Cholesterol Efflux Pathways Suppress Inflammasome Activation, NETosis, and Atherogenesis

MicroRNA-9-3p inhibits endothelial pyroptosis in atherosclerosis by targeting the PTEN/AKT axis

Inflammation and pyroptosis are key characteristic features of Atherosclerosis (AS), a complex, multifaceted chronic vascular disease. Although microRNAs (miRNAs) have been substantially implicated, as pivotal post-transcriptional regulators, in molecular mechanisms underlying atherosclerotic development, the precise role of miR-9-3p in atherosclerotic progression remains unclear. Herein, we aimed to elucidate the regulatory function of miR-9-3p in Endothelial Cell pyroptosis and AS via integrated bioinformatics analysis, as well as in vitro and in vivo assays. We focused on identifying signaling pathways miR-9-3p modulated and assessing its potential to mitigate atherosclerotic plaque formation. According to the results, miR-9-3p promoted AKT phosphorylation by directly targeting the 3'-Untranslated Region (3'-UTR) of PTEN mRNA, suppressing EC pyroptosis. Notably, the AKT signaling pathway, which was significantly enriched in our analyses, functions upstream of the NLRP3 inflammasome, a principal mediator of pyroptosis. We also identified the SP1 Transcription Factor (TF) binding sites within the promoter region of MIR9-1HG, implying a regulatory mechanism in which SP1 modulates miR-9-3p expression and function. Given the reversibility of epigenetic modifications, the potential of restoring miR-9-3p expression presents a novel therapeutic strategy for AS. Overall, in addition to advancing the understanding of atherosclerotic treatment mechanisms, this study positions miR-9-3p as a potential therapeutic target.

Targeting cholesterol-driven pyroptosis: a promising strategy for the prevention and treatment of atherosclerosis

Funding Pyroptosis is a type of programmed cell death (PCD) pathway distinguished by inflammation. It is activated by specific inflammasomes. Once activated, it causes the physical breakdown of the cell, along with the discharge of pro-inflammatory cytokines, such as interleukin-1β (IL-1β) and interleukin-18 (IL-18). Abundant evidence has demonstrated the existence of pyroptotic cell death within atherosclerotic plaques, which has significance for the development of atherosclerosis (AS). As a result, pyroptosis has become a new and important topic in cardiovascular disease (CVD) research. Cholesterol, it is recognized to have a connection with inflammation, exerts a crucial function in the development process of AS, and has been linked to the initiation of pyroptosis. This review aims to briefly summarize the fundamental aspects of pyroptosis and the influence of cholesterol-related inflammation in AS. Additionally, this review will explore potential therapeutic approaches based on pyroptosis that could be utilized for the prevention and treatment of AS.

Postoperative Stress Accelerates Atherosclerosis through Inflammatory Remodeling of the HDL Proteome and Impaired Reverse Cholesterol Transport

BACKGROUND

Over 10 million patients undergoing non-cardiac surgery annually experience major cardiovascular complications within 30 days, many due to destabilized atherosclerotic plaques. Reverse cholesterol transport (RCT), a key pathway for cholesterol removal by HDL and apoA-I, is critical in preventing plaque progression. While surgery-induced inflammation is known to impair HDL function, its effects on RCT and plaque stability remain unclear.

METHODS

To isolate the impact of surgical inflammation, independent of blood loss, we developed an abdominal laparotomy model in apoE -/- mice on a Western diet, minimizing blood loss and avoiding perioperative blood sampling. We assessed plasma cholesterol efflux capacity, performed proteomic analysis of HDL, and analyzed atherosclerotic plaques for lipid content, perilipin-2 (PLIN2), cleaved-caspase-3 (c-Casp-3), and necrotic core expansion. A novel dual-label, dual-cell-type in vivo RCT model was developed to compare RCT from macrophage-derived (BMDMs) and vascular smooth muscle cells (VSMCs)-derived foam cells. Recombinant apoA-I (rApoA-I) was tested for therapeutic rescue of impaired RCT.

RESULTS

Surgery significantly reduced RCT for at least 48 hours, paralleled by a drop in cholesterol efflux capacity and inflammatory remodeling of HDL, marked by elevated serum amyloid A (SAA1/2) and reduced apoA-I. Plaques showed a 1.6-fold increase in intracellular lipids and PLIN2 expression at 24 hours post-surgery, with elevated c-Casp-3 indicating lipid-driven apoptosis. Foam cell analysis revealed increased PLIN2 in both CD45 + (leukocyte) and CD45 - (non-leukocyte) subtypes, with leukocyte foam cells expressing higher PLIN2. c-Casp-3 + apoptotic cells were predominantly PLIN2 high and of both leukocytic and non-leukocytic origin. By day 15, the necrotic core area increased by 1.5-fold with sustained loss of plaque cellularity. Using our dual-cell-type RCT model, we found that surgery significantly impaired BMDM RCT in vivo , while VSMC RCT remained largely unaffected, highlighting foam cell subtype-specific vulnerability to surgical inflammation. These findings were mirrored in general surgery patients, whose postoperative plasma exhibited markedly reduced cholesterol efflux capacity. In mice, rApoA-I treatment partially restored RCT and reduced plaque lipid accumulation.

CONCLUSIONS

Surgical inflammation acutely impairs HDL function and RCT, triggering lipid accumulation, foam cell apoptosis, and accelerated plaque destabilization independent of blood loss. Immediate restoration of apoA-I at the time of surgery, aiming to counteract the acute phase response, may offer a targeted strategy to reduce postoperative cardiovascular risk.

Inflammasome Activation and Neutrophil Extracellular Traps in Atherosclerosis

The deposition of cholesterol containing cholesterol crystals and the infiltration of immune cells are features of atherosclerosis. Although the role of cholesterol crystals in the progression of atherosclerosis have long remained unclear, recent studies have clarified the involvement of cholesterol crystals in inflammatory responses. Cholesterol crystals activate the NLRP3 inflammasome, a molecular complex involved in the innate immune system. Activation of NLRP3 inflammasomes in macrophages cause pyroptosis, which is accompanied by the release of inflammatory cytokines such as IL-1β and IL-1α. Furthermore, NLRP3 inflammasome activation drives neutrophil infiltration into atherosclerotic plaques. Cholesterol crystals trigger NETosis against infiltrated neutrophils, a form of cell death characterized by the formation of neutrophil extracellular traps (NETs), which, in turn, prime macrophages to enhance inflammasome-mediated inflammatory responses. Colchicine, an anti-inflammatory drug effective in cardiovascular disease, is expected to inhibit cholesterol crystal-induced NLRP3 inflammasome activation and neutrophil infiltration. In this review, we illustrate the reinforcing cycle of inflammation that is amplified by inflammasome activation and NETosis.

Dysregulation of cholesterol homeostasis in cancer pathogenesis

Cholesterol is a unique lipid for all mammalian cells, with important functions in membrane biogenesis and maintenance of proper membrane integrity and fluidity. Therefore, it plays an important role in cellular homeostasis. Dysregulation of cholesterol homeostasis is associated with various diseases in humans, including cardiovascular diseases, inflammatory diseases, neurodegenerative disorders, and cancers. In the tumor microenvironment, intrinsic and extrinsic cellular factors reprogram cholesterol metabolism and consequently promote tumorigenesis. Here, we summarize the current knowledge on molecular mechanisms and functional roles of cholesterol homeostasis and its dysregulation in regard to cancer pathogenesis. We also discuss the interplay of cholesterol metabolism and the ATP-binding cassette (ABC) proteins, highly conserved cellular transmembrane lipid transporters. An emerging role of lipid ABC transporters as potential prognostic tools for cancer progression and invasiveness is emphasized. Targeting both cholesterol metabolism and proteins associated with membrane cholesterol holds promise as a novel therapeutic strategy for cancer treatment.

Probiotic membrane vesicles ameliorate atherosclerotic plaques by promoting lipid efflux and polarization of foamy macrophages

Foamy macrophages are pivotal contributors to the development and progression of atherosclerotic plaques, posing a substantial threat to human health. Presently, there is no pharmaceutical intervention available to effectively eliminate foamy macrophages. In this study, we demonstrate that probiotic membrane vesicles (MVs) can induce atherosclerotic plaque regression by modulating foamy macrophages. MVs isolated from Lactobacillus rhamnosus exhibited a specific uptake by foamy macrophages. Near-infrared fluorescence (NIRF) imaging, aortic oil red O staining, and hematoxylin and eosin staining showed reductions in the plaque area following MVs treatment. Mechanistically, bioinformatics analysis provided insights into how MVs exert their effects, revealing that they promote lipid efflux and macrophage polarization. Notably, MVs treatment upregulated NR1H3, which in turn increased ABCA1 expression, facilitating lipid efflux from foamy macrophages. Moreover, MVs shifted macrophage polarization from a pro-inflammatory M1 phenotype to an anti-inflammatory M2 phenotype, highlighting their potential to create a more protective environment against plaque progression. This study is significant as it introduces MVs as a novel therapeutic platform for the targeted delivery of anti-inflammatory agents to atherosclerotic sites. By specifically modulating macrophage function, MVs hold considerable potential for the treatment of atherosclerosis and related cardiovascular diseases, addressing an unmet need in current therapeutic strategies.

