Acetylcholinesterase inhibitor ameliorates doxorubicin-induced cardiotoxicity through reducing RIP1-mediated necroptosis

Chronic mitochondrial dynamic-targeted therapy alleviates left ventricular dysfunction by reducing multiple programmed cell death in post-myocardial infarction rats

Mitochondrial dysfunction and the activation of multiple programmed cell death (PCD) have been shown to aggravate the severity and mortality associated with the progression of myocardial infarction (MI). Although pharmacological modulation of mitochondrial dynamics, including treatment with the fusion promoter (M1) and the fission inhibitor (Mdivi-1), exerted cardioprotection against several cardiac complications, their roles in the post-MI model have never been investigated. Using a MI rat model instigated by permanent left-anterior descending (LAD) coronary artery occlusion, post-MI rats were randomly assigned to receive one of 4 treatments (n = 10/group): vehicle (DMSO 3%V/V), enalapril (10 mg/kg), Mdivi-1 (1.2 mg/kg) and M1 (2 mg/kg), while a control group of sham operated rats underwent surgery without LAD occlusion (n = 10). After 32-day treatment, cardiac and mitochondrial function, and histopathological morphology were investigated and molecular analysis was performed. Treatment with enalapril, Mdivi-1, and M1 significantly mitigated cardiac pathological remodeling, reduced myocardial injury, and improved left ventricular (LV) function in post-MI rats. Importantly, all interventions also attenuated mitochondrial dynamic imbalance and mitigated activation of apoptosis, necroptosis, and pyroptosis after MI. This investigation demonstrated for the first time that chronic mitochondrial dynamic-targeted therapy mitigated mitochondrial dysfunction and activation of PCD, leading to improved LV function in post-MI rats.

Donepezil ameliorates gut barrier disruption in doxorubicin-treated rats

An impact of donepezil against doxorubicin-induced gut barrier disruption and gut dysbiosis has never been investigated. Twenty-four male Wistar rats were divided into three groups. Each group was treated with either vehicle as a control, doxorubicin, or doxorubicin-cotreated with donepezil. Heart rate variability was assessed to reflect the impact of doxorubicin and donepezil. Then, animals were euthanized, and the ileum and its contents were collected in each case to investigate the gut barrier and gut microbiota, respectively. The microbiota-derived endotoxin, trimethylamine N-oxide (TMAO), and short-chain fatty acids (SCFAs) in the serum were determined. An increase in the sympathetic tone, endotoxins, and TMAO levels with disruption of the gut barrier and a decrease in SCFAs levels were observed in doxorubicin-treated rats. Gut microbiota of doxorubicin-treated rats was significantly different from that of the control group. Donepezil treatment significantly decreased the sympathetic tone, restored the gut barrier, and reduced endotoxin and TMAO levels in doxorubicin-treated rats. Nonetheless, donepezil administration did not alter the gut microbiota profile and levels of SCFAs in doxorubicin-treated rats. Doxorubicin impaired the autonomic balance and the gut barrier, and induced gut dysbiosis, resulting in gut toxicity. Donepezil partially improved the doxorubicin-induced gut toxicity through balancing the autonomic disturbance.

Donepezil and quercetin alleviate valproate-induced testicular oxidative stress, inflammation and apoptosis: Imperative roles of AMPK/SIRT1/ PGC-1α and p38-MAPK/NF-κB/ IL-1β signaling cascades

The mounting evidence of valproate-induced testicular damage in clinical settings is alarming, especially for men taking valproate (VPA) for long-term or at high doses. Both donepezil (DON) and quercetin (QUE) have promising antioxidant, anti-inflammatory, and anti-apoptotic effects. Therefore, this study aimed to determine whether DON, QUE, and their combination could mitigate VPA-induced testicular toxicity and unravel the mechanisms underlying their protective effect. In this study, male albino rats were randomly categorized into six equal groups: control, VPA (500 mg/kg, I.P., for 14 days), DON (3 and 5 mg/kg), QUE (50 mg/kg), and DON 3 + QUE combination groups. The DON and QUE treatments were administered orally for 7 consecutive days before VPA administration and then concomitantly with VPA for 14 days. VPA administration disrupted testicular function by altering testicular architecture, ultrastructure, reducing sperm count, viability, and serum testosterone levels. Additionally, VPA triggered oxidative damage, inflammatory, and apoptotic processes and suppressed the AMPK/SIRT1/PGC-1α signaling cascade. Pretreatment with DON, QUE, and their combination significantly alleviated histological and ultrastructure damage caused by VPA and increased the serum testosterone level, sperm count, and viability. They also suppressed the oxidative stress by reducing testicular MDA content and elevating SOD activity. In addition, they reduced the inflammatory response by suppressing IL-1β level, NF-κB, and the p38-MAPK expression as well as inhibiting apoptosis by diminishing caspase-3 and increasing Bcl-2 expression. These novel protective effects were mediated by upregulating AMPK/SIRT1/PGC-1α signaling cascade. In conclusion, these findings suggest that DON, QUE, and their combination possess potent protective effects against VPA-induced testicular toxicity.

