Follicle-stimulating hormone (and luteinizing hormone) in ovarian stimulation: Does the dose matter for cycle success?

In this review, we have summarized the evolution in our understanding of a relevance of gonadotropin dosing for cycle outcomes in women attempting to conceive through the utilization of the in vitro fertilization technology.

The selective progesterone receptor modulator, telapristone acetate, is a mixed antagonist/agonist in the human and mouse endometrium and inhibits pregnancy in mice

OBJECTIVE

To investigate the effect of the selective progesterone receptor modulator, telapristone acetate (CDB-4124), on endometrial biology and reproductive outcomes. Ovariectomized and hormone-treated CD1 female mice, CD1 female mice with xenotransplants of reconstructed human endometrial tissue, mated wildtype female mice, and cultured human endometrial stromal cells (hESCs) were treated with CDB-4124, followed by the assessment of endometrial cell deoxyribonucleic acid (DNA) proliferation, stromal decidual response, and embryo implantation.

DESIGN

Experimental study.

SETTING

Academic research laboratory.

PATIENTS

Healthy volunteer women from the community were recruited for endometrial biopsies.

ANIMALS

CD1 out-bred mice (Charles River Laboratories) and nude mice, NU/J (Jackson Laboratories, Bar Harbor, ME).

INTERVENTION

Treatment of mice and hESCs with CDB-4124.

MAIN OUTCOME MEASURE

The effect of CDB-4124 on endometrial cell morphology and DNA synthesis, decidual response, and mouse embryo implantation.

RESULTS

CDB-4124 inhibited estradiol-induced epithelial DNA synthesis in the mouse uterus and xenotransplanted human endometrium. This antiproliferative effect was less than that of progesterone (P4) and was observed when CDB-4124 was administered alone or concomitantly with P4. In the uterine epithelium, CDB-4124 acted as a P4 agonist and partial antagonist. In contrast, CDB-4124 acted as a complete P4 antagonist in the uterine stroma, where it blocked P4's action to induce a decidual response in the pseudopregnant mouse uterus and wildtype mouse uterus after copulation. In mated female mice, CDB-4124 impaired embryo implantation. Similarly, CDB-4124 inhibited the morphological and biochemical transformations of hESCs to decidual cells in vitro.

CONCLUSION

CDB-4124 exerts mixed P4 antagonistic/agonistic effects in the human and mouse endometrium, which result in failed embryo implantation because of the absence of stromal decidualization.

Xenografted tissue models for the study of human endometrial biology

The human endometrium undergoes extensive morphological, biochemical and molecular changes under the influence of female sex steroid hormones. Besides the fact that estrogen stimulates endometrial cell proliferation and progesterone inhibits this proliferation and induces differentiation, there is limited knowledge about precise molecular mechanisms underlying human endometrial biology. The importance of paracrine signaling in endometrial physiology explains why in vitro culture of endometrial cells has been challenging. Researchers, therefore, have developed alternative experimental in vivo models for the study of endometrial biology. The objective of this review is to summarize the recent developments and work on these in vivo endometrial research models. The in vivo recombinant tissue models in which wild-type endometrial cells are combined with endometrial cells from a gene-targeted mouse strain followed by xenografting to host mice have been critical in confirming the significance of paracrine signaling between the epithelium and stroma in the growth regulation of the endometrium. Additionally, these studies have uncovered differences between the mouse and human, emphasizing the need for the development of experimental models specifically of the human endometrium. Recently, xenotransplants of human endometrial fragments into the subcutaneous space of host mice and endometrial xenografts of dissociated and recombined epithelial and stromal cells beneath the kidney capsule of immunodeficient host mice have proven to be highly promising tools for in vivo research of endometrial functions. For the first time, the latter approach provides an immense opportunity for the application of genome engineering, such as targeted ablation of endometrial genes for example by using CRISPR/CAS9 system. This research will begin to elucidate the functional role of specific genes in this complex tissue. Another advantage of xenotransplantation and xenograft models of the human endometrium is their use to investigate endometrial effects of new compounds and drugs without needing to give them to women. Underpinning the molecular mechanisms underlying endometrial functions is critical to ultimately advance our understanding of endometrial pathophysiology and develop targeted therapies to prevent and cure endometrial pathologies as well as enhance endometrial function when it is desired for fertility.

