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.

Catechol-O-methyltransferase and Pregnancy Outcome: an Appraisal in Rat

Catechol-O-methyltransferase (COMT) has been shown to be a key regulator of pregnancy outcomes in mouse, and its deficiency is causative in the development of a preeclampsia-like disease process. Preeclampsia is a human pregnancy disorder associated with failure of intrauterine trophoblast cell invasion and trophoblast-guided uterine spiral artery remodeling, which are not well-developed in mouse. The purpose of this study was to investigate COMT in rat, a species with deep intrauterine trophoblast invasion. To accomplish this task, we used clustered regularly interspaced short palindromic repeats/Cas9-mediated genome editing of the rat Comt gene. A Comt null rat model was established and its fertility characterized. Comt null male and female rats were viable and fertile. COMT deficiency did not significantly impact pregnancy outcomes, including litter size, placental and fetal weights, Mendelian and sex ratios, or pregnancy-dependent adaptations to hypoxia. Collectively, our findings indicate that pregnancy-associated phenotypic outcomes of COMT deficiency are not equivalent in mouse and rat. In rat, COMT is not required for a successful pregnancy outcome.

Dopamine in the Pathophysiology of Preeclampsia and Gestational Hypertension: Monoamine Oxidase (MAO) and Catechol-O-methyl Transferase (COMT) as Possible Mechanisms

Purpose of the Review

Hypertension in pregnancy is the global health burden. Amongst the hypertensive disorders of pregnancy, preeclampsia and gestational hypertension are the world's leading disorders that lead to both maternal and fetal morbidity and mortality.

Recent Findings

Dopamine inactive metabolites, namely, monoamine oxidase (MAO) and catechol-O-methyl transferase (COMT), have been reported to be associated with hypertensive disorders of pregnancy such preeclampsia and gestational hypertension.

Summary

This review discusses the involvement of MAO and COMT in the pathophysiology of both conditions in order to have a better understanding on the pathogenesis of both conditions, suggesting promising therapeutic interventions and subsequently reducing maternal and fetal morbidity and mortality.

Estradiol decreases blood pressure in association with redox regulation in preeclampsia

In this study, we tested a hypothesis that a short-term estradiol therapy may reduce blood pressure in preeclampsia by modulating plasma oxidative stress. The intramuscular injections of 10 mg 17-beta-estradiol were prescribed to preeclamptic pregnant women during the 3-day therapy before a labor induction. The analyses of mean arterial pressure (MAP), serum estradiol concentrations, plasma superoxide anion (O₂.), hydrogen peroxide (H₂O₂), nitrites (NO₂^-), and peroxynitrite (ONOO^-) were conducted before and during the therapy. We found that the plasma concentrations of oxidative stress markers, such as O₂^- and H₂O₂, are higher in preeclampsia and positively correlated with the MAP value. Moreover, it was shown that the plasma concentration of NO₂^- as an indicator of NO levels is higher in preeclampsia. A short-term intramuscular application of estradiol decreases the MAP value and the plasma concentration of O^.-, H₂O₂, NO₂^-, and ONOO^- in preeclampsia. A positive correlation between the decrease of MAP values and the decrease of plasma concentrations of O₂^-, H₂O₂, and ONOO^- was found in preeclampsia during a short-term estradiol therapy. We conclude that the short-term estradiol therapy decreases the MAP value in preeclampsia by modulating the plasma oxidative stress. We speculate that the estradiol metabolism in preeclampsia is an important mechanism that contributes to vascular dysfunction.

Fetal Val108/158Met catechol-O-methyltransferase (COMT) polymorphism and placental COMT activity are associated with the development of preeclampsia

OBJECTIVE

To evaluate the association between fetal and maternal catechol-O-methyltransferase (COMT) Val158Met and methyl tetrahydrofolate reductase (MTHFR) C677T functional polymorphisms and preeclampsia, examining its influence on placental COMT and in maternal 2-methoxyestradiol (2-ME) plasma levels.

DESIGN

Prospective case-control study.

SETTING

University hospital.

PATIENT(S)

A total of 53 preeclamptic and 72 normal pregnant women.

INTERVENTION(S)

Maternal and cord blood samples and placental tissue samples were obtained.

MAIN OUTCOME MEASURE(S)

Maternal and fetal COMT and MTHFR polymorphisms were genotyped. Maternal plasma 2-ME and homocysteine levels, and expression and activity of placental COMT were measured.

