Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
  • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
  • G01N33/92—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving lipids, e.g. cholesterol, lipoproteins, or their receptors
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/42—Gynaecological or obstetrical instruments or methods
  • A61B17/425—Gynaecological or obstetrical instruments or methods for reproduction or fertilisation
  • A61B17/435—Gynaecological or obstetrical instruments or methods for reproduction or fertilisation for embryo or ova transplantation
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
  • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
  • G01N33/5005—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving human or animal cells
  • G01N33/5008—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving human or animal cells for testing or evaluating the effect of chemical or biological compounds, e.g. drugs, cosmetics
  • G01N33/502—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving human or animal cells for testing or evaluating the effect of chemical or biological compounds, e.g. drugs, cosmetics for testing non-proliferative effects
  • G01N33/5023—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving human or animal cells for testing or evaluating the effect of chemical or biological compounds, e.g. drugs, cosmetics for testing non-proliferative effects on expression patterns
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
  • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
  • G01N33/88—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving prostaglandins or their receptors
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2500/00—Screening for compounds of potential therapeutic value
  • G01N2500/10—Screening for compounds of potential therapeutic value involving cells
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2800/00—Detection or diagnosis of diseases
  • G01N2800/36—Gynecology or obstetrics
  • G01N2800/367—Infertility, e.g. sperm disorder, ovulatory dysfunction
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T436/00—Chemistry: analytical and immunological testing
  • Y10T436/10—Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing
  • Y10T436/104165—Lipid, cholesterol, or triglyceride standard or control

