Trimethylamine N-oxide promotes apoE-/- mice atherosclerosis by inducing vascular endothelial cell pyroptosis via the SDHB/ROS pathway

Trimethylamine N-Oxide in Aquatic Foods

Trimethylamine N-oxide (TMAO), a characteristic nonprotein nitrogen compound, is widely present in seafood, which exhibits osmoregulatory effects for marine organisms in vivo and plays an important role in aquaculture and aquatic product preservation. However, much attention has been focused on the negative effect of TMAO since it has recently emerged as a putative promoter of chronic diseases. To get full knowledge and maximize our ability to balance the positive and negative aspects of TMAO, in this review, we comprehensively discuss the TMAO in aquatic products from the aspects of physiological functions for marine organisms, flavor, quality, the conversion of precursors, the influences on human health, and the seafood ingredients interaction consideration. Though the circulating TMAO level is inevitably enhanced after seafood consumption, dietary seafood still exhibits beneficial health effects and may provide nutraceuticals to balance the possible adverse effects of TMAO.

Gut microbial metabolites in MASLD: Implications of mitochondrial dysfunction in the pathogenesis and treatment

With an increasing prevalence, metabolic dysfunction-associated steatotic liver disease (MASLD) has become a major global health problem. MASLD is well-known as a multifactorial disease. Mitochondrial dysfunction and alterations in the gut bacteria are 2 vital events in MASLD. Recent studies have highlighted the cross-talk between microbiota and mitochondria, and mitochondria are recognized as pivotal targets of the gut microbiota to modulate the host's physiological state. Mitochondrial dysfunction plays a vital role in MASLD and is associated with multiple pathological changes, including hepatocyte steatosis, oxidative stress, inflammation, and fibrosis. Metabolites are crucial mediators of the gut microbiota that influence extraintestinal organs. Additionally, regulation of the composition of gut bacteria may serve as a promising therapeutic strategy for MASLD. This study reviewed the potential roles of several common metabolites in MASLD, emphasizing their impact on mitochondrial function. Finally, we discuss the current treatments for MASLD, including probiotics, prebiotics, antibiotics, and fecal microbiota transplantation. These methods concentrate on restoring the gut microbiota to promote host health.

Hyperactivation of succinate dehydrogenase promotes pyroptosis of macrophage via ROS-induced GSDMD oligomerization in acute liver failure

Acute liver failure (ALF) is a life-threatening disease with high mortality. Given excessive inflammation is one of the major pathogenesis of ALF, candidates targeting inflammation could be beneficial in the condition. Now the effect of hyperactivated succinate dehydrogenase (SDH) on promoting inflammation in lipopolysaccharide (LPS)-treated macrophages has been studied. However, its role and mechanism in ALF is not well understood. Here intraperitoneal injection of D-galactosamine and LPS was conducted in male C57BL/6 J mice to induce the ALF model. Dimethyl malonate (DMM), which inhibited SDH activity, was injected intraperitoneally 30 min before ALF induction. Macrophage pyroptosis was induced by LPS plus adenosine triphosphate (ATP). Pyroptosis-related molecules and proteins including GSDMD oligomer were examined by ELISA and western blot techniques, respectively. ROS production was assessed by fluorescence staining. The study demonstrated SDH activity was increased in liver macrophages from ALF mice. Importantly, DMM administration inhibited ROS, IL-1β, and pyroptosis-associated proteins levels (NLRP3, cleaved caspase-1, GSDMD-N, and GSDMD oligomers) both in the ALF model and in macrophages stimulated with LPS plus ATP. In vitro, ROS promoted pyroptosis by facilitating GSDMD oligomerization. Additionally, when ROS levels were increased through the addition of H2O2 to the DMM group, the levels of GSDMD oligomers were reverted. In conclusion, SDH hyperactivation promotes macrophage pyroptosis by ROS-mediated GSDMD oligomerization, suggesting that targeting this pathway holds promise as a strategy for treating ALF and other inflammatory diseases.

1,7-diphenyl-4-hepten-3-one mitigates Alzheimer's-like pathology by inhibiting pyroptosis via activating the Nrf2 pathway

Pyroptosis-mediated neuron death plays a crucial role in neurodegenerative diseases, such as Alzheimer's disease (AD). However, the effect of 1,7-diphenyl-4-hepten-3-one (C1), a natural diarylheptanoid, on AD is unclear. Herein, we investigated the therapeutic effect of C1 on APP/PS1 mice and β-amyloid (Aβ)-induced HT22 cells. Our findings showed that C1 attenuated cognitive impairment and mitigated pathological damage in APP/PS1 mice. Furthermore, we found that C1 prevented oxidative stress damage and decreased the levels of pyroptosis-related proteins. In vitro experiments showed that C1 can improve the proliferation of Aβ-induced HT22 cells and decrease the levels of pyroptosis-related proteins in them. When Nrf2 was silenced, the positive effects of C1 in inhibiting pyroptosis were inhibited. Particularly, the production of pyroptosis-associated proteins, including NLRP3, GSDMD, and caspase-1, and the secretion of pro-inflammatory molecules, including IL-1 and IL-18, were increased. Altogether, these findings indicate that C1 can mitigate AD-like pathology via the inhibition of pyroptosis by activating the Nrf2 pathway. We believe that this study can provide alternative strategies for the prevention and treatment of AD.

A novel pyroptosis-related gene signature exhibits distinct immune cells infiltration landscape in Wilms' tumor

BACKGROUND

Wilms' tumor (WT) is the most common renal tumor in childhood. Pyroptosis, a type of inflammation-characterized and immune-related programmed cell death, has been extensively studied in multiple tumors. In the current study, we aim to construct a pyroptosis-related gene signature for predicting the prognosis of Wilms' tumor.

METHODS

We acquired RNA-seq data from TARGET kidney tumor projects for constructing a gene signature, and snRNA-seq data from GEO database for validating signature-constructing genes. Pyroptosis-related genes (PRGs) were collected from three online databases. We constructed the gene signature by Lasso Cox regression and then established a nomogram. Underlying mechanisms by which gene signature is related to overall survival states of patients were explored by immune cell infiltration analysis, differential expression analysis, and functional enrichment analysis.

RESULTS

A pyroptosis-related gene signature was constructed with 14 PRGs, which has a moderate to high predicting capacity with 1-, 3-, and 5-year area under the curve (AUC) values of 0.78, 0.80, and 0.83, respectively. A prognosis-predicting nomogram was established by gender, stage, and risk score. Tumor-infiltrating immune cells were quantified by seven algorithms, and the expression of CD8( +) T cells, B cells, Th2 cells, dendritic cells, and type 2 macrophages are positively or negatively correlated with risk score. Two single nuclear RNA-seq samples of different histology were harnessed for validation. The distribution of signature genes was identified in various cell types.

CONCLUSIONS

We have established a pyroptosis-related 14-gene signature in WT. Moreover, the inherent roles of immune cells (CD8( +) T cells, B cells, Th2 cells, dendritic cells, and type 2 macrophages), functions of differentially expressed genes (tissue/organ development and intercellular communication), and status of signaling pathways (proteoglycans in cancer, signaling pathways regulating pluripotent of stem cells, and Wnt signaling pathway) have been elucidated, which might be employed as therapeutic targets in the future.

TMAO promotes vascular endothelial cell pyroptosis via the LPEAT-mitophagy pathway

Trimethylamine N-oxide (TMAO) is a novel risk factor for atherosclerosis, and its underlying regulatory mechanisms are under intensive investigation. Inflammation-related vascular endothelial damage is the major driver in atherogenic process. Pyroptosis, a type of proinflammatory programmed cell death, has been proved to promote the initiation and progression of atherosclerosis. In our study, we found that TMAO triggered endothelial cells excessive mitophagy, thereby facilitating pyroptosis. This process is mediated by the upexpression of phosphatidylethanolamine acyltransferase (LPEAT). These findings provide insights into TMAO-induced vascular endothelial cell damage and suggest that LPEAT may be a valuable target for the prevention and treatment of atherosclerosis.

Trimethylamine N-oxide promotes oxidative stress and lipid accumulation in macrophage foam cells via the Nrf2/ABCA1 pathway

Recently, trimethylamine N-oxide (TMAO) has been considered a risk factor for cardiovascular disease and has a proatherogenic effect. Many studies have found that TMAO is involved in plaque oxidative stress and lipid metabolism, but the specific mechanism is still unclear. In our study, meta-analysis and bioinformatic analysis were firstly conducted in the database, and found that the effect of high plasma TMAO levels on promoting atherosclerotic plaque may be related to the expression of key antioxidant genes nuclear factor erytheroid-derived-2-like 2 (NFE2L2/Nrf2) decreased. Next, we assessed the role of Nrf2-mediated signaling pathway in TMAO-treated foam cells. Our results showed that TMAO can inhibit the expression of Nrf2 and its downstream antioxidant response element such as heme oxygenase-1 (HO-1) and glutathione peroxidase4 (GPX4), resulting in increased production of reactive oxygen species and decreased activity of superoxide dismutase, promoting oxidative stress. And TMAO can also promote lipid accumulation in foam cells by inhibiting cholesterol efflux protein expression. In addition, upregulation of Nrf2 expression partially rescues TMAO-induced oxidative stress and reduces ATP-binding cassette A1 (ABCA1)-mediated lipid accumulation. Therefore, TMAO promotes oxidative stress and lipid accumulation in macrophage foam cells through the Nrf2/ABCA1 pathway, which may provide a potential mechanism for the proatherogenic effect of TMAO.

