ABSTRACT
Group 3 innate lymphoid cells (ILC3s) regulate immunity and inflammation, yet their role in cancer remains elusive. Here, we identify that colorectal cancer (CRC) manifests with altered ILC3s that are characterized by reduced frequencies, increased plasticity, and an imbalance with T cells. We evaluated the consequences of these changes in mice and determined that a dialog between ILC3s and T cells via major histocompatibility complex class II (MHCII) is necessary to support colonization with microbiota that subsequently induce type-1 immunity in the intestine and tumor microenvironment. As a result, mice lacking ILC3-specific MHCII develop invasive CRC and resistance to anti-PD-1 immunotherapy. Finally, humans with dysregulated intestinal ILC3s harbor microbiota that fail to induce type-1 immunity and immunotherapy responsiveness when transferred to mice. Collectively, these data define a protective role for ILC3s in cancer and indicate that their inherent disruption in CRC drives dysfunctional adaptive immunity, tumor progression, and immunotherapy resistance.
Subject(s)
Colonic Neoplasms/immunology , Colonic Neoplasms/therapy , Disease Progression , Immunity, Innate , Immunotherapy , Lymphocytes/immunology , Animals , Cell Communication/drug effects , Cell Plasticity/drug effects , Colonic Neoplasms/microbiology , Feces/microbiology , Histocompatibility Antigens Class II/metabolism , Humans , Immune Checkpoint Inhibitors/pharmacology , Immunity, Innate/drug effects , Inflammation/immunology , Inflammation/pathology , Inflammatory Bowel Diseases/immunology , Inflammatory Bowel Diseases/microbiology , Inflammatory Bowel Diseases/pathology , Intestines/pathology , Lymphocytes/drug effects , Mice, Inbred C57BL , Microbiota/drug effects , Neoplasm Invasiveness , T-Lymphocytes/drug effects , T-Lymphocytes/immunology , Tissue DonorsABSTRACT
Microbial colonization of the mammalian intestine elicits inflammatory or tolerogenic T cell responses, but the mechanisms controlling these distinct outcomes remain poorly understood, and accumulating evidence indicates that aberrant immunity to intestinal microbiota is causally associated with infectious, inflammatory and malignant diseases1-8. Here we define a critical pathway controlling the fate of inflammatory versus tolerogenic T cells that respond to the microbiota and express the transcription factor RORγt. We profiled all RORγt+ immune cells at single-cell resolution from the intestine-draining lymph nodes of mice and reveal a dominant presence of T regulatory (Treg) cells and lymphoid tissue inducer-like group 3 innate lymphoid cells (ILC3s), which co-localize at interfollicular regions. These ILC3s are distinct from extrathymic AIRE-expressing cells, abundantly express major histocompatibility complex class II, and are necessary and sufficient to promote microbiota-specific RORγt+ Treg cells and prevent their expansion as inflammatory T helper 17 cells. This occurs through ILC3-mediated antigen presentation, αV integrin and competition for interleukin-2. Finally, single-cell analyses suggest that interactions between ILC3s and RORγt+ Treg cells are impaired in inflammatory bowel disease. Our results define a paradigm whereby ILC3s select for antigen-specific RORγt+ Treg cells, and against T helper 17 cells, to establish immune tolerance to the microbiota and intestinal health.
