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1.
Front Endocrinol (Lausanne) ; 15: 1398462, 2024.
Article in English | MEDLINE | ID: mdl-38957441

ABSTRACT

Background: Cannabidiol (CBD), a non-psychoactive phytocannabinoid of cannabis, is therapeutically used as an analgesic, anti-convulsant, anti-inflammatory, and anti-psychotic drug. There is a growing concern about the adverse side effects posed by CBD usage. Pregnane X receptor (PXR) is a nuclear receptor activated by a variety of dietary steroids, pharmaceutical agents, and environmental chemicals. In addition to the role in xenobiotic metabolism, the atherogenic and dyslipidemic effects of PXR have been revealed in animal models. CBD has a low affinity for cannabinoid receptors, thus it is important to elucidate the molecular mechanisms by which CBD activates cellular signaling and to assess the possible adverse impacts of CBD on pro-atherosclerotic events in cardiovascular system, such as dyslipidemia. Objective: Our study aims to explore the cellular and molecular mechanisms by which exposure to CBD activates human PXR and increases the risk of dyslipidemia. Methods: Both human hepatic and intestinal cells were used to test if CBD was a PXR agonist via cell-based transfection assay. The key residues within PXR's ligand-binding pocket that CBD interacted with were investigated using computational docking study together with site-directed mutagenesis assay. The C57BL/6 wildtype mice were orally fed CBD in the presence of PXR antagonist resveratrol (RES) to determine how CBD exposure could change the plasma lipid profiles in a PXR-dependent manner. Human intestinal cells were treated with CBD and/or RES to estimate the functions of CBD in cholesterol uptake. Results: CBD was a selective agonist of PXR with higher activities on human PXR than rodents PXRs and promoted the dissociation of human PXR from nuclear co-repressors. The key amino acid residues Met246, Ser247, Phe251, Phe288, Trp299, and Tyr306 within PXR's ligand binding pocket were identified to be necessary for the agonistic effects of CBD. Exposure to CBD increased the circulating total cholesterol levels in mice which was partially caused by the induced expression levels of the key intestinal PXR-regulated lipogenic genes. Mechanistically, CBD induced the gene expression of key intestinal cholesterol transporters, which led to the increased cholesterol uptake by intestinal cells. Conclusion: CBD was identified as a selective PXR agonist. Exposure to CBD activated PXR signaling and increased the atherogenic cholesterol levels in plasma, which partially resulted from the ascended cholesterol uptake by intestinal cells. Our study provides potential evidence for the future risk assessment of CBD on cardiovascular disease, such as dyslipidemia.


Subject(s)
Cannabidiol , Cholesterol , Mice, Inbred C57BL , Pregnane X Receptor , Pregnane X Receptor/metabolism , Animals , Humans , Mice , Cannabidiol/pharmacology , Cholesterol/metabolism , Male , Intestinal Mucosa/metabolism , Intestinal Mucosa/drug effects , Molecular Docking Simulation
2.
Sci Rep ; 14(1): 15592, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38971841

ABSTRACT

The production of cultured red blood cells (cRBC) for transfusion purposes requires large scale cultures and downstream processes to purify enucleated cRBC. The membrane composition, and cholesterol content in particular, are important during proliferation of (pro)erythroblasts and for cRBC quality. Therefore, we tested the requirement for cholesterol in the culture medium during expansion and differentiation of erythroid cultures with respect to proliferation, enucleation and purification by filtration. The low cholesterol level (22 µg/dl) in serum free medium was sufficient to expand (pro)erythroblast cultures. Addition of 2.0 or 5.0 mg/dL of free cholesterol at the start of differentiation induction inhibited enucleation compared to the default condition containing 3.3 mg/dl total cholesterol derived from the addition of Omniplasma to serum free medium. Addition of 5.0 mg/dl cholesterol at day 5 of differentiation did not affect the enucleation process but significantly increased recovery of enucleated cRBC following filtration over leukodepletion filters. The addition of cholesterol at day 5 increased the osmotic resistance of cRBC. In conclusion, cholesterol supplementation after the onset of enucleation improved the robustness of cRBC and increased the yield of enucleated cRBC in the purification process.


