Neoagarotetraose Alleviates Atherosclerosis via Modulating Cholesterol and Bile Acid Metabolism in ApoE-/- Mice.

Atherosclerosis is closely associated with metabolic disorders such as cholesterol accumulation, bile acid metabolism, and gut dysbiosis. Neoagarotetraose supplementation has been shown to inhibit obesity and alleviate type 2 diabetes, but its effects on modulating the development of atherosclerosis remain unexplored. Therefore, the present study was conducted to investigate the protective effects and potential mechanisms of neoagarotetraose on high-fat, high-cholesterol diet (HFHCD)-induced atherosclerosis in ApoE-/- mice. The results showed that neoagarotetraose supplementation decreased the atherosclerotic lesion area by 50.1% and the aortic arch lesion size by 80.4% compared to the HFHCD group. Furthermore, neoagarotetraose supplementation led to a significant reduction in hepatic lipid content, particularly non-high-density lipoprotein cholesterol. It also resulted in a substantial increase in total bile acid content in both urine and fecal samples by 3.0-fold and 38.7%, respectively. Moreover, neoagarotetraose supplementation effectively downregulated the intestinal farnesoid X receptor by 35.8% and modulated the expressions of its associated genes in both the liver and intestine. In addition, correlation analysis revealed strong associations between gut microbiota composition and fecal bile acid levels. These findings highlight the role of gut microbiota in neoagarotetraose-mitigating atherosclerosis in HFHCD-fed ApoE-/- mice. This study indicates the potential of neoagarotetraose as a functional dietary supplement for the prevention of atherosclerosis.

The Anti-Atherosclerotic Effects of Buyang Huanwu Decoction through M1 and M2 Macrophage Polarization in an ApoE Knockout Mouse Model.

ABSTRACT: Arteriosclerosis (AS) is a chronic inflammatory disease and Buyang Huanwu decoction (BHD) has been identified as an anti-atherosclerosis effect, and the study is aimed to investigate the underlying mechanism. The E4 allele of Apolipoprotein E (ApoE) is associated with both metabolic dysfunction and an enhanced pro-inflammatory response, ApoE-knockout (ApoE-/-) mice were fed with a high-fat diet to establish an arteriosclerosis model and treated with BHD or atorvastatin (as a positive control). The atherosclerotic plaque in each mouse was evaluated using Oil red O Staining. Elisa kits were used to evaluate blood lipid, interleukin-6 (IL-6), IL-1 beta (IL-1ß), tumor necrosis factor alpha (TNF-α), IL-4, IL-10, and tumor growth factor beta (TGF-ß) contents, while Western blot was applicated to measure inducible nitric oxide synthase (iNOS), arginase I (Arg-1) expression. Meanwhile, pyruvate kinase M2 (PKM2), hypoxia-inducible factor-1 alpha (HIF-1α) and its target genes glucose transporter type 1 (GLUT1), lactate dehydrogenase A (LDHA), and 3-phosphoinositide-dependent kinase 1 (PDK1), as well as IL-6, IL-1ß, TNF-α, IL-4, IL-10, and TGF-ß were evaluated by the quantitative reverse transcription-polymerase chain reaction. BHD treatment significantly reduced body weight and arteriosclerosis plaque area and blood lipid levels including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). Meanwhile, BHD demonstrated a significant suppression of M1 polarization, by decreased secretion of iNOS and pro-inflammatory factors (IL-6, IL-1ß, and TNF-α) in ApoE-/- mice. The present study also revealed that BHD promotes the activation of M2 polarization, characterized by the expression of Arg-1 and anti-inflammatory factors (IL-4 and IL-10). In addition, PKM2/HIF-1α signaling was improved by M1/M2 macrophages polarization induced by BHD. The downstream target genes (GLUT1, LDHA, and PDK1) expression was significantly increased in high fat feeding ApoE-/- mice, and those of which were recused by BHD and Atorvastatin. These results suggested that M1/M2 macrophages polarization produce the inflammatory response against AS progress after BHD exposure.

Buyang Huanwu Decoction Alleviates Atherosclerosis by Regulating gut Microbiome and Metabolites in Apolipoprotein E-deficient Mice fed with High-fat Diet.

