Methylome analysis in girls with idiopathic central precocious puberty

BACKGROUND

Genetic and environmental factors are implicated in many developmental processes. Recent evidence, however, has suggested that epigenetic changes may also influence the onset of puberty or the susceptibility to a wide range of diseases later in life. The present study aims to investigate changes in genomic DNA methylation profiles associated with pubertal onset analyzing human peripheral blood leukocytes from three different groups of subjects: 19 girls with central precocious puberty (CPP), 14 healthy prepubertal girls matched by age and 13 healthy pubertal girls matched by pubertal stage. For this purpose, the comparisons were performed between pre- and pubertal controls to identify changes in normal pubertal transition and CPP versus pre- and pubertal controls.

RESULTS

Analysis of methylation changes associated with normal pubertal transition identified 1006 differentially methylated CpG sites, 86% of them were found to be hypermethylated in prepubertal controls. Some of these CpG sites reside in genes associated with the age of menarche or transcription factors involved in the process of pubertal development. Analysis of methylome profiles in CPP patients showed 65% and 55% hypomethylated CpG sites compared with prepubertal and pubertal controls, respectively. In addition, interestingly, our results revealed the presence of 43 differentially methylated genes coding for zinc finger (ZNF) proteins. Gene ontology and IPA analysis performed in the three groups studied revealed significant enrichment of them in some pathways related to neuronal communication (semaphorin and gustation pathways), estrogens action, some cancers (particularly breast and ovarian) or metabolism (particularly sirtuin).

CONCLUSIONS

The different methylation profiles of girls with normal and precocious puberty indicate that regulation of the pubertal process in humans is associated with specific epigenetic changes. Differentially methylated genes include ZNF genes that may play a role in developmental control. In addition, our data highlight changes in the methylation status of genes involved in signaling pathways that determine the migration and function of GnRH neurons and the onset of metabolic and neoplastic diseases that may be associated with CPP in later life.

Urinary Incontinence in the Third Trimester of Pregnancy of Type 1 Diabetic Women

BACKGROUND

Type 1 diabetes increases the prevalence of urinary incontinence and may be responsible for additional changes to those existing in a regular gestational period. This study aimed to describe the presence and symptoms of urinary incontinence in pregnant women with type 1 diabetes.

METHODS

In this Cross-sectional case control study, forty pregnant women in third gestational trimester were allocated in two equal groups - control group (CG) and type 1 diabetic group (1DMG). The patients answered the International Consultation on Incontinence Questionnaire Short Form and, to characterize the sample, they answered the Pregnancy Physical Activity Questionnaire, gynecological history and, after delivery, the newborn weight was registered. The groups were compared using the Student's T Test for parametric variables and the U-Mann Whitney Test for non-parametric variables, both at 5% probability.

RESULTS

The International Consultation on Incontinence Questionnaire Short Form score (p = 0.026) is higher in 1DMG (3.95 ± 4.70) compared to CG (1.05 ± 2.23). No correlations were found between time of diagnosis, HbA1c and newborn weight in relation to ICIQ-SF and other variables in CG and 1DMG with ICIQ-SF (p < 0.05).

CONCLUSION

Type 1 diabetes mellitus, in the third trimester of gestation, seem to be associated with increase in the ICIQ-SF score.

Maternal exposure to polystyrene nanoplastics causes defective retinal development and function in progeny mice by disturbing metabolic profiles

Microplastics (MPs) and nanoplastics (NPs) are widely spreading in our living environment, accumulating in the human body and potentially threating human health. The retina, which is a terminally differentiated extension of the central nervous system, is essential for the visual system. However, the effects and molecular mechanisms of MPs/NPs on retina development and function are still unclear. Here, we investigated the effects and modes of action of polystyrene NPs (PS-NPs) on the retina using mice as a mammalian model species. Maternal PS-NP exposure (100 nm) at an environmentally realistic concentration of 10 mg L-1 (or 2.07 *1010 particles mL-1) via drinking water from the first day of pregnancy till the end of lactation (21 days after birth) caused defective neural retinal development in the neonatal mice, by depositing in the retinal tissue and reducing the number of retinal ganglion cells and bipolar cells. Exposure to PS-NPs retarded retinal vascular development, while abnormal electroretinogram (ERG) responses and an increased level of oxidative stress were also observed in the retina of the progeny mice after maternal PS-NP exposure. Metabolomics showed significant dysregulation of amino acids that are pivotal to neuron retinal function, such as glutamate, aspartate, alanine, glycine, serine, threonine, taurine, and serotonin. Transcriptomics identified significantly dysregulated genes, which were enriched in processes of angiogenesis, visual system development and lens development. Regulatory analysis showed that Fos gene mediated pathways could be a potential key target for PS-NP exposure in retinal development and function. Our study revealed that maternal exposure to PS-NPs generated detrimental effects on retinal development and function in progeny mice, offering new insights into the visual toxicity of PS-NPs.