Role for the liver X receptor agonist 22-ketositosterol in preventing disease progression in an Alzheimer's disease mouse model

BACKGROUND AND PURPOSE

Liver X receptors (LXRs) are promising therapeutic targets for alleviating Alzheimer's disease (AD) symptoms. We assessed the impact of the semi-synthetic LXR agonist 22-ketositosterol on disease progression in an AD mouse model.

EXPERIMENTAL APPROACH

From 5.5 months of age, APPswePS1ΔE9 (AD) mice and wild-type (WT) littermates received a regular or 22-ketositosterol-supplemented diet (0.017% w/w). Cognition was assessed with object location and recognition tasks and a spontaneous alternation Y-maze test. Amyloid β was quantified using immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA), microglia (Iba1, CD68) and astrocyte (GFAP) markers using IHC. Sterols were determined in food, serum, liver and cerebellum.

KEY RESULTS

22-Ketositosterol activated both liver X receptors-α and -β and promoted cholesterol efflux in cell cultures. Diet supplementation with 22-ketositosterol prevented a decline in the performance of APPswePS1ΔE9 mice in the object location task but not in the other two tasks. Without affecting amyloid β deposition, 22-ketositosterol decreased microglia (Iba1, CD68) and astrocyte (GFAP) markers in the cortex and hippocampus of APPswePS1ΔE9, suggesting potential anti-inflammatory effects. No lipid accumulation was detected in the liver or serum upon 22-ketositosterol supplementation.

CONCLUSIONS AND IMPLICATIONS

Diet supplementation with 22-ketositosterol prevented the decline in spatial memory of APPswePS1ΔE9 mice. Our data suggest therapeutic benefits of 22-ketositosterol possibly by enhancing cholesterol efflux and mitigating inflammatory responses, without inducing hepatosteatosis or hypertriglyceridemia.

Exploring the Roles of Liver X Receptors in Lipid Metabolism and Immunity in Atherosclerosis

Hypercholesterolemia causes atherosclerosis by inducing immune cell migration and chronic inflammation in arterial walls. Recent single-cell analyses reveal the presence of lipid-enriched foamy macrophages, as well as other macrophage subtypes, neutrophils, T cells, and B cells, in atherosclerotic plaques in both animal models and humans. These cells interact with each other and other cells, including non-immune cells such as endothelial cells and smooth muscle cells. They thereby regulate metabolic, inflammatory, phagocytic, and cell death processes, thus affecting the progression and stability of atherosclerotic plaques. The nuclear receptors liver X receptor (LXR)α and LXRβ are transcription factors that are activated by oxysterols and regulate lipid metabolism and immune responses. LXRs regulate cholesterol homeostasis by controlling cholesterol's transport, absorption, synthesis, and breakdown in the liver and intestine. LXRs are also highly expressed in tissue-resident and monocyte-derived macrophages and other immune cells, including both myeloid cells and lymphocytes, and they regulate both innate and adaptive immune responses. Interestingly, LXRs have immunosuppressive and immunoregulatory functions that are cell-type-dependent. In animal models of atherosclerosis, LXRs have been shown to be involved in both progression and regression phases. The pharmacological activation of LXR enhances cholesterol efflux from macrophages and promotes atherosclerosis progression. Deleting LXR in immune cells, especially myeloid cells, accelerates atherosclerosis by increasing monocyte migration, macrophage proliferation and activation, and neutrophil extracellular traps (NETs); furthermore, the deletion of hematopoietic LXRs impairs the regression of atherosclerotic plaques. Therefore, LXRs in immune cells may be a potent therapeutic target for atherosclerosis.

Global deletion of the LXR-regulated gene EEPD1 reveals macrophage-specific changes in lipid metabolism and cholesterol efflux

BACKGROUND AND AIMS

We recently reported that Endonuclease/Exonuclease/Phosphatase family Domain containing 1 (EEPD1) is a transcriptional target of the sterol-responsive nuclear Liver X Receptors (LXR) in macrophages. The aim of this study is to clarify the in vivo role of EEPD1 in whole-body and macrophage lipid handling, and in the development of atherosclerosis.

METHODS

We developed mice with global deletion of Eepd1 and challenged them with a high-fat- and a Western-type diet. Bone marrow-derived macrophages (BMDM) were used for profiling transcriptomic and lipidomic changes, and evaluating cholesterol efflux in the absence of Eepd1. We transplanted bone marrow from wildtype and Eepd1KO mice into LdlrKO recipients to assess the role of myeloid-specific EEPD1 in atherogenesis.

RESULTS

Eepd1KO mice were indistinguishable from wildtype controls when fed a low-fat diet. However, when challenged with a high-fat diet or a cholesterol-containing western diet, Eepd1KO displayed enhanced weight gain, with no evident changes in plasma and hepatic lipid levels observed. Consistent with our earlier report, BMDM isolated from Eepd1KO mice had attenuated LXR-stimulated cholesterol efflux to high density lipoprotein and Apolipoprotein A1 when compared to wildtype cells. The transcriptomic and lipidomic landscape of these cells revealed a small reduction in expression of cholesterol biosynthetic genes in LXR-stimulated Eepd1KO cells, and prominent changes in diacylglycerol and hexosylceramides level and species. Changes were also observed in triglyceride and cholesterol-ester species. Myeloid-specific loss of Eepd1 did not alter atherosclerotic plaque size and collagen content in bone marrow-transplanted LdlrKO recipients.

CONCLUSIONS

Loss of Eepd1 results in an altered lipidomic landscape and reduced LXR-stimulated cholesterol efflux in BMDM, but myeloid-specific loss of Eepd1 does not influence atherogenesis in mice.

Cholesterol metabolism: physiological versus pathological aspects in intracerebral hemorrhage

Cholesterol is an important component of plasma membranes and participates in many basic life functions, such as the maintenance of cell membrane stability, the synthesis of steroid hormones, and myelination. Cholesterol plays a key role in the establishment and maintenance of the central nervous system. The brain contains 20% of the whole body's cholesterol, 80% of which is located within myelin. A huge number of processes (e.g., the sterol regulatory element-binding protein pathway and liver X receptor pathway) participate in the regulation of cholesterol metabolism in the brain via mechanisms that include cholesterol biosynthesis, intracellular transport, and efflux. Certain brain injuries or diseases involving crosstalk among the processes above can affect normal cholesterol metabolism to induce detrimental consequences. Therefore, we hypothesized that cholesterol-related molecules and pathways can serve as therapeutic targets for central nervous system diseases. Intracerebral hemorrhage is the most severe hemorrhagic stroke subtype, with high mortality and morbidity. Historical cholesterol levels are associated with the risk of intracerebral hemorrhage. Moreover, secondary pathological changes after intracerebral hemorrhage are associated with cholesterol metabolism dysregulation, such as neuroinflammation, demyelination, and multiple types of programmed cell death. Intracellular cholesterol accumulation in the brain has been found after intracerebral hemorrhage. In this paper, we review normal cholesterol metabolism in the central nervous system, the mechanisms known to participate in the disturbance of cholesterol metabolism after intracerebral hemorrhage, and the links between cholesterol metabolism and cell death. We also review several possible and constructive therapeutic targets identified based on cholesterol metabolism to provide cholesterol-based perspectives and a reference for those interested in the treatment of intracerebral hemorrhage.

The Role of Neutrophil Extracellular Traps in Atherosclerosis: From the Molecular to the Clinical Level

Atherosclerosis is a chronic inflammatory condition that is typified by the deposition of lipids and the subsequent inflammation of medium and large arteries. Neutrophil extracellular traps (NETs) are fibrous meshworks of DNA, histones, and granzymes expelled by activated neutrophils in response to a variety of pathogenic conditions. In addition to their role in pathogen eradication, NETs have been demonstrated to play a pivotal role in the development of atherosclerosis. This article presents a review of the bidirectional interactions in which atherosclerosis-related risk factors stimulate the formation of NETs, which in turn support disease progression. This article emphasizes the involvement of NETs in the various stages of atherogenesis and development, influencing multiple factors such as the vascular endothelium, platelets, the inflammatory milieu, and lipid metabolism. The findings of this study offer new insights and avenues for further investigation into the processes underlying the formation and regulation of the vascular inflammatory microenvironment in atherosclerosis. Finally, potential targeted therapeutic strategies for NETs are discussed to facilitate their progression to clinical practice (Graphical Abstract).

Hypercholesterolemia-induced LXR signaling in smooth muscle cells contributes to vascular lesion remodeling and visceral function

Vascular smooth muscle cells (VSMC) are the most abundant cell type in the artery's media layer and regulate vascular tone and lesion remodeling during atherogenesis. Like monocyte-derived macrophages, VSMCs accumulate excess lipids and contribute to the total intimal foam cell population in human coronary plaques and mouse aortic atheroma. While there are extensive studies characterizing the contribution of lipid metabolism in macrophage immunometabolic responses in atherosclerotic plaques, the role of VSMC lipid metabolism in regulating vascular function and lesion remodeling in vivo remains poorly understood. Here, we report that the liver X receptor (LXR) signaling pathway in VSMC is continuously activated during atherogenesis. Notably, we found that LXR deficiency in SMCs under hypercholesterolemic conditions influenced lesion remodeling by altering the fate of dedifferentiated SMCs and promoting the accumulation of VSMC-derived transitional cells. This phenotypic switching was accompanied by reduced indices of plaque stability, characterized by a larger necrotic core area and reduced fibrous cap thickness. Moreover, SMC-specific LXR deficiency impaired vascular function and caused visceral myopathy characterized by maladaptive bladder remodeling and gut lipid malabsorption. Mechanistically, we found that the expression of several genes involved in cholesterol efflux and FA synthesis including Abca1, Srebf1, Scd1, Scd2, Acsl3, and Mid1ip1 was downregulated in mice lacking LXRαβ in SMCs, likely contributing to the phenotypic switching of VSMC in the atherosclerotic lesions.

