CAIP-Induced ROS Production Contributes to Sustaining Atherosclerotic Process Associated with Helicobacter cinaedi Infection through Macrophages and Endothelial Cells Activation.

Several lines of evidence have linked the intestinal bacterium Helicobacter cinaedi with the pathogenesis of atherosclerosis, identifying the Cinaedi Antigen Inflammatory Protein (CAIP) as a key virulence factor. Oxidative stress and inflammation are crucial in sustaining the atherosclerotic process and oxidized LDL (oxLDL) uptake. Primary human macrophages and endothelial cells were pre-incubated with 10 µM diphenyl iodonium salt (DPI) and stimulated with 20 µg/mL CAIP. Lectin-like oxLDL receptor (LOX-1) expression was evaluated by FACS analysis, reactive oxygen species (ROS) production was measured using the fluorescent probe H2DCF-DA, and cytokine release was quantified by ELISA assay. Foam cells formation was assessed by Oil Red-O staining, and phosphorylation of p38 and ERK1/2 MAP kinases and NF-κB pathway activation were determined by Western blot. This study demonstrated that CAIP triggered LOX-1 over-expression and increased ROS production in both macrophages and endothelial cells. Blocking ROS abrogated LOX-1 expression and reduced LDL uptake and foam cells formation. Additionally, CAIP-mediated pro-inflammatory cytokine release was significantly affected by ROS inhibition. The signaling pathway induced by CAIP-induced oxidative stress led to p38 MAP kinase phosphorylation and NF-κB activation. These findings elucidate the mechanism of action of CAIP, which heightens oxidative stress and contributes to the atherosclerotic process in H. cinaedi-infected patients.

In Vitro Modulation of Human Foam Cell Formation and Adhesion Molecules Expression by Ginger Extracts Points to Potential Cardiovascular Preventive Agents.

Recent findings from the World Heart Federation (WHF) reported a significant increase in cardiovascular disease (CVD)-related deaths, highlighting the urgent need for effective prevention strategies. Atherosclerosis, a key precursor to CVD, involves the accumulation of low-density lipoprotein (LDL) and its oxidation within the endothelium, leading to inflammation and foam cell formation. Ginger extracts, known for their antioxidative and anti-inflammatory properties, show promise in preventing CVD initiation by inhibiting LDL oxidation and reducing foam cell formation. Our results revealed that the active fractions in ginger extracts had antioxidative effects, particularly fractions D and E. Further research is needed to identify the active compounds in these fractions and understand their mechanisms of action. In this context, microfluidic models could offer insights into the effects of ginger on monocyte recruitment in a more physiologically relevant context. Overall, ginger extracts represent a potential novel treatment for preventing CVD initiation, but additional studies are necessary to identify the active molecules in these fractions.

Design, Synthesis, and Characterization of Novel Cannabidiol-Based Derivatives with Potent Antioxidant Activities.

In recent years, extensive research has focused on cannabidiol (CBD), a well-studied non-psychoactive component of the plant-derived cannabinoids. CBD has shown significant therapeutic potential for treating various diseases and disorders, including antioxidants and anti-inflammatory effects. Due to the promising therapeutic effect of CBD in a wide variety of diseases, synthetic derivatization of this compound has attracted the attention of drug discovery in both industry and academia. In the current research, we focused on the derivatization of CBD by introducing Schiff base moieties, particularly (thio)-semicarbazide and aminoguanidine motifs, at the 3-position of the olivetolic ring. We have designed, synthesized, and characterized new derivatives based on CBD's framework, specifically aminoguanylhydrazone- and (thio)-semicarbazones-CBD-aldehyde compounds. Their antioxidant potential was assessed using FRAP and DPPH assays, alongside an evaluation of their effect on LDL oxidation induced by Cu2+ and AAPH. Our findings suggest that incorporating the thiosemicarbazide motif into the CBD framework produces a potent antioxidant, warranting further investigation.

The senescent marker p16INK4a enhances macrophage foam cells formation.