Impact of Endometrial Preparation on the Maternal and Fetal Cardiovascular Variables of the First Trimester Combined Screening Test

The modality of endometrial preparation for the transfer of frozen-thawed embryos may influence maternal and fetal adaptation to pregnancy and could thus impact the results of the first trimester combined screening test. We conducted a retrospective cross-sectional study on singleton pregnancies achieved by embryo transfer of a single frozen-thawed blastocyst, comparing two different endometrial preparation protocols: natural cycle (n = 174) and hormone replacement therapy (HRT) (n = 122). The primary outcome was the risk of preeclampsia at the first trimester combined screening test. Secondary endpoints included variable reflecting fetal cardiac function (nuchal translucency and fetal heart rate), maternal adaptation (median arterial blood pressure-MAP and uterine arteries pulsatility index-UtA-PI), and placentation (pregnancy associated plasma protein A and placental growth factor). The risk of early preeclampsia was comparable in the two groups (38% vs. a 28%, p = 0.12). However, women in the natural cycle group showed lower fetal heart rate (159 [155-164] vs. 164 [158-168], p = 0.002) and higher UtA-PI (0.96 [0.74-1.18] vs. 0.72 [0.58-0.90], p < 0.001). The frequency of a screening test at high risk for aneuploidies was similar. The modality of transfer of frozen-thawed embryos is associated with changes in the variables reflecting maternal and fetal cardiovascular function.

Factors Predisposing to The Formation of Degenerative Spondylolisthesis-A Narrative Review

The relationship between various factors predisposing to the formation of spondylolisthesis, including degenerative spondylolisthesis, has been analyzed by many authors. However, not all observations are consistent. In this review, we identified factors whose impact on the prevalence of spondylolisthesis was most often mentioned in the literature. These included gender, age, bone mineral density, ethnic origin, and oophorectomy. The results were inclusive in terms of physical activity, pregnancy status, and use of hormone replacement therapy. Associations between diabetes and smoking were very poorly marked. The literature so far has identified a number of factors significantly affecting the incidence of degenerative spondylolisthesis. These include age, gender, body weight, ethnic origin, bone mineral density, and hormonal balance. Radiological parameters, which include iliac crest, pelvic tilt, pelvic incidence, sacral slope, and lumbar lordosis, may also be of great importance for assessing changes in the occurrence and progression. However, the authors do not agree on the real significance of individual factors. The aim of this review was to identify the factors predisposing to the formation of degenerative spondylolisthesis, the importance of which has been suggested in the current literature. The systematization of knowledge in this field can allow a more accurate adjustment of the treatment plan for each patient affected by this condition.

Cyclic processes in the uterine tubes, endometrium, myometrium, and cervix: pathways and perturbations

This review leads the 2023 Call for Papers in MHR: 'Cyclical function of the female reproductive tract' and will outline the complex and fascinating changes that take place in the reproductive tract during the menstrual cycle. We will also explore associated reproductive tract abnormalities that impact or are impacted by the menstrual cycle. Between menarche and menopause, women and people who menstruate living in high-income countries can expect to experience ∼450 menstrual cycles. The primary function of the menstrual cycle is to prepare the reproductive system for pregnancy in the event of fertilization. In the absence of pregnancy, ovarian hormone levels fall, triggering the end of the menstrual cycle and onset of menstruation. We have chosen to exclude the ovaries and focus on the other structures that make up the reproductive tract: uterine tubes, endometrium, myometrium, and cervix, which also functionally change in response to fluctuations in ovarian hormone production across the menstrual cycle. This inaugural paper for the 2023 MHR special collection will discuss our current understanding of the normal physiological processes involved in uterine cyclicity (limited specifically to the uterine tubes, endometrium, myometrium, and cervix) in humans, and other mammals where relevant. We will emphasize where knowledge gaps exist and highlight the impact that reproductive tract and uterine cycle perturbations have on health and fertility.

The molecular phenotype of kisspeptin neurons in the medial amygdala of female mice

Reproduction is regulated through the hypothalamic-pituitary-gonadal (HPG) axis, largely via the action of kisspeptin neurons in the hypothalamus. Importantly, Kiss1 neurons have been identified in other brain regions, including the medial amygdala (MeA). Though the MeA is implicated in regulating aspects of both reproductive physiology and behavior, as well as non-reproductive processes, the functional roles of MeA Kiss1 neurons are largely unknown. Additionally, besides their stimulation by estrogen, little is known about how MeA Kiss1 neurons are regulated. Using a RiboTag mouse model in conjunction with RNA-seq, we examined the molecular profile of MeA Kiss1 neurons to identify transcripts that are co-expressed in MeA Kiss1 neurons of female mice and whether these transcripts are modulated by estradiol (E₂) treatment. RNA-seq identified >13,800 gene transcripts co-expressed in female MeA Kiss1 neurons, including genes for neuropeptides and receptors implicated in reproduction, metabolism, and other neuroendocrine functions. Of the >13,800 genes co-expressed in MeA Kiss1 neurons, only 45 genes demonstrated significantly different expression levels due to E₂ treatment. Gene transcripts such as Kiss1, Gal, and Oxtr increased in response to E₂ treatment, while fewer transcripts, such as Esr1 and Cyp26b1, were downregulated by E₂. Dual RNAscope and immunohistochemistry was performed to validate co-expression of MeA Kiss1 with Cck and Cartpt. These results are the first to establish a profile of genes actively expressed by MeA Kiss1 neurons, including a subset of genes regulated by E₂, which provides a useful foundation for future investigations into the regulation and function of MeA Kiss1 neurons.

