Construction of a pyroptosis-related classifier for risk prediction of acute myocardial infarction

Inhibition of mir-155-5p alleviates cardiomyocyte pyroptosis induced by hypoxia/reoxygenation via targeting SIRT1-mediated activation of the NLRP3 inflammasome

OBJECTIVE

The hypoxia/reoxygenation (H/R)-induced pyroptosis of cardiomyocytes plays a crucial role in the pathogenesis of myocardial infarction (MI). miR-155-5p represents a promising target for MI therapy. However, its involvement in H/R-induced pyroptosis remains unclear.

METHODS

The H/R exposed rat cardiomyocyte H9c2 was utilized as in vitro model, and the expression levels of miR-155-5p and SIRT1 in cells were modulated through cell transfection experiments. Cell proliferative activity was assessed using the Cell counting kit-8 assay. Supernatant lactate dehydrogenase (LDH) activity was determined through colorimetry. The levels of living and dead cell were observed via Calcin-AM/PI staining. Levels of supernatant interleukin (IL)-1β and IL-18 were measured using ELISA assay. The expression levels of miR-155-5p and silent information regulator 1 (SIRT1) mRNA were detected by qRT-PCR. The protein expression levels of SIRT1, NLRP3, N-terminal gasdermin D (GSDMD-N), and Cleaved caspase-1 were evaluated using Western blot analysis. The targeted regulatory relationship between miR-155-5p and SIRT1 was verified using dual luciferase reporter gene assay.

RESULTS

The proliferation activity of H9c2 cells induced by H/R was attenuated, accompanied by severe injury, increased cell death, and the release of a substantial amount of pro-inflammatory cytokines IL-1β and IL-18. In addition, H/R stimulation resulted in the upregulation of miR-155-5p expression and downregulation of SIRT1 expression in H9c2 cells. Suppression of miR-155-5p or overexpression of SIRT1 exhibited ameliorative effects on H/R-induced cellular injury in H9c2 cells and inhibited NLRP3 inflammasome-mediated pyroptosis. The dual-luciferase assay confirmed the direct targeting of SIRT1 by miR-155-5p in H9c2 cells. Furthermore, partial reversal of the inhibitory effect of miR-155-5p inhibitor on H/R-induced NLRP3 inflammasome-mediated pyroptosis in H9c2 cells was observed upon interference with SIRT1 expression.

CONCLUSION

Inhibition of miR-155-5p alleviates cardiomyocyte pyroptosis induced by H/R via targeting SIRT1-mediated activation of the NLRP3 inflammasome.

NOD1: a metabolic modulator

Nucleotide-binding oligomerization domain 1 (NOD1) is an intracellular pattern recognition receptor that detects injury signals and initiates inflammatory responses and host defense. Furthermore, NOD1 serves as a metabolic mediator by influencing the metabolism of various tissues, including adipose tissue, liver, cardiovascular tissue, pancreatic β cells, adrenal glands, and bones through diverse mechanisms. It has been discovered that activated NOD1 is associated with the pathological mechanisms of certain metabolic diseases. This review presents a comprehensive summary of the impact of NOD1 on tissue-specific metabolism.

The cytoplasmic sensor, the AIM2 inflammasome: A precise therapeutic target in vascular and metabolic diseases

Cardio-cerebrovascular diseases encompass pathological changes in the heart, brain and vascular system, which pose a great threat to health and well-being worldwide. Moreover, metabolic diseases contribute to and exacerbate the impact of vascular diseases. Inflammation is a complex process that protects against noxious stimuli but is also dysregulated in numerous so-called inflammatory diseases, one of which is atherosclerosis. Inflammation involves multiple organ systems and a complex cascade of molecular and cellular events. Numerous studies have shown that inflammation plays a vital role in cardio-cerebrovascular diseases and metabolic diseases. The absent in melanoma 2 (AIM2) inflammasome detects and is subsequently activated by double-stranded DNA in damaged cells and pathogens. With the assistance of the mature effector molecule caspase-1, the AIM2 inflammasome performs crucial biological functions that underpin its involvement in cardio-cerebrovascular diseases and related metabolic diseases: The production of interleukin-1 beta (IL-1β), interleukin-18 (IL-18) and N-terminal pore-forming Gasdermin D fragment (GSDMD-N) mediates a series of inflammatory responses and programmed cell death (pyroptosis and PANoptosis). Currently, several agents have been reported to inhibit the activity of the AIM2 inflammasome and have the potential to be evaluated for use in clinical settings. In this review, we systemically elucidate the assembly, biological functions, regulation and mechanisms of the AIM2 inflammasome in cardio-cerebrovascular diseases and related metabolic diseases and outline the inhibitory agents of the AIM2 inflammasome as potential therapeutic drugs.

