Peroxisome Proliferator-Activated Receptor-α Inhibition Protects Against Doxorubicin-Induced Cardiotoxicity in Mice

IFN-γ-STAT1-ERK Pathway Mediates Protective Effects of Invariant Natural Killer T Cells Against Doxorubicin-Induced Cardiomyocyte Death

Doxorubicin (DOX)-induced cardiomyopathy has poor prognosis, and myocardial inflammation is intimately involved in its pathophysiology. The role of invariant natural killer T (iNKT) cells has not been fully determined in this disease. We here demonstrated that activation of iNKT cells by α-galactosylceramide (GC) attenuated DOX-induced cardiomyocyte death and cardiac dysfunction. αGC increased interferon (IFN)-γ and phosphorylation of signal transducers and activators of transcription 1 (STAT1) and extracellular signal-regulated kinase (ERK). Administration of anti-IFN-γ neutralizing antibody abrogated the beneficial effects of αGC on DOX-induced cardiac dysfunction. These findings emphasize the protective role of iNKT cells in DOX-induced cardiomyopathy via the IFN-γ-STAT1-ERK pathway.

The Key Molecular Mechanisms of Sini Decoction Plus Ginseng Soup to Rescue Acute Liver Failure: Regulating PPARα to Reduce Hepatocyte Necroptosis?

Purpose

This study aimed to investigate the improvement effect of Sini Decoction plus Ginseng Soup (SNRS) on the LPS/D-GalN-induced acute liver failure (ALF) mouse model and the molecular mechanism of the SNRS effect.

Methods

To study the protective effect of SNRS on ALF mice, the ICR mice were firstly divided into 4 groups: Control group (vehicle-treated), Model group (LPS/D-GalN), SNRS group (LPS/D-GalN+SNRS), and Silymarin group (LPS/D-GalN+Silymarin), the therapeutic drug was administered by gavage 48h, 24h before, and 10 min after LPS/D-GalN injection. On this basis, the peroxisome proliferator-activated receptor (PPAR) α agonist (WY14643) and inhibitor (GW6471) were added to verify whether the therapeutic mechanism of SNRS is related to its promoting effect on PPARα. The animals are grouped as follows: Control group (vehicle-treated), Model group (LPS/D-GalN+DMSO), SNRS group (LPS/D-GalN+SNRS+DMSO), Inhibitor group (LPS/D-GalN+GW6471), Agonist group (LPS/D-GalN+WY14643), and Inhibitor+SNRS group (LPS/D-GalN+GW6471+SNRS).

Results

The protective effect of SNRS on the ALF model is mainly reflected in the reduction of serum alanine aminotransaminase (ALT) and aspartate aminotransaminase (AST) as well as the ameliorated pathology of the liver tissue. The survival rate of ALF mice treated with SNRS was significantly increased. Further mechanism studies showed that SNRS significantly promoted the protein expression of PPARα and decreased the expression of necroptosis proteins (RIP3, MLKL, p-MLKL) in ALF mice. Reduced necroptosis resulted in decreased HMGB1 release, which in turn inhibited the activation of TLR4-JNK and NLRP3 inflammasome signaling pathways and the expression of NF-κB protein induced by LPS/D-GalN. The expression of CPT1A, a key enzyme involved in fatty acid β-oxidation, was found to be significantly up-regulated in the SNRS treated group, accompanied by an increased adenosine-triphosphate (ATP) level, which may be the relevant mechanism by which SNRS reduces necroptosis.

Conclusion

The potential therapeutic effect of SNRS on ALF may be through promoting the expression of PPARα and increasing the level of ATP in liver tissue, thereby inhibiting necroptosis of hepatocytes, reducing hepatocyte damage, and improving liver function.

Oleoylethanolamide as a New Therapeutic Strategy to Alleviate Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX) is one of the most common chemotherapeutic anti-cancer drugs. However, its clinical use is restricted by serious cardiotoxicity. Oleoylethanolamide (OEA), a structural congener of endocannabinoid anandamide, is the endogenous agonist of peroxisome proliferator activated-receptor α (PPARα) and transient receptor potential cation channel vanilloid-1 (TRPV1), and involved in many physiological processes. The present study aimed to determine whether OEA treatment protects against DOX-induced cytotoxicity (DIC) and gain insights into the underlying mechanism that mediate these effects. Our data revealed that Oleoylethanolamide treatment improved the myocardial structure in DOX-challenged mice by attenuating cardiac oxidative stress and cell apoptosis. OEA also alleviated DOX-induced oxidative stress and apoptosis dysregulation in HL-1 cardiomyocyte. These effects were mediated by activation of TRPV1 and upregulation of PI3K/ Akt signaling pathway. Inhibition of TRPV1 and PI3K reversed the protective effects of OEA. Taken together, our data suggested that OEA protects against DIC through a TRPV1- mediated PI3K/ Akt pathway.

