Mitochondrial membrane transporters and metabolic switch in heart failure

A New Perspective on the Role of Alterations in Mitochondrial Proteins Involved in ATP Synthesis and Mobilization in Cardiomyopathies

The heart requires a continuous energy supply to sustain its unceasing contraction-relaxation cycle. Mitochondria, a double-membrane organelle, generate approximately 90% of cellular energy as adenosine triphosphate (ATP) through oxidative phosphorylation, utilizing the electrochemical gradient established by the respiratory chain. Mitochondrial function is compromised by damage to mitochondrial DNA, including point mutations, deletions, duplications, or inversions. Additionally, disruptions to proteins associated with mitochondrial membranes regulating metabolic homeostasis can impair the respiratory chain's efficiency. This results in diminished ATP production and increased generation of reactive oxygen species. This review provides an overview of mutations affecting mitochondrial transporters and proteins involved in mitochondrial energy synthesis, particularly those involved in ATP synthesis and mobilization, and it examines their role in the pathogenesis of specific cardiomyopathies.

Lycium barbarum glycopeptide ameliorates aging phenotypes and enhances cardiac metabolism by activating the PINK1/Parkin-mediated mitophagy pathway in D-galactose-induced mice

BACKGROUND

Aging is a complex biological process that disrupts tissue structure and impairs physiological function, which contributes to the development of age-related diseases such as cardiovascular disorders. However, effective treatment strategies are lacking.

OBJECTIVE

To investigate the geroprotective effects of Lycium barbarum glycopeptide (LbGp) and its potential mechanisms in a D-galactose-induced accelerated aging mouse model.

METHODS

Mice were subcutaneously injected with D-galactose (500 mg/kg/day) for 12 weeks to induce aging, while LbGp was orally administered (100 mg/kg/day) throughout the study. The geroprotective effects of LbGp were assessed by behavioral tests, cardiac echocardiography, pathohistological and transcriptomic analyses. Transmission electron microscopy was used to observe the ultrastructure of mitochondria. Mitochondrial stress assays and JC-1 fluorescent probe were conducted to evaluate mitochondrial function. Flow cytometer and western blot were performed to assess mitophagy flux.

RESULTS

LbGp treatment improved the aging phenotypes of D-galactose-induced mice, with a pronounced enhancement in cardiac function compared to neurocognitive and skeletal muscle functions. Transcriptome analysis indicated that LbGp ameliorated energy metabolism in the heart. Mitochondrial assays revealed LbGp improved mitochondrial function and preserved structural integrity of the mitochondrial inner membrane. LbGp attenuated mitochondrial fission and restored impaired PINK1/Parkin-mediated mitophagy pathway caused by D-galactose in cardiomyocytes.

CONCLUSION

LbGp can ameliorate aging phenotypes and enhance cardiac metabolism by activating the PINK1/Parkin-mediated mitophagy pathway in D-galactose-induced mice. These findings underscore its potential as a therapeutic agent for aging and aging-related cardiovascular diseases.

Role of mitochondrial homeostasis in D-galactose-induced cardiovascular ageing from bench to bedside

Ageing is an inevitable phenomenon which affects the cellular to the organism level in the progression of the time. Oxidative stress and inflammation are now widely regarded as the key processes involved in the aging process, which may then cause significant harm to mitochondrial DNA, leading to apoptosis. Normal circulatory function is a significant predictor of disease-free life expectancy. Indeed, disorders affecting the cardiovascular system, which are becoming more common, are the primary cause of worldwide morbidity, disability, and mortality. Cardiovascular aging may precede or possibly underpin overall, age-related health decline. Numerous studies have foundmitochondrial mechanistc approachplays a vital role in the in the onset and development of aging. The D-galactose (D-gal)-induced aging model is well recognized and commonly used in the aging study. In this review we redeposit the association of the previous and current studies on mitochondrial homeostasis and its underlying mechanisms in D-galactose cardiovascular ageing. Further we focus the novel and the treatment strategies to combat the major complication leading to the cardiovascular ageing.

Mitochondrial Structure and Function in Human Heart Failure

Despite clinical and scientific advancements, heart failure is the major cause of morbidity and mortality worldwide. Both mitochondrial dysfunction and inflammation contribute to the development and progression of heart failure. Although inflammation is crucial to reparative healing following acute cardiomyocyte injury, chronic inflammation damages the heart, impairs function, and decreases cardiac output. Mitochondria, which comprise one third of cardiomyocyte volume, may prove a potential therapeutic target for heart failure. Known primarily for energy production, mitochondria are also involved in other processes including calcium homeostasis and the regulation of cellular apoptosis. Mitochondrial function is closely related to morphology, which alters through mitochondrial dynamics, thus ensuring that the energy needs of the cell are met. However, in heart failure, changes in substrate use lead to mitochondrial dysfunction and impaired myocyte function. This review discusses mitochondrial and cristae dynamics, including the role of the mitochondria contact site and cristae organizing system complex in mitochondrial ultrastructure changes. Additionally, this review covers the role of mitochondria-endoplasmic reticulum contact sites, mitochondrial communication via nanotunnels, and altered metabolite production during heart failure. We highlight these often-neglected factors and promising clinical mitochondrial targets for heart failure.

Construction of dose prediction model and identification of sensitive genes for space radiation based on single-sample networks under spaceflight conditions

PURPOSE

To identify sensitive genes for space radiation, we integrated the transcriptomic samples of spaceflight mice from GeneLab and predicted the radiation doses absorbed by individuals in space.

METHODS AND MATERIALS

A single-sample network (SSN) for each individual sample was constructed. Then, using machine learning and genetic algorithms, we built the regression models to predict the absorbed dose equivalent based on the topological structure of SSNs. Moreover, we analyzed the SSNs from each tissue and compared the similarities and differences among them.

RESULTS

Our model exhibited excellent performance with the following metrics: R 2 = 0.980 , MSE = 6.74 e - 04 , and the Pearson correlation coefficient of 0.990 (p value <.0001) between predicted and actual values. We identified 20 key genes, the majority of which had been proven to be associated with radiation. However, we uniquely established them as space radiation sensitive genes for the first time. Through further analysis of the SSNs, we discovered that the different tissues exhibited distinct mechanisms in response to space stressors.

