Haplosufficient genomic androgen receptor signaling is adequate to protect female mice from induction of polycystic ovary syndrome features by prenatal hyperandrogenization

Polycystic ovary syndrome (PCOS) is associated with reproductive, endocrine, and metabolic abnormalities. Because hyperandrogenism is the most consistent PCOS feature, we used wild-type (WT) and androgen receptor (AR) knockout (ARKO) mice, together with a mouse model of PCOS, to investigate the contribution of genomic AR-mediated actions in the development of PCOS traits. PCOS features were induced by prenatal exposure to dihydrotestosterone (250 μg) or oil vehicle (control) on days 16-18 of gestation in WT, heterozygote, and homozygote ARKO mice. DHT treatment of WT mice induced ovarian cysts (100% vs 0%), disrupted estrous cycles (42% vs 100% cycling), and led to fewer corpora lutea (5.0±0.4 vs 9.8±1.8). However, diestrus serum LH and FSH, and estradiol-induced-negative feedback as well as hypothalamic expression of kisspeptin, neurokinin B, and dynorphin, were unaffected by DHT treatment in WT mice. DHT-treated WT mice exhibited a more than 48% increase in adipocyte area but without changes in body fat. In contrast, heterozygous and homozygous ARKO mice exposed to DHT maintained comparable ovarian (histo)morphology, estrous cycling, and corpora lutea numbers, without any increase in adipocyte size. These findings provide strong evidence that genomic AR signaling is an important mediator in the development of these PCOS traits with a dose dependency that allows even AR haplosufficiency to prevent induction by prenatal androgenization of PCOS features in adult life.

Potential role of the gaseous mediator hydrogen sulphide (H2S) in inhibition of human colonic contractility

BACKGROUND

Hydrogen sulphide (H2S) is an endogenous signalling molecule that might play a physiologically relevant role in gastrointestinal motility. Cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) are two enzymes responsible for H2S production. d,l-Propargylglycine (PAG) is a CSE inhibitor whereas both aminooxyacetic acid (AOAA) and hydroxylamine (HA) are CBS inhibitors. The characterization of H2S responses and its mechanism of action are crucial to define H2S function.

METHODS

Human colonic strips were used to investigate the role of H2S on contractility (muscle bath) and smooth muscle electrophysiology (microelectrodes). NaHS was used as a H2S donor.

RESULTS

Combination of PAG and AOAA depolarized the smooth muscle (5-6mV, n=4) and elicited a transient increase in tone (260.5±92.8mg, n=12). No effect was observed on neural mediated inhibitory junction potential or relaxation. In the presence of tetrodotoxin 1μM, NaHS concentration-dependently inhibited spontaneous contractions (EC50=329.2μM, n=18). This effect was partially reduced by the guanylyl cyclase inhibitor ODQ 10μM (EC50=2.6μM, n=12) and by l-NNA 1mM (EC50=1.4mM, n=8). NaHS reversibly blocked neural mediated cholinergic (EC50=2mM) and tachykinergic (EC50=5.7mM) contractions. NaHS concentration-dependently reduced the increase in spontaneous mechanical activity (AUC) induced by carbachol (EC50=1.9mM) and NKA (EC50=1.7mM AUC).

CONCLUSIONS

H2S might be an endogenous gasomediator regulating human colonic contractility. Its inhibitory effect is observed at high concentrations and could be mediated by a direct effect on smooth muscle with a possible synergistic effect with NO, as well as by an interaction with the cholinergic and tachykinergic neural mediated pathways.

Deterministic lateral displacement for particle separation: a review

Deterministic lateral displacement (DLD), a hydrodynamic, microfluidic technology, was first reported by Huang et al. in 2004 to separate particles on the basis of size in continuous flow with a resolution of down to 10 nm. For 10 years, DLD has been extensively studied, employed and modified by researchers in terms of theory, design, microfabrication and application to develop newer, faster and more efficient tools for separation of millimetre, micrometre and even sub-micrometre sized particles. To extend the range of potential applications, the specific arrangement of geometric features in DLD has also been adapted and/or coupled with external forces (e.g. acoustic, electric, gravitational) to separate particles on the basis of other properties than size such as the shape, deformability and dielectric properties of particles. Furthermore, investigations into DLD performance where inertial and non-Newtonian effects are present have been conducted. However, the evolvement and application of DLD has not yet been reviewed. In this paper, we collate many interesting publications to provide a comprehensive review of the development and diversity of this technology but also provide scope for future direction and detail the fundamentals for those wishing to design such devices for the first time.

