Lipid abnormalities in pre-eclampsia: implications for vascular health

The impact of early pregnancy metabolic disorders on pregnancy outcome and the specific mechanism

Miscarriage is the most common complication of pregnancy. The most common causes of early miscarriage are chromosomal abnormalities of the embryo, maternal endocrine abnormalities, organ malformations, and abnormal immune factors. Late miscarriages are mostly caused by factors such as cervical insufficiency. However, the causes of 50% of miscarriages remain unknown. Recently, increasing attention has been given to the role of metabolic abnormalities in miscarriage. In this review, we mainly discuss the roles of four major metabolic pathways (glucose, lipid, and amino acid metabolism, and oxidation‒reduction balance) in miscarriage and the metabolism-related genes that lead to metabolic disorders in miscarriage. Depending on aetiology, the current treatments for miscarriage include hormonal and immunological drugs, as well as surgery, while there are few therapies for metabolism. Therefore, we also summarize the drugs for metabolism-related targets. The study of altered metabolism underlying miscarriage not only helps us to understand the mechanisms involved in miscarriage but also provides an important basis for clinical research on new therapies.

Preeclampsia Affects Lipid Metabolism and HDL Function in Mothers and Their Offspring

Preeclampsia (PE) is linked to an overall increased cardiovascular risk for both the mother and child. Functional impairment of high-density lipoproteins (HDL) may contribute to the excess cardiovascular risk associated with PE. In this study, we investigated the effects of PE on maternal and neonatal lipid metabolism, and the parameters of HDL composition and function. The study cohort included 32 normotensive pregnant women, 18 women diagnosed with early-onset PE, and 14 women with late-onset PE. In mothers, early- and late-onset PE was associated with atherogenic dyslipidemia, characterized by high plasma triglycerides and low HDL-cholesterol levels. We observed a shift from large HDL to smaller HDL subclasses in early-onset PE, which was associated with an increased plasma antioxidant capacity in mothers. PE was further associated with markedly increased levels of HDL-associated apolipoprotein (apo) C-II in mothers, and linked to the triglyceride content of HDL. In neonates of early-onset PE, total cholesterol levels were increased, whereas HDL cholesterol efflux capacity was markedly reduced in neonates from late-onset PE. In conclusion, early- and late-onset PE profoundly affect maternal lipid metabolism, potentially contributing to disease manifestation and increased cardiovascular risk later in life. PE is also associated with changes in neonatal HDL composition and function, demonstrating that complications of pregnancy affect neonatal lipoprotein metabolism.

Copy Number Analyses Identified a Novel Gene: APOBEC3A Related to Lipid Metabolism in the Pathogenesis of Preeclampsia

Background

Preeclampsia is a heterogeneous and complex disease with its pathogenesis mechanism not fully elucidated. A certain subset of patients with preeclampsia exhibit disturbances in lipid metabolism before clinical symptoms. Moreover, there is a tendency for preeclampsia to run in families. Whether genetic factors play a role in abnormal lipid metabolism during the incidence of preeclampsia has not been well investigated.

Methods

Preeclampsia patients (n = 110) and healthy age- and gravidity-matched pregnant women (n = 110) were enrolled in this study. Peripheral blood specimens were used for genomic analysis (n = 10/group) or laboratory validation (n = 100/group). We retrospectively obtained the baseline clinical characteristics of 68 preeclampsia patients and 107 controls in early pregnancy (12–14 gestational weeks). Correlation analyses between differential genes and baseline lipid profiles were performed to identify candidate genes. In vitro and in vivo gain-of-function models were constructed with lentivirus and adeno-associated virus systems, respectively, to investigate the role of candidate genes in regulating lipid metabolism and the development of preeclampsia.

