Cellular Membrane-Engineered Nanovesicles as a Three-Stage Booster to Target the Lesion Core.

The lesion core is the area with the most serious injury and vigorous repair. Existing nanocarriers are difficult to break through the targeted delivery to the lesion core for precise treatment in the intracellular and extracellular microenvironment. Herein, a cellular membrane-engineered nanovesicle (CMEV) with a hierarchical structure is constructed using the double emulsion-extrusion method by integrating a neutrophil membrane, functional antibody, and gelled drug-loaded core as a three-stage booster to target the lesion core and deliver catestatin (CST), a small therapeutic peptide, for ischemic cardiomyopathy therapy. By coating the neutrophil membrane outside the shell, CMEV is endowed with the function of neutrophil-like migration to achieve the first stage of tissue targeting. Based on the specific anchoring to injured myocardium, a myosin light chain 3 (MLC3) antibody is embedded to fulfill the second stage of CMEV accumulation in the lesion core. The gelled core containing CST-sodium alginate (NaAlg) with a pH-responsive shell is prepared by ionic cross-linking to accomplish the third stage of precise CST administration. Triggered by the microenvironment, NaAlg electrostatically adheres to the lesion core for sustained release, enhancing the efficacy of CST in improving cardiomyocyte apoptosis, excessive fibrosis, macrophage polarization, and angiogenesis. Thus, the "three-stage booster" nanovesicle significantly ameliorates cardiac function and adverse remodeling to treat ischemic cardiomyopathy.

Catestatin Protects Against Diastolic Dysfunction by Attenuating Mitochondrial Reactive Oxygen Species Generation.

Background Catestatin has been reported as a pleiotropic cardioprotective peptide. Heart failure with preserved ejection fraction (HFpEF) was considered a heterogeneous syndrome with a complex cause. We sought to investigate the role of catestatin in HFpEF and diastolic dysfunction. METHODS AND RESULTS Administration of recombinant catestatin (1.5 mg/kg/d) improved diastolic dysfunction and left ventricular chamber stiffness in transverse aortic constriction mice with deoxycorticosterone acetate pellet implantation, as reflected by Doppler tissue imaging and pressure-volume loop catheter. Less cardiac hypertrophy and myocardial fibrosis was observed, and transcriptomic analysis revealed downregulation of mitochondrial electron transport chain components after catestatin treatment. Catestatin reversed mitochondrial structural and respiratory chain component abnormality, decreased mitochondrial proton leak, and reactive oxygen species generation in myocardium. Excessive oxidative stress induced by Ru360 abolished catestatin treatment effects on HFpEF-like cardiomyocytes in vitro, indicating the beneficial role of catestatin in HFpEF as a mitochondrial ETC modulator. The serum concentration of catestatin was tested among 81 patients with HFpEF and 76 non-heart failure controls. Compared with control subjects, serum catestatin concentration was higher in patients with HFpEF and positively correlated with E velocity to mitral annular e' velocity ratio, indicating a feedback compensation role of catestatin in HFpEF. Conclusions Catestatin protects against diastolic dysfunction in HFpEF through attenuating mitochondrial electron transport chain-derived reactive oxygen species generation. Serum catestatin concentration is elevated in patients with HFpEF, probably as a relatively insufficient but self-compensatory mechanism.

Nuclear Tkt promotes ischemic heart failure via the cleaved Parp1/Aif axis.

Transketolase (Tkt), an enzyme in pentose phosphate pathway, has been reported to regulate genome instability and cell survival in cancers. Yet, the role of Tkt after myocardial ischemic injury remains to be elucidated. Label-free proteomics revealed dramatic elevation of Tkt in murine hearts after myocardial infarction (MI). Lentivirus-mediated Tkt knockdown ameliorated cardiomyocyte apoptosis and preserved the systolic function after myocardial ischemic injury. In contrast, Tkt overexpression led to the opposite effects. Inducible conditional cardiomyocyte Tkt-knockout mice were generated, and cardiomyocyte-expressed Tkt was found to play an intrinsic role in the ischemic heart failure of these model mice. Furthermore, through luciferase assay and chromatin immunoprecipitation, Tkt was shown to be a direct target of transcription factor Krüppel-like factor 5 (Klf5). In cardiomyocytes under ischemic stress, Tkt redistributed into the nucleus. By binding with the full-length poly(ADP-ribose) polymerase 1 (Parp1), facilitating its cleavage, and activating apoptosis inducible factor (Aif) subsequently, nuclear Tkt demonstrated its non-metabolic functions. Overall, our study confirmed that elevated nuclear Tkt plays a noncanonical role in promoting cardiomyocyte apoptosis via the cleaved Parp1/Aif pathway, leading to the deterioration of cardiac dysfunction.

