Clinical value of BRE-AS1 in myocardial infarction and its role in myocardial infarction-induced cardiac muscle cell apoptosis.

Objectives. The aim of this study was to investigate the expression of long non-coding RNA (lncRNA) brain and reproductive organ-expressed protein (BRE) antisense RNA 1 (BRE-AS1) in patients with acute myocardial infarction (AMI) and its effect on ischemia/reperfusion (I/R)-induced oxidative stress and apoptosis of cardiomyocytes. Methods. Serum BRE-AS1 levels in patients with AMI was detected using quantitative real-time polymerase chain reaction (qRT-PCR). The diagnostic and prognostic values of BRE-AS1 were evaluated. H9c2 cells were treated with hypoxia/reoxygenation to establish an in vitro myocardial infarction cell model. The levels of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and IL-6 were detected by enzyme-linked immunosorbent assay (ELISA). Levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were determined by commercial kits. Cell counting kit-8 (CCK-8) and flow cytometry were used to evaluate the cell viability and cell apoptosis. Results. The expression of BRE-AS1 in serum of patients with AMI is upregulated, which shows the clinical diagnostic value for AMI. In the I/R injury cell model, the knockout of BRE-AS1 can significantly alleviate the increase in TNF-α, IL-1ß, and IL-6 levels, inhibit the production of LDH and MDA, increase the activities of SOD and GSH-Px, promote the cell viability and suppress cell apoptosis. Conclusions. Abnormally elevated BRE-AS1 has a high diagnostic value for AMI as well as a prognostic value for major adverse cardiovascular events (MACEs). The elevation of BRE-AS1 promoted oxidative stress injury and cell apoptosis in vitro.

Dynamic molecular signatures of acute myocardial infarction based on transcriptomics and metabolomics.

Acute myocardial infarction (AMI) commonly precedes ventricular remodeling, heart failure. Few dynamic molecular signatures have gained widespread acceptance in mainstream clinical testing despite the discovery of many potential candidates. These unmet needs with respect to biomarker and drug discovery of AMI necessitate a prioritization. We enrolled patients with AMI aged between 30 and 70. RNA-seq analysis was performed on the peripheral blood mononuclear cells collected from the patients at three time points: 1 day, 7 days, and 3 months after AMI. PLC/LC-MS analysis was conducted on the peripheral blood plasma collected from these patients at the same three time points. Differential genes and metabolites between groups were screened by bio-informatics methods to understand the dynamic changes of AMI in different periods. We obtained 15 transcriptional and 95 metabolite expression profiles at three time points after AMI through high-throughput sequencing. AMI-1d: enrichment analysis revealed the biological features of 1 day after AMI primarily included acute inflammatory response, elevated glycerophospholipid metabolism, and decreased protein synthesis capacity. Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) might stand promising biomarkers to differentiate post-AMI stage. Anti-inflammatory therapy during the acute phase is an important direction for preventing related pathology. AMI-7d: the biological features of this stage primarily involved the initiation of cardiac fibrosis response and activation of platelet adhesion pathways. Accompanied by upregulated TGF-beta signaling pathway and ECM receptor interaction, GP5 help assess platelet activation, a potential therapeutic target to improve haemostasis. AMI-3m: the biological features of 3 months after AMI primarily showed a vascular regeneration response with VEGF signaling pathway, NOS3 and SHC2 widely activated, which holds promise for providing new therapeutic approaches for AMI. Our analysis highlights transcriptional and metabolomics signatures at different time points after MI, which deepens our understanding of the dynamic biological responses and associated molecular mechanisms that occur during cardiac repair.

[A transcriptomic analysis of correlation between mitochondrial function and energy metabolism remodeling in mice with myocardial fibrosis following myocardial infarction].

OBJECTIVE: To investigate the changes of mitochondrial respiratory function during myocardial fibrosis in mice with myocardial infarction (MI) and its correlation with the increase of glycolytic flux. METHODS: Forty C57BL/6N mice were randomized into two equal groups to receive sham operation or ligation of the left anterior descending coronary artery to induce acute MI. At 28 days after the operation, 5 mice from each group were euthanized and left ventricular tissue samples were collected for transcriptomic sequencing. FPKM method was used to calculate gene expression levels to identify the differentially expressed genes (DEGs) in MI mice, which were analyzed using GO and KEGG databases to determine the pathways affecting the disease process. Heat maps were drawn to show the differential expressions of the pathways and the related genes in the enrichment analysis. In primary cultures of neonatal mouse cardiac fibroblasts (CFs), the changes in mitochondrial respiration and glycolysis levels in response to treatment with the pro-fibrotic agonist TGF-ß1 were analyzed using Seahorse experiment. RESULTS: The mouse models of MI showed significantly increased diastolic and systolic left ventricular diameter (P < 0.05) and decreased left ventricular ejection fraction (P < 0.0001). A total of 124 up-regulated and 106 down-regulated DEGs were identified in the myocardial tissues of MI mice, and GO and KEGG enrichment analysis showed that these DEGs were significantly enriched in fatty acid metabolism, organelles and other metabolic pathways and in the mitochondria. Heat maps revealed fatty acid beta oxidation, mitochondrial dysfunction and increased glycolysis levels in MI mice. In the primary culture of CFs, treatment with TGF-ß1 significantly reduced the basal and maximum respiratory levels and increased the basal and maximum glycolysis levels (P < 0.0001). CONCLUSION: During myocardial fibrosis, energy metabolism remodeling occurs in the CFs, manifested by lowered mitochondrial function and increased energy generation through glycolysis.