Results

We observed that preeclampsia patients exhibited significantly elevated plasma TC (P = 0.037) and TG (P < 0.001) levels and increased body mass index (P = 0.006) before the disease onset. Within the region of 27 differential copy number variations, six genes potentially connected with lipid metabolism were identified. The aberrant copies of APOBEC3A, APOBEC3A_B, BTNL3, and LMF1 between preeclampsia patients and controls were verified by quantitative polymerase chain reaction. Especially, APOBEC3A showed a significant positive correlation with TC (P < 0.001) and LDL (P = 0.048) in early pregnancy. Then, our in vitro data revealed that overexpression of APOBEC3A disrupted lipid metabolism in HepG2 cells and affected both cholesterol and fatty acid metabolisms. Finally, in vivo study in a hepatic-specific overexpressed APOBEC3A mouse model revealed abnormal parameters related to lipid metabolism. Pregnant mice of the same model at the end of pregnancy showed changes related to preeclampsia-like symptoms, such as increases in sFlt-1 levels and sFlt-1/PLGF ratios in the placenta and decreases in fetal weight.

Conclusion

Our findings established a new link between genetics and lipid metabolism in the pathogenesis of preeclampsia and could contribute to a better understanding of the molecular mechanisms of preeclampsia.

Comprehensive fatty acid fractionation profilling in preeclampsia: a case control study with multivariable analysis

Background

Preeclampsia is a complication during pregnancy characterised by new-onset hypertension and proteinuria that develops after 20 weeks of gestation. Dyslipidemia in pregnancy is correlated with an increased risk of preeclampsia. However, the dynamic changes in lipid metabolic product, particularly fatty acid fraction, in preeclampsia maternal circulation, are not well understood. This study aimed to investigate fatty acid fraction in preeclampsia maternal blood compared with normotensive normal pregnancy.

Methods

A total of 34 women who developed preeclampsia and 32 women with normotensive normal pregnancy were included in our case-control study. Maternal blood samples were collected for serum fatty acid fractions analysis and other biochemical parameters. Serum fatty acid fractions included long-chain polyunsaturated fatty acid (LCPUFA), monounsaturated fatty acid (MUFA), saturated fatty acid, and total fatty acid, measured with gas chromatography-mass spectrometry (GC-MS). The mean difference of fatty acid level was analysed using parametric and non-parametric bivariate analysis based on normality distributed data, while the risk of preeclampsia based on fatty acid fraction was analysed using a logistic regression model.

Results

Women with preeclampsia have lower high-density lipoprotein (53.97 ± 12.82 mg/dL vs. 63.71 ± 15.20 mg/dL, p = 0.006), higher triglyceride (284.91 ± 97.68 mg/dL vs. 232.84 ± 73.69 mg/dL, p = 0.018) than that in the normotensive group. Higher palmitoleic acid was found in women with preeclampsia compared to normotensive normal pregnancy (422.94 ± 195.99 vs. 325.71 ± 111.03 μmol/L, p = 0.037). The binary logistic regression model showed that pregnant women who had total omega-3 levels within the reference values had a higher risk of suffering preeclampsia than those with the higher reference value (odds ratio OR (95% CI): 8,5 (1.51–48.07), p = 0.015). Pregnant women who have saturated fatty acid within reference values had a lower risk for suffering preeclampsia than those in upper reference value (OR (95% CI): 0.21 (0.52–0.88), p = 0.032).

Conclusion

Overall, palmitoleic acid was higher in women with preeclampsia. Further analysis indicated that reference omega-3 in and high saturated fatty acid serum levels are characteristics of women with preeclampsia.

