SIRT1 is a regulator of autophagy: Implications for the progression and treatment of myocardial ischemia-reperfusion

The role of sirtuins in the regulation of reactive oxygen species in myocardial ischemia/reperfusion injury

Myocardial ischemia/reperfusion (I/R) injury has high morbidity and mortality rates, posing a significant burden on society. There is an urgent need to understand its pathogenesis and develop effective treatments. Reactive oxygen species (ROS) are crucial for the development of myocardial I/R injury, and inhibiting ROS overproduction is one of the most critical ways to delay myocardial I/R injury. Sirtuins are a group of nicotinic adenine dinucleotide ( +)-dependent histone deacetylases whose members can regulate ROS by modulating various biological processes. Numerous studies have shown that Sirtuins play an essential role in the progression of myocardial I/R injury by regulating ROS. This study focuses on the relationship between myocardial I/R injury and ROS, Sirtuins and ROS, discusses the role of Sirtuins in regulating ROS in myocardial I/R, and summarizes the therapeutic modalities aimed at targeting Sirtuins to modulate ROS in myocardial I/R injury, thereby guiding future research endeavors.

The roles and mechanisms of CDGSH iron-sulfur domain 1 in kainic acid-induced mitochondrial iron overload, dysfunction and neuronal damage

Maintaining mitochondrial function plays a crucial role in preventing and treating neurodegenerative diseases. CDGSH iron-sulfur domain 1 (CISD1), a NEET family protein localized on the mitochondrial outer membrane, regulates mitochondrial iron transport. However, the precise mechanism by which CISD1 modulates mitochondrial Fe2 + remains unclear. In this study, we examine the link between aberrant iron metabolism and mitochondrial dysfunction using in vivo and in vitro excitotoxicity models. Our study also clarifies how CISD1 modulates KA-mediated excitotoxic neuronal damage. Overexpression of CISD1 reverses KA-induced mitochondrial iron overload and dysfunction. KA significantly downregulate the mitochondrial protein deacetylase SIRT1. SRT1460 (SIRT1-specific agonist) mitigates mitochondrial iron overload and restore CISD1 expression levels. Altogether, CISD1 protects against excitotoxic injury by mitigating mitochondrial iron overload, thereby providing a potential therapeutic target for neurodegenerative diseases.

Shen-fu Injection Modulates HIF- 1α/BNIP3-Mediated Mitophagy to Alleviate Myocardial Ischemia-Reperfusion Injury

Coronary reperfusion therapy is the most common surgical treatment for myocardial infarction, but it can further induce myocardial ischemia-reperfusion injury (MIRI). Therefore, MIRI following coronary intervention is a challenging clinical issue. This study aims to investigate the involvement of HIF- 1α/BNIP3-mediated mitophagy in the protective effects of Shen-fu Injection (SFI) on MIRI in rats. Key targets and signaling pathways of myocardial MIRI were analyzed using high-throughput transcriptome data from the GSE240842 dataset in the GEO database.To establish the MIRI rat model, the left anterior descending coronary artery was ligated for 30 min, followed by reperfusion for 120 min. Hypoxia/reoxygenation (H/R) in neonatal rat primary cardiomyocytes was induced by oxygen-glucose deprivation for 4 h, followed by reoxygenation for 2 h. Two hours after reperfusion, assessments included myocardial infarction area, CK-MB, CTnI, HE staining, TUNEL, mitochondrial ultrastructure and autophagosomes, HIF- 1α, BNIP3, LC3B-II, LC3B-I protein expression, immunofluorescence, and qRT-PCR. Cardiac function was also evaluated using M-mode ultrasound 2 h after reperfusion. In cardiomyocytes, CCK- 8, EdU cell proliferation levels, scratch assay, mitochondrial membrane potential, ROS levels, cardiomyocyte apoptosis, protein expression levels, and immunofluorescence were assessed 2 h after reoxygenation. Our results indicate that HIF- 1α and BNIP3 are key targets in MIRI. SFI upregulates HIF- 1α expression, promoting moderate mitophagy. This process clears excessively damaged mitochondria, reduces cardiomyocyte apoptosis, and decreases myocardial injury. Additionally, SFI reduces autophagosome accumulation, lowers ROS production, and stabilizes membrane potential. Consequently, the area of myocardial infarction is reduced, and cardiac function is improved. SFI activates the HIF- 1α/BNIP3 pathway to mediate moderate mitophagy, effectively reducing cardiomyocyte apoptosis and alleviating myocardial ischemia-reperfusion injury, thereby protecting cardiomyocytes.

Protection of Framework Nucleic Acid Complexes via Regulating Ferroptosis on Myocardial Ischemia-Reperfusion Injury

The pathogenesis of myocardial ischemia-reperfusion injury (MIRI) is a complex process involving multiple pathophysiological mechanisms, including mitochondrial dysfunction, oxidative stress, and ferroptosis. Therefore, MIRI continues to pose a significant obstacle in cardiovascular therapy. Curcumin (Cur), a natural polyphenolic compound with potent antioxidant and antiferroptosis properties, has therapeutic potential but is poorly soluble, unstable, and has low bioavailability. To address these issues, a tetrahedral framework nucleic acid (tFNA) piggybacked Cur (tFNA-Cur) drug delivery system was designed to achieve efficient drug delivery and synergistically amplify the therapeutic effect by utilizing the programmable nanostructures, excellent safety profile, high biocompatibility, and intrinsic antioxidant activity of tFNA. In vitro studies demonstrated that tFNA-Cur could effectively mitigate oxidative stress-induced injury in H9C2 cardiomyocytes by restoring the redox balance and inhibiting ferroptosis. In a rat MIRI model, tFNA-Cur demonstrated significant efficacy, including reduced infarct size, decreased Fe2+ accumulation, and inhibited MDA production, a marker of lipid peroxidation. At the molecular level, tFNA-Cur enhanced the production of antioxidant proteins (GPX4, HO-1) by modulating the KEAP1-Nrf2 signaling axis, while inhibiting the overproduction of mitochondrial reactive oxygen species (ROS). This achieved a synergistic multitargeted and effective suppression of cardiomyocyte ferroptosis during the MIRI process. This study emphasizes the value of tFNA-Cur as a promising nanotherapeutic strategy in treating MIRI. It provides new ideas and research directions for combining nucleic acid nanomaterials with natural compounds to treat MIRI.