BACKGROUND: The senescence marker p16INK4a, which constitutes part of the genome 9p21.3 cardiovascular disease (CVD) risk allele, is believed to play a role in foam cells formation. This study aims to unravel the role of p16INK4a in mediating macrophage foam cells formation, cellular senescence, and autophagy lysosomal functions. METHODS: The mammalian expression plasmid pCMV-p16INK4a was used to induce p16INK4a overexpression in THP-1 macrophages. Next, wild-type and p16INK4a-overexpressed macrophages were incubated with oxidized LDL to induce foam cells formation. Lipids accumulation was evaluated using Oil-red-O staining and cholesterol efflux assay, as well as expression of scavenger receptors CD36 and LOX-1. Cellular senescence in macrophage foam cells were determined through analysis of senescence-associated ß-galactosidase activity and other SASP factors expression. Meanwhile, autophagy induction was assessed through detection of autophagosome formation and LC3B/p62 markers expression. RESULTS: The findings showed that p16INK4a enhanced foam cells formation with increased scavenger receptors CD36 and LOX-1 expression and reduced cholesterol efflux in THP-1 macrophages. Besides, ß-galactosidase activity was enhanced, and SASP factors such as IL-1α, TNF-α, and MMP9 were up-regulated. In addition, p16INK4a is also shown to induce autophagy, as well as increasing autophagy markers LC3B and p62 expression. CONCLUSIONS: This study provides insights on p16INK4a in mediating macrophages foam cells formation, cellular senescence, and foam cells formation.

[Pharmacodynamics of Qingxin Jieyu Granules for treatment of atherosclerosis and its regulatory mechanism for lipid metabolism].

OBJECTIVE: To elucidate the therapeutic mechanism of Qingxin Jieyu Granule (QXJYG) against atherosclerosis (AS) based on network pharmacology. METHODS: The major targets and pathways of QXJYG against AS were analyzed using network pharmacology. Rat models of AS established by high-fat feeding combined with intraperitoneal vitamin D3 injection were treated daily with normal saline, atorvastatin (13.15 mg/kg), or QXJYG at 0.99, 1.98, and 3.96 g/kg for 8 weeks (n=6). Ultrasound and HE staining were used to assess the function and pathologies of the abdominal aorta. Blood lipids and serum levels of Ang Ⅱ, ET-1, TXA2, PGI2, and ox-LDL of the rats were detected using an automatic biochemical analyzer or ELISA. The expressions of LOX-1, PPARγ, RXRα, p-P65, VCAM-1 and ICAM-1 in the abdominal aorta were detected with immunohistochemistry. RESULTS: The rat models of AS showed obvious abdominal aorta wall thickening, increased pulse wave velocity and pulse index, decreased inner diameter of the abdominal aorta, elevated levels of TC, LDL-C, Ang Ⅱ, ET-1 and TXA2, and lowered levels of HDL-C and PGI2. QXJYG and atorvastatin treatment of the rat models significantly alleviated histopathological changes of the abdominal aorta, decreased serum levels of TC, LDL-C, Ang Ⅱ, ET-1 and TXA2, and increased the levels of HDL-C and PGI2. Network pharmacology study suggested the therapeutic effect of QXJYG against AS was mediated by regulating lipid metabolism, PPAR and NF-κB pathways. Consistently, treatments with QXJYG were found to significantly decrease ox-LDL level and LOX-1, P-P65, VCAM-1 and ICAM-1 protein expressions while increasing PPARγ and RXRα expressions in the aorta of AS rats. CONCLUSION: QXJYG alleviates lipid metabolism disorder and improves histopathological changes of the abdominal aorta of AS rats possibly by lowering ox-LDL level, reducing LOX-1 expression, activating PPARγ and RXRα, and inhibiting P65 phosphorylation to reduce VCAM-1 and ICAM-1 expression in the aorta.

Targeting STIM1 Contributes to Alleviating Remodeling of Vascular Smooth Muscle Cells in Atherosclerosis.

