Interleukin-34-NF-κB signaling aggravates myocardial ischemic/reperfusion injury by facilitating macrophage recruitment and polarization

Multiple omics-based machine learning reveals specific macrophage sub-clusters in renal ischemia-reperfusion injury and constructs predictive models for transplant outcomes

BACKGROUND

Ischemia-reperfusion injury (IRI) is closely associated with numerous severe postoperative complications, including acute rejection, delayed graft function (DGF) and graft failure. Macrophages are central to modulating the aseptic inflammatory response during the IRI process. The objective of this study is to conduct an analysis of the developmental and differentiation characteristics of macrophages in IRI, identify distinct molecules subtypes of IRI, and establish robust predictive strategies for DGF and graft survival.

METHOD

We analyzed scRNA-Seq data from GEO database to identify macrophage sub-clusters specific to renal IRI, and use the hdWGCNA algorithm to screen gene modules closely associated with this sub-cluster. Integrating these module genes with the results from bulk RNA-Seq differential analysis to obtain hub genes, and delineating the different IRI molecular subtypes through consensus clustering based on the expression profiles of hub genes. Innovatively, the gene expression matrix was transformed into a unique graphic pixel module and applied advanced computer vision processing algorithms to construct a DGF predictive model. Additionally, we also employed 111 combinations of 10 machine learning algorithms to develop a predictive signature for graft survival. Finally, we validated the expression of the key gene ANXA1 in a mouse IRI model using qRT-PCR, WB, and IHC.

RESULT

This study successfully identified a subset of macrophages closely associated with renal IRI, and cell communication and pseudo-time analysis implied that they may be instrumental in both the maintenance and exacerbation of the IRI process. Utilizing the expression patterns of hub genes, recipients can be clustered into two subtypes (CI and C2) with unique clinical and molecular features. We innovatively applied deep learning algorithms to construct a model for DGF prediction, which can effectively mitigate batch effects among IRI recipients. Compared to other existing models, our model demonstrated superior performance with AUC of 0.816 and 0.845 in the training and validation set. Furthermore, we also used the random survival forest algorithm to develop a high-precision predictive signature for graft failure. The mouse IRI model confirmed a marked upregulation of ANXA1 mRNA and protein expression in renal tissue following IRI.

CONCLUSION

This study successfully revealed the macrophage sub-cluster closely associated with renal IRI. Two distinct IRI subgroups with different characteristics were identified and robust strategies were constructed for predicting DGF and graft survival, which can offer potential therapeutic targets for the treatment of IRI and reference for early prevention of various postoperative complications.

Mitochondrial dynamics and metabolism in macrophages for cardiovascular disease: A review

BACKGROUND

Mitochondria regulate macrophage function, affecting cardiovascular diseases like atherosclerosis and heart failure. Their dynamics interact with macrophage cell death mechanisms, including apoptosis and necroptosis.

PURPOSE

This review explores how mitochondrial dynamics and metabolism influence macrophage inflammation and cell death in CVDs, highlighting therapeutic targets for enhancing macrophage resilience and reducing CVD pathology, while examining molecular pathways and pharmacological agents involved.

STUDY DESIGN

This is a narrative review that integrates findings from various studies on mitochondrial dynamics and metabolism in macrophages, their interactions with the endoplasmic reticulum (ER) and Golgi apparatus, and their implications for CVDs. The review also considers the potential therapeutic effects of pharmacological agents on these pathways.

METHODS

The review utilizes a comprehensive literature search to identify relevant studies on mitochondrial dynamics and metabolism in macrophages, their role in CVDs, and the effects of pharmacological agents on these pathways. The selected studies are analyzed and synthesized to provide insights into the complex relationships between mitochondria, the ER, and Golgi apparatus, and their implications for macrophage function and fate.

RESULTS

The review reveals that mitochondrial metabolism intertwines with cellular architecture and function, particularly through its intricate interactions with the ER and Golgi apparatus. Mitochondrial-associated membranes (MAMs) facilitate Ca2+ transfer from the ER to mitochondria, maintaining mitochondrial homeostasis during ER stress. The Golgi apparatus transports proteins crucial for inflammatory signaling, contributing to immune responses. Inflammation-induced metabolic reprogramming in macrophages, characterized by a shift from oxidative phosphorylation to glycolysis, underscores the multifaceted role of mitochondrial metabolism in regulating immune cell polarization and inflammatory outcomes. Notably, mitochondrial dysfunction, marked by heightened reactive oxygen species generation, fuels inflammatory cascades and promotes cell death, exacerbating CVD pathology. However, pharmacological agents such as Metformin, Nitazoxanide, and Galanin emerge as potential therapeutic modulators of these pathways, offering avenues for mitigating CVD progression.

CONCLUSION

This review highlights mitochondrial dynamics and metabolism in macrophage inflammation and cell death in CVDs, suggesting therapeutic targets to improve macrophage resilience and reduce pathology, with new pharmacological agents offering treatment opportunities.

Characterising Shared and Specific Cell-Cell Communication in Cardiomyopathy Subtypes From Single-Cell Transcriptomics Data

Cardiomyopathy encompasses a diverse range of conditions characterised by extensive molecular heterogeneity, particularly the variations in cell-cell communication events such as ligand-receptor interactions and downstream signalling. Understanding the common and unique features of these intercellular interactions is crucial for advancing targeted treatments. We analysed single-cell RNA sequencing datasets from the ventricular regions of patients with arrhythmogenic cardiomyopathy (ACM), dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM) and healthy donors (HD), as well as ischemic cardiomyopathy (ICM). Our analyses focused on cell type-specific disease preferences, differential gene expression, pathway enrichment and particularly cell-cell communication. We observed that inflammatory, autoimmune, angiogenesis, lymphangiogenesis and fibrotic extracellular matrix deposition are consistently enriched across all four disease subtypes, highlighting their universal significance in disease progression through intercellular interactions. Additionally, we identified subtype-specific pathways that reflect distinct intercellular communication patterns unique to each disease subtype: arrhythmia-associated pathways in ACM, chronic inflammation-related pathways in DCM, ECM remodelling pathways in HCM and ischaemic injury and recovery pathways in ICM.

The role of Fusobacterium nucleatum in macrophage M2 polarization and NF-κB pathway activation in colorectal cancer

Fusobacterium nucleatum is strongly linked to colorectal cancer (CRC) progression, but its mechanisms for influencing macrophage polarization and tumor development are not well understood. We established an in vitro model of F. nucleatum infection in RAW264.7 macrophages to investigate these processes. Macrophage polarization was evaluated using scanning electron microscopy (SEM), real-time quantitative PCR (RT-qPCR), and immunofluorescence staining. RNA sequencing (RNA-Seq) identified differentially expressed genes (DEGs) and enriched pathways, focusing on the role of the NF-κB signaling pathway in macrophage polarization. F. nucleatum infection induced M2 polarization in RAW264.7 macrophages, as confirmed by SEM analysis and RT-qPCR validation. A total of 2,029 DEGs were identified after F. nucleatum infection, with 763 upregulated and 1,266 downregulated. GO and KEGG enrichment analysis showed that cytokine-cytokine receptor interaction, TNF signaling, and NF-κB signaling pathways are upregulated in macrophages after F. nucleatum infection, indicating enhanced cytokine activity and immune response. Key genes (Nfkb1, Nfkb2, Malt, Lta, Ltb, Tnf) and proteins (P50, P100) in the NF-κB pathway are upregulated, indicating the crucial role of the NF-κB pathway in M2 macrophage polarization. This study offers crucial evidence regarding the role of the NF-κB signaling pathway in modulating F. nucleatum-induced macrophage M2 polarization, underscoring its significance in the progression of colorectal cancer.

