, and I.6 were detected in hippocampi of controls and AD patients by RT-PCR. In contrast, 3-month-old, female 5xFAD mice showed lower expression of aromatase mRNA and protein (measured by qRT-PCR and semiquantitative immunohistochemistry) than WT controls; no such differences were observed in male mice. Our findings stress the importance of hippocampal aromatase expression in neurodegenerative diseases. PMID:27298742

  3. Bisphenol A differentially activates protein kinase C isoforms in murine placental tissue

    SciTech Connect

    Tan, Wenjuan; Huang, Hui; Wang, Yanfei; Wong, Tsz Yan; Wang, C.C.; Leung, Lai K.

    2013-06-01

    Bisphenol A is utilized to make polycarbonate plastics and is an environmental pollutant. Recent research has indicated that it is an endocrine disruptor and may interfere with reproductive processes. Our lab has previously shown that bisphenol A could regulate corticotrophin releasing hormone and aromatase in cultured placental cells. In the present study, the effect of bisphenol A on these two genes in the placenta was investigated in mice. Pregnant ICR mice were gavaged with bisphenol A at 2, 20 and 200 mg/kg body weight/day from E13 to E16 and were euthanized at E17. Compared to the control mice, increased plasma estrogen and corticotrophin releasing hormone were observed in bisphenol A-treated mice. Messenger RNA quantification indicated that placental crh but not cyp19 was induced in mice treated with bisphenol A. Tracking the related signaling pathway, we found that protein kinase C ζ/λ and δ were activated in the placentas of bisphenol A-treated mice. As the gene promoter of crh contains CRE and the half site of ERE, either phospho-PKC or estrogen could stimulate the gene transactivation. These results indicate that bisphenol A might increase plasma concentrations of estradiol, testosterone, corticotrophin releasing hormone and placental phospho-PKC ζ/λ and δ in mice. Ultimately, the incidence of premature birth in these mice could increase. - Highlights: • The pollutant bisphenol A differentially activated PKC isoforms in the placenta. • CRE-binding activity in the nuclear protein of placenta was increased. • Bisphenol A induces CRH mRNA expression in mice.

  4. Developing steroidal aromatase inhibitors-an effective armament to win the battle against breast cancer.

    PubMed

    Yadav, Mange Ram; Barmade, Mahesh A; Tamboli, Riyaj S; Murumkar, Prashant R

    2015-11-13

    Breast cancer, an emerging disease among the women population, occurs due to overexpression of estrogens. The enzyme aromatase plays a key rate limiting role in the biosynthesis of estrogens. Certain clinical advantages of the use of exemestane, a steroidal aromatase inhibitor over non-steroidal aromatase inhibitors have drawn the attention of researchers for the development of novel steroidal aromatase inhibitors.The current review is a humble attempt to compile the reports by various researchers till date on the synthesis of steroidal aromatase inhibitors. It has been tried to encompass the structural modifications carried out by various researchers in the steroid ring system by taking up the functional group modifications on rings A, B, ring A/B junction, ring-D, ring modifications, bridged derivatives and heterocyclic ring-fused derivatives in a systematic way.

  5. Nicotine Blocks Brain Estrogen Synthase (Aromatase): In Vivo Positron Emission Tomography Studies in Female Baboons

    SciTech Connect

    Biegon, A.; Biegon, A.; Kim, S.-W.; Logan, J.; Hooker, J.M.; Muench, L.; Fowler, J.S.

    2010-01-12

    Cigarette smoking and nicotine have complex effects on human physiology and behavior, including some effects similar to those elicited by inhibition of aromatase, the last enzyme in estrogen biosynthesis. We report the first in vivo primate study to determine whether there is a direct effect of nicotine administration on brain aromatase. Brain aromatase availability was examined with positron emission tomography and the selective aromatase inhibitor [{sup 11}C]vorozole in six baboons before and after exposure to IV nicotine at .015 and .03 mg/kg. Nicotine administration produced significant, dose-dependent reductions in [{sup 11}C]vorozole binding. The amygdala and preoptic area showed the largest reductions. Plasma levels of nicotine and its major metabolite cotinine were similar to those found in cigarette smokers. Nicotine interacts in vivo with primate brain aromatase in regions involved in mood, aggression, and sexual behavior.

  6. Association between calcifying nanoparticles and placental calcification

    PubMed Central

    Guo, Yanan; Zhang, Dechun; Lu, He; Luo, Shuang; Shen, Xuecheng

    2012-01-01

    Background The purpose of this study was to examine the possible contribution of calcifying nanoparticles to the pathogenesis of placental calcification. Methods Calcified placental tissues and distal tissue samples were collected from 36 confirmed placental calcification cases. In addition, 20 normal placental tissue samples were obtained as a control group. All the tissue samples were cultured using special nanobacterial culture methods. The cultured calcifying nanoparticles were examined by transmission electron microscopy (TEM), and their growth was monitored by optical density (OD) at a wavelength of 650 nm. 16S rRNA gene expression of the cultured calcifying nanoparticles was also isolated and sequenced. Results Novel calcifying nanoparticles wrapped with electron-dense shells between 50 nm to 500 nm in diameter were observed in the extracellular matrix of calcified placental tissues. They were detected in placental villi and hydroxyapatite crystals, and contained “nucleic acid-like materials”. After isolation and four weeks of culture, 28 of 36 calcified placental tissue samples showed white granular precipitates attached to the bottom of the culture tubes. OD650 measurements indicated that the precipitates from the calcified placental tissues were able to grow in culture, whereas no such precipitates from the control tissues were observed. The 16S rRNA genes were isolated from the cultured calcifying nanoparticles and calcified placental tissues, and their gene sequencing results implied that calcifying nanoparticles were novel nanobacteria (GenBank JF823648). Conclusion Our results suggest that these novel calcifying nanoparticles may play a role in placental calcification. PMID:22615531

  7. Regulation of aromatase expression in breast cancer treated with anastrozole neoadjuvant therapy.

    PubMed

    Ghimenti, Chiara; Mello-Grand, Maurizia; Grosso, Enrico; Scatolini, Maria; Regolo, Lea; Zambelli, Alberto; Chiorino, Giovanna

    2013-03-01

    Aromatase inhibitors (AIs), such as anastrozole, are established in the treatment of hormone-dependent breast cancer. However, ∼20% of patients with hormone receptor-positive breast tumors treated with anastrozole do not respond and it remains impossible to accurately predict sensitivity. Since polymorphisms in the aromatase gene may influence the response to inhibitory drugs, we evaluated the presence of rs6493497 and rs7176005 polymorphisms (mapping in the 5'-flanking region of the CYP19A1 gene coding for the aromatase protein) in a cohort of 37 patients with postmenopausal breast cancer who received three-month neoadjuvant treatment with anastrozole. We then investigated any association of the polymorphisms with changes in aromatase mRNA expression change and/or response to treatment. We also analyzed five miRNAs computationally predicted to target aromatase, to observe any association between their expression and sensitivity to anastrozole. Three samples carried the two polymorphisms and the remaining samples were wild-type for both, however, no association with response or with aromatase mRNA basal expression level or expression difference after therapy was observed. Polymorphic samples that were resistant to anastrozole showed no change or decrease in aromatase expression following AI treatment, whereas an increase in expression was observed for the polymorphic responsive samples. No statistically significant correlation was observed between miRNA and aromatase mRNA expression, or with response to anastrozole neoadjuvant treatment. These data indicate that the polymorphisms analyzed are not involved in aromatase activity and that other epigenetic mechanisms may regulate aromatase protein expression.

  8. Conflict of interest in economic analyses of aromatase inhibitors in breast cancer: a systematic review.

    PubMed

    Jang, Sekwon; Chae, Young Kwang; Haddad, Tufia; Majhail, Navneet S

    2010-06-01

    To determine whether authors conducting economic analyses of aromatase inhibitors in breast cancer are less likely to reach unfavorable conclusions if the economic study is sponsored by the manufacturer of the drug. Articles reporting the economic analyses of aromatase inhibitors in breast cancer were selected from PubMed in May 2009. Information was collected on the types of analysis, the qualitative conclusion, the quantitative results, and the funding sources. Fisher's exact test was conducted to compare the frequency of unfavorable conclusions based on study sponsorship. Thirty-two eligible articles were identified. Twenty-six were funded by pharmaceutical companies, and 4 were funded by non-pharmaceutical companies. Two studies did not report a funding source. Twenty-one studies evaluated aromatase inhibitors in the adjuvant setting, while 11 studies examined their use in advanced breast cancer. Twenty-two studies evaluated one type aromatase inhibitor, while 10 compared multiple types of aromatase inhibitors. Only one of the 26 (4%) pharmaceutical company-sponsored studies reported unfavorable cost-effectiveness of an aromatase inhibitor, which was a competitor's product, whereas two of four (50%) non-pharmaceutical company-sponsored studies concluded aromatase inhibitors are not cost-effective in certain clinical scenarios (P < 0.05). Seven pharmaceutical company-sponsored studies conducted a comparison among several aromatase inhibitors; all 7 studies reported favorable conclusions for the sponsoring company's products. The majority of economic analyses of aromatase inhibitors in breast cancer are sponsored by pharmaceuticals. Economic evaluations of aromatase inhibitors in breast cancer that are funded by a pharmaceutical company are less likely to reach unfavorable conclusions about the sponsor's product.

  9. Aromatase enzyme expression in acromegaly and its possible relationship with disease prognosis.

    PubMed

    Selek, Alev; Cetinarslan, Berrin; Gurbuz, Yesim; Tarkun, Ilhan; Canturk, Zeynep; Cabuk, Burak

    2015-05-01

    The purpose of this study was to evaluate aromatase enzyme expression in growth hormone (GH) secreting adenomas and comparison with prolactinomas, nonfunctional adenomas, and normal pituitary tissues. Also the impact of its expression on clinical and prognostic features was evaluated. 38 acromegaly, 26 prolactinoma, and 31 nonfunctional pituitary adenoma and 11 normal pituitary gland samples from autopsies were included. Aromatase and estrogen receptor-alpha (ERα) were evaluated by Immunohistochemical method; demographic, pre- and postoperative features of the patients were noted. Aromatase was expressed in varying degrees in all cases in study including controls. Aromatase expression in patients with acromegaly was significantly higher than patients with prolactinoma, nonfunctional adenoma, and controls (p = 0.04, p = 0.01 and p < 0.001, respectively). Taken together two functional adenoma groups, prolactinoma and acromegaly, aromatase expression was negatively correlated with ER-alpha (p = 0.02, r = -0.34). Also, Ki-67 immunohistochemical results were negatively correlated with aromatase expression (p = 0.03, r = -0.27) while positively correlated with ER expression (p < 0.01). Consistent with the growing evidence about testosterone effect on pituitary functions, aromatase expression was found to be higher in GH-secreting pituitary adenoma. Aromatase was expressed in all pituitary tissues including autopsy samples; however, it was highest in patients with acromegaly. In patients with acromegaly and prolactinoma, aromatase expression was negatively correlated with Ki-67 score, and also it was higher in patients with complete postoperative remission than without remission. Therefore, aromatase expression may be a good prognostic marker predominantly in acromegaly.

  10. l-Methionine Placental Uptake

    PubMed Central

    Araújo, João R.; Correia-Branco, Ana; Ramalho, Carla; Gonçalves, Pedro; Pinho, Maria J.; Keating, Elisa

    2013-01-01

    Our aim was to investigate the influence of gestational diabetes mellitus (GDM) and GDM-associated conditions upon the placental uptake of 14C-l-methionine (14C-l-Met). The 14C-l-Met uptake by human trophoblasts (TBs) obtained from normal pregnancies (normal trophoblast [NTB] cells) is mainly system l-type amino acid transporter 1 (LAT1 [L])-mediated, although a small contribution of system y+LAT2 is also present. Comparison of 14C-l-Met uptake by NTB and by human TBs obtained from GDM pregnancies (diabetic trophoblast [DTB] cells) reveals similar kinetics, but a contribution of systems A, LAT2, and b0+ and a greater contribution of system y+LAT1 appears to exist in DTB cells. Short-term exposure to insulin and long-term exposure to high glucose, tumor necrosis factor-α, and leptin decrease 14C-l-Met uptake in a human TB (Bewo) cell line. The effect of leptin was dependent upon phosphoinositide 3-kinase, extracellular-signal-regulated kinase 1/2 (ERK/MEK 1/2), and p38 mitogen-activated protein kinase. In conclusion, GDM does not quantitatively alter 14C-l-Met placental uptake, although it changes the nature of transporters involved in that process. PMID:23653387

  11. Intracellular Organisms as Placental Invaders

    PubMed Central

    Vigliani, Marguerite B.; Bakardjiev, Anna I.

    2015-01-01

    In this article we present a novel model for how the human placenta might get infected via the hematogenous route. We present a list of diverse placental pathogens, like Listeria monocytogenes or Cytomegalovirus, which are familiar to most obstetricians, but others, like Salmonella typhi, have only been reported in case studies or small case series. Remarkably, all of these organisms on this list are either obligate or facultative intracellular organisms. These pathogens are able to enter and survive inside host immune cells for at least a portion of their life cycle. We suggest that many blood-borne pathogens might arrive at the placenta via transportation inside of maternal leukocytes that enter the decidua in early pregnancy. We discuss mechanisms by which extravillous trophoblasts could get infected in the decidua and spread infection to other layers in the placenta. We hope to raise awareness among OB/GYN clinicians that organisms not typically associated with the TORCH list might cause placental infections and pregnancy complications.

  12. Compensatory Increase in Ovarian Aromatase in Older Regularly Cycling Women

    PubMed Central

    Shaw, N. D.; Srouji, S. S.; Welt, C. K.; Cox, K. H.; Fox, J. H.; Adams, J. A.; Sluss, P. M.

    2015-01-01

    Context: Serum estradiol (E2) levels are preserved in older reproductive-aged women with regular menstrual cycles despite declining ovarian function. Objective: The objective of the study was to determine whether increased granulosa cell aromatase expression and activity account for preservation of E2 levels in older, regularly cycling women. Design: The protocol included daily blood sampling and dominant follicle aspirations at an academic medical center during a natural menstrual cycle. Subjects: Healthy, regularly cycling older (36–45 y; n = 13) and younger (22–34 y; n = 14) women participated in the study. Main Outcome Measures: Hormone levels were measured in peripheral blood and follicular fluid aspirates and granulosa cell CYP19A1 (aromatase) and FSH-R mRNA expression were determined. Results: Older women had higher FSH levels than younger women during the early follicular phase with similar E2 but lower inhibin B and antimullerian hormone levels. Late follicular phase serum E2 did not differ between the two groups. Follicular fluid E2 [older (O) = 960.0 [interquartile range (IQR) 765.0–1419.0]; younger (Y) = 994.5 [647.3–1426.5] ng/mL, P = 1.0], estrone (O = 39.6 [29.5–54.1]; Y = 28.8 [22.5–42.1] ng/mL, P = 0.3), and the E2 to testosterone (T) ratio (O = 109.0 ± 41.9; Y = 83.0 ± 18.6, P = .50) were preserved in older women. Granulosa cell CYP19A1 expression was increased 3-fold in older compared with younger women (P < .001), with no difference in FSH-R expression. Conclusions: Ovarian aromatase expression increases with age in regularly cycling women. Thus, up-regulation of aromatase activity appears to compensate for the known age-related decrease in granulosa cell number in the dominant follicle to maintain ovarian estrogen production in older premenopausal women. PMID:26126208

  13. 21 CFR 862.1585 - Human placental lactogen test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Human placental lactogen test system. 862.1585... Systems § 862.1585 Human placental lactogen test system. (a) Identification. A human placental lactogen test system is a device intended to measure the hormone human placental lactogen (HPL), (also known...

  14. 21 CFR 862.1585 - Human placental lactogen test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Human placental lactogen test system. 862.1585... Systems § 862.1585 Human placental lactogen test system. (a) Identification. A human placental lactogen test system is a device intended to measure the hormone human placental lactogen (HPL), (also known...

  15. A stochastic model for early placental development†

    PubMed Central

    Cotter, Simon L.; Klika, Václav; Kimpton, Laura; Collins, Sally; Heazell, Alexander E. P.

    2014-01-01

    In the human, placental structure is closely related to placental function and consequent pregnancy outcome. Studies have noted abnormal placental shape in small-for-gestational-age infants which extends to increased lifetime risk of cardiovascular disease. The origins and determinants of placental shape are incompletely understood and are difficult to study in vivo. In this paper, we model the early development of the human placenta, based on the hypothesis that this is driven by a chemoattractant effect emanating from proximal spiral arteries in the decidua. We derive and explore a two-dimensional stochastic model, and investigate the effects of loss of spiral arteries in regions near to the cord insertion on the shape of the placenta. This model demonstrates that disruption of spiral arteries can exert profound effects on placental shape, particularly if this is close to the cord insertion. Thus, placental shape reflects the underlying maternal vascular bed. Abnormal placental shape may reflect an abnormal uterine environment, predisposing to pregnancy complications. Through statistical analysis of model placentas, we are able to characterize the probability that a given placenta grew in a disrupted environment, and even able to distinguish between different disruptions. PMID:24850904

  16. Novel sulfonanilide analogs decrease aromatase activity in breast cancer cells: synthesis, biological evaluation, and ligand-based pharmacophore identification.

    PubMed

    Su, Bin; Tian, Ran; Darby, Michael V; Brueggemeier, Robert W

    2008-03-13

    Aromatase converts androgens to estrogens and is a particularly attractive target in the treatment of estrogen receptor positive breast cancer. Previously, the COX-2 selective inhibitor nimesulide and analogs decreased aromatase expression and enzyme activity independent of COX-2 inhibition. In this manuscript, a combinatorial approach was used to generate diversely substituted novel sulfonanilides by parallel synthesis. Their pharmacological evaluation as agents for suppression of aromatase activity in SK-BR-3 breast cancer cells was extensively explored. A ligand-based pharmacophore model was elaborated for selective aromatase modulation (SAM) using the Catalyst HipHop algorithms. The best qualitative model consisted of four features: one aromatic ring, two hydrogen bond acceptors, and one hydrophobic function. Several lead compounds have also been tested in aromatase transfected MCF-7 cells, and they significantly suppressed cellular aromatase activity. The results suggest that both genomic and nongenomic mechanisms of these compounds are involved within the aromatase suppression effect. PMID:18271519

  17. Novel sulfonanilide analogs decrease aromatase activity in breast cancer cells: synthesis, biological evaluation, and ligand-based pharmacophore identification.

    PubMed

    Su, Bin; Tian, Ran; Darby, Michael V; Brueggemeier, Robert W

    2008-03-13

    Aromatase converts androgens to estrogens and is a particularly attractive target in the treatment of estrogen receptor positive breast cancer. Previously, the COX-2 selective inhibitor nimesulide and analogs decreased aromatase expression and enzyme activity independent of COX-2 inhibition. In this manuscript, a combinatorial approach was used to generate diversely substituted novel sulfonanilides by parallel synthesis. Their pharmacological evaluation as agents for suppression of aromatase activity in SK-BR-3 breast cancer cells was extensively explored. A ligand-based pharmacophore model was elaborated for selective aromatase modulation (SAM) using the Catalyst HipHop algorithms. The best qualitative model consisted of four features: one aromatic ring, two hydrogen bond acceptors, and one hydrophobic function. Several lead compounds have also been tested in aromatase transfected MCF-7 cells, and they significantly suppressed cellular aromatase activity. The results suggest that both genomic and nongenomic mechanisms of these compounds are involved within the aromatase suppression effect.

  18. Isolation and Characterization of Aromatase Inhibitors from Brassaiopsis glomerulata (Araliaceae)

    PubMed Central

    Balunas, Marcy J.; Su, Bin; Riswan, Soedarsono; Fong, Harry H.S.; Brueggemeier, Robert W.; Pezzuto, John M.; Kinghorn, A. Douglas

    2009-01-01

    The hexane- and ethyl acetate-soluble extracts of the leaves of Brassaiopsis glomerulata (Blume) Regel (Araliaceae), collected in Indonesia, were found to inhibit aromatase, the rate-limiting enzyme in the production of estrogens from androgens, in both enzyme- and cell-based aromatase inhibition (AI) assays. Bioassay-guided fractionation led to the isolation of six known compounds of the steroid and triterpenoid classes (1–6) from the hexane extract, of which 6β-hydroxystimasta-4-en-3-one (5), was moderately active in the cell-based AI assay. Fractionation of the ethyl acetate extract afforded seven pure isolates (7–13) of the modified peptide, fatty acid, monoterpenoid, and benzenoid types, including six known compounds and the new natural product, N-benzoyl-L-phenylalanine methyl ester (9). The absolute stereochemistry of 9 and the other two peptides, 7 and 8, was determined by Marfey’s analysis. Linoleic acid (10) was found to be active in the enzyme-based AI assay, while 9 and (−)-dehydrololiolide (12) showed activity in the cell-based AI assay. PMID:20161072

  19. Postpartum deaths: piglet, placental, and umbilical characteristics.

    PubMed

    Rootwelt, V; Reksen, O; Farstad, W; Framstad, T

    2013-06-01

    The fetal growth of the piglet is highly dependent on its placenta, and the newborn piglet birth weight is highly associated with postpartum death. However, there is little information available in the literature on the assessment of the placenta in relation to postpartum death in piglets. The aim of this study was to evaluate the impact of the placental area and placental weight, status of the umbilical cord, and piglet birth characteristics, such as blood parameters, vitality score, and birth weight on postpartum death. All live born piglets in litters from 26 Landrace-Yorkshire sows were monitored during farrowing and the status of each was recorded, including placental area and placental weight and blood variables obtained from the piglets and umbilical veins. Out of the 386 live-born piglets, 16.8% died before weaning at 5 wk. Among these, 78.5% died within the first 3 d of life. Mean blood concentration of lactate was increased in piglets that did not survive to weaning (P = 0.003). Concentrations of hemoglobin and hematocrit were decreased (P < 0.001) compared with survivors. Piglets born with a broken umbilical cord had a reduced vitality score vs. piglets born with an intact umbilical cord (P = 0.021), and they had an increased probability of dying before weaning (P = 0.050). Mean birth weight, body mass index, placental area (P < 0.001), and placental weight (P = 0.020) were reduced in piglets that died before weaning vs. those that survived. Birth weight and placental area were furthermore negatively associated with live litter size. Blood concentrations of IgG and albumin recorded at d 1 were decreased in piglets that died before weaning (P < 0.01), and blood concentration of albumin was positively associated with placental area (P < 0.001). We conclude that placental area and placental weight, status of the umbilical cord, birth weight, body mass index, blood concentrations of lactate, hemoglobin, and hematocrit recorded at birth, and blood

  20. Simulation of multihaem cytochromes.

    PubMed

    Soares, Cláudio M; Baptista, António M

    2012-03-01

    This article presents an overview of the simulation studies of the behaviour of multihaem cytochromes using theoretical/computational methodologies, with an emphasis on cytochrome c(3). It starts with the first studies using rigid molecules and continuum electrostatic models, where protonation and redox events were treated as independent. The gradual addition of physical details is then described, from the inclusion of proton isomerism, to the proper treatment of the thermodynamics of electron-proton coupling, to the explicit inclusion of the solvent and protein structural reorganization into the models, culminating with the method for molecular dynamics simulations at constant pH and reduction potential, where the solvation, conformational, protonation and redox features are all simulated in a fully integrated and coupled way. We end with a discussion of the strategies used to study the interaction between multihaem cytochromes, taking into account the further coupling effect introduced by the molecular association.

  1. IKKbeta mediates cell shape-induced aromatase expression and estrogen biosynthesis in adipose stromal cells.

    PubMed

    Ghosh, Sagar; Choudary, Ahsan; Ghosh, Sangeeta; Musi, Nicolas; Hu, Yanfen; Li, Rong

    2009-05-01

    Aromatase (Cyp19) is a key enzyme in estrogen biosynthesis and an important target in breast cancer therapy. Within tumor microenvironment, tumor cells stimulate aromatase expression in adipose stromal cells (ASCs), which in turn promotes estrogen-dependent growth of estrogen receptor (ER)-positive tumor cells. However, it is not clear how aromatase transcription and estrogen biosynthesis are regulated in ASCs under a precancerous condition. Here we demonstrate that cell shape change alone is sufficient to induce aromatase expression in primary ASCs from cancer-free individuals. The activation of aromatase transcription is mediated by IkappaB kinase-beta (IKKbeta), a kinase previously known for its cancer-promoting activity in tumor cells. Activation of IKKbeta leads to elevated expression of transcription factor CCAAT/enhancer-binding protein-beta (C/EBPbeta), which binds to and stimulates two breast cancer-associated promoters of the aromatase gene. We also show that shape-induced estrogen production in ASCs can stimulate estrogen-dependent transcription in ER-positive breast tumor cells. We suggest that IKKbeta-dependent aromatase induction due to changes in cellular architecture in adipose tissue may contribute to the breast cancer risks associated with high mammagraphic density and obesity.

  2. Placental Genome and Maternal-Placental Genetic Interactions: A Genome-Wide and Candidate Gene Association Study of Placental Abruption

    PubMed Central

    Denis, Marie; Enquobahrie, Daniel A.; Tadesse, Mahlet G.; Gelaye, Bizu; Sanchez, Sixto E.; Salazar, Manuel; Ananth, Cande V.; Williams, Michelle A.

    2014-01-01

    While available evidence supports the role of genetics in the pathogenesis of placental abruption (PA), PA-related placental genome variations and maternal-placental genetic interactions have not been investigated. Maternal blood and placental samples collected from participants in the Peruvian Abruptio Placentae Epidemiology study were genotyped using Illumina’s Cardio-Metabochip platform. We examined 118,782 genome-wide SNPs and 333 SNPs in 32 candidate genes from mitochondrial biogenesis and oxidative phosphorylation pathways in placental DNA from 280 PA cases and 244 controls. We assessed maternal-placental interactions in the candidate gene SNPS and two imprinted regions (IGF2/H19 and C19MC). Univariate and penalized logistic regression models were fit to estimate odds ratios. We examined the combined effect of multiple SNPs on PA risk using weighted genetic risk scores (WGRS) with repeated ten-fold cross-validations. A multinomial model was used to investigate maternal-placental genetic interactions. In placental genome-wide and candidate gene analyses, no SNP was significant after false discovery rate correction. The top genome-wide association study (GWAS) hits were rs544201, rs1484464 (CTNNA2), rs4149570 (TNFRSF1A) and rs13055470 (ZNRF3) (p-values: 1.11e-05 to 3.54e-05). The top 200 SNPs of the GWAS overrepresented genes involved in cell cycle, growth and proliferation. The top candidate gene hits were rs16949118 (COX10) and rs7609948 (THRB) (p-values: 6.00e-03 and 8.19e-03). Participants in the highest quartile of WGRS based on cross-validations using SNPs selected from the GWAS and candidate gene analyses had a 8.40-fold (95% CI: 5.8–12.56) and a 4.46-fold (95% CI: 2.94–6.72) higher odds of PA compared to participants in the lowest quartile. We found maternal-placental genetic interactions on PA risk for two SNPs in PPARG (chr3∶12313450 and chr3∶12412978) and maternal imprinting effects for multiple SNPs in the C19MC and IGF2/H19 regions

  3. Suppression of aromatase activity in populations of bream (Abramis brama) from the river Elbe, Germany.

    PubMed

    Hecker, Markus; Sanderson, J Thomas; Karbe, Ludwig

    2007-01-01

    Aromatase activity was determined in brain and gonads of wild bream collected along the river Elbe, Germany, and correlated with other endocrine and reproductive endpoints such as plasma sex steroid concentrations, secondary sex characteristics (STI), plasma vitellogenin, gonad size (GSI), and maturation stages of germ cells (MS) that were reported for the same fish in a previous study. Furthermore, regional patterns of aromatase activity were correlated to a number of environmental factors such as exposure to environmental contaminants and parasitism. While aromatase activity was not detectable in the gonads of male and female fish with the assay used, fish of both genders revealed relatively great brain enzyme activities. As for most of the endocrine and reproductive parameters, with the exception of plasma testosterone (T), aromatase activities were significantly less in fish from a river stretch characterized by elevated exposures to organic contaminants and metals. Brain aromatase activity was positively and significantly correlated with plasma estradiol (E2) and MS in females, and showed a similar trend with plasma 11-ketotestosterone (11KT) and STI in males. No comparable trend occurred for T. This decrease of the reproductively relevant hormones 11KT and E2 may be indicative of a disruption of the last step in sex hormone synthesis, a hypothesis that was supported for E2 by the strong (R2=0.78, p<0.05) linear regression between aromatase activity and E2 in female bream. It is also hypothesized that the effects on brain aromatase activity were likely to be related to the disruption of other reproductive parameters including sexual maturity and expression of secondary sex characteristics. Although a number of factors such as exposure to pollutants and prevalence of the tapeworm Ligula intestinalis correlated with the suppression of aromatase activity, the exact causes for the regional decrease in brain aromatase activity remain unclear due to inconsistencies

  4. Placental hypoxia: the lesions of maternal malperfusion.

    PubMed

    Parks, W Tony

    2015-02-01

    The placental lesions classically ascribed to placental hypoxia, here denoted maternal malperfusion (MMP), are among the more significant that a placental pathologist may encounter. Yet the appearance of these lesions may be subtle, and the clinical implication of their diagnosis is frequently unclear. The aim of this review is to provide a more nuanced perspective on the clinical utility of placental pathology for the detection of MMP. The review will first detail MMP lesions in the placenta and discuss their associations with pregnancy complications. The review will then delve into the diagnostic and interpretive difficulties of these lesions. Finally, recent research findings that may aid in the development of better diagnostic tools will be briefly discussed.

  5. Is assisted reproduction associated with abnormal placentation?

    PubMed

    Joy, Jolly; Gannon, Caroline; McClure, Neil; Cooke, Inez

    2012-01-01

    Artificial reproductive technologies (ART) and conception following a period of untreated infertility (>1 year) are independently associated with increased pregnancy complications in both singleton and multiple pregnancies. It is unknown if placental dysfunction associated with macroscopic and/or microscopic histological discrepancies might explain some of these variances. Our aim was to compare the histopathology of placentae from singleton pregnancies belonging to 3 groups, as follows: conception as a result of ART; spontaneous conception (<1 year of trying); and conception following untreated infertility (>1 year). Pathological examination of placentae from singleton pregnancies of nonsmoking, age-matched primiparous women with no significant medical history and no known uterine congenital anomalies was performed by a single pathologist blinded to the groups. Features were compared using analysis of variance and chi-square tests. A total of 89 placental pathology reports were available (control  =  39, infertility  =  17, ART  =  33). The mean placental thickness was significantly higher in the ART group when compared to the spontaneous conception group (P  =  0.02). There were significantly more placental hematomas in the ART group (P  =  0.04) compared to the other groups. There were no significant differences in rates of abnormal placental shapes or abnormal cord insertions. There were no statistically significant differences in the incidence of microscopic placental lesions, nor were there any statistically significant differences in the incidence of macroscopic and microscopic placental lesions between the infertility group and the other groups. Placentae of ART pregnancies show significantly increased thickness and a higher incidence of hematomas. Increased placental thickness has previously been linked to increased perinatal risk.

  6. Comparative aspects of trophoblast development and placentation

    PubMed Central

    Carter, Anthony M; Enders, Allen C

    2004-01-01

    Based on the number of tissues separating maternal from fetal blood, placentas are classified as epitheliochorial, endotheliochorial or hemochorial. We review the occurrence of these placental types in the various orders of eutherian mammals within the framework of the four superorders identified by the techniques of molecular phylogenetics. The superorder Afrotheria diversified in ancient Africa and its living representatives include elephants, sea cows, hyraxes, aardvark, elephant shrews and tenrecs. Xenarthra, comprising armadillos, anteaters and sloths, diversified in South America. All placentas examined from members of these two oldest superorders are either endotheliochorial or hemochorial. The superorder Euarchontoglires includes two sister groups, Glires and Euarchonta. The former comprises rodents and lagomorphs, which typically have hemochorial placentas. The most primitive members of Euarchonta, the tree shrews, have endotheliochorial placentation. Flying lemurs and all higher primates have hemochorial placentas. However, the lemurs and lorises are exceptional among primates in having epitheliochorial placentation. Laurasiatheria, the last superorder to arise, includes several orders with epitheliochorial placentation. These comprise whales, camels, pigs, ruminants, horses and pangolins. In contrast, nearly all carnivores have endotheliochorial placentation, whilst bats have endotheliochorial or hemochorial placentas. Also included in Laurasiatheria are a number of insectivores that have many conserved morphological characters; none of these has epitheliochorial placentation. Consideration of placental type in relation to the findings of molecular phylogenetics suggests that the likely path of evolution in Afrotheria was from endotheliochorial to hemochorial placentation. This is also a likely scenario for Xenarthra and the bats. We argue that a definitive epitheliochorial placenta is a secondary specialization and that it evolved twice, once in the

  7. The distinct proteome of placental malaria parasites.

    SciTech Connect

    Fried, Michal; Hixson, Kim K.; Anderson, Lori; Ogata, Yuko; Mutabingwa, Theonest K.; Duffy, Patrick E.

    2007-09-01

    Malaria proteins expressed on the surface of Plasmodium falciparum infected erythrocytes (IE) mediate adhesion and are targeted by protective immune responses. During pregnancy, IE sequester in the placenta. Placental IE bind to the molecule chondroitin sulfate A (CSA) and preferentially transcribe the gene that encodes VAR2CSA, a member of the PfEMP1 variant surface antigen family. Over successive pregnancies women develop specific immunity to CSA-binding IE and antibodies to VAR2CSA. We used tandem mass spectrometry together with accurate mass and time tag technology to study IE membrane fractions of placental parasites. VAR2CSA peptides were detected in placental IE and in IE from children, but the MC variant of VAR2CSA was specifically associated with placental IE. We identified six conserved hypothetical proteins with putative TM or signal peptides that were exclusively expressed by the placental IE, and 11 such proteins that were significantly more abundant in placental IE. One of these hypothetical proteins, PFI1785w, is a 42kDa molecule detected by Western blot in parasites infecting pregnant women but not those infecting children.

  8. Localization of the aromatase enzyme expression in the human pituitary gland and its effect on growth hormone, prolactin, and thyroid stimulating hormone axis.

    PubMed

    Caglar, Asli Sezgin; Kapucu, Aysegul; Dar, Kadriye Akgun; Ozkaya, Hande Mefkure; Caglar, Erkan; Ince, Haluk; Kadioglu, Pinar

    2015-08-01

    The aim of this study is to evaluate aromatase expression in prolactin (PRL), thyroid stimulating hormone (TSH), and growth hormone (GH) secreting cells. Nontumoral human pituitary specimens were obtained from autopsy samples. Aromatase co-expression was determined by double immunohistochemical staining and assessed using H scores. H scores for GH-aromatase co-expression (GH-aromatase), TSH-aromatase co-expression (TSH-aromatase), and PRL-aromatase co-expression (PRL-aromatase) were 83.1 ± 13.1, 95.6 ± 16.1, and 83.7 ± 14.5, respectively. TSH producing cells exhibited the highest H score for co-expression of aromatase (p < 0.001). There was no gender difference in terms of H scores for aromatase expression and double immunohistochemical staining results (p > 0.05 for all). There was a negative correlation between the H scores for aromatase and PRL-aromatase, GH-aromatase and TSH-aromatase, respectively (r = -0.592, p < 0.001; r = -0.593, p < 0.001; r = -0.650, p < 0.001, respectively). Also, H scores for aromatase co-expression of each hormone were negatively correlated with the H scores for the corresponding hormone (r = -0.503, p < 0.001 for PRL-aromatase and PRL; r = -0.470, p < 0.001 for GH-aromatase, and GH; r = -0.641, p < 0.001 for TSH-aromatase and TSH). H scores for mean aromatase, GH-aromatase, TSH-aromatase were invariant of age (p > 0.05 for all). Age was negatively correlated with PRL-aromatase H score (r = -0.373, p = 0.008). Our study demonstrated significant aromatase co-expression in PRL, GH, and TSH secreting cells of the human anterior pituitary gland. The mutual paracrinal regulation between aromatase and three adenohypophyseal hormones indicates that aromatase may have a regulatory role on the synthesis and secretion of these hormones.

  9. A Quantative Adverse Outcome Pathway Linking Aromatase Inhibition in Fathead Minnows with Population Dynamics

    EPA Science Inventory

    A Quantitative Adverse Outcome Pathway Linking Aromatase Inhibition in Fathead Minnows with Population DynamicsAn adverse outcome pathway (AOP) is a qualitative description linking a molecular initiating event (MIE) with measureable key events leading to an adverse outcome (AO). ...

  10. Use of Network Inference to Unravel the Mechanisms of Action and Specificity of Aromatase Inhibitors

    EPA Science Inventory

    The vertebrate hypothalamus-pituitary-gonadal (HPG) axis is controlled through various feedback mechanisms in order to maintain a dynamic homeostasis during changing environmental conditions, including exposure to chemical stressors. In this study, three aromatase inhibitors, fad...

  11. Technical comment on "The placental mammal ancestor and the post-K-Pg radiation of placentals".

    PubMed

    Springer, Mark S; Meredith, Robert W; Teeling, Emma C; Murphy, William J

    2013-08-01

    O'Leary et al. (Research Article, 8 February 2013, p. 662) examined mammalian relationships and divergence times and concluded that a single placental ancestor crossed the Cretaceous-Paleogene (K-Pg) boundary. This conclusion relies on phylogenetic analyses that fail to discriminate between homology and homoplasy and further implies virus-like rates of nucleotide substitution in early Paleocene placentals. PMID:23929967

  12. Potential role of aromatase inhibitors in the treatment of endometriosis.

    PubMed

    Abu Hashim, Hatem

    2014-01-01

    Endometriosis is an estrogen-dependent chronic inflammatory disease affecting 5%-10% of reproductive-age women, with a prevalence of 5%-50% in infertile women and >33% of women with chronic pelvic pain. Third-generation aromatase inhibitors (AIs) are approved adjuvants for the treatment of estrogen receptor-positive breast cancer. Molecular studies have revealed the presence of aromatase P450, the key enzyme in the biosynthesis of ovarian estradiol, inside the endometriotic tissue, indicating local synthesis of estradiol. Thereby, AIs represent an appealing medical option for the management of different aspects of this enigmatic disease, especially pelvic pain and infertility. Accordingly, this review aims to evaluate the potential role of AIs in the treatment of endometriosis-associated symptoms, mainly pain and infertility. Notably, several studies have demonstrated that the combination of AIs with conventional therapy as oral contraceptive pills, progestins, or gonadotropin-releasing hormone analogs can be used to control endometriosis-associated pain and pain recurrence in premenopausal women, particularly those with pain due to rectovaginal endometriosis refractory to other medical or surgical treatment. Some case reports have shown promising results in the treatment of postmenopausal endometriosis as first-line treatment, when surgery is contraindicated, or as second-line treatment in the case of postoperative recurrence. Third-generation AIs, especially letrozole, have challenged clomiphene citrate as an ovulation-induction agent in patients with polycystic ovary syndrome and in cases of unexplained infertility. However, few studies are available regarding the use of AIs to treat endometriosis-associated infertility. Therefore, larger multicenter randomized trials using AIs for the treatment of endometriosis-associated infertility are needed to clarify its effect. The safety of AIs for ovulation induction or superovulation has generated a lively discussion

  13. Effects of butachlor on estrogen receptor, vitellogenin and P450 aromatase gene expression in the early life stage of zebrafish.

    PubMed

    Chang, Juhua; Gui, Wenjun; Wang, Minghua; Zhu, Guonian

    2012-01-01

    Butachlor has adverse effects on fecundity and disrupts sex hormone homeostasis in adult zebrafish, but the underlying molecular mechanisms are still unclear. In the present study, zebrafish (Danio rerio) embryos were exposed to various concentrations of butachlor from 2 h post-fertilization (hpf) to 30 days post-fertilization (dpf). The transcription of genes involved estrogen receptors (ERα, ERβ1 and ERβ2), vitellogenins (VTG I and II), and cytochrome P450 aromatase (CYP19a) was analyzed by real-time quantitative PCR. The results showed that there was no significant alteration in the expression of VTGI, ERα, ERβ1, ERβ2 and CYP19a after 30 days of butachlor exposure, whereas the transcription of VTG II gene was significantly up-regulated in zebrafish exposed to 100 μg/L butachlor. It is suggested that butachlor may be a weak estrogen, and more endpoints need to be investigated to assess the effects of butachlor on the hypothalamus-pituitary-gonadal axis of zebrafish.

  14. P450 aromatase: a key enzyme in the spermatogenesis of the Italian wall lizard, Podarcis sicula.

    PubMed

    Rosati, Luigi; Agnese, Marisa; Di Fiore, Maria Maddalena; Andreuccetti, Piero; Prisco, Marina

    2016-08-01

    P450 aromatase is a key enzyme in steroidogenesis involved in the conversion of testosterone into 17β-estradiol. We investigated the localization and the expression of P450 aromatase in Podarcis sicula testes during the different phases of the reproductive cycle: summer stasis (July-August), early autumnal resumption (September), middle autumnal resumption (October-November), winter stasis (December-February), spring resumption (March-April) and the reproductive period (May-June). Using immunohistochemistry, we demonstrated that the P450 aromatase is always present in somatic and germ cells of P. sicula testis, particularly in spermatids and spermatozoa, except in early autumnal resumption, when P450 aromatase is evident only within Leydig cells. Using real-time PCR and semi-quantitative blot investigations, we also demonstrated that both mRNA and protein were expressed in all phases, with two peaks of expression occurring in summer and in winter stasis. These highest levels of P450 aromatase are in line with the increase of 17β-estradiol, responsible for the spermatogenesis block typical of this species. Differently, in autumnal resumption, the level of P450 aromatase dramatically decreased, along with 17β-estradiol levels, and testosterone titres increased, responsible for the subsequent renewal of spermatogenesis not followed by spermiation. In spring resumption and in the reproductive period we found intermediate P450 aromatase amounts, low levels of 17β-estradiol and the highest testosterone levels determining the resumption of spermatogenesis needed for reproduction. Our results, the first collected in a non-mammalian vertebrate, indicate a role of P450 aromatase in the control of steroidogenesis and spermatogenesis, particularly in spermiogenesis. PMID:27489219

  15. Aromatase activity of ovine follicular walls: technical validation and physiological control.

    PubMed

    Driancourt, M A; Paris, A; Debrauwer, L

    1996-01-01

    Since aromatase activity quickly disappears in cultured sheep granulosa cells, its control is poorly understood. As a result, an aromatase assay was developed using cultures of follicular walls and measuring the amount of 3H2O generated from 3H-testosterone. Chromatography and mass spectrometry analysis demonstrated that 3H2O production was indeed associated with the production of oestradiol-17 beta. Optimization of the assay demonstrated: (1) a steady increase in the amount of 3H2O produced over at least 12 h; and (2) highly significant correlations between the amounts of 3H2O measured and the weight of the follicular wall or the amount of 3H-testosterone provided. Furthermore, a highly significant correlation (r = 0.82) was observed between the amount of 3H2O produced and the concentration of oestradiol in the same samples. The effects of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and oestradiol on aromatization by follicles at two specific stages of maturation (recruitment, 12 h after luteolysis; dominance, 36 h after luteolysis) were then assessed. At recruitment and dominance, FSH was able to modulate aromatase activity similarly, increasing and decreasing the activity at low concentrations and high concentrations respectively. At recruitment and dominance, oestradiol had no stimulatory effect on basal aromatase activity and even blocked the stimulatory effects of FSH on aromatase at recruitment. LH significantly inhibited the FSH-stimulated aromatase activity of dominant follicles. It is concluded that: (1) FSH may induce the recruitment of follicles by increasing aromatase activity; and (2) neither oestradiol nor LH stimulate the aromatase activity of follicles which could explain maintenance of the dominant follicle. PMID:8876047

  16. Two aromatase inhibitors inhibit the ability of a third to promote mating in male rats.

    PubMed

    Yahr, Pauline

    2015-09-01

    Aromatase, the enzyme that aromatizes androstenedione (A) to estrone and testosterone (T) to estradiol (E), affects androgen control of male sex behavior in many vertebrates. In male monkeys, rats and quail, E mimics the ability of T to promote mating, and aromatase inhibitors block mating induced by T but not E. Aromatase inhibitors include androgens with different A-rings than T and A, e.g., 1,4,6-androstatriene-3,17-dione (ATD), azoles, e.g., fadrozole, and androgens α-halogenated at carbon 6, e.g., 6α-bromoA, 6α-fluoroA and 6α-fluoroT. 6α-FluoroT is the only 6α-halogenated androgen studied in regard to mating. It promotes mating in male rats and quail and was studied, before it was known to inhibit aromatase, because it cannot be aromatized yet has the same A-ring as T. 6α-FluoroT might promote mating by binding estrogen receptors (ER) directly, i.e., unassisted, or by metabolism to an androgen that binds ER. Since neither process would require aromatase, this study tested both hypotheses by determining how mating induced in castrated male rats by 6α-fluoroT is affected by ATD and fadrozole. Both aromatase inhibitors inhibited the effects of 6α-fluoroT on mating. Thus, 6α-fluoroT does not promote mating by direct ER binding or metabolism to another androgen. Since aromatase underlies a process in which 6α-fluoroT, unlike most nonaromatizable androgens, mimics T effects on male sex behavior, the process must involve a feature that 6α-fluoroT shares with T but not other nonaromatizable androgens. A-ring structure is a candidate. A hypothesis is also offered for how aromatase may participate without aromatizing the androgen.

  17. Mosaic retroposon insertion patterns in placental mammals

    PubMed Central

    Churakov, Gennady; Kriegs, Jan Ole; Baertsch, Robert; Zemann, Anja; Brosius, Jürgen; Schmitz, Jürgen

    2009-01-01

    One and a half centuries after Charles Darwin and Alfred Russel Wallace outlined our current understanding of evolution, a new scientific era is dawning that enables direct observations of genetic variation. However, pure sequence-based molecular attempts to resolve the basal origin of placental mammals have so far resulted only in apparently conflicting hypotheses. By contrast, in the mammalian genomes where they were highly active, the insertion of retroelements and their comparative insertion patterns constitute a neutral, virtually homoplasy-free archive of evolutionary histories. The “presence” of a retroelement at an orthologous genomic position in two species indicates their common ancestry in contrast to its “absence” in more distant species. To resolve the placental origin controversy we extracted ∼2 million potentially phylogenetically informative, retroposon-containing loci from representatives of the major placental mammalian lineages and found highly significant evidence challenging all current single hypotheses of their basal origin. The Exafroplacentalia hypothesis (Afrotheria as the sister group to all remaining placentals) is significantly supported by five retroposon insertions, the Epitheria hypothesis (Xenarthra as the sister group to all remaining placentals) by nine insertion patterns, and the Atlantogenata hypothesis (a monophyletic clade comprising Xenarthra and Afrotheria as the sister group to Boreotheria comprising all remaining placentals) by eight insertion patterns. These findings provide significant support for a “soft” polytomy of the major mammalian clades. Ancestral successive hybridization events and/or incomplete lineage sorting associated with short speciation intervals are viable explanations for the mosaic retroposon insertion patterns of recent placental mammals and for the futile search for a clear root dichotomy. PMID:19261842

  18. Mosaic retroposon insertion patterns in placental mammals.

    PubMed

    Churakov, Gennady; Kriegs, Jan Ole; Baertsch, Robert; Zemann, Anja; Brosius, Jürgen; Schmitz, Jürgen

    2009-05-01

    One and a half centuries after Charles Darwin and Alfred Russel Wallace outlined our current understanding of evolution, a new scientific era is dawning that enables direct observations of genetic variation. However, pure sequence-based molecular attempts to resolve the basal origin of placental mammals have so far resulted only in apparently conflicting hypotheses. By contrast, in the mammalian genomes where they were highly active, the insertion of retroelements and their comparative insertion patterns constitute a neutral, virtually homoplasy-free archive of evolutionary histories. The "presence" of a retroelement at an orthologous genomic position in two species indicates their common ancestry in contrast to its "absence" in more distant species. To resolve the placental origin controversy we extracted approximately 2 million potentially phylogenetically informative, retroposon-containing loci from representatives of the major placental mammalian lineages and found highly significant evidence challenging all current single hypotheses of their basal origin. The Exafroplacentalia hypothesis (Afrotheria as the sister group to all remaining placentals) is significantly supported by five retroposon insertions, the Epitheria hypothesis (Xenarthra as the sister group to all remaining placentals) by nine insertion patterns, and the Atlantogenata hypothesis (a monophyletic clade comprising Xenarthra and Afrotheria as the sister group to Boreotheria comprising all remaining placentals) by eight insertion patterns. These findings provide significant support for a "soft" polytomy of the major mammalian clades. Ancestral successive hybridization events and/or incomplete lineage sorting associated with short speciation intervals are viable explanations for the mosaic retroposon insertion patterns of recent placental mammals and for the futile search for a clear root dichotomy. PMID:19261842

  19. Expression patterns of placental microRNAs

    PubMed Central

    Mouillet, Jean-Francois; Chu, Tianjiao; Sadovsky, Yoel

    2016-01-01

    Among different types of small RNA molecules, distinct types of microRNAs (miRNAs) are expressed in many cell types, where they modulate RNA stability and translation, thus controlling virtually every aspect of tissue development, proliferation, differentiation, and function. Aberrant miRNA expression has been linked to discrete pathological processes. As the placenta plays a pivotal role in governing fetal development, it is not surprising that the placenta expresses numerous types of miRNAs. Whereas many of these miRNAs are ubiquitously expressed, certain miRNA species are largely unique to the placenta. Research in the field of placental miRNAs is in its early phase, with most studies centering on cataloging placental miRNA species or examining differences in placental miRNA expression between placentas from normal pregnancies and those from pregnancies complicated by pathologies that are associated with placental dysfunction. Recent research endeavors ventured to assess the function of miRNAs in cultured placental trophoblasts, using in vitro conditions that model relevant pathophysiological processes. The impact of miRNA-mediated repression on the trophoblast transcriptome, particularly in response to genetic and environmental perturbations, remains largely unknown. Further in depth studies are required to unravel the functional significance of miRNAs in molding placental robustness, which must constantly adapt to altered maternal physiological status in order to sustain optimal support to the developing embryo. In this review we summarize the current information about placental miRNAs expression, and the lingering challenges in this field. PMID:21425434

  20. Mosaic retroposon insertion patterns in placental mammals.

    PubMed

    Churakov, Gennady; Kriegs, Jan Ole; Baertsch, Robert; Zemann, Anja; Brosius, Jürgen; Schmitz, Jürgen

    2009-05-01

    One and a half centuries after Charles Darwin and Alfred Russel Wallace outlined our current understanding of evolution, a new scientific era is dawning that enables direct observations of genetic variation. However, pure sequence-based molecular attempts to resolve the basal origin of placental mammals have so far resulted only in apparently conflicting hypotheses. By contrast, in the mammalian genomes where they were highly active, the insertion of retroelements and their comparative insertion patterns constitute a neutral, virtually homoplasy-free archive of evolutionary histories. The "presence" of a retroelement at an orthologous genomic position in two species indicates their common ancestry in contrast to its "absence" in more distant species. To resolve the placental origin controversy we extracted approximately 2 million potentially phylogenetically informative, retroposon-containing loci from representatives of the major placental mammalian lineages and found highly significant evidence challenging all current single hypotheses of their basal origin. The Exafroplacentalia hypothesis (Afrotheria as the sister group to all remaining placentals) is significantly supported by five retroposon insertions, the Epitheria hypothesis (Xenarthra as the sister group to all remaining placentals) by nine insertion patterns, and the Atlantogenata hypothesis (a monophyletic clade comprising Xenarthra and Afrotheria as the sister group to Boreotheria comprising all remaining placentals) by eight insertion patterns. These findings provide significant support for a "soft" polytomy of the major mammalian clades. Ancestral successive hybridization events and/or incomplete lineage sorting associated with short speciation intervals are viable explanations for the mosaic retroposon insertion patterns of recent placental mammals and for the futile search for a clear root dichotomy.

  1. Impaired placentation in fetal alcohol syndrome.

    PubMed

    Gundogan, F; Elwood, G; Longato, L; Tong, M; Feijoo, A; Carlson, R I; Wands, J R; de la Monte, S M

    2008-02-01

    Intrauterine growth restriction (IUGR) is one of the key features of fetal alcohol syndrome (FAS), and IUGR can be mediated by impaired placentation. Insulin-like growth factors (IGF) regulate placentation due to stimulatory effects on extravillous trophoblasts, which are highly motile and invasive. Previous studies demonstrated that extravillous trophoblasts express high levels of aspartyl-(asparaginyl) beta-hydroxylase (AAH), a gene that is regulated by IGF and has a critical role in cell motility and invasion. The present study examines the hypothesis that ethanol impaired placentation is associated with inhibition of AAH expression in trophoblasts. Pregnant Long Evans rats were fed isocaloric liquid diets containing 0% or 37% ethanol by caloric content. Placentas harvested on gestation day 16 were used for histopathological, mRNA, and protein studies to examine AAH expression in relation to the integrity of placentation and ethanol exposure. Chronic ethanol feeding prevented or impaired the physiological conversion of uterine vessels required for expansion of maternal circulation into placenta, a crucial process for adequate placentation. Real-time quantitative RT-PCR analysis demonstrated significant reductions in IRS-1, IRS-2, and significant increases in IGF-II and IGF-II receptor mRNA levels in ethanol-exposed placentas. These abnormalities were associated with significantly reduced levels of AAH expression in trophoblastic cells, particularly within the mesometrial triangle (deep placental bed) as demonstrated by real time quantitative RT-PCR, Western blot analysis, ELISA, and immunohistochemical staining. Ethanol-impaired placentation is associated with inhibition of AAH expression in trophoblasts. This effect of chronic gestational exposure to ethanol may contribute to IUGR in FAS.

  2. Aromatase expression is linked to estrogenic sensitivity of periurethral muscles in female rabbits.

    PubMed

    de los Ángeles Carrasco-Ruiz, María; García-Villamar, Verónica; López-García, Kenia; Sánchez-García, Octavio; Pacheco, Pablo; Cuevas, Estela; Martínez-Gómez, Margarita; Castelán, Francisco

    2015-06-01

    Beyond its role in the conversion of androgens to estrogens, the expression of aromatase could influence on the estrogenic signalling in targeted tissues. Considering the well-defined biochemical and physiological differences between the pubococcygeus (Pcm) and bulbospongiosus (Bsm) muscles in female rabbits, it is presently hypothesized that the aromatase expression is differentially linked to the estrogen sensitivity of each muscle. To this end, serum estradiol levels and the aromatase expression, presence of ERα and ERβ and morphometry were evaluated in the Pcm and Bsm of female rabbits allocated in control, ovariectomized (OVX) and OVX treated with estradiol benzoate (OVX + EB) groups. Aromatase expression was high in the Pcm. Independently to serum estradiol, ovariectomy increased aromatase expression in the Pcm while decreased it in the Bsm. The EB treatment avoided the effect of ovariectomy only in the Pcm. The number of immunoreactive nuclei anti-ERα and anti-ERβ was high in the Pcm of OVX and OVX + EB rabbits, while those in the Bsm remained unchanged. The number of peripheral nuclei per fibre and the cross-sectional area-to-myonucleus ratio were modified only in the Pcm. Our findings support aromatase expression in the Pcm, and Bsm of rabbits is differentially linked to estrogenic sensitivity of each muscle.

  3. Quantitative Analysis of Long-Form Aromatase mRNA in the Male and Female Rat Brain

    PubMed Central

    Tabatadze, Nino; Sato, Satoru M.; Woolley, Catherine S.

    2014-01-01

    In vitro studies show that estrogens acutely modulate synaptic function in both sexes. These acute effects may be mediated in vivo by estrogens synthesized within the brain, which could fluctuate more rapidly than circulating estrogens. For this to be the case, brain regions that respond acutely to estrogens should be capable of synthesizing them. To investigate this question, we used quantitative real-time PCR to measure expression of mRNA for the estrogen-synthesizing enzyme, aromatase, in different brain regions of male and female rats. Importantly, because brain aromatase exists in two forms, a long form with aromatase activity and a short form with unknown function, we targeted a sequence found exclusively in long-form aromatase. With this approach, we found highest expression of aromatase mRNA in the amygdala followed closely by the bed nucleus of the stria terminalis (BNST) and preoptic area (POA); we found moderate levels of aromatase mRNA in the dorsal hippocampus and cingulate cortex; and aromatase mRNA was detectable in brainstem and cerebellum, but levels were very low. In the amygdala, gonadal/hormonal status regulated aromatase expression in both sexes; in the BNST and POA, castration of males down-regulated aromatase, whereas there was no effect of estradiol in ovariectomized females. In the dorsal hippocampus and cingulate cortex, there were no differences in aromatase levels between males and females or effects of gonadal/hormonal status. These findings demonstrate that long-form aromatase is expressed in brain regions that respond acutely to estrogens, such as the dorsal hippocampus, and that gonadal/hormonal regulation of aromatase differs among different brain regions. PMID:25036039

  4. [Placental developmental defects in cloned mammalian animals].

    PubMed

    Ao, Zheng; Liu, Dewu; Cai, Gengyuan; Wu, Zhenfang; Li, Zicong

    2016-05-01

    The cloning technique, also called somatic cell nuclear transfer (SCNT), has been successfully established and gradually applied to various mammalian species. However, the developmental rate of SCNT mammalian embryos is very low, usually at 1% to 5%, which limits the application of SCNT. Placental developmental defects are considered as the main cause of SCNT embryo development inhibition. Almost all of SCNT-derived mammalian placentas exhibit various abnormalities, such as placental hyperplasia, vascular defects and umbilical cord malformation. Mechanistically, these abnormalities result from failure of establishment of correct epigenetic modification in the trophectoderm genome, which leads to erroneous expression of important genes for placenta development-related, particularly imprinted genes. Consequently, aberrant imprinted gene expression gives rise to placental morphologic abnormalities and functional defects, therefore decreases developmental competence of cloned embryos. Currently, although numerous methods that can improve the developmental ability of SCNT-derived embryos have been reported, most of them are unable to substantially enhance the success rate of SCNT due to failure to eliminate the placental development defects. In this review, we summarize placental abnormalities and imprinted gene expression in mammalian cloning, and propose directions for the future research aiming to improve the cloning efficiency. PMID:27232488

  5. 21 CFR 862.1585 - Human placental lactogen test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... placental lactogen are used in the diagnosis and clinical management of high-risk pregnancies involving fetal distress associated with placental insufficiency. Measurements of HPL are also used in...

  6. The individual or combinational effects of Hesperetin and Letrozole on the activity and expression of aromatase in MCF-7 cells.

    PubMed

    Rahideh, S T; Shidfar, F; Nourbakhsh, M; Hoseini, M; Koohdani, F; Entezam, M; Keramatipour, M

    2016-05-30

    Aromatase catalyzes the last and rate-limiting step in estrogen biosynthesis. Inhibition of estrogen production is a common strategy for breast cancer treatment. Citrus flavonoids have been confirmed to exhibit efficacious biological activities, particularly in cancer therapy. This study was carried out to investigate the effect of hesperetin on the activity and expression of aromatase and compare this property with letrozole as an aromatase inhibitor in MCF-7 breast cancer cell line. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assays in this study demonstrated that hesperetin at a concentration of 200 μM decreased cell viability in a time dependent manner (P<0.05). Aromatase activity assay, based on 17β-Estradiol (E2) production from testosterone, revealed that hesperetin had no effect. Real-time PCR results indicated that treatment with 1μM concentration of hesperetin for 48 h significantly decreased relative aromatase expression (P =0.004). Combination of letrozole and hesperetin also had no effect on aromatase. The changes in activity paralleled the expression of aromatase. Likely, the reduction in aromatase activity was delayed in time along with the reduction in expression ratio; however additional studies are needed to confirm this. In conclusion, the present study showed that hesperetin could decrease expression of aromatase at low concentrations in MCF-7 breast cancer cells.

