The Cardioprotective Mechanism of Phenylaminoethyl Selenides (PAESe) Against Doxorubicin-Induced Cardiotoxicity Involves Frataxin

Protective Role of Dioscin against Doxorubicin-Induced Chronic Cardiotoxicity: Insights from Nrf2-GPX4 Axis-Mediated Cardiac Ferroptosis

Recent evidence suggests that ferroptosis, an iron-facilitated cell death with excessive lipid peroxidation, is a critical mechanism underlying doxorubicin (DOX)-induced cardiotoxicity (DIC). Although dioscin has been reported to improve acute DIC, direct evidence is lacking to clarify the role of dioscin in chronic DIC and its potential mechanism in cardiac ferroptosis. In this study, we used chronic DIC rat models and H9c2 cells to investigate the potential of dioscin to mitigate DIC by inhibiting ferroptosis. Our results suggest that dioscin significantly improves chronic DIC-induced cardiac dysfunction. Meanwhile, it significantly inhibited DOX-induced ferroptosis by reducing Fe2+ and lipid peroxidation accumulation, maintaining mitochondrial integrity, increasing glutathione peroxidase 4 (GPX4) expression, and decreasing acyl-CoA synthetase long-chain family 4 (ACSL4) expression. Through transcriptomic analysis and subsequent validation, we found that the anti-ferroptotic effects of dioscin are achieved by regulating the nuclear factor-erythroid 2-related factor 2 (Nrf2)/GPX4 axis and Nrf2 downstream iron metabolism genes. Dioscin further downregulates nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) and upregulates expression of frataxin (FXN) and ATP-binding cassette B8 (ABCB8) to limit mitochondrial Fe2+ and lipid peroxide accumulation. However, Nrf2 inhibition diminishes the anti-ferroptotic effects of dioscin, leading to decreased GPX4 expression and increased lipid peroxidation. This study is a compelling demonstration that dioscin can effectively reduce DIC by inhibiting ferroptosis, which is dependent on the Nrf2/GPX4 pathway modulation.

Pioglitazone ameliorates DOX-induced cognitive impairment by mitigating inflammation, oxidative stress, and apoptosis of hippocampal neurons in rats

Doxorubicin (DOX) is broadly used as a medication for cancer treatment. However, DOX has been connected with chemotherapy-related complications, for instance, cognitive impairment (chemobrain). Chemobrain developed in up to 70% of cancer patients; therapeutic is unavailable. This study investigated the preventive effect of pioglitazone (PIO) on neurotoxicity caused by (DOX) in the hippocampus. Forty rats were separated into four groups; control (normal saline 10 ml/kg), DOX (5 mg/kg, intraperitoneally every 3rd day, equivalent to 20 mg/kg cumulative dose), PIO (2 mg/kg in drinking water), and DOX+PIO (DOX, 5 mg/kg, intraperitoneally every 3rd day concurrently PIO, 2 mg/kg in drinking water) and duration of drug treatment lasted for 14 days. The animals were subjected to contextual fear memory tests to characterize the cognitive impairment following DOX treatment. ELISA assessed hippocampal protein expression related to inflammation, oxidative damage, and apoptosis. DOX-treatment produced significant reduction in freezing duration in contextual fear memory tests, which was reversed by PIO co-administration. DOX increased neuroinflammation, oxidative stress, apoptosis, and mitochondrial activity by increasing NF-κB and COX-2 levels, reducing SOD levels, and increasing Bax, caspase-3, and lipid peroxidation. However, DOX did not affect GSH or catalase levels. PIO co-administration reduces NF-κB, COX-2, MDA, Bax, and caspase-3 levels and improves mitochondrial activity and SOD expression. To sum up, DOX therapy accelerates cognitive decline in rats by increasing neuroinflammation, oxidative stress, mitochondrial dysfunction, lipid peroxidation, and apoptosis. PIO is a promising treatment for DOX-induced cognitive impairment.