Thin endometrium after radiation therapy as an unresolved treatment challenge: a case report

Receptive endometrium is essential for successful implantation and ongoing pregnancy. Significant health issues and associated therapies, especially oncologic therapies, have potential to negatively impact future fertility in young women. Irradiation and chemotherapeutic alkylating agents are known to cause ovarian failure in most females; however, less well is characterized the impact of irradiation on uterine development and integrity. With an increasing number of cancer survivors, women are seeking infertility treatment after such therapies. Here, we present a young woman who developed ovarian failure after the treatment of acute myeloid leukemia with bone marrow transplant and preceding irradiation and chemotherapy and who was diagnosed with thin endometrial lining while seeking infertility therapy.

Corpus luteum as a novel target of weight changes that contribute to impaired female reproductive physiology and function

Obesity and malnutrition are associated with decreased fecundity in women. Impaired reproductive capacity in obese women is often attributed to anovulation. However, obese women with ovulatory cycles also have reduced fertility, but the etiology of their impaired reproduction is only partially understood. Accumulating evidence suggests that obesity directly impairs oocyte and embryo quality as well as endometrial receptivity. In obese women, urinary progesterone metabolite excretion is decreased, but in excess of what can be explained by suppressed gonadotropin secretion, suggesting that apart from its central effect obesity may directly affect progesterone (P4) production. These observations have led to the novel hypothesis that obesity directly affects corpus luteum (CL) function. Similarly, we hypothesize that weight loss may contribute to luteal dysfunction. Here, we propose a non-human primate model, the vervet monkey, to examine the effect of weight gain and loss on menstrual cycle parameters and CL gene expression. In this model, weight gain and loss did not significantly alter menstrual cyclicity; however, both induced alterations in the CL transcriptome. In the weight gain monkey, we observed that impaired mid-luteal P4 secretion was associated with downregulation of steroidogenic pathways in CL. Collectively, these preliminary findings support our hypothesis that weight gain and loss may contribute to CL dysfunction. The vervet model described and preliminary observations provide a basis for a larger study to address this important question. Understanding the mechanisms by which weight gain and loss contribute to reproductive dysfunction can assist in the development of targeted treatments to enhance women's reproductive capability when it is desired.

ABBREVIATIONS

CL: corpus luteum; P4: progesterone; E2: estradiol; PDG: pregnanediol 3-glucoronide; LH: luteinizing hormone; FSH: follicle-stimulating hormone; GnRH: gonadotropin releasing hormone; BMI: body mass index; qrtPCR: quantitative real-time PCR; PGR: progesterone receptor; ART: assisted reproductive technology; IVF: in vitro fertilization; HPO: hypothalamic-pituitary-ovarian axis; MMPs: matrix metalloproteinases Gene symbols: LH receptor (LHGCR); cholesterol side-chain cleavage enzyme (CYP11A1); 3 beta-hydroxysteroid dehydrogenase type II (HSD3B2); steroidogenic acute regulatory protein (STAR); LDL receptor (LDLR); scavenger receptor B1 (SCARB1); ATP-binding cassette sub-family A member 1 (ABCA1); ATP-binding cassette sub-family G member 1 (ABCG1); apolipoprotein A (APOA1); 24 dehydrocholesterol reductase (DHCR24); 3-hydroxy-3-methylglytaryl-CoA reductase (HMGCR); vascular endothelial growth factor A (VEGFA); vascular endothelial growth factor C (VEGFC); vascular endothelial growth factor receptor 1 (VEGFR1); and TIMP metallopeptidase inhibitor 1 (TIMP1); amphiregulin (AREG); epiregulin (EREG); CCAAT/enhancer binding protein alpha (CEBPBA); cAMP responsive element binding protein 3-like 1 (CREB3L1); ADAM metallopeptidase with thrombospodin type 1 motif 1 (ADAMTS1); matrix metallopeptidase 9 (MMP9); cytochrome b-245 beta polypeptide (CYBB or NOX2); NADH oxidase (NCF2 or NOXA2); Fc fragment of IgG receptor IIb (FCGR2B); Fc fragment of IgG receptor IIb (FCGR2C); ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1); RAB27A member RAS oncofamily (RAB27A); hydroxyprostaglandin dehydrogenase (HPGD); prostaglandin-endoperoxidase synthase 1 (PTGS1); integrin B2 (ITGB2); leukotriene A4 hydrolase (LTA4H); radixin (RDX); ezrin (EZR); nuclear receptor subfamily 5 group A member 2 (NR5A2).

