The role of autophagy in death of cardiomyocytes

CircRNA CDR1AS promotes cardiac ischemia-reperfusion injury in mice by triggering cardiomyocyte autosis

Myocardial ischemia/reperfusion (IR) injury is a common adverse event in the clinical treatment of myocardial ischemic disease. Autosis is a form of cell death that occurs when autophagy is excessive in cells, and it has been associated with cardiac IR damage. This study aimed to investigate the regulatory mechanism of circRNA CDR1AS on autosis in cardiomyocytes under IR. The expression of CDR1AS increases after myocardial IR, and overexpression of CDR1AS detrimentally affects cardiac function, increases infarct area, promotes excessive autophagy, and blocks the flow of autophagy to induce autosis after IR. Conversely, knockdown of CDR1AS reversed the autophagy-related markers caused by IR, increasing cardiomyocyte activity, improving cardiac dysfunction and infarct area, and restoring the flow of autophagy. Further analysis of RNA sequencing and validation experiments revealed that CDR1AS aggravated autophagic damage, increased autophagosome accumulation, and promoted autosis by inhibiting the levels of LAMP2 and mTORC1 proteins. Additionally, RIP and pull-down assays showed that CDR1AS interacts with LAMP2 or mTORC1. First-time evidence reveals that circRNA CDR1AS regulates lysosomal membrane proteins by regulating the mTORC1/ULK1 pathway during myocardial IR-induced autosis. This suggests that maintaining moderate autophagy is a crucial part of the fight against myocardial IR damage. KEY MESSAGES: CDR1AS expression was significantly increased in myocardium following IR. CDR1AS can increase the occurrence of autosis after IR. CDR1AS reduces the phosphorylation of ULK1, promoting the formation of autophagosomes. CDR1AS binds to LAMP2 and blocks the autophagosome clearance pathway. The specific mechanism of CDR1AS regulating IR is achieved by regulating autosis.

Autophagy in myocardial ischemia and ischemia/reperfusion

Myocardial infarction (MI) is a life-threatening condition that leads to loss of viable heart tissue. The best way to treat acute MI and limit the infarct size is to re-open the occluded coronary artery and restore the supply of oxygenated and nutrient-rich blood, but reperfusion can cause additional damage. Autophagy is an intracellular process that recycles damaged cytoplasmic components (molecules and organelles) by loading them into autophagosomes and degrading them in autolysosomes. Autophagy is increased in in vivo animal models of permanent ischemia and ischemia/reperfusion but by different molecular mechanisms. While autophagy is protective during permanent ischemia, it is detrimental during ischemia/reperfusion. Its modulation is being investigated as a potential target to reduce reperfusion injury. This review provides a synopsis of the current knowledge about autophagy, summarizes findings specifically in permanent ischemia and ischemia/reperfusion, and briefly discusses the potential implication of experimental findings.

ErbB2-NOTCH1 axis controls autophagy in cardiac cells

Although the epidermal growth factor receptor 2 (ErbB2) and Notch1 signaling pathways have both significant roles in regulating cardiac biology, their interplay in the heart remains poorly investigated. Here, we present evidence of a crosstalk between ErbB2 and Notch1 in cardiac cells, with effects on autophagy and proliferation. Overexpression of ErbB2 in H9c2 cardiomyoblasts induced Notch1 activation in a post-transcriptional, p38-dependent manner, while ErbB2 inhibition with the specific inhibitor, lapatinib, reduced Notch1 activation. Moreover, incubation of H9c2 cells with lapatinib resulted in stalled autophagic flux and decreased proliferation, consistent with the established cardiotoxicity of this and other ErbB2-targeting drugs. Confirming the findings in H9c2 cells, exposure of primary neonatal mouse cardiomyocytes to exogenous neuregulin-1, which engages ErbB2, stimulated proliferation, and this effect was abrogated by concomitant inhibition of the enzyme responsible for Notch1 activation. Furthermore, the hearts of transgenic mice specifically overexpressing ErbB2 in cardiomyocytes had increased levels of active Notch1 and of Notch-related genes. These data expand the knowledge of ErbB2 and Notch1 functions in the heart and may allow better understanding the mechanisms of the cardiotoxicity of ErbB2-targeting cancer treatments.

eEF2K alleviates doxorubicin-induced cardiotoxicity by inhibiting GSK3β and improving autophagy dysfunction

Doxorubicin-induced cardiotoxicity (DIC) poses a threat to the health and prognosis of cancer patients. It is important to find a safe and effective method for the prevention and treatment of DIC. eEF2K, which is a highly conserved α-kinase, is thought to be a therapeutic target for several human diseases. Nonetheless, it is still uncertain if eEF2K contributes to the cardiotoxic effects caused by doxorubicin (DOX). Our research revealed that eEF2K expression decreased in the DIC. eEF2K was overexpressed through adeno-associated virus in vivo and adenovirus in vitro, which presented alleviative cardiomyocyte death and cell atrophy induced by DOX. Autophagy dysfunction is one of important mechanisms in DIC. As a result, autophagic function was evaluated using Transmission electron microscopy in vivo, as well as LysoSensor and mRFPGFP-LC3 puncta in vitro. eEF2K overexpression improves DOX-induced autophagy blockade. In addition, eEF2K knockdown aggravated autophagy blockade and cardiomyocyte injury in DIC model. eEF2K also phosphorylated and inhibited GSK3β in DIC model. AR-A014418 (ARi), known for selectively inhibiting GSK3β, countered the effects of eEF2K knockdown, which aggravated autophagy blockade in the DIC. In conclusion, this study proposes that eEF2K alleviates DIC by inhibiting GSK3β and improving autophagy dysfunction. eEF2K is a promising therapeutic target against DIC.

Identification and validation of autophagy‑related genes in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant cardiac disorder characterized by ventricular hypertrophy resulting from the disordered arrangement of myocardial cells, which leads to impaired cardiac function or death. Autophagy (AT) is a biochemical process through which lysosomes degrade and recycle damaged or discarded intracellular components to protect cells against external environmental conditions, such as hypoxia and oxidative stress. AT is closely related to HCM, and thus, serves an important role in myocardial hypertrophy. However, the precise mechanism underlying the regulation of AT in cardiac hypertrophy remains elusive. The present study aimed to examine the role and mechanisms of AT-related genes (ARGs) in HCM through bioinformatics analysis and experimental validation and to identify potential targeted drugs for HCM. In this study, cardiac samples were obtained from healthy individuals and patients with HCM from the GEO database, and screened for differentially expressed ARGs to further investigate their potential interactions and functional pathways. These genes were subjected to functional enrichment analysis to identify potential crosstalk and involved pathways. Based on a protein-protein interaction network, EIF4EBP1, MCL1, PIK3R1, CCND1 and PPARG were identified as potential biomarkers for the diagnosis and treatment of HCM. Furthermore, 10 components with therapeutic potential for HCM were predicted based on the aforementioned hub genes. The results of bioinformatics analysis were validated using H9c2 cells stimulated with angiotensin II, which represented an in vitro model of cardiac hypertrophy. Overall, the present study demonstrated that the expression levels of ARGs were substantially altered in HCM. Therefore, these genes may be used as diagnostic biomarkers and therapeutic targets for HCM.

Curcumin pretreatment attenuates myocardial ischemia/reperfusion injury by inhibiting ferroptosis, autophagy and apoptosis via HES1

The early restoration of hemodynamics/reperfusion in acute myocardial infarction (AMI) is an effective therapeutic strategy to reduce sudden death and improve patient prognosis. However, reperfusion induces additional cardiomyocyte damage and cardiac tissue dysfunction. In this context, turmeric‑derived curcumin (Cur) has been shown to exhibit a protective effect against myocardial ischemia/reperfusion injury (I/RI). The molecular mechanism of its activity, however, remains unclear. The current study investigated the protective effect of Cur and its molecular mechanism via in vitro experiments. The Cell Counting Kit‑8 and lactate dehydrogenase (LDH) assay kit were used to assess the cell viability and cytotoxicity. The contents of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase, glutathione (GSH)/glutathione disulfide (GSSG), total iron, ferrous iron, caspase‑3 and reactive oxygen species (ROS) were measured using an appropriate kit. Western blotting was used to detect the expression of relevant proteins. The levels of apoptosis, mitochondrial permeability transition pore (MPTP) opening, and mitochondrial membrane potential (MMP) were detected by flow cytometry. The study findings indicated that anoxia/reoxygenation (A/R) injury significantly decreased cell viability, increased in LDH and caspase‑3 activities, induced ferroptosis, increased apoptosis and overactivated autophagy. However, pretreatment with Cur or ferrostatin‑1 (Fer‑1, a ferroptosis inhibitor) significantly increased A/R‑reduced cell viability, SOD, glutathione peroxidase activity, GSH/GSSH ratio and HES1 and glutathione peroxidase 4 protein expression; attenuated A/R‑induced LDH, MDA, total iron, ferrous iron, prostaglandin‑endoperoxide synthase 2 protein expression and prevented ROS overproduction and MMP loss. In addition, Cur inhibited caspase‑3 activity, upregulated the Bcl‑2/Bax ratio, reduced apoptotic cell number and inhibited MPTP over‑opening. Furthermore, Cur increased P62, LC3II/I, NDUFB8 and UQCRC2 expression and upregulated the p‑AMPK/AMPK ratio. However, erastin (a ferroptosis activator), pAD/HES1‑short hairpin RNA, rapamycin (an autophagy activator) and Compound C (an AMPK inhibitor) blocked the protective effect of Cur. In conclusion, Cur pretreatment inhibited ferroptosis, autophagy overactivation and oxidative stress; improved mitochondrial dysfunction; maintained energy homeostasis; attenuated apoptosis; and ultimately protected the myocardium from A/R injury via increased HES1 expression.