Phenyl-2-aminoethyl selenide ameliorates hippocampal long-term potentiation and cognitive deficits following doxorubicin treatment

Chemotherapy-induced memory loss ("chemobrain") can occur following treatment with the widely used chemotherapeutic agent doxorubicin (DOX). However, the mechanisms through which DOX induces cognitive dysfunction are not clear, and there are no commercially available therapies for its treatment or prevention. Therefore, the aim of this study was to determine the therapeutic potential of phenyl-2-aminoethyl selenide (PAESe), an antioxidant drug previously demonstrated to reduce cardiotoxicity associated with DOX treatment, against DOX-induced chemobrain. Four groups of male athymic NCr nude (nu/nu) mice received five weekly tail-vein injections of saline (Control group), 5 mg/kg of DOX (DOX group), 10 mg/kg PAESe (PAESe group), or 5 mg/kg DOX and 10 mg/kg PAESe (DOX+PAESe group). Spatial memory was evaluated using Y-maze and novel object location tasks, while synaptic plasticity was assessed through the measurement of field excitatory postsynaptic potentials from the Schaffer collateral circuit. Western blot analyses were performed to assess hippocampal protein and phosphorylation levels. In this model, DOX impaired synaptic plasticity and memory, and increased phosphorylation of protein kinase B (Akt) and extracellular-regulated kinase (ERK). Co-administration of PAESe reduced Akt and ERK phosphorylation and ameliorated the synaptic and memory deficits associated with DOX treatment.

The mechanism of ferroptosis and its related diseases

Ferroptosis, a regulated form of cellular death characterized by the iron-mediated accumulation of lipid peroxides, provides a novel avenue for delving into the intersection of cellular metabolism, oxidative stress, and disease pathology. We have witnessed a mounting fascination with ferroptosis, attributed to its pivotal roles across diverse physiological and pathological conditions including developmental processes, metabolic dynamics, oncogenic pathways, neurodegenerative cascades, and traumatic tissue injuries. By unraveling the intricate underpinnings of the molecular machinery, pivotal contributors, intricate signaling conduits, and regulatory networks governing ferroptosis, researchers aim to bridge the gap between the intricacies of this unique mode of cellular death and its multifaceted implications for health and disease. In light of the rapidly advancing landscape of ferroptosis research, we present a comprehensive review aiming at the extensive implications of ferroptosis in the origins and progress of human diseases. This review concludes with a careful analysis of potential treatment approaches carefully designed to either inhibit or promote ferroptosis. Additionally, we have succinctly summarized the potential therapeutic targets and compounds that hold promise in targeting ferroptosis within various diseases. This pivotal facet underscores the burgeoning possibilities for manipulating ferroptosis as a therapeutic strategy. In summary, this review enriched the insights of both investigators and practitioners, while fostering an elevated comprehension of ferroptosis and its latent translational utilities. By revealing the basic processes and investigating treatment possibilities, this review provides a crucial resource for scientists and medical practitioners, aiding in a deep understanding of ferroptosis and its effects in various disease situations.

Human adipose-derived stem cells preconditioned with a novel herbal formulation Jing Shi attenuate doxorubicin-induced cardiac damage

Pathological cardiac hypertrophy is a considerable contributor to global disease burden. Chinese herbal medicine (CHM) has been used to treat cardiovascular diseases since antiquity. Enhancing stem cell-mediated recovery through CHM represents a promising approach for protection against doxorubicin (Dox)-induced cardiac hypertrophy. Herein, we investigated whether human adipose-derived stem cells (hADSCs) preconditioned with novel herbal formulation Jing Si (JS) improved protective ability of stem cells against doxorubicin-induced cardiac damage. The effect of JS on hADSC viability and migration capacity was determined via MTT and migration assays, respectively. Co-culture of hADSC or JS-preconditioned hADSCs with H9c2 cells was analyzed with immunoblot, flow cytometry, TUNEL staining, LC3B staining, F-actin staining, and MitoSOX staining. The in vivo study was performed M-mode echocardiography after the treatment of JS and JS-preconditioned hADSCs by using Sprague Dawley (SD) rats. Our results indicated that JS at doses below 100 μg/mL had less cytotoxicity in hADSC and JS-preconditioned hADSCs exhibited better migration. Our results also revealed that DOX enhanced apoptosis, cardiac hypertrophy, and mitochondrial reactive oxygen species in DOX-challenged H9c2 cells, while H9c2 cells co-cultured with JS-preconditioned hADSCs alleviated these effects. It also enhanced the expression of autophagy marker LC3B, mTOR and CHIP in DOX-challenged H9c2 cells after co-culture with JS-preconditioned hADSCs. In Dox-challenged rats, the ejection fraction and fractional shortening improved in DOX-challenged SD rats exposed to JS-preconditioned hADSCs. Taken together, our data indicate that JS-preconditioned stem cells exhibit a cardioprotective capacity both in vitro and in vivo, highlighting the value of this therapeutic approach for regenerative therapy.

