A study of serum Apo A-1 and Apo B-100 levels in women with preeclampsia

Introduction to the Proteomic Analysis of Placentas with Fetal Growth Restriction and Impaired Lipid Metabolism

Fetal growth restriction (FGR) is a disorder defined as the failure of a fetus to achieve its full biological development potential due to decreased placental function, which can be attributed to a range of reasons. FGR is linked to negative health outcomes during the perinatal period, including increased morbidity and mortality. Long-term health problems, such as impaired neurological and cognitive development, as well as cardiovascular and endocrine diseases, have also been found in adulthood. Aspirin administered prophylactically to high-risk women can effectively prevent FGR. FGR pregnancy care comprises several steps, including the weekly assessment of several blood vessels using Doppler measurements, amniotic fluid index (AFI), estimated fetal weight (EFW), cardiotocography (CTG), as well as delivery by 37 weeks. Pregnancy is a complex condition characterized by metabolic adjustments that guarantee a consistent provision of vital metabolites allowing the fetus to grow and develop. The lipoprotein lipid physiology during pregnancy has significant consequences for both the fetus and baby, and for the mother. In the course of a typical pregnancy, cholesterol levels increase by roughly 50%, LDL-C (low-density lipoprotein cholesterol) levels by 30-40%, HDL-C by 25% (high-density lipoprotein cholesterol). Typically, there is also a 2- to 3-fold increase in triglycerides. Low maternal blood cholesterol levels during pregnancy are linked to a decrease in birth weight and an increased occurrence of microcephaly. FGR impacts the placenta during pregnancy, resulting in alterations in lipid metabolism. Research has been undertaken to distinguish variations in protein expression between normal placentas and those impacted by FGR. This can aid in comprehending the fundamental pathogenic mechanisms of FGR and perhaps pave the way for the creation of novel diagnostic and treatment methods. Commonly employed approaches for detecting and analyzing variations in placental proteomes include mass spectrometry, bioinformatic analysis, and various proteomic techniques.

Abnormal maternal apolipoprotein levels during pregnancy are risk factors for preterm birth in women with dichorionic twin pregnancies: A retrospective study

OBJECTIVE

In singleton-pregnant women, abnormal maternal apolipoprotein levels have been confirmed as a risk factor for preterm birth. However, there are currently no studies on the relationship of the related research in twin-pregnant women.

METHODS

This single-center retrospective study included 743 dichorionic twin-pregnant women who delivered between January 2019 and December 2020. Twins delivered before 37 weeks gestation were categorized as the preterm group, while those delivered at or after 37 weeks gestation were classified as the term group. Maternal serum apolipoprotein A1 (ApoA1) levels, apolipoprotein B (ApoB) levels, and the ApoB/ApoA1 ratio were measured in the first trimester(6-14 weeks), the second trimester(18-28 weeks) and the third trimester(after 28 weeks). We conducted SPSS analysis to evaluate the correlation between ApoA1 levels, ApoB levels, the ApoB/ApoA1 ratio and preterm birth.

RESULTS

Among the 743 included dichorionic twin-pregnant women, 53.57 % (398/743) delivered preterm. Compared with the term group, the ApoA1 levels in the third trimester were lower (p < 0.001), while the Apo B/ApoA1 ratio was higher in the second (p = 0.01) and third trimesters in the preterm group (p = 0.001). When preterm birth was categorized as iatrogenic and spontaneous preterm birth, the results were similar. In the analysis stratified by prepregnancy BMI, a higher risk of preterm birth was associated with low ApoA1 levels and a high Apo B/ApoA1 ratio in the second and third trimesters only among the subgroup of overweight/obese dichorionic twin-pregnant women.

CONCLUSIONS

Low ApoA1 levels and a high Apo B/ApoA1 ratio during the second and third trimesters were associated with a high incidence of preterm birth for overweight/obese dichorionic twin-pregnant women.