Subject(s)
Cholesterol , Culture Media , Erythrocytes , Cholesterol/metabolism , Humans , Erythrocytes/metabolism , Culture Media/chemistry , Cells, Cultured , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Cell Culture Techniques/methods , Erythroblasts/metabolism , Erythroblasts/cytology , Culture Media, Serum-Free
3.
Nat Commun ; 15(1): 5767, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38982045

ABSTRACT

Multiple myeloma (MM) is a hematologic malignancy characterized by uncontrolled proliferation of plasma cells in the bone marrow. MM patients with aggressive progression have poor survival, emphasizing the urgent need for identifying new therapeutic targets. Here, we show that the leukocyte immunoglobulin-like receptor B1 (LILRB1), a transmembrane receptor conducting negative immune response, is a top-ranked gene associated with poor prognosis in MM patients. LILRB1 deficiency inhibits MM progression in vivo by enhancing the ferroptosis of MM cells. Mechanistic studies reveal that LILRB1 forms a complex with the low-density lipoprotein receptor (LDLR) and LDLR adapter protein 1 (LDLRAP1) to facilitate LDL/cholesterol uptake. Loss of LILRB1 impairs cholesterol uptake but activates the de novo cholesterol synthesis pathway to maintain cellular cholesterol homeostasis, leading to the decrease of anti-ferroptotic metabolite squalene. Our study uncovers the function of LILRB1 in regulating cholesterol metabolism and protecting MM cells from ferroptosis, implicating LILRB1 as a promising therapeutic target for MM patients.


Subject(s)
Cholesterol , Ferroptosis , Homeostasis , Leukocyte Immunoglobulin-like Receptor B1 , Multiple Myeloma , Receptors, LDL , Humans , Multiple Myeloma/metabolism , Multiple Myeloma/pathology , Multiple Myeloma/genetics , Leukocyte Immunoglobulin-like Receptor B1/metabolism , Ferroptosis/genetics , Cholesterol/metabolism , Receptors, LDL/metabolism , Receptors, LDL/genetics , Animals , Cell Line, Tumor , Mice , Antigens, CD
4.
Methods Mol Biol ; 2816: 205-222, 2024.
Article in English | MEDLINE | ID: mdl-38977601

ABSTRACT

The role of lipid metabolic pathways in the pathophysiology of primary open-angle glaucoma (POAG) has been thoroughly elucidated, with pathways involved in lipid-related disorders such as hypercholesterolemia and hyperlipoprotein accumulation being of particular interest. The ABCA1/apoA-1 transduction pathway moderates reverse cholesterol transport (RCT), facilitating the transport of free cholesterol (FC) and phospholipids (PL) and preventing intracellular lipid aggregates in retinal ganglion cells (RGCs) due to excess FCs and PLs. A deficiency of ABCA1 transporters, and thus, dysregulation of the ABCA1/apoA-1 transduction pathway, may potentiate cellular lipid accumulation, which affects the structural and mechanical features of the cholesterol-rich RGC membranes. Atomic force microscopy (AFM) is a cutting-edge imaging technique suitable for imaging topographical surfaces of a biological specimen and determining its mechanical properties and structural features. The versatility and precision of this technique may prove beneficial in understanding the effects of ABCA1/apoA-1 pathway downregulation and decreased cholesterol efflux in RGCs and their membranes. In this protocol, ABCA1-/- RGC mouse models are prepared over the course of 3 days and are then compared with non-knockout ABCA1 RGC mouse models through AFM imaging of topographical surfaces to examine the difference in membrane dynamics of knockout vs. non-knockout models. Intracellular and extracellular levels of lipids are quantified through high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS).


Subject(s)
ATP Binding Cassette Transporter 1 , Apolipoprotein A-I , Lipidomics , Microscopy, Atomic Force , Signal Transduction , Microscopy, Atomic Force/methods , Animals , Mice , ATP Binding Cassette Transporter 1/metabolism , Apolipoprotein A-I/metabolism , Lipidomics/methods , Cholesterol/metabolism , Mice, Knockout , Lipid Metabolism
5.
Methods Mol Biol ; 2816: 253-263, 2024.
Article in English | MEDLINE | ID: mdl-38977604

ABSTRACT

Lipids are compounds involved in many biologic functions including cell structure, metabolism, energy storage and are involved in signaling. A prominent lipid in these functions is cholesterol. Cholesterol also plays a part in the signaling of melanocytes, which contain melanosomes. The maturation of these melanosomes happens during melanocyte growth. The deficit of melanogenesis or melanosome maturation is associated with ocular albinism in the eye. Aberrations of melanosome maturation are also associated with pigment dispersion syndrome. Albinism and pigment dispersion manifestations are systemic. Both melanogenesis and melanocyte maturation are affected by cholesterol metabolism. Cholesterol signaling is a part of many pathways in the body, and evaluating these signals can have implications in systemic disease processes of melanogenesis and melanosome maturation, like ocular albinism and pigment dispersion. Cholesterol is carried by lipoprotein particles. Low-density lipoprotein (LDL) is usually the transport vehicle for cholesterol to reach tissues and organelles. The LDL uptake on cells often sends out a cascade of internal signaling within the cells. We describe here LDL signaling related to lipase activity changes using enzymatic methods with a kit. We describe analyses of cholesterol esters and free cholesterol with liquid chromatography and gas chromatography with or in tandem with mass spectrometry (GC-MS and LC-MS/MS). These analyses will provide insight into melanosome maturation and melanogenesis. The methods described here are applicable to all melanocytes within the body of a model mammalian organism.


Subject(s)
Cholesterol , Iris , Melanocytes , Signal Transduction , Melanocytes/metabolism , Humans , Cholesterol/metabolism , Iris/metabolism , Lipoproteins/metabolism , Melanosomes/metabolism , Lipoproteins, LDL/metabolism , Tandem Mass Spectrometry/methods , Gas Chromatography-Mass Spectrometry/methods , Chromatography, Liquid/methods , Lipase/metabolism , Melanins/metabolism , Cholesterol Esters/metabolism
6.
Nat Commun ; 15(1): 5680, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38971819

ABSTRACT

Obesity shapes anti-tumor immunity through lipid metabolism; however, the mechanisms underlying how colorectal cancer (CRC) cells utilize lipids to suppress anti-tumor immunity remain unclear. Here, we show that tumor cell-intrinsic ATP6V0A1 drives exogenous cholesterol-induced immunosuppression in CRC. ATP6V0A1 facilitates cholesterol absorption in CRC cells through RAB guanine nucleotide exchange factor 1 (RABGEF1)-dependent endosome maturation, leading to cholesterol accumulation within the endoplasmic reticulum and elevated production of 24-hydroxycholesterol (24-OHC). ATP6V0A1-induced 24-OHC upregulates TGF-ß1 by activating the liver X receptor (LXR) signaling. Subsequently, the release of TGF-ß1 into the tumor microenvironment by CRC cells activates the SMAD3 pathway in memory CD8+ T cells, ultimately suppressing their anti-tumor activities. Moreover, we identify daclatasvir, a clinically used anti-hepatitis C virus (HCV) drug, as an ATP6V0A1 inhibitor that can effectively enhance the memory CD8+ T cell activity and suppress tumor growth in CRC. These findings shed light on the potential for ATP6V0A1-targeted immunotherapy in CRC.


Subject(s)
CD8-Positive T-Lymphocytes , Cholesterol , Colorectal Neoplasms , Signal Transduction , Transforming Growth Factor beta1 , Colorectal Neoplasms/immunology , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Humans , Animals , Cholesterol/metabolism , Mice , Cell Line, Tumor , Transforming Growth Factor beta1/metabolism , Immunologic Memory , Vacuolar Proton-Translocating ATPases/metabolism , Tumor Microenvironment/immunology , Liver X Receptors/metabolism , Hydroxycholesterols/metabolism , Hydroxycholesterols/pharmacology , Pyrrolidines/pharmacology , Smad3 Protein/metabolism , Mice, Inbred C57BL , Carbamates/pharmacology
7.
Nat Commun ; 15(1): 5659, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38969646

ABSTRACT

Fully targeted mRNA therapeutics necessitate simultaneous organ-specific accumulation and effective translation. Despite some progress, delivery systems are still unable to fully achieve this. Here, we reformulate lipid nanoparticles (LNPs) through adjustments in lipid material structures and compositions to systematically achieve the pulmonary and hepatic (respectively) targeted mRNA distribution and expression. A combinatorial library of degradable-core based ionizable cationic lipids is designed, following by optimisation of LNP compositions. Contrary to current LNP paradigms, our findings demonstrate that cholesterol and phospholipid are dispensable for LNP functionality. Specifically, cholesterol-removal addresses the persistent challenge of preventing nanoparticle accumulation in hepatic tissues. By modulating and simplifying intrinsic LNP components, concurrent mRNA accumulation and translation is achieved in the lung and liver, respectively. This targeting strategy is applicable to existing LNP systems with potential to expand the progress of precise mRNA therapy for diverse diseases.


Subject(s)
Lipids , Liver , Lung , Nanoparticles , RNA, Messenger , RNA, Messenger/metabolism , RNA, Messenger/genetics , Nanoparticles/chemistry , Animals , Liver/metabolism , Lung/metabolism , Lipids/chemistry , Humans , Mice , Cholesterol/metabolism , Cholesterol/chemistry , Protein Biosynthesis , Mice, Inbred C57BL , Phospholipids/chemistry , Phospholipids/metabolism , Liposomes
8.
Medicine (Baltimore) ; 103(27): e38754, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38968507

ABSTRACT

The current first-line treatment for atherosclerotic cardiovascular disease (ASCVD) involves the reduction of a patient's low-density lipoprotein cholesterol (LDL-C) levels through the use of lipid-lowering drugs. However, even when other risk factors such as hypertension and diabetes are effectively managed, there remains a residual cardiovascular risk in these patients despite achieving target LDL-C levels with statins and new lipid-lowering medications. This risk was previously believed to be associated with lipid components other than LDL, such as triglycerides. However, recent studies have unveiled the crucial role of remnant cholesterol (RC) in atherosclerosis, not just triglycerides. The metabolized product of triglyceride-rich lipoproteins is referred to as triglyceride-rich remnant lipoprotein particles, and its cholesterol component is known as RC. Numerous pieces of evidence from epidemiological investigations and genetic studies demonstrate that RC plays a significant role in predicting the incidence of ASCVD. As a novel marker for atherosclerosis prediction, when LDL-C is appropriately controlled, RC should be prioritized for attention and intervention among individuals at high risk of ASCVD. Therefore, reducing RC levels through the use of various lipid-lowering drugs may yield long-term benefits. Nevertheless, routine testing of RC in clinical practice remains controversial, necessitating further research on the treatment of elevated RC levels to evaluate the advantages of reducing RC in patients at high risk of ASCVD.


Subject(s)
Atherosclerosis , Cholesterol , Humans , Atherosclerosis/blood , Cholesterol/blood , Cholesterol/metabolism , Triglycerides/blood , Risk Factors , Biomarkers/blood , Cholesterol, LDL/blood , Lipoproteins/blood , Lipoproteins/metabolism , Cardiovascular Diseases/blood , Cardiovascular Diseases/etiology , Cardiovascular Diseases/prevention & control
9.
Cell Mol Life Sci ; 81(1): 289, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38970696

ABSTRACT

Congenital human cytomegalovirus (HCMV) infection is a major cause of abnormalities and disorders in the central nervous system (CNS) and/or the peripheral nervous system (PNS). However, the complete pathogenesis of neural differentiation disorders caused by HCMV infection remains to be fully elucidated. Stem cells from human exfoliated deciduous teeth (SHEDs) are mesenchymal stem cells (MSCs) with a high proliferation and neurogenic differentiation capacity. Since SHEDs originate from the neural crest of the early embryonic ectoderm, SHEDs were hypothesized to serve as a promising cell line for investigating the pathogenesis of neural differentiation disorders in the PNS caused by congenital HCMV infection. In this work, SHEDs were demonstrated to be fully permissive to HCMV infection and the virus was able to complete its life cycle in SHEDs. Under neurogenic inductive conditions, HCMV infection of SHEDs caused an abnormal neural morphology. The expression of stem/neural cell markers was also disturbed by HCMV infection. The impairment of neural differentiation was mainly due to a reduction of intracellular cholesterol levels caused by HCMV infection. Sterol regulatory element binding protein-2 (SREBP2) is a critical transcription regulator that guides cholesterol synthesis. HCMV infection was shown to hinder the migration of SREBP2 into nucleus and resulted in perinuclear aggregations of SREBP2 during neural differentiation. Our findings provide new insights into the prevention and treatment of nervous system diseases caused by congenital HCMV infection.


Subject(s)
Cell Differentiation , Cholesterol , Cytomegalovirus Infections , Cytomegalovirus , Mesenchymal Stem Cells , Sterol Regulatory Element Binding Protein 2 , Humans , Cholesterol/metabolism , Cholesterol/biosynthesis , Cytomegalovirus Infections/virology , Cytomegalovirus Infections/metabolism , Sterol Regulatory Element Binding Protein 2/metabolism , Sterol Regulatory Element Binding Protein 2/genetics , Cytomegalovirus/physiology , Cytomegalovirus/metabolism , Mesenchymal Stem Cells/metabolism , Mesenchymal Stem Cells/virology , Mesenchymal Stem Cells/cytology , Cells, Cultured , Tooth, Deciduous/virology , Tooth, Deciduous/cytology , Tooth, Deciduous/metabolism , Neurons/metabolism , Neurons/virology , Neurogenesis
10.
Cell Mol Life Sci ; 81(1): 287, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38970705