Effect of changes in the menstrual cycle and age on the signal intensity of amide proton transfer imaging in the normal uterus: a preliminary study

PURPOSE

To analyze the effect of changes in the menstrual cycle and age on the signal intensity of amide proton transfer (APT) imaging in normal uterine structures.

METHODS

Thirty-one healthy females (age: 21-50 years old) underwent regular pelvic MRI and APT sequences during their menstrual cycle. The APT values of the endometrium, myometrium, and junctional zone were measured. One-way and multi-way analyses of variance were used to analyze the data. Intraindividual difference and Pearson's correlation analyses were also conducted.

RESULTS

The APT values of the uterine structures during the menstrual, proliferative, and secretory phases were 3.413 ± 0.682%, 4.776 ± 0.829%, and 5.218 ± 0.772% for the endometrium; 2.966 ± 0.533%, 3.597 ± 0.380%, and 4.324 ± 0.583% for the myometrium; and 1.703 ± 0.393%, 2.362 ± 0.486%, and 2.779 ± 0.528% for the junctional zone. The individual variation in the APT values of the normal uterus during the three menstrual phases was 1.1-1.7%.There were no significant differences in APT values of uterine structures with age. The APT values of the endometrium were greater than those of other structures (P < 0.05).The Pearson correlation coefficients between APT values of uterine structures and menstrual cycle were 0.686, 0.743, and 0.684, respectively.

CONCLUSION

The menstrual cycle had a significant effect on the APT signal intensities of the uterine structures, whereas premenopausal age had no significant effect. Changes in the uterine structures during the menstrual cycle should be considered when using APT to diagnose suspected uterine lesions.

How do pre-pregnancy endometrial macrophages contribute to pregnancy?

Macrophages are professional phagocytes with a wide distribution in all tissues throughout the body. Macrophages play a crucial role in homeostasis and numerous physiological processes beyond innate and adaptive immunity, including cellular debris removal, metabolic regulation, tissue repair, and tissue remodeling. Uterine macrophages are a heterogeneous and highly plastic subset of immune cells regulated by the local microenvironment and, in addition to their anti-inflammatory and anti-infective functions, support the establishment and maintenance of pregnancy. Comprehensive reviews have summarized the role of decidual macrophages during pregnancy. However, the distribution of macrophages in the endometrium prior to pregnancy, their functional remodeling, and the knock-on effects on subsequent pregnancies have not been elucidated. In this review, we focus on 1) how the phenotypes of endometrial macrophages and their interactions with other endometrial cells indicate or contribute to the subsequent pregnancy, 2) the adaptive switching of endometrial macrophages during the initial establishment of pregnancy, 3) and the pregnancy complications and pregnancy-related disorders associated with endometrial macrophages.

The role of angiotensin II and relaxin in vascular adaptation to pregnancy

In brief

There is a pregnancy-induced vasodilation of blood vessels, which is known to have a protective effect on cardiovascular function and can be maintained postpartum. This review outlines the cardiovascular changes that occur in a healthy human and rodent pregnancy, as well as different pathways that are activated by angiotensin II and relaxin that result in blood vessel dilation.

Abstract

During pregnancy, systemic and uteroplacental blood flow increase to ensure an adequate blood supply that carries oxygen and nutrients from the mother to the fetus. This results in changes to the function of the maternal cardiovascular system. There is also a pregnancy-induced vasodilation of blood vessels, which is known to have a protective effect on cardiovascular health/function. Additionally, there is evidence that the effects of maternal vascular vasodilation are maintained post-partum, which may reduce the risk of developing high blood pressure in the next pregnancy and reduce cardiovascular risk later in life. At both non-pregnant and pregnant stages, vascular endothelial cells produce a number of vasodilators and vasoconstrictors, which transduce signals to the contractile vascular smooth muscle cells to control the dilation and constriction of blood vessels. These vascular cells are also targets of other vasoactive factors, including angiotensin II (Ang II) and relaxin. The binding of Ang II to its receptors activates different pathways to regulate the blood vessel vasoconstriction/vasodilation, and relaxin can interact with some of these pathways to induce vasodilation. Based on the available literature, this review outlines the cardiovascular changes that occur in a healthy human pregnancy, supplemented by studies in rodents. A specific focus is placed on vasodilation of blood vessels during pregnancy; the role of endothelial cells and endothelium-derived vasodilators will also be discussed. Additionally, different pathways that are activated by Ang II and relaxin that result in blood vessel dilation will also be reviewed.

