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Monocyte-to-macrophage differentiation and subsequent foam cell formation are key processes that contribute to plaque build-up during the progression of atherosclerotic lesions. Palmitoylation enzymes are known to play pivotal roles in the development and progression of inflammatory diseases. However, their specific impact on atherosclerosis development remains unclear. In this study, we discovered that the knockout of zDHHC1 in THP-1 cells, as well as Zdhhc1 in mice, markedly reduces the uptake of oxidized low-density lipoprotein (ox-LDL) by macrophages, thereby inhibiting foam cell formation. Moreover, the absence of Zdhhc1 in ApoE -/- mice significantly suppresses atherosclerotic plaque formation. Mass spectrometry coupled with bioinformatic analysis revealed an enrichment of the PI3K-Akt-mTOR signaling pathway. Consistent with this, we observed that knockout of zDHHC1 significantly decreases the palmitoylation levels of p110α, a crucial subunit of PI3K. Notably, the deletion of Zdhhc1 facilitates the nuclear translocation of p110α in macrophages, leading to a significant reduction in the downstream phosphorylation of Akt at Ser473 and mTOR at Ser2448. This cascade results in a decreased number of macrophages within plaques and ultimately mitigates the severity of atherosclerosis. These findings unveil a novel role for zDHHC1 in regulating foam cell formation and the progression of atherosclerosis, suggesting it as a promising target for clinical intervention in atherosclerosis therapy., Competing Interests: Declaration of competing interest The authors have declared that no competing interest exists., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Atherosclerosis (AS) is the main pathological basis for the development of cardiovascular diseases. Vascular inflammation is an important factor in the formation of AS, and macrophage pyroptosis plays a key role in AS due to its unique inflammatory response. Guizhitongluo Tablet (GZTLT) has shown clinically effective in treating patients with AS, but its mechanism is elusive., Purpose: This study was to determine the effects of GZTLT on atherosclerotic vascular inflammation and pyroptosis and to understand its underlying mechanism., Materials and Methods: The active constituents of GZTLT were analysed by means of UPLC-HRMS. In vivo experiments were performed using ApoE -/- mice fed a high fat diet for 8 weeks, followed by treatment with varying concentrations of GZTLT orally by gavage and GsMTx4 (GS) intraperitoneally and followed for another 8 weeks. Oil red O, Haematoxylin-eosin (HE) and Masson staining were employed to examine the lipid content, plaque size, and collagen fibre content of the mouse aorta. Immunofluorescence staining was utilised to identify macrophage infiltration, as well as the expression of Piezo1 and NLRP3 proteins in aortic plaques. The levels of aortic inflammatory factors were determined using RT-PCR and ELISA. In vitro, foam cell formation in bone marrow-derived macrophages (BMDMs) was observed using Oil Red O staining. Intracellular Ca 2+ measurements were performed to detect the calcium influx in BMDMs, and the expression of NLRP3 and its related proteins were detected by Western blot., Results: The UPLC-HRMS analysis revealed 31 major components of GZTLT. Our data showed that GZTLT inhibited aortic plaque formation in mice and increased plaque collagen fibre content to stabilise plaques. In addition, GZTLT could restrain the expression of serum lipid levels and suppress macrophage foam cell formation. Further studies found that GZTLT inhibited macrophage infiltration in aortic plaques and suppressed the expression of inflammatory factors. It is noteworthy that GZTLT can restrain Piezo1 expression and reduce Ca 2+ influx in BMDMs. Additionally, we found that GZTLT could regulate NLRP3 activation and pyroptosis by inhibiting Piezo1., Conclusion: The present study suggests that GZTLT inhibits vascular inflammation and macrophage pyroptosis through the Piezo1/NLRP3 signaling pathway, thereby delaying AS development. Our finding provides a potential target for AS treatment and drug discovery., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier GmbH.)

Ethnopharmacological Relevance: Huanglian Jiedu Decoction (HLJDD) is a Chinese medicine with a long history of therapeutic application. It is widely used in treating atherosclerosis (AS) in Chinese medicine theory and clinical practice. However, the mechanism of HLJDD in treating AS remains unclear., Aim of the Study: To investigate the efficacy and mechanism of HLJDD in treating AS., Materials and Methods: AS was induced on high-fat diet-fed ApoE -/- mice, with the aorta pathological changes evaluated with lipid content and plaque progression. In vitro, foam cells were induced by subjecting primary mouse aortic vascular smooth muscle cells (VSMCs) to oxLDL incubation. After HLJDD intervention, VSMCs were assessed with lipid stack, apoptosis, oxidative stress, and the expression of foam cell markers. The effects of P2RY12 were tested by adopting clopidogrel hydrogen sulfate (CDL) in vivo and transfecting P2RY12 over-expressive plasmid in vitro. Autophagy was inhibited by Chloroquine or transfecting siRNA targeting ATG7 (siATG7). The mechanism of HLJDD treating atherosclerosis was explored using network pharmacology and validated with molecular docking and co-immunoprecipitation., Results: HLJDD exhibited a dose-dependent reduction in lipid deposition, collagen loss, and necrosis within plaques. It also reversed lipid accumulation and down-regulated the expression of foam cell markers. P2RY12 inhibition alleviated AS, while P2RY12 overexpression enhanced foam cell formation and blocked the therapeutic effects of HLJDD. Network pharmacological analysis suggested that HLJDD might mediate PI3K/AKT signaling pathway-induced autophagy. P2RY12 overexpression also impaired autophagy. Similarly, inhibiting autophagy counteracted the effect of CDL, exacerbated AS in vivo, and promoted foam cell formation in vitro. However, HLJDD treatment mitigated these detrimental effects by suppressing the PI3K/AKT signaling pathway. Immunofluorescence and molecular docking revealed a high affinity between P2RY12 and PIK3CB, while co-immunoprecipitation assays illustrated their interaction., Conclusions: HLJDD inhibited AS in vivo and foam cell formation in vitro by restoring P2RY12/PI3K/AKT signaling pathway-suppressed autophagy. This study is the first to reveal an interaction between P2RY12 and PI3K3CB., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

In our search for bioactive components, various chromatographic separations of the organic fractions from Filipendula glaberrima leaves led to the isolation of a new ellagitannin and a triterpenoid, along with 26 known compounds. The structures of the isolates were determined based on their spectroscopic properties and chemical evidence, which were then evaluated for their antioxidant activities, inhibitory activities on 3-hydroxy-3-methylglutaryl-coenzyme A reductase, and foam cell formation in THP-1 cells to prevent atherosclerosis. Rugosin B methyl ester ( 1 ) showed the best HMG-CoA reductase inhibition and significantly reduced ox-low-density lipoprotein-induced THP-1 macrophage-derived foam cell formation at 25 µM. In addition, no cytotoxicity was observed in THP-1 cells at 50 μg/mL of all extracts in the macrophage foam cell formation assay. Therefore, F. glaberrima extract containing 1 is promising in the development of dietary supplements due to its potential behavior as a novel source of nutrients for preventing and treating atherosclerosis.

Atherosclerosis is a dominant cause of cardiovascular disease. Accumulation of low-density lipoproteins (LDL), formation of foam cells, and endothelial dysfunction within the arterial intima contribute to atherosclerotic plaque formation. Soy consumption is thought to have positive effect on the prevention of atherosclerosis. Therefore, in the present study, a novel soybean polypeptide dglycin was purified and characterized. Oral administration of 20 mg/g.d dglycin reduced 47.6 % lesion area, and 49.1 % lipid deposition in the atherosclerotic plaques in aortic roots in ApoE -/- mice. In addition, it decreased the levels of 26.0 % plasma low-density lipoprotein, 27.2 % triglyceride, 40.1 % cholesterol, 25.1 % malondialdehyde and 24.2 % tumor necrosis factor-alpha (TNFα). In vitro experiments revealed that dglycin inhibited inflammatory cytokine secretion from aortic endothelial cells via the inhibition of NF-κB signaling. Furthermore, it inhibited reactive oxygen species generation, subsequently enhanced cell viability, and protected aortic endothelial cells from necrosis and apoptosis via mitochondrial function improvement. On the other hand, dglycin prevented the uptake of oxidized LDL by macrophages via suppressing the expression of scavenger receptor class A1, which suggested that dglycin prevented foam cell formation. Therefore, dglycin alleviated the early-stage of atherosclerosis via depressing inflammation, lipid deposition, protecting aortic endothelial cells and preventing foam cell formation., Competing Interests: Declaration of competing interest The authors declare that they have no conflicting interests., (Copyright © 2023. Published by Elsevier B.V.)

