High Cholesterol Diet Research Articles

Investigating the Antibacterial, Antioxidant, and Cholesterol-lowering Properties of Yogurt Fortified with Postbiotic of Lactobacillus acidophilus and Lactiplantibacillus plantarum in the Wistar Rat Model.

Postbiotics have gained attention in the food industry due to their functional properties and ease of use compared to their live parent cells. Postbiotics are the metabolic byproducts of probiotic microorganisms, offering advantages such as antimicrobial and anti-diabetic effects. The study aimed to explore the potential antibacterial, antioxidant, and cholesterol-lowering effects of postbiotics from Lactobacillus acidophilus (LA) and Lactiplantibacillus plantarum (LbP) through in vitro and in vivo studies. Freeze-dried postbiotics from L. acidophilus BLAC 258 and L. plantarum were used in yogurt to inhibit foodborne pathogens over a 21-day storage period at 4 °C. The cholesterol-lowering effects of the postbiotic yogurt were assessed in Wistar rats fed with Normal Basal Diet (NBD) and High Cholesterol Diet (HCD). All experiments were performed in triplicate, and the collected data were analyzed with a one-way ANOVA using SPSS v.20 (2021) software. The Tukey Honestly Significant Difference (HSD) test was used for means differences at the 95% confidence interval. The results showed that postbiotic-fortified yogurt exhibited significant antioxidant and antibacterial effects. The antioxidant capacity of the yogurt increasingly peaked at 48.81% on day 14. Also, Listeria monocytogenes counts in the postbiotic yogurt decreased by approximately 2 Log10 on day 3. High-cholesterol-fed rats receiving postbiotic yogurt experienced significant reductions in total cholesterol, triglycerides, and LDL levels. Overall results indicate that postbiotics functional yogurt might be a safe and effective strategy for managing cholesterol levels and inhibiting foodborne pathogens.

Abstract 4137414: Uncovering MLKL as a Novel Regulator of Endothelial Cells in the Splenic Niche to Repress Hematopoiesis During Atherosclerosis

Background: Atherosclerosis occurs as lipid and immune cell rich plaques deposit within the arterial wall of the heart. These immune cells are produced from hematopoietic stem and progenitor cells (HSPCs) in the bone marrow (BM) and spleen, a process known as hematopoiesis that is dictated by their microenvironment, including endothelial cells (ECs). Objective: While others have shown adverse remodeling of BM ECs during atherogenesis, whether splenic ECs show a similar dysfunction leading to exacerbated hematopoiesis has not been described. Methods: We analyzed RNA sequencing data from chow fed C57Bl/6 mice and high cholesterol diet (HCD) fed Apoe -/- mouse BM and splenic ECs obtained from published studies, as well as our own. In vivo studies were performed in mice on an atherogenic background ( Apoe -/-& Ldlr -/-) fed a HCD for 4 to 16 weeks. Knockdown of the mixed lineage kinase domain-like protein ( Mlkl KD) was achieved by weekly administration of antisense oligonucleotides (ASOs) or scrambled control (50mg/kg sc.). In vitro studies were performed in primary mouse splenic ECs transfected with siRNA. Results: Pathway analysis revealed remarkable tissue-specific responses to an atherogenic milieu, including dysregulation of Lipid Metabolism, Endocytosis and Cell Death pathways in splenic ECs. Interestingly, we previously showed that the mixed lineage kinase domain-like protein (MLKL) regulates the endocytic trafficking of lipids and cell death in macrophages. Indeed using Mlkl KD Apoe -/- mice, transplantation of Mlkl -/- BM into Ldlr -/- mice or EC-specific Mlkl -/- Apoe -/- mice, we show that loss of MLKL drives myelopoiesis and plaque development through regulation of splenic ECs. Both in vivo and in vitro , silencing Mlkl in splenic but not BM ECs potently increased lipid content and disrupted endocytosis by an accumulation of the multivesicular body marker CHMP4B, which mirror the dysregulated pathways we identified above. Furthermore, co-culture with Mlkl KD splenic ECs increased HSPC activation (pStat5) and myeloid colony formation, an effect that was lost when ECs were pre-treated with the upstream endocytosis inhibitor Dynasore. Conclusions: In conclusion, we establish a novel role for MLKL in regulating the balance of HSPCs, specifically through preservation of splenic, but not BM, ECs that repress hematopoiesis, highlighting the importance of splenic lipid metabolism and endocytosis and its impact on atherogenesis.

Abstract 4130641: The Role of Oxidized Phospholipids in Triggering Trained Immunity and Accelerating Atherosclerotic Plaque Inflammation during Cholesterol Cycling

