CD4+ T cells cause renal and placental mitochondrial oxidative stress as mechanisms of hypertension in response to placental ischemia

Deciphering the preeclampsia-specific immune microenvironment and the role of pro-inflammatory macrophages at the maternal-fetal interface

Preeclampsia (PE), a major cause of maternal and perinatal mortality with highly heterogeneous causes and symptoms, is usually complicated by gestational diabetes mellitus (GDM). However, a comprehensive understanding of the immune microenvironment in the placenta of PE and the differences between PE and GDM is still lacking. In this study, cytometry by time of flight indicated that the frequencies of memory-like Th17 cells (CD45RA-CCR7+IL-17A+CD4+), memory-like CD8+ T cells (CD38+CXCR3-CCR7+Helios-CD127-CD8+) and pro-inflam Macs (CD206-CD163-CD38midCD107alowCD86midHLA-DRmidCD14+) were increased, while the frequencies of anti-inflam Macs (CD206+CD163-CD86midCD33+HLA-DR+CD14+) and granulocyte myeloid-derived suppressor cells (gMDSCs, CD11b+CD15hiHLA-DRlow) were decreased in the placenta of PE compared with that of normal pregnancy (NP), but not in that of GDM or GDM&PE. The pro-inflam Macs were positively correlated with memory-like Th17 cells and memory-like CD8+ T cells but negatively correlated with gMDSCs. Single-cell RNA sequencing revealed that transferring the F4/80+CD206- pro-inflam Macs with a Folr2+Ccl7+Ccl8+C1qa+C1qb+C1qc+ phenotype from the uterus of PE mice to normal pregnant mice induced the production of memory-like IL-17a+Rora+Il1r1+TNF+Cxcr6+S100a4+CD44+ Th17 cells via IGF1-IGF1R, which contributed to the development and recurrence of PE. Pro-inflam Macs also induced the production of memory-like CD8+ T cells but inhibited the production of Ly6g+S100a8+S100a9+Retnlg+Wfdc21+ gMDSCs at the maternal-fetal interface, leading to PE-like symptoms in mice. In conclusion, this study revealed the PE-specific immune cell network, which was regulated by pro-inflam Macs, providing new ideas about the pathogenesis of PE.

Identification and validation of key biomarkers associated with immune and oxidative stress for preeclampsia by WGCNA and machine learning

Background

Preeclampsia (PE), a major obstetric disorder marked by dysfunction in both placental and maternal vascular systems, continues to pose critical challenges in global maternal healthcare. This multisystem pregnancy complication contributes significantly to adverse perinatal outcomes and remains a leading cause of pregnancy-related morbidity worldwide. However, the available treatment options at present remain restricted. Our investigation employs an integrative bioinformatics approach to elucidate critical molecular signatures linked to the interplay between immunological dysregulation and oxidative stress mechanisms in PE pathogenesis.

Methods

In this study, we sourced the dataset from the GEO database with the aim of pinpointing differentially expressed genes (DEGs) between PE samples and control samples. Genes associated with oxidative stress were procured from the Genecards database. Next, we employed a comprehensive approach. This involved integrating WGCNA, GO and KEGG pathway analyses, constructing PPI networks, applying machine learning algorithms, performing gene GSEA, and conducting immune infiltration analysis to identify the key hub genes related to oxidative stress. Diagnostic potential of candidate biomarkers was quantitatively assessed through ROC curve modeling. Additionally, we constructed a miRNA - gene regulatory network for the identified diagnostic genes and predicted potential candidate drugs. In the final step, we validated the significant hub gene using independent external datasets, the hypoxia model of the HTR-8/SVneo cell line, and human placental tissue samples.

Results

At last, leptin (LEP) was identified as a core gene through screening and was found to be upregulated. The results of quantitative real-time polymerase chain reaction (qRT -PCR) and immunohistochemistry validation were consistent with those obtained from the datasets. KEGG analysis revealed that LEP was significantly enriched in "allograft rejection," "antigen processing," "ECM receptor interaction" and "graft versus host disease." GO analysis revealed that LEP was involved in biological processes such as "antigen processing and presentation," "peptide antigen assembly with MHC protein complex," "complex of collagen trimers," "MHC class II protein complex" and "mitochondrial protein containing complex." Moreover, immune cell analysis indicated that T follicular helper cells, plasmacytoid dendritic cells, neutrophils, and activated dendritic cells were positively correlated with LEP expression, whereas γδT cells, eosinophils, and central memory CD4+ T cells showed a negative correlation. These findings suggest that LEP influences the immune microenvironment of PE through its interaction with arious immune cells. In addition, 28 miRNAs and 15 drugs were predicted to target LEP. Finally, the overexpression of LEP was verified using independent external datasets, the hypoxia model of the HTR-8/SVneo cell line, and human placental tissue.

