Long-chain fatty acid oxidation changes in a β2 glycoprotein I-induced preeclampsia-like mouse model

The causal role of intestinal microbiome in development of pre-eclampsia

The correlation of pre-eclampsia (PE) and intestinal microbiome has been widely demonstrated in existing research, whereas their causal relationship has been rarely explored. The causal relationship between intestinal microbiome and PE risk was examined using large-scale genome-wide association studies (GWAS) summary statistics. To be specific, the causal microbial taxa for PE were identified using the two-sample Mendelian randomization (MR) method. The results were verified to be robust through comprehensive sensitive analyses, and the independence of causal relationship was ensured through novel multivariable MR analyses. The possibility of reverse relationships was ruled out through reverse-direction MR analyses. Lastly, the biofunction was explored through enrichment analysis, and a series of validations of PE results in a second GWAS were performed to confirm the results. After correction, four microbial taxa, including Streptococcus genus for PE (FDR q = 0.085), Olsenella genus for PE (FDR q = 0.085), Enterobacteriales order for PE (FDR q = 0.0134), and Akkermansia genus for PE (FDR q = 0.015), had a causal relationship to diverse joint PE (FDR q < 0.15). Moreover, when three different methods were employed on basis of the nominal significance (P < 0.05), five suggestive microbial taxa took on significance. The effect of heterogeneity and horizontal pleiotropy was excluded through sensitive analysis, and the possibility of horizontal pleiotropy of BMI was ruled out through multivariable MR analysis. The protective mechanism of the identified taxa against PE was illustrated through GO enrichment analysis and KEGG pathways. A number of microbial taxa had a causal relationship to PE. The result of this study provides more insights into intestinal microbiome in the pathology of PE.

Mendelian randomization study reveals a causal relationship between rheumatoid arthritis and risk for pre-eclampsia

Background

Epidemiological observational studies have investigated the relationship between rheumatoid arthritis(RA) and pre-eclampsia, but no consistent conclusions were obtained due to various limitations. Hence, we conducted a two-sample mendelian randomization analysis to evaluate the potential causal effect of RA on pre-eclampsia.

Methods

Summary-level statistics for RA were derived from a large-scale meta-analysis of datasets of genome-wide association studies(GWAS) which involved 14,361 cases and 43,923 controls. Moreover, summary statistics for pre-eclampsia or eclampsia were sourced from the Finn biobank which contained 3,903 cases and 114,735 controls. The inverse variance weighting (IVW) as well as other four effective methods including MR-Egger, weighted median, weighted mode, and simple mode were applied to deduce the potential causal relationships between RA and pre-eclampsia comprehensively.

Results

The two-sample MR analysis suggested a strong causal relationship between RA and pre-eclampsia[OR,1.05;95%CI, 1.01-1.09;p<0.05]. The OR estimates obtained from the weighted mode[OR,1.09;95%CI,1.03-1.15;p<0.01] and weighted median[OR,1.07;95%CI, 1.01-1.14;p<0.05] were similar to those from the IVW method, but there was no significant association observed in MR Egger and simple mode analysis.

Conclusion

This MR analysis provides evidence of a positive causal association between RA and pre-eclampsia genetically. Our findings highlight the importance of more intensive prenatal care and early intervention among pregnant women with RA to prevent potential adverse obstetric outcomes. Moreover, our study provides clues for risk factor identification and early prediction of pre-eclampsia.

Dietary Nutrition and Gut Microbiota Composition in Patients With Hypertensive Disorders of Pregnancy

Objective

The aim is to explore the intakes of dietary nutrients and the changes of gut microbiota composition among patients with hypertensive disorders of pregnancy (HDP) and provide a theoretical basis for the prevention and treatment of HDP.

Methods

This study was conducted at the Maternal and Child Health Care Hospital of Changzhou. A total of 170 pregnant women (72 patients with HDP in the case group and 98 healthy pregnant women in the control group) in the third trimester were enrolled. Dietary nutrient intakes were assessed through a food frequency questionnaire survey. Fresh fecal samples were aseptically collected, and 16S rDNA sequencing was conducted. The intakes of dietary nutrients and the diversity and relative abundance of gut microbiota were compared between pregnant women with and without HDP. A logistic regression model was used to investigate the association between differential gut microbial genera and the risk of HDP.

