RESUMEN
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. VldlrhighHSCs show higher erythroid potential, which is enhanced after acute anemia induction. VldlrhighHSCs 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.
Asunto(s)
Anemia , Apolipoproteínas E , Diferenciación Celular , Células Madre Hematopoyéticas , Lipoproteínas , Animales , Anemia/metabolismo , Anemia/genética , Células Madre Hematopoyéticas/metabolismo , Ratones , Apolipoproteínas E/metabolismo , Apolipoproteínas E/genética , Lipoproteínas/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de LDL/metabolismo , Receptores de LDL/genética , Masculino , Cromatina/metabolismo , Eritropoyesis/genética , Células Eritroides/metabolismoRESUMEN
Helicobacter pylori is a bacterial pathogen that colonizes the human stomach, where it can cause a variety of diseases. H. pylori uses a cluster of sheathed flagella for motility, which is required for host colonization in animal models. The flagellar sheath is continuous with the outer membrane and is found in most Helicobacter species identified to date. HP0018 is a predicted lipoprotein of unknown function that is conserved in Helicobacter species that have flagellar sheaths but is absent in Helicobacter species that have sheath-less flagella. Deletion of hp0018 in H. pylori B128 resulted in the formation of long chains of outer membrane vesicles, which were most evident in an aflagellated variant of the Δhp0018 mutant that had a frameshift mutation in fliP. Flagellated cells of the Δhp0018 mutant possessed what appeared to be a normal flagellar sheath, suggesting that HP0018 is not required for sheath formation. Cells of the Δhp0018 mutant were also less helical in shape compared to wild-type cells. A HP0018-superfolder green fluorescent fusion protein expressed in the H. pylori Δhp0018 mutant formed fluorescent foci at the cell poles and lateral sites. Co-immunoprecipitation assays with HP0018 identified two enzymes involved in the modification of the cell wall peptidoglycan, AmiA and MltD, as potential HP0018 interaction partners. HP0018 may modulate the activity of AmiA or MltD, and in the absence of HP0018, the unregulated activity of these enzymes may alter the peptidoglycan layer in a manner that results in an altered cell shape and hypervesiculation.
Asunto(s)
Flagelos , Helicobacter pylori , Helicobacter pylori/genética , Helicobacter pylori/metabolismo , Helicobacter pylori/fisiología , Flagelos/metabolismo , Membrana Celular/metabolismo , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Humanos , Lipoproteínas/metabolismo , Lipoproteínas/genéticaRESUMEN
Curved cell shapes are widespread among bacteria and important for cellular motility, virulence and fitness. However, the underlying morphogenetic mechanisms are still incompletely understood. Here, we identify an outer-membrane protein complex that promotes cell curvature in the photosynthetic species Rhodospirillum rubrum. We show that the R. rubrum porins Por39 and Por41 form a helical ribbon-like structure at the outer curve of the cell that recruits the peptidoglycan-binding lipoprotein PapS, with PapS inactivation, porin delocalization or disruption of the porin-PapS interface resulting in cell straightening. We further demonstrate that porin-PapS assemblies act as molecular cages that entrap the cell elongation machinery, thus biasing cell growth towards the outer curve. These findings reveal a mechanistically distinct morphogenetic module mediating bacterial cell shape. Moreover, they uncover an unprecedented role of outer-membrane protein patterning in the spatial control of intracellular processes, adding an important facet to the repertoire of regulatory mechanisms in bacterial cell biology.