Beneficial and harmful effects of CB1 and CB2 receptor antagonists on chronotropic and inotropic effects related to atrial β-adrenoceptor activation in humans and in rats with primary hypertension

We have previously shown that cannabinoid CB1 and CB2 receptor antagonists, AM251 and AM630, respectively, modulate cardiostimulatory effects of isoprenaline in atria of Wistar rats. The aim of the present study was to examine whether such modulatory effects can also be observed (a) in the human atrium and (b) in spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY). Inotropic effects of isoprenaline and/or CGP12177 (that activate the high- and low-affinity site of β1 -adrenoceptors, respectively) were examined in paced human atrial trabeculae and rat left atria; chronotropic effects were studied in spontaneously beating right rat atria. AM251 modified cardiostimulatory effects more strongly than AM630. Therefore, AM251 (1 μM) enhanced the chronotropic effect of isoprenaline in WKY and SHR as well as inotropic action of isoprenaline in WKY and in human atria. It also increased the inotropic influence of CGP12177 in SHR. AM630 (1 μM) decreased the inotropic effect of isoprenaline and CGP12177 in WKY, but enhanced the isoprenaline-induced inotropic effect in SHR and human atria. Furthermore, AM251 (0.1 and 3 μM) and AM630 (0.1 μM) reduced the inotropic action of isoprenaline in human atria. In conclusion, cannabinoid receptor antagonists have potentially harmful and beneficial effects through their amplificatory effects on β-adrenoceptor-mediated positive chronotropic and inotropic actions, respectively.

WIN 55,212-2 shows anti-inflammatory and survival properties in human iPSC-derived cardiomyocytes infected with SARS-CoV-2

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which can infect several organs, especially impacting respiratory capacity. Among the extrapulmonary manifestations of COVID-19 is myocardial injury, which is associated with a high risk of mortality. Myocardial injury, caused directly or indirectly by SARS-CoV-2 infection, can be triggered by inflammatory processes that lead to damage to the heart tissue. Since one of the hallmarks of severe COVID-19 is the "cytokine storm", strategies to control inflammation caused by SARS-CoV-2 infection have been considered. Cannabinoids are known to have anti-inflammatory properties by negatively modulating the release of pro-inflammatory cytokines. Herein, we investigated the effects of the cannabinoid agonist WIN 55,212-2 (WIN) in human iPSC-derived cardiomyocytes (hiPSC-CMs) infected with SARS-CoV-2. WIN did not modify angiotensin-converting enzyme II protein levels, nor reduced viral infection and replication in hiPSC-CMs. On the other hand, WIN reduced the levels of interleukins six, eight, 18 and tumor necrosis factor-alpha (TNF-α) released by infected cells, and attenuated cytotoxic damage measured by the release of lactate dehydrogenase (LDH). Our findings suggest that cannabinoids should be further explored as a complementary therapeutic tool for reducing inflammation in COVID-19 patients.

Anthracycline Associated Disturbances of Cardiovascular Homeostasis

Despite the dynamic progress of modern medicine, oncological and cardiovascular diseases (CVD) remain a severe economic burden worldwide. Therefore, the study of chemotherapeutic cardiotoxicity appears to be comprehensively demanded. Nowadays, pharmacological therapy in oncology has undoubtedly unprecedented development, but at the same time, the rates of cardiovascular complications of chemotherapy still remain unchanged. The well-established and highly effective, but at the same time, cardiotoxic anthracyclines have not lost their relevance. Furthermore, they remain indispensable components of an immense amount of chemotherapy regimens, such as AC, FAC, etc. Moreover, the anthracycline-containing chemotherapy regimens have become a standard of care in several cancer types. In the context of the above mentioned, the study of the pathophysiological mechanisms, biochemical aspects, and dynamics of the morphological remodeling of doxorubicin-induced cardiovascular homeostasis disturbances will enable finding new targets of pharmacological therapy, which either in the short or long perspectives, will have a beneficial effect, improving both the quality of life and prognosis of oncological patients. This article covers a versatile overview of the molecular mechanisms of doxorubicin-induced cardiotoxicity. The pathogenesis of cardiotoxicity assessment could help to explore specific molecular mechanisms that initiate cardiovascular alteration that may favorably affect the future development of targeted drugs that could prevent cardiovascular events in cancer patients.