Potential roles of 4HNE-adducted protein in serum extracellular vesicles as an early indicator of oxidative response against doxorubicin-induced cardiomyopathy in rats

Late-onset cardiomyopathy is becoming more common among cancer survivors, particularly those who received doxorubicin (DOXO) treatment. However, few clinically available cardiac biomarkers can predict an unfavorable cardiac outcome before cell death. Extracellular vesicles (EVs) are emerging as biomarkers for cardiovascular diseases and others. This study aimed to measure dynamic 4-hydroxynonenal (4HNE)-adducted protein levels in rats treated chronically with DOXO and examine their link with oxidative stress, antioxidant gene expression in cardiac tissues, and cardiac function. Twenty-two male Wistar rats were randomly assigned to receive intraperitoneal injection of normal saline (n = 8) or DOXO (3 mg/kg, 6 doses, n = 14). Before and after therapy, serum EVs and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were determined. Tunable resistive pulse sensing was used to measure EV size and concentration. ELISA was used to assess 4HNE-adducted protein in EVs and cardiac tissues. Differential-display reverse transcription-PCR was used to quantitate cardiac Cat and Gpx1 gene expression. Potential correlations between 4HNE-adducted protein levels in EVs, cardiac oxidative stress, antioxidant gene expression, and cardiac function were determined. DOXO-treated rats showed more serum EV 4HNE-adducted protein than NSS-treated rats at day 9 and later endpoints, whereas NT-proBNP levels were not different between groups. Moreover, on day 9, surviving rats' EVs had higher levels of 4HNE-adducted protein, and these correlated positively with concentrations of heart tissue 4HNE adduction and copy numbers of Cat and Gpx1, while at endpoint correlated negatively with cardiac functions. Therefore, 4HNE-adducted protein in serum EVs could be an early, minimally invasive biomarker of the oxidative response and cardiac function in DOXO-induced cardiomyopathy.

Vagus nerve stimulation and acetylcholinesterase inhibitor donepezil provide cardioprotection against trastuzumab-induced cardiotoxicity in rats by attenuating mitochondrial dysfunction

Trastuzumab (Trz) is a targeted anticancer drug for human epidermal growth factor receptor 2 (HER2)-positive tumors, as Trz-induced cardiotoxicity (TIC) is commonly observed in Trz-treated patients. Since cardiac autonomic modulation with electrical vagus nerve stimulation (VNS) and acetylcholinesterase (AChE) inhibitors exerts cardioprotection against various heart diseases, the comparative effects of electrical VNS and an AChE inhibitor (donepezil) on cardiac and mitochondrial functions and programmed cell death pathways in TIC are not known. VNS devices were implanted in thirty-two male Wistar rats and were divided into 4 groups: (i) Control-Sham (CSham), (ii) Trz-Sham (TSham), (iii) Trz-VNS (TVNS), and (iv) Trz-donepezil (TDPZ). Rats in the Trz-treated groups were intraperitoneally injected with Trz (4 mg/kg/day) for 7 days, while CSham rats were injected with NSS. VNS devices were activated in the TVNS rats during the 7-day Trz treatment, but not in the sham rats. Rats in the TDPZ group received donepezil orally (5 mg/kg/day) for 7 days. At the end, left ventricular (LV) function and heart rate variability were evaluated, and heart tissue was collected for biochemical and histological analysis. Trz rats showed LV dysfunction and cardiac sympathovagal imbalance. In addition, mitochondrial function and dynamics were impaired in TIC rats. Trz also increased cardiomyocyte death by inducing apoptosis, pyroptosis, and ferroptosis. Electrical VNS and donepezil had similar efficacy in alleviating cardiac mitochondrial dysfunction, dynamic imbalances, and cardiomyocyte death, leading to improved LV function. These findings suggested that parasympathetic activation via either VNS or an AChE inhibitor could be a promising therapeutic intervention against TIC.

Acetylcholinesterase inhibition protects against trastuzumab-induced cardiotoxicity through reducing multiple programmed cell death pathways

BACKGROUND

Trastuzumab (Trz)-induced cardiotoxicity (TIC) is one of the most common adverse effects of targeted anticancer agents. Although oxidative stress, inflammation, mitochondrial dysfunction, apoptosis, and ferroptosis have been identified as potential mechanisms underlying TIC, the roles of pyroptosis and necroptosis under TIC have never been investigated. It has been shown that inhibition of acetylcholinesterase function by using donepezil exerts protective effects in various heart diseases. However, it remains unknown whether donepezil exerts anti-cardiotoxic effects in rats with TIC. We hypothesized that donepezil reduces mitochondrial dysfunction, inflammation, oxidative stress, and cardiomyocyte death, leading to improved left ventricular (LV) function in rats with TIC.