ABSTRACT

Lung type 2 pneumocytes (T2Ps) and alveolar macrophages (AMs) play crucial roles in the synthesis, recycling and catabolism of surfactant material, a lipid/protein fluid essential for respiratory function. The liver X receptors (LXR), LXRα and LXRß, are transcription factors important for lipid metabolism and inflammation. While LXR activation exerts anti-inflammatory actions in lung injury caused by lipopolysaccharide (LPS) and other inflammatory stimuli, the full extent of the endogenous LXR transcriptional activity in pulmonary homeostasis is incompletely understood. Here, using mice lacking LXRα and LXRß as experimental models, we describe how the loss of LXRs causes pulmonary lipidosis, pulmonary congestion, fibrosis and chronic inflammation due to defective de novo synthesis and recycling of surfactant material by T2Ps and defective phagocytosis and degradation of excess surfactant by AMs. LXR-deficient T2Ps display aberrant lamellar bodies and decreased expression of genes encoding for surfactant proteins and enzymes involved in cholesterol, fatty acids, and phospholipid metabolism. Moreover, LXR-deficient lungs accumulate foamy AMs with aberrant expression of cholesterol and phospholipid metabolism genes. Using a house dust mite aeroallergen-induced mouse model of asthma, we show that LXR-deficient mice exhibit a more pronounced airway reactivity to a methacholine challenge and greater pulmonary infiltration, indicating an altered physiology of LXR-deficient lungs. Moreover, pretreatment with LXR agonists ameliorated the airway reactivity in WT mice sensitized to house dust mite extracts, confirming that LXR plays an important role in lung physiology and suggesting that agonist pharmacology could be used to treat inflammatory lung diseases.


Subject(s)
Homeostasis , Liver X Receptors , Macrophages, Alveolar , Pneumonia , Pulmonary Surfactants , Signal Transduction , Animals , Liver X Receptors/metabolism , Liver X Receptors/genetics , Pulmonary Surfactants/metabolism , Mice , Pneumonia/metabolism , Pneumonia/pathology , Macrophages, Alveolar/metabolism , Mice, Inbred C57BL , Mice, Knockout , Lung/metabolism , Lung/pathology , Alveolar Epithelial Cells/metabolism , Asthma/metabolism , Asthma/pathology , Asthma/genetics , Cholesterol/metabolism , Lipid Metabolism , Phagocytosis
11.
Methods Enzymol ; 700: 217-234, 2024.
Article in English | MEDLINE | ID: mdl-38971601

ABSTRACT

Sphingomyelin is postulated to form clusters with glycosphingolipids, cholesterol and other sphingomyelin molecules in biomembranes through hydrophobic interaction and hydrogen bonds. These clusters form submicron size lipid domains. Proteins that selectively binds sphingomyelin and/or cholesterol are useful to visualize the lipid domains. Due to their small size, visualization of lipid domains requires advanced microscopy techniques in addition to lipid binding proteins. This Chapter describes the method to characterize plasma membrane sphingomyelin-rich and cholesterol-rich lipid domains by quantitative microscopy. This Chapter also compares different permeabilization methods to visualize intracellular lipid domains.


Subject(s)
Cholesterol , Sphingomyelins , Sphingomyelins/chemistry , Sphingomyelins/metabolism , Cholesterol/chemistry , Cholesterol/metabolism , Humans , Animals , Membrane Microdomains/metabolism , Membrane Microdomains/chemistry , Microscopy/methods , Carrier Proteins/chemistry , Carrier Proteins/metabolism , Cell Membrane/metabolism , Cell Membrane/chemistry
12.
Methods Enzymol ; 700: 275-294, 2024.
Article in English | MEDLINE | ID: mdl-38971603

ABSTRACT

Synthetic model membranes are important tools to elucidate lipid domain and protein interactions due to predefined lipid compositions and characterizable biophysical properties. Here, we introduce a model membrane with multiple lipid bilayers (multi-bilayers) stacked on a mica substrate that is prepared through a spin-coating technique. The spin-coated multi-bilayers are useful in the study of phase separated membranes with a high cholesterol content, mobile lipids, microscopic and reversible phase separation, and easy conjugation with proteins, which make them a good model to study interactions between proteins and membrane domains.


Subject(s)
Lipid Bilayers , Lipid Bilayers/chemistry , Lipid Bilayers/metabolism , Membrane Proteins/chemistry , Membrane Proteins/metabolism , Cholesterol/chemistry , Cholesterol/metabolism , Aluminum Silicates/chemistry , Membrane Microdomains/chemistry , Membrane Microdomains/metabolism , Protein Binding
13.
Nat Commun ; 15(1): 5732, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38977690

ABSTRACT

Site-one protease (S1P) conducts the first of two cleavage events in the Golgi to activate Sterol regulatory element binding proteins (SREBPs) and upregulate lipogenic transcription. S1P is also required for a wide array of additional signaling pathways. A zymogen serine protease, S1P matures through autoproteolysis of two pro-domains, with one cleavage event in the endoplasmic reticulum (ER) and the other in the Golgi. We recently identified the SREBP regulating gene, (SPRING), which enhances S1P maturation and is necessary for SREBP signaling. Here, we report the cryo-EM structures of S1P and S1P-SPRING at sub-2.5 Å resolution. SPRING activates S1P by dislodging its inhibitory pro-domain and stabilizing intra-domain contacts. Functionally, SPRING licenses S1P to cleave its cognate substrate, SREBP2. Our findings reveal an activation mechanism for S1P and provide insights into how spatial control of S1P activity underpins cholesterol homeostasis.


