Notch1 signaling activation alleviates coronary microvascular dysfunction through histone modification of Nrg-1 via the interaction between NICD and GCN5.

The Notch signaling pathway is related to endothelial dysfunction in coronary atherosclerosis. Our objective was to explore the role of Notch signaling in coronary microvascular dysfunction (CMD). CMD models were constructed by sodium laurate injection in vivo and homocysteine (Hcy) stimulation in vitro. The binding ability of Notch Intracellular Domain (NICD)/H3K9Ac/GCN5 (General Control Non-derepressible 5) to Neuregulin-1 (Nrg-1) promoter was examined by chromatin immunoprecipitation. Immunofluorescence staining was conducted to detect CD31 positive cells, NICD localization, and co-localization of NICD and GCN5. Flow cytometry and Tunel staining were conducted to identify the apoptosis. Hematoxylin and eosin staining, quantitative real-time PCR, western blot, immunohistochemical staining, co-immunoprecipitation, and double luciferase report analysis were also conducted. Notch signaling pathway-related protein levels were decreased, levels of Nrg-1 and the phosphorylation of ErbB2 and ErbB4 were enhanced in CMD models. Interference with Nrg-1 further increased the apoptosis in Hcy-induced cardiac microvascular endothelial cells (CMECs). Meanwhile, the activation of the Notch signaling pathway increased the levels of Nrg-1 and the phosphorylation of ErbB2 and ErbB4, as well as inhibited the apoptosis induced by Hcy. Furthermore, NICD and histone acetyltransferase enzyme GCN5 could regulate Nrg-1 promoter activity by affecting the expression of acetylation-modified protein H3K9Ac. In addition, NICD also interacted with GCN5. In vivo results also confirmed that the activation of the Notch signal alleviated CMD. Notch signaling pathway regulates Nrg-1 level through synergistic interaction with GCN5, thereby mitigating CMD.

Comparison of Intracoronary and Intravenous Ultrasound-targeted Microbubble Destruction-mediated Ang1 Gene Transfection on Left Ventricular Remodeling in Canines With Acute Myocardial Infarction.

Intravenous ultrasound-targeted microbubble destruction (IV-UTMD) has made distinct but limited progress in gene therapy. Intracoronary (IC) injection may lead to more gene transfection than IV injection. This study compared the therapeutic effects of IC-UTMD-mediated and conventional IV-UTMD-mediated gene transfection in acute myocardial infarction (MI). A canine MI model was successfully established through transcatheter coronary artery embolism, and the animals were divided into several treatment groups: IC injection with UTMD and the negative control plasmid (IC-UTMD); IC injection of the angiopoietin 1 (Ang1) plasmid (IC-Ang1); IC injection with UTMD and the Ang1 plasmid (IC-UTMD-Ang1); and IV injection with UTMD and the Ang1 plasmid (IV-UTMD-Ang1). At 12 hours after injection, more green fluorescence was observed from the fluorescein isothiocyanate-labeled Ang1 plasmid in the IC-UTMD-Ang1 group. After 1 month, compared with the IV-UTMD-Ang1 group, echocardiography showed that the IC-UTMD-Ang1 group exhibited increased left ventricular systolic function and myocardial infusion, with lower fibrous tissue levels and higher blood vessel density and Ang1 mRNA and protein levels. Similar cardiac troponin I and N-terminal pro-B type natriuretic peptide levels were observed in all groups. Compared with IV-UTMD, IC-UTMD can enhance Ang1 plasmid transfection efficiency after MI, promote gene expression and angiogenesis, and improve left ventricular remodeling without decreasing safety.

Drug-coated balloons for the treatment of ostial left anterior descending or ostial left circumflex artery lesions: a patient-level propensity score-matched analysis.

