CD36 in Atherosclerosis: Pathophysiological Mechanisms and Therapeutic Implications

LncRNA AC100865.1 regulates macrophage adhesion and ox-LDL intake through miR-7/GDF5 pathway

OBJECTIVES

Cardiovascular disease (CVD) accounts for over 40 % of deaths related to diseases among residents. Atherosclerosis (AS) and its associated thrombosis are the primary causes of CVD. LncRNA AC100865.1, a newly identified lncRNA, has shown potential as a diagnostic biomarker for AS. This study aims to evaluate the therapeutic value of lncRNA AC100865.1 in AS.

METHODS

Real-time PCR was conducted to assess the relative expression of lncRNA AC100865.1 in Peripheral Blood Mononuclear Cell (PBMC) samples from 50 CVD patients and 50 healthy controls. lncRNA AC100865.1 was overexpressed in RAW264.7 cells to measure its effects on adhesion and oxidized low-density lipoprotein (ox-LDL) uptake. Flow cytometry was utilized to identify the pathway mediating these processes. The luciferase assay and knockout rescue experiments were performed to elucidate the downstream signaling pathways involved.

RESULTS

lncRNA AC100865.1 expression was found to be downregulated in CVD patients. Overexpression of lncRNA AC100865.1 significantly enhanced the adhesion capacity of RAW264.7 cells. Luciferase reporter assays and flow cytometry indicated that this effect is mediated through the miR-7/GDF5/p38/LFA-1 pathway. Furthermore, lncRNA AC100865.1 notably increased ox-LDL uptake by macrophages via upregulation of CD36 expression.

CONCLUSION

Overexpression of lncRNA AC100865.1 enhances the adhesion of RAW264.7 cells through the miR-7/GDF5/p38/LFA-1 pathway and increases ox-LDL uptake by elevating CD36 levels. These findings suggest that circulating lncRNA AC100865.1 may serve not only as an early diagnostic marker for CVD but also as a potential therapeutic target, offering new prospects for CVD treatment.

Experimental evidence on colchicine's mode of action in human carotid artery plaques

BACKGROUND AND AIMS

Atherosclerosis, driven by inflammation, is a leading cause of cardiovascular events. Recent clinical trials have highlighted the therapeutic potential of anti-inflammatory treatments. Consequently, colchicine is being recommended for secondary prevention in current guidelines, although the drug's mechanistic actions are not fully understood.

METHODS

To this end, we conducted a multiomic investigation of colchicine's effect on human carotid plaques. Sections from endarterectomy specimens were exposed to colchicine at concentrations of 2 ng/ml and 10 ng/ml ex vivo for 24 h and compared to untreated segments of the same plaque. Gene expression changes were analyzed by bulk RNA sequencing, and plaque secretomes underwent mass spectrometry for proteomic analysis. In situ cell proliferation was assessed by histology.

RESULTS

Our data indicate, that colchicine suppresses neutrophil and platelet degranulation and activation, collagen degradation and atheromatous plaque macrophage proliferation in a dose-dependent manner in human plaques, while stimulating myofibroblast activation. Unexpectedly, interleukine (IL)-1beta release from colchicine treated plaques was not reduced. These results indicate that the inflammasome may not be the predominant target of low-dose colchicine in human carotid artery plaques.

CONCLUSION

Our study identifies multifactorial pathways through which colchicine, the first cardiovascular guideline-recommended anti-inflammatory drug, predominantly acts on human atherosclerotic lesions beyond the inflammasome. Targeting neutrophil and platelet degranulation, collagen degradation and macrophage proliferation, selectively, may provide substantial therapeutic benefit in atherosclerotic cardiovascular disease without colchicine's undesired side effects.

Formononetin attenuates myocardial ischemia/reperfusion injury by regulating neutrophil extracellular traps formation and platelet activation via platelet CD36

BACKGROUND

Prothrombotic and proinflammatory responses are crucial in the pathology of myocardial ischemia-reperfusion injury (MIRI). Platelets and neutrophil extracellular traps (NETs) are essential to linking inflammation with thrombosis. Formononetin (FMN), an isoflavone extracted from Astragalus membranaceus, has anti-inflammatory and anti-thrombotic effects and confers benefits on MIRI. However, the mechanisms of FMN against MIRI remain unclear.

PURPOSE

This study explored FMN's roles and mechanisms in modulating platelet activation and NETs formation to mitigate MIRI.

STUDY DESIGN AND METHODS

A rat model of MIRI by the left anterior descending coronary artery ligation was utilized to evaluate the role of FMN. 60 Sprague-Dawley male rats were randomly divided into 7 groups. Proteomics, flow cytometry, immunofluorescence, ELISA, and western blotting assays were performed to reveal the potential mechanisms of FMN. Neutrophils treated with platelet-rich plasma were applied to further explore the mechanisms of FMN in vitro.

RESULTS

We showed that FMN administration declined myocardial infarct size and improved cardiac function. Moreover, FMN significantly reduced MIRI-induced platelet activation including platelet aggregation, platelet adhesion, platelet granule secretion, and platelet-leukocyte aggregation without affecting tail bleeding time. Additionally, FMN inhibited microthrombus, platelet-neutrophil aggregation, and NETs formation in myocardial tissue. Mechanistically, FMN attenuated MIRI-induced CD36 expression and phosphorylation of ERK5 in platelets. Furthermore, up-regulation of CD36 content in vitro counteracted the potency of FMN to inhibit platelet activation and NETs formation.

CONCLUSION

FMN mitigates thrombosis and inflammation in MIRI by inhibiting platelet activation and NETs formation via the CD36 pathway. This research offers important insights for future studies on MIRI prevention.

Endothelial Stiffening Induced by CD36-Mediated Lipid Uptake Leads to Endothelial Barrier Disruption and Contributes to Atherosclerotic Lesions

BACKGROUND

Endothelial stiffening induced by Western diet was proposed to be an important factor in vascular dysfunction. In this study, we determine the role of endothelial CD36 (cluster of differentiation 36) in stiffening, disruption of aortic endothelial barrier, and atherosclerosis in mouse models of obesity and hypercholesterolemia.

METHODS

To address this goal, we generated an endothelial-specific inducible knockdown mouse model of CD36, Cdh5.CreERT2CD36fl/fl, on C57/BL6J wild-type and LDLR-/- genetic backgrounds. Endothelial stiffness is assessed by atomic force microscopy; endothelial barrier integrity is assessed by imaging VE (vascular endothelium)-cadherin junctions and by penetration of Evans blue dye into the aortic wall. Atherosclerotic plaques are quantified using oil red O staining.

RESULTS

Endothelial-specific downregulation of CD36 abrogates stiffening of aortic endothelium induced by Western diet in Cdh5.CreERT2CD36fl/fl and in Cdh5.CreERT2CD36fl/flLDLR-/- mice. Prevention of Western diet-induced endothelial stiffening by downregulation of CD36 is associated with a protective effect against endothelial barrier disruption in both mouse models and with a significant decrease in the areas of atherosclerotic lesions in Cdh5.CreERT2CD36fl/flLDLR-/- mice. Mechanistically, stiffening of human aortic endothelial cells in vitro is induced by saturated fatty acids, particularly palmitic acid (PA), which results in activation of RhoA. Both PA-induced endothelial stiffening and RhoA activation are abrogated by CD36 siRNA. Furthermore, PA-induced endothelial stiffening of excised aortas ex vivo is lost in aortas isolated from mice, where endothelial CD36 is downregulated. We also demonstrate that PA-induced activation of RhoA and endothelial stiffening require expressing an RhoA-inhibitory protein, Rho-GDI1 (Rho guanosine dissociation inhibitor 1). Finally, we discover that PA disrupts the colocalization of RhoA with Rho-GDI1.

CONCLUSIONS

We conclude that stiffening of the aortic endothelium by CD36-mediated uptake of fatty acids contributes significantly to Western diet-induced vascular dysfunction and atherosclerosis. We further propose that fatty acids may activate RhoA by inducing its dissociation from Rho-GDI1.

Inhibition of CD36 ameliorates mouse spinal cord injury by accelerating microglial lipophagy

Spinal cord injury (SCI) is a serious trauma of the central nervous system (CNS). SCI induces a unique lipid-dense environment that results in the deposition of large amounts of lipid droplets (LDs). The presence of LDs has been shown to contribute to the progression of other diseases. Lipophagy, a selective type of autophagy, is involved in intracellular LDs degradation. Fatty acid translocase CD36, a multifunctional transmembrane protein that facilitates the uptake of long-chain fatty acids, is implicated in the progression of certain metabolic diseases, and negatively regulates autophagy. However, the precise mechanisms of LDs generation and degradation in SCI, as well as whether CD36 regulates SCI via lipophagy, remain unknown. In this study, we investigated the role of LDs accumulation in microglia for SCI, as well as the regulatory mechanism of CD36 in microglia lipophagy during LDs elimination in vivo and in vitro. SCI was induced in mice by applying moderate compression on spina cord at T9-T10 level. Locomotion recovery was evaluated at days 0, 1, 3, 7 and 14 following the injury. PA-stimulated BV2 cells was established as the in vitro lipid-loaded model. We observed a marked buildup of LDs in microglial cells at the site of injury post-SCI. More importantly, microglial cells with excessive LDs exhibited elevated activation and stimulated inflammatory response, which drastically triggered the pyroptosis of microglial cells. Furthermore, we found significantly increased CD36 expression, and the breakdown of lipophagy in microglia following SCI. Sulfo-N-succinimidyl oleate sodium (SSO), a CD36 inhibitor, has been shown to promote the lipophagy of microglial cells in SCI mice and PA-treated BV2 cells, which enhanced LDs degradation, ameliorated inflammatory levels and pyroptosis of microglial cells, and ultimately promoted SCI recovery. As expected, inhibition of lipophagy with Baf-A1 reversed the effects of SSO. We conclude that microglial lipophagy is essential for the removal of LDs during SCI recovery. Our research implies that CD36 could be a potential therapeutic target for the treatment and management of SCI.

