Estrone Sulfate Research Articles

Constituents of Passiflora incarnata, but Not of Valeriana officinalis, Interact with the Organic Anion Transporting Polypeptides (OATP)2B1 and OATP1A2.

Herbal medication used in the treatment of sleep disorders and anxiety often contain extracts of Valeriana officinalis or Passiflora incarnata. Valerenic acid in V.officinalis and apigenin, orientin, and vitexin in P. incarnata are thought to contribute to their therapeutic effect. It was the aim of this study to test whether these constituents of herbal extracts are interacting with the uptake of estrone 3-sulfate, pregnenolone sulfate, and dehydroepiandrosterone sulfate mediated by the uptake transporters organic anion transporting polypeptide 2B1 (OATP2B1) or organic anion transporting polypeptide 1A2 (OATP1A2). Madin-Darby canine kidney cells overexpressing OATP2B1 or OATP1A2 were used to determine the influence of the constituents on the cellular accumulation of the sulfated steroids. Subsequently, competitive counterflow experiments were applied to test whether identified inhibitors are also substrates of the transporters. Valerenic acid only interacted with OATP2B1, whereas apigenin, orientin, and vitexin interacted with OATP2B1 and OATP1A2. Competitive counterflow revealed that orientin is a substrate of both transporters, while apigenin was transported by OATP1A2 and vitexin by OATP2B1. In a next step, commercially available P. incarnata preparations were assessed for their influence on the transporters, revealing inhibition of transporter-mediated estrone 3-sulfate uptake. HPLC-UV-MS analysis confirmed the presence of orientin and vitexin in these preparations, thereby suggesting that these constituents are involved in the interaction. Our data indicate that constituents of P. incarnata may alter the function of OATP2B1 and OATP1A2, which could affect the uptake of other compounds relying on uptake mediated by the transporters.

Ultraviolet radiation as a predictor of sex hormone levels in postmenopausal women: A European multi-center study (ECRHS)

BackgroundSolar ultraviolet radiation (UVR) affects the body through pathways that exhibit positive as well as negative health effects such as immunoregulation and vitamin D production. Different vitamin D metabolites are associated with higher or lower concentrations of estrogens and may thus alter the female sex hormone balance. ObjectiveTo study whether exposure to UVR, as a modifiable lifestyle factor, is associated with levels of sex hormones (17β-estradiol, estrone, estrone 3-sulfate, testosterone, dehydroepiandrosterone sulfate), gonadotropins (follicle stimulating hormone, luteinizing hormone) as well as sex hormone binding globulin in postmenopausal women, and thus investigate whether managing UVR exposure can influence the hormone balance, with potential benefits for the biological aging process. MethodsThe study included 580 postmenopausal women from six European countries, participating in the European Community Respiratory Health Survey (2010–2014). Average UVR exposure during the month before blood sampling was estimated based on personal sun behavior and ambient levels. Hormone concentrations were measured in serum using state-of-the-art methods. Subsequently we applied linear mixed-effects models, including center as random intercept, hormone concentrations (one at a time) as outcome and UVR, age, skin type, body mass index, vitamin D from dietary sources, smoking, age at completed full-time education and season of blood sampling as fixed-effect predictors. ResultsOne interquartile range increase in UVR exposure was associated with decreased levels of 17β-estradiol (-15.6 pmol/L, 95 % Confidence Interval (CI): -27.69, -3.51) and estrone (-13.36 pmol/L, 95 % CI: -26.04, -0.68) and increased levels of follicle stimulating hormone (9.34IU/L, 95 % CI: 2.91, 15.77) and luteinizing hormone (13.86 IU/daL, 95 % CI: 2.48, 25.25). ConclusionsExposure to UVR is associated with decreased estrogens and increased gonadotropins in postmenopausal women, a status associated with osteoporosis, lung function decline and other adverse health effects. This study indicates that managing UVR exposure has potential to influence the hormone balance and counteract adverse health conditions after menopause.

MiRNA-mediated alteration of sulfatase modifying factor 1 expression using self-assembled branched DNA nanostructures.

Sulfatase enzymes catalyze sulfate ester hydrolysis, thus deficiencies of sulfatases lead to the accumulation of biomolecules resulting in several disorders. One of the important sulfatases is estrone sulfatase that converts inactive estrone sulfate to active estradiol. Posttranslational modification of highly conserved cysteine residue leads to unique formylglycine in the active site of sulfatases being critical for its catalytic activity. The essential factor responsible for this modification of sulfatase is Sulfatase-Modifying Factor 1 (SUMF1). The role of estrone sulfatase is well evident in breast cancer progression. However, the function and regulation of SUMF1 in cancer are not studied. In the present study, for the first time, we have assessed the expression of SUMF1 in breast cancer and report the oncogenic behavior upon overexpression of SUMF1. Although increased expression or activity of SUMF1 is anticipated based on its function, the expression of SUMF1 was found to be reduced in breast cancer cells at both mRNA and protein levels. An estrogen receptor (ER) dependent expression of SUMF1 was observed and higher SUMF1 expression is associated with improved breast cancer patient survival in ER-positive cases. However, high SUMF1 expression leads to reduced median survival in ER-negative breast cancer patients. Putative binding sites for miRNAs-106b-5p, 128-3p and 148b-3p were found at 3′-UTR of SUMF1. Since self-assembled branched DNA (bDNA) structures have emerged as a highly efficient strategy for targeting multiple miRNAs simultaneously, we studied the alteration in SUMF1 expression using bDNA nanostructures with a complementary sequence to miRNAs. The findings suggest the involvement of co-regulators and repressors in miRNA-mediated SUMF1 expression in breast cancer cells and reveal the therapeutic potential of SUMF1 in endocrine-related malignancies.

