Search

Chronic activation of the adaptive immune system is a hallmark of atherosclerosis. As PI3Kδ is a key regulator of T and B cell differentiation and function, we hypothesized that alleviation of adaptive immunity by PI3Kδ inactivation may represent an attractive strategy counteracting atherogenesis. As expected, lack of hematopoietic PI3Kδ in atherosclerosis-prone Ldlr-/- mice resulted in lowered T and B cell numbers, CD4+ effector T cells, Th1 response, and immunoglobulin levels. However, despite markedly impaired peripheral pro-inflammatory Th1 cells and atheromatous CD4+ T cells, the unexpected net effect of hematopoietic PI3Kδ deficiency was aggravated vascular inflammation and atherosclerosis. Further analyses revealed that PI3Kδ deficiency impaired numbers, immunosuppressive functions, and stability of regulatory CD4+ T cells (Tregs), whereas macrophage biology remained largely unaffected. Adoptive transfer of wild-type Tregs fully restrained the atherosclerotic plaque burden in Ldlr-/- mice lacking hematopoietic PI3Kδ, whereas PI3Kδ-deficient Tregs failed to mitigate disease. Numbers of atheroprotective B-1 and pro-atherogenic B-2 cells as well as serum immunoglobulin levels remained unaffected by adoptively transferred wild-type Tregs. In conclusion, we demonstrate that hematopoietic PI3Kδ ablation promotes atherosclerosis. Mechanistically, we identified PI3Kδ signaling as a powerful driver of atheroprotective Treg responses, which outweigh PI3Kδ-driven pro-atherogenic effects of adaptive immune cells like Th1 cells.

Aim: Elevated levels of cholesterol in the bloodstream, also referred to as hypercholesterolemia, pose a significant risk for the onset of cardiovascular and cerebrovascular diseases. Oxysterols, cholesterol-derived oxidized compounds that form enzymatically or non-enzymatically, contribute to the development of atherosclerosis and coronary artery disease. This study aimed to examine the critical oxysterol levels in children and adolescents with hypercholesterolemia and explore the correlation between these levels, oxidative stress, and atherosclerosis progression., Materials and Methods: The study included 20 patients with familial hypercholesterolemia (FH) and 20 healthy individuals aged between 6 and 18 years. Participants were categorized into children (6-9 years) and adolescents (10-18 years). Pediatric and adolescent patients were selected from among subjects with LDL-C ≥ 130 mg/dL and diagnosed with heterozygous familial hypercholesterolemia (HeFH) based on the presence of mutations in the LDL receptor (LDL-R) gene. Patients with HeFH who were receiving regular atorvastatin therapy were included in the study., Results: There were no notable differences in catalase and paraoxonase (PON1) activities among the groups. However, the patient group displayed substantially higher levels of malondialdehyde (MDA) (P = 0.0108) and superoxide dismutase (SOD) activity (P = 0.0103). Compared to the healthy control group, serum chitotriosidase (CHITO) activity (P = 0.037) and chitinase 3-like protein 1 (YKL-40) levels (P = 0.0027) were significantly elevated in the patient group. Furthermore, the carotid intima-media thickness (CIMT) measurements of the patient group were significantly greater than those of the healthy group (**P < 0.0001****). The patient group exhibited significantly elevated levels of 5,6-α-epoxycholesterol, Cholestane-3β,5α,6β-triol (C-triol), and 7-ketocholesterol (7-KC), whereas 27-hydroxycholesterol (27-OHC) was significantly more abundant in the healthy group. On the other hand, while 27-OHC/Total cholesterol (Total-C) levels were significantly higher in healthy individuals, the C-Triol/Total-C ratio was significantly higher in patients. No significant differences were found between the groups in terms of 7-KC/Total-C and 5,6-α-epoxycholesterol/Total-C levels., Conclusion: This study highlights the key roles of oxysterols, oxidative stress, and macrophage activation in the development of atherosclerosis in pediatric and adolescent patients with FH. Elevated C-Triol levels in FH patients, alongside increased CIMT, point to early vascular changes despite atorvastatin therapy. In contrast, higher 27-OHC levels in healthy controls suggest differential oxysterol regulation due to cholesterol-lowering treatments in FH patients. C-Triol and 27-OHC/Total-C ratios showed potential as biomarkers to distinguish patients with FH. These findings emphasize the need for therapies targeting oxidative stress and macrophage activation in addition to cholesterol-lowering interventions., Competing Interests: Declarations Ethics approval and consent to participate This study was approved by the Ethics Committee of the Ege University Faculty of Medicine (Ethics Committee Approval No: 20-8T/31). Written informed consent was obtained from the legal guardian, and the child provided assent. All methods were performed in accordance with relevant guidelines and regulations. Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Background & Aims: Lipid metabolism disorders contribute to a range of human diseases, including liver-related pathologies. Rabbits, highly sensitive to dietary cholesterol, provide a model for understanding the development of liver disorders. Sterol regulatory element-binding protein isoform 2 (SREBP2) crucially regulates intracellular cholesterol pathways. Extra-virgin olive oil (EVOO) has shown reducing cholesterol levels and restoring liver parameters affected by HFD. The aim was to investigate the molecular impact of an HFD and supplemented with EVOO on rabbit liver cholesterol metabolism., Approach & Results: Male rabbits were assigned to dietary cohorts, including control, acute/chronic HFD, sequential HFD with EVOO, and EVOO. Parameters such as serum lipid profiles, hepatic enzymes, body weight, and molecular analyses. After 6 months of HFD, plasma and hepatic cholesterol increased with decreased SREBP2 and 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) expression. Prolonged HFD increased cholesterol levels, upregulating SREBP2 mRNA and HMGCR protein. Combining this with EVOO lowered cholesterol, increased SREBP2 mRNA, and upregulated low-density lipoprotein receptor (LDLR) expression. HFD-induced metabolic dysfunction-associated fatty liver disease was mitigated by EVOO. In conclusion, the SREBP2 system responds to dietary changes., Conclusions: In rabbits, the SREBP2 system responds to dietary changes. Acute HFD hinders cholesterol synthesis, while prolonged HFD disrupts regulation, causing SREBP2 upregulation. EVOO intake prompts LDLR upregulation, potentially enhancing cholesterol clearance and restoring hepatic alterations., 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 Elsevier Inc. All rights reserved.)

Objective: Colorectal cancer is one of the most common malignant tumors in the world, which seriously threatens human health. It is essential for the search for new oncogene targets in colorectal cancer., Methods: Samples from 57 colorectal cancer patients were collected in this study. Next-Generation Sequencing (NGS) was performed to detect gene mutation, assess Microsatellite Instability (MSI), and evaluate Tumor Mutational Burden (TMB). RNA data from 528 CRC patients from the TCGA database were analyzed., Results: A total of 57 colon cancer patients were included in this study, including 30 males and 27 females, with a mean age of 56 years. In this study, the most common mutations were APC (79 %), TP53 (61 %), TTN (48 %), KRAS (42 %), SYNE1 (28 %), MUC16 (25 %), PIK3CA (25 %), FAT4 (22 %), RYR2 (19 %), OBSCN (18 %), and ZFHX4 (18 %). Subsequently, the authors analyzed gene mutations in colorectal cancer patients according to gender, age, and TMB status. Significant differences in immune cell infiltration were found between colorectal cancer tissues and normal tissues by CIBERSORT analysis. LRP1B may serve as a potential colorectal cancer therapeutic target, and its absence leads to changes in immune cell infiltration., Conclusion: The authors described the molecular characteristics of CRC. Loss of LRP1B leads to changes in immune cell infiltration and can be used as a therapeutic target for colorectal cancer., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2024. Published by Elsevier España, S.L.U.)

In multiple myeloma (MM), while frequent mutations in driver genes are crucial for disease progression, they traditionally offer limited insights into patient prognosis. This study aims to enhance prognostic understanding in MM by analyzing pathway dysregulations in key cancer driver genes, thereby identifying actionable gene signatures. We conducted a detailed quantification of mutations and pathway dysregulations in 10 frequently mutated cancer driver genes in MM to characterize their comprehensive mutational impacts on the whole transcriptome. This was followed by a systematic survival analysis to identify significant gene signatures with enhanced prognostic value. Our systematic analysis highlighted 2 significant signatures, TP53 and LRP1B, which notably outperformed mere mutation status in prognostic predictions. These gene signatures remained prognostically valuable even when accounting for clinical factors, including cytogenetic abnormalities, the International Staging System (ISS), and its revised version (R-ISS). The LRP1B signature effectively distinguished high-risk patients within low/intermediate-risk categories and correlated with significant changes in the tumor immune microenvironment. Additionally, the LRP1B signature showed a strong association with proteasome inhibitor pathways, notably predicting patient responses to bortezomib and the progression from monoclonal gammopathy of unknown significance to MM. Through a rigorous analysis, this study underscores the potential of specific gene signatures in revolutionizing the prognostic landscape of MM, providing novel clinical insights that could influence future translational oncology research., (© The Author(s) 2024. Published by Oxford University Press.)