BACKGROUND: Controversy exists as to the optimal treatment approach for ostial left anterior descending (LAD) or ostial left circumflex artery (LCx) lesions. Drug-coated balloons (DCB) may overcome some of the limitations of drug-eluting stents (DES). Therefore, we investigated the security and feasibility of the DCB policy in patients with ostial LAD or ostial LCx lesions, and compared it with the conventional DES-only strategy. METHODS: We retrospectively enrolled patients with de novo ostial lesions in the LAD or LCx who underwent interventional treatment. They were categorized into two groups based on their treatment approach: the DCB group and the DES group. The treatment strategies in the DCB group involved the use of either DCB-only or hybrid strategies, whereas the DES group utilized crossover or precise stenting techniques. Two-year target lesion revascularization was the primary endpoint, while the rates of major adverse cardiovascular events, cardiac death, target vessel myocardial infarction, and vessel thrombosis were the secondary endpoints. Using propensity score matching, we assembled a cohort with comparable baseline characteristics. To ensure result analysis reliability, we conducted sensitivity analyses, including interaction, and stratified analyses. RESULTS: Among the 397 eligible patients, 6.25% of patients who were planned to undergo DCB underwent DES. A total of 108 patients in each group had comparable propensity scores and were included in the analysis. Two-year target lesion revascularization occurred in 5 patients (4.90%) and 16 patients (16.33%) in the DCB group and the DES group, respectively (odds ratio = 0.264, 95% CI: 0.093-0.752, P = 0.008). Compared with the DES group, the DCB group demonstrated a lower major adverse cardiovascular events rate (7.84% vs. 19.39%, P = 0.017). However, differences with regard to cardiac death, non-periprocedural target vessel myocardial infarction, and definite or probable vessel thrombosis between the groups were non-significant. CONCLUSIONS: The utilization of the DCB approach signifies an innovative and discretionary strategy for managing isolated ostial lesions in the LAD or LCx. Nevertheless, a future randomized trial investigating the feasibility and safety of DCB compared to the DES-only strategy specifically for de novo ostial lesions in the LAD or LCx is highly warranted.

E3 ubiquitin ligase mind bomb 1 overexpression reduces apoptosis and inflammation of cardiac microvascular endothelial cells in coronary microvascular dysfunction.

BACKGROUND: The apoptosis and inflammation in cardiac microvascular endothelial cells (CMECs) promote the development of coronary microvascular dysfunction (CMD). The present study aimed to explore the role of E3 ubiquitin ligase mind bomb 1 (MIB1) in the apoptosis and inflammation in CMECs during CMD. METHODS: In vivo, CMD in rats was induced by sodium laurate injection. In vitro, rat primary CMECs were stimulated by homocysteine (Hcy). The apoptosis of CMECs was measured using flow cytometry. The inflammation of CMECs was evaluated by the level of tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1ß). The interplay between MIB1 and mitogen-activated protein kinase kinase kinase 5 (map3k5, also called ASK1) was measured using Co-immunoprecipitation. RESULTS: MIB1 expression was decreased and ASK1 expression was increased in the heart tissues of CMD rats and Hcy-treated CMECs. MIB1 overexpression decreased fibrinogen-like protein 2 (FGL2) secretion, inflammation, and apoptosis induced by Hcy in CMECs. Meanwhile, MIB1 overexpression decreased the protein levels of ASK1 and p38, while not affected ASK1 mRNA levels. The following mechanism experiments revealed that MIB1 downregulated ASK1 expression by increasing its ubiquitination. ASK1 overexpression reversed the inhibitory effect of MIB1 on FGL2 secretion, apoptosis, inflammation, and p38 activation in Hcy-treated CMECs. In CMD rats, MIB1 overexpression partly retarded CMD progression, manifesting as increased coronary capillary density and decreased microthrombi formation. CONCLUSION: MIB1 overexpression relieved apoptosis and inflammation of CMECs during CMD by targeting the ASK1/p38 pathway.

Stentless at ostium: a novel approach for treating ostial left anterior descending or left circumflex coronary artery lesions with drug-coated balloons.

BACKGROUND: Currently, there is no optimal treatment strategy for ostial left anterior descending (LAD) or ostial left circumflex artery (LCx) lesions. This study explored effectiveness and safety of drug-coated balloons (DCB) in individuals presenting with ostial LAD or LCx lesions. METHODS: A total of 137 patients with de novo ostial LAD or LCx lesions scheduled for DCB treatment were prospectively recruited into the study. After mandatory lesion preparation, DCB-only or hybrid strategy [DCB + drug-eluting stent (DES)] were performed on 120 patients (87.59%). The primary endpoint was the rate of 2-year target lesion revascularization (TLR). Rates of major adverse cardiovascular events (MACE), cardiac death, target vessel myocardial infarction (TVMI), and vessel thrombosis were explored as the secondary outcomes. Quantitative coronary angiography software was used to analyze coronary angiograms. RESULTS: Of the participants, 58 were treated with DCB-only and 62 with hybrid strategy. Relative to the DCB-only group, patients in the hybrid group had longer target lesions (15.47 ± 10.08 vs. 36.85 ± 9.46 mm, P<0.001) and higher Synergy between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery (SYNTAX) scores (23.47 ± 5.22 vs. 29.98 ± 3.18, P<0.001). During follow-up (731 ± 64 days), neither the primary endpoint (TLR) nor the secondary endpoints (including MACE, cardiac death, TVMI, and vessel thrombosis) differed statistically between the two groups (all P > 0.05). Treatment strategy (DCB-only or hybrid) was not a significant risk factor for TLR. Patients who underwent DCB-only exhibited less late lumen loss compared with the patients who underwent hybrid strategy (-0.26 ± 0.59 vs. 0.42 ± 0.47 mm, P<0.001) at 1-year angiographic follow-up. CONCLUSIONS: With regards to safety and efficacy, the strategy of DCB as a standalone therapy was similar in comparison with the hybrid strategy of DCB + DES for ostial LAD and ostial LCx lesions. This approach might be effective and technically easy in treating ostial LAD and LCx diseases.

