ABSTRACT
Cholesterol is highly enriched at the plasma membrane (PM), and lipid transfer proteins may deliver cholesterol to the PM in a nonvesicular manner. Here, through a mini-screen, we identified the oxysterol binding protein (OSBP)-related protein 2 (ORP2) as a novel mediator of selective cholesterol delivery to the PM. Interestingly, ORP2-mediated enrichment of PM cholesterol was coupled with the removal of phosphatidylinositol 4, 5-bisphosphate (PI(4,5)P2) from the PM. ORP2 overexpression or deficiency impacted the levels of PM cholesterol and PI(4,5)P2, and ORP2 efficiently transferred both cholesterol and PI(4,5)P2in vitro. We determined the structure of ORP2 in complex with PI(4,5)P2 at 2.7 Å resolution. ORP2 formed a stable tetramer in the presence of PI(4,5)P2, and tetramerization was required for ORP2 to transfer PI(4,5)P2. Our results identify a novel pathway for cholesterol delivery to the PM and establish ORP2 as a key regulator of both cholesterol and PI(4,5)P2 of the PM.
Subject(s)
Cell Membrane/metabolism , Cholesterol/metabolism , Hepatocytes/metabolism , Phosphatidylinositol 4,5-Diphosphate/metabolism , Receptors, Steroid/metabolism , Biological Transport , Cell Line, Tumor , HEK293 Cells , Humans , Models, Molecular , Protein Multimerization , Protein Structure, Quaternary , Receptors, Steroid/chemistry , Receptors, Steroid/genetics , Structure-Activity RelationshipABSTRACT
RATIONALE: Although diabetic peripheral neuropathic pain (DPNP) and depression have been recognized for many years, their co-morbidity relationship and effective treatment choices remain uncertain. OBJECTIVES: To evaluate the antidepressant effect of carvedilol on streptozotocin-induced DPNP mice, and the relationship with gut microbiota. METHODS: The hyperalgesia and depressive behaviors of mice with comorbidity of DPNP and depression were confirmed by pain threshold of the mechanical sensitivity test (MST), immobility time of the tail suspension test (TST) and the forced swimming test (FST). The anti-depressive effect and fecal gut microbiota composition were studied in DPNP mice treated with carvedilol (10 mg/kg/day), and the relationships between them were analyzed by Spearman's correlation. RESULTS: Depression was successfully induced in DPNP mice. Carvedilol can reverse the decreased mechanical pain threshold and relieve the depressive behaviors of DPNP mice, while increasing the abundance of Prevotella, Ruminococcus, Helicobacter and Desulfovibrio, and decreasing the abundance of Akkermansia and Allobaculum. CONCLUSIONS: Carvedilol can alleviate the mechanical hyperalgesia and alter gut microbiota to ameliorate the depression-like behaviors which induced by DPNP.
ABSTRACT
Understanding the environmental fate of organic carbon associated with iron (OC-Fe) is critically important for investigating OC preservation in aquatic systems. Here, we first investigate 13C and 14C isotopes of OC-Fe within grain size-fractionated sediments retrieved from the East China Sea and estimate their sources and reactivities of OC-Fe through isotope-mixing models and thermal pyrolysis approaches in order to reveal the fate of OC-Fe on continental shelves influenced by hydrodynamic processes. Our results show that the OC-Fe proportion in total OC (fOC-Fe) in the sortable silt fractions (20-63 µm) is the highest among three grain size fractions, likely suggesting that hydrodynamics may enhance the iron protection on OC. In addition, Δ14COC-Fe values fall within the range of from -358.73 to -64.03, and both Δ14COC-Fe values and ancient OC-Fe% exhibit strong positive linear relationships with fOC-Fe. This emphasized that the hydrodynamic processes may cause the ancient OC to be tightly associated with Fe, accompanying OC-Fe aging. Our findings shed new light on the preservation of OC-Fe in marginal seas to advance the recognition of carbon "rusty sinks" in seafloor sediments.