Asunto(s)
Lipoproteínas , Porinas , Rhodospirillum rubrum , Porinas/metabolismo , Porinas/genética , Rhodospirillum rubrum/metabolismo , Lipoproteínas/metabolismo , Proteínas de la Membrana Bacteriana Externa/metabolismo , Proteínas de la Membrana Bacteriana Externa/genéticaRESUMEN
The survival and proliferation of pathogenic Leptospira within a host are complex phenomena that require careful consideration. The ErpY-like lipoprotein, found on the outer membrane surface of Leptospira, plays a crucial role in enhancing the bacterium's pathogenicity. The rErpY-like protein, in its recombinant form, contributes significantly to spirochete virulence by interacting with various host factors, including host complement regulators. This interaction facilitates the bacterium's evasion of the host complement system, thereby augmenting its overall pathogenicity. The rErpY-like protein exhibits a robust binding affinity to soluble fibrinogen, a vital component of the host coagulation system. In this study, we demonstrate that the rErpY-like protein intervenes in the clotting process of the platelet-poor citrated plasma of bovines and humans in a concentration-dependent manner. It significantly reduces clot density, alters the viscoelastic properties of the clot, and diminishes the average clotting rate in plasma. Furthermore, the ErpY-like protein inhibits thrombin-catalyzed fibrin formation in a dose-dependent manner and exhibits saturable binding to thrombin, suggesting its significant role in leptospiral infection. These findings provide compelling evidence for the anticoagulant effect of the ErpY-like lipoprotein and its significant role in leptospiral infection.
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Coagulación Sanguínea , Fibrinógeno , Trombina , Fibrinógeno/metabolismo , Fibrinógeno/química , Humanos , Trombina/metabolismo , Animales , Bovinos , Unión Proteica , Leptospira/metabolismo , Leptospirosis/microbiología , Proteínas de la Membrana Bacteriana Externa/metabolismo , Lipoproteínas/metabolismo , Interacciones Huésped-PatógenoRESUMEN
Non-alcoholic fatty liver disease (NAFLD) is a progressive liver disease characterized by the build-up of fat in the liver of individuals in the absence of alcohol consumption. This condition has become a burden in modern societies aggravated by the lack of appropriate predictive biomarkers (other than liver biopsy). To better understand this disease and to find appropriate biomarkers, a new technology has emerged in the last two decades with the ability to explore the unmapped role of lipids in this disease: lipidomics. This technology, based on the combination of chromatography and mass spectrometry, has been extensively used to explore the lipid metabolism of NAFLD. In this review, we aim to summarize the knowledge gained through lipidomics assays exploring tissues, plasma, and lipoproteins from individuals with NAFLD. Our goal is to identify common features and active pathways that could facilitate the finding of a reliable biomarker from this field. The most frequent observation was a variable decrease (1-9%) in polyunsaturated fatty acids in phospholipids and non-esterified fatty acids in NAFLD patients, both in plasma and liver. Additionally, a reduction in phosphatidylcholines is a common feature in the liver. Due to the scarcity of studies, further research is needed to properly detect lipoprotein, plasma, and tissue lipid signatures of NAFLD etiologies, and NAFLD subtypes, and to define the relevance of this technology in disease management strategies in the push toward personalized medicine.
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Biomarcadores , Lipidómica , Enfermedad del Hígado Graso no Alcohólico , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/sangre , Enfermedad del Hígado Graso no Alcohólico/diagnóstico , Humanos , Biomarcadores/sangre , Lipidómica/métodos , Lipoproteínas/metabolismo , Lipoproteínas/sangre , Metabolismo de los Lípidos , Hígado/metabolismo , AnimalesRESUMEN
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.
