Estrone Sulfate Research Articles

Characterizing the steroidal milieu in amniotic fluid of mid-gestation: A LC–MS/MS study

Growth and development of an embryo or fetus during human pregnancy mainly depend on intact hormone biosynthesis and metabolism in maternal amniotic fluid (AF). We investigated the hormonal milieu in AF and developed a liquid chromatography-tandem mass spectrometry (LC–MS/MS) method for the determination of 14 sulfated and 6 unconjugated steroids in AF. 65 A F samples (male: female = 35: 30) of mid-gestation ranging from 16th week of gestation to 25th week of gestation were analyzed. Reference data of 20 steroid levels in AF of healthy women were provided. 13 sulfated and 3 unconjugated steroids were for the first time quantified in AF by LC–MS/MS. Highest concentrations were found for pregnenolone sulfate (PregS: mean ± SD, 8.6 ± 3.7 ng/mL), 17α-hydroxypregnenolone sulfate (17OHPregS: 4.9 ± 2.0 ng/mL), epitestosterone sulfate (eTS: 7.3 ± 3.6 ng/mL), 16α-hydroxydehydroepiandrosterone sulfate (16OH-DHEAS: 21.5 ± 10.7 ng/mL), androsterone sulfate (AnS: 9.2 ± 7.4 ng/mL), estrone sulfate (E1S: 3.0 ± 3.0 ng/mL), estriol 3-sulfate (E3S: 8.1 ± 4.0 ng/mL) and estriol (E3: 1.2 ± 0.4 ng/mL). Only testosterone (T) showed a significant sex difference (p < 0.0001). Correlations between AF steroids mirrored the steroid metabolism of the feto-placental unit, and not only confirmed the classical steroid pathway, but also pointed to a sulfated steroid pathway.

Abstract 2206: A new sensitive, accurate liquid chromatography-tandem mass spectrometry (LC-MS-MS) method to measure circulating estrogens, androgens, and progesterone in postmenopausal and premenopausal women

Abstract Endogenous steroid hormones play a critical role in the etiology of breast cancer. However, the interrelationships among estrogens, androgens, and progesterone in determining risk are not well understood. Relative strengths of associations, independent and joint effects, differential effects for tumor subtypes, and effect modification by lifestyle and genetic profile remain unclear. A major reason is the limited accuracy, specificity, and sensitivity of many steroid hormone assays, especially at the low circulating hormone concentrations characteristic of postmenopausal women. CDC developed a new sensitive, accurate isotope dilution LC-MS/MS method capable of measuring eight important steroid hormones in 200 µL of female serum. The method uses sequential liquid-liquid extractions for isolation of estradiol (E2), estrone (E1), estrone sulfate (E1S), testosterone (TT), androstenedione (A), dehydroepiandrosterone sulfate (DHEAS), progesterone (P), and 17-hydroxyprogesterone (17-OHP) without derivatization or hydrolysis. Chromatographic separation of the steroids is carried out using a phenyl-hexyl HPLC column and a gradient of methanol and methanol:water. Scheduled selected reaction monitoring by electrospray ionization in the positive and negative ion modes is applied to quantify the analytes. Two mass transitions, each specific to the fragmentation of the analyte, are monitored for each analyte: quantitation ion (QI) and confirmation ion (CI). The QI to CI ratios are used as criteria to identify possible interferences. The method is able to measure each steroid in nearly all postmenopausal women as well as premenopausal women. Limits of detection in serum-based materials are: E2 1.72 pg/mL, E1 0.13 ng/dL, E1S 2.04 pg/mL, TT 0.57 ng/dL, A 0.82 ng/dL, DHEAS 0.22 µg/dL, P 0.86 ng/dL, and 17-OHP 0.41 ng/dL. Precision, expressed as coefficients of variation and evaluated at three levels for each analyte, ranged from 1.2 to 9.9%. Average bias, a measure of accuracy, ranged from -0.3 to 8.8%. The method is certified through the CDC Hormone Standardization Program for estradiol and testosterone and meets the requirements of the College of American Pathologists Proficiency Testing Program for androgens and progesterone. This new, highly specific and sensitive method demonstrates high accuracy and precision while requiring small amounts of specimens. It can assay up to 140 samples at once. Thus, the method is suitable for large epidemiologic studies investigating the hormonal etiology of breast, endometrial, and ovarian cancer. Citation Format: Lumi Duke, Paul H. Kim, Julianne Cook Botelho, Regina G. Ziegler, Hubert Vesper. A new sensitive, accurate liquid chromatography-tandem mass spectrometry (LC-MS-MS) method to measure circulating estrogens, androgens, and progesterone in postmenopausal and premenopausal women [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2206.