Definitions

• the invention relates to a non-invasive method for the detection of endometrial receptivity to embryo implantation.
• the method is especially applicable for determining status fertility of a mammalian female, preferably, a woman.
• the invention further relates to a kit for performing said method.
• IVF generally is a multistep process that involves recovering mature eggs from the female patient or donor; incubation of eggs in artificial culture media; collection of sperm from the patient or donor and subsequent preparation; fertilization of the egg by the sperm; monitoring and selection of good-quality embryos; and transfer of these to the uterine cavity.
• the embryo must implant onto the receptive endometrium so that pregnancy can progress. It is well established that this particular step is responsible for a significant percentage of the failures, and, therefore, it is clinically relevant to look at possible causes and solutions of the problem.
• Implantation of the transferred embryo involves a synchronized crosstalk between a receptive endometrium and a functional blastocyst [Wang, H., and Dey, SK. 2006. Roadmap to embryo implantation: clues from mouse models. Nature Review Genetics. 7: 185-199].
• This phenomenon can only take place during the window of implantation, a self-limited period of endometrial receptivity spanning between days 19 and 23 of the menstrual cycle (women). In normal menstrual cycles this is achieved through the local effects of ovarian estrogens and progesterone, which induce a series of cellular and molecular events in the endometrium leading to appropriate endometrial receptivity.
• Metabolomics is a discipline dedicated to the systematic study of small molecules (i.e., metabolites) in cells, tissues, and biofluids. Metabolites are the end products of cellular regulatory processes, and their levels can be regarded as the amplified response of biological systems to genetic or environmental changes. Clinicians have relied for decades on a small part of the information contained in the metabolome, for example measuring glucose to monitor diabetes and measuring cholesterol for cardiovascular health. New sophisticated metabolomic analytical platforms and informatic tools have already been developed that afford extended and sensitive measurement of the metabolome.
• Lipids are known to play an important role as structural components (e.g., cell membranes), energy storage components, and as signalling molecules. Lipids are broadly defined as hydrophobic or amphipathic small molecules that may originate entirely or in part by carbanion based condensation of thioesters, and/or by carbocation based condensation of isoprene units. "Lipidomics" can be considered as a sub-field of metabolomics which aims to elucidate the biological processes in the context of lipids by measuring and characterizing the extended lipid profiles at the molecular level (lipidomic profiles). Traditional clinical lipid measures quantify total amounts of triglycerides, cholesterol, or lipoproteins. However, serum lipid profile is more complex at the molecular level.
• the invention is based on the discovery that, surprisingly, the level of a prostaglandin selected from the group consisting of prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2a), and combinations thereof, in a sample of endometrial fluid from a woman is correlated with endometrial receptivity to embryo implantation.
• PGE2 prostaglandin E2
• PGF2a prostaglandin F2 alpha
• the invention relates to the use of a prostaglandin selected from the group consisting of prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2a), and combinations thereof, when said prostaglandin is determined in an endometrial fluid sample, as a biomarker of endometrial receptivity for implanting an embryo.
• a prostaglandin selected from the group consisting of prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2a), and combinations thereof, when said prostaglandin is determined in an endometrial fluid sample, as a biomarker of endometrial receptivity for implanting an embryo.
• the invention relates to a method for detecting endometrial receptivity to embryo implantation in a mammalian female, said method comprising the steps of:
• PGE2 prostaglandin E2
• PEF2a prostaglandin F2 alpha
• the invention relates to a method for selecting the implantation window of an embryo in a mammalian female, which comprises determining the level of PGE2 and/or the level of PGF2a, in a sample of endometrial fluid from said mammalian female, wherein said implantation window is selected when the level of at least one of said prostaglandins PGE2 or PGF2a in said sample is increased in relation to a reference sample.
• the invention relates to a method for assessing the fertility status of a mammalian female based on the level of PGE2 and/or PGF2a in a sample of endometrial fluid from said mammalian female, and its correlation with the fertility status of said mammalian female.
• the invention relates to a method for assessing if a mammalian female is under conditions suitable for receiving and implanting an embryo, based on the level of PGE2 and/or PGF2a in a sample of endometrial fluid from said mammalian female, and its correlation with the conditions for receiving and implanting an embryo.
• said mammalian female is a woman subjected to an in vitro fertilization (IVF) process.
• the invention relates to a method for monitoring endometrial maturation in a mammalian female based on the level of PGE2 and/or PGF2a in a sample of endometrial fluid from said mammalian female, and its correlation with endometrial maturation.
• the invention relates to a method of in vitro fertilization in a mammalian female based on the level of PGE2 and/or PGF2a in a sample of endometrial fluid from said mammalian female, and its correlation with endometrial maturation, wherein an embryo is introduced into the uterus of said mammalian female when said endometrium is mature.
• the invention relates to a kit comprising a reference lipid for PGE2 and/or for PGF2a.
• a kit comprising a reference lipid for PGE2 and/or for PGF2a.
• the invention relates to a method for identifying a compound capable of enhancing endometrium receptivity.
• the invention relates to a method for identifying a contraceptive agent.
• the invention relates to a lipid composition, wherein said lipid composition is obtained from an endometrial fluid sample from a mammalian female during the implantation window of an embryo in said mammalian female.
• said lipid composition for determining endometrial receptivity to embryo implantation in a mammalian female constitutes a further aspect of this invention.
• the invention relates to a method for selecting the implantation window of an embryo in a mammalian female comprising the steps:
• Figure 1 shows the levels of different lipids from endometrial fluid samples from women, during their natural menstrual cycle; the lipids were identified by liquid chromatography combined with tandem mass-spectrometry [A: N-arachidonoyl ethanolamine (AEA); B: N-palmitoyl ethanolamine (PEA); C: N-oleoyl ethanolamine (OEA); D: 2-arachidonoyl glycerol (2- AG); E: N-stearoyl ethanolamine (SEA); F: N- linoleoyl ethanolamine (LEA); G: prostaglandin E2 (PGE2); H: prostaglandin F2 alpha (PGF2a); I: prostaglandin Fl alpha (PGFla)].
• AEA N-arachidonoyl ethanolamine
• PEA N-palmitoyl ethanolamine
• EOA N-oleoyl ethanolamine
• D 2-arachidonoyl glycerol (2- AG
• Figure 2 shows the levels of prostaglandin E2 (PGE2) and prostaglandin F2 alpha (PGF2a) in endometrial-fluid samples from women obtained throughout the menstrual cycle [Group I (days 0-8); Group II (days 9-14); Group III (days 15-18); Group IV (days 19-23) and Group V (days 24-30)].
• PGE2 prostaglandin E2
• PPF2a prostaglandin F2 alpha
• An objective of the present invention is to provide a specific and reliable biomarker for the detection of endometrial receptivity for implanting an embryo in a woman.
