Atherosclerotic Plaque Formation Research Articles

LOX-1 in Cardiovascular Disease: A Comprehensive Molecular and Clinical Review.

LOX-1, ORL-1, or lectin-like oxidized low-density lipoprotein receptor 1 is a transmembrane glycoprotein that binds and internalizes ox-LDL in foam cells. LOX-1 is the main receptor for oxidized low-density lipoproteins (ox-LDL). The LDL comes from food intake and circulates through the bloodstream. LOX-1 belongs to scavenger receptors (SR), which are associated with various cardiovascular diseases. The most important and severe of these is the formation of atherosclerotic plaques in the intimal layer of the endothelium. These plaques can evolve into complicated thrombi with the participation of fibroblasts, activated platelets, apoptotic muscle cells, and macrophages transformed into foam cells. This process causes changes in vascular endothelial homeostasis, leading to partial or total obstruction in the lumen of blood vessels. This obstruction can result in oxygen deprivation to the heart. Recently, LOX-1 has been involved in other pathologies, such as obesity and diabetes mellitus. However, the development of atherosclerosis has been the most relevant due to its relationship with cerebrovascular accidents and heart attacks. In this review, we will summarize findings related to the physiologic and pathophysiological processes of LOX-1 to support the detection, diagnosis, and prevention of those diseases.

Broader Perspective on Atherosclerosis-Selected Risk Factors, Biomarkers, and Therapeutic Approach.

Atherosclerotic cardiovascular disease (ASCVD) stands as the leading cause of mortality worldwide. At its core lies a progressive process of atherosclerosis, influenced by multiple factors. Among them, lifestyle-related factors are highlighted, with inadequate diet being one of the foremost, alongside factors such as cigarette smoking, low physical activity, and sleep deprivation. Another substantial group of risk factors comprises comorbidities. Amongst others, conditions such as hypertension, diabetes mellitus (DM), chronic kidney disease (CKD), or familial hypercholesterolemia (FH) are included here. Extremely significant in the context of halting progression is counteracting the mentioned risk factors, including through treatment of the underlying disease. What is more, in recent years, there has been increasing attention paid to perceiving atherosclerosis as an inflammation-related disease. Consequently, efforts are directed towards exploring new anti-inflammatory medications to limit ASCVD progression. Simultaneously, research is underway to identify biomarkers capable of providing insights into the ongoing process of atherosclerotic plaque formation. The aim of this study is to provide a broader perspective on ASCVD, particularly focusing on its characteristics, traditional and novel treatment methods, and biomarkers that can facilitate its early detection.

Exploring the role of myeloperoxidase in the atherosclerotic process in hypoxic mice based on the MAPK signaling pathway

Atherosclerosis (AS) is the common pathophysiological basis of various cardiovascular diseases and the leading cause of death from cardiovascular disease worldwide. When the body is in a hypoxic environment, enhanced oxidative stress and significant accumulation of reactive oxygen species (ROS) in tissue cells exacerbate the inflammatory response, resulting in increased release of myeloperoxidase (MPO), catalyzing the formation of large quantities of hypochlorous acid (HOCl), further oxidative modification of low-density lipoprotein (LDL), and exacerbating the formation and progression of atherosclerotic plaques. The MAPK signaling pathway is important in oxidative stress-mediated promotion of atherogenesis. MPO -/- mice were used in this study to establish a hypoxia model simulating 5000 m altitude and a Western high-fat diet-induced atherosclerosis model for 12 weeks. Exploring the role of MPO in the atherosclerotic process in hypoxic mice by observing the MAPK signaling pathway to provide a therapeutic target for the prevention and treatment of hypoxic atherosclerotic disease in the plateau. We found that hypoxia promotes the formation of atherosclerosis in mice, and the mechanism may be that increased MPO in vivo promotes an inflammatory response, which plays a crucial role in the formation of atherosclerosis. In addition, hypoxia further exacerbates plaque instability by activating the MAPK signaling pathway to upregulate vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP9), which in turn promotes angiogenesis within the plaque. Therefore, a potential target for preventing and treating hypoxic atherosclerotic disease is the inhibition of MPO.

The role of γδT lymphocytes in atherosclerosis.