Abstract 1161: Interaction between doxorubicin and amniotic membrane stem cells on the canine inflammatory mammary cancer cell line IPC-366

Abstract The aim of this study was to evaluate the efficiency of doxorubicin, canine amniotic membrane stem cells (AMC) and the association between them in the triple-negative canine inflammatory mammary cancer cell line IPC-366. Experiments were carried out for 72 hours in 4 groups: IPC-366 untreated cells; cells treated with 10mg/mL of doxorubicin; coculture IPC-366 cells with 105 AMC; and cells treated with doxorubicin+AMC. MTT assays were performed for evaluating proliferation; flow cytometry to analyze hormonal and angiogenesis markers, and anti-inflammatory cytokines; and EIA techniques were used to evaluate secretion of steroid hormones (progesterone (P4); dehydroepiandrosterone (DHEA); androtenedione (A4); 17β-estradiol (E2); estrone sulphate (SO4E1)) in cell culture media. Results showed that cells treated with 10 mg/mL of doxorubicin resulted in a reduction of 71.64% on cell proliferation at 72h of treatment. A reduction in the expression of VEGF and PCNA-3 was observed by flow cyotmetry in treated cells compared to control cells. Differences on IL-10 were found within groups: treatment with doxorubicin resulted in a reduction on IL-10 expression although in AMC group expression remained similar to control group. Estrogen intracellular levels were significantly increased in doxorubicin+AMC group (4.67% vs. 27.1%). Regarding steroid hormone secretion, in AMC treated group any differences in hormone levels were found compared to control group. P4 and E2 secretion resulted in an increase in doxorubicin-treated group although in doxorubicin+AMC group these levels decreased with respect to control group. DHEA secretion was significantly decreased in treated groups compared to control group. Interestingly, A4 and SO4E1 secretion levels showed a significant increase compared to control group. Collectively, these results suggest that combination of doxorubicin and AMC caused a synergy that alters the cancer cell's secretion hormone profile by accumulation of estrogens. These findings attempt to give an approach of the combination of well-known treatments and amniotic stem cells as a canine mammary tumors therapy. Citation Format: Jessica Borghesi, Sara Caceres, Lara C. Mario, Rafael Gonçalves Hayashi, Laura Peña, Angela Alonso-Diez, Maria J. Illera, Gema Silvan, Maria A. Miglino, Ana C. Oliveira Carreira, Phelipe Oliveira Favaron, Juan C. Illera. Interaction between doxorubicin and amniotic membrane stem cells on the canine inflammatory mammary cancer cell line IPC-366 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1161.

The scaffold protein PDZK1 modulates expression and function of the organic anion transporting polypeptide 2B1

The protein family of Organic Anion Transporting Polypeptides (OATPs) summarizes various transporters known to facilitate cellular uptake of xenobiotics. One member of this family is OATP2B1. This transporter is ubiquitously expressed and possesses a PDZ-binding motif at the C-terminus. PDZK1 (PDZ domain-containing 1) is a scaffold protein that influences function of different membrane proteins by sorting/stabilization of their membrane localization. It was aim of the herein reported study to investigate whether there is an interaction between OATP2B1 and PDZK1, and to further characterize its impact on transport function. At first expression of both OATP2B1 and PDZK1 was evaluated in liver, kidney and intestine. Based on the existence of a C-terminal PDZ-class I binding motif in OATP2B1 and the co-expression in all tested tissues an interaction was likely. Testing the influence of PDZK1 on OATP2B1 transport function revealed enhanced transport capacity for estrone 3-sulfate, thereby suggesting a change in OATP2B1 amount in the membrane. This assumption was validated by Western blot analysis. Finally, deletion of the C-terminal PDZ-binding motif in OATP2B1 lowered the impact of PDZK1 on transport function. Taken together, we report an interaction of PDZK1 with OATP2B1, which influences localization and function of the transporter. Changes in PDZK1 expression may therefore be one factor contributing to interindividual differences in OATP2B1 mediated pharmacokinetic processes.