CONCLUSIONS

The topology structures of SSNs effectively predicted radiation doses under spaceflight conditions, and the SSNs revealed the gene regulatory patterns within the organisms under space stressors.

Involvement of Ferroptosis Induction and Oxidative Phosphorylation Inhibition in the Anticancer-Drug-Induced Myocardial Injury: Ameliorative Role of Pterostilbene

Patients with cancer die from cardiac dysfunction second only to the disease itself. Cardiotoxicity caused by anticancer drugs has been emphasized as a possible cause; however, the details remain unclear. To investigate this mechanism, we treated rat cardiomyoblast H9c2 cells with sunitinib, lapatinib, 5-fluorouracil, and cisplatin to examine their effects. All anticancer drugs increased ROS, lipid peroxide, and iron (II) levels in the mitochondria and decreased glutathione peroxidase-4 levels and the GSH/GSSG ratio. Against this background, mitochondrial iron (II) accumulates through the unregulated expression of haem oxygenase-1 and ferrochelatase. Anticancer-drug-induced cell death was suppressed by N-acetylcysteine, deferoxamine, and ferrostatin, indicating ferroptosis. Anticancer drug treatment impairs mitochondrial DNA and inhibits oxidative phosphorylation in H9c2 cells. Similar results were observed in the hearts of cancer-free rats treated with anticancer drugs in vitro. In contrast, treatment with pterostilbene inhibited the induction of ferroptosis and rescued the energy restriction induced by anticancer drugs both in vitro and in vivo. These findings suggest that induction of ferroptosis and inhibition of oxidative phosphorylation are mechanisms by which anticancer drugs cause myocardial damage. As pterostilbene ameliorates these mechanisms, it is expected to have significant clinical applications.

Mitochondrial Dysfunction in Heart Failure: From Pathophysiological Mechanisms to Therapeutic Opportunities

Mitochondrial dysfunction, a feature of heart failure, leads to a progressive decline in bioenergetic reserve capacity, consisting in a shift of energy production from mitochondrial fatty acid oxidation to glycolytic pathways. This adaptive process of cardiomyocytes does not represent an effective strategy to increase the energy supply and to restore the energy homeostasis in heart failure, thus contributing to a vicious circle and to disease progression. The increased oxidative stress causes cardiomyocyte apoptosis, dysregulation of calcium homeostasis, damage of proteins and lipids, leakage of mitochondrial DNA, and inflammatory responses, finally stimulating different signaling pathways which lead to cardiac remodeling and failure. Furthermore, the parallel neurohormonal dysregulation with angiotensin II, endothelin-1, and sympatho-adrenergic overactivation, which occurs in heart failure, stimulates ventricular cardiomyocyte hypertrophy and aggravates the cellular damage. In this review, we will discuss the pathophysiological mechanisms related to mitochondrial dysfunction, which are mainly dependent on increased oxidative stress and perturbation of the dynamics of membrane potential and are associated with heart failure development and progression. We will also provide an overview of the potential implication of mitochondria as an attractive therapeutic target in the management and recovery process in heart failure.

Associations between plasma metal elements and risk of cognitive impairment among Chinese older adults

Background

The relationship between plasma metal elements and cognitive function is unclear, especially in extremely older individuals. This present study aimed to explore the association between plasma metal concentrations and the risk of cognitive impairment (CI) in Chinese extremely older adults.

Methods

Individuals aged ≥90 years with plasm metal concentration data from the fifth wave of the 2008 Chinese Longitudinal Healthy Longevity Survey were included. Plasma selenium (Se), manganese (Mn), magnesium (Mg), calcium (Ca), iron (Fe), copper (Cu), and zinc (Zn) concentrations were measured using inductively coupled plasma optical emission spectroscopy. Cognitive function was assessed by the Chinese version of the mini-mental state examination.

Results

The study enrolled 408 participants. Participants with CI had significantly lower plasma Se, Mn, and Fe levels and higher Ca levels than those with normal cognitive function (p < 0.05). Plasma Se, Mn, Ca, and Fe concentrations were significantly associated with CI risk in both single- and multiple-element logistic regression models. Additionally, the multiple-element model results showed that the adjusted odds ratios for CI were 0.042 (95% confidence interval 0.016-0.109), 0.106 (0.044-0.255), 7.629 (3.211-18.124) and 0.092 (0.036-0.233) for the highest quartiles compared to the lowest quartiles of Se, Mn, Ca, and Fe, respectively. Moreover, subgroup analyses by age, sex, and body mass index suggested a consistent significant correlation (p < 0.05).

Conclusion

Therefore, decreased plasma Se, Mn, and Fe and increased plasma Ca levels were associated with CI risk in Chinese older adults. These findings are of great significance for the development of programs to delay cognitive decline in the elderly.

Cardiac PET Imaging of ATP Binding Cassette (ABC) Transporters: Opportunities and Challenges

Adenosine triphosphate binding cassette (ABC) transporters are a broad family of membrane protein complexes that use energy to transport molecules across cells and/or intracellular organelle lipid membranes. Many drugs used to treat cardiac diseases have an affinity for these transporters. Among others, P-glycoprotein (P-gp) plays an essential role in regulating drug concentrations that reach cardiac tissue and therefore contribute to cardiotoxicity. As a molecular imaging modality, positron emission tomography (PET) has emerged as a viable technique to investigate the function of P-gp in organs and tissues. Using PET imaging to evaluate cardiac P-gp function provides new insights for drug development and improves the precise use of medications. Nevertheless, information in this field is limited. In this review, we aim to examine the current applications of ABC transporter PET imaging and its tracers in the heart, with a specific emphasis on P-gp. Furthermore, the opportunities and challenges in this novel field will be discussed.