Outcomes of Spironolactone Withdrawal in Dilated Cardiomyopathy With Improved Ejection Fraction.

Background: The feasibility of spironolactone withdrawal in dilated cardiomyopathy patients with improved ejection fraction remains unknown. This study sought to determine whether spironolactone can be withdrawn safely in this circumstance. Methods: Consecutive patients with idiopathic dilated cardiomyopathy and prescribed spironolactone at discharge were included in this prospective, observational cohort using the Risk Evaluation and Management in Heart Failure Trial (NCT02998788) database. Those patients who experienced an absolute left ventricular ejection fraction (LVEF) improvement ≥10% and a second measurement of LVEF >40% would choose whether to continue spironolactone therapy and be included in final analysis. The primary endpoint was dilated cardiomyopathy relapse within 12 months, defined as a more than 10% reduction in LVEF, a 15% or greater increase in LVESVi, a 2-fold rise in NT-proBNP, or clinical signs of heart failure. Results: Seventy patients achieved an ejection fraction improvement and were included in the final analysis, of whom 30 chose to continue spironolactone and 40 decided to withdraw. In primary endpoint analysis, 23 (58%) patients from the withdrawal group and 4 (13%) patients from the continuation group relapsed (relative risk for relapse: 4.31; 95% CI: 1.67-11.11; p < 0.001). Patients from the withdrawal group experienced more symptom aggravation than the continuation group. No secondary safety endpoint was recorded. Improvements in cardiac structure parameters were no longer observed after spironolactone withdrawal, while improvements persisted in continuation group. Conclusions: Most dilated cardiomyopathy patients with improved ejection fraction will relapse after spironolactone withdrawal. These results should be weighed before spironolactone withdrawal was attempted.

Myocardial fibrosis reversion via rhACE2-electrospun fibrous patch for ventricular remodeling prevention.

Myocardial fibrosis and ventricular remodeling were the key pathology factors causing undesirable consequence after myocardial infarction. However, an efficient therapeutic method remains unclear, partly due to difficulty in continuously preventing neurohormonal overactivation and potential disadvantages of cell therapy for clinical practice. In this study, a rhACE2-electrospun fibrous patch with sustained releasing of rhACE2 to shape an induction transformation niche in situ was introduced, through micro-sol electrospinning technologies. A durable releasing pattern of rhACE2 encapsulated in hyaluronic acid (HA)-poly(L-lactic acid) (PLLA) core-shell structure was observed. By multiple in vitro studies, the rhACE2 patch demonstrated effectiveness in reducing cardiomyocytes apoptosis under hypoxia stress and inhibiting cardiac fibroblasts proliferation, which gave evidence for its in vivo efficacy. For striking mice myocardial infarction experiments, a successful prevention of adverse ventricular remodeling has been demonstrated, reflecting by improved ejection fraction, normal ventricle structure and less fibrosis. The rhACE2 patch niche showed clear superiority in long term function and structure preservation after ischemia compared with intramyocardial injection. Thus, the micro-sol electrospun rhACE2 fibrous patch niche was proved to be efficient, cost-effective and easy-to-use in preventing ventricular adverse remodeling.

Circulating PGLYRP1 Levels as a Potential Biomarker for Coronary Artery Disease and Heart Failure.

ABSTRACT: Coronary artery disease (CAD) and associated comorbidities such as heart failure (HF) remain the leading cause of morbidity and mortality worldwide attributed to, at least partially, the lack of biomarkers for efficient disease diagnosis. Here, we evaluated the diagnostic potential of serum peptidoglycan recognition protein 1 (PGLYRP1), an important component of the innate immunity and inflammation system, for both CAD and HF. A machine-learning method (random forest) was used to evaluate the clinical utility of circulating PGLYRP1 for diagnosis of CAD and HF in a total of 370 individuals. Causal links of chronic serum PGLYRP1 elevation to both diseases were further explored in ApoE-/- mice. The serum levels of PGLYRP1 were significantly higher in individuals with either chronic CAD or acute coronary syndrome than those in those without coronary artery stenosis (the control group) and even more pronounced in CAD individuals with concomitant HF. Our random forest classifier revealed that this protein performed better than other recommended clinical indicators in distinguishing the CAD from the control individuals. In addition, this protein associates more with the biomarkers of HF including left ventricular ejection fraction than inflammation. Notably, our mice experiment indicated that long-term treatment with recombinant PGLYRP1 could significantly impair the cardiovascular system as reflected from both increased atherogenic lesions and reduced fractional shortening of the left ventricle. Our findings, therefore, supported the circulating levels of PGLYRP1 as a valuable biomarker for both CAD and HF.