Redox sensitive human mitochondrial aconitase and its interaction with frataxin: In vitro and in silico studies confirm that it takes two to tango

Mitochondrial aconitase (ACO2) has been postulated as a redox sensor in the tricarboxylic acid cycle. Its high sensitivity towards reactive oxygen and nitrogen species is due to its particularly labile [4Fe-4S]²⁺ prosthetic group which yields an inactive [3Fe-4S]⁺ cluster upon oxidation. Moreover, ACO2 was found as a main oxidant target during aging and in pathologies where mitochondrial dysfunction is implied. Herein, we report the expression and characterization of recombinant human ACO2 and its interaction with frataxin (FXN), a protein that participates in the de novo biosynthesis of Fe-S clusters. A high yield of pure ACO2 (≥99%, 22 ± 2 U/mg) was obtained and kinetic parameters for citrate, isocitrate, and cis-aconitate were determined. Superoxide, carbonate radical, peroxynitrite, and hydrogen peroxide reacted with ACO2 with second-order rate constants of 10⁸, 10⁸, 10⁵, and 10² M^-1 s^-1, respectively. Temperature-induced unfolding assessed by tryptophan fluorescence of ACO2 resulted in apparent melting temperatures of 51.1 ± 0.5 and 43.6 ± 0.2 °C for [4Fe-4S]²⁺ and [3Fe-4S]⁺ states of ACO2, sustaining lower thermal stability upon cluster oxidation. Differences in protein dynamics produced by the Fe-S cluster redox state were addressed by molecular dynamics simulations. Reactivation of [3Fe-4S]⁺-ACO2 by FXN was verified by activation assays and direct iron-dependent interaction was confirmed by protein-protein interaction ELISA and fluorescence spectroscopic assays. Multimer modeling and protein-protein docking predicted an ACO2-FXN complex where the metal ion binding region of FXN approaches the [3Fe-4S]⁺ cluster, supporting that FXN is a partner for reactivation of ACO2 upon oxidative cluster inactivation.

Fucoidan Protects against Doxorubicin-Induced Cardiotoxicity by Reducing Oxidative Stress and Preventing Mitochondrial Function Injury

Doxorubicin (DOXO) is a potent chemotherapeutic drug widely used to treat various cancers. However, its clinical application is limited due to serious adverse effects on dose-dependent cardiotoxicity. Although the underlying mechanism has not been fully clarified, DOXO-induced cardiotoxicity has been mainly attributed to the accumulation of reactive oxygen species (ROS) in cardiomyocytes. Fucoidan, as a kind of sulphated polysaccharide existing in numerous brown seaweed, has potent anti-oxidant, immune-regulatory, anti-tumor, anti-coagulate and anti-viral activities. Here, we explore the potential protective role and mechanism of fucoidan in DOXO-induced cardiotoxicity in mice. Our results show that oral fucoidan supplement exerts potent protective effects against DOXO-induced cardiotoxicity by reducing oxidative stress and preventing mitochondrial function injury. The improved effect of fucoidan on DOXO-induced cardiotoxicity was evaluated by echocardiography, cardiac myocytes size and cardiac fibrosis analysis, and the expression of genes related to cardiac dysfunction and remodeling. Fucoidan reduced the ROS content and the MDA levels but enhanced the activity of antioxidant enzymes GSH-PX and SOD in the mouse serum in a DOXO-induced cardiotoxicity model. In addition, fucoidan also increased the ATP production capacity and restored the levels of a mitochondrial respiratory chain complex in heart tissue. Collectively, this study highlights fucoidan as a potential polysaccharide for protecting against DOXO-induced cardiovascular diseases.