Changes in circulating concentrations of testosterone and estrone sulfate after human chorionic gonadotropin administration and subsequent to castration of 2-year-old stallions

Reproductive steroids testosterone (T) and estrone sulfate (E1S) are used as diagnostic markers for cryptorchidism in horses. The human chorionic gonadotropin (hCG) stimulation test is used as a diagnostic aid because administration of this hormone results in greater incremental differences in circulating steroid concentrations. Thoughts regarding optimal sampling times following hCG administration, however, are inconsistent. Additionally, determination of half-life of these steroids is important in postsurgical samples to confirm complete removal of testicular tissue. Objectives of this study, therefore, were to determine optimal sampling periods for peak T and E1S after hCG administration and half-life of these steroids after castration. Eight pony stallions were randomly assigned to control or treatment groups (5000 IU hCG). Blood samples were collected following hCG administration. Subsequently, stallions were castrated and blood samples were collected post-castration. The T concentrations were greatest at 72 h after hCG and were greater (P < 0.02) in samples from hCG-treated than control animals: 9,903.4 ± 384 and 784.0 ± 192 pg/mL, respectively (Mean ± SEM). The T concentrations were also greater at 1, 12, 24, 48 and 96 h. The E1S concentrations did not change after administration of hCG. The T response to hCG administration was biphasic with a maximal response between 48–96 h after administration. Half-lives of T and E1S were 1.1 and 0.7 h, respectively, and concentration of T and E1S was similar to that of geldings at 24 h post-castration, which, therefore, should be considered an optimal time to ensure complete castration has occurred.

PSI-30 Evaluation of urine estrone sulfate (P-Test) in beef cattle as an alternative pregnancy detection method

Abstract Pregnancy detection in cattle can be expensive and labor intensive to producers. A simple, cost-efficient method of determining early pregnancy, chute side, is lacking within the industry. This study tested various proven pregnancy detection methods against an alternative method. Pregnancy was assessed by ultrasonography, blood serum pregnancy-specific protein B (PSPB), and urine estrone sulfate (“P-Test”). A fixed timed AI (FTAI) protocol was conducted on 14 predominantly British cattle housed at Tarleton State University in Stephenville, TX. Cows were synchronized using the co-synch plus 7 day CIDR protocol, with PGF injection of d 7. Heifers were synchronized similarly with the exception of GnRH injection on d 1. Estrotech patch scores (1 – 4, 1 showing little signs of estrus to 4 presenting signs of estrus) were utilized to indicate estrus activity prior to FTAI (21.4% vs. 78.6% females scored 1 vs. 4, respectively). FTAI was performed on protocol d 10 along with a 2mL injection of GnRH. Serum for PSPB analysis was collected at d 30 and 60 post insemination, while urine was sampled on d 60. Overall 53.8% (ultrasonography) and 71.4% (PSPB) of cattle were determined to be pregnant at d 30 post FTAI. Chi squared analysis proved that PSPB and ultrasound were similar at detecting pregnancy (P = 0.04). At d 60 “P-Test” color varied indicating differing levels of estrone sulfate. A t-test revealed increased PSPB from d 30–60 post FTAI (P &amp;lt; 0.0001); however, “P-Test” could not predict similar results (P = 0.655). Data suggest the “P-Test” is not a consistent method to diagnose early pregnancy. Future studies may be warranted to investigate a more desirable time point for utilizing the chute side “P-Test” as a reliable method to determine pregnancy.

Impact of sex hormones dysregulation and adiposity on the outcome of postmenopausal breast cancer patients.

Epidemiological studies demonstrated that, in postmenopausal women, high circulating levels of testosterone, especially when associated with weight gain, positively correlated with an increased risk of breast cancer because of the augmented production of oestrogen via testosterone aromatization in the adipose tissue. Besides, growing evidence suggests that sulfatase can increase the tissue concentration of bioactive estradiol through the reconversion of estrone sulfate, thus providing a favourable milieu for epithelial cells expressing the oestrogen receptor. In this review, we will discuss how the "obesity-insulin-testosterone" connection and the abnormal production of bioactive oestrogen - as a result of the conversion of the androgens by aromatase and the estrone reconversion by sulfatase-, may affect the response to hormone therapy and the outcome of postmenopausal breast cancer patients, and how a combined therapy including metformin, anti-inflammatory drugs, and aromatase/sulfatase inhibitors could successfully improve patient's outcome.