Metabolism configures immune response across multi-systems: Lessons from COVID-19

Several studies over the last decade demonstrate the recruitment of immune cells, increased inflammatory cytokines, and chemokine in patients with metabolic diseases, including heart failure, parenchymal inflammation, obesity, tuberculosis, and diabetes mellitus. Metabolic rewiring of immune cells is associated with the severity and prevalence of these diseases. The risk of developing COVID-19/SARS-CoV-2 infection increases in patients with metabolic dysfunction (heart failure, diabetes mellitus, and obesity). Several etiologies, including fatigue, dyspnea, and dizziness, persist even months after COVID-19 infection, commonly known as Post-Acute Sequelae of CoV-2 (PASC) or long COVID. A chronic inflammatory state and metabolic dysfunction are the factors that contribute to long COVID. Here, this study explores the potential link between pathogenic metabolic and immune alterations across different organ systems that could underlie COVID-19 and PASC. These interactions could be utilized for targeted future therapeutic approaches.

Asiatic acid protects against pressure overload-induced heart failure in mice by inhibiting mitochondria-dependent apoptosis

BACKGROUND

Mitochondrial dysfunction and subsequent cardiomyocyte apoptosis significantly contribute to pressure overload-induced heart failure (HF). A highly oxidative environment leads to mitochondrial damage, further exacerbating this condition. Asiatic acid (AA), a proven antioxidant and anti-hypertrophic agent, might provide a solution, but its role and mechanisms in chronic pressure overload-induced HF remain largely unexplored.

METHODS

We induced pressure overload in mice using transverse aortic constriction (TAC) and treated them with AA (100 mg/kg/day) or vehicle daily by oral gavage for 8 weeks. The effects of AA on mitochondrial dysfunction, oxidative stress-associated signaling pathways, and overall survival were evaluated. Additionally, an in vitro model using hydrogen peroxide-exposed neonatal rat cardiomyocytes was established to further investigate the role of AA in oxidative stress-induced mitochondrial apoptosis.

RESULTS

AA treatment significantly improved survival and alleviated cardiac dysfunction in TAC-induced HF mice. It preserved mitochondrial structure, reduced the LVW/BW ratio by 20.24%, mitigated TAC-induced mitochondrial-dependent apoptosis by significantly lowering the Bax/Bcl-2 ratio and cleaved caspase-9/3 levels, and attenuated oxidative stress. AA treatment protected cardiomyocytes from hydrogen peroxide-induced apoptosis, with concurrent modulation of mitochondrial-dependent apoptosis pathway-related proteins and the JNK pathway.

CONCLUSIONS

Our findings suggest that AA effectively combats chronic TAC-induced and hydrogen peroxide-induced cardiomyocyte apoptosis through a mitochondria-dependent mechanism. AA reduces cellular levels of oxidative stress and inhibits the activation of the JNK pathway, highlighting its potential therapeutic value in the treatment of HF.

Improving mitochondrial function in preclinical models of heart failure: therapeutic targets for future clinical therapies?

INTRODUCTION

Heart failure is a complex clinical syndrome resulting from the unsuccessful compensation of symptoms of myocardial damage. Mitochondrial dysfunction is a process that occurs because of an attempt to adapt to the disruption of metabolic and energetic pathways occurring in the myocardium. This, in turn, leads to further dysfunction in cardiomyocyte processes. Currently, many therapeutic strategies have been implemented to improve mitochondrial function, but their effectiveness varies widely.

AREAS COVERED

This review focuses on new models of therapeutic strategies targeting mitochondrial function in the treatment of heart failure.

EXPERT OPINION

Therapeutic strategies targeting mitochondria appear to be a valuable option for treating heart failure. Currently, the greatest challenge is to develop new research models that could restore the disrupted metabolic processes in mitochondria as comprehensively as possible. Only the development of therapies that focus on improving as many dysregulated mitochondrial processes as possible in patients with heart failure will be able to bring the expected clinical improvement, along with inhibition of disease progression. Combined strategies involving the reduction of the effects of oxidative stress and mitochondrial dysfunction, appear to be a promising possibility for developing new therapies for a complex and multifactorial disease such as heart failure.

Cardiotoxicity of chloroquine and hydroxychloroquine through mitochondrial pathway

BACKGROUND

Medical therapies can cause cardiotoxicity. Chloroquine (QC) and hydroxychloroquine (HQC) are drugs used in the treatment of malaria and skin and rheumatic disorders. These drugs were considered to help treatment of coronavirus disease (COVID-19) in 2019. Despite the low cost and availability of QC and HQC, reports indicate that this class of drugs can cause cardiotoxicity. The mechanism of this event is not well known, but evidence shows that QC and HQC can cause cardiotoxicity by affecting mitochondria and lysosomes.

METHODS

Therefore, our study was designed to investigate the effects of QC and HQC on heart mitochondria. In order to achieve this aim, mitochondrial function, reactive oxygen species (ROS) level, mitochondrial membrane disruption, and cytochrome c release in heart mitochondria were evaluated. Statistical significance was determined using the one-way and two-way analysis of variance (ANOVA) followed by post hoc Tukey to evaluate mitochondrial succinate dehydrogenase (SDH) activity and cytochrome c release, and Bonferroni test to evaluate the ROS level, mitochondrial membrane potential (MMP) collapse, and mitochondrial swelling.

RESULTS

Based on ANOVA analysis (one-way), the results of mitochondrial SDH activity showed that the IC50 concentration for CQ is 20 µM and for HCQ is 50 µM. Based on two-way ANOVA analysis, the highest effect of CQ and HCQ on the generation of ROS, collapse in the MMP, and mitochondrial swelling were observed at 40 µM and 100 µM concentrations, respectively (p < 0.05). Also, the highest effect of these two drugs has been observed in 60 min (p < 0.05). The statistical results showed that compared to CQ, HCQ is able to cause the release of cytochrome c from mitochondria in all applied concentrations (p < 0.05).

CONCLUSIONS

The results suggest that QC and HQC can cause cardiotoxicity which can lead to heart disorders through oxidative stress and disfunction of heart mitochondria.

Extracellular vesicles DJ-1 derived from hypoxia-conditioned hMSCs alleviate cardiac hypertrophy by suppressing mitochondria dysfunction and preventing ATRAP degradation

BACKGROUND

As a pathological myocardial remodeling process in a variety of cardiovascular diseases, cardiac hypertrophy still has no effective treatment. Human mesenchymal stem cells (hMSCs) derived extracellular vesicles (EVs) has been recognized as a promising treatment strategy for cardiac disease.