ABSTRACT: The traditional Chinese herbal prescription Buyang Huanwu decoction (BHD), effectively treats atherosclerosis. However, the mechanism of BHD in atherosclerosis remains unclear. We aimed to determine whether BHD could alleviate atherosclerosis by altering the microbiome-associated metabolic changes in atherosclerotic mice. An atherosclerotic model was established in apolipoprotein E-deficient mice fed high-fat diet, and BHD was administered through gavage for 12 weeks at 8.4 g/kg/d and 16.8 g/kg/d. The atherosclerotic plaque size, composition, serum lipid profile, and inflammatory cytokines, were assessed. Mechanistically, metabolomic and microbiota profiles were analyzed by liquid chromatography-mass spectrometry and 16S rRNA gene sequencing, respectively. Furthermore, intestinal microbiota and atherosclerosis-related metabolic parameters were correlated using Spearman analysis. Atherosclerotic mice treated with BHD exhibited reduced plaque area, aortic lumen occlusion, and lipid accumulation in the aortic root. Nine perturbed serum metabolites were significantly restored along with the relative abundance of microbiota at the family and genus levels but not at the phylum level. Gut microbiome improvement was strongly negatively correlated with improved metabolite levels. BHD treatment effectively slows the progression of atherosclerosis by regulating altered intestinal microbiota and perturbed metabolites.

Corilagin alleviates atherosclerosis by inhibiting NLRP3 inflammasome activation via the Olfr2 signaling pathway in vitro and in vivo.

Introduction: Atherosclerosis, a leading cause of global cardiovascular mortality, is characterized by chronic inflammation. Central to this process is the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome, which significantly influences atherosclerotic progression. Recent research has identified that the olfactory receptor 2 (Olfr2) in vascular macrophages is instrumental in driving atherosclerosis through NLRP3- dependent IL-1 production. Methods: To investigate the effects of Corilagin, noted for its anti-inflammatory attributes, on atherosclerotic development and the Olfr2 signaling pathway, our study employed an atherosclerosis model in ApoE-/- mice, fed a high-fat, high-cholesterol diet, alongside cellular models in Ana-1 cells and mouse bone marrow-derived macrophages, stimulated with lipopolysaccharides and oxidized low-density lipoprotein. Results: The vivo and vitro experiments indicated that Corilagin could effectively reduce serum lipid levels, alleviate aortic pathological changes, and decrease intimal lipid deposition. Additionally, as results showed, Corilagin was able to cut down expressions of molecules associated with the Olfr2 signaling pathway. Discussion: Our findings indicated that Corilagin effectively inhibited NLRP3 inflammasome activation, consequently diminishing inflammation, macrophage polarization, and pyroptosis in the mouse aorta and cellular models via the Olfr2 pathway. This suggests a novel therapeutic mechanism of Corilagin in the treatment of atherosclerosis.

CCL18 aggravates atherosclerosis by inducing CCR6-dependent T-cell influx and polarization.

Introduction: The CC chemokine ligand 18 (CCL18) is a chemokine highly expressed in chronic inflammation in humans. Recent observations of elevated CCL18 plasma levels in patients with acute cardiovascular syndromes prompted an investigation into the role of CCL18 in the pathogenesis of human and mouse atherosclerosis. Methods and results: CCL18 was profoundly upregulated in ruptured human atherosclerotic plaque, particularly within macrophages. Repeated administration of CCL18 in Western-type diet-fed ApoE -/- mice or PCSK9mut-overexpressing wild type (WT) mice led to increased plaque burden, enriched in CD3+ T cells. In subsequent experimental and molecular modeling studies, we identified CCR6 as a functional receptor mediating CCL18 chemotaxis, intracellular Ca2+ flux, and downstream signaling in human Jurkat and mouse T cells. CCL18 failed to induce these effects in vitro in murine spleen T cells with CCR6 deficiency. The ability of CCR6 to act as CCL18 receptor was confirmed in vivo in an inflammation model, where subcutaneous CCL18 injection induced profound focal skin inflammation in WT but not in CCR6-/- mice. This inflammation featured edema and marked infiltration of various leukocyte subsets, including T cells with a Th17 signature, supporting CCR6's role as a Th17 chemotactic receptor. Notably, focal overexpression of CCL18 in plaques was associated with an increased presence of CCR6+ (T) cells. Discussion: Our studies are the first to identify the CCL18/CCR6 axis as a regulator of immune responses in advanced murine and human atherosclerosis.

IL-1ß Inhibition Partially Negates the Beneficial Effects of Diet-Induced Atherosclerosis Regression in Mice.