Subject(s)
Immune Tolerance , Intestines , Lymphocytes , Microbiota , T-Lymphocytes, Regulatory , Animals , Immunity, Innate , Integrin alphaV/metabolism , Interleukin-2/immunology , Intestines/immunology , Intestines/microbiology , Lymph Nodes/cytology , Lymph Nodes/immunology , Lymphocytes/immunology , Microbiota/immunology , Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism , Single-Cell Analysis , T-Lymphocytes, Regulatory/immunology , Th17 Cells/immunology , Transcription Factors/metabolism , Inflammatory Bowel Diseases/immunology , Inflammatory Bowel Diseases/pathologyABSTRACT
Maintenance of metabolic homeostasis is secured by metabolite-sensing systems, which can be overwhelmed by constant macronutrient surplus in obesity. Not only the uptake processes but also the consumption of energy substrates determine the cellular metabolic burden. We herein describe a novel transcriptional system in this context comprised of peroxisome proliferator-activated receptor alpha (PPARα), a master regulator for fatty acid oxidation, and C-terminal binding protein 2 (CtBP2), a metabolite-sensing transcriptional corepressor. CtBP2 interacts with PPARα to repress its activity, and the interaction is enhanced upon binding to malonyl-CoA, a metabolic intermediate increased in tissues in obesity and reported to suppress fatty acid oxidation through inhibition of carnitine palmitoyltransferase 1. In line with our preceding observations that CtBP2 adopts a monomeric configuration upon binding to acyl-CoAs, we determined that mutations in CtBP2 that shift the conformational equilibrium toward monomers increase the interaction between CtBP2 and PPARα. In contrast, metabolic manipulations that reduce malonyl-CoA decreased the formation of the CtBP2-PPARα complex. Consistent with these in vitro findings, we found that the CtBP2-PPARα interaction is accelerated in obese livers while genetic deletion of CtBP2 in the liver causes derepression of PPARα target genes. These findings support our model where CtBP2 exists primarily as a monomer in the metabolic milieu of obesity to repress PPARα, representing a liability in metabolic diseases that can be exploited to develop therapeutic approaches.
Subject(s)
Alcohol Oxidoreductases , Co-Repressor Proteins , Obesity , PPAR alpha , Humans , Fatty Acids/metabolism , Liver/metabolism , Obesity/genetics , Obesity/metabolism , PPAR alpha/genetics , PPAR alpha/metabolism , Alcohol Oxidoreductases/metabolism , Co-Repressor Proteins/metabolism , Allosteric RegulationABSTRACT
BACKGROUND: To evaluate the seasonal variability of urinary albumin to creatinine ratio (UACR) and eGFR and these effects on three-year eGFR slope in persons with type 2 diabetes (T2D). METHODS: A total of 1135 persons with T2D were analyzed in this single-center, retrospective cohort study in Japan. The standard deviation (SD) of UACR (SD [UACR]) and SD of eGFR (SD [eGFR]) were calculated for each person's 10-point data during the three years, and a multiple linear regression analysis was performed to evaluate associations with eGFR slope. A sensitivity analysis was performed in a group with no medication changes (n = 801). RESULTS: UACR exhibited seasonal variability, being higher in winter and lower in spring, early summer, and autumn especially in the UACR ≥ 30 mg/g subgroup, while eGFR showed no seasonal variability. The eGFR slope was significantly associated with SD (eGFR) (regression coefficient -0.170 [95% CI -0.189--0.151]) and SD (UACR) (0.000 [-0.001-0.000]). SGLT-2 inhibitors, baseline eGFR, and baseline systolic blood pressure (SBP) were also significantly associated. These associated factors, except baseline SBP, were still significant in the sensitivity analysis. CONCLUSIONS: The UACR showed clear seasonal variability. Moreover, SD (UACR) and SD (eGFR) were independently associated with a three-year eGFR slope in persons with T2D. TRIAL REGISTRATION: This study was not registered for clinical trial registration because it was a retrospective observational study.