BACKGROUND: Remodeling of vascular smooth muscle cells (VSMCs), as a pathological hallmark of cardiovascular diseases, is related to the molecular rewiring of Calcium signaling, which induces upregulation of stromal interaction molecule (STIM) proteins. This study analyzed the influence of STIM1 proteins on the remodeling of VSMCs in atherosclerosis (AS). METHODS: After oxidized low-density lipoprotein (ox-LDL) treatment and transfection, VSMC viability, migration, and invasion were separately measured using Cell Counting Kit-8, Scratch assay, and Transwell assay. An animal AS model was constructed, and histological analysis via hematoxylin-eosin staining was conducted on the aorta. RESULTS: Ox-LDL promoted expression of STIM1 and Orai calcium release-activated calcium modulator 1 (Orai1). STIM1 or Orai1 downregulation suppressed viability, migration, invasion, and phenotypic switching of ox-LDL-treated VSMCs, whereas STIM1 or Orai1 upregulation had opposite effects. Orai1 level was upregulated by STIM1 overexpression. Orai1 silencing reversed the effects of STIM1 overexpression in VSMCs. STIM1 deficiency alleviated AS and regulated expression of Orai1 and phenotypic switch-related factors in vivo. CONCLUSION: STIM1 deficiency suppresses viability, migration, invasion, and phenotypic switching of ox-LDL-induced VSMCs and alleviates AS by inhibiting Orai1.

Blood Lipoproteins Shape the Phenotype and Lipid Content of Early Atherosclerotic Lesion Macrophages: A Dual-Structured Mathematical Model.

Macrophages in atherosclerotic lesions exhibit a spectrum of behaviours or phenotypes. The phenotypic distribution of monocyte-derived macrophages (MDMs), its correlation with MDM lipid content, and relation to blood lipoprotein densities are not well understood. Of particular interest is the balance between low density lipoproteins (LDL) and high density lipoproteins (HDL), which carry bad and good cholesterol respectively. To address these issues, we have developed a mathematical model for early atherosclerosis in which the MDM population is structured by phenotype and lipid content. The model admits a simpler, closed subsystem whose analysis shows how lesion composition becomes more pathological as the blood density of LDL increases relative to the HDL capacity. We use asymptotic analysis to derive a power-law relationship between MDM phenotype and lipid content at steady-state. This relationship enables us to understand why, for example, lipid-laden MDMs have a more inflammatory phenotype than lipid-poor MDMs when blood LDL lipid density greatly exceeds HDL capacity. We show further that the MDM phenotype distribution always attains a local maximum, while the lipid content distribution may be unimodal, adopt a quasi-uniform profile or decrease monotonically. Pathological lesions exhibit a local maximum in both the phenotype and lipid content MDM distributions, with the maximum at an inflammatory phenotype and near the lipid content capacity respectively. These results illustrate how macrophage heterogeneity arises in early atherosclerosis and provide a framework for future model validation through comparison with single-cell RNA sequencing data.

Simvastatin Inhibits the Formation of NETs by the Mac-1 Pathway to Reduce Hepatic Ischemia-Reperfusion Injury under High-Fat Conditions.

BACKGROUND: Hyperlipidemia is one of the main causes of aggravated hepatic ischemia-reperfusion injury (IRI). Simvastatin (SIM), a lipid-lowering drug, has been shown to effectively alleviate IRI caused by hyperlipidemia. However, the regulatory mechanism by which SIM alleviates hyperlipidemia-induced hepatic IRI is still not clear. This study aims to explore the potential mechanisms of SIM in inhibiting hyperlipidemia-induced hepatic IRI, providing new therapeutic strategies for the alleviation of hepatic IRI. METHODS: An animal model of hyperlipidemia was induced by feeding mice a high-fat diet for 8 weeks. Subsequently, a hepatic IRI animal model of hyperlipidemia was established by occluding the hepatic artery and portal vein for one hour, followed by reperfusion for 6 or 12 h. Enzyme linked immunosorbent assay, Western blotting, hematoxylin-eosin (H&E) staining, immunohistochemistry, immunofluorescence, and Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling assay, were used to evaluate liver injury, neutrophil extracellular traps (NETs) formation, and related molecular mechanisms. RESULTS: Hepatic IRI was accelerated by hyperlipidemia, which enhanced the expression of oxidized low-density lipoprotein (oxLDL) and Macrophage-1antigen (Mac-1), leading to the promotion of NETs formation and apoptosis of liver cells. The administration of simvastatin reduced the levels of oxLDL and Mac-1, decreased the formation of NETs, and alleviated hepatic IRI induced by hyperlipidemia. CONCLUSIONS: Simvastatin reduced hyperlipidemia-induced hepatic IRI by inhibiting the formation of NETs through the regulation of the oxLDL/Mac-1 pathway.