Introduction: Oxidized phospholipids (OxPL) derived from LDL play a crucial role in the development and progression of atherosclerosis by promoting chronic inflammation and formation of foam cells. The natural antibody E06, binding to OxPL, diminishes macrophage uptake of OxLDL in vitro and decreases atherosclerosis progression in vivo. In our prior work using a model of plasma cholesterol cycling (high-low-high), resulting in atherosclerotic plaque Progression (P)-Regression (PR)-re-Progression (PRP), respectively, we observed accelerated plaque inflammation in the PRP group relative to mice with non-cycling high cholesterol. Hypothesis: OxPL promotes plaque inflammation in the cholesterol cycling model via trained immunity and that the E06 antibody will mitigate this process. Methods: We utilized transgenic "E06 mice" that expressed a single-chain variable fragment of E06 (E06-scFv) using the Apoe promoter on the Ldlr−/− background. Both E06 mice and Ldlr-/- mice were subjected to high cholesterol diets (HCD) and categorized into three groups in the cholesterol cycling model: Baseline Progression (P), PR and PRP. Plaque regression was induced by ApoB-ASO injection, which significantly lowered cholesterol levels by inhibiting LDL production. Results: As before, Ldlr-/- mice in the PRP group exhibited accelerated plaque inflammation post-regression shown by CD68 staining on aortic roots. Notably, this acceleration was significantly inhibited in the E06 mice, highlighting the protective effects of E06 against plaque re-progression. Additionally, flow cytometry of peripheral blood exhibited reduced total monocytes and Ly6Chi-monocytes (thought to become inflammatory macrophages in plaques), alongside increased Ly6Clo-monocytes (thought to become inflammation resolving macrophages in plaques) among E06 mice in the PRP group compared to Ldlr-/- mice. Ex-vivo stimulation of bone marrow cells with the inflammatory stimulus LPS demonstrated higher IL-6 levels in supernatant in Ldlr-/- mice versus E06 mice in the PRP group, suggesting OXPL-induced trained immunity in bone marrow precursors of monocytes and macrophages is involved. Conclusion: The acceleration of plaque inflammation in cholesterol cycling model was significantly inhibited in the E06 mice. These results provide insight into the increased risk of cardiovascular disease in individuals with intermittent adherence to statins who undergo cholesterol cycling.

L-aspartate ameliorates diet-induced obesity by increasing adipocyte energy expenditure.

Obesity always leads to profound perturbation of metabolome. Metabolome studies enrich the knowledge on associations between endogenous metabolites and obesity, potentially providing innovative strategies for the development of novel anti-obesity pharmacotherapy. This study aims to identify an endogenous metabolite that regulates energy expenditure and to explore its application for obesity treatment. C57BL/6 mice were fed with a high-fat and high-cholesterol (HFC) diet, comprising 60% fat and 1.2% cholesterol, for 12 weeks to induce obesity. Significant metabolites were identified in the livers of both health and obese mice through comparative hepatic metabolomics analysis. Correlation between serum or adipose L-aspartate level and body weight in obese mice, as well as human body mass index (BMI), was evaluated. In addition, saline or 200 mg/kg L-aspartate was orally administrated to HFC diet mice and HFC diet-induced obese mice for 6-7 weeks. Body weight, adipose tissue weight, glucose tolerance and liver damage were assessed to evaluate the effect on obesity prevention and treatment. Comprehensive lab animal monitoring system (CLAMS) and seahorse assay were employed to investigate the regulatory effect of L-aspartate on energy metabolism in vivo and in vitro, respectively. 3T3-L1 preadipocytes and murine white adipose tissue (WAT) were utilized to examine the impact of L-aspartate on adipocyte adipogenesis and lipogenesis and cellular signalling pathway in vitro and in vivo. L-aspartate, an approved drug for liver injury and chronic fatigue, was identified as an endogenous inducer of energy expenditure. Serum or adipose L-aspartate levels were found to be negatively correlated with the severity of obesity in both humans and mice. Administration of L-aspartate to HFC diet mice led to a significant reduction in body weight, with decreases of 14.5% in HFC diet mice and 8.5% in HFC diet-induced obese mice, respectively. In addition, the treatment improved related metabolic syndrome (Figure 2 and Figure S3). These therapeutics were associated with enhancements in whole-body energy expenditure and suppression of adipocyte adipogenesis along with activation of Adenosine 5'-monophosphate-activated protein kinase (AMPK) signalling pathway. L-aspartate may serve as a novel endogenous inducer of energy expenditure and suppressor of adipogenesis and lipogenesis along with activation of AMPK, thereby offering a promising therapeutic strategy for obesity prevention and treatment.

Metabolic Dysfunction-Associated Steatotic Liver Disease Is Accompanied by Increased Activities of Superoxide Dismutase, Catalase, and Carbonyl Reductase 1 and Levels of miR-200b-3p in Mouse Models

Metabolic dysfunction-associated steatotic liver disease (MASLD), one of the leading causes of chronic liver disorders, is characterized by hepatic lipid accumulation. MASLD causes alterations in the antioxidant defense system, lipid, and drug metabolism, resulting in impaired antioxidant status, hepatic metabolic processes, and clearance of therapeutic drugs, respectively. In the MASLD pathogenesis, dysregulated epigenetic mechanisms (e.g., histone modifications, DNA methylation, microRNAs) play a substantial role. In this study, the development of MASLD was investigated in mice fed a high-fat, high-fructose, and high-cholesterol (FFC) diet from 2 months of age, mice treated neonatally with monosodium glutamate (MSG) on a standard diet (STD), and mice treated with MSG on an FFC diet at 7 months of age and compared to control mice (C) on STD. Changes in liver histology, detoxification enzymes, epigenetic regulation, and genes involved in lipid metabolism were characterized and compared. The strong liver steatosis was observed in MSG STD, C FFC, and MSG FFC, with significant fibrosis in the latter one. Moreover, substantial alterations in hepatic lipid metabolism, epigenetic regulatory factors, and expressions and activities of various detoxification enzymes (namely superoxide dismutase, catalase, and carbonyl reductase 1) were observed in MASLD mice compared to control mice. miR-200b-3p, highly significantly upregulated in both FFC groups, could be considered as a potential diagnostic marker of MASLD. The MSG mice fed FFC seem to be a suitable model of MASLD characterized by both liver steatosis and fibrosis and substantial metabolic dysregulation.