Atherosclerosis poses a significant threat to human health, impacting overall well-being and imposing substantial financial burdens. Current treatment strategies mainly focus on managing low-density lipids (LDL) and optimizing liver functions. However, it's crucial to recognize that Atherosclerosis involves more than just lipid accumulation; it entails a complex interplay of immune responses. Research highlights the pivotal role of lipid-laden macrophages in the formation of atherosclerotic plaques. These macrophages attract lymphocytes like CD4 and CD8 to the inflamed site, potentially intensifying the inflammatory response. γδ T lymphocytes, with their diverse functions in innate and adaptive immune responses, pathogen defense, antigen presentation, and inflammation regulation, have been implicated in the early stages of Atherosclerosis. However, our understanding of the roles of γδ T cells in Atherosclerosis remains limited. This mini-review aims to shed light on the characteristics and functions of γδ T cells in Atherosclerosis. By gaining insights into the roles of γδ T cells, we may uncover a promising strategy to mitigate plaque buildup and dampen the inflammatory response, thereby opening new avenues for effectively managing this condition.

Macrophage-Derived GSDMD Plays an Essential Role in Atherosclerosis and Cross Talk Between Macrophages via the Mitochondria-STING-IRF3/NF-κB Axis.

Macrophages play a crucial role in atherosclerotic plaque formation, and the death of macrophages is a vital factor in determining the fate of atherosclerosis. GSDMD (gasdermin D)-mediated pyroptosis is a programmed cell death, characterized by membrane pore formation and inflammatory factor release. ApoE-/- and Gsdmd-/- ApoE-/- mice, bone marrow transplantation, and AAV (adeno-associated virus serotype 9)-F4/80-shGSDMD (shRNA-GSDMD) were used to examine the effect of macrophage-derived GSDMD on atherosclerosis. Single-cell RNA sequencing was used to investigate the changing profile of different cellular components and the cellular localization of GSDMD during atherosclerosis. First, we found that GSDMD is activated in human and mouse atherosclerotic plaques and Gsdmd-/- attenuates the atherosclerotic lesion area in high-fat diet-fed ApoE-/- mice. We performed single-cell RNA sequencing of ApoE-/- and Gsdmd-/- ApoE-/- mouse aortas and showed that GSDMD is principally expressed in atherosclerotic macrophages. Using bone marrow transplantation and AAV-F4/80-shGSDMD, we identified the potential role of macrophage-derived GSDMD in aortic pyroptosis and atherosclerotic injuries in vivo. Mechanistically, GSDMD contributes to mitochondrial perforation and mitochondrial DNA leakage and subsequently activates the STING (stimulator of interferon gene)-IRF3 (interferon regulatory factor 3)/NF-κB (nuclear factor kappa B) axis. Meanwhile, GSDMD regulates the STING pathway activation and macrophage migration via cytokine secretion. Inhibition of GSDMD with GSDMD-specific inhibitor GI-Y1 (GSDMD inhibitor Y1) can effectively alleviate the progression of atherosclerosis. Our study has provided a novel macrophage-derived GSDMD mechanism in the promotion of atherosclerosis and demonstrated that GSDMD can be a potential therapeutic target for atherosclerosis.

Abstract 1039: Endothelial Deletion Of Nck1 Reduces Atherosclerosis In Apoe-/- Mice Through The Nck1-atf3 Axis

The Nck family of signaling adaptors, including both Nck1 and Nck2, classically regulate cell motility during vascular development and postnatal angiogenesis. While Nck1 and Nck2 play redundant roles in this regard with deletion of both isoforms required to affect tissue remodeling, we demonstrated that global Nck1 deletion was sufficient to reduce atherosclerotic plaque formation and selective Nck1 inhibition reduces proinflammatory endothelial activation in response to oscillatory shear stress. Therefore, we sought to determine the role of endothelial Nck1 in atherosclerosis and ischemic angiogenesis using novel endothelial-specific Nck1 knockout mice. Endothelial-specific Nck1 deletion significantly reduced Western diet-induced atherosclerotic plaque formation at multiple sites compared to mice expressing endothelial-specific Cre alone or to endothelial-specific Nck2 knockout mice. This reduced plaque formation was characterized by diminished macrophage and smooth muscle incorporation despite enhanced weight gain in endothelial Nck1 knockout mice. RNA Sequencing analysis of endothelial cells in culture showed that Nck1 depletion reduces the expression of a variety of proinflammatory pathways but enhances the expression of genes involved in central carbon metabolism and proliferation. While Nck1 deletion is sufficient to blunt atherogenic inflammation, Nck1 inhibition did not affect angiogenesis or limb perfusion in the femoral artery ligation model of hind limb ischemia. To further characterized Nck1’s proinflammatory role, we utilized affinity precipitation-mass spectrometry and identified Activating Transcription Factor 3 ATF3 as a Nck1-selective binding partner. While no studies to date have examined endothelial ATF3 signaling in atherosclerosis, our preliminary data show that Nck1 is required for ATF3 expression in response to disturbed flow in vitro and in vivo , but the mechanism by which disturbed flow stimulates ATF3 expression remains unknown. ATF3 knockdown reduces disturbed flow-induced proinflammatory gene expression, suggesting that the Nck1-ATF3 signaling axis is a novel regulator of flow-induced inflammation.

Abstract 2069: Impact Of Endothelial Stiffening And CD36-mediated Lipid Uptake On Atherosclerotic Lesion Formation

Objective: To determine the impact of endothelial stiffening induced by CD36 (cluster of differentiation 36) lipid uptake in the development of atherosclerosis. Approach and Results: Endothelial stiffening of intact en face monolayers, as assessed by atomic force microscopy, reveal the hyperlipidemic mouse model of atherosclerosis, LDLR -/- (low density lipoprotein receptor knockout) is significantly stiffer, especially in the atheroprone aortic arch, as compared to wild type controls (n=4 male mice with 8-15 tissue measurement sites per condition per mouse, p<0.05). Furthermore, a 4-5 month high fat diet (HFD) feeding in LDLR -/- mice resulted in significantly enhanced stiffening compared to regular chow feeding, an effect that was observed in males but not females (n=6-8 mice, p<0.05). There was a significantly greater plaque development, as analyzed using Oil O Red staining for lipids, in male HFD-fed LDLR -/- mice, as compared to age-matched females (n=5-6, p<0.05). No significant difference between males and females was found in lipid panel parameters (n=4-6) or weight gain (n=10-14). Specific downregulation of CD36 in male hypercholesterolemic Cdh5.CreERT2CD36fl/fl LDLR -/- mice led to both a significant decrease in endothelial stiffening (n=5 mice, p<0.05) and in the areas of atherosclerotic lesion formation (n=5-6 mice, p<0.05). Mechanistically, we show that the saturated fatty acid, palmitic acid, increased endothelial stiffening in the en face monolayers of wild type mice, an effect which is prevented by the pre-treatment of the CD36 irreversible inhibitor, SSO (sulfo-N-succinimidyl oleate, n=5-6 male mice, p<0.05). Conclusions: These results highlight that endothelial stiffness from intact aortas and atherosclerotic plaque formation following HFD feeding is strongly dependent on endothelial CD36.

Abstract 1053: The Role Of Bile Acid-initiated Signaling In Vascular Smooth Muscle Cell Phenotypic Switching And Atherosclerosis

Atherosclerosis is a chronic inflammatory disease in which foam cells (lipid-laden macrophage-like cells) accumulate in the arterial wall. Vascular smooth muscle cells (VSMCs) are not terminally differentiated; they switch to a foam cell-like phenotype in response to various stimuli, such as cholesterol (CHOL), increasing susceptibility to vascular diseases. Modulated SMCs are the main contributors to atherosclerotic plaque formation. The intracellular metabolism of CHOL via peroxisomes in hepatocytes produces bile acids like cholic or deoxycholic acid, which agonize liver X receptor (LXR). LXR facilitates the first step of reverse CHOL transport. It is unknown if VSMCs synthesize bile acids and whether peroxisomes and the bile acids they produce play a role in VSMC-derived foam cell formation. Using human aortic SMCs (HASMCs), we found that CHOL treatment decreased expression of several peroxisomal proteins. Peroxisomal loss-of-function experiments demonstrated increased intracellular lipid accumulation, as visualized with Oil Red O (ORO) staining. We have shown that HASMCs synthesize bile acids after exposure to CHOL, which led us to hypothesize that bile acid-initiated signaling participates in the phenotypic modulation initiated by CHOL in VSMCs. Treatment of HASMCs with LXR agonists or bile acids increased expression of the efflux CHOL transporter ABCA1, bile acid-related peroxisomal enzymes, and differentiation markers; they decreased expression of macrophage and foam cell markers and ORO staining. These data show that VSMCs have the metabolic capacity to synthesize bile acids, which is impaired if peroxisomes are non-functional or absent. Our data indicates that activation of bile acid receptors upregulates ABCA1, favoring a differentiated VSMC phenotype. Together, these data suggest that activation of LXR plays a role in CHOL-induced VSMC to foam cell transition and that LXR is a potential therapeutic target which promotes VSMC differentiation and decreases atherosclerotic plaque formation.

Abstract 3078: Free Fatty Acid Receptor 4: An Emerging Target To Reduce Atherosclerosis

Free fatty acid receptor 4 (FFAR4) has recently emerged as a target for preventing CVD through its ability to reduce macrophage foam cell formation and inflammation. We have shown that activation of FFAR4 by synthetic agonists decreases foam cell formation, whereas deficiency of FFAR4 increases foam cell formation. Building on these data, we hypothesized that FFAR4 would protect against atherosclerotic plaque formation in vivo . To test this hypothesis, we generated global FFAR4 knockout mice on an apoE-deficient background. Male and female apoE/FFAR4 double knockout mice (n=20) and their apoE knockout controls (n=20) were fed a Western diet (42% calories from fat and 0.2% cholesterol) for 16 weeks. We collected weekly body weights and fasting plasma samples from mice at 0, 8, and 16 weeks to measure triglyceride and cholesterol levels. At the end of the 16-week study, atherosclerotic plaque severity was determined by analyzing the aortic sinus lesion area of the heart and the en-face lesion area of the aortic arch. In both the male and female mice, we observed no differences in weekly body weights or lipid levels between the apoE knockout and apoE/FFAR4 double knockout mice. In our first cohort of male mice (n=10), the two genotypes showed no difference in the aortic sinus lesion area. However, male apoE/FFAR4 double knockout mice had a statistically significant (p=0.039) 1.4-fold increase in total aortic arch lesion area compared to FFAR4-deficient mice. While female mice (n=9) showed no differences in atherosclerotic plaque in the aortic sinus and aortic arch between the two genotypes, they did present with 1.7-fold (p=0.002) and 2-fold increases (p=0.009) in aortic sinus lesion area and aortic arch lesion area, respectively, as compared to male mice. Based on analysis of an initial set of mice, our data support a protective role for FFAR4 in the development of atherosclerotic plaque formation in male mice, and our findings may have uncovered a new therapeutic target against atherosclerosis.

Abstract 3019: Piezo-1 Expression Decreases Under Disturbed Flow Model Of Femoral Atherosclerosis.

Background: Peripheral arterial disease (PAD) is often manifest by focal atherosclerotic plaque formation in the infra-inguinal arteries. However, murine models of atherosclerosis in the infra-inguinal arteries are lacking. It is well known that low and oscillatory wall shear stress, which occurs around blockages in PAD, promotes focal atherosclerotic plaque, but this has not been tested in vivo. Piezo1 is a mechanosensitive ion channel associated with hemodynamic changes in the arterial wall, but its role in flow-mediated atherosclerotic plaque deposition is not known. Objective: To develop a flow-mediated murine model of focal atherosclerotic plaque in the femoral arteries. Methods: 8 male and female S129 mice underwent partial femoral artery ligation (Figure A/B). Wall shear stress was calculated from duplex ultrasound imaging (Figure C/D). Atherogenic conditions were imposed with PCSK9 infection and high fat diet; this was initiated 1 week prior to partial femoral ligation. Histologic comparison of the left (partial femoral ligation) and right (normal stable flow) was performed. Results: Low wall shear stress was induced in this model (Figure C/D). Piezo1 expression was decreased in both male and female arteries under these conditions in this model (Figure E). Atherosclerotic plaque was induced by the partial femoral artery ligation but not on the normal stable flow side (Figure F). Conclusions: We have successfully developed a flow-mediated model of focal atherosclerotic plaque in murine femoral arteries. This is associated with downregulation of Piezo1 gene expression. Ongoing work is examining the causative role of Piezo1 on endothelial response to disturbed flow.

RELATIONSHIP BETWEEN NEUTROPHILTO HIGH-DENSITY LIPOPROTEIN CHOLESTEROL AND THE SEVERITY OF CORONARY STENOSIS IN PATIENT WITH CORONARY ARTERY DISEASE

Objective: Coronary artery disease (CAD) is a common cardiovascular disease related to atherosclerotic plaque formation. The Neutrophil to HDL-C ratio (NHR) reflects the inflammation process and dyslipidemia, affecting the atherosclerosis pathophysiology. This study aims to evaluate the relationship between NHR and the severity of coronary stenosis in CAD patients. Design and method: A prospective study with in-hospital follow-up in all patients admitted to Cardiology Center - Hue Central Hospital, whose were diagnosed with coronary artery disease between April 2023 and February 2024 were enrolled. The diagnostic criteria of CAD according to the recommendation of the Vietnam National Heart Association 2022. All patients received a comprehensive clinical examination and laboratory tests: complete blood count, high-sensitive Troponin-T, Total Cholesterol, HDL-Cholesterol, 12-leads EKG, transthoracic echocardiogram. All patients were undergone coronary angiography with doctor recommendation or self-requirement. Patients with history of coronary artery interventions, either balloon or stenting, or patient with history of coronary artery bypass graft were excluded from the study. Patients with acute or chronic infection state, end-stage kidney failure, end-stage renal disease, severe heart failure, severe valvular diseases and hematology diseases, patients being used corticosteroid therapy were also excluded. Results: Mean age was 67.12 ± 11.39 years, 58.5% male. The mean NHR increased according to Gensini score subgroups (p < 0,01). Compared to the group with unincreased hs-Troponin (4.38 ± 1.56), the group with increased hs-Troponin showed a significantly higher mean NHR (6.14 ± 3.17) (p < 0.01). There was a moderate correlation between NHR and Gensini score with r = 0.343, p<0.01. NHR demonstrated moderate ability to predict patients with significant narrowing of coronary branches with the AUC= 0.727. With the NHR at 5.324, NHR has 54.2% in sensitivity and 83.3% of specificity in predicting of the significant coronary artery stenosis. Conclusions: Our study demonstrated there was a moderate correlation between Neutrophil to HDL-C ratio (NHR) and Gensini score. Neutrophil to HDL-C ratio (NHR) demonstrated moderate ability to predict patients with significant narrowing of coronary branches.

PNPLA3 I148M Promotes Fatty Liver Disease While Preserving Cardiac Health

Metabolic-associated fatty liver disease (MAFLD) and cardiovascular disease (CVD) are commonly associated comorbidities. A common genetic variant in the PNPLA3 gene, rs738409 (I148M), is the greatest genetic risk factor for development and progression of MAFLD; however, MAFLD patients expressing PNPLA3 I148M display modest protection against coronary artery disease (CAD) and adverse cardiovascular events relative to wildtype carriers. Currently, the exact mechanisms by which PNPLA3 I148M causes MAFLD and preserves cardiac health are not well understood. Previous work suggests that the variant increases susceptibility to fatty liver disease by altering hepatic lipid metabolism, which may explain a potential mechanism for its cardioprotective effects. In order to investigate how PNPLA3 I148M might increase susceptibility to MAFLD while reducing risk of CVD we expressed either human wildtype (WT) PNPLA3 or PNPLA3 I148M as well as a GFP control specifically in the livers of PNPLA3 knockout mice. Our data demonstrate that hepatic expression of PNPLA3 I148M reduces secretion of VLDL TAGs from adipose tissue derived fatty acids. In agreement with prior investigations, mice expressing PNPLA3 I148M and fed a chow diet demonstrated significant increases in hepatic accumulation of neutral lipids (triglycerides & cholesterol esters) relative to WT and GFP expressing mice. Similarly, when fed a fatty liver promoting diet (D009100310) high in fructose, cholesterol, and saturated fats there remained a strong trend for greater liver to body weight ratios and hepatic TAGs in mice expressing the variant when compared to WT expressing mice (p=0.052 and p=0.071 respectively). Changes in hepatic lipid accumulation were not due to any alterations in insulin sensitivity, daily food consumption, energy expenditure or oxygen consumption between WT and I148M groups. Echocardiography revealed that hearts of mice expressing WT PNPLA3 had increases in left ventricular thickness (p=0.051) and left ventricle weights following dietary treatment that was not apparent in the I148M expressing mice. Moreover, there was a reduction in E/A ratios, a sensitive measure of diastolic functioning, in GFP and WT expressing mice post-treatment, that was not seen in the I148M mice. Overall, these findings indicate that PNPLA3 I148M promotes fatty liver, yet protects against diet-induced effects on ventricular remodeling and diastolic functioning. Our next steps will be to assess measures of atherosclerotic plaque formation around major blood vessels and investigate the metabolic pathways altered by PNPLA3 I148M. NIH R00 DK114471 NIH R01 DK126743 USDA grant no. 2021-09425 Pilot feasibility grant from University of Michigan: P30DK020572 Detroit Cardiovascular Training grant NIH 2T32HL120822. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Proteomic Signatures of Coronary Artery Disease and Hypercholesterolemia