Interplay between myogenic pacemakers and enteric neurons determine distinct motor patterns in the rat colon

Waxing and waning of slow waves amplitude has been recently associated with a segmentation motor pattern in the murine small intestine. The 'wax and wane' phenomenon in this area of the gastrointestinal tract seems to be the result of modulation of slow waves by a second pacemaker of a lower frequency displayed by the interstitial cells of Cajal near the deep muscular plexus (ICC-DMP). In the rat colon, smooth muscle cyclic depolarizations causing low-frequency (LF) contractions (0.9 ± 0.1 cpm) occur together with slow wave activity associated to high-frequency (HF) contractions (14 ± 0.3 cpm; ripples). In the present manuscript, we demonstrate the presence of 'wax and wane' in rat colonic slow waves. Depolarization from the 'wax' to the 'wane' was 7.6 ± 1.2 mV, i.e., smooth muscle cells went from a resting membrane potential (RMP) of -50.0 mV to a RMP of -42.4 mV. The amplitude of the slow wave decreased from 14.0 ± 2.2 mV to 3.4 ± 0.7 mV. The wax and wane phenomenon occurred at 0.9 ± 0.1 cpm, coinciding with the frequency of cyclic depolarizations. Therefore, we hypothesized that the 'wax and wane' of slow waves in the rat colon could be the result of their interaction with the LF pacemaker. We describe three different myogenic motor patterns that depend on the level of smooth muscle and ICC excitation: (i) LF propulsive contractions, (ii) regular slow waves causing ripples, and (iii) a wax and wane pattern that may lead to segmentation. Different intra- and extra-luminal inputs probably determine the dominating motor pattern in each area through the enteric nervous system.

Cysteine-grafted nonwoven geotextile: a new and efficient material for heavy metals sorption--Part B

The development of a new material designed to trap heavy metals from sediments or wastewater, based on a polypropylene non-woven covalently grafted with cysteine, has been reported in a previous paper (Part A). The non-woven was first functionalized with acrylic acid (AA) which is used as spacer, and then cysteine was immobilized on the substrate through covalent coupling in order to obtain the so-called PP-g-AA-cysteine. Some preliminary heavy metals adsorption tests gave interesting results: at 20 °C for 24 h and in a 1000 mg/L heavy metals solution, PP-g-AA-cysteine adsorbs 95 mg Cu/g PP (CuSO4 solution), 104 mg Cu/g PP (Cu(NO3)2 solution), 135 mg Pb/g PP (Pb(NO3)2 solution) and 21 mg Cr/g PP (Cr(NO3)3 solution). In this second part of the work, heavy metals sorption tests were carried out with Cu (II), Pb (II), and Cr (III) separately, in order to determine the sorption capacity of this new sorbent as a function of (i) the heavy metals concentration in the solution, (ii) the contact time with the solution, (iii) the pH and (iv) the ionic strength of the solution containing heavy metals. Moreover, the sorption capacity of PP-g-AA-Cysteine was studied using a polluted solution consisting of a mixture of these different heavy metals. An Electron Paramagnetic Resonance study was finally carried out in order to determine the coordination geometry in the environment of the copper trapped by the PP-g-AA-cysteine.

Effects of hydrogen sulphide on motility patterns in the rat colon

BACKGROUND AND PURPOSE

Hydrogen sulphide (H2 S) is an endogenous gaseous signalling molecule with putative functions in gastrointestinal motility regulation. Characterization of H2 S effects on colonic motility is crucial to establish its potential use as therapeutic agent in the treatment of colonic disorders.

EXPERIMENTAL APPROACH

H2 S effects on colonic motility were characterized using video recordings and construction of spatio-temporal maps. Microelectrode and muscle bath studies were performed to investigate the mechanisms underlying H2 S effects. NaHS was used as the source of H2 S.

KEY RESULTS

Rhythmic propulsive motor complexes (RPMCs) and ripples were observed in colonic spatio-temporal maps. Serosal addition of NaHS concentration-dependently inhibited RPMCs. In contrast, NaHS increased amplitude of the ripples without changing their frequency. Therefore, ripples became the predominant motor pattern. Neuronal blockade with lidocaine inhibited RPMCs, which were restored after administration of carbachol. Subsequent addition of NaHS inhibited RPMCs. Luminal addition of NaHS did not modify motility patterns. NaHS inhibited cholinergic excitatory junction potentials, carbachol-induced contractions and hyperpolarized smooth muscle cells, but did not modify slow wave activity.

