Identification of immune-related hub genes and miRNA-mRNA pairs involved in immune infiltration in human septic cardiomyopathy by bioinformatics analysis

Exploration and validation of signature genes and immune associations in septic cardiomyopathy

An early and accurate diagnosis of septic cardiomyopathy is vital for improving the overall prognosis of sepsis. In our research, we aimed to identify signature genes and their immune connections in septic cardiomyopathy. By analyzing the mouse myocardial transcriptome from sepsis induced by cecum ligation and puncture (CLP), we identified four distinct k-means clusters. Further analysis of human myocardial datasets using Weighted Gene Co-expression Network Analysis (WGCNA) revealed a strong correlation between the MEturquoise module and septic cardiomyopathy (cor = 0.79, p < .001). Through the application of Cytoscape plug-in MCODE and comprehensive analysis, we pinpointed two signature genes, THBS1 and TIMP1. These genes demonstrated significant involvement in immune cell infiltration, as detected by CIBERSORT, and displayed promising prognostic potential as validated by external datasets. Our experimental validation confirmed the up-regulation of both THBS1 and TIMP1 in septic murine hearts, underscoring their positive association with septic cardiomyopathy.

Integrated analysis and validation of ferroptosis-related genes and immune infiltration in acute myocardial infarction

BACKGROUND

Acute myocardial infarction (AMI) is indeed a significant cause of mortality and morbidity in individuals with coronary heart disease. Ferroptosis, an iron-dependent cell death, is characterized by the accumulation of intracellular lipid peroxides, which is implicated in cardiomyocyte injury. This study aims to identify biomarkers that are indicative of ferroptosis in the context of AMI, and to examine their potential roles in immune infiltration.

METHODS

Firstly, the GSE59867 dataset was used to identify differentially expressed ferroptosis-related genes (DE-FRGs) in AMI. We then performed gene ontology (GO) and functional enrichment analysis on these DE-FRGs. Secondly, we analyzed the GSE76591 dataset and used bioinformatic methods to build ceRNA networks. Thirdly, we identified hub genes in protein-protein interaction (PPI) network. After obtaining the key DE-FRGs through the junction of hub genes with ceRNA and least absolute shrinkage and selection operator (LASSO). ImmucellAI was applied to estimate the immune cell infiltration in each sample and examine the relationship between key DE-FRGs and 24 immunocyte subsets. The diagnostic performance of these genes was further evaluated using the receiver operating characteristic (ROC) curve analysis. Ultimately, we identified an immune-related ceRNA regulatory axis linked to ferroptosis in AMI.

RESULTS

Among 56 DE-FRGs identified in AMI, 41 of them were integrated into the construction of competitive endogenous RNA (ceRNA) networks. TLR4 and PIK3CA were identified as key DE-FRGs and PIK3CA was confirmed as a diagnostic biomarker for AMI. Moreover, CD4_native cells, nTreg cells, Th2 cells, Th17 cells, central-memory cells, effector-memory cells, and CD8_T cells had higher infiltrates in AMI samples compared to control samples. In contrast, exhausted cells, iTreg cells, and Tfh cells had lower infiltrates in AMI samples. Spearman analysis confirmed the correlation between 24 immune cells and PIK3CA/TLR4. Ultimately, we constructed an immune-related regulatory axis involving XIST and OIP5-AS1/miR-216a/PIK3CA.

CONCLUSION

Our comprehensive analysis has identified PIK3CA as a robust and promising biomarker for this condition. Moreover, we have also identified an immune-related regulatory axis involving XIST and OIP5-AS1/miR-216a/PIK3CA, which may play a key role in regulating ferroptosis during AMI progression.

Lymphocyte to monocyte ratio predicts survival and is epigenetically linked to miR-222-3p and miR-26b-5p in diffuse large B cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma. 10-20% of the patients present with bone marrow (BM) involvement which predicts a worse survival. This study aimed to determine the prognostic significance of serum miR-222-3p, miR-26b-5p, EBV-miR-BHRF1-2-5p, and EBV-miR-BHRF1-2-3p and correlate their levels to clinical and haematological markers in DLBCL with special emphasis on the lymphocyte-monocyte ratio (LMR) and neutrophil-monocyte ratio. We also studied the role of BM BMI1 and PIM2 proteins in predicting BM infiltration. Serum miRNAs were studied on 40 DLBCL and 18 normal individuals using qRT-PCR. BMI1 and PIM2 proteins were studied on BM biopsies by immunohistochemistry. The results were correlated with clinical and follow-up data. All the studied miRNAs were dysregulated in DLBCL serum samples. BMI1 and PIM2 were expressed in 67% and 77.5% of BM samples, respectively. LMR was significantly associated with disease-free survival (DFS) (P = 0.022), miR-222-3P (P = 0.043), and miR-26b-5p (P = 0.043). EBV-miR-BHRF1-2-3p was significantly correlated to haemoglobin level (P = 0.027). MiR-222-3p, miR-26b-5p, and EBV-miR-BHRF1-2-5p expressions were significantly correlated to each other (P = 0.001). There was no significant correlation between the studied markers and follow-up data. LMR is a simple method for predicting survival in DLBCL. MiR-222-3p and miR-26b-5p may be implicated in an immunological mechanism affecting patients' immunity and accordingly influence LMR. The correlation between miR-222-3p, miR-26b-5p, and EBV-miR-BHRF1-2-5p may indicate a common mechanism among the 3 miRNAs that may explain DLBCL pathogenesis.