The Underlying Molecular Basis and Mechanisms of Venous Thrombosis in Patients with Osteomyelitis: A Data-Driven Analysis

PTGS2 Silencing Inhibits Ferroptosis in Staphylococcus Aureus-induced Osteomyelitis By Blocking the IL-17A Signaling Pathway

OBJECTIVE

Osteomyelitis caused by Staphylococcus aureus (S. aureus) infection is an inflammatory bone disease characterized by continuous bone destruction, which is difficult to treat. This research aimed to explore the molecular mechanisms of S. aureus-induced osteomyelitis.

METHODS

Using the GSE166522 and GSE227521 datasets, hub differentially expressed genes (DEGs) were screened by bioinformatics analysis. Hub gene expression levels were validated in S. aureus-induced mouse models. An inhibitor of PTGS2, etoricoxib, was used to assess the role of PTGS2 in the osteomyelitis mouse model. PTGS2 was silenced in an LPS-induced MC3T3-E1 cell model to study its effect on cell function.

RESULTS

Six hub genes were screened, including ARG1, TIMP1, NOS2, PTGS2, SOCS3, and IL1B, highly expressed in the S. aureus-induced osteomyelitis model. Etoricoxib treatment attenuated the inflammatory infiltration of tibial tissue in mice with osteomyelitis. In vivo and in vitro, etoricoxib treatment and PTGS2 silencing reduced inflammatory factor (TNF-α, IL-1β, and IL-6) levels. PTGS2 silencing promoted LPS-induced MC3T3-E1 cell viability and inhibited apoptosis and ferroptosis. GPX4 and SLC7A11 protein levels were significantly increased after PTGS2 silencing. Mechanistically, IL-17A intervention significantly counteracted the impact of PTGS2 silencing on cell behaviors and secukinumab combined with PTGS2 silencing more effectively suppressed inflammation and ferroptosis, indicating that PTGS2 impeded the osteomyelitis progression by inhibiting the IL-17A pathway.

CONCLUSION

Silencing PTGS2 reduces ferroptosis in S. aureus-induced osteomyelitis by obstructing the IL-17A pathway, which suggests a new approach for the treatment of osteomyelitis.

Exploration of the causal relationship and mechanisms between serum albumin and venous thrombosis: a bidirectional mendelian randomization analysis and bioinformatics study

BACKGROUND

To explore the causal relationship between serum albumin and venous thromboembolism (VTE) comprises deep vein thrombosis (DVT) and its consequential condition, pulmonary embolism (PE), through Mendelian randomization (MR) design, seeking to clarify the protective roles of albumin in the development of venous thrombosis.

METHODS

We performed a bidirectional two-sample Mendelian randomization analysis utilizing albumin genome-wide association study (GWAS) data alongside VTE datasets from various sources. Additionally, to minimize heterogeneity across different datasets, a meta-analysis of the Mendelian randomization results was conducted. Furthermore, genes associated with such exposures were identified to unravel how exposure impacts outcomes. This was followed by applying bioinformatics techniques for gene enrichment analysis and employing the Cytoscape software to pinpoint the hub genes.

RESULTS

The findings from the meta-analysis of the Mendelian randomization indicate that reduced levels of albumin are associated with an elevated risk of VTE (OR = 0.739, 95% CI: 0.695 to 0.787, P = 1.82e-9), DVT (OR = 0.700, 95% CI: 0.646 to 0.772, P = 2.96e-15), and PE (OR = 0.717, 95% CI: 0.647 to 0.793, P = 1.74e-10). Bioinformatics analysis revealed that serum albumin primarily protects against VTE by influencing inflammation and cytokines.

CONCLUSIONS

Our bidirectional MR analysis confirmed a substantial causal association linking serum albumin to VTE. Bioinformatics analysis revealed that this causal link is mediated by the immune response through inflammation and cytokines.

Gene Expression Dysregulation in Whole Blood of Patients with Clostridioides difficile Infection

Clostridioides difficile (C. difficile) is a global threat and has significant implications for individuals and health care systems. Little is known about host molecular mechanisms and transcriptional changes in peripheral immune cells. This is the first gene expression study in whole blood from patients with C. difficile infection. We took blood and stool samples from patients with toxigenic C. difficile infection (CDI), non-toxigenic C. difficile infection (GDH), inflammatory bowel disease (IBD), diarrhea from other causes (DC), and healthy controls (HC). We performed transcriptome-wide RNA profiling on peripheral blood to identify diarrhea common and CDI unique gene sets. Diarrhea groups upregulated innate immune responses with neutrophils at the epicenter. The common signature associated with diarrhea was non-specific and shared by various other inflammatory conditions. CDI had a unique 45 gene set reflecting the downregulation of humoral and T cell memory functions. Dysregulation of immunometabolic genes was also abundant and linked to immune cell fate during differentiation. Whole transcriptome analysis of white cells in blood from patients with toxigenic C. difficile infection showed that there is an impairment of adaptive immunity and immunometabolism.