APOA1 Is a Novel Marker for Preeclampsia

Preeclampsia (PE) is one of the pregnancy complications, leading to major maternal and fetal morbidity and mortality; however, the underlying mechanisms of PE still remain unclear. We aimed to explore the role of apolipoprotein A1 (APOA1) in the pathophysiology of PE. The expression of APOA1 was elevated in both plasma and placental tissues, as detected by Western blotting, immunohistochemistry, and a qRT-PCR assay. Importantly, we detected the concentration of APOA1 using the ELISA assay in normal control women (n = 30) and women with preeclampsia (n = 29) from a prospective cohort study. The concentration of APOA1 was not significantly altered in plasma during early and mid-term gestation of the PE patients compared to the NP patients; however, it was elevated during late gestation. Additionally, the concentration of APOA1 was positively associated with systolic blood pressure during late gestation. The proliferation and invasion of trophoblast were all increased in HTR8/SVneo cells transfected with APOA1 siRNA and decreased in HTR8/SVneo cells treated with the recombinant human APOA1 protein (rhAPOA1). Additionally, we used public datasets to investigate the downstream genes of APOA1 and qRT-PCR for validation. Furthermore, we explored the transcriptional activity of peroxisome proliferator-activated receptor gamma (PPARγ) in APOA1 by using a luciferase assay, which showed that the APOA1 promoter was activated by PPARγ. Additionally, the inhibitory effect of rhAPOA1 on the ability of trophoblast invasion and proliferation can be rescued by the PPARγ inhibitor. Our findings suggest the crucial role of APOA1 in PE, which might provide a new strategy for the prevention and treatment of PE.

Maternal Supraphysiological Hypercholesterolemia Is Accompanied by Shifts in the Composition and Anti-Atherogenic Functions of Maternal HDL along with Maternal Cardiovascular Risk Markers at Term of Pregnancy

BACKGROUND

Maternal physiological hypercholesterolemia (MPH) occurs in pregnancy for a proper fetal development. When cholesterol increases over the physiological range, maternal supraphysiological hypercholesterolemia (MSPH) is described, a condition underdiagnosed by a lack of evidence showing its biological and clinical relevance.

AIM

To determine if MSPH associates with maternal vascular dysfunction, along with changes in the composition and function of maternal HDL leading to increased cardiovascular risk.

METHODS

This study included 57 women at term of pregnancy in which a lipid profile was determined.

RESULTS

Maternal total cholesterol (TC) and LDL but not HDL were increased in MSPH women. The isolated HDL from a subgroup of MSPH women had a lower protein abundance and a reduced activity of the antioxidant enzyme PON1; however, an increased antioxidant capacity compared to MPH was observed, along with higher serum levels of α-tocopherol. Moreover, HDL from a subgroup of MSPH women had a lower capacity to induce NO synthesis in endothelial cells compared to MPH. In the circulation, we observed a reduced total antioxidant capacity and augmented levels of soluble VCAM, ApoB, ApoCII, ApoCIII, IL-10, and IL-12p70, as well as the cardiovascular risk ratio ApoB/ApoAI, compared to MPH women.

CONCLUSION

MSPH women present dysfunctional HDL and increased atherogenic cardiovascular risk factors.

Associations between maternal mid-pregnancy apolipoprotein A-1, apolipoprotein B, apolipoprotein B/apolipoprotein A-1 ratio and preterm birth

BACKGROUND AND AIMS

Elevated lipid levels during pregnancy have been shown to be related to the risk of preterm birth. Despite the importance of apolipoprotein (Apo) in lipid metabolism and transportation, evidence regarding apolipoprotein levels during pregnancy and preterm birth is still limited. Therefore, we aim to investigate the associations between maternal ApoA-1, ApoB, ApoB/ApoA-1 ratio and preterm birth.

MATERIALS AND METH

Data were extracted from the information system of Guangdong Women and Children Hospital. Lipoprotein levels were tested using Beckman Coulter AU5800 in mid-pregnancy at a median gestational age of 18 w. Maternal serum ApoB, ApoA-1 and ApoB/ApoA-1 ratio were categorized into tertiles. Logistic regression models were performed to evaluate the odds ratios and 95% confidence intervals for preterm birth.

RESULTS

A total of 5,986 maternal-newborn pairs were included in this study. The rate of preterm birth was 5.7% (n = 344). The multivariate-adjusted ORs (95% CI) of preterm birth were 1.51 (1.06, 2.10) for individuals with high ApoB (>90th), 0.63 (0.38, 0.99) for those with low ApoB (<10th), and 1.64 (1.18, 2.24) for those with high ApoB/ApoA-1 (>90th). Subgroup analyses showed that the association of ApoB and preterm birth was only significant among women with pre-pregnancy BMI 18.5-24 kg/m² (OR = 1.36, 95% CI: 1.12-1.65), age at delivery ≥ 35 years (OR = 1.43, 95% CI: 1.12-1.83).

