Fatty acid oxidation changes and the correlation with oxidative stress in different preeclampsia-like mouse models

Decreased Fatty Acid Oxidation Gene Expression in Pre-Eclampsia According to the Onset and Presence of Intrauterine Growth Restriction

Mitochondrial fatty acid oxidation (FAO) is lower in placentas with pre-eclampsia. The aim of our study was to compare the placental mRNA expression of FAO enzymes in healthy pregnancies vs. different subgroups of pre-eclampsia according to the severity, time of onset, and the presence of intrauterine growth restriction (IUGR). By using real-time qPCR, we measured the mRNA levels of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD), medium-chain acyl-CoA dehydrogenase (MCAD), and carnitine palmitoyltransferases 1A and 2 (CPT1A, CPT2) on the maternal side (anchoring villi in the basal decidua) and on the fetal side (chorionic plate) of the placenta (n = 56). When compared to the controls, LCHAD, MCAD, and CPT2 mRNA had decreased in all pre-eclampsia subgroups globally and on the fetal side. On the maternal side, LCHAD mRNA was also lower in all pre-eclampsia subgroups; however, MCAD and CPT2 mRNA were only reduced in severe and early-onset disease, as well as CPT2 in IUGR (p < 0.05). There were no differences in CPT1A mRNA expression. We conclude that the FAO enzymes mRNA in the placenta was lower in pre-eclampsia, with higher reductions observed in severe, early-onset, and IUGR cases and more striking reductions on the fetal side.

Erythrocyte fatty acids and desaturase indices in early pregnancy are associated with risk of preeclampsia

Preeclampsia (PE) is a pregnancy disorder that may be associated with inadequate maternal nutrition. Fatty acids are vital for placental and fetal growth. Fatty acid desaturases, key enzymes influencing the metabolism of polyunsaturated fatty acids, are reported to be associated with cardiometabolic risk. Any imbalance in the levels of omega-3 and omega-6 fatty acids can result in increased inflammatory response. The current study reports the levels of erythrocyte fatty acids and desaturase index across gestation in women who develop PE (n = 108) and compares them with non-PE women (n = 216). Maternal erythrocyte fatty acids were measured at 4 time points during pregnancy (i.e., 11-14, 18-22, 26-28 weeks and at delivery) using gas chromatography. Maternal total erythrocyte saturated fatty acids and omega-6/omega-3 fatty acid ratio was higher in the PE group as compared to the non-PE group at 11-14 weeks and 18-22 weeks respectively. Maternal Δ5 desaturase index was lower while Δ6 desaturase index was higher in the PE group at 11-14 and 18-22 weeks. Maternal stearoyl CoA desaturase-18 (SCD-18) index was lower at 11-14 weeks and at delivery. These changes were mainly observed in the early onset PE (EOP) group. Δ6 desaturase index at 11-14 weeks predicted the risk of EOP. Imbalance in fatty acid levels and desaturase indices predate the clinical diagnosis of PE, indicating their role in its pathophysiology. Measurement of fatty acids and desaturase indices in early pregnancy merits evaluation as predictors of risk of PE.

LINC00240/miR-155 axis regulates function of trophoblasts and M2 macrophage polarization via modulating oxidative stress-induced pyroptosis in preeclampsia

Background

This study aimed to investigate the effects of LINC00240/miR-155/Nrf2 axis on trophoblast function and macrophage polarization in the pathogenesis of preeclampsia.

Methods

Bindings between LINC00240, miR-155 and Nrf2 were validated by dual luciferase reporter assay or RNA-immunoprecipitation. Cell proliferation, migration, invasion, and pyroptosis were detected by CCK-8, clone formation, wound healing, Transwell system, and flow cytometry, respectively. Macrophage polarization was tested by flow cytometry. The expression levels of LINC00240, miR-155, Nrf2, and oxidative stress and pyroptosis-related markers in in vitro and in vivo preeclampsia models were analyzed by qPCR, western blot, or ELISA assays. Blood pressure, urine protein levels, liver and kidney damages, and trophoblast markers in placenta tissues were further studied in vivo.