BACKGROUND: Thromboembolic events secondary to rupture or erosion of advanced atherosclerotic lesions is the global leading cause of death. The most common and effective means to reduce these major adverse cardiovascular events, including myocardial infarction and stroke, is aggressive lipid lowering via a combination of drugs and dietary modifications. However, we know little regarding the effects of reducing dietary lipids on the composition and stability of advanced atherosclerotic lesions, the mechanisms that regulate these processes, and what therapeutic approaches might augment the benefits of lipid lowering. METHODS: Smooth muscle cell lineage-tracing Apoe-/- mice were fed a high-cholesterol Western diet for 18 weeks and then a zero-cholesterol standard laboratory diet for 12 weeks before treating them with an IL (interleukin)-1ß or control antibody for 8 weeks. We assessed lesion size and remodeling indices, as well as the cellular composition of aortic and brachiocephalic artery lesions, indices of plaque stability, overall plaque burden, and phenotypic transitions of smooth muscle cell and other lesion cells by smooth muscle cell lineage tracing combined with single-cell RNA sequencing, cytometry by time-of-flight, and immunostaining plus high-resolution confocal microscopic z-stack analysis. RESULTS: Lipid lowering by switching Apoe-/- mice from a Western diet to a standard laboratory diet reduced LDL cholesterol levels by 70% and resulted in multiple beneficial effects including reduced overall aortic plaque burden, as well as reduced intraplaque hemorrhage and necrotic core area. However, contrary to expectations, IL-1ß antibody treatment after diet-induced reductions in lipids resulted in multiple detrimental changes including increased plaque burden and brachiocephalic artery lesion size, as well as increasedintraplaque hemorrhage, necrotic core area, and senescence as compared with IgG control antibody-treated mice. Furthermore, IL-1ß antibody treatment upregulated neutrophil degranulation pathways but downregulated smooth muscle cell extracellular matrix pathways likely important for the protective fibrous cap. CONCLUSIONS: Taken together, IL-1ß appears to be required for the maintenance of standard laboratory diet-induced reductions in plaque burden and increases in multiple indices of plaque stability.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Naoxintong capsule remodels gut microbiota and ameliorates early-stage atherosclerosis in apolipoprotein E-deficient mice.

BACKGROUND: Naoxintong capsule (NXT) is a compound traditional Chinese medicine prescription with demonstrated effect for the treatment of cardiovascular and cerebrovascular diseases including atherosclerosis (AS). However, the pharmacological mechanisms of NXT in ameliorating early-stage AS are still unclear, especially regarding the role of gut microbiota. PURPOSE: This study is aiming to evaluate the therapeutic effect of NXT against early-stage AS, and further illustrate the potential correlations among AS, gut microbiota, and NXT. METHODS: Thirty-two male ApoE knockout mice (C57BL/6 background) were fed with a high cholesterol diet (HCD) for 4 weeks to establish an early-stage AS model. NXT in two different dosages and simvastatin (Simv) were than administrated for another 8 weeks. Lipid metabolism indicators and inflammation levels were measured with corresponding assay kits. Changes in blood vessels, liver lesions, and intestinal barrier proteins were evaluated with different staining methods. Furthermore, the gut microbiota structure was analyzed using 16S rRNA sequencing technology, while GC-MS was utilized to determine the fecal contents of short-chain fatty acids (SCFAs). RESULTS: Administration of NXT significantly ameliorated obesity, hyperlipidemia, systemic inflammation, vasculopathy, liver injury, and intestinal barrier disorder in AS mice. Administration of NXT also significantly regulated the gut microbiota disturbance and increased the total contents of fecal SCFAs in AS mice. Furthermore, acetic acid content and the relative abundance of Faecalibacterium in feces were proposed as potential therapeutic biomarkers of NXT for AS treatment as indicated via the correlation analysis. CONCLUSION: This study demonstrated that NXT could effectively treat early-stage AS induced by HCD in mice. NXT regulated the gut microbiota and metabolites, maintained intestinal homeostasis, and improved the systemic inflammatory response. These findings may provide robust experimental support for the clinical use of NXT for AS treatment.

SPAG5 deficiency activates autophagy to reduce atherosclerotic plaque formation in ApoE-/- mice.