miR-30a-5p attenuates hypoxia/reoxygenation-induced cardiomyocyte apoptosis by regulating PTEN protein expression and activating PI3K/Akt signaling pathway.

BACKGROUND: This study was designed to investigate the mechanism by which miR-30a-5p mediates cardiomyocyte apoptosis after acute myocardial infarction (AMI) induced by hypoxia/reoxygenation (H/R). METHODS: Differentially expressed miRNAs were analyzed by RNA high-throughput sequencing in acute myocardial infarction (ST-elevation myocardial infarction) patients versus healthy individuals (controls). The H/R model was used to assess the regulatory mechanism of miRNAs in AMI. Lentivirus-associated vectors were used to overexpress or knock down miR-30a-5p in cellular models. The pathological mechanisms of miR-30a-5p regulating the development of acute myocardial infarction were serially explored by qPCR, bioinformatics, target gene prediction, dual luciferase, enzyme-linked immunosorbent assays (ELISAs) and Western blotting. RESULTS: The results showed that the expression of miR-30a-5p was significantly increased in AMI patients and H9C2 cells. Hypoxia decreased cardiomyocyte survival over time, and reoxygenation further reduced cell survival. Bax and Phosphatase and tensin homolog (PTEN)were suppressed, while Bcl-2 was upregulated. Additionally, miR-30a-5p specifically targeted the PTEN gene. According to the GO and KEGG analyses, miR-30a-5p may participate in apoptosis by interacting with PTEN. The miR-30a-5p mimic decreased the expression of apoptosis-related proteins and the levels of the proinflammatory markers IL-1ß, IL-6, and TNF-α by activating the PTEN/PI3K/Akt signaling pathway. Conversely, anti-miR-30a-5p treatment attenuated these effects. Additionally, silencing PTEN and anti-miR-30a-5p had opposite effects on H/R-induced cell apoptosis. CONCLUSIONS: miR-30a-5p plays a crucial role in cardiomyocyte apoptosis after hypoxia-induced acute myocardial infarction. Our findings provide translational evidence that miR-30a-5p is a novel potential therapeutic target for AMI.

Syndecan-4 is required for early-stage repair responses during zebrafish heart regeneration.

BACKGROUND: The healing process after a myocardial infarction (MI) in humans involves complex events that replace damaged tissue with a fibrotic scar. The affected cardiac tissue may lose its function permanently. In contrast, zebrafish display a remarkable capacity for scar-free heart regeneration. Previous studies have revealed that syndecan-4 (SDC4) regulates inflammatory response and fibroblast activity following cardiac injury in higher vertebrates. However, whether and how Sdc4 regulates heart regeneration in highly regenerative zebrafish remains unknown. METHODS AND RESULTS: This study showed that sdc4 expression was differentially regulated during zebrafish heart regeneration by transcriptional analysis. Specifically, sdc4 expression increased rapidly and transiently in the early regeneration phase upon ventricular cryoinjury. Moreover, the knockdown of sdc4 led to a significant reduction in extracellular matrix protein deposition, immune cell accumulation, and cell proliferation at the lesion site. The expression of tgfb1a and col1a1a, as well as the protein expression of Fibronectin, were all down-regulated under sdc4 knockdown. In addition, we verified that sdc4 expression was required for cardiac repair in zebrafish via in vivo electrocardiogram analysis. Loss of sdc4 expression caused an apparent pathological Q wave and ST elevation, which are signs of human MI patients. CONCLUSIONS: Our findings support that Sdc4 is required to mediate pleiotropic repair responses in the early stage of zebrafish heart regeneration.

Transcriptome analysis of cardiac endothelial cells after myocardial infarction reveals temporal changes and long-term deficits.