METHODS

In this study, the inhibitory effects on cardiac hypertrophy are compared between normoxia-conditioned hMSC-derived EVs (Nor-EVs) and hypoxia-conditioned hMSC-derived EVs (Hypo-EVs) in neonatal rat cardiomyocytes (NRCMs) after angiotensin II (Ang II) stimulation and in a mouse model of transverse aortic constriction (TAC).

RESULTS

We demonstrate that Hypo-EVs exert an increased inhibitory effect on cardiac hypertrophy compared with Nor-EVs. Parkinson disease protein 7 (PARK7/DJ-1) is identify as a differential protein between Nor-EVs and Hypo-EVs by quantitative proteomics analysis. Results show that DJ-1, which is rich in Hypo-EVs, alleviates mitochondrial dysfunction and excessive mitochondrial reactive oxygen species (mtROS) production as an antioxidant. Mechanistic studies demonstrate for the first time that DJ-1 may suppress cardiac hypertrophy by inhibiting the activity of proteasome subunit beta type 10 (PSMB10) through a direct physical interaction. This interaction can inhibit angiotensin II type 1 receptor (AT1R)-mediated signaling pathways resulting in cardiac hypertrophy through alleviating ubiquitination degradation of AT1R-associated protein (ATRAP).

CONCLUSIONS

When taken together, our study suggests that Hypo-EVs have significant potential as a novel therapeutic agent for the treatment of cardiac hypertrophy.

The Therapeutic Strategies Targeting Mitochondrial Metabolism in Cardiovascular Disease

Cardiovascular disease (CVD) is a group of systemic disorders threatening human health with complex pathogenesis, among which mitochondrial energy metabolism reprogramming has a critical role. Mitochondria are cell organelles that fuel the energy essential for biochemical reactions and maintain normal physiological functions of the body. Mitochondrial metabolic disorders are extensively involved in the progression of CVD, especially for energy-demanding organs such as the heart. Therefore, elucidating the role of mitochondrial metabolism in the progression of CVD is of great significance to further understand the pathogenesis of CVD and explore preventive and therapeutic methods. In this review, we discuss the major factors of mitochondrial metabolism and their potential roles in the prevention and treatment of CVD. The current application of mitochondria-targeted therapeutic agents in the treatment of CVD and advances in mitochondria-targeted gene therapy technologies are also overviewed.

Involvement of Multidrug Resistance Modulators in the Regulation of the Mitochondrial Permeability Transition Pore

The permeability transition pore in mitochondria (MPTP) and the ATP-binding cassette transporters (АВС transporters) in cell membranes provide the efflux of low-molecular compounds across mitochondrial and cell membranes, respectively. The inhibition of ABC transporters, especially of those related to multi drug resistance (MDR) proteins, is an actively explored approach to enhance intracellular drug accumulation and increase thereby the efficiency of anticancer therapy. Although there is evidence showing the simultaneous effect of some inhibitors on both MDR-related proteins and mitochondrial functions, their influence on MPTP has not been previously studied. We examined the participation of verapamil and quinidine, classified now as the first generation of MDR modulators, and avermectin, which has recently been actively studied as an MDR inhibitor, in the regulation of the MPTP opening. In experiments on rat liver mitochondria, we found that quinidine lowered and verapamil increased the threshold concentrations of calcium ions required for MPTP opening, and that they both decreased the rate of calcium-induced swelling of mitochondria. These effects may be associated with the positive charge of the drugs and their aliphatic properties. Avermectin not only decreased the threshold concentration of calcium ions, but also by itself induced the opening of MPTP and the mitochondrial swelling inhibited by ADP and activated by carboxyatractyloside, the substrate and inhibitor of adenine nucleotide translocase (ANT), which suggests the involvement of ANT in the process. Thus, these data indicate an additional opportunity to evaluate the effectiveness of MDR modulators in the context of their influence on the mitochondrial-dependent apoptosis.

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.

Urban fine particulate matter causes cardiac hypertrophy through calcium-mediated mitochondrial bioenergetics dysfunction in mice hearts and human cardiomyocytes

In recent years, the cardiovascular toxicity of urban fine particulate matter (PM_2.5) has sparked significant alarm. Mitochondria produce 90% of ATP and make up 30% of the volume of cardiomyocytes. Thus knowledge of myocardial mitochondrial dysfunction due to PM_2.5 exposure is essential for further cardiotoxic effects. Here, the mechanism of PM_2.5-induced cardiac hypertrophy through calcium overload and mitochondrial dysfunction was investigated in vivo and in vitro. Male and female BALB/c mice were given 1.28, 5.5, and 11 mg PM_2.5/kg bodyweight weekly through oropharyngeal inhalation for four weeks and were assigned to low, medium, and high dose groups, respectively. PM_2.5-induced myocardial edema and cardiac hypertrophy were detected in the high-dose group. Mitochondria were scattered and ruptured with abnormal ultrastructural morphology. In vitro experiments on human cardiomyocyte AC16 showed that exposure to PM_2.5 for 24 h caused opened mitochondrial permeability transition pore --leading to excessive calcium production, decreased mitochondrial membrane potential, weakened mitochondrial respiratory metabolism capacity, and decreased ATP production. Nevertheless, the administration of calcium chelator ameliorated the mitochondrial damage in the PM_2.5-treated group. Our in vivo and in vitro results confirmed that calcium overload under PM_2.5 exposure triggered mTOR/AKT/GSK-3β activation, leading to mitochondrial bioenergetics dysfunction and cardiac hypertrophy.

Reprogramming of Fatty Acid Metabolism in Gynaecological Cancers: Is There a Role for Oestradiol?