BACKGROUND: Autophagy, as a regulator of cell survival, plays an important role in atherosclerosis (AS). Sperm associated antigen 5 (SPAG5) is closely associated with the classical autophagy pathway, PI3K/Akt/mTOR signaling pathway. This work attempted to investigate whether SPAG5 can affect AS development by regulating autophagy. METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with oxidized-low density lipoprotein (ox-LDL) to induce cell damage. ApoE-/- mice were fed a Western diet to establish an AS mouse model. Haematoxylin and eosin (H&E) staining and Oil Red O staining evaluated the pathological changes and in lipid deposition in aortic tissues. CCK-8 and flow cytometry detected cell proliferation and apoptosis. Immunohistochemistry, Enzyme linked immunosorbent assay, qRT-PCR and western blotting assessed the levels of mRNA and proteins. RESULTS: Ox-LDL treatment elevated SPAG5 expression and the expression of autophagy-related proteins, LC3-I, LC3-II, Beclin-1, and p62, in HUVECs. GFP-LC3 dots were increased in ox-LDL-treated HUVECs and LPS-treated HUVECs. SPAG5 knockdown reversed both ox-LDL and LPS treatment-mediated inhibition of cell proliferation and promotion of apoptosis in HUVECs. SPAG5 silencing further elevated autophagy and repressed the expression of PI3K, p-Akt/Akt, and p-mTOR/mTOR in ox-LDL-treated HUVECs. 3-MA (autophagy inhibitor) treatment reversed SPAG5 silencing-mediated increase of cell proliferation and decrease of apoptosis in ox-LDL-treated HUVECs. In vivo, SPAG5 knockdown reduced atherosclerotic plaques in AS mice through activating autophagy and inhibiting PI3K/Akt/mTOR signaling pathway. CONCLUSION: This work demonstrated that SPAG5 knockdown alleviated AS development through activating autophagy. Thus, SPAG5 may be a potential target for AS therapy.

Quinic acid regulated TMA/TMAO-related lipid metabolism and vascular endothelial function through gut microbiota to inhibit atherosclerotic.

BACKGROUND: Quinic acid (QA) and its derivatives have good lipid-lowering and hepatoprotective functions, but their role in atherosclerosis remains unknown. This study attempted to investigate the mechanism of QA on atherogenesis in Apoe-/- mice induced by HFD. METHODS: HE staining and oil red O staining were used to observe the pathology. The PCSK9, Mac-3 and SM22a expressions were detected by IHC. Cholesterol, HMGB1, TIMP-1 and CXCL13 levels were measured by biochemical and ELISA. Lipid metabolism and the HMGB1-SREBP2-SR-BI pathway were detected by PCR and WB. 16 S and metabolomics were used to detect gut microbiota and serum metabolites. RESULTS: QA or low-frequency ABX inhibited weight gain and aortic tissue atherogenesis in HFD-induced Apoe-/- mice. QA inhibited the increase of cholesterol, TMA, TMAO, CXCL13, TIMP-1 and HMGB1 levels in peripheral blood of Apoe-/- mice induced by HFD. Meanwhile, QA or low-frequency ABX treatment inhibited the expression of CAV-1, ABCA1, Mac-3 and SM22α, and promoted the expression of SREBP-1 and LXR in the vascular tissues of HFD-induced Apoe-/- mice. QA reduced Streptococcus_danieliae abundance, and promoted Lactobacillus_intestinalis and Ileibacterium_valens abundance in HFD-induced Apoe-/- mice. QA altered serum galactose metabolism, promoted SREBP-2 and LDLR, inhibited IDOL, FMO3 and PCSK9 expression in liver of HFD-induced Apoe-/- mice. The combined treatment of QA and low-frequency ABX regulated microbe-related Glycoursodeoxycholic acid and GLYCOCHENODEOXYCHOLATE metabolism in HFD-induced Apoe-/- mice. QA inhibited TMAO or LDL-induced HCAECs damage and HMGB1/SREBP2 axis dysfunction, which was reversed by HMGB1 overexpression. CONCLUSIONS: QA regulated the gut-liver lipid metabolism and chronic vascular inflammation of TMA/TMAO through gut microbiota to inhibit the atherogenesis in Apoe-/- mice, and the mechanism may be related to the HMGB1/SREBP2 pathway.

DFMG decreases angiogenesis to uphold plaque stability by inhibiting the TLR4/VEGF pathway in mice.