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Aterosclerosis , Lipoproteínas HDL , Lipoproteínas LDL , Macrófagos , Conceptos Matemáticos , Fenotipo , Humanos , Macrófagos/metabolismo , Macrófagos/patología , Aterosclerosis/patología , Aterosclerosis/metabolismo , Aterosclerosis/sangre , Lipoproteínas LDL/metabolismo , Lipoproteínas LDL/sangre , Lipoproteínas HDL/sangre , Lipoproteínas HDL/metabolismo , Modelos Cardiovasculares , Metabolismo de los Lípidos , Lipoproteínas/metabolismo , Lipoproteínas/sangre , Simulación por ComputadorRESUMEN
Membrane lipoproteins serve as primary pro-inflammatory virulence factors in Mycoplasma genitalium. Membrane lipoproteins primarily induce inflammatory responses by activating Toll-like Receptor 2 (TLR2); however, the role of the metabolic status of urethral epithelial cells in inflammatory response remains unclear. In this study, we found that treatment of uroepithelial cell lines with M. genitalium membrane lipoprotein induced metabolic reprogramming, characterized by increased aerobic glycolysis, decreased oxidative phosphorylation, and increased production of the metabolic intermediates acetyl-CoA and malonyl-CoA. The metabolic shift induced by membrane lipoproteins is reversible upon blocking MyD88 and TRAM. Malonyl-CoA induces malonylation of glyceraldehyde 3-phosphate dehydrogenase (GAPDH), and malonylated GAPDH could dissociate from the 3' untranslated region of TNF-α and IFN-γ mRNA. This dissociation greatly reduces the inhibitory effect on the translation of TNF-α and IFN-γ mRNA, thus achieving fine-tuning control over cytokine secretion. These findings suggest that GAPDH malonylation following M. genitalium infection is an important inflammatory signal that plays a crucial role in urogenital inflammatory diseases.
Asunto(s)
Citocinas , Células Epiteliales , Interferón gamma , Mycoplasma genitalium , Factor de Necrosis Tumoral alfa , Mycoplasma genitalium/metabolismo , Mycoplasma genitalium/genética , Células Epiteliales/metabolismo , Células Epiteliales/microbiología , Humanos , Citocinas/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Interferón gamma/metabolismo , Línea Celular , Lipoproteínas/metabolismo , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Gliceraldehído-3-Fosfato Deshidrogenasas/genética , Uretra/microbiología , Uretra/metabolismo , Infecciones por Mycoplasma/metabolismo , Infecciones por Mycoplasma/microbiología , Factores de Virulencia/metabolismo , Factor 88 de Diferenciación Mieloide/metabolismo , Glucólisis , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 2/genéticaRESUMEN
PURPOSE OF REVIEW: This review examines the evolving role of the fat-inducing transcript 2 (FIT2) protein in lipid droplet (LD) biology and its broader implications in cellular physiology and disease. With recent advancements in understanding FIT2 function across various model systems, this review provides a timely synthesis of its mechanisms and physiological significance. RECENT FINDINGS: FIT2, an endoplasmic reticulum (ER)-resident protein, has been established as a critical regulator of LD formation in diverse organisms, from yeast to mammals. It facilitates LD biogenesis by sequestering diacylglycerol (DAG) and potentially influencing ER membrane dynamics. Beyond its role in lipid metabolism, FIT2 intersects with the ER-associated degradation (ERAD), is critical for protein homeostasis, and is linked to the unfolded protein response (UPR). Dysregulation of FIT2 has also been linked to metabolic disorders such as insulin resistance and lipodystrophy, highlighting its clinical relevance. SUMMARY: Insights into FIT2 function underscore its pivotal role in LD formation and lipid homeostasis. Understanding its involvement in ER proteostasis and very low density lipoprotein biogenesis has broad implications for metabolic diseases and cancer. Therapeutic strategies targeting FIT2 may offer novel approaches to modulate lipid metabolism and mitigate associated pathologies. Further research is needed to elucidate the full spectrum of FIT2's interactions within cellular lipid and protein networks, potentially uncovering new therapeutic avenues for metabolic and ER stress-related disorders.
