Analysis of the potential ferroptosis mechanism and multitemporal expression change of central ferroptosis-related genes in cardiac ischemia–reperfusion injury

Protective effect of Pinacidil on hypoxic-reoxygenated cardiomyocytes in vitro and in vivo via HIF-1α/HRE pathway

Cardiomyocyte hypoxia-reoxygenation (HR) is considered as a major cause of heart failure. Pinacidil is a classic ATP sensitive potassium channel opener and plays a crucial role in cardiomyocyte HR injuries. However, the specific mechanism is poorly understood. We established HR rat model and introduced 5-Hydroxydecanoate (5-HD), N-(2-Mercaptopropionyl)-glycine (MPG), and Dimethylethylenediylglycine (DMOG) to investigate the protection of Pinacidil (P) on cardiomyocyte. HE staining, electron microscopy and JC-1 staining were used to observe mitochondrial structure and mitochondrial membrane potential (MMP). Reactive oxygen species (ROS), hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor A (VEGF-A), heme oxygenase-1 (HO-1), and induced nitric oxide synthase (iNOS) were analyzed in this study. Network pharmacology analysis and auto-docking were used to predict the possible target of Pinadicil under cardiomyocyte HR condition. The integrity of mitochondrial structure and MMP were effectively promoted in P and MPG+DMOG + P groups. ROS was significantly increased after HR, treatment with P or MPG+DMOG + P, the content of ROS was increased. The expressions of HIF-1α, VEGF-A, HO-1 and iNOS were significantly increased in P and MPG+DMOG + P groups compared with HR group. Docking results confirmed that prolyl hydroxylase (PHD) was the most possible target for unsaturated binding with Pinacidil guanidine. Altogether, these data indicate that Pinacidil up-regulated and activated HIF-1α protein to protect caridomyocytes against HR injuries and the mechanism may be related to Pinacidil guanidine binding to PHD.

MicroRNAs and angiosarcoma: are there promising reports?

In recent years, microRNAs (miRNAs) have garnered increasing attention for their potential implications in cancer pathogenesis, functioning either as oncogenes or tumor suppressors. Notably, angiosarcoma, along with various other cardiovascular tumors such as lipomas, rhabdomyomas, hemangiomas, and myxomas, has shown variations in the expression of specific miRNA subtypes. A substantial body of evidence underscores the pivotal involvement of miRNAs in the genesis of angiosarcoma and certain cardiovascular tumors. This review aims to delve into the current literature on miRNAs and their prospective applications in cardiovascular malignancies, with a specific focus on angiosarcoma. It comprehensively covers diagnostic methods, prognostic evaluations, and potential treatments while providing a recapitulation of angiosarcoma's risk factors and molecular pathogenesis, with an emphasis on the role of miRNAs. These insights can serve as the groundwork for designing randomized control trials, ultimately facilitating the translation of these findings into clinical applications. Moving forward, it is imperative for studies to thoroughly scrutinize the advantages and disadvantages of miRNAs compared to current diagnostic and prognostic approaches in angiosarcoma and other cardiovascular tumors. Closing these knowledge gaps will be crucial for harnessing the full potential of miRNAs in the realm of angiosarcoma and cardiovascular tumor research.

Transcriptomic analysis reveals the lipid metabolism-related gene regulatory characteristics and potential therapeutic agents for myocardial ischemia-reperfusion injury

Background

Impaired energy balance caused by lipid metabolism dysregulation is an essential mechanism of myocardial ischemia-reperfusion injury (MI/RI). This study aims to explore the lipid metabolism-related gene (LMRG) expression patterns in MI/RI and to find potential therapeutic agents.

Methods

Differential expression analysis was performed to screen the differentially expressed genes (DEGs) and LMRGs in the MI/RI-related dataset GSE61592. Enrichment and protein-protein interaction (PPI) analyses were performed to identify the key signaling pathways and genes. The expression trends of key LMRGs were validated by external datasets GSE160516 and GSE4105. The corresponding online databases predicted miRNAs, transcription factors (TFs), and potential therapeutic agents targeting key LMRGs. Finally, the identified LMRGs were confirmed in the H9C2 cell hypoxia-reoxygenation (H/R) model and the mouse MI/RI model.