Sequential concentrations of placental growth factor and haptoglobin, and their relation to oestrone sulphate and progesterone in pregnant Spanish Purebred mare

The objectives of this study were to establish reference values for serum concentrations of placental growth factor (PlGF) and haptoglobin (Hp), and to analyze whether the levels of oestrone sulphate (E1S) and progesterone (P4) are physiologically involved in the dynamic modifications of the above parameters in pregnant mares. A total of 30 healthy Spanish Purebred mares ranging in age 9.33 ± 3.31 years were studied during the 11 months of gestation. Serum concentrations of PlGF were detected by EIA, Hp using commercial Phase Haptoglobin assay and E1S and P4 levels through RIA. The serum concentrations of PlGF ranged between 31.70 and 223.60 ng/mL, with a mean value of 57.64 ± 18.05 ng/mL. Serum PlGF levels increased significantly during the 1st and 2nd months, reaching the maximum value in the 3rd month and the minimum value in the 10th month. Hp concentrations increased progressively and significantly from the 5th until the 10th month of gestation (P < 0.05), decreasing in the 11th month of pregnancy. E1S increased significantly from the 3rd until the 7th month, decreasing progressively towards the end of gestation. P4 increased significantly in the 3rd and 4th month and decreased significantly in the 6th and 7th (P < 0.05), with variable oscillations during last months of pregnancy. PlGF and Hp were significantly and negatively correlated (r = -0.27; P < 0.05). In the healthy mare, PlGF and Hp act asynchronously and independent of steroid E1S and P4.

Single Amino Acid Mutations in the Na+/Taurocholate Cotransporting Polypeptide (NTCP) Result in Substrate‐Dependent Effects

Nonsynonymous polymorphisms can significantly impact the function of a protein. However, so far, the outcome of such mutations at non‐conserved positions are difficult to predict. Previous work showed that some non‐conserved positions have an unexpected outcome when they are mutated: if multiple amino acids are substituted, the results show progressive alterations like a “rheostat”, rather than an “all‐or‐nothing” effect often seen for mutations at conserved positions (“toggle”). To begin to define rules for predicting mutation outcomes at rheostat positions, we used the Na+/Taurocholate Cotransporting Polypeptide (NTCP) as a model transmembrane transporter. NTCP is a sodium dependent bile acid transporter expressed at the basolateral membrane of human hepatocytes. NTCP is important for the enterohepatic circulation of bile acids and also mediates the transport of steroid hormones like estrone‐3‐sulfate (E3S) or drugs like rosuvastatin. We initially focused on the S267F polymorphism that decreased taurocholate transport, stimulated rosuvastatin uptake, and showed no effect on E3S transport. We replaced the serine with all other nineteen amino acids by site directed mutagenesis, transfected the cDNAs into human embryonic kidney cells (HEK293), and determined the uptake of tritiated substrates. In addition, we identified the conserved G102 and the non‐conserved Y146 positions using multiple sequences alignments and homology modeling based on the structures of two bacterial homologues. Both positions fall in mobile regions of NTCP. Interestingly, mutations at S267 resulted in a clear rheostat behavior for taurocholate uptake, with S267F showing only 15% of the function of wild‐type NTCP. Similarly, rheostat behavior was observed for E3S and rosuvastatin, but several mutants transported these substrates 2‐ to 10‐fold higher than wild‐type NTCP, demonstrating that the different amino acid replacements resulted in substrate‐dependent effects. As expected, the non‐conserved Y146 demonstrated rheostat behavior for all three substrates. However, the conserved G102 turned out to be a rheostat position for taurocholate transport but a toggle for the uptake of E3S and rosuvastatin. In summary, we have determined that rheostat positions exist in human NTCP. Furthermore, the functional consequences of single amino acid mutations at the three positions studied so far, varied depending on the substrate tested. Therefore, functional predictions of amino acid mutations seem to be more challenging and will require further experiments at additional positions to potentially define a unifying set of rules.Support or Funding InformationNIH R01 GM077336, P30 GM118247, W.M. Keck FoundationThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Concentration range of serum sex steroids in normal postmenopausal women and those with diagnosis of vulvovaginal atrophy.

The aim of the study was to determine the range of serum sex-related steroids in normal postmenopausal women and in women of the same age with a diagnosis of vulvovaginal atrophy (VVA). Validated mass spectrometry-based assays coupled to gas or liquid chromatography were used over a 10-year period for steroid measurements. Serum samples were obtained in up to 1,512 women aged 55 to 65 years. Serum estrone sulfate (E1S) and androsterone glucuronide (ADT-G), the main metabolites of estrogens and androgens, respectively, were 16.9% (P = 0.005) and 16.1% (P = 0.001) higher in women not diagnosed with moderate/severe VVA than those diagnosed with VVA. Serum estrone (E1) was 14.5% (P < 0.0001) higher in women with no diagnosis of VVA, whereas the other steroids did not show meaningful differences. The limited biological significance of serum estradiol (E2) and testosterone is supported by the lack of statistical significance in the serum concentrations of these two steroids between the two groups. Most importantly, for the women without a diagnosis of VVA, the normal upper limit (95 centile) of serum E2 was 9.15 pg/mL (n = 364) and 10.7 pg/mL (n = 67) for a weighted average of 9.99 pg E2/mL. A limit of 10 pg E2/mL has recently been found by two other laboratories. When comparing 50- to 59-year-old and 70- to 79-year-old women, serum E2, E1S, ADT-G, and DHEA were, respectively, 24.4%, 22.6%, 27.0%, and 85.9% higher in the younger group. Somewhat higher values, namely, 16.9% and 16.1%, are observed in the serum concentrations of the estrogen (E1S) and androgen (ADT-G) metabolites in normal compared with women with a diagnosis of VVA. Such data indicating a lower estrogenic and androgenic global exposure in women diagnosed with VVA offers an opportunity for the local intravaginal administration of DHEA to replace the deficiency in endogenous DHEA.