Gynaecological cancers are among the leading causes of cancer-related death among women worldwide. Cancer cells undergo metabolic reprogramming to sustain the production of energy and macromolecules required for cell growth, division and survival. Emerging evidence has provided significant insights into the integral role of fatty acids on tumourigenesis, but the metabolic role of high endogenous oestrogen levels and increased gynaecological cancer risks, notably in obesity, is less understood. This is becoming a renewed research interest, given the recently established association between obesity and incidence of many gynaecological cancers, including breast, ovarian, cervical and endometrial cancers. This review article, hence, comprehensively discusses how FA metabolism is altered in these gynaecological cancers, highlighting the emerging role of oestradiol on the actions of key regulatory enzymes of lipid metabolism, either directly through its classical ER pathways, or indirectly via the IGIFR pathway. Given the dramatic rise in obesity and parallel increase in the prevalence of gynaecological cancers among premenopausal women, further clarifications of the complex mechanisms underpinning gynaecological cancers are needed to inform future prevention efforts. Hence, in our review, we also highlight opportunities where metabolic dependencies can be exploited as viable therapeutic targets for these hormone-responsive cancers.

The [2Fe-2S] protein CISD2 plays a key role in preventing iron accumulation in cardiomyocytes

Considered a key aging gene, CISD2, encoding CDGSH iron-sulfur domain-containing protein 2, plays a central role in regulating calcium homeostasis, preventing mitochondrial dysfunction, and the activation of autophagy and apoptosis in different cells. Here, we show that cardiomyocytes from CISD2-null mice accumulate high levels of iron and contain high levels of transferrin receptor and ferritin. Using proteomics and transmission electron microscopy, we further show that the lack of CISD2 induces several features of the aging process in young mice, but other features are not induced. Taken together, our findings suggest that CISD2 protects cardiomyocytes from overaccumulation of iron, which is common in aging hearts and can contribute to the pathogenesis of heart failure.

Insights Into Ferroptosis, a Novel Target for the Therapy of Cancer

Ferroptosis is a new form of programmed cell death (PCD) characterized by an excess iron accumulation and subsequent unbalanced redox states. Ferroptosis is different from the already reported PCD and has unique morphological features and biochemical processes. Ferroptosis was first elaborated by Brent R. Stockwell’s lab in 2012, in which small molecules erastin and RSL-3 induce PCD in Ras mutant cell lines. Ferroptosis involves various physiological processes and occurrence of disease and especially shows strong potential in cancer treatment. Development of small molecule compounds based on Stockwell’s research was found to kill cancer cells, and some FDA-approved drugs were discovered to result in ferroptosis of cancer cells. Radiotherapy and checkpoint therapy have been widely used as a treatment for many types of cancer. Recently, some papers have reported that chemotherapy, radiotherapy, and checkpoint therapy induce ferroptosis of cancer cells, which provides new strategies for cancer treatment. Nevertheless, the limitless proliferation of tumor cells and the lack of cell death mechanisms are important reasons for drug resistance for tumor therapy. Therefore, we reviewed the molecular mechanism of ferroptosis and sensitivity to ferroptosis of different cancer cells and tumor treatment strategy.

Health risks of sulfentrazone exposure during zebrafish embryo-larvae development at environmental concentration

Knowledge about the negative effects and mechanism of sulfentrazone (SUL) on aquatic early life stages is still limited. Here we investigated the lethal and sub-lethal effects of SUL during zebrafish embryo-larvae development. Results demonstrated that the 96 h and 120 h-LC₅₀ of SUL to embryonic zebrafish was 2.02 mg/L, and the 30 d-LC₅₀ was 0.899 mg/L after embryos exposed to SUL for 30 d. High concentrations of SUL delayed yolk sac absorption, disordered the hatching and heart rate during zebrafish embryonic stage, while 0.0100-0.100 mg/L SUL had no phenotypic changes on embryonic development, but decreased the body weight of larvae after 30 d exposure. RNA-seq identified 321, 394 and 727 differentially expressed genes in larvae after embryos exposed to 0.0100 mg/L, 0.0400 mg/L and 0.400 mg/L SUL for 30 d, found that the transcriptional profiles involved in heart development and endocrine disruption were simultaneously influenced by different concentrations of SUL, such as adrenergic signaling in cardiomyocytes, cardiac muscle contraction, cell adhesion molecules and steroid biosynthesis. Biochemical analysis showed that SUL increased the levels of E₂, T₃ and TSH, induced the activities of mitochondrial complex IV, cytochrome c oxidase, Ca²⁺-ATPase, total Na⁺K⁺-ATPase and Ca²⁺Mg²⁺-ATPase, and decreased ATP formation after embryos exposed to SUL for 5 d and 30 d. Further comprehensive analysis demonstrated that SUL caused more significantly alteration on the transcript, level or activity of the key elements involved in heart development and endocrine disruption after 30 d exposure, indicated long-term SUL exposure might cause more negative effects on zebrafish at doses below the presumed no-observed-adverse-effect level during early life development. The results inferred the environmental concentration of SUL might cause potential cardiac and endocrine health risk in zebrafish later life stages, also facilitated a better understanding of the sub-lethal effects and molecular mechanism of SUL on aquatic organism.

PUFA Supplementation and Heart Failure: Effects on Fibrosis and Cardiac Remodeling

Heart failure (HF) characterized by cardiac remodeling is a condition in which inflammation and fibrosis play a key role. Dietary supplementation with n-3 polyunsaturated fatty acids (PUFAs) seems to produce good results. In fact, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have anti-inflammatory and antioxidant properties and different cardioprotective mechanisms. In particular, following their interaction with the nuclear factor erythropoietin 2 related factor 2 (NRF2), the free fatty acid receptor 4 (Ffar4) receptor, or the G-protein coupled receptor 120 (GPR120) fibroblast receptors, they inhibit cardiac fibrosis and protect the heart from HF onset. Furthermore, n-3 PUFAs increase the left ventricular ejection fraction (LVEF), reduce global longitudinal deformation, E/e ratio (early ventricular filling and early mitral annulus velocity), soluble interleukin-1 receptor-like 1 (sST2) and high-sensitive C Reactive protein (hsCRP) levels, and increase flow-mediated dilation. Moreover, lower levels of brain natriuretic peptide (BNP) and serum norepinephrine (sNE) are reported and have a positive effect on cardiac hemodynamics. In addition, they reduce cardiac remodeling and inflammation by protecting patients from HF onset after myocardial infarction (MI). The positive effects of PUFA supplementation are associated with treatment duration and a daily dosage of 1–2 g. Therefore, both the European Society of Cardiology (ESC) and the American College of Cardiology/American Heart Association (ACC/AHA) define dietary supplementation with n-3 PUFAs as an effective therapy for reducing the risk of hospitalization and death in HF patients. In this review, we seek to highlight the most recent studies related to the effect of PUFA supplementation in HF. For that purpose, a PubMed literature survey was conducted with a focus on various in vitro and in vivo studies and clinical trials from 2015 to 2021.