Decidualization of endometriosis in a cohort of IVF-mediated pregnancies

Decidualization is the process of endometrial change in pregnancy, a phenomenon that can involve also ovarian endometriomas. However, the frequency of this event remains unknown. In addition, there is no evidence on the decidualization of deep invasive endometriosis (DIE). To shed more light on this issue, we prospectively recruited women with ovarian endometriomas or DIE who underwent IVF. They were subsequently excluded if they did not become pregnant or if they had a miscarriage. The evaluation was repeated in five time points during pregnancy and post-partum. The primary outcome was the rate of decidualized endometriomas at 11-13 weeks' gestation. Data from 45 endometriomas and 15 nodules were available for data analyses. At the 11-13 weeks' ultrasound, endometriomas' decidualization was observed in seven cases, corresponding to 16% (95% CI 8-29%). Subsequent assessments in pregnancy failed to identify any additional case. DIE also underwent significant changes during pregnancy. At the 11-13 weeks' ultrasound, lesions were increased in size and more vascularized. In conclusion, decidualization of ovarian endometriomas in IVF pregnancies is not rare. DIE may also undergo decidualization, but further evidence is needed for a robust and shared definition of this process.

TULUA Male High-Definition Abdominoplasty

BACKGROUND

Abdominoplasty is a surgical technique for body contouring that has been shown to improve the patient's quality of life. It has become more common among male patients, so clear differences between procedures for men and women have to be stated. The authors present their experience with high-definition lipoabdominoplasty with transverse plication in men.

METHODS

Records of male patients undergoing transverse plication full abdominoplasty in addition to high-definition liposculpture were analyzed. A total of 24 consecutive cases were found between January of 2017 and June of 2019. Patient ages ranged from 24 to 60 years. Patients aged 18 years or younger were excluded. Body mass index ranged from 25 to 33 kg/m2. Photographic records were taken before and during follow-up at 2 days and 1, 3, 6, and 12 months after surgery.

RESULTS

Male TULUA (transverse plication, no undermining, full liposuction, neoumbilicoplasty, and low transverse abdominal scar) with high-definition lipoabdominoplasty was successfully achieved in 24 cases. No major complications were reported. Six minor complications were reported (25 percent). Rectus abdominis diastases are less common in men compared to women, as pregnancy is the most determining factor in its development. Fat distribution is also a key difference when performing lipoabdominoplasty for the male or the female patient. The authors recommend a transverse plication of the abdominal wall, instead of a vertical one, as flap viability is preserved and enhanced muscular definition can be accomplished.

CONCLUSIONS

Combining transverse plication with high-definition lipoabdominoplasty (transverse plication, no undermining, full liposuction, neoumbilicoplasty, and low transverse abdominal scar plus high-definition lipoabdominoplasty) is a safe and reproducible technique for the male patient. It offers higher aesthetic results in line with modern beauty ideals.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Pregnancy Outcomes After Frozen-Thawed Embryo Transfer in the Absence of a Corpus Luteum

Background: Nowadays, frozen-thawed embryo transfer (FET) cycles represent a high proportion of fertility treatments worldwide. Recent studies suggest differences in pregnancy outcomes depending on the FET treatment protocol used. The reason for this is still unclear, but the number of corpora lutea (CL) at conception is discussed as a possible factor. This study aims to investigate whether maternal and neonatal outcomes for pregnancies following FET lacking a CL differ from FET with one or more CL in order to explore a potential link between CL absence and adverse pregnancy outcomes.

Methods: The study was designed as a retrospective, multi-center observational study with two cohorts after singleton live birth [0 CL cohort (FET in a programmed cycle, n = 114) and ≥ 1 CL cohort (FET in a natural or stimulated cycle, n = 68)]. Participants completed a questionnaire on the outcome of pregnancy and birth records were analyzed in a descriptive way. Multivariable logistic and linear regressions were performed in order to explore associations between CL absence and pregnancy outcomes. The strength of the agreement between the information in the survey and the diagnoses extracted from the files was assessed by Cohen's Kappa.

Results: The risk of hypertensive disorders of pregnancy was higher after FET in the absence of a CL compared to FET with CL presence (aOR 5.56, 95% CI 1.12 – 27.72). Birthweights and birthweight percentiles were significantly higher in the 0 CL group. CL absence was a predictor of higher birthweight (adjusted coefficient B 179.74, 95% CI 13.03 – 346.44) and higher birthweight percentiles (adjusted coefficient B 10.23, 95%, 95% CI 2.28 – 18.40) particularly in female newborns of the 0 CL cohort. While the strength of the agreement between the reported information in the survey and the actual diagnoses extracted from the files was good for the majority of outcomes of interest it was fair in terms of hypertension (κ = 0.38).