Conclusion

Through an integrated analytical framework employing WGCNA coupled with three distinct machine learning-driven phenotypic classification models, we discovered a pivotal regulatory gene. This gene has the potential to act as a novel diagnostic biomarker for PE. Moreover, it can be considered as a promising target for drug development related to PE. Notably, it shows a strong correlation with the immune microenvironment, suggesting its crucial role in the complex pathophysiological processes underlying PE.

Ferroptosis-related genes in preeclampsia: integrative bioinformatics analysis, experimental validation and drug prediction

INTRODUCTION

Preeclampsia (PE) is a severe pregnancy complication with limited early diagnostic and therapeutic options. Ferroptosis, an iron-dependent cell death pathway, has emerged as a potential mechanism in PE pathogenesis. This study investigated ferroptosis-related genes (FRGs) in PE to identify diagnostic biomarkers and therapeutic targets.

METHODS

Differentially expressed genes were identified from GEO databases and intersected with FRGs. Hub genes were selected using RandomForest and LASSO algorithms. Their diagnostic potential was evaluated through ROC analysis. Regulatory networks were constructed using transcription factors, microRNAs and potential drug targets. Hub gene expression was validated through immunohistochemistry, Western blot, and RT-qPCR in placental tissues and hypoxic trophoblasts.

RESULTS

We identified 25 ferroptosis-related differentially expressed genes enriched in ferroptosis and HIF-1 pathways. Four hub genes (NDRG1, P4HA1, LDHA, and IDO1) showed high diagnostic efficiency (AUC=0.9182). Immune cell analysis revealed altered levels of plasma cells, CD8+ T cells, Tregs, monocytes, and M2 macrophages in PE, correlating significantly with hub gene expression. We identified 84 mRNA-miRNA and 119 mRNA-TF interactions. Among 19 potential drugs, Tetrahydro-NAD showed promising targeting potential. Experimental validation confirmed elevated expression of NDRG1, P4HA1, and LDHA, and decreased IDO1 in PE tissues and hypoxic conditions.

DISCUSSION

This study identified four FRGs as potential PE biomarkers and therapeutic targets, providing new insights into PE pathogenesis through integrated bioinformatics and experimental validation. These findings may facilitate early PE diagnosis and treatment development.

Intact NOX2 in T Cells Mediates Pregnancy-Induced Renal Damage in Dahl SS Rats

BACKGROUND

Hypertensive disorders of pregnancy are associated with increased risk for cardiovascular disease, renal disease, and mortality. While the exact mechanisms remain unclear, T cells and reactive oxygen species have been implicated in its pathogenesis. We utilized Dahl salt-sensitive (SS), SSCD247-/- (Dahl SS CD247 knockout rat; lacking T cells), and SSp67phox-/- (Dahl SS p67phox [NOX2 (NADPH [nitcotinamide adenine dinucleotide phosphate] oxidase 2)] knockout rat; lacking NOX2) rats to investigate these mechanisms in primigravida and multigravida states.

METHODS

We assessed blood pressure and renal damage phenotypes in SS, SSCD247-/-, and SSp67phox-/- rats during primigravida and multigravida states. To investigate the contribution of NOX2 in T cells, we performed adoptive transfers of splenocytes or cluster of differentiation (CD)4+ T cells from either SS or SSp67phox-/- donors into SSCD247-/- recipients to determine pregnancy-specific alterations in phenotype.

RESULTS

Multigravida SS rats developed significant pregnancy-induced renal damage and renal functional impairment associated with elevated maternal mortality rates, whereas deletion of T cells or NOX2 garnered protection. During primigravida states, this attenuation in renal damage was observed, with the greatest protection in the SSp67phox-/- rat. To demonstrate that NOX2 in T cells contributes to adverse pregnancy phenotypes, adoptive transfer of SS splenocytes into SSCD247-/- rats resulted in significant pregnancy-induced renal damage, whereas transfer of SSp67phox-/- splenocytes garnered protection. Specifically, the transfer of SS CD4+ T cells resulted in pregnancy-induced proteinuria and increases in uterine artery resistance index, an effect not seen with the transfer of SSp67phox-/- CD4+ T cells.

CONCLUSIONS

T cells and NOX2-derived reactive oxygen species, thus, contribute to end-organ damage in both primigravida and multigravida pregnancies in the SS rat leading to increases in maternal mortality.

Analysis of the evolution of placental oxidative stress research from a bibliometric perspective

Background

Research on placental oxidative stress is pivotal for comprehending pregnancy-related physiological changes and disease mechanisms. Despite recent advancements, a comprehensive review of current status, hotspots, and trends remains challenging. This bibliometric study systematically analyzes the evolution of placental oxidative stress research, offering a reference for future studies.

Objective

To conduct a comprehensive bibliometric analysis of the literature on placental oxidative stress to identify research hotspots, trends, and key contributors, thereby providing guidance for future research.

Methods

Relevant data were retrieved from the Web of Science Core Collection database and analyzed using VOSviewer, CiteSpace, and the bibliometrix package. An in-depth analysis of 4,796 publications was conducted, focusing on publication year, country/region, institution, author, journal, references, and keywords. Data collection concluded on 29 April 2024.