Therapeutic applications of exercise in neurodegenerative diseases: focusing on the mechanism of SIRT1

Neurodegenerative diseases comprise a group of central nervous system disorders marked by progressive neuronal degeneration and dysfunction. Their pathogenesis is multifactorial, involving oxidative stress, mitochondrial dysfunction, excitotoxicity, and neuroinflammation. Recent research has highlighted the potential of exercise as a non-pharmacological intervention for both the prevention and treatment of these disorders. In particular, exercise has received growing attention for its capacity to upregulate the expression and activity of SIRT1, a critical mediator of neuroprotection via downstream signaling pathways. SIRT1, a key member of the Sirtuin family, is a nicotinamide adenine dinucleotide (NAD +)-dependent class III histone deacetylase. It plays an essential role in regulating cellular metabolism, energy homeostasis, gene expression, and cellular longevity. In the context of neurodegenerative diseases, SIRT1 confers neuroprotection by modulating multiple signaling cascades through deacetylation, suppressing neuronal apoptosis, and promoting neural repair and regeneration. Exercise enhances SIRT1 expression and activity by increasing NAD + synthesis and utilization, improving intracellular redox balance, alleviating oxidative stress-induced inhibition of SIRT1, and thereby promoting its activation. Moreover, exercise may indirectly modulate SIRT1 function by influencing interacting molecular networks. This review summarizes recent advances in the therapeutic application of exercise for neurodegenerative diseases, with a focus on SIRT1 as a central mechanism. It examines how exercise mediates neuroprotection through the regulation of SIRT1 and its associated molecular mechanisms and signaling pathways. Finally, the paper discusses the potential applications and challenges of integrating exercise and SIRT1-targeted strategies in the management of neurodegenerative diseases, offering novel perspectives for the development of innovative treatments and improvements in patients' quality of life.

An integrated analysis revealing that Sirt1-mediated decreased autophagy in the hippocampus of animal models of depression

BACKGROUND

Depression is a complex and prevalent mental disorder. Numerous studies have reported there were significant metabolomic and proteomic changes in hippocampus of depressed patients. However, few researches have systematically integrated these two omics data to identify key molecular mechanisms underlying depression.

METHODS

Based on the data of Protein and Metabolite Network of Depression Database (ProMENDA), we integrate the significantly altered metabolites and proteins of hippocampus in animal models of depression. Pathway analysis was performed using IPA software to explore biological functional disturbance underlying these molecules. Finally, animal model construction, molecular biology experiments, and lentiviral transfection in vitro for gene knockout were performed to verify potential pathways.

RESULTS

A total of 682 altered metabolites and 2300 altered proteins were retrieved. Pathway enrichment analysis identified 394 significantly enriched pathways, with the sirtuin signaling mediated autophagy being of particular interest. Further biological validations revealed the decrease of Sirt1, the autophagy-related genes, and autophagy markers in hippocampus of both mouse and Macaca fascicularis models of depression. Lastly, Sirt1 knockdown in primary neurons inhibited autophagy.

CONCLUSION

This study expanded our understanding of multi-omics alterations in the hippocampus of depression by revealing that Sirt1 may mediate neuronal autophagy in the hippocampus of animal models of depression, which could further contribute to the pathophysiology of depression.

Protective Effects of Rat Bone Marrow Mesenchymal Stem Cells-Derived Fusogenic Plasma Membrane Vesicles Containing VSVG Protein Mediated Mitochondrial Transfer on Myocardial Injury In Vitro

Overexpression of spike glycoprotein G of vesicular stomatitis virus (VSVG) can induce the release of fusogenic plasma membrane vesicles (fPMVs), which can transport cytoplasmic, nuclear, and surface proteins directly to target cells. This study aimed to investigate the roles of rat bone marrow mesenchymal stem cells (rBMSCs)-derived fPMVs containing VSVG protein in myocardial injury and their related mechanisms. The plasmids of pLP-VSVG were used to transfect rBMSCs, and then fPMVs were obtained by mechanical extrusion. After that, H9c2 cells were first treated with hypoxia reoxygenation (HR) to establish a cardiomyocyte injury model, and then were treated with fPMVs to evaluate the rescue of rBMSCs-derived fPMVs on HR-induced cardiomyocyte injury. FPMVs containing VSVG protein were successfully prepared from rBMSCs with VSVG overexpression. Compared with control fPMVs, ACTB, HDAC1, VSVG, CD81, MTCO1, and TOMM20 were significantly up-regulated (p < 0.05), while eEF2 was significantly down-regulated (p < 0.05) in the fPMVs containing VSVG protein. Additionally, it was obvious fPMVs could carry mitochondria into H9c2 cells, and HR treatment significantly inhibited viability and induced apoptosis of H9c2 cells, as well as significantly increased the contents of TNF-α and IL-1β, and ROS levels both in cells and cellular mitochondria, while evidently reducing the levels of ATP, MRCC IV, and MT-ND1 (p < 0.05). However, fPVMs could remarkably reverse the changes in these indexes caused by HR (p < 0.05). RBMSCs-derived fPMVs containing VSVG protein may have protective effects on myocardial injury by mediating mitochondrial transfer and regulating mitochondrial functions.

The NR3C2-SIRT1 signaling axis promotes autophagy and inhibits epithelial mesenchymal transition in colorectal cancer

Colorectal cancer (CRC) is one of the most aggressive and lethal cancers with a complex pathogenesis, there is an urgent need to find new drug therapeutic targets. This study highlights the important role of the NR3C2-SIRT1 signaling axis in the metastasis mechanism of CRC. Our findings revealed that the expression of NR3C2 in CRC tissues was lower than that in adjacent non-cancerous tissues, and was negatively correlated with N stage by bioanalysis, IHC, western blot and qRT-PCR. NR3C2 overexpression / knockdown can significantly inhibit / promote the migration and invasion of CRC cells, at the same time inhibit / promote EMT. Mechanically, the regulatory molecule SIRT1 was identified by RNA-seq, bioinformatics analysis, western blot and ChIP. SIRT1 was also involved in the metastasis process of CRC, and NR3C2 was found to regulate the expression of LC3B and SQSTM1/p62 in a SIRT1-dependent manner. Therefore, NR3C2 forms a signaling axis with SIRT1, which can directly promote autophagy and inhibit EMT process in vivo and in vitro. Collectively, our findings suggest that NR3C2 - SIRT1 signal axis promote autophagy and inhibit EMT, ultimately inhibits lung metastasis of CRC.

Protein modifications in hepatic ischemia-reperfusion injury: molecular mechanisms and targeted therapy

Ischemia-reperfusion injury refers to the damage that occurs when blood supply is restored to organs or tissues after a period of ischemia. This phenomenon is commonly observed in clinical contexts such as organ transplantation and cardiac arrest resuscitation. Among these, hepatic ischemia-reperfusion injury is a prevalent complication in liver transplantation, significantly impacting the functional recovery of the transplanted liver and potentially leading to primary graft dysfunction. With the growing demand for organ transplants and the limited availability of donor organs, effectively addressing hepatic ischemia-reperfusion injury is essential for enhancing transplantation success rates, minimizing complications, and improving graft survival. The pathogenesis of hepatic ischemia-reperfusion injury is multifaceted, involving factors such as oxidative stress and inflammatory responses. This article focuses on the role of protein post-translational modifications in hepatic ischemia-reperfusion injury, including phosphorylation, ubiquitination, acetylation, ADP-ribosylation, SUMOylation, crotonylation, palmitoylation, and S-nitrosylation. Initially, we examined the historical discovery of these protein post-translational modifications and subsequently investigated their impact on cellular signal transduction, enzymatic activity, protein stability, and protein-protein interactions. The emphasis of this study is on the pivotal role of protein post-translational modifications in the progression of hepatic ischemia-reperfusion injury and their potential as therapeutic targets. This study aims to conduct a comprehensive analysis of recent advancements in research on protein modifications in hepatic ischemia-reperfusion injury, investigate the underlying molecular mechanisms, and explore future research trajectories. Additionally, future research directions are proposed, including the exploration of interactions between various protein modifications, the identification of specific modification sites, and the development of drugs targeting these modifications. These efforts aim to deepen our understanding of protein post-translational modifications in hepatic ischemia-reperfusion injury and pave the way for innovative therapeutic interventions.

