Drug-induced mitochondrial dysfunction and cardiotoxicity

Lithium Treatment Induces Cardiac Dysfunction in Mice

Lithium (Li) salts are commonly used as medications for bipolar disorders. In addition to its therapeutic value, Li is also being increasingly used as a battery component in modern electronic devices. Concerns about its toxicity and negative impact on the heart have recently been raised. We investigated the effects of long-term Li treatment on the heart, liver, and kidney in mice. Sixteen C57BL/6J mice were randomly assigned to receive oral administration of Li carbonate (n = 8) or act as a control group (n = 8) for 12 weeks. We evaluated the cardiac electrical activity, morphology and function, and pathways contributing to remodelling. We assessed the multi-organ toxicity using histopathology techniques in the heart, liver, and kidney. Our findings suggest that mice receiving Li had impaired systolic function and ventricular repolarisation and were more susceptible to arrhythmias under adrenergic stimulation. The Li treatment caused an increase in the cardiomyocytes' size, the modulation of the extracellular signal-regulated kinase (ERK) pathway, along with some minor tissue damage. Our findings revealed a cardiotoxic effect of Li at therapeutic dosage, along with some histopathological alterations in the liver and kidney. In addition, our study suggests that our model could be used to test potential treatments for Li-induced cardiotoxicity.

Insights into Drug Cardiotoxicity from Biological and Chemical Data: The First Public Classifiers for FDA DICTrank

Drug-induced cardiotoxicity (DICT) is a major concern in drug development, accounting for 10-14% of postmarket withdrawals. In this study, we explored the capabilities of various chemical and biological data to predict cardiotoxicity, using the recently released Drug-Induced Cardiotoxicity Rank (DICTrank) dataset from the United States FDA. We analyzed a diverse set of data sources, including physicochemical properties, annotated mechanisms of action (MOA), Cell Painting, Gene Expression, and more, to identify indications of cardiotoxicity. We found that such data, including protein targets, especially those related to ion channels (such as hERG), physicochemical properties (such as electrotopological state) as well as peak concentration in plasma offer strong predictive ability as well as valuable insights into DICT. We also found compounds annotated with particular mechanisms of action, such as cyclooxygenase inhibition, could distinguish between most-concern and no-concern DICT compounds. Cell Painting features related to ER stress discern the most-concern cardiotoxic compounds from non-toxic compounds. While models based on physicochemical properties currently provide substantial predictive accuracy (AUCPR = 0.93), this study also underscores the potential benefits of incorporating more comprehensive biological data in future DICT predictive models. With the availability of - omics data in the future, using biological data promises enhanced predictability and delivers deeper mechanistic insights, paving the way for safer therapeutic drug development. All models and data used in this study are publicly released at https://broad.io/DICTrank_Predictor.

Acute and Sub-Chronic Intraperitoneal Toxicity Studies of the Elsholtzia ciliata Herbal Extract in Balb/c Mice

Elsholtzia ciliata essential oil (E. ciliata) has been reported to have an impact on the cardiovascular system. However, its toxicity remains unknown. Therefore, the objective of this investigation was to evaluate the toxicological aspects of the E. ciliata extract. Male Balb/c mice were subjected to either acute (a single dose administered for 24 h) or sub-chronic (daily dose for 60 days) intraperitoneal injections of the E. ciliata extract. The mice were assessed for blood hematological/biochemical profiles, mitochondrial functions, and histopathological changes. Additionally, in vitro cytotoxicity assessments of the E. ciliata extract were performed on immobilized primate kidney cells (MARC-145, Vero) and rat liver cells (WBF344) to evaluate cell viability. The control groups received an equivalent volume of olive oil or saline. Our results demonstrated no significant detrimental effects on hematological and biochemical parameters, mitochondrial functions, cellular cytotoxicity, or pathological alterations in vital organs following the intraperitoneal administration of the E. ciliata extract over the 60-day sub-chronic toxicity study. In general, E. ciliata displayed no indications of toxicity, suggesting that the E. ciliata extract is a safe natural product with a well-defined therapeutic and protective index (found to be 90 and 54, respectively) in Balb/c mice.

Subcellular Effectors of Cocaine Cardiotoxicity: All Roads Lead to Mitochondria-A Systematic Review of the Literature

Cocaine abuse is a serious public health problem as this drug exerts a plethora of functional and histopathological changes that potentially lead to death. Cocaine causes complex multiorgan toxicity, including in the heart where the blockade of the sodium channels causes increased catecholamine levels and alteration in calcium homeostasis, thus inducing an increased oxygen demand. Moreover, there is evidence to suggest that mitochondria alterations play a crucial role in the development of cocaine cardiotoxicity. We performed a systematic review according to the Preferred Reporting Items for Systemic Reviews and Meta-Analysis (PRISMA) scheme to evaluate the mitochondrial mechanisms determining cocaine cardiotoxicity. Among the initial 106 articles from the Pubmed database and the 17 articles identified through citation searching, 14 final relevant studies were extensively reviewed. Thirteen articles included animal models and reported the alteration of specific mitochondria-dependent mechanisms such as reduced energy production, imbalance of membrane potential, increased oxidative stress, and promotion of apoptosis. However, only one study evaluated human cocaine overdose samples and observed the role of cocaine in oxidative stress and the induction of apoptosis though mitochondria. Understanding the complex processes mediated by mitochondria through forensic analysis and experimental models is crucial for identifying potential therapeutic targets to mitigate or reverse cocaine cardiotoxicity in humans.

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.

Adverse effect propensity: A new feature of Gulf War illness predicted by environmental exposures

A third of 1990-1 Gulf-deployed personnel developed drug/chemical-induced multisymptom illness, "Gulf War illness" (GWI). Veterans with GWI (VGWI) report increased drug/exposure adverse effects (AEs). Using previously collected data from a case-control study, we evaluated whether the fraction of exposures that engendered AEs ("AE Propensity") is increased in VGWI (it was); whether AE Propensity is related to self-rated "chemical sensitivity" (it did); and whether specific exposures "predicted" AE Propensity (they did). Pesticides and radiation exposure were significant predictors, with copper significantly "protective"-in the total sample (adjusted for GWI-status) and separately in VGWI and controls, on multivariable regression. Mitochondrial impairment and oxidative stress (OS) underlie AEs from many exposures irrespective of nominal specific mechanism. We hypothesize that mitochondrial toxicity and interrelated OS from pesticides and radiation position people on the steep part of the curve of mitochondrial impairment and OS versus symptom/biological disruption, amplifying impact of new exposures. Copper, meanwhile, is involved in critical OS detoxification processes.

Simultaneously discovering the fate and biochemical effects of pharmaceuticals through untargeted metabolomics

Untargeted metabolomics is an established approach in toxicology for characterising endogenous metabolic responses to xenobiotic exposure. Detecting the xenobiotic and its biotransformation products as part of the metabolomics analysis provides an opportunity to simultaneously gain deep insights into its fate and metabolism, and to associate the internal relative dose directly with endogenous metabolic responses. This integration of untargeted exposure and response measurements into a single assay has yet to be fully demonstrated. Here we assemble a workflow to discover and analyse pharmaceutical-related measurements from routine untargeted UHPLC-MS metabolomics datasets, derived from in vivo (rat plasma and cardiac tissue, and human plasma) and in vitro (human cardiomyocytes) studies that were principally designed to investigate endogenous metabolic responses to drug exposure. Our findings clearly demonstrate how untargeted metabolomics can discover extensive biotransformation maps, temporally-changing relative systemic exposure, and direct associations of endogenous biochemical responses to the internal dose.

Targeting mitochondrial dynamics proteins for the treatment of doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) is an extensively used chemotherapeutic agent that can cause severe and frequent cardiotoxicity, which limits its clinical application. Although there have been extensive researches on the cardiotoxicity caused by DOX, there is still a lack of effective treatment. It is necessary to understand the molecular mechanism of DOX-induced cardiotoxicity and search for new therapeutic targets which do not sacrifice their anticancer effects. Mitochondria are considered to be the main target of cardiotoxicity caused by DOX. The imbalance of mitochondrial dynamics characterized by increased mitochondrial fission and inhibited mitochondrial fusion is often reported in DOX-induced cardiotoxicity, which can result in excessive ROS production, energy metabolism disorders, cell apoptosis, and various other problems. Also, mitochondrial dynamics disorder is related to tumorigenesis. Surprisingly, recent studies show that targeting mitochondrial dynamics proteins such as DRP1 and MFN2 can not only defend against DOX-induced cardiotoxicity but also enhance or not impair the anticancer effect. Herein, we summarize mitochondrial dynamics disorder in DOX-induced cardiac injury. Furthermore, we provide an overview of current pharmacological and non-pharmacological interventions targeting proteins involved in mitochondrial dynamics to alleviate cardiac damage caused by DOX.