Urinary reproductive hormones influence seed germination within diluted urine of heifers: alternative pregnancy diagnostic method

Experimental non-invasive pregnancy diagnostic techniques, such as seed germination testing in diluted urine, may serve as an alternative to standardized pregnancy diagnostic methods, but scientific validation of these methods is required. This study aimed to use Czech Fleckvieh heifers to investigate the influence of urinary reproductive hormones (oestrone sulphate, 17β-oestradiol, and pregnanediol3-glucuronide) on the germination success of seeds placed within their diluted urine, and further to verify the reliability of seed germination test for pregnancy diagnosis in this species. Mung bean and wheat seeds were germinated in two urine-water dilutions (1:4 and 1:14) for three days, using urine samples obtained from either pregnant or non-pregnant heifers. Germinated seeds were counted daily, and the shoot lengths were measured three days after placement in the urine. Levels of urinary reproductive hormones were determined using competitive heterogeneous enzyme immunoassays (EIAs). Despite the dilution rate used, final results indicated that the urine from pregnant heifers inhibited germination and growth in mung beans only. On the contrary, wheat germination rate was higher within the urine from pregnant females on days 1 and 2, when using a 1:14 dilution rate. For both seed species, correlations between urinary hormone profiles and seed germination parameters were found, depending on the day of the experiment and the rate of dilution used. The shoot lengths of mung bean seeds were significantly (P &lt; 0.05) and negatively correlated with the profiles of all hormones analysed from the urine samples. Thus, urinary reproductive hormones influence seed germination and growth rate of wheat and mung beans, indicating the potential for this technique to be used for pregnancy determination in heifers.

Bisphenol A exposure and reduced male sex hormone levels in a Norwegian population

Background: Bisphenol A (BPA) is used in production of polycarbonate plastics and epoxy resins. Despite endocrine disrupting properties and suspected impact on male reproductive health BPA is still frequently used in a wide variety of consumer products. Few studies have addressed BPA exposure and steroid hormones in a general population sample. We aimed to investigate whether BPA exposure is associated with steroid hormone concentrations (17β-estradiol, estrone, estrone 3-sulfate, progesterone, progesterone 17α-OH-progesterone, testosterone, androstenedione, dehydroepiandrosterone sulfate (DHEAS), aldosterone, cortisone and cortisol) in a healthy Norwegian population. Methods: The study included 205 women and 232 men aged 18-48 years, participating in the RHINESSA study (2014-15) in Norway. Urine concentration of BPA and steroid hormones in serum were measured using liquid chromatography - mass spectrometry. We applied linear mixed effects random intercept models with sex hormone levels (one at a time) as outcome, BPA concentration as exposure and adjusted for age, sex, BMI, smoking and time of day for urine and blood sampling. Results: Bisphenol A was detected in 96% of the urine samples; and median concentration was 1.32 ng/mL (5th-95th percentile: 0.50-5.15, max: 21.9 ng/mL). Increasing exposure to BPA (per ng/mL) was associated with decreasing levels of testosterone (-11.72 pmol/cL, 95% Confidence Interval (CI): -22.93, -0.51) and DHEAS (-6.83 nmol/cL, 95% CI: -12.72, -0.94) for men and women combined. Restricting the analyses to men, increasing exposure to BPA was associated with decreasing levels of 17β-estradiol (-0.88 pmol/L, 95% CI: -1.72, -0.04) and with elevated endogenous aldosterone levels (4.32 pmol/L, 95% CI: 0.91, 7.73). Conclusions: The urinary biomarker concentration of BPA is ubiquitous, but relatively low. BPA was associated with an altered hormone profile, in particular with reduced levels of androgens as well as with 17β-estradiol which is synthesized from androgen precursors. Whether the association is of clinical relevance needs to be elucidated.

Determination of estrone sulfate, testosterone, androstenedione, DHEAS, cortisol, cortisone, and 17α-hydroxyprogesterone by LC-MS/MS in children and adolescents

Quantitation of endogenous steroids and their precursors is essential for diagnosis of a wide range of endocrine disorders. Usually, these analyses have been carried out using immunoassays. However, immunoassays often overestimate concentrations due to assay interference by other endogenous steroids, especially for low concentrations. Mass spectrometry based methods offer superior specificity, accuracy, and sensitivity. We therefore present a liquid chromatography–tandem mass spectrometry (LC-MS/MS) method with automated sample preparation for determination of 17α-hydroxyprogesterone (17OHP), cortisol, cortisone, dehydroepiandrosterone sulfate (DHEAS), androstenedione (A4), testosterone (T), and estrone sulfate (E1S). Samples were prepared using protein precipitation and 96-well filter plates, fully automated in a pipetting robot and analyzed by LC-MS/MS. Serum samples from 187 healthy children and adolescents aged 5-18 years were used to study hormone changes in relation to sex and pubertal stage. Lower limit of quantification for 17OHP was 0.7 nmol/L, for cortisol 11 nmol/L, for cortisone 2 nmol/L, for DHEAS 0.1 µmol/L, and for A4, T, and E1S, 0.2 nmol/L. This study showed a general increase in 17OHP, DHEAS, A4, T and E1S in both genders during puberty. In boys, A4 and T increased significantly throughout pubertal development. Girls had significantly higher A4 and E1S concentrations, while boys had higher T concentrations. No sex- or puberty-specific differences were seen in cortisol or cortisone concentrations. To the best of our knowledge, this is the first presentation of changes in serum E1S concentrations during pubertal development in healthy children.