Endothelial cells (ECs) have essential roles in cardiac tissue repair after myocardial infarction (MI). To establish stage-specific and long-term effects of the ischemic injury on cardiac ECs, we analyzed their transcriptome at landmark time points after MI in mice. We found that early EC response at Day 2 post-MI centered on metabolic changes, acquisition of proinflammatory phenotypes, initiation of the S phase of cell cycle, and activation of stress-response pathways, followed by progression to mitosis (M/G2 phase) and acquisition of proangiogenic and mesenchymal properties during scar formation at Day 7. In contrast, genes involved in vascular physiology and maintenance of vascular tone were suppressed. Importantly, ECs did not return to pre-injury phenotypes after repair has been completed but maintained inflammatory, fibrotic and thrombotic characteristics and lost circadian rhythmicity. We discovered that the highest induced transcript is the mammalian-specific Sh2d5 gene that promoted migration and invasion of ECs through Rac1 GTPase. Our results revealed a synchronized, temporal activation of disease phenotypes, metabolic pathways, and proliferation in quiescent ECs after MI, indicating that precisely-timed interventions are necessary to optimize cardiac tissue repair and improve outcomes. Furthermore, long-term effects of acute ischemic injury on ECs may contribute to vascular dysfunction and development of heart failure.

Ticagrelor downregulates the expression of proatherogenic and proinflammatory miR125-b compared to clopidogrel: A randomized, controlled trial.

BACKGROUND: Platelet P2Y12 antagonist ticagrelor reduces cardiovascular mortality after acute myocardial infarction (AMI) compared to clopidogrel, but the underlying mechanism is unknown. Because activated platelets release proatherogenic and proinflammatory microRNAs, including miR-125a, miR-125b and miR-223, we hypothesized that the expression of these miRNAs is lower on ticagrelor, compared to clopidogrel. OBJECTIVES: We compared miR-125a, miR-125b and miR-223 expression in plasma of patients after AMI treated with ticagrelor or clopidogrel. METHODS: After percutaneous coronary intervention on acetylsalicylic acid and clopidogrel, 60 patients with first AMI were randomized to switch to ticagrelor or to continue with clopidogrel. Plasma expression of miR-223, miR-125a-5p, miR-125b was measured using quantitative polymerase chain reaction at baseline and after 72 h and 6 months of treatment with ticagrelor or clopidogrel in patients and one in 30 healthy volunteers. Multiple electrode aggregometry using ADP test was used to determine platelet reactivity in response to P2Y12 inhibitors. RESULTS: Expression of miR-125b was higher in patients with AMI 72 h and 6 months, compared to healthy volunteers (p = 0.001), whereas expression of miR-125a-5p and miR-223 were comparable. In patients randomized to ticagrelor, expression of miR-125b decreased at 72 h (p = 0.007) and increased back to baseline at 6 months (p = 0.005). Expression of miR-125a-5p and miR-223 was not affected by the switch from clopidogrel to ticagrelor. CONCLUSIONS: Ticagrelor treatment leads to lower plasma expression of miR-125b after AMI, compared to clopidogrel. Higher expression of miR-125b might explain recurrent thrombotic events and worse clinical outcomes in patients treated with clopidogrel, compared to ticagrelor.

E-selectin is associated with stable angina and myocardial infarction in a sample of Kurdish population.

Endothelial dysfunction is the main factor that causes the onset of CAD. Leukocyte adhesion to the endothelium of the active blood artery wall has been demonstrated to be one of the early indicators of arteriosclerosis. This process is regulated by selectins. The purpose of this study is to ascertain the relationship between the polymorphisms in the E-selectin gene that have been linked to ischemic heart disease. We looked at the functional impact of the E-selectin gene polymorphism 7170G>C in Iraqi patients with IHD. This study was conducted on 200 participants who were admitted to the surgical specialty hospital-cardiac center in Erbil City, Iraq between October 2021 and May 2022. Based on the outcomes of the clinical examination, laboratory tests, coronary angiography (COA), acute myocardial infarction (MI) type ST-elevation myocardial infarction (STEMI), stable angina pectoris (SAP), and healthy control groups were tested. Each sample was subjected to Sanger sequencing. The polymorphism was significantly linked to stable angina and myocardial infarction Genotype CC was higher in SAP when compared with MI and control groups which was statistically significant with (p-value<0.05). A higher proportion of C allele was observed in SAP patients (15.7%) which was significantly higher than MI (14.58%) and control (10.8%). The statistical chi-square analysis for allele G frequency showed insignificant differences (p-value>0.05) between patients and the control group. Genetic variation in E-selectin such as polymorphism in nucleotide 7170 G>C at exon 4 region can significantly affect the outcome of cardiovascular diseases.

Effect of AGTR1 A1166C genetic polymorphism on coronary artery lesions and mortality in patients with acute myocardial infarction.