The Impact of Opioids on Epigenetic Modulation in Myocardial Ischemia and Reperfusion Injury: Focus on Non-coding RNAs

Myocardial ischemia-reperfusion injury (IRI) is a major issue in cardiovascular medicine, marked by tissue damage from the restoration of blood flow after ischemia. Opioids, known for their pain-relieving properties, have emerged as potential cardioprotective agents in IRI. Recent research suggests opioids influence epigenetic mechanisms-such as histone modifications and non-coding RNAs (ncRNAs)-which are essential for regulating gene expression and cellular responses during myocardial IRI. This review delves into how opioids like remifentanil affect histone modifications, DNA methylation, and ncRNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Remifentanil postconditioning (RPC) reduces apoptosis in cardiomyocytes through histone deacetylation, specifically downregulating histone deacetylase 3 (HDAC3). Similarly, opioids impact miRNAs such as miR- 206 - 3p and miR- 320 - 3p, and lncRNAs like TINCR and UCA1, which influence apoptosis, inflammation, and oxidative stress. Understanding these interactions highlights the potential for opioid-based therapies in mitigating IRI-induced myocardial damage.

Research progress on the mechanism of curcumin anti-oxidative stress based on signaling pathway

Oxidative stress refers to an imbalance between oxidative capacity and antioxidant capacity, leading to oxidative damage to proteins, lipids, and DNA, which can result in cell senescence or death. It is closely associated with the occurrence and development of various diseases, including cardiovascular diseases, nephropathy, malignant tumors, neurodegenerative diseases, hypertension, diabetes, and inflammatory diseases. Curcumin is a natural polyphenol compound of β-diketone, which has a wide range of pharmacological activities such as anti-inflammatory, antibacterial, anti-oxidative stress, anti-tumor, anti-fibrosis, and hypolipidemic, demonstrating broad research and development value. It has a wide range of biological targets and can bind to various endogenous biomolecules. Additionally, it maintains the redox balance primarily by scavenging ROS, enhancing the activity of antioxidant enzymes, inhibiting lipid peroxidation, and chelating metal ions. This paper systematically describes the antioxidative stress mechanisms of curcumin from the perspective of signaling pathways, focusing on the Keap1-Nrf2/ARE, NF-κB, NOX, MAPK and other pathways. The study also discusses potential pathway targets and the complex crosstalk among these pathways, aiming to provide insights for further research on curcumin's antioxidant mechanisms and its clinical applications.

The role of autophagy in fibrosis: Mechanisms, progression and therapeutic potential (Review)

Various forms of tissue damage can lead to fibrosis, an abnormal reparative reaction. In the industrialized countries, 45% of deaths are attributable to fibrotic disorders. Autophagy is a highly preserved process. Lysosomes break down organelles and cytoplasmic components during autophagy. The cytoplasm is cleared of pathogens and dysfunctional organelles, and its constituent components are recycled. With the growing body of research on autophagy, it is becoming clear that autophagy and its associated mechanisms may have a role in the development of numerous fibrotic disorders. However, a comprehensive understanding of autophagy in fibrosis is still lacking and the progression of fibrotic disease has not yet been thoroughly investigated in relation to autophagy‑associated processes. The present review focused on the latest findings and most comprehensive understanding of macrophage autophagy, endoplasmic reticulum stress‑mediated autophagy and autophagy‑mediated endothelial‑to‑mesenchymal transition in the initiation, progression and treatment of fibrosis. The article also discusses treatment strategies for fibrotic diseases and highlights recent developments in autophagy‑targeted therapies.

Involvement of Oxidative Stress and Antioxidants in Modification of Cardiac Dysfunction Due to Ischemia-Reperfusion Injury

Delayed reperfusion of the ischemic heart (I/R) is known to impair the recovery of cardiac function and produce a wide variety of myocardial defects, including ultrastructural damage, metabolic alterations, subcellular Ca2+-handling abnormalities, activation of proteases, and changes in cardiac gene expression. Although I/R injury has been reported to induce the formation of reactive oxygen species (ROS), inflammation, and intracellular Ca2+ overload, the generation of oxidative stress is considered to play a critical role in the development of cardiac dysfunction. Increases in the production of superoxide, hydroxyl radicals, and oxidants, such as hydrogen peroxide and hypochlorous acid, occur in hearts subjected to I/R injury. In fact, mitochondria are a major source of the excessive production of ROS in I/R hearts due to impairment in the electron transport system as well as activation of xanthine oxidase and NADPH oxidase. Nitric oxide synthase, mainly present in the endothelium, is also activated due to I/R injury, leading to the production of nitric oxide, which, upon combination with superoxide radicals, generates nitrosative stress. Alterations in cardiac function, sarcolemma, sarcoplasmic reticulum Ca2+-handling activities, mitochondrial oxidative phosphorylation, and protease activation due to I/R injury are simulated upon exposing the heart to the oxyradical-generating system (xanthine plus xanthine oxidase) or H2O2. On the other hand, the activation of endogenous antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, and the concentration of a transcription factor (Nrf2), which modulates the expression of various endogenous antioxidants, is depressed due to I/R injury in hearts. Furthermore, pretreatment of hearts with antioxidants such as catalase plus superoxide dismutase, N-acetylcysteine, and mercaptopropionylglycerine has been observed to attenuate I/R-induced subcellular Ca2+ handling and changes in Ca2+-regulatory activities; additionally, it has been found to depress protease activation and improve the recovery of cardiac function. These observations indicate that oxidative stress is intimately involved in the pathological effects of I/R injury and different antioxidants attenuate I/R-induced subcellular alterations and improve the recovery of cardiac function. Thus, we are faced with the task of developing safe and effective antioxidants as well as agents for upregulating the expression of endogenous antioxidants for the therapy of I/R injury.

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.

