Bardoxolone methyl attenuates doxorubicin-induced cardiotoxicity by inhibiting the TXNIP-NLRP3 pathway through Nrf2 activation.

Bardoxolone methyl, which triggers nuclear factor erythroid 2-related factor (Nrf2), has therapeutic effects against myocardial infarction, heart failure, and other diseases. Nrf2 can inhibit the activation of the thioredoxin-interacting protein (TXNIP)/NLR family pyrin domain-containing protein 3 (NLRP3) pathway. Doxorubicin is an anthracycline chemotherapeutic drug associated with cardiotoxicity, limiting its clinical use. In this study, we explored the specific mechanism of the Nrf2-TXNIP-NLRP3 pathway in doxorubicin-induced cardiotoxicity using bardoxolone methyl in animal and cell models. Using in vivo and in vitro experiments, we show that doxorubicin can induce oxidative stress and pyroptosis in the heart. Western blot and co-immunoprecipitation experimental results found that doxorubicin can reduce the interaction between TXNIP and TRX, increase the interaction between TXNIP and NLRP3, and activate the pyroptosis process. Bardoxolone methyl reduces the accumulation of reactive oxygen species in cardiomyocytes through the Nrf2 pathway, inhibits the interaction between TXNIP and NLRP3, and alleviates the progression of myocardial damage and cardiac fibrosis. Bardoxolone methyl lost its therapeutic effect when the expression of Nrf2 was decreased. Additionally, repressing the expression of TXNIP can inhibit the activation of NLRP3 and alleviate myocardial damage caused by doxorubicin. Collectively, our findings confirm that bardoxolone methyl alleviates doxorubicin-induced cardiotoxicity by activating Nrf2 and inhibiting the TXNIP-NLRP3 pathway.

Resveratrol inhibits ferroptosis and decelerates heart failure progression via Sirt1/p53 pathway activation.

Resveratrol is an organic compound widely studied for its therapeutic uses. We investigated whether resveratrol exerts cardioprotective effects by inhibiting ferroptosis via the Sirt1/p53 pathway. A heart failure model was established by aortic coarctation in Sirt1 knockout mice. The superoxide dismutase (SOD), glutathione (GSH) levels and mitochondrial morphology in murine heart tissues were assessed at different time points to determine the role of ferroptosis in heart failure progression. The cardiac function of mice with heart failure was evaluated by determining the brain natriuretic peptide (BNP) and sST2 concentration and conducting echocardiography. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were transfected with the p53 K382R mutant and Sirt1 interference lentiviral vectors. Immunoprecipitation (IP) experiments were performed to investigate whether Sirt1 influences ferroptosis via p53 K382 acetylation and SLC7A11 expression modulation. Resveratrol improved cardiac function in mice and decelerated ferroptosis and fibrosis progression in heart failure. However, the ability of resveratrol to prevent ferroptosis and treat heart failure was lost after silencing Sirt1. Sirt1 reduced ferroptosis by diminishing the levels of p53 K382 acetylation, reducing the degradation of SLC7A11, and increasing the levels of GSH and glutathione peroxidase 4 (GPX4) in cells. In conclusion, by activating the Sirt1/p53 pathway in heart failure, resveratrol decreased the depletion of SLC7A11, inhibited ferroptosis, and improved cardiac function.

Positive correlations between plasma BPI level and MPO-DNA and S100A8/A9 in myocardial infarction.

Bactericidal/permeability-increasing protein (BPI) exhibits a number of important characteristics. RNA-seq analysis revealed that the BPI expression was increased in platelets of (non)ST-elevated myocardial infarction (NSTEMI/STEMI) patients. Activated platelets can induce NETosis which may be accompanied by the release of myeloperoxidase-DNA (MPO-DNA) and S100A8/A9. This study investigated the plasma BPI levels in myocardial infarction patients and its correlation with MPO-DNA and S100A8/A9. This prospective study recruited 80 control individuals, as well as 63 NSTEMI and 59 STEMI patients who were admitted to the First Affiliated Hospital of Bengbu Medical College for coronary angiography (CAG) and/or percutaneous coronary intervention (PCI) between May 1, 2020 and August 31, 2020. Demographic and clinical characteristics, clinical indicators, hs-CRP, IL-1ß, MPO-DNA (a circulated marker of NETs), circulating levels of S100A8/A9 and BPI were measured from each individual. The severity of coronary lesions was evaluated by the Gensini score, based on the results of the CAG. Pearson's or spearman's correlation was used to examine the correlation between BPI and the above-mentioned parameters, as well as the severity of coronary artery disease. Linear regression analysis was applied to identify the independent predictive factors of BPI. Received operating characteristic (ROC) curve analysis was used to evaluate the diagnostic efficacy of plasma BPI for MI. The plasma BPI levels increased by 8.76 times in the STEMI group and 5.38 times in the NSTEMI group compared to the control group. The plasma level of hs-CRP and IL-1ß in both STEMI and NSTEMI groups were also significantly higher than the control group. In addition, the plasma levels of MPO-DNA and S100A8/A9 in the STEMI and NSTEMI groups were significantly higher than the control group. Plasma levels of BPI were positively correlated with IL-1ß, hs-CRP, MPO-DNA and S100A8/A9. The correlation between BPI and the severity of coronary artery disease was also significant. The optimal cutoff value of plasma BPI was 35.1705 ng/ml for MI patients from the ROC curve analysis. Plasma BPI levels are increased in myocardial infarction patients and positively correlated with MPO-DNA and S100A8/A9. Plasma BPI level may serve as a potential biomarker of myocardial infarction.