CONCLUSION

Elevated maternal ApoB level and ApoB/ApoA-1 ratio during mid-pregnancy were related to increased risk of preterm birth. Monitoring maternal serum apolipoprotein levels may help to identify the high-risk population of preterm birth.

Quantitative proteomic analysis of serum-purified exosomes identifies putative pre-eclampsia-associated biomarkers

BACKGROUND

The high incidence of pre-eclampsia, which affects 2-7% of all pregnancies, remains a major health concern. Detection of pre-eclampsia before the appearance of clinical symptoms is essential to allow early intervention, and would benefit from identification of plasma/serum biomarkers to help guide diagnosis and treatment. Liquid biopsy has emerged as a promising source of protein biomarkers that circumvents some of the inherent challenges of proteome-wide analysis of plasma/serum. In this respect, purified exosomes have the added benefit of being carriers of intercellular communication both in physiological and pathological conditions.

METHODS

We compared the protein complement of purified exosomes from three different collections of control and pre-eclamptic serum samples, obtained at the end of the second trimester of pregnancy and at delivery. We employed shotgun label-free proteomics to investigate differential protein expression, which was then validated by targeted proteomics.

RESULTS

We developed a purification method that yielded highly enriched exosome preparations. The presence of specific pregnancy protein markers suggested that a significant proportion of purified exosomes derived from tissues related to pregnancy. Quantitative proteomic analyses allowed us to identify 10, 114 and 98 differentially-regulated proteins in the three sample collections, with a high degree of concordance. Functional analysis suggested that these proteins participate in biological processes related to pre-eclampsia, including angiogenesis, inflammation and cell migration. The differential abundance of 66 proteins was validated by targeted proteomics. Finally, we studied the impact of the pre-eclampsia-associated exosomes in the proteome using an in vitro cellular model.

CONCLUSIONS

We have identified and validated differential exosomal proteins in liquid biopsy of pregnant women that open new possibilities for early detection of pre-eclampsia. Additionally, the functional impact of the proteome composition of purified pre-eclamptic exosomes in target cells provides new information to better understand changes in embryo-maternal interactions and, consequently, the pathogenesis of this disease.

Upregulation of ENDOU in cytotrophoblasts from placenta complicated with preeclampsia and fetal growth restriction

Placental hypoplasia is associated with the pathophysiology of fetal growth restriction and preeclampsia. The placenta consists of differentiated trophoblasts, including cytotrophoblasts, syncytiotrophoblasts, and extravillous trophoblasts. Cytotrophoblasts are thought to have stem-like characteristics and the ability to differentiate into syncytiotrophoblasts and extravillous trophoblasts. However, it is poorly understood whether isolated cytotrophoblasts derived from hypoplastic placentas have specific features compared with those in normal placentas. This study aimed to determine the features of cytotrophoblasts in hypoplastic placentas. Differentially expressed proteins between isolated cytotrophoblasts from hypoplastic placenta with fetal growth restriction and those from the normal placenta were determined by liquid chromatography-tandem mass spectrometry. Among 6,802 proteins, 1,253 and 2,129 proteins were more than 2-fold upregulated and downregulated, respectively. Among them, ENDOU (endonuclease, poly(U) specific), which has high homology with the coronavirus endoribonuclease nonstructural protein 15 (Nsp15), showed a significantly increased expression in cytotrophoblasts from the placenta with fetal growth restriction related to preeclampsia compared with those in normal control placenta. These results provide insight into the pathological mechanisms of placental hypoplasia and additional information on preeclamptic symptoms in cases of SARS-CoV-2 infected placenta, although further investigation is needed.

Management of familial hypercholesterolemia in pregnancy

PURPOSE OF REVIEW

To highlight quandaries and review options for the management of familial hypercholesterolemia (FH) during pregnancy.