Results

Placenta tissues from preeclampsia patients and animals showed decreased LINC00240 and Nrf2 and increased miR-155 expression levels, and the decreased M2 macrophage polarization. LINC00240 directly bound and inhibited expression of miR-155, which then inhibited oxidative stress-induced pyroptosis, promoting proliferation, migration and invasion abilities of trophoblasts, and M2 macrophage polarization. Inhibition of miR-155 led to increased Nrf2 expression and similar changes as LINC00240 overexpression in trophoblast function and macrophage polarization. Overexpression of LINC00240 in in vivo preeclampsia model decreased blood pressure, urine protein, liver and kidney damages, increased fetal weight and length, and induced trophoblast function and M2 macrophage polarization.

Conclusion

LINC00240 inhibited symptoms of preeclampsia through regulation on miR-155/Nrf2 axis, which suppressed oxidative stress-induced pyroptosis to improve trophoblast function and M2 macrophage polarization. LINC00240 could be a potential therapeutic target for preeclampsia.

Effect of Placenta-Derived Mesenchymal Stromal Cells Conditioned Media on an LPS-Induced Mouse Model of Preeclampsia

We tested the pro-angiogenic and anti-inflammatory effects of human placenta-derived mesenchymal stromal cells (hPDMSCs)-derived conditioned media (CM) on a mouse model of preeclampsia (PE), a severe human pregnancy-related syndrome characterized by maternal hypertension, proteinuria, endothelial damage, inflammation, often associated with fetal growth restriction (FGR). At d11 of pregnancy, PE was induced in pregnant C57BL/6N mice by bacterial lipopolysaccharide (LPS) intravenous injection. At d12, 300 μL of unconditioned media (control group) or 300 μL PDMSCs-CM (CM group) were injected. Maternal systolic blood pressure was measured from 9 to 18 days of pregnancy. Urine protein content were analyzed at days 12, 13, and 17 of pregnancy. At d19, mice were sacrificed. Number of fetuses, FGR, fetal reabsorption, and placental weight were evaluated. Placentae were analyzed for sFlt-1, IL-6, and TNF-α gene and protein expressions. No FGR and/or reabsorbed fetuses were delivered by PDMSCs-CM-treated PE mice, while five FGR fetuses were found in the control group accompanied by a lower placental weight. PDMSCs-CM injection significantly decreased maternal systolic blood pressure, proteinuria, sFlt-1, IL-6, and TNF-α levels in PE mice. Our data indicate that hPDMSCs-CM can reverse PE-like features during pregnancy, suggesting a therapeutic role for hPDMSCs for the treatment 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.

Revisiting preeclampsia: a metabolic disorder of the placenta

Preeclampsia (PE) is a leading cause of maternal and neonatal mortality and morbidity worldwide, impacting the long-term health of both mother and offspring. PE has long been characterized by deficient trophoblast invasion into the uterus and consequent placental hypoperfusion, yet the upstream causative factors and effective interventional targets for PE remain unknown. Alterations in the metabolism of preeclamptic placentas are thought to result from placental ischemia, while disturbances of the metabolism and of metabolites in PE pathogenesis are largely ignored. In fact, as one of the largest fetal organs at birth, the placenta consumes a considerable amount of glucose and fatty acid. Increasing evidence suggests glucose and fatty acid exist as energy substrates and regulate placental development through bioactive derivates. Moreover, recent findings have revealed that the placental metabolism adapts readily to environmental changes, altering its response to nutrients and endocrine signals; this adaptability optimizes pregnancy outcomes by diversifying available carbon sources for energy production, hormone synthesis, angiogenesis, immune activation, and tolerance, and fetoplacental growth. These observations raise the possibility that carbohydrate and lipid metabolism abnormalities play a role in both the etiology and clinical progression of PE, sparking a renewed interest in the interrelationship between PE and metabolic dysregulation. This review will focus on key metabolic substrates and regulatory molecules in the placenta and aim to provide novel insights with respect to the metabolism's role in modulating placental development and functions. Further investigations from this perspective are poised to decipher the etiology of PE and suggest potential therapies.

