Little is known about the involvement of microRNAs (miRNAs) in the follicular-luteal transition. The aim of this study was to identify genome-wide changes in miRNAs associated with follicular differentiation in sheep. miRNA libraries were produced from samples collected at defined stages of the ovine oestrous cycle and representing healthy growing follicles, (diameter, 4.0-5.5 mm), pre-ovulatory follicles (6.0-7.0 mm), early corpora lutea (day 3 post-oestrus) and late corpora lutea (day 9). A total of 189 miRNAs reported in sheep or other species and an additional 23 novel miRNAs were identified by sequencing these libraries. miR-21, miR-125b, let-7a and let-7b were the most abundant miRNAs overall, accounting for 40% of all miRNAs sequenced. Examination of changes in cloning frequencies across development identified nine different miRNAs whose expression decreased in association with the follicular-luteal transition and eight miRNAs whose expression increased during this transition. Expression profiles were confirmed by northern analyses, and experimentally validated targets were identified using miRTarBase. A majority of the 29 targets identified represented genes known to be actively involved in regulating follicular differentiation in vivo. Finally, luteinisation of follicular cells in vitro resulted in changes in miRNA levels that were consistent with those identified in vivo, and these changes were temporally associated with changes in the levels of putative miRNA targets in granulosa cells. In conclusion, this is the first study to characterise genome-wide miRNA profiles during different stages of follicle and luteal development. Our data identify a subset of miRNAs that are potentially important regulators of the follicular-luteal transition. Reproduction (2012) 144 221-233
The increasing utilization of a gonadotropin-releasing hormone agonist ovulation trigger and the widespread use of artificial cycles for the transfer of frozen–thawed or donated embryos has renewed interest in the luteal phase in assisted reproductive technology. The “luteal phase defect” phenomenon is now understood as a continuum: there is less impairment with milder stimulation than with more intense ovarian stimulation, and less impairment after controlled ovarian stimulation and human chorionic gonadotropin ovulation triggering than after gonadotropin-releasing hormone agonist ovulation triggering, the latter being associated with rapid luteolysis. The intensity of the support of luteal phase necessary to achieve optimal outcomes therefore depends on the degree of luteal phase defect encountered in different treatment protocols. Ultimately, the luteal phase of an artificial cycle in which ovulation is suppressed, a corpus luteum is therefore absent, and the establishment of endometrial receptivity completely relies on the orchestrated exogenous administration of sex steroids, is the litmus test situation for the study of the efficacy of different luteal phase support preparations, doses, regimens, and routes of administration.
Luteal phase deficiency (LPD) has been described in healthy normally menstruating women and in association with other medical conditions. While progesterone is important for the process of implantation and early embryonic development, LPD, as an independent entity causing infertility, has not been proven.
The variable infectivity and transmissibility of HIV/SHIV has been recently associated with the menstrual cycle, with particular susceptibility observed during the luteal phase in nonhuman primate models and ex vivo human explant cultures, but the mechanism is poorly understood. Here, we performed an unbiased, mass spectrometry-based proteomic analysis to better understand the mucosal immunological processes underpinning this observed susceptibility to HIV infection. Cervicovaginal lavage samples (n = 19) were collected, characterized as follicular or luteal phase using days since last menstrual period, and analyzed by tandem mass spectrometry. Biological insights from these data were gained using a spectrum of computational methods, including hierarchical clustering, pathway analysis, gene set enrichment analysis, and partial least-squares discriminant analysis with LASSO feature selection. Of the 384 proteins identified, 43 were differentially abundant between phases (P = 2-fold change). Cell-cell adhesion proteins and anti-proteases were reduced, and leukocyte recruitment (interleukin-8 pathway, P = 1.41E-5) and extravasation proteins (P = 5.62E-4) were elevated during the luteal phase. LASSO/PLSDA identified a minimal profile of 18 proteins that best distinguished the luteal phase. This profile included cytoskeletal elements and proteases known to be involved in cellular movement. Gene set enrichment analysis associated CD4(+) T cell and neutrophil gene set signatures with the luteal phase (P< 0.05). Taken together, our findings indicate a strong association between proteins involved in tissue remodeling and leukocyte infiltration with the luteal phase, which may represent potential hormone-associated mechanisms of increased susceptibility to HIV. IMPORTANCE Recent studies have discovered an enhanced susceptibility to HIV infection during the progesterone-dominant luteal phase of the menstrual cycle. However, the mechanism responsible for this enhanced susceptibility has not yet been determined. Understanding the source of this vulnerability will be important for designing efficacious HIV prevention technologies for women. Furthermore, these findings may also be extrapolated to better understand the impact of exogenous hormone application, such as the use of hormonal contraceptives, on HIV acquisition risk. Hormonal contraceptives are the most widely used contraceptive method in sub-Saharan Africa, the most HIV-burdened area of the world. For this reason, research conducted to better understand how hormones impact host immunity and susceptibility factors important for HIV infection is a global health priority.