• the biomarker can be used, for example, for detecting endometrial receptivity to embryo implantation in a mammalian female, or for selecting the implantation window of an embryo in a mammalian female, or for assessing the fertility status of a mammalian female, or for assessing if a mammalian female is under conditions suitable for receiving and implanting an embryo, or for monitoring endometrial maturation in a mammalian female, or in a method of in vitro fertilization in a mammalian female.
• said mammalian female is a woman.
• said woman is a woman subjected to an in vitro fertilization (IVF) process.
• the inventors have now surprisingly found that some lipid compounds can be used as biomarkers for endometrial receptivity for implanting an embryo.
• the inventors have analyzed the levels of some lipids in endometrial fluid samples between days 19 to 21 of the menstrual cycle of a woman, coincident with the implantation window.
• it is now possible to identify the implantation window in a mammalian female by determining the lipid profile in endometrial fluid samples along the menstrual cycle. The method is based on comparison of the established lipid profile from a mammalian female to reference lipidomic biomarkers.
• said mammalian female is a woman.
• the inventors have observed that the concentration of two specific lipids, namely prostaglandins PGE2 and PGF2a, is significantly increased in endometrial fluid samples between days 19 to 21 of the menstrual cycle of a woman, coincident with the implantation window.
• PGE2 and PGF2a are two specific lipids, namely prostaglandins PGE2 and PGF2a.
• PGE2 7-[3-hydroxy-2-(3-hydroxyoct-l-enyl)-5-oxo-cyclopentyl]hept-5-enoic acid, is a naturally occurring prostaglandin, also known in medicine as "dinoprostone”; it has important effects in labour (softens cervix and causes uterine contraction) and also stimulates osteoblast to release factors which stimulate bone resoption by osteoclasts).
• dinoprostone can be used as an abortifacient since it is a direct vasodilator, relaxing smooth muscles, and it inhibits the release of noradrenaline from sympathetic nerve terminals.
• PGF2a (Z)-7-[(lR,2R,3R,5S)-3,5-dihydroxy-2-[(E,3S)-3-hydroxyoct-l-enyl) cyclopentyl]hept-5-enoic acid, is also a naturally occurring prostaglandin, also known in medicine as "dinoprost"; it is used in medicine to induce labour and as an abortifacient.
• said prostaglandins PGE2 and/or PGF2a when determined in endometrial fluid samples, can be used as biomarkers of endometrial receptivity to embryo implantation in a mammalian female, preferably, a woman.
• the use of said prostaglandin(s) PGE2 and/or PGF2a, in particular, when said prostaglandin(s), are determined in an endometrial fluid sample from a mammalian female, preferably, a woman, as biomarker(s) of endometrial receptivity to embryo implantation in said mammalian female constitutes an aspect of this invention.
• a “biomarker”, as used herein, refers to any lipid, for example, a prostaglandin, such as PEG2 and PGF2a, whose level (concentration) in endometrial fluid is altered in relation to a physiological condition of interest.
• the invention is based on the discovery that the level of a prostaglandin selected from the group consisting of prostaglandin PGE2, PGF2a, and combinations thereof, in a sample of endometrial fluid from a mammalian female, e.g., a woman, can be used as a biomarker of endometrial receptivity to embryo implantation in a mammalian female, e.g., a woman.
• the term "endometrial fluid” refers to a secretion of the glandular epithelium which contains all the compounds secreted to the lumen of the uterus [Aplin JD et al. The Endometrium, 2nd. edn: INFORMA healtcare; 2008].
• the endometrium constitutes the surface tissue which lines the uterine wall (myometrium or middle layer of the uterine wall consisting of smooth muscle cells and supporting stromal and vascular tissue) of a mammalian female such as a woman or a human or non-human primate or, in other words, the inner membrane of the mammalian uterus.
• the endometrium is extremely sensitive to the hormones estrogen and progesterone and is composed of several functional layers.
• the tissue architecture of the endometrium comprises an external cell layer, which constitutes the epithelium, which is in direct contact with the lumen of the uterus, and an internal cell layer, denominated stroma, which constitutes around 80% of the endometrium thickness.
• the endometrium contains blood vessels and specialized cells which confer its functional characteristics to the endometrium.
• the endometrial epithelium constitutes a continuous cell layer which is organized in two regions: luminal epithelium (epithelial cells that line the surface of the endometrium) and glandular epithelium (epithelial cells that form glands beneath the surface of the endometrium), said regions being physically different and molecularly recognizable [Brown SE et al. Endometrial glycodelin-A expression in the luteal phase of stimulated ovarian cycles. Fertil Steril 2000, 74(1): 130-133].
• the luminal epithelium represents a physical barrier against the pathogens attacks and develops structures, denominated pinopodes, in its apical surface, which are responsible of the absorption of uterine lumen material; however, the glandular epithelium is responsible for the secretions which form the endometrial fluid, which contains all compounds secreted to the lumen of the uterus [Aplin JD et al. (2008) cited supra].
• the composition of the endometrial fluid depends on the endometrial gland activity instead of the endometrium as a whole, as it has been previously reported [van der Gaast et al. The feasibility of a less invasive method to assess endometrial maturation-comparison of simultaneously obtained uterine secretion and tissue biopsy. BJOG 2009, 116(2):304-312] - van der Gaast et al. show some proteins whose levels in endometrial tissue versus endometrial fluid is different and do not correspond each other.
• the present invention provides methods and kits for detecting endometrial receptivity to embryo implantation in a mammalian female; methods and kits for selecting the implantation window of an embryo in a mammalian female; methods and kits for assessing if a mammalian female is under conditions suitable for receiving and implanting an embryo; methods and kits for monitoring endometrial maturation; and methods and kits for in vitro fertilization in a mammalian female.
• said mammalian female is a female human or non-human primate, preferably a woman.
• said woman is a woman subjected to an in vitro fertilization (IVF) process.
• IVF in vitro fertilization
• the methods comprise detecting the level of a prostaglandin selected from the group consisting of PGE2, PGF2a, and combinations thereof, in an endometrial fluid sample from said mammalian female, where the level of said prostaglandin is correlated with endometrial receptivity to embryo implantation.
• the methods comprise detecting the level(s) of PGE2 and/or PGF2a in an endometrial fluid sample from said mammalian female, in one or more endometrial fluid samples obtained from a plurality of stages of the menstrual cycle of a mammalian female.
• the methods comprise collecting a lipidomic profile from a sample of endometrial fluid from said mammalian female and correlating said collected lipidomic profile with fertility status of said mammalian female.
• the methods of the present invention are based upon the discovery that the levels of said prostaglandins, PGE2 and PGF2a, follow a temporal pattern in endometrial fluid during the menstrual cycle, and that the levels of said prostaglandins in said endometrial fluid are increased during the implantation window, i.e., a window of time during which the uterine endometrium is receptive to conception.
• the invention relates to a method for detecting endometrial receptivity to embryo implantation in a mammalian female, hereinafter referred to as "method of the invention ⁇ 11", said method comprising the steps of:
• PGE2 prostaglandin E2
• PEF2a prostaglandin F2 alpha
• endometrial receptivity to embryo implantation refers to the state of the endometrium during the window of endometrial receptivity.
• window of endometrial receptivity refers to the time period between days 19 to 21 of an idealized 28 day human menstrual cycle. Similar cycles are known for other mammals and it is within the ordinary skill in the art to adapt methods described herein to such cycles.