Conclusion: This study supports observations suggesting a potential link between a lack of CL at conception and adverse maternal and neonatal outcomes. Further investigations on causes and pathophysiological relationships are yet to be conducted.

Association of Self-Reported Physical Fitness during Late Pregnancy with Birth Outcomes and Oxytocin Administration during Labour-The GESTAFIT Project

We explored (a) the associations between self-reported maternal physical fitness and birth outcomes; (b) whether self-reported maternal physical fitness (PF) is related to the administration of oxytocin to induce or stimulate labour. Pregnant women from the GESTAFIT project randomized controlled trial (n = 117) participated in this prospective longitudinal study. Maternal physical fitness was assessed through the International Fitness Scale at the 34th gestational week. Maternal and neonatal birth outcomes and oxytocin administration were collected from the obstetric medical records. Umbilical arterial and venous cord blood gas were analysed immediately after birth. Self-reported overall fitness, cardiorespiratory fitness, muscular strength and flexibility were not related to any maternal and neonatal birth outcomes (all p > 0.05). Greater speed-agility was associated with a more alkaline arterial (p = 0.04) and venous (p = 0.02) pH in the umbilical cord blood. Women who were administered oxytocin to induce or stimulate labour reported lower cardiorespiratory fitness (p = 0.013, Cohen's d = 0.55; 95% confidence interval (CI): 0.14, 0.93) and flexibility (p = 0.040, Cohen´s d = 0.51; 95% CI: 0.09, 0.89) compared to women who were not administered oxytocin. Greater maternal physical fitness during pregnancy could be associated with better neonatal birth outcomes and lower risk of needing oxytocin administration.

Circulating transcripts in maternal blood reflect a molecular signature of early-onset preeclampsia

Circulating RNA (C-RNA) is continually released into the bloodstream from tissues throughout the body, offering an opportunity to noninvasively monitor all aspects of pregnancy health from conception to birth. We asked whether C-RNA analysis could robustly detect aberrations in patients diagnosed with preeclampsia (PE), a prevalent and potentially fatal pregnancy complication. As an initial examination, we sequenced the circulating transcriptome from 40 pregnancies at the time of severe, early-onset PE diagnosis and 73 gestational age-matched controls. Differential expression analysis identified 30 transcripts with gene ontology annotations and tissue expression patterns consistent with the placental dysfunction, impaired fetal development, and maternal immune and cardiovascular system dysregulation characteristic of PE. Furthermore, machine learning identified combinations of 49 C-RNA transcripts that classified an independent cohort of patients (early-onset PE, n = 12; control, n = 12) with 85 to 89% accuracy. C-RNA may thus hold promise for improving the diagnosis and identification of at-risk pregnancies.

Secretory products of the corpus luteum and preeclampsia

BACKGROUND

Despite significant advances in our understanding of the pathophysiology of preeclampsia (PE), there are still many unknowns and controversies in the field. Women undergoing frozen-thawed embryo transfer (FET) to a hormonally prepared endometrium have been found to have an unexpected increased risk of PE compared to women who receive embryos in a natural FET cycle. The differences in risk have been hypothesized to be related to the absence or presence of a functioning corpus luteum (CL).

OBJECTIVE AND RATIONALE

To evaluate the literature on secretory products of the CL that could be essential for a healthy pregnancy and could reduce the risk of PE in the setting of FET.

SEARCH METHODS

For this review, pertinent studies were searched in PubMed/Medline (updated June 2020) using common keywords applied in the field of assisted reproductive technologies, CL physiology and preeclampsia. We also screened the complete list of references in recent publications in English (both animal and human studies) on the topics investigated. Given the design of this work as a narrative review, no formal criteria for study selection or appraisal were utilized.

OUTCOMES

The CL is a major source of multiple factors regulating reproduction. Progesterone, estradiol, relaxin and vasoactive and angiogenic substances produced by the CL have important roles in regulating its functional lifespan and are also secreted into the circulation to act remotely during early stages of pregnancy. Beyond the known actions of progesterone and estradiol on the uterus in early pregnancy, their metabolites have angiogenic properties that may optimize implantation and placentation. Serum levels of relaxin are almost undetectable in pregnant women without a CL, which precludes some maternal cardiovascular and renal adaptations to early pregnancy. We suggest that an imbalance in steroid hormones and their metabolites and polypeptides influencing early physiologic processes such as decidualization, implantation, angiogenesis and maternal haemodynamics could contribute to the increased PE risk among women undergoing programmed FET cycles.

WIDER IMPLICATIONS

A better understanding of the critical roles of the secretory products of the CL during early pregnancy holds the promise of improving the efficacy and safety of ART based on programmed FET cycles.