ABSTRACT
BACKGROUND: Postoperative cognitive dysfunction (POCD) is a common complication after anesthesia/surgery, especially among elderly patients, and poses a significant threat to their postoperative quality of life and overall well-being. While it is widely accepted that elderly patients may experience POCD following anesthesia/surgery, the exact mechanism behind this phenomenon remains unclear. Several studies have indicated that the interaction between silent mating type information regulation 2 homologue 1 (SIRT1) and brain-derived neurotrophic factor (BDNF) is crucial in controlling cognitive function and is strongly linked to neurodegenerative disorders. Hence, this research aims to explore how SIRT1/BDNF impacts cognitive decline caused by anesthesia/surgery in aged mice. METHODS: Open field test (OFT) was used to determine whether anesthesia/surgery affected the motor ability of mice, while the postoperative cognitive function of 18 months old mice was evaluated with Novel object recognition test (NORT), Object location test (OLT) and Fear condition test (FC). The expressions of SIRT1 and other molecules were analyzed by western blot and immunofluorescence staining. The hippocampal synaptic plasticity was detected by Golgi staining and Long-term potentiation (LTP). The effects of SIRT1 and BDNF overexpression as well as chemogenetic activation of glutamatergic neurons in hippocampal CA1 region of 18 months old vesicular glutamate transporter 1 (VGLUT1) mice on POCD were further investigated. RESULTS: The research results revealed that older mice exhibited cognitive impairment following intramedullary fixation of tibial fracture. Additionally, a notable decrease in the expression of SIRT1/BDNF and neuronal excitability in hippocampal CA1 glutamatergic neurons was observed. By increasing levels of SIRT1/BDNF or enhancing glutamatergic neuron excitability in the CA1 region, it was possible to effectively mitigate synaptic plasticity impairment and ameliorate postoperative cognitive dysfunction. CONCLUSIONS: The decline in SIRT1/BDNF levels leading to changes in synaptic plasticity and neuronal excitability in older mice could be a significant factor contributing to cognitive impairment after anesthesia/surgery.
Subject(s)
Brain-Derived Neurotrophic Factor , CA1 Region, Hippocampal , Down-Regulation , Neuronal Plasticity , Neurons , Postoperative Cognitive Complications , Sirtuin 1 , Animals , Sirtuin 1/metabolism , Sirtuin 1/genetics , Brain-Derived Neurotrophic Factor/metabolism , Brain-Derived Neurotrophic Factor/genetics , Mice , Neurons/metabolism , Postoperative Cognitive Complications/metabolism , Postoperative Cognitive Complications/etiology , CA1 Region, Hippocampal/metabolism , Male , Mice, Inbred C57BL , Long-Term Potentiation , Glutamic Acid/metabolism , Cognitive Dysfunction/etiology , Cognitive Dysfunction/metabolism , Cognitive Dysfunction/physiopathologyABSTRACT
Radiofrequency (RF) diodes used for fifth and sixth-generation (5G and 6G) mobile and wireless communication networks generally require ultrahigh cut-off frequencies and high integration densities of devices with different functions on a single chip and at low cost. Carbon nanotube diodes are promising devices for radiofrequency applications, but the cut-off frequencies are still far below the theoretical estimates. Here, a carbon nanotube diode that operates in the millimeter-wave frequency bands and is based on solution-processed, high-purity carbon nanotube network films is reported. The carbon nanotube diodes exhibit an intrinsic cut-off frequency over 100 GHz and the as-measured bandwidth can exceed 50 GHz at least. Furthermore, The rectification ratio of the carbon nanotube diode by approximately three times by using yttrium oxide for local p-type doping in the diode channel is improved.
ABSTRACT
BACKGROUND: Acute viral myocarditis (AVMC) is an inflammatory disease of the myocardium. Evidence indicates that dysbiosis of gut microbiome and related metabolites intimately associated with cardiovascular diseases through the gut-heart axis. METHODS: We built mouse models of AVMC, then applied 16 S rDNA gene sequencing and UPLC-MS/MS metabolomics to explore variations of gut microbiome and disturbances of cardiac metabolic profiles. RESULTS: Compared with Control group, analysis of gut microbiota showed lower diversity in AVMC, decreased relative abundance of genera mainly belonging to the phyla Bacteroidetes, and increased of phyla Proteobacteria. Metabolomics analysis showed disturbances of cardiac metabolomics, including 62 increased and 84 decreased metabolites, and mainly assigned to lipid, amino acid, carbohydrate and nucleotide metabolism. The steroid hormone biosynthesis, cortisol synthesis and secretion pathway were particularly enriched in AVMC. Among them, such as estrone 3-sulfate, desoxycortone positively correlated with disturbed gut microbiome. CONCLUSION: In summary, both the structure of the gut microbiome community and the cardiac metabolome were significantly changed in AVMC. Our findings suggest that gut microbiome may participate in the development of AVMC, the mechanism may be related to its role in dysregulated metabolites such as steroid hormone biosynthesis.