The aim of this study was to elucidate the specific mechanism through which 7-difluoromethoxy-5,4'-dimethoxygenistein (DFMG) inhibits angiogenesis in atherosclerosis (AS) plaques, given its previously observed but poorly understood inhibitory effects. In vitro, a model using Human Umbilical Vein Endothelial (HUVEC-12) cells simulated the initial lesion in the atherosclerotic pathological process, specifically oxidative stress injury, by exposing cells to 30 µmol/L LPC. Additionally, an AS mouse model was developed in ApoE knockout mice through a 16-week period of high-fat feeding. DFMG demonstrated a reduction in tubule quantities in the tube formation assay and neovascularization induced by oxidative stress-damaged endothelial cells in the chicken embryo chorioallantoic membrane assay. Furthermore, DFMG decreased lipid levels in the blood of ApoE knockout mice with AS, along with a decrease in atherosclerotic plaques and neovascularizations in the aortic arch and descending aorta of AS animal models. DFMG treatment upregulated microRNA140 (miR-140) expression and suppressed VEGF secretion in HUVEC-12 cells. These effects were counteracted by Toll-like receptor 4 (TLR4) overexpression in HUVEC-12 cells subjected to oxidative injury or in a mouse model of AS. Dual-luciferase reporter assays demonstrated that miR-140 directly targeted TLR4. Immunohistochemical assay findings indicated a significant inverse relationship between miR-140 expression and TLR4 expression in ApoE knockout mice subjected to a high-fat diet. The study observed a close association between DFMG inhibitory effects on angiogenesis and plaque stability in AS, and the inhibition of the TLR4/NF-κB/VEGF signaling pathway, negatively regulated by miR-140.

Jiawei Dachaihu decoction protects against mitochondrial dysfunction in atherosclerosis (AS) mice with chronic unpredictable mild stress (CUMS) via SIRT1/PGC-1α/TFAM/LON signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: JiaWei DaChaiHu is composed of Bupleurum chinense, Scutellaria baicalensis, Pinellia ternata, Paeonia lactiflora, Zingiber officinaleRoscoe, Poncirus tuifoliata, Rheum palmatum L., Curcumae Radix, Herba Lysimachiae, Ziziphus. JiaWei DaChaiHu is one of the most common traditional Chinese medicines for the treatment of depression. AIM OF THE STUDY: The chronic unpredictable mild stress (CUMS) has been shown to promote atherosclerosis (AS). Dachaihu has been widely used in traditional Chinese medicine and has been known to exert distinct pharmacological effects. This investigation aims to examine the therapeutic effect of Jiawei Dachaihu extract on AS animal models with CUMS. METHODS: AS-CUMS mice model was established by Apoe-/- mice. Mice were treated with Jiawei Dachaihu. Serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C) levels were measured using ELISA kits. Aortic tissue pathologic changes detected by oil red O staining. Mice behavioral changes detected by sucrose preference test and sucrose preference test. The relative mRNA expression levels of CRH, ND1, and TFAM were determined by qRT-PCR. 5-HT1A, BDNF, LON, TFAM, PGC-1α, and SIRT1 protein expression determined by western blotting. ATP content detected by ATP kits. RESULTS: The treatment with Jiawei Dachaihu extract alleviated the veins plaque and reduced stress signs in vitro and in vivo. It increased the ATP and HDL-C levels while decreased the TC, TG, LDL-C levels. Jiawei Dachaihu extract treatment upregulated Lon, SIRT1, TFAM, PGC-1α, BDNF, and 5-HT1A protein expression and regained mitochondrial function. CONCLUSION: Jiawei Dachaihu extract could alleviate AS and reduce CUMS by upregulating the SIRT1/PGC-1α signaling and promoted its crosstalk with Lon protein to maintain mitochondrial stability.

Dan-shen Yin promotes bile acid metabolism and excretion to prevent atherosclerosis via activating FXR/BSEP signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Dan-shen Yin (DSY), a traditional prescription, has been demonstrated to be effective in decreasing hyperlipidemia and preventing atherosclerosis (AS), but its mechanism remains unknown. We hypothesized that DSY activates farnesoid X receptor (FXR) to promote bile acid metabolism and excretion, thereby alleviating AS. AIM OF THE STUDY: This study was designed to explore whether DSY reduces liver lipid accumulation and prevents AS by activating FXR and increasing cholesterol metabolism and bile acid excretion. MATERIALS AND METHODS: The comprehensive chemical characterization of DSY was analyzed by UHPLC-MS/MS. The AS models of ApoE-/- mice and SD rats was established by high-fat diet and high-fat diet combined with intraperitoneal injection of vitamin D3, respectively. The aortic plaque and pathological changes were used to evaluate AS. Lipid levels, H&E staining and oil red O staining were used to evaluate liver lipid accumulation. The cholesterol metabolism and bile acid excretion were evaluated by enzyme-linked immunosorbent assay, UPLC-QQQ/MS. In vitro, the lipid and FXR/bile salt export pump (BSEP) levels were evaluated by oil red O staining, real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting. RESULTS: A total of 36 ingredients in DSY were identified by UPLC-MS/MS analysis. In vivo, high-dose DSY significantly inhibited aortic intimal thickening, improved arrangement disorder, tortuosity, and rupture of elastic fibers, decreased lipid levels, and reduced the number of fat vacuoles and lipid droplets in liver tissue in SD rats and ApoE-/- mice. Further studies found that high-dose DSY significantly reduced liver lipid and total bile acids levels, increased liver ursodeoxycholic acid (UDCA) and other non-conjugated bile acids levels, increased fecal total cholesterol (TC) levels, and augmented FXR, BSEP, cholesterol 7-alpha hydroxylase (CYP7A1), ATP binding cassette subfamily G5/G8 (ABCG5/8) expression levels, while decreasing ASBT expression levels. In vitro studies showed that DSY significantly reduced TC and TG levels, as well as lipid droplets, while also increasing the expression of ABCG5/8, FXR, and BSEP in both HepG2 and Nr1h4 knockdown HepG2 cells. CONCLUSION: This study demonstrated that DSY promotes bile acid metabolism and excretion to prevent AS by activating FXR. For the prevent of AS and drug discovery provided experimental basis.