Effects of doxorubicin associated with amniotic membrane stem cells in the treatment of canine inflammatory breast carcinoma (IPC-366) cells

BackgroundTumours in mammary glands represent the most common neoplasia in bitches, as in humans. This high incidence results in part from the stimulation of sex hormones on these glands. Among mammary tumours, inflammatory carcinoma is the most aggressive, presenting a poor prognosis to surgical treatment and chemotherapy. One of the most widely used chemotherapy drugs for breast cancer treatment is doxorubicin (DOXO). Alternative therapies have been introduced in order to assist in these treatments; studies on treatments using stem cells have emerged, since they have anti-inflammatory and immunomodulatory properties. The aim of this study was to evaluate the effects of DOXO and canine amniotic membrane stem cells (AMCs) on the triple-negative canine inflammatory mammary carcinoma cell line IPC-366.MethodsFour experimental groups were analysed: a control group without treatment; Group I with DOXO, Group II with AMC and Group III with an association of DOXO and AMCs. We performed the MTT assay with DOXO in order to select the best concentration for the experiments. The growth curve was performed with all groups (I-III) in order to verify the potential of treatments to reduce the growth of IPC-366. For the cell cycle, all groups (I-III) were tested using propidium iodide. While in the flow cytometry, antibodies to progesterone receptor (PR), estrogen receptor (ER), PCNA, VEGF, IL-10 and TGF-β1 were used. For steroidogenic pathway hormones, an ELISA assay was performed.ResultsThe results showed that cells treated with 10 µg/mL DOXO showed a 71.64% reduction in cellular growth after 72 h of treatment. Reductions in the expression of VEGF and PCNA-3 were observed by flow cytometry in all treatments when compared to the control. The intracellular levels of ERs were also significantly increased in Group III (4.67% vs. 27.1%). Regarding to the levels of steroid hormones, significant increases in the levels of estradiol (E2) and estrone sulphate (S04E1) were observed in Groups I and III. On the other hand, Group II did not show differences in steroid hormone levels in relation to the control. We conclude that the association of DOXO with AMCs (Group III) promoted a reduction in cell growth and in the expression of proteins related to proliferation and angiogenesis in IPC-366 triple-negative cells.ConclusionsThis treatment promoted ER positive expression, suggesting that the accumulated oestrogen conducted these cells to a synergistic state, rendering these tumour cells responsive to ERs and susceptible to new hormonal cancer therapies.

Functional Characterization Reveals the Significance of Rare Coding Variations in Human Organic Anion Transporting Polypeptide 2B1 (SLCO2B1).

The organic anion transporting polypeptide 2B1 (OATP2B1), which is encoded by the SLCO2B1 gene, plays important roles in the absorption and disposition of its substrate drugs. Nonsynonymous variations of SLCO2B1 change its amino acid sequence and may alter its function. However, so far, very few genetic variants of SLCO2B1 have been functionally characterized. In the present study, first of all, 14 nonsynonymous single nucleotide variants (SNVs) of SLCO2B1 have been identified from the dbSNP database. Then, human embryonic kidney (HEK293) cells were employed as the expression system and functional studies were carried out for these 14 SNVs using substrates 4',5'-dibromofluorescein (DBF), estrone-3-sulfate (E3S), atorvastatin, and rosuvastatin. Our results showed that four nonsynonymous rare variants, namely, SLCO2B1 c.332G > A (p.R111Q), c.1184C > A (p.P395H), c.1624G > A (p.V542M), and c.1998C > A (p.F666L), have great effect on the function of OATP2B1. Surface biotinylation and immunoblot analysis indicated that the variant c.1184C > A (p.P395H) almost completely disrupted OATP2B1's expression on the plasma membrane. According to the three-dimensional structural model of OATP2B1 we developed, these four mutated residues are not located at the substrate binding region of OATP2B1. Their significant effect on the function of OATP2B1 could probably be attributed to jeopardizing OATP2B1's surface expression as exemplified by c.1184C > A (p.P395H), altering the transporter's overall structure and affecting its interactions with other proteins or the lipid bilayer. Taken together, our results demonstrated that rare coding variants could have a great impact on the function and expression of OATP2B1.

Food Additives as Inhibitors of Intestinal Drug Transporter OATP2B1.