Cutaneous xanthoma consist of foam cells that originate from monocytes or macrophages and accumulate in perivascular areas of the skin. The main component of these cells is oxidized low-density lipoprotein (oxLDL). In this study, we show that mast cells surround the accumulated foam cells, suggesting their involvement in xanthoma formation. Coculture of THP-1 or U937 monocytes with the human mast cell line LUVA upregulated their uptake of oxLDL. Positive staining for intracellular cell adhesion molecule-1 (ICAM-1) at the borders between mast cells and foam cells was seen in pathological specimens of the most common cutaneous xanthoma, xanthelasma palpebrarum, and in cocultures. In the latter, ICAM1 messenger RNA levels were upregulated. The administration of anti-ICAM-1 blocking antibody inhibited the increase in oxLDL uptake by THP-1 or U937 monocytes cocultured with LUVA. Taken together, these results suggest a role for mast cells in the formation of xanthelasma palpebrarum and the involvement of ICAM-1 in this process., (© 2023 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

In atherosclerosis, macrophage-derived foam cell formation is considered to be a hallmark of the pathological process; this occurs via the uptake of modified lipoproteins. In the present study, we aim to determine the role of transaldolase in foam cell formation and atherogenesis and reveal the mechanisms underlying its role. Bone marrow-derived macrophages (BMDMs) isolated from mice successfully form foam cells after treatment with oxidized low-density lipoprotein (80 μg/mL). Elevated transaldolase levels in the foam cell model are assessed by quantitative polymerase chain reaction and western blot analysis. Transaldolase overexpression and knockdown in BMDMs are achieved via plasmid transfection and small interfering RNA technology, respectively. We find that transaldolase overexpression effectively attenuates, whereas transaldolase knockdown accelerates, macrophage-derived foam cell formation through the inhibition or activation of cholesterol uptake mediated by the scavenger receptor cluster of differentiation 36 (CD36) in a p38 mitogen-activated protein kinase (MAPK) signaling-dependent manner. Transaldolase-mediated glutathione (GSH) homeostasis is identified as the upstream regulator of p38 MAPK-mediated CD36-dependent cholesterol uptake in BMDMs. Transaldolase upregulates GSH production, thereby suppressing p38 activity and reducing the CD36 level, ultimately preventing foam cell formation and atherosclerosis. Thus, our findings indicate that the transaldolase-GSH-p38-CD36 axis may represent a promising therapeutic target for atherosclerosis.

Aims: Atherosclerosis is a huge threaten to the human health, C1q/TNF-related protein 9 (CTRP9) has been previously reported possessing vascular protective functions. Our study is aimed to reveal the mechanism of the regulative effects of CTRP9 on the foam cell formation., Methods and Results: Primary human macrophages were isolated from human monocytes donated by healthy volunteers. CCK-8 assay was performed for determining the cell viability. Oil Red O staining was employed for measuring the lipid accumulation. Cholesterol ester and cholesterol concentration were detected by commercial kits for evaluating the intracellular cholesterol. Ubiquitination assay was performed to reveal the ubiquitination level of CD36, cycloheximide assay was applied for determining the half-life of CD36 protein. Quantitative real-time PCR and western blot assays were performed for detecting the mRNA and protein expression. Pre-treatment with CTRP9 in primary human macrophages markedly suppressed the cholesterol accumulation concentration after oxidized low-density lipoprotein treatment. CD36 was significantly increased after oxidized low-density lipoprotein exposure while was reduced by CTRP9 treatment. Up-regulation of CD36 significantly reversed the CTRP9-mediated protective effects in foam cells. The differential expression levels of several deubiquitinating enzymes preliminarily indicated that USP11 was obviously decreased after CTRP9 treatment. USP11 knockdown decreased the CD36 protein expression and pre-treatment with 10 μg/mL MG132 significantly maintained the CD36 level from USP11 knock down. Up-regulation of CD36 reversed the alterations on the cholesterol metabolism caused by CTRP9 or USP11 knockdown., Conclusions: CTRP9 regulates the USP11/CD36 axis to protect the macrophages form transforming into foam cells by suppressing intracellular lipid and cholesterol accumulation, which is a potential therapeutic agent for atherosclerosis., (© 2023 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Atherosclerosis is a complex inflammatory disease that affects the arteries and can lead to severe complications such as heart attack and stroke. Macrophages, a type of immune cell, play a crucial role in atherosclerosis initiation and progression. Emerging studies revealed that ion channels regulate macrophage activation, polarization, phagocytosis, and cytokine secretion. Moreover, macrophage ion channel dysfunction is implicated in macrophage-derived foam cell formation and atherogenesis. In this context, exploring the regulatory role of ion channels in macrophage function and their impacts on the progression of atherosclerosis emerges as a promising avenue for research. Studies in the field will provide insights into novel therapeutic targets for the treatment of atherosclerosis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Wu, Singla, Liu and Hong.)

To explore the sesquiterpenoids in Curcuma longa L. and their activity related to anti-atherosclerosis. The chemical compounds of the rhizomes of C. longa were separated and purified by multiple chromatography techniques. Their structures were established by a variety of spectroscopic experiments. The absolute configurations were determined by comparing experimental and calculated NMR chemical shifts and electronic circular dichroism (ECD) spectra. Their anti-inflammatory effects and inhibitory activity against macrophage-derived foam cell formation were evaluated by lipopolysaccharide (LPS) and oxidized low-density lipoprotein (ox-LDL)-injured RAW264.7 macrophages, respectively. This study resulted in the isolation of 10 bisabolane-type sesquiterpenoids ( 1 - 10 ) from C. longa , including two pairs of new epimers (curbisabolanones A-D, 1 - 4 ). Compound 4 significantly inhibited LPS-induced nitric oxide (NO), interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2) production in RAW264.7 cells. Furthermore, compound 4 showed inhibitory activity against macrophage-derived foam cell formation, which was represented by markedly reducing ox-LDL-induced intracellular lipid accumulation as well as total cholesterol (TC), free cholesterol (FC), and cholesterol ester (CE) contents in RAW264.7 cells. These findings suggest that bisabolane-type sesquiterpenoids, one of the main types of components in C. longa , have the potential to alleviate the atherosclerosis process by preventing inflammation and inhibiting macrophage foaming., Competing Interests: The authors declare no conflict of interest.

Atherosclerotic morbidity is significantly higher in the diabetic population. Hyperglycemia, a typical feature of diabetes, has been proven to accelerate foam cell formation. However, the molecular mechanisms behind this process remain unclear. In this study, LPS and IFN-γ were used to convert THP-1-derived macrophages into M1 macrophages, which were then activated with ox-LDL in either high glucose or normal condition. We identified lipids within macrophages by Oil red O staining and total cholesterol detection. The genes involved in lipid absorption, efflux, inflammation, and metabolism were analyzed using qRT-PCR. The mechanisms of high glucose-induced foam cell formation were further investigated through metabolomics and transcriptomics analysis. We discovered that high glucose speed up lipid accumulation in macrophages (both lipid droplets and total cholesterol increased), diminished lipid efflux (ABCG1 down-regulation), and aggravated inflammation (IL1B and TNF up-regulation). Following multi-omics analysis, it was determined that glucose altered the metabolic and transcriptional profiles of macrophages, identifying 392 differently expressed metabolites and 293 differentially expressed genes, respectively. Joint pathway analysis suggested that glucose predominantly disrupted the glycerolipid, glycerophospholipid, and arachidonic acid metabolic pathways in macrophages. High glucose in the glyceride metabolic pathway, for instance, suppressed the transcription of triglyceride hydrolase (LIPG and LPL), causing cells to deposit excess triglycerides into lipid droplets and encouraging foam cell formation. More importantly, high glucose triggered the accumulation of pro-atherosclerotic lipids (7-ketocholesterol, lysophosphatidylcholine, and glycerophosphatidylcholine). In conclusion, this work elucidated mechanisms of glucose-induced foam cell formation via a multi-omics approach., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Atherosclerosis is driven by synergistic interactions between pathological biomechanical and lipid metabolic factors. Long noncoding RNAs (LncRNAs) have been implicated in atherogenesis. The purpose of this study was to investigate the potential mechanism of lncRNA AI662270 on macrophage cholesterol transport in atherosclerosis., Methods: Apolipoprotein E deficiency (ApoE -/- ) mice were fed a high fat diet for 16 weeks to construct atherosclerotic model, and the mice were injected with recombinant lentivirus carrying AI662270 gene to overexpress AI662270. Macrophages were cleared by liposomal clondronate in vivo. Fundamental experiments and functional assays, hematoxylin and eosin staining, oil red O staining and others, were performed to evaluate the function of AI662270 on atherogenesis. Peritoneal macrophages were treated with oxidized low density lipoprotein (ox-LDL) to simulate in vitro model. Mechanism assays, RNA-interacting protein immunoprecipitation, RNA-protein pulldown and others, were performed to study the regulatory mechanism of AI662270 in macrophages., Results: The novel AI662270 was mainly enriched in macrophages, but not in endothelial cells, smooth muscle cells and fibroblasts of mouse atherosclerotic lesions and was upregulated by ox-LDL. Overexpression of AI662270 resulted in lipid accumulation, larger atherosclerotic plaques and cardiac dysfunction in vivo. After macrophages were removed, the pro-atherogenic effect of AI662270 disappeared. Downregulation of AI662270 in macrophages protected against foam cell formation by potentiating cholesterol efflux and reducing intracellular total cholesterol. The opposite effect was observed in macrophage-specific AI662270-overexpressed cells in vitro. AI662270 bound to adenosine triphosphate-binding cassette transporter A1 (Abca1) responsible for regulating cholesterol efflux in macrophages. Forced expression of AI662270 in macrophages decreased Abca1 expression. The reverse occurred when expression of AI662270 was repressed., Conclusion: These findings reveal an essential role for AI662270 in atherosclerosis progression by regulating cholesterol efflux from macrophages., (© 2023. The Author(s).)