METHODS

Male Wistar rats were randomly assigned to be Control or Trz groups (Trz 4 mg/kg/day, 7 days, I.P.). Rats in Trz groups were assigned to be co-treated with either drinking water (Trz group) or donepezil 5 mg/kg/day (Trz + DPZ group) via oral gavage for 7 days. Cardiac function, heart rate variability (HRV), and biochemical parameters were evaluated.

RESULTS

Trz-treated rats had impaired LV function, HRV, mitochondrial function, and increased inflammation and oxidative stress, leading to apoptosis, ferroptosis, and pyroptosis. Donepezil co-treatment effectively decreased those adverse effects of TIC, resulting in improved LV function. An in vitro study revealed that the cytoprotective effects of donepezil were abolished by a muscarinic acetylcholine receptor (mAChR) antagonist.

CONCLUSIONS

Donepezil exerted cardioprotection against TIC via attenuating mitochondrial dysfunction, oxidative stress, inflammation, and cardiomyocyte death, leading to improved LV function through mAChR activation. This suggests that donepezil could be a novel intervention strategy in TIC.

Effects of metformin and donepezil on the prevention of doxorubicin-induced cardiotoxicity in breast cancer: a randomized controlled trial

Doxorubicin (DOX) causes deleterious cardiotoxicity. We aimed to investigate the protective roles of metformin and donepezil against DOX-induced cardiotoxicity. In this randomized-controlled trial, 143 female breast cancer patients were enrolled. Metformin (n = 43), donepezil (n = 52), or placebo (n = 48) were prescribed during DOX treatment. The primary endpoint was a proportion of patients with high sensitivity troponin-I (hsTnI) more than the 99th percentile value (> 15.6 ng/L) after DOX treatment. The secondary outcomes were the changes in the hsTnI, N-terminal pro-B-type natriuretic peptide (NT-proBNP), left ventricular ejection fraction (LVEF), global longitudinal strain (GLS) and peripheral blood mononuclear cells analysis for mitochondrial respiration. Baseline characteristics were similar between the groups. The primary endpoint occurred in 58.54% of metformin group, 76.92% in donepezil group, and 69.77% in placebo group (p = 0.215). The level of hsTnI increased after receiving DOX with subsequent decline in LVEF and GLS. Metformin and donepezil did not attenuate hsTnI elevation, LVEF or GLS reduction. There was no significant change in NT-proBNP level. Mitochondrial respiratory dysfunction was observed in the placebo and donepezil groups. However, metformin preserved mitochondrial respiration during DOX therapy. In conclusion, co-treatment with metformin or donepezil did not prevent myocardial injury. Metformin had a favorable mitochondrial outcome and warranted future studies.

Oxytetracycline-induced oxidative liver damage by disturbed mitochondrial dynamics and impaired enzyme antioxidants in largemouth bass (Micropterus salmoides)

Oxytetracycline (OTC), a commonly used tetracycline antibiotic in aquaculture, has been found to cause significant damage to the liver of largemouth bass (Micropterus salmoides). This study revealed that OTC can lead to severe histopathological damage, structural changes at the cellular level, and increased levels of reactive oxygen species (ROS) in M. salmoides. Meanwhile, OTC impairs the activities of antioxidant enzyme (such as T-SOD, CAT, GST, GR) by suppressing the activation of MAPK/Nrf2 pathway. OTC disrupts mitochondrial dynamics and mitophagy through via PINK1/Parkin pathway. The accumulation of damaged mitochondria, combined with the inhibition of the antioxidant enzyme system, contributes to elevated ROS levels and oxidative liver damage in M. salmoides. Further investigations demonstrated that an enzyme-treated soy protein (ETSP) dietary supplement can help maintain mitochondrial dynamic balance by inhibiting the PINK1/Parkin pathway and activate the MAPK/Nrf2 pathway to counteract oxidative damage. In summary, these findings highlight that exposure to OTC disrupts mitochondrial dynamics and inhibits the antioxidant enzyme system, ultimately exacerbating oxidative liver damage in M. salmoides. We propose the use of a dietary supplement as a preventive measure against OTC-related side effects, providing valuable insights into the mechanisms of antibiotic toxicity in aquatic environments.