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Retículo Endoplásmico , Proteostasis , Humanos , Retículo Endoplásmico/metabolismo , Animales , Lipoproteínas/metabolismo , Lipoproteínas/genética , Gotas Lipídicas/metabolismo , Respuesta de Proteína Desplegada , Metabolismo de los Lípidos/genética , Proteínas de la MembranaRESUMEN
Enterococcus faecalis is an opportunistic pathogen frequently causing nosocomial infections. The virulence of this organism is underpinned by its capacity to evade phagocytosis, allowing dissemination in the host. Immune evasion requires a surface polysaccharide produced by all enterococci, known as the enterococcal polysaccharide antigen (EPA). EPA consists of a cell wall-anchored rhamnose backbone substituted by strain-specific polysaccharides called 'decorations', essential for the biological activity of this polymer. However, the structural determinants required for innate immune evasion remain unknown, partly due to a lack of suitable validated assays. Here, we describe a quantitative, in vitro assay to investigate how EPA decorations alter phagocytosis. Using the E. faecalis model strain OG1RF, we demonstrate that a mutant with a deletion of the locus encoding EPA decorations can be used as a platform strain to express heterologous decorations, thereby providing an experimental system to investigate the inhibition of phagocytosis by strain-specific decorations. We show that the aggregation of cells lacking decorations is increasing phagocytosis and that this process does not involve the recognition of lipoproteins by macrophages. Collectively, our work provides novel insights into innate immune evasion by enterococci and paves the way for further studies to explore the structure/function relationship of EPA decorations.
Asunto(s)
Enterococcus faecalis , Evasión Inmune , Lipoproteínas , Macrófagos , Fagocitosis , Enterococcus faecalis/inmunología , Enterococcus faecalis/metabolismo , Enterococcus faecalis/genética , Lipoproteínas/metabolismo , Lipoproteínas/genética , Macrófagos/microbiología , Macrófagos/inmunología , Macrófagos/metabolismo , Polisacáridos Bacterianos/metabolismo , Polisacáridos Bacterianos/inmunología , Humanos , Antígenos Bacterianos/metabolismo , Antígenos Bacterianos/inmunología , Antígenos Bacterianos/genética , Inmunidad Innata , Virulencia , Animales , RatonesRESUMEN
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.
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Aterosclerosis , Colesterol , Humanos , Aterosclerosis/sangre , Colesterol/sangre , Colesterol/metabolismo , Triglicéridos/sangre , Factores de Riesgo , Biomarcadores/sangre , LDL-Colesterol/sangre , Lipoproteínas/sangre , Lipoproteínas/metabolismo , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/prevención & controlRESUMEN
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.
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Colesterol , Iris , Melanocitos , Transducción de Señal , Melanocitos/metabolismo , Humanos , Colesterol/metabolismo , Iris/metabolismo , Lipoproteínas/metabolismo , Melanosomas/metabolismo , Lipoproteínas LDL/metabolismo , Espectrometría de Masas en Tándem/métodos , Cromatografía de Gases y Espectrometría de Masas/métodos , Cromatografía Liquida/métodos , Lipasa/metabolismo , Melaninas/metabolismo , Ésteres del Colesterol/metabolismoRESUMEN
Lipids are primarily transported in the bloodstream by lipoproteins, which are macromolecules of lipids and conjugated proteins also known as apolipoproteins. The processes of lipoprotein assembly, secretion, transportation, modification, and clearance are crucial components of maintaining a healthy lipid metabolism. Disruption in any of these steps results in pathophysiological abnormalities such as dyslipidemia, obesity, insulin resistance, inflammation, atherosclerosis, peripheral artery disease, and cardiovascular diseases. By studying these genetic mutations, researchers can gain valuable insights into the underlying mechanisms that govern the relationship between protein structure and its physiological role. These lipoproteins, including HDL, LDL, lipoprotein(a), and VLDL, mainly serve the purpose of transporting lipids between tissues and organs. However, studies have provided evidence that apo(a) also possesses protective properties against pathogens. In the future, the field of study will be significantly influenced by the integration of recombinant DNA technology and human site-specific mutagenesis for treating hereditary disorders. Several medications are available for the treatment of dyslipoproteinemia. These include statins, fibrates, ezetimibe, niacin, PCSK9 inhibitors, evinacumab, DPP 4 inhibitors, glucagon-like peptide-1 receptor agonists GLP1RAs, GLP-1, and GIP dual receptor agonists, in addition to SGLT2 inhibitors. This current review article exhibits, for the first time, a comprehensive reflection of the available body of publications concerning the impact of lipoproteins on metabolic well-being across various pathological states.