Results

A total of 4,796 papers were retrieved from 1,173 journals, authored by 18,835 researchers from 4,257 institutions across 103 countries/regions. From 1991 to 2023, annual publications on placental oxidative stress increased from 7 to 359. The United States (1,222 publications, 64,158 citations), the University of Cambridge (125 publications, 13,562 citations), and Graham J. Burton (73 publications, 11,182 citations) were the most productive country, institution, and author, respectively. The journal Placenta had the highest number of publications (329) and citations (17,152), followed by the International Journal of Molecular Sciences (122 publications). The most frequent keywords were "oxidative stress," "expression," "pregnancy," "preeclampsia," and "lipid peroxidation." Emerging high-frequency keywords included "gestational diabetes mellitus," "health," "autophagy," "pathophysiology," "infection," "preterm birth," "stem cell," and "inflammation."

Conclusion

Over the past 3 decades, research has concentrated on oxidative stress processes, antioxidant mechanisms, pregnancy-related diseases, and gene expression regulation. Current research frontiers involve exploring pathophysiology and mechanisms, assessing emerging risk factors and environmental impacts, advancing cell biology and stem cell research, and understanding the complex interactions of inflammation and immune regulation. These studies elucidate the mechanisms of placental oxidative stress, offering essential scientific evidence for future intervention strategies, therapeutic approaches, and public health policies.

Hypertension and Cognitive Dysfunction in a Pregnant Rat Model of PE; a Role for CD4+ T Cells

OBJECTIVE

Preeclampsia (PE) is associated with hypertension (HTN) during pregnancy and activated CD4+ T cells, inflammatory cytokines, and autoantibodies to the angiotensin II type I receptor (AT1-AA). Having had COVID-19 (CV) during pregnancy is associated with an increased incidence of a PE-like phenotype. Both PE and CV have long-lasting neurological implications and studies show that nonpregnant COVID patients produce AT1-AA. We have shown that CD4+ T cells from PE women cause a PE phenotype in nude athymic rats. In this study, we sought to examine the role of CD4+ T cells from PE with a CV History (Hx) to contribute to a PE phenotype and to determine the importance of CD4+ T cells in cognitive dysfunction during pregnancy.

METHODS

At delivery, blood and placentas were collected, and one million placental CD4+ T cells from each PE and each normotensive patient, with (NT) or without (NP) a CV (Hx) during pregnancy, were isolated, purified, and injected i.p. into a gestational day (GD) 12 pregnant nude athymic rat (one patient/rat). At GD19, blood pressure (MAP) and circulating factors were assessed in recipient rats. Cognitive function and memory were assessed using Novel Object Recognition and Barnes Maze tests, respectively. Placental ACE-2 activity and AT1-AA were measured from COVID Hx patients. A one- or two-way ANOVA with Bonferroni's multiple comparisons test was used for statistical analysis.

RESULTS

Blood pressure was increased in patients with PE, with or without COVID, compared to NT patients. There were no significant changes in placental ACE activity in patients with COVID Hx with or without PE. AT1-AA was elevated in PE patients and in both PE and NT COVID Hx compared to control NP. In pregnant recipient rats, MAP increased in CV Hx PE (113 ± 2, n = 8) compared to CV Hx NT (101 ± 5, n = 6). PE and PE CV Hx CD4+ T Cell recipient rats exhibited impaired memory and cognitive dysfunction (p < 0.05), compared to control groups. Recipient rats of PE CV Hx CD4+ T cells had elevated AT1-AA compared to NT CV Hx recipients. Both COVID Hx groups and recipients of PE CD4+ T cells had elevated TNF alpha compared to NP.

CONCLUSION

Our findings indicate that pregnant patients with a Hx of COVID during pregnancy produce AT1-AA, with or without PE. Recipients of CD4+ T cells from PE with or without a CV Hx during pregnancy cause HTN and elevated AT1-AA. TNF-α is elevated in PE and in CV Hx NT and PE recipients. Interestingly, recipients of T cells from PE patients with or without a Hx of CV had worse cognitive function during pregnancy, compared to recipient rats of NP CD4+ T cells. These data demonstrate the importance of CD4+ T cells in HTN and impaired neurological function during PE in the presence or absence of a prior COVID-19 infection during pregnancy.