The pathogenesis and prognosis of patients with acute myocardial infarction (AMI) may be influenced by both genetic and environmental factors. Findings on the relationship of polymorphisms in various genes encoding the renin-angiotensin-aldosterone system with coronary artery lesions and mortality in AMI patients are inconsistent. The aim of this study was to determine whether the AGTR1 A1166C genetic polymorphism affects coronary artery lesions and 1-year mortality in post-AMI patients. Patients with their first AMI admitted to Cho Ray Hospital, Vietnam, from January 2020 to August 2021 were enrolled in this prospective clinical study. All participants underwent invasive coronary angiography and were identified as having the genotypes of AGTR1 A1166C by way of a polymerase chain reaction method. All patients were followed up for all-cause mortality 12 months after AMI. The association of the AGTR1 A1166C polymorphism with coronary artery lesions and 1-year mortality was evaluated using logistic regression and Cox regression analysis, respectively. Five hundred and thirty-one AMI patients were recruited. The mean age was 63.9 ± 11.6 years, and 71.6% of the patients were male. There were no significant differences in the location and number of diseased coronary artery branches between the AA and AC+CC genotypes. The AC and CC genotypes were independently associated with ≥ 90% diameter stenosis of the left anterior descending (LAD) artery (odds ratio = 1.940; 95% confidence interval (CI): 1.059-3.552, p = 0.032). The 1-year all-cause mortality rate difference between patients with the AC and CC genotypes versus those with the AA genotype was not statistically significant (hazard ratio = 1.000, 95% CI: 0.429-2.328, p = 1.000). The AGTR1 A1166C genetic polymorphism is associated with very severe luminal stenosis of the LAD but not with mortality in AMI patients.

FBXL8 inhibits post-myocardial infarction cardiac fibrosis by targeting Snail1 for ubiquitin-proteasome degradation.

Abnormal cardiac fibrosis is the main pathological change of post-myocardial infarction (MI) heart failure. Although the E3 ubiquitin ligase FBXL8 is a key regulator in the cell cycle, cell proliferation, and inflammation, its role in post-MI ventricular fibrosis and heart failure remains unknown. FBXL8 was primarily expressed in cardiac fibroblasts (CFs) and remarkably decreased in CFs treated by TGFß and heart subjected to MI. The echocardiography and histology data suggested that adeno-associated viruses (AAV9)-mediated FBXL8 overexpression had improved cardiac function and ameliorated post-MI cardiac fibrosis. In vitro, FBXL8 overexpression prevented TGFß-induced proliferation, migration, contraction, and collagen secretion in CFs, while knockdown of FBXL8 demonstrated opposite effects. Mechanistically, FBXL8 interacted with Snail1 to promote Snail1 degradation through the ubiquitin-proteasome system and decreased the activation of RhoA. Moreover, the FBXL8ΔC3 binding domain was indispensable for Snail1 interaction and degradation. Ectopic Snail1 expression partly abolished the effects mediated by FBXL8 overexpression in CFs treated by TGFß. These results characterized the role of FBXL8 in regulating the ubiquitin-mediated degradation of Snail1 and revealed the underlying molecular mechanism of how MI up-regulated the myofibroblasts differentiation-inducer Snail1 and suggested that FBXL8 may be a potential curative target for improving post-MI cardiac function.

[Mechanism of Guizhi Gancao Decoction against myocardial ischemia-reperfusion injury based on network pharmacology and experimental verification].

This study employed network pharmacology to investigate the effect of Guizhi Gancao Decoction(GGD) on myocardial ischemia-reperfusion injury(MI/RI) in rats and decipher the underlying mechanism. Firstly, the chemical components and targets of GGD against MI/RI were searched against the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), SwissTargetPrediction, and available articles. STRING and Cytoscape 3.7.2 were used to establish the protein-protein interaction(PPI) network for the common targets, and then Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analyses were carried out for the core targets. The "drug-active component-target-pathway" network was built. Furthermore, molecular docking between key active components and targets was conducted in AutoDock Vina. Finally, the rat model of MI/RI was established, and the myocardial infarction area was measured. Hematoxylin-eosin(HE) staining and transmission electron microscopy(TEM) were employed to detect cardiomyocyte pathology and ultrastructural changes. Western blot was employed to determine the expression of related proteins in the myocardial tissue. A total of 75 chemical components of GGD were screened out, corresponding to 318 targets. The PPI network revealed 46 core targets such as tumor protein p53(TP53), serine/threonine kinase 1(AKT1), signal transducer and activator of transcription 3(STAT3), non-receptor tyrosine kinase(SRC), mitogen-activated protein kinase 1(MAPK1), MAPK3, and tumor necrosis factor(TNF). According to GO and KEGG enrichment analyses, the core targets mainly affected the cell proliferation and migration, signal transduction, apoptosis, and transcription, involving advanced glycation end products-receptor(AGE-RAGE), MAPK and other signaling pathways in cancers and diabetes complications. The molecular docking results showed that the core components of GGD, such as licochalcone A,(+)-catechin, and cinnamaldehyde, had strong binding activities with the core target proteins, such as MAPK1 and MAPK3. The results of animal experiments showed that compared with the model group, GGD significantly increase superoxide dismutase, decreased malondialdehyde, lactate dehydrogenase, and creatine kinase-MB, and reduced the area of myocardial infarction. HE staining and TEM results showed that GGD pretreatment restored the structure of cardiomyocytes and alleviated the pathological changes and ultrastructural damage of mitochondria in the model group. In addition, GGD significantly down-regulated the phosphorylation of c-Jun N-terminal kinase and p38 and up-regulate that of extracellular regulated kinases 1/2 in the myocardial tissue. The results suggested that GGD may exert the anti-MI/RI effect by regulating the MAPK signaling pathway via the synergistic effects of Cinnamomi Ramulus and Glycyrrhizae Radix et Rhizoma.