Lactobacillus johnsonii CCFM1376 improves hypercholesterolemia in mice by regulating the composition of bile acids

Aim: Strains with high bile salt hydrolase (BSH) activity have the potential to regulate cholesterol metabolism. This study aimed to assess the alleviating effect of Lactobacillus johnsonii (L. johnsonii ) CCFM1376, a strain with high BSH activity, on mice with hypercholesterolemia and explore the mechanism of its effect through the modulation of bile acid metabolism. Methods: The BSH activity was measured using the ninhydrin method. C57BL/6J mice were given a high-cholesterol diet to induce hypercholesterolemia with simultaneous gavage of L. johnsonii CCFM1376 for 8 weeks. The biochemical parameters in the serum and liver of hypercholesterolemic mice were measured to assess the alleviating effect of L. johnsonii CCFM1376 on hypercholesterolemia. Bile acid content in the mouse liver, serum, distal ileum contents, and feces was determined using liquid chromatograph mass spectrometer (LC-MS). RNA was extracted from mouse ileum and liver, and the expression levels of relative genes implicated in bile acid metabolism were measured by quantitative real-time PCR (qPCR). Results: Compared to the model group, the group treated with L. johnsonii CCFM1376 exhibited significantly reduced levels of serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C), along with a significant increase in high density lipoproteins cholesterol (HDL-C) level. Moreover, hepatic levels of TC and LDL-C in the CCFM1376 group also decreased significantly. Furthermore, the content and amount of unconjugated bile acids in the hepatic-enteric circulation of the L. johnsonii CCFM1376 group significantly increased, and the total bile acid content in the feces also significantly increased. In the L. johnsonii CCFM1376 group, the relative expression levels of ileal farnesoid X receptor (FXR) and fibroblast growth factor 15 (FGF15) were downregulated, while the relative expression level of CYP7A1 was upregulated. Conclusion: These results indicated L. johnsonii CCFM1376 improves hypercholesterolemia in mice by regulating the composition of bile acids. This provides a reference for probiotic strategy to regulate cholesterol metabolism.

ApoE Receptor-2 R952Q Variant in Macrophages Elevates Soluble LRP1 to Potentiate Hyperlipidemia and Accelerate Atherosclerosis in Mice.

apoER2 (apolipoprotein E receptor-2) is a transmembrane receptor in the low-density lipoprotein receptor (LDLR) family with unique tissue expression. A single-nucleotide polymorphism that encodes the R952Q sequence variant has been associated with elevated plasma cholesterol levels and increased myocardial infarction risk in humans. The objective of this study was to delineate the mechanism underlying the association between the apoER2 R952Q variant and increased atherosclerosis risk. An apoER2 R952Q mouse model was generated using a CRISPR/Cas9 strategy, intercrossed with LDLR knockout mice, followed by feeding a Western-type high-fat high-cholesterol diet for 16 weeks. Atherosclerosis was investigated by immunohistology. Plasma lipids and lipid distributions among the various lipoprotein classes were analyzed by colorimetric assay. Tissue-specific effects of the R952Q sequence variant on atherosclerosis were analyzed by bone marrow transplant studies. sLRP1 (soluble low-density lipoprotein receptor-related protein 1) was measured in plasma and conditioned media from bone marrow-derived macrophages by ELISA and GST-RAP (glutathione S-transferase-receptor-associated protein) pull-down, respectively. P38 MAPK (mitogen-activated protein kinase) phosphorylation in VLDL (very-low-density lipoprotein)-treated macrophages was determined by Western blot analysis. Consistent with observations in humans with this sequence variant, the apoER2 R952Q mutation exacerbated diet-induced hypercholesterolemia, via impediment of plasma triglyceride-rich lipoprotein clearance, to accelerate atherosclerosis in Western diet-fed LDLR knockout mice. Reciprocal bone marrow transplant experiments revealed that the apoER2 R952Q mutation in bone marrow-derived cells instead of non-bone marrow-derived cells was responsible for the increase in hypercholesterolemia and atherosclerosis. Additional data showed that the apoER2 R952Q mutation in macrophages promotes VLDL-induced LRP1 (low-density lipoprotein receptor-related protein 1) shedding in a p38 MAPK-dependent manner. The apoER2 R952Q mouse model recapitulates characteristics observed in human disease. The underlying mechanism is that the apoER2 R952Q mutation in macrophages exacerbates VLDL-stimulated sLRP1 production in a p38 MAPK-dependent manner, resulting in its competition with cell surface LRP1 to impede triglyceride-rich lipoprotein clearance, thereby resulting in increased hypercholesterolemia and accelerated atherosclerosis.

Teriparatide administration is osteoanabolic but does not impact atherosclerotic plaque calcification and progression in a mouse model of menopause

Menopause exacerbates osteoporosis and increases the risk of atherosclerotic plaque rupture, leading to cardiovascular mortality. Osteoporotic women are increasingly treated with teriparatide (TPTD, 1–34 parathyroid hormone), one of the few treatments that stimulate bone formation. Despite the fact that atherosclerotic plaque calcification is a hallmark of plaque development, the impact of TPTD administration on plaque calcification remain unclear. In this context, we sought to determine the effects of TPTD administration on atherosclerosis in ovariectomized (OVX) apolipoprotein E deficient mice (ApoE−/−), as a model of postmenopausal osteoporosis. OVX ApoE−/− mice, fed a high fat, high cholesterol diet to induce atherosclerosis, received either vehicle or TPTD daily injections (40 μg/kg/d) for 4 or 10 weeks, at which points plaques are respectively weakly and heavily calcified. After sacrifice, bone remodeling was evaluated by serum markers and bone histomorphometry. Bone architectural parameters were measured by μCT. Aortic plaques were analyzed histologically, and their calcification with von Kossa staining and the calcium tracer Osteosense. Plaque inflammation and calcification markers were measured by RT-qPCR. Intermittent TPTD increased bone volume in OVX mice, due to a higher stimulation of bone formation relatively to bone resorption. These effects were not accompanied by changes in serum levels of cholesterol, triglycerides, glucose or insulin. TPTD neither significantly affected aortic plaque size, inflammation, and calcification, even if it slightly increased vascular smooth muscle cell transdifferentiation into calcifying cells. In conclusion, TPTD exhibits osteoanabolic effects in OVX ApoE−/− mice, without significantly influencing atherosclerotic plaque progression or calcification in the short term.

