Elevated S100A9 in preeclampsia induces soluble endoglin and IL-1β secretion and hypertension via the NLRP3 inflammasome

Understanding a Potential Role for the NLRP3 Inflammasome in Placenta-Mediated Pregnancy Complications

Stillbirth affects approximately 2 million pregnancies annually and is closely linked to placental dysfunction, which may also present clinically as foetal growth restriction (FGR) or pre-eclampsia (PE). Placental dysfunction can arise from a range of insults, including the inflammatory conditions villitis of unknown aetiology (VUE) and chronic histiocytic intervillositis (CHI). Despite ample research regarding the pathophysiology of placental dysfunction, the literature surrounding placental inflammation is more limited, with no currently established treatments. In the absence of infection, placental inflammation is hypothesised to be stimulated by damage-associated molecular patterns (DAMPs), known as sterile inflammation. The NLRP3 inflammasome, a protein scaffold that unites within the cytosol of cells, is a proposed contributor. The NLRP3 inflammasome is dysregulated in numerous diseases and has shown evidence of activation through the sterile inflammatory pathway via DAMPs. Studies have demonstrated the upregulation of the NLRP3 inflammasome and its components in placentally-mediated pregnancy pathologies. However, the link between placental dysfunction seen in these disorders and the NLRP3 inflammasome is not yet firmly established. This manuscript aims to review the evidence regarding placental inflammation seen with placental dysfunction, discuss its association with the NLRP3 inflammasome, and identify potential therapeutic interventions for this pathological inflammatory response.

Clinical significance of NLRP3 inflammasome and related cell molecules in early diabetic kidney disease in elderly population

Background

The paper aims to investigate the expression level of NLRP3 inflammasome and its related cell molecules in early diabetes kidney disease (EDKD) in the elderly and its clinical application value.

Methods

From October 2021 to April 2023, 50 elderly patients with T2DM (T2DM group), 50 elderly patients with EDKD (EDKD group) and 50 elderly people who passed the health check-up (healthy group) were chosen as the study subjects. Plasma NLRP3 inflammasome and related cells (blood leukocyte count, monocyte count, lymphocyte count) molecular (NT-proBNP and others) levels are tested, and Pearson correlation analysis is utilized to explore the correlation among plasma NLRP3 inflammasome and related cells, molecules, and renal function indicators (UACR, BUN, Ucr) in elderly patients with EDKD.

Results

(1) The three groups' comparison in HbA1c, FIns, HOMA-IR, UACR, BUN, Ucr, SOD, MCP-1, and TNF-a levels were with P<0.05. The levels of TG and LDL-C in the EDKD group were higher than those in the T2DM and the healthy groups; the levels of FPG, HbA1c, FINs, HOMA-IR, UACR, SOD, MCP-1, TNF-a in the EDKD and T2DM groups were higher than those in the healthy group, while SOD was smaller than that in the healthy group; the levels of BUN, Ucr, hs-CRP, FPG, HbA1c, FINs, HOMA-IR, UACR, SOD, MCP-1, TNF-a in the EDKD group were higher than those in the T2DM group, while SOD was smaller than that in the T2DM group. The above results were with P<0.05. (2) It has P<0.05 in Monocyte count, NLRP3, NT-proBNP, caspase-1, ASC and others in the three groups. Those in the EDKD and T2DM groups were higher than those in the healthy group. The levels of these indicators in the EDKD group were higher than those in the T2DM group, with P<0.05. NLRP3, Caspase-1, ASC, IL1b, and IL-18 were positively correlated with UACR, BUN, and Ucr in the EDKD group. All the above differences were P<0.05.

Conclusions

NLRP3 inflammasome and its related molecules caspase-1, ASC, IL-1b, IL-18 and other levels increase in early elderly EDKD and are closely related to the severity of EDKD.

Blocking GATA6 Alleviates Pyroptosis and Inhibits Abdominal Wall Endometriosis Lesion Growth Through Inactivating the PI3K/AKT Pathway