Engineered Exosomes with Growth Differentiation Factor-15 Overexpression Enhance Cardiac Repair After Myocardial Injury.

Background: Cardiac repair remains a thorny issue for survivors of acute myocardial infarction (AMI), due to the regenerative inertia of myocardial cells. Cell-free therapies, such as exosome transplantation, have become a potential strategy for myocardial injury. The aim of this study was to investigate the role of engineered exosomes in overexpressing Growth Differentiation Factor-15 (GDF-15) (GDF15-EVs) after myocardial injury, and their molecular mechanisms in cardiac repair. Methods: H9C2 cells were transfected with GDF-15 lentivirus or negative control. The exosomes secreted from H9C2 cells were collected and identified. The cellular apoptosis and autophagy of H2O2-injured H9C2 cells were assessed by Western blotting, TUNEL assay, electron microscopy, CCK-8 and caspase 3/7 assay. A rat model of AMI was constructed by ligating the left anterior descending artery. The anti-apoptotic, pro-angiogenic effects of GDF15-EVs treatment, as well as ensuing functional and histological recovery were evaluated. Then, mRNA sequencing was performed to identify the differentially expressed mRNAs after GDF15-EVs treatment. Results: GDF15-EVs inhibited apoptosis and promoted autophagy in H2O2 injured H9C2 cells. GDF15-EVs effectively decreased the infarct area and enhanced the cardiac function in rats with AMI. Moreover, GDF15-EVs hindered inflammatory cell infiltration, inhibited cell apoptosis, and promoted cardiac angiogenesis in rats with AMI. RNA sequence showed that telomerase reverse transcriptase (TERT) mRNA was upregulated in GDF15-EVs-treated H9C2 cells. AMPK signaling was activated after GDF15-EVs. Silencing TERT impaired the protective effects of GDF15-EVs on H2O2-injured H9C2 cells. Conclusion: GDF15-EVs could fulfil their protective effects against myocardial injury by upregulating the expression of TERT and activating the AMPK signaling pathway. GDF15-EVs might be exploited to design new therapies for AMI.

A division-of-labor mode contributes to the cardioprotective potential of mesenchymal stem/stromal cells in heart failure post myocardial infarction.

Background: Treatment of heart failure post myocardial infarction (post-MI HF) with mesenchymal stem/stromal cells (MSCs) holds great promise. Nevertheless, 2-dimensional (2D) GMP-grade MSCs from different labs and donor sources have different therapeutic efficacy and still in a low yield. Therefore, it is crucial to increase the production and find novel ways to assess the therapeutic efficacy of MSCs. Materials and methods: hUC-MSCs were cultured in 3-dimensional (3D) expansion system for obtaining enough cells for clinical use, named as 3D MSCs. A post-MI HF mouse model was employed to conduct in vivo and in vitro experiments. Single-cell and bulk RNA-seq analyses were performed on 3D MSCs. A total of 125 combination algorithms were leveraged to screen for core ligand genes. Shinyapp and shinycell workflows were used for deploying web-server. Result: 3D GMP-grade MSCs can significantly and stably reduce the extent of post-MI HF. To understand the stable potential cardioprotective mechanism, scRNA-seq revealed the heterogeneity and division-of-labor mode of 3D MSCs at the cellular level. Specifically, scissor phenotypic analysis identified a reported wound-healing CD142+ MSCs subpopulation that is also associated with cardiac protection ability and CD142- MSCs that is in proliferative state, contributing to the cardioprotective function and self-renewal, respectively. Differential expression analysis was conducted on CD142+ MSCs and CD142- MSCs and the differentially expressed ligand-related model was achieved by employing 125 combination algorithms. The present study developed a machine learning predictive model based on 13 ligands. Further analysis using CellChat demonstrated that CD142+ MSCs have a stronger secretion capacity compared to CD142- MSCs and Flow cytometry sorting of the CD142+ MSCs and qRT-PCR validation confirmed the significant upregulation of these 13 ligand factors in CD142+ MSCs. Conclusion: Clinical GMP-grade 3D MSCs could serve as a stable cardioprotective cell product. Using scissor analysis on scRNA-seq data, we have clarified the potential functional and proliferative subpopulation, which cooperatively contributed to self-renewal and functional maintenance for 3D MSCs, named as "division of labor" mode of MSCs. Moreover, a ligand model was robustly developed for predicting the secretory efficacy of MSCs. A user-friendly web-server and a predictive model were constructed and available (https://wangxc.shinyapps.io/3D_MSCs/).

