IL11 activates the placental inflammasome to drive preeclampsia

Causal relationships between immune cells, inflammatory factors, and preeclampsia: A two-step, two-sample mendelian randomization study

BACKGROUND

Preeclampsia (PE) is a complex hypertensive disorder that occurs during pregnancy, with the immune system playing a key role. Although immune modulation is implicated in PE progression, the roles of specific immune cells and inflammatory mediators remain unclear.

METHODS

We conducted a two-sample, two-step Mendelian randomization (MR) analysis, primarily using the inverse-variance weighted method, to investigate the causal effect of immune cell traits on PE. Additionally, we assessed the potential mediation effects of inflammatory factors.

RESULTS

The MR analyses revealed that 22 immune cell traits exert protective effects against PE, whereas 19 are associated with an increased risk. Additionally, four inflammatory factors were suggested to be linked to PE. Mediation analysis identified the absolute count (AC) of CD33 + HLA DR+ cells, including the CD14 - subset, as causally related to PE. Both the total effect of the CD33 + HLA DR+ AC (odds ratio [OR] = 0.977, 95 % confidence interval [CI], 0.960-0.994; P = 0.010) and the effect of CD33 + HLA DR+ CD14 - cells (OR = 0.977, 95 % CI, 0.963-0.991; P = 0.001) were significant. These effects were partially mediated by STAM-binding protein levels, contributing 16.7 % and 15.0 % to the total effects of the CD33 + HLA DR+ AC and CD33 + HLA DR+ CD14 - AC, respectively.

CONCLUSION

This study establishes a causal relationship between specific immune cells and PE, potentially mediated by inflammatory factors, highlighting the importance of these traits in PE pathogenesis. Further research is needed to validate these findings based on larger, more diverse cohorts.

Early prediction of preeclampsia using the first trimester vaginal microbiome

Preeclampsia is a severe obstetrical syndrome which contributes to 10-15% of all maternal deaths. Although the mechanisms underlying systemic damage in preeclampsia-such as impaired placentation, endothelial dysfunction, and immune dysregulation-are well studied, the initial triggers of the condition remain largely unknown. Furthermore, although the pathogenesis of preeclampsia begins early in pregnancy, there are no early diagnostics for this life-threatening syndrome, which is typically diagnosed much later, after systemic damage has already manifested. Here, we performed deep metagenomic sequencing and multiplex immunoassays of vaginal samples collected during the first trimester from 124 pregnant individuals, including 62 who developed preeclampsia with severe features. We identified multiple significant associations between vaginal immune factors, microbes, clinical factors, and the early pathogenesis of preeclampsia. These associations vary with BMI, and stratification revealed strong associations between preeclampsia and Bifidobacterium spp., Prevotella timonensis, and Sneathia vaginalis. Finally, we developed machine learning models that predict the development of preeclampsia using this first trimester data, collected ~5.7 months prior to clinical diagnosis, with an auROC of 0.78. We validated our models using data from an independent cohort (MOMS-PI), achieving an auROC of 0.80. Our findings highlight robust associations among the vaginal microbiome, local host immunity, and early pathogenic processes of preeclampsia, paving the way for early detection, prevention and intervention for this devastating condition.

The role of pyroptosis in the occurrence and development of pregnancy-related diseases

Pyroptosis is a form of programmed cell death that is crucial in the development of various diseases, including autoimmune diseases, atherosclerotic diseases, cancer, and pregnancy complications. In recent years, it has gained significant attention in national and international research due to its association with inflammatory immune overactivation and its involvement in pregnancy complications such as miscarriage and preeclampsia (PE). The mechanisms discussed include the canonical pyroptosis pathway of gasdermin activation and pore formation (caspase-1-dependent pyroptosis) and the non-canonical pyroptosis pathway (cysteoaspartic enzymes other than caspase-1). These pathways work on various cellular and factorial levels to influence normal pregnancy. This review aims to summarize and analyze the pyroptosis pathways associated with abnormal pregnancies and pregnancy complications. The objective is to enhance pregnancy outcomes by identifying various targets to prevent the onset of pyroptosis.

Exploratory study on the mechanism of necrotic effect of nourishing cells in the context of genital tract infection in premature rupture of membranes

To explore the mechanism of necrotic effect of nourishing cells in the context of genital tract infection in premature rupture of membranes (PROM). One hundred eight patients with PROM treated at our hospital from June 2020 to June 2022 were selected as the PROM group. Simultaneously, 108 cases of normal full-term pregnant women were chosen as the control group. Western blot analysis was performed to measure the relative expression levels of cysteinyl aspartate specific proteinase-1 (Caspase-1), cysteinyl aspartate specific proteinase-3 (Caspase-3), nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3), and interleukin (IL)-1β proteins, which are associated with necrosis of placental nourishing cells, in the placenta of both groups. TUNEL staining was used to detect the number of apoptotic placental nourishing cells. The differences in necrotic factors of placental nourishing cells were analyzed between full-term and preterm cases in the PROM group, as well as among patients with different genital tract infections. The apoptotic count of placental nourishing cells in the PROM group was 58.46 ± 11.26 cells/field, which was markedly higher than that of the control group (P < .05). The relative expression levels of the necrotic factors Caspase-1, Caspase-3, NLRP3, and IL-1β proteins in placental nourishing cells of the PROM group were 1.32 ± 0.26, 1.19 ± 0.30, 1.29 ± 0.28, and 1.23 ± 0.24, respectively. These values were significantly higher than those of the control group (P < .05). The relative expression levels of the necrotic factors Caspase-1, Caspase-3, NLRP3, and IL-1β proteins in placental nourishing cells were compared between full-term and preterm patients in the PROM group (P > .05). The relative expression levels of the necrotic factors Caspase-1, Caspase-3, NLRP3, and IL-1β proteins in placental nourishing cells were higher in patients with multiple genital tract infections compared to those with single infections or no infections in the PROM group (P < .05). PROM is associated with a significant upregulation of placental nourishing cell apoptosis and necrotic factors, including Caspase-1, Caspase-3, NLRP3, and IL-1β proteins. This upregulation is correlated with the presence of genital tract infections.

Understanding interleukin 11 as a disease gene and therapeutic target

Interleukin 11 (IL11) is an elusive member of the IL6 family of cytokines. While initially thought to be a haematopoietic and cytoprotective factor, more recent data show instead that IL11 is redundant for haematopoiesis and toxic. In this review, the reasons that led to the original misunderstandings of IL11 biology, which are now understandable, are explained with particular attention on the use of recombinant human IL11 in mice and humans. Following tissue injury, as part of an evolutionary ancient homeostatic response, IL11 is secreted from damaged mammalian cells to signal via JAK/STAT3, ERK/P90RSK, LKB1/mTOR and GSK3β/SNAI1 in autocrine and paracrine. This activates a program of mesenchymal transition of epithelial, stromal, and endothelial cells to cause inflammation, fibrosis, and stalled endogenous tissue repair, leading to organ failure. The role of IL11 signalling in cell- and organ-specific pathobiology is described, the large unknowns about IL11 biology are discussed and the promise of targeting IL11 signalling as a therapeutic approach is reviewed.