Identifying key genes and drug screening for preeclampsia based on gene expression profiles

Preeclampsia (PE) is characterized by gestational hypertension and proteinuria, and is a leading cause of maternal death and perinatal morbidity globally. Although the exact cause of PE remains unclear, several studies have suggested a role for abnormal expression of multiple genes. The aim of the present study was to identify key genes and related pathways, and to screen for drugs that regulate these genes for potential PE therapy. The GSE60438 dataset was acquired from the Gene Expression Omnibus database to analyze differentially expressed genes (DEGs). By constructing a protein-protein interaction network and performing reverse transcription-quantitative PCR verification, proteasome 26S subunit, non-ATPase 14, prostaglandin E synthase 3 and ubiquinol-cytochrome c reductase core protein 2 were identified as key genes in PE. In addition, PE was found to be associated with ‘circadian rhythm’, ‘fatty acid metabolism’, ‘DNA damage response detection of DNA damage’, ‘regulation of DNA repair’ and ‘endothelial cell development’. Through connectivity map analysis of DEGs, furosemide and droperidol were suggested to be therapeutic drugs that may target the hub genes for PE treatment. Results analysis of GSEA were included in the discussion section of this article. In conclusion, the current study identified novel key genes associated with the onset of PE and potential drugs for PE treatment.

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.

Different Effects of Pravastatin on Preeclampsia-like Symptoms in Different Mouse Models

Background

Pravastatin (Pra) exerts protective effects on preeclampsia. Preeclampsia is a multifactorial and pathogenic pathway syndrome. The present study compared the effects of Pra on clinical manifestations of preeclampsia in different pathogenic pathways.

Methods

Two different preeclampsia-like mouse models used in this study were generated with Nω-nitro-L-arginine methyl ester (L-NAME) and used lipopolysaccharide (LPS) from day 7 of gestation, respectively. Pra treatment was administered on day 2 after the models were established in each group (L-NAME + Pra, LPS + Pra, and Control + Pra, n = 8) or normal saline (NS) for the control group (L-NAME + NS, LPS + NS, and Control + NS, n = 8). Maternal weight, serum lipids, the histopathological changes, and lipid deposition in the liver and placenta were observed. The pregnancy outcomes were compared. The blood pressure analysis was carried out on repeated measurements of variance. Student's t-test was used for comparing the two groups. The enumeration data were compared by Chi-square test.

Results

The mean arterial pressure (MAP) and 24-h urinary protein in the L-NAME + NS and LPS + NS groups were significantly higher than the Control + NS group (F = 211.05 and 309.92 for MAP, t = 6.63 and 8.63 for 24-h urinary protein; all P < 0.05) and reduced in the L-NAME + Pra group as compared to the L-NAME + NS group (F = 208.60 for MAP, t = 6.77 for urinary protein; both P < 0.05). Urinary protein was decreased in the LPS + Pra group as compared to the LPS + NS group (t = 5.33; P < 0.05), whereas MAP had no statistical significance (F = 3.37; P > 0.05). Compared to the Control + NS group, the placental efficiency in the L-NAME + NS and LPS + NS groups decreased significantly (t = 3.09 and 2.89, respectively; both P < 0.05); however, no significant difference was observed in L-NAME + Pra and LPS + Pra groups (t = 1.37 and 0.58, respectively; both P > 0.05). Free fatty acid was elevated in the L-NAME + NS group as compared to the Control + NS group (t = 3.99; P < 0.05) at day 18 of pregnancy and decreased in the L-NAME + Pra group as compared to the L-NAME + NS group (t = 3.28; P < 0.05); however, no significant change was observed in the LPS model (F = 0.32; P > 0.05).

Conclusion

This study suggested that Pra affected the clinical manifestations differently in preeclampsia-like mouse models generated in various pathogenic pathways.

Both maternal and placental toll-like receptor activation are necessary for the full development of proteinuric hypertension in mice

OBJECTIVE

Innate immune system activation and excessive inflammation contributes to hypertension during pregnancy (HTN-preg). Activation of Toll-like receptors (TLRs), the primary innate immune system sensor, is evident in women with HTN-preg and is sufficient to induce pregnancy-dependent, proteinuric hypertension in animals. However, whether HTN-preg is a maternal disease, a placental disease, or both is unclear. We hypothesized that activation of TLR3, the double-stranded RNA sensor, in both maternal systemic and placental cells would be necessary for the full development of HTN-preg in mice.

STUDY DESIGN

Various mating schemes generated pregnant mice that lacked TLR3 in maternal cells, paternally-derived placental cells, and both. Mice were then injected with a TLR3 agonist on days 13, 15, and 17 of pregnancy.

MAIN OUTCOME MEASURES

Blood pressure, urinary protein excretion, fetal development, maternal vascular endothelial function, and immune system activation were all assessed and compared between groups.