Subject(s)
Gastrointestinal Microbiome , Myocarditis , Animals , Mice , Myocarditis/metabolism , Gastrointestinal Microbiome/genetics , Chromatography, Liquid , Tandem Mass Spectrometry , Metabolome , Metabolomics , Steroids , Hormones , RNA, Ribosomal, 16S/geneticsABSTRACT
Although most patients with acute viral myocarditis recover spontaneously, some patients progress to heart failure. Perturbations in innate immunity may partially explain the heterogeneity of clinical outcomes. As the most abundant immune cells in the heart, cardiac macrophages have heterogeneous origins, including embryonic-derived resident macrophages (ResMÏs) and monocyte-derived macrophages (MoMFs). However, the time course change and role of cardiac macrophage subsets has not been fully explored. In the present study, we found that BALB/c mice had prolonged MoMF accumulation and low proportions of ResMÏs that could not be restored to normal levels. MoMFs of BALB/c mice generally exhibit an M1-dominant functional phenotype. Moreover, the preferential depletion of MoMF by a C-C chemokine receptor type 2 (CCR2) inhibitor resulted in improved acute myocarditis and chronic fibrosis, as well as the recovery of ResMÏs number and reduced CD4+ T cell expansion. Hence, immunomodulatory therapy that targets the balance among cardiac macrophages and modulates their function is expected to prevent the progression of cardiac injury to overt heart failure and improve adverse outcomes.
Subject(s)
Coxsackievirus Infections , Heart Failure , Myocarditis , Mice , Animals , Enterovirus B, Human/physiology , Heart , MacrophagesABSTRACT
Though the evidence for antibiotic resistance spread via plant microbiome is mounting, studies regarding antibiotic resistome in the plant seed, a reproductive organ and important food resource, are still in their infancy. This study investigated the effects of long-term organic fertilization on seed bacterial endophytes, resistome, and their intergenerational transfer in the microcosm. A total of 99 antibiotic resistance genes (ARGs) and 26 mobile genetic elements (MGEs) were detected by high-throughput quantitative PCR. The amount of organic fertilizer applied was positively correlated to the number and relative abundance of seed-associated ARGs and MGEs. Moreover, the transmission of ARGs from the rhizosphere to the seed was mainly mediated by the shared bacteria and MGEs. Notably, the rhizosphere of progeny seedlings derived from seeds harboring abundant ARGs was found to have a higher relative abundance of ARGs. Using structural equation models, we further revealed that seed resistome and MGEs were key factors affecting the ARGs in the progeny rhizosphere, implying the seed was a potential resistome reservoir for rhizosphere soil. This study highlights the overlooked role of seed endophytes in the dissemination of resistome in the soil-plant continuum, and more attention should be paid to plant seeds as vectors of ARGs within the "One-Health" framework.
Subject(s)
Anti-Bacterial Agents , Genes, Bacterial , Anti-Bacterial Agents/pharmacology , Soil/chemistry , Drug Resistance, Microbial/genetics , Bacteria/genetics , Seeds/chemistry , Soil Microbiology , ManureABSTRACT
INTRODUCTION: Pulmonary hypertension due to left heart failure (PH-LHF) is a disease with high prevalence and 3-year mortality rates. Consequently, timely identification of patients with high mortality risk is critical. This study aimed to build a nomogram for predicting 3-year mortality and screening high-risk PH-LHF patients. METHODS: This nomogram was developed on a training cohort of 175 patients with PH-LHF diagnosed by right heart catheterization. Multivariate Cox regression was used to identify independent predictors and develop this nomogram. The median total points obtained from the nomogram were used as a cutoff point, and patients were classified into low- and high-risk groups. The concordance index (C-index) and calibration curve were utilized to ascertain the predictive accuracy and discriminative ability of the nomogram. External validation was performed using a validation cohort of 77 PH-LHF patients from other centers. RESULTS: Multivariate Cox regression showed that the New York Heart Association Functional classification (NYHA FC), uric acid level, and mean pulmonary arterial pressure were all independent predictors and incorporated into the nomogram. The nomogram showed good discrimination (C-index of 0.756; 95% CI: 0.688-0.854) and good calibration. The Kaplan-Meier survival analysis showed that patients in the high-risk group had worse survival (p < 0.001). In the external validation, the nomogram showed both good discrimination (C-index of 0.738; 95% CI: 0.591-0.846) and calibration. CONCLUSION: The nomogram had a good performance in predicting 3-year mortality and can effectively identify high-risk patients. The nomogram may help to reduce the mortality of PH-LHF.