Recent Advances in Mitochondrial Fission/Fusion-Targeted Therapy in Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX) has been recognized as one of the most effective chemotherapies and extensively used in the clinical settings of human cancer. However, DOX-mediated cardiotoxicity is known to compromise the clinical effectiveness of chemotherapy, resulting in cardiomyopathy and heart failure. Recently, accumulation of dysfunctional mitochondria via alteration of the mitochondrial fission/fusion dynamic processes has been identified as a potential mechanism underlying DOX cardiotoxicity. DOX-induced excessive fission in conjunction with impaired fusion could severely promote mitochondrial fragmentation and cardiomyocyte death, while modulation of mitochondrial dynamic proteins using either fission inhibitors (e.g., Mdivi-1) or fusion promoters (e.g., M1) can provide cardioprotection against DOX-induced cardiotoxicity. In this review, we focus particularly on the roles of mitochondrial dynamic pathways and the current advanced therapies in mitochondrial dynamics-targeted anti-cardiotoxicity of DOX. This review summarizes all the novel insights into the development of anti-cardiotoxic effects of DOX via the targeting of mitochondrial dynamic pathways, thereby encouraging and guiding future clinical investigations to focus on the potential application of mitochondrial dynamic modulators in the setting of DOX-induced cardiotoxicity.

Demonstration of doxorubicin's cardiotoxicity and screening using a 3D bioprinted spheroidal droplet-based system

Doxorubicin (DOX) is a highly effective anthracycline chemotherapy agent effective in treating a broad range of life-threatening malignancies but it causes cardiotoxicity in many subjects. While the mechanism of its cardiotoxic effects remains elusive, DOX-related cardiotoxicity can lead to heart failure in patients. In this study, we investigated the effects of DOX-induced cardiotoxicity on human cardiomyocytes (CMs) using a three-dimensional (3D) bioprinted cardiac spheroidal droplet based-system in comparison with the traditional two-dimensional cell (2D) culture model. The effects of DOX were alleviated with the addition of N-acetylcysteine (NAC) and Tiron. Caspase-3 activity was quantified, and reactive oxygen species (ROS) production was measured using dihydroethidium (DHE) staining. Application of varying concentrations of DOX (0.4 μM-1 μM) to CMs revealed a dose-specific response, with 1 μM concentration imposing maximum cytotoxicity and 0.22 ± 0.11% of viable cells in 3D samples versus 1.02 ± 0.28% viable cells in 2D cultures, after 5 days of culture. Moreover, a flow cytometric analysis study was conducted to study CMs proliferation in the presence of DOX and antioxidants. Our data support the use of a 3D bioprinted cardiac spheroidal droplet as a robust and high-throughput screening model for drug toxicity. In the future, this 3D spheroidal droplet model can be adopted as a human-derived tissue-engineered equivalent to address challenges in other various aspects of biomedical pre-clinical research.

Structures and Anti-Allergic Activities of Natural Products from Marine Organisms

In recent years, allergic diseases have occurred frequently, affecting more than 20% of the global population. The current first-line treatment of anti-allergic drugs mainly includes topical corticosteroids, as well as adjuvant treatment of antihistamine drugs, which have adverse side effects and drug resistance after long-term use. Therefore, it is essential to find alternative anti-allergic agents from natural products. High pressure, low temperature, and low/lack of light lead to highly functionalized and diverse functional natural products in the marine environment. This review summarizes the information on anti-allergic secondary metabolites with a variety of chemical structures such as polyphenols, alkaloids, terpenoids, steroids, and peptides, obtained mainly from fungi, bacteria, macroalgae, sponges, mollusks, and fish. Molecular docking simulation is applied by MOE to further reveal the potential mechanism for some representative marine anti-allergic natural products to target the H1 receptor. This review may not only provide insight into information about the structures and anti-allergic activities of natural products from marine organisms but also provides a valuable reference for marine natural products with immunomodulatory activities.

Blood metabolomes as non-invasive biomarkers and targets of metabolic interventions for doxorubicin and trastuzumab-induced cardiotoxicity

This study aimed to identify the alterations of blood metabolome levels and their association with cardiac dysfunction and cardiac injury following treatment with doxorubicin and trastuzumab. Eight-week-old male Wistar rats were divided into four groups (n = 6 per group) to receive intraperitoneal injection with either: (1) 1 mL of normal saline solution (NSS) at days 0, 4, 8, 15, 22, and 29 (control group for doxorubicin); (2) 3 mg/kg/day of doxorubicin at days 0, 4, 8, 15, 22, and 29 (doxorubicin group); (3) 1 mL of NSS at days 0-6 (control group for trastuzumab); or (4) 4 mg/kg/day of trastuzumab at days 0-6 (trastuzumab group). Four days after the last injected dose, cardiac function was determined. The rats were then euthanized to collect venous blood and the heart for the quantification of 107 serum and 100 cardiac metabolomes using mass spectrometry-based targeted metabolomics. We observed strong relationships between 72 cardiac versus 61 serum metabolomes in doxorubicin and trastuzumab groups. Moreover, significant correlations between cardiac function and the cardiac injury biomarker versus 28 and 58 serum metabolomes were revealed in doxorubicin and trastuzumab-treated rats, respectively. Interestingly, the patterns of both serum and cardiac metabolome alterations differed between doxorubicin and trastuzumab groups. Our findings emphasize the potential role of the constituents of the blood metabolome as non-invasive biomarkers to assess severity and prognosis of heart failure induced by doxorubicin and trastuzumab. These findings may contribute to the development of metabolic-targeted therapy specific for cardioprotection during different phases of cancer treatment.