[Chaihu Sanshen Capsules protect rats from myocardial ischemia reperfusion injury via PKCßâ ¡/NOX2/ROS signaling pathway].

This study aims to explore the pathogenesis of myocardial ischaemia reperfusion injury(MIRI) based on oxidative stress-mediated programmed cell death and the mechanism and targets of Chaihu Sanshen Capsules in treating MIRI via the protein kinase Cß(PKCßⅡ)/NADPH oxidase 2(NOX2)/reactive oxygen species(ROS) signaling pathway. The rat model of MIRI was established by the ligation of the left anterior descending branch. Rats were randomized into 6 groups: sham group, model group, clinically equivalent-, high-dose Chaihu Sanshen Capsules groups, N-acetylcysteine group, and CGP53353 group. After drug administration for 7 consecutive days, the area of myocardial infarction in each group was measured. The pathological morphology of the myocardial tissue was observed by hematoxylin-eosin(HE) staining. The apoptosis in the myocardial tissue was observed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL). Enzyme-linked immunosorbent assay(ELISA) was employed to measure the le-vels of indicators of myocardial injury and oxidative stress. The level of ROS was detected by flow cytometry. The protein and mRNA levels of the related proteins in the myocardial tissue were determined by Western blot and real-time quantitative PCR(RT-qPCR), respectively. Compared with the sham group, the model group showed obvious myocardial infarction, myocardial structural disorders, interstitial edema and hemorrhage, presence of a large number of vacuoles, elevated levels of myocardial injury markers, myocardial apoptosis, ROS, and malondialdehyde(MDA), lowered superoxide dismutase(SOD) level, and up-regulated protein and mRNA le-vels of PKCßⅡ, NOX2, cysteinyl aspartate specific proteinase-3(caspase-3), and acyl-CoA synthetase long-chain family member 4(ACSL4) in the myocardial tissue. Compared with the model group, Chaihu Sanshen Capsules reduced the area of myocardial infarction, alleviated the pathological changes in the myocardial tissue, lowered the levels of myocardial injury and oxidative stress indicators and apoptosis, and down-regulated the mRNA and protein levels of PKCßⅡ, NOX2, caspase-3, and ACSL4 in the myocardial tissue. Chaihu Sanshen Capsules can inhibit oxidative stress and programmed cell death(apoptosis, ferroptosis) by regulating the PKCßⅡ/NOX2/ROS signaling pathway, thus mitigating myocardial ischemia reperfusion injury.

Characterization of the m6A regulators' landscape highlights the clinical significance of acute myocardial infarction.

Objective: Acute myocardial infarction (AMI) is a severe cardiovascular disease that threatens human life and health globally. N6-methyladenosine (m6A) governs the fate of RNAs via m6A regulators. Nevertheless, how m6A regulators affect AMI remains to be deciphered. To solve this issue, an integrative analysis of m6A regulators in AMI was conducted. Methods: We acquired transcriptome profiles (GSE59867, GSE48060) of peripheral blood samples from AMI patients and healthy controls. Key m6A regulators were used for LASSO, and consensus clustering was conducted. Next, the m6A score was also computed. Immune cell infiltration, ferroptosis, and oxidative stress were evaluated. In-vitro and in-vivo experiments were conducted to verify the role of the m6A regulator ALKBH5 in AMI. Results: Most m6A regulators presented notable expression alterations in circulating cells of AMI patients versus those of controls. Based on key m6A regulators, we established a gene signature and a nomogram for AMI diagnosis and risk prediction. AMI patients were classified into three m6A clusters or gene clusters, respectively, and each cluster possessed the unique properties of m6A modification, immune cell infiltration, ferroptosis, and oxidative stress. Finally, the m6A score was utilized to quantify m6A modification patterns. Therapeutic targeting of ALKBH5 greatly alleviated apoptosis and intracellular ROS in H/R-induced H9C2 cells and NRCMs. Conclusion: Altogether, our findings highlight the clinical significance of m6A regulators in the diagnosis and risk prediction of AMI and indicate the critical roles of m6A modification in the regulation of immune cell infiltration, ferroptosis, and oxidative stress.