Joint MiRNA/mRNA expression profiling reveals changes consistent with development of dysfunctional corpus luteum after weight gain

Obese women exhibit decreased fertility, high miscarriage rates and dysfunctional corpus luteum (CL), but molecular mechanisms are poorly defined. We hypothesized that weight gain induces alterations in CL gene expression. RNA sequencing was used to identify changes in the CL transcriptome in the vervet monkey (Chlorocebus aethiops) during weight gain. 10 months of high-fat, high-fructose diet (HFHF) resulted in a 20% weight gain for HFHF animals vs. 2% for controls (p = 0.03) and a 66% increase in percent fat mass for HFHF group. Ovulation was confirmed at baseline and after intervention in all animals. CL were collected on luteal day 7-9 based on follicular phase estradiol peak. 432 mRNAs and 9 miRNAs were differentially expressed in response to HFHF diet. Specifically, miR-28, miR-26, and let-7b previously shown to inhibit sex steroid production in human granulosa cells, were up-regulated. Using integrated miRNA and gene expression analysis, we demonstrated changes in 52 coordinately regulated mRNA targets corresponding to opposite changes in miRNA. Specifically, 2 targets of miR-28 and 10 targets of miR-26 were down-regulated, including genes linked to follicular development, steroidogenesis, granulosa cell proliferation and survival. To the best of our knowledge, this is the first report of dietary-induced responses of the ovulating ovary to developing adiposity. The observed HFHF diet-induced changes were consistent with development of a dysfunctional CL and provide new mechanistic insights for decreased sex steroid production characteristic of obese women. MiRNAs may represent novel biomarkers of obesity-related subfertility and potential new avenues for therapeutic intervention.

Activation of protein synthesis in mouse uterine epithelial cells by estradiol-17β is mediated by a PKC-ERK1/2-mTOR signaling pathway

The uterine epithelium of mice and humans undergoes cyclical waves of cell proliferation and differentiation under the regulation of estradiol-17β (E2) and progesterone (P4). These epithelial cells respond to E2 with increased protein and DNA synthesis, whereas P4 inhibits only the E2-induced DNA synthetic response. Here we show that E2 regulates protein synthesis in these epithelial cells through activating PKC that in turn stimulates ERK1/2 to phosphorylate and thereby activate the central regulator of protein synthesis mechanistic target of rapamycin (mTOR). This mTOR pathway is not inhibited by P4. Inhibitor studies with an estrogen receptor (ESR1) antagonist showed the dependence of this mTOR pathway on ESR1 but that once activated, a phosphorylation cascade independent of ESR1 propagates the pathway. E2 also stimulates an IGF1 receptor (IGF1R) to PI3 kinase to AKT to GSK-3β pathway required for activation of the canonical cell cycle machinery that is inhibited by P4. PKC activation did not stimulate this pathway nor does inhibition of PKC or ERK1/2 affect it. These studies therefore indicate a mechanism whereby DNA and protein synthesis are regulated by two ESR1-activated pathways that run in parallel with only the one responsible for the initiation of DNA synthesis blocked by P4. Inhibition of mTOR by rapamycin in vivo resulted in inhibition of E2-induced protein and DNA synthesis. Proliferative diseases of the endometrium such as endometriosis and cancer are common and E2 dependent. Thus, defining this mTOR pathway suggests that local (intrauterine or peritoneal) rapamycin administration might be a therapeutic option for these diseases.