MicroRNA-27b-3p downregulates FGF1 and aggravates pathological cardiac remodelling

AIMS

The heart undergoes pathological remodelling under increased stress and neuronal imbalance. MicroRNAs (miRNAs) are involved in post-transcriptional regulation of genes in cardiac physiology and pathology. However, the mechanisms underlying miRNA-mediated regulation of pathological cardiac remodelling remain to be studied. This study aimed to explore the function of endogenous microRNA-27b-3p (miR-27b-3p) in pathological cardiac remodelling.

METHODS AND RESULTS

miR-27b-3p expression was elevated in the heart of a transverse aortic constriction (TAC)-induced cardiac hypertrophy mouse model. MiR-27b-knockout mice showed significantly attenuated cardiac hypertrophy, fibrosis, and inflammation induced by two independent pathological cardiac hypertrophy models, TAC and Angiotensin II (Ang II) perfusion. Transcriptome sequencing analysis revealed that miR-27b deletion significantly downregulated TAC-induced cardiac hypertrophy, fibrosis, and inflammatory genes. We identified fibroblast growth factor 1 (FGF1) as a miR-27b-3p target gene in the heart and was upregulated in miR-27b-null mice. We found that both recombinant FGF1 (rFGF1) and inhibition of miR-27b-3p enhanced mitochondrial oxidative phosphorylation (OXPHOS) and inhibited cardiomyocyte hypertrophy. Importantly, rFGF1 administration inhibited cardiac hypertrophy and fibrosis in TAC or Ang II-induced models, and enhanced OXPHOS by activating PGC1α/β.

CONCLUSIONS

Our study demonstrated that miR-27b-3p induces pathological cardiac remodelling and suggests that inhibition of endogenous miR-27b-3p or administration of FGF1 might have the potential to suppress cardiac remodelling in a clinical setting.

TRANSLATIONAL PERSPECTIVE

MicroRNAs (miRNAs) are involved in post-transcriptional regulation of genes in cardiac physiology and pathology. However, the mechanisms underlying miRNA-mediated regulation of pathological cardiac remodelling remain to be studied. We show for the first time that miR-27b deletion attenuates cardiac hypertrophy, fibrosis, and inflammation and that rFGF1 administration inhibits cardiac hypertrophy and fibrosis in TAC- or Ang II-induced models, and enhances OXPHOS by activating PGC1α/β. Our findings suggest that miR-27b-3p and FGF1 may be potential therapeutic targets to treat conditions characterised by pathological cardiac remodelling.

Heart Metabolism in Sepsis-Induced Cardiomyopathy-Unusual Metabolic Dysfunction of the Heart

Due to the need for continuous work, the heart uses up to 8% of the total energy expenditure. Due to the relatively low adenosine triphosphate (ATP) storage capacity, the heart's work is dependent on its production. This is possible due to the metabolic flexibility of the heart, which allows it to use numerous substrates as a source of energy. Under normal conditions, a healthy heart obtains approximately 95% of its ATP by oxidative phosphorylation in the mitochondria. The primary source of energy is fatty acid oxidation, the rest of the energy comes from the oxidation of pyruvate. A failed heart is characterised by a disturbance in these proportions, with the contribution of individual components as a source of energy depending on the aetiology and stage of heart failure. A unique form of cardiac dysfunction is sepsis-induced cardiomyopathy, characterised by a significant reduction in energy production and impairment of cardiac oxidation of both fatty acids and glucose. Metabolic disorders appear to contribute to the pathogenesis of cardiac dysfunction and therefore are a promising target for future therapies. However, as many aspects of the metabolism of the failing heart remain unexplained, this issue requires further research.

Alginate oligosaccharide alleviates D-galactose-induced cardiac ageing via regulating myocardial mitochondria function and integrity in mice

Ageing is a crucial risk factor for the development of age‐related cardiovascular diseases. Therefore, the molecular mechanisms of ageing and novel anti‐ageing interventions need to be deeply studied. Alginate oligosaccharide (AOS) possesses high pharmacological activities and beneficial effects. Our study was undertaken to investigate whether AOS could be used as an anti‐ageing drug to alleviate cardiac ageing. D‐galactose (D‐gal)‐induced C57BL/6J ageing mice were established by subcutaneous injection of D‐gal (200 mg·kg^‐1·d^‐1) for 8 weeks. AOS (50, 100 and 150 mg·kg^‐1·d^‐1) were administrated intragastrically for the last 4 weeks. As a result, AOS prevented cardiac dysfunction in D‐gal‐induced ageing mice, including partially preserved ejection fraction (EF%) and fractional shortening (FS%). AOS inhibited D‐gal‐induced up‐regulation of natriuretic peptides A (ANP), brain natriuretic peptide (BNP) and ageing markers p53 and p21 in a dose‐dependent manner. To further explore the potential mechanisms contributing to the anti‐ageing protective effect of AOS, the age‐related mitochondrial compromise was analysed. Our data indicated that AOS alleviated D‐gal‐induced cardiac ageing by improving mitochondrial biogenesis, maintaining the mitochondrial integrity and enhancing the efficient removal of impaired mitochondria. AOS also decreased the ROS production and oxidative stress status, which, in turn, further inhibiting cardiac mitochondria from being destroyed. Together, these results demonstrate that AOS may be an effective therapeutic agent to alleviate cardiac ageing.