Background: Familial hypercholesterolemia (FH) is a frequently underdiagnosed genetic disorder characterized by elevated low-density lipoprotein (LDL) levels. Genetic testing of LDLR, APOB, and PCSK9 genes can identify variants in up to 80% of clinically diagnosed patients. However, limitations in time, scalability, and cost have hindered effective next-generation sequencing of these genes. Additionally, pharmacogenomic variants are associated with statin-induced adverse effects in FH patients. To address these challenges, we developed a multiplex primer-based amplicon sequencing approach for FH genetic testing., Methods: Multiplex primers were designed for the exons of the LDLR, APOB, and PCSK9 genes, as well as for pharmacogenomic variants rs4149056 (SLCO1B1:c.521T > A), rs2306283 (SLCO1B1:c.388A > G), and rs2231142 (ABCG2:c.421C > A). Analytical validation using samples with known pathogenic variants and clinical validation with 12 FH-suspected probands were conducted. Library preparation was based on a bead-based tagmentation method, and sequencing was conducted on the NovaSeq 6000 platform., Results: Our approach ensured no amplicon dropouts, with over 100× coverage on each amplicon. Known variants in 2 samples were successfully detected. Further, we identified one heterozygous LDLR (p.Glu228Ter) variant and 2 homozygous cases of LDLR (p.Lys294Ter) and LDLR (p.Ser177Leu) variants in patients. Pharmacogenomic analysis revealed that overall 3 patients may require reduced statin doses. Our approach offered reduced library preparation time (approximately 3 h), greater scalability, and lower costs (under $50) for FH genetic testing., Conclusions: Our method effectively sequences LDLR, APOB, and PCSK9 genes including pharmacogenomic variants that will guide appropriate screening and statin dosing, thus increasing both efficiency and affordability., (© Association for Diagnostics & Laboratory Medicine 2024. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Integrin α9β1 is known to stabilize leukocyte adhesion to the activated endothelium. We determined the role of myeloid cell α9β1 in early atherosclerosis in two models: α9Mye-KOApoe-/- or the Ldlr-/- mice transplanted with bone marrow (BM) from α9Mye-KO mice fed a high-fat "Western" diet for 4 wk. α9Mye-KOApoe-/- mice exhibited reduced early lesions in the aortae and aortic sinuses (P < 0.05 vs α9WT Apoe-/- mice). Similar results were obtained in α9Mye-KO BM→Ldlr-/- mice (P < 0.05 vs α9WT BM→Ldlr-/- mice). Reduced early atherosclerosis in α9Mye-KOApoe-/- mice was associated with decreased neutrophil and neutrophil extracellular traps (NETs) content in the aortic lesions (P < 0.05 vs α9WTApoe-/-). Vascular cell adhesion molecule-1-stimulated neutrophils from α9Mye-KO mice exhibited reduced adhesion, transmigration, and NETs formation (NETosis) (P < 0.05 vs α9WT neutrophils). Reduced NETosis was associated with decreased extracellular signal-regulated kinase phosphorylation, peptidyl arginine deiminase 4, and citrullinated histone H3 expression. In summary, genetic ablation of myeloid cell-specific α9 reduces early atherosclerosis, most likely by reducing neutrophil adhesion, transmigration, and NETosis., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for Leukocyte Biology.)

Fibroblast growth factor 21 (FGF21) is a promising target for treatment of obesity-associated diseases including metabolic dysfunction-associated steatohepatitis (MASH) and atherosclerosis. We evaluated the effects of the bispecific anti-FGF21-β klotho (KLB) agonist antibody bFKB1 in a preclinical model of MASH and atherosclerosis. Low-density lipoprotein receptor knockout (Ldlr-/-).Leiden mice received a high-fat diet for 20 weeks, followed by treatment with an isotype control antibody or bFKB1 for 12 weeks. Effects on plasma risk markers and (histo)pathology of liver, adipose tissue, and heart were evaluated alongside hepatic transcriptomics analysis. bFKB1 lowered body weight (-21%) and adipose tissue mass (-22%) without reducing food intake. The treatment also improved plasma insulin (-80%), cholesterol (-48%), triglycerides (-76%), alanine transaminase (ALT: -79%), and liver weight (-43%). Hepatic steatosis and inflammation were strongly reduced (macrovesicular steatosis -34%; microvesicular steatosis -100%; inflammation -74%) and while the total amount of fibrosis was not affected, bFKB1 did decrease new collagen formation (-49%). Correspondingly, hepatic transcriptomics and pathway analysis revealed the mechanistic background underlying these histological improvements, demonstrating broad inactivation of inflammatory and profibrotic transcriptional programs by bFKB1. In epididymal white adipose tissue, bFKB1 reduced adipocyte size (-16%) and inflammation (-52%) and induced browning, signified by increased uncoupling protein-1 (UCP1) protein expression (8.5-fold increase). In the vasculature, bFKB1 had anti-atherogenic effects, lowering total atherosclerotic lesion area (-38%). bFKB1 has strong beneficial metabolic effects associated with a reduction in hepatic steatosis, inflammation, and atherosclerosis. Analysis of new collagen formation and profibrotic transcriptional programs indicate that bFKB1 treatment may have antifibrotic potential in a longer treatment duration as well., (© 2024 The Author(s). The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)

Excessive dietary fat intake increases plasma lipid levels and has been associated with reduced bone mineral density (BMD) and increased risk of osteoporotic fracture, especially in older postmenopausal women. The objective of this study was to investigate whether there are sex-related differences in lipid metabolism that could have an impact on large-scale bone regeneration. Because ribs provide a unique exception as the only bones capable of completely regenerating large-scale defects, we used a rib resection mouse model in which human features are recapitulated. After 10 days of exposure to a low-fat diet or high-fat diet (HFD), we performed large-scale rib resection surgeries on male and female mice (6-7 weeks old) with deletion of the low-density lipoprotein (LDL) receptor (Ldlr -/- ) and age- and sex-matched wild-type (WT) mice were used as controls. Plasma analysis showed that short-term exposure to HFD significantly increases total cholesterol, LDL cholesterol, and triglycerides levels in Ldlr -/- mice but not in WT, with no differences between males and females. However, under HFD, callus bone volume was significantly reduced exclusively in male Ldlr -/- mice when compared to WT, although these differences were no longer apparent by 21 days after resection. Regardless of diet or genotype, BMD of regenerated ribs did not differ significantly between groups, although male mice typically had lower average BMD values. Together, these results suggest that short-term hyperlipidemia has transient effects on large-scale bone regeneration exclusively in male mice., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Background: Atherosclerotic cardiovascular diseases remain the leading cause of mortality in diabetic patients, with endothelial cell (EC) dysfunction serving as the initiating step of atherosclerosis, which is exacerbated in diabetes. Krüppel-like factor 11 (KLF11), known for its missense mutations leading to the development of diabetes in humans, has also been identified as a novel protector of vascular homeostasis. However, its role in diabetic atherosclerosis remains unexplored., Methods: Diabetic atherosclerosis was induced in both EC-specific KLF11 transgenic and knockout mice in the Ldlr -/- background by feeding a diabetogenic diet with cholesterol (DDC). Single-cell RNA sequencing (scRNA-seq) was utilized to profile EC dysfunction in diabetic atherosclerosis. Additionally, gain- and loss-of-function experiments were conducted to investigate the role of KLF11 in hyperglycemia-induced endothelial cell dysfunction., Results: We found that endothelial KLF11 deficiency significantly accelerates atherogenesis under diabetic conditions, whereas KLF11 overexpression remarkably inhibits it. scRNA-seq profiling demonstrates that loss of KLF11 increases endothelial-to-mesenchymal transition (EndMT) during atherogenesis under diabetic conditions. Utilizing gain- and loss-of-function approaches, our in vitro study reveals that KLF11 significantly inhibits EC inflammatory activation and TXNIP-induced EC oxidative stress, as well as Notch1/Snail-mediated EndMT under high glucose exposure., Conclusion: Our study demonstrates that endothelial KLF11 is an endogenous protective factor against diabetic atherosclerosis. These findings indicate that manipulating KLF11 could be a promising approach for developing novel therapies for diabetes-related cardiovascular complications., (© 2024. The Author(s).)

Background: Immune checkpoint inhibitor (ICI) usage has resulted in immune-related adverse events in patients with cancer, such as accelerated atherosclerosis. Of immune cells involved in atherosclerosis, the role of CCR2+ (CC motif chemokine receptor 2-positive) proinflammatory macrophages is well documented. However, there is no noninvasive approach to determine the changes of these cells in vivo following ICI treatment and explore the underlying mechanisms of immune-related adverse events. Herein, we aim to use a CCR2 (CC motif chemokine receptor 2)-targeted radiotracer and positron emission tomography (PET) to assess the aggravated inflammatory response caused by ICI treatment in mouse atherosclerosis models and explore the mechanism of immune-related adverse events., Methods: Apoe -/- mice and Ldlr -/- mice were treated with an ICI, anti-PD1 (programmed cell death protein 1) antibody, and compared with those injected with either isotype control IgG or saline. The radiotracer 64 Cu-DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid)-ECL1i (extracellular loop 1 inverso) was used for PET imaging of CCR2+ macrophages. Atherosclerotic arteries were collected for molecular characterization., Results: CCR2 PET revealed significantly higher radiotracer uptake in both Apoe -/- and Ldlr -/- mice treated with anti-PD1 compared with the control groups. The increased expression of CCR2+ cells in Apoe -/- and Ldlr -/- mice was confirmed by immunostaining and flow cytometry. Single-cell RNA sequencing revealed elevated expression of CCR2 in myeloid cells. Mechanistically, IFNγ (interferon gamma) was essential for aggravated inflammation and atherosclerotic plaque progression following anti-PD1 treatment., Conclusions: Accelerated atherosclerotic plaque inflammation triggered by anti-PD1 treatment can be noninvasively detected by 64 Cu-DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid)-ECL1i (extracellular loop 1 inverso) PET. Aggravated plaque inflammation is time- and dose-dependent and predominately mediated by IFNγ signaling. This study warrants further investigation of CCR2 PET as a noninvasive approach to visualize atherosclerotic plaque inflammation and explore the underlying mechanism following ICI treatment., Competing Interests: Y. Liu has a patent entitled Methods for Detecting CCR2 Receptors (patent number 12016935). The other authors report no conflicts.

Background: Several Previous studies indicate that consuming krill oil may aid in reducing hypercholesterolemia and improving cholesterol metabolism. Therefore, our study was designed to investigate the effectiveness of Antarctic krill oil ( Euphausia superba ) (ESKO) in combating obesity and lowering fat/lipid/cholesterol levels., Methods: The study aimed to investigate the molecular docking model targeting 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) using ESKO-derived eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and astaxanthin. In this study, histological alterations in the liver of the obesity model (ICR male mouse), obesity-related or antioxidant markers in both liver and serum, the molecular mechanisms in HepG2 cells and liver tissue, and HMGCR activity were analyzed., Results: Our findings revealed that a high-fat diet (HFD) significantly led to increased oxidative stress, obesity-related indicators, and cardiovascular-associated risk indices. However, ESKO effectively mitigated HFD-induced oxidative stress, fat accumulation, and the suppression of low-density lipoprotein receptor (LDLR) or activation of related molecular pathways. This was achieved through improvements in metabolic parameters, including CD36/liver X receptor α (LXRα)/sterol regulatory element-binding protein 1c (SREBP1c), proprotein convertase subtilsin/kexin type 9 (PCSK-9), and HMGCR, ultimately ameliorating HFD-induced hypercholesterolemia and obesity., Conclusions: These beneficial findings indicate that ESKO might have significant potential for preventing and treating obesity-related disorders.