Correlation of serum N-Acetylneuraminic acid with the risk and prognosis of acute coronary syndrome: a prospective cohort study.

BACKGROUND: N-acetylneuraminic acid (Neu5Ac) is a functional metabolite involved in coronary artery disease (CAD). We aimed to evaluate the relationship between serum Neu5Ac and the risk and prognosis of acute coronary syndrome (ACS) in a real-world prospective study. METHODS: Patients with suspected ACS who underwent coronary angiography were included. Serum Neu5Ac was measured at admission. Coronary lesion severity was evaluated by Gensini Score. GRACE risk stratification was performed at admission. Major adverse cardiac events (MACEs) were recorded during follow-up. RESULTS: A total of 766 patients, including 537 with unstable angina (UAP), 100 with myocardial infarction (MI), and 129 without CAD were included. The circulating Neu5Ac level was significantly higher in patients with MI (median [1QR]: 297[220, 374] ng/ml) than in those with UAP (227 [114, 312] ng/ml) or without CAD (207 [114, 276] ng/ml; both p < 0.001). Serum level of Neu5Ac was positively correlated with age, hypertension, serum uric acid, creatinine, MB isoform of creatine kinase (CK-MB), and Gensini score (all p < 0.05). Receiver operating characteristic curve analysis showed that a higher serum Neu5Ac was potentially associated with MI and high-risk GRACE stratification in ACS patients. Logistic analysis identified only elevated serum Neu5Ac as an independent predictor of MACEs in these patients (odds ratio [OR]: 1.003, 95% confidence interval [CI]: 1.002-1.005, p < 0.001). CONCLUSIONS: Serum Neu5Ac is associated with myocardial injury, GRACE risk category, and prognosis in ACS patients.

[Correlation of plasma N-acetyl-neuraminic acid level with TIMI risk stratification and clinical outcomes in patients with acute coronary syndrome].

OBJECTIVE: To explore the correlation of plasma N-acetyl-neuraminic acid level with Thrombolysis In Myocardial Infarction (TIMI) risk score and clinical outcomes of patients with acute coronary syndrome (ACS). METHODS: We consecutively enrolled 708 consecutive patients (401 male and 307 female, mean age 63.6±10.6 years) undergoing coronary angiography in our hospital between October, 2018 and July, 2019, including 597 patients with ACS and 111 without ACS (control group). The patients with ACS group were divided into high (n=104), moderate (n=425) and low (n=68) risk groups according to their TIMI risk scores. All the participants were examined for plasma Neu5Ac level using liquid chromatography-tandem mass spectrometry and underwent coronary angiography with their Gensini scores calculated. The patients with ACS were followed up after discharge for a mean of 15 months for the occurrence of major adverse cardiac events (Mace). Binary logistic regression analysis was performed to identify the risk factors of Mace in these patients. RESULTS: Plasma Neu5Ac levels were significantly higher in ACS group than in the control group (P < 0.05). ROC curve analysis showed that plasma Neu5Ac level could assist in the diagnosis of ACS (0.648 [0.597-0.699]) with a sensitivity of 39.2% and a specificity of 86.5% at the cutoff value of 288.50 ng/mL. In the ACS patients, plasma Neu5Ac level was significantly higher in the high-risk group than in the moderate-risk and low-risk groups (P < 0.05) and could assist in the diagnosis of a high risk (0.645 [0.588-0.703]) with a sensitivity of 42.3% and a specificity of 80.1% at the cutoff value of 327.50 ng/ mL. Plasma Neu5Ac was positively correlated with age, serum uric acid, creatinine, lipoprotein a, Ddimer, C-reactive protein, MB isoform of creatine kinase and Gensini score and negatively correlated with high-density lipoprotein level. During the followup, 80 ACS patients experienced Mace, who had significantly higher plasma Neu5Ac level than those without Mace (n=517). Logistic regression analysis showed that plasma Neu5Ac level and a history of previous stroke were independent risk factors for the occurrence of Mace. CONCLUSIONS: Plasma Neu5Ac level can provide assistance in the diagnosis and risk stratification of ACS and is an independent risk factor for prognosis of ACS patients.