Use of Machine Learning for the Identification and Validation of Immunogenic Cell Death Biomarkers and Immunophenotypes in Coronary Artery Disease.

Objective: Immunogenic cell death (ICD) is part of the immune system's response to coronary artery disease (CAD). In this study, we bioinformatically evaluated the diagnostic and therapeutic utility of immunogenic cell death-related genes (IRGs) and their relationship with immune infiltration features in CAD. Methods: We acquired the CAD-related datasets GSE12288, GSE71226, and GSE120521 from the Gene Expression Omnibus (GEO) database and the IRGs from the GeneCards database. After identifying the immune cell death-related differentially expressed genes (IRDEGs), we developed a risk model and detected immune subtypes in CAD. IRDEGs were identified using least absolute shrinkage and selection operator (LASSO) analysis. Using a nomogram, we confirmed that both the LASSO model and ICD signature genes had good diagnostic performance. Results: There was a high degree of coincidence and immune representativeness between two CAD groups based on characteristic genes and hub genes. Hub genes were associated with the interaction of neuroactive ligands with receptors and cell adhesion receptors. The two groups differed in terms of adipogenesis, allograft rejection, and apoptosis, as well as the ICD signature and hub gene expression levels. The two CAD-ICD subtypes differed in terms of immune infiltration. Conclusion: Quantitative real-time PCR (qRT-PCR) correlated CAD with the expression of OAS3, ITGAV, and PIBF1. The ICD signature genes are candidate biomarkers and reference standards for immune grouping in CAD and can be beneficial in precise immune-targeted therapy.

HINT2 deficiency deteriorates oxidative stress in a mouse model of myocardial infarction.

AIMS: Myocardial infarction (MI) is one of the serious diseases with great mortality over the world. Myocardial mitochondrial oxidative stress has been implicated as a key player in MI. The histidine triad nucleotide-binding protein 2 (HINT2) is a nucleotide hydrolase and transferase located in mitochondria. HINT2 has multiple functions such as regulating mitochondrial lipid metabolism and respiration and glucose homeostasis. Although HINT2 has been shown to protect against MI, the underlying mechanisms were not fully elucidated. In this study, the effects of HINT2 on oxidative stress during MI were explored. METHODS AND RESULTS: MI mouse models in both wild-type and HINT2-deficient mice were established. The expression of HINT2 in HINT2-deficient mice was determined by quantitative real-time PCR and western blot. The levels of oxidative stress were measured, including the levels of malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), and glutathione (GSH). The myocardial functions, as indicated by left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular ejection fraction (LVEF), and left ventricular fractional shortening (LVFS), were monitored. Both mRNA and protein expressions of HINT2 in the myocardial tissues were significantly down-regulated in MI mice starting at 6 h post-MI. MI induced oxidative stress 6 h post-MI in myocardial tissues of wild-type mice, as suggested by the enhanced MDA and NO levels and decreased SOD and GSH levels. The expression of HINT2 was negatively correlated to the MDA and NO levels and positively correlated to the SOD and GSH levels. HINT2-deficient MI mice had significantly elevated levels of MDA and NO and significantly decreased levels of SOD and GSH when compared with wild-type MI mice. HINT2-deficient MI mice had higher LVEDD and LVESD and lower LVEF and LVFS compared with wild-type MI mice, indicating that HINT2 deficiency exacerbated myocardial dysfunction. CONCLUSIONS: HINT2 deficiency causes deteriorative oxidative stress in MI mice, leading to exacerbated myocardial dysfunction.

Deep Learning-Based Medical Data Association Rules to Explore the Connectivity and Regulation Mechanism of miRNA-mRNA Network in Myocarditis.

Acute, chronic myocarditis as myocardial localized or diffuse inflammation lesions is usually involving cardiac function in patients with severe adverse outcomes such as heart failure, sudden death, and no unified, but its pathogenesis clinical is mainly composed of a number of factors including infection and autoimmune defects, such as physical and chemical factors; therefore, it is of great significance to explore the regulation mechanism of myocarditis-related miRNA network connectivity and temperament for in-depth understanding of the pathogenesis of myocarditis and the direction of targeted therapy. Based on this, this study explored the miRNA network related to the pathogenesis of myocarditis through deep learning medical data association rules and analyzed its specific mechanism. The results showed that 39 upregulated miRNAs, 88 downregulated miRNAs, 109 upregulated differentially expressed miRNAs, and 589 downregulated mRNAs were obtained by data association through GSE126677 and GSE4172 databases. GO enrichment and KRGG enrichment analysis showed that the differentially expressed mRNAs were involved in the regulation of a variety of biological processes, cellular components, and molecular functions. At the same time, the miRNA with differentially expressed miRNAs and their corresponding mRNAs were connected to further clarify the specific molecular mechanism of the pathological changes of myocarditis by constructing miRNA-mRNA network. It provides effective potential molecular targets for subsequent treatment and diagnosis.

miR-320 accelerates chronic heart failure with cardiac fibrosis through activation of the IL6/STAT3 axis.

