CTRP3 protected against doxorubicin-induced cardiac dysfunction, inflammation and cell death via activation of Sirt1

Betaine alleviates doxorubicin-related cardiotoxicity via suppressing oxidative stress and inflammation via the NLRP3/SIRT1 pathway

Cardiotoxicity is one of the side effects of the anti-cancer drug doxorubicin (DOX) that limits its clinical application. Betaine (BT) is a natural agent with promising useful effects against inflammation and oxidative stress (OS). We assessed the effects of BT on DOX-induced cardiotoxicity in mice. Forty-two male NMRI mice were assigned to six groups: I: control; II: BT (200 mg/kg; orally, alone); III: DOX (2.5 mg/kg; six injections (ip)) for two weeks; IV, V, VI: BT (50 mg/kg, 100 mg/kg, and 200 mg/kg; orally, once a day for two weeks, respectively) plus DOX administration. The cardiac enzymes like cardiac troponin-I (cTn-I), lactate dehydrogenase (LDH), and creatine kinase-MB (CK-MB) were assessed in serum. Oxidative/inflammatory markers like nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), reduced glutathione level (GSH), and glutathione peroxidase (GPx) activities were determined in cardiac tissue. The expressions of NOD-like receptor protein 3 (NLRP3), caspase-1, interleukin (IL)-1β, and silent information regulator 1 (SIRT1) proteins were also evaluated in cardiac tissue. The results indicated that DOX significantly increased LDH, CK-MB, cTn-I, MDA, and NO levels and also the caspase-1, NLRP3, and IL-1β expression. Furthermore, DOX caused a significant reduction in the GSH levels and SOD, CAT, GPX activities, and the expression of SIRT1 protein in heart tissue. However, BT significantly improved all studied parameters. The findings were confirmed by histopathological assessments of the heart. BT can protect against DOX-induced cardiotoxicity by suppressing the activation of NLRP3 and OS by stimulating the SIRT1 pathway.

Triad3A-Mediated K48-Linked ubiquitination and degradation of TLR9 impairs mitochondrial bioenergetics and exacerbates diabetic cardiomyopathy

INTRODUCTION

Targeted protein degradation represents a promising therapeutic approach, while diabetic cardiomyopathy (DCM) arises as a consequence of aberrant insulin secretion and impaired glucose and lipid metabolism in the heart..

OBJECTIVES

Considering that the Toll-like receptor 9 (TLR9) signaling pathway plays a pivotal role in regulating energy metabolism, safeguarding cardiomyocytes, and influencing glucose uptake, the primary objective of this study was to investigate the impact of TLR9 on diabetic cardiomyopathy (DCM) and elucidate its underlying mechanism.

METHODS

Mouse model of DCM was established using intraperitoneal injection of STZ, and mice were transfected with adeno-associated virus serotype 9-TLR9 (AAV9-TLR9) to assess the role of TLR9 in DCM. To explore the mechanism of TLR9 in regulating DCM disease progression, we conducted interactome analysis and employed multiple molecular approaches.

RESULTS

Our study revealed a significant correlation between TLR9 expression and mouse DCM. TLR9 overexpression markedly mitigated cardiac dysfunction, myocardial fibrosis, oxidative stress, and apoptosis in DCM, while inflammation levels remained relatively unaffected. Mechanistically, TLR9 overexpression positively modulated mitochondrial bioenergetics and activated the AMPK-PGC1a signaling pathway. Furthermore, we identified Triad3A as an interacting protein that facilitated TLR9's proteasomal degradation through K48-linked ubiquitination. Inhibiting Triad3A expression improved cardiac function and pathological changes in DCM by enhancing TLR9 activity.

CONCLUSIONS

The findings of this study highlight the critical role of TLR9 in maintaining cardiac function and mitigating pathological alterations in diabetic cardiomyopathy. Triad3A-mediated regulation of TLR9 expression and function has significant implications for understanding the pathogenesis of DCM. Targeting TLR9 and its interactions with Triad3A may hold promise for the development of novel therapeutic strategies for diabetic cardiomyopathy. Further research is warranted to fully explore the therapeutic potential of TLR9 modulation in the context of cardiovascular diseases.

Research progress on the role and mechanism of Sirtuin family in doxorubicin cardiotoxicity

BACKGROUND

Doxorubicin (DOX) is a widely utilized anthracycline chemotherapy drug in cancer treatment, yet its efficacy is hindered by both short-term and long-term cardiotoxicity. Although oxidative stress, inflammation and mitochondrial dysfunction are established factors in DOX-induced cardiotoxicity, the precise molecular pathways remain elusive. Further exploration of the pathogenesis and identification of novel molecular targets are imperative. Recent studies have implicated the Sirtuins family in various physiological and pathological processes, suggesting their potential in ameliorating DOX-induced cardiotoxicity. Moreover, research on Sirtuins has discovered small-molecule compounds or medicinal plants with regulatory effects, representing a notable advancement in preventing and treating DOX-induced cardiac injury.

PURPOSE

In this review, we delve into the pathogenesis of DOX-induced cardiotoxicity and explore the therapeutic effects of Sirtuins in mitigating this condition, along with the associated molecular mechanisms. Furthermore, we delineate the roles and mechanisms of small-molecule regulators of Sirtuins in the prevention and treatment of DOX-induced cardiotoxicity.

STUDY-DESIGN/METHODS

Data for this review were sourced from various scientific databases (such as Web of Science, PubMed and Science Direct) up to March 2024. Search terms included "Sirtuins," "DOX-induced cardiotoxicity," "DOX," "Sirtuins regulators," "histone deacetylation," among others, as well as several combinations thereof.

RESULTS

Members of the Sirtuins family regulate both the onset and progression of DOX-induced cardiotoxicity through anti-inflammatory, antioxidative stress and anti-apoptotic mechanisms, as well as by maintaining mitochondrial stability. Moreover, natural plant-derived active compounds such as Resveratrol (RES), curcumin, berberine, along with synthetic small-molecule compounds like EX527, modulate the expression and activity of Sirtuins.

CONCLUSION

The therapeutic role of the Sirtuins family in mitigating DOX-induced cardiotoxicity represents a potential molecular target. However, further research is urgently needed to elucidate the relevant molecular mechanisms and to assess the safety and biological activity of Sirtuins regulators. This review offers an in-depth understanding of the therapeutic role of the Sirtuins family in mitigating DOX-induced cardiotoxicity, providing a preliminary basis for the clinical application of Sirtuins regulators in this condition.

SIRT6 activates PPARα to improve doxorubicin-induced myocardial cell aging and damage

The Sirtuins family, formally known as the Silent Information Regulator Factors, constitutes a highly conserved group of histone deacetylases. Recent studies have illuminated SIRT6's role in doxorubicin (DOX)-induced oxidative stress and apoptosis within myocardial cells. Nevertheless, the extent of SIRT6's impact on DOX-triggered myocardial cell aging and damage remains uncertain, with the associated mechanisms yet to be fully understood. In our research, we examined the influence of SIRT6 on DOX-induced cardiomyocyte senescence using β-galactosidase and γ-H2AX staining. Additionally, we gauged the mRNA expression of senescence-associated genes, namely p16, p21, and p53, through Real-time PCR. Employing ELISA assay kits, MDA, and total SOD activity assay kits, we measured inflammatory factors TNF-α, IL-6, and IL-1β, alongside oxidative stress-related indicators. The results unequivocally indicated that SIRT6 overexpression robustly inhibited DOX-induced cardiomyocyte senescence. Furthermore, we established that SIRT6 overexpression suppressed the inflammatory response and oxidative stress induced by DOX in cardiomyocytes. Conversely, silencing SIRT6 exacerbated DOX-induced cardiomyocyte injury. Our investigations further unveiled that SIRT6 upregulated the expression of genes CD36, CPT1, LCAD, MCAD associated with fatty acid oxidation through its interaction with PPARα, thereby exerting anti-aging effects. In vivo, the overexpression of SIRT6 was observed to restore DOX-induced declines in EF and FS to normal levels in mice. Echocardiography and HE staining revealed the restoration of cardiomyocyte alignment, affording protection against DOX-induced myocardial senescence and injury. The findings from this study suggest that SIRT6 holds significant promise as a therapeutic target for mitigating DOX-induced cardiomyopathy.

Matrine attenuating cardiomyocyte apoptosis in doxorubicin-induced cardiotoxicity through improved mitochondrial membrane potential and activation of mitochondrial respiratory chain Complex I pathway

The study aimed to demonstrate that matrine can reduce apoptosis in H9c2 cells induced by the cardiotoxic anticancer drug doxorubicin (DOX).The researchers pretreated H9c2 cells with different concentrations of matrine before exposing them to DOX and cultured them for 24 h. They assessed cell survival rates using cell counting kit-8 and MTT assay. Hoechst 33258 dye kits were used to determine apoptosis, while laser confocal JC-1 method was applied to test the mitochondrial membrane potential (MMP). Complex I activities were detected following the manufacturer's protocol. The results indicated that matrine pretreatment significantly increased the survival rate of H9c2 cells injured by DOX. Additionally, matrine reduced apoptosis in H9c2 cells through the improvement of MMP and activity of Complex I, which were damaged by DOX.

CTRP3 alleviates mitochondrial dysfunction and oxidative stress injury in pathological cardiac hypertrophy by activating UPRmt via the SIRT1/ATF5 axis

Pathological cardiac hypertrophy is an independent risk factor for heart failure. Disruption of mitochondrial protein homeostasis plays a key role in pathological cardiac hypertrophy; however, the mechanism of maintaining mitochondrial homeostasis in pathological cardiac hypertrophy remains unclear. In this study, we investigated the regulatory mechanisms of mitochondrial protein homeostasis in pathological cardiac hypertrophy. Wildtype (WT) mice, knockout mice, and mice transfected with lentivirus overexpressing mouse C1q-tumor necrosis factor-related protein-3 (CTRP3) underwent transverse aortic constriction or sham surgery. After 4 weeks, cardiac function, mitochondrial function, and oxidative stress injury were examined. For mechanistic studies, neonatal rat cardiomyocytes were treated with small interfering RNA or overexpression plasmids for the relevant genes. CTRP3 overexpression attenuated transverse aortic constriction (TAC) induced pathological cardiac hypertrophy, mitochondrial dysfunction, and oxidative stress injury compared to that in WT mice. TAC or Ang II resulted in compensatory activation of UPRmt, but this was not sufficient to counteract pathologic cardiac hypertrophy. CTRP3 overexpression further induced activation of UPRmt during pathologic cardiac hypertrophy and thereby alleviated pathologic cardiac hypertrophy, whereas CTRP3 knockout or knockdown inhibited UPRmt. ATF5 was a key regulatory molecule of UPRmt, as ATF5 knockout prevented the cardioprotective effect of CTRP3 in TAC mice. In vitro, SIRT1 was identified as a possible downstream CTRP3 effector molecule, and SIRT1 knockout blocked the cardioprotective effects of CTRP3. Our results also suggest that ATF5 may be regulated by SIRT1. Our study demonstrates that CTRP3 activates UPRmt via the SIRT1/ATF5 axis under pathological myocardial hypertrophy, thus attenuating mitochondrial dysfunction and oxidative stress injury.

Clinical Significance of Serum CTRP3 Level in the Prediction of Cardiac and Intestinal Mucosal Barrier Dysfunction in Patients with Severe Acute Pancreatitis

C1q/tumor necrosis factor-related protein 3 (CTRP3) has been demonstrated to play a protective role in mice with severe acute pancreatitis (SAP). However, its clinical significance in SAP remains unknown. This study was conducted to explore the clinical values of serum C1q/tumor necrosis factor-related protein 3 (CTRP3) level in the diagnosis of cardiac dysfunction (CD) and intestinal mucosal barrier dysfunction (IMBD) in SAP. Through RT-qPCR, we observed decreased CTRP3 level in the serum of SAP patients. Serum CTRP3 level was correlated with C-reactive protein, procalcitonin, creatine, modified computed tomography severity index score, and Acute Physiology and Chronic Health Evaluation II score. The receiver-operating characteristic curve revealed that CTRP3 serum level < 1.005 was conducive to SAP diagnosis with 72.55% sensitivity and 60.00% specificity, CTRP3 < 0.8400 was conducive to CD diagnosis with 80.49% sensitivity and specificity 65.57%, CTRP3 < 0.8900 was conducive to IMBD diagnosis with 94.87% sensitivity and 63.49% specificity, and CTRP3 < 0.6250 was conducive to the diagnosis of CD and IMBD co-existence with 65.22% sensitivity and 89.87% specificity. Generally, CTRP3 was downregulated in the serum of SAP patients and served as a candidate biomarker for the diagnosis of SAP and SAP-induced CD and IMBD.

Sibjotang Protects against Cardiac Hypertrophy In Vitro and In Vivo

Cardiac hypertrophy is developed by various diseases such as myocardial infarction, valve diseases, hypertension, and aortic stenosis. Sibjotang (, Shizaotang, SJT), a classic formula in Korean traditional medicine, has been shown to modulate the equilibrium of body fluids and blood pressure. This research study sought to explore the impact and underlying process of Sibjotang on cardiotoxicity induced by DOX in H9c2 cells. In vitro, H9c2 cells were induced by DOX (1 μM) in the presence or absence of SJT (1-5 μg/mL) and incubated for 24 h. In vivo, SJT was administrated to isoproterenol (ISO)-induced cardiac hypertrophy mice (n = 8) at 100 mg/kg/day concentrations. Immunofluorescence staining revealed that SJT mitigated the enlargement of H9c2 cells caused by DOX in a dose-dependent way. Using SJT as a pretreatment notably suppressed the rise in cardiac hypertrophic marker levels induced by DOX. SJT inhibited the DOX-induced ERK1/2 and p38 MAPK signaling pathways. In addition, SJT significantly decreased the expression of the hypertrophy-associated transcription factor GATA binding factor 4 (GATA 4) induced by DOX. SJT also decreased hypertrophy-associated calcineurin and NFAT protein levels. Pretreatment with SJT significantly attenuated DOX-induced apoptosis-associated proteins such as Bax, caspase-3, and caspase-9 without affecting cell viability. In addition, the results of the in vivo study indicated that SJT significantly reduced the left ventricle/body weight ratio level. Administration of SJT reduced the expression of hypertrophy markers, such as ANP and BNP. These results suggest that SJT attenuates cardiac hypertrophy and heart failure induced by DOX or ISO through the inhibition of the calcineurin/NFAT/GATA4 pathway. Therefore, SJT may be a potential treatment for the prevention and treatment of cardiac hypertrophy that leads to heart failure.

MicroRNA-495: a therapeutic and diagnostic tumor marker

Therapeutic and diagnostic progresses have significantly reduced the mortality rate among cancer patients during the last decade. However, there is still a high rate of mortality among cancer patients. One of the important reasons involved in the high mortality rate is the late diagnosis in advanced tumor stages that causes the failure of therapeutic strategies in these patients. Therefore, investigating the molecular mechanisms involved in tumor progression has an important role in introducing the efficient early detection markers. MicroRNAs (miRNAs) as stable factors in body fluids are always considered as non-invasive diagnostic and prognostic markers. In the present review, we investigated the role of miR-495 in tumor progression. It has been reported that miR-495 has mainly a tumor suppressor function through the regulation of transcription factors and tyrosine kinases as well as cellular processes such as multidrug resistance, chromatin remodeling, and signaling pathways. This review can be an effective step towards introducing the miR-495 as a non-invasive diagnostic/prognostic marker as well as a suitable target in tumor therapy.

Cinnamaldehyde alleviates doxorubicin-induced cardiotoxicity by decreasing oxidative stress and ferroptosis in cardiomyocytes

Although doxorubicin (DOX) is an efficient chemotherapeutic drug for human tumors, severe cardiotoxicity restricts its clinical use. Cinnamaldehyde (CA), a bioactive component isolated from Cinnamonum cassia, possesses potent anti-oxidative and anti-apoptotic potentials. The major aim of this study was to evaluate the protective role of CA against DOX-induced cardiotoxicity. To this end, cardiomyocyte injury models were developed using DOX-treated H9c2 cells and DOX-treated rats, respectively. Herein, we found that CA treatment increased cardiomyocyte viability and attenuated DOX-induced cardiomyocyte death in vitro. CA further protected rats against DOX-induced cardiotoxicity, as indicated by elevated creatine kinase (CK) and lactate dehydrogenase (LDH) levels, myocardium injury, and myocardial fibrosis. CA alleviated DOX-induced myocardial oxidative stress by regulating reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) levels. Mechanistically, CA markedly accelerated nuclear translocation of nuclear erythroid factor 2-related factor 2 (Nrf2) and increased heme oxygenase-1 (HO-1) expression. Consequently, CA decreased DOX-induced cardiomyocyte ferroptosis, while Erastin (a ferroptosis agonist) treatment destroyed the effect of CA on increasing cardiomyocyte viability. Taken together, the current results demonstrate that CA alleviates DOX-induced cardiotoxicity, providing a promising opportunity to increase the clinical application of DOX.

RGS7 balances acetylation/de-acetylation of p65 to control chemotherapy-dependent cardiac inflammation

Cardiotoxicity remains a major limitation in the clinical utility of anthracycline chemotherapeutics. Regulator of G-protein Signaling 7 (RGS7) and inflammatory markers are up-regulated in the hearts of patients with a history of chemotherapy particularly those with reduced left-ventricular function. RGS7 knockdown in either the murine myocardium or isolated murine ventricular cardiac myocytes (VCM) or cultured human VCM provided marked protection against doxorubicin-dependent oxidative stress, NF-κB activation, inflammatory cytokine production, and cell death. In exploring possible mechanisms causally linking RGS7 to pro-inflammatory signaling cascades, we found that RGS7 forms a complex with acetylase Tip60 and deacetylase sirtuin 1 (SIRT1) and controls the acetylation status of the p65 subunit of NF-κB. In VCM, the detrimental impact of RGS7 could be mitigated by inhibiting Tip60 or activating SIRT1, indicating that the ability of RGS7 to modulate cellular acetylation capacity is critical for its pro-inflammatory actions. Further, RGS7-driven, Tip60/SIRT1-dependent cytokines released from ventricular cardiac myocytes and transplanted onto cardiac fibroblasts increased oxidative stress, markers of transdifferentiation, and activity of extracellular matrix remodelers emphasizing the importance of the RGS7-Tip60-SIRT1 complex in paracrine signaling in the myocardium. Importantly, while RGS7 overexpression in heart resulted in sterile inflammation, fibrotic remodeling, and compromised left-ventricular function, activation of SIRT1 counteracted the detrimental impact of RGS7 in heart confirming that RGS7 increases acetylation of SIRT1 substrates and thereby drives cardiac dysfunction. Together, our data identify RGS7 as an amplifier of inflammatory signaling in heart and possible therapeutic target in chemotherapeutic drug-induced cardiotoxicity.

Columbianadin attenuates doxorubicin-induced cardiac injury, oxidative stress, and apoptosis via Sirt1/FOXO1 signaling pathway

PURPOSE

Oxidative stress and apoptosis contribute to the pathological basis of doxorubicin (DOX)-induced cardiotoxicity. Columbianadin (CBN) is one of the main bioactive constituents isolated from the root of Angelica pubescens. Herein, we intended to explore the potential role and molecular basis of CBN in DOX-induced cardiotoxicity.

METHODS

C57BL/6 mice were subjected to DOX (15 mg/kg/day, i.p.) to generate DOX-induced cardiotoxicity. CBN (10 mg/kg/day, i.p.) was administered for four week following DOX injection.

RESULTS

DOX administered markedly dampened cardiac function, increased cardiac injury, excessive reactive oxygen species (ROS) production, and cardiomyocyte loss. These alterations induced by DOX significantly alleviated by CBN treatment. Mechanistically, our results demonstrated that the CBN exerts cardioprotection role against DOX by up-regulating silent information regulator 1 (Sirt1) and decreasing acetylation of forkhead box O1 (FOXO1). Moreover, Sirt1 inhibition with Ex-527 significantly blunt the beneficial effect of CBN on DOX-induced cardiotoxicity, including cardiac dysfunction, ROS, and apoptosis.

CONCLUSION

Collectively, CBN attenuated oxidative stress and cardiomyocyte apoptosis in DOX-induced cardiotoxicity through maintaining Sirt1/FOXO1 signaling pathway. Our results demonstrated that CBN might be used to treat DOX-related cardiotoxicity.

Trastuzumab potentiates doxorubicin-induced cardiotoxicity via activating the NLRP3 inflammasome in vivo and in vitro

Trastuzumab (Tra), the first humanized monoclonal antibody that targets human epidermal growth factor receptor 2 (HER2), is commonly used alongside doxorubicin (Dox) as a combination therapy in HER2-positive breast cancer. Unfortunately, this leads to a more severe cardiotoxicity than Dox alone. NLRP3 inflammasome is known to be involved in Dox-induced cardiotoxicity and multiple cardiovascular diseases. However, whether the NLRP3 inflammasome contributes to the synergistic cardiotoxicity of Tra has not been elucidated. In this study, primary neonatal rat cardiomyocyte (PNRC), H9c2 cells and mice were treated with Dox (15 mg/kg in mice or 1μM in cardiomyocyte) or Tra (15.75 mg/kg in mice or 1μM in cardiomyocyte), or Dox combined Tra as cardiotoxicity models to investigate this question. Our results demonstrated that Tra significantly potentiated Dox-induced cardiomyocyte apoptosis and cardiac dysfunction. These were accompanied by the increased expressions of NLRP3 inflammasome components (NLRP3, ASC and cleaved caspase-1), the secretion of IL-β and the pronounced production of ROS. Inhibiting the activation of NLRP3 inflammasome by NLRP3 silencing significantly reduced cell apoptosis and ROS production in Dox combined Tra-treated PNRC. Compared with the wild type mice, the systolic dysfunction, myocardial hypertrophy, cardiomyocyte apoptosis and oxidative stress induced by Dox combined Tra were alleviated in NLRP3 gene knockout mice. Our data revealed that the co-activation of NLRP3 inflammasome by Tra promoted the inflammation, oxidative stress and cardiomyocytes apoptosis in Dox combined Tra-induced cardiotoxicity model both in vivo and in vitro. Our results suggest that NLRP3 inhibition is a promising cardioprotective strategy in Dox/Tra combination therapy.

Tisp40 prevents cardiac ischemia/reperfusion injury through the hexosamine biosynthetic pathway in male mice

The hexosamine biosynthetic pathway (HBP) produces uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) to facilitate O-linked GlcNAc (O-GlcNAc) protein modifications, and subsequently enhance cell survival under lethal stresses. Transcript induced in spermiogenesis 40 (Tisp40) is an endoplasmic reticulum membrane-resident transcription factor and plays critical roles in cell homeostasis. Here, we show that Tisp40 expression, cleavage and nuclear accumulation are increased by cardiac ischemia/reperfusion (I/R) injury. Global Tisp40 deficiency exacerbates, whereas cardiomyocyte-restricted Tisp40 overexpression ameliorates I/R-induced oxidative stress, apoptosis and acute cardiac injury, and modulates cardiac remodeling and dysfunction following long-term observations in male mice. In addition, overexpression of nuclear Tisp40 is sufficient to attenuate cardiac I/R injury in vivo and in vitro. Mechanistic studies indicate that Tisp40 directly binds to a conserved unfolded protein response element (UPRE) of the glutamine-fructose-6-phosphate transaminase 1 (GFPT1) promoter, and subsequently potentiates HBP flux and O-GlcNAc protein modifications. Moreover, we find that I/R-induced upregulation, cleavage and nuclear accumulation of Tisp40 in the heart are mediated by endoplasmic reticulum stress. Our findings identify Tisp40 as a cardiomyocyte-enriched UPR-associated transcription factor, and targeting Tisp40 may develop effective approaches to mitigate cardiac I/R injury.

Molecular mechanisms of endothelial remodeling under doxorubicin treatment

Doxorubicin (DOX) is an effective antineoplastic agent used to treat various types of cancers. However, its use is limited by the development of cardiotoxicity, which may result in heart failure. The exact mechanisms underlying DOX-induced cardiotoxicity are not fully understood, but recent studies have shown that endothelial-mesenchymal transition (EndMT) and endothelial damage play a crucial role in this process. EndMT is a biological process in which endothelial cells lose their characteristics and transform into mesenchymal cells, which have a fibroblast-like phenotype. This process has been shown to contribute to tissue fibrosis and remodeling in various diseases, including cancer and cardiovascular diseases. DOX-induced cardiotoxicity has been demonstrated to increase the expression of EndMT markers, suggesting that EndMT may play a critical role in the development of this condition. Furthermore, DOX-induced cardiotoxicity has been shown to cause endothelial damage, leading to the disruption of the endothelial barrier function and increased vascular permeability. This can result in the leakage of plasma proteins, leading to tissue edema and inflammation. Moreover, DOX can impair the production of nitric oxide, endothelin-1, neuregulin, thrombomodulin, thromboxane B2 etc. by endothelial cells, leading to vasoconstriction, thrombosis and further impairing cardiac function. In this regard, this review is devoted to the generalization and structuring of information about the known molecular mechanisms of endothelial remodeling under the action of DOX.

CTRP5 Attenuates Doxorubicin-Induced Cardiotoxicity Via Inhibiting TLR4/NLRP3 Signaling

BACKGROUND

C1q/tumor necrosis factor-related protein 5 (CTRP5) has been reported to be a crucial regulator in cardiac ischemia/reperfusion (I/R) injury. Nevertheless, the potential role of CTRP5 in doxorubicin (DOX)-induced cardiotoxicity and the potential mechanisms remain largely unclear.

METHODS

We overexpressed CTRP5 in the hearts using an adeno-associated virus 9 (AAV9) system through tail vein injection. C57BL/6 mice were subjected to DOX (15 mg/kg/day, i.p.) to generate DOX-induced cardiotoxicity for 4 weeks. Subsequently, cardiac staining and molecular biological analysis were performed to analyze the morphological and biochemical effects of CTRP5 on the cardiac injury. H9c2 cells were used for validation in vitro.

RESULTS

CTRP5 expression was down-regulated after DOX treatment both in vivo and in vitro. CTRP5 overexpression significantly attenuated DOX-induced cardiac injury, cardiac dysfunction, inhibited oxidative stress and inflammatory response. Mechanistically, CTRP5 overexpression markedly decreased the protein expression of toll-like receptor 4 (TLR4), NLRP3, cleaved caspase-1 and caspase-1, indicating TLR/NLRP3 signaling contributes to the cardioprotective role of CTRP5 in DOX-induced cardiotoxicity.

CONCLUSIONS

Together, our findings demonstrated that CTRP5 overexpression could protect the heart from oxidative stress and inflammatory injury induced by DOX through inhibiting TLR4/NLRP3 signaling, suggesting that CTRP5 might be a potential therapeutic target in the prevention of DOX-induced cardiotoxicity.

C1q/TNF-related protein 3 alleviates heart failure via attenuation of oxidative stress in myocardial infarction rats

C1q-tumor necrosis factor-related protein 3 (CTRP3), an adipokine, has been reported to be closely related to cardiovascular diseases (CVDs). However, the effect of CTRP3 on heart failure (HF) remains dimness. This study was to explore the role of CTRP3 in HF and its potential interaction mechanism. Heart failure model was established by inducing ischemia myocardial infarction (MI) through ligation of the left anterior descending artery in Sprague-Dawley rats. Four weeks later, the rats were detected by transthoracic echocardiography and masson staining. Atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), cardiac troponin I (cTnI) levels, creatine kinase-MB (CK-MB) and oxidative stress levels were recorded. The level of CTRP3 was reduced in the cardiomyocytes (CMs) treated with oxygen-glucose deprivation (OGD) and in the heart of MI rats. CTRP3 overexpression alleviated cardiac dysfunction, attenuated the cardiac fibrosis, and inhibited the increases of ANP, BNP, cTnI and CK-MB in the serum of MI rats. The increases of ANP and BNP in the CMs, and the collagen I and collagen III in the cardiac fibroblasts (CFs) induced by OGD were inhibited by CTRP3 overexpression. The enhancement of oxidative stress in the heart of MI rats was inhibited by CTRP3 overexpression. These results indicated that overexpression of CTRP3 could improve cardiac function and the related cardiac fibrosis in MI-induced HF rats via inhibition of oxidative stress. Upregulation of CTRP3 may be a strategy for HF therapy in the future.

Integration of transcriptomics, metabolomics, and lipidomics reveals the mechanisms of doxorubicin-induced inflammatory responses and myocardial dysfunction in mice

Doxorubicin (DOX) is an anthracycline antineoplastic agent that has limited clinical utility due to its dose-dependent cardiotoxicity. Although the exact mechanism remains unknown, inflammatory responses have been implicated in DOX-induced cardiotoxicity (DIC). In this study, we analyzed the transcriptomic, metabolomic as well as lipidomic changes in the DOX-treated mice to explore the underlying mechanisms of DIC. We found that continuous intraperitoneal DOX injections (3 mg/kg/d) for a period of five days significantly induced cardiac dysfunction and cardiac injury in male C57BL/6 J mice (8 weeks old). This corresponded to a significant increase in the myocardial levels of IL-4, IL-6, IL-10, IL-17 and IL-12p70. Furthermore, inflammation-related genes such as Ptgs2, Il1b, Cxcl5, Cxcl1, Cxcl2, Mmp3, Ccl2, Ccl12, Nfkbia, Fos, Mapk11 and Tnf were differentially expressed in the DOX-treated group, and enriched in the IL-17 and TNF signaling pathways. Besides, amino acids, peptides, imidazoles, toluenes, hybrid peptides, fatty acids and lipids such as Hex1Cer, Cer, SM, PG and ACCa were significantly associated with the expression pattern of inflammation-related genes. In conclusion, the integration of transcriptomic, metabolomic and lipidomic data identified potential new targets and biomarkers of DIC.

Cardioprotective potential of mitochondria-targeted antioxidant, mito-TEMPO, in 5-fluorouracil-induced cardiotoxicity

Purpose

The mitochondria-targeted antioxidants (MTAs) are known to offer protection against mitochondrial oxidative stress. The recent evidences support their role in mitigating oxidative stress-induced diseases, including cancer. Therefore, this study investigated cardioprotective potential of mito-TEMPO against 5-FU-induced cardiotoxicity.

Methods

Mito-TEMPO was administered to male BALB/C mice (intraperitoneally, 0.1 mg/kg b.w. for 7 days) followed by intraperitoneal administration of 5- FU (12 mg/kg b.w. for 4 days). During this period, mito-TEMPO treatment was also continued. The cardioprotective potential of mito-TEMPO was assessed by evaluating cardiac injury markers, extent of non-viable myocardium and histopathological alterations. Mitochondrial functional status and mitochondrial oxidative stress were assessed in cardiac tissue. 8-OHdG expression and apoptotic cell death were assessed using immunohistochemical techniques.

Results

The level of cardiac injury markers CK-MB and AST were significantly (P ≤ 0.05) decreased in mito-TEMPO pre-protected group which was further reflected in histopathology as decrease in the percentage of non-viable myocardial tissue, disorganization, and loss of myofibrils. Mito-TEMPO ameliorated mtROS, mtLPO and conserved mitochondrial membrane potential. Further, it had significantly (P ≤ 0.05) improved the activity of mitochondrial complexes and mitochondrial enzymes. A significant (P ≤ 0.05) increase in the level of mtGSH, activity of mitochondrial glutathione reductase, glutathione peroxidase, and mitochondrial superoxide dismutase was observed. A decreased expression of 8-OHdG and reduced apoptotic cell death were observed in mito-TEMPO pre-protected group.

Conclusion

Mito-TEMPO effectively mitigated 5-FU-induced cardiotoxicity by modulating mitochondrial oxidative stress, hence may serve as a protective agent/adjuvant in 5-FU-based combinatorial chemotherapy.

Melatonin alleviates doxorubicin-induced cardiotoxicity via inhibiting oxidative stress, pyroptosis and apoptosis by activating Sirt1/Nrf2 pathway

Melatonin confers cardioprotective effects on multiple cardiovascular diseases, including doxorubicin-induced cardiomyopathy. The effectiveness of melatonin in mitigating myocardial injuries caused by Doxorubicin through enhancement of mitochondrial function is already established, however, the role of melatonin in regulating the Sirtuin-1 (Sirt1)/Nuclear factor E2-associated factor 2 (Nrf2) pathway in lessening the onset of Doxorubicin-induced cardiomyopathy is yet to be elucidated. To address this, H9C2 cardiomyocytes and C57BL/6 mice were employed to construct in vitro and in vivo models of Dox-induced myocardial impairments, respectively. Results showed that Dox markedly evoked oxidative stress, pyroptosis and apoptosis both in vitro and in vivo, which were significantly alleviated by melatonin administration. Mechanistically, melatonin attenuated Dox-induced downregulation of Sirt1 and Nrf2, and both inhibition of Sirt1 and Nrf2 significantly reversed the cardioprotective effects of melatonin. In conclusion, our studies suggest that the activation of the Sirt1/Nrf2 pathway is the underlying mechanism behind melatonin's ability to curtail oxidative stress, pyroptosis, and apoptosis in Dox-induced cardiomyopathy. These promising results demonstrated the potential application of melatonin as a treatment for doxorubicin-induced cardiac injury.

Activation of the sirtuin silent information regulator 1 pathway inhibits pathological myocardial remodeling

Myocardial remodeling refers to structural and functional disorders of the heart caused by molecular biological changes in the cardiac myocytes in response to neurological and humoral factors. A variety of heart diseases, such as hypertension, coronary artery disease, arrhythmia, and valvular heart disease, can cause myocardial remodeling and eventually lead to heart failure. Therefore, counteracting myocardial remodeling is essential for the prevention and treatment of heart failure. Sirt1 is a nicotinamide adenine dinucleotide⁺-dependent deacetylase that plays a wide range of roles in transcriptional regulation, energy metabolism regulation, cell survival, DNA repair, inflammation, and circadian regulation. It positively or negatively regulates myocardial remodeling by participating in oxidative stress, apoptosis, autophagy, inflammation, and other processes. Taking into account the close relationship between myocardial remodeling and heart failure and the involvement of SIRT1 in the development of the former, the role of SIRT1 in the prevention of heart failure via inhibition of myocardial remodeling has received considerable attention. Recently, multiple studies have been conducted to provide a better understanding of how SIRT1 regulates these phenomena. This review presents the progress of research involving SIRT1 pathway involvement in the pathophysiological mechanisms of myocardial remodeling and heart failure.

Tubeimoside I Ameliorates Doxorubicin-Induced Cardiotoxicity by Upregulating SIRT3

Cardiotoxicity linked to doxorubicin (DOX) is primarily caused by inflammation, oxidative stress, and apoptosis. The role of tubeimoside I (TBM) in DOX-induced cardiotoxicity remains ambiguous, despite growing evidence that it could reduce inflammation, oxidative stress, and apoptosis in various diseases. This study was designed to investigate the role of TBM in DOX-induced cardiotoxicity and uncover the underlying mechanisms. H9c2 cell line and C57BL/6 mice were used to construct an in vitro and in vivo model of DOX-induced myocardial injury, respectively. We observed that DOX treatment provoked inflammation, oxidative stress, and cardiomyocyte apoptosis, which were significantly alleviated by TBM administration. Mechanistically, TBM attenuated DOX-induced downregulation of sirtuin 3 (SIRT3), and SIRT3 inhibition abrogated the beneficial effects of TBM both in vitro and in vivo. In conclusion, TBM eased inflammation, oxidative stress, and apoptosis in DOX-induced cardiotoxicity by increasing the expression of SIRT3, suggesting that it holds great promise for treating DOX-induced cardiac injury.

Adipokine C1q/Tumor Necrosis Factor- Related Protein 3 (CTRP3) Attenuates Intestinal Inflammation Via Sirtuin 1/NF-κB Signaling

BACKGROUND & AIMS

The adipokine CTRP3 has anti-inflammatory effects in several nonintestinal disorders. Although serum CTRP3 is reduced in patients with inflammatory bowel disease (IBD), its function in IBD has not been established. Here, we elucidate the function of CTRP3 in intestinal inflammation.

METHODS

CTRP3 knockout (KO) and overexpressing transgenic (Tg) mice, along with their corresponding wild-type littermates, were treated with dextran sulfate sodium for 6-10 days. Colitis phenotypes and histologic data were analyzed. CTRP3-mediated signaling was examined in murine and human intestinal mucosa and mouse intestinal organoids derived from CTRP3 KO and Tg mice.

RESULTS

CTRP3 KO mice developed more severe colitis, whereas CTRP3 Tg mice developed less severe colitis than wild-type littermates. The deletion of CTRP3 correlated with decreased levels of Sirtuin-1 (SIRT1), a histone deacetylase, and increased levels of phosphorylated/acetylated NF-κB subunit p65 and proinflammatory cytokines tumor necrosis factor-α and interleukin-6. Results from CTRP3 Tg mice were inverse to those from CTRP3 KO mice. The addition of SIRT1 activator resveratrol to KO intestinal organoids and SIRT1 inhibitor Ex-527 to Tg intestinal organoids suggest that SIRT1 is a downstream effector of CTRP3-related inflammatory changes. In patients with IBD, a similar CTRP3/SIRT1/NF-κB relationship was observed.

CONCLUSIONS

CTRP3 expression levels correlate negatively with intestinal inflammation in acute mouse colitis models and patients with IBD. CTRP3 may attenuate intestinal inflammation via SIRT1/NF-κB signaling. The manipulation of CTRP3 signaling, including through the use of SIRT1 activators, may offer translational potential in the treatment of IBD.

Nicotinamide Mononucleotide Administration Prevents Doxorubicin-Induced Cardiotoxicity and Loss in Physical Activity in Mice

Doxorubicin (Doxo) is a widely used antineoplastic drug with limited clinical application due to its deleterious dose-related side effects. We investigated whether nicotinamide mononucleotide (NMN) could protect against Doxo-induced cardiotoxicity and physical dysfunction in vivo. To assess the short- and long-term toxicity, two Doxo regimens were tested, acute and chronic. In the acute study, C57BL6/J (B6) mice were injected intraperitoneally (i.p.) once with Doxo (20 mg/kg) and NMN (180 mg/kg/day, i.p.) was administered daily for five days before and after the Doxo injection. In the chronic study, B6 mice received a cumulative dose of 20 mg/kg Doxo administered in fractionated doses for five days. NMN (500 mg/kg/day) was supplied in the mice's drinking water beginning five days before the first injection of Doxo and continuing for 60 days after. We found that NMN significantly increased tissue levels of NAD+ and its metabolites and improved survival and bodyweight loss in both experimental models. In addition, NMN protected against Doxo-induced cardiotoxicity and loss of physical function in acute and chronic studies, respectively. In the heart, NMN prevented Doxo-induced transcriptomic changes related to mitochondrial function, apoptosis, oxidative stress, inflammation and p53, and promyelocytic leukemia nuclear body pathways. Overall, our results suggest that NMN could prevent Doxo-induced toxicity in heart and skeletal muscle.

Exogenous 8-hydroxydeoxyguanosine attenuates doxorubicin-induced cardiotoxicity by decreasing pyroptosis in H9c2 cardiomyocytes

Doxorubicin (DOX), which is widely used in cancer treatment, can induce cardiomyopathy. One of the main mechanisms whereby DOX induces cardiotoxicity involves pyroptosis through the NLR family pyrin domain containing 3 (NLRP3) inflammasome and gasdermin D (GSDMD). Increased NAPDH oxidase (NOX) and oxidative stress trigger pyroptosis. Exogenous 8-hydroxydeoxyguanosine (8-OHdG) decreases reactive oxygen species (ROS) production by inactivating NOX. Here, we examined whether 8-OHdG treatment can attenuate DOX-induced pyroptosis in H9c2 cardiomyocytes. Exposure to DOX increased the peroxidative glutathione redox status and NOX1/2/4, toll-like receptor (TLR)2/4, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) expression, while an additional 8-OHdG treatment attenuated these effects. Furthermore, DOX induced higher expression of NLRP3 inflammasome components, including NLRP3, apoptosis-associated speck-like protein containing a c-terminal caspase recruitment domain (ASC), and pro-caspase-1. Moreover, it increased caspase-1 activity, a marker of pyroptosis, and interleukin (IL)-1β expression. All these effects were attenuated by 8-OHdG treatment. In addition, the expression of the cardiotoxicity markers, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) was increased by DOX, whereas the increase of ANP and BNP induced by DOX treatment was reversed by 8-OHdG. In conclusion, exogenous 8-OHdG attenuated DOX-induced pyroptosis by decreasing the expression of NOX1/2/3, TLR2/4, and NF-κB. Thus, 8-OHdG may attenuate DOX-induced cardiotoxicity through the inhibition of pyroptosis.

Gab1 Overexpression Alleviates Doxorubicin-Induced Cardiac Oxidative Stress, Inflammation, and Apoptosis Through PI3K/Akt Signaling Pathway

ABSTRACT

Grb2-associated binding protein 1 (Gab1), an intracellular scaffolding adaptor, was involved in several cardiovascular diseases. However, the role of Gab1 in doxorubicin (DOX)-induced cardiotoxicity remains largely unknown. The present study investigated whether Gab1 protected against DOX-induced cardiotoxicity and the underlying mechanism. We overexpressed Gab1 in the hearts using an adeno-associated virus 9 system through tail vein injection. C57BL/6 mice were subjected to DOX (15 mg/kg/d, i.p.) to generate DOX-induced cardiotoxicity. Echocardiography, histological analysis, immunofluorescence and enzyme-linked immunosorbent assay (ELISA) kits, Western blotting, and quantitative real-time polymerase chain reaction (PCR) evaluated DOX-induced cardiotoxicity and the underlying mechanisms. Myocardial Gab1 protein and messenger RNA (mRNA) levels were markedly decreased in DOX-administered mice. Overexpression of Gab1 in myocardium significantly improved cardiac function and attenuated cardiac oxidative stress, inflammatory response, and apoptosis induced by DOX. Mechanistically, we found that PI3K/Akt signaling pathway was downregulated after DOX treatment, and Gab1 overexpression activated PI3K/Akt signaling pathway, whereas PI3K/Akt signaling pathway inhibition abolished the beneficial effect of Gab1 overexpression in the heart. Collectively, our results indicated that Gab1 is essential for cardioprotection against DOX-induced oxidative stress, inflammatory response, and apoptosis by mediating PI3K/Akt signaling pathway. And cardiac gene therapy with Gab1 provides a novel therapeutic strategy against DOX-induced cardiotoxicity.

SIRT1 activation and its effect on intercalated disc proteins as a way to reduce doxorubicin cardiotoxicity

According to the World Health Organization, the neoplasm is one of the main reasons for morbidity and mortality worldwide. At the same time, application of cytostatic drugs like an independent type of cancer treatment and in combination with surgical methods, is often associated with the development of cardiovascular complications both in the early and in the delayed period of treatment. Doxorubicin (DOX) is the most commonly used cytotoxic anthracycline antibiotic. DOX can cause both acute and delayed side effects. The problem is still not solved, as evidenced by the continued activity of researchers in terms of developing approaches for the prevention and treatment of cardiovascular complications. It is known, the heart muscle consists of cardiomyocytes connected by intercalated discs (ID), which ensure the structural, electrical, metabolic unity of the heart. Various defects in the ID proteins can lead to the development of cardiovascular diseases of various etiologies, including DOX-induced cardiomyopathy. The search for ways to influence the functioning of ID proteins of the cardiac muscle can become the basis for the creation of new therapeutic approaches to the treatment and prevention of cardiac pathologies. SIRT1 may be an interesting cardioprotective variant due to its wide functional significance. SIRT1 activation triggers nuclear transcription programs that increase the efficiency of cellular, mitochondrial metabolism, increases resistance to oxidative stress, and promotes cell survival. It can be assumed that SIRT1 can not only provide a protective effect at the cardiomyocytes level, leading to an improvement in mitochondrial and metabolic functions, reducing the effects of oxidative stress and inflammatory processes, but also have a protective effect on the functioning of IDs structures of the cardiac muscle.

Critical Reanalysis of the Mechanisms Underlying the Cardiorenal Benefits of SGLT2 Inhibitors and Reaffirmation of the Nutrient Deprivation Signaling/Autophagy Hypothesis

SGLT2 (sodium-glucose cotransporter 2) inhibitors produce a distinctive pattern of benefits on the evolution and progression of cardiomyopathy and nephropathy, which is characterized by a reduction in oxidative and endoplasmic reticulum stress, restoration of mitochondrial health and enhanced mitochondrial biogenesis, a decrease in proinflammatory and profibrotic pathways, and preservation of cellular and organ integrity and viability. A substantial body of evidence indicates that this characteristic pattern of responses can be explained by the action of SGLT2 inhibitors to promote cellular housekeeping by enhancing autophagic flux, an effect that may be related to the action of these drugs to produce simultaneous upregulation of nutrient deprivation signaling and downregulation of nutrient surplus signaling, as manifested by an increase in the expression and activity of AMPK (adenosine monophosphate-activated protein kinase), SIRT1 (sirtuin 1), SIRT3 (sirtuin 3), SIRT6 (sirtuin 6), and PGC1-α (peroxisome proliferator-activated receptor γ coactivator 1-α) and decreased activation of mTOR (mammalian target of rapamycin). The distinctive pattern of cardioprotective and renoprotective effects of SGLT2 inhibitors is abolished by specific inhibition or knockdown of autophagy, AMPK, and sirtuins. In the clinical setting, the pattern of differentially increased proteins identified in proteomics analyses of blood collected in randomized trials is consistent with these findings. Clinical studies have also shown that SGLT2 inhibitors promote gluconeogenesis, ketogenesis, and erythrocytosis and reduce uricemia, the hallmarks of nutrient deprivation signaling and the principal statistical mediators of the ability of SGLT2 inhibitors to reduce the risk of heart failure and serious renal events. The action of SGLT2 inhibitors to augment autophagic flux is seen in isolated cells and tissues that do not express SGLT2 and are not exposed to changes in environmental glucose or ketones and may be related to an ability of these drugs to bind directly to sirtuins or mTOR. Changes in renal or cardiovascular physiology or metabolism cannot explain the benefits of SGLT2 inhibitors either experimentally or clinically. The direct molecular effects of SGLT2 inhibitors in isolated cells are consistent with the concept that SGLT2 acts as a nutrient surplus sensor, and thus, its inhibition causes enhanced nutrient deprivation signaling and its attendant cytoprotective effects, which can be abolished by specific inhibition or knockdown of AMPK, sirtuins, and autophagic flux.

Intravenous Nicotinamide Riboside Administration Has a Cardioprotective Effect in Chronic Doxorubicin-Induced Cardiomyopathy

Doxorubicin, which is widely used to treat a broad spectrum of malignancies, has pronounced dose-dependent side effects leading to chronic heart failure development. Nicotinamide riboside (NR) is one of the promising candidates for leveling the cardiotoxic effect. In the present work, we performed a comparative study of the cardioprotective and therapeutic actions of various intravenous NR administration modes in chronic doxorubicin-induced cardiomyopathy in Wistar rats. The study used 60 mature male SPF Wistar rats. The animals were randomized into four groups (a control group and three experimental groups) which determined the doxorubicin (intraperitoneally) and NR (intravenous) doses as well as the specific modes of NR administration (combined, preventive). We demonstrated the protective effect of NR on the cardiovascular system both with combined and preventive intravenous drug administration, which was reflected in a fibrous tissue formation decrease, reduced fractional-shortening decrease, and better antioxidant system performance. At the same time, it is important to note that the preventive administration of NR had a more significant protective effect on the animal organism as a whole. This was confirmed by better physical activity parameters and vascular bed conditions. Thus, the data obtained during the study can be used for further investigation into chronic doxorubicin-induced cardiomyopathy prevention and treatment approaches.

Resveratrol and FGF1 Synergistically Ameliorates Doxorubicin-Induced Cardiotoxicity via Activation of SIRT1-NRF2 Pathway

Doxorubicin (DOX) has received attention due to dose-dependent cardiotoxicity through abnormal redox cycling. Native fibroblast growth factor 1 (FGF1) is known for its anti-oxidative benefits in cardiovascular diseases, but possesses a potential tumorigenic risk. Coincidentally, the anti-proliferative properties of resveratrol (RES) have attracted attention as alternatives or auxiliary therapy when combined with other chemotherapeutic drugs. Therefore, the purpose of this study is to explore the therapeutic potential and underlying mechanisms of co-treatment of RES and FGF1 in a DOX-treated model. Here, various cancer cells were applied to determine whether RES could antagonize the oncogenesis effect of FGF1. In addition, C57BL/6J mice and H9c2 cells were used to testify the therapeutic potential of a co-treatment of RES and FGF1 against DOX-induced cardiotoxicity. We found RES could reduce the growth-promoting activity of FGF1. Additionally, the co-treatment of RES and FGF1 exhibits a more powerful cardio-antioxidative capacity in a DOX-treated model. The inhibition of SIRT1/NRF2 abolished RES in combination with FGF1 on cardioprotective action. Further mechanism analysis demonstrated that SIRT1 and NRF2 might form a positive feedback loop to perform the protective effect on DOX-induced cardiotoxicity. These favorable anti-oxidative activities and reduced proliferative properties of the co-treatment of RES and FGF1 provided a promising therapy for anthracycline cardiotoxicity during chemotherapy.

Long noncoding RNA TDRG1 aggravates doxorubicin-induced cardiomyopathy by binding with miR-873-5p to upregulate PRKAR2

Doxorubicin-induced cardiomyopathy (DCM) is a life-threatening event. The long noncoding RNAs (lncRNAs) have been reported with close associations with DCM, which may provide novel insight into pathophysiological mechanisms of DCM. DCM rat model and cell models were established using doxorubicin. Echocardiography analyses were performed to assess cardiac function. We found that testis developmental-related gene 1 (TDRG1) expression was upregulated in DCM rats and in doxorubicin-treated human umbilical vein endothelial cells (HUVECs). TDRG1 knockdown enhanced cell viability, promoted tube formation, and inhibited apoptosis of doxorubicin-treated HUVECs. Additionally, knockdown of TDRG1 alleviated cardiac injury in DCM rats. Mechanistically, miR-873-5p was identified to bind with TDRG1. In addition, protein kinase cAMP-dependent type II regulatory subunit alpha (PRKAR2) was confirmed to bind with miR-873-5p as a target mRNA. MiR-873-5p negatively regulated PRKAR2 mRNA and protein levels. At last, rescue assays indicated that the overexpression of PRKAR2 restored the effect of TDRG1 knockdown on doxorubicin-treated HUVEC angiogenesis and apoptosis. To conclude, TDRG1 aggravates DCM progression by binding with miR-873-5p to upregulate PRKAR2. This work suggested the potential of TDRG1 as a target for DCM treatment.

A brief overview about the adipokine: Isthmin-1

Isthmin-1 is a secreted protein with multiple capability; however, it truly attracts our attention since the definition as an adipokine in 2021, which exerts indispensable roles in various pathophysiological processes through the endocrine or autocrine manners. In this review, we summarize recent knowledge of isthmin-1, including its distribution, structure, receptor and potential function.

Mulberrin Confers Protection against Doxorubicin-Induced Cardiotoxicity via Regulating AKT Signaling Pathways in Mice

Doxorubicin (DOX) is an antitumor anthracycline, but its clinical use was largely limited by its cardiac toxicity. DOX-induced oxidative damage and cardiomyocyte loss have been recognized as the potential causative mechanisms of this cardiac toxicity. Growing interests are raised on mulberrin (Mul) for its wide spectrum of biological activities, including antioxidative and anti-inflammatory properties. The aim of this study was to investigate the effect of Mul on DOX-induced heart injury and to clarify the underlying mechanism. Mice were given daily 60 mg/kg of Mul via gavage for 10 days. Mice received an intraperitoneal injection of DOX to mimic the model of DOX-related acute cardiac injury at the seventh day of Mul treatment. Mul-treated mice had an attenuated cardiac injured response and improved cardiac function after DOX injection. DOX-induced oxidative damage, inflammation accumulation, and myocardial apoptosis were largely attenuated by the treatment of Mul. Activated protein kinase B (AKT) activation was essential for the protective effects of Mul against DOX-induced cardiac toxicity, and AKT inactivation abolished Mul-mediated protective effects against DOX cardiotoxicity. In conclusion, Mul treatment attenuated DOX-induced cardiac toxicity via activation of the AKT signaling pathway. Mul might be a promising therapeutic agent against DOX-induced cardiac toxicity.

C1q/tumour necrosis factor-related protein-3 alleviates high-glucose-induced lipid accumulation and necroinflammation in renal tubular cells by activating the adenosine monophosphate-activated protein kinase pathway

Lipid accumulation and progressive necroinflammation play pivotal roles in the development of diabetic nephropathy. C1q tumour necrosis factor-related protein-3 (CTRP3) is an adipokine with pleiotropic functions in cell proliferation, glucose and lipid metabolism, and inflammation. However, the mechanism and involvement of CTRP3 in lipid metabolism and the necroinflammation of renal tubular cells remain unclear. Here, we report that CTRP3 expression decreased in a time- and concentration-dependent manner in high glucose-stimulated HK-2 cells. We noted that the overexpression of CTRP3 or recombinant CTRP3 (rCTRP3) treatment prevented high glucose-induced lipid accumulation by inhibiting the expression of sterol regulatory element-binding protein-1 and increasing the expression of peroxisome proliferator-activated receptor-α and ATP-binding cassette A1. Moreover, the nucleotide-binding oligomerisation domain-like receptor protein 3-mediated inflammatory response and mixed lineage kinase domain-like protein-dependent necroinflammation were inhibited by CTRP3 overexpression or rCTRP3 treatment in HK-2 cells cultured in high glucose. Furthermore, lipotoxicity-induced by palmitic acid was found to be involved in necroinflammation in HK-2 cells, and CTRP3 displayed the same protective effect. CTRP3 also activated the adenosine monophosphate-activated protein kinase (AMPK) pathway, whereas adenine 9-β-D-arabinofuranoside, an AMPK inhibitor, replicated the protective effects of CTRP3. Besides, using kidney biopsies from patients with diabetes, we found that decreased CTRP3 expression was accompanied by increased lipid deposition, as well as the structural and functional injury of renal tubular cells. Our findings demonstrate that CTRP3 affects lipid metabolism and necroinflammation in renal tubular cells via the AMPK signalling pathway. Thus, CTRP3 may be a potential therapeutic target in diabetic renal injury.

Beyond hypertension: Diastolic dysfunction associated with cancer treatment in the era of cardio-oncology

Cancer patients are at an increased risk of cardiovascular events. Both old-generation cytostatics/cytotoxics and new-generation "targeted" drugs can in fact damage cardiomyocytes, endothelial cells of veins and arteries, specialized cells of the conduction system, pericardium, and valves. A new discipline, cardio-oncology, has therefore developed with the aim of protecting cancer patients from cardiovascular events, while also providing them with the best possible oncologic treatment. Anthracyclines have long been known to elicit cardiotoxicity that, depending on treatment- or patient-related factors, may progress with a variable velocity toward cardiomyopathy and systolic heart failure. However, early compromise of diastolic function may precede systolic dysfunction, and a progression of early diastolic dysfunction to diastolic rather than systolic heart failure has been documented in long-term cancer survivors. This chapter first describes general notions about hypertension in the cancer patient and then moves on reviewing the pathophysiology and clinical trajectories of diastolic dysfunction, and the molecular mechanisms of anthracycline-induced diastolic dysfunction. Diastolic dysfunction can in fact be caused and/or aggravated by hypertension. Pharmacologic foundations and therapeutic opportunities to prevent or treat diastolic dysfunction before it progresses toward heart failure are also reviewed, with a special emphasis on the mechanisms of action of drugs that raised hopes to treat diastolic dysfunction in the general population (sacubitril/valsartan, guanylyl cyclase activators, phosphodiesterase inhibitors, ranolazine, inhibitors of type-2 sodium-glucose-inked transporter). Cardio-oncologists will be confronted with the risk:benefit ratio of using these drugs in the cancer patient.

CTRP3 alleviates myocardial ischemia/reperfusion injury in mice through activating LAMP1/JIP2/JNK pathway

Myocardial ischemia reperfusion (I/R) injury is an important complication of myocardial infarction reperfusion therapy, and no effective treatment has been identified. Based on preexisting evidence, C1q/tumor necrosis factor-related protein 3 (CTRP3) has been reported to be closely associated with myocardial dysfunction. In this study, we found that CTRP3 was downregulated in acute coronary syndrome (ACS) patients and myocardial I/R mice. Silence of CTRP3 aggravated cardiac systolic function due to I/R of mice, while CTRP3 overexpression ameliorated cardiac function. Moreover, overexpression of CTRP3 improved I/R inhibitory effects on the levels of creatinine phosphokinase (CPK), lactate dehydrogenase (LDH) and cardiac troponin-I (cTn-I), myocardial infarction area, the intensity of the 3-nitrotyrosine (3-NT), apoptosis and protein levels of LAMP1, JNK-Interacting Protein-2 (JIP-2) and JNK, while these effects could be exacerbated by downregulation of CTRP3. Co-IP experiments could identify physical interactions between CTRP3 and lysosomal-associated membrane protein 1 (LAMP1) and Numb and JIP2. LAMP1 silence aggravated the inhibition effects of I/R on JIP2 and JNK protein expression, CPK, LDH and cTn-I levels and caspase-3 activity, while overexpression of LAMP1 recovered these inhibition effects of I/R. JNK inhibitor (SP600125) could reverse the inhibitory effects of CTRP3 overexpression on CPK, LDH, cTn-I, myocardial infarction, strong positive staining for 3-NT and apoptosis. These findings demonstrated that CTRP3 protected against injury caused by myocardial I/R through activating LAMP1/JIP2/JNK pathway to attenuate myocardial injury, improve left ventricular function, decrease myocardial infarction, and reduce myocardial apoptosis.

Circulating biomarkers for management of cancer therapeutics related cardiac dysfunction

Cancer therapeutics related cardiac dysfunction (CTRCD) has emerged as a major cause of morbidity and mortality in cancer survivors. Effective clinical management of CTRCD is impeded by a lack of sensitive diagnostic and prognostic strategies. Circulating molecular markers could potentially address this need as they are often indicative of cardiac stress before cardiac damage can be detected clinically. A growing understanding of the underlying physiological mechanisms for CTRCD has inspired research efforts to identify novel pathophysiologically-relevant biomarkers that may also guide development of cardio-protective therapeutic approaches. The purpose of this review is to evaluate current circulating biomarkers of cardiac stress and their potential role in diagnosis and management of CTRCD. We also discuss some emerging avenues for CTRCD-focused biomarker investigations.

Investigation of drugs for the prevention of doxorubicin-induced cardiac events using big data analysis

AIM

Doxorubicin, an anthracycline anti-tumour agent, is an essential chemotherapeutic drug; however, the adverse events associated with doxorubicin usage, including cardiotoxicity, prevent patients from continuing treatment. Here, we used databases to explore existing approved drugs with potential preventative effects against doxorubicin-induced cardiac events and examined their efficacy and mechanisms.

METHODS

The Gene Expression Omnibus (GEO), Library of Integrated Network-based Cellular Signatures (LINCS), and Food and Drug Administration Adverse Events Reporting System (FAERS) databases were used to extract candidate prophylactic drugs. Mouse models of doxorubicin-induced cardiac events were generated by intraperitoneal administration of 20 mg/kg of doxorubicin on Day 1 and oral administration of prophylactic candidate drugs for 6 consecutive days beginning the day before doxorubicin administration. On Day 6, mouse hearts were extracted and examined for mRNA expression of apoptosis-related genes.

RESULTS

GEO analysis showed that doxorubicin administration upregulated 490 genes and downregulated 862 genes, and LINCS data identified sirolimus, verapamil, minoxidil, prednisolone, guanabenz, and mosapride as drugs capable of counteracting these genetic alterations. Examination of the effects of these drugs on cardiac toxicity using FAERS identified sirolimus and mosapride as new prophylactic drug candidates. In model mice, mosapride and sirolimus suppressed the Bax/Bcl-2 mRNA ratio, which is elevated in doxorubicin-induced cardiotoxicity. These drugs also suppressed the expression of inflammatory cytokines Il1b and Il6 and markers associated with myocardial fibrosis, including Lgal3 and Timp1.

CONCLUSION

These findings suggest that doxorubicin-induced cardiac events are suppressed by the administration of mosapride and sirolimus.

Bone morphogenetic protein 10 alleviates doxorubicin-induced cardiac injury via signal transducer and activator of transcription 3 signaling pathway

Doxorubicin (DOX) has limited antitumor applications owing to its association with life-threatening cardiac injury. Oxidative damage and cardiac apoptosis are crucial in DOX-induced cardiac injury. Bone morphogenetic protein 10 (BMP10) is predominantly distributed in the heart and acts as a cardioprotective factor that preserves cardiac function. However, the role of BMP10 in DOX-induced cardiac injury has not yet been explored. The current study aimed to examine the function and mechanism of action of BMP10 in DOX-induced cardiac injury. An adeno-associated viral system was used for the overexpression or silencing of cardiac-specific BMP10, and subsequently, a single dose of DOX was intraperitoneally injected to induce cardiac injury. Results showed that DOX exposure decreased BMP10 expression in the heart. Cardiac-specific overexpression of BMP10 alleviated the oxidative stress and apoptosis and improved cardiac function. Conversely, cardiac-specific silencing of BMP10 aggravated the redox disorder and apoptosis and worsened the cardiac dysfunction caused by DOX. Exogenous BMP10 supplementation amelioratesd the DOX-induced cardiac contractile dysfunction. Mechanistically, we found that phosphorylation of signal transducer and activator of transcription 3 (STAT3) is reduced in DOX-induced cardiotoxicity, and, BMP10 activated impaired STAT3 via a non-canonical pathway. BMP10 lost its cardioprotective function in cardiomyocyte-specific STAT3 knockout (STAT3-cKO) mice. Based on our findings, we suggested that BMP10 is a potential therapeutic agent against DOX-induced cardiac injury and that the cardioprotective effects of BMP10 are dependent on the activation of STAT3.

Fisetin Attenuates Doxorubicin-Induced Cardiomyopathy In Vivo and In Vitro by Inhibiting Ferroptosis Through SIRT1/Nrf2 Signaling Pathway Activation

Doxorubicin (DOX) is an anthracycline antibiotic that is used extensively for the management of carcinoma; however, its clinical application is limited due to its serious cardiotoxic side effects. Ferroptosis represents iron-dependent and reactive oxygen species (ROS)-related cell death and has been proven to contribute to the progression of DOX-induced cardiomyopathy. Fisetin is a natural flavonoid that is abundantly present in fruits and vegetables. It has been reported to exert cardioprotective effects against DOX-induced cardiotoxicity in experimental rats. However, the underlying mechanisms remain unknown. The present study investigated the cardioprotective role of fisetin and the underlying molecular mechanism through experiments in the DOX-induced cardiomyopathy rat and H9c2 cell models. The results revealed that fisetin treatment could markedly abate DOX-induced cardiotoxicity by alleviating cardiac dysfunction, ameliorating myocardial fibrosis, mitigating cardiac hypertrophy in rats, and attenuating ferroptosis of cardiomyocytes by reversing the decline in the GPX4 level. Mechanistically, fisetin exerted its antioxidant effect by reducing the MDA and lipid ROS levels and increasing the glutathione (GSH) level. Moreover, fisetin exerted its protective effect by increasing the SIRT1 expression and the Nrf2 mRNA and protein levels and its nuclear translocation, which resulted in the activation of its downstream genes such as HO-1 and FTH1. Selective inhibition of SIRT1 attenuated the protective effects of fisetin in the H9c2 cells, which in turn decreased the GSH and GPX4 levels, as well as Nrf2, HO-1, and FTH1 expressions. In conclusion, fisetin exerts its therapeutic effects against DOX-induced cardiomyopathy by inhibiting ferroptosis via SIRT1/Nrf2 signaling pathway activation.

Reduced CTRP3 Levels in Patients with Stable Coronary Artery Disease and Related with the Presence of Paroxysmal Atrial Fibrillation

BACKGROUND

Serum Complement C1q/tumor necrosis factor-related protein-3 (CTRP3) levels and the relationship with atrial fibrillation (AF) in stable coronary artery disease (CAD) are not clearly known.

OBJECTIVE

The aim of this study was to investigate the change in serum CTRP3 levels and its relationship with paroxysmal AF in stable CAD.

METHOD

The study included 252 patients with CAD and 50 age-sex matched healthy control subjects. Serum CTRP3 levels were measured in addition to routine anamnesis, physical examination, laboratory and echocardiography examinations. The patients were divided into groups with and without CAD and CAD patients with and without paroxysmal AF. Statistical significance was accepted as p<0.05.

RESULTS

Serum CTRP3 levels were found to be significantly lower in patients with CAD than in the control group (p<0.001). AF was detected in 38 patients (15.08%) in the CAD group. The frequency of hypertension and female gender, hs-CRP, blood urea nitrogen, creatinine levels and left atrial end-diastolic (LAd) diameter were higher (p<0.05 for each one), and CTRP3 levels were lower in patients with AF (p <0.001). In the logistic regression analysis, serum CTRP3 levels and LAd diameters were independently determined the patients with AF (p<0.01 for each one). In this analysis, we found that every 1 ng/mL reduction in CTRP3 levels increased the risk of AF by 10.7%. In the ROC analysis of CTRP3 values for detecting patients with AF, the area under the ROC curve for CTRP3 was 0.971 (0.951-991) and was statistically significant (p<0.001). When the CTRP3 cut-off value was taken as 300 ng/mL, it was found to predict the presence of AF with 87.9% sensitivity and 86.8% specificity.

CONCLUSION

Serum CTRP3 levels were significantly reduced in patients with stable CAD and decreased CTRP3 levels were closely related to the presence of paroxysmal AF in these patients.