Inhibition of the FOXO1-ROCK1 axis mitigates cardiomyocyte injury under chronic hypoxia in Tetralogy of Fallot by maintaining mitochondrial quality control

INTRODUCTION

Persistent chronic myocardial hypoxia causes disturbances in mitochondrial quality control (MQC), ultimately leading to increased cardiomyocyte injury in patients with Tetralogy of Fallot (TOF). The present study aimed to identify the key effector molecules of cardiomyocyte injury under chronic hypoxia in TOF.

METHODS

Clinical data from TOF patients were collected and whole transcriptome sequencing was performed on myocardial samples. Chronic hypoxia models were established in cardiac-specific knockout mice and cardiomyocytes, and a series of molecular experiments were used to determine the specific mechanisms involved.

RESULTS

Clinical cohort data and whole-transcriptome sequencing analysis of myocardial samples from TOF patients revealed that forkhead box O1 (FOXO1) plays an important role in chronic hypoxic cardiomyocyte injury. In a model of chronic hypoxia established in FOXO1 cardiac-specific knockout mice and FOXO1 gene-deficient cardiomyocytes, the AMPK signaling pathway regulates the expression of FOXO1, which in turn disrupts MQC by regulating the transcriptional activation of Rho-associated protein kinase 1 (ROCK1), and increasing the production of mitochondrial ROS, thereby exacerbating damage to cardiomyocytes. Excessive reactive oxygen species (ROS) production during MQC dysfunction further activates Cox7a2L to increase the assembly of the respiratory chain supercomplex. In addition, we found that miR-27b-3p partially binds to the 3' untranslated region of FOXO1 to exert a protective effect.

CONCLUSIONS

Maintenance of MQC under chronic hypoxia is achieved through a series of injury-protection mechanisms, suggesting that FOXO1 inhibition may be crucial for future mitigation of chronic hypoxic cardiomyocyte injury in TOF.

Dexmedetomidine regulates exosomal miR-29b-3p from macrophages and alleviates septic myocardial injury by promoting autophagy in cardiomyocytes via targeting glycogen synthase kinase 3β

Background

Our previous research suggested that dexmedetomidine (Dex) promotes autophagy in cardiomyocytes, thus safeguarding them against apoptosis during sepsis. However, the underlying mechanisms of Dex-regulated autophagy have remained elusive. This study aimed to explore the role of exosomes and how they participate in Dex-induced cardioprotection in sepsis. The underlying microRNA (miRNA) mechanisms and possible therapeutic targets for septic myocardial injury were identified.

Methods

We first collected plasma exosomes from rats with sepsis induced by caecal ligation and puncture (CLP) with or without Dex treatment, and then incubated them with H9c2 cells to observe the effect on cardiomyocytes. Subsequently, the differential expression of miRNAs in plasma exosomes from each group of rats was identified through miRNA sequencing. miR-29b-3p expression in circulating exosomes of septic or non-septic patients, as well as in lipopolysaccharide-induced macrophages after Dex treatment, was analysed by quantitative real-time polymerase chain reaction (qRT-PCR). The autophagy level of cardiomyocytes after macrophage-derived exosome treatment was assessed by an exosome tracing assay, western blotting, and an autophagic flux assay. Specific miRNA mimics and inhibitors or small interfering RNAs were used to predict and evaluate the function of candidate miRNA and its target genes by qRT-PCR, annexin V/propyl iodide staining, autophagy flux analysis, and western blotting.

Results

We found that plasma-derived exosomes from Dex-treated rats promoted cardiomyocyte autophagy and exerted antiapoptotic effects. Additionally, they exhibited a high expression of miRNA, including miR-29b-3p. Conversely, a significant decrease in miR-29b-3p was observed in circulating exosomes from CLP rats, as well as in plasma exosomes from sepsis patients. Furthermore, Dex upregulated the lipopolysaccharide-induced decrease in miR-29b-3p expression in macrophage-derived exosomes. Exosomal miR-29b-3p from macrophages is thought to be transferred to cardiomyocytes, thus leading to the promotion of autophagy in cardiomyocytes. Database predictions, luciferase reporter assays, and small interfering RNA intervention confirmed that glycogen synthase kinase 3β (GSK-3β) is a target of miR-29b-3p. miR-29b-3p promotes cardiomyocyte autophagy by inhibiting GSK-3β expression and activation.

Conclusions

These findings demonstrate that Dex attenuates sepsis-associated myocardial injury by modulating exosome-mediated macrophage-cardiomyocyte crosstalk and that the miR-29b-3p/GSK-3β signaling pathway represents a hopeful target for the treatment of septic myocardial injury.

The Role of Retinoic-Acid-Related Orphan Receptor (RORs) in Cellular Homeostasis

Retinoic-acid-related orphan receptors (RORs) are transcription factors belonging to the nuclear receptor subfamily consisting of RORα, RORβ, and RORγ. By binding to the ROR response elements (ROREs) on target gene promoters, RORs regulate a wide variety of cellular processes, including autophagy, mitophagy, oxidative stress, and inflammation. The regulatory roles of RORs are observed in cardiac cells, hepatocytes, pulmonary epithelial cells, renal cells, immune cells, and cancer cells. A growing body of clinical and experimental evidence suggests that ROR expression levels are markedly reduced under different pathological and stress conditions, suggesting that RORs may play a critical role in the pathogenesis of a variety of disease states, including myocardial infarction, immune disorders, cancer, and metabolic syndrome. Reductions in RORs are also associated with inhibition of autophagy, increased reactive oxygen species (ROS), and increased cell death, underscoring the importance of RORs in the regulation of these processes. Herein, we highlight the relationship between RORs and homeostatic processes that influence cell viability. Understanding how these intricate processes are governed at the cellular level is of high scientific and clinical importance to develop new therapeutic strategies that modulate ROR expression and disease progression.

Effect of phosphatase and tensin homolog-induced putative kinase 1/ E3 ubiquitin ligase Parkin mediated mitochondrial autophagy on chronic kidney disease myocardial injury and the intervention mechanism of Shenshuai recipe

OBJECTIVE

To study whether Shenshuai recipe (, SSR) can play a protective role on chronic kidney disease myocardial injury model through phosphatase and tensin homolog-induced putative kinase 1 (PINK1)/E3 ubiquitin ligase Parkin (Parkin) mitochondrial autophagy pathway.

METHODS

Forty-eight nephrectomized rats were randomly divided into six groups: sham-operated group, model group, Benazepril group, low, medium and high-dose groups of SSR. The rats were given the cor-responding intervention for six weeks, then were sacrificed. Serum was examined by enzyme linked immunosorbent assay (ELISA). Cardiac ultrasound was used to detect cardiac function in 5/6 nephrectomized rats. Myocardial tissue was examined by light and electron microscopy; PINK1, Parkin, microtubule-associated protein1 light chain 3 II (LC3B), sequestosome 1 (P62), BECN1 (Beclin-1) and dynamin-related protein 1 (Drp-1) were measured by real time polymerase chain reaction (RT-PCR), Western blot (WB) and immunohistochemistry (IHC).

RESULTS

The expression levels of blood urea nitrogen (BUN) and creatinine (SCr) in the model group were significantly higher than those in the sham-operated group, indicating that modeling was successful. SSR can protect myocardium by reducing the relative expression of creatine kinase myocardial isoenzyme and hypersensitivity cardiac troponin I (P<0.05). SSR can improve cardiac function in rats after ultrasound testing. SSR can improve the pathological manifestations of myocardial tissue after Masson staining. SSR can increase the number of autophagosomes and autophagiclysosomes in 5/6 nephrectomized rats (P<0.05). Determined by RT-PCR, WB and IHC, SSR can increase the relative expression of PINK1, Parkin, and LC3B (P<0.05), and decrease the relative expression of P62, Beclin-1 and Drp-1 (P<0.05).

CONCLUSIONS

The PINK1/Parkin mitochondrial autophagy pathway in myocardial tissues in 5/6 nephrectomy CKD myocardial injury rats was inhibited. SSR can activate PINK1/Parkin mitochondrial autophagy to enhance mitochondrial autophagy, and play a protective role in myocardial tissues.

20S-O-Glc-DM treats left ventricular diastolic dysfunction by modulating cardiomyocyte mitochondrial quality and excess autophagy

BACKGROUND

Left ventricular diastolic dysfunction (LVDD) is a manifestation of heart failure, with both its incidence and prevalence increasing annually. Currently, no pharmacological treatments are available for LVDD, highlighting the urgent need for new therapeutic discoveries. Ginsenosides are commonly used in cardiovascular therapy. Previous research has synthesized the ginsenoside precursor molecule, 20S-O-Glc-DM (C20DM), through biosynthesis. C20DM shows greater bioavailability, eco-friendliness, and cost-effectiveness compared to traditional ginsenosides, positioning it as a promising option for treating LVDD.

PURPOSE

This study firstly documents the therapeutic activity of C20DM against LVDD and unveils its potential mechanisms of action. It provides a pharmacological basis for C20DM as a new cardiovascular therapeutic agent.

METHODS

In this study, models of LVDD in mice and ISO-induced H9C2 cell damage were developed. Cell viability, ROS and Ca2+ levels, mitochondrial membrane potential, and proteins associated with mitochondrial biogenesis and autophagy were evaluated in the in vitro experiments. Animal experiments involved administering medication for 3 weeks to validate the therapeutic effects of C20DM and its impact on mitochondria and autophagy.

