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

Curcumin attenuates myocardial ischemia‑reperfusion‑induced autophagy‑dependent ferroptosis via Sirt1/AKT/FoxO3a signaling

Curcumin (Cur) effectively attenuates myocardial ischemia/reperfusion injury (MIRI). MIRI has a complex mechanism and is associated with autophagy‑dependent ferroptosis. Therefore, the present study aimed to determine whether autophagy‑dependent ferroptosis occurs in MIRI and assess the mechanism of Cur in attenuating MIRI. The study was conducted on a Sprague‑Dawley rat MIRI model and H9c2 cell anoxia/reoxygenation (A/R) injury model. The effect of Cur pretreatment on A/R or MIRI induced autophagy‑dependent ferroptosis and its molecular mechanism were investigated. Protein expression, lysosomal, reactive oxygen species, Fe2+, oxidative systems, mitochondrial function, subcellular localization of molecules, and cardiac function assays will be employed. Cur decreased MIRI; improved myocardial histopathology; increased cardiomyocyte viability; inhibited ferroptosis, apoptosis and autophagy; reduced infarct size and maintained cardiac function. MIRI decreased silent information regulator 1 (Sirt1), decreased AKT and forkhead box O3A (FoxO3a) phosphorylation, leading to FoxO3a entry into the nucleus to activate translation of autophagy‑related genes and inducing ferroptosis, apoptosis and autophagy. However, Cur pretreatment activated AKT and FoxO3a phosphorylation via Sirt1, thereby transporting FoxO3a out of the nucleus, reducing autophagy‑related gene translation and attenuating MIRI‑induced ferroptosis, apoptosis and autophagy. Of note, the silencing of Sirt1 and administration of triciribine (an AKT inhibitor) both eliminated the protective effect of Cur. Thus, Cur maintained cardiomyocyte function by inhibiting autophagy‑dependent ferroptosis via Sirt1/AKT/FoxO3a signaling.

Signaling pathways behind the biological effects of tanshinone IIA for the prevention of cancer and cardiovascular diseases

Tanshinone IIA (Tan IIA) is a well-known fat-soluble diterpenoid found in Salvia miltiorrhiza, recognized for its various biological effects. The molecular signaling pathways of Tan IIA have been investigated in different diseases, including the anti-inflammatory, hepatoprotective, renoprotective, neuroprotective effects, and fibrosis prevention. This article provides a brief overview of the signaling pathways related to anti-cancer and cardioprotective effects of Tan IIA. It shows that Tan IIAs anti-cancer ability has good expectation through multiplicity mechanisms affecting various aspects' tumor biology. The major pathways involved in its anti-cancer effects include inhibition of PI3/Akt, MAPK, and p53/p21 signaling which leads to enhancement of immune responses and increased radiation sensitivity. Some essential pathways responsible for cardioprotective effects induced by Tan IIA are PI3/AKT activation, MAPK, and SIRT1 promoting protection against ischemia/reperfusion injury in myocardial cells as well as inhibiting pathological remodeling processes. Finally, the article underscores the complex and specific signaling pathways influenced by Tan IIA. The PI3/Akt and MAPK pathways play critical roles in the anti-cancer and cardioprotective effects of Tan IIA. Particularly, Tan IIA suppresses the proliferation of malignancies in cancerous cells but stimulates protective mechanisms in normal cardiovascular cells. These findings highlight the importance of investigating molecular signaling pathways in evaluating the therapeutic potential of natural products. Studying about signaling pathways is vital in understanding the therapeutic aspects of Tan IIA and its derivatives as anti-cancer and cardio-protective agents. Further research is necessary to understand these complex mechanisms.

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.