GSDMD-mediated pyroptosis dominantly promotes left ventricular remodeling and dysfunction in post-myocardial infarction: a comparison across modes of programmed cell death and mitochondrial involvement

BACKGROUND

Myocardial infarction (MI) has recently accounted for more than one-third of global mortality. Multiple molecular pathological pathways, such as oxidative stress, inflammation, and mitochondrial dysfunction, have been recognized as possible mechanisms in the development of MI. Furthermore, different phases of ischemic injury following the progression of MI were also associated with multiple types of programmed cell death (PCDs), including apoptosis, necroptosis, ferroptosis, and pyroptosis. However, it remains unknown whether which types of PCDs play the most dominant role in post-myocardial infarction (post-MI).

METHOD

In this study, we used a preclinical rat model of MI induced by permanent left anterior descending coronary artery (LAD) ligation (n = 6) or a sham operated rat model (n = 6). After a 5-week experiment, cardiac function and morphology, mitochondrial studies, and molecular signaling analysis of PCDs were determined.

RESULTS

Herein, we demonstrated that post-MI rats had considerably impaired cardiac geometry, increased oxidative stress, myocardial injuries, and subsequently contractile dysfunction. They also exhibited worsened cardiac mitochondrial function and dynamic imbalance. More importantly, we found that post-MI mediated abundant myocardial cell death through multiple PCDs, including apoptosis, necroptosis, and pyroptosis, but not ferroptosis.

CONCLUSION

In this study, we provide the first insights into the mechanism of PCDs by pyroptosis, which is leveraged as the most dominant mode of cell death after MI.

Mitochondrial quality control mechanisms as therapeutic targets in doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) is a chemotherapeutic drug that is utilized for solid tumors and hematologic malignancies, but its clinical application is hampered by life-threatening cardiotoxicity including cardiac dilation and heart failure. Mitochondrial quality control processes, including mitochondrial proteostasis, mitophagy, and mitochondrial dynamics and biogenesis, serve to maintain mitochondrial homeostasis in the cardiovascular system. Importantly, recent advances have unveiled a major role for defective mitochondrial quality control in the etiology of DOX cardiomyopathy. Moreover, specific interventions targeting these quality control mechanisms to preserve mitochondrial function have emerged as potential therapeutic strategies to attenuate DOX cardiotoxicity. However, clinical translation is challenging because of obscure mechanisms of action and potential adverse effects. The purpose of this review is to provide new insights regarding the role of mitochondrial quality control in the pathogenesis of DOX cardiotoxicity, and to explore promising therapeutic approaches targeting these mechanisms to aid clinical management.

Vagus nerve stimulation exerts cardioprotection against doxorubicin-induced cardiotoxicity through inhibition of programmed cell death pathways

The aberration of programmed cell death including cell death associated with autophagy/mitophagy, apoptosis, necroptosis, pyroptosis, and ferroptosis can be observed in the development and progression of doxorubicin-induced cardiotoxicity (DIC). Vagus nerve stimulation (VNS) has been shown to exert cardioprotection against cardiomyocyte death through the release of the neurotransmitter acetylcholine (ACh) under a variety of pathological conditions. However, the roles of VNS and its underlying mechanisms against DIC have never been investigated. Forty adults male Wistar rats were divided into 5 experimental groups: (i) control without VNS (CSham) group, (ii) doxorubicin (3 mg/kg/day, i.p.) without VNS (DSham) group, (iii) doxorubicin + VNS (DVNS) group, (iv) doxorubicin + VNS + mAChR antagonist (atropine; 1 mg/kg/day, ip, DVNS + Atro) group, and (v) doxorubicin + VNS + nAChR antagonist (mecamylamine; 7.5 mg/kg/day, ip, DVNS + Mec) group. Our results showed that doxorubicin insult led to left ventricular (LV) dysfunction through impaired cardiac autonomic balance, decreased mitochondrial function, imbalanced mitochondrial dynamics, and exacerbated cardiomyocyte death including autophagy/mitophagy, apoptosis, necroptosis, pyroptosis, and ferroptosis. However, VNS treatment improved cardiac mitochondrial and autonomic functions, and suppressed excessive autophagy, apoptosis, necroptosis, pyroptosis, and ferroptosis, leading to improved LV function. Consistent with this, ACh effectively improved cell viability and suppressed cell cytotoxicity in doxorubicin-treated H9c2 cells. In contrast, either inhibitors of muscarinic (mAChR) or nicotinic acetylcholine receptor (nAChR) completely abrogated the favorable effects mediated by VNS and acetylcholine. These findings suggest that VNS exerts cardioprotective effects against doxorubicin-induced cardiomyocyte death via activation of both mAChR and nAChR.