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Dislipidemias , Lipoproteínas , Humanos , Lipoproteínas/metabolismo , Metabolismo de los Lípidos , Enfermedades Cardiovasculares/prevención & control , Resistencia a la Insulina , Obesidad/metabolismo , AnimalesRESUMEN
BACKGROUND: Primary liver cancer is the third leading cause of cancer related deaths worldwide, and the disease is associated with high incidence rate of thrombosis. Studies indicate that Tissue Factor Pathway Inhibitor (TFPI) plays a role in cancer development. We aimed to study its expression, clinical role and regulation by micro RNAs (miRNAs) in hepatocellular carcinoma (HCC). METHODS: Publically available datasets were used for clinical analysis of TFPI and miRNAs expression by web analysis tools. miRNA mimics targeting TFPIα 3'untranslated region (UTR) were selected from target prediction programs and verified by luciferase reporter assay. In vitro effects of miRNAs overexpression in HCC cell lines on TFPI expression and cell proliferation and apoptosis were analysed. RESULTS: TFPI expression was significantly increased in HCC tumours compared to normal tissue. Low TFPI tumour expression was associated with better survival probability. Four candidate miRNAs were selected from the target prediction programs. miR-7-5p and miR-1236-3p were validated in HepG2 and Huh7 cells to reduce TFPI mRNA and protein levels following overexpression. Furthermore, miR-7-5p and miR-1236-3p reduced TFPIα-3'UTR-controlled luciferase activity. The two validated miRNAs inhibited proliferation of HepG2 cells, and had clinical significance in HCC. CONCLUSIONS: TFPI was increased in HCC tumours compared to normal tissue and high TFPI expression was associated with an unfavorable outcome in HCC patients. miR-7-5p and miR-1236-3p were identified as novel regulators of TFPI in vitro.
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Carcinoma Hepatocelular , Lipoproteínas , Neoplasias Hepáticas , MicroARNs , Femenino , Humanos , Masculino , Persona de Mediana Edad , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/mortalidad , Línea Celular Tumoral , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Células Hep G2 , Lipoproteínas/genética , Lipoproteínas/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , MicroARNs/genética , MicroARNs/metabolismo , PronósticoRESUMEN
BACKGROUND: Phospholipid transfer protein (PLTP) transfers surface phospholipids between lipoproteins and as such plays a role in lipoprotein metabolism, but with unclear effects on coronary artery disease (CAD) risk. We aimed to investigate the associations of genetically-influenced PLTP activity with 1-H nuclear magnetic resonance (1H-NMR) metabolomic measures and with CAD. Furthermore, using factorial Mendelian randomization (MR), we examined the potential additional effect of genetically-influenced PLTP activity on CAD risk on top of genetically-influenced low-density lipoprotein-cholesterol (LDL-C) lowering. METHODS: Using data from UK Biobank, genetic scores for PLTP activity and LDL-C were calculated and dichotomised based on the median, generating four groups with combinations of high/low PLTP activity and high/low LDL-C levels for the factorial MR. Linear and logistic regressions were performed on 168 metabolomic measures (N = 58,514) and CAD (N = 318,734, N-cases=37,552), respectively, with results expressed as ß coefficients (in standard deviation units) or odds ratios (ORs) and 95% confidence interval (CI). RESULTS: Irrespective of the genetically-influenced LDL-C, genetically-influenced low PLTP activity was associated with a higher high-density lipoprotein (HDL) particle concentration (ß [95% CI]: 0.03 [0.01, 0.05]), smaller HDL size (-0.14 [-0.15, -0.12]) and higher triglyceride (TG) concentration (0.04 [0.02, 0.05]), but not with CAD (OR 0.99 [0.97, 1.02]). In factorial MR analyses, genetically-influenced low PLTP activity and genetically-influenced low LDL-C had independent associations with metabolomic measures, and genetically-influenced low PLTP activity did not show an additional effect on CAD risk. CONCLUSIONS: Low PLTP activity associates with higher HDL particle concentration, smaller HDL particle size and higher TG concentration, but no association with CAD risk was observed.