Background: The causal relationship between familial hypercholesterolemia (FH) and various vitamin deficiencies has not yet been elucidated. Therefore, this study investigated the cause-and-effect relationship between FH and the risk of multiple vitamin deficiencies in humans., Methods: Mendelian randomization (MR) analysis was performed by extracting six datasets for FH, FH with ischemic heart disease (IHD), and vitamin deficiency (vitamin A, thiamine, other B-group vitamins, and vitamin D) from the FinnGen study, covering a total of 329,115; 316,290; 354,932; 354,949; 355,411 and 355,238 individuals, respectively., Results: FH was suggestively associated with higher odds of thiamine deficiency [inverse variance weighted odds ratio (OR IVW ) 95% confidence interval (CI): 1.62 (1.03, 2.55), P = 0.036] and vitamin D deficiencies [OR IVW CI: 1.35 (1.04, 1.75), P = 0.024], low-density lipoprotein receptor ( LDLR ) rs112898275 variant, rs11591147 and rs499883 in proprotein convertase subtilisin/kexin 9 ( PCSK9 ), rs9644862 in cyclin-dependent kinase inhibitor 2 B antisense RNA1 ( CDKN2B-AS1 ), and rs142834163 in dedicator of cytokinesis 6 ( DOCK6 ) and rs115478735 in ABO blood group ( ABO ) strongly influenced the risk of thiamine deficiency, while the rs7412 variant in apolipoprotein E ( APOE ) mostly influenced the risk of vitamin D deficiency. FH with IHD was suggestively associated with higher odds of vitamin D deficiency (OR IVW, weighted median [WM][95%CI]: 1.31 [1.05, 1.64]; 1.47 [1.10, 1.97]) ( P = 0.018; 0.010) without any single significant SNPs observed., Conclusion: FH was positively associated with increased risks of thiamine and vitamin D deficiencies, revealing a prospective and unfortunate complication of FH., 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 © 2024 Zhang, Wei, Zhou and Liu.)

The very-low-density lipoprotein receptor (VLDLR) has been reported as an entry receptor for Semliki Forest (SFV) and Eastern equine encephalitis (EEEV) alphaviruses in cell cultures. However, the role of VLDLR in alphavirus pathogenesis and the extent to which other alphaviruses can engage VLDLR remains unclear. Here, using a surface protein-targeted CRISPR-Cas9 screen, we identify VLDLR as a receptor for Western equine encephalitis virus (WEEV) and demonstrate that it promotes the infection of multiple viruses in the WEE antigenic complex. In vivo studies show that the pathogenicity of WEEV, EEEV, and SFV, but not the distantly related Venezuelan equine encephalitis virus, is markedly diminished in VLDLR-deficient mice and that mice treated with a soluble VLDLR-Fc decoy molecule are protected against disease. Overall, these results expand our understanding of the role of VLDLR in alphavirus pathogenesis and provide a potential path for developing countermeasures against alphaviruses from different antigenic complexes., Competing Interests: Declaration of interests M.S.D. is a consultant to or on the scientific advisory board for Inbios, IntegerBio, Akagera Medicines, Merck, GlaxoSmithKline, and Moderna. The Diamond laboratory has received unrelated funding support in sponsored research agreements from Emergent BioSolutions, Moderna, IntegerBio, and Vir Biotechnology. D.H.F. is a founder of Courier Therapeutics and has received unrelated funding support from Emergent BioSolutions and Mallinckrodt Pharmaceuticals., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Dyslipidemia is the most significant risk factor for cardiovascular diseases (CVDs) Secondary dyslipidemia: its treatments and association with atherosclerosis. Glob Health Med, Efficacy and safety of saroglitazar for the management of dyslipidemia: A systematic review and meta-analysis of interventional studies. The current treatment strategies for managing dyslipidemia focus on reducing low-density lipoprotein cholesterol (LDL-C) to minimize the risks of atherosclerosis and myocardial infarction (MI). Homozygous Familial Hypercholesterolemia (HoFH) is an inherited autosomal dominant disease caused by a mutation in the LDL receptor (LDLr), which can lead to extremely high levels of LDL-C The Beneficial Effect of Lomitapide on the Cardiovascular System in LDLr(-/-) Mice with Obesity, The microsomal triglyceride transfer protein inhibitor lomitapide improves vascular function in mice with obesity. Although statin therapy has been the primary treatment for dyslipidemia, HoFH patients do not respond well to statins, requiring alternative therapies. Microsomal triglyceride transfer protein (MTP) inhibition has emerged as a potential therapeutic target for treating HoFH. MTP is primarily responsible for transferring triglyceride and other lipids into apolipoprotein B (ApoB) during the assembly of very low-density lipoprotein (VLDL) particles in the liver. Lomitapide, an inhibitor of MTP, has been approved for treatingof HoFH adults. Unlike statins, lomitapide does not act on the LDLr to reduce cholesterol. Instead, lomitapide lowers the levels of ApoB-containing proteins, primarily VLDL, eventually decreasing LDL-C levels. Studies have shown that lomitapide can reduce LDL-C levels by more than 50% in patients with HoFH who have failed to respond adequately to other treatments. Lowering LDL-C levels is important for preventing atherosclerosis, reducing cardiovascular risk, improving endothelial function, and promoting overall cardiovascular health, especially for patients with HoFH Efficacy and safety of a microsomal triglyceride transfer protein inhibitor in patients with homozygous familial hypercholesterolaemia: a single-arm, open-label, phase 3 study. This review paper focuses on research findings regarding the therapeutic benefits of lomitapide, highlighting its effectiveness in lowering cholesterol levels and reducing the risk of CVDs The microsomal triglyceride transfer protein inhibitor lomitapide improves vascular function in mice with obesity., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Aims: The association and co-isolation of low-density lipoproteins (LDL) and extracellular vesicles (EVs) have been shown in blood plasma. Here we explore this relationship to better understand the role of EVs in atherogenesis., Methods and Results: Wild type (WT), PCSK9 -/- , and LDLR -/- C57BL/6 mice were used in this study. Eleven week-old male mice were fed high-fat diet (HFD) for 12 weeks or kept on normal diet until old age (22-months). Cardiac function was assessed by ultrasound, cholesterol was quantified with a colorimetric kit and circulating EVs were measured using flow cytometry. Plaques were analysed post-mortem using Oil-Red-O staining of the aortic arch. EVs were measured from platelet free blood plasma samples of normal and hypercholesterolaemic clinical patients. Based on annexin V and CD63 staining, we found a significant increase in EV levels in LDLR -/- and PCSK9 -/- mice after HFD, but CD81 showed no significant change in either group. There was no significant change in plaque formation after HFD. PCSK9 -/- mice show a favourable cardiac function after HFD. Blood cholesterol levels progressively increased during HFD, with LDLR -/- mice showing high levels while PCSK9 -/- were significantly lowered compared to WT animals. In mice at old age, similar cholesterol levels were observed as in young mice. In old age, LDLR -/- mice showed significantly increased plaques. At old age, ejection fraction was decreased in all groups of mice, as were CD63 + EVs. Similarly to mice, in patients with hypercholesterolaemia, CD63 + EVs were significantly depleted., Conclusions: This research demonstrates an inverse relationship between circulating EVs and cholesterol, making EVs a potential marker for cardiovascular disease (CVD). HFD causes reduced cardiac function, but atherosclerotic development is slowly progressing in hypercholesterolaemic models and only observed with old animals. These results also bring further evidence for the benefit of using of PCSK9 inhibitors as therapeutic agents in CVD., (© 2024. The Author(s).)

Background: Familial hypercholesterolemia (FH) is a common monogenic autosomal dominant disorder, primarily mainly caused by pathogenic mutations in the low-density lipoprotein receptor (LDLR) gene. Through phenotypic-genetic linkage analysis, two LDLR pathogenic mutations were identified in FH families: c.G1027A (p.Gly343Ser) and c.G1879A (p.Ala627Thr)., Materials and Methods: Whole exome sequencing was conducted on the proband with familial hypercholesterolemia to identify the target gene and screen for potential pathogenic mutations. The suspicious responsible mutation sites in 14 family members were analyzed using Sanger sequencing to assess genotype-phenotype correlations. Mutant and wild type plasmids were constructed and transfected into HEK293T cells to evaluate LDLR mRNA and protein expression. In parallel, bioinformatics tools were employed to predict structural and functional changes in the mutant LDLR., Results: Immunofluorescence analysis revealed no significant difference in the intracellular localization of the p.Gly343Ser mutation, whereas protein expression of the p.Ala627Thr mutation was decreased and predominantly localized in the cytoplasm. Western blotting has showed that protein expression levels of the mutant variants were markedly declined in both cell lysates and supernatants. Enzyme linked immunosorbent assay has demonstrated that LDLR protein levels in the supernatant of cell culture medium was not significant different from those of the wild-type group. However, LDLR protein levels in the cell lysate of both the Gly343Ser and Ala627Thr variants groups were significantly lower than those in the wild-type group. Bioinformatic predictions further suggested that these mutations may affect post-translational modifications of the protein, providing additional insight into the mechanisms underlying the observed reduction in protein expression., Conclusions: In this study, we identified two heterozygous pathogenic variants in the LDLR gene, c.G1027A (p.Gly343Ser) and c.G1879A (p.Ala627Thr), in a family with familial hypercholesterolemia. We also conducted preliminary investigations into the mechanisms by which these mutations contribute to disease pathology., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Hu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The molecular mechanisms by which cardiovascular risk factors promote the development of atherosclerosis are poorly understood. We have recently shown that genetic ablation of myeloid glycogen synthase kinase (GSK)-3α attenuates atherosclerotic lesion development in low-density lipoprotein receptor-deficient (Ldlr -/- ) mice. However, the precise contributions of GSK3α/β in atherogenesis are not known. The aim of this study is to investigate the effect of GSK3α and/or β deficiency on lesional inflammation and plaque vascularization. Five-week-old female Ldlr -/- mice were fed a high-fat diet for 10 weeks to establish atherosclerotic lesions. Mice were harvested at 15 weeks of age and atherosclerotic lesions were characterized. The results indicate that, in addition to significantly reducing plaque volume, GSK3α-deficiency decreases inflammation, reduces vasa vasorum density at the aortic sinus, and reduces plasma c-reactive protein (CRP) levels. GSK3β-deficiency is associated with decreased plasma CRP levels but does not affect lesional inflammation or vascularization. These results suggest GSK3α may be an applicable target for the development of novel anti-atherogenic therapies.

