Low-Dose Colchicine Ameliorates Doxorubicin Cardiotoxicity Via Promoting Autolysosome Degradation.

BACKGROUND: The only clinically approved drug that reduces doxorubicin cardiotoxicity is dexrazoxane, but its application is limited due to the risk of secondary malignancies. So, exploring alternative effective molecules to attenuate its cardiotoxicity is crucial. Colchicine is a safe and well-tolerated drug that helps reduce the production of reactive oxygen species. High doses of colchicine have been reported to block the fusion of autophagosomes and lysosomes in cancer cells. However, the impact of colchicine on the autophagy activity within cardiomyocytes remains inadequately elucidated. Recent studies have highlighted the beneficial effects of colchicine on patients with pericarditis, postprocedural atrial fibrillation, and coronary artery disease. It remains ambiguous how colchicine regulates autophagic flux in doxorubicin-induced heart failure. METHODS AND RESULTS: Doxorubicin was administered to establish models of heart failure both in vivo and in vitro. Prior studies have reported that doxorubicin impeded the breakdown of autophagic vacuoles, resulting in damaged mitochondria and the accumulation of reactive oxygen species. Following the administration of a low dose of colchicine (0.1 mg/kg, daily), significant improvements were observed in heart function (left ventricular ejection fraction: doxorubicin group versus treatment group=43.75%±3.614% versus 57.07%±2.968%, P=0.0373). In terms of mechanism, a low dose of colchicine facilitated the degradation of autolysosomes, thereby mitigating doxorubicin-induced cardiotoxicity. CONCLUSIONS: Our research has shown that a low dose of colchicine is pivotal in restoring the autophagy activity, thereby attenuating the cardiotoxicity induced by doxorubicin. Consequently, colchicine emerges as a promising therapeutic candidate to improve doxorubicin cardiotoxicity.

An integration-free iPSC line ZZUNEUi029-A derived from peripheral blood mononuclear cells of a patient with familial hypercholesterolemia carrying a mutation in LDLR gene.

Familial hypercholesterolemia is a hereditary disorder that causes severely elevated low-density lipoprotein levels, which can lead to an increased risk for premature cardiovascular disease. Mutations in the LDLR gene are the most common cause of familial hypercholesterolemia. In this study, we report the generation of ZZUNEUi029-A, a human induced pluripotent stem cell line (hiPSC) from a male patient with c. 622 G â†’ A in LDLR gene using non-integrative Sendai viral reprogramming technology. This cell line expressed pluripotency markers, had a normal male karyotype (46XY) and maintained the ability to differentiate into the three germ layers in vitro.

IL-38 attenuates myocardial ischemia-reperfusion injury by inhibiting macrophage inflammation.

BACKGROUND: Reperfusion therapy is the most effective approach to resolve coronary occlusion, but myocardial injury caused by excessive inflammation during myocardial ischemia-reperfusion will also pose a new threat to health. Our prior study revealed the expression pattern of interleukin-38 (IL-38) in the peripheral blood serum of patients with ischemic cardiomyopathy and the role of IL-38 in acute myocardial infarction in mice. However, its role and potential mechanisms in myocardial ischemia/reperfusion injury (MIRI) remain to be determined. METHODS AND RESULTS: The left anterior descending artery of C57BL/6 mice was transiently ligated to induce the MIRI model. We found that MIRI induced the expression of endogenous IL-38, which was mainly produced by locally infiltrating macrophages. Overexpression of IL-38 in C57BL/6 mice attenuated inflammatory injury and decreased myocardial apoptosis after myocardial ischemia-reperfusion. Furthermore, IL-38 inhibited lipopolysaccharide-induced macrophage inflammation in vitro. Cardiomyocytes cocultured with the supernatant of IL-38- and troponin I-treated macrophages showed a lower rate of apoptosis than controls. CONCLUSIONS: IL-38 attenuates MIRI by inhibiting macrophage inflammation. This inhibitory effect may be partially achieved by inhibiting the activation of NOD-like receptor pyrin domain-related protein 3 inflammasome, resulting in decreased expression of inflammatory factors and reduced cardiomyocyte apoptosis.

Analysis of the Correlation Between the Ratio of Monocytes to High-Density Lipoprotein Cholesterol and in-Stent Restenosis in Patients with Premature Coronary Heart Disease.