Mitochondrial Dysfunction in Cardiotoxicity Induced by BCR-ABL1 Tyrosine Kinase Inhibitors -Underlying Mechanisms, Detection, Potential Therapies

The advent of BCR-ABL tyrosine kinase inhibitors (TKIs) targeted therapy revolutionized the treatment of chronic myeloid leukemia (CML) patients. Mitochondria are the key organelles for the maintenance of myocardial tissue homeostasis. However, cardiotoxicity associated with BCR-ABL1 TKIs can directly or indirectly cause mitochondrial damage and dysfunction, playing a pivotal role in cardiomyocytes homeostatic system and putting the cancer survivors at higher risk. In this review, we summarize the cardiotoxicity caused by BCR-ABL1 TKIs and the underlying mechanisms, which contribute dominantly to the damage of mitochondrial structure and dysfunction: endoplasmic reticulum (ER) stress, mitochondrial stress, damage of myocardial cell mitochondrial respiratory chain, increased production of mitochondrial reactive oxygen species (ROS), and other kinases and other potential mechanisms of cardiotoxicity induced by BCR-ABL1 TKIs. Furthermore, detection and management of BCR-ABL1 TKIs will promote our rational use, and cardioprotection strategies based on mitochondria will improve our understanding of the cardiotoxicity from a mitochondrial perspective. Ultimately, we hope shed light on clinical decision-making. By integrate and learn from both research and practice, we will endeavor to minimize the mitochondria-mediated cardiotoxicity and reduce the adverse sequelae associated with BCR-ABL1 TKIs.

Sex and age differences in AMPK phosphorylation, mitochondrial homeostasis, and inflammation in hearts from inflammatory cardiomyopathy patients

Linked to exacerbated inflammation, myocarditis is a cardiovascular disease, which may lead to dilated cardiomyopathy. Although sex and age differences in the development of chronic myocarditis have been postulated, underlying cellular mechanisms remain poorly understood. In the current study, we aimed to investigate sex and age differences in mitochondrial homeostasis, inflammation, and cellular senescence. Cardiac tissue samples from younger and older patients with inflammatory dilated cardiomyopathy (DCMI) were used. The expression of Sirt1, phosphorylated AMPK, PGC-1α, Sirt3, acetylated SOD2, catalase, and several mitochondrial genes was analyzed to assess mitochondrial homeostasis. The expression of NF-κB, TLR4, and interleukins was used to examine the inflammatory state in the heart. Finally, several senescence markers and telomere length were investigated. Cardiac AMPK expression and phosphorylation were significantly elevated in male DCMI patients, whereas Sirt1 expression remained unchanged in all groups investigated. AMPK upregulation was accompanied by a preserved expression of all mitochondrial proteins/genes investigated in older male DCMI patients, whereas the expression of TOM40, TIM23, and the mitochondrial oxidative phosphorylation genes was significantly reduced in older female patients. Mitochondrial homeostasis in older male patients was further supported by the reduced acetylation of mitochondrial proteins as indicated by acetylated SOD2. The inflammatory markers NF-κB and TLR4 were downregulated in older male DCMI patients, whereas the expression of IL-18 was increased in older female patients. This was accompanied by progressed senescence in older DCMI hearts. In conclusion, older women experience more dramatic immunometabolic disorders on the cellular level than older men.

Mitochondrial impairment but not peripheral inflammation predicts greater Gulf War illness severity

Gulf War illness (GWI) is an important exemplar of environmentally-triggered chronic multisymptom illness, and a potential model for accelerated aging. Inflammation is the main hypothesized mechanism for GWI, with mitochondrial impairment also proposed. No study has directly assessed mitochondrial respiratory chain function (MRCF) on muscle biopsy in veterans with GWI (VGWI). We recruited 42 participants, half VGWI, with biopsy material successfully secured in 36. Impaired MRCF indexed by complex I and II oxidative phosphorylation with glucose as a fuel source (CI&CIIOXPHOS) related significantly or borderline significantly in the predicted direction to 17 of 20 symptoms in the combined sample. Lower CI&CIIOXPHOS significantly predicted GWI severity in the combined sample and in VGWI separately, with or without adjustment for hsCRP. Higher-hsCRP (peripheral inflammation) related strongly to lower-MRCF (particularly fatty acid oxidation (FAO) indices) in VGWI, but not in controls. Despite this, whereas greater MRCF-impairment predicted greater GWI symptoms and severity, greater inflammation did not. Surprisingly, adjusted for MRCF, higher hsCRP significantly predicted lesser symptom severity in VGWI selectively. Findings comport with a hypothesis in which the increased inflammation observed in GWI is driven by FAO-defect-induced mitochondrial apoptosis. In conclusion, impaired mitochondrial function-but not peripheral inflammation-predicts greater GWI symptoms and severity.

Cisplatin decreases voluntary wheel-running activity but does not impair food-motivated behavior in mice

Cisplatin is a chemotherapeutic agent that is still commonly used to treat solid tumors. However, it has several toxic side effects due in large part to the mitochondrial damage that it induces. As this mitochondrial damage is likely to result in a decrease in the amount of metabolic energy that is available for behavioral activities, it is not surprising that fatigue develops in cancer patients treated with cisplatin. The present preclinical study was initiated to determine whether the detrimental effects of cisplatin were more pronounced on physical effort requiring a lot of energy versus effort that not only requires less energy but also procures energy in the form of food. For this purpose, mice were either trained to run in a wheel or to work for food in various schedules of food reinforcement before being treated with cisplatin. The experiments were carried out only in male mice as we had already reported that sex differences in cisplatin-induced neurotoxicities are minimal. Cisplatin was administered daily for one cycle of five days, or two cycles separated by a five-day rest. As observed in previous experiments, cisplatin drastically reduced voluntary wheel running. In contrast, when cisplatin was administered to food-restricted mice trained to work for a food reward in a progressive ratio schedule or in a fixed-interval schedule, it tended to increase the number of responses emitted to obtain the food rewards. This increase was not associated with any change in the temporal distribution of responses during the interval between two reinforcements in mice submitted to the fixed interval schedule of food reinforcement. When cisplatin was administered to food-restricted mice trained in an effort-based decision-making task in which they had to choose between working for a grain pellet with little effort and working for a preferred chocolate pellet with more effort, it decreased the total number of responses emitted to obtain food rewards. However, this effect was much less marked than the decrease in wheel running induced by cisplatin. The decrease in the effort invested in the procurement of food rewards was not associated with any change in the relative distribution of effort between low reward and high reward during the time course of the test session. These findings show that cisplatin decreases energy-consuming activities but not energy-procuring activities unless they require a choice between options differing in their cost-benefit ratio. Furthermore, they indicate that the physical dimension of fatigue is more likely to develop in cisplatin-treated individuals than the motivational dimension of fatigue.

Cardiotoxicity in children with cancer treated with anthracyclines: A position statement on dexrazoxane

Cardiovascular disease is the leading cause of non-malignant morbidity and mortality in childhood cancer survivors (CCSs). Anthracyclines are included in many treatment regimens for paediatric cancer, but unfortunately, these compounds are cardiotoxic. One in 10 CCSs who has received an anthracycline will develop a symptomatic cardiac event over time. Given the crucial need to mitigate anthracycline-related cardiotoxicity (ARC), the authors critically examined published data to identify effective cardioprotective strategies. Based on their expert analysis of contemporary literature data, it was concluded that consideration should be given for routine use of dexrazoxane in children with cancer who are at risk of ARC.

Pharmacological effects and mechanisms of paeonol on antitumor and prevention of side effects of cancer therapy

Cancer represents one of the leading causes of mortality worldwide. Conventional clinical treatments include radiation therapy, chemotherapy, immunotherapy, and targeted therapy. However, these treatments have inherent limitations, such as multidrug resistance and the induction of short- and long-term multiple organ damage, ultimately leading to a significant decrease in cancer survivors' quality of life and life expectancy. Paeonol, a nature active compound derived from the root bark of the medicinal plant Paeonia suffruticosa, exhibits various pharmacological activities. Extensive research has demonstrated that paeonol exhibits substantial anticancer effects in various cancer, both in vitro and in vivo. Its underlying mechanisms involve the induction of apoptosis, the inhibition of cell proliferation, invasion and migration, angiogenesis, cell cycle arrest, autophagy, regulating tumor immunity and enhanced radiosensitivity, as well as the modulation of multiple signaling pathways, such as the PI3K/AKT and NF-κB signaling pathways. Additionally, paeonol can prevent adverse effects on the heart, liver, and kidneys induced by anticancer therapy. Despite numerous studies exploring paeonol's therapeutic potential in cancer, no specific reviews have been conducted. Therefore, this review provides a systematic summary and analysis of paeonol's anticancer effects, prevention of side effects, and the underlying mechanisms involved. This review aims to establish a theoretical basis for the adjunctive strategy of paeonol in cancer treatment, ultimately improving the survival rate and enhancing the quality of life for cancer patients.

