Poly(I:C) preconditioning protects the heart against myocardial ischemia/reperfusion injury through TLR3/PI3K/Akt-dependent pathway

RNA-binding protein PTENα blocks RIG-I activation to prevent viral inflammation

A timely inflammatory response is crucial for early viral defense, but uncontrolled inflammation harms the host. Retinoic acid-inducible gene I (RIG-I) has a pivotal role in detecting RNA viruses, yet the regulatory mechanisms governing its sensitivity remain elusive. Here we identify PTENα, an N-terminally extended form of PTEN, as an RNA-binding protein with a preference for the CAUC(G/U)UCAU motif. Using both in vivo and in vitro viral infection assays, we demonstrated that PTENα restricted the host innate immune response, relying on its RNA-binding capacity and phosphatase activity. Mechanistically, PTENα directly bound to viral RNA and enzymatically converted its 5'-triphosphate to 5'-monophosphate, thereby reducing RIG-I sensitivity. Physiologically, brain-intrinsic PTENα exerted protective effects against viral inflammation, while peripheral PTENα restricted host antiviral immunity and, to some extent, promoted viral replication. Collectively, our findings underscore the significance of PTENα in modulating viral RNA- and RIG-I-mediated immune recognition, offering potential therapeutic implications for infectious diseases.

Lipopolysaccharide Induces Trained Innate Immune Tolerance in the Heart Through Interferon Signaling in a Model of Stress-Induced Cardiomyopathy

Background

Although the ability of the heart to adapt to environmental stress has been studied extensively, the molecular and cellular mechanisms responsible for cardioprotection are not yet fully understood.

Methods

We administered Toll-like receptor (TLR) agonists or a diluent to wild-type mice and assessed their potential to induce cardiac protection against injury from a high intraperitoneal dose of isoproterenol (ISO) administered 7 days later. Cardioprotective effects were analyzed through serum cardiac troponin I levels, immune cell profiling via flow cytometry, echocardiography, and multiomic single-nuclei RNA and ATAC sequencing.

Results

Pretreatment with the TLR4 agonist lipopolysaccharide (LPS), but not TLR1/2 or TLR3 agonists, conferred cardioprotection against ISO, as demonstrated by reduced cardiac troponin I leakage, decreased inflammation, preservation of cardiac structure and function, and improved survival. Remarkably, LPS-induced tolerance was reversed by β-glucan treatment. Multiomic analysis showed that LPS-tolerized hearts had greater chromatin accessibility and upregulated gene expression compared to hearts treated with LPS and β-glucan (reverse-tolerized). The LPS tolerance was associated with upregulation of interferon response pathways across various cell types, including cardiac myocytes and stromal cells. Blocking both type 1 and type 2 interferon signaling eliminated LPS-induced tolerance against ISO, while pretreatment with recombinant type 1 and 2 interferons conferred cardiac protection. Multiomic sequencing further revealed enhanced cytoprotective signaling in interferon-treated hearts. Analysis of cell-cell communication networks indicated increased autocrine signaling by cardiac myocytes, as well as greater paracrine signaling between stromal cells and myeloid cells, in LPS-tolerized versus reverse-tolerized hearts.

Conclusions

LPS pretreatment confers cardiac protection against ISO-induced injury through TLR4 mediated type 1 and 2 interferon signaling, consistent with trained innate immune tolerance. The observation that LPS-induced protection in cardiac myocytes involves both cell-autonomous and non-cell-autonomous mechanisms underscores the complexity of innate immune tolerance in the heart, warranting further investigation into this cardioprotective phenotype.

Clinical Perspective

What is new?: The Toll-like receptor 4 (TLR4) agonist lipopolysaccharide (LPS) confers cardiac protection against isoproterenol-mediated injury in a manner consistent with trained innate immune tolerance, which is reversed by β-glucan treatment.Activation of type 1 and 2 interferon signaling, which is downstream of Toll-like receptor 4, is necessary and sufficient for LPS-induced cardiac protection.LPS-tolerized hearts show heightened autocrine signaling by cardiac myocytes and, to a greater degree, increased cell-cell communication between cardiac myocytes and stromal and myeloid cells compared to reverse-tolerized hearts.What are the clinical implications?: TLR4 and interferon signaling play key roles in the establishment of cardiac protection and LPS-induced trained innate immune tolerance.The protective effects of LPS are mediated by cell-autonomous and non-cell-autonomous mechanisms, suggesting that a deeper understanding of the molecular and cellular signatures of innate immune tolerance is required for the development of targeted approaches to modulate trained innate immunity, and consequently cytoprotection, in the heart.

Acute effects of TLR3 agonist Poly(I:C) on bone marrow hematopoietic progenitor cells in mice

Hematopoietic progenitor cells (HPCs) in bone marrow with limited abilities for self-renewal and differentiation continuously supply hematopoietic cells through life. When suffering infection or inflammation, HPCs will actively proliferate to provide differentiated hematopoietic cells to maintain hematopoietic homeostasis. Poly(I:C), an agonist of TLR3, can specifically activate Type I interferon (IFN-I) signaling which exerts anti-inflammatory effects and influence hematopoiesis after infection. However, the effects of Poly(I:C)-induced IFN-I on the bone marrow hematopoietic system still deserve attention. In this study, our results revealed the efficacy of the IFN-I model, with a remarkably decrease in HPCs and a sharp elevation in LSKs numbers after single dose of Poly(I:C) injection. Apoptotic ratios of HPCs and LSKs significantly increased 48 h after Poly(I:C) treatment. Application of Poly(I:C) prompted the transition of HPCs and LSKs from G0 to G1 phases, potentially leading to the accelerated exhaustion of HPCs. From the cobblestone area-forming cell (CAFC) assay, we speculate that Poly(I:C) impairs the differentiation capacity of HPCs as well as their colony-forming ability. RT-qPCR and immunohistochemistry revealed significant upregulation of IFN-I associated genes and proteins following Poly(I:C) treatment. In conclusion, a single dose of Poly(I:C) induced an acute detrimental effect on HPCs within 48 h potentially due to TLR3 engagement. This activation cascaded into a robust IFN-I response emanating from the bone marrow, underscoring the intricate immunological dynamics at play following Poly(I:C) intervention.

Emodin alleviates intestinal ischemia/reperfusion-induced lung injury by upregulating HO-1 expression via PI3K/AkT pathway

BACKGROUND

Emodin, a natural anthraquinone derivative found in various Chinese medicinal herbs, has been proved to be an effective therapeutic agent in the treatment of many diseases. However, its effect on lung injury after intestinal ischemia/reperfusion injury remains unknown. This research was designed to investigate whether emodin protects against intestinal ischemia/reperfusion-induced lung injury and to elucidate the underlying molecular mechanisms in vivo and in vitro.

METHODS

Intestinal ischemia/reperfusion injury was induced by occluding the superior mesenteric artery in mice, and mouse lung epithelial-12 cells were subjected to oxygen-glucose deprivation and reoxygenation to establish an in vitro model.

RESULTS

Our data indicated that emodin treatment reduced intestinal ischemia/reperfusion-induced oxidative stress, inflammation and apoptosis in lung tissues and alleviated lung injury. However, the protective effects of emodin on intestinal ischemia/reperfusion-induced lung injury were reversed by the protein kinase B inhibitor triciribine or the heme oxygenase-1 inhibitor tin protoporphyrin IX. The protein kinase inhibitor triciribine also downregulated the expression of heme oxygenase-1.

CONCLUSION

In conclusion, our data suggest that emodin treatment protects against intestinal ischemia/reperfusion-induced lung injury by enhancing heme oxygenase-1 expression via activation of the PI3K/protein kinase pathway. Emodin may act as a potential therapeutic agent for the prevention and treatment of lung injury induced by intestinal ischemia/reperfusion.