Food additives are compounds that are added to food and beverage to improve the taste, color, preservation, or composition. Generally, food additives are considered safe for human use due to safety evaluations conducted by food safety authorities and high safety margins applied to permitted usage levels. However, the interaction potential of food additives with simultaneously administered medication has not received much attention. Even though many food additives are poorly absorbed into systemic circulation, high concentrations could exist in the intestinal lumen, making intestinal drug transporters, such as the uptake transporter organic anion transporting polypeptide 2B1 (OATP2B1), a possible site of food additive-drug interactions. In the present work, we aimed to characterize the interaction of a selection of 25 food additives including colorants, preservatives, and sweeteners with OATP2B1 in vitro. In human embryonic kidney 293 (HEK293) cells transiently overexpressing OATP2B1 or control, uptake of dibromofluorescein was studied with and without 50 μM food additive at pH 7.4. As OATP2B1 displays substrate- and pH-dependent transport functions and the intraluminal pH varies along the gastrointestinal tract, we performed the studies also at pH 5.5 using estrone sulfate as an OATP2B1 substrate. Food additives that inhibited OATP2B1-mediated substrate transport by ≥50% were subjected to dose-response studies. Six colorants were identified and validated as OATP2B1 inhibitors at pH 5.5, but only three of these were categorized as inhibitors at pH 7.4. One sweetener was validated as an inhibitor under both assay conditions, whereas none of the preservatives exhibited ≥50% inhibition of OATP2B1-mediated transport. Extrapolation of computed inhibitory constants (Ki values) to estimations of intestinal food additive concentrations implies that selected colorants could inhibit intestinal OATP2B1 also in vivo. These results suggest that food additives, especially colorants, could alter the pharmacokinetics of orally administered OATP2B1 substrate drugs, although further in vivo studies are warranted to understand the overall clinical consequences of the findings.

The Membrane Transporter OAT7 (SLC22A9) Is Not a Susceptibility Factor for Osteoporosis in Europeans

Bone production, maintenance, and modeling are a well-balanced process involving mineralization by osteoblasts and resorption by osteoclasts. Sex steroid hormones, including their conjugated forms, contribute majorly to maintaining this balance. Recently, variants in the SLC22A9 gene have been associated with osteoporosis in Korean females. We had recently shown that SLC22A9, encoding organic anion transporter 7 (OAT7), is an uptake transporter of estrone sulfate and identified several genetic variants in Europeans leading to functional consequences in vitro. We therefore hypothesized that SLC22A9 genetic variants may contribute to the pathophysiology of osteoporosis in Europeans. To test this hypothesis, we examined the associations of SLC22A9 variants with bone quality, fractures, and bone turnover markers. We genotyped SLC22A9 variants in 5,701 (2,930 female) subjects (age range, 20–93 years) extracted from the population-based Study of Health in Pomerania (SHIP and SHIP-TREND) covered by the Illumina Infinium HumanExome BeadChip version v1.0 (Exome Chip). Descriptive data (e.g., history of fractures), ultrasonography of the calcaneus, as well as serum concentrations of carboxy-terminal telopeptide of type I collagen, amino-terminal propeptide of type I procollagen, and vitamin D were determined. Comprehensive statistical analyses revealed no association between low-frequency and rare SLC22A9 variants and bone quality, fractures, and bone turnover markers. Our results indicate that single genetic SLC22A9 variants do not have a major impact on osteoporosis risk prediction in Europeans, yet findings need to be replicated in larger-scale studies.

Investigation of Fluorescent Substrates and Substrate-Dependent Interactions of a Drug Transporter Organic Anion Transporting Polypeptide 2B1 (OATP2B1).

In this study, we investigated organic anion transporting polypeptide 2B1 (OATP2B1)-mediated uptake of fluorescent anions to better identify fluorescent substrates for in vitro OATP2B1 assays. The OATP2B1 is involved in the intestinal absorption and one of the pharmacokinetic determinants of orally administered drugs. A microplate reader was used to determine the cellular accumulation of the fluorescent compounds into the OATP2B1 or the empty vector-transfected HEK293 cells. Two types of derivatives were found to be OATP2B1 substrates: heavy halogenated derivatives, such as 4',5'-dibromofluorescein (DBF), and carboxylated derivatives, such as 5-carboxyfluorescein (5-CF). The DBF and 5-CF were transported in a time and concentration-dependent manner. The DBF was transported at a broad pH (pH6.5-8.0) while 5-CF was transported at an acidic pH (pH5.5-6.5). The Km values were 0.818 ± 0.067μM at pH7.4 for DBF and 8.56 ± 0.41μM at pH5.5 for 5-CF. The OATP2B1 inhibitors, including atorvastatin, bromosulfophthalein, glibenclamide, sulfasalazine, talinolol, and estrone 3-sulfate, inhibited the DBF and the 5-CF transport. Contrastively, testosterone, dehydroepiandrosterone sulfate, and progesterone inhibited the DBF transport but stimulated the 5-CF transport. Natural flavonoid aglycones, such as naringenin and baicalein, also exhibited substrate-dependent effects in this manner. We found two fluorescein analogs, DBF and 5-CF as the OATP2B1 substrates that exhibited substrate-dependent interactions.