Antioxidant status in hypertensive disorders of pregnancy

Objective: Pregnancy can be associated with maternal hypertension leading to possible complications in pregnancy outcome. Antioxidant status may be proned to changes during pregnancy with hypertension. The aim of our study was to estimate antioxidant status through high-risk pregnancies.Methods: Seventy-nine pregnant women with high-risk for preeclampsia development were included and 46 of them developed some hypertensive disorder in pregnancy. Superoxide-dismutase (SOD) and paraoxonase 1 (PON1) activities and relative proportion of PON1 activiity on different HDL subclasses were determined in 1^st, 2^nd, and 3^rd trimester and prior to delivery.Results: SOD activity was significantly lower in 2^nd and 3^rd trimesters when compared to 1^st trimester (P˂0.001) whereas PON1 activity was significantly higher in 3^rd than in 1^st trimester (P˂0.05) in group of hypertensive women. This group had significantly higher SOD and PON1 activities and relative proportion of PON1 on HDL_3c subclasses in the 1^st trimester, significantly increased PON1 in the 3^rd trimester and prior to delivery and significantly higher PON1 activity on HDL_3c subclasses (P˂0.05) than nonhypertensive group. In 1^st trimester and prior to delivery, total PON1 activity and relative proportion of PON1 on HDL_3c subclasses exhibited significant ability to mark out hypertension in pregnancy (P˂0.05).Conclusions: SOD activity decreased whereas total PON1 activity increased during pregnancy with hypertension. Pregnant women with hypertension had higher activities of PON1 and SOD and relative proportion of PON1 on HDL_3c subclasses than nonhypertensive ones. PON1 activity and relative proportion of PON1 on HDL_3c subclasses exhibited significant association with hypertension in pregnancy.

Serum perfluoroalkyl substances in relation to lipid metabolism in Chinese pregnant women

Laboratory and epidemiologic studies suggested that exposure to perfluoroalkyl substances (PFASs) could affect lipid metabolisms, but data remain limited for pregnant women. A total of 436 pregnant women were selected in Tangshan City, North China. Serum levels of 11 PFASs were determined in the early term of pregnancy. Four lipids (total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL)) were measured in the late term of pregnancy. Of 11 PFASs, seven had a detection rate of greater than 70%. After adjusting for potential confounders, natural log-transformed perfluororohexanesulfonic acid (ln PFHxS) was positively associated with TC (β: 0.184, 95% CI: 0.045-0.321), HDL (β: 0.040, 95% CI: 0.001-0.083), and LDL (β: 0.091, 95% CI: 0.001-0.185). Ln perfluoroundecanoic acid (PFUdA) was positively associated with HDL (β: 0.021, 95% CI: 0.001-0.044), while Ln perfluorodecanoic acid (PFDA) was negatively associated with LDL (β: -0.053, 95% CI: -0.098∼-0.009) and ln perfluorootanoic acid (PFOA) was negatively associated with LDL/HDL (β: -0.042, 95% CI: -0.075∼-0.009). In principal component analysis, the component with a large loading of 31.3% for PFOA, perfluorononanoic acid (PFNA), PFDA and PFUdA showed a negative association with LDL/HDL. After serum concentrations of PFASs were categorized into quartiles, a higher level of TC was seen in the second quartile of PFOA or PFNA than the first quartile, but a lower LDL/HDL ratio was seen in the fourth quartile of PFOA, PFUdA or PFDA. These results suggested that exposure to PFASs has a potential to influence lipid metabolisms in pregnant women.

Maternal lipid levels in preeclampsia: singleton vs. twin pregnancies

OBJECTIVE

To compare the maternal lipid levels in preeclampsia (PE) patients between singleton and twin pregnancies.

METHODS

In this retrospective study, pregnant women with PE were divided into singleton group (n = 702) and twin group (n = 198). Serum lipids which include total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured and the TC/HDL-C ratio, TG/HDL-C ratio, and LDL-C/HDL-C ratio were calculated and compared between the two groups. Covariance analysis was used to correct the potential factors affecting serum lipid levels such as maternal age, pre-pregnancy body mass index, gestational weight gain, etc.