Organic solute transporter OSTα/β is overexpressed in nonalcoholic steatohepatitis and modulated by drugs associated with liver injury.

The heteromeric steroid transporter organic solute transporter α/β (OSTα/β, SLC51A/B) was discovered over a decade ago, but its physiological significance in the liver remains uncertain. A major challenge has been the lack of suitable models expressing OSTα/β. Based on observations first reported here that hepatic OSTα/β is upregulated in nonalcoholic steatohepatitis, the aim of this research was to develop an in vitro model to evaluate OSTα/β function and interaction with drugs and bile acids. OSTα/β expression in human liver tissue was analyzed by quantitative RT-PCR, Western blotting, and immunofluorescence. Radiolabeled compounds were used to determine OSTα/β-mediated transport in the established in vitro model. The effect of bile acids and drugs, including those associated with cholestatic drug-induced liver injury, on OSTα/β-mediated transport was evaluated. Expression of OSTα/β was elevated in the liver of patients with nonalcoholic steatohepatitis and primary biliary cholangitis, whereas hepatocyte expression of OSTα/β was low in control liver tissue. Studies in the novel cell-based system showed rapid and linear OSTα/β-mediated transport for all tested compounds: dehydroepiandrosterone sulfate, digoxin, estrone sulfate, and taurocholate. The interaction study with 26 compounds revealed novel OSTα/β inhibitors: a biomarker for cholestasis, glycochenodeoxycholic acid; the major metabolite of troglitazone, troglitazone sulfate; and a macrocyclic antibiotic, fidaxomicin. Additionally, some drugs (e.g., digoxin) consistently stimulated taurocholate uptake in OSTα/β-overexpressing cells. Our findings demonstrate that OSTα/β is an important transporter in liver disease and imply a role for this transporter in bile acid-bile acid and drug-bile acid interactions, as well as cholestatic drug-induced liver injury. NEW & NOTEWORTHY The organic solute transporter OSTα/β is highly expressed in hepatocytes of liver tissue obtained from patients with nonalcoholic steatohepatitis and primary biliary cholangitis. OSTα/β substrates exhibit rapid, linear, and concentration-driven transport in an OSTα/β-overexpressing cell line. Drugs associated with hepatotoxicity modulate OSTα/β-mediated taurocholate transport. These data suggest that hepatic OSTα/β plays an essential role in patients with cholestasis and may have important clinical implications for bile acid and drug disposition.

AG490, a JAK2-specific inhibitor, downregulates the expression and activity of organic anion transporter-3

Human organic anion transporter-3 (hOAT3) is richly expressed in the kidney, where it plays critical roles in the secretion of clinically important drugs, including anti-viral therapeutics, anti-cancer drugs, antibiotics, antihypertensives, and anti-inflammatories. In the current study, we examined the role of AG490, a specific inhibitor of the Janus tyrosine kinase 2 (JAK2), in hOAT3 transport activity in the kidney COS-7 cells. AG490 induced a time- and concentration-dependent inhibition of hOAT3-mediated uptake of estrone sulfate, a prototypical substrate for the transporter. The inhibitory effect of AG490 correlated with a reduced expression of hOAT3 at the cell surface. Our lab previously demonstrated that Nedd4-2, a ubiquitin ligase, down regulates OAT expression and transport activity by enhancing OAT ubiquitination, which leads to an internalization of OAT from cell surface to intracellular compartments and subsequent degradation. In the current study, we showed that treatment of hOAT3-expressing cells with AG490 resulted in an enhanced hOAT3 ubiquitination and degradation, which was accompanied by a strengthened association of Nedd4-2 with hOAT3 and a reduction in Nedd4-2 phosphorylation. SiRNA knockdown of endogenous Nedd4-2 abrogated the effects of AG490 on hOAT3. In summary, our study demonstrated that AG490 regulates hOAT3 expression and transport activity through the modulation of Nedd4-2.