The Lack of Synergy between Carvedilol and the Preventive Effect of Dexrazoxane in the Model of Chronic Anthracycline-Induced Cardiomyopathy

The anticancer efficacy of doxorubicin (DOX) is dose-limited because of cardiomyopathy, the most significant adverse effect. Initially, cardiotoxicity develops clinically silently, but it eventually appears as dilated cardiomyopathy with a very poor prognosis. Dexrazoxane (DEX) is the only FDA-approved drug to prevent the development of anthracycline cardiomyopathy, but its efficacy is insufficient. Carvedilol (CVD) is another product being tested in clinical trials for the same indication. This study's objective was to evaluate anthracycline cardiotoxicity in rats treated with CVD in combination with DEX. The studies were conducted using male Wistar rats receiving DOX (1.6 mg/kg b.w. i.p., cumulative dose: 16 mg/kg b.w.), DOX and DEX (25 mg/kg b.w. i.p.), DOX and CVD (1 mg/kg b.w. i.p.), or a combination (DOX + DEX + CVD) for 10 weeks. Afterward, in the 11th and 21st weeks of the study, echocardiography (ECHO) was performed, and the tissues were collected. The addition of CVD to DEX as a cardioprotective factor against DOX had no favorable advantages in terms of functional (ECHO), morphological (microscopic evaluation), and biochemical alterations (cardiac troponin I and brain natriuretic peptide levels), as well as systemic toxicity (mortality and presence of ascites). Moreover, alterations caused by DOX were abolished at the tissue level by DEX; however, when CVD was added, the persistence of DOX-induced unfavorable alterations was observed. The addition of CVD normalized the aberrant expression of the vast majority of indicated genes in the DOX + DEX group. Overall, the results indicate that there is no justification to use a simultaneous treatment of DEX and CVD in DOX-induced cardiotoxicity.

Maternal use of methamphetamine alters cardiovascular function in the adult offspring

Methamphetamine is one of the most commonly used illicit drugs during pregnancy. Most studies investigating the impact of maternal use of methamphetamine on children have focused on neurological outcomes. In contrast, cardiovascular outcomes in these children have not been characterized. Recent studies in rodents provide evidence that prenatal exposure to methamphetamine induces changes in cardiac gene expression, changes in the heart's susceptibility to ischemic injury, and changes in vascular function that may increase the risk of developing cardiovascular disorders later in life. Importantly, these changes are sex-dependent. This review summarizes our current understanding of how methamphetamine use during pregnancy impacts the cardiovascular function of adult offspring and highlights gaps in our knowledge of the potential cardiovascular risks associated with prenatal exposure to methamphetamine.

Vanillic acid alleviates methamphetamine-induced mitochondrial toxicity in cardiac mitochondria via antioxidant activity and inhibition of MPT Pore opening: an in-vitro study

BACKGROUND

Methamphetamine is widely abused in all parts of the world. It has been reported that short-term and long-term methamphetamine exposure could damage the dopaminergic system and induce cardiomyopathy and cardiotoxicity via mitochondrial dysfunction and oxidative stress. Vanillic acid (VA), a phenolic acid compound derived from plants, is known for its antioxidant and mitochondrial protection properties.

METHODS

In the current study we used VA for attenuating of Methamphetamine-induced mitochondrial toxicity in cardiac mitochondria. Isolated mitochondria obtained from rat heart were grouped as: control, methamphetamine (250 µM), VA (10, 50 and 100 µM) was cotreated with methamphetamine (250 µM) and VA (100 µM) alone. After 60 min, mitochondrial fraction including: succinate dehydrogenases (SDH) activity, mitochondrial membrane potential (MMP), mitochondrial swelling, mitochondrial glutathione (GSH), reactive oxygen species (ROS) and lipid peroxidation (LPO) were evaluated.

RESULTS

Methamphetamine exposure significantly disrupted mitochondrial function and induced ROS formation, lipid peroxidation, GSH depletion, MMP collapse and mitochondrial swelling, while VA significantly increased SDH activity as indicator of mitochondrial toxicity and dysfunction. VA also significantly decreased ROS formation, lipid peroxidation, mitochondrial swelling, MMP collapse and depletion of GSH in cardiac mitochondria in the presence of methamphetamine.

CONCLUSION

These findings suggested that VA is able to reduce methamphetamine-induced mitochondrial dysfunction and oxidative stress. Our results demonstrate that VA could potentially serve as a promising and accessible cardioprotective agent against methamphetamine-induced cardiotoxicity, via antioxidant and mitochondrial protection properties.

Mitophagy in atherosclerosis: from mechanism to therapy

Mitophagy is a type of autophagy that can selectively eliminate damaged and depolarized mitochondria to maintain mitochondrial activity and cellular homeostasis. Several pathways have been found to participate in different steps of mitophagy. Mitophagy plays a significant role in the homeostasis and physiological function of vascular endothelial cells, vascular smooth muscle cells, and macrophages, and is involved in the development of atherosclerosis (AS). At present, many medications and natural chemicals have been shown to alter mitophagy and slow the progression of AS. This review serves as an introduction to the field of mitophagy for researchers interested in targeting this pathway as part of a potential AS management strategy.

Trastuzumab-Mediated Cardiotoxicity and Its Preventive Intervention by Zingerone through Antioxidant and Inflammatory Pathway in Rats

Trastuzumab (TZB) is a new medicine, used to treat cancers of the breast and stomach. However, the cardiotoxic potential of this drug edges out its clinical advantages. The present study was designed to find out the effect of zingerone against trastuzumab-mediated cardiotoxicity in rats. In this study, five groups of rats with eight animals in each group were used. Group 1 was treated with normal saline, as a normal control (NC); Group 2 was treated with TZB (6 mg/kg/week-for five weeks) intraperitoneally as a toxic control. Groups 3 and 4 were pre-treated with zingerone (50 and 100 mg/kg, as per their body weight orally) along with five doses of TZB for five weeks, and Group 5 was treated with zingerone (100 mg/kg, body weight orally) as a control. TZB treatment showed cardiotoxicity as evidenced by increased levels of aspartate aminotransferase (AST), creatine kinase-myocardial band (CK-MB), lactate dehydrogenase (LDH), and lipid peroxidation (LPO) and decreased level of glutathione (GSH), and antioxidant enzymes such as glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-s- transferase (GST), catalase (CAT), and superoxide dismutase (SOD) activities. Zingerone pre-treatment significantly decreased the levels of AST, CK-MB, LDH, and LPO and increased GSH and antioxidant enzymes content toward their normal level. In the TZB-alone administered group, inflammatory cytokines (IL-2 and TNF-α) levels were also elevated. Pre-treatment with zingerone restored the level of IL-2 and TNF-α toward normal level. The current findings undoubtedly demonstrated zingerone's cardioprotective nature against TZB-mediated cardiotoxicity in rats with the evidence of histopathological recall.

MicroRNA-423-5p Mediates Cocaine-Induced Smooth Muscle Cell Contraction by Targeting Cacna2d2

Cocaine abuse increases the risk of atherosclerotic cardiovascular disease (CVD) and causes acute coronary syndromes (ACS) and hypertension (HTN). Significant research has explored the role of the sympathetic nervous system mediating the cocaine effects on the cardiovascular (CV) system. However, the response of the sympathetic nervous system alone is insufficient to completely account for the CV consequences seen in cocaine users. In this study, we examined the role of microRNAs (miRNAs) in mediating the effect of cocaine on the CV system. MiRNAs regulate many important biological processes and have been associated with both response to cocaine and CV disease development. Multiple miRNAs have altered expression in the CV system (CVS) upon cocaine exposure. To understand the molecular mechanisms underlying the cocaine response in the CV system, we studied the role of miRNA-423-5p and its target Cacna2d2 in the regulation of intracellular calcium concentration and SMC contractility, a critical factor in the modulation of blood pressure (BP). We used in vivo models to evaluate BP and aortic stiffness. In vitro, cocaine treatment decreased miR-423-5p expression and increased Cacna2d2 expression, which led to elevated intracellular calcium concentrations and increased SMC contractility. Overexpression of miR-423-5p, silencing of its target Cacna2d2, and treatment with a calcium channel blocker reversed the elevated SMC contractility caused by cocaine. In contrast, suppression of miR-423-5p increased the intracellular calcium concentration and SMC contractibility. In vivo, smooth muscle-specific overexpression of miR-423-5p ameliorated the increase in BP and aortic stiffness associated with cocaine use. Thus, miR-423-5p regulates SMC contraction by modulating Cacna2d2 expression increasing intracellular calcium concentrations. Modulation of the miR-423-5p-Cacna2d2-Calcium transport pathway may represent a novel therapeutic strategy to improve cocaine-induced HTN and aortic stiffness.