Stroke and Vascular Cognitive Impairment: The Role of Intestinal Microbiota Metabolite TMAO

The gut microbiome interacts with the brain bidirectionally through the microbiome-gutbrain axis, which plays a key role in regulating various nervous system pathophysiological processes. Trimethylamine N-oxide (TMAO) is produced by choline metabolism through intestinal microorganisms, which can cross the blood-brain barrier to act on the central nervous system. Previous studies have shown that elevated plasma TMAO concentrations increase the risk of major adverse cardiovascular events, but there are few studies on TMAO in cerebrovascular disease and vascular cognitive impairment. This review summarized a decade of research on the impact of TMAO on stroke and related cognitive impairment, with particular attention to the effects on vascular cognitive disorders. We demonstrated that TMAO has a marked impact on the occurrence, development, and prognosis of stroke by regulating cholesterol metabolism, foam cell formation, platelet hyperresponsiveness and thrombosis, and promoting inflammation and oxidative stress. TMAO can also influence the cognitive impairment caused by Alzheimer's disease and Parkinson's disease via inducing abnormal aggregation of key proteins, affecting inflammation and thrombosis. However, although clinical studies have confirmed the association between the microbiome-gut-brain axis and vascular cognitive impairment (cerebral small vessel disease and post-stroke cognitive impairment), the molecular mechanism of TMAO has not been clarified, and TMAO precursors seem to play the opposite role in the process of poststroke cognitive impairment. In addition, several studies have also reported the possible neuroprotective effects of TMAO. Existing therapies for these diseases targeted to regulate intestinal flora and its metabolites have shown good efficacy. TMAO is probably a new target for early prediction and treatment of stroke and vascular cognitive impairment.

LncRNA-mediated Modulation of Endothelial Cells: Novel Progress in the Pathogenesis of Coronary Atherosclerotic Disease

Coronary atherosclerotic disease (CAD) is a common cardiovascular disease and an important cause of death. Moreover, endothelial cells (ECs) injury is an early pathophysiological feature of CAD, and long noncoding RNAs (lncRNAs) can modulate gene expression. Recent studies have shown that lncRNAs are involved in the pathogenesis of CAD, especially by regulating ECs. In this review, we summarize the novel progress of lncRNA-modulated ECs in the pathogenesis of CAD, including ECs proliferation, migration, adhesion, angiogenesis, inflammation, apoptosis, autophagy, and pyroptosis. Thus, as lncRNAs regulate ECs in CAD, lncRNAs will provide ideal and novel targets for the diagnosis and drug therapy of CAD.

Intestinal microbiota: a new perspective on delaying aging?

The global aging situation is severe, and the medical pressures associated with aging issues should not be underestimated. The need and feasibility of studying aging and intervening in aging have been confirmed. Aging is a complex natural physiological progression, which involves the irreversible deterioration of body cells, tissues, and organs with age, leading to enhanced risk of disease and ultimately death. The intestinal microbiota has a significant role in sustaining host dynamic balance, and the study of bidirectional communication networks such as the brain-gut axis provides important directions for human disease research. Moreover, the intestinal microbiota is intimately linked to aging. This review describes the intestinal microbiota changes in human aging and analyzes the causal controversy between gut microbiota changes and aging, which are believed to be mutually causal, mutually reinforcing, and inextricably linked. Finally, from an anti-aging perspective, this study summarizes how to achieve delayed aging by targeting the intestinal microbiota. Accordingly, the study aims to provide guidance for further research on the intestinal microbiota and aging.

Adipokines and Bacterial Metabolites: A Pivotal Molecular Bridge Linking Obesity and Gut Microbiota Dysbiosis to Target

Adipokines are essential mediators produced by adipose tissue and exert multiple biological functions. In particular, adiponectin, leptin, resistin, IL-6, MCP-1 and PAI-1 play specific roles in the crosstalk between adipose tissue and other organs involved in metabolic, immune and vascular health. During obesity, adipokine imbalance occurs and leads to a low-grade pro-inflammatory status, promoting insulin resistance-related diabetes and its vascular complications. A causal link between obesity and gut microbiota dysbiosis has been demonstrated. The deregulation of gut bacteria communities characterizing this dysbiosis influences the synthesis of bacterial substances including lipopolysaccharides and specific metabolites, generated via the degradation of dietary components, such as short-chain fatty acids, trimethylamine metabolized into trimethylamine-oxide in the liver and indole derivatives. Emerging evidence suggests that these bacterial metabolites modulate signaling pathways involved in adipokine production and action. This review summarizes the current knowledge about the molecular links between gut bacteria-derived metabolites and adipokine imbalance in obesity, and emphasizes their roles in key pathological mechanisms related to oxidative stress, inflammation, insulin resistance and vascular disorder. Given this interaction between adipokines and bacterial metabolites, the review highlights their relevance (i) as complementary clinical biomarkers to better explore the metabolic, inflammatory and vascular complications during obesity and gut microbiota dysbiosis, and (ii) as targets for new antioxidant, anti-inflammatory and prebiotic triple action strategies.

Emerging Evidence Linking the Liver to the Cardiovascular System: Liver-derived Secretory Factors

Cardiovascular diseases (CVDs) remain the leading cause of morbidity and mortality worldwide. Recently, accumulating evidence has revealed hepatic mediators, termed as liver-derived secretory factors (LDSFs), play an important role in regulating CVDs such as atherosclerosis, coronary artery disease, thrombosis, myocardial infarction, heart failure, metabolic cardiomyopathy, arterial hypertension, and pulmonary hypertension. LDSFs presented here consisted of microbial metabolite, extracellular vesicles, proteins, and microRNA, they are primarily or exclusively synthesized and released by the liver, and have been shown to exert pleiotropic actions on cardiovascular system. LDSFs mainly target vascular endothelial cell, vascular smooth muscle cells, cardiomyocytes, fibroblasts, macrophages and platelets, and further modulate endothelial nitric oxide synthase/nitric oxide, endothelial function, energy metabolism, inflammation, oxidative stress, and dystrophic calcification. Although some LDSFs are known to be detrimental/beneficial, controversial findings were also reported for many. Therefore, more studies are required to further explore the causal relationships between LDSFs and CVDs and uncover the exact mechanisms, which is expected to extend our understanding of the crosstalk between the liver and cardiovascular system and identify potential therapeutic targets. Furthermore, in the case of patients with liver disease, awareness should be given to the implications of these abnormalities in the cardiovascular system. These studies also underline the importance of early recognition and intervention of liver abnormalities in the practice of cardiovascular care, and a multidisciplinary approach combining hepatologists and cardiologists would be more preferable for such patients.

Gut microbiota and microbiota-derived metabolites in cardiovascular diseases

ABSTRACT

Cardiovascular diseases, including heart failure, coronary artery disease, atherosclerosis, aneurysm, thrombosis, and hypertension, are a great economic burden and threat to human health and are the major cause of death worldwide. Recently, researchers have begun to appreciate the role of microbial ecosystems within the human body in contributing to metabolic and cardiovascular disorders. Accumulating evidence has demonstrated that the gut microbiota is closely associated with the occurrence and development of cardiovascular diseases. The gut microbiota functions as an endocrine organ that secretes bioactive metabolites that participate in the maintenance of cardiovascular homeostasis, and their dysfunction can directly influence the progression of cardiovascular disease. This review summarizes the current literature demonstrating the role of the gut microbiota in the development of cardiovascular diseases. We also highlight the mechanism by which well-documented gut microbiota-derived metabolites, especially trimethylamine N-oxide, short-chain fatty acids, and phenylacetylglutamine, promote or inhibit the pathogenesis of cardiovascular diseases. We also discuss the therapeutic potential of altering the gut microbiota and microbiota-derived metabolites to improve or prevent cardiovascular diseases.

Roles of pyroptosis in atherosclerosis pathogenesis

Pyroptosis is a pro-inflammatory type of regulated cell death (RCD) characterized by gasdermin protein-mediated membrane pore formation, cell swelling, and rapid lysis. Recent studies have suggested that pyroptosis is closely related to atherosclerosis (AS). Previous studies reported that pyroptosis involving endothelial cells (ECs), macrophages, and smooth muscle cells (SMCs) plays an important role in the formation and development of AS. Pyroptosis not only causes local inflammation but also amplifies the inflammatory response and it aggravates plaque instability, leading to plaque rupture and thrombosis, eventually resulting in acute cardiovascular events. In this review, we clarified some novel pathways and mechanics and presented some potential drugs.