Subject(s)
Heart Failure , Hypertension, Pulmonary , Humans , Nomograms , Retrospective Studies , Heart Failure/complications , Heart Failure/diagnosis , RegistriesABSTRACT
Oxidative stress impairs functional recovery after intracerebral hemorrhage (ICH). Histone deacetylase 6 (HDAC6) plays an important role in the initiation of oxidative stress. However, the function of HDAC6 in ICH and the underlying mechanism of action remain elusive. We demonstrated here that HDAC6 knockout mice were resistant to oxidative stress following ICH, as assessed by the MDA and NADPH/NADP+ assays and ROS detection. HDAC6 deficiency also resulted in reduced neuronal apoptosis and lower expression levels of apoptosis-related proteins. Further mechanistic studies showed that HDAC6 bound to malate dehydrogenase 1 (MDH1) and mediated-MDH1 deacetylation on the lysine residues at position 121 and 298. MDH1 acetylation was inhibited in HT22 cells that were challenged with ICH-related damaging agents (Hemin, Hemoglobin, and Thrombin), but increased when HDAC6 was inhibited, suggesting an interplay between HDAC6 and MDH1. The acetylation-mimetic mutant, but not the acetylation-resistant mutant, of MDH1 protected neurons from oxidative injury. Furthermore, HDAC6 inhibition failed to alleviate brain damage after ICH when MDH1 was knockdown. Taken together, our study showed that HDAC6 inhibition protects against brain damage during ICH through MDH1 acetylation.
Subject(s)
Apoptosis , Brain Injuries , Acetylation , Animals , Cerebral Hemorrhage/drug therapy , Cerebral Hemorrhage/genetics , Histone Deacetylase 6/genetics , Histone Deacetylase 6/metabolism , Mice , Neurons/metabolism , Oxidative Stress , Up-RegulationABSTRACT
Although B cells are essential for humoral immunity and show noteworthy immunomodulatory activity through antibody-independent functions, the role of B cells in regulating Treg cell responses remains controversial. Tregs (CD4+CD25+Foxp3+) are considered to play an immunoprotective role in viral myocarditis (VMC) by controlling autoimmune effector T cells. Here, we proved that B-cell knockout can not only lead to significant reductions in Tregs in the spleen, blood, and heart of VMC mice but also decrease the activation and immune function of splenic Tregs, which was reversed by adoptive transfer of B cells; the transcription levels of TGF-ß and Foxp3 in the myocardium were also significantly reduced. B-cell depletion by anti-CD20 impaired the anti-inflammatory function of splenic Tregs and the homeostasis of myocardial Tregs population. Moreover, B cells can convert CD4+CD25- T cells into Foxp3+ and Foxp3-, two functionally suppressive Treg subgroups. Although the reduction in myocardial inflammation in BKO mice indicates that B cells may play a proinflammatory role, the beneficial side of B cells cannot be ignored, that is, to control autoimmunity by maintaining Treg numbers. The results observed in the animal model of VMC highlight the potential harm of rituximab in the nonselective depletion of B cells in clinical applications.
Subject(s)
Myocarditis , Mice , Animals , T-Lymphocytes, Regulatory , Myocardium , Adoptive Transfer , B-Lymphocytes , Forkhead Transcription Factors , Mice, Inbred C57BLABSTRACT
BACKGROUND: The aberrant distribution of peripheral B cell subsets is associated with the pathogenesis of a variety of inflammatory and autoimmune diseases. However, the distribution of peripheral B cell subsets in patients with idiopathic dilated cardiomyopathy (DCM) remains to be elucidated. METHODS: Twenty-seven patients with idiopathic DCM (DCM group), 18 control patients with heart failure (HF group) and 21 healthy individuals (HC group) were included in this study. Peripheral B cell subsets were analysed using multicolour flow cytometry. The plasma ß1 adrenergic receptor (ß1-AR) autoantibody titre was determined using ELISA. Additionally, clinical features were also collected. RESULTS: Compared with the HF and HC groups, the percentage of B1 cells was significantly decreased, whereas the percentage of transitional B cells (Tr) was significantly increased in the DCM group. Notably, the percentage of B1 cells was significantly lower in patients with ß1-AR autoantibody-positive DCM than in ß1-AR autoantibody-negative patients. The correlation analysis showed that the percentage of B1 cells was negatively correlated with N-terminal pro-brain natriuretic peptide (NT-proBNP) levels and positively correlated with the left ventricular ejection fraction in patients with DCM. CONCLUSION: As shown in the present study, the percentage of B1 cells in the peripheral blood of patients with idiopathic DCM is abnormally decreased, especially in ß1-AR autoantibody-positive patients, while the percentage of Tr cells is significantly increased, indicating that B1 cells and Tr cells may be implicated in the pathogenesis of idiopathic DCM. The decrease in the percentage of B1 cells is directly related to the severity of DCM.