The SPATA2/CYLD pathway contributes to doxorubicin-induced cardiomyocyte ferroptosis via enhancing ferritinophagy

Ferroptosis is an iron-dependent cell death and contributes to doxorubicin-induced cardiotoxicity, but the mechanisms behind intracellular iron overload in cardiomyocyte after administration of doxorubicin remain largely unknown. Ferritinophagy is a selective type of autophagy and could be a novel source for intracellular free iron. Spermatogenesis-associated protein 2 (SPATA2), a member of the TNF signaling pathway, can recruit cylindromatosis (CYLD, a deubiquitinating enzyme) to regulate cell death. This study aims to explore whether ferritinophagy is the source for intracellular iron overload in cardiomyocyte upon doxorubicin treatment and whether the SPATA2/CYLD pathway is involved in regulation of nuclear receptor coactivator 4 (NCOA4) level, the selective cargo receptor for ferritinophagy. The C57BL/6J mice were subjected to a single injection of doxorubicin, which showed the compromised cardiac functions, accompanied by the upregulation of SPATA2 and CYLD and the enhanced interaction between them, the increases in ferritinophagy (reflecting by increases in NCOA4 and ratio of LC3Ⅱ/LC3Ⅰ while decreases in NCOA4 ubiquitination and ferritin) and ferroptosis (reflecting by intracellular iron overload and increase of acyl-CoA synthetase long chain family member 4). Consistently, similar results were achieved in the cultured cardiomyocytes after incubation with doxorubicin. Knocked down of SPATA2 notably reduced doxorubicin-induced cardiomyocyte injury concomitant with the attenuated ferritinophagy and the decreased ferroptosis. Based on these observations, we conclude that a novel pathway of SPATA2/CYLD has been identified, which contributes to doxorubicin-induced cardiomyocyte ferroptosis via enhancing ferritinophagy through a mechanism involving the deubiquitination of NCOA4.

Puerarin activates adaptive autophagy and protects the myocardium against doxorubicin-induced cardiotoxicity via the 14–3-3γ/PKCε pathway

Doxorubicin (Dox)-induced cardiotoxicity (DIC) seriously threatens the health of related patients. Studies have confirmed that 14-3-3γ and protein kinase C epsilon (PKCε) are the endogenous protective proteins. Puerarin (Pue) is a bioactive ingredient isolated from the root of Pueraria lobata. It possesses many pharmacological properties, which have been widely used in treating and adjuvant therapy of cardiovascular diseases. In the study, we intended to explore the effects and mechanism of Pue pretreatment to protect the myocardium against DIC injury. Adult mice and H9c2 cells were pretreated with Pue, and the injury model was made with Dox. Results showed that Pue pretreatment alleviated DIC injury, as revealed by increased cell viability, decreased LDH activity and apoptosis, inhibited excess oxidative stress, maintained mitochondrial function and energy metabolism, and improved myocardial function. Furthermore, Pue pretreatment upregulated 14-3-3γ expression, interacted with PKCε, phosphorylated and impelled migration to mitochondria, activated adaptive autophagy, and protected the myocardium. However, pAD/14-3-3γ-shRNA or εV1-2 (a PKCε activity inhibitor) or 3-methyladenine (an autophagy inhibitor) could weaken the above effects of Pue pretreatment. Together, Pue pretreatment could activate adaptive autophagy by the 14-3-3γ/PKCε pathway and protect the myocardium against DIC injury.

Panax notoginseng Saponins Protect Brain Microvascular Endothelial Cells against Oxygen-Glucose Deprivation/Resupply-Induced Necroptosis via Suppression of RIP1-RIP3-MLKL Signaling Pathway

Recently, necroptosis has emerged as one of the important mechanisms of ischemia stroke. Necroptosis can be rapidly activated in endothelial cells to cause vascular damage and neuroinflammation. Panax notoginseng saponins (PNS), an ingredient extracted from the root of Panax notoginseng (Burk.) F.H. Chen, was commonly used for ischemic stroke, while its molecular mechanism and targets have not been fully clarified. Our study aimed to clarify the anti-necroptosis effect of PNS by regulating RIP1-RIP3-MLKL signaling pathway in brain microvascular endothelial cells (BMECs) subjected to transient oxygen-glucose deprivation (OGD/resupply [R]). In vitro, the necroptosis model of rat BMECs was established by testing the effect of OGD/R in the presence of the pan-caspase inhibitor z-VAD-FMK. After administration of PNS and Nec-1, cell viability, cell death modality, the expression of RIP1-RIP3-MLKL pathway and mitochondrial membrane potential (Δψm) level were investigated in BMECs upon OGD/R injury. The results showed that PNS significantly enhanced cell viability of BMECs determined by CCK-8 analysis, and protected BMECs from necroptosis by Flow cytometry and TEM. In addition, PNS inhibited the phosphorylation of RIP1, RIP3, MLKL and the downstream expression of PGAM5 and Drp1, while similar results were observed in Nec-1 intervention. We further investigated whether PNS prevented the Δψm depolarization. Our current findings showed that PNS effectively reduced the occurrence of necroptosis in BMECs exposed to OGD/R by inhibition of the RIP1-RIP3-MLK signaling pathway and mitigation of mitochondrial damage. This study provided a novel insight of PNS application in clinics.