Serum Lipids, Inflammation, and the Risk of Atrial Fibrillation: Pathophysiological Links and Clinical Evidence

Dyslipidemia is a metabolic disorder characterized by quantitative and/or qualitative abnormalities in serum lipid levels. Elevated serum cholesterol levels can modify the turnover and recruitment of ionic channels in myocytes and cellular homeostasis, including those of inflammatory cells. Experimental and clinical data indicate that inflammation is implicated in the pathophysiology of atrial remodeling, which is the substrate of atrial fibrillation (AF). Data about the association between increased lipid serum levels and AF are few and contrasting. Lipoprotein (a), adiposity, and inflammation seem to be the main drivers of AF; in contrast, low-density lipoproteins, high-density lipoproteins and triglycerides are not directly involved in AF onset. The present review aimed to describe the pathophysiological link between dyslipidemia and AF, the efficacy of lipid-lowering therapies in atherosclerotic cardiovascular disease (ASCVD) patients with and without AF, and the impact of lipid-lowering therapies on AF incidence.

The various roles of TREM2 in cardiovascular disease

Triggering receptor expressed on myeloid cells-2 (TREM2) is a transmembrane immune receptor that is expressed mainly on macrophages. As a pathology-induced immune signaling hub, TREM2 senses tissue damage and activates immune remodeling in response. Previous studies have predominantly focused on the TREM2 signaling pathway in Alzheimer's disease, metabolic syndrome, and cancer. Recent research has indicated that TREM2 signaling is also activated in various cardiovascular diseases. In this review, we summarize the current understanding and the unanswered questions regarding the role of TREM2 signaling in mediating the metabolism and function of macrophages in atherosclerosis and various models of heart failure. In the context of atherosclerosis, TREM2 signaling promotes foam cell formation and is crucial for maintaining macrophage survival and plaque stability through efferocytosis and cholesterol efflux. Recent studies on myocardial infarction, sepsis-induced cardiomyopathy, and hypertensive heart failure also implicated the protective role of TREM2 signaling in cardiac macrophages through efferocytosis and paracrine functions. Additionally, we discuss the clinical significance of elevated soluble TREM2 (sTREM2) in cardiovascular disease and propose potential therapies targeting TREM2. The overall aim of this review is to highlight the various roles of TREM2 in cardiovascular diseases and to provide a framework for therapeutic strategies targeting TREM2.

NLRP3 inflammasome in cardiovascular diseases: an update

Cardiovascular disease (CVD) continues to be the leading cause of mortality worldwide. The nucleotide oligomerization domain-, leucine-rich repeat-, and pyrin domain-containing protein 3 (NLRP3) inflammasome is involved in numerous types of CVD. As part of innate immunity, the NLRP3 inflammasome plays a vital role, requiring priming and activation signals to trigger inflammation. The NLRP3 inflammasome leads both to the release of IL-1 family cytokines and to a distinct form of programmed cell death called pyroptosis. Inflammation related to CVD has been extensively investigated in relation to the NLRP3 inflammasome. In this review, we describe the pathways triggering NLRP3 priming and activation and discuss its pathogenic effects on CVD. This study also provides an overview of potential therapeutic approaches targeting the NLRP3 inflammasome.

Cell membrane biomimetic magnetic fluorescent bifunctional nanoplatform for drug lead discovery

BACKGROUD

Biomimetic nanoplatforms based on membrane coating strategies have received increasing attention in the field of medical research. However, it cannot perform biomedical imaging screening, which is essential for real-time identification. As a rich source of new drug discovery, traditional Chinese medicine (TCM) has made important contributions to the treatment of many diseases.

RESULLT

Therefore, a magnetic fluorescent bifunctional nanomaterial was developed for screening the active ingredients in Fuzi. The magnetic fluorescence nanoparticles Fe3O4@GO@RhB synthesized by one-step synthesis showed low toxicity, excellent fluorescence properties and fast magnetic separation. After coating the magnetic nanoparticle with cell membrane, the screening procedure was optimized with positive drug verapamil hydrochloride. Under the optimal conditions, the active ingredients in aconite were screened, and the three active ingredients were identified as benzoyl-mesaconine, benzoyl-aconine and benzoyl-hypacoitine by UPLC-MS/MS. In addition, in situ imaging technique was used to further verify the proliferative activity of the screened active ingredients.

SIGNIFICANCE

The magnetic fluorescence bifunctional nanoplatform for cell membrane bionic screening combined with in situ imaging technology established in this paper not only can rapidly and effectively target screening and separation of active ingredients in TCM, but also provides a new platform for bioimaging screening.

Regulated cell death in acute myocardial infarction: Molecular mechanisms and therapeutic implications

Acute myocardial infarction (AMI), primarily caused by coronary atherosclerosis, initiates a series of events that culminate in the obstruction of coronary arteries, resulting in severe myocardial ischemia and hypoxia. The subsequent myocardial ischemia/reperfusion (I/R) injury further aggravates cardiac damage, leading to a decline in heart function and the risk of life-threatening complications. The complex interplay of multiple regulated cell death (RCD) pathways plays a pivotal role in the pathogenesis of AMI. Each RCD pathway is orchestrated by a symphony of molecular regulatory mechanisms, highlighting the dynamic changes and critical roles of key effector molecules. Strategic disruption or inhibition of these molecular targets offers a tantalizing prospect for mitigating or even averting the onset of RCD, thereby limiting the extensive loss of cardiomyocytes and the progression of detrimental myocardial fibrosis. This review systematically summarizes the mechanisms underlying various forms of RCD, provides an in-depth exploration of the pathogenesis of AMI through the lens of RCD, and highlights a range of promising therapeutic targets that hold the potential to revolutionize the management of AMI.

The association between neutrophil to high-density lipoprotein cholesterol ratio and gallstones: a cross-sectional study

OBJECTIVE

Several studies have discussed the relationship between cholesterol and gallstones, and high-density lipoprotein cholesterol (HDL-C) as a representative of this has been addressed in various diseases. The metric neutrophil to high-density lipoprotein cholesterol ratio (NHR) derived from HDL-C has attracted much attention. The purpose of this article is to examine the relationship between NHR and gallstones in a population of American adults.

METHODS

This study investigated the correlation between NHR and gallstone prevalence among US adults using population-based data from the 2017-2020 National Health and Nutrition Examination Survey (NHANES). NHR was derived by dividing the neutrophil count by HDL-C. Data were analyzed using a variety of statistical techniques, such as univariate analysis, multivariate analysis, and subgroup analysis. In addition, a receiver operating characteristic curve (ROC) was used to determine the predictive power of the index for the risk of gallstone prevalence.

RESULTS

The trial enrolled 6,954 subjects, among whom 746 patients were diagnosed with gallstones. By fully adjusted multivariate logistic regression analysis in the Model 3 section observed a significant positive association between NHR and gallstones with an odds ratio (OR) of 1.05 and a 95% confidence interval (CI) of (1.01, 1.10). The restricted cubic curve (RCS) had a P-Nonlinear = 0.481, suggesting that the relationship was a near-linear one. The area under the curve (AUC) of the ROC curve was 0.550, indicating that NHR has a predictive value for the development of gallstones.

CONCLUSION

This study demonstrated a near-linear correlation between NHR and increased susceptibility to gallstones, and the ROC curve is evidence that NHR has some predictive value for the risk of gallstones, albeit with weak predictive power relative to NPAR (Neutrophil percentage/albumin) and NAR (Neutrophils/albumin). Of course, to confirm these findings, more extensive prospective studies are needed to thoroughly validate the role of NHR in the development of gallstones.

Role of Neutrophil Extracellular Traps in Hypertension and Their Impact on Target Organs

Hypertension is the predominant cause of cardiovascular diseases (CVDs) globally, and essential hypertension (EH) represents a significant public health challenge due to its multifactorial etiology involving complex interactions between genetic and environmental factors. However, the pathogenesis of EH is still unclear. Hypertension is a dysregulation in the renin-angiotensin-aldosterone system and sympathetic nervous system, both regulating saline homeostasis and cardiovascular function. However, current therapeutic interventions targeting these systems have limited efficacy in approximately 40% of cases, suggesting the involvement of alternative mechanisms. Inflammation is associated with the occurrence and progression of hypertension, but the underlying mechanism remains elusive, while chronic inflammation leads to tissue damage, fibrosis, and irreversible organ dysfunction. The development and maintenance of EH are caused by endothelial dysfunction, oxidative stress, and chronic inflammation. Neutrophils are involved in both acute and chronic inflammation since they represent the primary line of defense against inflammatory insults once recruited to the inflamed site where they remove harmful impurities. The process involving the formation of neutrophil extracellular traps (NETs) is called NETosis are involved in the pathogenesis and progression of CVDs, including coronary artery disease, acute myocardial infarction, peripheral arterial disease, heart failure, and atrial fibrillation. Recent investigations demonstrated that NETs facilitate the development of hypertension; however, the precise role of NETs in hypertension remains largely elusive. Therefore, this review aims to provide an overview of the current understanding regarding the involvement of NETosis in hypertension and explore the potential therapies targeting NETs for future interventions.