Deep mutational scanning enables high-throughput functional assessment of genetic variants. While phenotypic measurements from screening assays generally align with clinical outcomes, experimental noise may affect the accuracy of individual variant estimates. We developed the FUSE (functional substitution estimation) pipeline, which leverages measurements collectively within screening assays to improve the estimation of variant impacts. Drawing data from 115 published functional assays, FUSE assesses the mean functional effect per amino acid position and makes estimates for individual allelic variants. It enhances the correlation of variant functional effects from different assay platforms and increases the classification accuracy of missense variants in ClinVar across 29 genes (area under the receiver operating characteristic [ROC] curve [AUC] from 0.83 to 0.90). In UK Biobank patients with rare missense variants in BRCA1, LDLR, or TP53, FUSE improves the classification accuracy of associated phenotypes. FUSE can also impute variant effects for substitutions not experimentally screened. This approach improves accuracy and broadens the utility of data from functional screening., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background and Aims: We tested the association of polygenic risk scores (PRS) for low-density lipoprotein cholesterol (LDL-C) and coronary artery disease (CAD) with LDL-C and risk of ischemic heart disease (IHD) in the Danish general population., Methods: We included a total of 21,485 individuals from the Copenhagen General Population Study and Copenhagen City Heart Study. For everyone, LDL-PRS and CAD-PRS were calculated, each based on >400,000 variants. We also genotyped four rare variants in LDLR or APOB known to cause familial hypercholesterolemia (FH)., Results: Heterozygous carriers of FH-causing variants in APOB or LDLR had a mean LDL-C of 5.40 and 6.09 mmol/L, respectively, and an odds ratio for IHD of 2.27 (95 % CI 1.43-3.51) when compared to non-carriers. The LDL-PRS explained 13.8 % of the total variation in LDL-C in the cohort. Individuals in the lowest and highest 1 % of LDL-PRS had a mean LDL-C of 2.49 and 4.75 mmol/L, respectively. Compared to those in the middle 20-80 %, those in the lowest and highest 1 % of LDL-PRS had odds ratios for IHD of 0.58 (95 % CI, 0.38-0.88) and 1.83 (95 % CI, 1.33-2.53). The corresponding odds ratios for CAD-PRS were 0.61 (95 % CI, 0.41-0.92) and 2.06 (95 % CI, 1.49-2.85)., Conclusions: The top 1 % of LDL-PRS and CAD-PRS conferred effects on LDL-C and risk of IHD comparable to those seen for carriers of rare FH-causing variants in APOB or LDLR. These results highlight the potential value of implementing such PRS clinically., 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.)

Systemic immune responses caused by chronic hypercholesterolaemia contribute to atherosclerosis initiation, progression and complications 1 . However, individuals often change their dietary habits over time 2 , and the effects of an alternating high-fat diet (HFD) on atherosclerosis remain unclear. Here, to address this relevant issue, we developed a protocol using atherosclerosis-prone mice to compare an alternating versus continuous HFD while maintaining similar overall exposure periods. We found that an alternating HFD accelerated atherosclerosis in Ldlr -/- and Apoe -/- mice compared with a continuous HFD. This pro-atherogenic effect of the alternating HFD was also observed in Apoe -/- Rag2 -/- mice lacking T, B and natural killer T cells, ruling out the role of the adaptive immune system in the observed phenotype. Discontinuing the HFD in the alternating HFD group downregulated RUNX1 3 , promoting inflammatory signalling in bone marrow myeloid progenitors. After re-exposure to an HFD, these cells produced IL-1β, leading to emergency myelopoiesis and increased neutrophil levels in blood. Neutrophils infiltrated plaques and released neutrophil extracellular traps, exacerbating atherosclerosis. Specific depletion of neutrophils or inhibition of IL-1β pathways abolished emergency myelopoiesis and reversed the pro-atherogenic effects of the alternating HFD. This study highlights the role of IL-1β-dependent neutrophil progenitor reprogramming in accelerated atherosclerosis induced by alternating HFD., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Background and Aims: Familial hypercholesterolemia (FH) is a genetic disorder marked by high LDL cholesterol and an increased premature coronary artery disease (CAD) risk. Current dichotomous classification of LDL receptor gene (LDLR) variants may inadequately capture patient variability in LDL cholesterol levels and CAD risk. This study assessed a novel approach for determining LDLR variant severity using variant-specific LDL cholesterol percentiles., Methods: Participants of the Dutch FH cascade screening program were screened for 456 LDLR variants. For each LDLR variant carrier, a sex- and age-specific LDL cholesterol percentile was derived from the LDL cholesterol level measured at study entry, i.e. generally from the blood drawn for DNA analysis. These percentiles were used to calculate the mean LDL cholesterol percentile for each variant. Based on the variant-specific LDL cholesterol percentiles, carriers were grouped into the following LDL cholesterol strata: <75th, 75th-88th, 88th-92nd, 92nd-96.5th, 96.5th-98th, and ≥98th percentile. Additionally, variants were categorized into class 1 (LDLR deficient) and non-class 1 (often LDLR defective) variants. CAD risk between carriers in the different LDL cholesterol strata and non-carriers was compared using a Cox proportional hazard model., Results: Out of 35,067 participants, 12,485 (36 %) LDLR variant carriers (mean age 38.0 ± 20.0 years, 47.7 % male) were identified. Carriers had a 5-fold higher CAD risk compared with non-carriers. Hazard ratios for CAD increased gradually from 2.2 (95%CI 0.97-5.0) to 12.0 (95%CI 5.5-24.8) across the LDL cholesterol strata. A 7.3-fold and 3.9-fold increased CAD risk was observed in carriers of class 1 and non-class 1 LDLR variants, respectively., Conclusions: This study presents a refined approach for classifying LDLR variants based on their impact on LDL cholesterol levels, allowing for more precise, genotype-specific CAD risk estimation in FH patients compared with traditional methods., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: LFR is cofounder of Lipid Tools and reports speakers fee from Ultragenyx, Novartis, and Daiichi Sankyo. JJPK is part time CSO of New Amsterdam Pharma and part time CMO of Staten Biotech and a consultant to AgBio, Scribe, Cincor, CSL Behring, CiVi Biopharma, Draupnir, Esperion Therapeutics, Madrigal, Menarini, Omeicos, Silence Therapeutics, Sirnaomics, TTxD and North Sea Therapeutics. GKH reports research grants from the Netherlands Organization for Scientific Research (vidi 016.156.445), CardioVascular Research Initiative, European Union and the Klinkerpad fonds, institutional research support from Aegerion, Amgen, AstraZeneca, Eli Lilly, Genzyme, Ionis, Kowa, Pfizer, Regeneron, Roche, Sanofi, and The Medicines Company; speaker's bureau and consulting fees from Amgen, Aegerion, Sanofi, and Regeneron until April 2019 (fees paid to the academic institution); and part-time employment and stock holder of at Novo Nordisk A/S, Denmark since April 2019. ESGS has received ad-board/lecturing fees, paid to the institution, from: Amgen, Sanofi, Astra-Zeneca, Esperion, Daiichi Sankyo, NovoNordisk, Ionis/Akcea, Amarin. The other authors report no disclosures., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Objective: Head and neck squamous cell carcinoma (HNSCC) present a significant challenge in the medical field due to treatment resistance, which often hinders successful outcomes. The dysregulation of the LRP1B gene is linked to various cancers, but its specific role in HNSCC is poorly understood., Methods: This study investigated the link between pathogenic loss-of-function mutations in the LRP1B gene and survival outcomes in HNSCC patients. The Cancer Genome Atlas HNSCC cohort, comprised of 520 tumor and 44 normal tissues, was analyzed using cBioportal, and UALCAN tools. Expression patterns, survival outcomes, and clinical correlations of LRP1B were evaluated. In-depth analyses involved validation of mRNA expression using RT-qPCR and functional exploration using various in-silico tools., Results: Analysis of data from The Cancer Genome Atlas (TCGA) and cBioPortal revealed a high frequency (25 %) of LRP1B mutations in HNSCC patients. Notably, splice mutation, truncating mutation, and deep deletion, considered potential drivers, are commonly associated with LRP1B mutations. Patients with LRP1B mutations also exhibit poorer overall survival rates compared to those without these mutations. Furthermore, LRP1B mRNA expression is significantly reduced in HNSCC tissues compared to normal tissues and is correlated with advanced tumor stage, higher tumor grade, and nodal metastasis., Conclusion: These findings indicate that LRP1B may function as both a prognostic biomarker and a therapeutic target in HNSCC patients., 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 Elsevier Masson SAS. All rights reserved.)

The Proprotein Convertase Subtilisin Kexin of type 9 (PCSK9) has been identified in 2003 as the third gene involved in familial hypercholesterolemia. PCSK9 binds to the membrane low-density lipoprotein receptor (LDLR) and promotes its cellular internalization and lysosomal degradation. Beyond this canonical role, PCSK9 was recently described to be involved in several immune responses. However, to date, the contribution of PCSK9 in food allergy remains unknown. Here, we showed that Pcsk9 deficiency or pharmacological inhibition of circulating PCSK9 with a specific monoclonal antibody (m-Ab) protected mice against symptoms of gliadin-induced-food allergy, such as increased intestinal transit time and ear oedema. Furthermore, specific PCSK9 inhibition during the elicitation steps of allergic process was sufficient to ensure anti-allergic effects in mice. Interestingly, the protective effect of PCSK9 inhibition against food allergy symptoms was independent of the LDLR as PCSK9 inhibitors remained effective in Ldlr deficient mice. In vitro, we showed that recombinant gain of function PCSK9 (PCSK9 D374Y) increased the percentage of mature bone marrow derived dendritic cells (BMDCs), promoted naïve T cell proliferation and potentiated the gliadin induced basophils degranulation. Altogether, our data demonstrate that PCSK9 inhibition is protective against gliadin induced food allergy in a LDLR-independent manner., (Copyright © 2024. Published by Elsevier Inc.)