miR-2467-3p/ABLIM1 Axis Mediates the Formation and Progression of Deep Vein Thrombosis by Regulating Inflammation and Oxidative Stress

Deep vein thrombosis (DVT) is a common postoperative complication of orthopaedic surgery with a complex pathogenesis mechanism. The effect of the miR-2467-3p/acting-binding LIM protein 1 (ABLIM1) axis on thrombus formation and human vascular endothelial cells (HUVECs) progression was evaluated aiming to identify a novel potential biomarker of DVT. DVT rat models were established by inferior vena cava stenosis. The expression of the miR-2467-3p/ABLIM1 axis was analyzed by PCR. HUVECs were induced with oxidative low-density lipoprotein (ox-LDL). Cell growth and motility were assessed by cell counting kit 8 (CCK8) and Transwell assay. The inflammation and oxidative stress were estimated by proinflammatory cytokines and generation of MDA and reactive oxygen species (ROS). ABLIM1 was downregulated in DVT rats. Overexpressing ABLIM1 could suppress the formation of thrombosis and alleviate inflammation and oxidative stress. In HUVECs, ox-LDL induced significantly increased miR-2467-3p and decreased ABLIM1, and miR-2467-3p could negatively regulate ABLIM1. The knockdown of miR-2467-3p could alleviate the inhibited cell growth and motility by ox-LDL, and the inflammation and oxidative stress were also attenuated. While silencing could reverse the effect of miR-2467-3p on ox-LDL-induced HUVECs. The miR-2467-3p/ABLIM1 axis regulates the occurrence and development of DVT through modulating HUVECs inflammation and oxidative stress.

Analysis and validation of hub genes in neutrophil extracellular traps for the long-term prognosis of myocardial infarction

INTRODUCTION

The study focuses on the long-term prognosis of myocardial infarction (MI) influenced by neutrophil extracellular traps (NETs). It also aims to analyze and validate relative hub genes in this process, in order to further explore new therapeutic targets that can improve the prognosis of MI.

MATERIALS AND METHODS

We established a MI model in mice by ligating the left anterior descending branch (LAD) and conducted an 8-week continuous observation to study the dynamic changes in the structure and function of the heart in these mice. Meanwhile, we administered Apocynin, an inhibitor of NADPH Oxidase, which has also been shown to inhibit the formation of NETs, to mice undergoing MI surgery in order to compare. This study employed hematoxylin-eosin (HE) staining, echocardiography, immunofluorescence, and real-time quantitative PCR (RT-qPCR) to examine the impact of NETs on the long-term prognosis of MI. Next, datasets related to MI and NETs were downloaded from the GEO database, respectively. The Limma package of R software was used to identify differentially expressed genes (DEGs). After analyzing the "Robust Rank Aggregation (RRA)" package, we conducted a screening for robust differentially expressed genes (DEGs) and performed pathway enrichment analysis using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) to determine the functional roles of these robust DEGs. The protein-protein interaction (PPI) network was visualized and hub genes were filtered using Cytoscape.

RESULTS

Immunofluorescence and qPCR results showed an increase in the expression of Myeloperoxidase (MPO) at week 1 and week 8 in the hearts of mice after MI. HE staining reveals a series of pathological manifestations in the heart of the MI group during 8 weeks, including enlarged size, disordered arrangement of cardiomyocytes, infiltration of inflammatory cells, and excessive deposition of collagen fibers, among others. The utilization of Apocynin could significantly improve these poor performances. The echocardiography displayed the cardiac function of the heart in mice. The MI group has a reduced range of heart movement and decreased ejection ability. Moreover, the ventricular systolic movement was found to be abnormal, and its wall thickening rate decreased over time, indicating a progressive worsening of myocardial ischemia. The Apocynin group, on the contrary, showed fewer abnormal changes in the aforementioned aspects. A total of 81 DEGs and 4 hub genes (FOS, EGR1, PTGS2, and HIST1H4H) were obtained. The results of RT-qPCR demonstrated abnormal expression of these four genes in the MI group, which could be reversed by treatment of Apocynin.

CONCLUSION

The NETs formation could be highly related to MI and the long-term prognosis of MI can be significantly influenced by the NETs formation. Four hub genes, namely FOS, EGR1, PTGS2, and HIST1H4H, have the potential to be key genes related to this process. They could also serve as biomarkers for predicting MI prognosis and as targets for gene therapy.