Objective To assess live-birth defects after a luteal-phase ovarian-stimulation regimen (LPS) for in vitro fertilization (IVF) and vitrified embryo transfer (ET) cycles. Design Retrospective cohort study. Setting Tertiary-care academic medical center. Patient(s) Infants who were born between January 1, 2013 and May 1, 2014 from IVF with intracytoplasmic sperm injection (ICSI) treatments (n = 2,060) after either LPS (n = 587), the standard gonadotropin-releasing hormone–agonist (GnRH-a) short protocol (n = 1,257), or mild ovarian stimulation (n = 216). Intervention(s) The three ovarian-stimulation protocols described and assisted reproductive technology (ART) treatment (IVF or ICSI, and vitrified ET) in ordinary practice. Main Outcome Measure(s) The main measures were: gestational age, birth weight and length, multiple delivery, early neonatal mortality, and birth defects. Associations were assessed using logistic regression by adjusting for confounding factors. Result(s) The final sample included 2,060 live-born infants, corresponding to 1,622 frozen–thawed (FET) cycles, which led to: 587 live-born infants from LPS (458 FET cycles); 1,257 live-born infants from the short protocol (984 FET cycles); and 216 live-born infants from mild ovarian stimulation (180 FET cycles). Birth characteristics regarding gestational age, birth weight and length, multiple delivery, and early neonatal death were comparable in all groups. The incidence of live-birth defects among the LPS group (1.02%) and the short GnRH-a protocol group (0.64%) was slightly higher than in the mild ovarian-stimulation group (0.46%). However, none of these differences reached statistical significance. For congenital malformations, the risk significantly increased for the infertility-duration factor and multiple births; the adjusted odds ratios were 1.161 (95% confidence interval [CI]: 1.009–1.335) and 3.899 (95% CI: 1.179–12.896), respectively. No associations were found between congenital birth defects and various ovarian-stimulation regimens, maternal age, body mass index, parity, insemination method, or infant gender. Conclusion(s) To date, the data do not indicate an elevated rate of abnormality at birth after LPS, but further study with larger populations is needed to confirm these results. However, infertility itself poses a risk factor for congenital malformation. A higher likelihood of birth defects in multiple births may lead couples to favor elective, single ET; couples undertaking ART should be made aware of the known increased birth defects associated with a twin birth.
Objective To compare the safety, efficacy, and tolerability of subcutaneous progesterone (Prolutex, 25 mg; IBSA Institut Biochimique SA) with vaginal progesterone gel (Crinone, 8%; Merck Serono) for luteal phase support (LPS) in assisted reproduction technologies (ART) patients. Design Prospective, open-label, randomized, controlled, parallel-group, multicenter, two-arm, noninferiority study. Setting Thirteen European fertility clinics. Patient(s) A total of 683 ART patients randomized to two groups: Prolutex, 25 mg subcutaneously daily (n = 339); and Crinone, 90 mg 8% gel daily (n = 344). Intervention(s) In vitro fertilization and embryo transfer were performed according to site-specific protocols. On the day of oocyte retrieval, Prolutex or Crinone gel was begun for LPS and continued for up to 10 weeks. Main Outcome Measure(s) Ongoing pregnancy rate. Result(s) The primary end point, ongoing pregnancy rates at 10 weeks of treatment were 27.4% and 30.5% in the Prolutex and Crinone groups, respectively (intention to treat [ITT]). The nonsignificant difference between the groups was −3.09% (95% confidence interval [CI] −9.91–3.73), indicating noninferiority of Prolutex to Crinone. Delivery and live birth rates resulted to be equivalent between the two treatments (26.8% vs. 29.9% in the Prolutex and Crinone groups, respectively [ITT]; difference −3.10 [95% CI −9.87–3.68]). No statistically significant differences were reported for any of the other secondary efficacy endpoints, including comfort of usage and overall satisfaction. Conclusion(s) Implantation rate, pregnancy rate, live birth rate, and early miscarriage rate for Prolutex were similar to those for Crinone. The adverse event profiles were similar and Prolutex was safe and well tolerated. Clinical Trial Registration Number NCT00827983.
Background: Reproductive success depends on a functional oviduct for gamete storage, maturation, fertilization, and early embryonic development. The ovarian-derived steroids estrogen and progesterone are key regulators of oviductal function. The objective of this study was to investigate luteal and follicular phase-specific oviductal epithelial cell function by using microarray-based transcriptional profiling, to increase our understanding of mRNAs regulating epithelial cell processes, and to identify novel genes and biochemical pathways that may be found to affect fertility in the future. Methods: Six normally cycling Angus heifers were assigned to either luteal phase (LP, n = 3) or follicular phase (FP, n = 3) treatment groups. Heifers in the LP group were killed between day 11 and 12 after estrus. Heifers in the FP group were treated with 25 mg PGF(2 alpha) (Lutalyse, Pfizer, NY) at 8 pm on day 6 after estrus and killed 36 h later. Transcriptional profiling by microarray and confirmation of selected mRNAs by real-time RT-PCR analyses was performed using total RNA from epithelial cells isolated from sections of the ampulla and isthmus collected from LP and FP treatment groups. Differentially expressed genes were subjected to gene ontology classification and bioinformatic pathway analyses. Results: Statistical one-way ANOVA using Benjamini-hochberg multiple testing correction for false discovery rate (FDR) and pairwise comparison of epithelial cells in the ampulla of FP versus LP groups revealed 972 and 597 transcripts up- and down-regulated, respectively (P < 0.05). Within epithelial cells of the isthmus in FP versus LP groups, 946 and 817 transcripts were up-and down-regulated, respectively (P < 0.05). Up-regulated genes from both ampulla and isthmus were found to be largely involved in cholesterol biosynthesis and cell cycle pathways, while down-regulated genes were found in numerous inflammatory response pathways. Conclusions: Microarray-based transcriptional profiling revealed phase of the cycle-dependent changes in the expression of mRNA within the epithelium of the oviducts' ampulla and isthmus.
The term ‘luteal phase deficiency’ was first coined more than 60 years ago, and, since then, it has been suggested as a clinical entity per se and an aetiological factor for subfertility, implantation failure and recurrent miscarriage. Despite the existing recommendations for rational work‐up in subfertility, luteal phase evaluation and progesterone therapy alone is still common in daily practice. This review comprises results from a Pubmed literature search with the terms ‘luteal phase’ and ‘subfertility’, focussing on clinical situations not primarily related to assisted reproduction techniques. Additional data from the experimental studies published in the past 10 years on follicular maturation, oocyte developmental competence and the ovulatory cascade are integrated into the clinical continuum of dysfunctional ovulation, menstrual cycle irregularity and impaired corpus luteum function. As reliable diagnostic tools for adequate luteal function are missing, the presence of clinical symptoms such as cycle irregularity or premenstrual spotting is indicative and should initiate early follicular phase diagnostic work‐up. New evidence on the interdependence of oocyte and follicular maturation and resulting developmental competence of the embryo further support the use of ovarian stimulation as the first‐line therapeutic option in different subsets of patients with subfertility including luteal phase deficiency.
Highlights • Women with sharp decline in luteal phase progesterone developed premenstrual symptoms • Women with gradual decline in luteal phase progesterone had no premenstrual dysphoria • Rate of progesterone metabolism linked to development of premenstrual dysphorias
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.