Objectives: To elucidate the association between genetic variants and the risk of GCA via large-scale genome-wide association studies (GWAS). In addition, to assess the causal effect of a specific molecule by employing the obtained GWAS results as genetic epidemiological tools., Methods: We applied additional variant quality control to the publicly available GWAS results from the biobanks of the UK (UKBB) and Finland (FinnGen), which comprised 532 cases vs 408 565 controls and 884 cases vs 332 115 controls, respectively. We further meta-analysed these two sets of results. We performed two-sample Mendelian randomization (MR) to test the causal effect of low-density lipoprotein (LDL) cholesterol on the risk of GCA., Results: The MHC class II region showed significant associations in UKBB, FinnGen and the meta-analysis. The VLDLR region was associated with GCA risk in the meta-analysis. The T allele of rs7044155 increased the expression of VLDLR, decreased the LDL cholesterol level and decreased the disease risk. The subsequent MR results indicated that a 1 s.d. increase in LDL cholesterol was associated with an increased risk of GCA (odds ratio 1.21, 95% CI 1.01-1.45; P = 0.04)., Conclusions: Our study identified associations between GCA risk and the MHC class II and VLDLR regions. Moreover, LDL cholesterol was suggested to have a causal effect on the risk of developing GCA., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: As a mega-biobank linked to a national healthcare system, the Million Veteran Program (MVP) can directly improve the health care of participants. To determine the feasibility and outcomes of returning medically actionable genetic results to MVP participants, the program launched the MVP Return of Actionable Results (MVP-ROAR) Study, with familial hypercholesterolemia (FH) as an exemplar actionable condition., Methods: The MVP-ROAR Study consists of a completed single-arm pilot phase and an ongoing randomized clinical trial (RCT), in which MVP participants are recontacted and invited to receive clinical confirmatory gene sequencing testing and a telegenetic counseling intervention. The primary outcome of the RCT is 6-month change in low-density lipoprotein cholesterol (LDL-C) between participants receiving results at baseline and those receiving results after 6 months., Results: The pilot developed processes to identify and recontact participants nationally with probable pathogenic variants in low-density lipoprotein receptor (LDLR) on the MVP genotype array, invite them to clinical confirmatory gene sequencing, and deliver a telegenetic counseling intervention. Among participants in the pilot phase, 8 (100%) had active statin prescriptions after 6 months. Results were shared with 16 first-degree family members. Six-month ΔLDL-C (low-density lipoprotein cholesterol) after the genetic counseling intervention was -37 mg/dL (95% CI: -12 to -61; P = .03). The ongoing RCT will determine between-arm differences in this primary outcome., Conclusion: While underscoring the importance of clinical confirmation of research results, the pilot phase of the MVP-ROAR Study marks a turning point in MVP and demonstrates the feasibility of returning genetic results to participants and their providers. The ongoing RCT will contribute to understanding how such a program might improve patient health care and outcomes., Clinical Trial Registration: ClinicalTrials.gov ID NCT04178122., (Published by Elsevier Inc.)

Rationale: Very-low-density lipoprotein receptor (VLDLR) involves in ocular neovascularization, a major cause of severe vision loss. However, the underlying molecular mechanisms were not completely clarified. Here, we aimed to investigate roles of circular RNAs (circRNAs) in VLDLR-associated ocular neovascularization., Methods: Vldlr knockout (Vldlr-/-, ko), Robo4 knockout (Robo4-/-, ko) and wild-type (WT) mice were used. Mouse model of oxygen induced retinopathy (OIR) and high-throughput sequence were performed to profile the differential expression of circRNA and transcripts. RNase R treatment, Sanger PCR sequencing and quantitative polymerase chain reaction (qPCR) were used to validate candidate circRNAs and their expression patterns. Choroidal sprouting assay ex vivo and laser induction choroid neovascularization were used to determine the expression and functions of QKI/CircSlc17a5 on choroidal neovascularization., Results: In macrophage and ocular tissues derived from Vldlr (Vldlr-/-,Vldlr ko) or Robo4 (Robo4-/-,Robo4 ko) deficiency as well as wild-type (WT) mice, Quaking (Qki) expression was significantly down-regulated in Vldlr deficiency compared to WT and Robo4 deficiency groups. Ectopic VLDLR expression or Reelin stimulation increased expression of QKI in bEnd.3 cells. Circular RNA sequencing uncovered that VLDLR regulated the biogenesis of certain circular RNAs, including the circSlc17a5. The number of Circular RNAs increased in mice treated with OIR. QKI mediated the biogenesis of circSlc17a5, which was an important regulator of choroidal angiogenesis., Conclusion: CircSlc17a5 regulated by VLDLR/QKI plays important roles in the choroidal angiogenesis., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Obesity is associated with excess lipid deposition in nonadipose tissues, leading to increased oxidative stress and insulin resistance. Very low-density lipoprotein receptor (VLDLR), a member of the LDL receptor family, binds and increases the catabolism of triglyceride-rich lipoproteins. Although VLDLR is highly expressed in the heart, its role in obesity-associated oxidative stress and insulin resistance is unclear. Here, we used lean (wild type), genetically obese leptin-deficient ( ob/ob ), and leptin-VLDLR double-null ( ob/ob -VLDLR -/- ) mice to determine the impact of VLDLR deficiency on obesity-induced oxidative stress and insulin resistance in the heart. Although insulin sensitivity and glucose uptake were reduced in the hearts of ob/ob mice, VLDLR expression was upregulated and was associated with increased VLDL uptake and excess lipid deposition. This was accompanied by an upregulation of cardiac NADPH oxidase (Nox) expression and increased production of Nox-dependent superoxides. Silencing the VLDLR in ob/ob mice had reduced VLDL uptake and prevented excess lipid deposition in the heart, in addition to a reduction of superoxide overproduction and the normalization of insulin sensitivity and glucose uptake. In isolated cardiomyocytes, VLDLR deficiency had prevented VLDL-mediated induction of Nox activity and superoxide overproduction while improving insulin sensitivity and glucose uptake. Our findings indicate that VLDLR deficiency prevents excess lipid accumulation and moderates oxidative stress and insulin resistance in the hearts of obese mice. This effect is linked to the active role of VLDLR in VLDL uptake, which triggers a cascade of events leading to increased Nox activity, superoxide overproduction, and insulin resistance. NEW & NOTEWORTHY Obesity is associated with excess lipid deposition in muscles, which is considered as a leading cause of metabolic dysfunction and oxidative stress. Cellular uptake of lipids is regulated by several membrane receptors, among which is the very low-density lipoprotein receptor (VLDLR). This article provides information on the role of VLDLR in cardiac muscle and how its expression regulates insulin resistance and oxidative stress in the obese mouse model.

Dendritic cells (DCs) undergo glycolytic reprogramming, a metabolic conversion process essential for their activation. Vitamin D has been reported to affect the function of DCs, but studies in metabolic diseases are insufficient. This study investigates the effects of in vitro 1,25-dihydroxyvitamin D3 (1,25(OH) 2 D 3 ) treatment on glycolytic reprogramming of bone marrow-derived dendritic cells (BMDCs) from control, obese, and atherosclerosis mice. Six-week-old male C57BL/6J mice were fed a control diet (CON) or a Western diet (WD), and B6.129S7-Ldlr tm1Her /J mice were fed a Western diet (LDLR -/- ) for 16 weeks. BMDCs were cultured in a medium containing 1,25(OH) 2 D 3 (10 nM) for 7 days and stimulated with lipopolysaccharide (LPS, 50 ng/mL) for 24 h. In mature BMDCs, 1,25(OH) 2 D 3 treatment decreased basal and compensatory glycolytic proton efflux rates (glycoPER), the expression of surface markers related to immune function of DCs (MHC class II, CD80, and CD86), and IL-12p70 production. In addition, mTORC1 activation and nitric oxide (NO) production were suppressed by 1,25(OH) 2 D 3 treatment in mature BMDCs. The effect of 1,25(OH) 2 D 3 treatment on IL-12p70 production and mTORC1 activity in the LDLR -/- group was greater than in the CON group. These findings suggest that vitamin D can affect the metabolic environment of BMDCs by regulating glycolytic reprogramming as well as by inducing tolerogenic phenotypes of DCs., Competing Interests: Declaration of competing interest The authors declare no conflict of interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Recent single-cell transcriptomes revealed spatiotemporal programmes of liver function on the sublobular scale. However, how sexual dimorphism affected this space-time logic remained poorly understood. We addressed this by performing scRNA-seq in the mouse liver, which revealed that sex, space and time together markedly influence xenobiotic detoxification and lipoprotein metabolism. The very low density lipoprotein receptor (VLDLR) exhibits a pericentral expression pattern, with significantly higher mRNA and protein levels in female mice. Conversely, VLDL assembly is periportally biased, suggesting a sexually dimorphic hepatic cycle of periportal formation and pericentral uptake of VLDL. In humans, VLDLR expression is also pericentral, with higher mRNA and protein levels in premenopausal women compared to similarly aged men. Individuals with low hepatic VLDLR expression show a high prevalence of atherosis in the coronary artery already at an early age and an increased incidence of heart attack., (© 2024. The Author(s).)

Familial hypercholesterolemia (FH) is a genetic disorder that results in elevated low-density lipoprotein cholesterol (LDL-C) levels, which manifest early in the first decades of life. It is a major cause of premature coronary artery disease worldwide, leading to significant public health challenges. The prevalence of genetically determined FH in patients with premature coronary artery disease remains underestimated, particularly in developing countries. This study aimed to assess the prevalence of genetically defined FH in Vietnamese patients with premature acute myocardial infarction (AMI) in the Vietnamese population. This cross-sectional study enrolled 218 consecutive patients diagnosed with premature AMI who underwent coronary angiography. The low-density lipoprotein receptor (LDLR), apolipoprotein B, and proprotein convertase subtilisin-kexin type 9 genes were analyzed by next-generation sequencing. FH was diagnosed according to Dutch Lipid Clinic Network criteria. Among the patients with premature AMI who underwent coronary angiography, the mean age was 46.9 ± 6.1 years, with a predominance of males (83.9%). The prevalence of potential FH diagnosed using Dutch Lipid Clinic Network criteria was 14.7% (definite FH, 6.0%; probable FH, 8.7%). Pathogenic or likely pathogenic variants in LDLR, apolipoprotein B, and proprotein convertase subtilisin-kexin type 9 were found in 9 of 218 patients (4.1%), all of which were causative mutations in LDLR. Patients with premature AMI and FH had significantly greater LDL-C levels (217.6 vs 125.7 mg/dL) and more severe coronary artery lesions, as assessed by the Gensini score (100.3 vs 60.5), than did those in the No FH group. The prevalence of genetically determined FH among Vietnamese patients with premature AMI is relatively high. Screening and diagnosis of hereditary conditions in patients with premature AMI are essential to improve early detection and management and reduce the burden of coronary artery disease in this population., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Dietary sodium restriction increases plasma triglycerides (TG) and total cholesterol (TC) concentrations as well as causing insulin resistance and stimulation of the renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system. Stimulation of the angiotensin II type-1 receptor (AT1) is associated with insulin resistance, inflammation, and the inhibition of adipogenesis. The current study investigated whether aerobic exercise training (AET) mitigates or inhibits the adverse effects of dietary sodium restriction on adiposity, inflammation, and insulin sensitivity in periepididymal adipose tissue. LDL receptor knockout mice were fed either a normal-sodium (NS; 1.27% NaCl) or a low-sodium (LS; 0.15% NaCl) diet and were either subjected to AET for 90 days or kept sedentary. Body mass, blood pressure (BP), hematocrit, plasma TC, TG, glucose and 24-hour urinary sodium (U Na ) concentrations, insulin sensitivity, lipoprotein profile, histopathological analyses, and gene and protein expression were determined. The results were evaluated using two-way ANOVA. Differences were not observed in BP, hematocrit, diet consumption, and TC. The LS diet was found to enhance body mass, insulin resistance, plasma glucose, TG, LDL-C, and VLDL-TG and reduce U Na , HDL-C, and HDL-TG, showing a pro-atherogenic lipid profile. In periepididymal adipose tissue, the LS diet increased tissue mass, TG, TC, AT1 receptor, pro-inflammatory macro-phages contents, and the area of adipocytes; contrarily, the LS diet decreased anti-inflammatory macrophages, protein contents and the transcription of genes related to insulin sensitivity. The AET prevented insulin resistance, but did not protect against dyslipidemia, adipose tissue pro-inflammatory profile, increased tissue mass, AT1 receptor expression, TG, and TC induced by the LS diet.

