Maternal serum IGF-1, IGFBP-1 and 3, and placental growth hormone at 20 weeks’ gestation in pregnancies complicated by preeclampsia

Discovery and verification of extracellular microRNA biomarkers for diagnostic and prognostic assessment of preeclampsia at triage

We report on the identification of extracellular miRNA (ex-miRNA) biomarkers for early diagnosis and prognosis of preeclampsia (PE). Small RNA sequencing of maternal serum prospectively collected from participants undergoing evaluation for suspected PE revealed distinct patterns of ex-miRNA expression among different categories of hypertensive disorders in pregnancy. Applying an iterative machine learning method identified three bivariate miRNA biomarkers (miR-522-3p/miR-4732-5p, miR-516a-5p/miR-144-3p, and miR-27b-3p/let-7b-5p) that, when applied serially, distinguished between PE cases of different severity and differentiated cases from controls with a sensitivity of 93%, specificity of 79%, positive predictive value (PPV) of 55%, and negative predictive value (NPV) of 89%. In a small independent validation cohort, these ex-miRNA biomarkers had a sensitivity of 91% and specificity of 57%. Combining these ex-miRNA biomarkers with the established sFlt1:PlGF protein biomarker ratio performed better than either set of biomarkers alone (sensitivity of 89.4%, specificity of 91.3%, PPV of 95.5%, and NPV of 80.8%).

Associations between IGFBP1 gene polymorphisms and the risk of preeclampsia and fetal growth restriction

IGFBP1 plays a critical role in the pathogenesis of preeclampsia (PE), but the association between single nucleotide polymorphism (SNP) of IGFBP1 gene and PE susceptibility has not yet been determined. In our study, 229 women with PE and 361 healthy pregnant (non-PE) women were enrolled to investigate its association via TaqMan genotyping assay. In addition, the protein levels of IGFBP1 under different genotypes were explored by ELISA and IHC. We found that IGFBP1 SNP rs1065780A > G was associated with an decreased risk for PE. Women with GG (P = 0.027) or AG (Padj. = 0.023) genotype manifested a significantly lower risk for PE compared to women with AA genotype. In PE group, women carrying G allele exhibited greater fetal birth weight, lower diastolic BP, and lower levels of ALT and AST. The G genotype was found significantly less frequently in the severe preeclampsia (SPE) group than in the non-PE group (GG vs. AA, P = 0.007; G vs. A, P = 0.006). Additionally, women in the PE group who experienced fetal growth restriction (FGR) reflected a lower level of the allele G than did the non-FGR group (P = 0.032); this was not the case for the non-PE group.Rs1065780A>G elevated IGFBP1 protein level in plasma and decidua in PE group. In conclusion Chinese Han women with the SNP IGFBP1 rs1065780 occupied by G exhibited a lower risk of developing PE relative to women with the A genotype and augured for improved pregnancy outcomes through elevation of IGFBP1 protein level.

Natriuretic Peptide Signaling in Uterine Biology and Preeclampsia

Endometrial decidualization is a uterine process essential for spiral artery remodeling, embryo implantation, and trophoblast invasion. Defects in endometrial decidualization and spiral artery remodeling are important contributing factors in preeclampsia, a major disorder in pregnancy. Atrial natriuretic peptide (ANP) is a cardiac hormone that regulates blood volume and pressure. ANP is also generated in non-cardiac tissues, such as the uterus and placenta. In recent human genome-wide association studies, multiple loci with genes involved in natriuretic peptide signaling are associated with gestational hypertension and preeclampsia. In cellular experiments and mouse models, uterine ANP has been shown to stimulate endometrial decidualization, increase TNF-related apoptosis-inducing ligand expression and secretion, and enhance apoptosis in arterial smooth muscle cells and endothelial cells. In placental trophoblasts, ANP stimulates adenosine 5'-monophosphate-activated protein kinase and the mammalian target of rapamycin complex 1 signaling, leading to autophagy inhibition and protein kinase N3 upregulation, thereby increasing trophoblast invasiveness. ANP deficiency impairs endometrial decidualization and spiral artery remodeling, causing a preeclampsia-like phenotype in mice. These findings indicate the importance of natriuretic peptide signaling in pregnancy. This review discusses the role of ANP in uterine biology and potential implications of impaired ANP signaling in preeclampsia.