• mamalian includes any mammal, for example, humans and non-human primates, cattle, goats, sheeps, horses, pigs, dogs, etc. In a preferred particular embodiment said mammal is a woman.
• woman refers to a human female.
• the mammalian female within the methods of the present invention is a woman and the stages of the menstrual cycle are selected from the group consisting of the early secretory phase and the mid- secretory phase.
• the levels of PGE2 and/or PGF2a are determined in a sample of endometrial fluid from the mammalian female (e.g., woman) under study.
• the endometrial fluid sample can be taken from said mammalian female by conventional means.
• a sample of endometrial fluid from a woman can be obtained as mentioned in Example 1, i.e., by gently introducing transcervically an empty flexible catheter into the uterine cavity and gradually applying a suction with a syringe.
• the method of the invention [1] can be performed daily, or each 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 or 28 days, so that the expression profile of said prostaglandins PGE2 and/or PGF2a in endometrial fluid samples can be determined along the full menstrual cycle.
• endometrial fluid samples can be obtained during the proliferative phase (days 1-14 of the menstrual cycle or before the LH peak), in the early secretory phase (days 15-19 of the menstrual cycle or days 1-5 after the LH peak), in the intermediate secretory phase (days 20-24 of the menstrual cycle or days 6-10 after the LH peak) and in the late secretory phase (days 25-28 of the menstrual cycle or days 11-14 after the LH peak).
• the levels of PGE2 and/or PGF2a in endometrial fluid during the endometrial receptivity to embryo implantation are the highest during the full menstrual cycle.
• the determination of the endometrium receptivity to embryo implantation is particularly important in a lot of techniques, such as IVF, embryo transfer, etc., as well as for determining the optimum period for conception in couples who are trying to conceive in a natural way.
• the term "level” is intended broadly and can mean a quantitative amount (e.g., weight or moles), a semi-quantitative amount, a relative amount (e.g., weight % or mole % within class or a ratio), a concentration, and the like.
• the levels of PGE2 and PGF2a are expressed in moles/gram of fluid [in that case, although samples were liquid, due to the small volume thereof, the samples were weighed and the concentrations of said compounds was expressed by reference to said weight - values were duly normalized] .
• the determination of the levels of PGE2 and/or PGF2a in the endometrial fluid sample can be determined by using any suitable method in view of the lipids to be detected and, optionally, quantified; illustrative, non-limitative, methods include thin layer chromatography (TLC), gas chromatography (GC), liquid chromatography (LC), mass spectrometry (MS), NMR spectrometry, etc., and combinations thereof (e.g., LC/MS or the like).
• TLC thin layer chromatography
• GC gas chromatography
• LC liquid chromatography
• MS mass spectrometry
• NMR spectrometry etc.
• said lipids (PGE2 and PGF2a) were identified by LC combined with tandem MS [LC/MS/MS].
• Tandem mass-spectrometers include triple quadrupole, ion trap, and quadrupole/time-of-flight instruments, among others. These instruments typically use quadrupole technology to isolate a compound based upon its molecular weight prior to collision activation (fragmentation) and mass analysis of the fragmented components. This means that the mixture must be purified only to the point that the sample applied to the mass spectrometer is free of other compounds with the same mass. This can often be accomplished with a liquid-liquid extraction from the tissue followed by solid phase extraction methods. Quadrupole technology provides approximately 1 amu resolution; improved isolation within the mass spectrometer is accomplished using TOF/TOF instruments, which permits much finer resolution.
• Bastani et al. who developed an analytical method based on LC with negative electrospray ionization (ESI) coupled to tandem mass spectrometric detection (LC/MS/MS) for the determination of PGF2ot derivatives concentrations in different biological samples [Bastani, N.E., et al. Determination of 8-epi PGF 2 ci concentrations as a biomarker of oxidative stress using triple-stage liquid chromatography/tandem mass spectrometry. Rapid Communications in Mass Spectrometry, Volume 23 Issue 18, pages 2885 - 2890 (published Online: 10 Aug 2009)].
• Another suitable method of detecting, and optionally quantifying, lipids in a biological sample employs stable isotope tracers to label the lipids.
• PGE2 and PGF2 levels are measured using liquid chromatography (LC) combined with tandem mass- spectrometry (MS) [LC/MS/MS].
• the levels of PGE2 and/or PGF2a can be based on quantitative and/or semi- quantitative analysis. For example, semi-quantitative methods can be used to determine a level of a particular lipid (PGE2 and/or PGF2a) metabolite(s) above a threshold value or to determine ratios of different lipid metabolites, without assigning an absolute or relative numerical value. Quantitative methods can be used to determine a relative or absolute amount of a particular lipid metabolite(s) in the biological sample.
• a threshold or cutoff value can be determined by any means known in the art, and is optionally a predetermined value.
• the threshold value is predetermined in the sense that it is fixed, for example, based on previous experience with the assay and/or a population of mammalian females (e.g., women).
• the term ' 'predetermined' ' value can also indicate that the method of arriving at the threshold is predetermined or fixed even if the particular value varies among assays or may even be determined for every assay run.
• the invention in another aspect, relates to a method for selecting the implantation window of an embryo in a mammalian female, hereinafter referred to as the "method of the invention ⁇ 21", which comprises determining the level of PGE2, the level of PGF2a, or the level of both PGE2 and PGF2a, in a sample of endometrial fluid from said mammalian female, wherein said implantation window is selected when the level of at least one of said prostaglandins PGE2 or PGF2a in said sample is increased in relation to a reference sample.
• the expression "method for selecting” relates to a method for determining the probability of a mammalian female (e.g., a woman) of being in a period receptive for embryo implantation.
• a mammalian female e.g., a woman
• said prediction cannot be correct for the 100% of the mammalian females (e.g., women) under study.
• said expression requires that the prediction method provides correct results for a statistically significant portion of mammalian females (e.g., women), what can be determined by using standard statistical techniques such as the confidence intervals determination, p value determination, t test of Student, or the Mann- Whitney test, as explained by Dowdy and Wearden, Statistics for Research, John Wiley & Sons, New York 1983.
• Suitable confidence intervals are, at least, 50%, at least 60%, at least 70%, at least 80%, preferably, at least 90%, or most preferable, at least 95%.
• p values are 0.2, 0.1, or, most preferably 0.05.
• the term "implantation window" encompasses the window of time during which the uterine endometrium is receptive to the conceptus; in humans, this occurs in the secretory stage of the menstrual cycle. Implantation is defined as days 6-8 post the day of the luteinising hormone (LH) surge.
• the implantation window can be estimated on the basis of a regular menstrual pattern as approximately 7 days before the expected first day of the menstrual period, i.e., it corresponds, therefore, to days 19- 21 of an ideal menstrual cycle of 28 days in humans. Similar cycles have been disclosed in other mammals, so that the method of the invention could be adapted to any mammalian female.
• the levels of PGE2 and/or PGF2a are determined in a sample of endometrial fluid from the mammalian female under study.
• said mammalian female is a woman.