Reduced uterine perfusion pressure as a model for preeclampsia and fetal growth restriction in murine: a systematic review and meta-analysis

The reduced uterine perfusion pressure (RUPP) model is frequently used to study preeclampsia and fetal growth restriction. An improved understanding of influential factors might improve reproducibility and reduce animal use considering the variability in RUPP phenotype. We performed a systematic review and meta-analysis by searching Medline and Embase (until 28 March, 2023) for RUPP studies in murine. Primary outcomes included maternal blood pressure (BP) or proteinuria, fetal weight or crown-rump length, fetal reabsorptions, or antiangiogenic factors. We aimed to identify influential factors by meta-regression analysis. We included 155 studies. Our meta-analysis showed that the RUPP procedure results in significantly higher BP (MD = 24.1 mmHg; [22.6; 25.7]; n = 148), proteinuria (SMD = 2.3; [0.9; 3.8]; n = 28), fetal reabsorptions (MD = 50.4%; [45.5; 55.2]; n = 42), circulating soluble FMS-like tyrosine kinase-1 (sFlt-1) (SMD = 2.6; [1.7; 3.4]; n = 34), and lower fetal weight (MD = -0.4 g; [-0.47; -0.34]; n = 113. The heterogeneity (variability between studies) in primary outcomes appeared ≥90%. Our meta-regression identified influential factors in the method and time point of BP measurement, randomization in fetal weight, and type of control group in sFlt-1. The RUPP is a robust model considering the evident differences in maternal and fetal outcomes. The high heterogeneity reflects the observed variability in phenotype. Because of underreporting, we observed reporting bias and a high risk of bias. We recommend standardizing study design by optimal time point and method chosen for readout measures to limit the variability. This contributes to improved reproducibility and thereby eventually improves the translational value of the RUPP model.

Abatacept Decreases Renal T-cell Infiltration and Renal Inflammation and Ameliorates Progressive Renal Injury in Obese Dahl Salt-sensitive Rats Before Puberty

ABSTRACT

Prepubertal obesity is growing at an alarming rate and is now considered a risk factor for renal injury. Recently, we reported that the early development of renal injury in obese Dahl salt-sensitive (SS) leptin receptor mutant (SS LepR mutant) rats was associated with increased T-cell infiltration and activation before puberty. Therefore, the current study investigated the effect of inhibiting T-cell activation with abatacept on the progression of renal injury in young obese SS LepR mutant rats before puberty. Four-week-old SS and SS LepR mutant rats were treated with IgG or abatacept (1 mg/kg; ip, every other day) for 4 weeks. Abatacept reduced the renal infiltration of T cells by almost 50% in SS LepR mutant rats. Treatment with abatacept decreased the renal expression of macrophage inflammatory protein-3 alpha while increasing IL-4 in SS LepR mutant rats without affecting SS rats. While not having an impact on blood glucose levels, abatacept reduced hyperinsulinemia and plasma triglycerides in SS LepR mutant rats without affecting SS rats. We did not observe any differences in the mean arterial pressure among the groups. Proteinuria was markedly higher in SS LepR mutant rats than in SS rats throughout the study, and treatment with abatacept decreased proteinuria by about 40% in SS LepR mutant rats without affecting SS rats. We observed significant increases in glomerular and tubular injury and renal fibrosis in SS LepR mutant rats versus SS rats, and chronic treatment with abatacept significantly reduced these renal abnormalities in SS LepR mutant rats. These data suggest that renal T-cell activation contributes to the early progression of renal injury associated with prepubertal obesity.

AT1-AA Is Produced in Offspring in Response to Placental Ischemia and Is Lowered by B-Cell Depletion Without Compromising Overall Offspring Health

BACKGROUND

Preeclampsia, new-onset hypertension during pregnancy alongside other organ dysfunction, is the leading cause of mortality for the mother and low birth weight for the baby. Low birth weight contributes to high risk of cardiovascular disorders later in life. Women with preeclampsia have activated B cells producing agonistic autoantibodies to AT1-AA (angiotensin II type I receptor). We hypothesize that rituximab, a B cell-depleting chemotherapeutic, will deplete maternal B cells in reduced uterine perfusion pressure (RUPP) rats without worsening the effect of placental ischemia on pup growth and survival.

METHODS AND RESULTS

To test this hypothesis, the RUPP procedure was performed, and rituximab was continuously infused via miniosmotic pump. Maternal blood and tissues were collected. A separate group of dams were allowed to deliver, pup weights were recorded, and at 4 months of age, tissues were collected from offspring. Immune cells were measured via flow cytometry, and AT1-AA was quantified using a contraction bioassay. Blood pressure increased in RUPP rats and was normalized with rituximab treatment. RUPP offspring also had increased circulating B cells, cytolytic natural killer cells, and increased circulating AT1-AA, which were normalized with maternal rituximab treatment. This is the first study to analyze the AT1-AA in RUPP offspring, which was normalized with rituximab.

CONCLUSIONS

Our findings indicate that perinatal rituximab lowers maternal mean arterial pressure in RUPP rats and improves birth weight, circulating AT1-AA, and circulating natural killer cells, indicating that rituximab improves adverse fetal outcomes in response to placental ischemia.