The activity of organic anion transporter-3: Role of dexamethasone

Human organic anion transporter-3 (hOAT3) is richly expressed in the kidney, where it plays critical roles in the secretion, from the blood to urine, of clinically important drugs, such as anti-viral therapeutics, anti-cancer drugs, antibiotics, antihypertensives, and anti-inflammatories. In the current study, we examined the role of dexamethasone in hOAT3 transport activity in the kidney HEK293 cells. Cis-inhibition study showed that dexamethasone exhibited a concentration-dependent inhibition of hOAT3-mediated uptake of estrone sulfate, a prototypical substrate for the transporter, with IC50 value of 49.91 μM. Dixon plot analysis revealed that inhibition by dexamethasone was competitive with a Ki = 47.08 μM. In contrast to the cis-inhibition effect of dexamethasone, prolonged incubation (6 h) of hOAT3-expressing cells with dexamethasone resulted in an upregulation of hOAT3 expression and transport activity, kinetically revealed as an increase in the maximum transport velocity Vmax without meaningful alteration in substrate-binding affinity Km. Such upregulation was abrogated by GSK650394, a specific inhibitor for serum- and glucocorticoid-inducible kinases (sgk). Dexamethasone also enhanced sgk1 phosphorylation. Our study demonstrated that dexamethasone exhibits dual effects on hOAT3: it is a competitive inhibitor for hOAT3-mediated transport, and interestingly, when entering the cells, it stimulates hOAT3 expression and transport activity through sgk1.

Serum progesterone and oestrone sulphate concetrations for monitoring fertility in Sows

Blood samples were taken from 161 sows the days 19-21 (serum progesterone assessments), from 306 sows on days 24-30 (serum oestrone sulphate assessments) and from 150 sows on day 20 (serum progesterone assessments) and on days 26-29 (serum oestrone sulphate assessments) after service. Actual farrowing or abortion and signs of return to oestrus were used as criteria for pregnancy and non-pregnancy, respectively. Litter size was also recorded at each farrowing. The results showed that the overall accuracy of progesterone and oestrone sulphate for predicting pregnant sows was 90.7% and 97.2%, respectively. The highest accuracy of oestrone sulphate (100%) was noticed on days 27 and 28 after service. The overrall accuracy of the combination of both progesterone and oestrone sulphate assessments to detect pregnant sows was 97% and to detect non-pregnant sows was 100%. Significant correlation coefficients between serum oestrone sulphate concentration and litter size were found on days 24,26,27, 28,29 and 30, but the highest correlation coefficient was noticed on day 28 after service (r=0.51, Ρ, 0.001). Moreover, it was also found that mean litter size was significantly higher (P &lt;0.05). in sows with serum oestrone sulphate concentrations &gt; 1 ng/ml compared with concentrations &lt; 1 ng/ml from day 26 up to day 30 after service. It is concluded that serum progesterone assessment helps in the determination of the non-pregnant sows early enough for problems related to failure of fertilization to be promptly dealt with. Serum oestrone sulphate concentration on day 28 after service can be used as an indicator of conception, as a predictor of small litter size and also can help in the estimation of embryonic mortality. The combination of these two assessments, in addition to their value in pregnancy diagnosis, can be useful in identifying concurrent reproductive problems in units with sub-optimal productivity.

ATP-Binding Cassette Transporter A Subfamily 8 Is a Sinusoidal Efflux Transporter for Cholesterol and Taurocholate in Mouse and Human Liver.

The ATP-binding cassette (ABC) transporter A subfamily 8 (ABCA8) belongs to the ABCA6-like transporters subgroup, which is distinct from the ABCA1-like subgroup in the ABCA family. The expression and function of the short-size human ABCA8 lacking one of the two ATP-binding domains for ATP hydrolysis, which are regularly present in the other ABCA transporters, have been reported. However, the functional differences between the short-size human ABCA8 and full-size human ABCA8, which has the two ATP-binding domains, remain unknown. The purpose of the present study was to clarify the tissue expression profiles of ABCA6-like and ABCA1-like subgroup transporters and the functional characteristics of ABCA8 in mouse and human. The tissue distribution of mouse ABCA (mABCA) transporter protein and the changes in mABCA8 protein expression levels in a mouse model of obstructive cholestasis were elucidated by means of quantitative targeted absolute proteomics (QTAP). The transport characteristics were clarified in a HEK293 cell line overexpressing full-size ABCA8 protein. QTAP and immunohistochemical analyses revealed that mABCA transporters exhibited the distinct protein expression patterns in the tissues, and mABCA8b, its mouse orthologue, was abundant in the liver and predominantly distributed in sinusoidal membranes of the hepatocytes. Further, protein expression of mABCA8b was decreased in the mouse cholestasis liver. Changes of mABCA8b expression level in cholestasis were similar to those of mABCA1, a sinusoidal cholesterol efflux transporter. Uptake and efflux assays showed that ABCA8 mediates efflux of [3H]cholesterol and [3H]taurocholate, while it showed no significant efflux activity for [3H]estrone sulfate, [3H]digoxin, [3H]vinblastine, [3H]para-aminohippuric acid, [3H]oleic acid, [14C]nicotine, or [3H]methotrexate. [3H]Cholesterol efflux was increased by extracellularly applied taurocholate. These results suggest that mABCA8b/ABCA8 functions as a sinusoidal efflux transporter for at least cholesterol and taurocholate in mouse and human liver.