RESULTS

Pregnant mice lacking TLR3 in maternal cells as well as pregnant mice lacking TLR3 in placental cells had significantly attenuated increases in systolic blood pressure, urinary protein excretion, fetal demise, and endothelial dysfunction compared to wild-type pregnant mice following TLR3 activation. Pregnant mice lacking TLR3 in both maternal systemic and placental cells were completely resistant to the hypertension, proteinuria, fetal demise, endothelial dysfunction, splenomegaly, and increases in pro-inflammatory immune cells induced by TLR3 activation.

CONCLUSIONS

These data suggest that both maternal and placental TLR3 activation are crucial for the full development of HTN-preg and that TLR3 antagonists may be beneficial in some women with HTN-preg.

Effects of Rapamycin on Clinical Manifestations and Blood Lipid Parameters in Different Preeclampsia-like Mouse Models

Background:

The pathogenesis of some types of preeclampsia is related to fatty acid oxidation disorders. Rapamycin can regulate fatty acid metabolism. This study aimed to investigate the effects of rapamycin on the clinical manifestations and blood lipid parameters in different preeclampsia-like mouse models.

Methods:

Two preeclampsia-like mouse models and a control group were established: L-NA (injected with Nω-nitro-L-arginine methyl ester), LPS (injected with lipopolysaccharide), and the control group with normal saline (NS). The mouse models were established at preimplantation (PI), early- and late-pregnancy (EP, LP) according to the time of pregnancy. The administration of rapamycin (RA; L-NA+RA, LPS+RA, and NS+RA) or vehicle as controls (C; L-NA+C, LPS+C, NS+C) were followed on the 2^nd day after the mouse models’ establishment. Each subgroup consisted of eight pregnant mice. The mean arterial pressure (MAP), 24-h urinary protein, blood lipid, fetus, and placental weight were measured. The histopathological changes and lipid deposition of the liver and placenta were observed. Student's t-test was used for comparing two groups. Repeated measures analysis of variance was used for blood pressure analysis. Qualitative data were compared by Chi-square test.

Results:

The MAP and 24-h urinary protein in the PI, EP, and LP subgroups of the L-NA+C and LPS+C groups were significantly higher compared with the respective variables in the NS+C group (P < 0.05). The preeclampsia-like mouse models were established successfully. There was no significant difference in the MAP between the PI, EP, and LP subgroups of the L-NA+RA and L-NA+C groups and the LPS+RA and LPS+C groups. The 24-h urine protein levels in the PI and EP subgroups of the L-NA+RA group were significantly lower compared with the respective levels in the L-NA+C groups (1037 ± 63 vs. 2127 ± 593 μg; 976 ± 42 vs. 1238 ± 72 μg; both P < 0.05), also this effect appeared similar in the PI and EP subgroups of the LPS+RA and LPS+C groups (1022 ± 246 vs. 2141 ± 432 μg; 951 ± 41 vs. 1308 ± 30 μg; both P < 0.05). The levels of serum-free fatty acid (FFA) in the PI and EP subgroups of the L-NA+RA groups were significantly lower compared with the respective levels in the L-NA+C group (2.49 ± 0.44 vs. 3.30 ± 0.18 mEq/L; 2.23 ± 0.29 vs. 2.84 ± 0.14 mEq/L; both P < 0.05). The levels of triglycerides (TG) and total cholesterol in the PI subgroup of the L-NA+RA group were significantly lower compared with the respective levels in the L-NA+C (1.51 ± 0.16 vs. 2.41 ± 0.37 mmol/L; 2.11 ± 0.17 vs. 2.47 ± 0.26 mmol/L; both P < 0.05), whereas high-density lipoprotein serum concentration was significantly higher (1.22 ± 0.19 vs. 0.87 ± 0.15 mmol/L; P < 0.05) and low-density lipoprotein serum concentration did not exhibit a significant difference. There were no significant differences in the FFA of the PI, EP, and LP subgroups between the LPS+RA and the LPS+C groups. The levels of TG in the PI subgroup of the LPS+RA group were significantly lower compared with the respective levels in the LPS+C group (0.97 ± 0.05 vs. 1.22 ± 0.08 mmol/L; P < 0.05).

Conclusion:

Rapamycin can improve clinical manifestations and blood lipid profile in part of the preeclampsia-like mouse models.