[Molecular mechanisms of the cardiotoxic action of anthracycline antibiotics and statin-induced cytoprotective reactions of cardiomyocytes]

The manifestation of the side cardiotoxic effect of anthracycline antibiotics limits their use in the treatment of malignant processes in some patients. The review analyzes the main causes of the susceptibility of cardiomyocytes to the damaging effect of anthracyclines, primarily associated with an increase in the processes of free radical oxidation. Currently, research is widely carried out to find ways to reduce anthracycline cardiotoxicity, in particular, the use of cardioprotective agents in the complex treatment of tumors. Hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) have been shown to improve the function and metabolism of the cardiovascular system under various pathological impacts, therefore, it is proposed to use them to reduce cardiotoxic complications of chemotherapy. Statins exhibit direct (hypolipidemic) and pleiotropic effects due to the blockade of mevalonic acid synthesis and downward biochemical cascades that determine their cardioprotective properties. The main point of intersection of the pharmacological activity of anthracyclines and statins is the ability of both to regulate the functioning of small GTPase from the Rho family, and their effect in this regard is the opposite. The influence of statins on the modification and membrane dislocation of Rho proteins mediates the indirect antioxidant, anti-inflammatory, endothelioprotective, antiapoptotic effect. The mechanism of statin inhibition of doxorubicin blockade of the DNA-topoisomerase complex, which may be important in preventing cardiotoxic damage during chemotherapy, is discussed. At the same time, it should be noted that the use of statins can be accompanied by adverse side effects: a provocation of increased insulin resistance and glucose tolerance, which often causes them to be canceled in patients with impaired carbohydrate metabolism, so further studies are needed here. The review also analyzes data on the antitumor effect of statins, their ability to sensitize the tumor to treatment with cytostatic drug. It has been shown that the relationship between anthracycline antibiotics and statins is characterized not only by antagonism, but also in some cases by synergism. Despite some adverse effects, statins are one of the most promising cardio- and vasoprotectors for use in anthracycline cardiomyopathy.

The Cardioprotective Role of Flaxseed in the Prevention of Doxorubicin- and Trastuzumab-Mediated Cardiotoxicity in C57BL/6 Mice

BACKGROUND

Although the combination of doxorubicin (DOX) and trastuzumab (TRZ) reduces the progression and recurrence of breast cancer, these anticancer drugs are associated with significant cardiotoxic side effects.

OBJECTIVE

We investigated whether prophylactic administration of flaxseed (FLX) and its bioactive components, α-linolenic acid (ALA) and secoisolariciresinol diglucoside (SDG), would be cardioprotective against DOX + TRZ-mediated cardiotoxicity in a chronic in vivo female murine model.

METHODS

Wild-type C57BL/6 female mice (10-12 wk old) received daily prophylactic treatment with one of the following diets: 1) regular control (RC) semi-purified diet; 2) 10% FLX diet; 3) 4.4% ALA diet; or 4) 0.44% SDG diet for a total of 6 wks. Within each arm, mice received 3 weekly injections of 0.9% saline or a combination of DOX [8 mg/(kg.wk)] and TRZ [3 mg/(kg.wk)] starting at the end of week 3. The main outcome was to evaluate the effects of FLX, ALA, and SDG on cardiovascular remodeling and markers of apoptosis, inflammation, and mitochondrial dysfunction. Significance between measurements was determined using a 4 (diet) × 2 (chemotherapy) × 2 (time) mixed factorial design with repeated measures.

RESULTS

In the RC + DOX + TRZ-treated mice at week 6 of the study, the left ventricular ejection fraction (LVEF) decreased by 50% compared with the baseline LVEF (P < 0.05). However, the prophylactic administration of the FLX, ALA, or SDG diet was partially cardioprotective, with mice in these treatment groups showing an ∼68% increase in LVEF compared with the RC + DOX + TRZ-treated group at week 6 (P < 0.05). Although markers of inflammation (nuclear transcription factor κB), apoptosis [poly (ADP-ribose) polymerase-1 and the ratio of BCL2-associated X protein to B-cell lymphoma-extra large], and mitochondrial dysfunction (BCL2-interacting protein 3) were significantly elevated by approximately 2-fold following treatment with RC + DOX + TRZ compared with treatment with RC + saline at week 6, prophylactic administration of FLX, ALA, or SDG partially downregulated these signaling pathways.