RESULTS

The levels of TC, TG, LDL-C, and TC/HDL-C ratio, TG/HDL-C ratio, LDL-C/HDL-C ratio in twin PE were significantly higher than those in singleton PE group, and there was no significant difference in the level of HDL-C between the two groups. In late-onset PE patients, the lipid levels of TC, TG, LDL-C, and TC/HDL-C ratio, TG/HDL-C ratio, LDL-C/HDL-C ratio in twin PE group were significantly higher than those in singleton PE group, with no significant difference in the level of HDL-C. However, in early-onset PE patients, there were no significant differences in the lipid levels between the two groups.

CONCLUSIONS

There were more obvious lipid disturbances such as higher levels of TC, TG, LDL-C, and TC/HDL-C ratio, TG/HDL-C ratio, LDL-C/HDL-C ratio in twin PE group than singleton PE group. The differences of lipid levels appeared mainly in late-onset PE group, while the lipid levels in twin PE group were similar to those in singleton PE group during pregnancy in early-onset PE group.

Placental lipid metabolism in preeclampsia

OBJECTIVES

The current study examines the placental and maternal lipid profile and expression of genes involved in placental lipid metabolism in women with preeclampsia.

METHODS

The current study includes normotensive control women (n = 40) and women with preeclampsia (n = 39). Preeclampsia women were further classified into women delivering at term preeclampsia (T-PE; n = 15) and preterm preeclampsia (PT-PE; n = 24).

RESULTS

There were no significant differences in maternal lipid profile between the T-PE and normotensive control groups. Maternal plasma VLDL (P < 0.05) and ratios of total cholesterol : HDL (P < 0.05), atherogenic index [log (triglycerides/HDL)] (P < 0.01) and apolipoprotein B : apolipoprotein A (P < 0.05) were higher in the PT-PE group as compared with the normotensive control group. Placental total cholesterol and HDL levels were higher (P < 0.05) in the T-PE as compared with the normotensive control group. Higher placental triglycerides (P < 0.05) were observed in PT-PE group compared with T-PE group. Placental mRNA levels of peroxisome proliferator activated receptor α, carnitine palmitoyl transferase-1, cluster of differentiation 36 and lipoprotein lipases were lower (P < 0.05) in the PT-PE than normotensive control group. A negative association of mRNA levels of peroxisome proliferator activated receptor α (r = -0.246, P = 0.032; r = -0.308, P = 0.007, respectively), carnitine palmitoyl transferase-1 (r = -0.292, P = 0.011; r = -0.366, P = 0.001), lipoprotein lipases (r = -0.296, P = 0.010; r = -0.254, P = 0.028) with SBP and DBP was observed. There was a positive association of placental triglycerides (r = 0.244, P = 0.031) with DBP.

CONCLUSION

Women with preeclampsia exhibit higher lipid : lipoprotein ratios suggesting an atherogenic state particularly in women delivering preterm. Lower expression of genes involved in placental fatty acid oxidation and transport was also observed in preeclampsia.

Association of Maternal and Umbilical Cord Blood Lipid Parameters with Uterine and Fetal-Placental Blood Flow in Hypertensive and Normotensive Pregnancies

Purpose

There is a growing evidence suggesting that hypertensive disorders of pregnancy (HDP), especially preeclampsia, are associated with an increased risk of cardiometabolic disease for both mother and child later in life. The objective of this study was to determine the association of maternal and umbilical cord blood (UCB) lipid profiles with uterine and fetal-placental blood flow at the third trimester of pregnancy.

Patients and Methods

A total of 1,135 women were prospectively followed through pregnancy and data for 812 mother-newborn pairs, including 170 HDP ‎developed subjects and ‎642 ‎normotensive subjects were analyzed at the end of the study. Maternal serum and UCB triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and non-HDL-C levels were compared between HDP and normotensive groups; moreover, the association between lipid parameters and abnormal pulsatility indices (PIs) of uterine (UtA), umbilical (UA), and middle cerebral (MCA) arteries was evaluated with multivariate regression analysis models. The same analyses were carried out on subgroups of HDP (preeclampsia vs gestational hypertension).