BGP-15 Protects against Doxorubicin-Induced Cell Toxicity via Enhanced Mitochondrial Function

Doxorubicin (DOX) is an efficacious and commonly used chemotherapeutic agent. However, its clinical use is limited due to dose-dependent cardiotoxicity. Several mechanisms have been proposed to play a role in DOX-induced cardiotoxicity, such as free radical generation, oxidative stress, mitochondrial dysfunction, altered apoptosis, and autophagy dysregulation. BGP-15 has a wide range of cytoprotective effects, including mitochondrial protection, but up to now, there is no information about any of its beneficial effects on DOX-induced cardiotoxicity. In this study, we investigated whether the protective effects of BGP-15 pretreatment are predominantly via preserving mitochondrial function, reducing mitochondrial ROS production, and if it has an influence on autophagy processes. H9c2 cardiomyocytes were pretreated with 50 μM of BGP-15 prior to different concentrations (0.1; 1; 3 μM) of DOX exposure. We found that BGP-15 pretreatment significantly improved the cell viability after 12 and 24 h DOX exposure. BGP-15 ameliorated lactate dehydrogenase (LDH) release and cell apoptosis induced by DOX. Additionally, BGP-15 pretreatment attenuated the level of mitochondrial oxidative stress and the loss of mitochondrial membrane potential. Moreover, BGP-15 further slightly modulated the autophagic flux, which was measurably decreased by DOX treatment. Hence, our findings clearly revealed that BGP-15 might be a promising agent for alleviating the cardiotoxicity of DOX. This critical mechanism appears to be given by the protective effect of BGP-15 on mitochondria.

Curcumin-Loaded Chitosan Nanoparticle Preparation and Its Protective Effect on Celecoxib-induced Toxicity in Rat isolated Cardiomyocytes and Mitochondria

Curcumin has a wide range of pharmacological activities, including antioxidant, anti-inflammatory and tissue protective. In here we hypothesized that curcumin-loaded chitosan-coated solid lipid nanoparticles (CuCsSLN) are able to increase its overall bioavailability and hence its antioxidant and mitochondria;/lysosomal protective properties of curcumin. CuCsSLN were prepared using solvent diffusion technique for formation of solid lipid nanoparticles (SLNs) and electrostatic coating of positive-charged chitosan to negative surface of SLNs. CuCsSLN showed the encapsulation efficiency of 91.4±2.7%, the mean particle size of 208±9 nm, the polydispersity index of 0.34±0.07, and the zeta potential of+53.5±3.7 mV. The scanning electron microscope (SEM) images of nanoparticles verified their nanometric size and also spherical shape. Curcumin was released from CuCsSLN in a sustain release pattern up to 24 hours. Then isolated cardiomyocytes and mitochondria were simultaneously treated with (1) control (0.05% ethanol), (2) celecoxib (20 µg/ml) treatment, (3) celecoxib (20 µg/ml)+++CuCsSLN (1 µg/ml) treatment, (4) CuCsSLN (1 µg/ml) treatment, (5) celecoxib (20 µg/ml)+++curcumin (10 µM) treatment and (6) curcumin (10 µM) treatment for 4 h at 37°C. The results showed that celecoxib (20 µg/ml) induced a significant increase in cytotoxicity, reactive oxygen species (ROS) formation, mitochondria membrane potential (ΔΨm) collapse, lipid peroxidation, oxidative stress and mitochondrial swelling while CuCsSLN and curcumin reverted the above toxic effect of celecoxib. Our data indicated that the effect of CuCsSLN in a number of experiments, is significantly better than that of curcumin which shows the role of chitosan nanoparticles in increasing effect of curcumin.

Mitochondrial DNA Copy Number Is a Potential Biomarker for Treatment Choice Between Metformin and Acarbose

Metformin is the first-line drug for type 2 diabetes (T2D) while acarbose is suggested as a viable alternative in Chinese patients with newly diagnosed T2D. However, few biomarkers have been established to guide the choice between these two agents. Mitochondrial DNA (mtDNA) copy number (mtDNA-CN) is a biomarker of mitochondrial function, which is associated with various metabolic outcomes. Using data from the trial of Metformin and Acarbose in Chinese as the Initial Hypoglycaemic Treatment (MARCH) (metformin n = 214; acarbose n = 198), we examined whether mtDNA-CN was associated with response to the drugs in terms of glycemic response and β-cell function protection response. The glycemic response is defined as the maximum glucose reduction of glycated hemoglobin A_1c , fasting plasma glucose, or postprandial blood glucose during 48 weeks. β-cell function protection response is defined as the maximum increment of insulinogenic index (IGI) or disposition index (DI). For all three glycemic responses, mtDNA-CN was not significantly associated with either metformin or acarbose. Importantly, for β-cell function protection response, we found the increased mtDNA-CN was significantly associated with more IGI increment (beta: 0.84; 95% confidence interval (CI), 0.02 to 1.66) in the metformin group, but less IGI increment (beta: -1.38; 95% CI, -2.52 to -0.23) in the acarbose group. A significant interaction (P = 0.008) between mtDNA-CN and the treatment group was observed. Consistent results were also obtained when DI increment was used as a measure of β-cell function response. This study demonstrated the potential application of mtDNA-CN in guiding the treatment choice between metformin and acarbose based on β-cell protection.

Molecular Cardiotoxic Effects of Proteasome Inhibitors Carfilzomib and Ixazomib and Their Combination with Dexamethasone Involve Mitochondrial Dysregulation

With the development and approval of new proteasome inhibitors, proteasome inhibition is increasingly recognized in cancer therapy. Besides successful anti-cancer effects in hematological cancers, side effects such as cardiotoxicity are limiting effective treatment. In this study, we used a cardiomyocyte model to investigate the molecular cardiotoxic mechanisms of carfilzomib (CFZ) and ixazomib (IXZ) alone or in combination with the immunomodulatory drug dexamethasone (DEX) which is frequently used in combination therapies in the clinic. According to our findings, CFZ showed a higher cytotoxic effect at lower concentrations than IXZ. DEX combination attenuated the cytotoxicity for both proteasome inhibitors. All drug treatments caused a marked increase in K48 ubiquitination. Both CFZ and IXZ caused an upregulation in cellular and endoplasmic reticulum stress protein (HSP90, HSP70, GRP94, and GRP78) levels and DEX combination attenuated the increased stress protein levels. Importantly, IXZ and IXZ-DEX treatments caused upregulation of mitochondria fission and fusion gene expression levels higher than caused by CFZ and CFZ-DEX combination. The IXZ-DEX combination reduced the levels of OXPHOS proteins (Complex II-V) more than the CFZ-DEX combination. Reduced mitochondrial membrane potential and ATP production were detected with all drug treatments in cardiomyocytes. Our findings suggest that the cardiotoxic effect of proteasome inhibitors may be due to their class effect and stress response and mitochondrial dysfunction may be involved in the cardiotoxicity process.

Higher mitochondrial DNA copy number is associated with metformin-induced weight loss

BACKGROUND

Considerable variability exists in response to metformin with few effective biomarkers to guide the treatment. Here we evaluated whether whole blood derived mitochondrial DNA copy number (mtDNA-CN) is a biomarker of metformin response as measured by glucose reduction or weight loss.

METHODS

Using data from the trial of Metformin (n = 304) and AcaRbose (n = 300) in Chinese as the initial Hypoglycaemic treatment (MARCH), we examined the association between mtDNA-CN and two metformin response outcomes of HbA1c reduction and weight loss. The acarbose arm was used as a comparator group. Whole blood mtDNA-CN was estimated by deep whole genome sequencing with adjustments for confounders. Multiple linear regression and repeated measurement analyses were used to evaluate the association between mtDNA-CN and drug response outcomes.