Bone marrow mesenchymal stem cellsderived exosomes stabilize atherosclerosis through inhibiting pyroptosis

OBJECTIVES

This study aimed to determine the effects of bone marrow mesenchymal stem cells (BMSCs)-derived exosomes (BMSC-EXO) on atherosclerosis (AS), and its related underlying mechanisms.

METHODS

Exosomes were isolated from mouse BMSCs, and identified by transmission electron microscopy (TEM), Nanosight (NTA), and western blot. A mouse AS model was established, and exosomes were injected into the tail vein. Total cholesterol (TC) and triglycerides (TG) were detected using their corresponding assay kits. The contents of IL-1β and IL-18 in serum were detected by ELISA. The mRNA and protein expression levels of GSDMD, Caspase1, and NLRP3 were detected by qRT-PCR and Western blot. Finally, aortic tissues in the Model and BMSC-EXO groups were sent for sequencing.

RESULTS

TEM, NTA, and western blot indicated successful isolation of exosomes. Compared with the control group, the TC, TG contents, IL-1β and IL-18 concentrations of the mice in the Model group were significantly increased; nonetheless, were significantly lower after injected with BMSC-EXO than those in the Model group (p < 0.05). Compared with the control group, the expressions of NLRP3, caspase-1 and GSDMD were significantly up-regulated in the Model group (p < 0.05), while the expressions of NLRP3, caspase-1, and GSDMD were significantly down-regulated by BMSC-EXO. By sequencing, a total of 3852 DEGs were identified between the Model and BMSC-EXO group and were significantly enriched in various biological processes and pathways related to mitochondrial function, metabolism, inflammation, and immune response.

CONCLUSION

AS can induce pyroptosis, and BMSC-EXO can reduce inflammation and alleviate the progression of AS by inhibiting NLRP3/Caspase-1/GSDMD in the pyroptosis pathway.

Pyroptosis in cardiovascular diseases: Pumping gasdermin on the fire

Pyroptosis is a form of programmed cell death associated with activation of inflammasomes and inflammatory caspases, proteolytic cleavage of gasdermin proteins (forming pores in the plasma membrane), and selective release of proinflammatory mediators. Induction of pyroptosis results in amplification of inflammation, contributing to the pathogenesis of chronic cardiovascular diseases such as atherosclerosis and diabetic cardiomyopathy, and acute cardiovascular events, such as thrombosis and myocardial infarction. While engagement of pyroptosis during sepsis-induced cardiomyopathy and septic shock is expected and well documented, we are just beginning to understand pyroptosis involvement in the pathogenesis of cardiovascular diseases with less defined inflammatory components, such as atrial fibrillation. Due to the danger that pyroptosis represents to cells within the cardiovascular system and the whole organism, multiple levels of pyroptosis regulation have evolved. Those include regulation of inflammasome priming, post-translational modifications of gasdermins, and cellular mechanisms for pore removal. While pyroptosis in macrophages is well characterized as a dramatic pro-inflammatory process, pyroptosis in other cell types within the cardiovascular system displays variable pathways and consequences. Furthermore, different cells and organs engage in local and distant crosstalk and exchange of pyroptosis triggers (oxidized mitochondrial DNA), mediators (IL-1β, S100A8/A9) and antagonists (IL-9). Development of genetic tools, such as Gasdermin D knockout animals, and small molecule inhibitors of pyroptosis will not only help us fully understand the role of pyroptosis in cardiovascular diseases but may result in novel therapeutic approaches inhibiting inflammation and progression of chronic cardiovascular diseases to reduce morbidity and mortality from acute cardiovascular events.

Lipid-laden foam cells in the pathology of atherosclerosis: shedding light on new therapeutic targets

INTRODUCTION

Lipid-laden foam cells within atherosclerotic plaques are key players in all phases of lesion development including its progression, necrotic core formation, fibrous cap thinning, and eventually plaque rupture. Manipulating foam cell biology is thus an attractive therapeutic strategy at early, middle, and even late stages of atherosclerosis. Traditional therapies have focused on prevention, especially lowering plasma lipid levels. Despite these interventions, atherosclerosis remains a major cause of cardiovascular disease, responsible for the largest numbers of death worldwide.

AREAS COVERED

Foam cells within atherosclerotic plaques are comprised of macrophages, vascular smooth muscle cells, and other cell types which are exposed to high concentrations of lipoproteins accumulating within the subendothelial intimal layer. Macrophage-derived foam cells are particularly well studied and have provided important insights into lipid metabolism and atherogenesis. The contributions of foam cell-based processes are discussed with an emphasis on areas of therapeutic potential and directions for drug development.

EXERT OPINION

As key players in atherosclerosis, foam cells are attractive targets for developing more specific, targeted therapies aimed at resolving atherosclerotic plaques. Recent advances in our understanding of lipid handling within these cells provide insights into how they might be manipulated and clinically translated to better treat atherosclerosis.

Homocysteine promotes atherosclerosis through macrophage pyroptosis via endoplasmic reticulum stress and calcium disorder

BACKGROUND

Elevated plasma homocysteine levels, known as hyperhomocysteinemia, have been identified as an independent risk factor for atherosclerosis and related cardiovascular diseases. Macrophage pyroptosis-mediated inflammation is crucial in the development of atherosclerosis, but the underlying mechanisms remain unclear.

METHODS

A hyperhomocysteinemia atherosclerotic model with ApoE^-/- mice fed with a high-methionine diet was constructed to investigate the role of plasma homocysteine in atherosclerosis. THP-1-derived macrophages were used to investigate the mechanisms by which Hcy regulates pyroptosis.

RESULTS

We found that hyperhomocysteinemia resulted in larger atherosclerotic plaques and more secretion of inflammatory cytokines, while these effects were attenuated in Caspase-1 knockdown mice. Likewise, in vitro experiments demonstrated that treatment of macrophages with homocysteine resulted in NLRP3 inflammasome activation and pyroptosis, as evidenced by cleavage of Caspase-1, production of downstream IL-1β, elevation of lactate dehydrogenase activity, and extensive propidium iodide-positive staining of cells. These were all inhibited by Caspase-1 inhibitor. In addition, excessive generation of reactive oxygen species was associated with mitochondrial dysfunction, characterized by loss of mitochondrial membrane potential and ATP synthesis. Moreover, further experiments revealed that homocysteine induced endoplasmic reticulum stress, enhanced communication between the endoplasmic reticulum and mitochondria, and consequently contributed to calcium disorder. Furthermore, the endoplasmic reticulum stress inhibitor, 4PBA, the calcium chelator, BAPTA, and calcium channel inhibitor, 2-APB significantly improved macrophage pyroptosis.

CONCLUSION

Homocysteine accelerates atherosclerosis progression by enhancing macrophages pyroptosis via promoting endoplasmic reticulum stress, endoplasmic reticulum-mitochondria coupling, and disturbing of calcium disorder.

A study of the correlation between stroke and gut microbiota over the last 20years: a bibliometric analysis

Purpose

This study intends to uncover a more thorough knowledge structure, research hotspots, and future trends in the field by presenting an overview of the relationship between stroke and gut microbiota in the past two decades.

Method

Studies on stroke and gut microbiota correlations published between 1st January 2002 and 31st December 2021 were retrieved from the Web of Science Core Collection and then visualized and scientometrically analyzed using CiteSpace V.

Results

A total of 660 papers were included in the study, among which the United States, the United Kingdom, and Germany were the leading research centers. Cleveland Clinic, Southern Medical University, and Chinese Academy of Science were the top three institutions. The NATURE was the most frequently co-cited journal. STANLEY L HAZEN was the most published author, and Tang WHW was the most cited one. The co-occurrence analysis revealed eight clusters (i.e., brain-gut microbiota axis, fecal microbiome transplantation, gut microbiota, hypertension, TMAO, ischemic stroke, neuroinflammation, atopobiosis). "gut microbiota," "Escherichia coli," "cardiovascular disease," "risk," "disease," "ischemic stroke," "stroke," "metabolism," "inflammation," and "phosphatidylcholine" were the most recent keyword explosions.

Conclusion

Findings suggest that in the next 10 years, the number of publications produced annually may increase significantly. Future research trends tend to concentrate on the mechanisms of stroke and gut microbiota, with the inflammation and immunological mechanisms, TMAO, and fecal transplantation as hotspots. And the relationship between these mechanisms and a particular cardiovascular illness may also be a future research trend.

Zuogui-Jiangtang-Yishen decoction prevents diabetic kidney disease: Intervene pyroptosis induced by trimethylamine n-oxide through the mROS-NLRP3 axis

BACKGROUND

Nowadays, diabetic kidney disease (DKD) has become one of the most threatening to the end-stage renal diseases, and the early prevention of DKD is inevitable for Diabetes Mellitus (DM) patients.

AIMS

Pyroptosis, a programmed cell death that mediates renal inflammation induced early renal injury. The trimethylamine n-oxide (TMAO) was also an independent risk factor for renal injury. Here, the associations between TMAO-induced pyroptosis and pathogenesis of DKD were studied, and the potential mechanism of Zuogui-Jiangtang-Yishen (ZGJTYS) decoction to prevent DKD was further investigated.