Aims: Apolipoprotein B (APOB)-containing very LDL (VLDL) production, secretion, and clearance by hepatocytes is a central determinant of hepatic and circulating lipid levels. Impairment of any of the aforementioned processes is associated with the development of multiple diseases. Despite the discovery of genes and processes that govern hepatic VLDL metabolism, our understanding of the different mechanistic steps involved is far from complete. An impediment to these studies is the lack of tractable hepatocyte-based systems to interrogate and follow APOB in cells, which the current study addresses., Methods and Results: To facilitate the cellular study of VLDL metabolism, we generated human hepatic HepG2 and Huh-7 cell lines in which CRISPR/Cas9-based genome engineering was used to introduce the fluorescent protein mNeonGreen into the APOB gene locus. This results in the production of APOB100-mNeon that localizes predominantly to the endoplasmic reticulum (ER) and Golgi by immunofluorescence and electron microscopy imaging. The production and secretion of APOB100-mNeon can be quantitatively followed in medium over time and results in the production of lipoproteins that are taken up via the LDL receptor pathway. Importantly, the production and secretion of APOB-mNeon is sensitive to established pharmacological and physiological treatments and to genetic modifiers known to influence VLDL production in humans. As a showcase, we used HepG2-APOBmNeon cells to interrogate ER-associated degradation of APOB. The use of a dedicated sgRNA library targeting all established membrane-associated ER-resident E3 ubiquitin ligases led to the identification of SYNV1 as the E3 responsible for the degradation of poorly lipidated APOB in HepG2 cells., Conclusions: In summary, the engineered cells reported here allow the study of hepatic VLDL assembly and secretion and facilitate spatiotemporal interrogation induced by pharmacologic and genetic perturbations., Competing Interests: Conflict of interest: none declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Hematopoietic stem cells (HSCs) react to various stress conditions. However, it is unclear whether and how HSCs respond to severe anemia. Here, we demonstrate that upon induction of acute anemia, HSCs rapidly proliferate and enhance their erythroid differentiation potential. In severe anemia, lipoprotein profiles largely change and the concentration of ApoE increases. In HSCs, transcription levels of lipid metabolism-related genes, such as very low-density lipoprotein receptor (Vldlr), are upregulated. Stimulation of HSCs with ApoE enhances their erythroid potential, whereas HSCs in Apoe knockout mice do not respond to anemia induction. Vldlr high HSCs show higher erythroid potential, which is enhanced after acute anemia induction. Vldlr high HSCs are epigenetically distinct because of their low chromatin accessibility, and more chromatin regions are closed upon acute anemia induction. Chromatin regions closed upon acute anemia induction are mainly binding sites of Erg. Inhibition of Erg enhanced the erythroid differentiation potential of HSCs. Our findings indicate that lipoprotein metabolism plays an important role in HSC regulation under severe anemic conditions., (© 2024. The Author(s).)

Emerging studies suggest that various parental exposures affect offspring cardiovascular health, yet the specific mechanisms, particularly the influence of paternal cardiovascular disease (CVD) risk factors on offspring cardiovascular health, remain elusive. The present study explores how paternal hypercholesterolemia affects offspring atherosclerosis development using the LDL receptor-deficient (LDLR-/-) mouse model. We found that paternal high-cholesterol diet feeding led to significantly increased atherosclerosis in F1 female, but not male, LDLR-/- offspring. Transcriptomic analysis highlighted that paternal hypercholesterolemia stimulated proatherogenic genes, including Ccn1 and Ccn2, in the intima of female offspring. Sperm small noncoding RNAs (sncRNAs), particularly transfer RNA-derived (tRNA-derived) small RNAs (tsRNAs) and rRNA-derived small RNAs (rsRNAs), contribute to the intergenerational transmission of paternally acquired metabolic phenotypes. Using a newly developed PANDORA-Seq method, we identified that high-cholesterol feeding elicited changes in sperm tsRNA/rsRNA profiles that were undetectable by traditional RNA-Seq, and these altered sperm sncRNAs were potentially key factors mediating paternal hypercholesterolemia-elicited atherogenesis in offspring. Interestingly, high-cholesterol feeding altered sncRNA biogenesis-related gene expression in the epididymis but not testis of LDLR-/- sires; this may have led to the modified sperm sncRNA landscape. Our results underscore the sex-specific intergenerational effect of paternal hypercholesterolemia on offspring cardiovascular health and contribute to the understanding of chronic disease etiology originating from parental exposures.

Hypercholesterolemia forms the background of several cardiovascular pathologies. LDL receptor-knockout (LDLR-KO) mice kept on a high-fat diet (HFD) develop high cholesterol levels and atherosclerosis (AS). Cannabinoid type 1 receptors (CB 1 Rs) induce vasodilation, although their role in cardiovascular pathologies is still controversial. We aimed to reveal the effects of CB 1 Rs on vascular function and remodeling in hypercholesterolemic AS-prone LDLR-KO mice. Experiments were performed on a newly established LDLR and CB 1 R double-knockout (KO) mouse model, in which KO and wild-type (WT) mice were kept on an HFD or a control diet (CD) for 5 months. The vascular functions of abdominal aorta rings were tested with wire myography. The vasorelaxation effects of acetylcholine (Ach, 1 nM-1 µM) were obtained after phenylephrine precontraction, which was repeated with inhibitors of nitric oxide synthase (NOS) and cyclooxygenase (COX), Nω-nitro-L-arginine (LNA), and indomethacin (INDO), respectively. Blood pressure was measured with the tail-cuff method. Immunostaining of endothelial NOS (eNOS) was carried out. An HFD significantly elevated the cholesterol levels in the LDLR-KO mice more than in the corresponding WT mice (mean values: 1039 ± 162 mg/dL vs. 91 ± 18 mg/dL), and they were not influenced by the presence of the CB 1 R gene. However, with the defect of the CB 1 R gene, damage to the Ach relaxation ability was moderated. The blood pressure was higher in the LDLR-KO mice compared to their WT counterparts (systolic/diastolic values: 110/84 ± 5.8/6.8 vs. 102/80 ± 3.3/2.5 mmHg), which was significantly elevated with an HFD (118/96 ± 1.9/2 vs. 100/77 ± 3.4/3.1 mmHg, p < 0.05) but attenuated in the CB 1 R-KO HFD mice. The expression of eNOS was depressed in the HFD WT mice compared to those on the CD, but it was augmented if CB 1 R was knocked out. This newly established double-knockout mouse model provides a tool for studying the involvement of CB 1 Rs in the development of hypercholesterolemia and atherosclerosis. Our results indicate that knocking out the CB 1 R gene significantly attenuates vascular damage in hypercholesterolemic mice.

Subretinal fibrosis permanently impairs the vision of patients with neovascular age-related macular degeneration. Despite emerging evidence revealing the association between disturbed metabolism in retinal pigment epithelium (RPE) and subretinal fibrosis, the underlying mechanism remains unclear. In the present study, single-cell RNA sequencing revealed, prior to subretinal fibrosis, genes in mitochondrial fatty acid oxidation are downregulated in the RPE lacking very low-density lipoprotein receptor (VLDLR), especially the rate-limiting enzyme carnitine palmitoyltransferase 1A (CPT1A). We found that overexpression of CPT1A in the RPE of Vldlr -/- mice suppresses epithelial-to-mesenchymal transition and fibrosis. Mechanistically, TGFβ 2 induces fibrosis by activating a Warburg-like effect, i.e. increased glycolysis and decreased mitochondrial respiration through ERK-dependent CPT1A degradation. Moreover, VLDLR blocks the formation of the TGFβ receptor I/II complex by interacting with unglycosylated TGFβ receptor II. In conclusion, VLDLR suppresses fibrosis by attenuating TGFβ 2 -induced metabolic reprogramming, and CPT1A is a potential target for treating subretinal fibrosis., (© 2024. The Author(s).)