Relaxin and the Cardiovascular System: from Basic Science to Clinical Practice

The peptide hormone relaxin was originally linked to reproductive physiology, where it is believed to mediate systemic and renal hemodynamic adjustments to pregnancy. Recently, its broad range of effects in the cardiovascular system has been the focus of intensive research regarding its implications under pathological conditions and potential therapeutic potential. An understanding of the multitude of cardioprotective actions prompted the study of serelaxin, recombinant human relaxin-2, for the treatment of acute heart failure. Despite early promising results from phase II studies, recently revealed RELAX-AHF-2 outcomes were rather disappointing and the treatment for acute heart failure remains an unmet medical need. This article reviews the physiologic actions of relaxin on the cardiovascular system and its relevance in the pathophysiology of cardiovascular disease. We summarize the most updated clinical data and discuss future directions of serelaxin for the treatment of acute heart failure. This should encourage additional work to determine how can relaxin's beneficial effects be exploited for the treatment of cardiovascular disease.

Uterine Vascular Control Preconception and During Pregnancy

Successful pregnancy and reproduction are dependent on adequate uterine blood flow, placental perfusion, and vascular responsivity to fetal demands. The ability to support pregnancy centers on systemic adaptation and endometrial preparation through decidualization, embryonic implantation, trophoblast invasion, arterial/arteriolar reactivity, and vascular remodeling. These adaptations occur through responsiveness to endocrine signaling and local uteroplacental mediators. The purpose of this article is to highlight the current knowledge associated with vascular remodeling and responsivity during uterine preparation for and during pregnancy. We focus on maternal cardiovascular systemic and uterine modifications, endometrial decidualization, implantation and invasion, uterine and spiral artery remodeling, local uterine regulatory mechanisms, placentation, and pathological consequences of vascular dysfunction during pregnancy. © 2021 American Physiological Society. Compr Physiol 11:1-23, 2021.

Frozen Embryo Transfer and Preeclampsia Risk

Worldwide, the use of Assisted Reproductive Technology (ART) has been steadily rising over recent years. With the continuous improvements in cryopreservation techniques and the growing practice of single embryo transfer, the proportion of frozen embryo transfer (FET) cycles has been increasing, therefore raising concern about the safety of this ART technique to both mothers and infants. This review aims to summarize the current evidence regarding the risk of preeclampsia in singleton pregnancies achieved by autologous FET compared to fresh embryo transfer, and to discuss the influence of different protocols used for endometrium preparation in frozen cycles on the risk of this obstetric complication. Several studies have reported a higher risk of hypertensive disorders, including preeclampsia, in pregnancies following FET compared with fresh embryo transfer. Recently, artificial FET cycles, which preclude the development of a corpus luteum, were shown to be associated with an increased preeclampsia risk in comparison with natural and stimulated cycles. Importantly, no difference was found between FET in a modified natural cycle and spontaneous conception. It has been proposed that the absence of the corpus luteum in artificial cycles may, at least partly, contribute to the observed increased risk of preeclampsia. Indeed, the corpus luteum secretes vasoactive hormones, such as relaxin, which are not replaced in artificial cycles, thereby compromising maternal cardiovascular adaptations to pregnancy, resulting in an increased risk of preeclampsia. If these findings are confirmed by a randomized controlled trial, natural, modified natural or stimulated cycles might be preferred over artificial cycles in eligible patients.

Role of arterial impairment in preeclampsia: should the paradigm shift?

Preeclampsia is a worldwide pregnancy complication with serious short- and long-term maternal and neonatal consequences. Our understanding of preeclampsia pathophysiology has significantly evolved over the last decades with the recognition that impaired arterial function and structure may occur early in the course of pregnancy, preceding the clinic-humoral syndrome and driving long-term cardiovascular disease risk in the future of these patients. Although an early abnormal placentation may be the inciting event for a large proportion of cases, there is growing evidence that challenges the placental hypothesis in all affected women, since placental histopathology lesions thought to be characteristic are neither sensitive nor specific markers for the disorder. Recent hemodynamic investigations and studies on left ventricular function and structure in women with preeclampsia further challenge this universal paradigm and propose that placental dysfunction could be secondary to a maternal cardiovascular maladaptation to pregnancy in certain patients. Supporting this hypothesis, certain vascular features, which are characteristically enhanced in normal pregnancy allowing a healthy vascular adaptation, are absent in preeclampsia and comparable to the nonpregnant population. However, arterial biomechanics in preeclampsia may only not cope with hemodynamic demands of pregnancy but also impose additional detrimental loads to the maternal heart ("impaired left-ventricle-aorta coupling") and transmit pressure and flow disturbances into the fetoplacental circulation ("impaired large arteries-microcirculation coupling"). In this review, we analyze the major role of the arterial dysfunction in the cardiovascular maladaptation hypothesis of preeclampsia, shed light on its potential etiopathogenic link, and discuss the complementary nature of the placental and cardiovascular theories.