CONCLUSION

In a chronic in vivo female C57BL/6 mouse model of DOX + TRZ-mediated cardiotoxicity, FLX, ALA, and SDG were partially cardioprotective.

Glycyrrhiza glabra (Licorice) root extract attenuates doxorubicin-induced cardiotoxicity via alleviating oxidative stress and stabilising the cardiac health in H9c2 cardiomyocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Doxorubicin (DOX) is an effective anti-neoplastic drug, however; it has downside effects on cardiac health and other vital organs. The herbal remedies used in day to day life may have a beneficial effect without disturbing the health of the vital organs. Glycyrrhiza glabra L. is a ligneous perennial shrub belonging to Leguminosae/Fabaceae/Papilionaceae family growing in Mediterranean region and Asia and widespread in Turkey, Italy, Spain, Russia, Syria, Iran, China, India and Israel. Commonly known as mulaithi in north India, G. glabra has glycyrrhizin, glycyrrhetic acid, isoliquiritin, isoflavones, etc., which have been reported for several pharmacological activities such as anti-demulcent, anti-ulcer, anti-cancer, anti-inflammatory and anti-diabetic.

AIM OF THE STUDY

The objective of the present study is to investigate the interaction between the molecular factors like PPAR-α/γ and SIRT-1 during cardiac failure arbitrated by DOX under in vitro conditions and role of Glycyrrhiza glabra (Gg) root extract in alleviating these affects.

MATERIALS AND METHODS

In the present study, we have examined the DOX induced responses in H9c2 cardiomyocytes and investigated the role of phytochemical Glycyrrhiza glabra in modulating these affects. MTT assay was done to evaluate the cell viability, Reactive Oxygen Species (ROS)/Reactive Nitrogen Species (RNS) levels, mitochondrial ROS, mitochondrial membrane potential was estimated using fluorescent probes. The oxidative stress in terms of protein carbonylation, lipid peroxidation and DNA damage was detected via spectrophotometric methods and immune-fluorescence imaging. The cardiac markers and interaction between SIRT-1 and PPAR-α/γ was measured using Real-Time PCR, Western blotting and Co-immunoprecipitation based studies.

RESULTS

The Glycyrrhiza glabra (Gg) extracts maintained the membrane integrity and improved the lipid homeostasis and stabilized cytoskeletal element actin. Gg phytoextracts attenuated aggravated ROS level, repaired the antioxidant status and consequently, assisted in repairing the DNA damage and mitochondrial function. Further, the expression of hypertrophic markers in the DOX treated cardiomyocytes reconciled the expression factors both at the transcriptional and translational levels after Gg treatment. SIRT-1 mediated pathway and its downstream activator PPARs are significant in maintaining the cellular functions. It was observed that the Gg extract allows regaining the nuclear SIRT-1 and PPAR-γ level which was otherwise reduced with DOX treatment in H9c2 cardiomyocytes. The co-immunoprecipitation (Co-IP) documented that SIRT-1 interacts with PPAR-α in the untreated control H9c2 cardiomyocytes whereas DOX treatment interferes and diminishes this interaction however the Gg treatment maintains this interaction. Knocking down SIRT-1 also downregulated expression of PPAR-α and PPAR-γ in DOX treated cells and Gg treatment was able to enhance the expression of PPAR-α and PPAR-γ in SIRT-1 knocked down cardiomyocytes.

CONCLUSIONS

The antioxidant property of Gg defend the cardiac cells against the DOX induced toxicity via; 1) reducing the oxidative stress, 2) maintaining the mitochondrial functions, 3) regulating lipid homeostasis and cardiac metabolism through SIRT-1 pathway, and 4) conserving the cardiac hypertrophy and hence preserving the cardiomyocytes health. Therefore, Gg can be recommended as a healthy supplement with DOX towards cancer therapeutics associated cardiotoxicity.