Liriodendrin alleviates myocardial ischemia‑reperfusion injury via partially attenuating apoptosis, inflammation and mitochondria damage in rats

Myocardial ischemia‑reperfusion (I/R) injury may lead to dysfunction of signaling pathways related to cell apoptosis, inflammation, oxidative stress, and mitochondrial damage. The present study investigated the defensive effect of liriodendrin, as a natural product isolated from Linaria vulgaris, on reperfusion injury in rats and the underlying mechanisms involved in this process. An in vivo rat model of I/R constructed by ligation of the left anterior descending artery, as well as an in vitro model using H9C2 cells under hypoxic conditions, was established to assess the cardioprotective effects of liriodendrin. The biomarkers of myocardial damage, oxidative stress, and inflammatory response were measured with enzyme‑linked immunosorbent assay (ELISA). Gene and protein expression were detected by reverse transcription‑quantitative PCR (RT‑qPCR) and western blotting. Mitochondrial morphology was observed by electron microscopy. The levels of creatine kinase isoenzymes and cardiac troponin T were significantly elevated in the I/R compared with the sham group; liriodendrin mitigated this elevation. The liriodendrin group exhibited a significant reduction in myocardial tissue apoptosis, as indicated by immunohistochemical staining and western blotting. Additionally, ELISA indicated that the I/R group had higher levels of reactive oxygen species (ROS) compared with the liriodendrin group, while the liriodendrin group had higher levels of superoxide dismutase. The in vitro experiments demonstrated that liriodendrin ameliorated hypoxia‑induced injury to mitochondria and suppressed the activation of nuclear factor-κB and B-cell lymphoma-2 associated X protein (Bax). Therefore, the present study demonstrated that liriodendrin impeded ROS‑associated metabolic disorders, maintained mitochondrial homeostasis and partially alleviated cardiomyocyte apoptosis by inhibiting the Bax signaling pathway.

Knockdown of TSP-4 alleviates MI/RI-induced myocardial injury and improves brain inflammation by enhancing blood-brain barrier stability

Myocardial ischemia-reperfusion injury (MI/RI) not only affects cardiac function but also has significant implications for neurological health, potentially leading to cognitive and behavioral impairments. At present, the regulatory role of thrombospondin-4 (TSP-4) in MI/RI has not been reported. A MI/RI mouse model was constructed, and primary cardiomyocytes were isolated. An MI/RI in vitro cell model was constructed using hypoxia/reoxygenation (H/R)-induced H9c2 cells. Haematoxylin and eosin and Masson staining were performed to observe morphological differentiation and fibrosis in myocardial tissues. Evans blue staining was used to analyse blood-brain barrier (BBB) permeability. Behavioural experiments were conducted to assess the learning and cognitive functions of mice. The results showed that the expression of TSP-4 was significantly increased in the blood of patients with ischemic cardiomyopathy and in the myocardial tissue of MI/RI mice. Functional studies showed that TSP knockdown alleviated H/R-induced H9c2 cell injury, including inflammation and oxidative stress. Importantly, interference with TSP-4 alleviated myocardial dysfunction in MI/RI mice. Mechanistically, by improving BBB stability, TSP-4 knockdown alleviated neuronal injury and the inflammatory response in mice induced by MI/RI. Further research found that silencing TSP-4 alleviated cognitive impairment and improved learning in MI/RI mice. Knockdown of TSP-4 improved MI/RI-induced functional cardiomyocyte injury. In addition, by enhancing BBB stability, TSP-4 silencing alleviated MI/RI-induced neurological injury and cognitive impairment in mice.

Tissue macrophages: origin, heterogenity, biological functions, diseases and therapeutic targets

Macrophages are immune cells belonging to the mononuclear phagocyte system. They play crucial roles in immune defense, surveillance, and homeostasis. This review systematically discusses the types of hematopoietic progenitors that give rise to macrophages, including primitive hematopoietic progenitors, erythro-myeloid progenitors, and hematopoietic stem cells. These progenitors have distinct genetic backgrounds and developmental processes. Accordingly, macrophages exhibit complex and diverse functions in the body, including phagocytosis and clearance of cellular debris, antigen presentation, and immune response, regulation of inflammation and cytokine production, tissue remodeling and repair, and multi-level regulatory signaling pathways/crosstalk involved in homeostasis and physiology. Besides, tumor-associated macrophages are a key component of the TME, exhibiting both anti-tumor and pro-tumor properties. Furthermore, the functional status of macrophages is closely linked to the development of various diseases, including cancer, autoimmune disorders, cardiovascular disease, neurodegenerative diseases, metabolic conditions, and trauma. Targeting macrophages has emerged as a promising therapeutic strategy in these contexts. Clinical trials of macrophage-based targeted drugs, macrophage-based immunotherapies, and nanoparticle-based therapy were comprehensively summarized. Potential challenges and future directions in targeting macrophages have also been discussed. Overall, our review highlights the significance of this versatile immune cell in human health and disease, which is expected to inform future research and clinical practice.

Immune checkpoint inhibitors mediate myocarditis by promoting macrophage polarization via cGAS/STING pathway

BACKGROUND

Immune checkpoint inhibitors has opened up new avenues for cancer treatment, but serious cardiac injury has emerged in their use. A large number of data have shown that abnormal activation of cytosolic DNA-sensing cyclic GMP-AMP synthase-interferon gene activator pathway is closely related to cardiovascular inflammation and autoimmune diseases. However, the pathophysiological function of the cGAS-STING cascade in myocarditis induced by Immune checkpoint inhibitors is unclear.

METHODS

In order to establish a Immune checkpoint inhibitors-associated myocarditis model, BALB/c mice were injected with mouse cardiac troponin I peptide and anti-mouse programmed death 1 antibody. Echocardiography and HE staining were then performed to assess cardiac function and inflammation. Macrophages and damaged DNA in mouse heart tissue were detected by immunofluorescence. The mitochondrial damage of macrophages was observed by electron microscope. In vitro experiments, RAW264.7 was used to detect macrophage polarization after anti-PD-1 antibody induction and STING inhibition by qPCR and flow cytometry. Mitochondrial damage was detected by immunofluorescence, and activation of the cGAS-STING signaling pathway was evaluated by protein imprinting analysis.

RESULTS

In the Immune checkpoint inhibitors-associated myocarditis model, DNA damage was found to activate the cGAS-STING pathway and macrophages were polarized to M1 type. In vitro experiments, anti-PD-1 antibody activate the cGAS-STING pathway through the release of damaged DNA from macrophage mitochondrial damage, causing macrophage polarization into a pro-inflammatory phenotype leading to autoimmune myocarditis.

CONCLUSION

Our results suggested that the cGAS-STING pathway played a key role in myocarditis caused by immune checkpoint inhibitors. It provided a new possibility for Immune checkpoint inhibitors to be widely used in clinic.

Decoding the cytokine code for heart failure based on bioinformatics, machine learning and Bayesian networks

BACKGROUND

Despite maximal pharmacological treatment guided by clinical guidelines, the prognosis of heart failure (HF) remains poor, posing a significant public health burden. This necessitates uncovering novel pathological and cardioprotective pathways. Targeting cytokines presents a promising therapeutic strategy for HF, yet their intricate mechanisms in HF progression remain obscure.

METHODS

HF datasets were obtained from the GEO database. Cytokine-related genes were identified through WGCNA and the CytReg database. GO and KEGG enrichment analyses were conducted using the clusterProfiler package. Reactome pathway enrichment analysis and Bayesian regulatory network construction were performed using the CBNplot package. Key genes were identified via LASSO regression and RF algorithms, with diagnostic accuracy evaluated by ROC curves. Potential therapeutic drugs were predicted using the DSigDB database, and immune cell infiltration was assessed with the CIBERSORT package.

RESULTS

We identified 13 cytokine-related genes associated with HF. Enrichment analyses indicated these genes mediate inflammatory responses and immune cell recruitment. Bayesian network analysis revealed two cytokine regulatory chains: IL34-CCL5-CCL4 and IL34-CCL5-CXCL12. Machine learning algorithms identified five key cytokine genes: CCL4, CCL5, CXCL12, CXCL14, and IL34. The DSigDB database predicted 47 potential therapeutic drugs, including Proscillaridin. Immune infiltration analysis showed significant differences in seven immune cell types between HF and healthy samples.

CONCLUSION

Our study provides insights into cytokines' molecular mechanisms in HF pathophysiology and highlights potential immunomodulatory strategies, gene therapies, and candidate drugs. Future research should validate these findings in clinical settings to develop effective HF therapies.