METHOD

Using Goto-Kakizaki (GK) rats to establish the early DKD models. The 16S-ribosomal RNA (16S rRNA) sequencing, fecal fermentation and UPLC-MS targeted metabolism techniques were combined to explore the changes of gut-derived TMAO level under the background of DKD and the effects of ZGJTYS. The proximal convoluted tubule epithelium of human renal cortex (HK-2) cells was adopted to explore the influence of pyroptosis regulated by TMAO.

RESULTS

It was demonstrated that ZGJTYS could prevent the progression of DKD by regulating glucolipid metabolism disorder, improving renal function and delaying renal pathological changes. In addition, we illustrated that gut-derived TMAO could promote DKD by activating the mROS-NLRP3 axis to induce pyroptosis. Furthermore, besides interfering with the generation of TMAO through gut microbiota, ZGJTYS inhibited TMAO-induced pyroptosis with a high-glucose environment and the underlying mechanism was related to the regulation of mROS-NLRP3 axis.

CONCLUSION

Our results suggested that ZGJTYS inhibited the activation of pyroptosis by gut-derived TMAO via the mROS-NLRP3 axis to prevent DKD.

Comorbidity of Anxiety and Hypertension: Common Risk Factors and Potential Mechanisms

Anxiety is more common in patients with hypertension, and these two conditions frequently coexist. Recently, more emphasis has been placed on determining etiology in patients with comorbid hypertension and anxiety. This review focuses on the common risk factors and potential mechanisms of comorbid hypertension and anxiety. Firstly, we analyze the common risk factors of comorbid hypertension and anxiety including age, smoking, alcohol abuse, obesity, lead, and traffic noise. The specific mechanisms underlying hypertension and anxiety were subsequently discussed, including interleukin (IL)-6 (IL-6), IL-17, reactive oxygen species (ROS), and gut dysbiosis. Increased IL-6, IL-17, and ROS accelerate the development of hypertension and anxiety. Gut dysbiosis leads to hypertension and anxiety by reducing short-chain fatty acids, vitamin D, and 5-hydroxytryptamine (5-HT), and increasing trimethylamine N-oxide (TAMO) and MYC. These shared risk factors and potential mechanisms may provide an effective strategy for treating and preventing hypertension and comorbid anxiety.

Gut microbiota and cardiac arrhythmia

One of the most prevalent cardiac diseases is cardiac arrhythmia, however the underlying causes are not entirely understood. There is a lot of proof that gut microbiota (GM) and its metabolites have a significant impact on cardiovascular health. In recent decades, intricate impacts of GM on cardiac arrythmia have been identified as prospective approaches for its prevention, development, treatment, and prognosis. In this review, we discuss about how GM and its metabolites might impact cardiac arrhythmia through a variety of mechanisms. We proposed to explore the relationship between the metabolites produced by GM dysbiosis including short-chain fatty acids(SCFA), Indoxyl sulfate(IS), trimethylamine N-oxide(TMAO), lipopolysaccharides(LPS), phenylacetylglutamine(PAGln), bile acids(BA), and the currently recognized mechanisms of cardiac arrhythmias including structural remodeling, electrophysiological remodeling, abnormal nervous system regulation and other disease associated with cardiac arrythmia, detailing the processes involving immune regulation, inflammation, and different types of programmed cell death etc., which presents a key aspect of the microbial-host cross-talk. In addition, how GM and its metabolites differ and change in atrial arrhythmias and ventricular arrhythmias populations compared with healthy people are also summarized. Then we introduced potential therapeutic strategies including probiotics and prebiotics, fecal microbiota transplantation (FMT) and immunomodulator etc. In conclusion, the GM has a significant impact on cardiac arrhythmia through a variety of mechanisms, offering a wide range of possible treatment options. The discovery of therapeutic interventions that reduce the risk of cardiac arrhythmia by altering GM and metabolites is a real challenge that lies ahead.

Pyroptosis-triggered pathogenesis: New insights on antiphospholipid syndrome

APS (antiphospholipid syndrome) is a systematic autoimmune disease presenting with the high levels of aPLs (antiphospholipid antibodies). These autoantibodies are involved in various clinical manifestations, mainly including arterial or venous thrombosis formation, proinflammatory response, and recurrent pregnant loss. Pyroptosis is a form of lytic programmed cell death, and it aggravates autoimmune diseases progression via activating NOD-like receptors, especially the NLRP3 inflammasome and its downstream inflammatory factors IL (interleukin)-1β and IL-18. However, the underlying mechanisms of pyroptosis-induced APS progression remain to be elucidated. ECs (endothelial cells), monocytes, platelets, trophoblasts, and neutrophils are prominent participants in APS development. Of significance, pyroptosis of APS-related cells leads to the excessive release of proinflammatory and prothrombotic factors, which are the primary contributors to APOs (adverse pregnancy outcomes), thrombosis formation, and autoimmune dysfunction in APS. Furthermore, pyroptosis-associated medicines have made encouraging advancements in attenuating inflammation and thrombosis. Given the potential of pyroptosis in regulating APS development, this review would systematically expound the molecular mechanisms of pyroptosis, and elaborate the role of pyroptosis-mediated cellular effects in APS progression. Lastly, the prospective therapeutic approaches for APS would be proposed based on the regulation of pyroptosis.

Tongxinluo attenuates atherosclerosis by inhibiting ROS/NLRP3/caspase-1-mediated endothelial cell pyroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Tongxinluo (TXL) is one of the most common traditional Chinese medicines and plays a vital role in treating atherosclerosis (AS). Endothelial cell (EC) pyroptosis plays a crucial role in the development of AS. Previous research revealed the inhibitory function of TXL in EC apoptosis and autophagy. However, whether TXL can inhibit the pyroptosis of ECs has not been determined.

AIM OF THE STUDY

To explore the influence of TXL on EC pyroptosis and determine its underlying mechanism of action in AS.

MATERIALS AND METHODS

The TXL components were determined by ultra-performance liquid chromatography coupled with a photodiode array detector. We used ApoE^-/- mice to establish a disease model of AS. After treatment with TXL, we recorded pathological changes in the mice and performed immunofluorescence staining of mice aortas. We also measured protein and gene levels to explore the influence of TXL on pyroptosis in vivo. The model was established by stimulating mouse aortic endothelial cells (MAECs) with oxidized low-density lipoprotein (ox-LDL) and analyzing the effect of TXL on pyroptosis by Western blotting (WB), real-time PCR (RT-PCR), and flow cytometry (FCM). We also investigated the impact of TXL on reactive oxygen species (ROS) by FCM and WB.

RESULTS

Ten major components of TXL were detected. The vivo results showed that TXL inhibited the development of AS and decreased EC pyroptosis, the activation of caspase-1, and the release of inflammatory cytokines. The vitro experiments showed that TXL significantly reduced the extent of injury to MAECs by oxidized LDL (ox-LDL). TXL reversed the high expression of gasdermin D and other proteins induced by ox-LDL and had a significant synergistic effect with the caspase-1 inhibitor VX-765. We also confirmed that TXL decreased the accumulation of ROS and the expression levels of its essential regulatory proteins Cox2 and iNOS. When ROS accumulation was reduced, EC pyroptotic damage was reduced accordingly.

CONCLUSION

Our results indicated that TXL inhibited EC pyroptosis in AS. Reducing the accumulation of ROS may be the essential mechanism of AS inhibition by TXL.

The role of ROS-induced pyroptosis in CVD

Cardiovascular disease (CVD) is the number one cause of death in the world and seriously threatens human health. Pyroptosis is a new type of cell death discovered in recent years. Several studies have revealed that ROS-induced pyroptosis plays a key role in CVD. However, the signaling pathway ROS-induced pyroptosis has yet to be fully understood. This article reviews the specific mechanism of ROS-mediated pyroptosis in vascular endothelial cells, macrophages, and cardiomyocytes. Current evidence shows that ROS-mediated pyroptosis is a new target for the prevention and treatment of cardiovascular diseases such as atherosclerosis (AS), myocardial ischemia-reperfusion injury (MIRI), and heart failure (HF).

Gut Molecules in Cardiometabolic Diseases: The Mechanisms behind the Story

Atherosclerotic cardiovascular disease is the most common cause of morbidity and mortality worldwide. Diabetes mellitus increases cardiovascular risk. Heart failure and atrial fibrillation are associated comorbidities that share the main cardiovascular risk factors. The use of incretin-based therapies promoted the idea that activation of alternative signaling pathways is effective in reducing the risk of atherosclerosis and heart failure. Gut-derived molecules, gut hormones, and gut microbiota metabolites showed both positive and detrimental effects in cardiometabolic disorders. Although inflammation plays a key role in cardiometabolic disorders, additional intracellular signaling pathways are involved and could explain the observed effects. Revealing the involved molecular mechanisms could provide novel therapeutic strategies and a better understanding of the relationship between the gut, metabolic syndrome, and cardiovascular diseases.