Subject(s)
Protein Domains , Sterol Regulatory Element Binding Protein 2 , Sterol Regulatory Element Binding Protein 2/metabolism , Sterol Regulatory Element Binding Protein 2/genetics , Humans , Serine Endopeptidases/metabolism , Serine Endopeptidases/chemistry , Serine Endopeptidases/genetics , Endoplasmic Reticulum/metabolism , Cryoelectron Microscopy , Golgi Apparatus/metabolism , Proprotein Convertases/metabolism , Proprotein Convertases/genetics , Cholesterol/metabolism , Animals , HEK293 Cells , Signal Transduction
14.
Nutrients ; 16(13)2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38999750

ABSTRACT

(1) Background: Recently, academic studies are demonstrating that the cholesterol-lowering effects of pectin oligosaccharides (POSs) are correlated to intestinal flora. However, the mechanisms of POS on cholesterol metabolisms are limited, and the observations of intestinal flora are lacking integrative analyses. (2) Aim and methods: To reveal the regulatory mechanisms of POS on cholesterol metabolism via an integrative analysis of the gut microbiota, the changes in gut microbiota structure and metabolite composition after POS addition were investigated using Illumina MiSeq sequencing and non-targeted metabolomics through in vitro gut microbiota fermentation. (3) Results: The composition of fecal gut flora was adjusted positively by POS. POS increased the abundances of the cholesterol-related bacterial groups Bacteroidetes, Bifidobacterium and Lactobacillus, while it decreased conditional pathogenic Escherichia coli and Enterococcus, showing good prebiotic activities. POS changed the composition of gut microbiota fermentation metabolites (P24), causing significant changes in 221 species of fermentation metabolites in a non-targeted metabolomics analysis and promoting the production of short-chain fatty acids. The abundances of four types of cholesterol metabolism-related metabolites (adenosine monophosphate, cyclic adenosine monophosphate, guanosine and butyrate) were significantly higher in the P24 group than those in the control group without POS addition. (4) Conclusion: The abovementioned results may explain the hypocholesterolemic effects of POS and promotion effects on cholesterol efflux of P24. These findings indicated that the potential regulatory mechanisms of citrus POS on cholesterol metabolism are modulated by cholesterol-related gut microbiota and specific metabolites.


Subject(s)
Cholesterol , Feces , Fermentation , Gastrointestinal Microbiome , Oligosaccharides , Pectins , Gastrointestinal Microbiome/drug effects , Gastrointestinal Microbiome/physiology , Pectins/pharmacology , Pectins/metabolism , Cholesterol/metabolism , Oligosaccharides/pharmacology , Feces/microbiology , Humans , Prebiotics , Male , Metabolomics , Fatty Acids, Volatile/metabolism , Bifidobacterium/metabolism , Bifidobacterium/drug effects , Female , Bacteria/metabolism , Bacteria/drug effects , Bacteria/classification , Citrus
15.
Anal Chem ; 96(28): 11463-11471, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-38962829

ABSTRACT

In this work, we reported a cholesterol oxidase (Chox)-loaded platinum (Pt) nanozyme with the collaborative cascade nanoreactor for the construction of nanozyme-enzyme-linked immunosorbent assay (N-ELSA) models to realize high-throughput rapid evaluation of cancer markers. Considering the high specific surface area and manipulable surface sites, ZIF-8 was used as a substrate for natural enzyme and nanozyme loading. The constructed ZIF-8-Pt nanozyme platform exhibited efficient enzyme-like catalytic efficiency with a standard corrected activity of 60.59 U mg-1, which was 12 times higher than that of the ZIF-8 precursor, and highly efficient photothermal conversion efficiency (∼35.49%). In N-ELISA testing, developed multienzyme photothermal probes were immobilized in microplates based on antigen-antibody-specific reactions. Cholesterol was reacted in a cascade to reactive oxygen radicals, which attacked 3,3',5,5'-tetramethylbenzidine, causing it to oxidize and color change, thus exhibiting highly enhanced efficient photothermal properties. Systematic temperature evaluations were performed by a hand-held microelectromechanical system thermal imager under the excitation of an 808 nm surface light source to determine the cancer antigen 15-3 (CA15-3) profiles in the samples. Encouragingly, the temperature signal from the microwells increased with increasing CA15-3, with a linear range of 2 mU mL-1 to 100 U mL-1, considering it to be the sensor with the widest working range for visualization and portability available. This work provides new horizons for the development of efficient multienzyme portable colorimetric-photothermal platforms to help advance the community-based process of early cancer detection.