Role of 3-Hydroxy Fatty Acid-Induced Hepatic Lipotoxicity in Acute Fatty Liver of Pregnancy

Acute fatty liver of pregnancy (AFLP), a catastrophic illness for both the mother and the unborn offspring, develops in the last trimester of pregnancy with significant maternal and perinatal mortality. AFLP is also recognized as an obstetric and medical emergency. Maternal AFLP is highly associated with a fetal homozygous mutation (1528G>C) in the gene that encodes for mitochondrial long-chain hydroxy acyl-CoA dehydrogenase (LCHAD). The mutation in LCHAD results in the accumulation of 3-hydroxy fatty acids, such as 3-hydroxy myristic acid, 3-hydroxy palmitic acid and 3-hydroxy dicarboxylic acid in the placenta, which are then shunted to the maternal circulation leading to the development of acute liver injury observed in patients with AFLP. In this review, we will discuss the mechanistic role of increased 3-hydroxy fatty acid in causing lipotoxicity to the liver and in inducing oxidative stress, mitochondrial dysfunction and hepatocyte lipoapoptosis. Further, we also review the role of 3-hydroxy fatty acids in causing placental damage, pancreatic islet β-cell glucolipotoxicity, brain damage, and retinal epithelial cells lipoapoptosis in patients with LCHAD deficiency.

Depletion of MHC class II invariant chain peptide or γ–δ T-cells ameliorates experimental preeclampsia

Excessive innate immune system activation and inflammation during pregnancy can lead to organ injury and dysfunction and preeclampsia (PE); however, the molecular mechanisms involved are unknown. We tested the hypothesis that Toll-like receptor (TLR) activation induces major histocompatibility complex (MHC) class II invariant chain peptide (CLIP) expression on immune cells, makes them pro-inflammatory, and are necessary to cause PE-like features in mice. Treatment with VG1177, a competitive antagonist peptide for CLIP in the groove of MHC class II, was able to both prevent and treat PE-like features in mice. We then determined that γ–δ T cells are critical for the development of PE-like features in mice since γ–δ T-cell knockout mice, like CLIP deficient mice, are resistant to developing PE-like features. Placentas from women with PE exhibit significantly increased levels of γ–δ T cells. These preclinical data demonstrate that CLIP expression and activated γ–δ T cells are responsible for the development of immunologic PE-like features and that temporarily antagonizing CLIP and/or γ–δ T cells may be a therapeutic strategy for PE.

Recent Advances in Immunity and Hypertension

Persistent immune system activation plays an important role in the development of various forms of hypertension. Activation of the innate immune system, inflammation, and subsequent adaptive immune system response causing end-organ injury and dysfunction ultimately leads to hypertension and its associated sequelae including coronary artery disease, heart failure, stroke, and chronic kidney disease. In this review, we will provide updates on the innate and adaptive immune cells involved in hypertension, the current understanding of how the immune system gets activated, and examine the recently discovered mechanisms involved in several forms of experimental hypertension.

Fatty acids profile in preterm Colostrum of Tunisian women. Association with selected maternal characteristics

Fatty acids (FA), especially arachidonic (AA, 20:4ω6) and docosahexaenoic (DHA, 22:6ω3) acids are critical for the health and development of infants. Colostrum FA composition has been examined in 101 lactating Tunisian women delivering prematurely using gas chromatography. Among polyunsaturated FA, linoleic acid predominated whereas each of the other polyunsaturated FA accounted for 1% or less of total FA. Colostrum AA and DHA contents were lower in women aged above 34 years compared to those less than 34 years. Preeclampsia was associated with lower DHA (0.40±0.22 vs. 0.53±0.27; p=0.018), but higher AA (1.14±0.44 vs. 0.93±0.30; p<0.006) and AA:DHA ratio (4.31±4.04 vs. 2.29±2.79; p<0.001). In multivariate analysis, colostrum DHA correlated with plasma DHA (β, 0.417; p=0.002), maternal age (β, -0.290; p=0.028) and preeclampsia (β, -0.270; p=0.042). Preterm colostrum FA profile in Tunisian women is comparable to those of other populations. Colostrum AA and DHA levels are altered in aged and pre-eclamptic women.

Differences in Liver Injury and Trophoblastic Mitochondrial Damage in Different Preeclampsia-like Mouse Models

Background:

Preeclampsia is a multifactorial disease during pregnancy. Dysregulated lipid metabolism may be related to some preeclampsia. We investigated the relationship between triglycerides (TGs) and liver injury in different preeclampsia-like mouse models and their potential common pathways.