Docosahexaenoic acid alleviated liver lipid deposition and health damage induced by cholesterol accumulation in hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂)

Cholesterol accumulation can be a critical pathological marker and, while, the cholesterol-lowering potential of docosahexaenoic acid (DHA) has been documented extensively in mammals, its effects in fish are unclear. The present study investigated the adverse effects of cholesterol accumulation on liver health, and evaluated DHA as a potential cholesterol-lowering agent to mitigate liver damage induced by high cholesterol (HC) intake in hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂). Grouper were fed either a control diet or an HC (1.6 %) diet supplemented with varying levels of DHA (0, 0.5, 1, 2 %) for eight weeks. The HC diet significantly increased condition factor (CF), mesenteric fat index (MFI), and lipid, cholesterol and triglyceride accumulation in liver. Supplementing the HC diet with 0.5 % DHA significantly reduced CF, MFI and liver lipid contents. Moreover, HC intake increased aspartate transaminase (AST) and alanine transaminase (ALT) activities in serum, and malondialdehyde (MDA) content and the expression of gene related to inflammatory responses and apoptosis in liver. In addition, HC intake significantly reduced mitochondrial biogenesis and total antioxidant capacity in liver. However, supplementing the HC diet with 0.5 % DHA significantly decreased liver cholesterol accumulation by inhibiting cholesterol synthesis and promoting cholesterol efflux, and significantly reduced liver triglyceride content by inhibiting the expression of genes associated with lipogenesis and lipid droplet formation. Furthermore, supplementation of the HC diet with 0.5 % DHA significantly reduced the activities of ALT and AST in serum, and MDA content and the expression of genes associated with inflammation, apoptosis and antioxidation in liver, and enhanced liver mitochondrial biogenesis. Overall, the results indicated that DHA supplementation mitigated liver cholesterol accumulation by inhibiting cholesterol synthesis and promoting cholesterol efflux, and enhanced mitochondrial function, boosted antioxidant capacity, and reduced inflammation in liver of grouper fed the HC diet, ultimately alleviating liver damage caused by cholesterol accumulation. The present study elucidated the detrimental effects of cholesterol accumulation on liver health in aquatic animals and proposed DHA as a potential intervention for mitigating health issues associated with cholesterol overload.

Blumea balsamifera and Sargassum aquifolium extracts reduce fatty liver damage through lipid metabolism signalling pathways

Non-alcoholic fatty liver disease (NAFLD) is a condition marked by excessive fat accumulation in the liver and poses a significant health challenge. The leaves of Blumea balsamifera and Sargassum aquifolium have been reported to have anti-atherogenic effects. This study aims to determine the effectiveness of B. balsamifera extract (BBLE) and S. aquifolium extract (SAE) in preventing and treating liver fat accumulation in Wistar rats induced by a high-cholesterol diet through the expression of the AMP-activated protein kinase (AMPK)/ Sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor γ (PPARγ) pathway, and the leptin receptor. The experimental design of this study is laboratory-based, involving, 20 Wistar rats were fed a high-cholesterol diet over a period of 21 days. The rats were divided into four groups for the evaluation of BBLE and SAE effect: negative control (P0): induced with a high-cholesterol diet + distilled water, positive control (P1): induced with a high-cholesterol diet + simvastatin, P2: induced with a high-cholesterol diet + 4 mg/kg/bw BBLE, and P3: induced with a high-cholesterol diet + 4 mg/kg/bw BBLE and 4 mg/kg/bw SAE. The treatment duration extended over three months. Immunohistochemical analyses were performed on liver tissues to measure AMPK, SIRT1, PPARγ, and leptin receptor expression. The results indicated that leptin expression was lower in the BBLE+SAE group compared to the simvastatin group, and differences were significant between the BBLE and BBLE+SAE groups. No significant differences were noted in AMPK, SIRT1, and PPARγ expression between the simvastatin and BBLE+SAE groups (p≥0.05). In conclusion, BBLE and SAE effectively reduce liver lipid accumulation and enhance fat metabolism in hypercholesterolemic rats.

Protective effect of alpha-tocopherol on lipogenesis and oxysterol production in hypercholesterolemia-induced nonalcoholic Steatohepatitis

Despite limited number of studies, oxysterols are known to contribute to the progression of nonalcoholic steatohepatitis (NASH) by affecting lipid/cholesterol metabolism and elevating proinflammatory and profibrotic processes. Accordingly, we used a high cholesterol-mediated in vivo NASH model and aimed to determine alterations in fatty acid content and oxysterol levels together with their effects on cholesterol/lipid metabolism during the progression of the disease. We further investigated the beneficial role of α-tocopherol. To this end, in our hypercholesterolemic rabbit model, we determined fatty acid profile by GC–MS while 25-, 27-, 4β-, 7α, and 24(S)-Hydroxycholesterol levels by means of LC–MS/MS. Additionally, lipid (SREBP-1c, PPARα, PPARγ) and cholesterol metabolism-related proteins (LXRα, SREBP2 and ABCA1) were determined by immunoblotting. In conclusion, the present findings provide a complete analysis of the hepatic alterations in lipid and oxysterol profiles mediated by a high-cholesterol diet. In addition, this study explains the protective effect of α-tocopherol on lipogenesis and oxysterol production in hypercholesterolemia-induced NASH. We believe that present study will guide to novel theories in the progression and therapeutic targeting of fatty liver diseases.