Contribution of Trimethylamine N-Oxide (TMAO) to Chronic Inflammatory and Degenerative Diseases

Trimethylamine N-oxide (TMAO) is a metabolite produced by the gut microbiota and has been mainly associated with an increased incidence of cardiovascular diseases (CVDs) in humans. There are factors that affect one's TMAO level, such as diet, drugs, age, and hormones, among others. Gut dysbiosis in the host has been studied recently as a new approach to understanding chronic inflammatory and degenerative diseases, including cardiovascular diseases, metabolic diseases, and Alzheimer's disease. These disease types as well as COVID-19 are known to modulate host immunity. Diabetic and obese patients have been observed to have an increase in their level of TMAO, which has a direct correlation with CVDs. This metabolite is attributed to enhancing the inflammatory pathways through cholesterol and bile acid dysregulation, promoting foam cell formation. Additionally, TMAO activates the transcription factor NF-κB, which, in turn, triggers cytokine production. The result can be an exaggerated inflammatory response capable of inducing endoplasmic reticulum stress, which is responsible for various diseases. Due to the deleterious effects that this metabolite causes in its host, it is important to search for new therapeutic agents that allow a reduction in the TMAO levels of patients and that, thus, allow patients to be able to avoid a severe cardiovascular event. The present review discussed the synthesis of TMAO and its contribution to the pathogenesis of various inflammatory diseases.

Gut Microbiota-Derived TMAO: A Causal Factor Promoting Atherosclerotic Cardiovascular Disease?

Trimethylamine-N-oxide (TMAO) is the main diet-induced metabolite produced by the gut microbiota, and it is mainly eliminated through renal excretion. TMAO has been correlated with an increased risk of atherosclerotic cardiovascular disease (ASCVD) and related complications, such as cardiovascular mortality or major adverse cardiovascular events (MACE). Meta-analyses have postulated that high circulating TMAO levels are associated with an increased risk of cardiovascular events and all-cause mortality, but the link between TMAO and CVD remains not fully consistent. The results of prospective studies vary depending on the target population and the outcome studied, and the adjustment for renal function tends to decrease or reverse the significant association between TMAO and the outcome studied, strongly suggesting that the association is substantially mediated by renal function. Importantly, one Mendelian randomization study did not find a significant association between genetically predicted higher TMAO levels and cardiometabolic disease, but another found a positive causal relationship between TMAO levels and systolic blood pressure, which-at least in part-could explain the link with renal function. The mechanisms by which TMAO can increase this risk are not clearly elucidated, but current evidence indicates that TMAO induces cholesterol metabolism alterations, inflammation, endothelial dysfunction, and platelet activation. Overall, there is no fully conclusive evidence that TMAO is a causal factor of ASCVD, and, especially, whether TMAO induces or just is a marker of hypertension and renal dysfunction requires further study.

Aorta- and liver-generated TMAO enhances trained immunity for increased inflammation via ER stress/mitochondrial ROS/glycolysis pathways

We determined whether gut microbiota-produced trimethylamine (TMA) is oxidized into trimethylamine N-oxide (TMAO) in nonliver tissues and whether TMAO promotes inflammation via trained immunity (TI). We found that endoplasmic reticulum (ER) stress genes were coupregulated with MitoCarta genes in chronic kidney diseases (CKD); TMAO upregulated 190 genes in human aortic endothelial cells (HAECs); TMAO synthesis enzyme flavin-containing monooxygenase 3 (FMO3) was expressed in human and mouse aortas; TMAO transdifferentiated HAECs into innate immune cells; TMAO phosphorylated 12 kinases in cytosol via its receptor PERK and CREB, and integrated with PERK pathways; and PERK inhibitors suppressed TMAO-induced ICAM-1. TMAO upregulated 3 mitochondrial genes, downregulated inflammation inhibitor DARS2, and induced mitoROS, and mitoTEMPO inhibited TMAO-induced ICAM-1. β-Glucan priming, followed by TMAO restimulation, upregulated TNF-α by inducing metabolic reprogramming, and glycolysis inhibitor suppressed TMAO-induced ICAM-1. Our results have provided potentially novel insights regarding TMAO roles in inducing EC activation and innate immune transdifferentiation and inducing metabolic reprogramming and TI for enhanced vascular inflammation, and they have provided new therapeutic targets for treating cardiovascular diseases (CVD), CKD-promoted CVD, inflammation, transplantation, aging, and cancer.

The role of pyroptosis in endothelial dysfunction induced by diseases

Most organs in the body rely on blood flow, and vesicular damage is the leading cause of injury in multiple organs. The endothelium, as the barriers of vessels, play a critical role in ensuring vascular homeostasis and angiogenesis. The rapid development of risk factors in endothelial injuries has been seen in the past decade, such as smoking, infectious, and diabetes mellites. Pyroptotic endothelium is an inflammatory mode of governed endothelial cell death that depend on the metabolic disorder and severe infectious such as atherosclerosis, and sepsis-related acute lung injury, respectively. Pyroptotic endothelial cells need GSDMD cleaved into N- and C-terminal by caspase1, and the cytokines are released by a pore constructed by the N-terminal of GSDMD in the membrane of ECs, finally resulting in severe inflammation and pyroptotic cell death. This review will focus on the patho-physiological and pharmacological pathways of pyroptotic endothelial metabolism in diseases. Overall, this review indicates that pyroptosis is a significant risk factor in diseases and a potential drug target in related diseases.

The role of pyroptosis in endothelial dysfunction induced by diseases

Most organs in the body rely on blood flow, and vesicular damage is the leading cause of injury in multiple organs. The endothelium, as the barriers of vessels, play a critical role in ensuring vascular homeostasis and angiogenesis. The rapid development of risk factors in endothelial injuries has been seen in the past decade, such as smoking, infectious, and diabetes mellites. Pyroptotic endothelium is an inflammatory mode of governed endothelial cell death that depend on the metabolic disorder and severe infectious such as atherosclerosis, and sepsis-related acute lung injury, respectively. Pyroptotic endothelial cells need GSDMD cleaved into N- and C-terminal by caspase1, and the cytokines are released by a pore constructed by the N-terminal of GSDMD in the membrane of ECs, finally resulting in severe inflammation and pyroptotic cell death. This review will focus on the patho-physiological and pharmacological pathways of pyroptotic endothelial metabolism in diseases. Overall, this review indicates that pyroptosis is a significant risk factor in diseases and a potential drug target in related diseases.

Choline and trimethylamine N-oxide impair metabolic activation of and platelet response to clopidogrel through activation of the NOX/ROS/Nrf2/CES1 pathway

BACKGROUND

Trimethylamine N-oxide (TMAO), a gut microbe-generated metabolite, elicits thrombotic events by enhancing platelet reactivity; however, no studies have reported the effects of TMAO on the metabolism of and response to clopidogrel.

OBJECTIVES

To determine whether choline and TMAO could significantly impair metabolic activation of and platelet response to clopidogrel in choline- or TMAO-fed mice and the mechanisms involved.

METHODS

Male mice were fed with vehicle control (Ctrl), TMAO, choline alone or in combination with 3,3-dimethyl-1-butanol, N-acetyl-L-cysteine, or ML385 for 14 days and then treated with Ctrl or a single oral dose of clopidogrel. Plasma TMAO, protein levels of clopidogrel-metabolizing enzymes in the liver, plasma concentrations of clopidogrel and its metabolites, and adenosine diphosphate-induced platelet aggregation and activation were measured. In addition, HepG2 cells were treated with Ctrl or TMAO alone or in combination with N-acetyl-L-cysteine, ML385, or apocynin, and CES1, reactive oxygen species (ROS), and Nrf2 protein levels were measured, respectively.

RESULTS

TMAO significantly increased Ces1 protein expression and activity and clopidogrel hydrolysis in the liver as well as intracellular ROS and CES1 levels and Nrf2 nucleus translocation in HepG2 cells but decreased the formation of clopidogrel active metabolite and impaired platelet response to clopidogrel. Furthermore, concomitant use of 3,3-dimethyl-1-butanol, N-acetyl-L-cysteine, or ML385 effectively reversed choline- or TMAO-induced impairment of inhibition of platelet aggregation by clopidogrel in mice, respectively.

CONCLUSIONS

Choline and TMAO impair the metabolic activation of and platelet response to clopidogrel through the activation of the NOX-dependent ROS/Nrf2/CES1 pathway, suggesting novel strategies for overcoming clopidogrel resistance from bench to bedside.

Gut microbiota may mediate the impact of chronic apical periodontitis on atherosclerosis in apolipoprotein E-deficient mice

AIM

There are growing evidences linking chronic apical periodontitis (CAP) to atherosclerosis. Gut microbiota is found to be involved in the development of atherosclerosis. Recent studies have shown that CAP could change the diversity and composition of the gut microbiota. It was therefore, we hypothesized that gut microbiota and its metabolites could mediate the impact of CAP on atherosclerosis.