Results

Enrichment analysis suggested that the "lipid metabolic process" was one of the critical pathways in MI/RI. Further differential expression analysis and PPI analysis identified 120 differentially expressed LMRGs and 15 key LMRGs. 126 miRNAs, 55 TFs, and 51 therapeutic agents were identified targeting these key LMRGs. Lastly, the expression trends of Acadm, Acadvl, and Suclg1 were confirmed by the external datasets, the H/R model and the MI/RI model.

Conclusion

Acadm, Acadvl, and Suclg1 may be the key genes involved in the MI/RI-related lipid metabolism dysregulation; and acting upon these factors may serve as a potential therapeutic strategy.

Integrative analyses and validation of ferroptosis-related genes and mechanisms associated with cerebrovascular and cardiovascular ischemic diseases

BACKGROUND

There has been a gradual increase in the occurrence of cardiovascular and cerebrovascular ischemic diseases, particularly as comorbidities. Yet, the mechanisms underlying these diseases remain unclear. Ferroptosis has emerged as a potential contributor to cardio-cerebral ischemic processes. Therefore, this study investigated the shared biological mechanisms between the two processes, as well as the role of ferroptosis genes in cardio-cerebral ischemic damage, by constructing co-expression modules for myocardial ischemia (MI) and ischemic stroke (IS) and a network of protein-protein interactions, mRNA-miRNA, mRNA-transcription factors (TFs), mRNA-RNA-binding proteins (RBPs), and mRNA-drug interactions.

RESULTS

The study identified seven key genes, specifically ACSL1, TLR4, ADIPOR1, G0S2, PDK4, HP, PTGS2, and subjected them to functional enrichment analysis during ischemia. The predicted miRNAs were found to interact with 35 hub genes, and interactions were observed between 11 hub genes and 30 TF transcription factors. Additionally, 10 RBPs corresponding to 16 hub genes and 163 molecular compounds corresponding to 30 hub genes were identified. This study also clarified the levels of immune infiltration between MI and IS and different subtypes. Finally, we identified four hub genes, including TLR4, by using a diagnostic model constructed by Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis; ADIPOR1, G0S2, and HP were shown to have diagnostic value for the co-pathogenesis of MI and cerebral ischemia by both validation test data and RT-qPCR assay.

CONCLUSIONS

To the best our knowledge, this study is the first to utilize multiple algorithms to comprehensively analyze the biological processes of MI and IS from various perspectives. The four hub genes, TLR4, ADIPOR1, G0S2, and HP, have proven valuable in offering insights for the investigation of shared injury pathways in cardio-cerebral injuries. Therefore, these genes may serve as diagnostic markers for cardio-cerebral ischemic diseases.

Development and Validation of Robust Ferroptosis-Related Genes in Myocardial Ischemia-Reperfusion Injury

(1) Background: Despite the evidence that ferroptosis is involved in myocardial ischemia-reperfusion (MIR), the critical regulator of ferroptosis in MIR remains unclear. (2) Methods: We included three GEO datasets and a set of ferroptosis-related genes with 259 genes. Following the identification of the differentially expressed ferroptosis-related genes (DEFRGs) and hub genes, we performed the functional annotation, protein-protein interaction network, and immune infiltration analysis. The GSE168610 dataset, a cell model, and an animal model were then used to verify key genes. (3) Results: We identified 17 DEFRGs and 9 hub genes in the MIR samples compared to the control. Heme oxygenase 1 (Hmox1), activating transcription factor 3 (Atf3), epidermal growth factor receptor (Egfr), and X-box binding protein 1 (Xbp1) were significantly upregulated in response to ischemic and hypoxic stimuli. In contrast, glutathione peroxidase 4 (Gpx4) and vascular endothelial growth factor A (Vegfa) were consistently decreased in either the oxygen and glucose deprivation/reoxygenation cell or the MIR mouse model. (4) Conclusions: This study emphasized the relevance of ferroptosis in MIR. It has been successfully demonstrated that nine ferroptosis-related genes (Hmox1, Atf3, Egfr, Gpx4, Cd44, Vegfa, asparagine synthetase (Asns), Xbp1, and bromodomain containing 4 (Brd4)) are involved in the process. Additional studies are needed to explore potential therapeutic targets for MIR.