• the endometrial fluid sample can be taken from said mammalian female by conventional means as mentioned in connection with method of the invention [1].
• the determination of the level of PGE2 and/or PGF2a in the endometrial fluid sample can be determined by using any suitable method as discussed in connection with the method of invention [1].
• the levels of PGE2 and PGF2a are measured by using liquid chromatography (LC) combined with tandem mass- spectrometry (MS) [LC/MS/MS].
• the determination of the levels of PGE2 and/or PGF2a needs to be correlated to the level of said prostaglandins in a reference sample.
• the implantation window is selected when the level of at least one of said prostaglandins PGE2 or PGF2a in the endometrial fluid sample analyzed is increased in relation to a reference sample.
• the level of a prostaglandin such as PGE2 or PGF2a in the endometrial fluid sample from the mammalian female under study is "increased in relation to" the level of said prostaglandins in a reference sample according to the instant invention, when the level of said prostaglandins in the endometrial fluid sample under study is at least, 1,1-fold, 1,5-fold, 5-fold, 10-fold, 20- fold, 30-fold, 40-fold, 50-fold, 60-fold, 70-fold, 80-fold, 90-fold, 100-fold or even more with respect to the reference sample.
• the term "reference sample” relates to an endometrial fluid sample obtained from a mammalian female, e.g., a woman, during the non-fertile period of said mammal. Due to the eventual variability which may exist among different mammalian females (e.g., women) as to the production of said prostaglandins during the non-fertile period, the reference sample can be typically obtained by combining the same amounts of samples of a population of mammalian females. In a particular embodiment, typical reference samples will be obtained from clinically well- documented women.
• normal concentrations (i.e., reference concentrations) of the biomarker can be determined, for example, by establishing the average concentration on the reference population.
• some considerations should be born in mind, e.g., age, etc.
• the same amounts of a group of at least 2, at least 10, at least 100, preferably, more than 1,000 mammalian females, e.g., women, preferably sorted bearing in mind the above mentioned considerations (e.g., age, etc.) can be taken as the reference group.
• the reference sample is obtained from the endometrial fluid from a woman, or from a population of women, during the non-fertile period of said woman/women.
• the reference sample can be obtained at any day during the non-fertile period of said woman/women, in a particular embodiment, said reference sample is obtained before the 15 th day of the menstrual cycle, typically between days 5-11 of the menstrual cycle.
• the predetermined value can be calculated by using the endometrial fluid samples of the menstrual cycle stage as defined above.
• the method of the invention [2] can be performed daily, or each 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 or 28 days, so that the expression profile of said prostaglandins PGE2 and/or PGF2a can be determined along the full menstrual cycle.
• endometrial fluid samples can be obtained during the proliferative phase (days 1-14 of the menstrual cycle or before the LH peak), in the early secretory phase (days 15-19 of the menstrual cycle or days 1-5 after the LH peak), in the intermediate secretory phase (days 20-24 of the menstrual cycle or days 6-10 after the LH peak) and in the late secretory phase (days 25-28 of the menstrual cycle or days 11-14 after the LH peak).
• the optimal implantation window will correspond to the period of time in which the levels of PGE2 and/or PGF2a are the highest during the full menstrual cycle.
• the reference sample is obtained from the same mammalian female (e.g., woman) under study during her non-fertile days in order to quantify the level(s) of said prostaglandins (PGE2 and/or PGF2a); said information can be used as a reference value.
• the reference sample is obtained from a generalised mammalian female population (e.g., a population of women) during their non-fertile days and the level(s) of said prostaglandins (PGE2 and/or PGF2a) are quantified and combined to establish the reference value.
• a generalised mammalian female population e.g., a population of women
• PGE2 and/or PGF2a prostaglandins
• bioactive lipids in endometrial secretions are analysed to determine their relative levels and establish a correlation with implantation and pregnancy outcome.
• the invention relates to a method for assessing the fertility status of a mammalian female wherein said method comprises:
• the levels of PGE2 and/or PGF2a in a sample of endometrial fluid from the mammalian female under study, obtained as mentioned above, can be determined by using any suitable method as discussed in connection with the method of invention [1].
• This method is aimed at assessing levels of said prostaglandin(s) PGE2 and/or
• PGF2a in endometrial fluid samples during the implantation window in the endometrium of said mammalian female The PGE2 and/or PGF2a levels in endometrial fluid correlate with endometrial receptivity and likelihood of conception.
• knowing the levels of PGE2 and/or PGF2a in a sample of endometrial fluid from said mammalian female it is possible to know the most fertile days of her menstrual cycle wherein the optimal conditions for getting pregnant are satisfied.
• said mammalian female is a woman.
• the invention relates to a method for assessing if a mammalian female is under conditions suitable for receiving and implanting an embryo, wherein said method comprises: determining the level of PGE2, the level of PGF2a or the level of both PGE2 and PGF2a in a sample of endometrial fluid from said mammalian female, and
• the levels of PGE2 and/or PGF2a in a sample of endometrial fluid from the mammalian female under study, obtained as mentioned above, can be determined by using any suitable method as discussed in connection with the method of invention [1]. This method is also aimed at assessing levels of said prostaglandin(s) PGE2 and/or PGF2a during the implantation window in the endometrium of said mammalian female.
• the PGE2 and/or PGF2a levels are correlated with the conditions of the receiving mammalian females for receiving and implanting an embryo and likelihood of conception.
• knowing the levels of PGE2 and/or PGF2a in a sample of endometrial fluid from said mammalian female it is possible to know the most suitable days for a mammalian female for receiving and implanting an embryo.
• said mammalian female is a woman, preferably a woman subjected to an in vitro fertilization (IVF) process.
• IVF in vitro fertilization
• the PGE2 and/or PGF2a levels are correlated with the conditions of the receiving woman for receiving and implanting an embryo and likelihood of conception.
• the sample of endometrial fluid from said woman can be obtained at any time before implanting the embryo, e.g., from some minutes (e.g., 15 minutes) to some hours (e.g., 4-6 hours), or even some days (e.g., 1, 7, 14, or even more) before the embryo transfer.
• this method is planned to be performed on the endometrial fluid obtained in a non-disruptive fashion 5-6 hours prior to embryo transfer.
• the ability to identify specific lipid mediators in endometrial secretions that act as biomarkers of endometrial receptivity is of great importance to the IVF process.
• a stressful step for the woman is avoided.
• correct endometrial dating is inaccurately obtained, despite the development of non-invasive techniques such as ultrasound ecography or magnetic resonance, which only provide with morphological information of the uterus that has proven not reliable.
• the present invention provides a method for determining the biochemical characteristics of the uterus and an appropriate receptive endometrium a few hours prior to embryo transfer, thus increasing the chances for successful embryo implantation.
• the implantation rates could be improved by at least 5%, typically, at least 10%.
• the invention relates to a method for monitoring endometrial maturation in a mammalian female, said method comprising the steps of:
• the method for monitoring endometrial maturation in a mammalian female comprises the steps of:
• the levels of PGE2 and/or PGF2a in said samples of endometrial fluid from the mammalian female under study, obtained as mentioned above, can be determined by using any suitable method as discussed in connection with the method of invention [1].
• samples of endometrial fluid are obtained from a plurality of stages of the menstrual cycle of the mammalian female under study, for example, in the case of an idealized menstrual cycle of a woman, during the proliferative phase (days 1-14 of the menstrual cycle), in the early secretory phase (days 15-19 of the menstrual cycle), in the intermediate secretory phase (days 20-24 of the menstrual cycle) and in the late secretory phase (days 25-28 of the menstrual cycle), in order to be able to correlate the levels of said prostaglandins PGE2 and/or PGF2a with the endometrial maturation, thus knowing the state of the endometrium along the menstrual cycle.
• said mammalian female is a woman, e.g., a woman subjected to an IVF process.
• the invention relates to a method of in vitro fertilization in a mammalian female, said method comprising the steps of:
• step b) correlating the level(s) of said prostaglandin(s) PGE2 and/or PGF2a in one or more endometrial fluid samples of step b) with endometrial maturation; and c) introducing an embryo into the uterus of said mammalian female when said endometrium is mature.
• the method of in vitro fertilization in a mammalian female comprises the steps of:
• step c) correlating the level(s) of said prostaglandin(s) PGE2 and/or PGF2a in one or more endometrial fluid samples of step c) with endometrial maturation; and e) introducing an embryo into the uterus of said mammalian female when said endometrium is mature.
• the levels of PGE2 and/or PGF2a in said samples of endometrial fluid from the mammalian female under study, obtained as mentioned above, can be determined by using any suitable method as discussed in connection with the method of invention [1].
• samples of endometrial fluid are obtained from a plurality of stages of the menstrual cycle of the mammalian female under study, as discussed above, and once the endometrium is mature, an embryo is introduced into the uterus of said mammalian female.
• said mammalian female is a woman, e.g., a woman subjected to an IVF process.
• kit is intended any article of manufacture (e.g., a package or a container) comprising at least a reference lipid for PGE2 or a reference lipid for PGF2a.
• the kit may be promoted, distributed, or sold as a unit for performing the methods of the present invention. Additionally, the kits may contain a package insert describing the kit and instructions for using.
• the instructions describe methods for detecting endometrial receptivity to embryo implantation, or for selecting the implantation window of an embryo, or for assessing the fertility status, or for assessing if a mammalian female is under conditions suitable for receiving and implanting an embryo, or for monitoring endometrial maturation in a mammalian female, or for in vitro fertilization in a mammalian female.
• the kit may also comprise, in addition to said reference lipids for PGE2 and/or PGF2a (e.g., PGE2 and/or PGF2a lipids of known purity and concentration) one or more reagents, said reagents being selected in function of the technique selected for determining the level of PGE2 and/or PGF2a - the skilled person in the art knows the reagents which are necessary to perform a specific technique for determining the level of said lipids.
• PGE2 and/or PGF2a e.g., PGE2 and/or PGF2a lipids of known purity and concentration
• Said kit can be used for detecting endometrial receptivity to embryo implantation in a mammalian female, or for selecting the implantation window of an embryo in a mammalian female, or for assessing the fertility status of a mammalian female, or for assessing if a mammalian female is under conditions suitable for receiving and implanting an embryo, or for monitoring endometrial maturation in a mammalian female, or for in vitro fertilization in a mammalian female.
• said kit can be used for an accurate analytical assessment of samples that are predictive of a receptive endometrium hours before the embryo transfer procedure.
• the previously mentioned uses of the kit constitute a further aspect of this invention.
• the invention provides a number of non-invasive diagnostic methods, and kits for performing said methods, based on the identification of the lipid profile in the endometrial fluid during the implantation window.
• said lipid profile comprises PGE2 and/or PGF2a.
• the methods provided by the instant invention are expected to increase current implantation rates by, at least 5%, preferably, at least 10%.
• An improvement of implantation rates is of benefit to both the medical community and patients by providing with a better medical assistance with increased chances of successful outcomes.
• the methods and kits provided by the instant invention will provide the medical community with a powerful tool in the diagnosis of endometrial receptivity prior to embryo transfer in IVF treatments. Said methods will eliminate the necessity for invasive approaches, and will improve current implantation rates by offering real-time biochemical read-outs of endometrial receptivity only a few hours before the embryo transfer procedure. Patients consequently avoid upsetting biopsy-collection processes.
• the invention further provides a method for identifying a compound capable of enhancing endometrium receptivity as well as a method for identifying a contraceptive agent.
• the invention further provides a method for identifying a compound capable of enhancing endometrium receptivity, which comprises:
• said candidate compound is suitable for enhancing endometrium receptivity if said compound causes an increase in the production of said PGE2 and/or PGF2a by said cell.
• the invention further provides a method for identifying a contraceptive agent, which comprises:
• said candidate compound is suitable as a contraceptive agent if said compound causes a decrease in the production of said PGE2 and/or PGF2a by said cell.
• the candidate compound to be tested in said method for identifying a compound capable of enhancing endometrium receptivity or for identifying a contraceptive agent can be practically any chemical compound, including both low molecular weight compounds and macromolecules such as proteins, nucleic acids, lipids and the like.
• the expression "contacting”, as used herein, includes any possible way of introducing the candidate compound into said PGE2 and/or PGF2a producing cells.
• said PGE2 and/or PGF2a producing cell can be an epithelial cell of the endometrium [epithelial endometrium cell], preferably, a human epithelial endometrium cell; in another particular embodiment, said PGE2 and/or PGF2a producing cell is a cell line from endometrium, preferably, a human cell line from endometrium, said cell having the ability of producing PGE2 and/or PGF2a.
• the level of said PGE2 and/or PGF2a can be determined in the culture medium by any of the techniques previously mentioned.
• said PGE2 and/or PGF2a producing cells are present in an animal model; then, the level of said PGE2 and/or PGF2a can be determined in a sample from the endometrial fluid from said animal model by any of the techniques previously mentioned.
• An increase in the production of said PGE2 and/or PGF2a may be indicative that the candidate compound is suitable for potentially enhancing or increasing the endometrium receptivity for implanting an embryo.
• a decrease in the production of said PGE2 and/or PGF2a may be indicative that the candidate compound can be used as a contraceptive agent since said compound reduces the endometrium receptivity for implanting an embryo.
• the invention relates to a lipid composition, wherein said lipid composition has been obtained from an endometrial fluid sample from a mammalian female during the implantation window of an embryo in said mammalian female.
• Said lipid composition can be used for determining endometrial receptivity for implanting an embryo.
• said mammalian female is a woman.