RESULTS

Research has shown that C20DM is more effective than Metoprolol in treating LVDD, significantly lowering the E/A ratio, e'/a' ratio, and IVRT, and ameliorating myocardial inflammation and fibrosis. C20DM influences the activity of PGC-1α, downregulates PINK1 and Parkin, thereby enhancing mitochondrial quality control, and restoring mitochondrial oxidative respiration and membrane potential. Furthermore, C20DM reduces excessive autophagy in cardiomyocytes via the AMPK-mTOR-ULK1 pathway, diminishing cardiomyocyte hypertrophy and damage.

CONCLUSIONS

Overall, our research indicates that C20DM has the potential to enhance LVDD through the regulation of mitochondrial quality control and cellular autophagy, making it a promising option for heart failure therapy.

The roles and mechanisms of endoplasmic reticulum stress-mediated autophagy in animal viral infections

The endoplasmic reticulum (ER) is a unique organelle responsible for protein synthesis and processing, lipid synthesis in eukaryotic cells, and the replication of many animal viruses is closely related to ER. A considerable number of viral proteins are synthesised during viral infection, resulting in the accumulation of unfolded and misfolded proteins in ER, which in turn induces endoplasmic reticulum stress (ERS). ERS further drives three signalling pathways (PERK, IRE1, and ATF6) of the cellular unfolded protein response (UPR) to respond to the ERS. In numerous studies, ERS has been shown to mediate autophagy, a highly conserved cellular degradation mechanism to maintain cellular homeostasis in eukaryotic cells, through the UPR to restore ER homeostasis. ERS-mediated autophagy is closely linked to the occurrence and development of numerous viral diseases in animals. Host cells can inhibit viral replication by regulating ERS-mediated autophagy, restoring the ER's normal physiological process. Conversely, many viruses have evolved strategies to exploit ERS-mediated autophagy to achieve immune escape. These strategies include the regulation of PERK-eIF2α-Beclin1, PERK-eIF2α-ATF4-ATG12, IRE1α-JNK-Beclin1, and other signalling pathways, which provide favourable conditions for the replication of animal viruses in host cells. The ERS-mediated autophagy pathway has become a hot topic in animal virological research. This article reviews the most recent research regarding the regulatory functions of ERS-mediated autophagy pathways in animal viral infections, emphasising the underlying mechanisms in the context of different viral infections. Furthermore, it considers the future direction and challenges in the development of ERS-mediated autophagy targeting strategies for combating animal viral diseases, which will contribute to unveiling their pathogenic mechanism from a new perspective and provide a scientific reference for the discovery and development of new antiviral drugs and preventive strategies.

ALCAT1-Mediated Pathological Cardiolipin Remodeling and PLSCR3-Mediated Cardiolipin Transferring Contribute to LPS-Induced Myocardial Injury

Cardiolipin (CL), a critical phospholipid situated within the mitochondrial membrane, plays a significant role in modulating intramitochondrial processes, especially in the context of certain cardiac pathologies; however, the exact effects of alterations in cardiolipin on septic cardiomyopathy (SCM) are still debated and the underlying mechanisms remain incompletely understood. This study highlights a notable increase in the expressions of ALCAT1 and PLSCR3 during the advanced stage of lipopolysaccharide (LPS)-induced SCM. This up-regulation potential contribution to mitochondrial dysfunction and cellular apoptosis-as indicated by the augmented oxidative stress and cytochrome c (Cytc) release-coupled with reduced mitophagy, decreased levels of the antiapoptotic protein B-cell lymphoma-2 (Bcl-2) and lowered cell viability. Additionally, the timing of LPS-induced apoptosis coincides with the decline in both autophagy and mitophagy at the late stages, implying that these processes may serve as protective factors against LPS-induced SCM in HL-1 cells. Together, these findings reveal the mechanism of LPS-induced CL changes in the center of SCM, with a particular emphasis on the importance of pathological remodeling and translocation of CL to mitochondrial function and apoptosis. Additionally, it highlights the protective effect of mitophagy in the early stage of SCM. This study complements previous research on the mechanism of CL changes in mediating SCM. These findings enhance our understanding of the role of CL in cardiac pathology and provide a new direction for future research.

Panax notoginseng saponins dually modulates autophagy in gastric precancerous lesions complicated with myocardial ischemia-reperfusion injury model through the PI3K/AKT/mTOR pathway

Gastric precancerous lesion (GPL) is a crucial stage in the development of gastric cancer, characterized by incomplete intestinal epithelial chemotaxis and heterogeneous hyperplasia with high malignant potential. Early intervention in GPL is vital for preventing gastric cancer. Additionally, there are shared risk factors and pathogenesis between tumors and coronary heart disease (CHD), with an increasing number of tumor patients GPL complicated with CHD due to improved survival rates. Reperfusion therapy in CHD can result in myocardial ischemia-reperfusion injury (MIRI). Traditional Chinese medicine (TCM) has demonstrated unique advantages in treating GPL and MIRI by promoting blood circulation and removing blood stasis. Panax ginseng total saponin (PNS), a component of TCM known for its blood circulation benefits, has shown positive effects in inhibiting tumor growth and improving myocardial ischemia. This study utilized a GPL-MIRI mouse model to investigate the effects of PNS in treatment. Results indicated that PNS significantly improved typical GPL lesions in mice, such as incomplete intestinal epithelialization and heteroplasia, and also reduced myocardial infarction. At the molecular level, PNS exhibited a bidirectional regulatory role in the GPL-MIRI model. It enhanced the autophagic process in gastric mucosal cells by inhibiting the PI3K/Akt/mTOR signaling pathway, while suppressed excessive autophagy in cardiomyocytes. These findings offer new insights and treatment strategies for managing GPL and MIRI using the TCM compound PNS.

A bibliometric and visualization analysis of global research status and frontiers on autophagy in cardiomyopathies from 2004 to 2023

BACKGROUND

Autophagy is intimately associated with the development of cardiomyopathy, and has received widespread attention in recent years. However, no relevant bibliometric analysis is reported at present. In order to summarize the research status of autophagy in cardiomyopathy and provide direction for future research, we conducted a comprehensive, detailed, and multidimensional bibliometric analysis of the literature published in this field from 2004 to 2023.

METHODS

All literatures related autophagy in cardiomyopathy from 2004 to 2023 were collected from the Web of Science Core Collection (WOSCC), and annual papers, global publication trends and proportion charts were analyzed and plotted using Graphpad price v8.0.2. In addition, CtieSpace (6.2.4R (64 bit) Advanced Edition) and VOSviewer (1.6.18 Edition) were used to analyze and visualize these data.

RESULTS

2279 papers about autophagy in cardiomyopathy were accessed in the WoSCC over the last 20 years, comprising literatures from 70 countries and regions, 2208 institutions, and 10,810 authors. China contributes 56.32% of the total publications, substantially surpassing other countries, while the U.S. is ranked first in frequency of citations. Among the top 10 authors, 6 are from China and 4 are from the United States. Air Force Military Medical University was the institution with the highest number of publications; while journal of molecular and cellular cardiology (62 articles, 2.71% of the total) was the journal with the highest number of papers published in the field. Clustering of co-cited references and temporal clustering analysis showed that ferroptosis, hydrogen sulfide mitophagy, lipid peroxidation, oxidative stress, and SIRT-1 are hot topics and trends in the field. The principal keywords are oxidative stress, heart and heart-failure.

CONCLUSION

The research on autophagy in cardiomyopathy is in the developmental stage. This represents the first bibliometric analysis of autophagy in cardiomyopathy , revealing the current research hotspots and future research directions in this field.

Plekhm2 acts as an autophagy modulator in murine heart and cardiofibroblasts

Plekhm2 is a protein regulating endosomal trafficking and lysosomal distribution. We recently linked a recessive inherited mutation in PLEKHM2 to a familial form of dilated cardiomyopathy and left ventricular non-compaction. These patients' primary fibroblasts exhibited abnormal lysosomal distribution and autophagy impairment. We therefore hypothesized that loss of PLEKHM2 impairs cardiac function via autophagy derangement. Here, we characterized the roles of Plekhm2 in the heart using global Plekhm2 knockout (PLK2-KO) mice and cultured cardiac cells. Compared to littermate controls (WT), young PLK2-KO mice exhibited no difference in heart function or autophagy markers but demonstrated higher basal AKT phosphorylation. Older PLK2-KO mice had body and heart growth retardation and increased LC3II protein levels. PLK2-KO mice were more vulnerable to fasting and, interestingly, impaired autophagy was noted in vitro, in Plekhm2-deficient cardiofibroblasts but not in cardiomyocytes. PLK2-KO hearts appeared to be less sensitive to pathological hypertrophy induced by angiotensin-II compared to WT. Our findings suggest a role of Plekhm2 in murine cardiac autophagy. Plekhm2 deficiency impaired autophagy in cardiofibroblasts, but the autophagy in cardiomyocytes is not critically dependent on Plekhm2. The absence of Plekhm2 in mice appears to promote compensatory mechanism(s) enabling the heart to manage angiotensin-II-induced stress without detrimental consequences.