Association of ethanolamine desaturase TMEM189-plasmalogen axis with the stability of atherosclerotic plaque and cardiovascular events after acute coronary syndrome

Abstract Background Patients with acute coronary syndrome (ACS) are still at high risk of recurring major adverse cardiovascular events (MACE). Disorders of lipid metabolism play an important role in the pathogenesis and progression of ACS. However, whether there are lipid components that can play an early warning role on the recurrence of MACE in patients with ACS and its potential mechanism is not yet known. Purpose To explore the changes of lipid profile before recurrent MACE in ACS patients, screen lipid molecules related to recurrent MACE, and explore their effects on pathological changes of atherosclerotic plaque. Methods We selected 44 Chinese ACS patients from the ‘Peking and Rotterdam on Mission to Reduce Coronary Artery Disease’ (PRoMISS) study. Among them, patients with recurrent MACE within 1 year after first onset of ACS were defined as MACE group, and the control group was recruited through 1:1 matching. The lipid profile of patients was analyzed by liquid chromatography-mass spectrometry. The effects of the screened potential lipid biomarkers and their synthesis enzymes were evaluated by real-time PCR, Western blot, IHC staining and ELISA. The enzyme knockout mice and ApoE knockout mice were hybridized and bred to obtain double gene knockout mice to determine whether the enzyme deficiency affects atherosclerotic plaque. Results Lipomic analysis showed that in the MACE group, plasmalogens and their 12 subtypes continued to decrease three months before the MACE recurrence. The most critical ethanolamine desaturase in the synthesis pathway of plasmalogen, transmembrane protein 189 (TMEM189) was also significantly lower in the MACE group than in the control group, and the level of TMEM189 was positively correlated with plasmalogen. Analysis of single-cell RNA sequencing results in human carotid artery plaques shows that TMEM189 is enriched in endothelial cells and smooth muscle cells (VSMC). In VSMC, treatment with oxLDL reduced TMEM189 expression. Overexpression of TMEM189 significantly improved oxLDL induced reduction in collagen synthesis, expression of alpha-smooth muscle actin (alpha-SMA) and smooth muscle protein 22 (SM22). Overexpression of TMEM189 in VSMC, significantly reduced the content of plasmalogens in the cells. After 12 weeks of feeding with high-fat and high-cholesterol diet, it was found that the content of smooth muscle cells and vulnerability index in the aortic plaque in TMEM189 -/-ApoE -/- mice were significantly decreased than in ApoE -/- mice. Conclusions Before the recurrence of MACE in ACS patients, the synthesis pathway of plasmalogen was gradually damaged, and the reduction of plasmalogen was a potential marker for predicting the recurrence of MACE in ACS patients. The deficiency of TMEM189 - plasmalogen axis aggravates atherosclerosis, it can regulate the phenotype transformation of smooth muscle cells, inhibit their collagen synthesis, and thus affect plaque stability.

Biomimetic porphyrin-lipid nanoparticles - novel nanoscale theranostics for multimodal imaging and therapy in atherosclerotic cardiovascular disease

Abstract Background High-density lipoprotein (HDL) mimetic nanoagents have unrealized potential for atherosclerosis theranostics. Porphyrin-lipid HDL mimetic nanoparticles (Por-HDL-NPs) incorporate a porphyrin-lipid conjugate which permits near infrared fluorescence imaging and positron emission tomography (PET) through chelation of Copper-64 (64Cu). The outer shell contains apolipoprotein A-I mimetic peptide R4F designed to interact with scavenger receptor class B type I (SR-BI), enabling macrophage-targeting and therapeutic effects. Purpose To investigate the multimodal imaging, macrophage-targeting and therapeutic properties of Por-HDL-NPs and applications in atherosclerotic cardiovascular disease. Methods In vitro, the cholesterol efflux capacity of PBS (control), reconstituted HDL (rHDL) and Por-HDL-NPs was determined in immortalized bone marrow-derived macrophages (iBMDMs) loaded with [³H]-cholesterol. Real-time quantitative PCR (RT-qPCR) assessed mRNA levels of inflammatory mediators. ELISAs and Western blotting measured changes in protein levels. Apolipoprotein (Apo)e-/- mice were fed high-cholesterol diet (HCD) for 6 weeks, for early-stage plaque, and 13 weeks for the unstable plaque model in which two partial stenoses were made in the right carotid artery. PET and fluorescence (IVIS, flow cytometry, microscopy) imaging identified Por-HDL-NPs in plaques, circulating and aortic cells. Histological techniques assessed plaque area and composition in aortic sinus and carotid artery sections. Results Por-HDL-NPs were internalized by iBMDMs, visualized via fluorescence microscopy and flow cytometry. Por-HDL-NPs increased cholesterol efflux (49%, P<0.05), compared to rHDL. Por-HDL-NPs reduced macrophage mRNA levels of Il-1b (88%), Il-18 (54%) and Ccl5 (75%), and protein secretion of IL-1β (69%) and CCL5 (82%), P<0.05. Por-HDL-NPs suppressed inflammasome components Nlrp3 (69%) and Asc (36%), and activation of inflammatory transcription factor p65-NF-κB (53%), P<0.05. SR-BI siRNA knockdown and methyl-β-cyclodextrin, revealed that the anti-inflammatory properties of Por-HDL-NPs were independent of SR-BI and cholesterol efflux. In Apoe-/- mice, PET imaging showed 64Cu-Por-HDL-NPs localized in hearts and could detect increases in plaque size over time with HCD feeding. Por-HDL-NP fluorescence was detected within aortic sinus and unstable carotid plaques, co-localized with CD68+ macrophages. Por-HDL-NP-treated mice had smaller early-stage (22%) and unstable plaques (52%) than control PBS-treated mice, P<0.05. Por-HDL-NP mice had fewer circulating (32%) and aortic monocytes (81%), and a reduction in aortic arch Rela (26%), P<0.05. Conclusions Por-HDL-NPs present as potential nanoscale theranostics for atherosclerotic cardiovascular disease. Por-HDL-NPs can detect plaques using multiple imaging modalities and exhibit atheroprotective effects.Atherosclerosis imaging with Por-HDL-NPs