Background: Coronary artery disease (CAD) is the most common type of cardiovascular disease (CVD), it causes narrowing of the blood vessel lumen due to atherosclerotic plaque formation. Atherosclerosis, is strongly influenced by hypercholesterolemia (HC). Proteomics offers advantages over traditional studies that focus on individual biomarkers. This method provides a holistic view by examining the entire proteomic spectrum in a biological sample, making it an indispensable asset for spotting potential novel protein biomarkers directly linked to atherosclerosis occurrence, progression, and complications such as plaque instability or rupture. Methods: Slow Off-rate Modified Aptamer (SOMAmer)-based protein array was used to quantify proteins. Our cross-sectional study involved healthy controls (n=45), and patients diagnosed with HC (n=51) or CAD (n=32). Proteome data was analyzed using multiple statistical methods. Results: The orthogonal partial least square discriminant analysis (OPLS-DA) revealed a clear separation of the 3 study groups based on two principal components, with R2X= 0.267, R2Y= 0.9, and Q2= 0.28, indicating distinct protein alterations between groups. A total of 1,305 proteins were analyzed and 156 of them in CAD vs control, 140 of them in HC vs control, and 326 of the proteins in CAD vs HC comparisons, were significantly differentially expressed with a p-value<0.05. Among those, q-value<0.05 were determined. As a result, in CAD patients, 2 proteins exhibited significantly differential expressions compared to healthy controls. In contrast, HC patients had 15 significantly altered proteins compared to controls. Furthermore, a comparison between CAD and HC patients revealed 87 significantly regulated proteins. The receiver operating characteristic (ROC) was performed on proteins with distinct expressions ( q<0.05) in pairwise group comparisons. The AUC was calculated to identify potential biomarker candidates for the disease groups. In the CAD vs. control analysis, both significant proteins (PCSK9, SDF-1) exhibited an AUC of 0.75. In the comparison between HC and control groups, out of 15 significantly altered proteins, 7 had an AUC of 0.75 or higher (LRP1B, Apo E, QORL1, Apo E3, Apo B, Transferrin, MMP-3). Among the 87 proteins significantly differentially expressed in CAD versus HC, 59 had an AUC ≥ 0.75. Sixteen of these proteins had an AUC ≥ 0.80. Conclusion: Distinct protein patterns associated with each condition were identified. CAD patients showed a significant increase in the cholesterol-metabolizing protein PCSK9 and varying levels of the angiogenesis-related protein SDF-1. Several other proteins (LRP1B, VAV, CSRP3, HSP 60, and TAK1-TAB1) also exhibited unique expressions in disease groups, suggesting potential roles in atherosclerosis development. Moreover, a statistically significant correlation between SDF-1, ApoB levels, and LDL levels was found in CAD patients but not in healthy controls. This discovery phase cohort study unveils potential biomarkers for atherosclerosis within the HC context. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

ASYMPTOTIC STABILITY FOR A FREE BOUNDARY MODEL OF AN ATHEROSCLEROTIC PLAQUE FORMATION IN THE PRESENCE OF REVERSE CHOLESTEROL TRANSPORT WITH HOLLING TYPE-III FUNCTIONAL RESPONSE

Atherosclerosis, as a chronic inflammatory disease, has been a threat to human health. How to diagnose and prevent this disease has long been the focus of medical and biomathematics study. In this paper, we investigate a free boundary model of an atherosclerotic plaque formation in the presence of reverse cholesterol transport, which includes low-density lipoprotein, high-density lipoprotein, endothelial stimulating cytokines, pro-inflammatory and anti-inflammatory macrophages, as well as foam cells. For this model, we use the Holling type-III response function instead of the usual Holling type-II to describe the change of the concentration of each substance. We first introduce the auxiliary function [Formula: see text] to prove the existence and uniqueness of small radially symmetric stationary plaque for appropriate [Formula: see text] and [Formula: see text] by using the contraction mapping principle and maximum principle, and then establish a condition to ensure their asymptotic stability behavior by expanding the corresponding steady-state solution.

Engineering Nanoplatforms for Theranostics of Atherosclerotic Plaques.

Atherosclerotic plaque formation is considered the primary pathological mechanism underlying atherosclerotic cardiovascular diseases, leading to severe cardiovascular events such as stroke, acute coronary syndromes, and even sudden cardiac death. Early detection and timely intervention of plaques are challenging due to the lack of typical symptoms in the initial stages. Therefore, precise early detection and intervention play a crucial role in risk stratification of atherosclerotic plaques and achieving favorable post-interventional outcomes. The continuously advancing nanoplatforms have demonstrated numerous advantages including high signal-to-noise ratio, enhanced bioavailability, and specific targeting capabilities for imaging agents and therapeutic drugs, enabling effective visualization and management of atherosclerotic plaques. Motivated by these superior properties, various noninvasive imaging modalities for early recognition of plaques in the preliminary stage of atherosclerosis are comprehensively summarized. Additionally, several therapeutic strategies are proposed to enhance the efficacy of treating atherosclerotic plaques. Finally, existing challenges and promising prospects for accelerating clinical translation of nanoplatform-based molecular imaging and therapy for atherosclerotic plaques are discussed. In conclusion, this review provides an insightful perspective on the diagnosis and therapy of atherosclerotic plaques.