Redox imbalance driven epigenetic reprogramming and cardiovascular dysfunctions: phytocompounds for prospective epidrugs

BACKGROUND

Cardiovascular diseases (CVDs) are the major contributor to global mortality and are gaining incremental attention following the COVID-19 outbreak. Epigenetic events such as DNA methylation, histone modifications, and non-coding RNAs have a significant impact on the incidence and onset of CVDs. Altered redox status is one of the major causative factors that regulate epigenetic pathways linked to CVDs. Various bioactive phytocompounds used in alternative therapies including Traditional Chinese Medicines (TCM) regulate redox balance and epigenetic phenomena linked to CVDs. Phytocompound-based medications are in the limelight for the development of cost-effective drugs with the least side effects, which will have immense therapeutic applications.

PURPOSE

This review comprehends certain risk factors associated with CVDs and triggered by oxidative stress-driven epigenetic remodelling. Further, it critically evaluates the pharmacological efficacy of phytocompounds as inhibitors of HAT/HDAC and DNMTs as well as miRNAs regulator that lowers the incidence of CVDs, aiming for new candidates as prospective epidrugs.

METHODS

PRISMA flow approach has been adopted for systematic literature review. Different Journals, computational databases, search engines such as Google Scholar, PubMed, Science Direct, Scopus, and ResearchGate were used to collect online information for literature survey. Statistical information collected from the World Health Organization (WHO) site (https://www.who.int/news-room/fact-sheets/detail/cardiovascular-diseases-(cvds)) and the American Heart Association of Heart Disease and Stroke reported the international and national status of CVDs.

RESULTS

The meta-analysis of various studies is elucidated in the literature, shedding light on major risk factors such as socioeconomic parameters, which contribute highly to redox imbalance, epigenetic modulations, and CVDs. Going forward, redox imbalance driven epigenetic regulations include changes in DNA methylation status, histone modifications and non-coding RNAs expression pattern which further regulates global as well as promoter modification of various transcription factors leading to the onset of CVDs. Further, the role of various bioactive compounds used in herbal medicine, including TCM for redox regulation and epigenetic modifications are discussed. Pharmacological safety doses and different phases of clinical trials of these phytocompounds are elaborated on, which shed light on the acceptance of these phytocompounds as prospective drugs.

CONCLUSION

This review suggests a strong linkage between therapeutic and preventive measures against CVDs by targeting redox imbalance-driven epigenetic reprogramming using phytocompounds as prospective epidrugs. Future in-depth research is required to evaluate the possible molecular mechanisms behind the phytocompound-mediated epigenetic reprogramming and oxidative stress management during CVD progression.

Complex regulation of cardiac fibrosis: insights from immune cells and signaling pathways

Cardiac fibrosis is a physiological process that involves the formation of scar tissue in the heart in response to injury or damage. This process is initially a protective measure characterized by enhanced fibroblasts, which are responsible for producing extracellular matrix proteins that provide structural support to the heart. However, when fibrosis becomes excessive, it can lead to adverse outcomes, including increasing tissue stiffness and impaired cardiac function, which can ultimately result in heart failure with a poor prognosis. While fibroblasts are the primary cells involved in cardiac fibrosis, immune cells have also been found to play a vital role in its progression. Recent research has shown that immune cells exert multifaceted effects besides regulation of inflammatory response. Advanced research techniques such as single-cell sequencing and multiomics have provided insights into the specific subsets of immune cells involved in fibrosis and the complex regulation of the process. Targeted immunotherapy against fibrosis is gaining traction as a potential treatment option, but it is still unclear how immune cells achieve this regulation and whether distinct subsets are involved in different roles. To better understand the role of immune cells in cardiac fibrosis, it is essential to examine the classical signaling pathways that are closely related to fibrosis formation. We have also focused on the unique properties of diverse immune cells in cardiac fibrosis and their specific intercommunications. Therefore, this review will delve into the plasticity and heterogeneity of immune cells and their specific roles in cardiac fibrosis, which propose insights to facilitate the development of anti-fibrosis therapeutic strategies.

The role and therapeutic targeting of the CCL2/CCR2 signaling axis in inflammatory and fibrotic diseases

CCL2, a pivotal cytokine within the chemokine family, functions by binding to its receptor CCR2. The CCL2/CCR2 signaling pathway plays a crucial role in the development of fibrosis across multiple organ systems by modulating the recruitment and activation of immune cells, which in turn influences the progression of fibrotic diseases in the liver, intestines, pancreas, heart, lungs, kidneys, and other organs. This paper introduces the biological functions of CCL2 and CCR2, highlighting their similarities and differences concerning fibrotic disorders in various organ systems, and reviews recent progress in the diagnosis and treatment of clinical fibrotic diseases linked to the CCL2/CCR2 signaling pathway. Additionally, further in-depth research is needed to explore the clinical significance of the CCL2/CCR2 axis in fibrotic conditions affecting different organs.

Atractylenolide-III restrains cardiac fibrosis after myocardial infarction via suppression of the RhoA/ROCK1 and ERK1/2 pathway

BACKGROUND

Cardiac fibrosis, a critical factor in myocardial remodeling post-myocardial infarction (MI), can advance heart failure progression. Atractylenolide III (ATL-III), derived from Atractylodes lancea, has recognized antioxidant and anti-inflammatory effects; however, its influence on cardiac fibrosis remains unclear.

METHODS

MI was induced in mice by permanent ligation of the left anterior descending (LAD) coronary artery, followed by 2 weeks of ATL-III or dimethyl sulfoxide (DMSO) treatment. Cardiac fibrosis was assessed by echocardiography, tissue histology, and serum biomarkers of myocardial injury. In vitro, the effects of ATL-III on cardiac fibroblast (CF) proliferation and collagen deposition were evaluated using immunofluorescence, 5-Ethynyl-2'-deoxyuridine (EdU), and western blot techniques. Network pharmacology and molecular docking identified potential ATL-III targets.

RESULTS

ATL-III treatment significantly improved cardiac function, as evidenced by increased ejection fraction (EF) and fractional shortening (FS) and reduced left ventricular dilation. Histological analysis revealed decreased fibrotic areas in ATL-III-treated mice, along with reduced expression of fibrosis markers α-SMA and Collagen I. ATL-III also alleviated oxidative stress by reducing reactive oxygen species (ROS) and malondialdehyde (MDA) levels while increasing superoxide dismutase (SOD) activity. Furthermore, ATL-III suppressed inflammation, decreasing TNF-α, IL-6, and IL-1β protein and mRNA levels. In vitro, ATL-III inhibited TGF-β1-induced CF proliferation, migration, and differentiation, reducing the expression of fibrotic markers. Mechanistically, ATL-III suppressed the RhoA/ROCK1 and ERK1/2 signaling pathways, as confirmed by molecular docking and pathway analysis.

CONCLUSION

ATL-III demonstrates therapeutic potential in mitigating post-MI cardiac fibrosis by reducing oxidative stress, inflammation, and CF activation. These findings highlight ATL-III as a promising candidate for the treatment of cardiac fibrosis and associated heart failure.

Inhibition of CCR2 attenuates NLRP3-dependent pyroptosis after myocardial ischaemia-reperfusion in rats via the NF-kB pathway

Myocardial infarction (MI) is a leading cause of mortality worldwide, contributing significantly to long-term cardiac dysfunction and heart failure. Effective therapeutic strategies are urgently needed to mitigate the extensive damage caused by MI and subsequent ischemia-reperfusion (I/R) injury. This study investigates the role of the Chemokine receptor 2 (CCR2) in regulating NLRP3-dependent cardiomyocyte pyroptosis following myocardial ischemia-reperfusion (MIR), elucidating its molecular mechanisms. A myocardial ischemia-reperfusion model was established using 124 Sprague-Dawley rats by ligating the left coronary artery, inducing 30 min of ischemia. Following ischemia, RS504393, a selective CCR2 antagonist, was administered intraperitoneally one hour after reperfusion. To further explore the underlying mechanisms, the NF-κB pathway agonist Phorbol 12-myristate 13-acetate (PMA) was administered 1 h post-MIR. The results showed a marked increase in CCR2 expression in the heart, peaking on the first day of reperfusion. Treatment with RS504393 significantly improved short-term cardiac function and reduced myocardial infarction size, decreased myocardial pyroptosis and suppressed the expression of NLRP3, GSDMD, Caspase-1, IL-1β, and IL-18 through inhibition of the NF-κB signaling pathway. This effect was reversed with the administration of PMA. In summary, the inhibition of CCR2 shows potential in mitigating myocardial injury following MIR by modulating the NF-κB signaling pathway. These findings highlight CCR2 as a promising therapeutic target for myocardial ischemia-reperfusion injury.

