Protective Effects and Mechanisms of Recombinant Human Glutathione Peroxidase 4 on Isoproterenol-Induced Myocardial Ischemia Injury

Myocardium-targeted liposomal delivery of the antioxidant peptide 8P against doxorubicin-induced myocardial injury

Doxorubicin (Dox) is a broad-spectrum antineoplastic chemotherapeutic agent used in clinical settings, yet it exhibits significant cardiotoxicity, which in severe cases can lead to heart failure. Research indicates that oxidative stress plays a pivotal role in Dox -induced cardiomyocyte injury. Therefore, the application of antioxidants represents an effective strategy to mitigate the cardiotoxic effects of doxorubicin. In preliminary studies, we isolated an antioxidative peptide, PHWWEYRR (8P). This study utilizes a PCM cardiomyocyte-targeting peptide-modified liposome as a carrier to deliver 8P into cardiomyocytes, aiming to prevent Dox-induced cardiac injury through its antioxidative mechanism. The results demonstrated that we prepared the 8P-loaded and PCM-targeting peptide-modified liposome (P-P-8P), which exhibited good dispersibility, encapsulation efficiency, drug loading capacity, and in vitro release, along with myocardial targeting capability. In vitro experiments showed that P-P-8P could prevent oxidative stress injury in H9C2 cells, protect mitochondrial functions, and inhibit cell apoptosis through a mitochondria-dependent pathway. In vivo experiments indicated that P-P-8P could prevent abnormalities in serum biochemical indicators, cardiac dysfunction, and myocardial pathological changes in mice. In conclusion, P-P-8P effectively delivers 8P to cardiomyocytes, offering protection against the cardiotoxic effects of Dox, and holds potential as a future preventative or therapeutic agent for drug-induced cardiomyopathy.

Advances in Ferroptosis-Inducing Agents by Targeted Delivery System in Cancer Therapy

Currently, cancer remains one of the most significant threats to human health. Treatment of most cancers remains challenging, despite the implementation of diverse therapies in clinical practice. In recent years, research on the mechanism of ferroptosis has presented novel perspectives for cancer treatment. Ferroptosis is a regulated cell death process caused by lipid peroxidation of membrane unsaturated fatty acids catalyzed by iron ions. The rapid development of bio-nanotechnology has generated considerable interest in exploiting iron-induced cell death as a new therapeutic target against cancer. This article provides a comprehensive overview of recent advancements at the intersection of iron-induced cell death and bionanotechnology. In this respect, the mechanism of iron-induced cell death and its relation to cancer are summarized. Furthermore, the feasibility of a nano-drug delivery system based on iron-induced cell death for cancer treatment is introduced and analyzed. Secondly, strategies for inducing iron-induced cell death using nanodrug delivery technology are discussed, including promoting Fenton reactions, inhibiting glutathione peroxidase 4, reducing low glutathione levels, and inhibiting system Xc-. Additionally, the article explores the potential of combined treatment strategies involving iron-induced cell death and bionanotechnology. Finally, the application prospects and challenges of iron-induced nanoagents for cancer treatment are discussed.

Iron Dysregulation in Cardiovascular Diseases

Iron metabolism plays a crucial role in various physiological functions of the human body, as it is essential for the growth and development of almost all organisms. Dysregulated iron metabolism-manifested either as iron deficiency or overload-is a significant risk factor for the development of cardiovascular disease (CVD). Moreover, emerging evidence suggests that ferroptosis, a form of iron-dependent programed cell death, may also contribute to CVD development. Understanding the regulatory mechanisms of iron metabolism and ferroptosis in CVD is important for improving disease management. By integrating different perspectives and expertise in the field of CVD-related iron metabolism, this overview provides insights into iron metabolism and CVD, along with approaches for diagnosing, treating, and preventing CVD associated with iron dysregulation.

PLGA nanoparticles enhanced cardio-protection of scutellarin and paeoniflorin against isoproterenol-induced myocardial ischemia in rats

This study aims to examine the impact of the microfluidic preparation process on the quality of poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) co-delivered with scutellarin (SCU) and paeoniflorin (PAE) in comparison to a conventional emulsification method and to evaluatethe potential cardio-protective effect of SCU-PAE PLGA NPs produced through emulsification method. As compared with microfluidics, the nanoparticles prepared by emulsification method exhibited a smaller size, higher encapsulation efficiency, higher drug loading and lower viscosity for injection. Subsequently, a rat myocardial ischemia (MI) was established using male Sprague-Dawley (SD) rats (250 ± 20 g) subcutaneously injected with 85 mg/kg isoproterenol (ISO) for two consecutive days. The pharmacokinetic findings demonstrated that our SCU-PAE PLGA NPs exhibited prolonged blood circulation time in MI rats, leading to increased levels of SCU and PAE in the heart. This resulted in significant improvements in electrocardiogram and cardiac index, as well as reduced serum levels of CK, LDH, AST. Histopathological analysis using H&E and TUNEL staining provided further evidence of improved cardiac function and decreased apoptosis. Additionally, experiments measuring SOD, MDA, GSH, NO, TNF-α and IL-6 levels indicated that SCU-PAE PLGA NPs may effectively treat MI through oxidative stress and inflammatory pathways, thereby establishing it as a promising therapeutic intervention.