RESULTS

Here we show that glucose reduction is not significantly associated with mtDNA-CN and in either treatment arm. In the metformin arm, each increase of 1 SD in mtDNA-CN is significantly (P = 0.006) associated with a 0.43 kg more weight loss. Repeated measurement analysis shows that after 16 weeks of metformin monotherapy, patients in the top tertile of mtDNA-CN consistently lost 1.21 kg more weight than those in the bottom tertile (P < 0.001). In comparison, mtDNA-CN is not significantly associated with acarbose-induced weight loss.

CONCLUSIONS

Patients with higher mtDNA-CN are likely to lose more weight upon metformin treatment, suggesting mtDNA-CN as a potential novel biomarker for more effective weight management in type 2 diabetes.

Characterization of the Antitumor Potential of Extracts of Cannabis sativa Strains with High CBD Content in Human Neuroblastoma

Cannabis has been used for decades as a palliative therapy in the treatment of cancer. This is because of its beneficial effects on the pain and nausea that patients can experience as a result of chemo/radiotherapy. Tetrahydrocannabinol and cannabidiol are the main compounds present in Cannabis sativa, and both exert their actions through a receptor-mediated mechanism and through a non-receptor-mediated mechanism, which modulates the formation of reactive oxygen species. These oxidative stress conditions might trigger lipidic changes, which would compromise cell membrane stability and viability. In this sense, numerous pieces of evidence describe a potential antitumor effect of cannabinoid compounds in different types of cancer, although controversial results limit their implementation. In order to further investigate the possible mechanism involved in the antitumoral effects of cannabinoids, three extracts isolated from Cannabis sativa strains with high cannabidiol content were analyzed. Cell mortality, cytochrome c oxidase activity and the lipid composition of SH-SY5Y cells were determined in the absence and presence of specific cannabinoid ligands, with and without antioxidant pre-treatment. The cell mortality induced by the extracts in this study appeared to be related to the inhibition of the cytochrome c oxidase activity and to the THC concentration. This effect on cell viability was similar to that observed with the cannabinoid agonist WIN55,212-2. The effect was partially blocked by the selective CB1 antagonist AM281, and the antioxidant α-tocopherol. Moreover, certain membrane lipids were affected by the extracts, which demonstrated the importance of oxidative stress in the potential antitumoral effects of cannabinoids.

The role of ginseng derivatives against chemotherapy-induced cardiotoxicity: A systematic review of non-clinical studies

Aims

Although chemotherapy agents are used to treating cancers, they have serious side effects, like their harmful effects on the cardiovascular system, limiting the clinical use of these chemotherapy agents. This study aimed to systematically investigate the potential role of ginseng derivatives in the prevention of chemotherapy-induced cardiac toxicity.

Methods

This systematic review was performed according to PRISMA guidelines strategy in databases till August 2022. First, identify studies related to using search terms in titles and abstracts. After studying and screening 209 articles, 16 articles were selected in this study according to our inclusion and exclusion criteria.

Results

According to the findings of this study, ginseng derivatives showed significant changes in biochemical, histological, and heart weight loss, as well as a reduction in mortality, which occurred in the groups treated with chemotherapy agents compared to the control groups. Co-administration of ginseng derivatives with chemotherapy agents inhibited or reversed these changes to near-moderate levels. The protective effects of ginseng derivatives can be due to their anti-inflammatory, anti-oxidant, and anti-apoptotic action.

Conclusion

This systematic review shows evidence that concomitant administration of ginseng derivatives improves chemotherapy-induced cardiac toxicity. However, for better conclusions about the practical mechanisms of ginseng derivatives in reducing the cardiac toxic effects of chemotherapy agents and evaluating the efficacy and safety of the compound simultaneously, it is necessary to design comprehensive studies.

New Psychoactive Substances Intoxications and Fatalities during the COVID-19 Epidemic

In January 2020, the World Health Organization (WHO) issued a Public Health Emergency of International Concern, declaring the COVID-19 outbreak a pandemic in March 2020. Stringent measures decreased consumption of some drugs, moving the illicit market to alternative substances, such as New Psychoactive Substances (NPS). A systematic literature search was performed, using scientific databases such as PubMed, Scopus, Web of Science and institutional and government websites, to identify reported intoxications and fatalities from NPS during the COVID-19 pandemic. The search terms were: COVID-19, SARS-CoV-2, severe acute respiratory syndrome coronavirus 2, coronavirus disease 2019, intox*, fatal*, new psychoactive substance, novel psychoactive substance, smart drugs, new psychoactive substance, novel synthetic opioid, synthetic opioid, synthetic cathinone, bath salts, legal highs, nitazene, bath salt, legal high, synthetic cannabinoid, phenethylamine, phencyclidine, piperazine, novel benzodiazepine, benzodiazepine analogue, designer benzodiazepines, tryptamine and psychostimulant. From January 2020 to March 2022, 215 NPS exposures were reported in Europe, UK, Japan and USA. Single NPS class intoxications accounted for 25, while mixed NPS class intoxications represented only 3 cases. A total of 130 NPS single class fatalities and 56 fatalities involving mixed NPS classes were published during the pandemic. Synthetic opioids were the NPS class most abused, followed by synthetic cathinones and synthetic cannabinoids. Notably, designer benzodiazepines were frequently found in combination with fentalogues. Considering the stress to communities and healthcare systems generated by the pandemic, NPS-related information may be underestimated. However, we could not define the exact impacts of COVID-19 on processing of toxicological data, autopsy and death investigations.

King Oyster Mushroom, Pleurotus eryngii (Agaricomycetes), Extract Can Attenuate Doxorubicin-Induced Lung Damage by Inhibiting Oxidative Stress in Rats

Doxorubicin (DOX), a broad spectrum chemotherapeutic, has toxic effects on healthy tissues. Mitochondrial processes and oxidative stress act in the DOX-induced toxicity, therefore antioxidant therapies are widely used. The study was aimed to evaluate the therapeutic potential of Pleurotus eryngii extract (PEE), an extract of a fungus with antioxidant properties, against DOX-induced lung damage. Rats were divided into Control, DOX, DOX + PEE, and PEE groups (n = 6). DOX was administered intraperitoneally in a single dose (10 mg/kg BW) and PE (200 mg/kg BW) was administered by oral gavage every other day for 21 days. Histopathological evaluations, immunohistochemical analyses, total oxidant status (TOS)/total antioxidant status (TAS) method, and quantitative real-time polymerase chain reaction (qRT-PCR) analysis were performed. DOX led to severe histopathological disruptions in rat lungs. Also, DOX remarkably increased the expression of dynamin 1 like (DRP1) and decreased the expression of mitofusin 1 (MFN1) and mitofusin 2 (MFN2) genes, which are related to mitochondrial dynamics. Moreover, DOX caused an increase in TOS/ TAS and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels. On the other hand, PEE treatment remarkably normalized the histopathological findings, mitochondrial dynamics-related gene expressions, markers of oxidative stress, and DNA damage. The present study signs out that PEE can ameliorate the DOX-mediated lung toxicity and the antioxidant mechanism associated with mitochondrial dynamics can have a role in this potent therapeutic effect.

Irbesartan ameliorates inflammation via transendothelial leukocyte migration due to VCAM-1/NOX-1 signaling in cisplatin-induced cardiotoxicity

Objectives

Cisplatin (CP) is frequently used in various types of cancers. The cardiotoxic effects of this agent limit its usage. Our study seeks to investigate the protective effects of Irbesartan (IRB) on CP-induced cardiotoxicity.

Materials and Methods

The following four groups comprised thirty-two rats: control, CP, CP+IRB, and IRB. On the fourth day of the experiment, 5 mg/kg of CP was given to CP and CP+IRB groups intraperitoneally, and for seven days, water or IRB 50 mg/kg (orally) was administered. Vascular endothelial growth factor (VEGF), caspase-3 (Cas-3), vascular cell adhesion molecule-1 (VCAM-1), NADPH oxidase-1 (NOX-1), creatine kinase MB (CK-MB), and lactate dehydrogenase (LDH) were measured.

Results

The levels of VCAM-1, NOX-1, VEGF, Cas-3, and LDH were increased in the CP group. The treatment with IRB decreased VCAM-1, NOX-1, VEGF, Cas-3, and LDH levels significantly (P<0.05). Histopathological examination revealed normal heart architecture in Control and IRB groups. While marked hyperemia and myocardial cell degeneration were noticed in the CP group, significant amelioration was observed in the CP+IRB group. Aortas in the CP group showed endothelial damage and desquamation. IRB treatment markedly ameliorated histopathological findings in the CP+IRB group. Cardiac and aortic damage caused by CP was attenuated by IRB treatment owing to the anti-inflammatory and antiapoptotic effects of IRB.