Exploring novel markers for coronary heart disease associated with systemic lupus erythematosus: A review

Systemic lupus erythematosus (SLE) is an autoimmune condition that is characterized by the production of autoantibodies and sustained inflammatory damage. Coronary heart disease (CHD) is a common complication of SLE, significantly increases CHD-related mortality in SLE patients. Despite conventional risk factors, the mechanisms contributing to a higher CHD risk require further investigation, with the immune and inflammatory aspects of SLE playing a significant role. Endothelial cell damage and dysfunction are key factors in the progression of coronary atherosclerosis in SLE patients. This review specifically focuses on endothelial dysfunction and the role of specific microRNAs in the context of SLE and CHD. In addition, we discuss the effects and functions of oxidative stress markers, endothelial progenitor cells, and circulating endothelial cells in individuals with both SLE and CHD. We also explored the typical inflammatory markers associated with SLE and CHD, addressing their clinical significance and limitations.

Metabolism: a potential regulator of neutrophil fate

Neutrophils are essential components of the innate immune system that defend against the invading pathogens, such as bacteria, viruses, and fungi, as well as having regulatory roles in various conditions, including tissue repair, cancer immunity, and inflammation modulation. The function of neutrophils is strongly related to their mode of cell death, as different types of cell death involve various cellular and molecular alterations. Apoptosis, a non-inflammatory and programmed type of cell death, is the most common in neutrophils, while other modes of cell death, including NETOsis, necrosis, necroptosis, autophagy, pyroptosis, and ferroptosis, have specific roles in neutrophil function regulation. Immunometabolism refers to energy and substance metabolism in immune cells, and profoundly influences immune cell fate and immune system function. Intercellular and intracellular signal transduction modulate neutrophil metabolism, which can, in turn, alter their activities by influencing various cell signaling pathways. In this review, we compile an extensive body of evidence demonstrating the role of neutrophil metabolism in their various forms of cell death. The review highlights the intricate metabolic characteristics of neutrophils and their interplay with various types of cell death.

ABCA1-Super Enhancer RNA Promotes Cholesterol Efflux, Reduces Macrophage-Mediated Inflammation and Atherosclerosis

We describe a previously uncharacterized ATP-binding cassette A1 super enhancer RNA (ABCA1-seRNA)-mediated cholesterol efflux. In addition, it promoted macrophage inflammatory cytokine release, and was causally correlated with coronary artery disease severity. Mechanistically, ABCA1-seRNA upregulated cholesterol efflux by interacting with mediator complex subunit 23 and recruiting retinoid X receptor-alpha and liver X receptor-alpha to promote ABCA1 transcription in a cis manner. Meanwhile, ABCA1-seRNA induced P65 ubiquitination degradation, and thereby repressed the macrophage inflammatory response. Consistently, overexpression of ABCA1-seRNA in ApoE-/- mice decreased plasma lipids, cytokines, and atherosclerotic plaques. These findings indicate ABCA1-seRNA is a critical epigenetic regulator that maintains cholesterol homeostasis and modulates inflammation, thus promising a therapeutic target for atherosclerotic cardiovascular diseases.

Qinghao-Biejia Herb Pair attenuates SLE atherosclerosis by regulating macrophage polarization via ABCA1/G1-mediated cholesterol efflux

ETHNOPHARMACOLOGICAL RELEVANCE

Qinghao-Biejia herb pair (QB) is the core herb pair of "Jieduquyuziyin prescription" and is one of the commonly used herb pairs for the clinical treatment of systemic lupus erythematosus (SLE). Previous studies have shown that QB reduces the expression of inflammatory cytokines like IL-6 and TNF-α in the serum and kidney of MRL/lpr mice. Additionally, it inhibits the expression of TLR4 and MyD88 in the kidney and aorta and reduces the deposition of renal complement C3 and aortic plaque after treatment. These findings suggest that QB has a preventive and therapeutic effect on lupus rats.

AIM OF THE STUDY

This study sought to investigate the mechanisms underlying the anti-SLE combined with atherosclerosis activity of the Qinghao-Biejia herb pair.

MATERIALS AND METHODS

Drug targets for QB were identified using the HERB database, while targets associated with SLE and atherosclerosis were retrieved from the GeneCards database. The intersection of these drug and disease targets was then analyzed using a protein-protein interaction (PPI) network with GO and KEGG pathway enrichment analysis. In vivo, apolipoprotein E-deficient (ApoE-/-) mice were induced to develop SLE-AS by intraperitoneal injection of pristane and continued feeding of a high-fat diet. The changes in relevant indexes were observed after 12 weeks of gavage treatment with hydroxychloroquine, QB, Q (Qinghao alone), and B (Biejia alone). Bone marrow-derived macrophages from ApoE-/- mice and Raw 264.7 macrophages were used to explore the mechanisms of QB treatment.

RESULTS

The levels of inflammatory cytokines in serum and pathological liver changes in mice were improved to varying degrees in the treatment groups. Additionally, there was a reduction in aortic atheromatous plaque formation and some improvement in cholesterol efflux. Furthermore, QB suppressed the expression of inflammatory cytokines in M1 macrophages, suggesting a role in regulating macrophage polarization.

CONCLUSION

QB demonstrates clear efficacy for treating SLE-AS, and its therapeutic mechanism may involve the regulation of macrophage phenotypes by promoting cholesterol efflux.

Colchicine prevents accelerated atherosclerosis in TET2-mutant clonal haematopoiesis

BACKGROUND AND AIMS

Somatic mutations in the TET2 gene that lead to clonal haematopoiesis (CH) are associated with accelerated atherosclerosis development in mice and a higher risk of atherosclerotic disease in humans. Mechanistically, these observations have been linked to exacerbated vascular inflammation. This study aimed to evaluate whether colchicine, a widely available and inexpensive anti-inflammatory drug, prevents the accelerated atherosclerosis associated with TET2-mutant CH.

METHODS

In mice, TET2-mutant CH was modelled using bone marrow transplantations in atherosclerosis-prone Ldlr-/- mice. Haematopoietic chimeras carrying initially 10% Tet2-/- haematopoietic cells were fed a high-cholesterol diet and treated with colchicine or placebo. In humans, whole-exome sequencing data and clinical data from 37 181 participants in the Mass General Brigham Biobank and 437 236 participants in the UK Biobank were analysed to examine the potential modifying effect of colchicine prescription on the relationship between CH and myocardial infarction.

RESULTS

Colchicine prevented accelerated atherosclerosis development in the mouse model of TET2-mutant CH, in parallel with suppression of interleukin-1β overproduction in conditions of TET2 loss of function. In humans, patients who were prescribed colchicine had attenuated associations between TET2 mutations and myocardial infarction. This interaction was not observed for other mutated genes.

CONCLUSIONS

These results highlight the potential value of colchicine to mitigate the higher cardiovascular risk of carriers of somatic TET2 mutations in blood cells. These observations set the basis for the development of clinical trials that evaluate the efficacy of precision medicine approaches tailored to the effects of specific mutations linked to CH.

Inflammatory crosstalk impairs phagocytic receptors and aggravates atherosclerosis in clonal hematopoiesis in mice

Clonal hematopoiesis (CH) increases inflammasome-linked atherosclerosis, but the mechanisms by which CH mutant cells transmit inflammatory signals to nonmutant cells are largely unknown. To address this question, we transplanted 1.5% Jak2V617F (Jak2VF) bone marrow (BM) cells with 98.5% WT BM cells into hyperlipidemic Ldlr-/- mice. Low-allele-burden (LAB) mice showed accelerated atherosclerosis with increased features of plaque instability, decreased levels of the macrophage phagocytic receptors c-Mer tyrosine kinase (MERTK) and triggering receptor expressed on myeloid cells 2 (TREM2), and increased neutrophil extracellular traps (NETs). These changes were reversed when Jak2VF BM was transplanted with Il1r1-/- BM. LAB mice with noncleavable MERTK in WT BM showed improvements in necrotic core and fibrous cap formation and reduced NETs. An agonistic TREM2 antibody (4D9) markedly increased fibrous caps in both control and LAB mice, eliminating the difference between the groups. Mechanistically, 4D9 increased TREM2+PDGFB+ macrophages and PDGF receptor-α+ fibroblast-like cells in the cap region. TREM2 and PDGFB mRNA levels were positively correlated in human carotid plaques and coexpressed in macrophages. In summary, low frequencies of Jak2VF mutations promoted atherosclerosis via IL-1 signaling from Jak2VF to WT macrophages and neutrophils, promoting cleavage of phagocytic receptors and features of plaque instability. Therapeutic approaches that stabilize MERTK or TREM2 could promote plaque stabilization, especially in CH- and inflammasome-driven atherosclerosis.

Defective biological activities of high-density lipoprotein identify patients at highest risk of recurrent cardiovascular event

AIMS

Low cholesterol efflux capacity and elevated levels of Interleukin-1ß (IL-1ß) are both associated with residual cardiovascular risk in patients with acute myocardial infarction (MI) and may be used as new biomarkers to identify patients at higher cardiovascular risk.

METHODS

We evaluated potential synergetic effect of cholesterol efflux capacity and IL-1ß on recurrent major adverse cardiovascular events (MACE) at one-year in 2012 patients with acute ST- segment elevation MI who underwent primary percutaneous coronary intervention. In addition, we evaluated the contribution to residual risk of HDL biological functions from 20 patients of the two extreme subgroups, focusing on cholesterol efflux capacity and anti-inflammatory properties.

RESULTS

Patients with MACE during the first year after the MI had significantly lower serum cholesterol efflux capacity as compared to those without recurrent events and higher level of IL-1ß, both associations were confirmed after multivariate analysis. We found an inverse relationship between CEC and circulating levels of the inflammatory markers IL-1ß, defining a very high risk (Low CEC/High IL-1ß) and a low risk (High CEC/Low IL-1ß) group of patients. Patients combining Low CEC/High IL-1ß exhibited the highest risk of recurrent MACE at one year showing an additive prognostic value of these biomarkers, regardless of all the other clinical or biological factors. In this very high-risk subgroup, patients exhibited reduced HDL-efflux capacity and defective ABCA1 and SR-BI with enhanced pro-inflammatory activity as a potential explanation for our clinical findings.

CONCLUSION

Impaired cholesterol efflux capacity and elevated IL-1β synergistically increase the residual cardiovascular risk in MI patients, which could be explained by reduced HDL-efflux capacity and enhanced HDL pro-inflammatory activity.

The Anti-Inflammatory Effect of Lactococcus lactis-Ling-Zhi 8 on Ameliorating Atherosclerosis and Nonalcoholic Fatty Liver in High-Fat Diet Rabbits

Inflammation plays a crucial role in atherosclerosis and nonalcoholic fatty liver disease (NAFLD). We previously engineered a recombinant Lactococcus lactis strain expressing the Ling-Zhi immunomodulatory protein (L. lactis-LZ8). This study investigated the anti-atherosclerotic effects of L. lactis-LZ8 in rabbits fed a high-fat diet (HFD). Changes in body weight, serum lipid profiles, and liver function were monitored. The aorta and liver tissues were analyzed for gross pathology and histopathology. Eight-week administration of L. lactis-LZ8 with HFD ameliorated atherosclerosis by downregulating protein and gene expression associated with lipid metabolism and inflammation in the aortas. The rabbits receiving L. lactis-LZ8 exhibited a significant dose-dependent reduction in hepatic fat accumulation. RNA sequencing of the livers revealed that inflammatory genes in the L. lactis-LZ8 groups were downregulated compared to the HFD group. Disease ontology enrichment analysis indicated that these genes were involved in atherosclerosis. Gene set enrichment analysis plots revealed significant enrichment in the gene sets related to cholesterol homeostasis. CIBERSORT immune cell fraction analysis indicated significant infiltration by regulatory T cells, CD8+ T cells, activated dendritic cells, and natural killer cells in the L. lactis-LZ8 group. Our studies underscore LZ8's role in precision nutrition, providing a potential solution to the current challenges in modifying atherosclerosis and NAFLD.

Role of Gut Microbial Metabolites in Cardiovascular Diseases-Current Insights and the Road Ahead

Cardiovascular diseases (CVDs) are the leading cause of premature morbidity and mortality globally. The identification of novel risk factors contributing to CVD onset and progression has enabled an improved understanding of CVD pathophysiology. In addition to the conventional risk factors like high blood pressure, diabetes, obesity and smoking, the role of gut microbiome and intestinal microbe-derived metabolites in maintaining cardiovascular health has gained recent attention in the field of CVD pathophysiology. The human gastrointestinal tract caters to a highly diverse spectrum of microbes recognized as the gut microbiota, which are central to several physiologically significant cascades such as metabolism, nutrient absorption, and energy balance. The manipulation of the gut microbial subtleties potentially contributes to CVD, inflammation, neurodegeneration, obesity, and diabetic onset. The existing paradigm of studies suggests that the disruption of the gut microbial dynamics contributes towards CVD incidence. However, the exact mechanistic understanding of such a correlation from a signaling perspective remains elusive. This review has focused upon an in-depth characterization of gut microbial metabolites and their role in varied pathophysiological conditions, and highlights the potential molecular and signaling mechanisms governing the gut microbial metabolites in CVDs. In addition, it summarizes the existing courses of therapy in modulating the gut microbiome and its metabolites, limitations and scientific gaps in our current understanding, as well as future directions of studies involving the modulation of the gut microbiome and its metabolites, which can be undertaken to develop CVD-associated treatment options. Clarity in the understanding of the molecular interaction(s) and associations governing the gut microbiome and CVD shall potentially enable the development of novel druggable targets to ameliorate CVD in the years to come.

Genetic and epigenetic regulation of inflammasomes: Role in atherosclerosis

The cardiovascular complications of atherosclerosis are thought to arise from an inflammatory response to the accumulation of cholesterol-rich lipoproteins in the arterial wall. The positive outcome of CANTOS (Canakinumab Anti-inflammatory Thrombosis Outcome Study) provided key evidence to support this concept and suggested that inflammasomes and IL-1β are important inflammatory mediators in human atherosclerotic cardiovascular diseases (ACVD). In specific settings NLRP3 or AIM2 inflammasomes can induce inflammatory responses in the arterial wall and promote the formation of unstable atherosclerotic plaques. Clonal hematopoiesis (CH) has recently emerged as a major independent risk factor for ACVD. CH mutations arise during ageing and commonly involves variants in genes mediating epigenetic modifications (TET2, DNMT3A, ASXL1) or cytokine signaling (JAK2). Accumulating evidence points to the role of inflammasomes in the progression of CH-induced ACVD events and has shed light on the regulatory pathways and possible therapeutic approaches that specifically target inflammasomes in atherosclerosis. Epigenetic dynamics play a vital role in regulating the generation and activation of inflammasome components by causing changes in DNA methylation patterns and chromatin assembly. This review examines the genetic and epigenetic regulation of inflammasomes, the intersection of macrophage cholesterol accumulation with inflammasome activation and their roles in atherosclerosis. Understanding the involvement of inflammasomes in atherosclerosis pathogenesis may lead to customized treatments that reduce the burden of ACVD.

Bridging the Gap Between the Bench and Bedside: Clinical Applications of High-density Lipoprotein Function

Decades of research have reshaped our understanding of high-density lipoprotein (HDL) , shifting our focus from cholesterol (C) levels to multifaceted functionalities. Epidemiological studies initially suggested an association between HDL-C levels and cardiovascular disease (CVD) risk; however, such a simple association has not been indicated by recent studies. Notably, genome-wide studies have highlighted discrepancies between HDL-C levels and CVD outcomes, urging a deeper exploration of the role of HDL. The key to this shift lies in elucidating the role of HDL in reverse cholesterol transport (RCT), which is a fundamental anti-atherosclerotic mechanism. Understanding RCT has led to the identification of therapeutic targets and novel interventions for atherosclerosis. However, clinical trials have underscored the limitations of HDL-C as a therapeutic target, prompting the re-evaluation of the role of HDL in disease prevention. Further investigations have revealed the involvement of HDL composition in various diseases other than CVD, including chronic kidney disease, Alzheimer's disease, and autoimmune diseases. The anti-inflammatory, antioxidative, and anti-infectious properties of HDL have emerged as crucial aspects of its protective function, opening new avenues for novel biomarkers and therapeutic targets. Omics technologies have provided insights into the diverse composition of HDL, revealing disease-specific alterations in the HDL proteome and lipidome. In addition, combining cell-based and cell-free assays has facilitated the evaluation of the HDL functionality across diverse populations, offering the potential for personalized medicine. Overall, a comprehensive understanding of HDL multifunctionality leads to promising prospects for future clinical applications and therapeutic developments, extending beyond cardiovascular health.

Sodium Acetate Enhances Neutrophil Extracellular Trap Formation via Histone Acetylation Pathway in Neutrophil-like HL-60 Cells

Neutrophil extracellular trap formation has been identified as a new cell death mediator, termed NETosis, which is distinct from apoptosis and necrosis. NETs capture foreign substances, such as bacteria, by releasing DNA into the extracellular environment, and have been associated with inflammatory diseases and altered immune responses. Short-chain fatty acids, such as acetate, are produced by the gut microbiota and reportedly enhance innate immune responses; however, the underlying molecular mechanisms remain unclear. Here, we investigated the effects of sodium acetate, which has the highest SCFA concentration in the blood and gastrointestinal tract, on NETosis by focusing on the mechanisms associated with histone acetylation in neutrophil-like HL-60 cells. Sodium acetate enhanced NETosis, as shown by fluorescence staining with SYTOX green, and the effect was directly proportional to the treatment duration (16-24 h). Moreover, the addition of sodium acetate significantly enhanced the acetylation of Ace-H3, H3K9ace, and H3K14ace. Sodium acetate-induced histone acetylation rapidly decreased upon stimulation with the calcium ionophore A23187, whereas histone citrullination markedly increased. These results demonstrate that sodium acetate induces NETosis via histone acetylation in neutrophil-like HL-60 cells, providing new insights into the therapeutic effects based on the innate immunity-enhancing effect of dietary fiber.