RECENT FINDINGS

Women with FH face barriers to effective care and consequently face significant disease related long term morbidity and mortality.Pregnancy includes major maternal physiological changes resulting in exacerbation of maternal hypercholesterolemia compounded by the current practice of cessation or reduction in the dose of lipid-lowering therapy during pregnancy and lactation that may impact short and long term cardiac morbidity and mortality. Although lipoprotein apheresis is the treatment of choice for high- risk FH patients, reassuring safety evidence for the use of statins during pregnancy is mounting rapidly. However, it will be some time before subtle effects on the development of the offspring can be definitively excluded. Women with homozygous FH or with an established atherosclerotic vessel or aortic disease should be offered therapy with statins during pregnancy if lipoprotein apheresis is not readily available. Pregnancy outcomes tend to be favourable in women with FH. We have reviewed the currently available evidence regarding the risks and benefits of treatment options for FH during pregnancy.

Serum biomarkers for the prediction and diagnosis of preeclampsia: A meta-analysis

Objective

Preeclampsia is a major risk factor for maternal and foetal mortality and morbidity. There have been tremendous efforts to identify serum biomarkers which can reliably predict the occurrence of preeclampsia. The study aims to assess the biomarkers that have the greatest utility in the diagnosis of preeclampsia.

Methods

A systematic search was performed on the PubMed literature database, and chain references were retrieved. Original research articles composed of case controls, cohorts, randomised control trials, and cross-sectional studies were included. The recorded variables included each study's design, type, year, and location; the value (mean ± standard deviation) of the markers in the patients and the pregnant controls; and the p-value, unit of measurement, and the sample size of each study. The results were interpreted based on the standardised mean difference (SMD) values.

Results

A total of 398 studies were retrieved from the PubMed database. After further analysis, 89 studies were selected for this review. An additional 47 studies were included based on chain referencing. Later, 136 full-text articles were reviewed in detail and their data were entered. Finally, 25 studies, in which 13 serum biomarkers were assessed, were selected for this meta-analysis. The levels of the angiogenic markers fms-like tyrosine kinase (sFlt), sFlt/placental growth factor (PlGF), and endoglin were significantly higher in patients with preeclampsia than in the pregnant controls. The levels of PlGF and the lipid biomarkers high density lipoprotein (HDL) and adiponectin were significantly lower, while the levels of triglycerides, apolipoprotein B (APO-B), and leptin were elevated in the preeclamptic patients compared to the pregnant controls (p < 0.05).

Conclusion

In our study, the values of the serum biomarkers sFlt, PlGF, sFlt/PlGF, HDL, adiponectin, leptin, triglycerides, and APO-B differed significantly between preeclampsia patients and the pregnant controls. These findings demand advanced evaluation of biomarkers to enhance diagnostic screening for preeclampsia.

Serum apolipoprotein B/apolipoprotein A1 ratio in relation to intervertebral disk herniation: a cross-sectional frequency-matched case-control study

Study design

This was a cross-sectional frequency-matched case–control study.

Background and aim

The serum lipid profile of lipoprotein(a) [Lp(a)] level and apolipoprotein B/apolipoprotein A1 ratio (Apo B/Apo A1) ratio were found to be more representative for serum lipid level and were recognized as the independent risk factors for various diseases. Although the blood levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were found to be associated with symptomatic intervertebral disk herniation (IDH), no studies to date have evaluated the association of Apo AI, Apo B, Lp(a), and Apo B/Apo AI levels with symptomatic IDH. This study aimed to assess the link between blood lipid levels and symptomatic IDH.

Method

The study included 1839 Chinese patients. Of these, 918 patients were diagnosed with IDH and enrolled in the experimental group. A control group of 921 patients underwent a physical examination during the same period. The serum lipid levels of TC, TG, LDL-C, HDL-C, Lp(a), Apo B, and Apo B/Apo AI were examined and analyzed. The control group comprised randomly selected patients who met the baseline levels of the aforementioned lipid molecules.