A Potential Link between Myeloperoxidase Modified LDL, Atherosclerosis and Depression.

Atherosclerosis is a chronic inflammatory disease that involves modified low-density lipoproteins (LDL) which play a pivotal role in the initiation and progression of the disease. Myeloperoxidase oxidized LDL (Mox-LDL) is considered to be the most patho-physiologically relevant type of modified LDL and has been reported to be ubiquitously present in atheroma plaques of patients with atherosclerosis. Besides its involvement in the latter disease state, Mox-LDL has also been shown to be implicated in the pathogenesis of various illnesses including sleep disorders, which are in turn associated with heart disease and depression in many intricate ways. Meanwhile, we have recently shown that lox-1-mediated Mox-LDL signaling modulates neuroserpin activity in endothelial cells, which could have major implications that go beyond the pathophysiology of stroke and cerebrovascular disease (CD). Of note is that tissue plasminogen activator (tPA), which is the main target of neuroserpin in the brain, has a crucial function in the processing of brain-derived neurotrophic factor (BDNF) into its mature form. This factor is known to be involved in major depressive disorder (MDD) development and pathogenesis. Since tPA is more conventionally recognized as being involved in fibrinolytic mechanisms, and its effect on the BDNF system in the context of MDD is still not extensively studied, we speculate that any Mox-LDL-driven change in the activity of tPA in patients with atherosclerosis may lead to a decrease in the production of mature BDNF, resulting in impaired neural plasticity and depression. Deciphering the mechanisms of interaction between those factors could help in better understanding the potentially overlapping pathological mechanisms that regulate disease processes in CD and MDD, supporting the possibility of novel and common therapeutic opportunities for millions of patients worldwide.

Preparation of ceftiofur-encapsulated hen-egg low-density lipoproteins and their antibacterial effects on intracellular Staphylococcus aureus.

Hen egg low-density lipoprotein (heLDL), as alternative of serum-derived LDL, was used as drug delivery system of ceftiofur (CEF). The CEF-loaded hen egg low-density lipoprotein (CEF-heLDL) with complete apolipoprotein structure and high drug loading rate was synthesized, possesses suitable particle size. CEF-heLDL undergoes cellular uptake and colocalizes with lysosomes in vitro. An intracellular infection model of the bovine endometrial epithelial cells and a coeliac-induced inflammation model of mice by Staphylococcus aureus (S. aureus) were established, and significantly lower intracellular S. aureus levels of CEF-heLDL group than CEF-free group (P < 0.001) was observed. The antibacterial efficacy was sustained for 24 h. Up to 400 mg/kg of CEF-heLDL, 20 times the clinical practice, were intraperitoneally administrated, and no significant toxicity signs on mice were observed. HeLDLs is an effective, safe, and cheap drug carrier, and could also be used for transmembrane delivering other antibiotics.

The in vitro effect of myeloperoxidase oxidized LDL on THP-1 derived macrophages.

Cardiovascular diseases (CVDs) linked to atherosclerosis remains the leading cause of death worldwide. Atherosclerosis is primarily caused by the accumulation of oxidized forms of low density lipoprotein (LDL) in macrophages (MΦs) in the subendothelial layer of arteries leading to foam cell and fatty streak formation. Many studies suggest that LDL that is modified by myeloperoxidase (MPO) is a key player in the development of atherosclerosis. MΦs can adopt a variety of functional phenotypes that include mainly the proinflammatory M1 and the anti-inflammatory M2 MΦ phenotypes which are both implicated in the process of atherogenesis. In fact, MΦs that reside in atherosclerostic lesions were shown to express a variety of phenotypes ranging between the M1- and M2 MΦ types. Recently, we pointed out the involvement of MPO oxidized-LDL (Mox-LDL) in increasing inflammation in MΦs by reducing their secretion of IL-10. Since little is known about Mox-LDL-mediated pro-atherosclerostic responses in MΦs, our study aimed at analyzing the in vitro effects of Mox-LDL at this level through making use of the well-established model of human THP-1-derived Mφs. Our results demonstrate that Mox-LDL has no effect on apoptosis, reactive oxygen species (ROS) generation and cell death in our cell model; yet, interestingly, our results show that Mox-LDL is significantly engulfed at a higher rate in the different MΦ subtypes supporting its key role in foam cell formation during the progression of the disease as well as previous data that were generated using another primary MΦ cell model of atherosclerosis.