METHODOLOGY

Twenty-four 5-week-old lipoprotein E knockout (apoE^-/- ) mice were randomly divided into four groups: the CAP group, Con group, Co-CAP (cohoused with CAP) and Co-Con (cohoused with Con) group. In the CAP group, sterile cotton wool containing P. gingivalis was placed into the exposed pulp chamber, followed by coronal resin-based composite restoration of the bilateral maxillary first and second molars. In the Con group, a sham operation was performed. Biweekly, mice in the CAP group were anaesthetised to check the sealing of coronal access. Meanwhile, the animals in the Con group were anaesthetised. The cohousing approach was used to introduce gut microbiota from the CAP and Con groups into the Co-CAP and Co-Con groups, respectively. Alterations in the abundance and diversity of the gut microbiota were detected using 16S rRNA sequencing, Oil-red O staining was used to demonstrate the extent of lesions, and serum levels of trimethylamine N-oxide (TMAO), and immunohistochemistry of flavin-containing monooxygenase 3 (FMO3) in liver were used to assess TMAO-related metabolic alterations.

RESULTS

Alterations of alpha and beta diversity were shown both in the CAP and the Co-CAP groups. Moreover, the percentage of atherosclerotic lesion area increased in the CAP and Co-CAP groups (p < .05). Linear discriminant analysis effect size (LEfSe) at the family level found the increases of Lachnospiraceae and Ruminococcaceae (p < .05), which were positively correlated with serum TMAO levels (p < .05). In the redundancy analysis technique (RDA), serum levels of TMAO were positively associated with the atherosclerotic lesions. Co-occurrence analysis revealed that the relative abundances of Lachnospiraceae and Porphyromonadacae were positively correlated with both the percentage of lesion area and TMAO level (p < .05).

CONCLUSION

Thus, within the limitations of this study, the data suggest that the gut microbiota can mediate the effects of CAP on atherosclerosis.

The emerging role of pyroptosis-related inflammasome pathway in atherosclerosis

Atherosclerosis (AS), a chronic sterile inflammatory disorder, is one of the leading causes of mortality worldwide. The dysfunction and unnatural death of plaque cells, including vascular endothelial cells (VEC), macrophages, and vascular smooth muscle cells (VSMC), are crucial factors in the progression of AS. Pyroptosis was described as a form of cell death at least two decades ago. It is featured by plasma membrane swelling and rupture, cell lysis, and consequent robust release of cytosolic contents and pro-inflammatory mediators, including interleukin-1β (IL-1β), IL-18, and high mobility group box 1 (HMGB1). Pyroptosis of plaque cells is commonly observed in the initiation and development of AS, and the levels of pyroptosis-related proteins are positively correlated with plaque instability, indicating the crucial contribution of pyroptosis to atherogenesis. Furthermore, studies have also identified some candidate anti-atherogenic agents targeting plaque cell pyroptosis. Herein, we summarize the research progress in understating (1) the discovery and definition of pyroptosis; (2) the characterization and molecular mechanisms of pyroptosis; (3) the regulatory mechanisms of pyroptosis in VEC, macrophage, and VSMC, as well as their potential role in AS progression, aimed at providing therapeutic targets for the prevention and treatment of AS.

Mitochondrial dysfunction in vascular endothelial cells and its role in atherosclerosis

The mitochondria are essential organelles that generate large amounts of ATP via the electron transport chain (ECT). Mitochondrial dysfunction causes reactive oxygen species accumulation, energy stress, and cell death. Endothelial mitochondrial dysfunction is an important factor causing abnormal function of the endothelium, which plays a central role during atherosclerosis development. Atherosclerosis-related risk factors, including high glucose levels, hypertension, ischemia, hypoxia, and diabetes, promote mitochondrial dysfunction in endothelial cells. This review summarizes the physiological and pathophysiological roles of endothelial mitochondria in endothelial function and atherosclerosis.

Epigenetics and Gut Microbiota Crosstalk: A potential Factor in Pathogenesis of Cardiovascular Disorders

Cardiovascular diseases (CVD) are the leading cause of mortality, morbidity, and "sudden death" globally. Environmental and lifestyle factors play important roles in CVD susceptibility, but the link between environmental factors and genetics is not fully established. Epigenetic influence during CVDs is becoming more evident as its direct involvement has been reported. The discovery of epigenetic mechanisms, such as DNA methylation and histone modification, suggested that external factors could alter gene expression to modulate human health. These external factors also influence our gut microbiota (GM), which participates in multiple metabolic processes in our body. Evidence suggests a high association of GM with CVDs. Although the exact mechanism remains unclear, the influence of GM over the epigenetic mechanisms could be one potential pathway in CVD etiology. Both epigenetics and GM are dynamic processes and vary with age and environment. Changes in the composition of GM have been found to underlie the pathogenesis of metabolic diseases via modulating epigenetic changes in the form of DNA methylation, histone modifications, and regulation of non-coding RNAs. Several metabolites produced by the GM, including short-chain fatty acids, folates, biotin, and trimethylamine-N-oxide, have the potential to regulate epigenetics, apart from playing a vital role in normal physiological processes. The role of GM and epigenetics in CVDs are promising areas of research, and important insights in the field of early diagnosis and therapeutic approaches might appear soon.

Positive Association of Plasma Trimethylamine-N-Oxide and Atherosclerosis in Patient with Acute Coronary Syndrome

Aim. Atherosclerosis is the major cause of acute coronary syndrome (ACS) which is a significant contributor to both morbidity and mortality in the world. The microbiome-derived metabolite trimethylamine-N-oxide (TMAO) has aroused great interest and controversy as a risk factor of atherosclerosis. Therefore, in this study, we aimed at investigating whether plasma TMAO can be a risk factor of atherosclerosis in coronary artery of patients with ACS and how this relates to lipids and proinflammatory cytokines in plasma. Methods. We enrolled consecutive patients with ACS who underwent percutaneous coronary intervention (PCI). Gensini scoring was used to evaluate angiographic atherosclerosis in the coronary artery of the patients. 13 patients were divided into low ( $\text{Gensini}\text{score}<25$ ), 33 into intermediate (Gensini score 25-50), and 81 into severe atherosclerosis (Gensini score ≥50). Plasma TMAO, vasculitis factors, and cardiovascular biomarkers were measured by clinical biochemistry, intima-media thickness (IMT) of carotid artery was determined by the Color Doppler ultrasound, and the atherosclerotic lesion in coronary artery was assessed in PCI. Results. Plasma TMAO concentrations were positively associated with Gensini score ( $\text{OR}=0.629$ , $p<0.001$ ) and Gensini subgroup ( $\text{R}=0.604$ , $p<0.0$ 01). Plasma TMAO concentrations in patients with severe coronary atherosclerosis were higher than those of patients with moderate coronary atherosclerosis, and the plasma TMAO concentrations of patients with moderate coronary atherosclerosis were higher than those of patients with mild coronary atherosclerosis, the difference was statistically significant [4.73 (3.13, 4.62) versus 1.13 (0.63, 3.34) versus 0.79 (0.20, 1.29), $p<0.001$ ], respectively. Furthermore, ROC analysis showed that plasma TMAO could identify the severity of atherosclerosis ( $p<0.001$ ). The AUC of TMAO for severe atherosclerosis was 0.852 ( $95\%\text{CI}=0.779-0.925$ ). The sensitivity and specificity of TMAO for identifying severe atherosclerosis are 96.3% and 63.0% when the cut-off value of TMAO was set at 1.2715 pg/ml. Furthermore, logistic regression analysis showed plasma TMAO concentrations were positively associated with severity of atherosclerosis in coronary artery ( $\text{OR}=1.934$ , $95\%\text{CI}=1.522-2.459$ , $p<0.001$ ). For all that, negatively association was observed between TMAO and age ( $\text{OR}=-0.224$ , $p<0.05$ ), B-type natriuretic peptide (BNP) ( $\text{OR}=-0.175$ , $p<0.05$ ), and interleukin-8 (IL-8) ( $\text{OR}=-0.324$ , $p<0.001$ ), while positive association was observed between TMAO and nitric oxide (NO) ( $\text{OR}=0.234$ , $p<0.01$ ). However, there is no obvious association was observed between Gensini score and cardiovascular biomarkers, vasculitis factors, and carotid IMT, respectively. Conclusion. Our cross-sectional observation suggested that plasma TMAO concentrations positively associated with coronary atherosclerosis in ACS patients and serve as a risk factor for severe atherosclerosis. Plasma TMAO also correlated with age, BNP, IL-8, and NO. However, no obvious association was found between atherosclerosis with vasculitis factors and cardiovascular biomarkers in this study, and there was no conclusive evidence showing TMAO enhance atherosclerosis via regulation of inflammation or lipid.