• said lipid composition comprises a lipid selected from the following lipids N-arachidonoyl ethanolamine (AEA), N-palmitoyl ethanolamine (PEA), N-oleoyl ethanolamine (OEA), 2-arachidonoyl glycerol 2-AG), N- stearoyl ethanolamine (SEA), N-linoleoyl ethanolamine (LEA), prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2a), prostaglandin Fl alpha (PGFl ) and combinations thereof.
• AEA N-arachidonoyl ethanolamine
• PEA N-palmitoyl ethanolamine
• OEA N-oleoyl ethanolamine
• 2-arachidonoyl glycerol 2-AG N- stearoyl ethanolamine
• SEA N-linoleoyl ethanolamine
• PGE2 prostaglandin E2
• PPF2a prostaglandin F
• said lipid composition comprises a prostaglandin selected from the group consisting of PGE2, PGF2a, and combinations thereof because the levels of said specific lipid(s) is/are significant increased in endometrial fluid samples between days 19 to 21 of the menstrual cycle of a woman, coincident with the implantation window.
• a prostaglandin selected from the group consisting of PGE2, PGF2a, and combinations thereof because the levels of said specific lipid(s) is/are significant increased in endometrial fluid samples between days 19 to 21 of the menstrual cycle of a woman, coincident with the implantation window.
• the invention relates to a method for selecting the implantation window of an embryo in a mammalian female comprising the steps:
• the sample of endometrial fluid from the mammalian female under study can be obtained by conventional methods as discussed above.
• Obtaining a lipidomic profile from said sample of endometrial fluid from the mammalian female under study can be performed with various chemical and high resolution analytical techniques.
• Suitable analytical techniques include but are not limited to mass spectrometry (MS) and nuclear resonance spectroscopy (NRS). Any high resolution technique capable of re-solving individual lipids or lipid classes and provides structural information of the same can be used to collect the lipid profile from said biological sample.
• MS mass spectrometry
• NRS nuclear resonance spectroscopy
• Any high resolution technique capable of re-solving individual lipids or lipid classes and provides structural information of the same can be used to collect the lipid profile from said biological sample.
• Collecting the lipidomic profile with mass spectrometry (MS) is one embodiment of the current invention.
• the MS instrument can be coupled to a high performance separation method such as HPLC.
• the analytical technique used for collecting the lipidomic profile should be able to quantify or measure either the exact amount or at least a relative amount of the individual lipids or lipid classes.
• the amount of the individual lipids or lipid classes in the collected lipidomic profile is used when comparing the collected lipid profile to the reference lipidomic biomarkers.
• the levels of the lipids are determined by LC/MS/MS, as discussed below.
• the reference lipidomic biomarkers can be established from the same mammalian female under study or it can be from a generalised population. If the same mammalian females are used to create the reference lipidomic biomarker, then a sample could be collected from said mammalian female during the non-fertile days thereof. The reference lipidomic biomarker is then created from that first lipid profile of that mammalian female. This lipidomic biomarker is used as a base-line or starting point. A series of lipidomic profiles can be collected along the menstrual cycle. These lipidomic profiles are then compared with the reference lipidomic biomarker previously created.
• the reference lipidomic biomarkers can also be created from a generalized population of mammalian females. If a generalized population is used then several lipid profiles from said are combined and the lipidomic biomarker is created from this combination.
• the reference lipidomic biomarkers are one or more lipid(s) selected from the following lipids N-arachidonoyl ethanolamine (AEA), N- palmitoyl ethanolamine (PEA), N-oleoyl ethanolamine (OEA), 2-arachidonoyl glycerol (2- AG), N-stearoyl ethanolamine (SEA), N-linoleoyl ethanolamine (LEA), prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2a), prostaglandin Fl alpha (PGFl ) and combinations thereof.
• AEA N-arachidonoyl ethanolamine
• PEA N- palmitoyl ethanolamine
• OEA N-oleoyl ethanolamine
• SEA N-stearoyl ethanolamine
• LAA N-linoleoyl ethanolamine
• PGE2 prostaglandin
• said lipid profile comprises a prostaglandin selected from the group consisting of PGE2, PGF2a, and combinations thereof because the levels of said specific lipid(s) is/are significant increased in endometrial fluid samples between days 19 to 21 of the menstrual cycle of a woman, coincident with the implantation window.
• kits comprising reference lipids to form the lipidomic reference biomarkers.
• the kit may be promoted, distributed, or sold as a unit for performing the above mentioned method.
• the kit may contain a package insert describing the kit and instructions for using.
• the instructions describe methods for detecting endometrial receptivity to embryo implantation, or for selecting the implantation window of an embryo, or for assessing the fertility status, or for assessing if a mammalian female is under conditions suitable for receiving and implanting an embryo, or for monitoring endometrial maturation in a mammalian female, or for in vitro fertilization in a mammalian female.
• the kit may also comprise, in addition to said reference lipids to form the lipidomic reference biomarkers one or more reagents, said reagents being selected in function of the technique selected for determining the level of the lipids in the endometrial fluid sample to be analyzed - the skilled person in the art knows the reagents which are necessary to perform a specific technique for determining the level of said lipids.
• Said kit can be used for detecting endometrial receptivity to embryo implantation in a mammalian female, or for selecting the implantation window of an embryo in a mammalian female, or for assessing the fertility status of a mammalian female, or for assessing if a mammalian female is under conditions suitable for receiving and implanting an embryo, or for monitoring endometrial maturation in a mammalian female, or for in vitro fertilization in a mammalian female.
• said kit can be used for an accurate analytical assessment of samples that are predictive of a receptive endometrium hours before the embryo transfer procedure.
• the previously mentioned uses of the kit constitute a further aspect of this invention.
• the concentration of PGE2 and PGF2a is significantly increased during the window of implantation 1.1 Materials
• HPLC-grade methanol and acetonitrile used for mass spectrometric studies were purchased from VWR international (Plain view, NY).
• HPLC grade water, mass spectrometry/HPLC grade acetic acid, formic acid, and ammonium acetate were purchased from Sigma- Aldrich (St. Louis, MO).
• the outer sheath of the embryo transfer catheter was advanced to a depth of 4 cm from the external cervical os, following the application of suction. Cervical mucus was aspirated prior to endometrial secretion aspiration for within patient comparison, in order to verify whether the aspirates represented cervical mucus rather than endometrial secretions.
• Tandem mass-spectrometers include triple quadrupole, ion trap, and quadrupole/time- of-flight instruments, among others. These instruments typically use quadrupole technology to isolate a compound based upon its molecular weight prior to collision activation (fragmentation) and mass analysis of the fragmented components. This means that the mixture must be purified only to the point that the sample applied to the mass spectrometer is free of other compounds with the same mass. This can often be accomplished with a liquid-liquid extraction from the tissue followed by solid phase extraction methods. Quadrupole technology provides approximately 1 amu resolution; improved isolation within the mass spectrometer is accomplished using TOF/TOF instruments, which permit much finer resolution.
• PGE2 and/or PGF2a could be important biomarkers of human endometrial receptivity during the window of implantation.

