NETs promote ROS production to induce human amniotic epithelial cell apoptosis via ERK1/2 signaling in spontaneous preterm birth

The clinic application of mNGS and ENA-78 assays to identify intra-amniotic infection/inflammation

Objective

The objective of this study is to explore whether metagenomic next-generation sequencing (mNGS) and Epithelial Neutrophil Activating Peptide-78 (ENA-78) assays in the amniotic fluid (AF) of patients with preterm labor (PTL) could be employed for diagnosing intra-amniotic infection/inflammation (IAI/I) and predict the outcomes of emergency cerclage in women with cervical insufficiency(CI).

Methods

AF samples from 40 patients were subjected to PTL were subjected to mNGS and microbial culture to diagnose intra-amniotic infection known as microbial invasion of the amniotic cavity (MIAC); ELISA was used to analyze ENA-78 levels for prediction of intra-amniotic inflammation (IAI). Pregnancy outcomes were compared, the predictive performance of mNGS and ENA-78 were assessed to evaluate the efficacy of emergency cervical cerclage.

Results

The diagnosis rate of MIAC was higher with mNGS (17.5%) compared to microbial culture (2.5%). AF ENA-78 levels were significantly higher in IAI patients than in non-IAI/I patients. ENA-78 demonstrated certain accuracy in identifying IAI, with sensitivity and specificity of 73.3% and 100%, respectively. Compared with non-IAI/I patients, patients with MIAC or IAI exhibited poor pregnancy outcomes after cervical cerclage.

Conclusions

mNGS and ENA-78 assays are valuable means for assessing the state of infection/inflammation in the amniotic cavity and predicting the outcomes of emergency cerclage.

Kuiyangling Enema Alleviates Ulcerative Colitis Mice by Reducing Levels of Intestinal NETs and Promoting HuR/VDR Signaling

Purpose

Kuiyangling is a traditional Chinese medicine formula used for the treatment of ulcerative colitis, but the specific mechanism remains unclear. Imbalance in NETs regulation is one of the important factors contributing to the onset of ulcerative colitis (UC). The HuR/VDR signaling pathway plays a significant role in restoring the intestinal mucosal barrier in UC. The aim of this study is to explore the mechanism of Kuiyangling in the treatment of ulcerative colitis.

Methods

A mouse model of ulcerative colitis using 3% DSS water was considered, and model, normal, Kuiyangling medium- (5 g·kg-1) and high-dose (10 g·kg-1), and mesalazine (50 mg·kg-1) groups were created. Measurements of colon length, spleen index, histopathological variances, subcellular structure observations, ROS content, and NET-related proteins (PAD4, MPO, citH3) were obtained through HE staining, electron microscopy, live imaging, and Western blotting assays. Immunohistochemistry and immunofluorescence analyses were conducted to assess the levels of HuR/VDR protein complex, ZO-1, Occludin, Claudin-7, and intestinal NETs. An ELISA kit was utilized to determine cytokine levels, LC-MS was performed to analyze the composition of Kuiyangling, and next-generation sequencing was conducted for detection of the intestinal mucosal transcriptome.

Results

Kuiyangling reduced DAI, splenic index, and ROS content; maintained mucosal structure; decreased inflammation; and increased colon length and body mass index. Western blotting indicated that Kuiyangling reduced PAD4,MPO, and citH3 levels. Kuiyangling decreased NETs and increased the expression levels of ZO-1, Occludin, and Claudin-7, as well as up-regulating HuR, VDR, and HuR/VDR proteins. Kuiyangling reduced IL-1β, IL-6, and TNF-α levels while increasing TGF-β, IL-10, and IL-37 levels. Kuiyangling reduced inflammatory response proteins and elevated the levels of anti-inflammatory and intestinal barrier proteins, possibly inhibiting the TNF and oxidative phosphorylation signaling pathways.