Subject(s)
B-Lymphocyte Subsets , Cardiomyopathy, Dilated , Autoantibodies , B-Lymphocyte Subsets/pathology , Cardiomyopathy, Dilated/complications , Humans , Pilot Projects , Precursor Cells, B-Lymphoid/pathology , Stroke Volume , Ventricular Function, LeftABSTRACT
BACKGROUND: There is no generally accepted comprehensive risk prediction model cooperating risk factors associated with heart failure and pulmonary hemodynamics for patients with pulmonary hypertension due to left heart disease (PH-LHD). We aimed to explore outcome correlates and evaluate incremental prognostic value of pulmonary hemodynamics for risk prediction in PH-LHD. METHODS: Consecutive patients with chronic heart failure undergoing right heart catheterization were prospectively enrolled. The primary endpoint was all-cause mortality. Individual variable selection was performed by machine learning methods. Cox proportional hazards models were conducted to identify the association between variables and mortality. Incremental value of hemodynamics was evaluated based on the Seattle heart failure model (SHFM) and Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) scores. RESULTS: A total of 276 PH-LHD patients were enrolled, with a median follow-up time of 34.7 months. By L1-penalized regression model and random forest approach, diastolic pressure gradient (DPG) and mixed venous oxygen saturation (SvO2) were the hemodynamic predictors most strongly associated with mortality (coefficient: 0.0255 and -0.0176, respectively), with consistent significance after adjusted for SHFM [DPG: HR 1.067, 95% CI 1.024-1.113, P = 0.022; SvO2: HR 0.969, 95% CI 0.953-0.985, P = 0.002] or MAGGIC (DPG: HR 1.069, 95% CI 1.026-1.114, P = 0.011; SvO2: HR 0.970, 95% CI 0.954-0.986, P = 0.004) scores. The inclusion of DPG and SvO2 improved risk prediction compared with using SHFM [net classification improvement (NRI): 0.468 (0.161-0.752); integrated discriminatory index (IDI): 0.092 (0.035-0.171); likelihood ratio test: P < 0.001] or MAGGIC [NRI: 0.298 (0.106-0.615); IDI: 0.084 (0.033-0.151); likelihood ratio: P < 0.001] scores alone. CONCLUSION: In PH-LHD, pulmonary hemodynamics can provide incremental prognostic value for risk prediction. CLINICAL TRIAL REGISTRATION: NCT02164526 at https://clinicaltrials.gov .
Subject(s)
Heart Failure/complications , Hemodynamics , Hypertension, Pulmonary/etiology , Pulmonary Circulation , Aged , Cardiac Catheterization , China , Chronic Disease , Female , Heart Failure/diagnosis , Heart Failure/mortality , Heart Failure/physiopathology , Humans , Hypertension, Pulmonary/diagnosis , Hypertension, Pulmonary/mortality , Hypertension, Pulmonary/physiopathology , Male , Middle Aged , Predictive Value of Tests , Prognosis , Prospective Studies , Registries , Risk Assessment , Risk Factors , Time FactorsABSTRACT
BACKGROUND AND OBJECTIVE: Nationally representative reports on the characteristics and long-term survival of pulmonary arterial hypertension (PAH) from developing countries are scarce. The applicability of the current main risk stratifications and the longitudinal changes in goal-oriented treatments have yet to be elucidated in real-world settings. Therefore, we aimed to provide insights into the characteristics, goal-oriented treatments and survival of PAH in China and to explore the applicability of the main risk stratifications in our independent cohort. METHODS: PAH patients were consecutively enrolled from a national prospective multicentre registry. Data on baseline, follow-up re-evaluation and therapeutic changes were collected. RESULTS: A total of 2031 patients were enrolled, with congenital heart disease (CHD)-PAH (45.2%) being the most common aetiology. The mean age was 35 ± 12 years, and 76.2% were females. At baseline, approximately 20% of the patients with intermediate or high risk received combination treatment. At follow-up, approximately half of the re-evaluated patients did not achieve low-risk profiles, and even among patients who received combination therapy at baseline, 4% of them still worsened. The rate of combination therapy increased significantly from 6.7% before 2015 to 35.5% thereafter. The main risk assessment tools demonstrated good performance for predicting survival both at baseline and at follow-up. CONCLUSION: Chinese PAH patients show both similar and distinct features compared to other countries. Current main risk stratifications can significantly discriminate patients at different risk levels. There were still many patients not achieving low-risk profiles at follow-up, indicating more aggressive treatment should be implemented to optimize the goal-oriented treatment strategy.