Inhibition of relaxin autocrine signaling confers therapeutic vulnerability in ovarian cancer

Ovarian cancer (OC) is the most deadly gynecological malignancy, with unmet clinical need for new therapeutic approaches. The relaxin peptide is a pleiotropic hormone with reproductive functions in the ovary. Relaxin induces cell growth in several types of cancer, but the role of relaxin in OC is poorly understood. Here, using cell lines and xenograft models, we demonstrate that relaxin and its associated GPCR RXFP1 form an autocrine signaling loop essential for OC in vivo tumorigenesis, cell proliferation, and viability. We determined that relaxin signaling activates expression of prooncogenic pathways, including RHO, MAPK, Wnt, and Notch. We found that relaxin is detectable in patient-derived OC tumors, ascites, and serum. Further, inflammatory cytokines IL-6 and TNF-α activated transcription of relaxin via recruitment of STAT3 and NF-κB to the proximal promoter, initiating an autocrine feedback loop that potentiated expression. Inhibition of RXFP1 or relaxin increased cisplatin sensitivity of OC cell lines and abrogated in vivo tumor formation. Finally, we demonstrate that a relaxin-neutralizing antibody reduced OC cell viability and sensitized cells to cisplatin. Collectively, these data identify the relaxin/RXFP1 autocrine loop as a therapeutic vulnerability in OC.

Greater fetal crown-rump length growth with the use of in vitro fertilization or intracytoplasmic sperm injection conceptions after thawed versus fresh blastocyst transfers: secondary analysis of a prospective cohort study

OBJECTIVE

To compare first-trimester fetal crown-rump length (CRL) measurements in pregnancies obtained after thawed blastocyst transfer versus fresh blastocyst transfer after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

DESIGN

Prospective longitudinal cohort study of CRL Z scores with adjustment for major confounders.

SETTING

University-affiliated obstetrics, fetal medicine, and fertility units.

PATIENT(S)

Singleton gestations conceived via IVF/ICSI and fresh or thawed blastocyst transfer with ultrasound performed at 6-14 weeks of gestational age.

INTEVENTION

None.

MAIN OUTCOME MEASURE(S)

CRL Z scores.

RESULT(S)

A total of 365 IVF/ICSI pregnancies were recruited (fresh: 161; thawed: 204). The mean CRL Z score at 6-14 weeks was significantly greater in thawed versus fresh transfers. Different growth trajectories between thawed and fresh transfers were detected: Mean CRL Z score was 0 at 65 days in fresh versus 80 days in frozen. Comparisons of both fresh and thawed transfers with reference values from the general population confirmed significantly lower CRL Z scores in both IVF/ICSI groups (P<.001). The risks of CRL <5th percentile in fresh versus thawed were, respectively 68% vs. 40% at 6 weeks and 2% vs. 1% at 14 weeks. A significant positive correlation between CRL Z scores and birth weight Z scores was found only for fresh transfers, not for thawed.

CONCLUSION(S)

At 6-14 weeks, thawed blastocyst transfers after IVF/ICSI conceptions present greater CRLs compared with fresh, and both IVF/ICSI groups show smaller CRLs than the general population. This effect is particularly evident before 9 weeks and it may favor birth weight difference of thawed versus fresh BT pregnancies.

Ocular Phenotype of Relaxin Gene Knockout (Rln-/-) Mice

Purpose: To test if relaxin deficiency affects ocular structure and function we investigated expression of relaxin (Rln) and RXFP receptors (Rxfp1, Rxfp2), and compared ocular phenotypes in relaxin gene knockout (Rln^-/- ) and wild type (Rln^+/+ ) mice. Materials and Methods: Rln, Rxfp1 and Rxfp2 mRNA expression was detected in ocular tissues of Rln+/+ mice using RT-PCR. The eyes of 11 Rln^-/- and 5 Rln^+/+ male mice were investigated. Corneal and retinal thickness was assessed using optical coherence tomography. Intraocular pressure was measured using a rebound tonometer. Retinal, choroidal and sclera morphology and thickness were evaluated histologically. Eyes were collected and fixed for immunofluorescence staining or used for RNA extraction to evaluate mRNA expression using real-time PCR. Results: Rln mRNA was expressed only in the retina, whereas Rxfp1 transcripts were detected in the retina, cornea and sclera/choroid. Rxfp2 was only present in the cornea. None of these genes were expressed in the lacrimal gland, eyelid or lens. Intraocular pressure was higher and central cornea of Rln^-/- mice was significantly thicker and had significantly larger endothelial cells and a lower endothelial cell density than Rln^+/+ mice. Immunohistochemistry demonstrated no significant difference in AQP3 and AQP5 staining in the cornea or other regions between wildtype and Rln^-/- mice. mRNA expression of Aqp4 was significantly higher in Rln^-/- than in Rln^+/+ corneas, whereas Col1a2, Mmp9, Timp1 and Timp2 were significantly decreased. Expression of Aqp1, Aqp4, Aqp5, Vim and Tjp1 was significantly decreased in Rln^-/- compared to Rln^+/+ uvea. No significant differences in these genes were detected in the retina. Retinal, choroidal and scleral thicknesses were not different and morphology appeared normal. Conclusion: The findings indicate that loss of Rln affects expression of several genes in the uvea and cornea and results in thicker corneas with altered endothelial cells. Many of the gene changes suggest alterations in extracellular matrix and fluid transport between cells.