The Role of Macrophage Dynamics in Atherosclerosis Analyzed Using a Petri Net-Based Model

Atherosclerosis, a chronic inflammatory and oxidative stress-mediated disease impacting the arterial system, stands as a primary cause of morbidity and mortality worldwide. The complexity of this disease, driven by numerous factors, requires a thorough investigation of its underlying mechanisms. In our study, we explore the complex interplay between cholesterol homeostasis, macrophage dynamics, and atherosclerosis development using a Petri net-based model anchored in credible, peer-reviewed biological and medical research. Our findings underscore the significant role of macrophage colony-stimulating factor (M-CSF) inhibition in reducing atherosclerotic plaque formation by modulating inflammatory responses and lipid accumulation. Furthermore, our model highlights the therapeutic potential of targeting the C-X-C motif ligand 12 (CXCL12)/ C-X-C motif chemokine receptor type 4 (CXCR4) pathway to hinder hematopoietic stem and progenitor cells’ (HSPCs’) mobilization and plaque development. Based on the results obtained, which are in agreement with current studies, additional strategies are also proposed, such as decreasing M1 macrophage polarization for therapeutic gains, opening the door to future research and novel treatment approaches.

Gut microbiome and metabolomic profiles reveal the antiatherosclerotic effect of indole-3-carbinol in high-choline-fed ApoE-/- mice

BackgroundThe metabolites produced from choline contribute to atherosclerosis (AS) pathogenesis, and the gut microbiota is redundantly essential for this process. Indole-3-carbinol (I3C), found in cruciferous vegetables such as broccoli, cabbage, cauliflower and brussels sprouts, helps prevent hyperlipidemia, maintain the gut microbiota balance, and decrease the production of trimethylamine-N-oxide (TMAO) from choline in the diet. PurposeThe objective of this research was to investigate the impact of I3C on choline-induced AS and to further elucidate the underlying mechanism involved. MethodsAS models of high-choline-induced ApoE-/- mice and TMAO-promoted foamy macrophages were established to observe the effect of I3C on the formation of atherosclerotic plaques and foam cells and changes in AS-related indicators (including blood biochemical indicators, TMA, TMAO, SRA, and SRB1), and integrated analyses of the microbiome and metabolome were used to reveal the mechanism of action of I3C. ResultsWe found that I3C inhibited high-choline-induced atheroma formation (50–100 mg/kg/d, in vivo) and slightly improved the lipid profile (15 mg/kg/d, in vivo). Moreover, I3C suppressed lipid influx at a concentration of 40 µmol/L in vitro, enhanced the diversity of the gut microbiota and the abundance of the phylum Verrucomicrobia, and consequently modified the gut microbial metabolites at a dosage of 50 mg/kg/d in the mice. Associative analyses based on microbiome and metabolomics revealed that 1-methyladenosine was a key modulator of the protective effect of I3C against AS in high-choline-induced ApoE-/- mice. ConclusionThese findings demonstrate for the first time that I3C ameliorates AS progression through remodeling of the gut microbiome and metabolomics, which paves the way for the possible therapeutic use of this vegetable-derived natural compound and may reduce the clinical severity of AS-related cardiovascular diseases.

The Role of Fatty Acid Synthase in the Vascular Smooth Muscle Cell to Foam Cell Transition.

Vascular smooth muscle cells (VSMCs), in their contractile and differentiated state, are fundamental for maintaining vascular function. Upon exposure to cholesterol (CHO), VSMCs undergo dedifferentiation, adopting characteristics of foam cells-lipid-laden, macrophage-like cells pivotal in atherosclerotic plaque formation. CHO uptake by VSMCs leads to two primary pathways: ABCA1-mediated efflux or storage in lipid droplets as cholesterol esters (CEs). CE formation, involving the condensation of free CHO and fatty acids, is catalyzed by sterol O-acyltransferase 1 (SOAT1). The necessary fatty acids are synthesized by the lipogenic enzyme fatty acid synthase (FASN), which we found to be upregulated in atherosclerotic human coronary arteries. This observation led us to hypothesize that FASN-mediated fatty acid biosynthesis is crucial in the transformation of VSMCs into foam cells. Our study reveals that CHO treatment upregulates FASN in human aortic SMCs, concurrent with increased expression of CD68 and upregulation of KLF4, markers associated with the foam cell transition. Crucially, downregulation of FASN inhibits the CHO-induced upregulation of CD68 and KLF4 in VSMCs. Additionally, FASN-deficient VSMCs exhibit hindered lipid accumulation and an impaired transition to the foam cell phenotype following CHO exposure, while the addition of the fatty acid palmitate, the main FASN product, exacerbates this transition. FASN-deficient cells also show decreased SOAT1 expression and elevated ABCA1. Notably, similar effects are observed in KLF4-deficient cells. Our findings demonstrate that FASN plays an essential role in the CHO-induced upregulation of KLF4 and the VSMC to foam cell transition and suggest that targeting FASN could be a novel therapeutic strategy to regulate VSMC phenotypic modulation.