Subject(s)
Albuminuria , Creatinine , Diabetes Mellitus, Type 2 , Glomerular Filtration Rate , Humans , Diabetes Mellitus, Type 2/urine , Retrospective Studies , Male , Female , Creatinine/urine , Middle Aged , Japan , Albuminuria/urine , Aged , Seasons , Cohort Studies , East Asian PeopleABSTRACT
Although ear canal electroencephalogram (EEG) recording has received interest from basic and applied research communities, evidence on how it can be implemented in practice is limited. The present study involving eight male participants including the authors presents the utility of our ear canal electrode and method by demonstrating both comparability of ear canal EEG to those at nearby sites and distinctiveness that ear canal event-related potentials (ERPs) could have. For this purpose, we used the balanced noncephalic electrode reference and an experimental paradigm with an error-feedback sound. Clear auditory ERPs were detected at the ear canal sites with a sufficiently low noise level comparable with those at conventional sites. The N1c, a temporal maximum subcomponent, spread over the bilateral temporal sites, including the ear canals and earlobes. While consecutive signals are generally highly similar between the ear canal and the earlobe, the N1c was larger at the ear canal than the earlobe, as demonstrated by the conventional frequentist and the hierarchical Bayesian modelling approaches. Although an evident caveat is that our sample was limited in terms of size and sex, the general capability indicates that the structure of our ear canal electrode provides EEG measurement that can be used in basic and applied settings. Our experimental method can also be an ERP-based test that conveniently assesses the capability of existing and future ear canal electrodes. The distinctive nature of the ERPs to the error-feedback sound may be utilized to examine the basic aspects of auditory ERPs and to test the processes involved in feedback-guided behaviour of participants.
Subject(s)
Ear Canal , Evoked Potentials , Humans , Male , Feedback , Bayes Theorem , ElectrodesABSTRACT
Topological defects, the fundamental entities arising from symmetry-breaking, have captivated the attention of physicists, mathematicians, and materials scientists for decades. Here we propose and demonstrate a novel method for robust control of topological defects in a liquid crystal (LC), an ideal testbed for the investigation of topological defects. A liquid layer is introduced on the LC in microwells in a microfluidic device. The liquid/LC interface facilitates the control of the LC alignment thereby introducing different molecules in the liquid/LC phase. A topological defect is robustly formed in a microwell when the liquid/LC interface and the microwell surface impose planar and homeotropic alignment, respectively. We also demonstrate the formation/disappearance of topological defects by light illumination, realized by dissolving photo-responsive molecules in the LC. Our platform that facilitates the control of LC topological defects by the introduction of different molecules and external stimuli could have potential for sensor applications.
ABSTRACT
BACKGROUND: Mild cognitive impairment (MCI) is not just a prodrome to dementia, but a very important intervention point to prevent dementia caused by Alzheimer's disease (AD). It has long been known that people with AD have a higher frequency of falls with some gait instability. Recent evidence suggests that vestibular impairment is disproportionately prevalent among individuals with MCI and dementia due to AD. Therefore, we hypothesized that the measurement of balance capability is helpful to identify individuals with MCI. METHODS: First, we developed a useful method to evaluate balance capability as well as vestibular function using Nintendo Wii balance board as a stabilometer and foam rubber on it. Then, 49 healthy volunteers aged from 56 to 75 with no clinically apparent cognitive impairment were recruited and the association between their balance capability and cognitive function was examined. Cognitive functions were assessed by MoCA, MMSE, CDR, and TMT-A and -B tests. RESULTS: The new balance capability indicator, termed visual dependency index of postural stability (VPS), was highly associated with cognitive impairment assessed by MoCA, and the area under the receiver operating characteristic (ROC) curve was more than 0.8, demonstrating high sensitivity and specificity (app. 80% and 60%, respectively). CONCLUSIONS: Early evidence suggests that VPS measured using Nintendo Wii balance board as a stabilometer helps identify individuals with MCI at an early and preclinical stage with high sensitivity, establishing a useful method to screen MCI.
Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Humans , Aged , Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/epidemiology , Cognitive Dysfunction/complications , Alzheimer Disease/diagnosis , Cognition , ROC Curve , Neuropsychological Tests , Sensitivity and SpecificityABSTRACT
Recent studies have shown that the interactions between condensates and biological membranes are of functional importance. Here, we study how the interaction between complex coacervates and liposomes as model systems can lead to wetting, membrane deformation, and endocytosis. Depending on the interaction strength between coacervates and liposomes, the wetting behavior ranged from nonwetting to engulfment (endocytosis) and complete wetting. Endocytosis of coacervates was found to be a general phenomenon: coacervates made from a wide range of components could be taken up by liposomes. A simple theory taking into account surface energies and coacervate sizes can explain the observed morphologies. Our findings can help to better understand condensate-membrane interactions in cellular systems and provide new avenues for intracellular delivery using coacervates.