Syringaldehyde Alleviates Cardiac Hypertrophy Induced by Hyperglycemia in H9c2 Cells Through GLP-1 Receptor Signals

Background: Cardiac hypertrophy is a significant complication of diabetes, often triggered by hyperglycemia. Glucagon-like peptide-1 (GLP-1) receptor agonists alleviate cardiac hypertrophy, but their efficacy diminishes under GLP-1 resistance. Syringaldehyde (SA), a natural phenolic compound, may activate GLP-1 receptors and mitigate hypertrophy. This study explores SA's therapeutic potential in hyperglycemia-induced cardiac hypertrophy in H9c2 cardiomyocytes. Methods: H9c2 cells were exposed to high glucose to induce hypertrophy. Cells were treated with varying SA concentrations, and hypertrophic biomarkers were analyzed using ELISA, qPCR, and Western blot. Results: SA reduced cell size and hypertrophic biomarkers in a dose-dependent manner while increasing GLP-1 receptor expression and cAMP levels. These effects were attenuated in GLP-1-resistant cells, highlighting the role of GLP-1 receptor activation. AMPK activation was essential, as its inhibition abolished SA's effects. SA also decreased O-linked N-acetylglucosamine transferase (OGT) expression via AMPK activation, contributing to reduced hypertrophy. Conclusions: SA alleviates hyperglycemia-induced cardiac hypertrophy in H9c2 cells by activating the GLP-1 receptor and AMPK signaling pathway.

Naoxintong capsule accelerates mitophagy in cerebral ischemia-reperfusion injury via TP53/PINK1/PRKN pathway based on network pharmacology analysis and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

The incidence and mortality of cerebrovascular diseases are increasing year by year. Cerebral ischemia-reperfusion injury (CIRI) is common in patients with ischemic stroke. Naoxintong (NXT) is composed of a variety of Chinese medicines and has the ability to treat CIRI.

AIM OF THE STUDY

The aim of this study is to investigate whether NXT regulates mitophagy in CIRI based on network pharmacology analysis and experimental validation.

MATERIALS AND METHODS

Oxygen and glucose deprivation/re-oxygenation (OGD/R, 2/22 h) model of PC12 cells and transient middle cerebral artery occlusion (tMCAO, 2/22 h) model of rats were established. Pharmacodynamic indicators include neurological deficit score, 2,3,5-triphenyte-trazoliumchloride (TTC) staining, hematoxylin-eosin (HE) staining and cell viability. Network pharmacology was used to predict pharmacological mechanisms. Pharmacological mechanism indexes include transmission electron microscopy (TEM), drug affinity responsive target stability (DARTS), cellular thermal shift assay (CETSA), immunohistochemistry (IHC), western blot (WB) and immunofluorescence (IF). Kevetrin (an agonists of p53) and pifithrin-α (an inhibitor of p53) used to detect the key role of p53 in mitophagy of NXT.

RESULTS

NXT (1% serum containing NXT and 110 mg/kg) improved the damage of OGD/R PC12 cells and tMCAO rats, and this protective effect was related to the anti-oxidation and ability to promote mitophagy of NXT. NXT and pifithrin-α increased the expression of promoting-mitophagy targets (PINK1, PRKN and LC3B) and inhibited the expression of inhibiting-mitophagy targets (p52) via restraining p53, and finally accelerated mitophagy caused by CIRI.

CONCLUSION

This study demonstrates that NXT promotes mitophagy in CIRI through restraining p53 and promoting PINK1/PRKN in vivo and in vitro.

Exploring the mechanism of pachymic acid intervention in myocardial ischemia based on network pharmacology and experimental validation

OBJECTIVES

To deeply explore the mechanism of pachymic acid (PA) intervention in myocardial ischemia, providing new ideas and methods for the treatment of myocardial ischemia.

METHODS

Predict the targets of PA for improving myocardial ischemia, and conduct functional enrichment analysis using databases, such as Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Reactome. To verify these findings, PPI network topology analysis and molecular docking were used to screen key targets and main mechanisms of action and further validated through in vitro experiments on the H9C2 cell line.

KEY FINDINGS

PA can significantly alleviate myocardial damage caused by hypoxia/reoxygenation, effectively reversing the abnormalities of oxidative stress indicators such as LDH, MDA, SOD, and ROS. PA may exert its effects through 39 targets, particularly by regulating the downregulation of autophagy-related proteins LC3-II and Beclin-1 expression via MTOR, thereby inhibiting excessive autophagy in cardiomyocytes.

