Targeting WWP1 ameliorates cardiac ischemic injury by suppressing KLF15-ubiquitination mediated myocardial inflammation.

Rationale: Previous studies have suggested that myocardial inflammation plays a critical role after ischemic myocardial infarction (MI); however, the underlying mechanisms still need to be fully elucidated. WW domain-containing ubiquitin E3 ligase 1 (WWP1) is considered as an important therapeutic target for cardiovascular diseases due to its crucial function in non-ischemic cardiomyopathy, though it remains unknown whether targeting WWP1 can alleviate myocardial inflammation and ischemic injury post-MI. Methods: Recombinant adeno-associated virus 9 (rAAV9)-cTnT-mediated WWP1 or Kruppel-like factor 15 (KLF15) gene transfer and a natural WWP1 inhibitor Indole-3-carbinol (I3C) were used to determine the WWP1 function in cardiomyocytes. Cardiac function, tissue injury, myocardial inflammation, and signaling changes in the left ventricular tissues were analyzed after MI. The mechanisms underlying WWP1 regulation of cardiomyocyte phenotypes in vitro were determined using the adenovirus system. Results: We found that WWP1 expression was up-regulated in cardiomyocytes located in the infarct border at the early phase of MI and in hypoxia-treated neonatal rat cardiac myocytes (NRCMs). Cardiomyocyte-specific WWP1 overexpression augmented cardiomyocyte apoptosis, increased infarct size and deteriorated cardiac function. In contrast, inhibition of WWP1 in cardiomyocytes mitigated MI-induced cardiac ischemic injury. Mechanistically, WWP1 triggered excessive cardiomyocyte inflammation after MI by targeting KLF15 to catalyze K48-linked polyubiquitination and degradation. Ultimately, WWP1-mediated degradation of KLF15 contributed to the up-regulation of p65 acetylation, and activated the inflammatory signaling of MAPK in ischemic myocardium and hypoxia-treated cardiomyocytes. Thus, targeting of WWP1 by I3C protected against cardiac dysfunction and remodeling after MI. Conclusions: Our study provides new insights into the previously unrecognized role of WWP1 in cardiomyocyte inflammation and progression of ischemic injury induced by MI. Our findings afford new therapeutic options for patients with ischemic cardiomyopathy.

Proteomic Insights into Cardiac Fibrosis: From Pathophysiological Mechanisms to Therapeutic Opportunities.

Cardiac fibrosis is a common pathophysiologic process in nearly all forms of heart disease which refers to excessive deposition of extracellular matrix proteins by cardiac fibroblasts. Activated fibroblasts are the central cellular effectors in cardiac fibrosis, and fibrotic remodelling can cause several cardiac dysfunctions either by reducing the ejection fraction due to a stiffened myocardial matrix, or by impairing electric conductance. Recently, there is a rising focus on the proteomic studies of cardiac fibrosis for pathogenesis elucidation and potential biomarker mining. This paper summarizes the current knowledge of molecular mechanisms underlying cardiac fibrosis, discusses the potential of imaging and circulating biomarkers available to recognize different phenotypes of this lesion, reviews the currently available and potential future therapies that allow individualized management in reversing progressive fibrosis, as well as the recent progress on proteomic studies of cardiac fibrosis. Proteomic approaches using clinical specimens and animal models can provide the ability to track pathological changes and new insights into the mechanisms underlining cardiac fibrosis. Furthermore, spatial and cell-type resolved quantitative proteomic analysis may also serve as a minimally invasive method for diagnosing cardiac fibrosis and allowing for the initiation of prophylactic treatment.

Enzyme Catalysis Biomotor Engineering of Neutrophils for Nanodrug Delivery and Cell-Based Thrombolytic Therapy.

Utilizing neutrophils (NEs) to target and deliver nanodrugs to inflammation sites has received considerable attention. NEs are involved in the formation and development of thrombosis by transforming into neutrophil extracellular traps (NETs); this indicates that NEs may be a natural thrombolytic drug delivery carrier. However, NEs lack an effective power system to overcome blood flow resistance and enhance targeting efficiency. Herein, we report the application of a urease catalysis micromotor powered NEs nanodrug delivery system to promote thrombolysis and suppress rethrombosis. The urease micromotor powered Janus NEs (UM-NEs) were prepared by immobilizing the enzyme asymmetrically onto the surface of natural NEs and then loading urokinase (UK) coupled silver (Ag) nanoparticles (Ag-UK) to obtain the UM-NEs (Ag-UK) system. Urease catalytic endogenous urea is used to generate thrust by producing ammonia and carbon dioxide, which propels NEs actively targeting the thrombus. The UM-NEs (Ag-UK) can be activated by enriched inflammatory cytokines to release NETs at the thrombosis site, resulting in a concomitant release of Ag-UK. Ag-UK induces thrombolysis to restore vascular recanalization. This urease micromotor-driven NEs drug delivery system can significantly reduce the hemorrhagic side effects, promote thrombolysis, and inhibit rethrombosis with high bioavailability and biosafety, which can be used for the treatment of thrombotic diseases.