Subject(s)
Heart Defects, Congenital , Pulmonary Arterial Hypertension , Adult , Familial Primary Pulmonary Hypertension , Female , Goals , Humans , Male , Middle Aged , Registries , Young AdultABSTRACT
Viral myocarditis (VMC), which is defined as inflammation of the myocardium with consequent myocardial injury, may develop chronic disease eventually leading to dilated cardiomyopathy (DCM). Molecular mechanisms underlying the progression from acute VMC (aVMC), to chronic VMC (cVMC) and finally to DCM, are still unclear. Here, we established mouse models of VMC and DCM with Coxsackievirus B3 infection and conducted NMR-based metabolomic analysis of aqueous metabolites extracted from cardiac tissues of three histologically classified groups including aVMC, cVMC and DCM. We showed that these three pathological groups were metabolically distinct from their normal counterparts and identified three impaired metabolic pathways shared by these pathological groups relative to normal controls, including nicotinate and nicotinamide metabolism; alanine, aspartate and glutamate metabolism; and D-glutamine and D-glutamate metabolism. We also identified two extra impaired metabolic pathways in the aVMC group, including glycine, serine and threonine metabolism; and taurine and hypotaurine metabolism Furthermore, we identified potential cardiac biomarkers for metabolically distinguishing these three pathological stages from normal controls. Our results indicate that the metabolomic analysis of cardiac tissues can provide valuable insights into the molecular mechanisms underlying the progression from acute VMC to DCM.
Subject(s)
Cardiomyopathy, Dilated , Coxsackievirus Infections , Myocarditis , Niacin , Alanine , Animals , Aspartic Acid , Biomarkers , Cardiomyopathy, Dilated/metabolism , Coxsackievirus Infections/metabolism , Coxsackievirus Infections/pathology , Enterovirus B, Human , Glutamic Acid , Glutamine , Glycine , Mice , Mice, Inbred BALB C , Myocarditis/metabolism , Myocarditis/pathology , Niacinamide , Serine , Taurine , ThreonineABSTRACT
BACKGROUND: Inflammatory cells infiltrate into the ischemic and hypoxic myocardial tissue after myocardial infarction. B cells gather at the site of myocardial injury and secrete cytokines to regulate immune inflammation and fiber repair processes. METHODS: The animal experiment used ligation of the left anterior descending (LAD) artery of C57BL/6 mice to establish a mouse acute myocardial infarction (AMI) model to observe changes in activated B cells and cytokines at different time points. Twelve-week-old C57BL/6 male mice were randomly divided into the Sham group (24 mice) (thread under the LAD artery without ligation) and the AMI group (64 mice). In addition, C57BL/6 B-cell knockout (BKO) mice and C57BL/6 wild-type (WT) mice were used to establish AMI models to observe the expression levels of cardiomyocyte cytokines, such as TNF-α IL-1ß, IL-6, TGF-ß1, COL1-A1, COL3-AIII, TIMP, and MMP9. Moreover, pathological and collagen changes in the myocardium were analysed. One-way ANOVA and LSD method was used for comparisons of multiple and pairwise groups respectively. P < 0.05 indicated significant differences. RESULTS: An AMI model of C57BL/6 mice was established successfully. The ratio of activated B cells and the expression of TNF-α, IL-1ß, IL-6, TGF-ß1, and B cell activating factor (BAFF) in the 5-day subgroup were the highest in the myocardium, spleen and peripheral blood with the most obvious myocardial inflammatory cell infiltration. The cytokines mRNA expression levels in the 5-day subgroup of the BKO group were decreased compared with those in the WT group (P < 0.05). Among the 2-week subgroups of the Sham, WT and BKO groups, the the LVEDd and LVESd of the BKO group were lower than those of the WT group (P < 0.05), and the left ventricular ejection fraction was higher than that of the WT group (P < 0.05). CONCLUSION: Activated B cells participate in the sustained state of myocardial inflammation and immune system activation after AMI, and may affect the metabolism of myocardial collagen after AMI by secreting cytokines. Moreover, B cells promote the expression of myocardial collagen Type I and Type III and damage the left ventricular ejection function.