Emerging Role of Macrophage-Fibroblast Interactions in Cardiac Homeostasis and Remodeling

As major noncardiomyocyte components in cardiac tissues, macrophages and fibroblasts play crucial roles in maintaining cardiac homeostasis, orchestrating reparative responses after cardiac injuries, facilitating adaptive cardiac remodeling, and contributing to adverse cardiac remodeling, owing to their inherent heterogeneity and plasticity. Recent advances in research methods have yielded novel insights into the intricate interactions between macrophages and fibroblasts in the cardiac context. This review aims to comprehensively examine the molecular mechanisms governing macrophage-fibroblast interactions in cardiac homeostasis and remodeling, emphasize recent advancements in the field, and offer an evaluation from a translational standpoint.

HMGB1 promotes M1 polarization of macrophages and induces COPD inflammation

Chronic obstructive pulmonary disease (COPD) is a pervasive and incapacitating respiratory condition, distinguished by airway inflammation and the remodeling of the lower respiratory tract. Central to its pathogenesis is an intricate inflammatory process, wherein macrophages exert significant regulatory functions, and High mobility group box 1 (HMGB1) emerges as a pivotal inflammatory mediator potentially driving COPD progression. This study explores the hypothesis that HMGB1, within macrophages, modulates COPD through inflammatory mechanisms, focusing on its influence on macrophage polarization. Our investigation uncovered that HMGB1 is upregulated in the context of COPD, associated with an enhanced proinflammatory M1 macrophage polarization induced by cigarette smoke. This polarization is linked to suppressed cell proliferation and induced apoptosis, indicative of HMGB1's role in the disease's inflammatory trajectory. The study further implicates HMGB1 in the activation of the Nuclear factor kappa-B (NF-κB) signaling pathway and chemokine signaling within macrophages, which are likely to amplify the inflammatory response characteristic of COPD. The findings underscore HMGB1's critical involvement in COPD pathogenesis, presenting it as a significant target for therapeutic intervention aimed at modulating macrophage polarization and inflammation.

Potential mechanisms of rheumatoid arthritis therapy: Focus on macrophage polarization

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease that affects multiple organs and systems in the human body, often leading to disability. Its pathogenesis is complex, and the long-term use of traditional anti-rheumatic drugs frequently results in severe toxic side effects. Therefore, the search for a safer and more effective antirheumatic drug is extremely important for the treatment of RA. As important immune cells in the body, macrophages are polarized. Under pathological conditions, macrophages undergo proliferation and are recruited to diseased tissues upon stimulation. In the local microenvironment, they polarize into different types of macrophages in response to specific factors and perform unique functions and roles. Previous studies have shown that there is a link between macrophage polarization and RA, indicating that certain active ingredients can ameliorate RA symptoms through macrophage polarization. Notably, Traditional Chinese medicine (TCM) monomer component and compounds demonstrate a particular advantage in this process. Building upon this insight, we reviewed and analyzed recent studies to offer valuable and meaningful insights and directions for the development and application of anti-rheumatic drugs.

RANKL/RANK contributes to the pathological process of type 2 diabetes mellitus through TRAF3 activation of NIK

Diabetic osteoporosis is a complication of diabetes mellitus (DM). Denosumab (DMB) is an effective anti-osteoporotic drug functions by inhibiting NF-κB ligand receptor-activating factor (RANKL). Previous study found that osteoprotegerin (OPG) regulated βcell homeostasis through the RNAK/RANKL pathway. The present study aimed to investigate the effect of RANKL/RANK on the pathological process of DM and the underlying mechanism. We used D-glucose-induced RINm5F cells to construct in vitro type 2 diabetes models (T2DM). A high-fat diet combined with intraperitoneal injection of streptozotocin (STZ) was used to establish a T2DM model in SD rats. The apoptosis of β-cells was determined by TdT-mediated dUTP nick-end labeling (TUNEL) analysis. qRT-PCR and western blotting assays were used to explore the mRNA and protein expression of the TRAF3 (Tumor necrosis factor receptor-associated factor)/NIK (NF-κB-inducible kinase) pathway. Furthermore, insulin expression was detected by ELISA and immunohistochemistry assay. The islet morphology was analyzed by H&E. In vivo experiments demonstrated that sRANKL-IN-3 down-regulated insulin secretion levels by significantly ameliorating pancreatic tissue damage and mitigating apoptosis of high glucose induced β-cells. Subsequently, sRANKL-IN-3, acting as an inhibitor of RANKL, mitigated functional decline in β-cells induced by high glucose, mainly manifested by the low expression of PDX-1 (pancreatic duodenal homeobox 1), BETA2 (beta-2 adrenoceptors), INS-1 (insulin 1), and INS-2 (insulin 2). Mechanistic studies revealed that deletion of TRAF3 combined with sRANKL-IN-3 administration reduced the activity of NIK, NF-κB2, and RelB in RINm5F cells. In addition, our study demonstrated that inhibition of either RANKL or TRAF3 had a protective effect on high glucose induced apoptosis. Moreover, the combined action of sRANKL-IN-3 and shTRAF3 had a more pronounced inhibitory effect on high glucose-induced apoptosis. In summary, RANKL/RANK deficiency may attenuate apoptosis of β-cells, a phenomenon associated with the TRAF3/NIK pathway. Therefore, RANKL/RANK could be regarded as a potential therapeutic strategy for DM.

Fibroblast-Mediated Macrophage Recruitment Supports Acute Wound Healing

Epithelial and immune cells have long been appreciated for their contribution to the early immune response after injury; however, much less is known about the role of mesenchymal cells. Using single-nuclei RNA sequencing, we defined changes in gene expression associated with inflammation 1 day after wounding in mouse skin. Compared with those in keratinocytes and myeloid cells, we detected enriched expression of proinflammatory genes in fibroblasts associated with deeper layers of the skin. In particular, SCA1+ fibroblasts were enriched for numerous chemokines, including CCL2, CCL7, and IL-33, compared with SCA1- fibroblasts. Genetic deletion of Ccl2 in fibroblasts resulted in fewer wound-bed macrophages and monocytes during injury-induced inflammation, with reduced revascularization and re-epithelialization during the proliferation phase of healing. These findings highlight the important contribution of fibroblast-derived factors to injury-induced inflammation and the impact of immune cell dysregulation on subsequent tissue repair.

Trim72 is a major host factor protecting against lethal Candida albicans infection

Candida albicans is the most common aetiologic pathogen of fungal infections associated with high mortality in immunocompromised patients. There is an urgent need to develop new antifungal therapies owing to the poor efficacy and resistance of current antifungals. Here, we report that Trim72 positively regulates antifungal immunity during lethal fungal infection. Trim72 levels are significantly increased after Candida albicans infection. In vivo, Trim72 knockout significantly increases mortality, organ fungal burden and kidney damage in mice after lethal Candida albicans infection. Whereas recombinant Trim72 protein treatment protects mice against invasive candidiasis. Mechanistically, Trim72 facilitates macrophage infiltration and CCL2 production, which mediates Trim72-elicited protection against lethal Candida albicans infection. Furthermore, Trim72 may enhance macrophage migration and CCL2 production via NF-κB and ERK1/2 signaling. Inhibition of NF-κB and ERK1/2 signaling abrogates Trim72-mediated protection against lethal Candida albicans infection. Therefore, these data imply that Trim72 may be developed as a host-directed therapy for treating severe systemic candidiasis.

Research progress of two-pore potassium channel in myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) is a secondary injury caused by restoring blood flow after acute myocardial infarction, which may lead to serious arrhythmia and heart damage. In recent years, the role of potassium channels in MIRI has attracted much attention, especially the members of the two-pore domain potassium (K2P) channel family. K2P channel has unique structure and function, and the formation of its heterodimer increases its functional diversity. This paper reviews the structural characteristics, types, expression and physiological functions of K2P channel in the heart. In particular, we pay attention to whether members of the subfamily such as TWIK, TREK, TASK, TALK, THIK and TRESK participate in MIRI and their related mechanisms. Future research will help to reveal the molecular mechanism of K2P channel in MIRI and provide new strategies for the treatment of cardiovascular diseases.