Bibliometric analysis of research progress on tetramethylpyrazine and its effects on ischemia-reperfusion injury

In recent decades, natural products have attracted worldwide attention and become one of the most important resources for pharmacological industries and medical sciences to identify novel drug candidates for disease treatment. Tetramethylpyrazine (TMP) is an alkaloid extracted from Ligusticum chuanxiong Hort., which has shown great therapeutic potential in cardiovascular and cerebrovascular diseases, liver and renal injury, as well as cancer. In this review, we analyzed 1270 papers published on the Web of Science Core Collection from 2002 to 2022 and found that TMP exerted significant protective effects on ischemia-reperfusion (I/R) injury that is the cause of pathological damages in a variety of conditions, such as ischemic stroke, myocardial infarction, acute kidney injury, and liver transplantation. TMP is limited in clinical applications to some extent due to its rapid metabolism, a short biological half-life and poor bioavailability. Obviously, the structural modification, administration methods and dosage forms of TMP need to be further investigated in order to improve its bioavailability. This review summarizes the clinical applications of TMP, elucidates its potential mechanisms in protecting I/R injury, provides strategies to improve bioavailability, which presents a comprehensive understanding of the important compound. Hopefully, the information and knowledge from this review can help researchers and physicians to better improve the applications of TMP in the clinic.

Sevoflurane enhances autophagy via Rac1 to attenuate lung ischaemia‒reperfusion injury

Sevoflurane can attenuate lung ischaemia‒reperfusion injury (LIRI). However, the protective mechanism is unclear. In this study, we developed a LIRI model in vivo that animals (SD, n = 15) were subjected to the administration of 2.2 % sevoflurane 30 min before the onset of left pulmonary artery clamping for 45 min, which was then followed by 60 min of reperfusion treatment. Then, transcriptome sequencing was used to analyse lung tissues. Autophagy inhibition (3-MA) and Rac1-overexpression transfection plasmids were used in BEAS-2B cells, and BEAS-2B cells were subjected to hypoxia reoxygenation (H/R) and sevoflurane treatment. In both animal tissue and cells, inflammatory cytokines and apoptotic and autophagy molecules were measured by quantitative real-time PCR, western blotting and immunostaining. As a result, decreased arterial partial oxygen and damage to the histological structure of lung tissues were observed in LIRI model rats, and these effects were reversed by sevoflurane treatment. Activation of inflammation (elevated IL-1β, IL-6, and TNF-α) and apoptosis (elevated cleaved caspase3/caspase3 and Bax, degraded expression of Bcl2) and inhibition of autophagy (elevated P62, degraded expression of Beclin1 and LC3-II/LC3I) in the model group were ameliorated by sevoflurane. Transcriptome sequencing indicated that the PI3K/Akt pathway regulated by Rac1 plays an important role in LIRI. Furthermore, overexpression of Rac1 in a cell line inhibited the protective effect of sevoflurane in LIRI. Autophagy inhibition (3-MA) also prevented the protective effect of sevoflurane on inflammation and apoptosis. As shown in the present study, sevoflurane enhances autophagy via Rac1/PI3K/AKT signalling to attenuate lung ischaemia‒reperfusion injury.

Role of Brain-Derived Neurotrophic Factor in Anxiety or Depression After Percutaneous Coronary Intervention

Anxiety or depression after percutaneous coronary intervention (PCI) is one of the key clinical problems in cardiology that need to be solved urgently. Brain-derived neurotrophic factor (BDNF) may be a potential biomarker for the pathogenesis and treatment of anxiety or depression after PCI. This article reviews the correlation between BDNF and cardiovascular system and nervous system from the aspects of synthesis, release and action site of BDNF, and focuses on the latest research progress of the mechanism of BDNF in anxiety or depression after PCI. It includes the specific mechanisms by which BDNF regulates the levels of inflammatory factors, reduces oxidative stress damage, and mediates multiple signaling pathways. In addition, this review summarizes the therapeutic potential of BDNF as a potential biomarker for anxiety or depression after PCI.

Shuxuening Injection Inhibits Apoptosis and Reduces Myocardial Ischemia-Reperfusion Injury in Rats through PI3K/AKT Pathway

OBJECTIVE

To investigate the main components and potential mechanism of Shuxuening Injection (SXNI) in the treatment of myocardial ischemia-reperfusion injury (MIRI) through network pharmacology and in vivo research.

METHODS

The Traditional Chinese Medicine Systems Pharmacology (TCMSP) and PharmMapper databases were used to extract and evaluate the effective components of Ginkgo biloba leaves, the main component of SXNI. The Online Mendelian Inheritance in Man (OMIM) and GeneCards databases were searched for disease targets and obtain the drug target and disease target intersections. The active ingredient-target network was built using Cytoscape 3.9.1 software. The STRING database, Metascape online platform, and R language were used to obtain the key targets and signaling pathways of the anti-MIRI effects of SXNI. In order to verify the therapeutic effect of different concentrations of SXNI on MIRI in rats, 60 rats were first divided into 5 groups according to random number table method: the sham operation group, the model group, SXNI low-dose (3.68 mg/kg), medium-dose (7.35 mg/kg), and high-dose (14.7 mg/kg) groups, with 12 rats in each group. Then, another 60 rats were randomly divided into 5 groups: the sham operation group, the model group, SXNI group (14.7 mg/kg), SXNI+LY294002 group, and LY294002 group, with 12 rats in each group. The drug was then administered intraperitoneally at body weight for 14 days. The main biological processes were validated using in vivo testing. Evans blue/triphenyltetrazolium chloride (TTC) double staining, hematoxylin-eosin (HE) staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, enzyme-linked immunosorbent assay (ELISA), and Western blot analysis were used to investigate the efficacy and mechanism of SXNI in MIRI rats.

RESULTS

Eleven core targets and 30 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were selected. Among these, the phosphoinositide 3-kinase (PI3K)/ protein kinase B (AKT) pathway was closely related to SXNI treatment of MIRI. In vivo experiments showed that SXNI reduced the myocardial infarction area in the model group, improved rat heart pathological damage, and reduced the cardiomyocyte apoptosis rate (all P<0.01). After SXNI treatment, the p-PI3K/PI3K and p-AKT/AKT ratios as well as B-cell lymphoma-2 (Bcl-2) protein expression in cardiomyocytes were increased, while the Bax and cleaved caspase 3 protein expression levels were decreased (all P<0.05). LY294002 partially reversed the protective effect of SXNI on MIRI.

CONCLUSION

SXNI protects against MIRI by activating the PI3K/AKT signaling pathway.

Mechanism of Danggui Buxue decoction in the treatment of myocardial infarction based on network pharmacology and experimental identification

Background

Myocardial infarction (MI) remains one of the major causes of high morbidity and mortality worldwide. Danggui Buxue Decoction (DBD)-an ancient Chinese herbal decoction-has been used to prevent coronary heart disease, which was called "chest palsy" in ancient clinics. However, the mechanism of DBD in the treatment of MI remains unclear. The aim of this study was to explore the effect and mechanism of DBD on MI by combining network pharmacology with in vivo experiments.

Materials and methods

First, public databases were used to identify the key active chemicals and possible targets of DBD. The MI targets were obtained from the Therapeutic Target Database, and the function of the target genes in relation to linked pathways was investigated. Subsequently, Cytoscape software was used to build a target-signaling pathway network. Finally, the efficacy of DBD therapy on MI was validated using in vivo investigations combined with molecular docking.

Results

In traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP), 27 bioactive compounds were screened from DBD. A total of 213 common targets were obtained, including 507 DBD targets and 2566 MI targets. Enrichment analysis suggests that PI3K/AKT is a potential signaling pathway for DBD-based protection. Immunofluorescence and protein blotting confirmed PI3K/AKT1, ERK2, and CASPASE-9 as the target proteins. Molecular docking analysis showed that quercetin, kaempferol, isoflavanones, isorhamnetin, hederagenin, and formononetin had high binding affinity to AKT1, ERK2, and CASPASE-9.

Conclusions

This study demonstrated that the therapeutic benefit of DBD on MI may be mediated via target proteins in the PI3K/AKT pathway, such as AKT1, ERK2, and CASPASE-9. Our study data can help to provide ideas and identify new treatment targets for MI.