Role of sirtuin 1 in depression‑induced coronary heart disease: Molecular pathways and therapeutic potential (Review)

Depression and coronary heart disease (CHD) are two interconnected diseases that profoundly impact global health. Depression is both a complex psychiatric disorder and an established risk factor for CHD. Sirtuin 1 (SIRT1) is an enzyme that requires the cofactor nicotinamide adenine dinucleotide (NAD+) to perform its deacetylation function, and its involvement is crucial in reducing cardiovascular risks that are associated with depression. SIRT1 exerts its cardioprotective effects via modulating oxidative stress, inflammation and metabolic processes, all of which are central to the pathogenesis of CHD in individuals with depression. Through influencing these pathways, SIRT1 helps to reduce endothelial dysfunction, prevent the formation of atherosclerotic plaques and stabilize existing plaques, thereby decreasing the overall risk of CHD. The present review underscores the important role of SIRT1 in serving as a therapeutic intervention molecule for tackling cardiovascular complications stemming from depression. Furthermore, it highlights the need for further studies to clarify how SIRT1 influences both depression and CHD at the molecular level. The ultimate goal of this research will be to translate these findings into practical clinical intervention strategies.

Cardioprotective strategies in myocardial ischemia-reperfusion injury: Implications for improving clinical translation

Ischemic heart disease is the most common cause of death and disability globally which is caused by reduced or complete cessation of blood flow to a portion of the myocardium. One of its clinical manifestations is myocardial infarction, which is commonly treated by restoring of blood flow through reperfusion therapies. However, serious ischemia-reperfusion injury (IRI) can occur, significantly undermining clinical outcomes, for which there is currently no effective therapy. This review revisits several potential pharmacological IRI intervention strategies that have entered preclinical or clinical research phases. Here, we discuss what we have learned through translational failures over the years, and propose possible ways to enhance translation efficiency.

Harnessing the FOXO-SIRT1 axis: insights into cellular stress, metabolism, and aging

Aging and metabolic disorders share intricate molecular pathways, with the Forkhead box O (FOXO)- Sirtuin 1 (SIRT1) axis emerging as a pivotal regulator of cellular stress adaptation, metabolic homeostasis, and longevity. This axis integrates nutrient signaling with oxidative stress defence, modulating glucose and lipid metabolism, mitochondrial function, and autophagy to maintain cellular stability. FOXO transcription factors, regulated by SIRT1 deacetylation, enhance antioxidant defence mechanisms, activating genes such as superoxide dismutase (SOD) and catalase, thereby counteracting oxidative stress and metabolic dysregulation. Recent evidence highlights the dynamic role of reactive oxygen species (ROS) as secondary messengers in redox signaling, influencing FOXO-SIRT1 activity in metabolic adaptation. Additionally, key redox-sensitive regulators such as nuclear factor erythroid 2-related factor 2 (Nrf2) and Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) interact with this pathway, orchestrating mitochondrial biogenesis and adaptive stress responses. Pharmacological interventions, including alpha-lipoic acid (ALA), resveratrol, curcumin and NAD+ precursors, exhibit therapeutic potential by enhancing insulin sensitivity, reducing oxidative burden, and restoring metabolic balance. This review synthesizes current advancements in FOXO-SIRT1 regulation, its emerging role in redox homeostasis, and its therapeutic relevance, offering insights into future strategies for combating metabolic dysfunction and aging-related diseases.

Melatonin ameliorates inflammation and improves outcomes of ischemia/reperfusion injury in patients undergoing coronary artery bypass grafting surgery: a randomized placebo-controlled study

To investigate the protective role of high dose melatonin concerning myocardial I/R injury and inflammation in patients undergoing on-pump coronary artery bypass grafting (CABG) surgery by evaluating IR/inflammatory biomarkers and clinical outcomes. This was a prospective; randomized; single-blinded placebo-controlled study conducted at cardio-thoracic surgery department of the Academy of the Cardiovascular and Thoracic Surgery, Ain Shams University. Eligible patients were randomly allocated to; melatonin-treated group (MTG) or placebo-treated group (PTG). The MTG (n = 17) received 60 mg/day melatonin capsules daily starting 5 days before surgery in addition to the standard of care. PTG (n = 17) received placebo also 5 days before surgery plus standard of care. The levels of nuclear factor kappa beta (NF-κb) (primary outcome), tumor necrosis factor (TNF-α), cardiac troponins I, and IL-6 levels were all assessed for both groups at five time points: baseline before melatonin or placebo administration (T0), before cross-clamp application(T1), 5 min after cross-clamp removal(T2), 6 h after cross-clamp removal(T3) and 24 h after cross-clamp removal(T4). Blood pressure was assessed at baseline, pre-operative and 24-hours post-operative. The Quality of recovery-40 score (QOR-40) was assessed for both groups on day 4 after surgery. TNF-α levels decreased in the MTG at T1(p = 0.034) versus PTG. At T2(p = 0.005), and T3(p = 0.04), TNF-α significantly increased in PTG versus MTG. Troponins significantly increased in PTG at T3 (p = 0.04) versus MTG. NF-κB levels declined at T1 (p = 0.013) and T2 (p = 0.0001) in MTG compared to PTG. IL-6 significantly increased in PTG versus MTG at T3 (p = 0.04). The QOR-40 score significantly decreased in MTG versus PTG. MTG had statistically significant decrease in DBP compared to the placebo group (p = 0.024). MTG had a statistically significant shorter intubation time than did the placebo group (p = 0.03). Melatonin 60 mg was well-tolerated without any reported side effects. Our findings suggested that melatonin could ameliorate myocardial I/R injury after on-pump CABG and that this outcome was essentially correlated to its antiapoptotic and anti-inflammatory effects. Trial registration: ClinicalTrials.gov registration number NCT05552586, 9/2022.

A comprehensive review on the plant sources, pharmacological activities and pharmacokinetic characteristics of Syringaresinol

Syringaresinol, a phytochemical constituent belonging to lignan, is formed from two sinapyl alcohol units linked via a β-β linkage, which can be found in a wide variety of cereals and medicinal plants. Medical researches revealed that Syringaresinol possesses a broad spectrum of biological activities, including anti-inflammatory, anti-oxidation, anticancer, antibacterial, antiviral, neuroprotection, and vasodilation effects. These pharmacological properties lay the foundation for its use in treating various diseases such as inflammatory diseases, neurodegenerative disorders, diabetes and its complication, skin disorders, cancer, cardiovascular, and cerebrovascular diseases. As the demand for natural therapeutics increases, Syringaresinol has garnered significant attention for its pharmacological properties. Despite the extensive literature that highlights the various biological activities of this molecule, the underlying mechanisms and the interrelationships between these activities are rarely addressed from a comprehensive perspective. Moreover, no thorough comprehensive summary and evaluation of Syringaresinol has been conducted to offer recommendations for potential future clinical trials and therapeutic applications of this bioactive compound. Thus, a comprehensive review on Syringaresinol is essential to advance scientific understanding, assess its therapeutic applications, ensure safety, and guide future research efforts. This will ultimately contribute to its potential integration into clinical practice and public health. This study aims to provide a comprehensive overview of Syringaresinol on its sources and biological activities to provide insights into its therapeutic potential, and to provide a basis for high-quality studies to determine the clinical efficacy of this compound. Additionally, we explored the pharmacokinetics, toxicology, and drug development aspects of Syringaresinol to guide future research efforts. The review also discussed the limitations of current research on Syringaresinol and put forward some new perspectives and challenges, which laid a solid foundation for further study on clinical application and new drug development of Syringaresinol in the future.