Conclusion

IRB may help reduce the severity of CP-induced cardiac injury by limiting leukocyte migration and reducing inflammation and apoptosis.

New Concepts in Cardio-Oncology

Cancer and cardiovascular disease are the two major causes of morbidity and mortality in worldwide. Discovering new therapeutic agents for the management of breast cancer (BC) has increased the numbers of cancer survivors but with the risk of cardiovascular adverse events (CV-AEs). All drugs can potentially damage the cardiovascular system, with different types of clinical manifestations from ischemic myocardial disease to vasculitis, thrombosis or pericarditis. An early detection of CV-AEs guarantees an earlier treatment, which is associated with better outcomes. Cardio-oncology field enlarged its studies to improve prevention, monitoring and treatment of all cardiotoxic manifestations related to old or modern oncological agents. A multidisciplinary approach with a close partnership between oncologists and cardiologists is essential for an optimal management and therapeutic decision-making. The aim of this chapter is to review all types of cardiotoxic manifestations related to novel and old agents approved for treatment of BC patients including chemotherapy, anti-HER2 agents, cyclin-dependent kinase 4/6 inhibitors, PolyADP-ribose polymerase (PARP) inhibitors, antiangiogenic drugs and immunotherapy. We also focused our discussion on prevention, monitoring, treatment, and management of CV-AEs.

Cardiotoxicity from neoadjuvant targeted treatment for breast cancer prior to surgery

Cancer treatment has been gradually shifting from non-specific cytotoxic agents to molecularly targeted drugs. Breast cancer (BC), a malignant tumor with one of the highest incidence worldwide, has seen a rapid development in terms of targeted therapies, leading to a radical change in the treatment paradigm. However, the use of targeted drugs is accompanied by an increasing rate of deaths due to non-tumor-related causes in BC patients, with cardiovascular complications as the most common cause. Cardiovascular toxicity during antitumor therapy has become a high-risk factor for survival in BC patients. Targeted drug-induced cardiotoxicity exerts a wide range of effects on cardiac structure and function, including conduction disturbances, QT interval prolongation, impaired myocardial contractility, myocardial fibrosis, and hypertrophy, resulting in various clinical manifestations, e.g., arrhythmias, cardiomyopathy, heart failure, and even sudden death. In adult patients, the incidence of antitumor targeted drug-induced cardiotoxicity can reach 50%, and current preclinical evaluation tools are often insufficiently effective in predicting clinical cardiotoxicity. Herein, we reviewed the current status of the occurrence, causative mechanisms, monitoring methods, and progress in the prevention and treatment of cardiotoxicity associated with preoperative neoadjuvant targeted therapy for BC. It supplements the absence of relevant review on the latest research progress of preoperative neoadjuvant targeted therapy for cardiotoxicity, with a view to providing more reference for clinical treatment of BC patients.

Cannabidiol and Nano-Selenium Increase Microvascularization and Reduce Degenerative Changes in Superficial Breast Muscle in C. perfringens-Infected Chickens

Here, we demonstrated the potential of Cannabis-derived cannabidiol (CBD) and nanosized selenium (nano-Se) for the modulation of microvascularization and muscle fiber lesions in superficial breast muscle in C. perfringens-challenged chickens. The administration of CBD resulted in a decreased number of atrophic fibers (3.13 vs. 1.13/1.5 mm²) compared with the control, whereas nano-Se or both substances resulted in a decreased split fiber number (4.13 vs. 1.55/1.5 mm²) and in a lower number of necrotic myofibers (2.38 vs. 0.69/1.5 mm²) in breast muscle than the positive control. There was a significantly higher number of capillary vessels in chickens in the CBD+Nano-Se group than in the control and positive control groups (1.31 vs. 0.97 and 0.98, respectively). Feeding birds experimental diets lowered the activity of DNA damage repair enzymes, including 3,N4-ethenodeoxycytosine (by 39.6%), 1,N6-ethenodeoxyadenosine (by 37.5%), 8-oxo-guanine (by 36.2%), formamidopyrimidine (fapy)-DNA glycosylase (by 56.2%) and human alkyl adenine DNA glycosylase (by 40.2%) in the ileal mucosa, but it did not compromise the blood mitochondrial oxygen consumption rate (-2.67 OD/min on average). These findings indicate a potential link between gut mucosa condition and histopathological changes in superficial pectoral muscle under induced inflammation and show the ameliorative effect of CBD and nano-Se in this cross-talk due to their protection from mucosal DNA damage.

Remarks on Mitochondrial Myopathies

Mitochondrial myopathies represent a heterogeneous group of diseases caused mainly by genetic mutations to proteins that are related to mitochondrial oxidative metabolism. Meanwhile, a similar etiopathogenetic mechanism (i.e., a deranged oxidative phosphorylation and a dramatic reduction of ATP synthesis) reveals that the evolution of these myopathies show significant differences. However, some physiological and pathophysiological aspects of mitochondria often reveal other potential molecular mechanisms that could have a significant pathogenetic role in the clinical evolution of these disorders, such as: i. a deranged ROS production both in term of signaling and in terms of damaging molecules; ii. the severe modifications of nicotinamide adenine dinucleotide (NAD)+/NADH, pyruvate/lactate, and α-ketoglutarate (α-KG)/2- hydroxyglutarate (2-HG) ratios. A better definition of the molecular mechanisms at the basis of their pathogenesis could improve not only the clinical approach in terms of diagnosis, prognosis, and therapy of these myopathies but also deepen the knowledge of mitochondrial medicine in general.

Kinetic Mathematical Modeling of Oxidative Phosphorylation in Cardiomyocyte Mitochondria

Oxidative phosphorylation (OXPHOS) is an oxygen-dependent process that consumes catabolized nutrients to produce adenosine triphosphate (ATP) to drive energy-dependent biological processes such as excitation-contraction coupling in cardiomyocytes. In addition to in vivo and in vitro experiments, in silico models are valuable for investigating the underlying mechanisms of OXPHOS and predicting its consequences in both physiological and pathological conditions. Here, we compare several prominent kinetic models of OXPHOS in cardiomyocytes. We examine how their mathematical expressions were derived, how their parameters were obtained, the conditions of their experimental counterparts, and the predictions they generated. We aim to explore the general landscape of energy production mechanisms in cardiomyocytes for future in silico models.

Cardioprotective Effects of 6-Gingerol against Alcohol-Induced ROS-Mediated Tissue Injury and Apoptosis in Rats

The present study investigated the cardioprotective properties of 6-gingerol against alcohol-induced ROS-mediated cardiac tissue damage in rats. Experiments were conducted on 4 groups of rats, orally treated with control, 6-gingerol (10 mg/kg body weight), alcohol (6 g/kg body weight) and combination of 6-gingerol plus alcohol for two-month. In the results, we found 6-ginger treatment to alcohol-fed rats substantially suppressed ROS production in cardiac tissue. Alcohol-induced elevated 8-OHDG and protein carbonyls which represent oxidative modification of DNA and proteins were completely reversed by 6-gingerol. This was further endorsed by restored superoxide dismutase and catalase activities with 6-gingerol against alcohol-induced loss. The elevated cardiac biomarkers (CK-MB, cTn-T, cTn-I) and dyslipidemia in alcohol-intoxicated rats was significantly reversed by 6-gingerol. Furthermore, alcohol-induced apoptosis characterized by overexpression of cytochrome C, caspase-8 and caspase-9 was diminished with 6-gingerol treatment. Transmission electron microscope images conferred the cardioprotective properties of 6-gingerol as we have seen less structural derangements in mitochondria and reappearance of myofilaments. Our findings conclude that 6-ginger effectively protect alcohol-induced ROS-mediated cardiac tissue damage, which may be due to its potent antioxidant efficacy. Therefore, 6-gingerol could be a potential therapeutic molecule that can be used in the treatment of alcohol-induced myocardial injury.