Ambient particulate matter exposure induces ferroptosis in hippocampal cells through the GSK3B/Nrf2/GPX4 pathway

Epidemiological studies have established a robust correlation between exposure to ambient particulate matter (PM) and various neurological disorders, with dysregulation of intracellular redox processes and cell death being key mechanisms involved. Ferroptosis, a cell death form characterized by iron-dependent lipid peroxidation and disruption of antioxidant defenses, may be involved in the neurotoxic effects of PM exposure. However, the relationship between PM-induced neurotoxicity and ferroptosis in nerve cells remains to be elucidated. In this study, we utilized a rat model (exposed to PM at a dose of 10 mg/kg body weight per day for 4 weeks) and an HT-22 cell model (exposed to PM at concentrations of 50, 100, and 200 μg/mL for 24 h) to investigate the potential induction of ferroptosis by PM exposure. Furthermore, RNA sequencing analysis was employed to identify hub genes that potentially contribute to the process of ferroptosis, which was subsequently validated through in vivo and in vitro experiments. The results revealed that PM exposure increased MDA content and Fe2+ levels, and decreased SOD activity and GSH/GSSG ratio in rat hippocampal and HT-22 cells. Through RNA sequencing analysis, bioinformatics analysis, and RT-qPCR experiments, we identified GSK3B as a possible hub gene involved in ferroptosis. Subsequent investigations demonstrated that PM exposure increased GSK3B levels and decreased Nrf2, and GPX4 levels in vivo and in vitro. Furthermore, treatment with LY2090314, a specific inhibitor of GSK3B, was found to mitigate the PM-induced elevation of MDA and ROS and restore SOD activity and GSH/GSSG ratio. The LY2090314 treatment promoted the upregulation of Nrf2 and GPX4 and facilitated the nuclear translocation of Nrf2 in HT-22 cells. Moreover, treatment with LY2090314 resulted in the upregulation of Nrf2 and GPX4, along with the facilitation of nuclear translocation of Nrf2. This study suggested that PM-induced ferroptosis in hippocampal cells may be via the GSK3B/Nrf2/GPX4 pathway.

Enhanced VEGF secretion and blood-brain barrier disruption: Radiation-mediated inhibition of astrocyte autophagy via PI3K-AKT pathway activation

Radiation-induced damage to the blood-brain barrier (BBB) is the recognized pathological basis of radiation-induced brain injury (RBI), a side effect of head and neck cancer treatments. There is currently a lack of therapeutic approaches for RBI due to the ambiguity of its underlying mechanisms. Therefore, it is essential to identify these mechanisms in order to prevent RBI or provide early interventions. One crucial factor contributing to BBB disruption is the radiation-induced activation of astrocytes and oversecretion of vascular endothelial growth factor (VEGF). Mechanistically, the PI3K-AKT pathway can inhibit cellular autophagy, leading to pathological cell aggregation. Moreover, it acts as an upstream pathway of VEGF. In this study, we observed the upregulation of the PI3K-AKT pathway in irradiated cultured astrocytes through bioinformatics analysis, we then validated these findings in animal brains and in vitro astrocytes following radiation exposure. Additionally, we also found the inhibition of autophagy and the oversecretion of VEGF in irradiated astrocytes. By inhibiting the PI3K-AKT pathway or promoting cellular autophagy, we observed a significant amelioration of the inhibitory effect on autophagy, leading to reductions in VEGF oversecretion and BBB disruption. In conclusion, our study suggests that radiation can inhibit autophagy and promote VEGF oversecretion by upregulating the PI3K-AKT pathway in astrocytes. Blocking the PI3K pathway can alleviate both of these effects, thereby mitigating damage to the BBB in patients undergoing radiation treatment.

N-n-butyl haloperidol iodide mediates cardioprotection via regulating AMPK/FoxO1 signalling

Derangement of redox condition largely contributes to cardiac ischemia/reperfusion (I/R) injury. FoxO1 is a transcription factor which transcripts a series of antioxidants to antagonize I/R-induced oxidative myocardial damage. N-n-butyl haloperidol iodide (F2 ) is a derivative derived from haloperidol structural modification with potent capacity of inhibiting oxidative stress. This investigation intends to validate whether cardio-protection of F2 is dependent on FoxO1 using an in vivo mouse I/R model and if so, to further elucidate the molecular regulating mechanism. This study initially revealed that F2 preconditioning led to a profound reduction in I/R injury, which was accompanied by attenuated oxidative stress and upregulation of antioxidants (SOD2 and catalase), nuclear FoxO1 and phosphorylation of AMPK. Furthermore, inactivation of FoxO1 with AS1842856 abolished the cardio-protective effect of F2 . Importantly, we identified F2 -mediated nuclear accumulation of FoxO1 is dependent on AMPK, as blockage of AMPK with compound C induced nuclear exit of FoxO1. Collectively, our data uncover that F2 pretreatment exerts significant protection against post ischemic myocardial injury by its regulation of AMPK/FoxO1 pathway, which may provide a new avenue for treating ischemic disease.

Hepatoprotective effect of total flavonoids from Carthamus tinctorius L. leaves against carbon tetrachloride-induced chronic liver injury in mice

Carthamus tinctorius L. leaves, a waste product after Carthami flos production, are rich in flavonoids. Total flavonoids from C. tinctorius L. leaves (TFCTLL) exhibited the protective effect on acute liver injury in mice in previous studies. The aim of the present study was to evaluate the hepatoprotective effect of TFCTLL on chronic liver injury (CLI) and investigate the underlying mechanism. The chemical components of TFCTLL were identified by UPLC-Q-TOF/MS, and their migration into blood was evaluated. The protective effect of TFCTLL on CLI was evaluated by antioxidative and anti-inflammatory experiments in vitro, network pharmacology and a carbon tetrachloride (CCl4)-induced CLI mouse model. We indentified 18 chemical components in the TFCTLL samples and 4 components in plasma. TFCTLL showed significant anti-inflammatory activity and antioxidant capacity in vitro and in vivo. TFCTLL administration prominently improved the liver function and structure, decreased the mRNA expression levels of TLR2, TLR3, TLR4, NF-κB p65, IRF3, AKT1, TRIF, PI3K, MyD88, IL-1β and TNF-α and inhibited the protein expression and nuclear translocation of NF-κB p65 in mice with CLI. The molecular docking results showed that components in plasma had high binding affinity for the targets TLR4, PI3K and AKT1. Therefore, TFCTLL has a protective effect against CCl4-induced CLI, and the underlying mechanisms may be related to antioxidation, anti-inflammation and modulation of the TLRs/NF-κB and PI3K/AKT pathways.

BMP7 alleviates trigeminal neuralgia by reducing oligodendrocyte apoptosis and demyelination

BACKGROUND

BMP7 has been shown to have neuroprotective effects and to alleviate demyelination. However, its role in trigeminal neuralgia (TN) has not been well investigated. The current study aims to determine whether BMP7 plays a role in demyelination, its effects on pain behaviors and mechanism of action in rats with TN.

METHODS

We used an infraorbital-nerve chronic-constriction injury (ION-CCI) to establish a rat model of TN. Adeno-associated viruses (AAVs) were injected into the rats to upregulate or downregulate BMP7. The mechanical withdrawal thresholds (MWT) of the injured rats were detected using Von Frey filaments. The changes in expression levels of BMP7 and oligodendrocyte (OL) markers were examined by western blotting, quantitative real-time PCR, immunofluorescence, and transmission electron microscopy.

RESULTS

The ION-CCI induced mechanical allodynia, demyelination, and loss of OLs with a reduction of BMP7. Short-hairpin RNA (shRNA)-BMP7 that inhibited BMP7 expression also caused mechanical allodynia, demyelination, and loss of OLs, and its mechanism may be OL apoptosis. Overexpressing BMP7 in the trigeminal spinal subnucleus caudalis(VC) with AAV-BMP7 relieved all three phenotypes induced by the CCI, and its mechanism may be alleviating OLs apoptosis. Two signal pathways associated with apoptosis, STAT3 and p65, were significantly downregulated in the VC after CCI and rescued by BMP7 overexpression.

CONCLUSION

BMP7 can alleviate TN by reducing OLs apoptosis and subsequent demyelination. The mechanism behind this protection could be BMP7-mediated activation of the STAT3 and NF-κB/p65 signaling pathway and subsequent decrease in OL apoptosis. Importantly, our study presents clear evidence in support of BMP7 as a possible therapeutic target for the treatment of TN.