CONCLUSIONS

PA protects myocardial cells during myocardial ischemia through various pathways, particularly by regulating mTOR to inhibit excessive autophagy.

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.

Activation of PPAR-α attenuates myocardial ischemia/reperfusion injury by inhibiting ferroptosis and mitochondrial injury via upregulating 14-3-3η

This study aimed to explore the effects of peroxisome proliferator-activated receptor α (PPAR-α), a known inhibitor of ferroptosis, in Myocardial ischemia/reperfusion injury (MIRI) and its related mechanisms. In vivo and in vitro MIRI models were established. Our results showed that activation of PPAR-α decreased the size of the myocardial infarct, maintained cardiac function, and decreased the serum contents of creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), and Fe2+ in ischemia/reperfusion (I/R)-treated mice. Additionally, the results of H&E staining, DHE staining, TUNEL staining, and transmission electron microscopy demonstrated that activation of PPAR-α inhibited MIRI-induced heart tissue and mitochondrial damage. It was also found that activation of PPAR-α attenuated MIRI-induced ferroptosis as shown by a reduction in malondialdehyde, total iron, and reactive oxygen species (ROS). In vitro experiments showed that intracellular contents of malondialdehyde, total iron, LDH, reactive oxygen species (ROS), lipid ROS, oxidized glutathione disulphide (GSSG), and Fe2+ were reduced by the activation of PPAR-α in H9c2 cells treated with anoxia/reoxygenation (A/R), while the cell viability and GSH were increased after PPAR-α activation. Additionally, changes in protein levels of the ferroptosis marker further confirmed the beneficial effects of PPAR-α activation on MIRI-induced ferroptosis. Moreover, the results of immunofluorescence and dual-luciferase reporter assay revealed that PPAR-α achieved its activity via binding to the 14-3-3η promoter, promoting its expression level. Moreover, the cardioprotective effects of PPAR-α could be canceled by pAd/14-3-3η-shRNA or Compound C11 (14-3-3η inhibitor). In conclusion, our results indicated that ferroptosis plays a key role in aggravating MIRI, and PPAR-α/14-3-3η pathway-mediated ferroptosis and mitochondrial injury might be an effective therapeutic target against MIRI.

Exploring the molecular biology of ischemic cardiomyopathy based on ferroptosis‑related genes

Ischemic cardiomyopathy (ICM) is a serious cardiac disease with a very high mortality rate worldwide, which causes myocardial ischemia and hypoxia as the main damage. Further understanding of the underlying pathological processes of cardiomyocyte injury is key to the development of cardioprotective strategies. Ferroptosis is an iron-dependent form of regulated cell death characterized by the accumulation of lipid hydroperoxides to lethal levels, resulting in oxidative damage to the cell membrane. The current understanding of the role and regulation of ferroptosis in ICM is still limited, especially in the absence of evidence from large-scale transcriptomic data. Through comprehensive bioinformatics analysis of human ICM transcriptome data obtained from the Gene Expression Omnibus database, the present study identified differentially expressed ferroptosis-related genes (DEFRGs) in ICM. Subsequently, their potential biological mechanisms and cross-talk were analyzed, and hub genes were identified by constructing protein-protein interaction networks. Ferroptosis features such as reactive oxygen species generation, changes in ferroptosis marker proteins, iron ion aggregation and lipid oxidation, were identified in the H9c2 anoxic reoxygenation injury model. Finally, the diagnostic ability of Gap junction alpha-1 (GJA1), Solute carrier family 40 member 1 (SLC40A1), Alpha-synuclein (SNCA) were identified through receiver operating characteristic curves and the expression of DEFRGs was verified in an in vitro model. Furthermore, potential drugs (retinoic acid) that could regulate ICM ferroptosis were predicted based on key DEFRGs. The present article presents new insights into the role of ferroptosis in ICM, investigating the regulatory role of ferroptosis in the pathological process of ICM and advocating for ferroptosis as a potential novel therapeutic target for ICM based on evidence from the ICM transcriptome.