Subject(s)
Cholesterol Oxidase , Platinum , Humans , Platinum/chemistry , Cholesterol Oxidase/chemistry , Cholesterol Oxidase/metabolism , Enzyme-Linked Immunosorbent Assay , Biomarkers, Tumor/metabolism , Biomarkers, Tumor/analysis , Benzidines/chemistry , Cholesterol/chemistry , Cholesterol/metabolism , Cholesterol/analysis , High-Throughput Screening Assays , Zeolites/chemistry
16.
Nat Commun ; 15(1): 5851, 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38992029

ABSTRACT

Tumor cells reprogram their metabolism to produce specialized metabolites that both fuel their own growth and license tumor immune evasion. However, the relationships between these functions remain poorly understood. Here, we report CRISPR screens in a mouse model of colo-rectal cancer (CRC) that implicates the dual specificity phosphatase 18 (DUSP18) in the establishment of tumor-directed immune evasion. Dusp18 inhibition reduces CRC growth rates, which correlate with high levels of CD8+ T cell activation. Mechanistically, DUSP18 dephosphorylates and stabilizes the USF1 bHLH-ZIP transcription factor. In turn, USF1 induces the SREBF2 gene, which allows cells to accumulate the cholesterol biosynthesis intermediate lanosterol and release it into the tumor microenvironment (TME). There, lanosterol uptake by CD8+ T cells suppresses the mevalonate pathway and reduces KRAS protein prenylation and function, which in turn inhibits their activation and establishes a molecular basis for tumor cell immune escape. Finally, the combination of an anti-PD-1 antibody and Lumacaftor, an FDA-approved small molecule inhibitor of DUSP18, inhibits CRC growth in mice and synergistically enhances anti-tumor immunity. Collectively, our findings support the idea that a combination of immune checkpoint and metabolic blockade represents a rationally-designed, mechanistically-based and potential therapy for CRC.


Subject(s)
CD8-Positive T-Lymphocytes , Cholesterol , Colorectal Neoplasms , Dual-Specificity Phosphatases , Animals , Colorectal Neoplasms/immunology , Colorectal Neoplasms/genetics , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/pathology , Mice , Humans , Cholesterol/biosynthesis , Cholesterol/metabolism , Dual-Specificity Phosphatases/genetics , Dual-Specificity Phosphatases/metabolism , Dual-Specificity Phosphatases/antagonists & inhibitors , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/drug effects , Cell Line, Tumor , Tumor Microenvironment/immunology , Tumor Microenvironment/drug effects , Mitogen-Activated Protein Kinase Phosphatases/genetics , Mitogen-Activated Protein Kinase Phosphatases/metabolism , Tumor Escape/drug effects , Tumor Escape/genetics , Female
17.
PeerJ ; 12: e17749, 2024.
Article in English | MEDLINE | ID: mdl-39011373

ABSTRACT

Triple negative breast cancer (TNBC) as the most aggressive molecular subtype of breast cancer is characterized by high cancer cell proliferation and poor patient prognosis. Abnormal lipid metabolism contributes to the malignant process of cancers. Study observed significantly enhanced cholesterol biosynthesis in TNBC. However, the mechanisms underlying the abnormal increase of cholesterol biosynthesis in TNBC are still unclear. Hence, we identified a member of the serine/threonine protein kinase family PKMYT1 as a key driver of cholesterol synthesis in TNBC cells. Aberrantly high-expressed PKMYT1 in TNBC was indicative of unfavorable prognostic outcomes. In addition, PKMYT1 promoted sterol regulatory element-binding protein 2 (SREBP2)-mediated expression of enzymes related to cholesterol biosynthesis through activating the TNF/ TNF receptor-associated factor 1 (TRAF1)/AKT pathway. Notably, downregulation of PKMYT1 significantly inhibited the feedback upregulation of statin-mediated cholesterol biosynthesis, whereas knockdown of PKMYT1 promoted the drug sensitivity of atorvastatin in TNBC cells. Overall, our study revealed a novel function of PKMYT1 in TNBC cholesterol biosynthesis, providing a new target for targeting tumor metabolic reprogramming in the cancer.