Cardiac fibrosis could induce abnormal cardiac function and become a novel target for cardiac hypertrophy and chronic heart failure. MiRNA-320 is a crucial miRNA in cardiovascular disease, but it is poorly understood whether it plays a role in cardiac fibrosis pathogenesis. We aimed to identify the specific underlying mechanism of miR-320 in cardiac fibrosis and hypertrophic pathogenesis. In our study, the GEO datasets revealed that STAT3 was significantly highly expressed in cardiomyocyte lines. MiR-320 activation and STAT3 signaling pathways were statistically significantly connected. Furthermore, miR-320 was highly associated with cardiac fibrosis and hypertrophic disease. Interstitial fibrosis was observed in the mice subjected to TAC surgery, markedly enhanced in miR-320 mimics. Mechanistically, we revealed that miR-320 mimics aggravated the pressure overload and induced cardiac hypertrophy and fibrosis via the IL6/STAT3/PTEN axis. MiR-320 mimics accelerated cardiac hypertrophy and cardiac fibrosis via the IL6/STAT3/PTEN axis. These results suggest that targeting miR-320 may represent a potential therapeutic strategy for cardiac hypertrophy and fibrosis.

A case of hypokalemia-induced bidirectional ventricular tachycardia.

BACKGROUND: Bidirectional ventricular tachycardia (BVT) is a rare, but serious, arrhythmia. Hypokalemia is commonly found in clinical practice, but hypokalemia-induced BVT has rarely been reported. CASE PRESENTATION: A 74-year-old male patient with the symptoms of chest distress and palpitations was admitted owing to frequent discharge of his implantable cardioverter defibrillator (ICD) for 4 days. Before admission, the patient experienced diarrhea after intake of crabs, and felt frequent discharge of his ICD with a total of approximately 17 discharges in 4 days. He had no history of digitalis use. The serum potassium level after admission was 3.1 mmol/L and an electrocardiogram was consistent with BVT. The diagnosis was ventricular tachycardia, electrical storm, and hypokalemia. His ventricular tachycardia was completely relieved after correction of hypokalemia. CONCLUSIONS: After correction of hypokalemia in this patient, the episode of BVT was terminated and no recurrence of BVT was observed during long-term follow-up. Our findings suggest the diagnosis of hypokalemia-induced BVT.

Recombinant Brain Natriuretic Peptide for the Prevention of Contrast-Induced Nephropathy in Patients with Chronic Kidney Disease Undergoing Nonemergent Percutaneous Coronary Intervention or Coronary Angiography: A Randomized Controlled Trial.

The role of brain natriuretic peptide (BNP) in the prevention of contrast-induced nephropathy (CIN) is unknown. This study aimed to investigate BNP's effect on CIN in chronic kidney disease (CKD) patients undergoing elective percutaneous coronary intervention (PCI) or coronary angiography (CAG). The patients were randomized to BNP (0.005 µg/kg/min before contrast media (CM) exposure and saline hydration, n = 106) or saline hydration alone (n = 103). Cystatin C, serum creatinine (SCr) levels, and estimated glomerular filtration rates (eGFR) were assessed at several time points. The primary endpoint was CIN incidence; secondary endpoint included changes in cystatin C, SCr, and eGFR. CIN incidence was significantly lower in the BNP group compared to controls (6.6% versus 16.5%, P = 0.025). In addition, a more significant deterioration of eGFR, cystatin C, and SCr from 48 h to 1 week (P < 0.05) was observed in controls compared to the BNP group. Although eGFR gradually deteriorated in both groups, a faster recovery was achieved in the BNP group. Multivariate logistic regression revealed that using >100 mL of CM (odds ratio: 4.36, P = 0.004) and BNP administration (odds ratio: 0.21, P = 0.006) were independently associated with CIN. Combined with hydration, exogenous BNP administration before CM effectively decreases CIN incidence in CKD patients.

Brain natriuretic peptide for prevention of contrast-induced nephropathy after percutaneous coronary intervention or coronary angiography.

