Comparative expression profiles for KiSS-1 and REN genes in preeclamptic and healthy placental tissues

Placental mRNA Expression of Neurokinin B Is Increased in PCOS Pregnancies with Female Offspring

Current research suggests that polycystic ovary syndrome (PCOS) might originate in utero and implicates the placenta in its pathogenesis. Kisspeptin (KISS1) and neurokinin B (NKB) are produced by the placenta in high amounts, and they have been implicated in several pregnancy complications associated with placental dysfunction. However, their placental expression has not been studied in PCOS. We isolated mRNA after delivery from the placentae of 31 PCOS and 37 control women with term, uncomplicated, singleton pregnancies. The expression of KISS1, NKB, and neurokinin receptors 1, 2, and 3 was analyzed with real-time polymerase chain reaction, using β-actin as the reference gene. Maternal serum and umbilical cord levels of total testosterone, sex hormone-binding globulin (SHBG), free androgen index (FAI), androstenedione, dehydroepiandrosterone sulfate (DHEAS), Anti-Mullerian hormone (AMH), and estradiol were also assessed. NKB placental mRNA expression was higher in PCOS women versus controls in pregnancies with female offspring. NKB expression depended on fetal gender, being higher in pregnancies with male fetuses, regardless of PCOS. NKB was positively correlated with umbilical cord FAI and AMH, and KISS1 was positively correlated with cord testosterone and FAI; there was also a strong positive correlation between NKB and KISS1 expression. Women with PCOS had higher serum AMH and FAI and lower SHBG than controls. Our findings indicate that NKB might be involved in the PCOS-related placental dysfunction and warrant further investigation. Studies assessing the placental expression of NKB should take fetal gender into consideration.

Associations between maternal urinary kisspeptin in late pregnancy and decreased fetal growth: a pregnancy-birth cohort study

Background

Kisspeptin has been indicated to be a biomarker of fetal growth. Although some evidence suggested that maternal kisspeptin concentrations in early pregnancy were associated with increased fetal growth, studies are still limited and the effect of kisspeptin in late pregnancy remains unknown. This study aimed to investigate the associations between maternal kisspeptin in late pregnancy and fetal growth.

Methods

Based on the Shanghai-Minhang Birth Cohort study, 724 mother-neonate pairs were included in this study. We measured maternal kisspeptin concentrations in the urine samples collected in late pregnancy and neonatal anthropometric indices at birth. The associations between maternal kisspeptin and neonatal anthropometry were investigated using multiple linear regression models.

Results

Higher maternal urinary kisspeptin concentrations were associated with lower neonatal birth weight, head circumference, upper arm circumference, abdominal skinfold thickness, triceps skinfold thickness, and back skinfold thickness. The inverse associations were more pronounced for the highest kisspeptin levels versus the lowest. These patterns were consistent in analyses stratified by neonatal sex, with notably stable associations between maternal kisspeptin concentrations and skinfold thickness.

Conclusion

The present study suggested that maternal kisspeptin concentrations in late pregnancy might be inversely associated with fetal growth. The physiological mechanisms of maternal kisspeptin might differ from those in early pregnancy. Further studies are required to assess associations between maternal kisspeptin and energy homeostasis and explore the physiological roles of kisspeptin in late pregnancy.

Kisspeptin in the Prediction of Pregnancy Complications

Kisspeptin and its receptor are central to reproductive health acting as key regulators of the reproductive endocrine axis in humans. Kisspeptin is most widely recognised as a regulator of gonadotrophin releasing hormone (GnRH) neuronal function. However, recent evidence has demonstrated that kisspeptin and its receptor also play a fundamental role during pregnancy in the regulation of placentation. Kisspeptin is abundantly expressed in syncytiotrophoblasts, and its receptor in both cyto- and syncytio-trophoblasts. Circulating levels of kisspeptin rise dramatically during healthy pregnancy, which have been proposed as having potential as a biomarker of placental function. Indeed, alterations in kisspeptin levels are associated with an increased risk of adverse maternal and foetal complications. This review summarises data evaluating kisspeptin's role as a putative biomarker of pregnancy complications including miscarriage, ectopic pregnancy (EP), preterm birth (PTB), foetal growth restriction (FGR), hypertensive disorders of pregnancy (HDP), pre-eclampsia (PE), gestational diabetes mellitus (GDM), and gestational trophoblastic disease (GTD).