Atherosclerotic cardiovascular disease is closely correlated with elevated low density lipoprotein-cholesterol. In feeding state, glucose and insulin activate mammalian target of rapamycin 1 that phosphorylates the deubiquitylase ubiquitin-specific peptidase 20 (USP20). USP20 then stabilizes HMG-CoA reductase, thereby increasing lipid biosynthesis. In this study, we applied clinically approved lipid nanoparticles to encapsulate the siRNA targeting Usp20. We demonstrated that silencing of hepatic Usp20 by siRNA decreased body weight, improved insulin sensitivity, and increased energy expenditure through elevating UCP1. In Ldlr -/- mice, silencing Usp20 by siRNA decreased lipid levels and prevented atherosclerosis. This study suggests that the RNAi-based therapy targeting hepatic Usp20 has a translational potential to treat metabolic disease., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: In early atherosclerosis, circulating LDLs (low-density lipoproteins) traverse individual endothelial cells by an active process termed transcytosis. The CANTOS trial (Canakinumab Antiinflammatory Thrombosis Outcome Study) treated advanced atherosclerosis using a blocking antibody for IL-1β (interleukin-1β); this significantly reduced cardiovascular events. However, whether IL-1β regulates early disease, particularly LDL transcytosis, remains unknown., Methods: We used total internal reflection fluorescence microscopy to quantify transcytosis by human coronary artery endothelial cells exposed to IL-1β. To investigate transcytosis in vivo, we injected wild-type and knockout mice with IL-1β and LDL to visualize acute LDL deposition in the aortic arch., Results: Exposure to picomolar concentrations of IL-1β induced transcytosis of LDL but not of albumin by human coronary artery endothelial cells. Surprisingly, expression of the 2 known receptors for LDL transcytosis, ALK-1 (activin receptor-like kinase-1) and SR-BI (scavenger receptor BI), was unchanged or decreased. Instead, IL-1β increased the expression of the LDLR (LDL receptor); this was unexpected because LDLR is not required for LDL transcytosis. Overexpression of LDLR had no effect on basal LDL transcytosis. However, knockdown of LDLR abrogated the effect of IL-1β on transcytosis rates while the depletion of Cav-1 (caveolin-1) did not. Since LDLR was necessary but overexpression had no effect, we reasoned that another player must be involved. Using public RNA sequencing data to curate a list of Rab (Ras-associated binding) GTPases affected by IL-1β, we identified Rab27a. Overexpression of Rab27a alone had no effect on basal transcytosis, but its knockdown prevented induction by IL-1β. This was phenocopied by depletion of the Rab27a effector JFC1 (synaptotagmin-like protein 1). In vivo, IL-1β increased LDL transcytosis in the aortic arch of wild-type but not Ldlr -/- or Rab27a-deficient mice. The JFC1 inhibitor nexinhib20 also blocked IL-1β-induced LDL accumulation in the aorta., Conclusions: IL-1β induces LDL transcytosis by a distinct pathway requiring LDLR and Rab27a; this route differs from basal transcytosis. We speculate that induction of transcytosis by IL-1β may contribute to the acceleration of early disease., Competing Interests: None.

Lipid-lowering drugs, especially statins, are extensively utilized in clinical settings for the prevention of hyperlipidemia. Nevertheless, prolonged usage of current lipid-lowering medications is associated with significant adverse reactions. Therefore, it is imperative to develop novel therapeutic agents for lipid-lowering therapy. In this study, a chenodeoxycholic acid and lactobionic acid double-modified polyethyleneimine (PDL) nanocomposite as a gene delivery vehicle for lipid-lowering therapy by targeting the liver, are synthesized. Results from the in vitro experiments demonstrate that PDL exhibits superior transfection efficiency compared to polyethyleneimine in alpha mouse liver 12 (AML12) cells and effectively carries plasmids. Moreover, PDL can be internalized by AML12 cells and rapidly escape lysosomal entrapment. Intravenous administration of cyanine5.5 (Cy5.5)-conjugated PDL nanocomposites reveals their preferential accumulation in the liver compared to polyethyleneimine counterparts. Systemic delivery of low-density lipoprotein receptor plasmid-loaded PDL nanocomposites into mice leads to reduced levels of low-density lipoprotein cholesterol (LDL-C) and triglycerides (TC) in the bloodstream without any observed adverse effects on mouse health or well-being. Collectively, these findings suggest that low-density lipoprotein receptor plasmid-loaded PDL nanocomposites hold promise as potential therapeutics for lipid-lowering therapy., (© 2024 Wiley‐VCH GmbH.)

Background: Dyslipidemia increases cardiovascular disease risk, the leading cause of death worldwide. Under time-restricted feeding (TRF), wherein food intake is restricted to a consistent window of <12 hours, weight gain, glucose intolerance, inflammation, dyslipidemia, and hypercholesterolemia are all reduced in mice fed an obesogenic diet. LDLR (low-density lipoprotein receptor) mutations are a major cause of familial hypercholesterolemia and early-onset cardiovascular disease., Methods: We subjected benchmark preclinical models, mice lacking LDLR-knockout or ApoE knockout to ad libitum feeding of an isocaloric atherogenic diet either ad libitum or 9 hours TRF for up to 13 weeks and assessed disease development, mechanism, and global changes in hepatic gene expression and plasma lipids. In a regression model, a subset of LDLR-knockout mice were ad libitum fed and then subject to TRF., Results: TRF could significantly attenuate weight gain, hypercholesterolemia, and atherosclerosis in mice lacking the LDLR-knockout mice under experimental conditions of both prevention and regression. In LDLR-knockout mice, increased hepatic expression of genes mediating β-oxidation during fasting is associated with reduced VLDL (very-low-density lipoprotein) secretion and lipid accumulation. Additionally, increased sterol catabolism coupled with fecal loss of cholesterol and bile acids contributes to the atheroprotective effect of TRF. Finally, TRF alone or combined with a cholesterol-free diet can reduce atherosclerosis in LDLR-knockout mice. However, mice lacking ApoE, which is an important protein for hepatic lipoprotein reuptake do not respond to TRF., Conclusions: In a preclinical animal model, TRF is effective in both the prevention and regression of atherosclerosis in LDLR knockout mice. The results suggest TRF alone or in combination with a low-cholesterol diet can be a lifestyle intervention for reducing cardiovascular disease risk in humans., Competing Interests: S. Panda is the author of the book “The Circadian Code and The Circadian Diabetes Code” and serves on the scientific advisory board of Hooke London. J.L. Witztum received consulting fees from Ionis Pharmaceuticals Inc; royalties/patent beneficiary from the University of California San Diego; and ownership interest from Kleanthi, and Oxitope.

Introduction: Lecithin cholesterol acyltransferase (LCAT) plays a crucial role in acyl-esterifying cholesterol in plasma, which is essential for reverse cholesterol transport (RCT). Previous studies indicated that its activity on both α and β lipoproteins interpret its effects on lipoproteins for many controversial investigations of atherosclerosis., Objectives: To better understand the relationship between LCAT, diet-induced dyslipidemia and atherosclerosis, we developed a double knockout (LCAT-/-&LDLR-/-, DKO) hamster model to evaluate the specific role of LCAT independent of LDL clearance effects., Methods: Plasma triglyceride (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), and free cholesterol (FC) levels were measured using biochemical reagent kits. FPLC was performed to analyze the components of lipoproteins. Apolipoprotein content was assessed using western blotting (WB). The hamsters were fed a high cholesterol/high fat diet (HCHFD) to induce atherosclerosis. Oil Red O staining was employed to detect plaque formation. Peritoneal macrophages were studied to investigate the effects of LCAT on cholesterol uptake and efflux., Results: On HCHFD, DKO hamsters exhibited significantly elevated levels of TG and FC, while HDL-C was nearly undetectable without affecting TC levels, as compared to low-density lipoprotein receptor (LDLR)-deficient (LDLR-/-, LKO) hamsters. Lipoprotein profiling revealed a marked increase in plasma chylomicron/very low-density lipoprotein (CM/VLDL) fractions, along with an unexpected reduction in LDL fraction in DKO hamsters. Furthermore, DKO hamsters displayed aggravated atherosclerotic lesions in the aorta, aortic root, and coronary artery relative to LKO hamsters, attributed to a pro-atherogenic lipoprotein profile and impaired cholesterol efflux in macrophages., Conclusions: Our study demonstrates the beneficial role of LCAT in inhibiting atherosclerotic development and highlights the distinctive lipid metabolism characteristics in hamsters with familial hypercholesterolemia., 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. Production and hosting by Elsevier B.V.)

There was no significant difference in the composition and content of fatty acids in eggs among different breeds initially, but following the supplementation of flaxseed oil, Dwarf Layer were observed to deposit more n-3 polyunsaturated fatty acid (PUFA) in eggs. Currently, there is limited research on the mechanisms underlying the differences in egg composition among different breeds. Therefore, in this study, 150 twenty-four-wk-old hens of each breed, including the Dwarf Layer and White Leghorn, were fed either a basal diet or a diet supplemented with 2.5% flaxseed oil. After 28 d, eggs and liver samples were collected to determine fatty acid composition, and serum, liver, intestine, and follicles were collected for subsequent biochemical, intestinal morphology, and lipid metabolism-related genes expression analysis. Duodenal contents were collected for microbial analysis. The results showed that there was no significant difference in the content and deposition efficiency of total n-3 PUFA in the liver of the 2 breeds, but the content and deposition efficiency of total n-3 PUFA in the egg of Dwarf Layer were significantly higher than those of White Leghorn after feeding flaxseed oil. Flaxseed oil and breeds did not have significant effects on cholesterol (CHO), free fatty acids (NEFA), low-density lipoprotein (LDL), and estrogen (E 2 ) levels. After feeding with flaxseed oil, the villus height and the villus-to-crypt ratio in both breeds were increased and duodenal crypt depth was decreased. The villus-to-crypt ratio (4.78 vs. 3.60) in the duodenum of Dwarf Layer was significantly higher than that in White Leghorn after feeding with flaxseed oil. Flaxseed oil can impact the gut microbiota in the duodenum and reduce the microbiota associated with fatty acid breakdown, such as Romboutsia, Subdolibranulum, Lachnochlostridium, and Clostridium. This may mean that less ALA can be decomposed and more ALA can be absorbed into the body. Additionally, after feeding flaxseed oil, the mRNA levels of elongation enzymes 5 (ELOVL5), fatty acid desaturase 1 (FADS1), and fatty acid transporter 1 (FATP1) in the liver of Dwarf Layer were significantly higher than those in White Leghorn, while the mRNA levels of peroxisome proliferator-activated receptor alpha (PPAR), carnitine palmitoyl transferase 1 (CPT1), Acyl CoA oxidase 1 (ACOX1), and Acyl-CoA synthetase (ACSL) were significantly lower than those in White Leghorn. The mRNA level of FABP1 in the duodenum of Dwarf Layer was significantly higher than that of White Leghorn, while the mRNA level of FATP1 was significantly lower than that of White Leghorn. The protein levels of ELOVL5 in the liver of Dwarf Layer and very low-density lipoprotein receptor (VLDLR) in the follicles were significantly higher than those of White Leghorn. In summary, after feeding flaxseed oil, the higher ratio of villus height to crypt depth in Dwarf Layer allows more α-linolenic acid (ALA) to be absorbed into the body. The higher mRNA expression of FADS1, ELOVL5, and FATP1, as well as the higher protein expression of ELOVL5 in the liver of Dwarf Layer enhance the conversion of ALA into DHA. The higher protein expression of VLDLR in follicles of Dwarf Layer allows more n-3 PUFA to deposit in the follicles. These combined factors contribute to the Dwarf Layer's ability to deposit higher levels of n-3 PUFA in eggs, as well as improving the deposition efficiency of n-3 PUFA., Competing Interests: DISCLOSURES The authors declare no conflicts of interest., (Copyright © 2024. Published by Elsevier Inc.)