Methods:

Preeclampsia-like models (Nw-nitro-L-arginine-methyl ester [L-NAME], lipopolysaccharide [LPS], apolipoprotein C-III [Apo] transgnic mice + L-NAME, β2 glycoprotein I [βGPI]) were used in four experimental groups: L-NAME (LN), LPS, Apo-LN and βGPI, respectively, and controls received saline (LN-C, LPS-C, Apo-C, βGPI-C). The first three models were established in preimplantation (PI), early-, mid- and late-gestation (EG, MG and LG). βGPI and controls were injected before implantation. Mean arterial pressure (MAP), 24-hour urine protein, placental and fetal weight, serum TGs, total cholesterol (TC) and pathologic liver and trophocyte changes were assessed.

Results:

MAP and proteinuria were significantly increased in the experimental groups. Placenta and fetal weight in PI, EP and MP subgroups were significantly lower than LP. Serum TGs significantly increased in most groups but controls. TC was not different between experimental and control groups. Spotty hepatic cell necrosis was observed in PI, EG, MG in LN, Apo-LN and βGPI, but no morphologic changes were observed in the LPS group. Similar trophoblastic mitochondrial damage was observed in every experimental group.

Conclusions:

Earlier preeclampsia onset causes a higher MAP and urine protein level, and more severe placental and fetal damage. Preeclampsia-like models generated by varied means lead to different changes in lipid metabolism and associated with liver injury. Trophoblastic mitochondrial damage may be the common terminal pathway in different preeclampsia-like models.

Correlation of long-chain fatty acid oxidation with oxidative stress and inflammation in pre-eclampsia-like mouse models

INTRODUCTION

Pre-eclampsia has been further recognized as a syndrome during pregnancy. Recent studies have found that long-chain fatty acid oxidation (FAO) disorders may be associated with some of pre-eclampsia. However, the mechanism remains unclear. In this study, we investigated the role of FAO and its relationship with oxidative stress and inflammatory signaling pathways in the pathogenesis of pre-eclampsia.

METHODS

PE-like groups included ApoC3 transgenic mice with abnormal fatty acid metabolism, classical PE-like models with injection of Nω-nitro-l-arginine-methyl ester (L-NA) or lipopolysaccharide (LPS), and antiphospholipid syndrome (APS) mouse model with β2GPI injection. The control group included wild-type mice with normal saline injection. Serum FFA was compared and placental and hepatic LCHAD, p47phox and NF-κB mRNA and protein were detected using real-time quantitative PCR and western blot.

RESULTS

FFA levels were significantly increased and were positively correlated with P47phox and NF-κB mRNA and protein expression in liver of all groups (p < 0.05), except LPS group (p < 0.05) as compared to control. LCHAD mRNA and protein expression in the liver and placenta was significantly increased in ApoC3+NS, ApoC3+L-NA, and β2GPI group, whereas decreased in L-NA group (p < 0.05) as compared to the control group. P47phox mRNA, NF-κB mRNA, and protein expression in the liver of all groups, except in LPS and in the placenta of β2GPI and L-NA groups, significantly increased (p < 0.05).

DISCUSSION

FAO disorders were involved in the pathogenesis of pre-eclampsia through oxidative stress and inflammatory endothelial cell injury.

Four Pathways Involving Innate Immunity in the Pathogenesis of Preeclampsia

The maternal innate immune system plays an important role both in normal pregnancy as well as hypertensive disorders of pregnancy including preeclampsia (PE). We propose four pathways that involve excessive innate immunity that lead to most forms of PE. Pre-existing endothelial dysfunction plus pregnancy leads to an excessive innate immune response resulting in widespread inflammation, placental and renal dysfunction, vasoconstriction, and PE. Placental dysfunction due to shallow trophoblast invasion, inadequate spiral artery remodeling, and/or low placental perfusion initiates an innate immune response leading to excessive inflammation, endothelial and renal dysfunction, and PE. A heightened innate immune system due to pre-existing or acquired infections plus the presence of a paternally derived placenta and semi-allogeneic fetus cause an excessive innate immune response which manifests as PE. Lastly, an abnormal and excessive maternal immune response to pregnancy leads to widespread inflammation, organ dysfunction, and PE. We discuss the potential role of innate immunity in each of these scenarios, as well as the overlap, and how targeting the innate immune system might lead to therapies for the treatment of PE.