Morus alba L. (Sangzhi) alkaloids mitigate atherosclerosis by regulating M1/M2 macrophage polarization.

BACKGROUND: Atherosclerosis (AS) is an important cause of cardiovascular disease, posing a substantial health risk. Recognized as a chronic inflammatory disorder, AS hinges on the pivotal involvement of macrophages in arterial inflammation, participating in its formation and progression. Sangzhi alkaloid (SZ-A) is a novel natural alkaloid extracted from the mulberry branches, has extensive pharmacological effects and stable pharmacokinetic characteristics. However, the effects and mechanisms of SZ-A on AS remain unclear. PURPOSE: To explore the effect and underlying mechanisms of SZ-A on inflammation mediated by macrophages and its role in AS development. METHODS: Atherosclerosis was induced in vivo in apolipoprotein E-deficient mice through a high-fat and high-choline diet. We utilized macrophages and vascular endothelial cells to investigate the effects of SZ-A on macrophage polarization and its anti-inflammatory properties on endothelial cells in vitro. The transcriptomic analyses were used to investigate the major molecule that mediates cell-cell interactions and the antiatherogenic mechanisms of SZ-A based on AS, subsequently validated in vivo and in vitro. RESULTS: SZ-A demonstrated a significant inhibition in vascular inflammation and alleviation of AS severity by mitigating macrophage infiltration and modulating M1/M2 macrophage polarization in vitro and in vivo. Moreover, SZ-A effectively reduced the release of the proinflammatory mediator C-X-C motif chemokine ligand (CXCL)-10, predominantly secreted by M1 macrophages. This reduction in CXCL-10 contributed to improved endothelial cell function, reduced recruitment of additional macrophages, and inhibited the inflammatory amplification effect. This ultimately led to the suppression of atherogenesis. CONCLUSION: SZ-A exhibited potent anti-inflammatory effects by inhibiting macrophage-mediated inflammation, providing a new therapeutic avenue against AS. This is the first study demonstrating the efficacy of SZ-A in alleviating AS severity and offers novel insights into its anti-inflammatory mechanism.

Fisetin Suppresses Atherosclerosis by Inhibiting Ferroptosis-Related Oxidative Stress in Apolipoprotein E Knockout Mice.

INTRODUCTION: Fisetin has been demonstrated to inhibit the occurrence of atherosclerosis; however, the mechanism of fisetin suppressing atherosclerosis remains elusive. METHODS: The function of fisetin in the inhibition of atherosclerosis was evaluated by hematoxylin and eosin and Oil Red O staining in ApoE-/- mice. Molecular biomarkers of atherosclerosis progression were detected by Western blot and qPCR. Moreover, the inhibition of atherosclerosis on oxidative stress and ferroptosis was evaluated by immunofluorescence staining, qPCR, and Western blot assays. RESULTS: The obtained results showed that serum lipid was attenuated and consequentially the formation of atherosclerosis was also suppressed by fisetin in ApoE-/- mice. Exploration of the mechanism revealed that molecular biomarkers of atherosclerosis were decreased under fisetin treatment. The level of reactive oxygen species and malondialdehyde declined, while the activity of superoxide dismutases and glutathione peroxidase was increased under the fisetin treatment. Additionally, the suppressor of ferroptosis, glutathione peroxidase 4 proteins, was elevated. The ferritin was decreased in the aortic tissues treated with fisetin. CONCLUSIONS: In summary, fisetin attenuated the formation of atherosclerosis through the inhibition of oxidative stress and ferroptosis in the aortic tissues of ApoE-/- mice.