Comprehensive analysis of macrophage-associated inflammatory genes in AMI based on bulk combined with single-cell sequencing data

Background

Previous studies have highlighted the crucial role of macrophages in the post-acute myocardial infarction (AMI) inflammatory response. This study specifically focused on investigating macrophage-related targets involved in the inflammatory response after AMI.

Methods

Bioinformatics methods were applied for identifying differentially expressed genes (DEGs) in datasets GSE163465, GSE236374, and GSE183272 obtained from the Gene Expression Omnibus (GEO) database. Communication analysis was conducted to analyze macrophages in AMI. Subsequent analyses encompassed functional enrichment analysis of Co-DEGs using Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG). Gene set variation analysis (GSVA) and immune infiltration analysis were carried out for screening key genes. Validation of the bioinformatics analysis results involved original and GSE114695 datasets, supported by quantitative real time polymerase chain reaction (qRT-PCR). Animal experiments confirmed the upregulation of Saa3, Acp5, and Fcgr4 genes in AMI mouse myocardial tissues.

Results

A total of 80 and 1,907 DEGs were respectively identified by analyzing scRNA-seq and bulk RNA-seq data. The overlapping Co-DEGs were found to be closely associated with inflammation-associated pathways, specifically the PI3K-Akt-mTOR pathway. Screening based on GSVA scores and macrophage-associated scores highlighted four key genes (Saa3, Ms4a4c, Acp5, and Fcgr4). Immunoinfiltration analysis revealed their close association with macrophages. Dataset validation corroborated these findings. Experimental validation focused on Saa3, Ms4a4c, Acp5, and Fcgr4, demonstrating the upregulation of their expression in cardiac macrophages in the AMI group, consistent with previous reports.

Conclusion

This study provides new perspectives on AMI treatment. In addition, Saa3, Acp5, and Fcgr4 exhibit potential as biomarkers for improving cardiac repair and slowing down the development of heart failure after AMI.

A study on the methylation patterns of DIO3 in patients with heart failure and its correlation with key clinical parameters

Objective

This study aimed to analyze the methylation pattern of deoxyribonucleic acid (CpG) sites in the DIO3_FA26 promoter region of patients with heart failure (HF) and explore the correlation between differential CpG methylation levels and various clinical parameters.

Methods

Peripheral blood specimens were collected from 20 patients with HF and 20 healthy individuals. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used to identify and detect the CpG sites in the DIO3_FA26 promoter region. CpG methylation levels were compared between patients with HF and healthy controls and patients with HF with different levels of cardiac function.

Results

The methylation level of DIO3_FA26_CpG_17.18 in patients with HF was significantly lower than that in the healthy control group (P = 0.0002). Among patients with HF and cardiac function levels of I/II and III/IV, methylation levels of DIO3_FA26_CpG_24.25.26.27 (P = 0.0168) were significantly lower in those with III/IV cardiac function compared to those with I/II cardiac function.

Conclusion

The methylation level of DIO3_FA26_CpG_17.18 is significantly reduced in patients with HF, and that of DIO3_FA26_CpG_24.25.26.27 is significantly decreased in patients with III/IV cardiac function. Variations in DIO3_FA26 methylation levels influence coagulation, liver and kidney functions, and routine blood indexes, including D-dimer, albumin, calcium, and hemoglobin. This study provides clinical evidence for the involvement of DIO3_FA26 methylation in the occurrence and development of HF and proposes novel targets for HF prevention and treatment.

High dietary antioxidant intake linked to lower risk of myocardial infarction: a nested case-control study

BACKGROUND

In developing nations, myocardial infarction (MI) remains a significant contributor to deaths from sudden cardiac arrest, with diet playing a key role in its incidence through oxidative stress mechanisms. Although the connection between the Dietary Antioxidant Index (DAI) and cardiovascular diseases has been demonstrated in some studies, the relationship between DAI and MI has not been extensively explored. Therefore, this research aims to investigate this association.

METHODS

We conducted a nested case-control study involving 156 MI cases and 312 healthy controls, utilizing data from the Fasa Adults Cohort Study (FACS), a population-based study of individuals aged 35-70 residing in Fasa, Iran, with 11,097 participants included at baseline. The DAI was determined by normalizing the intake values of six dietary vitamins and minerals, adjusting by subtracting the global mean, and then dividing by the global standard deviation. MI diagnosis was established by an experienced cardiologist using electronic medical records. Conditional logistic regression was employed to examine the association between DAI and MI.

RESULTS

There were no significant differences between the case and control groups in terms of age (P = 0.96), gender distribution (P = 0.98), and education level (P = 0.38). In a multiple conditional logistic regression analysis, after adjusting for key variables-including body mass index (BMI), smoking status, education level, and serum levels of triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol (TC), fasting blood sugar (FBS), saturated fatty acids (SFA), and polyunsaturated fatty acids (PUFA)-an inverse association was found between DAI and the risk of myocardial infarction (MI) [adjusted Odds Ratio (Adj OR) = 0.88, 95% Confidence Interval (CI): 0.85-0.92; P < 0.001].

CONCLUSIONS

This study highlights the crucial role of the DAI in reducing the risk of myocardial infarction. Promoting diets rich in antioxidants presents a straightforward and effective strategy for MI prevention and the promotion of cardiovascular health, underscoring the novelty and significance of this research in dietary approaches to disease prevention.

Identification of diagnostic signature and immune infiltration for ischemic cardiomyopathy based on cuproptosis-related genes through bioinformatics analysis and experimental validation

BACKGROUND

Ischemic cardiomyopathy (IC) is primarily due to long-term ischemia/hypoxia of the coronary arteries, leading to impaired cardiac contractile or diastolic function. A new form of cell death induced by copper, called "cuproptosis" is related to the development and progression of multiple diseases. The cuproptosis-related gene (CuGs) plays an important role in acute myocardial infarction, while the specific mechanisms of CuGs in ischemic cardiomyopathy remain unclear.

METHODS

The expressions of CuGs and their immune characteristics were analyzed with the IC datasets obtained from the Gene Expression Omnibus, namely GSE5406 and GSE57338, identifying core genes associated with IC development. By comparing RF, SVM, GLM and XGB models, the optimal machine learning model was selected. The expression of marker genes was validated based on the GSE57345, GSE48166 and GSE42955 datasets. Construct a CeRNA network based on core genes. Therapeutic chemiacals targeting core genes were acquired using the CTD database, and molecular docking was performed using Autodock vina software. By ligating the left anterior descending (LAD) coronary artery, an IC mouse model is established, and core genes were experimentally validated using Western blot (WB) and immunohistochemistry (IHC) methods.

RESULTS

We identified 14 CuGs closely associated with the onset of IC. The SVM model exhibited superior discriminative power (AUC = 0.914), with core genes being DLST, ATP7B, FDX1, SLC31A1 and DLAT. Core genes were validated on the GSE42955, GSE48166 and GSE57345 datasets, showing excellent performance (AUC = 0.943, AUC = 0.800, and AUC = 0.932). The CeRNA network consists of 218 nodes and 264 lines, including 5 core diagnostic genes, 52 miRNAs, and 161 lncRNAs. Chemicals predictions indicated 8 chemicals have therapeutic effects on the core diagnostic genes, with benzo(a)pyrene molecular docking showing the highest affinity (-11.3 kcal/mol). Compared to the normal group, the IC group,which was established by LAD ligation, showed a significant decrease in LVEF as indicated by cardiac ultrasound, and increased fibrosis as shown by MASSON staining, WB results suggest increased expression of DLST and ATP7B, and decreased expression of FDX1, SLC31A1 and DLAT in the myocardial ischemic area (p < 0.05), which was also confirmed by IHC in tissue sections.

CONCLUSION

In summary, this study comprehensively revealed that DLST, ATP7B, FDX1, SLC31A1 and DLAT could be identified as potential immunological biomarkers in IC, and validated through an IC mouse model, providing valuable insights for future research into the mechanisms of CuGs and its diagnostic value to IC.