GADD45A and GADD45B as Novel Biomarkers Associated with Chromatin Regulators in Renal Ischemia-Reperfusion Injury

Chromatin regulators (CRs) are essential upstream regulatory factors of epigenetic modification. The role of CRs in the pathogenesis of renal ischemia-reperfusion injury (IRI) remains unclear. We analyzed a bioinformatic analysis on the differentially expressed chromatin regulator genes in renal IRI patients using data from public domains. The hub CRs identified were used to develop a risk prediction model for renal IRI, and their expressions were also validated using Western blot, qRT-PCR, and immunohistochemistry in a murine renal IRI model. We also examined the relationships between hub CRs and infiltrating immune cells in renal IRI and used network analysis to explore drugs that target hub CRs and their relevant downstream microRNAs. The results of machine learning methods showed that five genes (DUSP1, GADD45A, GADD45B, GADD45G, HSPA1A) were upregulated in renal IRI, with key roles in the cell cycle, p38 MAPK signaling pathway, p53 signaling pathway, FoxO signaling pathway, and NF-κB signaling pathway. Two genes from the network, GADD45A and GADD45B (growth arrest and DNA damage-inducible protein 45 alpha and beta), were chosen for the renal IRI risk prediction model. They all showed good performance in the testing and validation cohorts. Mice with renal IRI showed significantly upregulated GADD45A and GADD45B expression within kidneys compared to sham-operated mice. GADD45A and GADD45B showed correlations with plasmacytoid dendritic cells (pDCs) in infiltrating immune cell analysis and enrichment in the MAPK pathway based on the weighted gene co-expression network analysis (WGCNA) method. Candidate drugs that target GADD45A and GADD45B include beta-escin, sertraline, primaquine, pimozide, and azacyclonol. The dysregulation of GADD45A and GADD45B is related to renal IRI and the infiltration of pDCs, and drugs that target GADD45A and GADD45B may have therapeutic potential for renal IRI.

Ferroptosis Regulated by Hypoxia in Cells

Ferroptosis is an oxidative damage-related, iron-dependent regulated cell death with intracellular lipid peroxide accumulation, which is associated with many physiological and pathological processes. It exhibits unique features that are morphologically, biochemically, and immunologically distinct from other regulated cell death forms. Ferroptosis is regulated by iron metabolism, lipid metabolism, anti-oxidant defense systems, as well as various signal pathways. Hypoxia, which is found in a group of physiological and pathological conditions, can affect multiple cellular functions by activation of the hypoxia-inducible factor (HIF) signaling and other mechanisms. Emerging evidence demonstrated that hypoxia regulates ferroptosis in certain cell types and conditions. In this review, we summarize the basic mechanisms and regulations of ferroptosis and hypoxia, as well as the regulation of ferroptosis by hypoxia in physiological and pathological conditions, which may contribute to the numerous diseases therapies.

Expression Pattern and Molecular Mechanism of Oxidative Stress-Related Genes in Myocardial Ischemia-Reperfusion Injury

(1) Background: The molecular mechanism of oxidative stress-related genes (OSRGs) in myocardial ischemia-reperfusion injury (MIRI) has not been fully elucidated. (2) Methods: Differential expression analysis, enrichment analysis, and PPI analysis were performed on the MIRI-related datasets GSE160516 and GSE61592 to find key pathways and hub genes. OSRGs were obtained from the Molecular Signatures Database (MSigDB). The expression pattern and time changes of them were studied on the basis of their raw expression data. Corresponding online databases were used to predict miRNAs, transcription factors (TFs), and therapeutic drugs targeting common differentially expressed OSRGs. These identified OSRGs were further verified in the external dataset GSE4105 and H9C2 cell hypoxia-reoxygenation (HR) model. (3) Results: A total of 134 DEGs of MIRI were identified which were enriched in the pathways of "immune response", "inflammatory response", "neutrophil chemotaxis", "phagosome", and "platelet activation". Six hub genes and 12 common differentially expressed OSRGs were identified. A total of 168 miRNAs, 41 TFs, and 21 therapeutic drugs were predicted targeting these OSRGs. Lastly, the expression trends of Aif1, Apoe, Arg1, Col1a1, Gpx7, and Hmox1 were confirmed in the external dataset and HR model. (4) Conclusions: Aif1, Apoe, Arg1, Col1a1, Gpx7, and Hmox1 may be involved in the oxidative stress mechanism of MIRI, and the intervention of these genes may be a potential therapeutic strategy.