Genomic profiling of microRNAs and messenger RNAs reveals hormonal regulation in microRNA expression in human endometrium

MicroRNAs (miRNAs), a class of small noncoding RNAs that regulate gene expression, have fundamental roles in biological processes, including cell differentiation and proliferation. These small molecules mainly direct either target messenger RNA (mRNA) degradation or translational repression, thereby functioning as gene silencers. Epithelial cells of the uterine lumen and glands undergo cyclic changes under the influence of the sex steroid hormones estradiol-17beta and progesterone. Because the expression of miRNAs in human endometrium has been established, it is important to understand whether miRNAs have a physiological role in modulating the expression of hormonally induced genes. The studies herein establish concomitant differential miRNA and mRNA expression profiles of uterine epithelial cells purified from endometrial biopsy specimens in the late proliferative and midsecretory phases. Bioinformatics analysis of differentially expressed mRNAs revealed cell cycle regulation as the most significantly enriched pathway in the late proliferative-phase endometrial epithelium (P = 5.7 x 10(-15)). In addition, the WNT signaling pathway was enriched in the proliferative phase. The 12 miRNAs (MIR29B, MIR29C, MIR30B, MIR30D, MIR31, MIR193A-3P, MIR203, MIR204, MIR200C, MIR210, MIR582-5P, and MIR345) whose expression was significantly up-regulated in the midsecretory-phase samples were predicted to target many cell cycle genes. Consistent with the role of miRNAs in suppressing their target mRNA expression, the transcript abundance of predicted targets, including cyclins and cyclin-dependent kinases, as well as E2F3 (a known target of MIR210), was decreased. Thus, our findings suggest a role for miRNAs in down-regulating the expression of some cell cycle genes in the secretory-phase endometrial epithelium, thereby suppressing cell proliferation.

Linkage disequilibrium between the MBP tetranucleotide repeat and multiple sclerosis is restricted to a geographically defined subpopulation in Finland

We have previously found evidence for linkage as well as allelic and haplotype association between the myelin basic protein (MBP) gene and multiple sclerosis (MS). These findings have, however, not been reproduced in other populations. Here, we have analyzed association between MBP and MS in a new set of 349 Finnish triad families. Families with a parent born in the Southern Ostrobothnian region in western Finland (Bothnia families, n=98) were analyzed as a separate group since our previous studies included a high proportion of patients and families from this high-incidence region. Other families (n=251) were collected at five hospitals in southern, eastern, and northern Finland. The MBP short tandem repeat was genotyped, and haplotype patterns were verified by sequencing. In the Bothnia families, the previously detected associations with the 1.27 kb allele and haplotype 1.27-B10 were confirmed (P=0.01 and 0.02, respectively), whereas in the other families there was not even a trend toward association. These results demonstrate a geographic/genealogical restriction in the association between MS and the MBP short tandem repeat, highlight the importance of genealogical information in genetic studies of complex traits, and may provide an explanation why the association has not been found in many other populations.

Intercellular adhesion molecule-1 K469E polymorphism: study of association with multiple sclerosis

Intercellular adhesion molecule-1 (ICAM-1) is involved in the pathogenesis of multiple sclerosis (MS), whereas sequence variations in the ICAM-1 gene could potentially be responsible for the genetic susceptibility to MS. We studied an association of MS with the 13,848A>G (K469E) polymorphism of the ICAM-1 gene in Finnish and Spanish cases and controls and affected families. An increased risk for the AA (Lys(469)/Lys(469)) genotype was found in both populations. The effect observed was found to be strongest among the HLA-DQB1*0602-positive subjects, which implies genetic heterogeneity of MS. Meta-analysis of all published datasets supports increased risk of MS for the ICAM-1 Lys(469) homozygotes (relative risk = 1.3, p = 0.002).