Subject(s)
Atorvastatin , Cholesterol , Triple Negative Breast Neoplasms , Humans , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/genetics , Triple Negative Breast Neoplasms/pathology , Triple Negative Breast Neoplasms/metabolism , Atorvastatin/pharmacology , Atorvastatin/therapeutic use , Cholesterol/biosynthesis , Cholesterol/metabolism , Female , Cell Line, Tumor , Gene Knockdown Techniques , Gene Expression Regulation, Neoplastic/drug effects , Drug Resistance, Neoplasm/genetics , Drug Resistance, Neoplasm/drug effects , Sterol Regulatory Element Binding Protein 2/metabolism , Sterol Regulatory Element Binding Protein 2/genetics , Cell Proliferation/drug effects , Membrane Proteins , Protein-Tyrosine Kinases , Protein Serine-Threonine Kinases
18.
Int J Mol Sci ; 25(13)2024 Jun 28.
Article in English | MEDLINE | ID: mdl-39000217

ABSTRACT

Peroxisome proliferator-activated receptors (PPARs) may play an important role in the pathomechanism/pathogenesis of Alzheimer's disease (AD) and several other neurological/neuropsychiatric disorders. AD leads to progressive alterations in the redox state, ion homeostasis, lipids, and protein metabolism. Significant alterations in molecular processes and the functioning of several signaling pathways result in the degeneration and death of synapses and neuronal cells, leading to the most severe dementia. Peroxisome proliferator-activated receptor alpha (PPAR-α) is among the processes affected by AD; it regulates the transcription of genes related to the metabolism of cholesterol, fatty acids, other lipids and neurotransmission, mitochondria biogenesis, and function. PPAR-α is involved in the cholesterol transport to mitochondria, the substrate for neurosteroid biosynthesis. PPAR-α-coding enzymes, such as sulfotransferases, which are responsible for neurosteroid sulfation. The relation between PPAR-α and cholesterol/neurosteroids may have a significant impact on the course and progression of neurodegeneration/neuroprotection processes. Unfortunately, despite many years of intensive studies, the pathogenesis of AD is unknown and therapy for AD and other neurodegenerative diseases is symptomatic, presenting a significant goal and challenge today. This review presents recent achievements in therapeutic approaches for AD, which are targeting PPAR-α and its relation to cholesterol and neurosteroids in AD and neuropsychiatric disorders.


Subject(s)
Alzheimer Disease , Neurosteroids , PPAR alpha , Humans , Alzheimer Disease/metabolism , Alzheimer Disease/drug therapy , PPAR alpha/metabolism , Neurosteroids/metabolism , Animals , Mental Disorders/metabolism , Mental Disorders/drug therapy , Cholesterol/metabolism , Molecular Targeted Therapy , Mitochondria/metabolism
19.
J Exp Clin Cancer Res ; 43(1): 185, 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38965575

ABSTRACT

BACKGROUND: Metastasis is the leading cause of mortality in patients with colorectal cancer (CRC) and angiogenesis is a crucial factor in tumor invasion and metastasis. Long noncoding RNAs (lncRNAs) play regulatory functions in various biological processes in tumor cells, however, the roles of lncRNAs in CRC-associated angiogenesis remain to be elucidated in CRC, as do the underlying mechanisms. METHODS: We used bioinformatics to screen differentially expressed lncRNAs from TCGA database. LOC101928222 expression was assessed by qRT-PCR. The impact of LOC101928222 in CRC tumor development was assessed both in vitro and in vivo. The regulatory mechanisms of LOC101928222 in CRC were investigated by cellular fractionation, RNA-sequencing, mass spectrometric, RNA pull-down, RNA immunoprecipitation, RNA stability, and gene-specific m6A assays. RESULTS: LOC101928222 expression was upregulated in CRC and was correlated with a worse outcome. Moreover, LOC101928222 was shown to promote migration, invasion, and angiogenesis in CRC. Mechanistically, LOC101928222 synergized with IGF2BP1 to stabilize HMGCS2 mRNA through an m6A-dependent pathway, leading to increased cholesterol synthesis and, ultimately, the promotion of CRC development. CONCLUSIONS: In summary, these findings demonstrate a novel, LOC101928222-based mechanism involved in the regulation of cholesterol synthesis and the metastatic potential of CRC. The LOC101928222-HMGCS2-cholesterol synthesis pathway may be an effective target for diagnosing and managing CRC metastasis.


Subject(s)
Cholesterol , Colorectal Neoplasms , Neovascularization, Pathologic , RNA, Long Noncoding , RNA, Messenger , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Colorectal Neoplasms/metabolism , Humans , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Neovascularization, Pathologic/genetics , Neovascularization, Pathologic/metabolism , Neovascularization, Pathologic/pathology , Mice , Cholesterol/metabolism , Animals , RNA, Messenger/genetics , RNA, Messenger/metabolism , Hydroxymethylglutaryl-CoA Synthase/genetics , Hydroxymethylglutaryl-CoA Synthase/metabolism , Cell Line, Tumor , Gene Expression Regulation, Neoplastic , Male , Female , Angiogenesis
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