Fluorescence monitoring of refluxed tyrosinase using endoplasmic reticulum-localized enzymatic activity-based sensing.

A tyrosinase-activatable fluorescent probe with endoplasmic reticulum targetability was developed for the first time. It can ratiometrically fluoresce and hence be used to monitor refluxed tyrosinase into the endoplasmic reticulum.

Rap1GAP exacerbates myocardial infarction by regulating the AMPK/SIRT1/NF-κB signaling pathway.

Rap1 GTPase-activating protein (Rap1GAP) is an important tumor suppressor. The purpose of this study was to investigate the role of Rap1GAP in myocardial infarction (MI) and its potential mechanism. Left anterior descending coronary artery ligation was performed on cardiac-specific Rap1GAP conditional knockout (Rap1GAP-CKO) mice and control mice with MI. Seven days after MI, Rap1GAP expression in the hearts of control mice peaked, the expression of proapoptotic markers (Bax and cleaved caspase-3) increased, the expression of antiapoptotic factors (Bcl-2) decreased, and the expression of the inflammatory factors IL-6 and TNF-α increased; thus, apoptosis occurred, inflammation, infarct size, and left ventricular dysfunction increased, while the heart changes caused by MI were alleviated in Rap1GAP-CKO mice. Mouse heart tissue was obtained for transcriptome sequencing, and gene set enrichment analysis (GSEA) was used to analyze Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. We found that Rap1GAP was associated with the AMPK and NF-κB signaling pathways and that Rap1GAP inhibited AMPK/SIRT1 and activated the NF-κB signaling pathway in model animals. Similar results were observed in primary rat myocardial cells subjected to oxygen-glucose deprivation (OGD) to induce ischemia and hypoxia. Activating AMPK with the AMPK activator 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) reversed the damage caused by Rap1GAP overexpression in cardiomyocytes. In addition, the coimmunoprecipitation results showed that exogenous Rap1GAP interacted with AMPK. Rap1GAP was verified to regulate the AMPK SIRT1/NF-κB signaling pathway and exacerbate the damage to myocardial cells caused by ischemia and hypoxia. In conclusion, our results suggest that Rap1GAP promotes MI by modulating the AMPK/SIRT1/NF-κB signaling pathway and that Rap1GAP may be a therapeutic target for MI treatment in the future.

Recent Progress in the Rational Design of Biothiol-Responsive Fluorescent Probes.

Biothiols such as cysteine, homocysteine, and glutathione play significant roles in important biological activities, and their abnormal concentrations have been found to be closely associated with certain diseases, making their detection a critical task. To this end, fluorescent probes have become increasingly popular due to their numerous advantages, including easy handling, desirable spatiotemporal resolution, high sensitivity, fast response, and favorable biocompatibility. As a result, intensive research has been conducted to create fluorescent probes for the detection and imaging of biothiols. This brief review summarizes recent advances in the field of biothiol-responsive fluorescent probes, with an emphasis on rational probe design, including the reaction mechanism, discriminating detection, reversible detection, and specific detection. Furthermore, the challenges and prospects of fluorescence probes for biothiols are also outlined.

Rap1GAP Mediates Angiotensin II-Induced Cardiomyocyte Hypertrophy by Inhibiting Autophagy and Increasing Oxidative Stress.

Abnormal autophagy and oxidative stress contribute to angiotensin II- (Ang II-) induced cardiac hypertrophy and heart failure. We previously showed that Ang II increased Rap1GAP gene expression in cardiomyocytes associated with hypertrophy and autophagy disorders. Using real-time PCR and Western blot, we found that Rap1GAP expression was increased in the heart of Sprague Dawley (SD) rats infused by Ang II compared with saline infusion and in Ang II vs. vehicle-treated rat neonatal cardiomyocytes. Overexpression of Rap1GAP in cultured cardiomyocytes exacerbated Ang II-induced cardiomyocyte hypertrophy, reactive oxygen species (ROS) generation, and cell apoptosis and inhibited autophagy. The increased oxidative stress caused by Rap1GAP overexpression was inhibited by the treatment of autophagy agonists. Knockdown of Rap1GAP by siRNA markedly attenuated Ang II-induced cardiomyocyte hypertrophy and oxidative stress and enhanced autophagy. The AMPK/AKT/mTOR signaling pathway was inhibited by overexpression of Rap1GAP and activated by the knockdown of Rap1GAP. These results show that Rap1GAP-mediated pathway might be a new mechanism of Ang II-induced cardiomyocyte hypertrophy, which could be a potential target for the future treatment of cardiac hypertrophy and heart failure.

Ivabradine Improves Cardiac Function and Increases Exercise Capacity in Patients with Chronic Heart Failure.