Results

The daily dietary intakes of vitamin A and vitamin C in pregnant women with HDP were significantly lower than those in the control group. The relative abundances of Bacteroidota, Bacteroidaceae, and Bacteroides were increased, and the relative abundances of Actinobacteriota, Lachnospiraceae, Prevotellaceae, Bifidobacteriaceae, Blautia, Prevotella, and Bifidobacterium were decreased in women with HDP compared with those in the controls. In addition, the relative abundance of Bifidobacterium was positively correlated with dietary intakes of vitamin C and vitamin E in patients with HDP. After adjustment for confounding factors, the odds ratio (95% confidence interval) of HDP for the relative abundance of Bifidobacterium was 0.899 (0.813, 0.995).

Conclusion

The composition of gut microbiota in pregnant women with HDP was significantly changed compared with that of healthy controls. The relative abundance of Bifidobacterium was negatively associated with HDP. Moreover, dietary vitamin C and gut Bifidobacterium may cooperatively contribute to reduce the risk of HDP.

Excessive backfat of sows at 109 d of gestation induces lipotoxic placental environment and is associated with declining reproductive performance

This study investigated the influence of sow backfat thickness at 109 d of gestation on sow and piglet performance. Data from 846 farrowing multiparous Yorkshire sows with parity from 3 to 5 were collected from a pig breeding farm. Sows were divided into six groups based on backfat thickness (≤16, 17-18, 19-20, 21-22, 23-24, and ≥25 mm) at 109 d of gestation. The evaluation of reproductive performance included the litter size, litter weight at birth and at weaning of 21 d, weight of placenta at parturition, placental efficiency, and sow daily feed intake of lactation. Parameters related to plasma lipids and the placental-lipid concentration were measured. Data were analyzed to determine the relationships among backfat thickness, placental lipids, and piglet performance. No differences were observed in the number of piglets born, born alive, after cross-foster, and at weaning among groups (P > 0.05). The litter weight at birth and weaning, piglet birth weight, weaning weight, placental efficiency, and the number and percentage of piglets born with weight of <800 g showed a significantly quadratic effect of the backfat thickness (P < 0.05). During lactation, sow daily feed intake linearly decreased with increased backfat thickness at 109 d of gestation (P < 0.05). Although triglycerides and low-density lipoprotein cholesterol (LDL-C) showed no significant difference, cholesterol and high-density lipoprotein cholesterol (HDL-C) and free fatty acid (FFA) concentrations significantly increased (P < 0.05) in both maternal and umbilical cord blood with increased backfat thickness of sow. Placental-lipid concentrations also significantly increased (P < 0.05) with increased backfat thickness. Moreover, backfat thickness and placental-lipid concentration were positively correlated with the number of piglets weighing <800 g (P < 0.01) but negatively correlated with birth weight, litter birth weight, and piglet weaned weight (P < 0.01). In conclusion, backfat thickness of sow at end of gestation correlates with birth and weaning weight of piglets. Placental ectopic lipid accumulation-induced lipotoxicity is likely responsible for such correlation.

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.

Sex differences in ischaemic stroke: potential cellular mechanisms

Stroke remains a leading cause of mortality and disability worldwide. More women than men have strokes each year, in part because women live longer. Women have poorer functional outcomes, are more likely to need nursing home care and have higher rates of recurrent stroke compared with men. Despite continued advancements in primary prevention, innovative acute therapies and ongoing developments in neurorehabilitation, stroke incidence and mortality continue to increase due to the aging of the U.S.

POPULATION

Sex chromosomes (XX compared with XY), sex hormones (oestrogen and androgen), epigenetic regulation and environmental factors all contribute to sex differences. Ischaemic sensitivity varies over the lifespan, with females having an "ischaemia resistant" phenotype that wanes after menopause, which has recently been modelled in the laboratory. Pharmacological therapies for acute ischaemic stroke are limited. The only pharmacological treatment for stroke approved by the Food and Drug Administration (FDA) is tissue plasminogen activator (tPA), which must be used within hours of stroke onset and has a number of contraindications. Pre-clinical studies have identified a number of potentially efficacious neuroprotective agents; however, nothing has been effectively translated into therapy in clinical practice. This may be due, in part, to the overwhelming use of young male rodents in pre-clinical research, as well as lack of sex-specific design and analysis in clinical trials. The review will summarize the current clinical evidence for sex differences in ischaemic stroke, and will discuss sex differences in the cellular mechanisms of acute ischaemic injury, highlighting cell death and immune/inflammatory pathways that may contribute to these clinical differences.