Conclusion

Kuiyangling enema in treating ulcerative colitis in mice, associated with a reduction in intestinal NETs and enhancement of HuR-mediated intestinal barrier signaling pathways.

Molecular profiling unveils pyroptosis markers in preterm birth

Through a comprehensive examination of pyroptosis-related differential expressed genes (PRDEGs), this work investigates the molecular complexities of spontaneous preterm birth (SPTB), also known as premature delivery, before the due date. Through the process of merging and correcting batch effects in the GSE120480 and GSE73714 datasets, we were able to identify 36 PRDEGs that exhibited significant expression differentiation in SPTB. Through functional enrichment and pathway analysis, their importance in amino acid transport and cytokine receptor interaction has been highlighted. Among the genes that have emerged as crucial, CEBPA, APOA1, and CEP55 have been identified. The relevance of these molecules was demonstrated using experimental knockdowns, which also suggested that they could be used as molecular biomarkers and therapeutic targets for SPTB.

Metabolic dysregulation-triggered neutrophil extracellular traps exacerbate acute liver failure

Acute liver failure (ALF) is an acute liver disease with a high mortality rate in clinical practice, characterized histologically by extensive hepatocellular necrosis and massive neutrophil infiltration. However, the role of these abnormally infiltrating neutrophils during ALF development is unclear. Here, in an ALF mouse model, metabolites were identified that promote the formation of neutrophil extracellular traps (NETs) in the liver, subsequently influencing macrophage differentiation and disease progression. ALF occurs with abnormalities in hepatic and intestinal metabolites. Abnormal metabolites (LTD4 and glutathione) can directly, or indirectly via reactive oxygen species, promote NET formation of infiltrating neutrophils, which subsequently regulate macrophages in a pro-inflammatory M1-like state, inducing an amplification of the destructive effects of inflammation. Together, this study provides new insights into the role of NETs in the pathogenesis of ALF.

Impaired neutrophil extracellular trap-forming capacity contributes to susceptibility to chronic vaginitis in a mouse model of vulvovaginal candidiasis

Vulvovaginal candidiasis (VVC), caused by Candida albicans, is characterized by aberrant inflammation by polymorphonuclear neutrophils (PMNs) in the vaginal lumen. Data from the established murine model shows that despite potent antifungal properties, PMNs fail to clear C. albicans due to local heparan sulfate that inhibits the interaction between PMNs and C. albicans, resulting in chronic vaginal immunopathology. To understand the role of neutrophil extracellular traps (NETs) in defense against C. albicans at the vaginal mucosa, we investigated the NET-forming capacity of PMNs in chronic VVC-susceptible (CVVC-S/C3H) and -resistant (CVVC-R/CD-1) mouse strains. Immunofluorescence revealed the formation of NETs (release of DNA with PMN-derived antimicrobial proteins) in PMN-C. albicans cocultures using vaginal conditioned medium (VCM) generated from CVVC-R/CD-1 mice, similar to NET-inducing positive controls. Under these NETotic conditions, PMNs released high levels of double-stranded DNA bound with NET-associated proteins, concomitant with substantial C. albicans killing activity. In contrast, PMN-C. albicans cocultures in VCM from CVVC-S/C3H mice lacked NET formation together with reduced antifungal activity. Similar results were observed in vivo: active NET-C. albicans interaction followed by fungal clearance in inoculated CVVC-R/CD-1 mice, and sustained high vaginal fungal burden and no evidence of NETs in inoculated CVVC-S/C3H mice. Furthermore, the level of Ki67 expression, a putative NETotic PMN marker, was significantly reduced in vaginal lavage fluid from CVVC-S/C3H mice compared to CVVC-R/CD-1 mice. Finally, scanning electron microscopy revealed that PMNs in CVVC-R, but not CVVC-S, conditions exhibited NETs in direct contact with C. albicans hyphae in vitro and in vivo. These results suggest that VVC-associated immunopathology includes impaired NET-mediated antifungal activity.