Stereoselective Inhibition of Renal Basolateral Human Organic Anion Transporter 3 by Lansoprazole Enantiomers

Lansoprazole, a proton pump inhibitor, potently inhibits human organic anion transporter, hOAT3 (SLC22A8). Lansoprazole has an asymmetric atom in its structure and is clinically administered as a racemic mixture of (R)-and (S)-enantiomers. However, little is known about the stereoselective inhibitory potencies of lansoprazole against hOAT3 and its homolog, hOAT1. In the present study, the stereoselective inhibitory effect of lansoprazole was evaluated using hOAT1-and hOAT3-expressing cultured cells. hOAT1 and hOAT3 transported [¹⁴C]p-aminohippurate and [³H]estrone-3-sulfate (ES) with Michaelis-Menten constants of 29.8 ± 4.0 and 30.1 ± 9.0 µmol/L respectively. Lansoprazole enantiomers inhibited hOAT1- and hOAT3-mediated transport of each substrate in a concentration-dependent manner. The IC₅₀ value of (S)-lansoprazole against hOAT3-mediated transport of [³H]ES (0.61 ± 0.08 µmol/L) was significantly lower than that of (R)-lansoprazole (1.75 ± 0.31 µmol/L). In contrast, stereoselectivity was not demonstrated for the inhibition of hOAT1. Furthermore, (S)-lansoprazole inhibited hOAT3-mediated transport of pemetrexed and methotrexate (hOAT3 substrates) more strongly than the corresponding (R)-lansoprazole. This study is the first to demonstrate that the stereoselective inhibitory potency of (S)-lansoprazole against hOAT3 is greater than that of (R)-lansoprazole. The present findings provide novel information about the drug interactions associated with lansoprazole.

Salivary metabolomics profile of patients with recurrent aphthous ulcer as revealed by liquid chromatography-tandem mass spectrometry.

ObjectiveWe compared the salivary nontargeted metabolite profiles between patients with recurrent aphthous ulcer (RAU) and healthy individuals to investigate the metabolic alterations associated with RAU.MethodsSaliva samples were collected from 45 patients with RAU and 49 healthy individuals, and the salivary metabolites were quantified using liquid chromatography–tandem mass spectrometry. The metabolomic profiles were then analyzed using multivariate and univariate statistical methods, and enrichment of the metabolites in various biological pathways was assessed.ResultsIn total, 206 significant differentiating metabolites (Wilcoxon test, false discovery rate [FDR] of <0.05) were identified between patients with RAU and healthy individuals. These metabolites were implicated in tryptophan metabolism, steroid hormone biosynthesis, and other metabolic pathways. Two commonly circulating steroids, estrone sulfate and dehydroepiandrosterone sulfate, were significantly lower in the saliva of patients with RAU (Wilcoxon test, FDR < 0.05, power > 0.9). Principal component analysis and partial least-squares discriminant analysis revealed metabolic perturbations involving RAU, and receiver operating characteristic curve analysis with several metabolites showed good diagnostic ability for RAU.ConclusionsThe results of this study indicate that patients with RAU are characterized by metabolic imbalances. Psychogenic factors, endocrinopathies, and immunosuppression may contribute to the onset of RAU.

Circulating Hormones and Mammographic Density in Premenopausal Women.