Results

Patients with IDH exhibited significantly higher TC, TG, LDL, Apo B, and Lp(a) levels than controls. The percentage of high TC, high TG, high LDL, high Apo B, and high Lp(a) were obviously higher in the IDH group than in the control group. However, hyperlipidemia had no relationship with the degenerated segment of the IDH (P = 0.201). The odds ratio (OR) for the incidence of IDH with elevated levels of LDL-C, TC, TG, Lp(a), Apo B, and Apo B/Apo AI was 1.583, 1.74, 1.62, 1.58, 1.49, and 1.39, respectively. The correlation analysis revealed the correlation between elevated LDL-C, TC, TG, Apo B, Lp(a), and incidence of IDH was significant (R²_LDL = 0.017; R²_TC = 0.004; R²_TG = 0.015; R²_{Apo B} = 0.004; R²_Lp(a) = 0.021) (P < 0.05).

Conclusion

This study suggested that elevated levels of serum TC, TG, LDL, Apo B, Lp(a), and Apo B/Apo AI were associated with a higher risk of IDH. This study provided useful information to identify a population that might be at risk of developing IDH based on elevated lipid levels.

Genetic markers for preeclampsia in Peruvian women

BACKGROUND

Preeclampsia is a multiorgan disorder associated with maternal and perinatal morbi-mortality. In Peru, incidence is 10% and accounts for 22% of maternal deaths. Genome and genetic epidemiological studies have found an association between preeclampsia and genetic polymorphisms.

OBJECTIVE

To determine the association of the vascular endothelial growth factor (VEGF) +936 C/T and +405 G/C, interleukine-6 (IL-6) -174 G/C, IL-1β-511 C/T, Apo A-1-75 G/A, Apo B-100 2488 C/T (Xbal) polymorphisms with preeclampsia in pregnant Peruvian women.

METHODS

Were included preeclamptic and healthy (control) pregnant women. Maternal blood samples were subjected to DNA extraction, and molecular genetic analysis was conducted using the PCR-RFLP technique and following a specific protocol for each gene. Allele and genotypic frequencies in the cases and controls were compared.

RESULTS

No association was found between the VEGF+936C/T and VEGF+405 polymorphisms and preeclampsia. The frequencies of the GG genotypes and the G allele of the -174 G/C polymorphism in the IL6 gene in preeclamptic and controls showed significant differences, with higher frequencies in cases. For the -511 C/T polymorphism of the IL-1β gene, no significant differences were found in the frequencies of TT genotypes compared with CT+CC. The genotypes and alleles of the Apo-A1-75 G/A and Apo-B100 Xbal variants showed no significant differences between cases and controls.

CONCLUSION

No association was found between the studied genetic markers and preeclampsia. However, in the -174G/C polymorphism of the IL-6 gene, significant differences were found mainly in the GG genotype and G allele.

Gestational Diabetes Type 2: Variation in High-Density Lipoproteins Composition and Function

Aims: Class A2 gestational diabetes mellitus (GDMA2) has short- and long-term effects on the mother and child. These may include abnormalities of placentation, damage to endothelial cells and cardiovascular disease. This research investigated the function and composition of high-density lipoproteins (HDL) among women with GDMA2 and their fetuses. Methods: Thirty pregnant women were recruited during admission for delivery. The function and expression of HDL, paraoxonase1 (PON1) and apolipoprotein A1 (APOA1) in the blood samples and the placental tissue were evaluated. The effect of HDL on migration of endothelial cells was measured in vitro. Results: Compared to normal pregnancy (NP), APOA1 in the maternal plasma of women with GDMA2 was decreased. More APOA1 and PON1 were released from HDL of women with GDMA2, compared to NP. Placental APOA1 and PON1 were decreased in GDMA2. For endothelial cells stimulated with TNFα, HDL cell migration was decreased when cells were evaluated with NP-HDL, as compared to GDMA2-HDL. Conclusions: GDMA2 affects the composition and function of HDL in plasma. Changes in HDL commonly seen in GDMA2 were observed in maternal and placental samples, but not in cord samples. These results might indicate a placental role in protecting the fetus by preserving the components and functions of HDL and require further investigation.