Posttranslational regulation of mitochondrial frataxin and identification of compounds that increase frataxin levels in Friedreich's ataxia

Friedreich's ataxia (FRDA) is a degenerative disease caused by a decrease in the mitochondrial protein frataxin (Fxn), which is involved in iron-sulfur cluster (ISC) synthesis. Diminutions in Fxn result in decreased ISC synthesis, increased mitochondrial iron accumulation, and impaired mitochondrial function. Here, we show that conditions that result in increased mitochondrial reactive oxygen species in yeast or mammalian cell culture give rise to increased turnover of Fxn but not of other ISC synthesis proteins. We demonstrate that the mitochondrial Lon protease is involved in Fxn degradation and that iron export through the mitochondrial metal transporter Mmt1 protects yeast Fxn from degradation. We also determined that when FRDA fibroblasts were grown in media containing elevated iron, mitochondrial reactive oxygen species increased and Fxn decreased compared to WT fibroblasts. Furthermore, we screened a library of FDA-approved compounds and identified 38 compounds that increased yeast Fxn levels, including the azole bifonazole, antiparasitic fipronil, antitumor compound dibenzoylmethane, antihypertensive 4-hydroxychalcone, and a nonspecific anion channel inhibitor 4,4-diisothiocyanostilbene-2,2-sulfonic acid. We show that top hits 4-hydroxychalcone and dibenzoylmethane increased mRNA levels of transcription factor nuclear factor erythroid 2-related factor 2 in FRDA patient-derived fibroblasts, as well as downstream antioxidant targets thioredoxin, glutathione reductase, and superoxide dismutase 2. Taken together, these findings reveal that FRDA progression may be in part due to oxidant-mediated decreases in Fxn and that some approved compounds may be effective in increasing mitochondrial Fxn in FRDA, delaying disease progression.

Salidroside inhibits doxorubicin-induced cardiomyopathy by modulating a ferroptosis-dependent pathway

BACKGROUND

Doxorubicin-induced cardiotoxicity (DIC) limits the clinical application of the drug in treatment of cancers and imposes a severe health burden on the patients. Therefore, there is an urgent need to develop alternative therapeutic strategies or drugs to minimize DIC. Salidroside is a phenylpropanoid glycoside extracted from Rhodiola rosea with multiple biological effects such as anti-inflammation and antioxidant properties. However, its mechanism of action in DIC is still poorly understood.

PURPOSE

The present study was aimed to investigate the role of salidroside in DIC and associated mechanism of action for the described effects.

METHODS

Cardiac dysfunction was induced through treatment of mice with doxorubicin in vivo and in vitro. The mechanism of action of salidroside was investigated using western blot assay, qPCR, immunofluorescence, histochemistry, echocardiography, and high-content imaging system.

RESULTS

Results of the current study found that treatment of mice with salidroside significantly improved doxorubicin-induced cardiac dysfunction, ferroptosis-like cell damage, and fibrosis in vivo. Further, it was noted that salidroside inhibited ferroptosis in vivo and in vitro by limiting iron accumulation, restoring GPX4-dependent antioxidant capacity, and preventing lipid peroxidation at the cellular or mitochondrial levels. Mechanistically, salidroside inhibited DOX-induced mitochondrial ROS, Fe2+, and lipid peroxidation as well as restored mitochondrial membrane potential by promoting mitochondrial biogenesis, improving mitochondrial iron-sulfur clusters, and restoring mitochondrial OXPHOS complexes, thereby improving mitochondrial function. In addition, AMPK is a key protein that coordinates mitochondria, metabolism, and ferroptosis. Therefore, it was found that compound C (CC), an AMPK inhibitor, disrupted the regulation of cellular lipid metabolism and mitochondrial function of salidroside as well as led to failure of the protective effect of salidroside against ferroptotic cell death.

CONCLUSIONS

The present study evidently demonstrated the cardioprotective effects of salidroside against doxorubicin-induced cardiomyopathy. Further, salidroside markedly down-regulated ferroptotic cell death by activating AMPK-dependent signaling pathways including regulating abnormal fatty acid metabolism and maintaining mitochondrial function. Therefore, salidroside is can be exploited to develop a novel medication for clinical DIC and salidroside may represent a novel treatment that improves recovery from DIC by targeting ferroptosis.