Cinnamaldehyde protects donor heart from cold ischemia-reperfusion injury via the PI3K/AKT/mTOR pathway

With the growing shortage of organs, improvements in donor organ protection are needed to meet the increasing demands for transplantation. Here, the aim was to investigate the protective effect of cinnamaldehyde against ischemia-reperfusion injury (IRI) in donor hearts exposed to prolonged cold ischemia. Donor hearts were harvested from rats pretreated with or without cinnamaldehyde, then subjected to 24 h of cold preservation and 1 h of ex vivo perfusion. Hemodynamic changes, myocardial inflammation, oxidative stress, and myocardial apoptosis were evaluated. The PI3K/AKT/mTOR pathway involved in the cardioprotective effects of cinnamaldehyde was explored through RNA sequencing and western blot analysis. Intriguingly, cinnamaldehyde pretreatment remarkably improved cardiac function through increasing coronary flow, left ventricular systolic pressure, +dp/dtmax, and -dp/dtmax, decreasing coronary vascular resistance and left ventricular end-diastolic pressure. Moreover, our findings indicated that cinnamaldehyde pretreatment protected the heart from IRI by alleviating myocardial inflammation, attenuating oxidative stress, and reducing myocardial apoptosis. Further studies showed that the PI3K/AKT/mTOR pathway was activated after cinnamaldehyde treatment during IRI. The protective effects of cinnamaldehyde were abolished by LY294002. In conclusion, cinnamaldehyde pretreatment alleviated IRI in donor hearts suffering from prolonged cold ischemia. Cinnamaldehyde exerted cardioprotective effects through the activation of the PI3K/AKT/mTOR pathway.

Extracellular RNAs/TLR3 signaling contributes to acute intestinal injury induced by intestinal ischemia reperfusion in mice

Toll-like receptor 3 (TLR3), one pattern recognition receptor activated by viral and endogenous RNA, has been recently reported to regulate ischemia/reperfusion (I/R) injury in various organs. However, the role of TLR3 in the development of intestinal I/R injury remains unclear. The aim of this study is to evaluate the effects of extracellular RNAs/TLR3 signaling in intestinal I/R injury. An intestinal I/R injury model was established with superior mesenteric artery occlusion both in wild-type and TLR3 knockout (KO, ^-/-) mice, and MODE-K cells were subjected to hypoxia/reoxygenation (H/R) to mimic the I/R model in vivo. Extracellular RNAs (exRNAs), especially double-stranded RNAs (dsRNAs) co-localized with TLR3, were significantly increased both in vitro and in vivo. Compared with wild-type mice, TLR3 knockout obviously attenuated intestinal I/R injury. Both TLR3/dsRNA complex inhibitor and TLR3 siRNA administration reduced TLR3 expressions and subsequently inhibited intestinal inflammatory cytokine production and apoptosis. In conclusion, exRNAs/TLR3 signaling is a key mechanism that regulates intestinal I/R injury in adult mice, and the TLR3/dsRNA complex inhibitor can be an effective approach for attenuating intestinal I/R-induced inflammatory response and apoptosis.

Sufentanil inhibits Pin1 to attenuate renal tubular epithelial cell ischemia-reperfusion injury by activating the PI3K/AKT/FOXO1 pathway

BACKGROUND

Renal ischemia-reperfusion injury (RIRI) has become a great concern in clinical practice with high morbidity and mortality rates. Sufentanil has protective effects on IRI-induced organ injury. Herein, the effects of sufentanil on RIRI were investigated.

METHODS

RIRI cell model was established by hypoxia/reperfusion (H/R) stimulation. The mRNA and protein expressions were assessed using qRT-PCR and western blot. TMCK-1 cell viability and apoptosis were assessed using MTT assay and flow cytometry, respectively. The mitochondrial membrane potential and ROS level were detected by JC-1 mitochondrial membrane potential fluorescent probe and DCFH-DA fluorescent probe, respectively. LDH, SOD, CAT, GSH and MDA levels were determined by the kits. The interaction between FOXO1 and Pin1 promoter was analyzed using dual luciferase reporter gene and ChIP assays.

RESULTS

Our results revealed that sufentanil treatment attenuated H/R-induced cell apoptosis, mitochondrial membrane potential (MMP) dysfunction, oxidative stress, inflammation and activated PI3K/AKT/FOXO1 associated proteins, while these effects were reversed by PI3K inhibitor, suggesting that sufentanil attenuated RIRI via activating the PI3K/AKT/FOXO1 signaling pathway. We subsequently found that FOXO1 transcriptionally activated Pin1 in TCMK-1 cells. Pin1 inhibition ameliorated H/R-induced TCMK-1 cell apoptosis, oxidative stress and inflammation. In addition, as expected, the biological effects of sufentanil on H/R-treated TMCK-1 cells were abrogated by Pin1 overexpression.

CONCLUSION

Sufentanil reduced Pin1 expression through activation of the PI3K/AKT/FOXO1 signaling to suppress cell apoptosis, oxidative stress and inflammation in renal tubular epithelial cells during RIRI development.

Integrating UPLC-Q-Exactive Orbitrap/MS, network pharmacology and experimental validation to reveal the potential mechanism of Tibetan medicine Rhodiola granules in improving myocardial ischemia-reperfusion injury

ETHNOPHARMACOLOGY RELEVANCE

Rhodiola granules (RG) is a traditional Tibetan medicine prescription that can be used to improve the symptoms of ischemia and hypoxia in cardiovascular and cerebrovascular diseases. However, there is no report on its use to improve myocardial ischemia/reperfusion (I/R) injury, and its potential active ingredients and mechanism against myocardial ischemia/reperfusion (I/R) injury remain unclear.

AIM OF THE STUDY

This study aimed to reveal the potential bioactive components and underlying pharmacological mechanisms of RG in improving myocardial I/R injury through a comprehensive strategy.

MATERIALS AND METHODS

UPLC-Q-Exactive Orbitrap/MS technology was used to analyze the chemical components of RG, the potential bioactive components and targets were tracked and predicted by the SwissADME and SwissTargetPrediction databases, and the core targets were predicted through the PPI network, as well the functions and pathways were determined by GO and KEGG analysis. In addition, the molecular docking and ligation of the anterior descending coronary artery-induced rat I/R models were experimentally validated.

RESULTS

A total of 37 ingredients were detected from RG, including nine flavones, ten flavonoid glycosides, one glycoside, eight organic acids, four amides, two nucleosides, one amino acid, and two other components. Among them, 15 chemical components, such as salidroside, morin, diosmetin, and gallic acid were identified as key active compounds. Ten core targets, including AKT1, VEGF, PTGS2, and STAT3, were discovered through the analysis of the PPI network constructed from 124 common potential targets. These possible targets were involved in the regulation of oxidative stress and HIF-1/VEGF/PI3K-Akt signaling pathways. Furthermore, molecular docking confirmed that the potential bioactive compounds in RG have good potential binding abilities to AKT1, VEGFA, PTGS2, STAT3, and HIF-1α proteins. Then, the animal experiments showed that RG could significantly improve the cardiac function of I/R rats, reduce the size of myocardial infarction, improve the myocardial structure, and reduce the degree of myocardial fibrosis, inflammatory cell infiltration, and myocardial cell apoptosis rate in I/R rats. In addition, we also found that RG could decrease the concentration of AGE, Ox-LDL, MDA, MPO, XOD, SDH, Ca²⁺, and ROS, and increase the concentration of Trx, TrxR1, SOD, T-AOC, NO, ATP, Na⁺k⁺-ATPase, Ca²⁺-ATPase, and CCO. Moreover, RG could significantly down-regulate the expressions of Bax, Cleaved-caspase3, HIF-1α, and PTGS2, as well up-regulate the expressions of Bcl-2, VEGFA, p-AKT1, and p-STAT3.

CONCLUSION

In summary, we revealed for the first time the potential active ingredients and mechanisms of RG for myocardial I/R injury therapy through a comprehensive research strategy. RG may synergistically improve myocardial I/R injury through anti-inflammatory, regulating energy metabolism, and oxidative stress, improving I/R-induced myocardial apoptosis, which may be related to the HIF-1/VEGF/PI3K-Akt signaling pathway. Our study provides new insights into the clinical application of RG and also provides a reference for the development and mechanism research of other Tibetan medicine compound preparations.