Inhibiting B cell activating factor attenuates preeclamptic symptoms in placental ischemic rats

PROBLEM

Preeclampsia (PE), new-onset hypertension during pregnancy, is associated with a pro-inflammatory state with activated T cells, cytolytic natural killer (NK) cells, dysregulated complement proteins, and B cells secreting agonistic autoantibodies to the angiotensin II type-1 receptor (AT1-AA). The reduced uterine perfusion pressure (RUPP) model of placental ischemia recapitulates these features of PE. Blocking CD40L-CD40 communication between T and B cells or B cell depletion with Rituximab prevents hypertension and AT1-AA production in RUPP rats. This suggests that T cell-dependent B cell activation contributes to the hypertension and AT1-AA associated with PE. B2 cells maturing into antibody producing plasma cells are the product of T cell-dependent B cell-interactions and B cell Activating Factor (BAFF) is an integral cytokine in the development of B2 cells specifically. Thus, we hypothesize that BAFF blockade will selectively deplete B2 cells, therefore reducing blood pressure, AT1-AA, activated NK Cells, and complement in the RUPP rat model of PE.

METHOD OF STUDY

Gestational Day (GD) 14 pregnant rats underwent the RUPP procedure, and a subset were treated with 1 mg/kg Anti-BAFF antibodies via jugular catheters. On GD19, blood pressure was measured, B cells and NK cells were measured by flow cytometry, AT1-AA was measured by cardiomyocyte bioassay, and complement activation was measured by ELISA.

RESULTS

Anti-BAFF therapy attenuated hypertension, AT1-AA, NK cell activation, and APRIL levels in RUPP rats without negatively impacting fetal outcomes.

CONCLUSIONS

This study demonstrates that B2 cells contribute to hypertension, AT1-AA, and NK cell activation in response to placental ischemia during pregnancy.

The role of immune cells and mediators in preeclampsia

Preeclampsia is a hypertensive disorder of major concern in pregnancy than can lead to intrauterine growth restriction, placental abruption and stillbirth. The pathophysiology of preeclampsia is multifactorial, including not only kidney dysfunction but also endothelial dysfunction, as the maternal endothelium becomes exposed to placental factors that are released into the circulation and increase systemic levels of vasoconstrictors, oxidative stress, anti-angiogenic factors and inflammatory mediators. Importantly, inflammation can lead to insufficient placental perfusion and low birthweight in offspring. Various innate and adaptive immune cells and mediators have been implicated in the development of preeclampsia, in which oxidative stress is associated with activation of the maternal inflammatory response. Immune cells such as regulatory T cells, macrophages, natural killer cells, and neutrophils are known to have major causative roles in the pathology of preeclampsia, but the contributions of additional immune cells such as B cells, inflammatory cytokines and anti-angiotensin II type 1 receptor autoantibodies are also now recognized. Immunological interventions, therefore, have therapeutic potential in this disease. Here, we provide an overview of the immune responses that are involved in the pathogenesis of preeclampsia, including the role of innate and adaptive immune cells and mediators.

Setting a stage: Inflammation during preeclampsia and postpartum

Preeclampsia (PE) is a leading cause of maternal and fetal mortality worldwide. The immune system plays a critical role in normal pregnancy progression; however, inappropriate inflammatory responses have been consistently linked with PE pathophysiology. This inflammatory phenotype consists of activation of the innate immune system, adaptive immune system, and increased inflammatory mediators in circulation. Moreover, recent studies have shown that the inflammatory profile seen in PE persists into the postpartum period. This manuscript aims to highlight recent advances in research relating to inflammation in PE as well as the inflammation that persists postpartum in women after a PE pregnancy. With the advent of the COVID-19 pandemic, there has been an increase in obstetric disorders associated with COVID-19 infection during pregnancy. This manuscript also aims to shed light on the relationship between COVID-19 infection during pregnancy and the increased incidence of PE in these women.

B2 cells contribute to hypertension and natural killer cell activation possibly via AT1-AA in response to placental ischemia

Preeclampsia, new onset hypertension during pregnancy, is associated with activated T helper cells (Th) and B cells secreting agonistic autoantibodies against the angiotensin II type 1 receptor (AT1-AA). The reduced uterine perfusion pressure (RUPP) model of placental ischemia recapitulates these characteristics. We have shown that Th-B cell communication contributes to AT1-AA and symptoms of preeclampsia in the RUPP rat. B2 cells are classical B cells that communicate with Th cells and are then transformed into memory B cells. We hypothesize that B2 cells cause hypertension, natural killer (NK) cell activation, and complement activation during pregnancy through the production of AT1-AA. To test this hypothesis, total splenic B cells and B2 cells were isolated from normal pregnant (NP) or RUPP rats on gestational day (GD)19 and adoptively transferred into GD12 NP rats. A group of recipient rats was treated with a specific inhibitor peptide of AT1-AA. On GD19, mean arterial pressure was measured, tissues were collected, activated NK cells were measured by flow cytometry, and AT1-AA was measured by cardiomyocyte assay. NP recipients of RUPP B cells or RUPP B2 cells had increased mean arterial pressure, AT1-AA, and circulating activated NK cells compared with recipients of NP B cells. Hypertension in NP recipients of RUPP B cells or RUPP B2 was attenuated with AT1-AA blockade. This study demonstrates that B cells and B2 cells from RUPP rats cause hypertension and increased AT1-AA and NK cell activation in response to placental ischemia during pregnancy.NEW & NOTEWORTHY This study demonstrates that placental ischemia-stimulated B2 cells induce hypertension and circulating natural killer cell activation and angiotensin II type 1 receptor production in normal pregnant rats.