Smooth muscle cell-specific deletion of S100A4 modifies smooth muscle cell fate and inflammation in murine atherosclerotic lesions

Abstract Background S100A4, a calcium-binding protein, is crucial in smooth muscle cell (SMC) phenotypic switch, yet its role in atherosclerotic plaque development and SMC plasticity remains unclear. Our previous experiments using an S100A4 neutralizing antibody approach in ApoE-/- atherosclerotic-prone mice showed reduced atherosclerotic burden but did not establish a direct link between the various S100A4-expressing cells and atherosclerosis. Methods/Results Herein, we show that aortic Oil RedO staining in ApoE-/-; S100A4-/- mice subjected to a 12-week high-cholesterol-diet (HCD) revealed reduced lesion areas compared to ApoE-/- mice (Figure 1, from 21.29% of the total aorta in ApoE-/-; S100A4+/+ mice to 13.27% in ApoE-/-; S100A4-/- mice), highlighting a pivotal role for S100A4 in atherosclerotic plaque development. We then used a lineage tracing ApoE-/- mouse model, in which we induced an SMC-specific deletion of S100A4 (SMC-S100A4Δ/Δ). After 12 weeks of HCD, SMC-S100A4Δ/Δ and control mice (SMC-S100A4wt/wt) were sacrificed, and aortas were processed for en face Oil Red O staining, immunohistochemistry, and single-cell RNA sequencing (scRNA-seq). SMC-specific deletion of S100A4 reduced the necrotic core area (from 29.75% of total plaque area in SMC-S100A4wt/wt to 18.23% in SMC-S100A4Δ/Δ mice) without affecting total atherosclerotic plaque size suggesting a more potent impact on plaque composition. ScRNA-seq analysis from SMC-S100A4Δ/Δ and SMC-S100A4wt/wt mice showed that the inflammatory macrophage-like SMC phenotype was highly suppressed in the plaque and associated with increased SMC repair phenotypes as well as a global reduction of myeloid inflammatory cells. SMCs also retained specific contractile SMC markers, namely Acta2 and Myh11 (fold change of 2.285 and 2.492, respectively) hinting towards a more stable fibrous cap. Immunofluorescence staining on aortic roots plaque (Figure 2) confirmed those results with an increase of SMCs (from 11.02% to 16.18%) as well as a-smooth muscle actin (a-SMA, Acta2)-positive SMCs (from 3.25% to 5.1%) in SMC-S100A4 Δ/Δ mice. Furthermore, the Gene Set Enrichment Analysis (GSEA) of scRNAseq data revealed that, in SMC-S100A4Δ/Δ mice, genes related to mitochondrial metabolism and oxidative respiration were highly downregulated in all SMC clusters. We investigated SMC mitochondrial fitness in vitro and showed that S100A4-/- SMCs have an increased basal oxygen consumption rate and an increased proton leak (fold change of 1.37 and 1.96 respectively) suggestive of differences in cellular metabolic adaptability. Conclusion Our research emphasizes the significant role of S100A4 in plaque development, demonstrating how SMC-derived S100A4 knockdown affects plaque evolution, reducing inflammation, and promoting stability likely through influencing SMC phenotypic switch through metabolic pathways.

Evaluation of the role of hepatic Gstm4 in diet-induced obesity and dyslipidemia

Obesity and its related diseases continue to rise worldwide, necessitating further investigation to develop new therapeutic strategies. The dysregulation of redox homeostasis is tightly associated with metabolic diseases. Glutathione, an antioxidant, acts as a cofactor for antioxidant and detoxification enzymes such as glutathione S-transferases (GSTs)—a superfamily including Gstm4. So far, the physiological role of Gstm4 remains largely unknown. Human genetics is a powerful tool to discover novel therapeutic targets for metabolic diseases. The single nucleotide polymorphism rs650985, located within the sixth intron of the human gene Gstm4, was associated with plasma lipids, indicating that targeting Gstm4 might intervene in the progression of dyslipidemia. Furthermore, we found that Gstm4 is highly expressed in the liver and enriched in hepatocytes—the parenchymal cells of the liver. We established the mouse model with the hepatic deletion of Gstm4 and found that this mouse model did not present altered body weight, serum lipid profile, or liver fat content in the context of chow or high-fat high cholesterol diet feeding, indicating that hepatic Gstm4 is dispensable for diet-induced obesity and dyslipidemia. Further analysis revealed that hepatic deletion of Gstm4 upregulates the level of protein but not mRNA of Npc1l1—a critical protein mediating cholesterol uptake, suggesting that there might be a link between Gstm4 and lipid metabolic diseases in certain contexts.