A common IGF1R gene variant predicts later life breast cancer risk in women with preeclampsia

PURPOSE

Preeclampsia has been inconsistently associated with altered later life risk of cancer. This study utilizes the Nurses' Health Study 2 (NHS2) to determine if the future risk of breast and non-breast cancers in women who experience preeclampsia is modified by carrying a protective variant of rs2016347, a functional insulin-like growth factor receptor-1 (IGF1R) single nucleotide polymorphism.

METHODS

This retrospective cohort study completed within the NHS2 evaluated participants enrolled in 1989 and followed them through 2015, with a study population of 86,751 after exclusions. Cox proportional hazards models both with and without the impact of rs2016347 genotype were used to assess the risk of invasive breast cancer, hormone receptor-positive (HR+) breast cancer, and non-breast cancers.

RESULTS

Women with preeclampsia had no change in risk of all breast, HR+ breast, or non-breast cancers when not considering genotype. However, women carrying at least one T allele of rs2016347 had a lower risk of HR+ breast cancer, HR 0.67, 95% CI: 0.47-0.97, P = 0.04, with interaction term P = 0.06. For non-breast cancers as a group, women carrying a T allele had an HR 0.76, 95% CI: 0.53-1.08, P = 0.12, with interaction term P = 0.26.

CONCLUSIONS

This retrospective cohort study found that women with preeclampsia who carry a T allele of IGF1R rs2016347 had a reduced future risk of developing HR+ breast cancer, and a reduced but not statistically significant decreased risk of non-breast cancers suggesting a possible role for the IGF-1 axis in the development of cancer in these women.

Integrated Bioinformatics Analysis Reveals Novel miRNA as Biomarkers Associated with Preeclampsia

Preeclampsia is a leading cause of perinatal maternal-foetal mortality and morbidity. This study aims to identify the key microRNAs (miRNA) in preeclampsia and uncover their potential functions. We downloaded the miRNA expression profile of GSE119799 for plasma and GSE177049 for the placenta. Each dataset consisted of five patients (PE) and five controls (N). From a technical point of view, we analysed the counts per million (CPM) for both datasets, highlighting 358 miRNAs in common, 78 unique for plasma and 298 unique for placenta. At the same time, we performed an expression differential analysis (|logFC| ≥ 1|and FDR ≤ 0.05) to evaluate the biological impact of the miRNAs. This approach allowed us to highlight 321 miRNAs in common between plasma and placenta, within which four were upregulated in plasma. Furthermore, the same analysis revealed five miRNAs expressed exclusively in plasma; these were also upregulated. In conclusion, the in-depth bioinformatics analysis conducted during our study will allow us, on the one hand, to verify the targets of each of the nine identified miRNAs; on the other hand, to use them both as new non-invasive biomarkers and as therapeutic targets for the development of personalised treatments.

Fetal growth regulation via insulin-like growth factor axis in normal and diabetic pregnancy

OBJECTIVES

Diabetes mellitus (DM) in pregnancy and gestational diabetes remain a considerable cause of pregnancy complications, and fetal macrosomia is among them. Insulin, insulin-like growth factors (IGFs), and components of their signal-transduction axes belong to the predominant growth regulators and are implicated in glucose homeostasis. This study aimed to evaluate the available evidence on the association between the IGF axis and fetal anthropometric parameters in human diabetic pregnancy.

METHODS

PubMed, Medline, Web of Science, and CNKI databases (1981-2021) were searched.

RESULTS

Maternal and cord serum IGF-I levels are suggested to be positively associated with weight and length of neonates born to mothers with type 1 DM. The results concerning IGF-II and IGFBPs in type 1 DM or any of the IGF axis components in type 2 DM remain controversial. The alterations of maternal serum IGFs concentrations throughout diabetic and non-diabetic pregnancy do not appear to be the same. Maternal 1st trimester IGF-I level is positively associated with fetal birth weight in DM.

