Genetic ablation of Cullin-RING E3 ubiquitin ligase 7 restrains pressure overload-induced myocardial fibrosis

The E3 ubiquitin ligases regulate inflammation in cardiovascular diseases

Accumulating evidence has illustrated that the E3 ubiquitin ligases critically participate in the development and progression of cardiovascular diseases. Dysregulation of E3 ubiquitin ligases exacerbates cardiovascular diseases. Blockade or activation of E3 ubiquitin ligases mitigates cardiovascular performance. Therefore, in this review, we mainly introduced the critical role and underlying molecular mechanisms of E3 ubiquitin ligase NEDD4 family in governing the initiation and progression of cardiovascular diseases, including ITCH, WWP1, WWP2, Smurf1, Smurf2, Nedd4-1 and Nedd4-2. Moreover, the functions and molecular insights of other E3 ubiquitin ligases, such as F-box proteins, in cardiovascular disease development and malignant progression are described. Furthermore, we illustrate several compounds that alter the expression of E3 ubiquitin ligases to alleviate cardiovascular diseases. Therefore, modulation of E3 ubiquitin ligases could be a novel and promising strategy for improvement of therapeutic efficacy of deteriorative cardiovascular diseases.

Cardioprotective Effects of Dexmedetomidine in an Oxidative-Stress In Vitro Model of Neonatal Rat Cardiomyocytes

Preterm birth is a risk factor for cardiometabolic disease. The preterm heart before terminal differentiation is in a phase that is crucial for the number and structure of cardiomyocytes in further development, with adverse effects of hypoxic and hyperoxic events. Pharmacological intervention could attenuate the negative effects of oxygen. Dexmedetomidine (DEX) is an α2-adrenoceptor agonist and has been mentioned in connection with cardio-protective benefits. In this study, H9c2 myocytes and primary fetal rat cardiomyocytes (NRCM) were cultured for 24 h under hypoxic condition (5% O₂), corresponding to fetal physioxia (pO₂ 32-45 mmHg), ambient oxygen (21% O₂, pO₂ ~150 mmHg), or hyperoxic conditions (80% O₂, pO₂ ~300 mmHg). Subsequently, the effects of DEX preconditioning (0.1 µM, 1 µM, 10 µM) were analyzed. Modulated oxygen tension reduced both proliferating cardiomyocytes and transcripts (CycD2). High-oxygen tension induced hypertrophy in H9c2 cells. Cell-death-associated transcripts for caspase-dependent apoptosis (Casp3/8) increased, whereas caspase-independent transcripts (AIF) increased in H9c2 cells and decreased in NRCMs. Autophagy-related mediators (Atg5/12) were induced in H9c2 under both oxygen conditions, whereas they were downregulated in NRCMs. DEX preconditioning protected H9c2 and NRCMs from oxidative stress through inhibition of transcription of the oxidative stress marker GCLC, and inhibited the transcription of both the redox-sensitive transcription factors Nrf2 under hyperoxia and Hif1α under hypoxia. In addition, DEX normalized the gene expression of Hippo-pathway mediators (YAP1, Tead1, Lats2, Cul7) that exhibited abnormalities due to differential oxygen tensions compared with normoxia, suggesting that DEX modulates the activation of the Hippo pathway. This, in the context of the protective impact of redox-sensitive factors, may provide a possible rationale for the cardio-protective effects of DEX in oxygen-modulated requirements on survival-promoting transcripts of immortalized and fetal cardiomyocytes.

Roles of Cullin-RING Ubiquitin Ligases in Cardiovascular Diseases

Maintenance of protein homeostasis is crucial for virtually every aspect of eukaryotic biology. The ubiquitin-proteasome system (UPS) represents a highly regulated quality control machinery that protects cells from a variety of stress conditions as well as toxic proteins. A large body of evidence has shown that UPS dysfunction contributes to the pathogenesis of cardiovascular diseases. This review highlights the latest findings regarding the physiological and pathological roles of cullin-RING ubiquitin ligases (CRLs), an essential player in the UPS, in the cardiovascular system. To inspire potential therapeutic invention, factors regulating CRL activities are also discussed.

Recent Advances in Gene Therapy for Cardiac Tissue Regeneration

Cardiovascular diseases (CVDs) are responsible for enormous socio-economic impact and the highest mortality globally. The standard of care for CVDs, which includes medications and surgical interventions, in most cases, can delay but not prevent the progression of disease. Gene therapy has been considered as a potential therapy to improve the outcomes of CVDs as it targets the molecular mechanisms implicated in heart failure. Cardiac reprogramming, therapeutic angiogenesis using growth factors, antioxidant, and anti-apoptotic therapies are the modalities of cardiac gene therapy that have led to promising results in preclinical studies. Despite the benefits observed in animal studies, the attempts to translate them to humans have been inconsistent so far. Low concentration of the gene product at the target site, incomplete understanding of the molecular pathways of the disease, selected gene delivery method, difference between animal models and humans among others are probable causes of the inconsistent results in clinics. In this review, we discuss the most recent applications of the aforementioned gene therapy strategies to improve cardiac tissue regeneration in preclinical and clinical studies as well as the challenges associated with them. In addition, we consider ongoing gene therapy clinical trials focused on cardiac regeneration in CVDs.