Subject(s)
Endocytosis , Liposomes , Cell Membrane , WettabilityABSTRACT
Although changes in serum sclerostin levels at 12 months after infusion of zoledronic acid have been reported, the changes in sclerostin levels at earlier time points are poorly understood. We reanalyzed the study data of a previous phase 1 pharmacokinetic study and investigated the correlation between changes in sclerostin levels and relevant factors in calcium metabolism. A total of 24 Japanese female subjects with primary postmenopausal osteoporosis were administered a single 4- or 5-mg dose of zoledronic acid. Serum and urine samples were collected on days 15, 29, 90, 180, and 365 after administration. Serum levels of calcium, phosphate, intact parathyroid hormone (iPTH), and sclerostin were measured. Levels of serum sclerostin were unchanged from baseline on days 15 and 29, but increased significantly on day 90, subsequently decreased significantly on day 180, and returned to baseline levels on day 365. A significant negative correlation was observed between changes in iPTH levels at early time points and sclerostin levels at later time points. This suggests that sclerostin was negatively regulated by iPTH, and the decrease in sclerostin may indicate the start of bone formation during later time points after zoledronic acid injection.
Subject(s)
Bone Morphogenetic Proteins , Osteoporosis, Postmenopausal , Biomarkers , Female , Genetic Markers , Humans , Osteoporosis, Postmenopausal/drug therapy , Parathyroid Hormone , Zoledronic AcidABSTRACT
Some strains of lactic acid bacteria (LAB) have anti-inflammatory effects, but the mechanism underlying the alleviation of inflammation by LAB is not fully understood. In this study, we examined the inhibitory effect of a certain strain of LAB, Lactobacillus paracasei, on inflammasome activation, which is associated with various inflammatory disorders. Using bone marrow-derived macrophages from BALB/c mice, we found that L. paracasei, but not L. rhamnosus, suppressed NLRP3 inflammasome activation and inhibited subsequent caspase-1 activation and IL-1ß secretion. L. paracasei also had inhibitory effects on AIM2 and NLRC4 inflammasome activation as well as the NLRP3 inflammasome. These inhibitory effects of L. paracasei on inflammasome activation were dependent on autocrine IL-10 induced by L. paracasei-stimulated macrophages. Furthermore, IL-10 production by L. paracasei-stimulated macrophages was involved with phagocytosis and the NOD2 signaling pathway in macrophages. In addition to in vitro studies, oral administration of L. paracasei in C57BL/6 mice reduced monosodium urate crystal-induced peritoneal inflammation in vivo. Moreover, continuous intake of L. paracasei in C57BL/6 mice alleviated high fat diet-induced insulin resistance and aging-induced expression of biomarkers for T cell senescence. Taken together, we demonstrated that L. paracasei inhibits inflammasome activation in vitro and exhibits an anti-inflammatory function in vivo. These results indicate that LAB that have inhibitory effects on inflammasome activation might contribute to the alleviation of inflammation-related disorders.