A novel anti-atherosclerotic mechanism of quercetin: Competitive binding to KEAP1 via Arg483 to inhibit macrophage pyroptosis

Natural antioxidants represented by quercetin have been documented to be effective against atherosclerosis. However, the related mechanisms remain largely unclear. In this study, we identified a novel anti-atherosclerotic mechanism of quercetin inhibiting macrophage pyroptosis by activating NRF2 through binding to the Arg483 site of KEAP1 competitively. In ApoE-/- mice fed with high fat diet, quercetin administration attenuated atherosclerosis progression by reducing oxidative stress level and suppressing macrophage pyroptosis. At the cellular level, quercetin suppressed THP-1 macrophage pyroptosis induced by ox-LDL, demonstrated by inhibiting NLRP3 inflammasome activation and reducing ROS level, while these effects were reversed by the specific NRF2 inhibitor (ML385). Mechanistically, quercetin promoted NRF2 to dissociate from KEAP1, enhanced NRF2 nuclear translocation as well as transcription of downstream antioxidant protein. Molecular docking results suggested that quercetin could bind with KEAP1 at Arg415 and Arg483. In order to verify the binding sites, KEAP1 mutated at Arg415 and Arg483 to Ser (R415S and R483S) was transfected into THP-1 macrophages, and the anti-pyroptotic effect of quercetin was abrogated by Arg483 mutation, but not Arg415 mutation. Furthermore, after administration of adeno associated viral vector (AAV) with AAV-KEAP1-R483S, the anti-atherosclerotic effects of quercetin were almost abolished in ApoE-/- mice. These findings proved quercetins suppressed macrophage pyroptosis by targeting KEAP1/NRF2 interaction, and provided reliable data on the underlying mechanism of natural antioxidants to protect against atherosclerosis.

Trimethylamine-N-Oxide Promotes Osteoclast Differentiation and Bone Loss via Activating ROS-Dependent NF-κB Signaling Pathway

Trimethylamine-N-oxide (TMAO), an important gut microbiota (GM)-derived metabolite, has been shown to be abnormally increased in osteoporosis. However, the role and underlying mechanism of TMAO in regulating bone loss during osteoporosis have not been fully investigated. In the current study, we found that 100–400 μM TMAO dose-dependently enhanced TRAP-positive osteoclasts, F-actin ring formation, and resorption area on bovine bone slices and up-regulated osteoclast-related gene expression (Calcr, Traf6, Dcstamp, Acp5, C-Fos, and NFATc1). Western blotting validated that TMAO not only activated NF-κB signaling pathway but also stimulated c-Fos and NFATc1 protein expression in a dose-dependent manner. Furthermore, BAY 11-7082, an NF-κB inhibitor, pretreatment markedly suppressed TRAP-positive osteoclast formation and osteoclast-related genes under TMAO treatment. BAY 11-7082 also inhibited p-p65/p65, c-Fos, and NFATc1 protein expression promoted by TMAO. Moreover, TMAO significantly increased ROS production, which was inhibited by N-acetylcysteine (NAC), an ROS antagonist. In addition, we proved that NAC pretreatment could inhibit TMAO-promoted NF-κB activation. NAC also suppressed TRAP-positive osteoclast formation, osteoclast-related gene expression, and protein expression of c-Fos and NFATc1 under TMAO treatment. In vivo studies showed significantly decreased bone mass and increased TRAP-positive osteoclasts in TMAO-treated C57BL/6 mice. Moreover, western-blotting and immunohistochemical staining showed that TMAO administration markedly stimulated NF-κB p65 expression. Additionally, TMAO administration significantly promoted the gene and protein expression of C-Fos and NFATc1. In conclusion, TMAO could promote osteoclast differentiation and induce bone loss in mice by activating the ROS-dependent NF-κB signaling pathway.

NLRP3 Inflammasome/Pyroptosis: A Key Driving Force in Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM), a serious diabetic complication, is a kind of low-grade inflammatory cardiovascular disorder. Due to the high risk of morbidity and mortality, DCM has demanded the attention of medical researchers worldwide. The pathophysiological nature of DCM is intricate, and the genesis and development of which are a consequence of the coaction of many factors. However, the exact pathogenesis mechanism of DCM remains unclear. Pyroptosis is a newly identified programmed cell death (PCD) that is directly related to gasdermin D(GSDMD). It is characterized by pore formation on the cell plasma membrane, the release of inflammatory mediators, and cell lysis. The initiation of pyroptosis is closely correlated with NOD-like receptor 3 (NLRP3) activation, which activates caspase-1 and promotes the cleaving of GSDMD. In addition to adjusting the host’s immune defense, NLRP3 inflammasome/pyroptosis plays a critical role in controlling the systemic inflammatory response. Recent evidence has indicated that NLRP3 inflammasome/pyroptosis has a strong link with DCM. Targeting the activation of NLRP3 inflammasome or pyroptosis may be a hopeful therapeutic strategy for DCM. The focus of this review is to summarize the relevant mechanisms of pyroptosis and the relative contributions in DCM, highlighting the potential therapeutic targets in this field.

Integrated pyroptosis measurement and metabolomics to elucidate the effect and mechanism of tangzhiqing on atherosclerosis

Tangzhiqing formula (TZQ) is a traditional Chinese medicine prescribed to treat glucose and lipid metabolism disorders. A significant effect of TZQ on diabetes and hyperlipidemia has been demonstrated, but its effect on atherosclerosis (AS) remains unknown. This study combines pyroptosis with metabolomics to elucidate the effect and mechanism of TZQ on AS. A model of AS was developed using ApoE^−/− mice fed a high-fat diet for 8 weeks. After 6 weeks of atorvastatin (Ator) or TZQ treatment, aortic lumen diameter, aortic lesion size, serum lipid profile, cytokines, and Nod-like receptor protein 3 (NLRP3) inflammasome-mediated pyroptosis were analyzed. Serum metabolomics profiles were obtained to examine the effect of TZQ on AS and the correlation between pyroptosis and metabolites was further analyzed. As a result, TZQ significantly reduced the diameter of the common carotid artery during diastole and the blood flow velocity in the aorta during systole; reduced blood lipid levels, arterial vascular plaques, and the release of inflammatory cytokines; and inhibited the NLRP3 inflammasome-mediated pyroptosis. According to metabolomics profiling, TZQ is engaged in the treatment of AS via altering arachidonic acid metabolism, glycerophospholipid metabolism, steroid hormone production, and unsaturated fatty acid biosynthesis. The cytochrome P450 enzyme family and cyclooxygenase 2 (COX-2) are two major metabolic enzymes associated with pyroptosis.

Microbiome systems biology advancements for natural well-being

Throughout the years all data from epidemiological, physiological and omics have suggested that the microbial communities play a considerable role in modulating human health. The population of microorganisms residing in the human intestine collectively known as microbiota presents a genetic repertoire that is higher in magnitude than the human genome. They play an essential role in host immunity and neuronal signaling. Rapid enhancement of sequence based screening and development of humanized gnotobiotic model has sparked a great deal of interest among scientists to probe the dynamic interactions of the commensal bacteria. This review focuses on systemic analysis of the gut microbiome to decipher the complexity of the host-microbe intercommunication and gives a special emphasis on the evolution of targeted precision medicine through microbiome engineering. In addition, we have also provided a comprehensive description of how interconnection between metabolism and biochemical reactions in a specific organism can be obtained from a metabolic network or a flux balance analysis and combining multiple datasets helps in the identification of a particular metabolite. The review highlights how genetic modification of the critical components and programming the resident microflora can be employed for targeted precision medicine. Inspite of the ongoing debate on the utility of gut microbiome we have explored on the probable new therapeutic avenues like FMT (Fecal microbiota transplant) can be utilized. This review also recapitulates integrating human-relevant 3D cellular models coupled with computational models and the metadata obtained from interventional and epidemiological studies may decipher the complex interactome of diet-microbiota-disease pathophysiology. In addition, it will also open new avenues for the development of therapeutics derived from microbiome or implementation of personalized nutrition. In addition, the identification of biomarkers can also help towards the development of new diagnostic tools and eventually will lead to strategic management of the disease. Inspite of the ongoing debate on the utility of the gut microbiome we have explored how probable new therapeutic avenues like FMT (Fecal microbiota transplant) can be utilized. This review also summarises integrating human-relevant 3D cellular models coupled with computational models and the metadata obtained from interventional and epidemiological studies may decipher the complex interactome of diet- microbiota-disease pathophysiology. In addition, it will also open new avenues for the development of therapeutics derived from the microbiome or implementation of personalized nutrition. In addition, the identification of biomarkers can also help towards the development of new diagnostic tools and eventually will lead to strategic management of disease.

Trimethylamine-N-oxide (TMAO) promotes balloon injury-induced neointimal hyperplasia via upregulating Beclin1 and impairing autophagic flux

BACKGROUND AND AIMS

TMAO is a microbiota-dependent metabolite associated with increased risk of various cardiovascular diseases. However, the relationship between TMAO and vascular injury-related neointimal hyperplasia is unclear. This study aimed to explore whether TMAO promotes neointimal hyperplasia after balloon injury and elucidate the underlying mechanism.