Exploring the effects of the acaricide cyflumetofen on the vital organs of the honey bee Apis mellifera (Hymenoptera: Apidae) workers

Bees are important for maintaining ecosystems, pollinating crops and producing marketable products. In recent years, a decline in bee populations has been reported, with multifactorial causes, including the intensification of pesticide use in agriculture. Among pesticides, cyflumetofen is an insecticide and acaricide used in apple, coffee and citrus crops, whose main pollinator is the honey bee Apis mellifera. Therefore, this bee is a potential target of cyflumetofen during foraging. This study evaluated the histopathological and cytological damage in the midgut, hypopharyngeal glands and fat body of A. mellifera workers exposed to LC50 of cyflumetofen. The midgut epithelium of exposed bees presented cytoplasmic vacuolization, release of vesicles and cell fragments, which indicate autophagy, increased production of digestive enzymes and cell death, respectively. The cytological analysis of the midgut revealed the dilation of the basal labyrinth and the presence of spherocrystals in the digestive cells. The hypopharyngeal glands produced greater amounts of secretion in treated bees, whereas no changes were observed in the fat body. The results indicate that acute exposure to cyflumetofen negatively affect A. mellifera, causing damage to the midgut and changes in the hypopharyngeal glands, which may compromise the survival and foraging of this pollinator.

Autophagy enhances the differentiation of insulin-producing cells from Wharton's jelly-derived mesenchymal stem cells

Autophagy disruption suppresses insulin production and induces diabetes. The role of autophagy in the differentiation of Wharton's jelly (WJ)-derived mesenchymal stem cells (WJSCs) into insulin-producing cells (IPCs) was investigated in this experimental study. The WJSCs were incubated in a differentiation medium (DM) with or without an autophagy inhibitor (3-methyladenine: 3MA). The differentiation of IPCs was confirmed by flow cytometry analysis of PDX-1 and insulin-positive cells, insulin secretion, and the high expression of β cell-specific genes, Glucose transporter 2 (GLUT-2), and INSULIN. Autophagy has been assessed by calculating the percentage of Acridine orange (AO)-positive cells, expression of autophagy-related genes, and the LC3B/LC3A ratio. β cell-specific genes were up-regulated in the DM group, and 3MA decreased their expression. In the DM+3MA-treated cells, the expression of GLUT-2 and INSULIN genes and insulin secretion decreased compared to the DM group. In cells treated with 3MA, there was a significant decrease in the percentage of PDX-1 and insulin-positive cells compared to 3MA-untreated cells. Additionally, in the group receiving both DM and 3MA treatment, the expression of autophagy-related genes, the LC3B/LC3A protein ratio, and the percentage of AO-stained cells were significantly reduced compared to the group receiving only DM treatment. These findings suggest autophagy is essential for β cell differentiation and insulin secretion.

Mitochondria transplantation alleviates cardiomyocytes apoptosis through inhibiting AMPKα-mTOR mediated excessive autophagy

The disruption of mitochondria homeostasis can impair the contractile function of cardiomyocytes, leading to cardiac dysfunction and an increased risk of heart failure. This study introduces a pioneering therapeutic strategy employing mitochondria derived from human umbilical cord mesenchymal stem cells (hu-MSC) (MSC-Mito) for heart failure treatment. Initially, we isolated MSC-Mito, confirming their functionality. Subsequently, we monitored the process of single mitochondria transplantation into recipient cells and observed a time-dependent uptake of mitochondria in vivo. Evidence of human-specific mitochondrial DNA (mtDNA) in murine cardiomyocytes was observed after MSC-Mito transplantation. Employing a doxorubicin (DOX)-induced heart failure model, we demonstrated that MSC-Mito transplantation could safeguard cardiac function and avert cardiomyocyte apoptosis, indicating metabolic compatibility between hu-MSC-derived mitochondria and recipient mitochondria. Finally, through RNA sequencing and validation experiments, we discovered that MSC-Mito transplantation potentially exerted cardioprotection by reinstating ATP production and curtailing AMPKα-mTOR-mediated excessive autophagy.

Scd1 and monounsaturated lipids are required for autophagy and survival of adipocytes

OBJECTIVE

Exposure of adipocytes to 'cool' temperatures often found in the periphery of the body induces expression of Stearoyl-CoA Desaturase-1 (Scd1), an enzyme that converts saturated fatty acids to monounsaturated fatty acids. The goal of this study is to further investigate the roles of Scd in adipocytes.

METHOD

In this study, we employed Scd1 knockout cells and mouse models, along with pharmacological Scd1 inhibition to dissect the enzyme's function in adipocyte physiology.

RESULTS

Our study reveals that production of monounsaturated lipids by Scd1 is necessary for fusion of autophagosomes to lysosomes and that with a Scd1-deficiency, autophagosomes accumulate. In addition, Scd1-deficiency impairs lysosomal and autolysosomal acidification resulting in vacuole accumulation and eventual cell death. Blocking autophagosome formation or supplementation with monounsaturated fatty acids maintains vitality of Scd1-deficient adipocytes.

CONCLUSION

This study demonstrates the indispensable role of Scd1 in adipocyte survival, with its inhibition in vivo triggering autophagy-dependent cell death and its depletion in vivo leading to the loss of bone marrow adipocytes.

Role and molecular mechanisms of SGLT2 inhibitors in pathological cardiac remodeling (Review)

Cardiovascular diseases are caused by pathological cardiac remodeling, which involves fibrosis, inflammation and cell dysfunction. This includes autophagy, apoptosis, oxidative stress, mitochondrial dysfunction, changes in energy metabolism, angiogenesis and dysregulation of signaling pathways. These changes in heart structure and/or function ultimately result in heart failure. In an effort to prevent this, multiple cardiovascular outcome trials have demonstrated the cardiac benefits of sodium‑glucose cotransporter type 2 inhibitors (SGLT2is), hypoglycemic drugs initially designed to treat type 2 diabetes mellitus. SGLT2is include empagliflozin and dapagliflozin, which are listed as guideline drugs in the 2021 European Guidelines for Heart Failure and the 2022 American Heart Association/American College of Cardiology/Heart Failure Society of America Guidelines for Heart Failure Management. In recent years, multiple studies using animal models have explored the mechanisms by which SGLT2is prevent cardiac remodeling. This article reviews the role of SGLT2is in cardiac remodeling induced by different etiologies to provide a guideline for further evaluation of the mechanisms underlying the inhibition of pathological cardiac remodeling by SGLT2is, as well as the development of novel drug targets.

Pleiotropic attenuating effect of Ginkgo biloba against isoprenaline-induced myocardial infarction via improving Bcl-2/mTOR/ERK1/2/Na+, K+-ATPase activities

Objective

Myocardial infarction (MI) is linked to an imbalance in the supply and demand of blood oxygen in the heart muscles. Beta-blockers and calcium antagonists are just two of the common medications used to treat MI. However, these have reportedly been shown to be either ineffective or to have undesirable side effects. Extract of Ginkgo biloba leaves (GBE), a Chinese herbal product offers special compatibility benefits in therapeutic settings relating to inflammatory diseases and oxidative stress. In order to better understand how GBE affects MI in rats insulted by isoprenaline (ISO), the current study was designed.

Methods

The heart weight index, serum lipid profile, cardiac marker enzymes, endogenous antioxidants [catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), nitrites and malondialdehyde (MDA)], inflammatory mediators [tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6)], immunohistochemical expressions of B-cell lymphoma factor-2 (Bcl-2), extracellular signal-regulated kinase (ERK1/2), and mammalian target of rapamycin (mTOR) and histopathological analysis were used to assess the cardioprotective properties of GBE.

Results

The findings showed that GBE effectively attenuated myocardial infarction by boosting the body's natural antioxidant defense system and reducing the release of inflammatory cytokines as well as heart injury marker enzymes. The expression of Bcl-2, ERK1/2 and mTOR was increased while the histomorphological alterations were reversed.

Conclusion

The cardioprotective effects of GBE may be due to a mechanism involving increased Bcl-2/mTOR/ERK1/2/Na+, K+-ATPase activity.

NADPH oxidase 2 inhibitor GSK2795039 prevents doxorubicin-induced cardiac atrophy by attenuating cardiac sympathetic nerve terminal abnormalities and myocyte autophagy

Doxorubicin is widely used for the treatment of human cancer, but its clinical use is limited by a cumulative dose-dependent cardiotoxicity. However, the mechanism of doxorubicin-induced cardiac atrophy and failure remains to be fully understood. In this study, we tested whether the specific NADPH oxidase 2 (Nox2) inhibitor GSK2795039 attenuates cardiac sympathetic nerve terminal abnormalities and myocyte autophagy, leading to the amelioration of cardiac atrophy and dysfunction in chronic doxorubicin-induced cardiomyopathy. Mice were randomized to receive saline, doxorubicin (2.5 mg/kg, every other day, 6 times) or doxorubicin plus GSK2795039 (2.5 mg/kg, twice a day, 9 weeks). Left ventricular (LV) total wall thickness and LV ejection fraction were decreased in doxorubicin-treated mice compared with saline-treated mice and the decreases were prevented by the treatment of the specific Nox2 inhibitor GSK2795039. The ratio of total heart weight to tibia length and myocyte cross-sectional area were decreased in doxorubicin-treated mice, and the decreases were attenuated by the GSK2795039 treatment. In doxorubicin-treated mice, myocardial Nox2 and 4-hydroxynonenal levels were increased, myocardial expression of GAP43, tyrosine hydroxylase and norepinephrine transporter, markers of sympathetic nerve terminals, was decreased, and these changes were prevented by the GSK2795039 treatment. The ratio of LC3 II/I, a marker of autophagy, and Atg5, Atg12 and Atg12-Atg5 conjugate proteins were increased in doxorubicin-treated mice, and the increases were attenuated by the GSK2795039 treatment. These findings suggest that inhibition of Nox2 by GSK2795039 attenuates cardiac sympathetic nerve terminal abnormalities and myocyte autophagy, thereby ameliorating cardiac atrophy and dysfunction after chronic doxorubicin treatment.

The Clinical Investigation on Varicocele and Sperm Quality in the Tibet an Plateau of China: A Prospectively Planned Retrospective Cohort Study

Varicoceles are a common cause of male infertility, affecting up to 35% of men undergoing fertility evaluations. This study aims to investigate the potential influence of altitude and residence time on the occurrence of varicoceles, as well as on sperm quality and sterility in plateau areas. A total of 168 patients with varicocele were enrolled in the study, and the study population was divided into groups based on their direct exposure to different high altitudes due to their living locations. The internal diameter in Quiet breath (Dr), internal diameter in Valsalva maneuver (Dv), reflux peak value, and reflux time are gradually increased accompanied with altitude elevation and residence time extension. The number of cases above 4,500 m also increased with the severity of varicocele, and the altitude of clinical types was higher than that of subclinical types of varicocele. Especially above 4,500 m, the Dv, Dr, reflux peak value, and reflux time all increased with the severity of varicocele. The severity of varicocele was positively correlated with the residence time in plateau area. Patients with residence time of more than 1 year had higher values of Dr, Dv, differentiation time, reflux peak value, and reflux time than those with residence time of less than 1 year. Compared to 3,650 m, patients with varicocele in 4,500 m also have worse semen quality. Both altitude and residence time are strongly positively related to the severity and incidence rate of varicocele in plateau areas.

Taohong Siwu decoction reduces acute myocardial ischemia-reperfusion injury by promoting autophagy to inhibit pyroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Taohong Siwu decoction (TSD) is a classic traditional Chinese medicine (TCM) prescription used to promote the blood circulation and alleviate blood stasis. TSD consists of Paeonia lactiflora Pall., Conioselinum anthriscoides (H. Boissieu) Pimenov & Kljuykov, Rehmannia glutinosa (Gaertn.) DC., Prunus persica (L.) Batsch, Angelica sinensis (Oliv.) Diels, and Carthamus creticus L. in the ratio of 3:2:4:3:3:2. Studies on the effects of TSD on myocardial ischemia-reperfusion injury (MIRI) from the perspective of autophagy and pyroptosis have not been reported.

AIM OF THE STUDY

Investigate the effect of TSD on MIRI and explore the underlying mechanisms.

MATERIALS AND METHODS

We searched the main components and corresponding potential targets of TSD on The Pharmacology of Traditional Chinese Medicine Systems database for target prediction. We identified targets for MIRI on Online Mendelian Inheritance in Man and GeneCards databases. The intersection of the compound target and disease target was obtained and a protein-protein interaction network constructed. We undertook enrichment analyses using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases. The results of network pharmacology were verified by in vivo experiments in mice.

RESULTS

In mice, TSD significantly reduced the volume of the myocardial infarct, significantly reduced serum levels of cardiac troponin-nI (CTnI), creatine kinase-myocardial band (CK-MB), malonaldehyde (MDA), interleukin (IL)-6, increased the activity of superoxide dismutase (SOD) and IL-10 level, reduced the level of pyroptosis in myocardial tissue, increased the number of autophagosomes, and significantly reduced the fluorescence intensity of apoptosis-associated speck-like protein (ASC), Nod-like receptor protein 3 (NLRP3), and caspase-1. TSD administration increased the protein expression of microtubule-associated protein light chain 3 (LC3), but reduced the protein expression of p62, NLRP3, ASC, caspase-1, cleaved caspase-1, pro-caspase-1, gasdermin D (GSDMD), GSDMD-N-terminal, IL-18, and IL-1β. Administration of 3-Methyladenin could reverse the effect of TSD in inhibiting inflammation and the release of proinflammatory factors.

CONCLUSION

TSD treatment alleviated MIRI by promoting autophagy to suppress activation of the NLRP3 inflammasome and reducing the release of proinflammatory factors.

LncRNA 220, a newly discovered long non-conding RNA inhibiting apoptosis and autophagy in Kupffer cells in LPS-induced endotoxemic mice through the XBP1u-PI3K-AKT pathway

Sepsis is recognized as a potentially fatal condition characterized by acute organ dysfunction resulting from an imbalanced immune response to infection. Acute liver injury (ALI) arises as an inflammatory outcome of immune response dysregulation associated with sepsis. Kupffer cells, which are liver-specific macrophages, are known to have a significant impact on ALI, although the precise regulatory mechanism remains unclear. Numerous studies have showcased the regulatory impact of long non-coding RNAs (lncRNAs) on the progression of diverse ailments, yet their precise regulatory mechanisms remain predominantly unexplored. In this study, a novel long non-coding RNA (lncRNA), referred to as lncRNA 220, was discovered using high-throughput sequencing. The expression of lncRNA 220 was found to be significantly elevated in the livers of mice with lipopolysaccharide (LPS)-induced endotoxemia, specifically during the 8-hour time period. Furthermore, in Kupffer cells treated with LPS, lncRNA 220 was observed to inhibit apoptosis and autophagy by activating the PI3K-AKT-mTORC1 pathway. This effect was achieved through the reduction of X-box protein 1 unspliced (Xbp1u) mRNA stability and suppression of its translation in the context of endoplasmic reticulum stress (ERS). Ultimately, this intervention mitigated the progression of LPS-induced ALI. To summarize, our study establishes lncRNA 220 as a newly identified regulator that suppresses apoptosis and autophagy in Kupffer cells subjected to LPS treatment, indicating its potential as a molecular target for ALI in endotoxemic mice.

Downregulation of salusins alleviates hypertrophic cardiomyopathy via attenuating oxidative stress and autophagy

INTRODUCTION

Salusins, which are translated from the alternatively spliced mRNA of torsin family 2 member A (TOR2A), play a vital role in regulation of various cardiovascular diseases. However, it remains unclear precisely regarding their roles in hypertrophic cardiomyopathy (HCM). Therefore, this study was conducted to explore therapeutic effect and the underlying mechanisms of salusins on HCM.

MATERIAL AND METHODS

In vivo experiments, Sprague-Dawley rats were used to induce HCM model by angiotensin (Ang) II infusion for 4 weeks. The rats were randomly divided into four groups, namely, Saline + Control shRNA (n = 7), Ang II + Control shRNA (n = 8), Saline + TOR2A shRNA (n = 7), and Ang II + TOR2A shRNA groups (n = 8). After HCM induction, doppler echocardiography is recommended to evaluate heart function. In vitro experiments, primary neonatal rat cardiomyocytes (NRCMs) and cardiac fibroblasts (NRCFs) were obtained from newborn rats, and were treated with Ang II (10-6 M) for 24 h.

RESULTS

After treatment with Ang II, levels of salusin-α and salusin-β were elevated in serum and cardiac tissues of rats and in the neonatal rat cardiomyocytes and cardiac fibroblasts. Downregulation of salusins alleviated the Ang II-induced cardiac hypertrophy by suppressing the increased atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and beta-myosin heavy chain (β-MHC) and cardiac fibrosis by blocking collagen I, collagen III and transforming growth factor-beta (TGF-β), and it also attenuated oxidative stress by suppressing the increased reactive oxygen species (ROS) and malondialdehyde (MDA) levels and reversing the decreased superoxide dismutase (SOD) activity and autophagy by inhibiting the increased microtubule-associated protein light chain 3B (LC3B), Beclin1, autophagy related gene (Atg) 3 and Atg5 in the cardiac tissues of Ang II-infused rats and in the Ang II-treated NRCMs.

CONCLUSIONS

All these findings suggest that the levels of salusins were elevated in the HCM, and targeting of salusins contributes to alleviation of cardiac hypertrophy and fibrosis probably via attenuating oxidative stress and autophagy. Accordingly, targeting of salusins may be a strategy for HCM therapy.

High-Density Lipoproteins at the Interface between the NLRP3 Inflammasome and Myocardial Infarction

Despite significant therapeutic advancements, morbidity and mortality following myocardial infarction (MI) remain unacceptably high. This clinical challenge is primarily attributed to two significant factors: delayed reperfusion and the myocardial injury resulting from coronary reperfusion. Following reperfusion, there is a rapid intracellular pH shift, disruption of ionic balance, heightened oxidative stress, increased activity of proteolytic enzymes, initiation of inflammatory responses, and activation of several cell death pathways, encompassing apoptosis, necroptosis, and pyroptosis. The inflammatory cell death or pyroptosis encompasses the activation of the intracellular multiprotein complex known as the NLRP3 inflammasome. High-density lipoproteins (HDL) are endogenous particles whose components can either promote or mitigate the activation of the NLRP3 inflammasome. In this comprehensive review, we explore the role of inflammasome activation in the context of MI and provide a detailed analysis of how HDL can modulate this process.

Insulin-like growth factor-1 reduces cardiac autosis through decreasing AMPK/FOXO1 signaling and Na+/K+-ATPase-Beclin-1 interaction

Introduction

Insulin-like growth factor-1 (IGF-1) promotes survival and inhibits cardiac autophagy disruption.

Methods

Male Wistar rats were treated with IGF-1 (50 µg/kg), and 24 h after injection hearts were excised. The level of interaction between Beclin-1 and the α1 subunit of sodium/potassium-adenosine triphosphates (Na+/K+-ATPase), and phosphorylated forms of IGF-1 receptor/insulin receptor (IGF-1R/IR), forkhead box protein O1 (FOXO1) and AMP-activated protein kinase (AMPK) were measured.

Results

The results indicate that IGF-1 decreased Beclin-1's association with Na+/K+-ATPase (p < 0.05), increased IGF-1R/IR and FOXO1 phosphorylation (p < 0.05), and decreased AMPK phosphorylation (p < 0.01) in rats' hearts.

Conclusions

The new IGF-1 therapy may control autosis and minimize cardiomyocyte mortality.