RRM2 Alleviates Doxorubicin-Induced Cardiotoxicity through the AKT/mTOR Signaling Pathway

Doxorubicin (DOX) is an effective chemotherapeutic agent that plays an unparalleled role in cancer treatment. However, its serious dose-dependent cardiotoxicity, which eventually contributes to irreversible heart failure, has greatly limited the widespread clinical application of DOX. A previous study has demonstrated that the ribonucleotide reductase M2 subunit (RRM2) exerts salutary effects on promoting proliferation and inhibiting apoptosis and autophagy. However, the specific function of RRM2 in DOX-induced cardiotoxicity is yet to be determined. This study aimed to elucidate the role and potential mechanism of RRM2 on DOX-induced cardiotoxicity by investigating neonatal primary cardiomyocytes and mice treated with DOX. Subsequently, the results indicated that RRM2 expression was significantly reduced in mice hearts and primary cardiomyocytes. Apoptosis and autophagy-related proteins, such as cleaved-Caspase3 (C-Caspase3), LC3B, and beclin1, were distinctly upregulated. Additionally, RRM2 deficiency led to increased autophagy and apoptosis in cells. RRM2 overexpression, on the contrary, alleviated DOX-induced cardiotoxicity in vivo and in vitro. Consistently, DIDOX, an inhibitor of RRM2, attenuated the protective effect of RRM2. Mechanistically, we found that AKT/mTOR inhibitors could reverse the function of RRM2 overexpression on DOX-induced autophagy and apoptosis, which means that RRM2 could have regulated DOX-induced cardiotoxicity through the AKT/mTOR signaling pathway. In conclusion, our experiment established that RRM2 could be a potential treatment in reversing DOX-induced cardiac dysfunction.

Vitamin E and levocarnitine as prophylaxis against doxorubicin-induced cardio toxicity in the adult cancer patient: A review

OBJECTIVE

Doxorubicin, a component of the anthracycline group, is a highly effective in the treatment of hematologic and solid malignancies. Because of the cardiotoxic adverse effects, use is limited. Antioxidants may negate this anthracycline-induced cardiotoxicity, although the literature is not conclusive with regards to the cardioprotective benefits of antioxidants. This review assessed and mapped evidence of the efficacy of vitamin E and levocarnitine against doxorubicin-induced cardiotoxicity in adult cancer patients.

DATA SOURCES

This review was based on the Arksey and O'Malley methodology. Potentially relevant literature in English published between January 1960 and April 2021 was identified through a database search. Oxford Quality Scoring System and AMSTR2 were used to assess the quality of trials and systematic reviews respectively, as well as the risks of potential bias.

DATA SUMMARY

Nineteen of the 10 268 (0.2%) articles from the initial search were included in the final analysis (12 clinical trials and 7 systematic reviews). Vitamin E was included in seven prospective clinical trials. Levocarnitine was included in five clinical trials as an individual agent and a single trial as a combination treatment. No trials could be found investigating the combination of vitamin E and levocarnitine in humans.

CONCLUSIONS

This review found that levocarnitine trials showed some cardioprotective effects but the results from vitamin E trials were controversial and inconclusive. Most of the trials reviewed had some shortcomings. Further investigations are therefore needed to determine the efficacy of vitamin E and levocarnitine in preventing doxorubicin-induced cardiotoxicity in adult cancer patients.

Palmatine attenuates the doxorubicin-induced inflammatory response, oxidative damage and cardiomyocyte apoptosis

BACKGROUND

As a natural isoquinoline alkaloid, palmatine (PLT) has been proven to play a protective role against a variety of cardiovascular diseases. However, little research on the effects of PLT on doxorubicin (DOX)-induced cardiotoxicity has been carried out. Thus, we investigated the potential functions of PLT in DOX-induced cardiotoxicity. In the present study, a single intraperitoneal injection of DOX (15 mg/kg) in mice was used to establish an acute cardiotoxicity model. Our study shows that PLT administration could reduce myocardial injury and improve cardiac dysfunction in DOX-treated mice. Further experiments showed that PLT administration suppressed the DOX-induced inflammatory response, oxidative damage and cardiomyocyte apoptosis in mice. Moreover, we found that the protective effect of PLT treatment was counteracted by sirtuin1 (Sirt1) knockdown. In summary, our study shows that PLT treatment can exert a protective effect against DOX-induced cardiotoxicity.

SIRT4 Suppresses Doxorubicin-Induced Cardiotoxicity by Regulating the AKT/mTOR/Autophagy Pathway

Doxorubicin (DOX) is a potent anthracycline chemotherapeutic drug. DOX-induced cardiotoxicity (DIC) limits its application in cancer treatment, as this complication is detrimental and fatal. Reactive oxygen species (ROS) production, autophagic dysfunction and cell death are crucial factors related to DIC. Previous studies have shown that SIRT4 is associated with cardiac energy metabolism, cardiac mitochondrial dysfunction and cardiac cell death, but it is unclear whether SIRT4 affects DOX-induced cardiac injury. Our data suggested that SIRT4 overexpression in vivo and in vitro could alleviate DIC by improving cardiac function and reducing cardiomyocyte apoptosis and autophagy. However, autophagy activation by rapamycin abolished the protective effect of SIRT4 overexpression on DIC. Furthermore, in the context of DOX treatment, SIRT4 overexpression activated the Akt/mTOR signaling pathway and inhibited autophagy through the Akt/mTOR signaling pathway. Our findings indicate that SIRT4 overexpression protects against DIC by inhibiting Akt/mTOR-dependent autophagy. These findings may provide a prospective therapeutic target for DIC.

MiR-24-3p Attenuates Doxorubicin-induced Cardiotoxicity via the Nrf2 Pathway in Mice

OBJECTIVE

The nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf2) is associated with doxorubicin (DOX)-induced cardiac injury. It has been reported that microRNA-24-3p (miR-24-3p) may regulate the Keapl by mRNA degradation, whereas Keapl can suppress the activation of Nrf2. However, the role of miR-24-3p in DOX-related cardiotoxicity remains unclear.

METHODS

The mice receiving DOX were used as cardiac injury model. In this study, an adenoassociated virus 9 system was used to deliver miR-24-3p or miR-scramble to mice hearts. The echocardiographic and hemodynamic analyses were used to evaluate the effects of miR-24-3p on cardiac function under DOX stimulation. ELISA and RT-PCR were used to detect protein or mRNA expressions associated with cardiac injury, inflammation response, apoptosis and oxidative stress. Western Blot were used for quantitative analysis of the roles of miR-24-3p in regulating Nrf2 expression. H9C2 cells used to verify the role of miR-24-3p in vitro.

RESULTS

We found that miR-24-3p mRNA was significantly decreased in DOX-treated mice and cardiomyocytes. Overexpression of miR-24-3p blocked cardiac injury caused by DOX injection, as reflected by the reduction in the levels of cardiac troponin I, creatinine kinase isoenzyme MB and the N-terminal pro brain natriuretic peptide. Furthermore, miR-24-3p reduced oxidative stress and cell loss without affecting the inflammation response. As expected, we found that Nrf2 was upregulated by miR-24-3p supplementation, and that the protective efforts of miR-24-3p supplementation were abolished when Nrf2 was silenced.

CONCLUSION

The results from this study suggest that miR-24-3p protects cardiomyocytes against DOX-induced heart injury via activation of the Nrf2 pathway. miR-24-3p supplementation may be a novel strategy to counteract the cardiac side effects of DOX treatment.

Therapeutic Targets for DOX-Induced Cardiomyopathy: Role of Apoptosis vs. Ferroptosis

Doxorubicin (DOX) is the most widely used anthracycline anticancer agent; however, its cardiotoxicity limits its clinical efficacy. Numerous studies have elucidated the mechanisms underlying DOX-induced cardiotoxicity, wherein apoptosis has been reported as the most common final step leading to cardiomyocyte death. However, in the past two years, the involvement of ferroptosis, a novel programmed cell death, has been proposed. The purpose of this review is to summarize the historical background that led to each form of cell death, focusing on DOX-induced cardiotoxicity and the molecular mechanisms that trigger each form of cell death. Furthermore, based on this understanding, possible therapeutic strategies to prevent DOX cardiotoxicity are outlined. DNA damage, oxidative stress, intracellular signaling, transcription factors, epigenetic regulators, autophagy, and metabolic inflammation are important factors in the molecular mechanisms of DOX-induced cardiomyocyte apoptosis. Conversely, the accumulation of lipid peroxides, iron ion accumulation, and decreased expression of glutathione and glutathione peroxidase 4 are important in ferroptosis. In both cascades, the mitochondria are an important site of DOX cardiotoxicity. The last part of this review focuses on the significance of the disruption of mitochondrial homeostasis in DOX cardiotoxicity.

Long non-coding RNA MALAT1 silencing elevates microRNA-26a-5p to ameliorate myocardial injury in sepsis by reducing regulator of calcineurin 2

OBJECTIVE

Sepsis is a leading cause of morbidity and mortality after surgery. We aimed to explore the role of long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) sponging microRNA-26a-5p in sepsis-induced myocardial injury by regulating regulator of calcineurin 2 (Rcan2).

METHODS

HL-1 cells were incubated with lipopolysaccharide (LPS) to induce in vitro cardiomyocyte injury models, which were then treated with silenced MALAT1 vector, miR-26a-5p mimic or Rcan2 overexpression vector. Next, inflammatory factor level and apoptosis of cells were determined. The in vivo mouse models were constructed by intraperitoneal injection of LPS. The modeled mice were injected with relative oligonucleotides and the pathology, apoptosis, and inflammation in mouse myocardial tissues were assessed. Expression of MALAT1, miR-26a-5p and Rcan2 in vivo and in vitro was evaluated.

RESULTS

MALAT1 and Rcan2 were upregulated while miR-26a-5p was downregulated in LPS-treated HL-1 cells and mice. MALAT1 silencing or miR-26a-5p upregulation suppressed LPS-induced inflammation and apoptosis of cardiomyocytes in cellular and animal models. These effects of elevated miR-26a-5p could be reversed by upregulating Rcan2, and MALAT1 knockdown-induced ameliorative impacts could be reversed by miR-26a-5p downregulation.

CONCLUSION

MALAT1 silencing elevated miR-26a-5p to ameliorate LPS-induced myocardial injury by reducing Rcan2. Our research may provide novel biomarkers for the treatment of sepsis.