BACKGROUND: Many methods reportedly prevent contrast-induced nephropathy (CIN), but the effect of brain natriuretic peptide (BNP) on CIN is unknown. In this study we investigated recombinant BNP use before coronary angiography (CA) or nonemergent percutaneous coronary intervention (PCI) in patients with unstable angina. METHODS: One thousand patients with unstable angina were prospectively evaluated. The patients were randomly assigned to: group A, isotonic normal saline (NaCl 0.9%, 1 mL/kg/h) for 24 hours before CA or PCI; and group B, human recombinant BNP (rhBNP; 0.005 µg/kg/min). Serum creatinine (Scr) levels and estimated glomerular filtration rate were measured before and 24, 48, and 72 hours, and 7 days after the procedure. The primary outcome was CIN incidence defined according to a relative (≥ 25%) or absolute (≥ 0.5 mg/dL and 44 µmol/L, respectively) increase in Scr from baseline within 48 hours. The secondary end points were the changes in the Scr and estimated glomerular filtration rate, before and after the procedure. RESULTS: Contrast volume, a history of diabetes mellitus, and BNP administration independently predicted CIN. The incidence of CIN was significantly greater in group A than in group B (14.8% vs 5.6%; P < 0.01). Renal function was less compromised in patients who received rhBNP. The Scr of all patients with CIN remained increased for 24 hours, but it was lower and recovered faster in patients who received rhBNP. CONCLUSIONS: rhBNP administration before CA or PCI protects renal function and can significantly decrease CIN incidence.

Ginkgo biloba extract improves coronary artery circulation in patients with coronary artery disease: contribution of plasma nitric oxide and endothelin-1.

In patients with coronary artery disease (CAD), coronary blood flow is usually impaired due to imbalanced vasoactive substances such as nitric oxide (NO) and endothelin-1 (ET-1). The study was designed to test the effects of Ginkgo biloba extract (GBE) on the distal left anterior descending coronary artery (LAD) blood flow and plasma NO and ET-1 levels. Eighty CAD patients were randomly assigned to GBE (n = 42) and control (n = 38) groups. The LAD blood flow was assessed non-invasively using Doppler echocardiography at baseline and after 2 weeks. GBE treatment demonstrated a significant improvement in maximal diastolic peak velocity (MDPV), maximal systolic peak velocity (MSPV) and diastolic time velocity integral (DTVI) compared with controls (14.61 +/- 4.51% vs 0.67 +/- 2.66%, 9.03 +/- 4.81% vs 0.34 +/- 2.67% and 14.69 +/- 5.08% vs 0.68 +/- 3.00%, respectively, p < 0.01). NO was increased by 12.42% (p < 0.01), whereas ET-1 was decreased by 5.82% (p < 0.01). The NO/ET-1 ratio was increased by 19.47% (p < 0.01). A linear correlation was confirmed between the percentage change in LAD blood flow and in NO, ET-1 or NO/ET-1 ratio following GBE treatment. The results suggest that GBE treatment in CAD patients led to an increase of LAD blood flow, which might at least be related partly to the restoration of the delicate equilibrium between NO and ET-1.

Ginkgo biloba extract improves coronary blood flow in healthy elderly adults: role of endothelium-dependent vasodilation.

Advancing age decreases endothelial function; accordingly, it alters the physiological regulation of coronary blood flow. Ginkgo biloba extract (GBE) has well-documented anti-ageing effects. However, little is yet known about the pharmacological actions of GBE on endothelial dysfunction and coronary blood flow in healthy elderly adults. We designed the study to test the effects of GBE on distal left anterior descending coronary artery (LAD) blood flow and endothelium-dependent brachial artery flow-mediated dilation (FMD) in healthy elderly adults. Sixty healthy elderly adults were randomly assigned to either GBE or control groups. LAD blood flow and brachial artery FMD were measured non-invasively using high-resolution ultrasound before and after intravenous administration of GBE or saline. GBE significantly increased LAD blood flow in maximal diastolic peak velocity (MDPV), maximal systolic peak velocity (MSPV) and diastolic time velocity integral (DTVI) compared with the placebo group (19.16+/-13.91% vs. 0.30+/-2.55%, 17.76+/-14.56% vs. 0.53+/-2.32%, and 21.73+/-16.13% vs. 0.81+/-2.33%, MDPV, MSPV, and DTVI improvement from baseline, respectively, p<0.01). Brachial artery FMD was also increased by 56.03% (from 7.21+/-2.52% to 11.28+/-3.95%, p<0.01). A linear correlation was found between the percentage change in MDPV, MSPV, or DTVI of LAD blood flow and the percentage change in brachial artery FMD following treatment with GBE (r=0.538, 0.366, or 0.573, respectively, p<0.01, p<0.05, or p<0.01). Our data demonstrate that GBE treatment in healthy elderly adults leads to the increase of LAD blood flow in MDPV, MSPV and DTVI, and the increased response might relate to the improved endothelium-dependent vasodilatory capacity. This study implies an important future therapeutic strategy of using GBE to counteract the detrimental effects of ageing.