OATP1A2 and OATP2B1 Are Interacting with Dopamine-Receptor Agonists and Antagonists.

Interaction with the dopaminergic system in the central nervous system is either therapeutically intended or it is a side effect. In both cases, dopamine-receptor agonists (DRA) like the ergoline derivative bromocriptine and dopamine-receptor antagonists (DRAn) like metoclopramide have to cross the blood-brain barrier (BBB). The organic anion transporting polypeptides (OATP) 1A2 and 2B1 are cellular uptake carriers for a variety of endogenous and xenobiotic compounds. As both transporters are expressed in endothelial cells of the BBB, the aim of the present study was to determine whether the DRA bromocriptine, cabergoline, and pergolide and the DRAn metoclopramide and domperidone are interacting with OATP1A2 and 2B1 and could therefore be candidate genes modifying wanted and unwanted effects of these drugs. Localization of both transporters in the brain was confirmed using LC-MS/MS and immunofluorescence stainings. For the functional studies, MDCKII cells stably expressing OATP1A2 or 2B1 were used. Initial interaction studies with the well-characterized transporter substrate estrone 3-sulfate revealed that all tested compounds except pergolide inhibit the transport function of both proteins with the most potent effect for bromocriptine (IC50 = 2.2 μM (OATP1A2) and IC50 = 2.5 μM (OATP2B1)). Further studies using the indirect competitive counterflow method identified bromocriptine, cabergoline, and domperidone as substrates of both transporters, whereas metoclopramide was only transported by OATP1A2. These findings were verified for domperidone by direct measurements using its tritium-labeled form as a tracer. Moreover, the transporter-mediated uptake of this compound was sensitive to the OATP1A2 and OATP2B1 inhibitor naringin. In conclusion, this study suggests that OATP1A2 and 2B1 may play a role in the uptake of DR agonists and antagonists into the brain.

Functional Characterization of Position 271 in NTCP, a Predicted Rheostat Location

BackgroundHuman Na+/taurocholate cotransporting polypeptide (NTCP) is a sodium dependent bile acid transporter expressed at the basolateral membrane of human hepatocytes. It is important for the enterohepatic circulation of bile acids, such as taurocholate (TCA), but it also transports other compounds including estrone‐3‐sulfate (E3S) and rosuvastatin. We previously identified a rheostat position at a naturally occurring polymorphism, S267F. That is, when other amino acids were substituted into this position, progressive changes in function were observed.AimThe purpose of the current study is to determine whether position N271, a predicted rheostat, is indeed another rheostat position in NTCP.MethodsThe crystal structures of two bacterial NTCP homologs were used to model the structure of human NTCP in the inward‐open and outward‐open conformations. Mutations were then introduced into the structural models and the energetic effect on protein stability was evaluated using the Rosetta software. Based on these calculations we predicted that N271 is a rheostat. Mutants for position N271 were generated using site‐directed mutagenesis and the resulting proteins were transiently expressed in HEK293 cells. The functions of the mutants were characterized by measuring uptake of radiolabeled model substrates: [3H]‐taurocholate, [3H]‐estrone‐3‐sulfate, and [3H]‐rosuvastatin. Plasma membrane expression levels were determined by surface biotinylation assays.ResultsInitial transport studies using nanomolar concentrations of TCA, E3S, and rosuvastatin indicated a variety of intermediate functional outcomes for the mutants. Furthermore, this alteration in function was substrate dependent, which is consistent with our findings for S267. Some mutants, such as N271A, transport substrates similar to wild‐type NTCP, while others, like N271K, show variation depending on the substrate. N271P consistently transports all substrates minimally. In addition, there is no correlation between the initial uptake results and the Rosetta energies.Summary and ConclusionsInitial transport studies demonstrate that position N271 is a rheostat position, as predicted by the alteration in Rosetta energy scores. However, there was no correlation between the calculated energy scores and the functional results. This suggests that functional outcomes of specific amino acid replacements at position N271 may arise from more complex conformational changes than were captured by the two modeled states. Additional experiments should help to determine to what extent the observed change in function is due to variations in the substrate affinity, the turnover number or the transport capacity of the mutants.Support or Funding InformationP30 GM118247, GM077336, and W. M. Keck Foundation

Late gestation heat stress in dairy cows: Effects on dam and daughter

In dairy cattle, the final weeks before parturition are physiologically challenging and an important determinant of subsequent production performance. External stressors should be carefully managed during this period to avoid adding strain on the animals. Late-gestation heat stress impairs productivity in the dam and exerts transgenerational effects on progeny. Physiological responses are complex and detriments to performance are multifaceted. Late-gestation heat stress blunts mammary gland involution in the first half of the dry period and impairs cell proliferation as calving approaches. Moreover, cows that were exposed to prepartum heat-stress exhibit reduced adipose tissue mobilization and a lower degree of insulin resistance during early lactation. Prepartum heat exposure also depresses immune function and evidence links this decrease to altered prolactin signaling under heat stress. Placental functions are also impaired as reflected in a higher cotyledon mass but lower maternal circulating estrone sulfate concentrations, potentially resulting in lower nutrient supply and reduced calf birth weight. In addition, calves born to heat-stressed dams show impaired immune function and therefore higher disease susceptibly. Novel evidence reported that intrauterine heat stress alters the methylation profile of liver and mammary DNA, which may also contribute to the poorer performance during adulthood of calves exposed to heat stress in utero. Understanding the contribution of all altered biological systems during late-gestation heat stress can be used as a basis for improving cow management during the dry period. This article provides a review of the impacts of late-gestation heat stress and of the emerging understanding of the biological mechanisms that underlie the observed impairments of performance.