Prior research suggests that several endogenous hormones in premenopausal women are associated with breast cancer risk; however, few studies have evaluated associations of endogenous hormones with mammographic density (MD) in premenopausal women. We conducted a cross-sectional study of plasma hormone levels in relation to MD among 634 cancer-free premenopausal women in the Nurses' Health Study II. We measured percent MD from screening mammograms using a computer-assisted method. We assayed estradiol, estrone, and estrone sulfate in blood samples timed in early follicular and mid-luteal phases of the menstrual cycle as well as testosterone, androstenedione, progesterone, dehydroepiandrosterone (DHEA), DHEA sulfate, sex hormone-binding globulin (SHBG), and anti-Müllerian hormone in luteal or untimed samples. We used multivariable linear regression to quantify the association of %MD with quartiles of each hormone, adjusting for age, body mass index, and breast cancer risk factors. Women in the highest quartile of follicular estradiol levels had significantly greater %MD compared to those in the lowest quartile [difference, 6.7 percentage points; 95% confidence interval (CI) 2.2, 11.3; p-trend < 0.001]. Similar associations were observed for follicular free estradiol but not luteal-phase estradiol. Also, women in the top (vs. bottom) quartile of free testosterone had significantly lower %MD (difference, - 4.7; 95% CI - 8.7, - 0.8; p-trend = 0.04). Higher SHBG was significantly associated with higher percent MD (difference, 4.8; 95% CI 1.1, 8.6; p-trend = 0.002). Percent MD was not strongly associated with other measured hormones. Results were similar in analyses that excluded women with anovulatory cycles. Our findings suggest that follicular estradiol and SHBG may play an important role in premenopausal percent MD.

New possibilities for pregnancy diagnosis in ruminants: Limitations, advantages, use

Early pregnancy diagnosis in ruminants, especially in high production herds, is one of the most important components of reproduction management. Reducing the time between insemination and the exclusion or confirmation of pregnancy is of major economic importance. That is why the traditional method of pregnancy examination by transrectal palpation is increasingly complemented by additional tests, such as ultrasonography. An alternative to these methods of pregnancy diagnosis are also simple field tests. The best known are tests for progesterone and estrone sulphate concentrations. Over the last few years, the measuring of pregnancy-associated glycoproteins (PAGs) has also been gaining popularity. In cattle, this method can be used as early as the 28th day of pregnancy, when the plasma concentration of PAGs exceeds 1ng / ml. Maximum values of pregnancy-associated glycoproteins are observed about day 240 after fertilization. After calving, their level quickly decreases. In sheep, the concentration of PAGs increases significantly in the 3rd and 4th weeks of gestation and reaches its maximum level around the 9th week. In goats, the concentration of PAGs differs between races, but its measurement can be quite a reliable indirect method of pregnancy diagnosis. The PAGs value in this species grows until about the 8th week after insemination and, depending on the breed, reaches a maximum value of 50 to 69 ng/ml. One limitation for the use of PAGs field tests may be false positives which occur after the death of the embryo. Similarly, an increased PAGs concentration can persists for up to about 70 days after calving. Moreover, the PAGs concentration is also affected by the health, age and milk production of the female. The advantages of field tests are the simplicity of performance, the ease of reading and interpreting the results and the short time needed to complete the entire procedure. Field tests based on the commonly used ELISA method are characterized by low invasiveness (blood, milk), combined with high sensitivity and specificity. Their rapid application under field conditions makes them an excellent extension of diagnostic capabilities, especially in large herds of cows, .

Inhibition of human kynurenine aminotransferase isozymes by estrogen and its derivatives

The kynurenine aminotransferase (KAT) enzymes are pyridoxal 5′-phosphate-dependent homodimers that catalyse the irreversible transamination of kynurenine into kynurenic acid (KYNA) in the tryptophan metabolic pathway. Kynurenic acid is implicated in cognitive diseases such as schizophrenia, and several inhibitors have been reported that selectively target KAT-II as it is primarily responsible for kynurenic acid production in the human brain. Not only is schizophrenia a sexually dimorphic condition, but women that have schizophrenia have reduced estrogen levels in their serum. Estrogens are also known to interact in the kynurenine pathway therefore exploring these interactions can yield a better understanding of the condition and improve approaches in ameliorating its effects. Enzyme inhibitory assays and binding studies showed that estradiol disulfate is a strong inhibitor of KAT-I and KAT-II (IC50: 291.5 μM and 26.3 μM, respectively), with estradiol, estradiol 3-sulfate and estrone sulfate being much weaker (IC50 > 2 mM). Therefore it is possible that estrogen levels can dictate the balance of kynurenic acid in the brain. Inhibition assay results and modelling suggests that the 17-sulfate moiety in estradiol disulfate is very important in improving its potency as an inhibitor, increasing the inhibition by approximately 10–100 fold compared to estradiol.

Exploiting whole genome sequence data to fine map and characterize candidate genes within a quantitative trait loci region affecting androstenone on porcine chromosome 5.