Biomechanics-mediated endocytosis in atherosclerosis.

Biomechanical forces, including vascular shear stress, cyclic stretching, and extracellular matrix stiffness, which influence mechanosensitive channels in the plasma membrane, determine cell function in atherosclerosis. Being highly associated with the formation of atherosclerotic plaques, endocytosis is the key point in molecule and macromolecule trafficking, which plays an important role in lipid transportation. The process of endocytosis relies on the mobility and tension of the plasma membrane, which is sensitive to biomechanical forces. Several studies have advanced the signal transduction between endocytosis and biomechanics to elaborate the developmental role of atherosclerosis. Meanwhile, increased plaque growth also results in changes in the structure, composition and morphology of the coronary artery that contribute to the alteration of arterial biomechanics. These cross-links of biomechanics and endocytosis in atherosclerotic plaques play an important role in cell function, such as cell phenotype switching, foam cell formation, and lipoprotein transportation. We propose that biomechanical force activates the endocytosis of vascular cells and plays an important role in the development of atherosclerosis.

CircHIPK3 targets DRP1 to mediate hydrogen peroxide-induced necroptosis of vascular smooth muscle cells and atherosclerotic vulnerable plaque formation

IntroductionNecroptosis triggered by H2O2 is hypothesized to be a critical factor in the rupture of atherosclerotic plaques, which may precipitate acute cardiovascular events. Nevertheless, the specific regulatory molecules of this development remain unclear. We aims to elucidate a mechanism from the perspective of circular RNA. ObjectivesThere are few studies on circRNA in VSMCs necroptosis. The objective of our research is to shed light on the intricate roles that circHIPK3 plays in the process of necroptosis in VSMCs and the development of atherosclerotic plaques that are prone to rupture. Our study elucidates the specific molecular mechanisms by which circHIPK3 regulates necroptosis and atherosclerotic vulnerable plaque formation through targeted proteins. Identifying this mechanism at the cellular level offers a molecular framework for understanding plaque progression and stability regulation, as well as a potential biomarker for the prognosis of susceptible atherosclerotic plaques. MethodsWe collected clinical vascular tissue for HE staining and Masson staining to determine the presence and stability of plaques. Then, NCBI database was used to screen out circRNA with elevated expression level in plaque tissue, and the up-regulated circRNA, circHIPK3, was verified by qRT-PCR and FISH. Further, we synthesized circHIPK3′s small interference sequence and overexpressed plasmid in vitro, and verified its regulation effect on necroptosis of VSMCs under physiological and pathological conditions by WB, qRT-PCR and PI staining. Through RNA pull down, mass spectrometry and RNA immunoprecipitation, DRP1 was identified as circHIPK3 binding protein and was positively regulated by circHIPK3. Meanwhile, on the basis of silencing of DRP1, the regulation of circHIPK3 on necroptosis is verified to be mediated by DRP1. Finally, we validated the regulation of circHIPK3 on vulnerable plaque formation in ApoE-/- mice. ResultsWe investigated that circHIPK3 was highly expressed in vulnerable plaques, and the increase in expression level promoted H2O2 induced necroptosis of VSMCs. CircHIPK3 targeted the protein DRP1, leading to an elevation in mitochondrial division rate, resulting in increased reactive oxygen species and impaired mitochondrial function, ultimately leading to necroptosis of VSMCs and vulnerable plaque formation. ConclusionCircHIPK3 interact with DRP1 involve in H2O2 induced Mitochondrial damage and necroptosis of VSMCs, and Silencing circHIPK3 in vivo can reduce atherosclerotic vulnerable plaque formation. Our research findings may have applications in providing diagnostic biomarkers for vulnerable plaques.