To systematically review and conduct a meta-analysis of the ivabradine-induced improvement in cardiopulmonary function, exercise capacity, and primary composite endpoints in patients with chronic heart failure (CHF).This study was a systematic review and meta-analysis.Databases, including PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Clinical Trials and European Union Clinical Trials, were searched for randomized placebo-controlled trials. The efficacy and safety of ivabradine treatment in patients with CHF were assessed and compared to those of the standard anti-heart failure treatment. Review Manager 5.3 software was used to analyze the relative risk (RR) for dichotomous data and the mean difference (MD) for continuous data.In total, 22 studies with 24,562 patients were included. Cardiopulmonary function analysis showed that treatment with added ivabradine reduced the heart rate (MD = -17.30, 95% confidence interval (CI): 19.52--15.08, P < 0.00001), significantly increased the left ventricular ejection fraction (LVEF) (MD = 3.90, 95% CI: 0.40-7.40, P < 0.0001), and led to a better New York Heart Association (NYHA) classification. Ivabradine significantly reduced the minute ventilation/carbon dioxide production (VE/VCO2) (MD = -2.68, 95% CI: -4.81--0.55, P = 0.01) and improved the peak VO2 (MD = 2.80, 95% CI: 1.05-4.55, P = 0.002) and the exercise capacity, including the exercise duration with a submaximal load (MD = 7.82, 95% CI: -2.57--18.21, P < 0.00001) and the 6-minute walk distance. The RR of cardiovascular death or worsening heart failure was significantly decreased (RR = 0.93, 95% CI: 0.87--0.98, P = 0.01) in the patients treated with ivabradine. Additionally, the RRs of heart failure and hospitalization also decreased (RR = 0.91, 95% CI: 0.85--0.97, P = 0.006; RR = 0.86, 95% CI: 0.79--0.93, P = 0.0002). Safety analysis showed no significant difference in the RR of severe adverse events between the ivabradine group and the standard anti-heart failure treatment group (P = 0.40). However, ivabradine significantly increased the RR of visual symptoms in CHF patients (RR = 3.82, 95% CI: 1.80--8.13, P = 0.0005).Existing evidence showed that adding ivabradine treatment significantly improved the cardiopulmonary function and increased the exercise capacity of patients with CHF. Adding ivabradine to the standard anti-heart failure treatment reduced the mortality and hospitalization risk and improved the quality of life. Finally, ivabradine significantly increased the RR of visual symptoms in CHF patients.This is the first systematic review and meta-analysis to focus on the efficacy of ivabradine, which improved the cardiac function and increased the exercise capacity in patients with chronic heart failure (CHF). Therefore, this study will help evaluate the quality of life after adding ivabradine to the treatment of patients with CHF, even though there are differences in the standard for resting heart rate, left ventricular ejection fraction (LVEF), and New York Heart Association (NYHA) class in the included studies. This hybrid effect might be smaller when analyzed separately but might have a higher heterogeneity when analyzed in multiple studies.

Trillium tschonoskii maxim extract attenuates abnormal Tau phosphorylation.

Large-scale epidemiological studies have found that hyperhomocysteinemia is a powerful, independent risk factor for Alzheimer's disease. Trillium tschonoskii maxim is a traditional Chinese medicine that is used to promote memory. However, scientific understanding of its mechanism of action is limited. This report studied the potential neuroprotective effects of Trillium tschonoskii maxim extract against homocysteine-induced cognitive deficits. Rats were intravenously injected with homocysteine (400 µg/kg) for 14 days to induce a model of Alzheimer's disease. These rats were then intragastrically treated with Trillium tschonoskii maxim extract (0.125 or 0.25 g/kg) for 7 consecutive days. Open field test and Morris water maze test were conducted to measure spontaneous activity and learning and memory abilities. Western blot assay was used to detect the levels of Tau protein and other factors involved in Tau phosphorylation in the hippocampus. Immunohistochemical staining was used to examine Tau protein in the hippocampus. Golgi staining was applied to measure hippocampal dendritic spines. Our results demonstrated that homocysteine produced learning and memory deficits and increased levels of Tau phosphorylation, and diminished the activity of catalytic protein phosphatase 2A. The total number of hippocampal dendritic spines was also decreased. Trillium tschonoskii maxim extract treatment reversed the homocysteine-induced changes. The above results suggest that Trillium tschonoskii maxim extract can lessen homocysteine-induced abnormal Tau phosphorylation and improve cognitive deterioration such as that present in Alzheimer's disease.

Effect of oral atorvastatin on CD4+CD25+ regulatory T cells, FoxP3 expression, and prognosis in patients with ST-segment elevated myocardial infarction before primary percutaneous coronary intervention.

OBJECTIVE: Our objective was to explore the effects of atorvastatin on changes of CD4+CD25+ regulatory T cells (Tregs), FoxP3 expression in the infarct-related coronary artery, and peripheral venous blood of patients with ST-segment elevation myocardial infarction. METHODS: We recorded 112 cases of patients with ST-segment elevation myocardial infarction who were randomly assigned to receive either atorvastatin 80 mg (n = 52) or placebo (n = 60) before primary percutaneous coronary intervention. Blood samples were obtained from the infarct-related coronary artery and peripheral vein during percutaneous coronary intervention. The proportion of CD4+CD25+ Tregs, FoxP3 mRNA expression in blood and concentrations of transforming growth factor-ß and interferon-γ in plasma of the samples were measured or detected by flow cytometry, real-time polymerase chain reaction, or enzyme-linked immunosorbent assay, respectively. RESULTS: In comparison with the control group, the proportions of CD4+CD25+ Tregs and the mRNA level of FoxP3 and transforming growth factor-ß significantly increased; however, interferon-γ decreased with atorvastatin therapy. In the controls, the proportions of CD4+CD25+ Tregs and the mRNA level of FoxP3 and transforming growth factor-ß were significantly decreased, but the level of interferon-γ increased more in the infarct-related coronary artery than in the peripheral vein. CONCLUSION: : The inhibition of CD4+CD25+ Tregs in patients with ST-segment elevation myocardial infarction could be regulated with atorvastatin given before percutaneous coronary intervention.