Subject(s)
Inflammasomes/immunology , Lacticaseibacillus paracasei/immunology , Macrophages/immunology , Signal Transduction/immunology , Animals , Apoptosis Regulatory Proteins/immunology , Calcium-Binding Proteins/immunology , Caspase 1/immunology , DNA-Binding Proteins/immunology , Inflammation/chemically induced , Inflammation/immunology , Inflammation/prevention & control , Interleukin-10/immunology , Mice , Mice, Inbred BALB C , NLR Family, Pyrin Domain-Containing 3 Protein/immunology , Nod2 Signaling Adaptor Protein/immunologyABSTRACT
BACKGROUND: Polymorphous adenocarcinoma is a common intraoral minor salivary gland carcinoma in Western countries but is extremely rare in Japan. The current study aimed to characterize the clinicopathological features and status of molecular alterations of polymorphous adenocarcinoma-associated genes, such as PRKD1/2/3, ARID1A, and DDX3X, in a large cohort of Japanese patients with polymorphous adenocarcinoma. METHODS: We examined the cases of 36 Japanese patients with salivary gland polymorphous adenocarcinoma and 26 cases involving histopathological mimics. To detect gene splits, fluorescence in situ hybridization was carried out for polymorphous adenocarcinoma-associated genes. Additionally, we applied a SNaPshot multiplex assay to identify PRKD1 hotspot mutations. RESULTS: This study revealed the indolent clinical course of polymorphous adenocarcinoma with a high 10-year overall survival rate (92.9%), accompanied by occasional local recurrences and cervical lymph node metastasis (23.3%). Twenty cases (55.6%) of polymorphous adenocarcinoma (but none of the mimics) exhibited alterations in at least one polymorphous adenocarcinoma-associated gene. Rearrangement of polymorphous adenocarcinoma-associated genes and PRKD1 E710D were identified in 17 (47.2%) and 4 (11.1%) cases, respectively; one case showed coexisting PRKD3 split and PRKD1 E710D. In the multivariate analysis, high clinical stage (p = 0.0005), the presence of prominent nucleoli (p = 0.0003), and ARID1A split positivity (p = 0.004) were independent risk factors for disease-free survival. CONCLUSION: Japanese patients with polymorphous adenocarcinoma showed clinicopathological features similar to those reported in Western countries. This study disclosed that polymorphous adenocarcinoma-associated genetic alterations were common and specific findings in polymorphous adenocarcinomas. The diagnostic role and possible prognostic significance of polymorphous adenocarcinoma-associated genetic alterations in polymorphous adenocarcinomas were suggested.
Subject(s)
Adenocarcinoma , Salivary Gland Neoplasms , Adenocarcinoma/pathology , Biomarkers, Tumor/genetics , Humans , In Situ Hybridization, Fluorescence , Japan , Salivary Gland Neoplasms/genetics , Salivary Gland Neoplasms/pathology , Salivary Glands/pathologyABSTRACT
BACKGROUND: Few prospective reports of universal screening for Lynch syndrome exist for patients with endometrial cancer. In this study, we performed immunohistochemical staining for DNA mismatch repair-related genes (MLH1, MSH2, MSH6 and PMS2), to determine the extent to which Lynch syndrome can be diagnosed in endometrial cancer patients through universal screening. METHODS: We recruited 116 consecutive patients assumed to have uterine corpus malignancy from October 2019 to February 2021 in a prospective observational study. We performed immunohistochemical for mismatch repair-related proteins on samples from 100 patients who had surgicopathologically confirmed diagnoses of endometrial cancer. Samples with missing immunohistochemical results for any of the proteins had subsequent universal screening tests for microsatellite instability, DNA methylation of the MLH1 promoter region and mismatch repair genetics. RESULTS: We identified 19 (19.0%) patients with lost results for any of the proteins. All 19 patient samples had subsequent screening tests. We identified the microsatellite instability-high phenotype in 84.2% (16/19) of these patients and MLH1 methylation in 57.9% (11/19). Mismatch repair genetic testing detected two pathological variants, in MSH2 and MSH6, which indicated that the prevalence of Lynch syndrome was 2.0% in our cohort. Two cases of unclassified variant (MSH6) and one case of benign variant (PMS2) were also detected. CONCLUSIONS: Initial screening by immunohistochemical is an effective method in universal screening for Lynch syndrome in endometrial cancer patients.