Immunoproteasomal Inhibition With ONX-0914 Attenuates Atherosclerosis and Reduces White Adipose Tissue Mass and Metabolic Syndrome in Mice.

BACKGROUND: Atherosclerosis is the major underlying pathology of cardiovascular disease and is driven by dyslipidemia and inflammation. Inhibition of the immunoproteasome, a proteasome variant that is predominantly expressed by immune cells and plays an important role in antigen presentation, has been shown to have immunosuppressive effects. METHODS: We assessed the effect of ONX-0914, an inhibitor of the immunoproteasomal catalytic subunits LMP7 (proteasome subunit ß5i/large multifunctional peptidase 7) and LMP2 (proteasome subunit ß1i/large multifunctional peptidase 2), on atherosclerosis and metabolism in LDLr-/- and APOE*3-Leiden.CETP mice. RESULTS: ONX-0914 treatment significantly reduced atherosclerosis, reduced dendritic cell and macrophage levels and their activation, as well as the levels of antigen-experienced T cells during early plaque formation, and Th1 cells in advanced atherosclerosis in young and aged mice in various immune compartments. Additionally, ONX-0914 treatment led to a strong reduction in white adipose tissue mass and adipocyte progenitors, which coincided with neutrophil and macrophage accumulation in white adipose tissue. ONX-0914 reduced intestinal triglyceride uptake and gastric emptying, likely contributing to the reduction in white adipose tissue mass, as ONX-0914 did not increase energy expenditure or reduce total food intake. Concomitant with the reduction in white adipose tissue mass upon ONX-0914 treatment, we observed improvements in markers of metabolic syndrome, including lowered plasma triglyceride levels, insulin levels, and fasting blood glucose. CONCLUSIONS: We propose that immunoproteasomal inhibition reduces 3 major causes underlying cardiovascular disease, dyslipidemia, metabolic syndrome, and inflammation and is a new target in drug development for atherosclerosis treatment.

IL-33 Reduces Saturated Fatty Acid Accumulation in Mouse Atherosclerotic Foci.

The cellular and molecular mechanisms of atherosclerosis are still unclear. Type 2 innate lymphocytes (ILC2) exhibit anti-inflammatory properties and protect against atherosclerosis. This study aimed to elucidate the pathogenesis of atherosclerosis development using atherosclerosis model mice (ApoE KO mice) and mice deficient in IL-33 receptor ST2 (ApoEST2 DKO mice). Sixteen-week-old male ApoE KO and ApoEST2 DKO mice were subjected to an 8-week regimen of a high-fat, high-sucrose diet. Atherosclerotic foci were assessed histologically at the aortic valve ring. Chronic inflammation was assessed using flow cytometry and real-time polymerase chain reaction. In addition, saturated fatty acids (palmitic acid) and IL-33 were administered to human aortic endothelial cells (HAECs) to assess fatty acid metabolism. ApoEST2 DKO mice with attenuated ILC2 had significantly worse atherosclerosis than ApoE KO mice. The levels of saturated fatty acids, including palmitic acid, were significantly elevated in the arteries and serum of ApoEST2 DKO mice. Furthermore, on treating HAECs with saturated fatty acids with or without IL-33, the Oil Red O staining area significantly decreased in the IL-33-treated group compared to that in the non-treated group. IL-33 potentially prevented the accumulation of saturated fatty acids within atherosclerotic foci.

Heparanase promotes the onset and progression of atherosclerosis in apolipoprotein E gene knockout mice.

BACKGROUND AND AIMS: Atherosclerosis is the primary underlying cause of myocardial infarction and stroke, which are the major causes of death globally. Heparanase (Hpse) is a pro-inflammatory extracellular matrix degrading enzyme that has been implicated in atherogenesis. However, to date the precise roles of Hpse in atherosclerosis and its mechanisms of action are not well defined. This study aims to provide new insights into the contribution of Hpse in different stages of atherosclerosis in vivo. METHODS: We generated Hpse gene-deficient mice on the atherosclerosis-prone apolipoprotein E gene knockout (ApoE-/-) background to investigate the impact of Hpse gene deficiency on the initiation and progression of atherosclerosis after 6 and 14 weeks high-fat diet feeding, respectively. Atherosclerotic lesion development, blood serum profiles, lesion composition and aortic immune cell populations were evaluated. RESULTS: Hpse-deficient mice exhibited significantly reduced atherosclerotic lesion burden in the aortic sinus and aorta at both time-points, independent of changes in plasma cholesterol levels. A significant reduction in the necrotic core size and an increase in smooth muscle cell content were also observed in advanced atherosclerotic plaques of Hpse-deficient mice. Additionally, Hpse deficiency reduced circulating and aortic levels of VCAM-1 at the initiation and progression stages of disease and circulating MCP-1 levels in the initiation but not progression stage. Moreover, the aortic levels of total leukocytes and dendritic cells in Hpse-deficient ApoE-/- mice were significantly decreased compared to control ApoE-/-mice at both disease stages. CONCLUSIONS: This study identifies Hpse as a key pro-inflammatory enzyme driving the initiation and progression of atherosclerosis and highlighting the potential of Hpse inhibitors as novel anti-inflammatory treatments for cardiovascular disease.