Computational and experimental investigations of a novel aptamer targeting oxidized low-density lipoprotein.

Oxidized low-density lipoprotein (oxLDL) induces the formation of atherosclerotic plaques. Apolipoprotein B100 (apoB100) is a crucial protein component in low-density lipoprotein (LDL), which includes oxLDL. The oxidation of amino acids and subsequent alterations in their structure generate oxLDL, which is a significant biomarker for the initial phases of coronary artery disease. This study employed molecular docking and molecular dynamics utilizing the MM/GBSA method to identify aptamers with a strong affinity for oxidized apoB100. Molecular docking and molecular dynamics were performed on two sequences of the aptamer candidates (aptamer no.11 (AP11: 5'-CTTCGATGTAGTTTTTGTATGGGGTGCCCTGGTTCCTGCA-3') and aptamer no.26 (AP26: 5'-GCGAACTCGCGAATCCAGAACGGGCTCGGTCCCGGGTCGA-3')), yielding respective binding free energies of -149.08 kcal/mol and -139.86 kcal/mol. Interaction modeling of the simulation revealed a strong hydrogen bond between the AP11-oxidized apoB100 complexes. In an aptamer-based gold nanoparticle (AuNP) aggregation assay, AP11 exhibits a color shift from red to purple with the highest absorbance ratio, and shows strong binding affinity to oxLDL, correlating with the simulation model results. AP11 demonstrated the potential for application as a novel recognition element in diagnostic methodologies and may also contribute to future advancements in preventive therapies for coronary artery disease.

Restoration of miR-299-3p promotes efferocytosis and ameliorates atherosclerosis via repressing CD47 in mice.

Atherosclerotic plaque formation is largely attributed to the impaired efferocytosis, which is known to be associated with the pathologic upregulation of cluster of differentiation 47 (CD47), a key antiphagocytic molecule. By gene expression omnibus (GEO) datasets analysis, we identified that four miRNAs are aberrantly downregulated in atherosclerosis, coronary artery disease, and obesity. Of them, hsa-miR-299-3p (miR-299-3p) was predicted to target the 3'UTR of human CD47 mRNA by bioinformatics analysis. Further, we demonstrated that miR-299-3p negatively regulates CD47 expression by binding to the target sequence "CCCACAU" in the 3'UTR of CD47 mRNA through luciferase reporter assay and site-directed mutagenesis. Additionally, we found that miR-299-3p was downregulated by ~32% in foam cells in response to oxidized low-density lipoprotein (ox-LDL) stimulation, thus upregulating CD47 and contributing to the impaired efferocytosis. Whereas, restoration of miR-299-3p reversed the ox-LDL-induced upregulation of CD47, thereby facilitating efferocytosis. In high-fat diet (HFD) fed ApoE-/- mice, we discovered that miR-299-3p was downregulated thus leading to upregulation of CD47 in abdominal aorta. Conversely, miR-299-3p restoration potently suppressed HFD-induced upregulation of CD47 and promoted phagocytosis of foam cells by macrophages in atherosclerotic plaques, thereby reducing necrotic core, increasing plaque stability, and mitigating atherosclerosis. Conclusively, we identify miR-299-3p as a negative regulator of CD47, and reveal a molecular mechanism whereby the ox-LDL-induced downregulation of miR-299-3p leads to the upregulation of CD47 in foam cells thus contributing to the impaired efferocytosis in atherosclerosis, and propose miR-299-3p can potentially serve as an inhibitor of CD47 to promote efferocytosis and ameliorate atherosclerosis.

Increased vascular deposition of oxidized LDL in untreated juvenile dermatomyositis.