Results

The mean TG, TC, LDL-C, and non-HDL-C levels were significantly higher in mother-newborn pairs of the HDP group compared to the normotensive group. In the HDP group, maternal TG and non-HDL-C levels were shown to have a significant association with abnormal UtA-PI (p<0.001 and p=0.039, respectively). We also found a positive significant association of fetal hypertriglyceridemia with abnormal UA-PI and MCA-PI in the HDP group (p=0.042 and p=0.021, respectively). However, no such associations were observed in normotensive mother-newborn pairs. Similar trends were observed in preeclamptic subjects after subgroup analysis.

Conclusion

Maternal TG and non-HDL-C levels as well as fetal TG level are significantly associated with disturbed uterine and fetal-placental blood flow in HDP.

Spontaneous superimposed preeclampsia: chronology and expression unveiled by temporal transcriptomic analysis

Preeclampsia (PE), a multifactorial pregnancy-specific syndrome accounting for up to 8% of pregnancy complications, is a leading cause of maternal and fetal morbidity and mortality. PE is also associated with long-term risk of hypertension and stroke for both mother and fetus. Currently, the only "cure" is delivery of the baby and placenta, largely because the pathogenesis of PE is not yet fully understood. PE is associated with impaired vascular remodeling at the maternal-fetal interface and placental insufficiency; however, specific factors contributing to this impairment have not been identified. To identify molecular pathways involved in PE, we examined temporal transcriptomic changes occurring within the uterus, uterine implantation sites, and placentae from the Dahl salt-sensitive (Dahl S) rat model of superimposed PE compared with Sprague Dawley (SD) rats. We hypothesized that targeted gene analysis and whole transcriptome analysis would identify genetic factors that contribute to development of the preeclamptic phenotype in the Dahl S rat and unveil novel biomarkers, therapeutic targets, and mechanistic pathways in PE. Quantitative real-time PCR (qRT-PCR) and whole genome microarray analysis were performed on isolated total RNA from uterus (day 0), uterine implantation sites (days 7 and 10), and placenta (days 14 and 20). We found 624, 332, 185, and 366 genes to be differentially expressed between Dahl S (PE) and SD (normal pregnancy) on days 0, 7, 10, and 14, respectively. Our data revealed numerous pathways that may play a role in the pathophysiology of spontaneous superimposed PE and allow for further investigation of novel therapeutic targets and biomarker development.

Newborn LpL (Ser447Stop, Asn291Ser) genotypes and the interaction with maternal genotypes influence the risk for different types of preeclampsia: modulating effect on lipid profile and pregnancy outcome

AIM

To establish that newborn Ser447Stop and Asn291Ser may have interactive effects with maternal genotypes on the plasma lipoprotein levels, risk of preeclampsia as well as on the prognosis of preeclampsia.

MATERIALS AND METHODS

Seventy preeclamptic women and 94 normotensive pregnant women, and their newborns were genotyped using PCR-RFLP methods.

RESULTS

The risk of mild and severe preeclampsia was 4 (p = 0.004) and 5.18 (p = 0.001), respectively, if both the mother and newborn were carriers of the Ser447/Ser477 genotype. If both the mother and newborn were carriers of the Asn291Ser variant, the risk to develop severe preeclampsia was 6.07 (p = 0.03). Women with mild and severe preeclampsia had higher TG (p < 0.001; p < 0.001) and LDL-C levels (p = 0.008; p < 0.001) if both the mother and newborn were carriers of the Ser447/Ser447 genotype. Women with severe preeclampsia had significantly higher TG (p = 0.03) and LDL-C levels (p = 0.037) if both the mother and newborn were carriers of Asn291Ser. Newborn/maternal LpL interaction had no statistically significant influence on pregnancy outcome.

CONCLUSIONS

The newborn/maternal LpL interaction influences the severity of preeclampsia and modulates the lipid profile particularly in severe preeclampsia.