CONCLUSIONS

Research on the IGF axis should take gestational age of sampling, presence of DM, and insulin administration into account. Maternal 1st trimester IGF-I level might become a predictor for macrosomia development in diabetic pregnancy.

IGFBP1 inhibits the invasion, migration, and apoptosis of HTR-8/SVneo trophoblast cells in preeclampsia

OBJECTIVE

To investigate the effects and underlying mechanisms of IGFBP1 on the biological functions of trophoblasts in simulated preeclampsia.

METHODS

IGFBP1 expression in placenta was determined by immunohistochemistry. HTR-8/SVneo cells were stimulated with/without IGFBP1-overexpression and hypoxia-reoxygenation, and the proliferation, invasion, migration, and apoptosis were detected by CCK8, transwell, and flow cytometry, respectively.

RESULTS

IGFBP1 expression was increased in placenta of preeclampsia. IGFBP1 overexpression inhibited proliferation, invasion, migration, and apoptosis of HTR-8/SVneo cells and induced MMP-26 expression with/without hypoxia-reoxygenation challenge.

CONCLUSION

IGFBP1 affects biological functions of trophoblasts, and it may play a role in pathophysiology of preeclampsia by inducing MMP-26.

OUP accepted manuscript

Preeclampsia is a pregnancy-specific disease that can have serious effects on the health of both mothers and their offspring. Predicting which women will develop preeclampsia in early pregnancy with high accuracy will allow for improved management. The clinical symptoms of preeclampsia are well recognized, however, the precise molecular mechanisms leading to the disorder are poorly understood. This is compounded by the heterogeneous nature of preeclampsia onset, timing and severity. Indeed a multitude of poorly defined causes including genetic components implicates etiologic factors, such as immune maladaptation, placental ischemia and increased oxidative stress. Large datasets generated by microarray and next-generation sequencing have enabled the comprehensive study of preeclampsia at the molecular level. However, computational approaches to simultaneously analyze the preeclampsia transcriptomic and network data and identify clinically relevant information are currently limited. In this paper, we proposed a control theory method to identify potential preeclampsia-associated genes based on both transcriptomic and network data. First, we built a preeclampsia gene regulatory network and analyzed its controllability. We then defined two types of critical preeclampsia-associated genes that play important roles in the constructed preeclampsia-specific network. Benchmarking against differential expression, betweenness centrality and hub analysis we demonstrated that the proposed method may offer novel insights compared with other standard approaches. Next, we investigated subtype specific genes for early and late onset preeclampsia. This control theory approach could contribute to a further understanding of the molecular mechanisms contributing to preeclampsia.

Loss of imprinting of the Igf2-H19 ICR1 enhances placental endocrine capacity via sex-specific alterations in signalling pathways in the mouse

Imprinting control region (ICR1) controls the expression of the Igf2 and H19 genes in a parent-of-origin specific manner. Appropriate expression of the Igf2-H19 locus is fundamental for normal fetal development, yet the importance of ICR1 in the placental production of hormones that promote maternal nutrient allocation to the fetus is unknown. To address this, we used a novel mouse model to selectively delete ICR1 in the endocrine junctional zone (Jz) of the mouse placenta (Jz-ΔICR1). The Jz-ΔICR1 mice exhibit increased Igf2 and decreased H19 expression specifically in the Jz. This was accompanied by an expansion of Jz endocrine cell types due to enhanced rates of proliferation and increased expression of pregnancy-specific glycoprotein 23 in the placenta of both fetal sexes. However, changes in the endocrine phenotype of the placenta were related to sexually-dimorphic alterations to the abundance of Igf2 receptors and downstream signalling pathways (Pi3k-Akt and Mapk). There was no effect of Jz-ΔICR1 on the expression of targets of the H19-embedded miR-675 or on fetal weight. Our results demonstrate that ICR1 controls placental endocrine capacity via sex-dependent changes in signalling.