Targeting an altered sphingolipid profile with consecutive lipotoxicity as therapeutic approach to calcific aortic valve disease

Abstract Background Aortic stenosis due to calcific aortic valve disease (CAVD) is the most common valvular heart disease. In symptomatic patients, without repair the prognosis is poor. Treatment to date is based on surgery or catheter-based interventions. Pharmacological therapy options to prevent the progression of valve calcification are not available. In vascular smooth muscle cells, cellular accumulation of sphingolipids is associated with a proinflammatory response in the sense of lipotoxicity. Chronic inflammatory processes are indeed also essential for aortic valve calcification. Purpose With the subsequent goal of developing innovative treatment approaches for CAVD, we therefore aim to elucidate the unclear role of sphingolipids in the development of CAVD. Methods Human aortic valve and plasma samples of CAVD patients and controls (n=26) were analysed by liquid chromatography–mass spectrometry for lipidomics and proteomics. Human aortic valve interstitial cells (hVICs) were stimulated with ceramides. Calcification was detected by alizarin red staining. mRNA expression of bone-related proteins was determined by qPCR. NF-kB pathway was assessed by proteome profiler. Myriocin and GW4869 were applied to inhibit ceramide biosynthesis. PDTC and MCC950 were used to inhibit NF-kB Pathway and NLRP3 activation. ApoE-/- mice received a gain-of-function PCSK9 adeno-associated virus vector and fed high cholesterol diet for 14 weeks. Myriocin was applied orally over the treatment period to inhibit ceramide de novo synthesis in vivo. Murine echocardiography was used to measure transvalvular velocity and left ventricular function. Calcification degree of murine aortic valve was determined by histological staining. Results A significantly altered sphingolipid profile was observed in aortic valve tissue of CAVD patients (Fig. 1). Ceramide species e.g. Cer (17:1;2O/16:0) were increased. Verifying the biological relevance of these findings in vitro, C2-Cer (d18:1/2:0) enhanced hVIC calcification (Fig. 2). Accordingly, ALP activity and mRNA expression of osteogenic genes RUNX2, ALPL and MSX2 were increased. Furthermore, C2-Cer (d18:1/2:0) enhanced NF-kB p65 phosphorylation and NLRP3 activation, while treatment with both PDTC and MCC950 protected against C2-Cer (d18:1/2:0) induced calcification. Supporting the role of sphingolipid biosynthesis in hVIC calcification, Myriocin and GW4869 both reduced ox-LDL-induced VIC calcification which was reversed by C2-Cer(d18:1/2:0). Finally, Myriocin reduced the degree of calcification and transvalvular jet velocity of aortic valve in the PCSK9-AAV ApoE-/- mice model. Conclusion CAVD is accompanied by an accumulation of ceramides causing lipotoxicity in human aortic valve tissue. Pharmacological modulation of sphingolipid metabolism is an effective approach to prevent the development and progression of aortic valve calcification in vivo and should be considered as a future therapeutic strategy in CAVD patients.Volcano Plot of CAVD tissue lipidomicsC2 Ceramide enhances hVIC calcification

Deletion of the asialyloglycoprotein receptor-1 (ASGR1) causes atheroprotective effects in vitro and in vivo

Abstract Introduction The asialoglycoprotein receptor 1 (ASGR1) is a hepatic receptor that clears desialylated glycoproteins from the circulation. A loss-of-function mutation in ASGR1 was reported to associate with a 34% reduction in coronary artery disease (CAD) risk, suggesting a role for ASGR1 in CAD. Aim To determine the role of ASGR1 in atherosclerosis and whether deletion of ASGR1 elicits atheroprotective effects. Methods Western blotting, mass spectrometry and flow cytometry assessed ASGR1 expression in cultured macrophages or immune cells collected from the blood and aortas of wildtype mice. Bone marrow-derived macrophages (BMDMs) from wildtype and Asgr1-/- mice were subjected to cholesterol efflux and oxidised low-density lipoprotein (oxLDL) uptake in vitro functionalassays. ELISA and qPCR measured changes in lipid regulators in BMDMs. Asgr1-/- mice were crossed with atherosclerosis-prone apolipoprotein (Apo)e-/- mice (Apoe-/-Asgr1-/-). Stable plaque area was assessed histologically in the aortic sinuses of mice fed a high-cholesterol diet for 8 weeks (n=16/group). Using the tandem stenosis surgical model, unstable plaque was assessed in carotid arteries (n=10/group). Human ASGR1 was measured by ELISA in peripheral blood mononuclear cells (PBMCs) isolated from patient samples (n=18). Results Western blotting and mass spectrometry discovered ASGR1 is expressed in macrophages. Immunofluorescence identified the presence of ASGR1 in aortic sinus plaque. Flow cytometry revealed ASGR1 is expressed in both inflammatory and patrolling monocytes, neutrophils, macrophages and dendritic cells of blood and aortas. Asgr1-/- BMDMs elicited greater cholesterol efflux (+39%, P<0.05) and decreased oxLDL uptake (-15%, P<0.05), compared to wildtype BMDMs. Moreover, Asgr1-/- BMDMs had significantly higher LDL receptor protein levels (+2-fold), and Lxra (+2-fold) and Pparg (+1.5-fold) mRNA levels than wildtype BMDMs, P<0.001. Plasma from Asgr1-/- mice had lower total (-25%, P<0.05) and LDL (-36%, P<0.05) cholesterol concentrations than wildtype mice. Apoe-/-Asgr1-/- mice developed less stable plaque in aortic sinuses (-37%, P<0.001) than Apoe-/- controls, as well as smaller unstable plaques in carotid arteries (-49%, P<0.05). Finally, in a human population, ASGR1 protein levels were higher in PBMCs from patients with coronary plaque (+61%, P<0.05), than those without plaque, determined from coronary angiograms. Conclusion ASGR1 is expressed on monocytes, macrophages and in plaques, and human PBMC ASGR1 associates with coronary plaque. Deletion of ASGR1 causes atheroprotective functions in macrophages in vitro and reduced plaque burden in vivo. Our findings demonstrate ASGR1 is important in atherosclerosis with implications for ASGR1 as a therapeutic target.