Changes of central retinal artery blood flow and endothelial function in patients with coronary artery disease.

PURPOSE: In patients with coronary artery disease (CAD), endothelial function is usually impaired, but the parameters of central retinal artery (CRA) blood flow have not yet been investigated. We designed the study to test the parameters of CRA blood flow and brachial artery flow-mediated dilation (FMD), accompanied by an aim of establishing whether a link may exist between the parameters of CRA blood flow and endothelial function. METHODS: Twenty-five subjects were diagnosed as CAD by coronary angiography, and 30 control subjects had normal coronary artery. CRA blood flow and brachial artery FMD were measured noninvasively using high-resolution ultrasound. RESULTS: In patients with CAD, peak systolic velocity (PSV), end diastolic velocity (EDV), and time velocity integral (TVI) of CRA blood flow were significantly lower (8.75 +/- 2.09 vs. 10.15 +/- 2.16 cm/s, 2.55 +/- 0.73 vs. 3.81 +/- 0.90 cm/s, 5.01 +/- 1.32 vs. 6.27 +/- 1.28 cm/s, respectively, p = 0.019, p < 0.01, p < 0.01), conversely, pulsatility index (PI) and resistance index (RI) were significantly higher (1.28 +/- 0.22 vs. 1.01 +/- 0.20, 0.71 +/- 0.06 vs. 0.62 +/- 0.07, respectively, p < 0.01) when compared with those in normal controls. Meanwhile, brachial artery FMD was decreased in CAD patients (3.91 +/- 1.65 vs. 8.78 +/- 2.92, p < 0.01). After controlling for age, gender, heart rate, and blood pressure, the PSV, EDV, TVI, PI or RI in CRA blood flow were associated with the brachial artery FMD (r = 0.182, 0.372, 0.245, -0.320, or -0.367, respectively, p = 0.205, p = 0.008, p = 0.087, p = 0.023, or p = 0.009). CONCLUSIONS: This study indicates that CRA blood flow is impaired in patients with CAD, and this may partly relate to endothelial dysfunction. Thus, endothelial function is likely to play an important role in the CRA microcirculation.

Ginkgo biloba extract improves coronary blood flow in patients with coronary artery disease: role of endothelium-dependent vasodilation.

Ginkgo biloba extract (GBE) has well-documented cardioprotective effects on coronary flow and positive effects on vasodilation through endothelium-derived nitric oxide in experimental animals, but these impacts in patients with coronary artery disease (CAD) have not yet been investigated. We designed this study to test the effects of GBE on distal left anterior descending coronary artery (LAD) blood flow and endothelium-dependent brachial artery flow-mediated dilation (FMD) in patients with CAD. Eighty CAD patients were randomly assigned to either GBE or saline (control) groups. LAD blood flow and brachial artery FMD were measured non-invasively using high-resolution ultrasound before and after intravenous administration of GBE or saline. GBE significantly increased LAD blood flow in maximal diastolic peak velocity (MDPV), maximal systolic peak velocity (MSPV) and diastolic time velocity integral (DTVI) compared with the control group (16.14 +/- 10.93 % vs. 0.28 +/- 2.14 %, 9.14 +/- 8.23 % vs. 0.79 +/- 2.56 %, and 15.23 +/- 7.28 % vs. 0.42 +/- 2.43 %, respectively, p < 0.01). Brachial artery FMD was also increased by 69.75 % (from 3.95 +/- 1.49 % to 6.55 +/- 2.51 %, p < 0.01). A linear correlation was found between the percentage changes in MDPV, MSPV, or DTVI of LAD blood flow and the percentage change in brachial artery FMD following treatment with GBE (r = 0.612, 0.486, or 0.521, respectively, p < 0.01). In summary, our data demonstrate that GBE treatment in CAD patients leads to an increase of LAD blood flow in MDPV, MSPV and DTVI, and the increase response might relate to the improved endothelium-dependent vasodilatory capacity. CAD: coronary artery disease DTVI: diastolic time velocity integral FMD: flow-mediated dilation GBE: GINKGO BILOBA extract LAD: distal left anterior descending coronary artery MDPV: maximal diastolic peak velocity MSPV: maximal systolic peak velocity NO: nitric oxide TTDE: transthoracic Doppler echocardiography.