The Increased Risk of Hypertension Caused by Irrational Dietary Pattern May Be Associated with Th17 Cell in the Middle-Aged and Elderly Rural Residents of Beijing City, Northern China: A 1:1 Matched Case-Control Study

An irrational diet has been widely considered as one of the vital risk factors of hypertension. Previous studies have indicated that immune dysfunction may be involved in the pathogenic process of hypertension, while fewer studies have mentioned whether CD4+ T cells are involved in the association between dietary pattern and hypertension. This present 1:1 matched case-control study was conducted to analyze the association among dietary pattern, CD4+ T cells and hypertension. A total of 56 patients with diagnosed hypertension and 56 subjects without diagnosed hypertension in the rural area of Beijing City, northern China, were matched by age and gender, and then classified into a case group and a control group, respectively. Compared with the control group, higher frequencies of pro-inflammatory CD4+ T cells, such as Th1, Th1(IFN-γ), Th17(IL-17A), and Th1/17 (IFN-γ/IL-17A), were found in the case group (p < 0.05). A significantly higher level of circulating IL-17A was also found in the case group (7.4 pg/mL vs. 8.2 pg/mL, p < 0.05). Five dietary patterns were identified using exploratory factor analysis. An irrational dietary pattern, characterized by high-factor loadings of refined wheat (0.65), meat (0.78), poultry (0.76), and alcoholic beverage (0.73), was positively associated with SBP (β = 5.38, 95%CI = 0.73~10.03, p < 0.05) in the multiple linear regression model with the adjustment of potential covariates. The other dietary patterns showed no significant association with blood pressure. Furthermore, meat, processed meat, and animal viscera were positively correlated with the peripheral Th17 or Th1/17. In conclusion, the irrational dietary pattern characterized by refined wheat, meat, poultry, and alcoholic beverage, was positively correlated with blood pressure, and may increase the risk of hypertension in the rural area of Beijing, northern China. Th17, a subset of the CD4+ T helper cells, may be involved in the association between irrational dietary pattern and hypertension.

The Role of Different Lymphoid Cell Populations in Preeclampsia Pathophysiology

Preeclampsia (PE), new-onset hypertension during pregnancy, affects up to 10% of pregnancies worldwide. Despite being the leading cause of maternal and fetal morbidity and mortality, PE has no cure beyond the delivery of the fetal-placental unit. Although the exact pathogenesis of PE is unclear, there is a strong correlation between chronic immune activation; intrauterine growth restriction; uterine artery resistance; dysregulation of the renin-angiotensin system. Which contributes to renal dysfunction; and the resulting hypertension during pregnancy. The genesis of PE is thought to begin with insufficient trophoblast invasion leading to reduced spiral artery remodeling, resulting in decreased placental perfusion and thereby causing placental ischemia. The ischemic placenta releases factors that shower the endothelium and contribute to peripheral vasoconstriction and chronic immune activation and oxidative stress. Studies have shown imbalances in proinflammatory and anti-inflammatory cell types in women with PE and in animal models used to examine mediators of a PE phenotype during pregnancy. T cells, B cells, and natural killer cells have all emerged as potential mediators contributing to the production of vasoactive factors, renal and endothelial dysfunction, mitochondrial dysfunction, and hypertension during pregnancy. The chronic immune activation seen in PE leads to a higher risk for other diseases, such as cardiovascular disease, CKD, dementia during the postpartum period, and PE during a subsequent pregnancy. The purpose of this review is to highlight studies demonstrating the role that different lymphoid cell populations play in the pathophysiology of PE. Moreover, we will discuss treatments focused on restoring immune balance or targeting specific immune mediators that may be potential strategies to improve maternal and fetal outcomes associated with PE.

Placental CD4+ T cells from preeclamptic patients cause autoantibodies to the angiotensin II type I receptor and hypertension in a pregnant rat model of preeclampsia