Salvianolic acid B alleviated myocardial ischemia-reperfusion injury via modulating SIRT3-mediated crosstalk between mitochondrial ROS and NLRP3

BACKGROUND

Mitochondrial ROS (mtROS) accumulation and NLRP3 inflammasome activation are critical in the pathogenesis of myocardial ischemia-reperfusion injury (MIRI). However, their upstream regulatory mechanisms and interaction remain inadequately understood.

PURPOSE

The study aims to investigate the therapeutic effect of Salvianolic acid B (Sal B) on MIRI and elucidate its potential molecular mechanism, mainly focusing on the role of SIRT3.

METHODS

SIRT3 was knocked down (SIRT3KD) and overexpressed (SIRT3OE) using small interfering RNA and plasmid, respectively. The role of SIRT3 in the cardioprotective effect of Sal B was explored using MIRI rat models and H9c2 cell hypoxia/reoxygenation (H/R) models. SIRT3, NLRP3 inflammasome proteins, and MnSOD expression were analyzed by Western blot and immunofluorescence staining. MtROS levels were assessed with mitochondrial superoxide indicators (MitoSOX™ Red). ELISA was utilized to measure the levels of LDH, CK-MB, cTnT, and markers of inflammation and oxidative stress. The interaction between SIRT3 and Sal B was studied through biolayer interferometry, cellular thermal shift assay and molecular docking.

RESULTS

Our findings revealed significantly decreased SIRT3 level, enhanced MnSOD acetylation, and activated NLRP3 inflammasome in myocardium after MIRI and H9c2 cardiomyocytes exposed to H/R conditions. SIRT3KD promoted MnSOD acetylation and NLRP3 expression, aggravating mtROS accumulation and inflammation. Conversely, SIRT3OE significantly inhibited MnSOD acetylation and NLRP3 inflammasome activation. In vitro studies confirmed the crosstalk between mtROS and NLRP3, demonstrating that mtROS scavenger inhibited NLRP3 inflammasome activation induced by H/R and SIRT3KD, and the NLRP3 inhibitor suppressed MnSOD acetylation in H/R and SIRT3KD cardiomyocytes. Interestingly, Sal B was found to bind and upregulate SIRT3, reduce the expression of Acy-MnSOD, NLRP3, ASC, Caspase-1, and GSDMD, inhibit oxidative stress and inflammatory response, decrease myocardial infarct size and ST-segment elevation, and restore myocardial morphology. However, the protective effect of Sal B against MIRI was nullified by a specific SIRT3 inhibitor.

CONCLUSION

This study unveils that the SIRT3-mediated interplay between mtROS and the NLRP3 inflammasome is pivotal in the pathogenesis of MIRI. Furthermore, it highlights Sal B as a novel therapeutic agent that alleviates MIRI by targeting SIRT3, offering new insights into MIRI treatment.

CHK1 attenuates cardiac dysfunction via suppressing SIRT1-ubiquitination

BACKGROUND

Mitochondrial dysfunction is linked to myocardial ischemia-reperfusion (I/R) injury. Checkpoint kinase 1 (CHK1) could facilitate cardiomyocyte proliferation, however, its role on mitochondrial function in I/R injury remains unknown.

METHODS

To investigate the role of CHK1 on mitochondrial function following I/R injury, cardiomyocyte-specific knockout/overexpression mouse models were generated. Adult mouse cardiomyocytes (AMCMs) were isolated for in vitro study. Mass spectrometry-proteomics analysis and protein co-immunoprecipitation assays were conducted to dissect the molecular mechanism.

RESULTS

CHK1 was downregulated in myocardium post I/R and AMCMs post oxygen-glucose deprivation/re‑oxygenation (OGD/R). In vivo, CHK1 overexpression protected against I/R induced cardiac dysfunction, while heterogenous CHK1 knockout exacerbated cardiomyopathy. In vitro, CHK1 inhibited OGD/R-induced cardiomyocyte apoptosis and bolstered cardiomyocyte survival. Mechanistically, CHK1 attenuated oxidative stress and preserved mitochondrial metabolism in cardiomyocytes under I/R. Moreover, disrupted mitochondrial homeostasis in I/R myocardium was restored by CHK1 through the promotion of mitochondrial biogenesis and mitophagy. Through mass spectrometry analysis following co-immunoprecipitation, SIRT1 was identified as a direct target of CHK1. The 266-390 domain of CHK1 interacted with the 160-583 domain of SIRT1. Importantly, CHK1 phosphorylated SIRT1 at Thr530 residue, thereby inhibiting SMURF2-mediated degradation of SIRT1. The role of CHK1 in maintaining mitochondrial dynamics control and myocardial protection is abolished by SIRT1 inhibition, while inactivated mutation of SIRT1 Thr530 fails to reverse the impaired mitochondrial dynamics following CHK1 knockdown. CHK1 Δ390 amino acids (aa) mutant functioned similarly to full-length CHK1 in scavenging ROS and maintaining mitochondrial dynamics. Consistently, cardiac-specific SIRT1 knockdown attenuated the protective role of CHK1 in I/R injury.

CONCLUSIONS

Our findings revealed that CHK1 mitigates I/R injury and restores mitochondrial dynamics in cardiomyocytes through a SIRT1-dependent mechanism.

Epigenetic modifications and emerging therapeutic targets in cardiovascular aging and diseases

The complex mechanisms underlying the development of cardiovascular diseases remain not fully elucidated. Epigenetics, which modulates gene expression without DNA sequence changes, is shedding light on these mechanisms and their heritable effects. This review focus on epigenetic regulation in cardiovascular aging and diseases, detailing specific epigenetic enzymes such as DNA methyltransferases (DNMTs), histone acetyltransferases (HATs), and histone deacetylases (HDACs), which serve as writers or erasers that modify the epigenetic landscape. We also discuss the readers of these modifications, such as the 5-methylcytosine binding domain proteins, and the erasers ten-eleven translocation (TET) proteins. The emerging role of RNA methylation, particularly N6-methyladenosine (m6A), in cardiovascular pathogenesis is also discussed. We summarize potential therapeutic targets, such as key enzymes and their inhibitors, including DNMT inhibitors like 5-azacytidine and decitabine, HDAC inhibitors like belinostat and givinotide, some of which have been approved by the FDA for various malignancies, suggesting their potential in treating cardiovascular diseases. Furthermore, we highlight the role of novel histone modifications and their associated enzymes, which are emerging as potential therapeutic targets in cardiovascular diseases. Thus, by incorporating the recent studies involving patients with cardiovascular aging and diseases, we aim to provide a more detailed and updated review that reflects the advancements in the field of epigenetic modification in cardiovascular diseases.