Targeting WWP1 ameliorates cardiac ischemic injury by suppressing KLF15-ubiquitination mediated myocardial inflammation

Rationale: Previous studies have suggested that myocardial inflammation plays a critical role after ischemic myocardial infarction (MI); however, the underlying mechanisms still need to be fully elucidated. WW domain-containing ubiquitin E3 ligase 1 (WWP1) is considered as an important therapeutic target for cardiovascular diseases due to its crucial function in non-ischemic cardiomyopathy, though it remains unknown whether targeting WWP1 can alleviate myocardial inflammation and ischemic injury post-MI. Methods: Recombinant adeno-associated virus 9 (rAAV9)-cTnT-mediated WWP1 or Kruppel-like factor 15 (KLF15) gene transfer and a natural WWP1 inhibitor Indole-3-carbinol (I3C) were used to determine the WWP1 function in cardiomyocytes. Cardiac function, tissue injury, myocardial inflammation, and signaling changes in the left ventricular tissues were analyzed after MI. The mechanisms underlying WWP1 regulation of cardiomyocyte phenotypes in vitro were determined using the adenovirus system. Results: We found that WWP1 expression was up-regulated in cardiomyocytes located in the infarct border at the early phase of MI and in hypoxia-treated neonatal rat cardiac myocytes (NRCMs). Cardiomyocyte-specific WWP1 overexpression augmented cardiomyocyte apoptosis, increased infarct size and deteriorated cardiac function. In contrast, inhibition of WWP1 in cardiomyocytes mitigated MI-induced cardiac ischemic injury. Mechanistically, WWP1 triggered excessive cardiomyocyte inflammation after MI by targeting KLF15 to catalyze K48-linked polyubiquitination and degradation. Ultimately, WWP1-mediated degradation of KLF15 contributed to the up-regulation of p65 acetylation, and activated the inflammatory signaling of MAPK in ischemic myocardium and hypoxia-treated cardiomyocytes. Thus, targeting of WWP1 by I3C protected against cardiac dysfunction and remodeling after MI. Conclusions: Our study provides new insights into the previously unrecognized role of WWP1 in cardiomyocyte inflammation and progression of ischemic injury induced by MI. Our findings afford new therapeutic options for patients with ischemic cardiomyopathy.

miR-1322 protects against the myocardial ischemia via LRP8/PI3K/AKT pathway

INTRODUCTION

Myocardial infarction is a fatal disease that causes millions of deaths worldwide every year. The damage and recovery of cardiomyocytes are closely related to changes in gene expression. miRNA may be a new therapeutic target of myocardial ischemia-reperfusion.

METHODS

The differential expression genes were analyzed based on GSE83500, GSE60993 and GSE154733. miRNA expression profile data and clinical data were downloaded from GSE76591. Bioinformatics analysis including limma package, cluster analysis, WGCNA analysis were performed. H9c2 cell hypoxia model and mouse myocardial ischemia model were established. Q-PCR, Western blot and luciferase assay were carried out.

RESULTS

miR-1322 was identified as a significantly differentially expressed miRNA in myocardial ischemi. Yin Yang 1(YY1) was significantly highly expressed in cells with hypoxia treatment (P < 0.05), and myocardial ischemia mice (P < 0.01), which was identified as the transcription factor of miR-1322. The protein expression of LRP8 was lower in cells with hypoxia treatment and myocardial ischemia mice (P < 0.05) and LRP8 was the target gene of miR-1322. The overexpression of LRP8 could significantly increase the expression of p-PI3K, p-AKT, and P70 S6K (P < 0.05). LRP8 regulated PI3K/AKT/P70 S6K signaling pathway, eventually resulting in cell apoptosis.

CONCLUSION

Our results suggested that miR-1322 can protect against the myocardial ischemia via LRP8/PI3K/AKT pathway.

A novel peptide HSP-17 ameliorates oxidative stress injury and apoptosis in H9c2 cardiomyocytes by activating the PI3K/Akt pathway

Background

Oxidative stress and cell apoptosis play pivotal roles in the pathogenesis of doxorubicin (DOX)-induced myocardial injury. Heat shock protein-derived peptide (HSP-17) is a peptide which is low-expressed in DOX treated mouse heart tissue. It has high bioactivity and interspecies sequence consistency, and is predicted to have myocardial protective effect.

Methods

Firstly, we added 1 µM DOX to H9c2 cell culture medium for 24 hours to construct the myocardial cytotoxicity model. Then we detected the effect of HSP-17 on DOX induced H9c2 cardiomyocyte injury by measuring cell viability and lactate dehydrogenase (LDH) level. In addition, reactive oxygen species (ROS) and tetraethylbenzimidazolylcarbocyanine iodide kits are used to evaluate the effect of the HSP-17 peptide on DOX-induced oxidative stress injury to cardiomyocytes, and the detection of apoptosis related proteins and flow cytometry were applied to detect the level of apoptosis. Furthermore, the protein expression levels [phosphorylated Akt (p-Akt) and phosphorylated PI3K (p-PI3K)] of the PI3K/Akt pathway were also detected by western blotting.

Results

We found that the HSP-17 peptide can increase cell viability, protect mitochondrial potential, reduce LDH levels, and reduce ROS and cardiomyocyte apoptosis. In addition, we also observed that HSP-17 upregulated the expression level of p-Akt, and LY294002, a typical inhibitor of PI3K/Akt, was found to eliminate the protective roles of HSP-17.

Conclusions

In conclusion, this study demonstrated that the HSP-17 peptide protected H9c2 cells against oxidative stress and apoptosis via PI3K/Akt pathway activation, which provides a new idea for the treatment of DOX-induced myocardial injury.

PI3K signalling at the intersection of cardio-oncology networks: cardiac safety in the era of AI

Class I phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases. They are super elevated in many human cancer types and exert their main cellular functions by activating Akt to trigger an array of distinct responses, affecting metabolism and cell polarity. The signal equally plays important roles in cardiovascular pathophysiology. PI3K is required for cardiogenesis and regulation of cardiac structure and function. Overexpression of PI3K governs the development of cardiac pressure overload adaptation and compensatory hypertrophy. Therefore, inhibition of PI3K shortens life span, enhances cardiac dysfunction and pathological hypertrophy. The inverse inhibition effect, however, desirably destroys many cancer cells by blocking several aspects of the tumorigenesis phenotype. Given the contrasting effects in cardio-oncology; the best therapeutic strategy to target PI3K in cancer, while maintaining or rather increasing cardiac safety is under intense investigational scrutiny. To improve our molecular understanding towards identifying cardiac safety signalling of PI3K and/or better therapeutic strategy for cancer treatment, this article reviews PI3K signalling in cardio-oncology. PI3K signalling at the interface of metabolism, inflammation and immunity, and autonomic innervation networks were examined. Examples were then given of cardiovascular drugs that target the networks, being repurposed for cancer treatment. This was followed by an intersection scheme of the networks that can be functionalised with machine learning for safety and risk prediction, diagnoses, and defining new novel encouraging leads and targets for clinical translation. This will hopefully overcome the challenges of the one-signalling-one-health-outcome alliance, and expand our knowledge of the totality of PI3K signalling in cardio-oncology.

Ibrutinib Prevents Acute Lung Injury via Multi-Targeting BTK, FLT3 and EGFR in Mice

Ibrutinib has potential therapeutic or protective effects against viral- and bacterial-induced acute lung injury (ALI), likely by modulating the Bruton tyrosine kinase (BTK) signaling pathway. However, ibrutinib has multi-target effects. Moreover, immunity and inflammation targets in ALI treatment are poorly defined. We investigated whether the BTK-, FLT3-, and EGFR-related signaling pathways mediated the protective effects of ibrutinib on ALI. The intratracheal administration of poly I:C or LPS after ibrutinib administration in mice was performed by gavage. The pathological conditions of the lungs were assessed by micro-CT and HE staining. The levels of neutrophils, lymphocytes, and related inflammatory factors in the lungs were evaluated by ELISA, flow cytometry, immunohistochemistry, and immunofluorescence. Finally, the expression of proteins associated with the BTK-, FLT3-, and EGFR-related signaling pathways were evaluated by Western blotting. Ibrutinib (10 mg/kg) protected against poly I:C-induced (5 mg/kg) and LPS-induced (5 mg/kg) lung inflammation. The wet/dry weight ratio (W/D) and total proteins in the bronchoalveolar lavage fluid (BALF) were markedly reduced after ibrutinib (10 mg/kg) treatment, relative to the poly I:C- and LPS-treated groups. The levels of ALI indicators (NFκB, IL-1β, IL-6, TNF-α, IFN-γ, neutrophils, and lymphocytes) were significantly reduced after treatment. Accordingly, ibrutinib inhibited the poly I:C- and LPS-induced BTK-, FLT3-, and EGFR-related pathway activations. Ibrutinib inhibited poly I:C- and LPS-induced acute lung injury, and this may be due to its ability to suppress the BTK-, FLT3-, and EGFR-related signaling pathways. Therefore, ibrutinib is a potential protective agent for regulating immunity and inflammation in poly I:C- and LPS-induced ALI.

Gaseous signal molecule SO2 regulates autophagy through PI3K/AKT pathway inhibits cardiomyocyte apoptosis and improves myocardial fibrosis in rats with type II diabetes

Myocardial fibrosis is a key link in the occurrence and development of diabetic cardiomyopathy. Its etiology is complex, and the effect of drugs is not good. Cardiomyocyte apoptosis is an important cause of myocardial fibrosis. The purpose of this study was to investigate the effect of gaseous signal molecule sulfur dioxide (SO₂) on diabetic myocardial fibrosis and its internal regulatory mechanism. Masson and TUNEL staining, Western-blot, transmission electron microscopy, RT-qPCR, immunofluorescence staining, and flow cytometry were used in the study, and the interstitial collagen deposition, autophagy, apoptosis, and changes in phosphatidylinositol 3-kinase (PI3K)/AKT pathways were evaluated from in vivo and in vitro experiments. The results showed that diabetic myocardial fibrosis was accompanied by cardiomyocyte apoptosis and down-regulation of endogenous SO₂-producing enzyme aspartate aminotransferase (AAT)_1/2. However, exogenous SO₂ donors could up-regulate AAT1/2, reduce apoptosis of cardiomyocytes induced by diabetic rats or high glucose, inhibit phosphorylation of PI3K/AKT protein, up-regulate autophagy, and reduce interstitial collagen deposition. In conclusion, the results of this study suggest that the gaseous signal molecule SO₂ can inhibit the PI3K/AKT pathway to promote cytoprotective autophagy and inhibit cardiomyocyte apoptosis to improve myocardial fibrosis in diabetic rats. The results of this study are expected to provide new targets and intervention strategies for the prevention and treatment of diabetic cardiomyopathy.

Sodium danshensu attenuates cerebral ischemia–reperfusion injury by targeting AKT1

The beneficial properties of Sodium Danshensu (SDSS) for controlling cerebral ischemia and reperfusion injury (CIRI) are elucidated here both in vivo and in vitro. SDSS administration significantly improved the viability of P12 cells, reduced lactate dehydrogenase (LDH) leakage, and decreased the apoptosis rate following exposure to an oxygen-glucose deprivation/reoxygenation (OGD) environment. In addition, the results of a Huprot^TM human protein microarray and network pharmacology indicated that AKT1 is one of the main targets of SDSS. Moreover, functional experiments showed that SDSS intervention markedly increased the phosphorylation level of AKT1 and its downstream regulator, mTOR. The binding sites of SDSS to AKT1 protein were confirmed by Autodock software and a surface plasmon resonance experiment, the result of which imply that SDSS targets to the PH domain of AKT1 at ASN-53, ARG-86, and LYS-14 residues. Furthermore, knockdown of AKT1 significantly abolished the role of SDSS in protecting cells from apoptosis and necrosis. Finally, we investigated the curative effect of SDSS in a rat model of CIRI. The results suggest that administration of SDSS significantly reduces CIRI-induced necrosis and apoptosis in brain samples by activating AKT1 protein. In conclusion, SDSS exerts its positive role in alleviating CIRI by binding to the PH domain of AKT1 protein, further resulting in AKT1 activation.

Salidroside Inhibits Ischemia/Reperfusion-Induced Myocardial Apoptosis by Targeting Mir-378a-3p Via the Igf1r/Pi3k/Akt Signaling Pathway

BACKGROUND

The present study aimed to investigate the protective effects and mechanism of salidroside (SAL) on hypoxia/reoxygenation (H/R)-induced cardiomyocyte apoptosis and myocardial ischemia/reperfusion (I/R) injury.

METHODS

We set up an H/R H9c2 cell model in vitro and an I/R rat model in vivo. Cell viability, apoptosis and histopathologic evaluation were conducted.

RESULTS

The cell viability of H/R-induced cardiomyocytes was increased by pretreatment of SAL, whereas the release of lactate dehydrogenase, reactive oxygen species production, and apoptosis were decreased accompanied with reduced Cleaved-caspase-3 and Bax, and increased Bcl-2 expressions. The SAL restored mitochondrial membrane potential both in vitro and in vivo, and improved electrocardiographic abnormality, and attenuated myocardial apoptosis and injury in I/R-induced rats. The transfection of miR-378a-3p inhibitor counteracted the effects of SAL-induced increase of cell viability and decrease of cell apoptosis and mitochondrial membrane potential. SAL reduced the expression of insulin-like growth factor 1 receptor (IGF1R), and increased the expressions of PI3K and Akt, however, these alterations were blocked by miR-378a-3p inhibitor.

CONCLUSIONS

miR-378a-3p might participate in the protective effect of SAL in I/R-induced myocardial apoptosis via the IGF1R/PI3K/AKT signaling pathway.

Toll-Like Receptor 3 in Cardiovascular Diseases

Toll-like receptor 3 (TLR3) is an important member of the innate immune response receptor toll-like receptors (TLRs) family, which plays a vital role in regulating immune response, promoting the maturation and differentiation of immune cells, and participating in the response of pro-inflammatory factors. TLR3 is activated by pathogen-associated molecular patterns and damage-associated molecular patterns, which support the pathophysiology of many diseases related to inflammation. An increasing number of studies have confirmed that TLR3, as a crucial medium of innate immunity, participates in the occurrence and development of cardiovascular diseases (CVDs) by regulating the transcription and translation of various cytokines, thus affecting the structure and physiological function of resident cells in the cardiovascular system, including vascular endothelial cells, vascular smooth muscle cells, cardiomyocytes, fibroblasts and macrophages. The dysfunction and structural damage of vascular endothelial cells and proliferation of vascular smooth muscle cells are the key factors in the occurrence of vascular diseases such as pulmonary arterial hypertension, atherosclerosis, myocardial hypertrophy, myocardial infarction, ischaemia/reperfusion injury, and heart failure. Meanwhile, cardiomyocytes, fibroblasts, and macrophages are involved in the development of CVDs. Therefore, the purpose of this review was to explore the latest research published on TLR3 in CVDs and discuss current understanding of potential mechanisms by which TLR3 contributes to CVDs. Even though TLR3 is a developing area, it has strong treatment potential as an immunomodulator and deserves further study for clinical translation.

Design, Synthesis, and Biological Evaluation of N14-Amino Acid-Substituted Tetrandrine Derivatives as Potential Antitumor Agents against Human Colorectal Cancer

As a typical dibenzylisoquinoline alkaloid, tetrandrine (TET) is clinically used for the treatment of silicosis, inflammatory pulmonary, and cardiovascular diseases in China. Recent investigations have demonstrated the outstanding anticancer activity of this structure, but its poor aqueous solubility severely restricts its further development. Herein, a series of its 14-N-amino acid-substituted derivatives with improved anticancer effects and aqueous solubility were designed and synthesized. Among them, compound 16 displayed the best antiproliferative activity against human colorectal cancer (HCT-15) cells, with an IC50 value of 0.57 μM. Compared with TET, 16 was markedly improved in terms of aqueous solubility (by 5-fold). Compound 16 significantly suppressed the colony formation, migration, and invasion of HCT-15 cells in a concentration-dependent manner, with it being more potent in this respect than TET. Additionally, compound 16 markedly impaired the morphology and motility of HCT-15 cells and induced the death of colorectal cancer cells in double-staining and flow cytometry assays. Western blot results revealed that 16 could induce the autophagy of HCT-15 cells by significantly decreasing the content of p62/SQSTM1 and enhancing the Beclin-1 level and the ratio of LC3-II to LC3-I. Further study showed that 16 effectively inhibited the proliferation, migration, and tube formation of umbilical vein endothelial cells, manifesting in a potent anti-angiogenesis effect. Overall, these results revealed the potential of 16 as a promising candidate for further preclinical studies.

Tetramethylpyrazine: A review on its mechanisms and functions

Ligusticum chuanxiong Hort (known as Chuanxiong in China, CX) is one of the most widely used and long-standing medicinal herbs in China. Tetramethylpyrazine (TMP) is an alkaloid and one of the active components of CX. Over the past few decades, TMP has been proven to possess several pharmacological properties. It has been used to treat a variety of diseases with excellent therapeutic effects. Here, the pharmacological characteristics and molecular mechanism of TMP in recent years are reviewed, with an emphasis on the signal-regulation mechanism of TMP. This review shows that TMP has many physiological functions, including anti-oxidant, anti-inflammatory, and anti-apoptosis properties; autophagy regulation; vasodilation; angiogenesis regulation; mitochondrial damage suppression; endothelial protection; reduction of proliferation and migration of vascular smooth muscle cells; and neuroprotection. At present, TMP is used in treating cardiovascular, nervous, and digestive system conditions, cancer, and other conditions and has achieved good curative effects. The therapeutic mechanism of TMP involves multiple targets, multiple pathways, and bidirectional regulation. TMP is, thus, a promising drug with great research potential.

Sufentanil ameliorates oxygen‑glucose deprivation/reoxygenation‑induced endothelial barrier dysfunction in HCMECs via the PI3K/Akt signaling pathway

Ischemic heart disease, a chronic myocardial damage disease caused by coronary artery ischemia, is the leading cause of death worldwide. The aim of the present study was to explore the efficacy of sufentanil in myocardial ischemia/reperfusion (I/R) injury. Oxygen and glucose deprivation/reoxygenation (OGD/R) was utilized to induce human cardiac microvascular endothelial cells (HCMECs) to simulate myocardial I/R injury in vitro. The Cell Counting Kit-8 assay was used to detect the effects of sufentanil on HCMECs and OGD/R-induced HCMECs. The TUNEL, lactate dehydrogenase (LDH) activity, immunofluorescence and in vitro permeability assays, were used to assess apoptosis, LDH activity, VE-cadherin protein expression levels and endothelial barrier function in OGD/R-induced HCMECs, respectively. Moreover, western blotting was performed to assess the protein expression levels of apoptosis, endothelial barrier function and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)-related proteins. The results demonstrated that sufentanil had no significant influence on the viability of HCMECs but increased the viability of OGD/R-induced HCMECs in a dose-dependent manner. Furthermore, sufentanil inhibited cell apoptosis and permeability of OGD/R-induced HCMECs but enhanced the protein expression levels of tight junction proteins, including ZO-1, Occludin, VE-cadherin and Claudin-5. Sufentanil was also demonstrated to activate the PI3K/Akt signaling pathway. In addition, the use of LY294002, an inhibitor of the PI3K/Akt signaling pathway, partially abolished the protective effects of sufentanil on apoptosis, permeability and tight junction protein expression levels. These results indicated that sufentanil ameliorated OGD/R-induced endothelial barrier dysfunction in HCMECs, potentially via the PI3K/Akt signaling pathway. The present study therefore suggested that sufentanil may serve as a novel therapeutic option for the improvement of myocardial I/R injury.

Urolithin A Inactivation of TLR3/TRIF Signaling to Block the NF-κB/STAT1 Axis Reduces Inflammation and Enhances Antioxidant Defense in Poly(I:C)-Induced RAW264.7 Cells

Urolithin A is an active compound of gut-microbiota-derived metabolites of polyphenol ellagic acid that has anti-aging, antioxidative, and anti-inflammatory effects. However, the effects of urolithin A on polyinosinic acid-polycytidylic acid (poly(I:C))-induced inflammation remain unclear. Poly(I:C) is a double-stranded RNA (dsRNA) similar to a virus and is recognized by Toll-like receptor-3 (TLR3), inducing an inflammatory response in immune cells, such as macrophages. Inflammation is a natural defense process of the innate immune system. Therefore, we used poly(I:C)-induced RAW264.7 cells and attenuated the inflammation induced by urolithin A. First, our data suggested that 1–30 μM urolithin A does not reduce RAW264.7 cell viability, whereas 1 μM urolithin A is sufficient for antioxidation and the decreased production of tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and C-C chemokine ligand 5. The inflammation-related proteins cyclooxygenase-2 and inducible nitric oxide synthase were also downregulated by urolithin A. Next, 1 μM urolithin A inhibited the levels of interferon (INF)-α and INF-β. Urolithin A was applied to investigate the blockade of the TLR3 signaling pathway in poly(I:C)-induced RAW264.7 cells. Moreover, the TLR3 signaling pathway, subsequent inflammatory-related pathways, and antioxidation pathways showed changes in nuclear factor-κB (NF-κB) signaling and blocked ERK/mitogen-activated protein kinase (MAPK) signaling. Urolithin A enhanced catalase (CAT) and superoxide dismutase (SOD) activities, but decreased malondialdehyde (MDA) levels in poly(I:C)-induced RAW264.7 cells. Thus, our results suggest that urolithin A inhibits TLR3-activated inflammatory and oxidative-associated pathways in macrophages, and that this inhibition is induced by poly(I:C). Therefore, urolithin A may have antiviral effects and could be used to treat viral-infection-related diseases.

Poly(I:C) attenuates myocardial ischemia/reperfusion injury by restoring autophagic function

Polyinosinic-polycytidylic acid (poly(I:C)) is the agonist of Toll-like receptor 3 (TLR3), which participates in innate immune responses under the condition of myocardial ischemia/reperfusion injury (MIRI). It has been shown that poly(I:C) exhibited cardioprotective activities through the PI3K/Akt pathway, which is the main signal transduction pathway during autophagy. However, the precise mechanism by whether poly(I:C) regulates autophagy remains poorly understood. Thus, this study was designed to investigate the therapeutic effect of poly(I:C) against MIRI and the underlying pathway connection with autophagy. We demonstrated that 1.25 and 5 mg/kg poly(I:C) preconditioning significantly reduced myocardial infarct size and cardiac dysfunction. Moreover, poly(I:C) significantly promoted cell survival by restoring autophagy flux and then regulating it to an adequate level Increased autophagy protein Beclin1 and LC3II together with p62 degradation after additional chloroquine. In addition, mRFP-GFP-LC3 adenoviruses exhibited autophagy activity in neonatal rat cardiac myocytes (NRCMs). Mechanistically, poly(I:C) activated the PI3K/AKT/mTOR pathway to induce autophagy, which was abolished by LY294002 (PI3K antagonist), rapamycin (autophagy activator and mTOR inhibitor), or 3-methyladenine (autophagy inhibitor), suggesting either inhibition of the PI3K/Akt/mTOR pathway or autophagy activity interrupt the beneficial effect of poly(I:C) preconditioning. In conclusion, poly(I:C) promotes cardiomyocyte survival from ischemia/reperfusion injury by regulating autophagy via the PI3K/Akt/mTOR pathway.