Neutrophil extracellular traps in central nervous system (CNS) diseases

Excessive induction of inflammatory and immune responses is widely considered as one of vital factors contributing to the pathogenesis and progression of central nervous system (CNS) diseases. Neutrophils are well-studied members of inflammatory and immune cell family, contributing to the innate and adaptive immunity. Neutrophil-released neutrophil extracellular traps (NETs) play an important role in the regulation of various kinds of diseases, including CNS diseases. In this review, current knowledge on the biological features of NETs will be introduced. In addition, the role of NETs in several popular and well-studied CNS diseases including cerebral stroke, Alzheimer's disease, multiple sclerosis, amyotrophic lateral sclerosis (ALS), and neurological cancers will be described and discussed through the reviewing of previous related studies.

Golgi Protein 73 Promotes LPS-Induced Cardiac Dysfunction via Mediating Myocardial Apoptosis and Autophagy

ABSTRACT

Sepsis-induced cardiac dysfunction represents a major cause of high mortality in intensive care units with limited therapeutic options. Golgi protein 73 (GP73) has been implicated in various diseases. However, the role of GP73 in lipopolysaccharide (LPS)-induced cardiac dysfunction is unclear. In this study, we established a sepsis-induced cardiac dysfunction model by LPS administration in wild-type and GP73 knockout ( GP73-/- ) mice. We found that GP73 was increased in LPS-treated mouse hearts and LPS-cultured neonatal rat cardiomyocytes (NRCMs). Knockout of GP73 alleviated myocardial injury and improved cardiac dysfunction. Moreover, depletion of GP73 in NRCMs relieved LPS-induced cardiomyocyte apoptosis and activated myocardial autophagy. Therefore, GP73 is a negative regulator in LPS-induced cardiac dysfunction by promoting cardiomyocyte apoptosis and inhibiting cardiomyocyte autophagy.

Mechanisms and Optimization Strategies of Paracrine Exosomes from Mesenchymal Stem Cells in Ischemic Heart Disease

The morbidity and mortality of myocardial infarction (MI) are increasing worldwide. Mesenchymal stem cells (MSCs) are multipotent stem cells with self-renewal and differentiation capabilities that are essential in tissue healing and regenerative medicine. However, the low implantation and survival rates of transplanted cells hinder the widespread clinical use of stem cells. Exosomes are naturally occurring nanovesicles that are secreted by cells and promote the repair of cardiac function by transporting noncoding RNA and protein. In recent years, MSC-derived exosomes have been promising cell-free treatment tools for improving cardiac function and reversing cardiac remodeling. This review describes the biological properties and therapeutic potential of exosomes and summarizes some engineering approaches for exosomes optimization to enhance the targeting and therapeutic efficacy of exosomes in MI.

Bibliometric and visual analysis of doxorubicin-induced cardiotoxicity

Background: Doxorubicin-induced cardiotoxicity represents a prevalent adverse effect encountered in patients undergoing treatment with doxorubicin. To date, there has been no bibliometric study to summarize the field of doxorubicin-induced cardiotoxicity. In our study, we aim to determine the current status and frontiers of doxorubicin-induced cardiotoxicity by bibliometric analysis. Methods: The documents concerning doxorubicin-induced cardiotoxicity are obtained from the Web of Science Core Collection database (WOSCC), and VOSviewer 1.6.16, CiteSpace 5.1.3 and the WOSCC's literature analysis wire were used to conduct the bibliometric analysis. Results: In total, 7,021 publications were encompassed, which are produced by 37,152 authors and 6,659 organizations, 1,323 journals, and 101 countries/regions. The most productive author, institution, country and journal were Bonnie Ky with 35 publications, University of Texas with 190 documents, the United States with 1,912 publications, and PLOS ONE with 120 documents. The first high-cited article was published in the NEJM with 8,134 citations authored by DJ Slamon et al., in 2001. For keyword analysis, there are four clusters depicted in distinct directions. The keywords in the red cluster are oxidative stress, apoptosis, and cardiomyopathy. The keywords in the green cluster are cardiotoxicity, heart failure, and anthracycline. The keywords in the blue cluster are chemotherapy, trastuzumab, and paclitaxel. The keywords in the purple cluster are doxorubicin, adriamycin, and cancer. Most of the documents were derived from the United States, China and Italy (4,080/7,021, 58.1%). The number of studies from other countries should be increased. Conclusion: In conclusion, the main research hotspots and frontiers in the field of doxorubicin-induced cardiotoxicity include the role of doxorubicin in cardiotoxicity, the mechanisms underlying doxorubicin-induced cardiotoxicity, and the development of treatment strategies for doxorubicin-induced cardiotoxicity. More studies are needed to explore the mechanisms and treatment of doxorubicin-induced cardiotoxicity.

BAK contributes critically to necrosis and infarct generation during reperfused myocardial infarction

At least seven cell death programs are activated during myocardial infarction (MI), but which are most important in causing heart damage is not understood. Two of these programs are mitochondrial-dependent necrosis and apoptosis. The canonical function of the pro-cell death BCL-2 family proteins BAX and BAK is to mediate permeabilization of the outer mitochondrial membrane during apoptosis allowing apoptogen release. BAX has also been shown to sensitize cells to mitochondrial-dependent necrosis, although the underlying mechanisms remain ill-defined. Genetic deletion of Bax or both Bax and Bak in mice reduces infarct size following reperfused myocardial infarction (MI/R), but the contribution of BAK itself to cardiomyocyte apoptosis and necrosis and infarction has not been investigated. In this study, we use Bak-deficient mice and isolated adult cardiomyocytes to delineate the role of BAK in the pathogenesis of infarct generation and post-infarct remodeling during MI/R and non-reperfused MI. Generalized homozygous deletion of Bak reduced infarct size ∼50% in MI/R in vivo, which was attributable primarily to decreases in necrosis. Protection from necrosis was also observed in BAK-deficient isolated cardiomyocytes suggesting that the cardioprotection from BAK loss in vivo is at least partially cardiomyocyte-autonomous. Interestingly, heterozygous Bak deletion, in which the heart still retains ∼28% of wild type BAK levels, reduced infarct size to a similar extent as complete BAK absence. In contrast to MI/R, homozygous Bak deletion did not attenuate acute infarct size or long-term scar size, post-infarct remodeling, cardiac dysfunction, or mortality in non-reperfused MI. We conclude that BAK contributes significantly to cardiomyocyte necrosis and infarct generation during MI/R, while its absence does not appear to impact the pathogenesis of non-reperfused MI. These observations suggest BAK may be a therapeutic target for MI/R and that even partial pharmacological antagonism may provide benefit.

IR-820@NBs Combined with MG-132 Enhances the Anti-Hepatocellular Carcinoma Effect of Sonodynamic Therapy

Purpose

Sonodynamic therapy (SDT) is a promising and significant measure for the treatment of tumors. However, the internal situation of hepatocellular carcinoma (HCC) is complex, separate SDT treatment is difficult to play a good therapeutic effect. Here, we used SDT combined with MG-132 to mediate apoptosis and autophagy of HCC cells to achieve the purpose of treatment of cancer.

Methods

To determine the generated reactive oxygen species (ROS) and the change of mitochondrial membrane potential (ΔΨm), HepG2 cells were stained by 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) and 5,5',6,6'-Tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine iodide (JC-1) staining to determine the IR-820@NBs-mediated SDT to achieve HCC therapy through the mitochondrial pathway. Cell counting kit 8 (CCK-8) assay and flow cytometry were used to detect cell viability and apoptosis rate of HepG2 cells. Autophagy was detected by mCherry-GFP-LC3B fluorescence labeling. Chloroquine (Cq) pretreatment was used to explore the relationship between autophagy and apoptosis. To detect the ability of HepG2 cells migration and invasion, cell scratch assay and transwell assay were used.

Results

The successfully prepared IR-820@NBs could effectively overcome the shortcomings of IR-820 and induce lethal levels of ROS by ultrasound irradiation. As a dual agonist of apoptosis and autophagy, MG-132 could effectively enhance the efficacy of SDT in the process of treating HCC. After pre-treatment with Cq, the cell activity increased and the level of apoptosis decreased, which proved that apoptosis and autophagy were induced by combined therapy, autophagy, and apoptosis have the synergistic anti-tumor effect, and part of apoptosis was autophagy-dependent. After combined therapy, the activity and invasive ability of HCC cells decreased significantly.

Conclusion

SDT combined with MG-132 in the process of treating liver cancer could effectively induce apoptosis and autophagy anti-tumor therapy, which is helpful to the research of new methods to treat liver cancer.

SCD1 and monounsaturated lipids are required for autophagy and survival of adipocytes

Exposure of adipocytes to 'cool' temperatures often found in the periphery of the body induces expression of Stearoyl-CoA Desaturase-1 (SCD1), an enzyme that converts saturated fatty acids to monounsaturated fatty acids. In this study, we employed Scd1 knockout cells and mouse models, along with pharmacological SCD1 inhibition, to investigate further the roles of SCD1 in adipocytes. Our study reveals that production of monounsaturated lipids by SCD1 is necessary for fusion of autophagosomes to lysosomes and that with a SCD1-deficiency, autophagosomes accumulate. In addition, SCD1-deficiency impairs lysosomal and autolysosomal acidification resulting in vacuole accumulation and eventual cell death. Blocking autophagosome formation or supplementation with monounsaturated fatty acids maintains vitality of SCD1-deficient adipocytes. Taken together, our results demonstrate that in vitro inhibition of SCD1 in adipocytes leads to autophagy-dependent cell death, and in vivo depletion leads to loss of bone marrow adipocytes.