Endometriosis is a benign gynecological disorder characterized by the abnormal presence of endometrium-like cells, referred to as ectopic tissue, located outside the uterine cavity. Beyond the abnormal proliferation of endometrium-like tissues within and beyond the pelvic cavity, compelling scientific evidence underscores the crucial involvement of the NOD-like receptor NLRP3 inflammasome and pyroptosis in the pathogenesis of EMS. Our investigation has revealed a striking upregulation of the endogenous protein GATA-binding protein 6 (GATA6) in abdominal wall EMS. Notably, the knockdown of GATA6 significantly impaired the viability and migratory potential of primary ectopic endometrial stromal cells (EESCs) while also inhibiting crucial markers of pyroptosis, such as NLRP3, the gasdermin D N-terminal fragment (GSDMD-N), and reactive oxygen species (ROS) levels within these cells. Delving deeper into the underlying mechanisms, we discovered that suppressing GATA6 mitigated the activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway in EESCs. The administration of 740 Y-P, an agonist of the PI3K/AKT pathway, mitigated the inhibitive actions of GATA6 knockdown on EESCs' growth, migration, and pyroptosis, highlighting the intricate crosstalk between GATA6 and this intricate signaling cascade. In vivo experiments corroborated these findings, demonstrating that reduced GATA6 expression effectively restrained the growth of endometrial lesions and concurrently suppressed pyroptosis, accompanied by a dampening of PI3K/AKT signaling within these lesions. In summary, our study underscores the pivotal role of GATA6 in modulating the growth and pyroptosis of abdominal wall EMS through its regulation of the PI3K/AKT signaling pathway. Silencing GATA6 emerges as a promising approach to alleviate pyroptosis and potentially offers a novel therapeutic angle for managing abdominal wall EMS.

Advances in the study of S100A9 in cardiovascular diseases

Cardiovascular disease (CVD) is a group of diseases that primarily affect the heart or blood vessels, with high disability and mortality rates, posing a serious threat to human health. The causative factors, pathogenesis, and characteristics of common CVD differ, but they all involve common pathological processes such as inflammation, oxidative stress, and fibrosis. S100A9 belongs to the S100 family of calcium-binding proteins, which are mainly secreted by myeloid cells and bind to the Toll-like receptor 4 and receptor for advanced glycation end products and is involved in regulating pathological processes such as inflammatory response, fibrosis, vascular calcification, and endothelial barrier function in CVD. The latest research has found that S100A9 is a key biomarker for diagnosing and predicting various CVD. Therefore, this article reviews the latest research progress on the diagnostic and predictive, and therapeutic value of S100A9 in inflammatory-related CVD such as atherosclerosis, myocardial infarction, and arterial aneurysm and summarizes its molecular mechanisms in the progression of CVD, aiming to explore new predictive methods and to identify potential intervention targets for CVD in clinical practice.

Differential proteomics of circulating extracellular vesicles of placental origin isolated from women with early-onset preeclampsia reveal aberrant innate immune and hemostasis processes

PROBLEM

Early-onset preeclampsia (EOPE) is a severe gestational hypertensive disorder with significant feto-maternal morbidity and mortality due to uteroplacental insufficiency. Circulating extracellular vesicles of placental origin (EV-P) are known to be involved in the pathophysiology of EOPE and might serve as an ideal reservoir for its specific biomarkers. Therefore, we aimed to characterize and perform comparative proteomics of circulating EV-P from healthy pregnant and EOPE women before delivery.

METHOD OF STUDY

The EV-P from both groups were isolated using immunoaffinity and were characterized using transmission electron microscopy, dynamic light scattering, nanoparticle tracking analysis, and immunoblotting. Following IgG albumin depletion, the pooled proteins that were isolated from EV-P of both groups were subjected to quantitative TMT proteomics.

RESULTS

Circulating term EV-P isolated from both groups revealed ∼150 nm spherical vesicles containing CD9 and CD63 along with placental PLAP and HLA-G proteins. Additionally, the concentration of EOPE-derived EV-P was significantly increased. A total of 208 proteins were identified, with 26 among them being differentially abundant in EV-P of EOPE women. This study linked the pathophysiology of EOPE to 19 known and seven novel proteins associated with innate immune responses such as complement and TLR signaling along with hemostasis and oxygen homeostasis.

CONCLUSION

The theory suggesting circulating EVs of placental origin could mimic molecular information from the parent organ-"the placenta"-is strengthened by this study. The findings pave the way for possible discovery of novel prognostic and predictive biomarkers as well as provide insight into the mechanisms driving the pathogenesis of EOPE.

Comparison of immune-related gene signatures and immune infiltration features in early- and late-onset preeclampsia

BACKGROUND

Preeclampsia, a severe pregnancy syndrome, is widely accepted divided into early- and late-onset preeclampsia (EOPE and LOPE) based on the onset time of preeclampsia, with distinct pathophysiological origins. However, the molecular mechanism especially immune-related mechanisms for EOPE and LOPE is currently obscure. In the present study, we focused on placental immune alterations between EOPE and LOPE and search for immune-related biomarkers that could potentially serve as potential therapeutic targets through bioinformatic analysis.