Ranolazine alleviated cardiac/brain dysfunction in doxorubicin-treated rats

Doxorubicin (Dox), a powerful chemotherapeutic agent, has been shown to cause cardiotoxicity and neurotoxicity. Ranolazine, a drug that is commonly used to treat patients with chronic angina, has been shown to reduce toxicity from Dox therapy. Therefore, the present study aims to investigate the mechanisms behind the protective effects of ranolazine on the heart and brain in Dox-treatment. Twenty-four male Wistar rats received 6 doses of either 0.9% normal saline (0.9% NSS, i.p., n = 8) or Dox (3 mg/kg, i.p., n = 16). All Dox-treated rats were assigned into 2 groups to receive vehicle (0.9% NSS, orally; n = 8) or ranolazine (305 mg/kg/day, orally; n = 8) for 30 consecutive days. Following the treatments, left ventricular (LV) function and cognition were determined. Animals were euthanized, then the heart and brain were collected for further analysis. Dox induced systemic oxidative stress/inflammation, and cardiac injury evidenced by mitochondrial dysfunction, mitochondrial dynamic imbalance, and apoptosis, resulting in LV dysfunction. Ranolazine significantly improved LV function via attenuating cardiac injury. Dox also caused brain pathologies as indicated by increased brain inflammation, impaired blood-brain barrier integrity, brain mitochondrial dysfunction, microglial dysmorphology, hippocampal dysplasticity, and increased apoptosis, resulting in cognitive decline. Ranolazine exerted neuroprotective effects by suppressing brain pathologies and restoring cognitive function. These findings suggest that ranolazine has a potential role in cardio- and neuro-protection against chemotherapy.

Paeonol protects against doxorubicin-induced cardiotoxicity by promoting Mfn2-mediated mitochondrial fusion through activating the PKCε-Stat3 pathway

INTRODUCTION

The anti-cancer medication doxorubicin (Dox) is largely restricted in clinical usage due to its significant cardiotoxicity. The only medication approved by the FDA for Dox-induced cardiotoxicity is dexrazoxane, while it may reduce the sensitivity of cancer cells to chemotherapy and is restricted for use. There is an urgent need for the development of safe and effective medicines to alleviate Dox-induced cardiotoxicity.

OBJECTIVES

The objective of this study was to determine whether Paeonol (Pae) has the ability to protect against Dox-induced cardiotoxicity and if so, what are the underlying mechanisms involved.

METHODS

Sprague-Dawley rats and primary cardiomyocytes were used to create Dox-induced cardiotoxicity models. Pae's effects on myocardial damage, mitochondrial function, mitochondrial dynamics and signaling pathways were studied using a range of experimental methods.

RESULTS

Pae enhanced Mfn2-mediated mitochondrial fusion, restored mitochondrial function and cardiac performance both in vivo and in vitro under the Dox conditions. The protective properties of Pae were blunted when Mfn2 was knocked down or knocked out in Dox-induced cardiomyocytes and hearts respectively. Mechanistically, Pae promoted Mfn2-mediated mitochondria fusion by activating the transcription factor Stat3, which bound to the Mfn2 promoter in a direct manner and up-regulated its transcriptional expression. Furthermore, molecular docking, surface plasmon resonance and co-immunoprecipitation studies showed that Pae's direct target was PKCε, which interacted with Stat3 and enabled its phosphorylation and activation. Pae-induced Stat3 phosphorylation and Mfn2-mediated mitochondrial fusion were inhibited when PKCε was knocked down. Furthermore, Pae did not interfere with Dox's antitumor efficacy in several tumor cells.

CONCLUSION

Pae protects the heart against Dox-induced damage by stimulating mitochondrial fusion via the PKCε-Stat3-Mfn2 pathway, indicating that Pae might be a promising therapeutic therapy for Dox-induced cardiotoxicity while maintaining Dox's anticancer activity.