Serum relaxin and cervical length for prediction of spontaneous preterm birth in second-trimester symptomatic women

OBJECTIVE

To investigate whether serum relaxin level is associated with preterm birth in symptomatic women, either as a standalone test or in the context of a combined model of serum relaxin and cervical length (CL).

METHODS

This was a case-control study of women with a singleton pregnancy who presented between 24 + 0 and 26 + 6 weeks' gestation with threatened preterm labor and intact membranes. CL, full blood count, C-reactive protein level and maternal demographics were recorded at presentation, and blood samples were taken for relaxin measurement. Parameters were compared between women who delivered preterm (before 37 weeks) (n = 46) and those delivering at term (n = 66). Logistic regression with receiver-operating characteristics (ROC) curve analysis was used to assess significant predictors for birth before 37 and before 34 weeks.

RESULTS

Women delivering before 37 weeks had higher mean serum relaxin levels and lower mean CL than those delivering at term (P < 0.0001). Relaxin alone had 63% (95% CI, 49-75%) sensitivity for birth before 37 weeks and 61% (95% CI, 47-74%) for birth before 34 weeks, at a 10% false-positive rate (FPR). Serum relaxin levels did not correlate with CL; a combined model of the two predictors had an area under the ROC curve of 0.895 (95%CI, 0.835-0.954) for the prediction of birth before 37 weeks and 0.869 (95% CI, 0.802-0.937) for birth before 34 weeks (n =  44). Serum relaxin > 1010 pg/mL had 58% sensitivity for prediction of preterm birth in women with a CL > 15 mm, at a 10% FPR.

CONCLUSIONS

High serum relaxin level is associated with an increased risk of preterm birth in second-trimester symptomatic women with intact membranes. A combination of serum relaxin and CL increases predictive accuracy for preterm birth. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Relaxin 2/RXFP1 Signaling Induces Cell Invasion via the β-Catenin Pathway in Endometrial Cancer

Relaxin is known to play an important role in animal pregnancies, including those of humans. It is suggested that relaxin induces aggressive cell growth and invasiveness in several types of cancer, including endometrial cancer. However, the mechanisms of relaxin remain largely unclear. In this study, we examined the effects of relaxin 2 (RLN2), the major circulating relaxin in humans, on human endometrial carcinoma cell lines. RLN2 treatment induced invasion in HEC-1B and Ishikawa cells. RLN2-induced cell invasion was significantly decreased by transfection of relaxin receptor 1 (RXFP1) siRNAs. The β-catenin inhibitor, XAV939, also significantly inhibited the RLN2-induced cell invasions. Both a decrease of cadherin expression and an increase of β-catenin phosphorylation were observed in response to the RLN2 treatment in HEC-1B and Ishikawa cells. We then examined RLN2 and RXFP1 expression in 80 human endometrioid endometrial carcinoma tissues. RLN2 immunoreactivity was detected in the human endometrial carcinoma cells and had a correlative tendency with histological grade and RXFP1. These results suggest that adherens junctions in cancer cells are weakened by the breakdown of the cadherin/catenin complex, which is induced by β-catenin phosphorylation via RLN2/RXFP1 signaling.

Synthetic non-peptide low molecular weight agonists of the relaxin receptor 1

Relaxin is a small heterodimeric peptide hormone of the insulin/relaxin superfamily produced mainly in female and male reproductive organs. It has potent antifibrotic, vasodilatory and angiogenic effects and regulates the normal function of various physiological systems. Preclinical studies and recent clinical trials have shown the promise of recombinant relaxin as a therapeutic agent in the treatment of cardiovascular and fibrotic diseases. However, there are the universal drawbacks of peptide-based pharmacology that apply to relaxin: a short half-life in vivo requires its continuous delivery, and there are high costs of production, storage and treatment, as well as the possibility of immune responses. All these issues can be resolved by the development of low non-peptide MW agonists of the relaxin receptors which are stable, bioavailable, easily synthesized and specific. In this review, we describe the discovery and characterization of the first series of such compounds. The lead compound, ML290, binds to an allosteric site of the relaxin GPCR, RXFP1. ML290 shows high activity and efficacy, measured by cAMP response, in cells expressing endogenous or transfected RXFP1. Relaxin-like effects of ML290 were shown in various functional cellular assays in vitro. ML290 has excellent absorption, distribution, metabolism and excretion properties and in vivo stability. The identified series of low MW agonists does not activate rodent RXFP1 receptors and thus, the production of a RXFP1 humanized mouse model is needed for preclinical studies. The future analysis and clinical perspectives of relaxin receptor agonists are discussed.

LINKED ARTICLES

This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc.