Gentianella acuta prevents acute myocardial infarction induced by isoproterenol in rats via inhibition of galectin-3/TLR4/MyD88/NF-кB inflammatory signalling

The total xanthones extracted from Gentianella acuta alleviates HFpEF by activating the IRE1α/Xbp1s pathway

Heart failure with preserved ejection fraction (HFpEF) is a clinical syndrome characterized by pulmonary and systemic congestion resulting from left ventricular diastolic dysfunction and increased filling pressure. Currently, however, there is no evidence on effective pharmacotherapy for HFpEF. In this study, we aimed to investigate the therapeutic effect of total xanthones extracted from Gentianella acuta (TXG) on HFpEF by establishing an high-fat diet (HFD) + L-NAME-induced mouse model. Echocardiography was employed to assess the impact of TXG on the cardiac function in HFpEF mice. Haematoxylin and eosin staining, wheat germ agglutinin staining, and Masson's trichrome staining were utilized to observe the histopathological changes following TXG treatment. The results demonstrated that TXG alleviated HFpEF by reducing the expressions of genes associated with myocardial hypertrophy, fibrosis and apoptosis. Furthermore, TXG improved cardiomyocyte apoptosis by inhibiting the expression of apoptosis-related proteins. Mechanistic investigations revealed that TXG could activate the inositol-requiring enzyme 1α (IRE1α)/X-box-binding protein 1 (Xbp1s) signalling pathway, but the knockdown of IRE1α using the IRE1α inhibitor STF083010 or siRNA-IRE1α impaired the ability of TXG to ameliorate cardiac remodelling in HFpEF models. In conclusion, TXG alleviates myocardial hypertrophy, fibrosis and apoptosis through the activation of the IRE1α/Xbp1s signalling pathway, suggesting its potential beneficial effects on HFpEF patients.

Effect of Gentianella acuta (Michx.) Hulten against the arsenic-induced development hindrance of mouse oocytes

The current study was designed to investigate the alleviative effect of Gentianella acuta (Michx.) Hulten (G. acuta) against the sodium arsenite (NaAsO2)-induced development hindrance of mouse oocytes. For this purpose, the in vitro maturation (IVM) of mouse cumulus-oocyte complexes (COCs) was conducted in the presence of NaAsO2 and G. acuta, followed by the assessments of IVM efficiency including oocyte maturation, spindle organization, chromosome alignment, cytoskeleton assembly, cortical granule (CGs) dynamics, redox regulation, epigenetic modification, DNA damage, and apoptosis. Subsequently, the alleviative effect of G. acuta intervention on the fertilization impairments of NaAsO2-exposed oocytes was confirmed by the assessment of in vitro fertilization (IVF). The results showed that the G. acuta intervention effectively ameliorated the decreased maturation potentials and fertilization deficiency of NaAsO2-exposed oocytes but also significantly inhibited the DNA damages, apoptosis, and altered H3K27me3 expression level in the NaAsO2-exposed oocytes. The effective effects of G. acuta intervention against redox dysregulation including mitochondrial dysfunctions, accumulated reactive oxygen species (ROS) generation, glutathione (GSH) deficiency, and decreased adenosine triphosphate (ATP) further confirmed that the ameliorative effects of G. acuta intervention against the development hindrance of mouse oocytes were positively related to the antioxidant capacity of G. acuta. Evidenced by these abovementioned results, the present study provided fundamental bases for the ameliorative effect of G. acuta intervention against the meiotic defects caused by the NaAsO2 exposure, benefiting the future application potentials of G. acuta intervention in these nutritional and therapeutic research for attenuating the outcomes of arseniasis.

MyD88 and Its Inhibitors in Cancer: Prospects and Challenges

The interplay between the immune system and cancer underscores the central role of immunotherapy in cancer treatment. In this context, the innate immune system plays a critical role in preventing tumor invasion. Myeloid differentiation factor 88 (MyD88) is crucial for innate immunity, and activation of MyD88 promotes the production of inflammatory cytokines and induces infiltration, polarization, and immune escape of immune cells in the tumor microenvironment. Additionally, abnormal MyD88 signaling induces tumor cell proliferation and metastasis, which are closely associated with poor prognosis. Therefore, MyD88 could serve as a novel tumor biomarker and is a promising target for cancer therapy. Current strategies targeting MyD88 including inhibition of signaling pathways and protein multimerization, have made substantial progress, especially in inflammatory diseases and chronic inflammation-induced cancers. However, the specific role of MyD88 in regulating tumor immunity and tumorigenic mechanisms remains unclear. Therefore, this review describes the involvement of MyD88 in tumor immune escape and disease therapy. In addition, classical and non-classical MyD88 inhibitors were collated to provide insights into potential cancer treatment strategies. Despite several challenges and complexities, targeting MyD88 is a promising avenue for improving cancer treatment and has the potential to revolutionize patient outcomes.

Leukocyte Ig-like receptor B4 (Lilrb4a) alleviates cardiac dysfunction and isoproterenol-induced arrhythmogenic remodeling associated with cardiac fibrosis and inflammation

BACKGROUND

Heart failure is usually accompanied by activation of the sympathetic nerve, and excessive activation of the sympathetic nerve promotes cardiac remodeling and cardiac dysfunction. In the isoproterenol (ISO)-induced animal model, it is often accompanied by myocardial hypertrophy, fibrosis, and inflammation. Leukocyte immunoglobulin-like receptor B4a (Lilrb4a), an immunosuppressive regulatory receptor, plays a vital role in cardiovascular disease. However, the effect of Lilrb4a on ventricular arrhythmia in an ISO-induced mouse model remains unclear.

OBJECTIVE

The purpose of this study was to explore the role and molecular mechanism of Lilrb4a in ISO-induced arrhythmogenic remodeling.

METHODS

Lilrb4a knockout mice and Lilrb4a overexpression mice were infused with ISO (15 mg/kg per 24 hours, 4 weeks). Echocardiography and histology evaluations of myocardial hypertrophy and cardiac structural remodeling were conducted. Surface electrocardiography and electrophysiologic examination were used to evaluate cardiac electrical remodeling and susceptibility to ventricular arrhythmias. Quantitative reverse transcriptase-polymerase chain reaction analysis and Western blotting were used to detect the expression levels of ion channel proteins and signal pathway proteins.

RESULTS

The results discovered that ISO induced cardiac hypertrophy, fibrosis, and inflammation and led to electrical remodeling and the occurrence of ventricular arrhythmias. Lilrb4a alleviated cardiac structural and electrical remodeling and protected against the occurrence of ventricular arrhythmias in ISO-induced mice by gain-of-function or loss-of-function approaches. The mechanism is that Lilrb4a inhibited NF-κB signaling and MAPK signaling activation mediated by transforming growth factor kinase 1.

CONCLUSION

Lilrb4a alleviates cardiac dysfunction and ISO-induced arrhythmogenic remodeling associated with cardiac fibrosis and inflammation through the regulation of NF-κB signaling and MAPK signaling activation.

Isoproterenol induces MD2 activation by β-AR-cAMP-PKA-ROS signalling axis in cardiomyocytes and macrophages drives inflammatory heart failure

Cardiac inflammation contributes to heart failure (HF) induced by isoproterenol (ISO) through activating β-adrenergic receptors (β-AR). Recent evidence shows that myeloid differentiation factor 2 (MD2), a key protein in endotoxin-induced inflammation, mediates inflammatory heart diseases. In this study, we investigated the role of MD2 in ISO-β-AR-induced heart injuries and HF. Mice were infused with ISO (30 mg·kg-1·d-1) via osmotic mini-pumps for 2 weeks. We showed that MD2 in cardiomyocytes and cardiac macrophages was significantly increased and activated in the heart tissues of ISO-challenged mice. Either MD2 knockout or administration of MD2 inhibitor L6H21 (10 mg/kg every 2 days, i.g.) could prevent mouse hearts from ISO-induced inflammation, remodelling and dysfunction. Bone marrow transplantation study revealed that both cardiomyocyte MD2 and bone marrow-derived macrophage MD2 contributed to ISO-induced cardiac inflammation and injuries. In ISO-treated H9c2 cardiomyocyte-like cells, neonatal rat primary cardiomyocytes and primary mouse peritoneal macrophages, MD2 knockout or pre-treatment with L6H21 (10 μM) alleviated ISO-induced inflammatory responses, and the conditioned medium from ISO-challenged macrophages promoted the hypertrophy and fibrosis in cardiomyocytes and fibroblasts. We demonstrated that ISO induced MD2 activation in cardiomyocytes via β1-AR-cAMP-PKA-ROS signalling axis, and induced inflammatory responses in macrophages via β2-AR-cAMP-PKA-ROS axis. This study identifies MD2 as a key inflammatory mediator and a promising therapeutic target for ISO-induced heart failure.

Bellidifolin ameliorates isoprenaline-induced cardiac hypertrophy by the Nox4/ROS signalling pathway through inhibiting BRD4

To date, there is no effective therapy for pathological cardiac hypertrophy, which can ultimately lead to heart failure. Bellidifolin (BEL) is an active xanthone component of Gentianella acuta (G. acuta) with a protective function for the heart. However, the role and mechanism of BEL action in cardiac hypertrophy remain unknown. In this study, the mouse model of cardiac hypertrophy was established by isoprenaline (ISO) induction with or without BEL treatment. The results showed that BEL alleviated cardiac dysfunction and pathological changes induced by ISO in the mice. The expression of cardiac hypertrophy marker genes, including ANP, BNP, and β-MHC, were inhibited by BEL both in mice and in H9C2 cells. Furthermore, BEL repressed the epigenetic regulator bromodomain-containing protein 4 (BRD4) to reduce the ISO-induced acetylation of H3K122 and phosphorylation of RNA Pol II. The Nox4/ROS/ADAM17 signalling pathway was also inhibited by BEL in a BRD4 dependent manner. Thus, BEL alleviated cardiac hypertrophy and cardiac dysfunction via the BRD4/Nox4/ROS axes during ISO-induced cardiac hypertrophy. These findings clarify the function and molecular mechanism of BEL action in the therapeutic intervention of cardiac hypertrophy.

Gentianella acuta-derived Gen-miR-1 suppresses myocardial fibrosis by targeting HAX1/HMG20A/Smads axis to attenuate inflammation in cardiac fibroblasts

BACKGROUND

Continuous activation and inflammation of cardiac fibroblasts (CFs) are essential for myocardial fibrosis. Gentianella acuta (Michx.) Hiitonen (G. acuta), that contains xanthones with cardioprotective properties, a typical healthful herb extensively used to treat cardiovascular diseases in Inner Mongolia region of China. However, it remains unknown whether or not G. acuta-derived miRNAs can shield CFs from activation by inflammatory stimulation. Therefore, we tend to investigated the role and core mechanism of G. acuta-derived Gen-miR-1 in regulating fibrosis and inflammation induced by TGF-β1.

METHODS

An animal model for myocardial infarction was built by subcutaneous injections of ISO and treated with Gen-miR-1 using intragastric administration. The protective effect of Gen-miR-1 on the heart was assessed by pathomorphological analysis of myocardial fibrosis. Using loss- and gain-of-function approaches, Gen-miR-1 regulation of HAX1/HMG20A/Smads axis was investigated by utilizing luciferase assay, Western blot, co-immunoprecipitation, etc. RESULTS: Screened and identified Gen-miR-1 from G. acuta. Gen-miR-1 can enter the mouse body, and markedly inhibit myocardial infarction induced by ISO in mice, as well as suppresses fibrosis in CFs and attenuates the inflammatory response elicited by TGF-β1 in vitro. Gen-miR-1 downregulates HCLS1-related Protein X-1 (HAX1) expression through direct binding to the 3' UTR of HAX1, which in turn relieves HAX1 from promoting the expression of high-mobility group protein 20A (HMG20A), whereas HMG20A downregulation restrains the activation of TGF-β1/Smads signaling pathways, subsequently resulting in a decrease of fibrosis and in facilitating CFs anti-inflammatory effects induced by Gen-miR-1 in the context of CFs activation induced by TGF-β1.

CONCLUSIONS

Our results first uncovered unique bioactive components in G. acuta and elucidated the molecular mechanism by which G. acuta-derived Gen-miR-1 suppress inflammation and myocardial fibrosis. These findings expand our understanding of G. acuta's therapeutic properties and bioactive constituents. Gen-miR-1-regulated HAX1/HMG20A/Smads axis will be one potential therapeutic target for cardiac remodeling.

Chronic high-fat diet induces galectin-3 and TLR4 to activate NLRP3 inflammasome in NASH

NOD-like receptor protein 3 (NLRP3) inflammasome activation triggers inflammation progression in some metabolism disorders, frequently accompanying the up-regulation of galectin-3 (Gal-3). However, the precise mechanisms of Gal-3 activating NLRP3 inflammasome remain unclear in nonalcoholic steatohepatitis (NASH). Here, male C57BL/6J mice were fed by high-fat diet (HFD) for 32 weeks to induce NASH and then the hepatic damage, cytokines, Gal-3 and TLR4 expression, and NLRP3 inflammasome activation were examined. Such indicators were similarly determined when HepG2 cells were co-incubated with palmitic acid (PA, 200 μM), β-lactose, and TAK-242, or pre-transfected with TLR4. Immunofluorescence, immunohistochemistry, and co-immunoprecipitation were conducted to confirm the potential interaction between Gal-3 and TLR4. To further identify the inflammatory regulation roles of Gal-3 and its terminals in TLR4/NLRP3, HepG2 cells were transfected with Gal-3 and its variants. Chronic HFD induced sustained hepatic steatosis and inflammatory injury, with increased inflammatory cytokines, Gal-3 and TLR4 expression, and NLRP3 inflammasome activation. Similar changes were found in PA-dosed HepG2 cells, which were rescued by β-lactose but deteriorated with TLR4 overexpression. However, TAK-242 treatment decreased AST, ALT, cytokines, and normalized NLRP3, caspase-1, and ASC expression. Furthermore, TLR4 was pulled down when Gal-3 was enriched. Only full-length Gal-3 and its carbohydrate recognition domain (CRD) promoted cytokines, TLR4 expression, and NLRP3 inflammasome activation. Thus, gal-3 may induce chronic HFD-derived NASH progression by activating TLR4-mediating NLRP3 inflammasome via its CRD, which sheds new light on candidate target for the treatment and prevention of NASH inflammation despite further research for its precise roles in the future.

The interplay of galectins-1, -3, and -9 in the immune-inflammatory response underlying cardiovascular and metabolic disease

Galectins are β-galactoside-binding proteins that bind and crosslink molecules via their sugar moieties, forming signaling and adhesion networks involved in cellular communication, differentiation, migration, and survival. Galectins are expressed ubiquitously across immune cells, and their function varies with their tissue-specific and subcellular location. Particularly galectin-1, -3, and -9 are highly expressed by inflammatory cells and are involved in the modulation of several innate and adaptive immune responses. Modulation in the expression of these proteins accompany major processes in cardiovascular diseases and metabolic disorders, such as atherosclerosis, thrombosis, obesity, and diabetes, making them attractive therapeutic targets. In this review we consider the broad cellular activities ascribed to galectin-1, -3, and -9, highlighting those linked to the progression of different inflammatory driven pathologies in the context of cardiovascular and metabolic disease, to better understand their mechanism of action and provide new insights into the design of novel therapeutic strategies.

Network Pharmacology-Based Combined with Experimental Validation Study to Explore the Underlying Mechanism of Agrimonia pilosa Ledeb. Extract in Treating Acute Myocardial Infarction

Purpose

The network pharmacology approach and validation experiment were performed to investigate the potential mechanisms of Agrimonia pilosa Ledeb. (APL) extract against acute myocardial infarction (AMI).

Methods

The primary compounds of APL extract were identified by High-Performance Liquid Chromatography (HPLC) analysis. The intersecting targets of active compounds and AMI were determined via network pharmacology analysis. A mouse model of AMI was established by subcutaneous injection of isoproterenol (Iso). Mice were treated with APL extract by intragastric administration. We assessed the effects of APL extract on the electrocardiography (ECG), cardiac representative markers, representative indicators of oxidative stress, pathological changes, and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, as well as apoptosis-related indicators in the mice.

Results

Five candidate compounds were identified in APL extract. Enrichment analyses indicated that APL extract could exert myocardial protective effects via the PI3K/Akt pathway. ST segment elevation and increased heart rate were obviously reversed in APL extract groups compared to Iso group. We also detected significant decreases in lactate dehydrogenase (LDH), creatine kinase (CK), creatine kinase MB (CK-MB), malondialdehyde (MDA), and reactive oxygen species (ROS), as well as a significant increase in superoxide dismutase activities (SOD) after APL extract treatment. In addition, APL extract markedly decreased the number of apoptotic cardiomyocytes after AMI. In the APL extract groups of AMI mice, there were increased expression levels of p-PI3K, p-Akt, and B-cell lymphoma-2 (Bcl-2) protein, and there were decreases in Bcl-2-associated X (Bax), cysteinyl aspartate-specific proteases-3 (caspase-3), and cleaved-caspase-3 protein expression levels, as well as the Bax/Bcl-2 ratio.

Conclusion

APL extract had a protective effect against Iso-induced AMI. APL extract could ameliorate AMI through antioxidant and anti-apoptosis actions which may be associated with the activation of the PI3K/Akt signaling pathway.

Gentianella acuta improves TAC-induced cardiac remodelling by regulating the Notch and PI3K/Akt/FOXO1/3 pathways

Cardiac remodelling mainly manifests as excessive myocardial hypertrophy and fibrosis, which are associated with heart failure. Gentianella acuta (G. acuta) is reportedly effective in cardiac protection; however, the mechanism by which it protects against cardiac remodelling is not fully understood. Here, we discuss the effects and mechanisms of G. acuta in transverse aortic constriction (TAC)-induced cardiac remodelling in rats. Cardiac function was analysed using echocardiography and electrocardiography. Haematoxylin and eosin, Masson's trichrome, and wheat germ agglutinin staining were used to observe pathophysiological changes. Additionally, real-time quantitative reverse transcription polymerase chain reaction and western blotting were used to measure protein levels and mRNA levels of genes related to myocardial hypertrophy and fibrosis. Immunofluorescence double staining was used to investigate the co-expression of endothelial and interstitial markers. Western blotting was used to estimate the expression and phosphorylation levels of the regulatory proteins involved in autophagy and endothelial-mesenchymal transition (EndMT). The results showed that G. acuta alleviated cardiac dysfunction and remodelling. The elevated levels of myocardial hypertrophy and fibrosis markers, induced by TAC, decreased significantly after G. acuta intervention. G. acuta decreased the expression of LC3 II and Beclin1, and increased p62 expression. G. acuta upregulated the expression of CD31 and vascular endothelial-cadherin, and prevented the expression of α-smooth muscle actin and vimentin. Furthermore, G. acuta inhibited the PI3K/Akt/FOXO1/3a pathway and activated the Notch signalling. These findings demonstrated that G. acuta has cardioprotective effects, such as alleviating myocardial fibrosis, inhibiting hypertrophy, reducing autophagy, and blocking EndMT by regulating the PI3K/Akt/FOXO1/3a and Notch signalling pathways.

Potential therapeutic strategies for myocardial infarction: the role of Toll-like receptors

Myocardial infarction (MI) is a life-threatening condition among patients with cardiovascular diseases. MI increases the risk of stroke and heart failure and is a leading cause of morbidity and mortality worldwide. Several genetic and epigenetic factors contribute to the development of MI, suggesting that further understanding of the pathomechanism of MI might help in the early management and treatment of this disease. Toll-like receptors (TLRs) are well-known members of the pattern recognition receptor (PRR) family and contribute to both adaptive and innate immunity. Collectively, studies suggest that TLRs have a cardioprotective effect. However, prolonged TLR activation in the response to signals generated by damage-associated molecular patterns (DAMPs) results in the release of inflammatory cytokines and contributes to the development and exacerbation of myocardial inflammation, MI, ischemia-reperfusion injury, myocarditis, and heart failure. The objective of this review is to discuss and summarize the association of TLRs with MI, highlighting their therapeutic potential for the development of advanced TLR-targeted therapies for MI.

Signaling pathways and targeted therapy for myocardial infarction

Although the treatment of myocardial infarction (MI) has improved considerably, it is still a worldwide disease with high morbidity and high mortality. Whilst there is still a long way to go for discovering ideal treatments, therapeutic strategies committed to cardioprotection and cardiac repair following cardiac ischemia are emerging. Evidence of pathological characteristics in MI illustrates cell signaling pathways that participate in the survival, proliferation, apoptosis, autophagy of cardiomyocytes, endothelial cells, fibroblasts, monocytes, and stem cells. These signaling pathways include the key players in inflammation response, e.g., NLRP3/caspase-1 and TLR4/MyD88/NF-κB; the crucial mediators in oxidative stress and apoptosis, for instance, Notch, Hippo/YAP, RhoA/ROCK, Nrf2/HO-1, and Sonic hedgehog; the controller of myocardial fibrosis such as TGF-β/SMADs and Wnt/β-catenin; and the main regulator of angiogenesis, PI3K/Akt, MAPK, JAK/STAT, Sonic hedgehog, etc. Since signaling pathways play an important role in administering the process of MI, aiming at targeting these aberrant signaling pathways and improving the pathological manifestations in MI is indispensable and promising. Hence, drug therapy, gene therapy, protein therapy, cell therapy, and exosome therapy have been emerging and are known as novel therapies. In this review, we summarize the therapeutic strategies for MI by regulating these associated pathways, which contribute to inhibiting cardiomyocytes death, attenuating inflammation, enhancing angiogenesis, etc. so as to repair and re-functionalize damaged hearts.

Modified citrus pectin prevents isoproterenol-induced cardiac hypertrophy associated with p38 signalling and TLR4/JAK/STAT3 pathway

Modified citrus pectin (MCP) is a specific inhibitor of galectin-3 (Gal-3) that is regarded as a new biomarker of cardiac hypertrophy, but its effect is unclear. The aim of this study is to investigate the role and mechanism of MCP in isoproterenol (ISO)-induced cardiac hypertrophy. Rats were injected with ISO to induce cardiac hypertrophy and treated with MCP. Cardiac function was detected by ECG and echocardiography. Pathomorphological changes were evaluated by the haematoxylin eosin (H&E) and wheat germ agglutinin (WGA) staining. The hypertrophy-related genes for atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and β-myosin heavy chain (β-MHC), and the associated signal molecules were analysed by qRT-PCR and western blotting. The results show that MCP prevented cardiac hypertrophy and ameliorated cardiac dysfunction and structural disorder. MCP also decreased the levels of ANP, BNP, and β-MHC and inhibited the expression of Gal-3 and Toll-like receptor 4 (TLR4). Additionally, MCP blocked the phosphorylation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3), but it promoted the phosphorylation of p38. Thus, MCP prevented ISO-induced cardiac hypertrophy by activating p38 signalling and inhibiting the Gal-3/TLR4/JAK2/STAT3 pathway.

Identification of important genes related to ferroptosis and hypoxia in acute myocardial infarction based on WGCNA

Acute myocardial infarction (AMI) tends to cause severe heart failure and the population suffering from AMI gradually become younger. This study aims to determine the key genes associated with AMI, ferroptosis and hypoxia that could serve as novel biomarkers for AMI. There were 522 up-regulated genes and 119 down-regulated genes in GSE4648. Based on the expression of ferroptosis-related genes (FRGs) and hypoxia-related genes, the ferroptosis Z-score and the hypoxia Z-score calculated by ssGSEA were significantly higher in the infarcted area of AMI mice than in the control group, and there was a positive correlation between ferroptosis and hypoxia Z-score. 6 modules were obtained by Weighted Gene Co-Expression Network Analysis (WGCNA), and 2 key modules and 66 key genes were screened out. Genes in the key modules were found mainly related to ERK1 and ERK2 cascade, TNF signaling pathway, and MAPK signaling pathway through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Protein-protein interaction (PPI) network analysis was performed on the key genes and 10 hub genes (Atf3, Ptgs2, Cxcl1, Socs3, Hspa1b, Selp, Cxcl2, Il1b, Myd88, and S100a8) were obtained using STRING and Cytohubba. The expression of 9 hub genes except Cxcl1 was consistent in GSE4648 and GSE775. The transcription factors (TFs)-hub genes interaction network was constructed and 48 TFs were obtained using TRRUST. Finally, it was verified through the animal experiment that these hub genes were up-regulated in AMI mice myocardial tissues. This study offers new ideas for the diagnosis and treatment of AMI.

Astragaloside IV prevents acute myocardial infarction by inhibiting the TLR4/MyD88/NF-κB signaling pathway

Although astragaloside IV protects from acute myocardial infarction (AMI)-induced chronic heart failure (CHF), the underlying mechanism of action is unclear. We determined the potential therapeutic effect of astragaloside IV using molecular docking approaches and validated the findings by the ligation of the left anterior descending (LAD) coronary artery-induced AMI rat model. The interaction between astragaloside IV and myeloid differentiation factor 88 (MyD88) was evaluated by SwissDock. To explore the mechanisms underlying the beneficial effects of astragaloside IV in the LAD coronary artery ligation-induced AMI model, we administered the rats with astragaloside IV for 4 weeks. Hemodynamic indexes were used to evaluate the degree of myocardial injury in model rats. The histopathological changes in myocardium were detected by hematoxylin & eosin (H&E) staining and Masson's staining. Myocardium homogenate contents of collagen I and collagen III were evaluated by ELISA. The level of myocardial hydroxyproline (HYP) was determined by alkaline hydrolysis. Immunohistochemistry was used to examine collagen I. Western blotting was used to examine relevant proteins. As per the molecular docking study results, astragaloside IV may act on MyD88. Furthermore, astragaloside IV improved hemodynamic disorders, alleviated pathological changes, and reduced abnormal collagen deposition and myocardial HYP in vivo. Astragaloside IV significantly reduced the overexpression of TLR4, MyD88, NF-Κb, and TGF-β, which further validated the molecular docking findings. Hence, astragaloside IV ameliorates AMI by reducing inflammation and blocking TLR4/MyD88/NF-κB signaling. These results indicate that astragaloside IV may alleviate AMI. PRACTICAL APPLICATIONS: Astragaloside IV, a small active substance extracted from Astragalus membranaceus, has demonstrated potent protective effects against cardiovascular ischemia/reperfusion, diabetic nephropathy, and other diseases. Molecular docking experiments showed that astragaloside IV might act on the myeloid differentiation factor 88 (MyD88). Astragaloside IV can effectively reduce the overexpression of TLR4, MyD88, and NF-κB p65, indicating that astragaloside IV inhibits inflammation via TLR4/MyD88/NF-κB signaling pathway. These results indicate that astragaloside IV may alleviate acute myocardial infarction.

Bellidifolin Ameliorates Isoprenaline-Induced Myocardial Fibrosis by Regulating TGF-β1/Smads and p38 Signaling and Preventing NR4A1 Cytoplasmic Localization

Myocardial fibrosis is closely related to high morbidity and mortality. In Inner Mongolia, Gentianella amarella subsp. acuta (Michx.) J.M.Gillett (G. acuta) is a kind of tea used to prevent cardiovascular diseases. Bellidifolin (BEL) is an active xanthone molecule from G. acuta that protects against myocardial damage. However, the effects and mechanisms of BEL on myocardial fibrosis have not been reported. In vivo, BEL dampened isoprenaline (ISO)-induced cardiac structure disturbance and collagen deposition. In vitro, BEL inhibited transforming growth factor (TGF)-β1-induced cardiac fibroblast (CF) proliferation. In vivo and in vitro, BEL decreased the expression of α-smooth muscle actin (α-SMA), collagen Ⅰ and Ⅲ, and inhibited TGF-β1/Smads signaling. Additionally, BEL impeded p38 activation and NR4A1 (an endogenous inhibitor for pro-fibrogenic activities of TGF-β1) phosphorylation and inactivation in vitro. In CFs, inhibition of p38 by SB203580 inhibited the phosphorylation of NR4A1 and did not limit Smad3 phosphorylation, and blocking TGF-β signaling by LY2157299 and SB203580 could decrease the expression of α-SMA, collagen I and III. Overall, both cell and animal studies provide a potential role for BEL against myocardial fibrosis by inhibiting the proliferation and phenotypic transformation of CFs. These inhibitory effects might be related to regulating TGF-β1/Smads pathway and p38 signaling and preventing NR4A1 cytoplasmic localization.