Subject(s)
Colorectal Neoplasms, Hereditary Nonpolyposis , Endometrial Neoplasms , Colorectal Neoplasms, Hereditary Nonpolyposis/complications , Colorectal Neoplasms, Hereditary Nonpolyposis/diagnosis , Colorectal Neoplasms, Hereditary Nonpolyposis/genetics , DNA Mismatch Repair/genetics , Early Detection of Cancer/methods , Endometrial Neoplasms/diagnosis , Endometrial Neoplasms/genetics , Endometrial Neoplasms/pathology , Female , Humans , Immunohistochemistry , Microsatellite Instability , Mismatch Repair Endonuclease PMS2/genetics , MutL Protein Homolog 1/genetics , MutS Homolog 2 Protein/genetics , MutS Homolog 2 Protein/metabolism , Prospective StudiesABSTRACT
OBJECTIVE: To develop preoperative models as a guide to indications for neoadjuvant chemotherapy (NAC) and regional lymph node dissection (LND) before and at radical nephroureterectomy (RNU), respectively, in patients with non-metastatic upper tract urothelial carcinoma (UTUC) by incorporating the systemic immune-inflammation index (SII). METHODS: This retrospective study enrolled 103 consecutive patients with UTUC undergoing RNU. The SII was calculated as neutrophils × platelets / lymphocytes. Multivariable Cox proportional hazard model was used to develop preoperative models for cancer-specific survival (CSS) and overall survival (OS). A model for predicting muscle invasion was developed using logistic regression analysis. Harrell's concordance-index (c-index) or the area under the receiver operating characteristic curve (AUC) was used to evaluate the accuracy of the models. RESULTS: During follow-up (median: 41 months), 26 and three patients died of UTUC and other causes, respectively. Performance status > 0, clinical tumor (cT) stage ≥ 3, and SII > 520 were independent adverse prognosticators for CSS, and one point was assigned to each prognosticator. Risk score models comprising the sum of the points stratified patients into three risk groups (0, 1, and 2-3; P < 0.001 for CSS and OS) with respective c-indices of 0.843 and 0.820. SII > 677 and ≥ cT3 were independently associated with muscle invasion. A model based on these variables predicted muscle invasion with AUC of 0.804. CONCLUSION: Preoperative SII is significantly associated with worse survival outcomes and muscle invasion in patients with non-metastatic UTUC. Our preoperative predictive models may serve as a guide to indications for NAC and LND.
Subject(s)
Carcinoma, Transitional Cell , Urinary Bladder Neoplasms , Urologic Neoplasms , Carcinoma, Transitional Cell/pathology , Humans , Inflammation , Muscles/pathology , Prognosis , Retrospective Studies , Urologic Neoplasms/surgeryABSTRACT
Differential hypoxia may occur after the initiation of femorofemoral veno-arterial extracorporeal membrane oxygenation (VA ECMO) if cardiac function improves while severe respiratory failure is still present, one of the most difficult problems encountered during VA ECMO. Reconfiguration to veno-arterio-venous ECMO (V-AV ECMO) is one of several methods of dealing with differential hypoxia. V-AV ECMO requires triple cannulation and careful management of the reinjection flow, but the risk of bleeding is lower than in a surgical procedure, such as central ECMO or a subclavian artery graft. Herein, we reported a patient with a massive pulmonary embolism who received VA ECMO, which was reconfigured to V-AV ECMO 3 days later when differential hypoxia occurred. A drainage cannula was newly inserted via the right internal jugular vein, and an existing drainage cannula was used for reinjection after repositioning it caudally. V-AV ECMO is an effective and feasible treatment for differential hypoxia despite the paucity of the procedure to date.
Subject(s)
Extracorporeal Membrane Oxygenation , Pulmonary Embolism , Respiratory Insufficiency , Humans , Extracorporeal Membrane Oxygenation/methods , Respiratory Insufficiency/therapy , Cannula , Pulmonary Embolism/therapy , HypoxiaABSTRACT
A GGGGCC hexanucleotide repeat expansion in the C9orf72 gene is linked to the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) (C9-ALS/FTD). Unconventional translation of the hexanucleotide repeat expansion generates five dipeptide repeat proteins (DPRs). The molecular mechanism underlying the DPR-linked neurotoxicity is under investigation. In this study, using cell-based models, we show that poly-proline-arginine DPR (poly-PR), the most neurotoxic DPR in vitro, binds to adenosine deaminase acting on RNA (ADAR)1p110 and ADAR2 and inhibits their RNA editing activity. We further show that poly-PR impairs cellular stress response that is mediated by ADAR1p110. These results together suggest that the poly-PR-mediated inhibition of the ADAR activity contributes to C9-ALS/FTD-linked neurotoxicity.