Fine mapping of a multiple sclerosis locus to 2.5 Mb on chromosome 17q22-q24

Genome-wide linkage analyses performed in a Finnish study sample have identified four potential predisposing loci for multiple sclerosis (MS). Here we made an effort to restrict the wide linkage region on chromosome 17 with a dense set of 31 markers using multipoint linkage analyses and monitoring for shared marker alleles in MS chromosomes. We carried out the linkage analyses in 22 Finnish multiplex MS families originating from a regional subisolate that shows an exceptionally high prevalence of MS in order to minimize the genetic and environmental heterogeneity of the study sample. Thirty markers on the 23 cM initial interval gave positive pairwise LOD scores. We monitored for shared haplotypes among affected family members within a family, and identified an approximately 4 cM region flanked by the markers D17S1792 and ATA43A10 in 17 out of the 22 families (77.3%). The multipoint linkage analyses using Genehunter and SIMWALK 2.40 provided further evidence for the same 4 cM region, for example a maximal multipoint NPL score of 5.98 (P<0.0002). We observed nominal evidence for association to MS, with one marker flanking the shared region, and this association was replicated in the additional set of families. Using the combined power of linkage, association and shared haplotype analyses, we were thus able to restrict the MS locus on chromosome 17q from 23 cM to a 4 cM region covering a physical interval of approximately 2.5 Mb. Thus, this study describes the restriction of an MS locus outside the HLA region into a segment approachable by molecular tools.

Chromosome 19q13 and multiple sclerosis susceptibility in Finland: a linkage and two-stage association study

Several studies have previously provided some albeit weak evidence for linkage or association between chromosome 19q13 and multiple sclerosis (MS) susceptibility. We performed a two-stage association analysis with 19 markers spanning 7 Mb/5.5 cM of 19q13. In stage 1 analysis (135 MS families) allelic and haplotypic associations were found with markers within or close to the ApoE-ApoC subregion. These observations were taken as a hypothesis, which was tested in stage 2 in 125 families. However, none of the initial associations were replicated suggesting that they were most likely due to chance. Linkage analysis was performed in 27 Finnish multiplex families using 10 microsatellites spanning 23 Mb/24 cM of 19q13. DNA was available from 72 MS patients and 150 unaffected relatives. Parametric and non-parametric linkage analyses did not provide evidence for linkage when all families were tested. After stratifying the families according to HLA-DR15 there was weak evidence for linkage to the 19q13.1 subregion in DR15 negative families (LOD(max)=1.8). Taken together these results do not support a major role of chromosome 19q13.2-q13.3 in MS susceptibility among Finnish MS patients, whereas conclusions on the 19q13.1 subregion are less clear and this region requires further study.

HLA class II associated risk and protection against multiple sclerosis-a Finnish family study

We analyzed the HLA class II haplotypes in 249 Finnish nuclear families and compared the frequencies of parental haplotypes transmitted or non-transmitted to multiple sclerosis (MS) patients. The most important predisposing haplotype was DRB1*15-DQB1*0602 (P<10(-6)) as expected and a weak predisposing effect of DRB1*04-DQB1*0302 was revealed after the elimination of DRB1*15-DQB1*0602. HLA-DRB1*01-DQB1*0501 and DRB1*13-DQB1*0603 were negatively associated with MS in transmission disequilibrium test, but only the DRB1*13-DQB1*0603 association remained significant (P=0.008) after the elimination of DRB1*15-DQB1*0602 haplotypes. Based on this study HLA class II haplotypes exhibit both predisposing and protective effects in MS.

Golli-MBP gene in multiple sclerosis susceptibility

Multiple sclerosis (MS) is an oligo- or polygenic disease but no specific susceptibility genes have been identified so far. In the Finnish population we have previously found evidence for linkage between MS and the myelin basic protein gene (here called Golli-MBP gene) suggesting that either Golli-MBP or another gene in its vicinity contributes to MS suceptibility. Here we have screened the Golli-MBP gene for nucleotide variations and carried out multipoint association analyses in a Finnish case-control data-set as well as in an independent data-set composed of 151 MS families from Finland and Sweden. In both data-sets we found association between MS and alleles in the 1.27 kilobase (kb) range at a tetranucleotide repeat element (TGGA)n which is located 1 kb upstream of the MBP exon 1. Haplotype analyses suggested that the MS-associated 1.27 kb alleles can be split into predisposing and non-predisposing variants and provided evidence that the candidate DNA region contributing to MS susceptibility should be located at the Golli-MBP gene within a 20-25 kb segment that was conserved in the predisposing haplotypes. These findings suggest a role for the Golli-MBP locus in MS susceptibility, at least in a subset of patients, and serve as a basis for highly focused attempts to identify predisposing mutation(s).