Twenty-Week Dietary Supplementation with Beeswax Alcohol (BWA; Raydel®) Ameliorates High-Cholesterol-Induced Long-Term Dyslipidemia and Organ Damage in Hyperlipidemic Zebrafish in a Dose-Dependent Manner: A Comparative Analysis Between BWA and Coenzyme Q10

Background/Objectives: Beeswax alcohol (BWA; Raydel®) is a blend of six long-chain aliphatic alcohols extracted from honeybee wax and is well known for its diverse functionality and health benefits. Herein, the efficacy of a BWA dietary intervention for 20 weeks was assessed to ameliorate high-cholesterol diet (HCD)-induced dyslipidemia and adverse effects on the vital organs of adult zebrafish. Methods: Adult zebrafish were fed different high-cholesterol diets (HCDs; final concentration of 4%, w/w) supplemented with BWA (final concentrations of 0.1%, 0.5% and 1.0%, w/w) or CoQ10 (final concentration of 1.0%). Following 20 weeks of supplementation, blood and different organs (liver, kidney, testes and ovaries) were collected, and biochemical, histological and immunohistochemical analyses were performed. Results: The results demonstrate a dose-dependent effect of BWA of mitigating HCD-induced mortality in zebrafish over the 20-week supplementation period, which was noticeably better than the effect exerted by coenzyme Q10 (CoQ10). Consistently, a dose-dependent effect of BWA consumption of curtailing HCD-induced total cholesterol (TC) and triglyceride (TG) levels and increasing high-density-lipoprotein cholesterol (HDL-C) levels was noticed. Compared with CoQ10 (final concentration of 1.0%, w/w), BWA (final concentration of 1.0%, w/w) displayed a significantly better effect of mitigating HCD-induced dyslipidemia, as evidenced by 1.2-fold (p < 0.05) and 2.0-fold (p < 0.05) lower TC and TG levels and 2.4-fold (p < 0.01) higher HDL-C levels. The histological analysis revealed substantial prevention of fatty liver changes, reactive oxygen species (ROS) generation, cellular senescence and interleukin (IL)-6 production in the hepatic tissue of BWA zebrafish, which was significantly better than the effect exerted by CoQ10. Consistently, compared with CoQ10, significant 25% (p < 0.05) and 35% (p < 0.01) reductions in the HCD-induced elevated levels of the hepatic function biomarkers aspartate aminotransferase and alanine aminotransferase was observed in the BWA group. Likewise, BWA consumption efficiently ameliorated HCD-induced kidney, ovary and testis damage by inhibiting ROS generation, cellular senescence and lipid accumulation. Conclusion: Supplementation with BWA demonstrated higher therapeutic potential than that with CoQ10 to prevent dyslipidemia and organ damage associated with long-term consumption of HCDs.

Silicon-Enriched Meat Ameliorates Diabetic Dyslipidemia by Improving Cholesterol, Bile Acid Metabolism and Ileal Barrier Integrity in Rats with Late-Stage Type 2 Diabetes.

Silicon as a functional ingredient of restructured meat (RM) shows antidiabetic and hypocholesterolemic effects in a type 2 diabetes mellitus (T2DM) rat model. The present paper investigated the mechanisms involved in this cholesterol-lowering effect by studying the impact of silicon-RM consumption on bile acid (BA) and cholesterol metabolism. In addition, the main effects of cecal BA and short-chain fatty acids derived from the microbiota on intestinal barrier integrity were also tested. Rats were fed an RM high-saturated-fat, high-cholesterol diet (HSFHCD) combined with a low dose of streptozotocin plus nicotinamide injection (LD group) and for an 8 wk. period. Silicon-RM was included in the HSFHCD as a functional food (LD-Si group). An early-stage T2DM group fed a high-saturated-fat diet (ED group) was used as a reference. Silicon decreased the BA pool with a higher hydrophilic BA profile and a lower ability to digest fat and decreased the damaging effects, increasing the occludin levels and the integrity of the intestinal barrier. The ileal BA uptake and hepatic BA synthesis through CYP7A1 were reduced by FXR/FGF15 signaling activation. The silicon up-regulated the hepatic and ileal FXR and LXRα/β, improving transintestinal cholesterol (TICE), biliary BA and cholesterol effluxes. The inclusion of silicon in meat products could be used as a new therapeutic nutritional tool in the treatment of diabetic dyslipidemia.

Effect of rapamycin on hepatic metabolomics of non-alcoholic fatty liver rats based on non-targeted platform

Rapamycin (Rapa) is an inhibitor of mTOR complex, and its therapeutic effect on liver function was examined in non-alcoholic fatty liver disease (NAFLD) rats here. And the possible mechanism of Rapa in NAFLD was preliminarily elucidated based on the non-targeted metabolomics analysis. Adult male SD rats were fed with a high-fat and high-cholesterol diet (HFD) to establish NAFLD model. For Rapa group, 0.8 mg/(kg.d) Rapa was given to the HFD rats. Ultra-performance liquid chromatography and Q-Tof-mass spectrometry (UPLC and Q-TOF/MS) analysis were applied for the identification of metabolites in the serum of rats, which were annotated using Kyoto Encyclopedia of Genes and Genomes (KEGG). NAFLD rats presented with disturbed liver function, lipid metabolism and oxidative stress, but Rapa exerted a mitigating influence on the disorders. The metabolite profile data identified 579 metabolites that varied remarkably between the Rapa and HFD groups, with the main classes of amino acids and peptides, benzene, lipids and fatty acids. The differential metabolites were mainly involved in biosynthesis of cofactors, bile secretion, and glycerophospholipid metabolism were mainly enriched. In conclusion, Rapa has a potential protective effect against HFD-induced NAFLD, its hepatoprotective effect may achieved through mediating bile secretion and glycerophospholipid metabolism.