Advanced Detection and Therapeutic Monitoring of Atherosclerotic Plaque Using CD36-Targeted Lipid Core Probe

Background: Atherosclerotic diseases, including coronary heart disease and cerebrovascular disease, are leading causes of morbidity and mortality worldwide. Atherosclerosis is a chronic vascular condition marked by the accumulation of lipid plaque within arterial walls. These plaques can become unstable and rupture, leading to thrombosis and subsequent cardiovascular events. Therefore, early identification of vulnerable plaque is critical for preventing such events. Objectives: This study aims to develop a novel imaging platform for atherosclerotic plaque by designing a molecular imaging probe based on fluorescent molecules that target lipid necrotic cores. The goal is to specifically detect high-risk plaque, enabling early diagnosis and intervention. Methods: Bioinformatic analysis and immunofluorescence were used to detect CD36 expression in human carotid plaque. CD36pep-ICG was synthesized using the Fmoc solid-phase peptide method. A series of experiments was conducted to characterize the probe's properties. To assess imaging performance, probe concentration gradients were tested using FLI equipment. Ex vivo imaging was performed on atherosclerotic mice and treatment models to evaluate the probe's targeting ability and effectiveness in monitoring disease progression. Results: The CD36 expression was significantly elevated in the core of plaque compared to distal regions. The CD36pep-ICG probe, specifically designed to target lipids, was successfully synthesized and exhibited excellent fluorescence properties. In animal models, FLI imaging demonstrated that the CD36pep-ICG probe selectively accumulated in atherosclerotic plaque, enabling precise plaque detection. Moreover, the probe was used to monitor the therapeutic efficacy of anti-atherosclerotic drugs. Conclusions: The CD36pep-ICG probe developed in this study is an effective molecular imaging tool for the specific identification of vulnerable atherosclerotic plaque, offering a novel approach for early diagnosis and treatment. Additionally, the probe shows promise in tracking the therapeutic effects of the drug, potentially advancing the precision treatment of cardiovascular diseases.

Therapeutic Targeting of Pattern Recognition Receptors to Modulate Inflammation in Atherosclerosis

Atherosclerosis (AS), a potentially fatal cardiovascular disease (CVD), is a chronic inflammatory condition. The disease's onset and progression are influenced by inflammatory and immunological mechanisms. The innate immune pathways are essential in the progression of AS, as they are responsible for detecting first danger signals and causing long-term changes in immune cells. The innate immune system possesses distinct receptors known as pattern recognition receptors (PRRs) which can identify both pathogen-associated molecular patterns and danger-associated molecular signals. Activation of PRRs initiates the inflammatory response in various physiological systems, such as the cardiovascular system. This review specifically examines the contribution of the innate immune response and PRRs to the formation and advancement of AS. Studying the role of these particular receptors in AS would enhance our understanding of the development of AS and offer novel approaches for directly improving the inflammatory response associated with it.

Inherited Dyslipidemic Splenomegaly: A Genetic Macrophage Storage Disorder Caused by Disruptive Apolipoprotein E (APOE) Variants

BACKGROUND

Persistent splenomegaly, often an incidental finding, can originate from a number of inherited metabolic disorders (IMDs). Variants of APOE are primarily known as risk factors in terms of cardiovascular disease; however, severe dysfunction of APOE can result in a disease phenotype with considerable overlap with lysosomal storage disorders (LSDs), including splenomegaly and gross elevation of N-palmitoyl-O-phosphocholine-serine (PPCS).

METHODS

A case study (deep phenotyping, genetic and FACS analysis) and literature study was conducted.

RESULTS

The index patient, with a family history of early-onset cardiovascular disease, presented with splenic infarctions in a grossly enlarged spleen. The identified genetic cause was homozygosity for two APOE variants (c.604C>T, p.(Arg202Cys) and c.512G>A, p.(Gly171Asp); ε1/ε1), resulting in a macrophage storage phenotype resembling an LSD that was also present in the brother of the index patient. A FACS analysis of the circulating monocytes showed increased lipid content and the expression of activation markers (CD11b, CCR2, CD36). This activated state enhances lipoprotein intake, which eventually converts these monocytes/macrophages into foam cells, accumulating in tissues (e.g., spleen and vascular wall). A literature search identified seven individuals with splenomegaly caused by APOE variants (deletion of leucine at position 167). The combined data from all patients identified male gender, splenectomy and obesity as potential modifiers determining the severity of the phenotype (i.e., degree of triglyceride increase in plasma and/or spleen size). Symptoms are (partially) reversible by lipid-lowering medication and energy restricted diets and splenectomy is contra-indicated.

CONCLUSIONS

Inherited dyslipidemic splenomegaly caused by disruptive APOE variants should be included in the differential diagnoses of unexplained splenomegaly with abnormal lipid profiles. A plasma lipid profile consistent with dysbetalipoproteinemia is a diagnostic biomarker for this IMD.

SOX11 silence inhibits atherosclerosis progression in ApoE-deficient mice by alleviating endothelial dysfunction

SRY-Box Transcription Factor-11 (SOX11) is a transcriptional regulatory factor that plays a crucial role in inflammatory responses. However, its involvement in atherosclerosis (AS), a cardiovascular disease driven by endothelial cell inflammation, remains unknown. This study aims to elucidate the role of SOX11 in AS. The expression of SOX11 was found to be elevated in the aortic tissue of AS mice induced by feeding ApoE-deficient mice a high-fat diet. Knockdown of SOX11 using lentiviral-mediated SOX11-specific shRNA via tail vein injection resulted in a reduction in plaque area and lipid deposition within plaques at the aortic root. Furthermore, silencing SOX11 led to decreased expression of cell adhesion factors Intercellular Cell Adhesion Molecule-1 and Vascular Cell Adhesion Molecule-1, as well as reduced levels of inflammatory factors Interleukin (IL)-6, IL-1β, and chemokine Monocyte Chemotactic Protein-1. In the human umbilical vein endothelial cells (HUVECs) induced by Tumor Necrosis Factor (TNF)-α, increased inflammation was observed at the cellular level, along with enhanced monocyte adhesion. Infection of HUVECs with lentivirus carrying specific shRNA targeting SOX11 inhibited inflammatory response. Mechanistically, chromatin immunoprecipitation (ChIP)-PCR results revealed that SOX11 bound to the promoters of downstream target genes Tumor Necrosis Factor Receptor-Associated Factor-1 (TRAF1), Cluster of Differentiation (CD)40, and CD36, positively regulating their transcription. In conclusion, SOX11 plays a pivotal role in promoting endothelial cell inflammation. Suppression of SOX11 reduces endothelial cell inflammation by inhibiting the transcription of TRAF1, CD40, and CD36, thereby impeding the progression of atherosclerosis.

Role of ABCA1 in Atherosclerosis: Novel Mutations and Potential Plant-derived Therapies

ATP-binding cassette transporter A1 (ABCA1) is one of the key proteins regulating cholesterol homeostasis and playing a crucial role in atherosclerosis development. ABCA1 regulates the rate-limiting step of reverse cholesterol transport, facilitates the efflux of surplus intracellular cholesterol and phospholipids, and suppresses inflammation through several signalling pathways. At the same time, many mutations and Single Nucleotide Polymorphisms (SNPs) have been identified in the ABCA1 gene, which affects its biological function and is associated with several hereditary diseases (such as familial hypo-alpha-lipoproteinaemia and Tangier disease) and increased risk of cardiovascular diseases (CVDs). This review summarises recently identified mutations and SNPs in their connection to atherosclerosis and associated CVDs. Also, we discuss the recently described application of various plant-derived compounds to modulate ABCA1 expression in different in vitro and in vivo models. Herein, we present a comprehensive overview of the association of ABCA1 mutations and SNPs with CVDs and as a pharmacological target for different natural-derived compounds and highlight the potential application of these phytochemicals for treating atherosclerosis through modulation of ABCA1 expression.

Assessing platelet-derived extracellular vesicles for potential as therapeutic targets in cardiovascular diseases

INTRODUCTION

Cardiovascular disease (CVD) is the leading cause of death worldwide. Platelet-derived extracellular vesicles (PEV) have attracted extensive attention in cardiovascular disease research in recent years because their cargo is involved in a variety of pathophysiological processes, such as thrombosis, immune response, promotion or inhibition of inflammatory response, promotion of angiogenesis as well as cell proliferation and migration.

AREAS COVERED

This review explores the role of PEV in various cardiovascular diseases (such as atherosclerosis, myocardial infarction, ischemia-reperfusion injury, and heart failure), with relation to its molecular cargo (nucleic acids, bioactive lipids, proteins) and aims to provide new insights in the pathophysiologic role of PEV, and methods for preventing and treating cardiovascular diseases based on PEV.

EXPERT OPINION

Studies have shown that the cargo of PEV may be dysregulated during cardiovascular disease and delivery to tissues can result in detrimental pathophysiologic effects. Counteracting this process might have the potential to inhibit inflammation, promote angiogenesis, and inhibit cardiomyocyte death. In addition, PEV have potential as biocompatible and autologous drug carriers. Therefore, better research on the mechanisms how PEV act during cardiovascular disease and could be implemented as a therapeutic will provide new perspectives for the treatment of cardiovascular disease.

Advanced Imaging Techniques for Atherosclerosis and Cardiovascular Calcification in Animal Models

The detection and assessment of atherosclerosis and cardiovascular calcification can inform risk stratification and therapies to reduce cardiovascular morbidity and mortality. In this review, we provide an overview of current and emerging imaging techniques for assessing atherosclerosis and cardiovascular calcification in animal models. Traditional imaging modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI), offer non-invasive approaches of visualizing atherosclerotic calcification in vivo; integration of these techniques with positron emission tomography (PET) imaging adds molecular imaging capabilities, such as detection of metabolically active microcalcifications with 18F-sodium fluoride. Photoacoustic imaging provides high contrast that enables in vivo evaluation of plaque composition, yet this method is limited by optical penetration depth. Light-sheet fluorescence microscopy provides high-resolution, three-dimensional imaging of cardiovascular structures and has been used for ex vivo assessment of atherosclerotic calcification, but its limited tissue penetration and requisite complex sample preparation preclude its use in vivo to evaluate cardiac tissue. Overall, with these evolving imaging tools, our understanding of cardiovascular calcification development in animal models is improving, and the combination of traditional imaging techniques with emerging molecular imaging modalities will enhance our ability to investigate therapeutic strategies for atherosclerotic calcification.

Cannabis sativa extracts inhibit LDL oxidation and the formation of foam cells in vitro, acting as potential multi-step inhibitors of atherosclerosis development

Atherosclerotic disease is the leading cause of death world-wide. Our goal was to explore the effect of phytocannabinoids on the molecular mechanisms triggering the development of the atheromatous lesion. Three cannabis sativa extracts of different chemotypes were chemically characterized by UPLC-DAD. The capacity of the extracts to prevent the oxidation of LDL, the formation of foam cells and the activation of an inflammatory response by J774 cells, were monitored by UV-Vis spectrometry, confocal-microscopy and western blot. Three varieties of cannabis sativa, with high (E1), intermediate (E2) and low (E3) THC/CBD ratios were selected. The three cannabis extracts inhibited the oxidation of LDL by copper ions and the formation of foam cells by J774.1 cells challenged with oxLDL (ED50 5-12 μg mL-1). The effect of the cannabinoid extracts on the endocytic process was independent of the canonical cannabinoid receptors, CB1 and CB2, but related to the action of non-canonical receptors (TRPV1, TRPV4 and GPR55), involved in calcium signaling. Decreased levels of CD36 and OLR1 scavenger receptors were, at least partially, responsible for the diminished uptake of oxLDL induced by phytocannabinoids. The downregulation of CD36 and OLR1 could be explained by the observed inhibitory effect of the cannabis extracts on the activation of the NFκB pathway by oxLDL. Phytocannabinoids interfere with the main events leading to the development of the atheromatous plaque, opening new venues on atherosclerosis therapy.

Nanoparticle-based itaconate treatment recapitulates low-cholesterol/low-fat diet-induced atherosclerotic plaque resolution

Current pharmacologic treatments for atherosclerosis do not completely protect patients; additional protection can be achieved by dietary modifications, such as a low-cholesterol/low-fat diet (LCLFD), that mediate plaque stabilization and inflammation reduction. However, this lifestyle modification can be challenging for patients. Unfortunately, incomplete understanding of the underlying mechanisms has thwarted efforts to mimic the protective effects of a LCLFD. Here, we report that the tricarboxylic acid cycle intermediate itaconate (ITA), produced by plaque macrophages, is key to diet-induced plaque resolution. ITA is produced by immunoresponsive gene 1 (IRG1), which we observe is highly elevated in myeloid cells of vulnerable plaques and absent from early or stable plaques in mice and humans. We additionally report development of an ITA-conjugated lipid nanoparticle that accumulates in plaque and bone marrow myeloid cells, epigenetically reduces inflammation via H3K27ac deacetylation, and reproduces the therapeutic effects of LCLFD-induced plaque resolution in multiple atherosclerosis models.

Angiotensin II Induces Vascular Endothelial Dysfunction by Promoting Lipid Peroxidation-Mediated Ferroptosis via CD36

Angiotensin II (Ang II) is an effective vasoconstriction peptide, a major effector molecule of the renin-angiotensin-aldosterone system (RAAS) and one of the important causes of endothelial dysfunction. Ferroptosis is considered to be involved in the occurrence and development of cardiovascular diseases. This study is dedicated to exploring the role and mechanism of Ang II-induced ferroptosis in HUVECs and to finding molecular targets for vascular endothelial injury and dysfunction during the progression of hypertension. In this study, we found that with the increase in exposure concentration, the intracellular ROS content and apoptosis rate increased significantly, the NO release decreased significantly in the medium- and high-concentration groups and the ET-1 content in the high-concentration group increased significantly. The expression of ZO-1 protein was significantly decreased in the high-concentration group. The expression of p-eNOS, VE-cadherin and Occludin protein showed a dose-dependent downward trend, while the ICAM-1 protein showed an upward trend. Ang II caused lipid metabolism disorders in HUVECs, and the PL-PUFAs associated with ferroptosis were significantly increased. In addition, Ang II promoted a significant increase in intracellular free Fe2+ content and MDA and a significant decrease in GSH content. Furthermore, the expression of GPX4, SLC7A11 and SLC3A2 was down-regulated, the expression of ACSL4, LPCAT3 and ALOX15 was up-regulated, and the ratio of p-cPLA2/cPLA2 was increased. After the intervention of ferroptosis inhibitor Fer-1, the injury and dysfunction of HUVECs induced by Ang II were significantly rescued. Immunofluorescence results showed that the expression of CD36 showed a significant increasing trend and was localized in the cytoplasm. Over-expression of CD36 promoted Ang II-induced ferroptosis and endothelial dysfunction. In conclusion, Ang II induces the injury of HUVECs, decreases vascular diastole and endothelial barrier-related molecules, and increases vascular constriction and adhesion-related molecules, which may be related to CD36 and its mediated lipid peroxidation and ferroptosis signals.

Monocyte CD36 Expression Predicts Disease Activity in Patients With Crohn's Disease

Background: Crohn's disease (CD) is a chronic intestinal inflammatory disease associated with genetic, environmental, and other unknown factors. Cluster of differentiation 36 (CD36) plays an important role in cancer, inflammation, and metabolic diseases. Although CD36 has recently been implicated in various diseases, its role in CD is still unclear. Methods: Blood samples were collected from patients with CD and healthy volunteers. Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient centrifugation over Ficoll-Paque and labeled with monoclonal antibodies (CD14-APC and CD36-PE). Flow cytometer CytoFlex is used for analysis. Results: Twenty-nine patients with CD in remission, 42 patients with active CD, and 23 healthy volunteers were included in the study. Our results showed that the frequency of the CD14+CD36+ monocyte subset was increased in PBMCs from patients with active CD compared with patients in remission and healthy controls. However, CD36 on monocytes was lower in CD compared with the healthy controls. CD36 expression was decreased in patients with active CD compared with that of patients with CD in remission and healthy control subjects, but no difference was found between patients with CD in remission and healthy controls. Interestingly, we found negative correlations of CD36 with HBI, SES-CD, C-reactive protein, and neutrophil-to-lymphocyte ratio. Conclusions: These data indicate that monocyte CD36 associates with disease activity in CD and might be a potential biomarker for assessing the activity of CD.

Unveiling impaired vascular function and cellular heterogeneity in diabetic donor-derived vascular organoids

Vascular organoids (VOs), derived from induced pluripotent stem cells (iPSCs), hold promise as in vitro disease models and drug screening platforms. However, their ability to faithfully recapitulate human vascular disease and cellular composition remains unclear. In this study, we demonstrate that VOs derived from iPSCs of donors with diabetes (DB-VOs) exhibit impaired vascular function compared to non-diabetic VOs (ND-VOs). DB-VOs display elevated levels of reactive oxygen species (ROS), heightened mitochondrial content and activity, increased proinflammatory cytokines, and reduced blood perfusion recovery in vivo. Through comprehensive single-cell RNA sequencing, we uncover molecular and functional differences, as well as signaling networks, between vascular cell types and clusters within DB-VOs. Our analysis identifies major vascular cell types (endothelial cells [ECs], pericytes, and vascular smooth muscle cells) within VOs, highlighting the dichotomy between ECs and mural cells. We also demonstrate the potential need for additional inductions using organ-specific differentiation factors to promote organ-specific identity in VOs. Furthermore, we observe basal heterogeneity within VOs and significant differences between DB-VOs and ND-VOs. Notably, we identify a subpopulation of ECs specific to DB-VOs, showing overrepresentation in the ROS pathway and underrepresentation in the angiogenesis hallmark, indicating signs of aberrant angiogenesis in diabetes. Our findings underscore the potential of VOs for modeling diabetic vasculopathy, emphasize the importance of investigating cellular heterogeneity within VOs for disease modeling and drug discovery, and provide evidence of GAP43 (neuromodulin) expression in ECs, particularly in DB-VOs, with implications for vascular development and disease.

Investigating the anti-inflammatory effects of icariin: A combined meta-analysis and machine learning study

Objective

The objectives of this study were to define the superiority of icariin and its derivatives' anti-inflammatory activities and to create a reference framework for evaluating preclinical evidence. This method combines machine learning and meta-analysis to identify underlying biological pathways.

Methods

Data came from PubMed, Embase, Web of Science, and the Cochrane Library. SYRCLE was used to evaluate the risk of bias in a subset of research. Meta-analysis and detailed subgroup analyses, categorized by species, genders, disease type, dosage, and treatment duration, were performed using R and STATA 15.0 software to derive nuanced insights. Employing R software (version 4.2.3) and the tidymodels package, the analysis focused on constructing a model and selecting features, with TNF-α as the dependent variable. This approach aims to identify significant predictors of drug efficacy. An in-depth literature facilitated the synthesis of anti-inflammatory mechanisms attributed to icariin and its constituent compounds.

Results

Following a meticulous search and selection process, 19 studies, involving 370 and 260 animals were included in the meta-analysis and machine-learning assessment, respectively. The findings revealed that icariin and its derivatives markedly reduced inflammation markers, including TNF-α and IL-1β. Additionally, machine-learning outcomes, with TNF-α as the target variable, indicated enhanced anti-inflammatory effects of icariin across respiratory, urological, neurological, and digestive disease types. These effects were more pronounced at doses exceeding 27.52 mg/kg/day and treatment durations beyond 31.22 days.

Conclusion

Strong anti-inflammatory effects are exhibited by icariiin and its derivatives, which are especially beneficial in the management of digestive, neurological, pulmonary, and urinary conditions. Effective for periods longer than 31.22 days and at dosages more than 27.52 mg/kg/day. Subsequent research will involve more targeted animal experiments and safety assessments to obtain more comprehensive preclinical evidence.

Qilong capsule prevents myocardial ischemia/reperfusion injury by inhibiting platelet activation via the platelet CD36 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Qilong capsule (QC) is developed from the traditional Chinese medicine formula Buyang Huanwu Decoction, which has been clinically used to invigorate Qi and promote blood circulation to eliminate blood stasis. Myocardial ischemia‒reperfusion injury (MIRI) can be attributed to Qi deficiency and blood stasis. However, the effects of QC on MIRI remain unclear.

AIM OF THE STUDY

This study aimed to investigate the protective effect and possible mechanism of QC on platelet function in MIRI rats.

MATERIALS AND METHODS

The left anterior descending artery of adult Sprague‒Dawley rats was ligated for 30 min and then reperfused for 120 min with or without QC treatment. Then, the whole blood viscosity, plasma viscosity, coagulation, platelet adhesion rate, platelet aggregation, and platelet release factors were evaluated. Platelet CD36 and its downstream signaling pathway-related proteins were detected by western blotting. Furthermore, the active components of QC and the molecular mechanism by which QC regulates platelet function were assessed via molecular docking, platelet aggregation tests in vitro and BLI analysis.

RESULTS

We found that QC significantly reduced the whole blood viscosity, plasma viscosity, platelet adhesion rate, and platelet aggregation induced by ADP or AA in rats with MIRI. The inhibition of platelet activation by QC was associated with reduced levels of β-TG, PF-4, P-selectin and PAF. Mechanistically, QC effectively attenuated the expression of platelet CD36 and thus inhibited the activation of Src, ERK5, and p38. The active components of QC apparently suppressed platelet aggregation in vitro and regulated the CD36 signaling pathway.

CONCLUSIONS

QC improves MIRI-induced hemorheological disorders, which might be partly attributed to the inhibition of platelet activation via CD36-mediated platelet signaling pathways.

Mechanism of efferocytosis in atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory vascular disease that occurs in the intima of large and medium-sized arteries with the immune system's involvement. It is a common pathological basis for high morbidity and mortality of cardiovascular diseases. Abnormal proliferation of apoptotic cells and necrotic cells leads to AS plaque expansion, necrotic core formation, and rupture. In the early stage of AS, macrophages exert an efferocytosis effect to engulf and degrade apoptotic, dead, damaged, or senescent cells by efferocytosis, thus enabling the regulation of the organism. In the early stage of AS, macrophages rely on this effect to slow down the process of AS. However, in the advanced stage of AS, the efferocytosis of macrophages within the plaque is impaired, which leads to the inability of macrophages to promptly remove the apoptotic cells (ACs) from the organism promptly, causing exacerbation of AS. Moreover, upregulation of CD47 expression in AS plaques also protects ACs from phagocytosis by macrophages, resulting in a large amount of residual ACs in the plaque, further expanding the necrotic core. In this review, we discussed the molecular mechanisms involved in the process of efferocytosis and how efferocytosis is impaired and regulated during AS, hoping to provide new insights for treating AS.

Visceral adipose of obese mice inhibits endothelial inwardly rectifying K+ channels in a CD36-dependent fashion

Obesity imposes deficits on adipose tissue and vascular endothelium, yet the role that distinct adipose depots play in mediating endothelial dysfunction in local arteries remains unresolved. We recently showed that obesity impairs endothelial Kir2.1 channels, mediators of nitric oxide production, in arteries of visceral adipose tissue (VAT), while Kir2.1 function in subcutaneous adipose tissue (SAT) endothelium remains intact. Therefore, we determined if VAT versus SAT from lean or diet-induced obese mice affected Kir2.1 channel function in vitro. We found that VAT from obese mice reduces Kir2.1 function without altering channel expression whereas AT from lean mice and SAT from obese mice had no effect on Kir2.1 function as compared to untreated control cells. As Kir2.1 is well known to be inhibited by fatty acid derivatives and obesity is strongly associated with elevated circulating fatty acids, we next tested the role of the fatty acid translocase CD36 in mediating VAT-induced Kir2.1 dysfunction. We found that the downregulation of CD36 restored Kir2.1 currents in endothelial cells exposed to VAT from obese mice. In addition, endothelial cells exposed to VAT from obese mice exhibited a significant increase in CD36-mediated fatty acid uptake. The importance of CD36 in obesity-induced endothelial dysfunction of VAT arteries was further supported in ex vivo pressure myography studies where CD36 ablation rescued the endothelium-dependent response to flow via restoring Kir2.1 and endothelial nitric oxide synthase function. These findings provide new insight into the role of VAT in mediating obesity-induced endothelial dysfunction and suggest a novel role for CD36 as a mediator of endothelial Kir2.1 impairment.NEW & NOTEWORTHY Our findings suggest a role for visceral adipose tissue (VAT) in the dysfunction of endothelial Kir2.1 in obesity. We further reveal a role for CD36 as a major contributor to VAT-mediated Kir2.1 and endothelial dysfunction, suggesting that CD36 offers a potential target for preventing the early development of obesity-associated cardiovascular disease.

CD36 as a gatekeeper of myocardial lipid metabolism and therapeutic target for metabolic disease

The multifunctional membrane glycoprotein CD36 is expressed in different types of cells and plays a key regulatory role in cellular lipid metabolism, especially in cardiac muscle. CD36 facilitates the cellular uptake of long-chain fatty acids, mediates lipid signaling, and regulates storage and oxidation of lipids in various tissues with active lipid metabolism. CD36 deficiency leads to marked impairments in peripheral lipid metabolism, which consequently impact on the cellular utilization of multiple different fuels because of the integrated nature of metabolism. The functional presence of CD36 at the plasma membrane is regulated by its reversible subcellular recycling from and to endosomes and is under the control of mechanical, hormonal, and nutritional factors. Aberrations in this dynamic role of CD36 are causally associated with various metabolic diseases, in particular insulin resistance, diabetic cardiomyopathy, and cardiac hypertrophy. Recent research in cardiac muscle has disclosed the endosomal proton pump vacuolar-type H+-ATPase (v-ATPase) as a key enzyme regulating subcellular CD36 recycling and being the site of interaction between various substrates to determine cellular substrate preference. In addition, evidence is accumulating that interventions targeting CD36 directly or modulating its subcellular recycling are effective for the treatment of metabolic diseases. In conclusion, subcellular CD36 localization is the major adaptive regulator of cellular uptake and metabolism of long-chain fatty acids and appears a suitable target for metabolic modulation therapy to mend failing hearts.

RFX1 regulates foam cell formation and atherosclerosis by mediating CD36 expression

BACKGROUND AND AIMS

Atherosclerosis (AS) is a continuously low-grade inflammatory disease, and monocyte-derived macrophages play a vital role in AS pathogenesis. Regulatory factor X1 (RFX1) has been reported to participate in differentiation of various cells. Our previous report showed that RFX1 expression in CD14+ monocytes from AS patients was decreased and closely related to AS development. Macrophages mostly derive from monocytes and play an important role in AS plaque formation and stability. However, the functions of RFX1 in the formation of macrophage-derived foam cells and consequent AS development are unclear.

METHODS

We explored the effects of RFX1 on oxidation low lipoprotein (ox-LDL)-stimulated foam cell formation and CD36 expression by increasing or silencing Rfx1 expression in mouse peritoneal macrophages (PMAs). The ApoE-/-Rfx1f/f or ApoE-/-Rfx1f/f Lyz2-Cre mice fed a high-fat diet for 24 weeks were used to further examine the effect of RFX1 on AS pathogenesis. We then performed dual luciferase reporter assays to study the regulation of RFX1 for CD36 transcription.

RESULTS

Our results demonstrate that RFX1 expression was significantly reduced in ox-LDL induced foam cells and negatively correlated with lipid uptake in macrophages. Besides, Rfx1 deficiency in myeloid cells aggravated atherosclerotic lesions in ApoE-/- mice. Mechanistically, RFX1 inhibited CD36 expression by directly regulating CD36 transcription in macrophages.

CONCLUSIONS

The reduction of RFX1 expression in macrophages is a vital determinant for foam cell formation and the initiation of AS, proving a potential novel approach for the treatment of AS disease.

CD36 regulates macrophage and endothelial cell activation and multinucleate giant cell formation in anti neutrophil cytoplasm antibody vasculitis

OBJECTIVE

To investigate CD36 in ANCA-associated vasculitis (AAV), a condition characterized by monocyte/macrophage activation and vascular damage.

METHODS

CD36 expression was assessed in AAV patients and healthy controls (HC). The impact of palmitic acid (PA) stimulation on multinucleate giant cell (MNGC) formation, macrophage, and endothelial cell activation, with or without CD36 knockdown, was examined.

RESULTS

CD36 was overexpressed on AAV patients' monocytes compared to HC, regardless of disease activity. AAV patients exhibited elevated soluble CD36 levels in serum and plasma and PR3-ANCA patients' monocytes demonstrated increased MNGC formation following PA stimulation compared to HC. PA stimulation of macrophages or endothelial cells resulted in heightened CD36 expression, cell activation, increased macrophage migration inhibitory factor (MIF) production, and c-Myc expression, with attenuation upon CD36 knockdown.

CONCLUSION

CD36 participates in macrophage and endothelial cell activation and MNGC formation, features of AAV pathogenesis. AAV treatment may involve targeting CD36 or MIF.

The regulatory role of CD36 in hematopoiesis beyond fatty acid uptake

CD36 is a transmembrane glycoprotein, located on surface of numerous cell types. This review is aimed to explore regulatory role of CD36 in hematopoiesis beyond fatty acid uptake. CD36 acts as a pattern recognition receptor, regulates cellular fatty acid homeostasis, and negatively monitors angiogenesis. CD36 also mediates free fatty acid transportation to hematopoietic stem cells in response to infections. During normal physiology and pathophysiology, CD36 significantly participates in the activation and metabolic needs of platelets, macrophages, monocytes, T cells, B cells, and dendritic cells. CD36 has shown a unique relationship with Plasmodium falciparum-infected erythrocytes (PfIEs) as a beneficiary for both parasite and host. CD36 actively participates in pathogenesis of various hematological cancers as a significant prognostic biomarker including AML, HL, and NHL. CD36-targeting antibodies, CD36 antagonists (small molecules), and CD36 expression inhibitors/modulators are used to target CD36, depicting its therapeutic potential. Many preclinical studies or clinical trials were performed to assess CD36 as a therapeutic target; some are still under investigation. This review reflects the role of CD36 in hematopoiesis which requires more consideration in future research.

Reactive Carbonyl Species and Protein Lipoxidation in Atherogenesis

Atherosclerosis is a multifactorial disease of medium and large arteries, characterized by the presence of lipid-rich plaques lining the intima over time. It is the main cause of cardiovascular diseases and death worldwide. Redox imbalance and lipid peroxidation could play key roles in atherosclerosis by promoting a bundle of responses, including endothelial activation, inflammation, and foam cell formation. The oxidation of polyunsaturated fatty acids generates various lipid oxidation products such as reactive carbonyl species (RCS), including 4-hydroxy alkenals, malondialdehyde, and acrolein. RCS covalently bind to nucleophilic groups of nucleic acids, phospholipids, and proteins, modifying their structure and activity and leading to their progressive dysfunction. Protein lipoxidation is the non-enzymatic post-translational modification of proteins by RCS. Low-density lipoprotein (LDL) oxidation and apolipoprotein B (apoB) modification by RCS play a major role in foam cell formation. Moreover, oxidized LDLs are a source of RCS, which form adducts on a huge number of proteins, depending on oxidative stress intensity, the nature of targets, and the availability of detoxifying systems. Many systems are affected by lipoxidation, including extracellular matrix components, membranes, cytoplasmic and cytoskeletal proteins, transcription factors, and other components. The mechanisms involved in lipoxidation-induced vascular dysfunction are not fully elucidated. In this review, we focus on protein lipoxidation during atherogenesis.

Interactions between macrophage membrane and lipid mediators during cardiovascular diseases with the implications of scavenger receptors

The onset and progression of cardiovascular diseases with the major underlying cause being atherosclerosis, occur during chronic inflammatory persistence in the vascular system, especially within the arterial wall. Such prolonged maladaptive inflammation is driven by macrophages and their key mediators are generally attributed to a disparity in lipid metabolism. Macrophages are the primary cells of innate immunity, endowed with expansive membrane domains involved in immune responses with their signalling systems. During atherosclerosis, the membrane domains and receptors control various active organisations of macrophages. Their scavenger/endocytic receptors regulate the trafficking of intracellular and extracellular cargo. Corresponding influence on lipid metabolism is mediated by their dynamic interaction with scavenger membrane receptors and their integrated mechanisms such as pinocytosis, phagocytosis, cholesterol export/import, etc. This interaction not only results in the functional differentiation of macrophages but also modifies their structural configurations. Here, we reviewed the association of macrophage membrane biomechanics and their scavenger receptor families with lipid metabolites during the event of atherogenesis. In addition, the membrane structure of macrophages and the signalling pathways involved in endocytosis integrated with lipid metabolism are detailed. This article establishes future insights into the scavenger receptors as potential targets for cardiovascular disease prevention and treatment.

Is the suppression of CD36 a promising way for atherosclerosis therapy?

Atherosclerosis is the main underlying pathology of many cardiovascular diseases and is marked by plaque formation in the artery wall. It has posed a serious threat to the health of people all over the world. CD36 acts as a significant regulator of lipid homeostasis, which is closely associated with the onset and progression of atherosclerosis and may be a new therapeutic target. The abnormal overexpression of CD36 facilitates lipid accumulation, foam cell formation, inflammation, endothelial apoptosis, and thrombosis. Numerous natural products and lipid-lowering agents are found to target the suppression of CD36 or inhibit the upregulation of CD36 to prevent and treat atherosclerosis. Here, the structure, expression regulation and function of CD36 in atherosclerosis and its related pharmacological therapies are reviewed. This review highlights the importance of drugs targeting CD36 suppression in the treatment and prevention of atherosclerosis, in order to develop new therapeutic strategies and potential anti-atherosclerotic drugs both preclinically and clinically.

Plasma levels of CD36 and glutathione as biomarkers for ruptured intracranial aneurysm

Evidence has proved that intracranial aneurysm (IA) formation and rupture might be closely related to inflammatory response and oxidative stress. Our objective was to evaluate the potential of CD36 and glutathione (GSH) as biomarkers for IA. In this study, the enzyme-linked immunosorbent assay was used to measure the plasma levels of CD36 and GSH in 30 IA patients and 30 healthy controls. Then, correlation analysis, receiver operating characteristic (ROC) curve, and logistic regression analysis were performed. The results showed that the plasma level of CD36 in IA patients was significantly higher than that in the control group (P < 0.0001), and plasma GSH was significantly lower compared with that in the control group (P < 0.0001). ROC analysis showed that CD36 and GSH had high sensitivity (90.0 and 96.6%) and specificity (96.6 and 86.6%) for IA diagnosis. The combined sensitivity and specificity achieved were 100 and 100%, respectively. The plasma levels of CD36 and GSH did not show a significant correlation with age, the Glasgow Coma Scale, Hunter-Hess score, aneurysm size, aneurysm height, aneurysm neck, and aspect ratio. The AUC of the logistic regression model based on CD36 and GSH was 0.505. Our results suggested that the combination of plasma CD36 and GSH could serve as potential biomarkers for IA rupture.

Prediction and validation of common targets in atherosclerosis and non-small cell lung cancer influenced by atorvastatin

BACKGROUND

Cardiovascular disease and cancer are the main causes of morbidity and mortality worldwide. Studies have shown that these two diseases may have some common risk factors. Atorvastatin is mainly used for the treatment of atherosclerosis in clinic. A large number of studies show that atorvastatin may produce anti-tumor activities. This study aimed to predict the common targets of atorvastatin against atherosclerosis and non-small cell lung cancer (NSCLC) based on network pharmacology.

METHODS

The target genes of atherosclerosis and NSCLC were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. The disease-target-component model map and the core network were obtained using Cytoscape 3.7.1. The MTS and wound healing assay were used to detect the effect of atorvastatin on cell viability and migration of A549 cells. The expression of potential common target genes of atorvastatin against atherosclerosis and NSCLC were confirmed in A549 cells and lung cancer tissues of patients.

RESULTS

We identified 15 identical pathogenic genes, and four of which (MMP9, MMP12, CD36, and FABP4) were considered as the key target genes of atorvastatin in anti-atherosclerosis and NSCLC. The MTS and wound healing assays revealed that atorvastatin decreased A549 cells migration significantly. Atorvastatin markedly decreased the expression of MMP9, MMP12, CD36, and FABP4 in A549 cells and patients were treated with atorvastatin.

CONCLUSIONS

This study demonstrated 15 common pathogenic genes in both atherosclerosis and NSCLC. And verified that MMP 9, MMP 12, CD 36 and FABP 4 might be the common target genes of atorvastatin in anti-atherosclerosis and NSCLC.

Reversal of fibrosis and portal hypertension by Empagliflozin treatment of CCl4-induced liver fibrosis: Emphasis on gal-1/NRP-1/TGF-β and gal-1/NRP-1/VEGFR2 pathways

To date, liver fibrosis has no clinically approved treatment. Empagliflozin (EMPA), a highly selective sodium-glucose-cotransporter-2 (SGLT2) inhibitor, has shown ameliorative potential in liver diseases without revealing its full mechanisms. Neuropilin-1 (NRP-1) is a novel regulator of profibrogenic signaling pathways related to hepatic stellate cells (HSCs) and hepatic sinusoidal endothelial cells (HSECs) that modulates intrahepatic profibrogenic and angiogenic pathways. Herein, EMPA's antifibrotic potentials and effects on galactin-1 (Gal-1)/NRP-1 signaling pathways have been evaluated in an experimental liver fibrosis rat model by testing different EMPA dose regimens. EMPA treatment brought a dose-dependent decrease in Gal-1/NRP-1 hepatic expression. This was coupled with suppression of major HSCs pro-fibrotic pathways; transforming growth factor-β (TGF-β)/TGF-βRI/Smad2 and platelet-derived growth factor-beta (PDGF-β) with a diminution of hepatic Col 1A1 level. In addition, EMPA prompted a protuberant suppression of the angiogenic pathway; vascular endothelial growth factor (VEGF)/VEGF-receptor-2 (VEGFR-2)/SH2-Domain Containing Adaptor Protein-B (Shb), and reversal of altered portal hypertension (PHT) markers; endothelin-1 (ET-1) and endothelial nitric oxide synthase (eNOS). The amelioration of liver fibrosis was coupled with a remarkable improvement in liver aminotransferases and histologic hepatic fibrosis Ishak scores. The highest EMPA dose showed a good safety profile with minimal changes in renal function and glycemic control. Thus, the current study brought about novel findings for a potential liver fibrosis treatment modality via targeting NRP-1 signaling pathways by EMPA.

Short-chain fatty acids are potential goalkeepers of atherosclerosis

Short-chain fatty acids (SCFAs) are metabolites produced by gut bacteria and play a crucial role in various inflammatory diseases. Increasing evidence suggests that SCFAs can improve the occurrence and progression of atherosclerosis. However, the molecular mechanisms through which SCFAs regulate the development of atherosclerosis have not been fully elucidated. This review provides an overview of the research progress on SCFAs regarding their impact on the risk factors and pathogenesis associated with atherosclerosis, with a specific focus on their interactions with the endothelium and immune cells. These interactions encompass the inflammation and oxidative stress of endothelial cells, the migration of monocytes/macrophages, the lipid metabolism of macrophages, the proliferation and migration of smooth muscle cells, and the proliferation and differentiation of Treg cells. Nevertheless, the current body of research is insufficient to comprehensively understand the full spectrum of SCFAs' mechanisms of action. Therefore, further in-depth investigations are imperative to establish a solid theoretical foundation for the development of clinical therapeutics in this context.

SGLT2 Inhibitors in Aging-Related Cardiovascular Disease: A Review of Potential Mechanisms

Population aging combined with higher susceptibility to cardiovascular diseases in older adults is increasing the incidence of conditions such as atherosclerosis, myocardial infarction, heart failure, myocardial hypertrophy, myocardial fibrosis, arrhythmia, and hypertension. sodium-glucose cotransporter 2 inhibitors (SGLT2i) were originally developed as a novel oral drug for patients with type 2 diabetes mellitus. Unexpectedly, recent studies have shown that, beyond their effect on hyperglycemia, SGLT2i also have a variety of beneficial effects on cardiovascular disease. Experimental models of cardiovascular disease have shown that SGLT2i ameliorate the process of aging-related cardiovascular disease by inhibiting inflammation, reducing oxidative stress, and reversing endothelial dysfunction. In this review, we discuss the role of SGLT2i in aging-related cardiovascular disease and propose the use of SGLT2i to prevent and treat these conditions in older adults.

Molecular Drug Simulation and Experimental Validation of the CD36 Receptor Competitively Binding to Long-Chain Fatty Acids by 7-Ketocholesteryl-9-carboxynonanoate

Long-chain fatty acids (LCFAs) are one of the main energy-supplying substances in the body. LCFAs with different lengths and saturations may have contrasting biological effects that exacerbate or alleviate progress against a variety of systemic disorders of lipid metabolism in organisms. Nonalcoholic fatty liver disease is characterized by chronic inflammation and steatosis, mainly caused by the ectopic accumulation of lipids in the liver, especially LCFAs. CD36 is a scavenger receptor that recognizes and mediates the transmembrane absorption of LCFAs and is expressed in a variety of cells throughout the body. In previous studies, our group found that 7-ketocholesteryl-9-carboxynonanoate (oxLig-1) has the biological effect of targeting CD36 to inhibit oxidized low-density lipoprotein lipotoxicity-induced lipid metabolism disorder; it has an ω-carboxyl physiologically active center and is structurally similar to LCFAs. However, the biological mechanism of oxLig-1 binding to CD36 and competing for binding to different types of LCFAs is still not clear. In this study, molecular docking and molecular dynamics simulation were utilized to simulate and analyze the binding activity between oxLig-1 and different types of LCFAs to CD36 and confirmed by the enzyme-linked immunosorbent assay (ELISA) method. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) platform was applied to predict the drug-forming properties of oxLig-1, and HepG2 cells model of oleic acid and nonalcoholic fatty liver disease (NAFLD) model mice were validated to verify the biological protection of oxLig-1 on lipid lowering. The results showed that there was a co-binding site of LCFAs and oxLig-1 on CD36, and the binding driving forces were mainly hydrogen bonding and hydrophobic interactions. The binding abilities of polyunsaturated LCFAs, oxLig-1, monounsaturated LCFAs, and saturated LCFAs to CD36 showed a decreasing trend in this order. There was a similar decreasing trend in the stability of the molecular dynamics simulation. ELISA results similarly confirmed that the binding activity of oxLig-1 to CD36 was significantly higher than that of typical monounsaturated and saturated LCFAs. ADMET prediction results indicated that oxLig-1 had a good drug-forming property. HepG2 cells model of oleic acid and NAFLD model mice study results demonstrated the favorable lipid-lowering biological effects of oxLig-1. Therefore, oxLig-1 may have a protective effect by targeting CD36 to inhibit the excessive influx and deposition of lipotoxicity monounsaturated LCFAs and saturated LCFAs in hepatocytes.

Injectable liposomal docosahexaenoic acid alleviates atherosclerosis progression and enhances plaque stability

Atherosclerosis is a chronic inflammatory vascular disease that is characterized by the accumulation of lipids and immune cells in plaques built up inside artery walls. Docosahexaenoic acid (DHA, 22:6n-3), an omega-3 polyunsaturated fatty acid (PUFA), which exerts anti-inflammatory and antioxidant properties, has long been purported to be of therapeutic benefit to atherosclerosis patients. However, large clinical trials have yielded inconsistent data, likely due to variations in the formulation, dosage, and bioavailability of DHA following oral intake. To fully exploit its potential therapeutic effects, we have developed an injectable liposomal DHA formulation intended for intravenous administration as a plaque-targeted nanomedicine. The liposomal formulation protects DHA against chemical degradation and increases its local concentration within atherosclerotic lesions. Mechanistically, DHA liposomes are readily phagocytosed by activated macrophages, exert potent anti-inflammatory and antioxidant effects, and inhibit foam cell formation. Upon intravenous administration, DHA liposomes accumulate preferentially in atherosclerotic lesional macrophages and promote polarization of macrophages towards an anti-inflammatory M2 phenotype, resulting in attenuation of atherosclerosis progression in both ApoE-/- and Ldlr-/- experimental models. Plaque composition analysis demonstrates that liposomal DHA inhibits macrophage infiltration, reduces lipid deposition, and increases collagen content, thus improving the stability of atherosclerotic plaques against rupture. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) further reveals that DHA liposomes can partly restore the complex lipid profile of the plaques to that of early-stage plaques. In conclusion, DHA liposomes offer a promising approach for applying DHA to stabilize atherosclerotic plaques and attenuate atherosclerosis progression, thereby preventing atherosclerosis-related cardiovascular events.