Single-cell transcriptomics reveals writers of RNA modification-mediated immune microenvironment and cardiac resident Macro-MYL2 macrophages in heart failure

BACKGROUND

Heart failure (HF), which is caused by cardiac overload and injury, is linked to significant mortality. Writers of RNA modification (WRMs) play a crucial role in the regulation of epigenetic processes involved in immune response and cardiovascular disease. However, the potential roles of these writers in the immunological milieu of HF remain unknown.

METHODS

We comprehensively characterized the expressions of 28 WRMs using datasets GSE145154 and GSE141910 to map the cardiac immunological microenvironment in HF patients. Based on the expression of WRMs, the immunological cells in the datasets were scored.

RESULTS

Single-cell transcriptomics analysis (GSE145154) revealed immunological dysregulation in HF as well as differential expression of WRMs in immunological cells from HF and non-HF (NHF) samples. WRM-scored immunological cells were positively correlated with the immunological response, and the high WRM score group exhibited elevated immunological cell infiltration. WRMs are involved in the differentiation of T cells and myeloid cells. WRM scores of T cell and myeloid cell subtypes were significantly reduced in the HF group compared to the NHF group. We identified a myogenesis-related resident macrophage population in the heart, Macro-MYL2, that was characterized by an increased expression of cardiomyocyte structural genes (MYL2, TNNI3, TNNC1, TCAP, and TNNT2) and was regulated by TRMT10C. Based on the WRM expression pattern, the transcriptomics data (GSE141910) identified two distinct clusters of HF samples, each with distinct functional enrichments and immunological characteristics.

CONCLUSION

Our study demonstrated a significant relationship between the WRMs and immunological microenvironment in HF, as well as a novel resident macrophage population, Macro-MYL2, characterized by myogenesis. These results provide a novel perspective on the underlying mechanisms and therapeutic targets for HF. Further experiments are required to validate the regulation of WRMs and Macro-MYL2 macrophage subtype in the cardiac immunological milieu.

The predictive value of the triglyceride glucose index combined with cystatin C for the prognosis of patients with acute coronary syndrome

Background

Recent studies have shown that the triglyceride glucose index (TyG) and cystatin C (CysC) are closely related to cardiovascular disease, but there is limited research on the prognosis of patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI). The aim of this study was to explore the predictive value of the combination of the TyG index and CysC in predicting major adverse cardiovascular events (MACEs) in ACS patients who underwent PCI.

Methods

This retrospective study included 319 ACS patients who underwent PCI. The clinical endpoint was the occurrence of MACEs, including all-cause mortality, heart failure, non-fatal myocardial infarction, target vessel revascularization, and angina requiring hospitalization. Patients were classified into MACEs (65 cases) and non-MACEs (254 cases) groups. Univariate factor and multivariate analysis were used to identify predictors of MACEs. The receiver operating curve (ROC) of the prediction model of MACEs was determined. Additionally, the net reclassification improvement and integrated discrimination improvement indexes were calculated to further assess the additional predictive value of the risk factors for MACEs. Subgroup and interaction analysis between the TyG index combined with CysC and MACEs were conducted in various subgroups. Patients were stratified according to the optimal cutoff point value of the TyG index and the CysC determined by ROC curve analysis. The Kaplan-Meier analysis method was used to construct a survival curve 1 year after PCI.

Results

During a median follow-up period of 14 months, 65 (20.38%) patients had experienced at least one primary endpoint event. Multivariate logistic regression analysis indicated that the TyG index and CysC were independently associated with an increased risk of MACEs after PCI (OR, 2.513, 95% CI 1.451-4.351, P= 0.001; and OR, 4.741, 95% CI 1.344-16.731, P=0.016, respectively). The addition of the TyG index and CysC to the baseline risk model had the strongest incremental effect for predicting MACEs in terms of the C-statistic from 0.789 (95% CI 0.723-0.855, P<0.001) to 0.799 (95% CI 0.733-0.865, P<0.001). Furthermore, Kaplan-Meier analysis demonstrated that a TyG index greater than 9.325 and a CysC value greater than 1.065 mg/ml were significantly associated with an increased risk of MACEs (log-rank, all P < 0.01).

Conclusion

The TyG index predicts MACEs after PCI in patients with ASC independent of known cardiovascular risk factors. Adjustment of the CysC by the TyG index further improves the predictive ability for MACEs in patients with ACS undergoing PCI. Thus, both of them are expected to become new prognostic indicators for MACEs in patients with ACS after PCI.

Deep skin fibroblast-mediated macrophage recruitment supports acute wound healing

Epithelial and immune cells have long been appreciated for their contribution to the early immune response after injury; however, much less is known about the role of mesenchymal cells. Using single nuclei RNA-sequencing, we defined changes in gene expression associated with inflammation at 1-day post-wounding (dpw) in mouse skin. Compared to keratinocytes and myeloid cells, we detected enriched expression of pro-inflammatory genes in fibroblasts associated with deeper layers of the skin. In particular, SCA1+ fibroblasts were enriched for numerous chemokines, including CCL2, CCL7, and IL33 compared to SCA1- fibroblasts. Genetic deletion of Ccl2 in fibroblasts resulted in fewer wound bed macrophages and monocytes during injury-induced inflammation with reduced revascularization and re-epithelialization during the proliferation phase of healing. These findings highlight the important contribution of deep skin fibroblast-derived factors to injury-induced inflammation and the impact of immune cell dysregulation on subsequent tissue repair.

The phytochemistry and pharmacology of three Rheum species: A comprehensive review with future perspectives

BACKGROUND

Rheum palmatum, R. tanguticum, and R. officinale, integral species of the genus Rheum, are widely used across global temperate and subtropical regions. These species are incorporated in functional foods, medicines, and cosmetics, recognized for their substantial bioactive components.

PURPOSE

This review aims to synthesize developments from 2014 to 2023 concerning the botanical characteristics, ethnopharmacology, nutritional values, chemical compositions, pharmacological activities, mechanisms of action, and toxicity of these species.

METHODS

Data on the three Rheum species were gathered from a comprehensive review of peer-reviewed articles, patents, and clinical trials accessed through PubMed, Google Scholar, Web of Science, and CNKI.

RESULTS

The aerial parts are nutritionally rich, providing essential amino acids, fatty acids, and minerals, suitable for use as health foods or supplements. Studies have identified 143 chemical compounds, including anthraquinones, anthrones, flavonoids, and chromones, which contribute to their broad pharmacological properties such as laxative, anti-diarrheal, neuroprotective, hepatoprotective, cardiovascular, antidiabetic, antitumor, anti-inflammatory, antiviral, and antibacterial effects. Notably, the materials science approach has enhanced understanding of their medicinal capabilities through the evaluation of bioactive compounds in different therapeutic contexts.

CONCLUSION

As medicinal and economically significant herb species, Rheum species provide both edible aerial parts and medicinal underground components that offer substantial health benefits. These characteristics present new opportunities for developing nutritional ingredients and therapeutic products, bolstering the food and pharmaceutical industries.

Anti-inflammatory effects and related mechanisms of naringenin in human periodontal ligament stem cells under lipopolysaccharide stimulation based on RNA sequencing

OBJECTIVES

RNA sequencing (RNA-seq) and bioinformatic analysis were combined and used to explore the anti-inflammatory effects and mechanisms of naringenin (Nar) in lipopolysaccharide (LPS)-stimulated human periodontal ligament stem cells (hPDLSCs).

METHODS

Cell counting kit-8, quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), and enzyme-linked immunosorbent assay (ELISA) were adopted to detect the effects of Nar on the proliferation and expression of inflammatory factors in LPS-stimulated hPDLSCs, screening for the optimal anti-inflammatory concentration of Nar. Differentially expressed genes (DEGs) were screened using |log2FC|≥1 and P≤0.05 as criteria. Volcano plot analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, the String database, and the MCODE module of Cytoscape were utilized to select core genes and enriched pathways. The effects on the nuclear factor κB (NF-κB) signaling pathway were verified using ELISA, qRT-PCR, and Western blot.