Arsenic trioxide sensitizes pancreatic cancer cells to gemcitabine through downregulation of the TIMP1/PI3K/AKT/mTOR axis

Gemcitabine (GEM) is the first-line medication for pancreatic ductal adenocarcinoma (PDAC). However, over some treatment cycles, GEM sensitivity declines and chemotherapeutic resistance develops, resulting in tumor recurrence and metastasis. Therefore, it is critical to elucidate the mechanism of GEM chemoresistance. And a specific drug that is closely related to the mechanism is urgently required to sensitize GEM. Here, tissue inhibitor of matrix metalloproteinases 1 (TIMP1) and phosphorylated mammalian target of rapamycin (p-mTOR) were found to be substantially elevated in PDAC patients and were associated with worse overall survival. The TIMP1/PI3K/AKT/mTOR pathway was found in GEM-resistant PDAC cells and was revealed to be involved in epithelial-mesenchymal transition (EMT) and apoptosis. Furthermore, arsenic trioxide (ATO), a basic therapeutic drug for acute promyelocytic leukemia, mediated TIMP1 reduction by inducing reactive oxygen species generation and hampered the subsequent PI3K/AKT/mTOR axis. Moreover, the combination of ATO and GEM cooperatively suppressed the TIMP1/PI3K/AKT/mTOR pathway, synergistically inhibited EMT and promoted apoptosis. In vitro and in vivo, ATO combined with GEM has a collaborative anticancer effect, inhibiting cancer cell proliferation, migration, invasion, and suppressing tumor growth both in PDAC parental and GEM-resistant cells. Overall, the TIMP1/PI3K/AKT/mTOR pathway is present in PDAC and linked to GEM resistance. ATO suppresses the axis to sensitize GEM and reverse GEM resistance, suggesting a promising treatment for the disease.

Mitochondrial Effects of Common Cardiovascular Medications: The Good, the Bad and the Mixed

Mitochondria are central organelles in the homeostasis of the cardiovascular system via the integration of several physiological processes, such as ATP generation via oxidative phosphorylation, synthesis/exchange of metabolites, calcium sequestration, reactive oxygen species (ROS) production/buffering and control of cellular survival/death. Mitochondrial impairment has been widely recognized as a central pathomechanism of almost all cardiovascular diseases, rendering these organelles important therapeutic targets. Mitochondrial dysfunction has been reported to occur in the setting of drug-induced toxicity in several tissues and organs, including the heart. Members of the drug classes currently used in the therapeutics of cardiovascular pathologies have been reported to both support and undermine mitochondrial function. For the latter case, mitochondrial toxicity is the consequence of drug interference (direct or off-target effects) with mitochondrial respiration/energy conversion, DNA replication, ROS production and detoxification, cell death signaling and mitochondrial dynamics. The present narrative review aims to summarize the beneficial and deleterious mitochondrial effects of common cardiovascular medications as described in various experimental models and identify those for which evidence for both types of effects is available in the literature.

Prediction of drug-induced liver injury and cardiotoxicity using chemical structure and in vitro assay data

Drug-induced liver injury (DILI) and cardiotoxicity (DICT) are major adverse effects triggered by many clinically important drugs. To provide an alternative to in vivo toxicity testing, the U.S. Tox21 consortium has screened a collection of ∼10K compounds, including drugs in clinical use, against >70 cell-based assays in a quantitative high-throughput screening (qHTS) format. In this study, we compiled reference compound lists for DILI and DICT and compared the potential of Tox21 assay data with chemical structure information in building prediction models for human in vivo hepatotoxicity and cardiotoxicity. Models were built with four different machine learning algorithms (e.g., Random Forest, Naïve Bayes, eXtreme Gradient Boosting, and Support Vector Machine) and model performance was evaluated by calculating the area under the receiver operating characteristic curve (AUC-ROC). Chemical structure-based models showed reasonable predictive power for DILI (best AUC-ROC = 0.75 ± 0.03) and DICT (best AUC-ROC = 0.83 ± 0.03), while Tox21 assay data alone only showed better than random performance. DILI and DICT prediction models built using a combination of assay data and chemical structure information did not have a positive impact on model performance. The suboptimal predictive performance of the assay data is likely due to insufficient coverage of an adequately predictive number of toxicity mechanisms. The Tox21 consortium is currently expanding coverage of biological response space with additional assays that probe toxicologically important targets and under-represented pathways that may improve the prediction of in vivo toxicity such as DILI and DICT.

Contraction Band Necrosis with Dephosphorylated Connexin 43 in Rat Myocardium after Daily Cocaine Administration

Contraction band necrosis (CBN) is a common abnormality found in the myocardium of cocaine abusers, but is rarely reported in experimental models of cocaine abuse. Connexin 43 (Cx43) is essential for cardiac intercellular communication and the propagation of CBN. Under stress or injury, cardiac Cx43 is dephosphorylated, which is related to cardiomyocyte dysfunction and pathogenesis, whereas adiponectin exerts beneficial effects in the myocardium. In this study, we explore the effects of cocaine on cardiac Cx43 in vivo. Rats were administered cocaine via the tail vein at 20 mg/kg/day for 14 days, and showed widespread CBN, microfocal myocarditis and myocardial fibrosis, corresponding to a dysfunction of cardiac mitochondria under increased oxidative stress. The increase in dephosphorylated cardiac Cx43 and its negative correlation with the myocardial distribution of CBN after cocaine administration were determined. In addition, apoptosis and necroptosis, as well as increased adiponectin levels, were observed in the myocardium after cocaine exposure. Accordingly, we found altered profiles of cardiac Cx43, CBN and its negative correlation with dephosphorylated cardiac Cx43, and the possible involvement of adiponectin in the myocardium after 14 days of cocaine administration. The latter might play a protective role in the cardiotoxicity of cocaine. The current findings would be beneficial for establishing novel therapeutic strategies in cocaine-induced cardiac consequences.

Emerging mitochondrial signaling mechanisms in cardio-oncology: beyond oxidative stress

Many anticancer therapies (CTx) have cardiotoxic side effects that limit their therapeutic potential and cause long-term cardiovascular complications in cancer survivors. This has given rise to the field of cardio-oncology, which recognizes the need for basic, translational, and clinical research focused on understanding the complex signaling events that drive CTx-induced cardiovascular toxicity. Several CTx agents cause mitochondrial damage in the form of mitochondrial DNA deletions, mutations, and suppression of respiratory function and ATP production. In this review, we provide a brief overview of the cardiovascular complications of clinically used CTx agents and discuss current knowledge of local and systemic secondary signaling events that arise in response to mitochondrial stress/damage. Mitochondrial oxidative stress has long been recognized as a contributor to CTx-induced cardiotoxicity; thus, we focus on emerging roles for mitochondria in epigenetic regulation, innate immunity, and signaling via noncoding RNAs and mitochondrial hormones. Because data exploring mitochondrial secondary signaling in the context of cardio-oncology are limited, we also draw upon clinical and preclinical studies, which have examined these pathways in other relevant pathologies.

Synthesis, Molecular Docking, and Preclinical Evaluation of a New Succinimide Derivative for Cardioprotective, Hepatoprotective and Lipid-Lowering Effects

Cardiac and hepatotoxicities are major concerns in the development of new drugs. Better alternatives to other treatments are being sought to protect these vital organs from the toxicities of these pharmaceuticals. In this regard, a preclinical study is designed to investigate the histopathological effects of a new succinimide derivative (Comp-1) on myocardial and liver tissues, and the biochemical effects on selected cardiac biomarkers, hepatic enzymes, and lipid profiles. For this, an initially lethal/toxic dose was determined, followed by a grouping of selected albino rats into five groups (each group had n = 6). The control group received daily oral saline for 8 days. The 5-FU (5-Fluorouracil) group received oral saline daily for 8 days, added with the administration of a single dose of 5-FU (150 mg/kg I.P.) on day 5 of the study. The atenolol group received oral atenolol (20 mg/kg) for 8 days and 5-FU (150 mg/kg I.P.) on day 5 of the protocol. Similarly, two groups of rats treated with test compound (Comp-1) were administered with 5 mg/kg I.P. and 10 mg/kg I.P. for 8 days, followed by 5-FU (150 mg/kg I.P.) on day 5. Toxicity induced by 5-FU was manifested by increases in the serum creatinine kinase myocardial band (CK-MB), troponin I (cTnI) and lactate dehydrogenase (LDH), lipid profile, and selected liver enzymes, including ALP (alkaline phosphatase), ALT (alanine transaminase), AST (aspartate aminotransferase), BT (bilirubin total), and BD (direct bilirubin). These biomarkers were highly significantly decreased after the administration of the mentioned doses of the test compound (5 mg/kg and 10 mg/kg). Similarly, histological examination revealed cardiac and hepatic tissue toxicity by 5-FU. However, those toxic effects were also significantly recovered/improved after the administration of Comp-1 at the said doses. This derivative showed dose-dependent effects and was most effective at a dose of 10 mg/kg body weight. Binding energy data computed via docking simulations revealed that our compound interacts toward the human beta2-adrenergic G protein-coupled receptor (S = −7.89 kcal/mol) with a slight stronger affinity than the calcium channel T-type (S = −7.07 kcal/mol). In conclusion, the histological and biochemical results showed that the test compound (Comp-1) had prominent cardioprotective, hepatoprotective, and lipolytic effects against 5-FU-induced toxicity in the subjected animal model.