Genomewide scan of multiple sclerosis in Finnish multiplex families

Multiple sclerosis (MS) is a neurological, demyelinating disorder with a putative autoimmune etiology. It is thought to be a multifactorial disease with a complex mode of inheritance. Here we report the results of a two-stage genomewide scan for loci predisposing to MS. The first stage of the screen, with a low-resolution map, was performed in a selection of 16 pedigrees collected from an isolated Finnish population. Multipoint, non-parametric linkage analysis of the 328 markers did not reveal statistically significant results. However, 10 slightly interesting regions (P = .1-.15) emerged, including our previous findings of the HLA complex on 6p21 and a putative locus on 5p14-p12. Eight of these novel regions were further analyzed by use of denser marker maps, in the second stage of the scan. For the chromosomal regions 4cen, 11tel, and 17q, the statistical significance increased, but not conclusively; for 2q32 and 10q21, the statistical significance did not change. Accordingly, genotyping of the high-density markers in these regions was performed, and the data were analyzed by use of two-point, parametric linkage analysis using the complete pedigree information of the 21 Finnish multiplex families. We detected suggestive evidence for a predisposing locus on chromosomal region 17q22-q24. Several markers on 17q22-q24 yielded positive LOD scores, with the maximum LOD score (Zmax) occurring with D17S807 (Zmax = 2.8, theta = .04; dominant model). Interestingly, a suggestive linkage between MS and the markers on 17q22-q24 was also revealed by a recent genomewide scan in MS families from the United Kingdom.

Immune system genes in multiple sclerosis: genetic association and linkage analyses on TCR beta, IGH, IFN-gamma and IL-1ra/IL-1 beta loci

The role of genetic factors in the etiology of multiple sclerosis (MS) has been clearly demonstrated but the loci determining susceptibility to this disease remain largely unidentified. A contribution from several immune system genes has been suggested based on animal models and association/linkage analyses on MS patients and families. With the exception of the findings from the HLA complex, studies on candidate immune system genes have provided controversial results. Here we have performed genetic association and linkage analyses on four chromosomal regions containing immune system genes. A possible role for each of these loci in MS has been previously suggested. In data-sets derived from the Finnish population we found no evidence for contribution of the T-cell receptor beta chain (TCR beta chromosome 7q35), immunoglobulin heavy chain (IGH chromosome 14q32), interferon-gamma (IFN-gamma chromosome 12q14-q15) or interleukin-1 receptor antagonist/interleukin-1 beta (IL-1ra/IL-1 beta chromosome 2q14-q21) loci in the genetic susceptibility to MS.

A putative vulnerability locus to multiple sclerosis maps to 5p14-p12 in a region syntenic to the murine locus Eae2

Multiple sclerosis (MS) is a chronic inflammatory disorder characterized by multifocal damage of myelin in the central nervous system (CNS). The prevalence of this putative autoimmune disease is 0.1% in individuals of northern European origin. Family, adoption and twin studies implicate genetic factors in the aetiology. MS is widely speculated to be a multifactorial disorder with a complex mode of inheritance. Despite many studies of candidate genes, only an association with HLA-DR2-DQ6 has been generally detected, and the number of susceptibility genes remains unknown. The chronic variant of experimental allergic encephalomyelitis (EAE), a T-cell mediated autoimmune disease in rodents, represents a relevant animal model for MS given the chronic relapsing disease course and inflammatory changes of CNS observed in these demyelinating disorders. Susceptibility to EAE is also influenced by the major histocompatibility complex (MHC). Human syntenic regions to murine loci predisposing to EAE were tested as candidate regions for genetic susceptibility of MS. Three chromosomal regions (1p22-q23, 5p14-p12 and Xq13.2-q22) were screened in 21 Finnish multiplex MS families most originating from a high risk region in western Finland. Several markers yielded positive lod scores on 5p14-p12, syntenic to the murine locus Eae2. Our data provide evidence for a predisposing locus for MS on 5p14-p12.