Effects of Cardiomyocyte-Specific Deletion of STAT3-A Murine Model of Heart Failure With Preserved Ejection Fraction.

Aims: There is a high incidence of heart failure with preserved ejection fraction (HFpEF), but the options of treatment are limited. A new animal model of HFpEF is urgently needed for in-depth research on HFpEF. Signal transducer and activator of transcription 3 (STAT3) may affect the passive stiffness of myocardium, which determines cardiac diastolic function. We hypothesized that cardiomyocyte-specific deletion of STAT3 increases cardiac passive stiffness, which results the murine features of HFpEF. Methods and Results: Cardiomyocyte-specific deletion of STAT3 (STAT3cKO) mice was generated by the Cre/FLOXp method. The STAT3cKO mice showed heavier cardiac fibrosis and cardiac hypertrophy comparing with wild-type (WT) mice. Furthermore, STAT3cKO mice showed increased serum brain natriuretic peptide (BNP) level, and growth stimulation expressed gene 2 (ST2) level. Other indicators reflecting cardiac passive stiffness and diastolic function, including end diastolic pressure volume relation, MV A value, MV E value, E/A and E/E' had different fold changes. All these changes were accompanied by decreasing levels of protein kinase G (PKG). Bioinformatic analysis of STAT3cKO mice hearts suggested cGMP-PKG signaling pathway might participate in the pathogenesis of HFpEF by means of adjusting different biological functions. Conclusions: Cardiomyocyte-specific deletion of STAT3 results in a murine HFpEF model which imitates the clinical characteristics partly by affecting cardiac PKG levels. Better understanding of the factors influencing HFpEF may finally provided innovative therapies.

BMI1 promotes cardiac fibrosis in ischemia-induced heart failure via the PTEN-PI3K/Akt-mTOR signaling pathway.

Cardiac fibrosis has been known to play an important role in the etiology of heart failure after myocardial infarction (MI). B lymphoma Mo-MLV insertion region 1 homolog (BMI1), a transcriptional repressor, is important for fibrogenesis in the kidneys. However, the effect of BMI1 on ischemia-induced cardiac fibrosis remains unclear. BMI1 was strongly expressed in the infarct region 1 wk post-MI in mice and was detected by Western blot and histological analyses. Lentivirus-mediated overexpression of BMI1 significantly promoted cardiac fibrosis, worsened cardiac function 4 wk after the intervention in vivo, and enhanced the proliferation and migration capabilities of fibroblasts in vitro , whereas downregulation of BMI1 decreased cardiac fibrosis and prevented cardiac dysfunction in mice 4 wk post-MI in vivo. Furthermore, upregulated BMI1 inhibited phosphatase and tensin homolog (PTEN) expression, enhanced phosphatidylinositol 3-kinase (PI3K) expression, and increased the phosphorylation level of Akt and mammalian target of rapamycin (mTOR) in mice 4 wk after lentiviral infection, which was in accordance with the changes seen in their infarcted myocardial tissues. At the same time, the effects of BMI1 on cardiac fibroblasts were reversed in vitro when these cells were exposed to NVP-BEZ235, a dual-kinase (PI3K/mTOR) inhibitor. In conclusion, BMI1 is associated with cardiac fibrosis and dysfunction after MI by regulating cardiac fibroblast proliferation and migration, and these effects could be partially explained by the regulation of the PTEN-PI3K/Akt-mTOR pathway. NEW & NOTEWORTHY Ischemia-induced B lymphoma Mo-MLV insertion region 1 homolog (BMI1) significantly promoted cardiac fibrosis and worsened cardiac function in vivo, whereas downregulation of BMI1 decreased cardiac fibrosis and prevented cardiac dysfunction in myocardial infarcted mice. BMI1 also enhanced proliferation and migration capabilities of fibroblasts in vitro; these effects were reversed by NVP-BEZ235. Effects of BMI1 on cardiac fibrosis could be partially explained by regulation of the phosphatase and tensin homolog-phosphatidylinositol 3-kinase/Akt-mammalian target of rapamycin pathway.