RESULT(S)

The odds ratio for the risk of preeclampsia for fetal COMT Met/Met was 3.22, and it increased to 8.65 when associated with fetal MTHFR TT. Placental COMT activity and expression were influenced by genotype, but COMT activity in preeclamptic placentas did not differ from control pregnancies. There was no association between any genotypes and maternal 2-ME. Homocysteine levels were higher in women with preeclampsia than in normal pregnancies, and were inversely correlated with 2-ME plasma levels, indicating that its altered metabolism may lower COMT activity in vivo.

CONCLUSION(S)

Fetal Met-Met COMT genotype reduces COMT placental expression and activity in vitro and increases preeclampsia, risk but it does not explain the difference in maternal 2-ME levels between preeclamptic and normal pregnancies. However, the preeclamptic patients had elevated homocysteine levels that correlated inversely with 2-ME, indicating that an altered methionine-homocysteine metabolism may contribute to reduce COMT activity in vivo and explain the decreased levels of 2-ME in preeclamptic women.

2-methoxyestradiol plasma levels are associated with clinical severity indices and biomarkers of preeclampsia

We investigated whether clinical severity indices and biomarkers for preeclampsia (PE) are associated with low plasmatic 2-methoxyestradiol (2ME) in the third trimester of gestation. Blood was collected from 53 women with PE and 73 control pregnant women before parturition. The concentration of 2ME was significantly higher in controls than in patients with PE (2906.43 ± 200.69 pg/mL vs 1818.41 ± 189.25 pg/mL). The risk of PE decreased as 2ME levels increased. The 2ME values were negatively correlated with systolic peak arterial pressure and proteinuria in PE. Additionally, those women with PE with lower 2ME had a more serious clinical situation and needed a more aggressive therapy. Finally, 2ME levels (in patients with PE and total population) were significantly correlated with concentrations of soluble fms-like tyrosine kinase 1 and placental growth factor . Summarizing, patients with PE had lower 2ME levels that were correlated with different clinical indices and biomarkers of severity, indicating that 2ME could be taken into account for the clinical management of this syndrome.

Association of COMT G675A and MTHFR C677T polymorphisms with hypertensive disorders of pregnancy in Mexican mestizo population

OBJECTIVE

To investigate the relationship between COMT G675A and MTHFR C677T polymorphisms and hypertension disorders of pregnancy (HDP) in a Mexican mestizo population.

DESIGN AND METHODS

This case-control study involved 194 HDP and 194 normoevolutive pregnant women. The polymorphisms were genotyped by real time PCR.

RESULTS

Our results showed that the COMT AA genotype increases the risk to HDP (OR: 2.67; 95% CI 1.33-5.35), preeclampsia (OR: 2.69; 95% CI 1.00-7.22) and gestational hypertension (OR: 3.87; 95% CI 1.25-12.0). Furthermore, the double mutant genotype (COMTAA/MTHFRTT) potency the risk to HDP more than two times (OR: 5.21; 95% CI 1.12-24.3, p=0.019).

CONCLUSION

Our work provides evidence that COMT 675AA genotype is a risk factor for HDP and that this risk is increased by the presence of MTHFR 677TT genotype in a Mexican mestizo population.

Action of Halowax 1051 on Enzymes of Phase I (CYP1A1) and Phase II (SULT1A and COMT) Metabolism in the Pig Ovary

Polychlorinated naphthalenes (PCNs) are a group of organochlorinated compounds exhibiting dioxin-like properties. Previously published data showed the direct action of PCN-rich Halowax 1051 on ovarian follicular steroidogenesis. Taking into consideration that the observed biological effects of PCNs may be frequently side effects of metabolites generated by their detoxification, the aim of this study was to determine the activity and expression of enzymes involved in phase I (cytochrome P450, family 1 (CYP1A1)) and phase II (sulfotransferase (SULT1A) and catechol-O-methyltransferase (COMT)) detoxification metabolism. Cocultures of granulosa and theca interna cells collected from sexually mature pigs were exposed to 1 pg/mL to 10 ng/mL of Halowax 1051 for 1 to 48 hours, after which levels and activities of CYP1A1, SULT1A, and COMT were measured. Dose-dependent increases of CYP1A1 activity and expression were observed. High doses of Halowax 1051 were inhibitory to COMT and SULT1A activity and reduced their protein levels. In conclusion, fast activation of phase I enzymes with simultaneous inhibition of phase II enzymes indicates that the previously observed effect of Halowax 1051 on follicular steroidogenesis may partially result from metabolite action occurring locally in ovarian follicles.