CONCLUSIONS AND IMPLICATIONS

H2 S modulated colonic motility inhibiting propulsive contractile activity and enhancing the amplitude of ripples, promoting mixing. Muscle hyperpolarization and inhibition of neurally mediated cholinergic responses contributed to the inhibitory effect on propulsive activity. H2 S effects were not related to changes in the frequency of slow wave activity originating in the network of interstitial cells of Cajal located near the submuscular plexus. Luminal H2 S did not modify colonic motility probably because of epithelial detoxification.

Characterization of reproductive, metabolic, and endocrine features of polycystic ovary syndrome in female hyperandrogenic mouse models

Polycystic ovary syndrome (PCOS) affects 5-10% of women of reproductive age, causing a range of reproductive, metabolic and endocrine defects including anovulation, infertility, hyperandrogenism, obesity, hyperinsulinism, and an increased risk of type 2 diabetes and cardiovascular disease. Hyperandrogenism is the most consistent feature of PCOS, but its etiology remains unknown, and ethical and logistic constraints limit definitive experimentation in humans to determine mechanisms involved. In this study, we provide the first comprehensive characterization of reproductive, endocrine, and metabolic PCOS traits in 4 distinct murine models of hyperandrogenism, comprising prenatal dihydrotestosterone (DHT, potent nonaromatizable androgen) treatment during days 16-18 of gestation, or long-term treatment (90 days from 21 days of age) with DHT, dehydroepiandrosterone (DHEA), or letrozole (aromatase inhibitor). Prenatal DHT-treated mature mice exhibited irregular estrous cycles, oligo-ovulation, reduced preantral follicle health, hepatic steatosis, and adipocyte hypertrophy, but lacked overall changes in body-fat composition. Long-term DHT treatment induced polycystic ovaries displaying unhealthy antral follicles (degenerate oocyte and/or > 10% pyknotic granulosa cells), as well as anovulation and acyclicity in mature (16-week-old) females. Long-term DHT also increased body and fat pad weights and induced adipocyte hypertrophy and hypercholesterolemia. Long-term letrozole-treated mice exhibited absent or irregular cycles, oligo-ovulation, polycystic ovaries containing hemorrhagic cysts atypical of PCOS, and displayed no metabolic features of PCOS. Long-term dehydroepiandrosterone treatment produced no PCOS features in mature mice. Our findings reveal that long-term DHT treatment replicated a breadth of ovarian, endocrine, and metabolic features of human PCOS and provides the best mouse model for experimental studies of PCOS pathogenesis.

Nitrergic and purinergic mechanisms evoke inhibitory neuromuscular transmission in the human small intestine

BACKGROUND

Inhibitory neuromuscular transmission in the human colon is due to nitrergic and purinergic (P2Y1 -mediated) inputs. The aim of this study was to determine the mechanisms of neuromuscular transmission in different regions of the human small intestine.

METHODS

Ileal (n = 6) and jejunal (n = 6) samples underwent histological examination and were studied using sharp microelectrodes in smooth muscle cells and conventional muscle bath techniques. Electrical field stimulation (EFS) was used to stimulate inhibitory neurons.

KEY RESULTS

No histological abnormalities were found. Resting membrane potential was -39.7 ± 1.5 and -45.5 ± 2.1 mV in the jejunum and ileum, respectively. Slow waves and spontaneous contractions were recorded at a frequency of about 8-9 and 6-7 cpm in the jejunum and ileum, respectively. In non-adrenergic, non-cholinergic conditions, EFS caused an inhibitory junction potential and mechanical relaxation. Both responses were blocked by tissue incubation with the nitric oxide synthase inhibitor (Nω-nitro-l-arginine 1 mM) and the P2Y1 receptor blocker 2'-deoxy-N(6) -methyladenosine 3',5'-bisphosphate tetrasodium salt (MRS2179; 10 μM). Both exogenous addition of sodium nitroprusside (1 μM) and the preferential P2Y1 receptor agonist ADPβS (1 μM) hyperpolarized and relaxed smooth muscle cells. MRS2179 (10 μM) blocked ADPβS-induced responses.

CONCLUSIONS & INFERENCES

Similar to colon, inhibitory neurotransmission in the human small intestine is mainly mediated by purinergic (via P2Y1 receptors) and nitrergic inhibitory neurotransmission. Similar mechanisms of inhibitory neurotransmission are present in different regions of the human intestine.

A French collaborative survey of 272 fetuses with 22q11.2 deletion: ultrasound findings, fetal autopsies and pregnancy outcomes

OBJECTIVE

The 22q11.2 deletion (del22q11.2) is one of the most common microdeletions. We performed a collaborative, retrospective analysis in France of prenatal diagnoses and outcomes of fetuses carrying the del22q11.2.

METHODS

A total of 272 fetuses were included. Data on prenatal diagnosis, ultrasound findings, pathological features, outcomes and inheritance were analyzed.

RESULTS

The mean time of prenatal diagnosis was 25.6 ± 6 weeks of gestation. Most of the diagnoses (86.8%) were prompted by abnormal ultrasound findings [heart defects (HDs), in 83.8% of cases]. On fetal autopsy, HDs were again the most common disease feature, but thymus, kidney abnormalities and facial dysmorphism were also described. The deletion was inherited in 27% of cases. Termination of pregnancy (TOP) occurred in 68.9% of cases and did not appear to depend on the inheritance status. However, early diagnosis was associated with a higher TOP rate.

CONCLUSION

This is the largest cohort of prenatal del22q11.2 diagnoses. As in postnatally diagnosed cases, HDs were the most frequently observed abnormalities. However, thymus and kidney abnormalities and polyhydramnios should also be screened for in the prenatal diagnosis of del22q11.2. Only the time of diagnosis appeared to be strongly associated with the pregnancy outcome: the earlier the diagnosis, the higher the TOP rate.

Cysteine-grafted nonwoven geotextile: a new and efficient material for heavy metals sorption--part A

Cysteine is an interesting biomolecule in the heavy metals trapping field, thanks to its amino, thiol and carboxylic groups. This amino acid is indeed present in some natural chelating agents: glutathione, phytochelatins and metallothioneins. However, cysteine has never been used in remediation processes. When immobilized on a polypropylene nonwoven (PP) geotextile, an innovative and eco-friendly material is obtained, with potential use in drainage and filtration of wastewaters and sediments. PP was first functionalized with acrylic acid using a low pressure cold plasma process to bring reactive carboxylic functions onto the surface (PP-g-AA). Cysteine was then covalently grafted on this modified PP. The cysteine grafting on PP-g-AA was optimized using response surface methodology, which allowed concluding that the best conditions of immersion without heating consist in: a solution containing 0.229 mol/L of cysteine for 28 h. The materials were characterized by Scanning Electron Microscopy, InfraRed Spectroscopy and X-ray Photoelectron Spectroscopy: evidence of covalent cysteine grafting was given. Preliminary sorption tests at 20 °C and pH = 4.5 with artificially polluted solutions give promising results for divalent heavy metal ions: 95 mg Cu (II) (CuSO4 solution), 104 mg Cu (II) and 135 mg Pb(II) (with NO3(-) counter-ion) per gram of PP are trapped.

Mechanistic investigation of a flame retardant coating made by layer-by-layer assembly

A flame retardant coating based on poly(allylamine) (PAH) and montmorillonite (MMT), deposited on polyamide 6 (PA6) sheets, is investigated. PA6-(PAH-MMT) at 40 bilayers was tested in a cone calorimeter and interrupted at different characteristic times. A possible mechanism of action of PA6 in the presence of layer-by-layer coating is proposed.

Abstract P1-08-27: Quantitative analysis of tumor expression of phosphoproteins from PI3-kinase and MAP-kinase signaling pathways as biomarkers of the biological and clinical activity of trastuzumab and everolimus in breast cancer: Unicancer RADHER phase II trial results

Background: PI3-kinase (PI3K) and MAP kinase (MAPK) are the main signaling pathways implicated in molecular oncogenesis. In breast cancer, inhibition of these signaling pathways has been largely envisaged by means of targeted therapy. Unicancer RADHER study aimed at evaluating the efficacy of adding everolimus (E) to trastuzumab (T) as preoperative therapy for primary HER2+ operable breast cancer patients and to evaluate molecular response biomarkers. We report here the investigation of the expression of phosphoproteins from PI3K and MAPK signaling pathways as predictive biomarkers of clinical and pathological response as well as pharmacodynamic markers of treatment activity.

Methods: 82 eligible patients were randomized to receive T alone (loading dose 4 mg/kg, then 2 mg/kg/week), or T+E (10 mg/day) for a 6-week pre-operative treatment. Clinical response rate (cRR) was determined from OMS criteria with complete and partial responses being considered as “ responders “ and stable and progressive diseases as “ non responders “. Pathological response rate was evaluated according to Sataloff classification, with Ta and Tb being considered as “ responders “ and, Tc and Td as “ non responders “. The expression levels of phosphorylated-AKT (p-AKT), p-GSK3b, p-S6 kinase, p-MEK1, p-ERK1/2, p-P90RSK, p-IGF1R as well as p-P38MAPK were quantitatively assessed using multiplex bead immuno-assay. All patients had baseline needle frozen biopsies taken before initiation of the treatment, at cycle 4 as an option and at surgery. Before being submitted to total protein extraction, all biopsies were validated by a senior pathologist after HE slide examination to ensure a tumor content >50%. 36 pairs associating baseline + surgery tumor specimens and 4 pairs of baseline + cycle 4 biopsies were eligible for protein extraction. Results: No statistically significant relationship was observed between the expression level of any of the phosphoproteins in the initial biopsies and neither the clinical nor the pathological response, overall. After treatment, as compared to the level of expression measured in the initial biopsies, a significant increase of p-GSK3β, p-MEK1, p-ERK1/2, p-P38MAPK was observed in T+E arm and a significant decrease in p-S6 kinase expression in the global patient population. No significant variation was observed in T arm. Additional analysis with immunohistochemistry data is planned and will be presented.

Conclusion: In the present study, measuring phosphoproteins expression showed that combining E with T, altered the regulation of signaling proteins from PI3-Kinase and MAP-kinase pathways. No response predictive biomarker could be identified among the phosphoproteins analyzed tending to show that the clinical and pathological response to T and T+E should be driven by additional mechanisms. As a whole, these results validate the use of multiplex bead immuno-analysis for determination of phosphorylated signaling proteins in clinical needle biopsies from breast cancer specimens and its prospective evaluation as biomarker for the activity of targeted therapies.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-08-27.

Abstract S6-07: Genomic characterisation of metastatic samples from breast cancer patients using next generation sequencing

Background: Although several studies have reported genomic characterisation of primary breast tumors, little is known about the genomic alterations of the metastatic tissues. Breast cancer patients who were prospectively enrolled in a trial (SAFIR01) underwent a biopsy of metastasis. The primary aim of this biopsy was to drive the treatment according to the results of whole genome CGH arrays and sanger sequencing on two genes (PIK3CA and AKT1). The results of the clinical trial were previously reported (André et al ASCO 2013). The secondary goal of the biopsies was to perform genomic characterisation of metastases in breast cancer patients. Here we report the analyses of such metastatic samples using next generation sequencing (NGS) approaches.

Patients and methods: Two approaches were applied. In order to describe the incidence of targetable genomic alterations, we performed in depth targeted sequencing on 100 genes (200x coverage) using Illumina HiSeq 2000 (DNA vision). This analysis was performed on 240 metastatic samples. The second approach was more exploratory and aimed at discovering new genes involved in the metastatic process and/or resistance to therapies. In order to achieve this goal, we performed whole exome sequencing in 100 pairs of metastatic tissue (100x) and normal DNA (Integragen Inc, Hiseq platform). Finally, phosphor-S6K staining was performed in 300 samples in order to explore the activation status of mTOR pathway in metastatic disease, and to correlate with genomic data.

Results: Targeted sequencing was performed on 240 metastatic samples in order to report the prevalence of targetable genomic alterations in metastatic breast cancer. Results are available for the first 159 samples. In addition to the already reported PIK3CA (26%) and AKT1 mutations (4%), NGS identified mutations of PTEN (4%), ERBB2 (2%), K-Ras (1%), ATM (2%), CDH1 (2%), GATA3 (2%), PTPN11 (1%), PTPRD (1%), ROS1 (1%). Results on the 81 samples, together with whole exome sequencing (n = 100) and phosphoproteins are being analysed and results will be available mid-november 2013.

Conclusion: This is the first large study that aims at defining the genomic landscape of metastatic samples. Results will provide insights into the prevalence of targetable genomic alterations in metastatic tissue, together with candidate genes involved in the metastatic process and resistance to therapies.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr S6-07.