Exosomal CircRNAs in Circulation Serve as Diagnostic Biomarkers for Acute Myocardial Infarction.

BACKGROUND: The diagnostic potential of circular RNAs (circRNAs) in circulating exosomes for acute myocardial infarction (AMI) is not well understood, despite existing research indicating their role in cardiovascular diseases. This study aimed to clarify the significance of exosomal circular RNAs as indicators for AMI. METHODS: We examined 120 individuals diagnosed with AMI and 83 individuals with non-cardiogenic chest pain (NCCP), all previously enrolled in a conducted study. High-throughput sequencing to identify differentially expressed circRNAs in the circulating exosomes of AMI patients. To validate, we employed Real-Time polymerase chain reaction (RT-PCR) targeting five circRNAs that exhibited notable increase. RESULTS: The sequencing identified 893 exosomal circRNAs with altered expression in AMI patients, including 118 up-regulated and 775 down-regulated circRNAs. Genes linked to these circRNAs were enriched in crucial Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, highlighting their direct relevance to AMI pathophysiology. Three exosomal circRNAs (hsa_circ_0001558, hsa_circ_0001535, and hsa_circ_0000972) showed significant up-regulation in AMI patients during the initial validation cohort. The corresponding area under the curve (AUC) values were 0.79, 0.685, and 0.683, respectively. Further validation of hsa_circ_0001558 in a second cohort showed a 4.45-fold increase in AMI patients, with AUC = 0.793. The rise was particularly noticeable in patients with non-ST-elevation myocardial infarction (NSTEMI) (2.80 times, AUC = 0.72) and patients with ST-elevation myocardial infarction (STEMI) (5.27 times, AUC = 0.831) compared to patients with NCCP. CONCLUSIONS: Our findings demonstrate significant differences in the expression patterns of circRNAs in plasma exosomes between AMI patients and NCCP patients. Specifically, hsa_circ_0001558 appears as a promising indicator for AMI diagnosis. Further research is necessary to fully evaluate the diagnostic potential of exosomal circRNAs in the context of AMI, emphasizing the importance of these findings.

Detecting early-warning biomarkers associated with heart-exosome genetic-signature for acute myocardial infarction: A source-tracking study of exosome.

The genetic information of plasma total-exosomes originating from tissues have already proven useful to assess the severity of coronary artery diseases (CAD). However, plasma total-exosomes include multiple sub-populations secreted by various tissues. Only analysing the genetic information of plasma total-exosomes is perturbed by exosomes derived from other organs except the heart. We aim to detect early-warning biomarkers associated with heart-exosome genetic-signatures for acute myocardial infarction (AMI) by a source-tracking analysis of plasma exosome. The source-tracking of AMI plasma total-exosomes was implemented by deconvolution algorithm. The final early-warning biomarkers associated with heart-exosome genetic-signatures for AMI was identified by integration with single-cell sequencing, weighted gene correction network and machine learning analyses. The correlation between biomarkers and clinical indicators was validated in impatient cohort. A nomogram was generated using early-warning biomarkers for predicting the CAD progression. The molecular subtypes landscape of AMI was detected by consensus clustering. A higher fraction of exosomes derived from spleen and blood cells was revealed in plasma exosomes, while a lower fraction of heart-exosomes was detected. The gene ontology revealed that heart-exosomes genetic-signatures was associated with the heart development, cardiac function and cardiac response to stress. We ultimately identified three genes associated with heart-exosomes defining early-warning biomarkers for AMI. The early-warning biomarkers mediated molecular clusters presented heterogeneous metabolism preference in AMI. Our study introduced three early-warning biomarkers associated with heart-exosome genetic-signatures, which reflected the genetic information of heart-exosomes carrying AMI signals and provided new insights for exosomes research in CAD progression and prevention.

Association of different milk fat content with coronary artery disease and myocardial infarction risk: A Mendelian randomization study.