Bailcalin Protects against Diabetic Cardiomyopathy through Keap1/Nrf2/AMPK-Mediated Antioxidative and Lipid-Lowering Effects.

Previous studies demonstrated that Bailcalin (BAI) prevented cardiac injuries under different disease models. Whether BAI protected against type 2 diabetes mellitus- (T2DM-) associated cardiomyopathy was investigated in this study. T2DM was established by the combination of streptozotocin injection and high-fat diet in mice. BAI was administered daily for 6 months. After evaluating cardiac functions, mice hearts were removed and processed for morphological, biochemical, and molecular mechanism analyses. Neonatal rat cardiomyocytes (NRCM) were isolated and treated with high glucose and palmitate (HG/Pal) for in vitro investigation. BAI significantly ameliorated T2DM-induced cardiomyocyte hypertrophy, interstitial fibrosis, and lipid accumulation accompanied by markedly improved cardiac functions in diabetic mice. Mechanically, BAI restored decreased phosphorylation of AMPK and enhanced expression and nuclei translocation of Nrf2. In in vitro experiments, BAI also prevented NRCM from HG/Pal-induced apoptosis and oxidative stress injuries by increasing p-AMPK and Nrf2 accumulation. The means by which BAI restored p-AMPK seemed to be related to the antioxidative effects of Nrf2 after silencing AMPK or Nrf2 in NRCM. Furthermore, BAI regulated Nrf2 by inhibiting Nrf2 ubiquitination and consequent degradation mediated by Keap1. This study showed that BAI alleviated diabetes-associated cardiac dysfunction and cardiomyocyte injuries in vivo and in vitro via Keap1/Nrf2/AMPK-mediated antioxidation and lipid-lowering effects. BAI might be a potential adjuvant drug for diabetes cardiomyopathy treatment.

Activin A inhibition attenuates sympathetic neural remodeling following myocardial infarction in rats.

Inflammation serves a critical role in driving sympathetic neural remodeling following myocardial infarction (MI), and activin A has been implicated as an important mediator of the inflammatory response post­MI. However, whether activin A impacts sympathetic neural remodeling post­MI remains unclear. In the present study, the authors assessed the effects of activin A on sympathetic neural remodeling in a rat model of MI. Rats were randomly divided into sham, MI, and MI + follistatin­300 (FS, activin A inhibitor) groups. Cardiac tissues from the peri­infarct zone were assessed for expression of sympathetic neural remodeling and inflammatory factors in rats 4 weeks post­MI by western blotting and immunohistochemical methods. Heart function was assessed by echocardiography. It is demonstrated that FS administration significantly reduced post­MI upregulation of activin A, nerve growth factor protein lever, and the density of nerve fibers with positive and protein expression of sympathetic neural remodeling markers in nerve fibers, which included growth associated protein 43 and tyrosine hydroxylase. In addition, inhibition of activin A reduced cardiac inflammation post­MI based on the reduction of i) interleukin­1 and tumor necrosis factor­α protein expression, ii) numbers and/or proportional area of infiltrating macrophages and myofibroblasts and iii) phosphorylated levels of p65 and IκBα. Furthermore, activin A inhibition lessened heart dysfunction post­MI. These results suggested that activin A inhibition reduced sympathetic neural remodeling post­MI in part through inhibition of the inflammatory response. The current study implicates activin A as a potential therapeutic target to circumvent sympathetic neural remodeling post-MI.