SummaryMale piglets are routinely castrated to eliminate boar taint. However, this treatment is undesirable, and alternative approaches, including genetic strategies to reduce boar taint, are demanded. Androstenone is one of the causative agents of boar taint, and a QTL region affecting this pheromone has previously been reported on SSC5: 22.6–24.8 Mb in Duroc. The QTL region is one of the few reported for androstenone that does not simultaneously affect levels of other sex steroids. The main objective of this study was to fine map this QTL. Whole genome sequence data from 23 Norwegian Duroc boars were analyzed to detect new polymorphisms within the QTL region. A subset of 161 SNPs was genotyped in 834 Duroc sires and analyzed for association with androstenone in adipose tissue and testosterone, estrone sulphate and 17β‐estradiol in blood plasma. Our results revealed 100 SNPs significantly associated with androstenone levels in fat (P < 0.001) with 94 of the SNPs being in strong linkage disequilibrium in the region 23.03–24.27 Mb. This haplotype block contains at least four positional candidate genes (HSD17B6,SDR9C7,RDH16 and STAT6) involved in androstenone biosynthesis. No significant associations were found between any of the SNPs and levels of testosterone and estrogens, confirming previous findings. The amount of phenotypic variance explained by single SNPs within the haplotype block was as high as 5.4%. As the SNPs in this region significantly affect levels of androstenone without affecting levels of other sex steroids, they are especially interesting as genetic markers for selection against boar taint.

Estrogen Metabolism in Abdominal Subcutaneous and Visceral Adipose Tissue in Postmenopausal Women.

In postmenopausal women, adipose tissue (AT) levels of estrogens exceed circulating concentrations. Although increased visceral AT after menopause is related to metabolic diseases, little is known about differences in estrogen metabolism between different AT depots. We compared concentrations of and metabolic pathways producing estrone and estradiol in abdominal subcutaneous and visceral AT in postmenopausal women. AT and serum samples were obtained from 37 postmenopausal women undergoing surgery for nonmalignant gynecological reasons. Serum and AT estrone, estradiol, and serum estrone sulfate (E1S) concentrations were quantitated using liquid chromatography-tandem mass spectrometry. Activity of steroid sulfatase and reductive 17β-hydroxysteroid dehydrogenase enzymes was measured using radiolabeled precursors. Messenger RNA (mRNA) expression of estrogen-converting enzymes was analyzed by real-time reverse transcription quantitative polymerase chain reaction. Estrone concentration was higher in visceral than subcutaneous AT (median, 928 vs 706 pmol/kg; P = 0.002) and correlated positively with body mass index (r = 0.46; P = 0.011). Both AT depots hydrolyzed E1S to estrone, and visceral AT estrone and estradiol concentrations correlated positively with serum E1S. Compared with visceral AT, subcutaneous AT produced more estradiol from estrone (median rate of estradiol production, 1.02 vs 0.57 nmol/kg AT/h; P = 0.004). In visceral AT, the conversion of estrone to estradiol increased with waist circumference (r = 0.65; P = 0.022), and estradiol concentration correlated positively with mRNA expression of HSD17B7 (r = 0.76; P = 0.005). Both estrone and estradiol production in visceral AT increased with adiposity, but estradiol was produced more effectively in subcutaneous fat. Both AT depots produced estrone from E1S. Increasing visceral adiposity could increase overall estrogen exposure in postmenopausal women.

Interaction between rhein acyl glucuronide and methotrexate based on human organic anion transporters

Rhein, a major bioactive compound of many medicinal herbs and the prodrug of diacerein, is often used with low dose of methotrexate as drug combination to treat rheumatoid arthritis. In this study, potential drug-drug interaction between methotrexate and rhein was investigated based on organic anion transporters (OAT). Our study demonstrated that rhein acyl glucuronide (RAG), the major metabolite of rhein in the human blood circulation, significantly inhibited the uptake of p-aminohippurate in hOAT1 transfected cells with IC50 value of 691 nM and estrone sulfate uptake in hOAT3 transfected cells with IC50 value of 78.5 nM. As the substrate of both hOAT1 and hOAT3, the methotrexate transport was significantly inhibited by RAG in hOAT1 transfected cells at 50 μM and hOAT3 transfected cells at 1 μM by 69% and 87%, respectively. Further in vivo study showed that after co-administrated with RAG in rats the AUC0-24 values of methotrexate increased from 3109 to 5370 ng/mL*hr and the t1/2 was prolonged by 40.5% (from 7.4 to 10.4 h), demonstrating the inhibitory effect of RAG on methotrexate excretion. In conclusion, rhein acyl glucuronide could significantly decrease the transport of methotrexate by both hOAT1 and hOAT3. The combination use of rhein, diacerein or other rhein-containing herbs with methotrexate may cause obvious drug-drug interaction and require close monitoring for potential drug interaction in clinical practice.