The Role of Kisspeptin in the Pathogenesis of Pregnancy Complications: A Narrative Review

Kisspeptins are the family of neuropeptide products of the KISS-1 gene that exert the biological action by binding with the G-protein coupled receptor 54 (GPR54), also known as the KISS-1 receptor. The kisspeptin level dramatically increases during pregnancy, and the placenta is supposed to be its primary source. The role of kisspeptin has already been widely studied in hypogonadotropic hypogonadism, fertility, puberty disorders, and insulin resistance-related conditions, including type 2 diabetes mellitus, polycystic ovary syndrome, and obesity. Gestational diabetes mellitus (GDM), preeclampsia (PE), preterm birth, fetal growth restriction (FGR), or spontaneous abortion affected 2 to 20% of pregnancies worldwide. Their occurrence is associated with numerous short and long-term consequences for mothers and newborns; hence, novel, non-invasive predictors of their development are intensively investigated. The study aims to present a comprehensive review emphasizing the role of kisspeptin in the most common pregnancy-related disorders and neonatal outcomes. The decreased level of kisspeptin is observed in women with GDM, FGR, and a high risk of spontaneous abortion. Nevertheless, there are still many inconsistencies in kisspeptin concentration in pregnancies with preterm birth or PE. Further research is needed to determine the usefulness of kisspeptin as an early marker of gestational and neonatal complications.

Changes in Circulating Kisspeptin Levels During Each Trimester in Women With Antenatal Complications

CONTEXT

Antenatal complications such as hypertensive disorders of pregnancy (HDP), fetal growth restriction (FGR), gestational diabetes (GDM), and preterm birth (PTB) are associated with placental dysfunction. Kisspeptin has emerged as a putative marker of placental function, but limited data exist describing circulating kisspeptin levels across all 3 trimesters in women with antenatal complications.

OBJECTIVE

We aimed to assess whether kisspeptin levels are altered in women with antenatal complications.

METHODS

Women with antenatal complications (n = 105) and those with uncomplicated pregnancies (n = 265) underwent serial ultrasound scans and blood sampling at the Early Pregnancy Assessment Unit at Hammersmith Hospital, UK, at least once during each trimester (March 2014 to March 2017). The women with antenatal complications (HDP [n = 32], FGR [n = 17], GDM [n = 35], PTB [n = 11], and multiple complications [n=10]) provided 373 blood samples and the controls provided 930 samples. Differences in circulating kisspeptin levels were assessed.

RESULTS

Third-trimester kisspeptin levels were higher than controls in HDP but lower in FGR. The odds of HDP adjusted for gestational age, maternal age, ethnicity, BMI, smoking, and parity were increased by 30% (95% CI, 16%-47%; P < 0.0001), and of FGR were reduced by 28% (95% CI, 4-46%; P = 0.025), for every 1 nmol/L increase in plasma kisspeptin. Multiple of gestation-specific median values of kisspeptin were higher in pregnancies affected by PTB (P = 0.014) and lower in those with GDM (P = 0.020), but not significantly on multivariable analysis.

CONCLUSION

We delineate changes in circulating kisspeptin levels at different trimesters and evaluate the potential of kisspeptin as a biomarker for antenatal complications.

Preeclampsia and gestational hypertension are associated to low maternal circulating kisspeptin levels: a systematic review and meta-analysis

BACKGROUND

There are contradictory data concerning kisspeptin in gravids with preeclampsia and gestational hypertension (GH).

OBJECTIVE

To conduct a meta-analysis of studies comparing maternal kisspeptin levels in gravids with and without preeclampsia or GH.

MATERIAL AND METHODS

We searched PubMed, LILACS, and CNKI list of articles up to 20 August 2021, without language limitations, comparing circulating maternal kisspeptin levels, and maternal and neonatal outcomes in gravids with and without preeclampsia or GH. Meta-analyzed results are reported as standardized mean differences (SMD), and their 95% confidence interval (CI).