Acetylation of FOXO1 is involved in cadmium-induced rat kidney injury via mediating autophagosome-lysosome fusion blockade and autophagy inhibition

Cadmium (Cd), a potentially toxic elements, has the potential to cause harm to the kidneys. Studies has demonstrated that autophagosome-lysosome fusion blockade and consequent autophagy inhibition is related to Cd-induced kidney injury. Studies indicate that acetylation of forkhead box protein O1 (FOXO1) as a transcriptional factor of lysosomal and autophagy genes, but its roles in Cd-exposed kidney tissues remains unclear till now. Therefore, the present study was conducted to elucidate this issue. Data found that Cd enhances the acetylation level of FOXO1 and inhibits the expression level of silent information regulator 1 (Sirt1, deacetylase of FOXO1). Pharmacological activation of Sirt1 (SRT2104 treatment) decreases Cd-increased acetylation level of FOXO1, enhances Cd-inhibited transcription level of Ras-related protein 7 (Rab7), restores Cd-blocked fusion of autophagosome and lysosome, and alleviates Cd-induced autophagy inhibition. Moreover, data corroborated that inhibiting the acetylation level of FOXO1 is conductive to mitigating Cd-induced kidney injury. Collectively, these results demonstrate that acetylation of FOXO1 mediates the autophagosome-lysosome fusion blockade and autophagy inhibition during Cd-induced kidney injury, while regulating the acetylation level of FOXO1 may be a potential mechanism of treating nephrotoxicity after Cd exposure.

Dual-edged role of SIRT1 in energy metabolism and cardiovascular disease

Regulation of energy metabolism is pivotal in the development of cardiovascular diseases. Dysregulation in mitochondrial fatty acid oxidation has been linked to cardiac lipid accumulation and diabetic cardiomyopathy. Sirtuin 1 (SIRT1) is a deacetylase that regulates the acetylation of various proteins involved in mitochondrial energy metabolism. SIRT1 mediates energy metabolism by directly and indirectly affecting multiple aspects of mitochondrial processes, such as mitochondrial biogenesis. SIRT1 interacts with essential mitochondrial energy regulators such as peroxisome proliferator-activated receptor-α (PPARα), PPARγ coactivator-1α, estrogen-related receptor-α, and their downstream targets. Apart from that, SIRT1 regulates additional proteins, including forkhead box protein O1 and AMP-activated protein kinase in cardiac disease. Interestingly, studies have also shown that the expression of SIRT1 plays a dual-edged role in energy metabolism. Depending on the physiological state, SIRT1 expression can be detrimental or protective. This review focuses on the molecular pathways through which SIRT1 regulates energy metabolism in cardiovascular diseases. We will review SIRT1 and discuss its role in cardiac energy metabolism and its benefits and detrimental effects in heart disease.

The PINK1/Parkin signaling pathway-mediated mitophagy: a forgotten protagonist in myocardial ischemia/reperfusion injury

Myocardial ischemia causes extensive damage, further exacerbated by reperfusion, a phenomenon called myocardial ischemia/reperfusion injury (MIRI). Nowadays, the pathological mechanisms of MIRI have received extensive attention. Oxidative stress, multiple programmed cell deaths, inflammation and others are all essential pathological mechanisms contributing to MIRI. Mitochondria are the energy supply centers of cells. Numerous studies have found that abnormal mitochondrial function is an essential "culprit" of MIRI, and mitophagy mediated by the phosphatase and tensin homolog (PTEN)-induced kinase 1 (PINK1)/Parkin signaling pathway is an integral part of maintaining mitochondrial function. Therefore, exploring the association between the PINK1/Parkin signaling pathway-mediated mitophagy and MIRI is crucial. This review will mainly summarize the crucial role of the PINK1/Parkin signaling pathway-mediated mitophagy in MIR-induced several pathological mechanisms and various potential interventions that affect the PINK1/Parkin signaling pathway-mediated mitophagy, thus ameliorating MIRI.

Myocardial ischemia-reperfusion injury upregulates nucleostemin expression via HIF-1α and c-Jun pathways and alleviates apoptosis by promoting autophagy

Myocardial ischemia-reperfusion (I/R) injury, often arising from interventional therapy for acute myocardial infarction, leads to irreversible myocardial cell death. While previous studies indicate that nucleostemin (NS) is induced by myocardial I/R injury and mitigates myocardial cell apoptosis, the underlying mechanisms are poorly understood. Here, our study reveals that NS upregulation is critical for preventing cardiomyocyte death following myocardial I/R injury. Elevated NS protein levels were observed in myocardial I/R injury mouse and rat models, as well as Hypoxia/reoxygenation (H/R) cardiac cell lines (H9C2 cells). We identified binding sites for c-Jun and HIF-1α in the NS promoter region. Inhibition of JNK and HIF-1α led to a significant decrease in NS transcription and protein expression. Furthermore, inhibition of autophagy and NS expression promoted myocardial cell apoptosis in H/R. Notably, the cell model showed reduced LC3I transformation to LC3II, downregulated Beclin1, upregulated p62, and altered expression of autophagy-related proteins upon NS interference in H/R cells. These findings suggest that NS expression, driven by c-Jun and HIF-1α pathways, facilitates autophagy, providing protection against both myocardial I/R injury and H/R-induced cardiomyocyte apoptosis.

Sirtuin 1/sirtuin 3 are robust lysine delactylases and sirtuin 1-mediated delactylation regulates glycolysis

Lysine lactylation (Kla), an epigenetic mark triggered by lactate during glycolysis, including the Warburg effect, bridges metabolism and gene regulation. Enzymes such as p300 and HDAC1/3 have been pivotal in deciphering the regulatory dynamics of Kla, though questions about additional regulatory enzymes, their specific Kla substrates, and the underlying functional mechanisms persist. Here, we identify SIRT1 and SIRT3 as key "erasers" of Kla, shedding light on their selective regulation of both histone and non-histone proteins. Proteomic analysis in SIRT1/SIRT3 knockout HepG2 cells reveals distinct substrate specificities toward Kla, highlighting their unique roles in cellular signaling. Notably, we highlight the role of specific Kla modifications, such as those on the M2 splice isoform of pyruvate kinase (PKM2), in modulating metabolic pathways and cell proliferation, thereby expanding Kla's recognized functions beyond epigenetics. Therefore, this study deepens our understanding of Kla's functional mechanisms and broadens its biological significance.

Epigenetic regulation of diverse regulated cell death modalities in cardiovascular disease: Insights into necroptosis, pyroptosis, ferroptosis, and cuproptosis

Cell death constitutes a critical component of the pathophysiology of cardiovascular diseases. A growing array of non-apoptotic forms of regulated cell death (RCD)-such as necroptosis, ferroptosis, pyroptosis, and cuproptosis-has been identified and is intimately linked to various cardiovascular conditions. These forms of RCD are governed by genetically programmed mechanisms within the cell, with epigenetic modifications being a common and crucial regulatory method. Such modifications include DNA methylation, RNA methylation, histone methylation, histone acetylation, and non-coding RNAs. This review recaps the roles of DNA methylation, RNA methylation, histone modifications, and non-coding RNAs in cardiovascular diseases, as well as the mechanisms by which epigenetic modifications regulate key proteins involved in cell death. Furthermore, we systematically catalog the existing epigenetic pharmacological agents targeting novel forms of RCD and their mechanisms of action in cardiovascular diseases. This article aims to underscore the pivotal role of epigenetic modifications in precisely regulating specific pathways of novel RCD in cardiovascular diseases, thus offering potential new therapeutic avenues that may prove more effective and safer than traditional treatments.