Subject(s)
B-Lymphocytes/metabolism , Collagen Type III/metabolism , Collagen Type I/metabolism , Cytokines/metabolism , Lymphocyte Activation , Myocardial Infarction/metabolism , Myocardium/metabolism , Animals , B-Cell Activating Factor/genetics , B-Cell Activating Factor/metabolism , B-Lymphocytes/immunology , Collagen Type I/genetics , Collagen Type I, alpha 1 Chain , Collagen Type III/genetics , Cytokines/genetics , Disease Models, Animal , Fibrosis , Male , Matrix Metalloproteinase 9/metabolism , Mice, Inbred C57BL , Mice, Knockout , Myocardial Infarction/immunology , Myocardial Infarction/pathology , Myocardial Infarction/physiopathology , Myocardium/immunology , Myocardium/pathology , Signal Transduction , Stroke Volume , Tissue Inhibitor of Metalloproteinases/metabolism , Ventricular Function, LeftABSTRACT
Hundreds of nuclear, cytoplasmic, and mitochondrial proteins within multicellular eukaryotes have hydroxyl groups of specific serine and threonine residues modified by the monosaccharide N-acetylglucosamine (GlcNAc). This modification, known as O-GlcNAc, has emerged as a central regulator of both cell physiology and human health. A key emerging function of O-GlcNAc appears to be to regulate cellular protein homeostasis. We previously showed, using overexpressed model proteins, that O-GlcNAc modification can occur cotranslationally and that this process prevents premature degradation of such nascent polypeptide chains. Here, we use tandem metabolic engineering strategies to label endogenously occurring nascent polypeptide chains within cells using O-propargyl-puromycin (OPP) and target the specific subset of nascent chains that are cotranslationally glycosylated with O-GlcNAc by metabolic saccharide engineering using tetra-O-acetyl-2-N-azidoacetyl-2-deoxy-d-galactopyranose (Ac4GalNAz). Using various combinations of sequential chemoselective ligation strategies, we go on to tag these analytes with a series of labels, allowing us to define conditions that enable their robust labeling. Two-step enrichment of these glycosylated nascent chains, combined with shotgun proteomics, allows us to identify a set of endogenous cotranslationally O-GlcNAc modified proteins. Using alternative targeted methods, we examine three of these identified proteins and further validate their cotranslational O-GlcNAcylation. These findings detail strategies to enable isolation and identification of extremely low abundance endogenous analytes present within complex protein mixtures. Moreover, this work opens the way to studies directed at understanding the roles of O-GlcNAc and other cotranslational protein modifications and should stimulate an improved understanding of the role of O-GlcNAc in cytoplasmic protein quality control and proteostasis.
Subject(s)
Acetylglucosamine/metabolism , Mitochondrial Proteins/metabolism , Monosaccharides/metabolism , Acetylglucosamine/chemistry , HEK293 Cells , Humans , Metabolic Engineering , Mitochondrial Proteins/chemistry , Molecular Conformation , Monosaccharides/chemistryABSTRACT
BACKGROUND: Secondary brain damage caused by the innate immune response and subsequent proinflammatory factor production is a major factor contributing to the high mortality of intracerebral haemorrhage (ICH). Nucleotide-binding oligomerization domain 1 (NOD1)/receptor-interacting protein 2 (RIP2) signalling has been reported to participate in the innate immune response and inflammatory response. Therefore, we investigated the role of NOD1/RIP2 signalling in mice with collagenase-induced ICH and in cultured primary microglia challenged with hemin. METHODS: Adult male C57BL/6 mice were subjected to collagenase for induction of ICH model in vivo. Cultured primary microglia and BV2 microglial cells (microglial cell line) challenged with hemin aimed to simulate the ICH model in vitro. We first defined the expression of NOD1 and RIP2 in vivo and in vitro using an ICH model by western blotting. The effect of NOD1/RIP2 signalling on ICH-induced brain injury volume, neurological deficits, brain oedema, and microglial activation were assessed following intraventricular injection of either ML130 (a NOD1 inhibitor) or GSK583 (a RIP2 inhibitor). In addition, levels of JNK/P38 MAPK, IκBα, and inflammatory factors, including tumour necrosis factor-α (TNF-α), interleukin (IL)-1ß, and inducible nitric oxide synthase (iNOS) expression, were analysed in ICH-challenged brain and hemin-exposed cultured primary microglia by western blotting. Finally, we investigated whether the inflammatory factors could undergo crosstalk with NOD1 and RIP2. RESULTS: The levels of NOD1 and its adaptor RIP2 were significantly elevated in the brains of mice in response to ICH and in cultured primary microglia, BV2 cells challenged with hemin. Administration of either a NOD1 or RIP2 inhibitor in mice with ICH prevented microglial activation and neuroinflammation, followed by alleviation of ICH-induced brain damage. Interestingly, the inflammatory factors interleukin (IL)-1ß and tumour necrosis factor-α (TNF-α), which were enhanced by NOD1/RIP2 signalling, were found to contribute to the NOD1 and RIP2 upregulation in our study. CONCLUSION: NOD1/RIP2 signalling played an important role in the regulation of the inflammatory response during ICH. In addition, a vicious feedback cycle was observed between NOD1/RIP2 and IL-1ß/TNF-α, which could to some extent result in sustained brain damage during ICH. Hence, our study highlights NOD1/RIP2 signalling as a potential therapeutic target to protect the brain against secondary brain damage during ICH.