Preeclampsia (PE) is a hypertensive disorder of pregnancy associated with activated CD4+ T cells and autoantibodies to angiotensin II type 1 receptor (AT1-AA). We have previously shown that CD4+ T cells isolated from women with PE cause hypertension, increased tumor necrosis factor alpha (TNF-α), endothelin-1, and soluble fms-like tyrosine kinase-1 (sFlt-1) when injected into pregnant nude-athymic rats compared to CD4+ T cells from normal pregnant (NP) women. However, the role of PE CD4+ T cells to cause AT1-AA as a mechanism of hypertension is not known. Aim: Our goal was to determine if PE CD4+ T cells stimulate AT1-AA in pregnant nude-athymic rats. CD4+ T cells were isolated from human NP and PE placentasand injected into nude-athymic rats on gestational day (GD) 12. In order to examine the role of the PE CD4+ T cells to stimulate B cell secretion of AT1-AA, a subset of the rats receiving PE CD4+ T cells were treated with rituximab on GD 14 or anti-CD40 ligand (anti-CD40L) on GD 12. On GD 19, mean arterial pressure (MAP) and tissues were obtained MAP [114 ± 1 mmHg (n = 9)] and AT1-AA [19.8 ± 0.9 beats per minute (bpm, n = 4)] were increased in NP nude + PE CD4+ T cells compared to NP nude + NP CD4+ T cells [98 ± 2 mmHg (n = 7, P < 0.05) and 1.3 ± 0.9 bpm (n = 5, P < 0.05)]. Rituximab (103 ± 2 mmHg, n = 3, P < 0.05) and anti-CD40L (102 ± 1 mmHg, n = 3, P < 0.05) lowered MAP compared to NP nude + PE CD4+ T cells. Circulating a proliferation-inducing ligand (APRIL) and placental angiotensin-converting enzyme 2 (ACE-2) activity was increased in response to PE CD4+ T cells. These results show that placental CD4+ T cells play an important role in the pathophysiology of PE, by activating B cells secreting AT1-AA to cause hypertension during pregnancy.

Is Mitochondrial Oxidative Stress a Viable Therapeutic Target in Preeclampsia?

Despite considerable research efforts over the past few decades, the pathology of preeclampsia (PE) remains poorly understood with no new FDA-approved treatments. There is a substantial amount of work being conducted by investigators around the world to identify targets to develop therapies for PE. Oxidative stress has been identified as one of the crucial players in pathogenesis of PE and has garnered a great deal of attention by several research groups including ours. While antioxidants have shown therapeutic benefit in preclinical models of PE, the clinical trials evaluating antioxidants (vitamin E and vitamin C) were found to be disappointing. Although the idea behind contribution of mitochondrial oxidative stress in PE is not new, recent years have seen an enormous interest in exploring mitochondrial oxidative stress as an important pathological mediator in PE. We and others using animals, cell models, and preeclamptic patient samples have shown the evidence for placental, renal, and endothelial cell mitochondrial oxidative stress, and its significance in PE. These studies offer promising results; however, the important and relevant question is can we translate these results into clinical efficacy in treating PE. Hence, the purpose of this review is to review the existing literature and offer our insights on the potential of mitochondrial antioxidants in treating PE.

Progesterone Induced Blocking Factor Reduces Hypertension and Placental Mitochondrial Dysfunction in Response to sFlt-1 during Pregnancy

Preeclampsia (PE) is characterized by new onset hypertension in association with placental ischemia, reduced fetal weight, elevated soluble fms-like tyrosine kinase-1 (sFlt-1), and placental mitochondrial (mt) dysfunction and oxidative stress (ROS). Progesterone induced blocking factor (PIBF) is a product of progesterone signaling that blocks inflammatory processes and we have previously shown PIBF to lower mean arterial blood pressure (MAP) and sFlt-1 in a rat model of PE. Infusion of sFlt-1 causes hypertension and many characteristics of PE in pregnant rodents, however, its role in causing mt dysfunction is unknown. Therefore, we hypothesize that PIBF will improve mt function and MAP in response to elevated sFlt-1 during pregnancy. We tested our hypothesis by infusing sFlt-1 via miniosmotic pumps in normal pregnant (NP) Sprague-Dawley rats (3.7 μg·kg-1·day-1) on gestation days (GD) 13-19 in the presence or absence of PIBF (2.0 µg/mL) injected intraperitoneally on GD 15 and examined mean arterial blood pressure (MAP) and placental mt ROS on GD 19. sFlt-1 increased MAP to 112 + 2 (n = 11) compared to NP rats (98 + 2 mmHg, n = 15, p < 0.05), which was lowered in the presence of sFlt-1 (100 + 1 mmHg, n = 5, p < 0.05). Placental mtATP was reduced in sFlt-1 infused rats versus NP controls, but was improved with PIBF. Placental mtROS was elevated with sFlt-1 compared to NP controls, but was reduced with PIBF. Sera from NP + sFlt-1 increased endothelial cell mtROS, which was attenuated with PIBF. These data demonstrate sFlt-1 induced HTN during pregnancy reduces placental mt function. Importantly, PIBF improved placental mt function and HTN, indicating the efficacy of improved progesterone signaling as potential therapeutics for PE.