RESULTS

Appropriate concentrations of Nar could alleviate the expression of inflammatory factors and promote the proliferation of hPDLSCs stimulated by LPS. The best anti-inflammatory effect was achieved with 20 μmol/L Nar. RNA-seq showed significant enrichment of inflammation-related signaling pathways. The anti-inflammatory effect of Nar was mediated by inhibiting the NF-κB signaling pathway, similar to the effect of the NF-κB inhibitor BAY 11-7802.

CONCLUSIONS

Nar could exert its anti-inflammatory effects by inhibiting the NF-κB signaling pathway, making it a potential therapeutic option for the adjuvant treatment of periodontitis.

m6A epitranscriptomic modification of inflammation in cardiovascular disease

Cardiovascular disease is currently the number one cause of death endangering human health. There is currently a large body of research showing that the development of cardiovascular disease and its complications is often accompanied by inflammatory processes. In recent years, epitranscriptional modifications have been shown to be involved in regulating the pathophysiological development of inflammation in cardiovascular diseases, with 6-methyladenine being one of the most common RNA transcriptional modifications. In this review, we link different cardiovascular diseases, including atherosclerosis, heart failure, myocardial infarction, and myocardial ischemia-reperfusion, with inflammation and describe the regulatory processes involved in RNA methylation. Advances in RNA methylation research have revealed the close relationship between the regulation of transcriptome modifications and inflammation in cardiovascular diseases and brought potential therapeutic targets for disease diagnosis and treatment. At the same time, we also discussed different cell aspects. In addition, in the article we also describe the different application aspects and clinical pathways of RNA methylation therapy. In summary, this article reviews the mechanism, regulation and disease treatment effects of m6A modification on inflammation and inflammatory cells in cardiovascular diseases in recent years. We will discuss issues facing the field and new opportunities that may be the focus of future research.

Cardiomyocyte-specific overexpression of GPR22 ameliorates cardiac injury in mice with acute myocardial infarction

BACKGROUND

The activation of G protein-coupled receptors (GPCR) signaling by external stimuli has been implicated in inducing cardiac stress and stress responses. GPR22 is an orphan GPCR expressed in brains and hearts, while its expression level is associated with cardiovascular damage in diabetes. Previous studies have suggested a protective role of GPR22 in mechanical cardiac stress, as loss of its expression increases susceptibility to heart failure post-ventricular pressure overload. However, the involvement and underlying signaling of GPR22 in cardiac stress response to ischemic stress remains unexplored.

METHODS

In this study, we used cultured cells and a transgenic mouse model with cardiomyocyte-specific GPR22 overexpression to investigate the impact of ischemic stress on GPR22 expression and to elucidate its role in myocardial ischemic injury. Acute myocardial infarction (AMI) was induced by left coronary artery ligation in eight-week-old male GPR22 transgenic mice, followed by histopathological and biochemical examination four weeks post-AMI induction.

RESULTS

GPR22 expression in H9C2 and RL-14 cells, two cardiomyocyte cell lines, was decreased by cobalt chloride (CoCl2) treatment. Similarly, reduced expression of myocardial GPR22 was observed in mice with AMI. Histopathological examinations revealed a protective effect of GPR22 overexpression in attenuating myocardial infarction in mice with AMI. Furthermore, myocardial levels of Bcl-2 and activation of PI3K-Akt signaling were downregulated by ischemic stress and upregulated by GPR22 overexpression. Conversely, the expression levels of caspase-3 and phosphorylated ERK1/2 in the infarcted myocardium were downregulated with GPR22 overexpression.

CONCLUSION

Myocardial ischemic stress downregulates cardiac expression of GPR22, whereas overexpression of GPR22 in cardiomyocytes upregulates Akt signaling, downregulates ERK activation, and mitigates ischemia-induced myocardial injury.

Costunolide mitigates inflammation and promotes extracellualr matrix integrity of thoracic aortic dissection by inhibiting NF-κB signaling

BACKGROUND

Thoracic aortic dissection (TAD) is one of the most fatal cardiovascular diseases. One of its important pathological characteristics is the local inflammatory response. Many studies have found that Macrophage polarization plays an extremely critical role in the inflammatory progression and tissue remodeling of TAD. Costunolide (CTD) has an improving effect on oxidative stress and inflammation in the body. However, whether it can promote the integrity of extracellular matrix in Aortic dissection and its mechanism are still unclear.

METHODS

The male C57BL/6J mice were used to construct an animal model of TAD with β-aminopropionitrile (BAPN) (100 mg/kg/day, lasting for 28 days), and then CTD (10 mg/kg or 100 mg/kg) was injected intraperitoneally for 28 days to check the survival rate, TAD incidence, aortic morphology and other indicators of the mice. Using hematoxylin-eosin (HE), Masson, Elastin van Gieson (EVG) staining, immunofluorescence (IF), and immunohistochemical staining, the study aimed to determine the therapeutic effects of CTD on an animal model with BAPN-induced TAD. To enhance the examination of the regulatory mechanism of CTD, we conducted transcriptome sequencing on arterial tissues of mice in both the BAPN group and the BAPN + CTD100 group. Next, ANG II were used to construct TAD model in vascular smooth muscle cells (VMSCs). The effects of CTD on the proliferation, migration, invasion, and apoptosis of ANG II-induced cells are to be detected. The expression of MMP2, MMP9, P65, and p-P65 in each group will be examined using Western blot. Finally, the overexpression of IκB kinaseβ (IKKβ) will be established in VMSCs cells to further explore the protective function of CTD.

RESULTS

The result showed that CTD significantly inhibited BAPN induced mortality and TAD incidence in the animal model, improved aortic vascular morphology, promoted the integrity of extracellular matrix in TAD, reduced tissue inflammation, reduced the accumulation of M1 macrophage, promoted M2 macrophage polarization, and reduced the expression of NF-κB pathway related proteins. Mechanistically, CTD significantly weakened the proliferation, migration, invasion, and apoptosis. p-P65 protein expression of TAD cells were induced by ANG II and IKK-β.

CONCLUSION

CTD has the potential to alleviate inflammation, VSMC apoptosis, MMP2/9 levels, and enhance extracellular matrix integrity in TAD by inhibiting the NF-κB signaling pathway.

Protective effects of METRNL overexpression against pathological cardiac remodeling

At present, meteorin-like protein (METRNL) has been proven to be widely expressed in the myocardium and participates in the pathogenic process of various cardiovascular diseases. However, the effects of METRNL on pathological cardiac hypertrophy is still unknown. In the present study, we used a mouse model of transverse aortic constriction (TAC) surgery to mimic pathological cardiac hypertrophy and gene delivery system to overexpress METRNL in vivo. The results showed that METRNL overexpression improved TAC-induced pathological cardiac hypertrophy in mice and neonatal cardiomyocytes. In addition, METRNL overexpression diminished TAC-induced cardiac oxidative damage, inflammation and cardiomyocyte apoptosis. Moreover, the cardioprotective effect of METRNL overexpression was directly related to the activation of AMP-activated protein kinase (AMPK) and sirtuin1 (SIRT1). In summary, our data identified that METRNL may be a promising therapeutic target to mitigate pathological cardiac hypertrophy in the future.

Interleukin-22 inhibits cardiac fibrosis by regulating fibroblast metabolic reprogramming in myocardial infarction

Cardiac fibrosis, a significant characteristic of cardiovascular diseases, leads to ventricular remodeling and impaired cardiac function. In this study, we aimed to investigate the role of Interleukin-22 (IL-22) in myocardial fibrosis following myocardial infarction (MI) and to explore the underlying metabolic mechanisms. Here we analyzed the single-cell sequencing data and found that the level of aerobic glycolysis was significantly higher in cardiac fibrosis in MI patient, which we validated through in vivo experiments. Utilizing MI mouse model, these experiments revealed decreased serum IL-22 levels and increased levels of AngII and TGF-β1. However, treatment with exogenous IL-22 reversed these changes, reduced infarct size, and fibrosis. In vitro experiments demonstrated that IL-22 inhibited AngII-induced fibroblast-to-myofibroblast transition (FMT) by suppressing the expression of α-SMA, Cola1, and Cola3. Metabolic analysis indicated that IL-22 decreased the expression of glycolytic enzymes and reduced lactate production in cardiac fibroblasts. Further in vivo experiments confirmed the inhibitory effect of IL-22 on Pyruvate kinase isoform M2 (PKM2) levels in heart tissue. Additionally, IL-22 activated the c-Jun N-terminal kinase (JNK) pathway, while inhibition of JNK partially reversed IL-22's effect on PKM2 activity. These findings suggest that IL-22 mitigates cardiac fibrosis and FMT by inhibiting aerobic glycolysis by activating the JNK/PKM2 pathway. Our study highlights IL-22 as a potential therapeutic target for myocardial fibrosis and cardiovascular diseases, providing insights into its role in regulating fibrosis and glycolysis. These findings pave the way for developing targeted therapies and investigating additional metabolic pathways for improved treatment outcomes in the field of cardiovascular diseases.