BACKGROUND: Juvenile dermatomyositis (JDM) is a systemic vasculopathy associated with metabolic derangements and possible increased risk for premature atherosclerosis. Oxidation of low-density lipoprotein (LDL) in the endothelium is an early step in atherosclerotic plaque formation. It is not known if oxidized LDL is altered in children with untreated JDM. The deposition of oxidized LDL in the vasculature of muscle biopsies (MBx) from patients with untreated JDM and pediatric controls was assessed. FINDINGS: Frozen tissue sections of MRI-directed MBx from 20 female children with untreated JDM and 5 female controls were stained with DAPI and fluorescently labeled antibodies against von Willebrand factor (vWF) and LDL oxidized by copper (oxLDL). Blood vessels were identified by positive vWF staining, and total fluorescence of oxLDL within the vessel walls was measured. Children with untreated JDM had increased deposition of oxLDL in the walls of muscle vasculature compared to healthy children (difference in means ± SEM = 19.86 ± 8.195, p = 0.03). Within the JDM cohort, there was a trend towards increased oxLDL deposition with longer duration of untreated disease (r = 0.43, p = 0.06). There was no significant correlation found between oxLDL deposition and markers of acute JDM disease activity including disease activity scores or muscle enzymes. CONCLUSIONS: This study found increased deposition of oxLDL within blood vessels of children with untreated JDM supporting the concern that these children are at increased risk for premature atherosclerosis from chronic exposure to vascular oxLDL. This study highlights the importance of early diagnosis and treatment initiation to ameliorate cardiovascular damage.

Huanglian Jiedu Decoction enhances the stability of atherosclerotic plaques through SLC2A1-mediated efferocytosis.

BACKGROUND: Atherosclerotic (AS) plaques require a dense necrotic core and a robust fibrous cap to maintain stability. While previous studies have indicated that the traditional Chinese medicine Huang Lian Jie Du Decoction (HLJDD) possesses the capability to stabilize AS plaques, the underlying mechanisms remain obscure. This study aims to delve deeper into the potential mechanisms by which HLJDD improves AS through an integrated research strategy. METHODS: Leveraging an AS model in ApoE-/- mice exposed to a high-fat diet (HFD), we scrutinized the therapeutic effects of HLJDD using microscopic observations, oil red O staining, HE staining and Masson staining. Employing comprehensive techniques of network pharmacology, bioinformatics, and molecular docking, we elucidated the mechanism by which HLJDD stabilizes AS plaques. In vitro experiments, utilizing ox-LDL-induced macrophages and apoptotic vascular smooth muscle cells (VSMCs), assessed the impact of HLJDD on efferocytosis and the role of SLC2A1. RESULTS: In vivo experiments showcased the efficacy of HLJDD in reducing the quantity of aortic plaques, diminishing lipid deposition, and enhancing plaque stability in AS mice. Employing network pharmacology and machine learning, we pinpointed SLC2A1 as a crucial regulatory target. Molecular docking further validated the binding of HLJDD components with SLC2A1. The experiments demonstrated a dose-dependent upregulation in SLC2A1 expression by HLJDD, amplifying efferocytosis. Importantly, this effect was reversed by the SLC2A1 inhibitor STF-31, highlighting the pivotal role of SLC2A1 as a target. CONCLUSION: The HLJDD can modulate macrophage efferocytosis by enhancing the expression levels of SLC2A1, thereby improving the stability of atherosclerotic plaques.

Association between NKILA and some apoptotic gene expression in atherosclerosis.