Region-Specific CD16+ Neutrophils Promote Colorectal Cancer Progression by Inhibiting Natural Killer Cells

The colon is the largest compartment of the immune system, with innate immune cells exposed to antigens in the environment. However, the mechanisms by which the innate immune system is instigated are poorly defined in colorectal cancer (CRC). Here, a population of CD16+ neutrophils that specifically accumulate in CRC tumor tissues by imaging mass cytometry (IMC), immune fluorescence, and flow cytometry, which demonstrated pro-tumor activity by disturbing natural killer (NK) cells are identified. It is found that these CD16+ neutrophils possess abnormal cholesterol accumulation due to activation of the CD16/TAK1/NF-κB axis, which upregulates scavenger receptors for cholesterol intake including CD36 and LRP1. Consequently, these region-specific CD16+ neutrophils not only competitively inhibit cholesterol intake of NK cells, which interrupts NK lipid raft formation and blocks their antitumor signaling but also release neutrophil extracellular traps (NETs) to induce the death of NK cells. Furthermore, CD16-knockout reverses the pro-tumor activity of neutrophils and restored NK cell cytotoxicity. Collectively, the findings suggest that CRC region-specific CD16+ neutrophils can be a diagnostic marker and potential therapeutic target for CRC.

Hydrogen sulfide mitigates ox‑LDL‑induced NLRP3/caspase‑1/GSDMD dependent macrophage pyroptosis by S‑sulfhydrating caspase‑1

Macrophage pyroptosis mediates vascular inflammation and atherosclerosis (AS). Hydrogen sulfide (H2S) exerts a protective role in preventing inflammation and AS. However, its molecular mechanisms of regulating the pyroptosis signaling pathway and inhibiting macrophage pyroptosis remain unexplored. The present study aimed to determine whether H2S mitigates macrophage pyroptosis by downregulating the pyroptosis signaling pathway and S‑sulfhydrating caspase‑1 under the stimulation of oxidized low‑density lipoprotein (ox‑LDL), a pro‑atherosclerotic factor. Macrophages derived from THP‑1 monocytes were pre‑treated using exogenous H2S donors sodium hydrosulfide (NaHS) and D,L‑propargylglycine (PAG), a pharmacological inhibitor of endogenous H2S‑producing enzymes, alone or in combination. Subsequently, cells were stimulated with ox‑LDL or the desulfhydration reagent dithiothreitol (DTT) in the presence or absence of NaHS and/or PAG. Following treatment, the levels of H2S in THP‑1 derived macrophages were measured by a methylene blue colorimetric assay. The pyroptotic phenotype of THP‑1 cells was observed and evaluated by light microscopy, Hoechst 33342/propidium iodide fluorescent staining and lactate dehydrogenase (LDH) release assay. Caspase‑1 activity in THP‑1 cells was assayed by caspase‑1 activity assay kit. Immunofluorescence staining was used to assess the accumulation of active caspase‑1. Western blotting and ELISA were performed to determine the expression of pyroptosis‑specific markers (NLRP3, pro‑caspase‑1, caspase‑1, GSDMD and GSDMD‑N) in cells and the secretion of pyroptosis‑related cytokines [interleukin (IL)‑1β and IL‑18] in the cell‑free media, respectively. The S‑sulfhydration of pro‑caspase‑1 in cells was assessed using a biotin switch assay. ox‑LDL significantly induced macrophage pyroptosis by activating the pyroptosis signaling pathway. Inhibition of endogenous H2S synthesis by PAG augmented the pro‑pyroptotic effects of ox‑LDL. Conversely, exogenous H2S (NaHS) ameliorated ox‑LDL‑and ox‑LDL + PAG‑induced macrophage pyroptosis by suppressing the activation of the pyroptosis signaling pathway. Mechanistically, ox‑LDL and the DTT increased caspase‑1 activity and downstream events (IL‑1β and IL‑18 secretion) of the caspase‑1‑dependent pyroptosis pathway by reducing S‑sulfhydration of pro‑caspase‑1. Conversely, NaHS increased S‑sulfhydration of pro‑caspase‑1, reducing caspase‑1 activity and caspase‑1‑dependent macrophage pyroptosis. The present study demonstrated the molecular mechanism by which H2S ameliorates macrophage pyroptosis by suppressing the pyroptosis signaling pathway and S‑sulfhydration of pro‑caspase‑1, thereby suppressing the generation of active caspase-1 and activity of caspase-1.

Role of inflammation and evidence for the use of colchicine in patients with acute coronary syndrome

Acute Coronary Syndrome (ACS) significantly contributes to cardiovascular death worldwide. ACS may arise from the disruption of an atherosclerotic plaque, ultimately leading to acute ischemia and myocardial infarction. In the pathogenesis of atherosclerosis, inflammation assumes a pivotal role, not solely in the initiation and complications of atherosclerotic plaque formation, but also in the myocardial response to ischemic insult. Acute inflammatory processes, coupled with time to reperfusion, orchestrate ischemic and reperfusion injuries, dictating infarct magnitude and acute left ventricular (LV) remodeling. Conversely, chronic inflammation, alongside neurohumoral activation, governs persistent LV remodeling. The interplay between chronic LV remodeling and recurrent ischemic episodes delineates the progression of the disease toward heart failure and cardiovascular death. Colchicine exerts anti-inflammatory properties affecting both the myocardium and atherosclerotic plaque by modulating the activity of monocyte/macrophages, neutrophils, and platelets. This modulation can potentially result in a more favorable LV remodeling and forestalls the recurrence of ACS. This narrative review aims to delineate the role of inflammation across the different phases of ACS pathophysiology and describe the mechanistic underpinnings of colchicine, exploring its purported role in modulating each of these stages.

TUDCA alleviates atherosclerosis by inhibiting AIM2 inflammasome and enhancing cholesterol efflux capacity in macrophage

Cholesterol efflux capacity (CEC) dysfunction in macrophages is important in atherosclerosis. However, the mechanism underlying CEC dysfunction remains unclear. We described the characteristics of ATF4 and inflammasome activation in macrophages during atherosclerosis through scRNA sequencing analysis. Then model of hyperlipemia was established in ApoE-/- mice; some were treated with tauroursodeoxycholic acid (TUDCA). TUDCA decreased the ATF4, Hspa, and inflammasome activation, reduced plaque area of the artery, and promoted CEC in macrophages. Furthermore, TUDCA abolished oxLDL-induced foam cell formation by inhibiting activation of the PERK/eIF2α/ATF4 and AIM2 inflammasome in macrophages. Further assays revealed ATF4 binding to AIM2 promoter, promoting its transcriptional activity significantly. Then we discovered that ATF4 affected AIM2-mediated foam cell formation by targeting ABCA1, which could be blocked by TUDCA. Our study demonstrated that TUDCA alleviates atherosclerosis by inhibiting AIM2 inflammasome and enhancing CEC of macrophage, which provided possibilities for the development of therapies.

Immunometabolism in atherosclerotic disorders

Cardiovascular diseases (CVDs), including atherosclerosis, myocardial infarction and heart failure, are the leading causes of morbidity and mortality worldwide. Emerging evidence suggests a crucial role for immune cell dysfunction and inflammation in the progression of this complex set of diseases. Recent advances demonstrate that immune cells, tightly linked to CVD pathogenesis, are sensitive to environmental signals and respond by engaging immunometabolic networks that shape their behavior. Inflammatory cues and altered nutrient availability within atherosclerotic plaques or following ischemia synergize to elicit metabolic shifts in immune cells that influence the course of disease pathology. Understanding these metabolic adaptations and how they contribute to cellular dysfunction may reveal novel therapeutic approaches for the treatment of CVD. Here we provide a comprehensive summary of the metabolic reprogramming that occurs in immune cells and their progenitors during CVD, offering insights into the potential therapeutic interventions to mitigate disease progression.

Targeting pyroptosis to treat ischemic stroke: From molecular pathways to treatment strategy

Ischemic stroke is the primary reason for human disability and death, but the available treatment options are limited. Hence, it is imperative to explore novel and efficient therapies. In recent years, pyroptosis (a pro-inflammatory cell death characterized by inflammation) has emerged as an important pathological mechanism in ischemic stroke that can cause cell death through plasma membrane rupture and release of inflammatory cytokines. Pyroptosis is closely associated with inflammation, which exacerbates the inflammatory response in ischemic stroke. The level of inflammasomes, GSDMD, Caspases, and inflammatory factors is increased after ischemic stroke, exacerbating brain injury by mediating pyroptosis. Hence, inhibition of pyroptosis can be a therapeutic strategy for ischemic stroke. In this review, we have summarized the relationship between pyroptosis and ischemic stroke, as well as a series of treatments to attenuate pyroptosis, intending to provide insights for new therapeutic targets on ischemic stroke.

Statin administration or blocking PCSK9 alleviates airway hyperresponsiveness and lung fibrosis in high-fat diet-induced obese mice

BACKGROUND

Obesity is associated with airway hyperresponsiveness and lung fibrosis, which may reduce the effectiveness of standard asthma treatment in individuals suffering from both conditions. Statins and proprotein convertase subtilisin/kexin-9 inhibitors not only reduce serum cholesterol, free fatty acids but also diminish renin-angiotensin system activity and exhibit anti-inflammatory effects. These mechanisms may play a role in mitigating lung pathologies associated with obesity.

METHODS

Male C57BL/6 mice were induced to develop obesity through high-fat diet for 16 weeks. Conditional TGF-β1 transgenic mice were fed a normal diet. These mice were given either atorvastatin or proprotein convertase subtilisin/kexin-9 inhibitor (alirocumab), and the impact on airway hyperresponsiveness and lung pathologies was assessed.

RESULTS

High-fat diet-induced obesity enhanced airway hyperresponsiveness, lung fibrosis, macrophages in bronchoalveolar lavage fluid, and pro-inflammatory mediators in the lung. These lipid-lowering agents attenuated airway hyperresponsiveness, macrophages in BALF, lung fibrosis, serum leptin, free fatty acids, TGF-β1, IL-1β, IL-6, and IL-17a in the lung. Furthermore, the increased RAS, NLRP3 inflammasome, and cholecystokinin in lung tissue of obese mice were reduced with statin or alirocumab. These agents also suppressed the pro-inflammatory immune responses and lung fibrosis in TGF-β1 over-expressed transgenic mice with normal diet.

CONCLUSIONS

Lipid-lowering treatment has the potential to alleviate obesity-induced airway hyperresponsiveness and lung fibrosis by inhibiting the NLRP3 inflammasome, RAS and cholecystokinin activity.

IRE1α: from the function to the potential therapeutic target in atherosclerosis

Inositol requiring enzyme 1 (IRE1) is generally thought to control the most conserved pathway in the unfolded protein response (UPR). Two isoforms of IRE1, IRE1α and IRE1β, have been reported in mammals. IRE1α is a ubiquitously expressed protein whose knockout shows marked lethality. In contrast, the expression of IRE1β is exclusively restricted in the epithelial cells of the respiratory and gastrointestinal tracts, and IRE1β-knockout mice are phenotypically normal. As research continues to deepen, IRE1α was showed to be tightly linked to inflammation, lipid metabolism regulation, cell death and so on. Growing evidence also suggests an important role for IRE1α in promoting atherosclerosis (AS) progression and acute cardiovascular events through disrupting lipid metabolism balance, facilitating cells apoptosis, accelerating inflammatory responses and promoting foam cell formation. In addition, IRE1α was recognized as novel potential therapeutic target in AS prevention. This review provides some clues about the relationship between IRE1α and AS, hoping to contribute to further understanding roles of IRE1α in atherogenesis and to be helpful for the design of novel efficacious therapeutics agents targeting IRE1α-related pathways.

SENP3 attenuates foam cell formation by deSUMOylating NLRP3 in macrophages stimulated with ox-LDL

SUMO-specific protease 3 (SENP3) participates in the removal of SUMOylation and maintains the balance of the SUMO system, which ensures normal functioning of substrates and cellular activities. In the present study, we found that SENP3 expression was significantly reduced in ox-LDL-stimulated macrophages. SENP3 overexpression suppressed and SENP3 knockdown promoted macrophage foam cell formation. Moreover, SENP3 inhibited cholesterol uptake, CD36 expression, and NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome activation in ox-LDL-stimulated macrophages. Ox-LDL-stimulated NLRP3 SUMOylation was reduced by SENP3. Blocking NLRP3 SUMOylation inhibited foam cell formation and NLRP3 inflammasome activation. Thus, this study revealed that SENP3 inhibits macrophage foam cell formation by deSUMOylating NLRP3 and regulating NLRP3 inflammasome activation, which may provide a potentially innovative approach to treatment of atherosclerosis.

The role of immune cells in different stages of atherosclerosis

Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of immune cells in the intima of arteries. Experimental and clinical evidence shows that both innate and adaptive immunity orchestrate the progression of atherosclerosis. The heterogeneous nature of immune cells within atherosclerosis lesions is important. Studies utilizing high-dimensional mass spectrometry and single-cell RNA sequencing of leukocytes from atherosclerotic lesions show the diversity and adaptability of these immune cell subtypes. Their migration, compositional changes, phenotypic alterations, and adaptive responses are key features throughout atherosclerosis progression. Understanding how these immune cells and their subtypes affect atherogenesis would help to develop novel therapeutic approaches that control atherosclerosis progression. Precise targeting of specific immune system components involved in atherosclerosis, rather than broad suppression of the immune system with anti-inflammatory agents, can more accurately regulate the progress of atherosclerosis with fewer side effects. In this review, we cover the most recent advances in the field of atherosclerosis to understand the role of various immune cells on its development. We focus on the complex network of immune cells and the interaction between the innate immune system and adaptive immune system.

Disulfiram Reduces Atherosclerosis and Enhances Efferocytosis, Autophagy, and Atheroprotective Gut Microbiota in Hyperlipidemic Mice

BACKGROUND

Pyroptosis executor GsdmD (gasdermin D) promotes atherosclerosis in mice and humans. Disulfiram was recently shown to potently inhibit GsdmD, but the in vivo efficacy and mechanism of disulfiram's antiatherosclerotic activity is yet to be explored.

METHODS AND RESULTS

We used human/mouse macrophages, endothelial cells, and smooth muscle cells and a hyperlipidemic mouse model of atherosclerosis to determine disulfiram antiatherosclerotic efficacy and mechanism. The effects of disulfiram on several atheroprotective pathways such as autophagy, efferocytosis, phagocytosis, and gut microbiota were determined. Atomic force microscopy was used to determine the effects of disulfiram on the biophysical properties of the plasma membrane of macrophages. Disulfiram-fed hyperlipidemic apolipoprotein E-/- mice showed significantly reduced interleukin-1β release upon in vivo Nlrp3 (NLR family pyrin domain containing 3) inflammasome activation. Disulfiram-fed mice showed smaller atherosclerotic lesions (~27% and 29% reduction in males and females, respectively) and necrotic core areas (~50% and 46% reduction in males and females, respectively). Disulfiram induced autophagy in macrophages, smooth muscle cells, endothelial cells, hepatocytes/liver, and atherosclerotic plaques. Disulfiram modulated other atheroprotective pathways (eg, efferocytosis, phagocytosis) and gut microbiota. Disulfiram-treated macrophages showed enhanced phagocytosis/efferocytosis, with the mechanism being a marked increase in cell-surface expression of efferocytic receptor MerTK. Atomic force microscopy analysis revealed altered biophysical properties of disulfiram-treated macrophages, showing increased order-state of plasma membrane and increased adhesion strength. Furthermore, 16sRNA sequencing of disulfiram-fed hyperlipidemic mice showed highly significant enrichment in atheroprotective gut microbiota Akkermansia and a reduction in atherogenic Romboutsia species.

CONCLUSIONS

Taken together, our data show that disulfiram can simultaneously modulate several atheroprotective pathways in a GsdmD-dependent as well as GsdmD-independent manner.

The IRG1-itaconate axis protects from cholesterol-induced inflammation and atherosclerosis

Atherosclerosis is fueled by a failure to resolve lipid-driven inflammation within the vasculature that drives plaque formation. Therapeutic approaches to reverse atherosclerotic inflammation are needed to address the rising global burden of cardiovascular disease (CVD). Recently, metabolites have gained attention for their immunomodulatory properties, including itaconate, which is generated from the tricarboxylic acid-intermediate cis-aconitate by the enzyme Immune Responsive Gene 1 (IRG1/ACOD1). Here, we tested the therapeutic potential of the IRG1-itaconate axis for human atherosclerosis. Using single-cell RNA sequencing (scRNA-seq), we found that IRG1 is up-regulated in human coronary atherosclerotic lesions compared to patient-matched healthy vasculature, and in mouse models of atherosclerosis, where it is primarily expressed by plaque monocytes, macrophages, and neutrophils. Global or hematopoietic Irg1-deficiency in mice increases atherosclerosis burden, plaque macrophage and lipid content, and expression of the proatherosclerotic cytokine interleukin (IL)-1β. Mechanistically, absence of Irg1 increased macrophage lipid accumulation, and accelerated inflammation via increased neutrophil extracellular trap (NET) formation and NET-priming of the NLRP3-inflammasome in macrophages, resulting in increased IL-1β release. Conversely, supplementation of the Irg1-itaconate axis using 4-octyl itaconate (4-OI) beneficially remodeled advanced plaques and reduced lesional IL-1β levels in mice. To investigate the effects of 4-OI in humans, we leveraged an ex vivo systems-immunology approach for CVD drug discovery. Using CyTOF and scRNA-seq of peripheral blood mononuclear cells treated with plasma from CVD patients, we showed that 4-OI attenuates proinflammatory phospho-signaling and mediates anti-inflammatory rewiring of macrophage populations. Our data highlight the relevance of pursuing IRG1-itaconate axis supplementation as a therapeutic approach for atherosclerosis in humans.

Circulating microRNA-33b levels are associated with the presence and severity of coronary heart disease

MicroRNA-33b (miR-33b) affected various biological pathways in regulating cholesterol homeostasis which may link to the pathogenesis of atherosclerotic lesions. However, whether this marker is associated with the presence and severity of coronary heart disease (CHD) is undetermined. We aim to explore the diagnostic value of circulating miR-33b level in the presence and severity of CHD. Altogether 320 patients were enrolled, including 240 patients diagnosed with CHD while 80 were classified as controls after CAG examination. Circulating miR-33b level was analyzed in all subjects, the Gensini score was calculated to assess the severity of stenotic lesions. The association between miR-33b and the presence and severity of CHD was analyzed, and the diagnostic potential of miR-33b of CHD was performed by the receiver operating characteristic (ROC) analysis. The CHD group had higher miR-33b levels (p < 0.001), and the miR-33b content significantly elevated following an increasing Gensini score (p for trend < 0.001). After adjustments for potential risk factors, such as several blood lipid markers, miR-33b remained a significant determinant for CHD (p < 0.001). ROC analysis disclosed that the AUC was 0.931. The optimal cutoff value of miR-33b was with a sensitivity of 81.3% and a specificity of 98.7% in differentiating CHD. It can prognosticate that the higher level of miR-33b was linked to increased severity of disease in CHD patients. Thus, the application of this marker might assist in the diagnosis and classification of CHD patients. Nevertheless, additional studies with larger sample sizes will be required to verify these results.