Subject(s)
Adenosine Deaminase/genetics , Arginine/genetics , C9orf72 Protein/genetics , Proline/genetics , RNA-Binding Proteins/genetics , Adenosine Deaminase/metabolism , Animals , Arginine/metabolism , C9orf72 Protein/metabolism , Dipeptides/genetics , Dipeptides/metabolism , HeLa Cells , Humans , Mice , Neurons/metabolism , Proline/metabolism , RNA-Binding Proteins/metabolismABSTRACT
Metal wires have been used as an alternative to liquid junctions for the connection of solutions in microfabricated electrochemical devices. They exhibit similar performance to liquid junctions, provided that the interfacial potentials at both ends of the wires were appropriately canceled. Cyclic voltammograms of devices with liquid junctions and metal wires were very similar when no current or a low current flowed through the metal wire between the working and reference electrodes. Iridium wires with iridium oxide at both ends facilitated canceling of the interfacial potentials at either end of the junction particularly well, and were used effectively for voltammetry, amperometry, and potentiometry by adjusting the pH of the solutions in the working and reference electrode compartments to be equal. This approach was used to effectively integrate a reliable common reference electrode between multiple working electrodes and to conduct automated electrochemical control of solution transport in microfluidic systems.
Subject(s)
Biosensing Techniques , Electrodes , PotentiometryABSTRACT
A microdevice for the measurement of the respiratory activity of cells was fabricated using a microfabricated Clark-type oxygen electrode. The oxygen electrode was completed in a dry state and was activated by introducing water necessary for the reduction of oxygen in the form of water vapor through an oxygen-permeable membrane, which significantly facilitated handling of the device even by nonspecialists. The use of a thin paper layer stabilized the current response and enabled stable continuous operation of the oxygen electrode without current disturbance caused by the evaporation of water. The microdevice was tested in some model experiments including the measurement of the respiratory activity of Escherichia coli (E. coli), evaluation of the efficacy of antibiotics, and measurement of the antibacterial activity of neutrophils, all of which demonstrated that the consumption of dissolved oxygen by cells can be monitored clearly by following an easy procedure for the preparation of the measurements.
Subject(s)
Escherichia coli , Oxygen , Electrodes , Neutrophils , Oxygen ConsumptionABSTRACT
While molecular oxygen is essential for aerobic organisms, its utilization is inseparably connected with generation of oxidative insults. To cope with the detrimental aspects, cells evolved antioxidative defense systems, and insufficient management of the oxidative insults underlies the pathogenesis of a wide range of diseases. A battery of genes for this antioxidative defense are regulated by the transcription factors nuclear factor-erythroid 2-like 1 and 2 (NRF1 and NRF2). While the regulatory steps for the activation of NRFs have been investigated with particular emphasis on nuclear translocation and proteosomal degradation, unknown redundancy may exist considering the indispensable nature of these defense systems. Here we unraveled that C-terminal binding protein 2 (CtBP2), a transcriptional cofactor with redox-sensing capability, is an obligate partner of NRFs. CtBP2 forms transcriptional complexes with NRF1 and NRF2 that is required to promote the expression of antioxidant genes in response to oxidative insults. Our findings illustrate a basis for understanding the transcriptional regulation of antioxidative defense systems that may be exploited therapeutically.