Asunto(s)
Enfermedad de la Arteria Coronaria , Proteínas de Transferencia de Fosfolípidos , Humanos , Enfermedad de la Arteria Coronaria/metabolismo , Enfermedad de la Arteria Coronaria/genética , Enfermedad de la Arteria Coronaria/sangre , Proteínas de Transferencia de Fosfolípidos/genética , Proteínas de Transferencia de Fosfolípidos/metabolismo , Masculino , Femenino , LDL-Colesterol/sangre , LDL-Colesterol/metabolismo , Análisis de la Aleatorización Mendeliana , Persona de Mediana Edad , Lipoproteínas/metabolismo , Lipoproteínas/sangreRESUMEN
The global prevalence of cardiovascular diseases (CVD) continues to rise steadily, making it a leading cause of mortality worldwide. Atherosclerosis (AS) serves as a primary driver of these conditions, commencing silently at an early age and culminating in adverse cardiovascular events that severely impact patients' quality of life or lead to fatality. Dyslipidemia, particularly elevated levels of low-density lipoprotein cholesterol (LDL-C), plays a pivotal role in AS pathogenesis as an independent risk factor. Research indicates that abnormal LDL-C accumulation within arterial walls acts as a crucial trigger for atherosclerotic plaque formation. As the disease progresses, plaque accumulation may rupture or dislodge, resulting in thrombus formation and complete blood supply obstruction, ultimately causing myocardial infarction, cerebral infarction, and other common adverse cardiovascular events. Despite adequate pharmacologic therapy targeting LDL-C reduction, patients with cardiometabolic abnormalities remain at high risk for disease recurrence, highlighting the importance of addressing lipid risk factors beyond LDL-C. Recent attention has focused on the causal relationship between triglycerides, triglyceride-rich lipoproteins (TRLs), and their remnants in AS risk. Genetic, epidemiologic, and clinical studies suggest a causal relationship between TRLs and their remnants and the increased risk of AS, and this dyslipidemia may be an independent risk factor for adverse cardiovascular events. Particularly in patients with obesity, metabolic syndrome, diabetes, and chronic kidney disease, disordered TRLs and its remnants levels significantly increase the risk of atherosclerosis and cardiovascular disease development. Accumulation of over-synthesized TRLs in plasma, impaired function of enzymes involved in TRLs lipolysis, and impaired hepatic clearance of cholesterol-rich TRLs remnants can lead to arterial deposition of TRLs and its remnants, promoting foam cell formation and arterial wall inflammation. Therefore, understanding the pathogenesis of TRLs-induced AS and targeting it therapeutically could slow or impede AS progression, thereby reducing cardiovascular disease morbidity and mortality, particularly coronary atherosclerotic heart disease.