METHODS

The gene expression profiling data was obtained from the Gene Expression Omnibus database. ESTIMATE algorithm and Gene Set Enrichment Analysis were employed to evaluate the immune status. The intersection of differentially expressed genes in GSE74341 series and immune-related genes set screened differentially expressed immune-related genes. Protein-protein interaction network and random forest were used to identify hub genes with a validation by a quantitative real-time PCR. Kyoto Encyclopedia of Genes and Genomes pathways, Gene Ontology and gene set variation analysis were utilized to conduct biological function and pathway enrichment analyses. Single-sample gene set enrichment analysis and CIBERSORTx tools were employed to calculate the immune cell infiltration score. Correlation analyses were evaluated by Pearson correlation analysis. Hub genes-miRNA network was performed by the NetworkAnalyst online tool.

RESULTS

Immune score and stromal score were all lower in EOPE samples. The immune system-related gene set was significantly downregulated in EOPE compared to LOPE samples. Four hub differentially expressed immune-related genes (IL15, GZMB, IL1B and CXCL12) were identified based on a protein-protein interaction network and random forest. Quantitative real-time polymerase chain reaction validated the lower expression levels of four hub genes in EOPE compared to LOPE samples. Immune cell infiltration analysis found that innate and adaptive immune cells were apparent lacking in EOPE samples compared to LOPE samples. Cytokine-cytokine receptor, para-inflammation, major histocompatibility complex class I and T cell co-stimulation pathways were significantly deficient and highly correlated with hub genes. We constructed a hub genes-miRNA regulatory network, revealing the correlation between hub genes and hsa-miR-374a-5p, hsa-miR-203a-3p, hsa-miR-128-3p, hsa-miR-155-3p, hsa-miR-129-2-3p and hsa-miR-7-5p.

CONCLUSIONS

The innate and adaptive immune systems were severely impaired in placentas of EOPE. Four immune-related genes (IL15, GZMB, IL1B and CXCL12) were closely correlated with immune-related pathogenesis of EOPE. The result of our study may provide a new basis for discriminating between EOPE and LOPE and acknowledging the role of the immune landscape in the eventual interference and tailored treatment of EOPE.

Noninvasive preeclampsia prediction using plasma cell-free RNA signatures

BACKGROUND

Preeclampsia, especially preterm preeclampsia and early-onset preeclampsia, is a life-threating pregnancy disorder, and the heterogeneity and complexity of preeclampsia make it difficult to predict risk and to develop treatments. Plasma cell-free RNA carries unique information from human tissue and may be useful for noninvasive monitoring of maternal, placental, and fetal dynamics during pregnancy.

OBJECTIVE

This study aimed to investigate various RNA biotypes associated with preeclampsia in plasma and to develop classifiers to predict preterm preeclampsia and early-onset preeclampsia before diagnosis.

STUDY DESIGN

We performed a novel, cell-free RNA sequencing method termed polyadenylation ligation-mediated sequencing to investigate the cell-free RNA characteristics of 715 healthy pregnancies and 202 pregnancies affected by preeclampsia before symptom onset. We explored differences in the abundance of different RNA biotypes in plasma between healthy and preeclampsia samples and built preterm preeclampsia and early-onset preeclampsia prediction classifiers using machine learning methods. Furthermore, we validated the performance of the classifiers using the external and internal validation cohorts and assessed the area under the curve and positive predictive value.

RESULTS

We detected 77 genes, including messenger RNA (44%) and microRNA (26%), that were differentially expressed in healthy mothers and mothers with preterm preeclampsia before symptom onset, which could separate participants with preterm preeclampsia from healthy samples and that played critical functional roles in preeclampsia physiology. We developed 2 classifiers for predicting preterm preeclampsia and early-onset preeclampsia before diagnosis based on 13 cell-free RNA signatures and 2 clinical features (in vitro fertilization and mean arterial pressure), respectively. Notably, both classifiers showed enhanced performance when compared with the existing methods. The preterm preeclampsia prediction model achieved 81% area under the curve and 68% positive predictive value in an independent validation cohort (preterm, n=46; control, n=151); the early-onset preeclampsia prediction model had an area under the curve of 88% and a positive predictive value of 73% in an external validation cohort (early-onset preeclampsia, n=28; control, n=234). Furthermore, we demonstrated that downregulation of microRNAs may play vital roles in preeclampsia through the upregulation of preeclampsia-relevant target genes.

CONCLUSION

In this cohort study, a comprehensive transcriptomic landscape of different RNA biotypes in preeclampsia was presented and 2 advanced classifiers with substantial clinical importance for preterm preeclampsia and early-onset preeclampsia prediction before symptom onset were developed. We demonstrated that messenger RNA, microRNA, and long noncoding RNA can simultaneously serve as potential biomarkers of preeclampsia, holding the promise of prevention of preeclampsia in the future. Abnormal cell-free messenger RNA, microRNA, and long noncoding RNA molecular changes may help to elucidate the pathogenic determinants of preeclampsia and open new therapeutic windows to effectively reduce pregnancy complications and fetal morbidity.