The Role of the SIRT1-mTOR Signaling Pathway in Regulating Autophagy in Sevoflurane-Induced Apoptosis of Fetal Rat Brain Neurons

BACKGROUND

Isoflurane is a commonly used general anesthetic widely employed in clinical surgeries. Recent studies have indicated that isoflurane might induce negative impacts on the nervous system, notably by triggering neuronal apoptosis. This process is pivotal to the development and emergence of neurological disorders; its misregulation could result in functional deficits and the initiation of diseases within nervous system. However, the potential molecular mechanism of isoflurane on the neuronal apoptosis remains fully unexplored. This study aims to investigate the regulatory role of the sirtuin 1-mechanistic target of rapamycin (SIRT1-mTOR) signaling pathway in autophagy during isoflurane-induced apoptosis of fetal rat brain neuronal cells.

METHODS

Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, real-time quantitative polymerase chain reaction (qPCR), and Western blot were utilized to evaluate the apoptotic status of hippocampal tissue cells in fetal mice after sevoflurane exposure. Our further investigation was commenced with flow cytometry, immunofluorescence, qPCR, and Western blot to determine the impact of autophagy on sevoflurane-induced apoptosis in these neurons. On the other hand, we conducted an additional set of analyses, including flow cytometric analysis, qPCR, and Western blot, to further elucidate the neuroprotective potential of autophagy in neural cells of fetal mice subjected to sevoflurane-induced apoptosis.

RESULTS

Our findings indicated that a 3% sevoflurane treatment led to a significant rise in apoptosis among fetal rat hippocampal tissue cells and neurons. Levels of apoptosis-associated proteins, cleaved-caspase-3 and Bcl-2 associated X protein (Bax), were found to be markedly higher, coinciding with an enhancement in autophagy as evidenced by increased microtubule-associated proteins 1A/1B-light chain 3 (LC3) and decreased p62 expression. Concurrently, there was a notable up-regulation of sirtuin 1 (SIRT1) and a down-regulation of mechanistic target of rapamycin (mTOR) expression. In conclusion, our research elucidated the pivotal function of cellular autophagy in an apoptosis induced by sevoflurane in fetal rat nerve cells. Through experimental manipulation, we observed that interference with SIRT1 resulted in a reduction of both cleaved-caspase-3 and Bax levels. This intervention also beget a diminished expression of the autophagy-associated factor LC3 and an up-regulation of p62. Furthermore, inhibition against mTOR reversed the effects induced by SIRT1 interference, suggesting a complex interplay amid these regulatory pathways.

CONCLUSIONS

SIRT1 possesses a capacity to modulate apoptosis in the hippocampal neurons of fetal rats triggered by sevoflurane, with mTOR functioning as an inhibitory factor within this signaling pathway.

Extracellular Vesicle-Derived Non-Coding RNAs: Key Mediators in Remodelling Heart Failure

Heart failure (HF), a syndrome of persistent development of cardiac insufficiency due to various heart diseases, is a serious and lethal disease for which specific curative therapies are lacking and poses a severe burden on all aspects of global public health. Extracellular vesicles (EVs) are essential mediators of intercellular and interorgan communication, and are enclosed nanoscale vesicles carrying biomolecules such as RNA, DNA, and proteins. Recent studies have showed, among other things, that non-coding RNAs (ncRNAs), especially microRNAs (miRNAs), long ncRNAs (lncRNA), and circular RNAs (circRNAs) can be selectively sorted into EVs and modulate the pathophysiological processes of HF in recipient cells, acting on both healthy and diseased hearts, which makes them promising targets for the diagnosis and therapy of HF. This review aims to explore the mechanism of action of EV-ncRNAs in heart failure, with emphasis on the potential use of differentially expressed miRNAs and circRNAs as biomarkers of cardiovascular disease, and recent research advances in the diagnosis and treatment of heart failure. Finally, we focus on summarising the latest advances and challenges in engineering EVs for HF, providing novel concepts for the diagnosis and treatment of heart failure.

Isoliquiritigenin attenuates myocardial ischemia reperfusion through autophagy activation mediated by AMPK/mTOR/ULK1 signaling

BACKGROUND

Ischemia reperfusion (IR) causes impaired myocardial function, and autophagy activation ameliorates myocardial IR injury. Isoliquiritigenin (ISO) has been found to protect myocardial tissues via AMPK, with exerting anti-tumor property through autophagy activation. This study aims to investigate ISO capacity to attenuate myocardial IR through autophagy activation mediated by AMPK/mTOR/ULK1 signaling.

METHODS

ISO effects were explored by SD rats and H9c2 cells. IR rats and IR-induced H9c2 cell models were established by ligating left anterior descending (LAD) coronary artery and hypoxia/re-oxygenation, respectively, followed by low, medium and high dosages of ISO intervention (Rats: 10, 20, and 40 mg/kg; H9c2 cells: 1, 10, and 100 μmol/L). Myocardial tissue injury in rats was assessed by myocardial function-related index, HE staining, Masson trichrome staining, TTC staining, and ELISA. Autophagy of H9c2 cells was detected by transmission electron microscopy (TEM) and immunofluorescence. Autophagy-related and AMPK/mTOR/ULK1 pathway-related protein expressions were detected with western blot.

RESULTS

ISO treatment caused myocardial function improvement, and inhibition of myocardial inflammatory infiltration, fibrosis, infarct area, oxidative stress, CK-MB, cTnI, and cTnT expression in IR rats. In IR-modeled H9c2 cells, ISO treatment lowered apoptosis rate and activated autophagy and LC3 fluorescence expression. In vivo and in vitro, ISO intervention exhibited enhanced Beclin1, LC3II/LC3I, and p-AMPK/AMPK levels, whereas inhibited P62, p-mTOR/mTOR and p-ULK1(S757)/ULK1 protein expression, activating autophagy and protecting myocardial tissues from IR injury.

CONCLUSION

ISO treatment may induce autophagy by regulating AMPK/mTOR/ULK1 signaling, thereby improving myocardial IR injury, as a potential candidate for treatment of myocardial IR injury.

The function and therapeutic potential of transfer RNA-derived small RNAs in cardiovascular diseases: A review

Transfer RNA-derived small RNAs (tsRNAs) are a class of small non-coding RNA (sncRNA) molecules derived from tRNA, including tRNA derived fragments (tRFs) and tRNA halfs (tiRNAs). tsRNAs can affect cell functions by participating in gene expression regulation, translation regulation, intercellular signal transduction, and immune response. They have been shown to play an important role in various human diseases, including cardiovascular diseases (CVDs). Targeted regulation of tsRNAs expression can affect the progression of CVDs. The tsRNAs induced by pathological conditions can be detected when released into the extracellular, giving them enormous potential as disease biomarkers. Here, we review the biogenesis, degradation process and related functional mechanisms of tsRNAs, and discuss the research progress and application prospects of tsRNAs in different CVDs, to provide a new perspective on the treatment of CVDs.