The role of anti-phospholipid antibodies in autoimmune reproductive failure

Anti-phospholipid antibodies (aPL) are autoantibodies that are associated with thrombosis and a range of pregnancy complications including recurrent pregnancy loss and pre-eclampsia. The three clinically relevant, well-characterized aPL are anti-cardiolipin antibodies, lupus anticoagulant and anti-beta-2-glycoprotein I (β2GPI) antibodies. aPL do not bind directly to phospholipids but instead bind to a plasma-binding ‘cofactor’. The most extensively studied cofactor is β2GPI, whose role in pregnancy is not fully elucidated. Although the pathogenicity of aPL in recurrent pregnancy loss is well established in humans and animal models, the association of aPL with infertility does not appear to be causative. aPL may exert their detrimental effects during pregnancy by directly binding trophoblast cells of the placenta, altering trophoblast signalling, proliferation, invasion and secretion of hormones and cytokines, and by increasing apoptosis. Heparin is commonly used to treat pregnant women with aPL; however, as thrombotic events do not occur in the placentae of all women with aPL, it may exert a protective effect by preventing the binding of aPL to β2GPI or by acting through non-thrombotic pathways. The aim of this review is to present evidence summarizing the current understanding of this field.

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.

Inventory of Novel Animal Models Addressing Etiology of Preeclampsia in the Development of New Therapeutic/Intervention Opportunities

Preeclampsia is a pregnancy-related disease afflicting 3-7% of pregnancies worldwide and leads to maternal and infant morbidity and mortality. The disease is of placental origin and is commonly described as a disease of two stages. A variety of preeclampsia animal models have been proposed, but all of them have limitations in fully recapitulating the human disease. Based on the research question at hand, different or multiple models might be suitable. Multiple animal models in combination with in vitro or ex vivo studies on human placenta together offer a synergistic platform to further our understanding of the etiology of preeclampsia and potential therapeutic interventions. The described animal models of preeclampsia divide into four categories (i) spontaneous, (ii) surgically induced, (iii) pharmacologically/substance induced, and (iv) transgenic. This review aims at providing an inventory of novel models addressing etiology of the disease and or therapeutic/intervention opportunities.

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.

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

Background

Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) expression is decreased in placenta of some cases of preeclampsia (PE) which may result in free fatty acid (FFA) increased. High FFA level will induce oxidative stress, so abnormal long-chain fatty acid-oxidation may participate in the pathogenesis of PE through oxidative stress pathway.

Methods

PE-like groups were ApoC3 transgenic mice with abnormal fatty acid metabolism, classical PE-like models with injection of Nw-nitro-L-arginine-methyl ester (L-NA) or lipopolysaccharide (LPS) and the antiphospholipid syndrome (APS) mouse model with β2GPI injection (ApoC3+NS, ApoC3+L-NA, L-NA, LPS and β2GPI groups). The control group was wild-type mice with normal saline injection. Except for β2GPI mice, the other mice were subdivided into pre-implantation (Pre) and mid-pregnancy (Mid) subgroups by injection time.

Results

All PE-like groups showed hypertension and proteinuria except ApoC3+NS mice only showed hypertension. Serum FFA levels increased significantly except in LPS group compared to controls (P<0.05). LCHAD mRNA and protein expression in the liver and placenta was significantly higher for ApoC3+NS, ApoC3+L-NA and β2GPI mice and lower for L-NA mice than controls (P<0.05) but did not differ between LPS mice and controls. P47phox mRNA and protein expression in the liver significantly increased in all PE-like groups except LPS group, while P47phox expression in the placenta only significantly increased in L-NA and β2GPI groups.

Conclusions

Abnormal long-chain fatty acid-oxidation may play a different role in different PE-like models and in some cases participate in the pathogenesis of PE through oxidative stress pathway.