The Serine Protease HTRA-1 Is a Biomarker for ROP and Mediates Retinal Neovascularization

Retinopathy of prematurity (ROP) is a blinding aberrancy of retinal vascular maturation in preterm infants. Despite delayed onset after preterm birth, representing a window for therapeutic intervention, we cannot prevent or cure ROP blindness. A natural form of ROP protection exists in the setting of early-onset maternal preeclampsia, though is not well characterized. As ischemia is a central feature in both ROP and preeclampsia, we hypothesized that angiogenesis mediators may underlie this protection. To test our hypothesis we analyzed peripheral blood expression of candidate proteins with suggested roles in preeclamptic and ROP pathophysiology and with a proposed angiogenesis function (HTRA-1, IGF-1, TGFβ-1, and VEGF-A). Analysis in a discovery cohort of 40 maternal-infant pairs found that elevated HTRA-1 (high-temperature requirement-A serine peptidase-1) was significantly associated with increased risk of ROP and the absence of preeclampsia, thus fitting a model of preeclampsia-mediated ROP protection. We validated these findings and further demonstrated a dose-response between systemic infant HTRA-1 expression and risk for ROP development in a larger and more diverse validation cohort consisting of preterm infants recruited from two institutions. Functional analysis in the oxygen-induced retinopathy (OIR) murine model of ROP supported our systemic human findings at the local tissue level, demonstrating that HtrA-1 expression is elevated in both the neurosensory retina and retinal pigment epithelium by RT-PCR in the ROP disease state. Finally, transgenic mice over-expressing HtrA-1 demonstrate greater ROP disease severity in this model. Thus, HTRA-1 may underlie ROP protection in preeclampsia and represent an avenue for disease prevention, which does not currently exist.

Elevated circulating HtrA4 in preeclampsia may alter endothelial expression of senescence genes

INTRODUCTION

Preeclampsia (PE) is a serious complication of human pregnancy. Women who have had PE, especially early-onset PE (EPE), have an increased risk of cardiovascular disease (CVD) later in life. However, how PE is linked to CVD is not well understood. We previously reported that HtrA4, a placenta-specific protease, is significantly elevated in EPE, and inhibits the proliferation of endothelial cells as well as endothelial progenitor cells (EPCs). This can potentially impair endothelial repair and regeneration, leading to endothelial aging, which is a major risk factor of CVD. In this study, we examined whether HtrA4 can alter endothelial expression of senescence genes.

METHODS

Human umbilical vein endothelial cells (HUVECs) and primary EPCs isolated from cord blood of healthy pregnancies were used as in vitro models. Firstly, HUVECs were treated with HtrA4 at the highest levels detected in EPE for 48h and screened with a senescence PCR array. The results were then validated by RT-PCR and ELISA in HUVECs and EPCs treated with HtrA4 for 24 and 48h.

RESULTS

We observed that HtrA4 significantly up-regulated IGFBP3, SERPINE1 and SERPINB2, which all promote senescence. IGFBP-3 protein was also significantly elevated in the media of HtrA4-treated HUVECs. Conversely, a number of genes including CDKN2C, PCNA, CALR, CHEK2 and NOX4 were downregulated by HtrA4. Many of these genes also showed a similar trend of change in EPCs following HtrA4 treatment.

DISCUSSION

Elevation of placenta-derived HtrA4 in PE alters the expression of endothelial genes to promote cellular senescence and may contribute to premature endothelial aging.

Pregnancy Hypertension and a Commonly Inherited IGF1R Variant (rs2016347) Reduce Breast Cancer Risk by Enhancing Mammary Gland Involution

BACKGROUND

Terminal duct lobular units (TDLUs) are the anatomic sites of breast cancer initiation, and breast tissue involution resulting in lower TDLU counts has been associated with decreased breast cancer risk. The insulin-like growth factor (IGF) pathway plays a role in breast involution, and systemic changes in this developmental pathway occur with hypertensive disorders of pregnancy (HDP), which have also been associated with lower breast cancer risk, especially in women carrying a functional variant of IGF1R SNP rs2016347. We proposed that this breast cancer protective effect might be explained by increased breast tissue involution.

MATERIALS AND METHODS

We conducted a retrospective cohort study utilizing the Komen Tissue Bank, which collects breast tissue core biopsies from women without a history of breast cancer. Eighty white non-Hispanic women with a history of HDP were selected along with 120 nonexposed participants, and after genotyping for rs2016347, TDLU parameters were histologically measured blinded to participant characteristics from fixed biopsy sections.