A novel pyroptosis scoring model was associated with the prognosis and immune microenvironment of esophageal squamous cell carcinoma

The phenotype of pyroptosis has been extensively studied in a variety of tumors, but the relationship between pyroptosis and esophageal squamous cell carcinoma (ESCC) remains unclear. Here, 22 pyroptosis genes were downloaded from the website of Gene Set Enrichment Analysis (GSEA), 79 esophageal squamous cell carcinoma samples and GSE53625 containing 179 pairs of esophageal squamous cell carcinoma samples were collected from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO), respectively. Then, pyroptosis subtypes of esophageal squamous cell carcinoma were obtained by cluster analysis according to the expression difference of pyroptosis genes, and a pyroptosis scoring model was constructed by the pyroptosis-related genes screened from different pyroptosis subtypes. Time-dependent receiver operator characteristic (timeROC) curves and the area under the curve (AUC) values were used to evaluate the prognostic predictive accuracy of the pyroptosis scoring model. Kaplan-Meier method with log-rank test were conducted to analyze the impact of the pyroptosis scoring model on overall survival (OS) of patients with esophageal squamous cell carcinoma. Nomogram models and calibration curves were used to further confirm the effect of the pyroptosis scoring model on prognosis. Meanwhile, CIBERSORTx and ESTIMATE algorithm were applied to calculate the influence of the pyroptosis scoring model on esophageal squamous cell carcinoma immune microenvironment. Our findings revealed that the pyroptosis scoring model established by the pyroptosis-related genes was associated with the prognosis and immune microenvironment of esophageal squamous cell carcinoma, which can be used as a biomarker to predict the prognosis and act as a potential target for the treatment of esophageal squamous cell carcinoma.

The AIM2 inflammasome: A novel biomarker and target in cardiovascular disease

Absent in melanoma 2 (AIM2) is a cytoplasmic sensor that recognises the double-strand DNA. AIM2 inflammasome is a protein platform in the cell that initiates innate immune responses by cleaving pro-caspase-1 and converting IL-1β and IL-18 to their mature forms. Additionally, AIM2 inflammasome promotes pyroptosis by converting Gasdermin-D (GSDMD) to GSDMD-N fragments. An increasing number of studies have indicated the important and decisive roles of the AIM2 inflammasome, IL-1β, and pyroptosis in cardiovascular diseases, such as coronary atherosclerosis, myocardial infarction, ischaemia/reperfusion injury, heart failure, aortic aneurysm and ischaemic stroke. Here, we review the molecular mechanism of the activation and effect of the AIM2 inflammasome in cardiovascular disease, revealing new insights into pathogenic factors that may be targeted to treat cardiovascular disease and related dysfunctions.

Identification of Five Hub Genes Based on Single-Cell RNA Sequencing Data and Network Pharmacology in Patients With Acute Myocardial Infarction

Acute myocardial infarction (AMI) has a high mortality. The single-cell RNA sequencing (scRNA-seq) method was used to analyze disease heterogeneity at the single-cell level. From the Gene Expression Omnibus (GEO) database (GSE180678), AMI scRNA-seq were downloaded and preprocessed by the Seurat package. Gene expression data came from GSE182923. Cell cluster analysis was conducted. Cell types were identified. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were performed on hub genes. Drugs were predicted by protein–protein interaction (PPI) and molecular docking. In total, 7 cell clusters were defined based on the scRNA-seq dataset, and the clusters were labeled as 5 cell types by marker genes. Hematopoietic stem cell types as a differential subgroups were higher in AMI than in healthy tissues. From available databases and PPI analysis, 52 common genets were identified. Based on 52 genes, 5 clusters were obtained using the MCODE algorithm, and genes in these 5 clusters involved in immune and inflammatory pathways were determined. Correlation analysis showed that hematopoietic stem cell types were negatively correlated with ATM, CARM1, and CASP8 but positively correlated with CASP3 and PPARG. This was reversed with immune cells. Molecular docking analysis showed that DB05490 had the lowest docking score with PPARG. We identified 5 hub genes (ATM, CARM1, CASP8, CASP3, and PPARG) involved in AMI progression. Compound DB05490 was a potential inhibitor of PPAG.