The phenotype and related gene expressions of macrophages in adipose tissue of T2D mice following MSCs infusion

BACKGROUND

Infusion of mesenchymal stem cells (MSCs) induces polarization of M2 macrophages in adipose tissue of type 2 diabetes (T2D) mice. Studies have shown that M2 macrophages were divided into four sub-phenotypes (M2a, M2b, M2c and M2d) with different functions, and manuscripts have also confirmed that macrophages co-cultured with MSCs were not matched with known four phenotype macrophages. Therefore, our study explored the phenotype and related gene expressions of macrophages in the adipose tissue of T2D mice with/without MSCs infusion.

METHODS

We induced a T2D mouse model by using high-fat diets and streptozotocin (STZ) injection. The mice were divided into three groups: the control group, the T2D group, and the MSCs group. MSCs were systemically injected once a week for 6 weeks. The phenotype of macrophages in adipose tissue was detected via flow cytometric analysis. We also investigated the gene expression of macrophages in different groups via SMART-RNA-sequencing and quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR).

RESULTS

The present study found that the macrophages of adipose tissue in the MSCs group were polarized to the M2 phenotype mixed with four sub-phenotypes. Besides, M2a and M2c held a dominant position, while M2b and M2d (tumor-associated macrophages, TAMs) exhibited a decreasing trend after infusion of MSCs. Moreover, the MSCs group did not appear to express higher levels of tumor-associated, inflammation-associated, or fibrosis-associated genes in comparison to the T2D group.

CONCLUSION

The present results unveiled that the macrophage phenotype was inclined to be present in a hybridity state of four M2 sub-phenotypes and the genes related to tumor-promoting, pro-inflammation and pro-fibrosis were not increased after MSCs injection.

Mac-1 deficiency ameliorates pressure overloaded heart failure through inhibiting macrophage polarization and activation

Persistent pressure overload commonly leads to pathological cardiac hypertrophy and remodeling, ultimately leading to heart failure (HF). Cardiac remodeling is associated with the involvement of immune cells and the inflammatory response in pathogenesis. The macrophage-1 antigen (Mac-1) is specifically expressed on leukocytes and regulates their migration and polarization. Nonetheless, the involvement of Mac-1 in cardiac remodeling and HF caused by pressure overload has not been determined. The Mac-1-knockout (KO) and wild-type (WT) mice were subjected to transverse aortic constriction (TAC) for 6 weeks. Echocardiography and pressure-volume loop assessments were used to evaluate cardiac function, and cardiac remodeling and macrophage infiltration and polarization were estimated by histopathology and molecular techniques. The findings of our study demonstrated that Mac-1 expression was markedly increased in hearts subjected to TAC treatment. Moreover, compared with WT mice, Mac-1-KO mice exhibited dramatically ameliorated TAC-induced cardiac dysfunction, hypertrophy, fibrosis, oxidative stress and apoptosis. The potential positive impacts may be linked to the inhibition of macrophage infiltration and M1 polarization via reductions in NF-kB and STAT1 expression and upregulation of STAT6. In conclusion, this research reveals a new function of Mac-1 deficiency in reducing pathological cardiac remodeling and HF caused by pressure overload. Additionally, inhibiting Mac-1 could be a potential treatment option for patients with HF in a clinical setting.

GDF15 restrains myocardial ischemia-reperfusion injury through inhibiting GPX4 mediated ferroptosis

BACKGROUND

Growth and differentiation factor 15 (GDF15) has been proved to regulate the process of Myocardial ischemia-reperfusion injury (MIRI), which is a serious complication of reperfusion therapy. The present study aimed to explore if GDF15 could regulate the MIRI-induced ferroptosis.

METHOD

MIRI animal model was established by ligating the left anterior descending coronary artery. Oxygen-glucose deprivation/reoxygenation (OGD/R) cell model was established to imitate MIRI in vitro. The indicators of ferroptosis including mitochondrial damage, GPX4, FACL4, XCT4, and oxidative stress markers were evaluated.

RESULTS

Overexpression of GDF15 greatly inhibited MIRI, improved cardiac function, alleviated MIRI-induced ferroptosis. pc-DNA-GDF15 significantly inhibited the oxidative stress condition and inflammation response. The OGD/R-induced ferroptosis was also inhibited by pc-DNA-GDF15.

CONCLUSION

We proved that the MIRI-induced ferroptosis could by inhibited by pc-DNA-GDF15 through evaluating mitochondrial damage, MDA, GSH, and GSSG. Our research provides a new insight for the prevention and treatment of MIRI, and a new understanding for the mechanism of MIRI-induced ferroptosis.

Investigation of the active ingredients of Shuangshen Ningxin Fomula and the mechanism underlying their protective effects against myocardial ischemia-reperfusion injury by mass spectrometric imaging

BACKGROUND

Traditional Chinese medicine, particularly Shuangshen Ningxin Capsule (SSNX), has been studied intensely. SSNX includes total ginseng saponins (from Panax ginseng Meyer), total phenolic acids from Salvia miltiorrhiza Bunge, and total alkaloids from Corydalis yanhusuo W. T. Wang. It has been suggested to protect against myocardial ischemia by a mechanism that has not been fully elucidated.

METHODS

The composition and content of SSNX were determined by UHPLC-Q-TOFQ-TOF / MS. Then, a rat model of myocardial ischemia-reperfusion injury was established, and the protective effect of SSNX was measured. The protective mechanism was investigated using spatial metabolomics.

RESULTS

We found that SSNX significantly improved left ventricular function and ameliorated pathological damages in rats with myocardial ischemia-reperfusion injury. Using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), the protective mechanism of SSNX was examined by comparing the monomer components of drugs targeted in myocardial tissue with the distribution of myocardial energy metabolism-related molecules and phospholipids. Interestingly, some lipids display inconsistent content distribution in the myocardial ischemia risk and non-risk zones. These discrepancies reflect the degree of myocardial injury in different regions.

CONCLUSION

These findings suggest that SSNX protects against myocardial ischemia-reperfusion injury by correcting abnormal myocardial energy metabolism, changing the levels and distribution patterns of phospholipids, and stabilizing the structure of the myocardial cell membrane. MALDI-TOF MS can detect the spatial distribution of small molecule metabolites in the myocardium and can be used in pharmacological research.

Omaveloxolone ameliorates isoproterenol-induced pathological cardiac hypertrophy in mice

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important transcriptional regulator that plays a protective role against various cardiovascular diseases. Omaveloxolone is a newly discovered potent activator of Nrf2 that has a variety of cytoprotective functions. However, the potential role of omaveloxolone in the process of pathological cardiac hypertrophy and heart failure are still unknown. In this study, an isoproterenol (ISO)-induced pathological cardiac hypertrophy model was established to investigate the protective effect of omaveloxolone in vivo and in vitro. Our study first confirmed that omaveloxolone administration improved ISO-induced pathological cardiac hypertrophy in mice and neonatal cardiomyocytes. Omaveloxolone administration also diminished ISO-induced cardiac oxidative stress, inflammation and cardiomyocyte apoptosis. In addition, omaveloxolone administration activated the Nrf2 signaling pathway, and Nrf2 knockdown almost completely abolished the cardioprotective effect of omaveloxolone, indicated that the cardioprotective effect of omaveloxolone was directly related to the activation of the Nrf2 signaling. In summary, our study identified that omaveloxolone may be a promising therapeutic agent to mitigate pathological cardiac hypertrophy.