Association of a low-inflammatory diet with survival among adults: The role of cardiometabolic diseases and lifestyle

BACKGROUND & AIMS

Evidence on the association between dietary inflammation and longevity is limited. We aimed to examine the association of a low-inflammatory diet with mortality and longevity, and to explore whether cardiometabolic diseases (CMDs) and lifestyle factors may play a role in this association.

METHODS

Within the UK Biobank, 188,443 participants aged 39-72 years (mean 56.07) were followed for up to 16 years to detect survival status from the death registry. At baseline, dietary intake was assessed with a 24-h dietary record. An inflammatory diet index (IDI) was calculated as weighted sum of 31 food groups (including 14 anti-inflammatory and 17 pro-inflammatory) based on plasma high-sensitivity C-reactive protein levels, and tertiled as low, moderate, and high IDI scores. Baseline lifestyle beyond diet was assessed by summing the number of healthy lifestyle factors (i.e., never smoking, regular physical activity, and normal BMI) and categorized as unfavorable (≤1) and favorable (≥2). Presence of CMDs was defined as having any one of type 2 diabetes, ischemic heart disease, atrial fibrillation, heart failure, and stroke. Data were analyzed using Cox regression, Laplace regression, and generalized structural equation modelling.

RESULTS

During the follow-up (median 9.79 years, interquartile range: 9.68-10.57 years), 9178 (4.9%) participants died. In multi-adjusted Cox regression models, a low-inflammatory diet (i.e. low IDI score) was associated with lower risk of all-cause mortality [hazard ratio (HR) = 0.82, 95% confidence interval (CI): 0.78 to 0.86]. Laplace regression analysis showed that the multi-adjusted 10th percentile difference (10th PD, 95% CI) of death time was delayed by 0.80 (0.55, 1.06; P < 0.001) years for participants with a low IDI score compared to those with a high IDI score. In mediation analysis, 21.48% of the association between IDI and mortality was mediated by CMDs. In joint effect analysis, participants with a low IDI score and favorable lifestyle had a 42% lower risk of death (HR = 0.58, 95% CI: 0.54, 0.62) compared to those with a high IDI score and unfavorable lifestyle. There was a significant additive interaction between low IDI score and favorable lifestyle on decreased mortality.

CONCLUSIONS

A low-inflammatory diet is associated with a lower risk of death and could prolong survival time. CMDs may partially mediate the IDI-mortality association. A favorable lifestyle beyond diet may augment the positive effect of a low-inflammatory diet on longevity.

Cholesterol trafficking to the ER leads to the activation of CaMKII/JNK/NLRP3 and promotes atherosclerosis

The deposition of cholesterol-rich lipoproteins in the arterial wall triggers macrophage inflammatory responses, which promote atherosclerosis. The NLRP3 inflammasome aggravates atherosclerosis; however, cellular mechanisms connecting macrophage cholesterol accumulation to inflammasome activation are poorly understood. We investigated the mechanisms of NLRP3 inflammasome activation in cholesterol-loaded macrophages and in atherosclerosis-prone Ldlr-/- mice with defects in macrophage cholesterol efflux. We found that accumulation of cholesterol in macrophages treated with modified LDL or cholesterol crystals, or in macrophages defective in the cholesterol efflux promoting transporters ABCA1 and ABCG1, leads to activation of NLRP3 inflammasomes as a result of increased cholesterol trafficking from the plasma membrane to the ER, via Aster-B. In turn, the accumulation of cholesterol in the ER activates the inositol triphosphate-3 receptor, CaMKII/JNK, and induces NLRP3 deubiquitylation by BRCC3. An NLRP3 deubiquitylation inhibitor or deficiency of Abro1, an essential scaffolding protein in the BRCC3-containing cytosolic complex, suppressed inflammasome activation, neutrophil extracellular trap formation (NETosis), and atherosclerosis in vivo. These results identify a link between the trafficking of cholesterol to the ER, NLRP3 deubiquitylation, inflammasome activation, and atherosclerosis.

Association between high-density lipoprotein cholesterol and type 2 diabetes mellitus: dual evidence from NHANES database and Mendelian randomization analysis

Background

Low levels of high-density lipoprotein cholesterol (HDL-C) are commonly seen in patients with type 2 diabetes mellitus (T2DM). However, it is unclear whether there is an independent or causal link between HDL-C levels and T2DM. This study aims to address this gap by using the The National Health and Nutrition Examination Survey (NHANES) database and Mendelian randomization (MR) analysis.

Materials and methods

Data from the NHANES survey (2007-2018) with 9,420 participants were analyzed using specialized software. Logistic regression models and restricted cubic splines (RCS) were used to assess the relationship between HDL-C and T2DM incidence, while considering covariates. Genetic variants associated with HDL-C and T2DM were obtained from genome-wide association studies (GWAS), and Mendelian randomization (MR) was used to evaluate the causal relationship between HDL-C and T2DM. Various tests were conducted to assess pleiotropy and outliers.

Results

In the NHANES study, all groups, except the lowest quartile (Q1: 0.28-1.09 mmol/L], showed a significant association between HDL-C levels and reduced T2DM risk (all P < 0.001). After adjusting for covariates, the Q2 [odds ratio (OR) = 0.67, 95% confidence interval (CI): (0.57, 0.79)], Q3 [OR = 0.51, 95% CI: (0.40, 0.65)], and Q4 [OR = 0.29, 95% CI: (0.23, 0.36)] groups exhibited average reductions in T2DM risk of 23%, 49%, and 71%, respectively. In the sensitivity analysis incorporating other lipid levels, the Q4 group still demonstrates a 57% reduction in the risk of T2DM. The impact of HDL-C levels on T2DM varied with age (P for interaction = 0.006). RCS analysis showed a nonlinear decreasing trend in T2DM risk with increasing HDL-C levels (P = 0.003). In the MR analysis, HDL-C levels were also associated with reduced T2DM risk (OR = 0.69, 95% CI = 0.52-0.82; P = 1.41 × 10-13), and there was no evidence of pleiotropy or outliers.

Conclusion

This study provides evidence supporting a causal relationship between higher HDL-C levels and reduced T2DM risk. Further research is needed to explore interventions targeting HDL-C levels for reducing T2DM risk.

Macrophage pyroptosis induced by Candida albicans

Candida albicans (C. albicans) is a prevalent opportunistic pathogen that causes mucocutaneous and systemic infections, particularly in immunocompromised individuals. Macrophages play a crucial role in eliminating C. albicans in local and bloodstream contexts, while also regulating antifungal immune responses. However, C. albicans can induce macrophage lysis through pyroptosis, a type of regulated cell death. This process can enable C. albicans to escape from immune cells and trigger the release of IL-1β and IL-18, which can impact both the host and the pathogen. Nevertheless, the mechanisms by which C. albicans triggers pyroptosis in macrophages and the key factors involved in this process remain unclear. In this review, we will explore various factors that may influence or trigger pyroptosis in macrophages induced by C. albicans, such as hypha, ergosterol, cell wall remodeling, and other virulence factors. We will also examine the possible immune response following macrophage pyroptosis.

The amelioration of a purified Pleurotus abieticola polysaccharide on atherosclerosis in ApoE-/- mice

In this study, a polysaccharide known as PAPS2 was eluted from Pleurotus abieticola fruiting bodies using 0.1 M NaCl solutions. PAPS2 has a Mw of 19.64 kDa and its backbone is mainly composed of →6)-α-D-Galp-(1→, →6)-β-D-Glcp-(1→ and →2,6)-α-D-Galp-(1→ residues, and its branches mainly end with β-D-Manp-(1→, which is attached at C2 of →2,6)-α-D-Galp-(1→. PAPS2 elicited several effects in high-fat diet (HFD)-fed ApoE-/- mice. It significantly reduced the body weight, liver index, and serum levels of total cholesterol (TC) and triglycerides (TGs), and it alleviated lipid accumulation in the aorta. Intestinal microflora analysis showed that PAPS2 suppressed the abundances of Adlercreutzia, Turicibacter, and Helicobacter and enriched that of Roseburia. It also influenced lipid metabolism, suggesting that it reduced the levels of TGs, lysophosphatidylcholine (LPC), phosphatidylcholine (PC), and ceramide (Cer). Moreover, it suppressed oxidative response by increasing nuclear factor erythroid 2 (Nrf2)-related factor expression and activating the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) to reduce the level of reactive oxygen species (ROS). Meanwhile, it showed anti-inflammatory effects partially related to the inhibition of toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) signaling induced by lipopolysaccharide (LPS) in RAW 264.7 cells, as well as in the aorta of HFD-fed ApoE-/- mice. This study provides experimental evidence of the auxiliary applicability of PAPS2 in atherosclerosis treatment.