METHODS AND RESULTS

Through hematoxylin and eosin staining and immunohistochemistry staining, we found that supplementary TMAO promoted balloon injury-induced neointimal hyperplasia, while reducing TMAO by antibiotic administration produced the opposite result. TMAO showed limited effect on rat aortic vascular smooth muscle cells (RAOSMCs) proliferation and migration. However, TMAO notably induced dysfunction of rat aortic vascular endothelial cells (RAOECs) in vitro and attenuated reendothelialization of carotid arteries after balloon injury in vivo. Autophagic flux was measured by fluorescent mRFP-GFP-LC3, transmission electron microscopy, and western blot. TMAO impaired autophagic flux, as evidenced by the accumulation of p62 and LC3II and high autophagosome to autolysosome ratios. Furthermore, we confirmed that Beclin1 level increased in TMAO-treated RAOECs and carotid arteries. Knocking down Beclin1 alleviated TMAO-induced autophagic flux impairment and neointimal hyperplasia.

CONCLUSIONS

TMAO promoted neointimal hyperplasia through Beclin1-induced autophagic flux blockage, suggesting that TMAO is a potential target for improvement of vascular remodeling after injury.

Therapeutic potential of traditional Chinese medicine against atherosclerosis: Targeting trimethylamine N-oxide

BACKGROUND

Recent studies have shown that plasma trimethylamine-N-oxide (TMAO) level is highly correlated with the risk of atherosclerosis (AS), and the elevated level is significantly positively correlated with the incidence of AS.

PURPOSE

The purpose of this article is to offer a useful summary of the correlation between TMAO and AS, and the effect of herbal monomers, herbal extracts, and formulas on anti-atherosclerosis mediated by TMAO.

METHOD

The data contained in this article comes from PubMed, Web of Science, and China National Knowledge Infrastructure.

RESULTS

This review discusses the main mechanism of AS induced by TMAO, including endothelial dysfunction, macrophage foaming, platelet reactivity, and cholesterol metabolism, and summarizes 6 herb monomers, 5 herb extracts, and 2 formulas that have been tested for their anti-TMAO activity.

CONCLUSION

The current understanding of possible ways to reduce TMAO generation is discussed, with the effect and potential of herb monomers, herb extracts, and formulas highlighted.

Trimethylamine N-oxide promotes demyelination in spontaneous hypertension rats through enhancing pyroptosis of oligodendrocytes

Background

Hypertension is a leading risk factor for cerebral small vessel disease (CSVD), a brain microvessels dysfunction accompanied by white matter lesions (WML). Trimethylamine N-oxide (TMAO), a metabolite of intestinal flora, is correlated with cardiovascular and aging diseases. Here, we explored the effect of TMAO on the demyelination of WML.

Methods

Spontaneous hypertension rats (SHRs) and primary oligodendrocytes were used to explore the effect of TMAO on demyelination in vivo and in vitro. T2-weighted magnetic resonance imaging (MRI) was applied to characterize the white matter hyperintensities (WMH) in rats. TMAO level was evaluated using LC-MS/MS assay. The histopathological changes of corpus callosum were measured by hematoxylin-eosin and luxol fast blue staining. And the related markers were detected by IHC, IF and western blot assay. Mito Tracker Red probe, DCFH-DA assay, flow cytometry based on JC-1 staining and Annexin V-FITC/PI double staining were conducted to evaluate the mitochondrial function, intracellular ROS levels and cell apoptosis.

Results

SHRs exhibited stronger WMH signals and a higher TMAO level than age-matched normotensive Wistar-kyoto rats (WKY). The corpus callosum region of SHR showed decreased volumes and enhanced demyelination when treated with TMAO. Furthermore, TMAO significantly elevated ROS production and induced NLRP3 inflammasome and impairment of mitochondrial function of oligodendrocytes. More importantly, TMAO enhanced the pyroptosis-related inflammatory death of oligodendrocytes.

Conclusion

TMAO could cross the blood-brain barrier (BBB) and promote oligodendrocytes pyroptosis via ROS/NLRP3 inflammasome signaling and mitochondrial dysfunction to promote demyelination, revealing a new diagnostic marker for WML under hypertension.

Gut-Flora-Dependent Metabolite Trimethylamine-N-Oxide Promotes Atherosclerosis-Associated Inflammation Responses by Indirect ROS Stimulation and Signaling Involving AMPK and SIRT1

Trimethylamine-N-oxide (TMAO), a gut-microbiota-dependent metabolite after ingesting dietary choline, has been identified as a novel risk factor for atherosclerosis through inducing vascular inflammation. However, the underlying molecular mechanism is poorly understood. Using an in vitro vascular cellular model, we found that the TMAO-induced inflammation responses were correlated with an elevation of ROS levels and downregulation of SIRT1 expression in VSMCs and HUVECs. The overexpression of SIRT1 could abrogate both the stimulation of ROS and inflammation. Further studies revealed that AMPK was also suppressed by TMAO and was a mediator upstream of SIRT1. Activation of AMPK by AICAR could reduce TMAO-induced ROS and inflammation. Moreover, the GSH precursor NAC could attenuate TMAO-induced inflammation. In vivo studies with mice models also showed that choline-induced production of TMAO and the associated glycolipid metabolic changes leading to atherosclerosis could be relieved by NAC and a probiotic LP8198. Collectively, the present study revealed an unrecognized mechanistic link between TMAO and atherosclerosis risk, and probiotics ameliorated TMAO-induced atherosclerosis through affecting the gut microbiota. Consistent with previous studies, our data confirmed that TMAO could stimulate inflammation by modulating cellular ROS levels. However, this was not due to direct cytotoxicity but through complex signaling pathways involving AMPK and SIRT1.

Microbial metabolites and heart failure: Friends or enemies?

Heart failure (HF), a global health issue characterized by structural or functional cardiac dysfunction, which was found to be associated with the gut microbiome recently. Although multiple studies suggested that the gut microbiome may have an impact on the development of cardiovascular diseases, the underlying mechanism of the gut microbiome in HF remains unclear. The study of metabolites from gut microbiota influenced by dietary nutrition uptake suggested that gut microbiota may affect the process of HF. However, on the basis of the microbiota’s complicated roles and their interactions with metabolites, studies of microbial metabolites in HF had rarely been described so far. In this review, we focused on dietary nutrition-related factors that were involved in the development and progression of HF, such as trimethylamine N-oxide (TMAO), short-chain fatty acids (SCFAs), and bile acids (BAs), to summarize their advances and several potential targets in HF. From a therapeutic standpoint, we discussed microbial metabolites as a potential strategy and their applications in HF as well.

Talaromyces marneffei activates the AIM2-caspase-1/-4-GSDMD axis to induce pyroptosis in hepatocytes

Talaromyces marneffei tends to induce systemic infection in immunocompromised individuals, which is one of the causes of the high mortality. The underlying molecular mechanisms of T.marneffei-induced abnormal liver function are still poorly understood. In this study, we found that T.marneffei-infected patients could develop abnormal liver function, evidenced by reduced albumin and increased levels of aspartate aminotransferase (AST) and AST/alanine aminotransferase (ALT). T. marneffei-infected mice exhibited similar characteristics. In vitro investigations showed that T.marneffei induced the death of AML-12 cells. Furthermore, we determined that T.marneffei infection induced pyroptosis in hepatocytes of C57BL/6J mice and AML-12 cells, demonstrated by the increase of AIM2, caspase-1/-4, Gasdermin D(GSDMD) and pyroptosis-related cytokines in T.marneffei-infected mice/cells. Importantly, cell death was markedly suppressed in the presence of VX765 (an inhibitor of caspase-1/-4). Furthermore, in the presence of VX765, T.marneffei-induced pyroptosis was blocked. Nevertheless, necroptosis and apoptosis were also detected in infected animal model at 14 days post-infection. In conclusion, T.marneffei induces pyroptosis in hepatocytes through activation of the AIM2-caspase-1/-4-GSDMD axis, which may be an important cause of liver damage, and other death pathways including necroptosis and apoptosis may also be involved in the later stage of infection.

Foam Cells in Atherosclerosis: Novel Insights Into Its Origins, Consequences, and Molecular Mechanisms

Foam cells play a vital role in the initiation and development of atherosclerosis. This review aims to summarize the novel insights into the origins, consequences, and molecular mechanisms of foam cells in atherosclerotic plaques. Foam cells are originated from monocytes as well as from vascular smooth muscle cells (VSMC), stem/progenitor cells, and endothelium cells. Novel technologies including lineage tracing and single-cell RNA sequencing (scRNA-seq) have revolutionized our understanding of subtypes of monocyte- and VSMC-derived foam cells. By using scRNA-seq, three main clusters including resident-like, inflammatory, and triggering receptor expressed on myeloid cells-2 (Trem2 ^hi ) are identified as the major subtypes of monocyte-derived foam cells in atherosclerotic plaques. Foam cells undergo diverse pathways of programmed cell death including apoptosis, autophagy, necroptosis, and pyroptosis, contributing to the necrotic cores of atherosclerotic plaques. The formation of foam cells is affected by cholesterol uptake, efflux, and esterification. Novel mechanisms including nuclear receptors, non-coding RNAs, and gut microbiota have been discovered and investigated. Although the heterogeneity of monocytes and the complexity of non-coding RNAs make obstacles for targeting foam cells, further in-depth research and therapeutic exploration are needed for the better management of atherosclerosis.