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Enfermedades Cardiovasculares , Lipoproteínas , Triglicéridos , Humanos , Enfermedades Cardiovasculares/metabolismo , Enfermedades Cardiovasculares/etiología , Lipoproteínas/metabolismo , Triglicéridos/metabolismo , Triglicéridos/sangre , Aterosclerosis/metabolismo , Animales , Dislipidemias/metabolismo , Factores de RiesgoRESUMEN
Escherichia coli (E. coli), a Gram-negative bacterium, is the primary pathogen responsible for endometritis in dairy cattle. The outer membrane components of E. coli, namely lipopolysaccharide (LPS) and bacterial lipoprotein, have the capacity to trigger the host's innate immune response through pattern recognition receptors (PRRs). Tolerance to bacterial cell wall components, including LPS, may play a crucial role as an essential regulatory mechanism during bacterial infection. However, the precise role of Braun lipoprotein (BLP) tolerance in E. coli-induced endometritis in dairy cattle remains unclear. In this study, we aimed to investigate the impact of BLP on the regulation of E. coli infection-induced endometritis in dairy cattle. The presence of BLP was found to diminish the expression and release of proinflammatory cytokines (IL-8 and IL-6), while concurrently promoting the expression and release of the anti-inflammatory cytokine IL-10 in endometrial epithelial cells (EECs). Furthermore, BLP demonstrated the ability to impede the activation of MAPK (ERK and p38) and NF-κB (p65) signaling pathways, while simultaneously enhancing signaling through the STAT3 pathway in EECs. Notably, BLP exhibited a dual role, acting both as an activator of TLR2 and as a regulator of TLR2 activation in LPS- and E. coli-treated EECs. In E. coli-infected endometrial explants, the presence of BLP was noted to decrease the release of proinflammatory cytokines and the expression of HMGB1, while simultaneously enhancing the release of anti-inflammatory cytokines. Collectively, our findings provide evidence that the bacterial component BLP plays a protective role in E. coli-induced endometritis in dairy cattle.
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Enfermedades de los Bovinos , Endometrio , Infecciones por Escherichia coli , Escherichia coli , Animales , Femenino , Bovinos , Infecciones por Escherichia coli/veterinaria , Infecciones por Escherichia coli/inmunología , Endometrio/metabolismo , Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/metabolismo , Enfermedades de los Bovinos/inmunología , Lipoproteínas/metabolismo , Endometritis/veterinaria , Endometritis/microbiología , Endometritis/metabolismo , Endometritis/inmunología , Citocinas/metabolismo , Citocinas/genética , Tolerancia InmunológicaRESUMEN
Coagulopathy, microvascular alterations and concomitant organ dysfunctions are hallmarks of sepsis. Attempts to attenuate coagulation activation with an inhibitor of tissue factor (TF), i.e. tissue factor pathway inhibitor (TFPI), revealed no survival benefit in a heterogenous group of sepsis patients, but a potential survival benefit in patients with an international normalized ratio (INR) < 1.2. Since an increased TF/TFPI ratio determines the procoagulant activity specifically on microvascular endothelial cells in vitro, we investigated whether TF/TFPI ratio in blood is associated with INR alterations, organ dysfunctions, disseminated intravascular coagulation (DIC) and outcome in septic shock. Twenty-nine healthy controls (HC) and 89 patients with septic shock admitted to a tertiary ICU were analyzed. TF and TFPI in blood was analyzed and related to organ dysfunctions, DIC and mortality. Patients with septic shock had 1.6-fold higher levels of TF and 2.9-fold higher levels of TFPI than HC. TF/TFPI ratio was lower in septic shock compared to HC (0.003 (0.002-0.005) vs. 0.006 (0.005-0.008), p < 0.001). Non-survivors had higher TFPI levels compared to survivors (43038 (29354-54023) vs. 28041 (21675-46582) pg/ml, p = 0.011). High TFPI levels were associated with acute kidney injury, liver dysfunction, DIC and disease severity. There was a positive association between TF/TFPI ratio and troponin T (b = 0.531 (0.309-0.754), p < 0.001). A high TF/TFPI ratio is exclusively associated with myocardial injury but not with other organ dysfunctions. Systemic TFPI levels seem to reflect disease severity. These findings point towards a pathophysiologic role of TF/TFPI in sepsis-induced myocardial injury.