Low Dose of IL-2 Normalizes Hypertension and Mitochondrial Function in the RUPP Rat Model of Placental Ischemia

IL-2 is a cytokine released from CD4+T cells with dual actions and can either potentiate the inflammatory response or quell a chronic inflammatory response depending on its circulating concentration. IL-2 is elevated in many chronic inflammatory conditions and is increased during preeclampsia (PE). PE is characterized by new-onset hypertension during pregnancy and organ dysfunction and increasing evidence indicates that proinflammatory cytokines cause hypertension and mitochondrial (mt) dysfunction during pregnancy. The reduced uterine perfusion pressure (RUPP) model of placental ischemia is a rat model of PE that we commonly use in our laboratory and we have previously shown that low doses of recombinant IL-2 can decrease blood pressure in RUPP rats. The objective of this study was to determine the effects of a low dose of recombinant IL-2 on multi-organ mt dysfunction in the RUPP rat model of PE. We tested our hypothesis by infusing recombinant IL-2 (0.05 ng/mL) into RUPP rats on GD14 and examined mean arterial pressure (MAP), renal, placental and endothelial cell mt function compared to control RUPP. MAP was elevated in RUPP rats (n = 6) compared to controls (n = 5) (122 ± 5 vs. 102 ± 3 mmHg, p < 0.05), but was reduced by administration of LD recombinant IL-2 (107 ± 1 vs. 122 ± 5 mmHg, n = 9, p < 0.05). Renal, placental and endothelial mt ROS were significantly increased in RUPP rats compared to RUPP+ IL-2 and controls. Placental and renal respiration rates were reduced in RUPP rats compared to control rats but were normalized with IL-2 administration to RUPPs. These data indicate that low-dose IL-2 normalized multi-organ mt function and hypertension in response to placental ischemia.

Deficiency in CD4 T Cells Leads to Enhanced Postpartum Internal Carotid Artery Vasoconstriction in Mice: The Role of Nitric Oxide

The risk of postpartum (PP) stroke is increased in complicated pregnancies. Deficiency in CD4 T cell subsets is associated with preeclampsia and may contribute to PP vascular disease, including internal carotid artery (ICA) stenosis and stroke. We hypothesized that CD4 T cell deficiency in pregnancy would result in ICA dysregulation, including enhanced ICA vasoconstriction. We characterized the function, mechanical behavior, and structure of ICAs from C57BL/6 (WT) and CD4 deficient (CD4KO) mice, and assessed the role of NO in the control of ICA function at pre-conception and PP. WT and CD4KO mice were housed under pathogen-free conditions, mated to same-strain males, and allowed to litter or left virgin. At 3 days or 4 weeks PP, mice were euthanized. The responses to phenylephrine (PE), high K⁺ and acetylcholine (ACh) were assessed in pressurized ICAs before and after NOS inhibition. Passive lumen diameters were measured at 3–140 mmHg. eNOS and iNOS expression as well as the presence of T cells were evaluated by immunohistochemistry. Constriction of WT ICAs to PE was not modified PP. In contrast, responses to PE were significantly increased in ICAs from PP as compared to virgin CD4KO mice. Constriction to high K⁺ was not enhanced PP. ICAs from WT and CD4KO mice were equally sensitive to ACh with a significant rightward shift of dose-response curves after L-NNA treatment. NOS inhibition enhanced PE constriction of ICAs from WT virgin and PP mice. Although a similar effect was detected in ICAs of virgin CD4KO mice, no such changes were observed in vessels from PP CD4KO mice. Passive arterial distensibility at physiological levels of pressure was not modified at PP. ICA diameters were significantly increased in PP with no change in vascular wall thickness. Comparison of eNOS expression in virgin, 3 days and 4 weeks PP revealed a reduced expression in ICA from CD4 KO vs. WT PP vessels which reached significance at 4 weeks PP. iNos expression was similar and decreased over the PP period in vessels from WT and CD4KO mice. Dysregulation of the CD4 T cell population in pregnancy may make ICA vulnerable to vasospasm due to decreased NO-dependent control of ICA constriction. This may lead to cerebral hypoperfusion and increase the risk of maternal PP stroke.

Dietary protein source contributes to the risk of developing maternal syndrome in the Dahl salt-sensitive rat

Preeclampsia (PE) is a disorder of pregnancy, which is categorized by hypertension and proteinuria or signs of end-organ damage. Though PE is the leading cause of maternal and fetal morbidity and mortality, the mechanisms leading to PE remain unclear. The present study examined the contribution of dietary protein source (casein versus wheat gluten) to the risk of developing maternal syndrome utilizing two colonies of Dahl salt-sensitive (SS/JrHsdMcwi) rats. While the only difference between the colonies is the diet, the colonies exhibit profound differences in the pregnancy phenotypes. The SS rats maintained on the wheat gluten (SSWG) chow are protected from developing maternal syndrome; however, approximately half of the SS rats fed a casein-based diet (SSC) exhibit maternal syndrome. Those SSC rats that develop pregnancy-specific increases in blood pressure and proteinuria have no observable differences in renal or placental immune profiles compared to the protected SS rats. A gene profile array of placental tissue revealed a downregulation in Nos3 and Cyp26a1 in the SSC rats that develop maternal syndrome accompanied with increases in uterine artery resistance index suggesting the source of this phenotype could be linked to inadequate remodeling within the placenta. Investigations into the effects of multiple pregnancies on maternal health replicated similar findings. The SSC colony displayed an exacerbation in proteinuria, renal hypertrophy and renal immune cell infiltration associated with an increased mortality rate while the SSWG colony were protected highlighting how dietary protein source could have beneficial effects in PE.