Dapagliflozin alleviates myocardial ischemia/reperfusion injury by reducing ferroptosis via MAPK signaling inhibition

Reperfusion is essential for ischemic myocardium but paradoxically leads to myocardial damage that worsens cardiac functions. Ferroptosis often occurs in cardiomyocytes during ischemia/reperfusion (I/R). The SGLT2 inhibitor dapagliflozin (DAPA) exerts cardioprotective effects independent of hypoglycemia. Here, we investigated the effect and potential mechanism of DAPA against myocardial ischemia/reperfusion injury (MIRI)-related ferroptosis using the MIRI rat model and hypoxia/reoxygenation (H/R)-induced H9C2 cardiomyocytes. Our results show that DAPA significantly ameliorated myocardial injury, reperfusion arrhythmia, and cardiac function, as evidenced by alleviated ST-segment elevation, ameliorated cardiac injury biomarkers including cTnT and BNP and pathological features, prevented H/R-triggered cell viability loss in vitro. In vitro and in vivo experiments showed that DAPA inhibited ferroptosis by upregulating the SLC7A11/GPX4 axis and FTH and inhibiting ACSL4. DAPA notably mitigated oxidative stress, lipid peroxidation, ferrous iron overload, and reduced ferroptosis. Subsequently, network pharmacology and bioinformatics analysis suggested that the MAPK signaling pathway was a potential target of DAPA and a common mechanism of MIRI and ferroptosis. DAPA treatment significantly reduced MAPK phosphorylation in vitro and in vivo, suggesting that DAPA might protect against MIRI by reducing ferroptosis through the MAPK signaling pathway.

Bioinformatics analysis of genes related to ferroptosis in hepatic ischemia-reperfusion injury

Background: Primary liver cancer is the sixth most commonly diagnosed cancer and the third leading cause of cancer death worldwide in 2020, and it ranks fifth in global incidence. Liver resection or liver transplantation are the two most prominent surgical procedures for treating primary liver cancer. Both inevitably result in HIRI, causing severe complications for patients and affecting their prognosis and quality of survival. Ferroptosis, a newly discovered mode of cell death, is closely related to HIRI. We used bioinformatics analysis to explore the relationship between the two further. Methods: The GEO database dataset GSE112713 and the FerrDB database data were selected to use bioinformatic analysis methods (difference analysis, FRGs identification, GO analysis, KEGG analysis, PPI network construction and analysis, Hub gene screening with GO analysis and KEGG analysis, intergenic interaction prediction, drug-gene interaction prediction, miRNA prediction) for both for correlation analysis. The GEO database dataset GSE15480 was selected for preliminary validation of the screened Hub genes. Results: We analysed the dataset GSE112713 for differential gene expression before and after hepatic ischemia-reperfusion and identified by FRGs, yielding 11 genes. These 11 genes were subjected to GO, and KEGG analyses, and PPI networks were constructed and analysed. We also screened these 11 genes again to obtain 5 Hub genes and performed GO analysis, KEGG analysis, intergenic interaction prediction, drug-gene interaction prediction, and miRNA prediction on these 5 Hub genes. Finally, we obtained preliminary validation of all these 5 Hub genes by dataset GSE15480. Conclusion: There is a close relationship between HIRI and ferroptosis, and inhibition of ferroptosis can potentially be a new approach to mitigate HIRI treatment in the future.