Role and mechanism of the lncRNA SNHG1/miR‑450b‑5p/IGF1 axis in the regulation of myocardial ischemia reperfusion injury

The increasing rates of morbidity and mortality caused by ischemic heart disease pose a serious threat to human health. Long non‑coding (lnc)RNA small nucleolar RNA host gene 1 (SNHG1) has a protective effect on the myocardium. In the present study, the role of lncRNA SNHG1 in myocardial ischemia reperfusion injury (MIRI) and the underlying mechanisms were investigated. After hypoxia/reoxygenation (H/R) induction, the expression levels of lncRNA SNHG1 were detected using reverse transcription‑quantitative PCR. After lncRNA SNHG1 overexpression via cell transfection, cell viability was detected using an MTT assay, apoptotic rates were detected using TUNEL staining, apoptosis‑related protein expression levels were detected using western blotting and respective kits were used to measure the oxidative stress levels. The Encyclopedia of RNA Interactomes database predicted the presence of binding sites between lncRNA SNHG1 and microRNA (miR)‑450b‑5p, and between miR‑450b‑5p and insulin‑like growth factor 1 (IGF1). These interactions were then verified using luciferase reporter assays. Subsequently, the regulatory mechanism underlying the lncRNA SNHG1/miR‑450b‑5p/IGF1 axis in MIRI was investigated by overexpressing miR‑450b‑5p and knocking down IGF1 expression in H/R‑induced cells. Finally, the expression of PI3K/Akt signaling pathway‑related proteins was detected using western blotting. lncRNA SNHG1 expression was significantly downregulated in H/R‑induced AC16 cells. lncRNA SNHG1 overexpression significantly inhibited apoptosis and decreased oxidative stress levels in H/R‑induced AC16 cells, which was mediated via regulation of the miR‑450b‑5p/IGF1 axis and activation of the PI3K/Akt signaling pathway. Therefore, the present study suggested that activation of the PI3K/Akt signaling pathway via the lncRNA SNHG1/miR‑450b‑5p/IGF1 axis inhibited the apoptosis and oxidative stress levels of H/R‑induced AC16 cells.

Primary Cilium by Polyinosinic:Polycytidylic Acid Regulates the Regenerative Migration of Beas-2B Bronchial Epithelial Cells

The airway epithelium is equipped with the ability to resist respiratory disease development and airway damage, including the migration of airway epithelial cells and the activation of TLR3, which recognizes double-stranded (ds) RNA. Primary cilia on airway epithelial cells are involved in the cell cycle and cell differentiation and repair. In this study, we used Beas-2B human bronchial epithelial cells to investigate the effects of the TLR3 agonist polyinosinic:polycytidylic acid [Poly(I:C)] on airway cell migration and primary cilia (PC) formation. PC formation increased in cells incubated under serum deprivation. Migration was faster in Beas-2B cells pretreated with Poly(I:C) than in control cells, as judged by a wound healing assay, single-cell path tracking, and a Transwell migration assay. No changes in cell migration were observed when the cells were incubated in conditioned medium from Poly(I:C)-treated cells. PC formation was enhanced by Poly(I:C) treatment, but was reduced when the cells were exposed to the ciliogenesis inhibitor ciliobrevin A (CilioA). The inhibition of Beas-2B cell migration by CilioA was also assessed and a slight decrease in ciliogenesis was detected in SARS-CoV-2 spike protein (SP)-treated Beas-2B cells overexpressing ACE2 compared to control cells. Cell migration was decreased by SP but restored by Poly(I:C) treatment. Taken together, our results demonstrate that impaired migration by SP-treated cells can be attenuated by Poly(I:C) treatment, thus increasing airway cell migration through the regulation of ciliogenesis.

Calenduloside E protects against myocardial ischemia-reperfusion injury induced calcium overload by enhancing autophagy and inhibiting L-type Ca2+ channels through BAG3

Calenduloside E (CE) is a saponin isolated from Aralia elata (Miq) Seem, which has anti-cardiovascular disease effects. This study aims to evaluate the anti-myocardial ischemia-reperfusion injury (MIRI) mechanisms of CE and regulation of BAG3 on calcium overload. We adopted siRNA to interfere with BAG3 expression in H9c2 cardiomyocytes and used adenovirus to interfere with BAG3 expression (Ad-BAG3) in primary neonatal rat cardiomyocytes (PNRCMs) to clarify the role of BAG3 in mitigating MIRI by CE. The results showed that CE reduced calcium overload, and Ad-BAG3 had a significant regulatory effect on L-type Ca²⁺ channels (LTCC) but no effects on other calcium-related proteins. And BAG3 and LTCC were colocalized in myocardial tissue and BAG3 inhibited LTCC expression. Surprisingly, CE had no regulatory effect on LTCC mRNA, but CE promoted LTCC degradation through the autophagy-lysosomal pathway rather than the ubiquitination-protease pathway. Autophagy inhibitor played a negative regulation of cardiomyocyte contraction rhythm and field potential signals. Ad-BAG3 inhibited autophagy by regulating the expression of autophagy-related proteins and autophagy agonist treatment suppressed calcium overload. Therefore, CE promoted autophagy through BAG3, thereby regulating LTCC expression, inhibiting calcium overload, and ultimately reducing MIRI.

Discovery of β-Carboline Derivatives as a Highly Potent Cardioprotectant against Myocardial Ischemia-Reperfusion Injury

Timely myocardial reperfusion salvages ischemic myocardium from infarction, whereas reperfusion itself induces cardiomyocyte death, which is called myocardial ischemia/reperfusion (MI/R) injury. Herein, β-carboline derivative 17c was designed and synthesized with obvious myocardial protective activity for the first time. Pretreatment of 17c effectively protected the cardiomyocyte H9c2 cells from H₂O₂-induced lactate dehydrogenase leakage and restored the endogenous antioxidants, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Besides, 17c effectively protected the mitochondria through decreasing the reactive oxygen species overproduction and enhancing the mitochondrial membrane potential. As a result, 17c significantly reduced the necrosis of cardiomyocytes in H₂O₂-induced oxidative stress, which was more potent than polydatin. In MI/R injury rats, 17c pretreatment obviously increased the levels of SOD and GSH-Px and inhibited the apoptosis of cardiomyocytes. Through this way, the size of myocardial infarction was significantly reduced after MI/R injury in vivo, better than that of polydatin, suggesting that 17c is a promising cardioprotectant for the prevention of MI/R injury.

Novel Insight into the Role of Endoplasmic Reticulum Stress in the Pathogenesis of Myocardial Ischemia-Reperfusion Injury

Impaired function of the endoplasmic reticulum (ER) is followed by evolutionarily conserved cell stress responses, which are employed by cells, including cardiomyocytes, to maintain and/or restore ER homeostasis. ER stress activates the unfolded protein response (UPR) to degrade and remove abnormal proteins from the ER lumen. Although the UPR is an intracellular defense mechanism to sustain cardiomyocyte viability and heart function, excessive activation initiates ER-dependent cardiomyocyte apoptosis. Myocardial ischemia/reperfusion (I/R) injury is a pathological process occurring during or after revascularization of ischemic myocardium. Several molecular mechanisms contribute to the pathogenesis of cardiac I/R injury. Due to the dual protective/degradative effects of ER stress on cardiomyocyte viability and function, it is of interest to understand the basic concepts, regulatory signals, and molecular processes involved in ER stress following myocardial I/R injury. In this review, therefore, we present recent findings related to the novel components of ER stress activation. The complex effects of ER stress and whether they mitigate or exacerbate myocardial I/R injury are summarized to serve as the basis for research into potential therapies for cardioprotection through control of ER homeostasis.

Mitochondria and Pharmacologic Cardiac Conditioning-At the Heart of Ischemic Injury

Pharmacologic cardiac conditioning increases the intrinsic resistance against ischemia and reperfusion (I/R) injury. The cardiac conditioning response is mediated via complex signaling networks. These networks have been an intriguing research field for decades, largely advancing our knowledge on cardiac signaling beyond the conditioning response. The centerpieces of this system are the mitochondria, a dynamic organelle, almost acting as a cell within the cell. Mitochondria comprise a plethora of functions at the crossroads of cell death or survival. These include the maintenance of aerobic ATP production and redox signaling, closely entwined with mitochondrial calcium handling and mitochondrial permeability transition. Moreover, mitochondria host pathways of programmed cell death impact the inflammatory response and contain their own mechanisms of fusion and fission (division). These act as quality control mechanisms in cellular ageing, release of pro-apoptotic factors and mitophagy. Furthermore, recently identified mechanisms of mitochondrial regeneration can increase the capacity for oxidative phosphorylation, decrease oxidative stress and might help to beneficially impact myocardial remodeling, as well as invigorate the heart against subsequent ischemic insults. The current review highlights different pathways and unresolved questions surrounding mitochondria in myocardial I/R injury and pharmacological cardiac conditioning.