BACKGROUND: High-density lipoprotein cholesterol (HDL-C) and monocytes are associated with coronary artery disease, and the ratio of monocytes to high-density lipoprotein (MHR) is associated with long-term adverse outcomes and the recurrence of atrial fibrillation. Currently, the trend of coronary heart disease proned to young people is becoming prominent. However, the relationship between MHR and in-stent restenosis (ISR) in patients with premature coronary heart disease (PCHD) has not been investigated. Therefore, we aimed to assess the relationship between MHR and ISR in patients with PCHD. METHODS: We retrospectively included 257 patients (men ≤ 55 years old, women ≤ 65 years old) with PCHD who underwent drug-eluting stent implantation and follow-up coronary angiography at the First Affiliated Hospital of Zhengzhou University from September 2016 to September 2019. Patients were divided into ISR and non-ISR groups depending on their follow-up coronary angiography results. Relative clinical information was recorded and analyzed. A receiver operating characteristic curve analysis was used to determine the optimum pre-procedural MHR cutoff value to predict ISR. RESULTS: Logistic regression analysis showed that MHR, smoking history, and fibrinogen were independent risk factors for ISR in patients with PCHD. The area under the receiver operating characteristic curve (AUC) of MHR was 0.750 (95% confidence interval, 0.695-0.820; P < .001), the cutoff value was 546.88, and the specificity and sensitivity were 65.2% and 78%, while the AUC of monocytes was 0.631 (95% confidence interval, 0.638-0.794; P < .001), the cutoff value was 590, and the specificity and sensitivity were 77.1% and 60.0%. CONCLUSION: MHR is an independent risk factor for ISR in patients with PCHD and showed a certain predictive value.

Ginkgo biloba extract-761 protects myocardium by regulating Akt/Nrf2 signal pathway.

OBJECTIVE: The aim of this study was to investigate the protective effect and mechanism of Ginkgo biloba extract-761 (EGb 761) in the rat with myocardial ischemia-reperfusion injury (MIRI). MATERIALS AND METHODS: Forty Sprague Dawley rats were randomly divided into following four groups: sham group, I/R group and EGb 761 groups (20 and 40 mg/kg). MIRI model was established after 14 days of administration. The myocardial infarct size and myocardial histology were measured and compared. Meanwhile, the levels of creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), troponin T (TnT), TNF-α, IL-6, IL-1ß, superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were evaluated. Western blot was used to detect the expression of Caspase-3, Bax, Bcl-2, HO-1, Nrf2, Akt, p-Akt and nuclear protein Nrf2. RESULTS: The levels of infarct size, CK-MB, LDH, TnT, TNF-α, IL-6 and IL-1ß in the EGb 761 groups were significantly lower than those in the ischemia/reperfusion (I/R) group. The content of MDA was lower in the myocardium, whereas the activities of SOD and GSH-Px were higher than those in the I/R group. The expressions of Caspase-3 and Bax in the EGb 761 groups were significantly lower than those in the I/R group, whereas the expressions of Bcl-2, p-Akt and HO-1 and nuclear protein Nrf2 in the EGb 761 groups were higher than those in the I/R group. CONCLUSION: EGb 761 might inhibit the apoptosis of myocardial cells and protect the myocardium by activating the Akt/Nrf2 pathway, increasing the expression of HO-1, decreasing oxidative stress and repressing inflammatory reaction.

Metformin improves cardiac function in rats via activation of AMP-activated protein kinase.

1. Metformin is one of the most commonly used drugs for the treatment of Type 2 diabetes. Accumulating evidence suggests that metformin also has cardioprotective effects. In the present study, we investigated the cardioprotective effects of metformin and the mechanisms involved. 2. A rat model of chronic heart failure was established by permanent left coronary artery occlusion. Heart failure rats were randomly divided into four groups: (i) a saline-treated group given 4 mL/kg day via intragastric gavage; (ii) a metformin-treated group, given 100 mg/kg metformin once daily via intragastric gavage; (iii) a group treated with 5 mg/kg 5'-aminoimidazole-4-carboxyamide-ribonucleoside (AICAR), an AMP-activated protein kinase (AMPK) agonist, every second day; and (iv) a group treated with 100 mg/kg per day metformin + 20 mg/kg, i.p., compound C (an AMPK antagonist). After 4 weeks treatment, echocardiography was used to assess left ventricular (LV) dimensions and function. Expression of AMPK, endothelial nitric oxide synthase (eNOS) and transforming growth factor (TGF)-ß1 was determined by reverse transcription-polymerase chain reaction and western blot analysis. 3. Metformin administration significantly improved cardiac function and LV remodelling, as evidenced by increases in LV systolic pressure and LV ejection fraction and decreases in LV end-diastolic diameter and LV end-systolic diameter. These beneficial effects of metformin were associated with increased AMPK and eNOS phosphorylation, as well as reductions in insulin, TGF-ß1, basic fibroblast growth factor and tumour necrosis factor-α levels in the circulation and/or myocardium. 4. The results indicate that chronic low-dose metformin confers significant cardioprotective effects against chronic heart failure by activating the AMPK-eNOS pathway.