Oxidized light-density lipoprotein (ox-LDL) causes endothelial dysfunction, which is an important determinant of atherogenesis, and subsequently leads to apoptosis. Atherosclerosis is one of the most significant cardiovascular diseases (CVDs) threatening human health and causes death worldwide. Recently, long noncoding RNAs (lncRNAs) have been suggested to involved in vascular biology. Ox-LDL activates nuclear factor kappa-B (NF-κB), and NF-κB interacting lncRNA (NKILA) inhibits NF-κB signaling. In this study, the hypothesis is that NKILA may regulate endothelial cell (EC) apoptosis and, therefore, play a role in the pathogenesis of atherosclerosis. This hypothesis is based on the knowledge that EC apoptosis contributes to atherosclerosis development and that NKILA has become a prominent lncRNA in CVDs. The expression of Bcl-2-associated X protein (BAX), caspase 9 (CASP9), cytochrome c (Cyt c, CYCS), apoptotic protease activating factor 1 (APAF1), and B-cell lymphoma 2 (BCL-2) genes in human umbilical vein endothelial cells (HUVEC) treated with ox-LDL and transfected with NKILA siRNA was analyzed using quantitative reverse transcription polymerase chain reaction (RT-qPCR). BAX, CASP9, CYCS, APAF1, and BCL-2 gene expression was downregulated in ox-LDL and NKILA siRNA-treated HUVEC. In addition, when threshold/quantification cycle (Cq) values of NKILA gene expression increased, Cq values of BAX, CASP9, APAF1, and BCL-2 gene expression increased statistics significantly. The expression detection of all these genes, resulting from NKILA gene silencing, may provide guidance for epigenetic studies on EC apoptosis in atherosclerosis.

Dysregulated lipid metabolism and intervertebral disc degeneration: the important role of ox-LDL/LOX-1 in endplate chondrocyte senescence and calcification.

BACKGROUND: Lipid metabolism disorders are associated with degeneration of multiple tissues and organs, but the mechanism of crosstalk between lipid metabolism disorder and intervertebral disc degeneration (IDD) has not been fully elucidated. In this study we aim to investigate the regulatory mechanism of abnormal signal of lipid metabolism disorder on intervertebral disc endplate chondrocyte (EPC) senescence and calcification. METHODS: Human intervertebral disc cartilage endplate tissue, cell model and rat hyperlipemia model were performed in this study. Histology and immunohistochemistry were used to human EPC tissue detection. TMT-labelled quantitative proteomics was used to detect differential proteins, and MRI, micro-CT, safranin green staining and immunofluorescence were performed to observe the morphology and degeneration of rat tail intervertebral discs. Flow cytometry, senescence-associated ß-galactosidase staining, alizarin red staining, alkaline phosphatase staining, DCFH-DA fluorescent probe, and western blot were performed to detect the expression of EPC cell senescence, senescence-associated secretory phenotype, calcification-related proteins and the activation of cell senescence-related signaling pathways. RESULTS: Our study found that the highly expressed oxidized low-density lipoprotein (ox-LDL) and Lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) in human degenerative EPC was associated with hyperlipidemia (HLP). TMT-labelled quantitative proteomics revealed enriched pathways such as cell cycle regulation, endochondral bone morphogenesis and inflammation. The rat model revealed that HLP could induce ox-LDL, LOX-1, senescence and calcification markers high expression in EPC. Moreover, we demonstrated that ox-LDL-induced EPCs senescence and calcification were dependent on the LOX-1 receptor, and the ROS/P38-MAPK/NF-κB signaling pathway was implicated in the regulation of senescence induced by ox-LDL/LOX-1 in cell model. CONCLUSIONS: So our study revealed that ox-LDL/LOX-1-induced EPCs senescence and calcification through ROS/P38-MAPK/NF-κB signaling pathway, providing information on understanding the link between lipid metabolism disorders and IDD.

Regulatory factor X7 Represses Ox-LDL-Induced Proliferation and Migration of VSMCs via SIRT4-Mediated Inactivation of JAK2/STAT3 Pathway.