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Lipoproteínas , Choque Séptico , Tromboplastina , Humanos , Choque Séptico/sangre , Choque Séptico/metabolismo , Tromboplastina/metabolismo , Masculino , Femenino , Lipoproteínas/sangre , Lipoproteínas/metabolismo , Persona de Mediana Edad , Anciano , Insuficiencia Multiorgánica/sangre , Insuficiencia Multiorgánica/etiología , Coagulación Intravascular Diseminada/sangre , Estudios de Casos y Controles , Adulto , Biomarcadores/sangreRESUMEN
Cardiovascular diseases (CVDs) remain the leading cause of mortality worldwide, accounting for 32% of global deaths, according to the World Health Organization (WHO) [...].
Asunto(s)
Apolipoproteínas , Enfermedades Cardiovasculares , Lipoproteínas , Humanos , Apolipoproteínas/metabolismo , Enfermedades Cardiovasculares/metabolismo , Lipoproteínas/metabolismoRESUMEN
Peptidoglycan (PG) sacculi surround the cytoplasmic membrane, maintaining cell integrity by withstanding internal turgor pressure. During cell growth, PG endopeptidases cleave the crosslinks of the fully closed sacculi, allowing for the incorporation of new glycan strands and expansion of the peptidoglycan mesh. Outer-membrane-anchored NlpI associates with hydrolases and synthases near PG synthesis complexes, facilitating spatially close PG hydrolysis. Here, we present the structure of adaptor NlpI in complex with the endopeptidase MepS, revealing atomic details of how NlpI recruits multiple MepS molecules and subsequently influences PG expansion. NlpI binding elicits a disorder-to-order transition in the intrinsically disordered N-terminal of MepS, concomitantly promoting the dimerization of monomeric MepS. This results in the alignment of two asymmetric MepS dimers respectively located on the two opposite sides of the dimerization interface of NlpI, thus enhancing MepS activity in PG hydrolysis. Notably, the protein level of MepS is primarily modulated by the tail-specific protease Prc, which is known to interact with NlpI. The structure of the Prc-NlpI-MepS complex demonstrates that NlpI brings together MepS and Prc, leading to the efficient MepS degradation by Prc. Collectively, our results provide structural insights into the NlpI-enabled avidity effect of cellular endopeptidases and NlpI-directed MepS degradation by Prc.
Asunto(s)
Endopeptidasas , Lipoproteínas , Peptidoglicano , Peptidoglicano/metabolismo , Endopeptidasas/metabolismo , Endopeptidasas/química , Lipoproteínas/metabolismo , Lipoproteínas/química , Unión Proteica , Multimerización de Proteína , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/química , Modelos Moleculares , Cristalografía por Rayos X , Hidrólisis , Escherichia coli/metabolismoRESUMEN
Blood coagulation mediated by pig tissue factor (TF), which is expressed in pig tissues, causes an instant blood-mediated inflammatory reaction during pig-to-human xenotransplantation. Previously, we generated a soluble pig tissue factor pathway inhibitor α fusion immunoglobulin (TFPI-Ig) which inhibits pig TF activity more efficiently than human TFPI-Ig in human plasma. In this study, we generated several pig TFPI-Ig mutants and tested the efficacy of these mutants in preventing pig-to-human xenogeneic blood coagulation. Structurally important amino acid residues of pig TFPI-Ig were changed into different residues by site-directed mutagenesis. Subsequently, a retroviral vector encoding each cDNA of several pig TFPI-Ig mutants was cloned and transduced into CHO-K1 cells. After establishing stable cell lines expressing each of the pig TFPI-Ig mutants, soluble proteins were produced and purified for evaluating their inhibitory effects on pig TF-mediated blood coagulation in human plasma. The replacement of K36 and K257 with R36 and H257, respectively, in pig TFPI-Ig more efficiently blocked pig TF activity in human plasma when compared with the wild-type pig TFPI-Ig. These results may provide additional information to understand the structure of pig TFPIα, and an improved pig TFPI-Ig variant that more efficiently blocks pig TF-mediated blood coagulation during pig-to-human xenotransplantation.