Silver nanoparticles induce developmental toxicity via oxidative stress and mitochondrial dysfunction in zebrafish (Danio rerio)

Sliver nanoparticles (AgNPs) are widely used in industry, agriculture, and medicine, potentially resulting in adverse effects on human health and aquatic environments. Here, we investigated the developmental toxicity of zebrafish embryos with acute exposure to AgNPs. Our results demonstrated developmental defects in 4 hpf zebrafish embryos after exposure to different concentrations of AgNPs for 72 h. In addition, RNA-seq profiling of zebrafish embryos after AgNPs treatment. Further Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that the differentially expressed genes (DEGs) were enriched in DNA replication initiation, oxidoreductase activity, DNA replication, cellular senescence, and oxidative phosphorylation signaling pathways in the AgNPs-treated group. Notably, we also found that AgNPs exposure could result in the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), the inhibition of superoxide dismutase (SOD), catalase (CAT), and mitochondrial complex I-V activities, and the downregulated expression of SOD, CAT, and mitochondrial complex I-IV chain-related genes. Moreover, the expression of mitochondrion-mediated apoptosis signaling pathway-related genes, such as bax, bcl2, caspase-3, and caspase-9, was significantly regulated after AgNPs exposure in zebrafish. Therefore, these findings demonstrated that AgNPs exposure could cause oxidative stress, induce mitochondrial dysfunction, and ultimately lead to developmental toxicity.

Protective Effect of Natural Medicinal Plants on Cardiomyocyte Injury in Heart Failure: Targeting the Dysregulation of Mitochondrial Homeostasis and Mitophagy

Heart failure occurs because of various cardiovascular pathologies, such as coronary artery disease or cardiorenal syndrome, eventually reaching end-stage disease. Various factors contribute to cardiac structural or functional changes that result in systolic or diastolic dysfunction. Several studies have confirmed that the key factor in heart failure progression is myocardial cell death, and mitophagy is the major mechanism regulating myocardial cell death in heart failure. The clinical mechanisms of heart failure are well understood in practice. However, the essential role of mitophagic regulation in heart failure has only recently received widespread attention. Receptor-mediated mitophagy is involved in various mitochondrial processes like oxidative stress injury, energy metabolism disorders, and calcium homeostasis, which are also the main causes of heart failure. Understanding of the diverse regulatory mechanisms in mitophagy and the complexity of its pathophysiology in heart failure remains incomplete. Related studies have found that various natural medicinal plants and active ingredients, such as flavonoids and saponins, can regulate mitophagy to a certain extent, improve myocardial function, and protect myocardial cells. This review comprehensively covers the relevant mechanisms of different types of mitophagy in regulating heart failure pathology and controlling mitochondrial adaptability to stress injury. Further, it explores the relationship between mitophagy and cardiac ejection dysfunction. Natural medicinal plant-targeted regulation strategies and scientific evidence on mitophagy were provided to elucidate current and potential strategies to apply mitophagy-targeted therapy for heart failure.

Putative COVID-19 therapies imatinib, lopinavir, ritonavir, and ivermectin cause hair cell damage: A targeted screen in the zebrafish lateral line

The biomedical community is rapidly developing COVID-19 drugs to bring much-need therapies to market, with over 900 drugs and drug combinations currently in clinical trials. While this pace of drug development is necessary, the risk of producing therapies with significant side-effects is also increased. One likely side-effect of some COVID-19 drugs is hearing loss, yet hearing is not assessed during preclinical development or clinical trials. We used the zebrafish lateral line, an established model for drug-induced sensory hair cell damage, to assess the ototoxic potential of seven drugs in clinical trials for treatment of COVID-19. We found that ivermectin, lopinavir, imatinib, and ritonavir were significantly toxic to lateral line hair cells. By contrast, the approved COVID-19 therapies dexamethasone and remdesivir did not cause damage. We also did not observe damage from the antibiotic azithromycin. Neither lopinavir nor ritonavir altered the number of pre-synaptic ribbons per surviving hair cell, while there was an increase in ribbons following imatinib or ivermectin exposure. Damage from lopinavir, imatinib, and ivermectin was specific to hair cells, with no overall cytotoxicity noted following TUNEL labeling. Ritonavir may be generally cytotoxic, as determined by an increase in the number of TUNEL-positive non-hair cells following ritonavir exposure. Pharmacological inhibition of the mechanotransduction (MET) channel attenuated damage caused by lopinavir and ritonavir but did not alter imatinib or ivermectin toxicity. These results suggest that lopinavir and ritonavir may enter hair cells through the MET channel, similar to known ototoxins such as aminoglycoside antibiotics. Finally, we asked if ivermectin was ototoxic to rats in vivo. While ivermectin is not recommended by the FDA for treating COVID-19, many people have chosen to take ivermectin without a doctor's guidance, often with serious side-effects. Rats received daily subcutaneous injections for 10 days with a clinically relevant ivermectin dose (0.2 mg/kg). In contrast to our zebrafish assays, ivermectin did not cause ototoxicity in rats. Our research suggests that some drugs in clinical trials for COVID-19 may be ototoxic. This work can help identify drugs with the fewest side-effects and determine which therapies warrant audiometric monitoring.

Integrating cell morphology with gene expression and chemical structure to aid mitochondrial toxicity detection

Mitochondrial toxicity is an important safety endpoint in drug discovery. Models based solely on chemical structure for predicting mitochondrial toxicity are currently limited in accuracy and applicability domain to the chemical space of the training compounds. In this work, we aimed to utilize both -omics and chemical data to push beyond the state-of-the-art. We combined Cell Painting and Gene Expression data with chemical structural information from Morgan fingerprints for 382 chemical perturbants tested in the Tox21 mitochondrial membrane depolarization assay. We observed that mitochondrial toxicants differ from non-toxic compounds in morphological space and identified compound clusters having similar mechanisms of mitochondrial toxicity, thereby indicating that morphological space provides biological insights related to mechanisms of action of this endpoint. We further showed that models combining Cell Painting, Gene Expression features and Morgan fingerprints improved model performance on an external test set of 244 compounds by 60% (in terms of F1 score) and improved extrapolation to new chemical space. The performance of our combined models was comparable with dedicated in vitro assays for mitochondrial toxicity. Our results suggest that combining chemical descriptors with biological readouts enhances the detection of mitochondrial toxicants, with practical implications in drug discovery.

Silk fibers assisted long-term 3D culture of human primary urinary stem cells via inhibition of senescence-associated genes: Potential use in the assessment of chronic mitochondrial toxicity

Despite being widely applied in drug development, existing in vitro 2D cell-based models are not suitable to assess chronic mitochondrial toxicity. A novel in vitro assay system mimicking in vivo microenvironment for this purpose is urgently needed. The goal of this study is to establish a 3D cell platform as a reliable, sensitive, cost-efficient, and high-throughput assay to predict drug-induced mitochondrial toxicity. We evaluated a long-term culture of human primary urine-derived stem cells (USC) seeded in 3D silk fiber matrix (3D USC-SFM) and further tested chronic mitochondrial toxicity induced by Zalcitabine (ddC, a nucleoside reverse transcriptase inhibitor) as a test drug, compared to USC grown in spheroids. The numbers of USC remain steady in 3D spheroids for 4 weeks and 3D SFM for 6 weeks. However, the majority (95%) of USC survived in 3D SFM, while cell numbers significantly declined in 3D spheroids at 6 weeks. Highly porous SFM provides large-scale numbers of cells by increasing the yield of USC 125-fold/well, which enables the carrying of sufficient cells for multiple experiments with less labor and lower cost, compared to 3D spheroids. The levels of mtDNA content and mitochondrial superoxide dismutase₂ [SOD2] as an oxidative stress biomarker and cell senescence genes (RB and P16, p21) of USC were all stably retained in 3D USC-SFM, while those were significantly increased in spheroids. mtDNA content and mitochondrial mass in both 3D culture models significantly decreased six weeks after treatment of ddC (0.2, 2, and 10 μM), compared to 0.1% DMSO control. Levels of complexes I, II, and III significantly decreased in 3D SFM-USC treated with ddC, compared to only complex I level which declined in spheroids. A dose- and time-dependent chronic MtT displayed in the 3D USC-SFM model, but not in spheroids. Thus, a long-term 3D culture model of human primary USC provides a cost-effective and sensitive approach potential for the assessment of drug-induced chronic mitochondrial toxicity.