Bawei Chenxiang Wan Ameliorates Cardiac Hypertrophy by Activating AMPK/PPAR-α Signaling Pathway Improving Energy Metabolism

Bawei Chenxiang Wan (BCW), a well-known traditional Chinese Tibetan medicine formula, is effective for the treatment of acute and chronic cardiovascular diseases. In the present study, we investigated the effect of BCW in cardiac hypertrophy and underlying mechanisms. The dose of 0.2, 0.4, and 0.8 g/kg BCW treated cardiac hypertrophy in SD rat model induced by isoprenaline (ISO). Our results showed that BCW (0.4 g/kg) could repress cardiac hypertrophy, indicated by macro morphology, heart weight to body weight ratio (HW/BW), left ventricle heart weight to body weight ratio (LVW/BW), hypertrophy markers, heart function, pathological structure, cross-sectional area (CSA) of myocardial cells, and the myocardial enzymes. Furthermore, we declared the mechanism of BCW anti-hypertrophy effect was associated with activating adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor-α (PPAR-α) signals, which regulate carnitine palmitoyltransferase1β (CPT-1β) and glucose transport-4 (GLUT-4) to ameliorate glycolipid metabolism. Moreover, BCW also elevated mitochondrial DNA-encoded genes of NADH dehydrogenase subunit 1(ND1), cytochrome b (Cytb), and mitochondrially encoded cytochrome coxidase I (mt-co1) expression, which was associated with mitochondria function and oxidative phosphorylation. Subsequently, knocking down AMPK by siRNA significantly can reverse the anti-hypertrophy effect of BCW indicated by hypertrophy markers and cell surface of cardiomyocytes. In conclusion, BCW prevents ISO-induced cardiomyocyte hypertrophy by activating AMPK/PPAR-α to alleviate the disturbance in energy metabolism. Therefore, BCW can be used as an alternative drug for the treatment of cardiac hypertrophy.

Iron deficiency as therapeutic target in heart failure: a translational approach

Heart failure (HF) is a potentially debilitating condition, with a prognosis comparable to many forms of cancer. It is often complicated by anemia and iron deficiency (ID), which have been shown to even further harm patients' functional status and hospitalization risk. Iron is a cellular micronutrient that is essential for oxygen uptake and transportation, as well as mitochondrial energy production. Iron is crucially involved in electrochemical stability, maintenance of structure, and contractility of cardiomyocytes. There is mounting evidence that ID indeed hampers the homeostasis of these properties. Animal model and stem cell research has verified these findings on the cellular level, while clinical trials that treat ID in HF patients have shown promising results in improving real patient outcomes, as electromechanically compromised cardiomyocytes translate to HF exacerbations and arrhythmias in patients. In this article, we review our current knowledge on the role of iron in cardiac muscle cells, the contribution of ID to anemia and HF pathophysiology and the capacity of IV iron therapy to ameliorate the patients' arrhythmogenic profile, quality of life, and prognosis.

Myocardial Iron Overload in an Experimental Model of Sudden Unexpected Death in Epilepsy

Uncontrolled repetitive generalized tonic-clonic seizures (GTCS) are the main risk factor for sudden unexpected death in epilepsy (SUDEP). GTCS can be observed in models such as Pentylenetetrazole kindling (PTZ-K) or pilocarpine-induced Status Epilepticus (SE-P), which share similar alterations in cardiac function, with a high risk of SUDEP. Terminal cardiac arrhythmia in SUDEP can develop as a result of a high rate of hypoxic stress-induced by convulsions with excessive sympathetic overstimulation that triggers a neurocardiogenic injury, recently defined as "Epileptic Heart" and characterized by heart rhythm disturbances, such as bradycardia and lengthening of the QT interval. Recently, an iron overload-dependent form of non-apoptotic cell death called ferroptosis was described at the brain level in both the PTZ-K and SE-P experimental models. However, seizure-related cardiac ferroptosis has not yet been reported. Iron overload cardiomyopathy (IOC) results from the accumulation of iron in the myocardium, with high production of reactive oxygen species (ROS), lipid peroxidation, and accumulation of hemosiderin as the final biomarker related to cardiomyocyte ferroptosis. Iron overload cardiomyopathy is the leading cause of death in patients with iron overload secondary to chronic blood transfusion therapy; it is also described in hereditary hemochromatosis. GTCS, through repeated hypoxic stress, can increase ROS production in the heart and cause cardiomyocyte ferroptosis. We hypothesized that iron accumulation in the "Epileptic Heart" could be associated with a terminal cardiac arrhythmia described in the IOC and the development of state-potentially in the development of SUDEP. Using the aforementioned PTZ-K and SE-P experimental models, after SUDEP-related repetitive GTCS, we observed an increase in the cardiac expression of hypoxic inducible factor 1α, indicating hypoxic-ischemic damage, and both necrotic cells and hemorrhagic areas were related to the possible hemosiderin production in the PTZ-K model. Furthermore, we demonstrated for the first time an accumulation of hemosiderin in the heart in the SE-P model. These results suggest that uncontrolled recurrent seizures, as described in refractory epilepsy, can give rise to high hypoxic stress in the heart, thus inducing hemosiderin accumulation as in IOC, and can act as an underlying hidden mechanism contributing to the development of a terminal cardiac arrhythmia in SUDEP. Because iron accumulation in tissues can be detected by non-invasive imaging methods, cardiac iron overload in refractory epilepsy patients could be treated with chelation therapy to reduce the risk of SUDEP.

Efficacy of L-Carnitine for Dilated Cardiomyopathy: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

L-carnitine mediates the utilization of fatty acids and glucose in the myocardium. The potential of L-carnitine in managing dilated cardiomyopathy (DCM) in patients has been extensively reported, with additional benefits.

OBJECTIVE

This meta-analysis purposed to explore the clinical efficacy of L-carnitine therapy on DCM patients.

METHODS

We searched publications up to May 2020 from several databases including PubMed, Embase, Cochrane Library, Chinese Biomedical (CBM) database, Chinese Science and Technology Periodicals database (VIP), Chinese National Knowledge Infrastructure (CNKI) database, and Wanfang database. Subsequently, publications that met the inclusion criteria were systematically evaluated by two independent reviewers.