l-thyroxine attenuates extracellular Hsp90α-induced vascular endothelial calcification in diabetes mellitus, as revealed by parallel metabolic profiles.

BACKGROUND AND AIMS: Diabetic atherosclerotic vascular disease is characterized by extensive vascular calcification. However, an elevated blood glucose level alone does not explain this pathogenesis. We investigated the metabolic markers underlying diabetic atherosclerosis and whether extracellular Hsp90α (eHsp90α) triggers vascular endothelial calcification in this particular metabolic environment. METHODS: A parallel human/animal model metabolomics approach was used. We analyzed 40 serum samples collected from 24 patients with atherosclerosis and from the STZ-induced ApoE-/- mouse model. A multivariate statistical analysis of the data was performed, and mouse aortic tissue was collected for the assessment of plaque formation. In vitro, the effects of eHsp90α on endothelial cell calcification were assessed by serum analysis, Western blotting and immunoelectron microscopy. RESULTS: Diabetic ApoE-/- mice showed more severe plaque lesions and calcification damage. Stearamide, oleamide, l-thyroxine, l-homocitrulline and l-citrulline are biomarkers of diabetic ASVD; l-thyroxine was downregulated in both groups, and the thyroid sensitivity index was correlated with serum Hsp90α concentration. In vitro studies showed that eHsp90α increased Runx2 expression in endothelial cells through the LRP1 receptor. l-thyroxine reduced the increase in Runx2 levels caused by eHsp90α and affected the distribution and expression of LRP1 through hydrogen bonding with glutamine at position 1054 in the extracellular segment of LRP1. CONCLUSIONS: This study provides a mechanistic link between characteristic serum metabolites and diabetic atherosclerosis and thus offers new insight into the role of extracellular Hsp90α in promoting vascular calcification.

Interleukin-1 receptor accessory protein blockade limits the development of atherosclerosis and reduces plaque inflammation.

AIMS: The interleukin-1 receptor accessory protein (IL1RAP) is a co-receptor required for signalling through the IL-1, IL-33, and IL-36 receptors. Using a novel anti-IL1RAP-blocking antibody, we investigated the role of IL1RAP in atherosclerosis. METHODS AND RESULTS: Single-cell RNA sequencing data from human atherosclerotic plaques revealed the expression of IL1RAP and several IL1RAP-related cytokines and receptors, including IL1B and IL33. Histological analysis showed the presence of IL1RAP in both the plaque and adventitia, and flow cytometry of murine atherosclerotic aortas revealed IL1RAP expression on plaque leucocytes, including neutrophils and macrophages. High-cholesterol diet fed apolipoprotein E-deficient (Apoe-/-) mice were treated with a novel non-depleting IL1RAP-blocking antibody or isotype control for the last 6 weeks of diet. IL1RAP blockade in mice resulted in a 20% reduction in subvalvular plaque size and limited the accumulation of neutrophils and monocytes/macrophages in plaques and of T cells in adventitia, compared with control mice. Indicative of reduced plaque inflammation, the expression of several genes related to leucocyte recruitment, including Cxcl1 and Cxcl2, was reduced in brachiocephalic arteries of anti-IL1RAP-treated mice, and the expression of these chemokines in human plaques was mainly restricted to CD68+ myeloid cells. Furthermore, in vitro studies demonstrated that IL-1, IL-33, and IL-36 induced CXCL1 release from both macrophages and fibroblasts, which could be mitigated by IL1RAP blockade. CONCLUSION: Limiting IL1RAP-dependent cytokine signalling pathways in atherosclerotic mice reduces plaque burden and plaque inflammation, potentially by limiting plaque chemokine production.