RESULTS

Seven studies with a low-to-moderate risk of bias were eligible for meta-analysis. Gravids with preeclampsia or GH displayed significantly lower circulating kisspeptin levels (SMD, -0.68, 95% CI, -1.04 to -0.32), lower gestational ages at delivery (SMD, -2.22, 95% CI, -3.25 to -1.18), and birth weight (SMD, -2.16, 95% CI, -3.15 to -1.17), and significantly higher body mass indices (MD, 0.56, 95% CI, 0.24-0.88), systolic (SMD, 2.87, 95% CI, 2.22-3.53), and diastolic blood pressures (SMD, 2.57, 95% CI, 2.19-2.95).

CONCLUSION

Gravids with preeclampsia or GH had lower kisspeptin levels as compared to normotensive controls.

Renin Cell Baroreceptor, a Nuclear Mechanotransducer Central for Homeostasis

[Figure: see text].

Placental protein expression of kisspeptin-1 (KISS1) and the kisspeptin-1 receptor (KISS1R) in pregnancy complicated by diabetes mellitus or preeclampsia

PURPOSE

Kisspeptins regulate the trophoblast invasion. The disturbance of this process might lead to the development of preeclampsia (PE). Diabetes mellitus (DM) is associated with the high rate of this complication. The main hypothesis was to investigate the placental protein expression of kisspeptin-1 (KISS1) and its receptor (KISS1R) in diabetic, preeclamptic, and healthy pregnancies.

METHODS

Placentae (n = 65) were divided into the following groups: the control group (n = 20), either PE or non-PE type-1 diabetes mellitus (T1DM) (n = 10), either PE or non-PE type-2 diabetes mellitus (T2DM) (n = 10), either PE or non-PE gestational diabetes mellitus (GDM) (n = 10) and preeclampsia without diabetes (PE) (n = 15). Immunohistochemistry analysis was used for demonstrating the presence and location of KISS1/KISS1R in placental tissue and to measure the area of immunopositive expression. Correlation analyses were performed to detect the links between protein expression of these biomarkers and the main obstetric outcomes.

RESULTS

The highest placental protein expressions of KISS1 were detected in the PE (35.4%) and GDM (33.2%) groups. In case of DM, levels of KISS1 expression depended on the presence of PE and were higher compared with DM no PE and control groups: (30.6%) in T1DM + PE and (30.1%) in T2DM + PE group. The lowest expression was detected in the control group (14.1%). The expression of KISS1R was higher in DM and PE compared to the control group. We detected the strong direct link between PE and placental expression of KISS1 (r = 0.81) and KISS1R (r = 0.56), and inverse correlation link between KISS1 and preterm birth weight (r = - 0.73). The low correlation links were found between KISS1 and IUGR (r = 0.29), and preterm birth (r = 0.24). The same trend was detected for KISS1R. We did not find any significant correlations between placental expressions of KISS/KISS1R and placental weight or HbA1c levels.

CONCLUSION

Increased expression levels of KISS1 and KISS1R in case of diabetes mellitus may play a role in the altered placentation process and lead to the development of preeclampsia.

Kisspeptin as a potential biomarker throughout pregnancy

Kisspeptins are a family of neuropeptides that are critical for the puberty initiation and female fertility. Plasma or serum kisspeptin is mainly derived from the placenta during pregnancy and plasma kisspeptin levels significantly increase across pregnancy. Plasma kisspeptin levels could be used as a potential biomarker for the detection of miscarriage, pre-eclampsia, gestational trophoblastic neoplasia (GTN), and fetal development. Kisspeptin may also be involved in the process of parturition by stimulating oxytocin secretion during term pregnancy. This review discussed the potential use of kisspeptin as a marker across pregnancy and highlighted the unresolved problems in this area. Tweetable abstract: Plasma kisspeptin levels could be used as a potential biomarker across pregnancy.

The core transcriptome of mammalian placentas and the divergence of expression with placental shape

INTRODUCTION

The placenta is arguably the most anatomically variable organ in mammals even though its primary function is conserved.

METHOD

Using RNA-Seq, we measured the expression profiles of 55 term placentas of 14 species of mammals representing all major eutherian superordinal clades and marsupials, and compared the evolution of expression across clades.

RESULTS

We identified a set of 115 core genes which is expressed (FPKM ≥10) in all eutherian placentas, including genes with immune-modulating properties (ANXA2, ANXA1, S100A11, S100A10, and LGALS1), cell-cell interactions (LAMC1, LUM, and LGALS1), invasion (GRB2 and RALB) and syncytialization (ANXA5 and ANXA1). We also identified multiple pre-eclampsia associated genes which are differentially expressed in Homo sapiens when compared to the other 13 species. Multiple genes are significantly associated with placenta morphology, including EREG and WNT5A which are both associated with placental shape.