RESULTS

A total of 23 RCTs conducted in China with 1455 DCM patients were included in this study. In the meta-analysis, L-carnitine therapy was associated with a considerable improvement in the overall efficacy (RR = 1.28, 95% CI (1.21-1.36), P < 0.0001), left ventricular ejection fraction (LVEF) (MD = 6.16%, 95% CI (4.50, 7.83), P < 0.0001), and cardiac output (CO) (MD = 0.88 L/min, 95% CI (0.51, 1.25), P < 0.0001) as compared to the control group. Moreover, L-carnitine therapy significantly decreased left ventricular end-diastolic dimension (LVEDD) (MD = -2.53, 95% CI (-3.95, -1.12), P = 0.0005), brain natriuretic peptide (BNP) (SMD = -1.71 ng/L, 95% CI (-3.02, -0.40), P = 0.01), and the transforming growth factor-beta (TGF-β1) (MD = -56.78 ng/L, 95% CI (-66.02, -47.53), P < 0.0001).

CONCLUSIONS

L-carnitine potentially enhanced the therapeutic efficiency in DCM patients. Following weaknesses in the evidence due to low methodological quality and high clinical heterogeneity in the included studies, well-designed trials are recommended.

Potential use of ubiquinol and d-ribose in patients with heart failure with preserved ejection fraction

•Manuscript Highlights.•HFpEF is associated with reduced ATP production in the myocardium.•Ubiquinol and d-ribose both contribute to the generation of myocardial ATP.•Both ubiquinol and d-ribose are being studied as supplemental treatments for patients with HFpEF.

Alteration of cardiolipin biosynthesis and remodeling in single right ventricle congenital heart disease

Despite advances in both medical and surgical therapies, individuals with single ventricle heart disease (SV) remain at high risk for the development of heart failure (HF). However, the molecular mechanisms underlying remodeling and eventual HF in patients with SV are poorly characterized. Cardiolipin (CL), an inner mitochondrial membrane phospholipid, is critical for proper mitochondrial function, and abnormalities in CL content and composition are known in various cardiovascular disease etiologies. The purpose of this study was to investigate myocardial CL content and composition in failing and nonfailing single right ventricle (RV) samples compared with normal control RV samples, to assess mRNA expression of CL biosynthetic and remodeling enzymes, and to quantitate relative mitochondrial copy number. A cross-sectional analysis of RV myocardial tissue from 22 failing SV (SVHF), 9 nonfailing SV (SVNF), and 10 biventricular control samples (BVNF) was performed. Expression of enzymes involved in CL biosynthesis and remodeling were analyzed using RT-qPCR and relative mitochondrial DNA copy number determined by qPCR. Normal phase high-pressure liquid chromatography coupled to electrospray ionization mass spectrometry was used to quantitate total and specific CL species. While mitochondrial copy number was not significantly different between groups, total CL content was significantly lower in SVHF myocardium compared with BVNF controls. Despite having lower total CL content however, the relative percentage of the major tetralinoleoyl CL species is preserved in SVHF samples relative to BVNF controls. Correspondingly, expression of enzymes involved in CL biosynthesis and remodeling were upregulated in SVHF samples when compared with both SVNF samples and BVNF controls.NEW & NOTEWORTHY The mechanisms underlying heart failure in the single ventricle (SV) congenital heart disease population are largely unknown. In this study we identify alterations in cardiac cardiolipin metabolism, composition, and content in children with SV heart disease. These findings suggest that cardiolipin could be a novel therapeutic target in this unique population of patients.

Methylmalonic acid and vitamin B12 in patients with heart failure

OBJECTIVE

Vitamin B12 deficiency among patients with heart failure (HF) may have been underestimated. High serum levels of methylmalonic acid (MMA) have been identified in several studies as an early indicator of vitamin B12 deficiency. Furthermore, MMA seems to constitute a biomarker of oxidative stress and mitochondrial dysfunction. There are scarce data regarding vitamin B12 and MMA in patients with HF. The aim of this study was to investigate vitamin B12 and MMA serum levels in patients with HF.

METHODS

One hundred five consecutive patients admitted to our hospital with symptoms and signs of acute decompensated HF were included in the study. Demographic and clinical characteristics as well as comorbidities and medical treatment before hospital admission were recorded. Transthoracic echocardiography was performed in all patients. Blood samples were collected during the first 24 hours of hospitalization and measured for complete blood count, biochemical profile, vitamin B12, N-terminal prohormone of brain natriuretic peptide, and MMA levels. Finally, 51 healthy individuals constituted the control group.

RESULTS

A total of 43.8% of patients with HF had elevated MMA levels, but only 10.5% had overt vitamin B12 deficiency, defined as serum cobalamin levels below 189 pg/ml. Mean MMA level was higher in patients with HF than in controls (33.0 ± 9.6 vs. 19.3 ± 6.3 ng/ml; p < 0.001). This difference remained significant when adjusted for age, sex, vitamin B12, and folate serum levels and kidney function (B = 14.7 (9.6-19.7); p < 0.001). MMA levels were higher in patients with acutely decompensated chronic HF than in those with newly diagnosed acute HF (34.7 ± 10.5 vs. 30.7 ± 7.8 ng/ml; p = 0.036). Correlation analysis revealed significantly negative correlation between MMA and vitamin B12 levels only in patients without comorbidities.

CONCLUSION

Patients with HF have elevated MMA levels, independent of age, gender, HF category, or comorbidities, possibly indicating subclinical vitamin B12 deficiency. Further research is needed to investigate subclinical vitamin B12 deficiency in patients with HF and/or to clarify whether MMA constitutes a biomarker of oxidative stress.

Exploiting Cysteine Residues of SLC Membrane Transporters as Targets for Drugs

The observation that cysteine is the top gainer amino acid during evolution attracted the attention of scientists dealing with protein chemistry. The thiol group of cysteine, indeed, is a potential site for several types of reactions with variable specificity and strength. This feature proved to be promising also in the field of membrane transporters that represent boundary proteins fundamental for cell homeostasis. These proteins are classified, according to the driving force for transport, in primary or secondary active transporters. Another frequently used classification is nowadays based on phylogenesis. Two major groups are identified that take into account both criteria: the ABC and the SLC transporters, the second being much more numerous. The cellular localization of the transporters makes them very attractive for drug design. Moreover, the presence of at least one cysteine residue in all the annotated SLC transporters, so far, highlights the possibility of using the thiol (SH) residue for covalent drug targeting. Even if a delay exists in this research field due to the scarce knowledge of structure/function relationships, the setup of novel experimental tools for studying SLC proteins of plasma and organelle membranes opens an important perspective in pharmacology.