Subject(s)
Alcohol Oxidoreductases/metabolism , Co-Repressor Proteins/metabolism , NF-E2-Related Factor 1/metabolism , NF-E2-Related Factor 2/metabolism , Amino Acid Sequence , Antioxidants/metabolism , Gene Expression Regulation , Humans , NF-E2-Related Factor 1/chemistry , NF-E2-Related Factor 1/genetics , NF-E2-Related Factor 2/chemistry , NF-E2-Related Factor 2/genetics , Oxidative Stress , Protein Binding , Transcription, GeneticABSTRACT
BACKGROUND AND AIMS: Dysfunctional hepatic lipid metabolism is a cause of nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disorder worldwide, and is closely associated with insulin resistance and type 2 diabetes. ELOVL fatty acid elongase 6 (Elovl6) is responsible for converting C16 saturated and monounsaturated fatty acids (FAs) into C18 species. We have previously shown that Elovl6 contributes to obesity-induced insulin resistance by modifying hepatic C16/C18-related FA composition. APPROACH AND RESULTS: To define the precise molecular mechanism by which hepatic Elovl6 affects energy homeostasis and metabolic disease, we generated liver-specific Elovl6 knockout (LKO) mice. Unexpectedly, LKO mice were not protected from high-fat diet-induced insulin resistance. Instead, LKO mice exhibited higher insulin sensitivity than controls when consuming a high-sucrose diet (HSD), which induces lipogenesis. Hepatic patatin-like phospholipase domain-containing protein 3 (Pnpla3) expression was down-regulated in LKO mice, and adenoviral Pnpla3 restoration reversed the enhancement in insulin sensitivity in HSD-fed LKO mice. Lipidomic analyses showed that the hepatic ceramide(d18:1/18:0) content was lower in LKO mice, which may explain the effect on insulin sensitivity. Ceramide(d18:1/18:0) enhances protein phosphatase 2A (PP2A) activity by interfering with the binding of PP2A to inhibitor 2 of PP2A, leading to Akt dephosphorylation. Its production involves the formation of an Elovl6-ceramide synthase 4 (CerS4) complex in the endoplasmic reticulum and a Pnpla3-CerS4 complex on lipid droplets. Consistent with this, liver-specific Elovl6 deletion in ob/ob mice reduced both hepatic ceramide(d18:1/18:0) and PP2A activity and ameliorated insulin resistance. CONCLUSIONS: Our study demonstrates the key role of hepatic Elovl6 in the regulation of the acyl-chain composition of ceramide and that C18:0-ceramide is a potent regulator of hepatic insulin signaling linked to Pnpla3-mediated NAFLD.
Subject(s)
Ceramides/metabolism , Fatty Acid Elongases/physiology , Insulin Resistance/genetics , Liver/enzymology , Animals , Ceramides/chemistry , Dietary Sucrose/administration & dosage , Down-Regulation , Fatty Acid Elongases/genetics , Mice , Mice, Knockout , Non-alcoholic Fatty Liver Disease/genetics , Non-alcoholic Fatty Liver Disease/metabolism , Phospholipases A2, Calcium-Independent/metabolism , Protein Phosphatase 2/metabolism , Sphingosine N-Acyltransferase/metabolismABSTRACT
In a clinical trial involving Japanese patients with osteoporosis, post hoc analyses were performed to evaluate the incidence of acute phase reactions (APRs) after infusion of zoledronic acid (ZOL). The results highlighted differences in baseline factors between patients with vs without APRs. Changes in efficacy indicators such as bone turnover markers (BTMs) also showed significant differences. We, therefore, investigated the factors involved in the development of APRs in Japanese patients treated with a once-yearly intravenous infusion of ZOL 5 mg for 2 years by assessing the relation between APRs and efficacy. APRs reported in patients with primary osteoporosis from the ZONE study were analyzed post hoc. Baseline factors were compared in patients with vs without APRs, and changes in BTMs and bone mineral density (BMD) were also investigated. In the ZOL group, 51.2% (169/330) of patients developed APRs after the first infusion and 12.3% (33/268) after the second infusion. Comparison of baseline factors showed that patients without APRs in the ZOL group had a significantly higher neutrophil/lymphocyte ratio, lower serum levels of procollagen type I N-terminal propeptide, older age, and higher likelihood of prior bisphosphonate use vs patients with APRs. Patients with APRs showed significantly higher increases in total hip BMD at 6 and 12 months and larger reductions in BTMs vs patients without APRs. Patient profiles differed significantly between patients with vs without APRs, with APRs after the first infusion of ZOL being related to increases in total hip BMD and suppression of BTMs.This study is registered with ClinicalTrials.gov (identifier: NCT01522521; January 31, 2012).