Matrine attenuates pathological cardiac fibrosis via RPS5/p38 in mice

Aged gut microbiota promotes arrhythmia susceptibility via oxidative stress

Arrhythmias and sudden cardiac death (SCD) impose a significant burden. Their prevalence rises with age and is linked to gut dysbiosis. Our study aimed to determine whether aged gut microbiota affects arrhythmogenesis. Here, we demonstrated that arrhythmia susceptibility in aged mice could be transmitted to young mice using fecal microbiota transplantation (FMT). Mechanistically, increased intestinal reactive oxygen species (ROS) in aged mice reduced ion channel protein expression and promoted arrhythmias. Gut microbiota depletion by an antibiotic cocktail reduced ROS and arrhythmia in aged mice. Interestingly, oxidative stress in heart induced by hydrogen peroxide (H2O2) increased arrhythmia. Moreover, aged gut microbiota could induce oxidative stress in young mice colon by gut microbiota metabolites transplantation. Vitexin could reduce aging and arrhythmia through OLA1-Nrf2 signaling pathway. Overall, our study demonstrated that the gut microbiota of aged mice reduced cardiac ion channel protein expression through systemic oxidative stress, thereby increased the risk of arrhythmias.

Research Progress on the Mechanism, Monitoring, and Prevention of Cardiac Injury Caused by Antineoplastic Drugs-Anthracyclines

Anthracyclines represent a highly efficacious class of chemotherapeutic agents employed extensively in antitumor therapy. They are universally recognized for their potency in treating diverse malignancies, encompassing breast cancer, gastrointestinal tumors, and lymphomas. Nevertheless, the accumulation of anthracyclines within the body can lead to significant cardiac toxicity, adversely impacting both the survival rates and quality of life for tumor patients. This limitation somewhat restricts their clinical utilization. Determining how to monitor and mitigate their cardiotoxicity at an early stage has become an urgent clinical problem to be solved. Therefore, this paper reviews the mechanism of action, early monitoring, and strategies for the prevention of anthracycline-induced cardiotoxicity for clinical reference.

Leucine zipper protein 1 attenuates pressure overload-induced cardiac hypertrophy through inhibiting Stat3 signaling

INTRODUCTION

Cardiac hypertrophy is an important contributor of heart failure, and the mechanisms remain unclear. Leucine zipper protein 1 (LUZP1) is essential for the development and function of cardiovascular system; however, its role in cardiac hypertrophy is elusive.

OBJECTIVES

This study aims to investigate the molecular basis of LUZP1 in cardiac hypertrophy and to provide a rational therapeutic approach.

METHODS

Cardiac-specific Luzp1 knockout (cKO) and transgenic mice were established, and transverse aortic constriction (TAC) was used to induce pressure overload-induced cardiac hypertrophy. The possible molecular basis of LUZP1 in regulating cardiac hypertrophy was determined by transcriptome analysis. Neonatal rat cardiomyocytes were cultured to elucidate the role and mechanism of LUZP1 in vitro.

RESULTS

LUZP1 expression was progressively increased in hypertrophic hearts after TAC surgery. Gain- and loss-of-function methods revealed that cardiac-specific LUZP1 deficiency aggravated, while cardiac-specific LUZP1 overexpression attenuated pressure overload-elicited hypertrophic growth and cardiac dysfunction in vivo and in vitro. Mechanistically, the transcriptome data identified Stat3 pathway as a key downstream target of LUZP1 in regulating pathological cardiac hypertrophy. Cardiac-specific Stat3 deletion abolished the pro-hypertrophic role in LUZP1 cKO mice after TAC surgery. Further findings suggested that LUZP1 elevated the expression of Src homology region 2 domain-containing phosphatase 1 (SHP1) to inactivate Stat3 pathway, and SHP1 silence blocked the anti-hypertrophic effects of LUZP1 in vivo and in vitro.

CONCLUSION

We demonstrate that LUZP1 attenuates pressure overload-induced cardiac hypertrophy through inhibiting Stat3 signaling, and targeting LUZP1 may develop novel approaches to treat pathological cardiac hypertrophy.

LDHA contributes to nicotine induced cardiac fibrosis through autophagy flux impairment

Cardiac fibrosis is a typical feature of cardiac pathological remodeling, which is associated with adverse clinical outcomes and has no effective therapy. Nicotine is an important risk factor for cardiac fibrosis, yet its underlying molecular mechanism remains poorly understood. This study aimed to identify its potential molecular mechanism in nicotine-induced cardiac fibrosis. Our results showed nicotine exposure led to the proliferation and transformation of cardiac fibroblasts (CFs) into myofibroblasts (MFs) by impairing autophagy flux. Through the use of drug affinity responsive target stability (DARTS) assay, cellular thermal shift assay (CETSA), and surface plasmon resonance (SPR) technology, it was discovered that nicotine directly increased the stability and protein levels of lactate dehydrogenase A (LDHA) by binding to it. Nicotine treatment impaired autophagy flux by regulating the AMPK/mTOR signaling pathway, impeding the nuclear translocation of transcription factor EB (TFEB), and reducing the activity of cathepsin B (CTSB). In vivo, nicotine treatment exacerbated cardiac fibrosis induced in spontaneously hypertensive rats (SHR) and worsened cardiac function. Interestingly, the absence of LDHA reversed these effects both in vitro and in vivo. Our study identified LDHA as a novel nicotine-binding protein that plays a crucial role in mediating cardiac fibrosis by blocking autophagy flux. The findings suggest that LDHA could potentially serve as a promising target for the treatment of cardiac fibrosis.

The potential therapeutic value of the natural plant compounds matrine and oxymatrine in cardiovascular diseases

Matrine (MT) and Oxymatrine (OMT) are two natural alkaloids derived from plants. These bioactive compounds are notable for their diverse pharmacological effects and have been extensively studied and recognized in the treatment of cardiovascular diseases in recent years. The cardioprotective effects of MT and OMT involve multiple aspects, primarily including antioxidative stress, anti-inflammatory actions, anti-atherosclerosis, restoration of vascular function, and inhibition of cardiac remodeling and failure. Clinical pharmacology research has identified numerous novel molecular mechanisms of OMT and MT, such as JAK/STAT, Nrf2/HO-1, PI3 K/AKT, TGF-β1/Smad, and Notch pathways, providing new evidence supporting their promising therapeutic potential against cardiovascular diseases. Thus, this review aims to investigate the potential applications of MT and OMT in treating cardiovascular diseases, encompassing their mechanisms, efficacy, and safety, confirming their promise as lead compounds in anti-cardiovascular disease drug development.

Natural Products for Preventing and Managing Anthracycline-Induced Cardiotoxicity: A Comprehensive Review

Doxorubicin (DOX) is an anthracycline anticancer agent that is highly effective in the treatment of solid tumors. Given the multiplicity of mechanisms involved in doxorubicin-induced cardiotoxicity, it is difficult to identify a precise molecular target for toxicity. The findings of a literature review suggest that natural products may offer cardioprotective benefits against doxorubicin-induced cardiotoxicity, both in vitro and in vivo. However, further confirmatory studies are required to substantiate this claim. It is of the utmost importance to direct greater attention towards the intricate signaling networks that are of paramount importance for the survival and dysfunction of cardiomyocytes. Notwithstanding encouraging progress made in preclinical studies of natural products for the prevention of DOX-induced cardiotoxicity, these have not yet been translated for clinical use. One of the most significant obstacles hindering the development of cardioprotective adjuvants based on natural products is the lack of adequate bioavailability in humans. This review presents an overview of current knowledge on doxorubicin DOX-induced cardiotoxicity, with a focus on the potential benefits of natural compounds and herbal preparations in preventing this adverse effect. As literature search engines, the browsers in the Scopus, PubMed, Web of Science databases and the ClinicalTrials.gov register were used.

SFTPB in serum extracellular vesicles as a biomarker of progressive pulmonary fibrosis

Progressive pulmonary fibrosis (PPF), defined as the worsening of various interstitial lung diseases (ILDs), currently lacks useful biomarkers. To identify novel biomarkers for early detection of patients at risk of PPF, we performed a proteomic analysis of serum extracellular vesicles (EVs). Notably, the identified candidate biomarkers were enriched for lung-derived proteins participating in fibrosis-related pathways. Among them, pulmonary surfactant-associated protein B (SFTPB) in serum EVs could predict ILD progression better than the known biomarkers, serum KL-6 and SP-D, and it was identified as an independent prognostic factor from ILD-gender-age-physiology index. Subsequently, the utility of SFTPB for predicting ILD progression was evaluated further in 2 cohorts using serum EVs and serum, respectively, suggesting that SFTPB in serum EVs but not in serum was helpful. Among SFTPB forms, pro-SFTPB levels were increased in both serum EVs and lungs of patients with PPF compared with those of the control. Consistently, in a mouse model, the levels of pro-SFTPB, primarily originating from alveolar epithelial type 2 cells, were increased similarly in serum EVs and lungs, reflecting pro-fibrotic changes in the lungs, as supported by single-cell RNA sequencing. SFTPB, especially its pro-form, in serum EVs could serve as a biomarker for predicting ILD progression.

Lapatinib combined with doxorubicin causes dose-dependent cardiotoxicity partially through activating the p38MAPK signaling pathway in zebrafish embryos

Because of its enhanced antitumor efficacy, lapatinib (LAP) is commonly used clinically in combination with the anthracycline drug doxorubicin (DOX) to treat metastatic breast cancer. While it is well recognized that this combination chemotherapy can lead to an increased risk of cardiotoxicity in adult women, its potential cardiotoxicity in the fetus during pregnancy remains understudied. Here, we aimed to examine the combination of LAP chemotherapy and DOX-induced cardiotoxicity in the fetus using a zebrafish embryonic system and investigate the underlying pathologic mechanisms. First, we examined the dose-dependent cardiotoxicity of combined LAP and DOX exposure in zebrafish embryos, which mostly manifested as pericardial edema, bradycardia, cardiac function decline and reduced survival. Second, we revealed that a significant increase in oxidative stress concurrent with activated MAPK signaling, as indicated by increased protein expression of phosphorylated p38 and Jnk, was a notable pathophysiological event after combined LAP and DOX exposure. Third, we showed that inhibiting MAPK signaling by pharmacological treatment with the p38MAPK inhibitor SB203580 or genetic ablation of the map2k6 gene could significantly alleviate combined LAP and DOX exposure-induced cardiotoxicity. Thus, we provided both pharmacologic and genetic evidence to suggest that inhibiting MAPK signaling could exert cardioprotective effects. These findings have implications for understanding the potential cardiotoxicity induced by LAP and DOX combinational chemotherapy in the fetus during pregnancy, which could be leveraged for the development of new therapeutic strategies.

Follistatin-like 1 protects against doxorubicin-induced cardiotoxicity by preventing mitochondrial dysfunction through the SIRT6/Nrf2 signaling pathway

Mitochondrial dysfunction and myocardial remodeling have been reported to be the main underlying molecular mechanisms of doxorubicin-induced cardiotoxicity. SIRT6 is a nicotinamide adenine dinucleotide-dependent enzyme that plays a vital role in cardiac protection against various stresses. Moreover, previous studies have demonstrated that FSTL1 could alleviate doxorubicin-induced cardiotoxicity by inhibiting autophagy. The present study investigated the probable mechanisms of FSTL1 on doxorubicin-induced cardiotoxicity in vivo and in vitro. We confirmed that FSTL1 exerted a pivotal protective role on cardiac tissue in vivo and on doxorubicin-induced cell injury in vitro. Furthermore, FSTL1 can alleviate doxorubicin-induced mitochondrial dysfunction by inhibiting autophagy and apoptosis. Further studies demonstrated that FSTL1 can activate SIRT6 signaling by restoring the SIRT6 protein expression in doxorubicin-induced myocardial injury. SIRT6 activation elevated the protein expression of Nrf2 in doxorubicin-induced H9C2 injury. Treatment with the Nrf2 inhibitor ML385 partially antagonized the cardioprotective role of SIRT6 on doxorubicin-induced autophagy or apoptosis. These results suggested that the protective mechanism of FSTL1 on doxorubicin-induced cardiotoxicity may be related with the inhibition of autophagy and apoptosis, partly through the activation of SIRT6/Nrf2.

A multilocus-dendritic boronic acid functionalized magnetic nanoparticle for capturing circulating tumor cells in the peripheral blood of mice with metastatic breast cancer

BACKGROUND

Dynamic fluctuation of circulating tumor cells (CTCs) can serve as an indicator of tumor progression. However, the sensitive isolation of CTCs remains extremely challenging due to their rarity and heterogeneity. Against this dilemma, dendritic boronic acid-modified magnetic nanoparticles (MNPs) were prepared in this study, and polyethyleneimine (PEI) was utilized as a scaffold to significantly increase the number of boronic acid moieties. Then the novel developed material was applied to monitor the number of CTCs in mice with metastatic breast cancer to evaluate the therapeutic effects of matrine (Mat), doxorubicin (Dox), and Mat in combination with Dox.

RESULTS

Compared to the low binding capacity of a single boronic acid ligand, dendritic boronic acid shows enhanced sensitivity in binding to sialic acid (SA), which is overexpressed in CTCs. The results showed that the capture efficiency of this modified material could achieve 94.7% and successfully captured CTCs in blood samples from mice with metastatic breast cancer. The CTC counts were consistent with the results of the pathologic examination, demonstrating the reliability and utility of the method.

SIGNIFICANCE

The dendritic boronic acid nanomaterials prepared in this study showed high specificity, sensitivity, and accuracy for cancer cell capture. The approach is expected to provide new insights into cancer diagnosis, personalized therapy, and optimization of treatment regimens.

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

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

Irisin protects against cardiac injury by inhibiting NLRP3 inflammasome-mediated pyroptosis during remodeling after infarction

This study aimed to explore the cardioprotective mechanism of irisin in the context of cardiac injury. Utilizing a myocardial infarction (MI) mouse model, we investigated the therapeutic potential of recombinant human irisin (rhIrisin) administered for 28 days post-infarction. The efficacy of irisin treatment was evaluated through echocardiographic assessment of cardiac function and serum analysis of myocardial injury markers. Our research provided novel insights into the impacts of irisin on the NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome activation and pyroptosis, assessed both in vivo in MI mice and in vitro in hypoxia/reoxygenation-treated H9C2 cells. Remarkably, irisin treatment significantly reduced levels of lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), and troponin I, indicating reduced myocardial injury. Echocardiography highlighted substantial improvements in left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), and dimensions (LVIDd and LVIDs) in irisin-treated mice, underscoring enhanced cardiac function. Moreover, irisin was shown to significantly suppress the mRNA and protein expressions of key components involved in NLRP3 inflammasome pathway (NLRP3, ASC, caspase-1 (p20), and interleukin-18 (IL-18)) both in MI-induced mice and hypoxia/reoxygenation-treated cells. This study firstly reveals that the cardioprotective effect of irisin is mediated through the attenuation of NLRP3 inflammasome activation and pyroptosis, positioning irisin as a promising therapeutic agent for cardiac injury.

FLRT2 suppresses bladder cancer progression through inducing ferroptosis

Bladder cancer is a common tumour worldwide and exhibits a poor prognosis. Fibronectin leucine rich transmembrane protein 2 (FLRT2) is associated with the regulation of multiple tumours; however, its function in human bladder cancer remain unclear. Herein, we found that FLRT2 level was reduced in human bladder cancer and that higher FLRT2 level predicted lower survival rate. FLRT2 overexpression inhibited, while FLRT2 silence facilitated tumour cell growth, migration and invasion. Mechanistic studies revealed that FLRT2 elevated acyl-CoA synthetase long-chain family member 4 (ACSL4) expression, increased lipid peroxidation and subsequently facilitated ferroptosis of human bladder cancer cells. In summary, we demonstrate that FLRT2 elevates ACSL4 expression to facilitate lipid peroxidation and subsequently triggers ferroptosis, thereby inhibiting the malignant phenotype of human bladder cancer cells. Overall, we identify FLRT2 as a tumour suppressor gene.

CYP2J2-derived epoxyeicosatrienoic acids protect against doxorubicin-induced cardiotoxicity by reducing oxidative stress and apoptosis via activation of the AMPK pathway

Objective

Despite the widespread use of doxorubicin (DOX) in chemotherapy, it can cause cardiotoxicity, which severely limits its potential clinical use. CYP2J2-derived epoxyeicosatrienoic acids (EETs) exert cardioprotective effects by maintaining cardiac homeostasis. The roles and latent mechanisms of EETs in DOX cardiotoxicity remain uncertain. We investigated these aspects using mouse tissue and cell culture models.

Methods

C57BL/6J mice were injected with rAAV9-CYP2J2 or a control vector via the caudal vein. A five-week intraperitoneal course of DOX (5 mg/kg per week) was administered. After pretreatment with 14,15-EET, H9C2 cells were treated for 24-h with DOX, to use as a cell model to verify the role of EETs in cardiotoxicity in vitro.

Results

CYP2J2 overexpression mitigated DOX-induced cardiotoxicity, as shown by the diminished cardiac injury marker levels, improved heart function, reduced oxidative stress, and inhibition of myocardial apoptosis in vivo. These protective roles are associated with the enhancement of antioxidant and anti-apoptotic abilities and the activation of the AMPK pathway. 14,15-EET suppresses DOX-induced oxidative stress, mitochondrial dysfunction, and apoptosis in H9C2 cells. AMPK knockdown partially abolished the cardioprotective effects of 14,15-EET against oxidative damage and apoptosis in DOX-treated cells, suggesting that AMPK is responsible for EET-mediated protection against cardiotoxicity.

Conclusion

CYP2J2-derived EETs confer myocardial protection against DOX-induced toxicity by activating the AMPK pathway, which reduces oxidative stress, mitochondrial dysfunction, and apoptosis.

Inhibition of ferroptosis by POLE2 in gastric cancer cells involves the activation of NRF2/GPX4 pathway

Gastric cancer results in great cancer mortality worldwide, and inducing ferroptosis dramatically improves the malignant phenotypes of gastric cancer. DNA polymerase epsilon subunit 2 (POLE2) plays indispensable roles in tumorigenesis; however, its involvement and molecular basis in ferroptosis and gastric cancer are not clear. Human gastric cancer cells were infected with lentiviral vectors to knock down or overexpress POLE2, and cell ferroptosis was detected. To further validate the involvement of nuclear factor erythroid 2-related factor 2 (NRF2) and glutathione peroxidase 4 (GPX4), lentiviral vectors were used. POLE2 expression was elevated in human gastric cancer cells and tissues and closely correlated with clinicopathological features in gastric cancer patients. POLE2 knockdown was induced, while POLE2 overexpression inhibited ferroptosis of human gastric cancer cells, thereby modulating the malignant phenotypes of gastric cancer. Mechanistic studies revealed that POLE2 overexpression elevated NRF2 expression and activity and subsequently activated GPX4, which then prevented lipid peroxidation and ferroptosis in human gastric cancer cells. In contrast, either NRF2 or GPX4 silence significantly prevented POLE2 overexpression-mediated inductions of cell proliferation, migration, invasion and inhibition of ferroptosis. POLE2 overexpression inhibits ferroptosis in human gastric cancer cells through activating NRF2/GPX4 pathway, and inhibiting POLE2 may be a crucial strategy to treat gastric cancer.

Matrine alleviates hypoxia-induced inflammation and pulmonary vascular remodelling via RPS5/NF-κB signalling pathway

Hypoxia-induced vasoconstriction and vascular remodelling are the main pathological features of hypoxic pulmonary arterial hypertension (HPAH), and inflammation is participated in the occurrence of pulmonary vascular remodelling (PVR). Matrine is an alkaloid with the effects of anti-inflammation, antifibrosis and antitumour. But, few studies have explored the role of matrine in regulating PVR, and the related mechanisms are still unknown. In this study, we found that hypoxia-induced pulmonary artery smooth muscle cells (PASMCs) proliferation and inhibited its apoptosis, reduced the expression of ribosomal protein s5 and activated the nuclear factor kappa-B (NF-κB) signalling. Matrine, sildenafil and NF-κB inhibitor Bay 11-7082 could reverse these changes and impel the cell cycle in phase S retardation, and reduced the expression of p50, p65, proliferating cell nuclear antigen (PCNA), Bcl-2. In addition, matrine could lower right ventricular systolic pressure and mean pulmonary artery pressure of rats, α-smooth muscle actin and PCNA expression in pulmonary artery media, the levels of tumor necrosis factor-α and interleuki-1β, thus improved hypoxia-induced PVR. This study indicated that matrine could alleviate inflammation and improve PVR through reversing the imbalance of proliferation and apoptosis of PASMCs, thus it had a therapeutic effect on HPAH.

PKD knockdown mitigates Ang II-induced cardiac hypertrophy and ferroptosis via the JNK/P53 signaling pathway

BACKGROUND

Cardiac hypertrophy is studied in relation to energy metabolism, autophagy, and ferroptosis, which are associated with cardiovascular adverse events and chronic heart failure. Protein kinase D (PKD) has been shown to play a degenerative role in cardiac hypertrophy. However, the role of ferroptosis in PKD-involved cardiac hypertrophy remains unclear.

METHODS

A cardiac hypertrophy model was induced by a subcutaneous injection of angiotensin II (Ang II) for 4 weeks. Adeno-associated virus serotype 9 (AAV9)-PKD or AAV9-Negative control were injected through the caudal vein 2 weeks prior to the injection of Ang II. The degree of cardiac hypertrophy was assessed using echocardiography and by observing cardiomyocyte morphology. Levels of ferroptosis and protein expression in the Jun N-terminal kinase (JNK)/P53 signaling pathway were measured both in vivo and in vitro.

RESULTS

The results indicated that PKD knockdown reduces Ang II-induced cardiac hypertrophy, enhances cardiac function and inhibits ferroptosis. The involvement of the JNK/P53 pathway in this process was further confirmed by in vivo and in vitro experiments.

CONCLUSION

In conclusion, our findings suggest that PKD knockdown mitigates Ang II-induced cardiac hypertrophy and ferroptosis via the JNK/P53 signaling pathway.

CD11b mediates hypertensive cardiac remodeling by regulating macrophage infiltration and polarization

INTRODUCTION

Leukocyte infiltration is an early event during cardiac remodeling frequently leading to heart failure (HF). Integrins mediate leukocyte infiltration during inflammation. However, the importance of specific integrins in hypertensive cardiac remodeling is still unclear.

OBJECTIVES

To elucidate the significance of CD11b in hypertensive cardiac remodeling.

METHODS

Angiotensin (Ang II) or deoxycorticosterone acetate (DOCA)-salt was used to induce cardiac remodeling in mice of gene knockout (KO), bone marrow (BM) chimera, and the CD11b neutralizing antibody or agonist leukadherin-1 (LA1) treatment.

RESULTS

Our microarray data showed that integrin subunits Itgam (CD11b) and Itgb2 (CD18) were the most highly upregulated in Ang II-infused hearts. CD11b expression and CD11b/CD18+ myelomonocytes were also time-dependently increased. KO or pharmacological blockade of CD11b greatly attenuated cardiac remodeling and macrophage infiltration and M1 polarization induced by Ang II or DOCA-salt. This protection was verified in wild-type mice transplanted with CD11b-deficient BM cells. Conversely, administration of CD11b agonist LA1 showed the opposite effects. Further, CD11b KO reduced Ang II-induced macrophage adhesion and M1 polarization, leading to reduction of cardiomyocyte enlargement and fibroblast differentiation in vitro. The numbers of CD14+CD11b+CD18+ monocytes and CD15+CD11b+CD18+ granulocytes were obviously higher in HF patients than in normal controls.

CONCLUSION

Our data demonstrate an important role of CD11b+ myeloid cells in hypertensive cardiac remodeling, and suggest that HF may benefit from targeting CD11b.

Deubiquitinase OTUB1 regulates doxorubicin-induced cardiotoxicity via deubiquitinating c-MYC

BACKGROUND

Doxorubicin (DOX), an anthracycline drug widely used in antitumor therapies, has dose-dependent toxicity that can cause cardiomyocyte apoptosis and oxidative stress, thus limiting its clinical application. OTUB1 (ovarian tumor associated proteinase B1) is an OTU superfamily deubiquitinase that effectively regulates cell proliferation, inflammatory responses, apoptosis, and oxidative stress by specifically removing K48- and K63-linked ubiquitination; however, its role in DOX-induced cardiotoxicity remains unknown.

MATERIALS AND METHODS

A DOX-induced subacute cardiotoxicity mouse model was established by intraperitoneal injection, and cardiac injury was assessed by echocardiography, serum cardiac markers, and histopathological staining. Western blotting, qRT-PCR, and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) immunohistochemistry were used to analyze cell apoptosis, tissue oxidative stress was assessed by superoxide dismutase (SOD) activity, malondialdehyde (MDA), and glutathione peroxidase (GSH-PX) activity. Cell counting kit-8 (CCK-8) assay, TUNEL staining, Western blotting, qRT-PCR, and reactive oxygen species (ROS) flow cytometry were applied on isolated neonatal mice cardiomyocytes to assess apoptosis and oxidative stress. Differentially expressed genes were analyzed using RNA sequencing and clustering analyses. c-MYC inhibitor 10,058-F4 and siRNA targeting c-Myc were used to investigate the roles of c-MYC in OTUB1's regulations of DOX-induced cardiotoxicity. Immunoprecipitation and Western blotting were performed to reveal the deubiquitinating effects of OTUB1 on c-MYC expression.

RESULTS

We found that global Otub1-knockdown in vivo alleviated the subacute DOX treatment-induced cardiac dysfunction, fibrosis, and cardiomyocyte atrophy. Mechanistically, unbiased RNA sequencing and molecular biology experiments revealed that cardiomyocyte apoptosis, inflammation, and oxidative stress in DOX-induced cardiotoxicity were significantly compromised in the Otub1-knockdown group. Further in vitro studies have shown that c-MYC, a critical regulator of apoptosis, is indispensable in OTUB1's regulations of DOX-induced cardiotoxicity. Deubiquitinating effects of OTUB1 on K48- and K63-linked ubiquitination of c-MYC protein are essential for promoting cardiomyocyte apoptosis and oxidative responses.

CONCLUSIONS

OTUB1-c-MYC inhibition protected cardiomyocytes against DOX-induced apoptosis and oxidative stress, suggesting that OTUB1 is a potential translational therapeutic target for preventing DOX-induced cardiotoxicity.

Growth differentiation factor 7 pretreatment enhances the therapeutic capacity of bone marrow-derived mesenchymal stromal cells against cerebral ischemia-reperfusion injury

Bone marrow-derived mesenchymal stem cells (BMSCs) transplantation is a promising therapeutic strategy for cerebral ischemia/reperfusion (I/R) injury; however, the clinical outcome is barely satisfactory and demands further improvement. The present study aimed to investigate whether preconditioning of BMSCs by recombinant human growth differentiation factor 7 (rhGDF7) could enhance its therapeutic capacity against cerebral I/R injury. Mouse BMSCs and primary neurons were co-cultured and exposed to oxygen glucose deprivation/reperfusion (OGD/R) stimulation. To investigate the role of exosomal microRNA-369-3p (miR-369-3p), inhibitors, RNAi and the miR-369-3p antagomir were used. Meanwhile, mice were intravenously injected with rhGDF7-preconditioned BMSCs and then received cerebral I/R surgery. Markers of inflammation, oxidative stress and neural damage were evaluated. To inhibit AMP-activated protein kinase (AMPK), compound C was used in vivo and in vitro. Compared with cell-free transwell or vehicle-preconditioned BMSCs, rhGDF7-preconditioned BMSCs significantly prevented OGD/R-induced inflammation, oxidative stress and neural damage in vitro. Meanwhile, rhGDF7-preconditioned BMSCs could prevent I/R-induced cerebral inflammation and oxidative stress in vivo. Mechanistically, rhGDF7 preconditioning significantly increased exosomal miR-369-3p expression in BMSCs and then transferred exosomal miR-369-3p to primary neurons, where it bound to phosphodiesterase 4 D (Pde4d) 3'-UTR and downregulated PDE4D expression, thereby preventing I/R-induced inflammation, oxidative stress and neural damage through activating AMPK pathway. Our study identify GDF7 pretreatment as a promising adjuvant reagent to improve the therapeutic potency of BMSCs for cerebral I/R injury and ischemic stroke.

Bisdemethoxycurcumin alleviates LPS-induced acute lung injury via activating AMPKα pathway

OBJECTIVE

Inflammation and oxidative stress contribute to the pathogenesis of acute lung injury (ALI), and subsequently result in rapid deterioration in health. Considering the indispensable role of bisdemethoxycurcumin (BDMC) in inflammation and oxidative stress, the present study aims to examine the effect of BDMC on sepsis-related ALI.

METHODS

C57BL/6 mice were administered with BDMC (100 mg/kg) or an equal volume of vehicle, and then injected with lipopolysaccharides (LPS) to induce ALI. We assessed the parameters of lung injury, inflammatory response and oxidative stress in lung tissues. Consistently, the macrophages with or without BDMC treatment were exposed to LPS to verify the effect of BDMC in vitro.

RESULTS

BDMC suppressed LPS-induced lung injury, inflammation and oxidative stress in vivo and in vitro. Mechanistically, BDMC increased the phosphorylation of AMPKα in response to LPS stimulation, and AMPK inhibition with Compound C almost completely blunted the protective effect of BDMC in LPS-treated mice and macrophages. Moreover, we demonstrated that BDMC activated AMPKα via the cAMP/Epac pathway.

CONCLUSION

Our study identifies the protective effect of BDMC against LPS-induced ALI, and the underlying mechanism may be related to the activation of cAMP/Epac/AMPKα signaling pathway.

Taxifolin protects against doxorubicin-induced cardiotoxicity and ferroptosis by adjusting microRNA-200a-mediated Nrf2 signaling pathway

The chemotherapeutic agent doxorubicin (Dox) is commonly used to treat various types of cancer, even though it can cause life-threatening cardiotoxicity. Clinically, there is no particularly effective way to treat Dox-induced cardiotoxicity. Therefore, it is imperative to identify compounds that can effectively alleviate Dox-induced cardiotoxicity. Ferroptosis and oxidative stress play a key role in Dox-induced cardiotoxicity, and the inhibition of ferroptosis and oxidative stress could effectively protect against doxorubicin-induced cardiotoxicity. Taxifolin (TAX) is a flavonoid commonly found in onions and citrus fruits. In the present study, we evaluated the effects of TAX on Dox-induced cardiac injury and dysfunction and aimed to explore the mechanisms underlying these effects. Using a mouse model of Dox-induced cardiotoxicity, we administered 20 mg/kg/day of TAX by gavage for 2 weeks. A week after the first use of TAX, each mouse was administered a 10 mg/kg dose of Dox. TAX was first evaluated for its cardioprotective properties, and the outcomes showed that TAX significantly reduced the damage caused by Dox to the myocardium in terms of structural and functional damage by effectively inhibiting ferroptosis and oxidative stress. In vivo, echocardiography, histopathologic assay, serum biochemical analysis and western blotting was used to find the results that Dox promoted ferroptosis-induced cardiomyocyte death, while TAX reversed these effects. In vitro, we also found that TAX alleviated Dox-induced cardiotoxicity by using ROS/DHE staining assay, Cellular immunofluorescence and western blotting. TAX increasing expression of microRNA-200a (miR-200a) which affects ferroptosis by activating Nrf2 signaling pathway. We believe that TAX inhibits ferroptosis and is a potential phytochemical that prevents Dox-induced cardiotoxicity.

Natural compounds as lactate dehydrogenase inhibitors: potential therapeutics for lactate dehydrogenase inhibitors-related diseases

Lactate dehydrogenase (LDH) is a crucial enzyme involved in energy metabolism and present in various cells throughout the body. Its diverse physiological functions encompass glycolysis, and its abnormal activity is associated with numerous diseases. Targeting LDH has emerged as a vital approach in drug discovery, leading to the identification of LDH inhibitors among natural compounds, such as polyphenols, alkaloids, and terpenoids. These compounds demonstrate therapeutic potential against LDH-related diseases, including anti-cancer effects. However, challenges concerning limited bioavailability, poor solubility, and potential toxicity must be addressed. Combining natural compounds with LDH inhibitors has led to promising outcomes in preclinical studies. This review highlights the promise of natural compounds as LDH inhibitors for treating cancer, cardiovascular, and neurodegenerative diseases.

CNIH4 governs cervical cancer progression through reducing ferroptosis

Cervical cancer is one of the most leading causes of cancer death worldwide, and ferroptosis is implicated in the progression of cervical cancer. Cornichon family AMPA receptor auxiliary protein 4 (CNIH4) is involved in the progression of various human cancers; however, its function in cervical cancer remains unclear. The present study aims to investigate the role and mechanism of CNIH4 in cervical cancer using gain- and loss-of-function studies in vitro. SiHa and CaSki cells were infected with lentiviral vectors to manipulate the expression of CNIH4 in vitro, and cell viability, migration, invasion as well as ferroptosis were evaluated. Transcriptome sequencing analysis was performed to further validate the mechanism through which CNIH4 regulated the progression of cervical cancer. The expression of CNIH4 was upregulated in human cervical cancer tissues and cells, and strongly correlated with the decreases in overall survival and disease free survival rates of cervical cancer patients. CNIH4 silence inhibited, while CNIH4 overexpression facilitated the survival of human cervical cancer cells. Mechanistically, CNIH4 elevated solute carrier family 7 member 11 (SLC7A11)-mediated cystine import, and subsequently increased intracellular glutathione synthesis and glutathione peroxidase 4 activity, thereby inhibiting ferroptosis of human cervical cancer cells. SLC7A11 silence significantly abolished CNIH4-mediated inhibition of ferroptosis in cervical cancer cells in vitro. Our study for the first time reveals that CNIH4 inhibits ferroptosis of human cervical cancer cells through upregulating SLC7A11, defining CNIH4 as an attractive therapeutic and prognostic target for cervical cancer.

ANGPTL2 aggravates LPS-induced septic cardiomyopathy via NLRP3-mediated inflammasome in a DUSP1-dependent pathway

Angiopoietin-like protein 2 (ANGPTL2) was implicated in various cardiovascular diseases; however, its role in lipopolysaccharide (LPS)-related septic cardiomyopathy remains unclear. Herein, mice were exposed to LPS to generate septic cardiomyopathy, and adeno-associated viral vector was employed to overexpress ANGPTL2 in the myocardium. Besides, mice were treated with adenoviral vector to knock down ANGPTL2 in hearts. ANGPTL2 expressions in hearts and cardiomyocytes were upregulated by LPS challenge. ANGPTL2 overexpression aggravated, while ANGPTL2 silence ameliorated LPS-associated cardiac impairment and inflammation. Mechanically, we found that ANGPTL2 activated NLRP3 inflammasome via suppressing DUSP1 signaling, and NLRP3 knockdown abrogated the detrimental role of ANGPTL2 in aggravating LPS-induced cardiac inflammation. Furthermore, DUSP1 overexpression significantly inhibited ANGPTL2-mediated NLRP3 activation, and subsequently improved LPS-related cardiac dysfunction. In summary, ANGPTL2 exacerbated septic cardiomyopathy via activating NLRP3-mediated inflammation in a DUSP1-dependent manner, and our study uncovered a promising therapeutic target in preventing septic cardiomyopathy.

MEGF6 prevents sepsis-induced acute lung injury in mice

OBJECTIVE

Acute lung injury (ALI) is featured as excessive inflammatory response and oxidative damage, and results in high death rate of septic patients. This research intends to determine the function of multiple EGF like domains 6 (MEGF6) in sepsis-induced ALI.

METHODS

Mice were intratracheally treated with adenovirus to knock down or overexpress MEGF6 in lung tissues, and then were subjected to cecum ligation and puncture (CLP) operation to induce ALI. Primary peritoneal macrophages were isolated, and were knocked down or overexpressed with MEGF6, and then, were stimulated with lipopolysaccharide (LPS) to confirm its role in vitro.

RESULTS

Serum and lung MEGF6 levels were significantly elevated in septic mice. MEGF6 knockdown exacerbated, while MEGF6 overexpression prevented inflammation, oxidative damage and ALI in CLP mice. Meanwhile, LPS-elicited inflammatory response and oxidative damage in primary macrophages were reduced by MEGF6 overexpression, but were further aggravated by MEGF6 knockdown. Mechanistic studies revealed that MEGF6 reduced cluster of differentiation 38 (CD38) expression and subsequently elevated intracellular nicotinamide adenine dinucleotide levels, thereby activating sirtuin 1 (SIRT1) without affecting the protein expression. SIRT1 suppression or CD38 overexpression with either genetic or pharmacologic methods remarkably blunted the lung protective effects of MEGF6 in CLP mice.

CONCLUSION

MEGF6 prevents CLP-induced ALI through CD38/SIRT1 pathway, and it might be a valuable therapeutic candidate for the management of sepsis-induced ALI.

Peficitinib ameliorates doxorubicin-induced cardiotoxicity by suppressing cellular senescence and enhances its antitumor activity

Irreversible cardiotoxicity limits the clinical applications of doxorubicin (DOX). Cardiotoxicity can be detected early using clinical assessment; however, effective preventive measures are still lacking. Peficitinib (ASP015K), a JAK (Janus kinase) inhibitor, is a potent anti-inflammatory agent in autoimmune diseases. Nevertheless, little research has been conducted on anti-ageing and anti-tumour therapies. In this study, we investigated whether ASP015K could attenuate DOX-induced cardiotoxicity through its anti-ageing effects and whether it would affect the tumour treatment effect of DOX by establishing senescence, acute heart injury, and xenograft models. We observed that ASP015K could antagonise the senescence induced by various factors, including hydrogen peroxide and DOX. In addition, ASP015K treatment significantly alleviated cardiac function damage, histopathological deterioration, myocardial fibrosis, and oxidative damage in acute injury mouse models. ASP015K enhanced the sensitivity of tumour cells to DOX therapy and significantly slowed down the tumour growth rate and tumour volume in the xenograft mouse model. Therefore, ASP015K is expected to be developed as a potential cardioprotective agent to prevent or reduce the cardiotoxic side effects of anthracyclines in chemotherapy.

Research Progress of Natural Matrine Compounds and Synthetic Matrine Derivatives

Matrine is a quinoline alkaloid extracted and separated from the dried root, fruit, and other parts of the plant Sophora flavescens using an organic solvent. Matrine exhibits a variety of biological activities and is widely used in pharmacy, agronomy, and other fields. Due to its low bioavailability, poor chemical stability, and toxicity to the central nervous system, a large number of researchers have searched for matrine derivatives with higher biological activity and safety by modifying its structure. In this review article, the research progress of matrine derivatives obtained using two methods (extraction from Sophora flavescens and structural modifications) from 2018 to 2022 in terms of pharmacological activity, mechanism of action, and structure-activity relationship are presented. The modification of matrine over the past five years has been mainly on the D-ring. Many new matrine alkaloids have been extracted from natural products, some of which have good pharmacological activity, which broadens the strategy for matrine structural modification in the future.

MicroRNA-32-3p facilitates cerebral ischemia/reperfusion injury through inhibiting Cab39/AMPK

Oxidative stress is a key pathogenic factor of cerebral ischemia/reperfusion (I/R) injury. MicroRNA-32-3p (miR-32-3p) plays critical roles in regulating ischemic diseases; however, its role in oxidative stress and cerebral I/R injury remains elusive. Primary cortical neurons and rats were treated with the agomir, antagomir and matched controls of miR-32-3p, and then received oxygen glucose deprivation/reperfusion (OGD/R) or I/R stimulation. To investigate the involvement of AMP-activated protein kinase (AMPK) and calcium-binding protein 39 (Cab39), a pharmacological inhibitor and small interfering RNA were used in vivo and in vitro. Herein, we found that miR-32-3p was upregulated in OGD/R-treated neurons and I/R-injured brains, and that inhibiting miR-32-3p by the miR-32-3p antagomir dramatically alleviated oxidative stress and neural death in OGD/R-stimulated primary cortical neurons. Conversely, overexpressing miR-32-3p by the miR-32-3p agomir further aggravated OGD/R-induced neural death and oxidative damage in primary cortical neurons. Meanwhile, we observed that the miR-32-3p antagomir prevented, while the miR-32-3p agomir facilitated neural death, oxidative damage and cerebral I/R injury in vivo. Mechanistically, miR-32-3p bound to the 3'-untranslated regions of Cab39, inhibited its protein level and subsequently inactivated AMPK. Conversely, treatment with the miR-32-3p antagomir upregulated Cab39 and activated AMPK, thereby attenuating oxidative damage and cerebral I/R injury. Moreover, inhibiting AMPK or Cab39 dramatically blocked the miR-32-3p antagomir-mediated beneficial effects against cerebral I/R injury in vivo and in vitro. miR-32-3p plays critical roles in neural death and oxidative damage upon I/R stimulation, and it is a novel target to treat cerebral I/R injury.

Leucine zipper protein 1 prevents doxorubicin-induced cardiotoxicity in mice

OBJECTIVE

Doxorubicin (DOX) is commonly used for chemotherapy; however, its clinical value is extremely dampened because of the fatal cardiotoxicity. Leucine zipper protein 1 (LUZP1) plays critical roles in cardiovascular development, and this study is designed for determining its function and mechanism in DOX-induced cardiotoxicity.

METHODS

Cardiac-specific Luzp1 knockout (cKO) and transgenic (cTG) mice received a single or repeated DOX injections to establish acute and chronic cardiotoxicity. Biomarkers of inflammation, oxidative damage and cell apoptosis were evaluated. Transcriptome and co-immunoprecipitation analysis were used to screen the underlying molecular pathways. Meanwhile, primary cardiomyocytes were applied to confirm the beneficial effects of LUZP1 in depth.

RESULTS

LUZP1 was upregulated in DOX-injured hearts and cardiomyocytes. Cardiac-specific LUZP1 deficiency aggravated, while cardiac-specific LUZP1 overexpression attenuated DOX-associated inflammation, oxidative damage, cell apoptosis and acute cardiac injury. Mechanistic studies revealed that LUZP1 ameliorated DOX-induced cardiotoxicity through activating 5'-AMP-activated protein kinase (AMPK) pathway, and AMPK deficiency abolished the cardioprotection of LUZP1. Further findings suggested that LUZP1 interacted with protein phosphatase 1 to activate AMPK pathway. Moreover, we determined that cardiac-specific LUZP1 overexpression could also attenuate DOX-associated chronic cardiac injury in mice.

CONCLUSION

LUZP1 attenuates DOX-induced inflammation, oxidative damage, cell apoptosis and ventricular impairment through regulating AMPK pathway, and gene therapy targeting LUZP1 may provide novel therapeutic approached to treat DOX-induced cardiotoxicity.

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

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

Pharmacological mechanism of natural drugs and their active ingredients in the treatment of arrhythmia via calcium channel regulation

Arrhythmia is characterized by abnormal heartbeat rhythms and frequencies caused by heart pacing and conduction dysfunction. Arrhythmia is the leading cause of death in patients with cardiovascular disease, with high morbidity and mortality rates, posing a serious risk to human health. Natural drugs and their active ingredients, such as matrine(MAT), tetrandrine(TET), dehydroevodiamine, tanshinone IIA, and ginsenosides, have been widely used for the treatment of atrial fibrillation, ventricular ectopic beats, sick sinus syndrome, and other arrhythmia-like diseases owing to their unique advantages. This review summarizes the mechanism of action of natural drugs and their active ingredients in the treatment of arrhythmia via the regulation of Ca²⁺, such as alkaloids, quinones, saponins, terpenoids, flavonoids, polyphenols, and lignan compounds, to provide ideas for the innovative development of natural drugs with potential antiarrhythmic efficacy.

Hydrogen sulfide alleviates mitochondrial damage and ferroptosis by regulating OPA3-NFS1 axis in doxorubicin-induced cardiotoxicity

Ferroptosis is a major cause of cardiotoxicity induced by doxorubicin (DOX). Previous studies have shown that hydrogen sulfide (H₂S) inhibits ferroptosis in cardiomyocytes and myoblasts, but the underlying mechanism has not been fully elucidated. In this study, we investigated the role of H₂S in protecting against DOX-induced cardiotoxicity both in vivo and in vitro, and elucidated the potential mechanisms involved. We found that DOX downregulated the expression of glutathione peroxidase 4 (GPX4) and NFS1, and upregulated the expression of acyl-coenzyme A synthetase long-chain family member 4 (ACSL4) expression level, resulting in increased lipid peroxidation and ferroptosis. Additionally, DOX inhibited MFN2 expression and increased DRP1 and FIS1 expression, leading to abnormal mitochondrial structure and function. In contrast, exogenous H₂S inhibited DOX-induced ferroptosis by restoring GPX4 and NFS1 expression, and reducing lipid peroxidation in H9C2 cells. This effect was similar to that of the ferroptosis antagonist ferrostatin-1 (Fer-1) in protecting against DOX-induced cardiotoxicity. We further demonstrated that the protective effect of H₂S was mediated by the key mitochondrial membrane protein optic atrophy 3 (OPA3), which was downregulated by DOX and restored by exogenous H₂S. Overexpression of OPA3 alleviated DOX-induced mitochondrial dysfunction and ferroptosis both in vivo and in vitro. Mechanistically, NFS1 has an inhibitory effect on ferroptosis, and NFS1 deficiency increases the susceptibility of cardiomyocytes to ferroptosis. OPA3 is involved in the regulation of ferroptosis by interacting with NFS1. Post-translationally, DOX promoted OPA3 ubiquitination, while exogenous H₂S antagonized OPA3 ubiquitination by promoting OPA3 s-sulfhydration. In summary, our findings suggested that H₂S protects against DOX-induced cardiotoxicity by inhibiting ferroptosis via targeting the OPA3-NFS1 axis. This provides a potential therapeutic strategy for the treatment of DOX-induced cardiotoxicity.

Protective role of cezanne in doxorubicin-induced cardiotoxicity by inhibiting autophagy, apoptosis and oxidative stress

Doxorubicin (DOX) is frequently used in clinical practice for its broad-spectrum effects. However, its benefit is limited by a series of complications, including excessive apoptosis and autophagy of cardiomyocytes, overproduction of reactive oxygen species (ROS) and high level of oxidative stress. As a new protein, OTU domain-containing 7B (OTUD7B), also called Cezanne, has been reported to regulate many pathological processes. However, whether it plays a role in DOX-induced cardiotoxicity is still unclear. We discovered that the Cezanne level was significantly increased in DOX-treated neonatal rat cardiomyocytes (NRCMs) and C57BL/6 J mice hearts. In vitro, the knockdown of Cezanne with adenovirus in NRCMs significantly worsened DOX-induced apoptosis, autophagy and oxidative stress, while Cezanne overexpression showed opposite results. In vivo, the overexpression of Cezanne using cardiomyocyte-targeted adeno-associated virus 9 (AAV9) significantly reduced cardiomyocyte apoptosis, autophagy and oxidative stress level when C57BL/6 J mice were subjected to DOX. Mechanistically, the overexpression of Cezanne significantly reversed the in-activation of the PI3K/AKT/mTOR pathway induced by DOX, while the inhibitors of this pathway abolished the effect of Cezanne, suggesting that the PI3K/AKT/mTOR pathway plays a role in the protective function of Cezanne. These findings indicate that Cezanne could ameliorate DOX-induced cardiotoxicity by attenuating the apoptosis and autophagy of cardiomyocytes and decreasing the level of oxidative stress.

TYMSOS-miR-101-3p-NETO2 axis promotes osteosarcoma progression

BACKGROUND

Osteosarcoma (OS) is a type of bone cancer most often affects pre-teens and teens, but it is still a rare disorder. Neuropilin and tolloid-like 2 (NETO2) has been reported to promote OS progression, but its upstream mechanism in OS cells remains obscure.

METHODS

Quantitative real-time PCR (RT-qPCR) and Western blot were conducted to examine RNA and protein levels, separately. Functional assays were performed to assess the impact of NETO2 on OS cell malignancy. Moreover, bioinformatics analyses and mechanism experiments were performed to identify the upstream mechanism of NETO2 in OS cells.

RESULTS

Functionally, NETO2 depletion repressed cell proliferation, migration and invasion as well as epithelial-mesenchymal transition (EMT) but triggered the apoptosis of OS cells. NETO2 is directly targeted and negatively regulated by microRNA-101-3p (miR-101-3p). Mechanically, miR-101-3p could combine with long noncoding RNA (lncRNA) TYMS opposite strand RNA (TYMSOS) in OS cells. In addition, our study proved that TYMSOS promotes the malignancy of OS via elevating NETO2 expression as miR-101-3p sponge.

CONCLUSION

TYMSOS-miR-101-3p-NETO2 axis promotes the malignant behaviors of OS cells, which might offer a novel sight for OS treatment.

TRIM6 Reduces Ferroptosis and Chemosensitivity by Targeting SLC1A5 in Lung Cancer

Objective

Ferroptosis, a newly identified form of cell death, plays critical roles in the development and chemoresistance of lung cancer. Tripartite motif 6 (TRIM6) acts as an E3-ubiquitin ligase and can promote the progression of human colorectal cancer. The present study is aimed at investigating its role and potential mechanisms in lung cancer.

Methods

Lentiviral vectors were used to overexpress or knock down TRIM6 in human lung cancer cells. Cell survival, colony formation, lipid peroxidation, intracellular iron levels, and other ferroptotic markers were examined. The role of TRIM6 on ferroptosis and chemosensitivity was further tested in mouse tumor xenograft models.

Results

TRIM6 was highly expressed in human lung cancer tissues and cells, and its expression in the lung cancer cells was further increased by ferroptotic stimulation. TRIM6 overexpression inhibited, while TRIM6 silence promoted erastin- and RSL3-induced glutaminolysis and ferroptosis in the lung cancer cells. Mechanistically, TRIM6 directly interacted with solute carrier family 1 member 5 to promote its ubiquitination and degradation, thereby inhibiting glutamine import, glutaminolysis, lipid peroxidation, and ferroptotic cell death. Moreover, we observed that TRIM6 overexpression reduced the chemotherapeutic effects of cisplatin and paclitaxel. In contrast, TRIM6 silence sensitized human lung cancer cells to cisplatin and paclitaxel in vivo and in vitro.

Conclusion

Our findings for the first time define TRIM6 as a negative regulator of ferroptosis in the lung cancer cells, and TRIM6 overexpression enhances the resistance of human lung cancer cells to chemotherapeutic drugs. Overall, targeting TRIM6 may help to establish novel strategies to treat lung cancer.

Modulation of type I interferon signaling by natural products in the treatment of immune-related diseases

Type I interferon (IFN) is considered as a bridge between innate and adaptive immunity. Proper activation or inhibition of type I IFN signaling is essential for host defense against pathogen invasion, tumor cell proliferation, and overactive immune responses. Due to intricate and diverse chemical structures, natural products and their derivatives have become an invaluable source inspiring innovative drug discovery. In addition, some natural products have been applied in clinical practice for infection, cancer, and autoimmunity over thousands of years and their promising curative effects and safety have been well-accepted. However, whether these natural products are primarily targeting type I IFN signaling and specific molecular targets involved are not fully elucidated. In the current review, we thoroughly summarize recent advances in the pharmacology researches of natural products for their type I IFN activity, including both agonism/activation and antagonism/inhibition, and their potential application as therapies. Furthermore, the source and chemical nature of natural products with type I IFN activity are highlighted and their specific molecular targets in the type I IFN pathway and mode of action are classified. In conclusion, natural products possessing type I IFN activity represent promising therapeutic strategies and have a bright prospect in the treatment of infection, cancer, and autoimmune diseases.

Growth Differentiation Factor 7 Prevents Sepsis-Induced Acute Lung Injury in Mice

Objective

Acute lung injury (ALI) is a life-threatening complication during sepsis and contributes to multiple organ failure and high mortality for septic patients. The present study aims to investigate the role and molecular basis of growth differentiation factor 7 (GDF7) in sepsis-induced ALI.

Methods

Mice were subcutaneously injected with recombinant mouse GDF7 Protein (rmGDF7) and then intratracheally injected with lipopolysaccharide (LPS) to generate sepsis-induced ALI. Primary peritoneal macrophages were isolated to further evaluate the role and underlying mechanism of GDF7 in vitro.

Results

GDF7 was downregulated in LPS-stimulated lung tissues, and rmGDF7 treatment significantly inhibited inflammation and oxidative stress in ALI mice, thereby preventing LPS-induced pulmonary injury and dysfunction. Mechanistically, we found that rmGDF7 activated AMP-activated protein kinase (AMPK), and AMPK inhibition significantly blocked the anti-inflammatory and antioxidant effects of rmGDF7 during LPS-induced ALI. Further findings revealed that rmGDF7 activated AMPK through a downregulated stimulator of interferon gene (STING) in vivo and in vitro.

Conclusion

GDF7 prevents LPS-induced inflammatory response, oxidative stress, and ALI by regulating the STING/AMPK pathway. Our findings for the first time identify GDF7 as a potential agent for the treatment of sepsis-induced ALI.

Macrophage Sprouty4 deficiency diminishes sepsis-induced acute lung injury in mice

OBJECTIVE

Inflammation and oxidative stress play critical roles in sepsis-induced acute lung injury (ALI). Sprout4 (Spry4) is involved in regulating inflammation and tissue injury; however, its role and mechanism in sepsis-induced ALI remain elusive.

METHODS

Macrophage-specific Spry4 knockout (Spry4^MKO), transgenic (Spry4^MTG) mice and matched control littermates were generated and exposed to cecum ligation and puncture (CLP) surgery to establish bacterial sepsis-induced ALI. Bone marrow-derived macrophages (BMDMs) from Spry4^MKO or Spry4^MTG mice were isolated and subjected to lipopolysaccharide (LPS) stimulation to further validate the role of Spry4 in vitro. To verify the necessity of AMP-activated protein kinase (AMPK), Spry4 and AMPK double knockout mice and compound C were used in vivo and in vitro. BMDMs were treated with STO-609 to inhibit calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2).

RESULTS

We found that macrophage Spry4 was increased in CLP mice and positively correlated with sepsis-induced ALI. Macrophage Spry4 deficiency prevented, while macrophage Spry4 overexpression exacerbated sepsis-induced inflammation, oxidative stress and ALI in mice and BMDMs. Mechanistic studies revealed that macrophage Spry4 deficiency alleviated sepsis-induced ALI through activating CaMKK2/AMPK pathway.

CONCLUSION

Our study identify macrophage Spry4 as a promising predictive and therapeutic target of sepsis-induced ALI.

Macrophage SAMSN1 protects against sepsis-induced acute lung injury in mice

OBJECTIVE

Inflammation and oxidative stress contribute to the progression of sepsis-induced acute lung injury (ALI). SAM domain, SH3 domain and nuclear localization signals 1 (SAMSN1) is a signaling adaptor protein, and mainly regulates inflammatory response of various immune cells. The present study generates macrophage-specific SAMSN1-knockout (Samsn1MKO) and SAMSN1-transgenic (Samsn1MTG) mice to investigate its role and mechanism in sepsis-induced ALI.

METHODS

Samsn1MKO and Samsn1MTG mice were exposed to lipopolysaccharide (LPS) instillation or cecal ligation and puncture (CLP) surgery to induce sepsis-induced ALI. Bone marrow transplantation, cellular depletion and non-invasive adoptive transfer of bone marrow-derived macrophages (BMDMs) were performed to validate the role of macrophage SAMSN1 in sepsis-induced ALI in vivo. Meanwhile, BMDMs were isolated from Samsn1MKO or Samsn1MTG mice to further clarify the role of SAMSN1 in vitro.

RESULTS

Macrophage SAMSN1 expression was increased in response to LPS stimulation, and negatively correlated with LPS-induced ALI in mice. Macrophage SAMSN1 deficiency exacerbated, while macrophage SAMSN1 overexpression ameliorated LPS-induced inflammation, oxidative stress and ALI in mice and in BMDMs. Mechanistically, we found that macrophage SAMSN1 overexpression prevented LPS-induced ALI though activating AMP-activated protein kinase α2 (AMPKα2) in vivo and in vitro. Further studies revealed that SAMSN1 directly bound to growth factor receptor bound protein 2-associated protein 1 (GAB1) to prevent its protein degradation, and subsequently enhanced protein kinase A (PKA)/AMPKα2 activation in a protein tyrosine phosphatase, non-receptor type 11 (PTPN11, also known as SHP2)-dependent manner. Moreover, we observed that macrophage SAMSN1 overexpression diminished CLP-induced ALI in mice.

CONCLUSION

Our study documents the protective role of macrophage SAMSN1 against sepsis-induced inflammation, oxidative stress and ALI through activating AMPKα2 in a GAB1/SHP2/PKA pathway, and defines it as a promising biomarker and therapeutic target to treat sepsis-induced ALI.

Effect of injection of different doses of isoproterenol on the hearts of mice

Background

Heart failure (HF) is one of the diseases that seriously threaten human health today and its mechanisms are very complex. Our study aims to confirm the optimal dose ISO-induced chronic heart failure mice model for better study of HF-related mechanisms and treatments in the future.

Methods

C57BL/6 mice were used to establish mice model of chronic heart failure. We injected isoproterenol subcutaneously in a dose gradient of 250 mg/kg, 200 mg/kg, 150 mg/kg, 100 mg/kg and 50 mg/kg. Echocardiography and ELISA were performed to figure out the occurrence of HF. We also supplemented the echocardiographic changes in mice over 30 days.

Results

Except group S and group E, echocardiographic abnormalities were found in other groups, suggesting a decrease in cardiac function. Except group S, myofibrolysis were found in the hearts of mice in other groups. Brain natriuretic peptide was significantly increased in groups B and D, and C-reactive protein was significantly increased in each group.

Conclusion

Our research finally found that the HFrEF mice model created by injection at a dose of 100 mg/kg for 7 days was the most suitable and a relatively stable chronic heart failure model could be obtained by placing it for 21 days.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02852-x.

Modulation of integrin receptor by polyphenols: Downstream Nrf2-Keap1/ARE and associated cross-talk mediators in cardiovascular diseases

As a group of heterodimeric and transmembrane glycoproteins, integrin receptors are widely expressed in various cell types overall the body. During cardiovascular dysfunction, integrin receptors apply inhibitory effects on the antioxidative pathways, including nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch like ECH Associated Protein 1 (Keap1)/antioxidant response element (ARE) and interconnected mediators. As such, dysregulation in integrin signaling pathways influences several aspects of cardiovascular diseases (CVDs) such as heart failure, arrhythmia, angina, hypertension, hyperlipidemia, platelet aggregation and coagulation. So, modulation of integrin pathway could trigger the downstream antioxidant pathways toward cardioprotection. Regarding the involvement of multiple aforementioned mediators in the pathogenesis of CVDs, as well as the side effects of conventional drugs, seeking for novel alternative drugs is of great importance. Accordingly, the plant kingdom could pave the road in the treatment of CVDs. Of natural entities, polyphenols are multi-target and accessible phytochemicals with promising potency and low levels of toxicity. The present study aims at providing the cardioprotective roles of integrin receptors and downstream antioxidant pathways in heart failure, arrhythmia, angina, hypertension, hyperlipidemia, platelet aggregation and coagulation. The potential role of polyphenols has been also revealed in targeting the aforementioned dysregulated signaling mediators in those CVDs.

TRIM7 modulates NCOA4-mediated ferritinophagy and ferroptosis in glioblastoma cells

Objective

Glioblastoma is one of the most common intracranial malignant tumors with an unfavorable prognosis, and iron metabolism as well as ferroptosis are implicated in the pathogenesis of glioblastoma. The present study aims to decipher the role and mechanisms of tripartite motif-containing protein 7 (TRIM7) in ferroptosis and glioblastoma progression.

Methods

Stable TRIM7-deficient or overexpressing human glioblastoma cells were generated with lentiviral vectors, and cell survival, lipid peroxidation and iron metabolism were evaluated. Immunoprecipitation, protein degradation and ubiquitination assays were performed to demonstrate the regulation of TRIM7 on its candidate proteins.

Results

TRIM7 expression was elevated in human glioblastoma cells and tissues. TRIM7 silence suppressed growth and induced death, while TRIM7 overexpression facilitated growth and inhibited death of human glioblastoma cells. Meanwhile, TRIM7-silenced cells exhibited increased iron accumulation, lipid peroxidation and ferroptosis, which were significantly reduced by TRIM7 overexpression. Mechanistically, TRIM7 directly bound to and ubiquitinated nuclear receptor coactivator 4 (NCOA4) using K48-linked chains, thereby reducing NCOA4-mediated ferritinophagy and ferroptosis of human glioblastoma cells. Moreover, we found that TRIM7 deletion sensitized human glioblastoma cells to temozolomide therapy.

Conclusion

We for the first time demonstrate that TRIM7 modulates NCOA4-mediated ferritinophagy and ferroptosis in glioblastoma cells, and our findings provide a novel insight into the progression and treatment for human glioblastoma.

MicroRNA-147a Targets SLC40A1 to Induce Ferroptosis in Human Glioblastoma

Objective. Glioblastoma is one of the most common malignant tumors in the brain, and these glioblastoma patients have very poor prognosis. Ferroptosis is involved in the progression of various tumors, including the glioblastoma. This study aims to determine the involvement of microRNA (miR)-147a in regulating ferroptosis of glioblastoma in vitro. Methods. Human glioblastoma cell lines were transfected with the inhibitor, mimic and matched negative controls of miR-147a in the presence or absence of ferroptotic inducers. To knock down the endogenous solute carrier family 40 member 1 (SLC40A1), cells were transfected with the small interfering RNA against SLC40A1. In addition, cells with or without the miR-147a mimic treatment were also incubated with temozolomide (TMZ) to investigate whether miR-147a overexpression could sensitize human glioblastoma cells to TMZ chemotherapy in vitro. Results. We found that miR-147a level was decreased in human glioblastoma tissues and cell lines and that the miR-147a mimic significantly suppressed the growth of glioblastoma cells in vitro. In addition, miR-147a expression was elevated in human glioblastoma cells upon erastin or RSL3 stimulation. Treatment with the miR-147a mimic significantly induced ferroptosis of glioblastoma cells, and the ferroptotic inhibitors could block the miR-147a mimic-mediated tumor suppression in vitro. Conversely, the miR-147a inhibitor prevented erastin- or RSL3-induced ferroptosis and increased the viability of glioblastoma cells in vitro. Mechanistically, we determined that miR-147a directly bound to the 3 $\prime$ -untranslated region of SLC40A1 and inhibited SLC40A1-mediated iron export, thereby facilitating iron overload, lipid peroxidation, and ferroptosis. Furthermore, miR-147a mimic-treated human glioblastoma cells exhibited higher sensitivity to TMZ chemotherapy than those treated with the mimic control in vitro. Conclusion. We for the first time determine that miR-147a targets SLC40A1 to induce ferroptosis in human glioblastoma in vitro.

MicroRNA-1224-5p Aggravates Sepsis-Related Acute Lung Injury in Mice

Oxidative stress and inflammation are implicated in the development of sepsis-related acute lung injury (ALI). MicroRNA-1224-5p (miR-1224-5p) plays critical roles in regulating inflammatory response and reactive oxygen species (ROS) production. The present study is aimed at investigating the role and underlying mechanisms of miR-1224-5p in sepsis-related ALI. Mice were intratracheally injected with lipopolysaccharide (LPS, 5 mg/kg) for 12 h to induce sepsis-related ALI. To manipulate miR-1224-5p level, mice were intravenously injected with the agomir, antagomir, or matched controls for 3 consecutive days. Murine peritoneal macrophages were stimulated with LPS (100 ng/mL) for 6 h to further validate the role of miR-1224-5p in vitro. To inhibit adenosine 5′-monophosphate-activated protein kinase alpha (AMPKα) or peroxisome proliferator activated receptor-gamma (PPAR-γ), compound C or GW9662 was used in vivo and in vitro. We found that miR-1224-5p levels in lungs were elevated by LPS injection, and that the miR-1224-5p antagomir significantly alleviated LPS-induced inflammation, oxidative stress, and ALI in mice. Conversely, the miR-1224-5p agomir aggravated inflammatory response, ROS generation, and pulmonary dysfunction in LPS-treated mice. In addition, the miR-1224-5p antagomir reduced, while the miR-1224-5p agomir aggravated LPS-induced inflammation and oxidative stress in murine peritoneal macrophages. Further findings revealed that miR-1224-5p is directly bound to the 3′-untranslated regions of PPAR-γ and subsequently suppressed PPAR-γ/AMPKα axis, thereby aggravating LPS-induced ALI in vivo and in vitro. We demonstrate for the first time that endogenous miR-1224-5p is a critical pathogenic factor for inflammation and oxidative damage during LPS-induced ALI through inactivating PPAR-γ/AMPKα axis. Targeting miR-1224-5p may help to develop novel approaches to treat sepsis-related ALI.

Zedoarondiol inhibits atherosclerosis by regulating monocyte migration and adhesion via CXCL12/CXCR4 pathway

Atherosclerosis (AS) is an essential pathological changes of ischemic cardio-cerebrovascular disease, and monocyte migration and adhesion to endothelial cells are the critical pathological process in AS. Our previous studies demonstrated a beneficial effect of zedoarondiol in AS, but whether the mechanism is associated with monocyte migration and adhesion to endothelial cells remains unclear. In this study, we investigated whether the anti-atherosclerotic effects of zedoarondiol were associated with decreasing migration and adhesion of monocytes. The oil red O staining demonstrated that zedoarondiol ameliorated AS plaques in en face aorta and aortic root of apolipoprotein E gene knocked (apoE^-/-) mice. In vitro, zedoarondiol decreased human monocytic macrophage-like cell line (THP-1) monocytes migration and adhesion to endothelial cells. Single-cell RNA sequencing analysis (scRNA-seq) in mice indicated that zedoarondiol decreased monocytes adhesion to endothelial cells by regulating CXC chemokine ligand 12/CXC chemokine receptor 4 (CXCL12/CXCR4) pathway, which was verified by Western blot of THP-1 monocytes；zedoarondiol also decreased the expressions of phosphoinositide 3-kinase (PI3K), protein kinase B (AKT) and nuclear factor-kappa B (NF/κB), the downstream proteins of CXCL12/CXCR4 pathway. In conclusion, zedoarondiol ameliorated AS plaque and inhibited monocyte migration and adhesion to endothelial cells via regulating CXCL12/CXCR4 pathway, suggesting that zedoarondiol might be a new promising drug for AS.

Liquiritin Attenuates Pathological Cardiac Hypertrophy by Activating the PKA/LKB1/AMPK Pathway

Background: Liquiritin (LQ) is one of the main flavonoids extracted from the roots of Glycyrrhiza spp., which are widely used in traditional Chinese medicine. Studies in both cellular and animal disease models have shown that LQ attenuates or prevents oxidative stress, inflammation, and apoptosis. However, the potential therapeutic effects of LQ on pressure overload-induced cardiac hypertrophy have not been so far explored. Therefore, we investigated the cardioprotective role of LQ and its underlying mechanisms in the aortic banding (AB)-induced cardiac hypertrophy mouse model.

Methods and Results: Starting 3 days after AB surgery, LQ (80 mg/kg/day) was administered daily over 4 weeks. Echocardiography and pressure-volume loop analysis indicated that LQ treatment markedly improved hypertrophy-related cardiac dysfunction. Moreover, hematoxylin and eosin, picrosirius red, and TUNEL staining showed that LQ significantly inhibited cardiomyocyte hypertrophy, interstitial fibrosis, and apoptosis. Western blot assays further showed that LQ activated LKB1/AMPKα2/ACC signaling and inhibited mTORC1 phosphorylation in cardiomyocytes. Notably, LQ treatment failed to prevent cardiac dysfunction, hypertrophy, and fibrosis in AMPKα2 knockout (AMPKα2^−/−) mice. However, LQ still induced LKB1 phosphorylation in AMPKα2^−/− mouse hearts. In vitro experiments further demonstrated that LQ inhibited Ang II-induced hypertrophy in neonatal rat cardiomyocytes (NRCMs) by increasing cAMP levels and PKA activity. Supporting the central involvement of the cAMP/PKA/LKB1/AMPKα2 signaling pathway in the cardioprotective effects of LQ, inhibition of Ang II-induced hypertrophy and induction of LKB1 and AMPKα phosphorylation were no longer observed after inhibiting PKA activity.

Conclusion: This study revealed that LQ alleviates pressure overload-induced cardiac hypertrophy in vivo and inhibits Ang II-induced cardiomyocyte hypertrophy in vitro via activating cAMP/PKA/LKB1/AMPKα2 signaling. These findings suggest that LQ might be a valuable adjunct to therapeutic approaches for treating pathological cardiac remodeling.

MicroRNA-4735-3p Facilitates Ferroptosis in Clear Cell Renal Cell Carcinoma by Targeting SLC40A1

Objective. Clear cell renal cell carcinoma (ccRCC) is the major histopathological subtype of renal cancer, and ferroptosis is implicated in the pathogenesis of ccRCC. The present study was aimed at investigating the role and underlying mechanisms of microRNA-4735-3p (miR-4735-3p) in ccRCC. Methods. Human ccRCC cell lines were transfected with the miR-4735-3p mimic or inhibitor to manipulate the expression of miR-4735-3p. Cell proliferation, colony formation, cell migration, cell invasion, cell death, oxidative stress, lipid peroxidation, and iron metabolism were determined. To validate the necessity of solute carrier family 40 member 1 (SLC40A1), human ccRCC cell lines were overexpressed with SLC40A1 using adenoviral vectors. Results. miR-4735-3p expression was reduced in human ccRCC tissues and cell lines but elevated upon ferroptotic stimulation. The miR-4735-3p mimic increased, while the miR-4735-3p inhibitor decreased oxidative stress, lipid peroxidation, iron overload, and ferroptosis of human ccRCC cell lines. Mechanistic studies identified SLC40A1 as a direct target of miR-4735-3p, and SLC40A1 overexpression significantly attenuated iron overload and ferroptosis in the miR-4735-3p mimic-treated human ccRCC cell lines. Conclusion. miR-4735-3p facilitates ferroptosis and tumor suppression in ccRCC by targeting SLC40A1.

MicroRNA-299a-5p Protects against Spinal Cord Injury through Activating AMPK Pathway

Objective

Inflammation and oxidative stress are implicated in the pathogenesis of spinal cord injury (SCI). The present study is aimed at investigating the function and molecular basis of microRNA-299a-5p (miR-299a-5p) during SCI in mice.

Methods

Mice were exposed to SCI surgery and then intrathecally injected with the agomir, antagomir, or matched negative controls of miR-299a-5p to overexpress or silence miR-299a-5p. To inhibit AMP-activated protein kinase (AMPK), mice were intraperitoneally injected with compound C (CC). To overexpress pH domain and leucine-rich repeat protein phosphatase 1 (PHLPP1), lentiviral vectors were used.

Results

The miR-299a-5p expression in the spinal cord was dramatically reduced by SCI stimulation. The miR-299a-5p agomir prevents, while the miR-299a-5p antagomir exacerbates inflammation, oxidative stress, and SCI in mice. Mechanistically, we found that miR-299a-5p directly inhibited PHLPP1 and subsequently activated AMPK pathway. The PHLPP1 overexpression of AMPK inhibition with either genetic or pharmacologic methods dramatically abolished the miR-299a-5p agomir-mediated protective effects against SCI.

Conclusion

miR-299a-5p protects against spinal cord injury through activating AMPK pathway.