Abstract OT1-04-03: Alternative dosing of exemestane before surgery in postmenopausal patients with stage 0-II estrogen receptor positive breast cancer: Design and methodology

Abstract Background: The aromatase inhibitor exemestane (EXE) has shown to lower cancer incidence in high-risk postmenopausal women. However, undesirable symptoms and side effects (i.e., bone density loss, musculoskeletal ache, climacteric syndrome) may compromise patient motivation and adherence to a long-term preventive treatment. A less frequent drug schedule, compared to the standard regimen, may be more acceptable to healthy at-risk women. We hypothesized that comparison of two alternative less frequent dose regimens with the standard daily dose regimen will show that it is possible to decrease undesirable symptoms of EXE while still effectively reducing serum estradiol. Trial Design: We are conducting a multi-center, pre-surgical, double-blind, non-inferiority phase IIb study in which 180 postmenopausal women will be randomized to receive either EXE 25 mg/day or 25 mg/three times a week or 25 mg/week for 4 to 6 weeks prior to surgery. Surgery will occur on day 29, 36 or 43 after treatment initiation. Eligible subjects are postmenopausal women with histologically-confirmed ER-positive (ER &amp;gt;10%) primary breast cancer candidates for surgery. Participants with T0-2, N0-1, Mx or with larger tumors who refuse neo-adjuvant therapy before surgery are eligible. Subjects are stratified according to participating site and body mass index (&amp;lt;25 kg/m2 versus &amp;gt;25 kg/m2). The primary objective is to assess if the reduction in estradiol with EXE 25 mg/three times a week and EXE 25 mg/week is comparable with the standard dose of 25 mg/day of EXE. Methods: Blood will be collected at baseline and at the end of treatment. Tissue samples will be collected from the diagnostic biopsy and at the time of surgery. The primary endpoint is the percentage change of serum estradiol concentration between baseline and surgery in the three arms in a CLIA certified laboratory. Given the expected reduction of at least 80% change with EXE at 25 mg daily considered as reference group (control arm) against 25 mg/three times a week or 25 mg weekly, for the power calculation we assume a non-inferiority difference of 6% in percentage changes of circulating estradiol after treatment from baseline, using a one-sided, two-sample t-test. Secondary outcome measures are the incidence of toxicity and menopausal symptoms according to the CTCAE (v4) and by the self-administered MENQoL; the effect of the three regimens on sex hormones (estrone, estrone sulphate, SHBG, testosterone, DHEAS and FSH) and the effect on circulating estradiol levels using an ultrasensitive method given that the serum levels in postmenopausal women under EXE may be very low. Drug and metabolites levels will be measured in blood, cancer tissue and non-cancer tissue. Evaluation of serum insulin, glucose (homeostatic model assessment index), and lipid profile (total cholesterol, high-density lipoprotein cholesterol and triglycerides), leptin and adiponectin will be performed before and after treatment. Additionally, we will measure breast estradiol concentration in cancer and non-cancer tissue and compare changes in ER, PgR, and proliferation in cancer and non-cancer tissue samples obtained at time of biopsy and definitive surgery. Finally, we will also analyze the role of the polymorphic UGT2B17 gene (involved in EXE and 17-dihydroexemestane metabolism) as well as tissue proteomics. Preliminary results: Enrollment started in February 2017 and as of July 3, 2019, a total of 170/180 participants have been randomized (94% of the expected sample size). Preliminary data will be presented at the conference. IND Sponsor: NCI/DCP NCI contract: HHSN26120120034I Citation Format: Aliana Guerrieri-Gonzaga, Parjhitham Thomas, Andrea DeCensi, Katherine D Crew, Nagi Kumar, Sara Gandini, Lana Vornik, Brandy Heckman-Stoddard, Eva Szabo, Eileen Dimond, Jack Lee, Diane Liu, Matteo Lazzeroni, Sara Cagnacci, Davide Serrano, Mauro D'Amico, Flavio Guasone, Tania Buttiron Webber, Powel Brown, Bernardo Bonanni. Alternative dosing of exemestane before surgery in postmenopausal patients with stage 0-II estrogen receptor positive breast cancer: Design and methodology [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT1-04-03.