Tricin promoted ATG-7 dependent autophagic degradation of α-synuclein and dopamine release for improving cognitive and motor deficits in Parkinson's disease

Tricin, a natural nontoxic flavonoid distributed in grasses and euphorbia plants, has been reported to scavenge free radicals, possess anti-inflammatory and antioxidative effects. However, its autophagic effect on Parkinson's disease (PD) has not been elucidated. By adopting cellular and C. elegans models of PD, the autophagic effect of tricin was identified based on the level of autophagy markers (LC3-II and p62). Besides, the pharmacological effects on neurotransmitters (dopamine), inflammatory cytokines (IFN γ, TNFα, MCP-1, IL-10, IL-6 and IL-17A), histology (hematoxylin & eosin and Nissl staining) and behavioural pathology (open-field test, hindlimb clasping, Y-maze, Morris water-maze and nest building test) were also confirmed in the A53T-α-synuclein transgenic PD mouse model. Further experiments demonstrated that tricin induced autophagic flux and lowered the level of α-synuclein through AMPK-p70s6K- and ATG7-dependent mechanism. Compared to the existing clinical PD drugs, tricin mitigated pathogenesis and symptoms of PD with no observable side effects. In summary, tricin is proposed as a potential adjuvant remedy or nutraceutical for the prevention and treatment of PD.

Impact of Cerium Oxide Nanoparticles on Metabolic, Apoptotic, Autophagic and Antioxidant Changes in Doxorubicin-Induced Cardiomyopathy: Possible Underlying Mechanisms

Background

In the current study, the effects of cerium oxide nanoparticles (nanocerium; NC) on doxorubicin (DOX)-induced cardiomyopathy and its possible underlying mechanisms were addressed.

Methods

32 adult male rats were allocated into 4 groups; i) control group, ii) NC group; rats received NC (0.2 mg/kg, i.p., daily), iii) DOX group; rats received DOX 4 mg/kg (2 injections with a 14-day interval), and iv) DOX+NC group as DOX but rats received NC. At the end of the experiment, ECG and ECHO recordings and assessments of the levels of cardiac enzymes (CK-MB, LDH), and myocardial oxidative stress (MDA, catalase, and GSH), the expression of LC3 and beclin1 (markers of autophagy), caspase3 (marker of apoptosis) by immunohistochemistry, the expression of acetyl-CoA carboxylase alpha (ACCA) by PCR, and 5'adenosine monophosphate-activated protein kinase (AMPK) levels in the heart tissues were performed.

Results

The DOX group displayed a prolonged corrected QT interval, an increase in cardiac enzymes (CK-MB and LDH), myocardial oxidative stress (high MDA with low catalase and GSH), expression of ACCA, caspase-3, beclin1, and LC3 in myocardial tissues, with reduction in myocardial AMPK levels, and myocardial contractility (low ejection fraction, and fractional shortening). On the other hand, administration of NC with DOX resulted in significant improvement of all studied parameters.

Conclusion

NC offers a cardioprotective effect against DOX-induced cardiomyopathy. This effect might be due to its antioxidant and antiapoptotic effects as well as to the modulation of autophagy and metabolic dysfunctions induced by DOX in the heart tissues.

Porphyromonas gingivalis, a periodontal pathogen, impairs post-infarcted myocardium by inhibiting autophagosome-lysosome fusion

While several previous studies have indicated the link between periodontal disease (PD) and myocardial infarction (MI), the underlying mechanisms remain unclear. Autophagy, a cellular quality control process that is activated in several diseases, including heart failure, can be suppressed by Porphyromonas gingivalis (P.g.). However, it is uncertain whether autophagy impairment by periodontal pathogens stimulates the development of cardiac dysfunction after MI. Thus, this study aimed to investigate the relationship between PD and the development of MI while focusing on the role of autophagy. Neonatal rat cardiomyocytes (NRCMs) and MI model mice were inoculated with wild-type P.g. or gingipain-deficient P.g. to assess the effect of autophagy inhibition by P.g. Wild-type P.g.-inoculated NRCMs had lower cell viability than those inoculated with gingipain-deficient P.g. This study also revealed that gingipains can cleave vesicle-associated membrane protein 8 (VAMP8), a protein involved in lysosomal sensitive factor attachment protein receptors (SNAREs), at the 47th lysine residue, thereby inhibiting autophagy. Wild-type P.g.-inoculated MI model mice were more susceptible to cardiac rupture, with lower survival rates and autophagy activity than gingipain-deficient P.g.-inoculated MI model mice. After inoculating genetically modified MI model mice (VAMP8-K47A) with wild-type P.g., they exhibited significantly increased autophagy activation compared with the MI model mice inoculated with wild-type P.g., which suppressed cardiac rupture and enhanced overall survival rates. These findings suggest that gingipains, which are virulence factors of P.g., impair the infarcted myocardium by cleaving VAMP8 and disrupting autophagy. This study confirms the strong association between PD and MI and provides new insights into the potential role of autophagy in this relationship.

Autophagy in Heart Failure: Insights into Mechanisms and Therapeutic Implications

Autophagy, a dynamic and complex process responsible for the clearance of damaged cellular components, plays a crucial role in maintaining myocardial homeostasis. In the context of heart failure, autophagy has been recognized as a response mechanism aimed at counteracting pathogenic processes and promoting cellular health. Its relevance has been underscored not only in various animal models, but also in the human heart. Extensive research efforts have been dedicated to understanding the significance of autophagy and unravelling its complex molecular mechanisms. This review aims to consolidate the current knowledge of the involvement of autophagy during the progression of heart failure. Specifically, we provide a comprehensive overview of published data on the impact of autophagy deregulation achieved by genetic modifications or by pharmacological interventions in ischemic and non-ischemic models of heart failure. Furthermore, we delve into the intricate molecular mechanisms through which autophagy regulates crucial cellular processes within the three predominant cell populations of the heart: cardiomyocytes, cardiac fibroblasts, and endothelial cells. Finally, we emphasize the need for future research to unravel the therapeutic potential associated with targeting autophagy in the management of heart failure.

Diversity and complexity of cell death: a historical review

Death is the inevitable fate of all living organisms, whether at the individual or cellular level. For a long time, cell death was believed to be an undesirable but unavoidable final outcome of nonfunctioning cells, as inflammation was inevitably triggered in response to damage. However, experimental evidence accumulated over the past few decades has revealed different types of cell death that are genetically programmed to eliminate unnecessary or severely damaged cells that may damage surrounding tissues. Several types of cell death, including apoptosis, necrosis, autophagic cell death, and lysosomal cell death, which are classified as programmed cell death, and pyroptosis, necroptosis, and NETosis, which are classified as inflammatory cell death, have been described over the years. Recently, several novel forms of cell death, namely, mitoptosis, paraptosis, immunogenic cell death, entosis, methuosis, parthanatos, ferroptosis, autosis, alkaliptosis, oxeiptosis, cuproptosis, and erebosis, have been discovered and advanced our understanding of cell death and its complexity. In this review, we provide a historical overview of the discovery and characterization of different forms of cell death and highlight their diversity and complexity. We also briefly discuss the regulatory mechanisms underlying each type of cell death and the implications of cell death in various physiological and pathological contexts. This review provides a comprehensive understanding of different mechanisms of cell death that can be leveraged to develop novel therapeutic strategies for various diseases.

LncRNA 220: A Novel Long Non-Coding RNA Regulates Autophagy and Apoptosis in Kupffer Cells via the miR-5101/PI3K/AKT/mTOR Axis in LPS-Induced Endotoxemic Liver Injury in Mice

Sepsis is a severe medical condition distinguished by immune systematic dysfunction and multiple organic injury, or even failure, resulting from an acute systemic inflammatory response. Acute liver injury (ALI) could be considered as a notable inflammatory outcome of sepsis. Studies have demonstrated the essential roles played by long non-coding RNAs (lncRNAs) in mediating the processes of various diseases, including their ability to engage in interactions with microRNAs (miRNAs) as complexes of competing endogenous RNA (ceRNA) to modulate signaling pathways. In this study, a newly discovered lncRNA, named 220, was identified to function in regulating autophagy and apoptosis in Kupffer cells treated with lipopolysaccharide (LPS). This was achieved through sponging miR-5101 as a ceRNA complex, as identified via high-throughput sequencing. The expression of 220 was found to be significantly different in the hepatic tissues of endotoxemic mice that were treated with LPS for 8 h, ultimately modulating the ALI process. Our studies have collectively demonstrated that 220 is a novel regulator that acts on LPS-induced autophagy and apoptosis in Kupffer cells, thereby mediating the ALI process induced by LPS. Furthermore, the validation of our findings using clinical databases suggests that 220 could potentially serve as a molecular target of clinical, diagnostic, and therapeutic significance in septic liver injury.

TanshinoneⅡA inhibits excessive autophagy and protects myocardium against ischemia/reperfusion injury via 14-3-3η/Akt/Beclin1 pathway

Excessive autophagy induced by reperfusion is one of the causes of severe myocardial injury. Tanshinone IIA (TSN) protects the myocardium against ischemia/reperfusion (I/R) injury. The mechanism by which the inhibition of excessive autophagy contributes to the myocardial protection by TSN is unclear. The protective effects and mechanisms of TSN were studied in H9c2 cells and rats after anoxia/reoxygenation (A/R)-or I/R-induced myocardial injury. The results showed that after the injury, cell viability decreased, lactate dehydrogenase and caspase 3 activity and apoptosis increased, and autophagy was excessively activated. Further, redox imbalance and energy stress, mitochondrial dysfunction, reduced myocardial function, increased infarct area, and severely damaged morphology were observed in rats. TSN increased 14-3-3η expression and regulated Akt/Beclin1 pathway, inhibited excessive autophagy, and significantly reversed the functional, enzymological and morphological indexes in vivo and in vitro. However, the protective effects of TSN were mimicked by 3-methyladenine (an autophagy inhibitor) and were attenuated by pAD/14-3-3η-shRNA, API-2 (an Akt inhibitor), and rapamycin (an autophagy activator). In conclusion, TSN could increase 14-3-3η expression and regulate Akt/Beclin1 pathway, inhibit excessive autophagy, maintain the mitochondrial function, improve energy supply and redox equilibrium, alleviate apoptosis, and ultimately protect myocardium against I/R injury.