Intracellular cholesterol metabolism is regulated by the SREBP-2 and LXR signaling pathways. The effects of inflammation on these molecular mechanisms remain poorly studied, especially at the blood-brain barrier (BBB) level. Tumor necrosis factor α (TNFα) is a proinflammatory cytokine associated with BBB dysfunction. Therefore, the aim of our study was to investigate the effects of TNFα on BBB cholesterol metabolism, focusing on its underlying signaling pathways. Using a human in vitro BBB model composed of human brain-like endothelial cells (hBLECs) and brain pericytes (HBPs), we observed that TNFα increases BBB permeability by degrading the tight junction protein CLAUDIN-5 and activating stress signaling pathways in both cell types. TNFα also promotes cholesterol release and decreases cholesterol accumulation and APOE secretion. In hBLECs, the expression of SREBP-2 targets (LDLR and HMGCR) is increased, while ABCA1 expression is decreased. In HBPs, only LDLR and ABCA1 expression is increased. TNFα treatment also induces 25-hydroxycholesterol (25-HC) production, a cholesterol metabolite involved in the immune response and intracellular cholesterol metabolism. 25-HC pretreatment attenuates TNFα-induced BBB leakage and partially alleviates the effects of TNFα on ABCA1, LDLR, and HMGCR expression. Overall, our results suggest that TNFα favors cholesterol efflux via an LXR/ABCA1-independent mechanism at the BBB, while it activates the SREBP-2 pathway. Treatment with 25-HC partially reversed the effect of TNFα on the LXR/SREBP-2 pathways. Our study provides novel perspectives for better understanding cerebrovascular signaling events linked to BBB dysfunction and cholesterol metabolism in neuroinflammatory diseases., 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 Author(s). Published by Elsevier B.V. All rights reserved.)

Hepatocytes synthesize a vast number of glycoproteins found in their membranes and secretions, many of which contain O-glycans linked to Ser/Thr residues. As the functions and distribution of O-glycans on hepatocyte-derived membrane glycoproteins and blood glycoproteins are not well understood, we generated mice with a targeted deletion of Cosmc (C1Galt1c1) in hepatocytes. Liver glycoproteins in WT mice express typical sialylated core 1 O-glycans (T antigen/CD176) (Galβ1-3GalNAcα1-O-Ser/Thr), whereas the Cosmc knockout hepatocytes (HEP-Cosmc-KO) lack extended O-glycans and express the Tn antigen (CD175) (GalNAcα1-O-Ser/Thr). Tn-containing glycoproteins occur in the sera of HEP-Cosmc-KO mice but not in WT mice. The LDL-receptor (LDLR), a well-studied O-glycosylated glycoprotein in hepatocytes, behaves as a ∼145kD glycoprotein in WT liver lysates, whereas it is reduced to ∼120 kDa in lysates from HEP-Cosmc-KO mice. Interestingly, the expression of the LDLR, as well as HMG-CoA reductase, which is typically altered in response to dysregulated cholesterol metabolism, are similar between WT and HEP-Cosmc-KO mice, indicating no significant effect by Cosmc deletion on either LDLR stability or cholesterol metabolism. Consistent with this, we observed no detectable phenotype in the HEP-Cosmc-KO mice regarding development, appearance or aging compared to WT. These results provide surprising, novel information about the pathway of O-glycosylation in the liver., (© The Author(s) 2024. Published by Oxford University Press.)

Background: Thromboembolic events, including myocardial infarction (MI) or stroke, caused by the rupture or erosion of unstable atherosclerotic plaques are the leading cause of death worldwide. Although most mouse models of atherosclerosis develop lesions in the aorta and carotid arteries, they do not develop advanced coronary artery lesions. Moreover, they do not undergo spontaneous plaque rupture with MI and stroke or do so at such a low frequency that they are not viable experimental models to study late-stage thrombotic events or to identify novel therapeutic approaches for treating atherosclerotic disease. This has stymied the development of more effective therapeutic approaches for reducing these events beyond what has been achieved with aggressive lipid lowering. Here, we describe a diet-inducible mouse model that develops widespread advanced atherosclerosis in coronary, brachiocephalic, and carotid arteries with plaque rupture, MI, and stroke., Methods: We characterized a novel mouse model with a C-terminal mutation in the scavenger receptor class B, type 1 (SR-BI), combined with Ldlr knockout (designated SR-BI ∆CT/∆CT / Ldlr -/- ). Mice were fed Western diet (WD) for 26 weeks and analyzed for MI and stroke. Coronary, brachiocephalic, and carotid arteries were analyzed for atherosclerotic lesions and indices of plaque stability. To validate the utility of this model, SR-BI ∆CT/∆CT / Ldlr -/- mice were treated with the drug candidate AZM198, which inhibits myeloperoxidase, an enzyme produced by activated neutrophils that predicts rupture of human atherosclerotic lesions., Results: SR-BI ∆CT/∆CT / Ldlr -/- mice show high (>80%) mortality rates after 26 weeks of WD feeding because of major adverse cardiovascular events, including spontaneous plaque rupture with MI and stroke. Moreover, WD-fed SR-BI ∆CT/∆CT / Ldlr -/- mice displayed elevated circulating high-sensitivity cardiac troponin I and increased neutrophil extracellular trap formation within lesions compared with control mice. Treatment of WD-fed SR-BI ∆CT/∆CT / Ldlr -/- mice with AZM198 showed remarkable benefits, including >90% improvement in survival and >60% decrease in the incidence of plaque rupture, MI, and stroke, in conjunction with decreased circulating high-sensitivity cardiac troponin I and reduced neutrophil extracellular trap formation within lesions., Conclusions: WD-fed SR-BI ∆CT/∆CT / Ldlr -/- mice more closely replicate late-stage clinical events of advanced human atherosclerotic disease than previous models and can be used to identify and test potential new therapeutic agents to prevent major adverse cardiac events.

Introduction: Hypercholesterolemia is associated with increased inflammation and impaired serotonin neurotransmission, potentially contributing to depressive symptoms. However, the role of statins, particularly pitavastatin, in modulating serotonin transporter (SERT) function within this context remains underexplored. This study aimed to investigate whether pitavastatin counteracts the neurobiological effects of hypercholesterolemia., Methods: Low-density lipoprotein receptor knockout (LDLR -/- ) mice on a C57BL/6 background were assigned to three groups: a control group fed a standard chow diet, a group fed a high-fat diet (HFD), and a third group fed a high-fat diet supplemented with pitavastatin (HFD + Pita). We evaluated the effects of HFD with or without pitavastatin on lipid profiles, inflammatory markers, and SERT availability using small-animal positron emission tomography (PET) scans with the radioligand 4-[ 18 F]-ADAM over a 20-week period., Results: Pitavastatin treatment in HFD-fed mice significantly reduced both total cholesterol and LDL cholesterol levels in HFD-fed mice compared to those on HFD alone. Elevated inflammatory markers such as IL-1α, MCP-1/CCL2, and TNF-α in HFD mice were notably decreased in the HFD + Pita group. PET scans showed reduced SERT availability in the brains of HFD mice; however, pitavastatin improved this in brain regions associated with mood regulation, suggesting enhanced serotonin neurotransmission. Additionally, the sucrose preference test showed a trend towards increased preference in the HFD + Pita group compared to the HFD group, indicating a potential reduction in depressive-like behavior., Conclusion: Our findings demonstrate that pitavastatin not only lowers cholesterol and reduces inflammation but also enhances SERT availability, suggesting a potential role in alleviating depressive symptoms associated with hypercholesterolemia. These results highlight the multifaceted benefits of pitavastatin, extending beyond its lipid-lowering effects to potentially improving mood regulation and neurotransmitter function., (© 2024. The Author(s).)

Background: Activation of brown adipose tissue (BAT) has gained attention due to its ability to dissipate energy and counteract cardiometabolic diseases (CMDs)., Methods: This study investigated the consequences of cold exposure on the BAT and liver proteomes of an established CMD mouse model based on LDL receptor-deficient (LdlrKO) mice fed a high-fat, high-sucrose, high-cholesterol diet for 16 weeks. We analyzed energy metabolism in vivo and performed untargeted proteomics on BAT and liver of LdlrKO mice maintained at 22 °C or 5 °C for 7 days., Results: We identified several dysregulated pathways, miRNAs, and transcription factors in BAT and liver of cold-exposed Ldlrko mice that have not been previously described in this context. Networks of regulatory interactions based on shared downstream targets and analysis of ligand-receptor pairs identified fibrinogen alpha chain (FGA) and fibronectin 1 (FN1) as potential crosstalk factors between BAT and liver in response to cold exposure. Importantly, genetic variations in the genes encoding FGA and FN1 have been associated with cardiometabolic-related phenotypes and traits in humans., Discussion: This study describes the key factors, pathways, and regulatory networks involved in the crosstalk between BAT and the liver in a cold-exposed CMD mouse model. These findings may provide a basis for future studies aimed at testing whether molecular mediators, as well as regulatory and signaling mechanisms involved in tissue adaption upon cold exposure, could represent a target in cardiometabolic disorders., (© 2024. The Author(s).)

Pancreatic ductal adenocarcinoma (PDAC) poses a significant threat due to its tendency to evade early detection, frequent metastasis, and the subsequent challenges in devising effective treatments. Processes that govern epithelial-mesenchymal transition (EMT) in PDAC hold promise for advancing novel therapeutic strategies. SAMD1 (SAM domain-containing protein 1) is a CpG island-binding protein that plays a pivotal role in the repression of its target genes. Here, we revealed that SAMD1 acts as a repressor of genes associated with EMT. Upon deletion of SAMD1 in PDAC cells, we observed significantly increased migration rates. SAMD1 exerts its effects by binding to specific genomic targets, including CDH2, encoding N-cadherin, which emerged as a driver of enhanced migration upon SAMD1 knockout. Furthermore, we discovered the FBXO11-containing E3 ubiquitin ligase complex as an interactor and negative regulator of SAMD1, which inhibits SAMD1 chromatin-binding genome-wide. High FBXO11 expression in PDAC is associated with poor prognosis and increased expression of EMT-related genes, underlining an antagonistic relationship between SAMD1 and FBXO11. In summary, our findings provide insights into the regulation of EMT-related genes in PDAC, shedding light on the intricate role of SAMD1 and its interplay with FBXO11 in this cancer type., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Simon et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)