RESULTS

Stratified models by HDP status demonstrated that among HDP+ participants, those carrying two T alleles of rs2016347 had a decrease in TDLU counts of 53.2% when compared to those with no T alleles (p=0.049). Trend analysis demonstrated a multiplicative decrease in counts of 31.6% per T allele (p=0.050). Although no statistically significant interaction was seen between HDP status and T alleles, interaction terms showed increasingly negative values reaching a p value of 0.124 for HDP × 2T alleles.

CONCLUSIONS

The observed statistically significant decrease in TDLU counts signifies increased breast epithelial involution in women with prior HDP who inherited the TT genotype of IGF1R SNP rs2016347. The increasing degree of breast involution with greater rs2016347 T allele copy number is consistent with the known progressive reduction in IGF1R expression in breast and other normal tissues.

Maternal and umbilical cord blood level of macrophage migration inhibitory factor and insulin like growth factor in Sudanese women with preeclampsia

Preeclampsia is a health concern and it is the main cause of maternal and perinatal mortality. The macrophage migration inhibitory factor (MIF) and insulin-like growth factor-I (IGF-I) are factors associated with preeclampsia. A case-control (45 women in each arm) study was conducted at Saad Abualila Maternity Hospital (Khartoum, Sudan). The cases were of women who had preeclampsia, and the controls were healthy pregnant women. The clinical and obstetrical characteristics were gathered using a questionnaire and MIF and IGF-I levels were measured by ELISA. The cases and the controls (45 in each arm) were matched in their basic data. In comparison with the healthy controls, while the median (interquartile range) of the maternal MIF [8.221 (7.334-8.820) vs. 3.717 (2.385-4.883) ng/mL, p < .001] was significantly higher, the levels of the maternal IGF-1 [1.250 (0.670-1.980) vs. 1.939 (1.056-2.752), ng/mL, p < .001] were significantly lower in the women with preeclampsia. There was no significant difference in the cord levels of both the MIF and IGF-1 between the cases and controls. In linear regression, preeclampsia was the only factor that was significantly associated with the log of the maternal MIF (-0.338 ng/mL, p < .001), IGF-1 (0.293 ng/mL, p = .005) and cord MIF (-0.340 ng/mL, p < .001) levels. Impact statement What is already known on this subject? Macrophage migration inhibitory factor (MIF) has a pivotal role in pro-inflammatory processes during pregnancy/labour and its levels have been correlated with preeclampsia. Insulin like factors are produced in the liver under the stimulation of the growth hormones; they stimulate cell differentiation proliferations. IGF-I may be implicated in the pathogenesis of the adverse effects of preeclampsia (mainly the birth weight). What do the results of this study add? The current study showed a significantly higher level of MIF and lower level IGF-1 in the women with preeclampsia. Thus, both MIF and IGF-1 might have a role in the pathogeneses of preeclampsia. What are the implications of these findings for clinical practice and/or further research? MIF and IGF might be used as reliable markers to detect preeclampsia. These markers might be used as preventive or therapeutic elements for preeclampsia.

Human Placental Growth Hormone Variant in Pathological Pregnancies

Growth hormone (GH), an endocrine hormone, primarily secreted from the anterior pituitary, stimulates growth, cell reproduction, and regeneration and is a major regulator of postnatal growth. Humans have two GH genes that encode two versions of GH proteins: a pituitary version (GH-N/GH1) and a placental GH-variant (GH-V/GH2), which are expressed in the syncytiotrophoblast and extravillous trophoblast cells of the placenta. During pregnancy, GH-V replaces GH-N in the maternal circulation at mid-late gestation as the major circulating form of GH. This remarkable change in spatial and temporal GH secretion patterns is proposed to play a role in mediating maternal adaptations to pregnancy. GH-V is associated with fetal growth, and its circulating concentrations have been investigated across a range of pregnancy complications. However, progress in this area has been hindered by a lack of readily accessible and reliable assays for measurement of GH-V. This review will discuss the potential roles of GH-V in normal and pathological pregnancies and will touch on the assays used to quantify this hormone.