The relation between His bundle and the first septal perforating artery: implications for percutaneous transluminal septal myocardial ablation.

The present study shows that in about 12.4% of subjects the first septal artery (FSA) is very near from the His bundle. Routine measurement of His-FSA distance during percutaneous transluminal septal myocardial ablation (PTSMA) procedure might be helpful to stratify which patient would be at higher risk of developing complete AV block.

Crosstalk between ERK1/2 and STAT3 in the modulation of cardiomyocyte hypertrophy induced by cardiotrophin-1.

BACKGROUND: The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway and the extracellular signal-regulated kinases 1/2 (ERK1/2) pathway are the two major independent signal transduction pathways. However, it has recently been found that STAT3 may be negatively regulated by ERK1/2 in gp130-dependent signaling. Cardiotrophin-1 (CT-1), a potent novel hypertrophic cytokine, depends on gp130 to induce signaling and depends on STAT3 to exert hypertrophic effect. In this study, we examined whether STAT3 activity was negatively regulated by ERK1/2 during CT-1-induced signaling in rat cardiomyocytes and, if so, whether such crosstalk interfered with the hypertrophic effect of CT-1 and, furthermore, whether the mechanism underlying the crosstalk involved phosphorylation of serine 727 (S727) in STAT3. METHODS: The activities of ERK1/2 and STAT3 were assessed by in-gel kinase assay and Western blot analysis, respectively. The role of S727 phosphorylation in the crosstalk between ERK1/2 and STAT3 was determined by a transient transfection study using a STAT3S727A mutant. Cardiomyocyte hypertrophy was evaluated by the cellular protein-to-DNA ratio and [(3)H]-leucine incorporation. RESULTS: CT-1 simultaneously activated both ERK1/2 and STAT3 in rat cardiomyocytes. Inhibition of ERK1/2 by U0126 resulted in an increase of CT-1-induced tyrosine phosphorylation of STAT3 and, consequently, the protein-to-DNA ratio and [(3)H]-leucine incorporation. Transient transfection of the cells with STAT3S727A had no significant effect on CT-1-induced tyrosine phosphorylation of STAT3. CONCLUSIONS: STAT3 is activated by CT-1 in rat cardiomyocytes, but full activation is mitigated by the simultaneous activation of ERK1/2. The inhibition of ERK1/2 increases the activity of STAT3, which, in turn, enhances the hypertrophic effect of CT-1. The crosstalk between ERK1/2 and STAT3 is independent of the phosphorylation of the S727 in STAT3. Such crosstalk may contribute to the development of adequate cardiac hypertrophy.

Different contributions of STAT3, ERK1/2, and PI3-K signaling to cardiomyocyte hypertrophy by cardiotrophin-1.

AIM: To assess the contribution of signal transducer and activator of transcription 3 (JAK-STAT3) pathway, extracellular signal-regulated kinases1/2 (ERK1/2) pathway, and phosphatidylinositol 3-kinase (PI3-K) pathway to cardiomyocytes hypertrophy induced by cardiotrophin-1 (CT-1), a new member of interleukin-6 (IL-6) family of cytokines. METHODS: STAT3, ERK1/2, and PI3-K were assessed by Western blot analysis. Activity of ERK1/2 was also confirmed by in-gel kinase assay. Hypertrophy of cardiomyocyte was evaluated by [3H]leucine incorporation and cellular protein-to-DNA ratio. RESULTS: CT-1 simultaneously activated phosphorylation of STAT3, ERK1/2, and PI3-K in rat cardiomyocytes. Parthenolide, an inhibitor of STAT, suppressed CT-1-induced [3H]leucine incorporation by 88.3 % and protein-to-DNA ratio by 75.0 %. U0126, an MEK1/2 inhibitor, increased CT-1-induced the phosphorylation of STAT3 in a dose-dependent manner and, consistently, augmented CT-1-induced increase in [3H]leucine incorporation and cellular protein-to-DNA ratio by 17.6 % and 16.3 %, respectively. Wortmannin, a PI3-K inhibitor, did not influence CT-1-induced [3H]leucine incorporation and cellular protein-to-DNA ratio. CONCLUSION: The hypertrophic effect of CT-1 was essentially mediated by STAT3, independent of PI3-K, and negatively regulated by ERK1/2 via inhibiting the phosphorylation of STAT3. The interaction between STAT3 and ERK1/2 in CT-1-induced signaling contributes to development of cardiac hypertrophy.