NLRP3 inflammasome in peripheral blood monocytes as a risk factor for early -onset preeclampsia

INTRODUCTION

As a leading cause of pregnancy and fetal mortality, pre-eclampsia impacts about 5-8% of pregnancies globally. To date, few studies have focused on the role played by (NOD)-like receptors protein 3 (NLRP3) in peripheral blood in early-onset pre-eclampsia (PE). In this study, we investigated whether NLRP3 expression in monocytes before 20 weeks of gestation was associated with an increased risk of early-onset PE.

METHODOLOGY

During the study period from 2019 to 2021, women with singleton pregnancies were enrolled in this prospective study at the General Hospital of Northern Theater Command. A generalized additive model (GAM) and logistic regression models were applied to determine any association between NLRP3 and the risk of early-onset PE.

RESULTS

In total, 571 and 48 subjects were included in the control and pre-eclampsia groups, respectively. The GAM and logistic regression models showed that NLRP3 was a significant factor for PE occurrence. The area under the curve, accuracy, specificity, sensitivity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.86, 0.82, 0.95, 0.72, 15.17, 0.29, and 52.0, respectively.

CONCLUSION

The monitoring for NLRP3 in peripheral blood may be a potential, prospectively identifying risk factor for preeclampsia.

Integrated microRNA and secretome analysis of human endometrial organoids reveal the miR-3194-5p/Aquaporin/S100A9 module in regulating trophoblast functions

Successful placentation requires delicate communication between the endometrium and trophoblasts. The invasion and integration of trophoblasts into the endometrium during early pregnancy is crucial to placentation. Dysregulation of these functions is associated with various pregnancy complications, such as miscarriage and preeclampsia. The endometrial microenvironment has an important influence on trophoblast cell functions. The precise effect of the endometrial gland secretome on trophoblast functions remains uncertain. We hypothesized that the hormonal environment regulates the miRNA profile and secretome of the human endometrial gland, which subsequently modulates trophoblast functions during early pregnancy. Human endometrial tissues were obtained from endometrial biopsies with written consent. Endometrial organoids were established in matrix gel under defined culture conditions. They were treated with hormones mimicking the environment of the proliferative phase (Estrogen, E2), secretory phase (E2+Progesterone, P4), and early pregnancy (E2+P4+Human Chorionic Gonadotropin, hCG). miRNA-seq was performed on the treated organoids. Organoid secretions were also collected for mass spectrometric analysis. The viability and invasion/migration of the trophoblasts after treatment with the organoid secretome were determined by cytotoxicity assay and transwell assay, respectively. Endometrial organoids with the ability to respond to sex steroid hormones were successfully developed from human endometrial glands. By establishing the first secretome profiles and miRNA atlas of these endometrial organoids to the hormonal changes followed by trophoblast functional assays, we demonstrated that sex steroid hormones modulate aquaporin (AQP)1/9 and S100A9 secretions through miR-3194 activation in endometrial epithelial cells, which in turn enhanced trophoblast migration and invasion during early pregnancy. By using a human endometrial organoid model, we demonstrated for the first time that the hormonal regulation of the endometrial gland secretome is crucial to regulating the functions of human trophoblasts during early pregnancy. The study provides the basis for understanding the regulation of early placental development in humans.

Preeclampsia and COVID-19: the Role of Inflammasome Activation

PURPOSE OF REVIEW

It is well established that controlled immune activation and balance is critical for women's reproductive health and successful pregnancy outcomes. Research in recent decades in both clinical and animal studies has demonstrated that aberrant immune activation and inflammation play a role in the development and progression of women's reproductive health and pregnancy-related disorders. Inflammasomes are multi-protein cytoplasmic complexes that mediate immune activation. In this review, we summarize current knowledge on the role of inflammasome activation in pregnancy-related disorders.

RECENT FINDINGS

Increased activation of inflammasome is associated with multiple women's health reproductive disorders and pregnancy-associated disorders, including preeclampsia (PreE). Inflammasome activation is also associated with the novel coronavirus disease 2019 (COVID-19) disease caused by the SARS-Cov-2 virus. We and others have observed a positive association between increased PreE incidences with the onset of the COVID-19 pandemic. Here, we present our recent data indicating increased inflammasome activation, represented by caspase-1 activity, in women with COVID-19 and PreE compared to normotensive pregnant women COVID-19. The role of inflammation in pregnancy-related disorders is an area of intense research interest. With the onset of the COVID-19 pandemic and the associated increase in PreE observed clinically, there is a greater need to identify mechanisms of pathophysiology and targets to treat this maternal disorder. Inflammasome activation is associated with PreE and COVID-19 infection and may hold therapeutic potential to improve outcomes associated with PreE and curb the morbidity attributed to PreE.