Phagocytosis of oxidized low-density lipoprotein (OxLDL) by macrophages yields "foam cells" and serves as a hallmark of atherosclerotic lesion. Adipsin is a critical component of the complement activation pathway. Recent evidence has indicated an obligatory role for Adipsin in pathological models including ischemia-reperfusion and sepsis. Adipsin levels are significantly decreased in patients with asymptomatic carotid atherosclerosis, implying the role for Adipsin as a potential marker of asymptomatic carotid atherosclerosis. This study was designed to evaluate the role for Adipsin in atherosclerosis and the mechanisms involved using both in vivo and in vitro experiments. ApoE -/- /AdipsinTg mice were constructed and were fed a high-fat diet for 12 weeks. Compared with ApoE -/- mice, area of the sclerotic plaques was reduced, along with lower macrophage deposition within the plaque in ApoE -/- /AdipsinTg mice. RAW264.7 cells and bone marrow-derived macrophages (BMDMs) were stimulated with oxLDL (50 μg/ml). Adenovirus vectors containing the Adipsin gene were transfected into macrophages. Lipid accumulation was observed by Oil red O staining. Western blot and reverse transcription-polymerase chain reaction data revealed that Adipsin overexpression inhibited oxLDL-induced lipid uptake and foam cell formation and upregulation of CD36 and PPARγ in Ad-Adipsin-transfected macrophages. In addition, the PPARγ-specific agonist GW1929 reversed Adipsin overexpression-evoked inhibitory effect on lipid uptake. These results demonstrate unequivocally that Adipsin inhibits lipid uptake in a PPARγ/CD36-dependent manner and prevents the formation of foam cells, implying that Adipsin may be a potential therapeutic target against atherosclerosis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Ractopamine, a synthetic β-adrenoreceptor agonist, is used as an animal feed additive to increase food conversion efficiency and accelerate lean mass accretion in farmed animals. The U.S. Food and Drug Administration claimed that ingesting products containing ractopamine residues at legal dosages might not cause short-term harm to human health. However, the effect of ractopamine on chronic inflammatory diseases and atherosclerosis is unclear. Therefore, we investigated the effects of ractopamine on atherosclerosis and its action mechanism in apolipoprotein E-null (apoe -/- ) mice and human endothelial cells (ECs) and macrophages. Daily treatment with ractopamine for four weeks increased the body weight and the weight of brown adipose tissues and gastrocnemius muscles. However, it decreased the weight of white adipose tissues in apoe -/- mice. Additionally, ractopamine exacerbated hyperlipidemia and systemic inflammation, deregulated aortic cholesterol metabolism and inflammation, and accelerated atherosclerosis. In ECs, ractopamine treatment induced endothelial dysfunction and increased monocyte adhesion and transmigration across ECs. In macrophages, ractopamine dysregulated cholesterol metabolism by increasing oxidized low-density lipoprotein (oxLDL) internalization and decreasing reverse cholesterol transporters, increasing oxLDL-induced lipid accumulation. Collectively, our findings revealed that ractopamine induces EC dysfunction and deregulated cholesterol metabolism of macrophages, which ultimately accelerates atherosclerosis progression., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

CD226 is a costimulatory molecule that regulates immune cell functions in T cells, natural killer cells, and macrophages. Because macrophage-derived foam cell formation is a crucial factor contributing to the development of atherosclerosis, we aimed to evaluate the potential roles of CD226 in the pathogenesis of atherosclerosis. The effects of CD226 on atherosclerosis were investigated in CD226 and apolipoprotein E double-knockout (CD226 -/- ApoE -/- ) mice fed with a high-cholesterol atherogenic diet. CD226 expression in macrophages was evaluated using flow cytometry. Histopathological analysis was performed to evaluate the atherosclerotic lesions. Inflammatory cell infiltration was detected using immunofluorescence staining. Bone marrow-derived macrophages (BMDMs) and peritoneal macrophages (PEMs) were isolated from the mice and used to explore the mechanism in vitro. The in vivo results indicated that CD226 knockdown protected against atherosclerosis in ApoE -/- mice, evidenced by reduced plaque accumulation in the brachiocephalic artery, aortic roots, and main aortic tree. CD226 gene-deficient macrophages showed reduced foam cell formation under ox-low density lipoprotein stimulation compared with wild-type (WT) cells. CD226 deficiency also decreased the expression of CD36 and scavenger receptor (SR)-A (responsible for lipoprotein uptake) but increased the expression of ATP-binding cassette transporter A1 and G1 (two transporters for cholesterol efflux). Therefore, loss of CD226 hinders foam cell formation and atherosclerosis progression, suggesting that CD226 is a promising new therapeutic target for atherosclerosis., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Ethnopharmacological Relevance: The dried pericarp of Citrus reticulata Blanco (CP) occupies an important position in the history of clinical applications of traditional Chinese medicine (TCM). In traditional use, CP is used to treat diseases related to the digestive, respiratory, and cardiovascular systems, as well as to regulate Qi and promote blood circulation throughout the body. In China, a special cultivar of CP named Guang Chen Pi (GCP) which is collected exclusively from Citrus reticulata Blanco's cultivars 'Chachi', is considered to be the best CP with high medicinal and dietary value. Modern pharmacology shows that CP has high effect on regulating metabolic disorders and cardiovascular systems diseases. Atherosclerosis (AS) is not only an inflammatory disease but also cardiovascular lipid metabolism disorder. Foam cells formation is the hallmark of AS. Several reports indicated that CP can mitigate the development of AS, but involved signaling pathway and its role in foam cell formation is unclear. Since the main components of GCP has protective effects in cardiovascular diseases, we evaluated its effect of inhibiting foam cell formation to support the traditional usage of GCP., Aim of the Study: The objective of this study aims to investigate the effects of GCP on suppressing RAW264.7 foam cell formation and anti-inflammatory in vitro., Materials and Methods: To evaluate the anti-foam cell formation and anti-inflammatory activity of GCP, oxidized low-density lipoprotein (ox-LDL) induced RAW264.7 macrophages model was involved. Meantime, foam cell developing status was also closely monitored. RT-qPCR and Western blot were then applied to further investigate receptors in associated signaling pathways., Results: GCP shown inhibitory effect on macrophage-derived foam cell formation in Oil Red O staining analysis, which was further confirmed by flow cytometry of Dil-ox-LDL staining and TG and TC analysis. The HDL-mediated cholesterol efflux was also promoted by GCP. Mechanistic studies showed that GCP significantly down-regulate SRA1 and CD36 protein expression, while significantly increasing the expression of PPARγ, LXRα, SRB1 and ABCG1. Also, GCP reduced ox-LDL-induced inflammatory factors level, and inhibited phosphorylation of p38 MAPK, ERK1/2, JNK1/2, NF-κB p65 and IKKα/β., Conclusions: GCP exhibited anti-atherogenic ability by interfering RAW264.7 foam cell formation, through inhibiting lipid uptake and promoting HDL-mediated cholesterol. PPARγ-LXRα-ABCG1/SRB1 pathway and its anti-inflammatory effect may involve. This proposed anti-foam cell formation activity is expected to provide new insight on comprehensive utilization of GCP., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Atherosclerosis, accompanied by inflammation and metabolic disorders, is the primary cause of clinical cardiovascular death. In recent years, unhealthy lifestyles (e.g., sedentary lifestyles) have contributed to a worldwide epidemic of atherosclerosis. Exercise is a known treatment of atherosclerosis, but the precise mechanisms are still unknown. Here, we show that 12 weeks of regular exercise training on a treadmill significantly decreased lipid accumulation and foam cell formation in ApoE -/- mice fed with a Western diet, which plays a critical role in the process of atherosclerosis. This was associated with an increase in β-hydroxybutyric acid (BHB) levels in the serum. We provide evidence that BHB treatment in vivo or in vitro increases the protein levels of cholesterol transporters, including ABCA1, ABCG1, and SR-BI, and is capable of reducing lipid accumulation. It also ameliorated autophagy in macrophages and atherosclerosis plaques, which play an important role in the step of cholesterol efflux. Altogether, an increase in serum BHB levels after regular exercise is an important mechanism of exercise inhibiting the development of atherosclerosis. This provides a novel treatment for atherosclerotic patients who are unable to undertake regular exercise for whatever reason. They will gain a benefit from receiving additional BHB.