Abstract P5-12-01: SOLE (study of letrozole extension), a phase 3 randomized clinical trial of continuous vs intermittent letrozole in postmenopausal women who have received 4-6 years of adjuvant endocrine therapy for lymph node-positive, early breast cancer (BC): Final analysis and sole estrogen substudy (SOLE-EST)

Abstract Background: In animal models of hormone receptor positive (HR+) breast cancer, acquired resistance to continued letrozole was shown to be reversed by estrogen-induced apoptosis. We hypothesized that the rise in estrogen levels during short treatment interruptions would resensitize breast cancer cells to letrozole and improve treatment outcome. SOLE tested the hypothesis that 3 mos treatment-free intervals during extended adjuvant therapy will improve disease-free survival (DFS). We previously reported the primary endpoint after 60 mos median follow-up: extended intermittent letrozole did not improve DFS vs extended continuous letrozole. However, only 9% of pts had breast cancer events, justifying updating the analysis with longer follow-up. The dynamic of recovery of estrogen levels after stopping letrozole therapy has not been previously reported. Methods: SOLE enrolled 4884 postmenopausal women with HR+ lymph node-positive BC who had completed 4-6 yrs of adjuvant endocrine therapy (19% SERM, 43% AI, 38% both; stratification factor). Pts were randomized to an additional 5 yrs continuous letrozole (2.5 mg daily; n=2441) vs 5 yrs intermittent letrozole (taken for the first 9 mos of yrs 1-4, and 12 mos in yr 5; n=2443). We report the final analysis of the SOLE trial after 84 mos median follow-up. In SOLE-EST, levels of estradiol (E2), estrone (E1) and estrone sulphate (E1S) at 0, 9, 10.5 and 12 mos after randomization were determined using a highly sensitive assay in a subgroup of 90 evaluable patients (21 in the continuous and 69 in the intermittent group). Results: There were 923 DFS events. 7 yr DFS was 81.5% in both groups. More pts had distant metastases in the continuous group (8.7% vs 7.5%) while second (non-breast) malignancies were more frequent in the intermittent group (5.5% vs 4.7%). Similar outcomes were observed for breast cancer-free interval (BCFI) (88.6% vs 88.0%), distant recurrence-free interval (DRFI) (91.6% vs 90.4%), and overall survival (OS) (90.6% vs 89.6%) for pts assigned intermittent vs continuous letrozole. In the intermittent group, median E2, E1 and E1S levels more than doubled compared with levels at 9 mos after randomization in the first 6 weeks after stopping letrozole during the treatment free interval while levels were stable for the 21 pts tested in the continuous group. Conclusions: Among postmenopausal women with HR+ BC, extended intermittent letrozole did not improve DFS vs continuous letrozole. Similar outcome was consistently observed for BCFI, DRFI and OS. The SOLE-EST substudy indicates an important increase in estrogen levels as soon as 6 weeks after stopping letrozole therapy in the intermittent group. Further investigation of prior exposure to aromatase inhibitors in relation with outcome and with E2, E1 and E1S levels in SOLE-EST are underway. Citation Format: Guy Jerusalem, Subrina Farah, Jacquie Chirgwin, Stefan Aebi, Per Karlsson, Patrick Neven, Erika Hitre, Marie-Pascale Graas, Edda Simoncini, Claus Kamby, Alastair Thompson, Sibylle Loibl, Joaquín Gavilá, Katsumasa Kuroi, Christian Marth, Bettina Müller, Seamus O'Reilly, Andrea Gombos, Thomas Ruhstaller, Harold Burstein, Manuela Rabaglio, Barbara Ruepp, Giuseppe Viale, Richard D Gelber, Alan S Coates, Angelo Di Leo, Aron Goldhirsch, Meredith Regan, Marco Colleoni. SOLE (study of letrozole extension), a phase 3 randomized clinical trial of continuous vs intermittent letrozole in postmenopausal women who have received 4-6 years of adjuvant endocrine therapy for lymph node-positive, early breast cancer (BC): Final analysis and sole estrogen substudy (SOLE-EST) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-12-01.

Pregnancy-associated glycoproteins as a potential marker for diagnosis of early pregnancy in goats: A scoping reviewing

Early diagnosis of pregnancy plays an important role to minimize reproductive losses in farm animals. There are several methods for pregnancy diagnosis like profiling of reproductive hormones (such as progesterone and estrone sulfate), but sometimes they provide false-positive results. Embryo specific pregnancy markers, which delineate the presence and viability of the embryo, are considered as perfect for pregnancy determination. Pregnancy-associated glycoproteins are distinguished as the best indicator for the determination of early pregnancy, fetal number, and birth weight of kids. Pregnancy-associated glycoproteins are structurally correlated to aspartic proteinase and are communicated in the external epithelial cell layer of the placenta. They have been found to share about half amino acid sequence identity with pepsinogen, pepsin, cathepsin D and E. Dislike different individuals from aspartic proteinase family, numerous pregnancy-associated glycoproteins appear to be latent compound as a result of amino acid substitutions in and around the catalytic site. This review is to discuss the scope and prospects of pregnancy-associated glycoproteins as a pregnancy marker in farm animals, more specifically in goats.