Subject(s)
Cerebral Hemorrhage/metabolism , Cerebral Hemorrhage/pathology , Nod1 Signaling Adaptor Protein/metabolism , Receptor-Interacting Protein Serine-Threonine Kinase 2/metabolism , Animals , Cytokines/metabolism , Inflammation/metabolism , Inflammation/pathology , Male , Mice , Mice, Inbred C57BL , Microglia/metabolism , Signal Transduction/physiologyABSTRACT
Alcohol consumption causes renal injury and compromises kidney function. The underlying mechanism of the alcoholic kidney disease remains largely unknown. In the present study, an alcoholic renal fibrosis animal model was first employed which mice received liquid diet containing alcohol for 4 to 12 weeks. The Masson's Trichrome staining analysis showed that kidney fibrosis increased at week 8 and 12 in the animal model that was further confirmed by albumin assay, Western blot, immunostaining and real-time PCR of fibrotic indexes (collagen I and α-SMA). In vitro analysis also confirmed that alcohol significantly induced fibrotic response (collagen I and α-SMA) in HK2 tubular epithelial cells. Importantly, both in vivo and in vitro studies showed alcohol treatments decreased Smad7 and activated Smad3. We further determined how the alcohol affected the balance of Smad7 (inhibitory Smad) and Smad3 (regulatory Smad). Genome-wide methylation sequencing showed an increased DNA methylation of many genes and bisulfite sequencing analysis showed an increased DNA methylation of Smad7 after alcohol ingestion. We also found DNA methylation of Smad7 was mediated by DNMT1 in ethyl alcohol (EtOH)-treated HK2 cells. Knockdown of Nox2 or Nox4 decreased DNMT1 and rebalanced Smad7/Smad3 axis, and thereby relieved EtOH-induced fibrotic response. The inhibition of reactive oxygen species by the intraperitoneal injection of apocynin attenuated renal fibrosis and restored renal function in the alcoholic mice. Collectively, we established novel in vivo and in vitro alcoholic kidney fibrosis models and found that alcohol induces renal fibrosis by activating oxidative stress-induced DNA methylation of Smad7. Suppression of Nox-mediated oxidative stress may be a potential therapy for long-term alcohol abuse-induced kidney fibrosis.
Subject(s)
DNA Methylation/genetics , Ethanol/adverse effects , Kidney Diseases/genetics , NADPH Oxidase 2/metabolism , NADPH Oxidase 4/metabolism , Smad7 Protein/metabolism , Acetophenones/pharmacology , Animals , Cell Line , DNA (Cytosine-5-)-Methyltransferase 1/metabolism , DNA Methylation/drug effects , Disease Models, Animal , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Fibrosis , Humans , Kidney/drug effects , Kidney/pathology , Kidney Diseases/pathology , Kidney Tubules/pathology , Liver/drug effects , Liver/pathology , Male , Mice, Inbred C57BL , Models, Biological , Reactive Oxygen Species/metabolism , Reproducibility of Results , Signal Transduction/drug effects , Smad3 Protein/metabolism , Transforming Growth Factor beta1/metabolismABSTRACT
BACKGROUND: Bilateral medial medullary infarction (MMI) is uncommon and bilateral medial pons infarction (MPI) is even rarer. "Heart appearance" on magnetic resonance imaging (MRI) is a characteristic presentation of bilateral medial medullary infarction (MMI). CASE PRESENTATION: We present 67-year-old Chinese diabetic and hypertensive female patient affected with "heart appearance-like" infarction in bilateral ponto-medullary junction on MRI. Abnormal signal was observed in the bilateral ponto-medullary junction on T1, T2, fluid-attenuated inversion recovery and apparent diffusion coefficient (ADC). The whole brain digital subtraction angiography (DSA) showed the basilar artery and vertebral artery remained intact. Therefore, we speculated that the bilateral ponto-medullary junction infarction might be caused by the deep perforating branch of the basilar artery. CONCLUSIONS: As far as we know, the "heart appearance-like" infraction in bilateral ponto-medullary junction was not reported. Our case also suggests that bilateral ischemic infraction involvement of the medulla and pon is possible even in the context of an intact basilar artery.