Mitochondrial calcium and reactive oxygen species in cardiovascular disease

Cardiomyocytes are one of the most mitochondria-rich cell types in the body, with ∼30-40% of the cell volume being composed of mitochondria. Mitochondria are well established as the primary site of adenosine triphosphate (ATP) generation in a beating cardiomyocyte, generating up to 90% of its ATP. Mitochondria have many functions in the cell, which could contribute to susceptibility to and development of cardiovascular disease (CVD). Mitochondria are key players in cell metabolism, ATP production, reactive oxygen species (ROS) production, and cell death. Mitochondrial calcium (Ca2+) plays a critical role in many of these pathways, and thus the dynamics of mitochondrial Ca2+ are important in regulating mitochondrial processes. Alterations in these varied and in many cases interrelated functions play an important role in CVD. This review will focus on the interrelationship of mitochondrial energetics, Ca2+, and ROS and their roles in CVD. Recent insights into the regulation and dysregulation of these pathways have led to some novel therapeutic approaches.

Doxorubicin downregulates autophagy to promote apoptosis-induced dilated cardiomyopathy via regulating the AMPK/mTOR pathway

The broad-spectrum antineoplastic drug doxorubicin (DOX) has one of the most serious chronic side effects on the heart, dilated cardiomyopathy, but the precise molecular mechanisms underlying disease progression subsequent to long latency periods remain puzzling. Here, we established a model of DOX-induced dilated cardiomyopathy. In a cardiac cytology exploration, we found that differentially expressed genes in the KEGG signaling pathway enrichment provided a novel complex network of mTOR bridging autophagy and oxidative stress. Validation results showed that DOX caused intracellular reactive oxygen species accumulation in cardiomyocytes, disrupted mitochondria, led to imbalanced intracellular energy metabolism, and triggered cardiomyocyte apoptosis. Apoptosis showed a negative correlation with DOX-regulated cardiomyocyte autophagy. To evaluate whether the inhibition of mTOR could upregulate autophagy to protect cardiomyocytes, we used rapamycin to restore autophagy depressed by DOX. Rapamycin increased cardiomyocyte survival by easing the autophagic flux blocked by DOX. In addition, rapamycin reduced oxidative stress, prevented mitochondrial damage, and restored energy metabolic homeostasis in DOX-treated cardiomyocytes. In vivo, we used metformin (Met) which is an AMPK activator to protect cardiac tissue to alleviate DOX-induced dilated cardiomyopathy. In this study, Met significantly attenuated the oxidative stress response of myocardial tissue caused by DOX and activated cardiomyocyte autophagy to maintain cardiomyocyte energy metabolism and reduce cardiomyocyte apoptosis by downregulating mTOR activity. Overall, our study revealed the role of autophagy and apoptosis in DOX-induced dilated cardiomyopathy and demonstrated the potential role of regulation of the AMPK/mTOR axis in the treatment of DOX-induced dilated cardiomyopathy.

Exendin-4 alleviates myocardial ischemia reperfusion injury by enhancing autophagy through promoting nuclear translocation of TFEB

Ischemia-reperfusion (I/R) injury (IRI) is a common clinical consequence of myocardial infarction. Exendin-4 is a glucagon-like peptide-1 (GLP-1) analog that has been demonstrated to alleviate myocardial IRI. Autophagy, a lysosomal pathway balancing cell survival and cell death, is engaged in myocardial IRI. However, whether exendin-4 exerts a protective effect on myocardial IRI by modulating autophagy remains elusive. Herein, we investigated the effect of exendin-4 on autophagic flux and explored the underlying molecular mechanisms. Our data revealed that the autophagic flux was blocked in the human ventricular cardiomyocyte cell lines (AC16) subjected to oxygen glucose deprivation/reoxygenation (OGD/R) in vitro. Exendin-4 pre-treatment markedly restored the blocked autophagic flux induced by OGD/R through promoting nuclear translocation of TFEB and transcription of genes involving autophagy initiation, the effect of which was reversed by TFEB knockdown. The restoration of autophagic flux contributed to multiple beneficial effects of exendin-4 in cardiomyocytes, including reduction of oxidative stress, preservation of mitochondrial network as well as inhibition of cytochrome c leakage from mitochondrial permeability transition pore (MPTP) and the resulting apoptosis. Moreover, the administration of exendin-4 reduced infarct size and preserved cardiac function through its anti-apoptosis and antioxidative effects in vivo. These results shed some light on understanding the novel mechanism of exendin-4 as a protective agent against myocardial IRI.

Stomatin-like protein 2 deficiency exacerbates adverse cardiac remodeling

Myocardial fibrosis, oxidative stress, and autophagy both play key roles in the progression of adverse cardiac remodeling. Stomatin-like protein 2 (SLP-2) is closely related to mitochondrial function, but little is known about its role and mechanism in cardiac remodeling. We developed doxorubicin (Dox), angiotensin (Ang) II, and myocardial ischemia-reperfusion (I/R) injury induced cardiac remodeling model and Dox treated H9C2 cell injury model using SLP-2 knockout (SLP-2^-/-) mice and H9C2 cells with low SLP-2 expression. We first examined cardiac functional and structural changes as well as levels of oxidative stress, apoptosis and autophagy. We found that SLP-2 deficiency leads to decreased cardiac function and promotes myocardial fibrosis. After Dox and Ang II treatment, SLP-2 deficiency further aggravated myocardial fibrosis, increased myocardial oxidative stress and apoptosis, and activated autophagy by inhibiting PI3K-Akt-mTOR signaling pathway, ultimately exacerbating adverse cardiac remodeling. Similarly, SLP-2 deficiency further exacerbates adverse cardiac remodeling after myocardial I/R injury. Moreover, we extracted cardiomyocyte mitochondria for proteomic analysis, suggesting that SLP-2 deficiency may be involved in myocardial I/R injury induced adverse cardiac remodeling by influencing ubiquitination of intramitochondrial proteins. In addition, the oxidative stress, apoptosis and autophagy levels of H9C2 cells with low SLP-2 expression were further enhanced, and the PI3K-Akt-mTOR signaling pathway was further inhibited under Dox stimulation. Our results suggest that SLP-2 deficiency promotes myocardial fibrosis, disrupts normal mitochondrial function, overactivates autophagy via PI3K-Akt-mTOR signaling pathway, affects the level of ubiquitination, leads to irreversible myocardial damage, and ultimately exacerbates adverse cardiac remodeling.

The role of the Hippo pathway in autophagy in the heart

The Hippo pathway, an evolutionarily conserved signalling mechanism, controls organ size and tumourigenesis. Increasing lines of evidence suggest that autophagy, an important mechanism of lysosome-mediated cellular degradation, is regulated by the Hippo pathway, which thereby profoundly affects cell growth and death responses in various cell types. In the heart, Mst1, an upstream component of the Hippo pathway, not only induces apoptosis but also inhibits autophagy through phosphorylation of Beclin 1. YAP/TAZ, transcription factor co-factors and the terminal effectors of the Hippo pathway, affect autophagy through transcriptional activation of TFEB, a master regulator of autophagy and lysosomal biogenesis. The cellular abundance of YAP is negatively regulated by autophagy and suppression of autophagy induces accumulation of YAP, which, in turn, acts as a feedback mechanism to induce autophagosome formation. Thus, the Hippo pathway and autophagy regulate each other, thereby profoundly affecting cardiomyocyte survival and death. This review discusses the interaction between the Hippo pathway and autophagy and its functional significance during stress conditions in the heart and the cardiomyocytes therein.

Cardioprotective effect of crude polysaccharide fermented by Trametes Sanguinea Lyoyd on doxorubicin-induced myocardial injury mice

Doxorubicin (DOX) is a broad-spectrum anti-tumor drug, but its clinical application is greatly limited because of the cardiotoxicity. Thus, exploration of effective therapies against DOX-induced cardiotoxicity is necessary. The aim of this study is to investigate the effects and possible mechanisms of Trametes Sanguinea Lyoyd fermented crude polysaccharide (TSLFACP) against DOX-induced cardiotoxicity. We investigated the protective effects of TSLFACP on myocardial injury and its possible mechanisms using two in vitro cells of DOX-treated cardiomyocytes H9C2 and embryonic myocardial cell line CCC-HEH-2 and a in vivo mouse model of DOX-induced myocardial injury. We found that TSLFACP could reverse DOX-induced toxicity in H9C2 and CCC-HEH-2 cells. Similarly, we found that when pretreatment with TSLFACP (200 mg/kg, i.g.) daily for 6 days, DOX-induced myocardial damage was attenuated, including the decrease in serum myocardial injury index, and the amelioration in cardiac histopathological morphology. Additionally, immunohistochemistry and western blotting were used to identify the underlying and possible signal pathways. We found that TSLFACP attenuated the expression of LC3-II, Beclin-1 and PRAP induced by DOX. In conclusion, our results demonstrated that TSLFACP could protect against DOX-induced cardiotoxicity by inhibiting autophagy and apoptosis.