Identification of lipid metabolism-related biomarkers for diagnosis and molecular classification of atherosclerosis

BACKGROUND

Atherosclerosis is now the main cause of cardiac-cerebral vascular diseases around the world. Disturbances in lipid metabolism have an essential role in the development and progression of atherosclerosis. Thus, we aimed to investigate lipid metabolism-related molecular clusters and develop a diagnostic model for atherosclerosis.

METHODS

First, we used the GSE100927 and GSE43292 datasets to screen differentially expressed lipid metabolism-related genes (LMRGs). Subsequent enrichment analysis of these key genes was performed using the Metascape database. Using 101 atherosclerosis samples, we investigated the LMRG-based molecular clusters and the corresponding immune cell infiltration. After that, a diagnostic model for atherosclerosis was constructed using the least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression. Finally, a series of bioinformatics techniques, including CIBERSORT, gene set variation analysis, and single-cell data analysis, were used to analyze the potential mechanisms of the model genes in atherosclerosis.

RESULTS

A total of 29 LMRGs were found to be differentially expressed between atherosclerosis and normal samples. Functional and DisGeNET enrichment analyses indicated that 29 LMRGs are primarily engaged in cholesterol and lipid metabolism, the PPAR signaling pathway, and regulation of the inflammatory response and are also closely associated with atherosclerotic lesions. Two LMRG-related molecular clusters with significant biological functional differences are defined in atherosclerosis. A three-gene diagnostic model containing ADCY7, SCD, and CD36 was subsequently constructed. Receiver operating characteristic curves, decision curves, and an external validation dataset showed that our model exhibits good predictive performance. In addition, three model genes were found to be closely associated with immune cell infiltration, especially macrophage infiltration.

CONCLUSIONS

Our study comprehensively highlighted the intricate association between lipid metabolism and atherosclerosis and created a three-gene model for future clinical diagnosis.

TREM2 promotes cholesterol uptake and foam cell formation in atherosclerosis

Disordered lipid accumulation in the arterial wall is a hallmark of atherosclerosis. Previous studies found that the expression of triggering receptor expressed on myeloid cells 2 (TREM2), a transmembrane receptor of the immunoglobulin family, is increased in mouse atherosclerotic aortic plaques. However, it remains unknown whether TREM2 plays a role in atherosclerosis. Here we investigated the role of TREM2 in atherosclerosis using ApoE knockout (ApoE-/-) mouse models, primary vascular smooth muscle cells (SMCs), and bone marrow-derived macrophages (BMDMs). In ApoE-/- mice, the density of TREM2-positive foam cells in aortic plaques increased in a time-dependent manner after the mice were fed a high-fat diet (HFD). Compared with ApoE-/- mice, the Trem2-/-/ApoE-/- double-knockout mice showed significantly reduced atherosclerotic lesion size, foam cell number, and lipid burden degree in plaques after HFD feeding. Overexpression of TREM2 in cultured vascular SMCs and macrophages exacerbates lipid influx and foam cell formation by upregulating the expression of the scavenger receptor CD36. Mechanistically, TREM2 inhibits the phosphorylation of p38 mitogen-activated protein kinase and peroxisome proliferator activated-receptor gamma (PPARγ), thereby increasing PPARγ nuclear transcriptional activity and subsequently promoting the transcription of CD36. Our results indicate that TREM2 exacerbates atherosclerosis development by promoting SMC- and macrophage-derived foam cell formation by regulating scavenger receptor CD36 expression. Thus, TREM2 may act as a novel therapeutic target for the treatment of atherosclerosis.

The role of systemic inflammation and oxidative stress in the association of particulate air pollution metal content and early cardiovascular damage: A panel study in healthy college students

Exposure to fine particulate matter (PM_2.5) has been associated with adverse cardiovascular outcomes. However, the effects of toxic metals in PM_2.5 on cardiovascular health remain unknown. To investigate the early cardiovascular effects of specific PM_2.5 metal constituents at the personal level, we conducted a panel study on 45 healthy college students in Caofeidian, China. Personal exposure concentrations and cardiovascular effect markers were monitored simultaneously within one year in four study periods. Four linear mixed-effects models were used to analyze the relationship between personal exposure to PM_2.5 and 15 metal fractions (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, and Pb) with soluble CD36 (sCD36), C-reactive protein (CRP), and oxidized low-density lipoprotein (OX-LDL) levels, heart rate, and blood pressure. The concentrations of most individual metals (Mn, Cu, Zn, As, Se, Mo, Cd, Sb and Pb) were the highest in winter. Meanwhile, there were significant differences in inflammatory (sCD36 and CRP) and oxidative stress (OX-LDL) markers in the serum of participants over the four seasons. In particular, the estimated effects of personal metal exposure (such as V, As, Se, Cd, and Pb) on sCD36 and pulse pressure (PP) levels were consistently significant across the four LME models. A significant mediating role of sCD36 was also found in the relationship between personal exposure to Zn and Cr and changes in PP levels. Our findings provide clues and potential mechanisms regarding the cardiovascular effects of specific toxic constituents of PM_2.5 in healthy young adults.

Insights into SGLT2 inhibitor treatment of diabetic cardiomyopathy: focus on the mechanisms

Among the complications of diabetes, cardiovascular events and cardiac insufficiency are considered two of the most important causes of death. Experimental and clinical evidence supports the effectiveness of SGLT2i for improving cardiac dysfunction. SGLT2i treatment benefits metabolism, microcirculation, mitochondrial function, fibrosis, oxidative stress, endoplasmic reticulum stress, programmed cell death, autophagy, and the intestinal flora, which are involved in diabetic cardiomyopathy. This review summarizes the current knowledge of the mechanisms of SGLT2i for the treatment of diabetic cardiomyopathy.

Mechanism of oxidized phospholipid-related inflammatory response in vascular ageing

Vascular ageing is an important factor in the morbidity and mortality of the elderly. Atherosclerosis is a characteristic disease of vascular ageing, which is closely related to the enhancement of vascular inflammation. Phospholipid oxidation products are important factors in inducing cellular inflammation. Through interactions with vascular cells and immune cells, they regulate intracellular signaling pathways, activate the expression of various cytokines, and affect cell behavior, such as metabolic level, proliferation, apoptosis, etc. Intervention in lipid metabolism and anti-inflammation are the two key pathways of drugs for the treatment of atherosclerosis. This review aims to sort out the signaling pathway of oxidized phospholipids-induced inflammatory factors in vascular cells and immune cells and the mechanism leading to changes in cell behavior, and summarize the therapeutic targets in the inflammatory signaling pathway for the development of atherosclerosis drugs.

Genetic Markers of Insulin Resistance and Atherosclerosis in Type 2 Diabetes Mellitus Patients with Coronary Artery Disease

Type 2 diabetes mellitus (T2DM) is characterized by impaired insulin secretion on a background of insulin resistance (IR). IR and T2DM are associated with atherosclerotic coronary artery disease (CAD). The mechanisms of IR and atherosclerosis are known to share similar genetic and environmental roots. Endothelial dysfunction (ED) detected at the earliest stages of IR might be the origin of atherosclerosis progression. ED influences the secretion of pro-inflammatory cytokines and their encoding genes. The genes and their single nucleotide polymorphisms (SNPs) act as potential genetic markers of IR and atherosclerosis. This review focuses on the link between IR, T2DM, atherosclerosis, CAD, and the potential genetic markers CHI3L1, CD36, LEPR, RETN, IL-18, RBP-4, and RARRES2 genes.

Initial and ongoing tobacco smoking elicits vascular damage and distinct inflammatory response linked to neurodegeneration

Tobacco smoking is strongly linked to vascular damage contributing to the development of hypertension, atherosclerosis, as well as increasing the risk for neurodegeneration. Still, the involvement of the innate immune system in the development of vascular damage upon chronic tobacco use before the onset of clinical symptoms is not fully characterized. Our data provide evidence that a single acute exposure to tobacco elicits the secretion of extracellular vesicles expressing CD105 and CD49e from endothelial cells, granting further recognition of early preclinical biomarkers of vascular damage. Furthermore, we investigated the effects of smoking on the immune system of healthy asymptomatic chronic smokers compared to never-smokers, focusing on the innate immune system. Our data reveal a distinct immune landscape representative for early stages of vascular damage in clinically asymptomatic chronic smokers, before tobacco smoking related diseases develop. These results indicate a dysregulated immuno-vascular axis in chronic tobacco smokers that are otherwise considered as healthy individuals. The distinct alterations are characterized by increased CD36 expression by the blood monocyte subsets, neutrophilia and increased plasma IL-18 and reduced levels of IL-33, IL-10 and IL-8. Additionally, reduced levels of circulating BDNF and elevated sTREM2, which are associated with neurodegeneration, suggest a considerable impact of tobacco smoking on CNS function in clinically healthy individuals. These findings provide profound insight into the initial and ongoing effects of tobacco smoking and the potential vascular damage contributing to neurodegenerative disorders, specifically cerebrovascular dysfunction and dementia.

Scavenger Receptors in Myocardial Infarction and Ischemia/Reperfusion Injury: The Potential for Disease Evaluation and Therapy

Scavenger receptors (SRs) are a structurally heterogeneous superfamily of evolutionarily conserved receptors that are divided into classes A to J. SRs can recognize multiple ligands, such as modified lipoproteins, damage-associated molecular patterns, and pathogen-associated molecular patterns, and regulate lipid metabolism, immunity, and homeostasis. According to the literature, SRs may play a critical role in myocardial infarction and ischemia/reperfusion injury, and the soluble types of SRs may be a series of promising biomarkers for the diagnosis and prognosis of patients with acute coronary syndrome or acute myocardial infarction. In this review, we briefly summarize the structure and function of SRs and discuss the association between each SR and ischemic cardiac injury in patients and animal models in detail. A better understanding of the effect of SRs on ischemic cardiac injury will inspire novel ideas for therapeutic drug discovery and disease evaluation in patients with myocardial infarction.

Sustained Proinflammatory Effects of Hypoglycemia in People With Type 2 Diabetes and in People Without Diabetes

Iatrogenic hypoglycemia activates the immune system and is associated with an increased risk for atherosclerotic disease. We determined acute and long-term effects of insulin-induced hypoglycemia on inflammatory markers in humans with or without type 2 diabetes. A total of 15 adults with type 2 diabetes and 16 matched control subjects (17 men and 14 women, age 59.6 ± 7.1 years, BMI 28.5 ± 4.3 kg/m2) underwent a hyperinsulinemic-euglycemic (5.31 ± 0.32 mmol/L) hypoglycemic (2.80 ± 0.12 mmol/L) glucose clamp. Blood was drawn during euglycemia and hypoglycemia and 1, 3, and 7 days later to determine circulating immune cell composition, function, and inflammatory proteins. In response to hypoglycemia, absolute numbers of circulating lymphocytes and monocytes significantly increased and remained elevated for 1 week. The proportion of CD16+ monocytes increased, and the proportion of CD14+ monocytes decreased, which was sustained for 1 week in people without diabetes. During hypoglycemia, ex vivo stimulated monocytes released more tumor necrosis factor-α and interleukin 1β, and less interleukin 10, particularly in people with diabetes. hs-CRP and 25 circulating inflammatory proteins increased, remaining significantly elevated 1 week after hypoglycemia. While levels at euglycemia differed, responses to hypoglycemia were broadly similar in people with or without type 2 diabetes. We conclude that hypoglycemia induces a proinflammatory response at the cellular and protein level that is sustained for 1 week in people with type 2 diabetes and control subjects.

Roles of follistatin-like protein 3 in human non-tumor pathophysiologies and cancers

Follistatin-like protein 3 (FSTL3) is a type of FSTLs. By interacting with a disintegrin and metalloproteinase 12 (ADAM12), transforming growth factor-β ligands (activin, myostatin and growth differentiation factor (GDF) 11), FSTL3 can either activate or inhibit these molecules in human non-tumor pathophysiologies and cancers. The FSTL3 gene was initially discovered in patients with in B-cell chronic lymphocytic leukemia, and subsequent studies have shown that the FSTL3 protein is associated with reproductive development, insulin resistance, and hematopoiesis. FSTL3 reportedly contributes to the development and progression of many cancers by promoting tumor metastasis, facilitating angiogenesis, and inducing stem cell differentiation. This review summarizes the current pathophysiological roles of FSTL3, which may be a putative prognostic biomarker for various diseases and serve as a potential therapeutic target.

A Multiscale Study of Phosphorylcholine Driven Cellular Phenotypic Targeting

Phenotypic targeting requires the ability of the drug delivery system to discriminate over cell populations expressing a particular receptor combination. Such selectivity control can be achieved using multiplexed-multivalent carriers often decorated with multiple ligands. Here, we demonstrate that the promiscuity of a single ligand can be leveraged to create multiplexed-multivalent carriers achieving phenotypic targeting. We show how the cellular uptake of poly(2-(methacryloyloxy)ethyl phosphorylcholine)-poly(2-(diisopropylamino)ethyl methacry-late) (PMPC-PDPA) polymersomes varies depending on the receptor expression among different cells. We investigate the PMPC-PDPA polymersome insertion at the single chain/receptor level using all-atom molecular modeling. We propose a theoretical statistical mechanics-based model for polymersome-cell association that explicitly considers the interaction of the polymersome with the cell glycocalyx shedding light on its effect on the polymersome binding. We validate our model experimentally and show that the binding energy is a nonlinear function, allowing us to tune the interaction by varying the radius and degree of polymerization. Finally, we show that PMPC-PDPA polymersomes can be used to target monocytes in vivo due to their promiscuous interaction with SRB1, CD36, and CD81.

Isochlorogenic Acid C Alleviates High-Fat Diet-Induced Hyperlipemia by Promoting Cholesterol Reverse Transport

Background: Promoting cholesterol reverse transport (RCT) has been proven to be a promising hyperlipidemia therapy since it is more effective for the treatment of atherosclerosis (AS) caused by hyperlipidemia. Liver X receptor (LXR) agonists can accelerate RCT, but most of them trigger undesirable liver steatosis due to the activation of liver LXRα.

Aim: We aim to figure out whether isochlorogenic acid C (ICAC) facilitates RCT without causing hepatic steatosis.

Methods:In vitro study, we established foam macrophages and macrophages with loaded NBD-cholesterol models to investigate the competence of RCT promoting ICAC. RT-qPCR and Western blot were used to verify ICAC’s regulation of RCT and NF-κB inflammatory pathways. In this in vivo study, male 6-week-old C57BL/6 mice were fed a high-fat diet (HFD) to investigate ICAC’s anti-hyperlipidemic effect and its functions in regulating RCT. The anti-hyperlipidemic effect of ICAC was evaluated by blood and liver lipid levels, liver hematoxylin, oil red o staining, and liver coefficient. Finally, mRNA levels of genes involved in RCT and inflammation pathways in the liver and intestine were detected by RT-qPCR.

Results: ICAC prevented macrophages from foaming by up-regulating the LXRα mediated RCT pathway and down-regulating expression of the cholesterol absorption genes LDLR and CD36, as well as suppressing iNOS, COX2, and IL-1β inflammatory factors. In HFD-fed mice, ICAC significantly lowered the lipid level both in the serum and the liver. Mechanistic studies showed that ICAC strengthened the RCT pathway in the liver and intestine but didn’t affect liver LXRα. Furthermore, ICAC impeded both adipogenesis and the inflammatory response in the liver.

Conclusion: ICAC accelerated RCT without affecting liver LXRα, thus resulting in a lipid-lowering effect without increasing liver adipogenesis. Our results indicated that ICAC could be a new RCT promoter for hyperlipidemia treatment without causing liver steatosis.

Thrombosis and Anticoagulation Therapy in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease in which pathogenic autoantibodies and immune complexes are formed and mediate multiple organ and tissue damage. Thrombosis is one of the most common causes of death in patients with SLE. Anticoagulant therapy blocks the vicious cycle between inflammation and thrombosis, which may greatly improve the long-term prognosis of patients with SLE. However, the etiology and pathogenesis of this disease are very complicated and have not yet been fully clarified. Therefore, in the present review, we will highlight the characteristics and mechanisms of thrombosis and focus on the anticoagulant drugs commonly used in clinical practice, thus, providing a theoretical basis for scientific and reasonable anticoagulant therapy in clinical practice.

Systematic analysis of olfactory protein-protein interactions network of fruitfly, Drosophila melanogaster

Olfaction is one of the physiological traits of insect behavior. Insects have evolved a sophisticated olfactory system and use a combined coding strategy to process general odor. Drosophila melanogaster is a powerful model to reveal the molecular and cellular mechanisms of odor detection. Identifying new olfactory targets through complex interactions will contribute to a better understanding of the functions, interactions, and signaling pathways of olfactory proteins. However, the mechanism of D. melanogaster olfaction is still unclear, and more olfactory proteins are required to be discovered. In this study, we tried to explore essential proteins in the olfactory system of D. melanogaster and conduct protein-protein interactions (PPIs) analysis. We constructed the PPIs network of the olfactory system of D. melanogaster, consisting of 863 proteins and 18,959 interactions. Various methods were used to perform functional enrichment analysis, topological analysis and cluster analysis. Our results confirmed that Class B scavenger receptors (SR-Bs), glutathione S-transferases (GSTs), and UDP-glycosyltransferases (UGTs) play an essential role in olfaction of D. melanogaster. The proteins obtained in this study can be used for subsequent functional identification in D. melanogaster olfactory.