Background: The production of lipid-laden cells in macrophages after significant ingestion of oxidized low-density lipoprotein is considered the most critical phase in the creation of atherosclerotic lesions, which is known as foam cell formation. Targeting foam cell development to find a potential therapeutic strategy for the management of atherosclerosis has yielded numerous promising outcomes. Multiple variables influence foam cell growth, including scavenger receptor expression, cholesterol transporter expression acyl CoA: cholesterol acyltransferase activity, and neutral cholesteryl ester hydrolase activity. Plants used during herbal therapy have been shown to assist with a variety of ailments., Result: In this study, we found medicinal plants and their bioactive components suppress foam cell formation in a variety of ways; some inhibit cholesterol transporter and lectin-like oxidized low-density lipoprotein receptor-1 upregulation, while others inhibit the function of acyl CoA: cholesterol acyltransferase activity, and neutral cholesteryl ester hydrolase activity., Conclusion: Recent study findings related to the synthesis of the new active component from plant sources by focusing on the typical process involved in the generation of foam cells. We're also looking at using a cellular target-based therapeutic approach to generate novel plant-based medications for the cure of atherosclerosis., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

Deciphering the molecular and cellular processes involved in foam cell formation is critical for us to understand the pathogenesis of atherosclerosis. Nuclear factor of activated T cells (NFAT) is a transcription factor originally identified as a key player in the differentiation of T cells and maturation of immune system. Nowadays it has been brought into attention that NFAT also regulates multiple pathophysiological processes and targeted intervention in NFAT may be effective in the treatment of some cardiovascular diseases. However, whether NFAT is involved in foam cell formation remains elusive. NFAT in human monocyte-derived macrophage was activated by ox-LDL and translocated from the cytoplasm to the nucleus. NFAT then directly bound to peroxisome proliferator-activated receptor γ (PPARγ) in the nucleus and negatively regulated its transcriptional activity. NFATc2 knockdown or NFAT inhibitor 11R-VIVIT increased cholesterol efflux (by activating PPARγ-LXRα-ABCA1 cascade) and reduced the uptake of modified lipoprotein (in a PPARγ-independent way) in macrophage, thus prevented foam cell formation. Besides, 11R-VIVIT also exerted a protective role in the development of atherosclerosis in western diet-fed ApoE -/- mice. These results suggest NFAT inhibition as a potential therapeutic strategy in atherosclerosis., (© 2021 Federation of American Societies for Experimental Biology.)

Atherosclerosis is the underlying contributing factor of cardiovascular disease, which is a process of inflammation and lipid-rich lesion. Macrophage-derived foam cell is a key hallmark of atherosclerosis and connected with various factors of lipid metabolism. Here, we showed that fatty acid binding protein 3 (FABP3) was upregulated in the aorta of ApoE -/- mice with high-fat-diet (HFD) feeding. Knockdown of FABP3 in HFD-fed ApoE -/- mice notably facilitated cholesterol efflux, inhibited macrophage foam cell formation, and thus prevented atherogenesis. Furthermore, FABP3 silencing decreased the expression of peroxisome proliferator-activated receptor γ (PPARγ). Mechanistic studies had disclosed the involvement of PPARγ signaling in balancing cholesterol uptake and efflux and diminishing foam cell formation. These findings firstly revealed an anti-atherogenic role of FABP3 silencing in preventing foamy macrophage formation partly through PPARγ, which might be a beneficial approach for therapying atherosclerosis., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Atherosclerosis, as a chronic inflammatory disease within the arterial wall, is a leading cause of morbidity and mortality worldwide due to its role in myocardial infarction, stroke and peripheral artery disease. Additional evidence is emerging that the angiopoietin-like (ANGPTL) family of proteins participate in the pathology of this disease process via endothelial dysfunction, inflammation, dyslipidemia, calcification, foam cell formation and platelet activation. This review summarizes current knowledge on the ANGPTL family of proteins in atherosclerosis related pathological processes. Moreover, the potential value of ANGPTL family proteins as predictive biomarkers in atherosclerosis is discussed. Given the attractive role of ANGPTL3, ANGPTL4, ANGPTL8 in atherosclerotic dyslipidemia via regulation of lipoprotein lipase (LPL), antisense oligonucleotide or/and monoclonal antibody-based inactivation of these proteins represent potential atherosclerotic therapies., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Engelhardia roxburghiana Wall. is a traditional Chinese medicine used for treating cardiovascular diseases. Our previous study has implicated potential effects of total flavonoids of Engelhardia roxburghiana Wall. (TFER) against hyperlipidemia. The aim of the study is to uncover the effects and underlying mechanisms of TFER on foam cells formation after atherosclerosis. We used high fat diet (HFD) induced Apoe-/- mice and oxidized density lipoprotein (ox-LDL) induced THP-1 cells to mimic process of atherosclerosis in vivo and in vitro, respectively. Lipid accumulation, inflammation response, autophagosomes formation and expressions of autophagy related target genes were assessed. Our present study demonstrated TFER (500 mg/kg) alleviated macrophage infiltration and lipid accumulation in thoracic aortas of HFD-treated mice. In ox-LDL-treated THP-1 cells, MDC staining and Western blot analysis all indicated that the TFER (200 μg/ml) reduced foam cells formation and IL-1β releasing, activated autophagy through suppressing AKT/mTOR signaling, significantly regulating expressions of AKT, p-AKT, mTOR, p-mTOR, Beclin 1, LC3-II, p62. It is suggested that TFER alleviated atherosclerosis progression in vivo and in vitro through reducing foam cells formation and inflammatory responses, and the possible mechanism may be due to the activation of macrophage autophagy by inhibiting AKT and mTOR phosphorylation., (© 2021 Wiley-VHCA AG, Zurich, Switzerland.)

Background: Premature atherosclerosis occurs in patients with SLE; however, the mechanisms remain unclear. Both mitochondrial machinery and proinflammatory cytokine interferon alpha (IFN-α) potentially contribute to atherogenic processes in SLE. Here, we explore the roles of the mitochondrial protein cytidine/uridine monophosphate kinase 2 (CMPK2) in IFN-α-mediated pro-atherogenic events., Methods: Foam cell measurements were performed by oil red O staining, Dil-oxLDL uptake and the BODIPY approach. The mRNA and protein levels were measured by qPCR and Western blotting, respectively. Isolation of CD4+ T cells and monocytes was performed with monoclonal antibodies conjugated with microbeads. Manipulation of protein expression was conducted by either small interference RNA (siRNA) knockdown or CRISPR/Cas9 knockout. The expression of mitochondrial reactive oxygen species (mtROS) was determined by flow cytometry and confocal microscopy., Results: IFN-α enhanced oxLDL-induced foam cell formation and Dil-oxLDL uptake by macrophages. In addition to IFN-α, several triggers of atherosclerosis, including thrombin and IFN-γ, can induce CMPK2 expression, which was elevated in CD4+ T cells and CD14+ monocytes isolated from SLE patients compared to those isolated from controls. The analysis of cellular subfractions revealed that CMPK2 was present in both mitochondrial and cytosolic fractions. IFN-α-induced CMPK2 expression was inhibited by Janus kinase (JAK)1/2 and tyrosine kinase 2 (Tyk2) inhibitors. Both the knockdown and knockout of CMPK2 attenuated IFN-α-mediated foam cell formation, which involved the reduction of scavenger receptor class A (SR-A) expression. CMPK2 also regulated IFN-α-enhanced mtROS production and inflammasome activation., Conclusions: The study suggests that CMPK2 plays contributing roles in the pro-atherogenic effects of IFN-α.

Foam cell formation and inflammation in macrophages contribute to the development of atherosclerosis (AS). Clematichinenoside AR (AR) is a major active ingredient extracted from the traditional Chinese herb Clematis chinensis and has potent pharmacological effects on various diseases, including AS. However, little is known about the exact role and mechanism of AR in AS. RAW264.7 macrophages were exposed to oxidized low-density lipoprotein (ox-LDL) to induce AS in vitro. Cell viability was assessed by the CCK-8 assay. Foam cell formation was detected by Oil Red staining. Cholesterol levels were determined by corresponding commercial kits. The expression of inflammatory cytokines was detected by ELISA. Western blot and immunofluorescence assays were employed to detect the expression of corresponding genes. The results indicated that AR treatment inhibited the formation of foam cells and cholesterol accumulation but promoted cholesterol efflux by upregulating ABCA1/ABCG1 in ox-LDL-induced RAW264.7 macrophages. In addition, AR decreased the production of inflammatory cytokines by blunting the activation of the NLRP3 inflammasome and inducing autophagy. However, these effects of AR were weakened by the autophagy inhibitor bafilomycin A1 but were similar to those produced by the autophagy activator rapamycin. Collectively, our study provides novel insights into the beneficial effects of AR on promoting cholesterol efflux as well as inhibiting foam cell formation and inflammation by regulating autophagy, thus identifying AR as a promising therapeutic agent for the treatment of AS.

Atherosclerosis is a major cause of human cardiovascular disease, which is the leading cause of mortality around the world. Various physiological and pathological processes are involved, including chronic inflammation, dysregulation of lipid metabolism, development of an environment characterized by oxidative stress and improper immune responses. Accordingly, the expansion of novel targets for the treatment of atherosclerosis is necessary. In this study, we focus on the role of foam cells in the development of atherosclerosis. The specific therapeutic goals associated with each stage in the formation of foam cells and the development of atherosclerosis will be considered. Processing and metabolism of cholesterol in the macrophage is one of the main steps in foam cell formation. Cholesterol processing involves lipid uptake, cholesterol esterification and cholesterol efflux, which ultimately leads to cholesterol equilibrium in the macrophage. Recently, many preclinical studies have appeared concerning the role of non-encoding RNAs in the formation of atherosclerotic lesions. Non-encoding RNAs, especially microRNAs, are considered regulators of lipid metabolism by affecting the expression of genes involved in the uptake (e.g., CD36 and LOX1) esterification (ACAT1) and efflux (ABCA1, ABCG1) of cholesterol. They are also able to regulate inflammatory pathways, produce cytokines and mediate foam cell apoptosis. We have reviewed important preclinical evidence of their therapeutic targeting in atherosclerosis, with a special focus on foam cell formation.

Introduction and Aims: Oxytocin (OT) is a neuropeptide hormone secreted by the posterior pituitary gland. Deficits in OT action have been observed in patients with behavioral and mood disorders, some of which correlate with an increased risk of cardiovascular disease (CVD). Recent research has revealed a wider systemic role that OT plays in inflammatory modulation and development of atherosclerotic plaques. This study investigated the role that OT plays in cholesterol transport and foam cell formation in LPS-stimulated THP-1 human macrophages., Methods: THP-1 differentiated macrophages were treated with media, LPS (100 ng/ml), LPS + OT (10 pM), or LPS + OT (100 pM). Changes in gene expression and protein levels of cholesterol transporters were analyzed by real time quantitative PCR (RT-qPCR) and Western blot, while oxLDL uptake and cholesterol efflux capacity were evaluated with fluorometric assays., Results: RT-qPCR analysis revealed a significant increase in ABCG1 gene expression upon OT + LPS treatment, compared to LPS alone (p = 0.0081), with Western blotting supporting the increase in expression of the ABCG1 protein. Analysis of oxLDL uptake showed a significantly lower fluorescent value in LPS + OT (100pM) -treated cells when compared to LPS alone (p < 0.0001). While not statistically significant (p = 0.06), cholesterol efflux capacity increased with LPS + OT treatment., Conclusion: We demonstrate here that OT can attenuate LPS-mediated lipid accumulation in THP-1 macrophages. These findings support the hypothesis that OT could be used to reduce pro-inflammatory and potentially atherogenic changes observed in patients with heightened CVD risk. This study suggests further exploration of OT effects on monocyte and macrophage cholesterol handling in vivo., (Copyright © 2021. Published by Elsevier Inc.)

Background and Aims: Angiopoietin-like protein 8 (ANGPTL8) is a hormone involved in regulating lipid metabolism. Patients with coronary artery disease have markedly higher plasma levels of ANGPTL8 than controls; however, the role of ANGPTL8 in atherosclerosis has not been explored. Therefore, we explored the effects of ANGPTL8 on atherosclerosis development in a mouse model., Methods: We induced experimental atherosclerosis in ApoE -/- mice ANGPTL8-knockdown. and ANGPTL8-overexpression ApoE -/- mice. We also explored the mechanism using ANGPTL8-overexpression macrophages., Results: ANGPTL8 expression was increased in human and mouse atherosclerotic lesions. ANGPTL8 overexpression promoted the development of atherosclerosis whereas ANGPTL8 knockdown protected against atherosclerosis. Immunofluorescence co-staining results showed that ANGPTL8 was expressed in macrophages in atherosclerotic plaques. Compared with wild type cells, ANGPTL8-overexpressing macrophages, including bone marrow-derived macrophages and Raw 264.7 macrophages, showed enhanced foam cell formation and increased accumulation of cholesterol that was induced by increased uptake and decreased efflux of cholesterol. The results of this study also showed that ANGPTL8 induced the expression of CD36 and scavenger receptor (SR)-A, and inhibited the expression of SR-BI., Conclusions: Our findings demonstrate an unanticipated role of ANGPTL8 in the development of atherosclerosis and regulation of foam cell formation. ANGPTL8 may be a promising new target for atherosclerosis., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)

Vascular inflammation plays a decisive role in the formation of foam cells and in the pathophysiology of atherosclerosis. However, the underlying mechanisms of these processes are not clearly understood. Macrophages engulf oxidized low-density lipoproteins (OxLDLs) via a scavenger receptor (SR), an event that mediates the elaboration of proinflammatory cytokines to initiate necrotic core formation in atherogenic plaques. In this study, we demonstrate that Nitric oxide synthase 1 (NOS1)-derived nitric oxide (NO) promotes OxLDL uptake and enhances the release of proinflammatory cytokines by macrophages. Conversely, we show that NOS1 inhibition by N(G)-nitro-L-arginine methyl ester (L-NAME) suppresses OxLDL uptake and proinflammatory cytokine expression. Current studies indicate that NOS1 plays a crucial role in vascular inflammation and in the progression of atherosclerosis. Therefore, interference with NOS1 enzymatic activity should serve as an effective strategy to reduce foam cell formation and limit the extent of atherosclerotic plaque expansion., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Interleukin-17A (IL-17A), a major effector cytokine secreted by T helper 17 (Th17) cells, is elevated in atherosclerosis lesions. The purpose of this study was to assess the role of IL-17A in the pathogenesis of atherosclerosis. To measure the expression of adhesion molecules, human umbilical vein endothelial cells (HUVECs) and U937 cells were stimulated with IL-17A. Western blot and real-time polymerase chain reaction analyses revealed that intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression in HUVECs, and very late antigen-4 (VLA-4), lymphocyte function-associated antigen-1 (LFA-1) and macrophage-1 antigen (MAC-1) expression in U937 cells was upregulated by IL-17A. Furthermore, IL-17A stimulation resulted in mRNA and protein expression of scavenger receptor (LOX-1) in phorbol 12-myristate 13-acetate (PMA)-activated U937 cells. Oil Red O also demonstrated that IL-17A enhanced foam cell formation by PMA-activated U937 cells induced by oxidized low-density lipoprotein (ox-LDL), and this enhancement of ox-LDL-induced foam cell formation in IL-17A-treated U937 cells was downregulated by transfection of LOX-1 siRNA. These results indicated that IL-17A induced the expression of adhesion molecules, promoted the adherence of monocytes to vascular endothelial cells. IL-17A also stimulated ox-LDL-induced foam cell formation via upregulation of LOX-1 in activated macrophages. IL-17A may be responsible for the pathogenesis of atherosclerosis by inducing the adhesion of leukocytes to vascular endothelium and foam cell formation.

Background: Seroepidemiological studies have highlighted a positive relation between CagA-positive Helicobacter pylori (H. pylori), atherosclerosis and related clinic events. However, this link has not been well validated. The present study was designed to explore the role of H. pylori PMSS1 (a CagA-positive strain that can translocate CagA into host cells) and exosomal CagA in the progression of atherosclerosis., Methods: To evaluate whether H. pylori accelerates or even induces atherosclerosis, H. pylori-infected C57/BL6 mice and ApoE -/- mice were maintained under different dietary conditions. To identify the role of H. pylori-infected gastric epithelial cells-derived exosomes (Hp-GES-EVs) and exosomal CagA in atherosclerosis, ApoE -/- mice were given intravenous or intraperitoneal injections of saline, GES-EVs, Hp-GES-EVs, and recombinant CagA protein (rCagA)., Findings: CagA-positive H. pylori PMSS1 infection does not induce but promotes macrophage-derived foam cell formation and augments atherosclerotic plaque growth and instability in two animal models. Meanwhile, circulating Hp-GES-EVs are taken up in aortic plaque, and CagA is secreted in Hp-GES-EVs. Furthermore, the CagA-containing EVs and rCagA exacerbates macrophage-derived foam cell formation and lesion development in vitro and in vivo, recapitulating the pro-atherogenic effects of CagA-positive H. pylori. Mechanistically, CagA suppresses the transcription of cholesterol efflux transporters by downregulating the expression of transcriptional factors PPARγ and LXRα and thus enhances foam cell formation., Interpretation: These results may provide new insights into the role of exosomal CagA in the pathogenesis of CagA-positive H. pylori infection-related atherosclerosis. It is suggested that preventing and eradicating CagA-positive H. pylori infection could reduce the incidence of atherosclerosis and related events., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Deciphering the molecular and cellular processes involved in foam cell formation is critical to understanding the pathogenesis of atherosclerosis. Interferon regulatory factor 1 (IRF1) was first identified as a transcriptional regulator of type-I interferons (IFNs) and IFN inducible genes. Our study aims to explore the role of IRF1 in atherosclerotic foam cell formation and understand the functional diversity of IRF1 in various cell types contributing to atherosclerosis. Methods : We induced experimental atherosclerosis in ApoE -/- IRF1 -/- mice and evaluated the effect of IRF1 on disease progression and foam cell formation. Results : IRF1 expression was increased in human and mouse atherosclerotic lesions. IRF1 deficiency inhibited modified lipoprotein uptake and promoted cholesterol efflux, along with altered expression of genes implicated in lipid metabolism. Gene expression analysis identified scavenger receptor (SR)-AI as a regulated target of IRF1, and SR-AI silencing completely abrogated the increased uptake of modified lipoprotein induced by IRF1. Our data also explain a mechanism underlying endotoxemia-complicated atherogenesis as follows: two likely pro-inflammatory agents, oxidized low-density lipoprotein (ox-LDL) and bacterial lipopolysaccharide (LPS), exert cooperative effects on foam cell formation, which is partly attributable to a shift of IRF1-Ubc9 complex to IRF1- myeloid differentiation primary response protein 88 (Myd88) complex and subsequent IRF1 nuclear translocation. Additionally, it seems that improved function of vascular smooth muscle cells (VSMCs) also accounts for the diminished and more stable atherosclerotic plaques observed in ApoE -/- IRF1 -/- mice. Conclusions : Our findings demonstrate an unanticipated role of IRF1 in the regulation of gene expression implicated in foam cell formation and identify IRF1 activation as a new risk factor in the development, progression and instability of atherosclerotic lesions., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

Purpose of Review: Summarize of the reports on antioxidants especially from herbal sources which battle oxidative stress might be proficient to forestall and repair the free radical-prompted vascular damages in overseeing of atherosclerosis., Recent Findings: Atherosclerosis is the one of the fundamental reason for hypertension, stroke, myocardial localized necrosis, and numerous other cardiovascular illnesses. Atherosclerosis associated path physiological factors like hypercholesterolemia, hypertension, diabetes mellitus, and smoking actuates oxidative stress which are characterized by excessive oxidation and improper exclusion. The herbal plant-based antioxidant agents are effective towards the management/treatment of atherosclerosis by different ways like, by diminishing the oxidation of low-density lipoproteins, diminishing the cell proliferation, restraining the foam cell arrangement, and advancing the reverse cholesterol transport, down regulation of pro-atherogenic genes, and inflammatory mediators. This review is a critical analysis about the role of oxidative stress in atherogenesis and furthermore outlines the ongoing study/examination done on the management of atherosclerosis by utilizing herbal antioxidant agents.

Inflammation, oxidative stress, and dyslipidemia are major factors in the pathogenesis of atherosclerosis. Andrographolide, a bioactive component of Andrographis paniculata, has several biological activities, including anti-inflammatory, antioxidant, and anticancer effects. This study shows that andrographolide downregulates the oxidized low-density lipoprotein (oxLDL)-induced expression of the pro-inflammatory molecules monocyte chemotactic protein (MCP)-1 and interleukin (IL)-6 and blocks the nuclear factor-κB signaling pathway in macrophages. Additionally, andrographolide treatment decreased reactive oxygen species (ROS) generation in oxLDL-induced macrophages, indicating that the compound can decrease oxidative stress. The results also suggest that andrographolide suppresses oxLDL-induced foam cell formation and inhibits oxLDL-induced CD36 expression in vitro. Furthermore, in vivo studies have indicated that andrographolide treatment ameliorates atherosclerosis pathogenesis in apolipoprotein E knockout mice. Therefore, by suppressing inflammation, ROS generation, and foam cell formation, andrographolide may ameliorate the progression of atherosclerosis, suggesting its potential as a therapeutic drug for the prevention and/or treatment of this disease.

Background: Atherosclerosis is characterized by chronic inflammation in vascular wall. Previous studies suggest that Kuwanon G (KWG) exerts anti-inflammatory activities. However, the effect of KWG on atherosclerosis remains unexplored., Aims: To explore whether KWG affects macrophage foam cell formation in vitro and atherogenesis in vivo., Methods: RAW 264.7 macrophages were stimulated with ox-LDL for 24h to induce foam cell formation and treated with KWG. Foam cell formation was determined by ORO staining and enzymatic analysis. Pro-inflammatory cytokines mRNA levels were tested by Real-time PCR method. Further molecular mechanism was investigated using Western blot. In vivo, ApoE -/- mice were fed with high-fat diet and intraperitoneally injected with KWG. Atherosclerotic lesion was accessed by H&E and ORO staining. Plaque composition was evaluated by immunohistochemistry and Sirius Red staining. Serum lipid profile and inflammatory cytokines were evaluated by enzymatic method and ELISA., Results: KWG significantly decreased intracellular lipid accumulation and inflammatory cytokines mRNA levels in macrophages through enhancing LXRα-ABCA1/ABCG1 pathway and inhibiting NFκB activation. Administrated with KWG remarkably reduced the atherosclerotic lesion areas and macrophage content in the plaque of high-fat diet fed ApoE -/- mice. KWG also reduced hyperlipidemia and serum inflammatory cytokines in vivo., Conclusion: Taken together, these data highlight that KWG can attenuate atherosclerosis through inhibiting foam cell formation and inflammatory response., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Atherosclerosis is a chronic inflammatory cardiovascular disease with high mortality worldwide. Tofacitinib (CP-690,550), an oral small-molecule Janus kinase inhibitor, has been shown to be effective in the treatment of rheumatoid arthritis, autoimmune encephalomyelitis and ulcerative colitis. However, its protective effect against atherosclerosis remains poorly understood. The aim of the present study was to evaluate the effects of Tofacitinib on atherogenic diet (ATD)-induced atherosclerosis using apolipoprotein E deficient (apoE-/-) mice. Atherosclerosis-prone apoE-/- mice were fed with ATD and treated with or without Tofacitinib through intragastrical administration (10 mg kg -1 day -1 ) for 8 weeks. Our results showed that Tofacitinib did not change plasma lipids, while significantly reduced the levels of plasma pro-inflammatory cytokines IL-6 and TNF-α. It also significantly attenuated atherosclerotic plaque lesion in the aortic root and macrophages contained in plaque as shown with Mac2 immuno-staining. Peritoneal macrophages (PMC) were separated from apoE-/- mice fed with 8-week ATD, and then subjected to inflammation tests. Flow cytometry analysis of F4/80 and CD206 and mRNA levels of M1 and M2 macrophages markers showed that M1 macrophages decreased while M2 macrophages increased in Tofacitinib treated group. Expressions of other inflammatory genes also indicated an anti-inflammatory status in mice treated with Tofacitinib. Ox-LDL was used to induce foam cell formation from PMC in wild type mice, and the results displayed a reduced formation of foam cells and decreased inflammation in mice with Tofacitinib administration (1 μM). The mRNA and protein levels of ATP binding cassette subfamily A member 1 (ABCA1), a key gene involved in cholesterol efflux, remarkably increased, while it was absence of alterations in scavenger receptors expression. Therefore, we demonstrated that Tofacitinib could attenuate atherosclerosis and foam cells formation by inhibiting inflammation and upregulating ABCA1 expression., (Copyright © 2017 Elsevier Inc. All rights reserved.)

In atherosclerosis, serum lipoproteins undergo various chemical modifications that impair their normal function. Modification of low density lipoprotein (LDL) such as oxidation, glycation, carbamylation, glucooxidation, etc. makes LDL particles more proatherogenic. Macrophages are responsible for clearance of modified LDL to prevent cytotoxicity, tissue injury, inflammation, and metabolic disturbances. They develop an advanced sensing arsenal composed of various pattern recognition receptors (PRRs) capable of recognizing and binding foreign or altered-self targets for further inactivation and degradation. Modified LDL can be sensed and taken up by macrophages with a battery of scavenger receptors (SRs), of which SR-A1, CD36, and LOX1 play a major role. However, in atherosclerosis, lipid balance is deregulated that induces inability of macrophages to completely recycle modified LDL and leads to lipid deposition and transformation of macrophages to foam cells. SRs also mediate various pathogenic effects of modified LDL on macrophages through activation of the intracellular signaling network. Other PRRs such Toll-like receptors can also interact with modified LDL and mediate their effects independently or in cooperation with SRs., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Background: Vascular disease in diabetes is initiated by monocyte adhesion to vascular endothelium, transmigration and formation of foam cells. Increasing clinical evidence supports a role for the secretory protein, cyclophilin A in diabetic vascular disease. The means by which cyclophilin A contributes to vascular lesion development in diabetes is however largely unknown., Methods: In this study we investigated using THP1 cells and human monocytes whether cyclophilin A under hyperglycemic conditions, functions in the inflammatory cascade as a chemoattractant and increases lipid uptake by formation of foam cells invitro. We developed an invitro model of monocytes cultured in 20 mm glucose (high glucose) equivalent to 360 mg/dL of plasma glucose levels. These monocytes were then differentiated into macrophages using PMA and subsequently transformed to lipid laden foam cells using oxidized low density lipoproteins in the presence and absence of cyclophilin A. This cellular model was used to study monocyte to macrophage differentiation, transmigration and foam cell formation. A similar cellular model using siRNA mediated transient elimination of the cyclophilin A gene as well as chemical inhibitors were used to further confirm the role of cyclophilin A in the differentiation and foam cell formation process., Results: Cyclophilin A effectively increased migration of high glucose treated monocytes to the endothelial cell monolayer (p < 0.0001). In the presence of cyclophilin A, differentiated macrophages, when treated with oxLDL had a 36 percent increase in intracellular lipid accumulation (p = 0.01) when compared to cells treated with oxLDL alone. An increased flux of reactive oxygen species was also observed (p = 0.01). Inflammatory cytokines such as TNF-α, MCP-1 and cyclophilin A were significantly increased. Silencing cyclophilin A in THP-1 cells and human monocytes using siRNA or chemical inhibitor, TMN355 resulted in decrease in lipid uptake by 65-75% even after exposure to oxidized LDL. The expression of scavenger receptors expressed during differentiation process, CD36 and LOX-1 were decreased (p < 0.0001). Levels of extracellular cyclophilin A and other inflammatory cytokines such as TNF-α and MCP-1also significantly reduced., Conclusions: Taken together, we describe here a possible cellular basis by which cyclophilin A may accelerate atherogenesis in diabetes mellitus.

Objective: Monocytes/macrophages (Mϕ) transform into foam cells in the presence of oxidized-LDL (ox-LDL), releasing inflammatory mediators. The antiatherogenic role of a dipeptidyl peptidase-4 inhibitor is mediated, in part, through improving the unbalance of inflammatory (M1)/anti-inflammatory (M2) phenotypes in monocytes. In this study, we examined differential regulation of glucagon-like peptide-1 receptor (GLP-1R) signaling for antiatherogenesis in monocytes/Mϕ from normal-weight control subjects and obese patients., Methods: We evaluated the effects of exendin-4 (Ex-4), a GLP-1R agonist, on ox-LDL-stimulated foam cell formation, M1/M2 cytokine production, and organelle change in primary monocytes from control subjects and obese patients and human monocytic THP-1-derived Mϕ as well., Results: Here we report that Ex-4 suppressed foam cell formation and M1 cytokine expression and, interestingly, induced indicators of autophagy in ox-LDL-stimulated monocytes from control subjects. The suppressing effects on foam cell formation by Ex-4 were reversed by a cAMP inhibitor. In contrast to control subjects, Ex-4 did not induce indicators of autophagy, but did induce foam cell formation and M1 cytokine expression in monocytes from obese patients. GLP-1R expression level was comparable between control subjects and obese patients. The effects of Ex-4 on inducing indicators of autophagy and suppressing foam cell formation were observed in THP-1 Mϕ., Conclusions: These data suggest that GLP-1R signaling induces autophagy, thereby suppressing foam cell formation in non-obese subjects. In obese patients, GLP-1R stimulation increased foam cell formation and IL-6, TNF-α, and IL-1β production. Such altered signaling in monocytes of obese patients may be involved in the development of atherosclerosis., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objective: Macrophages, converted to lipid-loaded foam cells, accumulate in atherosclerotic lesions. Macrophage lipid metabolism is transcriptionally regulated by peroxisome proliferator-activated receptor gamma (PPARγ), and its target gene fatty acid binding protein 4 (FABP4) accelerates the progression of atherosclerosis in mouse models. Since expression of PPARγ and FABP4 is increased upon interleukin-4 (IL-4)-induced macrophage polarization, we aimed to investigate the role of FABP4 in human IL-4-polarized macrophages., Methods and Results: We investigated the impact of FABP4 on PPARγ-dependent gene expression in primary human monocytes differentiated to macrophages in the presence of IL-4. IL-4 increased PPARγ and its target genes lipoprotein lipase (LPL) and FABP4 compared to non-polarized or LPS/interferon γ-stimulated macrophages. LPL expression correlated with increased very low density lipoprotein (VLDL)-induced triglyceride accumulation in IL-4-polarized macrophages, which was sensitive to inhibition of lipolysis or PPARγ antagonism. Inhibition of FABP4 during differentiation using chemical inhibitors BMS309403 and HTS01037 or FABP4 siRNA decreased the expression of FABP4 and LPL, and reduced lipid accumulation in macrophages treated with VLDL. FABP4 or LPL inhibition also reduced the expression of inflammatory mediators chemokine (C-C motif) ligand 2 (CCL2) and IL-1β in response to VLDL in IL-4-polarized macrophages. PPARγ luciferase reporter assays confirmed that FABP4 supports fatty acid-induced PPARγ activation., Conclusion: Our findings suggest that IL-4 induces a lipid-accumulating macrophage phenotype by activating PPARγ and subsequent LPL expression. Inhibition of FABP4 decreases VLDL-induced foam cell formation, indicating that anti-atherosclerotic effects achieved by FABP4 inhibition in mouse models may be feasible in the human system as well., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Atherosclerosis is the primary cause for cardiovascular disease. Here we identified a novel mechanism underlying atherosclerosis, which is provided by ARIA (apoptosis regulator through modulating IAP expression), the transmembrane protein that we recently identified. ARIA is expressed in macrophages present in human atherosclerotic plaque as well as in mouse peritoneal macrophages. When challenged with acetylated LDL, peritoneal macrophages isolated from ARIA-deficient mice showed substantially reduced foam cell formation, whereas the uptake did not differ from that in wild-type macrophages. Mechanistically, loss of ARIA enhanced PI3K/Akt signaling and consequently reduced the expression of acyl coenzyme A:cholesterol acyltransferase-1 (ACAT-1), an enzyme that esterifies cholesterol and promotes its storage, in macrophages. Inhibition of PI3K abolished the reduction in ACAT-1 expression and foam cell formation in ARIA-deficient macrophages. In contrast, overexpression of ARIA reduced Akt activity and enhanced foam cell formation in RAW264.7 macrophages, which was abrogated by treatment with ACAT inhibitor. Of note, genetic deletion of ARIA significantly reduced the atherosclerosis in ApoE-deficient mice. Oil red-O-positive lipid-rich lesion was reduced, which was accompanied by an increase of collagen fiber and decrease of necrotic core lesion in atherosclerotic plaque in ARIA/ApoE double-deficient mice. Analysis of bone marrow chimeric mice revealed that loss of ARIA in bone marrow cells was sufficient to reduce the atherosclerogenesis in ApoE-deficient mice. Together, we identified a unique role of ARIA in the pathogenesis of atherosclerosis at least partly by modulating macrophage foam cell formation. Our results indicate that ARIA could serve as a novel pharmacotherapeutic target for the treatment of atherosclerotic diseases., (© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.)

After a period of relative senescence in the field of vascular smooth muscle cell (VSMC) research with particular regards to atherosclerosis, the last few years has witnessed a resurgence, with extensive research re-assessing potential molecular mechanisms and pathways that modulate VSMC behaviour within the atherosclerotic-prone vessel wall and the atherosclerotic plaque itself. Attention has focussed on the pathological contribution of VSMC in plaque calcification; systemic and local mediators such as inflammatory molecules and lipoproteins; autocrine and paracrine regulators which affect cell-cell and cell to matrix contacts alongside cytoskeletal changes. In this brief focused review, recent insights that have been gained into how a myriad of recently identified factors can influence the pathological behaviour of VSMC and their subsequent contribution to atherosclerotic plaque development and progression has been discussed. An overriding theme is the mechanisms involved in the alterations of VSMC function during atherosclerosis., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.)

Aim: MicroRNAs (miRNAs) play key roles in inflammatory responses of macrophages. However, the function of miRNAs in macrophage-derived foam cell formation is unclear. Here, we investigated the role of miRNAs in macrophage-derived foam cell formation and atherosclerotic development., Methods and Results: Using quantitative reverse transcription-PCR (qRT-PCR), we found that the level of miR-155 expression was increased significantly in both plasma and macrophages from atherosclerosis (ApoE(-/-)) mice. We identified that oxidized low density lipoprotein (oxLDL) induced the expression and release of miR-155 in macrophages, and that miR-155 was required to mediate oxLDL-induced lipid uptake and reactive oxygen species (ROS) production of macrophages. Furthermore, ectopic overexpression and knockdown experiments identified that HMG box-transcription protein1 (HBP1) is a novel target of miR-155. Knockdown of HBP1 enhanced lipid uptake and ROS production in oxLDL-stimulated macrophages, and overexpression of HBP1 repressed these effects. Furthermore, bioinformatics analysis identified three YY1 binding sites in the promoter region of pri-miR-155 and verified YY1 binding directly to its promoter region. Detailed analysis showed that the YY1/HDAC2/4 complex negatively regulated the expression of miR-155 to suppress oxLDL-induced foam cell formation. Importantly, inhibition of miR-155 by a systemically delivered antagomiR-155 decreased clearly lipid-loading in macrophages and reduced atherosclerotic plaques in ApoE(-/-) mice. Moreover, we observed that the level of miR-155 expression was up-regulated in CD14(+) monocytes from patients with coronary heart disease., Conclusion: Our findings reveal a new regulatory pathway of YY1/HDACs/miR-155/HBP1 in macrophage-derived foam cell formation during early atherogenesis and suggest that miR-155 is a potential therapeutic target for atherosclerosis., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.)