The regulatory factor X7 (RFX7) is a vital mediator in atherosclerosis. This study aims to discuss the effect and underlying mechanism of RFX7 on the regulation of oxidized low-density lipoprotein (ox-LDL) -induced proliferation and migration of vascular smooth muscle cells (VSMCs).Ox-LDL was used to construct atherosclerosis in vitro model. The mRNA and protein levels of RFX7 and Sirtuin 4 (SIRT4) were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot assays. The cellular functions were measured via 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT), EdU, flow cytometry, and wound healing assay assays. The interaction between RFX7 and SIRT4 promoter was validated using chromatin immunoprecipitation and dual-luciferase reporter assays.The stimulation with ox-LDL elevated the viability of VSMCs and decreased the mRNA and protein levels of RFX7 and SIRT4 in VSMCs in a dose-dependent manner. Functionally, RFX7 overexpression restrained the VSMC viability, proliferation, and migration induced by ox-LDL, but facilitated VSMC apoptosis. RFX7 elevated SIRT4 expression via binding to its promoter. Furthermore, overexpressing either SIRT4 or RFX7 inactivated JAK2/STAT3 signaling, causing a decrease in VSMC proliferation and migration and an increase in VSMC apoptosis when exposed to ox-LDL. The impact of RFX7 overexpression on JAK2/STAT3 signaling and cellular function following ox-LDL exposure was abrogated by SIRT4 silencing.The heightened RFX7 expression restrained the proliferation and migration of ox-LDL-stimulated VSMCs via SIRT4-mediated inactivation of JAK2/STAT3 pathway.

IL-1ß Induces LDL Transcytosis by a Novel Pathway Involving LDLR and Rab27a.

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-1ß (interleukin-1ß); this significantly reduced cardiovascular events. However, whether IL-1ß 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-1ß. To investigate transcytosis in vivo, we injected wild-type and knockout mice with IL-1ß and LDL to visualize acute LDL deposition in the aortic arch. RESULTS: Exposure to picomolar concentrations of IL-1ß 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-1ß 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-1ß 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-1ß, we identified Rab27a. Overexpression of Rab27a alone had no effect on basal transcytosis, but its knockdown prevented induction by IL-1ß. This was phenocopied by depletion of the Rab27a effector JFC1 (synaptotagmin-like protein 1). In vivo, IL-1ß increased LDL transcytosis in the aortic arch of wild-type but not Ldlr-/- or Rab27a-deficient mice. The JFC1 inhibitor nexinhib20 also blocked IL-1ß-induced LDL accumulation in the aorta. CONCLUSIONS: IL-1ß 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-1ß may contribute to the acceleration of early disease.

Rice bran active peptide (RBAP) inhibited macrophage differentiation to foam cell and atherosclerosis in mice via regulating cholesterol efflux.

BACKGROUND: Atherosclerosis is a long-lasting inflammatory condition affecting the walls of arteries, marked by the buildup of fats, plaque formation, and vascular remodeling. Recent findings highlight the significance of cholesterol removal pathways in influencing atherosclerosis, yet the connection between cholesterol removal and regulation of macrophage inflammation remains poorly understood. RBAP could serve as an anti-inflammatory agent; however, its role in atherosclerosis and the mechanism behind it are still not well understood. PURPOSE: The objective of this research is to explore how RBAP impacts cholesterol efflux, which is a considerable element in the advancement of atherosclerosis. METHODS: An atherosclerosis mouse model was established by using an ApoE KO strain mouse on a high-fat diet (HFD) to assess the effects of RBAP, conducted either orally or through injection. Additionally, in vitro experiments were conducted where the induction of THP-1 cells was conducted for the differentiation towards macrophages, and along with mouse RAW264.7 cells, were challenged with ox-LDL to evaluate the impact of RBAP. RESULTS: In this study, RBAP was found to reduce the production and downregulate TNF-α, IL-1ß, and IL-6 levels and inhibited the activation of the TLR4/MyD88/NF-κB signaling in atherosclerosis model mice, as well as in ox-LDL-challenged THP-1 cells and mouse RAW264.7 macrophages. RBAP's effectiveness also improved the enhancement of reverse cholesterol transport (RCT) and cholesterol removal to HDL and apoA1 by increasing the activity of genes related to cholesterol removal PPARγ/LXRα/ABCA1/ABCG1, both in ApoE-/- mice and in THP-1 cells and mouse RAW264.7 macrophages. Notably, RBAP exerted similar effects on atherosclerosis model mice and macrophages to those of TAK-242, an inhibitor of the TLR4 signaling. When RBAP and TAK-242 were applied simultaneously, the improvement was not enhanced compared with either RBAP or TAK-242 treatment alone. CONCLUSION: These findings suggest that RBAP, as a TLR4 inhibitor, has anti-atherosclerotic effects by improving inflammation and promoting cholesterol effection, indicating its therapeutic potential in intervening atherosclerosis.