Comparison of moderate-intensity continuous training and high-intensity interval training effects on the Ido1-KYN-Ahr axis in the heart tissue of rats with occlusion of the left anterior descending artery

Myocardial infarction (MI) affects many molecular pathways in heart cells, including the Ido1-KYN-Ahr axis. This pathway has recently been introduced as a valuable therapeutic target in infarction. We examined the effects of moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT) on the axis in the heart tissue of male Wistar rats with occluded left anterior descending (OLAD). Thirty rats (age 10-12 weeks, mean weight 275 ± 25 g) were divided into five groups with 6 animals: Control (Ct) group, MICT group, rats with OLAD as MI group, rats with OLAD treated with MICT (MIMCT group) and rats with OLAD treated with HIIT (MIHIIT group). Rats performed the training protocols for 8 weeks, 5 days a week. HIIT included 7 sets of 4 min running with an intensity of 85-90% VO₂max and 3 min of recovery activation between sets. MICT included continuous running at the same distance as HIIT with an intensity of 50-60% VO₂max for 50 min. The expressions of Ahr, Cyp1a1, and Ido1 were assayed by real-time PCR. Malondialdehyde (MDA) and Kynurenine levels, and AHR, CYP1A1, and IDO1 proteins were detected using ELISA. Data were analyzed using the ANOVA and MANOVA tests. Compared to the CT group, MI caused an increase in all studied factors, but only statistically significant (P < 0.05) for MDA and IDO1. With a greater effect of HIIT, both protocols significantly lowered the proteins expressions in the MIHIIT and MIMCT groups, compared with the MI group (P < 0.001). In healthy rats, only AHR protein significantly decreased in the MICT group compared to the Ct group (P < 0.05). HIIT and MICT protocols significantly reduced the gene and protein expression of Cyp1a1 (P < 0.05) and Ido1 (P < 0.01), and HIIT had a greater effect. In conclusion, both protocols were effective at reducing the levels of Ido1-Kyn-Ahr axis components and oxidative stress in the infarcted heart tissue and HIIT had a higher significant effect.

Ciprofol attenuates the isoproterenol-induced oxidative damage, inflammatory response and cardiomyocyte apoptosis

Background and Purpose: Ciprofol (HSK3486), a novel 2,6-disubstituted phenol derivative, is a new intravenous anesthetic compound with a similar chemical structure to propofol. Animal studies have also shown that propofol plays a protective role in a variety of cardiovascular diseases, including myocardial infarction, myocardial ischemia-reperfusion injury and takotsubo syndrome. However, whether ciprofol exerts cardioprotective effects on myocardial infarction remains unclear. Thus, the aim of this work was to explore the potential cardioprotective mechanism of ciprofol on isoproterenol (ISO)-induced myocardial infarction. Experimental Approach: In the present study, male C57BL/6 mice were subjected to subcutaneous injection of ISO (100 mg/kg) for 2 consecutive days to induce experimental myocardial infarction. Herein, we found that ciprofol could inhibit the abnormal increase in myocardial injury enzymes, the area of myocardial infarction and cardiac dysfunction in ISO-treated mice. Ciprofol administration increased the activity of superoxide dismutase and reduced the levels of NADPH oxidase and malondialdehyde in ISO-treated hearts. Additionally, ciprofol administration markedly reduced the expression of pro-inflammatory cytokines and cardiomyocyte apoptosis. In an in vitro model, the results also confirmed that ciprofol could inhibit ISO-induced oxidative damage, the inflammatory response and cardiomyocyte apoptosis. Moreover, ciprofol can activate the sirtuin1 (Sirt1)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway and Sirt1 and Nrf2 inhibition almost abolished ciprofol-mediated cardioprotective effects. Interpretation: Ciprofol protects the heart against ISO-induced myocardial infarction by reducing cardiac oxidative stress, the inflammatory response and cardiomyocyte apoptosis.

Ferroptosis due to Cystathionine γ Lyase/Hydrogen Sulfide Downregulation Under High Hydrostatic Pressure Exacerbates VSMC Dysfunction

Hydrostatic pressure, stretch, and shear are major biomechanical forces of vessels and play critical roles in genesis and development of hypertension. Our previous work demonstrated that high hydrostatic pressure (HHP) promoted vascular smooth muscle cells (VSMCs) two novel subsets: inflammatory and endothelial function inhibitory VSMCs and then exacerbated VSMC dysfunction. However, the underlying mechanism remains unknown. Here, we first identified that aortic GPX4 (a core regulator of ferroptosis) significantly downregulated association with VSMC novel phenotype elevation in SHR rats and hypertension patients. In primary VSMCs, HHP (200 mmHg) increased iron accumulation, ROS production, and lipid peroxidation compared with normal pressure (100 mmHg). Consistently, the ferroptosis-related gene (COX-2, TFRC, ACSL4, and NOX-1) expression was also upregulated. The ferroptosis inhibitor ferrostatin-1 (Fer-1) administration blocked HHP-induced VSMC inflammatory (CXCL2 expression) and endothelial function inhibitory (AKR1C2 expression) phenotyping switch association with elevation in the GPX4 expression, reduction in the reactive oxygen species (ROS), and lipid peroxidation production. In contrast, the ferroptosis inducer RLS3 increased HHP-induced CXCL2 and AKR1C2 expressions. These data indicate HHP-triggering ferroptosis contributes to VSMC inflammatory and endothelial function inhibitory phenotyping switch. In mechanism, HHP reduced the VSMC GSH content and cystathionine gamma-lyase (CSE)/hydrogen sulfide (H₂S)—an essential system for GSH generation. Supplementation of the H₂S donor-NaHS increased the VSMC GSH level, alleviated iron deposit, ROS and lipid peroxidation production. NaHS administration rescues both HHP- and RLS3-induced ferroptosis. Collectively, HHP downregulated VSMC CSE/H₂S triggering GSH level reduction, resulting in ferroptosis, which contributed to the genesis of VSMC inflammation and endothelial function inhibitory phenotypes.