BACKGROUND: Numerous observational studies have investigated on the correlation of whole, semi-skimmed, and skimmed milk with coronary artery disease (CAD) and myocardial infarction (MI) risk; However, no consensus has been reached and evidence on any causal links between these exposures and outcomes remains unclear. This study aimed to conduct univariate and multivariate Mendelian randomization (MR) analyses, using publicly released genome-wide association study summary statistics (GWAS) from the IEU GWAS database, to ascertain the causal association of milk with various fat content with CAD and MI risk. METHODS: For the exposure data, 29, 15, and 30 single-nucleotide polymorphisms for whole milk, semi-skimmed milk, and skimmed milk, respectively, obtained from 360,806 Europeans, were used as instrumental variables. CAD and MI comprised 141,217 and 395,795 samples, respectively. We used inverse variance weighted (IVW), weighted median, MR-Egger regression, and MR Pleiotropy Residual Sum and Outlier analyses to determine whether pleiotropy and heterogeneity could skew the MR results. Sensitivity tests were conducted to verify the robustness of the results. RESULTS: After adjusting for false discovery rates (FDR), we discovered proof that skimmed milk intake is a genetically predicted risk factor for CAD (odds ratio [OR] = 5.302; 95% confidence interval [CI] 2.261-12.432; P < 0.001; FDR-corrected P < 0.001) and MI (OR = 2.287; 95% CI 1.218-4.300; P = 0.010; FDR-corrected P = 0.009). Most sensitivity assessments yielded valid results. Multivariable MR for CAD and MI produced results consistent with those obtained using the IVW method. There was no causal relationship between whole or semi-skimmed milk, and CAD or MI. CONCLUSION: Our findings indicate that the consumption of skimmed milk may increase the risk of CAD and MI. This evidence may help inform dietary recommendations for preventing cardiovascular disease. Further studies are required to elucidate the underlying mechanisms.

Serum ferritin and the risk of myocardial infarction: A Mendelian randomization study.

The potential role of serum ferritin as a risk factor for myocardial infarction (MI) is controversial, necessitating a systematic exploration of the causal relationship between ferritin and MI through Mendelian randomization (MR) methods. Genetic data were derived from a genome-wide association study (GWAS), employing the inverse variance-weighted (IVW) method as the primary approach. Comprehensive sensitivity analyses were conducted to validate the robustness of the results. Evaluation of instrumental variables was performed using the F-statistic, and a meta-analysis was employed to assess the average gene-predicted effect between ferritin and MI. The MR study revealed a negative correlation between ferritin and MI. The odds ratios (ORs) in the IVW method were 0.83 [95% confidence interval (CI) = 0.72-0.97; P = .017] and 0.86 (95% CI = 0.72-1.02; P = .080). Additionally, meta-analysis consistently indicated a negative causal relationship between ferritin and MI, with no heterogeneity or horizontal pleiotropy, thereby indicating a negative correlation between ferritin levels and the risk of MI. The genetic evidence sheds light on the causal relationship between ferritin levels and MI risk, providing new perspectives for future interventions in acute myocardial infarction (AMI).

​Comprehensive mendelian randomization analysis of plasma proteomics to identify new therapeutic targets for the treatment of coronary heart disease and myocardial infarction.

BACKGROUND: Ischemic heart disease is one of the leading causes of mortality worldwide, and thus calls for development of more effective therapeutic strategies. This study aimed to identify potential therapeutic targets for coronary heart disease (CHD) and myocardial infarction (MI) by investigating the causal relationship between plasma proteins and these conditions. METHODS: A two-sample Mendelian randomization (MR) study was performed to evaluate more than 1600 plasma proteins for their causal associations with CHD and MI. The MR findings were further confirmed through Bayesian colocalization, Summary-data-based Mendelian Randomization (SMR), and Transcriptome-Wide Association Studies (TWAS) analyses. Further analyses, including enrichment analysis, single-cell analysis, MR analysis of cardiovascular risk factors, phenome-wide Mendelian Randomization (Phe-MR), and protein-protein interaction (PPI) network construction were conducted to verify the roles of selected causal proteins. RESULTS: Thirteen proteins were causally associated with CHD, seven of which were also causal for MI. Among them, FES and PCSK9 were causal proteins for both diseases as determined by several analytical methods. PCSK9 was a risk factor of CHD (OR = 1.25, 95% CI: 1.13-1.38, P = 7.47E-06) and MI (OR = 1.36, 95% CI: 1.21-1.54, P = 2.30E-07), whereas FES was protective against CHD (OR = 0.68, 95% CI: 0.59-0.79, P = 6.40E-07) and MI (OR = 0.65, 95% CI: 0.54-0.77, P = 5.38E-07). Further validation through enrichment and single-cell analysis confirmed the causal effects of these proteins. Moreover, MR analysis of cardiovascular risk factors, Phe-MR, and PPI network provided insights into the potential drug development based on the proteins. CONCLUSIONS: This study investigated the causal pathways associated with CHD and MI, highlighting the protective and risk roles of FES and PCSK9, respectively. FES. Specifically, the results showed that these proteins are promising therapeutic targets for future drug development.