Preeclampsia: a gestational cardiorenal syndrome

It is generally accepted today that there are two different types of preeclampsia: an early-onset or placental type and a late-onset or maternal type. In the latent phase, the first one presents with a low output/high resistance circulation eventually leading in the late second or early third trimester to an intense and acutely aggravating systemic disorder with an important impact on maternal and neonatal mortality and morbidity; the other type presents initially as a high volume/low resistance circulation, gradually evolving to a state of circulatory decompensation usually in the later stages of pregnancy, with a less severe impact on maternal and neonatal outcome. For both processes, numerous dysfunctions of the heart, kidneys, arteries, veins and interconnecting systems are reported, most of them presenting earlier and more severely in early- than in late-onset preeclampsia; however, some very specific dysfunctions exist for either type. Experimental, clinical and epidemiological observations before, during and after pregnancy are consistent with gestation-induced worsening of subclinical pre-existing chronic cardiovascular dysfunction in early-onset preeclampsia, and thus sharing the pathophysiology of cardiorenal syndrome type II, and with acute volume overload decompensation of the maternal circulation in late-onset preeclampsia, thus sharing the pathophysiology of cardiorenal syndrome type 1. Cardiorenal syndrome type V is consistent with the process of preeclampsia superimposed upon clinical cardiovascular and/or renal disease, alone or as part of a systemic disorder. This review focuses on the specific differences in haemodynamic dysfunctions between the two types of preeclampsia, with special emphasis on the interorgan interactions between heart and kidneys, introducing the theoretical concept that the pathophysiological processes of preeclampsia can be regarded as the gestational manifestations of cardiorenal syndromes.

Maternal Apolipoprotein B100 Serum Levels are Diminished in Pregnancies with Intrauterine Growth Restriction and Differentiate from Controls

PURPOSE

Intrauterine growth restriction, a major cause of fetal morbidity and mortality, is defined as a condition in which the fetus does not reach its genetically given growth potential. Screening for intrauterine growth restriction biomarkers in the mother's blood would be of great help for optimal pregnancy management and timing of delivery as well as for identifying fetuses requiring further surveillance during their infancies.

EXPERIMENTAL DESIGN

A multiplexing serological assay based on liquid chromatography-multiple-reaction-monitoring mass spectrometry is applied for distinguishing serum samples of pregnant women.

RESULTS

Assessment of concentrations of apolipoproteins and of proteins that belong to the lipid transport system is performed with maternal serum samples, consuming only 10 μL of serum per multiplex assay from each patient. Of all investigated proteins the serum concentrations of apolipoprotein B100 shows the greatest power for discriminating intrauterine growth restriction from control samples, reaching areas under curves above 0.85 in receiver-operator-characteristics analyses.

CONCLUSIONS

These results indicate the potential of liquid chromatography-multiple-reaction-monitoring mass spectrometry to become of clinical importance in the future for intrauterine growth restriction risk assessment based on maternal apolipoprotein B100 serum levels.

A Common Profile of Disordered Angiogenic Factor Production and the Exacerbation of Inflammation in Early Preeclampsia, Late Preeclampsia, and Intrauterine Growth Restriction

Preeclampsia and intrauterine growth restriction are two separate disease entities that, according to numerous reports, share the same pathogenesis. In both, angiogenesis disorders and generalized inflammation are the dominant symptoms. In this study, we hypothesized that both diseases demonstrate the same profile in early preeclampsia, late preeclampsia, and intrauterine growth restriction patients, with the only difference being the degree of exacerbation of lesions. One hundred sixty-seven patients were enrolled in the study and divided into four groups: early preeclampsia, late preeclampsia, and intrauterine growth restriction groups, and one control group. Concentrations of the angiogenesis and inflammatory markers soluble fms-like tyrosine kinase receptor 1, placental growth factor, high-sensitivity C-reactive protein, and interleukin-6 were determined, and the behavior of these markers and correlations among them were studied. Higher concentrations of soluble fms-like tyrosine kinase receptor 1, high-sensitivity C-reactive protein, and interleukin-6 and a lower concentration of placental growth factor were observed in the study groups compared with the control group. No differences in concentrations of the studied markers were found among the study groups but significant correlations were observed. The higher values for the angiogenesis and inflammatory markers both in preeclampsia patients and patients with intrauterine growth restriction of placental origin compared with the control group suggest the existence of the same underlying disorders in the development of these pathologies. The observed mutual correlations for disordered angiogenesis and inflammatory markers are suggestive of a mutual relationship between these processes in the development of pathologies evolving secondary to placental ischemia. The same lesion profile was observed for both preeclampsia and ‘placental’ intrauterine growth restriction patients, which could be used in developing common diagnostic criteria for pregnant patients.