DISCUSSION

115 genes are important for the core functions of the placenta in all eutherian species analyzed. The molecular functions and pathways enriched in the core placenta align with the evolutionarily conserved functionality of the placenta.

Kiss1 mutant placentas show normal structure and function in the mouse

Introduction

Kisspeptins, encoded by the Kiss1 gene, are a set of related neuropeptides that are required for activation of the mammalian reproductive axis at puberty and to maintain fertility. In addition, kisspeptin signaling via the G-protein coupled receptor GPR54 (KISS1R) has been suggested to regulate human placental formation and correlations have been found between altered kisspeptin levels in the maternal blood and the development of pre-eclampsia.

Methods

We have used Kiss1 and Gpr54 mutant mice to investigate the role of kisspeptin signaling in the structure and function of the mouse placenta.

Results

Expression of Kiss1 and Gpr54 was confirmed in the mouse placenta but no differences in birth weight were found in mice that had been supported by a mutant placenta during fetal development. Stereological measurements found no differences between Kiss1 mutant and wild-type placentas. Measurement of amino-acid and glucose transport across the Kiss1 mutant placentas at E15.5 days did not reveal any functional defects.

Discussion

These data indicate that mouse placentas can develop a normal structure and function without kisspeptin signaling and can support normal fetal development and growth.

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The structure and function of Kiss1 and Gpr54 mutant placentas was examined in transgenic mice.

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Kiss1 and Gpr54 mutant placentas are not associated with fetal loss during gestation or reduced pup weight at birth.

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Kiss1 mutant placentas show normal structural components.

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Kiss1 mutant placentas show normal transport of glucose and amino-acids.

Comparative N-glycoproteomic and phosphoproteomic profiling of human placental plasma membrane between normal and preeclampsia pregnancies with high-resolution mass spectrometry

Preeclampsia is a serious complication of pregnancy, which affects 2–8% of all pregnancies and is one of the leading causes of maternal and perinatal mortality and morbidity worldwide. To better understand the molecular mechanisms involved in pathological development of placenta in preeclampsia, we used high-resolution LC-MS/MS technologies to construct a comparative N-glycoproteomic and phosphoproteomic profiling of human placental plasma membrane in normal and preeclamptic pregnancies. A total of 1027 N-glyco- and 2094 phospho- sites were detected in human placental plasma membrane, and 5 N-glyco- and 38 phospho- proteins, respectively, with differentially expression were definitively identified between control and preeclamptic placental plasma membrane. Further bioinformatics analysis indicated that these differentially expressed proteins correlate with several specific cellular processes occurring during pathological changes of preeclamptic placental plasma membrane.

Elevated expression of KiSS-1 in placenta of Chinese women with early-onset preeclampsia

Preeclampsia (PE) is a heterogeneous syndrome affecting 2% to 8% of all pregnancies and is the world’s leading cause of fetal and maternal morbidity and mortality. In many cases of PE, shallow trophoblast invasion results in inappropriate maternal spiral artery remodeling and impaired placental function. Multiple genes have been implicated in trophoblast invasion, among which are KiSS-1 and GPR54. The gene product of KiSS-1 is metastin, which is a ligand for the receptor GPR54. Both metastin and GPR54 are expressed in the placenta of normal pregnancy and have been implicated in modulating trophoblast invasion through inhibiting migration of trophoblast cells. We have previously reported that the expression level of KiSS-1 was higher in trophoblasts from women with preeclampsia as compared to normal controls. Here, using quantitative RT-PCR, Western blot analysis and immunohistochemistry, we extend our analysis to demonstrate that elevated KiSS-1 expression occurs only in early-onset preeclampsia (ePE) and not late-onset preeclampsia (lPE). However, no difference in the expression levels of GPR54 is observed between ePE, lPE, and normal controls. Further, we show that KiSS-1 expression is also increased in placenta of intrauterine death and birth asphyxia in comparison to normal newborns of ePE and lPE. Our findings suggest that aberrant upregulation of KiSS-1 expression may contribute to the underlying mechanism of ePE as well as birth asphyxia.