  7. Induced synthesis of P450 aromatase and 17β-estradiol by D-aspartate in frog brain.

    PubMed

    Burrone, Lavinia; Santillo, Alessandra; Pinelli, Claudia; Baccari, Gabriella Chieffi; Di Fiore, Maria Maddalena

    2012-10-15

    D-Aspartic acid is an endogenous amino acid occurring in the endocrine glands as well as in the nervous system of various animal phyla. Our previous studies have provided evidence that D-aspartate plays a role in the induction of estradiol synthesis in gonads. Recently, we have also demonstrated that D-aspartic acid induces P450 aromatase mRNA expression in the frog (Pelophylax esculentus) testis. P450 aromatase is the key enzyme in the estrogen synthetic pathway and irreversibly converts testosterone into 17β-estradiol. In this study, we firstly investigated the immunolocalisation of P450 aromatase in the brain of P. esculentus, which has never previously been described in amphibians. Therefore, to test the hypothesis that d-aspartate mediates a local synthesis of P450 aromatase in the frog brain, we administered D-aspartate in vivo to male frogs and then assessed brain aromatase expression, sex hormone levels and sex hormone receptor expression. We found that D-aspartate enhances brain aromatase expression (mRNA and protein) through the CREB pathway. Then, P450 aromatase induces 17β-estradiol production from testosterone, with a consequent increase of its receptor. Therefore, the regulation of d-aspartate-mediated P450 aromatase expression could be an important step in the control of neuroendocrine regulation of the reproductive axis. Accordingly, we found that the sites of P450 aromatase immunoreactivity in the frog brain correspond to the areas known to be involved in neurosteroid synthesis. PMID:22771744

  8. Placental genetic variations in circadian clock-related genes increase the risk of placental abruption

    PubMed Central

    Qiu, Chunfang; Gelaye, Bizu; Denis, Marie; Tadesse, Mahlet G; Enquobahrie, Daniel A; Ananth, Cande V; Pacora, Percy N; Salazar, Manuel; Sanchez, Sixto E; Williams, Michelle A

    2016-01-01

    The genetic architecture of placental abruption (PA) remains poorly understood. We examined variations in SNPs of circadian clock-related genes in placenta with PA risk. We also explored placental and maternal genomic contributions to PA risk. Placental genomic DNA samples were isolated from 280 PA cases and 244 controls. Genotyping was performed using the Illumina Cardio-MetaboChip. We examined 116 SNPs in 13 genes known to moderate circadian rhythms. Logistic regression models were fit to estimate odds ratios (ORs). The combined effect of multiple SNPs on PA risk was estimated using a weighted genetic risk score. We examined independent and joint associations of wGRS derived from placental and maternal genomes with PA. Seven SNPs in five genes (ARNTL2, CRY2, DEC1, PER3 and RORA), in the placental genome, were associated with PA risk. Each copy of the minor allele (G) of a SNP in the RORA gene (rs2899663) was associated with a 30% reduced odds of PA (95% CI 0.52-0.95). The odds of PA increased with increasing placental-wGRS (Ptrend<0.001). The ORs were 1.00, 2.16, 3.24 and 4.48 across quartiles. Associations persisted after the maternal-wGRS was included in the model. There was evidence of an additive contribution of placental and maternal genetic contributions to PA risk. Participants with placental- and maternal-wGRS in the highest quartile, compared with those in the lowest quartile, had a 15.57-fold (95% CI 3.34-72.60) increased odds of PA. Placental variants in circadian clock-related genes are associated with PA risk; and the association persists after control of genetic variants in the maternal genome. PMID:27186326

  9. Zika Virus Infects Human Placental Macrophages.

    PubMed

    Quicke, Kendra M; Bowen, James R; Johnson, Erica L; McDonald, Circe E; Ma, Huailiang; O'Neal, Justin T; Rajakumar, Augustine; Wrammert, Jens; Rimawi, Bassam H; Pulendran, Bali; Schinazi, Raymond F; Chakraborty, Rana; Suthar, Mehul S

    2016-07-13

    The recent Zika virus (ZIKV) outbreak in Brazil has been directly linked to increased cases of microcephaly in newborns. Current evidence indicates that ZIKV is transmitted vertically from mother to fetus. However, the mechanism of intrauterine transmission and the cell types involved remain unknown. We demonstrate that the contemporary ZIKV strain PRVABC59 (PR 2015) infects and replicates in primary human placental macrophages, called Hofbauer cells, and to a lesser extent in cytotrophoblasts, isolated from villous tissue of full-term placentae. Viral replication coincides with induction of type I interferon (IFN), pro-inflammatory cytokines, and antiviral gene expression, but with minimal cell death. Our results suggest a mechanism for intrauterine transmission in which ZIKV gains access to the fetal compartment by directly infecting placental cells and disrupting the placental barrier. PMID:27247001

  10. Zika Virus Infects Human Placental Macrophages.

    PubMed

    Quicke, Kendra M; Bowen, James R; Johnson, Erica L; McDonald, Circe E; Ma, Huailiang; O'Neal, Justin T; Rajakumar, Augustine; Wrammert, Jens; Rimawi, Bassam H; Pulendran, Bali; Schinazi, Raymond F; Chakraborty, Rana; Suthar, Mehul S

    2016-07-13

    The recent Zika virus (ZIKV) outbreak in Brazil has been directly linked to increased cases of microcephaly in newborns. Current evidence indicates that ZIKV is transmitted vertically from mother to fetus. However, the mechanism of intrauterine transmission and the cell types involved remain unknown. We demonstrate that the contemporary ZIKV strain PRVABC59 (PR 2015) infects and replicates in primary human placental macrophages, called Hofbauer cells, and to a lesser extent in cytotrophoblasts, isolated from villous tissue of full-term placentae. Viral replication coincides with induction of type I interferon (IFN), pro-inflammatory cytokines, and antiviral gene expression, but with minimal cell death. Our results suggest a mechanism for intrauterine transmission in which ZIKV gains access to the fetal compartment by directly infecting placental cells and disrupting the placental barrier.

  11. Hans Strahl's pioneering studies in comparative placentation.

    PubMed

    Carter, A M; Mess, A

    2010-10-01

    Hans Strahl, a contemporary of Duval and Hubrecht, made many important contributions to comparative placentation. Despite this he is not well known and some of his original observations tend to be attributed to later authors. Strahl published a classification of placental types based on their shape and relationship to maternal tissues. This greatly influenced the work of Otto Grosser, who became better known in part because his work was more accessible to other scientists and clinicians. Strahl described the development of the fetal membranes across a broad range of mammalian orders extending his observations beyond parturition to the post partum involution of the uterus. He paid close attention to structures designed for histotrophic nutrition including the areolae of moles, haemophagous organs of carnivores and tenrecs and chorionic vesicles of lemurs and lorises. We here provide a summary of some of the most important findings made by Strahl including work on placentation in carnivores and higher primates that remains unsurpassed.

  12. 21 CFR 862.1585 - Human placental lactogen test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Human placental lactogen test system. 862.1585 Section 862.1585 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Systems § 862.1585 Human placental lactogen test system. (a) Identification. A human placental...

  13. 21 CFR 862.1585 - Human placental lactogen test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Human placental lactogen test system. 862.1585 Section 862.1585 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Systems § 862.1585 Human placental lactogen test system. (a) Identification. A human placental...

  14. Obesity is associated with inflammation and elevated aromatase expression in the mouse mammary gland

    PubMed Central

    Subbaramaiah, Kotha; Howe, Louise R.; Bhardwaj, Priya; Du, Baoheng; Gravaghi, Claudia; Yantiss, Rhonda K.; Zhou, Xi Kathy; Blaho, Victoria A.; Hla, Timothy; Yang, Peiying; Kopelovich, Levy; Hudis, Clifford A.; Dannenberg, Andrew J.

    2011-01-01

    Elevated circulating estrogen levels are associated with increased risk of breast cancer in obese postmenopausal women. Following menopause, the biosynthesis of estrogens through CYP19 (aromatase)-mediated metabolism of androgen precursors occurs primarily in adipose tissue, and the resulting estrogens are then secreted into the systemic circulation. The potential links between obesity, inflammation and aromatase expression are unknown. In both dietary and genetic models of obesity, we observed necrotic adipocytes surrounded by macrophages forming crown-like structures (CLS) in the mammary glands and visceral fat. The presence of CLS was associated with activation of NF-κB and increased levels of pro-inflammatory mediators (TNF-α, IL-1β, Cox-2), which were paralleled by elevated levels of aromatase expression and activity in the mammary gland and visceral fat of obese mice. Analyses of the stromal-vascular and adipose fractions of the mammary gland suggested that macrophage-derived pro-inflammatory mediators induced aromatase and estrogen-dependent gene expression (PR, pS2) in adipocytes. Saturated fatty acids, which have been linked to obesity-related inflammation, stimulated NF-κB activity in macrophages leading to increased levels of TNF-α, IL-1β and Cox-2, each of which contributed to the induction of aromatase in preadipocytes. The discovery of the obesity→inflammation→aromatase axis in the mammary gland and visceral fat and its association with CLS, may provide insight into mechanisms underlying the increased risk of hormone receptor-positive breast cancer in obese postmenopausal women, the reduced efficacy of aromatase inhibitors in the treatment of breast cancer in these women, and their generally worse outcomes. The presence of CLS may be a biomarker of increased breast cancer risk or poor prognosis. PMID:21372033

  15. P450-aromatase activity and expression in human testicular tissues with severe spermatogenic failure.

    PubMed

    Lardone, M C; Castillo, P; Valdevenito, R; Ebensperger, M; Ronco, A M; Pommer, R; Piottante, A; Castro, A

    2010-08-01

    There is evidence that impaired spermatogenesis is associated with an imbalance in the oestradiol/testosterone ratio and with Leydig cell (LC) dysfunction. In testis, P450-aromatase, encoded by CYP19, is responsible for the conversion of testosterone to oestradiol. The aims of this study were to quantify CYP19 mRNA expression, aromatase activity and protein localization, and to measure the oestradiol to testosterone ratio in testicular tissues of men with spermatogenic impairment. Twenty-four men with complete Sertoli cell-only syndrome (SCOS), 14 with focal SCOS, 14 with maturation arrest (MA), 8 with mixed atrophy and 30 controls with normal spermatogenesis were subjected to testicular biopsy. All subjects underwent a physical examination, cytogenetic and serum hormonal studies. Testicular CYP19 mRNA was quantified using real time RT-PCR. Testicular aromatase activity was measured using the (3)H(2)0 assay and protein expression was evaluated using immunohistochemistry. In cases, serum testosterone and oestradiol were normal, but the testosterone/LH ratio was lower compared with controls (p < 0.05). Aromatase was localized in the Leydig, Sertoli and germ cells of all tissues, although stronger intensity was observed in LC. Aromatase mRNA and activity were not altered in cases and correlated positively with LC number (r = 0.516 and r = 0.369; p < 0.008). The intratesticular oestradiol/testosterone ratio was elevated (p = 0.005) in complete SCOS patients compared with controls. In conclusion, testicular aromatase seems to be normal in most subjects with impaired spermatogenesis. However, an altered intratesticular oestradiol/testosterone ratio in some patients with complete SCOS suggests that aromatase is increased, which might contribute to Leydig cell dysfunction.

  16. Identification of aromatase activity in rodent pituitary cell strains.

    PubMed

    Callard, G V; Petro, Z; Tashjian, A H

    1983-07-01

    To date, biochemical evidence has been presented for hypophysial aromatization in only one species, a teleost fish, although the pituitary glands of several mammals have been reported to be aromatase negative. To reinvestigate this problem, established clonal strains of rodent pituitary cells (GH3, GH4C1, and AtT20/D16) were incubated at 37 C for 6-48 h in serum-less medium containing [7-3H]androstenedione. Radiolabeled metabolites were isolated by solvent extraction, thin layer chromatography, and phenolic partition. The authenticity of the estrogenic products in both cells and incubation medium was verified by methylation and recrystallization to constant specific activity. Measurement of androgen metabolites was also validated by recrystallization of selected samples. Authentic estrone and 17 beta-estradiol were identified in cultures of the two PRL- and GH-secreting clones, and there were strain differences in the quantity of estrogen produced (GH3 greater than GH4C1). Under the same conditions, aromatization was not detectable in the ACTH-secreting line (AtT20/D16). A time-yield analysis of androgen metabolism in GH4C1 cells showed that aromatization was linear for 12 h after labeling, but that substrate was diverted mainly to 5 alpha-reducing pathways. Large amounts of highly polar metabolites accumulated 24 and 48 h after the addition of [3H]androgen, and subsequent hydrolysis revealed that these were sulfo- and glucuronoconjugates. The metabolic fate of estrogen in GH4C1 cultures was investigated indirectly by adding a radioinert estrone trap together with the radiolabeled androgen substrate and was also tested in separate cultures by adding [3H]estrone and [3H]estradiol directly. Although the two estrogens were interconverted, there was no evidence that formed or added estrogen was extensively metabolized or conjugated. We conclude that the expression of aromatase activity in hypophysial cells is not a property of all transformed lines but may be dictated

  17. Identification of aromatase activity in rodent pituitary cell strains.

    PubMed

    Callard, G V; Petro, Z; Tashjian, A H

    1983-07-01

    To date, biochemical evidence has been presented for hypophysial aromatization in only one species, a teleost fish, although the pituitary glands of several mammals have been reported to be aromatase negative. To reinvestigate this problem, established clonal strains of rodent pituitary cells (GH3, GH4C1, and AtT20/D16) were incubated at 37 C for 6-48 h in serum-less medium containing [7-3H]androstenedione. Radiolabeled metabolites were isolated by solvent extraction, thin layer chromatography, and phenolic partition. The authenticity of the estrogenic products in both cells and incubation medium was verified by methylation and recrystallization to constant specific activity. Measurement of androgen metabolites was also validated by recrystallization of selected samples. Authentic estrone and 17 beta-estradiol were identified in cultures of the two PRL- and GH-secreting clones, and there were strain differences in the quantity of estrogen produced (GH3 greater than GH4C1). Under the same conditions, aromatization was not detectable in the ACTH-secreting line (AtT20/D16). A time-yield analysis of androgen metabolism in GH4C1 cells showed that aromatization was linear for 12 h after labeling, but that substrate was diverted mainly to 5 alpha-reducing pathways. Large amounts of highly polar metabolites accumulated 24 and 48 h after the addition of [3H]androgen, and subsequent hydrolysis revealed that these were sulfo- and glucuronoconjugates. The metabolic fate of estrogen in GH4C1 cultures was investigated indirectly by adding a radioinert estrone trap together with the radiolabeled androgen substrate and was also tested in separate cultures by adding [3H]estrone and [3H]estradiol directly. Although the two estrogens were interconverted, there was no evidence that formed or added estrogen was extensively metabolized or conjugated. We conclude that the expression of aromatase activity in hypophysial cells is not a property of all transformed lines but may be dictated

  18. Ocular Surface Disease in Breast Cancer Patients Using Aromatase Inhibitors.

    PubMed

    Chatziralli, Irini; Sergentanis, Theodoros; Zagouri, Flora; Chrysikos, Dimosthenis; Ladas, Ioannis; Zografos, George C; Moschos, Marilita

    2016-09-01

    Aromatase inhibitors (AIs) are widely used as adjuvant hormonal therapy in postmenopausal women with hormone receptor-positive breast cancer. The purpose of this study was to investigate the potential impact of AIs on the anterior segment of the eye and especially the ocular surface. Participants in our study were 41 hormone receptor-positive early stage breast cancer patients (80 eyes), treated with AIs, while 80 eyes of 40 age- and gender-matched healthy controls, not previously used AIs for any purpose, were also evaluated. All participants underwent a complete ophthalmological examination, including best corrected visual acuity (BCVA) assessment, slit-lamp biomicroscopy, and dilated fundus examination. Ocular surface disease-related symptoms and signs were also recorded. The most common symptom was found to be blurred vision, while other symptoms included foreign body sensation, tearing, redness, and photophobia. Slit-lamp examination revealed blepharitis and meibomian gland dysfunction in 75% and 42.5% of patients, respectively. Superficial punctate keratitis and conjunctival injection were also present. Our results demonstrated a high prevalence of ocular surface disease-related symptoms and signs in patients receiving AIs compared to healthy controls. This study may raise a flag regarding the use of AIs. However, further and larger prospective longitudinal studies are needed to examine the possible effect of AIs alone or in combination with chemotherapy in the eyes of breast cancer patients.

  19. Ocular Surface Disease in Breast Cancer Patients Using Aromatase Inhibitors.

    PubMed

    Chatziralli, Irini; Sergentanis, Theodoros; Zagouri, Flora; Chrysikos, Dimosthenis; Ladas, Ioannis; Zografos, George C; Moschos, Marilita

    2016-09-01

    Aromatase inhibitors (AIs) are widely used as adjuvant hormonal therapy in postmenopausal women with hormone receptor-positive breast cancer. The purpose of this study was to investigate the potential impact of AIs on the anterior segment of the eye and especially the ocular surface. Participants in our study were 41 hormone receptor-positive early stage breast cancer patients (80 eyes), treated with AIs, while 80 eyes of 40 age- and gender-matched healthy controls, not previously used AIs for any purpose, were also evaluated. All participants underwent a complete ophthalmological examination, including best corrected visual acuity (BCVA) assessment, slit-lamp biomicroscopy, and dilated fundus examination. Ocular surface disease-related symptoms and signs were also recorded. The most common symptom was found to be blurred vision, while other symptoms included foreign body sensation, tearing, redness, and photophobia. Slit-lamp examination revealed blepharitis and meibomian gland dysfunction in 75% and 42.5% of patients, respectively. Superficial punctate keratitis and conjunctival injection were also present. Our results demonstrated a high prevalence of ocular surface disease-related symptoms and signs in patients receiving AIs compared to healthy controls. This study may raise a flag regarding the use of AIs. However, further and larger prospective longitudinal studies are needed to examine the possible effect of AIs alone or in combination with chemotherapy in the eyes of breast cancer patients. PMID:27296769

  20. Investigation of aromatase inhibitory activity of metal complexes of 8-hydroxyquinoline and uracil derivatives

    PubMed Central

    Prachayasittikul, Veda; Pingaew, Ratchanok; Nantasenamat, Chanin; Prachayasittikul, Supaluk; Ruchirawat, Somsak; Prachayasittikul, Virapong

    2014-01-01

    Purpose Estrogens play important roles in the pathogenesis and progression of breast cancer as well as estrogen-related diseases. Aromatase is a key enzyme in the rate-limiting step of estrogen production, in which its inhibition is one strategy for controlling estrogen levels to improve prognosis of estrogen-related cancers and diseases. Herein, a series of metal (Mn, Cu, and Ni) complexes of 8-hydroxyquinoline (8HQ) and uracil derivatives (4–9) were investigated for their aromatase inhibitory and cytotoxic activities. Methods The aromatase inhibition assay was performed according to a Gentest™ kit using CYP19 enzyme, wherein ketoconazole and letrozole were used as reference drugs. The cytotoxicity was tested on normal embryonic lung cells (MRC-5) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results Only Cu complexes (6 and 9) exhibited aromatase inhibitory effect with IC50 0.30 and 1.7 μM, respectively. Cytotoxicity test against MRC-5 cells showed that Mn and Cu complexes (5 and 6), as well as free ligand 8HQ, exhibited activity with IC50 range 0.74–6.27 μM. Conclusion Cu complexes (6 and 9) were found to act as a novel class of aromatase inhibitor. Our findings suggest that these 8HQ–Cu–uracil complexes are promising agents that could be potentially developed as a selective anticancer agent for breast cancer and other estrogen-related diseases. PMID:25152615

  1. Immunoexpression of aromatase in immature and adult males of the European bison (Bison bonasus, Linnaeus 1758).

    PubMed

    Kopera, I; Szczepanowicz, M; Gizejewski, Z; Sadowska, J; Bilińska, B

    2010-04-01

    Based on recent literature dealing with the role of oestrogens in the male gonad, attempts were undertaken to reveal the site of aromatization within the testis of the European bison (Bison bonasus). Testes were collected from culled animals living in free-ranging populations in Bialowieza Forest, Poland (nine males aged 8 months to 10 years). Moreover, to check for any alterations in the expression of testicular aromatase between American bison (Bison bison) and European bison, testes from one adult 10-year-old individual were also chosen for this study. For immunohistochemistry, 4% formaldehyde fixative was used. Both qualitative and quantitative evaluations of immunohistochemical staining were performed. Leydig cells, Sertoli cells and germ cells exhibited a positive immunoreaction for aromatase in testes of immature and sexually mature bison. A marked increase in aromatase expression was observed in three adult European individuals with impaired spermatogenesis. Consistent with recent data and those of our own, it might be suggested that the strong expression of aromatase negatively affects spermatogenic function in bison testes and may serve as a possible explanation of specific sperm defects observed in European bison bulls. On the contrary, one cannot exclude that differences in the aromatase immunoexpression levels are attributed to the homozygosity, the cause of frequent disease in European bison.

  2. Placental Nutrient Transport and Intrauterine Growth Restriction

    PubMed Central

    Gaccioli, Francesca; Lager, Susanne

    2016-01-01

    Intrauterine growth restriction refers to the inability of the fetus to reach its genetically determined potential size. Fetal growth restriction affects approximately 5–15% of all pregnancies in the United States and Europe. In developing countries the occurrence varies widely between 10 and 55%, impacting about 30 million newborns per year. Besides having high perinatal mortality rates these infants are at greater risk for severe adverse outcomes, such as hypoxic ischemic encephalopathy and cerebral palsy. Moreover, reduced fetal growth has lifelong health consequences, including higher risks of developing metabolic and cardiovascular diseases in adulthood. Numerous reports indicate placental insufficiency as one of the underlying causes leading to altered fetal growth and impaired placental capacity of delivering nutrients to the fetus has been shown to contribute to the etiology of intrauterine growth restriction. Indeed, reduced expression and/or activity of placental nutrient transporters have been demonstrated in several conditions associated with an increased risk of delivering a small or growth restricted infant. This review focuses on human pregnancies and summarizes the changes in placental amino acid, fatty acid, and glucose transport reported in conditions associated with intrauterine growth restriction, such as maternal undernutrition, pre-eclampsia, young maternal age, high altitude and infection. PMID:26909042

  3. Preeclampsia, biomarkers, syncytiotrophoblast stress, and placental capacity.

    PubMed

    Redman, Christopher W G; Staff, Anne Cathrine

    2015-10-01

    The maternal syndrome of preeclampsia is mediated by dysfunctional syncytiotrophoblast (STB). When this is stressed by uteroplacental malperfusion, its signaling to the mother changes, as part of a highly coordinated stress response. The STB signals are both proinflammatory and dysangiogenic such that the preeclamptic mother has a stronger vascular inflammatory response than normal, with an antiangiogenic bias. Angiogenic factors have limitations as preeclampsia biomarkers, especially for prediction and diagnosis of preeclampsia at term. However, if they are recognized as markers of STB stress, their physiological changes at term demonstrate that STB stress develops in all pregnancies. The biomarkers reveal that the duration of pregnancies is restricted by placental capacity, such that there is increasing placental dysfunction, at and beyond term. This capacity includes limitations imposed by the size of the uterus, the capacity of the uteroplacental circulation and, possibly, the supply of villous progenitor trophoblast cells. Limited placental capacity explains the increasing risks of postmaturity, including preeclampsia. Early-onset preeclampsia is predictable because STB stress and changes in its biomarkers are intrinsic to poor placentation, an early pregnancy pathology. Prediction of preeclampsia at term is not good because there is no early STB pathology. Moreover, biomarkers cannot accurately diagnose term preeclampsia against a background of universal STB dysfunction, which may or may not be clinically revealed before spontaneous or induced delivery. In this sense, postterm pregnancy is, at best, a pseudonormal state. However, the markers may prove useful in screening for women with more severe problems of postmaturity.

  4. BROMODICHLOROMETHANE INHIBITS HUMAN PLACENTAL TROPHOBLAST DIFFERENTIATION

    EPA Science Inventory

    BROMODICHLOROMETHANE INHIBITS HUMAN PLACENTAL
    TROPHOBLAST DIFFERENTIATION
    Jiangang Chen, Twanda L. Thirkill, Peter N. Lohstroh, Susan R. Bielmeier, Michael
    G. Narotsky, Deborah S. Best, Randy A. Harrison, Kala Natarajan, Rex A. Pegram,
    Bill L. Lasley, and Gordon C. Do...

  5. Reduced placental volume and flow in severe growth restricted fetuses

    PubMed Central

    Abulé, Renata Montes Dourado; Bernardes, Lisandra Stein; Doro, Giovana Farina; Miyadahira, Seizo; Francisco, Rossana Pulcinelli Vieira

    2016-01-01

    OBJECTIVES: To evaluate placental volume and vascular indices in pregnancies with severe fetal growth restriction and determine their correlations to normal reference ranges and Doppler velocimetry results of uterine and umbilical arteries. METHODS: Twenty-seven fetuses with estimated weights below the 3rd percentile for gestational age were evaluated. Placental volume and vascular indices, including vascularization, flow, and vascularization flow indices, were measured by three-dimensional ultrasound using a rotational technique and compared to a previously described nomogram. The observed-to-expected placental volume ratio for gestational age and observed-to-expected placental volume ratio for fetal weight were calculated. Placental parameters correlated with the Doppler velocimetry results of uterine and umbilical arteries. RESULTS: The mean uterine artery pulsatility index was negatively correlated with the observed-to-expected placental volume ratio for gestational age, vascularization index and vascularization flow index. The observed-to-expected placental volume ratio for gestational age and observed-to-expected placental volume ratio for fetal weight and vascularization index were significantly lower in the group with a bilateral protodiastolic notch. No placental parameter correlated with the umbilical artery pulsatility index. CONCLUSIONS: Pregnancies complicated by severe fetal growth restriction are associated with reduced placental volume and vascularization. These findings are related to changes in uterine artery Doppler velocimetry. Future studies on managing severe fetal growth restriction should focus on combined results of placental three-dimensional ultrasound and Doppler studies of uterine arteries. PMID:27438567

  6. Aromatization of 15 alpha and 16 alpha hydroxylated androgens in the human placental using [1,2-3H]-substrates.

    PubMed

    Cantineau, R; Kremers, P; De Graeve, J; Gielen, J E; Lambotte, R

    1982-02-01

    This in vitro study reports data on the aromatization of [1,2-3H]-C19 steroids in the human term placenta [androstenedione (III), testosterone (IV), 15 alpha-hydroxy-androstenedione (V), 15 alpha-hydroxy-testosterone (VI), 16 alpha-hydroxy-androstenedione (VII)]. The hydroxylated androgens were microbiologically synthesized from commercially radiolabelled [1,2-3H]-androstenedione and testosterone. Androstenedione and testosterone were good substrates for the human placental aromatase (low Km values, high Vmax); they strongly inhibited the 15 and 16 hydroxylated androgens aromatizations. On the other hand, these hydroxylated compounds acted as poor substrates and were only non-competitive inhibitors of the androstenedione and testosterone aromatizations. However, 15 alpha-hydroxy-androstenedione could not be disregarded as a potential precursor of 15 alpha-hydroxylated estrogens in the human placenta. PMID:7078154

  7. REPRODUCTION AND AROMATASE ACTIVITY IN THE MARINE FISH CUNNER (TAUTOGOLABROUS ADSPERSUS) EXPOSED TO ATRAZINE AND OCTYLPHENOL IN THE LABORATORY

    EPA Science Inventory

    This study was conducted to test the hypothesis that reproduction in fish is altered by exposure to endocrine-disrupting chemicals (EDCs) that modify aromatase activity. Aromatase, a product of the CYP19 gene, is the enzyme that catalyzes the conversion of the androgens androst...

  8. Placental villous vascular endothelial growth factor expression and vascularization after estrogen suppression during the last two-thirds of baboon pregnancy

    PubMed Central

    Robb, Victoria A.; Pepe, Gerald J.; Albrecht, Eugene D.

    2009-01-01

    We have recently shown that placental cytotrophoblast vascular endothelial growth factor (VEGF) expression and vessel density were increased by elevating estrogen and decreased by suppressing estrogen in early baboon pregnancy. The present study determined whether the elevation in estrogen which occurs in the last two-thirds of baboon pregnancy also has a role in the regulation of placental villous VEGF expression and angiogenesis. Placentas were obtained on day 170 of gestation (term, 184 days) from baboons untreated or treated with the aromatase inhibitor CGS 20267 or CGS 20267 plus estradiol daily on days 30–169. Serum estradiol levels in CGS 20267-treated baboons were decreased (P < 0.001) by 95%, however, placental cytotrophoblast VEGF mRNA levels (means ± SE, attomoles/μg RNA) were similar in untreated (25,807 ± 5,873), CGS 20267-treated (23,900 ± 1,940) and CGS 20267 plus estradiol-treated (26,885 ± 2,569) baboons. VEGF mRNA levels in the syncytiotrophoblast (2,008 ± 405) and inner villous stromal cell (1,724 ± 287) fractions of untreated baboons also were not altered by CGS 20267. However, whole villous VEGF mRNA levels in CGS 20267-treated baboons (18,590 ± 2,315) were 4-fold greater (P < 0.001) than in untreated animals and restored to normal by estradiol. Percent vascularized area (15.88 ± 0.88%) and vessel density (1,375 ± 71/mm2) of the villous placenta in untreated animals were not altered by estrogen deprivation. We propose that villous cytotrophoblasts lose their responsivity to estrogen and that placental villous cytotrophoblast VEGF expression and angiogenesis are regulated by estrogen in a cell- and gestational age-specific manner, and that factors other than estrogen maintain VEGF expression in the last two-thirds of pregnancy. PMID:17906373

  9. Targeting Cytochrome P450 Enzymes: A New Approach in Anti-cancer Drug Development

    PubMed Central

    Bruno, Robert D.; Njar, Vincent C.O.

    2007-01-01

    Cytochrome P450s (CYPs) represent a large class of heme-containing enzymes that catalyze the metabolism of multitudes of substrates both endogenous and exogenous. Until recently, however, CYPs have been largely overlooked in cancer drug development, acknowledged only for their role in Phase I metabolism of chemotherapeutics. The first successful strategy targeting CYP enzymes in cancer therapy was the development of potent inhibitors of CYP19 (aromatase) for the treatment of breast cancer. Aromatase inhibitors ushered in a new era in hormone ablation therapy for estrogen dependent cancers, and have paved the way for similar strategies (i.e. inhibition of CYP17) that combat androgen dependent prostate cancer. Identification of CYPs involved in the inactivation of anti-cancer metabolites of Vitamin D3 and Vitamin A has triggered development of agents that target these enzymes as well. The discovery of the over-expression of exogenous metabolizing CYPs, such as CYP1B1, in cancer cells has roused interest in the development of inhibitors for chemoprevention and of prodrugs designed to be activated by CYPs only in cancer cells. Finally, the expression of CYPs within tumors has been utilized in the development of bioreductive molecules that are activated by CYPs only under hypoxic conditions. This review offers the first comprehensive analysis of strategies in drug development that either inhibit or exploit CYP enzymes for the treatment of cancer. PMID:17544277

  10. Placental toxicology: tobacco smoke, abused drugs, multiple chemical interactions, and placental function.

    PubMed

    Sastry, B V

    1991-01-01

    There are increasing numbers of reports on the tobacco smoking and ingestion of abused drugs (e.g. morphine, cocaine) by pregnant women and the effects of the substances on the developing fetus and newborn infant. The passage of drugs and chemicals from the mother to the fetus is influenced by the placental transport and metabolism of the substances. Further, these drugs and chemicals affect the nutrient transport systems in the placenta. The three major drugs of abuse-nicotine, morphine and cocaine-depress both active amino-acid uptake by human placental villi and transplacental amino-acid transport by reason of the drugs' influence on placental cholinergic and opiate systems. Part of this depression (10-16%) is not reversible. Nicotine blocks the cholinergic receptor and thus blocks acetylcholine (ACh)-facilitated amino-acid transport. Morphine stimulates opiate kappa receptors and depresses ACh release. Cocaine blocks Ca2+ influx and thus blocks ACh release. ACh causes dilation of blood vessels and maintains placental blood flow by the activation of endothelial muscarinic receptors. By interfering with ACh release and placental blood flow, the three drugs of abuse may depress the diffusion of amino acids and other nutrients from the trophoblast into the placental circulation. Three regulatory systems are delineated for amino-acid uptake by the placenta: placental ACh, phospholipid N-methyltransferase, and the gammaglutamyl cycle. These systems operate in concert with one another and are dependent on cellular formation of adenosine 5'-triphosphate (ATP). Placental hypoxia induced by carbon monoxide and other tobacco gases depresses the energy-dependent processes and thus the ATP levels of placental cells. Maternal tobacco smoking and drug abuse cause placental insufficiencies for amino-acid transport, which may partially explain the fetal intrauterine growth retardation caused by these substances. Part of the amino-acid deficits may be compensated for by the

  11. IBIS II: a breast cancer prevention trial in postmenopausal women using the aromatase inhibitor anastrozole.

    PubMed

    Cuzick, Jack

    2008-09-01

    Tamoxifen has been shown to reduce the incidence of estrogen receptor-positive breast cancer by approximately 50% in high-risk women. Similar results are seen for raloxifene, but it has a more favorable side-effect profile. Data on contralateral tumors from women in adjuvant trials treated with aromatase inhibitors suggest that new tumors can be reduced by another 50% with these drugs, suggesting a potential 75% reduction of estrogen receptor-positive tumors when used in a prophylactic manner. Side effects appear to be fewer with the aromatase inhibitors, with no excess of gynecologic (including endometrial cancer) or thromboembolic events, but an increase in fracture risk and joint symptoms does occur. IBIS II is a placebo-controlled prevention trial evaluating 5 years of the aromatase inhibitor anastrozole in high-risk postmenopausal women. The primary end point is breast cancer incidence, but major efforts are also being directed at minimizing any fracture risk.

  12. Can Exercise Ameliorate Aromatase Inhibitor-Induced Cognitive Decline in Breast Cancer Patients?

    PubMed

    Li, Cuicui; Zhou, Chenglin; Li, Rena

    2016-08-01

    Aromatase inhibitors (AIs) have been commonly used as an effective adjuvant therapy in treatment of breast cancer, especially for menopausal women with estrogen receptor-positive breast cancer. Due to the nature of aromatase, the key enzyme for endogenous estrogen synthesis, inhibitory of aromatase-induced side effects, such as cognitive impairment has been reported in both human and animal studies. While extensive evidence suggested that physical exercises can improve learning and memory activity and even prevent age-related cognitive decline, basic research revealed some common pathways between exercise and estrogen signaling that affected cognitive function. This review draws on clinical and basic studies to assess the potential impact of exercise in cognitive function from women treated with AIs for breast cancer and explore the potential mechanism and effects of exercise on estrogen-related cognition. PMID:26223800

  13. Aromatase Inhibitor-Induced Erythrocytosis in a Patient Undergoing Hormonal Treatment for Breast Cancer

    PubMed Central

    Yeruva, Sri Lakshmi Hyndavi; Ogbonna, Onyekachi Henry; Oneal, Patricia

    2015-01-01

    Aromatase inhibitors (AIs) are most commonly used for breast cancer patients with hormone receptor positive disease. Although the side effect profile of aromatase inhibitors is well known, including common side effects like arthralgia, bone pain, arthritis, hot flashes, and more serious problems like osteoporosis, we present a case of an uncommon side effect of these medications. We report the case of a postmenopausal woman on adjuvant hormonal therapy with anastrozole after completing definitive therapy for stage IIIB estrogen receptor-positive breast cancer, who was referred to hematology service for evaluation of persistent erythrocytosis. Primary and known secondary causes of polycythemia were ruled out. On further evaluation, we found that her erythrocytosis began after initiation of anastrozole and resolved after it was discontinued. We discuss the pathophysiology of aromatase inhibitor-induced erythrocytosis and reference of similar cases reported in the literature. PMID:26137331

  14. Cytochromes P450

    PubMed Central

    Bak, Søren; Beisson, Fred; Bishop, Gerard; Hamberger, Björn; Höfer, René; Paquette, Suzanne; Werck-Reichhart, Danièle

    2011-01-01

    There are 244 cytochrome P450 genes (and 28 pseudogenes) in the Arabidopsis genome. P450s thus form one of the largest gene families in plants. Contrary to what was initially thought, this family diversification results in very limited functional redundancy and seems to mirror the complexity of plant metabolism. P450s sometimes share less than 20% identity and catalyze extremely diverse reactions leading to the precursors of structural macromolecules such as lignin, cutin, suberin and sporopollenin, or are involved in biosynthesis or catabolism of all hormone and signaling molecules, of pigments, odorants, flavors, antioxidants, allelochemicals and defense compounds, and in the metabolism of xenobiotics. The mechanisms of gene duplication and diversification are getting better understood and together with co-expression data provide leads to functional characterization. PMID:22303269

  15. Effects of Aromatase Inhibition and Androgen Activity on Serotonin and Behavior in Male Macaques

    PubMed Central

    Bethea, Cynthia L.; Reddy, Arubala P.; Robertson, Nicola; Colemen, Kristine

    2014-01-01

    Aggression in humans and animals has been linked to androgens and serotonin function. To further our understanding of the effect of androgens on serotonin and aggression in male macaques, we sought to manipulate circulating androgens and the activity of aromatase; and to then determine behavior and the endogenous availability of serotonin. Male Japanese macaques (Macaca fuscata) were castrated for 5-7 months and then treated for 3 months with [1] placebo, [2] testosterone (T), [3] T+Dutasteride (5a reductase inhibitor; AvodartTM), [4] T+Letrozole (non-steroidal aromatase inhibitor; FemeraTM), [5] Flutamide+ATD (androgen antagonist plus steroidal aromatase inhibitor) or [6] dihydrotestosterone (DHT)+ATD (n=5/group). Behavioral observations were made during treatments. At the end of the treatment period, each animal was sedated with propofol and administered a bolus of fenfluramine (5 mg/kg). Fenfluramine causes the release of serotonin proportional to endogenous availability and in turn, serotonin stimulates the secretion of prolactin. Therefore, serum prolactin concentrations reflect endogenous serotonin. Fenfluramine significantly increased serotonin/prolactin in all groups (p <0.0001). Fenfluramine-induced serotonin/prolactin in the T-treated group was significantly higher than the other groups (p<0.0001). Castration partially reduced the serotonin/prolactin response; and Letrozole partially blocked the effect of T. Complete inhibition of aromatase with ATD, a non-competitve inhibitor, significantly and similarly reduced the fenfluramine-induced serotonin/prolactin response in the presence or absence of DHT. Neither aggressive behavior nor yawning (indicators of androgen activity) correlated with serotonin/prolactin, but posited aromatase activity correlated significantly with prolactin (p<0.0008; r2 =0.95). In summary, androgens induced aggressive behavior but they did not regulate serotonin. Altogether, the data suggest that aromatase activity supports

  16. Effects of aromatase inhibition and androgen activity on serotonin and behavior in male macaques.

    PubMed

    Bethea, Cynthia L; Reddy, Arubala P; Robertson, Nicola; Coleman, Kristine

    2013-06-01

    Aggression in humans and animals has been linked to androgens and serotonin function. To further our understanding of the effect of androgens on serotonin and aggression in male macaques, we sought to manipulate circulating androgens and the activity of aromatase; and to then determine behavior and the endogenous availability of serotonin. Male Japanese macaques (Macaca fuscata) were castrated for 5-7 months and then treated for 3 months with (a) placebo; (b) testosterone (T); (c) T + Dutasteride (5a reductase inhibitor; AvodartTM); (d) T + Letrozole (nonsteroidal aromatase inhibitor; FemeraTM); (e) Flutamide + ATD (androgen antagonist plus steroidal aromatase inhibitor); or (f) dihydrotestosterone (DHT) + ATD (n = 5/group). Behavioral observations were made during treatments. At the end of the treatment period, each animal was sedated with propofol and administered a bolus of fenfluramine (5 mg/kg). Fenfluramine causes the release of serotonin proportional to endogenous availability and in turn, serotonin stimulates the secretion of prolactin. Therefore, serum prolactin concentrations reflect endogenous serotonin. Fenfluramine significantly increased serotonin/prolactin in all groups (p < .0001). Fenfluramine-induced serotonin/prolactin in the T-treated group was significantly higher than the other groups (p < .0001). Castration partially reduced the serotonin/prolactin response and Letrozole partially blocked the effect of T. Complete inhibition of aromatase with ATD, a noncompetitive inhibitor, significantly and similarly reduced the fenfluramine-induced serotonin/prolactin response in the presence or absence of DHT. Neither aggressive behavior nor yawning (indicators of androgen activity) correlated with serotonin/prolactin, but posited aromatase activity correlated significantly with prolactin (p < .0008; r² = 0.95). In summary, androgens induced aggressive behavior but they did not regulate serotonin. Altogether, the data suggest that aromatase activity

  17. Telencephalic aromatase but not a song circuit in a sub-oscine passerine, the golden collared manakin (Manacus vitellinus).

    PubMed

    Saldanha, C J; Schultz, J D; London, S E; Schlinger, B A

    2000-06-01

    In oscine passerines, the telencephalon expresses high levels of the estrogen synthetic enzyme aromatase. In contrast, forebrain aromatase is limited to low levels at discrete limbic loci in non-passerines. The function of forebrain aromatase in oscines is unknown, however, estrogen-sensitive elements of the telencephalic song circuit (an oscine characteristic) may be influenced by local aromatization. Very few studies have investigated the neuroendocrine characteristics of sub-oscine passerines. Species of this passerine sub-order are taxonomically similar to oscines, but do not appear to learn how to sing as oscines, and show no evidence of a song circuit. The neural expression of aromatase in these birds is unknown. We asked whether the golden-collared manakin, a sub-oscine, (a) showed evidence of a song circuit, and (b) expressed aromatase in the telencephalon at high levels like the zebra finch (oscine passerine) or at low levels like the quail (non-passerine). Nissl stains and immunocytochemistry for microtubule associated proteins showed no evidence of a song circuit in manakins of either sex, whereas both techniques delineate all song nuclei in the zebra finch. However, biochemical and immunocytochemical measures reveal that in the manakin, several telencephalic loci, including the hippocampus, caudomedial neostriatum, nucleus taeniae, and the lateral neostriatum express aromatase. Assays run in parallel show low to undetectable levels of aromatase in the telencephalon of the quail (nonpasserine) and abundant levels in the zebra finch (oscine passerine), suggesting a dissociation between the presence of a song circuit and forebrain aromatase expression in this sub-oscine. These data suggest that forebrain aromatase may have evolved in sub-oscine songbirds before the evolution of a song circuit and singing behavior in oscines. Alternatively, forebrain aromatase may serve functions distinct from singing behavior. PMID:11025342

  18. Hsp90 and PKM2 Drive the Expression of Aromatase in Li-Fraumeni Syndrome Breast Adipose Stromal Cells.

    PubMed

    Subbaramaiah, Kotha; Brown, Kristy A; Zahid, Heba; Balmus, Gabriel; Weiss, Robert S; Herbert, Brittney-Shea; Dannenberg, Andrew J

    2016-07-29

    Li-Fraumeni syndrome (LFS) patients harbor germ line mutations in the TP53 gene and are at increased risk of hormone receptor-positive breast cancers. Recently, elevated levels of aromatase, the rate-limiting enzyme for estrogen biosynthesis, were found in the breast tissue of LFS patients. Although p53 down-regulates aromatase expression, the underlying mechanisms are incompletely understood. In the present study, we found that LFS stromal cells expressed higher levels of Hsp90 ATPase activity and aromatase compared with wild-type stromal cells. Inhibition of Hsp90 ATPase suppressed aromatase expression. Silencing Aha1 (activator of Hsp90 ATPase 1), a co-chaperone of Hsp90 required for its ATPase activity, led to both inhibition of Hsp90 ATPase activity and reduced aromatase expression. In comparison with wild-type stromal cells, increased levels of the Hsp90 client proteins, HIF-1α, and PKM2 were found in LFS stromal cells. A complex comprised of HIF-1α and PKM2 was recruited to the aromatase promoter II in LFS stromal cells. Silencing either HIF-1α or PKM2 suppressed aromatase expression in LFS stromal cells. CP-31398, a p53 rescue compound, suppressed levels of Aha1, Hsp90 ATPase activity, levels of PKM2 and HIF-1α, and aromatase expression in LFS stromal cells. Consistent with these in vitro findings, levels of Hsp90 ATPase activity, Aha1, HIF-1α, PKM2, and aromatase were increased in the mammary glands of p53 null versus wild-type mice. PKM2 and HIF-1α were shown to co-localize in the nucleus of stromal cells of LFS breast tissue. Taken together, our results show that the Aha1-Hsp90-PKM2/HIF-1α axis mediates the induction of aromatase in LFS. PMID:27467582

  19. Tamoxifen through GPER upregulates aromatase expression: a novel mechanism sustaining tamoxifen-resistant breast cancer cell growth.

    PubMed

    Catalano, Stefania; Giordano, Cinzia; Panza, Salvatore; Chemi, Francesca; Bonofiglio, Daniela; Lanzino, Marilena; Rizza, Pietro; Romeo, Francesco; Fuqua, Suzanne A W; Maggiolini, Marcello; Andò, Sebastiano; Barone, Ines

    2014-07-01

    Tamoxifen resistance is a major clinical challenge in breast cancer treatment. Aromatase inhibitors are effective in women who progressed or recurred on tamoxifen, suggesting a role of local estrogen production by aromatase in driving tamoxifen-resistant phenotype. However, the link between aromatase activity and tamoxifen resistance has not yet been reported. We investigated whether long-term tamoxifen exposure may affect aromatase activity and/or expression, which may then sustain tamoxifen-resistant breast cancer cell growth. We employed MCF-7 breast cancer cells, tamoxifen-resistant MCF-7 cells (MCF-7 TR1 and TR2), SKBR-3 breast cancer cells, cancer-associated fibroblasts (CAFs1 and CAFs2). We used tritiated-water release assay, realtime-RT-PCR, and immunoblotting analysis for evaluating aromatase activity and expression; anchorage-independent assays for growth; reporter-gene, electrophoretic-mobility-shift, and chromatin-immunoprecipitation assays for promoter activity studies. We demonstrated an increased aromatase activity and expression, which supports proliferation in tamoxifen-resistant breast cancer cells. This is mediated by the G-protein-coupled receptor GPR30/GPER, since knocking-down GPER expression or treatment with a GPER antagonist reversed the enhanced aromatase levels induced by long-term tamoxifen exposure. The molecular mechanism was investigated in ER-negative, GPER/aromatase-positive SKBR3 cells, in which tamoxifen acts as a GPER agonist. Tamoxifen treatment increased aromatase promoter activity through an enhanced recruitment of c-fos/c-jun complex to AP-1 responsive elements located within the promoter region. As tamoxifen via GPER induced aromatase expression also in CAFs, this pathway may be involved in promoting aggressive behavior of breast tumors in response to tamoxifen treatment. Blocking estrogen production and/or GPER signaling activation may represent a valid option to overcome tamoxifen-resistance in breast cancers.

  20. 5 alpha-reductase and aromatase inhibitory constituents from Brassica rapa L. pollen.

    PubMed

    Li, Yong-Hui; Yang, Yi-Fang; Li, Kun; Jin, Li-Li; Yang, Nian-Yun; Kong, De-Yun

    2009-04-01

    In the screening of biologically active constituents from Brassica rapa pollen, the supercritical CO(2) fluid extract (SFE-CO(2)) showed potent 5 alpha-reductase and aromatase inhibiting activity. The SFE-CO(2) extract was separated by various chromatographic methods to give two new phytosterol derivatives, 24-methylenecholesterol linolenate (1) and cycloeucalenol linolenate (2), as well as eight known compounds, 24-methylenecholesterol palmitate (3), cycloeucalenol (4), pollinastanol (5), 24-methylenecholesterol (6), linolenic acid (7), palmitic acid (8), monolinolein (9) and monopalmitin (10), compounds 7 and 9 showed potent 5 alpha-reductase inhibitory activity; compounds 1-6 and 10 showed potent aromatase inhibitory activity.

  1. Factors regulating the bovine, caprine, rat and human ovarian aromatase promoters in a bovine granulosa cell model.

    PubMed

    Sahmi, Fatiha; Nicola, Edmir S; Zamberlam, Gustavo O; Gonçalves, Paulo D B; Vanselow, Jens; Price, Christopher A

    2014-05-01

    The ovarian promoter of the primate and rodent genes encoding cytochrome P450 aromatase (CYP19A1) are robustly responsive to forskolin in luteinized cell models, whereas the ruminant ovarian promoter is minimally active. We explored this discrepancy by investigating the activity of the bovine ovarian promoter in two bovine granulosa cell models, luteinizing and non-luteinizing cells in vitro. In non-luteinizing cells, both FSH and IGF1 increased abundance of transcripts derived from the ovarian promoter. Comparison of the activity of promoters of several species in response to transcription factors (forskolin, NR5A2, FOXL2) in luteinizing cells demonstrated that a rat ovarian promoter-luciferase reporter was regulated mainly by forskolin (18-fold increase over basal expression) and addition of NR5A2 or FOXL2 had no further effect. Activity of a human promoter was significantly increased by NR5A2 plus forskolin (153-fold) compared with forskolin alone (71-fold over basal); addition of FOXL2 did not significantly increase promoter activity. Forskolin alone provoked minor activation of caprine and bovine promoter reporters (3-fold over basal), and addition of NR5A2 increased activity (7- to 11-fold). When forskolin, NR5A2 and FOXL2 treatments were combined, the activity of the caprine and bovine promoters increased to 20- and 34-fold, respectively. These data suggest that a major reason why CYP19A1 is not expressed in luteinized cells (and the corpus luteum) of ruminants may be the stimulatory effect of FOXL2, which does not appear to be the case in the human and rat. PMID:24556528

  2. Placental mesenchymal dysplasia: chronological observation of placental images during gestation and review of the literature.

    PubMed

    Ohira, Satoshi; Ookubo, Nao; Tanaka, Kyoko; Takatsu, Akiko; Kobara, Hisanori; Kikuchi, Norihiko; Ohya, Ayumi; Kanai, Makoto; Shiozawa, Tanri

    2013-01-01

    Placental mesenchymal dysplasia (PMD) is characterized by multiple hypoechoic vesicles which are similar to molar changes in the placenta; however, the process of such morphological changes of PMD during pregnancy has not been fully understood. We performed a review of all PMD cases published in English and identified 49 articles including 110 cases. With regard to the gestational age at which the multicystic pattern was seen, approximately 70% of cases were diagnosed at 13-20 weeks of gestation. Another characteristic feature of PMD is varicose dilation of fetal chorionic vessels. As many as 90% of cases were diagnosed as placenta with dilated fetal chorionic vessels in the third trimester. We also report a case of PMD which was found at 10 weeks of gestation according to ultrasonic molar patterns. Serial observations of the placenta using ultrasound and magnetic resonance imaging revealed that multicystic lesions became smaller after 23 weeks. In contrast, dilated placental vessels on the fetal side became apparent at 38 weeks. The present review highlights that placental vesicular lesions of PMD may precede dilation of fetal chorionic vessels during pregnancy. It also indicates the potential of a gradual reduction in size of PMD's placental vesicular lesions by serial study of placental images.

  3. Chronic Placental Inflammation in Twin Pregnancies

    PubMed Central

    Bang, Heejin; Bae, Go Eun; Park, Ha Young; Kim, Yeon Mee; Choi, Suk-Joo; Oh, Soo-young; Roh, Cheong-Rae; Kim, Jung-Sun

    2015-01-01

    Background: Chronic placental inflammation, such as villitis of unknown etiology (VUE) and chronic chorioamnionitis (CCA), is considered a placental manifestation of maternal anti-fetal rejection. The aim of this study is to investigate its frequency in twin pregnancies compared to singleton pregnancies. Methods: Three hundred twin placentas and 1,270 singleton placentas were consecutively collected at a tertiary medical center in Seoul, Republic of Korea from 2009 to 2012. Hematoxylin and eosin sections of tissue samples (full-thickness placental disc and chorioamniotic membranes) were reviewed. Results: Non-basal VUE was more frequent in twin placentas than in singleton placentas (6.0% vs 3.2%, p < .05). In preterm birth, CCA was found less frequently in twin placentas than in singleton placentas (9.6% vs 14.8%, p < .05), reaching its peak at an earlier gestational age in twin placentas (29–32 weeks) than in singleton placentas (33–36 weeks). CCA was more frequent in twin pregnancies with babies of a different sex than with those with the same sex (13.8% vs 6.9%, p=.052). Separate dichorionic diamniotic twin placentas were affected by chronic deciduitis more frequently than singleton placentas (16.9% vs 9.7%, p<.05). Conclusions: The higher frequency of non-basal VUE in twin placentas and of CCA in twin placentas with different fetal sex supports the hypothesis that the underlying pathophysiological mechanism is maternal anti-fetal rejection related to increased fetal antigens in twin pregnancies. The peak of CCA at an earlier gestational age in twin placentas than in singleton placentas suggests that CCA is influenced by placental maturation. PMID:26459409

  4. Placentation in mammals once grouped as insectivores.

    PubMed

    Carter, Anthony M; Enders, Allen C

    2010-01-01

    Interest in insectivoran grade mammals has been reawakened by taxonomic changes that place tenrecs and golden moles in a new order and separate hedgehogs from moles, shrews and solenodons. This survey of their placentation shows there is great variation even within families. As an example three subfamilies of tenrec have been examined. The interhemal region is cellular hemomonochorial in Echinops and Microgale but endotheliochorial in Micropotamogale. Golden moles, which are placed in the same order, have hemodichorial placentation. Many insectivores have complex arrangements for histotrophic nutrition involving columnar trophoblast cells. These range from areolae in moles through complexly folded hemophagous regions in tenrecs to the trophoblastic annulus in shrews. Of these placental characters, few offer support to current phylogenies. However, the case for placing hedgehogs and gymnures in a separate order (Erinaceomorpha) is bolstered by the presence of interstitial implantation, amniogenesis by cavitation, a hemochorial barrier and a prominent spongy zone; these features do not occur in shrews, moles or solenodons (Soricomorpha). Three insectivoran grade mammals deserve close attention as they have been selected for genome sequencing. One of these, the European hedgehog (Erinaceus europaeus), has not been studied with current methodology and renewed investigation of this or the closely related genus Atelerix should be a priority.

  5. Neuropeptides and neurotransmitters in human placental villi.

    PubMed

    Zhang, C L; Cheng, L R; Wang, H; Zhuang, L Z; Huang, W Q

    1991-01-01

    The human placenta contains many kinds of bioactive substances which are more or less similar to those from the hypothalamic-pituitary-gonadal axis. Most of the studies were carried out mainly with term placenta. The present study, therefore, was attempted to identify, quantify and characterize these substances in the human placenta at the early pregnancy. Using the RIA, immunohistochemistry, HPLC, tissue culture and intrauterine injection methods, we have found that: (1) many kinds of neuropeptides and neurotransmitters are present in the placental villi; (2) LH-RH, NT and SRIF positive immunoreactive granules are localized in the cytotrophoblast and those of beta-EP, 5-HT positive granules in the syncytiotrophoblast; (3) synthetic LH-RH and dynorphin (Dyn) stimulate the hCG secretion of the early placental villi in vitro, and (4) the antisera of LH-RH, NT, Dyn and NE antagonist-alpha-MPT significantly reduced the number of blastocyst implantations in the early pregnant rat. These results indicate that in the human placenta there possibly exists a self-regulation mechanism for the synthesis and secretion of placental hormones and neurotransmitters. Therefore, the human placenta can be regarded as a neuroendocrine organ.

  6. Notes on placentation in the Suina.

    PubMed

    Macdonald, A A; Bosma, A A

    1985-01-01

    We examined the gross and microscopic anatomy of placental tissues and umbilical cords from six species representing the three living families of the Suina. These species included, of the Suidae, the wart hog (Phacochoerus aethiopicus), the giant forest hog (Hylochoerus meinertzhageni), the domestic pig (Sus scrofa), and the banded pig of Malaysia (Sus scrofa vittatus); of the Tayassuidae, the white-lipped peccary (Tayassu pecari); of the Hippopotamidae, the hippopotamus (Hippopotamus amphibius) and the pigmy hippopotamus (Choeropsis liberiensis). All these species have a diffuse epitheliochorial placenta. The chorion is folded, and has on its surface rows of shallow ripples or villi, interrupted by round, oval or irregularly shaped areolae. Placental capillaries indent the epithelial layer covering the tops and sides of the interareolar villi, but not the columnar cell layer lying in the troughs between these villi or covering the areolae. Cuboidal cells cover the crests of the villi in the Suidae and Hippopotamidae, whereas in the Tayassuidae the epithelium is syncytial in appearance. The similarities in placental structure between the six species are more apparent than the differences. Suidae and Tayassuidae have smooth umbilical cords containing two arteries and one vein; those of the Hippopotamidae are pustule-encrusted and contain two arteries and two veins. PMID:3991477

  7. The cytochrome p450 homepage.

    PubMed

    Nelson, David R

    2009-10-01

    The Cytochrome P450 Homepage is a universal resource for nomenclature and sequence information on cytochrome P450 ( CYP ) genes. The site has been in continuous operation since February 1995. Currently, naming information for 11,512 CYPs are available on the web pages. The P450 sequences are manually curated by David Nelson, and the nomenclature system conforms to an evolutionary scheme such that members of CYP families and subfamilies share common ancestors. The organisation and content of the Homepage are described.

  8. The effect of anabolic-androgenic steroids on aromatase activity and androgen receptor binding in the rat preoptic area.

    PubMed

    Roselli, C E

    1998-05-11

    The level of aromatase in the preoptic area of rats is transcriptionally regulated through a specific androgen-receptor mediated mechanism and can be used as a measure of central androgenic effect. Therefore, several commonly abused anabolic-androgenic steroids (AAS) were tested for their ability to induce aromatase activity in the preoptic area of castrated rats. In addition, we determined the relative binding affinities of these compounds for the androgen receptor, as well as their ability to bind androgen receptor in vivo following subcutaneous injections. All of the AAS compounds tested significantly stimulated POA aromatase activity above castrate levels. The compounds that produced the greatest stimulation of aromatase activity were those that bound most avidly to the androgen receptor in vitro (i.e., testosterone, dihydrotestosterone and nandrolone). In contrast, the 17alpha-alkylated compounds that were tested (stanozolol, danazol, methandrostenolone) modestly stimulated aromatase and were weak competitors for the androgen receptor. The subcutaneous injection of AAS compounds increased the concentrations of occupied nuclear androgen receptors in the brain, but the magnitude of effect was not related to their potency for inducing aromatase or their relative binding affinity for the androgen receptor suggesting that androgen receptor occupancy in POA is not correlated with the action of androgen on aromatase. The present results help explain the behavioral effects of AAS compounds in rats. PMID:9593936

  9. The placental mammal ancestor and the post-K-Pg radiation of placentals.

    PubMed

    O'Leary, Maureen A; Bloch, Jonathan I; Flynn, John J; Gaudin, Timothy J; Giallombardo, Andres; Giannini, Norberto P; Goldberg, Suzann L; Kraatz, Brian P; Luo, Zhe-Xi; Meng, Jin; Ni, Xijun; Novacek, Michael J; Perini, Fernando A; Randall, Zachary S; Rougier, Guillermo W; Sargis, Eric J; Silcox, Mary T; Simmons, Nancy B; Spaulding, Michelle; Velazco, Paúl M; Weksler, Marcelo; Wible, John R; Cirranello, Andrea L

    2013-02-01

    To discover interordinal relationships of living and fossil placental mammals and the time of origin of placentals relative to the Cretaceous-Paleogene (K-Pg) boundary, we scored 4541 phenomic characters de novo for 86 fossil and living species. Combining these data with molecular sequences, we obtained a phylogenetic tree that, when calibrated with fossils, shows that crown clade Placentalia and placental orders originated after the K-Pg boundary. Many nodes discovered using molecular data are upheld, but phenomic signals overturn molecular signals to show Sundatheria (Dermoptera + Scandentia) as the sister taxon of Primates, a close link between Proboscidea (elephants) and Sirenia (sea cows), and the monophyly of echolocating Chiroptera (bats). Our tree suggests that Placentalia first split into Xenarthra and Epitheria; extinct New World species are the oldest members of Afrotheria.

  10. Placental Dysfunction and Fetal Programming: The Importance of Placental Size, Shape, Histopathology, and Molecular Composition

    PubMed Central

    Longtine, Mark S.; Nelson, D. Michael

    2013-01-01

    Normal function of the placenta is pivotal for optimal fetal growth and development. Fetal programming commonly is associated with placental dysfunction that predisposes to obstetric complications and .suboptimal fetal outcomes. We consider several clinical phenotypes for placental dysfunction that likely predispose to fetal programming. Some of these reflect abnormal development of the chorioallantoic placenta in size, shape, or histopathology. Others result when exogenous stressors in the maternal environment combine with maladaptation of the placental response to yield small placentas with limited reserve, as typical of early-onset intrauterine growth restriction and preeclampsia. Still others reflect epigenetic changes, including altered expression of imprinted genes, altered enzymatic activity, or altered efficiencies in nutrient transport. Although the human placenta is a transient organ that persists only 9 months, the effects of this organ on the offspring remain for a lifetime. PMID:21710395

  11. Topological Analysis of Placental Arteries:. Correlation with Neonatal Growth

    NASA Astrophysics Data System (ADS)

    Yamada, H.; Yakubo, K.

    2007-07-01

    The aim of study was to assess whether any network index of placental surface arteries was associated with neonatal birth weight. Twenty-six placentas were randomly selected between 34 and 41 weeks of gestational ages. Placental weights ranged 385 to 770 g; and neonatal weights ranged 1960 to 3680 g. After visualization of placental surface arteries by a milk injection method, network indices including the number of nodes, network density, network diameter, average distance of nodes, and the degree centralization were determined. These network indices and placental weights were compared with neonatal birth weights. The Number of nodes, network density, network diameter, average distance of nodes, and the degree centralization were found to be as follows (Mean ± SD); 84.7 ± 29.3, 0.0262 ± 0.0088, 15.8 ± 2.77, 7.83 ± 1.13, 0.0263 ± 0.0091, respectively. We found that neonatal birth weights correlate with the number of nodes of placental surface arteries (correlation coefficient R=0.40) and placental weights (R=0.52) both. However, the number of nodes of placental surface arteries was not associated with the placental weights or the gestational age. We for the first time found that a topological factor, i.e., the number of nodes of placental surface arteries correlated with neonatal growth. There was no correlation between numbers of nodes and placental weights. This suggests that the number of nodes affects fetal growth independent of placental weights. A topological factor of placental vasculization might significantly affect fetal growth in utero and determine risks of vascular diseases in their future lives.

  12. Estrogen receptors α and β and aromatase as independent predictors for prostate cancer outcome.

    PubMed

    Grindstad, Thea; Skjefstad, Kaja; Andersen, Sigve; Ness, Nora; Nordby, Yngve; Al-Saad, Samer; Fismen, Silje; Donnem, Tom; Khanehkenari, Mehrdad Rakaee; Busund, Lill-Tove; Bremnes, Roy M; Richardsen, Elin

    2016-01-01

    Androgens are considered important in normal prostate physiology and prostate cancer (PCa) pathogenesis. However, androgen-targeted treatment preventing PCa recurrence is still lacking. This indicates additional mediators contributing to cancer development. We sought to determine the prognostic significance of estrogen receptors, ERα and -β, and the aromatase enzyme in PCa. Tissue microarrays were created from 535 PCa patients treated with radical prostatectomy. Expression of ERα, ERβ and aromatase were evaluated using immunohistochemistry. Representative tumor epithelial (TE) and tumor stromal (TS) areas were investigated separately. Survival analyses were used to evaluate the markers correlation to PCa outcome. In univariate analyses, ERα in TS was associated with delayed time to clinical failure (CF) (p = 0.042) and PCa death (p = 0.019), while ERβ was associated with reduced time to biochemical failure (BF) (p = 0.002). Aromatase in TS and TE was associated with increased time to BF and CF respectively (p = 0.016, p = 0.046). Multivariate analyses supported these observations, indicating an independent prognostic impact of all markers. When stratifying the analysis according to different surgical centers the results were unchanged. In conclusion, significant prognostic roles of ERα, ERβ and aromatase were discovered in the in PCa specimens of our large multicenter cohort. PMID:27610593

  13. Direct Effects, Compensation, and Recovery in Female Fathead Minnows Exposed to the Aromatase Inhibitor Fadrozole

    EPA Science Inventory

    A variety of chemicals present in the environment have the potential to inhibit aromatase, an enzyme critical to estrogen synthesis. The objective of this study was to provide a detailed characterization of the molecular and biochemical responses of female fathead minnows to a m...

  14. Hypothesis testing with computational modeling: linking aromatase inhibition with plasma vitellogenin dynamics in fathead minnows

    EPA Science Inventory

    Fadrozole inhibits aromatase (CYP19A), a key enzyme that converts testosterone to estradiol (E2). In fish, E2 concentrations control hepatic synthesis ofthe glycolipoprotein vitellogenin (VTG), an egg yolk precursor protein essential to oocyte development and larval survival. Whe...

  15. Direct Effects, Compensation, and Recovery in Female Fathead Minnows Exposed to a Model Aromatase Inhibitor

    EPA Science Inventory

    The paper reports on the effects of a model aromatase inhibitor, fadrozole, on molecular and biochemical endpoints within the fathead minnow reproductive axis. Unlike previous studies, this work incorporated extensive time-course characterization over the course of an 8 d exposu...

  16. Sex Amphibian, Xenopus tropicalis, following Larval Exposure to an Aromatase Inhibitor

    EPA Science Inventory

    Aromatase is a steroidogenic enzyme that catalyzes the conversion of androgens to estrogens in vertebrates. Modulation of this enzyme’s activity by xenobiotic exposure has been shown to adversely affect gonadal differentiation in a number of diverse species. We hypothesized tha...

  17. Estrogen receptors α and β and aromatase as independent predictors for prostate cancer outcome

    PubMed Central

    Grindstad, Thea; Skjefstad, Kaja; Andersen, Sigve; Ness, Nora; Nordby, Yngve; Al-Saad, Samer; Fismen, Silje; Donnem, Tom; Khanehkenari, Mehrdad Rakaee; Busund, Lill-Tove; Bremnes, Roy M.; Richardsen, Elin

    2016-01-01

    Androgens are considered important in normal prostate physiology and prostate cancer (PCa) pathogenesis. However, androgen-targeted treatment preventing PCa recurrence is still lacking. This indicates additional mediators contributing to cancer development. We sought to determine the prognostic significance of estrogen receptors, ERα and -β, and the aromatase enzyme in PCa. Tissue microarrays were created from 535 PCa patients treated with radical prostatectomy. Expression of ERα, ERβ and aromatase were evaluated using immunohistochemistry. Representative tumor epithelial (TE) and tumor stromal (TS) areas were investigated separately. Survival analyses were used to evaluate the markers correlation to PCa outcome. In univariate analyses, ERα in TS was associated with delayed time to clinical failure (CF) (p = 0.042) and PCa death (p = 0.019), while ERβ was associated with reduced time to biochemical failure (BF) (p = 0.002). Aromatase in TS and TE was associated with increased time to BF and CF respectively (p = 0.016, p = 0.046). Multivariate analyses supported these observations, indicating an independent prognostic impact of all markers. When stratifying the analysis according to different surgical centers the results were unchanged. In conclusion, significant prognostic roles of ERα, ERβ and aromatase were discovered in the in PCa specimens of our large multicenter cohort. PMID:27610593

  18. Potential contribution of aromatase inhibition to the effects of nicotine and related compounds on the brain.

    PubMed

    Biegon, Anat; Alia-Klein, Nelly; Fowler, Joanna S

    2012-01-01

    Cigarette smoking continues to be a major public health problem, and while smoking rates in men have shown some decrease over the last few decades, smoking rates among girls and young women are increasing. Practically all of the important aspects of cigarette smoking and many effects of nicotine are sexually dimorphic (reviewed by Pogun and Yararbas, 2009). Women become addicted more easily than men, while finding it harder to quit. Nicotine replacement appears to be less effective in women. This may be linked to the observation that women are more sensitive than men to non-nicotine cues or ingredients in cigarettes. The reasons for these sex differences are mostly unknown. Several lines of evidence suggest that many of the reported sex differences related to cigarette smoking may stem from the inhibitory effects of nicotine and other tobacco alkaloids on estrogen synthesis via the enzyme aromatase (cyp19a gene product). Aromatase is the last enzyme in estrogen biosynthesis, catalyzing the conversion of androgens to estrogens. This review provides a summary of experimental evidence supporting brain aromatase as a potential mediator and/or modulator of nicotine actions in the brain, contributing to sex differences in smoking behavior. Additional research on the interaction between tobacco smoke, nicotine, and aromatase may help devise new, sex specific methods for prevention and treatment of smoking addiction.

  19. A Study to Evaluate Genetic Predictors of Aromatase Inhibitor Musculoskeletal Symptoms (AIMSS) | Division of Cancer Prevention

    Cancer.gov

    E1Z11 is a study to determine whether certain genetic information can predict which breast cancer patients will discontinue treatment with AIs due to the development of musculoskeletal symptoms (MSS). Women with stage 1-111 breast cancer who are prescribed the aromatase inhibitor anastrozole as treatment may join. |

  20. Histopathologic Effects in Marine Fish Treated with Estrogens or an Aromatase Inhibitor

    EPA Science Inventory

    Endocrine-disrupting chemicals, such as the estrogens estradiol (E2) and ethinylestradiol (EE2) , have been reported to affect fish reproduction. Androstatrienedione (ATD) is a known aromatase inhibitor which inhibits the conversion of testosterone to estradiol. The intent of thi...

  1. Validation of murine and human placental explant cultures for use in sex steroid and phase II conjugation toxicology studies

    PubMed Central

    Sato, Brittany L.; Ward, Monika A.; Astern, Joshua M.; Kendal-Wright, Claire E.; Collier, Abby C.

    2014-01-01

    Human primary placental explant culture is well established for cytokine signaling and toxicity, but has not been validated for steroidogenic or metabolic toxicology. The technique has never been investigated in the mouse. We characterized human and mouse placental explants for up to 96hr in culture. Explant viability (Lactate dehydrogenase) and sex steroid levels were measured in media using spectrophotometry and ELISA, respectively. Expression and activities of the steroidogenic (3β-hydroxysteroid dehydrogenase, Cytochrome P45017A1, Cytochrome P45019), conjugation (UDP-glucuronosyltransferase, sulfotransferase (SULT)), and regeneration (β-glucuronidase, arylsulfatase C (ASC)) enzymes were determined biochemically in tissues with fluorimetric and spectrophotometric assays, and western blot. Explants were viable up to 96hr, but progesterone, estrone, and 17β-estradiol secretion decreased. Steroidogenic enzyme expression and activities were stable in mouse explants and similar to levels in freshly isolated tissues, but were lower in human explants than in fresh tissue (P<0.01). Human and mouse explants exhibited significantly less conjugation after 96hr, SULT was not detected in the mouse, and neither explants had active ASC, although proteins were expressed. Mouse explants may be useful for steroid biochemistry and endocrine disruption studies, but not metabolic conjugation. In contrast, human explants may be useful for studying conjugation for <48hr, but not for steroid/endocrine studies. PMID:25283089

  2. Cesarean Delivery for a Life-threatening Preterm Placental Abruption

    PubMed Central

    Okafor, II; Ugwu, EO

    2015-01-01

    Placental abruption is one of the major life-threatening obstetric conditions. The fetomaternal outcome of a severe placental abruption depends largely on prompt maternal resuscitation and delivery. A case of severe preterm placental abruption with intrauterine fetal death. Following a failed induction of labor with a deteriorating maternal condition despite resuscitation, emergency cesarean delivery was offered with good maternal outcome. Cesarean delivery could avert further disease progression and possible maternal death in cases of severe preterm placental abruption where vaginal delivery is not imminent. However, further studies are necessary before this could be recommended for routine clinical practice. PMID:27057388

  3. Probing the origins of aromatase inhibitory activity of disubstituted coumarins via QSAR and molecular docking

    PubMed Central

    Worachartcheewan, Apilak; Suvannang, Naravut; Prachayasittikul, Supaluk; Prachayasittikul, Virapong; Nantasenamat, Chanin

    2014-01-01

    This study investigated the quantitative structure-activity relationship (QSAR) of imidazole derivatives of 4,7-disubstituted coumarins as inhibitors of aromatase, a potential therapeutic protein target for the treatment of breast cancer. Herein, a series of 3,7- and 4,7-disubstituted coumarin derivatives (1-34) with R1 and R2 substituents bearing aromatase inhibitory activity were modeled as a function of molecular and quantum chemical descriptors derived from low-energy conformer geometrically optimized at B3LYP/6-31G(d) level of theory. Insights on origins of aromatase inhibitory activity was afforded by the computed set of 7 descriptors comprising of F10[N-O], Inflammat-50, Psychotic-80, H-047, BELe1, B10[C-O] and MAXDP. Such significant descriptors were used for QSAR model construction and results indicated that model 4 afforded the best statistical performance. Good predictive performance were achieved as verified from the internal (comprising the training and the leave-one-out cross-validation (LOO-CV) sets) and external sets affording the following statistical parameters: R2Tr = 0.9576 and RMSETr = 0.0958 for the training set; Q2CV = 0.9239 and RMSECV = 0.1304 for the LOO-CV set as well as Q2Ext = 0.7268 and RMSEExt = 0.2927 for the external set. Significant descriptors showed correlation with functional substituents, particularly, R1 in governing high potency as aromatase inhibitor. Molecular docking calculations suggest that key residues interacting with the coumarins were predominantly lipophilic or non-polar while a few were polar and positively-charged. Findings illuminated herein serve as the impetus that can be used to rationally guide the design of new aromatase inhibitors. PMID:26417339

  4. Product of aromatase activity in intact LNCaP and MCF-7 human cancer cells.

    PubMed

    Castagnetta, L A; Granata, O M; Bellavia, V; Amodio, R; Scaccianoce, E; Notarbartolo, M; Follari, M R; Miceli, M D; Carruba, G

    1997-04-01

    We investigated conversion rates of androgens to estrogens in cultured, hormone-responsive prostate (LNCaP) and breast (MCF-7) human cancer cells. For this purpose, we adopted an intact cell analysis, whereby cells were incubated for different incubation times in the presence of close-to-physiological (1 nM) or supraphysiological (1 microM) concentrations of labelled androgen precursors, i.e. testosterone (T) and androstenedione (delta4Ad). The aromatase activity, as measured by estrogen formation, was detected in LNCaP cells (0.5 pmol/ml), even though to a significantly lower extent than in MCF-7 cells (5.4 pmol/ml), using 1 microM T after 72 h incubation. Surprisingly, LNCaP cells displayed a much higher aromatase activity when T was used as a substrate with respect to delta4Ad. In either cell line, T transformation to delta4Ad was relatively low, attaining only 2.8% in LNCaP and 7.5% MCF-7 cells. However, T was mostly converted to conjugates (over 95%), glucuronides and some sulphates, in LNCaP cells, whereas it was only partly converted to sulphates (<10%) in MCF-7 cells. Aromatase activity seems to be inconsistent in LNCaP cells, being strongly affected by culture conditions, especially by fetal calf serum (FCS). Further studies should assess the regulation of aromatase expression by serum or growth factors in different human cancer cells, also using anti-aromatase and/or anti-estrogen compounds, in different culture conditions.

  5. ALTERATIONS IN THE TRANSCRIPTOME AND PROTEOME OF ZEBRAFISH (DANIO RERIO) EXPOSED TO FADROZOLE, A MODEL AROMATASE INHIBITOR

    EPA Science Inventory

    Fadrozole is a reversible, competitive inhibitor of aromatase activity and therefore an endocrine-disrupting compound (EDC) that disrupts steroidogenesis by inhibiting the conversion of testosterone to 172-estradiol. While fadrozole is a therapeutic drug with generally no enviro...

  6. EFFECTS OF INCUBATION TEMPERATURE AND ESTROGEN EXPOSURE ON AROMATASE ACTIVITY IN THE BRAIN AND GONADS OF EMBRYONIC ALLIGATORS

    EPA Science Inventory

    During embryogenesis, incubation temperature and the hormonal environment influence gonadal differentiation of some reptiles, including all crocodilians. Current evidence suggests that aromatase, the enzyme that converts androgens to estrogens, has a role in sexual differentiatio...

  7. Effects of Pharmaceuticals Used for Breast Cancer Treatment on Reproduction and Aromatase Activity in a Marine Fish

    EPA Science Inventory

    Laboratory experiments were conducted with the marine fish cunner (Tautogolabrus adspersus) to evaluate whether four pharmaceuticals used in breast cancer treatment have an impact on reproduction or aromatase activity. Tamoxifen binds to estrogen receptors, while anastrozole, let...

  8. Foetal placental blood flow in the lamb

    PubMed Central

    Faber, J. Job; Green, Thomas J.

    1972-01-01

    1. Fifteen sheep foetuses of 1·5-5·2 kg body weight were prepared with indwelling arterial and venous catheters for experimentation one to six days later. 2. Unanaesthetized foetuses were found to have mean arterial and central venous blood pressures of 40 ± 1·5 (S.E. of mean) and 2·0 ± 0·3 (S.E. of mean) mm Hg respectively, compared to intra-uterine pressure. Intra-uterine pressure was 16 ± 0·8 (S.E. of mean) mm Hg with respect to atmospheric pressure at mid-uterine level. 3. Mean placental blood flow of the foetuses was 199 ± 20 (S.E. of mean) ml./(min.kg body wt.). Mean cardiac output in eleven of the foetuses was 658 ± 102 (S.E. of mean) ml./(min.kg). 4. Mean foetal and maternal colloid osmotic pressures were 17·5 ± 0·7 (S.E. of mean) and 20·5 ± 0·6 (S.E. of mean) mm Hg respectively at 38° C. 5. Intravenous infusions into six ewes of 1·8 mole of mannitol and 0·4 mole of NaCl resulted in significant increases in foetal plasma osmolarity, sodium, potassium, and haemoglobin concentrations, without detectable transfer of mannitol to the foetal circulation. 6. In the sheep placenta there is osmotic and hydrostatic equilibration of water. As a consequence, there should be an interaction between foetal placental blood flow and foetal water exchange with the maternal circulation. It was concluded that this interaction tends to stabilize foetal placental blood flow. PMID:5039279

  9. Placental hormones, nutrition, and fetal development.

    PubMed

    Mulay, S; Browne, C A; Varma, D R; Solomon, S

    1980-02-01

    Fetal growth retardation due to maternal malnutrition is widespread especially in the Third World. Little is known about the mechanisms that regulate the growth of the fetus and placenta during protein malnutrition. It is known that the placental size and levels of circulating placental hormones such as human chorionic gonadotrophins (hCG), human placental lactogen (hPL), and estrogens are affected by the nutritional status of the mother. There is suggestive evidence that during malnutrition, hPL may increase lipolysis and exert a glucose sparing effect in the mother, thereby promoting glucose availability to the fetus. We have studied the influence of dietary protein deficiency on the binding of dexamethasone to the specific cytosol receptors in adult and fetal tissues. A low protein diet in adult male rats is associated with a decrease in dexamethasone binding to liver cytosol receptors. On the other hand, protein deprivation in pregnant female rats leads to an increase in dexamethasone binding to liver cytosol receptors of both the mother and fetus. However, the influences of maternal protein deprivation on dexamethasone receptors in the fetal liver and lungs are not similar. At 21 days gestation the binding of dexamethasone to fetal lung receptors of protein-deficient mothers is lower than that in the controls. These differences at a critical time in the fetal lung development indicate that a fall in receptors for dexamethasone may lead to impaired phospholipid synthesis in fetuses of protein-deficient mothers and point to the importance of nutritional factors in the biochemistry of fetal development. PMID:7353684

  10. Sildenafil attenuates placental ischemia-induced hypertension.

    PubMed

    George, Eric M; Palei, Ana C; Dent, Edward A; Granger, Joey P

    2013-08-15

    Preeclampsia is a complication of pregnancy that is marked by hypertension, proteinuria, and maternal endothelial dysfunction. A central factor in the etiology of the disease is the development of placental hypoxia/ischemia, which releases pathogenic soluble factors. There is currently no effective treatment for preeclampsia, but the phosphodiesterase-5 (PDE-5) inhibitor sildenafil has been suggested, as PDE-5 is enriched in the uterus, and its antagonism could improve uteroplacental function. Here, we report in the reduced uterine perfusion pressure (RUPP) rat model that administration of oral sildenafil is effective in attenuating placental ischemia-induced hypertension during gestation. RUPP animals have significantly elevated arterial pressure compared with control animals (132 ± 3 vs. 100 ± 2 mmHg; P < 0.05). Administration of oral sildenafil (45 mg·kg⁻¹·day⁻¹) had no effect on blood pressure in control rats but decreased pressure in RUPP rats (115 ± 1 mmHg; P < 0.05). RUPP induced changes in placental sFlt-1, and vascular endothelial growth factor (VEGF) was unaffected by sildenafil administration, as was the decrease in free plasma VEGF. RUPP animals had a significant increase in medullary PDE-5/β-actin ratio (1 ± 0.14 vs. 1.63 ± 0.18; P < 0.05) expression with a resulting reduction in renal medullary cGMP (1.5 ± 0.15 vs. 0.99 ± 0.1 pmol/μg protein, P < 0.05) compared with controls. Although sildenafil had no effect on renal medullary cGMP in control animals, it significantly increased cGMP in RUPP animals (1.3 ± 0.1 pmol/μg protein; P < 0.05). These data suggest that sildenafil might provide an effective therapeutic option for the management of hypertension during preeclampsia. PMID:23785075

  11. Maternal environment and placental vascularization in small ruminants.

    PubMed

    Bairagi, S; Quinn, K E; Crane, A R; Ashley, R L; Borowicz, P P; Caton, J S; Redden, R R; Grazul-Bilska, A T; Reynolds, L P

    2016-07-01

    Uteroplacental development is a crucial step facilitating conceptus growth. Normal placental development comprises extensive placental angiogenesis to support fetoplacental transport, meeting the metabolic demands of the fetus. Compromised pregnancies due to maternal stressors such as over or undernutrition, maternal age or parity, altered body mass index, or genetic background result in altered vascular development of the placenta. This negatively affects placental growth and placental function and ultimately results in poor pregnancy outcomes. Nonetheless, the placenta acts as a sensor to the maternal stressors and undergoes modifications, which some have termed placental programming, to ensure healthy development of the conceptus. Sex steroid hormones such as estradiol-17β and progesterone, chemokines such as chemokine ligand 12, and angiogenic/vasoactive factors such as vascular endothelial growth factors, placental growth factor, angiopoietins, and nitric oxide regulate uteroplacental development and hence are often used as therapeutic targets to rescue compromised pregnancies. Interestingly, the presence of sex steroid receptors has been identified in the fetal membranes (developing fetal placenta). Environmental steroid mimetics known as endocrine disrupting compounds disrupt conceptus development and lead to transgenerational impairments by epigenetic modification of placental gene expression, which is another area deserving intense research efforts. This review attempts to summarize current knowledge concerning intrinsic and extrinsic factors affecting selected reproductive functions with the emphasis on placental development. PMID:27173956

  12. Seasonal changes of androgen receptor, estrogen receptors and aromatase expression in the medial preoptic area of the wild male ground squirrels (Citellus dauricus Brandt).

    PubMed

    Zhang, F; Wang, J; Jiao, Y; Zhang, L; Zhang, H; Sheng, X; Han, Y; Yuan, Z; Weng, Q

    2016-01-01

    The wild ground squirrel is a typical seasonal breeder. In this study, using RT-PCR, western blot and immunohistochemistry, we investigated the mRNA and protein expressions of androgen receptor (AR), estrogen receptors α and β (ERα and ERβ) and aromatase cytochrome P450 (P450arom) in the medial preoptic area (MPOA) of hypothalamus of the wild male ground squirrel during the breeding season (April), the non-breeding season (June) and pre-hibernation (September). AR, ERα, ERβ and P450arom protein/mRNA were present in the MPOA of all seasons detected. The immunostaining of AR and ERα showed no significant changes in different periods, whereas ERβ and P450arom had higher immunoreactivities during the breeding season and pre-hibernation when compared to those of the non-breeding season. Consistently, both the protein and mRNA levels of P450arom and ERβ were higher in the MPOA of pre-hibernation and the breeding season than in the non-breeding season, whereas no significant difference amongst the three periods was observed for AR and ERα levels. These findings suggested that the MPOA of hypothalamus may be a direct target of androgen and estrogen. Androgen may play important regulatory roles through its receptor and/or the aromatized estrogen in the MPOA of hypothalamus of the wild male ground squirrels. PMID:27349316

  13. Seasonal Changes of Androgen Receptor, Estrogen Receptors and Aromatase Expression in the Medial Preoptic Area of the Wild Male Ground Squirrels (Citellus Dauricus Brandt)

    PubMed Central

    Zhang, F.; Wang, J.; Jiao, Y.; Zhang, L.; Zhang, H.; Sheng, X.; Han, Y.; Yuan, Z.; Weng, Q.

    2016-01-01

    The wild ground squirrel is a typical seasonal breeder. In this study, using RT-PCR, western blot and immunohistochemistry, we investigated the mRNA and protein expressions of androgen receptor (AR), estrogen receptors a and β (ERα and ERβ) and aromatase cytochrome P450 (P450arom) in the medial preoptic area (MPOA) of hypothalamus of the wild male ground squirrel during the breeding season (April), the non-breeding season (June) and pre-hibernation (September). AR, ERα, ERβ and P450arom protein/mRNA were present in the MPOA of all seasons detected. The immunostaining of AR and ERα showed no significant changes in different periods, whereas ERβ and P450arom had higher immunoreactivities during the breeding season and pre-hibernation when compared to those of the non-breeding season. Consistently, both the protein and mRNA levels of P450arom and ERβ were higher in the MPOA of pre-hibernation and the breeding season than in the non-breeding season, whereas no significant difference amongst the three periods was observed for AR and ERα levels. These findings suggested that the MPOA of hypothalamus may be a direct target of androgen and estrogen. Androgen may play important regulatory roles through its receptor and/or the aromatized estrogen in the MPOA of hypothalamus of the wild male ground squirrels. PMID:27349316

  14. Aromatase imaging with [N-methyl-C-11]vorozole PET in healthy men and women

    SciTech Connect

    Biegon, Anat; Fowler, Joanna S.; Alexoff, David L.; Kim, Sung Won; Logan, Jean; Pareto, Deborah; Schlyer, David; Wang, Gene-Jack

    2015-02-19

    Aromatase, the last and obligatory enzyme catalyzing estrogen biosynthesis from androgenic precursors, can be labeled in vivo with ¹¹C-vorozole. Aromatase inhibitors are widely used in breast cancer and other endocrine conditions. The present study aims to provide baseline information defining aromatase distribution in healthy men and women, against which its perturbation in pathological situations can be studied. Methods: ¹¹C-vorozole (111-296 MBq/subject) was injected I.V in 13 men and 20 women (age range 23 to 67). PET data were acquired over a 90 minute period. Each subject had 4 scans, 2/day separated by 2-6 weeks, including brain and torso or pelvis scans. Young women were scanned at 2 discrete phases of the menstrual cycle (midcycle and late luteal). Men and postmenopausal women were also scanned following pretreatment with a clinical dose of the aromatase inhibitor letrozole (“blocking” studies). Time activity curves were obtained and standard uptake values (SUV) calculated for major organs including brain, heart, lungs, liver, kidneys, spleen, muscle, bone and male and female reproductive organs (penis, testes, uterus, ovaries). Organ and whole body radiation exposures were calculated using Olinda software. Results: Liver uptake was higher than all other organs, but was not blocked by pretreatment with letrozole. Mean SUVs in men were higher than in women, and brain uptake was blocked by letrozole. Male brain SUVs were also higher than all other organs (ranging from 0.48±0.05 in lungs to 1.5±0.13 in kidneys). Mean ovarian SUVs (3.08±0.7) were comparable to brain levels and higher than all other organs. Furthermore, ovarian SUVs In young women around the time of ovulation (midcycle) were significantly higher than those measured in the late luteal phase, while aging and cigarette smoking reduced ¹¹C-vorozole uptake. Conclusions: PET with ¹¹C-vorozole is useful for assessing physiological changes in estrogen synthesis capacity in the human body

  15. Aromatase imaging with [N-methyl-C-11]vorozole PET in healthy men and women

    DOE PAGES

    Biegon, Anat; Fowler, Joanna S.; Alexoff, David L.; Kim, Sung Won; Logan, Jean; Pareto, Deborah; Schlyer, David; Wang, Gene-Jack

    2015-02-19

    Aromatase, the last and obligatory enzyme catalyzing estrogen biosynthesis from androgenic precursors, can be labeled in vivo with ¹¹C-vorozole. Aromatase inhibitors are widely used in breast cancer and other endocrine conditions. The present study aims to provide baseline information defining aromatase distribution in healthy men and women, against which its perturbation in pathological situations can be studied. Methods: ¹¹C-vorozole (111-296 MBq/subject) was injected I.V in 13 men and 20 women (age range 23 to 67). PET data were acquired over a 90 minute period. Each subject had 4 scans, 2/day separated by 2-6 weeks, including brain and torso or pelvismore » scans. Young women were scanned at 2 discrete phases of the menstrual cycle (midcycle and late luteal). Men and postmenopausal women were also scanned following pretreatment with a clinical dose of the aromatase inhibitor letrozole (“blocking” studies). Time activity curves were obtained and standard uptake values (SUV) calculated for major organs including brain, heart, lungs, liver, kidneys, spleen, muscle, bone and male and female reproductive organs (penis, testes, uterus, ovaries). Organ and whole body radiation exposures were calculated using Olinda software. Results: Liver uptake was higher than all other organs, but was not blocked by pretreatment with letrozole. Mean SUVs in men were higher than in women, and brain uptake was blocked by letrozole. Male brain SUVs were also higher than all other organs (ranging from 0.48±0.05 in lungs to 1.5±0.13 in kidneys). Mean ovarian SUVs (3.08±0.7) were comparable to brain levels and higher than all other organs. Furthermore, ovarian SUVs In young women around the time of ovulation (midcycle) were significantly higher than those measured in the late luteal phase, while aging and cigarette smoking reduced ¹¹C-vorozole uptake. Conclusions: PET with ¹¹C-vorozole is useful for assessing physiological changes in estrogen synthesis capacity in the

  16. The Cytochrome P450 Homepage

    PubMed Central

    2009-01-01

    The Cytochrome P450 Homepage is a universal resource for nomenclature and sequence information on cytochrome P450 (CYP) genes. The site has been in continuous operation since February 1995. Currently, naming information for 11,512 CYPs are available on the web pages. The P450 sequences are manually curated by David Nelson, and the nomenclature system conforms to an evolutionary scheme such that members of CYP families and subfamilies share common ancestors. The organisation and content of the Homepage are described. PMID:19951895

  17. Survival in patients with metastatic breast cancer: analysis of randomized studies comparing oral aromatase inhibitors versus megestrol.

    PubMed

    Messori, A; Cattel, F; Trippoli, S; Vaiani, M

    2000-10-01

    In patients with metastatic breast cancer, second-line therapy with aromatase inhibitors can improve survival in comparison with megestrol. We conducted a meta-analysis to assess the effectiveness of aromatase inhibitors versus megestrol. After a Medline search, three trials (evaluating letrozole, anastrozole or exemestane versus megestrol) were included in the survival meta-analysis. Our methodology retrieved patient-level information on survival. In comparison with megestrol, aromatase inhibitors prolonged survival at levels of statistical significance (relative death risk for oral aromatase inhibitors=0.79, 95% confidence interval 0.69-0.91; p=0.0011). A lifetime analysis of the pooled survival curves of aromatase inhibitors versus megestrol found a mean survival gain of 4.1 months per patient. Aromatase inhibitors confer a significant survival benefit to patients with metastatic breast cancer as compared with megestrol. A preliminary calculation of the cost per life year gained shows that the pharmacoeconomic profile of these drugs is favorable. PMID:11129731

  18. Farnesoid X receptor, through the binding with steroidogenic factor 1-responsive element, inhibits aromatase expression in tumor Leydig cells.

    PubMed

    Catalano, Stefania; Malivindi, Rocco; Giordano, Cinzia; Gu, Guowei; Panza, Salvatore; Bonofiglio, Daniela; Lanzino, Marilena; Sisci, Diego; Panno, Maria Luisa; Andò, Sebastiano

    2010-02-19

    The farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily that regulates bile acid homeostasis. It is expressed in the liver and the gastrointestinal tract, but also in several non-enterohepatic tissues including testis. Recently, FXR was identified as a negative modulator of the androgen-estrogen-converting aromatase enzyme in human breast cancer cells. In the present study we detected the expression of FXR in Leydig normal and tumor cell lines and in rat testes tissue. We found, in rat Leydig tumor cells, R2C, that FXR activation by the primary bile acid chenodeoxycholic acid (CDCA) or a synthetic agonist GW4064, through a SHP-independent mechanism, down-regulates aromatase expression in terms of mRNA, protein levels, and its enzymatic activity. Transient transfection experiments, using vector containing rat aromatase promoter PII, evidenced that CDCA reduces basal aromatase promoter activity. Mutagenesis studies, electrophoretic mobility shift, and chromatin immunoprecipitation analysis reveal that FXR is able to compete with steroidogenic factor 1 in binding to a common sequence present in the aromatase promoter region interfering negatively with its activity. Finally, the FXR-mediated anti-proliferative effects exerted by CDCA on tumor Leydig cells are at least in part due to an inhibition of estrogen-dependent cell growth. In conclusion our findings identify for the first time the activators of FXR as negative modulators of the aromatase enzyme in Leydig tumor cell lines.

  19. Design, synthesis, and biological evaluation of resveratrol analogues as aromatase and quinone reductase 2 inhibitors for chemoprevention of cancer

    SciTech Connect

    Sun, Bin; Hoshino, Juma; Jermihov, Katie; Marler, Laura; Pezzuto, John M.; Mesecar, Andrew D.; Cushman, Mark

    2012-07-11

    A series of new resveratrol analogues were designed and synthesized and their inhibitory activities against aromatase were evaluated. The crystal structure of human aromatase (PDB 3eqm) was used to rationalize the mechanism of action of the aromatase inhibitor 32 (IC{sub 50} 0.59 {mu}M) through docking, molecular mechanics energy minimization, and computer graphics molecular modeling, and the information was utilized to design several very potent inhibitors, including compounds 82 (IC{sub 50} 70 nM) and 84 (IC{sub 50} 36 nM). The aromatase inhibitory activities of these compounds are much more potent than that for the lead compound resveratrol, which has an IC{sub 50} of 80 {mu}M. In addition to aromatase inhibitory activity, compounds 32 and 44 also displayed potent QR2 inhibitory activity (IC{sub 50} 1.7 {mu}M and 0.27 {mu}M, respectively) and the high-resolution X-ray structures of QR2 in complex with these two compounds provide insight into their mechanism of QR2 inhibition. The aromatase and quinone reductase inhibitors resulting from these studies have potential value in the treatment and prevention of cancer.

  20. Placental measurements associated with intelligence quotient at age 7 years.

    PubMed

    Misra, D P; Salafia, C M; Charles, A K; Miller, R K

    2012-06-01

    We hypothesized that placental villous branching that is measured by disk chorionic plate expansion and disk thickness is correlated with factors also involved in regulation of branching growth of other fetal viscera (e.g. lung, kidney) including neuronal dendrites, and thus may be associated with variation in childhood intelligence quotient (IQ). IQ at age 7 years was assessed using the Wechsler Intelligence Scale for Children. Placental measures [placental weight (g), thickness (mm), chorionic plate surface diameters (cm), area (cm2), shape, and cord length and cord eccentricity] were independent variables in regression analyses of age 7-year IQ in 12,926 singleton term live born infants with complete placental data. Analyses were stratified on gender with adjustment for socioeconomic status, race, parity, gestational age, exact age at testing and centered parental ages. After adjustment for covariates, placental measurements were independently associated with IQ at age 7 years but results varied by gender. Chorionic plate diameters were only associated with higher IQ in girls. Placental thickness was positively associated with higher IQ for boys and girls. We have previously shown that placental measures affect age 7-year body mass index and diastolic blood pressure. Here we demonstrate that specific measures, placental chorionic plate diameters in girls and disk thickness, independent of gender, are correlated with age 7-year IQ. Further exploration of the possible interaction of these factors on the placental villous arborization reflected by the chorionic plate expansion and placental thickness that correlate with age 7-year IQ, as well as other age 7 somatic features as previously addressed, is indicated.

  1. Placental vanadium in gestational diabetes mellitus.

    PubMed

    Manci, E A; Coffin, C M; Smith, S M; Ganong, C A

    1989-01-01

    Although many studies in animal models and in cell cultures have shown that vanadate has insulin-like effects, it has not been studied in human diabetes mellitus. In this study the levels of vanadium in human placentae from 23 pregnancies complicated by gestational diabetes mellitus were compared with 18 uncomplicated non-diabetic pregnancies closely matched for maternal age, gravidity, and gestational age. Using the unpaired Student's t-test, the mid-disc placental levels in gestational diabetes (7.62 +/- 1.29 micrograms/g dry weight) were significantly lower (p less than 0.05) than controls (8.73 +/- 1.85 micrograms/g dry weight). These findings appear to be independent of placental size and birthweight. When these data were analyzed according to treatment, the vanadium levels in insulin-treated cases (8.07 +/- 1.32 micrograms/g dry weight) were not significantly different from the matched controls (8.84 +/- 1.69 micrograms/dry weight); the levels in noninsulin treated cases (7.08 +/- 1.25 micrograms/g dry weight), however, were significantly (p less than 0.005) lower than controls (8.99 +/- 1.96 micrograms/g dry weight). It is interesting to speculate that there may be increased binding of vanadium to maternal tissues in human diabetes mellitus when insulin is deficient.

  2. Assisted Reproduction Technologies Impair Placental Steroid Metabolism

    PubMed Central

    Collier, Abby C.; Miyagi, Shogo J.; Yamauchi, Yasuhiro; Ward, Monika A.

    2009-01-01

    The placenta plays a vital role in pregnancy by facilitating steroid passage from maternal to fetal circulation and/or direct production of hormones. Using a murine model, we demonstrated the differences in placental steroid metabolism between pregnancies conceived naturally and with assisted reproduction technologies (ART): in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). While the ovarian steroid production was similar (estrone, 17β-estradiol) or higher (estriol) in ART pregnancies compared to mating, the levels of placental estriol were significantly lower in ART group. Placentas from ART had significantly higher activities of the steroid metabolizing enzymes UDP-glucuronosyltransferase (UGT) and sulfotransferase (SULT), which in ICSI were also coupled with decreased activity of the steroid regenerating enzymes β-glucuronidase (β-G) and Aryl sulfatase (AS). Levels of steroid metabolites androstane-3α-17β-diol glucuronide and dehydroepiandrosterone sulfate were higher in fetal compared to maternal blood in ART, but not in mating. This study demonstrates that in murine ART pregnancies, higher metabolism and clearance of steroids by the placenta may seriously affect the passage of essential hormones to the fetus. If a similar phenomenon exists in humans, this could provide a plausible explanation for obstetric and neonatal complications associated with ART, including the higher incidence of low birth weight babies. PMID:19406239

  3. Confined placental mosaicisms and uniparental disomy

    SciTech Connect

    Kalousek, D.K.; Langlois, S.; Harrison, K.J.

    1994-09-01

    Approximately 2% of pregnancies studied with chorionic villous sampling (CVS) show confined placental mosaicism (CPM) which persists to term in 50-70% of cases. An increased frequency of complications, such as intrauterine fetal growth restriction or intrauterine death, is observed in these pregnancies. As trisomic zygote rescue is a common mechanism responsible for CPM, fetal uniparental disomy (UPD), resulting from the loss of the extra trisomic chromosome in the embryonic stem cells, would be expected to occur in a proportion of pregnancies with CPM. We have studied 27 pregnancies with CPM involving trisomies for chromosomes 2, 7, 9, 10, 12, and 16 for involvement of specific cell lineage(s) and levels of mosaicism in term placentas. Also, DNA from the parents and infant was analyzed for UPD or biparental disomy (BPD). Five infants with UPD for chromosome 16 and one infant with UPD for chromosome 7 were detected. All other infants showed BPD for the chromosome involved in CPM. For trisomy 16 mosaic gestations, a close correlation between high levels of trisomic cells in placenta and intrauterine fetal growth restriction has been found irrespective of the type of disomy present in the infant. The effect of other trisomies (2, 7, 9, 10, 12) on placental function appears to be similar, but the low numbers of pregnancies studied and lack of detection of UPD for chromosomes 2, 9, 10 and 12 does not allow a definitive conclusion.

  4. Comparison of placental blood microscopy and the ICT HRP2 rapid diagnostic test to detect placental malaria.

    PubMed

    Aguilar, Ruth; Machevo, Sonia; Menéndez, Clara; Bardají, Azucena; Nhabomba, Augusto; Alonso, Pedro L; Mayor, Alfredo

    2012-09-01

    Monitoring interventions to prevent malaria in pregnancy requires sensitive detection of placental infection. Rapid diagnostic tests (RDTs) are good candidates, but little information is available on their sensitivity on placental blood. We have evaluated the agreement (kappa coefficient) between microscopy and a Plasmodium falciparum histidine-rich protein 2 (HRP2)-based immuno-chromatographic test (ICT) on placental blood from 1151 women at delivery. Prevalences of placental infection by microscopy and RDT were 5.1% and 5.0%, respectively, showing 82.9% agreement (p<0.0001). Discordances were found at low parasitemias (<500 parasites/μL) or negative microscopy. The results suggest that the HRP2-RDTs from ICT diagnostics is a good alternative to microscopy for diagnosing placental malaria at delivery.

  5. Evidence for placental compensation in cattle.

    PubMed

    Van Eetvelde, M; Kamal, M M; Hostens, M; Vandaele, L; Fiems, L O; Opsomer, G

    2016-08-01

    Prenatal development is known to be extremely sensitive to maternal and environmental challenges. In this study, we hypothesize that body growth and lactation during gestation in cattle reduce nutrient availability for the pregnant uterus, with consequences for placental development. Fetal membranes of 16 growing heifers and 27 fully grown cows of the Belgian Blue (BB) breed were compared to determine the effect of body growth on placental development. Furthermore, the fetal membranes of 49 lactating Holstein Friesian (HF) cows and 27 HF heifers were compared to study the impact of dam lactation compared to dam body growth. After parturition, calf birth weight and body measurements of dam and calf were recorded, as well as weight of total fetal membranes, cotyledons and intercotyledonary membranes. All cotyledons were individually measured to calculate both the surface of each individual cotyledon and the total cotyledonary surface per placenta. Total cotyledonary surface was unaffected by breed or the breed×parity interaction. Besides a 0.3 kg lower cotyledonary weight (P=0.007), heifer placentas had a smaller total cotyledonary surface compared with placentas of cows (0.48±0.017 v. 0.54±0.014 m2, respectively, P<0.001). Within the BB breed, fetal membranes of heifers had a 1.5 kg lower total weight and 1.0 kg lower intercotyledonary membrane weight (P<0.005) compared with cows. A cotyledon number of only 91±5.4 was found in multiparous BB dams, while growing BB heifers had a higher cotyledon number (126±6.7, P<0.001), but a greater proportion of smaller cotyledons (<40 cm2). Within the HF breed, no parity effect on intercotyledonary membrane weight, cotyledon number and individual cotyledonary surface was found. Placental efficiency (calf weight/total cotyledonary surface) was similar in HF and BB heifers but significantly higher in multiparous BB compared with multiparous HF dams (106.0±20.45 v. 74.3±12.27 kg/m2, respectively, P<0.001). Furthermore, a

  6. Xanthones from the botanical dietary supplement mangosteen (Garcinia mangostana) with aromatase inhibitory activity.

    PubMed

    Balunas, Marcy J; Su, Bin; Brueggemeier, Robert W; Kinghorn, A Douglas

    2008-07-01

    Twelve xanthone constituents of the botanical dietary supplement mangosteen (the pericarp of Garcinia mangostana) were screened using a noncellular, enzyme-based microsomal aromatase inhibition assay. Of these compounds, garcinone D (3), garcinone E (5), alpha-mangostin (8), and gamma-mangostin (9) exhibited dose-dependent inhibitory activity. In a follow-up cell-based assay using SK-BR-3 breast cancer cells that express high levels of aromatase, the most potent of these four xanthones was gamma-mangostin (9). Because xanthones may be consumed in substantial amounts from commercially available mangosteen products, the consequences of frequent intake of mangosteen botanical dietary supplements require further investigation to determine their possible role in breast cancer chemoprevention.

  7. Aromatase overexpression in dysfunctional adipose tissue links obesity to postmenopausal breast cancer.

    PubMed

    Wang, Xuyi; Simpson, Evan R; Brown, Kristy A

    2015-09-01

    The number of breast cancer cases has increased in the last a few decades and this is believed to be associated with the increased prevalence of obesity worldwide. The risk of breast cancer increases with age beyond menopause and the relationship between obesity and the risk of breast cancer in postmenopausal women is well established. The majority of postmenopausal breast cancers are estrogen receptor (ER) positive and estrogens produced in the adipose tissue promotes tumor formation. Obesity results in the secretion of inflammatory factors that stimulate the expression of the aromatase enzyme, which converts androgens into estrogens in the adipose tissue. Evidence demonstrating a link between obesity and breast cancer has led to the investigation of metabolic pathways as novel regulators of estrogen production, including pathways that can be targeted to inhibit aromatase specifically within the breast. This review aims to present some of the key findings in this regard.

  8. Aromatase Inhibitors for Endometriosis-Associated Infertility; Do We Have Sufficient Evidence?

    PubMed Central

    Abu Hashim, Hatem

    2016-01-01

    Orally active aromatase inhibitors (AIs) have gained attention for treatment of infertile women with endometriosis in whom aromatase p450 is aberrantly expressed. This review aimed to critically appraise and summarize the available evidence concerning the use of AIs for management of endometriosis-associated infertility. PubMed was searched to May 2015 with the following key words: endometriosis, infertility and aromatase. Priority was given for randomized controlled trials (RCTs) followed by other study designs. Main outcome measures were as follows: rates of clinical pregnancy, miscarriage and live birth as well as endocrine outcomes. Eighty-two abstracts were screened and six original articles were included. A RCT demonstrated that post-operative letrozole treatment did not improve spontaneous pregnancy rate. Another RCT reported no superiority of letrozole superovulation over clomiphene citrate (each combined with intrauterine insemination) in minimalmild endometriosis and previous laparoscopic treatment. Anastrozole significantly inhibited the growth of endometriotic cells and their estrogen production in culture. In assisted reproductive technology (ART) cycles, dual suppression (Agonist/anastrozole) was tested in a pilot study with a pregnancy rate of 45% however, high pregnancy loss (30%) occurred. A retrospective study showed that letrozole may improve endometrial receptivity in endometriotic patients undergoing in vitro fertilization (IVF). An opposite view from an in vitro study showed lower estradiol production and aromatase expression in cultured granulosa cells from endometriotic women undergoing IVF and marked reduction under letrozole. In conclusion, current evidence is limited. More trials are warranted to enhance our knowledge and provide a clear and unequivocal evidence to guide our clinical management of infertile women with endometriosis using AIs. PMID:27695608

  9. Testosterone and Adult Male Bone: Actions Independent of 5α-Reductase and Aromatase.

    PubMed

    Yarrow, Joshua F; Wronski, Thomas J; Borst, Stephen E

    2015-10-01

    Androgens and estrogens influence skeletal development and maintenance in males. However, the relative contributions of the circulating sex steroid hormones that originate from testicular/adrenal secretion versus those produced locally in bone via intracrine action require further elucidation. Our novel hypothesis is that testosterone exerts direct protective effects on the adult male skeleton independently of the actions of 5α-reductase or aromatase.

  10. Maternal dietary omega-3 fatty acids and placental function.

    PubMed

    Jones, Megan L; Mark, Peter J; Waddell, Brendan J

    2014-05-01

    The developing fetus requires substantial amounts of fatty acids to support rapid cellular growth and activity. Although the fatty acid composition delivered to the fetus is largely determined by maternal circulating levels, the placenta preferentially transfers physiologically important long-chain polyunsaturated fatty acids (LC-PUFAs), particularly omega-3 (n-3) PUFAs. Maternal dietary supplementation with n-3 PUFAs during pregnancy has been shown to increase gestation length, enhance fetal growth, and reduce the risk of pregnancy complications, although the precise mechanisms governing these effects remain uncertain. Omega-3 PUFAs are involved in several physiological pathways which could account for these effects, including anti-inflammatory, pro-resolving, and anti-oxidative pathways. Recent studies have shown that maternal dietary n-3 PUFA supplementation during rat pregnancy can reduce placental oxidative damage and increase placental levels of pro-resolving mediators, effects associated with enhanced fetal and placental growth. Because several placental disorders, such as intrauterine growth restriction, preeclampsia, and gestational diabetes mellitus, are associated with heightened placental inflammation and oxidative stress, there is considerable interest in the potential for dietary n-3 PUFAs as a therapeutic intervention for these disorders. In this study, we review the impact of dietary n-3 PUFAs on placental function, with particular focus on placental inflammation, inflammatory resolution, and oxidative stress.

  11. Maternal dietary omega-3 fatty acids and placental function.

    PubMed

    Jones, Megan L; Mark, Peter J; Waddell, Brendan J

    2014-05-01

    The developing fetus requires substantial amounts of fatty acids to support rapid cellular growth and activity. Although the fatty acid composition delivered to the fetus is largely determined by maternal circulating levels, the placenta preferentially transfers physiologically important long-chain polyunsaturated fatty acids (LC-PUFAs), particularly omega-3 (n-3) PUFAs. Maternal dietary supplementation with n-3 PUFAs during pregnancy has been shown to increase gestation length, enhance fetal growth, and reduce the risk of pregnancy complications, although the precise mechanisms governing these effects remain uncertain. Omega-3 PUFAs are involved in several physiological pathways which could account for these effects, including anti-inflammatory, pro-resolving, and anti-oxidative pathways. Recent studies have shown that maternal dietary n-3 PUFA supplementation during rat pregnancy can reduce placental oxidative damage and increase placental levels of pro-resolving mediators, effects associated with enhanced fetal and placental growth. Because several placental disorders, such as intrauterine growth restriction, preeclampsia, and gestational diabetes mellitus, are associated with heightened placental inflammation and oxidative stress, there is considerable interest in the potential for dietary n-3 PUFAs as a therapeutic intervention for these disorders. In this study, we review the impact of dietary n-3 PUFAs on placental function, with particular focus on placental inflammation, inflammatory resolution, and oxidative stress. PMID:24451224

  12. Early Dexamethasone Treatment Induces Placental Apoptosis in Sheep

    PubMed Central

    Meng, Wenbin; Shang, Hongkai; Li, Shaofu; Sloboda, Deborah M.; Ehrlich, Loreen; Lange, Karolin; Xu, Huaisheng; Henrich, Wolfgang; Dudenhausen, Joachim W.; Plagemann, Andreas; Newnham, John P.; Challis, John R. G.

    2015-01-01

    Glucocorticoid treatment given in late pregnancy in sheep resulted in altered placental development and function. An imbalance of placental survival and apoptotic factors resulting in an increased rate of apoptosis may be involved. We have now investigated the effects of dexamethasone (DEX) in early pregnancy on binucleate cells (BNCs), placental apoptosis, and fetal sex as a determinant of these responses. Pregnant ewes carrying singleton fetuses (n = 105) were randomized to control (n = 56, 2 mL saline/ewe) or DEX treatment (n = 49, intramuscular injections of 0.14 mg/kg ewe weight per 12 hours over 48 hours) at 40 to 41 days of gestation (dG). Placentomes were collected at 50, 100, 125, and 140 dG. At 100 dG, DEX in females reduced BNC numbers, placental antiapoptotic (proliferating cell nuclear antigen), and increased proapoptotic factors (Bax, p53), associated with a temporarily decrease in fetal growth. At 125 dG, BNC numbers and apoptotic markers were restored to normal. In males, ovine placental lactogen-protein levels after DEX were increased at 50 dG, but at 100 and 140 dG significantly decreased compared to controls. In contrast to females, these changes were independent of altered BNC numbers or apoptotic markers. Early DEX was associated with sex-specific, transient alterations in BNC numbers, which may contribute to changes in placental and fetal development. Furthermore, in females, altered placental apoptosis markers may be involved. PMID:25063551

  13. Cytochrome P-450 revealed: the effect of the respiratory cytochromes on the spectrum of bacterial cytochrome P-450.

    PubMed

    Stevenson, P M; Ruettinger, R T; Fulco, A J

    1983-05-16

    Soluble extracts of Bacillus megaterium ATCC 14581 prepared by centrifuging a sonicated cell suspension at 40,000 xg for 30 min apparently contained no cytochrome P-450 unless the culture had been grown in the presence of an inducer: a reduced+CO minus reduced spectrum was used to measure cytochrome P-450 concentration. When the 40,000 xg supernatants from the uninduced cultures were recentrifuged at 105,000 xg the respiratory cytochromes, including one like cytochrome a1, were sedimented, and cytochrome P-450 was observed to be 100 nM or 30 +/- 9 p mol cytochrome P-450/mg protein (n=9). Measurements of cytochrome P-450 in cultures induced with phenobarbital were always higher after ultracentrifugation. There was soluble cytochrome o in all extracts. When cytochrome a1 was present a deep trough at 441 nm developed in the reduced +CO minus reduced difference spectrum of the 40,000 xg supernatant of both the uninduced and the induced cultures. The 40,000 xg supernatant obtained after lysing protoplasts of B. megaterium did not contain cytochrome a1 and always gave a good measure of cytochrome P-450. PMID:6405752

  14. Inflammation and increased aromatase expression occur in the breast tissue of obese women with breast cancer

    PubMed Central

    Morris, Patrick G.; Hudis, Clifford A.; Giri, Dilip; Morrow, Monica; Falcone, Domenick J.; Zhou, Xi Kathy; Du, Baoheng; Brogi, Edi; Crawford, Carolyn B.; Kopelovich, Levy; Subbaramaiah, Kotha; Dannenberg, Andrew J.

    2011-01-01

    Obesity is a risk factor for the development of hormone receptor-positive breast cancer in postmenopausal women and has been associated with an increased risk of recurrence and reduced survival. In humans, obesity causes subclinical inflammation in visceral and subcutaneous adipose tissue, characterized by necrotic adipocytes surrounded by macrophages forming crown-like structures (CLS). Recently, we found increased numbers of CLS, activation of the NF-κB transcription factor and elevated aromatase levels and activity in the mammary glands of obese mice. These preclinical findings raised the possibility that the obesity→inflammation axis is important for the development and progression of breast cancer. Here, our main objective was to determine if the findings in mouse models of obesity translated to women. Breast tissue was obtained from 30 women who underwent breast surgery. CLS of the breast (CLS-B) were found in nearly 50% (14 of 30) of patient samples. The severity of breast inflammation, defined as the CLS-B index, correlated with both body mass index (P<0.001) and adipocyte size (P=0.01). Increased NF-κB binding activity and elevated aromatase expression and activity were found in the inflamed breast tissue of overweight and obese women. Collectively, our results suggest that the obesity→inflammation→aromatase axis is present in the breast tissue of most overweight and obese women. The presence of CLS-B may be a biomarker of increased breast cancer risk or poor prognosis. PMID:21622727

  15. Acute stress differentially affects aromatase activity in specific brain nuclei of adult male and female quail.

    PubMed

    Dickens, Molly J; Cornil, Charlotte A; Balthazart, Jacques

    2011-11-01

    The rapid and temporary suppression of reproductive behavior is often assumed to be an important feature of the adaptive acute stress response. However, how this suppression operates at the mechanistic level is poorly understood. The enzyme aromatase converts testosterone to estradiol in the brain to activate reproductive behavior in male Japanese quail (Coturnix japonica). The discovery of rapid and reversible modification of aromatase activity (AA) provides a potential mechanism for fast, stress-induced changes in behavior. We investigated the effects of acute stress on AA in both sexes by measuring enzyme activity in all aromatase-expressing brain nuclei before, during, and after 30 min of acute restraint stress. We show here that acute stress rapidly alters AA in the male and female brain and that these changes are specific to the brain nuclei and sex of the individual. Specifically, acute stress rapidly (5 min) increased AA in the male medial preoptic nucleus, a region controlling male reproductive behavior; in females, a similar increase was also observed, but it appeared delayed (15 min) and had smaller amplitude. In the ventromedial and tuberal hypothalamus, regions associated with female reproductive behavior, stress induced a quick and sustained decrease in AA in females, but in males, only a slight increase (ventromedial) or no change (tuberal) in AA was observed. Effects of acute stress on brain estrogen production, therefore, represent one potential way through which stress affects reproduction.

  16. Synthesis of Triphenylethylene Bisphenols as Aromatase Inhibitors That Also Modulate Estrogen Receptors.

    PubMed

    Lv, Wei; Liu, Jinzhong; Skaar, Todd C; O'Neill, Elizaveta; Yu, Ge; Flockhart, David A; Cushman, Mark

    2016-01-14

    A series of triphenylethylene bisphenol analogues of the selective estrogen receptor modulator (SERM) tamoxifen were synthesized and evaluated for their abilities to inhibit aromatase, bind to estrogen receptor α (ER-α) and estrogen receptor β (ER-β), and antagonize the activity of β-estradiol in MCF-7 human breast cancer cells. The long-range goal has been to create dual aromatase inhibitor (AI)/selective estrogen receptor modulators (SERMs). The hypothesis is that in normal tissue the estrogenic SERM activity of a dual AI/SERM could attenuate the undesired effects stemming from global estrogen depletion caused by the AI activity of a dual AI/SERM, while in breast cancer tissue the antiestrogenic SERM activity of a dual AI/SERM could act synergistically with AI activity to enhance the antiproliferative effect. The potent aromatase inhibitory activities and high ER-α and ER-β binding affinities of several of the resulting analogues, together with the facts that they antagonize β-estradiol in a functional assay in MCF-7 human breast cancer cells and they have no E/Z isomers, support their further development in order to obtain dual AI/SERM agents for breast cancer treatment. PMID:26704594

  17. Developmental programing: impact of testosterone on placental differentiation.

    PubMed

    Beckett, E M; Astapova, O; Steckler, T L; Veiga-Lopez, A; Padmanabhan, V

    2014-08-01

    Gestational testosterone treatment causes maternal hyperinsulinemia, intrauterine growth retardation (IUGR), low birth weight, and adult reproductive and metabolic dysfunctions. Sheep models of IUGR demonstrate placental insufficiency as an underlying cause of IUGR. Placental compromise is probably the cause of fetal growth retardation in gestational testosterone-treated sheep. This study tested whether testosterone excess compromises placental differentiation by its androgenic action and/or via altered insulin sensitivity. A comparative approach of studying gestational testosterone (aromatizable androgen) against dihydrotestosterone (non-aromatizable androgen) or testosterone plus androgen antagonist, flutamide, was used to determine whether the effects of testosterone on placental differentiation were programed by its androgenic actions. Co-treatment of testosterone with the insulin sensitizer, rosiglitazone, was used to establish whether the effects of gestational testosterone on placentome differentiation involved compromised insulin sensitivity. Parallel cohorts of pregnant females were maintained for lambing and the birth weight of their offspring was recorded. Placental studies were conducted on days 65, 90, or 140 of gestation. Results indicated that i) gestational testosterone treatment advances placental differentiation, evident as early as day 65 of gestation, and culminates in low birth weight, ii) placental advancement is facilitated at least in part by androgenic actions of testosterone and is not a function of disrupted insulin homeostasis, and iii) placental advancement, while helping to increase placental efficiency, was insufficient to prevent IUGR and low-birth-weight female offspring. Findings from this study may be of relevance to women with polycystic ovary syndrome, whose reproductive and metabolic phenotype is captured by the gestational testosterone-treated offspring.

  18. Developmental programming: impact of testosterone on placental differentiation

    PubMed Central

    Beckett, EM; Astapova, O; Steckler, TL; Veiga-Lopez, A; Padmanabhan, V

    2014-01-01

    Gestational testosterone (T) treatment causes maternal hyperinsulinemia, intra-uterine growth retardation (IUGR), low birth weight, and adult reproductive and metabolic dysfunctions. Sheep models of IUGR demonstrate placental insufficiency as an underlying cause of IUGR. Placental compromise is likely the cause of fetal growth retardation in gestational T-treated sheep. This study tested if T excess compromises placental differentiation by its androgenic action and/or via altered insulin sensitivity. A comparative approach of studying gestational T (aromatizable androgen) against dihydrotestosterone (DHT; non-aromatizable androgen) or T plus androgen antagonist, flutamide, was used to determine whether the effects of T in placental differentiation were programmed by its androgenic actions. Co-treatment of testosterone with the insulin sensitizer, rosiglitazone, was used to establish whether the effects of gestational T on placentome differentiation involved compromised insulin sensitivity. Parallel cohorts of pregnant females were maintained for lambing and the birth weight of their offspring was recorded. Placental studies were conducted on days 65, 90, or 140 of gestation. Results indicated that 1) gestational T treatment advances placental differentiation, evident as early as day 65 of gestation, and culminates in low birth weight, 2) placental advancement is facilitated at least in part by androgenic actions of T and is not a function of disrupted insulin homeostasis, and 3) placental advancement, while helping to increase placental efficiency, was insufficient to prevent IUGR and low birth weight female offspring. Findings from this study may be of relevance to women with PCOS, whose reproductive and metabolic phenotype is captured by the gestational T-treated offspring. PMID:24840528

  19. Placental exosomes in normal and complicated pregnancy.

    PubMed

    Mitchell, Murray D; Peiris, Hassendrini N; Kobayashi, Miharu; Koh, Yong Q; Duncombe, Gregory; Illanes, Sebastian E; Rice, Gregory E; Salomon, Carlos

    2015-10-01

    While there is considerable contemporary interest in elucidating the role of placenta-derived extracellular vesicles in normal and complicated pregnancies and their utility as biomarkers and therapeutic interventions, progress in the field is hindered by a lack of standardized extracellular vesicle taxonomy and isolation protocols. The term "extracellular vesicle" is nonspecific and refers to all membrane-bound vesicles from nanometer to micrometer diameters and of different biogenic origins. To meaningfully ascribe biological function and/or diagnostic and therapeutic utility to extracellular vesicles, and in particular exosomes, greater specificity and vesicle characterization is required. The current literature relating to exosome biology must be interpreted in this context. Exosomes are a subtype of extracellular vesicle that are specifically defined by an endosomal biogenesis and particle size (40-120 nm) and density (1.13-1.19 g/mL(-1)). Exosomes are specifically package with signaling molecules (including protein, messenger RNA, microRNA, and noncoding RNA) and are released by exocytosis into biofluid compartments. Exosomes regulate the activity of both proximal and distal target cells, including translational activity, angiogenesis, proliferation, metabolism, and apoptosis. As such, exosomal signaling represents an integral pathway mediating intercellular communication. During pregnancy, the placenta releases exosomes into the maternal circulation from as early as 6 weeks of gestation. Release is regulated by factors that include both oxygen tension and glucose concentration and correlates with placental mass and perfusion. The concentration of placenta-derived exosomes in maternal plasma increases progressively during gestation. Exosomes isolated from maternal plasma are bioactive in vitro and are incorporated into target cells by endocytosis. While the functional significance of placental exosomes in pregnancy remains to be fully elucidated, available

  20. Early placental insulin-like protein (INSL4 or EPIL) in placental and fetal membrane growth.

    PubMed

    Millar, Lynnae; Streiner, Nicole; Webster, Lisa; Yamamoto, Sandra; Okabe, Rachel; Kawamata, Tasha; Shimoda, Jacqueline; Büllesbach, Erika; Schwabe, Christian; Bryant-Greenwood, Gillian

    2005-10-01

    Early placental insulin-like protein (INSL4 or EPIL) is a member of the insulin superfamily of hormones, which is highly expressed in the placenta. We have confirmed this at term and shown it to be expressed by the maternal decidua. Although an abundance of locally acting growth factors are produced within the uterus during pregnancy, we hypothesized that INSL4 plays an important role in fetal and placental growth. We have demonstrated with cell lines and primary cells that it has a growth-inhibitory effect by causing apoptosis and loss of cell viability. We used primary amniotic epithelial cells for flow cytometry to show that INSL4 caused apoptosis, which was dose-related and significant (P < 0.05) at 50 ng/ml. This was confirmed by measurement of the nuclear matrix protein in the media. In comparison, relaxin treatment (up to 200 ng/ml) had no effect on apoptosis. The addition of INSL4 (3-30 ng/ml) also caused a loss of cell viability, although it had no effect on the numbers of cells at different phases of the cell cycle. Placental apoptosis is an important process in both normal placental development and in fetal growth restriction. Therefore, an in vivo clinical correlate was sought in fraternal twins exhibiting discordant growth. Expression of the INSL4 gene was doubled in the placenta of the growth-restricted twin compared to the normally grown sibling, suggesting that it may be linked to a higher level of apoptosis and loss of cell viability and, therefore, that it may contribute to fetal growth restriction.

  1. Tissue-specific expression of the bovine aromatase-encoding gene uses multiple transcriptional start sites and alternative first exons.

    PubMed

    Fürbass, R; Kalbe, C; Vanselow, J

    1997-07-01

    Here we report on the genomic structure of the bovine aromatase cytochrome P450-encoding gene (Cyp19) and its tissue-specific transcript variants. The gene comprises at least 14 exons (1.1, 1.2a, 1.2b, 1.3,1.4, and 2-10) spanning more than 56 kilobases of genomic DNA. The coding area is confined to exons 2-10. Transcriptional start sites of Cyp19 were examined in granulosa cells, placenta, testis, adrenal gland, and brain, employing 5'-RACE (rapid amplification of complementary DNA ends) and primer extension. The analysis of 5'-RACE clones revealed six Cyp19 transcript variants that were different within their 5'-untranslated regions (5'-UTR). Yet, the coding region was identical in all clones. Although two of these 5'-UTR (the first 152 nucleotides of exon 2 and exon 1.4) are conserved among different species, four others (exons 1.1, 1.2a, 1.2b, and 1.3) did not show sequence homology to any other species. Transcription from exons 1.1 and 2 starts at several adjacent sites. In granulosa cells and placenta, but not in brain, a fraction of transcripts starting with exon 1.2a contains an additional untranslated exon, 1.2b, due to alternative splicing. Transcript variants comprising exon 1.1, 1.2a, 1.2b, or 1.3 were mainly found in the placenta, those with the 5'-UTR of exon 2 were predominant in granulosa cells, and transcripts with exon 1.4 prevailed in the brain. Estimates of Cyp19 transcript concentrations in six different tissues revealed high levels in granulosa cells and placenta, intermediate levels in testis and brain, and low levels in adrenal gland and liver. Our experiments demonstrate that six transcript variants of the bovine Cyp19 gene, including 9-11 exons, are expressed with tissue-specific preferences. These transcripts are presumably generated using five different promoter regions and tissue-specific alternative splicing. PMID:9202222

  2. [How to stimulate the placental function (author's transl)].

    PubMed

    Fanard, A; Picazo, J J

    1976-01-01

    Imminent abortion, habitual abortion and threatened premature labor, all constitute difficult clinical problems. Those cases require on every occasion a diagnosis as acurate as possible, and unfortunately our present methods of biochemical determinations only represent a means to evaluate placental function. On those cases where a faulty placental function is detected thru the tests presently available, the authors recommend the utilization of a placentotropic substance, Gestanon, that is capable to stimulate and normalize the placental function, a is demostrated by the statistical results published in the international medical bibliography.

  3. Associations between intrapartum death and piglet, placental, and umbilical characteristics.

    PubMed

    Rootwelt, V; Reksen, O; Farstad, W; Framstad, T

    2012-12-01

    Intrapartum death in multiparous gestations in sows (Sus scrofa) is often caused by hypoxia. There is little information in the literature on the assessment of the placenta in relation to intrapartum death in piglets. The aim of this study was to evaluate the impact of the placental area and weight upon piglet birth characteristics and intrapartum death. Litters from 26 Landrace-Yorkshire sows were monitored during farrowing and the status of each piglet was recorded, including blood parameters of piglets and their umbilical veins. Of 413 piglets born, 6.5% were stillborn. Blood concentrations of glucose, lactate, and CO(2) partial pressure were increased in the stillborn piglets (P < 0.05) and corresponding umbilical veins (P < 0.01) vs. live-born piglets, whereas pH and base excess were decreased (P < 0.001). Time from onset of parturition until birth was increased for piglets born dead vs. live (P < 0.001). Mean birth weight for piglets born dead was not different from live-born piglets (P = 0.631), whereas mean body mass index was reduced (P < 0.001). Mean placental area and placental weight belonging to stillborn piglets were not different from live-born piglets (P = 0.662 and P = 0.253, respectively). Blood concentrations of lactate, hemoglobin, and hematocrit recorded in all piglets pooled were associated with placental area (P < 0.05), but not with placental weight (P > 0.2). Piglet BW was positively correlated with placental area and placental weight (P < 0.001). The risk of being born dead increased with increasing birth order group, and broken umbilical cords explained 71% of the stillbirths (P = 0.001). We conclude that placental area and placental weight are both positively associated with piglet birth weight, but not with the probability of being born dead. Placental area was a better predictor of piglet vitality than placental weight. Because umbilical cord rupture and prolonged birth time were associated with being born dead, umbilical cord rupture

  4. Distribution of CA 125 in placental tissues.

    PubMed

    Fuith, L C; Müller-Holzner, E; Marth, C; Perkmann, E; Zeimet, A; Daxenbichler, G

    1989-01-01

    The presence of the tumor marker CA 125 was studied in different compartments of the human placenta. Levels of CA 125 in the cytosol of chorionic villi ranged from 27-17100 U/g (median 560 U/g). In the placental amnion and chorion concentrations ranged from 175-29000 U/g, median 1060 U/g and were not statistically different. In the umbilical cord values were significantly lower (range 44-7600 U/g; median 180 U/g). Maternal serum probes were above the upper limit of normal in all cases (range 48-500 U/ml; median 131 U/ml). Immunohistochemistry detected CA 125 exclusively within the amniotic cells of the placenta and the umbilical cord. This might be because CA 125 fixes more to insoluble structures in the amnion or because of contamination of chorionic villi with the underlying decidua.

  5. Placental copper transport in the brindled mouse

    SciTech Connect

    Garnica, A.; Bates, J.

    1986-03-01

    Pregnant brindled (brin) mice were injected at 16 or 19 days gestation with 2 doses of CuCl/sub 2/ 6 mcg/g/dose, separated by 12 h, and sacrificed 6 h after the second. The copper conc. in placenta (P) and kidneys (K) of uninjected (UI) brin mice were higher than in UI controls, while conc. in liver (L) and fetal carcass (F) were lower. After injection (I), placental copper conc. increased while the carcass conc. remained unchanged. Brin mouse is a model for the human inborn error of copper metabolism, Menkes syndrome, which is characterized by signs of copper deficiency. These data indicate that metabolism of copper in brin fetus is abnormal, but depressed fetal copper levels cannot be corrected by acute copper dosing because of the sequestration of copper in placenta.

  6. Testosterone-induced adult neurosphere growth is mediated by sexually-dimorphic aromatase expression

    PubMed Central

    Ransome, Mark I.; Boon, Wah Chin

    2015-01-01

    We derived adult neural stem/progenitor cells (NSPCs) from the sub-ventricular zone of male and female mice to examine direct responses to principal sex hormones. In the presence of epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF2) NSPCs of both sexes expressed nestin and sox2, and could be maintained as neurospheres without addition of any sex hormones. The reverse was not observed; neither testosterone (T), 17β-estradiol (E2) nor progesterone (P4) was able to support neurosphere growth in the absence of EGF and FGF2. Ten nanomolar T, E2 or P4 induced nestin(+) cell proliferation within 20 min and enhanced neurosphere growth over 7 days irrespective of sex, which was abolished by Erk inhibition with 20 μM U0126. Maintaining neurospheres with each sex hormone did not affect subsequent neuronal differentiation. However, 10 nM T, E2 or P4 added during differentiation increased βIII tubulin(+) neuron production with E2 being more potent compared to T and P4 in both sexes. Androgen receptor (AR) inhibition with 20 μM flutamide but not aromatase inhibition with 10 μM letrozole reduced basal and T-induced neurosphere growth in females, while only concurrent inhibition of AR and aromatase produced the same effect in males. This sex-specific effect was supported by higher aromatase expression in male neurospheres compared to females measured by Western blot and green fluorescent protein (GFP) reporter. Ten micromolar menadione induced oxidative stress, impaired neurosphere growth and up-regulated aromatase expression in both sexes. However, under oxidative stress letrozole significantly exacerbated impaired neurosphere growth in males only. While both E2 and T could prevent oxidative stress-induced growth reduction in both sexes, the effects of T were dependent on innate aromatase activity. We show for the first time that intrinsic androgen and estrogen signaling may impact the capacity of NSPCs to produce neural progenitors under pathological

  7. Seven placental transcripts characterize HELLP-syndrome.

    PubMed

    Buimer, M; Keijser, R; Jebbink, J M; Wehkamp, D; van Kampen, A H C; Boer, K; van der Post, J A M; Ris-Stalpers, C

    2008-05-01

    The human placenta is prerequisite for the development of gestational hypertensive diseases like early-onset preeclampsia (PE) and Hemolysis, Elevated Liver enzymes and Low platelets (HELLP) syndrome. Both syndromes are associated with extensive maternal and perinatal mortality, and morbidity with life long consequences. We aimed to investigate differences in gene expression between placental tissue obtained from normotensive pregnant women and women with PE and HELLP syndrome. Firstly, comparison of Serial Analysis of Gene Expression profiles of 28 weeks' control placenta (available after idiopathic premature delivery) to a HELLP/PE placenta matched for gestational age identified 404 differentially expressed transcripts. Secondly, using sqPCR, the expression levels of 37 of these transcripts were analyzed in placentas of 36 pregnant women, 22 with preeclampsia and HELLP syndrome. Thirdly, nearest centroid classification determined the HELLP specific molecular signature consisting of the upregulated expression of genes encoding the vascular endothelial growth factor receptor (FLT1), leptin (LEP), pappalysin 2 (PAPPA2), and WW domain containing transcription regulator 1 (WWTR1) combined with down regulated expression of the genes encoding cadherin-associated protein (CTNNAL), glutathione S-transferase pi (GSTP1) and calgranulin A (S100A8). This set discriminates HELLP placenta from control and PE placenta with a 24% misclassification rate (95% CI 8.3-41.9%), independent from known risk factors like parity and ethnicity. The transcripts involved correspond to diverse molecular pathways, exemplifying the multigenic molecular basis of the disorder. This distinct placental molecular signature suggests that HELLP is not a PE variant but a separate disease entity. Our data may prove fundamental for the further molecular analysis of PE and HELLP syndrome.

  8. The new framework for understanding placental mammal evolution.

    PubMed

    Asher, Robert J; Bennett, Nigel; Lehmann, Thomas

    2009-08-01

    An unprecedented level of confidence has recently crystallized around a new hypothesis of how living placental mammals share a pattern of common descent. The major groups are afrotheres (e.g., aardvarks, elephants), xenarthrans (e.g., anteaters, sloths), laurasiatheres (e.g., horses, shrews), and euarchontoglires (e.g., humans, rodents). Compared with previous hypotheses this tree is remarkably stable; however, some uncertainty persists about the location of the placental root, and (for example) the position of bats within laurasiatheres, of sea cows and aardvarks within afrotheres, and of dermopterans within euarchontoglires. A variety of names for sub-clades within the new placental mammal tree have been proposed, not all of which follow conventions regarding priority and stability. More importantly, the new phylogenetic framework enables the formulation of new hypotheses and testing thereof, for example regarding the possible developmental dichotomy that seems to distinguish members of the newly identified southern and northern radiations of living placental mammals. PMID:19582725

  9. Cytochromes P450 in Nanodiscs

    PubMed Central

    Denisov, Ilia G.; Sligar, Stephen G.

    2010-01-01

    Nanodiscs have proven to be a versatile tool for the study all types of membrane proteins, including receptors, transporters, enzymes and viral antigens. The self-assembled Nanodisc system provides a robust and common means for rendering these targets soluble in aqueous media while providing a native like bilayer environment that maintains functional activity. This system has thus provided a means for studying the extensive collection of membrane bound cytochromes P450 with the same biochemical and biophysical tools that have been previously limited to use with the soluble P450s. These include a plethora of spectroscopic, kinetic and surface based methods. Significant improvements in homogeneity and stability of these preparations open new possibilities for detailed analysis of equilibrium and steady-state kinetic characteristics of catalytic mechanisms of human cytochromes P450 involved in xenobiotic metabolism and in steroid biosynthesis. The experimental methods developed for physico-chemical and functional studies of membrane cytochromes P450 incorporated in Nanodiscs allow for more detailed understanding of the scientific questions along the lines pioneered by Professor Klaus Ruckpaul and his array of colleagues and collaborators. PMID:20685623

  10. Effect of bee venom on aromatase expression and activity in leukaemic FLG 29.1 and primary osteoblastic cells.

    PubMed

    Kim, Kap-Sung; Choi, U-Shik; Lee, Seung-Duk; Kim, Kyung-Ho; Chung, Kang-Hyun; Chang, Young-Chae; Park, Kwan-Kyu; Lee, Young-Choon; Kim, Cheorl-Ho

    2005-06-01

    The effect of bee venom aqua-acupuncture (BVA) (api-toxin), a traditional immunosuppressive Korean aqua-acupuncture, on the bone function in human osteoblastic cells was studied. To provide insights into the effect of BVA on aromatase activity in bone-derived cells, we examined the human leukaemic cell line FLG 29.1, which is induced to differentiate toward the osteoclastic phenotype by TPA and TGF-beta1, and the primary first-passage osteoblastic cells (hOB). Southern blot of RT-PCR products with a 32P-labeled cDNA probe for the human aromatase demonstrated that FLG 29.1 and hOB cells express aromatase mRNA. Gene expression and enzyme activity were stimulated in a time-dependent fashion by 5.0 microl/ml BV and by either 1-50 nM TPA or 0.01-0.5 ng/ml TGF-beta1, with maximal responses after 2-3 h exposure. After 24 h incubation of the cells in the absence of these stimuli the aromatase mRNA and the protein were barely detectable. These findings demonstrate that cells of the osteoclastic lineage synthesize aromatase in vitro by the local cytokine of TGF-beta1 and BVA. These can offer an explanation for the lack of development of osteoarthritis in BVA-treated patients.

  11. Multiscale modelling of the feto–placental vasculature

    PubMed Central

    Clark, A. R.; Lin, M.; Tawhai, M.; Saghian, R.; James, J. L.

    2015-01-01

    The placenta provides all the nutrients required for the fetus through pregnancy. It develops dynamically, and, to avoid rejection of the fetus, there is no mixing of fetal and maternal blood; rather, the branched placental villi ‘bathe’ in blood supplied from the uterine arteries. Within the villi, the feto–placental vasculature also develops a complex branching structure in order to maximize exchange between the placental and maternal circulations. To understand the development of the placenta, we must translate functional information across spatial scales including the interaction between macro- and micro-scale haemodynamics and account for the effects of a dynamically and rapidly changing structure through the time course of pregnancy. Here, we present steps towards an anatomically based and multiscale approach to modelling the feto–placental circulation. We assess the effect of the location of cord insertion on feto–placental blood flow resistance and flow heterogeneity and show that, although cord insertion does not appear to directly influence feto–placental resistance, the heterogeneity of flow in the placenta is predicted to increase from a 19.4% coefficient of variation with central cord insertion to 23.3% when the cord is inserted 2 cm from the edge of the placenta. Model geometries with spheroidal and ellipsoidal shapes, but the same volume, showed no significant differences in flow resistance or heterogeneity, implying that normal asymmetry in shape does not affect placental efficiency. However, the size and number of small capillary vessels is predicted to have a large effect on feto–placental resistance and flow heterogeneity. Using this new model as an example, we highlight the importance of taking an integrated multi-disciplinary and multiscale approach to understand development of the placenta. PMID:25844150

  12. Patterns of ossification in southern versus northern placental mammals.

    PubMed

    Hautier, Lionel; Bennett, Nigel C; Viljoen, Hermien; Howard, Lauren; Milinkovitch, Michel C; Tzika, Athanasia C; Goswami, Anjali; Asher, Robert J

    2013-07-01

    Consensus on placental mammal phylogeny is fairly recent compared to that for vertebrates as a whole. A stable phylogenetic hypothesis enables investigation into the possibility that placental clades differ from one another in terms of their development. Here, we focus on the sequence of skeletal ossification as a possible source of developmental distinctiveness in "northern" (Laurasiatheria and Euarchontoglires) versus "southern" (Afrotheria and Xenarthra) placental clades. We contribute data on cranial and postcranial ossification events during growth in Afrotheria, including elephants, hyraxes, golden moles, tenrecs, sengis, and aardvarks. We use three different techniques to quantify sequence heterochrony: continuous method, sequence-ANOVA (analysis of variance) and event-paring/Parsimov. We show that afrotherians significantly differ from other placentals by an early ossification of the orbitosphenoid and caudal vertebrae. Our analysis also suggests that both southern placental groups show a greater degree of developmental variability; however, they rarely seem to vary in the same direction, especially regarding the shifts that differ statistically. The latter observation is inconsistent with the Atlantogenata hypothesis in which afrotherians are considered as the sister clade of xenarthrans. Interestingly, ancestral nodes for Laurasiatheria and Euarchontoglires show very similar trends and our results suggest that developmental homogeneity in some ossification sequences may be restricted to northern placental mammals (Boreoeutheria).

  13. Feto-placental adaptations to maternal obesity in the baboon

    PubMed Central

    Farley, Darren; Tejero, Maria E.; Comuzzie, Anthony G.; Higgins, Paul B.; Cox, Laura; Werner, Sherry L.; Jenkins, Susan L.; Li, Cun.; Choi, Jaehyek; Dick, Edward J.; Hubbard, Gene B.; Frost, Patrice; Dudley, Donald D.; Ballesteros, Brandon; Wu, Guoyao; Nathanielsz, Peter W.; Schlabritz-Loutsevitch, Natalia E.

    2010-01-01

    Maternal obesity is present in 20–34% of pregnant women and has been associated with both intrauterine growth restriction and large-for-gestational age fetuses. While fetal and placental functions have been extensively studied in the baboon, no data are available on the effect of maternal obesity on placental structure and function in this species. We hypothesize that maternal obesity in the baboon is associated with a maternal inflammatory state and induces structural and functional changes in the placenta. The major findings of this study were 1) decreased placental syncytiotrophoblast amplification factor, intact syncytiotrophoblast endoplasmic reticulum structure and decreased system A placental amino acid transport in obese animals; 2) fetal serum amino acid composition and mononuclear cells (PBMC) transcriptome were different in fetuses from obese compared with non-obese animals 3) maternal obesity in humans and baboons is similar in regard of increased placental and adipose tissue macrophage infiltration, increased CD14 expression in maternal PBMC and maternal hyperleptinemia. In summary, these data demonstrate that in obese baboons in the absence of increased fetal weight, placental and fetal phenotype are consistent with those described for large- for-gestational age human fetuses. PMID:19632719

  14. Relationship between placental traits and maternal intrinsic factors in sheep.

    PubMed

    Ocak, S; Ogun, S; Onder, H

    2013-06-01

    The relationship between maternal intrinsic factors and placental traits was investigated on three Southern Mediterranean breed of sheep; Cukurova Assaf (CA), Cukurova (C) and Cukurova Meat Sheep (CMS). The effect of parity and birth type were also considered in the study as a potential influencing factor. Our hypothesis was to show that while differences in placental traits between breed, parity and birth type affected lamb condition and survivability, its correlation to maternal intrinsic behavioral factors may also be a strong indicator. The study found breed related differences of maternal behavioral factors and also showed significant correlation of these behavioral patterns to various placental traits. It confirmed earlier findings that parity played a major role in the refinement of these behavioral patterns. Significant differences in birth weight (P<0.05), placental weight (P<0.05), number of cotyledons (P<0.01) and cotyledon length (P<0.05) was seen between breeds. Cotyledon weight (P<0.05), width (P<0.01) and length (P<0.05) were found to differ by parity. Breed and parity interaction significantly influenced cotyledon quantity. While we detected breed specific differences in relation to maternal intrinsic factors we also noticed significant variance within breeds to these behavioral patterns when linked to placental traits. Further study is required on the correlation between placental traits and postnatal behavior on not just the ewes but also on their lambs. This could have a significant bearing on how producers manage and maximize lamb survivability.

  15. Association between PAPP-A and placental thickness

    PubMed Central

    Mesdaghi-nia, Elaheh; Behrashi, Mitra; Saeidi, Arezoo; Abedzadeh Kalahroodi, Masoomeh; Sehat, Mojtaba

    2016-01-01

    Background: Measuring of maternal serum pregnancy-associated plasma protein-A (PAPP-A) in first trimester can be a way for early detection of adverse prenatal outcome due to faulty placenta. Objective: The aim was to Determination of association between placental thickness in second trimester with low level of PAPP-A in first trimester. Materials and Methods: In this cohort study, serum PAPP-A of 187 pregnant women was measured in the first trimester of pregnancy. Patients who had PAPP-A ≤0.8 MOM were in exposed and others who had PAPP-A >0.8 defined as unexposed group. The criteria of placental thickness in ultrasound study was thickness of 4 cm or more than 50% of placental length. Results: Of 187 patients, 87 patients had PAPP-A >0.8 and 93 patients had PAPP-A ≤0.8. Women with low levels of PAPP-A in the first trimester, had an increased incidence placental thickness of 34.4%, whereas another group had about 15% (p=0.002). Also, PAPP-A levels had acceptable sensitivity and specificity for placental thickness detection (71.1% and 54.8%, respectively. Conclusion: Our study showed that serum level of PAPP-A generally was low (≤0.8) in women with a thick placenta (>4 cm or >50% of placental length). The first trimester of pregnancy measurement of PAPP-A will be more predictable for healthy placenta. PMID:27525326

  16. Metabolism of bupropion by baboon hepatic and placental microsomes

    PubMed Central

    Wang, Xiaoming; Abdelrahman, Doaa R.; Fokina, Valentina M.; Hankins, Gary D.V.; Ahmed, Mahmoud S.; Nanovskaya, Tatiana N.

    2011-01-01

    The aim of this investigation was to determine the biotransformation of bupropion by baboon hepatic and placental microsomes, identify the enzyme(s) catalyzing the reaction(s) and determine its kinetics. Bupropion was metabolized by baboon hepatic and placental microsomes to hydroxybupropion (OH-BUP), threo- (TB) and erythrohydrobupropion (EB). OH-bupropion was the major metabolite formed by hepatic microsomes (Km 36 ± 6 µM, Vmax 258 ± 32 pmol mg protein−1 min−1), however the formation of OH-BUP by placental microsomes was below the limit of quantification. The apparent Km values of bupropion for the formation of TB and EB by hepatic and placental microsomes were similar. The selective inhibitors of CYP2B6 (ticlopidine and phencyclidine) and monoclonal antibodies raised against human CYP2B6 isozyme caused 80% inhibition of OH-BUP formation by baboon hepatic microsomes. The chemical inhibitors of aldo-keto reductases (flufenamic acid), carbonyl reductases (menadione), and 11β-hydroxysteroid dehydrogenases (18β-glycyrrhetinic acid) significantly decreased the formation of TB and EB by hepatic and placental microsomes. Data indicate that CYP2B of baboon hepatic microsomes is responsible for biotransformation of bupropion to OH-BUP, while hepatic and placental short chain dehydrogenases/reductases and to a lesser extent aldo-keto reductases are responsible for the reduction of bupropion to TB and EB. PMID:21570381

  17. Brain aromatase (Cyp19A2) and estrogen receptors, in larvae and adult pejerrey fish Odontesthes bonariensis: Neuroanatomical and functional relations

    USGS Publications Warehouse

    Strobl-Mazzulla, P. H.; Lethimonier, C.; Gueguen, M.M.; Karube, M.; Fernandino, J.I.; Yoshizaki, G.; Patino, R.; Strussmann, C.A.; Kah, O.; Somoza, G.M.

    2008-01-01

    Although estrogens exert many functions on vertebrate brains, there is little information on the relationship between brain aromatase and estrogen receptors. Here, we report the cloning and characterization of two estrogen receptors, ?? and ??, in pejerrey. Both receptors' mRNAs largely overlap and were predominantly expressed in the brain, pituitary, liver, and gonads. Also brain aromatase and estrogen receptors were up-regulated in the brain of estradiol-treated males. In situ hybridization was performed to study in more detail, the distribution of the two receptors in comparison with brain aromatase mRNA in the brain of adult pejerrey. The estrogen receptors' mRNAs exhibited distinct but partially overlapping patterns of expression in the preoptic area and the mediobasal hypothalamus, as well as in the pituitary gland. Moreover, the estrogen receptor ??, but not ??, were found to be expressed in cells lining the preoptic recess, similarly as observed for brain aromatase. Finally, it was shown that the onset expression of brain aromatase and both estrogen receptors in the head of larvae preceded the morphological differentiation of the gonads. Because pejerrey sex differentiation is strongly influenced by temperature, brain aromatase expression was measured during the temperature-sensitive window and was found to be significantly higher at male-promoting temperature. Taken together these results suggest close neuroanatomical and functional relationships between brain aromatase and estrogen receptors, probably involved in the sexual differentiation of the brain and raising interesting questions on the origin (central or peripheral) of the brain aromatase substrate. ?? 2008 Elsevier Inc.

  18. Aromatase Activity in Sheepshead Minnow (Cyprinodon variegatus), Exposed to 17B-Trenbolone or 17B-estradiol in a Tier II Two-Generation Test

    EPA Science Inventory

    We tested the hypothesis that endocrine disrupting chemicals (EDCs) that alter fish reproduction will also modulate activity of the steroidogenic enzyme aromatase. There are two distinct isozymes of aromatase that have been characterized in fish, one predominating in brains and a...

  19. Vectorially oriented monolayers of the cytochrome c/cytochrome oxidase bimolecular complex.

    PubMed Central

    Edwards, A M; Blasie, J K; Bean, J C

    1998-01-01

    Vectorially oriented monolayers of yeast cytochrome c and its bimolecular complex with bovine heart cytochrome c oxidase have been formed by self-assembly from solution. Both quartz and Ge/Si multilayer substrates were chemical vapor deposited with an amine-terminated alkylsiloxane monolayer that was then reacted with a hetero-bifunctional cross-linking reagent, and the resulting maleimide endgroup surface then provided for covalent interactions with the naturally occurring single surface cysteine 102 of the yeast cytochrome c. The bimolecular complex was formed by further incubating these cytochrome c monolayers in detergent-solubilized cytochrome oxidase. The sequential formation of such monolayers and the vectorially oriented nature of the cytochrome oxidase was studied via meridional x-ray diffraction, which directly provided electron density profiles of the protein(s) along the axis normal to the substrate plane. The nature of these profiles is consistent with previous work performed on vectorially oriented monolayers of either cytochrome c or cytochrome oxidase alone. Furthermore, optical spectroscopy has indicated that the rate of binding of cytochrome oxidase to the cytochrome c monolayer is an order of magnitude faster than the binding of cytochrome oxidase to an amine-terminated surface that was meant to mimic the ring of lysine residues around the heme edge of cytochrome c, which are known to be involved in the binding of this protein to cytochrome oxidase. PMID:9512031

  20. Maternal dietary omega-3 fatty acid supplementation reduces placental oxidative stress and increases fetal and placental growth in the rat.

    PubMed

    Jones, Megan L; Mark, Peter J; Mori, Trevor A; Keelan, Jeffrey A; Waddell, Brendan J

    2013-02-01

    Placental oxidative stress plays a key role in the pathophysiology of several placenta-related disorders including intrauterine growth restriction. Oxidative stress occurs when accumulation of reactive oxygen species damages DNA, proteins, and lipids, an outcome normally limited by antioxidant defenses. Dietary supplementation with omega-3 polyunsaturated fatty acids (n-3 PUFAs) may limit oxidative stress by increasing antioxidant capacity, but n-3 PUFAs are also highly susceptible to lipid peroxidation; so n-3 PUFA supplementation is potentially harmful. Here we examined the effect of n-3 PUFAs on placental oxidative stress and on placental and fetal growth in the rat. We also investigated whether diet-induced changes in maternal plasma fatty acid profiles are associated with comparable changes in placental and fetal tissues. Rats were fed either standard or high n-3 PUFA diets from Day 1 of pregnancy, and tissues were collected on Day 17 or 22 (term = Day 23). Dietary supplementation with n-3 PUFAs increased fetal (6%) and placental (12%) weights at Day 22, the latter attributable primarily to growth of the labyrinth zone (LZ). Increased LZ weight was accompanied by reduced LZ F(2)-isoprostanes (by 31% and 11% at Days 17 and 22, respectively), a marker of oxidative damage. Maternal plasma PUFA profiles were altered by dietary fatty acid intake and were strongly predictive of corresponding profiles in placental and fetal tissues. Our data indicate that n-3 PUFA supplementation reduces placental oxidative stress and enhances placental and fetal growth. Moreover, fatty acid profiles in the mother, placenta, and fetus are highly dependent on dietary fatty acid intake.

  1. 2011 and 2012 Early Careers Achievement Awards: Placental programming: how the maternal environment can impact placental function.

    PubMed

    Vonnahme, K A; Lemley, C O; Shukla, P; O'Rourke, S T

    2013-06-01

    Proper establishment of the placenta is important for fetal survival; however, placental adaptations to inadequate maternal nutrition or other stressors are imperative for fetal growth to be optimal. The effects of maternal nutritional status and activity level on placental vascular function and uteroplacental blood flows are important to understand as improper placental function leads to reduced growth of the fetus. In environments where fetal growth can be compromised, potential therapeutics may augment placental function and delivery of nutrients to improve offspring performance during postnatal life. Factors that could enhance placental function include supplementation of specific nutrients, such as protein, hormone supplements, such as indolamines, and increased activity levels of the dam. To understand the mechanism of how the maternal environment can impact uterine or umbilical blood flows, assessment of placental vascular reactivity has been studied in several large animal models. As we begin to understand how the maternal environment impacts uterine and umbilical blood flows and other uteroplacental hemodynamic parameters, development of management methods and therapeutics for proper fetal growth can be achieved.

  2. Maternal testosterone and placental function: Effect of electroacupuncture on placental expression of angiogenic markers and fetal growth.

    PubMed

    Fornes, Romina; Hu, Min; Maliqueo, Manuel; Kokosar, Milana; Benrick, Anna; Carr, David; Billig, Håkan; Jansson, Thomas; Manni, Luigi; Stener-Victorin, Elisabet

    2016-09-15

    Women with polycystic ovary syndrome (PCOS) have elevated circulating androgens during pregnancy and are at an increased risk of adverse pregnancy outcomes. Here we tested the hypotheses that maternal androgen excess decrease placental and fetal growth, and placental expression of markers of steroidogenesis, angiogenesis and sympathetic activity, and that acupuncture with low-frequency electrical stimulation prevents these changes. Pregnant rats were exposed to vehicle or testosterone on gestational day (GD)15-19. Low-frequency electroacupuncture (EA) or handling, as a control for the EA procedure, was given to control or testosterone exposed dams on GD16-20. On GD21, blood pressure was measured and maternal blood, fetuses and placentas collected. Placental steroid receptor expression and proteins involved in angiogenic, neurotrophic and adrenergic signaling were analyzed. EA did not affect any variables in control rats except maternal serum corticosterone, which was reduced. EA in testosterone exposed dams compared with controls increased systolic pressure by 30%, decreased circulating norepinephrine and corticosterone, fetal and placental weight and placental VEGFR1 and proNGF protein expression, and increased the VEGFA/VEGFR1 ratio, mature NGF (mNGF) and the mNGF/proNGF ratio. In conclusion, low-frequency EA in control animals did not have any negative influence on any of the studied variables. In contrast, EA in pregnant dams exposed to testosterone increased blood pressure and impaired placental growth and function, leading to decreased fetal growth. PMID:27208621

  3. Currently used pesticides and their mixtures affect the function of sex hormone receptors and aromatase enzyme activity

    SciTech Connect

    Kjeldsen, Lisbeth Stigaard; Ghisari, Mandana; Bonefeld-Jørgensen, Eva Cecilie

    2013-10-15

    The endocrine-disrupting potential of pesticides is of health concern, since they are found ubiquitously in the environment and in food items. We investigated in vitro effects on estrogen receptor (ER) and androgen receptor (AR) transactivity, and aromatase enzyme activity, of the following pesticides: 2-methyl-4-chlorophenoxyacetic acid (MCPA), terbuthylazine, iodosulfuron-methyl-sodium, mesosulfuron-methyl, metsulfuron-methyl, chlormequat chloride, bitertanol, propiconazole, prothioconazole, mancozeb, cypermethrin, tau fluvalinate, malathion and the metabolite ethylene thiourea (ETU). The pesticides were analyzed alone and in selected mixtures. Effects of the pesticides on ER and AR function were assessed in human breast carcinoma MVLN cells and hamster ovary CHO-K1 cells, respectively, using luciferase reporter gene assays. Effects on aromatase enzyme activity were analyzed in human choriocarcinoma JEG-3 cells, employing the classical [{sup 3}H]{sub 2}O method. Five pesticides (terbuthylazine, propiconazole, prothioconazole, cypermethrin and malathion) weakly induced the ER transactivity, and three pesticides (bitertanol, propiconazole and mancozeb) antagonized the AR activity in a concentration-dependent manner. Three pesticides (terbuthylazine, propiconazole and prothioconazole) weakly induced the aromatase activity. In addition, two mixtures, consisting of three pesticides (bitertanol, propiconazole, cypermethrin) and five pesticides (terbuthylazine, bitertanol, propiconazole, cypermethrin, malathion), respectively, induced the ER transactivity and aromatase activity, and additively antagonized the AR transactivity. In conclusion, our data suggest that currently used pesticides possess endocrine-disrupting potential in vitro which can be mediated via ER, AR and aromatase activities. The observed mixture effects emphasize the importance of considering the combined action of pesticides in order to assure proper estimations of related health effect risks

  4. Pomegranate Ellagitannin-Derived Compounds Exhibit Anti-proliferative and Anti-aromatase Activity in Breast Cancer Cells In Vitro

    PubMed Central

    Adams, Lynn S.; Zhang, Yanjun; Seeram, Navindra P.; Heber, David; Chen, Shiuan

    2009-01-01

    Estrogen stimulates the proliferation of breast cancer cells and the growth of estrogen-responsive tumors. The aromatase enzyme, which converts androgen to estrogen, plays a key role in breast carcinogenesis. The pomegranate fruit, a rich source of ellagitannins (ETs), has attracted recent attention due to its anti-cancer and anti-atherosclerotic properties. On consumption, pomegranate ETs hydrolyze, releasing ellagic acid (EA) which is then converted to 3,8-dihydroxy-6H-dibenzo[b,d]pyran-6-one (‘urolithin’) derivatives by gut microflora. The purpose of this study was to investigate the anti-aromatase activity and inhibition of testosterone-induced breast cancer cell proliferation by ellagitannin (ET)-derived compounds isolated from pomegranates. A panel of ten ET-derived compounds including EA, gallagic acid (GA), and urolithins A and B (and their acetylated, methylated and sulfated analogs prepared in our laboratory) were examined for ability to inhibit aromatase activity and testosterone-induced breast cancer cell proliferation. Using a microsomal aromatase assay, we screened the panel of ET-derived compounds and identified six with anti-aromatase activity. Among these, urolithin B (UB) was shown to most effectively inhibit aromatase activity in a live-cell assay. Kinetic analysis of UB demonstrated mixed inhibition, suggesting more than one inhibitory mechanism. Proliferation assays also determined that UB significantly inhibited testosterone-induced MCF-7aro cell proliferation. The remaining test compounds also exhibited anti-proliferative activity, but to a lesser degree than UB. These studies suggest that pomegranate ET-derived compounds have potential for the prevention of estrogen-responsive breast cancers. PMID:20051378

  5. Toremifene – Atamestane; Alone or In Combination: Predictions from the Preclinical Intratumoral Aromatase Model

    PubMed Central

    Sabnis, Gauri J; Macedo, Luciana; Goloubeva, Olga; Schayowitz, Adam; Zhu, Yue; Brodie, Angela

    2011-01-01

    Since most breast cancers occur in post-menopausal women and are hormone dependent, we developed a model system that mimics this situation. In this model, tumors of human estrogen receptor ER positive breast cancer cells stably transfected with aromatase (Ac-1) are grown in immune compromised mice. Using this model we have explored a number of therapeutic strategies to maximize the antitumor efficacy of antiestrogens (AEs) and aromatase inhibitors (AIs). This intratumoral aromatase xenograft model has proved accurate in predicting the outcome of several clinical trials. In this current study we compared the effect of an AE toremifene and steroidal AI atamestane, alone or in combination, on growth of hormone dependent human breast cancer. We have also compared toremifene plus atamestane combination with tamoxifen in this study. The growth of Ac-1 cells was inhibited by tamoxifen, toremifene and atamestane in vitro with IC50 values of 1.8±1.3μM, 1±0.3μM and 60.4±17.2μM, respectively. The combination of toremifene plus atamestane was found to be better than toremifene or atamestane alone in vitro. The effect of this combination was then studied in vivo using Ac-1 xenografts grown in ovariectomized female SCID mice. The mice were injected with toremifene (1000μg/day), atamestane (1000μg/day), tamoxifen (100μg/day), or the combination of toremifene plus atamestane. In this study, our results indicate that the combination of toremifene plus atamestane was as effective as toremifene or tamoxifen alone but may not provide any additional benefit over toremifene alone or tamoxifen alone. PMID:17942301

  6. The purification and properties of placental histaminase

    PubMed Central

    Smith, J. K.

    1967-01-01

    1. Histaminase was extracted from desanguinated human placentae and purified by salt fractionation, ion-exchange chromatography and gel filtration. The purest preparation was still contaminated with haptoglobin–methaemoglobin. 2. Histaminase activity was measured by the o-aminobenzaldehyde method of Holmstedt & Tham (1959), Kapeller-Adler's (1951) test and a modified spectrophotometric indigodisulphonate test of greater sensitivity. 3. Unless contaminant metal ions were removed, enzymic activity on cadaverine, but not on histamine, fell during purification. When EDTA was added to the working buffers, a constant ratio between activities towards cadaverine and histamine was maintained throughout the later stages of purification, and activities towards the two substrates could not be separated by any of the highly resolving chromatographic analyses employed. 4. The purest preparation oxidized histamine, agmatine and benzylamine more slowly than the C4–C6 aliphatic diamines, but mixed-substrate experiments suggested that all these amines were substrates of histaminase. 5. The substrate and inhibitor specificities of placental histaminase were compared with those of related enzymes from other sources. PMID:4962162

  7. Prevention of spontaneous tumours in female rats by fadrozole hydrochloride, an aromatase inhibitor.

    PubMed Central

    Gunson, D. E.; Steele, R. E.; Chau, R. Y.

    1995-01-01

    Mammary tumours are oestrogen dependent in female Sprague-Dawley rats and in a significant proportion of women, so pharmacological treatment to inhibit oestrogen production is a valuable therapeutic measure to prevent or slow the progression of disease. Here we show that a non-steroidal aromatase inhibitor, which competitively inhibits the conversion of androstenedione to oestrone, prevents the development of both benign and malignant spontaneous mammary neoplasms in female Sprague-Dawley ats. It also slows the spontaneous development of pituitary pars distalis adenomas in female rats, and reduces the incidence of spontaneous hepatocellular tumours in male and female rats. PMID:7639848

  8. Synthesis of Casimiroin and Optimization of Its Quinone Reductase 2 and Aromatase Inhibitory Activities

    SciTech Connect

    Maiti, Arup; Reddy, P.V. Narasimha; Sturdy, Megan; Marler, Laura; Pegan, Scott D.; Mesecar, Andrew D.; Pezzuto, John M.; Cushman, Mark

    2009-08-07

    An efficient method has been developed to synthesize casimiroin (1), a component of the edible fruit of Casimiroa edulis, on a multigram scale in good overall yield. The route was versatile enough to provide an array of compound 1 analogues that were evaluated as QR2 and aromatase inhibitors. In addition, X-ray crystallography studies of QR2 in complex with compound 1 and one of its more potent analogues has provided insight into the mechanism of action of this new series of QR2 inhibitors. The initial biological investigations suggest that compound 1 and its analogues merit further investigation as potential chemopreventive or chemotherapeutic agents.

  9. Placental Cadmium Levels Are Associated with Increased Preeclampsia Risk

    PubMed Central

    Laine, Jessica E.; Ray, Paul; Bodnar, Wanda; Cable, Peter H.; Boggess, Kim; Offenbacher, Steven; Fry, Rebecca C.

    2015-01-01

    Environmental exposure to heavy metals is a potentially modifiable risk factor for preeclampsia (PE). Toxicologically, there are known interactions between the toxic metal cadmium (Cd) and essential metals such as selenium (Se) and zinc (Zn), as these metals can protect against the toxicity of Cd. As they relate to preeclampsia, the interaction between Cd and these essential metals is unknown. The aims of the present study were to measure placental levels of Cd, Se, and Zn in a cohort of 172 pregnant women from across the southeast US and to examine associations of metals levels with the odds of PE in a nested case-control design. Logistic regressions were performed to assess odds ratios (OR) for PE with exposure to Cd controlling for confounders, as well as interactive models with Se or Zn. The mean placental Cd level was 3.6 ng/g, ranging from 0.52 to 14.5 ng/g. There was an increased odds ratio for PE in relationship to placental levels of Cd (OR = 1.5; 95% CI: 1.1–2.2). The Cd-associated OR for PE increased when analyzed in relationship to lower placental Se levels (OR = 2.0; 95% CI: 1.1–3.5) and decreased with higher placental Se levels (OR = 0.98; 95% CI: 0.5–1.9). Similarly, under conditions of lower placental Zn, the Cd-associated OR for PE was elevated (OR = 1.8; 95% CI: 0.8–3.9), whereas with higher placental Zn it was reduced (OR = 1.3; 95% CI: 0.8–2.0). Data from this pilot study suggest that essential metals may play an important role in reducing the odds of Cd-associated preeclampsia and that replication in a larger cohort is warranted. PMID:26422011

  10. Labor Inhibits Placental Mechanistic Target of Rapamycin Complex 1 Signaling

    PubMed Central

    LAGER, Susanne; AYE, Irving L.M.H.; GACCIOLI, Francesca; RAMIREZ, Vanessa I.; JANSSON, Thomas; POWELL, Theresa L.

    2014-01-01

    Introduction Labor induces a myriad of changes in placental gene expression. These changes may represent a physiological adaptation inhibiting placental cellular processes associated with a high demand for oxygen and energy (e.g., protein synthesis and active transport) thereby promoting oxygen and glucose transfer to the fetus. We hypothesized that mechanistic target of rapamycin complex 1 (mTORC1) signaling, a positive regulator of trophoblast protein synthesis and amino acid transport, is inhibited by labor. Methods Placental tissue was collected from healthy, term pregnancies (n=15 no-labor; n=12 labor). Activation of Caspase-1, IRS1/Akt, STAT, mTOR, and inflammatory signaling pathways was determined by Western blot. NFκB p65 and PPARγ DNA binding activity was measured in isolated nuclei. Results Labor increased Caspase-1 activation and mTOR complex 2 signaling, as measured by phosphorylation of Akt (S473). However, mTORC1 signaling was inhibited in response to labor as evidenced by decreased phosphorylation of mTOR (S2448) and 4EBP1 (T37/46 and T70). Labor also decreased NFκB and PPARγ DNA binding activity, while having no effect on IRS1 or STAT signaling pathway. Discussion and conclusion Several placental signaling pathways are affected by labor, which has implications for experimental design in studies of placental signaling. Inhibition of placental mTORC1 signaling in response to labor may serve to down-regulate protein synthesis and amino acid transport, processes that account for a large share of placental oxygen and glucose consumption. We speculate that this response preserves glucose and oxygen for transfer to the fetus during the stressful events of labor. PMID:25454472

  11. Canine cytochrome P-450 pharmacogenetics.

    PubMed

    Court, Michael H

    2013-09-01

    The cytochrome P-450 (CYP) drug metabolizing enzymes are essential for the efficient elimination of many clinically used drugs. These enzymes typically display high interindividual variability in expression and function resulting from enzyme induction, inhibition, and genetic polymorphism thereby predisposing patients to adverse drug reactions or therapeutic failure. There are also substantial species differences in CYP substrate specificity and expression that complicate direct extrapolation of information from humans to veterinary species. This article reviews the available published data regarding the presence and impact of genetic polymorphisms on CYP-dependent drug metabolism in dogs in the context of known human-dog CYP differences.

  12. The roles of c-type cytochromes in algal photosynthesis. Extraction from algae of a cytochrome similar to higher plant cytochrome f.

    PubMed

    Wood, P M

    1977-02-01

    A membrane-bound cytochrome resembling higher plant cytochrome f in many respects has been extracted from the algae Chlamydomonas. Euglena and Anacystis, and partially purified. The spectra of the cytochromes from Chlamydomonas and Euglena are virtually identical to that of parsley cytochrome f, with alpha-band maxima near 554 nm, very asymmetrical beta-bands, and gamma-band maxima at 421 nm. The cytochrome from Anacystis had alpha and gamma-bands both shifted to slightly longer wavelengths. The redox potential of the cytochrome from Chlamydomonas was determined as +350 mV, and its minimum molecular weight in sodium dodecyl sulphate as 31 000. The cytochrome from Euglena showed a rate of reaction with higher plant plastocyanin at least 100 times that of the soluble Euglena cytochrome c-552, and was unaffected by Euglena cytochrome c-552 antiserum. A very fast rate of electron transfer occurred between this cytochrome purified from Euglena and cytochrome c-552. The roles of the membrane-bound and soluble c-type cytochromes in algal photosynthesis are discussed, and it is recommended that the name cytochrome f should be reserved for the membrane-bound cytochrome (to emphasize its affinity with higher plant cytochrome f), while the soluble one should be named by its alpha-band (c-552, c-553, etc.) to make clear its distinctness from higher plant cytochrome f and homology with mitochondrial cytochrome c.

  13. Seasonal Expression of Androgen Receptor, Aromatase, and Estrogen Receptor Alpha and Beta in the Testis of the Wild Ground Squirrel (Citellus Dauricus Brandt)

    PubMed Central

    Li, Q.; Zhang, F.; Zhang, S.; Sheng, X.; Han, Y.; Yuan, Z.; Weng, Q.

    2015-01-01

    The aim of this study was to investigate the seasonal expression of androgen receptor (AR), estrogen receptors α and β (ERα and ERβ) and aromatase cytochrome P450 (P450arom) mRNA and protein by real-time PCR and immunohistochemistry in the wild ground squirrel (WGS) testes. Histologically, all types of spermatogenic cells including mature spermatozoa were identified in the breeding season (April), while spermatogonia and primary spermatocytes were observed in the nonbreeding season (June), and spermatogonia, primary spermatocytes and secondary spermatocytes were found in pre-hibernation (September). AR was present in Leydig cells, peritubular myoid cells and Sertoli cells in the breeding season and pre-hibernation with more intense staining in the breeding season, whereas AR was only found in Leydig cells in the nonbreeding season; P450arom was expressed in Leydig cells, Sertoli cells and germ cells during the breeding season, whereas P450arom was found in Leydig cells and Sertoli cells during pre-hibernation, but P450arom was not present in the nonbreeding season; Stronger immunohistochemical signal for ERα was present in Sertoli cells and Leydig cells during the breeding season; ERβ was only expressed in Leydig cells of the breeding season. Consistent with the immunohistochemical results, the mean mRNA level of AR, P450arom, ERα and ERβ were higher in the testes of the breeding season when compared to pre-hibernation and the nonbreeding season. These results suggested that the seasonal changes in spermatogenesis and testicular recrudescence and regression process in WGSs might be correlated with expression levels of AR, P450arom and ERs, and that estrogen and androgen may play an important autocrine/paracrine role to regulate seasonal testicular function. PMID:25820559

  14. Between-female variation in house sparrow yolk testosterone concentration is negatively associated with CYP19A1 (aromatase) mRNA expression in ovarian follicles.

    PubMed

    Egbert, Jeremy R; Jackson, Melissa F; Rodgers, Buel D; Schwabl, Hubert

    2013-03-01

    Maternally-derived yolk androgens influence the development and long-term phenotype of offspring in oviparous species. Between-female variation in the amounts of these yolk androgens has been associated with a number of social and environmental factors, suggesting that the variation is adaptive, but the mechanisms behind it are unknown. Using two different approaches, we tested the hypothesis that variation in yolk androgen levels across individuals is associated with variation in their capacity to synthesize androgens. First, we injected female house sparrows with exogenous gonadotropin-releasing hormone (GnRH) to maximally stimulate ovarian steroidogenesis. Second, we collected pre-ovulatory follicle tissue and quantified the mRNA expression of four key enzymes of the steroid synthesis pathway: steroidogenic acute regulatory protein (StAR), cytochrome P450-side chain cleavage enzyme (CYP11A1), 17β-hydroxysteroid dehydrogenase (HSD17B1), and aromatase (CYP19A1). Thirty minutes after GnRH injection, androgen concentrations in both the plasma and in the yolks of pre-ovulatory follicles were significantly elevated compared to controls. However, this measure of steroidogenic capacity did not explain variation in yolk testosterone levels, although physiological differences between house sparrows and more widely studied poultry models were revealed by this approach. Steroidogenic enzyme mRNA levels were detectable in all samples and were significantly lower in the most mature pre-ovulatory follicles. Of the four measured genes, CYP19A1 expression exhibited a significant negative relationship with yolk testosterone concentrations in laid eggs, revealing a key mechanism for between-female variation in yolk testosterone. Furthermore, this suggests that any factors which alter the expression of CYP19A1 within an individual female could have dramatic effects on offspring phenotype. PMID:23247271

  15. Enzymatic and Inhibition Mechanism of Human Aromatase (CYP19A1) Enzyme. A Computational Perspective from QM/MM and Classical Molecular Dynamics Simulations.

    PubMed

    Sgrignani, Jacopo; Cavalli, Andrea; Colombo, Giorgio; Magistrato, Alessandra

    2016-01-01

    The enzyme human aromatase (HA), a member of the cytochrome P450 family, catalyses in a highly specific and peculiar manner the conversion of estrogens to androgens. Thus, this enzyme is a relevant target for inhibitor design for the treatment of breast cancer and currently there are several HA inhibitors employed in clinical practice. The HA crystal structure was solved only in 2009 and, since then, several studies have been done to characterize a variety of its structural, dynamical and mechanistic properties. In the last decade, the predictive power and the accuracy of computer simulations techniques, either relying on force field or on "ab initio" description of the system, has enormously increased. This was mainly due to the development of more accurate algorithms, which allow accelerating the time-scale accessible by simulations techniques, and to the increase of computer power. Hence, computer simulations can now accurately paint an atomistic picture to the molecular mechanism of biomolecules providing also an estimate of the kinetic and thermodynamic properties of the enzyme at increasingly quantitative level. In this review, on the basis of selected examples taken from our work, we summarize current active research topics concerning HA enzyme, with a focus on computational studies. In particular, we will illustrate current results and novel hypothesis concerning the final (rate-determining) aromatization step promoted by this enzyme, on how the structural/dynamics/functional properties of HA are modulated in a membrane lipophilic environment, and finally on novel possible (allosteric) inhibition mechanisms which may modulate estrogen production in HA. PMID:27337972

  16. Seasonal expression of androgen receptor, aromatase, and estrogen receptor alpha and beta in the testis of the wild ground squirrel (Citellus dauricus Brandt).

    PubMed

    Li, Q; Zhang, F; Zhang, S; Sheng, X; Han, X; Weng, Q; Yuan, Z

    2015-02-17

    The aim of this study was to investigate the seasonal expression of androgen receptor (AR), estrogen receptors α and β (ERα and ERβ) and aromatase cytochrome P450 (P450arom) mRNA and protein by real-time PCR and immunohistochemistry in the wild ground squirrel (WGS) testes. Histologically, all types of spermatogenic cells including mature spermatozoa were identified in the breeding season (April), while spermatogonia and primary spermatocytes were observed in the nonbreeding season (June), and spermatogonia, primary spermatocytes and secondary spermatocytes were found in pre-hibernation (September). AR was present in Leydig cells, peritubular myoid cells and Sertoli cells in the breeding season and pre-hibernation with more intense staining in the breeding season, whereas AR was only found in Leydig cells in the nonbreeding season; P450arom was expressed in Leydig cells, Sertoli cells and germ cells during the breeding season, whereas P450arom was found in Leydig cells and Sertoli cells during pre-hibernation, but P450arom was not present in the nonbreeding season; stronger immunohistochemical signal for ERα was present in Sertoli cells and Leydig cells during the breeding season; ERβ was only expressed in Leydig cells of the breeding season. Consistent with the immunohistochemical results, the mean mRNA level of AR, P450arom, ERα and ERβ were higher in the testes of the breeding season when compared to pre-hibernation and the nonbreeding season. These results suggested that the seasonal changes in spermatogenesis and testicular recrudescence and regression process in WGSs might be correlated with expression levels of AR, P450arom and ERs, and that estrogen and androgen may play an important autocrine/paracrine role to regulate seasonal testicular function.

  17. The significance of placental ratios in pregnancies complicated by small for gestational age, preeclampsia, and gestational diabetes mellitus

    PubMed Central

    Kim, Hee Sun; Cho, Soo Hyun; Kwon, Han Sung; Sohn, In Sook

    2014-01-01

    Objective This study aimed to evaluate the placental weight, volume, and density, and investigate the significance of placental ratios in pregnancies complicated by small for gestational age (SGA), preeclampsia (PE), and gestational diabetes mellitus (GDM). Methods Two hundred and fifty-four pregnant women were enrolled from August 2005 through July 2013. Participants were divided into four groups: control (n=82), SGA (n=37), PE (n=102), and GDM (n=33). The PE group was classified as PE without intrauterine growth restriction (n=65) and PE with intrauterine growth restriction (n=37). Birth weight, placental weight, placental volume, placental density, and placental ratios including birth weight/placental weight ratio (BPW) and birth weight/placental volume ratio (BPV) were compared between groups. Results Birth weight, placental weight, and placental volume were lower in the SGA group than in the control group. However, the BPW and BPV did not differ between the two groups. Birth weight, placental weight, placental volume, BPW, and BPV were all significantly lower in the PE group than in the control group. Compared with the control group, birth weight, BPW, and BPV were higher in the GDM group, whereas placental weight and volume did not differ in the two groups. Placental density was not significantly different among the four groups. Conclusion Placental ratios based on placental weight, placental volume, placental density, and birth weight are helpful in understanding the pathophysiology of complicated pregnancies. Moreover, they can be used as predictors of pregnancy complications. PMID:25264525

  18. Bidirectional Transfer Study of Polystyrene Nanoparticles across the Placental Barrier in an ex Vivo Human Placental Perfusion Model

    PubMed Central

    Grafmueller, Stefanie; Manser, Pius; Diener, Liliane; Diener, Pierre-André; Maeder-Althaus, Xenia; Maurizi, Lionel; Jochum, Wolfram; Krug, Harald F.; Buerki-Thurnherr, Tina; von Mandach, Ursula

    2015-01-01

    Background Nanoparticle exposure in utero might not be a major concern yet, but it could become more important with the increasing application of nanomaterials in consumer and medical products. Several epidemiologic and in vitro studies have shown that nanoparticles can have potential toxic effects. However, nanoparticles also offer the opportunity to develop new therapeutic strategies to treat specifically either the pregnant mother or the fetus. Previous studies mainly addressed whether nanoparticles are able to cross the placental barrier. However, the transport mechanisms underlying nanoparticle translocation across the placenta are still unknown. Objectives In this study we examined which transport mechanisms underlie the placental transfer of nanoparticles. Methods We used the ex vivo human placental perfusion model to analyze the bidirectional transfer of plain and carboxylate modified polystyrene particles in a size range between 50 and 300 nm. Results We observed that the transport of polystyrene particles in the fetal to maternal direction was significantly higher than for the maternal to fetal direction. Regardless of their ability to cross the placental barrier and the direction of perfusion, all polystyrene particles accumulated in the syncytiotrophoblast of the placental tissue. Conclusions Our results indicate that the syncytiotrophoblast is the key player in regulating nanoparticle transport across the human placenta. The main mechanism underlying this translocation is not based on passive diffusion, but is likely to involve an active, energy-dependent transport pathway. These findings will be important for reproductive toxicology as well as for pharmaceutical engineering of new drug carriers. Citation Grafmueller S, Manser P, Diener L, Diener PA, Maeder-Althaus X, Maurizi L, Jochum W, Krug HF, Buerki-Thurnherr T, von Mandach U, Wick P. 2015. Bidirectional transfer study of polystyrene nanoparticles across the placental barrier in an ex vivo human

  19. Heterogeneous models place the root of the placental mammal phylogeny.

    PubMed

    Morgan, Claire C; Foster, Peter G; Webb, Andrew E; Pisani, Davide; McInerney, James O; O'Connell, Mary J

    2013-09-01

    Heterogeneity among life traits in mammals has resulted in considerable phylogenetic conflict, particularly concerning the position of the placental root. Layered upon this are gene- and lineage-specific variation in amino acid substitution rates and compositional biases. Life trait variations that may impact upon mutational rates are longevity, metabolic rate, body size, and germ line generation time. Over the past 12 years, three main conflicting hypotheses have emerged for the placement of the placental root. These hypotheses place the Atlantogenata (common ancestor of Xenarthra plus Afrotheria), the Afrotheria, or the Xenarthra as the sister group to all other placental mammals. Model adequacy is critical for accurate tree reconstruction and by failing to account for these compositional and character exchange heterogeneities across the tree and data set, previous studies have not provided a strongly supported hypothesis for the placental root. For the first time, models that accommodate both tree and data set heterogeneity have been applied to mammal data. Here, we show the impact of accurate model assignment and the importance of data sets in accommodating model parameters while maintaining the power to reject competing hypotheses. Through these sophisticated methods, we demonstrate the importance of model adequacy, data set power and provide strong support for the Atlantogenata over other competing hypotheses for the position of the placental root.

  20. Important aspects of placental-specific gene transfer.

    PubMed

    Kaufman, Melissa R; Albers, Renee E; Keoni, Chanel; Kulkarni-Datar, Kashmira; Natale, David R; Brown, Thomas L

    2014-10-15

    The placenta is a unique and highly complex organ that develops only during pregnancy and is essential for growth and survival of the developing fetus. The placenta provides the vital exchange of gases and wastes, the necessary nutrients for fetal development, acts as immune barrier that protects against maternal rejection, and produces numerous hormones and growth factors that promote fetal maturity to regulate pregnancy until parturition. Abnormal placental development is a major underlying cause of pregnancy-associated disorders that often result in preterm birth. Defects in placental stem cell propagation, growth, and differentiation are the major factors that affect embryonic and fetal well-being and dramatically increase the risk of pregnancy complications. Understanding the processes that regulate placentation is important in determining the underlying factors behind abnormal placental development. The ability to manipulate genes in a placenta-specific manner provides a unique tool to analyze development and eliminates potentially confounding results that can occur with traditional gene knockouts. Trophoblast stem cells and mouse embryos are not overly amenable to traditional gene transfer techniques. Most viral vectors, however, have a low infection rate and often lead to mosaic transgenesis. Although the traditional method of embryo transfer is intrauterine surgical implantation, the methodology reported here, combining lentiviral blastocyst infection and nonsurgical embryo transfer, leads to highly efficient and placental-specific gene transfer. Numerous advantages of our optimized procedures include increased investigator safety, a reduction in animal stress, rapid and noninvasive embryo transfer, and higher a rate of pregnancy and live birth.

  1. Regional changes of placental vascularization in preeclampsia: a review.

    PubMed

    Sahay, Akriti S; Sundrani, Deepali P; Joshi, Sadhana R

    2015-08-01

    Preeclampsia is characterized by vascular dysfunction and results in maternal and fetal morbidity and mortality. The placenta plays a critical role in the growth and development of the fetus, and recent studies indicate that placental architecture, oxygen availability, and oxidative stress indices vary across different regions of the placenta. Our earlier studies have reported altered maternal angiogenesis and differential placental gene expression and methylation patterns of angiogenic factors in women with preeclampsia when compared with normotensive women. We have also demonstrated lower maternal and placental neurotrophin (NT) levels in women with preeclampsia. Studies suggest that oxidative stress is associated with proteases like matrix metalloproteinases (MMPs) and growth factors like NTs and angiogenic factors known to be involved in the process of angiogenesis. Recently, we have reported regionwise differential oxidative stress, antioxidant enzyme activity, and NT levels in placenta from normotensive control women and women with preeclampsia. The current review describes the regional changes in the placenta and highlights the role of placental oxidative stress in influencing regional differences in the expression of angiogenic factors, MMPs, and NTs. This review discusses the need for further research on various growth factors and proteins involved in the process of placental development across different regions of the placenta. This would help to understand whether regional differences in these factors affect the growth and development of the fetus. PMID:26269153

  2. MicroRNAs in Human Placental Development and Pregnancy Complications

    PubMed Central

    Fu, Guodong; Brkić, Jelena; Hayder, Heyam; Peng, Chun

    2013-01-01

    MicroRNAs (miRNAs) are small non-coding RNAs, which function as critical posttranscriptional regulators of gene expression by promoting mRNA degradation and translational inhibition. Placenta expresses many ubiquitous as well as specific miRNAs. These miRNAs regulate trophoblast cell differentiation, proliferation, apoptosis, invasion/migration, and angiogenesis, suggesting that miRNAs play important roles during placental development. Aberrant miRNAs expression has been linked to pregnancy complications, such as preeclampsia. Recent research of placental miRNAs focuses on identifying placental miRNA species, examining differential expression of miRNAs between placentas from normal and compromised pregnancies, and uncovering the function of miRNAs in the placenta. More studies are required to further understand the functional significance of miRNAs in placental development and to explore the possibility of using miRNAs as biomarkers and therapeutic targets for pregnancy-related disorders. In this paper, we reviewed the current knowledge about the expression and function of miRNAs in placental development, and propose future directions for miRNA studies. PMID:23528856

  3. Maternal protein restriction regulates IGF2 system in placental labyrinth.

    PubMed

    Gao, Haijun; Sathishkumar, Kunju Reddiar; Yallampalli, Uma; Balakrishnan, Meena; Li, Xilong; Wu, Guoyao; Yallampalli, Chandra

    2012-01-01

    This study was to test the hypothesis that altered IGF2 system in the placental labyrinth zone (LZ) impairs feto-placental growth in response to maternal protein restriction. Rats were fed a 20% protein diet and an isocaloric 6 % protein diet (LP) from day 1 to days 14, 18, or 21 of pregnancy. The effects of diet, gender of placenta and fetus, and day of pregnancy on placental weight, fetal weight, and expression of the IGF2 axis in the placental LZ and amino acids in maternal plasma were analyzed. Growth restriction occurred in both female and male fetuses by LP, coincident with impaired LZ growth and efficiency. The expression of Igf2, Igf2P0, Igf1r, Igf2r, Insr, Igfbp1, and Igfbp2 in placental LZ were affected by diet, gender and/or day of pregnancy. Concentrations of total essential amino acids and total nonessential amino acids were reduced and increased, respectively, in maternal plasma of LP-fed rats. These results indicate that adaptation of the IGF2 system in rat LZ occurs in a sex- and time-dependent manner in response to maternal protein restriction; however, these adaptations cannot prevent the growth restriction of both male and female fetuses during late pregnancy.

  4. Heterogeneous Models Place the Root of the Placental Mammal Phylogeny

    PubMed Central

    Morgan, Claire C.; Foster, Peter G.; Webb, Andrew E.; Pisani, Davide; McInerney, James O.; O’Connell, Mary J.

    2013-01-01

    Heterogeneity among life traits in mammals has resulted in considerable phylogenetic conflict, particularly concerning the position of the placental root. Layered upon this are gene- and lineage-specific variation in amino acid substitution rates and compositional biases. Life trait variations that may impact upon mutational rates are longevity, metabolic rate, body size, and germ line generation time. Over the past 12 years, three main conflicting hypotheses have emerged for the placement of the placental root. These hypotheses place the Atlantogenata (common ancestor of Xenarthra plus Afrotheria), the Afrotheria, or the Xenarthra as the sister group to all other placental mammals. Model adequacy is critical for accurate tree reconstruction and by failing to account for these compositional and character exchange heterogeneities across the tree and data set, previous studies have not provided a strongly supported hypothesis for the placental root. For the first time, models that accommodate both tree and data set heterogeneity have been applied to mammal data. Here, we show the impact of accurate model assignment and the importance of data sets in accommodating model parameters while maintaining the power to reject competing hypotheses. Through these sophisticated methods, we demonstrate the importance of model adequacy, data set power and provide strong support for the Atlantogenata over other competing hypotheses for the position of the placental root. PMID:23813979

  5. Assisted reproductive technique increases the risk of placental polyp.

    PubMed

    Baba, Tsuyoshi; Endo, Toshiaki; Ikeda, Keiko; Shimizu, Ayumi; Morishita, Miyuki; Kuno, Yoshika; Honnma, Hiroyuki; Kiya, Tamotsu; Ishioka, Shin-ichi; Saito, Tsuyoshi

    2013-06-01

    The purpose of this study was to clarify the risk factors and outcomes of placental polyp. This retrospective study was conducted on 1645 patients delivered or aborted in Sapporo Medical University from 2007 through 2011. Transvaginal color Doppler ultrasonography, hysteroscopy, contrast-enhanced MRI or 3D-CT angiography were performed. There were 1532 deliveries and 113 abortions. Seventy-one (4.3%) were ART-conceived and the remaining 1574 (95.7%) were non-ART pregnancies. Fifteen (0.91%) cases were confirmed as having placental polyp. Nine cases of placental polyp were identified among the 1574 (0.57%) as non-ART-related pregnancies, and 6 were identified among the 71 (8.5%) as ART-related pregnancies. Thus, pregnancies achieved through ART showed 20x greater incidence of complicating placental polyp than pregnancies achieved through without ART (p = 9.02 × 10(-6); odds ratio, 19.59; 95% confidence interval, 5.27-72.84, logistic regression analysis). Evaluation of blood flow within the polyp showed that in five of seven patients with low blood flow, the polyps spontaneously dropped off 79-115 days postpartum. Thus, ART-related pregnancies may be a risk factor of placental polyp, and spontaneous drop-off of the polyp is often observed in cases with low blood flow within the mass.

  6. Crystallization of Mitochondrial Cytochrome Oxidase

    NASA Astrophysics Data System (ADS)

    Ozawa, Takayuki; Tanaka, Masashi; Wakabayashi, Takashi

    1982-12-01

    Cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase, EC 1.9.3.1) was purified from beef heart mitochondria. By washing the oxidase with detergent on a hydrophobic interaction column, phospholipids were depleted to the level of 1 mol of cardiolipin per mol of heme a. Hydrophobic impurities and partially denatured oxidase were separated from the intact oxidase on an affinity column with cytochrome c as the specific ligand. The final preparation of the oxidase contained seven distinct polypeptides. The molecular weight of the oxidase was estimated to be 130,000 from its specific heme a and copper content and from the subunit composition. Crystals of the oxidase were obtained by slow removal of the detergent from the buffer in which the oxidase was dissolved. The needle-shaped crystals were 100 μ m in average length and 5 μ m in width, and they strongly polarized visible light. Electron diffraction patterns were obtained with an unstained glutaraldehyde-fixed single crystal by electron microscopy using 1,000-kV electrons. From electron micrographs and the diffraction patterns of the crystal, it was concluded that the crystal is monoclinic in the space group P21, with unit cell dimensions a = 92 angstrom, b = 84 angstrom, and c = 103 angstrom, and α =β 90 degrees, γ = 126 degrees.

  7. Mitochondrial Cytochrome c Oxidase Deficiency

    PubMed Central

    Rak, Malgorzata; Bénit, Paule; Chrétien, Dominique; Bouchereau, Juliette; Schiff, Manuel; El-Khoury, Riyad; Tzagoloff, Alexander; Rustin, Pierre

    2016-01-01

    As with other mitochondrial respiratory chain components, marked clinical and genetic heterogeneity is observed in patients with a cytochrome c oxidase deficiency. This constitutes a considerable diagnostic challenge and raises a number of puzzling questions. So far, pathological mutations have been reported in more than 30 genes, in both mitochondrial and nuclear DNA, affecting either structural subunits of the enzyme or proteins involved in its biogenesis. In this review, we discuss the possible causes of the discrepancy between the spectacular advances made in the identification of the molecular bases of cytochrome oxidase deficiency and the lack of any efficient treatment in diseases resulting from such deficiencies. This brings back many unsolved questions related to the frequent delay of clinical manifestation, variable course and severity, and tissue-involvement often associated with these diseases. In this context, we stress the importance to study different models of these diseases, but also discuss the limitations encountered in most available disease models. In the future, with the possible exception of replacement therapy using genes, cells or organs, a better understanding of underlying mechanism(s) of these mitochondrial diseases is presumably required to develop efficient therapy. PMID:26846578

  8. Oxidative titrations of reduced cytochrome aa3: influence of cytochrome c and carbon monoxide on the midpoint potential values.

    PubMed

    Schroedl, N A; Hartzell, C R

    1977-11-15

    Oxidative titrations were performed on the electrostatic complex formed between cytochrome c and cytochrome aa3 at low ionic strength. Midpoint potentials of the redox centers in the proteins in 1:1 and 2:1 complexes were compared with those in mixtures of the cytochromes at high ionic strength. Computer simulations of all titrations yielded midpoint potentials for the components of cytochrome aa3 which were consistent with literature values for isolated cytochrome aa3 or mixture of cytochromes c and aa3. However, the unequal heme extinction coefficients observed previously (Schroedl, N.A., and Hartzell, C.R. (1977), Biochemistry 16, 1327) during oxidative titrations of cytochrome aa3 became equal in magnitude under these experimental conditions. The binding of cytochrome c to cytochrome aa3 changed the midpoint potentials of cytochrome aa3 by 15-20 mV, while the midpoint potentials for cytochrome c were altered by 50-60 mV. Careful analysis of these titrations including computer simulation revealed that cytochrome c was able to bind to cytochrome aa3 only after cytochrome aL2+ had become oxidized. When bound to cytochrome aa3, the midpoint potential of cytochrome c was 210 7V. Titrations performed under a carbon monoxide atmosphere revealed cytochrome aa3 midpoint potentials unchanged from reported values. Cytochrome c again exhibited a midpoint potential of 210 mV after binding to cytochrome aa3.

  9. Aromatase Deficient Female Mice Demonstrate Altered Expression of Molecules Critical for Renal Calcium Reabsorption

    NASA Astrophysics Data System (ADS)

    Öz, Orhan K.; Hajibeigi, Asghar; Cummins, Carolyn; van Abel, Monique; Bindels, René J.; Kuro-o, Makoto; Pak, Charles Y. C.; Zerwekh, Joseph E.

    2007-04-01

    The incidence of kidney stones increases in women after the menopause, suggesting a role for estrogen deficiency. In order to determine if estrogen may be exerting an effect on renal calcium reabsorption, we measured urinary calcium excretion in the aromatase-deficient female mouse (ArKO) before and following estrogen therapy. ArKO mice had hypercalciuria that corrected during estrogen administration. To evaluate the mechanism by which estrogen deficiency leads to hypercalciuria, we examined the expression of several proteins involved in distal tubule renal calcium reabsorption, both at the message and protein levels. Messenger RNA levels of TRPV5, TRPV6, calbindin-D28K, the Na+/Ca++ exchanger (NCX1), and the plasma membrane calcium ATPase (PMCA1b) were significantly decreased in kidneys of ArKO mice. On the other hand, klotho mRNA levels were elevated in kidneys of ArKO mice. ArKO renal protein extracts had lower levels of calbindin-D28K but higher levels of the klotho protein. Immunochemistry demonstrated increased klotho expression in ArKO kidneys. Estradiol therapy normalized the expression of TRPV5, calbindin-D28K, PMCA1b and klotho. Taken together, these results demonstrate that estrogen deficiency produced by aromatase inactivation is sufficient to produce a renal leak of calcium and consequent hypercalciuria. This may represent one mechanism leading to the increased incidence of kidney stones following the menopause in women.

  10. 3D QSAR Studies, Pharmacophore Modeling and Virtual Screening on a Series of Steroidal Aromatase Inhibitors

    PubMed Central

    Xie, Huiding; Qiu, Kaixiong; Xie, Xiaoguang

    2014-01-01

    Aromatase inhibitors are the most important targets in treatment of estrogen-dependent cancers. In order to search for potent steroidal aromatase inhibitors (SAIs) with lower side effects and overcome cellular resistance, comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were performed on a series of SAIs to build 3D QSAR models. The reliable and predictive CoMFA and CoMSIA models were obtained with statistical results (CoMFA: q2 = 0.636, r2ncv = 0.988, r2pred = 0.658; CoMSIA: q2 = 0.843, r2ncv = 0.989, r2pred = 0.601). This 3D QSAR approach provides significant insights that can be used to develop novel and potent SAIs. In addition, Genetic algorithm with linear assignment of hypermolecular alignment of database (GALAHAD) was used to derive 3D pharmacophore models. The selected pharmacophore model contains two acceptor atoms and four hydrophobic centers, which was used as a 3D query for virtual screening against NCI2000 database. Six hit compounds were obtained and their biological activities were further predicted by the CoMFA and CoMSIA models, which are expected to design potent and novel SAIs. PMID:25405729

  11. Blocking Endogenous Leukemia Inhibitory Factor During Placental Development in Mice Leads to Abnormal Placentation and Pregnancy Loss

    PubMed Central

    Winship, Amy; Correia, Jeanne; Krishnan, Tara; Menkhorst, Ellen; Cuman, Carly; Zhang, Jian-Guo; Nicola, Nicos A.; Dimitriadis, Evdokia

    2015-01-01

    The placenta forms the interface between the maternal and fetal circulation and is critical for the establishment of a healthy pregnancy. Specialized trophoblast cells derived from the embryonic trophectoderm play a pivotal role in the establishment of the placenta. Leukemia inhibitory factor (LIF) is one of the predominant cytokines present in the placenta during early pregnancy. LIF has been shown to regulate trophoblast adhesion and invasion in vitro, however its precise role in vivo is unknown. We hypothesized that LIF would be required for normal placental development in mice. LIF and LIFRα were immunolocalized to placental trophoblasts and fetal vessels in mouse implantation sites during mid-gestation. Temporally blocking LIF action during specific periods of placental development via intraperitoneal administration of our specific LIFRα antagonist, PEGLA, resulted in abnormal placental trophoblast and vascular morphology and reduced activated STAT3 but not ERK. Numerous genes regulating angiogenesis and oxidative stress were altered in the placenta in response to LIF inhibition. Pregnancy viability was also significantly compromised in PEGLA treated mice. Our data suggest that LIF plays an important role in placentation in vivo and the maintenance of healthy pregnancy. PMID:26272398

  12. Human placental coated vesicles contain receptor-bound transferrin.

    PubMed Central

    Booth, A G; Wilson, M J

    1981-01-01

    Human placental coated vesicles have been purified by a method involving sucrose-density-gradient centrifugation and treatment with wheat-germ agglutinin. These preparations were free of contamination by placental microvillus fragments. Crossed immunoelectrophoresis demonstrated that the coated vesicles contained a single serum protein, which was identified as transferrin. This transferrin was only observed after the vesicles were treated with a non-ionic detergent, and its behaviour during crossed hydrophobic-interaction immunoelectrophoresis suggested that a large proportion of it was receptor-bound. No other serum proteins, including immunoglobulin G, could be detected in these preparations. Receptor-bound transferrin was the only antigen common to placental coated vesicles and microvilli, implying that other plasma-membrane proteins are excluded from the region of membrane involved in coated-vesicle formation. Images PLATE 2 PLATE 1 Fig. 1. Fig. 2. Fig. 3. PMID:6272755

  13. Non-placental causes of intrauterine growth restriction.

    PubMed

    Hendrix, Nancy; Berghella, Vincenzo

    2008-06-01

    Placental insufficiency, in some form or fashion, is associated with the majority of cases of intrauterine growth restriction (IUGR). There are numerous causes of IUGR which are not caused primarily by placental insufficiency, but indirectly lead to it. The causes of IUGR can be subdivided into fetal and maternal etiologies. The fetal etiologies consist of genetic diseases, congenital malformations, infections, multiple gestations, and placental/cord abnormalities. The maternal etiologies are categorized as follows: (1) decreased uteroplacental blood flow, (2) reduced blood volume, (3) decreased oxygen carrying capacity, (4) nutrition status, (5) teratogens, and (6) miscellaneous causes such as short interpregnancy intervals, race, maternal age, and low socioeconomic status. Knowledge of the etiologies of fetal growth restriction is essential, so that future care can be targeted at prevention. There are several primary and secondary prevention strategies that can be adopted.

  14. Cytochrome a1 of acetobacter aceti is a cytochrome ba functioning as ubiquinol oxidase.

    PubMed

    Matsushita, K; Shinagawa, E; Adachi, O; Ameyama, M

    1990-12-01

    Cytochrome a1 is a classic cytochrome that in the 1930s had already been detected in Acetobacter strains and in the 1950s was identified as a terminal oxidase. However, recent studies did not substantiate the previous observations. We have detected a cytochrome a1-like chromophore in Acetobacter aceti, which was purified and characterized in this study. The cytochrome was solubilized from membranes of the strain with octyl beta-D-glucopyranoside and was purified by single column chromatography. The purified cytochrome exhibited a broad alpha peak around 600-610 nm, which turned to a sharp peak at 589 nm in the presence of cyanide. Carbon monoxide difference spectra of the cytochrome indicated the presence of an alpha-type cytochrome. The cytochrome contained 1 mol each of hemes b and a and probably one copper ion. These results suggest that the cytochrome purified from A. aceti is the so-called cytochrome a1, and thus the existence of the classic cytochrome has been reconfirmed. The purified enzyme consisted of four polypeptides of 55, 35, 22, and 18 kDa, and it showed a sedimentation coefficient of 6.3 S in the native form. The enzyme had a high ubiquinol oxidase activity (140-160 mumol of ubiquinol-2 oxidized per min per mg of protein). When reconstituted into proteoliposomes, the cytochrome could generate an electrochemical proton gradient during oxidation of ubiquinol. Thus, cytochrome a1 of A. aceti has been shown to be a cytochrome ba terminal oxidase capable of generating an electrochemical proton gradient concomitant with ubiquinol oxidation.

  15. Gonadal expression of Sf1 and aromatase during sex determination in the red-eared slider turtle (Trachemys scripta), a reptile with temperature-dependent sex determination.

    PubMed

    Ramsey, Mary; Shoemaker, Christina; Crews, David

    2007-12-01

    Many egg-laying reptiles have temperature-dependent sex determination (TSD), where the offspring sex is determined by incubation temperature during a temperature-sensitive period (TSP) in the middle third of development. The underlying mechanism transducing a temperature cue into an ovary or testis is unknown, but it is known that steroid hormones play an important role. During the TSP, exogenous application of estrogen can override a temperature cue and produce females, while blocking the activity of aromatase (Cyp19a1), the enzyme that converts testosterone to estradiol, produces males from a female-biased temperature. The production of estrogen is a key step in ovarian differentiation for many vertebrates, including TSD reptiles, and temperature-based differences in aromatase expression during the TSP may be a critical step in ovarian determination. Steroidogenic factor-1 (Sf1) is a key gene in vertebrate sex determination and regulates many steroidogenic enzymes, including aromatase. We find that Sf1 and aromatase are differentially expressed during sex determination in the red-eared slider turtle, Trachemys scripta elegans. Sf1 is expressed at higher levels during testis development while aromatase expression increases during ovary determination. We also assayed Sf1 and aromatase response to sex-reversing treatments via temperature or the modulation of estrogen availability. Sf1 expression was redirected to low-level female-specific patterns with feminizing temperature shift or exogenous estradiol application and redirected to more intense male-specific patterns with male-producing temperature shift or inhibition of aromatase activity. Conversely, aromatase expression was redirected to more intense female-specific patterns with female-producing treatment and redirected toward diffuse low-level male-specific patterns with masculinizing sex reversal. Our data do not lend support to a role for Sf1 in the regulation of aromatase expression during slider turtle sex

  16. Potential effects of environmental contaminants on P450 aromatase activity and DNA damage in swallows from the Rio Grande and Somerville, Texas

    USGS Publications Warehouse

    Sitzlar, M.A.; Mora, M.A.; Fleming, J.G.W.; Bazer, F.W.; Bickham, J.W.; Matson, C.W.

    2009-01-01

    Cliff swallows (Petrochelidon pyrrhonota) and cave swallows (P. fulva) were sampled during the breeding season at several locations in the Rio Grande, Texas, to evaluate the potential effects of environmental contaminants on P450 aromatase activity in brain and gonads and DNA damage in blood cells. The tritiated water-release aromatase assay was used to measure aromatase activity and flow cytometry was used to measure DNA damage in nucleated blood cells. There were no significant differences in brain and gonadal aromatase activities or in estimates of DNA damage (HPCV values) among cave swallow colonies from the Lower Rio Grande Valley (LRGV) and Somerville. However, both brain and gonadal aromatase activities were significantly higher (P < 0.05) in male cliff swallows from Laredo than in those from Somerville. Also, DNA damage estimates were significantly higher (P < 0.05) in cliff swallows (males and females combined) from Laredo than in those from Somerville. Contaminants of current high use in the LRGV, such as atrazine, and some of the highly persistent organochlorines, such as toxaphene and DDE, could be potentially associated with modulation of aromatase activity in avian tissues. Previous studies have indicated possible DNA damage in cliff swallows. We did not observe any differences in aromatase activity or DNA damage in cave swallows that could be associated with contaminant exposure. Also, the differences in aromatase activity and DNA damage between male cliff swallows from Laredo and Somerville could not be explained by contaminants measured at each site in previous studies. Our study provides baseline information on brain and gonadal aromatase activity in swallows that could be useful in future studies. ?? 2008 Springer Science+Business Media, LLC.

  17. Vasoactive intestinal peptide enhanced aromatase activity in the neonatal rat ovary before development of primary follicles or responsiveness to follicle-stimulating hormone

    SciTech Connect

    George, F.W.; Ojeda, S.R.

    1987-08-01

    The authors have investigated the factors that regulate aromatase activity in fetal-neonatal rat ovaries. Ovarian aromatase activity (assessed by measuring the amount of /sup 3/H/sub 2/O formed from (1..beta..-/sup 3/H)testosterone) is low prior to birth and increases to values greater than 30 pmol/hr per mg of protein between days 8 and 12 after birth. The appearance of ovarian aromatase coincides with the development of primordial follicles. Fetal-neonatal ovaries maintained in serum-free organ culture do not develop aromatase activity at the expected time. Ovine follicle-stimulating hormone, ovine luteinizing hormone, or their combination failed to induce the enzyme activity in cultured fetal ovaries, whereas follicle-stimulating hormone is effective in preventing the decline in aromatase activity when postnatal day 8 ovaries are placed in culture. In contrast to follicle-stimulating hormone, dibutyryl-cAMP markedly enhances ovarian aromatase in cultured fetal ovaries. Likewise, enhancement of endogenouse cAMP formation with forskolin or cholera toxin caused an increase in enzyme activity within 24 hr. Vasoactive intestinal peptide, a peptide known to occur in ovarian nerves, caused a dose-dependent increase in aromatase activity in fetal ovaries prior to folliculogenesis. Of related peptides tested, only the peptide having N-terminal histidine and C-terminal isoleucine amide was capable of inducing aromatase activity in fetal ovaries. The fact that VIP can induce aromatase activity in fetal rat ovaries prior to follicle formation and prior to responsiveness to follicle-stimulating hormone suggests that this neuropeptide may play a critical role in ovarian differentiation.

  18. Defining the Biological Domain of Applicability of Adverse Outcome Pathways Across Diverse Species: The Estrogen Receptor/Aromatase Case Study

    EPA Science Inventory

    Aromatase inhibitors (e.g. fadrozole, prochloraz) and estrogen receptor antagonists (e.g. tamoxifen) reduce the circulating concentration of 17β-estradiol, leading to reproductive dysfunction in affected organisms. While these toxic effects are well-characterized in fish and...

  19. Impairments in aromatase expression, reproductive behavior, and sperm quality of male fish exposed to 17β-estradiol.

    PubMed

    Guyón, Noelia F; Roggio, María A; Amé, María V; Hued, Andrea C; Valdés, María E; Giojalas, Laura C; Wunderlin, Daniel A; Bistoni, María A

    2012-05-01

    Growing evidence shows that environmental estrogen can reach levels that are high enough to exert adverse reproductive effects on wild fish populations. The authors report different parameters of male reproductive behavior, brain, and gonadal aromatase expression, as well as sperm quality in an internally fertilizing fish species (Jenynsia multidentata, Jenyns) exposed to environmentally relevant concentrations of 17β-estradiol (E(2) ). Adult males were exposed to 0, 50, 100, and 250 ng/L E(2) over 28 d. The authors' findings demonstrate that E(2) exposure resulted in a very clear increase in brain aromatase transcript abundance at all assayed concentrations compared with control; however, no effects on gonadal aromatase expression were observed. Behavioral measures revealed increased sexual activity at 50 ng/L but not 100 or 250 ng/L E(2) . In contrast to the molecular and behavioral responses, the condition factor, gonadosomatic index, and sperm quality were unaltered by E(2) exposure. The results from the present work suggest that E(2) affects some aspects of the reproductive biology of J. multidentata. These modifications in the reproductive biology caused by exposure to E(2) could potentially lead to long-term effects at population levels that may not always be immediately evident. To the best of the authors' knowledge, this is the first report on the combined effect of E(2) on aromatase expression, sexual behavior, and sperm parameters in fish.

  20. Animal models of human placentation--a review.

    PubMed

    Carter, A M

    2007-04-01

    This review examines the strengths and weaknesses of animal models of human placentation and pays particular attention to the mouse and non-human primates. Analogies can be drawn between mouse and human in placental cell types and genes controlling placental development. There are, however, substantive differences, including a different mode of implantation, a prominent yolk sac placenta, and fewer placental hormones in the mouse. Crucially, trophoblast invasion is very limited in the mouse and transformation of uterine arteries depends on maternal factors. The mouse also has a short gestation and delivers poorly developed young. Guinea pig is a good alternative rodent model and among the few species known to develop pregnancy toxaemia. The sheep is well established as a model in fetal physiology but is of limited value for placental research. The ovine placenta is epitheliochorial, there is no trophoblast invasion of uterine vessels, and the immunology of pregnancy may be quite different. We conclude that continued research on non-human primates is needed to clarify embryonic-endometrial interactions. The interstitial implantation of human is unusual, but the initial interaction between trophoblast and endometrium is similar in macaques and baboons, as is the subsequent lacunar stage. The absence of interstitial trophoblast cells in the monkey is an important difference from human placentation. However, there is a strong resemblance in the way spiral arteries are invaded and transformed in the macaque, baboon and human. Non-human primates are therefore important models for understanding the dysfunction that has been linked to pre-eclampsia and fetal growth restriction. Models that are likely to be established in the wake of comparative genomics include the marmoset, tree shrew, hedgehog tenrec and nine-banded armadillo.

  1. Sex-Specific Placental Responses in Fetal Development

    PubMed Central

    2015-01-01

    The placenta is an ephemeral but critical organ for the survival of all eutherian mammals and marsupials. It is the primary messenger system between the mother and fetus, where communicational signals, nutrients, waste, gases, and extrinsic factors are exchanged. Although the placenta may buffer the fetus from various environmental insults, placental dysfunction might also contribute to detrimental developmental origins of adult health and disease effects. The placenta of one sex over the other might possess greater ability to respond and buffer against environmental insults. Given the potential role of the placenta in effecting the lifetime health of the offspring, it is not surprising that there has been a resurging interest in this organ, including the Human Placental Project launched by the National Institutes of Child Health and Human Development. In this review, we will compare embryological development of the laboratory mouse and human chorioallantoic placentae. Next, evidence that various species, including humans, exhibit normal sex-dependent structural and functional placental differences will be examined followed by how in utero environmental changes (nutritional state, stress, and exposure to environmental chemicals) might interact with fetal sex to affect this organ. Recent data also suggest that paternal state impacts placental function in a sex-dependent manner. The research to date linking placental maladaptive responses and later developmental origins of adult health and disease effects will be explored. Finally, we will focus on how sex chromosomes and epimutations may contribute to sex-dependent differences in placental function, the unanswered questions, and future directions that warrant further consideration. PMID:26241064

  2. Human Placental MicroRNAs and Preeclampsia1

    PubMed Central

    Chen, Dong-bao; Wang, Wen

    2013-01-01

    ABSTRACT MicroRNAs are a class of noncoding small RNAs that regulate the expression of nearly 30% of all the human genes and participate in all fundamental cell processes. Genome-wide analysis has revealed that human placenta expresses more than 600 miRNA species, including placenta-specific ones with high levels of expression. Comparative analysis also has revealed many differentially expressed miRNAs with either high or low levels of expression in human placentas from normal versus preeclamptic pregnancies, indicating an important role of miRNAs in normal and pathological placental physiology. Although limited information is currently available as to how miRNA regulates human placental development and function, there are studies suggesting that preeclampsia-associated differentially expressed miRNAs possess critical roles in regulating placental development and function via targeting specific genes with diverse known functions. Herein we summarize the current findings regarding the expression of placental miRNAs and their function, especially in the trophoblast cells. We have recently found that the angiogenesis-associated miR-17-family miRNAs are upregulated in preeclamptic compared with normotensive placentas and they target the ephrin-B2/Eph receptor B4 (EPHB4) system. Because ephrin-B2 and EPHB4 has been previously shown to play a crucial role in trophoblast invasion into maternal spiral artery and vascular patterning during early human placental development, the miR-17-ephrin-B2/EPHB4 pathway seems to be a novel miRNA pathway for regulating normal and aberrant placental development during preeclampsia. PMID:23575145

  3. Interleukin-11 alters placentation and causes preeclampsia features in mice

    PubMed Central

    Winship, Amy L.; Koga, Kaori; Menkhorst, Ellen; Van Sinderen, Michelle; Rainczuk, Katarzyna; Nagai, Miwako; Cuman, Carly; Yap, Joanne; Zhang, Jian-Guo; Simmons, David; Young, Morag J.; Dimitriadis, Evdokia

    2015-01-01

    Preeclampsia (PE) is a pregnancy-specific disorder characterized by hypertension and proteinuria after 20 wk gestation. Abnormal extravillous trophoblast (EVT) invasion and remodeling of uterine spiral arterioles is thought to contribute to PE development. Interleukin-11 (IL11) impedes human EVT invasion in vitro and is elevated in PE decidua in women. We demonstrate that IL11 administered to mice causes development of PE features. Immunohistochemistry shows IL11 compromises trophoblast invasion, spiral artery remodeling, and placentation, leading to increased systolic blood pressure (SBP), proteinuria, and intrauterine growth restriction, although nonpregnant mice were unaffected. Real-time PCR array analysis identified pregnancy-associated plasma protein A2 (PAPPA2), associated with PE in women, as an IL11 regulated target. IL11 increased PAPPA2 serum and placental tissue levels in mice. In vitro, IL11 compromised primary human EVT invasion, whereas siRNA knockdown of PAPPA2 alleviated the effect. Genes regulating uterine natural killer (uNK) recruitment and differentiation were down-regulated and uNK cells were reduced after IL11 treatment in mice. IL11 withdrawal in mice at onset of PE features reduced SBP and proteinuria to control levels and alleviated placental labyrinth defects. In women, placental IL11 immunostaining levels increased in PE pregnancies and in serum collected from women before development of early-onset PE, shown by ELISA. These results indicate that elevated IL11 levels result in physiological changes at the maternal–fetal interface, contribute to abnormal placentation, and lead to the development of PE. Targeting placental IL11 may provide a new treatment option for PE. PMID:26655736

  4. Interleukin-11 alters placentation and causes preeclampsia features in mice.

    PubMed

    Winship, Amy L; Koga, Kaori; Menkhorst, Ellen; Van Sinderen, Michelle; Rainczuk, Katarzyna; Nagai, Miwako; Cuman, Carly; Yap, Joanne; Zhang, Jian-Guo; Simmons, David; Young, Morag J; Dimitriadis, Evdokia

    2015-12-29

    Preeclampsia (PE) is a pregnancy-specific disorder characterized by hypertension and proteinuria after 20 wk gestation. Abnormal extravillous trophoblast (EVT) invasion and remodeling of uterine spiral arterioles is thought to contribute to PE development. Interleukin-11 (IL11) impedes human EVT invasion in vitro and is elevated in PE decidua in women. We demonstrate that IL11 administered to mice causes development of PE features. Immunohistochemistry shows IL11 compromises trophoblast invasion, spiral artery remodeling, and placentation, leading to increased systolic blood pressure (SBP), proteinuria, and intrauterine growth restriction, although nonpregnant mice were unaffected. Real-time PCR array analysis identified pregnancy-associated plasma protein A2 (PAPPA2), associated with PE in women, as an IL11 regulated target. IL11 increased PAPPA2 serum and placental tissue levels in mice. In vitro, IL11 compromised primary human EVT invasion, whereas siRNA knockdown of PAPPA2 alleviated the effect. Genes regulating uterine natural killer (uNK) recruitment and differentiation were down-regulated and uNK cells were reduced after IL11 treatment in mice. IL11 withdrawal in mice at onset of PE features reduced SBP and proteinuria to control levels and alleviated placental labyrinth defects. In women, placental IL11 immunostaining levels increased in PE pregnancies and in serum collected from women before development of early-onset PE, shown by ELISA. These results indicate that elevated IL11 levels result in physiological changes at the maternal-fetal interface, contribute to abnormal placentation, and lead to the development of PE. Targeting placental IL11 may provide a new treatment option for PE. PMID:26655736

  5. Dietary protein during gestation affects placental development in heifers.

    PubMed

    Sullivan, T M; Micke, G C; Magalhaes, R S; Phillips, N J; Perry, V E A

    2009-09-01

    The influence of nutritional protein during the first and second trimesters of pregnancy on placental measures at term and caruncle numbers in the uteri of adult offspring was determined in composite beef heifers. At artificial insemination (AI), heifers were divided by weight and composite genotype into four dietary treatment groups, identified by the level of protein components fed during the first and second trimesters: high/high (HH), high/low (HL), low/high (LH), low/low (LL). Expelled placentas were collected and weighed, and cotyledons were dissected, counted, weighed, and measured. Uteri from mature female offspring were dissected at slaughter and caruncles counted. The number of cotyledons in the expelled placenta was increased by high dietary protein in the second trimester (P=0.02) and varied with genotype (P=0.03). Placental weight was influenced by maternal undernutrition during early gestation dependent on dam genotype (P=0.001). Placental efficiency, as determined by calf weight:placental weight, increased with dam age (P=0.03). Calf birth weight was closely associated with placental weight (P=0.002) and cotyledonary weight (P=0.001) and surface area (P=0.04), but not with the number of cotyledons. Leptin concentrations during early (R=-0.29) and late gestation (R=-0.25) correlated with placental weight, and Insulin-like growth factor binding proteins throughout gestation correlated with the number of cotyledons (R=-0.28 to-0.33). The number of uterine caruncles in the nonpregnant adult offspring did not correlate with the dam's genotype, nutrition treatment, or cotyledon number in the expelled placenta.

  6. Infant sex-specific placental cadmium and DNA methylation associations

    SciTech Connect

    Mohanty, April F.; Farin, Fred M.; Bammler, Theo K.; MacDonald, James W.; Afsharinejad, Zahra; Burbacher, Thomas M.; Siscovick, David S.; and others

    2015-04-15

    Background: Recent evidence suggests that maternal cadmium (Cd) burden and fetal growth associations may vary by fetal sex. However, mechanisms contributing to these differences are unknown. Objectives: Among 24 maternal-infant pairs, we investigated infant sex-specific associations between placental Cd and placental genome-wide DNA methylation. Methods: We used ANOVA models to examine sex-stratified associations of placental Cd (dichotomized into high/low Cd using sex-specific Cd median cutoffs) with DNA methylation at each cytosine-phosphate-guanine site or region. Statistical significance was defined using a false discovery rate cutoff (<0.10). Results: Medians of placental Cd among females and males were 5 and 2 ng/g, respectively. Among females, three sites (near ADP-ribosylation factor-like 9 (ARL9), siah E3 ubiquitin protein ligase family member 3 (SIAH3), and heparin sulfate (glucosamine) 3-O-sulfotransferase 4 (HS3ST4) and one region on chromosome 7 (including carnitine O-octanoyltransferase (CROT) and TP5S target 1 (TP53TG1)) were hypomethylated in high Cd placentas. Among males, high placental Cd was associated with methylation of three sites, two (hypomethylated) near MDS1 and EVI1 complex locus (MECOM) and one (hypermethylated) near spalt-like transcription factor 1 (SALL1), and two regions (both hypomethylated, one on chromosome 3 including MECOM and another on chromosome 8 including rho guanine nucleotide exchange factor (GEF) 10 (ARHGEF10). Differentially methylated sites were at or close to transcription start sites of genes involved in cell damage response (SIAH3, HS3ST4, TP53TG1) in females and cell differentiation, angiogenesis and organ development (MECOM, SALL1) in males. Conclusions: Our preliminary study supports infant sex-specific placental Cd-DNA methylation associations, possibly accounting for previously reported differences in Cd-fetal growth associations across fetal sex. Larger studies are needed to replicate and extend these

  7. Sources for Comparative Studies of Placentation. II. Genomic Resources

    PubMed Central

    Wildman, Derek E.

    2008-01-01

    The genomes of dozens of placental mammal species are now publicly available. These genome sequences have the potential to provide insight into the development and evolution of the placenta. In particular, the variable anatomy of the placenta has likely been affected by natural selection on the genomes of living and extinct mammals. In this note the current availability of mammal genome sequences is reviewed, and strengths and limitations of these data are discussed. Additionally, museums, zoos, and commercial entities are available to provide genomic resources to the placental research community. Recommendations for tissue storage conditions of placentas in genomic research are given. PMID:18155141

  8. Concurrent conjunctivitis and placentitis in aborted bovine fetuses.

    PubMed

    Murray, R D

    1991-11-01

    Consistent histopathological lesions were found in 10 out of 136 aborted fetuses examined during a three year period, using a multi-disciplinary diagnostic investigation technique. Fetuses exhibited a generalized mononuclear inflammatory cell infiltration, accompanied by distinctive lesions of conjunctival hyperplasia and goblet cell formation, alveolitis, and necrotic placentitis. In two cases where amnion was also examined, a chronic amnionitis was present. No consistent laboratory findings could be related to these cases. The fetal and placental lesions described were similar to those associated with experimental inoculation of Ureaplasma diversum in pregnant cows, and with field isolations of the same organism in aborting cattle.

  9. An aromatase-associated cytoplasmic inclusion, the "stigmoid body," in the rat brain: II. Ultrastructure (with a review of its history and nomenclature).

    PubMed

    Shinoda, K; Nagano, M; Osawa, Y

    1993-03-01

    The ultrastructure of aromatase-associated "stigmoid (dot-like) structures," which were detected in a previous study using light-microscopic immunohistochemistry (Shinoda et al.: J. Comp. Neurol. 322:360-376, '92), were examined in the rat medial preoptic region, bed nucleus of the stria terminalis, medial amygdaloid nucleus, and arcuate nucleus by pre- and post-embedding marking with a polyclonal antibody against human placental antigen X-P2 (hPAX-P2) for immuno-electron microscopic analysis. The immunoreactive stigmoid structure was identified as a distinct, non-membrane-bounded cytoplasmic inclusion (approximately 1-3 microns in diameter), which has a granulo-fuzzy texture with moderate-to-low electron density in non-immunostained preparations. It consists of at least four distinct granular and three distinct fibrillo-tubular elements forming a granulo-fibrillar conglomerate. This type of inclusions was formally termed the "stigmoid body" under the electron microscope. The stigmoid body is composed of the outer granulo-fibrillar and inner hyaloplasmic compartments. The immunoreactivity for hPAX-P2 is mainly localized to the former, especially to the low density granulo-fuzzy materials associated with the fibrillo-tubular elements. Identification of the ultrastructure of stigmoid body clarified their prevalence not only in the limbic and hypothalamic regions, but also in sex-steroid-sensitive peripheral tissues (e.g., peripheral sensory ganglia, ovary, testis) by consulting earlier electron-microscopic studies. Reviewing the history and nomenclature of this inclusion body, we reorganized the terminology of related neuronal cytoplasmic inclusions, the terms of which have often been confused, and discussed its functional significance on the basis of the present and previously accumulated data. In conclusion, we emphasized the importance of the stigmoid bodies in the sex-steroid-sensitive neural system because of their large size, high frequency, specific

  10. Comparative study of hop-containing products on human cytochrome p450-mediated metabolism.

    PubMed

    Foster, Brian C; Kearns, Nikia; Arnason, John T; Saleem, Ammar; Ogrodowczyk, Carolina; Desjardins, Suzanne

    2009-06-10

    Thirty-five national and international brands of beer were examined for their potential to affect human cytochrome P450 (CYP)-mediated metabolism. They represented the two main categories of beer, ales and lagers, and included a number of specialty products including bitter (porter, stout), coffee, ice, wheat, Pilsner, and hemp seed. Aliquots were examined for nonvolatile soluble solids, effect on CYP metabolism and P-glycoprotein (Pgp) transport, and major alpha- and beta-hop acids. Wide variance was detected in contents of alcohol, nonvolatile suspended solids, and hop acids and in the potential to affect CYP-mediated metabolism and Pgp-mediated efflux transport. Many of the products affected CYP2C9-mediated metabolism, and only two (NRP 306 and 307) markedly affected CYP3A4; hence, some products have the capacity to affect drug safety. CYP3A4, CYP3A5, CYP3A7, and CYP19 (aromatase) inhibition to the log concentration of beta-acid content was significant with r(2) > 0.37, suggesting that these components can account for some of the variation in inhibition of CYP metabolism.

  11. Currently used pesticides and their mixtures affect the function of sex hormone receptors and aromatase enzyme activity.

    PubMed

    Kjeldsen, Lisbeth Stigaard; Ghisari, Mandana; Bonefeld-Jørgensen, Eva Cecilie

    2013-10-15

    The endocrine-disrupting potential of pesticides is of health concern, since they are found ubiquitously in the environment and in food items. We investigated in vitro effects on estrogen receptor (ER) and androgen receptor (AR) transactivity, and aromatase enzyme activity, of the following pesticides: 2-methyl-4-chlorophenoxyacetic acid (MCPA), terbuthylazine, iodosulfuron-methyl-sodium, mesosulfuron-methyl, metsulfuron-methyl, chlormequat chloride, bitertanol, propiconazole, prothioconazole, mancozeb, cypermethrin, tau fluvalinate, malathion and the metabolite ethylene thiourea (ETU). The pesticides were analyzed alone and in selected mixtures. Effects of the pesticides on ER and AR function were assessed in human breast carcinoma MVLN cells and hamster ovary CHO-K1 cells, respectively, using luciferase reporter gene assays. Effects on aromatase enzyme activity were analyzed in human choriocarcinoma JEG-3 cells, employing the classical [(3)H](2)O method. Five pesticides (terbuthylazine, propiconazole, prothioconazole, cypermethrin and malathion) weakly induced the ER transactivity, and three pesticides (bitertanol, propiconazole and mancozeb) antagonized the AR activity in a concentration-dependent manner. Three pesticides (terbuthylazine, propiconazole and prothioconazole) weakly induced the aromatase activity. In addition, two mixtures, consisting of three pesticides (bitertanol, propiconazole, cypermethrin) and five pesticides (terbuthylazine, bitertanol, propiconazole, cypermethrin, malathion), respectively, induced the ER transactivity and aromatase activity, and additively antagonized the AR transactivity. In conclusion, our data suggest that currently used pesticides possess endocrine-disrupting potential in vitro which can be mediated via ER, AR and aromatase activities. The observed mixture effects emphasize the importance of considering the combined action of pesticides in order to assure proper estimations of related health effect risks. PMID:23871939

  12. Plasma sex steroid concentrations and gonadal aromatase activities in African clawed frogs (Xenopus laevis) from South Africa.

    PubMed

    Hecker, Markus; Giesy, John P; Jones, Paul D; Jooste, Alarik M; Carr, James A; Solomon, Keith R; Smith, Ernest E; Van der Kraak, Glen; Kendall, Ronald J; Du Preez, Louis

    2004-08-01

    Adult African clawed frogs (Xenopus laevis) were collected from a corn-growing region (CGR) and a non-corn-growing region (NCGR) with different exposure profiles for atrazine and related triazines. Physical, chemical, and biological parameters from the catchment areas were also measured. Frogs were surveyed for possible effects of exposure to triazine herbicides on plasma testosterone (T) and estradiol (E2) titers, gonadal aromatase activity, and gonad growth (GSI). Concentrations of both T and E2 varied among locations and were correlated to some accessory factors, such as pH, several ions, and metals. Greatest median plasma T concentrations (males: 19 ng/ml; females: 16 ng/ml) occurred in frogs inhabiting NCGR as compared to those from the CGR (males: 4 ng/ml; females: 1 ng/ml). Median E2 concentrations were also greater in frogs collected from the NCGR (males: 3 ng/ml; females: 28 ng/ml) than those in frogs from the CGR (males: 2 ng/ml; females: 5 ng/ml). Because some exposure to agricultural chemicals at both regions occurred, as did simultaneous exposures to multiple chemicals, a regression analysis was employed. Negative correlations were observed between plasma T concentrations and concentrations of atrazine, deisopropylatrazine, deethylatrazine, and tertbuthylazine in females and between T and diaminochlorotriazine in males. Estradiol in females exhibited a significant negative correlation with atrazine and deethylatrazine. No correlations were observed between gonadal aromatase activity or GSI and any of the agricultural chemicals measured. Median aromatase activities in ovaries varied among sampling sites ranging from 7 to >3000 times greater than those in males when measurable. Testicular aromatase activity was below the detection limit of the assay in male frogs at most of the sites. Although exposure to agricultural inputs did not affect aromatase activities, effects of atrazine or coapplied pesticides on sex steroid homeostasis cannot be excluded at

  13. CREB-regulated transcription co-activator family stimulates promoter II-driven aromatase expression in preadipocytes.

    PubMed

    Samarajeewa, Nirukshi U; Docanto, Maria M; Simpson, Evan R; Brown, Kristy A

    2013-08-01

    The dramatically increased prevalence of breast cancer after menopause is of great concern and is correlated with elevated local levels of estrogens. This is mainly due to an increase in aromatase expression driven by its proximal promoter II (PII). We have previously demonstrated that the CREB co-activator CRTC2 binds directly to PII and stimulates its activity via mechanisms involving LKB1-AMPK in response to prostaglandin E(2) (PGE(2)). There are three members of the CRTC family (CRTC1-3) and this study aimed to characterize the role of other CRTCs in the activation of aromatase PII. The expression and subcellular localization of CRTCs were examined in preadipocytes using qPCR and immunofluorescence. Under basal conditions, CRTC1 expression was the lowest, whereas CRTC3 transcripts were present at higher levels. Basally, CRTC2 and CRTC3 were mainly cytoplasmic and PGE(2) caused their nuclear translocation. Reporter assays and chromatin immunoprecipitation (ChIP) were performed to assess the effect of CRTCs on PII activity and binding. Basal PII activity was significantly increased with all CRTCs. Forskolin (FSK)/phorbol 12-myristate 13-acetate (PMA), to mimic PGE(2), resulted in a further significant increase in PII activity with all CRTCs, with CRTC2 and CRTC3 having greater effects. This was consistent with ChIP data showing an increased binding of CRTCs to PII with FSK/PMA. Moreover, gene silencing of CRTC2 and CRTC3 significantly reduced the FSK/PMA-mediated stimulation of aromatase activity. Interestingly, CRTCs acted cooperatively with CREB1 to increase PII activity, and both CREs were found to be essential for the maximal induction of PII activity by CRTCs. Phosphorylation of CRTC2 at its AMPK target site, Ser 171, dictated its subcellular localization, and the activation of aromatase PII in preadipocytes. In conclusion, this study demonstrates that aromatase regulation in primary human breast preadipocytes involves more than one CRTC.

  14. Currently used pesticides and their mixtures affect the function of sex hormone receptors and aromatase enzyme activity.

    PubMed

    Kjeldsen, Lisbeth Stigaard; Ghisari, Mandana; Bonefeld-Jørgensen, Eva Cecilie

    2013-10-15

    The endocrine-disrupting potential of pesticides is of health concern, since they are found ubiquitously in the environment and in food items. We investigated in vitro effects on estrogen receptor (ER) and androgen receptor (AR) transactivity, and aromatase enzyme activity, of the following pesticides: 2-methyl-4-chlorophenoxyacetic acid (MCPA), terbuthylazine, iodosulfuron-methyl-sodium, mesosulfuron-methyl, metsulfuron-methyl, chlormequat chloride, bitertanol, propiconazole, prothioconazole, mancozeb, cypermethrin, tau fluvalinate, malathion and the metabolite ethylene thiourea (ETU). The pesticides were analyzed alone and in selected mixtures. Effects of the pesticides on ER and AR function were assessed in human breast carcinoma MVLN cells and hamster ovary CHO-K1 cells, respectively, using luciferase reporter gene assays. Effects on aromatase enzyme activity were analyzed in human choriocarcinoma JEG-3 cells, employing the classical [(3)H](2)O method. Five pesticides (terbuthylazine, propiconazole, prothioconazole, cypermethrin and malathion) weakly induced the ER transactivity, and three pesticides (bitertanol, propiconazole and mancozeb) antagonized the AR activity in a concentration-dependent manner. Three pesticides (terbuthylazine, propiconazole and prothioconazole) weakly induced the aromatase activity. In addition, two mixtures, consisting of three pesticides (bitertanol, propiconazole, cypermethrin) and five pesticides (terbuthylazine, bitertanol, propiconazole, cypermethrin, malathion), respectively, induced the ER transactivity and aromatase activity, and additively antagonized the AR transactivity. In conclusion, our data suggest that currently used pesticides possess endocrine-disrupting potential in vitro which can be mediated via ER, AR and aromatase activities. The observed mixture effects emphasize the importance of considering the combined action of pesticides in order to assure proper estimations of related health effect risks.

  15. Management of bone loss in postmenopausal breast cancer patients treated with aromatase inhibitors.

    PubMed

    Cepa, M; Vaz, C

    2015-01-01

    Breast cancer is the most commonly diagnosed cancer among women, but despite survival rates improvement, it is still the second major cause of cancer related death. In postmenopausal women with estrogen receptor (ER) dependent breast cancer, hormone therapy is an option, either by direct inhibition of ER using tamoxifen or by aromatase inhibition, resulting in decreased estrogen production. In this paper these two endocrine therapy approaches are compared in terms of their impact on bone health. Guidance for the prevention of bone loss and occurrence of fractures in postmenopausal women receiving AIs is also proposed. Despite intervention strategies to maintain bone health in AI-treated patients are not well established, recommendations by international societies to identify women with high risk of fracture and advice on the preventive anti-fracture therapy are exposed. Finally, available therapeutic options for management of bone loss in patients receiving AIs are presented. The search strategy for this literature review was conducted by using the key words "aromatase inhibitor*" and "bone loss" OR "aromatase inhibitor*" and "osteoporosis" in the MEDLINE/PubMed database. Nowadays, hormone-responsive breast cancer in postmenopausal women is preferably being treated with AIs instead of tamoxifen, due to clear benefits in disease-free survival and reduced recurrence. AIs have an advantageous side effect profile compared to tamoxifen, however all AIs have detrimental long-term effects on bone, due to nearly complete depletion of estrogens, resulting in increased bone loss and increased risk of fracture. Current recommendations state that all women treated with AIs should be evaluated for their fracture risk prior to initiation of AI-treatment, taking in consideration individual bone mineral density and several risk factors. The thresholds to introduce preventive therapy and drugs proposed differ among the available recommendations. Lifestyle modifications and adequate

  16. Management of sexual dysfunction in postmenopausal breast cancer patients taking adjuvant aromatase inhibitor therapy

    PubMed Central

    Derzko, C.; Elliott, S.; Lam, W.

    2007-01-01

    Treatment with aromatase inhibitors for postmenopausal women with breast cancer has been shown to reduce or obviate invasive procedures such as hysteroscopy or curettage associated with tamoxifen-induced endometrial abnormalities. The side effect of upfront aromatase inhibitors, diminished estrogen synthesis, is similar to that seen with the natural events of aging. The consequences often include vasomotor symptoms (hot flushes) and vaginal dryness and atrophy, which in turn may result in cystitis and vaginitis. Not surprisingly, painful intercourse (dyspareunia) and loss of sexual interest (decreased libido) frequently occur as well. Various interventions, both non-hormonal and hormonal, are currently available to manage these problems. The purpose of the present review is to provide the practitioner with a wide array of management options to assist in treating the sexual consequences of aromatase inhibitors. The suggestions in this review are based on recent literature and on the recommendations set forth both by the North American Menopause Association and in the clinical practice guidelines of the Society of Gynaecologists and Obstetricians of Canada. The complexity of female sexual dysfunction necessitates a biopsychosocial approach to assessment and management alike, with interventions ranging from education and lifestyle changes to sexual counselling, pelvic floor therapies, sexual aids, medications, and dietary supplements—all of which have been reported to have a variable, but often successful, effect on symptom amelioration. Although the use of specific hormone replacement—most commonly local estrogen, and less commonly, systemic estrogen with or without an androgen, progesterone, or the additional of an androgen in an estrogenized woman (or a combination)—may be highly effective, the concern remains that in patients with estrogen-dependent breast cancer, including those receiving anti-estrogenic adjuvant therapies, the use of these hormones may be

  17. A world of cytochrome P450s.

    PubMed

    Nelson, David R

    2013-02-19

    The world we live in is a biosphere influenced by all organisms who inhabit it. It is also an ecology of genes, with some having rather startling effects. The premise put forth in this issue is cytochrome P450 is a significant player in the world around us. Life and the Earth itself would be visibly different and diminished without cytochrome P450s. The contributions to this issue range from evolution on the billion year scale to the colour of roses, from Darwin to Rachel Carson; all as seen through the lens of cytochrome P450.

  18. A world of cytochrome P450s

    PubMed Central

    Nelson, David R.

    2013-01-01

    The world we live in is a biosphere influenced by all organisms who inhabit it. It is also an ecology of genes, with some having rather startling effects. The premise put forth in this issue is cytochrome P450 is a significant player in the world around us. Life and the Earth itself would be visibly different and diminished without cytochrome P450s. The contributions to this issue range from evolution on the billion year scale to the colour of roses, from Darwin to Rachel Carson; all as seen through the lens of cytochrome P450. PMID:23297353

  19. Deletion of P399{sub E}401 in NADPH cytochrome P450 oxidoreductase results in partial mixed oxidase deficiency

    SciTech Connect

    Flueck, Christa E.; Mallet, Delphine; Hofer, Gaby; Samara-Boustani, Dinane; Leger, Juliane; Polak, Michel; Morel, Yves; Pandey, Amit V.

    2011-09-09

    Highlights: {yields} Mutations in human POR cause congenital adrenal hyperplasia. {yields} We are reporting a novel 3 amino acid deletion mutation in POR P399{sub E}401del. {yields} POR mutation P399{sub E}401del decreased P450 activities by 60-85%. {yields} Impairment of steroid metabolism may be caused by multiple hits. {yields} Severity of aromatase inhibition is related to degree of in utero virilization. -- Abstract: P450 oxidoreductase (POR) is the electron donor for all microsomal P450s including steroidogenic enzymes CYP17A1, CYP19A1 and CYP21A2. We found a novel POR mutation P399{sub E}401del in two unrelated Turkish patients with 46,XX disorder of sexual development. Recombinant POR proteins were produced in yeast and tested for their ability to support steroid metabolizing P450 activities. In comparison to wild-type POR, the P399{sub E}401del protein was found to decrease catalytic efficiency of 21-hydroxylation of progesterone by 68%, 17{alpha}-hydroxylation of progesterone by 76%, 17,20-lyase action on 17OH-pregnenolone by 69%, aromatization of androstenedione by 85% and cytochrome c reduction activity by 80%. Protein structure analysis of the three amino acid deletion P399{sub E}401 revealed reduced stability and flexibility of the mutant. In conclusion, P399{sub E}401del is a novel mutation in POR that provides valuable genotype-phenotype and structure-function correlation for mutations in a different region of POR compared to previous studies. Characterization of P399{sub E}401del provides further insight into specificity of different P450s for interaction with POR as well as nature of metabolic disruptions caused by more pronounced effect on specific P450s like CYP17A1 and aromatase.

  20. MicroRNAs in placental health and disease

    PubMed Central

    Mouillet, Jean-Francois; Ouyang, Yingshi; Coyne, Carolyn; Sadovsky, Yoel

    2015-01-01

    MicroRNAs (miRNAs) constitute a large family of small non-coding RNAs encoded by the genomes of most organisms. They regulate gene expression through post-transcriptional mechanisms to attenuate protein output in various genetic networks. The discovery of miRNAs has transformed our understanding of gene regulation and sparked intense efforts intended to harness their potential as diagnostic markers and therapeutic tools. Over the last decade a flurry of studies have shed light on placental miRNAs but have also raised many questions regarding the scope of their biological action. Moreover, the recognition that miRNAs of placental origin are continually released in the maternal circulation throughout pregnancy suggested that circulating miRNAs might serve as biomarkers for placental function during pregnancy. While this generated much enthusiasm, recently recognized challenges have delayed the application of miRNA-based biomarkers and therapeutics in clinical practice. In this review, we summarize key findings in the field and discuss current knowledge related to miRNAs in the context of placental biology. PMID:26428496

  1. Defective implantation and placentation: laying the blueprint for pregnancy complications.

    PubMed

    Norwitz, Errol R

    2006-10-01

    Normal implantation and placentation is critical for pregnancy success. Many pregnancy-related complications that present late in gestation (such as pre-eclampsia and preterm labour) appear to have their origins early in pregnancy with abnormalities in implantation and placental development. Implantation is characterized by invasion of the maternal tissues of the uterus by fetal trophoblast, and the degree to which trophoblast invades these tissues appears to be a major determinant of pregnancy outcome. Excessive invasion can lead to abnormally firm attachment of the placenta to the myometrium (placenta accreta) with increased maternal and perinatal morbidity. Inadequate invasion, specifically restricted endovascular invasion, has been implicated in the pathophysiology of such conditions as pre-eclampsia (gestational proteinuric hypertension), preterm premature rupture of membranes, preterm labour, and intrauterine growth restriction. The molecular and cellular mechanisms responsible for implantation remain enigmatic. This review will include an overview of implantation followed by a discussion of a number of molecular mechanisms implicated in defective implantation and placentation including the role of decidual prostaglandins and haemorrhage in regulating trophoblast invasion. An improved understanding of the molecular mechanisms responsible for abnormal implantation and placentation will likely improve clinicians' abilities to treat disorders that occur along this continuum, including infertility, recurrent pregnancy loss, pre-eclampsia, and preterm birth.

  2. Defective implantation and placentation: laying the blueprint for pregnancy complications.

    PubMed

    Norwitz, Errol R

    2007-01-01

    Normal implantation and placentation is critical for pregnancy success. Many pregnancy-related complications that present late in gestation (such as pre-eclampsia and preterm labour) appear to have their origins early in pregnancy with abnormalities in implantation and placental development. Implantation is characterized by invasion of the maternal tissues of the uterus by fetal trophoblast, and the degree to which trophoblast invades these tissues appears to be a major determinant of pregnancy outcome. Excessive invasion can lead to abnormally firm attachment of the placenta to the myometrium (placenta accreta) with increased maternal and perinatal morbidity. Inadequate invasion, specifically restricted endovascular invasion, has been implicated in the pathophysiology of such conditions as pre-eclampsia (gestational proteinuric hypertension), preterm premature rupture of membranes, preterm labour, and intrauterine growth restriction. The molecular and cellular mechanisms responsible for implantation remain enigmatic. This review will include an overview of implantation followed by a discussion of a number of molecular mechanisms implicated in defective implantation and placentation including the role of decidual prostaglandins and haemorrhage in regulating trophoblast invasion. An improved understanding of the molecular mechanisms responsible for abnormal implantation and placentation will likely improve clinicians' abilities to treat disorders that occur along this continuum, including infertility, recurrent pregnancy loss, pre-eclampsia, and preterm birth.

  3. Placental transfer of the actinides and related heavy elements

    SciTech Connect

    Sikov, M.R.

    1986-11-01

    A selective literature review dealing with prenatal exposure of animals and humans to actinides and related heavy elements, comparative aspects of placental transfer and fetoplacental distribution are considered. General patterns have been derived from typical quantitative values, and used to compare similarities and dissimilarities, and to examine factors responsible for observed differences. 37 refs., 2 tabs.

  4. Placental ischemia induces changes in gene expression in chorionic tissue

    PubMed Central

    Garrett, Michael R.; Granger, Joey P.

    2014-01-01

    Preeclampsia is a serious and common hypertensive complication of pregnancy, affecting ~5 to 8 % of pregnancies. The underlying cause of preeclampsia is believed to be placental ischemia, which causes secretion of pathogenic factors into the maternal circulation. While a number of these factors have been identified, it is likely that others remain to be elucidated. Here, we have utilized a relevant preclinical rodent model of placental ischemia-induced hypertension, the reduced uterine perfusion pressure (RUPP) model, to determine the effect of chronic placental ischemia on the underlying chorionic tissue and placental villi. Tissue from control and RUPP rats were isolated on gestational day 19 and mRNA from these tissues was subjected to microarray analysis to determine differential gene expression. At a statistical cutoff of p <0.05, some 2,557 genes were differentially regulated between the two groups. Interestingly, only a small subset (22) of these genes exhibited changes of greater than 50 % versus control, a large proportion of which were subsequently confirmed using qRT-PCR analysis. Network analysis indicated a strong effect on inflammatory pathways, including those involving NF-κB and inflammatory cytokines. Of the most differentially expressed genes, the predominant gene classes were extracellular remodeling proteins, pro-inflammatory proteins, and a coordinated upregulation of the prolactin genes. The functional implications of these novel factors are discussed. PMID:24668059

  5. Placental Mechanics in the Zika-Microcephaly Relationship.

    PubMed

    Adibi, Jennifer J; Zhao, Yaqi; Cartus, Abigail R; Gupta, Phalguni; Davidson, Lance A

    2016-07-13

    How the Zika virus (ZIKV) accesses the embryo remains unknown. In this issue, Quicke et al. (2016) use an in vitro model of the human placenta to show that placental macrophages are more permissive to ZIKV infection than trophoblasts, which may be refractory to infection (Bayer et al., 2016). PMID:27414496

  6. Placental Mechanics in the Zika-Microcephaly Relationship.

    PubMed

    Adibi, Jennifer J; Zhao, Yaqi; Cartus, Abigail R; Gupta, Phalguni; Davidson, Lance A

    2016-07-13

    How the Zika virus (ZIKV) accesses the embryo remains unknown. In this issue, Quicke et al. (2016) use an in vitro model of the human placenta to show that placental macrophages are more permissive to ZIKV infection than trophoblasts, which may be refractory to infection (Bayer et al., 2016).

  7. Placental diffusing capacities at varied carbon monoxide tensions.

    PubMed Central

    Bissonnette, J M; Wickham, W K; Drummond, W H

    1977-01-01

    To test the hypothesis that carbon monoxide transfer across the placenta is, in part, a facilitated process, we have looked for evidence of saturation kinetics for carbon monoxide. In eight pregnant ewes, fetal to maternal carbon monoxide transfer was examined in a preparation in which the fetal side of the placenta was perfused with blood. The carboxyhemoglobin concentrations on the fetal side of the placenta were varied from 4.8 to 70% in 23 measurements. At increased carbon monoxide tensions, the transfer from fetus to mother always decreased. The slope of log rate of carbon monoxide transfer vs. log partial pressure gradient across the placenta was significantly different from 1. Placental membrane diffusing capacity was calculated separately from total placental diffusing capacity which includes hemoglobin reaction rates and erythrocyte membrane diffusion. Placental membrane diffusing capacity decreased at increased carbon monoxide tensions. Placental permeability for urea did not change with increasing carbon monoxide tensions. These results are consistent with the hypothesis that carbon monoxide diffusion in the placenta is, in part, carrier mediated. PMID:864001

  8. Placental vitamin D receptor (VDR) expression is related to neonatal vitamin D status, placental calcium transfer, and fetal bone length in pregnant adolescents.

    PubMed

    Young, Bridget E; Cooper, Elizabeth M; McIntyre, Allison W; Kent, Tera; Witter, Frank; Harris, Z Leah; O'Brien, Kimberly O

    2014-05-01

    The purpose of the study was to identify determinants of placental vitamin D receptor (VDR) expression and placental calcium (Ca) transfer among pregnant adolescents. Placental tissue was obtained in 94 adolescents (≤18 yr) at term. In 12 of these teens, stable Ca isotopes were given intravenously ((42)Ca) and orally ((44)Ca) early in labor. Placental VDR expression was assessed via Western blot and validated by RT-PCR. Maternal-to-fetal Ca transfer was calculated as the enrichment in cord blood at delivery relative to maternal serum enrichment 2 h postdosing. Isotopic study outcomes were examined in relation to fetal long bone length, placental VDR, serum 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)2D], and parathyroid hormone (PTH) in maternal circulation and cord blood at delivery. Placental VDR expression was inversely associated with neonatal 25(OH)D (P=0.012) and positively with neonatal 1,25(OH)2D (P=0.006). Placental VDR was a positive predictor of fetal femur length Z score (P=0.018; R(2)=0.06) and was positively correlated with maternal-to-fetal transfer of intravenous (42)Ca (P=0.004; R(2)=0.62). The fetus may regulate placental VDR expression given the significant associations with neonatal vitamin D metabolites. The association between placental VDR and fetal long bone length may indicate a role for VDR in fetal bone development, potentially by mediating transplacental Ca transfer.

  9. Placenta with Old, Diffuse Infarction that Was Difficult to Differentiate from a Placental Tumor.

    PubMed

    Miyake, Hidehiko; Miyazaki-Igarashi, Miwa; Suzuki, Shunji

    2015-01-01

    Placental lesions, including placental infarction, are associated with fetal and neonatal mortality and morbidity. We present a case of fetal growth restriction associated with an old, diffuse placental infarction. Because the placenta had only a single viable cotyledon, the others being atrophic, the lesion appeared to be a placental tumor on prenatal ultrasonography. The patient did not have pregnancy-induced hypertension. At 31 weeks of gestation, a cesarean delivery was performed because of fetal growth arrest and breech presentation. A small-for-gestational age infant was delivered with Apgar scores of 8 at both 1 and 5 minutes, and the infant had cleft palate and cleft lips. Pathological examination of the placenta revealed an old, diffuse infarction without neoplastic change. In cases in which a placental tumor causing fetal growth restriction is strongly suspected, diffuse placental infarction should be considered as part of the differential diagnosis, because placental tumors are associated with poor maternal prognosis.

  10. Syncytiotrophoblast Functions and Fetal Growth Restriction during Placental Malaria: Updates and Implication for Future Interventions

    PubMed Central

    Kidima, Winifrida B.

    2015-01-01

    Syncytiotrophoblast lines the intervillous space of the placenta and plays important roles in fetus growth throughout gestation. However, perturbations at the maternal-fetal interface during placental malaria may possibly alter the physiological functions of syncytiotrophoblast and therefore growth and development of the embryo in utero. An understanding of the influence of placental malaria on syncytiotrophoblast function is paramount in developing novel interventions for the control of placental pathology associated with placental malaria. In this review, we discuss how malaria changes syncytiotrophoblast function as evidenced from human, animal, and in vitro studies and, further, how dysregulation of syncytiotrophoblast function may impact fetal growth in utero. We also formulate a hypothesis, stemming from epidemiological observations, that nutrition may override pathogenesis of placental malaria-associated-fetal growth restriction. We therefore recommend studies on nutrition-based-interventional approaches for high placental malaria-risk women in endemic areas. More investigations on the role of nutrition on placental malaria pathogenesis are needed. PMID:26587536

  11. Induction of Female-to-Male Sex Change in Adult Zebrafish by Aromatase Inhibitor Treatment

    NASA Astrophysics Data System (ADS)

    Takatsu, Kanae; Miyaoku, Kaori; Roy, Shimi Rani; Murono, Yuki; Sago, Tomohiro; Itagaki, Hideyuki; Nakamura, Masaru; Tokumoto, Toshinobu

    2013-12-01

    This study investigated whether undifferentiated germ and/or somatic stem cells remain in the differentiated ovary of a species that does not undergo sex changes under natural conditions and retain their sexual plasticity. The effect of aromatase inhibitor (AI)-treatment on sexually mature female zebrafish was examined. A 5-month AI treatment caused retraction of the ovaries after which testes-like organs appeared, and cyst structures filled with spermatozoa-like cells were observed in sections of these tissues. Electron microscopic observations revealed that these cells appeared as large sperm heads without tails. Sperm formation was re-examined after changing the diet to an AI-free food. A large number of normal sperm were obtained after eight weeks, and no formation of ovarian tissue was observed. Artificial fertilization using sperm from the sex-changed females was successful. These results demonstrated that sex plasticity remains in the mature ovaries of this species.

  12. Induction of Female-to-Male Sex Change in Adult Zebrafish by Aromatase Inhibitor Treatment

    PubMed Central

    Takatsu, Kanae; Miyaoku, Kaori; Roy, Shimi Rani; Murono, Yuki; Sago, Tomohiro; Itagaki, Hideyuki; Nakamura, Masaru; Tokumoto, Toshinobu

    2013-01-01

    This study investigated whether undifferentiated germ and/or somatic stem cells remain in the differentiated ovary of a species that does not undergo sex changes under natural conditions and retain their sexual plasticity. The effect of aromatase inhibitor (AI)-treatment on sexually mature female zebrafish was examined. A 5-month AI treatment caused retraction of the ovaries after which testes-like organs appeared, and cyst structures filled with spermatozoa-like cells were observed in sections of these tissues. Electron microscopic observations revealed that these cells appeared as large sperm heads without tails. Sperm formation was re-examined after changing the diet to an AI-free food. A large number of normal sperm were obtained after eight weeks, and no formation of ovarian tissue was observed. Artificial fertilization using sperm from the sex-changed females was successful. These results demonstrated that sex plasticity remains in the mature ovaries of this species. PMID:24292399

  13. Intracomplex electron transfer between ruthenium-cytochrome c derivatives and cytochrome c oxidase.

    PubMed

    Pan, L P; Hibdon, S; Liu, R Q; Durham, B; Millett, F

    1993-08-24

    The reactions of bovine cytochrome c oxidase with horse cytochrome c derivatives labeled at specific lysine amino groups with (dicarboxybipyridine)bis(bipyridine)ruthenium (II) were studied by laser flash photolysis. All of the derivatives form complexes with cytochrome c oxidase at low ionic strength (5 mM sodium phosphate, pH 7). Excitation of Ru(II) to Ru(II*) with a short laser flash resulted in rapid electron transfer to the ferric heme group of cytochrome c, followed by electron transfer to cytochrome c oxidase. The photoreduced heme Fe(II) in the cytochrome c derivative modified at lysine 25 on the periphery of the heme crevice domain transferred an electron to CuA with a rate constant of 1.1 x 10(4) s-1. CuA then transferred an electron to cytochrome a with a rate constant of 2.3 x 10(4) s-1. The derivatives modified at lysines 7, 39, 55, and 60 remote from the heme crevice domain of cytochrome c have nearly the same kinetics. The rate constant for electron transfer from the cytochrome c heme to CuA is greater than 10(5) s-1, and the rate constant for electron transfer from CuA to cytochrome a is 2 x 10(4) s-1. The cytochrome c derivatives modified at lysines 13 and 27 in the heme crevice domain react much more slowly than the other derivatives, with intracomplex rate constants for oxidation of cytochrome c ranging from 1000 to 6000 s-1. The bulky ruthenium group at the heme crevice domain of these derivatives apparently alters the binding orientation, leading to smaller electron-transfer rates.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Resonance Raman fingerprinting of multiheme cytochromes from the cytochrome c3 family.

    PubMed

    Di Paolo, Roberto E; Pereira, Patrícia M; Gomes, Inês; Valente, Filipa M A; Pereira, Inês A C; Franco, Ricardo

    2006-03-01

    Resonance Raman (RR) spectroscopy was used to investigate conformational characteristics of the hemes of several ferricytochromes of the cytochrome c3 family, electron transfer proteins isolated from the periplasm and membranes of sulfate-reducing bacteria. Our analysis concentrated on the low-frequency region of the RR spectra, a fingerprint region that includes vibrations for heme-protein C-S bonds [nu(C(a)S)]. It has been proposed that these bonds are directly involved in the electron transfer process. The three groups of tetraheme cytochrome c3 analyzed, namely Type I cytochrome c (3) (TpIc (3)s), Type II cytochrome c (3) (TpIIc (3)s) and Desulfomicrobium cytochromes c3, display different frequency separations for the two nu(C(a)S) lines that are similar among members of each group. These spectral differences correlate with differences in protein structure observed among the three groups of cytochromes c3. Two larger cytochromes of the cytochrome c3 family display RR spectral characteristics for the nu(C(a)S) lines that are closer to TpIIc3 than to TpIc3. Two other multiheme cytochromes from Desulfovibrio that do not belong to the cytochrome c3 family display nu(C(a)S) lines with reverse relative areas in comparison with the latter family. This RR study shows that the small differences in protein structure observed among these cytochrome c3 correlate to differences on the heme-protein bonds, which are likely to have an impact upon the protein function, making RR spectroscopy a sensitive and useful tool for characterizing these cytochromes.

  15. Mammalian cytochromes P-450: Volume I and Volume II

    SciTech Connect

    Guengerich, F.P.

    1987-01-01

    This two volume set summarizes the current knowledge of mammalian cytochromes. Ten chapters cover the current understanding of the enzymology of rat, rabbit, and human liver cytochromes P-450, extrahepatic cytochromes P-450, the diversity of substrates for the individual cytochromes P0-450 proteins, the metabolism of pro-toxicants and -carcinogens by cytochrome P-450, the degradation of cytochrome P-450 proteins, and the regulation of cytochrome P-450 activities in vitro and in vivo. The individual chapters outline the historical development of each area, the approaches which are applied, the current state of knowledge, and future directions towards unresolved questions; and index.

  16. CYP11A1 expression in bone is associated with aromatase inhibitor-related bone loss.

    PubMed

    Rodríguez-Sanz, M; García-Giralt, N; Prieto-Alhambra, D; Servitja, S; Balcells, S; Pecorelli, R; Díez-Pérez, A; Grinberg, D; Tusquets, I; Nogués, X

    2015-08-01

    Aromatase inhibitors (AIs) used as adjuvant therapy in postmenopausal women with hormone receptor-positive breast cancer cause diverse musculoskeletal side effects that include bone loss and its associated fracture. About half of the 391 patients treated with AIs in the Barcelona-Aromatase induced bone loss in early breast cancer cohort suffered a significant bone loss at lumbar spine (LS) and/or femoral neck (FN) after 2 years on AI-treatment. In contrast, up to one-third (19.6% LS, 38.6% FN) showed no decline or even increased bone density. The present study aimed to determine the genetic basis for this variability. SNPs in candidate genes involved in vitamin D and estrogen hormone-response pathways (CYP11A1, CYP17A1, HSD3B2, HSD17B3, CYP19A1, CYP2C19, CYP2C9, ESR1, DHCR7, GC, CYP2R1, CYP27B1, VDR and CYP24A1) were genotyped for association analysis with AI-related bone loss (AIBL). After multiple testing correction, 3 tag-SNPs (rs4077581, s11632698 and rs900798) located in the CYP11A1 gene were significantly associated (P<0.005) with FN AIBL at 2 years of treatment. Next, CYP11A1 expression in human fresh bone tissue and primary osteoblasts was demonstrated by RT-PCR. Both common isoforms of human cholesterol side-chain cleavage enzyme (encoded by CYP11A1 gene) were detected in osteoblasts by western blot. In conclusion, the genetic association of CYP11A1 gene with AIBL and its expression in bone tissue reveals a potential local function of this enzyme in bone metabolism regulation, offering a new vision of the steroidogenic ability of this tissue and new understanding of AI-induced bone loss. PMID:26108486

  17. CYP11A1 expression in bone is associated with aromatase inhibitor-related bone loss.

    PubMed

    Rodríguez-Sanz, M; García-Giralt, N; Prieto-Alhambra, D; Servitja, S; Balcells, S; Pecorelli, R; Díez-Pérez, A; Grinberg, D; Tusquets, I; Nogués, X

    2015-08-01

    Aromatase inhibitors (AIs) used as adjuvant therapy in postmenopausal women with hormone receptor-positive breast cancer cause diverse musculoskeletal side effects that include bone loss and its associated fracture. About half of the 391 patients treated with AIs in the Barcelona-Aromatase induced bone loss in early breast cancer cohort suffered a significant bone loss at lumbar spine (LS) and/or femoral neck (FN) after 2 years on AI-treatment. In contrast, up to one-third (19.6% LS, 38.6% FN) showed no decline or even increased bone density. The present study aimed to determine the genetic basis for this variability. SNPs in candidate genes involved in vitamin D and estrogen hormone-response pathways (CYP11A1, CYP17A1, HSD3B2, HSD17B3, CYP19A1, CYP2C19, CYP2C9, ESR1, DHCR7, GC, CYP2R1, CYP27B1, VDR and CYP24A1) were genotyped for association analysis with AI-related bone loss (AIBL). After multiple testing correction, 3 tag-SNPs (rs4077581, s11632698 and rs900798) located in the CYP11A1 gene were significantly associated (P<0.005) with FN AIBL at 2 years of treatment. Next, CYP11A1 expression in human fresh bone tissue and primary osteoblasts was demonstrated by RT-PCR. Both common isoforms of human cholesterol side-chain cleavage enzyme (encoded by CYP11A1 gene) were detected in osteoblasts by western blot. In conclusion, the genetic association of CYP11A1 gene with AIBL and its expression in bone tissue reveals a potential local function of this enzyme in bone metabolism regulation, offering a new vision of the steroidogenic ability of this tissue and new understanding of AI-induced bone loss.

  18. Orexin Decreases Aromatase Gene Expression in The Hypothalamus of Androgenized Female Rats

    PubMed Central

    Salimi, Maliheh; Alishah, Zahra; Khazali, Homayoun; Mahmoudi, Fariba

    2016-01-01

    Background Orexin is a hypothalamic orexigenic neuropeptide, which third cerebral injection of it mainly exerts inhibitory effects on reproductive functions. It increases significantly the Aromatase (Cyp19) gene expression in the hypothalamus of male rats. Aromatase is an enzyme which converts androgens to estradiol in the hypothalamus of rats. Prenatal or neonatal exposure of females to testosterone masculinizes the pattern of Cyp19 mRNA levels in adulthood. In the present study the effects of central injections of orexin-A on hypothalamic Cyp19 gene expression of adult female rats were investigated, while they had been androgenized on third day of postnatal life. Materials and Methods In this experimental study, twenty female Wistar rats received subcutaneous injections of testosterone propionate (50 µg/100 µl) on their third day of postnatal life. Adult androgenized rats weighing 180-220 g, received either 3 µl saline or one of 2, 4 or 8 µg/3 µl concentration of orexin via third cerebral ventricle. Five non-androgenized rats, as control group, received intra cerebral ventricle (ICV) injection of 3 µl saline. The hypothalamuses were dissected out and mean Cyp19 mRNA levels were determined by semi-quantitative real time-polymerase chain reaction (PCR) method. Data were analyzed by unpaired t test and one-way ANOVA using SPSS software, version 16. Results Mean relative Cyp19 mRNA level was significantly increased in the hypothalamus of androgenized compared to non-androgenized female rats. Central injec- tions of 2, 4 or 8 µg/3 µl orexin decreased significantly the hypothalamic Cyp19 mRNA level of androgenized rats compared to androgenized-control groups. Conclusion The results suggested that the orexin may exert inhibitory effects on the gene expression of Cyp19 in the hypothalamus of neonatal androgenized female rats in adulthood. PMID:27441052

  19. Expression of Estrogen-Related Gene Markers in Breast Cancer Tissue Predicts Aromatase Inhibitor Responsiveness

    PubMed Central

    Moy, Irene; Lin, Zhihong; Rademaker, Alfred W.; Reierstad, Scott; Khan, Seema A.; Bulun, Serdar E.

    2013-01-01

    Aromatase inhibitors (AIs) are the most effective class of drugs in the endocrine treatment of breast cancer, with an approximate 50% treatment response rate. Our objective was to determine whether intratumoral expression levels of estrogen-related genes are predictive of AI responsiveness in postmenopausal women with breast cancer. Primary breast carcinomas were obtained from 112 women who received AI therapy after failing adjuvant tamoxifen therapy and developing recurrent breast cancer. Tumor ERα and PR protein expression were analyzed by immunohistochemistry (IHC). Messenger RNA (mRNA) levels of 5 estrogen-related genes–AKR1C3, aromatase, ERα, and 2 estradiol/ERα target genes, BRCA1 and PR–were measured by real-time PCR. Tumor protein and mRNA levels were compared with breast cancer progression rates to determine predictive accuracy. Responsiveness to AI therapy–defined as the combined complete response, partial response, and stable disease rates for at least 6 months–was 51%; rates were 56% in ERα-IHC-positive and 14% in ERα-IHC-negative tumors. Levels of ERα, PR, or BRCA1 mRNA were independently predictive for responsiveness to AI. In cross-validated analyses, a combined measurement of tumor ERα and PR mRNA levels yielded a more superior specificity (36%) and identical sensitivity (96%) to the current clinical practice (ERα/PR-IHC). In patients with ERα/PR-IHC-negative tumors, analysis of mRNA expression revealed either non-significant trends or statistically significant positive predictive values for AI responsiveness. In conclusion, expression levels of estrogen-related mRNAs are predictive for AI responsiveness in postmenopausal women with breast cancer, and mRNA expression analysis may improve patient selection. PMID:24223121

  20. Placental ABC transporters, cellular toxicity and stress in pregnancy.

    PubMed

    Aye, Irving L M H; Keelan, Jeffrey A

    2013-04-25

    The human placenta, in addition to its roles as a nutrient transfer and endocrine organ, functions as a selective barrier to protect the fetus against the harmful effects of exogenous and endogenous toxins. Members of the ATP-binding cassette (ABC) family of transport proteins limit the entry of xenobiotics into the fetal circulation via vectorial efflux from the placenta to the maternal circulation. Several members of the ABC family, including proteins from the ABCA, ABCB, ABCC and ABCG subfamilies, have been shown to be functional in the placenta with clinically significant roles in xenobiotic efflux. However, recent findings suggest that these transporters also protect placental tissue by preventing the cellular accumulation of cytotoxic compounds such as lipids, sterols and their derivatives. Such protective functions are likely to be particularly important in pregnancies complicated by inflammatory or oxidative stress, where the generation of toxic metabolites is enhanced. For example, ABC transporters have been shown to protect against the harmful effects of hypoxia and oxidative stress through increased expression and efflux of oxysterols and glutathione conjugated xenobiotics. However, this protective capacity may be diminished in response to the same stressors. Several studies in primary human trophoblast cells and animal models have demonstrated decreased expression and activity of placental ABC transporters with inflammatory, oxidative or metabolic stress. Several clinical studies in pregnancies complicated by inflammatory conditions such as preeclampsia and gestational diabetes support these findings, although further studies are required to determine the clinical relevance of the relationships between placental ABC transporter expression and activity, and placental function in stressed pregnancies. Such studies are necessary to fully understand the consequences of pregnancy disorders on placental function and viability in order to optimise pregnancy

  1. The impact of ionizing radiation on placental trophoblasts

    PubMed Central

    Kanter, D.J.; O'Brien, M.B.; Shi, X.-H.; Chu, T.; Mishima, T.; Beriwal, S.; Epperly, M.W.; Wipf, P.; Greenberger, J.S.; Sadovsky, Y.

    2014-01-01

    Introduction Exposure to low-dose radiation is widespread and attributable to natural sources. However, occupational, medical, accidental, and terrorist-related exposures remain a significant threat. Information on radiation injury to the feto-placental unit is scant and largely observational. We hypothesized that radiation causes trophoblast injury, and alters the expression of injury-related transcripts in vitro or in vivo, thus affecting fetal growth. Methods Primary human trophoblasts (PHTs), BeWo or NCCIT cells were irradiated in vitro, and cell number and viability were determined. Pregnant C57Bl/6HNsd mice were externally irradiated on E13.5, and placentas examined on E17.5. RNA expression was analyzed using microarrays and RT-qPCR. The experiments were repeated in the presence of the gramicidin S (GS)-derived nitroxide JP4-039, used to mitigate radiation-induced cell injury. Results We found that survival of in vitro–irradiated PHT cell was better than that of irradiated BeWo trophoblast cell line or the radiosensitive NCCIT mixed germ cell tumor line. Radiation altered the expression of several trophoblast genes, with a most dramatic effect on CDKN1A (p21, CIP1). Mice exposed to radiation at E13.5 exhibited a 25% reduction in mean weight by E17.5, and a 9% reduction in placental weight, which was associated with relatively small changes in placental gene expression. JP4-039 had a minimal effect on feto-placental growth or on gene expression in irradiated PHT cells or mouse placenta. Discussion and conclusion While radiation affects placental trophoblasts, the established placenta is fairly resistant to radiation, and changes in this tissue may not fully account for fetal growth restriction induced by ionizing radiation. PMID:24418702

  2. Indomethacin is a Placental Vasodilator in the Dog

    PubMed Central

    Gerber, John G.; Branch, Robert A.; Hubbard, Walter C.; Nies, Alan S.

    1978-01-01

    The effect of 8 mg/kg of indomethacin on uterine blood flow, prostaglandin production, and intraamniotic fluid pressure was examined in late pregnant dogs. Uterine blood flow was measured with 15 μm radiolabeled microspheres. Because we found that a significant percentage of the microspheres shunted through the placental circulation into the lungs, we calculated placental blood flow by adding the shunted microspheres through the placenta to the nonshunted microspheres in the placenta. Total uterine blood flow significantly increased from 271±69 ml/min during control period to 371±72 ml/min (P < 0.01) 30 min after indomethacin. This increase was attributable to the change in blood flow to the placental circulation (222±58 to 325±63 ml/min; P < 0.01). Associated with these hemodynamic changes we found an almost complete suppression of uterine prostaglandin E2 production (1,654±305 to 51±25 pg/ml; P < 0.01) as measured by gas chromatography-mass spectrometry. In addition, we found that indomethacin treatment resulted in uterine relaxation as measured by intraamniotic fluid pressure changes (11.2±1.3 mm Hg to 8.5±1.2 mm Hg; P < 0.001). We conclude that indomethacin causes an increase in placental blood flow without any change in flow to the rest of the uterus, and that this dose of the drug inhibits greater than 95% of uterine prostaglandin production. In addition, indomethacin is responsible for uterine relaxation. The increase in placental blood flow after indomethacin is probably a result of uterine relaxation, which is secondary to prostaglandin synthesis inhibition. PMID:659627

  3. Placental inflammation is not increased in inflammatory bowel disease

    PubMed Central

    Taleban, Sasha; Gundogan, Fusun; Chien, Edward K.; Degli-Esposti, Silvia; Saha, Sumona

    2015-01-01

    Background Women with inflammatory bowel disease (IBD) are at increased risk for adverse birth outcomes such as preterm delivery and small for gestational age (SGA) infants. Most recognized cases of fetal growth restriction in singleton pregnancies have underlying placental causes. However, studies in IBD examining poor birth outcomes have focused on maternal factors. We examined whether women with IBD have a higher rate of placental inflammation than non-IBD controls. Methods Between 2008 and 2011, the placental tissue of 7 ulcerative colitis, 5 Crohn’s disease, and 2 IBD-unclassified subjects enrolled in the Pregnancy in Inflammatory Bowel Disease and Neonatal Outcome (PIANO) registry were evaluated for villitis, deciduitis, and chorioamnionitis with/without a fetal inflammatory response. The history and birth outcomes of all IBD subjects were reviewed and matched to 26 non-IBD controls by gestational age at delivery. Results Of women with IBD, 29% delivered preterm infants and 21% delivered SGA infants. Half of the IBD patients had mild-moderate disease flares during pregnancy. Five (36%) patients required corticosteroids, 2 (14%) were maintained on an immunomodulator, and 3 (21%) others received tumor necrosis factor-alpha inhibitors during their pregnancy. Chorioamnionitis was the only identified placental pathology present in the placentas reviewed, occurring less frequently in cases compared to controls (7% vs. 27%, P=0.32). Conclusions Placental inflammatory activation does not appear to be responsible for the increase in adverse birth outcome in women with IBD. Further studies are necessary to validate these findings in IBD to explain poor birth outcomes. PMID:26423206

  4. The dynamic complex of cytochrome c6 and cytochrome f studied with paramagnetic NMR spectroscopy.

    PubMed

    Díaz-Moreno, Irene; Hulsker, Rinske; Skubak, Pavol; Foerster, Johannes M; Cavazzini, Davide; Finiguerra, Michelina G; Díaz-Quintana, Antonio; Moreno-Beltrán, Blas; Rossi, Gian-Luigi; Ullmann, G Matthias; Pannu, Navraj S; De la Rosa, Miguel A; Ubbink, Marcellus

    2014-08-01

    The rapid transfer of electrons in the photosynthetic redox chain is achieved by the formation of short-lived complexes of cytochrome b6f with the electron transfer proteins plastocyanin and cytochrome c6. A balance must exist between fast intermolecular electron transfer and rapid dissociation, which requires the formation of a complex that has limited specificity. The interaction of the soluble fragment of cytochrome f and cytochrome c6 from the cyanobacterium Nostoc sp. PCC 7119 was studied using NMR spectroscopy and X-ray diffraction. The crystal structures of wild type, M58H and M58C cytochrome c6 were determined. The M58C variant is an excellent low potential mimic of the wild type protein and was used in chemical shift perturbation and paramagnetic relaxation NMR experiments to characterize the complex with cytochrome f. The interaction is highly dynamic and can be described as a pure encounter complex, with no dominant stereospecific complex. Ensemble docking calculations and Monte-Carlo simulations suggest a model in which charge-charge interactions pre-orient cytochrome c6 with its haem edge toward cytochrome f to form an ensemble of orientations with extensive contacts between the hydrophobic patches on both cytochromes, bringing the two haem groups sufficiently close to allow for rapid electron transfer. This model of complex formation allows for a gradual increase and decrease of the hydrophobic interactions during association and dissociation, thus avoiding a high transition state barrier that would slow down the dissociation process.

  5. Cytochromes P460 and c'-beta; a new family of high-spin cytochromes c.

    PubMed

    Elmore, Bradley O; Bergmann, David J; Klotz, Martin G; Hooper, Alan B

    2007-03-01

    Cytochromes-P460 of Nitrosomonas europaea and Methylococcus capsulatus (Bath), and the cytochrome c' of M. capsulatus, believed to be involved in binding or transformation of N-oxides, are shown to represent an evolutionarily related new family of monoheme, approximately 17kDa, cytochromes c found in the genomes of diverse Proteobacteria. All members of this family have a predicted secondary structure predominantly of beta-sheets in contrast to the predominantly alpha-helical cytochromes c' found in photoheterotrophic and denitrifying Proteobacteria.

  6. The dynamic complex of cytochrome c6 and cytochrome f studied with paramagnetic NMR spectroscopy.

    PubMed

    Díaz-Moreno, Irene; Hulsker, Rinske; Skubak, Pavol; Foerster, Johannes M; Cavazzini, Davide; Finiguerra, Michelina G; Díaz-Quintana, Antonio; Moreno-Beltrán, Blas; Rossi, Gian-Luigi; Ullmann, G Matthias; Pannu, Navraj S; De la Rosa, Miguel A; Ubbink, Marcellus

    2014-08-01

    The rapid transfer of electrons in the photosynthetic redox chain is achieved by the formation of short-lived complexes of cytochrome b6f with the electron transfer proteins plastocyanin and cytochrome c6. A balance must exist between fast intermolecular electron transfer and rapid dissociation, which requires the formation of a complex that has limited specificity. The interaction of the soluble fragment of cytochrome f and cytochrome c6 from the cyanobacterium Nostoc sp. PCC 7119 was studied using NMR spectroscopy and X-ray diffraction. The crystal structures of wild type, M58H and M58C cytochrome c6 were determined. The M58C variant is an excellent low potential mimic of the wild type protein and was used in chemical shift perturbation and paramagnetic relaxation NMR experiments to characterize the complex with cytochrome f. The interaction is highly dynamic and can be described as a pure encounter complex, with no dominant stereospecific complex. Ensemble docking calculations and Monte-Carlo simulations suggest a model in which charge-charge interactions pre-orient cytochrome c6 with its haem edge toward cytochrome f to form an ensemble of orientations with extensive contacts between the hydrophobic patches on both cytochromes, bringing the two haem groups sufficiently close to allow for rapid electron transfer. This model of complex formation allows for a gradual increase and decrease of the hydrophobic interactions during association and dissociation, thus avoiding a high transition state barrier that would slow down the dissociation process. PMID:24685428

  7. Blastomere removal from cleavage-stage mouse embryos alters placental function, which is associated with placental oxidative stress and inflammation

    PubMed Central

    Yao, Qi; Chen, Li; Liang, Yuanjiao; Sui, Liucai; Guo, Li; Zhou, Jingwei; Fan, Kai; Jing, Jun; Zhang, Yunhai; Yao, Bing

    2016-01-01

    Blastomere biopsy is an essential technique in preimplantation genetic diagnosis (PGD), a screening test that can detect genetic abnormalities of embryos before their transfer into uterus. Our results showed that the weights of fetuses derived from biopsied embryos were lower than that of non-biopsied counterparts at E12.5, E15.5, and E18.5. The ratio of fetal/placental (F/P) weights in the biopsied group was significantly lower than that in the non-biopsied group at E18.5. At E18.5, the mRNAs for selected glucose transporters, system A amino acid transporters, system L amino acid transporters, and imprinted genes were downregulated in the placentae of biopsied group, and the GLUT1 and CAT3 protein levels were decreased too. More apoptotic cells were detected by TUNEL in the placentae of biopsied group. Placentae from biopsied embryos exhibited lower levels of SOD and GSH. Furthermore, the concentration of MDA increased in the placentae from biopsied group. The levels of IL1B, IL6, and TNFA also significantly increased in the placentae of biopsied group. This study suggested that placental function may be sensitive to blastomere biopsy procedures, and placental oxidative stress and inflammation associated with blastomere biopsy may be critical factors of abnormal placental function and further influence the fetal development. PMID:27109212

  8. Prenatal diagnosis of a placental infarction hematoma associated with fetal growth restriction, preeclampsia and fetal death: clinicopathological correlation.

    PubMed

    Aurioles-Garibay, Alma; Hernandez-Andrade, Edgar; Romero, Roberto; Qureshi, Faisal; Ahn, Hyunyoung; Jacques, Suzanne M; Garcia, Maynor; Yeo, Lami; Hassan, Sonia S

    2014-01-01

    The lesion termed 'placental infarction hematoma' is associated with fetal death and adverse perinatal outcome. Such a lesion has been associated with a high risk of fetal death and abruption placentae. The fetal and placental hemodynamic changes associated with placental infarction hematoma have not been reported. This paper describes a case of early and severe growth restriction with preeclampsia, and progressive deterioration of the fetal and placental Doppler parameters in the presence of a placental infarction hematoma.

  9. Luminogenic cytochrome P450 assays.

    PubMed

    Cali, James J; Ma, Dongping; Sobol, Mary; Simpson, Daniel J; Frackman, Susan; Good, Troy D; Daily, William J; Liu, David

    2006-08-01

    Luminogenic cytochrome P450 (CYP) assays couple CYP enzyme activity to firefly luciferase luminescence in a technology called P450-Glo(TM) (Promega). Luminogenic substrates are used in assays of human CYP1A1, -1A2, -1B1, -2C8, -2C9, -2C19, -2D6, -2J2, -3A4, -3A7, -4A11, -4F3B, -4F12 and -19. The assays detect dose-dependent CYP inhibition by test compounds against recombinant CYP enzymes or liver microsomes. Induction or inhibition of CYP activities in cultured hepatocytes is measured in a nonlytic approach that leaves cells intact for additional analysis. Luminogenic CYP assays offer advantages of speed and safety over HPLC and radiochemical-based methods. Compared with fluorogenic methods the approach offers advantages of improved sensitivity and decreased interference between optical properties of test compound and CYP substrate. These homogenous assays are sensitive and robust tools for high-throughput CYP screening in early drug discovery. PMID:16859410

  10. Islet secretory granules contain cytochrome b561.

    PubMed

    Mackin, R B; Jones, D P; Noe, B D

    1986-08-01

    A cytochrome has been detected in secretory granules prepared from anglerfish islets of Langerhans. The heme moiety was determined to be of the b type, and the dithionite-reduced cytochrome exhibited an alpha-band maximum at 561 nm with an extinction coefficient of 13.8 mM-1 X cm-1. The protein was present at a concentration of 40 +/- 4 pmol/mg of secretory granule protein. The cytochrome was found to be an integral membrane protein and to be reduced by ascorbic acid but not by NADH, NADPH, reduced glutathione (GSH), or succinate. Because of the similarity to previously characterized secretory granule cytochrome b561's from neuroendocrine tissues, this cytochrome is also referred to as cytochrome b561. Although its function has not yet been elucidated, the apparent specificity for ascorbate suggests that it may be a component of the ascorbate-dependent peptidyl-glycine alpha-amidating monooxygenase system that functions in the amidation of islet hormones. PMID:3525285

  11. Cytochrome bd Displays Significant Quinol Peroxidase Activity

    PubMed Central

    Al-Attar, Sinan; Yu, Yuanjie; Pinkse, Martijn; Hoeser, Jo; Friedrich, Thorsten; Bald, Dirk; de Vries, Simon

    2016-01-01

    Cytochrome bd is a prokaryotic terminal oxidase that catalyses the electrogenic reduction of oxygen to water using ubiquinol as electron donor. Cytochrome bd is a tri-haem integral membrane enzyme carrying a low-spin haem b558, and two high-spin haems: b595 and d. Here we show that besides its oxidase activity, cytochrome bd from Escherichia coli is a genuine quinol peroxidase (QPO) that reduces hydrogen peroxide to water. The highly active and pure enzyme preparation used in this study did not display the catalase activity recently reported for E. coli cytochrome bd. To our knowledge, cytochrome bd is the first membrane-bound quinol peroxidase detected in E. coli. The observation that cytochrome bd is a quinol peroxidase, can provide a biochemical basis for its role in detoxification of hydrogen peroxide and may explain the frequent findings reported in the literature that indicate increased sensitivity to hydrogen peroxide and decreased virulence in mutants that lack the enzyme. PMID:27279363

  12. Unique Distribution of Aromatase in the Human Brain: In Vivo Studies With PET and [N-Methyl-11C]Vorozole

    SciTech Connect

    Biegon, A.; Biegon, A.; Kim, S.W.; Alexoff, D.; Millard, J.; Carter, P.; Hubbard, B.; King, P.; Logan, J.; Muench, L.; Pareto, D.; Schlyer, D.; Shea, C.; Telang, F.; Wang, G.-J.; Xu, Y.; Fowler, J.

    2010-10-01

    Aromatase catalyzes the last step in estrogen biosynthesis. Brain aromatase is involved in diverse neurophysiological and behavioral functions including sexual behavior, aggression, cognition, and neuroprotection. Using positron emission tomography (PET) with the radiolabeled aromatase inhibitor [N-methyl-{sup 11}C]vorozole, we characterized the tracer distribution and kinetics in the living human brain. Six young, healthy subjects, three men and three women, were administered the radiotracer alone on two separate occasions. Women were scanned in distinct phases of the menstrual cycle. Specificity was confirmed by pretreatment with a pharmacological (2.5 mg) dose of the aromatase inhibitor letrozole. PET data were acquired over a 90-min period and regions of interest placed over selected brain regions. Brain and plasma time activity curves, corrected for metabolites, were used to derive kinetic parameters. Distribution volume (V{sub T}) values in both men and women followed the following rank order: thalamus > amygdala = preoptic area > medulla (inferior olive) > accumbens, pons, occipital and temporal cortex, putamen, cerebellum, and white matter. Pretreatment with letrozole reduced VT in all regions, though the size of the reduction was region-dependent, ranging from {approx}70% blocking in thalamus andpreoptic area to {approx}10% in cerebellum. The high levels of aromatase in thalamus and medulla (inferior olive) appear to be unique to humans. These studies set the stage for the noninvasive assessment of aromatase involvement in various physiological and pathological processes affecting the human brain.

  13. Unique distribution of aromatase in the human brain: in vivo studies with PET and [N-methyl-11C]vorozole.

    PubMed

    Biegon, Anat; Kim, Sung Won; Alexoff, David L; Jayne, Millard; Carter, Pauline; Hubbard, Barbara; King, Payton; Logan, Jean; Muench, Lisa; Pareto, Deborah; Schlyer, David; Shea, Colleen; Telang, Frank; Wang, Gene-Jack; Xu, Youwen; Fowler, Joanna S

    2010-11-01

    Aromatase catalyzes the last step in estrogen biosynthesis. Brain aromatase is involved in diverse neurophysiological and behavioral functions including sexual behavior, aggression, cognition, and neuroprotection. Using positron emission tomography (PET) with the radiolabeled aromatase inhibitor [N-methyl-(11)C]vorozole, we characterized the tracer distribution and kinetics in the living human brain. Six young, healthy subjects, three men and three women, were administered the radiotracer alone on two separate occasions. Women were scanned in distinct phases of the menstrual cycle. Specificity was confirmed by pretreatment with a pharmacological (2.5 mg) dose of the aromatase inhibitor letrozole. PET data were acquired over a 90-min period and regions of interest placed over selected brain regions. Brain and plasma time activity curves, corrected for metabolites, were used to derive kinetic parameters. Distribution volume (V(T)) values in both men and women followed the following rank order: thalamus > amygdala = preoptic area > medulla (inferior olive) > accumbens, pons, occipital and temporal cortex, putamen, cerebellum, and white matter. Pretreatment with letrozole reduced V(T) in all regions, though the size of the reduction was region-dependent, ranging from ∼70% blocking in thalamus andpreoptic area to ∼10% in cerebellum. The high levels of aromatase in thalamus and medulla (inferior olive) appear to be unique to humans. These studies set the stage for the noninvasive assessment of aromatase involvement in various physiological and pathological processes affecting the human brain.

  14. Unique distribution of aromatase in the human brain: in vivo studies with PET and [N-methyl-11C]vorozole

    PubMed Central

    Biegon, Anat; Kim, Sung Won; Alexoff, David L.; Jayne, Millard; Carter, Pauline; Hubbard, Barbara; King, Payton; Logan, Jean; Muench, Lisa; Pareto, Deborah; Schlyer, David; Shea, Colleen; Telang, Frank; Wang, Gene-Jack; Xu, Youwen; Fowler, Joanna S.

    2010-01-01

    Aromatase catalyzes the last step in estrogen biosynthesis. Brain aromatase is involved in diverse neurophysiological and behavioral functions including sexual behavior, aggression, cognition and neuroprotection. Using positron emission tomography (PET) with the radiolabeled aromatase inhibitor [N-methyl-11C]vorozole, we characterized the tracer distribution and kinetics in the living human brain. Six young, healthy subjects, 3 men and 3 women, were administered the radiotracer alone on two separate occasions. Women were scanned in distinct phases of the menstrual cycle. Specificity was confirmed by pretreatment with a pharmacological (2.5mg) dose of the aromatase inhibitor letrozole. PET data were acquired over a 90 min period and regions of interest placed over selected brain regions. Brain and plasma time activity curves, corrected for metabolites, were used to derive kinetic parameters. Distribution volume (VT) values in both men and women followed the rank order: thalamus>amygdala=preoptic area>medulla(inferior olive) > accumbens, pons, occipital and temporal cortex, putamen, cerebellum and white matter. Pretreatment with letrozole reduced VT in all regions, though the size of the reduction was region dependent; ranging from ~70% blocking in thalamus and preoptic area to ~10% in cerebellum. The high levels of aromatase in thalamus and medulla (inferior olive) appear to be unique to humans. These studies set the stage for the non-invasive assessment of aromatase involvement in various physiological and pathological processes affecting the human brain. PMID:20842717

  15. Simultaneous purification and characterization of cytochrome b5 reductase and cytochrome b5 from sheep liver.

    PubMed

    Arinç, E; Cakir, D

    1999-02-01

    Cytochrome b5 was purified from detergent solubilized sheep liver microsomes by using three successive DEAE-cellulose, and Sephadex G-100 column chromatographies. It was purified 54-fold and the yield was 23.5% with respect to microsomes. The apparent Mr of cytochrome b5 was estimated to be 16,200 +/- 500 by SDS-PAGE. Absolute absorption spectrum of the purified cytochrome b5 showed maximal absorption at 412 nm and dithionite-reduced cytochrome b5 gave peaks at 557, 526.5 and 423 nm. The ability of the purified sheep liver cytochrome b5 to transfer electrons from NADH-cytochrome b5 reductase to cytochrome c was investigated. The K(m) and Vmax values were calculated to be 0.088 microM cytochrome b5 and 315.8 microM cytochrome c reduced/min/mg enzyme, respectively. Also the reduction of cytochrome b5 by reductase was studied and K(m) and Vmax values were determined to be 5 microM cytochrome b5 and 5200 nmol cytochrome b5 reduced/min/mg enzyme, respectively. The K(m) and Vmax values for the cofactor NADH in the presence of saturating concentration of cytochrome b5 were found to be 0.0017 mM NADH and 6944 nmol cytochrome b5 reduced/min/mg enzyme, respectively. NADH-cytochrome b5 reductase was also partially purified from the same source, detergent solubilized sheep liver microsomes, by using two successive DEAE-cellulose, and 5'-ADP-agarose affinity column chromatographies. It was purified 144-fold and the yield was 7% with respect to microsomes. The apparent monomer Mr of reductase was estimated to be 34,000 by SDS-PAGE. When ferricyanide was used as an electron acceptor, reductase showed maximum activity between 6.8 and 7.5. The K(m) and Vmax values of the enzyme for ferricyanide were calculated as 0.024 mM ferricyanide and 673 mumol ferricyanide reduced/min/mg enzyme, respectively. The K(m) and Vmax values for the cofactor NADH in the presence of saturating amounts of ferricyanide were found to be 0.020 mM NADH and 699 mumol ferricyanide reduced/min/mg enzyme

  16. MOLECULAR CLONING AND STAGE-DEPENDENT EXPRESSION OF A CYTOCHROME P450 AROMATASE DURING SPERMATOGENESIS IN SHARK (SQUALUS ACANTHIAS) TESTIS. (R825434)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  17. Influence of Triazine Herbicide Exposure on Guppies (Poecilia sphenops) Aromatase Activities, Altered Sex Steroid Concentration and Vitellogenin Induction.

    PubMed

    Vasanth, S; Arul, G; Karthikeyeni, S; Kumar, T S V; Vignesh, V; Manimegalai, M; Bupesh, G; Thirumurugan, R; Subramanian, P

    2015-01-01

    Atrazine, a herbicide is one the most toxic and sustaining pollutants in aquatic environment. It is detectable in surface water and in underground sources of drinking water. Many studies indicate that atrazine might be a potent endocrine disrupting xenobiotic. There are limited studies have revealed that the effects of atrazine on sex steroids hormones, vitellogenin and induction of aromatase, gonadosomatic index and hepatosomatic index. In this study, juvenile Poecilia sphenops fish was exposed to three different (0.83, 1.25 and 2.5 ppm) concentration of atrazine for 100 d. Changes in plasma and gonadal content and concentrations of sex steroids and vitellogenin protein in poecilia sphenops under laboratory conditions were assessed. The low level of the atrazine show estrogenic effect in males, as determined by a shortage of testosterone induction. Present study suggests that low induction of plasma vitellogenin and aromatase in male fish become suitable biomarkers of exposure to estrogenic chemicals. PMID:26009647

  18. Influence of Triazine Herbicide Exposure on Guppies (Poecilia sphenops) Aromatase Activities, Altered Sex Steroid Concentration and Vitellogenin Induction

    PubMed Central

    Vasanth, S.; Arul, G.; Karthikeyeni, S.; Kumar, T. S. V.; Vignesh, V.; Manimegalai, M.; Bupesh, G.; Thirumurugan, R.; Subramanian, P.

    2015-01-01

    Atrazine, a herbicide is one the most toxic and sustaining pollutants in aquatic environment. It is detectable in surface water and in underground sources of drinking water. Many studies indicate that atrazine might be a potent endocrine disrupting xenobiotic. There are limited studies have revealed that the effects of atrazine on sex steroids hormones, vitellogenin and induction of aromatase, gonadosomatic index and hepatosomatic index. In this study, juvenile Poecilia sphenops fish was exposed to three different (0.83, 1.25 and 2.5 ppm) concentration of atrazine for 100 d. Changes in plasma and gonadal content and concentrations of sex steroids and vitellogenin protein in poecilia sphenops under laboratory conditions were assessed. The low level of the atrazine show estrogenic effect in males, as determined by a shortage of testosterone induction. Present study suggests that low induction of plasma vitellogenin and aromatase in male fish become suitable biomarkers of exposure to estrogenic chemicals. PMID:26009647

  19. Influence of Triazine Herbicide Exposure on Guppies (Poecilia sphenops) Aromatase Activities, Altered Sex Steroid Concentration and Vitellogenin Induction.

    PubMed

    Vasanth, S; Arul, G; Karthikeyeni, S; Kumar, T S V; Vignesh, V; Manimegalai, M; Bupesh, G; Thirumurugan, R; Subramanian, P

    2015-01-01

    Atrazine, a herbicide is one the most toxic and sustaining pollutants in aquatic environment. It is detectable in surface water and in underground sources of drinking water. Many studies indicate that atrazine might be a potent endocrine disrupting xenobiotic. There are limited studies have revealed that the effects of atrazine on sex steroids hormones, vitellogenin and induction of aromatase, gonadosomatic index and hepatosomatic index. In this study, juvenile Poecilia sphenops fish was exposed to three different (0.83, 1.25 and 2.5 ppm) concentration of atrazine for 100 d. Changes in plasma and gonadal content and concentrations of sex steroids and vitellogenin protein in poecilia sphenops under laboratory conditions were assessed. The low level of the atrazine show estrogenic effect in males, as determined by a shortage of testosterone induction. Present study suggests that low induction of plasma vitellogenin and aromatase in male fish become suitable biomarkers of exposure to estrogenic chemicals.

  20. The role of aromatase inhibitors in ameliorating deleterious effects of ovarian stimulation on outcome of infertility treatment

    PubMed Central

    Mitwally, Mohamed FM; Casper, Robert F; Diamond, Michael P

    2005-01-01

    Clinical utilization of ovulation stimulation to facilitate the ability of a couple to conceive has not only provided a valuable therapeutic approach, but has also yielded extensive information on the physiology of ovarian follicular recruitment, endometrial receptivity and early embryo competency. One of the consequences of the use of fertility enhancing agents for ovarian stimulation has been the creation of a hyperestrogenic state, which may influence each of these parameters. Use of aromatase inhibitors reduces hyperestrogenism inevitably attained during ovarian stimulation. In addition, the adjunct use of aromatase inhibitors during ovarian stimulation reduces amount of gonadotropins required for optimum stimulation. The unique approach of reducing hyperestrogenism, as well as lowering amount of gonadotropins without affecting the number of mature ovarian follicles is an exciting strategy that could result in improvement in the treatment outcome by ameliorating the deleterious effects of the ovarian stimulation on follicular development, endometrial receptivity, as well as oocyte and embryo quality. PMID:16202169

  1. IFPA Meeting 2011 workshop report III: Placental immunology; epigenetic and microRNA-dependent gene regulation; comparative placentation; trophoblast differentiation; stem cells☆

    PubMed Central

    Ackerman, W.E.; Bulmer, J.N.; Carter, A.M.; Chaillet, J.R.; Chamley, L.; Chen, C.P.; Chuong, E.B.; Coleman, S.J.; Collet, G.P.; Croy, B.A.; de Mestre, A.M.; Dickinson, H.; Ducray, J.; Enders, A.C.; Fogarty, N.M.E.; Gauster, M.; Golos, T.; Haider, S.; Heazell, A.E.; Holland, O.J.; Huppertz, B.; Husebekk, A.; John, R.M.; Johnsen, G.M.; Jones, C.J.P.; Kalionis, B.; König, J.; Lorenzon, A.R.; Moffett, A.; de Mello, J.C. Moreira; Nuzzo, A.M.; Parham, P.; Parolini, O.; Petroff, M.G.; Pidoux, G.; Ramírez-Pinilla, M.P.; Robinson, W.P.; Rolfo, A.; Sadovsky, Y.; Soma, H.; Southcombe, J.H.; Tilburgs, T.; Lash, G.E.

    2014-01-01

    Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialised topics. At IFPA meeting 2011 there were twelve themed workshops, five of which are summarized in this report. These workshops related to various aspects of placental biology: 1) immunology; 2) epigenetics; 3) comparative placentation; 4) trophoblast differentiation; 5) stem cells. PMID:22154501

  2. Relationship between Plasma D-Dimer Concentration and Three-Dimensional Ultrasound Placental Volume in Women at Risk for Placental Vascular Diseases: A Monocentric Prospective Study

    PubMed Central

    Fanget, Cécile; Chauleur, Céline; Stadler, Amandine; Presles, Emilie; Varlet, Marie-Noëlle; Gris, Jean-Christophe

    2016-01-01

    Introduction The aim of this study was to correlate placental volumes deduced from three-dimensional ultrasound and virtual organ computer-aided analysis (VOCAL) software with systemic concentrations of D-dimer and soluble endothelial protein C receptor (sEPCR). Methods This was a monocentric experimental prospective study conducted from October 2008 to July 2009. Forty consecutive patients at risk of placental vascular pathology (PVP) recurrence or occurrence were included. Placental volumes were systematically measured three times (11–14, 16–18 and 20–22 weeks of gestation (WG)) by two independent sonographers. D-dimers and sEPCR plasma concentrations were measured using ELISA kits (Enzyme Linked ImmunoSorbent Assay). Results Eleven patients had a PVP. The plasma D-dimer level was positively correlated with placental volume (r = 0.45, p < 0.001). A smaller placental volume and placental quotient was evidenced in women who developed a PVP at the three gestational ages, and the difference was more pronounced during the third exam (20 WG). No obvious correlation could be demonstrated between the development of a PVP and the levels of D-dimer and sEPCR. There was no significant difference in the values of placental volumes measured by the two sonographers. Conclusion The placenta growth could be a major determinant of the elevation of D-dimer during pregnancy. Consideration of placental volume could allow for modulation of the D-dimer concentrations for restoring their clinical interest. PMID:27294274

  3. The role of cytochrome b5 structural domains in interaction with cytochromes P450.

    PubMed

    Sergeev, G V; Gilep, A A; Usanov, S A

    2014-05-01

    To understand the role of the structural elements of cytochrome b5 in its interaction with cytochrome P450 and the catalysis performed by this heme protein, we carried out comparative structural and functional analysis of the two major mammalian forms of membrane-bound cytochrome b5 - microsomal and mitochondrial, designed chimeric forms of the heme proteins in which the hydrophilic domain of one heme protein is replaced by the hydrophilic domain of another one, and investigated the effect of the highly purified native and chimeric heme proteins on the enzymatic activity of recombinant cytochromes P4503A4 and P45017A1 (CYP3A4 and CYP17A1). We show that the presence of a hydrophobic domain in the structure of cytochrome b5 is necessary for its effective interaction with its redox partners, while the nature of the hydrophobic domain has no significant effect on the ability of cytochrome b5 to stimulate the activity of cytochrome P450-catalyzed reactions. Thus, the functional properties of cytochrome b5 are mainly determined by the structure of the heme-binding domain.

  4. Cytochrome c1 exhibits two binding sites for cytochrome c in plants.

    PubMed

    Moreno-Beltrán, Blas; Díaz-Quintana, Antonio; González-Arzola, Katiuska; Velázquez-Campoy, Adrián; De la Rosa, Miguel A; Díaz-Moreno, Irene

    2014-10-01

    In plants, channeling of cytochrome c molecules between complexes III and IV has been purported to shuttle electrons within the supercomplexes instead of carrying electrons by random diffusion across the intermembrane bulk phase. However, the mode plant cytochrome c behaves inside a supercomplex such as the respirasome, formed by complexes I, III and IV, remains obscure from a structural point of view. Here, we report ab-initio Brownian dynamics calculations and nuclear magnetic resonance-driven docking computations showing two binding sites for plant cytochrome c at the head soluble domain of plant cytochrome c1, namely a non-productive (or distal) site with a long heme-to-heme distance and a functional (or proximal) site with the two heme groups close enough as to allow electron transfer. As inferred from isothermal titration calorimetry experiments, the two binding sites exhibit different equilibrium dissociation constants, for both reduced and oxidized species, that are all within the micromolar range, thus revealing the transient nature of such a respiratory complex. Although the docking of cytochrome c at the distal site occurs at the interface between cytochrome c1 and the Rieske subunit, it is fully compatible with the complex III structure. In our model, the extra distal site in complex III could indeed facilitate the functional cytochrome c channeling towards complex IV by building a "floating boat bridge" of cytochrome c molecules (between complexes III and IV) in plant respirasome.

  5. Cytochrome c1 exhibits two binding sites for cytochrome c in plants.

    PubMed

    Moreno-Beltrán, Blas; Díaz-Quintana, Antonio; González-Arzola, Katiuska; Velázquez-Campoy, Adrián; De la Rosa, Miguel A; Díaz-Moreno, Irene

    2014-10-01

    In plants, channeling of cytochrome c molecules between complexes III and IV has been purported to shuttle electrons within the supercomplexes instead of carrying electrons by random diffusion across the intermembrane bulk phase. However, the mode plant cytochrome c behaves inside a supercomplex such as the respirasome, formed by complexes I, III and IV, remains obscure from a structural point of view. Here, we report ab-initio Brownian dynamics calculations and nuclear magnetic resonance-driven docking computations showing two binding sites for plant cytochrome c at the head soluble domain of plant cytochrome c1, namely a non-productive (or distal) site with a long heme-to-heme distance and a functional (or proximal) site with the two heme groups close enough as to allow electron transfer. As inferred from isothermal titration calorimetry experiments, the two binding sites exhibit different equilibrium dissociation constants, for both reduced and oxidized species, that are all within the micromolar range, thus revealing the transient nature of such a respiratory complex. Although the docking of cytochrome c at the distal site occurs at the interface between cytochrome c1 and the Rieske subunit, it is fully compatible with the complex III structure. In our model, the extra distal site in complex III could indeed facilitate the functional cytochrome c channeling towards complex IV by building a "floating boat bridge" of cytochrome c molecules (between complexes III and IV) in plant respirasome. PMID:25091281

  6. The cytochrome bd respiratory oxygen reductases

    PubMed Central

    Borisov, Vitaliy B.; Gennis, Robert B.; Hemp, James; Verkhovsky, Michael I.

    2011-01-01

    Summary Cytochrome bd is a respiratory quinol:O2 oxidoreductase found in many prokaryotes, including a number of pathogens. The main bioenergetic function of the enzyme is the production of a proton motive force by the vectorial charge transfer of protons. The sequences of cytochromes bd are not homologous to those of the other respiratory oxygen reductases, i.e., the heme-copper oxygen reductases or alternative oxidases (AOX). Generally, cytochromes bd are noteworthy for their high affinity for O2 and resistance to inhibition by cyanide. In E. coli, for example, cytochrome bd (specifically, cytochrome bd-I) is expressed under O2-limited conditions. Among the members of the bd-family are the so-called cyanide-insensitive quinol oxidases (CIO) which often have a low content of the eponymous heme d but, instead, have heme b in place of heme d in at least a majority of the enzyme population. However, at this point, no sequence motif has been identified to distinguish cytochrome bd (with a stoichiometric complement of heme d) from an enzyme designated as CIO. Members of the bd-family can be subdivided into those which contain either a long or a short hydrophilic connection between transmembrane helices 6 and 7 in subunit I, designated as the Q-loop. However, it is not clear whether there is a functional consequence of this difference. This review summarizes current knowledge on the physiological functions, genetics, structural and catalytic properties of cytochromes bd. Included in this review are descriptions of the intermediates of the catalytic cycle, the proposed site for the reduction of O2, evidence for a proton channel connecting this active site to the bacterial cytoplasm, and the molecular mechanism by which a membrane potential is generated. PMID:21756872

  7. The cytochrome bd respiratory oxygen reductases.

    PubMed

    Borisov, Vitaliy B; Gennis, Robert B; Hemp, James; Verkhovsky, Michael I

    2011-11-01

    Cytochrome bd is a respiratory quinol: O₂ oxidoreductase found in many prokaryotes, including a number of pathogens. The main bioenergetic function of the enzyme is the production of a proton motive force by the vectorial charge transfer of protons. The sequences of cytochromes bd are not homologous to those of the other respiratory oxygen reductases, i.e., the heme-copper oxygen reductases or alternative oxidases (AOX). Generally, cytochromes bd are noteworthy for their high affinity for O₂ and resistance to inhibition by cyanide. In E. coli, for example, cytochrome bd (specifically, cytochrome bd-I) is expressed under O₂-limited conditions. Among the members of the bd-family are the so-called cyanide-insensitive quinol oxidases (CIO) which often have a low content of the eponymous heme d but, instead, have heme b in place of heme d in at least a majority of the enzyme population. However, at this point, no sequence motif has been identified to distinguish cytochrome bd (with a stoichiometric complement of heme d) from an enzyme designated as CIO. Members of the bd-family can be subdivided into those which contain either a long or a short hydrophilic connection between transmembrane helices 6 and 7 in subunit I, designated as the Q-loop. However, it is not clear whether there is a functional consequence of this difference. This review summarizes current knowledge on the physiological functions, genetics, structural and catalytic properties of cytochromes bd. Included in this review are descriptions of the intermediates of the catalytic cycle, the proposed site for the reduction of O₂, evidence for a proton channel connecting this active site to the bacterial cytoplasm, and the molecular mechanism by which a membrane potential is generated.

  8. Cell-Based High-Throughput Screening for Aromatase Inhibitors in the Tox21 10K Library

    PubMed Central

    Chen, Shiuan; Hsieh, Jui-Hua; Huang, Ruili; Sakamuru, Srilatha; Hsin, Li-Yu; Xia, Menghang; Shockley, Keith R.; Auerbach, Scott; Kanaya, Noriko; Lu, Hannah; Svoboda, Daniel; Witt, Kristine L.; Merrick, B. Alex; Teng, Christina T.; Tice, Raymond R.

    2015-01-01

    Multiple mechanisms exist for endocrine disruption; one nonreceptor-mediated mechanism is via effects on aromatase, an enzyme critical for maintaining the normal in vivo balance of androgens and estrogens. We adapted the AroER tri-screen 96-well assay to 1536-well format to identify potential aromatase inhibitors (AIs) in the U.S. Tox21 10K compound library. In this assay, screening with compound alone identifies estrogen receptor alpha (ERα) agonists, screening in the presence of testosterone (T) identifies AIs and/or ERα antagonists, and screening in the presence of 17β-estradiol (E2) identifies ERα antagonists. Screening the Tox-21 library in the presence of T resulted in finding 302 potential AIs. These compounds, along with 31 known AI actives and inactives, were rescreened using all 3 assay formats. Of the 333 compounds tested, 113 (34%; 63 actives, 50 marginal actives) were considered to be potential AIs independent of cytotoxicity and ER antagonism activity. Structure-activity analysis suggested the presence of both conventional (eg, 1, 2, 4, - triazole class) and novel AI structures. Due to their novel structures, 14 of the 63 potential AI actives, including both drugs and fungicides, were selected for confirmation in the biochemical tritiated water-release aromatase assay. Ten compounds were active in the assay; the remaining 4 were only active in high-throughput screen assay, but with low efficacy. To further characterize these 10 novel AIs, we investigated their binding characteristics. The AroER tri-screen, in high-throughput format, accurately and efficiently identified chemicals in a large and diverse chemical library that selectively interact with aromatase. PMID:26141389

  9. Androgens inhibit aromatase expression through DAX-1: insights into the molecular link between hormone balance and Leydig cancer development.

    PubMed

    Maris, Pamela; Campana, Antonella; Barone, Ines; Giordano, Cinzia; Morelli, Catia; Malivindi, Rocco; Sisci, Diego; Aquila, Saveria; Rago, Vittoria; Bonofiglio, Daniela; Catalano, Stefania; Lanzino, Marilena; Andò, Sebastiano

    2015-04-01

    Leydig cell tumors (LCTs) of the testis are steroid-secreting tumors associated with various steroid biosynthetic abnormalities and endocrine dysfunctions. Despite their overall rarity, LCTs are still of substantial interest owing to the paucity of information regarding their exact nature and malignant potential. In the present study, we disclose the ability of androgens to inhibit Leydig tumor cell proliferation by opposing to self-sufficient in situ estrogen production. In rat Leydig tumor cells, R2C, androgen treatment significantly decreases the expression and the enzymatic activity of cytocrome P450 aromatase, responsible for the local conversion of androgens into estrogens. This inhibitory effect relies on androgen receptor (AR) activation and involves negative regulation of the CYP19 gene transcriptional activity through the nuclear orphan receptor DAX-1 (dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1). Ligand-activated AR up-regulates the expression of DAX-1 and promotes its increased recruitment within the steroidogenic factor-1 site-containing region of the aromatase proximal promoter II in association with the nuclear receptor corepressor. The biological relevance in LCTs of the newly highlighted functional interplay between AR, DAX-1, and aromatase is underlined by our in vivo observations, revealing a marked down-regulation of AR and DAX-1 expression and a strong increase in aromatase levels in testes tissues from old Fischer rats with spontaneously developed Leydig cell neoplasia, compared with normal testes tissues from younger animals. In elucidating a mechanism by which androgens modulate the growth of Leydig tumor cells, our finding support the hypothesis that maintaining the adequate balance between androgen and estrogens may represent the key for blocking estrogen-secreting Leydigioma development, opening new prospects for therapeutic intervention. PMID:25603045

  10. Thermal stability of the polyheme cytochrome c3 superfamily.

    PubMed

    Florens, L; Bianco, P; Haladjian, J; Bruschi, M; Protasevich, I; Makarov, A

    1995-10-16

    The cytochrome c3 superfamily includes Desulfovibrio polyheme cytochromes c. We report the characteristic thermal stability parameters of the Desulfovibrio desulfuricans Norway (D.d.N.) cytochromes c3 (M(r) 13,000 and M(r) 26,000) and the Desulfovibrio vulgaris Hildenborough (D.v.H.) cytochrome c3 (M(r) 13,000) and high molecular mass cytochrome c (Hmc), as obtained with the help of electronic spectroscopy, voltammetric techniques and differential scanning calorimetry. The polyheme cytochromes are denatured over a wide range of temperatures: the D.v.H. cytochrome c3 is highly thermostable (Td = 121 degrees C) contrary to the D.d.N. protein (Td = 73 degrees C). The thermostability of the polyheme cytochromes is redox state dependent. The results are discussed in the light of the structural and functional relationships within the cytochrome c3 superfamily. PMID:7589483

  11. A single intravenous administration of zoledronic acid prevents the bone loss and mechanical compromise induced by aromatase inhibition in rats.

    PubMed

    Gasser, Jürg A; Green, Jonathan R; Shen, Victor; Ingold, Peter; Rebmann, Andrea; Bhatnagar, Ajay S; Evans, Dean B

    2006-10-01

    Recent evidence has demonstrated that long-term estrogen deprivation using aromatase inhibitor therapy in postmenopausal women with breast cancer results in bone loss and increased fracture risk. Bisphosphonates are potent inhibitors of bone resorption and have demonstrated efficacy in preventing bone loss in postmenopausal women with low bone mineral density (BMD) and in patients with breast cancer receiving estrogen deprivation therapy. Therefore, this study investigated the effects of the bisphosphonate zoledronic acid on BMD and bone strength in rats treated with the aromatase inhibitor, letrozole. Peripheral quantitative computed tomography demonstrated that treatment of rats with daily oral letrozole (1 mg/kg) induced significant bone loss and cortical thinning compared with control animals (P < 0.01). A single prior intravenous dose of zoledronic acid dose dependently protected against letrozole-induced bone loss and cortical thinning, with the highest evaluated dose (20 microg/kg) resulting in BMD values that were not significantly different from controls over the 24 weeks of letrozole treatment. Furthermore, biomechanical testing of the distal femoral metaphysis demonstrated that zoledronic acid (20 microg/kg) significantly prevented the decrease in stiffness and elastic modulus induced by letrozole treatment. Taken together, these data support the use of zoledronic acid for the prevention of bone loss in women with breast cancer receiving aromatase inhibitor therapy.

  12. Intracomplex electron transfer between ruthenium-cytochrome c derivatives and cytochrome c1.

    PubMed

    Heacock, D H; Liu, R Q; Yu, C A; Yu, L; Durham, B; Millett, F

    1993-12-25

    The reactions of a beef heart cytochrome c1 preparation containing the hinge protein with horse cytochrome c derivatives labeled at specific lysine amino groups with (dicarboxybipyridine)(bisbipyridine)ruthenium(II) (Ru(II)) were studied by flash photolysis. All of the ruthenium-cytochrome c derivatives formed complexes with cytochrome c1 in low ionic strength buffer (5 mM sodium phosphate, pH 7). Excitation of Ru(II) to Ru(II*) with a 0.4-microseconds laser flash resulted in rapid electron transfer to the ferric heme group in cytochrome c, followed by electron transfer from the ferrous heme group of cytochrome c to the ferric heme group of cytochrome c1. The kinetic difference spectra displayed maxima at 546 nm and minima at 554 nm characteristic of electron transfer between the two cytochromes. The rate constants were independent of concentration at low ionic strength, indicating intracomplex electron transfer. The rate constants were 4,800, 6,800, 22,000, and 22,000 s-1 for cytochrome c derivatives modified at lysines 13, 27, 25, and 72, respectively. The observed rate constants were independent of ionic strength up to about 50 nM and then decreased progressively with further increases in ionic strength indicating dissociation of the complex. Second-order kinetics were observed at 310 mM ionic strength, with rate constants of 1.0 x 10(6), 1.6 x 10(7), 1.2 x 10(8), and 3.0 x 10(7) M-1 s-1 for the derivatives modified at lysines 13, 27, 25, and 72, respectively. The ionic strength dependence of the second-order rate constants is comparable to that involving native horse cytochrome c and is consistent with electron transfer reactions between oppositely charged proteins.

  13. Placental transfer of radiopharmaceuticals and dosimetry in pregnancy

    SciTech Connect

    Russell, J.R.; Stabin, M.G.; Sparks, R.B.

    1999-01-01

    The calculation of radiation dose estimates to the fetus is often important in nuclear medicine. To obtain the best estimates of radiation dose to the fetus, the best biological and physical models should be employed. In this paper, after identification of radiopharmaceuticals often administered to women of childbearing age, the most recent data available on the placental crossover of these radiopharmaceuticals was used (with standard kinetic models describing the maternal distribution and retention and with the best available physical models) to obtain fetal dose estimates for these radiopharmaceuticals were identified as those most commonly administered to women of childbearing years. The literature yielded information on placental crossover of 15 radiopharmaceuticals, from animal or human data. Radiation dose estimates are presented in early pregnancy and at 3-, 6-, and 9-months gestation for these radiopharmaceuticals, as well as for many others used in nuclear medicine (the latter considering only maternal organ contributions to fetal dose). 46 refs., 1 fig., 5 tabs.

  14. Parvovirus infection: an immunohistochemical study using fetal and placental tissue.

    PubMed

    Li, Jing Jing; Henwood, Tony; Van Hal, Sebastian; Charlton, Amanda

    2015-01-01

    Parvovirus B19 infection causes 5% to 15% of cases of nonimmune hydrops fetalis. The aim of our study was to evaluate the use of immunohistochemistry in diagnosing parvovirus infection in fetal and placental tissue during routine fetal and perinatal autopsies. Histology slides of 20 cases of confirmed parvovirus infection were reviewed, and immunohistochemistry was applied to selected blocks of fetal and placental tissue. Immunohistochemistry was positive in all 20 cases, and histologic viral inclusions were seen in 19 cases. Immunohistochemical staining was closely correlated with histology and was more sensitive than histology in detecting virally infected cells, especially in autolyzed tissue. All cases also had confirmatory evidence of parvovirus infection by polymerase chain reaction of fetal liver and positive maternal serology, where it was available. We conclude that parvovirus immunohistochemistry is a reliable method for diagnosing parvovirus infection, especially in autolyzed tissue where histologic assessment may be suboptimal.

  15. The endocannabinoid system: A novel player in human placentation.

    PubMed

    Costa, M A

    2016-06-01

    Cannabis sativa is the most consumed illegal drug around the world. Its consumption during pregnancy is associated with gestational complications, particularly with fetal growth restriction. Endocannabinoids (eCBs) are lipid molecules that act by activating the G-protein coupled cannabinoid receptors, which are also target of the phytocannabinoid Δ(9)-tetrahydrocannabinol (THC). The endocannabinoid system (ECS) participates in distinct biological processes, including pain, inflammation, neuroprotection, and several reproductive events. In addition, an abnormal expression of ECS is associated with infertility and miscarriages. This manuscript will review and discuss the expression of ECS in normal and pathological human placentas, and the role of eCBs and THC in trophoblast proliferation, apoptosis, differentiation, and function. The current evidence points towards a role of ECS in human placentation, shedding light on the contribution of the eCBs in the coordination of human placentation, and in the cellular mechanisms underlying the deleterious effects of cannabis consumption during pregnancy. PMID:26965993

  16. Disease-Modifying Drug Possibly Linked to Placental Insufficiency

    PubMed Central

    Salahudheen, Sultan M.; Begam, Muzibunnisa A.

    2016-01-01

    Disease-modifying drugs (DMDs) such as interferon (IFN)-β and glatiramer acetate are often prescribed to slow disability progression in patients with multiple sclerosis (MS). However, adverse pregnancy outcomes have been reported with these medications. We report the rare occurrence of severe placental complications in a 30-year-old pregnant woman with MS who continued to take IFN-β during her first trimester. She presented at the Tawam Hospital, Al Ain, United Arab Emirates, in 2013 with early-onset fetal growth restriction. At 30 gestational weeks, she developed severe pre-eclampsia. The baby was delivered via emergency Caesarean section and was discharged at the age of two months. Continuation of IFN-β during pregnancy may have contributed to the development of placental insufficiency in this patient. Increased education regarding the risks of DMDs for pregnant patients with MS is very important to ensure successful pregnancy outcomes. PMID:27606121

  17. Disease-Modifying Drug Possibly Linked to Placental Insufficiency

    PubMed Central

    Salahudheen, Sultan M.; Begam, Muzibunnisa A.

    2016-01-01

    Disease-modifying drugs (DMDs) such as interferon (IFN)-β and glatiramer acetate are often prescribed to slow disability progression in patients with multiple sclerosis (MS). However, adverse pregnancy outcomes have been reported with these medications. We report the rare occurrence of severe placental complications in a 30-year-old pregnant woman with MS who continued to take IFN-β during her first trimester. She presented at the Tawam Hospital, Al Ain, United Arab Emirates, in 2013 with early-onset fetal growth restriction. At 30 gestational weeks, she developed severe pre-eclampsia. The baby was delivered via emergency Caesarean section and was discharged at the age of two months. Continuation of IFN-β during pregnancy may have contributed to the development of placental insufficiency in this patient. Increased education regarding the risks of DMDs for pregnant patients with MS is very important to ensure successful pregnancy outcomes.

  18. Label-free photoacoustic microscopy of cytochromes.

    PubMed

    Zhang, Chi; Zhang, Yu Shrike; Yao, Da-Kang; Xia, Younan; Wang, Lihong V

    2013-02-01

    Photoacoustic microscopy (PAM) has achieved submicron lateral resolution in showing subcellular structures; however, relatively few endogenous subcellular contrasts have so far been imaged. Given that the hemeprotein, mostly cytochromes in general cells, is optically absorbing around the Soret peak (~420 nm), we implemented label-free PAM of cytochromes in cytoplasm for the first time. By measuring the photoacoustic spectra of the oxidized and reduced states of fibroblast lysate and fitting the difference spectrum with three types of cytochromes, we found that the three cytochromes account for more than half the optical absorption in the cell lysate at 420 nm wavelength. Fixed fibroblasts on slides were imaged by PAM at 422 and 250 nm wavelengths to reveal cytoplasms and nuclei, respectively, as confirmed by standard staining histology. PAM was also applied to label-free histology of mouse ear sections by showing cytoplasms and nuclei of various cells. PAM of cytochromes in cytoplasm is expected to be a high-throughput, label-free technique for studying live cell functions, which cannot be accomplished by conventional histology.

  19. Yeast mutants overproducing iso-cytochromes c

    SciTech Connect

    Sherman, F.; Cardillo, T.S.; Errede, B.; Friedman, L.; McKnight, G.; Stiles, J.I.

    1980-01-01

    For over 15 years, the iso-cytochrome c system in the yeast Saccharomyces cerevisiae has been used to investigate a multitude of problems in genetics and molecular biology. More recently, attention has been focused on using mutants for examining translation and transcriptional processes and for probing regulatory regions governing gene expression. In an effort to explore regulatory mechanisms and to investigate mutational alterations that lead to increased levels of gene products, we have isolated and characterized mutants that overproduce cytochrome c. In this paper we have briefly summarized background information of some essential features of the iso-cytochrome c system and we have described the types of mutants that overproduce iso-1-cytochrome c or iso-2-cytochrome c. Genetic procedures and recombinant DNA procedures were used to demonstrate that abnormally high amounts of gene products occur in mutants as result of duplications of gene copies or of extended alteration of regulatory regions. The results summarized in this paper point out the requirements of gross mutational changes or rearrangements of chromosomal segments for augmenting gene products.

  20. Cytochrome P450 monooxygenase system in echinoderms.

    PubMed

    den Besten, P J

    1998-11-01

    The results of a limited number of studies on echinoderms provide evidence for the presence of a cytochrome P450 monooxygenase system in representatives of three classes of the phylum Echinodermata: the asteroids (sea stars), holothuroids (sea cucumbers) and echinoids (sea urchins). The monooxygenase system has been demonstrated to be involved in the metabolism of xenobiotic compounds, but is assumed to have its primary function in the metabolism of endogenous substrates, such as steroids. Available data on P450 cofactor requirement, P450-dependent metabolism of benzo[a]pyrene, studies with classical inhibitors of P450, specificity of P450 induction by planar compounds, and the changes in the benzo[a]pyrene metabolite profile in induced animals suggest similarities with the MO system present in vertebrates. However, the relatively high capacity of the monooxygenase system in sea stars to catalyse reactions with organic hydroperoxide as donor for activated oxygen, and the low induceability during exposure to xenobiotics indicate also important differences between the echinoderm cytochrome P450 monooxygenase system and that of vertebrates. Some evidence was found for the existence of different forms of cytochrome P450 in sea stars. Catalytic functions of the cytochrome P450 monooxygenase system of sea stars in the metabolism of steroids may be suppressed as a result of the induction of cytochrome P450 by xenobiotics. PMID:9972455

  1. A microphysiological model of the human placental barrier.

    PubMed

    Blundell, Cassidy; Tess, Emily R; Schanzer, Ariana S R; Coutifaris, Christos; Su, Emily J; Parry, Samuel; Huh, Dongeun

    2016-08-01

    During human pregnancy, the fetal circulation is separated from maternal blood in the placenta by two cell layers - the fetal capillary endothelium and placental trophoblast. This placental barrier plays an essential role in fetal development and health by tightly regulating the exchange of endogenous and exogenous materials between the mother and the fetus. Here we present a microengineered device that provides a novel platform to mimic the structural and functional complexity of this specialized tissue in vitro. Our model is created in a multilayered microfluidic system that enables co-culture of human trophoblast cells and human fetal endothelial cells in a physiologically relevant spatial arrangement to replicate the characteristic architecture of the human placental barrier. We have engineered this co-culture model to induce progressive fusion of trophoblast cells and to form a syncytialized epithelium that resembles the syncytiotrophoblast in vivo. Our system also allows the cultured trophoblasts to form dense microvilli under dynamic flow conditions and to reconstitute expression and physiological localization of membrane transport proteins, such as glucose transporters (GLUTs), critical to the barrier function of the placenta. To provide a proof-of-principle for using this microdevice to recapitulate native function of the placental barrier, we demonstrated physiological transport of glucose across the microengineered maternal-fetal interface. Importantly, the rate of maternal-to-fetal glucose transfer in this system closely approximated that measured in ex vivo perfused human placentas. Our "placenta-on-a-chip" platform represents an important advance in the development of new technologies to model and study the physiological complexity of the human placenta for a wide variety of applications. PMID:27229450

  2. Sources for comparative studies of placentation I. embryological collections.

    PubMed

    Carter, A M

    2008-01-01

    A rich source of material for comparative studies of the placenta is the collections made by pioneers in the field such as H.W. Mossman, A.A.W. Hubrecht and J.P. Hill. This overview gives a brief description of collections known to be available and information on how each can be accessed. Included are some of the major series of human and animal embryos, such as the Boyd and Carnegie collections, as these also house placental material.

  3. Estetrol and utero-placental flow after progesterone load.

    PubMed

    Benassi, L; Alfieri, L; Debiasi, D; Trentadue, R; Salvadori, B

    1982-01-01

    On the basis of recent demonstration in animals of the effect of some hormones on uteroplacental flow, the Authors examined the response of plasmatic Estetrol (15 alpha-hydroxy-estriol) after the administration of progesterone to pregnant women with low Estrogen values. The increase of this compound was related to an improvement of placental function, probably dependent on an increase of available O2, and therefore on uterine blood flow. This can justify a progesterone treatment in such pregnancies. PMID:7168897

  4. Aromatase inhibition in the human male reveals a hypothalamic site of estrogen feedback.

    PubMed

    Hayes, F J; Seminara, S B; Decruz, S; Boepple, P A; Crowley, W F

    2000-09-01

    The preponderance of evidence states that, in adult men, estradiol (E2) inhibits LH secretion by decreasing pulse amplitude and responsiveness to GnRH consistent with a pituitary site of action. However, this conclusion is based on studies that employed pharmacologic doses of sex steroids, used nonselective aromatase inhibitors, and/or were performed in normal (NL) men, a model in which endogenous counterregulatory adaptations to physiologic perturbations confound interpretation of the results. In addition, studies in which estrogen antagonists were administered to NL men demonstrated an increase in LH pulse frequency, suggesting a potential additional hypothalamic site of E2 feedback. To reconcile these conflicting data, we used a selective aromatase inhibitor, anastrozole, to examine the impact of E2 suppression on the hypothalamic-pituitary axis in the male. Parallel studies of NL men and men with idiopathic hypogonadotropic hypogonadism (IHH), whose pituitary-gonadal axis had been normalized with long-term GnRH therapy, were performed to permit precise localization of the site of E2 feedback. In this so-called tandem model, a hypothalamic site of action of sex steroids can thus be inferred whenever there is a difference in the gonadotropin responses of NL and IHH men to alterations in their sex steroid milieu. A selective GnRH antagonist was also used to provide a semiquantitative estimate of endogenous GnRH secretion before and after E2 suppression. Fourteen NL men and seven IHH men were studied. In Exp 1, nine NL and seven IHH men received anastrozole (10 mg/day po x 7 days). Blood samples were drawn daily between 0800 and 1000 h in the NL men and immediately before a GnRH bolus dose in the IHH men. In Exp 2, blood was drawn (every 10 min x 12 h) from nine NL men at baseline and on day 7 of anastrozole. In a subset of five NL men, 5 microg/kg of the Nal-Glu GnRH antagonist was administered on completion of frequent blood sampling, then sampling continued

  5. Affinity Chromatography Purification of Cytochrome c Binding Enzymes

    NASA Astrophysics Data System (ADS)

    Azzi, Angelo; Bill, Kurt; Broger, Clemens

    1982-04-01

    An efficient affinity chromatography procedure for the isolation of mitochondrial cytochrome c oxidase and reductase is described. Saccharomyces cerevisiae cytochrome c was used as a ligand, bound to a thiol-Sepharose 4B gel through cysteine-107. In this way, the site of interaction of cytochrome c with cytochrome oxidase and reductase remained unmodified and available for binding to a number of partner enzymes. The procedure is adequate for the purification of all those proteins having in common the property of binding with high affinity to cytochrome c--e.g., cytochrome c oxidase, reductase, and peroxidase, sulfite oxidase, and reaction centers of photosynthetic bacteria.

  6. Classics revisited. History of reptile placentology: Studiati's early account of placentation in a viviparous lizard.

    PubMed

    Blackburn, Daniel G; Avanzati, Anna Marie; Paulesu, Luana

    2015-11-01

    Although placental diversity in mammals received growing attention in the 1600s through the early 1800s, placentation was not documented in reptiles until the mid-19th century. In his classic 1855 study on a viviparous lizard, Cesare Studiati (University of Pisa) described a structural/functional arrangement of fetal and maternal tissues that meets contemporary criteria for recognition of placentation. Through the fortuitous selection of a highly placentotrophic species, Chalcides chalcides, Studiati recognized the functional role of placental tissues in provision of oxygen as well as nutrients. Although Studiati worked in a pre-evolutionary milieu and without the benefits of histological techniques, his findings revealed that viviparous reptiles could exhibit placental specializations that paralleled those of mammals. Accordingly, his classic paper initiated a highly productive body of research that has continued to the present and highlighted specializations of a species that has figured importantly in placental research.

  7. Classics revisited. History of reptile placentology: Studiati's early account of placentation in a viviparous lizard.

    PubMed

    Blackburn, Daniel G; Avanzati, Anna Marie; Paulesu, Luana

    2015-11-01

    Although placental diversity in mammals received growing attention in the 1600s through the early 1800s, placentation was not documented in reptiles until the mid-19th century. In his classic 1855 study on a viviparous lizard, Cesare Studiati (University of Pisa) described a structural/functional arrangement of fetal and maternal tissues that meets contemporary criteria for recognition of placentation. Through the fortuitous selection of a highly placentotrophic species, Chalcides chalcides, Studiati recognized the functional role of placental tissues in provision of oxygen as well as nutrients. Although Studiati worked in a pre-evolutionary milieu and without the benefits of histological techniques, his findings revealed that viviparous reptiles could exhibit placental specializations that paralleled those of mammals. Accordingly, his classic paper initiated a highly productive body of research that has continued to the present and highlighted specializations of a species that has figured importantly in placental research. PMID:26474917

  8. Placental Microbiome and Its Role in Preterm Birth

    PubMed Central

    Cao, Bin; Stout, Molly J.; Lee, Iris; Mysorekar, Indira U.

    2015-01-01

    Despite the well-known fact that the placenta has long-term effects on maternal and fetal health, the placenta remains a poorly understood and understudied organ. Not only is the placenta a site of exchange of nutrients and blood and gases between the fetal and maternal systems, but it also performs critical metabolic functions for supporting fetal development and maintaining maternal-fetal tolerance. It is also abundantly clear that impairment of placental function leads to severe pregnancy complications, including preterm birth (PTB), a significant cause of perinatal mortality and morbidity worldwide. Understanding the causes of PTB and other adverse outcomes is clearly essential for the development of effective methods of prevention and treatment. We focus our review of one major known cause of PTB, namely, infection. We also introduce a new and somewhat unexpected factor(s) that may well affect PTB and every aspect of placental biology and function: the placental microbiome. We discuss the implications of the placenta housing a microbial biomass for PTB and the effect of maternal microbiomes at various niches for fetal colonization and health outcomes. We suggest that the placenta is an integral part of the pipeline for microbe-powered driver of fetal destiny. PMID:25635174

  9. Human Placental Histopathology in Preterm Stillbirth: One Center's Experience.

    PubMed

    Salihoğlu, Özgül; Doğan, Keziban; Sever, Nurten; Oksay, Sinem Can; Yaşar, Levent

    2016-01-01

    Our aim is to identify maternal risk factors and to determine placental histopathologies in preterm stillbirths. We designed a prospective study involving a patient population (n = 136) composed of singleton stillbirth (n = 40) and singleton live-born neonates (n = 96) between 23 0/7 and 36 6/7 weeks of gestation. We divided the stillbirths into groups of early (n = 21) and late (n = 19) stillbirths. Statistical analyses were performed using SPSS version 15 software. Small birth weight for gestational age and oligo-anhydramnios were significantly higher in the early stillbirth group (p = 0.001, p = 0.002 respectively). Antenatal follow up was significantly lower in the late stillbirth group (p = 0.001). Placental weight was statistically lower in the early stillbirth group (p = 0.001). We found no significant differences in maternal vascular underperfusion, fetal vascular obstruction, inflammation and villitis of unknown etiology. Placental pathologies causing preterm labor may play an important role in the etiology of stillbirths and antenatal follow up is essential for each pregnancy. PMID:27159738

  10. Good practices in collecting umbilical cord and placental blood 1

    PubMed Central

    Lopes, Lauren Auer; Bernardino, Elizabeth; Crozeta, Karla; Guimarães, Paulo Ricardo Bittencourt

    2016-01-01

    Abstract Objective: to identify the factors related to the quality of umbilical cord and placental blood specimens, and define best practices for their collection in a government bank of umbilical cord and placental blood. Method: this was a descriptive study, quantitative approach, performed at a government umbilical cord and placental blood bank, in two steps: 1) verification of the obstetric, neonatal and operational factors, using a specific tool for gathering data as non-participant observers; 2) definition of best practices by grouping non-conformities observed before, during and after blood collection. The data was analyzed using descriptive statistics and the following statistical software: Statistica(r) and R(r). Results: while there was a correlation with obstetrical and neonatal factors, there was a larger correlation with operational factors, resulting in the need to adjust the professional practices of the nursing staff and obstetrical team involved in collecting this type of blood. Based on these non-conformities we defined best practices for nurses before, during and after blood collection. Conclusion: the best practices defined in this study are an important management tool for the work of nurses in obtaining blood specimens of high cell quality. PMID:27556876

  11. Geomolecular Dating and the Origin of Placental Mammals.

    PubMed

    Phillips, Matthew J

    2016-05-01

    In modern evolutionary divergence analysis the role of geological information extends beyond providing a timescale, to informing molecular rate variation across the tree. Here I consider the implications of this development. I use fossil calibrations to test the accuracy of models of molecular rate evolution for placental mammals, and reveal substantial misspecification associated with life history rate correlates. Adding further calibrations to reduce dating errors at specific nodes unfortunately tends to transfer underlying rate errors to adjacent branches. Thus, tight calibration across the tree is vital to buffer against rate model errors. I argue that this must include allowing maximum bounds to be tight when good fossil records permit, otherwise divergences deep in the tree will tend to be inflated by the interaction of rate errors and asymmetric confidence in minimum and maximum bounds. In the case of placental mammals I sought to reduce the potential for transferring calibration and rate model errors across the tree by focusing on well-supported calibrations with appropriately conservative maximum bounds. The resulting divergence estimates are younger than others published recently, and provide the long-anticipated molecular signature for the placental mammal radiation observed in the fossil record near the 66 Ma Cretaceous-Paleogene extinction event.

  12. Glucose metabolism in pregnant sheep when placental growth is restricted

    SciTech Connect

    Owens, J.A.; Falconer, J.; Robinson, J.S. )

    1989-08-01

    The effect of restricting placental growth on glucose metabolism in pregnant sheep in late gestation was determined by primed constant infusions of D-(U-{sup 14}C)- and D-(2-{sup 3}H)glucose and antipyrine into fetuses of six control sheep and six sheep from which endometrial caruncles had been removed before pregnancy (caruncle sheep). In the latter, placental and fetal weights were reduced, as was the concentration of glucose in fetal arterial blood. Fetal glucose turnover in caruncle sheep was only 52-59% of that in controls, largely because of lower umbilical loss of glucose back to the placenta (38-39% of control) and lower fetal glucose utilization (61-74% of control). However, fetal glucose utilization on a weight-specific basis was similar in control and caruncle sheep. Significant endogenous glucose production occurred in control and caruncle fetal sheep. Maternal glucose production and partition of glucose between the gravid uterus and other maternal tissues were similar in control and caruncle sheep. In conclusion, when placental and fetal growth are restricted, fetal glucose utilization is maintained by reduced loss of glucose back to the placenta and mother and by maintaining endogenous glucose production.

  13. Geomolecular Dating and the Origin of Placental Mammals.

    PubMed

    Phillips, Matthew J

    2016-05-01

    In modern evolutionary divergence analysis the role of geological information extends beyond providing a timescale, to informing molecular rate variation across the tree. Here I consider the implications of this development. I use fossil calibrations to test the accuracy of models of molecular rate evolution for placental mammals, and reveal substantial misspecification associated with life history rate correlates. Adding further calibrations to reduce dating errors at specific nodes unfortunately tends to transfer underlying rate errors to adjacent branches. Thus, tight calibration across the tree is vital to buffer against rate model errors. I argue that this must include allowing maximum bounds to be tight when good fossil records permit, otherwise divergences deep in the tree will tend to be inflated by the interaction of rate errors and asymmetric confidence in minimum and maximum bounds. In the case of placental mammals I sought to reduce the potential for transferring calibration and rate model errors across the tree by focusing on well-supported calibrations with appropriately conservative maximum bounds. The resulting divergence estimates are younger than others published recently, and provide the long-anticipated molecular signature for the placental mammal radiation observed in the fossil record near the 66 Ma Cretaceous-Paleogene extinction event. PMID:26658702

  14. AroER Tri-Screen Is a Biologically Relevant Assay for Endocrine Disrupting Chemicals Modulating the Activity of Aromatase and/or the Estrogen Receptor

    PubMed Central

    Chen, Shiuan; Zhou, Dujin; Hsin, Li-Yu; Kanaya, Noriko; Wong, Cynthie; Yip, Richard; Sakamuru, Srilatha; Xia, Menghang; Yuan, Yate-Ching; Witt, Kristine; Teng, Christina

    2014-01-01

    Endocrine disrupting chemicals (EDCs) interfere with the biosynthesis, metabolism, and functions of steroid hormones, including estrogens and androgens. Aromatase enzyme converts androgen to estrogen. Thus, EDCs against aromatase significantly impact estrogen- and/or androgen-dependent functions, including the development of breast cancer. The current study aimed to develop a biologically relevant cell-based high-throughput screening assay to identify EDCs that act as aromatase inhibitors (AIs), estrogen receptor (ER) agonists, and/or ER antagonists. The AroER tri-screen assay was developed by stable transfection of ER-positive, aromatase-expressing MCF-7 breast cancer cells with an estrogen responsive element (ERE) driven luciferase reporter plasmid. The AroER tri-screen can identify: estrogenic EDCs, which increase luciferase signal without 17β-estradiol (E2); anti-estrogenic EDCs, which inhibit the E2-induced luciferase signal; and AI-like EDCs, which suppress a testosterone-induced luciferase signal. The assay was first optimized in a 96-well plate format and then miniaturized into a 1536-well plate format. The AroER tri-screen was demonstrated to be suitable for high-throughput screening in the 1536-well plate format, with a 6.9-fold signal-to-background ratio, a 5.4% coefficient of variation, and a screening window coefficient (Z-factor) of 0.78. The assay suggested that bisphenol A (BPA) functions mainly as an ER agonist. Results from screening the 446 drugs in the National Institutes of Health Clinical Collection revealed 106 compounds that modulated ER and/or aromatase activities. Among these, two AIs (bifonazole and oxiconazole) and one ER agonist (paroxetine) were confirmed through alternative aromatase and ER activity assays. These findings indicate that AroER tri-screen is a useful high-throughput screening system for identifying ER ligands and aromatase-inhibiting chemicals. PMID:24496634

  15. Aromatase and comparative response to its inhibitors in two types of endometrial cancer.

    PubMed

    Berstein, L; Kovalevskij, A; Zimarina, T; Maximov, S; Gershfeld, E; Vasilyev, D; Baisheva, S; Baymakhasheva, A; Thijssen, J H H

    2005-05-01

    Aromatase activity (AA) was evaluated totally in 80 tumors collected from primary endometrial cancer (EC) patients. All patients were divided into cases belonging to the types I or II of EC (respectively, 50 and 30 observations). Samples of malignant endometrium from type II demonstrated inclination to the higher AA in comparison with type I samples; the difference reached level of statistical significance in non-smoking patients (p=0.02). Although no positive correlation was revealed between AA in EC tissue and percentage of cells with DNA damage in normal endometrium from the same patients, the rate of DNA damage (percent of comets, comet's tail average length, etc.) was higher in intact endometrium collected from patients with type II of the disease. In 19 tumor samples, CYP19 gene expression was evaluated by RT-PCR and level of mRNA signal demonstrated positive correlation with AA (R(s)=+0.63, p=0.05) in the whole this material. Of note, though, CYP19 mRNA expression was not revealed in six cases, and all of them belonged to the type I of disease. Finally, in 23 EC patients (15 with type I and 8 with type II of the disease) effects of 2 weeks treatment with letrozole (10 pts) and exemestane (13 pts) were evaluated in neoadjuvant setting. Although diminishing of endometrial M-echo signal and the increases in FSH and LH concentration after treatment were more pronounced in type I patients, decrease in tumor PR content (p=0.04) was more revealing in patients with type II of EC; besides, the decreases in AA in tumor tissue by the end of treatment were noted predominantly in patients with lower body weight (BMI <27.5). Thus, although type II of EC is frequently considered as hormone-independent, increased ability of this type of the tumor to estrogen biosynthesis (at CYP19 gene and protein level) may lead to the reconsideration of such conclusion and warrants further investigation. The search of possible ethnic differences in AA and in the biologic response to

  16. Use of Placental Membranes for the Treatment of Chronic Diabetic Foot Ulcers

    PubMed Central

    Brantley, Jonathan N.; Verla, Thomas D.

    2015-01-01

    Significance: Chronic diabetic foot ulcers (DFUs) remain a challenge for physicians to treat. High mortality rates for DFU patients have pointed to the low effectiveness of standard care and lack of quality wound care products. The composition (collagen-rich tissue matrix and endogenous growth factors and cells) and functional properties (anti-inflammatory, anti-bacterial, and angiogenic) of placental membranes are uniquely suited to address the needs of chronic wounds. This led to the commercialization of placental membranes, which are now widely available to physicians as a new advanced wound treatment option. Recent Advances: Progress in tissue processing and preservation methods has facilitated the development of placental products for wounds. Currently, a variety of commercial placental products are available to physicians for the treatment of chronic DFUs and other wounds. This review summarizes the key factors that negatively impact DFU healing (including social factors, such as smoking, vascular deficiencies, hyperglycemia, and other metabolic abnormalities), describes the structure and biology of placental membranes, and overviews commercially available placental products for wounds and data from the most recent DFU clinical trials utilizing commercial placental membranes. Critical Issues: Although the effects of diabetes on wound healing are complex and not fully understood, some of the key factors and pathways that interfere with healing have been identified. However, a multidisciplinary approach for the assessment of patients with chronic DFUs and guidelines for selection of appropriate treatment modalities remain to be implemented. Future Directions: The biological properties of placental membranes show benefits for the treatment of chronic DFUs, but scientific and clinical data for commercially available placental products are limited. Therefore, we need (1) more randomized, controlled clinical trials for commercial placental products; (2) studies

  17. Definitions and reporting of placental insufficiency in biomedical journals: a review of the literature.

    PubMed

    Hunt, Kathryn; Kennedy, Stephen H; Vatish, Manu

    2016-10-01

    Placental insufficiency is a major problem worldwide for both mothers and babies. However, we have demonstrated in a review of the biomedical literature, that both the terminology used to describe, and techniques used to measure suboptimal placental function, are remarkably varied and inconsistent in both clinical and scientific studies. We, therefore, present a case for the development of a standardised approach to studying placental insufficiency. PMID:27591716

  18. Disease-Modifying Drug Possibly Linked to Placental Insufficiency: Severe placental complications in a pregnant woman with multiple sclerosis.

    PubMed

    Salahudheen, Sultan M; Begam, Muzibunnisa A

    2016-08-01

    Disease-modifying drugs (DMDs) such as interferon (IFN)-β and glatiramer acetate are often prescribed to slow disability progression in patients with multiple sclerosis (MS). However, adverse pregnancy outcomes have been reported with these medications. We report the rare occurrence of severe placental complications in a 30-year-old pregnant woman with MS who continued to take IFN-β during her first trimester. She presented at the Tawam Hospital, Al Ain, United Arab Emirates, in 2013 with early-onset fetal growth restriction. At 30 gestational weeks, she developed severe pre-eclampsia. The baby was delivered via emergency Caesarean section and was discharged at the age of two months. Continuation of IFN-β during pregnancy may have contributed to the development of placental insufficiency in this patient. Increased education regarding the risks of DMDs for pregnant patients with MS is very important to ensure successful pregnancy outcomes. PMID:27606121

  19. Two-dimensional crystallization of monomeric bovine cytochrome c oxidase with bound cytochrome c in reconstituted lipid membranes

    PubMed Central

    Osuda, Yukiho; Shinzawa-Itoh, Kyoko; Tani, Kazutoshi; Maeda, Shintaro; Yoshikawa, Shinya; Tsukihara, Tomitake; Gerle, Christoph

    2016-01-01

    Mitochondrial cytochrome c oxidase utilizes electrons provided by cytochrome c for the active vectorial transport of protons across the inner mitochondrial membrane through the reduction of molecular oxygen to water. Direct structural evidence on the transient cytochrome c oxidase–cytochrome c complex thus far, however, remains elusive and its physiological relevant oligomeric form is unclear. Here, we report on the 2D crystallization of monomeric bovine cytochrome c oxidase with tightly bound cytochrome c at a molar ratio of 1:1 in reconstituted lipid membranes at the basic pH of 8.5 and low ionic strength. PMID:26754561

  20. Placental expression profile of imprinted genes impacts birth weight

    PubMed Central

    Kappil, Maya A; Green, Benjamin B; Armstrong, David A; Sharp, Andrew J; Lambertini, Luca; Marsit, Carmen J; Chen, Jia

    2015-01-01

    The importance of imprinted genes in regulating feto-placental development has been long established. However, a comprehensive assessment of the role of placental imprinted gene expression on fetal growth has yet to be conducted. In this study, we examined the association between the placental expression of 108 established and putative imprinted genes and birth weight in 677 term pregnancies, oversampled for small for gestational age (SGA) and large for gestational age (LGA) infants. Using adjusted multinomial regression analyses, a 2-fold increase in the expression of 9 imprinted genes was positively associated with LGA status: BLCAP [odds ratio (OR) = 3.78, 95% confidence interval (CI): 1.83, 7.82], DLK1 [OR = 1.63, 95% CI: 1.27, 2.09], H19 [OR = 2.79, 95% CI: 1.77, 4.42], IGF2 [OR = 1.43, 95% CI:1.31, 2.40], MEG3 [OR = 1.42, 95% CI: 1.19, 1.71], MEST [OR = 4.78, 95% CI: 2.64, 8.65], NNAT [OR = 1.40, 95% CI: 1.05, 1.86], NDN [OR = 2.52, 95% CI: 1.72, 3.68], and PLAGL1 [OR = 1.85, 95% CI: 1.40, 2.44]. For SGA status, a 2-fold increase in MEST expression was associated with decreased risk [OR = 0.31, 95% CI: 0.17, 0.58], while a 2-fold increase in NNAT expression was associated with increased risk [OR = 1.52, 95% CI: 1.1, 2.1]. Following a factor analysis, all genes significantly associated with SGA or LGA status loaded onto 2 of the 8 gene-sets underlying the variability in the dataset. Our comprehensive placental profiling of imprinted genes in a large birth cohort supports the importance of these genes for fetal growth. Given that abnormal birth weight is implicated in numerous diseases and developmental abnormalities, the expression pattern of placental imprinted genes has the potential to be developed as a novel biomarker for postnatal health outcomes. PMID:26186239

  1. Review: Exploration of placentation from human beings to ocean-living species.

    PubMed

    Soma, H; Murai, N; Tanaka, K; Oguro, T; Kokuba, H; Yoshihama, I; Fujita, K; Mineo, S; Toda, M; Uchida, S; Mogoe, T

    2013-03-01

    This review covers four topics. 1) Placental pathology in Himalayan mountain people. To determine morphological changes of the placenta at high altitude, pathological examination was made of 1000 Himalayan placentas obtained in Nepal and Tibet and the results compared with Japanese placentas delivered at sea level. Characteristic findings in the placental villi of the Himalayan group included high incidences of villous chorangiosis and chorangioma. These processes were clarified by ultrastructural observation. 2) Placentation in Sirenians. The giant Takikawa sea cow, which lived 5 million years ago, was discovered on Hokkaido, Japan. It was an ancestor of the dugong as well as the manatees. Sirenia, the sea cow group, shares a common ancestor with Proboscidea, the elephants, even though they now inhabit quite different environments. A comparison was made of their zonary endothelial type of placentation. 3) Placentation in sharks and rays. The remarkable placentation of hammerhead sharks and manta rays is described. 4) Placentation in the Antarctic minke whale. Placental tissue samples of this whale were obtained from the Japan Institute of Cetacean Research. In an ultrastructural study of the utero-placental junction, microfilamental processes of the allantochorionic zone and crypt formation were visualized.

  2. Determination of placental weight using two-dimensional sonography and volumetric mathematic modeling.

    PubMed

    Azpurua, Humberto; Funai, Edmund F; Coraluzzi, Luisa M; Doherty, Leo F; Sasson, Isaac E; Kliman, Merwin; Kliman, Harvey J

    2010-02-01

    An abnormally decreased placental weight has been linked to increased perinatal complications, including intrauterine fetal demise (IUFD) and fetal growth restriction (IUGR). Despite its promise, determining placental weight prenatally using three-dimensional systems is time-consuming and requires expensive technology and expertise. We propose a novel method using two-dimensional sonography that provides an immediate estimation of placental volume. Placental volume was calculated in 29 third-trimester pregnancies using linear measurements of placental width, height, and thickness to calculate the convex-concave shell volume within 24 hours of birth. Data were analyzed to calculate Spearman's rho (r (s)) and significance. There was a significant correlation between estimated placental volume (EPV) and actual placental weight (r (s) = 0.80, P < 0.001). Subgroup analysis of preterm gestations ( N = 14) revealed an even more significant correlation of EPV to actual placental weight (r (s) = 0.89, P < 0.001). Placental weight can be accurately predicted by two-dimensional ultrasound with volumetric calculations. This method is simple, rapid, and accurate, making it practical for routine prenatal care, as well as for high-risk cases with decreased fetal movement and IUGR. Routine EPV surveillance may decrease the rates of perinatal complications and unexpected IUFD. PMID:19653142

  3. Review: Exploration of placentation from human beings to ocean-living species.

    PubMed

    Soma, H; Murai, N; Tanaka, K; Oguro, T; Kokuba, H; Yoshihama, I; Fujita, K; Mineo, S; Toda, M; Uchida, S; Mogoe, T

    2013-03-01

    This review covers four topics. 1) Placental pathology in Himalayan mountain people. To determine morphological changes of the placenta at high altitude, pathological examination was made of 1000 Himalayan placentas obtained in Nepal and Tibet and the results compared with Japanese placentas delivered at sea level. Characteristic findings in the placental villi of the Himalayan group included high incidences of villous chorangiosis and chorangioma. These processes were clarified by ultrastructural observation. 2) Placentation in Sirenians. The giant Takikawa sea cow, which lived 5 million years ago, was discovered on Hokkaido, Japan. It was an ancestor of the dugong as well as the manatees. Sirenia, the sea cow group, shares a common ancestor with Proboscidea, the elephants, even though they now inhabit quite different environments. A comparison was made of their zonary endothelial type of placentation. 3) Placentation in sharks and rays. The remarkable placentation of hammerhead sharks and manta rays is described. 4) Placentation in the Antarctic minke whale. Placental tissue samples of this whale were obtained from the Japan Institute of Cetacean Research. In an ultrastructural study of the utero-placental junction, microfilamental processes of the allantochorionic zone and crypt formation were visualized. PMID:23332416

  4. Two natural products, trans-phytol and (22E)-ergosta-6,9,22-triene-3β,5α,8α-triol, inhibit the biosynthesis of estrogen in human ovarian granulosa cells by aromatase (CYP19).

    PubMed

    Guo, Jiajia; Yuan, Yun; Lu, Danfeng; Du, Baowen; Xiong, Liang; Shi, Jiangong; Yang, Lijuan; Liu, Wanli; Yuan, Xiaohong; Zhang, Guolin; Wang, Fei

    2014-08-15

    Aromatase is the only enzyme in vertebrates to catalyze the biosynthesis of estrogens. Although inhibitors of aromatase have been developed for the treatment of estrogen-dependent breast cancer, the whole-body inhibition of aromatase causes severe adverse effects. Thus, tissue-selective aromatase inhibitors are important for the treatment of estrogen-dependent cancers. In this study, 63 natural products with diverse structures were examined for their effects on estrogen biosynthesis in human ovarian granulosa-like KGN cells. Two compounds-trans-phytol (SA-20) and (22E)-ergosta-6,9,22-triene-3β,5α,8α-triol (SA-48)-were found to potently inhibit estrogen biosynthesis (IC50: 1μM and 0.5μM, respectively). Both compounds decreased aromatase mRNA and protein expression levels in KGN cells, but had no effect on the aromatase catalytic activity in aromatase-overexpressing HEK293A cells and recombinant expressed aromatase. The two compounds decreased the expression of aromatase promoter I.3/II. Neither compound affected intracellular cyclic AMP (cAMP) levels, but they inhibited the phosphorylation or protein expression of cAMP response element-binding protein (CREB). The effects of these two compounds on extracellular regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinases (MAPKs), and AKT/phosphoinositide 3-kinase (PI3K) pathway were examined. Inhibition of p38 MAPK could be the mechanism underpinning the actions of these compounds. Our results suggests that natural products structurally similar to SA-20 and SA-48 may be a new source of tissue-selective aromatase modulators, and that p38 MAPK is important in the basal control of aromatase in ovarian granulosa cells. SA-20 and SA-48 warrant further investigation as new pharmaceutical tools for the prevention and treatment of estrogen-dependent cancers. PMID:24853760

  5. Reactive Intermediates in Cytochrome P450 Catalysis*

    PubMed Central

    Krest, Courtney M.; Onderko, Elizabeth L.; Yosca, Timothy H.; Calixto, Julio C.; Karp, Richard F.; Livada, Jovan; Rittle, Jonathan; Green, Michael T.

    2013-01-01

    Recently, we reported the spectroscopic and kinetic characterizations of cytochrome P450 compound I in CYP119A1, effectively closing the catalytic cycle of cytochrome P450-mediated hydroxylations. In this minireview, we focus on the developments that made this breakthrough possible. We examine the importance of enzyme purification in the quest for reactive intermediates and report the preparation of compound I in a second P450 (P450ST). In an effort to bring clarity to the field, we also examine the validity of controversial reports claiming the production of P450 compound I through the use of peroxynitrite and laser flash photolysis. PMID:23632017

  6. Genetic characterization of Bagarius species using cytochrome c oxidase I and cytochrome b genes.

    PubMed

    Nagarajan, Muniyandi; Raja, Manikam; Vikram, Potnuru

    2016-09-01

    In this study, we first inferred the genetic variability of two Bagarius bagarius populations collected from Ganges and Brahmaputra rivers of India using two mtDNA markers. Sequence analysis of COI gene did not show significant differences between two populations whereas cytochrome b gene showed significant differences between two populations. Followed by, genetic relationship of B. bagarius and B. yarrielli was analyzed using COI and cytochrome b gene and the results showed a higher level genetic variation between two species. The present study provides support for the suitability of COI and cytochrome b genes for the identification of B. bagarius and B. yarrielli.

  7. Aromatase inhibition remodels the clonal architecture of estrogen-receptor-positive breast cancers

    PubMed Central

    Miller, Christopher A.; Gindin, Yevgeniy; Lu, Charles; Griffith, Obi L; Griffith, Malachi; Shen, Dong; Hoog, Jeremy; Li, Tiandao; Larson, David E.; Watson, Mark; Davies, Sherri R; Hunt, Kelly; Suman, Vera J.; Snider, Jacqueline; Walsh, Thomas; Colditz, Graham A.; DeSchryver, Katherine; Wilson, Richard K.; Mardis, Elaine R.; Ellis, Matthew J.

    2016-01-01

    Resistance to oestrogen-deprivation therapy is common in oestrogen-receptor-positive (ER+) breast cancer. To better understand the contributions of tumour heterogeneity and evolution to resistance, here we perform comprehensive genomic characterization of 22 primary tumours sampled before and after 4 months of neoadjuvant aromatase inhibitor (NAI) treatment. Comparing whole-genome sequencing of tumour/normal pairs from the two time points, with coincident tumour RNA sequencing, reveals widespread spatial and temporal heterogeneity, with marked remodelling of the clonal landscape in response to NAI. Two cases have genomic evidence of two independent tumours, most obviously an ER− ‘collision tumour', which was only detected after NAI treatment of baseline ER+ disease. Many mutations are newly detected or enriched post treatment, including two ligand-binding domain mutations in ESR1. The observed clonal complexity of the ER+ breast cancer genome suggests that precision medicine approaches based on genomic analysis of a single specimen are likely insufficient to capture all clinically significant information. PMID:27502118

  8. Improving compliance and persistence to adjuvant tamoxifen and aromatase inhibitor therapy.

    PubMed

    Hadji, Peyman

    2010-02-01

    Better compliance and persistence with therapy are associated with improved patient outcomes. As more and more patients survive breast cancer, compliance with adjuvant therapy becomes increasingly important. In clinical trials, compliance with adjuvant endocrine therapy among women with breast cancer is usually high. Retrospective analyses of databases and medical records from clinical practice, insurance databases of prescription refills, and survey data show a significant decrease in persistence after 12 months of therapy. With ongoing therapy, a further decline in persistence of up to 50% has been reported. A consistent methodology is needed to measure patient behavior and identify patients who are not adhering to therapy. Promising strategies for enhancing adherence to treatment in clinical practice include improving access to health care, increasing patient satisfaction, managing side effects, patient education, and better communication between the patient and health care provider. Positive relationships between patients and their health care providers, and frequent monitoring and feedback, may be most effective. While the lack of conformity across studies in measuring makes cross-study comparisons difficult, this review evaluates the available data regarding compliance and persistence with adjuvant endocrine therapies for breast cancer (tamoxifen and aromatase inhibitors) and presents strategies for improving adherence.

  9. Drug withdrawal in women with progressive metastatic breast cancer while on aromatase inhibitor therapy

    PubMed Central

    Chavarri-Guerra, Y; Higgins, M J; Szymonifka, J; Cigler, T; Liedke, P; Partridge, A; Ligibel, J; Come, S E; Finkelstein, D; Ryan, P D; Goss, P E

    2014-01-01

    Background: Acquiring resistance to endocrine therapy is common in metastatic hormone-receptor-positive breast cancer (MBC). These patients most often transition either to next-line endocrine therapy or to systemic chemotherapy. However, withdrawal of endocrine therapy and observation as is selectively practiced in prostate cancer is another potential strategy for breast cancer patients. Methods: A prospective, single-arm phase II trial of aromatase inhibitor (AI) withdrawal was performed in women with MBC, who had disease progression on AI therapy. The primary objective was to estimate the clinical benefit rate (defined as complete or partial response, or stable disease for at least 24 weeks, by RECIST criteria). Participants were monitored clinically and radiographically off all therapy at 8, 16 and 24 weeks after treatment and every 12 weeks thereafter until disease progression. Results: Twenty-four patients (of 40 intended) were enrolled when the study was closed due to slow accrual. Clinical benefit rate overall was 46% (95% CI 26% to 67%). Median progression-free survival from time of AI withdrawal was 4 months. Two patients have remained progression free, off all treatment, for over 60 months. Conclusions: Despite suboptimal patient accrual, our results suggest that selected patients with metastatic breast cancer progressing on AI therapy can experience disease stabilisation and a period of observation after AI withdrawal. A randomised phase II trial is planned. PMID:25233398

  10. Vaginal estrogen products in hormone receptor-positive breast cancer patients on aromatase inhibitor therapy.

    PubMed

    Sulaica, Elisabeth; Han, Tiffany; Wang, Weiqun; Bhat, Raksha; Trivedi, Meghana V; Niravath, Polly

    2016-06-01

    Atrophic vaginitis represents a major barrier to compliance with aromatase inhibitor (AI) therapy in breast cancer (BC) survivors. While local estrogen therapy is effective for postmenopausal vaginal dryness, the efficacy of such therapies has not been evaluated systematically in hormone receptor-positive (HR+) BC patients on AI therapy. Furthermore, the potential risk of breast cancer recurrence with vaginal estrogen therapy represents a long-term safety concern for the patients with HR + BC. Unfortunately, there is no standardized assay to measure very low concentrations of estradiol (E2) in these women being treated with AI therapy. This makes it difficult to evaluate even indirectly the potential risk of BC recurrence with vaginal estrogen therapy in HR + BC patients on AI therapy. In this review, we describe available assays to measure very low concentrations of E2, discuss the Food and Drug Administration-approved vaginal estrogen products on the market, and summarize published and ongoing clinical trials evaluating the safety and efficacy of vaginal estrogen in HR + BC patients on AI therapy. In the absence of any randomized controlled clinical trials, this review serves as a summary of available clinical data and ongoing studies to aid clinicians in selecting the best available option for their patients.

  11. Aromatase inhibition remodels the clonal architecture of estrogen-receptor-positive breast cancers.

    PubMed

    Miller, Christopher A; Gindin, Yevgeniy; Lu, Charles; Griffith, Obi L; Griffith, Malachi; Shen, Dong; Hoog, Jeremy; Li, Tiandao; Larson, David E; Watson, Mark; Davies, Sherri R; Hunt, Kelly; Suman, Vera J; Snider, Jacqueline; Walsh, Thomas; Colditz, Graham A; DeSchryver, Katherine; Wilson, Richard K; Mardis, Elaine R; Ellis, Matthew J

    2016-01-01

    Resistance to oestrogen-deprivation therapy is common in oestrogen-receptor-positive (ER+) breast cancer. To better understand the contributions of tumour heterogeneity and evolution to resistance, here we perform comprehensive genomic characterization of 22 primary tumours sampled before and after 4 months of neoadjuvant aromatase inhibitor (NAI) treatment. Comparing whole-genome sequencing of tumour/normal pairs from the two time points, with coincident tumour RNA sequencing, reveals widespread spatial and temporal heterogeneity, with marked remodelling of the clonal landscape in response to NAI. Two cases have genomic evidence of two independent tumours, most obviously an ER- 'collision tumour', which was only detected after NAI treatment of baseline ER+ disease. Many mutations are newly detected or enriched post treatment, including two ligand-binding domain mutations in ESR1. The observed clonal complexity of the ER+ breast cancer genome suggests that precision medicine approaches based on genomic analysis of a single specimen are likely insufficient to capture all clinically significant information. PMID:27502118

  12. Genetic Associations With Toxicity-related Discontinuation of Aromatase Inhibitor Therapy for Breast Cancer

    PubMed Central

    Henry, N. Lynn; Skaar, Todd C.; Dantzer, Jessica; Li, Lang; Kidwell, Kelley; Gersch, Christina; Nguyen, Anne T.; Rae, James M.; Desta, Zeruesenay; Oesterreich, Steffi; Philips, Santosh; Carpenter, Janet S.; Storniolo, Anna M.; Stearns, Vered; Hayes, Daniel F.; Flockhart, David A.

    2013-01-01

    Background Up to 25% of patients discontinue adjuvant aromatase inhibitor (AI) therapy due to intolerable symptoms. Predictors of which patients will be unable to tolerate these medications have not been defined. We hypothesized that inherited variants in candidate genes are associated with treatment discontinuation because of AI-associated toxicity. Methods We prospectively evaluated reasons for treatment discontinuation in women with hormone receptor-positive breast cancer initiating adjuvant AI through a multicenter, prospective, randomized clinical trial of exemestane versus letrozole. Using multiple genetic models, we evaluated potential associations between discontinuation of AI therapy because of toxicity and 138 variants in 24 candidate genes, selected a priori, primarily with roles in estrogen metabolism and signaling. To account for multiple comparisons, statistical significance was defined as p<0.00036. Results Of the 467 enrolled patients with available germline DNA, 152 (33%) discontinued AI therapy because of toxicity. Using a recessive statistical model, an intronic variant in ESR1 (rs9322336) was associated with increased risk of musculoskeletal toxicity-related exemestane discontinuation (HR 5.0 (95% CI 2.1–11.8), p<0.0002). Conclusion An inherited variant potentially affecting estrogen signaling may be associated with exemestane-associated toxicity, which could partially account for intra-patient differences in AI tolerability. Validation of this finding is required. PMID:23546553

  13. Genetic associations with toxicity-related discontinuation of aromatase inhibitor therapy for breast cancer.

    PubMed

    Henry, N Lynn; Skaar, Todd C; Dantzer, Jessica; Li, Lang; Kidwell, Kelley; Gersch, Christina; Nguyen, Anne T; Rae, James M; Desta, Zeruesenay; Oesterreich, Steffi; Philips, Santosh; Carpenter, Janet S; Storniolo, Anna M; Stearns, Vered; Hayes, Daniel F; Flockhart, David A

    2013-04-01

    Up to 25 % of patients discontinue adjuvant aromatase inhibitor (AI) therapy due to intolerable symptoms. Predictors of which patients will be unable to tolerate these medications have not been defined. We hypothesized that inherited variants in candidate genes are associated with treatment discontinuation because of AI-associated toxicity. We prospectively evaluated reasons for treatment discontinuation in women with hormone receptor-positive breast cancer initiating adjuvant AI through a multicenter, prospective, randomized clinical trial of exemestane versus letrozole. Using multiple genetic models, we evaluated potential associations between discontinuation of AI therapy because of toxicity and 138 variants in 24 candidate genes, selected a priori, primarily with roles in estrogen metabolism and signaling. To account for multiple comparisons, statistical significance was defined as p < 0.00036. Of the 467 enrolled patients with available germline DNA, 152 (33 %) discontinued AI therapy because of toxicity. Using a recessive statistical model, an intronic variant in ESR1 (rs9322336) was associated with increased risk of musculoskeletal toxicity-related exemestane discontinuation [HR 5.0 (95 % CI 2.1-11.8), p < 0.0002]. An inherited variant potentially affecting estrogen signaling may be associated with exemestane-associated toxicity, which could partially account for intra-patient differences in AI tolerability. Validation of this finding is required. PMID:23546553

  14. Comparative study on individual aromatase inhibitors on cardiovascular safety profile: a network meta-analysis

    PubMed Central

    Zhao, Xihe; Liu, Lei; Li, Kai; Li, Wusheng; Zhao, Li; Zou, Huawei

    2015-01-01

    The third-generation aromatase inhibitors (AIs: anastrozole, letrozole, and exemestane) have now become standard adjuvant endocrine treatment for postmenopausal estrogen receptor-positive breast cancer complementing chemotherapy and surgery. Because of the absence of direct head-to-head comparisons of these AIs, an indirect comparison is needed for individual treatment choice. In this network systemic assessment, the cardiovascular (CV) side effects in using anastrozole, letrozole, and exemestane based on original studies on AIs vs placebo or tamoxifen were compared. We integrated all available direct and indirect evidences. The odds ratio (OR) of severe CV events for indirect comparisons between exemestane and anastrozole was 1.41 (95% confidence interval [CI] =0.49–2.78), letrozole and anastrozole was 1.80 (95% CI =0.40–3.92), and letrozole and exemestane was 1.46 (95% CI =0.34–3.4). OR of subgroup risk for AIs and tamoxifen were all >1 except for thrombolism risk subgroup. The results showed that the total and severe CV risk ranking is letrozole, exemestane, and anastrozole in descending order. None of the AIs showed advantages in CV events than tamoxifen except for thromboembolism event incidence. PMID:26491345

  15. The farnesoid X receptor is expressed in breast cancer and regulates apoptosis and aromatase expression.

    PubMed

    Swales, Karen E; Korbonits, Márta; Carpenter, Robert; Walsh, Desmond T; Warner, Timothy D; Bishop-Bailey, David

    2006-10-15

    Bile acids are present at high concentrations in breast cysts and in the plasma of postmenopausal women with breast cancer. The farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily that regulates bile acid homeostasis. FXR was detected in normal and tumor breast tissue, with a high level of expression in ductal epithelial cells of normal breast and infiltrating ductal carcinoma cells. FXR was also present in the human breast carcinoma cells, MCF-7 and MDA-MB-468. Activation of FXR by high concentrations of ligands induced MCF-7 and MDA-MB-468 apoptosis. At lower concentrations that had no direct effect on viability, the FXR agonist GW4064 induced expression of mRNA for the FXR target genes, small heterodimer partner (SHP), intestinal bile acid binding protein, and multidrug resistance-associated protein 2 (MRP-2), and repressed the expression of the SHP target gene aromatase. In contrast to MRP-2, mRNA for the breast cancer target genes MDR-3, MRP-1, and solute carrier transporter 7A5 were decreased. Although multidrug resistance transporters were regulated and are known FXR target genes, GW4064 had no effect on the cell death induced by the anticancer drug paclitaxel. Our findings show for the first time that FXR is expressed in breast cancer tissue and has multiple properties that could be used for the treatment of breast cancer.

  16. Aromatase inhibition rapidly affects in a reversible manner distinct features of birdsong

    PubMed Central

    Alward, Beau A.; de Bournonville, Catherine; Chan, Trevor T.; Balthazart, Jacques; Cornil, Charlotte A.; Ball, Gregory F.

    2016-01-01

    Recent evidence has implicated steroid hormones, specifically estrogens, in the rapid modulation of cognitive processes. Songbirds have been a useful model system in the study of complex cognitive processes including birdsong, a naturally learned vocal behavior regulated by a discrete steroid-sensitive telencephalic circuitry. Singing behavior is known to be regulated by long-term actions of estrogens but rapid steroid modulation of this behavior has never been examined. We investigated if acute actions of estrogens regulate birdsong in canaries (Serinus canaria). In the morning, male canaries sing within minutes after light onset. Birds were injected with fadrozole, a potent aromatase inhibitor, or vehicle within 2–5 minutes after lights on to implement a within-subjects experimental design. This single injection of fadrozole reduced the motivation to sing as well as song acoustic stereotypy, a measure of consistency over song renditions, on the same day. By the next day, however, all song measures that were affected had returned to baseline. This study indicates that estrogens also act in a rapid fashion to regulate two distinct features of song, a learned vocal behavior. PMID:27573712

  17. Postmenopausal Breast Cancer, Aromatase Inhibitors, and Bone Health: What the Surgeon Should Know.

    PubMed

    Baatjes, K J; Apffelstaedt, J P; Kotze, M J; Conradie, M

    2016-09-01

    Breast cancer, as the most common malignancy in women, remains a major public health issue despite countless advances across decades. Endocrine therapy is the cornerstone of treatment of the hormone-sensitive subtype of breast cancer. The use of aromatase inhibitors (AIs) in the postmenopausal women has extended the survival beyond that of Tamoxifen, but harbors a subset of side effects, most notably accelerated bone loss. This, however, does not occur in all women undergoing treatment. It is vital to identify susceptible patients early, to limit such events, employ early treatment thereof, or alter drug therapy. International trials on AIs, predominantly performed in North American and European females, provide little information on what to expect in women in developing countries. Here, surgeons often prescribe and manage endocrine therapy. The prescribing surgeon should be aware of the adverse effect of the endocrine therapy and be able to attend to side effects. This review highlights clinical and biochemical factors associated with decrease in bone mineral density in an, as yet, unidentified subgroup of postmenopausal women. In the era of personalized medical care, appropriate management of bone health by surgeons based on these factors becomes increasingly important. PMID:27189076

  18. Masculinization of female golden rabbitfish Siganus guttatus using an aromatase inhibitor treatment during sex differentiation.

    PubMed

    Komatsu, Toru; Nakamura, Shigeo; Nakamura, Masaru

    2006-08-01

    To elucidate the involvement of endogenous estrogen (estradiol-17beta; E2) and the decisive factor (somatic or germinal element) in the ovarian differentiation of tropical marine teleosts, the effect of the aromatase inhibitor (AI) fadrozole on gonadal sex differentiation in the golden rabbitfish Siganus guttatus (Bloch) was examined for different dosages and periods of treatment. Fadrozole interrupted ovarian cavity formation at a dose of 500 microg g(-1) diet, while there was little effect at 10 or 100 microg g(-1). The gonads from both the 30-day and 90-day administration (500 microg g(-1) diet) groups were significantly biased toward testes (P=0.002 and <0.0001, respectively), which suggests strongly that E2 is involved in early ovarian differentiation and that its suppression is an indispensable condition for testicular differentiation in S. guttatus. The results from the two different AI treatment periods imply that the initial feminization of somatic gonadal elements determines subsequent ovarian differentiation, including oogenesis: a conclusion supported by the considerable time lag between ovarian cavity formation and subsequent oogenesis during normal ovarian differentiation in S. guttatus.

  19. Sensitivity of New Zealand mudsnail Potamopyrgus antipodarum (Gray) to a specific aromatase inhibitor.

    PubMed

    Gust, M; Garric, J; Giamberini, L; Mons, R; Abbaci, K; Garnier, F; Buronfosse, T

    2010-03-01

    The freshwater prosobranch Potamopyrgus antipodarum (Molluska, Hydrobiidea, Smith 1889) has been proposed as a suitable species to assess the impact of endocrine disrupting compounds (EDC) in aquatic ecosystems. Steroid hormone biosynthesis pathway is potentially an important target for EDC, and vertebrate-like sex steroids seem to play a functional role in the control of mollusk reproduction. To assess the response and the sensitivity of P. antipodarum to disrupters of the steroid hormone biosynthesis pathway, we have experienced the action of a specific vertebrate aromatase inhibitor, fadrozole, acting on 17beta-estradiol synthesis in two separate 28 and 42d exposures. Fadrozole had effects consistent with the expected mechanism of action. A decrease of the reproduction parameters (such as on the number of neonates and number of embryos in the brood pouch) in a dose-dependant manner was observed. The steroids levels were also impaired with the ratio 17beta-estradiol/testosterone decreased by half in exposed snails. This shift of the steroids balance was accompanied by some alteration in the gonads histology and immunohistochemistry in fadrozole-exposed snails. This study highlights the value role of P. antipodarum as a test species for assessing EDC effects in aquatic wildlife.

  20. Skeletal adverse effects with aromatase inhibitors in early breast cancer: evidence to date and clinical guidance

    PubMed Central

    Servitja, Sonia; Martos, Tamara; Rodriguez Sanz, Maria; Garcia-Giralt, Natalia; Prieto-Alhambra, Daniel; Garrigos, Laia; Nogues, Xavier

    2015-01-01

    Aromatase inhibitors (AIs) are routinely used in the adjuvant treatment of women with hormone receptor-positive early breast cancer. Patients who receive AIs have an increased risk of bone loss and arthralgia compared with those treated with tamoxifen. In addition to the effects of AIs, the population of women with early breast cancer has a high prevalence of 25-hydroxyvitamin D (25(OH)D) insufficiency. In our experience 88% of patients had concentrations lower than 30 ng/ml. Vitamin D supplementation should be adapted to the baseline concentration. Another relevant finding in our research program was the close relationship between 25(OH)D levels and intensity of AI-related arthralgia (AIrA). A target concentration of 40 ng/ml 25(OH)D may prevent development of AIrA. We also demonstrate that AIrA is genetically determined: single nucleotide polymorphisms located in genes encoding key factors for the metabolism of estrogens and vitamin D (CYP17A1, VDR, and CYP27B1) are associated with self-reported arthralgia during AI therapy. We recommend establishing an individualized protocol of bone-health surveillance based on baseline and evolutionary clinical variables. PMID:26327926

  1. The characteristics of aromatase deficient hairless mice indicate important roles of extragonadal estrogen in the skin.

    PubMed

    Tsukahara, Kazue; Kakuo, Shingo; Moriwaki, Shigeru; Hotta, Mitsuyuki; Ohuchi, Atsushi; Kitahara, Takashi; Harada, Nobuhiro

    2008-01-01

    The roles of extragonadal estrogen in the skin are poorly understood, due to the lack of proper animal models. We examined the skin phenotypes of aromatase-knockout hairless (ArKO) mice and wild-type hairless (WT) mice, both of which were obtained through crossbreeding of Ar+/- mice and hairless mice. Differences in the skins of ArKO and WT mice were compared with those of ovariectomized (OVX) and control (Sham) mice. A difference was observed in the skin tone of ArKO mice, which is pale white and differs from the pinkish tone of all other mice. However, both ArKO and OVX mice similarly exhibited deteriorations of skin properties as compared to their respective controls. Furthermore, all the deteriorations were similarly amplified by chronic UVB irradiation in both ArKO and OVX mice as compared to their respective controls. The unique skin phenotype of ArKO mice was observed in sunburn reactions. Specifically, skins of ArKO mice showed no reaction after an acute UVB irradiation at dose intensities caused sunburn in others. However, follow-up observation found delayed reactions associated with brownish skin color and swelling only in ArKO mice, thereby suggesting that the role of extragonadal estrogen may be connected with the protective reactions of skin.

  2. Aromatase inhibition rapidly affects in a reversible manner distinct features of birdsong.

    PubMed

    Alward, Beau A; de Bournonville, Catherine; Chan, Trevor T; Balthazart, Jacques; Cornil, Charlotte A; Ball, Gregory F

    2016-01-01

    Recent evidence has implicated steroid hormones, specifically estrogens, in the rapid modulation of cognitive processes. Songbirds have been a useful model system in the study of complex cognitive processes including birdsong, a naturally learned vocal behavior regulated by a discrete steroid-sensitive telencephalic circuitry. Singing behavior is known to be regulated by long-term actions of estrogens but rapid steroid modulation of this behavior has never been examined. We investigated if acute actions of estrogens regulate birdsong in canaries (Serinus canaria). In the morning, male canaries sing within minutes after light onset. Birds were injected with fadrozole, a potent aromatase inhibitor, or vehicle within 2-5 minutes after lights on to implement a within-subjects experimental design. This single injection of fadrozole reduced the motivation to sing as well as song acoustic stereotypy, a measure of consistency over song renditions, on the same day. By the next day, however, all song measures that were affected had returned to baseline. This study indicates that estrogens also act in a rapid fashion to regulate two distinct features of song, a learned vocal behavior. PMID:27573712

  3. Identification of 42 possible cytochrome C genes in the Shewanella oneidensis genome and characterization of six soluble cytochromes.

    PubMed

    Meyer, Terry E; Tsapin, Alexandre I; Vandenberghe, Isabel; de Smet, Lina; Frishman, Dmitrij; Nealson, Kenneth H; Cusanovich, Michael A; van Beeumen, Jozef J

    2004-01-01

    Through pattern matching of the cytochrome c heme-binding site (CXXCH) against the genome sequence of Shewanella oneidensis MR-1, we identified 42 possible cytochrome c genes (27 of which should be soluble) out of a total of 4758. However, we found only six soluble cytochromes c in extracts of S. oneidensis grown under several different conditions: (1) a small tetraheme cytochrome c, (2) a tetraheme flavocytochrome c-fumarate reductase, (3) a diheme cytochrome c4, (4) a monoheme cytochrome c5, (5) a monoheme cytochrome c', and (6) a diheme bacterial cytochrome c peroxidase. These cytochromes were identified either through N-terminal or complete amino acid sequence determination combined with mass spectroscopy. All six cytochromes were about 10-fold more abundant when cells were grown at low than at high aeration, whereas the flavocytochrome c-fumarate reductase was specifically induced by anaerobic growth on fumarate. When adjusted for the different heme content, the monoheme cytochrome c5 is as abundant as are the small tetraheme cytochrome and the tetraheme fumarate reductase. Published results on regulation of cytochromes from DNA microarrays and 2D-PAGE differ somewhat from our results, emphasizing the importance of multifaceted analyses in proteomics.

  4. Epigenetic Control of Gonadal Aromatase (cyp19a1) in Temperature-Dependent Sex Determination of Red-Eared Slider Turtles

    PubMed Central

    Matsumoto, Yuiko; Buemio, Alvin; Chu, Randy; Vafaee, Mozhgon; Crews, David

    2013-01-01

    In the red-eared slider turtle (Trachemys scripta), a species with temperature-dependent sex determination (TSD), the expression of the aromatase gene during gonad development is strictly limited to the female-producing temperature. The underlying mechanism remains unknown. In this study, we identified the upstream 5′-flanking region of the aromatase gene, gonad-specific promoter, and the temperature-dependent DNA methylation signatures during gonad development in the red-eared slider turtle. The 5′-flanking region of the slider aromatase exhibited sequence similarities to the aromatase genes of the American alligator, chicken, quail, and zebra finch. A putative TATA box was located 31 bp upstream of the gonad-specific transcription start site. DNA methylation at the CpG sites between the putative binding sites of the fork head domain factor (FOX) and vertebrate steroidogenic factor 1 (SF1) and adjacent TATA box in the promoter region were significantly lower in embryonic gonads at the female-producing temperature compared the male-producing temperature. A shift from male- to female-, but not from female- to male-, producing temperature changed the level of DNA methylation in gonads. Taken together these results indicate that the temperature, particularly female-producing temperature, allows demethylation at the specific CpG sites of the promoter region which leads the temperature-specific expression of aromatase during gonad development. PMID:23762231

  5. Effects of atrazine on CYP19 gene expression and aromatase activity in testes and on plasma sex steroid concentrations of male African clawed frogs (Xenopus laevis).

    PubMed

    Hecker, Markus; Park, June-Woo; Murphy, Margaret B; Jones, Paul D; Solomon, Keith R; Van Der Kraak, Glen; Carr, James A; Smith, Ernest E; du Preez, Louis; Kendall, Ronald J; Giesy, John P

    2005-08-01

    Some investigators have suggested that the triazine herbicide atrazine can cause demasculinization of male amphibians via upregulation of the enzyme aromatase. Male adult African clawed frogs (Xenopus laevis) were exposed to three nominal concentrations of atrazine (1, 25, or 250 microg atrazine/l) for 36 days, and testicular aromatase activity and CYP19 gene expression, as well as concentrations of the plasma sex steroids testosterone (T) and 17beta-estradiol (E2), and gonad size (GSI) were measured. There were no effects on any of the parameters measured, with the exception of plasma T concentrations. Plasma T concentrations in X. laevis exposed to the greatest concentration of atrazine were significantly less (p = 0.034) than those in untreated frogs. Both CYP19 gene expression and aromatase activities were low regardless of treatment, and neither parameter correlated with the other. We conclude that aromatase enzyme activity and gene expression were at basal levels in X. laevis from all treatments, and that the tested concentrations of atrazine did not interfere with steroidogenesis through an aromatase-mediated mechanism of action.

  6. Seasonal changes in spermatogenesis and immunolocalization of cytochrome P450 17alpha-hydroxylase/c17-20 lyase and cytochrome P450 aromatase in the wild male ground squirrel (Citellus dauricus Brandt).

    PubMed

    Zhang, Haolin; Sheng, Xia; Hu, Xiao; Li, Xiuwen; Xu, Hui; Zhang, Mengyuan; Li, Ben; Xu, Meiyu; Weng, Qiang; Zhang, Zhixiang; Taya, Kazuyoshi

    2010-06-01

    The purpose of this study was to investigate seasonal changes of spermatogenesis and the cellular localization of P450c17 and P450arom in wild male ground squirrels during the breeding and non-breeding seasons. The testicular weight, testicular size and score count of spermatogenesis from April to September were measured, and histological and immunohistochemical observations of testicular tissues were performed in wild male ground squirrels. In addition, total proteins were extracted from testicular tissue in the breeding and non-breeding seasons and were used for Western blotting analysis for P450c17 and P450arom. There were marked variations in testicular weight, testicular size and score count of spermatogenesis from the breeding season (April) to the non-breeding season (September). Histologically, spermatogonia, primary spermatocytes, secondary spermatocytes and spermatozoa were identified in the breeding season (April). Immunolocalization of P450c17 was detected in Leydig cells and spermatozoa during the breeding season and was only found in Leydig cells during the non-breeding season. The positive signals of P450c17 by Western blotting were both observed in the breeding and non-breeding seasons. Immunolocalization of P450arom was observed in Leydig cells, Sertoli cells and all types of spermatogenic cells including mature-phase spermatozoa in the breeding season, while immunoreactivity for P450arom was not present in the testis of the non-breeding season. With P450arom antibody, a band was also only detected in the breeding season by Western blotting. These results suggest that the seasonal changes in testicular weight and size are correlated with spermatogenesis and immunolocalization of P450c17 and P450arom, and androgen and estrogen may play an important role in the spermatogenesis and testicular recrudescence and regression process.

  7. Cytochrome C: A Biochemistry Laboratory Course

    ERIC Educational Resources Information Center

    Vincent, John B.; Woski, Stephen A.

    2005-01-01

    A laboratory course called cytochrome c that focuses on the theme of biochemical research is presented. The students follow this course by incorporating team-investigation and self-directed experimentation that provides them an opportunity to experience the excitement of research.

  8. Design of ruthenium-cytochrome c derivatives to measure electron transfer to cytochrome c peroxidase.

    PubMed

    Liu, R Q; Geren, L; Anderson, P; Fairris, J L; Peffer, N; McKee, A; Durham, B; Millet, F

    1995-01-01

    A new technique has been introduced to measure interprotein electron transfer which involves photoexcitation of a tris(bipyridine)ruthenium (Ru) complex covalently attached to one of the proteins. Four different strategies have been developed to specifically attach Ru to protein lysine amino groups, histidine imidazole groups, and cysteine sulhydryl groups. These strategies have been used to prepare more than 20 different singly-labeled Ru-cytochrome c derivatives. The new ruthenium photoexcitation technique has been used to study the mechanism for electron transfer between cytochrome c and cytochrome c peroxidase. Laser excitation of a complex between Ru-cytochrome c and cytochrome c peroxidase compound I results in formation of Ru(II*) which is a strong reducing agent, and rapidly transfers an electron to heme c Fe(III) to form Fe(II). The heme c Fe(II) then rapidly transfers an electron to the Trp-191 radical cation in CMPI. The rate constant for this reaction is 6 x 10(4) s-1 for a horse Ru-cytochrome c derivative labeled at lysine 27, and greater than 10(6) s-1 for yeast Ru-cytochrome c derivatives. A second laser flash results in electron transfer from heme c to the oxyferryl heme in cytochrome c peroxidase compound II with a rate constant of 350 s-1. The ruthenium photoreduction technique has been used to study the interaction domain between the two proteins, the pathway for electron transfer to the radical cation and the oxyferryl heme, and the specific residues in the heme crevice which control the electron transfer properties of the Trp-191 radical cation and the oxyferryl heme.

  9. Biogenesis of respiratory cytochromes in bacteria.

    PubMed Central

    Thöny-Meyer, L

    1997-01-01

    Biogenesis of respiratory cytochromes is defined as consisting of the posttranslational processes that are necessary to assemble apoprotein, heme, and sometimes additional cofactors into mature enzyme complexes with electron transfer functions. Different biochemical reactions take place during maturation: (i) targeting of the apoprotein to or through the cytoplasmic membrane to its subcellular destination; (ii) proteolytic processing of precursor forms; (iii) assembly of subunits in the membrane and oligomerization; (iv) translocation and/or modification of heme and covalent or noncovalent binding to the protein moiety; (v) transport, processing, and incorporation of other cofactors; and (vi) folding and stabilization of the protein. These steps are discussed for the maturation of different oxidoreductase complexes, and they are arranged in a linear pathway to best account for experimental findings from studies concerning cytochrome biogenesis. The example of the best-studied case, i.e., maturation of cytochrome c, appears to consist of a pathway that requires at least nine specific genes and more general cellular functions such as protein secretion or the control of the redox state in the periplasm. Covalent attachment of heme appears to be enzyme catalyzed and takes place in the periplasm after translocation of the precursor through the membrane. The genetic characterization and the putative biochemical functions of cytochrome c-specific maturation proteins suggest that they may be organized in a membrane-bound maturase complex. Formation of the multisubunit cytochrome bc, complex and several terminal oxidases of the bo3, bd, aa3, and cbb3 types is discussed in detail, and models for linear maturation pathways are proposed wherever possible. PMID:9293186

  10. Maternal Obesity is Associated with a Lipotoxic Placental Environment

    PubMed Central

    Saben, Jessica; Lindsey, Forrest; Zhong, Ying; Thakali, Keshari; Badger, Thomas M.; Andres, Aline; Gomez-Acevedo, Horacio; Shankar, Kartik

    2014-01-01

    Maternal obesity is associated with placental lipotoxicity, oxidative stress, and inflammation, where MAPK activity may play a central role. Accordingly, we have previously shown that placenta from obese women have increased activation of MAPK-JNK. Here, we performed RNA-sequencing on term placenta from twenty-two subjects who were dichotomized based on pre-pregnancy BMI into lean (BMI 19–24 kg/m2; n = 12) and obese groups (BMI, 32–43 kg/m2; n = 12). RNA-seq revealed 288 genes to be significantly different in placenta from obese women by ≥1.4-fold. GO analysis identified genes related to lipid metabolism, angiogenesis, hormone activity, and cytokine activity to be altered in placenta from obese women. Indicative of a lipotoxic environment, increased placental lipid and CIDEA protein were associated with decreased AMPK and increased activation of NF-κB(p65) in placenta from obese women. Furthermore, we observed a 25% decrease in total antioxidant capacity and increased nuclear FOXO4 localization in placenta from obese women that was significantly associated with JNK activation, suggesting that maternal obesity may also be associated with increased oxidative stress in placenta. Maternal obesity was also associated with decreased HIF-1α protein expression, suggesting a potential link between increased inflammation/oxidative stress and decreased angiogenic factors. Together, these findings indicate that maternal obesity leads to a lipotoxic placental environment that is associated with decreased regulators of angiogenesis and increased markers of inflammation and oxidative stress. PMID:24484739

  11. A novel software-based technique for quantifying placental calcifications and infarctions from ultrasound

    NASA Astrophysics Data System (ADS)

    Ryan, John T.; McAuliffe, Fionnuala; Higgins, Mary; Stanton, Marie; Brennan, Patrick

    2008-03-01

    In obstetrics, antenatal ultrasound assessment of placental morphology comprises an important part of the estimation of fetal health. Ultrasound analysis of the placenta may reveal abnormalities such as placental calcification and infarcts. Current methods of quantification of these abnormalities are subjective and involve a grading system of Grannum stages I-III. The aim of this project is to develop a software tool that quantifies semi-automatically placental ultrasound images and facilitates the assessment of placental morphology. We have developed a 2D ultrasound imaging software tool that allows the obstetrician or sonographer to define the placental region of interest. A secondary reference map is created for use in our quantification algorithm. Using a slider technique the user can easily define an upper threshold based on high intensity for calcification classification and a lower threshold to define infarction regions based on low intensity within the defined region of interest. The percentage of the placental area that is calcified and also the percentage of infarction is calculated and this is the basis of our new metric. Ultrasound images of abnormal and normal placentas have been acquired to aid our software development. A full clinical prospective evaluation is currently being performed and we are currently applying this technology to the three-dimensional ultrasound domain. We have developed a novel software-based technique for calculating the extent of placental calcification and infarction, providing a new metric in this field. Our new metric may provide a more accurate measurement of placental calcification and infarction than current techniques.

  12. Placental Malaria in Colombia: Histopathologic Findings in Plasmodium vivax and P. falciparum Infections

    PubMed Central

    Carmona-Fonseca, Jaime; Arango, Eliana; Maestre, Amanda

    2013-01-01

    Studies on gestational malaria and placental malaria have been scarce in malaria-endemic areas of the Western Hemisphere. To describe the histopathology of placental malaria in Colombia, a longitudinal descriptive study was conducted. In this study, 179 placentas were studied by histologic analysis (112 with gestational malaria and 67 negative for malaria). Placental malaria was confirmed in 22.35%, 50.0% had previous infections, and 47.5% had acute infections. Typical malaria-associated changes were observed in 37%. The most common changes were villitis, intervillitis, deciduitis, increased fibrin deposition, increased syncytial knots, mononuclear (monocytes/macrophages and lymphocytes), polymorphonuclear cell infiltration, and trophozoites in fetal erythrocytes. No association was found between type of placental changes observed and histopathologic classification of placental malaria. The findings are consistent with those reported for placental malaria in other regions. Plasmodium vivax was the main parasite responsible for placental and gestational malaria, but its role in the pathogenesis of placental malaria was not conclusive. PMID:23546807

  13. Modern management of hypervascular placental polypoid mass following spontaneous abortion: a case report and literature review.

    PubMed

    Marques, Kevin; Looney, Christopher; Hayslip, Clifford; Gavrilova-Jordan, Larisa

    2011-08-01

    Hypervascular placental polypoid mass is a possible source of acute hemorrhage after pregnancy. We present a case report and literature review of a rare case after spontaneous miscarriage. We describe the diagnosis, imaging, and management of placental polyps, which includes the use of iliac artery occlusion catheters with concomitant hysteroscopic resection.

  14. Effect of Fetal Size on Fetal Placental Hyaluronan and Hyaluronoglucosaminidases Throughout Gestation in the Pig

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous results indicated that the trophoblast-endometrial epithelial cell bilayer of porcine placenta undergoes microscopic folding during gestation, and the folded bilayer is embedded in placental stroma. We hypothesized that hyaluronan was a component of placental stroma, and that hyaluronidases...

  15. Malignant cancer and invasive placentation: A case for positive pleiotropy between endometrial and malignancy phenotypes.

    PubMed

    D'Souza, Alaric W; Wagner, Günter P

    2014-01-01

    Cancer metastasis is an invasive process that involves the transplantation of cells into new environments. Since human placentation is also invasive, hypotheses about a relationship between invasive placentation in eutherian mammals and metastasis have been proposed. The relationship between metastatic cancer and invasive placentation is usually presented in terms of antagonistic pleiotropy. According to this hypothesis, evolution of invasive placentation also established the mechanisms for cancer metastasis. Here, in contrast, we argue that the secondary evolution of less invasive placentation in some mammalian lineages may have resulted in positive pleiotropic effects on cancer survival by lowering malignancy rates. These positive pleiotropic effects would manifest themselves as resistance to cancer cell invasion. To provide a preliminary test of this proposal, we re-analyze data from Priester and Mantel (Occurrence of tumors in domestic animals. Data from 12 United States and Canadian colleges of veterinary medicine. J Natl Cancer Inst 1971; 47: :1333-44) about malignancy rates in cows, horses, cats and dogs. From our analysis we found that equines and bovines, animals with less invasive placentation, have lower rates of metastatic cancer than felines and canines in skin and glandular epithelial cancers as well as connective tissue sarcomas. We conclude that a link between type of placentation and species-specific malignancy rates is more likely related to derived mechanisms that suppress invasion rather than different degrees of fetal placental aggressiveness. PMID:25324490

  16. [Potentialities of ultrasound study in the evaluation of developing chronic placental insufficiency].

    PubMed

    Nagaĭtseva, E A; Serova, N S

    2013-01-01

    The paper clarifies the ultrasound semiotics of the normal echographic pattern of the placenta in physiological pregnancy. It gives and systematizes the possible variants of the atypical placental structure in placental insufficiency in patients with spontaneous pregnancy and in women undergoing in vitro fertilization.

  17. Selection for placental efficiency in swine: genetic parameters and trends.

    PubMed

    Mesa, H; Safranski, T J; Fischer, K A; Cammack, K M; Lamberson, W R

    2005-05-01

    The objectives of this study were to estimate response to divergent selection for an index of placental efficiency in swine, and to evaluate the effect of placental efficiency on litter size. The selection index (SI) included total born (TB), birth weight (BRWT), and placental weight (PW), and was designed to increase in the high line (H) or decrease in the low line (L) the efficiency of the placental function (PE), defined as the ratio BRWT:PW. (Co)variance components were estimated for direct and maternal additive effects by using an animal model with MTDFREML procedures. Estimated breeding values were calculated by using records on individual BRWT (n = 2,111), PW (n = 2,006), PE (n = 1,677), and SI (n = 1,677). Litter traits were evaluated using records on 193 litters. The model included the fixed effects of contemporary group for all traits, with the addition of sex for individual traits and parity for litter traits. Litter was fitted as an uncorrelated random effect for all traits, and TB was used as a linear and quadratic covariate for BRWT, PW, and PE. Direct heritability estimates from single-trait models were 0.03, 0.25, 0.18, 0.11, and 0.08 for BRWT, PW, PE, SI, and TB, respectively. Estimated breeding values were compared between lines by using a model including generation, line within generation, and replicate within line as the error term. Estimates of genetic divergence were 20.7 +/- 2.7 g, 0.24 +/- 0.03, 0.11 +/- 0.02, and 0.07 +/- 0.02 per generation for PW, PE, SI, and TB, respectively (P < 0.01), but divergence was not significant for BRWT. At Generation 4, direct EBV was higher in L than in H for PW (55.9 +/- 8.7 vs. -24.2 +/- 9.5 g, respectively; P < 0.01) and higher in H than in L for PE (0.58 +/- 0.10 vs. -0.35 +/- 0.09 g, respectively; P < 0.01). However, EBV was not different for BRWT, SI, or TB. These results indicate that PW and PE are susceptible to change by genetic selection; however, the correlated response in TB was an unexpected

  18. Making the impossible possible: rooting the tree of placental mammals.

    PubMed

    Teeling, Emma C; Hedges, S Blair

    2013-09-01

    Untangling the root of the evolutionary tree of placental mammals has been nearly an impossible task. The good news is that only three possibilities are seriously considered. The bad news is that all three possibilities are seriously considered. Paleontologists favor a root anchored by Xenarthra (e.g., sloths and anteater), whereas molecular evolutionists have favored the two other possible roots: Afrotheria (e.g., elephants, hyraxes, and tenrecs) and Atlantogenata (Afrotheria + Xenarthra). Now, two groups of researchers have scrutinized the largest available genomic data sets bearing on the question and have come to opposite conclusions, as reported in this issue of Molecular Biology and Evolution. Needless to say, more research is needed.

  19. Placental DEPTOR as a stress sensor during pregnancy.

    PubMed

    Mparmpakas, Dionisis; Zachariades, Elena; Goumenou, Anastasia; Gidron, Yori; Karteris, Emmanouil

    2012-04-01

    DEPTOR [DEP-domain-containing and mTOR (mammalian target of rapamycin)-interacting protein] is a modulator of mTOR signalling that binds to mTORC (mTOR complex) 1 and mTORC2. However, to date, the precise functions of DEPTOR are not fully elucidated, particularly in reproductive tissues where mTOR acts as a placental nutrient sensor. Pregnancy is associated with major physiological and psychosocial changes and adaptation to these changes is crucial for normal fetal development. In the present study, we tested the hypothesis that maternal stress can affect mTOR signalling at term, and, as a result, influence placental growth. We first investigated the expression of DEPTOR, mTOR, rictor (rapamycin-insensitive companion of mTOR) and raptor (regulatory associated protein of mTOR) from human placentas (n=23) using Q-PCR (quantitative PCR), and correlated these data to days of pregnancy and maternal stress, as well as placental and fetal weight. Maternal and fetal cortisol levels were also measured. JEG-3 and BeWo cells, used as placental in vitro models, were treated with cortisol and DEPTOR expression was assessed using Q-PCR. DEPTOR appears to be the predominant transcript in the human placenta compared with mTOR, rictor and raptor in both term (n=13) and preterm (n=10) placentas as assessed by Q-PCR. There was a significantly lower level only of log-DEPTOR gene expression in the high stress group (-1.34) than in the low stress group (0.07; t₂₀=2.41, P=0.026). Interestingly, mothers with high stress had significantly elevated levels of cortisol (8555 pg/ml) compared with those with low stress (4900 pg/ml). We then tested the hypothesis that cortisol can directly affect DEPTOR expression. When BeWo cells were treated with cortisol 10, 100 and 1000 nM, the expression of DEPTOR was significantly down-regulated by 50, 41 and 39% (all P<0.05) respectively when compared with basal levels. Treatment of JEG-3 cells with cortisol, led to a significant decrease of DEPTOR

  20. Aromatase activity after a short-course of letrozole administration in adult men at sea level and at high altitude (with or without excessive erythrocytosis).

    PubMed

    Gonzales, G F; Tapia, V; Gasco, M; Gonzales-Castañeda, C

    2012-02-01

    Men living at high altitudes in Peru compared to sea level counterparts have erythrocytosis (hemoglobin 16-21 g/dl) or excessive erythrocytosis (hemoglobin>21 g/dl). High testosterone (T) levels in men at high altitude (HA) were associated with excessive erythrocytosis. High androgen levels could be due to a low aromatase activity or to an elevated rate of conversion from precursors to testosterone. The aim of this study was to evaluate aromatase activity and rate of conversion from precursors to testosterone before and after administration of the aromatase enzyme inhibitor letrozole (5 mg/day) for a 5-day period to men at HA and at sea level (SL). The response to short term aromatase inhibition was assessed in 30 adult men living at sea level, 31 native men at HA with erythrocytosis (Hb 16-21 g/dl), and 35 men at HA with excessive erythrocytosis (Hb>21 g/dl). Serum hormone levels, estradiol/testosterone, testosterone/androstenedione, and testosterone/dehydroepiandrosterone sulfate (DHEAS) ratios were measured. Men with erythrocytosis had lower basal serum T/androstenedione ratios than men with excessive erythrocytosis at HA and men at sea level. Men at HA with excessive erythrocytosis had higher T/DHEAS ratios than men with erythrocytosis and than those at sea level before and after letrozole administration. After letrozole administration, both groups of men at high altitude (with erythrocytosis or with excessive erythrocytosis) showed lower aromatase activities than those at sea level. In conclusion, higher serum testosterone levels in men with excessive erythrocytosis were associated with an increased rate of conversion from DHEAS to testosterone rather than to a lower aromatase activity.

  1. Estrogen Receptor 1 Gene Expression and Its Combination with Estrogen Receptor 2 or Aromatase Expression Predicts Survival in Non-Small Cell Lung Cancer

    PubMed Central

    Aresti, Unai; Carrera, Sergio; Iruarrizaga, Eluska; Fuente, Natalia; Marrodan, Ines; de Lobera, Abigail Ruiz; Muñoz, Alberto; Buque, Aitziber; Condori, Elizabeth; Ugalde, Irene; Calvo, Begoña; Vivanco, Guillermo López

    2014-01-01

    The biological roles of estrogen receptor 1 (ERS1), estrogen receptor 2 (ERS2), and aromatase (CYP19A1) genes in the development of non-small cell lung cancer (NSCLC) is unclear, as is the use of their expression as a prognostic factor. The aim of this study was to investigate the prognostic value of estrogen receptors and aromatase mRNA expression, along with aromatase protein concentration, in resected NSCLC patients. Tumor and non-tumor lung tissue samples were analyzed for the mRNA expression of ERS1, ERS2 and CYP19A1 by RT-PCR. Aromatase concentration was measured with an ELISA. A total of 96 patients were included. ERS1 expression was significantly higher in non-tumor tissue than in tumor samples. Two gene expression categories were created for each gene (and protein): high and low. ERS1 high category showed increased overall survival (OS) when compared to the low expression category. Aromatase protein concentration was significantly higher in tumor samples. Higher ERS1 expression in tumor tissues was related to longer overall survival. The analysis of gene expression combinations provides evidence for longer OS when both ERS1 and ERS2 are highly expressed. ESR1, alone or in combination with ERS2 or CYP19A1, is the most determining prognostic factor within the analyzed 3 genes. It seems that ERS1 can play a role in NSCLC prognosis, alone or in combination with other genes such as ERS2 or Cyp19a1. ERS2 in combination with aromatase concentration could have a similar function. PMID:25310221

  2. Reduced estradiol synthesis by letrozole, an aromatase inhibitor, is protective against development of pentylenetetrazole-induced kindling in mice.

    PubMed

    Rashid, Davood; Panda, B P; Vohora, Divya

    2015-11-01

    Neurosteroids, such as testosterone and their metabolites, are known to modulate neuronal excitability. The enzymes regulating the metabolism of these neurosteroids, thus, may be targeted as a noval strategy for the development of new antiepileptic drugs. The present work targeted two such enzymes i,e aromatase and 5α-reductase in order to explore the potential of letrozole (an aromatase inhibitor) on pentylenetetrazole (PTZ)-induced kindling in mice and the ability of finasteride (a 5α-reductase inhibitor) to modulate any such effects. PTZ (30 mg/kg, i.p.), when administered once every two days (for a total of 24 doses) induced kindling in Swiss albino mice. Letrozole (1 mg/kg, p.o.), administered prior to PTZ, significantly reduced the % incidence of kindling, delayed mean onset time of seizures and reduced seizure severity score. Letrozole reduced the levels of plasma 17β-estradiol after induction of kindling. The concurrent administration of finasteride and letrozole produced effects similar to letrozole on PTZ-kindling and on estradiol levels. This implies that the ability of letrozole to redirect the synthesis of dihydrotestosterone (DHT) and 5α-androstanediol from testosterone doesn't appear to play a significant role in the protective effects of letrozole against PTZ kindling. Letrozole, however, increased the levels of 5α-DHT in mice plasma. The aromatase inhibitors, thus, may be exploited for inhibiting the synthesis of proconvulsant (17β-estradiol) and/or redirecting the synthesis of anticonvulsant (DHT and 5α-androstanediol) neurosteroids.

  3. Effects of bisphenol A and triclocarban on brain-specific expression of aromatase in early zebrafish embryos

    PubMed Central

    Chung, Eunah; Genco, Maria C.; Megrelis, Laura; Ruderman, Joan V.

    2011-01-01

    Estrogen regulates numerous developmental and physiological processes. Most effects are mediated by estrogen receptors (ERs), which function as ligand-regulated transcription factors. Estrogen also regulates the activity of GPR30, a membrane-associated G protein-coupled receptor. Many different types of environmental contaminants can activate ERs; some can bind GPR30 as well. There is growing concern that exposure to some of these compounds, termed xenoestrogens, is interfering with the behavior and reproductive potential of numerous wildlife species, as well as affecting human health. Here, we investigated how two common, environmentally pervasive chemicals affect the in vivo expression of a known estrogen target gene in the brain of developing zebrafish embryos, aromatase AroB, which converts androgens to estrogens. We confirm that, like estrogen, the well-studied xenoestrogen bisphenol A (BPA, a plastics monomer), induces strong brain-specific overexpression of aromatase. Experiments using ER- and GPR30-selective modulators argue that this induction is largely through nuclear ERs. BPA induces dramatic overexpression of AroB RNA in the same subregions of the developing brain as estrogen. The antibacterial triclocarban (TCC) by itself stimulates AroB expression only slightly, but TCC strongly enhances the overexpression of AroB that is induced by exogenous estrogen. Thus, both BPA and TCC have the potential to elevate levels of aromatase and, thereby, levels of endogenous estrogens in the developing brain. In contrast to estrogen, BPA-induced AroB overexpression was suppressed by TCC. These results indicate that exposures to combinations of certain hormonally active pollutants can have outcomes that are not easily predicted from their individual effects. PMID:22006313

  4. Arsenic-induced cancer cell phenotype in human breast epithelia is estrogen receptor-independent but involves aromatase activation

    PubMed Central

    Xu, Yuanyuan; Tokar, Erik J.; Waalkes, Michael P.

    2013-01-01

    Accumulating data suggest arsenic may be an endocrine disruptor, and tentatively linked to breast cancer by some studies. Therefore, we tested the effects of chronic inorganic arsenic exposure on the normal, estrogen receptor (ER)-negative breast epithelial cell line, MCF-10A. Cells were chronically exposed to a low-level arsenite (500 nM) for up to 24 weeks. Markers of cancer cell phenotype and expression of critical genes relevant to breast cancer or stem cells (SCs) were examined. After 24 weeks, chronic arsenic-exposed breast epithelial (CABE) cells showed increases in secreted MMP activity, colony formation, invasion and proliferation rate, indicating an acquired cancer cell phenotype. These CABE cells presented with basal-like breast cancer characteristics, including ER-α, HER-2 and progesterone receptor negativity, and overexpression of K5 and p63. Putative CD44+/CD24−/low breast SCs were increased to 80% over control in CABE cells. CABE cells also formed multilayer cell mounds, indicative of loss of contact inhibition. These mounds showed high levels of K5 and p63 indicating the potential presence of CSCs. Epithelial-to-mesenchymal transition occurred during arsenic exposure.. Overexpression of aromatase, a key rate-limiting enzyme in estrogen synthesis, occurred with arsenic starting early on in exposure. Levels of 17β-estradiol increased in CABE cells and their conditioned medium. The aromatase inhibitor, letrozole abolished arsenic-induced increases of 17β-estradiol production, and reversed cancer cell phenotype. Thus, chronic arsenic exposure drive human breast epithelia into a cancer cell phenotype with an apparent overabundance of putative CSCs. Arsenic appears to transform breast epithelia through overexpression of aromatase, thereby activating oncogenic processes independent of ER. PMID:24068038

  5. Contribution of Estrone Sulfate to Cell Proliferation in Aromatase Inhibitor (AI) -Resistant, Hormone Receptor-Positive Breast Cancer

    PubMed Central

    Hanamura, Toru; Gohno, Tatsuyuki; Niwa, Toshifumi; Yamaguchi, Yuri; Horiguchi, Jun; Hayashi, Shin-ichi

    2016-01-01

    Aromatase inhibitors (AIs) effectively treat hormone receptor-positive postmenopausal breast cancer, but some patients do not respond to treatment or experience recurrence. Mechanisms of AI resistance include ligand-independent activation of the estrogen receptor (ER) and signaling via other growth factor receptors; however, these do not account for all forms of resistance. Here we present an alternative mechanism of AI resistance. We ectopically expressed aromatase in MCF-7 cells expressing green fluorescent protein as an index of ER activity. Aromatase-overexpressing MCF-7 cells were cultured in estrogen-depleted medium supplemented with testosterone and the AI, letrozole, to establish letrozole-resistant (LR) cell lines. Compared with parental cells, LR cells had higher mRNA levels of steroid sulfatase (STS), which converts estrone sulfate (E1S) to estrone, and the organic anion transporter peptides (OATPs), which mediate the uptake of E1S into cells. LR cells proliferated more in E1S-supplemented medium than did parental cells, and LR proliferation was effectively inhibited by an STS inhibitor in combination with letrozole and by ER-targeting drugs. Analysis of ER-positive primary breast cancer tissues showed a significant correlation between the increases in the mRNA levels of STS and the OATPs in the LR cell lines, which supports the validity of this AI-resistant model. This is the first study to demonstrate the contribution of STS and OATPs in E1S metabolism to the proliferation of AI-resistant breast cancer cells. We suggest that E1S metabolism represents a new target in AI-resistant breast cancer treatment. PMID:27228187

  6. Maternal omega-3 fatty acid intake increases placental labyrinthine antioxidant capacity but does not protect against fetal growth restriction induced by placental ischaemia-reperfusion injury.

    PubMed

    Jones, Megan L; Mark, Peter J; Waddell, Brendan J

    2013-12-01

    Placental oxidative stress plays a key role in the pathophysiology of several placenta-related disorders. Oxidative stress occurs when excess reactive oxygen species (ROS) damages cellular components, an outcome limited by antioxidant enzymes; mitochondrial uncoupling protein 2 (UCP2) also limits ROS production. We recently reported that maternal dietary omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation reduced placental oxidative damage and enhanced fetal and placental growth in the rats. Here, we examined the effect of n-3 PUFAs on placental antioxidant defences and whether n-3 PUFA supplementation could prevent growth restriction induced by placental ischaemia-reperfusion (IR), a known inducer of oxidative stress. Rats were fed either standard or high-n-3 PUFA diets from day 1 of pregnancy. Placentas were collected on days 17 and 22 in untreated pregnancies (term=day 23) and at day 22 following IR treatment on day 17. Expression of several antioxidant enzyme genes (Sod1, Sod2, Sod3, Cat, Txn1 and Gpx3) and Ucp2 was measured by quantitative RT-PCR in the placental labyrinth zone (LZ) and junctional zone (JZ). Cytosolic superoxide dismutase (SOD), mitochondrial SOD and catalase (CAT) activities were also analyzed. Maternal n-3 PUFA supplementation increased LZ mRNA expression of Cat at both gestational days (2- and 1.5-fold respectively; P<0.01) and female Sod2 at day 22 (1.4-fold, P<0.01). Cytosolic SOD activity increased with n-3 PUFA supplementation at day 22 (1.3-fold, P<0.05). Sod1 and Txn1 expression decreased marginally (30 and 22%, P<0.05). JZ antioxidant defences were largely unaffected by diet. Despite increased LZ antioxidant defences, maternal n-3 PUFA supplementation did not protect against placental IR-induced growth restriction of the fetus and placental LZ.

  7. Interaction with membranes of cytochrome c554 from Nitrosomonas europaea.

    PubMed

    McTavish, H; Arciero, D M; Hooper, A B

    1995-12-01

    Two c-cytochromes extrinsically bound to the membranes of Nitrosomonas europaea have been identified. One is the tetraheme cytochrome c554, a protein previously described as soluble and periplasmic. Depending on the concentration of Fe and Cu in the growth medium, from 50 to 100% of the total cellular cytochrome c554 is membrane-associated. The cytochromes c554 found in the soluble or membrane fractions are identical in the spectroscopic, chromatographic, or primary structural properties examined. The interaction of cytochrome c554 with membranes is ionic in nature; it is disrupted by high concentrations of salt. Both membrane-derived and periplasmic forms of cytochrome c554 rebind tightly to membranes which have been washed free of the cytochrome. Cytochrome c554 binds to phospholipid vesicles, suggesting that phospholipids may play a role in the interaction of this cytochrome with the membrane. During the oxidation of NH2OH, the ability of the soluble hydroxylamine oxidoreductase (HAO) to transfer electrons to its natural electron acceptor, cytochrome c554, is substantially impaired when the latter is bound to phospholipid vesicles. The second c-cytochrome associated with membranes in N. europaea is identified as HAO based on its catalytic activity and the presence of a 464-nm ferrous absorption band. A small fraction of HAO is found to be membrane-bound and only in cells grown under low Fe/low Cu. This subpopulation of HAO can be released from the membranes without detergents. PMID:7503559

  8. Aromatase deficiency in male and female siblings caused by a novel mutation and the physiological role of estrogens

    SciTech Connect

    Morishima, Akira; Grumbach, M.M.; Simpson, E.R. |

    1995-12-01

    The aromatase enzyme complex catalyzes the conversion of androgens to estrogens in a wide variety of tissues, including the ovary, testis, placenta, brain, and adipose tissue. Only a single human gene encoding aromatase P450 (CYP19) has been isolated; tissue-specific regulation is controlled in part by alternative promoters in a tissue-specific manner. We