Assessing Drug-Induced Mitochondrial Toxicity in Cardiomyocytes: Implications for Preclinical Cardiac Safety Evaluation

Drug-induced cardiotoxicity not only leads to the attrition of drugs during development, but also contributes to the high morbidity and mortality rates of cardiovascular diseases. Comprehensive testing for proarrhythmic risks of drugs has been applied in preclinical cardiac safety assessment for over 15 years. However, other mechanisms of cardiac toxicity have not received such attention. Of them, mitochondrial impairment is a common form of cardiotoxicity and is known to account for over half of cardiovascular adverse-event-related black box warnings imposed by the U.S. Food and Drug Administration. Although it has been studied in great depth, mitochondrial toxicity assessment has not yet been incorporated into routine safety tests for cardiotoxicity at the preclinical stage. This review discusses the main characteristics of mitochondria in cardiomyocytes, drug-induced mitochondrial toxicities, and high-throughput screening strategies for cardiomyocytes, as well as their proposed integration into preclinical safety pharmacology. We emphasize the advantages of using adult human primary cardiomyocytes for the evaluation of mitochondrial morphology and function, and the need for a novel cardiac safety testing platform integrating mitochondrial toxicity and proarrhythmic risk assessments in cardiac safety evaluation.

Promoting mitochondrial fusion in doxorubicin-induced cardiotoxicity: a novel therapeutic target for cardioprotection

Changes in mitochondrial dynamics have been recognized as being one of the mechanisms related to cardiotoxicity following a high cumulative dose of doxorubicin (DOX).  A mitochondrial division inhibitor (Mdivi-1) and fusion promoter (M1) have been shown to be cardioprotective in a variety of cardiovascular settings, however their anti-cardiotoxic efficacy against DOX therapy remains unclear.  We therefore investigated whether treatment with Mdivi-1 and M1 protect the heart against DOX-induced cardiotoxicity via mitochondria-targeted pathways.  Male Wistar rats (n=40) received DOX (3 mg/kg, 6 doses, n=32) or 3% DMSO in the normal saline solution (NSS) (n=8) as a control.  DOX-injected rats were given one of four treatments beginning with the first DOX injection via intraperitoneal injection: 1) 3% DMSO in NSS (n=8), 2) Mdivi-1 (1.2 mg/kg/day, n=8), 3) M1 (2 mg/kg/day, n=8), and 4) Mdivi-1+M1 (n=8) for 30 days.  Cardiac function, mitochondrial function, oxidative stress, myocardial injury, and protein expression associated with inflammation, autophagy, mitophagy, apoptosis and mitochondrial dynamics were determined.  DOX caused a significant deterioration in mitochondrial function and dynamic regulation, and an increase in markers of oxidative stress, inflammation, myocardial injury, apoptosis, autophagy, and mitophagy, resulting in impaired cardiac function.  Co-treatment of DOX with Mdivi-1, M1, or a combination of the two mitigated these detrimental effects of DOX.  These findings imply that either inhibiting fission or promoting fusion of mitochondria protects the heart from DOX-induced myocardial damage.  Modulation of mitochondrial dynamics could be a novel therapeutic target in alleviating DOX-induced cytotoxic effects without compromising its anti-cancer efficacy.

Protective effects of necrostatin-1 on doxorubicin-induced cardiotoxicity in rat heart

Background: Doxorubicin (Dox) is one of the most effective antineoplastic drugs which has severe cardiotoxic effects, limiting its clinical usage. Though the exact mechanism of doxorubicin-induced cardiotoxicity is yet to be elucidated, it is shown that production of reactive oxygen species (ROS) increases oxidative stress and leads to cardiomyocyte apoptosis and necroptosis which is also defined as a programmed cell death.Purpose: In the present study, we investigate the effects of necrostatin-1 (Nec-1)-an inhibitor of receptor interaction proteins 1 (RIP1) and necroptosis-on doxorubicin-induced cardiotoxicity in rats.Research Design: Hearts were isolated and perfused by the Langendorff system in all four groups. Perfusion pressure (PP), left ventricular developed pressure (LVDP) and heart rate per minute (HR), LV (dP/dt) max, and LV (dP/dt) min which shows cardiac contractility and relaxation were recorded.Results: Results showed that PP significantly increased with Dox treatment and significantly decreased with Nec-1 treatment, while HR, LVDP, LV (dP/dt) max, and LV (dP/dt) min values significantly decreased with the Dox-treated group and significantly increased with Nec-1 treatment. Also with Nec-1 treatment, gene expression levels of anti-apoptotic Bcl-2 significantly increased and pro-apoptotic protein Bax, apoptotic marker caspase-3, and Nox-2 significantly decreased compared to the Dox-treated group. In heart tissues, MDA levels were significantly increased with Dox and decreased with Nec-1 treatment. These results were supported by the histological analysis indicated that Nec-1 reduced doxorubicin-induced cellular injury.Conclusions: In conclusion, our data indicate that Nec-1 ameliorates doxorubicin-induced cardiotoxicity by reducing oxidative stress injury and attenuating apoptosis and necroptosis.