The role of quercetin in ameliorating bleomycin-induced pulmonary fibrosis: insights into autophagy and the SIRT1/AMPK signaling pathway

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a disease of unknown etiology characterized by a constant incidence rate. Unfortunately, effective pharmacological treatments for this condition are lacking and the identification of novel therapeutic approaches and underlying pathological mechanisms are required. This study investigated the potential of quercetin in alleviating pulmonary fibrosis by promoting autophagy and activation of the SIRT1/AMPK pathway.

METHODS

Mouse models of IPF were divided into four treatment groups: control, bleomycin (BLM), quercetin (Q), and quercetin + EX-527 (Q + E) treatment. Pulmonary fibrosis was induced in the mouse models through intratracheal instillation of BLM. Various indexes were identified through histological staining, Western blotting analysis, enzyme-linked immunosorbent assay, immunohistochemistry, and transmission electron microscopy.

RESULTS

Quercetin treatment ameliorated the pathology of BLM-induced pulmonary fibrosis of mice by reducing α-smooth muscle actin (α-SMA), collagen I (Col I), and collagen III (Col III) levels, and also improved the level of E-cadherin in lung tissue. Furthermore, Quercetin significantly enhanced LC3II/LC3I levels, decreased P62 expression, and increased the number of autophagosomes in lung tissue. These effects were accompanied by the activation of the SIRT1/AMPK pathway. Treatment with EX-527, an inhibitor for SIRT1, reversed all effects induced by quercetin.

CONCLUSION

This study showed that quercetin could alleviate pulmonary fibrosis and improve epithelial-mesenchymal transition by acting on the SIRT1/AMPK signaling pathway, which may be achieved by regulating the level of autophagy.

Caffeic acid phenethyl ester inhibits neuro-inflammation and oxidative stress following spinal cord injury by mitigating mitochondrial dysfunction via the SIRT1/PGC1α/DRP1 signaling pathway

BACKGROUND

The treatment of spinal cord injury (SCI) has always been a significant research focus of clinical neuroscience, with inhibition of microglia-mediated neuro-inflammation as well as oxidative stress key to successful SCI patient treatment. Caffeic acid phenethyl ester (CAPE), a compound extracted from propolis, has both anti-inflammatory and anti-oxidative effects, but its SCI therapeutic effects have rarely been reported.

METHODS

We constructed a mouse spinal cord contusion model and administered CAPE intraperitoneally for 7 consecutive days after injury, and methylprednisolone (MP) was used as a positive control. Hematoxylin-eosin, Nissl, and Luxol Fast Blue staining were used to assess the effect of CAPE on the structures of nervous tissue after SCI. Basso Mouse Scale scores and footprint analysis were used to explore the effect of CAPE on the recovery of motor function by SCI mice. Western blot analysis and immunofluorescence staining assessed levels of inflammatory mediators and oxidative stress-related proteins both in vivo and in vitro after CAPE treatment. Further, reactive oxygen species (ROS) within the cytoplasm were detected using an ROS kit. Changes in mitochondrial membrane potential after CAPE treatment were detected with 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine iodide. Mechanistically, western blot analysis and immunofluorescence staining were used to examine the effect of CAPE on the SIRT1/PGC1α/DRP1 signaling pathway.

RESULTS

CAPE-treated SCI mice showed less neuronal tissue loss, more neuronal survival, and reduced demyelination. Interestingly, SCI mice treated with CAPE showed better recovery of motor function. CAPE treatment reduced the expression of inflammatory and oxidative mediators, including iNOS, COX-2, TNF-α, IL-1β, 1L-6, NOX-2, and NOX-4, as well as the positive control MP both in vitro and in vivo. In addition, molecular docking experiments showed that CAPE had a high affinity for SIRT1, and that CAPE treatment significantly activated SIRT1 and PGC1α, with down-regulation of DRP1. Further, CAPE treatment significantly reduced the level of ROS in cellular cytoplasm and increased the mitochondrial membrane potential, which improved normal mitochondrial function. After administering the SIRT1 inhibitor nicotinamide, the effect of CAPE on neuro-inflammation and oxidative stress was reversed.On the contrary, SIRT1 agonist SRT2183 further enhanced the anti-inflammatory and antioxidant effects of CAPE, indicating that the anti-inflammatory and anti-oxidative stress effects of CAPE after SCI were dependent on SIRT1.

CONCLUSION

CAPE inhibits microglia-mediated neuro-inflammation and oxidative stress and supports mitochondrial function by regulating the SIRT1/PGC1α/DRP1 signaling pathway after SCI. These effects demonstrate that CAPE reduces nerve tissue damage. Therefore, CAPE is a potential drug for the treatment of SCI through production of anti-inflammatory and anti-oxidative stress effects.

Angiotensin-converting enzyme inhibitors provide a protective effect on hypoxia-induced injury in human coronary artery endothelial cells via Nrf2 signaling and PLVAP

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACEIs) were reported to protect from hypoxia-induced oxidative stress in coronary endothelial cells (CECs) after acute myocardial infarction (AMI). Nrf2 shows a protective effect in hypoxia-induced CECs after AMI. Plasmalemma vesicle-associated protein (PLVAP) plays a pivotal role in angiogenesis after AMI.

AIM

To explore the protective effect of ACEIs and the involved mechanisms under hypoxia challenge.

METHODS

Human coronary endothelial cells (HCAECs) were used to establish hypoxia-induced oxidative stress injury in vitro. Flow cytometry was used to evaluate the protective effect of ACEI on hypoxia conditions.ET-1, NO, ROS, and VEGF were detected by ELISA. HO-1, Nrf2, and Keap-1, the pivotal member in the Nrf2 signaling pathway, eNOS and PLVAP were detected in HEAECs treated with ACEI by immunofluorescence, qPCR, and western blotting.

RESULTS

The hypoxia ACEI or Nrf2 agonist groups showed higher cell viability compared with the hypoxia control group at 24 (61.75±1.16 or 61.23±0.59 vs. 44.24±0.58, both P < 0.05) and 48 h (41.85±1.19 or 59.64±1.13 vs. 22.98±0.25, both P < 0.05). ACEI decreased the levels of ET-1 and ROS under hypoxia challenge at 24 and 48 h (all P < 0.05); ACEI increased the VEGF and NO levels (all P < 0.05). ACEI promoted the expression level of eNOS, HO-1, Nrf2 and PLVAP but inhibited Keap-1 expression at the mRNA and protein levels (all P < 0.05). Blockade of the Nrf2 signaling pathway significantly decreased the expression level of PLVAP.

CONCLUSION

ACEI protects hypoxia-treated HEAECs by activating the Nrf2 signaling pathway and upregulating the expression of PLVAP.