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Molecular Biology (AREA)
• Biomedical Technology (AREA)
• Immunology (AREA)
• Urology & Nephrology (AREA)
• Hematology (AREA)
• Chemical & Material Sciences (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Cell Biology (AREA)
• Food Science & Technology (AREA)
• Medicinal Chemistry (AREA)
• Physics & Mathematics (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• Microbiology (AREA)
• Biotechnology (AREA)
• Pathology (AREA)
• Surgery (AREA)
• Biophysics (AREA)
• Endocrinology (AREA)
• Tropical Medicine & Parasitology (AREA)
• Toxicology (AREA)
• Bioinformatics & Cheminformatics (AREA)
• Gynecology & Obstetrics (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Heart & Thoracic Surgery (AREA)
• Medical Informatics (AREA)
• Animal Behavior & Ethology (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Reproductive Health (AREA)
• Pregnancy & Childbirth (AREA)
• Transplantation (AREA)
• Investigating Or Analysing Biological Materials (AREA)
• Other Investigation Or Analysis Of Materials By Electrical Means (AREA)

Priority Applications (10)

Applications Claiming Priority (2)

Publications (1)

Family

ID=42200845

Family Applications (1)

Country Status (10)

Cited By (5)

Families Citing this family (16)

Citations (1)

Family Cites Families (7)

• 2010
  • 2010-01-21 EP EP10382011A patent/EP2348318A1/en not_active Withdrawn
• 2011
  • 2011-01-21 US US13/574,291 patent/US20130144114A1/en not_active Abandoned
  • 2011-01-21 EP EP11700679.1A patent/EP2526425B1/en not_active Not-in-force
  • 2011-01-21 JP JP2012549374A patent/JP5732664B2/ja not_active Expired - Fee Related
  • 2011-01-21 WO PCT/EP2011/050867 patent/WO2011089240A1/en not_active Ceased
  • 2011-01-21 DK DK11700679.1T patent/DK2526425T3/da active
  • 2011-01-21 CA CA2787582A patent/CA2787582A1/en not_active Abandoned
  • 2011-01-21 CN CN201180010375.0A patent/CN102792166B/zh not_active Expired - Fee Related
  • 2011-01-21 ES ES11700679.1T patent/ES2485847T3/es active Active
  • 2011-01-21 PL PL11700679T patent/PL2526425T3/pl unknown
  • 2011-01-21 BR BR112012018289-7A patent/BR112012018289A2/pt not_active IP Right Cessation

Patent Citations (1)

Non-Patent Citations (33)

Also Published As

Similar Documents

Legal Events