Modulation of the Endocannabinoid System as a Potential Anticancer Strategy

Currently, the involvement of the endocannabinoid system in cancer development and possible options for a cancer-regressive effect of cannabinoids are controversially discussed. In recent decades, a number of preclinical studies have shown that cannabinoids have an anticarcinogenic potential. Therefore, especially against the background of several legal simplifications with regard to the clinical application of cannabinoid-based drugs, an extended basic knowledge about the complex network of the individual components of the endocannabinoid system is required. The canonical endocannabinoid system consists of the endocannabinoids N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol as well as the G_i/o protein-coupled transmembrane cannabinoid receptors CB₁ and CB₂. As a result of extensive studies on the broader effect of these factors, other fatty acid derivatives, transmembrane and intracellular receptors, enzymes and lipid transporters have been identified that contribute to the effect of endocannabinoids when defined in the broad sense as “extended endocannabinoid system.” Among these additional components, the endocannabinoid-degrading enzymes fatty acid amide hydrolase and monoacylglycerol lipase, lipid transport proteins of the fatty acid-binding protein family, additional cannabinoid-activated G protein-coupled receptors such as GPR55, members of the transient receptor family, and peroxisome proliferator-activated receptors were identified as targets for possible strategies to combat cancer progression. Other endocannabinoid-related fatty acids such as 2-arachidonoyl glyceryl ether, O-arachidonoylethanolamine, N-arachidonoyldopamine and oleic acid amide showed an effect via cannabinoid receptors, while other compounds such as endocannabinoid-like substances exert a permissive action on endocannabinoid effects and act via alternative intracellular target structures. This review gives an overview of the modulation of the extended endocannabinoid system using the example of anticancer cannabinoid effects, which have been described in detail in preclinical studies.

Clinical application of three-dimensional speckle tracking imaging in evaluating left ventricular function in patients with gastric cancer after anthracycline chemotherapy

AIM

To assess the clinical application of three-dimensional speckle tracking imaging (3DSTI) in evaluating left ventricular function in patients with gastric cancer (GC) after anthracycline chemotherapy.

METHODS

Thirty-five patients with GC who received anthracycline chemotherapy (ECF-L) after operation were selected as subjects (chemotherapy group). Routine echocardiography and 3DSTI were performed before and after the second, fourth, and sixth cycles of chemotherapy. The left ventricular function parameters before and after chemotherapy were compared. Meanwhile, 30 healthy volunteers were selected as a control group.

RESULTS

The left ventricular global longitudinal strain (GLS) and global area strain (GAS) after the fourth and sixth cycles of chemotherapy in the chemotherapy group were significantly lower than those in the control group and those before and after the second cycles of chemotherapy (P < 0.05). Compared with the control group, no significant difference was noted in left ventricular fractional shortening (LVFS), left ventricular ejection fraction (LVEF), global circular strain (GCS), or global radial strain (GRS) in patients before and after the second, fourth, and sixth cycles of chemotherapy (P > 0.05).

CONCLUSION

3DSTI can effectively monitor the early impairment of left ventricular function in GC patients after anthracycline chemotherapy, and the sensitivities of GAS and GLS parameters are higher, which can provide a reference for clinical treatment.

WY14643 Attenuates the Scopolamine-Induced Memory Impairments in Mice

WY14643 is a selective agonist of peroxisome proliferator-activated receptor-α (PPAR-α) with neuroprotective and neurotrophic effects. The aim of this study was to evaluate the effects of WY14643 on cognitive impairments induced by scopolamine, a muscarinic acetylcholine receptor antagonist. We conducted different behavior tests including the Y-maze, Morris water maze, and passive avoidance test to measure the cognitive functions of C57BL/6J mice after scopolamine and WY14643 treatment. It was found that WY14643 injection significantly attenuated the scopolamine-induced cognitive impairments in these behavioral tests. Moreover, WY14643 treatment significantly enhanced the expression of brain-derived neurotrophic factor (BDNF) signaling cascade in the hippocampus. The usage of both PPAR-α inhibitor GW6471 and BDNF system inhibitor K252a fully prevented the memory-enhancing effects of WY14643. Therefore, these findings suggest that WY14643 could improve the scopolamine-induced memory impairments, and these effects are mediated by the activation of PPAR-α and BDNF system, thereby exhibiting a cognition-enhancing potential.

An update on PPAR activation by cannabinoids

Some cannabinoids activate the different isoforms of PPARs (α, β and γ), as shown through the use of reporter gene assays, binding studies, selective antagonists and knockout studies. Activation of all isoforms, but primarily PPARα and γ, mediates some (but not all) of the analgesic, neuroprotective, neuronal function modulation, anti-inflammatory, metabolic, anti-tumour, gastrointestinal and cardiovascular effects of some cannabinoids, often in conjunction with activation of the more traditional target sites of action such as the cannabinoid CB1 and CB2 receptors and the TRPV1 ion channel. PPARs also mediate some of the effects of inhibitors of endocannabinoid degradation or transport. Cannabinoids may be chaperoned to the PPARs by fatty acid binding proteins. The aims of this review are to update the evidence supporting PPAR activation by cannabinoids and to review the physiological responses to cannabinoids that are mediated, and not mediated, by PPAR activation.