Aims: Our previous studies demonstrated that inflammation contributes to atherosclerosis through disruption of the low density lipoprotein receptor (LDLr) pathway. However, this effect is overridden by rapamycin, which is an inhibitor of mammalian target of rapamycin (mTOR). This study investigated the role of the mTOR pathway in atherosclerosis in vivo and in vitro., Methods and Results: To induce inflammation, we used subcutaneous injection of 10% casein in apolipoprotein E knockout (ApoE KO) mice and lipopolysaccharide stimulation in rat vascular smooth muscle cells (VSMCs). Results showed that inflammation increased lipid accumulation in aortas of ApoE KO mice and in VSMCs, which were correlated with increased expressions of LDLr, sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP), and SREBP-2 as well as with enhanced translocation of SCAP/SREBP-2 complex from the endoplasmic reticulum (ER) to the Golgi. Furthermore, inflammation increased both the percentage of cells in the S phase of cell cycle and protein expressions of the phosphorylated forms of retinoblastoma tumour suppressor protein (Rb), mTOR, eukaryotic initiation factor 4E-binding protein 1 (4EBP1), and P70 S6 kinase. After treatment with rapamycin or mTOR siRNA, the activity of the mTOR pathway was blocked. Interestingly, the expression levels of LDLr, SCAP, and SREBP-2 and the translocation of SCAP/SREBP-2 complex from the ER to the Golgi in treated VSMCs were decreased even in the presence of inflammatory stress., Conclusion: Our findings demonstrate for the first time that inflammation disrupts LDLr feedback regulation through the activation of the mTOR pathway. Increased mTORC1 activity was found to up-regulate SREBP-2-mediated cholesterol uptake through Rb phosphorylation.

Conjugated linoleic acid (CLA) has the unique property of inducing regression of pre-established murine atherosclerosis. Understanding the mechanism(s) involved may help identify endogenous pathways that reverse human atherosclerosis. Here, we provide evidence that CLA inhibits foam cell formation via regulation of the nuclear receptor coactivator, peroxisome proliferator-activated receptor (PPAR)-γ coactivator (PGC)-1α, and that macrophage PGC-1α plays a role in atheroprotection in vivo. PGC-1α was identified as a hub gene within a cluster in the aorta of the apoE(-/-) mouse in the CLA-induced regression model. PGC-1α was localized to macrophage/foam cells in the murine aorta where its expression was increased during CLA-induced regression. PGC-1α expression was also detected in macrophages in human atherosclerosis and was inversely linked to disease progression in patients with the disease. Deletion of PGC-1α in bone marrow derived macrophages promoted, whilst over expression of the gene inhibited foam cell formation. Importantly, macrophage specific deletion of PGC-1α accelerated atherosclerosis in the LDLR(-/-) mouse in vivo. These novel data support a functional role for PGC-1α in atheroprotection., (© 2013 The Authors. Published by John Wiley and Sons, Ltd on behalf of EMBO.)

BACKGROUND: Ferroptosis is an iron-dependent regulatory form of cell death characterized by iron-dependent lipid peroxidation. Long-chain acyl-coenzyme A synthase 4 (ACSL4) is involved in the formation of lipid peroxidation substrates, thereby resulting in ferroptosis. Recent studies have shown that ACSL4- mediated ferroptosis plays a key role in atherosclerotic cardiovascular disease. OBJECTIVE: To summarize the structural function and regulatory mechanism of ACSL4 and its potential molecular mechanism mediating ferroptosis, and to elaborate the application of ACSL4 driving ferroptosis in atherosclerosis, ischemic stroke and myocardial infarction, in order to provide a new therapeutic strategy for the treatment of atherosclerotic cardiovascular diseases. METHODS: Relevant literature was searched in PubMed database from database inception to August 2023 using the keywords of “atherosclerosis, ferroptosis, long-chain acyl-coenzyme A synthase 4, ACSL4, glutathione peroxidase 4, ischemic stroke, myocardial infarction, endothelial cell, smooth muscle cells, foam cell.” Finally, 76 documents were included for review and analysis. RESULTS AND CONCLUSION: ACSL4 participates in the formation of coenzyme derivatives of polyunsaturated fatty acids and inserts them into phospholipids to provide substrates for lipid peroxidation, the core mechanism of iron death. Among the regulatory factors of ACSL4 expression, integrin α6β4, intracellular vesicular transport factor p115, and zinc lipoprotein A20 negatively regulate its expression. Meanwhile, multiple miRs down-regulate its expression by binding to 3’-UTR. On the contrary, up-regulation of ACSL4 is mostly regulated by transcription factors. ACSL4-dependent production of phospholipids containing polyunsaturated fatty acids is an essential prerequisite for lipid peroxidation and ferroptosis. Moreover, ACSL4 and glutathione peroxidase 4 are mutually dependent as positive and negative regulators of ferroptosis, and their specific mechanisms remain to be further studied. ACSL4-mediated ferroptosis is involved in the pathological mechanism of atherosclerosis, ischemic stroke, and myocardial infarction. Endothelial cell injury in atherosclerosis is closely related to ACSL4-mediated ferroptosis, but there are no reports on the involvement of ACSL4 in foam cell formation, smooth muscle cell phenotype transformation, and calcification. ACSL4 has become a research hotspot as a biomarker and potential target of ferroptosis. Targeting ACSL4 to inhibit ferroptosis may become a new direction for the treatment of atherosclerotic cardiovascular diseases. However, there are few studies on drugs inhibiting ACSL4, and further studies are needed in the future. [ABSTRACT FROM AUTHOR]

Macrophage-derived lipid-laden foam cells from the subendothelium play a crucial role in the initiation and progression of atherosclerosis. However, the molecule mechanism that regulates the formation of foam cells is not completely understood. Here, we found that SLAMF7 was upregulated in mice bone marrow–derived macrophages and RAW264.7 cells stimulated with oxidized low-density lipoprotein (ox-LDL). SLAMF7 promoted ox-LDL-mediated macrophage lipid accumulation and M1-type polarization. SLAMF7 deficiency reduced serum lipid levels and improved the lesions area of carotid plaque and aortic arch in high-fat diet-fed ApoE−/− mice. In response to ox-LDL, SLAMF7 downregulated NR4A1 and upregulated RUNX3 through transcriptome sequencing analysis. Overexpression NR4A1 reversed SLAMF7-induced lipid uptake and M1 polarization via inhibiting RUNX3 expression. Furthermore, RUNX3 enhanced foam cell formation and M1-type polarization. Taken together, the study suggested that SLAMF7 play contributing roles in the pro-atherogenic effects by regulating NR4A1-RUNX3. [ABSTRACT FROM AUTHOR]

Objective To explore the inhibitory effect of Danyu formula on foam cell formation in rat aortic endothelial cells (RAECs) induced by oxidized low-density lipoprotein (Ox-LDL) and its possible mechanism. Methods RAECs were randomly divided into the control group, model group, low-dose Danyu formula group, medium-dose Danyu formula group, and high-dose Danyu formula group, and atorvastatin group. Except for the control group, RAECs in the rest of the five groups were treated with 200 µg/mL Ox-LDL for 72 h, and the low-, medium-, and high-dose Danyu formula groups and the atorvastatin group were treated with 50, 100, and 200 µg/L Danyu formula solution and 300 µg/L atorvastatin, respectively. After 24, 48, and 72 h of treatment, the cell proliferation ability was detected by CCK-8. The foam formation was observed by oil red O staining in the cells treated for 72 h in each group. The protein levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), malondialdehyde (MDA), and superoxide dismutase (SOD) in the cell supernatant were measured by ELISA. The reactive oxygen species (ROS) content was determined by the 2-hydroxyethylfluorescein oxidation fluorescence reaction. The relative mRNA expression levels of protein tyrosine kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) were detected by real-time fluorescence quantitative PCR. The relative protein expression levels of JAK2, p-JAK2, STAT3, and p-STAT3 were determined by Western blotting, and the ratios of p-JAK2/JAK2 and p-STAT3/STAT3 were calculated. Results Compared with the control group, the OD values of the model group decreased at the same time points (all P<0. 05). Compared with the model group at the same time points, the OD values of the high-dose Danyu formula group and the atorvastatin group increased, and the OD values of the mediumdose Danyu formula group increased at 48 and 72h (all P<0. 05). The control group cells did not exhibit foam formation, while the cells in the model group showed obvious foam formation. Compared with the model group, the foam formation in the atorvastatin group and the high-, medium-, and low-dose Danyu formula groups improved, with the high-dose Danyu formula group and the atorvastatin group showing the most significant improvement, almost approaching the control group. Compared with the control group, the levels of TNF-α, IL-6, ROS, JAK2 mRNA expression, STAT3 mRNA expression, p-JAK2/JAK2, p-STAT3/STAT3, and MDA in the cell supernatant of the model group increased, while the expression of SOD in the cell supernatant decreased (all P<0. 05). Compared with the model group, the levels of TNF-α, IL-6, ROS, JAK2 mRNA expression, STAT3 mRNA expression, p-JAK2/JAK2, p-STAT3/STAT3, and MDA in the cell supernatant of the atorvastatin group and the high-, medium-, and low-dose Danyu formula groups decreased, while the expression of SOD in the cell supernatant increased, with the most significant changes in the atorvastatin group and the high-dose Danyu formula group (all P<0. 05). There were no significant differences in the relative protein expression levels of JAK2 or STAT3 among these groups (all P>0. 05). Conclusion The high-dose, medium-dose, and low-dose Danyu formula can inhibit foam formation in Ox-LDL-induced RAECs, with the significant effect in the high-dose Danyu formula, and its mechanism may be related to the inhibition of inflammatory reaction, oxidative stress response, and JAK2/STAT3 signaling pathway. [ABSTRACT FROM AUTHOR]